Heat stable reaction injection molded elastomers
AssigneeTexaco Development Corporation
InventorsRichard J. G. Dominguez, Doris M. Rice
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Abstract
The invention is a method for making reaction injection molded polyurethane of improved properties. The product comprises the cured reaction product of a high molecular weight polyhydric polyether, a low molecular weight active hydrogen containing compound of at least two functionality and a polyisocyanate. The reaction product is cured by subjecting it to an ambient temperature of from about 290.degree.-425.degree. F. for a time sufficient to achieve an improvement in properties. The invention is also the resulting polyurethane.
Claims12
A method of making a foamed polyurethane elastomer of improved properties which comprises injecting via a RIM machine into a mold cavity of the desired configuration a foam formulation, demolding the molded article and post curing the demolded article at a temperature from about 290.degree. F. to 425.degree. F. for a time sufficient to achieve an improvement in properties said formulation being the reaction product of an aromatic polyisocyanate, a polyol of above about 500 equivalent weight and a chain-extending agent comprising a low molecular weight active hydrogen containing component of at least two (2) functionality wherein the polyisocyanate and chain-extender are chosen from products which yield an isocyanate chain-extender reaction product with a glass transition temperature of above about 325.degree. F. and wherein the polyol is chosen from those products which do not significantly adversely affect the glass transition temperature of the isocyanate chain-extender reaction product.
In a method for making a polyurethane elastomer of improved properties wherein a polyol of above about 500 equivalent weight, an aromatic polyisocyanate and a chain-extending agent comprising a low molecular weight active hydrogen containing compound of at least two (2) functionality is injected into a mold cavity of the desired configuration wherein the polyisocyanate and chain-extender are chosen from products which yield an isocyanate chain-extender reaction product with a glass transition temperature of above about 325.degree. F. and wherein the polyol is chosen from those products which do not significantly adversely affect the glass transition temperature of the isocyanate chain-extender reaction product wherein a molded article is formed the improvement which comprises
- post curing the molded article at a temperature of about 290.degree. F. to 425.degree. F. for a time sufficient to achieve an improvement in properties.
In a method for making a polyurethane elastomer of improved properties wherein a polyol of above about 500 equivalent weight, an aromatic polyisocyanate and a chain-extending agent comprising a low molecular weight active hydrogen containing compound of at least two (2) functionality is injected into a mold cavity of the desired configuration wherein the polyisocyanate and chain-extender are chosen from products which yield an isocyanate chain-extender reaction product with a glass transition temperature of above about 325.degree. F. and wherein the polyol is chosen from those products which do not significantly adversely affect the glass transition temperature of the isocyanate chain-extender reaction product wherein a molded article is formed the improvement which comprises
- post curing the molded article at a temperature of about 310.degree. F. for a time sufficient to achieve an improvement in properties.
A method of making a foamed polyurethane elastomer of improved properties which comprises injecting via a RIM machine into a mold cavity of the desired configuration a foam formulation, demolding the molded article and post curing the demolded article at a temperature from about 310.degree. F. to 350.degree. F. for a time sufficient to achieve an improvement in properties said formulation being the reaction product of an aromatic polyisocyanate, a polyol of above about 500 equivalent weight and a chain-extending agent comprising a low molecular weight active hydrogen containing component of at least two (2) functionality wherein the polyisocyanate and chain-extender are chosen from products which yield an isocyanate chain-extender reaction product with a glass transition temperature of above about 325.degree. F. and wherein the polyol is chosen from those products which do not significantly adversely affect the glass transition temperature of the isocyanate chain-extender reaction product.
Dependencies are inferred from the claim text.