JP2009174106A - Rosin based emulsion type sizing agent and paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sizing agent reducing aggregation, and destruction of emulsion caused from interaction with a cationic substance such as calcium etc., while maintaining characteristics of a copolymer composed of styrenes and (meth)acrylate as the main component, such as excellent emulsion stability, storage stability, and to provide a paper obtained by using the same. <P>SOLUTION: The rosin based emulsion type sizing agent includes: a partial or total neutralized product (A') of the copolymer (A) having an anionic functional group which exhibits 0 to 3.0×10<SP>-5</SP>N/cm of difference between maximum and minimum value of surface tension in 1 wt.% aqueous solution of the neutralized product with 0-300° dH of hardness on the neutralized product of partial or total neutralization, 40-90 mg/KOH/g of hydroxyl value and 200-300 mgKOH/g of acid value; and a rosin based resin (B). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a rosin emulsion type sizing agent and paper obtained using the rosin emulsion type sizing agent.

  In recent years, in the paper manufacturing process, (1) increase in papermaking pH due to the use of calcium carbonate, a low-cost filler, (2) increase in used paper ratio, and (3) closed papermaking to reduce papermaking wastewater. It is changing to the situation where the effect of the medicine is hard to express. The same applies to the sizing agent. In particular, the increase in water hardness for papermaking due to an increase in dissolved calcium ions causes aggregation and breakage of the emulsion sizing agent particles, remarkably hinders the dispersion and fixing of the sizing agent to the pulp fiber and reduces the size effect. So far, rosin emulsion type sizing agents have been widely used as sizing agents for paper and paperboard because of their good sizing effect and ease of handling, but due to changes in the papermaking environment, the water hardness for papermaking has changed variously. However, there is a need for a rosin emulsion sizing agent that can provide a stable size effect.

The rosin emulsion sizing agent can be obtained by emulsifying a rosin resin using an emulsifying dispersant or the like. Usually, the emulsifying dispersant is used to stabilize the dispersion of the rosin resin as fine particles. Here, it is known that the polarity of the particle potential is determined by the ionicity of the emulsifying dispersant, but aluminum sulfate, cationized starch, etc., which are inexpensive cationic chemicals generally used in the papermaking process, are pulp. An anionic emulsion sizing agent having a negative particle charge is generally used as the rosin emulsion sizing agent because it functions as a fixing agent for the sizing agent on the fiber.

Various polymer emulsifiers containing an anionic functional group such as a carboxyl group have been proposed so far in order to make the particle potential negative. Specifically, for example, by using an anionic copolymer mainly composed of styrenes- (meth) acrylic acid as an emulsifying dispersant for rosins, emulsion stability, storage stability, or freeze-thaw stability Proposals have been made to improve performance. (Refer to Patent Documents 1 to 3) Although these have improved emulsifiability and stability due to the properties of copolymers based on styrenes- (meth) acrylic acid, they have various changes in water hardness for papermaking. It does not correspond.

As a means for improving the dilution stability of rosin emulsion type sizing agents in hard water, a copolymer based on (meth) acrylamide has been proposed (see Patent Document 4), and a wide papermaking pH range. (Meth) acrylamide copolymer is proposed (see Patent Document 5), but both have emulsifying properties and storage stability, and are anionic with styrenes- (meth) acrylic acid as the main base material. It was inferior to a copolymer.

Styrenes- (meth) acrylic is a combination of styrenes- (meth) acrylic acid-based copolymers and (meth) acrylamide that contributes to improving the stability of diluting hard water. A copolymer obtained by grafting (meth) acrylamide to an acid copolymer (see Patent Document 6), and a copolymer obtained by using 5 to 30 wt% of a (meth) acrylamide monomer in combination with a styrene- (meth) acrylic acid copolymer. A polymer has been proposed as an emulsifying dispersant (see Patent Document 7), but the polymerization reaction is complicated or a combination of specific monomers for polymerizing styrenes and (meth) acrylamide which are basically poorly polymerizable. Is indispensable and neither is enough.

Japanese Patent No. 2135746 Japanese Patent No. 2934803 JP 2001-327848 A Japanese Patent Laid-Open No. 11-286889 Japanese Patent No. 3277841 Japanese Patent No. 3382006 Japanese Patent No. 3928416

As described above, the paper manufacturing environment has been changed in various ways, and the water hardness for papermaking is in the range of 20 to 200 ° dH, varies depending on the papermaking machine, and the papermaking pH also varies. Even under such papermaking conditions, the papermaking system Among them, there is a need for a rosin emulsion type sizing agent that is excellent in dilution dispersion stability, has a stable size effect, and does not generate aggregates. The present invention maintains the characteristics of a copolymer based on styrenes (meth) acrylic acid, which is excellent in emulsion stability and storage stability, while maintaining the characteristics of the emulsion by interaction with a cationic substance such as calcium. An object of the present invention is to provide a sizing agent that can reduce the generation of breakage and agglomerates, and a paper obtained using the sizing agent.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by using a rosin emulsion type sizing agent containing a specific polymer and a rosin resin. Completed the invention.

