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Invert size for the internal and surface sizing of paper

  • US 4,983,257 A
  • Filed: 01/09/1989
  • Issued: 01/08/1991
  • Est. Priority Date: 09/05/1986
  • Status: Expired due to Fees
First Claim
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1. In an invert size for the engine and tub sizing of paper, comprising an aqueous dispersion of a fortified, hydrogenated or disproportionated and optionally esterified rosin or mixture of such rosins and of a dispersant that contains digested casein or an emulsifier of the formula


  • space="preserve" listing-type="equation">[R--(OCH.sub.2 CH.sub.2).sub.n --O--A].sup.-.sub.x M.sup.x+(I)
wherein R is an alkylphenyl, alkyl, or alkenyl group or a cycloalkyl group with condensed rings, A is a group of the formula --CH2 COO or --SO3, Mx+ is a cation, x is 1 or 2, and n is a number such that approximately 21 to 76% of the molecular weight of the anion is in the --OCH2 CH2 groups, the improvement which comprises including cationic starch in the dispersion as a dispersant, the dispersion by weight comprising about 5 to 50% of the rosin or mixture of rosins and 1 to 15% of the dispersant based on the rosin or mixture of rosins, with the remainder consisting essentially of water, the ratio of the weight of casein or emulsifier of Formula I to the weight of cationic starch in the dispersant ranging from about 20;

80 to 80;

20, the ratio of the weight of rosin;

cationic starch ranging from about 1;

0.0280 to 1;

0.0710.

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