A sintering powder containing polyamide polymer and titanium dioxide particles, a process for laser sintering, and moldings produced from the sintering powder. The moldings formed using the powder of the invention have improved surface quality due to the powders having increased yellowing resistance when exposed to thermal stress during laser sintering. Moldings produced from the sintering powder have improved mechanical properties, in particular modulus of elasticity.

Laser-sintering powder containing titanium dioxide particles, process for its preparation, and moldings produced therefrom

The present invention relates to a powder comprising polyarylene ether ketone (PAEK), to the use of this powder in processes whose operation is based on pulverulent materials and in which the desired structures are produced layer-by-layer via selective melting and hardening, and also to moldings produced from this powder by this process. The moldings constructed using the powder by the process, when compared with moldings produced by conventional laser-sintering processes, exhibit marked advantages in relation to their heat resistance and their mechanical properties. This can open up new applications by means of rapid prototyping/rapid manufacturing (RP/RM) processes, for example in the engine compartment of a car.

Use of polyarylene ether ketone powder in a three-dimensional powder-based moldless production process, and moldings produced therefrom

A composition containing from 88 to 99.99% by weight of a polyamide, a compound of a polyamide and mixtures of these, and from 0.01 to 0.25% by weight of a flow aid where the drying loss from the flow aid after 5 days of conditioning at a relative humidity of 95% is less than or equal to 1%, determined by ISO 787/2.

Polyamide powder with long-lasting, consistently good flowability

The epoxidation of cyclic, at least monounsaturated alkenes is conducted by a process, which comprises conducting the epoxidation of a cyclic, at least monounsaturated alkene in the presence of an oxidant in a reaction medium that contains at least 1% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene. In a preferred embodiment the reaction medium contains at least 2.5% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene.

Process for the epoxidation of cyclic alkenes

The present invention relates to polyamide powders suitable for cosmetic applications are described which have a pH of 4.0 to 7.0, cosmetic compositions containing the polyamide powders and processes of making the same.

Ph-regulated polyamide powder for cosmetic applications

The selective epoxidation of cis double bonds of macrocyclic aliphatic hydrocarbons having 8 to 20 ring carbon atoms occurs by a catalytic process. The macrocyclic aliphatic hydrocarbons may optionally contain one or more side chains and in which at least one further trans double bond is simultaneously present. The used catalyst system consists of a cationic phase-transfer catalyst and an anionic polyoxometallate which is a polytungstate or a polymolybdate. Additionally, it comprises one or more elements selected from germanium, tin, lead, arsenic, antimony, bismuth, selenium, tellurium and polonium, and optionally one or more transition metals from group 4 to 12 of the Periodic Table.

Process for the epoxidation of CIS double bonds

A description is given of a process for the isolation of high-boiling monomers from the distillation residue formed in the cyclodimerization and cyclotrimerization of 1,3-butadiene and separation of the target products, wherein - the low boilers are separated off, - the desired target products cyclooctadiene or cyclododecatriene are isolated by distillation, - the distillation residue is extracted with a nonpolar or slightly polar solvent or solvent mixture, - insoluble oligomers and polymers crystallize at least partly and are separated off by a mechanical separation operation, - the extractant is preferably removed as low boiler by distillation and - the high-boiling monomers are preferably isolated by vacuum distillation.

Process for the isolation of high boilers from the cyclooligomerization of 1,3-butadiene

PROBLEM TO BE SOLVED: To provide a method for selectively epoxidizing one cis-double bond in a macrocyclic olefin. SOLUTION: This method comprises a catalytic selective epoxidation of a cis-double bond in a macrocyclic aliphatic hydrocarbon having 8-20 cyclic carbon atoms and having at least one trans-double bond and optionally at least one side chain; wherein the catalytic system comprises a phase-transfer catalyst and a polyoxometalate which consists of a tungsten- or molybdenum-based polyoxometalate and contains at least another group 14-16 element, and optionally contains at least one group 4-12 transition metal atom.

Method for producing macrocyclic monoepoxide having at least one double bond

Production of macrocyclic monoepoxides containing at least one double bond, involves addition of a macrocyclic aliphatic hydrocarbon to hydrogen peroxide in the presence of a homogeneous catalyst system comprising an oxidation catalyst, preferably polyoxometallate of tungsten or molybdenum and a Group 14-16 element with a phase transfer catalyst. A process for the production of macrocyclic monoepoxides (I) containing at least one double bond, prepared from a macrocyclic aliphatic hydrocarbon, having at least one cis double bond and the presence of at least one other trans double bond, by addition of hydrogen peroxide in the presence of a catalyst, comprises processing in two liquid phases and use of a homogeneous catalyst system comprising an oxidation catalyst and a phase transfer catalyst whereby the oxidation catalyst is a polyoxometallate of tungsten or molybdenum and a Group 14-16 element, preferably germanium, tin, lead, arsenic, antimony, bismuth, selenium, tellurium or polonium.

Georg Oenbrink

Papers

Process for the epoxidation of CIS double bonds

Process for the isolation of high boilers from the cyclooligomerization of 1,3-butadiene

Method for producing macrocyclic monoepoxide having at least one double bond

Epoxidation process of cis-double bonds