JP2003313251A - Polymeric dispersant, aqueous dispersion, sizing agent and paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polymeric emulsifying agent excellent in dispersing ability, an aqueous emulsion excellent in dispersion stability and mechanical stability, a sizing agent, and a paper excellent in sizing effect and obtained by using the sizing agent. <P>SOLUTION: The polymeric emulsifying agent is obtained by polymerizing a monomer (a) represented by formula (1) and (meth)acrylamide (b). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer dispersant, an aqueous dispersion in which a hydrophobic compound is dispersed using the polymer dispersant, a sizing agent, and paper obtained using the sizing agent. Specifically, a polymer dispersant having excellent dispersibility, an aqueous dispersion having excellent dispersion stability and mechanical stability, a sizing agent exhibiting an excellent sizing effect, and a paper obtained using such a sizing agent. Regarding

[0002]

2. Description of the Related Art Aqueous dispersions containing polymer dispersants are widely used in many fields such as pharmaceuticals, agricultural chemicals, foods, cosmetics and paper-making chemicals. Known polymer dispersants are aqueous polymers such as starch, polyvinyl alcohol, carboxylated methyl cellulose, polyacrylamide, and styrene (meth) acrylic acid.

In the papermaking field, an aqueous dispersion prepared by dispersing a rosin-based substance, a 2-oxetanone compound and a substituted cyclic dicarboxylic acid anhydride with a polymer dispersant is used as a sizing agent for imparting water resistance to paper. . However, since such conventional sizing agents have insufficient dispersion stability and mechanical stability, they often stain papermaking tools such as press rolls and felts in the papermaking process. Further, there is a problem that the stain component adheres to the paper and deteriorates the quality of the paper. Development of a sizing agent that solves such problems is desired. Further, from the viewpoint of not only stain prevention but also economical efficiency, it is desired to develop a sizing agent which exerts an excellent sizing effect even when added in a small amount.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a polymeric dispersant having excellent dispersion performance, an aqueous dispersion having excellent dispersion stability and mechanical stability, and a sizing agent having an excellent effect of improving the sizing degree. The purpose is to provide a paper obtained using a sizing agent.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems, and as a result, found that the tertiary or quaternary methallyl ammonium salt represented by the general formula (1) of the present invention. A polymer obtained by polymerizing (meth) acrylamide with (meth) acrylamide has excellent dispersion performance, and a sizing agent using this as a polymer dispersant has excellent dispersion stability, mechanical stability and sizing degree improving effect. The present invention has been completed and the present invention has been completed.

That is, the present invention, which is a means for solving the above-mentioned problems, includes (1) a monomer (a) represented by the following general formula (1):
A polymer dispersant characterized by being polymerized with the following monomer (b). (A) General formula (1) Wherein, ^{R 1} represents an alkylene group having 1 to 4 carbon ^atoms, R 2 to R
⁴ is a hydrogen atom or 30 carbon atoms which may have a substituent
The following alkyl groups are shown (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms). X ^-
Represents an anion of an inorganic acid or an organic acid. ] The compound shown by these, (b) (meth) acrylamide

(2) A monomer (a) represented by the following general formula (1), the following monomer (b), and the following monomer (c) and / or the following monomer (d) are polymerized. And a polymer dispersant. (A) General formula (1) Wherein, ^{R 1} represents an alkylene group having 1 to 4 carbon ^atoms, R 2 to R
⁴ is a hydrogen atom or 30 carbon atoms which may have a substituent
The following alkyl groups are shown (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms). X ^-
Represents an anion of an inorganic acid or an organic acid. ] (B) (meth) acrylamide, (c) Ionic monomer (d) hydrophobic monomer other than monomer (a) represented by the general formula (1)

(3) An aqueous dispersion comprising the polymer dispersant of (1) or (2) above, a hydrophobic compound and water.

(4) The hydrophobic compound is a rosin-based substance, 2-
The aqueous dispersion according to (3), which is at least one selected from the group of oxetanone compounds and substituted cyclic dicarboxylic acid anhydrides.

(5) The polymer dispersant of (1) or (2) above, the hydrophobic compound and water are mixed under high shear by using a high shear rotary emulsifier or a high pressure discharge homogenizer. An aqueous dispersion according to (3) or (4), characterized in that

(6) The aqueous dispersion according to the above (3) to (5), wherein the aqueous dispersion is a sizing agent.

(7) Paper obtained using the sizing agent of (6) above.

(8) The paper according to (7), which is high-quality paper, medium-quality paper or recycled paper containing calcium carbonate.

(9) The paper according to (7), which is a base paper for liquid containers, a base paper for photographic printing paper, and a base paper for gypsum board.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer dispersant of the present invention comprises a monomer (a) and a monomer (b), or a monomer (a) and a monomer (b), and further a monomer (c) and / or a monomer (d). Can be obtained by polymerizing at least.
The monomer (a) used in the present invention is a compound represented by the following general formula (1), and these may be used alone or in combination of two or more. Further, these can be used in the form of powder or solution. (A) General formula (1) Wherein, ^{R 1} represents an alkylene group having 1 to 4 carbon ^atoms, R 2 to R
⁴ is a hydrogen atom or 30 carbon atoms which may have a substituent
The following alkyl groups (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms). X ^-
Represents an anion of an inorganic acid or an organic acid. ]

R ¹ is an alkylene group having 1 to 4 carbon atoms, specifically, a methylene group (—CH ₂ —), an ethylene group (—CH ₂ CH ₂ —), a propylene group (—CH ₂ CH).
₂ CH ₂ -), butylene _{(-CH 2} CH 2 _CH 2 CH
_2- ), and a methylene group is preferable. R ^{2 to} R ⁴
Is a hydrogen atom or an alkyl group optionally having a substituent and having 30 or less carbon atoms (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms), preferably 30 carbon atoms. The following alkyl group, alkenyl group, hydroxyalkyl group, alkylamine group, alkyl ether group, alkyl ester group, alkylamide group, aryl group, or any two of R ^{2 to} R ⁴ are combined to form a cyclic structure. It is a base. Specifically, R ^{2 to} R ⁴ are a methyl group, an ethyl group, a butyl group, a stearyl group, a hydroxyethyl group, and a benzyl group, and these may be the same substituent or a combination of different substituents. May be
Specific examples of the cyclic structure include a morpholine skeleton structure including a nitrogen atom, R ³ and R ⁴ . In addition, R ^{2 to} R ⁴
More preferably, any one, two, or three of the above are alkyl groups having 4 to 22 carbon atoms, and the remaining R ^{2 to} R ⁴ are alkyl groups having 1 to ⁴ carbon atoms.

X ^- is an anion in inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, and nitric acid, or organic acids such as carboxylic acids such as formic acid, acetic acid, oxalic acid, and propionic acid. Yes, Cl ⁻ , Br ⁻ , and I ⁻ are preferable, and Cl ⁻ is more preferable.

Examples of the monomer (a) represented by the general formula (1) include 2-propene-1-aminium, N, N, N, 2-tetramethyl, chloride and 2-propene-1-aminium.
Propene-1-aminium, N, N-diethyl-2-methyl, hydrochloride, 2-propene-1-aminium, N, N, N-triethyl-2-methyl, chloride, 2-propene-1-aminium, N , N, N-tributyl-2-methyl, chloride, 2-propene-1-
Aminium, N, N, 2-trimethyl-N-octadecyl, chloride, benzenemethaneaminium, N, N-
Dimethyl-N- (2-methyl-2-propenyl), chloride, N-methyl-N- (2-methyl-2-propenyl) morpholinium chloride, 2-propen-1-
Aminium, N-hydroxyethyl-N, N, 2-trimethyl, chloride, 2-propen-1-aminium,
Examples thereof include N, N-dihydroxyethyl-N, 2-dimethyl, chloride, 2-propene-1-aminium, N-hydroxyethyl-N, 2-dimethyl and hydrochloride.

The (meth) acrylamide used as the monomer (b) in the present invention is 2-propenamide (that is, acrylamide) or 2-methyl-2-propenamide (that is, methacrylamide). The more preferred monomer (b) is 2-propenamide. These can be used in the form of powder or solution.

Examples of the ionic monomer other than the monomer (a) represented by the general formula (1), which is the monomer (c) used in the present invention, include anionic monomers and cationic monomers, and these are one kind alone. , Or two or more kinds can be used, and various selection can be made depending on the properties of the polymer dispersant required.

Examples of the anionic monomer include a carboxyl group-containing monomer (which means a carboxyl group-containing polymerizable vinyl monomer) and a sulfonic acid group-containing monomer (which is a sulfonic acid group-containing polymerizable monomer). Vinyl monomer), a phosphoric acid group-containing monomer (this means a polymerizable vinyl monomer having a phosphoric acid group), and alkali metal salts, alkaline earth metal salts, and ammonium thereof. Salts such as salt may be mentioned. These may be used alone or in combination of two or more.

