Basf Aktiengesellschaft

Isidoor De Grave

Klaus Hahn

Joachim Fischer

Hermann Tatzel

Rupert Schick

Wolfram Koegel

Adolf Echte

Frank Braun

Wolfram Kogel

Paul Wittmer

Guiscard Gl&uuml;ck

Onno Graalmann

Jens Rieger

Hans Peter Rath

Juergen Kerth

Manfred Walter

Franz-Josef Dietzen

Gerd Ehrmann

Rainer Alexander Werner

Uwe Witt

Udo Haardt

Heinz Krapf

Jurgen Schweinzer

Fritz E Krueckau

Manfred Leibach

Wolfram K&ouml;gel

The invention relates to expanded polypropylene beads having a density of from 5 to 200 g/l and a bead diameter of from 1 to 10 mm which comprise from 0.002 to 20% by weight of graphite particles.

Expanded polypropylene particles

Biodegradable polyester material particles

A process comprises producing expanded polyolefin particles by impregnating polyolefin granules with a volatile blowing agent in suspension under pressure, and then releasing the pressure. The suspension medium has a lower density than the polyolefin granules and the suspension is practically free from suspension agents.

Method for producing expanded polyolefin particles

The invention relates to sound-absorbent foam moldings which have a sound-absorption level according to DIN 52215 of from 30 to 95% in the frequency range from 0.5 to 4 kHz. The foam is an incompletely fused molded polyolefin or polystyrene foam with from 10 to 40% interstitial volume.

Sound-absorbent foam moldings

Production of expanded polyolefin particles

In a process for producing polyolefin foam particles, partially foamed particles are produced in a first stage by extrusion of a polyolefin containing solid blowing agents, and these are then further foamed in the second stage using steam.

Polyolefin particle foam

Prefoamed polyolefin beads produced by extrusion

Production of expanded polyolefin beads

Polyolefin foams having a density of from 0.01 to 0.1 g/cm.sup.3 and having 2 to 1000 cells/mm.sup.2 and containing a resin acid, a lower alkyl ester of a resin acid or (hydro) abietyl phthalate as organic foaming aid have a homogeneous cell structure.

Polyolefin foams having a homogeneous cell structure

Polyolefin foams having a density of from 0.01 to 0.1 g/cm.sup.3 and having 2 to 1000 cells/mm.sup.2 and containing a resin acid, a lower alkyl ester or a resin acid or (hydro) abietyl phthalate as organic foaming aid have a homogeneous cell structure.

In foams having a density of from 0.01 to 0.2 g/cm.sup.3 and a cell count of from 2 to 1,000 cells/mm.sup.2 and based on an impact copolymer, the impact copolymer consists of

Foam based on an impact copolymer

Novel foams having a density of from 0.01 to 0.1 g/cm.sup.3, based on a copolymer comprising ethylene, propylene and a C.sub.4 - to C.sub.8 -.alpha.-olefin, and having a torsion modulus of from 100 to 800 N/mm.sup.2 have high tensile, compressive and flexural strengths and at the same time high elongation at break.

Foams based on an olefin copolymer

Foam particles of propylene polymers which have shrunk from 40 to 95% of their original volume and have a bulk density of from 10 to 30 g/1 can be expanded if they are treated with air or nitrogen under superatmospheric pressure, subsequently decompressed. If desired post-foamed by heating and, after aging, re-treated with air or nitrogen under superatmospheric pressure, subsequently decompressed and aged under atmospheric pressure until the pressure in the cells has dissipated.

Expansion of shrunk foam particles of propylene polymers

Expandable styrene polymers and styrene polymer foams having a particularly uniform and fine-cell foam structure contain, as a cell regulator, small amounts of a mixture of resin acids, lower alkyl esters of resin acids or (hydro)abietyl phthalate and a polyoxyethylene monoester or monoether.

Expandable styrene polymers and styrene polymer foams

Particulate polystyrene containing blowing agent and having improved expandability is based on polystyrene having a weight-average mean molecular weight of not more than from 130,000 to 180,000 and a molecular weight distribution curve in which the high molecular weight flank drops steeply. The expandable polystyrene particles are produced by polymerizing styrene in aqueous suspension in the presence of blowing agents and of chain transfer agents or styrene oligomers.

Growing community of inventors

Wachenheim, Germany

Isidoor De Grave