ADHESION PROMOTING ADDITIVE

• US 20090247680A1
• Filed: 05/31/2007
• Published: 10/01/2009
• Est. Priority Date: 06/06/2006
• Status: Abandoned Application

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Hayes, James T.
• Application Number:
  US12/303,152
• Publication Number:
  US 20090247680A1
• Time in Patent Office: Days
• US Class Current: 524/314
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/14 containing silicon bound to oxygen-containing groups C08G77/045 takes precedence
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C09D 183/04 Polysiloxanes

Abstract

A release coating additive for a release coating that provides adhesion to polymeric films and that has improved storage stability is provided. Also provided is a release liner having a release coating on a polyester substrate wherein the release coating composition comprises an adhesion promoting additive having improved storage stability.

Claims

1. An adhesion promoting additive for curable silicone release coatings, the additive comprising (a) a polysiloxane having the formula (R_aSiO_(4-a)/2)_n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule;

and (b) a storage stabilizer comprising an inhibitor, wherein the additive exhibits improved storage stability.

2. The adhesion promoting additive of claim 1 wherein the inhibitor is chosen from alkynyl alcohols or unsaturated hydrocarbon diestars.

3. The adhesion promoting additive of claim 1 wherein the inhibitor comprises 3,5-dimethyl-1-hexyn-3-ol.

4. The adhesion promoting additive of claim 1 wherein the inhibitor comprises diallyl maleate.

5. The adhesion promoting additive of claim 1 wherein the inhibitor is present in an amount from about 0.1% to about 3% by weight, based on the weight of the polysiloxane.

6. The adhesion promoting additive of claim 1 wherein the inhibitor is present in an amount from about 0.5% to about 1% by weight, based on the weight of the polysiloxane.

7. The adhesion promoting additive of claim 1 wherein the polysiloxane comprises γ

-glycidoxypropyl triethoxysilane.

8. A release composition comprising the adhesion promoting additive of claim 1.

9. A release liner comprising a substrate and a curable release composition coated thereon, the curable release composition comprising the adhesion promoting additive of claim 1.

10. The release liner of claim 9 wherein the substrate comprises polyester.

11. A method of making a storage stable adhesion promoting additive for curable silicone release coatings comprising (a) providing adhesion promoting polysiloxane having the formula (RaSiO_(4-a)/2)_n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule;

and (b) adding a storage stabilizer comprising an inhibitor to the polysiloxane, wherein the additive exhibits improved storage stability.

12. The method of claim 11 wherein the inhibitor is chosen from alkynyl alcohols or unsaturated hydrocarbon diesters.

13. The method of claim 11 wherein the inhibitor comprises 3,5-dimethyl-1-hexyn-3-ol.

14. The method of claim 11 wherein the inhibitor comprises diallyl maleate.

15. The method of claim 11 wherein the inhibitor is added in an amount from about 0.1% to about 3% by weight, based on the weight of the polysiloxane.