As the carboxyl group-containing monomer, 2-propenoic acid (that is, acrylic acid), 2-methyl-2-propenoic acid (that is, methacrylic acid), trans-
Unsaturated monocarboxylic acids such as 3-phenylpropenoic acid (ie, cinnamic acid) and trans-2-butenoic acid (ie, crotonic acid), N- (1-carboxylmethylol)-
2-propenamide (ie, 2-acrylamidoglycolic acid), and N- (1-carboxyl methylol)
Glyoxylic acid such as 2-methyl-2-propenamide (that is, 2-methacrylamidoglycolic acid), trans-2-butenedioic acid (that is, fumaric acid), cis-2-butenedioic acid (that is, ,
Maleic acid), 2-methylene butanedioic acid (ie itaconic acid), (Z) -2-methyl-2-butenedioic acid (ie citraconic acid), and trans, trans-2,4-hexadiendio. Unsaturated dicarboxylic acids such as ic acid (that is, muconic acid), propene-cis-1,2,3-tricarboxylic acid (that is, aconitic acid), 3-butene-1,2,3-tricarboxylic acid, and 4- Unsaturated tricarboxylic acids such as pentene-1,2,4-tricarboxylic acid, 1-pentene-1,
1,4,4-tetracarboxylic acid, 4-pentene-1,
2,3,4-tetracarboxylic acid, and 3-hexene-
Examples thereof include unsaturated tetracarboxylic acids such as 1,1,6,6-tetracarboxylic acid and salts thereof such as alkali metal salts, alkaline earth metal salts and ammonium salts. These may be used alone or in combination of two or more.

As the sulfonic acid group-containing monomer,
For example, ethylenesulfonic acid (that is, vinylsulfonic acid), 4-ethylenebenzenesulfonic acid (that is, styrenesulfonic acid), 2-propene-1-sulfonic acid (that is, allylsulfonic acid), 2-methyl-2-propene. −
1-sulfonic acid (ie, methallyl sulfonic acid), and 2
-Methyl-N-propenoyl-2-aminopropanesulfonic acid (that is, 2-acrylamido-2-methylpropanesulfonic acid), and salts thereof such as alkali metal salts, alkaline earth metal salts, and ammonium salts.
These may be used alone or in combination of two or more.

Examples of the phosphoric acid group-containing monomer include ethylenephosphonic acid (that is, vinylphosphonic acid), 1-phenylethylenephosphonic acid (that is, 1-phenylvinylphosphonic acid), alkali metal salts thereof, and alkaline earth metals. Examples thereof include salts such as metal salts and ammonium salts. These may be used alone or in combination of two or more.

Examples of the cationic monomer include vinyl monomers having a primary amino group, vinyl monomers having a secondary amino group, vinyl monomers having a tertiary amino group, and vinyl monomers having a quaternary ammonium salt. . These may be used alone or in combination of two or more.

Examples of the vinyl monomer having a primary amino group include 2-propenylamine (that is, allylamine), 2-methyl-2-propenylamine (that is, methallylamine), and salts thereof. Examples of these salts include inorganic acid salts such as hydrochloride and sulfate, and organic acid salts such as formate and acetate. These may be used alone or in combination of two or more.

Examples of the vinyl monomer having a secondary amino group include di (2-propenyl) amine (ie, diallylamine), di (2-methyl-2-propenyl) amine (ie, dimethallylamine), and salts thereof. Can be mentioned. Examples of these salts include inorganic acid salts such as hydrochloride and sulfate, and organic acid salts such as formate and acetate. These may be used alone or in combination of two or more.

Further, as the vinyl monomer having a secondary amino group, it has the primary amino group such as 2-propenylamine (that is, allylamine) and 2-methyl-2-propenylamine (that is, methallylamine). Secondary reaction by reaction of vinyl monomer with alkyl halide such as methyl chloride and methyl bromide, aralkyl halide such as benzyl chloride and benzyl bromide, dialkyl sulfuric acid such as dimethylsulfate and diethylsulfate, epichlorohydrin, etc. Examples include monomers that are acid salts of amines. These may be used alone or in combination of two or more.

Examples of the vinyl monomer having a tertiary amino group include N, N-dimethyl-2-properoyloxyethylamine (that is, dimethylaminoethyl acrylate) and N, N-dimethyl-2- (2-methylpropene). Royloxy) ethylamine (that is, dimethylaminoethyl methacrylate), N, N-diethyl-2-properoyloxyethylamine (that is, diethylaminoethyl acrylate), N, N-diethyl-2- (2-methylproperoyloxy) ethylamine (That is, diethylaminoethyl methacrylate), N, N-dimethyl-3-properoyloxypropylamine (that is, dimethylaminopropyl acrylate), N, N-dimethyl-3- (2-
Methylproperoyloxy) propylamine (that is, dimethylaminopropyl methacrylate), N, N-diethyl-3-propellyloxypropylamine (that is, diethylaminopropyl acrylate), and N, N-diethyl-3- (2-methyl) Properyloxy) propylamine (ie diethylaminopropylmethacrylate)
Such as dialkylaminoalkyl (meth) acrylates, N, N-dimethyl-3-properoylaminopropylamine (that is, dimethylaminopropylacrylamide), N, N-dimethyl-3- (2-methylproperoylamino) propyl Amine (ie, dimethylaminopropylmethacrylamide), N, N-diethyl-3-properoylaminopropylamine (ie, diethylaminopropylacrylamide), and N, N-diethyl-3.
Examples thereof include dialkylaminoalkyl (meth) acrylamides such as-(2-methylproperoylamino) propylamine (that is, diethylaminopropylmethacrylamide) and salts thereof. Examples of these salts include inorganic acid salts such as hydrochloride and sulfate, and organic acid salts such as formate and acetate.
These may be used alone or in combination of two or more.

As the vinyl monomer having a tertiary amino group, di (2-propenyl) amine (that is, diallylamine), di (2-methyl-2-propenyl) amine (that is, dimethallylamine), and the like 2 Vinyl monomer having a primary amino group, methyl chloride,
And an alkyl halide such as methyl bromide, benzyl chloride, an aralkyl halide such as benzyl bromide, an alkyl sulfuric acid such as dimethylsulfate and diethylsulfate, and a monomer which is converted to an acid salt of a tertiary amine by reaction with epichlorohydrin or the like. Is mentioned. These may be used alone or in combination of two or more.

As the vinyl monomer having the quaternary ammonium salt, N, N-dimethyl-N, N-di (2
-Propenyl) ammonium chloride (i.e. diallyldimethylammonium chloride), N, N-dimethyl-N, N-di (2-methyl-2-propenyl) ammonium chloride (i.e. dimethallyldimethylammonium chloride), N, N- Diethyl-N, N-di (2
-Propenyl) ammonium chloride (that is, diallyldiethylammonium chloride), N, N-diethyl-N, N-di (2-methyl-2-propenyl) ammonium chloride (that is, diethyldimethallylammonium chloride), and the like. . These may be used alone or in combination of two or more.

Further, examples of the vinyl monomer having the quaternary ammonium salt include a vinyl monomer obtained by reacting the vinyl monomer having a tertiary amino group with a quaternizing agent. Examples of the quaternizing agent include an alkyl halide such as methyl chloride and methyl bromide, an aralkyl halide such as benzyl chloride and benzyl bromide, an alkyl sulfuric acid such as dimethyl sulfuric acid and diethyl sulfuric acid, epichlorohydrin, 3-chloro-
2-hydroxypropyl trimethyl ammonium chloride, glycidyl trialkyl ammonium chloride, etc. are mentioned. Specifically, N, N, N-trimethyl-2-[(1-oxo-2-propenyl) oxy]
Ethaneaminium chloride (ie acryloyloxyethyltrimethylammonium chloride), N,
N, N-Trimethyl-2-[(2-methyl-1-oxo-2-propenyl) oxy] ethaneaminium chloride (ie, methacryloyloxyethyltrimethylammonium chloride), N, N-dimethyl-N- [2
[(1-Oxo-2-propenyl) oxy] ethyl] benzenemethanaminium chloride (ie, acryloyloxyethyl dimethylbenzylammonium chloride), N, N-dimethyl-N- [2 [(2-methyl-1
-Oxo-2-propenyl) oxy] ethyl] benzenemethanaminium chloride (ie, methacryloyloxyethyldimethylbenzylammonium chloride), N, N-dimethyl-N- [2 [(1-oxo-2
-Propenyl) oxy] propyl] benzenemethanaminium chloride (ie, acryloyloxypropyldimethylbenzylammonium chloride), and N,
N-dimethyl-N- [2 [(2-methyl-1-oxo-
2-propenyl) oxy] propyl] benzenemethanaminium chloride (that is, methacryloyloxypropyldimethylbenzylammonium chloride) and the like. These may be used alone or in combination of two or more.

These primary amino groups, secondary amino groups, 3
The vinyl monomer having a primary amino group or a quaternary ammonium salt may be used alone or in combination of two or more.

The hydrophobic monomer used as the monomer (d) in the present invention is specifically styrenes such as styrene, α-methylstyrene, vinyltoluene, and divinylbenzene, alkyl (meth) acrylates such as methyl ( (Meth) acrylate, ethyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth)
Acrylate and diethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclic alkyl (meth) acrylate, dialkyl diesters such as maleic acid and fumaric acid, vinyl esters, for example, having 5 to 10 carbon atoms. Tertiary vinyl carboxylates and vinyl propionates, N-
Alkyl (meth) acrylamides, as well as methyl vinyl ether are mentioned. One of these various hydrophobic monomers can be used alone, or two or more thereof can be used in combination.

