JP2936250B2 - Manufacturing method of high gloss coated paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high gloss coated paper, and more particularly to a method for producing a coated paper having excellent white gloss, whiteness and printability.

[0002]

2. Description of the Related Art Recently, as a method for producing a coated paper having a high gloss, a paper coating paint using a fine-grained inorganic pigment as a pigment and greatly increasing the amount of a binder has been used. A method (Japanese Unexamined Patent Publication No. 3-241095) has been proposed.

[0003]

However, the above method is
Due to the large amount of binder used, uneven binder distribution on the coating layer surface due to binder migration is unavoidable. As a result, despite the use of fine-grained inorganic pigments as pigments, Significant improvement in gloss could not be expected.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a method for producing a coated paper having a high gloss, and as a result, a pigment containing plastic pigment has been used, and binder migration has occurred as a binder. It has been found that a coated paper excellent in gloss can be obtained by using a so-called thermosensitive gelling latex which is difficult to achieve, and the present invention has been achieved.

That is, the present invention relates to a method for preparing a plastic pigment (A) other than an ethylene polymer by at least 10% by weight.
The pigment composition containing, and the emulsifier amount of the aqueous phase is 0.01 mm
ol / g (resin) or less and a binder composed of a resin latex (B) and a vinyl polymer (C) whose hydrophilicity and hydrophobicity change reversibly at a certain temperature as a boundary. And a high gloss coated paper obtained by applying this paint to paper.

[0006] The plastic pigment (A) in the present invention is a plastic or polymer bead. (A) may be either thermoplastic or thermosetting. Examples of the thermoplastic polymer beads include styrene-based (polystyrene, styrene / butadiene copolymer, etc.) and acrylic [alkyl (meth) acrylate (co) polymer, acrylic / styrene copolymer, etc.]. Examples of the thermosetting polymer beads include those of an epoxy resin type (a cured product of an epoxy resin and an amine).

The above (A) usually has a particle diameter of 100 to 10
00 nm spherical or non-spherical, solid, hollow or core-shell beads.

The above (A) may be colored with a pigment or dye.

[0009] Of (A), those having a glass transition temperature of 50 to 150 ° C are preferred because calendar stains during calendering or cast drum stains in the cast coating method hardly occur.

Here, the glass transition temperature is determined by measuring with a differential scanning calorimeter (DSC) under nitrogen at 20 ° C./min.

The pigment other than (A) in the pigment composition of the present invention is not particularly limited, and various clays, kaolin, calcium carbonate, satin white, titanium oxide, aluminum hydroxide, barium sulfate, zinc oxide, sulfuric acid One or more known pigments used in paper coating paints such as calcium and talc are exemplified.

The content of (A) in the pigment composition is usually at least 10% by weight, preferably 3% by weight, based on the composition.
0 to 80% by weight. If it is less than 10% by weight, the gloss becomes insufficient.

The amount of the emulsifier in the aqueous phase in the resin latex (B) constituting the binder in the present invention is 0.01.
mmol (mmol) / g (resin) or less, preferably
It is necessary to be 0.002 mmol / g or less.
When the amount of the emulsifier in the aqueous phase exceeds 0.01 mmol / g, the effect of the vinyl polymer (C) that the hydrophilicity and hydrophobicity reversibly change at a certain temperature as a boundary is inhibited, and as a result, It becomes difficult to obtain a coated paper binder composition which gives a coated paper with high gloss and good printability. The amount of the emulsifier in the aqueous phase is represented by the weight of the resin component in the resin latex (B).

The amount of the emulsifier in the aqueous phase can be determined by analyzing and quantifying the aqueous phase obtained by removing the resin component from the resin latex by liquid chromatography or the like. As a method of removing the resin component from the resin latex, for example, a method of removing the resin component by coagulating and solidifying the resin component after freezing the resin latex, a method of removing the resin component by sedimentation and solidification by a centrifugal separator, an acid or an alkali. In addition, a method of removing and solidifying and removing the resin component may be used.

As a method for producing a resin latex in which the amount of an emulsifier in an aqueous phase is 0.01 mmol / g or less, for example,
A method of emulsion polymerization of a monomer using an emulsifier having low solubility in water, a method of emulsion polymerization using an emulsifier having a radical polymerizable group, a method of emulsion polymerization using a water-soluble polymer as a protective colloid, an organic solvent After synthesizing a polymer obtained by (co) polymerizing an ion-forming monomer therein, neutralizing the obtained polymer with an acid or alkali, adding water, emulsifying the polymer, and removing the solvent.

Among these methods, an emulsion polymerization method is preferable in that a latex composed of a high molecular weight resin is obtained, and an emulsifier having a radical polymerizable group (SBR latex is preferable in that an SBR latex is easily obtained under ordinary conditions). Emulsion polymerization using a) is particularly preferred.

Emulsifiers having low solubility in water include HL
B value of 3 to 9, for example, amine or alkali metal salt of a fatty acid having 22 or more carbon atoms, ethylene oxide 1 to 6 of an aliphatic or aromatic alcohol having 15 or more carbon atoms
And a molar adduct.