That is, the present invention relates to a rosin emulsion type sizing agent containing the partially neutralized product or the total neutralized product (A ′) of the following copolymer (A) and the rosin resin (B). The copolymer (A) has a maximum surface tension value when the neutralized product after partial neutralization or total neutralization is a 1% by weight aqueous solution of a neutralized product having a hardness of 0 to 300 ° dH. The difference between the value and the minimum value is in the range of 0 to 3.0 × 10 ⁻⁵ N / cm, the hydroxyl value is 40 to 90 mgKOH / g, and the acid value is 200 to 300 mgKOH / g. It is a polymer. The present invention also relates to a paper obtained using the rosin emulsion sizing agent.

According to the present invention, it is excellent in storage stability because it is excellent in dilution stability into hard water and also in emulsion stability. Furthermore, a rosin emulsion type sizing agent capable of imparting an excellent sizing effect to the resultant paper in a wider papermaking pH range (particularly in the neutral range (pH 6 to 8)) can be provided. In addition, since the rosin emulsion type sizing agent of the present invention has excellent fixability to pulp, the amount of aluminum sulfate and the like used can be reduced. Furthermore, the rosin emulsion type sizing agent of the present invention has a size effect even in the case of high temperature papermaking, when the water hardness is high, in the case of increased wastepaper distribution, and even when contaminants increase due to the papermaking system being closed. Can be kept high. Moreover, it is excellent in stationary stability and storage stability, has a small amount of skin formation, and has good dispersibility in skin water. In addition, because it is also excellent in mechanical stability and low foaming properties, it has little foaming and dirt in the papermaking system, and a sizing agent that has the same or better sizing effect than the conventional sizing agent in the weakly acidic to neutral papermaking system. A sizing paper and a sizing method can be provided.

The rosin emulsion type sizing agent of the present invention has a surface tension value when the neutralized product after partial neutralization or total neutralization is a 1% by weight aqueous solution of a neutralized product having a hardness of 0 to 300 ° dH. The difference between the maximum value and the minimum value is in the range of 0 to 3.0 × 10 ⁻⁵ N / cm, and has an anionic functional group having a hydroxyl value of 40 to 90 mgKOH / g and an acid value of 200 to 300 mgKOH / g Copolymer (A) (hereinafter referred to as component (A)) partially or completely neutralized product (A ′) (hereinafter referred to as component (A ′)) and rosin resin (B) (hereinafter referred to as (B ) Component)).

As the component (A), the maximum and minimum surface tension values when the neutralized product after partial neutralization or total neutralization is a 1% by weight aqueous solution of a neutralized product having a hardness of 0 to 300 ° dH. A copolymer having an anionic functional group having a value difference of 0 to 3.0 × 10 ⁻⁵ N / cm, a hydroxyl value of 40 to 90 mgKOH / g, and an acid value of 200 to 300 mgKOH / g. If it is, it will not specifically limit, A well-known thing can be used. The hardness is a value obtained by converting the amount (milligram) of calcium and / or magnesium contained in 100 g of water into the amount of calcium oxide (CaO), and 10 mg / L is 1 ° dH. The surface tension is a value measured using a Kyowa CBVP surface tension meter A-3 type (manufactured by Kyowa Kagaku Co., Ltd.) taking an appropriate amount of a 1% by weight aqueous solution in a petri dish.

The hydroxyl value is [1 / (average molecular weight of the monomer constituting the component (A)) × (mol% of the hydroxyl group-containing monomer × number of hydroxyl groups in the hydroxyl group-containing monomer) × (KOH formula weight) / 100] × 1000. It is a calculated value, and the acid value is [1 / (average molecular weight of monomers constituting component (A)) × (mol% of carboxylic acid group-containing monomer × number of carboxylic acid groups in carboxylic acid group-containing monomer) × ( KOH formula weight) / 100] × 1000. In addition, the average molecular weight of the monomer which comprises (A) component is the value which totaled what multiplied the molar fraction of the monomer which comprises the molecular weight of each monomer which comprises (A) component. For example, when the component (A) is obtained by copolymerizing three components (A1), (A2), and (A3), the average molecular weight of the monomer constituting the component (A) is (M _A1 x _A1 ) + (M _A2 x _A2 ) + (M _A3 x _A3 ). (M _A1 represents the molecular weight of (A1) monomer, and x _A1 represents the molar fraction of (A1) monomer. M _A2 and M _A3 represent (A2) molecular weight of monomer and (A3) molecular weight of monomer, respectively. When the hydroxyl value of the component (A) is less than 40 mgKOH / g, it is not preferable in terms of dilution stability in hard water, and when the hydroxyl value exceeds 90 mgKOH / g, the emulsifiability and the size effect This is not preferable. In addition, when the acid value of the component (A) is less than 200 mgKOH / g, it is not preferable in terms of emulsifying properties and size effects, and when the acid value exceeds 300 mgKOH / g, the dilution stability to hard water is poor. It is not preferable in terms.

Specifically, the component (A) includes, for example, a hydroxyl group-containing (meth) acrylate (a1) (hereinafter referred to as the (a1) component) and a carboxyl group-containing ethylenically unsaturated monomer (a2) (hereinafter referred to as ( It is obtained by copolymerizing a polymerization component containing a) component) as an essential component.

The component (a1) is not particularly limited as long as it is a (meth) acrylate having a hydroxyl group in the molecule, and known components can be used. Specifically, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol mono (meth) acrylate, (meth) allyl alcohol and hydroxy Examples include ethyl (meth) allyl ether. These may be used alone or in combination of two or more. As the component (a1), hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate having a hydrophobic group in addition to the hydroxyl group are preferable in order to impart appropriate emulsifying properties to the copolymer (A).

