KR100648124B1 - Paper sizing composition - Google Patents

Abstract

The present invention includes a dispersant system comprising (a) a cellulose reactive sizing agent, (b) a primary anionic dispersant, and a secondary dispersant selected from cationic and / or nonionic dispersants, and (c) inorganic salts. It relates to a paper sizing composition.

Cellulose Reactive Sizing Agents, Dispersants, Dispersant Systems, Inorganic Salts, Sizing Compositions

Description

Paper Sizing Composition

The present invention relates to a paper sizing composition containing (a) a sizing agent, (b) a dispersant system, and (c) an inorganic salt, and also a method for sizing paper using such a composition and such a sizing composition It is about a product made using.

Cellulose reactive sizing agents such as alkyl ketene dimers (AKD) are widely used in the paper industry as a component in sizing dispersion formulations. The utility of such sizing agents stems from the ability to directly bind to hydroxyl groups on the cellulose component of the paper. In largely sizing formulations, sizing agents such as, for example, AKD, are used in combination with dispersant systems comprising cationic starch and / or sodium lignosulfonate. Examples of such dispersions can be found in US Pat. No. 4,861,376 (Edwards) and US Pat. No. 3,223,544 (Savina), the disclosures of which are hereby incorporated by reference herein.

In papermaking processes, the usefulness of inorganic salts such as Alum or aluminum containing salts is also known previously. In fact, these salts significantly improve machine productivity by promoting dehydration. In general, the higher the concentration of salt, the greater the dehydration capacity.

Thus, combinations of organic sizing agents such as AKD dispersions with inorganic salts such as alum are useful combinations, providing both sizing and dehydration capacity. Examples of such combinations are described in US Pat. No. 5,145,522 (Nakagawa et al.) And US Pat. No. 5,627,224 (Lyrmalm et al.), The disclosures of which are hereby incorporated by reference herein. However, in this combination, since the compatibility between the organic sizing agent and the inorganic salt is very poor, there is a problem in that the sizing agent is separated when the concentration of the inorganic salt is too high in the liquid phase of the organic sizing dispersion.

Accordingly, there is a need in the art for dispersant systems compatible with inorganic salts and organic sizing agents. Many dispersant systems have been described in the literature. For example, in US Pat. No. 5,627,224, amphoteric polymers are used alone as dispersants to incorporate polyaluminum compounds in dispersions of AKD. However, it was difficult to achieve good stability in compositions containing organic sizing agents and inorganic salts. Therefore, there is a need in the art for a composition that can solve the above-mentioned problems.

<Overview of invention>

In view of the foregoing, it is an object of the present invention to provide a sizing dispersion with improved stability.

Another object of the present invention is to provide a sizing dispersion with improved dehydration capacity.                 

Another object of the present invention is to provide a sizing dispersion comprising organic sizing agents and inorganic salts of various concentrations, including high concentration inorganic salts.

The present invention also relates to a composition comprising (a) a cellulose reactive sizing agent, (b) a dispersant system comprising a primary dispersant and a secondary dispersant, and (c) an inorganic salt. In addition to the method, it relates to a product comprising the composition.

The present invention is a cellulose reactive sizing agent; A dispersant system comprising an anionic dispersant and at least one cationic or nonionic dispersant; And at least one salt comprising an element in an amount equal to or greater than about 5.5 weight percent aluminum based on the weight of the cellulose reactive sizing agent. In a preferred embodiment, the cellulose reactive sizing agent comprises at least one of ketene dimers and ketene multimers, more preferably the ketene dimer comprises at least one of alkenyl ketene dimers and alkyl ketene dimers. In another preferred embodiment, the cellulose reactive sizing agent comprises at least one of alkenyl succinic anhydride and stearic anhydride.

Cellulose reactive sizing agents are organic epoxides containing about 12 to about 22 carbon atoms, acyl halides containing about 12 to about 22 carbon atoms, fatty acid anhydrides from fatty acids containing about 12 to about 22 carbon atoms Or organic isocyanates containing about 12 to about 22 carbon atoms.

Preferably, the composition of the present invention comprises a ketene dimer or ketene multimer of formula (I):

Wherein n is an integer from 0 to about 20, R and R ₂ are the same or different and are saturated or unsaturated hydrocarbyl groups having from about 6 to about 24 carbon atoms, and R ₁ is from about 2 to about 40 Saturated or unsaturated hydrocarbyl groups with carbon atoms. Preferably n has a value from 0 to about 6, more preferably n is from 0 to about 3, most preferably n is 0. R may be a saturated or unsaturated hydrocarbyl group having about 10 to 20 carbon atoms, preferably R is a saturated or unsaturated hydrocarbyl group having about 14 to 16 carbon atoms. R ₂ is preferably a saturated or unsaturated hydrocarbyl group, and a saturated or unsaturated hydrocarbyl group R ₂ is more preferably having from about 14 to 16 carbon atoms with from about 10 to 20 carbon atoms. Preferably, R ₁ is a saturated or unsaturated hydrocarbyl group having about 4 to 20 carbon atoms.

Anionic dispersants may include polymeric dispersants containing sulfates or sulfonates. Such anionic dispersants include formaldehyde condensates of sodium naphthalene sulfonate, formaldehyde condensates of sodium alkylnaphthalene sulfonate, formaldehyde condensates of sodium phenol sulfonate, formaldehyde condensates of sodium phenol sulfate, and lignosulfo Nates, preferably including sodium lignosulfonate. Sodium lignosulfonate is preferably less than about 5.9 wt%, more preferably less than about 5 wt%, even more preferably less than about 4.5 wt%, even more preferably about 4, based on its total weight Sodium lignosulfonate with sulfonate sulfur of less than, and most preferably less than about 3.6% by weight.

The anionic dispersant may be present in an amount of about 0.02 to about 20 weight percent, more preferably about 0.4 to about 7 weight percent, and most preferably about 0.9 to about 3 weight percent based on the weight of the cellulose reactive sizing agent. have.

Preferred compositions include cationic dispersants, preferably cationic modified starches, cationic modified guars, or low charge cationic polymers. The composition of the present invention is preferably from about 0.4 to about 400 weight percent, more preferably from about 2 to about 100 weight percent, and most preferably from about 10 to about 30 weight percent based on the weight of the cellulose reactive sizing agent. Cationic modified starch in amounts.

