Abstract: There are provided a pressure intensifying cylinder 2a for allowing a pressure intensifying chamber 31 to communicate with a head-side cylinder chamber 22 of a working cylinder 1 and its control hydraulic circuit. When a load and a rated pressure Pp of a hydraulic pump 25 are balanced with each other at the time of inserting and setting a core 41, a check valve 21 is closed and a sequence valve 34 is opened to move the pressure intensifying cylinder 2a forward, so that the pressure of the head-side cylinder chamber 22 is increased. A pressure intensifying ratio of the pressure intensifying cylinder 2a is set such that the pressure of the head-side cylinder chamber 22 is higher than pressure occurring with molding pressure.

Abstract: To provide the stabilization method, in which unstable groups of melt-processable fluorine-containing polymer having unstable groups can be stabilized rapidly and effectively, and even if the obtained stabilized polymer is melt-molded, an obtained molded article is free from bubbles and cavity and no coloration arises. The method of stabilizing a fluorine-containing polymer by melt-kneading a melt-processable fluorine-containing polymer having unstable groups in a kneader having a stabilization treatment zone which satisfies the following conditions: (1) an oxygen-containing gas is present in the stabilization treatment zone, (2) water is present in the stabilization treatment zone, and (3) an absolute pressure in the stabilization treatment zone is adjusted to a pressure of 0.

Abstract: A melt-processable fluorine-containing polymer is melt kneaded with a kneader which has a residence time of at least 10 minutes, a usable volume ratio (usable space in a container/space in a container) of larger than 0.3, and a power factor K of less than 8000, the power factor K being represented by the formula: K=Pv/&mgr;/n2 in which Pv is a power requirement per unit volume (W/m3), &mgr; is a melt viscosity (Pa.s), and n is a rotation speed (rps), to effectively remove terminal groups and bonds in the backbones, which are unstable during melt kneading, from the melt-processable fluorine-containing polymer, and obtain a colorless fluorine-containing polymer.

Abstract: A process for preparing a fluoropolymer by the batchwise polymerization of a monomer mixture containing tetrafluoroethylene, in which, after the initiation of a reaction, the monomers are reacted under conditions such that the monomer mixture is supplemented to a polymerization system in an amount more than the amount of the monomers consumed and simultaneously the excessive unreacted monomers are discharged from the polymerization system to maintain the monomer composition in the polymerization system substantially the same as that of the composition of the monomer mixture initially charged, and the monomer mixture supplemented to the polymerization system contains a compound suppressing the autoexplosion of the monomers.

Abstract: This invention aims to prevent a core from being pushed back when a hydraulic fluid is compressed by a high load occurring with a molding pressure of molten melt at a casting and pressing time in a core driving cylinder in a die cast machine.

Abstract: To positively prevent a pressure medium sealed into an outer tube from leaking out from a clearance relative to an oil damper, there is provided a seal construction of a shock absorber 1 with leveling function wherein a seal mechanism 3 is disposed in an outer tube 2 to slidably insert a shock absorber 4 thereinto, a piston rod 5 extending from the shock absorber 4 is connected on the outer tube 2 side, a pressure medium sealed into the outer tube 2 is heated by a heating means 7 and leveling is carried out while controlling the support force exerting on the shock absorber 4, the seal construction being constituted that a free piston 15 is interposed opposite to the seal mechanism 3 between the outer tube 2 and the shock absorber 4, and the seal mechanism 3 and the free piston 15 compart and form a lubricating oil chamber 16 therebetween whereas the free piston 15 is always biased toward the lubricating oil chamber 16.

Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.

Abstract: A process for preparing a fluoropolymer by the batchwise polymerization of a monomer mixture containing tetrafluoroethylene, in which, after the initiation of a reaction, the monomers are reacted under conditions such that the monomer mixture is supplemented to a polymerization system in an amount more than the amount of the monomers consumed and simultaneously the excessive unreacted monomers are discharged from the polymerization system to maintain the monomer composition in the polymerization system substantially the same as that of the composition of the monomer mixture initially charged, and the monomer mixture supplemented to the polymerization system contains a compound suppressing the autoexplosion of the monomers.

Abstract: Coagulated particles having a low water content are separated and recovered from an emulsified dispersion of fluorine-containing polymer particles. A solid-liquid separation method comprising: a step for adding a coagulant in an emulsified dispersion of fluorine-containing polymer particles to coagulate the fluorine-containing polymer particles with stirring and obtain a slurry of coagulated particles, a step for filtrating the slurry, and a step for pressing the obtained cake. It is preferable to continuously carry out the filtration step and pressing step with a filter press or a belt press. Also a washing step may be provided after the filtration step.

