JP2017040021A - Rosin-based emulsion sizing agent and paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel sizing agent using a reinforced rosin as an article to be emulsified and making the sizing effects good even with papers with large basis weight.SOLUTION: There is provided a rosin-based emulsion sizing agent by emulsifying reinforced rosin which is an addition reaction article of rosin (b1) and α,β unsaturated dicarboxylic acid (b2) and contains dibasic diterpene carboxylic acid of at least 0.5 wt.% and rosin esters (C) if needed in the presence of polymer dispersant (A) having an ionic functional group by copolymerizing an anionic unsaturated monomer, a hydrophobic unsaturated monomer and chain transferable unsaturated monomer.SELECTED DRAWING: None

Description

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

  The rosin emulsion sizing agent generally refers to an O / W type emulsion sizing agent obtained by emulsifying a rosin substance in the presence of various emulsifiers and water. Paper obtained by making paper under acidic to neutral conditions using a rosin emulsion sizing agent exhibits good sizing properties due to emulsion particles fixed on pulp fibers.

  There are various methods for fixing the emulsion particles to the pulp fibers. For example, an anionic functional group such as a carboxyl group is introduced into a rosin-based material that is to be emulsified, and the anionic functional group and a carboxyl group or a hydroxyl group on cellulose are bonded via a fixing agent (sulfuric acid band or the like). Means for making them known is known.

  As a rosin-based substance into which a carboxyl group is introduced, a so-called reinforced rosin obtained by adding an α, β unsaturated dicarboxylic acid such as maleic acid or fumaric acid to rosin is well known. For example, Patent Documents 1 to 5 disclose rosin emulsion sizing agents obtained by emulsifying reinforced rosin in the presence of a surfactant or various copolymers.

JP-A-62-250297 JP-A-63-120198 Japanese Patent Laid-Open No. 5-125893 JP-A-6-299488 JP-A-8-337997

  By the way, in the wet paper immediately after papermaking, emulsion particles are locally scattered on the pulp fiber. However, an artificial paper excellent in size cannot be obtained only by natural drying of the wet paper. Therefore, (1) the wet paper is heated by a dryer part, (2) the emulsion particles are melted to coat the pulp fibers, and (3) the emulsion particles and the melt thereof are wetted by convection of the evaporated water. By diffusing inside the paper and uniformly distributing it on the pulp fiber, an obtained paper having the desired size can be obtained.

  In this regard, the emulsion sizing agents described in Patent Documents 1 to 5 are such that the reinforced rosin that is an emulsified product has a plurality of carboxyl groups, and both water contained in the wet paper and anionic pulp fibers. Good affinity for. Therefore, it is considered that the emulsion particles easily diffuse inside the wet paper in the dryer part and are more evenly distributed on the pulp fiber.

  Based on this knowledge, as one means for improving the size effect of the rosin-based emulsion sizing agent, it is conceivable to introduce more carboxyl groups into the reinforced rosin that is to be emulsified to increase its acid value.

  However, the strengthened rosin has a higher softening point as the acid value increases. And most of the emulsion particles having the reinforced rosin having a high softening point as the emulsion to be emulsified locally remain on the pulp fiber without being melted even after passing through the dryer part. In this regard, particularly in the case of wet paper having a large basis weight, the heat of the dryer part is difficult to be transmitted to the inside, so that there are more unmelted emulsion particles, making it difficult to obtain a paper having excellent size.

  The main object of the present invention is to provide a rosin-based emulsion sizing agent having reinforced rosin as an emulsified product, which provides a paper with excellent size effect even when applied to a wet paper having a large basis weight. There is to do.

  The present inventor has conceived of using a reinforced rosin that has a softening point equivalent to that of a conventional reinforced rosin but only an increased acid value as a means for solving the above-mentioned problems. Then, the reinforced rosin containing a predetermined amount of the dibasic diterpene carboxylic acid is found to have a softening point equivalent to that of a conventional reinforced rosin and a high acid value, and this is emulsified in the presence of an anionic copolymer. Thus, it has been found that a rosin emulsion sizing agent capable of solving the above-mentioned problems can be obtained.

  That is, the present invention is an addition reaction product of rosin (b1) and α, β unsaturated dicarboxylic acid (b2) in the presence of a copolymer (A) having an anionic functional group, which is a dibasic diterpene. A rosin emulsion sizing agent obtained by emulsifying reinforced rosin (B) containing at least 0.5% by weight of carboxylic acid and, if necessary, rosin ester (C), and obtained using the rosin emulsion sizing agent Related to paper.

  The rosin emulsion sizing agent of the present invention uses a reinforced rosin containing a predetermined amount of dibasic diterpene carboxylic acid as an emulsified product. Good paper is obtained. The rosin emulsion sizing agent is also excellent in dispersion stability and mechanical stability (hereinafter, both stability may be collectively referred to as emulsifying property) and low foaming property. Moreover, the paper (made paper) of the present invention exhibits excellent sizing properties.

  The rosin emulsion sizing agent of the present invention is prepared in the presence of a copolymer (A) having an anionic functional group (hereinafter also referred to as component (A)) in the presence of a predetermined reinforced rosin (B) (hereinafter referred to as ( B) is also a composition obtained by emulsifying rosin esters (C) (hereinafter also referred to as (C) component).

  As the component (A), various known compounds can be used without particular limitation as long as they are a copolymer having an anionic functional group in the molecule and can be used as an emulsifier for a rosin emulsion sizing agent. Examples of the “anionic functional group” include a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof. Examples of the compound (neutralizing agent) used for forming the “salt” include alkali metal compounds such as sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide, Examples thereof include organic amines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, monopropylamine, dipropylamine and tripropylamine, and ammonia (the same applies hereinafter).

  As the component (A), considering the emulsifiability and size effect of the rosin emulsion sizing agent of the present invention, an anionic unsaturated monomer (a1) (hereinafter also referred to as the component (a1)), hydrophobicity Copolymerization using an unsaturated monomer (a2) (hereinafter also referred to as component (a2)) and a chain transferable unsaturated monomer (a3) (hereinafter also referred to as component (a3)) as reaction components Combined salts are preferred.

  The component (a1) is specifically an unsaturated monomer having one polymerizable carbon-carbon double bond and one anionic functional group, and various known ones can be used without particular limitation. The “polymerizable carbon-carbon double bond” includes, for example, a (meth) acryloyl group, a 1-propenyl group, a 2-methyl-1-propenyl group, an isopropenyl group, a vinyl group, and the like (hereinafter the same). .)

  Specific examples of the component (a1) include, for example, a carboxyl group-containing unsaturated monomer or a salt thereof, a sulfonic acid group-containing unsaturated monomer or a salt thereof, and a phosphate group-containing unsaturated monomer or a salt thereof. And at least one selected from the group consisting of, and the like.

  Examples of the carboxyl group-containing unsaturated monomer or salt thereof include α, β unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid and their salts, maleic acid, maleic anhydride, and fumaric acid. And α, β-unsaturated dicarboxylic acids such as itaconic acid, citraconic acid and citraconic anhydride, and salts thereof. Examples of the sulfonic acid group-containing unsaturated monomer or a salt thereof include styrene sulfonic acid, vinyl sulfonic acid, sulfoethyl (meth) acrylate, and salts thereof. Examples of the phosphate group-containing unsaturated monomer or salt thereof include mono [2-hydroxyethyl (meth) acrylate] acid phosphate, mono [2-hydroxypropyl (meth) acrylate] acid phosphate, and mono [ 3-hydroxypropyl (meth) acrylate] acid phosphate, mono [3-chloro-2-hydroxypropyl (meth) acrylate] acid phosphate, (meth) allyl alcohol acid phosphate and mono [2-hydroxyethyl (meth) acrylate] acid Examples thereof include phosphite and salts thereof. Moreover, these can combine 2 or more types.

  As the component (a1), from the viewpoints of copolymerizability with other unsaturated monomers, dispersion stability of the sizing agent of the present invention, size effect, and the like, the carboxyl group-containing unsaturated monomer or a salt thereof And / or a sulfonic acid group-containing unsaturated monomer or a salt thereof, particularly at least one selected from the group consisting of acrylic acid, methacrylic acid and itaconic acid and salts thereof, particularly itaconic acid or a salt thereof. Salts are preferred.

  The component (a2) is specifically an unsaturated monomer having one polymerizable carbon-carbon double bond and one hydrophobic functional group in the molecule, and various known ones are used without particular limitation. it can. The component (a2) being “hydrophobic” means that the solubility of the component in water (g / 100 g of water) is about 0 to 2.5. Examples of the “hydrophobic functional group” include an alkyl group and an aryl group.

