PATTERNED SILICONE COATING

• US 20140171851A1
• Filed: 04/13/2012
• Published: 06/19/2014
• Est. Priority Date: 04/15/2011
• Status: Active Grant

• Current Assignee: KCI USA Incorporated (3M Company)
• Original Assignee: KCI USA Incorporated (3M Company)
• Inventors: Addison, Deborah
• Granted Patent: US 9,433,534 B2
• Time in Patent Office: Days
• US Class Current: 602/55
• CPC Class Codes: A61F 13/0206 with absorbent fibrous layers, e.g. woven or non-woven absorbent pads or island dressings
• CPC Class Codes: A61F 13/025 having a special distribution arrangement of the adhesive
• CPC Class Codes: A61F 13/0276 Apparatus or processes for manufacturing adhesive dressings or bandages
• CPC Class Codes: A61F 13/0283 for making adhesive or cohesive tape or fabrics therefor, e.g. coating or mechanical treatments
• CPC Class Codes: B05D 1/28 performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• CPC Class Codes: B05D 1/322 Removable films used as masks
• CPC Class Codes: B05D 3/0254 After-treatment
• CPC Class Codes: C09J 183/04 Polysiloxanes
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2423/106 in the substrate
• CPC Class Codes: C09J 2475/006 in the substrate
• CPC Class Codes: C09J 2483/00 Presence of polysiloxane
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: C09J 7/22 Plastics; Metallised plastics
• CPC Class Codes: C09J 7/26 Porous or cellular plastics
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

A method of applying a patterned coating of a silicone adhesive to a substrate sheet, comprising the steps of pattern coating a silicone precursor composition onto the substrate, followed by thermally curing the precursor composition coated on the substrate. The precursor composition is a viscous fluid, and the pattern coating is performed by suitably modified block printing, intaglio printing or screen printing methods. Also provided are coated substrates obtainable by the methods of the invention, and wound dressings comprising such coated substrates.

Claims

1. A method of applying a patterned coating of a silicone adhesive to a substrate sheet, comprising the steps of pattern coating a silicone precursor composition onto the substrate, followed by thermally curing the precursor composition coated on the substrate.

2. A method according to claim 1, wherein the step of pattern coating is performed by the steps of coating the silicone prepolymer composition onto an apertured support layer having holes and lands to provide a coated apertured support layer, followed by applying the coated apertured support layer to the substrate sheet, followed by removing the coated apertured support layer to leave a patterned layer of the silicone composition on the substrate sheet, whereby the pattern of the silicone on the substrate sheet substantially corresponds to the pattern of lands on the support layer.

3. A method according to claim 2, wherein said apertured support layer is a perforated sheet containing an array of perforations, said perforations having an area of at least about 4 mm².

4. A method according to claim 1, wherein the step of pattern coating is performed by providing a mold having a base surface and recesses in said surface corresponding to the desired adhesive pattern, filling said recesses with said silicone prepolymer composition, applying said substrate sheet to said base surface so that it contacts the prepolymer mixture in the recesses, curing said prepolymer mixture in contact with the substrate sheet, and removing the substrate sheet and silicone layer from the mold.

5. A method according to claim 4, wherein said mold is an intaglio printing roller.

6. A method according to claim 1, the method comprises providing a mold sheet having upper and lower surfaces and a pattern of apertures extending between said upper and lower surfaces, filling the apertures with the fluid silicone prepolymer composition, contacting one of said upper or lower surfaces with the support sheet so that said support sheet contacts said fluid silicone prepolymer composition in said apertures, curing the silicone prepolymer composition in contact with the support sheet, and removing the mold sheet.

7. A method according to claim 6, wherein said mold sheet is in the form of a screen printing roller having an array of apertures extending from an internal surface thereof to an external surface thereof, and wherein said silicone prepolymer is pumped into a channel within said roller to selectively flood apertures in a region of said roller where said external surface is in contact with the substrate sheet.

8. A method according to claim 1, wherein the silicone adhesive precursor composition is substantially solvent-free.

9. A method according to claim 2, wherein said pattern coating of silicone adhesive precursor composition is applied to cover from about 10% to about 50% of the surface area of the substrate sheet.

10. A method according to claim 2, wherein said coating of silicone adhesive precursor composition is applied in a pattern having a minimum dimension of about 2 mm.

11. A method according to claim 2, wherein said substrate sheet is a continuous semipermeable sheet having a moisture vapour transfer rate (MO/TR) before coating of at least about 500 g/m²/24 hr.

12. A method according to claim 1, wherein no primer layer is applied to said substrate sheet prior to said step of pattern coating with the silicone adhesive precursor composition.

13. A substrate sheet pattern coated with a silicone adhesive, obtainable by a method according to claim 2.

14. A wound dressing comprising a pattern coated substrate sheet according to claim 13.