Dielectric materials

Claim 2

A process for making a dielectric material comprising: (a) treating fluorocarbon fibers to render them wettable by an uncured thermosetting resin, the fibers being held under longitudinal tension during such treatment, thereby preventing longitudinal shrinkage of said fibers during treatment to produce treated fluorocarbon fibers, (b) weaving a fabric containing at least a portion of said treated fluorocarbon fibers, (c) impregnating said fabric with an uncured thermosetting resin, and (d) heating and drying said resin-impregnated-fabric to cure said resin to at least the semi-cured, B-stage state.

Claim 3

A process for making a dielectric material comprising: (a) treating a fabric containing at least a portion of fluorocarbon fibers to render said fluorocarbon fibers wettable by an uncured thermosetting resin, (b) impregnating said fabric with an uncured thermosetting resin, and (c) heating and drying said resin-impregnated-fabric to cure said resin to at least the semi-cured, B-stage state.

Claim 4

A process for making a dielectric material comprising: (a) treating a fabric containing at least a portion of fluorocarbon fibers to render said fluorocarbon fibers wettable by an uncured thermosetting resin, (b) impregnating said fabric with an uncured thermosetting resin, and (c) heating and drying said resin-impregnated-fabric to cure said resin to at least the semi-cured, B-stage state.

Claim 5

The process of claims 1 or 2 including the step of calendering said fabric to reduce its thickness.

Claim 6

The process of claims 1 or 2 in which said treating includes applying an alkali naphthanate solution to said fluorocarbon fibers or fabric.

Claim 7

The process of claim 4 including napping the fluorocarbon fibers to improve wettability and adhesion between said fibers and resin.

Claim 8

The process of claims 1 or 2 wherein said fibers or fabric are bleached subsequent to treating them to make them wettable.

Claim 9

The process of claim 6 wherein an oxidizing agent is used to bleach the fibers or fabric.

Claim 10

The process of claim 7 wherein the fibers or fabric are bleached by heating to a temperature in the range of about 500° F. to about 675° F.

Claim 11

The process of claim 2 wherein said fabric is held in longitudinal and transverse tension during said treatment, thereby preventing shrinkage of said fabric in the longitudinal and transverse directions during treatment.

Claim 12

The process of claim 2 wherein said fabric is unrestrained during said treatment and is allowed to shrink, following which the fabric is stretched to approximately its original dimensions prior to said treatment.

Claim 13

The process of claim 1 including laminating an electrically conductive foil to at least one side of said resin-impregnated-fabric.

Claim 14

The process of claim 2 including laminating an electrically conductive foil to at least one side of said resin-impregnated-fabric.

Claim 15

The process of claim 1 or 2 including laminating one or more sheets of said resin-impregnated-fabric in which the thermosetting resin is cured to the fully-cured, C-stage state, and one or more sheets of said resin-impregnated-fabric in which the thermosetting resin is cured to the semi-cured, B-stage state, wherein, wherever a layer of material in said C-stage state contacts another layer, said other layer is of material in said B-stage state.

Claim 16

The process of claim 1 or 2 including laminating one or more sheets of said resin-impregnated-fabric in which the thermosetting resin is cured to the fully-cured, C-stage state, and having an electrically conductive foil bonded to at least one side of at least one of said sheets, and one or more sheets of said resin-impregnated-fabric in which the thermosetting resin is cured to the semi-cured, B-stage state, wherein, wherever a layer of material in said C-stage state, and wherein, wherever an electrically conductive foil contacts another layer, said other layer is of material in said B-stage state.

Claim 17

The process of claim 1 or 2 including curing the thermosetting resin in the dielectric material to the fully-cured, C-stage state.

Claim 18

The process of claim 1 or 2 including laminating at least one additional layer of a composite structure other than said resin-impregnated-fabric to said resin-impregnated-fabric.

Claim 19

The process of claim 16 wherein said at least one additional layer is a layer selected from the group consisting of epoxy/fiberglass, fluorocarbon/fiberglass, polyimide/fiberglass, epoxy/polyaramide fiber, epoxy/quartz fiber and polyimide/quartz fiber composites.

Claim 20

The process of claim 1 or 2 wherein said thermosetting resin is selected from one group consisting of epoxy, polyimide, polyamide, polyester, phenolic and acrylic thermosetting resin.