JP3177293B2 - Composition for coated paper and 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 coating for coated paper.
A composition for mat-coated paper, which has good coating suitability, has a small appearance of gloss after coating, and can produce coated paper having particularly excellent smoothness and strength and printing gloss, and
It relates to a mat-coated paper obtained by coating it.

[0002]

2. Description of the Related Art For example, matte coated paper having a glossiness of 30 or less according to JIS P-8142 and generally having a glossiness of 5 to 30 has been used mainly as a heavy carbon dioxide having a large particle size as a pigment. Using calcium or light calcium carbonate, clay, titanium oxide, aluminum hydroxide, satin white, barium sulfate, magnesium oxide, talc, inorganic pigments such as colloidal silica, and white pigments such as urea resin pigments A coating for coated paper using an organic pigment or the like is applied. The matte coated paper refers to a so-called matte coated paper having a glossiness of 5 to 30 as described above with respect to a coated paper having a glossiness of 50 to 85. I have. This matte coated paper is finished using a special calender roll or the like, but in order to make the glossiness 5-30, the glossiness will not be obtained at the temperature and pressure of the calender for finishing the normal coated paper. Finishing conditions in the calender are likely to be high, so temperature and pressure will be reduced. For this reason, the obtained coated paper tends to have non-uniform surface smoothness, and the ink absorption in printing tends to be non-uniform.

[0003]

Therefore, in recent years, a method of improving the particle size and shape of heavy and light calcium carbonates, particularly heavy and light calcium carbonates, for use as a coating material for coated paper, and Japanese Patent Application Laid-Open No.
No. 234993, JP-A-1-118695,
Although studies such as Japanese Patent Application Laid-Open No. 3-40897 have been advanced, the results of the studies by the present inventors show that they have good coating suitability and suppress the development of gloss after coating to 5 to 30. Coated paper is still insufficient to obtain uniform smoothness and good strength and print gloss. The present invention provides a coating composition with good coating suitability by using a novel adhesive in the production of coated paper, and the resulting coated paper has good printability, matte coating. A coating composition for paper is provided.

[0004]

Means for Solving the Problems As a result of repeated studies to improve these required physical properties, the present inventors have found that the paper coating composition of the present invention has unprecedented excellent coating suitability and printability. Which enables the production of mat-coated paper. That is, the present invention is as follows. (A) In a coating material for coated paper containing a pigment and an adhesive as main components, the following latex (A) and the following emulsion (B) are used as the adhesive in terms of solid content weight ratio (A) to (B). In a ratio of 90:10 to 50:50,
Comprising 10 to 25 parts by weight of solids based on parts by weight,
Composition for coated paper. (A) When the aliphatic conjugated diolefin-based monomer is 40 to 55
% By weight, 5 to 30% by weight of a vinyl cyanide monomer,
A latex obtained by emulsion polymerization of a component comprising 1 to 7% by weight of a monoolefin monomer and 8 to 54% by weight of another monoolefin monomer. (B) An emulsion containing a monoolefin-based monomer as a main component and emulsion-polymerized by emulsion polymerization and having an Tg of 70 ° C. or more and an average particle diameter of 30 to 100 nm. (B) Coated paper obtained by applying the composition according to (a).

Hereinafter, the present invention will be described in more detail. The latex (A) that can be used in the present invention includes, for example, SBR latex, MBR latex, SMBR
The latex is composed of the same components as the latex for paper coating used as an adhesive in the pigment coating composition for paper. Such a latex (A) comprises, in the polymer latex component, an aliphatic conjugated diolefin-based monomer in an amount of 40 to 55% by weight, preferably 45 to 55% by weight, a vinyl cyanide-based monomer in an amount of 5 to 30% by weight, Preferably, the content of the monoolefin monomer is 10 to 25% by weight,
% By weight, preferably 2 to 7% by weight, and other monoolefinic monomers 8 to 54% by weight, preferably 10 to 5% by weight.
A latex obtained by emulsion polymerization of a component consisting of 0% by weight is suitable. When the amount of the aliphatic conjugated diolefin-based monomer is less than 40% by weight, the surface dry strength of the coated paper obtained thereby becomes poor, and when it is 55% by weight or more, the surface wet strength of the coated paper obtained thereby becomes poor. Becomes When the content of the vinyl cyanide-based monomer is less than 5% by weight, the coated paper obtained thereby has poor print gloss, and when the content is not less than 30% by weight, the surface dry strength of the coated paper obtained thereby becomes poor. It becomes bad. Further, if the amount of the monoolefin-based monomer is less than 1% by weight, the surface strength of the coated paper obtained therefrom becomes poor, and if it is more than 7% by weight, the viscosity of the latex obtained thereby greatly increases. It will be difficult to provide for things. The particle size of the latex used in the present invention is suitably from 100 to 300 nm, and preferably from 120 to 200 nm.