An emulsifier (a) having a radical polymerizable group;
For example, the following may be mentioned. (1) Anionic (meth) acrylates, the following formula
And the like indicated by: CH₂= C (R³) CO₂(CH₂) MSO₃M CH₂= C (R³) CO₂CH₂C (R⁴) (OCOR)
⁵) CH₂SO₃M CH₂= C (R³) CO₂CH₂CH₂OCOArCO
₂CH₂CH₂OSO₃M CH₂= C (R³) CO₂(AO) pSO₃M (where R³Is a hydrogen atom or a methyl group, m is 1 to 4
Integer, M is alkali metal ion, ammonium ion
Or aminium ion, R⁴Is a hydrogen atom or methyl
Group, R⁵Is an alkyl group or alkenyl having 7 to 21 carbon atoms
Group, Ar is an aromatic ring or an aliphatic ring, AO has 2 carbon atoms
An oxyalkylene group of 4 to 4, p represents an integer of 2 to 30
You. (2) anionic allyl compounds represented by the following formula:
Etc .: CH₂= CHCH₂OCOCH (SO₃M) CH₂CO
₂R⁵  CH₂= CHCH₂OCH₂CH (OH) CH₂OCO
CH (SO₃M) CH₂CO₂R⁵  (R⁶) (R⁷) Ar (CH₂CH = CH₂) O (A
O) qSO₃M (where M is an alkali metal ion, an ammonium ion
Or an aminium ion, R⁵Is an alkyl having 7 to 21 carbon atoms
A kill or alkenyl group, R⁶Represents a group having 4 to 18 carbon atoms.
Alkyl group, alkenyl group or aralkyl group, R⁷Is water
An atom or an alkyl group having 4 to 18 carbon atoms, alkenyl
Group or aralkyl group, Ar is an aromatic ring, AO is carbon number
2 to 4 oxyalkylene groups, q is an integer of 2 to 200
Show. (3) anionic maleic esters represented by the following formula:
Things: R⁸OCOCH = CHCO₂CH₂CH (OH) CH₂
SO₃M R⁹O (AO) qCOCH = CHCO₂(CH₂) RC
H (R¹⁰) SO₃M R⁹(AO) qOCOCH = CHCO₂M (where R⁸Is an alkyl group having 5 to 21 carbon atoms, alkenyl
Or an aralkyl group, M is an alkali metal ion,
Ammonium ion or aminium ion, R⁹And R
¹⁰Is an alkyl group having 1 to 21 carbon atoms, an alkenyl group or
Represents an aralkyl group, and AO represents an oxyalkylene having 2 to 4 carbon atoms.
And q represents an integer of 2 to 200, and r represents an integer of 0 to 3.
You. (4) anionic itaconic esters represented by the following formula:
Thing: CH₂= C (CH₂CO₂R⁸) CO₂(CH₂) MS
O₃M CH₂= C (CH₂CO₂R⁸) CO₂CH₂CH (O
H) CH₂SO₃M (where R⁸Is an alkyl group having 5 to 21 carbon atoms, alkenyl
M or an aralkyl group, m is an integer of 1-4, M is
Li metal ion, ammonium ion or aminium ion
Indicates ON. (5) Nonionic (meth) acrylates, the following formula
And the like indicated by: CH₂= C (R³) CO (AO) qOR⁸  CH₂= C (R³) CO (PO) q (EO) sOH or
Is CH₂= C (R³) CO (EO) q (PO) sOH (where R³Is a hydrogen atom or a methyl group, R⁸Is the carbon number
5 to 21 alkyl groups, alkenyl groups or aralkyl
AO is an oxyalkylene group having 2 to 4 carbon atoms, q is 2
An integer of ~ 200, PO is an oxypropylene group, EO is
A xyethylene group, s represents an integer of 2 to 200. (6) Nonionic allyl compounds represented by the following formula:
Etc .: (R⁶) (R⁷) Ar (CH₂CH = CH₂) O (A
O) qH (where R⁶Is an alkyl group having 4 to 18 carbon atoms, alkenyl
Or an aralkyl group, R⁷Is a hydrogen atom or carbon number
4-18 alkyl, alkenyl or aralkyl
Group, Ar is an aromatic ring, AO is an oxyalkyl having 2 to 4 carbon atoms.
A kylene group and q represents an integer of 2 to 200. (7) Nonionic maleic esters represented by the following formula:
Things: R⁶(AO) qOCOCH = CHCO₂(AO) sR⁷  (Where R⁶Is an alkyl group having 4 to 18 carbon atoms, alkenyl
Or an aralkyl group, R⁷Is a hydrogen atom or carbon number
4-18 alkyl, alkenyl or aralkyl
Group, AO is an oxyalkylene group having 2 to 4 carbon atoms, q and
s shows the integer of 2-200. (8) Nonionic itaconic esters represented by the following formula:
Thing: CH₂= C [CH₂CO₂(AO) qR⁶] CO₂(A
O) sR⁷  (Where R⁶Is an alkyl group having 4 to 18 carbon atoms, alkenyl
Or an aralkyl group, R⁷Is a hydrogen atom or carbon number
4-18 alkyl, alkenyl or aralkyl
Group, AO is an oxyalkylene group having 2 to 4 carbon atoms, q and
s shows the integer of 2-200. (9) Cationic (meth) acrylates, the following formula
Etc .: [CH₂= C (R³) COOCH₂CH (OH) CH₂
N (R¹¹)₃] X (where R³Is a hydrogen atom or a methyl group, R¹¹Is carbon
An alkyl group, an alkenyl group or an aralkyl
And X represents a halogen atom. (10) Cationic allyl compounds represented by the following formula:
Etc .: [CH₂= CHCH₂CH (OH) CH₂N (CH₃)
₂R¹¹] X [CH₂= CHCH₂N (CH₃)₂R¹¹] X (where R¹¹Is an alkyl group having 4 to 21 carbon atoms,
X represents a halogen atom or a aralkyl group;
You. )