  Specific examples of the component (a2) include at least one selected from the group consisting of alkyl (meth) acrylates, styrenes, carboxylic acid vinyl esters, and unsaturated dicarboxylic acid alkyl esters. Examples of the alkyl (meth) acrylates include (meth) acrylic acid alkyl esters having an alkyl group with about 1 to 18 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, normal butyl, isobutyl, tertiary butyl, normal octyl, 2-ethylhexyl, decyl, dodecyl, hexadecyl. Group, octadecyl group, octadecenyl group, docosyl group, cyclopentyl group, cyclohexyl group and the like. Examples of the styrenes include styrene, α-methyl styrene, t-butyl styrene, dimethyl styrene, acetoxy styrene, hydroxy styrene, vinyl toluene, chlorovinyl toluene, and the like. Examples of the carboxylic acid vinyl esters include vinyl acetate, vinyl propionate, and vinyl laurate. Examples of the unsaturated dicarboxylic acid alkyl esters include monoalkyl esters or dialkyl esters of the α, β unsaturated dicarboxylic acids. Among these, from the viewpoint of copolymerization with other unsaturated monomers, emulsifiability of the sizing agent of the present invention, low foaming property, size effect, and the like, the styrenes and / or alkyl (meth) acrylates. The styrenes are particularly preferably styrene and / or α-methylstyrene. Moreover, as this alkyl (meth) acrylate, that whose carbon number of an alkyl group is about 4-8 is suitable, and the said alkyl group is branched or alicyclic especially from a low foaming viewpoint. Good.

  The component (a3) is specifically an unsaturated monomer having one polymerizable carbon-carbon double bond and one chain transfer functional group in the molecule, and various known ones are particularly limited. It can be used without. When the component (a3) is used, the molecular weight of the component (A) can be appropriately controlled by the chain transfer effect.

  Specific examples of the component (a3) include (meth) allylsulfonic acid or a salt thereof and / or N-substituted acrylamide. Specific examples include allyl sulfonic acid and methallyl sulfonic acid, and dimethyl (meth) acrylamide, isopropyl (meth) acrylamide, methylol (meth) acrylamide, diacetone (meth) acrylamide, and acryloylmorpholine. Among these, (meth) allylsulfonic acid or a salt thereof is preferable, and a sodium salt is preferable as the salt.

  As the reaction component of component (A), acrylamides (a4) (hereinafter also referred to as (a4) component), hydroxyl group-containing unsaturated monomer (a5) (hereinafter referred to as component (a5), if necessary. And at least one selected from the group consisting of a crosslinkable unsaturated monomer (a6) (hereinafter also referred to as component (a6)).

  Specific examples of the component (a4) include acrylamide and / or methacrylamide. By using the component (a4), especially the mechanical stability of the sizing agent of the present invention is increased, so that stains after papermaking are reduced, and an obtained paper having an excellent size effect can be obtained.

  The component (a5) is specifically an unsaturated monomer having one polymerizable carbon-carbon double bond and one hydroxyl group, and is used for the same purpose as the component (a4). Specific examples of the component (a5) include hydroxyl group-containing (meth) acrylates and / or hydroxyl group-containing vinyl monomers. Examples of the hydroxyl group-containing (meth) acrylates include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-2-methyl. And propyl (meth) acrylate. Examples of the hydroxyl group-containing vinyl monomers include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, ethylene glycol monoallyl ether, 4-hydroxycyclohexyl vinyl ether, 3-allyloxy-1,2- Examples thereof include propanediol and glycerol α-monoallyl ether. Moreover, these can combine 2 or more types.

  Component (a6) is an unsaturated monomer having at least two polymerizable carbon-carbon double bonds in the molecule. For the purpose of improving the mechanical stability and size effect of the sizing agent of the present invention, A well-known thing can be used without a restriction | limiting in particular. Specifically, for example, divinylbenzene, trivinylbenzene, divinylsulfone, polyethylene glycol diacrylate, propylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, Hexaethylene glycol diacrylate, N, N′-propylene bisacrylamide, diacrylamide dimethyl ether, N, N′-methylene bisacrylamide and the like can be mentioned, and two or more kinds can be combined.

  The reaction component of the component (A) can further contain an unsaturated monomer other than the components (a1) to (a6) (hereinafter also referred to as the component (a7)). Examples of the component (a7) include cationic unsaturated monomers, α-olefins, polyalkylene glycol unsaturated monomers and nitrile monomers, and so-called reactive emulsifiers.

  Specifically, the cationic unsaturated monomer is an unsaturated monomer having one polymerizable carbon-carbon double bond and one cationic functional group in the molecule. Can be used without restrictions. Specific examples thereof include N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminomethyl (meth) acrylate, and N, N-diethylaminoethyl (meth). Acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminomethyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N , N-diethylaminomethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, 3-diethylamino-2- Hi Roxypropyl (meth) acrylate, 3- (N ', N'-dimethylamino-N-methylamino) -2-hydroxypropy (meth) acrylate, 3-dimethylamino-2-hydroxypropyl (meth) Acrylamide, 3-diethylamino-2-hydroxypropyl (meth) acrylamide, 3-allyloxy-2-hydroxypropyldimethylamine, vinylbenzyldimethylamine and 4- (vinylbenzyl) morpholine and their epihalohydrin, methyl halide, benzyl halide and A reaction product with a quaternized product such as methylsulfuric acid can be mentioned, and two or more kinds can be combined.

  Specific examples of the α-olefin include 2,4,4-trimethylpentene-1,3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1-hexene, Octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1-tetracocene, 1-triacontene, cyclohexene, methylcyclohexene, vinylcyclohexane, 4-vinylcyclohexene, cyclopentene and Examples thereof include methylcyclopentene, and two or more kinds can be combined.

  Specific examples of the polyalkylene glycol unsaturated monomer include β-propiolactone, γ-butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone and ε-caprolactone in the component (a5). The lactones are reacted, and two or more can be combined.

  Specific examples of the nitriles include acrylonitrile and / or methacrylonitrile.

  Specific examples of the reactive emulsifier include those having a polymerizable carbon-carbon double bond and an oxyalkylene group having about 1 to 100 repeating units in the molecule. Examples of the oxyalkylene group include an oxyethylene group, an oxypropylene group, an oxyisopropylene group, an oxybutylene group, and a block body thereof. Specific examples of the reactive emulsifier include polyoxyethylene alkyl ether, sulfosuccinic acid ester salt of polyoxyethylene alkyl ether, sulfuric acid ester salt of polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, sulfosuccinic acid of polyoxyethylene phenyl ether. Acid ester salt, polyoxyethylene phenyl ether sulfate ester salt, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether sulfosuccinate ester salt, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene aralkyl phenyl ether , Sulfosuccinic acid ester salt of polyoxyethylene aralkyl phenyl ether, polyoxyethylene aralkyl phenyl ether Sulfate ester salt, polyoxyethylene alkylphenyl ether phosphate salt; polyoxyethylene alkylphenyl ether aliphatic or aromatic carboxylate, acidic phosphoric acid (meth) acrylate ester emulsifier, bis (polyoxyethylene Polycyclic phenyl ether) methacrylate sulfate ammonium salt; methacryloyloxyethyl sulfonate, polyethylene glycol methacrylate and the like having a polymerizable carbon-carbon double bond. In addition, JP-A-63-23725, JP-A-63-240931, JP-A-62-104802, JP-A-4-50204, JP-A-4-53802, JP-A-4-256429 Reactive emulsifiers described in JP-A No. 9-324394, JP-A 2003-293288, JP-A 2010-242280, and the like can also be used. Moreover, these can combine 2 or more types.

  Although the usage-amount of each of (a1) component-(a7) component is not specifically limited, when the emulsifiability of the sizing agent of this invention, a size effect, etc. are considered, normally, all the unsaturated monomers are 100 mol%. In this case, it can be defined as follows depending on whether or not the component (a4) is used. The total mol% of the components used does not exceed 100.