Salts may include metals selected from Groups I, II, III, IV, V, and transition metals of the periodic table, and combinations thereof. Preferably, the salt comprises aluminum, magnesium, calcium or barium. Preferably, the composition comprises an aluminum salt of the formula Al _x (SO ₄ ) _y (H ₂ O) _z (where x is 1 to 3, y is 1 to 4 and z is 0 to 20). do. Preferably, the aluminum salt is aluminum sulphate. The aluminum salt may also have the formula Al _n (OH) _m X _3n-m , where X is an anion, n and m are integers greater than zero, and 3n-m are integers greater than zero. . In such salts, the anion preferably comprises chloride or acetate and the aluminum salt comprises polyaluminum chloride.

In one aspect of the invention, the salt may be present in an equivalent amount from about 5.5 wt% aluminum to about 10 wt% aluminum based on the weight of the cellulose reactive sizing agent, more preferably the salt is based on the weight of the cellulose reactive sizing agent And about 6% by weight to about 8% by weight aluminum.

The present invention also provides a cellulose reactive sizing agent; A dispersant system comprising modified sodium lignosulfonate and one or more of cationic dispersants, nonionic dispersants, and combinations thereof; And at least one salt comprising an element in an amount equal to or greater than about 0.2 weight percent aluminum based on the weight of the cellulose reactive sizing agent. In such compositions, the salt may be present in an amount equal to or greater than about 0.4 weight percent aluminum based on the weight of the cellulose reactive sizing agent. The salt is more preferably equivalent or greater than about 1.5 weight percent aluminum, more preferably equivalent or greater than about 3 weight percent aluminum, and even more preferably, based on the weight of the cellulose reactive sizing agent Is equivalent to or greater than about 4.4 weight percent aluminum, even more preferably equivalent or greater than about 5.5 weight percent aluminum, and most preferably equivalent or greater than about 6 weight percent aluminum Present in quantities.

Compositions of the present invention may be present in an amount equivalent to or less than about 40 weight percent aluminum, more preferably in an amount equivalent to or less than about 30 weight percent aluminum, even more preferably about 20 weight based on the weight of the cellulose reactive sizing agent. Amount equivalent to or less than% aluminum, even more preferably amount equivalent to or less than about 15 weight% aluminum, even more preferably amount equivalent to or less than about 12 weight% aluminum, even more preferably about 10 Salts equivalent to or less than weight percent aluminum, and most preferably amounts equivalent to or less than about 8 weight percent aluminum.

The composition of the present invention is equivalent to about 0.2 wt% to about 40 wt% aluminum, more preferably about 0.4 wt% to about 30 wt% aluminum, and even more preferably about 0.2 wt% to about 40 wt% aluminum, based on the weight of the cellulose reactive sizing agent Equivalent to 1.5% to about 20% aluminum by weight, even more preferably about 3% to about 15% by weight aluminum equivalent, even more preferably about 4.4% to about 12% aluminum equivalent by weight, even more Preferably from about 5.5% to about 10% by weight aluminum, and most preferably from about 6% to about 8% aluminum by weight.

The present invention is also accomplished by providing at least one of ketene dimers and ketene multimers, a dispersant system comprising modified sodium lignosulfonate and cationic modified starch, and an aqueous composition comprising aluminum sulfate.

The present invention also provides a cellulose reactive sizing agent; A dispersant system comprising an anionic dispersant and at least one of a cationic dispersant and a nonionic dispersant; And 5.5 weight percent aluminum based on the weight of the cellulose reactive sizing agent and at least one salt comprising an amount of elements in an equivalent or greater than that, to provide an aqueous composition for sizing of paper products.

The present invention also provides a cellulose reactive sizing agent; A dispersant system comprising an anionic dispersant and at least one of a cationic dispersant and a nonionic dispersant; And adding to the cellulosic material at least one salt comprising an element in an amount equal to or greater than 5.5 wt% aluminum based on the weight of the cellulose reactive sizing agent. Is achieved.

The present invention also provides a cellulose reactive sizing agent; A dispersant system comprising an anionic dispersant and at least one of a cationic dispersant and a nonionic dispersant; And at least one salt comprising an element in an amount equal to or greater than 5.5 weight percent aluminum based on the weight of the cellulose reactive sizing agent.

The present invention provides a paper sizing composition comprising an inorganic salt, a dispersant system, and cellulose reactive sizing agents such as ketene dimers. The sizing composition of the present invention is stable even under high concentration of inorganic salt environment. Sizing compositions comprising inorganic salts with dispersants promote the action of reactive sizing agents and improve dehydration efficiency in paper production.

Unless indicated otherwise, all percentages, parts, ratios, and the like mentioned herein are by weight. Moreover, all percentage values in this application are calculated based on 100% of the given sample weight, unless stated otherwise. Thus, for example, 30% represents 30 parts by weight with respect to 100 parts by weight of the sample.

Unless stated otherwise, references to a compound or component include the compound or component itself, as well as combinations with other compounds or components, such as mixtures of compounds. For example, as used herein, the term cellulose reactive sizing agent means to include cellulose reactive sizing agent alone and / or a combination of cellulose reactive sizing agents, and the term inorganic salt refers to inorganic salt alone and / or inorganic. It is meant to include a combination of salts.

The term "hydrocarbyl" as used herein is understood to include "aliphatic", "alicyclic" and "aromatic". Hydrocarbyl groups are understood to include alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl and alkaryl groups. Also, “hydrocarbyl” is understood to include both unsubstituted hydrocarbyl groups and substituted hydrocarbyl groups, wherein substituted hydrocarbyl groups represent hydrocarbon moieties that carry additional substituents in addition to carbon and hydrogen.

As used herein, the term "stable" means that the claimed composition meets the following three criteria: 1) the composition does not form a gel for at least two weeks of maturation; 2) the aqueous composition maintains a viscosity of less than 5,000 centipoise for at least two weeks during the ripening period; And 3) the aqueous composition does not separate into separate phases for at least two weeks of maturation. Each criterion is described below.

The first criterion is the absence of gel formation. Gel or gel formation as used herein means that the composition exhibits solid-like behavior under the action of mechanical force. Gel formation is tested as follows: Immediately after preparing the composition, two samples are placed in a 100 g bottle. The first bottle is tested immediately for gel formation. For gel formation, test simply by observing the sample while slowly tilting to 15 °. If the sample does not flow, the gel is considered to have formed. The second bottle is stored for 2 weeks at 32 ° C. and then tested for gel formation. Gel formation is measured at room temperature.

