CN114144439B - Method for preparing catalyst by using hydration reagent - Google Patents

Abstract

A method comprising a) contacting a solvent, a carboxylic acid and a peroxy-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1 ; b) contacting the titanium-containing compound with the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is from about 1:1 to about 1:4 , and the equivalent molar ratio of the titanium-containing compound to the peroxy-containing compound in the dissolved titanium mixture is about 1:1 to about 1:20; and c) making chromium containing about 0.1wt% to about 20wt% water - Contacting the silica support and the dissolved titanium mixture to form an addition product, and by heating to and maintaining the temperature in the range of about 50°C to about 150°C. The temperature ranges from about 30 minutes to about 6 hours to dry the addition product to form the procatalyst.

Description

Method for preparing catalyst using hydration reagent

Technical Field

The present disclosure relates to catalyst compositions. More specifically, the present disclosure relates to methods of preparing olefin polymerization catalyst compositions and polymers prepared from the olefin polymerization catalyst compositions.

Background Art

An economically important class of olefin polymerization catalysts includes chromium-silica-titanium (Cr/Si-Ti) catalysts prepared from silica-based catalyst supports. Rigorous drying of the water-sensitive catalyst components used to produce the Cr/Si-Ti catalysts increases production time and cost. The development of aqueous solutions suitable for depositing titanium onto silica-based catalyst supports will reduce the production cost of olefin polymerization catalysts. Therefore, there is a continuing need to develop new methods for producing olefin polymerization catalysts.

Summary of the invention

Disclosed herein is a procatalyst composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt % to about 95 wt % based on the total weight of the silica support, b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt % to about 5 wt % based on the amount of silica, c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.1 wt % to about 20 wt % based on the amount of silica, d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10, and e) a nitrogen-containing compound having a molecular formula containing at least one nitrogen atom, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

Also disclosed herein is a procatalyst composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support, b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica, and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein i) the amount of titanium is in the range of about 0.1 wt% to about 20 wt% based on the amount of silica, ii) the equivalent molar ratio of titanium to carboxylate is in the range of about 1:1 to about 1:10, and iii) the equivalent molar ratio of titanium to protonated nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

Also disclosed herein is a procatalyst composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt % to about 95 wt % based on the total weight of the silica support, b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt % to about 5 wt % based on the amount of silica, c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt % to about 0.1 wt % based on the amount of silica, d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10, and e) a nitrogen-containing compound having a molecular formula containing at least one nitrogen atom, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

Also disclosed herein is a procatalyst composition prepared by a process comprising: a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1, b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4, c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a dissolved titanium mixture, wherein the titanium-containing compound and the carboxylic acid in the dissolved titanium mixture are in an equivalent molar ratio of about 1:1 to about 1:4, The equivalent molar ratio of the nitrogen-containing compound is from about 1:1 to about 1:4, and the pH of the solubilized titanium mixture is less than about 5.5, and d) a chromium-silica carrier containing from about 0.1 wt% to about 20 wt% water is contacted with the solubilized titanium mixture to form an addition product, and the addition product is dried by heating the addition product to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature of the addition product in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours to form the procatalyst.

Also disclosed herein is a method comprising: a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1, b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4, and c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a dissolved titanium mixture, wherein the titanium-containing compound and the nitrogen-containing compound in the dissolved titanium mixture are molten. The invention further comprises the steps of: d) contacting a chromium-silica carrier containing about 0.1 wt % to about 20 wt % water with the dissolved titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating the addition product to a temperature in the range of about 50° C. to about 150° C. and maintaining the addition product at the temperature in the range of about 50° C. to about 150° C. for a period of about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1, b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4, c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:4, and the pH of the dissolved titanium mixture is about 3.5. in the range of about 4.5, d) contacting a silica carrier comprising about 0.1 wt % to about 20 wt % water and the dissolved titanium mixture to form a titanated carrier, and drying the titanated carrier to form a dried titanated carrier by heating the titanated carrier to a temperature in the range of about 50°C to about 150°C and maintaining the temperature of the titanated carrier in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours, and e) contacting a chromium-containing compound and at least one material selected from the group consisting of the silica carrier, the titanated carrier and the dried titanated carrier to form a precatalyst.

Also disclosed herein is a method comprising a) contacting a titanium-containing compound and a nitrogen-containing compound to form a basic mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the basic mixture is about 1:1 to about 1:4, b) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is about 1:1 to about 100:1, c) contacting the basic mixture and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is about 1:1 to about 100:1, ratio is from about 1:1 to about 1:4, and the pH of the solubilized titanium mixture is in the range of from about 3.5 to about 4.5, and d) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating the addition product to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature of the addition product in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a titanium-containing compound and a nitrogen-containing compound to form an alkaline mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the alkaline mixture is about 1:1 to about 1:4, b) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is about 1:1 to about 100:1, c) contacting the alkaline mixture and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is about 1:1 to about 1:4, and the pH of the dissolved titanium mixture is about 3.5 to 4. 4.5, d) contacting a silica carrier comprising about 0.1 wt % to about 20 wt % water and the dissolved titanium mixture to form a titanated carrier, and drying the titanated carrier to form a dried titanated carrier by heating the titanated carrier to a temperature in the range of about 50°C to about 150°C and maintaining the temperature of the titanated carrier in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours, and e) contacting a chromium-containing compound and at least one material selected from the group consisting of the silica carrier, the titanated carrier and the dried titanated carrier to form a precatalyst.

Also disclosed herein is a method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a solvent, at least two carboxylic acids, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1, and wherein the at least two carboxylic acids comprise at least one simple carboxylic acid and at least one complex carboxylic acid; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a solvent, at least two carboxylic acids, and a nitrogen-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4; and c) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a solvent, at least two carboxylic acids, a nitrogen-containing compound, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising: a) contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is from about 1:1 to about 1:4, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the dissolved titanium mixture is from about 1:1 to about 1:4; :5; and wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water with the dissolved titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is from about 1:1 to about 1:4, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the dissolved titanium mixture is from about 1: to about 1:5; and wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:4. The equivalent molar ratio of the compounds is from about 1:1 to about 1:20; c) contacting the solubilized titanium mixture with a chromium-containing compound to form a chromium-titanium mixture; d) contacting the chromium-titanium mixture with a silica carrier containing silica to form an addition product, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica carrier; and e) drying the addition product to form a procatalyst by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours.

Also disclosed herein is a method comprising a) preparing an acidic mixture comprising a solvent and at least two components selected from the group consisting of one or more carboxylic acids, one or more acidic phenols, one or more peroxyl compounds, and one or more nitrogen-containing compounds, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting the acidic mixture with a chromium-containing compound, a titanium-containing compound, and a silica support to form an addition product, wherein: (i) the equivalent molar amount of the titanium-containing compound to the carboxylic acid when present in the acidic mixture is The invention relates to a method of preparing a precatalyst comprising: (i) an aqueous solution of titanium-containing compound and an aqueous solution of titanium-containing compound having an equivalent molar ratio of about 1:1 to about 1:4, (ii) an equivalent molar ratio of the titanium-containing compound to the acidic phenol when present in the acidic mixture is about 1: to about 1:5, and (iii) an equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound when present in the acidic mixture is about 1:1 to about 1:20; and c) drying the addition product by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours to form a procatalyst.

Also disclosed herein is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is in the range of about 1:1 to about 1:20.

Also disclosed herein is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a carboxylate, and a peroxide-containing compound, and wherein the titanium organic salt comprises i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to peroxide-containing compound in the range of about 1:0.5 to about 1:20.

Also disclosed herein is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt% to about 0.1 wt% based on the amount of silica; d) at least two carboxylic acids, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is in the range of about 1:1 to about 1:10.

Also disclosed herein is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein the titanium organic salt comprises: i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to protonated nitrogen-containing compound in the range of about 1:0.5 to about 1:10; and d) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is about 1:1 to about 1:20.

Also disclosed herein is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein the titanium organic salt comprises i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to protonated nitrogen-containing compound in the range of about 1:0.5 to about 1:10; and d) an acidic phenol, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the acidic titanium mixture is about 1:1 to about 1:5.

Also disclosed herein is a composition comprising a) at least two components selected from the group consisting of one or more carboxylic acids, one or more acidic phenols, one or more peroxide-containing compounds, and one or more nitrogen-containing compounds; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt % to about 5 wt % based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt % to about 0.1 wt % based on the amount of silica; and (i) wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid, when present, is in the range of about 1:1 to about 1:10; (ii) wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound, when present, is in the range of about 1:1 to about 1:10; (iii) wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol, when present, in the acidic titanium mixture is about 1:1 to about 1:5; and (iv) wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound, when present, is in the range of about 1:0.5 to about 1:5.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of this specification and are included to further illustrate certain aspects of the present disclosure. The subject matter of the present disclosure may be more fully understood by referring to the drawings in conjunction with the detailed description of the specific aspects presented herein.

The accompanying figure illustrates the relationship between the zeta potential of silica and titania and pH.

Although the subject matter disclosed herein is susceptible to various modifications and alternative forms, only a few specific aspects have been shown by way of example in the drawings and described in detail below. The drawings and detailed description of these specific aspects are not intended to limit the breadth or scope of the disclosed subject matter or the appended claims in any way. Rather, the drawings and detailed written description are provided to illustrate the disclosure to those skilled in the art and to enable such persons to make and use the concepts disclosed herein.

DETAILED DESCRIPTION

The present disclosure encompasses olefin polymerization catalysts and procatalysts thereof, methods for preparing olefin polymerization catalysts and procatalysts thereof, and methods utilizing olefin polymerization catalysts. On the one hand, a method disclosed herein includes contacting a silica carrier or a chromium-silica carrier (i.e., a carrier) with titanium to produce a Cr/Si-Ti catalyst. The method disclosed herein contemplates the use of a dissolved titanium mixture (STM) to facilitate the association of titanium with a carrier in the presence of water. In this article, a method for preparing an olefin polymerization catalyst includes contacting a chromium-silica carrier with STM under conditions suitable for forming a catalyst composition. An alternative method for preparing an olefin polymerization catalyst includes contacting a silica carrier with STM and chromium under conditions suitable for forming a catalyst composition. Although these aspects may be disclosed under specific headings, the headings do not limit the disclosure found therein. In addition, various aspects and embodiments disclosed herein may be combined in any manner.

Aspects of the present disclosure relate to catalyst compositions and procatalyst compositions. In one aspect, the catalyst composition comprises an olefin polymerization catalyst. In another aspect, the olefin polymerization catalyst comprises a treated procatalyst composition. In another aspect, the treated procatalyst composition comprises a procatalyst that has been subjected to an activation treatment (e.g., calcined) as disclosed herein.

Procatalyst compositions are disclosed herein. In one aspect, the procatalyst composition comprises a silica support, a chromium-containing compound, a titanium-containing compound, a carboxylic acid, and a nitrogen-containing compound. Alternatively, the procatalyst composition comprises a silica support, a chromium-containing compound, and a titanium organic salt. Alternatively, the procatalyst composition comprises a silica support, a chromium-containing compound, a titanium-containing compound, a carboxylic acid, a nitrogen-containing compound, and a peroxide-containing compound. Alternatively, the procatalyst composition comprises a silica support, a chromium-containing compound, a titanium-containing compound, a carboxylic acid, and a peroxide-containing compound. Alternatively, the procatalyst composition comprises a silica support, a chromium-containing compound, a titanium-containing compound, an acidic phenol, and a peroxide-containing compound. In some aspects, the procatalyst composition comprises a silica support, a chromium-containing compound, a titanium-containing compound, one or more carboxylic acids, one or more nitrogen-containing compounds, one or more acidic phenols, one or more peroxide-containing compounds, or any combination thereof.

In one aspect, the olefin polymerization catalyst and the procatalyst thereof of the present disclosure comprise a silica support. The silica support may be any silica support suitable for preparing the olefin polymerization catalyst and the procatalyst thereof as disclosed herein. In another aspect, the preparation of the olefin polymerization catalyst and the procatalyst thereof excludes heat treatment of the silica support prior to contact with any other catalyst component. Therefore, the silica support suitable for use in the present disclosure may be referred to as a hydrated silica support. Without wishing to be limited by theory, the hydrated silica support comprises a silica support wherein water emission occurs when the silica support is heated under vacuum conditions in the range of about 180° C. to about 200° C. for a period in the range of about 8 hours to about 20 hours. In another aspect, the silica support thus treated may emit about 0.1 wt % to about 20 wt % water, based on the total weight of the silica support; alternatively, about 1 wt. % to about 20 wt % water; alternatively, about 1 wt % to about 10 wt % water; or alternatively, about 0.1 wt % to about 10 wt % water.

Silica supports suitable for use in the present disclosure may have a surface area and pore volume effective to provide for the production of an active olefin polymerization catalyst. In one aspect of the present disclosure, the silica support has a surface area in the range of about 100 m ² /g to about 1000 m ² /g; alternatively, about 250 m ² /g to about 1000 ^m 2 /g; alternatively, about 250 m ² /g to about 700 m ² /g; alternatively, about 250 m ² /g to about 600 m ² /g; or alternatively, greater than about 250 m ² /g. The silica support may also be characterized as having a pore volume greater than about 0.9 cm ³ /g; alternatively, greater than about 1.0 cm ³ /g; or alternatively, greater than about 1.5 cm ³ /g. In one aspect of the present disclosure, the silica support is characterized as having a pore volume in the range of about 1.0 cm ³ /g to about 2.5 cm ³ /g. The silica support may also be characterized as having an average particle size in the range of about 10 microns to about 500 microns; alternatively, about 25 microns to about 300 microns; or alternatively, about 40 microns to about 150 microns. Typically, the average pore size of the silica support may be in the range of about 10 Angstroms to about 1000 Angstroms. In one aspect of the present disclosure, the average pore size of the silica support is in the range of about 50 Angstroms to about 500 Angstroms; alternatively, about 75 Angstroms to about 350 Angstroms.

Based on the total weight of the silica support, the silica support suitable for use in the present disclosure may contain greater than about 50 wt% silica; alternatively, greater than about 80 wt% silica; or alternatively, greater than about 95 wt% silica. In one aspect, the silica support contains silica in an amount ranging from about 70 wt% to about 95 wt%, based on the total weight of the silica support. The silica support may be prepared using any suitable method, for example, the silica support may be prepared by hydrolyzing tetrachlorosilane (SiCl ₄ ) with water or by contacting sodium silicate with a mineral acid. In a particular aspect, the silica support may be a hydrogel or a preformed silica support, wherein the preformed silica support is optionally dried before contacting with any other catalyst component. The silica support may include additional components that do not adversely affect the catalyst, such as zirconium oxide, aluminum oxide, thorium oxide, magnesium oxide, fluoride, sulfate, phosphate, or a combination thereof. In a particular aspect, the silica support of the present disclosure comprises aluminum oxide. Non-limiting examples of silica supports suitable for use in the present disclosure include ES70, a silica support material commercially available from PQ Corporation having a surface area of 300 ^m2 /g and a pore volume of 1.6 ^cm3 /g; and V398400, a silica support material commercially available from Evonik.

In a specific aspect of the present disclosure, a silica support suitable for use in the present disclosure comprises chromium. A silica support comprising chromium may be referred to as a chromated silica support or a chromium-silica support. In another aspect, a chromium-silica support comprises the features disclosed herein for a silica support while additionally containing chromium. A non-limiting example of a chromated silica support is HW30A, which is a chromium-silica support material commercially available from W.R. Grace and Company.

The silica support may be present in the olefin polymerization catalyst and its procatalyst in an amount ranging from about 50 wt% to about 99 wt%; or alternatively, from about 80 wt% to about 99 wt%. In this document, the silica support percentage refers to the weight percentage (wt%) of the silica support associated with the olefin polymerization catalyst based on the total weight of the olefin polymerization catalyst after all processing steps are completed (i.e., after activation by calcination). Alternatively, the silica support percentage refers to the weight percentage (wt%) of the silica support associated with the procatalyst based on the total weight of the procatalyst after all relevant processing steps excluding activation by calcination are completed.