The component (a2) is not particularly limited as long as it is an ethylenically unsaturated monomer having a carboxylic acid group in the molecule, and known components can be used. Specific examples include (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride. These may be used alone or in combination of two or more. As the component (a2), (meth) acrylic acid and itaconic acid are preferable from the viewpoint of copolymerization with the component (a1).

The polymerization component includes a radical polymerizable compound (a3) other than the component (a1) and the component (a2) that can be copolymerized with the component (a1) or the component (a2) (hereinafter referred to as component (a3)). ) May be used. Examples of the component (a3) include aromatic monomers, alkyl (meth) acrylates other than the component (a1), carboxylic acid vinyl esters, (meth) acrylsulfonic acids and salts thereof, acrylonitrile, (meth) acrylamide, Etc. Examples of the aromatic monomer include styrene, α-methylstyrene, vinyltoluene and the like. Examples of the alkyl (meth) acrylates other than the component (a1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. Is mentioned. Examples of the carboxylic acid vinyl esters include vinyl acetate and vinyl propionate.

(A) Although the usage-amount of each component used in order to obtain a component is not specifically limited, Usually, (a1) component is about 5-20 mol% (preferably 8-17 mol%), (a2) component 20 It is preferable to be about ˜50 mol% (preferably 25 to 45 mol%). In addition, it is preferable that the usage-amount of (a3) component shall be about 30-75 mol% (preferably 35-50 mol%).

The component (A) can be obtained by radical polymerization of the component (a1) and the component (a2), and if necessary, a polymerization component containing the component (a3). The polymerization method is not particularly limited, and various known methods such as solution polymerization, emulsion polymerization, and suspension polymerization can be employed. In the case of solution polymerization, a solvent such as isopropyl alcohol, ethyl alcohol, or methyl isobutyl ketone can be used. The emulsifier used in the emulsion polymerization method is not particularly limited, and various surfactants such as an anionic surfactant and a nonionic surfactant can be used. Examples of the anionic surfactant include dialkyl sulfosuccinate, alkane sulfonate, α-olefin sulfonate, polyoxyethylene alkyl ether sulfosuccinate, polyoxyethylene styryl phenyl ether sulfosuccinate, naphthalene sulfonate. Formalin condensate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylphenyl ether sulfate, etc. can be exemplified, and nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene Examples thereof include sorbitan fatty acid esters and reactive surfactants obtained by introducing a vinyl group, an allyl group, or a propenyl group into these surfactants. One or more of these surfactants can be appropriately selected and used, and the amount used is usually about 0.1 to 10% by weight based on the amount of all charged monomers. In addition, the polymerization initiator used in the polymerization is not particularly limited, and various types such as persulfates, peroxides, azo compounds, redox initiators can be used, and are known for adjusting the molecular weight. Chain transfer agents such as isopropyl alcohol, carbon tetrachloride, ethylbenzene, isopropylbenzene, cumene, thioglycolic acid ester, alkyl mercaptan, 2,4-diphenyl-4-methyl-1-pentene, and the like can also be used as appropriate.

  Since the molecular weight of the component (A) obtained by polymerization is directly correlated with the dispersibility of the rosin substance (reaction product), the weight average molecular weight (styrene conversion value by gel permeation chromatography) is usually 1,000 to 200,000, preferably 1,000 to 100,000. Setting it to 1,000 or more is preferable because the mechanical stability of the emulsion is improved, and setting it to 200,000 or less is preferable because a desired viscosity can be obtained. The component (A) is usually used as a component (A ′) by using a basic compound and partially neutralizing or completely neutralizing the component (A) so as to be dissolved and dispersed in an aqueous solution. Although it does not specifically limit as a basic compound used for neutralization, For example, amine compounds, such as ammonia, a trimethylamine, a triethylamine, ethanolamine, etc. other than alkali metal compounds, such as sodium hydroxide and potassium hydroxide, can be used. . The neutralization may be performed completely or partially.

Examples of the component (B) used in the present invention include known rosins and rosin esters. As rosins, raw rosin such as gum rosin, wood rosin, tall oil rosin, hydrogenated rosin obtained by hydrogenating raw rosin, disproportionated rosin obtained by disproportionating raw rosin, and raw rosin are polymerized. Polymerized rosin obtained, phenol-modified rosin obtained by modifying raw material rosin with phenols, α, β-unsaturated carboxylic acid-modified rosin obtained by modifying raw material rosin with α, β-unsaturated carboxylic acid, etc. Etc. Examples of the α, β-unsaturated carboxylic acid used for the modification of the α, β-unsaturated carboxylic acid include maleic anhydride, maleic acid, monohydric maleic acid obtained from maleic anhydride and a lower alcohol having about 1 to 4 carbon atoms. Examples thereof include esters or maleic diesters, fumaric acid, N-alkylmaleimides, itaconic acid, itaconic anhydride, acrylic acid and the like. Among these, maleic anhydride, maleic acid, maleic acid monoesters, fumaric acid, itaconic acid, and itaconic anhydride are preferable. The amount of α, β-unsaturated carboxylic acid to be used is usually 1 mol part or less, preferably about 0.05 to 0.75 mol part, particularly preferably 0.10 to 0.00. About 70 mol parts. The modification reaction is usually performed at a temperature of about 150 to 300 ° C. for about 0.5 to 24 hours. In addition, you may perform each operation, such as hydrogenation, disproportionation, and modification | denaturation, combining 2 or more types. When combining two or more types of operations, the order of operations may be determined as appropriate according to the type of resin desired. Various operations such as hydrogenation, disproportionation, and modification may be performed on rosin esters described later.

