JP2920215B1 - Neutral sizing agent for papermaking and paper sizing method using the same - Google Patents

Abstract

Kind Code: A1 The present invention relates to a neutral sizing agent for papermaking and a method for sizing paper using the same, which has excellent sizing effect, hard water dilution stability and temporal stability in a neutral papermaking region of pH 5.5 to 9. It provides a neutral sizing agent. A neutral sizing agent for papermaking comprising a rosin-based substance, an emulsifying dispersant and water, wherein the rosin-based substance is an alkenyl-substituted succinic acid (a), a rosin (b) and a polyhydric alcohol (c). ), And a mixture of an esterification reaction product (A) obtained by heating and a reinforced rosin (B), wherein the emulsifying dispersant is a carboxyl group-containing monomer and / or a salt thereof (21) to 29 mol%. And a monomer mixture containing 48 to 68 mol% of (meth) acrylamide (b), 3 to 10 mol% of a sulfo group-containing monomer and / or a salt thereof (c), and 8 to 13 mol% of a hydrophobic monomer (d). A neutralizing sizing agent for papermaking, comprising an anionic copolymer obtained by polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a neutral sizing agent for papermaking and a method for sizing paper using the same.
It is an object of the present invention to provide a neutral sizing agent for papermaking having excellent sizing effect, hard water dilution stability and aging stability in a neutral papermaking region of H5.5 to H9.

[0002]

2. Description of the Related Art As is well known, in the papermaking industry, an aqueous dispersion of rosin or fortified rosin (α, β-unsaturated acid adduct of rosin) or an alkali metal soap solution is used for water resistance (sizing) of paper. At the same time, if necessary, it is customary to use it together with a cationic or zwitterionic fixing aid polymer.

On the other hand, in recent papermaking technology, calcium carbonate is generally used as a filler for paper or as a pigment for paper coating. When calcium carbonate is used as a filler, the pH at the time of paper making is inevitably 6 or more, and also, when paper using calcium carbonate as a coating pigment is mixed into a papermaking system as waste paper or waste paper, Usually, the pH is 5.5 or more. When calcium carbonate is used as a filler, light (precipitable) calcium carbonate, which has higher alkalinity than heavy calcium carbonate, has recently been selected because of the low friction of the papermaking wire. .

In such a situation, an aqueous dispersion of rosin or fortified rosin or an alkali metal soap solution, which has been widely used in the past, is not effective for sizing paper, and instead, alkyl ketene dimer (AKD) is used. And a neutral sizing agent containing alkenyl succinic anhydride (ASA) or the like as an active ingredient. However, the AKD-based neutral sizing agent may impart slipperiness to paper or lower the toner adhesion of the paper. In addition, papermaking using AKD-based and ASA-based neutral sizing agents The problem of various types of contamination generated in the process has not been completely solved.

Even when used under conditions of pH 5.5 or more, it is effective as a sizing agent which is effective for making the paper water-resistant and which does not cause any disadvantage such as an AKD-based or ASA-based neutral sizing agent. Sizing agent consisting of a dispersant of modified rosin obtained by esterifying rosin with tertiary amino alcohol
No. 161472), rosin or fortified rosin is 3 to
A sizing agent comprising a dispersant of a modified rosin reacted with a tetrahydric alcohol (Japanese Patent Publication No. 3-79480, Japanese Patent Publication No. 6-4954), a resin obtained by mixing a rosin substance with a hydrocarbon resin, alkenyl succinic acids, etc. (Japanese Patent Publication No. 57-5420, JP-A-7-17-1)
No. 89173). However, although the sizing agents using the rosin-based substances disclosed in these publications exhibit a certain effect under the condition of pH 5.5 or more, they are less effective than AKD-based and ASA-based neutral sizing agents. In order to obtain a predetermined sizing effect, the amount of the sizing agent must be increased, so that not only the cost is increased, but also foaming and various stains during the paper making process are increased.

More recently, rosin-based substances containing esters with alcohols and polyhydric alcohols having improved size effect, foaming property and stain trouble have been converted to cationic (meth)
Sizing agent emulsified and dispersed with acrylamide polymer (JP-A-5-125693), sizing agent obtained by emulsifying and dispersing a rosin-based substance with (meth) acrylamide-based polymer (JP-A-8-337997), and rosin such as rosin ester There has been proposed a sizing agent in which a styrene-based (meth) acrylic acid-sulfonic acid-based monomer copolymer is emulsified and dispersed (Japanese Patent Application Laid-Open No. 7-109360). There is still a problem in exhibiting together with the hard water dilution stability and the aging stability which causes the stiffness. In the papermaking industry, excellent sizing effect, hard water dilution stability and aging stability are obtained in the neutral papermaking region of pH 5.5 to 9. There is a strong need for a papermaking neutral sizing agent.

[0007]

SUMMARY OF THE INVENTION The inventors of the present invention have excellent sizing effects in a neutral papermaking region having a pH of 5.5 to 9 without the drawbacks of using the conventional neutral sizing agent for papermaking. The following inventions have been completed as a result of intensive studies as a technical task to provide a neutral sizing agent for papermaking having hard water dilution stability and aging stability and a paper sizing method using the same.