On the other hand, the olefin polymerization catalyst and its procatalyst of the present disclosure contain chromium. The source of chromium can be any chromium-containing compound that can provide sufficient chromium to the olefin polymerization catalyst and its procatalyst. On the one hand, the chromium-containing compound can be a water-soluble chromium compound or a hydrocarbon-soluble chromium compound. Examples of water-soluble chromium compounds include chromium trioxide, chromium acetate, chromium nitrate, or a combination thereof. Examples of hydrocarbon-soluble chromium compounds include tert-butyl chromate, dicyclopentadienyl chromium (II), chromium (III) acetylacetonate, or a combination thereof. In one aspect of the present disclosure, the chromium-containing compound can be a chromium (II) compound, a chromium (III) compound, or a combination thereof. Suitable chromium (III) compounds include, but are not limited to, chromium (III) carboxylates, chromium (III) naphthenates, chromium (III) halides, chromium (III) sulfates, chromium (III) nitrates, chromium (III) diketonates, or a combination thereof. Specific chromium (III) compounds include, but are not limited to, chromium (III) sulfate, chromium (III) chloride, chromium (III) nitrate, chromium (III) bromide, chromium (III) acetylacetonate, and chromium (III) acetate. Suitable chromium (II) compounds include, but are not limited to, chromium (II) chloride, chromium (II) bromide, chromium (II) iodide, chromium (II) sulfate, chromium (II) acetate, or combinations thereof.

Based on the total weight of the olefin polymerization catalyst, the amount of chromium present in the olefin polymerization catalyst may be in the range of about 0.01 wt% to about 10 wt%; alternatively, about 0.5 wt% to about 5 wt%; alternatively, about 1 wt% to about 4 wt%; or alternatively, about 2 wt% to about 4 wt% chromium. On the other hand, based on the total weight of the olefin polymerization catalyst, the amount of chromium present in the olefin polymerization catalyst may be in the range of about 1 wt% to about 5 wt% chromium. In this article, the chromium percentage refers to the weight percentage (wt%) of chromium associated with the olefin polymerization catalyst based on the total weight of the olefin polymerization catalyst after all processing steps are completed (i.e., after activation by calcination). On the other hand, based on the total weight of silica in the procatalyst, the amount of chromium present in the procatalyst may be in the range of about 0.01 wt% to about 10 wt%; alternatively, about 0.1 wt% to about 5 wt%; alternatively, about 0.2 wt% to about 2 wt%; or alternatively, about 0.5 wt% to about 1.5 wt% chromium. As used herein, chromium percentage refers to the weight percent (wt%) of chromium associated with the procatalyst, based on the total weight of silica in the procatalyst, after all processing steps excluding activation by calcination have been completed.

On the other hand, the olefin polymerization catalyst and its procatalyst of the present disclosure contain titanium. The source of titanium can be any titanium-containing compound capable of providing sufficient titanium to the olefin polymerization catalyst and its procatalyst. On the other hand, the titanium-containing compound includes a tetravalent titanium (Ti(IV)) compound or a trivalent titanium (Ti(III)) compound. The Ti(IV) compound can be any compound containing Ti(IV); alternatively, the Ti(IV) compound can be any compound capable of releasing a Ti(IV) species after being dissolved in a solution. The Ti(III) compound can be any compound containing Ti(III); alternatively, the Ti(III) compound can be any compound capable of releasing a Ti(III) species after being dissolved in a solution.

In one aspect, titanium-containing compounds suitable for use in the present disclosure include Ti(IV) compounds having at least one alkoxy group; or alternatively, at least two alkoxy groups. Ti(IV) compounds suitable for use in the present disclosure include, but are not limited to, Ti(IV) compounds having the general formula TiO(OR ^K ) ₂ , Ti(OR ^K ) ₂ (acac) ₂ , Ti(OR ^K ) ₂ (oxal), combinations thereof, wherein R ^K may be ethyl, isopropyl, n-propyl, isobutyl, n-butyl, or combinations thereof; “acac” is acetylacetonate; and “oxal” is oxalate. Alternatively, the titanium-containing compound includes titanium(IV) alkoxide. In one aspect, the titanium(IV) alkoxide may be titanium(IV) ethoxide, titanium(IV) isopropoxide, titanium(IV) n-propoxide, titanium(IV) n-butoxide, titanium(IV) 2-ethylhexoxide, or combinations thereof. In a specific aspect, the titanium-containing compound may be titanium(IV) isopropoxide.

In another aspect, titanium-containing compounds suitable for use in the present disclosure may include hydrated titanium dioxide, titanium hydroxide, titanic acid, titanyl sulfate, titanium acetylacetonate, titanyl acetylacetonate, or combinations thereof.

In another aspect, titanium-containing compounds suitable for use in the present disclosure may include titanium (IV) halides, non-limiting examples of which include titanium tetrachloride, titanium tetrabromide, titanium (IV) dichloride, and titanium (IV) dibromide. In another aspect, the titanium (IV) halide may include a titanium alkoxy halide having the general formula Ti(OR ^K ) _n Q _4-n ; wherein R ^K may be ethyl, isopropyl, n-propyl, isobutyl, n-butyl, or a combination thereof; wherein Q may be fluorine, chlorine, bromine, iodine, or a combination thereof; and wherein n may be an integer from 1 to 4.

Based on the total weight of the olefin polymerization catalyst of the present disclosure, the amount of titanium present in the olefin polymerization catalyst may be in the range of about 0.01 wt% to about 10 wt%; alternatively, about 0.5 wt% to about 5 wt%; alternatively, about 1 wt% to about 4 wt%; or alternatively, about 2 wt% to about 4 wt% titanium. On the other hand, based on the total weight of the olefin polymerization catalyst, the amount of titanium present in the olefin polymerization catalyst may be in the range of about 1 wt% to about 5 wt% titanium. In this article, the titanium percentage refers to the weight percentage (wt%) of titanium associated with the olefin polymerization catalyst based on the total weight of the olefin polymerization catalyst after all processing steps are completed (i.e., after activation by calcination). On the other hand, based on the total weight of silica in the precatalyst of the present disclosure, the amount of titanium present in the precatalyst may be in the range of about 0.01 wt% to about 25 wt%; alternatively, about 0.1 wt% to about 20 wt%; alternatively, about 0.5 wt% to about 10 wt%; alternatively, about 1 wt% to about 6 wt%; or alternatively, about 2 wt% to about 4 wt% titanium. As used herein, titanium percentage refers to the weight percent (wt%) of titanium associated with the procatalyst, based on the total weight of silica in the procatalyst, after all processing steps have been completed excluding activation by calcination.

In one aspect, the olefin polymerization catalyst and its procatalyst of the present disclosure include one or more carboxylic acids. The carboxylic acid may be a monocarboxylic acid, a dicarboxylic acid, a tricarboxylic acid, an α-hydroxycarboxylic acid, a β-hydroxycarboxylic acid, an α-ketocarboxylic acid, or a combination thereof. In one aspect, the carboxylic acid may be a C ₁ to C ₁₅ monocarboxylic acid or a C ₁ to C ₅ monocarboxylic acid; alternatively, a C ₃ to C ₁₅ dicarboxylic acid or a C ₃ to C ₅ dicarboxylic acid; alternatively, a C ₁ to C ₁₅ tricarboxylic acid or a C ₁ to C ₅ tricarboxylic acid; alternatively, a C ₁ to C ₁₅ α-hydroxycarboxylic acid or a C ₁ to C ₅ α-hydroxycarboxylic acid; alternatively, a C ₁ to C ₁₅ β-hydroxycarboxylic acid or a C ₁ to C ₅ β-hydroxycarboxylic acid; or alternatively, a C ₁ to C ₁₅ α-ketocarboxylic acid or a C ₁ to C ₅ α-ketocarboxylic acid.

In a particular aspect, the one or more carboxylic acids can be acetic acid, citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, gluconic acid, mandelic acid, 2,4-hydroxybenzoic acid, 2,6-pyridinedicarboxylic acid, nitrotriacetic acid, α-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, salicylic acid, catechol, 2-(hydroxymethyl)butyric acid, or a combination thereof. In another aspect, the carboxylic acid can be oxalic acid.

On the other hand, the olefin polymerization catalyst and the procatalyst thereof of the present disclosure comprise at least two carboxylic acids. In such aspects, the at least two carboxylic acids may comprise at least one simple carboxylic acid and at least one complex carboxylic acid, wherein the complex carboxylic acid comprises at least one ring structure. For example, the at least two carboxylic acids may be oxalic acid and phenylmalonic acid.

In one aspect, the olefin polymerization catalyst of the present disclosure and its procatalyst comprise acidic phenol. Acidic phenol can be any acidic phenol that can provide the olefin polymerization catalyst and procatalyst of the type disclosed herein. In one aspect, acidic phenol comprises catechol, salicyl alcohol, salicylic acid, phthalic acid or their derivatives. In some aspects, the olefin polymerization catalyst of the present disclosure and its procatalyst comprise carboxylic acid and acidic phenol, both of which belong to the type disclosed herein.

The procatalyst of the present disclosure comprises an equivalent molar ratio of titanium to carboxylic acid in the range of about 1:1 to about 1:10; alternatively, about 1:1 to about 1:5; or alternatively, about 1:1.5 to about 1:4. In one aspect, the equivalent molar ratio of titanium to carboxylic acid is in the range of about 1:1 to about 1:2. Alternatively, the procatalyst of the present disclosure comprises an equivalent molar ratio of titanium to acidic phenol in the range of about 1:1 to about 1:10; alternatively, about 1:1 to about 1:5; or alternatively, about 1:1.5 to about 1:4. In one aspect, the equivalent molar ratio of titanium to acidic phenol is in the range of about 1:1 to about 1:2.

On the one hand, the olefin polymerization catalyst and its procatalyst of the present disclosure comprise a nitrogen-containing compound. The nitrogen-containing compound can be any nitrogen-containing compound suitable for providing effective titanation of the olefin polymerization catalyst and its procatalyst. On the other hand, the nitrogen-containing compound can have Structure 1, Structure 2, Structure 3, Structure 4, Structure 5, Structure 6, or a combination thereof.

NR ¹ R ² R ³ N(R ⁴ ) _x H _(4-x) OH NR ⁵ R ⁶ (CR ⁷ R ⁸ ) _y OH

Structure 1 Structure 2 Structure 3

NR ⁹ R ¹⁰ OH Z＝C(N(R ¹¹ ) ₂ ) ₂ N(R ¹² OH) ₃

Structure 4 Structure 5 Structure 6

R ¹ , R ² , R ³ , R ⁴ , R ^{5 ,} R ⁶ , R ⁷ , R ⁸ , R 9, R ¹⁰ , R ¹¹ and R ¹² within the nitrogen-containing compounds utilized as described herein are independent elements of the nitrogen-containing compound structures in which they are present and are independently described herein. The independent descriptions of R ¹ , R ² , R ³ , R ⁴ , R 5, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and/or R ¹² provided herein can be utilized without limitation and in any combination to further describe any nitrogen-containing compound structure comprising R ¹ , R ² , R ³ , R ⁴ , R ^{5 ,} R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and/or R ¹² .

Typically, R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ of the corresponding nitrogen-containing compound having R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ can each independently be hydrogen, an organic group, a hydrocarbon group or an aryl group. In one aspect, R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ can each independently be a C ₁ to C ₃₀ organic group; alternatively, a C ₁ to C ₁₂ organic group; or alternatively, a C ₁ to C ₆ organic group. In one aspect, R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ can each independently be a C ₁ to C ₃₀ hydrocarbon group; alternatively, a C ₁ to C ₁₂ hydrocarbon group; or alternatively, a C ₁ to C ₆ hydrocarbon group. In other aspects, R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ can each independently be a C ₆ to C ₃₀ aryl group; or alternatively, a C ₆ to C ₁₂ aryl group. In another aspect, the organic groups, hydrocarbon groups or aryl groups that can be used as R ¹ , R ² , R ³ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ in the nitrogen-containing compounds of the present disclosure can be substituted or unsubstituted. Those skilled in the art will appreciate that the terms "alkyl,""organicgroup,""hydrocarbyl," and "aryl" are used herein according to the definitions from the IUPAC Compendium of Chemical Terminology, 2nd Edition (1997).

R ⁴ of the corresponding nitrogen-containing compound with R ⁴ may be an organic group, a hydrocarbon group, or an aryl group. In one aspect, R ⁴ may be a C ₁ to C ₃₀ organic group; alternatively, a C ₁ to C ₁₂ organic group; or alternatively, a C ₁ to C ₆ organic group. In one aspect, R ⁴ may be a C ₁ to C ₃₀ hydrocarbon group; alternatively, a C ₁ to C ₁₂ hydrocarbon group; or alternatively, a C ₁ to C ₆ hydrocarbon group. In other aspects, R ⁴ may be a C ₆ to C ₃₀ aryl group; or alternatively, a C ₆ to C ₁₂ aryl group. In another aspect, the organic group, hydrocarbon group, or aryl group that can be used as R ⁴ in the nitrogen-containing compound of the present disclosure may be substituted or unsubstituted.

In a particular aspect, any substituted organic group, substituted hydrocarbon group or substituted aryl group that can be used as R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and/or R ¹¹ can contain one or more non-hydrogen substituents. Suitable non-hydrogen substituents for use herein can be halogen, C ₁ to C ₁₂ hydrocarbon group, C ₁ to C ₁₂ alkoxy group or a combination thereof. In one aspect, the halogen used as the non-hydrogen substituent can be fluorine, chlorine, bromine or iodine. Non-limiting examples of C ₁ to C ₁₂ alkoxy groups suitable for use herein include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, phenoxy, tolyloxy, xyloxy, trimethylphenoxy and benzoyloxy.

R ⁷ and/or R ⁸ of the corresponding nitrogen-containing compound having R ⁷ and/or R ⁸ may each independently be hydrogen or methyl.

R ¹² of the corresponding nitrogen-containing compound having R ¹² may be a branched alkyl group or a straight-chain alkyl group. In one aspect, R ¹² may be a C ₁ to C ₃₀ branched alkyl group; alternatively, a C ₁ to C ₁₂ branched alkyl group; or alternatively, a C ₁ to C ₆ branched alkyl group. In another aspect, R ¹² may be a C ₁ to C ₃₀ straight-chain alkyl group; alternatively, a C ₁ to C ₁₂ straight-chain alkyl group; or alternatively, a C ₁ to C ₆ straight-chain alkyl group.

In another aspect, nitrogen-containing compounds of the present disclosure having structure 2 can have x, wherein x is an integer from 1 to 4. In one aspect, nitrogen-containing compounds having structure 3 can have y, wherein y is an integer from 1 to 12. In another aspect, nitrogen-containing compounds having structure 5 can have Z, wherein Z is oxygen or sulfur.

In one aspect, the nitrogen-containing compound suitable for use in the present disclosure may be an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, an aniline, a hydrazide, a hydroxylamine, an imine, a urea, or a combination thereof. In another aspect, the alkanolamine, an amide, an amine, an ammonium hydroxide, a hydrazide, a hydroxylamine, an imine, a urea, or a combination thereof used as the nitrogen-containing compound may contain one or more substituent groups. In one aspect, any substituent group contained in any nitrogen-containing compound of the present disclosure may be a halogen, a C ₁ to C ₁₂ organic group, a C ₁ to C ₁₂ hydrocarbon group, a C ₁ to C ₁₂ alkoxy group, or a combination thereof. The halogen used as a substituent group of any aspect disclosed herein may be fluorine, chlorine, bromine, or iodine. Non-limiting examples of C ₁ to C ₁₂ alkoxy groups suitable for use herein include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, phenoxy, tolyloxy, xylyloxy, trimethylphenoxy, and benzoyloxy.

In another aspect, non-limiting examples of specific nitrogen-containing compounds suitable for use in the present disclosure include acetamide, acrylamide, allylamine, ammonia, ammonium hydroxide, butylamine, tert-butylamine, N,N'-dibutylurea, creatine, creatinine, diethanolamine, diethylhydroxylamine, diisopropanolamine, dimethylaminoethanol, dimethylcarbamate, dimethylformamide, dimethylglycine, dimethylisopropanolamine, N,N'-dimethylurea, ethanolamine, ethylamine, ethylene glycolamine, hexylamine, hydroxylamine, imidazole, isopropanolamine, methacrylamide, methylamine, N-methylaniline, N-methyl-2-propanolamine, methyldiethanolamine, methylformamide, propylamine, 2-propanolamine, pyrazole, pyrrolidine, pyrrolidone, succinimide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanolamine, triisopropanolamine, trimethylamine, urea, 1,8-diazabicyclo[5.4.0]undec-7-ene, or combinations thereof.

The procatalyst of the present disclosure comprises an equivalent molar ratio of titanium to nitrogen-containing compound in the range of about 2:1 to about 1:10; alternatively, about 1:1 to about 1:5; or alternatively, about 1:1.5 to about 1:4. In one aspect, the equivalent molar ratio of titanium to nitrogen-containing compound is in the range of about 1:1 to about 1:2.

In a specific aspect, the procatalyst composition of the present disclosure comprises a titanium organic salt. In one aspect, the procatalyst composition comprising a titanium organic salt further comprises a silica support and a chromium-containing compound, both of which are of the type previously disclosed herein. In another aspect, the titanium organic salt suitable for use herein comprises titanium, a protonated nitrogen-containing compound, and a carboxylate.

In one aspect, the titanium organic salt comprises titanium. The source of titanium can be any titanium-containing compound capable of providing sufficient titanium to the procatalyst as disclosed herein. In another aspect, the source of titanium is a titanium-containing compound of the type previously disclosed herein.

In one aspect, the titanium organic salt comprises a protonated nitrogen-containing compound. The protonated nitrogen-containing compound can be any protonated nitrogen-containing compound capable of providing sufficient titanium to the procatalyst as disclosed herein. In another aspect, the protonated nitrogen-containing compound can include a protonated form of any nitrogen-containing compound of the type previously disclosed herein.

In one aspect, the protonated nitrogen-containing compound comprises a protonated alkanolamine, a protonated amide, a protonated amine, a protonated alkylamine, a protonated ammonium hydroxide, a protonated aniline, a protonated hydroxylamine, a protonated urea, or a combination thereof.

In another aspect, the protonated nitrogen-containing compound comprises protonated acetamide, protonated acrylamide, protonated allylamine, ammonium, protonated ammonium hydroxide, protonated butylamine, protonated tert-butylamine, protonated N,N'-dibutylurea, protonated creatine, protonated creatinine, protonated diethanolamine, protonated diethylhydroxylamine, protonated diisopropanolamine, protonated dimethylaminoethanol, protonated dimethylcarbamate, protonated dimethylformamide, protonated dimethylglycine, protonated dimethylisopropanolamine, protonated N,N'-dimethylurea, protonated ethanolamine, protonated ethylamine, protonated ethylene glycolamine, protonated hexylamine, Protonated hydroxylamine, protonated imidazole, protonated isopropanolamine, protonated methacrylamide, protonated methylamine, protonated N-methylaniline, protonated N-methyl-2-propanolamine, protonated methyldiethanolamine, protonated methylformamide, protonated propylamine, protonated 2-propanolamine, protonated pyrazole, protonated pyrrolidine, protonated pyrrolidone, protonated succinimide, protonated tetraethylammonium hydroxide, protonated tetramethylammonium hydroxide, protonated triethanolamine, protonated triisopropanolamine, protonated trimethylamine, protonated urea, protonated 1,8-diazabicyclo[5.4.0]undec-7-ene, or a combination thereof.

In another aspect, the titanium organic salt comprises a carboxylate. The carboxylate can be any carboxylate capable of providing a sufficient amount of titanium to the procatalyst as disclosed herein. In one aspect, the carboxylate can comprise an anionic form of any carboxylic acid of the type previously disclosed herein.

In another aspect, the carboxylate comprises a _C1 to _C15 monocarboxylate, a _C2 to _C15 dicarboxylate, a _C3 to _C15 tricarboxylate, a _C1 to _C15 α-hydroxycarboxylate, or a combination thereof.

In another aspect, the carboxylate comprises acetate, citrate, gluconate, glycolate, glyoxylate, lactate, malate, malonate, oxalate, phosphonoacetate, tartrate, or a combination thereof.

In another aspect, the amount of titanium present in the titanium organic salt of the present disclosure may be in the range of about 0.01 wt% to about 20 wt%; alternatively, about 0.5 wt% to about 10 wt%; or alternatively, about 1 wt% to about 6 wt% titanium, based on the total weight of the silica of the procatalyst as disclosed herein. In another aspect, the titanium organic salt comprises an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; alternatively, about 1:1 to about 1:5; or alternatively, about 1:1.5 to about 1:4. In some aspects, the equivalent molar ratio of titanium to carboxylate may be about 1:2. In another aspect, the titanium organic salt comprises an equivalent molar ratio of titanium to nitrogen-containing compound in the range of about 2:1 to about 1:10; alternatively, about 1:1 to about 1:5; or alternatively, about 1:1.5 to about 1:4. In another aspect, the equivalent molar ratio of titanium to nitrogen-containing compound may be about 1:2.

On the one hand, the olefin polymerization catalyst and its procatalyst of the present disclosure include peroxide-containing compounds. The peroxide-containing compound can be any peroxide-containing compound suitable for providing effective titanation of the olefin polymerization catalyst and its procatalyst. On the other hand, the peroxide-containing compound includes an organic peroxide, a diacyl peroxide, a peroxydicarbonate, a monoperoxycarbonate, a peroxyketal, a peroxyester, a dialkyl peroxide, a hydroperoxide, or any combination thereof. On the one hand, the peroxide-containing compound includes hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropylbenzene peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, phthalyl peroxide, or any combination thereof. On the one hand, the peroxide-containing compound includes hydrogen peroxide. On the one hand, the procatalyst of the present disclosure includes an equivalent molar ratio of titanium to the peroxide-containing compound in the range of about 1.0:0.5 to about 1:50, alternatively, about 1:2 to about 1:20, or alternatively, about 1:5 to about 1:10. In some aspects, the use of peroxide-containing compounds in olefin polymerization catalysts and procatalysts thereof results in increased solubility of the carboxylic acid-Ti component of the STM.

In one aspect of the present disclosure, a method for preparing an olefin polymerization catalyst includes utilizing a dissolved titanium mixture (STM). In a specific aspect, the STM of the present disclosure comprises carboxylic acid, a titanium-containing compound, a nitrogen-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, a titanium-containing compound, a nitrogen-containing compound, an optional peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, a titanium-containing compound, a nitrogen-containing compound, a peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, a titanium-containing compound, a nitrogen-containing compound, a peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, a titanium-containing compound, a peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises acidic phenols, a titanium-containing compound, a nitrogen-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises acidic phenols, a titanium-containing compound, a nitrogen-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises acidic phenols, a titanium-containing compound, a peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, an acidic phenol, a titanium-containing compound, a peroxide-containing compound and a solvent. On the other hand, the STM of the present disclosure comprises carboxylic acid, acidic phenol, nitrogen-containing compound, titanium-containing compound, peroxide-containing compound and solvent. On the one hand, STM comprises carboxylic acid of the type used as a component of the procatalyst as disclosed herein, alternatively, at least two carboxylic acids of the type used as a component of the procatalyst as disclosed herein. On the other hand, STM comprises titanium-containing compound of the type used as a component of the procatalyst as disclosed herein. On the other hand, STM comprises one or more nitrogen-containing compounds of the type used as a component of the procatalyst as disclosed herein. On the other hand, STM comprises one or more peroxide-containing compounds of the type used as a component of the procatalyst as disclosed herein. On the other hand, STM comprises one or more acidic phenols of the type used as a component of the procatalyst as disclosed herein.

On the other hand, the STM of the present disclosure comprises a solvent. The solvent may be an aqueous solvent, an alcohol, an organic solvent, a hydrocarbon, or a combination thereof. Non-limiting examples of aqueous solvents suitable for use in the present disclosure include deionized water, distilled water, filtered water, or a combination thereof. Non-limiting examples of alcohols suitable for use as solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, amyl alcohol, hexanol, cyclohexanol, heptanol, octanol, benzyl alcohol, phenol, or a combination thereof. On the other hand, organic solvents suitable for use in the present disclosure may be esters, ketones, or a combination thereof. Non-limiting examples of esters suitable for use as solvents include ethyl acetate, propyl acetate, butyl acetate, isobutyl isobutyrate, methyl lactate, ethyl lactate, or a combination thereof. Non-limiting examples of ketones suitable for use as solvents include acetone, ethyl methyl ketone, methyl isobutyl ketone, or a combination thereof. In a particular aspect, hydrocarbons suitable for use as solvents may be halogenated aliphatic hydrocarbons, aromatic hydrocarbons, halogenated aromatic hydrocarbons, or a combination thereof. Non-limiting examples of hydrocarbons suitable for use as solvents include methylene chloride, chloroform, carbon tetrachloride, ethylene dichloride, ethylene trichloride, benzene, toluene, ethylbenzene, xylenes, chlorobenzene, dichlorobenzene, or combinations thereof.

In a particular aspect, a solubilized titanium mixture (STM) as disclosed herein comprises an acidic mixture that can be prepared by contacting one or more carboxylic acids and a solvent, or alternatively, one or more acidic phenols and a solvent. In one aspect, the STM is prepared by sequentially adding a titanium-containing compound and a nitrogen-containing compound to an acidic mixture as disclosed herein. In an alternative aspect, the titanium-containing compound and the nitrogen-containing compound can be contacted to form an alkaline mixture, which is then contacted with the acidic mixture to form the STM as disclosed herein. In another aspect, the nitrogen-containing compound used to form the alkaline mixture can be a component of an aqueous solution.

On the other hand, the dissolved titanium mixture (STM) as disclosed herein comprises an acidic mixture. The acidic mixture can be prepared by contacting a carboxylic acid with a peroxide-containing compound and a solvent. Alternatively, the acidic mixture can be prepared by contacting at least two carboxylic acids with a peroxide-containing compound and a solvent. Alternatively, the acidic mixture can be prepared by contacting an acidic phenol with a peroxide-containing compound and a solvent. Alternatively, the acidic mixture can be prepared by contacting an acidic phenol with one or more carboxylic acids and an optional peroxide-containing compound and a solvent.

In one aspect, the STM is prepared by sequentially adding a titanium-containing compound and a nitrogen-containing compound to an acidic mixture as disclosed herein. In another aspect, the STM is prepared by adding a titanium-containing compound to an acidic mixture as disclosed herein. In some aspects, the order of addition is any order that is compatible with the materials disclosed herein. For example, any STM may include any of the components disclosed herein (e.g., an acidic phenol, a nitrogen-containing compound, a peroxide-containing compound, a carboxylic acid), a titanium-containing compound, and a chromium-containing compound.

In an alternative aspect, a titanium-containing compound and a nitrogen-containing compound can be contacted to form a basic mixture, which is then contacted with an acidic mixture to form a STM as disclosed herein. In another aspect, the nitrogen-containing compound used to form the basic mixture can be a component of an aqueous solution.

In one aspect, the STM comprises one or more carboxylic acids, alternatively, one or more acidic phenols, alternatively, a combination of one or more acidic phenols and one or more carboxylic acids, all of which are of the type disclosed herein. In one aspect, the STM of the present disclosure comprises an acidic mixture having a weight ratio of solvent to carboxylic acid in the range of about 1:1 to about 100:1; alternatively, about 1:1 to about 50:1; or alternatively, about 1:1 to about 10:1. In another aspect, the STM comprises an equivalent molar ratio of titanium-containing compounds to carboxylic acids in the range of about 1:0.5 to about 1:20; alternatively, about 1:1 to about 1:10; or alternatively, about 1:1 to about 1:5. In some aspects, the equivalent molar ratio of titanium-containing compounds to carboxylic acids may be about 1:2.5. In another aspect, the STM comprises an equivalent molar ratio of nitrogen-containing compounds to carboxylic acids in the range of about 0.1:1 to about 5:1; alternatively, about 0.5:1 to about 3:1; alternatively, about 1:1 to about 2:1; or alternatively, about 1:1 to about 2:1. In another aspect, the STM comprises an equivalent molar ratio of titanium-containing compounds to peroxide-containing compounds in the range of about 1:0.5 to about 1:50; alternatively, about 1:1 to about 1:20; alternatively, about 1:5 to about 1:10; or alternatively, about 1:3 to about 1:8. In another aspect, the STM comprises an equivalent molar ratio of titanium-containing compounds to acidic phenols in the range of about 1:0.5 to about 1:10; alternatively, about 1:1 to about 1:5; alternatively, about 1:1 to about 1:3; or alternatively, about 1:1 to about 1:2.5.

In another aspect, the STM comprises an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the range of about 1:0.5 to about 1:10; alternatively, about 1:1 to about 1:5; alternatively, about 1:1 to about 1:3; or alternatively, about 1:1 to about 1:2.5. In other aspects, the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound may be about 1:2.

In a particular aspect, the STM suitable for use in the present disclosure may be characterized as having a pH of less than about 5.5. Alternatively, the STM may be characterized as having a pH in the range of about 2.5 to about 5.5; alternatively, about 3.0 to about 5.0; or alternatively, about 3.5 to about 4.5.

In one aspect of the present disclosure, the catalyst components disclosed herein can be contacted in any order or manner deemed suitable by one of ordinary skill in the art in light of the present disclosure to produce an olefin polymerization catalyst having the characteristics disclosed herein.

In a particular aspect, a method for preparing an olefin polymerization catalyst comprises contacting a solvent and one or more carboxylic acids to form an acidic mixture, wherein the solvent and the carboxylic acid are of the type disclosed herein. The method may also include contacting a titanium-containing compound of the type disclosed herein with an acidic mixture to form an acidic titanium mixture. In one aspect, a nitrogen-containing compound of the type disclosed herein and an acidic titanium mixture may be contacted to form an STM as disclosed herein, for example, the nitrogen-containing compound may be added to an acidic titanium mixture to form the STM. In some aspects, the nitrogen-containing compound is added to the acidic titanium mixture in a single portion in an amount sufficient to form an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2 in the STM. In a particular aspect, the amount of the nitrogen-containing compound to be added to the acidic titanium mixture is determined using an acid-base indicator (e.g., bromocresol green), wherein the nitrogen-containing compound is added to the acidic titanium mixture in multiple portions, and wherein the single portion accounts for about 3% to about 10% of the amount of the nitrogen-containing compound constituting an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2. When the green endpoint of the bromocresol green indicator is reached, the addition of multiple nitrogen-containing compounds can be stopped. In some aspects, the green endpoint of the bromocresol green indicator is associated with a pH value of about 4.0 in the STM. On the other hand, adding the nitrogen-containing compound to the acidic titanium mixture includes partially neutralizing the acidic titanium mixture; or alternatively, completely neutralizing the acidic titanium mixture. The method for preparing an olefin polymerization catalyst may also include contacting a chromium-silica support of the type disclosed herein with an STM to form an addition product. On the other hand, the addition product may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a precatalyst.

On the other hand, a method for preparing an olefin polymerization catalyst includes contacting a solvent and one or more carboxylic acids to form an acidic mixture, the solvent and the carboxylic acid both being of the type disclosed herein. The method may also include contacting a titanium-containing compound of the type disclosed herein with an acidic mixture to form an acidic titanium mixture. On the one hand, a nitrogen-containing compound of the type disclosed herein and an acidic titanium mixture may be contacted to form an STM as disclosed herein, for example, the nitrogen-containing compound may be added to an acidic titanium mixture to form the STM. In some aspects, the nitrogen-containing compound is added to the acidic titanium mixture in a single portion in an amount sufficient to form an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2 in the STM. In a specific aspect, the amount of the nitrogen-containing compound to be added to the acidic titanium mixture is determined using an acid-base indicator (e.g., bromocresol green), wherein the nitrogen-containing compound is added to the acidic titanium mixture in multiple portions, and wherein the single portion accounts for about 3% to about 10% of the amount of the nitrogen-containing compound constituting an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2. When the green endpoint of the bromocresol green indicator is reached, the addition of the plurality of nitrogen-containing compounds can be stopped. In some aspects, the green endpoint of the bromocresol green indicator is associated with a pH value of about 4.0 in the STM. In another aspect, adding the nitrogen-containing compound to the acidic titanium mixture comprises partially neutralizing the acidic titanium mixture; or alternatively, completely neutralizing the acidic titanium mixture.

The method for preparing an olefin polymerization catalyst may also include contacting a silica support of the type disclosed herein and an STM to form a titanated support. On the other hand, the titanated support may be dried by heating the titanated support to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the titanated support in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a dried titanated support. The method may also include contacting a chromium-containing compound of the type disclosed herein and a dried titanated support to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In an alternative aspect, before drying the titanated support as disclosed herein, the chromium-containing compound and the titanated support may be contacted to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In another alternative aspect, a chromium-containing compound and a silica support can be contacted to form a chromium-silica support, the chromium-silica support can be contacted with an STM to form an addition product, and the addition product can be dried by heating the addition product to a temperature in the range of about 25° C. to about 300° C.; alternatively, about 50° C. to about 150° C.; or alternatively, about 75° C. to about 100° C. The method also includes maintaining the temperature of the addition product in the range of about 25° C. to about 300° C.; alternatively, about 50° C. to about 150° C.; or alternatively, about 75° C. to about 100° C. for a period of about 30 minutes to about 6 hours to form the procatalyst.