Rosin esters are obtained by esterifying alcohols and rosins. It does not specifically limit as alcohol, A well-known thing can be used. Specifically, for example, monovalent alcohols such as methanol, ethanol, and propanol, divalent alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and neopentyl glycol, 3 such as glycerin, trimethylolethane, and trimethylolpropane. Valent alcohols, tetravalent alcohols such as pentaerythritol and diglycerin, and hexavalent alcohols such as dipentaerythritol (hereinafter, dihydric or higher alcohols may be referred to as polyhydric alcohols). These alcohols may be used alone or in combination of two or more. The amount of rosins and polyhydric alcohol used is such that the equivalent ratio of the hydroxyl group of the polyhydric alcohol to the carboxyl group of the rosins [—OH (eq) / — COOH (eq)] is usually 0.1 to 1.5. In addition to being able to produce a completely esterified product as a rosin ester, a rosin ester containing unreacted rosins can also be produced. When the equivalent ratio is less than 0.1, the ratio of the rosin ester decreases, and the size effect in the neutral region of the obtained sizing agent may not be sufficiently improved. In addition, when the equivalent ratio exceeds 1.5, a large amount of free hydroxyl groups remain in the rosin ester to be produced, and therefore when used as a sizing agent, the size effect may be reduced due to the residual hydroxyl groups. is there. As rosin esters, rosin glycerin ester and rosin pentaerythritol ester are preferable from the viewpoint of performance, cost, and safety. In addition, rosin esters are usually subjected to dehydration condensation while stirring at a temperature of about 150 to 300 ° C. for about 3 to 40 hours under normal pressure, reduced pressure or increased pressure according to the boiling point of the polyhydric alcohol after charging both. I do. Further, if necessary in the reaction, dehydration condensation can be carried out azeotropically using a solvent such as benzene, toluene and xylene.

When the rosins and rosin esters are mixed and used, the content of the rosin esters is preferably 20 to 90% by weight in the component (B). The content of rosin esters is preferably 20 to 90% by weight because the size effect in the neutral region can be remarkably improved.

  The rosin emulsion type sizing agent of the present invention uses the component (A ′) and the component (B). For example, JP-B 53-4866 (melting and high-pressure emulsification method), JP-B 53-22090 (solvent high-pressure) Emulsification method) or known methods such as JP-A-52-77206 and JP-B-58-4938 (reversal emulsification method).

  In the case of the solvent high-pressure emulsification method, the (A ′) component and water with respect to the (B) component previously dissolved in an organic solvent insoluble in water, and sodium hydroxide, potassium hydroxide, ammonia, lower An alkali substance such as amine is added, and the mixture is emulsified using a homogenizer, a piston type high-pressure emulsifier, an ultrasonic emulsifier or the like, and then the organic solvent is distilled off. The addition time of the copolymer is not particularly limited, and when emulsified with a small amount of alkali or surfactant, there is no problem even after passing through an emulsifier or after distilling off the solvent. A good aqueous emulsion can be obtained.

  When the reversal method is used, the component (B) is usually heated and stirred at about 90 to 160 ° C. to melt, and the aqueous solution (A ′) or the aqueous emulsion and a predetermined amount of hot water are added to the phase. Invert to form an emulsion in which the rosin material is the dispersed phase and water is the continuous phase.

In the solvent high-pressure emulsification and inversion emulsification, the copolymer (A ′) component as a dispersing agent is usually about 1 to 30% by weight in terms of solid content with respect to the entire dispersed phase containing the rosin substance, and preferably 2 The upper limit is preferably 20% by weight. Dispersion becomes favorable by setting it as 1 weight% or more. Moreover, it is not economical to use over 30 weight%. If desired, these obtained emulsions can be diluted with water or alkaline water to adjust the pH of the emulsion.

  In the solvent high-pressure emulsification and inversion emulsification, a surfactant can be added in addition to the copolymer as long as the foamability and the size effect are not adversely affected. As the surfactant, various types used in the emulsion polymerization of the above-mentioned copolymer can be used.

  The obtained rosin emulsion type sizing agent of the present invention usually has a solid content of about 10 to 70% by weight, preferably 30% by weight as the lower limit and preferably 55% by weight as the upper limit. Moreover, the average particle diameter by a laser diffraction / scattering method is about 0.2-0.7 micrometer, and is a uniform aqueous emulsion. The aqueous emulsion has a milky white appearance and usually has a pH of 2.0 to 7.5. The aqueous emulsion is stable at room temperature for at least 6 months and does not cause precipitation. In addition, since it has excellent dilution stability in hard water, it can be sufficiently diluted even in the water of rivers, waterworks, wells, etc., and is well dispersed in the water dispersion of pulp, and the dilution is stable for a long time. It is also extremely low foaming. Furthermore, the mechanical stability is good.

