Polysiloxane and method for producing same

Patent metadata

Field	Value
Publication number	US-11203668-B2
Application number	US-201816764132-A
Country	US
Kind code	B2
Filing date	Nov 13, 2018
Priority date	Nov 15, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

This polysiloxane: comprises a hydrolytic condensation product of a silicon compound that contains a cyclic alkoxysiloxane represented by formula (1)(in the formula, R1 groups each independently denote a substituted or unsubstituted alkyl group having 1-3 carbon atoms, R2 groups each independently denote a substituted or unsubstituted alkyl group having 1-6 carbon atoms, and n denotes an integer between 3 and 8); has at least two hydrosilylable carbon-carbon unsaturated groups per molecule; has at least two hydrosilyl groups per molecule; and in which the inequality 0.25≤t1<1 is satisfied, where t1 denotes the molar ratio of T units having a group represented by R1 relative to all siloxane units in the hydrolytic condensation product. The polysiloxane is addition crosslinkable, and is therefore suitable as a binder component of a heat-resistant paint or the like or as a coating material.

First claim

The invention claimed is:

1. A polysiloxane comprising a hydrolytic condensate of a silicon compound containing a cyclic alkoxysiloxane having the formula (1):

wherein R 1 is each independently a substituted or unsubstituted C 1 -C 3 alkyl group, R 2 is each independently a substituted or unsubstituted C 1 -C 6 alkyl group, and n is an integer of 3 to 8, the polysiloxane having at least two hydrosilylable carbon-carbon unsaturated groups per molecule and at least two hydrosilyl groups per molecule,
wherein provided that t1 is a molar fraction of T units having group R 1 relative to all siloxane units in the hydrolytic condensate, t1 is in the range: 0.25≤t1<1.

2. The polysiloxane of claim 1 which is a cohydrolytic condensate of the cyclic alkoxysiloxane having structural formula (1) and at least one compound selected from silicon compounds having the formulae (2) to (6):

wherein R 2 is as defined above, R 3 is hydrogen, a substituted or unsubstituted C 2 -C 6 alkenyl group, or C 6 -C 18 is aryl group, R 4 , R 5 , R 6 , R 7 and R 8 are each independently hydrogen or a substituted or unsubstituted C 1 -C 18 monovalent hydrocarbon group.

3. The polysiloxane of claim 2 wherein provided that q is a molar fraction of Q units, t2 is a molar fraction of T units having group R 3 , d is a molar fraction of D units, and m is a molar fraction of M units, q, t1, t2, d and m are in the range: 0≤q≤0.5, 0.25≤t1<1, 0≤t2≤0.5, 0≤d≤0.7, 0≤m≤0.5, and q+t1+t2+d+m=1.

4. The polysiloxane of claim 2 wherein R 1 is methyl, R 2 is each independently methyl or ethyl, R 3 is each independently hydrogen, vinyl or phenyl, R 4 , R 5 , R 6 , R 7 and R 8 are each independently hydrogen, methyl, vinyl or phenyl, and n is 4 or 5.

5. A heat curable composition comprising the polysiloxane of claim 1 and a platinum base catalyst,
the platinum base catalyst being present in such an amount as to give 0.01×10 −4 to 50×10 −4 part by weight of platinum per 100 parts by weight of the polysiloxane.

6. A cured product of the composition of claim 5 .

7. A method for preparing a polysiloxane comprising the step of effecting cohydrolytic condensation of a cyclic alkoxysiloxane having the formula (1) and at least one compound selected from silicon compounds having the formulae (2) to (6):

wherein R 1 is each independently a substituted or unsubstituted C 1 -C 3 alkyl group, R 2 is each independently a substituted or unsubstituted C 1 -C 6 alkyl group, R 3 is hydrogen, a substituted or unsubstituted C 2 -C 6 alkenyl group, or C 6 -C 18 is aryl group, R 4 , R 5 , R 6 , R 7 and R 8 are each independently hydrogen or a substituted or unsubstituted C 1 -C 18 is monovalent hydrocarbon group, and n is an integer of 3 to 8, with the proviso that at least two of R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are hydrogen, and at least two thereof are a substituted or unsubstituted C 2 -C 6 alkenyl group.

8. The method of claim 7 wherein R 1 is methyl, R 2 is each independently methyl or ethyl, R 3 is each independently hydrogen, vinyl or phenyl, R 4 , R 5 , R 6 , R 7 and R 8 are each independently hydrogen, methyl, vinyl or phenyl, and n is 4 or 5.

Assignees

• Shinetsu Chemical Co

Inventors

• Negishi Kazuyuki
• Yoshikawa Yuji

Classifications

• C08G77/06 Primary

  Preparatory processes · CPC title

• C08G77/20 Primary

  containing silicon bound to unsaturated aliphatic groups · CPC title

• C08G77/045

  containing less than 25 silicon atoms · CPC title

• C08G77/18 Primary

  to alkoxy or aryloxy groups · CPC title

• C08G77/70

  Siloxanes defined by use of the MDTQ nomenclature · CPC title