On the other hand, a method for preparing an olefin polymerization catalyst includes contacting a titanium-containing compound and a nitrogen-containing compound to form an alkaline mixture, the titanium-containing compound and the nitrogen-containing compound both belonging to the types disclosed herein. The method may also include contacting a solvent and a carboxylic acid to form an acidic mixture, the solvent and the carboxylic acid both belonging to the types disclosed herein. The alkaline mixture and the acidic mixture may be contacted to form a dissolved titanium mixture (STM) as disclosed herein, for example, the alkaline mixture may be added to the acidic mixture to form an STM. In some aspects, the alkaline mixture is added to the acidic mixture in a single portion in an amount sufficient to form an equivalent molar ratio of titanium-containing compounds to carboxylic acids of about 1:2. In a specific aspect, the amount of the alkaline mixture to be added to the acidic mixture is determined with an acid-base indicator (e.g., bromocresol green), wherein the alkaline mixture is added to the acidic mixture in multiple portions, and wherein the single portion accounts for about 3% to about 10% of the amount of the alkaline mixture constituting an equivalent molar ratio of titanium-containing compounds to carboxylic acids of about 1:2. When the green endpoint of the bromocresol green indicator is reached, the addition of the multiple alkaline mixtures can be stopped. In some aspects, the green endpoint of the bromocresol green indicator is associated with a pH value of about 4.0 in the STM. On the other hand, adding the alkaline mixture to the acidic mixture includes partially neutralizing the acidic mixture; or alternatively, completely neutralizing the acidic mixture. The method for preparing an olefin polymerization catalyst may also include contacting a chromium-silica support of the type disclosed herein with an STM to form an addition product. On the other hand, the addition product may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the addition product at a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a precatalyst.

On the other hand, a method for preparing an olefin polymerization catalyst includes contacting a titanium-containing compound and a nitrogen-containing compound to form an alkaline mixture, the titanium-containing compound and the nitrogen-containing compound both belonging to the types disclosed herein. The method may also include contacting a solvent and a carboxylic acid to form an acidic mixture, the solvent and the carboxylic acid both belonging to the types disclosed herein. The alkaline mixture and the acidic mixture may be contacted to form a dissolved titanium mixture (STM) as disclosed herein, for example, the alkaline mixture may be added to the acidic mixture to form an STM. In some aspects, the alkaline mixture is added to the acidic mixture in a single portion in an amount sufficient to form an equivalent molar ratio of titanium-containing compounds to carboxylic acids of about 1:2. In a specific aspect, the amount of the alkaline mixture to be added to the acidic mixture is determined with an acid-base indicator (e.g., bromocresol green), wherein the alkaline mixture is added to the acidic mixture in multiple portions, and wherein the single portion accounts for about 3% to about 10% of the amount of the alkaline mixture constituting an equivalent molar ratio of titanium-containing compounds to carboxylic acids of about 1:2. When the green endpoint of the bromocresol green indicator is reached, the addition of the multiple alkaline mixtures can be stopped. In some aspects, the green endpoint of the bromocresol green indicator is associated with a pH value of about 4.0 in the STM. On the other hand, adding the alkaline mixture to the acidic mixture includes partially neutralizing the acidic mixture; or alternatively, completely neutralizing the acidic mixture. The method for preparing an olefin polymerization catalyst may also include contacting a silica support of the type disclosed herein with an STM to form a titanated support. On the other hand, the titanated support may be dried by heating the titanated support to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the titanated support in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a dried titanated support. The method may also include contacting a chromium-containing compound of the type disclosed herein and a dried titanated support to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In an alternative aspect, prior to drying the titanated support as disclosed herein, the chromium-containing compound and the titanated support may be contacted to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In another alternative aspect, the chromium-containing compound and the silica support can be contacted to form a chromium-silica support, the chromium-silica support can be contacted with STM to form the addition product, and the addition product can be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst.

On the other hand, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, one or more carboxylic acids, one or more nitrogen-containing compounds and a peroxide-containing compound to form an acidic mixture, wherein the solvent, the carboxylic acid, the nitrogen-containing compound and the peroxide-containing compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, one or more acidic phenols, a nitrogen-containing compound and a peroxide-containing compound to form an acidic mixture, wherein the solvent, the acidic phenol, the nitrogen-containing compound and the peroxide-containing compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, one or more carboxylic acids, one or more acidic phenols, one or more nitrogen-containing compounds and a peroxide-containing compound to form an acidic mixture, wherein the solvent, the carboxylic acid, the acidic phenol, the nitrogen-containing compound and the peroxide-containing compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, one or more carboxylic acids, one or more acidic phenols and a peroxide-containing compound to form an acidic mixture, wherein the solvent, the carboxylic acid, the acidic phenol and the peroxide-containing compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, one or more acidic phenols, one or more nitrogen-containing compounds and a peroxide-containing compound to form an acidic mixture, wherein the solvent, the acidic phenol, the nitrogen-containing compound and the peroxide-containing compound are each of the types disclosed herein. The method may also comprise contacting a titanium-containing compound of the type disclosed herein and the acidic mixture to form an acidic titanium mixture.

In one aspect, a nitrogen-containing compound of the type disclosed herein and an acidic titanium mixture can be contacted to form a solubilized titanium mixture (STM) as disclosed herein, for example, the nitrogen-containing compound can be added to the acidic titanium mixture to form the STM. In some aspects, the nitrogen-containing compound is added to the acidic titanium mixture in a single portion in an amount sufficient to form an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2 in the STM. In a specific aspect, the amount of the nitrogen-containing compound to be added to the acidic titanium mixture is determined using an acid-base indicator (e.g., bromocresol green), wherein the nitrogen-containing compound is added to the acidic titanium mixture in multiple portions, and wherein the single portion accounts for about 3% to about 10% of the amount of the nitrogen-containing compound constituting an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound of about 1:2. When the green endpoint of the bromocresol green indicator is reached, the addition of multiple portions of the nitrogen-containing compound can be stopped. In some aspects, the green endpoint of the bromocresol green indicator is associated with a pH value of about 4.0 in the STM. In another aspect, adding the nitrogen-containing compound to the acidic titanium mixture comprises partially neutralizing the acidic titanium mixture; or alternatively, completely neutralizing the acidic titanium mixture. The method for preparing an olefin polymerization catalyst may also include contacting a silica support of the type disclosed herein with an STM to form a titanated support. In another aspect, the titanated support may be dried by heating the titanated support to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the titanated support in the range of 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a dried titanated support. The method may also include contacting a chromium-containing compound of the type disclosed herein and a dried titanated support to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In an alternative aspect, prior to drying the titanated support as disclosed herein, the chromium-containing compound and the titanated support may be contacted to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In another alternative aspect, the chromium-containing compound and the silica support can be contacted to form a chromium-silica support, the chromium-silica support can be contacted with STM to form the addition product, and the addition product can be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst.

On the other hand, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, a carboxylic acid, and a peroxy compound to form an acidic mixture, wherein the solvent, the carboxylic acid, and the peroxy compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, an acidic phenol, and a peroxy compound to form an acidic mixture, wherein the solvent, the acidic phenol, and the peroxy compound are each of the types disclosed herein. Alternatively, a method for preparing an olefin polymerization catalyst comprises contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxy compound to form an acidic mixture, wherein the solvent, the carboxylic acid, the acidic phenol, and the peroxy compound are each of the types disclosed herein.

The method may also include contacting a titanium-containing compound of the type disclosed herein with an acidic mixture to form an acidic titanium mixture. The method for preparing an olefin polymerization catalyst may also include contacting a silica support of the type disclosed herein with an STM to form a titanated support. On the other hand, the titanated support may be dried by heating the titanated support to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the titanated support in the range of 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form a dried titanated support. The method may also include contacting a chromium-containing compound of the type disclosed herein and a dried titanated support to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining the temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In an alternative aspect, prior to drying the titanated support as disclosed herein, the chromium-containing compound and the titanated support may be contacted to form an addition product, which may be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst. In another alternative aspect, the chromium-containing compound and the silica support can be contacted to form a chromium-silica support, the chromium-silica support can be contacted with STM to form the addition product, and the addition product can be dried by heating the addition product to a temperature in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C. The method also includes maintaining a temperature of the addition product in the range of about 25°C to about 300°C; alternatively, about 50°C to about 150°C; or alternatively, about 75°C to about 100°C for a period of about 30 minutes to about 6 hours to form the procatalyst.

It may be advantageous to utilize a dissolved titanium mixture (STM) in the preparation of the olefin polymerization catalyst of the present disclosure, because the STM may contribute to the association of titanium with a silica support in the presence of an aqueous solvent (e.g., water). Other advantages may exist when the STM used to form the olefin polymerization catalyst comprises an aqueous solvent (e.g., water). The solubility of titanium in an aqueous solvent may be sufficient to allow the use of a spray drying method to contact the STM with a silica support. Spray drying as used herein refers to a method of producing a dry powder from a liquid or slurry by rapid drying with hot gas. Spray drying methods may be used to prepare olefin polymerization catalysts in a continuous production process, with the potential to produce a large amount of olefin polymerization catalysts. Spray drying methods may also be used to prepare olefin polymerization catalysts with a consistent particle size distribution. The use of an STM comprising an aqueous solvent may allow the use of a hydrated silica support, and eliminates the thermal treatment required for an anhydrous catalyst preparation method (e.g., drying the hydrated silica support before contacting with any other catalyst component).

As will be appreciated by one of ordinary skill in the art, calcining the procatalysts disclosed herein can result in the emission of volatile organic compounds (VOCs). In various aspects of the present disclosure utilizing peroxides in the absence of nitrogen-containing compounds, the emission of VOCs is reduced when compared to an otherwise similar catalyst preparation performed in the presence of a nitrogen-containing compound. In one aspect, the VOC emissions achieved by the catalysts of the present disclosure can be reduced by equal to or greater than about 10%, alternatively, equal to or greater than about 20%, or alternatively, equal to or greater than about 30%, when compared to an otherwise similar catalyst preparation performed in the presence of a nitrogen-containing compound.

In some aspects of the present disclosure, the contact of the components for preparing an olefin polymerization catalyst may be carried out in the presence of a reaction medium. On the other hand, the reaction medium may be formed during the contact of the components for preparing an olefin polymerization catalyst. The reaction medium may include a solvent (e.g., water) as disclosed herein and one or more liquids associated with the components for preparing an olefin polymerization catalyst (e.g., water associated with a silica support). On the one hand, the reaction medium excludes any solid components (e.g., a silica support and any solids associated therewith) for preparing an olefin polymerization catalyst disclosed herein. In some aspects, based on the gross weight of the reaction medium, the total amount of water present in the reaction medium may be in the range of about 1wt% to about 99wt%; alternatively, about 1wt% to about 50wt%; alternatively, about 1wt% to about 20wt%; or alternatively, about 1wt% to about 10wt%. In another aspect, the reaction medium may contain greater than about 20 wt % water; alternatively, about 40 wt % water; alternatively, about 60 wt % water; alternatively, about 80 wt % water; or alternatively, about 90 wt % water, based on the total weight of the reaction medium, wherein the water may be derived from one or more components used to prepare the olefin polymerization catalyst.

In any aspect of the present disclosure, a method for preparing an olefin polymerization catalyst further comprises activating the procatalyst prepared as disclosed herein by a calcination step. In some aspects, the calcination of the procatalyst comprises heating the procatalyst in an oxidizing environment to produce an olefin polymerization catalyst. For example, the procatalyst may be calcined by heating the procatalyst in the presence of air to a temperature in the range of about 400°C to about 1000°C; alternatively, about 500°C to about 900°C; or alternatively, about 500°C to about 850°C. Calcination of the procatalyst may also include maintaining the procatalyst at a temperature in the range of about 400°C to about 1000°C; alternatively, about 500°C to about 900°C; or alternatively, about 500°C to about 850°C in the presence of air for a period of time in the range of about 1 minute to about 24 hours; alternatively, about 1 minute to about 12 hours; alternatively, about 20 minutes to about 12 hours; alternatively, about 1 hour to about 10 hours; alternatively, about 3 hours to about 10 hours; or alternatively, about 3 hours to about 5 hours to produce an olefin polymerization catalyst.

The olefin polymerization catalyst of the present disclosure is suitable for use in any olefin polymerization method using various types of polymerization reactors. In one aspect of the present disclosure, the polymer of the present disclosure is produced by any olefin polymerization method using various types of polymerization reactors. As used herein, "polymerization reactor" includes any reactor capable of polymerizing olefin monomers to produce homopolymers and/or copolymers. The homopolymers and/or copolymers produced in the reactor may be referred to as resins and/or polymers. Various types of reactors include, but are not limited to, those that may be referred to as batch reactors, slurry reactors, gas phase reactors, solution reactors, high pressure reactors, tubular reactors, autoclave reactors, or other reactors and/or multiple reactors. The gas phase reactor may include a fluidized bed reactor or a graded horizontal reactor. The slurry reactor may include vertical and/or horizontal loops. The high pressure reactor may include autoclaves and/or tubular reactors. The reactor type may include intermittent and/or continuous processes. The continuous process may use intermittent and/or continuous product discharge or transfer. The process may also include partial or complete direct recycling of unreacted monomers, unreacted comonomers, olefin polymerization catalysts and/or cocatalysts, diluents and/or other materials of the polymerization process.

The polymerization reactor system of the present disclosure may include a type of reactor in the system operated in any suitable configuration, or multiple reactors of the same or different types. Producing polymers in multiple reactors may include several stages in at least two separate polymerization reactors interconnected by a transfer system, which makes it possible to transfer the polymer produced by the first polymerization reactor to the second reactor. Alternatively, polymerization in multiple reactors may include manually or automatically transferring the polymer from one reactor to subsequent one or more reactors for additional polymerization. Alternatively, multi-stage or multi-step polymerization may occur in a single reactor, wherein conditions are changed so that different polymerization reactions occur.

The required polymerization conditions in a reactor may be the same or different from the operating conditions of any other reactor involved in the overall process for producing the polymer of the present disclosure. The multi-reactor system may include any combination, including but not limited to a combination of multiple loop reactors, multiple gas phase reactors, loop reactors and gas phase reactors, multiple high pressure reactors and a combination of high pressure reactors and loop reactors and/or gas reactors. Multiple reactors may be operated in series or in parallel. In one aspect of the present disclosure, any arrangement and/or any combination of reactors may be used to produce the polymer of the present disclosure.

According to one aspect of the present disclosure, the polymerization reactor system may include at least one loop slurry reactor. Such reactors are common and may include vertical or horizontal loops. Typically, a continuous process may include continuously introducing a monomer, an olefin polymerization catalyst, and/or a diluent into a polymerization reactor, and continuously removing a suspension comprising polymer particles and the diluent from this reactor. Monomers, diluents, olefin polymerization catalysts, and optionally any comonomers may be continuously fed to a loop slurry reactor, where polymerization occurs. The reactor effluent may be flashed to remove a liquid comprising a diluent from solid polymers, monomers, and/or comonomers. Various techniques may be used for this separation step, including but not limited to flashing that may include any combination of heating and decompression; separation by cyclonic action in a cyclone separator or hydrocyclone separator; separation by centrifugation; or other suitable separation methods.

Typical slurry polymerization processes (also referred to as particle form processes) are disclosed, for example, in U.S. Pat. Nos. 3,248,179, 4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, and 6,833,415; each of which is incorporated herein by reference in their entirety.

Diluents suitable for use in slurry polymerization include, but are not limited to, the monomer being polymerized and hydrocarbons that are liquid under the reaction conditions. Examples of suitable diluents include, but are not limited to, hydrocarbons such as propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, and n-hexane. Some loop polymerization reactions can occur under bulk conditions where no diluent is used. An example is the polymerization of propylene monomers as disclosed in U.S. Patent No. 5,455,314, which is incorporated herein by reference in its entirety.

