Method for the production of scratch resistance articles and the scratch resistance articles so produced

• US 5,492,769 A
• Filed: 09/17/1992
• Issued: 02/20/1996
• Est. Priority Date: 09/17/1992
• Status: Expired due to Fees

• Current Assignee: Wayne State University
• Original Assignee: Wayne State University
• Inventors: Brennan, Antony B., Adair, James H., Singh, Rajiv K., Pryor, Roger W.
• Primary Examiner(s): Nelson, Peter A.
• Application Number:
  US07/948,354
• Time in Patent Office: 1,251 Days
• Field of Search: 428/552
• US Class Current: 428/552
• CPC Class Codes: B05D 5/02 to obtain a matt or rough surface
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 2217/42 consisting of particles only
• CPC Class Codes: C04B 2111/00362 Friction materials, e.g. used as brake linings, anti-skid materials
• CPC Class Codes: C04B 41/0072 Heat treatment
• CPC Class Codes: C04B 41/4545 applied as a powdery material
• CPC Class Codes: C04B 41/5053 non-oxide ceramics carbon or carbonisable materials C04B41/5001
• CPC Class Codes: C04B 41/5323 to make grain visible, e.g. for obtaining exposed aggregate concrete
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: C08J 7/06 with compositions not containing macromolecular substances
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 26/02 applying molten material to the substrate
• CPC Class Codes: Y10T 428/12056 Entirely inorganic

Abstract

A method is provided for improving the scratch or surface wear resistance of substrates by embedding discrete, hard particles within the surface layer of the substrate. Discrete, hard particles are applied to the substrate surface and then embedded within and bonded to the surface layer of the substrate by softening the substrate surface layer by either thermal or solvent means. Suitable substrate materials include thermoplastics, thermoset plastics, polymers, glass, soft metals, and composites. Suitable hard particles include diamond, silicon dioxide, aluminum oxide, cubic boron nitride, boron carbide, silicon carbide, silicon nitride, tantalum carbide, titanium carbide, titanium nitride, tungsten carbide, and zirconia alloys containing at least one phase stabilization additive selected from the group yttrium, hafnium, calcium, magnesium, and cesium. Scratch resistant substrates or articles having discrete, hard particles embedded within the surface layer of the substrate or article are also provided. These substrates or articles essentially have the surface wear characteristics of the hard particles or material embedded within the surface layer. Thus, it is possible to prepare plastic materials or articles having significantly improved scratch or surface wear resistance without significantly increasing the weight or external dimensions of the plastic materials or articles.

Claims

1. An article with improved scratch resistance, said article having discrete particles of a hard material selected from the group consisting of diamond, silicon dioxide, aluminum oxide, cubic boron nitride, boron carbide, silicon carbide, silicon nitride, tantalum carbide, titanium carbide, titanium nitride, tungsten carbide, and zirconia alloys, wherein said discrete particles are embedded within and bonded to the surface layer of the article and at least partially exposed on the surface of the article, wherein the embedded discrete particles provide improved scratch resistance to the surface of the article and wherein the article is produced by the steps of coating the surface of the article with discrete particles of the hard material;

softening the surface layer of the article;

embedding the discrete particles of the hard material within the softened surface layer of the article; and

allowing the surface layer of the article to reharden, wherein the discrete particles of the hard material are embedded within and bonded to the surface layer of the article and at least partially exposed on the surface of the article.

2. An article as defined in claim 1, wherein the article is plastic, polymer, glass, metal, or composite.

3. An article as defined in claim 1, wherein a colloidal or sol suspension of the discrete particles is used to coat the surface of the substrate.

4. An article as defined in claim 1, wherein the surface layer of the article is softened thermally.

5. An article as defined in claim 1, wherein the surface layer of the article is softened by exposure to a solvent.

6. An article as defined in claim 4, wherein the hard particles are embedded in the softened article surface under the effect of pressure.

7. An article as defined in claim 5, wherein the hard particles are embedded in the softened article surface under the effect of pressure.

8. An article as defined in claim 6, wherein the article is optically clear.

9. An article as defined in claim 7, wherein the article is optically clear.