<When (a4) component is not used>
(A1) component: about 15-80 mol%, preferably about 20-70 mol% (a2) component: about 19-80 mol%, preferably about 28-70 mol% (a3) component: 0.01-10 About mol%, preferably about 0.05 to 8 mol% (a4) Component: 0 mol%

In this case, when any one or combination of the component (a5), the component (a6) and the component (a7) is used in combination, the amount of each component used is not particularly limited, but is usually as follows.
(A5) component: about 0 to 20 mol%, preferably about 0.01 to 15 mol% (a6) component: about 0 to 5 mol%, preferably about 0.5 to 3 mol% (a7) component: 0 -10 mol%, preferably 1-5 mol%

<When (a4) component is used>
(A1) component: about 3-30 mol%, preferably about 5-20 mol% (a2) component: about 3-30 mol%, preferably about 5-20 mol% (a3) component: 0.01-10 About mol%, preferably about 0.05-5 mol% (a4) Component: about 60-90 mol%, preferably about 65-85 mol%

In this case, when any one or combination of the component (a5), the component (a6) and the component (a7) is used in combination, the amount of each component used is not particularly limited, but is usually as follows.
Component (a5): about 0 to 10 mol%, preferably about 3.5 to 5 mol% (a6) component: about 0 to 5 mol%, preferably about 0.1 to 3 mol% (a7) Component: 0 -10 mol%, preferably 1-5 mol%

  The component (A) includes, for example, the component (a1), the component (a2) and the component (a3), and the component (a4), the component (a5), the component (a6) and the component (a7) as necessary. It can be obtained by radical polymerization of at least one selected from the group consisting of various known methods. The polymerization method is not particularly limited, and various known methods such as solution polymerization, emulsion polymerization, suspension polymerization, and the like can be employed. The polymerization conditions are not particularly limited, and the reaction temperature is usually about 80 to 180 ° C., and the reaction time is usually about 1 to 10 hours. In the polymerization reaction, various reaction solvents, radical polymerization initiators, chain transfer agents, and surfactants can be used as necessary. Moreover, you may neutralize the carboxyl group derived from the said (a1) component in the obtained copolymer with the said neutralizing agent as needed.

  Specific examples of the reaction solvent include alcohols such as ethyl alcohol and propyl alcohol, lower ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as toluene and benzene, and organic solvents such as ethyl acetate, chloroform and dimethylformamide. Examples thereof include a solvent, water, and a mixed solvent of the organic solvent and water.

  Specific examples of the radical polymerization initiator include inorganic peroxides such as hydrogen peroxide, ammonium persulfate and potassium persulfate, and organic peroxides such as t-butyl peroxybenzoate, dicumyl peroxide and lauryl peroxide. And azo compounds such as 2,2′-azobisisobutyronitrile and dimethyl-2,2′-azobisisobutyrate, etc., and these may be used alone or in combination of two or more. Can be used. In addition, although the usage-amount in particular of this radical polymerization initiator is not restrict | limited, Usually, when the unsaturated monomer which comprises (A) component is 100 weight part, it is about 1-8 weight part.

  Specific examples of the chain transfer agent include oil-soluble chain transfer agents such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, bromotrichloromethane and 2-mercaptobenzothiazole, α-methylstyrene dimer, and the like. Examples include water-soluble chain transfer agents such as ethanethiol, propanethiol, thioglycolic acid, thiomalic acid, dimethyldithiocarbamic acid, isopropyl alcohol, and sodium hypophosphite. These are used alone or in combination of two or more. Can be used. In addition, although the usage-amount of this chain transfer agent is not restrict | limited in particular, Usually, it is about 0-4 weight part when the unsaturated monomer which comprises (A) component is 100 weight part.

  Examples of the surfactant include the reactive emulsifier, an anionic surfactant and / or a nonionic surfactant having no polymerizable carbon-carbon double bond in the molecule. Examples of the anionic surfactant include dialkyl sulfosuccinate, alkane sulfonate, α-olefin sulfonate, polyoxyethylene alkyl ether sulfosuccinate, polyoxyethylene styryl phenyl ether sulfosuccinate, naphthalene. Examples include sulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate ester salt, and polyoxyethylene alkyl phenyl ether sulfate ester salt. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene styryl phenyl ether, and polyoxyethylene sorbitan fatty acid ester. Moreover, these can combine 2 or more types.

  The physical properties of the component (A) thus obtained are not particularly limited, but considering the emulsifying property, handling property, size effect and the like of the sizing agent of the present invention, for example, weight average molecular weight (refers to a polystyrene equivalent value in gel permeation chromatography). ) Is usually about 4,000 to 100,000, preferably 5,000 to 50,000. When the component (A) is obtained as an aqueous solution, the nonvolatile content is usually about 20 to 40% by weight, the viscosity at 25% of the nonvolatile content is about 5 to 2,000 mPa · s / 25 ° C., and the pH is about 4 to 12. It is.

  Examples of the component (A) include those described in Patent Documents 1 to 5, JP-A-2-33393, JP-A-8-05340, JP-A-9-24265, and JP-A-9-24265. Those described in JP-A-10-245795, JP-A-2007-056416, JP-A-2009-174106, and the like can also be used.

    Component (B) is an addition reaction product of rosin (b1) (hereinafter also referred to as component (b1)) and α, β unsaturated dicarboxylic acid (b2) (hereinafter also referred to as component (b2)). And a reinforced rosin containing at least 0.5% by weight of a dibasic diterpene carboxylic acid.

  In the present specification, the “dibasic diterpene carboxylic acid” is a concept encompassing resin acids represented by the following general formulas (I) to (IV). The general formula [I] represents dihydroagatoic acid, the general formula [II] represents olivelic acid, the general formula [III] represents epene dicarboxylic acid, and the general formula [IV] represents pinifolinic acid.

  Since the component (B) contains a predetermined amount of dibasic diterpene carboxylic acid, it exhibits a high acid value while having a softening point equivalent to that of a conventional reinforced rosin that does not contain the dibasic diterpene carboxylic acid. Therefore, when paper making is performed using the sizing agent of the present invention, the emulsion particles are uniformly distributed inside the wet paper after the dryer part, and melt and spread well on the pulp fiber, so that an excellent paper with excellent size can be obtained. it is conceivable that. From this viewpoint, the content of the dibasic diterpene carboxylic acid in the component (B) is preferably about 0.5 to 15% by weight, more preferably about 6 to 11% by weight.

  The content of the dibasic diterpene carboxylic acid in the component (b1) is not particularly limited. However, in consideration of the emulsifiability and size effect of the sizing agent of the present invention, it is usually at least about 0.5% by weight, preferably 5 to 5%. About 17% by weight, more preferably about 8-13% by weight.

  As the component (b1), rosin (b1-1) (hereinafter also referred to as the component (b1-1)) originally containing dibasic diterpenecarboxylic acid in the above content can be used. Specific examples of the rosin include rosins (gum rosin, tall oil rosin, wood rosin, etc.) derived from Pinus merkusii. Merck pine grows in Indonesia and Vietnam, for example, and rosin derived from Indonesian Merck pine is usually about 8-11% by weight of dihydroagatoic acid, and rosin derived from Vietnamese Merck pine Usually contains about 7 to 10% by weight of dihydroagatoic acid. Further, the component (b1-1) may be subjected to at least one treatment selected from the group consisting of purification, disproportionation, hydrogenation, and polymerization as necessary.

  In addition, as the component (b1), dibasic diterpenecarboxylic acid separately prepared for rosin (b1-2) not containing dibasic diterpenecarboxylic acid (hereinafter also referred to as component (b1-2)) is used. In combination, the content can be adjusted so that the content is within the above range (at least about 0.5 wt%, preferably about 5 to 17 wt%, more preferably about 8 to 13 wt%). Examples of the component (b1-2) include rosin derived from Chinese marsh pine and Mao pine, and this is at least one selected from the group consisting of purification, disproportionation, hydrogenation, and polymerization as necessary. It may have been processed. Moreover, the dibasic diterpene carboxylic acid combined with the said rosin can be prepared, for example, according to the method described in JP-A No. 51-131899.

  As the component (b1), rosin (b1-3) (hereinafter also referred to as the component (b1-3)) containing dibasic diterpenecarboxylic acid in an amount of less than 0.5% by weight was separately prepared. A combination of dibasic diterpene carboxylic acids adjusted so that the content is in the above range (at least about 0.5 wt%, preferably about 5 to 17 wt%, more preferably about 8 to 13 wt%). It can also be used. Further, the component (b1-3) may be subjected to at least one treatment selected from the group consisting of purification, disproportionation, hydrogenation, and polymerization as necessary.

  Examples of the component (b2) include the α, β-unsaturated dicarboxylic acid, and at least one selected from the group consisting of maleic acid, maleic anhydride, fumaric acid, and salts thereof is particularly preferable.

  The component (B) can be produced by various known methods. Specifically, for example, the component (b1-1) and the component (b2) are obtained by reacting Diels-Alder in an appropriate reaction vessel at about 190 to 230 ° C. for about 1 to 3 hours. be able to. In addition, a dibasic diterpenecarboxylic acid prepared separately is contained in a product obtained by the Diels-Alder reaction in the same manner as the component (b1-2) and / or the component (b1-3) and the component (b2). You may add so that the quantity may become the said range (at least about 0.5 weight%, Preferably about 5-17 weight%, More preferably, about 8-13 weight%). In addition, although the usage-amount of (b2) component with respect to (b1) component is not specifically limited, Usually, it is about 1-15 weight part with respect to 100 weight part of (b1) component, Preferably it is about 7-12 weight part. is there.

