Film-forming organopolysiloxane composition

• US 5,246,995 A
• Filed: 07/11/1991
• Issued: 09/21/1993
• Est. Priority Date: 07/19/1990
• Status: Expired due to Fees

• Current Assignee: Dow Corning Toray Company Limited (Dow, Inc.), Toray Dow Corning Silicone
• Original Assignee: Dow Corning Toray Company Limited (Dow, Inc.)
• Inventors: Motomura, Hideyuki, Murakami, Ichiro
• Primary Examiner(s): Bleutge, John C.
• Assistant Examiner(s): Dean, Karen A.
• Application Number:
  US07/728,452
• Time in Patent Office: 803 Days
• Field of Search: 525/106, 525/477, 524/588, 524/451, 524/265, 524/447, 524/268, 528/18, 528/34, 528/901, 528/32
• US Class Current: 524/265
• CPC Class Codes: C08G 77/16 to hydroxyl groups
• CPC Class Codes: C08G 77/18 to alkoxy or aryloxy groups
• CPC Class Codes: C08G 77/44 containing only polysiloxane sequences
• CPC Class Codes: C08J 2321/00 Characterised by the use of unspecified rubbers
• CPC Class Codes: C08J 2483/00 Characterised by the use 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; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08L 2666/44 Silicon-containing compounds
• 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
• CPC Class Codes: C09D 183/04 Polysiloxanes
• CPC Class Codes: Y10S 528/901 Room temperature curable silicon-containing polymer

Abstract

A film-forming organopolysiloxane composition is disclosed which imparts an excellent releaseability and lubricity to the surface of various types of rubber materials. The composition comprises a solvent dispersion of

(a) 50 to 90 weight percent of a block organopolysiloxane copolymer;

(b) 2 to 50 weight percent of a compound selected from the group consisting of an organosilane or a partial hydrolyzate thereof;

(c) 4 to 40 weight percent of a mixture an epoxy group-containing organoalkoxysilane and an alkenyl group-containing organoacetoxysilane in a weight ratio of 1:9 to 9:1 or a condensation-reaction product thereof;

(d) 0.1 to 10 weight percent of an hydroxy or alkoxy terminated diorganopolysiloxane; and

(f) 0.1 to 10 weight percent of a condensation-reaction catalyst.

Claims

1. A film-forming organopolysiloxane composition consisting essentially of an organic solvent dispersion of

(a) 50 to 90 weight percent of a block organopolysiloxane copolymer composed of

(i) 10 to 80 weight percent of an organopolysiloxane resin composed of

View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)

2. The composition according to claim 1, further comprising a filler selected from the group consisting of an organic micropowder and an inorganic micropowder, wherein said filler is present at a level of up to 10 weight percent based on the 50 to 90 weight percent of said block copolymer (a).

3. The composition according to claim 1, wherein R is selected from the group consisting of methyl and phenyl radicals.

4. The composition according to claim 3, wherein R² is a methyl radical and R¹ is selected from the group consisting of methoxy and ethoxy groups.

5. The composition according to claim 4, wherein said diorganopolysiloxane (d) is polydimethylsiloxane.

6. The composition according to claim 5, wherein said compound (b) is selected from the group consisting of methyltris(methyl ethyl ketoxime)silane, vinyltris(methyl ethyl ketoxime)silane, methylmethoxydi(methyl ethyl ketoxime)silane, diethoxydi(methyl ethyl ketoxime)silane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, mixtures thereof and partial hydrolysis-condensates thereof.

7. The composition according to claim 6, wherein said epoxy group-containing organoalkoxysilane of said component (c) is selected from the group consisting of

gamma-glycidoxypropyltrimethoxysilane,

gamma-glycidoxypropyltriethoxysilane and

beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane

and said alkenyl group-containing organoacetoxysilane is selected from the group consisting of vinyltriacetoxysilane and allyltriacetoxysilane.

8. The composition according to claim 7, wherein said film-forming organopolysiloxane composition comprises an organic solvent dispersion of 50 to 90 weight percent of said block organopolysiloxane copolymer (a), 5 to 40 weight percent of said compound (b), 5 to 15 weight percent of said component (c), 0.1 to 5 weight percent of said diorganopolysiloxane (d), 0.3 to 5 weight percent of said condensation-reaction catalyst (f) and the weight ratio of said epoxy group-containing organoalkoxysilane to said alkenyl group-containing organoacetoxysilane is 3:

7 to 7;

3.

9. The composition according to claim 6, further comprising a filler selected from the group consisting of an organic micropowder and an inorganic micropowder, wherein said filler is present at a level of up to 10 weight percent based on the 50 to 90 weight percent of said block copolymer (a).

10. The composition according to claim 7, further comprising a filler selected from the group consisting of an organic micropowder and an inorganic micropowder, wherein said filler is present at a level of up to 10 weight percent based on the 50 to 90 weight percent of said block copolymer (a).