摘要:
Fine particles of polyvinyl chloride produced by bulk polymerization which comprise substantially discrete spherical particles with particle sizes of 0.2 to 2 microns, a plastisol prepared by adding 80 parts by weight of dioctylphthalate to 100 parts by weight of said particles having a viscosity of 50,000 centipoise or less (measured by a B-type viscometer, No. 4 rotor, 12 rpm, 25.degree. C.) and a process for producing the same which comprises subjecting vinyl chloride to bulk polymerization in the presence of a dispersing stabilizer under gentle stirring without causing sedimentation or agglomeration of the polymer particles formed, wherein polymerization is terminated at a polymerization yield of 5 to 30%.
摘要:
Light-transmitting compositions containing (1) 50-99% by weight of polyvinylidene fluoride or a vinylidene fluoride copolymer and (2) 1-50% by weight of a copolymer of a vinyl fluoride monomer and at least one acrylate monomer selected from the group consisting of alkyl acrylates and alkyl methacrylates wherein the alkyl group contains from one to four carbon atoms.
摘要:
A synthetic resin for use in adhering polyvinylidene fluoride and polyvinyl chloride, the thus prepared composite material comprising polyvinylidene fluoride, the synthetic resin as an adhesive and polyvinyl chloride, and the methods for preparing the synthetic resin and the composite material are described as well as the composite material.
摘要:
This invention provides PVDF having such crystallization properties as to produce small spherulite sizes without sacrifices to properties, processability, purity, etc., and a suspension polymerization method to obtain the same.The PVDF obtained by this invention comprises the monomer unit content of 99.5-96 wt. % of vinylidene fluoride, and the monomer unit content of 0.5-4 wt. % of comonomers selected from hexafluoropropylene and/or tetrafluoroethylene, and has a logarithmic viscosity of 0.9-1.3 dl/g, and a molecular-weight distribution, as expressed in the ratio (Mw/Mn) of weight-average molecular weight and number-average molecular weight, of 2.2-2.8.In order to manufacture the PVDF of this invention, a mixture of vinylidene fluoride monomers containing 1-5 wt. % of monomers selected from hexafluoropropylene and/or tetrafluoroethylene is suspension-polymerized in an aqueous medium, using an oil-soluble initiator so that the logarithmic viscosity [.eta..sub.1 ] is kept at 1.3-1.9 dl/g until the polymerization conversion rate of vinylidene fluoride monomers becomes 10-50%, and the polymerization is continued by adding a chain transfer agent at that polymerization conversion rate so that the logarithmic viscosity [.eta..sub.2 ] of the eventually obtained polymers becomes 0.3-0.7 dl/g lower than [.eta..sub.1 ], and yet remains in the range of 0.9-1.3 dl/g.
摘要:
Polyvinylidene fluoride (PVDF) having such crystallization properties as to produce small spheralite sizes without sacrificing properties, processability, purity, etc. comprises 99.5-96 wt. % of vinylidene fluoride and 0.5-4 wt. % of a comonomer selected from the group consisting of hexafluoropropylene, tetrafluoroethylene and mixtures thereof, has a logarithmic viscosity of 0.9-1.3 dl/g and a molecular weight distribution, as expressed by the ratio of weight average molecular weight to number average molecular weight, of 2.2-2.8. The PVDF is formed by suspension polymerizing vinylidene fluoride and 1-5 wt. % of the desired comonomer, in an aqueous medium in the presence of an oil-soluble initiator, so that a logarithmic viscosity [.eta..sub.1 ] of 1.3-1.9 dl/g is obtained at a vinylidene fluoride conversion of 10-50%; then adding a chain transfer agent to the medium and continuing polymerization so that the logarithmic viscosity [.eta..sub.2 ] of the final polymer is 0.3-0.7 dl/g lower than [.eta..sub.1 ] but remains in the range of 0.9-1.3 dl/g.
摘要:
A vinylidene fluoride copolymer containing a carboxyl group or a carbonate group is formed by copolymerizing a monomer principally comprising vinylidene fluoride with a relatively small amount of an unsaturated dibasic acid monoester or vinylene carbonate. The copolymer has a large adhesion to various substrates or fillers and is excellent in chemical resistance, so that it is useful as a basic substance constituting a binder, an adhesive, a paint, etc. The copolymer is particularly effectively used as a binder for constituting an electrode for a non-aqueous solvent-type secondary battery together with an active substance, or an active substance and an electroconductive material, respectively in a particulate form.
摘要:
The object of the present invention is to provide the use of glycyrrhizin and its derivatives for inhibition of MCP-1 production. The present invention discloses an MCP-1 production inhibition method and pharmaceutical composition for the same comprising administration of glycyrrhizin and its derivatives in an amount effective for said inhibition to mammals in which migration of monocytes or T lymphocytes is increased, or production of IL-10 is increased, and inhibition of said increase is desired, thereby treating or preventing decreases in infection resistance.
摘要:
Temperature control is made without the risk of contaminating object-to-be-processed and with high accuracy. Temperatures are metered out of contact with the objects-to-be-processed, and based on a metered result, estimated temperatures of the objects-to-be-processed are computed. Furthermore, estimation errors of the estimated temperatures are computed to correct the estimated temperatures. Based on a temperature recipe stating relationships between set temperatures and times and the corrected estimated temperatures, a heater is controlled.
摘要:
A second vertical heat treating apparatus is temperature-calibrated based on a heat treatment result obtained by a first vertical heat treating apparatus for reference. First, temperature measurement wafers is heated in the first apparatus to obtain set values of temperature controllers for a target value of temperature. Then, wafers are subjected to an oxidizing process in the first apparatus by using these set values to form an oxide film. The thickness of the oxide film is measured and recorded as a reference film thickness. Then, wafers are subjected to an oxidizing process in a second apparatus at temperatures near the target value to form an oxide film. The thickness of the oxide film is measured, and difference in thickness between the oxide film formed in the second apparatus and the reference film thickness is obtained. The oxidizing process in the second apparatus is repeated to obtain set values of temperature controllers for the second apparatus at the time when the difference in film thickness becomes zero. The second apparatus is temperature-calibrated on the basis of the set value thus obtained.
摘要:
A vinylidene fluoride copolymer having a relatively high molecular weight is formed by copolymerizing (a) vinylidene fluoride as a principal component, (b) a small amount of epoxy group-containing monomer, and (c) an optional component, such as an unsaturated dibasic acid monoester functioning as a curing agent for the epoxy group. When cured with an optional epoxy curing agent, the vinylidene fluoride copolymer provides a cured product having an adhesion with a metal substrate, etc., and also showing excellent solvent resistance and chemical resistance. The vinylidene fluoride copolymer is particularly suitable for constituting a binder for producing an electrode for a non-aqueous solvent-type secondary battery.