Thermally conductive polyorganosiloxane composition

Patent metadata

Field	Value
Publication number	US-11142644-B2
Application number	US-201816481086-A
Country	US
Kind code	B2
Filing date	Jan 25, 2018
Priority date	Jan 27, 2017
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

The present invention relates to a thermally conductive polysiloxane composition that provides a cured product having excellent tackiness and flexibility in which the composition contains (A) a thermally conductive filler, (B) a siloxane compound having an alkoxysilyl group and a linear siloxane structure, (C) a polyorganosiloxane having at least two alkenyl groups bonded to silicon atoms per molecule, (D1) a linear polyorganohydrogensiloxane represented by the general formula (4), (D2) a polyorganohydrogensiloxane having per molecule at least three units represented by the general formula (5), and (E) a platinum catalyst.

First claim

The invention claimed is:

1. A thermally conductive polysiloxane composition comprising:
(A) a thermally conductive filler;
(B) a siloxane compound having an alkoxysilyl group and a linear siloxane structure;
(C) a polyorganosiloxane having at least two alkenyl groups bonded to silicon atoms per molecule;
(D1) a linear polyorganohydrogensiloxane represented by the following general formula (4):

wherein:
R 7 is a hydrogen atom,
R 8 is each independently a monovalent hydrocarbon group having no aliphatic unsaturated bond and having 1 to 12 carbon atoms, and
f is 1 to 200;

(D2) a polyorganohydrogensiloxane having per molecule at least three units represented by the following general formula (5):
R 9 g R 10 h SiO ({4−(g+h)}/2)   (5)

wherein:
R 9 is each independently a monovalent hydrocarbon group having no aliphatic unsaturated bond and having 1 to 12 carbon atoms,
R 10 is a hydrogen atom,
g is an integer of 0 to 2,
h is an integer of 1 or 2, and
g+h is an integer of 1 to 3, with the proviso that a case in which g is 1 and h is 1 is excluded; and

(E) a platinum catalyst,
wherein (D2) is a polyorganohydrogensiloxane comprising a R 11 2 HSiO 1/2 unit, wherein R 11 is synonymous with R 9 , and a SiO 4/2 unit, and having at least three hydrogen atoms bonded to silicon atoms per molecule,
wherein a ratio ((H D1 +H D2 )/Vi C ) of a sum (H D1 +H D2 ) of a number H D1 of hydrogen atoms bonded to silicon atoms of (D1) and a number H D2 of hydrogen atoms bonded to silicon atoms of (D2) to a number Vi C of the alkenyl groups of (C) is 0.85 or less, and
wherein a ratio of H D1 :H D2 is in a range of from 9:1 to 8:2.

2. The thermally conductive polysiloxane composition according to claim 1 , wherein (B) is a siloxane compound represented by the following general formula (1):

wherein:
R 1 is a group having an alkoxysilyl group having 1 to 4 carbon atoms,
R 2 is a linear organosiloxy group represented by the following general formula (2):

wherein:
R 4 is each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms,
Y is a group selected from the group consisting of a methyl group, a vinyl group, and R 1 , and
d is an integer of 2 to 500;

X is each independently a divalent hydrocarbon group having 2 to 10 carbon atoms,
a and b are each independently an integer of 1 or more,
c is an integer of 0 or more,
a+b+c is an integer of 4 or more, and
R 3 is each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms or a hydrogen atom.

3. The thermally conductive polysiloxane composition according to claim 1 , wherein (C) is a linear polyorganosiloxane represented by the following general formula (3):

wherein:
R 5 is each independently an alkenyl group having 2 to 6 carbon atoms,
R 6 is each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and
e is a number such that the viscosity of 0.01 to 50 Pa·s at 23° C.

Assignees

• Momentive Performance Mat Jp

Inventors

• Hirakawa Daigo
• Takanashi Masanori
• Sakamoto Atsushi

Classifications

• H10W40/251

  Organics · CPC title

• C08K3/36

  Silica · CPC title

• C08L83/04 Primary

  Polysiloxanes · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08K2003/2227

  of aluminium · CPC title