Abstract A fluid dispersed suspension of clay or other negatively charged pigment or filler is produced by adding the pigment or filler to water in the presence of the combination of a nonionic surface active agent and a cationic surface active agent at an alkaline pH. The resulting suspension may be incorporated into cationic media, e.g., a solution of cationic starch, protein adhesive or cationic latex, to produce improved paper coating compositions. The suspension may be incorporated into a solution of a cationic resin to produce a conductive coating for electrographic reproduction paper. Improved optical performance and printability are obtained when the suspension is employed in the production of a filled paper product.
The modified pigment of claim 1 wherein the pigment is kaolin clay.
Claim 2
Dependent Claim
86 words
An aqueous suspension suitable for use in filling or coating paper comprising particles of a pigment which normally bears an anionic charge, and, as a dispersant, a mixture consisting essentially of a nonionic surface active agent, a cationic surface active agent and a strong base in amount such that said suspension has a pH of at least 8, said nonionic surface active agent and said cationic surface active agent being present in combined amounts not to exceed 0.5 percent of the weight of said pigment particles.
Claim 3
Dependent Claim
125 words
An aqueous suspension suitable for use in filling or coating paper and comprising particles of kaolin Clay, from 0.1 percent to 0.5 percent of the clay weight of a nonionic surface active agent which is a condensate of an alkylphenol with 7 to 16 moles ethylene oxide, the alkyl chain on the alkylphenol containing 4 to 9 carbon atoms, from 0.1 percent to 0.5 percent of the clay weight of a cationic surface active agent which is a quaternary ammonium salt, the weight ratio of nonionic surface active agent to cationic surface active agent being from 20:80 to 80:20, and sodium hydroxide in amount such that said suspension has a pH above 8.5, said suspension being free from condensed phosphate and alkali metal silicate dispersants.
Claim 4
Dependent Claim
89 words
A clay suspension consisting essentially of water, kaolin clay in amount sufficient to form a dispersion containing at least 45 percent clay solids and, as a dispersant, a mixture consisting essentially of a water-soluble nonionic surface active agent, a cationic surface active agent and alkali metal hydroxide in amount sufficient to provide a pH in the range of 8 to 13, said nonionic surface active agent and said cationic surface active agent being present in combined amounts not to exceed 0.5 percent of the weight of said pigment particles.
Claim 5
Dependent Claim
75 words
A modified kaolin clay pigment comprising particles of kaolin clay mixed with a dispersant consisting essentially of the combination of a nonionic surface active agent and a cationic surface active agent in combined amounts not to exceed 0.5 percent of the clay weight and in weight ratio in the range of 20:80 to 80:20, and sodium hydroxide in amount such that an aqueous suspension of the modified pigment has a pH of at least 8.
Claim 6
Dependent Claim
49 words
The modified clay pigment of claim 6 wherein the nonionic surface active agent is a condensate of an alkylphenol with 7 to 16 moles ethylene oxide, the alkyl chain on the alkylphenol containing 4 to 9 carbon atoms and the cationic surface active agent is a quaternary ammonium salt.