The second criterion is viscosity. The viscosity of the sample is preferably less than 5,000 centipoise, more preferably less than 4,000 centipoise, even more preferably less than 3,000 centipoise, even more preferably less than 1,000 centipoise, even more preferably Less than 500 centipoise, even more preferably less than 300 centipoise, and most preferably less than 200 centipoise. Viscosity is measured using a Brookfield DV-II viscometer. The choice of spindle and speed (RPM) is readily determined by one skilled in the art. The viscosity is tested as follows: Immediately after the composition is prepared, two 100 g samples are placed in a 100 g bottle. The first bottle is tested immediately for viscosity. The second bottle is stored for 2 weeks at 32 ° C. and then tested for viscosity. Before testing, each sample bottle should be allowed to come to room temperature.

A third criterion is the separation measured as total solids underneath the aqueous composition. The lower total solids (BTS%) should not change by more than 20% when aged at 25 ° C. within 2 weeks. The lower total solids do not vary more preferably by more than 15%, even more preferably by more than 10%, and most preferably by more than 5%.

The bottom total solid is tested as follows: Immediately after the composition is prepared, two 100 g samples are placed in a 100 g bottle. The first bottle is tested immediately for the lower total solids. The second bottle is aged for 2 weeks at 25 ° C. and then tested for the lower total solids. Lower total solids are measured by pipetting a certain amount from the "bottom" of each sample. Sampling is preferably performed by contacting the pipette with the bottom of the 100 g bottle containing the sample and withdrawing about 2 g of sample. 1.5 g from the about 2 g sample is placed in an aluminum weighing dish. A 1.5 g sample taken with a pipette is heated in an oven at 150 ° C. for about 45 minutes. The percentage of nonvolatile components in the dispersion is determined by measuring the mass remaining after drying. The residual percentage of the sample obtained from the bottom of 100 g of the vial containing the sample is called "bottom total solids" BTS%. Percent change on maturation is calculated by comparing the bottom total solids from the aged sample with the bottom total solids from the unaged sample.

In the description of the stability criteria, a maturation period of 2 weeks is considered to be preferred. More preferably, even after one month or more, this criterion is still met, even more preferably, even after three months. Most preferably, the compositions of the present invention meet the stability criteria even after six months.

The composition of the present invention comprises a dispersant system comprising a secondary dispersant comprising (a) a cellulose reactive sizing agent, (b) a primary anionic dispersant, and at least one dispersant selected from cationic or nonionic dispersants, and ( c) inorganic salts. Details of components (a), (b) and (c) are described below.

Cellulose reactive sizing agents

Cellulose reactive sizing agents suitable for use in the present invention include sizing agents which are thought to be capable of reacting with hydroxyl groups of cellulose to form covalent chemical bonds. Cellulose reactive sizing agents (preferably hydrophobic) suitable for use in the present invention may act in the final product as a water-repellant.

Preferred cellulose reactive sizing agents include ketene dimers and multimers such as alkyl ketene dimers (AKD) and alkenyl ketene dimers; Alkenyl succinic anhydride (ASA); Stearic anhydride; Organic epoxides containing about 12 to about 22 carbon atoms; Acyl halides containing about 12 to about 22 carbon atoms; Fatty acid anhydrides from fatty acids containing about 12 to about 22 carbon atoms; And organic isocyanates containing about 12 to about 22 carbon atoms.

The ketene dimers and multimers used according to the invention preferably have formula (I):

<Formula I>

Wherein n is an integer from 0 to about 20 or more, preferably 0 to 6, more preferably 0 to 3, and most preferably 0. R and R ₂ may be the same or different and may be saturated or have about 6 to about 24 carbon atoms, preferably about 10 to about 20 carbon atoms, and most preferably about 14 to about 16 carbon atoms Unsaturated hydrocarbyl group. R ₁ is a saturated or unsaturated hydrocarbyl group having about 2 to about 40 carbon atoms, preferably about 4 to about 20 carbon atoms. Preferably at least about 25% of the R and R ₂ groups are unsaturated.

Preferably, the ketene dimer is (a) octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, phenyl, benzyl, β-naphthyl and cyclohexyl ketene dimers, And / or (b) montanic acid, naphthenic acid, 9,10-decylene acid, 9,10-dodecylene acid, palmitoleic acid, oleic acid, ricinoleic acid, linoleic acid, eleostearic acid, and coconut oil, Naturally occurring fatty acids found in babassu oil, palm kernel oil, palm oil, olive oil, peanut oil, rapeseed oil, bovine oil, lard, whale oil and any mixture of the above-mentioned fatty acids Ketene dimers prepared from organic acids such as one or more of these mixtures. Most preferred ketene dimers are selected from the group consisting of octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, phenyl, benzyl, β-naphthyl and cyclohexyl ketene dimers .

Alkyl ketene dimers have been used commercially for many years and are prepared by dimerization of alkyl ketenes made from saturated straight-chain fatty acid chlorides, the most widely used being from palmitic acid and / or stearic acid. Aqueous dispersions of these materials are available from Hercules Incorporated, Wilmington, DE as Hercon® paper sizing agents.

The ketene multimers for use in the process of the invention are those wherein n is an integer of at least 1; R and R ₂ may be the same or different and are saturated or unsaturated straight or branched chain having 6 to 24 carbon atoms, preferably 10 to 20 carbon atoms, and most preferably 14 to 16 carbon atoms An alkyl group; R ₁ is a saturated or unsaturated straight or branched chain alkylene group having 2 to 40 carbon atoms, preferably 4 to 8 or 28 to 40 carbon atoms.

Ketene multimers are described in European Patent Application Publication No. 0,629,741 A1, US Patent No. 5,685,815, and PCT International Publication No. WO 97/30218, each of which is incorporated herein by reference in its entirety. It is considered to be included.

Ketene dimers and multimers for use in the present invention include those which are solid or not solid at 25 ° C. (not substantially crystalline, semicrystalline or waxy solids, ie flow on heating without melting heat) It includes).

The ketene dimers and multimers have n preferably 0 to 6, more preferably 0 to 3, and most preferably 0; R and R ₂ may be the same or different and are a saturated or unsaturated straight or branched chain alkyl group having 6 to 24 carbon atoms; R ₁ is a saturated or unsaturated straight or branched chain alkylene group having 2 to 40 carbon atoms, preferably 4 to 32 carbon atoms; It may be a mixture of the above compounds of formula I wherein at least 25% of the R and R ₂ groups in the mixture of compounds are unsaturated.

Ketene dimers and multimers may include mixtures of ketene dimers or multimeric compounds that are the reaction products of a reaction mixture comprising unsaturated monocarboxylic fatty acids. The reaction mixture may further comprise saturated monocarboxylic fatty acids and dicarboxylic acids. Preferably, the reaction mixture for preparing the mixture of dimers or multimer compounds comprises at least 25% by weight unsaturated monocarboxylic fatty acids, more preferably at least 70% by weight unsaturated monocarboxylic fatty acids.

Unsaturated monocarboxylic fatty acids included in the reaction mixture preferably have 10 to 26 carbon atoms, more preferably 14 to 22 carbon atoms, and most preferably 16 to 18 carbon atoms. These acids include, for example, oleic acid, linoleic acid, dodecenoic acid, tetradecenoic acid (myristoleic acid), hexadecenoic acid (palmitoleic acid), octadecadenoic acid (linolelideic acid), octadecatrienic acid (linolenic acid). ), Eicosenoic acid (gadoleic acid), eicosaterateic acid (arachidonic acid), cis-13-dococenic acid (erusic acid), trans-13-docosenoic acid (brasidic acid) and docosapentaenoic acid (clue) Panodonic acid), and their acid halides (preferably chloride). One or more monocarboxylic acids may be used. Preferred unsaturated monocarboxylic fatty acids are oleic acid, linoleic acid, linolenic acid and palmitoleic acid, and acid halides thereof. Most preferred unsaturated monocarboxylic fatty acids are oleic acid and linoleic acid, and their acid halides.

The saturated monocarboxylic fatty acids used to prepare the ketene dimers and multimer compounds for use in the present invention are preferably 10 to 26 carbon atoms, more preferably 14 to 22 carbon atoms, and most preferably Has 16 to 18 carbon atoms. These acids include, for example, stearic acid, isostearic acid, myristic acid, palmitic acid, margaric acid, pentadecanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, nonadecanoic acid and arachidic acid. And behenic acid, and their halides (preferably chloride). One or more saturated monocarboxylic fatty acids may be used. Preferred acids are palmitic acid and stearic acid.

The alkyl dicarboxylic acid used to prepare the ketene multimer compound for use in the present invention preferably has 6 to 44 carbon atoms, more preferably 9 to 10, 22 or 36 carbon atoms. Such dicarboxylic acids include, for example, sebacic acid, azelaic acid, 1,10-dodecanedioic acid, suberic acid, brazilic acid, docosandioic acid, and C ₃₆ dimer acids, for example Henkel-Emery EMPOL 1008 available from Emery, Cincinnati, Ohio, and their halides (preferably chloride). One or more of these dicarboxylic acids may be used. More preferred are dicarboxylic acids having 9 to 10 carbon atoms. Most preferred dicarboxylic acids are sebacic acid and azelaic acid.

When dicarboxylic acid is used in the preparation of the ketene multimers for use in the present invention, the maximum molar ratio of the dicarboxylic acid to the monocarboxylic acid (sum of both saturated and unsaturated) is preferably about 5. A more preferred maximum is about 4 and the most preferred maximum is about 2. Mixtures of dimers and multimeric compounds can be prepared using methods known for the preparation of standard ketene dimers. In the first step, an acid halide (preferably acid chloride) is produced from a mixture of fatty acids or a mixture of fatty acids and dicarboxylic acids using PCI ₃ or another halogenating agent (preferably a chlorinating agent). The acid halide is then converted to ketene in the presence of tertiary amines (including trialkyl amines and cyclic alkyl amines), preferably triethylamine. This ketene residue is then dimerized to yield the desired compound.

Ketene dimers and multimers are described in US Pat. No. 5,685,815 and PCT International Publication No. WO 97/30218, each of which is incorporated by reference herein in its entirety. Ketene dimers are also available from Hercules Incorporated as Precis sizing agents.

Alkenyl succinic anhydrides (ASA) according to the invention preferably consist of unsaturated hydrocarbon chains containing pendant succinic anhydride groups. It is usually made in a two step process starting from alpha olefins. First, the olefins are isomerized by randomly moving double bonds from the alpha position. In the second step, the isomerized olefin is reacted with maleic anhydride to obtain the final ASA of Formula II:

Typical olefins used in the reaction with maleic anhydride include alkenyl, cycloalkenyl and aralkenyl compounds containing about 8 to about 22 carbon atoms. Specific examples include isooctadecenyl succinic anhydride, n-octadecenyl succinic anhydride, n-hexadecenyl succinic anhydride, n-dodecyl succinic anhydride, i-dodecenyl succinic anhydride, n-decenyl succinic anhydride and n-oxane There is tenyl succinic anhydride.

Alkenyl succinic anhydrides are described in US Pat. No. 4,040,900, which is hereby incorporated by reference in its entirety, and in CE Farley and RB Wasser in The Sizing of Paper, Second Edition , edited by WF Reynolds, Tappi Press, 1989, pages 51-62. Various alkenyl succinic anhydrides are commercially available from Albemarle Corporation (Baton Rouge, Louisiana). Alkenyl succinic anhydrides for use in the present invention are preferably liquid at 25 ° C. More preferably, it is a liquid at 20 degreeC.

The amount of cellulose reactive sizing agent is preferably an amount sufficient to provide a sizing effect to the composition. As a lower limit, the amount of cellulose reactive sizing agent in the composition preferably exceeds about 1 weight percent of the weight of the aqueous composition, more preferably about 5 weight percent of the weight of the aqueous composition, and most preferably the aqueous composition. Greater than about 7 weight percent of the weight. As an upper limit, the amount of the cellulose reactive sizing agent is preferably less than about 50% by weight of the aqueous composition weight, more preferably less than 30% by weight of the aqueous composition weight, and most preferably 15% by weight of the aqueous composition weight. Is less than. By range, the amount of cellulose reactive sizing agent in the composition is preferably about 1 to about 50 weight percent of the weight of the aqueous composition, more preferably about 5 to about 30 weight percent of the weight of the aqueous composition, most preferably aqueous From about 7 to about 15 weight percent of the weight of the composition.

Dispersant system

The composition of the present invention preferably further comprises a dispersant system which serves to stabilize the composition. Dispersant systems include primary and secondary dispersants. The terms "primary" and "secondary" are used herein for convenience of reference and are not intended to be limiting in any way. Primary dispersants include one or more anionic dispersants. Suitable anionic dispersants include, but are not limited to, polymer dispersants containing sulfonates and sulfates as functional groups. Examples of such anionic dispersants include formaldehyde condensates of sodium naphthalene sulfonate, formaldehyde condensates of sodium alkylnaphthalene sulfonate, formaldehyde condensates of sodium phenol sulfonate, formaldehyde condensates of sodium phenol sulfate, and sodium Lignosulfonates, including but not limited to lignosulfonates and modified sodium lignosulfonates.

