The invention relates to novel prepolymers which are accessible from the formamides of oligomeric di- or polyamines (formamide-terminated oligomers) and di- or polyisocyanates.
1. A prepolymer of diisocyanates and formamide-terminated oligomers, wherein said prepolymer is of formula (I)
X—[—N(CHO)—CO—NH—R 1 —NCO] n (I)
wherein
R 1 is a C6-C13-arylalkyl radical or a C4-C13-alkylene radical;
n is a natural number from 2 to 4;
X is an n-valent organic radical.
2. The prepolymer of claim 1 , wherein X is a radical of formula (II)
Y—[—(CH 2 —CHR 3 —(CH 2 ) p —O) m —CH 2 —CHR 4 —(CH 2 ) o —] n — (II)
wherein
Y is an n-functional saturated C2-C6 radical;
R 3 is hydrogen or methyl;
R 4 represents hydrogen or methyl;
m is a natural number from 2 to 30;
n is a natural number from 2 to 4;
o is 0 or 1; and
p is 0, 1, or 2.
3. The prepolymer of claim 2 , wherein,
R 4 is methyl;
o is 0; and
p is 0.
4. A process for preparing the prepolymer of claim 1 , comprising reacting a diisocyanate with a formamide-terminated oligomer and separating any excess of said diisocyanate off by distillation.
5. A process for preparing the prepolymer of claim 2 , comprising reacting
n to (n×10) moles of a diisocyanate of formula (III)
OCN—R 1 —NCO (III),
wherein
R 1 is a C6-C13-arylalkyl radical or a C4-C13-alkylene radical; and
n is a natural number from 2 to 4;
with one mole of formamide-terminated oligomer of formula (IV)
X—[—NH(CHO)] n (IV),
wherein
X is a radical of formula (II)
Y—[—(CH 2 —CHR 3 —(CH 2 ) p —O) m —CH 2 —CHR 4 —(CH 2 ) o —] n — (II)
wherein
Y is an n-functional saturated C2-C6 radical;
R 3 is hydrogen or methyl;
R 4 represents hydrogen or methyl;
m is a natural number from 2 to 30;
n is a natural number from 2 to 4;
o is 0 or 1; and
p is 0, 1, or 2; and
n is a natural number from 2 to 4;
and separating any excess of said diisocyanate off by distillation.
6. A PU shaped or foamed article comprising the prepolymer of claim 1 .
7. An adhesive comprising the prepolymer of claim 1 .
8. A sealant comprising the prepolymer of claim 1 .
9. A lacquer comprising the prepolymers of claim 1 .
10. A PU shaped or foamed article comprising the prepolymer of claim 2 .
11. An adhesive comprising the prepolymer of claim 2 .
12. A sealant comprising the prepolymer of claim 2 .
13. A lacquer comprising the prepolymers of claim 2 .