Isocyanate-based laminating adhesives
View Patent ↗The invention relates to a laminating adhesive including a reaction product of at least one polymeric polyol (part A) and at least one NCO terminated polyurethane prepolymer (part B). The part A includes a reaction product of at least one alkylene diol; at least one dial containing a pendant aliphatic chain; and at least one dicarboxylic acid. The part B includes a reaction product of at least one polyether polyol; and at least one polyisocyanate. The adhesive exhibits an initial viscosity of less than about 25,000 mPa.s at about 25° C.
1. A laminating adhesive comprising a reaction product of
A) at least one polymeric polyol (part A) comprising a condensation product of:
1) at least one alkylene diol;
2) at least one diol containing a pendant aliphatic chain; and
3) at least one dicarboxylic acid; with
B) at least one NCO-terminated polyurethane prepolymer (part B) comprising a reaction product of:
1) at least one polyether polyol; and
2) at least one polyisocyanate;
wherein said laminating adhesive exhibits an initial viscosity of less than about 25,000 mPa.s at 25° C.±5.0° C.
2. The laminating adhesive of claim 1 , wherein said part A exhibits an initial viscosity of less than about 25,000 mPa.s at 25° C.±5.0° C.
3. The laminating adhesive of claim 1 , wherein said part B exhibits an initial viscosity of less than about 25,000 mPa.s at 25° C.±5.0° C.
4. The laminating adhesive of claim 1 , wherein said at least one alkylene diol in part A has a hydroxyl number of from about 950 to about 1250.
5. The laminating adhesive of claim 1 , wherein said at least one pendant aliphatic chain containing diol in part A has a hydroxyl number of from about 950 to about 1250.
6. The laminating adhesive of claim 1 , wherein the equivalence ratio of hydroxyl component (part A) to isocyanate component (part B) is in a range of from about 1.0:1.0 to about 1.0:1.8.
7. The laminating adhesive of claim 1 , wherein said part B has residual isocyanate monomer of less than about 0.1% by weight, based on 100 parts total part B solids.
8. The laminating adhesive of claim 1 , wherein said at least one alkylene diol in part A is present in an amount of from about 5.0% by weight to about 25.0% by weight, based on 100 parts total part A solids.
9. The laminating adhesive of claim 1 , wherein said at least one pendant aliphatic chain containing diol in part A is present in an amount of from about 5.0% by weight to about 50.0% by weight, based on 100 parts total part A solids.
10. The laminating adhesive of claim 1 , wherein said at least one dicarboxylic acid in part A is present in an amount of from about 50.0% by weight to about 85.0% by weight, based on 100 parts total part A solids.
11. The laminating adhesive of claim 1 , wherein said part B has a percent isocyanate of from about 5.0% by weight to about 10.0% by weight, based on 100 parts total part B solids.
12. The laminating adhesive of claim 1 , wherein said at least one alkylene diol in part A is chosen from 1,4-butanediol, 1,6-hexnaediol, or mixtures thereof.
13. The laminating adhesive of claim 1 , wherein said at least one pendant aliphatic chain containing in part A is chosen from 2,2methyl-1,3-propanediol, meopentyl glycol, or mixtures thereof.
14. The laminating adhesive of claim 1 , wherein said at least one dicarboxylic acid in part A Is chosen from aliphatic polycarboxylic acids, cycloaliphatic polycarboxylic acids, aromatic polycarboxylic acid, or mixtures thereof.
15. The laminating adhesive of claim 14 , wherein said at least one dicarboxylic acid in part A is chosen from adipic acid, isophthalic acid, or mixtures thereof.
16. The laminating adhesive of claim 1 , wherein said at least one polyisocyanate is chosen from linear aliphatic polyisocyanates, branched aliphatic polyisocyantes, cyclic aliphatic polyisocyanates, aromatic polyisocyanates, or mixtures thereof.
17. The laminating adhesive of claim 16 , wherein said aromatic polyisocyanates comprises toluene diisocyanate.
18. A laminated article comprising at least two substrates bonded with the laminating adhesive of claim 1 .
19. The laminated article of claim 18 , wherein at least one of said substrates is chosen from paper, wood, metal, plastic, or synthetic polymers.