Polyurea spray railcar lining systems
AssigneeHuntsman Petrochemical Corporation
InventorsDudley J. Primeaux, II, Kenneth C. Anglin
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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.
Claims17
A spray polyurea elastomer comprising a reaction product of:
- a quasi-prepolymer formed from
- 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 wherein the functional alkoxy silane is an adhesion promoter of formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing an epoxy group;
- n is an integer from 1 to 3, although it will be recognized the in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a straight chain alkyl group having 1 to 4 carbon atoms.
The elastomer of 1 where the active hydrogen-containing material is selected from the group consisting of a polyol, a polyoxyalkyleneamine or a combination thereof.
A spray polyurea elastomer prepared from:
- a quasi-prepolymer formed from
- an isocyanate comprising 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, wherein the functional alkoxy silane is an adhesion promoter of formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing an epoxy group;
- n is an integer from 1 to 3, although it will be recognized in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a straight chain alkyl group having 1 to 4 carbon atoms.
A spray polyurea elastomer comprising a composition formulated from:
- a quasi-prepolymer formed from
- an isocyanate comprising 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 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, wherein the functional alkoxy silane is an adhesion promoter of formula:
- R.sub.n Si(OR').sub.(4-n) (I)
- where:
- R is a hydrocarbon moiety containing an epoxy group;
- n is an integer from 1 to 3, although it will be recognized the in a mixture of functional alkoxy silanes n may average from 1 to 3;
- and
- R' is a straight chain alkyl group having 1 to 4 carbon atoms.
Dependencies are inferred from the claim text.