Among them, styrenes and alkyl (meth)
Any of the acrylates alone or in combination thereof, the alkyl (meth) acrylates have 4 to 18 carbon atoms.
More preferably, it is a compound having an alkyl group of

In the present invention, during the polymerization, a monomer (“monomer (f)” other than the above-mentioned monomer (a), monomer (b), monomer (c) and monomer (d) is used.
Sometimes called. ) Can also be used. Examples of this monomer (f) include nonionic vinyl monomers and crosslinkable monomers. These may be used alone or in combination of two or more.

When the monomer (a) and the monomer (b) are used, the polymer dispersant of the present invention contains the monomer (a) based on the total amount of the respective components of the monomer (a) and the monomer (b). Is usually 0.005 to 20 mol%, preferably 0.01 to 10 mol%, and the monomer (b) is usually 80 to 9
9.995 mol%, preferably 90-99.99 mol%
Is. Further, a monomer (f) other than the above, which is copolymerizable with the monomer (a) and the monomer (b).
Can be used in an amount of 10 mol% or less, preferably 5 mol% or less, based on the total amount of the respective components of the monomer (a) and the monomer (b).

When the components of the monomer (a) and the monomer (b), and further the monomer (c) and / or the monomer (d) are used, the monomer (a),
The amount of the monomer (a) is usually 0.005 to 20 mol%, preferably 0.01 to 10 mol%, based on the total amount of the respective components of the monomer (b), the monomer (c) and / or the monomer (d). b) is usually 10 to 99.99 mol%,
Preferably 30 to 99.98 mol%, the amount of the monomer (c) and / or the monomer (d) is usually 0.005 to 70 mol%, preferably 0.01 to 60 mol%, an anionic monomer and a cationic monomer. The ratio of can be arbitrarily selected from the viewpoint of the performance of the sizing agent. Further, the other monomer (f) other than the above which can be copolymerized with the monomer (a), the monomer (b), the monomer (c) and / or the monomer (d) is the monomer (a), the monomer ( It can be used in an amount of 10 mol% or less, preferably 5 mol% or less, based on the total of the respective components of b), the monomer (c) and / or the monomer (d).

In carrying out the polymerization for obtaining the polymer dispersant in the present invention, a known polymerization method can be adopted. When a polymerization initiator is used in the polymerization, known polymerization initiators can be used. Specifically, persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate, benzoyl peroxide, hydrogen peroxide, t
ert-butyl hydroperoxide, and di-te
Peroxides such as rt-butyl peroxide, bromates such as sodium bromate and potassium bromate, perborates such as sodium perborate and ammonium perborate, sodium percarbonate, potassium percarbonate, And percarbonates such as ammonium percarbonate, and perphosphates such as sodium perphosphate, potassium perphosphate, and ammonium perphosphate. These may be used alone or in combination of two or more, and may be used in combination with a reducing agent as a redox polymerizing agent. Examples of the reducing agent include sulfites such as sodium sulfite, bisulfites such as sodium bisulfite, metabisulfites such as sodium metabisulfite, and organic such as N, N, N ′, N′-tetramethylethylenediamine. Examples thereof include amines and reducing sugars such as aldose. Moreover, these reducing agents may be used alone or in combination of two or more.

In addition to the above, azobisisobutyronitrile, 2,2'-azobis- (2-amidinopropane) dihydrochloride, 2,2'-azobis- (2,4'-dimethylvaleronitrile) , 1,1-azobis- (cyclohexane-1-carbonitrile), 2,2′-azobis- [2-methyl-N- (2-hydroxyethyl) propionamide], and 4,4′-azobis- (4 It is also possible to use an azo polymerization initiator such as -cyanopentionic acid) (that is, 4,4'-azobis- (4-cyanovaleric acid)), or a salt thereof.

When a monomer is usually polymerized, a polymerization initiator is added to the monomer solution to start the polymerization. However, a part of the polymerization initiator may be additionally added during the polymerization for the purpose of reducing unreacted monomers. Radiation, electron beam,
Alternatively, a method of irradiating with ultraviolet rays can be used. These methods can be used alone or in combination of two or more.

In the polymerization for obtaining the polymer dispersant in the present invention, known chain transfer agents which do not correspond to the monomers (a) to (d) can be used. The amount of these used is 0 to 20 mol% based on the total of the monomer (a) and the monomer (b), or the monomer (a) and the monomer (b) and the monomer (c) and / or (d). , Preferably 0 to 10 mol%.

Known chain transfer agents include compounds having one or more hydroxyl groups in the molecule, compounds having one or more mercapto groups in the molecule, and one or more in the molecule. The compound etc. which have a carbon-carbon unsaturated bond can be mentioned.

Examples of the compound having one or more hydroxyl groups in the molecule include alcohols such as ethanol, 2-propanol, butanol, ethylene glycol and glycerin, polymers such as polyethylene oxide and polyglycerin, and glucose. , Ascorbic acid, saccharides such as sucrose, and vitamins.

Examples of the compound having one or more mercapto groups in the molecule include butyl mercaptan, mercaptoethanol, thioglycolic acid, thioglycolic acid alkyl ester, mercaptopropionic acid, mercaptopropionic acid alkyl ester and thioglycerin. , And cysteamine, and salts thereof.

Examples of the compound having one or more carbon-carbon unsaturated bonds in the molecule include 2-propenol (that is, allyl alcohol), 2-methyl-2-propenol (that is, methallyl alcohol), and The ester derivative, 2-propenyl halide (that is, allyl halide), 2-methyl-2-propenyl halide (that is, methallyl halide), 3-butenic acid (that is, allylcarboxylic acid), and 3-methyl-3-. Buteneic acid (that is, methallylcarboxylic acid) and its ester derivative, 2-propenyl sulfides (that is, allyl sulfides), 2-methyl-2-propenyl sulfides (that is, methallyl sulfides), 2- Propenyl mercaptans (ie, allyl mercaptans), and 2-methyl-2 Propenyl mercaptans (ie,
Methallyl mercaptans) and the like.

Further, known chain transfer agents include peroxides such as dibutyl peroxide and hypophosphorous acid.

The synthesis of the polymer dispersant in the present invention is carried out in a predetermined reaction vessel under an atmosphere of an inert gas such as nitrogen, with monomers and, if necessary, a chain transfer agent and the like, water or an organic solvent (water). May be used together with the organic solvent)
The polymer dispersant of the present invention can be obtained by charging and, and stirring to add the above-mentioned polymerization initiator to start the polymerization. Also, the polymer dispersant of the present invention can be obtained by dropping and polymerizing monomers, a chain transfer agent, a polymerization initiator, etc. even if they are dividedly added.

A chelating agent may be added during or after the polymerization of the polymer dispersant of the present invention. As the chelating agent, various ones that coordinate with metal ions can be used,
In the present invention, it is preferable to use one or more selected from citric acid, malic acid, tartaric acid, lactic acid and the like. Particularly preferred is citric acid.

In the polymerization of the present invention, the polymerization can be carried out in the presence of a water-soluble polymer to the extent that the object of the present invention is not impaired. Examples of the water-soluble polymer include starches, polyvinyl alcohols, celluloses, gums and the like.

A polymer dispersant is obtained by the above-mentioned polymerization operation. The solid content concentration of this polymer dispersant is usually 5 to 60% by weight. The solid content of the polymer dispersant is 20%.
Viscosity at 25 ° C. measured with a Brookfield rotational viscometer of 3 to 30,000 mPa · s,
It is preferably 10 to 5,000 mPa · s. The polymeric dispersant is used to form an aqueous dispersion that can be used as a sizing agent according to the present invention.

The aqueous dispersion according to the present invention refers to a liquid in which a hydrophobic compound is dispersed in a liquid phase or a solid phase by a polymer dispersant in an aqueous medium.

Examples of the hydrophobic compound in the present invention include rosin-based substances, 2-oxetanone compounds, substituted cyclic dicarboxylic acid anhydrides, etc. These may be used alone or in combination of two or more.

Examples of the rosin-based substance include rosins, toughened rosins, rosin esters and toughened rosin esters, and one or more of these can be used. Examples of rosins include gum rosin, tall oil rosin, and wood rosin, and further, modified products of each of these, such as hydrogenated rosin, disproportionated rosin, polymerized rosin, and aldehyde-modified rosin, which may be used alone or It can be used as a mixture of any two kinds.

The toughened rosins are the same as the above rosins in -C = C.
This is an addition reaction of an acidic compound containing a -C = O group, and the proportion thereof is usually 1 to 20% by weight, preferably 3 to 18% by weight. As a typical example of this acidic compound, α,
Examples of the β-unsaturated carboxylic acid and its anhydride include α, β-unsaturated compounds such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride. Examples of the dibasic carboxylic acid and its anhydride, α, β-unsaturated monobasic carboxylic acid such as acrylic acid and methacrylic acid, and these can be used alone or at least two kinds, but the strengthening method is a known method. It can be carried out.

Rosin esters are reaction products obtained by esterification reaction of the above rosins with alcohols, phenols, epoxy compounds, etc., and include complete and / or partial esterification products and unreacted products. It may contain rosins. As the alcohol, a polyhydric alcohol having a valence of 3 or more (not smaller than 3) can be used, and examples thereof include glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerin and sorbitol. As the phenols, polyhydric phenols having a valence of 2 or more (not less than divalent) can be used, and examples thereof include hydroquinone, pyrogallol, and bisphenol A. The epoxy compound is a compound having an oxirane ring, and examples thereof include epoxy resins such as glycidyl ether type epoxy resins. These alcohols, phenols, epoxy compounds and the like can be used in combination of at least one kind of each kind or at least one kind of each of at least two kinds.

