초록 ▼

Disclosed are novel organic pigments adapted particularly for use as fillers for paper. The organic pigments are finely divided particles obtained by graft copolymerizing an ethylenically unsaturated monomer, such as styrene, onto a water-soluble cationic prepolymer in an aqueous solution and in the

Disclosed are novel organic pigments adapted particularly for use as fillers for paper. The organic pigments are finely divided particles obtained by graft copolymerizing an ethylenically unsaturated monomer, such as styrene, onto a water-soluble cationic prepolymer in an aqueous solution and in the presence of a free-radical polymerization initiator.

대표청구항 ▼

In the method of manufacturing paper wherein an opacifying agent is used to provide opacity in the final paper product, either by means of a coating or by means of internal addition to the paper pulp, the improvement wherein there is employed as at least a portion of the opacifying agent water-insol

In the method of manufacturing paper wherein an opacifying agent is used to provide opacity in the final paper product, either by means of a coating or by means of internal addition to the paper pulp, the improvement wherein there is employed as at least a portion of the opacifying agent water-insoluble graft copolymer particles consisting essentially of the free radical catalyzed graft copolymerization product of (1) at least one ethylenically unsaturated monomer and 82) a water-soluble cationic prepolymer having an RSV of about 0.1 to about 2.5 (1 M NaCl, 1%, 25°C.), the prepolymer moiety of the graft copolymer particles being present on the surface of the particles, said monomer (1) being selected from the group consisting of methyl alpha-chloroacrylate, ethyl alphachloroacrylate, methyl methacrylate, isopropyl methacrylate, phenyl methacrylate, vinyl chloride, acrylonitrile, methacrylonitrile, and monomers having the formula [Figure] wherein R is hydrogen or methyl, Y is methyl or chlorine, and n is 0, 1, 2, or 3, and said prepolymer (2) being the addition polymerization product of (i) about 5 mole percent to 100 mole percent of at least one cationic monomer selected from the group consisting of [Figure] (I) wherein R1 is hydrogen or methyl, R2 is hydrogen or a C1-C4 alkyl, R3 is hydrogen, a C1-C4 alkyl, [Figure] where Y is hydroxyl or halogen, [Figure] where n is an integer 1 or more and X-is an anion, [Figure] (II) wherein R1 is hydrogen or a C1-C4 alkyl, R2 is hydrogen, alkyl or substituted alkyl, and R3 and X-are as defined in formula (I), [Figure] (III) wherein R1, R2, R3 and X-are as defined in formula (I), [Figure] (IV) wherein R1, R3 and X-are as defined in formula (I), [Figure] (V) wherein R1, R2, R3 and X-are as defined in formula (I), and n is an integer 1, 2 or 3 and [Figure] (VI) wherein R1, R2, R3 and X-are as defined in formula (I), and (ii) from about 95 mole percent to 0 mole percent of at least one ethylenically unsaturated nonionic monomer selected from the group consisting of N-vinyl pyrrolidone, ethylenically unsaturated monomers having amide functionality, and ethylenically unsaturated monomers having hydroxyl functionality, the amount of prepolymer (2) employed in preparing the graft copolymer particles being from about 1 part to about 25 parts by weight for each 100 parts by weight of monomer (1) employed.