As the aliphatic conjugated diolefin-based monomer used in the present invention, for example, one or a mixture of two or more selected from the group of butadiene, isoprene, 2-chlorobutadiene and the like can be used. Examples of the vinyl cyanide-based monomer used in the present invention include acrylonitrile, methacrylonitrile, and mixtures thereof. Examples of the monoolefin-based monomer used in the present invention include, for example, acrylic acid, crotonic acid, isocrotonic acid, vinyl acetic acid, methacrylic acid, tiglic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, maleic acid, anhydride Maleic acid, fumaric acid, citraconic acid, tetraconic acid, aliphatic unsaturated carboxylic acids such as itaconic acid, hydroxyethyl acrylate,
Esters of hydroxy-containing aliphatic unsaturated carboxylic acids such as hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N One or a mixture of two or more selected from the group of olefinic unsaturated amide monomers such as -methoxymethylacrylamide and N-methoxymethylmethacrylamide can be used. Examples of the other monoolefin-based monomer used in the present invention, for example, styrene,
Olefin-based aromatic monomers such as α-methylstyrene, chlorostyrene and dimethylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) Monoolefin monomers such as glycidyl acrylate and vinyl acetate can be used in combination of at least one kind or two or more kinds. These monomers are examples, and any other copolymerizable monomers can be used. Examples of the emulsifier used for emulsion polymerization include, for example, an alkyl sulfonate, an alkyl allyl sulfonate, an alkyl sulfate, an alkyl naphthalene sulfonate, an anionic activator such as an alkyl succinate sulfonate, a polyoxyethylene alkyl ether, a polyoxyethylene alkyl allyl ether, Nonionic activators, such as polyoxyethylene aliphatic esters, can be used alone or in combination. The use amount of these emulsifiers is usually 5% by weight or less based on all the constituent polymer components of the latex. As the polymerization initiator, an oxidizing agent such as potassium, sodium or ammonium persulfate, hydrogen peroxide, diisobutylbenzoyl peroxide, cumene hydroperoxide, lauryl peroxide or the like may be used alone,
These oxidizing agents can be used in combination with a reducing agent such as sodium sulfite, sodium bisulfite, sodium thiosulfate, or the like, that is, a redox system. Content ratio by weight of toluene-insoluble content of the obtained latex (hereinafter referred to as gel content)
Is strongly related to the film forming properties and adhesive strength of latex, and is an important physical property of latex. The gel content of latex used as an adhesive for pigment coated paper for offset rotary printing is 50% by weight or less, and the gel content of latex used as an adhesive for pigment coated paper printed by other methods is 25 to 95% by weight. The gel content of the latex used in the present invention is preferably from 60 to 90% by weight. The adjustment of the gel content of the latex is carried out during the emulsion polymerization by using butyl mercaptan, n-dodecyl mercaptan, t-
The reaction is performed using one or more chain transfer agents such as alkyl mercaptans such as dodecyl mercaptan and the like, and carbon tetrabromide and alcohols. The polymerization of the polymer latex used in the present invention is carried out at a temperature of 50 to 100 ° C. and a gauge pressure of 0 to 1.
The addition is performed in the range of 0 kg / cm ² , and the monomer and other additives used can be added all at once, dividedly or continuously.

Next, the emulsion (B) of the present invention has a Tg [glass transition temperature of film] of 70 ° C. or higher, which is obtained by emulsion polymerization using a monoolefin monomer as a main component and measured by vibron viscoelasticity. , Particle size analyzer [manufactured by Nikkaki Co., Ltd .; COULTER model N]
4SD SUB-MICRON PARTICLEAN
An emulsion having an average particle size (hereinafter, abbreviated as particle size) of 30 to 100 nm, as measured by ALYZER], is suitable. If the Tg of the emulsion is lower than 70 ° C., the resulting mat-coated paper has poor air permeability and low ink drying property during printing. The emulsion preferably has a particle size of 30 to 100 nm. When the particle size of the emulsion is less than 30 nm, the viscosity of the obtained emulsion polymer is significantly increased, so that it is difficult to provide the coating composition, and it is possible to use by reducing the resin solid content of the emulsion. This is because the solid content of the composition decreases and the surface strength of the coated paper obtained thereby also decreases. When the particle size of the emulsion is 100 nm or more, the latex (A) of the present invention has a weight ratio of (A) to (B) of 90:10.
Even when used at a ratio of 50:50, it is difficult to control the glossiness of the coated paper obtained from the coating composition to 5 to 30, and the printed gloss is less developed and the smoothness and strength are good. And the inability to obtain a mat-coated paper having printability.

