Roehm Gmbh & Co Kg

Roehm Gmbh Chemische Fabrik

Evonik Rohm Gmbh

Hermann Seibert

Werner Geyer

Leonhard Maier

Thomas Barthel

Sabine Servaty

Torsten Jahn

Peter Stein

Leonard Maier

Rainer Zimmermann

Wilfried Heberer

Dirk Roosen

The invention relates to compositions for producing polymethacrylimide foams having reduced pore size. The inventive method allows production of a microporous foam with an especially homogeneous pore size distribution without having to use insoluble nucleation agents.

Thermostable microporous polymethacrylimide foams

The invention relates to an improved method for producing foamed material, especially poly(meth)acrylimide foams, which are foamed from polymer plates produced according to the casting method. The two-step method consists of a pre-heating step and at least one foaming step. The product obtained has a significantly smaller compressive strain, measured according to DIN 53425(ASMD 621), than prior art products.

Method for producing polymethacrylimide foams

A diaphragm for an electroacoustic transducer has a) a core layer containing poly(meth)acrylimide foam and b) at least one cover layer. The diaphragm is produced by laminating the cover layer with the core layer, using a pressure of 0.4 MPa and a temperature of 160&deg; C., whereby at least the side of the core layer which comes into contact with the cover layer is compressed. The resultant composite is subsequently cooled to a temperature below 80&deg; C., before the pressure is reduced to the ambient pressure. The process can be carried out as a single-step process. The diaphragms produced by this process demonstrate an excellent stability, whereby the cover layers in particular are highly resistant to separation.

Process for a diaphragm for electroacoustic transducers

Polymethacrylimide foams are prepared by a method, comprising: preparing a mixture consisting of

Process for the production of polymethacrylimide foam materials

The present invention relates to combined insulation layers (ISS), preferably for use in shipbuilding, encompassing (i) an outer layer (AS) consisting of sheet metal, combined with (ii) a melamine layer (MSS), (iii) a sheet aluminum layer, (iv) a core layer of a hard foam material (HSS), coated on both sides with a phenolic resin prepreg (PNP).

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Darmstadt, Germany

Hermann Seibert