Unvulcanized expanded high green strength synthetic rubber product and method of manufacture

Claim 2

A process for producing a unvulcanized expanded foamed or sponge-like rubber product which at room temperature has properties that are competitive with vulcanized styrene-butadiene foamed or sponge-like products having similar levels of fillers and extenders comprising compounding into a synthetic rubber having a green tensile strength in excess of 2500 psi the desired amounts of fillers and extenders along with a sufficient amount of blowing agent to effect the desired degree of expansion, activating the blowing agent by heating, effecting a desired expansion of the mass and then quenching the mass to rapidly cool the same sufficiently to arrest the action of the blowing agent.

Claim 3

A process according to claim 1 wherein the compounded mass of rubber and blowing agent is calendered into sheet-like form, the blowing agent is activated by heating, and then when a desired expansion of the mass has been obtained the mass is quickly quenched.

Claim 4

A process according to claim 2 wherein the sheet-like form is placed upon a screen and there heated and allowed to drape and to expand desirably following which it is quenched.

Claim 5

A process according to claim 1 wherein the high green tensile strength rubber is a radial block copolymer derived from butadiene/styrene.

Claim 6

A process according to claim 1 wherein the quenching is effected with a spray of water.

Claim 7

A product produced by the process of claim 1.

Claim 8

A product produced by the process of claim 2.

Claim 9

A product produced by the process of claim 3.

Claim 10

A product produced by the process of claim 4.

Claim 11

A product produced by the process of claim 5.

Claim 12

The product of claim 6 wherein the high green strength rubber is a styrene-butadiene ABA-type block copolymer and the product consists essentially of the following ingredients in about the following proportions: Ingredients Parts by weight ______________________________________ Block copolymer 150 CACO.sub.3 filler 100-400 Naphthenic extender oil Half that of the filler Antioxidant 1 Hydrocarbon resin 15 Blowing agent 8. ______________________________________

Claim 13

The product of claim 11 wherein the block copolymer has a butadiene to styrene ratio of from about 80/20 to about 60/40 and from about 10 to about 40 percent of the styrene is in terminal blocks.

Claim 14

The product of claim 12 wherein the CACO 3 filler is present in the amount of about 200 parts by weight.

Claim 15

The product of claim 11 wherein the block copolymer is a radial block copolymer.

Claim 16

The product of claim 13 wherein the block copolymer is a radial block copolymer.

Claim 17

A product according to claim 7 wherein the synthetic rubber is a block copolymer.

Claim 18

A product according to claim 8 wherein the synthetic rubber is a radial block copolymer.

Claim 19

A foamed synthetic rubber composition in which essentially all of the rubber is an unvulcanized synthetic rubber which has a green strength in its unfoamed state in excess of 2500 psi (ASTM Method D412-61T).

Claim 20

A foamed synthetic rubber composition in which essentially all of the rubber is an unvulcanized synthetic rubber which has a green strength in its unfoamed state in excess of 2500 psi (ASTM Method D412-61T).

Claim 21

A product according to claim 18 wherein the foamed synthetic rubber is a foamed block copolymer.

Claim 22

A product according to claim 19 wherein the foamed synthetic rubber is foamed ABA-type block copolymer.

Claim 23

A product according to claim 20 wherein the foamed synthetic rubber is a sheet having a textured surface or protuberances on at least one surface.

Claim 24

A sponge-like rubber sheet having a textured surface or protuberances on at least one surface prepared according to the process of claim 3.