| 摘要 |
<p>A paper coating composition in the form of an aqueous dispersion comprising an intimate mixture of mineral pigment, starch and a copolymer containing from 30 to 55% by weight of butadiene-1,3, residues, from 0.1 to 13% of at least one ethylenically unsaturated mono- or dicarboxylic acid residues, and at least half of the remainder being either styrene or methyl methacrylate or a mixture of both styrene and methyl methacrylate residues, any other constituent of the copolymer being derived from another monoethylenically unsaturated compound, said copolymer being in the form of an aqueous dispersion, there being in the composition from 8 to 50 parts dry weight of starch and butadiene-1,3 copolymer together per 100 parts dry weight of pigment and from 0.5 to 2 parts dry weight of butadiene-1,3 copolymer to each one part dry weight of starch. The ethylenically unsaturated acid may be acrylic, methacrylic, maleic, itaconic and cinnamic acid. Mineral pigments include china clay, titanium dioxide, satin white blanc fixe and calcium carbonate.ALSO:Paper is coated with an aqueous dispersion comprising an intimate mixture of mineral pigment, starch and a copolymer containing from 30-55% by weight of butadiene-1,3 residues, from 0,1-13% of at least one ethylenically unsaturated mono- or dicarboxylic acid residues, and at least half the remainder being either styrene or methyl methacrylate or a mixture of both styrene and methyl methacrylate residues, any other constituent of the copolymer being derived from another monoethylenically unsaturated compound, said copolymer being in the form of an aqueous dispersion, there being in the composition from 8-50 parts dry weight of starch and butadiene1,3 copolymer together per 100 parts dry weight of pigment and from 0,5-2 parts dry weight of butadiene-1,3 copolymer to each one part dry weight of starch. Mineral pigments include china clay, titanium dioxide, satin white, blanc fixe and calcium carbonate. In an example the composition was used to coat a bleached sulphite wood free base paper of Cobb size 40 by means of the air knife coating process to give a coat weight of 25 grms./sq. metre on each side.</p> |