[0008]

That is, the present invention relates to a neutral sizing agent for papermaking comprising a rosin-based substance, an emulsifying dispersant and water, wherein the rosin-based substance is an alkenyl-substituted succinic acid (a), (B) and a mixture of an esterification reaction product (A) obtained by heating and reacting a polyhydric alcohol (c) with a reinforced rosin (B), wherein the emulsifying dispersant is a carboxyl group-containing monomer and / or The salt (a)
21 to 29 mol%, acrylamide and / or methacrylamide (hereinafter, referred to as (meth) acrylamide)
(B) 48 to 68 mol%, a sulfo group-containing monomer and / or
Or a neutralizing agent for papermaking comprising an anionic copolymer obtained by copolymerizing a monomer mixture containing 3 to 10 mol% of a salt (c) and 8 to 13 mol% of a hydrophobic monomer (d); Neutral sizing agent for papermaking with pH 5.5-9
Is a method for sizing paper used in the neutral region.

The alkenyl-substituted succinic acids (a) used in the esterification reaction product (A) in the present invention include internal olefins having 6 to 36 carbon atoms, ethylene oligomers, propylene oligomers and butylene oligomers, and the like. The mixture and maleic anhydride and / or
Alternatively, it can be obtained by an addition reaction with maleic acid. Particularly preferred is an addition reaction product of propylene tetramer having 12 to 16 carbon atoms and / or propylene pentamer and maleic anhydride.

The alkenyl-substituted succinic acids (a) can be produced by a conventional method. For example, maleic anhydride and / or maleic acid are added to the olefins and reacted in an autoclave reactor at 150 to 250 ° C. for 10 to 24 hours. Obtained.

The rosins (b) used in the esterification reaction product (A) in the present invention include gum rosin, tall rosin, wood rosin, hydrogenated rosin, polymerized rosin, (alkyl) phenol-formalin resin-modified rosin, and xylene resin. Various rosins such as a modified rosin, an aldehyde-modified rosin, and a styrene-modified rosin are exemplified.

It is to be noted that rosins obtained by the addition reaction of an α, β-unsaturated carboxylic acid can be used, but in order to obtain the better effect of the present invention, the α, β-unsaturated carboxylic acid adduct is used. It is preferable not to include it.

The esterification reaction product (A) may be produced according to a conventional method, for example, alkenyl-substituted succinic acids (a), rosins (b) and polyhydric alcohols (c).
At 200 to 280 ° C for 10 to 24 hours.

The polyhydric alcohol (c) used in the esterification reaction product (A) in the present invention includes ethylene glycol, propylene glycol, butadiol, hexanediol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, Sorbitol and the like can be mentioned, and these may be used alone or in combination of two or more.

In the esterification reaction product (A), the mixing ratio of the alkenyl-substituted succinic acids (a) and the rosins (b) is (a) :( b) = 1: 99 to 20:80 parts by weight, More preferably, (a) :( b) = 3: 97 to 10:90
Alkenyl-substituted succinic acids (a)
And the ratio of the hydroxyl equivalent of the polyhydric alcohol (c) to the total carboxyl equivalent of the rosins (b) is from 0.2 to 1.
5, more preferably, by heating and reacting at a charge ratio of 0.7 to 1.0.

The reinforced rosin (B) in the present invention is obtained by subjecting the rosin (b) to an addition reaction with an α, β-unsaturated carboxylic acid. Representative α, β-unsaturated carboxylic acids used herein include unsaturated dibasic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, citraconic anhydride, acrylic acid, Examples thereof include unsaturated monobasic acids such as methacrylic acid, and these may be used alone or in combination of two or more. The α, β-unsaturated carboxylic acid to be added is 5 to 20% by weight, more preferably 10 to 17%, based on the rosin (b).

The production of the fortified rosin (B) may be carried out according to a conventional method. For example, an α, β-unsaturated carboxylic acid is reacted with the rosin (b) at 180 to 250 ° C. for 1 to 5 hours. can get.

The mixing ratio of the esterification reaction product (A) and the fortified rosin (B) in the present invention is as follows:
(B) = 10: 90 to 80:20 parts by weight, more preferably (A) :( B) = 30: 70 to 60:40 parts by weight.

In addition to the esterification reaction product (A) and the fortified rosin (B), the effects of the present invention are not impaired.
C ₅ or more aliphatic, it may be used petroleum resins obtained by polymerizing residual olefins aromatic.

The emulsifying dispersant in the present invention comprises a carboxyl group-containing monomer and / or a salt thereof (a) 21 to 29 mol%, (meth) acrylamide (b) 48 to 68 mol%, a sulfo group-containing monomer and / or Salt (c) 3 ~
An anionic copolymer obtained by copolymerizing a monomer mixture containing 10 mol% and 8 to 13 mol% of a hydrophobic monomer (d).