Among them, (1), (5) and (5) are preferred in that they have good copolymerizability with various monomers, especially with styrene.
(9) is preferable, and (1) to (4) are preferable in that they are hardly agglomerated by a pigment dispersant [for example, sodium poly (meth) acrylate] used in ordinary paper coating paints. preferable. Among (1), (meth) acrylates having an anionic group and a polyoxypropylene chain are particularly preferred.

The amount of (a) used when producing the resin latex is usually 0.1 to 20% by weight based on the resin content.

The resin constituting the resin latex (B) in the present invention is a (co) polymer of various monomers. The monomer is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, glycidyl (meth) Acrylates, N, N-dibutyl (meth) acrylamide, N
-Cyclohexyl (meth) acrylamide, (meth) acrylonitrile, styrene, 1-methylstyrene, vinyl acetate, vinyl alcohol, butadiene, vinyl chloride,
Isoprene, chloroprene, hydroxyethyl (meth)
Acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acryloyloxy polyglycerol, vinyl alcohol, allyl alcohol, (meth) acrylamide, N-methyl (meth) acrylamide, N
-Methylol (meth) acrylamide, N-vinyl-2
-Pyrrolidone, vinylimidazole, N-methylol-
ε-caprolactam, N-methylolmaleimide, N-
Vinyl succinimide, p-aminostyrene, N-vinyl carbazole, 2-vinyl pyridine, 2-cyanoethyl (meth) acrylate, (meth) acrylic acid, (anhydride) maleic acid, fumaric acid, itaconic acid, vinyl sulfonic acid, (meth) ) Acrylic sulfonic acid, styrene sulfonic acid, vinyl benzoic acid, alkyl allyl sulfosuccinic acid,
(Meth) acryloyl polyoxyalkylene sulfate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylamino Propyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, vinylaniline, 1,1,1-trimethylamine (meth) acrylimide, 1,1-dimethyl-1-
Ethylamine (meth) acrylimide, 1,1-dimethyl-1- (2′-phenyl-2′-hydroxyethyl)
Examples include amine (meth) acrylimide, 1,1,1-trimethylamine (meth) acrylimide, and the like, and combinations thereof.

The resin latex (B) is preferably a latex of styrene-butadiene resin, styrene-acrylic resin, acrylic resin, vinyl acetate resin or ethylene-vinyl acetate resin.
Butadiene resin latex is preferred.

The resin content of the resin latex (B) is usually 2
0-75%, preferably 40-60%.

In producing the resin latex (B),
Known polymerization initiators and chain transfer agents are used. Examples of the polymerization initiator include organic polymerization initiators (peroxides (cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, benzoyl peroxide, lauroyl peroxide, etc.), azo compounds (azobisisobutyrate). Lonitrile, azobisisovaleronitrile, etc.), inorganic polymerization initiators [persulfates (sodium persulfate, ammonium persulfate,
Potassium persulfate, etc.) and the like. The amount of the polymerization initiator to be used is usually 0.01 to 5% by weight based on the resin component.

In the production of the resin latex (B), a known chain transfer agent can be used for the purpose of adjusting the molecular weight of the resin, the gel content of the latex, and the like. Examples of the chain transfer agent include α-methylstyrene dimer (2,4-diphenyl-4-methyl-1-pentene and the like), terpinolene, terpinene, dipentene, an alkyl mercaptan having 8 to 18 carbon atoms, and an alkylene having 8 to 18 carbon atoms. Dithiol, alkyl thioglycolate, dialkylxanthogen disulfide, tetraalkylthiuram disulfide, carbon tetrachloride, and the like. These can be used alone or in combination of two or more. The amount of the chain transfer agent to be used is generally the same as the amount of the monomer 10 constituting the resin in (B).
0 to 15 parts by weight with respect to 0 parts by weight.

The reducing agent [sodium pyrobisulfite,
Sodium sulfite, sodium hydrogen sulfate, ferrous sulfate,
Glucose, sodium formaldehyde sodium sulfoxylate, L-ascorbic acid (salt)], chelating agents (glycine, alanine, sodium ethylenediaminetetraacetate, etc.), pH buffers (sodium tripolyphosphate, potassium tetrapolyphosphate, etc.). You may make it contain during manufacture of (B).

The vinyl polymer (C) whose hydrophilicity and hydrophobicity are reversibly changed at a certain temperature as a boundary in the present invention is such that when an aqueous solution or aqueous suspension thereof is heated, it gels sharply. Preferred are, for example, a polymer (C1) comprising a vinyl carboxylic acid ester (b) of an alkylene oxide adduct of a cyclic amine or an acyclic amine having 5 or more carbon atoms, an N-alkyl or N-alkylene (meth) acrylamide. Polymer (C2), polymer (C3) composed of polyalkylene glycol monoalkyl ether mono (meth) acrylate or polyalkylene glycol monophenyl ether mono (meth) acrylate, polymer (C4) composed of polyethylene glycol monoalkyl monovinyl ether And polyethylene glycol monoph Polymers consisting of sulfonyl monovinyl ether (C5), and the like. Among these, a high effect of suppressing the transfer of the resin latex particles to the surface of the paint for paper coating during heating and drying is high, and a coated paper having high air permeability and good blister resistance is obtained. Polymer (C
1) is preferred.

