US3956166A
Expired / Lapsed
US
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Antistructure agent
Assignee: Wacker Chemical Corp
•
Filing: 1975-05-02
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Granted: 1976-05-11
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Expires: 1995-05-02
Abstract
Abstract An antistructure agent consisting essentially of hexamethyltrisiloxanediol and methoxyhexamethyltrisiloxanol is prepared by reacting hexamethylcyclotrisiloxane with water, methanol and a short-chain fatty acid. It is very effective in preventing structure buildup in silicone elastomers.
Inventors
- 👤 Richard Newton Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:11
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/045; C08L; C08L83/00; C08L83/04; C08G77/14; C08G77/16; C08G77/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
43 words
An antistructure agent comprising a mixture of hexamethyltrisiloxane-1,5-diol and 1-methoxy-hexamethyltrisiloxane-5-ol, in which the hydroxyl content is between 5 and 11 percent, the methoxy content is between 2 and 4 percent, and the mole ratio of hydroxyl to methoxy is between 2.5 and 7.
Claim 2
Dependent Claim
43 words
An antistructure agent comprising a mixture of hexamethyltrisiloxane-1,5-diol and 1-methoxy-hexamethyltrisiloxane-5-ol, in which the hydroxyl content is between 5 and 11 percent, the methoxy content is between 2 and 4 percent, and the mole ratio of hydroxyl to methoxy is between 2.5 and 7.
Claim 3
Dependent Claim
36 words
The antistructure agent of claim 1 contains minor amounts of linear dimethylsiloxanes having from 4 to 6 silicon atoms and having methoxy and hydroxyl end groups, and cyclic dimethylsiloxanes having from 3 to 6 silicon atoms.
Claim 4
Dependent Claim
58 words
A method for producing the antistructure agent of claim 1 which comprises heating a mixture of hexamethylcyclotrisiloxane, water and methanol, in which the mole ratio of water to hexamethylcyclotrisiloxane is between 0.5 and 2.0 and the number of moles of methanol is between 3 and 10 times the greater of the number of moles of water or hexamethylcyclotrisiloxane.
Claim 5
Dependent Claim
19 words
The method of claim 3 in which the mole ratio of methanol to water to hexamethylcyclotrisiloxane is approximately 5:1:1.
Claim 6
Dependent Claim
37 words
The method of claim 3 in which the reaction is conducted at a pH between 2 and 5 in the presence of a water-soluble organic acid catalyst having a pK a value of between 1.5 and 6.
Claim 7
Dependent Claim
12 words
The method of claim 5 in which the catalyst is formic acid.
Claim 8
Dependent Claim
12 words
The method of claim 5 in which the catalyst is acetic acid.
Claim 9
Dependent Claim
12 words
The method of claim 5 in which the catalyst is maleic acid.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |