CN104927615A

CN104927615A - Preparation method for TDI trimer matt curing agent low in free monomer content

Info

Publication number: CN104927615A
Application number: CN201510337036.3A
Authority: CN
Inventors: 许钧强; 康伦国; 姚东生; 阳京辉; 邓安; 王会池
Original assignee: Shaoguan Union Chemical Co Ltd; Union Foshan Chemical Co Ltd
Current assignee: Shandong Xinkaiyuan Technology Innovation Development Co ltd; Shandong Xinkaiyuan Venture Capital Management Co ltd
Priority date: 2015-06-17
Filing date: 2015-06-17
Publication date: 2015-09-23
Anticipated expiration: 2035-06-17
Also published as: CN104927615B

Abstract

The invention relates to a preparation method for a TDI trimer matt curing agent low in free monomer content. According to the formula, the curing agent comprises 2,4-toluene diisocyanate, polyether polyol, long-chain alcohol, a catalyst A, n-butanol, a catalyst B, polymerization inhibitor, antioxidant and a solvent. According to the prepared TDI trimer matt curing agent low in free monomer content, the solid content is 50+/-2%, the NCO value is 8.0+/-0.3%, the viscosity (Tu-4 cup) is 15-25 s, the free TDI is smaller than or equal to 0.5%, the toluene tolerance is larger than or equal to 1, and the curing agent does not contain arene and is characterized by being environmentally friendly, good in scratch resistance, good in transparency and the like. Polyurethane paint manufactured through hydroxyl group components is characterized by being high in hardness, high in transparency, good in film scratch resistance, good in leveling property, high in fullness, high in solubility and the like. The environment-friendly curing agent is used for various two-component polyester paint, polyurethane paint, decorative paint, floor paint, priming paint and the like of woodware, metal, plastics and the like.

Description

A kind of preparation method of TDI tripolymer dumb light solidifying agent of low free monomer content

Technical field

The present invention relates to a kind of preparation method of polyurethane curing agent, refer more particularly to a kind of TDI tripolymer dumb light solidifying agent of low free monomer content.

Background technology

Bicomponent polyurethane coating is generally made up of isocyanate prepolymer and hydroxy-containing resin two portions, be commonly referred to curing agent component and host component, difference according to hydroxy-containing component can be divided into acroleic acid polyurethane, alcohol acid and polyurethane, polyester-polyurethane, polyether-polyurethane, the kinds such as epoxy polyurethane, generally all there is film-forming temperature low, strong adhesion, hardness is large, good and the chemicals-resistant of wear resistance, the high-performances such as good weatherability, a kind of coating most widely used at present, be mainly used in original factory of vehicle paint, plastic paint, wood lacquer, industrial paint, protective system floor paint, electronic paint, fabric leather coating, the aspects such as printing-ink industry.In China, polyurethane coating accounts for the market share of about 75% in woodwork coating, accounts for the market share of about 40% in car refinishing paint, and at other field as the application of protective system, plastic paint etc. is also more and more wider, the market share is about 10%.

TDI solidifying agent conventional on the market at present has TDI tripolymer, TDI-TMP affixture, and the main raw material producing solidifying agent is exactly tolylene diisocyanate (being called for short TDI), TDI is a kind of volatilizable toxic substance, it can make protein denaturation with the proteins react of human body, therefore to the maximum harm of human body.The steam of TDI has strong lacrimation, stimulates respiratory system after suction, and cause dry cough, laryngalgia, headache, bronchitis and asthma, serious meeting causes death.In order to avoid isocyanate-monomer is to the harm of human body, each state all works out the limitation of polyurethane products free monomers; The European Community specifies, the container outer wall containing chemical such as TDI, HDI, IPDI, HMDI must put up mark: vulcabond free monomer massfraction person below 0.5%, and outer wall is indicated " containing isocyanic ester ", is environmentfriendly products; Free monomer content, 0.5% ~ 2.0%, indicates " being harmful to " warning sign and " containing isocyanic ester "; Free monomer content is person more than 2%, except indicating " containing isocyanic ester ", also must indicate " poisonous " and having human skeleton bones of the dead mark.

