Siloxane-modified epoxy resin composition

• US 4,283,513 A
• Filed: 03/03/1980
• Issued: 08/11/1981
• Est. Priority Date: 03/03/1980
• Status: Expired due to Term

• Current Assignee: Toray Silicone Co Ltd (Toray Industries Incorporated)
• Original Assignee: Toray Silicone Co Ltd (Toray Industries Incorporated)
• Inventors: Mikami, Ryuzo
• Primary Examiner(s): BRIGGS SR, WILBERT
• Application Number:
  US06/126,238
• Time in Patent Office: 526 Days
• Field of Search: 525/476
• US Class Current: 525/476
• CPC Class Codes: C08G 59/4085 silicon containing compounds
• CPC Class Codes: C08K 5/09 Carboxylic acids; Metal salts thereof; Anhydrides thereof
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• 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: C08L 83/10 Block- or graft-copolymers containing polysiloxane sequences obtained by polymerising a compound having a carbon-to-carbon double bond on to a polysiloxane C08L51/08, C08L53/00

Abstract

Compositions containing siloxane-modified epoxy resins, alkoxy functional organopolysiloxane and conventional epoxy curing agents are described which have improved resistance to degradation of electrical properties by boiling water and moisture. The compositions consist essentially of (A) siloxane-modified epoxy resin, (B) alkoxy functional organopolysiloxane such as polymethylmethoxysiloxane and (C) curing agents such as carboxylic acid anhydrides.

Claims

1. A siloxane-modified epoxy resin composition consisting essentially of (A) 100 parts by weight of a siloxane-modified epoxy resin prepared by reacting (1) 5 to 70 parts by weight of an alkylphenylpolysiloxane of the general unit formula ##EQU4## wherein each R is an alkyl or a phenyl radical such that the ratio of alkyl radicals to phenyl radicals in the alkylphenylpolysiloxane is 0.3 to 3.0, X is an alkoxy radical or a hydroxyl radical, a is 0.9 to 1.8, and b is 0.01 to 2 with (2) 95 to 30 parts by weight of an epoxy resin having at least two epoxy groups per molecule, (B) 0.01 to 30 parts by weight of an alkoxy group containing organopolysiloxane of the general unit formula ##EQU5## wherein R'"'"' is selected from the group consisting of monovalent hydrocarbon radicals and halogen substituted monovalent hydrocarbon radicals, R² is an alkyl radical, c is 0.9 to 1.8 and d is 0.01 to 2 and (C) a curing agent for (A).

2. A siloxane-modified epoxy resin composition according to claim 1 in which epoxy resin (2) is a polydiglycidyl ether of bisphenol A resin with a molecular weight of 340 to 6000.

3. A siloxane-modified epoxy resin composition according to claim 1 in which siloxane-modified epoxy resin (A) is prepared by reacting 15 to 50 parts by weight (1) with 85 to 50 parts by weight (2) at about 120°

to 210°

C.

4. A siloxane-modified epoxy resin composition according to claim 1 containing 0.3 to 20 parts by weight of (B).

5. A siloxane-modified epoxy resin composition according to claim 4 in which (B) is a polymethylmethoxysiloxane containing an average of 1 methoxy radical per silicon atom.

6. A siloxane-modified epoxy resin composition according to claim 5 in which curing agent (C) is selected from the group consisting of polyhydric carboxylic acids and polyhydric carboxylic acid anhydrides.

7. A siloxane-modified epoxy resin composition according to claim 6 in which the curing agent (C) is trimellitic anhydride.

8. A siloxane-modified epoxy resin composition according to claim 6 in which the curing agent (C) is hexahydrophthalic anhydride.