Composition for forming an article having excellent reflectance and flame retardant properties and article formed therefrom

Patent metadata

Field	Value
Publication number	US-9507054-B2
Application number	US-201314655828-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 27, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A composition comprises (A) a silicone resin; (B) an organosilicon compound; (C) a hydrosilylation catalyst; and (D) a flame retardant component comprising aluminum hydroxide. The composition further comprises (E) a reflective component different from component (D) and comprising titanium dioxide. The composition forms articles having excellent physical properties, including reflectance, flame retardant properties, and self-extinguishing properties. An article formed from the composition and a method of forming a molded article are also provided.

First claim

What is claimed is:

1. A hydrosilylation-curable silicone composition for forming an article, said composition comprising:
(A) a silicone resin comprising R 1 SiO 3/2 units and/or SiO 4/2 units in combination with R 1 3 SiO 1/2 units and/or R 1 2 SiO 2/2 units, wherein R 1 is independently a substituted or unsubstituted C 1 to C 10 hydrocarbyl group free of aliphatic unsaturation, an alkenyl group, or a hydrogen atom, with the proviso that said silicone resin (A) includes at least two silicon-bonded alkenyl groups or at least two silicon-bonded hydrogen atoms per molecule, wherein the R 1 SiO 3/2 units and/or SiO 4/2 units are present in at least 10 mol % based on all units in the silicone resin (A); (B) an organosilicon compound having an average of at least two silicon-bonded hydrogen atoms or at least two silicon-bonded alkenyl groups per molecule, with the proviso that when said silicone resin (A) includes silicon-bonded alkenyl groups, said organosilicon compound (B) includes at least two silicon-bonded hydrogen atoms per molecule, and when said silicone resin (A) includes silicon-bonded hydrogen atoms, said organosilicon compound (B) includes at least two silicon-bonded alkenyl groups per molecule;
(C) a hydrosilylation catalyst;
(D) a flame retardant component comprising aluminum hydroxide in an amount to provide at least 15 parts by weight of said aluminum hydroxide in said composition based on 100 parts by weight of said composition;
(E) a reflective component different from component (D) and comprising titanium dioxide in an amount to provide at least 2 and no more than 15 parts by weight of said titanium dioxide in said composition based on 100 parts by weight of said composition.

2. The composition of claim 1 further comprising one or both of (F) a filler different from components (D) and (E), and (G) a fluid organopolysiloxane polymer having at least two silicon-bonded alkenyl groups per molecule or at least two silicon-bonded hydrogen atoms per molecule.

3. The composition of claim 2 wherein component (G) is present in said composition in an amount of at least 20 parts by weight based on 100 parts by weight of said composition.

4. The composition of claim 2 wherein component (F) is a thermally conductive filler.

5. The composition of claim 4 , wherein component (F) is selected from zinc oxide, boron nitride, and alumina.

6. The composition of claim 1 wherein said silicone resin (A) includes at least two silicon-bonded alkenyl groups per molecule and said organosilicon compound (B) includes at least two silicon-bonded hydrogen atoms per molecule.

7. The composition of claim 1 wherein component (D) further comprises magnesium hydroxide.

8. The composition of claim 7 wherein said magnesium hydroxide of component (D) is present in said composition in an amount of at least 5 parts by weight based on 100 parts by weight of said composition.

9. The composition of claim 1 wherein said aluminum hydroxide of component (D) is present in said composition in an amount of at least 20 parts by weight based on 100 parts by weight of said composition.

10. The composition of claim 1 wherein said titanium dioxide of component (E) is present in said composition in an amount of no more than 8 parts by weight based on 100 parts by weight of said composition.

11. A method of forming a molded article, said method comprising:
disposing the composition of claim 1 into a mold; and
curing the composition in the mold to form the molded article.

