Hoechst Aktiengesellschaft

Ticona Gmbh

Hoechstaktiengesellschaft

Hoecht Ag

Ticora Gmbh

Helmut Scheckenbach

Andreas Schleicher

Georg Frank

Jurgen Kulpe

Axel Schonfeld

Dirk Zierer

Siegfried Weis

Bernd Jansen

Stefan Disch

Wolfgang Neumann

Michael Haubs

Klaus Delpy

Michael Bayer

Jorg Von Eysmondt

Martin Br&uuml;ck

Dirk Raudies

Axel Sch&ouml;nfeld

Gregor Buche

Michael Dierolf

The invention relates to a process for using nitric acid to oxidize polyarylene sulfide to polyarylene sulfoxide, oxidizing at least 98% of the sulfide groups of the polyarylene sulfide to sulfoxide groups. According to the invention polyarylene sulfide is treated with nitric acid at a concentration of from 60 to 80% with heating. The polyarylene sulfoxide prepared by the novel process can be used as an excellent chemical blowing agent for foaming thermoplastics.

Process for using nitric acid to oxidize polyarylene sulfide to polyarylene sulfoxide

Polyaryiene sulfone fiber material, especially web, is obtained by oxidizing polyarylene sulfide fiber material with a peracid/acid mixture of an organic acid at 60 to 100&deg; C. for 10 seconds to 45 minutes. Since this process provides a substantative degree of oxidation within a very short reaction time, one advantage of the process is that the rapidity of the oxidation renders continuous processes for oxidizing polyarylene sulfide fibers economical.

Rapid oxidation of polyarylene sulfide fiber material

Molding composition based on fluoropolymers and process for producing foam material therefrom

Polymer mixtures comprising at least one thermoset and at least one oxidized polyarylene sulfide have particularly good tribological behavior. Oxidized polyarylene sulfides used in these mixtures are polyarylene sulfones or oxidized polyarylene sulfides in which at least 10% of the sulfur bridges have been converted to sulfone bridges. Polyphenylene sulfone is employed with preference. The polymer mixtures are used to produce gearwheels, gear racks, bearings, chains, wheels or gasket materials.

Mixtures of thermosets and oxidized polyarylene sulfides

Polymeric coating systems comprising an oxidized polyarylene sulfide, especially polyarylene sulfone or partially oxidized polyarylene sulfide, are of improved abrasion resistance. The coating systems preferably comprise a polymer, a binder resin and oxidized polyarylene sulfide, and are suspended in a liquid vehicle. The coating systems are used for coating the surface of metallic and nonmetallic substrates.

Abrasion-resistant systems

Metallized moldings of polymer mixtures comprise a thermoplastic and a filler. The thermoplastic polymer has a melting point of more than 100.degree. C. and may be selected from the group consisting of fluoropolymers, polyamides, polycarbomates, polyesters, polyimides, liquid crystalline polymers, polymethyl methacrylates, polyphenylene oxides, polysulfones, polyurethanes and silicones. The filler may comprise oxidized polyarylene sulfide polyarylene sulfide, polyimide, aromatic polyester, or polyether ketone.

Metallizing thermoplastics

Polymer blends obtainable by thermal treatment, at not less than 150.degree. C., of a mixture containing at least one high-performance polymer and from 15 to 99 parts by weight or preferably from 40 to 90 parts by weight and particularly preferably from 55 to 75 parts by weight, of a polymer containing sulfoxide groups, and crosslinked or partly crosslinked polymer blend obtainable by thermal treatment, at not less than 150.degree. C., of a mixture containing at least one of the high-performance polymers polyesters, partly fluorinated polymers, polyethersulfones, polysulfones, polyetherimides, polyamidoimides or polyacetals and at least one polymer containing sulfoxide groups, are distinguished by high thermal and chemical stability. Polymers containing sulfoxide groups are polyarylene sulfoxides, in particular polyphenylene sulfoxide. The polymer blends are used for the production of fibers, films or shaped articles.

Polymer blends containing sulfoxide groups

A blend of at least one fluorine polymer, at least one oxidized polyarylene sulfide, at least one polyarylene sulfide and, if required, conventional additives results in a reduction in the expulsion of the oxidized polyarylene sulfides in gaseous form in the production of shaped articles from this blend, so that no cracks occur in the shaped article and problem-free processing by a cutting method is permitted.

Mixture of fluoropolymers, oxidized polyarylene sulfides and

A process for the preparation of polyarylene sulfoxides, in which polyarylene sulfide, suspends in a concentrated acid of formula R--SO.sub.3 H, in which R is a halogen atom Ian OH group, an aliphatic radical having 1 to 6 C atoms or an aromatic radcal having 6 to 18 C atoms, or of the formula R.sup.1 --CR.sup.2 R.sup.3 --COOH, in which R.sup.1 is a halogen atom and R.sup.2 and R.sup.3, independently of one another are each a halogen atom, an aliphatic radical having 1 to 50 atoms or a halogenated aliphatic radical having 1 to 5 C atoms, is oxidized by metering in a 30 to 85% strength hydrogen peroxide solution with thorough mixing and at a temperature of from -20 to +45.degree. C. According to this process, the sulfide units of the polyarylene sulfide are converted virtually selectively and completely into sulfoxide units.

Oxidation of polyarylene sulfides

A molding material which contains a sinterable polymer and a wax as a binder and advantageously an ethylene/vinyl acetate copolymer, an organic peroxide, an azoester and an alcohol can be injection molded to give a molding, dewaxed without loss of dimensional stability of the molding and then sintered.

Molding material for processing sinterable polymers

Mixtures of liquid-crystal polymers and polyarylene sulfoxides, foams

The invention relates to polyarylene sulfoxides which are soluble in polar organic solvents, a process for their preparation and their use. Soluble polyarylene sulfoxides can be prepared by homogeneous partial oxidation of polyarylene sulfides. The homogeneous partial oxidation is achieved by dispersing the polyarylene sulfide in finely divided form in a solvent stable to oxidation, slowly adding a mild oxidizing agent and terminating the oxidation as soon as the polymer chains have reached a uniform degree of oxidation. The partially oxidized polyarylene sulfoxides are suitable for the production of coatings and shaped articles, such as fibers, membranes, films and nonwovens.

Soluble polyarylene sulfoxides, a process for their preparation and

The process for the preparation of polyarylene sulfones by oxidation of polyarylene sulfides with an oxidizing agent in the presence of a liquid is carried out under reduced pressure so that the liquid boils. The reaction temperature can easily be kept constant in the process.

Process for the oxidation of polyarlene compounds containing thioether

An abrasion-resistant fluoropolymer mixture comprising

Abrasion-resistant fluoropolymer mixtures

A foamed polyarylene sulfide according to the invention has a density which is reduced by at least 50% compared with the theoretical density of nonfoamed material, and is expediently produced by subjecting a polyarylene sulfoxide as such or a mixture of one or more polyarylene sulfides with a polyarylene sulfoxide to heat treatment. The temperature of the heat treatment is in the range from 250.degree. to 400.degree. C.

Growing community of inventors

Langen, Germany

Helmut Scheckenbach