Composite films with an obscuration area

Patent metadata

Field	Value
Publication number	US-12486432-B2
Application number	US-202118028237-A
Country	US
Kind code	B2
Filing date	Sep 24, 2021
Priority date	Sep 28, 2020
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

The present invention relates to a composite film comprising a polyvinyl acetal with an obscuration area which is provided on a carrier film.

First claim

The invention claimed is:

1 . A composite film comprising:
a film A containing a polyvinyl acetal and optionally a plasticiser; and a carrier film, wherein film A is provided with an obscuration area, wherein the obscuration area is provided by a printed or coated ink layer on the surface of film A not facing the carrier film, wherein a surface roughness Rz of the surface of film A to be coated or printed is from 0.1 to 3.0 μm, measured before said surface is coated or printed on, and wherein a surface roughness Rz of the carrier film on the surface in contact with film A is from 2.0 to 6.0 μm, measured before the carrier film and the film A come into contact.

2 . The composite film according to claim 1 wherein the carrier film contains a polymer selected from the group consisting of polylactic acid, acrylonitrile-butadiene-styrene copolymer, polyamides, polycarbonates, polyethylene terephthalate, polyethylene terephthalate copolymers, polyhydroxyalkanoates, polyurethanes, polyolefins, acrylonitrile styrene acrylate, polyacrylates and polymethacrylates, polyvinyl alcohol, and TAC (cellulose tri acetate).

3 . The composite film according to claim 1 wherein a thickness of the film A is from 15 to 40 μm.

4 . The composite film according to claim 1 wherein a thickness of the carrier film is from 25 to 250 μm.

5 . The composite film according to claim 1 wherein film A is adhered to the carrier film with an adhesive strength from 0.05 to 10 N/3 cm.

6 . The composite film according to claim 1 wherein the ink comprises a binder selected from the group consisting of vinyl pyrrolidone, a water-soluble acrylic resin, an alcohol-soluble resin, an acrylic resin, a styrene-maleic resin, styrene-acrylate resin, a polyurethane resin, a polyvinyl acetal resin, a polyvinyl alcohol resin and a ketone resin.

7 . A process for the production of the composite film according to claim 1 comprising the following steps, in that order:
a) providing a carrier film;
b) coating one surface of the carrier film with a solution comprising a solvent, the polyvinyl acetal or polyvinyl ethylene acetal, and the optional plasticiser;
c) evaporating the solvent to obtain the film A on the one surface of the carrier film; and
d) providing an obscuration area by printing or coating the surface of the film A not in contact with the carrier film with an ink layer.

8 . A process for the production of a windshield comprising two sheets of glass, combined by an interlayer film comprising a film A containing a polyvinyl acetal and optionally, a plasticiser; and a film B containing a polyvinyl acetal and a plasticiser in an amount of at least 22% by weight; comprising the following steps, in that order:
a) positioning the composite film according to claim 1 to the first glass sheet with the film A facing the first glass sheet; b) peeling off the carrier film from the film A; and c) positioning the film B on the film A or on the second glass sheet; and d) providing a stack of the layers comprising first glass sheet-film A-film B-second glass in that order; and e) laminating the stack obtained in step d) to produce the windshield.

9 . A process for the production of a windshield comprising two sheets of glass, combined by an interlayer film comprising a film A containing a polyvinyl acetal and optionally, a plasticiser; and a film B containing a polyvinyl acetal and a plasticizer in an amount of at least 22% by weight; comprising the following steps, in that order:
a) positioning the composite film according to claim 1 to the film B with the film A facing the film B; b) peeling off the carrier film from the film A; c) providing a stack of the layers comprising first glass sheet-film A-film B-second glass in that order; and d) laminating the stack obtained in step c) to produce the windshield.

10 . A process for the production of a windshield comprising two sheets of glass, combined by an interlayer film comprising a film A containing a polyvinyl acetal and optionally, a plasticiser; and a film B containing a polyvinyl acetal and a plasticizer in an amount of at least 22% by weight; comprising the following steps, in that order:
a) providing the composite film according to claim 1 and peeling off the carrier film from the film A; b) positioning the film A on the first glass sheet with the surface of film A provided with a printed or coated ink layer away from the first glass sheet; c) positioning the film B on film A or on the second glass sheet; d) providing a stack of the layers comprising first glass sheet-film A-film B-second glass in that order; and e) laminating the stack obtained in step d) to produce the windshield.

11 . A windshield obtained according to the process of claim 8 .

Assignees

• Kuraray Europe Gmbh

Inventors

• Keller Uwe
• Steuer Martin
• Muguruma Shinichi
• Oomoto Hideki
• Mummy Florian

Classifications

• B32B17/10605

  Type of plasticiser · CPC title

• B32B17/10688

  Adjustment of the adherence to the glass layers · CPC title

• B32B2369/00

  Polycarbonates · CPC title

• B32B17/10275

  on interlayer · CPC title

• C09D11/102

  containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds · CPC title