Laminated windshield with improved innerlayer

• US 4,153,526 A
• Filed: 03/03/1978
• Issued: 05/08/1979
• Est. Priority Date: 05/03/1976
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Lewis, Charles W., Cherenko, Joseph
• Primary Examiner(s): Robinson, Ellis P.
• Application Number:
  US05/883,079
• Time in Patent Office: 431 Days
• Field of Search: 260/732, 260/45.8 NT, 260/45.95 F, 428/437, 428/426, 428/411, 428/409, 428/913, 204/159.14, 204/159.18, 204/159.21, 427/54, 264/22, 156/272, 526/71, 526/1, 526/6
• US Class Current: 522/46
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10706 being photo-polymerized
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/1077 containing polyurethane
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/554 Wear resistance
• CPC Class Codes: B32B 2310/0831 using UV radiation
• CPC Class Codes: B32B 2605/006 Transparent parts other than made from inorganic glass, e.g. polycarbonate glazings
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C09J 129/14 Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/3163 Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.]

Abstract

Safety glass is made by laminating to a ply of glass a saturated polyvinyl acetal film incorporating a photoinitiator. The exposed surface of the film is irradiated with ultraviolet light which activates the photoinitiator which in turn initiates crosslinking of the polymer. The polymer film retains its desirable mechanical and optical properties while the crosslinked surface has improved solvent-abrasion resistance.

Claims

1. A transparent polymer film for use as an innerlayer in a bilayer safety glass laminate which consists essentially of a saturated thermoplastic polyvinyl acetal and an effective amount of a photoinitiator capable of initiating crosslinking of said film upon exposure to actinic radiation.

2. A film as described in claim 1, wherein the photoinitiator is selected from the group consisting of benzophenone, xanthone, acetophenone, anthraquinone, 2[2'"'"'-hydroxy 5'"'"'-methylphenyl] benzotriazole, anthrone, and butanedione.

3. A film as described in claim 2, wherein said photoinitiator is benzophenone.

4. A film as described in claim 2, wherein said photoinitiator is xanthone.