Abstract: A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perchloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF3CHCl2) and/or HCFC-124 (CF3CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst.

Abstract: A polymerization process, in which when at least one of fluorine-containing olefin monomers in gaseous phase or supercritical phase or a monomer mixture of the fluorine-containing olefin monomer and other monomer copolymerizable therewith is subjected to batch polymerization in an aqueous medium while being diffused to the aqueous medium, a diffusing amount of the monomer or monomer mixture to the aqueous medium is not less than 80% of the theoretical consumption of the monomer or monomer mixture when polymerized at the theoretical polymerization rate. According to the present invention, a polymerization rate is determined by the polymerization reaction but not by the diffusion of monomer gas, and thus higher polymerization rate can be achieved.

Abstract: The present invention is related to a rotary throttle position sensor for detecting the position of throttle shaft of internal combustion engine, and aims to increase the reliability in installation on a throttle shaft. The rotor prior to installation is provisionally retained in position to always ensure the initial point of rotation by making a protrusion provided on rotor touch and ride over a protrusion provided on the cover, thereby the rotor is pressed to the case when the cover is assembled on the case.

Abstract: According to the method for producing difluoromethane and 1,1,1,2-tetrafluoroethane, having the steps of:(1) reacting methylene chloride and 1,1,2-trichloroethylene with hydrogen fluoride in a vapor phase In the presence of a fluorinating catalyst and 1,1,1,2-tetrafluoroethane in a first reactor; and(2) reacting 1,1,1-trifluorochloroethane with hydrogen fluoride in a vapor phase in the presence of a fluorinating catalyst in a second reactor, and supplying the reaction mixture from the second reactor to the first reactor, HFC-32 can be obtained in high conversion and high selectivity by fluorinating HCC-30 using commonly a large (excess) amount of HF which is required for producing HFC-134a.

Abstract: A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perohloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF.sub.3 CHCl.sub.2) and/or HCFC-124 (CF.sub.3 CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst.

Abstract: There is provided an azeotropic mixture of hydrogen fluoride (HF) and 1,1-difluoroethane (HFC152a). In addition, there is provided a process for the production of HFC152a having a step of more effectively recovering HF which does not contain HFC152a or HFC152a which does not contain HF in which step an azeotropic mixture is distilled off from a column top by subjecting a mixture containing HFC152a and HF, so that HF which does not contain HFC152a or HFC152a which does not contain HF is recovered from a column bottom.

Abstract: A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perchloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF.sub.3 CHCl.sub.2) and/or HCFC-124 (CF.sub.3 CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst.

Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.

Abstract: A process for preparing 1,1,1-trifluoro-2-chloroethane and/or 1,1,1,2-tetrafluoroethane, comprising the steps of reacting trichloroethylene and/or 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in the presence of a fluorinating catalyst in a gas pase, separating 1,1,1-trifluoro-2-chloroethane, hydrogen fluoride, and optionally trichloroethylene, from the reaction mixture obtained by the above reaction which contains 1,1,1-trifluoro-2-chloroethane, 1,1,1,2-tetrafluoroethane, hydrogen fluoride, and optionally trichloroethylene, and recycling them to the reaction step above, characterized in that at least a part of the reaction mixture is distilled in a distillation tower, 1,1,1,2-tetrafluoroethane-rich components are discharged from the top of the tower, and a mixture of 1,1,1-trifluoro-2-chloroethane and hydrogen fluoride, and optionally trichloroethylene, is discharged in the form of gas from the middle part of the tower at a temperature which is above the boiling point of the azeotropic mixture of 1,1

Abstract: Hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane forms an azeotropic mixture of which molar ratio of HF/1,1,1-trifluoro-2-chloroethane varies, for example, from about 60/40 at a pressure of 1.5 Kg/cm.sup.2 G and a temperature of 20.degree. C. to about 45/55 at a pressure of 15 Kg/cm.sup.2 G and a temperature of 87.degree.C.

Abstract: Hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane forms an azeotropic mixture. A mixture comprising hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane is phase separated when it is cooled to a temperature below 7.degree. C. 1,1,1-Trifluoro-2-chloroethane is purified effectively from the mixture by cooling the mixture to form an upper liquid phase and a lower liquid phase and distilling the lower liquid phase so that the hydrogen fluoride is removed as an azeotropic distillate and 1,1,1-trifluoro-2-chloroethane substantially free from hydrogen fluoride is obtained as a bottom product.