SILICONE WOUND DRESSING LAMINATE AND METHOD FOR MAKING THE SAME

• US 20140058309A1
• Filed: 01/31/2012
• Published: 02/27/2014
• Est. Priority Date: 01/31/2011
• Status: Active Grant

• Current Assignee: KCI USA Incorporated (3M Company)
• Original Assignee: KCI USA Incorporated (3M Company)
• Inventors: Addison, Deborah, Stephens, Sally, Brosnan, Patrick Joseph
• Granted Patent: US 10,568,767 B2
• Time in Patent Office: Days
• US Class Current: 602/44
• CPC Class Codes: A61F 13/00987 Apparatus or processes for manufacturing non-adhesive dressings or bandages
• CPC Class Codes: A61F 13/01029 made of multiple layers
• CPC Class Codes: A61F 13/0203 with fluid retention members
• CPC Class Codes: A61F 13/0213 the fluid retention member being a layer of hydrocolloid, gel forming material
• CPC Class Codes: A61F 13/0223 characterized by parametric properties of the fluid retention layer, e.g. absorbency, wicking capacity, liquid distribution
• CPC Class Codes: A61F 13/0226 characterised by the support layer
• CPC Class Codes: A61F 13/0276 Apparatus or processes for manufacturing adhesive dressings or bandages
• CPC Class Codes: A61F 2013/00659 polymeric base

Abstract

A method of making a wound dressing comprising the steps of: providing an apertured substrate layer; coating the substrate layer with a fluid silicone prepolymer composition; thermally partially curing said silicone prepolymer composition to form a partially cured silicone coating on the substrate; laminating the coated substrate layer to a base layer to form a laminate having said partially cured silicone coating in contact with a surface of the base layer; followed by exposing the laminate to ionizing radiation, to further cure the partially cured silicone coating and to bond the silicone coating to said surface of the base layer. The radiation cure results in strong bonding between the siliconized substrate and incompatible base layers such as polyurethane foams. Also provided are wound dressings obtainable by the process of the invention.

Claims

1. A wound dressing comprising:

a base layer and an apertured layer laminated to the base layer, said apertured layer comprising an apertured substrate and a silicone coating layer on said substrate, wherein the apertured layer is directly bonded to the base layer and the peel strength required to separate the apertured layer from the base layer is greater than about 200 mN/crn.

2. The wound dressing according to claim 1, wherein the peel strength required to separate the apertured layer from the base layer is greater than about 300 mN/cm.

3. The wound dressing according to claim 1, wherein the apertured layer has been bonded to the base layer by ionizing radiation-induced bonding of said silicone coating to said base layer.

4. The wound dressing according to claim 1, wherein the base layer is in the form of a sheet of a polymeric film, foam, sponge, film, a nonwoven, knitted or woven textile, or a second layer comprising an apertured substrate and a silicone coating layer on said substrate.

5. The wound dressing according to claim 1, wherein at least a surface of the base layer to which the silicone coating is bonded is hydrophilic.

6. The wound dressing according to claim 1, wherein at least a surface of the base layer to which the silicone coating is bonded comprises a polyurethane or a hydrocolloid.

7. The wound dressing according to claim 6, wherein the base layer is a semipermeable polyurethane film or a hydrophilic polyurethane foam sheet.

8. The wound dressing according to claim 6, wherein the base layer is a nonwoven web comprising hydrogel-forming fibres.

9. The wound dressing according to claim 1, wherein said substrate is coated on both sides with said silicone coating, and the surface of said silicone coating opposite said base layer is non-adherent or tacky.

10. The wound dressing according to claim 1 further comprising an absorbent base layer in the fore of a sheet of absorbent or adsorbent material having upper and lower surfaces, and having the silicone-coated substrate bonded to both surfaces to provide a dressing material that can be applied to the wound in either orientation.

11. The wound dressing according to claim 1 further comprising an absorbent base layer in the form of a sheet of absorbent or adsorbent material having upper and lower surfaces, and having the silicone-coated substrate bonded to at least one of said surfaces, wherein said absorbent layer is further laminated to an adhesive-coated backing sheet to provide an absorbent dressing with a liquid-impermeable backing sheet.

12. The wound dressing according to claim 11, wherein the wound dressing is in the form of an island dressing wherein the adhesive-coated backing sheet is larger than the absorbent layer whereby a margin of the backing sheet extends around the edges of the absorbent layer.

13. The wound dressing according to claim 1 wherein the silicone-coated substrate is directly bonded to a liquid-impermeable backing sheet, or to a layer of adhesive on the said backing sheet.

14. The wound dressing according to claim 13, further comprising an absorbent layer or absorbent island laminated over the silicone-coated substrate, whereby at least part of the substrate is sandwiched between the absorbent layer and the base layer.

15. The wound dressing according to claim 1 comprising two pieces or one folded piece of silicone coated substrate encasing an absorbent or adsorbent layer, wherein the silicone coated substrate is larger than the absorbent or adsorbent layer whereby the substrate overlaps around the edges of the absorbent or adsorbent layer to form margins which are bonded together in face-to-face fashion to form an envelope of the silicone-coated substrate around the absorbent or adsorbent layer.

16. The wound dressing according to claim 1, further comprising a release sheet applied over a wound contacting surface of the wound dressing.

17. The wound dressing according to claim 1, wherein the wound dressing is sterile and is packaged in a microorganism-impermeable container.

22. A wound dressing of claim 1 obtainable by a method comprising the steps of:

providing an apertured substrate layer;

coating the substrate layer with a fluid silicone prepolymer composition;

thermally partially curing said silicone prepolymer composition to form a partially cured silicone coating on the substrate;

laminating the coated substrate layer to a base layer to form a laminate having said partially cured silicone coating in contact with a surface of the base layer; and

exposing the laminate to ionizing radiation, to further cure the partially cured silicone coating and to bond the silicone coating to said surface of the base layer.

18. A method of making a wound dressing comprising the steps of:

providing an apertured substrate layer;

coating the substrate layer with a fluid silicone prepolymer composition;

thermally partially curing said silicone prepolymer composition to form a partially cured silicone coating on the substrate;

laminating the coated substrate layer to a base layer to form a laminate having said partially cured silicone coating in contact with a surface of the base layer; and

exposing the laminate to ionizing radiation, to further cure the partially cured silicone coating and to bond the silicone coating to said surface of the base layer.

19. The method according to claim 18, wherein the silicone prepolymer composition comprises a polymerization inhibitor that is evaporated from said composition during said step of thermally partially curing,

20. The method according to claim 18, further comprising the step of packaging the laminate having said partially cured silicone coating in a microorganism-impermeable container prior to said step of exposing, and wherein said step of exposing also sterilizes said laminate.

21. The method according to claim 18 wherein the wound dressing comprises a base layer and an apertured layer laminated to the base layer, said apertured layer comprising an apertured substrate and a silicone coating layer on said substrate, wherein the apertured layer is directly bonded to the base layer and the peel strength required to separate the apertured layer from the base layer is greater than about 200 mN/crn.