Country has formulated compulsory standard in coating environmental protection in recent years, volatile organic compounds in polyurethane paint (VOC) content≤670g/L is defined in standard GB/T 18581-2009 " in indoor decorating and refurnishing materials solvent wood coatings limits of harmful substances ", benzene content≤0.3%, toluene, dimethylbenzene, ethylene total content≤30%, free TDI, | HDI content summation≤0.4%.

Reduce the direction that polyurethane curing agent free TDI monomer content becomes the tackling key problem of domestic and international solidifying agent industry emphasis, from know-why, the technological approaches reducing free TDI can be divided into chemical process and physical method, comprising: direct synthesis technique, solvent extration, high vacuum film evaporation method, molecular distillation method and chemical catalysis method for refining etc.What current large-scale industrialization was produced is mostly offshore company, and as Bayer company, Rhodia company, Nippon Polyurethane Industry Co., Ltd. etc., minimizing technology is high vacuum film evaporation method.But high vacuum film evaporation method, invest excessive, process control needs is high, domesticly at present technology and equipment problem is removed to this method never solve well, free isocyanate monomer content severe overweight in the domestic TDI solidifying agent of major part, the content of TDI is difficult to accomplish within 0.5%, mostly about 1%.

The method of the free toluene diisocyanate in a kind of film evaporation method process solidifying agent affixture is all disclosed in Chinese patent literature CN1793194A, CN101717571A, its Bian mode of multiple-effect thin film evaporation, at high temperature evaporate free tolylene diisocyanate by the mode of vacuum, the content of free TDI is between 0.15 ~ 0.5%.

Chinese patent literature CN 101456940A discloses a kind of synthetic method of dissolvant type polyurethane curing agent of low free toluene diisocyanate content, carry out in two stages: the first stage, tolylene diisocyanate and polyvalent alcohol are reacted in a solvent, the degree of reacting and carrying out is monitored by the content of sampling detection NCO in the mixture of reaction in reaction process, when the stable content of NCO, be the reaction end of first stage; Subordinate phase, acetylacetic ester is added in the mixture of above-mentioned reaction, continue reaction, the degree of reacting and carrying out is monitored by the content of sampling detection NCO in the mixture of reaction in reaction process, after the content of NCO is stablized again, being the reaction end of subordinate phase, is also the terminal of total overall reaction, and the reaction of subordinate phase is carried out at low temperatures; Product is TDI-TMP affixture, and 50% admittedly containing free TDI content < 0.5%.This method utilize acetylacetic ester at low temperatures with the difference of the reactive behavior of the NCO group on tolylene diisocyanate different positions, by low-temp reaction, reach the object reducing free toluene diisocyanate; Feasible in theory, but TDI-80/20 has 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate two kinds of isomer, NCO reactive behavior on 4 is high, can react with acetylacetic ester at low temperatures, but the NCO on 2,6 reacts with acetylacetic ester due to sterically hindered being difficult to, although 2,4-toluene diisocyanate monomer take part in reaction, but 2,6-toluene diisocyanate monomer also exists, be therefore difficult to accomplish the 50% TDI-TMP solidifying agent Free TDI < 0.5% admittedly contained; Solidifying agent is long in period of storage in addition, can induce reaction under variation of ambient temperature, and nco value reduces, viscosity increases, easy gel.

Chinese patent literature CN 100439414C discloses a kind of preparation method of low-free TDI trimer curing agent, and it comprises: TDI, solvent S, catalyst A are dropped in reactor, add oxidation inhibitor and long-chain alcohol, heating and thermal insulation, detect nco value; When nco value reaches 20 ~ 40%, add Phase transfer solvent X and catalyst B, until when nco value reaches 10 ~ 15%, add stopper stopped reaction; Supplementing solvent S, underpressure distillation removing Phase transfer solvent X.Wherein solvent S be vinyl acetic monomer, N-BUTYL ACETATE, and composition thereof; Phase transfer solvent X is sherwood oil, methylcarbonate, normal hexane, cyclohexane or its any mixture; Catalyst A, catalyst B are all Lithium Acetate, KOH, NaOH, tributylphosphine, triethylenediamine and any mixture thereof; Obtained product is TDI tripolymer, and 45% admittedly containing free TDI content < 0.5%.This method is the improved technology of solvent extration, unreacted free isocyanate monomer is dissolvable in water hydrocarbon mixture (as sherwood oil, methylcarbonate, normal hexane, hexanaphthene benzene or its mixture), solidifying agent polymkeric substance then can not solution modeling in bottom, then continue to add catalyst reaction at upper strata hydrocarbon mixture solvent, but be difficult to when stirring control its reaction in a still, easy generation superpolymer, even gel; And do not stir lower free isocyanate monomer and be difficult to react completely.And vinyl acetic monomer, N-BUTYL ACETATE boiling point are low, very easily form azeotrope with hydrocarbon mixture, conventional underpressure distillation is difficult to remove hydrocarbon mixture, then constantly add and waste a large amount of vinyl acetic monomers, N-BUTYL ACETATE; And will temperature be improved during underpressure distillation, the time is long, and whether the solidifying agent in still does not just know or solidifying agent under catalyzer, high temperature; Containing ester, free monomer in the solvent distilled in addition, can not use, can not discharge, storage is all a problem, and therefore how recycling design is difficult.Both made method feasible, and also can not eliminate hydrocarbon mixture solvent residual in solidifying agent, finally can affect product performance.

Summary of the invention

The present invention aims to provide a kind of preparation method of TDI tripolymer dumb light solidifying agent of low free monomer content.

It is raw material that the present invention adopts 2,4 toluene diisocyanate to be TDI trimer curing agent, avoids NCO on 2,6-tolylene diisocyanate 2,6 and is difficult to reaction due to sterically hindered and left behind; Conventional TDI trimer curing agent is general all more crisp, and snappiness, glossiness and resistance to marring are all poor, adopts long-chain alcohol can improve solidifying agent to the tolerance of toluene and the snappiness improving film.

TDI trimer catalyst adopts DMP-30, triazine (PC-41), two (dimethylaminoethyl) ether, triethylenediamine, isocaprylic acid potassium, isocaprylic acid zinc, Potassium ethanoate, zinc naphthenate or its mixture.

Later stage is that free TDI is converted into nontoxic material, and the present invention adopts micromolecular oxy-compound propyl carbinol effectively can reduce free TDI monomer content in solidifying agent under the effect of catalyzer; The catalyzer reducing free TDI content is the one of isocaprylic acid potassium, isocaprylic acid zinc, Potassium ethanoate, zinc naphthenate.

Because benzene kind solvent toxicity is large, the present invention adopts the vinyl acetic monomer of low toxicity, N-BUTYL ACETATE, methylcarbonate as the solvent of reaction and letdown solvent dun.

In order to solve technical problem recited above, the present invention takes following technical scheme: the TDI tripolymer dumb light solidifying agent that the present invention relates to a kind of low free monomer content, it is characterized in that: by weight percentage, its formula consists of: 2,4 toluene diisocyanate 48.0 ~ 52.0%, long-chain alcohol 1.5 ~ 4.0%, catalyst A 0.1 ~ 0.3%, propyl carbinol 1.6 ~ 3.0%, catalyst B 0.04 ~ 0.1%, stopper 0.16 ~ 0.30%, oxidation inhibitor 0.2 ~ 0.4%, solvent 40 ~ 50%; Described long-chain alcohol is the combination of one or more of lauryl alcohol, 16 carbon alcohol, octadecanol; Described catalyst A is the composition of a kind of and solvent of a kind of and isocaprylic acid potassium of DMP-30, triazine (PC-41), two (dimethylaminoethyl) ether or triethylenediamine, isocaprylic acid zinc, Potassium ethanoate or zinc naphthenate; Described catalyst B is the combination of one or more of isocaprylic acid potassium, isocaprylic acid zinc, Potassium ethanoate, zinc naphthenate; Described stopper is the one of phosphoric acid, Hypophosporous Acid, 50 or Benzoyl chloride; Described oxidation inhibitor is BHT, BHEB, DBEP, 1331,1010,1098 or the combination of one or more of UV-P; Described solvent is the combination of one or more of vinyl acetic monomer, N-BUTYL ACETATE, methylcarbonate; Described long-chain alcohol, propyl carbinol or solvent are beforehand with processed.

