Composite of a disperesed gel in an adhesive matrix
AssigneeMinnesota Mining and Manufacturing Company
InventorRobert A. Asmus
Life of this patent
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Abstract
A composite of a gel of swollen hydrocolloid dispersed in a pressure sensitive adhesive matrix is provided. The gel has a natural or synthetically derived hydrocolloid swollen with a non-volatile swelling agent, such that the gel may have a shear modulus of less than 6.2.times.10.sup.6 dynes/cm.sup.2. The gel-adhesive composite has continued skin adhesion whether applied to or existing in dry or moist skin conditions. The gel contributes a high moisture vapor transmission rate to attempt to maintain dry skin conditions while the adhesive maintains skin adhesion. The gel-adhesive composite may be used in a variety of tape, dressing, bandage, drape, or other skin contacting usage and may optionally include antimicrobial agents to treat the skin while adhesion continues.
Claims48
A two-phase composite of fully formed, swollen, discrete gel particles dispersed in a dermatologically acceptable continuous pressure sensitive adhesive matrix, comprising:
- (a) a continuous phase of from about 5 weight percent to about 99 weight percent of a dermatologically acceptable hydrophobic pressure sensitive adhesive composition as said continuous matrix;
- (b) a dispersed phase of from about 1 to about 95 weight percent of said fully formed, swollen discrete gel particles having a shear modulus of less than about 6.2.times.10.sup.6 dynes/cm.sup.2, each said gel particle comprising a hydrocolloid swollen under non-reacting conditions with a non-volatile, hydrophilic hydrocolloid swelling agent prior to dispersion into said continuous matrix and having a ratio of weight fractions of hydrocolloid to swelling agent of from about 3:1 to about 1:99,
- wherein said hydrophilic non-volatile swelling agent is present in the composite and is essentially incompatible with said hydrophobic pressure sensitive adhesive composition, whereby phase separation of said continuous phase and said dispersed phase is essentially maintained;
- and
- wherein the composite has sufficient cohesive strength to avoid residuing on removal of the composite from a low density polyethylene surface during a T-peel adhesion test after conditioning of the composite on the surface at least about six days.
A composite according to claim 9, wherein said poly (N-vinyl lactam) comprises linear or crosslinked poly (N-vinyl pyrrolidone).
A gel-adhesive composite, comprising:
- a continuous phase of dermatologically acceptable hydrophobic pressure sensitive adhesive and a dispersed phase of fully formed, swollen, discrete hydrophilic gel particles, each said gel particle comprising a hydrocolloid swollen under non-reacting conditions with a hydrophilic non-volatile hydrocolloid swelling agent;
- said pressure sensitive adhesive, said hydrocolloid, and said swelling agent having interrelated weight fractions in the ranges identified with the area defined by lines A, A', and A.sup.2, in FIG. 2;
- wherein said fully formed, swollen, discrete gel particles have a shear modulus of less than about 6.2.times.10.sup.6 dynes/cm.sup.2 and wherein said hydrophilic non-volatile swelling agent is present in the composite and is essentially incompatible with said hydrophobic pressure sensitive adhesive composition, whereby phase separation is essentially maintained;
- and
- wherein the composite has sufficient cohesive strength to avoid residuing on removal of the composite from a low density polyethylene surface during a T-peel adhesion test after conditioning of the composite on the surface at least about six days.
A gel-adhesive composite, according to claim 48, further comprising a broad spectrum antimicrobial agent therein.
Dependencies are inferred from the claim text.