  The physical properties of the component (B) thus obtained are not particularly limited. However, from the viewpoint of emulsifying property and size effect of the sizing agent of the present invention, the softening point is usually about 85 to 140 ° C. and the acid value is about 195 to 320 mgKOH / g. Preferably, the softening point is about 95 to 130 ° C. and the acid value is about 240 to 295 mg KOH / g. Incidentally, conventionally known reinforced rosins that do not contain dibasic diterpene carboxylic acids have a slightly lower acid value of about 175 to 300 mg KOH / g, but the softening point is usually 80 to 135. It is equivalent to about ℃.

  The component (C) is a reaction product of rosin and polyhydric alcohol, and various known ones can be used without particular limitation as long as they are rosin esters that can be used for rosin emulsion sizing agents. The sizing agent of the present invention in combination with the component (C) is suitable not only for papermaking in the acidic region, but also for papermaking in a weakly acidic to neutral region, specifically in the region of pH 6.0 to 7.5.

  As the rosin, various known ones can be used without particular limitation. For example, the component (b1-1), the component (b1-2) and the component (b-3) and their derivatives (purified rosin, polymerized rosin, Disproportionated rosin, hydrogenated rosin, reinforced rosin and (meth) acrylated rosin).

  The polyhydric alcohol is preferably a trihydric alcohol and / or a tetrahydric alcohol. Examples of the former include trimethylolethane, trimethylolpropane, and 3-methylpentane-1,3,5-triol. Includes pentaerythritol and diglycerin.

Component (C) can be produced by various known methods. Specifically, for example, the rosin and the polyhydric alcohol are usually esterified at 200 to 350 ° C. for 6 to 20 hours. The reaction may be performed under normal pressure, reduced pressure, or increased pressure. The amount ratio of rosin and polyhydric alcohol is not particularly limited, but usually the equivalent ratio of the former carboxyl group and the latter hydroxyl group [—OH _(eq) / COOH _(eq) ] is 0.2 to 1. It may be within a range of about 0.5, preferably about 0.4 to 1.2. In the reaction, an esterification catalyst such as para-toluenesulfonic acid or various antioxidants can be used. Moreover, you may implement reaction under nitrogen stream.

  (The physical properties of the component (C) are not particularly limited, but considering the emulsifying property and size effect of the sizing agent of the present invention, the softening point is usually about 80 to 100 ° C., the acid value is about 0 to 25 mgKOH / g, and The hydroxyl value is about 0 to 30 mg KOH / g, preferably the softening point is about 85 to 95 ° C., the acid value is about 10 to 20 mg KOH / g, and the hydroxyl value is about 0 to 10 mg KOH / g.

  The weight ratio [(C) / {(B) + (C)}] used between the component (B) and the component (C) is not particularly limited, but considering the emulsifiability and size effect of the sizing agent of the present invention, Usually, it is about 0 to 0.4, preferably about 0.15 to 0.4. In particular, in consideration of the size effect in papermaking in a weakly acidic to neutral region, specifically, a region having a pH of about 6.0 to 7.5, the used weight ratio is more preferably about 0.15 to 0.3.

  Although the usage-amount of (A) component with respect to (B) component and (C) component is not specifically limited, when the emulsifiability of the sizing agent of this invention, a size effect, etc. are considered, normally (B) component and (C) component When the total amount is 100 parts by weight (in terms of solid content), the amount of component (A) used (in terms of solid content) is usually about 4 to 12 parts by weight, preferably about 5 to 9 parts by weight. .

  The sizing agent of the present invention is obtained by emulsifying the component (B) and, if necessary, the component (C) and the component (D) in the presence of the component (A). The emulsification method is not particularly limited, and various known means can be employed. Specifically, for example, a high-pressure emulsification method (see Japanese Patent Publication No. 53-22090) and an inverse emulsification method (see Japanese Patent Laid-Open No. 58-4938) can be mentioned. In the case of the high pressure emulsification method, the component (B) and, if necessary, the component (C) are dissolved in the organic solvent in advance, and then the component (A), water and the neutralizing agent, and if necessary. The component (D) is added and emulsified using a homogenizer, a piston-type high-pressure emulsifier, an ultrasonic emulsifier or the like, and then the organic solvent is distilled off to obtain the desired emulsion. In the case of the inversion emulsification method, after the component (A), the component (B) and the component (C) are melted under heating as necessary, hot water is added to invert the phase, By adding the component (D), a desired emulsion can be obtained. Moreover, in the case of emulsification, the said surfactant can be used together as needed.

  The physical properties of the emulsion thus obtained are not particularly limited. However, the average primary particle size (measured value of average primary particle size by laser diffraction / scattering method) is usually used from the viewpoints of storage stability, size effect and dispersibility inside the wet paper. The same shall apply hereinafter) is about 0.1 to 1.2 μm. In particular, in consideration of the size effect in papermaking in a weakly acidic to neutral region, specifically, a region having a pH of about 6.0 to 7.5, it is preferably about 0.4 to 0.6 μm. The pH is about 2 to 7.5, and the viscosity (non-volatile content 50%, 25 ° C., measured value of B-type viscometer (rotor No. 1); hereinafter the same) is about 5 to 150 mPa · s. is there.

  In addition, the emulsion includes various additives, for example, paper strength enhancers such as celluloses such as carboxymethyl cellulose, polyvinyl alcohols, polyacrylamides, water-soluble polymers such as sodium alginate, anti-slip agents, preservatives, A rust preventive agent, pH adjuster, antifoaming agent (silicon-based antifoaming agent, etc.), thickener, filler, antioxidant, water-resistant agent, film-forming aid, pigment, dye and the like can be added.

  The paper of the present invention is obtained using the sizing agent of the present invention. Examples of the sizing method include internal sizing, surface sizing, and combinations thereof.

  In the internally added sizing, the sizing agent of the present invention is added to the pulp slurry, and paper is made in the acidic region or neutral region. Moreover, although the usage-amount of the sizing agent of this invention is not specifically limited, Usually, it is the range used as about 0.05 to 3 weight% with respect to the dry weight of a pulp. Moreover, the kind of pulp is not particularly limited, and examples thereof include chemical pulp such as LBKP and NBKP, mechanical pulp such as GP and TMP, and other waste paper pulp. In addition, during the internal sizing, the component (D) can be used as a fixing agent, and aluminum sulfate and / or aluminum hydroxide is particularly preferable. The pH of the pulp slurry can be adjusted with sulfuric acid, sodium hydroxide, or the like. Further, as other neutral sizing agents, for example, epichlorohydrin modified products of styrene-dimethylaminoethyl methacrylate copolymer, alkenyl succinic anhydride, alkyl ketene dimer, epichlorohydrin modified products of fatty acid-polyalkylpolyamine condensate can be used in combination. . Other paper strength agents include, for example, cationized starch, polyamide polyamine resin epichlorohydrin modified, dicyandiamide resin epichlorohydrin modified, styrene-dimethylaminoethyl methacrylate copolymer epichlorohydrin modified, polyacrylamide Mannich modified Products, acrylamide-dimethylaminoethyl methacrylate copolymers, polyacrylamide Hoffman degradation products, copolymers of dialkyldiallylammonium chloride and sulfur dioxide, and the like. Further, fillers such as talc, clay, kaolin, titanium dioxide and calcium carbonate can be added to the pulp slurry.

In surface sizing, the sizing agent of the present invention is diluted to a non-volatile content of about 0.01 to 2% by weight to form a sizing solution, which is applied to a base paper by various known means. The coating means is not particularly limited, and examples thereof include a size press method, a gate roll method, a bar coater method, a calendar method, and a spray method. Moreover, as a size press method, a 2 roll size press coating system and a rod metal ring size press coating system are mentioned, for example. The coating amount of the sizing solution is not limited (solids), in particular, usually, 0.001~2g / ^{m 2} approximately, and preferably from 0.005 to 0.5 / ^{m 2} approximately. Also, the base paper is not particularly limited, and for example, uncoated paper made from wood cellulose fibers can be used. Moreover, what was mentioned above is mentioned as a pulp which comprises a base paper. Further, the base paper may be paper-made using one kind selected from the group consisting of the fixing agent, neutral sizing agent, paper strength agent and filler, and the neutral sizing agent and / or paper. The force agent may be coated on the surface.

