Process of forming a film of fluorine-containing resin on a metallic substrate

Claim 2

A process of forming a film of a fluorine-containing resin on a surface of a metallic substrate, comprising the steps of (a) coating the surface of the metallic substrate with said fluorine-containing resin, (b) placing the coated metallic substrate in a vacuum furnace, (c) developing in said vacuum furnace a partial vacuum of a predetermined degree within a range containing the order of 10 -3 Torr, (d) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 330° C. to about 420° C. for a predetermined period of time, (e) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a predetermined pre-quenching temperature lower than said predetermined heating temperature, (f) introducing an inert gas at ambient temperature into said furnace for quenching the coating on the substrate.

Claim 3

A process of forming a film of polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer on a surface of a metallic substrate, comprising the steps of (a) coating the surface of the metallic substrate with polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer, (b) placing the coated metallic substrate in a vacuum furnace, (c) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of from the order of 10 -3 Torr to the order of 10 -1 Torr, (d) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 330° C. to about 400° C. for a predetermined period of time, (e) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a predetermined pre-quenching temperature lower than said predetermined heating temperature, said predetermined prequenching temperature being within the range of from about 310° C. to about 360° C., (f) introducing an inert gas at ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 4

A process of forming a film of polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer on a surface of a metallic substrate, comprising the steps of (a) coating the surface of the metallic substrate with polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer, (b) placing the coated metallic substrate in a vacuum furnace, (c) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of from the order of 10 -3 Torr to the order of 10 -1 Torr, (d) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 330° C. to about 400° C. for a predetermined period of time, (e) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a predetermined pre-quenching temperature lower than said predetermined heating temperature, said predetermined prequenching temperature being within the range of from about 310° C. to about 360° C., (f) introducing an inert gas at ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 5

A process as set forth in claim 2, in which the vacuum in the furnace is maintained at said predetermined degree while the hot vacuumized atmosphere in the furnace is allowed to cool upon lapse of said predetermined period of time.

Claim 6

A process as set forth in claim 2, in which the vacuumized atmosphere in the furnace is maintained at said predetermined heating temperature for a predetermined period of time within the range of from about 40 minutes to about 60 minutes before the hot vacuumized atmosphere in the furnace is allowed to cool.

Claim 7

A process as set forth in claim 4, in which said polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer is applied in the form of particles to the surface of said metallic substrate.

Claim 8

A process as set forth in claim 4, in which said metallic substrate is constructed of a material selected from the group consisting of iron, aluminum, copper, ferroalloys, aluminum alloys and copper alloys.

Claim 9

A process as set forth in claim 4, further comprising the step of roughening the surface of said metallic substrate prior to the step of coating the surface with polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer.

Claim 10

A process as set forth in claim 7, further comprising the step of degreasing the surface of said metallic substrate prior to the step of roughening the surface of the substrate.

Claim 11

A process as set forth in claim 4, in which said metallic substrate is constructed of a material selected from aluminum and aluminum alloys, the process further comprising the step of anodizing the surface of said metallic substrate prior to the step of coating the surface of the metallic substrate with said fluorine-containing resin and after the step of roughening the surface of the substrate.

Claim 12

A process of forming a film of a fluorine-containing resin on a surface of an aluminum or aluminum-alloy substrate, said fluorine-containing resin being selected from the group consisting of polytetrafluoroethylen/polyhexafluoropropylene copolymer and polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer, the process comprising (a) roughening the surface of said substrate, (b) anodizing the roughened surface of the substrate (c) coating the anodized surface of the substrate with said fluorine-containing resin, (d) placing the coated substrate in a vacuum furnace, (e) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of from the order of 10 -3 Torr to the order of 10 -1 Torr, (f) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 330° C. to about 400° C. for a predetermined period of time, (g) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a predetermined pre-quenching temperature lower than said predetermined heating temperature, said predetermined prequenching temperature being within the range of from about 310° C. to about 360° C., (h) introducing an inert gas at ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 13

A process of forming a film of a fluorine-containing resin on a surface of an aluminum or aluminum-alloy substrate, said fluorine-containing resin being selected from the group consisting of polytetrafluoroethylen/polyhexafluoropropylene copolymer and polytetrafluoroethylene/perfluoropropyl vinyl ether copolymer, the process comprising (a) roughening the surface of said substrate, (b) anodizing the roughened surface of the substrate (c) coating the anodized surface of the substrate with said fluorine-containing resin, (d) placing the coated substrate in a vacuum furnace, (e) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of from the order of 10 -3 Torr to the order of 10 -1 Torr, (f) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 330° C. to about 400° C. for a predetermined period of time, (g) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a predetermined pre-quenching temperature lower than said predetermined heating temperature, said predetermined prequenching temperature being within the range of from about 310° C. to about 360° C., (h) introducing an inert gas at ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 14

A process as set forth in claim 10, in which the vacuum in the furnace is maintained at said predetermined degree while the hot vacuumized atmosphere in the furnace is being allowed to cool upon lapse of said predetermined period of time.