According to another aspect of the present disclosure, the polymerization reactor may include at least one gas phase reactor. Such a system may employ a continuous recycle stream containing one or more monomers, which is continuously circulated through a fluidized bed under polymerization conditions in the presence of an olefin polymerization catalyst. The recycle stream may be discharged from the fluidized bed and recycled back into the reactor. At the same time, the polymer product may be discharged from the reactor, and fresh monomers may be added to replace the polymerized monomers. Such a gas phase reactor may include a process for multi-step gas phase polymerization of olefins, wherein olefins are polymerized in a gas phase in at least two independent gas phase polymerization zones, while the polymer containing an olefin polymerization catalyst formed in the first polymerization zone is fed to the second polymerization zone. A type of gas phase reactor suitable for use is disclosed in U.S. Patents 4,588,790, 5,352,749 and 5,436,304, each of which is incorporated herein by reference in its entirety.

According to another aspect of the present disclosure, the high pressure polymerization reactor may include a tubular reactor or an autoclave reactor. The tubular reactor may have several zones in which fresh monomers, initiators, or olefin polymerization catalysts are added. The monomers may be entrained in an inert gas stream and introduced in one zone of the reactor. Initiators, olefin polymerization catalysts, and/or catalyst components may be entrained in a gas stream and introduced in another zone of the reactor. The gas streams may be intermixed for polymerization. Heat and pressure may be appropriately used to obtain optimal polymerization conditions.

According to another aspect of the present disclosure, the polymerization reactor may include a solution polymerization reactor in which the monomer is contacted with the olefin polymerization catalyst composition by suitable stirring or other means. A carrier comprising an organic diluent or excess monomer may be used. If desired, the monomer may be introduced into the vapor phase and contacted with the catalytic reaction product in the presence or absence of a liquid material. The polymerization zone is maintained at a temperature and pressure that will result in the formation of a solution of the polymer in the reaction medium. Stirring may be used to obtain better temperature control, and a uniform polymerization mixture is maintained throughout the polymerization zone. Suitable means are utilized to dissipate the polymerization exotherm.

The polymerization reactor suitable for use in the present disclosure may also include any combination of at least one raw material feed system, at least one feed system for olefin polymerization catalyst or catalyst components and/or at least one polymer recovery system. The reactor system suitable for the present disclosure may also include systems for raw material purification, catalyst storage and preparation, extrusion, reactor cooling, polymer recovery, fractionation, recycling, storage, discharge, laboratory analysis and process control.

Conditions controlled in order to achieve polymerization efficiency and provide polymer properties include, but are not limited to, temperature, pressure, the type and quantity of olefin polymerization catalysts or cocatalysts, and the concentrations of various reactants. The polymerization temperature can affect catalyst productivity, polymer molecular weight and molecular weight distribution. According to the Gibbs Free Energy Equation, a suitable polymerization temperature can be any temperature below the depolymerization temperature. Typically, depending on the type of polymerization reactor and/or the polymerization process, this includes, for example, about 60°C to about 280°C, and/or about 70°C to about 110°C.

Suitable pressures will also vary depending on the reactor and polymerization process. The pressure used for liquid phase polymerization in a loop reactor is generally less than 1000 psig (6.9 MPa). The pressure used for gas phase polymerization is generally in the range of about 200 psig (1.4 MPa)-500 psig (3.45 MPa). High pressure polymerization in a tubular or autoclave reactor is generally operated in the range of about 20,000 psig (138 MPa) to 75,000 psig (518 MPa). It is also possible to operate a polymerization reactor in a supercritical region occurring at generally higher temperatures and pressures. Operating under conditions (supercritical phase) above the critical point as indicated by a pressure/temperature diagram can provide advantages.

The concentrations of the various reactants can be controlled to produce polymers with certain physical and mechanical properties. The proposed end-use product to be formed from the polymer and the method of forming that product can be varied to determine the desired end-product properties. Mechanical properties include, but are not limited to, tensile strength, flexural modulus, impact resistance, creep, stress relaxation, and hardness test values. Physical properties include, but are not limited to, density, molecular weight, molecular weight distribution, melting temperature, glass transition temperature, melt crystallization temperature, density, stereoregularity, crack growth, short chain branching, long chain branching, and rheological measurements.

The concentrations of monomers, comonomers, hydrogen, cocatalysts, modifiers, and electron donors are often important in producing specific polymer properties. Comonomers can be used to control product density. Hydrogen can be used to control product molecular weight. Cocatalysts can be used for alkylation, removal of poisons, and/or control of molecular weight. The concentration of poisons can be minimized because poisons can affect the reaction and/or otherwise affect the polymer product properties. Modifiers can be used to control product properties, and electron donors can affect stereoregularity.

Olefin polymerization catalysts prepared as described herein can be used to produce polymers in the above manner, such as polyethylene homopolymers and copolymers of ethylene and other monoolefins. Techniques known in the art such as extrusion, blow molding, injection molding, fiber spinning, thermoforming and casting can be used to form polymers produced as disclosed herein into articles or end-use items. For example, the polymer resin can be extruded into a sheet, which is then thermoformed into an end-use item, such as a container, a cup, a plate, a tray, a toy, or a part of another product. Examples of other end-use items that the polymer resin can form include pipes, films and bottles.

A disclosed process comprises contacting an olefin polymerization catalyst of the type described with an olefin monomer under conditions suitable for forming a polyolefin, and recovering the polyolefin. In one aspect, the olefin monomer is an ethylene monomer and the polyolefin is an ethylene polymer (polyethylene).

The polyethylene prepared as described herein can be characterized as having a high load melt index (HLMI) in the range of about 1 g/10 min to about 1000 g/10 min; alternatively, about 3 g/10 min to about 300 g/10 min; alternatively, about 6 g/10 min to about 100 g/10 min; or alternatively, about 15 g/10 min to about 40 g/10 min. In another aspect, the polyethylene prepared as described herein can be characterized as having a HLMI that is about 1.5 to about 15 times greater than the HLMI of a polymer produced using an otherwise similar olefin polymerization catalyst that does not contain titanium.

In a particular aspect, polyethylene can be prepared using a dealtitanation catalyst produced from a water-extracted procatalyst. In another aspect, the water-extracted procatalyst is a procatalyst extracted with water prior to calcination. For example, a procatalyst prepared as described herein can be extracted with water and subsequently calcined to provide a dealtitanation catalyst (i.e., an olefin polymerization catalyst derived from a water-extracted procatalyst). In another aspect, the polyethylene prepared using the dealtitanation catalyst can be characterized by having an HLMI in the range of about 1 dg/min to about 7 dg/min. Such an HMLI value can indicate that the dealtitanation catalyst has an amount of titanium in the range of about 0 wt% to about 1 wt% based on the amount of silica; or alternatively, about 0.1 wt% to about 0.5 wt%.

Melt index (MI) represents the flow rate of molten polymer through an orifice having a diameter of 0.0825 inches when subjected to a force of 2,160 grams at 190°C as determined according to ASTM D1238-82, Condition E. I10 represents the flow rate of molten polymer through an orifice having a diameter of 0.0825 inches when subjected to a force of 10,000 grams at 190°C as determined according to ASTM D1238-82, Condition N. HLMI (high load melt index) represents the flow rate of molten polymer through an orifice having a diameter of 0.0825 inches when subjected to a force of 21,600 grams at 190°C as determined according to ASTM D1238-82, Condition F.

Example

The following examples are given as specific aspects of the present disclosure and are used to illustrate the practice and advantages of the present disclosure. It should be understood that the examples are given by way of illustration and are not intended to limit the specification or the claims that follow in any way.

Those skilled in the art will appreciate that the surfaces of oxides including silicon dioxide (SiO ₂ ) and titanium dioxide (TiO ₂ ) are typically terminated with hydroxyl groups which are protic groups that can participate in acid-base reactions. Under strongly acidic conditions, the hydroxyl groups can be protonated to produce a positive charge on the oxide surface. Under strongly basic conditions, the hydroxyl groups can be deprotonated to produce a negative charge on the oxide surface. Somewhere between the two extremes there is a pH value at which there is a zero net charge on the oxide surface. The pH value associated with zero net charge is the isoelectric point. Each oxide has a characteristic acidity and a specific isoelectric point that is controlled by the chemical nature of the metal or non-metal element of the oxide.

The accompanying drawings show the zeta potentials that vary with the pH value of the solution of silicon dioxide and titanium dioxide and the isoelectric point values of the two oxides. The curve of the coulombic Si-Ti attraction is also shown. The zeta potential is the charge potential difference between the surface of the solid particles immersed in the conductive liquid (such as water) and the main body of the liquid. The accompanying drawings are shown in the region where the pH value is between 3.0 and 5.0, and titanium dioxide is positively charged, while silicon dioxide is negatively charged. The accompanying drawings also indicate that the coulombic Si-Ti attraction is the maximum near the pH value of about 4.0. Without wishing to be limited by theory, when the coulombic Si-Ti attraction is maximized at about 4.0 by maintaining the pH value of the solution, it can cause the highly effective titanation of olefin polymerization catalysts from Ti aqueous solutions. For exploring this theory, several series of experiments have been carried out to establish the conditions that cause the formation of Ti aqueous solutions with a pH value of about 4.0.

All silica support materials, chemical reagents, and solvents described herein were used as received and were not dried prior to use.

The catalysts used in the experiments described below include It is a commercial Cr/silica-titania catalyst obtained from WR Grace and Company and activated at various temperatures. Prepared by ternary gelation of Si, Ti and Cr, containing 2.5 wt% Ti and 1 wt% Cr, with a surface area of about 500 ^m2 /g, a pore volume of 2.5 mL/g and an average particle size of about 130 microns. Another commercial Cr/silica-titania catalyst used is called C-25305HM, obtained from Philadelphia Quartz (PQ) Corporation. It also contains 2.5 wt% Ti and 1 wt% Cr, with a surface area of about 500 ^m2 /g, a pore volume of 2.7 mL/g and an average particle size of about 100 microns. The main base catalyst used for the titanation described below is HA30W, which is a commercial Cr/silica obtained from WRGrace. This catalyst does not contain titanium, but does contain 1 wt% Cr. It has a surface area of about 500 ^m2 /g, a pore volume of about 1.6 mL/g, and an average particle size of about 100 microns. Three other commercial Cr/silica catalysts were also used; one catalyst is called EP30X and is from PQ Corporation; another catalyst is from Asahi Glass Corporation (AGC) under the trade name D-70-150A (LV); and the third catalyst is from WRGrace 969MPI. All three of these catalysts do not contain titanium, but do contain 1 wt% Cr. All three have a pore volume of about 1.6 mL/g. EP30X and 969MPI have a surface area of about 300 ^m2 /g and an average particle size of about 100 microns. AGC D-70-150A (LV) has a surface area of about 400 ^m2 /g and an average particle size of about 80 microns.

Activity tests were carried out in a 2.2 liter steel reactor equipped with a marine agitator running at 400 rpm. The reactor was surrounded by a steel jacket circulating water whose temperature was controlled by using steam and water heat exchangers. These were connected in an electronic feedback loop so that the reactor temperature could be maintained at +/- 0.5°C during the reaction.

Unless otherwise stated, a small amount (usually 0.01 to 0.10 grams) of solid chromium catalyst is first loaded into a dry reactor under nitrogen. Next, about 0.25 g of sulfate-treated alumina (600° C.) is added as a poison scavenger. 1.2 liters of isobutane liquid is then loaded, and the reactor is heated to a specified temperature, typically 105° C. Finally, ethylene is added to the reactor to reach a fixed pressure, typically 550 psig (3.8 MPa), which is maintained during the experiment. Agitation is continued for a specified time, typically about one hour, and activity is indicated by recording the flow of ethylene into the reactor to maintain the set pressure.

After the allotted time, the ethylene flow was stopped and the reactor was slowly depressurized and opened to recover the granular polymer powder. In all cases, the reactor was clean without any indication of wall scale, coating or other forms of fouling. The polymer powder was then removed and weighed. The activity was specified as grams of polymer produced per gram of solid catalyst charged per hour.

Example 1

Several control tests were conducted, and the results of the control tests are listed in Table 1. The performance of the experimental catalysts shown in other embodiments in terms of productivity, activity and melt index potential can be compared with these control tests. Tests 1.10-1.13 show the performance of two non-titanated catalysts, wherein the latter HA30W provides a measure of the effectiveness of the titanating of tests 1.16-1.18. The titanating shown in tests 1.16-1.18 uses Ti(OiPr) ₄ to titanate HA30W. The titanating in test 1.15 exposes the carrier to TiCl ₄ vapor at 250° C. in an attempt to produce a titanating catalyst that is not contaminated by organic or alcohol byproducts. In both methods, the carrier must be dried to remove free water from the surface, typically by heat treatment at about 150° C. to about 800° C. Otherwise, titanium will react with free adsorbed water and is ineffective. In tests 1.15-1.18, the catalyst was dried at 200°C and subsequently titanated by gas phase or anhydrous solvent (usually heptane).

Example 2: Acidic titanation

The first series of experiments investigated the ability of carboxylic acids to form acidic Ti-containing solutions that provide effective titanation for olefin polymerization catalysts (i.e., catalysts) of the type disclosed herein. The results are listed in Table 2. All of these experiments started with a hydrated silica support that had not been subjected to heat treatment before contact with any other catalyst component. The listed carboxylic acids were mixed with water or an alternative solvent system as listed to form a solution, but in all cases, the solvent was not dried and no attempt was made to use anhydrous conditions. Ti(OiPr) ₄ was added, and when dissolution occurred, the acidic Ti-containing solution thus formed was impregnated onto a chromium-silica support (HA30W). The product was then dried and calcined in air at 650°C for three hours and then used in polymerization experiments.

Table 2 summarizes the study of various carboxylic acids. Using carboxylic acids alone (without adding base) does not produce extremely effective titanation. Experiment 2.2 using acetic acid in propanol solvent provides the most effective titanation. Successful results were also observed when HA30W was impregnated with an acidic Ti-containing solution and dripped into a 300°C activation tube ("hot drop", experiments 2.12-2.16). This fast drying method is moderately effective, as demonstrated by the higher melt index obtained when using this method to produce catalysts compared to oven drying. When citric acid was used instead of oxalic acid, the "hot drop" drying method resulted in more effective titanation. This result can occur because the first pK _a (3.13) of citric acid is higher than the first pK _a (1.23) of oxalic acid. The lower acidity of citric acid can produce a Ti-containing solution with a higher and closer pH value to 4.0 when compared to the Ti-containing solution produced with oxalic acid.

Example 3: Alkaline titanation

The next series of experiments investigated the ability of the base to form an alkaline Ti-containing solution capable of providing effective titanation of the catalyst. The results are listed in Table 3. The experimental method was essentially the same as that described in Example 2. Ti dissolved in some strong bases such as organic bases was effective, but ammonium hydroxides and alkali metal hydroxides were not effective. Quaternary ammonium hydroxides dissolved Ti, but uncharged primary, secondary or tertiary amines were less effective. The melt index potentials resulting from the use of alkaline solutions were all lower, as were the non-titanate supports, and therefore did not show evidence of effective titanation of the chromium-silica support.

Example 4: pH Adjustment with Ammonium Hydroxide

The results in Tables 2 and 3 confirm that attaching titania to silica can be problematic at both high and low pH. The next series of experiments were conducted to explore the theory that the maximum Coulombic Si-Ti attraction occurs at a pH of about 4.0. Ti(OiPr) ₄ was hydrolyzed to titania dissolved in aqueous oxalic acid (2 equivalents of oxalic acid/Ti) to produce an acidic Ti-containing solution having a pH of about 1. Ammonium hydroxide or a quaternary ammonium derivative as listed in Table 4 was added until a green endpoint of a bromocresol green indicator indicating a pH of about 4.0 was reached to produce a solubilized Ti mixture (STM) of the type disclosed herein. The stoichiometry required to partially neutralize the acidic Ti-containing solution and thereby produce an STM is typically about two equivalents of base/Ti. The HA30W support was impregnated with the STM, and the product was dried and calcined at 650° C. in air for three hours before being used in polymerization experiments.

The results listed in Table 4 indicate that the method is successful. Quaternary ammonium hydroxides are more effective when compared to ammonium hydroxide. This result can be explained by the lower volatility of tetraalkylammonium hydroxides. The results in Table 4 also indicate that the amount of alkali used to prepare STM affects the melt index potential given by the resulting catalyst. The method also allows effective titanation on hydrogels rather than preformed silica supports (Test 4.16). The catalyst of Test 4.6 was prepared by reverse addition, and the catalyst showed excellent performance: Ti was dissolved in an aqueous solution of NMe ₄ OH to form an alkaline solution, which was added to an aqueous solution of oxalic acid to prepare an STM for impregnation of a HA30W support.

