摘要:
A filtration apparatus for removing undesirable components from a solution to be treated, comprises a module in which a number of hollow fibers are fixed at one end thereof by cast-molding materials, and is opened at the end portion above described and closed at another end portion thereof, in which said solution to be treated can be kept from leaking out of a mechanically sealed portion. Any defect in the sealed portion can be detected from the outside by the provision of an opening which leads the leaked solution to the outside of the apparatus, instead of allowing it to combine with the filtrate. The apparatus is preferably used for the manufacture of purified water which is free from bacteria, pyrogene, and the like. Ultra-purified water of remarkably high purity can be obtained when the apparatus is used as a check filter in a process for manufacturing ultra-purified water.
摘要:
Symmetrical and unsymmetrical ketones are produced from aldehydes (aliphatic, alicyclic or aromatic aldehydes) or their mixtures according to the process of the present invention which comprises contacting the aldehydes or mixtures theirof with a catalyst selected from the group consisting of zirconium oxide and combinations of zirconium oxide with an alkali metal oxide and/or an alkaline earth metal oxide. Said catalyst is used with or without a carrier. The process is operated in the vapor phase at elevated temperature in the presence or absence of steam.
摘要:
High impact resistant thermoplastic resins are produced in three steps: (a) graft polymerizing a minor amount of unsaturated monomer onto a major amount of diene type rubber polymer in latex form, (b) mixing the grafted diene type rubber latex with a monomer or monomers, extracting the grafted rubber polymer particles into the monomer phase and separating and discarding the water phase to obtain a grafted rubber polymer particle dispersed monomer solution, and (c) bulk polymerizing the resulting rubber polymer particle dispersed monomer solution.
摘要:
A composite hollow fiber type separation membrane which has three layers comprising a selective separation layer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer, said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;wherein said selective separation layer is formed on said ultra-microporous layer without penetrating into said ultra-microporous layer and has a non-porous, dense structure, the average thickness of said layer being 0.01-2.mu., and the coefficient of variation in thickness thereof being less than or equal to 25%;wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000 .times. scanning electron microscopy, but which has a fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08.mu.; andwherein said porous layer is a sponge structure comprising pores having a pore diameter of 0.1-1.mu. except for macro-voids and having a porosity of at least 50%, the thickness of said layer being 10-500.mu..
摘要:
A polyvinyl alcohol (PVA) microporous membrane is disclosed which is prepared by a process which comprises forming a PVA membrane containing fine silica particles therein and substantially extracting said silica particles from said membrane, thereby forming a plurality of micropores therein with an average diameter of 0.01 to 50 microns and a porosity of at least 60%.
摘要:
The polysulfone hollow fiber membrane of the invention has an inner dense skin layer composed of a polysulfone and a less amount of a polyvinylpyrrolidone, a content of the polyvinylpyrrolidone in the dense skin layer being higher than that in an outer surface layer. This membrane has excellent biocompatibility and antithrombogenetic ability and is, therefore, useful in body fluid treatment, such as hemodialysis, hemofiltration and hemoconcentration, without clogging with thrombi.
摘要:
A composite hollow fiber type separation membrane which has three layers comprising a selective separation layer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer, said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;wherein said selective separation layer is formed on said ultra-microporous layer without penetrating into said ultra-microporous layer and has a non-porous, dense structure, the average thickness of said layer being 0.01-2.mu., and the coefficient of variation in thickness thereof being less than or equal to 25%;wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000x scanning electron microscopy, but which has fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08.mu.; andwherein said porous layer is a sponge structure comprising pores having a pore diameter of 0.1-1.mu. except for micro-voids and having a porosity of at least 50%, the thickness of said layer being 10-500.mu..
摘要:
The polysulfone hollow fiber membrane provided by the present invention can prohibit bacteria, bacilli, viruses and the like, and is therefore useful, besides as an industrial filter for water purification, as a membrane for body fluid filtration or condensation. In particular, the polysulfone hollow fiber membrane is, being excellent in removing .beta..sub.2 -MG, markedly useful as a membrane for treating body fluid such as hemodialysis and hemofiltration.
摘要:
Ketones are prepared with a high yield and a prolonged catalyst life, by reacting an aldehyde selected from the group consisting of straight chain or branched chain aliphatic aldehydes having a carbon number of 4-10 (inclusive) and aromatic aldehydes represented by the general formula of ##SPC1##Wherein n is 0-5 with a monocarboxylic acid selected from the group consisting of acetic acid and propionic acid, at a temperature of 200.degree.-600.degree.C, in the presence of a catalyst of zirconium oxide alone or a mixture of zirconium oxide and at least one kind of the metal oxide selected from the group consisting of alkali metal oxides and alkaline earth metal oxides.
摘要:
A bulk polymerization reactor takes the form of a vertical, cylindrical vat of a jacket construction defining a reaction chamber which a rotary drive shaft having an off-center longitudinal section with perforated discs and shearing blades extends vertically through. Successful preclusion of abnormal stagnation of the liquid phase in the reaction chamber during polymerization avoids undesirable coloring in the product while assuring stable polymerization and high yield.