The paper of the present invention is used in various products depending on the basis weight. For example, a low to medium basis weight paper of about ²⁰ to 150 g / m ² is used for recording paper such as foam paper, PPC paper, thermal recording base paper and pressure sensitive recording base paper, art paper, cast coated paper and high quality coated paper. It can be used as wrapping paper such as coated paper, kraft paper, pure white roll paper, etc., and paper such as notebook paper, book paper, printing paper, and newsprint paper. Moreover, the high basis weight formed paper of 150 g / m ² or more can be used as, for example, a paperboard such as a Manila ball, a white ball, a chip ball, and a liner.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, naturally the scope of the present invention is not limited by these. In each example, all parts and percentages are based on weight unless otherwise specified.

Moreover, in each example, the weight average molecular weight of (A) component is the value measured by the method defined below.
When component (a4) is not used: Conversion of polystyrene standard material by gel permeation chromatography method (use apparatus: HLC8120GPC manufactured by Tosoh Corporation, column: TSK-GEL SuperHM-N manufactured by Tosoh Corporation, developing solvent tetrahydrofuran) When the value (a4) component is used: Gel permeation chromatography method (use apparatus: HLC8120GPC manufactured by Tosoh Corporation, column: TSK-GEL ALPHA-M manufactured by Tosoh Corporation, developing solvent 0.2M sodium nitrate aqueous solution) Conversion value of polyethylene glycol standard substance by

  Moreover, a viscosity is a measured value in 25 degreeC by Brookfield rotational viscometer VISCOMETER TVK-10 (Corporation | KK Toki Sangyo).

  The pH is a value measured at 25 ° C. using a commercially available measuring machine (product name “pH METER F-14”, manufactured by Horiba, Ltd.).

  The average primary particle size is a value measured by a particle size measurement device (product name “LASER DIFFRATION PARTICLE SIZE ANALYZER SALD-2000J”, manufactured by Shimadzu Corporation) using a laser diffraction / scattering method.

  The content of the dibasic diterpene carboxylic acid in the raw material rosin is a value obtained using a gas chromatography measuring device (product name “HP6890 / 5973”, manufactured by Agilent).

<Production of non-acrylamide type anionic copolymer salt>

Production Example 1
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, 40.00 g of 80% methacrylic acid, 5.00 g of itaconic acid and 0.05 g of sodium styrenesulfonate as the component (a1) (a2 ) Component as methyl methacrylate 0.05 g, butyl acrylate 3.00 g, butyl methacrylate 0.05 g, 2-ethylhexyl acrylate 0.05 g, styrene 32.80 g and α-methylstyrene 6.20 g, (a3) methallylsulfone as component 8.00 g of sodium acid, 13.00 g of 4-hydroxybutyl acrylate as component (a5), 1.0 g of a surfactant (Haitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 300 g of ion-exchanged water, and Charge 4.00 g of α-methylstyrene dimer as a chain transfer agent, With stirring under a gas bubbling it was raised and the reaction system to 60 ° C.. Next, 5.00 g of ammonium persulfate (APS) was added as a polymerization initiator, the temperature was raised to 90 ° C. and held for 100 minutes, then 2.0 g of APS was further added as a catalyst for post-polymerization, and the mixture was held at 90 ° C. for 60 minutes. . Next, 37.1 g of a 48% sodium hydroxide aqueous solution was added to neutralize, and a predetermined amount of ion-exchanged water was added to obtain an aqueous solution of an anionic copolymer salt (A1) having a weight average molecular weight of 15,000. It was. The aqueous solution had a nonvolatile content of 25.1% by weight, a viscosity of 55 mPa · s / 25 ° C., and a pH of 9.5.

<Manufacture of reinforced rosin>
Production Example 2
In the same reaction vessel as in Production Example 1, gum rosin (content of 9.8% by weight of dihydroagatoic acid, hereinafter referred to as ID rosin) derived from Indonesian Merck pine as component (b1-1) at about 160 ° C. By charging 600.0 g of the melt and 42 g of fumaric acid and reacting at 200 ° C. for 2 hours with stirring under a nitrogen stream, the dihydroagatoic acid content was 9.2% by weight and the softening point was 106.1. A reinforced rosin (B1) having an acid value of 240.8 mgKOH / g was obtained.

Comparative production example 1
In the same reaction vessel as in Production Example 1, gum rosin (dibasic diterpenecarboxylic acid content 0% by weight, hereinafter referred to as CN rosin) derived from Chinese Maomatsu as component (b1-2) is about 160 ° C. 600.0 g of fumaric acid and 42 g of fumaric acid were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream, so that the content of dihydroagatoic acid was 0% by weight and the softening point was 105.7 ° C. And reinforced rosin (I) having an acid value of 221.1 mgKOH / g was obtained.

<Manufacture of rosin emulsion sizing agent>
Example 1
In a reaction vessel similar to Production Example 1, 100 g of the reinforced rosin (B1) of Production Example 2 was charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A1) of Production Example 1 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.44 μm, a non-volatile content of 50.2% by weight, a pH of 5.7, and a viscosity of 39 mPa · s / 25 ° C.

Comparative Example 1
In the same reaction vessel as in Production Example 1, 100 g of reinforced rosin (I) obtained in Comparative Production Example 1 was charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A1) of Production Example 1 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.43 μm, a nonvolatile content of 50.2 wt%, a pH of 5.9, and a viscosity of 40 mPa · s / 25 ° C.

<Test 1: Use of L-BKP; acid papermaking and evaluation of steecht size>
To L-BKP, tap water having an amount of 2.0% pulp was added and beaten to 300 ml Canadian Standard Freeness using a beater. Next, the obtained pulp slurry was further diluted with tap water to prepare a slurry having a pulp concentration of 1.0%. Next, the diluted pulp slurry was filled with 16.0% of pulp (absolute dry weight basis, hereinafter the same) filler (a mixture of calcium carbonate and talc), 1.5% sulfate band, and 0.3%. % Commercial cation-modified starch was added to prepare a pH 5.0 pulp slurry. The pH of the papermaking system was adjusted with a sulfuric acid aqueous solution.
Next, the emulsion of Example 1 is added to the pulp slurry so that the emulsion is 0.3% (in terms of solid content), and a paper machine (Tappi Standard Sheet Machine (round shape); hereinafter the same) is used. Paper was made to obtain wet paper. Next, each 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, and dried at 90 ° C. for 360 seconds using a rotary dryer. Next, the basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² is obtained by conditioning the obtained dry paper for 24 hours in a constant temperature and humidity (23 ° C., 50% relative humidity) environment. An obtained paper (test paper) was obtained.
Next, for each test paper, the degree of Steecht sizing was measured according to JIS-P8122. The results are shown in Table 1. In addition, the larger the value of the steecht size, the better.

Also for the sizing agent of Comparative Example 1, in accordance with the above acidic papermaking conditions, an obtained paper (using L-BKP) having a basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² was obtained. Next, for each test paper, the degree of Steecht sizing was measured according to JIS-P8122. The results are shown in Table 1.

<Test 2: Use of waste paper pulp; acid papermaking and Cobb water absorption evaluation>
Corrugated waste paper (containing 12% ash) was added with tap water in an amount that would bring the pulp concentration to 2.0%, and beaten to 400 ml Canadian Standard Freeness using a beater. Subsequently, the obtained pulp slurry was further diluted with tap water to adjust the pulp concentration to 1.0%. Next, a sulfuric acid band with 1.0% to pulp was added to the diluted slurry to prepare a pulp slurry having a pH of 5.0. The pH of the papermaking system was adjusted with a sulfuric acid aqueous solution.
Next, the emulsion of Example 1 was added to the pulp slurry, and paper was made using a paper machine to obtain wet paper. Next, each 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, and dried at 90 ° C. for 360 seconds using a rotary dryer. Next, the basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² is obtained by conditioning the obtained dry paper for 24 hours in a constant temperature and humidity (23 ° C., 50% relative humidity) environment. An obtained paper (test paper) was obtained.
Next, the Cobb water absorption (contact time 1 minute) was measured for each test paper in accordance with JIS-P8140. The results are shown in Table 1. Note that the smaller the value of the Cobb water absorption, the better.

Also for the sizing agent of Comparative Example 1, in accordance with the above acidic papermaking conditions, an obtained paper (test paper) having a basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² was obtained. Next, the Cobb water absorption (contact time 1 minute) was measured for each test paper in accordance with JIS-P8140. The results are shown in Table 1.

<Manufacture of rosin ester>
Production Example 3
In the same reaction vessel as in Production Example 1, 663.2 parts of CN rosin and 55.6 parts of glycerin were charged (equivalent ratio [—OH _(eq) / COOH _(eq) ] = 0.90), and further an antioxidant. As follows: Nocrack 300 (manufactured by Ouchi Shinsei Chemical Co., Ltd.) and 0.1 part of paratoluenesulfonic acid were charged and reacted at 270 ° C. for 15 hours with stirring under a nitrogen stream, A rosin ester (C1) having an acid value of 16 mgKOH / g and a hydroxyl value of 8 mgKOH / g was obtained.