The carboxyl group-containing monomer and / or its salt (a) is used for improving the emulsifying property and for reducing the particle size of the neutralizing sizing agent for papermaking. 21 to 29 mol% of the monomers. If the amount is less than 21 mol%, the emulsifiability deteriorates, so that the particle size of the resulting neutral sizing agent for papermaking increases, and the sizing effect and the stability over time deteriorate. On the other hand, if it exceeds 29 mol%, the foaming property becomes large.

Specific examples of the carboxyl group-containing monomer and / or its salt (a) include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid and / or their potassium salts and sodium salts. Alkali metal salts and ammonium salts, and these may be used alone or in combination of two or more. Among these, acrylic acid, methacrylic acid, and maleic anhydride are more preferable.

(Meth) acrylamide (b) is used for improving the hard water dilution stability of the neutralizing sizing agent for papermaking. The amount of the (meth) acrylamide used is 48 to 68 mol% of the total monomer constituting the emulsifying dispersant, More preferably, 55 to 65 mol%
It is. When the amount is less than 48 mol%, the stability in dilution with hard water deteriorates, and when it exceeds 68%, a carboxyl group-containing monomer and / or a salt thereof (a), a sulfo group-containing monomer and / or a salt thereof which contribute to control of the particle size ( C) The content of the hydrophobic monomer (d) decreases, and the particle size of the neutralizing sizing agent for papermaking increases.

The sulfo group-containing monomer and / or its salt (c) contributes to the hard water dilution stability and emulsifiability of the neutralizing sizing agent for papermaking, and the amount used is 3 to 3 of the total monomers constituting the emulsifying dispersant. 10 mol%. If the amount is less than 3 mol%, the stability in hard water dilution and the emulsifying property are deteriorated. Adversely affect.

Specific examples of the sulfo group-containing monomer and / or its salt (c) include styrene sulfonic acid (salt),
Vinyl sulfonic acid (salt), 2- (meth) acrylamide-2-methylpropane sulfonic acid (salt), sulfoethyl (meth) acrylate (salt), sulfopropyl (meth) acrylate (salt), (meth) allyl sulfone Sulfonic acid (salt) monomers such as acid (salt), sulfate (salt) of hydroxypropyl (meth) acrylate, sulfate (salt) of hydroxyethyl (meth) acrylate, (meth)
Sulfuric ester (salt) monomers such as polyoxyalkylene sulphate (salt) and polyoxyethylene alkylpropenyl ether sulphate (salt) can be used. These may be used alone or in combination of two or more. Among them, styrene sulfonic acid (salt),
2- (meth) acrylamide-2-methylpropanesulfonic acid (salt), sulfoethyl (meth) acrylate (salt)
Is more preferred.

The hydrophobic monomer (d) is used for imparting hydrophobicity to the emulsifying dispersant, and its amount is 8 to 13 mol% of the total monomers constituting the emulsifying dispersant. If it is less than 8 mol% or more than 13 mol%, the emulsifiability becomes poor.

Specific examples of the hydrophobic monomer (d) include:
Ethyl (meth) acrylate, methyl (meth) acrylate, (meth) acrylate having 1 to 20 carbon atoms in the alkyl group such as butyl (meth) acrylate, styrene, α
-Styrenes such as methylstyrene, styrene-based monomers of styrene-based compounds having an alkyl group having 1 to 4 carbon atoms in the aromatic ring of these styrenes, vinyl carboxylate such as vinyl acetate and vinyl propionate, carbon Number 6-2
2, α-olefins, alkyl vinyl ethers having 1 to 22 carbon atoms, vinyl pyrrolidone, and the like. Among these, (meth) acrylic acid esters are particularly preferable in view of emulsifiability.

As the emulsifying and dispersing agent in the present invention, in addition to the above-mentioned constituent monomers, monomers copolymerizable with the above-mentioned constituent monomers can be used as long as the effects of the present invention are not substantially impaired. Examples of the monomer copolymerizable with the constituent monomer include acrylonitrile, a hydroxyl group-containing monomer, and a polyoxyalkylene group-containing monomer.

As a method for producing the anionic copolymer which is an emulsifying dispersant in the present invention, various known methods such as solution polymerization, emulsion polymerization and suspension polymerization can be adopted. Solvents such as methyl ethyl ketone can be used. The emulsifier used in the case of the emulsion polymerization method is not particularly limited, and various surfactants can be used. For example, an alkali metal salt of a reinforced rosin, an alkylbenzene sulfonate, a polyoxyethylene alkylphenyl ether sulfate, an alkylnaphthalene Anionic surfactants such as sulfonates, polyoxyethylene alkyl ether sulfosuccinate monoester salts, polyoxyethylene alkylphenyl ether sulfosuccinate monoester salts, polyoxyethylene mono- and distyrylphenyl ether sulfosuccinate monoester salts, and the like; Oxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene mono- and distyryl phenyl ether, propylene glycol fatty acid ester, fatty acid dieta Ruamido, non-ionic surfactants such as polyoxypropylene polyoxyethylene glycols can be used, use or in combination with these alone or in combination. The amount of use is about 0.5 to 10% by weight based on all charged monomers.