The cyclic amine in the vinyl carboxylic acid ester (b) is not particularly limited as long as it is a cyclic amine having an active hydrogen for the addition of an alkylene oxide, and thus has an amine nitrogen inside and outside the ring. Just do it. The active hydrogen group may be derived from an amino group, or may be derived from any group to which an alkylene oxide can be added, such as a hydroxyl group or a carboxyl group.

Examples of such a cyclic amine include, for example,
Non-aromatic heterocyclic amine [having an aziridine ring (aziridine, 2-methylaziridine, 2-
Those having a pyrrolidine ring (e.g., pyrrolidine, 2-methylpyrrolidine, 2-ethylpyrrolidine, 2-pyrrolidone, succinimide, 1,2-cyclohexanedicarboximide), and those having a piperidine ring (piperidine, 2- Methylpiperidine,
3,5-dimethylpiperidine, 2-ethylpiperidine,
4-piperidinopiperidine, 2-methyl-4-pyrrolidinopiperidine, ethylpicoliconate, etc., those having a piperazine ring (1-methylpiperazine, 1-methyl-3-ethylpiperazine, etc.), and a morpholine ring (Morpholine, 2-methylmorpholine, 3,
5-dimethylmorpholine, thiomorpholine, etc.),
Pyrolines (such as 3-pyrroline, 2,5-dimethyl-3-pyrroline, 2-phenyl-2-pyrroline), pyrazolines (such as pyrazoline), imidazoles (2-methylimidazole, 2-ethyl-4-methylimidazole) ,
2-phenylimidazole, pyrazoles (pyrazole, pyrazolecarboxylic acid, etc.), pyridones (α
-Pyridone, [gamma] -pyridone, etc.) and [epsilon] -caprolactam, pyridazinone, pyridalin, pyridoin, etc.]; aromatic heterocyclic amines [2-hydroxypyridine, 2-hydroxy-3,5-ditert-butylpyridine, 2-carboxyl] Pyridine, 4-pyridylcarbinol, 2-hydroxypyrimidine, pyrrole, 2-phenylpyrrole, etc.]; aromatic amines [aniline, 3-methylaniline, N-methylaniline, N-
Isopropylaniline and the like].

Of these cyclic amines, preferred are non-aromatic cyclic amines. Of these, those having a piperidine ring and those having a morpholine ring are most preferable, and those having a morpholine ring are most preferable.

The non-cyclic amine having 5 or more carbon atoms in (b) is not particularly limited as long as it is a non-cyclic amine having 5 or more carbon atoms having an active hydrogen for adding an alkylene oxide. For example, primary aliphatic acyclic amines having 5 or more carbon atoms (dimethylpropylamine, 2-ethylbutylamine, pentylamine, 2,2-dimethylbutylamine,
Hexylamine, cyclohexylamine, octylamine, 2-ethylhexylamine, isodecylamine, laurylamine, etc.), a secondary aliphatic acyclic amine having 5 or more carbon atoms [methylbutylamine, methylisobutylamine, methyl tert-butylamine, methyl Pentylamine, methylhexylamine, methyl (2-ethylhexyl) amine, methyloctylamine, methylnonylamine, methylisodecylamine, ethylpropylamine, ethylisopropylamine, ethylbutylamine,
Ethyl isobutylamine, ethyl tert-butylamine, ethylpentylamine, ethylhexylamine, ethyl (2-ethylhexyl) amine, ethyloctylamine, dipropylamine, diisopropylamine, propylbutylamine, propylisobutylamine, propyltertiarybutylamine, propylpentylamine ,
Propylhexylamine, propyl (2-ethylhexyl) amine, propyloctylamine, isopropylbutylamine, isopropylisobutylamine, isopropyltert-butylamine, isopropylpentylamine, isopropylhexylamine, isopropyl (2
-Ethylhexyl) amine, isopropyloctylamine, dibutylamine, diisobutylamine, ditertiarybutylamine, butylpentylamine, dipentylamine, dicyclohexylamine, etc.].

Preferred among the acyclic amines having 5 or more carbon atoms are primary aliphatic acyclic amines having 5 to 8 carbon atoms.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide and the like. Preferred among these are ethylene oxide or propylene oxide, and combinations of both.

The number of moles of the alkylene oxide added is generally 1 to 50 mol, preferably 1 to 5 mol.

(B) is a cyclic amine or a compound having 5 carbon atoms.
An ester of the above alkylene oxide adduct of an acyclic amine with a vinyl carboxylic acid. The vinyl carboxylic acid does not need to have a vinyl group and a carboxyl group directly linked, and may be, for example, a radical polymerizable unsaturated fatty acid such as (meth) acrylic acid, (iso) crotonic acid, maleic acid, fumaric acid, and itaconic acid. Aromatic carboxylic acids; radically polymerizable aromatic carboxylic acids such as vinylbenzoic acid and 2-carboxy-4-isopropenyl-3-pyrrolidineacetic acid; and ester-forming derivatives (acid anhydrides or acid halides) thereof. .

