Organo(poly)siloxane compositions which can be cross-linked to give elastomers with elimination of alcohols
AssigneeWacker Chemie AG
InventorsRudolf Braun, Petra Absmaier
Life of this patent
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Abstract
The invention relates to organo(poly)siloxane compositions which have long shelf life in the absence of water, but can be crosslinked in the presence of water, even at room temperature, to give elastomers with elimination of alcohols, and to a process for the preparation of such compositions.
Claims10
An organo(poly)siloxane composition which can be cross-linked to give elastomers with elimination of alcohols comprising (A) .alpha.,.omega.-dihydroxyorgano(poly)siloxane,
- (B) an organosilicon compound of the general formula ##STR33## where R is a monovalent, optionally substituted hydrocarbon radical or an --SiR.sup.2.sub.3 radical,
- R.sup.1 is a hydrogen atom, a monovalent organic radical or an organosiloxy group,
- R.sup.2 is a hydrogen atom or a monovalent organic radical,
- R.sup.3 is a divalent, optionally substituted organic radical,
- a is 0 or an integer between 1 and 1,000,
- b is 0 or an integer between 1 and 100,
- c is 0 or an integer between 1 and 100,
- x is 0 or an integer between 1 and 100, and
- y is 1, 2 or 3,
- with the proviso that each organosilicon compound molecule of formula (I) contains an average of more than two organyloxy radicals RO--, where R is a monovalent, optionally substituted hydrocarbon radical, and optionally (C) an organosilicon compound of the general formula ##STR34## where R.sup.4 is a monovalent, optionally substituted hydrocarbon radical or an --SiR.sup.2.sub.3 radical,
- R.sup.2 is a hydrogen atom or a monovalent organic radical,
- R.sup.5 is a hydrogen atom, a monovalent organic radical or an organosiloxy group,
- R.sup.6 is a divalent, optionally substituted organic radical,
- R.sup.7 is a monovalent, SiC-bonded, optionally substituted hydrocarbon radical having 1 to 18 carbon atom(s),
- d is 0 or an integer between 1 and 1,000,
- e is 0 or an integer between 1 and 100,
- f is 0 or an integer between 1 and 100,
- v is 0 or an integer between 1 and 100, and
- w is 1 or 2,
- with the proviso that each organosilicon molecule of formula (II) contains an average of more than one organyloxy radical R.sup.4 O--, where R.sup.4 is a monovalent, optionally substituted hydrocarbon radical and in the case where x=0 or a+b+c=0, at least one additional substance selected from the group consisting of fillers, plasticisers and adhesion promoters is present.
A process for the preparation of organo(poly)siloxane compositions which can be cross-linked to form elastomers by the elimination of alcohols, which comprises mixing in a first step at a temperature of from 15.degree. to 80.degree. C. and at a pressure of from 900 to 1,100 hPa for from 5 to 90 minutes, the following ingredients;
- (A) .alpha.,.omega.-dihydroxyorgano(poly)siloxane,
- (B) an organosilicon compound of the general formula ##STR43## where R is a monovalent, optionally substituted hydrocarbon radical or an --SiR.sup.2.sub.3 radical,
- R.sup.1 is a hydrogen atom, a monovalent organic radical or an organosiloxy group,
- R.sup.2 is a hydrogen atom or a monovalent organic radical,
- R.sup.3 is a divalent, optionally substituted organic radical,
- a is 0 or an integer between 1 and 1,000,
- b is 0 or an integer between 1 and 100,
- c is 0 or an integer between 1 and 100,
- x is 0 or an integer between 1 and 100, and
- y is 1, 2 or 3,
- with the proviso that each organosilicon compound molecule of formula (I) contains an average of more than two organyloxy radicals RO--, where R is a monovalent, optionally substituted hydrocarbon radical, and optionally additives and subsequently, in a second step, continuing to stir the ingredients at a pressure of from 0.01 to 100 hPa for from 3 to 60 minutes, in which the stirring speed is selected so that the temperature of the composition during stirring increases to a value within the temperature range of from 15.degree. C. to 80.degree. C. without further heating.
An organosilicon compound of the formula ##STR46## where R.sup.4 is a monovalent, optionally substituted hydrocarbon radical or an --SiR.sup.2.sub.3 radical,
- R.sup.2 is a hydrogen atom or a monovalent organic radical,
- R.sup.6 is a divalent, optionally substituted organic radical,
- R.sup.7 is a monovalent organic radical,
- e is 0 or an integer between 1 and 100,
- f is 0 or an integer between 1 and 100,
- v is an integer between 1 and 100, and
- w is 1 or 2,
- with the proviso that each organosilicon compound molecule contains an average of more than one organyloxy radical R.sup.4 O--, where R.sup.4 is a monovalent optionally substituted hydrocarbon radical, and e and f are each on average greater than 0.
An organosilicon compound of the formula ##STR47## in which R.sup.3 is a divalent, optionally substituted organic radical,
- b is 0 or an integer between 1 and 100,
- c is 0 or an integer between 1 and 100,
- x is an integer between 1 and 100,
- y is 1, 2 or 3,
- R is a monovalent, optionally substituted hydrocarbon radical or an --SiR.sup.2.sub.3 radical,
- R.sup.2 is a hydrogen atom or a monovalent organic radical, with the proviso that each organosilicon compound molecule contains an average of more than two organyloxy radicals RO--, where R is a monovalent, optionally substituted hydrocarbon radical, and b and c are each an average greater than 0.
Dependencies are inferred from the claim text.