Leather with a finish on the buffed surface, and process for producing a leather of this type

• US 6,177,198 B1
• Filed: 07/07/1999
• Issued: 01/23/2001
• Est. Priority Date: 07/07/1998
• Status: Expired due to Term

• Current Assignee: Philipp Schaefer
• Original Assignee: Philipp Schaefer
• Inventors: Schaefer, Philipp
• Primary Examiner(s): Nakarani, D. S.
• Assistant Examiner(s): Paulraj, Christopher
• Application Number:
  US09/348,967
• Time in Patent Office: 566 Days
• Field of Search: 428/423.1, 428/423.3, 428/423.4, 428/212, 428/213, 428/214, 428/215, 428/216, 428/217
• US Class Current: 428/423.4
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: C14B 7/02 Composite leathers with one or more laminae of plastics material B32B
• CPC Class Codes: C14C 11/006 using polymeric products of isocyanates (or isothiocyanates) with compounds having active hydrogen
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/24983 Hardness
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31554 Next to second layer of polyamidoester
• CPC Class Codes: Y10T 428/31558 Next to animal skin or membrane

Abstract

The leather has a finish on a buffed surface. The finish layer is formed in a plurality of layers including an outer layer with a given hardness and a particular surface effect preformed in a hot substrate having a structure corresponding to the particular surface effect the outer layer being formed of a solidified, cross-linked, hydrolysis-resistant, lightfast, polyurethane-containing dispersion, and having a thickness of between 0.01 and 0.08 mm, and an inner layer bonded to the buffed surface leather and comprising a solidified, highly crosslinked, hydrolysis-resistant, lightfast, polyurethane-containing dispersion and having a hardness less than a hardness of the outer layer.

Claims

1. A leather assembly, comprising:

a leather having a buffed surface;

a finish layer on said buffed surface, said finish layer comprising a plurality of layers including

an outer layer with a given hardness and a particular surface structure preformed in a hot substrate having a structure corresponding to the particular surface structure, said outer layer being formed of a solidified, cross-linked, hydrolysis-resistant, lightfast, polyurethane-containing dispersion, and having a thickness of between 0.01 and 0.08 mm, and

an inner layer bonded to said buffed surface leather and comprising a solidified, crosslinked, hydrolysis-resistant, lightfast, polyurethane-containing dispersion and having a hardness less than a hardness of said outer layer, said inner layer being thinner than said outer layer and comprising two sublayers formed of a solidified, crosslinked polyurethane dispersion and fused to one another by application of pressure and heat.

2. The leather assembly according to claim 1, which further comprises an intermediate layer between said outer layer and said inner layer, said intermediate layer comprising a solidified, crosslinked, hydrolysis-resistant, lightfast, polyurethane-containing dispersion, having a Shore hardness lower than the given hardness of said outer layer, and being inseparably bonded with said outer layer.

3. The leather assembly according to claim 1, wherein said leather is a natural leather and said inner layer has a thickness of between 0.008 and 0.03 mm and is thinner than said outer layer.

4. The leather assembly according to claim 1, wherein said inner layer forms a porous film.

5. The leather assembly according to claim 1, wherein said outer layer is elastomeric and does not have thermoplastic properties and recovers completely after elongation at a temperature of between 100 and 120°

C., and said inner layer is substantially not elastomeric and has a greater residual elongation than said outer layer at a temperature of from 100 to 120°

C.

6. The leather assembly according to claim 1, wherein said outer layer is a porous layer.

7. The leather assembly according to claim 6, wherein said outer layer has through-pores formed therein, said through-pores having walls lined with a material of said inner layer adjacent said outer layer.

8. The leather assembly according to claim 1, wherein said outer layer contains pigments.

9. The leather assembly according to claim 1, which comprises hollow microspheres embedded into said outer layer.

10. The leather assembly according to claim 1, which comprises hollow microspheres embedded into said inner layer.

11. The leather assembly according to claim 1, wherein said outer layer consists essentially of a solidified polyester-polyurethane dispersion having a softening point in a dry condition between 180 and 240°

C. without addition of a crosslinking agent.

12. The leather assembly according to claim 1, wherein said outer layer consists essentially of a solidified polyether-polyurethane dispersion having a softening point in a dry condition between 180 and 240°

C. without addition of a crosslinking agent.

13. The leather assembly according to claim 1, wherein said inner layer is composed predominantly of a solidified polyester-polyurethane dispersion and in a dry state, without addition of a crosslinking agent, has a softening point of between 45 and 95°

C.

14. The leather assembly according to claim 1, wherein said inner layer is composed predominantly of a solidified polyether-polyurethane dispersion and in the dry state, without addition of a crosslinking agentm, has a softening point of between 45 and 95°

C.

15. The leather assembly according to claim 1, which further comprises an intermediate layer comprising a solidified, solids-containing polyurethane solution between said buffed upper surface of said leather and said inner layer.

16. The leather assembly according to claim 15, wherein said intermediate layer has a thickness of between 0.001 and 0.002 mm.

17. The leather assembly according to claim 15, wherein said intermediate layer is formed by spraying said polyurethane solution onto said buffed surface of said leather and subsequently removing the solvent.

18. The leather assembly according to claim 15, wherein said intermediate layer has a solids content of less than 8% by weight relative to the dispersion of said intermediate layer.

19. The leather assembly according to claim 1, wherein said outer layer has a solids content of more than 35% by weight relative to the dispersion of said outer layer.

20. The leather assembly according to claim 1, wherein said outer layer has a density of less than 0.95 g/cm³.

21. The leather assembly according to claim 1, wherein said outer layer has been provided with a variety of different surface effects.

22. The leather assembly according to claim 21, wherein said outer layer is formed with representations or symbols during a production thereof.

23. The-leather assembly according to claim 22, wherein the representations or symbols are raised to project from an adjacent surface of said outer layer.

24. The leather assembly according to claim 23, wherein the thickness of said outer layer in the area of the raised representations and symbols is substantially equal to a thickness of said outer layer in an area of the adjacent surface.

25. The leather assembly according to claim 1, wherein the surface of said outer layer has markings formed thereon.

26. The leather assembly according to claim 1, wherein said outer layer has a nubuck-leather appearance.

27. The leather assembly according to claim 1, wherein at least some of said layers are formed with perforations.

28. The leather assembly according to claim 1, wherein said outer layer comprises a plurality of sublayers arranged one upon the other and formed by solidifying a polyurethane-containing dispersion sprayed onto a hot substrate.

29. The leather assembly according to claim 26, wherein said sublayers forming said outer layer have mutually different pigment contents.

30. The leather assembly according to claim 29, wherein the outer-layer sublayer forming one surface or visible side of the finish has a lower pigment content than the other layers.

31. The leather assembly according to claim 1, wherein said outer layer is a multicolor layer.

32. The leather assembly according to claim 1, wherein the leather assembly is substantially chromium-free.