EP0652257A2
Expired / Lapsed
EP
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Silicone release composition
Assignee: Dow Silicones UK Ltd
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Filing: 1994-11-02
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Granted: —
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Expires: 2014-11-02
Abstract
Abstract A release modifier which comprises (i) a MQ resin consisting essentially of units of the formulae SiO 2 and R 3 SiO ½ wherein R denotes a monovalent hydrocarbon group having up to 3 carbon atoms, a hydrogen atom, a c 2-5 alkenyl group of the formula -R'CH=CH 2 , provided there is at least one group - R'CH=CH 2 present per MQ molecule and (ii) a α,ω-diolefin having the general formula CH 2 =CH-(CH 2 ) n -CH=CH 2 , wherein n denotes an integer with a value of from 4 to 18 gives improved release force over prior art controlled release additives. Also claimed is a solventless release composition based on siloxanes having SiH groups and a catalyst in addition to the release modifier.
Inventors
- 👤 Simon Ronald Hurford
- 👤 Bhukandas Parbhoo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:44
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/01; C08L; C08L83/00; C08L83/04; C09; C09D; C09D183/00; C09D183/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
102 words
A release modifier which comprises (i) a MQ resin consisting essentially of units of the formulae SiO₂ (Q) and R₃SiO ½ (M) wherein R denotes a monovalent hydrocarbon group having up to 3 carbon atoms, a hydrogen atom, an alkenyl group of the formula -R'CH=CH₂, wherein R' denotes an alkylene group of from 0 to 3 carbon atoms, provided there is at least one group -R'CH=CH₂ present per MQ molecule and (ii) an olefin characterised in that the olefin is a α,ω-diolefin having the general formula CH₂=CH-(CH₂) n -CH=CH₂, wherein n denotes an integer with a value of from 4 to 18.
Claim 2
Dependent Claim
36 words
A release modifier according to Claim 1 further characterised in that the MQ resin has a ratio of M units to Q units of from 0.6/1 to 1.1/1 and in that the alkenyl group is vinyl.
Claim 3
Dependent Claim
29 words
A release modifier according to Claims 1 or 2 further characterised in that it is solventless and also comprises a linear alkenyl-substituted polydimethylsiloxane material, an inhibitor and/or a catalyst.
Claim 4
Dependent Claim
33 words
A release modifier according to Claims 1 or 3 further characterised in that it comprises from 40 to 80% by weight of the MQ resin and from 10 to 50% of the α,ω-diolefin.
Claim 5
Dependent Claim
158 words
A solventless release composition comprising (A) a release modifier which comprises (i) a MQ resin consisting essentially of units of the formulae SiO₂ (Q) and R₃SiO ½ (M) wherein R denotes a monovalent hydrocarbon group having up to 3 carbon atoms, a hydrogen atom, an alkenyl group of the formula -R'CH=CH₂, wherein R' denotes an alkylene group of from 0 to 3 carbon atoms provided there is at least one group R'CH=CH₂, present per MQ molecule and (ii) an olefin, (B) an organo-silicon compound having at least three silicon-bonded hydrogen atoms per molecule; (C) an effective amount of a precious metal catalyst capable of promoting the addition reaction between alkenyl or oxyalkenyl groups and silicon-bonded hydrogen groups and (D) optionally a diorganopolysiloxane having at least 2 alkenyl-functional silicon-bonded substituents characterised in that the olefin (A) (ii) is α,ω-diolefin having the general formula CH₂=CH-(CH₂) n -CH=CH₂, wherein n denotes an integer with a value of from 4 to 18.
Claim 6
Dependent Claim
77 words
A solventless release composition according to Claim 5 further characterised in that the organosilicon compound (B) has the general formula R²₂R³SiO-[R²₂SiO] m -[R²HSiO] n -SiR²₂R³ or wherein R² denotes an alkyl or aryl group having up to 8 carbon atoms, R³ denotes a group R² or a hydrogen atom, m has a value of from 0 to 20, n has a value of from 1 to 70, and there are at least 3 silicon-bonded hydrogen atoms present.
Claim 7
Dependent Claim
25 words
A solventless release composition according to Claim 5 or Claim 6 further characterised in that the number ratio of SiH/alkenyl is from 1.1/1 to 1.8/1.
Claim 8
Dependent Claim
106 words
A solventless release composition according to any of Claims 5 to 7 further characterised in that Component (D) is present and is a polydiorganosiloxane having the general formula X₂Y°SiO-[X₂SiO] x -[XYSiO] y -SiX₂Y°, wherein each X denotes independently, a phenyl radical or a saturated hydrocarbon group having 1 to 6 carbon atoms, at least 90% being methyl groups, Y denotes an alkenyl group having up to 6 carbon atoms, Y° denotes a group Y or a group X and the average value of the sum total of x and y is such that the resulting viscosity of the polydiorganosiloxane is at least 10 mPa.s at 25°C.
Claim 9
Dependent Claim
39 words
A solventless release composition according to any of Claims 5 to 8 further characterised in that the weight percentage of component (A) based on the total weight of components (A), (C) and (D) combined is from 10 to 80%.
Claim 10
Dependent Claim
35 words
A solventless release composition according to any of Claims 5 to 9 further characterised in that it also comprises one or more ingredients selected from the group consisting of cure inhibitors and bath life extenders.
Claim 11
Dependent Claim
38 words
A process of coating a substrate comprising applying to the substrate a solventless release composition and thereafter causing the composition to cure characterised in that the release composition is according to any one of Claims 5 to 10.
Claim 12
Dependent Claim
49 words
A process according to Claim 11 further characterised in that the substrate is flexible, the composition is applied to the substrate in a layer of 0.1 to 2.0 grams per square metre of surface and the curing is effected by heating the coated substrate to a temperature below 200°C.
References Cited (Backward Citations)
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