Dressing

Claim 2

The dressing of claim 1 wherein said wound and skin contacting adhesive layer (14) is a homogeneous blend of about 40% by weight of low molecular weight polyisobutylene, about 20% by weight of sodium carboxymethylcellulose, about 20% by weight of pectin, and about 20% by weight of gelatin.

Claim 3

The dressing of claim 2 wherein said open-cell polymeric foam (12) is polyurethane foam and said water-impervious polymeric film (11) is polyurethane.

Claim 4

The dressing of claim 3 wherein said wound and skin contacting adhesive layer (14) is from about 0.02 inches (0.5 mm) to about 0.1 inches (2.54 mm) in thickness, said polyurethane foam layer (12) is about 0.03 inches (0.76 mm) to about 0.1 inches (2.54 mm) in thickness, and said water-impervious polyurethane layer (11) is about 0.001 inches (0.0254 mm) to about 0.003 inches (0.076 mm) in thickness.

Claim 5

The dressing of any preceding claim wherein said wound and skin contacting adhesive layer (14) is bonded directly to the bottom surface of said foam layer (12).

Claim 6

The dressing of claim 1 wherein said wound and skin contacting adhesive layer (14) is bonded to said open-cell polymeric foam (12) by a second adhesive layer (13) and said second adhesive layer (13) consists essentially of a homogeneous blend of from about 30% to about 70% by weight of one or more pressure sensitive adhesive materials and one or more optional thermoplastic elastomers, from about 10% to about 65% by weight of one or more water dispersable hydrocolloids and up to 50% by weight of one or more optional water swellable cohesive strengthening agents and/or one or more optional hydratable polymers provided that said water dispersable hydrocolloids, water swellable cohesive strengthening agents, and hydratable polymers together are present at no more than about 70% by weight of said adhesive layer, from about 5% to about 15% by weight of a plasticizer or solvent, and from about 15% to about 25% by weight of a tackifier.

Claim 7

The dressing of claim 6 wherein, in said second adhesive layer (13), said pressure sensitive adhesive material is selected from natural rubber, silicone rubber, acrylonitrile rubber, polyurethane rubber, and low molecular weight polyisobutylenes, said optional thermoplastic elastomer if present is selected from medium molecular weight polyisobutylenes, butyl rubber, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, and styrene-ethylene/butylenestyrene copolymers, said water dispersable hydrocolloid is selected from sodium carboxymethylcellulose, calcium carboxymethylcellulose, pectin, gelatin, guar gum, locust bean gum, collagen, and gum karaya, said optional water swellable cohesive strengthening agent if present is selected from water-insoluble cross-linked sodium carboxymethylcellulose, water-insoluble starch-acrylonitrile graft copolymer, and water-insoluble cross-linked dextran, said optional hydratable polymer if present is selected from gluten and long chain polymers of methyl vinyl ether/maleic acid, said plasticizer or solvent is mineral oil, and said tackifier is a terpene resin.

Claim 8

The dressing of claim 7 wherein said second adhesive layer (13) is a homogeneous blend of from about 35% to about 50% by weight of low molecular weight polyisobutylenes and one or more optional thermoplastic elastomers selected from medium molecular weight polyisobutylenes, butyl rubber, and styrene-isoprene-styrene copolymers, from about 30% to about 50% by weight of one or more water dispersable hydrocolloids, one or more optional water swellable cohesive strengthening agents, and one or more optional hydratable polymers, from about 5% to about 15% by weight of mineral oil and from about 15% to about 25% by weight of a terpene resin tackifier.

Claim 9

The dressing of claim 8 wherein said wound and skin contacting adhesive layer (14) is a homogeneous blend of about 40% by weight of low molecular weight polyisobutylene, about 20% by weight of sodium carboxymethylcellulose, about 20% by weight of pectin, and about 20% by weight of gelatin.

Claim 10

The dressing of claim 9 wherein said second adhesive layer (13) is a homogeneous blend of from about 18% by weight of low molecular weight polyisobutylenes, about 20% by weight of medium molecular weight polyisobutylenes, about 18% by weight of sodium carboxymethylcellulose, about 15% by weight of gelatin, about 20% by weight of terpene resin, about 8.5% by weight of mineral oil, and about 0.5% by weight of butylated hydroxytoluene.

Claim 11

The dressing of claim 10 wherein said open-cell polymeric foam is polyurethane foam and said water impervious polymeric film is polyurethane.

Claim 12

The dressing of claim 11 wherein said wound and skin contacting adhesive layer (14) is from about 0.02 inches (0.5 mm) to about 0.1 inches (2.54 mm) in thickness, said second adhesive layer is from about 0.005 inches (0.127 mm) to about 0.02 inches (0.5 mm) in thickness, said polyurethane foam layer is about 0.03 inches (0.76 mm) to about 0.1 inches (2.54 mm) in thickness, and said water-impervious polyurethane layer is about 0.001 inches (0.0254 mm) to about 0.003 inches (0.076 mm) in thickness.

Claim 13

The dressing of claim 6 wherein a layer (31) of deodorizing material is interposed between the two adhesive layers (14, 13).

Claim 14

The dressing of claim 13 wherein said layer (31) of deodorizing material contains activated carbon.

Claim 15

A method for preparing a multi-layered dressing according to claim 6 which comprises forming a homogeneous dough, consisting essentially of the one or more low molecular weight polyisobutylenes and the one or more hydrocolloids, by mechanical mixing, forming an adhesive layer by mixing one or more hydrocolloid gums, one or more pressure sensitive adhesive materials, tackifier and plasticizer in an organic solvent such as heptane or hexane, applying the resulting adhesive slurry to a web of silicone coated release paper and evaporating the solvent so dispersing the dried hydrocolloid throughout the adhesive layer, compressing with a laminate of semi-open-cell flexible polymeric foam having a water-impermeable polymeric coating or skin on one side, and stripping away the silicone coated release paper from the adhesive layer and pressing together with heat the adhesive layers to form the dressing.