The present invention proposes a kind of preparation method of TDI tripolymer dumb light solidifying agent of low free monomer content, it is characterized in that: comprise the following steps:

1), by weight percentage respectively 2,4 toluene diisocyanate, long-chain alcohol, solvent are put in reactor, logical N ₂protection, is warmed up to 75 ~ 80 DEG C, after insulation 0.5 ~ 1h, cools to 55 DEG C, then adds composite good catalyst A, and control temperature, after 55 ~ 65 DEG C of reaction 4h, starts to detect NCO, detects a nco value afterwards every 0.5h;

2), when the NCO detected is 10 ± 0.5% time, add propyl carbinol and catalyst B, control temperature is at 55 ~ 60 DEG C; When the NCO detected is 8.0 ± 0.3% time, add stopper, oxidation inhibitor and letdown solvent dun, stir 0.5h, cool to 40 DEG C, sampling and measuring color (Fe-Co colorimetric), solid content, viscosity, toluene tolerance, nco value and free TDI value, after reaching requirement, discharging filters and packages.

The TDI tripolymer dumb light solidifying agent of the low free monomer content that the present invention obtains, technical target of the product is: color (Fe-Co)≤1, solid content are 50 ± 2%, nco value is 8.0 ± 0.3%, viscosity (being coated with-4 glasss) 15 ~ 25s, free TDI≤0.5%, toluene tolerance >=1, aromatic free, features such as there is environmental protection, scratch resistance is good, fullness ratio is high, the transparency is good; The polyurethane paint prepared with hydroxy component has high rigidity, high transparent, paint film resistance to marring is good, levelling property is good, the features such as fullness ratio is high, intermiscibility is wide are for environment-friendly type fixed agents such as the various bi-component polyester dumb light such as woodenware, metal, plastics paint, polyurethane matte paint, fancy paint, hard floor paint, priming paint.

Embodiment

Below in conjunction with embodiment, the present invention is further illustrated.

Embodiment 1:

In synthesis reactor, by formulation weight ratio, add lauryl alcohol 25 parts, N-BUTYL ACETATE 462 parts successively, being warmed up to about 108 DEG C has backflow, and backflow 2 ~ 3h dewaters, if occur without the globule in water trap, and cooling down; When cooling to below 40 DEG C, add 2,4 toluene diisocyanate 486 parts, logical N ₂protection, is warmed up to 75 ~ 80 DEG C, after insulation 0.5 ~ 1h, cool to 55 DEG C, add by the composite catalyst A 1.8 parts of DMP-30, isocaprylic acid potassium and N-BUTYL ACETATE, control temperature is after 55 ~ 65 DEG C of reaction 4h, start to detect NCO, detect a nco value every 0.5h afterwards; When the NCO detected is 10 ± 0.5% time, add propyl carbinol 20 parts and isocaprylic acid potassium catalyzer 0.5 part, control temperature is at 55 ~ 60 DEG C; When the NCO detected is 8.0 ± 0.3% time, stop passing into N ₂, add Benzoyl chloride 2.0 parts, oxidation inhibitor BHEB 2.7 parts and add N-BUTYL ACETATE latting drown to 50 ± 2% solid contents, stirring 0.5h, cool to 40 DEG C, filter and package.

Embodiment 2:

In synthesis reactor, by formulation weight ratio, add lauryl alcohol 32 parts, N-BUTYL ACETATE 436 parts successively, being warmed up to about 108 DEG C has backflow, and backflow 2 ~ 3h dewaters, if occur without the globule in water trap, and cooling down; When cooling to below 40 DEG C, add 2,4 toluene diisocyanate 502 parts, logical N ₂protection, is warmed up to 75 ~ 80 DEG C, after insulation 0.5 ~ 1h, cool to 55 DEG C, add by the composite catalyst A 1.8 parts of DMP-30, zinc naphthenate and N-BUTYL ACETATE, control temperature is after 55 ~ 65 DEG C of reaction 4h, start to detect NCO, detect a nco value every 0.5h afterwards; When the NCO detected is 10 ± 0.5% time, add propyl carbinol 22 parts and zinc naphthenate catalyzer 0.6 part, control temperature is at 55 ~ 60 DEG C; When the NCO detected is 8.0 ± 0.3% time, stop passing into N ₂, add phosphoric acid 2.4 parts, antioxidant BHT 3.2 parts and add N-BUTYL ACETATE latting drown to 50 ± 2% solid contents, stirring 0.5h, cool to 40 DEG C, filter and package.

