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US3957683A
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Paste-like mixtures containing a cross-linking agent and a condensation catalyst
Assignee: Wacker Chemie AG
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Filing: 1974-03-18
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Granted: 1976-05-18
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Expires: 1994-03-18
Abstract
Abstract The invention relates to paste-like mixtures that are used in the preparation of room temperature vulcanizable compositions comprising a cross-linking agent, a condensation catalyst and a hydrophobic silicon dioxide thickening agent which is solid at room temperature.
Inventors
- 👤 Paul Hittmair
- 👤 Wolfgang Hechtl
- 👤 Ernst Wohlfarth
- 👤 Richard Schmidlkofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:47
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/04; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
136 words
An improved paste-like composition which is to be mixed with an organopolysiloxane composition to form a room temperature curable composition, said paste-like composition consisting essentially of a mixture of a cross-linking agent and a condensation catalyst capable of curing the organopolysiloxane composition said condensation catalyst being present in an amount of 1 part by weight for each 1 to 10 parts by weight of the cross-linking agent, the improvement which comprises adding to the mixture a hydrophobic silicon dioxide thickening agent which is a solid at room temperature and has a surface area of at least 50m 2 /g, said hydrophobic silicon dioxide is present in an amount of one part by weight for each 1 to 10 parts by weight based on the total weight of the mixture containing the cross-linking agent and condensation catalyst.
Claim 2
Dependent Claim
136 words
An improved paste-like composition which is to be mixed with an organopolysiloxane composition to form a room temperature curable composition, said paste-like composition consisting essentially of a mixture of a cross-linking agent and a condensation catalyst capable of curing the organopolysiloxane composition said condensation catalyst being present in an amount of 1 part by weight for each 1 to 10 parts by weight of the cross-linking agent, the improvement which comprises adding to the mixture a hydrophobic silicon dioxide thickening agent which is a solid at room temperature and has a surface area of at least 50m 2 /g, said hydrophobic silicon dioxide is present in an amount of one part by weight for each 1 to 10 parts by weight based on the total weight of the mixture containing the cross-linking agent and condensation catalyst.
Claim 3
Dependent Claim
135 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with a compound selected from the group consisting of (R 3 Si) a Z and R b SiZ' 4-b to impart hydrophobic properties thereto, wherein R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals having up to 18 carbon atoms, Z is selected from the group consisting of halogen, hydrogen, --OH, --OR', --NR'X, --ONR' 2 , --SR', --OOCR', --O--, --N(X)-- and --S--, Z' is selected from the group consisting of halogen, hydrogen, --OH, --OR', --NR'X, --ONR' 2 , --SR', and --OOCR', R' is an alkyl radical having from 1 to 4 carbon atoms, X is selected from the group consisting of hydrogen and R' and a and b are each equal to 1 or 2.
Claim 4
Dependent Claim
20 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with trimethylethoxysilane to impart hydrophobic properties thereto.
Claim 5
Dependent Claim
72 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with a silane of the formula R c Si(OR') 4-c to impart hydrophobic properties thereto, wherein R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals having up to 18 carbon atoms, R' is an alkyl radical having from 1 to 4 carbon atoms and c is a number of 1 to 3.
Claim 6
Dependent Claim
70 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with a silane of the formula R 3 SiN(X)SiR 3 where R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals having up to 18 carbon atoms, X is selected from the group consisting of hydrogen and R', where R' is an alkyl radical having from 1 to 4 carbon atoms.
Claim 7
Dependent Claim
12 words
The improved paste-like composition of claim 5 wherein the silane is hexamethyldisilazane.
Claim 8
Dependent Claim
20 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with hexamethyldisiloxane to impart hydrophobic properties thereto.
Claim 9
Dependent Claim
35 words
The improved paste-like composition of claim 1 wherein the silicon dioxide is reacted with a dimethylpolysiloxane having terminal Si-bonded hydroxyl groups and from 2 to 12 siloxane units per molecule to impart hydrophobic properties thereto.
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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) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |