JP2004076216A5 - - Google Patents

Claims (14)

  A paper coating composition comprising hollow polymer particles (a) having a volume porosity of 60 to 99% and an average particle diameter of 300 to 5000 nm.   The paper coating composition according to claim 1, wherein the hollow polymer particles (A) have a shell thickness of 30 to 200 nm. In terms of solid content, the hollow polymer particles (A) 0.5 to 99.5 wt%, the binder (b) a 0.5 to 99.5 wt% and the pigment (c) 及 Beauty / or thickener ( D) 0 to 99% by mass [However, the sum of (A), (B), (C) and (D) is 100% by mass. The composition for paper coating of Claim 1 or 2 to contain. The hollow polymer particles (a) are composed of 5 to 80% by mass of an unsaturated carboxylic acid (a-1) and other radical polymerizable monomer (a-2) copolymerizable with the unsaturated carboxylic acid (a-1). 20 to 95% by mass [However, the total of (a-1) and (a-2) is 100% by mass. A polymer particle (A) by emulsion polymerization of a monomer (a) consisting of
Thereafter, in the presence of 5 to 1000 parts by mass of the polymer particles (A), 0 to 20% by mass of the unsaturated carboxylic acid (b-1) and other copolymerizable with the unsaturated carboxylic acid (b-1) Radical polymerizable monomer (b-2) 80 to 100% by mass [However, the total of (b-1) and (b-2) is 100% by mass. A part of 100 parts by mass of the monomer (b) consisting of a polymer component is emulsion-polymerized, and the surface layer of the polymer particles (A) has a polymer component obtained by polymerizing a part of the monomer (b) and Preparing core-shell polymer particles (B) coated with a shell layer containing a reactive monomer component;
Then, the pH of the dispersion containing the polymer particles (B) is adjusted to 7 or more with a volatile base to neutralize and swell the polymer particles (B), and then polymerize the unreacted monomer components. The paper coating composition according to any one of claims 1 to 3.   The paper coating composition according to claim 4, wherein the shell layer has a mass ratio of the polymer component to the unreacted monomer component of 99: 1 to 50:50.   6. The paper coating composition according to claim 5, wherein the shell layer is emulsion-polymerized by first charging all or part of the monomer (b) to be the polymer component of the monomer (b). .   When the monomer (b) charged at once is 100% by mass, 50% by mass or more of the monomer (b) charged at once is an unsaturated carboxylic acid ester and / or an ethylenic aromatic compound. The composition for paper coating of 6.   The composition for paper coating according to claim 6 or 7, wherein a mass ratio of the monomer (b) to be charged all at once and the polymer particles (A) is 10: 1 to 1:10.   The radical polymerizable monomer (b-2) contains a crosslinkable radical polymerizable monomer, and the content of the crosslinkable radical polymerizable monomer is such that the total mass of the radical polymerizable monomer (b-2) is 100% by mass. The composition for paper coating according to any one of claims 4 to 8, wherein the composition is 50% by mass or less.   The paper coating material according to any one of claims 4 to 8, wherein a temperature of the dispersion when the polymer particles (B) are neutralized and swollen is equal to or lower than a glass transition temperature (Tg) of the polymer component. Composition. When the monomer (b) is subjected to emulsion polymerization, the polymerization is performed using only the radical polymerizable monomer (b-2), and 10 to 35 % by mass of the total amount of the monomer (b) is polymerized. The paper coating composition according to any one of claims 4 to 9, wherein the carboxylic acid (b-1) is shared and polymerized.   A paper and a coating formed on one or both sides of the paper and containing hollow polymer particles (A) and a binder, the hollow polymer particles (A) have a volume porosity of 60 to 99%, The coated paper is characterized in that the average particle size is 300 to 5000 nm. Applying the paper coating composition according to any one of claims 1 to 11 to a paper so that a coating amount after drying is 0.3 to 30 g / m ^2. A method for producing coated paper, which is characterized.   The method for producing a coated paper according to claim 13, wherein the coating is performed by a non-contact coating method.