Hydrophobized cement-containing compositions
View Patent ↗The present invention relates to cement-containing compositions which are characterized in that they have a proportion of organosilicon compounds of greater than 0.15% by weight, based on the proportion of cement, the organosilicon compounds being based on at least one organosilicon compound selected from the group consisting of the alkoxysilanes and at least one selected from the group consisting of the alkoxysiloxanes, to a process for the preparation thereof and to the use thereof.
1. A cement-containing composition comprising a proportion of organosilicon compounds of from 0.25 to 1% by weight, based on the proportion of cement, said organosilicon compounds are based on at least one organosilicon compound selected from the group consisting of alkoxysilanes and at least one selected from the group consisting of alkoxysiloxanes.
2. The composition according to claim 1 , wherein said organosilicon compounds are based on
a) 5 to 95% by weight of alkoxysilanes of general formula (I)
R 1 —Si—(OR 2 ) 3 (I)
in which
R 1 is an alkyl radical having 1 to 16 carbon atoms, and
R 2 is an alkyl radical having 1 to 4 carbon atoms, and
b) 95 to 5% by weight of alkoxysiloxanes of general formula (II)
in which
R 3 is an alkyl radical having 1 to 6 carbon atoms,
R 4 is an alkyl radical having 1 to 4 carbon atoms,
a is 0.8 to 1.2, and
b is 0.2 to 1.2.
3. The composition according to claim 1 wherein said organosilicon compounds are based on
c) 5 to 95% by weight of alkoxysilanes of general formula (I)
R 1 —Si—(OR 2 ) 3 (I)
in which
R 1 is an alkyl radical having 1 to 16 carbon atoms, and
R 2 is an alkyl radical having 1 to 4 carbon atoms, and
d) 95 to 5% by weight of a mixture consisting of
d1) a silane of general formula (III)
R 6 —Si—(OR 5 ) 3 (III)
in which
R 5 is an alkyl radical having 1 to 4 carbon atoms,
R 6 denotes an aminoalkyl radical having 1 to 6 carbon atoms,
a radical of general formula (IV),
H 2 N—(CH 2 ) x R 7 —(CH 2 ) y− (IV),
in which
R 7 denotes a —O—, —S—, —NH— or —NH—CH 2 —CH 2 —NH— radical,
x is greater than or equal to 2, and
y is greater than or equal to 2, or is a radical of general formula (V)
(R 8 O) 3 Si—(CH 2 ) z —NH—(CH 2 ) z — (V),
in which
R 8 denotes an alkyl radical having 1 to 4 carbon atoms, and
z is greater than or equal to 2,
and n denotes an integer from 1 to 5, and
d2) a polysiloxane of general formula (VIII)
HO—[Si(R 9 ) 2 O] m —H (VIII)
in which
R 9 is identical or different and is a methyl or phenyl radical, but at least 90% of the radicals R 9 are methyl radicals and m is 20 to 250, the ratio of d1) to d2) being kept so that an SiOH group of the compound d2) corresponds to >1 to 3 OR 5 groups of the compound d1).
4. The composition according to claim 3 , wherein
R 1 is an alkyl radical having 3 to 8 carbon atoms,
R 2 is a methyl or ethyl radical,
R 5 is an H 2 N—(CH 2 ) 3 — or an H 2 N—(CH 2 ) 3 —NH—(CH 2 )— radical or a radical of formula
and
R 9 is exclusively a methyl radical, and
m has a value from 30 to 80.
5. The composition according to claim 3 , wherein up to 50% by weight of the component d) are replaced by equal amounts of a siloxane of formula
where R′=alkyl radical having 1 to 8 carbon atoms or a phenyl radical, R″=an alkyl radical having 1 to 4 carbon atoms, a=0.8 to 1.2 and b=0.2 to 1.2.
6. The composition according to claim 1 , wherein said organosilicon compounds are at least one compound selected from the group consisting of the alkoxysilanes and at least one compound selected from the group consisting of the alkoxysiloxanes.
