Patent ID: 6630530
Filing Date: 2003-10-07
Classification: C08K

Abstract:
A hydrophilic polymer dispersion containing a colloidal silica prepared by following steps of:i) mixing 1.0Ëœ25 wt % of acrylamide, 0Ëœ2 wt % of anionic monomer selected from the group consisting of acrylic acid, methacrylic acid and itaconic acid, 1.0Ëœ30 wt % of cationic monomer mixture of compound of formula I and formula II, 0.5Ëœ5 wt % of polymer selected from the group consisting of homopolymer of compound of formula I, homopolymer of compound of formula II and copolymer of compound of formula I and formula II, 10Ëœ30 wt % of anionic salt, 0.5Ëœ10 wt % of colloidal silica, 0.01Ëœ1 wt % of nonionic surfactant, 0.05Ëœ2 wt % of dispersion stabilizer other than the nonionic surfactant, and 40Ëœ75 wt % of water; ii) 1st-polymerizing the mixture with the addition of 0.001Ëœ0.1 wt % of polymerization initiator to said mixture; iii) 2nd polymerizing unreacted monomers in the 1st-polymerized mixture; and iv) adding and mixing 10Ëœ30 wt % of anionic salt to obtained polymers â€ƒwherein R1 is hydrogen atom or methyl; R2 and R3 are each independently alkyl group having 1 to 3 carbon atoms; A1 is oxygen atom or NH; B1 is alkylene group having 2 to 4 carbon atoms or hydropropylene; and X1 is anionic counter ion â€ƒwherein R4 is hydrogen atom or methyl; R5 and R6 are each independently alkyl group having 1 to 2 carbon atoms; R7 is hydrogen atom or alkyl group having 1 to 2 carbon atoms; A is oxygen atom or NH; B2 is alkylene group having 2 to 4 carbon atoms or hydropropylene; and X2 is anionic counter ion.