The rosin emulsion type sizing agent obtained by the present invention is a sizing agent solid content 0.164% by weight diluted with hard water of 100 to 300 ° dH, and stored at 25 ° C. for one day. Turbidity measurement of the supernatant part after (McVan made: ANALITE NEPHELOMETER
In MODEL 152), a value of 100 to 5,000 NTU is shown.

  The paper of the present invention is prepared by adding the above-mentioned emulsion sizing agent for papermaking to a water dispersion of pulp together with a fixing agent such as aluminum sulfate and sizing at pH 4 to 8, or a cationic fixing agent in a water dispersion of pulp. And can be produced by a method of making paper at pH 4-8. An excellent sizing effect can be imparted to the resultant paper in a wide papermaking pH range. When using fillers, silicates such as talc, clay and kaolin, inorganic fillers such as titanium dioxide and calcium carbonate, and organic fillers such as urea-formalin resin can be used alone or in combination of two or more. . In this case, the emulsion sizing agent for papermaking is usually used at about 0.05 to 3% by weight (dry weight basis) with respect to the pulp.

Hereinafter, the method of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these. In the examples, unless otherwise indicated, the unit% indicates% by weight.

Production Example 1
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 4.0 g of surfactant (Haitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (total amount of monomers: 1.0) %), Hydroxybutyl acrylate 43.7 g (8.0 mol%), 80% methacrylic acid 158.5 g (38.9 mol%), itaconic acid 19.7 g (4.0 mol%), methallylsulfonic acid 31.7 g (5.3 mol%) of sodium, 140.0 g (35.5 mol%) of styrene, 26.4 g (5.9 mol%) of α-methylstyrene, 11.6 g (2.4 mol%) of butyl acrylate ), 1090.0 g of ion-exchanged water, and 16.0 g of α-methylstyrene dimer (4.0% by weight based on the total amount of monomers) as a chain transfer agent were added, and the mixture was stirred under nitrogen gas bubbling while stirring. The temperature was raised to 0 ° C. As a polymerization initiator, 16.0 g of ammonium persulfate (APS) (based on the total amount of monomers of 4.0% by weight) was added, and the temperature was raised to 90 ° C. and held for 100 minutes. Then, ammonium persulfate (APS) 4 was used as a catalyst for post-polymerization. 0.0 g (1.0% by weight of the total amount of monomers) was further added, and the mixture was further maintained at 90 ° C. for 60 minutes. Next, 146.5 g of a 48% aqueous sodium hydroxide solution (99 mol% neutralization of carboxylic acid groups of methacrylic acid and itaconic acid) was added, methacrylic acid and itaconic acid were neutralized, and ion exchanged water was added to obtain a solid content of 25 A copolymer solution having a viscosity of 53%, a viscosity of 53 mPa · s, a pH of 9.4, a hydroxyl value of 42.5 mgKOH / g, and an acid value of 249.1 mgKOH / g was produced. The viscosity was measured using a B-type viscometer, and the pH was measured using pH METER F-14 (manufactured by HORIBA) at 25 ° C. (hereinafter, the viscosity measurement conditions are the same). The hydroxyl value is [1 / (average molecular weight of the monomer constituting the component (A)) × (mol% of the hydroxyl group-containing monomer × number of hydroxyl groups in the hydroxyl group-containing monomer) × (KOH formula weight) / 100] × 1000. The acid value is calculated by the following formula: [1 / (average molecular weight of the monomer constituting the component (A)) × (mol% of the carboxylic acid group-containing monomer × number of carboxylic acid groups in the carboxylic acid group-containing monomer) × It is a value calculated by (formula amount of KOH) / 100] × 1000. This copolymer solution (Production Example 1) was used as an emulsifying dispersant as it was.

Production Examples 2-7 and 10-11
In Production Example 1, the same method was used except that the composition of each monomer was changed as shown in Table 1. Production Examples 2 to 7 and 11 had a solid content of 25%, and Production Example 10 had a solid content of 22%. An emulsifying dispersant as a copolymer solution was obtained. For Production Example 6 and Production Example 10, a 48% aqueous potassium hydroxide solution was used to neutralize the carboxylic acid groups of methacrylic acid and itaconic acid.

Production Examples 8-9
In Production Example 1, the composition of each monomer was changed as shown in Table 1, and n-dodecyl mercaptan (as a total monomer amount: 2.0% by weight) as a chain transfer agent and the amount of ammonium persulfate (APS) as an initiator were compared with each other. Except for the total amount of monomers, 5.0% by weight at the time of pre-polymerization and 2.0% by weight at the time of the post-polymerization, the same method was used. Production Example 8 had a solid content of 25% and Production Example 9 had a solid content of 22%. An emulsifying dispersant as a copolymer solution was obtained. The neutralizing agent is as shown in Table 1.

Production Example 12
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, acrylamide 205.0 g (66.0 mol%), butyl acrylate 44.8 g (8.0 mol%), itaconic acid 136. 4 g (24.0 mol%), sodium methallylsulfonate 13.8 g (2.0 mol%), ion-exchanged water 630.5 g, isopropyl alcohol 548.1 g, n-dodecyl mercaptan 2.4 g as a chain transfer agent (Total monomer amount 0.6% by weight) was charged, and this mixture was stirred and heated to 50 ° C. under nitrogen gas bubbling. As a polymerization initiator, 8.8 g of ammonium persulfate (APS) (based on the total amount of monomers of 2.2% by weight) was added, and the temperature was raised to 80 ° C. and held for 3 hours. Next, isopropyl alcohol was distilled off, and ion-exchanged water was added thereto to obtain a copolymer solution having a solid content of 25.3%, a viscosity of 1200 mPa · s, a pH of 4.3, a hydroxyl value of 0 mgKOH / g, and an acid value of 294.1 mgKOH / g. Production Example 12) was produced.