Embodiment 3:

In synthesis reactor, by formulation weight ratio, add lauryl alcohol 20 parts, 16 carbon alcohol 8 parts, N-BUTYL ACETATE 448 parts successively, being warmed up to about 108 DEG C has backflow, and backflow 2 ~ 3h dewaters, if occur without the globule in water trap, and cooling down; When cooling to below 40 DEG C, add 2,4 toluene diisocyanate 496 parts, logical N ₂protection, is warmed up to 75 ~ 80 DEG C, after insulation 0.5 ~ 1h, cool to 55 DEG C, add by the composite catalyst A 1.7 parts of PC-41, isocaprylic acid zinc and N-BUTYL ACETATE, control temperature is after 55 ~ 65 DEG C of reaction 4h, start to detect NCO, detect a nco value every 0.5h afterwards; When the NCO detected is 10 ± 0.5% time, add propyl carbinol 21 parts and isocaprylic acid zinc catalyst 0.5 part, control temperature is at 55 ~ 60 DEG C; When the NCO detected is 8.0 ± 0.3% time, stop passing into N ₂, add Benzoyl chloride 2.0 parts, antioxidant 1010 2.8 parts and add N-BUTYL ACETATE latting drown to 50 ± 2% solid contents, stirring 0.5h, cool to 40 DEG C, filter and package.

According to relevant national standard, detect the technical indicator of the TDI tripolymer dumb light solidifying agent of the low free monomer content that example of the present invention obtains, test result is as shown in table 1.

The TDI tripolymer dumb light solidifying agent technical indicator of table 1 low free monomer content

Although the present invention has been explained in detail and has quoted embodiment as proof, for those of ordinary skill in the art, the various schemes obviously can made according to above-mentioned explanation, amendment and change, within the scope that all should be included in claim.

Claims

1. the TDI tripolymer dumb light solidifying agent of a low free monomer content, it is characterized in that: by weight percentage, its formula consists of: 2,4 toluene diisocyanate 48.0 ~ 52.0%, long-chain alcohol 1.5 ~ 4.0%, catalyst A 0.1 ~ 0.3%, propyl carbinol 1.6 ~ 3.0%, catalyst B 0.04 ~ 0.1%, stopper 0.16 ~ 0.30%, oxidation inhibitor 0.2 ~ 0.4%, solvent 40 ~ 50%; Described polyether glycol is the one of 210 polyethers, 220 polyethers; Described long-chain alcohol is the combination of one or more of lauryl alcohol, 16 carbon alcohol, octadecanol; Described catalyst A is the composition of a kind of and solvent of a kind of and isocaprylic acid potassium of DMP-30, triazine (PC-41), two (dimethylaminoethyl) ether or triethylenediamine, isocaprylic acid zinc, Potassium ethanoate or zinc naphthenate; Described catalyst B is isocaprylic acid potassium, isocaprylic acid zinc, Potassium ethanoate, one or more combination of zinc naphthenate; Described stopper is the one of phosphoric acid, Hypophosporous Acid, 50 or Benzoyl chloride; Described oxidation inhibitor is BHT, BHEB, DBEP, 1331,1010,1098 or the combination of one or more of UV-P; Described solvent is the combination of one or more of vinyl acetic monomer, N-BUTYL ACETATE, methylcarbonate; Described polyether glycol, long-chain alcohol, propyl carbinol or solvent are beforehand with processed.

2. the preparation method of the TDI tripolymer dumb light solidifying agent of a kind of low free monomer content as claimed in claim 1, is characterized in that: described preparation method, comprises the following steps:

1), by weight percentage respectively 2,4 toluene diisocyanate, polyether glycol, long-chain alcohol, solvent are put in reactor, logical N ₂protection, is warmed up to 75 ~ 80 DEG C, after insulation 0.5 ~ 1h, cools to 55 DEG C, then adds composite good catalyst A, and control temperature, after 55 ~ 65 DEG C of reaction 4h, starts to detect NCO, detects a nco value afterwards every 0.5h;