Polysiloxane-grafted copolymer release coating sheets and adhesive tapes
AssigneeMinnesota Mining and Manufacturing Company
InventorsLawrence M. Clemens, Steven S. Kantner, Mieczyslaw Mazurek
Life of this patent
Estimating the term…
Abstract
Release coating compositions comprising polysiloxane-grafted copolymer and blends thereof with other polymeric materials on sheet materials and the back side of adhesive tapes are provided. Controlled and predictable release is achieved through variation of the number and the length, e.g., the molecular weight, of polysiloxane grafts in the copolymer.
Claims27
A coated sheet material comprising a flexible sheet and a release coating covering at least a portion of one major surface thereof, said coating comprising a copolymer having a vinyl polymeric backbone with a T.sub.g or T.sub.m above about -20.degree. C. and having grafted to said backbone monovalent siloxane weight above about 1,000, the number and composition of said grafted moieties in said copolymer being such as to provide said copolymer a surface release value not greater than about 50N/100 mm.
A roll of pressure-sensitive adhesive coated tape comprising:
- (a) a flexible backing member;
- (b) a pressure-sensitive adhesive coating one major surface of said backing member;
- and
- (c) a release coating on the opposite major surface of said backing member, said release coating comprising a copolymer having a vinyl polymeric backbone with a T.sub.g or T.sub.m above about -20.degree. C. and having grafted to said backbone monovalent siloxane polymeric moieties having a number average molecular weight above about 1,000, the number and composition of said grafted moieties in said copolymer being such as to provide said copolymer a surface release value not greater than about 50 N/100 mm.
A tape comprising:
- (a) a flexible backing member;
- (b) a pressure-sensitive adhesive coating one major surface of said backing member;
- and
- (c) adhered to the pressure-sensitive coating, a release liner comprising a flexible sheet coated over the major surface adhered to the pressure-sensitive coating with a release coating comprising a copolymer having a vinyl polymeric backbone with a T.sub.g or T.sub.m above about -20.degree. C. and having grafted to said backbone monovalent siloxane polymeric moieties having a number average molecular weight above about 1,000 the number and composition of said grafted moieties in said copolymer being such as to provide said copolymer a surface release value not greater than about 50N/100 mm.
The tape of claim I9 wherein said copolymer is cross-linked.
A transfer tape comprising a film of pressure-sensitive adhesive between release liners, at least one of said release liners being coated with a release coating comprising a copolymer having a vinyl polymeric backbone with a T.sub.g or T.sub.m above about -20.degree. C. and having grafted to said backbone monovalent siloxane polymeric moieties having a number average molecular weight above about 1,000, the number and composition of said grafted moieties in said copolymer being such as to provide said copolymer a surface release value not greater than about 50N/100 mm.
Dependencies are inferred from the claim text.