The constituent polymer component of the emulsion (B) used in the present invention is preferably styrene or / and / or
In addition, other monomers, such as methyl methacrylate, having a monomer as a main component and copolymerizable therewith as necessary are used. As the copolymerizable monomer, for example, α-methylstyrene, olefinic aromatic monomers such as chlorostyrene and dimethylstyrene,
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2
-Ethylhexyl, glycidyl (meth) acrylate,
There are monoolefin monomers such as (meth) acrylonitrile and monomers such as vinyl acetate. Further, if necessary, for example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc., olefinically unsaturated carboxylic acid monomers, hydroxyethyl, hydroxyethyl methacrylate, hydroxypropyl acrylate And olefinic unsaturated hydroxy monomers such as hydroxypropyl methacrylate, olefins such as acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-methoxymethylacrylamide, and N-methoxymethylmethacrylamide. At least one or a combination of two or more dimer vinyl monomers such as unsaturated amide monomers and divinylbenzene can be used. These monomers are examples, and any other copolymerizable monomers can be used. As the emulsifier used in the emulsion polymerization, the same anionic surfactant and nonionic surfactant as in the case of the latex described above, or a reactive surfactant or the like can be used alone or in combination. An appropriate amount to be used is usually 5% by weight or less based on the constitution of the emulsion polymer.

Regarding the polymerization initiator, the same oxidizing agent as in the case of the latex described above can be used alone or in combination with a reducing agent, that is, it can be used in a redox system. The polymerization of the latex and the emulsion used in the present invention is carried out at a temperature in the range of 50 to 100 ° C., and the monomers and other additives used are added all at once,
It can be carried out by any of divided addition or continuous addition. Further, in order to stabilize the particles during the polymerization, for example, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol or the like may be added as a protective colloid agent. Next, the ratio of the latex (A) of the present invention to the emulsion (B) was 9% by weight.
0:10 to 50:50 is appropriate. Latex (A)
Is 90% by weight or more and the emulsion (B) is less than 10% by weight, the resulting coated paper has a glossiness of 5 to 30%.
In order to suppress the appearance of gloss,
This is because uniform and good smoothness cannot be obtained because the conditions for finishing by the calender are reduced. On the other hand, when the latex (A) is less than 50% by weight and the emulsion (B) is 50% by weight or more, the surface strength of the coated paper obtained thereby decreases. Further, the latex (A) and the emulsion (B) are suitably used in an amount of 10 to 25 parts by weight based on the solid content of the pigment. When the amount of the adhesive is less than 10 parts by weight with respect to the pigment, the surface strength of the mat-coated paper obtained with this coating composition is significantly reduced. This is because the matte coated paper has poor air permeability and markedly reduced ink drying property during printing.

[0010] The adhesive which can be used in the coating composition for mat-coated paper of the present invention includes, as necessary, a water-soluble polymer having an adhesive property, for example, casein, oxidized starch, phosphated starch, soy protein. A coating composition using carboxymethylcellulose, hydroxyethylcellulose, or the like may be applied. In addition, it is effective to add auxiliary agents such as a water retention agent, a dispersant, a water resistance agent, an antifoaming agent, a preservative, a coloring agent, and a release agent as necessary. The coating composition for mat-coated paper thus obtained is, for example, an air knife coater, a blade coater, a roll coater,
The coating composition is applied by a coating device such as a bar coater. At this time, the solid content concentration of the coating composition is usually 40 to 65% by weight.
It is. The base paper for mat-coated paper of the present invention includes high-quality paper, medium-quality paper, paperboard, and the like having a basis weight of 40 to 300 g / m ² , and a coating composition obtained by applying a coating composition to one or both surfaces in advance and drying them. Paper or the like is used. The coating amount of the coating composition on these base papers is usually 5 to 5 on one side by dry weight.
25 g / m ^{2 is} applied. After being coated and dried in this manner, a calender finish or the like is used. As the calender, a super calender, a gloss calender,
A mat calender or the like is used.