Particularly preferred anionic dispersants are those which provide stability to the composition even in the presence of large amounts of inorganic salts. Preferably, the anionic dispersant comprises at least one lignosulfonate. Preferably, the lignosulfonate is a Norlig 12F? (Lignotech, USA Inc., WI), such as lignosulfonate with increased hydrophobicity compared to normal lignosulfonate, which is comparable to lignosulfonate without modification of the hydrophilic-lipophilic balance (HLB). It is shifted to a more hydrophobic value. Thus, preferred lignosulfonates are hydrophobic lignosulfonates. The hydrophobic increase of lignosulfonate can be achieved in a number of ways, but is preferably achieved by reducing the weight percentage of sulfonate sulfur in lignosulfonate. A general description of how to modify lignosulfonate, and in particular to reduce the concentration of sulfonate sulfur, is described in "A Working Chemist's Guide to the Chemistry of Lignosulphonates," pages 1-12, Reed Inc., Chemical Division ( Quebec, Canada), which is hereby considered to be incorporated by reference in its entirety.

Preferred lignosulfates are less than about 5.9 weight percent, more preferably less than about 5 weight percent, even more preferably less than 4.5 weight percent, even more preferably about 4 weight percent based on the total weight of sodium lignosulfonate Sodium lignosulfonate comprising less than%, and most preferably about 3.6% by weight of sulfonate sulfur. Sodium lignosulfate preferably comprises more than about 0.5 weight percent, more preferably more than about 1.5 weight percent, and most preferably more than about 2.5 weight percent sulfur, based on its total weight. do. Preferred sodium lignosulfonate is from about 0.5% to about 5.9%, more preferably from about 1.5% to about 5%, and most preferably from about 2.5% to about 4% by weight based on its total weight Wt% sulfonate sulfur.

The molecular weight of suitable sodium lignosulfonate is preferably greater than about 2,000 g / mol, more preferably greater than about 5,000 g / mol, most preferably greater than about 10,000 g / mol. Suitable sodium lignosulfates preferably have a molecular weight of less than about 150,000 g / mol, more preferably less than 120,000 g / mol, and most preferably less than 80,000 g / mol. The preferred molecular weight range of sodium lignosulphate is about 2,000 g / mol to about 150,000 g / mol, more preferably about 5,000 g / mol to about 120,000 g / mol, most preferably about 10,000 g / mol to about 80,000 g / mol.

Anionic dispersants are preferably used in amounts of greater than about 0.01 weight percent, more preferably greater than about 0.05 weight percent, and most preferably greater than about 0.1 weight percent based on the weight of the aqueous composition. Anionic dispersants are preferably used in amounts of less than about 10 weight percent, more preferably less than about 5 weight percent, and most preferably less than about 3 weight percent based on the weight of the aqueous composition. The range for the amount of the anionic dispersant is preferably from about 0.01 to about 10% by weight, more preferably from about 0.05 to about 5% by weight, most preferably from about 0.1% by weight to the weight of the aqueous composition. About 3% by weight.

The amount of anionic dispersant may also be expressed as a percentage of the weight of the cellulose reactive sizing agent. The anionic dispersant is preferably about 0.02 to about 20 weight percent of the weight of the cellulose reactive sizing agent, more preferably about 0.40 to about 7 weight percent of the weight of the cellulose reactive sizing agent, and most preferably the weight of the cellulose reactive sizing agent. From about 0.90 to about 3% by weight.

Suitable examples of high hydrophobic sodium lignosulfonates include Dynasperse LCD? (Lignotech USA, Inc., WI), and examples of sodium lignosulfonate include Norriq 12F? (Lignotech, USA Inc., WI).

The dispersant system further includes a secondary dispersant that can act as a stabilizer. Suitable secondary dispersants include those which are not anionic dispersants. That is, it is suitable to include cationic dispersants and / or nonionic dispersants. Cationic dispersants are dispersants whose net charge is a positive charge. Cationic dispersants include, but are not limited to, cationic modified starch and guar, or low charge cationic polymers. The low charge cationic polymer preferably has less than 51% repeat units carrying a (+) charge in the polymer and the remaining repeat units have no charge or have a (-) charge, provided that the net charge on the polymer Polymers that are charged). Low charge cationic polymers include Kymenene® 557H, LX, SLX and ULX (Hercules Incorporated, Wilmington, DE), polyaminopolyamide-epichlorohydrin resins, and Mercquat 550 (Calgon Corporation). , Pittsburgh, PA). Polyaminopolyamide-epichlorohydrin resins are described in US Pat. No. 4,470,742 (Bull et al.), US 5,714,552 (Bower), US 5,171,795 (Miller et al.) And US 5,614,597 (Bower), Each of these documents is deemed to be incorporated herein by reference in their entirety through this name. The use of cationic polymers in sizing compositions is generally described in US Pat. Nos. 4,243,481, 4,240,935, 4,279,794, 4,295,931, 4,317,756 and 4,522,686 (all Dumas). Each of which is considered to be incorporated herein by reference in its entirety through this name. Nonionic dispersants include, but are not limited to, any water soluble nonionic polymer, such as starch and polyethylene oxide. Secondary dispersants preferably include cationic modified starches.

Secondary dispersants are preferably used in amounts of greater than about 0.2 weight percent, more preferably greater than about 0.5 weight percent, and most preferably greater than about 1 weight percent. Secondary dispersants are preferably used in amounts of less than 20% by weight, more preferably less than 5% by weight, and most preferably less than 3.5% by weight. The amount of secondary dispersant is preferably from about 0.2 to about 20 weight percent, more preferably from about 0.5 to about 5 weight percent, and most preferably from about 1 to about 3.5 weight percent, based on the weight of the aqueous composition. Range.

The amount of secondary dispersant may also be expressed as a percentage of the weight of the cellulose reactive sizing agent used. The secondary dispersant is preferably from about 0.4 to about 400 weight percent of the weight of the cellulose reactive sizing agent, more preferably from about 2 to about 100 weight percent of the weight of the cellulose reactive sizing agent, and most preferably of the weight of the cellulose reactive sizing agent. About 10 to about 30 weight percent.

