Patent US4842902A successfully refreshed from Google Patents.
US4842902A
Expired / Lapsed
US
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Pressure sensitive adhesive release liner
Assignee: Dow Silicones Corp
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Filing: 1987-12-21
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Granted: 1989-06-27
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Expires: 2007-12-21
Abstract
Abstract Pressure sensitive adhesives can be protected with a releasable liner having a cured fluoroalkyl silicone coating which contains as little as two percent fluoroalkyl-substituted siloxane units. In a preferred embodiment of this invention silicone pressure sensitive adhesives can be solvent-cast, and even cured, directly onto the release surface of the liner and can be removed from the protective liner with a force of no more than 400 grams per inch. The fluoroalkyl silicone copolymers of this invention are prepared by a process which involves the preparation of a cohydrolyzate of fluoroalkyl-containing and fluoroalkyl-free siloxane units, followed by further polymerization of the cohydrolyzate with other siloxane units.
Inventors
- 👤 Paul L. Brown
- 👤 David L. Stickles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:20
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/04; C08L83/08; Y; Y10; Y10T; Y10T428/00; Y10T428/14; Y10T428/1424; Y10T428/1429; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
261 words
A method for providing a substrate with a coating that will release pressure sensitive adhesives, said method comprising (i) applying to the surface of said substrate a coating of a coating composition comprising a curable mixture consisting essentially of (A) a fluorosilicone polymer containing an average of at least two silicon-bonded curing radicals per molecule selected from the group consisting of hydrogen, hydroxyl and alkenyl and at least 2 mol percent, based on the total number of siloxane units in the fluorosilicone polymer, of fluorinated siloxane units, any remaining siloxane units in the polymer being non-fluorinated siloxane units; said fluorinated siloxane units having the formula (RQ)(R').sub.a (Z).sub.b SiO.sub.(3-a-b)/2 and said non-fluorinated siloxane units having the formula (R').sub.c (Z).sub.d SiO.sub.(4-c-d)/2 where, in said fluorinated and non-fluorinated siloxane units, R denotes a perfluoroalkyl radical having from 4 to 8 carbon atoms and, additionally, 2 to 3 carbon atoms when the fluorosilicone polymer contains less than 90 mol percent fluorinated siloxane units and 1 carbon atom when the fluorosilicone polymer contains from 7 to 10 mol percent fluorinated siloxane units, Q denotes a divalent hydrocarbon, hydrocarbon ether or hydrocarbon thioether radical linking the R radical to a silicon atom through at least 2 carbon atoms, R' denotes a silicon-bonded, monovalent hydrocarbon radical free of aliphatic unsaturation, Z denotes said silicon-bonded curing radical, a=0 to 2, b=0 to 2, a+b=0 to 2, c=0 to 3, d=0 to 3 and c+d=0 to 3 and, (B) an effective amount of a curing agent for the fluorosilicone polymer and, (ii) thereafter causing the applied curable mixture to cure.
Claim 2
Independent Claim
261 words
A method for providing a substrate with a coating that will release pressure sensitive adhesives, said method comprising (i) applying to the surface of said substrate a coating of a coating composition comprising a curable mixture consisting essentially of (A) a fluorosilicone polymer containing an average of at least two silicon-bonded curing radicals per molecule selected from the group consisting of hydrogen, hydroxyl and alkenyl and at least 2 mol percent, based on the total number of siloxane units in the fluorosilicone polymer, of fluorinated siloxane units, any remaining siloxane units in the polymer being non-fluorinated siloxane units; said fluorinated siloxane units having the formula (RQ)(R').sub.a (Z).sub.b SiO.sub.(3-a-b)/2 and said non-fluorinated siloxane units having the formula (R').sub.c (Z).sub.d SiO.sub.(4-c-d)/2 where, in said fluorinated and non-fluorinated siloxane units, R denotes a perfluoroalkyl radical having from 4 to 8 carbon atoms and, additionally, 2 to 3 carbon atoms when the fluorosilicone polymer contains less than 90 mol percent fluorinated siloxane units and 1 carbon atom when the fluorosilicone polymer contains from 7 to 10 mol percent fluorinated siloxane units, Q denotes a divalent hydrocarbon, hydrocarbon ether or hydrocarbon thioether radical linking the R radical to a silicon atom through at least 2 carbon atoms, R' denotes a silicon-bonded, monovalent hydrocarbon radical free of aliphatic unsaturation, Z denotes said silicon-bonded curing radical, a=0 to 2, b=0 to 2, a+b=0 to 2, c=0 to 3, d=0 to 3 and c+d=0 to 3 and, (B) an effective amount of a curing agent for the fluorosilicone polymer and, (ii) thereafter causing the applied curable mixture to cure.
