Organopolysiloxane-polyurea block copolymer release agents
First Claim
1. A pressure-sensitive adhesive tape comprising a backing member having a first front side and a second back side, a layer of pressure-sensitive adhesive on said first side and a low adhesion backsize coating on said second side, said backsize coating comprising an organopolysiloxane-polyurea block copolymer comprising the condensation reaction product of an organopolysiloxane diamine reacted with at least one diisocyanate, and up to 95 weight percent of a diamine or dihydroxy chain extender wherein the organopolysiloxane has little contamination from monofunctional or non-functional silicone as determined by the ability of the tape to functionally adhere (PSTC-1) to a glass plate after being removed from said backsize coating.
0 Assignments
0 Petitions
Accused Products
Abstract
Block copolymers having a repeating unit comprised of polysiloxane and urea segments are prepared by copolymerizing certain diaminopolysiloxanes with diisocyanates. The invention also provides novel diaminopolysiloxanes useful as precursors in the preparation of the block copolymers and a method of making such diaminopolysiloxanes. Pressure-sensitive adhesive compositions comprising the block copolymer are also provided as are sheet materials coated with the same.
-
Citations
27 Claims
- 1. A pressure-sensitive adhesive tape comprising a backing member having a first front side and a second back side, a layer of pressure-sensitive adhesive on said first side and a low adhesion backsize coating on said second side, said backsize coating comprising an organopolysiloxane-polyurea block copolymer comprising the condensation reaction product of an organopolysiloxane diamine reacted with at least one diisocyanate, and up to 95 weight percent of a diamine or dihydroxy chain extender wherein the organopolysiloxane has little contamination from monofunctional or non-functional silicone as determined by the ability of the tape to functionally adhere (PSTC-1) to a glass plate after being removed from said backsize coating.
- 14. A release film for a pressure-sensitive adhesive tape comprising a backing member having a first front side and a second back side, a low adhesion backsize coating on at least said first side, said backsize coating comprising a non-crosslinked organopolysiloxane-polyurea block copolymer comprising the condensation reaction product of an organopolysiloxane diamine reacted with at least one diisocyanate, and up to 95 weight percent of a diamine or dihydroxy chain extender wherein the organopolysiloxane has little contamination from monofunctional or non-functional silicone as determined by the ability of a pressure-sensitive adhesive tape to functionally adhere (PSTC-1) to a glass plate after being removed from said backsize coating.
-
25. A method for forming a release coating on a backing member having a first front face and a second back face comprising the steps of;
-
providing a storage stable solution of a non-crosslinked organopolysiloxane-polyurea block copolymer formed by a condensation reaction of an organopolysiloxane diamine with at least one diisocyanate and up to 95weight percent of a diamine or dihydroxy chain extender with little or no residue contamination from monofunctional or non-functional silicones, coating said storage stable solution onto the backing member, having first and second faces, on at least said first face, and forming an elastomeric film layer release coating on said backing member of said non-crosslinked organopolysiloxane-polyurea block copolymer, without chemical crosslinking of the block copolymer, wherein the film layer is characterized by the ability of a pressure-sensitive adhesive to be removably adhered thereto such that the pressure-sensitive adhesive will functionally adhere (PSTC-1) to a glass plate after being removed from said release coating. - View Dependent Claims (26, 27)
-
Specification