Abstract: A coating composition for paper comprising a mineral pigment and a polymer latex prepared by emulsion polymerization of a monomeric mixture comprising an aliphatic conjugated diene monomer, an ethylenically unsaturated carboxylic acid monomer and a monoolefinic monomer in a weight proportion of 24.5-50:0.5-5:45-75 in the presence of a chain transfer agent, characterized in that the chain transfer agent is carbon tetrachloride and an alkylmercaptan in combination.

Abstract: In the emulsion polymerization of an .alpha.-alkylstyrene and an unsaturated nitrile copolymerizable therewith in a weight proportion of 70:30 to 80:20 in the presence of a radical initiator, an improved process wherein the monomers are introduced into the reaction system in such a manner that the concentration of the unreacted unsaturated nitrile in the reaction system is not less than 31% by weight to the entire amount of the unreacted monomers in the reaction system at the completion of the introduction of the monomers, whereby a copolymer of the .alpha.-alkylstyrene and the unsaturated nitrile having an excellent thermal resistance is produced with marked decrease in the amount of unreacted monomers.

Abstract: A process for preparing a thermoplastic resin having high heat resistance by emulsion polymerization of an .alpha.-alkylstyrene compound of the formula: ##STR1## wherein R.sub.1 is C.sub.1 -C.sub.3 alkyl and R.sub.2 is hydrogen, C.sub.1 -C.sub.3 alkyl or halo(C.sub.1 -C.sub.3)alkyl and an unsaturated nitrile in a weight proportion of 65:35 to 80:20 in the presence of a radical initiator, characterized in that the whole amount of the .alpha.-alkylstyrene compound and 10 to 99% by weight of the unsaturated nitrile on the basis of its total amount are first subjected to polymerization and, after the polymerization, the remaining portion of the unsaturated nitrile is added to the reaction mixture and the resultant mixture is subjected to further polymerization until the polymerization is substantially completed.

Abstract: A process for preparing a thermoplastic resin having excellent heat resistance, impact resistance and processability, which comprises emulsion polymerization of a mixture comprising a monomeric mixture consisting essentially of an .alpha.-alkylstyrene, methyl methacrylate and an unsaturated nitrile and a diene rubber latex containing particles of 400 to 900 A in particle size in an amount of not less than 30% by weight in the presence of a radical initiator, the weight proportion of the monomeric mixture and the diene rubber latex (solids) being from 60:40 to 95:5.

Abstract: A color developer sheet sensitized in a color developing property on contact with a chromogenic material and improved in the light-resistance of the developed color, which comprises a support sheet and a coating composition comprising an organic color developer and, as a binder, a latex of a copolymer prepared by polymerization of a mixture essentially consisting of about 20 to 70% by weight of one or more aliphatic conjugated diolefin monomers, about 0.5 to 15% by weight of one or more unsaturated carboxylic acid monomers and about 15 to 79.5% by weight of one or more other olefin monomers copolymerizable with them and having a gel content of about 95 to 100% by weight applied onto a surface of the said support sheet to make a color developer layer.

Abstract: A color developer sheet sensitized in a color developing property on contact with a chromogenic material and improved in the light-resistance of the developed color, which comprises a support sheet and a coating composition comprising an organic color developer and, as a binder, a latex of a copolymer prepared by polymerization of a mixture essentially consisting of about 20 to 70% by weight of one or more aliphatic conjugated diolefin monomers, about 0.5 to 15% by weight of one or more unsaturated carboxylic acid monomers and about 15 to 79.5% by weight of one or more other olefin monomers copolymerizable with them and having a gel content of about 95 to 100% by weight applied onto a surface of the said support sheet to make a color developer layer.

Abstract: A copolymer latex comprising 25 to 45 percent by weight of a conjugated diolefinic monomer, 3 to 40 percent by weight of an alkyl ester of unsaturated carboxylic acid, 1 to 5 percent by weight of a hydroxyalkyl-containing unsaturated monomer, 0.5 to 4 percent by weight of an unsaturated carboxylic acid monomer and the remaining percent of an alkenyl aromatic monomer, and a pigmented paper coating composition, which can give a coated paper having excellent properties, such as water resistance, "transferability of multicolor offset printing ink" and blister resistance in case of web offset printing.