<Preparation of rosin emulsion sizing agent>
Example 2
In a reaction vessel similar to Production Example 1, 80 g of reinforced rosin (B1) of Production Example 2 and 20 g of rosin ester (C1) of Production Example 3 were charged and melted by heating at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A1) of Production Example 1 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.54 μm, a nonvolatile content of 50.2% by weight, a pH of 5.9, and a viscosity of 29 mPa · s / 25 ° C.

Comparative Example 2
In a reaction vessel similar to Production Example 1, 80 g of reinforced rosin (I) of Comparative Production Example 1 and 20 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A1) of Production Example 1 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.54 μm, a non-volatile content of 50.1 wt%, a pH of 5.9, and a viscosity of 28 mPa · s / 25 ° C.

<Test 3: Use of L-BKP; Neutral papermaking and Steech human size evaluation>
To L-BKP, tap water having an amount of 2.0% pulp was added and beaten to 300 ml Canadian Standard Freeness using a beater. Subsequently, the obtained pulp slurry was further diluted with tap water to adjust the pulp concentration to 1.0%. Next, the diluted pulp slurry was filled with a filler (a mixture of calcium carbonate and talc) of 16.0% (based on the absolute dry weight. The same applies hereinafter), 1.5% sulfuric acid band, 0.3% A commercially available cation-modified starch was added to prepare a pulp slurry having a pH of 6.7. The pH of the papermaking system was adjusted with an aqueous sodium hydroxide solution.
Subsequently, the sizing agent of Example 2 was added so that it might become 0.3% with respect to a pulp (solid content conversion), and papermaking was performed using the paper machine, and the wet paper was obtained. Next, each 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, and dried at 90 ° C. for 360 seconds using a rotary dryer. Next, the basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² is obtained by conditioning the obtained dry paper for 24 hours in a constant temperature and humidity (23 ° C., 50% relative humidity) environment. An obtained paper (test paper) was obtained.
Next, for each test paper, the degree of Steecht sizing was measured according to JIS-P8122. The results are shown in Table 2.

Also for the sizing agent of Comparative Example 2, in accordance with the above neutral papermaking conditions, an obtained paper (test paper) having a basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² was obtained. Next, for each test paper, the degree of Steecht sizing was measured according to JIS-P8122. The results are shown in Table 2.

<Test 4: Use of recycled paper pulp; neutral papermaking and Cobb water absorption evaluation>
Corrugated waste paper (containing 12% ash) was added with tap water in an amount that would bring the pulp concentration to 2.0%, and beaten to 400 ml Canadian Standard Freeness using a beater. Subsequently, the obtained pulp slurry was further diluted with tap water to adjust the pulp concentration to 1.0%. Next, a sulfuric acid band with 1.0% to pulp was added to the diluted pulp slurry to prepare a pulp slurry having a pH of 6.7. The pH of the papermaking system was adjusted with an aqueous sodium hydroxide solution.
Next, the sizing agent of Example 2 was added to the pulp slurry, and paper making was performed using a paper machine to obtain wet paper. Next, each 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, and dried at 90 ° C. for 360 seconds using a rotary dryer. Next, the basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² is obtained by conditioning the obtained dry paper for 24 hours in a constant temperature and humidity (23 ° C., 50% relative humidity) environment. An obtained paper (test paper) was obtained.
Next, the Cobb water absorption (contact time 1 minute) was measured for each test paper in accordance with JIS-P8140. The results are shown in Table 2.

Also for the sizing agent of Comparative Example 2, in accordance with the above neutral papermaking conditions, an obtained paper (test paper) having a basis weight of 80 g / m ² , 150 g / m ² , and 300 g / m ² was obtained. Next, the Cobb water absorption (contact time 1 minute) was measured for each test paper in accordance with JIS-P8140. The results are shown in Table 2.

<Production of non-acrylamide type anionic copolymer salt>
Production Example 4
In a reaction container similar to Production Example 1, 55.79 g of 80% methacrylic acid, 0.07 g of itaconic acid and 2.00 g of sodium styrene sulfonate as component (a1), 22.82 g of methyl methacrylate as component (a2), butyl acrylate 0.07 g, 0.07 g of butyl methacrylate, 10.00 g of 2-ethylhexyl acrylate, 9.00 g of styrene and 0.06 g of α-methylstyrene, 0.08 g of sodium methallyl sulfonate as component (a3), as component (a5) 0.07 g of 4-hydroxybutyl acrylate, 1.0 g of a surfactant (Haitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 300 g of ion-exchanged water, and 5.00 g of α-methylstyrene dimer as a chain transfer agent And stir the mixture under nitrogen gas bubbling. To reluctant 60 ° C. was raised and the reaction system. Next, 4.00 g of APS was added, the temperature was raised to 90 ° C., and held for 100 minutes, and then 2.0 g of APS was further added and held at 90 ° C. for 60 minutes. Subsequently, 43.7 g of 48% sodium hydroxide aqueous solution was added, and a predetermined amount of ion-exchanged water was added to obtain an aqueous solution of an anionic copolymer salt (A2) having a weight average molecular weight of 19,000. The aqueous solution had a nonvolatile content of 25.1% by weight, a viscosity of 220 mPa · s / 25 ° C., and a pH of 10.4.

<Manufacture of reinforced rosin>
Production Example 5
A reaction vessel similar to Production Example 1 was charged with 600.0 g of a melt of about 160 ° C. of ID rosin and 42 g of maleic anhydride, and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream, whereby dihydroagato A reinforced rosin (B2) having an acid content of 9.2% by weight, a softening point of 96.7 ° C., and an acid value of 252.4 mgKOH / g was obtained.

Production Example 6
In a reaction vessel similar to Production Example 1, about 160 ° C. of gum rosin (content of dihydroagatoic acid 8.1% by weight, hereinafter referred to as VN rosin) derived from Vietnamese Merck pine as component (b-1). 600.0 g of a molten product and 42 g of maleic anhydride were added and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream, whereby the content of dihydroagatoic acid was 7.6% by weight and the softening point was 96.4 ° C. And reinforced rosin (B3) having an acid value of 251.1 mg KOH / g.

Production Example 7
A reaction vessel similar to Production Example 1 was charged with 200.0 g of a melt of about 160 ° C. of ID rosin, 400.0 g of a melt of about 160 ° C. of CN rosin and 42 g of maleic anhydride, with stirring under a nitrogen stream. By reacting at 200 ° C. for 2 hours, a reinforced rosin (B4) having a dihydroagatoic acid content of 3.3% by weight, a softening point of 96.6 ° C., and an acid value of 240.1 mg KOH / g was obtained.

Production Example 8
A reaction vessel similar to Production Example 1 was charged with 50.0 g of a melt of about 160 ° C. of ID rosin, 550.0 g of a melt of about 160 ° C. of CN rosin and 42 g of maleic anhydride, with stirring under a nitrogen stream. By reacting at 200 ° C. for 2 hours, a reinforced rosin (B5) having a dihydroagatoic acid content of 1.1% by weight, a softening point of 96.6 ° C., and an acid value of 237.0 mgKOH / g was obtained.

Comparative production example 2
In the same reaction vessel as in Production Example 1, 600.0 g of a melt of approximately 160 ° C. of CN rosin and 42 g of maleic anhydride were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream, thereby obtaining dihydroagatoic acid. A reinforced rosin (Ro) having a content of 0 wt%, a softening point of 96.5 ° C., and an acid value of 233.7 mg KOH / g was obtained.

<Preparation of rosin emulsion sizing agent>
Example 3
In a reaction vessel similar to Production Example 1, 75 g of reinforced rosin (B2) of Production Example 5 and 25 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, an aqueous solution 7 g (in terms of solid content) of the anionic copolymer salt (A2) of Production Example 4 is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.58 μm, a non-volatile content of 50.3% by weight, a pH of 6.1, and a viscosity of 55 mPa · s / 25 ° C.

Example 4
In a reaction vessel similar to Production Example 1, 75 g of reinforced rosin (B3) of Production Example 6 and 25 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, an aqueous solution 7 g (in terms of solid content) of the anionic copolymer salt (A2) of Production Example 4 is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.59 μm, a non-volatile content of 50.1%, a pH of 6.0, and a viscosity of 53 mPa · s / 25 ° C.