Of these, (meth) acrylic acid, maleic acid, vinylbenzoic acid and ester-forming derivatives thereof are preferred, and (meth) acrylic acid and (meth) acrylic acid
Ester-forming derivatives of acrylic acid are particularly preferred.

The polymer (C1) may be a polymer of vinyl carboxylate (b) or a copolymer of (b) and another vinyl monomer (c). It is necessary to contain 50% by weight or more. Preferably,
The content is 70% by weight or more.

Other vinyl monomers (c) include:
(C-1) hydrophilic (excluding (b)), (c-2)
It may be of a lipophilic vinyl monomer.

As (c-1), nonionic compounds [hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acryloyloxy polyglycerol, vinyl alcohol, allyl Alcohol, (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N-vinyl-2-pyrrolidone, vinylimidazole, N-methylol-ε-caprolactam, N-
Methylol maleimide, N-vinyl succinimide, p
-Aminostyrene, N-vinylcarbazole, 2-vinylpyridine, 2-cyanoethyl (meth) acrylate, etc.]; anionic compound [(meth) acrylic acid, (anhydride) maleic acid, fumaric acid, itaconic acid, vinylsulfonic acid , (Meth) acrylic sulfonic acid, styrene sulfonic acid, vinyl benzoic acid, alkyl allyl sulfosuccinic acid,
Acids such as (meth) acryloyl polyoxyalkylene sulfate and salts thereof]; cationic compounds [N,
N-dimethylaminoethyl (meth) acrylate, N,
N-dimethylaminopropyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
N, N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, vinylaniline and acid salts thereof]; Compound having an amineimide group [1,1,1-trimethylamine (meth) acrylimide] , 1,1-dimethyl-1-ethylamine (meth) acrylimide, 1,1-dimethyl-
1- (2'-phenyl-2'-hydroxyethyl) amine (meth) acrylimide, 1,1,1-trimethylamine (meth) acrylimide, etc.].

Examples of (c-2) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, and glycidyl. (Meth) acrylate derivatives such as (meth) acrylate, N-alkyl (meth) acrylamide derivatives such as N, N-dibutyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, (meth) acrylonitrile, styrene,
Examples include 1-methylstyrene, vinyl acetate, butadiene, vinyl chloride, isoprene and the like.

The vinyl polymer (C1) can be obtained, for example, by the method described in JP-A-6-9848.

Examples of the polymer (C2) include a (co) polymer of an N-alkyl or N-alkylene (meth) acrylamide monomer and a copolymer of the monomer with the other vinyl monomer (c). .

Specific examples of the N-alkyl or N-alkylene (meth) acrylamide monomer constituting the polymer (C2) include N-ethyl (meth) acrylamide,
N, N-diethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-cyclopropyl (meth) acrylamide, N- ( (Meth) acryloylpiperidine, N- (meth) acryloylpyrrolidine, N- (meth) acryloylhexahydroazene, (meth) acryloylmorpholine, N-tetrahydrofurfuryl (meth) acrylamide, N-methoxypropyl (meth) acrylamide, N
-Ethoxypropyl (meth) acrylamide, N-isopropoxypropyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N- (2,2-dimethoxyethyl) -N-methyl (meth) acrylamide, N-1- Methyl-2-methoxyethyl (meth) acrylamide, N-1-methoxymethylpropyl (meth)
Acrylamide, N- (1,3-dioxolan-2-yl) -N-methyl (meth) acrylamide, N-8-acryloyl-1,4-dioxa-8-aza-spiro [4,5] decane, or N -Methoxyethyl-N-
n-Propyl (meth) acrylamide.

The polymer (C2) is described, for example, in JP-A-1-1-1.
It is obtained by the method described in JP-A-4276.

As the ω-alkoxypolyalkylene glycol mono (meth) acrylate or ω-phenoxypolyalkylene glycol mono (meth) acrylate constituting the polymer (C3), (meth) acrylic acid of ethylene oxide adduct of monohydric alcohol is used. Ester [ω-methoxy polyethylene glycol mono (meth) acrylate, ω-ethoxy polyethylene glycol mono (meth)
Acrylate, ω-propoxy polyethylene glycol mono (meth) acrylate, ω-butoxy polyethylene glycol mono (meth) acrylate, ω-cyclohexyl polyethylene glycol mono (meth) acrylate, ω-phenoxy polyethylene glycol mono (meth) acrylate, etc.], monovalent Ethylene oxide adduct of alcohol propylene oxide adduct [ω-methoxy (poly) oxypropylene polyoxyethylene mono (meth) acrylate etc.] Propylene oxide adduct of monohydric alcohol ethylene oxide adduct [ω-methoxypolyoxyethylene ( Poly) oxypropylene mono (meth) acrylate etc.] propylene oxide adduct of ethylene oxide adduct of propylene oxide adduct of monohydric alcohol [ω-methoxy (Poly) oxypropylene polyoxyethylene (poly) oxypropylene mono (meth) acrylate, etc.) or ethylene oxide adduct of propylene oxide adduct of monohydric alcohol ethylene oxide adduct [ω-methoxypolyoxyethylene (poly) oxypropylene Polyoxyethylene mono (meth) acrylate, etc.]. The polyoxyalkylene polymerization degree in the polyalkylene glycol mono (meth) acrylate is 2 to 50. Polymer (C3)
Examples thereof include (co) polymers of one or more of these mono (meth) acrylates and copolymers with comonomers. The same comonomer as the vinyl monomer (c) can be used.

