Low temperature silicone gel

• US 4,374,967 A
• Filed: 02/08/1982
• Issued: 02/22/1983
• Est. Priority Date: 07/06/1981
• Status: Expired due to Term

• Current Assignee: Dow Corning Corporation (Dow, Inc.)
• Original Assignee: Dow Corning Corporation (Dow, Inc.)
• Inventors: Brown, Paul L., Maxson, Myron T., Lee, Chi-Long
• Primary Examiner(s): Marquis, Melvyn I.
• Application Number:
  US06/346,804
• Time in Patent Office: 379 Days
• Field of Search: 528/15, 528/31, 528/32, 525/478
• US Class Current: 528/15
• CPC Class Codes: C08G 77/045 containing less than 25 silicon atoms
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic 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: C08L 83/04 Polysiloxanes

Abstract

This invention relates to a novel low-temperature dielectric silicone gel which is the reaction product of a polyorganosiloxane consisting essentially of Me₂ SiO, MeSiO₁.5, Me₃ SiO₀.5 and Me₂ ViSiO₀.5 ; an organohydrogensiloxane and a platinum catalyst.

Claims

1. A curable siloxane composition comprising an intimate mixture consisting essentially of:

(1) a polyorganosiloxane consisting essentially of 80 to 96.5 mol % of (CH₃)₂ SiO, 2.0 to 10.0 mol % of CH₃ SiO₁.5, 1.25 to 6.0 mol % of (CH₃)₃ SiO₀.5, and 0.25 to 4.0 mol % of (CH₃)₂ (CH₂ ═

CH)SiO₀.5 ;

(2) an organohydrogensiloxane having an average of more than one silicon-bonded hydrogen atom per molecule and no more than one silicon-bonded hydrogen atom per silicon atom and organic radicals selected from the group consisting of alkyl radicals having from one to six carbon atoms per radical, phenyl and 3,3,3-trifluoropropyl, said organohydrogensiloxane providing an average of 0.2 to 5.0 moles of silicon-bonded hydrogen per mole of silicon-bonded vinyl; and

(3) a platinum catalyst.

2. The curable siloxane composition according to claim 1 wherein the polyorganosiloxane consists essentially of 87 to 94 mol % of (CH₃)₂ SiO, 3 to 6 mol % of CH₃ SiO₁.5, 2.5 to 5 mol % of (CH₃)₃ SiO₀.5, and 0.5 to 2.0 mol % of (CH₃)₂ (CH₂ ═

CH)SiO₀.5.

3. The curable siloxane composition according to claim 2 wherein the polyorganosiloxane consists essentially of 92 to 94 mol % of (CH₃)₂ SiO, 3 to 4 mol % of CH₃ SiO₁.5, 2.5 to 3 mol % of (CH₃)₃ SiO₀.5, and 0.5 to 1 mol % of (CH₃)₂ (CH₂ ═

CH)SiO₀.5.

4. The curable siloxane composition according to claim 2 wherein the polyorganosiloxane consists essentially of 90.5 mol % of (CH₃)₂ SiO, 5.0 mol % of CH₃ SiO₁.5, 3.8 mol % of (CH₃)₃ SiO₀.5, and 0.7 mol % of (CH₃)₂ (CH₂ ═

CH)SiO₀.5.

5. The curable siloxane composition according to claim 1, 2, 3, or 4 wherein the organohydrogensiloxane is H(CH₃)₂ Si[OSi(CH₃)₂ ]_x OSi(CH₃)₂ H, wherein x is within the range of 5 to 20.

6. The curable siloxane composition according to claim 1, 2, 3, or 4 wherein the organohydrogensiloxane is H(CH₃)₂ Si[OSi(CH₃)₂ ]_x OSi(CH₃)₂ H wherein x is within the range of 5 to 20, and said organohydrogensiloxane provides an average of 0.5 to 0.95 moles of silicon-bonded hydrogen per mole of silicon-bonded vinyl.

7. The curable siloxane composition according to claim 1 wherein the platinum catalyst provides between 5 and 10 parts of the platinum atom per million parts of the total formulation.

8. The curable siloxane composition according to claim 6 wherein the platinum catalyst provides between 5 and 10 parts by weight of the platinum atom per million parts by weight of the total formulation.

9. The cured product of claim 1, 2, 3, or 4.

10. The cured product of claim 8.