The polymerization initiator used in each of the above polymerization methods is not particularly limited, and various known ones such as persulfates, peroxides, azo compounds and redox initiators can be used, and the molecular weight is controlled. Known chain transfer agents such as isopropyl alcohol, carbon tetrachloride, cumene, thioglycolate, alkyl mercaptan, 2-mercaptoethanol, and 2,4-diphenyl-4-methyl-1
-Pentenes and the like can be used as appropriate.

The molecular weight of the anionic copolymer, which is an emulsifying dispersant in the present invention, is directly correlated with the emulsifying property of a rosin-based material.
000, more preferably 1,000 to 100,000. If it is less than 500, the stability over time of the emulsion will be poor, and if it exceeds 500,000, the product viscosity will be high.

The method for producing the neutral sizing agent for papermaking according to the present invention is not particularly limited.
According to the method described in JP-B-36242, the component (A) and the component (B) are dissolved in a solvent (for example, benzene, toluene, methylene chloride, etc.), and after adding the emulsifying dispersant component, For producing an oil-in-water emulsion through a homogenizer (solvent method);
The components (A) and (B) are melt-mixed according to the method described in JP-A-77209, and the emulsifying / dispersing agent component is added to the mixture to form a water-in-oil emulsion. A method of inverting water to cause a phase transition to an oil-in-water emulsion (phase inversion method), and converting the components (A) and (B) according to the method described in JP-B-53-32380. After melt-mixing and further mixing the emulsifying and dispersing agent components, a method (mechanical method) of producing an oil-in-water emulsion through a homogenizer under high temperature and high pressure is used.

In the solvent method, the phase inversion method, and the mechanical method, a surfactant and an alkali substance such as sodium hydroxide, potassium hydroxide, and ammonia may be added to such an extent that foaming property and size effect are not adversely affected. Examples of the surfactant include various surfactants used at the time of emulsion polymerization of the copolymer.

In the solvent method, the phase inversion method, and the mechanical method, the copolymer serving as a dispersant is usually 1 to 20% by weight, more preferably 5 to 10% by weight on a dry weight basis with respect to a rosin-based substance. % Range. If it is less than 1% by weight, the dispersing power is not sufficient, and if it exceeds 20% by weight, the foaming property becomes large.

The neutralizing agent for papermaking according to the present invention has a pH
When used in a neutral region of 5.5 or more, it exerts an excellent size effect, and also improves the stability of hard water dilution and the stability over time of the dispersion due to the machine stain trouble which is a problem in neutral papermaking, and in particular, In addition, the conventional rosin sizing agent for neutral papermaking provides a satisfactory sizing effect to light calcium carbonate high-filled paper, which cannot be expected to have a sufficient sizing effect, and improves operational stability by preventing various problems.

The neutralizing sizing agent for papermaking according to the present invention can exhibit excellent sizing performance by itself. However, known neutral sizing agents, such as epichlorohydrin modified styrene-dimethylaminoethyl methacrylate copolymer, Alkenyl succinic anhydride, alkyl ketene dimer, fatty acid
It is also possible to use a polyalkylpolyamine condensate modified with epichlorohydrin in combination.

The paper sizing method according to the present invention is characterized in that
An aqueous dispersion of pulp, which is carried out, for example, by adding the neutralizing agent for papermaking according to the invention to the wet end part in the production process of various papers and paperboards in the neutral papermaking area of 5.5 to 9 The neutralizing agent for papermaking according to the present invention is added in an amount of 0.01 to 5% by solid content, more preferably 0.05 to 2% by solid content, based on the dry weight of the pulp.

In the paper making step, a fixing aid and / or an aluminum salt such as aluminum sulfate is used according to a conventional method.

The filler used in the paper sizing method according to the present invention is not particularly limited, and any known filler can be used. In addition, calcium carbonate which cannot be used in the conventional acidic papermaking method is also suitable. Can be used for
There is an advantage that can greatly contribute to a reduction in papermaking price.

As the fixing agent used in the paper sizing method according to the present invention, known fixing agents used for neutral sizing agents such as alkyl ketene dimer and alkenyl succinic anhydride can be used as they are. Epichlorohydrin modified polyamide polyamine resin, epichlorohydrin modified dicyandiamide resin, epichlorohydrin modified styrene-dimethylaminoethyl methacrylate copolymer, Mannich modified polyacrylamide, acrylamide-dimethylaminoethyl methacrylate copolymer, Hoffman polyacrylamide Decomposition products, copolymers of dialkyldiallylammonium chloride and sulfur dioxide and the like can be mentioned.
Also, the sulfuric acid band used in the acidic papermaking method may be used in a small amount so as not to lower the papermaking pH to 5.5 or less.

In the paper sizing method according to the present invention, the pH at the time of papermaking is appropriately determined within the range of 5.5 to 9, and within this range, excellent sizing effect is exhibited without any problem. Outside, the intended effect of the present invention is not sufficient.

The neutralizing sizing agent for paper making according to the present invention includes printing paper such as high-quality paper, medium-quality paper, coated paper, information paper such as PPC paper, foam paper, heat-sensitive paper, pressure-sensitive paper, packaging paper, and cardboard base paper. , White paperboard, gypsum board paper and the like. Furthermore, as well as papermaking of cellulose fibers, cellulose fibers and mineral fibers, such as asbestos, rock wool, and synthetic fibers,
For example, it can be advantageously applied to papermaking of a mixture with polyamide, polyester, polyolefin and the like to produce paper, paperboard, fiberboard and the like.

The neutralizing sizing agent for papermaking of the present invention can also be used as a surface sizing agent. In this case, the neutralizing sizing agent is applied to a wet paper made in advance by a conventional method such as spraying, dipping or coating. I can do it.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention are as follows.

Production of alkenyl-substituted succinic acids (a): A predetermined amount of an olefin oligomer and maleic anhydride are charged into an autoclave reactor, and charged under a nitrogen atmosphere.
After reaction at 0 to 250 ° C for 10 to 24 hours, distillation under reduced pressure was performed to obtain sticky alkenyl-substituted succinic anhydride.

Production of the esterification reaction product (A): A predetermined amount of gum rosin, a mixture of the alkenyl-substituted succinic anhydride and glycerin in a reactor equipped with a stirrer, a thermometer, a distilling tube, and a nitrogen introducing tube. Prepare a fixed amount, 200 under nitrogen flow
To 280 ° C and react at the same temperature for 10 to 24 hours,
An esterification reaction product was obtained.

Production of fortified rosin (B): A prescribed amount of maleic anhydride is gradually added to a prescribed amount of gum rosin in a molten state at about 200 ° C. in a reactor equipped with a stirrer, a thermometer, and a nitrogen inlet tube. 1 to 5 at 180 to 250 ° C under nitrogen stream
An addition reaction was performed for a time to obtain a reinforced rosin.

Production of emulsifying and dispersing agent: Place isopropyl alcohol, soft water, methacrylic acid, 40% acrylamide, isobutyl methacrylate, sodium salt of sulfoethyl methacrylate in a reactor equipped with a stirrer, thermometer, nitrogen inlet tube and condenser. Quantitation, a predetermined amount of the chain transfer agent n-dodecyl mercaptan and 2-mercaptoethanol were added, mixed and stirred, and heated to an internal temperature of 50 ° C under a nitrogen atmosphere.
A predetermined amount of a radical polymerization initiator azobisisobutyronitrile is added, the temperature is raised to 80 ° C., and after keeping the temperature for 5 hours, a predetermined amount of water is added and distillation under reduced pressure is performed to distill off isopropyl alcohol. After the distillation, the mixture was cooled to obtain an aqueous solution of an anionic copolymer.

Production of neutral sizing agent for papermaking: A predetermined amount of the mixed resin of the esterification reaction product (A) and the reinforced rosin (B) obtained here was dissolved by heating at about 150 ° C. and stirred vigorously. Then, a predetermined amount of the emulsifying dispersant (anionic copolymer aqueous solution) obtained here is added and mixed to form a water-in-oil emulsion. After being made into an oil type emulsion, it was cooled to room temperature to obtain a neutral sizing agent for papermaking.

Evaluation of performance of neutral sizing agent for papermaking

(1) Size effect test: A cationized starch was added to a pulp slurry (concentration: 2.5%) (L-BKP, CSF 500 ml) at a solid content of 0.5 based on the absolute dry pulp.
%, Aluminum sulfate is 1.0% in terms of solids with respect to absolutely dry pulp, and the sizing agent is 0.3% in terms of solids with respect to absolutely dry pulp. Light calcium carbonate is equivalent to absolutely dry pulp. On the other hand, 10% in terms of solid content was added, and then bentonite was added in an amount of 0.04% in terms of solid content to absolutely dry pulp, and papermaking was performed using a TAPPI standard sheet machine according to a conventional method. At this time, the pH of the pulp slurry was 7.5. The wet paper is dehydrated under a pressure of 3.5 kg / cm ² for 5 minutes, and then dried with a rotary drier at a temperature of 90 ° C.
After drying for a minute, a paper having a basis weight of 60 g / m ² was obtained. Temperature 2
After humidity control at 0 ° C. and a humidity of 65% for 24 hours, the sizing degree of each formed paper was measured by the JIS P8112 Steicht method.

(2) Hard water dilution stability test: 1 g of an aqueous solution of a sizing agent having a concentration of 5% was added to hard water having a total hardness of 100,000 ppm (adjusted with anhydrous calcium chloride), and the state of dispersion was visually observed. The evaluation criteria were as follows: ○ = no precipitate. Δ = There is a small amount of precipitate. × = There is a large amount of precipitate.

(3) Stability test with time: 50 g of the sizing agent was placed in a 100 cc transparent glass bottle, sealed, and then left for 3 weeks in an electric dryer set at 80 ° C. to observe the presence or absence of a precipitate. The evaluation criteria were as follows: ○ = no precipitate. Δ = There is a small amount of precipitate. × = There is a large amount of precipitate.

(4) Measurement of average particle diameter: The average particle diameter (μm) of the sizing agent was measured with an ultracentrifugal automatic particle size distribution analyzer (CAPA-700: manufactured by Horiba, Ltd.).

