Polyurea spray railcar lining systems
AssigneeHuntman Petrochemical Corporation
InventorsDudley J. Primeaux, II, Kenneth C. Anglin
Life of this patent
Estimating the term…
Abstract
Spray polyurea elastomer systems have improved adhesion to a substrate with the incorporation of a functional alkoxy silane and water. Such systems typically also include a quasi-prepolymer of an isocyanate and an active hydrogen-containing material, and at least one amine resin, and preferably an amine-terminated chain extender. The system may also benefit from the incorporation of a higher than usual proportion of 2,4'-isomer methylene diisocyanate (MDI). The viscosity of the various components, as well as various processing characteristics, may be improved by the addition of an alkylene carbonate. The spray polyurea elastomer systems of this invention also have improved abrasion and impact resistance.
Claims19
A spray polyurea elastomer comprising:
- a quasi-prepolymer of
- an isocyanate, and
- an active hydrogen-containing material;
- at least one amine resin;
- at least one amine-terminated chain extender;
- water;
- and
- a functional alkoxy silane as an adhesion promoter, which functional alkoxy silane has the formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing epoxy;
- n is an integer from 1 to 3, although it will be recognized that in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a lower, straight chain alkyl group having 1 to 4 carbon atoms.
The spray polyurea elastomer of claim I where the functional alkoxy silane is an epoxy alkoxy silane where R' is methyl or ethyl.
A spray polyurea elastomer comprising:
- a quasi-prepolymer of
- an isocyanate, which isocyanate comprises methylene diisocyanate, and at least 30% of the methylene diisocyanate is the 2,4'-isomer thereof, and
- an active hydrogen-containing material;
- at least one amine resin;
- at least one amine-terminated chain extender;
- water;
- and
- from about 0.1 pbw to about 0.5 pbw, based on the total spray polyurea elastomer, of at least one functional alkoxy silane as an adhesion promoter, which functional alkoxy silane has the formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing epoxy;
- n is an integer from 1 to 3, although it will be recognized that in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a lower, straight chain alkyl group having 1 to 4 carbon atoms.
A spray polyurea elastomer comprising:
- a quasi-prepolymer of
- an isocyanate, which isocyanate comprises methylene diisocyanate, and at least 30% of the methylene diisocyanate is the 2,4'-isomer thereof, and
- an active hydrogen-containing material;
- at least one amine resin;
- at least one amine-terminated chain extender;
- an alkylene carbonate, where the alkylene carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, and dimethyl carbonate;
- water;
- and
- from about 0.1 pbw to about 0.5 pbw, based on the total spray polyurea elastomer, of at least one functional alkoxy silane as an adhesion promoter, which functional alkoxy silane has the formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing epoxy;
- n is an integer from 1 to 3, although it will be recognized that in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a lower, straight chain alkyl group having 1 to 4 carbon atoms
- where the at least one functional alkoxy silane is mixed with the at least one amine resin prior to addition of the quasi-prepolymer thereto.
Dependencies are inferred from the claim text.