Example 5
In a reaction vessel similar to Production Example 1, 75 g of reinforced rosin (B4) of Production Example 7 and 25 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, an aqueous solution 7 g (in terms of solid content) of the anionic copolymer salt (A2) of Production Example 4 is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.59 μm, a nonvolatile content of 50.2% by weight, a pH of 6.0, and a viscosity of 55 mPa · s / 25 ° C.

Example 6
In a reaction vessel similar to Production Example 1, 75 g of reinforced rosin (B5) of Production Example 8 and 25 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, an aqueous solution 7 g (in terms of solid content) of the anionic copolymer salt (A2) of Production Example 4 is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.58 μm, a non-volatile content of 50.2% by weight, a pH of 6.1, and a viscosity of 51 mPa · s / 25 ° C.

Comparative Example 3
In a reaction vessel similar to Production Example 1, 75 g of reinforced rosin (Ro) of Comparative Production Example 2 and 25 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, an aqueous solution 7 g (in terms of solid content) of the anionic copolymer salt (A2) of Production Example 4 is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.60 μm, a nonvolatile content of 50.2% by weight, a pH of 6.1, and a viscosity of 54 mPa · s / 25 ° C.

<Neutral papermaking and size test>
Using the sizing agent of Example 3, neutral paper making using L-BKP was carried out according to Test 3 above to obtain a synthetic paper having basis weights of 80 g / m ² , 150 g / m ² , and 300 g / m ² , The degree of sizing human sizing was measured. The results are shown in Table 3.

Similarly, using the sizing agent of Example 3, neutral paper making using waste paper pulp was performed according to Test 4 above, and obtained papers having basis weights of 80 g / m ² , 150 g / m ² , and 300 g / m ² , Each Cobb water absorption (contact time 1 minute) was measured. The results are shown in Table 3.

  Similarly, papers having different basis weights were obtained for the rosin emulsion sizing agents of Examples 4 to 6 and Comparative Example 3, respectively, and the Steecht sizing degree and the Cobb water absorption degree (contact time 1 minute) were measured for each. The results are shown in Table 3.

<Production of non-acrylamide type anionic copolymer salt>
Production Example 9
In a reaction container similar to Production Example 1, 27.50 g of 80% methacrylic acid as component (a1), 28.00 g of methyl methacrylate, 7.00 g of butyl acrylate, 7.00 g of butyl methacrylate, and 14.00 g of styrene as component (a2) , Α-methylstyrene (14.00 g), sodium methallyl sulfonate (8.00 g) as component (a3), ion-exchanged water (300 g), and normal dodecyl mercaptan (1.70 g) as a chain transfer agent were added, and the mixture was bubbled with nitrogen gas. The reaction system was heated to 60 ° C. with stirring. Next, 5.00 g of APS was added, the temperature was raised to 90 ° C. and held for 100 minutes, and then 2.0 g of APS was further added and held at 90 ° C. for 60 minutes. Subsequently, 21.3 g of 48% sodium hydroxide aqueous solution was added, and a predetermined amount of ion-exchanged water was added to obtain an aqueous solution of an anionic copolymer salt (A3) having a weight average molecular weight of 11,000. The aqueous solution had a nonvolatile content of 25.3% by weight, a viscosity of 25 mPa · s / 25 ° C., and a pH of 9.1.

<Preparation of rosin emulsion sizing agent>
Example 7
In a reaction vessel similar to Production Example 1, 80 g of reinforced rosin (B1) of Production Example 2 and 20 g of rosin ester (C1) of Production Example 3 were charged and melted by heating at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A3) of Production Example 9 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.55 μm, a nonvolatile content of 50.2 wt%, a pH of 5.9, and a viscosity of 25 mPa · s / 25 ° C.

Comparative Example 4
In a reaction vessel similar to Production Example 1, 80 g of reinforced rosin (I) of Comparative Production Example 1 and 20 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A3) of Production Example 9 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.54 μm, a nonvolatile content of 50.2% by weight, a pH of 6.0, and a viscosity of 24 mPa · s / 25 ° C.

<Neutral papermaking and size test>
Using the rosin-based emulsion sizing agent of Example 7, neutral papermaking using L-BKP was performed according to the above test 3, and the basis weight was 80 g / m ² , 150 g / m ² , and 300 g / m ² . Then, the degree of sizing of each adult paper was measured. The results are shown in Table 4.

Similarly, using the rosin-based emulsion sizing agent of Example 7, neutral paper making using waste paper pulp was performed according to Test 4 above, and the basis weight was 80 g / m ² , 150 g / m ² , and 300 g / m ² . Each Cobb water absorption (contact time 1 minute) was measured. The results are shown in Table 4.

  Similarly, papers having different basis weights were also obtained for the rosin emulsion sizing agent of Comparative Example 4, and for each of them, the Steecht sizing degree and the Cobb water absorption degree (contact time 1 minute) were measured. The results are shown in Table 4.

<Production of acrylamide-based anionic copolymer salt>
Production Example 10
In a reaction vessel similar to Production Example 1, 23.60 g of itaconic acid and 0.05 g of sodium styrenesulfonate as component (a1), 5.90 g of 2-ethylhexyl acrylate and 15.30 g of cyclohexyl methacrylate as component (a2), (a3 ) 1.70 g of sodium methallylsulfonate as component, 53.50 g of acrylamide as component (a4), 220 g of ion-exchanged water, 250 g of isopropyl alcohol, and 0.50 g of 2-mercaptoethanol as a chain transfer agent. The reaction system was heated to 50 ° C. under nitrogen gas bubbling with stirring. Next, 2.20 g of APS was added, the temperature was raised to 80 ° C., and held for 180 minutes. Subsequently, isopropyl alcohol was distilled off by blowing water vapor, and a predetermined amount of ion-exchanged water was added to obtain an aqueous solution of an anionic copolymer salt (A4) having a weight average molecular weight of 12,000. The aqueous solution had a nonvolatile content of 25.1% by weight, 660 mPa · s / 25 ° C., and pH 5.1.

Production Example 11
In a reaction vessel similar to Production Example 1, 16.96 g of 80% methacrylic acid as component (a1), 13.56 g of styrene as component (a2) and 13.56 g of butyl methacrylate, 27.12 g of acrylamide as component (a4), In addition, 0.16 g of sodium dodecylbenzenesulfonate as a surfactant, 220 g of ion-exchanged water, 1.80 g of α-methylstyrene dimer as a chain transfer agent, and 1.60 g of normal dodecyl mercaptan were charged, and the mixture was stirred while stirring nitrogen. The reaction system was heated to 60 ° C. under gas bubbling. Next, 4.40 g of APS was added, the temperature was raised to 90 ° C., and held for 180 minutes. Subsequently, 16.31 g of 48% sodium hydroxide aqueous solution was added, and a predetermined amount of ion-exchanged water was added to obtain an aqueous solution of an anionic copolymer salt (A5) having a weight average molecular weight of 18,000. The aqueous solution had a nonvolatile content of 25.1% by weight, a viscosity of 655 mPa · s / 25 ° C., and a pH of 9.5.

<Manufacture of reinforced rosin>
Production Example 12
In the same reaction vessel as in Production Example 1, 600.0 g of a melt of about 160 ° C. of ID rosin and 48 g of maleic anhydride were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream, thereby obtaining dihydroagatoic acid. A reinforced rosin (B6) having a 9.1 wt% content, a softening point of 99.0 ° C., and an acid value of 260.7 mg KOH / g was obtained.

Comparative production example 3
In the same reaction vessel as in Production Example 1, 600.0 g of a melt of about 160 ° C. of CN rosin and 48 g of maleic anhydride were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream to obtain dihydroagatoic acid. A reinforced rosin (C) having a content of 0 wt%, a softening point of 98.8 ° C., and an acid value of 242.2 mg KOH / g was obtained.

<Preparation of rosin emulsion sizing agent>
Example 8
In a reaction vessel similar to Production Example 1, 70 g of reinforced rosin (B6) of Production Example 12 and 30 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, with stirring, 7 g of an aqueous solution of the anionic copolymer salt (A4) of Production Example 10 (in terms of solid content) was gradually added dropwise to form a W / O emulsion, and hot water was added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.56 μm, a non-volatile content of 50.3% by weight, a pH of 4.9, and a viscosity of 56 mPa · s / 25 ° C.

Example 9
In a reaction vessel similar to Production Example 1, 70 g of reinforced rosin (B6) of Production Example 12 and 30 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A5) of Production Example 11 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.58 μm, a nonvolatile content of 50.4% by weight, a pH of 4.9, and a viscosity of 52 mPa · s / 25 ° C.