[0055]

The neutral sizing agent for papermaking according to the present invention has good fixability to pulp, so that the use of the sizing agent can be reduced.
This has a structure in which the alkenyl-substituted succinic acids having two carboxyl groups (a), the rosins (b) and the esterification reaction product (A) with the polyhydric alcohol (c) are partially polyesterified in the molecule. Therefore, the molecular weight is larger than the mixed resin of the esterification reaction product of rosin and polyhydric alcohol and the alkenyl-substituted succinic acid, and as a result, the optimum size effect is exhibited. The factor is considered to be the size.

In the present invention, since the mixture of the esterification reaction product (A) and the reinforced rosin (B) is emulsified and dispersed in water with an emulsifying dispersant which is an anionic copolymer, the size effect is reduced. Naturally, the hard water dilution stability which causes machine dirt trouble in neutral papermaking can be greatly improved, and the fine particles having an average particle diameter of about 0.50 μm due to the improvement in emulsifying property. Therefore, the stability over time is greatly improved.

[0057]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited to these Examples. In addition, in each example, all parts and% are based on weight unless otherwise specified.

Production of alkenyl-substituted succinic acids (a): [Production Example a-1] In an autoclave reactor, 144 parts of a high-mass polymer (trade name: Nippon Oil Co., Ltd .: propylene oligomer: 15 carbon atoms), anhydrous After 68 parts of maleic acid was charged and reacted at 200 ° C. for 24 hours under a nitrogen atmosphere, vacuum distillation was performed to obtain a sticky alkenyl-substituted succinic anhydride having an acid value of 230.

Production of esterification reaction product (A): [Production Example A-1] 800 parts of gum rosin having an acid value of 170 in a reactor equipped with a stirrer, a thermometer, a distilling tube, and a nitrogen introducing tube. 13 parts of the alkenyl-substituted succinic anhydride obtained in [a-1] and 83 parts of glycerin were charged, and 2 parts were added under a nitrogen stream.
The mixture was heated to 50 ° C. and reacted at the same temperature for 24 hours to obtain an esterification reaction product having an acid value of 10.

[Production Example A-2] In Production Example [A-1], 800 parts of gum rosin having an acid value of 170 were prepared.
26 parts of the alkenyl-substituted succinic anhydride obtained in 1),
An esterification reaction product having an acid value of 11 was obtained in the same manner as in Production Example [A-1] except that glycerin was changed to 86 parts.

[Production Example A-3] In Production Example [A-1], 800 parts of gum rosin having an acid value of 170 were prepared.
1] The alkenyl-substituted succinic anhydride 103 obtained in [1]
Production Example [A-1] except that parts were used and 106 parts of glycerin were used.
In the same manner as in the above, an esterification reaction product having an acid value of 10 was obtained.

[Production Example A-4] In Production Example [A-2], MSP (trade name: Mitsubishi Oil Co., Ltd.) was used in place of the alkenyl-substituted succinic anhydride obtained in Production Example [a-1].
Manufacture: Addition product of a propylene oligomer having 12 carbon atoms and maleic anhydride), and an esterification reaction product having an acid value of 12 was obtained in the same manner as in Production Example [A-2].

[Production Example A-5] In Production Example [A-2], instead of the alkenyl-substituted succinic anhydride obtained in Production Example [a-1], Coropearl Z-100S (trade name:
The esterification reaction product having an acid value of 10 was produced in the same manner as in Production Example [A-2] except that an internal olefin having 16 carbon atoms and an addition reaction product of maleic anhydride were used. Obtained.

Production of Reinforced Rosin (B): [Production Example B-1] Gum rosin 80 in a molten state at about 200 ° C. in a reactor equipped with a stirrer, a thermometer, and a nitrogen inlet tube.
To 0 parts, 128 parts of maleic anhydride was gradually added, and an addition reaction was performed at 200 ° C. for 5 hours under a nitrogen stream to obtain a reinforced rosin having an acid value of 230.

[Production Example B-2] Production Example [B-] except that 96 parts of maleic anhydride was used.
-1] to obtain a reinforced rosin having an acid value of 215.

Production of emulsifying and dispersing agent (C): [Production Example C-1] 150 parts of isopropyl alcohol, 70 parts of soft water, 28 parts of methacrylic acid in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a cooler. 5 parts (29 mol%), 4
0% acrylamide 116.6 parts (57.5 mol%),
16.3 parts (10 mol%) of isobutyl methacrylate,
8.6 parts of sodium sulfoethyl methacrylate sodium salt (3.
5 parts by mole), 1 part of n-dodecylmercaptan and 1.8 parts of 2-mercaptoethanol were stirred and heated to an internal temperature of 50 ° C. under a nitrogen atmosphere, and then 0.5 part of azobisisobutyronitrile was added. After heating to 80 ° C and keeping the temperature for 5 hours,
20 parts were added and distillation under reduced pressure was performed to distill off isopropyl alcohol. After the distillation is completed, the mixture is cooled to a concentration of 35%.
An aqueous solution of an anionic copolymer having a viscosity of 1000 cps was obtained.

