摘要:
This invention relates to processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides, preferably substantially linear polyarylene sulfides and, more preferably, substantially linear poly-p-phenylene sulfide by melt spinning, multistage stretching and optionally crimping and setting.As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C. (preferably in stretching baths, more particularly in boiling water), the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching (in hot air) at elevated temperature. The residence times in the first stage required for effective stretching in accordance with the invention can only be varied within relatively narrow limits in order subsequently to achieve the calculated orientations and effects, particularly high strengths, crystallinities and densities. Overly long residence times at temperatures above 100.degree. C. result in elongation of the material with no additional orientation and hence with an inadequate increase in strength.To increase crystallinity and strength in the production of mono- and multifilaments, multistage stretching may be followed by a thermal aftertreatment; in the staple fiber process, the material is additionally crimped, set (in the absence of tension) and cut. Where an aerodynamic crimping nozzle is used, as is preferably the case, stretching has to be carried out in accordance with the invention in such a way that the fibers are left with sufficiently high shrinkage which is important for crimping and subsequent processing. Crimping is improved by setting in the absence of tension. Relatively high-tensile fibers with sufficiently high residual crimping for subsequent processing are obtained.Textile-denier fibers (up to about 20 dtex) having hitherto unknown strengths of >6 cN/dtex, preferably >6.2 cN/dtex and, more preferably, >6.4 cN/dtex are claimed.
摘要:
Processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides by melt spinning, multistage stretching and setting. As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C., the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching at elevated temperature. The residence times in the first stage required for effective stretching can only be varied within relatively narrow limits in order subsequently to achieve the calculated orientations and effects. Overly long residence times at temperatures above 100.degree. C. result in elongation of the material with no additional orientation and hence with an inadequate increase in strength.
摘要:
A composition suitable for paper brightening, wherein the composition contains one or more specified fluorescent whitening agents with taurine groups. The composition is used for whitening paper, in particular at the wet-end, in the size press or by coating.
摘要:
Disulfo-type fluorescent whitening agents for optically brightening coating slips contain a synthetic binder and a different synthetic co-binder. In addition, a coating slip and its use for preparing coated papers are disclosed.
摘要:
The invention relates to a composition suitable for paper brightening, wherein the composition contains one or more specified fluorescent whitening agents with taurine groups. The composition is used for whitening paper, in particular at the wet-end, in the size press or by coating.
摘要:
The invention relates to catalysts for the methanation of carbon monoxide, which comprise metal-doped nickel oxide of the composition (in mol %) (M1)a(M2)bNicOxwhere a=0.1 to 5 mol %, b=3 to 20 mol % and c=100−(a+b) mol % and M1 comprises at least one metal of transition group VII or VIII of the PTE (=Periodic Table of the Elements) and M2 comprises at least one metal of transition group III or IV of the PTE. The catalysts can be used as pure catalysts or as supported catalysts, if appropriate applied as coatings to an inert support body. They display high conversion and high selectivity and are used in methanation processes of CO in hydrogen-containing gas mixtures, in particular in reformates for operation of fuel cells. The catalysts of the invention can be prepared by precipitation, impregnation, sol-gel methods, sintering processes or by powder synthesis.
摘要:
Process for the production of a metal oxide powder having a BET surface area of at least 20 m2/g by reacting an aerosol with oxygen in a reaction space at a reaction temperature of more than 700° C. and then separating the resulting powder from gaseous substances in the reaction space, wherein the aerosol is obtained by atomisation using a multi-component nozzle of at least one starting material, as such in liquid form or in solution, and at least one atomising gas, the volume-related mean drop diameter D30 of the aerosol is from 30 to 100 μm and the number of aerosol drops larger than 100 μm is up to 10%, based on the total number of drops, and metal oxide powder obtainable by this process.
摘要:
The invention relates to a hydraulic valve (1), which comprises an electromagnet (2) with a magnet armature (3) as well as the valve part (4) with at least two valve seats (5, 6). The electromagnet (2) is formed by a hollow-cylindrical plastic coil former (8), a coil winding (10) which is accommodated in the latter and a magnet housing (11) which encloses the coil winding (10), the hollow cylinder of the coil former (8) being formed as an armature space (14) of the magnet armature (3), into which an upper magnet pole (15) and a lower magnet pole (16) protrude. The valve part (4) is formed by a hollow-cylindrical valve housing (18), which has a pressure connection (P) at the end as well as a consumer connection (A) and a tank connection (T), respectively arranged in its lateral surface (19), in the hollow cylinder of which housing two cup-shaped deep-drawn parts (23, 24) with the valve seats (5, 6) are pressed. The hydraulic valve (1) can be inserted into a complementary valve receptacle by the valve part (4) and has a fastening flange (26), by means of which it can be screwed on the valve receptacle in a manner sealing the pressure medium. According to the invention, at least the magnet housing (11) and the lower magnet pole (16) of the electromagnet (2) and/or the valve housing (18) and the fastening flange (26) of the hydraulic valve (1) are respectively formed as one-part integral components and as individual parts which can be produced without machining.
摘要:
The invention relates to a composition suitable for surface treatment of paper, wherein the composition contains a specified fluorescent whitening agent with alkylsulfonic acid groups, a salt of a bivalent cation, and a carrier. The composition is used for whitening paper, in particular in the size press.
摘要:
An aggregated crystalline silicon powder with a BET surface area of 20 to 150 m2/g is provided. The aggregated crystalline silicon may be doped with a doping component and can be used to produce electronic components.