Claim 3
Dependent Claim
65 words
A method according to claim 1 wherein the fluorosilicone polymer consists of siloxane units selected from the group consisting of YMe 2 SiO 1/2 siloxane units, RQMeYSiO 1/2 siloxane units, MeYSiO 2/2 siloxane units and RQYSiO 2/2 siloxane units: wherein Y denotes Me or A. A denotes an omega-alkenyl radical and Me denotes the methyl radical and the curing agent comprises an organohydrogen silicon compound.
Claim 4
Dependent Claim
121 words
A method according to claim 2 for providing a substrate with a coating that will release silicone pressure sensitive adhesives with a force of no more than 200 grams per inch, wherein the fluorosilicone polymer has the formula YMe.sub.2 SiO(Me.sub.2 SiO).sub.x [RCH.sub.2 CH.sub.2 Si(Me)O].sub.y (MeASiO).sub.z SiMe.sub.2 Y wherein the values of x, y and z are each greater than zero and are such that the fluorosilicone polymer contains from 1 to 10 mol percent alkenyl-containing siloxane units, at least 5 mol percent fluorinated siloxane units and the balance dimethylsiloxane units, and the curing agent comprises a platinum-containing hydrosilylation catalyst and a methylhydrogenpolysiloxane having the formula Me 3 SiO(MeHSiO) e SiMe 3 wherein e has a value of from 30 to 70.
Claim 5
Dependent Claim
25 words
A method according to claim 3 wherein the ratio of silicon-bonded hydrogen atoms to silicon-bonded alkenyl radicals has a value of from 1/1 to 4/1.
Claim 6
Dependent Claim
26 words
A method according to claim 4 wherein the fluorinated siloxane units have the formula (CF.sub.3 CF.sub.2 CF.sub.2 CF.sub.2 CH.sub.2 CH.sub.2)(CH.sub.3)SiO.sub.2/2 and all A radicals are vinyl.
Claim 7
Dependent Claim
140 words
A method according to claim 2 for providing a substrate with a coating that will release silicone pressure sensitive adhesives, solvent-cast and heat-cured thereon, with a force of no more than 200 grams per inch, wherein the fluorosilicone polymer has the formula YMe.sub.2 SiO(Me.sub.2 SiO).sub.x [RCH.sub.2 CH.sub.2 Si(Me)O].sub.y (MeASiO).sub.z SiMe.sub.2 Y wherein the value of x, y and z are each greater than zero and are such that the fluorosilicone polymer contains from 3 to 7 mol percent alkenyl containing siloxane units, from 20 to 50 mol percent fluorinated siloxane units and the balance dimethylsiloxane units, and has a viscosity of from 100 to 1,000 centistokes at 25° C. and the curing agent comprises a platinum-containing hydrosilylation cataylst and a methylhydrogenpolysiloxane having the formula Me 3 SiO(MeHSiO) e SiMe 3 wherein e has a value of from 30 to 70.
Claim 8
Dependent Claim
25 words
A method according to claim 6 wherein the ratio of silicon-bonded hydrogen atoms to silicon-bonded alkenyl radicals has a value of from 1/1 to 4/1.
Claim 9
Dependent Claim
26 words
A method according to claim 7 wherein the fluorinated siloxane units have the formula (CF.sub.3 CF.sub.2 CF.sub.2 CF.sub.2 CH.sub.2 CH.sub.2)(CH.sub.3)SiO.sub.2/2 and all A radicals are vinyl.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |