Method for crosslinking polyolefins with in situ generated water
Compositions comprising a polymer resin comprising at least one copolymer with hydrolysable groups, an amino acid or diearboxylic acid water-generating organic compound, and a catalyst that comprises a metal atom and at least two ligands taken from the set alkyloxy and earhcxylate are used to form articles that moisture-cure through in-situ generation of water via ring-closing dehydration reactions.
1. A composition comprising:
(A) A polymer resin comprising at least one copolymer with hydrolysable groups,
(B) An amino acid or amic acid water-generating organic compound, and
(C) A catalyst that comprises a metal atom and two or more ligands selected from the group consisting of alkyloxy and carboxylate and combinations thereof.
2. The composition of claim 1 wherein the hydrolysable groups are silane functional groups.
3. The composition of claim 1 wherein the copolymer is the polymerization product of a vinyltrialkoxysilane and at least one other monomer.
4. The composition of claim 3 wherein the other monomer is selected from the group consisting of styrene, ethylene, propylene, methyl methacrylate, vinyl acetate and combinations thereof.
5. The composition of claim 3 wherein vinyltrialkoxysilane is present in an amount between about 0.1 and about 5 mole % relative to all monomers.
6. The composition of claim 1 wherein the copolymer is a copolymer of ethylene and vinyltrimethoxysilane.
7. The composition of claim 1 wherein the water-generating organic compound is at least one of an amino acid of Formula (1) or an amic acid of Formula (2):
H 2 N—R 1 —COOH (1)
HOOC—R 1 —C(O)NH 2 (2)
wherein R 1 is a hydrocarbon diradical with at least two carbon atoms positioned between the two end substituents.
8. The composition of claim 7 wherein the amino acid is γ-aminobutyric acid.
9. The composition of claim 7 wherein the auric acid is phthalamic acid.
10. The composition of claim 1 wherein the catalyst is a dibutyltin dilaurate or a distannoxane.
11. The composition of claim 1 wherein the catalyst is dibutyltin dilaurate.
12. The composition of claim 1 wherein the water-generating organic compound is present in an amount sufficient to provide between about 0.1 and about 4 moles of water per mole of hydrolysable groups.
13. The composition of claim 1 wherein the catalyst is present in an amount between about 0.1 and about 20 mole % based on the moles of hydrolysable groups.
14. An article comprising the composition of claim 1 and at least one selected from the group consisting of flame retardants, fillers, antioxidants, phosphites, UV stabilizers, cling additives, light stabilizers, thermal stabilizers, mold release agents, tackifiers, waxes, processing aids, crosslinking agents, colorants and pigments.
15. The article of claim 14 wherein the article is a foam, film, fiber, footwear, pipe, cable, or wire.
16. A process for forming a moisture-cured article, the process comprising forming the composition of claim 1 into an article and allowing the composition to cure.
17. The process of claim 16 wherein the cure is done at a temperature below the melting point of the copolymer.
18. The process of claim 16 wherein the cure is conducted at ambient temperatures.