Thin walled polynitrile oxide crosslinked rubber film products and methods of manufacture thereof
View Patent ↗Natural rubber and/or synthetic polyisoprene film products having enhanced tear strength and tensile strength crosslinked with a one polynitrile oxide, intended for direct or indirect contact with living tissue or fluids to be placed in living organisms.
1. A thin walled, dip-molded or cast rubber film product of a natural rubber or synthetic cis-1,4-polyisoprene rubber compound crosslinked with a polynitrile oxide crosslinking agent, said product having a tear strength of from about 15 kN/m to about 60 kN/m, and a tensile strength of from about 1700 psi to about 6000 psi.
2. The thin walled rubber film product of claim 1 , having the crosslinked structure of formula (I);
wherein,
A represents an aryl group substituted by a bulky group in at least one ortho position to the isoxazoline rings,
the aromatic structure having a ratio of hydrogen atoms to carbon atoms of less than 1:1 and,
the bulky group being substantially unreactive with a nitrile oxide functionality;
R 1 represents the natural rubber or cis-1,4-polyisoprene rubber polymer chain;
R 2 and R 3 are independently selected from hydrogen and methyl wherein;
when R 2 is methyl, R 3 is hydrogen and,
when R 3 is methyl, R 2 is hydrogen.
3. The thin walled rubber film product of claim 2 , wherein the crosslinked chemical formula comprises:
4. The thin walled rubber film product of claim 1 , free of any sulfur-containing accelerators and free of any nitrosatable substances.
5. The thin walled rubber film product of claim 1 , wherein the product is a surgical or examination glove, a catheter balloon, a condom or a dental dam.
6. The thin walled rubber film product of claim 1 , prepared by compounding the rubber, forming the product and curing the rubber while reducing or eliminating pre-vulcanization of the rubber compound.
7. A thin walled, dip-molded or cast natural rubber or synthetic cis-1,4-polyisoprene rubber film product prepared by:
(a) compounding a natural rubber or synthetic cis-1,4-polyisoprene rubber so as to substantially reduce or prevent pre-vulcanization of the resulting rubber compound;
(b) dip-molding or casting the rubber compound to form the thin-walled rubber film product;
(c) admixing the rubber compound or thin walled film product with at least one polynitrile oxide crosslinking agent; and
(d) curing the rubber compound to produce crosslinking therein;
the film product having a tear strength of from about 15 kN/m to about 60 kN/m, and a tensile strength of from about 1700 psi to about 6000 psi.
8. The thin walled rubber film product of claim 7 , substantially free of any sulfur-containing accelerators and free of any nitrosatable substances.
9. The thin walled rubber film product of claim 7 , wherein the product is a surgical or examination glove, a catheter balloon, a condom or a dental dam.