Rohm Gmbh

Roehm Gmbh Chemische Fabrik

Rohm Gmbh Chemische Fabrik

Roehm Gmbh & Co Kg

Rohym Gmbh

Bowic B.v.

Manfred Krieg

Guenther Ittmann

Hans Lichtenstein

Winfried Wunderlich

Ludwig Hosch

Rainer Friederich

Armin Meyer

Werner Geyer

Norbert Rau

Werner Ude

Franz Wenzel

Wolfgang Pip

Okko K Dijkhuizen

Sabine Servaty

Peter R Szigeti

Silvia Ebert

Christa Weber

Heinz-Dieter Bruemmer

The invention relates to a method for producing block-shaped and plate-shaped polymethacrylimide foamed materials by copolymerizing methylacrylic acid and methylacryl nitrile, by subjecting the copolymerizate to a post-polymerization and cyclization in order to form polyimide, and by converting the same into a foamed material. The invention is characterized in that the copolymerization is carried out in the presence of a mixture containing at least three initiators with graduated half-life periods. The polymerization can be controlled especially well and yields polymerizate plates with thicknesses of up to 80 mm which can be easily foamed. The invention makes it possible to produce filling materials, especially plates and blocks containing electrically conductive particles.

Method for producing block-shaped polymethacrylimide foamed materials

Filled plastic molded articles based on polymethyl methacrylate (PMMA), which articles resemble granite, are prepared by preparing a casting resin suspension comprising: (A) 20-80 parts by wt. (pbw) of a liquid PMMA polymer precursor; (B) 0-75 pbw of a non-metallized particulate filler; (C) 0-5 pbw, based on the sum of components (A) and (B) of a polymerizable organosilicon compound; and (D) 0-2 wt. % of at least one pigment or colorant; suspending metallic appearing particles of a platelet-like stratified silicate (SS) in the particle size range of 20-500 .mu.m in an amount of 1-35 pbw, based on the sum of components (A) and (B); polymerizing the suspension under free radical conditions in a polymerization mold; and removing the polymerized article from the mold.

Method for producing high filler content plastic molded articles which

The invention relates to high filler content plastic molded articles, which articles have a surface having a pronounced glitter appearance resembling that of a microcrystalline mineral material. The glitter effect is obtained by incorporating glitter-producing particles having a plastic basis and a specific gravity &lt;2, in the composition of said articles. A method of manufacturing such molded articles is described, according to which all of the components are adjusted to corresponding densities. The products have a particularly durable simulated-rock appearance with good glitter characteristics.

Method of manufacturing high filler content plastics having a glitter

A transparent plastic pane for an aircraft canopy consisting essentially of a copolymer of methylmethacrylate and polyfunctional acrylates, wherein the content of methylmethacrylate is greater than about 95 wt. % and the content of polyfunctional acrylates is 0.5 to 5% of the copolymer, and which is obtained by cast polymerization, whereby the temperature for final polymerization is maintained at 110.degree. C. to 130.degree. C. for at least 5 hours.

Transparent plastic pane containing a copolymer of methylmethacrylate

A composition includes a polymethacrylimide polymer which is polymerized in the presence of an epoxy resin and a flame-inhibiting agent. Further, a process is described for making flame-resistant polymethacrylimide, which includes mixing an epoxy resin and a flame-inhibiting agent with a methacrylic acid and methacrylonitrile, and polymerizing. A polymethacrylimide foam so prepared has an LOI value of at least 25 and retains the good mechanical properties that are associated with polymethacrylimide foams.

Flame-resistant polymethacrylimide foams

A method for the casting of highly filled plastics containing polymethyl methacrylate, the method involving:

Method for the production of highly filled polymethyl methacrylate based

Suspensions for producing filled cast resins

Color concentrates comprising a colorant such as a pigment and a polymeric binder, and polymeric binders therefor, said polymeric binders comprising:

Acrylate resins as binders for color concentrates

Opaque tinted acrylic glass produced with organic pigments or with organic dyes, which in addition to the colorant, also contains an acid in the polymer matrix, exhibits improved resistance to weathering.

Tinted plexiglass with organic pigments

What is disclosed is an improved method for making substantially colorless polymethyl methacrylate by bulk polymerizing methyl methacrylate with an initiator which is an azo compound free of nitrile groups.

Method for bulk polymerizing methyl methacrylate

The present invention relates to a method of manufacturing molded polymer articles comprised of casting resins and having color-differentiated surface regions, wherein prior to the charging of the casting resin, a surface region of the molding implement is coated with a hardenable coating of a colorant-containing composition, producing color-differentiation in the surface of the molded articles. The designated surface regions of the molding implement are coated with at least two layers, whereby, according to the present method, the first coating step applies a filler-containing coating dispersion (L-1) without added colorant, and the second coating step applies a colorant-containing coating (L-2) without filler. Thereafter, the coating layers are dried, the casting resin is charged to the molding implement, the resin is polymerized by heating, and the molded articles removed from the mold.

Method of manufacturing molded polymer articles containing highly filled

The invention relates to electrically conducting solid plastics, the conductivity of which is attributable to their containing finely divided particulate, conducting substances. The electrically conducting solid plastics are comprised of or contain a polymer such as polymethyl methacrylate having a discrete fine-particle structure, and the polymer particles of the polymer are 'doped', at least on their surface, with at least one electrically conducting substance such as carbon black in an amount which establishes electrical conductivity. The conducting substance(s) are present in the form of a plurality of conducting particulate solid bodies, and wherein the condition is imposed that the glass temperature (Tg) of the polymer is not exceeded when the conducting substance is mixed with the polymer particles.

Electrically conducting solid plastics

Rigid foamed polymethacrylimide synthetic resin containing from 0.1 to 10 percent by weight of electrically conductive particles such as conductive carbon black exhibit improved properties when used in rapidly flowing streams of gases, are particularly suitable for use as a core material in laminates for aircraft construction, and are prepared by heating a copolymer of methacrylic acid and methyacrylonitrile containing a blowing agent and conductive particles.

Hard foam cores for laminates

Color concentrates comprising a colorant such as a pigment and a polymeric binder and polymeric binders therefor, said polymeric binders comprising:

The invention relates to a method of manufacturing plastic, electrically conductive pressure-formed plates from thermoplastic plastic particles which are mechanically formed. In this method, mechanically formed, thermoplastic particles each particle having maximum particle diameter in the range of about 1 mm to about 10 mm in the middle of said particle, are mechanically mixed with an amount of at least one electric-current-conducting substance sufficient to provide electrical conductivity. The electric-current-conducting substance is furnished in the form of a plurality of particulate, electrically conducting solid bodies, said mixing being effected in the temperature region below the glass temperature (Tg) of the thermoplastic plastic material of which the thermoplastic particles are comprised. The mixture thus produced is compressed to form plastic pressure-formed plates by means of a pressure-forming device.

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Darmstadt, Germany

Manfred Krieg