[Production Examples C-2 to C-7] Production Examples [C-
1] a carboxyl group-containing monomer, (meth)
The reaction was carried out in the same manner as in Production Example [C-1] except that the composition of acrylamide, a monomer containing a sulfo group, a hydrophobic monomer, isopropyl alcohol and a chain transfer agent was changed as shown in Table 1, and the respective emulsions were emulsified. An anionic copolymer as a dispersant was obtained. Table 1 shows the product properties.

[0068]

[Table 1]

Production of neutral sizing agent for papermaking: [Example 1] A mixed resin of 30 parts of the esterification reaction product of Production Example [A-1] and 70 parts of reinforced rosin of Production Example [B-1] was used. The mixture was dissolved by heating to about 150 ° C., and with vigorous stirring, 8 parts of the emulsifying and dispersing agent of Production Example [C-1] was added and mixed at a solid content to form a water-in-oil emulsion.
And then cooled to room temperature to obtain a neutral sizing agent for papermaking. The properties are shown in Table 2.

[Examples 2 to 11] Except that the proportions and types of the esterification reaction product (A), the reinforced rosin (B) and the emulsifying dispersant (C) in Example 1 were changed as shown in Table 2. In the same manner as in Example 1, the neutralizing agents for papermaking of Examples 2 to 11 were obtained. The properties are shown in Table 2.

[0071]

[Table 2]

Production of Comparative Esterification Reaction Product: [Comparative Production Example D-1] Except that in Preparation Example [A-1], alkenyl-substituted succinic anhydride [Preparation Example a-1] was not used. In the same manner as in Production Example [A-1], acid value 9
An esterification reaction product was obtained.

[Comparative Production Example D-2] An alkenyl-substituted succinic anhydride in Production Example [A-3] [Production Example a-
Except not using [1], an esterification reaction product having an acid value of 8 was obtained in the same manner as in Production Example [A-3].

[Comparative Production Example D-3] An alkenyl-substituted succinic anhydride of Production Example [A-1] was prepared.
1] was used, and an esterification reaction product having an acid value of 9 was obtained in the same manner as in Production Example [A-1] except that 62 parts of pentaerythritol was used instead of glycerin.

Production of Comparative Emulsifying Dispersant: [Comparative Production Examples E1 to 6] Except that the composition of the monomers used, isopropyl alcohol and the chain transfer agent were changed as shown in Table 1 in Production Example [C-1] Is a production example [C
[1] to obtain copolymers as emulsifying and dispersing agents. Table 1 shows the product properties.

Comparative Production Example E-7 A reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a condenser was charged with 174 parts (80 mol%) of 40% acrylamide and 2-acrylamide-2.
11.9 parts (5 mol%) of methylpropanesulfonic acid,
Ethyl acrylate 18.4 parts (15 mol%), lauryl mercaptan 5 parts, polyoxyethylene (n = 9) oleyl ether 2 parts, polyoxyethylene (n = 13) sodium salt of dodecylphenyl ether sulfate 5
Parts, 3 parts of potassium persulfate and 400 parts of ion-exchanged water were mixed, heated and reacted at 80 ° C. for 6 hours to obtain an aqueous solution of a copolymer. Thereafter, the mixture was cooled, 2-acrylamido-2-methylpropanesulfonic acid and an equimolar amount of sodium hydroxide were added at 60 ° C., and the mixture was stirred for 1 hour to obtain an aqueous solution of a copolymer having a solid content of 15%. Table 1 shows the product properties.

[Comparative Production Example E-8] 230 parts of isopropyl alcohol and 137 parts of 40% acrylamide (80 parts) were placed in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a cooler.
Mol%), ammonium salt of polyoxyethylene alkylpropenyl ether sulfate (Aqualon HS-
10: Trade name: Daiichi Kogyo Seiyaku Co., Ltd.) 30.6 parts (4
Mol%), 12 parts (12 mol%) of styrene, and 2.8 parts (4 mol%) of acrylic acid, and stirred under a nitrogen gas atmosphere. Thereafter, 3 parts of azobisisobutyronitrile was added as a polymerization initiator, the temperature was raised to 80 ° C., the temperature was maintained for 4 hours, 1 part of azobisisobutyronitrile was further added, and the temperature was maintained for 3 hours. 150 parts of exchanged water was added to distill off isopropyl alcohol. After the distillation,
After cooling, potassium hydroxide in an equimolar amount to acrylic acid was added at 60 ° C., and the mixture was stirred for 1 hour to obtain an aqueous solution of a copolymer having a solid content of 20%. Table 1 shows the product properties.

[Comparative Production Example E-9] In a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a condenser, 65 parts (63 mol%) of styrene, 30 parts (35 mol%) of methacrylic acid,
2-acrylamide-2-methylpropanesulfonic acid 5
Part (2 mol%), lauryl mercaptan 5 parts, polyoxyethylene (n = 13) sodium salt of dodecyl phenyl ether sulfate 5 parts, polyoxyethylene (n
= 9) oleyl ether 2 parts, potassium persulfate and water 4
Then, emulsion polymerization was carried out at 80 ° C. for 4 hours under a nitrogen stream. Thereafter, the mixture was cooled to 50 ° C., and an equimolar amount of ammonia was added to the anionic monomer, followed by stirring for 1 hour.
An aqueous copolymer solution having a solid content of 20% was obtained. Table 1 shows the product properties.

