Antifogging plastic lens material

• US 5,476,682 A
• Filed: 12/03/1993
• Issued: 12/19/1995
• Est. Priority Date: 12/18/1992
• Status: Expired due to Fees

• Current Assignee: Rexam Industries Corp.
• Original Assignee: Rexam Industries Corp.
• Inventors: Evans, Joseph H.
• Primary Examiner(s): BELL, JANYCE A
• Application Number:
  US08/161,929
• Time in Patent Office: 746 Days
• Field of Search: 427/164, 427/412.5, 427/420, 427/428, 427/248.1, 427/393.5
• US Class Current: 427/164
• CPC Class Codes: B05D 7/02 to macromolecular substances, e.g. rubber treatment or coating of shaped articles made of macromolecular substances C08J7/00
• CPC Class Codes: B05D 7/57 the last layer being a clear coat
• CPC Class Codes: G02B 1/041 Lenses
• CPC Class Codes: Y10S 428/918 Material abnormally transparent
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/31768 Natural source-type polyamide [e.g., casein, gelatin, etc.]
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/3192 Next to vinyl or vinylidene chloride polymer

Abstract

An antifogging plastic material is disclosed that is particularly suitable for use as a disposable fog-resistant lens. The lens material comprises a substantially transparent polyester substrate; a layer of polyvinylidene chloride-containing polymer on the polyester substrate; a water permeable colloid layer on the polyvinylidene chloride-containing layer; and a polyvinyl alcohol-containing layer on the water permeable colloid layer.

Claims

1. A method of preparing an antifogging plastic lens material, said method comprising applying a layer of a polyvinyl alcohol containing-polymer in aqueous solution to the surface of a substrate comprised of a surface layer of a water permeable colloid, a layer of polyvinyl chloride-containing polymer beneath said water permeable colloid layer, and a polyester layer beneath said polyvinylidene chloride-containing layer;

and

drying the applied layer of polyvinyl alcohol-containing polymer on the said substrate.

2. A method according to claim 1 wherein the step of drying the applied layer of polyvinyl alcohol-containing polymer comprises heating the substrate and applied layer for a time and at a temperature sufficient to dry the polymer while avoiding any detrimental effects on the antifogging characteristics of the resulting lens material.

3. A method according to claim 1 wherein the step of applying the polyvinyl alcohol-containing polymer from an aqueous solution comprises applying the polyvinyl alcohol-containing polymer from an aqueous solution that contains about ten percent of a low aliphatic alcohol.

4. A method according to claim 1 and further comprising the steps of:

polymerizing vinyl acetate; and

thereafter

hydrolyzing the resulting polyvinyl acetate to form the polyvinyl alcohol-containing polymer, and prior to the step of applying the polyvinyl alcohol containing-polymer to the water permeable colloid layer on the surface of the substrate.

5. A method according to claim 4 wherein the step of hydrolyzing the polyvinyl acetate comprises hydrolyzing the polyvinyl acetate to between about 80 and 99 percent polyvinyl alcohol.

6. A method according to claim 1 in which the step of applying the polyvinyl alcohol-containing polymer is selected from the group consisting of:

roll coating, rotogravure, knife over roll, slot die coating, and Meyer rod.

7. A method of preparing an antifogging plastic material that is particularly suitable for use as a disposable fog-resistant lens, said method comprising:

applying a layer of a polyvinylidene chloride-containing polymer by vapor deposition to a polyester substrate;

applying a layer of a water permeable colloid to the polyvinylidene chloride-containing layer; and

applying a layer of a polyvinyl alcohol-containing polymer to the water permeable colloid layer on the polyvinylidene chloride-containing layer.

8. A method according to claim 7 wherein the step of applying a layer of a water-permeable colloid comprises applying the layer by vapor deposition.