12. A hydrosilylation-curable silicone composition for forming an article, said composition comprising:
(A) a silicone resin comprising R 1 SiO 3/2 units and/or SiO 4/2 units in combination with R 1 3 SiO 1/2 units and/or R 1 2 SiO 2/2 units, wherein R 1 is independently a substituted or unsubstituted C 1 to C 10 hydrocarbyl group free of aliphatic unsaturation, an alkenyl group, or a hydrogen atom, with the proviso that said silicone resin (A) includes at least two silicon-bonded alkenyl groups or at least two silicon-bonded hydrogen atoms per molecule;
(B) an organosilicon compound having an average of at least two silicon-bonded hydrogen atoms or at least two silicon-bonded alkenyl groups per molecule, with the proviso that when said silicone resin (A) includes silicon-bonded alkenyl groups, said organosilicon compound (B) includes at least two silicon-bonded hydrogen atoms per molecule, and when said silicone resin (A) includes silicon-bonded hydrogen atoms, said organosilicon compound (B) includes at least two silicon-bonded alkenyl groups per molecule;
(C) a hydrosilylation catalyst;
(D) a flame retardant component comprising aluminum hydroxide in an amount to provide at least 15 parts by weight of said aluminum hydroxide in said composition based on 100 parts by weight of said composition; and
(E) a reflective component different from component (D) and comprising titanium dioxide in an amount to provide at least 2 and no more than 15 parts by weight of said titanium dioxide in said composition based on 100 parts by weight of said composition,
wherein: said silicone resin (A) comprises an MQ resin or,
said organosilicon compound (B) comprises an MQ resin.

13. The composition of claim 12 further comprising (F) a filler different from components (D) and (E).

14. The composition of claim 12 wherein component (D) further comprises magnesium hydroxide.

15. The composition of claim 14 wherein said magnesium hydroxide of component (D) is present in said composition in an amount of at least 5 parts by weight based on 100 parts by weight of said composition.

16. The composition of claim 12 wherein said aluminum hydroxide of component (D) is present in said composition in an amount of at least 20 parts by weight based on 100 parts by weight of said composition.

17. The composition of claim 12 wherein said titanium dioxide of component (E) is present in said composition in an amount of no more than 8 parts by weight based on 100 parts by weight of said composition.

18. A method of forming a molded article, said method comprising:
disposing the composition of claim 12 into a mold; and
curing the composition in the mold to form the molded article.

19. A device comprising an article formed from a hydrosilylation-curable silicone composition comprising:
(A) a silicone resin comprising R 1 SiO 3/2 units and/or SiO 4/2 units in combination with R 1 3 SiO 1/2 units and/or R 1 2 SiO 2/2 units, wherein R 1 is independently a substituted or unsubstituted C 1 to C 10 hydrocarbyl group free of aliphatic unsaturation, an alkenyl group, or a hydrogen atom, with the proviso that said silicone resin (A) includes at least two silicon-bonded alkenyl groups or at least two silicon-bonded hydrogen atoms per molecule;
(B) an organosilicon compound having an average of at least two silicon-bonded hydrogen atoms or at least two silicon-bonded alkenyl groups per molecule, with the proviso that when said silicone resin (A) includes silicon-bonded alkenyl groups, said organosilicon compound (B) includes at least two silicon-bonded hydrogen atoms per molecule, and when said silicone resin (A) includes silicon-bonded hydrogen atoms, said organosilicon compound (B) includes at least two silicon-bonded alkenyl groups per molecule;
(C) a hydrosilylation catalyst;
(D) a flame retardant component comprising aluminum hydroxide in an amount to provide at least 15 parts by weight of said aluminum hydroxide in said composition based on 100 parts by weight of said composition; and
(E) a re

Assignees

• Dow Corning

Inventors

• Dent Stanton James
• Steinbrecher Jacob William
• Strong Michael Raymond

Classifications

• C08L83/04

  Polysiloxanes · CPC title

• C08G77/12

  containing silicon bound to hydrogen · CPC title

• C08K2201/014

  Additives containing two or more different additives of the same subgroup in C08K · CPC title

• C08L83/00

  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 title

• C08K2003/2241

  Titanium dioxide · CPC title