The reinforced rosin esters are the rosin esters obtained by addition reaction of α, β-unsaturated carboxylic acid and / or its anhydride in the same manner as the above-mentioned reinforced rosins. Any step may be performed before the esterification reaction, at the same time as the esterification reaction, and after the esterification reaction, and at least two optional steps may be used in combination. When this is used as the component (A) and used as a sizing agent containing an emulsion dispersed in the component (B), from the viewpoint of the size effect, after the esterification reaction is completed, α, β-
It is preferable to carry out an addition reaction of an unsaturated carboxylic acid or the like.

The above-mentioned rosin esters and reinforced rosin esters are usually completely esterified products in which all the hydroxyl groups of alcohols and the like are esterified with the carboxyl groups of rosins and the like, and the part in which some of the hydroxyl groups are esterified. Although it is a mixture with an esterified product and unreacted rosin, etc., in the present invention, if it is within the range of the charging ratio at the time of the esterification reaction, it may be used as it is, and the rosin and / or the reinforced compound It may be mixed with rosins and used as the dispersed phase of the aqueous dispersion. At this time, the proportion of the rosin ester and / or the reinforced rosin ester in the total rosin-based substance is preferably 5 to 100% by weight. In the sizing agent of the present invention, if it is less than 5% by weight, when the sizing agent is dispersed with the polymer dispersant of the present invention, the sizing effect in the neutral or alkaline range may decrease. The above rosins and / or fortified rosins as rosin-based substances, and rosin esters and / or
Alternatively, when a mixture of reinforced rosin esters is used in the sizing agent of the present invention, when the sizing agent is used in a papermaking system having a high pH, that is, in the neutral to alkaline region, the above-mentioned size effect and low foaming property are obtained. Is more preferable in that

The 2-oxetanone compound has the general formula (2): (However, R ¹ and R ² in the formula (2) represent the same or different saturated or unsaturated alkyl groups or alkenyl groups having 8 to 24 carbon atoms.) Alkyl and / or Or an alkenyl ketene dimer and a general formula (3) (However, in the formula (3), n is a natural number and is usually 1 to 10
R ³ and R ⁵ are the same or different saturated or unsaturated alkyl or alkenyl groups having 8 to 24 carbon atoms, and R ⁴ is saturated or unsaturated having ⁴ to 40 carbon atoms. Is an alkyl group or an alkenyl group. ) Is a general term for alkyl and / or alkenyl ketene multimers having a basic structure of.

The 2-oxetanone compound has 6 carbon atoms.
To 30 saturated or unsaturated monocarboxylic acids with 6 carbon atoms
To 44 saturated dicarboxylic acids or unsaturated dicarboxylic acids, and their chlorides, and mixtures thereof as raw materials. Specific raw materials include stearic acid, isostearic acid, myristic acid, palmitic acid, pentadecanoic acid, decanoic acid as saturated monocarboxylic acids,
Undecanoic acid, lauric acid, tridecanoic acid, nonadecanoic acid, arachidic acid, and behenic acid, selected from the group consisting of acid chlorides thereof, and mixtures thereof, and oleic acid, linoleic acid, dodecenoic acid as unsaturated monocarboxylic acids. Selected from the group consisting of tetradecenoic acid, hexadecenoic acid, octadecadienoic acid, octadecatrienoic acid, eicosenoic acid, eicosatetraenoic acid, docosenoic acid and docosapentaenoic acid, and acid chlorides thereof, and mixtures thereof. To be done. Specific examples of the saturated or unsaturated dicarboxylic acid include sebacic acid, azelaic acid, 11,10-
It is selected from the group consisting of dodecane nitric acid, brazilic acid, docosanninic acid, and their acid chlorides, and mixtures thereof.

The 2-oxetanone compound can be synthesized by a usual organic synthesis method using the above-mentioned raw materials, and some of them can be easily obtained as a commercial product. For example, stearyl ketene dimer is obtained by reacting stearic acid with a chlorinating agent such as phosgene, phosphorus trichloride and thionyl chloride to obtain stearic acid chloride, followed by dehydrochlorination treatment with triethylamine, and then removal of triethylamine hydrochloride. .

The substituted cyclic dicarboxylic acid anhydride is represented by the general formula (4) (In the formula (3), R ⁶ is an alkyl group having 5 or more carbon atoms, an alkenyl group, an aralkyl group, or an aralkenyl group, and n is an integer of 2 to 3.) A substituted cyclic dicarboxylic acid having a basic structure. Anhydrous.

Specifically, hexadecyl succinic anhydride,
Alkyl succinic anhydride such as octadecyl succinic anhydride, hexadecenyl succinic anhydride, alkenyl succinic anhydride such as octadecenyl succinic anhydride, and hexadecyl glutaric anhydride, octadecyl glutaric anhydride And an alkylglutaric anhydride such as hexadecenyl glutaric anhydride and octadecenyl glutaric anhydride.

These substituted cyclic dicarboxylic acid anhydrides are
There are some which can be synthesized by a usual organic synthesis method and can be easily obtained as a commercial product. For example, hexadecyl succinic anhydride is synthesized by adding maleic anhydride to 1-hexadecene.

In producing the aqueous dispersion in the present invention, in addition to the hydrophobic compound, the polymer dispersant, and water, other dispersants, surfactants, water-soluble inorganic substances, and pH may be added if necessary.
A regulator can be used in combination. Examples of the dispersant include an anionic dispersant such as an alkali metal salt of a naphthalene sulfonic acid formalin condensate, an alkali metal salt of lignin sulfonic acid, or an amphoteric starch, an oxidized starch, a cationized starch, a cationic, anionic, or Polymeric dispersants such as amphoteric (meth) acrylamide polymers, polydiallyldimethylammonium chloride, polyamine epichlorohydrin resins and the like can be mentioned, and these can be used alone or in combination of two or more. Known cationic low-molecular-weight surfactants, anionic low-molecular-weight surfactants, amphoteric surfactants or nonionic low-molecular-weight surfactants can be used as necessary. If necessary, magnesium chloride, aluminum sulfate, polyaluminum chloride, polyaluminum hydroxide or the like can be used as the water-soluble inorganic substance. If necessary, inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as acetic acid and citric acid, and alkaline metal salts such as sodium hydroxide and sodium carbonate can be used as pH adjusters.

The content of the hydrophobic compound in this aqueous dispersion is usually 0.1 to 60% by weight, and the polymer dispersant based on the hydrophobic compound is usually 1 to 100% by weight based on the solid content.

In the present invention, the aqueous dispersion containing the hydrophobic compound can be manufactured as follows.
For example, a hydrophobic compound, a polymer dispersant, a mixed liquid of at least two or more kinds of water, or each of the above substances at a temperature not lower than the melting point or softening point of the hydrophobic compound, for example, a static mixer, a mixer with a stirring blade, a homogenizer. It is produced by mixing a hydrophobic compound, a polymer dispersant, and water under high shear with various emulsifying machines such as a mixer, a high-pressure discharge homogenizer, an ultrasonic emulsifier, and a high-shear rotary emulsifier. When the melting point or softening point of the hydrophobic compound exceeds 100 ° C., it is preferably produced under a pressure higher than atmospheric pressure. If necessary, other dispersants, surfactants, water-soluble inorganic substances, and water for adjusting the solid content of the pH adjuster can be used before and after mixing under the high shear.

The high-pressure discharge type homogenizer is a device for passing the treatment liquid pressurized by a pump through a narrow gap between a valve and a valve seat at high speed and colliding it with an impact ring surrounding a valve, and a Gorin homogenizer (AP
V Gorin Co., Ltd.) and Microfluidizer (Microfluidics Co.) can be exemplified.

The high-shear rotary emulsifier comprises a stator having a plurality of rings fixed to the main body of the emulsifier and spaced apart from each other, and a plurality of stators arranged in pairs so as to face each other. A rotor having rotating rings, each pair of rings is sequentially arranged, and each ring of the stator and the rotor has elongated holes and / or pores, and the rotor is rotated at a high speed. A device for mixing the treatment liquid under high shear. Commercially available high shear rotary emulsifiers include in-line dispersing mixer (YSTRAL), Bock bolt homogenizer (Bock bolt), Milder (Ebara Corporation), ONLATOR (Sakura Corporation). Examples thereof include PENTAX mixer (manufactured by Alfa Laval), SUPRATON (manufactured by KRUPP), CAVITRON (manufactured by CAVITRON), and stamp shear pump (manufactured by FRISTOM).

The aqueous dispersion produced in this way is
The average particle size of the particles containing the hydrophobic compound is 0.1 or more and 3 μm or less, preferably 0.3 or more and 1 μm or less. The average particle size of the particles containing the hydrophobic compound in the aqueous dispersion is the laser diffraction / scattering particle size distribution measuring device L
It was measured using A910 (manufactured by Horiba Ltd.), and the median diameter (50% diameter) is taken as the average particle diameter.

The sizing agent of the present invention can be used as both an internally added sizing agent and a surface sizing agent.

