Surgical bandage

Claim 2

A bandage comprising a pressure sensitive adhesive layer, a layer of semi-open cell flexible polymeric foam attached to said adhesive layer, and a water-impervious flexible polymeric film attached to the opposite side of said foam layer wherein said adhesive layer comprises a rubbery elastomer having dispersed therein a water soluble or swellable hydrocolloid or mixture of hydrocolloids, tackifier, and plasticizer.

Claim 3

The bandage of claim 1 wherein said hydrocolloid is selected from the group consisting of polyvinyl alcohol, powdered pectin, gelatin, sodium carboxymethylcellulose, high molecular weight carbowax, carboxypolymethylene, and mixtures thereof.

Claim 4

The bandage of claim 2 wherein said hydrocolloid or hydrocolloid mixture comprises more than about 30% by weight of the adhesive layer.

Claim 5

The bandage of claim 3 wherein said hydrocolloid or hydrocolloid mixture comprises from about 40 to about 50% by weight of the adhesive layer.

Claim 6

The bandage of claim 1 wherein said rubbery elastomer is selected from the group consisting of natural rubber, silicone rubber, acrylonitrile rubber, polyurethane rubber, and polyisobutylene.

Claim 7

The bandage of claim 1 wherein said semi-open cell flexible polymeric foam has from about 50 to about 100 cells per linear inch with from about 30 to about 70% of the cells ruptured.

Claim 8

The bandage of claim 1 wherein said adhesive layer is from about 5 to about 30 mils in thickness, said foam layer is from about 20 to about 50 mils in thickness, and said water-impervious film is from about 1.0 to about 3.0 mils in thickness.

Claim 9

The bandage of claim 1 including a layer of release paper attached to the exposed bottom of said adhesive layer.

Claim 10

A bandage comprising a pressure sensitive adhesive layer, a layer of semi-open cell flexible polymeric foam attached to said adhesive layer having from about 50 to about 100 cells per linear inch with from about 30 to about 70% of the cells ruptured, and a water-impervious flexible polymeric film attached to the opposite side of said foam layer wherein said adhesive layer comprises a rubbery elastomer having dispersed therein a water soluble or swellable hydrocolloid or mixture of hydrocolloids, a tackifier, and a plasticizer, and wherein said hydrocolloid comprises more than about 30% by weight of the adhesive layer and is selected from the group consisting of polyvinyl alcohol, powdered pectin, gelatin sodium carboxymethylcellulose, high molecular weight carbowax, carboxypolymethylene, and mixtures thereof and said elastomer is selected from the group consisting of natural rubber, silicone rubber, acrylonitrile rubber, polyurethane rubber, and polyisobutylene.

Claim 11

A bandage comprising a pressure sensitive adhesive layer, a layer of semi-open cell flexible polymeric foam attached to said adhesive layer having from about 50 to about 100 cells per linear inch with from about 30 to about 70% of the cells ruptured, and a water-impervious flexible polymeric film attached to the opposite side of said foam layer wherein said adhesive layer comprises a rubbery elastomer having dispersed therein a water soluble or swellable hydrocolloid or mixture of hydrocolloids, a tackifier, and a plasticizer, and wherein said hydrocolloid comprises more than about 30% by weight of the adhesive layer and is selected from the group consisting of polyvinyl alcohol, powdered pectin, gelatin sodium carboxymethylcellulose, high molecular weight carbowax, carboxypolymethylene, and mixtures thereof and said elastomer is selected from the group consisting of natural rubber, silicone rubber, acrylonitrile rubber, polyurethane rubber, and polyisobutylene.

Claim 12

The bandage of claim 9 wherein said pressure sensitive adhesive layer contains from about 40 to about 50% by weight of the hydrocolloid or hydrocolloid mixture and also contains an antioxidant.

Claim 13

The bandage of claim 10 wherein said pressure sensitive adhesive layer is from about 5 to 30 mils in thickness, said foam layer is from about 20 to about 50 mils in thickness, and said water-impervious film is from about 1.0 to about 3.0 mils in thickness.

Claim 14

The bandage of claim 11 wherein said elastomer is polyisobutylene and said hydrocolloid is a mixture of sodium carboxymethylcellulose and gelatin.

Claim 15

The bandage of claim 12 wherein said flexible polymeric foam is flexible polyurethane foam and said water-impervious flexible polymeric film is flexible polyurethane.

Claim 16

The bandage of claim 13 wherein said pressure sensitive adhesive layer consists of a polyisobutylene having an average molecular weight of from 81,000 to 99,000, polyisobutylene having an average molecular weight of 10,000 to 11,700, sodium carboxymethylcellulose, gelatin, terpene resin, mineral oil, and butylated hydroxytoluene.

Claim 17

The bandage of claim 14 wherein said adhesive layer is of from about 5 to about 15 mils in thickness, said flexible polyurethane film is of from about 1.5 to about 2 mils in thickness, and said flexible polyurethane foam contains about 80 cells per linear inch.

Claim 18

The bandage of claim 15 including a layer of silicone coated release paper attached to the exposed bottom of said pressure sensitive adhesive layer.

Claim 19

The method of forming the bandage of claim 16 comprising the steps of kneading polyisobutylene rubber of an average molecular weight of 81,000 to 99,000, sodium carboxymethylcellulose, and gelatin; adding this kneaded mixture with vigorous agitation to a heptane solution containing a polyisobutylene sticky mass of an average molecular weight of from 10,000 to 11,700, terpene resin, mineral oil, and butylated hydroxytoluene to dissolve the polyisobutylenes, terpene resin, mineral oil and butylated hydroxytoluene and form an adhesive slurry containing finely divided insoluble sodium carboxymethylcellulose and gelatin; pouring said slurry onto a sheet of silicone coated release paper and drying to evaporate the heptane and form an adhesive/paper laminate; forming a second laminate consisting of semi-open cell flexible polyurethane foam having about 80 cells per linear inch with from about 30 to about 70% of the cells ruptured and a flexible polyurethane film coating; joining the two laminates with the exposed surface of the foam contacting the exposed surface of the adhesive layer by passing gently between pressure rollers.