Foams containing silicon
Both flexible and rigid foams may be prepared by reacting di- or polyisocyanates with organopolysiloxanes which are prepared by reaction of silanol-terminated organopolysiloxanes with organosilicon compounds containing alkyleneoxy or alkylenamino groups bonded on both ends to silicon, thus resulting in organopolysiloxanes having 95% or more of aminoalkyl or hydroxyalkyl terminal groups.
1 - 13 . (canceled)
14 . A foamable composition comprising
(A) at least one linear or branched organopolysiloxane (A) in which at least 95% of the chain ends are terminated by aminoalkyl or hydroxyalkyl groups of the general formula (1)
—O—SiR 1 2 O—SiR 2 2 —R 3 -Z (1),
prepared by reacting linear or branched organopolysiloxanes having end groups of the formula (2)
—O—SiR 1 2 —OH (2),
with organosilicon compounds composed of structural elements of the formula (3),
—[SiR 2 2 —R 3 —Y—] k (3)
where
R 1 and R 2 are each a monovalent, unsubstituted or —CN or halogen-substituted C 1 -C 12 -hydrocarbon radical in which one or more nonadjacent methylene units can be replaced by —O— units,
R 3 is a divalent, unsubstituted or cyano- or halogen-substituted C 1 -C 12 -hydrocarbon radical,
Z is an OH or NH 2 group,
Y is an oxygen atom or an NR 4 radical,
R 4 is a hydrogen atom or a radical of the formula (3) in which k is 1 and Y is an NH 2 group, and
k is an integer from 1 to 1,000,
(B) at least one diisocyanate or polyisocyanate, and
(C) one or more blowing agents.
15 . The foamable composition of claim 14 , wherein at least 99% of the chain ends of the organopolysiloxane (A) are terminated by aminoalkyl or hydroxyalkyl groups of the general formula (1).
16 . The foamable composition of claim 14 , in which both aminoalkyl groups and hydroxyalkyl groups of the formula (1) are present in the same molecule of organopolysiloxane (A).
17 . The foamable composition of claim 14 , wherein the degree of polymerization n of the polyorganosiloxane (A) chain is from 5 to 100.
18 . The foamable composition of claim 14 , wherein the organosilicon compounds composed of structural elements of the general formula (3) are selected from the group consisting of the formulae 6 and 7,
where
k is an integer of at least 2.
19 . The foamable composition of claim 14 which contain at least one catalyst (D) which promotes the reaction between an isocyanate group and an aminoalkyl and/or hydroxyalkyl group, said catalyst (D) selected from the group consisting of organotin compounds, organic iron compounds, organic titanates, and tertiary amines.
20 . A 2-Component foamable composition of claim 14 , comprising
an isocyanate-terminated organopolysiloxane-polyurethane prepolymer which is a reaction product of at least one organopolysiloxane (A) and a stoichiometric excess of one or more diisocyanates or polyisocyanates (B) in a first component and
water as a blowing agent (C) in a second component.
21 . A 1-Component foamable composition of claim 14 , comprising at least one isocyanate-terminated prepolymer which is a reaction product of at least one organopolysiloxane (A) and a stoichiometric excess of one or more diisocyanates or polyisocyanates (B), at least one physical blowing agent (CP), and at least one catalyst (D).
22 . A multicomponent foamable composition of claim 14 , comprising at least a first component comprising a silicone prepolymer (PS) whose chain ends are selected from among aminoalkyl and hydroxyalkyl groups of the formula (1) and water, and at least a second component comprising at least one diisocyanate or polyisocyanate (B).
23 . The multicomponent foamable compositions of claim 22 , comprising an organopolysiloxane (A) as a silicone prepolymer (PS) in the first component.
24 . The multicomponent foamable composition of claim 22 , comprising siloxane prepolymers (PSB) prepared by reaction of organopolysiloxanes (A) with a stoichiometric deficiency of diisocyanates or polyisocyanates (B) as a silicone prepolymer (PS) in the first component.
25 . A foam prepared by curing the composition of claim 1
26 . A foam prepared by curing a 1-component composition of claim 21 .
27 . A foam prepared by curing a multi-component composition of claim 22 .
28 . A foam prepared by curing a multi-component composition of claim 24 .
29 . A polyurethane, polyurea, or polyurethaneurea foam comprising the foamed reaction product of at least one di- or polyisocyanate or mixture thereof with an isocyanate-reactive organopolysiloxane having the formula (1) described in claim 14 .
30 . The foam of claim 29 , wherein said organopolysiloxane having the formula (1) has at least 97% of chain ends terminated by aminoalkyl groups, hydroxyalkyl groups, or mixtures thereof.
31 . The foam of claim 29 wherein said organopolysiloxane having the formula (1) has no residual silanol groups detectable by 1 H-NMR and 29 Si-NMR.