Medical patch material and a process for its production

• US 5,641,506 A
• Filed: 12/20/1995
• Issued: 06/24/1997
• Est. Priority Date: 03/18/1993
• Status: Expired due to Fees

• Current Assignee: Lohmann GmbH & Company KG
• Original Assignee: Lohmann GmbH & Company KG
• Inventors: Ludwig, Karin, Talke, Volker, Reinhold, Karl-Heinz, Seeger, Kurt
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): Shelborne, Kathryne E.
• Application Number:
  US08/532,742
• Time in Patent Office: 552 Days
• Field of Search: 424/448, 424/449, 424/443
• US Class Current: 424/443
• CPC Class Codes: A61B 10/0035 Vaccination diagnosis other than by injuring the skin, e.g. allergy test patches
• CPC Class Codes: A61F 13/023 wound covering film layers without a fluid retention layer
• CPC Class Codes: A61F 13/0269 Tapes for dressing attachment for stoma bags A61F5/443; for nappies or sanitary towels A61F13/58; wound closure tapes A61B17/085; for surgical drapes A61B46/00; attaching catheters A61M25/02
• CPC Class Codes: A61F 13/0276 Apparatus or processes for manufacturing adhesive dressings or bandages
• CPC Class Codes: A61F 2013/00659 polymeric base
• CPC Class Codes: A61F 2013/00706 basis weight
• CPC Class Codes: A61F 2013/00782 with macroscopic openings
• CPC Class Codes: A61F 2013/00859 with macroscopic openings
• CPC Class Codes: A61F 2013/00868 thin film
• CPC Class Codes: A61F 2013/00876 vapour permeability >500 g/mg/24h
• CPC Class Codes: A61L 15/425 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 15/58 Adhesives
• CPC Class Codes: C09J 2301/204 the adhesive coating being discontinuous
• CPC Class Codes: C09J 7/22 Plastics; Metallised plastics
• CPC Class Codes: C09J 7/35 Heat-activated

Abstract

A medical patch material has a support coated with an even and porous spread of pressure sensitive hot-melt adhesive coating, formed by means of gravure printing, has a sufficient porosity and a resulting vapor permeability to skin moisture on the one hand, as well as an absolute bacteria-impermeability and reliable adherence of the patch material on the other hand. This is achieved by the fact that the pressure sensitive hot-melt adhesive spread:

a) forms coherent webs in the lengthwise and transverse direction, which include island-shaped adhesive-free areas;

b) that the proportion of the adhesive-free areas amounts to between 30 and 60%, preferably between 40 and 57% of the total surface, and

c) that the coat weight of the adhesive amounts to between 30 and 160 g/m², preferably between 40 and 120 g/m².

Claims

1. Medical patch material having a support coated with an even and porous spread of a pressure-sensitive adhesive in such a manner that

a) it forms coherent webs in the lengthwise and transverse direction, which include island-shaped adhesive-free areas;

and

b) the proportion of the adhesive-free areas amounts to between 30 and 60% of the total surface, and wherein

(1) the pressure-sensitive adhesive is a pressure sensitive hot-melt adhesive based on block copolymers having a viscosity at 120°

to 180°

C. of between 1,000 and 20,000 mPa.s,

(2) the pressure sensitive hot-melt adhesive is applied on the supporting material by means of gravure printing,

(3) the patch material has a water-vapor permeability of more than 2,000 g/m² /24 h, and

(4) the coat weight of the adhesive amounts to between 30 and 160 g/m².

2. The medical patch material according to claim 1 wherein the adhesive-free islands regularly arranged in the pressure sensitive hot-melt adhesive have a maximum distance of 3 mm to one another.

3. The medical patch material according to claim 1 wherein the base of the adhesive webs has a maximum width of 3 mm.

4. The medical patch material according to claims 1, 2 or 3 wherein the supporting material is a textile fabric.

5. The medical patch material according to claim 1 wherein the supporting material is a vapor-permeable film.

6. The medical patch material according to claim 1 which is an adhesive patch, a patch-type bandage, an adhesive dressing, a securing patch, an allergy-test patch, or a bacteria-proof wound dressing.

7. The medical patch material according to claim 6 which is sterilizable.

8. The medical patch material according to claim 1 wherein the proportion of the adhesive-free areas amounts to between 40 and 57% of the total surface.

9. The medical patch material according to claim 1 wherein the viscosity at 120°

to 180°

C. of the hot-melt adhesive is between 2,000 and 10,000 mPa.s.

10. The medical patch material according to claim 1 wherein the coat weight of the adhesive is between 40 and 120 g/m².

11. A process for the production of the medical patch material of claim 1 which comprises

coating a support with a pressure sensitive hot-melt adhesive based on block copolymers having a viscosity at 120°

to 180°

C. of between 1,000 and 20,000 mPa.s by means of a heatable direct gravure print coater which uses both a rigid and an elastic coating knife in adhesive uptake in such a porous manner that the adhesive forms coherent webs in the longitudinal and transverse direction which include adhesive-free, island-shaped areas,

the proportion of the adhesive-free areas amounting to between 30 and 60% of the total surface and the base of the adhesive webs having a maximum width of 3 mm, and

the patch material having a water-vapor permeability of at least 3,000 g/m² /24 h.

12. A process according to claim 11 wherein the adhesive substance is applied on the support at a coat weight of between 30 and 160 g/m².

13. A process according to claim 1 wherein a block copolymer having a viscosity at 120°

-180°

C. of between 1,000 and 20,000 mPa.s, preferably between 2,000 and 10,000 mPa.s is used as adhesive.

14. A process according to claim 11 wherein the adhesive-free islands are regularly arranged in the pressure-sensitive hot-melt adhesive and have a maximum distance of 3 mm to one another.

15. A process according to claim 11 wherein the proportion of the adhesive-free areas amounts to between 40 and 57% of the total surface.

16. A process according to claim 12 wherein the coat weight is between 40 and 120 g/m².