In the coating composition for mat coated paper of the present invention, that is, the coating composition for mat coated paper containing a pigment and an adhesive as main components, the use of the composition for coated paper of the present invention provides an unprecedented superiority. A mat-coated paper having smoothness, strength, and print gloss can be manufactured. Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Further, parts and% used below are based on weight unless otherwise specified.

[0012]

EXAMPLES First, examples of polymerization of latex and emulsion used in this example will be shown, and then examples of coating composition and application to mat-coated paper will be described. Production Example 1 (Production of latex A-1) In an autoclave equipped with a stirrer purged with nitrogen, 151 parts of deionized water, 0.25 part of sodium lauryl sulfate, 0.6 part of potassium persulfate, 0.4 part of normal dodecyl mercaptan And 45 parts of butadiene, 15 parts of acrylonitrile, 21 parts of styrene, 15 parts of methyl methacrylate, and 1 part of maleic acid as polymer monomers.
Parts, acrylic acid 2 parts and acrylamide 1 part, total 1
The polymerization was carried out at 70 ° C.
In 0 hours, an SBR latex having a polymerization rate of 98% was obtained. Then, P.P. After adjusting the H to 8 and performing steam stripping to remove unreacted monomers, deionized water was added to increase the solids concentration to 48.0.
% To give Latex A-1.

Production Examples 2-3 (Production of latex A-2, 3) The latex A-1
In the production example, butadiene, acrylonitrile, styrene and the like were changed as shown in Table 1, except that butadiene in the latex constituent polymer component was 40% by weight in the same operation as in Production Example 1. Acrylonitrile is 5
Latex A-2 was obtained in an amount of 55% by weight and acrylonitrile was contained in an amount of 30% by weight. Table 1 shows the types and amounts of the polymer monomers used in the production.

Comparative Production Examples 1 to 5 (Production of Latex A-4 to A-8) This production example is a matte-coated paper coating composition of the present invention and a latex for comparison. The type of the copolymerized modified monomer such as butadiene wt% or acrylonitrile in the component is a modified latex outside the scope of the present invention. That is, in the production example of latex A-1, Table-1
The butadiene in the latex-constituting polymer component was reduced to 3 by the same method and operation as in the production example of A-1, except that the polymerization was carried out using the kind and amount of the polymer monomer as shown in (1).
5 parts and 60% by weight of latex A-4, A-5
I got Then, in the production example of latex A-1,
Latex A-6 containing 45% by weight of butadiene in the monomer-constituting polymer component and not using acrylonitrile; and 0 containing no olefinically unsaturated carboxylic acid monomer and / or monoolefinic unsaturated monomer in the monomeric polymer component of the latex. Latex A- which is 0.5% by weight
7 and 9% by weight of latex A-8 were obtained, and the types and amounts of the polymer monomers used in their production are shown in Table 1.

Production Example 4 (Polymerization of Emulsion B-1) In a separable flask equipped with a stirrer, a thermometer and a reflux condenser, deionized water 8 was added.
8.5 parts and 0.4 parts of sodium lauryl sulfate were charged and kept at 80 ° C. while replacing with nitrogen under stirring, and 0.4 parts of potassium persulfate was added and completely dissolved. Parts, 1 part of Latemul S-180 (manufactured by Kao), 57 parts of styrene, 10 parts of acrylonitrile, 30 parts of methyl methacrylate, and 3 parts of methacrylic acid were added under stirring, and 5% of the prepared emulsion was separable. Charge in flask 3
Polymerization was carried out for 0 minutes, and the remaining emulsion was added over about 2 hours to carry out polymerization. After the total amount was added, aging was performed for another 2 hours. Next, the pH was adjusted to 8 with a 5% aqueous solution of sodium hydroxide, and the solid content concentration was 40.0% and the Tg was 107.
Emulsion B-1 having a particle size of 67 nm and a temperature of ° C. was obtained, and its physical properties are shown in Table 2.

Production Examples 4 to 6 (Polymerization of Emulsions B-2 and 3) In other words, in the polymerization examples of Emulsion B-1, the amounts of styrene, methyl methacrylate, acrylonitrile, etc. used as constituent polymer components are shown in Table 1. The emulsion B-2 having a Tg of 71 ° C. and a particle diameter of 33 nm and an emulsion B-3 having a Tg of 96 ° C. and a particle diameter of 98 nm were prepared in the same manner as in Polymerization Example B-1. The physical properties are shown in Table 2.

Comparative Production Examples 6 to 8 (Emulsion B-4 to B-6 Polymerization)
Alternatively, the emulsion has a particle diameter outside the scope of the claims of the present application. That is, in the polymerization example of the emulsion B-1,
Emulsion B- having a Tg of 108 ° C. and a particle size of 23 nm was obtained in the same manner as in Polymerization Example B-1 by changing the amounts of styrene, methyl methacrylate and the like used as constituent polymer components as shown in Table-2. 4 and Tg are 90 ° C and the particle size is 112 nm.
Emulsion B-6 having a Tg of 60 ° C. and a particle diameter of 64 nm was obtained.
It was shown to.

[0018]

[Table 1]

[0019]

[Table 2]

Examples of the present invention using the latex and emulsion obtained as described above in a coating composition are shown below. Example 1 (Preparation of coating composition) 60 parts of calcium carbonate (trade name: Tsunex E, manufactured by Shiraishi Kogyo Co., Ltd.), 40 parts of kaolin (trade name: UW90, manufactured by Engelhardt, USA), Alon T-40 (Toa Gosei) as a dispersant ) And dispersed in water using a Cowles disperser to prepare a 70% pigment slurry. Then, 3 parts of starch (manufactured by Japan Food Processing Co., Ltd .: MS3600) and a latex A-1 dissolved by heating.
Was added, and 4 parts of Emulsion B-1 were added. Finally, water was added to adjust the solid content to 60%, and the coating composition for mat coating of the present invention (hereinafter referred to as the coating composition of Example 1).
I got The viscosity of the obtained coating composition is BM at 25 ° C.
Type viscometer (manufactured by Tokyo Keiki) 60 rpm and HI-SH
EAR VISCOMETER (manufactured by Kumagai Riki Kogyo) 88
Measured at 00 rpm, the physical properties of the coating composition are shown in Table-3. (Production of coated paper) The above-mentioned coating composition was prepared by adding 104.7 basis weight.
g / m ² of base paper with an applicator blade so that the coating amount of each coating composition becomes 15 g / m ² in terms of dry weight, followed by drying. After leaving in a wet room for 24 hours, the temperature is 60 ° C and the linear pressure is 60k.
g / cm 2 times through a super calender to obtain a coated paper. The physical properties of the coated paper were measured, and the results are shown in Table 3. The smoothness and air permeability were measured with an Oken type air permeability smoothness tester (made by Asahi Seiko). The glossiness was measured according to JIS P-8142. The glossiness after printing can be measured using RI printing tester (Meiji Seisakusho)
And printing was performed according to JIS P-8142. The surface strength was printed by an RI printing tester (manufactured by Meisho Seisakusho), and the surface picking was evaluated on a 10-point scale by observing picking on the surface (10: good without surface picking → 1: poor picking occurred on the entire surface). The ink drying property was measured by printing with a RI printing tester (manufactured by Meisho Seisakusho), and the density of the transferred ink was measured with a Macbeth ink densitometer (Sakata Inx). The surface uniformity was judged by visually observing the surface condition of the coated paper (◎ →
Yu, 〇 → good, △ → possible, X → impossible). Examples 2 to 7 Similarly to the latex A-1 and the emulsion B-1 used in Example 1, the addition amounts of the latexes A-2 and A-3 and the emulsions B-2 and B-3 are shown in Tables 1 and 2, respectively.
3 and the amount of water added last was adjusted to a coating solids concentration of 60%, and the same operation as in Example 1 was carried out to obtain six kinds of mat-coated paper coating compositions of the present invention ( Examples 2 to 7 are hereinafter referred to as coating compositions), and the physical properties of the obtained coating compositions are shown in Table 3. A coated paper was manufactured using the above coating composition in the same manner as in Example 1, and the coated paper physical properties of the obtained coated paper were measured. The results are shown in Table-3. Examples 8 and 9 Like the latex A-1 and the emulsion B-1 used in Example 1, the addition amounts of the latex A-2 and the emulsion B-2 were 9 parts and 1 part, respectively, as shown in Table-3. The coating composition for mat-coated paper of the present invention (hereinafter referred to as Example 8) And the physical properties of the obtained coating composition are shown in Table-3. In the same manner as in Example 1, the latex A-3 and the emulsion B-3 were used in an amount of 12 parts as shown in Table 3. A composition (hereinafter, referred to as a coating composition in Example 9) was obtained, and the physical properties of the obtained coating composition are shown in Table 3. A coated paper was manufactured using the above coating composition in the same manner as in Example 1, and the coated paper physical properties of the obtained coated paper were measured. The results are shown in Table-3.