Preferred secondary dispersants include starches including optional water soluble cationic starches and the like. Preferred starches include cationic waxy corn starches having tertiary or quaternary amino groups as charge sources. Preferred viscosity ranges of starch are low to medium viscosity.

The viscosity of the starch solution can be obtained by heating the starch for 30 minutes at pH 4.5 to 6 in 95 ° C water. As used herein, median viscosity means Brookfield viscosity which is about 101 to about 2000 centistokes measured at 100 rpm and 38 ° C. with spindle 2 using 10% by weight starch solution. Low viscosity, as used herein, means Brookfield viscosity which is about 1 to 100 centistokes measured at 100 rpm and 38 ° C. with spindle 2 using 10 wt% starch solution. Examples of preferred starches are A. a. this. Star lok? 140 manufactured by A. E. Staley Manufacturing Company (Illinois).

Inorganic salt

The composition of the present invention comprises a salt (preferably an inorganic salt). Preferably, the salt is a compound that enhances dehydration. Inorganic salts may also perform other actions in the composition, while preferred inorganic salts perform the above actions. For example, the inorganic salt (s) may also act to improve the retention of sizing agents.

Preferably, the inorganic salt is from an alkaline earth metal (Group II of the periodic table) salt, an alkali metal (Group I of the periodic table) salt, or a transition metal (of the periodic table) or metals of Groups III, IV and V (of the periodic table) Metal salts, which may be salts formed. Any number of salts, including salts of magnesium, barium, aluminum and calcium, are useful in this respect, but are preferably selected from aluminum salts and calcium salts. Suitable aluminum salts include aluminum sulfates of the formula Al _x (SO ₄ ) _y (H ₂ O) _z (where x is 1 to 3, y is 1 to 4, z is 0 to 20) It is not limited to this. Suitable aluminum sulfate called Alum is commercially available (General Chemical Corporation, NJ). Other aluminum salts include the formula Al _n (OH) _m X _3n-m , where X is an anion such as chloride or acetate, and n and m are integers greater than zero such that (3n-m) is greater than zero. Polyaluminum compounds are included. When X is chloride, the salt is polyaluminum chloride (PAC). Calcium salts suitable for use in the present invention preferably have the formula CaY _n ( _wherein Y is an anion such as chloride, acetate or nitrate and n is 1 to 2). Mixtures of salts may also be used.

When using an aluminum salt, the amount is preferably from about 0.02% to about 2% by weight, more preferably from about 0.04% to about 1.5% by weight, and most preferably about 0.08% by weight of the aqueous composition. % To about 0.8% by weight of aluminum. When calcium salt is used, the amount is preferably about 0.04% to about 4.4% by weight, more preferably about 0.1% to about 3.3% by weight, and most preferably about 0.2% by weight, based on the weight of the aqueous composition. % To about 2% by weight calcium element.

If present, the amount of aluminum element can be expressed as weight percent of the cellulose reactive sizing agent used. Preferably, the elemental aluminum is greater than about 0.2 weight percent, more preferably greater than about 0.4 weight percent, even more preferably greater than about 1.5 weight percent, even more preferably greater than about 3 weight percent of the cellulose reactive sizing agent weight. , Even more preferably greater than about 4.4 wt%, even more preferably greater than about 5.5 wt%, and most preferably greater than about 6 wt%. Preferably, the aluminum element is less than about 40 weight percent, more preferably less than about 30 weight percent, even more preferably less than about 20 weight percent, even more preferably less than about 15 weight percent of the cellulose reactive sizing agent weight. , Even more preferably less than about 12 weight percent, even more preferably less than about 10 weight percent, and most preferably about 8 weight percent. In terms of the range, the aluminum element is preferably about 0.2% to about 40% by weight, more preferably about 0.4 to about 30% by weight, even more preferably about 1.5 to about 20% by weight of the cellulose reactive sizing agent weight. %, Even more preferably about 3 to about 15 weight percent, even more preferably about 4.4 to about 12 weight percent, even more preferably about 5.5 to about 10 weight percent, and most preferably about 6 to about Present in an amount of 8% by weight.

The amount of metal salt used according to the invention can be determined by its equivalent to aluminum. For the purposes of this disclosure, the equivalent amount for aluminum is determined by calculating the atomic weight for the charge ratio of the metal element (s) in the salt. For example, since the atomic weight of aluminum is 27 and the charge is 3 ⁺ , the atomic weight for the charge ratio is converted to 9 (27/3). The atomic weight of calcium is 40 and the charge is 2 ^+, so the atomic weight to charge ratio is 20. To determine the equivalent amount of calcium to aluminum, the atomic weight of the charge ratio of calcium is divided by the atomic weight 9 of the charge ratio of aluminum to be 2.2. The number 2.2 obtained is a multiplier for determining the weight of the calcium equivalent to the weight of aluminum. Thus, if 1 gram of aluminum is needed, 2.2 grams of calcium will be equivalent. As another example, the multiplier for magnesium (24/2 = 12) is 1.3 (12/9), the multiplier for sodium (23/1 = 23) is 2.6 (23/9), and beryllium (9/2 = Multiplier for 4.5) is 0.50 (4.5 / 9) and multiplier for lithium (6.9 / 1 = 6.9) is 0.77 (6.9 / 9). These transformations are applicable to any metal. By using this equation, any number of different inorganic salts can be combined to achieve the desired effect.

As an example, considering Example 1 below, 445.6 g of a 48.5% solution of Alum (aluminum sulfate, Al ₂ (SO ₄ ) ₃ .14H ₂ O, MW 594) was substituted with 222.8 g of AKD (cellulose reactive sizing agent). To the sample having. The above amounts of alum comprise 19.6 g of aluminum (445.6 x 0.485 = 216.116; 216.116 g of aluminum sulphate x 54 g of aluminum / 594 g of aluminum sulphate = 19.6 g of aluminum). Using this conversion, the amount of aluminum described above is 43.2 g of calcium (19.6 x 2.2), 25.5 g of magnesium (19.6 x 1.3), 9.8 g of beryllium (19.6 x 0.5) and 15.1 g of lithium (19.6). X 0.77). Thus, one inorganic salt can be easily replaced with another, or different salts can be mixed without any difficulty. In addition, the nonmetallic part of the salt should not be taken into account in the equivalence calculation. For example, in aluminum sulfate, the atomic weight relative to the charge ratio of the sulfate is not taken into account.