When used as an internally added sizing agent, the amount of the sizing agent added to the pulp slurry is 0.005 to 5% by weight, preferably 0.01 to 2% by weight, based on the dry weight of the pulp. is there.

In the production of the above various papers and paperboards, the pulp raw material is bleached or unbleached of kraft pulp, sulfite pulp or the like, or bleached or unbleached of chemical pulp, groundwood pulp, mechanical pulp, thermomechanical pulp or the like. Any of waste paper pulp such as bleached high-yield pulp, newspaper waste paper, magazine waste paper, cardboard waste paper, and deinked waste paper can be used.

To obtain the paper of the present invention, additives such as filler, dye, aluminum sulfate, dry paper strength improver, wet paper strength improver, retention improver and drainage improver are added to each paper type. You may use as needed in order to implement | achieve the required physical property. As the filler, heavy or light calcium carbonate is mainly used, but clay and talc are also used, and these may be used together. As the dry paper strength improver, anionic polyacrylamide-based polymer, cationic polyacrylamide-based polymer, amphoteric polyacrylamide-based polymer (each a copolymer of (meth) acrylamide mainly with other vinyl monomer, and so on) , Cationized starch, amphoteric starch, etc., which may be used alone or in combination. Examples of the wet paper strength improver include polyamide epichlorohydrin resin and the like. These may be used alone or in combination with an anionic polyacrylamide polymer. Examples of the yield improver include anionic or cationic high molecular weight polyacrylamide-based polymers, silica gel and cationized starch in combination, and bentonite and cationic high molecular weight polyacrylamide-based polymers in combination.

When used as a surface size, the coating amount on the surface of paper is 0.001 to 5 g per solid content of the sizing agent.
/ ^{M 2,} and preferably 0.002~1g / ^{m 2.} A size press, a gate roll coater, a bill blade coater, a calender, etc. are used for the coating device.

In the present invention, the surface coating liquid includes starches such as oxidized starch, phosphoric acid esterified starch, enzyme-modified starch, cationized starch and amphoteric starch, celluloses such as carboxymethyl cellulose, polyvinyl alcohols, and polyalcohols. It is also possible to mix and use acrylamides, water-soluble polymers such as sodium alginate, and inorganic salts such as sodium chloride and sodium sulfate in the coating liquid. Further, additives such as other surface sizing agent, anti-slip agent, antiseptic agent, rust preventive agent, defoaming agent, viscosity modifier, dye and pigment can be used in combination.

The paper of the present invention is not particularly limited, but various papers and paperboards can be mentioned.

In the case of making recycled paper containing high-quality paper, medium-quality paper, or deinked pulp and other waste paper pulp using calcium carbonate, the papermaking machine is easily soiled, and the present invention is effective.

The types of paper include milk carton base paper,
Base paper for liquid containers such as cup base paper, photographic paper base paper,
Gypsum board base paper, PPC paper, ink jet printing paper, laser printer paper, foam paper, thermal transfer paper, pressure bonding paper, heat-sensitive recording base paper, pressure-sensitive recording base paper, and other recording paper and its base paper, art paper, cast coated paper, high-quality coated paper Coated base paper such as, kraft paper, packaging paper such as pure white roll paper, other note paper, book paper, various printing paper,
Examples include various papers (paper) such as newsprint paper, paperboards for paper containers such as Manila balls, white balls and chip balls, and paperboards such as liners.

In particular, base papers for liquid containers such as milk carton base papers, cup base papers, etc., edge wick size papers such as photographic printing papers, and strong size degrees such as gypsum board base papers are required. In the papermaking of paper types, the sizing agent is added to the pulp slurry at a high ratio of 0.2% or more in terms of solid content% by weight with respect to the absolute dry pulp weight, so that the papermaking apparatus is easily soiled and the present invention is effective.

[0081]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In addition,% is based on weight unless otherwise specified. In the evaluation test of handmade paper, the amount of chemicals added represents the weight% per chemical solid content based on the pulp dry weight.

(Monomer (a) represented by the general formula (1)
Synthesis method of (Synthesis example 1) (2-propene-1-aminium, N,
N, N, 2-tetramethyl, chloride (PATMC)
Synthesis of 30% aqueous trimethylamine solution 147.7 in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel.
8 g (0.75 mol) was charged, and 45.28 g (0.50 mol) of 1-chloro-2-methyl-2-propene was slowly added dropwise at room temperature so that the reaction temperature did not exceed 40 ° C. After dropping, the mixture was reacted at 50 ° C. for 3 hours. After the reaction,
By removing the trimethylamine by distilling off the solvent, and then performing freeze-drying, 2-propene-1-aminium, N,
White powder of N, N, 2-tetramethyl, chloride 7
3.30 g (0.49 mol, yield 98%) was obtained. The obtained 2-propene-1-aminium, N, N, N,
2-Tetramethyl, chloride was analyzed by ¹ H NMR (40
The structure was confirmed by 0 MHz).

(Synthesis Example 2) (Synthesis of benzenemethanaminium, N, N-dimethyl-N- (2-methyl-2-propenyl), chloride (BMADMMPC)) A stirrer, a thermometer and a reflux condenser were provided. In a four-necked flask, N, N-dimethylbenzylamine 67.61 g
(0.50 mol) and 1-chloro-2-methyl-2-propene 45.28 g (0.50 mol) were dissolved in 2-propanol (112.88 g) and reacted at 80 ° C. for 10 hours. After the reaction was completed, the solvent was distilled off to remove 2-propanol, and thus 103.24 g (0.46 mol) of benzenemethanaminium, N, N-dimethyl-N- (2-methyl-2-propenyl), and a white powder of chloride. , Yield 9
5%) was obtained. The structure of the obtained benzenemethanaminium, N, N-dimethyl-N- (2-methyl-2-propenyl), chloride was confirmed by ¹ HNMR (400 MHz).

(Synthesis Example 3) (Synthesis of 2-propene-1-aminium, N, N, 2-trimethyl-N-octadecyl, chloride (PATMODC)) Composition and reaction conditions were changed as shown in Table 1. Was carried out in the same manner as in Synthesis Example 2, and the structure of the obtained product was ¹ H N
It was confirmed by MR (400 MHz).

(Synthesis Examples 4, 5, and 6) (2-propene-1
-Aminium, N-dodecyl, -N, N, 2-trimethyl, chloride (PADDTMC), 2-propene-1
-Aminium, N, N, 2-trimethyl-N-octyl, chloride (PATMOC), 2-propene-1-
Synthesis of aminium, N-hydroxyethyl-N, N, 2-trimethyl, chloride (PAHETMC)) The same procedure as in Synthesis Example 1 was repeated except that the composition and reaction conditions were changed as shown in Table 1, and the structure of the product was , ¹ H NMR (40
0 MHz).

[0086]

[Table 1]

Example 1 A 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube was charged with 30% 2-propene-1-aminium, N-dodecyl, N, N as a monomer (a). 2-
Trimethyl chloride (PADDTMC) aqueous solution 8
8.7 parts (3 mol%), 50% acrylamide aqueous solution 437.0 parts (97 mol%) were charged as the monomer (b), ion-exchanged water 448.5 parts were charged, and then the pH was adjusted with 25% sulfuric acid. Adjusted to 3.5. The temperature of this mixed liquid was raised to 60 ° C. under a nitrogen gas atmosphere while stirring. 25.8 parts of 10% 2,2′azobis (2-methylpropionamidine) · dihydrochloride aqueous solution as a polymerization initiator (0.3 mol% based on the total of the monomer (a) and the monomer (b))
Was added, and the temperature was raised to 80 ° C. and kept for 2 hours, then cooled to room temperature, and a polymer dispersant aqueous solution (P-
1) was obtained. The viscosity of the obtained polymer dispersant aqueous solution is 10
It was 90 mPa · s and pH was 4.9. A Brookfield viscometer was used to measure the viscosity at 25 ° C. Hereinafter, the viscosity measurement conditions were the same.

Example 2 A 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube was charged with 30% 2-propen-1-aminium, N-dodecyl, N, N as a monomer (a). 2-
Trimethyl chloride (PADDTMC) aqueous solution 12
9.1 parts (3 mol%), 50% acrylamide aqueous solution 555.3 parts (92 mol%) as monomer (b), and isobutyl methacrylate 30.2 parts (5 mol%) as monomer (d) were charged, and ion exchange was performed. 55.9 parts of water, 2-
After charging 361.7 parts of propanol, the pH was adjusted to 3.5 with 25% sulfuric acid. The temperature of this mixed solution was raised to 60 ° C. under a nitrogen gas atmosphere while stirring. 34.5 parts of 10% 2,2'azobis (2-methylpropionamidine) .dihydrochloride aqueous solution as a polymerization initiator (monomer (a)
And 0 for the sum of the monomer (b) and the monomer (d).
3 mol%) was added, the temperature was raised to 80 ° C., and the temperature was maintained for 3 hours. Then, 2-propanol was distilled off, ion-exchanged water was added, and the mixture was cooled to room temperature to obtain a polymer dispersant aqueous solution (P-2) having a solid content concentration of 25%. The obtained aqueous polymer dispersant solution had a viscosity of 2190 mPa · s and a pH of 5.0.

