Firma Carl Freudenberg

Dr. Alois Stankiewicz Gmbh

Ernst Lohmar

Gerhard Burak

Thomas Stankiewicz

Hans-Achim Kunkel

Wolffried Wenneis

Karl-Heinz Krummel

A polyvinyl chloride-free plastisol comprises

Polyvinyl chloride-free plastisol and its use

The present invention relates to polyurethane foam materials with sound insulating and vibration damping properties. They are obtainable by reacting a polyisocyanate or polyisocyanate prepolymers with an excess of polyols or a mixture thereof while maintaining an NCO index of .ltoreq.80, in particular .ltoreq.70 and as a result they have an adhesive (frictional) surface and are further characterized by a density of 80 to 250 kg/m.sup.3, a modulus of elasticity less than 300 OOO N/m.sup.2 and a loss factor of at least 0.4. The production is preferably done by adding the reaction components (polyol system on the one hand and polyisocyanate system on the other) to the mixture head of an RIM machine. The polyurethane soft foam materials with an adhesive surface according to the invention are particularly suitable for use as vibration damping sound insulation systems in automobiles.

Polyurethane soft foam with sound insulating and vibration damping

Disclosed herein is a process for producing cross-linked polypropylene by subjecting a homogenous mixture of a polypropylene with from about 2 to about 20 weight percent, based upon the weight of the polypropylene, of polybutadiene with a molecular weight of from about 500 to about 10,000 to conditions sufficient to effect cross-linking, for example, through the use of cross-linking agents and/or irradiation. In addition, the process disclosed herein may be utilized to produce cross-linked and foamed polypropylenes.

Method for the manufacture of cross-linked and optionally foamed

An interior lining for a motor vehicle is made from a foam layer of a cross-linked, closed-cell-foamed polypropylene laminated to a deep-drawable polyolefin sheet or a non-woven or woven fabric or laminated to both. The volumetric weight of the foam layer is 30 to 200 kg per cubic m. and provides dimensional and shape stability to the lining up to temperatures of about 120.degree. C.

Interior lining for motor vehicles

This application is directed to light-weight and hard foam materials. The foams of this invention are prepared by extruding thermoplastic crystalline plastics in the presence of highly volatile organic liquids as the foaming agents. In accordance with the present method crystalline polyolefins, in the presence of polybutadiene, ethylenevinylacetate copolymers, ethylene-propylenes and/or ethylene-propylene terpolymer rubbers, and optionally radical formers such as suitable peroxides, azidene, sulfonyl azidene or the like, and inhibitors for radical decomposition, such as triallylcyanurate or an acrylate selected from the group consisting of trimethylolpropane-trimethacrylate, allyl-methacrylate, tetrahydrofurfurylmethacrylate, triethyleneglycol-dimethacrylate, polyethyleneglycol-dimethacrylate or the like, are converted into foam-like molded bodies by means of a highly volatile organic liquid foaming agent. The foaming agent is employed in an amount of from about 5 to about 30% by weight, based on the weight of the polyolefins. The foaming agent and the polyolefins are mixed in an extruder at a temperature of from about 180.degree. to about 280.degree. C., and at a pressure which is greater than the vapor pressure of the foaming agent. The mixture is subsequently extruded.

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Weinheim, Germany

Ernst Lohmar