Thus, as used herein, the amount of aluminum and the amount of elements that are "equivalent" are equivalent amounts using this conversion. For example, the amount of calcium, magnesium or barium equivalent to X weight percent aluminum is determined using this conversion. In short, this will involve determining the number of grams of aluminum in X weight percent aluminum. A simple conversion is made from the gram number of aluminum to determine the amount of calcium, magnesium or barium equivalent to X weight percent aluminum.

And of course, the quantity of aluminum which is equivalent to the quantity of aluminum is the same quantity. Thus, the "amount of aluminum equivalent to 6% by weight aluminum" is 6% by weight aluminum. This is a clear fact that is clearly shown here.

This simple conversion method also applies to quantities related to the amount of aluminum. For example, as used herein, the amount of element that is "greater than" or "less than" the amount of aluminum is an amount that is greater than or less than the amount using the transformation. For example, the amount of calcium, magnesium or barium above X wt% aluminum is determined using this conversion. In short, this will involve determining the number of grams of aluminum in X weight percent aluminum. A simple conversion is made from the gram number of aluminum to determine the amount of calcium, magnesium or barium above X wt% aluminum.

Other ingredients customary in papermaking techniques, such as biocides, clays, calcium carbonates, titanium dioxide, nonionic surfactants, fluorescent brighteners, retention aids and drainage aids, can be used in their usual ranges, These are found or expected to be compatible with the compositions described above. Water is used to make the total composition 100%.

The present invention can be used for internal sizing that adds the sizing dispersion to the pulp slurry at the wet end of the papermaking process, or for surface sizing for applying the sizing dispersion in a press or coater. The invention may be used in one or both parts of a two-part sizing system. For example, one part may be mixed internally with wood pulp and the second part may be applied to a sizing agent press, which is a routine procedure in papermaking.

Without further elaboration, it is believed that one skilled in the art can, using the above description, utilize the present invention to its fullest extent. Accordingly, the specific preferred embodiments below are for illustrative purposes only and are not intended to limit the remainder of the disclosure in any way. All parts or percentages are by weight unless otherwise indicated.

All patents and documents cited above and below are hereby considered to be incorporated by reference herein in their entirety.

<Example 1>

Preparation of Sizing Dispersion

AKD sizing dispersions were prepared as follows. 5.6 g of unmodified sodium lignosulfonate (Norrig 12F ?, Lignotech, USA Inc., containing about 6% sulfonate sulfur) and 1269.2 g of water Was added to a jet cooker. Stirring was performed until the Norlig 12F® was completely dissolved. 55.8 g of cationic starch (Sta Lok 169 ?, AE Staley Mfg. Co., Illinois) was added to the cooker. The cooker was steam-heated to 95 ° C. for 60 minutes and the inside of the cooker was stirred during cooking. The mixture formed is a mixed dispersant system. The mixture was then cooled to 70 ° C. and 222.8 g of AKD (Aquapel 364 ?, Hercules Incorporated, Delaware) and 1.2 g of biocide (AMA 424 ?, Georgia) Of Vinnings Indus.) Was added. Stir at 70 ° C. for 5 minutes. The mixture was then homogenized under a pressure of 211 kg / cm ² using a 15 M Gaulin Laboratory Homogenizer (Gaulin Corporation, Mass.), Then quickly to 25 ° C. Cooled. After cooling, AKD sizing dispersion (I) was prepared by adding 445.6 g of 48.5% Alum solution (General Chemical Co., NJ) while stirring.

<Example 2>

Preparation of Sizing Dispersion

Similarly, AKD sizing dispersions prepared with sodium lignosulfonate exhibiting relatively high hydrophobicity according to the present invention were prepared as follows. 5.6 g of sodium lignosulfonate (Dynasper's LCD ?, Ligtech, WA Inc.) containing about 3.6% sulfonate sulfur and 1269.2 g of water were added to the jet cooker. Stirring was performed until the Dynasper LCD® completely dissolved. 55.8 g of cationic starch (Star Lock 169®, A. E. Starlay MFC Co., Illinois) was added to the cooker. The cooker was steam-heated to 95 ° C. for 60 minutes and the inside of the cooker was stirred during cooking. The mixture formed is a mixed dispersant system. The mixture was then cooled to 70 ° C. and 222.8 g of AKD (Aquafel 364 ?, Hercules Incorporated, Delaware) and 1.2 g of biocide (AMA 424 ?, Binnings, GA) Indus.) Was added. Stir at 70 ° C. for 5 minutes. The mixture was then homogenized under a pressure of 211 kg / cm ² using a 15 M Gaulin Labortori homogenizer (manufactured by Gaulin Corporation, Mass.) And then quickly cooled to 25 ° C. After cooling, 445.6 g of 48.5% Alum solution (General Chemical Co., NJ) was added with stirring to prepare AKD sizing dispersion (II). Similarly, AKD sizing dispersion (III) was prepared by adding 222.8 g of alum solution and dispersion (IV) was prepared by adding 89.1 g of alum solution. Sizing Dispersion (V) was prepared similarly to Dispersion (II) except that Dynasper LCD® was not added. Sizing Dispersion (VI) was prepared similar to Dispersion (II) except that no cationic starch was added.

<Example 3>

Viscosity stability tests were performed using the dispersions prepared in Examples 1 and 2. Viscosity was measured at 1 spindle at 60 RPM using a Brookfield DV-II viscometer. Immediately after the dispersion was prepared, the viscosity of the dispersion was measured. Subsequently, the viscosity was measured after aging at 32 ° C. for 2 weeks. The results are summarized in Table 1. The viscosity of the dispersion in Samples I to IV using a mixed dispersant system is stable, but in Samples V and VI using cationic starch or Dynasper LCD, respectively, as the only dispersant, the dispersion formed or separated a gel.

Dispersion number Viscosity (initial value, cp) Viscosity (2 weeks, cp) I 40 61 II 31 27 III 49 61 IV 41 85 V 32 Forming a gel VI 11 Detached

<Example 4>

The layering stability test was performed using the dispersions prepared in Examples 1 and 2. Typically, 1.5 g of the dispersion was placed in an aluminum disk and heated in a 150 ° C. oven for 45 minutes. The percentage of nonvolatile content in the dispersion as measured by this heating method is called "bottom total solids" (BTS%). Immediately after preparation of the dispersion, the BTS% of the dispersion was measured. Then, 100 g of the dispersion was placed in a 100 g glass bottle. After two weeks of aging at 25 ° C., the BTS% of the sample was measured again from the bottom of the bottle. If the difference between the two BTS% data is small, the dispersion is considered to be stable from layering. The results are summarized in Table 2. Dispersion I prepared from a mixed dispersant system of unmodified sodium lignosulfonate and cationic starch showed high levels of layering after two weeks of aging. However, Samples II to IV made with a mixed dispersant system of hydrophobic sodium lignosulfonate and cationic starch were stable from layering. Dispersion V prepared with cationic starch, the only dispersant, showed low layer formation but failed the viscosity stability test as shown in Table 1. Dispersion VI prepared from hydrophobic sodium lignin sulfonate, the only dispersant, was isolated.