Comparative Examples 1 and 2 In this comparative example, first, in order to further clarify the effect of using the latex (A) and the emulsion (B) of the present invention,
An example of a coating composition using latex (A) or emulsion (B) alone is shown. 60 parts of calcium carbonate (manufactured by Shiraishi Kogyo: trade name Tunex E), 40 parts of kaolin (manufactured by U.S.A. Engelhardt: trade name UW90), and 0.3 part of Aron T-40 (Toa Gosei) as a dispersant were added, followed by dispersion in Cowles. It was dispersed in water by using a machine to prepare a pigment slurry having a concentration of 70%. Then, 3 parts of starch (manufactured by Japan Food Processing Co., Ltd .: MS3600) and 17 parts of latex A-1 were added thereto, and water was added thereto.
%, A coating composition (hereinafter referred to as Comparative Example 1 coating composition) was obtained, and the physical properties of the obtained coating composition are shown in Table-3. In the same manner, 17 parts of Emulsion B-1 was added, and finally, water was added to adjust the solid content to 60% to obtain a coating composition (hereinafter referred to as Comparative Example 2 coating composition). Table 3 shows the physical properties of the coating composition. A coated paper was manufactured using the above coating composition in the same manner as in Example 1, and the coated paper physical properties of the obtained coated paper were measured. The results are shown in Table-3. Comparative Examples 3 to 7 Next, using latexes A-4 to A-8 and the like which are outside the limited range of the present invention, the amount of water added last was adjusted using the added amounts as shown in Table 3, and the solid content was adjusted. Except that the partial concentration was changed to 60%, the same operation as in Example 1 was carried out to obtain five types of comparative symmetric coating compositions of the present invention (hereinafter referred to as Comparative Examples 3 to 7). Table 3 shows the physical properties. Using the above coating composition, a coated paper was produced in the same manner as in Example 1,
The physical properties of the coated paper thus obtained were measured, and the results are shown in Table 3. Comparative Examples 8 to 10 Further, emulsions B-4 to B- outside the limited range of the present invention.
The present invention is carried out in the same manner as in Example 1, except that the solid content concentration is adjusted to 60% by using 6 and the like and adjusting the amount of water added last using each addition amount as shown in Table-3. The following five coating compositions for comparison (hereinafter referred to as Comparative Examples 8 to 10) were obtained, and the physical properties of the obtained coating compositions are shown in Table 3. A coated paper was manufactured using the above coating composition in the same manner as in Example 1, and the coated paper physical properties of the obtained coated paper were measured. The results are shown in Table-3.

[0022]

[Table 3]

[0023]

From the numerical values in Table 3, the paper coating composition obtained from the coating compositions of the examples falling within the limited range of the present invention has a low viscosity and a good viscosity under high shear. Shows that matte coated paper with smoothness, print gloss and surface strength, unprecedented excellent coatability and printability can be produced, and the paper coating composition of the present invention is an unprecedented useful paint Obviously, it is a composition.

Continuation of the front page (56) References JP-A-1-223170 (JP, A) JP-A-63-275791 (JP, A) JP-A-60-45696 (JP, A) JP-A-54-64116 (JP , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D21H 19/58

Claims (2)

(57) [Claims] 1. A coating material for a coated paper containing a pigment and an adhesive as main components, wherein the following latex (A) and the following emulsion (B) are used as the adhesive in terms of solid content weight ratio (A) to (A). A composition for coated paper, wherein B) is used in a ratio of 90:10 to 50:50 and a solid content of 10 to 25 parts by weight based on 100 parts by weight of the pigment. (A) When the aliphatic conjugated diolefin-based monomer is 40 to 55
% By weight, 5 to 30% by weight of a vinyl cyanide monomer,
A latex obtained by emulsion polymerization of a component comprising 1 to 7% by weight of a monoolefin monomer and 8 to 54% by weight of another monoolefin monomer. (B) An emulsion containing a monoolefin-based monomer as a main component and emulsion-polymerized by emulsion polymerization and having an Tg of 70 ° C. or more and an average particle diameter of 30 to 100 nm. 2. Coated paper obtained by applying the composition according to claim 1.