Claim 15

A process as set forth in claim 10, in which the vacuumized atmosphere in the furnace is maintained at said predetermined heating temperature for a predetermined period of time within the range of from about 40 minutes to about 60 minutes before the hot vacuumized atmosphere in the furnace is allowed to cool.

Claim 16

A process as set forth in claim 12, in which said fluorine-containing resin is applied in the form of particles to the surface of said substrate.

Claim 17

A process as set forth in claim 12, further comprising the step of degreasing the surface of said substrate prior to the step of roughening the surface of the substrate.

Claim 18

A process as set forth in claim 12, further comprising the step of treating the anodized surface of said substrate with hot water for sealing the porosities in the surface of the substrate prior to the step of coating the surface of the substrate with said fluorine-containing resin.

Claim 19

A process of forming a film of polytetrafluoroethylene on a surface of a metallic substrate, comprising the steps of (a) coating the surface of the metallic substrate with polytetrafluoroethylene, (b) placing the coated metallic substrate in a vacuum furnace, (c) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of the order of 10 -3 , (d) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 380° C. to about 420° C. for a predetermined period of time, (e) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a pre-quenching temperature lower by a predetermined value than said predetermined heating temperature, said predetermined pre-quenching temperature being within the range of from about 310° C. to about 360° C., said predetermined value being within the range of from about 40° C. to about 100° C., (f) introducing an inert gas of an ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 20

A process of forming a film of polytetrafluoroethylene on a surface of a metallic substrate, comprising the steps of (a) coating the surface of the metallic substrate with polytetrafluoroethylene, (b) placing the coated metallic substrate in a vacuum furnace, (c) developing in said vacuum furnace a partial vacuum of a predetermined degree within the range of the order of 10 -3 , (d) heating the vacuumized atmosphere in the furnace at a predetermined heating temperature of the range of from about 380° C. to about 420° C. for a predetermined period of time, (e) upon lapse of said predetermined period of time, allowing the hot vacuumized atmosphere in the furnace to cool spontaneously while maintaining a vacuum within said range in the furnace until the temperature in the furnace reaches a pre-quenching temperature lower by a predetermined value than said predetermined heating temperature, said predetermined pre-quenching temperature being within the range of from about 310° C. to about 360° C., said predetermined value being within the range of from about 40° C. to about 100° C., (f) introducing an inert gas of an ambient temperature into said vacuum furnace for quenching the coating on the substrate.

Claim 21

A process as set forth in claim 16, in which the vacuum in the furnace is maintained at said predetermined degree while the hot vacuumized atmosphere in the furnace is being allowed to cool upon lapse of said predetermined period of time.

Claim 22

A process as set forth in claim 16, in which the vacuumized atmosphere in the furnace is maintained at said predetermined heating temperature for about 30 minutes before the hot vacuumized atmosphere in the furnace is allowed to cool.

Claim 23

A process as set forth in claim 18, in which said polytetrafluoroethylene is applied in the form of a dispersed solution to the surface of said metallic substrate.

Claim 24

A process as set forth in claim 18, in which said metallic substrate is constructed of a material selected from the group consisting of iron, aluminum, copper, ferroalloys, aluminum alloys and copper alloys.

Claim 25

A process as set forth in claim 18, further comprising the step of roughening the surface of said metallic substrate prior to the step of coating the surface with polytetrafluoroethylene.

Claim 26

A process as set forth in claim 21, further comprising the step of degreasing the surface of said metallic substrate prior to the step of roughening the surface of the substrate.

Claim 27

A process as set forth in claim 18, in which said metallic substrate is constructed of a material selected from aluminum and aluminum alloys, the process further comprising the step of anodizing the surface of said metallic substrate prior to the step of coating the surface of the metallic substrate with said fluorine-containing resin and after the step of roughening the surface of the substrate.