Production Example 13
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 4.0 g of surfactant (Haitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (total amount of monomers: 1.0) Weight%), acrylamide 52.0 g (17.7 mol%), methacrylic acid 159.8 g (35.9 mol%), itaconic acid 19.9 g (3.7 mol%), sodium methallylsulfonate 32.1 g (4.9 mol%), styrene 131.0 g (30.4 mol%), α-methylstyrene 24.9 g (5.1 mol%), butyl acrylate 12.2 g (2.3 mol%), ion exchange 1090.0 g of water and 16.0 g of α-methylstyrene dimer (4.0% by weight of the total monomer) were charged as a chain transfer agent, and the mixture was heated to 60 ° C. under nitrogen gas bubbling while stirring. As a polymerization initiator, 16.0 g of ammonium persulfate (APS) (based on the total amount of monomers of 4.0% by weight) was added, and the temperature was raised to 90 ° C. and held for 100 minutes. Then, ammonium persulfate (APS) 4 was used as a catalyst for post-polymerization. Further, 0.0 g (1.0% by weight of the total amount of monomers) was added, and the mixture was further maintained at 90 ° C. for 60 minutes. Next, 149.2 g of a 48% aqueous sodium hydroxide solution (neutralization of 99 mol% of carboxylic acid groups of methacrylic acid and itaconic acid) was added, methacrylic acid and itaconic acid were neutralized, and ion exchanged water was added to obtain a solid content of 25 A copolymer solution having a viscosity of 110%, a viscosity of 110 mPa · s, a pH of 9.2, a hydroxyl value of 0 mgKOH / g, and an acid value of 251.2 mgKOH / g was produced. The copolymer solution (Production Example 13) was used as it was as an emulsifying dispersant.

表中、ＨＰＡは、ヒドロキシプロピルアクリレート、ＨＢＡは、ヒドロキシブチルアクリレート、ＧＭＡは、グリセリンモノアクリレート、ＭＡＡは、メタクリル酸、ＩＡは、イタコン酸、Ｓｔは、スチレン、αＭｅＳｔは、アルファメチルスチレン、ＭＭＡは、メタクリル酸メチル、ＢＡは、アクリル酸ブチル、ＢＭＡは、メタクリル酸ブチル、ＳＭＡＳは、メタリルスルホン酸ナトリウム、ＡＭは、アクリルアミドを表す。また、中和の欄の種は中和の際に用いたアルカリ化合物の種類を、率は、共重合体が有する酸性基のモルに対し、使用したアルカリ成分のモルの割合［｛（使用したアルカリ成分のモル数）／（共重合体が有する酸性基のモル数）｝×１００で表される値］を表す。

In the table, HPA is hydroxypropyl acrylate, HBA is hydroxybutyl acrylate, GMA is glycerol monoacrylate, MAA is methacrylic acid, IA is itaconic acid, St is styrene, αMeSt is alphamethylstyrene, MMA is , Methyl methacrylate, BA is butyl acrylate, BMA is butyl methacrylate, SMAS is sodium methallyl sulfonate, and AM is acrylamide. Further, the type in the column of neutralization is the type of alkali compound used in the neutralization, and the rate is the ratio of the molar amount of the alkaline component used to the molar amount of the acidic group of the copolymer [{(used (Number of moles of alkali component) / (number of moles of acidic group of copolymer)} × 100].

Table 2 shows the physical properties and the like of the copolymer (A) obtained in Production Examples 1 to 13 and the neutralized product (A ′) thereof. The hydroxyl value and acid value are values calculated from the monomer components of the copolymer (A) before neutralization, and the solid content, viscosity, pH, and surface tension are as neutralized product (A ′). It is measured.

表中、水酸基価の単位は（ｍｇＫＯＨ／ｇ）、酸価の単位は（ｍｇＫＯＨ／ｇ）、固形分の単位は（重量％）、表面張力の単位は（Ｎ／ｃｍ（×１０^−５））である。

In the table, the unit of hydroxyl value is (mgKOH / g), the unit of acid value is (mgKOH / g), the unit of solid content is (% by weight), and the unit of surface tension is (N / cm (× 10 ⁻⁵ )). ).

The following surface tension test was performed on the copolymer (A ′) obtained in the above production example.
(Surface tension test)
Using a calcium chloride aqueous solution, a 1% by weight aqueous solution of the copolymer (A ′) obtained in the above production example having 0 ° dH, 100 ° dH, 200 ° dH, and 300 ° dH was prepared.
An appropriate amount of each aqueous solution was taken in a petri dish, and the surface tension value was measured using a Kyowa CBVP surface tension meter A-3 type (manufactured by Kyowa Chemical Co., Ltd.) (unit: N / cm (× 10 ⁻⁵ )). Is shown in Table 2.

