Pressure sensitive adhesive/release liner laminate

• US 5,082,706 A
• Filed: 11/23/1988
• Issued: 01/21/1992
• Est. Priority Date: 11/23/1988
• Status: Expired due to Term

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: Tangney, Thomas J.
• Primary Examiner(s): Davis, Jenna
• Application Number:
  US07/276,178
• Time in Patent Office: 1,154 Days
• Field of Search: 428/40, 428/352, 428/355, 428/447
• US Class Current: 428/40.7
• 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 183/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
• CPC Class Codes: C09J 183/04 Polysiloxanes
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• CPC Class Codes: Y10T 428/1429 Fluorine
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/2852 Adhesive compositions
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

Addition-curable silicone pressure sensitive adhesives can be covered with an addition-cured fluorosilicone release coating to provide a releasable laminate. The release force of the laminate is low to moderate and the subsequent adhesion and tack of the adhesive is high and all three values are stable with time. The laminate can be prepared by contacting the release coating with cured adhesive or by curing the adhesive in contact with the release coating.

Claims

1. As an article of manufacture a laminate comprising a layer of pressure sensitive adhesive and at least one liner adhered to at least a portion of said layer;

said pressure sensitive adhesive being the reaction product of components comprising

(a) 30 to 70 weight parts of a polydiorganosiloxane having the general formula R¹ R₂ SiO(R₂ SiO)_n SiR₂ R¹ wherein each R is a monovalent hydrocarbon radical, each R₁ is an alkenyl radical and n is an integer,

(b) 70 to 30 weight parts of an organopolysiloxane which is constituted of R²₃ SiO_1/2 units and SiO₂ units in a molar ratio in the range of R²₃ SiO_1/2 units and SiO₂ units in a molar ratio in the range of 0.6;

1 to 0.9;

1, wherein R² is selected from the group consisting of alkyl radicals, alkenyl radicals, and the hydroxyl radical, and methyl radicals comprise at least 95 mol percent of all R² radicals,

(c) an organohydrogenpolysiloxane free of aliphatic unsaturation having an average of at least 2 silicon-bonded hydrogen atoms in each molecule, in a quantity sufficient to provide from 1 to 40 silicon-bonded hydrogen atoms per alkenyl radical in component (a), and

(d) a platinum-containing catalyst in a quantity sufficient to provide 0.1 to 1,000 weight parts platinum for each one million weight parts of the combined quantity of Components (a) through (c);

Component (a) having a viscosity of at least 500,000 centipoise at 25°

C.;

component (b) having a silicon-bonded hydroxyl content of no more than 1 weight percent; and

Component (c) having the formula Me₃ SiO(MeHSIO)_a (Me₂ SiO)_b SiOMe₃ wherein a has an average value of at least 3 and b has an average value of 0 or more; and

said liner comprising a backing bearing an adhesive-releasing coating durably adhered thereto which is the reaction product of components consisting essentially of

(e) a fluorosilicone polymer having the formula ViMe₂ SiO(Me₂ SiO)_x {R³ QSi(Me)O}_y (MeViSiO)_Z SiMe₂ Vi, wherein Me denotes methyl, Vi denotes vinyl, R³ Q has a formula CF₃ CF₂ CF₂ CF₂ CH₂ CH₂ and the sum of x+y+z has a value of about 2500, and containing from 0.1 to 1.0 mol percent vinyl-containing siloxane units and at least 30 mol percent siloxane units which bear R³ Q radicals,

(f) an organohydrogenpolysiloxane having the formula Me₃ SiO(MeHSiO)₂₈ {R³ QSi(Me)}₁₂ SiMe₃ wherein R³ Q has the formula CF₃ CF₂ CF₂ CF₂ CH₂ CH₂ and Me denotes methyl, in a quantity sufficient to provide 1-40 silicon-bonded hydrogen atoms per vinyl radical in Component (e), and

(g) a platinum-containing catalyst in a quantity sufficient to provide 0.1 to 1,000 weight parts platinum for each one million weight parts of the combined quantity of Components (e) and (f).

2. An article according to claim 1 wherein the laminate has a release value for the pressure sensitive adhesive layer/adhesive releasing coating interface of less than 200 grams per inch and the pressure sensitive adhesive has a subsequent adhesion of at least 1200 grams per inch and a subsequent tack of at least 1100 grams per square centimeter.

3. An article according to claim 1 further comprising at least one support durably adhered to at least a portion of said layer of pressure sensitive adhesive.

4. An article according to claim 3 wherein the backing and support are independently selected from the group consisting of polymeric film, metal foil, polymeric film-coated metal foil, paper and polymeric film-coated paper.

5. An article according to claim 1 further comprising at least two liners adhered to at least two portions of said layer of pressure sensitive adhesive.

6. An article according to claim 1 wherein the Component (a) has the formula ViMe₂ SiO(Me₂ SiO)_n SiMe₂ Vi wherein Me denotes the methyl radical, Vi denotes the vinyl radical and n has a value sufficient to provide a viscosity of at least 10,000,000 centipoise at 25°

C. for Component (a);

Component (b) has a silicon-bonded hydroxy content of no more than 0.6 weight percent and R² denotes the methyl radical; and

Component (c) has the formula Me₃ SiO(MeHSiO)_a SiMe₃ wherein a has a value of from 30-70.