Foaming mixtures
Foamable compositions which are preferably isocyanate-free and which exhibit good foaming properties including short application times and freedom from cracks in the cured foam, are obtained from alkoxysilane-terminated prepolymers preferably containing polyurethane moieties, a blowing agent component, and a solvent having a boiling point in excess of 30° C.
1 - 11 . (canceled)
12 . A foamable composition comprising at least one isocyanate-free, alkoxysilane-terminated prepolymer, having silane end groups of the formula [2]
—SiR 3 z (OR 4 ) 3-z [2]
where
R 3 is an alkyl, cycloalkyl, alkenyl or aryl radical having 1-10 carbon atoms,
R 4 is an alkyl radical having 1-2 carbon atoms or an ω-oxaalkylalkyl radical having a total of 2-10 carbon atoms and
z is 0 or 1,
(B) at least one blowing agent, and
(C) at least one non-reactive solvent having a boiling point of at least 30° C.
13 . The composition of claim 12 , wherein at least one alkoxysilane-terminated prepolymer has silane end groups of the formula [3]
where
A 1 is an oxygen atom, an N—R 5 group or a sulfur atom, and
R 5 is a hydrogen atom, an alkyl, cycloalkyl, alkenyl or aryl radical having 1-10 carbon atoms or a —CH 2 —SiR 3 z (OR 4 )) 3-z group.
14 . The composition of claim 12 , which is isocyanate-free.
15 . The composition of claim 13 , which is isocyanate-free.
16 . The composition of claim 12 , wherein at least one blowing agent (B) is selected from the group consisting of hydrocarbons having 1-4 carbon atoms and dimethyl ether.
17 . The composition of claim 12 , wherein at least one solvent (C) has a boiling point of 40-200° C.
18 . The composition of claim 12 , wherein at least one solvent (C) is selected the group consisting of among ethers, esters and alcohols.
19 . The composition of claim 12 , wherein the solvent(s) (C) are added in a total concentration of 0.1-20% by volume, based on the weight of the prepolymer (A).
20 . The composition of claim 12 , wherein the prepolymers (A) comprise a polyurethane and are obtained by reacting polyols with diisocyanates or polyisocyanates, and with alkoxysilanes which bear either an isocyanate group or an isocyanate-reactive group.
21 . The composition of claim 20 , wherein the polyols comprise halogenated polyols all or in part.
22 . The composition of claim 12 , which further comprises at least one partially esterified phosphoric acid derivatives as a catalyst.
23 . A pressure vessel containing the foamable composition of claim 12 .
24 . A pressure vessel containing the foamable composition of claim 13 .
25 . A pressure vessel containing the foamable composition of claim 14 .
26 . A pressure vessel containing the foamable composition of claim 17 .
27 . A pressure vessel containing the foamable composition of claim 18 .
28 . A pressure vessel containing the foamable composition of claim 19.