Example 5: pH adjustment with urea

The next series of experiments investigated the ability of urea to partially neutralize an acidic Ti-containing solution and produce an STM that can provide effective titanation to the catalyst. Urea is easily decomposed into volatile products after heating. Replacing the carbonaceous catalyst component with a urea compound is likely to reduce the emission of volatile organic compounds and highly reactive volatile organic compounds produced during the calcination of the catalyst. The experimental method is essentially the same as the method described in Example 4, but without the use of bromocresol green indicator. The results are shown in Table 5. Adding urea to an acidic Ti-containing solution provides increasingly effective titanation as the amount of urea increases. This effect was not observed in experiments studying the use of urea in spray drying applications, probably because urea decomposes and/or evaporates during the spray drying operation. Effective titanation was also observed in the case of N, N'-dimethylurea, which is less volatile than urea.

Example 6: pH Adjustment with Alkanolamines

The next series of experiments investigated the ability of alkanolamines to partially neutralize acidic Ti-containing solutions and produce STMs that can provide effective titanation to the catalyst. Ethanolamine and isopropanolamine were selected because they generally exhibit low toxicity, have low cost, are easily available from multiple sources, and have less odor than most amines. The experimental method was essentially the same as that described in Example 5, and the results are shown in Table 6. The results were variable, and the bulkier amines seemed to perform best. Without wishing to be limited by theory, this may be a result of the lower volatility of the bulkier compounds and/or the lower dielectric constant of the Ti ions produced by the bulkier compounds. Dimethylaminoethanol (DMAE) provides a relatively high melt index, is low cost, is available from multiple suppliers, and has less odor. The catalyst for Test 6.11 was prepared in the following manner: titanium dioxide was dissolved in two equivalents of aqueous oxalic acid, followed by the addition of two equivalents of DMAE to form a dissolved Ti solution (STM) of the type disclosed herein. The HA30W support was impregnated with STM to form a titanated support, which was dried overnight at 100°C under vacuum conditions. The resulting dried titanated support was extracted with water, subsequently calcined at 650°C, and subjected to polymerization experiments. The melt index data indicated that the catalyst had suffered a large loss of Ti, presumably during the water extraction step. This observation indicates that after drying at 100°C, Ti may not have been fully attached to silica, and supports previous observations that attachment between Ti and silica occurs at least in part at temperatures greater than 150°C.

Example 7: pH adjustment with other amines

The next series of experiments investigated the ability of various other amines to partially neutralize the acidic Ti-containing solution and produce an STM capable of providing effective titanation of the catalyst. The experimental method was essentially the same as that described in Example 5, and the results are shown in Table 7. A general trend of higher performance with bulkier amines was observed, but this was sometimes compromised by lack of solubility, such as in the case of 2-ethylhexylamine or DABCO. Bases capable of delocalizing the positive charge obtained upon protonation showed extremely good performance; examples include DBU, creatine, and imidazole.

Example 8: Adjusting pH with an inorganic base

The next series of experiments investigated the partial neutralization of acidic Ti-containing solutions with inorganic bases, and produced the ability of STMs that could provide effective titanation to the catalyst. The experimental method was substantially the same as that described in Example 5, and the results are shown in Table 8. This method is usually unsuccessful. Without wishing to be limited by theory, a higher dielectric constant may have become an influence, but the presence of divalent or trivalent metal cations may have disturbed the delicate balance of surface charge between silicon dioxide and titanium dioxide. Tests 8.2 and 8.3 were partially successful, and an equivalent amount of Al ions were introduced together with Ti ions. Three equivalents of oxalic acid were added to dissolve two equivalents of metal (1Ti(OiPr) ₄ +1Al(OH) ₃ ), which was a lower acid/metal ratio than in most other experiments described herein. Test 8.3 included partial neutralization of acid with tetraethylammonium hydroxide with an amount of 1.5 equivalents of alkali/Ti. Compared to in most other experiments described herein, this was a lower alkali/metal ratio, but an increase in HLMI was observed. Without wishing to be bound by theory, it may be easier to coat titanium dioxide onto alumina than onto silicon dioxide. Ti and Al are both metals, and the chemistry of the two is more similar in many respects than that of Ti and Si.

Example 9: Dissolution of Ti by other acids

The next series of experimental studies of carboxylic acids other than oxalic acid are partially neutralized, and produce the ability of STM that can provide effective titanating to catalyst.The experimental method is substantially the same as the method described in Example 4, and the results are shown in Table 9.Compared to the experiment using oxalic acid, the experiment is usually less successful.Several experiments add two equivalents of alkali/Ti, and this exceeds the required equivalent number for obtaining the pH value of 4.0, because the acid tested is weaker than oxalic acid.In other experiments, alkali is added until the green end point of bromocresol green indicator is reached, thereby indicating a pH value of 4.0.An example of this method is test 9.7, wherein citric acid and tetramethylammonium hydroxide are used to produce highly effective titanating, as demonstrated by nearly 30 HLMI values.Test 9.14 indicates that titanyl sulfate can be partially neutralized by DMAE to produce moderately effective titanating in the absence of carboxylic acid.

Example 10: Dissolution of Ti with Peroxide

The catalysts listed in Table 10 (Inventive Runs 10.1-10.43) were prepared much like those previously described herein, with the exception that a peroxide (usually _{H2O2 )} was also added to the formulation as a replacement for part or all of the amine or acid. In this way, the amount of amine used, and in some runs the amount of acid used, could be reduced, which in turn reduced costs and emissions, and produced polymers with higher HLMIs.

In these experiments, 30 g of a Cr/silica catalyst sold by WR Grace under the name HA30W was weighed out into a bowl. It had a surface area of about 500 ^m2 /g, a pore volume of about 1.6 mL/g, and it contained 1 wt% Cr. It was not predried in any way. 50 mL of deionized water was added to a 100 mL beaker, into which the organic acid was dissolved. A peroxide was then added to the solution, typically _{H2O2 ,} also in the inventive experiments. Then, 6.65 mL of titanium tetraisopropoxide was added to the aqueous solution, which caused it to immediately precipitate out as hydrated titanium dioxide. The amount of titanium added was equal to 3.5 wt% Ti, based on the weight of the dry Cr/silica. The amounts of acid and peroxide used in each experiment were different, but these amounts are listed in Table 10 as equivalents of acid or peroxide added per equivalent of titanium. The precipitated slurry was stirred until the titanium dioxide dissolved into an orange or dark red solution (when _H2O2 was present ₎ , typically after about 10 minutes. In cases when the titanium dioxide did not dissolve readily, stirring was continued for several hours before it was finally concluded that no soluble complex was formed and the experiment was terminated. These are some of the control runs in Table 10.

However, when a soluble complex is indeed formed, the next step is to add the nitrogen compound to the solution in some experiments, while in other experiments, no nitrogen compound is used. The nitrogen compound is always dissolved in the titanium solution. Similarly, the amount of the nitrogen compound is listed in Table 10 in the equivalent form of the nitrogen compound corresponding to each equivalent of titanium. Finally, the titanium solution is added to the Cr/silica in the bowl, and it is manually stirred for several minutes to produce a consistent moist (not wet) powder, that is, to achieve initial wetness. The bowl is then placed in a vacuum oven set at 100°C overnight. The next day, the dried catalyst powder is poured through a 40 mesh screen to break up any small soft lumps. The resulting sample of the titanium-containing catalyst is roasted at 650°C in dry air for 3 hours. It is then recovered under dry nitrogen and stored for later use.

Control 10.2 shows that although two equivalents of oxalic acid can dissolve titania, the HLMI obtained is better than the HLMI obtained from the Cr/silica catalyst in the absence of titania (Table 1, Run 1.12). In other words, titanation is ineffective with oxalic acid alone. Control 10.2 serves as a baseline for other later experiments. Any HLMI greater than 5-7 represents an improvement in the efficiency of the titanation procedure.

With reference to Table 10, it is observed that the addition of peroxide causes titanium dioxide to dissolve in many acids that do not dissolve Ti in the absence of peroxide. Some of these acids produce extremely high HLMIs. However, it can also be observed that even in cases where titanium dioxide can be dissolved without peroxide, the addition of peroxide still greatly improves the HLMI caused by the catalyst. In addition, when peroxide is added, in many experiments, the amount of nitrogen compound used can be reduced, or in some cases, the nitrogen compound can be completely eliminated. Because nitrogen compounds cause undesirable emissions during roasting, this reduction is a great improvement.

In Table 11, various combinations of organic acids (and/or nitrogen compounds) are used to attempt to further reduce emissions and maximize HLMI. In many of these experiments, _H2O2 has been further utilized to dissolve _Ti and reduce the aforementioned ability of nitrogen compounds or even acid ligands. In these experiments (Inventions 11.44 to 11.60), the catalyst was prepared exactly as described previously herein. That is, 30 g of Cr/silica was weighed into a bowl, and 50 mL of deionized water was measured into a 100 mL beaker. The acid was dissolved in the water along with _H2O2 when used. Then 6.65 mL of titanium tetraisopropoxide (3.5 wt% Ti based on the Cr/ _silica weight) was added, and it immediately precipitated out as hydrated titanium dioxide. However, after a brief stirring of about 10 minutes, the Ti dissolved. Then the nitrogen compound, if present, was added, and the solution was added to the dry catalyst to achieve incipient wetness. Drying and calcination were accomplished as described above.

Only in Inventive Experiment 11.44 was the protocol slightly different. Here, 30 g of silica was weighed into a bowl (instead of Cr/silica). The silica was EP30X from Philadelphia Quartz Corp., with a surface area of 300 ^m2 /g. Likewise, 50 mL of deionized water was measured into a beaker, to which was then added the acid, _{H2O2 ,} and 6.65 mL of titanium isopropoxide. After the Ti was dissolved, 1.25 g of basic chromium acetate was also added to the solution. The silica was then impregnated with the solution as described above. It was dried and calcined as described above. It should also be noted that acidic phenols can replace organic acids to prepare effective ligands. Therefore, several experiments using catechol and salicyl alcohol instead of carboxylic acids are shown.

In Table 11, some large acids were found to be ineffective in dissolving titanium dioxide until a small amount of a smaller acid was also added. For example, in Inventive Run 11.56, catechol was ineffective until combined with a small amount of oxalic acid. Similarly, salicylic acid, which was ineffective alone, dissolved Ti when one equivalent of oxalic acid was also added, and produced a high HLMI (Inventive Run 11.54). Similar results occurred with salicyl alcohol in Inventive Runs 11.52 and 11.53, phenylmalonic acid in Run 11.51, diglycolic acid in Run 11.49, iminodiacetic acid in Run 11.48, and methylmalonic acid in Run 11.46.

The target titanium level is 3.5 wt% Ti. This is considered 1 equivalent of Ti. Attempt to dissolve 1 equivalent of titanium dioxide with the stated number of equivalents of carboxylic acid and with the stated number of equivalents of H2O2 and/or base,

After impregnation of the Ti solution onto the silica, the resulting mixture was dried in a vacuum oven at 100°C overnight, and then a portion of the catalyst was calcined at 650°C in dry air for 3 hours. DMAE = dimethylaminoethanol, DMF = dimethylformamide

The target titanium level is 3.5 wt% Ti. This is considered 1 equivalent of Ti. Attempt to dissolve 1 equivalent of titanium dioxide with the stated number of equivalents of carboxylic acid and with the stated number of equivalents of H2O2 and/or base,

After impregnation of the Ti solution onto the silica, the resulting mixture was dried in a vacuum oven at 100°C overnight, and then a portion of the catalyst was calcined at 650°C in dry air for 3 hours. DMAE = dimethylaminoethanol, DMF = dimethylformamide

Additional Disclosures - Part I

The following enumerated aspects of the disclosure are provided as non-limiting examples.

The first aspect is a method comprising a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4; c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:4, and the pH of the solubilized titanium mixture is less than about 5.5; and d) contacting a chromium-silica support containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of about 30 minutes to about 6 hours.

The second aspect is a method as described in the first aspect, which also includes e) calcining the precatalyst to form a catalyst by heating the precatalyst to a temperature in the range of about 400°C to about 1000°C and maintaining the temperature of the precatalyst in the range of about 400°C to about 1000°C for a period of about 1 minute to about 24 hours.

The third aspect is a method as described in any one of the first two aspects, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is about 1:2, and the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the dissolved titanium mixture is about 1:2.

A fourth aspect is the method of any one of the first three aspects, wherein the pH of the solubilized titanium mixture is in the range of about 3.5 to about 4.5.

The fifth aspect is the method according to any one of the previous four aspects, wherein (c) comprises neutralizing the acidic titanium mixture, and wherein the neutralization is partial neutralization or complete neutralization.

The sixth aspect is a method as described in any one of the first five aspects, wherein the nitrogen-containing compound has structure 1, structure 2, structure 3, structure 4, structure 5 or structure 6: wherein R ¹ , R ² , R ³ , R ⁹ , R ¹⁰ and R ¹¹ are each independently hydrogen, a C ₁ to C ₁₂ organic group or a C ₆ to C ₁₂ aromatic group; R ⁴ is a C ₁ to C ₁₂ organic group or a C ₆ to C ₁₂ aromatic group; R ⁵ and R ⁶ are each independently hydrogen, a C ₁ to C ₆ organic group or a C ₆ to C ₁₂ aromatic group; R ⁷ and R ⁸ are each independently hydrogen or CH ₃ ; R ¹² is a branched C ₁ to C ₆ alkyl group, a cyclic C ₁ to C ₆ alkyl group or a linear C ₁ to C ₆ alkyl group; x is an integer from 1 to 4, y is an integer from 1 to 12, and Z is oxygen or sulfur.

NR ¹ R ² R ³ N(R ⁴ ) _x H _(4-x) OH NR ⁵ R ⁶ (CR ⁷ R ⁸ ) _y OH

Structure 1 Structure 2 Structure 3

NR ⁹ R ¹⁰ OH Z＝C(N(R ¹¹ ) ₂ ) ₂ N(R ¹² OH) ₃

Structure 4 Structure 5 Structure 6

The seventh aspect is a method as described in any one of the previous six aspects, wherein the nitrogen-containing compound comprises an alkanolamine, an amine, an ammonium hydroxide, a hydroxylamine, urea, or a combination thereof.

The eighth aspect is a method as described in any one of the first seven aspects, wherein the nitrogen-containing compound includes acetamide, ammonia, ammonium hydroxide, tert-butylamine, creatine, N,N'-dibutylurea, diethanolamine, diisopropanolamine, dimethylaminoethanol, dimethylcarbamate, dimethylformamide, dimethylglycine, dimethylisopropanolamine, N,N'-dimethylurea, ethanolamine, ethylene glycolamine, hexylamine, hydroxylamine, imidazole, isopropanolamine, N-methylaniline, methyldiethanolamine, methylformamide, pyrazole, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanolamine, triisopropanolamine, trimethylamine, urea, or a combination thereof.

The ninth aspect is the method according to any one of the previous eight aspects, wherein the carboxylic acid comprises a _C1 to _C15 monocarboxylic acid, a _C2 to _C15 dicarboxylic acid, a _C3 to _C15 tricarboxylic acid, a _C1 to _C15 α-hydroxycarboxylic acid, or a combination thereof.

The tenth aspect is the method according to any one of the previous nine aspects, wherein the carboxylic acid comprises acetic acid, citric acid, glycolic acid, oxalic acid, phosphonoacetic acid, or a combination thereof.

The eleventh aspect is a method as described in any one of the previous ten aspects, wherein the titanium-containing compound comprises titanium hydroxide, titanic acid, titanyl sulfate, titanium (IV) alkoxide, titanyl acetylacetonate, titanium (IV) halide, or a combination thereof.

A twelfth aspect is a method as in any one of the previous eleven aspects, wherein the titanium-containing compound comprises titanium (IV) isopropoxide.

The thirteenth aspect is a method as described in any one of the previous twelve aspects, wherein (d) further comprises spray drying the solubilized titanium mixture onto the chromium-silica support.

A fourteenth aspect is a method as in any one of the previous thirteen aspects, wherein the chromium-silica support is characterized by having a surface area of about 100 m ² /g to about 1000 m ² /g and a pore volume of about 1.0 cm ³ /g to about 2.5 cm ³ /g.

The fifteenth aspect is a method as described in any one of the previous fourteen aspects, wherein the amount of chromium present in the catalyst is in the range of about 0.01 wt% to about 10 wt% based on the total weight of the catalyst, and the amount of titanium present in the catalyst is in the range of about 0.01 wt% to about 10 wt% based on the total weight of the catalyst.