7. The composition according to claim 6 , wherein the reaction is carried out at a temperature of 150° C. to 200° C.
8. The composition according to claim 1 , wherein said composition is in the form of concrete or an artificial stone.
9. Structures or parts thereof which contain a composition according to claim 1 .
10. A process for the preparation of a hardened cement-containing composition comprising:
adding an aqueous emulsion to a cement-containing, flowable mixture, wherein said aqueous emulsion includes organosilicon compounds which are based on at least one compound selected from the group consisting of alkoxysilanes and at least one compound selected from the group consisting of alkoxysiloxanes, and said aqueous emulsion is added in an amount such that the proportion of the organosilicon compounds in the cement-containing, flowable composition is from 0.25 to 1% by weight, based on the proportion of cement; and
hardening the mixture.
11. The process according to claim 10 , wherein the aqueous emulsion is added has a proportion of 1 to 75% by weight of organosilicon compounds, based on the emulsion.
12. The process according to claim 10 , wherein more than 2% by weight of aqueous emulsion is added to the mixture.
13. The process according to claim 10 , wherein said emulsion is used which has 1 to 10% by mass of one or more emulsifiers selected from anionic, cationic and nonionogenic emulsifiers or mixtures.
14. The process according claim 10 , wherein said organosilicon compounds are based on
a) 5 to 95% by weight of alkoxysilanes of general formula (I)
R 1 —Si—(OR 2 ) 3 (I)
in which
R 1 is an alkyl radical having 1 to 16 carbon atoms, and
R 2 is an alkyl radical having 1 to 4 carbon atoms, and
b) 95 to 5% by weight of alkoxysiloxanes of general formula (II)
in which
R 3 is an alkyl radical having 1 to 6 carbon atoms,
R 4 is an alkyl radical having 1 to 4 carbon atoms,
a is 0.8 to 1.2, and
b is 0.2 to 1.2.
15. The process according to claim 10 wherein said organosilicon compounds are based on
c) 5 to 95% by weight of alkoxysilanes of general formula (I)
R 1 —Si—(OR 2 ) 3 (I)
in which
R 1 is an alkyl radical having 1 to 16 carbon atoms and
R 2 is an alkyl radical having 1 to 4 carbon atoms, and
d) 95 to 5% by weight of a mixture consisting of
d1) a silane of the general formula (III)
R 6 —Si—(OR 5 ) 3 (III)
in which
R 5 is an alkyl radical having 1 to 4 carbon atoms,
R 6 denotes an aminoalkyl radical having 1 to 6 carbon atoms,
a radical of general formula (IV)
H 2 N—(CH 2 ) x R 7 —(CH 2 ) y− (IV),
in which
R 7 denotes a —O—, —S—, —NH— or —NH—CH 2 —CH 2 —NH— radical,
x is greater than or equal to 2, and
y is greater than or equal to 2, or is a radical of general formula (V),
(R 8 O) 3 Si—(CH 2 ) z —NH—(CH 2 ) z — (V),
in which R 8 denotes an alkyl radical having 1 to 4 carbon atoms, and
z is greater than or equal to 2,
and n denotes an integer from 1 to 5, and
d2) a polysiloxane of general formula (VIII)
HO—[Si(R 9 ) 2 O] m —H (VIII)
in which
R 9 is identical or different and is a methyl or phenyl radical, but at least 90% of the radicals R 9 are methyl radicals and m is 20 to 250, the ratio of d1) to d2) being kept so that an SiOH group of the compound d2) corresponds to >1 to 3 OR 5 groups of the compound d1).
16. The process according to claim 15 , wherein
R 1 is an alkyl radical having 3 to 8 carbon atoms,
R 2 is a methyl or ethyl radical,
R 5 is an H 2 N—(CH 2 ) 3 — or an H 2 N—(CH 2 ) 3 —NH—(CH 2 )— radical or a radical of formula
and
R 9 is exclusively a methyl radical and
m has a value from 30 to 80.
17. The process according to claim 15 , wherein up to 50% by weight of the component d) are replaced by equal amounts of a siloxane of formula
where R′=alkyl radical having 1 to 8 carbon atoms or a phenyl radical, R″=an alkyl radical having 1 to 4 carbon atoms, a=0.8 to 1.2 and b=0.2 to 1.2.
18. The process according to claim 10 , wherein said organosilicon compounds are obtained by reacting at least one compound selected from the group consisting of the alkoxysilanes and at least one compound selected from the group consisting of the alkoxysiloxanes.
19. The process according to claim 18 , wherein the reaction is carried out at a temperature of 150° C. to 200° C.