Paper coated with binder and organic pigment particles

Claim 2

A coated paper comprising a paper substrate having adhered to at least one surface thereof a coating composition comprised of a binder material and an organic pigment, said organic pigment being water-insoluble graft copolymer particles consisting essentially of the free radical catalyzed graft copolymerization product of (1) at least one ethylenically unsaturated monomer and (2) a water-soluble 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 alpha-chloroacrylate, methyl methacrylate, isopropyl methacrylate, phenyl methacrylate, vinyl chloride, acrylonitrile, methacrylonitrile, and monomers having the formula ##STR2## wherein R is hydrogen or methyl, Y is methyl or chlorine, and n is 0, 1, 2, or 3, and said prepolymer (2) being selected from the group consisting of anionic prepolymers and nonionic prepolymers prepared by the addition polymerization of a vinyl monomer or mixtures of vinyl monomers, 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, said graft copolymer having a Tg equal to or greater than 75° C.

Claim 3

The coated paper of claim 1 wherein said prepolymer (2) has an RSV of from about 0.1 to about 1 (1 M NaCl, 1%, 25° C.) and is selected from the group consisting of poly(acrylamide), poly(methacrylamide), copolymers of, by weight, (a) from about 98% to about 50% of an amide selected from the group consisting of acrylamide and methacrylamide and (b) from about 2% to about 50% of an acid selected from the group consisting of acrylic acid and methacrylic acid.

Claim 4

The coated paper of claim 2 wherein monomer (1) is styrene.

Claim 5

The coated paper of claim 3 wherein there is employed in combination with the styrene a polyethylenically unsaturated monomer in an amount at least sufficient to provide cross-linked graft copolymer particles.

Claim 6

The coated paper of claim 4 wherein the polyethylenically unsaturated monomer is divinylbenzene.

Claim 7

The coated paper of claim 3 wherein the prepolymer (2) is poly(acrylamide).

Claim 8

The coated paper of claim 3 wherein the prepolymer (2) is a copolymer of from about 98% to about 50% acrylamide and from about 2% to about 50% acrylic acid.

Claim 9

The coated paper of claim 2 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 10

The coated paper of claim 3 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 11

The coated paper of claim 4 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 12

The coated paper of claim 5 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 13

The coated paper of claim 6 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 14

The coated paper of claim 7 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 15

A paper product comprised of cellulosic fibers and an organic pigment, the organic pigment being essentially uniformly dispersed throughout the paper product by way of internal addition to an aqueous dispersion of the cellulosic fibers prior to product formation, said organic pigment being water-insoluble graft copolymer particles consisting essentially of the free radical catalyzed graft copolymerization product of (1) at least one ethylenically unsaturated monomer and (2) a water-soluble 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 alpha-chloroacrylate, methyl methacrylate, isopropyl methacrylate, phenyl methacrylate, vinyl chloride, acrylonitrile, methacrylonitrile, and monomers having the formula ##STR3## wherein R is hydrogen or methyl, Y is methyl or chlorine, and n is 0, 1, 2, or 3, and said prepolymer (2) being selected from the group consisting of anionic prepolymers and nonionic prepolymers prepared by the addition polymerization of a vinyl monomer or mixtures of vinyl monomers, 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, said graft copolymer having a Tg equal to or greater than 75° C.

Claim 16

A paper product comprised of cellulosic fibers and an organic pigment, the organic pigment being essentially uniformly dispersed throughout the paper product by way of internal addition to an aqueous dispersion of the cellulosic fibers prior to product formation, said organic pigment being water-insoluble graft copolymer particles consisting essentially of the free radical catalyzed graft copolymerization product of (1) at least one ethylenically unsaturated monomer and (2) a water-soluble 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 alpha-chloroacrylate, methyl methacrylate, isopropyl methacrylate, phenyl methacrylate, vinyl chloride, acrylonitrile, methacrylonitrile, and monomers having the formula ##STR3## wherein R is hydrogen or methyl, Y is methyl or chlorine, and n is 0, 1, 2, or 3, and said prepolymer (2) being selected from the group consisting of anionic prepolymers and nonionic prepolymers prepared by the addition polymerization of a vinyl monomer or mixtures of vinyl monomers, 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, said graft copolymer having a Tg equal to or greater than 75° C.

Claim 17

The paper product of claim 14 wherein said prepolymer (2) has an RSV of from about 0.1 to about 1 (1 M NaCl, 1%, 25° C.) and is selected from the group consisting of poly(acrylamide), poly(methacrylamide), copolymers of, by weight, (a) from about 98% to about 50% of an amide selected from the group consisting of acrylamide and methacrylamide and (b) from about 2% to about 50% of an acid selected from the group consisting of acrylic acid and methacrylic acid.

Claim 18

The paper product of claim 15 wherein monomer (1) is styrene.

Claim 19

The paper product of claim 16 wherein there is employed in combination with the styrene a polyethylenically unsaturated monomer in an amount at least sufficient to provide cross-linked graft copolymer particles.

Claim 20

The paper product of claim 17 wherein the polyethylenically unsaturated monomer is divinylbenzene.

Claim 21

The paper product of claim 16 wherein the prepolymer (2) is poly(acrylamide).

Claim 22

The paper product of claim 16 wherein the prepolymer (2) is a copolymer of from about 98% to about 50% acrylamide and from about 2% to about 50% acrylic acid.

Claim 23

The paper product of claim 15 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 24

The paper product of claim 16 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 25

The paper product of claim 17 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 26

The paper product of claim 18 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 27

The paper product of claim 19 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.

Claim 28

The paper product of claim 20 wherein the prepolymer moiety of the particles has chemically bonded thereto an aldehyde.