Production Example 14 (Production Example of Gum Rosin Fumaric Acid Reinforcement (1))
47.0 g of fumaric acid was added to 675.0 g of gum rosin having an acid value of 170 mg KOH / g in a molten state at 160 ° C., and heated and heated at 190 to 220 ° C. for 2 hours to obtain a fumaric acid-reinforced product of gum rosin (1). It was. The addition rate of fumaric acid in this strengthened product was 7%, and the acid value was 205 mgKOH / g.

Production Example 15 (Production Example of Rosin Esterified Compound (2))
In a flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a water separator and a condenser, 664.2 g of gum rosin having an acid value of 170 and 55.6 g of glycerin (feed molar ratio OH / COOH = 0.90) and oxidation 1.0 g NOCLACK 300 (manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL) as an inhibitor and 0.1 g paratoluenesulfonic acid as a catalyst were heated to 270 ° C. in a nitrogen stream, reacted at the same temperature for 15 hours under stirring, and acid A rosin esterified product (2) having a value of 16 mgKOH / g was obtained.

Example 1
240 g of the fumaric acid-reinforced product of gum rosin (1) obtained in Production Example 14 and 60 g of the rosin esterified product (2) obtained in Production Example 15 were heated and melted to about 160 ° C. and stirred in Production Example 1. The obtained aqueous copolymer solution was added dropwise and mixed in such an amount that the total solid content contained in the aqueous copolymer solution was 19.5 g to obtain a W / O form. After making it an O / W emulsion, it was cooled to room temperature. The emulsion obtained using the copolymer solution (Production Example 1) had a solid content concentration of 50.3%, an emulsion viscosity of 30 mPa · s, and an average particle size of 0.49 μm. Table 3 shows the physical properties of each emulsion when each copolymer solution was used. The viscosity was measured at 25 ° C. using a B-type viscometer. (Hereafter, the viscosity measurement conditions were the same). The average particle size was measured with a particle size measuring apparatus LASER DIFFRACTION PARTICLE SIZE ANALYZER SALD-2000J (manufactured by SHIMADZU) by laser diffraction / scattering method (hereinafter, the measurement conditions of the particle size were the same).

Examples 2-6, Example 8, Comparative Example 3, Comparative Example 6
A rosin emulsion type sizing agent was prepared in the same manner except that the aqueous copolymer solution obtained in Production Example 1 used in Example 1 was changed as shown in Table 3.

Example 7
The mixture of the fumaric acid fortified product of gum rosin (1) obtained in Production Example 14 and the rosin esterified product (2) obtained in Production Example 15 which was heated and melted at about 160 ° C. was added to the co-polymer obtained in Production Example 6. A rosin emulsion type sizing agent having a solid content concentration of 50% was obtained in the same manner as in Example 1 except that the aqueous solution was dropped and mixed so that the total solid content contained in the aqueous copolymer solution was 18.0 g. .

Comparative Example 1
The mixture of the fumaric acid fortified product (1) of gum rosin obtained in Production Example 14 heated and melted at about 160 ° C. and the rosin esterified product (2) obtained in Production Example 15 was added to the copolymer obtained in Production Example 8. A rosin emulsion type sizing agent having a solid content concentration of 50% was obtained in the same manner as in Example 1 except that the combined aqueous solution was dropped and mixed so that the total solid content in the aqueous copolymer solution was 21.0 g. .

Comparative Examples 2 and 4
A rosin emulsion type sizing agent was prepared in the same manner except that the aqueous copolymer solution obtained in Production Example 8 used in Comparative Example 1 was changed as shown in Table 3.

Comparative Example 5
The mixture of the gum rosin fumaric acid-reinforced product (1) obtained in Production Example 14 and melted at about 160 ° C. and the rosin esterified product (2) obtained in Production Example 15 was added to the co-polymer obtained in Production Example 12. A rosin emulsion type sizing agent having a solid content concentration of 50% was obtained in the same manner except that the aqueous solution was dropped and mixed so that the total solid content in the aqueous copolymer solution was 25.5 g.

Properties of the rosin emulsion type sizing agents obtained in Examples and Comparative Examples are shown in Table 3.
The following experiment was conducted for each rosin emulsion type sizing agent. The results are shown in Table 3 and Table 4.

Mechanical Stability Test 50 g of the rosin emulsion type sizing agent obtained in Examples and Comparative Examples was placed in a test container, and a Marlon stability test was performed for 5 minutes at a temperature of 25 ° C., a load of 10 kg, and a rotation speed of 800 rpm. The produced agglomerates were filtered with a 350 mesh wire mesh, and the amount of precipitation with respect to the total solid content was measured and expressed as a percentage. The results are shown in Table 3. The equipment used is MARON (1000 rpm) (manufactured by Shinsei Sangyo Co., Ltd.).

100g of rosin emulsion type sizing agents obtained in the static stability test examples and comparative examples are put in a mayonnaise bottle, left to stand at room temperature for 2 months, and then filtered through a 350 mesh wire net to determine the amount of filtration residue relative to the total solid content. Measured (ppm). The results are shown in Table 3.

表中、使用量の単位は（固形分重量％）、固形分の単位は（重量％）、粘度の単位は（ｍＰａ・ｓ）、粒子径の単位は（μｍ）、機械安定性の単位は（％）、静置安定性の単位は（ｐｐｍ）である。

In the table, the amount used is (solid weight%), the solid content is (wt%), the viscosity is (mPa · s), the particle size is (μm), and the mechanical stability is (%), The unit of stationary stability is (ppm).