Example 10
In a reaction vessel similar to Production Example 1, 70 g of reinforced rosin (B6) of Production Example 12 and 30 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, with stirring, 7 g of an aqueous solution of the anionic copolymer salt (A4) of Production Example 10 (in terms of solid content) was gradually added dropwise to form a W / O emulsion, and hot water was added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.39 μm, a nonvolatile content of 50.3% by weight, a pH of 4.8, and a viscosity of 63 mPa · s / 25 ° C.

Example 11
In a reaction vessel similar to Production Example 1, 50 g of the reinforced rosin (B6) of Production Example 12 and 50 g of the rosin ester (C1) obtained in Production Example 3 were charged and melted by heating at about 160 ° C. Next, with stirring, 7 g of an aqueous solution of the anionic copolymer salt (A4) of Production Example 10 (in terms of solid content) was gradually added dropwise to form a W / O emulsion, and hot water was added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.55 μm, a non-volatile content of 50.1 wt%, a pH of 4.9, and a viscosity of 56 mPa · s / 25 ° C.

Comparative Example 5
In a reaction vessel similar to Production Example 1, 70 g of reinforced rosin (C) of Comparative Production Example 3 and 30 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, with stirring, 7 g of an aqueous solution of the anionic copolymer salt (A4) of Production Example 10 (in terms of solid content) was gradually added dropwise to form a W / O emulsion, and hot water was added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain an average primary particle size of 0.57 μm, a non-volatile content of 50.2% by weight, a pH of 4.8, and a viscosity of 58 mPa · s / 25 ° C.

<Neutral papermaking and size test>
Using the sizing agent of Example 8, neutral paper making using L-BKP was carried out according to Test 3 above, and an obtained paper having basis weights of 80 g / m ² , 150 g / m ² , and 300 g / m ² was obtained. The degree of sizing human sizing was measured. The results are shown in Table 5.

Similarly, using the sizing agent of Example 8, neutral paper making using waste paper pulp was performed according to Test 4 above, and obtained papers having basis weights of 80 g / m ² , 150 g / m ² , and 300 g / m ² , Each Cobb water absorption (contact time 1 minute) was measured. The results are shown in Table 5.

  Similarly, papers having different basis weights were obtained for the sizing agents of Examples 9 to 11 and Comparative Example 5, respectively, and the Steecht sizing degree and the Cobb water absorption degree (contact time of 1 minute) were measured. The results are shown in Table 5.

<Production of acrylamide-based anionic copolymer salt>
Production Example 13
In a reaction vessel similar to Production Example 1, 7.24 g of itaconic acid and 6.88 g of sodium styrenesulfonate as the component (a1), 2.05 g of 2-ethylhexyl acrylate and 13.10 g of cyclohexyl methacrylate as the component (a2), (a3 ) 5.28 g of sodium methallyl sulfonate as component, 63.72 g of acrylamide as component (a4), 1.74 g of hexaethylene glycol diacrylate as component (a6), 220 g of ion-exchanged water and 250 g of isopropyl alcohol, and stirred. The reaction system was heated to 50 ° C. under nitrogen gas bubbling. Next, 2.20 g of APS was added, the temperature was raised to 80 ° C., and held for 180 minutes. Next, isopropyl alcohol was removed by blowing water vapor, and ion exchange water was added to obtain an aqueous solution of an anionic copolymer salt (A6) having a weight average molecular weight of 14,000. The aqueous solution had a nonvolatile content of 25.4% by weight, a viscosity of 390 mPa · s, and a pH of 4.5.

<Manufacture of reinforced rosin>
Production Example 14
In a reaction vessel similar to Production Example 1, 600.0 g of a melt of about 160 ° C. of ID rosin, 36 g of maleic anhydride, and 9 g of fumaric acid were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream. As a result, a reinforced rosin (B7) having a dihydroagatoic acid content of 9.2 wt%, a softening point of 108.6 ° C., and an acid value of 246.7 mgKOH / g was obtained.

Comparative production example 4
In the same reaction vessel as in Production Example 1, 600.0 g of a melt of CN rosin at about 160 ° C., 36 g of maleic anhydride, and 9 g of fumaric acid were charged and reacted at 200 ° C. for 2 hours with stirring under a nitrogen stream. As a result, a reinforced rosin (2) having a dihydroagatoic acid content of 0% by weight, a softening point of 105.6 ° C., and an acid value of 228.1 mgKOH / g was obtained.

<Preparation of rosin emulsion sizing agent>
Example 12
In a reaction vessel similar to Production Example 1, 76 g of reinforced rosin (B7) of Production Example 14 and 24 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A6) of Production Example 13 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added to stabilize the emulsion. An O / W emulsion was prepared. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.60 μm, a nonvolatile content of 50.3% by weight, a pH of 4.7, and a viscosity of 136 mPa · s / 25 ° C.

Comparative Example 6
In a reaction vessel similar to Production Example 1, 76 g of reinforced rosin (II) of Comparative Production Example 4 and 24 g of rosin ester (C1) of Production Example 3 were charged and heated and melted at about 160 ° C. Next, under stirring, 7 g of an aqueous solution of the anionic copolymer salt (A-6) of Production Example 13 (in terms of solid content) is gradually added dropwise to form a W / O emulsion, and hot water is further added. A stable O / W emulsion was obtained. Thereafter, the emulsion was cooled to room temperature to obtain a sizing agent having an average primary particle size of 0.56 μm, a non-volatile content of 50.4% by weight, a pH of 4.8, and a viscosity of 139 mPa · s / 25 ° C.

<Neutral papermaking and size test>
Using the rosin-based emulsion sizing agent of Example 12, neutral papermaking using L-BKP was performed according to the above test 3, and the basis weight was 80 g / m ² , 150 g / m ² , and 300 g / m ² . Then, the degree of sizing of each adult paper was measured. The results are shown in Table 6.

Similarly, using the rosin-based emulsion sizing agent of Example 12, neutral paper making using waste paper pulp was performed according to Test 4 above, and the resulting papers had basis weights of 80 g / m ² , 150 g / m ² , and 300 g / m ² . Each Cobb water absorption (contact time 1 minute) was measured. The results are shown in Table 6.

  Similarly, papers having different basis weights were also obtained for the rosin emulsion sizing agent of Comparative Example 6, and the Steecht sizing degree and the Cobb water absorption degree (contact time 1 minute) were measured for each. The results are shown in Table 6.

Claims (14)

In the presence of the copolymer (A) having an anionic functional group,
Rosin (b1) and α, β-unsaturated dicarboxylic acid (b2) addition reaction product containing at least 0.5% by weight of dibasic diterpene carboxylic acid (B) and optionally Emulsified rosin ester (C),
Rosin emulsion sizing agent. (A) A copolymer or a salt thereof in which the component is an anionic unsaturated monomer (a1), a hydrophobic unsaturated monomer (a2) and a chain transfer unsaturated monomer (a3) The rosin emulsion sizing agent according to claim 1, wherein The rosin emulsion sizing agent according to claim 2, wherein the component (a1) is a carboxyl group-containing unsaturated monomer or a salt thereof, and / or a sulfonic acid group-containing unsaturated monomer or a salt thereof. The rosin-based emulsion sizing agent according to claim 3, wherein the carboxyl group-containing unsaturated monomer or a salt thereof is itaconic acid or a salt thereof. The rosin emulsion sizing agent according to any one of claims 2 to 4, wherein the component (a2) is styrenes and / or alkyl (meth) acrylates. The rosin emulsion sizing agent according to any one of claims 2 to 5, wherein the component (a3) is (meth) allylsulfonic acid or a salt thereof. The component (A) further comprises at least one selected from the group consisting of acrylamides (a4), hydroxyl group-containing unsaturated monomers (a5) and crosslinkable unsaturated monomers (a6) as a reaction component. A rosin emulsion sizing agent according to any one of 2 to 6. The rosin emulsion type sizing agent according to any one of claims 1 to 7, wherein the component (A) has a weight average molecular weight of 4,000 to 100,000. The softening point of (B) component is 85-140 degreeC, and an acid value is 195-320 mgKOH / g, The rosin type emulsion sizing agent in any one of Claims 1-8. (C) The rosin type emulsion size agent in any one of Claims 1-9 whose polyhydric alcohol which comprises a component is a trihydric alcohol and / or a tetrahydric alcohol. The rosin emulsion size according to any one of claims 1 to 10, wherein the weight ratio [(C) / {(B) + (C)}] used between the component (B) and the component (C) is 0 to 0.4. Agent. The rosin-based emulsion sizing agent according to any one of claims 1 to 11, wherein the amount of the component (A) used is 5 to 12 parts by weight based on 100 parts by weight of the component (B) and the component (C). The rosin emulsion sizing agent according to any one of claims 1 to 12, having an average primary particle size of 0.1 to 1.2 µm. A paper obtained using the rosin emulsion sizing agent according to claim 1.