摘要:
The invention relates to thermoplastic molding compounds containing A) 10 to 99.99 wt % of a polyoxymethylene homopolymer or copolymer, B) 0.01 to 5 wt % of an imidazole of the general formula (I), wherein the groups R 1 to R 4 have the following meaning independently of each other: R 1 is an alkyl group having 1 to 5 C atoms, R 2 to R 4 are hydrogen, an alkyl group having 1 to 5 C atoms, C) 0 to 5 wt % of an alkaline-earth oxide, D) 0 to 80 wt % of further additives, wherein the total of the weight percentages of the components A) to D) is 100%.
摘要:
The invention relates to polyoxymethylene moulded bodies containing at least one polyoxymethylene homopolymer or copolymer A) and optionally other additives B), the surface of said polymer being coated with at least one binding agent C) and a formaldehyde scavenger D). The invention is characterised in that a polyalkylene oxide C1 or a polyvinyl ester C2 or a graft polymer C3 consisting of C1 and C2 or mixtures thereof is used as the binding agent C) and at least one imidazolidine-2-one compound is used as the formaldehyde scavenger D).
摘要:
The invention relates to a method for processing particulate raw polyoxymethylene, comprising the following steps: (a) adding the particulate raw polyoxymethylene to an extraction column (13), wherein the extraction column (13) is operated at a pressure in the range from 1 to 6 bar; (b) adding a polar extracting agent to the extraction column (13) at a temperature in the range from 95 to 140 °C and a pressure in the range from 1 to 6 bar, wherein 10 to 1000 ppm, in relation to the added quantity of polar extracting agent, of a buffer substance that buffers in the pH range from 7.5 to 11.5 is added to the extraction column.
摘要:
The invention relates to an initiator composition and method for anionic polymerisation, comprising at least one alkali metal hydride, selected from LiH, NaH and KH and at least one organoaluminium compound. The invention further relates to a method for anionic polymerisation of styrol or dienyl monomers using said initiator composition.
摘要:
The invention relates to a powder made of polyoxymethylene (POM) for use in a selective laser sintering process, comprising the following parameters: isothermal crystallization time (at 152 °C) > 3 min, Mn 22000 - 25000 g/mol, Mw 60000 - 140000 g/mol, Mw/Mn 3 - 5, MVR 15 - 70 [cm 3 /10 min], average particle size d50 60 μm, particle size 30 - 130 μm. The invention further relates to a method for the production thereof and molded parts produced using said powder by means of a selective laser sintering process.
摘要:
The invention relates to a method for producing polyoxymethylene by polymerizing a reaction mixture (R G ), which contains at least one formaldehyde source and at least one initiator mixture (I G ), wherein the initiator mixture (I G ) contains at least one polymerization initiator and at least one solvent of general formula (I), R 1 – O –[- R 3 – O -] m – R 2 (I), in which m is 1, 2, 3, or 4; R 1 and R 2 are C 3 to C 6 alkyl, independently of each other; R 3 is C 1 to C 5 alkylene.
摘要翻译:该专利申请涉及通过包含至少一种甲醛源和至少一种引发剂混合物(IG)的反应混合物(RG)的聚合制备聚甲醛的方法,其中引发剂混合物(IG)包含至少一种聚合引发剂和 至少一种通式(I)R 1 -O - [ - R 3 -O-] m -R 2(I)的溶剂,其中m为1,2,3或4; R 1和R 2各自独立地为C 3 -C 6 - 烷基; R3是C1-C5-亚烷基。
摘要:
The invention relates to polyoxymethylene moulded bodies containing at least one polyoxymethylene homopolymer or copolymer A) and optionally other additives B), the surface of said polymer being coated with at least one binding agent C) and a formaldehyde scavenger D). The invention is characterised in that a polyalkylene oxide C1 or a polyvinyl ester C2 or a graft polymer C3 consisting of C1 and C2 or mixtures thereof is used as the binding agent C) and at least one imidazolidine-2-one compound is used as the formaldehyde scavenger D).