Claims
- 1. An organosiloxane copolymer represented by the following general formula (4): ##STR18## wherein R.sup.4 is a monovalent hydrocarbon group; R.sup.5 and R.sup.6 are independently a monovalent hydrocarbon group or a halogenated alkyl group; A is a hydrogen atom or an organosilyl group represented by the following general formula:
- --Si(R.sup.7).sub.3
- wherein plural R.sup.7 are independently a hydrogen atom or a monovalent organic group, provided that at least one of plural R.sup.7 is a monovalent organic group; a is an integer of 4 or more; b is an integer of 2 or more; and c is an integer of 0 or more.
- 2. A process for producing the organosiloxane copolymer of claim 1, which comprises the steps of subjecting a cyclotrisiloxane represented by the following formula (5): ##STR19## to ringopening polymerization in the presence of a lithium compound represented by the following general formula (7):
- R.sup.4 (R.sup.8 R.sup.9 SiO).sub.n Li (7)
- wherein R.sup.4 is a monovalent hydrocarbon group, R.sup.8 and R.sup.9 are independently a monovalent hydrocarbon group or a halogenated alkyl group, and n is an integer of 0 or more, and adding to the resulting reaction mixture an acid or an organohalosilane represented by the following general formula (8):
- XSi(R.sup.7).sub.3 ( 8)
- wherein X is a halogen atom, and plural R.sup.7 are independently a hydrogen atom or a monovalent organic group, provided that at least one of plural R.sup.7 is a monovalent organic group, to stop the ringopening polymerization.
- 3. The process according to claim 2, wherein the cyclo trisiloxane of the formula (5) is subjected to the ringopening polymerization together with a cyclotrisiloxane represented by the following general formula (6) ##STR20## wherein R.sup.5 and R.sup.6 are independently a monovalent hydrocarbon group or a halogenated alkyl group.
Priority Claims (2)
Number |
Date |
Country |
Kind |
7-199012 |
Jul 1995 |
JPX |
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7-201505 |
Jul 1995 |
JPX |
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Parent Case Info
This is a Division of application Ser. No. 08/678,755 filed on Jul. 11, 1996 U.S. Pat. No. 5,693,735.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5449800 |
Shimada et al. |
Sep 1995 |
|
5475076 |
Braun et al. |
Dec 1995 |
|
5496961 |
Dauth et al. |
Mar 1996 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
678755 |
Jul 1996 |
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