Example 3 In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, 25% 2-propene-1-aminium, N, N, N, 2-as the monomer (a) was added. Tetramethyl chloride (PATMC) aqueous solution 10.9 parts (0.
5 mol%), 385.7 parts (74.5 mol%) of a 50% aqueous acrylamide solution as the monomer (b), 71.1 parts (15 mol%) of itaconic acid as the monomer (c), and sodium styrenesulfonate 17.1 Part (2 mol%),
Cyclohexyl methacrylate 4 as monomer (d)
9.0 parts (8 mol%), 2-ethylhexyl mercaptopropionate as a chain transfer agent other than the monomers (a) to (d) 8.0 parts (1 mol relative to the total of the monomers (a) to (d)) %) And 5.2 parts of normal dodecyl mercaptan (0.7 mol% based on the total amount of the monomers (a) to (d)) and 10% 2-mercaptoethanol aqueous solution 19.9.
Parts (0.7 mol% with respect to the total of the monomers (a) to (d)) were charged, and 234.0 parts of ion-exchanged water and 361.7 parts of 2-propanol were charged. The temperature of this mixed solution was raised to 60 ° C. under a nitrogen gas atmosphere while stirring. 4.2 parts (0.7 mol% relative to the total amount of the monomers (a) to (d)) of azobisisobutyronitrile was added as a polymerization initiator, and the temperature was raised to 80 ° C. and maintained for 3 hours. Then, 2-propanol is distilled off, ion-exchanged water is added, the mixture is cooled to room temperature, and a polymer dispersant aqueous solution having a solid content concentration of 35% (P
-3) was obtained. The viscosity of the obtained polymer dispersant aqueous solution is 1
It was 830 mPa * s and pH was 4.7. A Brookfield viscometer was used to measure the viscosity at 25 ° C. Hereinafter, the viscosity measurement conditions were the same.

Examples 4 to 6 Polymer dispersant aqueous solution (P-4) having a solid content of 35% was prepared in the same manner as in Example 3 except that the kind of the monomer (a) was changed as shown in Table 2. (P-6) was obtained. Table 2 shows the physical properties of the resulting aqueous polymer dispersant solution.

Comparative Example 1 50 parts of styrene and 30 parts of methacrylic acid were placed in a pressure resistant flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube.
Parts, 10 parts of acrylic acid, 10 parts of lauryl acrylate, 1 part of ammonium persulfate and 225 parts of water with stirring,
Heated at 150 ° C. for 2 hours. Then cool to 60 ° C,
35.5 parts of 48.5% sodium hydroxide was slowly added dropwise, and the mixture was stirred for 30 minutes and then cooled to room temperature to give a solid content of 30%.
To obtain an aqueous polymer dispersant solution (RP-1). The resulting polymer dispersant aqueous solution pH 10.3, viscosity 510 mPa · s
Met.

[0092]

[Table 2]

Example 7 30% 2-propene-1-aminium, N-dodecyl, -N, N as monomer (a) was placed in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube. , 2
-Trimethyl chloride (PADDTMC) aqueous solution 1
2.8 parts (0.5 mol%), 50 as monomer (b)
% Acrylamide aqueous solution 324.9 parts (90.5 mol%), N, N-dimethyl-aminopropyl acrylamide 1 as monomer (c) (cationic monomer)
5.9 parts (4 mol%), 10.9 parts (4 mol%) of 80% methacrylic acid aqueous solution as monomer (c) (anionic monomer) and 4.0 parts (1 mol%) of sodium methallyl sulfonate, Charged with 588.4 parts of deionized water, 2
The pH was adjusted to 4.5 with 0% sulfuric acid. The temperature of this mixed solution was raised to 60 ° C. under a nitrogen gas atmosphere while stirring.
1% 2% ammonium persulfate aqueous solution as a polymerization initiator
4.4 parts (0 .. based on the total of monomers (a) to (c)).
(05 mol%), heated to 80 ° C., maintained for 3 hours,
Cooled to room temperature. Solid content concentration 20%, viscosity 350 mP
An aqueous polymer dispersant solution (P-7) having an pH of 4.2 was obtained.

Examples 8 to 13 The solid content concentration was 20% in the same manner as in Example 7 except that the composition of the monomers (a), (b) and (c) was changed as shown in Table 3. Polymer dispersant aqueous solution (P-8) ~
(P-13) was obtained. Table 3 shows the physical properties of the resulting aqueous polymer dispersant solution.

Comparative Example 2 In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, 335.7 parts (91 mol%) of a 50% aqueous acrylamide solution as a monomer (b) and a monomer (c). As the (cationic monomer), 16.2 parts (4 mol%) of N, N-dimethylaminopropylacrylamide, and as the monomer (c) (anionic monomer),
11.2 parts (4 mol%) of 80% methacrylic acid aqueous solution, 4.1 parts (1 mol%) of sodium methallylsulfonate, 2.6 parts of normaldodecyl mercaptan (monomer (b))
(0.5 mol% with respect to the total of (c)), 215.6 parts of ion-exchanged water and 199.8 parts of isopropyl alcohol were charged, and the pH was adjusted to 4.5 with 20% sulfuric acid. The temperature of this mixed solution was raised to 60 ° C. under a nitrogen gas atmosphere while stirring. As a polymerization initiator, 14.8 parts of a 2% ammonium persulfate aqueous solution (0.05 mol% based on the total amount of the monomers (b) and (c)) was added, and the temperature was raised to 80 ° C. and maintained for 3 hours. Next, isopropyl alcohol is distilled off,
Add ion-exchanged water and cool to room temperature to obtain a solid concentration of 20
%, A viscosity of 190 mPa · s, and a pH 4.2 of a polymer dispersant aqueous solution (RP-2) were obtained.

[0096]

[Table 3]

Example 14 110 parts of maleic anhydride was gradually added to 890 parts of gum rosin in a molten state at about 200 ° C., and the mixture was heated and kept at the same temperature for 3 hours to obtain a maleic anhydride-reinforced product of gum rosin.
The degree of strengthening of this reinforcement (the rate of addition of maleic anhydride) is 11
%Met. In a flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a water diverter, and a cooler, gum rosin 6 with an acid value of 170 was added.
00 parts and glycerin 56 parts (molar ratio charged: -OH / -C
OOH = 1.0) was charged, the mixture was heated to 270 ° C. under a nitrogen stream, and reacted at the same temperature for 15 hours with stirring to obtain a rosin esterified product having an acid value of 13.

Maleic anhydride fortified product of the above gum rosin 4
0 part and 60 parts of rosin esterified product are heated and melted to about 150 ° C., 6 parts of the polymer dispersant aqueous solution (P-1) is added and mixed with a solid content while stirring, and phase is added while further adding hot water to effect oil A water-in-water emulsion was prepared, and hot water was quickly added thereto to form a stable oil-in-water emulsion, which was then cooled to room temperature. The obtained rosin-based substance aqueous dispersion (E-1) had a solid content concentration of 40%, a viscosity of 48 mPa · s,
The average particle size was 0.43 μm. The average particle diameter is a median diameter, and was measured by a laser diffraction / scattering type particle size distribution device (manufactured by Horiba Ltd.). Hereinafter, the measurement conditions of the particle size were the same. Table 4 shows the physical properties of the obtained aqueous dispersion of the rosin-based substance. The obtained aqueous dispersion of the rosin-based substance can be used as it is as the sizing agent (E-1).

Examples 15 to 19 and Comparative Example 3 Solid content of 40% or 5 was obtained in the same manner as in Example 14 except that the polymer dispersant aqueous solution was changed as shown in Table 4.
An aqueous dispersion (E-2) to (E-2) of the rosin-based substance, which is 0%
-6) and (RE-1) were obtained. Table 4 shows the physical properties of the obtained aqueous dispersion of the rosin-based substance. The aqueous dispersion obtained in the same manner as in Example 14 was used as it was for the sizing agents (E-2) to (E).
-6) and (RE-1) can be used.

Mechanical Stability Test 1 50 g of sizing agents (E-1) to (E-6), (RE-1)) of rosin-based substances of Examples 14 to 19 and Comparative Example 3
Put in a cup, temperature 25 ℃, load 20kg, rotation speed 8
A Marlon stability test was performed at 00 rpm for 5 minutes.
The generated agglomerates were filtered through a 325 mesh wire mesh to measure the amount of precipitation with respect to the total solid content and expressed as a percentage. The results are shown in Table 4. The smaller the amount of precipitation, the better the mechanical stability.

[0101]

[Table 4]

Example 20 90 parts of fumaric acid was gradually added to 910 parts of gum rosin in a molten state at about 200 ° C., and the mixture was heated and kept at the same temperature for 3 hours to obtain a fumaric acid fortified product of gum rosin. The strengthening degree (fumaric acid addition rate) of this strengthened product was 9%. 100 parts of the fumaric acid fortified product of gum rosin was heated and melted to about 150 ° C., 6 parts of the polymer dispersant aqueous solution (P-1) was added and mixed in a solid content while stirring, and the phase was inverted while adding hot water. A water-in-oil emulsion was prepared, and hot water was quickly added to the emulsion to form a stable oil-in-water emulsion, which was then cooled to room temperature. The obtained rosin-based substance aqueous dispersion (E-7) had a solid content concentration of 40%, a viscosity of 44 mPa · s,
The average particle size was 0.32 μm. Table 5 shows the physical properties of the obtained aqueous dispersion of the rosin-based substance. The obtained aqueous dispersion of the rosin-based substance can be used as it is as a sizing agent (E-7).