The polymer (C3) is described, for example, in JP-A-6-2
It can be obtained by the method described in JP-A-3375.

The polyalkylene glycol monoalkyl monovinyl ether constituting the polymer (C4) includes:
Vinyl ether obtained from ethylene oxide adduct of monohydric alcohol and vinyl chloride (polyethylene glycol monoalkyl monovinyl ether, for example, polyethylene glycol monoethyl monovinyl ether, polyethylene glycol monopropyl monovinyl ether, polyethylene glycol monobutyl monovinyl ether, etc.), and monohydric alcohol Vinyl ether obtained from propylene oxide / ethylene oxide adducts of vinyl and vinyl chloride [(poly) oxypropylene polyoxyethylene glycol monomethyl monovinyl ether, etc.], (poly)
Oxyethylene (poly) oxypropylene polyoxyethylene glycol monomethyl monovinyl ether, etc.]. Examples of the polyalkylene glycol monophenyl monovinyl ether constituting the polymer (C5) include vinyl ethers obtained from ethylene oxide adducts of phenols and vinyl chloride (polyethylene glycol monophenyl monovinyl ether, such as polyethylene glycol monophenyl monovinyl ether). No. The degree of polymerization of the polyoxyalkylene in the polyalkylene glycol monovinyl ether is from 2 to 50.
It is.

As the polymer (C4) or (C5),
One or more of these monovinyl ethers include (co) polymers and copolymers with comonomers. As the comonomer, the same as the above-mentioned vinyl monomer (c) can be used.

The polymer (C4) or (C5) is described, for example, in Journal of Polymer Science: Part A: Polymer Chemistry, vol. 30, p. 2407 (1992).
Obtained by the method described in (1).

The weight average molecular weight of the vinyl polymer (C) is usually 1,000 to 5,000,000, preferably 1
000 to 2,000,000, particularly preferably 10
It is between 000 and 1,000,000.

In the present invention, the ratio between the resin latex (B) and the vinyl polymer (C) is usually 70% by weight.
９９99.99: 0.01 to 30, preferably 80 to 9
9.5: 0.05 to 20. (C) ratio is 0.0
If it is less than 1% by weight, the resulting gloss will be insufficient.

In the present invention, the composition comprising (B) and (C) is obtained by mixing the resin latex (B) and the aqueous solution of the vinyl polymer (C) alone or (C) with the hydrophilicity of the vinyl polymer (C). At a temperature lower than the temperature at which changes from
It is obtained by mixing with a normal mixing device (paddle-type stirring blade or the like).

In the present invention, the composition comprising (B) and (C) may be used, if necessary, for the purpose of increasing the adhesive strength to paper or increasing the water retention of the paper coating paint. Starch, oxidized starch, casein, soybean protein, synthetic protein, polyvinyl alcohol, maleic anhydride resin, carboxymethylcellulose, hydroxyethylcellulose, and other known water-soluble compounds used in paper and paper coatings. .

The method for producing the paper coating composition according to the present invention will be described. First, a pigment composition containing 10% by weight or more of a plastic pigment (A) is used as a pigment dispersant,
In the presence of an antifoaming agent, the mixture is dispersed in water using a dispersing device to obtain a pigment slurry. Next, a water-soluble binder dissolved in water is added, and after homogenization, a mixture of (B) and (C) and other additives are blended to obtain a paper coating paint.

Examples of the pigment dispersant include sodium poly (meth) acrylate, sodium pyrophosphate, sodium hexametaphosphate and the like. Examples of the antifoaming agent include a mineral oil-based antifoaming agent and a silicon-based antifoaming agent. Other additives include lubricants, pH adjusters, preservatives, water resistance agents, printability improvers, mold release agents, glossing agents, coloring agents, fluorescent dyes, antistatic agents, etc., and paper coating paints. Publicly known additives used for the above.

Examples of the dispersing device include a high speed mixer, a Keddy mill, a speed mill, a sigma blade kneader, a more house mill, a lead kneader and the like.

A method for producing a coated paper using the paper coating paint will be described. The coated paper is usually obtained by applying a paper coating paint to a base paper for coating using a coating machine, drying and treating. The coating amount of the paint is usually 1 to 50 g / m2, preferably 5 to 25 g as a weight after drying.
/ M2.

There is no particular limitation on the base paper for coating, and high-quality, medium-grade or lower-grade paper having a basis weight of 35 to 400 g / m 2 is used for acidic paper or neutral paper. If necessary, it is also possible to use a coated paper preliminarily coated with a general paper coating paint or the paper coating paint of the present invention as a base paper for coating. If necessary, the pre-coated paper may be subjected to a smoothing process in advance and used as a base paper.

The coating is performed by a coating machine in one or more layers. Coating machines include roll coaters (size presses, gate roll coaters, etc.), double-sided simultaneous coating type coaters (build blade coaters, twin blade coaters, etc.), various blade coaters (bench type coaters, helicopters, etc.), air knife coaters , A rod coater, a brush coater, a curtain coater, a chaplex coater, a bar coater, a gravure coater and the like.

