Diffuser disk for LCD applications, method for the production and use thereof

US7629041B2 · kind B2 · utility

Assignee

• Evonik Röhm GmbH · DE

Inventors

• Markus Parusel · Messel, DE
• Jann Schmidt · Darmstadt, DE
• Herbert Groothues · Frankfurt, DE

Key dates

• Filing date: May 12, 2004
• Grant date: Dec 8, 2009
• Expiry date: May 7, 2025

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31855
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention relates to diffuser sheets for LCD applications encompassing at least one light-scattering polymethyl methacrylate layer which comprises a polymethyl methacrylate matrix and also from 0.5 to 59.5% by weight, based on the weight of the light-scattering polymethyl methacrylate layer, of spherical scattering particles (A) whose median size V50 is in the range from 0.1 to 40 μm, and whose refractive index differs from that of the polymethyl methacrylate matrix by a value in the range from 0.02 to 0.2, and from 0.5 to 59.5% by weight, based on the weight of the light-scattering polymethyl methacrylate layer, of spherical particles (B) whose median size V50 is in the range from 10 to 150 μm and whose refractive index differs from that of the polymethyl methacrylate matrix by a value in the range from 0 to 0.2, where the total concentration of the spherical scattering particles (A) and particles (B) is in the range from 1 to 60% by weight, based on the weight of the light-scattering polymethyl methacrylate layer, and the spherical scattering particles (A) and spherical particles (B) have a different median particle size V50, where the transmittance of the diffuser sh…