Each rosin emulsion type sizing solution obtained in the turbidity measurement test examples and comparative examples was solidified with a rosin emulsion sizing agent solid solution with an aqueous calcium chloride solution having a hardness of 0 ° dH, 100 ° dH, 200 ° dH, and 300 ° dH. Was diluted to 0.164% by weight and allowed to stand at room temperature for 24 hours, and then the turbidity (NTU) of the supernatant of the diluted solution was measured using a product made by McVan: ANALITE NEPHELOMETER MODEL 152. The results are shown in Table 4.

Hand-drawn test cardboard waste paper (containing 12% ash) was added to tap water with a pulp concentration of 2.0% and beaten to 500 ml Canadian Standard Freeness using a beater.
The beaten pulp slurry was further diluted with tap water to adjust the pulp concentration to 1.0%.
After adding a 1.0% sulfuric acid band to the pulp slurry (based on the absolute dry weight), Examples and Comparative Examples so that the solid content of the sizing agent is 0.6% relative to the pulp (based on the absolute dry weight). After adding the rosin emulsion type sizing agent (added to each of calcium chloride aqueous solutions of 100 ° dH, 200 ° dH, and 300 ° dH and stirred for a certain period of time), a paper machine (Tappi Standard Sheet Machine) was prepared. (Round type)), the paper was made to have a basis weight of 110 g / m ² . The papermaking pH at this time was 6.2. The hand-wetted wet paper was dehydrated with a roll press machine under conditions of a linear pressure of 5.5 kg / cm and a feed rate of 2 m / min. The wet paper was dried at 80 ° C. for 150 seconds using a rotary dryer. The obtained test paper was conditioned for 24 hours in a constant temperature and humidity (23 ° C., 50% relative humidity) environment, and then the Cobb water absorption was measured. The Cobb water absorption measurement method conforms to JIS-P8140. The results are shown in Table 4.

Foamability test Each rosin emulsion type sizing solution prepared in the above Examples and Comparative Examples was diluted to 25% by weight with an aqueous calcium chloride solution having a hardness of 100 ° dH, 200 ° dH, and 300 ° dH, and 40 g in a mayonnaise bottle. After measuring the liquid level, it was shaken vigorously and allowed to stand for 1 minute. The height of the liquid level after standing was measured, and foamability (%) was calculated by the following formula. The results are shown in Table 4. (Foaming property) = [(Liquid level after standing) / (Liquid level before stirring)] × 100

In all of the evaluation examples, there is no problem in the stationary stability (skinning amount, sedimentation of solid particles in the emulsion) even at a solid content concentration of 50%, and the emulsion viscosity is 50 mPa · s or less, and there is no practical problem. there were. However, Comparative Evaluation Examples 1 to 6 have problems in stationary stability and size performance. In particular, in Comparative Evaluation Example 5 where the emulsifying and dispersing power is insufficient, the average particle diameter by the laser diffraction / scattering method exceeds 2 μm, The stationary stability and size performance were extremely inferior. On the other hand, Comparative Evaluation Example 6 has a sufficient emulsifying and dispersing power, but the emulsion viscosity is as high as 170 mPa · s (solid content concentration 50%), and it is easy to cause skinning and is inferior in static stability. It is thought that problems will occur. In the size performance at each hardness, the evaluation example is superior to the comparative evaluation example, and it is clear that the difference increases as the hardness increases. Further, it is clear that the evaluation example shows low foaming property as compared with the comparative evaluation example also in the foamability of the emulsion.

Claims (7)

A rosin emulsion type sizing agent comprising a partially neutralized product or a total neutralized product (A ′) of the following copolymer (A) and a rosin resin (B).
Copolymer (A): Maximum and minimum surface tension values when the neutralized product after partial neutralization or total neutralization is a 1% by weight aqueous solution of a neutralized product having a hardness of 0 to 300 ° dH. A copolymer having an anionic functional group having a value difference of 0 to 3.0 × 10 ⁻⁵ N / cm, a hydroxyl value of 40 to 90 mgKOH / g, and an acid value of 200 to 300 mgKOH / g. The copolymer (A) is a copolymer of a polymerization component comprising a hydroxyl group-containing (meth) acrylate (a1) and a carboxyl group-containing ethylenically unsaturated monomer (a2) as essential components. Rosin emulsion type sizing agent. Hydroxyl group-containing (meth) acrylates (a1) are hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol mono (meth) acrylate, (meta 3. The rosin emulsion type sizing agent according to claim 2, which is at least one selected from the group consisting of allyl alcohol and hydroxyethyl (meth) allyl ether. The carboxyl group-containing ethylenically unsaturated monomer (a2) is selected from the group consisting of (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride The rosin emulsion sizing agent according to claim 2 or 3, wherein the rosin emulsion sizing agent is at least one. The rosin emulsion type sizing agent according to any one of claims 1 to 4, wherein the rosin emulsion type sizing agent has an average particle size of 0.2 to 0.7 µm as measured by a laser diffraction / scattering method. 6. The turbidity of the supernatant after standing for one day in a 0.164 wt% aqueous solution diluted with hard water having a hardness in the range of 100 to 300 ° dH shows a value of 100 to 5,000 NTU. A rosin emulsion type sizing agent according to claim 1. Paper obtained by using the rosin emulsion type sizing agent according to any one of claims 1 to 6.