Comparative Production Example E-10: Stirrer, thermometer,
In a reactor equipped with a reflux condenser and a nitrogen inlet tube, 31.4 parts (20 mol%) of dimethylaminoethyl methacrylate were added.
40% acrylamide 106.6 parts (60 mol%), styrene 20.8 parts (20 mol%), ion-exchanged water 10
0.6 parts, isopropyl alcohol 143.3 parts, n-
0.6 part of dodecyl mercaptan was charged, and the pH was adjusted to 4.5 with a 20% aqueous acetic acid solution. The mixture was heated to 60 ° C. under a nitrogen gas atmosphere while stirring. 2.3 parts of a 5% aqueous solution of ammonium persulfate was added as a polymerization initiator, the temperature was raised to 80 ° C., and the temperature was maintained for 1.5 hours. Then, 0.7 part of a 5% aqueous solution of ammonium persulfate was added. Furthermore,
After holding for 1 hour, 100 parts of ion-exchanged water was added, and isopropyl alcohol was distilled off. After the distillation was completed, ion-exchanged water was added to obtain an aqueous solution having a solid content of 20%. Table 1 shows the product properties.

Production of Comparative Sizing Agents [Comparative Examples 1 to 15] A method similar to that of Example 1 except that the type of the dispersed phase resin composition and the type of the emulsifying dispersant were changed as shown in Table 2. To emulsify and disperse to obtain the respective sizing agents. Table 2 shows the product properties.

[0081]

[Table 2]

[Evaluation of Performance of Sizing Agent for Paper Making] The sizing agents of Examples 1 to 11 and Comparative Examples 1 to 15 were evaluated for performance.

The size effect, hard water dilution stability, temporal stability, and average particle size of the paper-making sizing agents of Examples 1 to 11 and Comparative Examples 1 to 15 were measured in accordance with the above embodiment. . Table 3 shows the results.

[0084]

[Table 3]

[0085]

According to the present invention, as shown in the Examples,
In the neutral papermaking area of 5.5 to 9, excellent sizing effect, hard water dilution stability and stability over time are exhibited as compared with conventional neutralizing agents for papermaking.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-337997 (JP, A) JP-A-9-21090 (JP, A) JP-A-1-203031 (JP, A) JP-A-7-107 189174 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) D21H 11/00-27/42

Claims (8)

(57) [Claims] 1. A neutral sizing agent for papermaking comprising a rosin-based substance, an emulsifying dispersant and water, wherein the rosin-based substance is an alkenyl-substituted succinic acid (a), a rosin (b) and a polyhydric alcohol ( c) a mixture of an esterification reaction product (A) obtained by heat reaction and a reinforced rosin (B), wherein the emulsifying and dispersing agent is a carboxyl group-containing monomer and / or a salt thereof (21 to 29 mol). %, (Meth) acrylamide (b) 48 to 68 mol%, a sulfo group-containing monomer and / or a salt thereof (c) 3 to 10 mol% and a hydrophobic monomer (d) 8 to 13 mol%. A neutralizing sizing agent for papermaking, comprising an anionic copolymer obtained by copolymerization. 2. The neutralizing agent for papermaking according to claim 1, wherein the alkenyl-substituted succinic acid (a) is an addition reaction product of an olefin oligomer having 6 to 36 carbon atoms with maleic anhydride and / or maleic acid. 3. An esterification reaction product (A) containing an alkenyl-substituted succinic acid (a) and a rosin (b) in a ratio of (a) :( b) = 1: 99 to 20:80 parts by weight. The neutralizing agent for papermaking according to claim 1 or 2, which is a reaction product obtained by subjecting the mixture to an esterification reaction of a polyhydric alcohol (c). 4. The esterification reaction product (A) has a ratio of the hydroxyl equivalent of the polyhydric alcohol (c) to the total carboxyl equivalent of the alkenyl-substituted succinic acids (a) and rosins (b) of 0.2 to 0.2. The neutralizing agent for papermaking according to any one of claims 1 to 3, which is a reaction product obtained by a heating reaction at a charging ratio of 1.5. 5. The compounding ratio of the esterification reaction product (A) and the fortified rosin (B) is (A) :( B) = 10: 90-
The neutralizing agent for papermaking according to any one of claims 1 to 4, wherein the content is 80:20 parts by weight. 6. The weight average molecular weight of the anionic copolymer as an emulsifying dispersant is from 500 to 500,000.
5. The papermaking neutral sizing agent according to any one of 5. 7. The paper-forming neutral sizing agent according to claim 1, wherein the content of the emulsifying dispersant is 1 to 20% by weight in terms of solid content based on the rosin-based substance. 8. A method for sizing paper, comprising using the neutralizing agent for papermaking according to claim 1 in a neutral papermaking region having a pH of 5.5 to 9.