Examples 21 to 25 and Comparative Example 4 Solid content of 40% or 5 was obtained in the same manner as in Example 20 except that the aqueous polymer dispersant solution was changed as shown in Table 5.
0% aqueous dispersion of rosin-based material (E-8) to (E
-12) and (RE-2) were obtained. Table 5 shows the physical properties of the obtained aqueous dispersion of the rosin-based substance. The aqueous dispersion obtained in the same manner as in Example 20 was used as it was for the sizing agent (E-8) to
It can be used as (E-12) and (RE-2).

Mechanical Stability Test 2 Sizing agents ((E-7) to (E-12), (RE-2)) 5 of each rosin-based substance of Examples 20 to 25 and Comparative Example 4
0 g was placed in a cup, and a Marlon-type stability test was performed at a temperature of 25 ° C., a load of 20 kg, and a rotation speed of 800 rpm for 5 minutes. The generated agglomerates were filtered through a 325 mesh wire mesh to measure the amount of precipitation with respect to the total solid content and expressed as a percentage. The results are shown in Table 5. The smaller the amount of precipitation, the better the mechanical stability.

[0105]

[Table 5]

Example 26 100 parts of a 2-oxetanone compound (alkylketene dimer using 95% stearic acid chloride as a raw material), 25 parts of an aqueous polymer dispersant solution (P-7) in solid content and 134 parts of ion-exchanged water were added. The mixture was heated to 70 ° C. and preliminarily dispersed by a homomixer, and then, while being kept at the same temperature, it was passed through a high-pressure discharge homogenizer twice at a shear pressure of 250 kg / cm ² to uniformly disperse the homogenizer. After adding 150 parts of ion-exchanged water and cooling to room temperature, ion-exchanged water was added so that the solid content of the aqueous dispersion was 20% to obtain an aqueous dispersion of a 2-oxetanone compound (E-13). The obtained aqueous dispersion of 2-oxetanone compound (E-13) had a solid content of 20.
%, Viscosity 12 mPa · s, pH 3.5, average particle size 0.
It was 75 μm. Table 6 shows the physical properties of the aqueous dispersion of the obtained 2-oxetanone compound. The resulting aqueous dispersion of the 2-oxetanone compound was used as it was for the sizing agent (E-1
It can be used as 3).

Example 27 100 parts of 2-oxetanone compound (alkylketene dimer using 95% stearic acid chloride as a raw material), and 25 parts and 4 parts by weight of an aqueous polymer dispersant solution solution (P-7) in solid content.
1.25 parts of 0% sodium naphthalene sulfonate / formaldehyde condensate and 134 parts of ion-exchanged water are heated to 70 ° C., preliminarily dispersed by a homomixer, and then 250 kg / c in a high pressure discharge homogenizer while maintaining the same temperature.
A shear pressure of m ² was passed twice to evenly disperse. After adding 150 parts of ion-exchanged water and cooling to room temperature, ion-exchanged water was added so that the solid content of the aqueous dispersion was 20%,
An aqueous dispersion (E-14) of the 2-oxetanone compound was obtained. Aqueous dispersion of the obtained 2-oxetanone compound (E
-14) is solid content 20%, viscosity 16 mPa · s, pH
The particle size was 3.6 and the average particle size was 0.77 μm. Obtained 2
Table 6 shows the physical properties of the aqueous dispersion of the oxetanone compound. The obtained aqueous dispersion of 2-oxetanone compound can be used as it is as a sizing agent (E-14).

Examples 28 to 33 A solid content of 20 was obtained in the same manner as in Example 27 except that the kind and the blending ratio of the polymer dispersant and the blending ratio of sodium naphthalenesulfonate / formaldehyde condensate were changed as shown in Table 6. % Aqueous dispersions (E-15) to (E-20) of the 2-oxetanone compound were obtained. However, the shearing pressure of the high-pressure discharge homogenizer was changed so that the average particle diameter was 0.7 to 0.8 μm, and the particles were dispersed. Obtained 2-
Table 6 shows the physical properties of the aqueous dispersion of the oxetanone compound.
The resulting aqueous dispersion of the 2-oxetanone compound can be used as it is as the sizing agents (E-15) to (E-20).

Comparative Example 5 100 parts of a 2-oxetanone compound (an alkyl ketene dimer prepared from 95% stearic acid chloride as a raw material) was preliminarily gelatinized at 90 ° C. for 1 hour with a 5% aqueous solution of cationized starch (substitution degree 0.04). Portion of cationized potato starch containing quaternary ammonium salt of 4), 40% aqueous solution of sodium naphthalenesulfonate / formaldehyde condensate 3
After heating to 75 ° C and pre-dispersing with a homomixer, the 2 parts were added to a high-pressure discharge homogenizer while maintaining the same temperature.
A shear pressure of 50 kg / cm ² was passed twice to uniformly disperse. After adding 150 parts of ion-exchanged water and cooling to room temperature, ion-exchanged water was added so that the aqueous dispersion had a solid content of 20%, and an aqueous dispersion of the 2-oxetanone compound (RE
-3) was obtained. Table 6 shows the physical properties of the aqueous dispersion of the obtained 2-oxetanone compound. The obtained aqueous dispersion of the 2-oxetanone compound can be used as it is as a sizing agent (RE-3).

Dispersion stability test Sizing agents ((E-13) to (E-20), (R) of 2-oxetanone compounds of Examples 26 to 33 and Comparative Example 5 respectively.
E-3)) shows the viscosity after storage at 32 ° C. for 1 month. The results are shown in Table 6. The smaller the change in viscosity immediately after production and after storage for 1 month, the better the dispersion stability.

[0111]

[Table 6]

Example 34 Substituted cyclic dicarboxylic acid anhydride (alkenyl succinic anhydride made from a mixture of 10% hexadecene and 90% octadecene) and an aqueous polymer dispersant solution (P-7) were used as a solid content weight ratio of 100 /. The mixture was mixed so as to be 20 and the mixture was injected into a high-shear rotary emulsifier (Ebara Seisakusho Ebara Milder) having a stator and a rotor at a flow rate of 200 ml / min for continuous treatment. Then, it was diluted with water so that the concentration of the substituted cyclic dicarboxylic acid anhydride was 1% to obtain an aqueous dispersion (E-21) of the substituted cyclic dicarboxylic acid anhydride. The particle diameter of the obtained aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride was 0.64 μm. The resulting aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride is used as it is for the sizing agent (E
-21).

Examples 35 to 40, Comparative Example 6 Substitution in which the concentration of the substituted cyclic dicarboxylic acid anhydride was 1% in the same manner as in Example 34 except that the copolymer solution was changed as shown in Table 7. Aqueous dispersions (E-22) to (E-27) and (RE-4) of cyclic dicarboxylic acid anhydride were obtained.
Table 7 shows the physical properties of the resulting aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride. The resulting aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride is used as it is for the sizing agents (E-22) to (E-
27) and (RE-4).

Comparative Example 7 10 parts of a substituted cyclic dicarboxylic acid anhydride (alkenyl succinic anhydride made from a mixture of 10% hexadecene and 90% octadecene) was pregelatinized at 90 ° C. for 1 hour 1
An aqueous dispersion (RE-5) was obtained by treating 150 parts of an aqueous solution of 0% cationized starch (Kate 15 manufactured by NSC Japan) with a universal homogenizer (manufactured by Nippon Seiki Seisakusho) at 15,000 rpm for 3 minutes. It was Further, ion-exchanged water was added and diluted so that the concentration of the substituted cyclic dicarboxylic acid anhydride was 1% to obtain an aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride. Table 7 shows the physical properties of the resulting aqueous dispersion of the substituted cyclic dicarboxylic acid anhydride.

[0115]

[Table 7]

Using the various aqueous dispersions obtained in the above-mentioned Examples and Comparative Examples (hereinafter sometimes referred to as sizing agent only), the following hand plow test was conducted. Example 41 A bleached kraft pulp (mixed pulp having a pulp ratio of hardwood to softwood of 9: 1) beaten to 400 Canadian Standard Freeness was made into a slurry of 2.5%, and calcium carbonate of pulp to 2% ( Okutama Kogyo TP121S) was added. In addition, 1% sulfuric acid band to pulp, 0.5% amphoteric starch to pulp (Japan N
SC Cato 3210) and 0.35% of pulp to the rosin-based sizing agent (E-1) were sequentially added, and the pulp slurry was diluted to a concentration of 0.25% with dilution water having a pH of 7.5. . Then, the diluted pulp slurry contained 5% of calcium carbonate in the pulp (Okutama Kogyo T
P121S), talc 3% with respect to pulp (manufactured by Nippon Talc), yield improver 0.01% with respect to pulp (Himo N
R12MLS) was added, the papermaking pH was 7.5, and the paper was made to a basis weight of 65 g / m ² using a Noble and Wood paper machine, and then 100 using a drum dryer.
Paper was obtained by drying at 80 ° C. for 80 seconds. The obtained paper was conditioned under a constant temperature and constant humidity (23 ° C., 50% relative humidity) environment for 24 hours, and then the Steckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 8. In addition, this hand plow test is conducted in a system using calcium carbonate as a filler, for example, neutral printing writing paper, neutral coated base paper, neutral P
This corresponds to the condition for making PC paper, neutral inkjet paper, and neutral information paper.

