An epoxy ablative coating containing a silicone resin, a fibrous reinforcing material, and a non-alkali metal phosphate and borate salt mixture

Claim 2

The coated substrate of claim 1 in which said substrate is steel.

Claim 3

The coated substrate of claim 1 in which said substrate is plastic.

Claim 4

The coated substrate of claim 1 in which said ablative coating includes a small amount of powdered silica.

Claim 5

The coated substrate of claim 1 in which said silicone resin is a phenyl methyl polysiloxane.

Claim 6

The coated substrate of claim 1 in which said coating composition comprises approximately 20 to about 40 weight percent of epoxy resin, and about 2.5 to about 15 weight percent high purity silica fibers, about 1 to about 10 weight percent of said silicone resin and about 18 to about 25 percent by weight of said salt mixture based on the total weight of said composition.

Claim 7

The coated substrate of claim 7 in which said aromatic epoxy resin is a polyglycidyl ether of an aromatic diphenol.

Claim 8

A curable ablative coating composition comprising a mixture of at least approximately 20 weight percent of an epoxy resin selected from the group consisting of arOmatic epoxy resins and mixtures of aromatic and aliphatic epoxy resins, a non-elastomeric silicone resin, a polyamine or polyamide curing agent for said epoxy and silicone resins present in an effective curing amount, a reinforcing amount of high purity fibers having on the order of about 25 parts per million or less of alkali metal contamination, and from about 18 to about 25 percent by weight, based on the total weight of said composition, of a non-alkali metal salt mixture containing at least one non-alkali metal inorganic phosphate and at least one non-alkali metal inorganic borate.

Claim 9

The composition of claim 9 in which said epoxy resin comprises about 20 to about 40 weight percent of said composition, said silicone resin about 1 to about 10 weight percent, and said fibers from about 2.5 to about 15 weight percent.

Claim 10

The composition of claim 10 in which said salt mixture contains at least approximately 40 weight percent, based on the total weight of said mixture, of said inorganic borate.

Claim 11

The composition of claim 10 in which said curing agent is a polyamide and the total weight of said epoxy resin and curing agent is about 50 to about 75 weight percent of the total weight of said composition.

Claim 12

The composition of claim 10 in which said epoxy resin is a mixture of about 20 to about 30 weight percent, based on the weight of the total quantity of said epoxy resin, of an aromatic epoxy resin and an aliphatic epoxy resin comprising a polyglycoldiepoxide.

Claim 13

The composition of claim 10 in which said salt mixture comprises diammonium phosphate and ammonium tetraborate.

Claim 14

The composition of claim 14 in which said salt mixture is a 50-50 weight percent mixture of said phosphate and said borate.

Claim 15

The composition of claim 9 in which said salt mixture contains diammonium phosphate and ammonium tetraborate, and at least approximately 40 weight percent of the total weight of said mixture is said tetraborate.

Claim 16

The composition of claim 10 in which said curing agent is the reaction product of an organic polyamine and a long chain aliphatic fatty acid.

Claim 17

The composition of claim 10 in which said silicone resin is a methyl phenyl polysiloxane.

Claim 18

A curable ablative coating composition comprising, based on the total weight of said composition, a mixture of approximately 20 to about 40 weight percent of epoxy resin consisting essentially of about 20 to about 30 weight percent of an aliphatic epoxy resin and about 70 to about 80 weight percent of an aromatic epoxy resin, about 10 to 55 weight percent of a polyamine or polyamide curing agent, about 1 to about 10 weight percent of a methyl phenyl polysiloxane silicone laminating resin, about 2.5 to about 15 percent by weight of high purity silica fibers having on the order of about 25 parts per million or less of alkali metal contamination, and from about 18 to about 25 percent by weight of a non-alkal metal salt mixture containing at least one non-alkali metal inorganic phosphate and at least one non-alkali metal inorganic borate.

Claim 19

The composition of claim 19 in which said salt mixture comprises diammonium phosphate and ammonium tetraborate.

Claim 20

The composition of claim 20 in which a maximum of about 4 percent by weight of fumed silica is included, based on the total weight of the said composition.

Claim 21

The composition of claim 19 in which said aromatic epoxy resin is a polyglycidyl ether of an aromatic diphenol and said aliphatic epoxy resin is a polyglycoldiepoxide.

Claim 22

The composition of claim 19 in which said salt mixture contains at least approxiamtely 40 weight percent of said inorganic borate, based on the total weight of said mixture.

Claim 23

The composition of claim 20 in which said salt mixture is a 50-50 weight percent mixture of said diammonium phosphate and amMonium tetraborate.