The coated paper is obtained by drying and smoothing after coating. The drying and smoothing treatment may be performed by drying with a drier and then smoothing and finishing with a super calender, or by so-called cast finishing such as a wet cast method, a re-wet cast method, or a gel cast method. The method of the present invention can also improve low productivity due to poor drying property of a coating layer, which is one of the drawbacks of the conventional casting, in casting. In addition, even when the casting finish is performed at a high speed, the drum is not sufficiently dried and the coating layer is hardly stained such as the adhesion of the coating layer to the drum. Therefore, the method of the present invention is suitable for cast finishing.

As a dryer, an infrared dryer,
Drum dryers, air cap dryers, air wheel dryers, air conditioner bear dryers, and combinations thereof.

Although the drying temperature varies depending on the type of the dryer, the temperature inside the dryer is usually 50 to 1500.
° C.

The smoothing process is performed using a normal calendar (super calendar, gloss calendar, soft calendar,
A machine calendar or the like can be used on-machine or off-machine, and can also be performed using a cast drum. The treatment pressure and temperature are not particularly limited, and the nip pressure is usually 20 to 500 kg / cm, and the temperature is usually room temperature to 500 ° C. The number of pressure nips is usually 1
~ 15. In addition, a water application device using a roll, an electrostatic humidifier, a steam humidifier, or the like may be disposed together with the calendar for humidity control and humidification of the processed paper after finishing.

[0064]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Parts in the examples are parts by weight. Production Example 1 100 parts of 2-morpholinoethyl methacrylate (an ester of morpholine with one mole of ethylene oxide and methacrylic acid) and 0.1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) were added to an ampoule. After freezing and deaeration, the system was sealed and polymerized at 50 ° C. for 8 hours to obtain a polymer 1.

Production Example 2 90 parts of 2- (2-morpholinoethoxy) ethyl methacrylate (2 mol of ethylene oxide adduct of morpholine, ester with methacrylic acid), 10 parts of methyl methacrylate and 2,2′-azobis (2,2 0.1 part of 4-dimethylvaleronitrile) was added to the ampoule, frozen, degassed, sealed, and polymerized at 60 ° C. for 8 hours to obtain a polymer 2.

Preparation Example 3 80 parts of 2-morpholinopropyl methacrylate (ester of methacrylic acid with 1 mol of propylene oxide adduct of morpholine), 5 parts of styrene, 10 parts of methyl methacrylate, 5 parts of hydroxyethyl methacrylate and 2,2 ′ -Add 0.1 part of azobis (2,4-dimethylvaleronitrile) to the ampoule, freeze, deaerate and seal.
Polymerization was performed at 0 ° C. for 8 hours to obtain a polymer 3.

Production Example 4 80 parts of 2- (2-piperidinoethoxy) ethyl methacrylate, 10 parts of N, N-dibutylacrylamide, 10 parts of styrene and 2,2'-azobis (2,4-dimethylvaleronitrile) 0 0.5 part was added to an ampoule, frozen, degassed, sealed, and polymerized at 50 ° C. for 8 hours to obtain a polymer 4.

Production Example 5 In a pressurized reaction vessel equipped with a stirrer, a dropping cylinder, a nitrogen gas inlet tube, and a thermometer, 10 parts of acryloyloxypolypropylene (degree of polymerization = 12) sulfate as an emulsifier having a radical polymerizable group, water 102 Parts, 45 parts of styrene, 9 parts of methyl methacrylate, 4 parts of methacrylic acid, 1 part of sodium persulfate and 0.2 part of lauryl mercaptan, and the system was purged with nitrogen gas under stirring, and then 37 parts of butadiene was added from a dropping cylinder. Press in, 50 ° C for 30 hours, 85 ° C
For 5 hours. PH with aqueous sodium hydroxide solution
The mixture was adjusted to 8.5, and the unreacted monomer was stripped under reduced pressure to obtain SBR-based resin latex 1 (solid content: 47.9%, hereinafter referred to as SBR1). SBR1
The amount of the emulsifier in the aqueous phase was 0.0003 mmol / g (resin).

Production Example 6 In the same manner as in Production Example 6, 50 parts of styrene, 4 parts of methyl methacrylate, 4 parts of methacrylic acid, and 5 parts of acrylonitrile
Parts, butadiene 32 parts and methacryloyloxy polyoxypropylene (degree of polymerization = 9) sulfate Na salt 10
Part, SBR resin latex 2 (solids 48.3)
%, Hereinafter referred to as SBR2). The amount of emulsifier in the aqueous phase of SBR2 was 0.0005 mmol / g (resin).

Production Example 7 An SBR for comparison was prepared in the same manner as in Production Example 6, except that 10 parts of sodium alkyldiphenyletherdisulfonate [Eleminol MON-7 manufactured by Sanyo Chemical Industries, Ltd.] was used as an emulsifier.
Resin latex 3 (solid content 48.2%, hereinafter SBR3
). The amount of emulsifier in the aqueous phase of SBR3 is 0.1
mmol / g (resin).

