Ablative composition
AssigneeFiber Materials, Inc.
InventorsLawrence E. McAllister, John E. Hill, Jr.
Life of this patent
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Abstract
In a coating composition for application to a substrate for curing thereon to form an ablative coating of the type including a reactive mixture of epoxy and polysulfide resins, an amine curing agent, and inorganic materials serving as a source of one or more Lewis acids and being capable of forming a glassy reaction product when exposed to heat, the improvement comprising adding carbonaceous pre-ox fibers thereto in a weight amount between about 15 to 40%. When applied to a substrate, the solvent-free composition cures to a tightly adhering, flexible coating capable of providing thermal protection in a very high temperature, erosive environment.
Claims8
In a coating composition suitable for application to a substrate for curing thereon to form an ablative coating, which composition includes a reactive resin mixture of an epoxy resin and a polysulfide resin in which said epoxy resin makes up at least 25% by weight of the total resin content, said reactive mixture being self-curing to provide a tough, adherent coating which forms a char when exposed to an ablative/erosion environment;
- an amine curing agent for curing said reactive mixture;
- and a mixture of finely divided inorganic materials providing a source of one or more Lewis acids and being capable of forming a glassy reaction product to stabilize said char;
- the improvement wherein
- said composition includes short pre-ox fibers which retain their fibrous structure during formation of said char.
In a combination of a substrate having adhered to the surface thereof an ablative coating characterized as being the polymeric reaction product of a polysulfide resin and an epoxy resin and having distributed therethrough a mixture of finely divided inorganic materials providing a source of one or more Lewis acids and being capable of forming a glassy product when said coating is exposed to a temperature in excess of about 2000 degrees F.;
- the improvement wherein said mixture includes carbonaceous pre-ox fibers;
- said inorganic materials being present in amount equivalent to between about 25% and about 40% by weight of said reaction product, and
- said fiber being present in amount equivalent to between about 15% and about 40% by weight of said reaction product.
In a method of protecting a substrate in an ablative/erosion environment, by
- (A) applying to the surface of a substrate a coating composition comprising (1) a reactive resin mixture of an epoxy resin and a polysulfide resin in which said epoxy resin makes up at least 25% by weight of the total resin content, (2) an amine curing agent for said reactive mixture, and (3) a mixture of finely divided inorganic materials providing a source of one or more Lewis acids and being capable of forming a glassy reaction product when exposed to said ablative/erosion environment, and
- (B) curing said reactive resin mixture under ambient conditions, the improvement including the step of
- mixing into said materials prior to the cure therof, carbonaneous pre-ox fibers in an amount between about 15% and 40% by weight of the total resin content.
Dependencies are inferred from the claim text.