Coating compositions
AssigneesDainichiseika Color & Chemicals Mfg. Co., Ltd., Ukima Coulor & Chemicals Mfg. Co., Ltd.
InventorsEiichi Sugawara, Setsuo Hirose, Yoshinori Konno, Masatoshi Nakajima, Toshiaki Higuchi
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Abstract
Described is a coating composition for the formation of a back coat layer in a magnetic recording medium, which comprises carbon black, a binder and a solvent. The binder is composed of an acrylic-polymer-modified polyurethane resin and a vinyl chloride copolymer having at least one type of terminal groups selected from hydroxyl groups, carboxyl groups or tertiary amino groups.
Claims6
A coating composition for the formation of a back coat layer in a magnetic recording medium, which comprises carbon black, a binder and a solvent,
- said binder consisting essentially of (a) an acrylic-polymer-modified polyurethane resin and (b) a vinyl chloride copolymer having at least one terminal group selected from the group consisting of hydroxyl groups, carboxyl groups and tertiary amino groups;
- and wherein
- said solvent is selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethyl acetate and mixtures thereof;
- and wherein
- said polyurethane resin and said vinyl chloride copolymer are used in a weight ratio of about 5/95 to 50/50, respectively, and further wherein said acrylic-polymer-modified polyurethane resin is made using terminal HO-containing macromonomer as at least a part of the hydroxyl component thereof;
- and
- wherein said terminal HO-containing bifunctional polyol has a molecular weight of about 400-6,000 and being selected from the group consisting of polyether polyols, lactone polyols and polyester polyols.
Dependencies are inferred from the claim text.