The sixteenth aspect is a method as described in any one of the previous fifteen aspects, wherein the solvent comprises an aqueous solvent, an alcohol, an organic solvent, or a combination thereof.

The seventeenth aspect is a method for forming an ethylene polymer, comprising contacting the catalyst formed by the method described in the second aspect with an ethylene monomer under conditions suitable for forming the ethylene polymer, and recovering the ethylene polymer.

The eighteenth aspect is the method of the seventeenth aspect, wherein the ethylene polymer has a high load melt index (HLMI) that is about 1.5 to about 15 times greater than the HLMI of an ethylene polymer made with an otherwise similar catalyst produced in the absence of a nitrogen-containing compound.

The nineteenth aspect is a method comprising a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4; c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:4, and the dissolved titanium mixture The method comprises the steps of: providing a titanium oxide carrier having a pH in the range of about 3.5 to about 4.5; d) contacting a silica carrier comprising about 0.1 wt % to about 20 wt % water and the dissolved titanium mixture to form a titanated carrier, and drying the titanated carrier by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours to form a dried titanated carrier; and e) contacting a chromium-containing compound and at least one material selected from the group consisting of the silica carrier, the titanated carrier and the dried titanated carrier to form a precatalyst.

The twentieth aspect is a method as described in the nineteenth aspect, and the method also includes: f) calcining the precatalyst to form a catalyst by heating to a temperature in the range of about 400°C to about 1000°C and maintaining the temperature in the range of about 400°C to about 1000°C for a period of about 1 minute to about 24 hours.

A twenty-first aspect is a method according to aspect nineteen, wherein (c) comprises neutralizing the acidic titanium mixture, and wherein the neutralization is partial neutralization or complete neutralization.

The twenty-second aspect is a method comprising: a) contacting a titanium-containing compound and a nitrogen-containing compound to form an alkaline mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the alkaline mixture is about 1:1 to about 1:4; b) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is about 1:1 to about 100:1; c) contacting the alkaline mixture and the acidic mixture to form a dissolved titanium mixture, wherein the titanium-containing compound in the dissolved titanium mixture The equivalent molar ratio of the titanium to carboxylic acid is about 1:1 to about 1:4, and the pH of the solubilized titanium mixture is in the range of about 3.5 to about 4.5; and d) contacting a chromium-silica carrier containing about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours to form a procatalyst.

The twenty-third aspect is a method as described in the twenty-second aspect, and the method also includes: e) calcining the precatalyst to form a catalyst by heating the precatalyst to a temperature in the range of about 400°C to about 1000°C and maintaining the temperature of the precatalyst in the range of about 400°C to about 1000°C for a period of about 1 minute to about 24 hours.

The twenty-fourth aspect is a method comprising: a) contacting a titanium-containing compound and a nitrogen-containing compound to form an alkaline mixture, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound in the alkaline mixture is about 1:1 to about 1:4; b) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is about 1:1 to about 100:1; c) contacting the alkaline mixture and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is about 1:1 to about 1:4, and the dissolved titanium mixture The method comprises the steps of: providing a titanium oxide carrier having a pH in the range of about 3.5 to about 4.5; d) contacting a silica carrier comprising about 0.1 wt % to about 20 wt % water and the dissolved titanium mixture to form a titanated carrier, and drying the titanated carrier by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours to form a dried titanated carrier; and e) contacting a chromium-containing compound and at least one material selected from the group consisting of the silica carrier, the titanated carrier and the dried titanated carrier to form a precatalyst.

The twenty-fifth aspect is a method as described in the twenty-fourth aspect, and the method also includes: f) calcining the precatalyst to form a catalyst by heating the precatalyst to a temperature in the range of about 400°C to about 1000°C and maintaining the temperature of the precatalyst in the range of about 400°C to about 1000°C for a period of about 1 minute to about 24 hours.

The twenty-sixth aspect is a procatalyst composition, which comprises: a) a silica carrier comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica carrier; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a nitrogen-containing compound having a molecular formula containing at least one nitrogen atom, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

The twenty-seventh aspect is a procatalyst composition as described in the twenty-sixth aspect, wherein the carboxylic acid comprises a _C1 to _C15 monocarboxylic acid, a _C2 to _C15 dicarboxylic acid, a _C3 to _C15 tricarboxylic acid, a _C1 to _C15 α-hydroxycarboxylic acid, or a combination thereof.

The twenty-eighth aspect is a procatalyst composition as described in any one of the twenty-sixth or twenty-seventh aspects, wherein the carboxylic acid comprises acetic acid, citric acid, glycolic acid, oxalic acid, phosphonoacetic acid, or a combination thereof.

The twenty-ninth aspect is a procatalyst composition as described in any one of aspects twenty-six to twenty-eight, wherein the nitrogen-containing compound comprises an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, aniline, hydroxylamine, urea, or a combination thereof.

The 30th aspect is a procatalyst composition as described in any one of aspects 26 to 29, wherein the nitrogen-containing compound includes acetamide, acrylamide, allylamine, ammonia, ammonium hydroxide, butylamine, tert-butylamine, N,N'-dibutylurea, creatine, creatinine, diethanolamine, diethylhydroxylamine, diisopropanolamine, dimethylaminoethanol, dimethylcarbamate, dimethylformamide, dimethylglycine, dimethylisopropanolamine, N,N'-dimethylurea, Ethanolamine, ethylamine, ethylene glycolamine, hexylamine, hydroxylamine, imidazole, isopropanolamine, methacrylamide, methylamine, N-methylaniline, N-methyl-2-propanolamine, methyldiethanolamine, methylformamide, propylamine, 2-propanolamine, pyrazole, pyrrolidine, pyrrolidone, succinimide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanolamine, triisopropanolamine, trimethylamine, urea, 1,8-diazabicyclo[5.4.0]undec-7-ene, or a combination thereof.

The thirty-first aspect is a procatalyst composition as described in any one of aspects twenty-six to thirtieth, wherein the silica support further comprises alumina.

A thirty-second aspect is a procatalyst composition as described in any one of aspects twenty-six to thirty-first, wherein the silica support is characterized by having a surface area of about 100 to about 1000 ^{m 2 /} g and a pore volume of about 1.0 to about ^{2.5 cm 3 /} g.

The thirty-third aspect is a procatalyst composition as described in any one of aspects twenty-six to thirty-second, wherein the silica support comprises a hydrated silica support.

A thirty-fourth aspect is the procatalyst composition of any one of aspects twenty-six to thirty-third, wherein the silica support comprises about 1 wt% to about 20 wt% water based on the total weight of the silica support.

The thirty-fifth aspect is a procatalyst composition, which comprises: a) a silica carrier comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica carrier; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein: i) the amount of titanium is in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) the equivalent molar ratio of titanium to carboxylate is in the range of about 1:1 to about 1:10; and iii) the equivalent molar ratio of titanium to protonated nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

The thirty-sixth aspect is a procatalyst composition as described in the thirty-fifth aspect, wherein the protonated nitrogen-containing compound comprises a protonated alkanolamine, a protonated amide, a protonated amine, a protonated alkylamine, a protonated ammonium hydroxide, a protonated aniline, a protonated hydroxylamine, a protonated urea, or a combination thereof.

The thirty-seventh aspect is a procatalyst composition as described in the thirty-fifth aspect, wherein the protonated nitrogen-containing compound includes protonated acetamide, protonated acrylamide, protonated allylamine, ammonium, protonated ammonium hydroxide, protonated butylamine, protonated tert-butylamine, protonated N,N'-dibutylurea, protonated creatine, protonated creatinine, protonated diethanolamine, protonated diethylhydroxylamine, protonated diisopropanolamine, protonated dimethylaminoethanol, protonated dimethylcarbamate, protonated dimethylformamide, protonated dimethylglycine, protonated dimethylisopropanolamine, protonated N,N'-dimethylurea, protonated ethanolamine, protonated ethylamine, protonated protonated ethylene glycol amine, protonated hexylamine, protonated hydroxylamine, protonated imidazole, protonated isopropanolamine, protonated methacrylamide, protonated methylamine, protonated N-methylaniline, protonated N-methyl-2-propanolamine, protonated methyldiethanolamine, protonated methylformamide, protonated propylamine, protonated 2-propanolamine, protonated pyrazole, protonated pyrrolidine, protonated pyrrolidone, protonated succinimide, protonated tetraethylammonium hydroxide, protonated tetramethylammonium hydroxide, protonated triethanolamine, protonated triisopropanolamine, protonated trimethylamine, protonated urea, protonated 1,8-diazabicyclo[5.4.0]undec-7-ene, or a combination thereof.

The thirty-eighth aspect is a procatalyst composition as described in any one of aspects thirty-fifth to thirty-seventh, wherein the carboxylate comprises a _C1 to _C15 monocarboxylate, a _C2 to _C15 dicarboxylate, a _C3 to _C15 tricarboxylate, a _C1 to _C15 α-hydroxycarboxylate, or a combination thereof.

The thirty-ninth aspect is a procatalyst composition as described in any one of aspects thirty-fifth to thirty-eighth, wherein the carboxylate comprises acetate, citrate, glycolate, oxalate, phosphonoacetate, or a combination thereof.

The fortieth aspect is a procatalyst composition as described in any one of the thirty-fifth to thirty-ninth aspects, wherein the silica support further comprises alumina.

The forty-first aspect is a procatalyst composition as described in any one of the thirty-fifth to fortieth aspects, wherein the silica support is characterized by having a surface area of about 100 m ² /g to about 1000 m ² /g and a pore volume of about 1.0 cm ³ /g to about 2.5 cm ³ /g.

The forty-second aspect is a procatalyst composition as described in any one of aspects thirty-fifth to forty-first, wherein the silica support comprises a hydrated silica support.

The forty-third aspect is a procatalyst composition as described in any one of aspects thirty-fifth to forty-second, wherein the silica support comprises about 1 wt% to about 20 wt% water based on the total weight of the silica support.

The forty-fourth aspect is a procatalyst composition, which comprises: a) a silica carrier comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica carrier; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt% to about 0.1 wt% based on the amount of silica; d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a nitrogen-containing compound having a molecular formula containing at least one nitrogen atom, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

The forty-fifth aspect is a procatalyst composition, the procatalyst composition being prepared by a method comprising: a) contacting a solvent and a carboxylic acid to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form an acidic titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the acidic titanium mixture is from about 1:1 to about 1:4; c) contacting a nitrogen-containing compound and the acidic titanium mixture to form a dissolved titanium mixture, wherein the dissolved The titanium mixture has an equivalent molar ratio of titanium compound to nitrogen compound of about 1:1 to about 1:4, and the pH of the dissolved titanium mixture is less than about 5.5; and d) contacting a chromium-silica carrier containing about 0.1 wt % to about 20 wt % water with the dissolved titanium mixture to form an addition product, and drying the addition product to form the procatalyst by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours.

Additional Disclosures - Part II

The following enumerated aspects of the disclosure are provided as non-limiting examples.

The first aspect is a method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

The second aspect is a method as described in the first aspect, wherein the peroxyl compound comprises hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropylbenzene peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, phthalyl peroxide, or a combination thereof.

The third aspect is the method as described in any one of the first to second aspects, wherein the carboxylic acid comprises a _C1 to _C15 monocarboxylic acid, a _C2 to _C15 dicarboxylic acid, a _C3 to _C15 tricarboxylic acid, a _C1 to _C15 α-hydroxycarboxylic acid, or a combination thereof.

The fourth aspect is a method as described in any one of the first to third aspects, wherein the carboxylic acid comprises acetic acid, citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, gluconic acid, mandelic acid, 2,4-hydroxybenzoic acid, 2,6-pyridinedicarboxylic acid, nitrotriacetic acid, α-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

The fifth aspect is a method comprising a) contacting a solvent, a carboxylic acid, a nitrogen-containing compound, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

The sixth aspect is the method according to the fifth aspect, wherein the carboxylic acid comprises a _C1 to _C15 monocarboxylic acid, a _C1 to _C15 dicarboxylic acid, a _C2 to _C15 tricarboxylic acid, a _C1 to _C15 α-hydroxycarboxylic acid, or a combination thereof.

The seventh aspect is a method as described in any one of the fifth to sixth aspects, wherein the carboxylic acid comprises acetic acid, citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, gluconic acid, mandelic acid, 2,4-hydroxybenzoic acid, 2,6-pyridinedicarboxylic acid, nitrotriacetic acid, α-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

The eighth aspect is the method of any one of the fifth to seventh aspects, wherein the nitrogen-containing compound comprises an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, aniline, hydroxylamine, urea, or a combination thereof.

The ninth aspect is a method as described in any one of the fifth to eighth aspects, wherein the peroxy compound comprises an organic peroxide, a diacyl peroxide, a peroxydicarbonate, a monoperoxycarbonate, a peroxyketal, a peroxyester, a dialkyl peroxide, a hydroperoxide, or a combination thereof.

The tenth aspect is a method as described in any one of the fifth to ninth aspects, wherein the peroxy compound comprises hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropylbenzene peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

The eleventh aspect is a method comprising a) contacting a solvent, at least two carboxylic acids, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1, and wherein the at least two carboxylic acids comprise at least one simple carboxylic acid and at least one complex carboxylic acid; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

The twelfth aspect is the method according to the eleventh aspect, wherein the at least two carboxylic acids include _C1 to _C15 monocarboxylic acids, _C2 to _C15 dicarboxylic acids, _C3 to _C15 tricarboxylic acids, _C1 to _C15 α-hydroxycarboxylic acids, or combinations thereof.

The thirteenth aspect is a method as described in any one of the eleventh to twelfth aspects, wherein the at least two carboxylic acids include citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, gluconic acid, mandelic acid, 2,4-hydroxybenzoic acid, 2,6-pyridinedicarboxylic acid, nitrotriacetic acid, α-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

A fourteenth aspect is a method as described in any one of aspects eleven to thirteen, wherein the peroxy compound comprises an organic peroxide, a diacyl peroxide, a peroxydicarbonate, a monoperoxycarbonate, a peroxyketal, a peroxyester, a dialkyl peroxide, a hydroperoxide, or a combination thereof.

The fifteenth aspect is a method as described in any one of the eleventh to fourteenth aspects, wherein the peroxy compound comprises hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropylbenzene peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

The sixteenth aspect is a method comprising a) contacting a solvent, at least two carboxylic acids and a nitrogen-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is about 1:1 to about 1:4; and c) contacting a chromium-silica carrier containing about 0.1 wt % to about 20 wt % water and the solubilized titanium mixture to form an addition product, and drying the addition product to form a precatalyst by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours.

The seventeenth aspect is a method comprising a) contacting a solvent, at least two carboxylic acids, a nitrogen-containing compound, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4, and the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water with the solubilized titanium mixture to form an addition product, and drying the addition product to form a precatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

The eighteenth aspect is a method comprising a) contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is from about 1:1 to about 1:4, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the dissolved titanium mixture is from about 1:1 to about 1:4; :5; and wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica carrier containing from about 0.1 wt % to about 20 wt % water with the dissolved titanium mixture to form an addition product, and drying the addition product to form a procatalyst by heating to a temperature in the range of from about 50°C to about 150°C and maintaining the temperature in the range of from about 50°C to about 150°C for a period of from about 30 minutes to about 6 hours.

The nineteenth aspect is the method according to the eighteenth aspect, wherein the acidic phenol comprises catechol, salicyl alcohol, salicylic acid, phthalic acid, or any combination thereof.

The twentieth aspect is a method comprising a) contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxide-containing compound to form an acidic mixture, wherein the weight ratio of the solvent to the carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a dissolved titanium mixture, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid in the dissolved titanium mixture is from about 1:1 to about 1:4, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the dissolved titanium mixture is from about 1: to about 1:5; and wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound in the dissolved titanium mixture is from about 1:1 to about 1:4. The equivalent molar ratio of the compounds is from about 1:1 to about 1:20; c) contacting the solubilized titanium mixture with a chromium-containing compound to form a chromium-titanium mixture; d) contacting the chromium-titanium mixture with a silica carrier containing silica to form an addition product, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica carrier; and e) drying the addition product to form a procatalyst by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours.