Examples 1 to 5, Comparative Examples 1 and 2 25 parts of water, 0.3 part of dispersant [SN Dispersant 5040 manufactured by San Nopco Co., Ltd.], 0.1 part of sodium hydroxide
Part, antifoaming agent [San Nopco Co., Ltd. Nopco DF122]
0.1 parts together with 50 parts of a plastic pigment [NipolMH5055 manufactured by Zeon Corporation, total solid content = 30% by weight, glass transition temperature of plastic beads = 105 ° C.]
A pigment composition comprising 25 parts of primary clay and 10 parts of calcium carbonate is dispersed and mixed by a disper at 2,000 rpm for 30 minutes, and this dispersion is mixed with pregelatinized phosphorylated starch (30).
% Aqueous solution) 8.3 parts, ammonium stearate 0.1 part as a releasing agent, 0.07 part of a 40% aqueous solution of the polymer 1 obtained in Production Example 1, and 14 parts of SBR1 obtained in Production Example 6 14.1 parts of the obtained binder composition 1 and an appropriate amount of water were added and uniformly mixed to obtain a paper coating paint 1 having a concentration of 45% by weight. By performing the same operation as described above, polymer 2 and S
A paper coating composition 2 is prepared by using a binder composition 2 prepared by mixing BR1 with BR1, a paper coating composition 3 is prepared using a polymer 3 and SBR2, and a paper coating composition 3 is prepared using a polymer 4 and SBR2. Coating paints 4 were obtained. In addition, polymer 1 and SB
Paper coating 6 for comparison was obtained using R3.

As the pigment composition, a plastic pigment [NipolSX1302 manufactured by Zeon Corporation, total solid content = 50% by weight, glass transition temperature of resin = 100 ° C.] 25
The same procedure as in the preparation of the paper coating composition 1 was carried out except that a pigment composition consisting of 25 parts of a primary clay and 25 parts of a first grade clay and 12.5 parts of calcium carbonate was used to obtain a paper coating composition 5. . Further, the same operation as in the case of obtaining the paper coating paint 1 was carried out except that a plastic composition was not used and a pigment composition comprising 40 parts of primary clay and 10 parts of calcium carbonate was used. , Paper coating paint 7 for comparison
Was obtained respectively.

Each of the above paper coating paints 1 to 7 was applied to a high quality base paper having a basis weight of 100 g / m 2 by a roll coater so that the dry weight became 10 g / m 2, and immediately, a cast drum was formed by a press roll. (Surface temperature of 80 ° C.), pressed at a speed of 50 m / min, dried, peeled from the cast drum, and coated papers 1 to 5 of Examples 1 to 5 from paper coating paints 1 to 5,
Coated papers 6 and 7 of Comparative Examples 6 and 7 were prepared from the paper coating paints 6 and 7, respectively. The stain on the cast drum and various physical properties of the obtained coated paper were measured. Table 1 shows the results.

[0074]

[Table 1]

Gloss: 75 gloss was measured with a gloss meter manufactured by Tokyo Denshoku Co., Ltd. Whiteness: measured in accordance with JIS P-8123. Print gloss: Offset ink was solid-coated with RI-2 type manufactured by Akira Seisakusho Co., Ltd., dried at room temperature for 12 hours, and then measured at 75 ° gloss. Ink acceptability: Excess K in RI-2 type manufactured by Mei Seisakusho Co., Ltd.
Two minutes after solid printing of & N ink, the whiteness of the surface on which the ink was wiped off with a gauze was measured, and the decrease in whiteness was expressed as a percentage of the whiteness before printing. Drum stains: The cast drum after the coated paper was prepared was visually observed, and those with no stains were evaluated as good, and those with insufficient drying and the coating layer adhering to the drums were evaluated as x.
Indicated by

[0076]

The coated paper obtained according to the present invention is extremely excellent in white paper gloss, whiteness and printability.
In addition, the present invention can remarkably reduce the contamination of the drum, particularly in the case of cast finishing, because of its good drying property.

Claims (5)

(57) [Claims] 1. A pigment composition comprising at least 10% by weight of a plastic pigment (A) other than an ethylene polymer,
And the amount of emulsifier in the aqueous phase is 0.01 mmol / g (resin)
A coated paper coating comprising a binder comprising the following resin latex (B) and a vinyl polymer (C) whose hydrophilicity and hydrophobicity reversibly change at a certain temperature as a boundary. 2. The method according to claim 1, wherein (A) has a glass transition temperature of 50 to 15;
The paint according to claim 1, which is a 0 ° C plastic pigment. 3. The coating composition according to claim 1, wherein (B) is a resin latex produced using an emulsifier having a (meth) acryloyloxy group. 4. The coating according to claim 1, wherein (C) is at least one member selected from the group consisting of the following (C1) to (C5). (C1): a polymer comprising a vinyl carboxylic acid ester of an alkylene oxide adduct of a cyclic amine or an acyclic amine having 5 or more carbon atoms, (C2): a polymer comprising an N-alkyl or N-alkylene (meth) acrylamide, (C3): a polymer composed of polyalkylene glycol monoalkyl ether mono (meth) acrylate or polyalkylene glycol monophenyl ether mono (meth) acrylate, (C4): a polymer composed of polyalkylene glycol monoalkyl monovinyl ether, (C5) ): Polymer composed of polyalkylene glycol monophenyl monovinyl ether. 5. A high gloss coated paper obtained by applying the paint according to any one of claims 1 to 4 to paper.