摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method for sinter coating a work-piece is disclosed, the work-piece having at least two sections of different surface-related heat capacities. The method includes a first step of pre-heating the work-piece to a first temperature that is higher than a fusion temperature of a sinter coating material. The method also includes a step of rapidly heating of the work-piece to a second temperature that is higher than the first temperature. However, the rapid heating step is halted before the temperature of the work-piece section with the greater surface-related heat capacity matches the second temperature. The work-piece then has a subsequent step of application of the sinter material to the work-piece. The step of shock heating of the work-piece is preceded by a step of pre-heating the work-piece under conditions which, with continuing effect on the work-piece, bring the work-piece under conditions which, with continuing effect on the work-piece, bring the work-piece to a second temperature between the fusion temperature of the sinter material and the first temperature.
摘要:
A process for the work-up of a reaction mixture formed by ammoximation of a ketone, in particular an alkanone or cycloalkanone, by means of hydrogen peroxide and ammonia in homogeneous solution over a titanium-containing catalyst. It comprises the substeps removal of the catalyst, selective separation of the oxime formed in the ammoximation from the reaction mixture, removal of water of reaction and recirculation of the solvent. The work-up is carried out using at least one membrane separation step and is also successful in the case of incomplete ketone conversion and in the presence of dissolved salts.
摘要:
A thermoplastic polymer powder composition containing a thermoplastic polymer or a powder blend of two or more thermoplastic polymers having an average particle diameter of from 40 to 250 μm, and from 0.01 to 10 parts of a metal powder.
摘要:
Oximes are prepared from ketones or aldehydes, hydrogen peroxide and ammonia. The reaction is carried out in a system of one aqueous phase and one phase of hydrocarbons inert under the reaction conditions in the presence of at least one interphase contactor and a catalyst system which consists of at least two components. A first component of the catalyst system is present in heterogeneous form and is based on titanium, silicon and oxygen and a second component is a homogeneously dissolved or suspended ammonium salt.
摘要:
The present invention relates to a process for working up an ammoximation reaction mixture, by separating a catalyst from the reaction mixture, removing the ketone oxime product, discharging the water of the reaction, and recirculating a solvent, where the ketone oxime formed is removed in a liquid phase with at least one liquid-liquid extraction in a ternary solvent system.
摘要:
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.
摘要:
A method for sinter coating a work-piece, the work-piece having at least two sections of different surface-related heat capacities. The method including a step of shock heating of the work-piece under conditions which, with continuing effect on the work-piece, bring the work-piece to a first temperature and which is stopped before the temperature of the work-piece section with the greater surface-related heat capacity matches the first temperature. The work-piece then has a subsequent step of application of the sinter material to the work-piece. The step of shock heating of the work-piece is preceded by a step of pre-heating the work-piece under conditions which, with continuing effect on the work-piece, bring the work-piece to a second temperature between the fusion temperature of the sinter material and the first temperature.