Crosslinkable materials based on organosilicon compounds
Moisture-curable organosilicon compositions which are storable in the absence of water, and crosslinkable on admission of water at room temperature to give elastomers, are based on organosilicon compositions containing: (A) compounds of the formula A-[(CR 1 2 ) b —SiR a (OR 2 ) 3-a ] x (I), (B) an organosilicon compound having basic nitrogen and (C) compounds of the formula R 3 —NH—C(═O)—C(═O)—NH—R 3 , and (II) optionally, further additives.
1. A non-yellowing moisture-curable crosslinkable composition which is storage stable in the absence of water, comprising:
(A) at least one compound of the formula
A-[(CR 1 2 ) b —SiR a (OR 2 ) 3-a ] x (I),
in which
A is an x-valent polyoxyalkylene radical bonded via —NR′—C(═O)—, —O—C(═O)—NH—, —C(═O)—O—, —O—C(═O)—O—, —O—, —O—CH 2 —C(OH)H—CH 2 —NR′—, —O—CH 2 —C(OH)H—CH 2 —S—, —O—CH 2 —C(OH)H—CH 2 —C(═O)— or —O—CH 2 —C(OH)H—CH 2 —O— to the group [(CR 1 2 ) b —SiR a (OR 2 ) 3-a ], in which R′ are identical or different and are hydrogen or a monovalent, optionally substituted hydrocarbon radical,
R each are identical or different monovalent, optionally substituted hydrocarbon radicals,
R 1 each are identical or different and are hydrogen or a monovalent, optionally substituted hydrocarbon radical optionally linked to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group,
R 2 each are identical or different and are hydrogen or a monovalent, optionally substituted hydrocarbon radical,
x is an integer from 1 to 10,
a is 0, 1 or 2 and
b is an integer from 1 to 10,
(B) one or more organosilicon compounds containing basic nitrogen and containing units of the formula
R k 12 D l Si(OR 13 ) m O (4-k-l-m)/2 (VI)
in which R 12 each are identical or different monovalent, optionally substituted SiC-bonded organic radicals free of basic nitrogen,
R 13 each are identical or different and are hydrogen or an optionally substituted hydrocarbon radical,
D are identical or different monovalent, Si-bonded radicals containing basic nitrogen,
k is 0, 1, 2 or 3,
l is 0, 1, 2, 3 or 4 and
m is 0, 1, 2 or 3,
with the proviso that the sum k+l+m is less than or equal to 4 and at least one radical D is present per molecule, and
(C) one or more oxaldianilides of the formula
R 3 —NH—C(═O)—C(═O)—NH—R 3 (II),
in which
R 3 each are identical or different monovalent, optionally substituted phenyl radicals.
2. The crosslinkable composition of claim 1 , wherein radicals A are polyoxyalkylene radicals bonded via —O—C(═O)—NH—, to the group [(CR 1 2 ) b —SiR a (OR 2 ) 3-a ], in which R′ are identical or different and are hydrogen or a monovalent, optionally substituted hydrocarbon radical.
3. The crosslinkable composition of claim 1 , wherein the radical A contains units of the formula
NR′—C(═O)— (V)
in which
R′ each are identical or different and are hydrogen or an optionally substituted, monovalent hydrocarbon radical, the units (V) bonded to the group [(CR 1 2 ) b —SiR a (OR 2 ) 3-a .
4. The crosslinkable composition of claim 1 , wherein component (B) is present in an amount of from 0.001 to 10 parts by weight, based on 100 parts by weight of component (A).
5. The crosslinkable composition of claim 1 , wherein radicals R 3 are phenyl, alkylphenyl, alkoxyphenyl or alkyl(alkoxy)phenyl radicals, the alkyl and alkoxy groups present in any position on the phenyl ring.
6. The crosslinkable composition of claim 1 , wherein component (C) is present in an amount of from 0.01 to 10 parts by weight, based on 100 parts by weight of component (A).
7. The crosslinkable composition of claim 1 , wherein the compositions comprise:
(A) compounds of the formula (I),
(B) organosilicon compounds containing basic nitrogen and containing units of the formula (VI),
R k 12 D l Si(OR 13 ) m O (4-k-l-m)/2 (VI)
in which
R 12 each are identical or different monovalent, optionally substituted SiC-bonded organic radicals free of basic nitrogen,
R 13 each are identical or different and are hydrogen or an optionally substituted hydrocarbon radical,
D are identical or different monovalent, Si-bonded radicals containing basic nitrogen,
k is 0, 1, 2 or 3,
l is 0, 1, 2, 3 or 4 and
m is 0, 1, 2 or 3,
with the proviso that the sum k+l+m is less than or equal to 4 and at least one radical D is present per molecule,
(C) oxaldianilides of the formula (II),
(D) crosslinking agents,
(E) optionally, plasticizers,
(F) optionally, fillers,
(G) optionally, adhesion promoters,
(H) optionally, organic solvents,
(K) optionally, catalysts and
(L) optionally, additives.
8. A molding produced by crosslinking the composition of claim 1 .