Roehm Gmbh & Co Kg

Evonik Roehm Gmbh

Evonik Rohm Gmbh

Jann Schmidt

Herbert Groothues

Markus Parusel

Guenther Ittmann

Wolfgang Scharnke

Hans Lichtenstein

Guenther Dickhaut-Bayer

Helmut Haering

Christian Roth

Thomas Hasskerl

Hans Lorenz

Christoph Krohmer

Wojciech Pisula

Wangelis Karampougioukis

Sabine Schwarz-Barac

Eduard Albrecht

Berthold Schoenig

Uwe Schneider

Stephan Neumayer

Heiko Rochholz

Alexander Baum

Martin Berkenkopf

Peter Stein

Xin Lu

A process for producing a light guide plate includes producing a colorless transparent sheet from a colorless transparent material by extrusion with a polishing stack. A printed reflector film is laminated in-line to the colorless transparent sheet. The printed reflector film includes: a thermoplastic reflector film which is opaque white or translucent white and made of a thermoplastic material; and a colorless thermoplastic printed on the thermoplastic reflector film. There is no direct optical contact between the colorless transparent sheet and the thermoplastic reflector film. A glass transition temperature of the printed colorless thermoplastic is above 25&#xb0; C. and below glass transition temperatures of the colorless transparent material of the colorless transparent sheet and of the thermoplastic material of the thermoplastic reflector film.

Light guide plate and method for the production thereof

The present invention relates to light guide bodies having improved luminous intensity and transparency, to a method for their production and to their use.

Light guide body having high luminous intensity and high transparency

The invention relates to light guide plates, which are suitable for backlighting LCD monitors as well as information and advertising signs and which are illuminated at the edges and re-emit the light fed at the edges via at least one of the two surfaces located perpendicular to the edges. For the light of a light source that is fed at the edges to be able to leave the light guide plate again via one of the surfaces by overcoming total reflection, the light rays in the light guide plate have to be deliberately deflected. At one of the two surfaces of the light guide plate, the light guide plates are provided with optical impurities (), which are protected against damage by a film (). Furthermore, a method for the simplified application of said impurities is provided.

Light guide plate having embedded impurities and method for the production thereof

A coated sheet-like plastics material comprising a) as base, a thermoplastic substrate; and b) on the base, a photocatalytically active coating comprising a water-spreading layer which involves either a sol-adhesion-promoter layer, layer b1+2), comprising an adhesion promoter and a colloid sol, or a colloid-sol layer b2) arranged on an adhesion-promoter layer b1) applied on the substrate a), and a photocatalytically active layer b3) arranged on the water-spreading layer b1+2) or b2), where b3) is obtainable through application and drying of a mixture comprising, based on the solids content of the mixture in percent by weight b31) from 1 to 25% of titanium dioxide and b32) from 75 to 99% of silicon dioxide and/or of a metal oxide which is not soluble in water or of an anionically modified silicon dioxide or metal oxide; where the titanium dioxide is particulate with an average primary-particle size smaller than 10 nm. In-line process for producing said material, and also use as roofing material or as glazing material, preferably in areas with moist conditions. The coated sheet-like plastics material of the invention combines water-spreading properties with photocatalytic activity, without any damage to the thermoplastic substrates. The coated sheet-like plastics substrate of the invention is produced in a relatively uncomplicated, inexpensive and fast in-line process and, in use, provides impressive substrate stability and impressive effectiveness of the coating in resisting initial algal growth.

Coated sheet-like plastic material with reduced tendency to colonization by algae, process for the in-line production thereof and use

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 Vis in the range from 0.1 to 40 &#x3bc;m, 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 Vis in the range from 10 to 150 &#x3bc;m 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 V, where the transmittance of the diffuser sheets is in the range from 20 to 70% and their scattering power is greater than 0.3, where the ratio of the square of average surface roughness of the polymethyl methacrylate layer Rto the third power of the size of the spherical particles (B) R/Dis in the range from 0.0002 to 0.1300 &#x3bc;m.

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

The present invention relates to rear-projection screens which have at least one scattering layer encompassing scattering particles and has at least one backing layer, characterized in that the halved-intensity angle of the scattering layer is greater than or equal to 15&#xb0; and the halved-intensity angle of the backing layer is smaller than or equal to 6.5&#xb0;, where the gloss Rof the backing layer is smaller than or equal to 70.

Stable rear projection screen and method for the production thereof

The present invention relates to a rear-projection screen encompassing at least one light-scattering polymethyl methacrylate layer, which comprises a polymethyl methacrylate matrix and spherical scattering particles (A) and spherical particles (B) with a different median particle size V, where the spherical scattering particles (A) have a median size Vin the range from 0.1 to 40 &#x3bc;m, the difference between the refractive index of the spherical scattering particles (A) and that of the polymethyl methacrylate matrix being in the range from 0.02 to 0.2, where the spherical particles (B) have a median size Vin the range from 10 to 150 &#x3bc;m, the difference between the refractive index of the spherical particles (B) and that of the polymethyl methacrylate matrix being in the range from 0 to 0.2, and 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, where the concentration of the spherical scattering particles (A) c, the thickness of the light-scattering polymethyl methacrylate layer dand the size of the spherical scattering particles (A) Dis selected in such a way that the ratio c*d/Dis in the range from 0.001 to 0.015% by weight*mm/&#x3bc;m, the concentration of the spherical particles (B) c, the thickness of the light-scattering polymethyl methacrylate layer dand the size of the spherical particles (B) Dis selected in such a way that the ratio c*d/Dis in the range from 0.000005 to 0.002% by weight*mm/&#x3bc;mand the ratio of the square of average surface roughness of the polymethyl methacrylate layer Rto the third power of the size of the spherical particles (B) R/Dis in the range from 0.0002 to 0.1300 &#x3bc;m.

Scratch-resistant rear projection screen and method for producing the same

A rear-projection screen that has at least one light-scattering polymethyl methacrylate layer in which is embedded spherical plastic particles; the previously described rear-project screen that has an additional plastic sheet that does not have embedded scattering beads; and a method of making a rear-projection screen.

Rear projection screen and method for the production thereof

The invention relates to an illuminative device essentionaly comprising a light source and a diffusing cover which is assigned to the light source and is made of colored plastic. The light source consites of one or several light-emitting diodes (LEDs) emitting a colored an substantially monocromatic light. The diffusing cover assigned thereto has a transmition (DIN 5036) of at least 35% and a reflection (DIN 5036) of at least 15% with the wavelength of the light-emitting diode operating at relative maximum energy.

Illuminative device

The present invention relates to a light-guide body, which has at least one light-entry surface and at least one light-exit surface, the ratio of the light-exit surface area to the light-entry surface area being at least 4, comprising at least one light-guiding layer with a thickness of at least 2 mm, characterized in that the light-guiding layer comprises at least 60% by weight, expressed in terms of the weight of the light-guiding layer, of polymethyl methacrylate and from 0.001 to 0.08% by weight, expressed in terms of the weight of the light-guiding layer, of spherical barium sulphate particles with an average diameter in the range of from 0.3 to 20 &#x3bc;m.

Growing community of inventors

Rockaway, NJ, United States of America

Jann Schmidt