Dispersion number BTS% (initial value) BTS% (2 weeks, lower) I 20.5 18.7 II 20.5 20.0 III 18.7 18.6 IV 16.6 16.4 V 17.0 16.9 VI 16.2 Detached

Example 5                 

Control samples Hercon 70? Prepared by dispersions II, III and IV prepared in Example 2, and Hercules Incorporated, Delaware. Drainage efficiency test was performed using a paper sizing dispersion. The test was performed using a Canadian Standard Freeness (CSF) tester according to the method described in SCAN-C21: 65. Old corrugated cardboard regeneration vessel (OCC) pulp, purified to 400 CSF, was mixed with water to prepare a 0.2% slurry. The sizing agent dispersion was added so as to have an AKD of 0.04% based on the pulp dry weight. 0.50% Star Lock 400? Starch (A. E. Starlay MFC Co., Illinois) and 0.025% Reten-1523H? (Hercules Inc., Delaware) was also added to the slurry. The pH of the slurry was adjusted to 7.0. The degree of freedom (CSF) of the mixture was measured and the results are summarized in Table 3. Dispersions II to IV showed significant improvement in fold compared to the control group Hercon 70 ?.

Dispersion number CSF (ml) II 510 III 465 IV 500 Hercon 70? 420

<Example 6>

The aqueous dispersions II, III and IV of Example 2 were used with the control sample Hercon 70 'to prepare papers that were internally sized in a pilot paper machine. Paper was made from old corrugated cardboard regeneration container (OCC) pulp beaten with a Canadian standard freedom of 350 and made from sheets having a basis weight of 40 pounds / 3000 ft ² (18.14 kg / 278.7 m ² ) at pH 7.0. The paper sheet was dried in a reel to 5.0% moisture content. The sizing agent dispersion was added to the thick stock and then diluted in a fan pump. The addition amount was AKD of 0.0225%-0.068% based on paper dry weight. 38.0% sodium sulfate (Haviland Chemical Co., Michigan), 0.15% Alum (General Chemical Corporation, NJ) and 0.025% Leten-1523H? Hercules Incorporated was also used for papermaking. The paper sheet was dried in a reel at 5.0% moisture content. Sizing was tested using the Hercules Size Test (HST). In the HST test, a sheet of sized paper was placed under an ink solution containing 1% formic acid and 1.2% Naphtol Green B. The reflectance of the paper on the opposite side of the solution was first measured and then monitored until the reflectance decreased due to ink penetration. HST time (seconds) is the time taken for the reflectance to decrease to 80% of the initial value. Table 4 summarizes the sizing results. The results from Table 4 show that at both high and low AKD loadings, dispersions II to IV had significantly higher sizing than control Hercon 70 ?.

Dispersion number AKD% HST (seconds) II 0.0225 71 III 0.0225 99 IV 0.0225 81 Hercon 70? 0.0225 48 II 0.045 1089 III 0.045 1182 IV 0.045 1348 Hercon 70? 0.045 704

From the above description, those skilled in the art can readily identify the essential features of the present invention, and various changes and modifications can be made to the present invention to suit various applications and conditions without departing from the spirit and scope of the present invention.

Claims (72)

Cellulose reactive sizing agents, A dispersant system comprising lignosulfonate having less than 5.9% by weight sulfonate sulfur based on the total weight of sodium lignosulfonate, and one or more of cationic and nonionic dispersants, and At least one salt containing at least one metal element An aqueous paper sizing composition comprising a. The composition of claim 1, wherein the lignosulfonate comprises less than 5 weight percent sulfonate sulfur based on the total weight of sodium lignosulfonate. The composition of claim 2, wherein the lignosulfonate comprises less than 4.5 weight percent sulfonate sulfur based on the total weight of sodium lignosulfonate. 4. The composition of claim 3, wherein the lignosulfonate comprises less than 4 weight percent sulfonate sulfur based on the total weight of sodium lignosulfonate. delete delete delete delete delete The composition of claim 1, wherein the salt is present in an amount such that at least one metal element is present in an amount equal to or greater than 4.4 wt% aluminum based on the weight of the cellulose reactive sizing agent. delete The composition of claim 10, wherein the salt is present in an amount such that at least one metal element is present in an amount equal to or greater than 6 wt% aluminum based on the weight of the cellulose reactive sizing agent. The composition of claim 1, wherein the salt is present in an amount such that at least one metal element is present in an amount equal to or less than 40 wt% aluminum based on the weight of the cellulose reactive sizing agent. delete delete delete delete delete delete 5. The composition of claim 4, wherein the salt is present in an amount such that at least one metal element is present in an amount equivalent to 0.2 to 40 weight percent aluminum based on the weight of the cellulose reactive sizing agent. 21. The composition of claim 20, wherein the salt is present in an amount such that at least one metal element is present in an amount equivalent to 0.4 to 30 weight percent aluminum based on the weight of the cellulose reactive sizing agent. The composition of claim 21, wherein the salt is present in an amount such that at least one metal element is present in an amount equivalent to 1.5 wt% to 20 wt% aluminum based on the weight of the cellulose reactive sizing agent. The composition of claim 22, wherein the salt is present in an amount such that at least one metal element is present in an amount equivalent to 3 wt% to 15 wt% aluminum based on the weight of the cellulose reactive sizing agent. delete delete 24. The composition of claim 23, wherein the salt is present in an amount such that at least one metal element is present in an equivalent amount with 6% to 8% by weight aluminum, based on the weight of the cellulose reactive sizing agent. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete 27. Aqueous paper sizing composition as defined in any of claims 1-4, 10, 12, 13, 20-23 and 26 is added to the cellulosic material. A method of sizing a cellulose-based product, comprising. 70. The method of claim 69, wherein the cellulosic material comprises pulp. The method of claim 69, wherein the cellulosic material comprises the surface of the paper product. delete