The twenty-first aspect is a method comprising a) preparing an acidic mixture comprising a solvent and at least two components selected from the group consisting of one or more carboxylic acids, one or more acidic phenols, one or more peroxy compounds, and one or more nitrogen-containing compounds, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting the acidic mixture with a chromium-containing compound, a titanium-containing compound, and a silica support to form an addition product, wherein: (i) the equivalent molar mass of the titanium-containing compound to the carboxylic acid when present in the acidic mixture is The invention relates to a method of preparing a precatalyst comprising: (i) an aqueous solution of titanium-containing compound and an aqueous solution of titanium-containing compound having an equivalent molar ratio of about 1:1 to about 1:4, (ii) an equivalent molar ratio of the titanium-containing compound to the acidic phenol when present in the acidic mixture is about 1: to about 1:5, and (iii) an equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound when present in the acidic mixture is about 1:1 to about 1:20; and c) drying the addition product by heating to a temperature in the range of about 50°C to about 150°C and maintaining the temperature in the range of about 50°C to about 150°C for a period of about 30 minutes to about 6 hours to form a procatalyst.

The twenty-second aspect is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; d) a carboxylic acid, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is in the range of about 1:1 to about 1:20.

The twenty-third aspect is the composition of the twenty-second aspect, further comprising a nitrogen-containing compound, wherein an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

The twenty-fourth aspect is the composition of any one of aspects twenty-second to twenty-third, wherein the carboxylic acid comprises a _C1 to _C15 monocarboxylic acid, a _C2 to _C15 dicarboxylic acid, a _C3 to _C15 tricarboxylic acid, a _C1 to _C15 α-hydroxycarboxylic acid, or a combination thereof.

The twenty-fifth aspect is a composition as described in any one of aspects twenty-second to twenty-fourth, wherein the carboxylic acid comprises citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, gluconic acid, mandelic acid, 2,4-hydroxybenzoic acid, 2,6-pyridinedicarboxylic acid, nitrotriacetic acid, α-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

The twenty-sixth aspect is the composition of any one of aspects twenty-third to twenty-fifth, wherein the nitrogen-containing compound comprises an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, an aniline, a hydroxylamine, urea, or a combination thereof.

The twenty-seventh aspect is a composition as described in any one of aspects twenty-second to twenty-six, wherein the peroxy compound comprises an organic peroxide, a diacyl peroxide, a peroxydicarbonate, a monoperoxycarbonate, a peroxyketal, a peroxyester, a dialkyl peroxide, a hydroperoxide, or a combination thereof.

The twenty-eighth aspect is a composition as described in any one of aspects twenty-second to twenty-seven, wherein the peroxy compound comprises hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropylbenzene peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

The twenty-ninth aspect is the composition of any one of aspects twenty-second to twenty-eighth, further comprising an acidic phenol.

The thirtieth aspect is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a carboxylate, and a peroxide-containing compound, and wherein the titanium organic salt comprises i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to peroxide-containing compound in the range of about 1:0.5 to about 1:20.

The thirty-first aspect is the composition as described in the thirtieth aspect, wherein the composition further comprises a nitrogen-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:5.

The thirty-second aspect is a composition as described in any one of aspects 30 to 31, wherein the peroxy compound comprises hydrogen peroxide, di-tert-butyl peroxide, benzoyl peroxide, diisopropyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

The thirty-third aspect is a composition as described in any one of the thirtieth to thirty-second aspects, wherein the carboxylate comprises acetate, citrate, gluconate, glycolate, glyoxylate, lactate, malate, malonate, oxalate, phosphonoacetate, tartrate, or a combination thereof.

The thirty-fourth aspect is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt% to about 0.1 wt% based on the amount of silica; d) at least two carboxylic acids, wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid is in the range of about 1:1 to about 1:10; and e) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is in the range of about 1:1 to about 1:10.

The thirty-fifth aspect is a composition as described in the thirty-fourth aspect, wherein the at least two carboxylic acids comprise at least one simple carboxylic acid and at least one complex carboxylic acid.

The thirty-sixth aspect is the composition of aspects thirty-four to thirty-fifth, wherein the peroxyl group-containing compound comprises hydrogen peroxide, tert-butyl peroxide, or a combination thereof.

The thirty-seventh aspect is the composition as described in aspects thirty-fourth to thirty-sixth, further comprising acidic phenol.

The thirty-eighth aspect is the composition of any one of aspects thirty-four to thirty-seven, further comprising a nitrogen-containing compound, wherein an equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound is in the range of about 1:0.5 to about 1:10.

The thirty-ninth aspect is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein the titanium organic salt comprises: i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to protonated nitrogen-containing compound in the range of about 1:0.5 to about 1:10; and d) a peroxide-containing compound, wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound is about 1:1 to about 1:20.

The fortieth aspect is a composition comprising a) a silica support comprising silica, wherein the amount of silica is in the range of about 70 wt% to about 95 wt% based on the total weight of the silica support; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; and c) a titanium organic salt, wherein the titanium organic salt comprises titanium, a protonated nitrogen-containing compound and a carboxylate, and wherein the titanium organic salt comprises i) an amount of titanium in the range of about 0.1 wt% to about 20 wt% based on the amount of silica; ii) an equivalent molar ratio of titanium to carboxylate in the range of about 1:1 to about 1:10; and iii) an equivalent molar ratio of titanium to protonated nitrogen-containing compound in the range of about 1:0.5 to about 1:10; and d) an acidic phenol, wherein the equivalent molar ratio of the titanium-containing compound to the acidic phenol in the acidic titanium mixture is about 1:1 to about 1:5.

The forty-first aspect is a composition comprising a) at least two components selected from the group consisting of one or more carboxylic acids, one or more acidic phenols, one or more peroxide-containing compounds and one or more nitrogen-containing compounds; b) a chromium-containing compound, wherein the amount of chromium is in the range of about 0.1 wt% to about 5 wt% based on the amount of silica; c) a titanium-containing compound, wherein the amount of titanium is in the range of about 0.01 wt% to about 0.1 wt% based on the amount of silica; and (i) wherein the equivalent molar ratio of the titanium-containing compound to the carboxylic acid when present is in the range of about 1:1 to about 1:10; (ii) wherein the equivalent molar ratio of the titanium-containing compound to the peroxide-containing compound when present is in the range of about 1:1 to about 1:10; (iii) wherein the equivalent molar ratio of the titanium-containing compound in the acidic titanium mixture to the acidic phenol when present is about 1:1 to about 1:5; and (iv) wherein the equivalent molar ratio of the titanium-containing compound to the nitrogen-containing compound when present is in the range of about 1:0.5 to about 1:5.

The forty-second aspect is a catalyst prepared according to the method described in the first aspect, wherein the method further comprises heating the precatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-third aspect is a catalyst prepared according to the method described in the fifth aspect, wherein the method further comprises heating the procatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-fourth aspect is a catalyst prepared according to the method described in the eleventh aspect, wherein the method further comprises heating the precatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-fifth aspect is a catalyst prepared by the method according to the sixteenth aspect, wherein the method further comprises heating the procatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-sixth aspect is a catalyst prepared by the method according to the seventeenth aspect, wherein the method further comprises heating the procatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-seventh aspect is a catalyst prepared according to the method described in the eighteenth aspect, wherein the method further comprises heating the precatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-eighth aspect is a catalyst prepared by the method according to the twentieth aspect, wherein the method further comprises heating the procatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

The forty-ninth aspect is a catalyst prepared according to the method described in the twenty-first aspect, wherein the method further comprises heating the precatalyst to a temperature in the range of about 400°C to about 1000°C in the presence of air to form an olefin polymerization catalyst.

Unless specifically indicated otherwise, the terms "a(n)" and "the(n)" are intended to include plural alternatives, e.g., at least one(n). In this document, although methods and processes are described as "comprising" various components or steps, the methods and processes may also "consist essentially of" or "consist of" the various components or steps. Specific features of the disclosed subject matter may be disclosed as follows: Feature X may be A, B, or C. It is also contemplated that for each feature, the statement may also be recited as a list of alternatives, such that the statement "Feature X is A, alternatively, B, or alternatively, C" is also an aspect of the disclosure, whether or not the statement is explicitly recited.

Although various aspects of the present disclosure have been shown and described, they can be modified by those skilled in the art without departing from the spirit and teachings of the present disclosure. The aspects of the present disclosure described herein are exemplary only and are not intended to be limiting. Many changes and modifications of the present disclosure are possible and are within the scope of the present disclosure. When a numerical range or limit is explicitly stated, such an explicit range or limit should be understood to include iterative ranges or limits of similar magnitudes falling within the explicitly stated range or limit (e.g., "about 1 to about 10" includes 2, 3, 4, etc.; "greater than 0.10" includes 0.11, 0.12, 0.13, etc.). The use of the term "optionally" with respect to any element of a claim means that the subject element is required, or alternatively, not required. Both alternatives are intended to be within the scope of the claim. The use of broad terms such as "comprising", "including", "having", etc. should be understood to provide support for narrow terms such as "consisting of", "consisting essentially of", "substantially comprising", etc.

Therefore, the scope of protection is not limited to the description set forth above, but is only limited to the subsequent claims, the scope of which includes all equivalents of the subject matter of the claims. Each claim is incorporated into the specification as an aspect of the present disclosure. Therefore, the claims are further descriptions and are supplementary to aspects of the present disclosure. The discussion of a reference in this disclosure is not an admission that it is prior art to the present disclosure, especially any reference that may have a publication date after the priority date of this application. The current disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference to the extent that they provide exemplary, procedural or other details that supplement those set forth herein.

All publications, patent applications, and patents mentioned herein are incorporated herein by reference in their entirety. In the event of a conflict, the present specification, including definitions, will prevail. With respect to all ranges disclosed herein, such ranges are intended to include any combination of the upper and lower limits mentioned, even if a particular combination is not specifically listed.

Claims (20)

1. A method, the method comprising:

a) Contacting a solvent, a carboxylic acid, and a peroxy-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from 1:1 to 100:1;

b) Contacting a titanium-containing compound with the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from 1:1 to 1:4, and the equivalent molar ratio of titanium-containing compound to peroxy-containing compound in the solubilized titanium mixture is from 1:3 to 1:10; and

c) Contacting a chromium-silica support comprising 0.1wt% to 20wt% water and the solubilized titanium mixture to form an addition product, and drying the addition product by heating to a temperature in the range of 50 ℃ to 150 ℃ and maintaining the temperature in the range of 50 ℃ to 150 ℃ for a period of 30 minutes to 6 hours to form a procatalyst.

2. The method of claim 1, wherein the peroxy-containing compound comprises hydrogen peroxide, di-t-butyl peroxide, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

3. The method of claim 1, wherein the carboxylic acid comprises C ₁ To C ₁₅ Monocarboxylic acid, C ₂ To C ₁₅ Dicarboxylic acids, C ₃ To C ₁₅ Tricarboxylic acid, C ₁ To C ₁₅ Alpha-hydroxycarboxylic acids, or combinations thereof.

4. The method of claim 1, wherein the carboxylic acid comprises acetic acid, citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, mandelic acid, 2, 4-hydroxybenzoic acid, 2, 6-pyridinedicarboxylic acid, nitrotriacetic acid, alpha-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

5. A method, the method comprising:

a) Contacting a solvent, a carboxylic acid, a nitrogen-containing compound, and a peroxy-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from 1:1 to 100:1, and wherein the equivalent molar ratio of nitrogen-containing compound to carboxylic acid is in the range of from 0.1:1 to 5:1;

b) Contacting a titanium-containing compound with the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from 1:1 to 1:4, and the equivalent molar ratio of titanium-containing compound to peroxy-containing compound in the solubilized titanium mixture is from 1:3 to 1:10; and

c) Contacting a chromium-silica support comprising 0.1wt% to 20wt% water and the solubilized titanium mixture to form an addition product, and drying the addition product by heating to a temperature in the range of 50 ℃ to 150 ℃ and maintaining the temperature in the range of 50 ℃ to 150 ℃ for a period of 30 minutes to 6 hours to form a procatalyst.

6. The method of claim 5, wherein the carboxylic acid comprises C ₁ To C ₁₅ Monocarboxylic acid, C ₂ To C ₁₅ Dicarboxylic acids, C ₃ To C ₁₅ Tricarboxylic acid, C ₁ To C ₁₅ Alpha-hydroxycarboxylic acids, or combinations thereof.

7. The method of claim 5, wherein the carboxylic acid comprises acetic acid, citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, mandelic acid, 2, 4-hydroxybenzoic acid, 2, 6-pyridinedicarboxylic acid, nitrotriacetic acid, alpha-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, or a combination thereof.

8. The method of claim 5, wherein the nitrogen-containing compound comprises one or more amines.

9. The method of claim 5, wherein the nitrogen-containing compound comprises an alkanolamine, an amide, an alkylamine, an ammonium hydroxide, an aniline, a hydroxylamine, urea, or a combination thereof.

10. The method of claim 5, wherein the peroxy-containing compound comprises one or more organic peroxides.

11. The method of claim 5, wherein the peroxy-containing compound comprises a diacyl peroxide, peroxydicarbonate, monoperoxycarbonate, peroxyketal, peroxyester, dialkyl peroxide, hydroperoxide, or a combination thereof.

12. The method of claim 5, wherein the peroxy-containing compound comprises hydrogen peroxide, di-t-butyl peroxide, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

13. A method, the method comprising:

a) Contacting a solvent, at least two carboxylic acids, and a peroxy-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from 1:1 to 100:1, and wherein the at least two carboxylic acids comprise at least one simple carboxylic acid and at least one complex carboxylic acid; wherein the at least one complex carboxylic acid comprises at least one ring structure;

b) Contacting a titanium-containing compound with the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from 1:1 to 1:4, and the equivalent molar ratio of titanium-containing compound to peroxy-containing compound in the solubilized titanium mixture is from 1:3 to 1:10; and

c) Contacting a chromium-silica support comprising 0.1wt% to 20wt% water and the solubilized titanium mixture to form an addition product, and drying the addition product by heating to a temperature in the range of 50 ℃ to 150 ℃ and maintaining the temperature in the range of 50 ℃ to 150 ℃ for a period of 30 minutes to 6 hours to form a procatalyst.

14. The method of claim 13, wherein the at least two carboxylic acids comprise C ₁ To C ₁₅ Monocarboxylic acid, C ₂ To C ₁₅ Dicarboxylic acids, C ₃ To C ₁₅ Tricarboxylic acid, C ₁ To C ₁₅ Alpha-hydroxycarboxylic acids, or combinations thereof.

15. The method of claim 13, wherein the at least two carboxylic acids comprise citric acid, gluconic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, malonic acid, oxalic acid, phosphonoacetic acid, tartaric acid, glyceric acid, mandelic acid, 2, 4-hydroxybenzoic acid, 2, 6-pyridinedicarboxylic acid, nitrotriacetic acid, alpha-hydroxyisobutyric acid, methylmalonic acid, phenylmalonic acid, digluconic acid, iminodiacetic acid, hydroxymethyl-2-butyric acid, salicylic acid, phenylmalonic acid, diglycolic acid, or a combination thereof.

16. The method of claim 13, wherein the peroxy-containing compound comprises one or more organic peroxides.

17. The method of claim 13, wherein the peroxy-containing compound comprises a diacyl peroxide, peroxydicarbonate, monoperoxycarbonate, peroxyketal, peroxyester, dialkyl peroxide, hydroperoxide, or a combination thereof.

18. The method of claim 13, wherein the peroxy-containing compound comprises hydrogen peroxide, di-t-butyl peroxide, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, phthaloyl peroxide, or a combination thereof.

19. A method, the method comprising:

a) Contacting a solvent, a carboxylic acid, an acidic phenol, and a peroxy-containing compound to form an acidic mixture, wherein the weight ratio of solvent to carboxylic acid in the acidic mixture is from 1:1 to 100:1;

b) Contacting a titanium-containing compound with the acidic mixture to form a solubilized titanium mixture, wherein the equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from 1:1 to 1:4, wherein the equivalent molar ratio of titanium-containing compound to acidic phenol in the solubilized titanium mixture is from 1:1 to 1:5; and wherein the equivalent molar ratio of titanium-containing compound to peroxy-containing compound in the solubilized titanium mixture is from 1:3 to 1:10; and

c) Contacting a chromium-silica support comprising 0.1wt% to 20wt% water and the solubilized titanium mixture to form an addition product, and drying the addition product by heating to a temperature in the range of 50 ℃ to 150 ℃ and maintaining the temperature in the range of 50 ℃ to 150 ℃ for a period of 30 minutes to 6 hours to form a procatalyst.

20. The method of claim 19, wherein the acidic phenol comprises catechol, salicyl alcohol, salicylic acid, or any combination thereof.