Examples 42 to 46, Comparative Example 8 Sizing agents ((E-2) to (E-6), (RE) of rosin-based materials were used instead of the sizing agents (E-1) of rosin-based materials.
A test paper was obtained in the same manner as in Example 35 except that -1)) was used. The test paper obtained is kept at a constant temperature and humidity (23 ° C, 50%
After conditioning the humidity for 24 hours under the (relative humidity) environment, the Stoeckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 8.

[0118]

[Table 8]

Example 47 A bleached kraft pulp (mixed pulp having a pulp ratio of hardwood to softwood of 4: 1) beaten to 350 Canadian Standard Freeness was made into a slurry of 2.5%, and to this pulp 1.5 % Sulfuric acid band, and 0.2% of pulp to the rosin-based sizing agent (E-7)
Was sequentially added, and the pulp slurry was diluted to a concentration of 0.25% with dilution water having a pH of 4.5. Then, to the diluted pulp slurry, talc 10% to pulp (manufactured by Nippon Talc) and yield improver 0.01% to pulp (NR12MLS manufactured by Himo) were added, and the papermaking pH was 4.5, and noble and wood papermaking. Using a machine, basis weight 65 g / m ²
After making paper so that
Paper was obtained by drying at 00 ° C. for 80 seconds. The obtained paper was conditioned under a constant temperature and constant humidity (23 ° C., 50% relative humidity) environment for 24 hours, and then the Steckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 9. In addition, this hand plow test is an acidic system, for example, acidic printing writing paper,
It corresponds to the conditions for making acidic coated base paper, acidic PPC paper, acidic inkjet paper and acidic information paper.

Examples 48 to 52, Comparative Example 9 Sizes of rosin-based substances ((E-8) to (E-12), (R
A paper was obtained in the same manner as in Example 39 except that E-2)) was used. The obtained paper was conditioned under a constant temperature and constant humidity (23 ° C., 50% relative humidity) environment for 24 hours, and then the Steckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 9.

[0121]

[Table 9]

Example 53 Pulp beaten to 400 Canadian Standard Freeness (a mixed pulp having a pulp ratio of hardwood to softwood of 9: 1) was made into a slurry of 2.5%, and 20% of calcium carbonate to pulp was added thereto. (TP121 made by Okutama Kogyo
S) was added. To this, a sulfuric acid band containing 0.5% of pulp and an amphoteric starch containing 1.0% of pulp (Kate 3210 manufactured by NSC Japan) were sequentially added. Then, after diluting the pulp slurry to a concentration of 0.25% with diluted water having a pH of 8.0, the sizing agent (E-13) for the 2-oxetanone compound was 0.15% with respect to the pulp, and 0.01% with respect to the pulp. Yield improver (NR12MLS manufactured by Himo) was added sequentially,
The papermaking pH was 8.0, papermaking was carried out using a Noble and Wood papermaking machine to a basis weight of 70 g / m ^2, and dried at 100 ° C. for 80 seconds using a drum dryer to obtain paper. The obtained test paper was conditioned for 24 hours in a constant temperature and constant humidity (23 ° C., 50% relative humidity) environment, and then the Steckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 10. Note that this hand plow test corresponds to the conditions for making, for example, neutral printing writing paper, neutral coated base paper, neutral PPC paper, neutral inkjet paper and neutral information paper in a system using calcium carbonate as a filler. .

Examples 54 to 60, Comparative Example 10 Instead of the sizing agent of the 2-oxetanone compound (E-13), the sizing agent of the 2-oxetanone compound ((E-1
Papers were obtained in the same manner as in Example 53 except that 4) to (E-20) and (RE-3)) were used. The obtained paper was conditioned under a constant temperature and constant humidity (23 ° C., 50% relative humidity) environment for 24 hours, and then the Steckigt sizing degree was measured according to JIS P-8122. The results are shown in Table 10.

[0124]

[Table 10]

Example 61 Pulp beaten to 250 Canadian Standard Freeness (a mixed pulp having a ratio of deinked pulp to hardwood bleached kraft pulp of 7: 3) was made into 2.5% slurry, to which pulp 10 was added. % Calcium carbonate (TP121S manufactured by Okutama Kogyo Co., Ltd.) was added. To this, a sulfuric acid band containing 0.5% of pulp and an amphoteric starch containing 1.0% of pulp (Kate 3210 manufactured by NSC Japan) were sequentially added.
Then, this pulp slurry was diluted to a concentration of 0.25% with diluting water having a pH of 7.0, and then a sizing agent (E-21) of a substituted cyclic dicarboxylic acid anhydride having a pulp content of 0.1%, and a pulp content of 0.02. % Yield improver (HYMO NR12ML
S) are sequentially added, and the paper is made to have a basis weight of 65 g / m ² using a Noble and Wood paper machine at paper making pH 7.0, and dried at 80 ° C. for 100 seconds using a drum dryer to obtain paper. It was The obtained paper is kept at constant temperature and humidity (23 ° C, 5
After controlling the humidity for 24 hours in an environment (0% relative humidity), the Steckigt sizing degree was measured according to JIS P-8122.
The results are shown in Table 11. This hand plow test is conducted in a system using calcium carbonate as a filler, for example, recycled printing writing paper, neutral coated base paper, neutral neutral paper, recycled PPC.
This corresponds to the conditions for making paper, recycled inkjet paper, and recycled information paper.

Examples 62 to 68, Comparative Examples 11 and 12 Instead of the sizing agent for the substituted cyclic dicarboxylic acid anhydride (E-21), the sizing agent for the substituted cyclic dicarboxylic acid anhydride ((E
-22) to (E-27), (RE-4), (RE-
Paper was obtained in the same manner as in Example 51 except that 5)) was used. Constant temperature and humidity (23 ℃, 50% relative humidity)
After conditioning the humidity for 24 hours in an environment,
It measured according to ISP-8122. The results are shown in Table 1.
Shown in 1.

[0127]

[Table 11]

[0128]

INDUSTRIAL APPLICABILITY According to the present invention, the polymer dispersant of the present invention can be used, for example, as a rosin-based substance, a 2-oxetanone compound,
When used in the production of an aqueous dispersion of a substituted cyclic dicarboxylic acid anhydride, it is possible to obtain a sizing agent which is an aqueous dispersion having excellent dispersion stability and mechanical stability. By adding a small amount of this sizing agent, paper showing a good sizing effect can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D21H 17/62 D21H 17/62 21/16 21/16 (72) Inventor Sone Narihiko Midori-ku, Chiba-shi, Chiba 2-33 Onodai F-Term in Japan PMC Co., Ltd. (reference) 4J100 AB02S AB03S AB07R AB16S AJ01R AJ02R AJ08R AL03S AL05S AL34S AM15Q AM15S AM21R AN05P AP01R BA03P BA55R BB01P BC43P BC79P CA04 CA50 AG40 JA41 CA50 CA40 JA41 CA55 CA40 AG72 AG89 AH12 AH33 EA30 FA17 FA22 GA05 GA22 GA32 GA34

Claims (9)

[Claims] 1. A polymer dispersant comprising a monomer (a) represented by the following general formula (1) and a monomer (b) below. (A) General formula (1) Wherein, ^{R 1} represents an alkylene group having 1 to 4 carbon ^atoms, R 2 to R
⁴ is a hydrogen atom or 30 carbon atoms which may have a substituent
The following alkyl groups are shown (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms). X ^-
Represents an anion of an inorganic acid or an organic acid. ] The compound shown by these, (b) (meth) acrylamide 2. A monomer (a) represented by the following general formula (1), the following monomer (b), and the following monomer (c) and / or the following monomer (d) are polymerized. Polymer dispersant. (A) General formula (1) Wherein, ^{R 1} represents an alkylene group having 1 to 4 carbon ^atoms, R 2 to R
⁴ is a hydrogen atom or 30 carbon atoms which may have a substituent
The following alkyl groups are shown (provided that any two or three of R ^{2 to} R ⁴ are hydrogen atoms). X ^-
Represents an anion of an inorganic acid or an organic acid. ] The compound shown by these, (b) (meth) acrylamide, (c)
Ionic monomer (d) hydrophobic monomer except monomer (a) represented by the general formula (1) 3. An aqueous dispersion comprising the polymer dispersant according to claim 1 or 2, a hydrophobic compound and water. 4. The hydrophobic compound is at least one selected from the group consisting of rosin-based substances, 2-oxetanone compounds, and substituted cyclic dicarboxylic acid anhydrides.
The aqueous dispersion described. 5. A high shear rotary emulsifier or a high pressure discharge homogenizer is used to mix the polymer dispersant according to claim 1 or 2, the hydrophobic compound and water under high shear. The aqueous dispersion according to claim 3 or 4. 6. The aqueous dispersion according to claim 3, wherein the aqueous dispersion is a sizing agent. 7. Paper obtained by using the sizing agent according to claim 6. 8. The paper according to claim 7, which is high-quality paper, medium-quality paper or recycled paper containing calcium carbonate. 9. The paper according to claim 7, which is a base paper for liquid containers, a base paper for photographic printing paper, and a base paper for gypsum board.