High voltage flame retardant EPOM insulating compositions

Claim 2

An ethylene propylene diene terpolymer composition suitable for use as an insulator in high voltage electrical connector applications, said composition comprising an ethylene propylene diene terpolymer, reinforcement fillers, a curing agent and a synergistic mixture of fire retardant agents and flow improvers comprising at least (1) a brominated organic flame retardant, (2) a hydrated alumina flame retardant, (3) an antimony oxide synergist, and (4) a flow improver, which synergistic mixture increases the flow of the composition during molding, increases internal lubrication, and provides better release and non-sticking characteristics, said composition being characterized by good flame retardancy, tensile strength, elongation and Shore "A" Hardness with good flow during molding.

Claim 3

A composition according to claim 1 which contains a reinforcing filler and a semi-reinforcing filler in said composition.

Claim 4

A composition according to claim 2 wherein said composition contains about 1.4 to 3 parts of the brominated organic flame retardant per part of antimony oxide synergist.

Claim 5

A composition according to claim 3 wherein the curing agent comprises an organic peroxide.

Claim 6

A composition according to claim 4 wherein said ethylene propylene diene terpolymer is a polymer formed by reaction of 40-90 mol percent ethylene, 40-10 mole percent propylene, and 3-10 mol percent of a diene.

Claim 7

A composition according to claim 2 wherein said composition contains a reinforcing filler comprising an anhydrous aluminum silicate in pigment form and a semi-reinforcing filler comprising a precipitated amorphous silica.

Claim 8

A composition according to claim 3, wherein said brominated organic flame retardant is decabromodiphenyl-oxide.

Claim 9

A composition according to claim 7 wherein said hydrated alumina flame retardant is a tri-hydrate of alumina.

Claim 10

A composition according to claim 1 wherein said flow improver is a mixture of internal lubricants, external lubricants, mold release agents and surfactants.

Claim 11

A composition according to claim 8 wherein said composition also contains a polymer grade zinc borate as a flame retardant for killing after glow.

Claim 12

A composition according to claim 10 wherein said composition also contains a plasticizer to provide low temperature flexibility.

Claim 13

A composition according to claim 11 wherein the composition contains a high activity anti-oxidant.

Claim 14

A composition according to claim 12 wherein said composition contains zinc oxide in fine particle size and high purity as an activator and stabilizer.

Claim 15

A composition according to claim 13 wherein said composition contains an alkaline earth metal salt of a fatty acid as a lubricant and mold release.

Claim 16

A composition according to claim 13 wherein said composition contains red lead oxide as a coloring agent and for imparting electrical qualities.

Claim 17

A composition according to claim 14 wherein said curing agent comprises an organic peroxide in combination with a synergist comprising trimethylolpropanetrimethacrylate.

Claim 18

A composition according to claim 1 which contains the following amounts of essential ingredients: ______________________________________ Component Amounts - Parts by wt. ______________________________________ EPDM Polymer 100 Fillers 65-110 Flame Retardants 40-120 Flow Improvers 5-15 Curing Agents 7-20 ______________________________________

Claim 19

A composition according to claim 1 which contains the following components and amounts: ______________________________________ Component Amounts - Parts by wt. ______________________________________ EPDM Polymer 100 Silica Filler 25-42 Aluminum Silicate Filler 40-75 Brominated Organic Flame 20-50 Retardant Aluminum Hydrate Flame 15-40 Retardant Antimony Oxide Flame Retar- 10-30 dant Paraffinic Oil Plasticizer 5-20 Zinc Borate Flame Retardant 10-25 Coloring Agent 1-10 Antioxidant 0.1-2 Zinc Oxide Activator 2-12 and Stabilizer Flow Improver 5-15 Curing Agent 5-10 Synergist for Curing Agent 2-10 Silane Coupling Agent 0.1-2 Calcium Stearate Processing 0.5-5 Aid ______________________________________

Claim 20

A composition according to claim 17 which contains the following components and amounts: ______________________________________ Component Amounts - Parts by wt. ______________________________________ EPDM Polymer 100 Amorphous Silica Filler 30 Aluminum Silicate Filler 60 Paraffinic Oil Plasticizer 10 Brominated Organic Flame 35 Retardant Aluminum Hydrate Flame 25 Retardant Antimony Oxide Flame 20 Retardant Zinc Borate Flame Retardant 17.5 Flow Improver 12.5 Antioxidant 0.5 Coloring Agent 5 Zinc Oxide Activator and 4 Stabilizer Peroxide Curing Agent 7 Synergist for Curing Agent 5 Silane Coupling Agent 1 Calcium Stearate Processing 2 Aid ______________________________________

Claim 21

An insulator comprising the composition of claim 1.

Claim 22

An insulator for use in high voltage electrical systems comprising the composition of claim 17.

Claim 23

An insulator according to claim 21 produced by molding the composition of claim 1 by compression molding, transfer molding, injection molding, insert molding, or extrusion.

Claim 24

An insulator according to claim 22 wherein said molding is conducted at a temperature in the range of 300°-390° F. with residence time of 2-4 minutes.

Claim 25

An insulator for use in high voltage electrical systems comprising the molded composition of claim 19.