摘要:
A covering material comprising a first layer, which forms the wearing layer of the structure and contains an ionomer, as well as a second layer next to the first layer. According to the invention, the first layer contains a wear-resistant and electrically conductive ionomer polyelectrolyte and the second layer is electrically conductive. The first layer comprises in particularan ionomer, which is a polymer of a co- or terpolymer of ethylene and acrylic or methacrylic acid, or any other known ionomer, and a block polyether, the polymer being ionically crosslinked with alkali and/or alkaline-earth and/or metal cations. The second layer forms the bottom layer of the structure, and it is made up of a polyolefin elastomer that has been rendered electrically conductive. The material according to the invention is suitable as covering for ESD applications.
摘要:
Polyesters of organic hydroxy acids and their derivatives are, because of their ester linkages prone to hydrolysis, an important group of potentially biodegradable polymers. The mechanical properties of thermoplastic materials based on them have, however, been inferior for many applications, especially when melt processability is required. By the present method which comprises a two-step reaction and the use of a linking monomer it is possible to produce copolyester based polyurethanes from lactic acid and another organic hydroxy acid having a long flexible hydrocarbon chain in its molecules or corresponding lactone, as epsilon -caprolactone. By the proper choice of reaction parameters one can thus get materials which are unexpectedly strong, tough and/or elastic. By melt blending inherently brittle biodegradable polymers with a copolyester based polyurethane according to the invention it has been possible to prepare materials with significantly improved impact strength.
摘要:
This invention concerns a method for modifying a source material used in an ALD process, a method for depositing transition metal nitride thin films by an ALD process and apparatus for use in such process. According to the present invention transition metal source materials are reduced by vaporizing a metal source material, conducting the vaporized metal source material, into a reducing zone comprising a solid reducing agent maintained at an elevated temperature. Thereafter, the metal source material is contacted with the solid or liquid reducing agent in order to convert the source material into a reduced metal compound and reaction byproducts having a sufficiently high vapor pressure for transporting in gaseous form.
摘要:
The invention relates to a process and apparatus for the gasification of a carbonaceous material. According to the process, the carbonaceous material is gasified at an elevated temperature to produce gas, condensable compounds are separated from the gas, and the product gas thus obtained is recovered. According to the invention, in order to separate the condensable compounds the gas obtained from the gasifiers is directed to a dry scrubber (2) operating according to the fluidized bed priciple, wherein it is contacted with the bed material of the fluidized bed, the interior temperature of the dry scrubber being maintained lower than the condensation temperature of the condensable compounds in order to condense these compounds into the bed material. By means of the invention, a substantially tar-free gas can be produced which is suitable for the production of both heat and electricity.
摘要:
This invention relates to a PFC circuit for an uninterrupted power supply. Such a PFC circuit includes a first converter, a second converter, an energy storing branch composed of two capacitors in series, and a controller. Each of the first and the second converters has an input terminal and two output terminals. The input terminal is connected with the AC live wire of the commercial power, while the two output terminals of each converter are connected in parallel with the two ends of the energy storing branch, with the parallel joints acting as the output terminal of the positive and the negative voltages respectively. The common nod of the two capacitors in series serves as the common output terminal of the positive and the negative voltages, and it is connected with the neutral of the commercial power. By controlling the switch transistors of the first and the second converters, the controller allows the first and the second converters to output the positive and the negative DC voltages respectively, and brings the phase and the waveform of the input voltage of the commercial power and the current to be consistent with each other. The PFC circuit of the invention can be easily connected with a single battery or two batteries. It is capable of realizing AC-to-DC conversion, DC-to-AC conversion and power factor correction, and it is particularly suitable for using in the online UPS.
摘要:
A method for manufacturing a board product made up of at least two layers, and a multilayer board product. According to the method, the board webs (4, 5, 6) forming the layers are bonded together by gluing. According to the invention, at least one of the webs is treated mechanically by compression so that in the web surface there form permanent deformations projecting from the web surface, and the layers are glued together by using a starch-based adhesive, which is applied at a solids content over 45 % to the layers to be bonded. The adhesive having a high solids content dries and bonds rapidly to the surfaces to be joined, even without additional heating. Since the adhesive contains little or no water, no after-bending or flattening of the middle layer occurs in the bond.
摘要:
The invention relates to novel transglycosylation products and their preparation. The transglycosylation products according to the invention are prepared from starch derivatives, such as esters or ethers of starch. The products are obtained by reacting a starch derivative with an alcohol in the presence of an acid catalyst. The forming product is separated by precipitation or by removing any unreacted alcohol by evaporation. In the products according to the invention the good properties of starch derivatives, such as the excellent water resistance of esters, are combined with the versatility of transglycoside products. The products can be used as adhesives, in which case they are formulated, for example as hot-melt adhesives, and as comonomers, prepolymers or macroinitiators in the preparation of polymers.