Abstract: Contaminants present inside an ultrapure water production system are prevented from being fed into a feed pipe connected to a water use point and, after sterilization cleaning, the system is prevented from being contaminated by contaminants captured on a microparticle removal membrane during sterilization cleaning. Ultrapure water having high quality is thereby fed to a water use point within a short period of time. An ultrapure water production system is provided with a tank, a pump, a heat exchanger, an ultraviolet device, an ion-exchange device, a first microparticle removal membrane device, and a second microparticle removal membrane device. Parts of sterilization water and flush water are fed into the first microparticle removal membrane device and discharged from a feedwater-side potion to a concentrated-water-side portion without permeating through a microparticle removal membrane thereof, and the remaining part of the water is passed through the second microparticle removal membrane device.

Abstract: In a subsystem or water-feed path located upsteam of a use point in an ultrapure water production/supply process, fine particles having a particle diameter of 50 nm or less, in particular 10 nm or less are highly removed. A device for removing fine particles in water has a membrane filtration device including a microfiltration membrane or an ultrafiltration membrane having a weak cationic functional group. The microfiltration membrane or the ultrafiltration membrane having a weak cationic functional group is preferred to have a polyketone film with the weak cationic functional group. Negatively-charged particles in water are adsorbed by the weak cationic functional group and can thus be removed.

Abstract: Provided are a method and an apparatus for producing pure water in which water that has been subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device is brought into contact with a platinum-group metal catalyst, the method and apparatus eliminating the likelihood of the catalyst being degraded and enabling decomposition of hydrogen peroxide to be performed for a prolonged period of time in a consistent manner. Water-to-be-treated is subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device and subsequently subjected to a hydrogen peroxide removal treatment performed with a hydrogen peroxide removal device including a platinum-group metal catalyst. The TOC concentration in water fed to the ultraviolet oxidation device is 5 ppb or less. An anion exchange resin tower is installed in a stage following the ultraviolet oxidation device.

Abstract: Provided is an ultrapure water production apparatus capable of producing high-quality ultrapure water from which microparticles have been removed at a high level. An ultrapure water production apparatus comprising a subsystem that produces ultrapure water from primary pure water, the subsystem including a membrane unit disposed at the end of the subsystem, wherein the membrane unit is constituted by a plurality of membrane devices arranged in series, the first of the membrane devices being a UF membrane device, an MF membrane device, or an RO membrane device, the last of the membrane devices being a UF membrane device or an MF membrane that is not modified with an ion-exchange group.

Abstract: Provided is a method and apparatus for producing pure water in which water that has been subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device is brought into contact with a platinum-group metal catalyst, the method and apparatus eliminating the likelihood of the catalyst being degraded and enabling decomposition of hydrogen peroxide to be performed for a prolonged period of time in a consistent manner. Water-to-be-treated is subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device 2 and subsequently subjected to a hydrogen peroxide removal treatment performed with a hydrogen peroxide removal device 4 including a platinum-group metal catalyst, wherein the TOC concentration in water fed to the ultraviolet oxidation device 2 is 5 ppb or less. An anion exchange resin tower 3 is installed in a stage following the ultraviolet oxidation device 2.

Abstract: Contaminants present inside an ultrapure water production system are prevented from being fed into a feed pipe connected to a water use point and, after sterilization cleaning, the system is prevented from being contaminated by contaminants captured on a microparticle removal membrane during sterilization cleaning. Ultrapure water having high quality is thereby fed to a water use point within a short period of time. An ultrapure water production system is provided with a tank, a pump, a heat exchanger, an ultraviolet device, an ion-exchange device, a first microparticle removal membrane device, and a second microparticle removal membrane device. Parts of sterilization water and flush water are fed into the first microparticle removal membrane device and discharged from a feedwater-side potion to a concentrated-water-side portion without permeating through a microparticle removal membrane thereof, and the remaining part of the water is passed through the second microparticle removal membrane device.

Abstract: This invention relates to a method for manufacturing a cation exchange resin, wherein the method includes the steps of: copolymerizing a monovinyl aromatic monomer and a cross-linkable aromatic monomer to obtain a cross-linked copolymer; specifying a content of a leachable compound represented by formula (I) to be 400 ?g or less relative to 1 g of the cross-linked copolymer, wherein Z represents a hydrogen atom or an alkyl group, and l represents a natural number; and then sulfonating the cross-linked copolymer to form a sulfonylated cross-linked copolymer.

Abstract: The invention relates to a method for manufacturing an anion exchange resin, wherein the method includes the step of contacting a water soluble polymer containing an anionic dissociative group with a resin to produce an anion exchange resin. In the method, an amount of contact of the water soluble polymer is 0.01 to 10 mmol/L, in terms of an amount of the anionic dissociative group, relative to 1 liter of the anion exchange resin, and a wafer surface flatness (Rms) of the anion exchange resin is 4 ? or less, determined by a silicon wafer test.

Abstract: A method for manufacturing an anion exchange resin, in which remaining of impurities and generation of decomposition products are suppressed and leachables are reduced, the method including the following steps (1-a) to (1-e) of: (1-a) obtaining a cross-linked copolymer by copolymerizing a monovinyl aromatic monomer and a cross-linkable aromatic monomer; (1-b) specifying the content of a specific leachable compound to be 400 ?g or less relative to 1 g of the cross-linked copolymer; (1-c) haloalkylating the cross-linked copolymer so as to introduce 80 percent by mole or less of haloalkyl group relative to the monovinyl aromatic monomer; (1-d) removing a specific leachable compound from the haloalkylated cross-linked copolymer; and (1-e) subjecting the haloalkylated cross-linked copolymer to a reaction with an amine compound.

Abstract: The invention relates to a method for manufacturing an anion exchange resin, wherein the method includes the step of contacting a water soluble polymer containing an anionic dissociative group with a resin to produce an anion exchange resin. In the method, an amount of contact of the water soluble polymer is 0.01 to 10 mmol/L, in terms of an amount of the anionic dissociative group, relative to 1 liter of the anion exchange resin, and a wafer surface flatness (Rms) of the anion exchange resin is 4 ? or less, determined by a silicon wafer test.

Abstract: This invention relates to a method for manufacturing a cation exchange resin, wherein the method includes the steps of: copolymerizing a monovinyl aromatic monomer and a cross-linkable aromatic monomer to obtain a cross-linked copolymer; specifying a content of a leachable compound represented by formula (I) to be 400 ?g or less relative to 1 g of the cross-linked copolymer, wherein Z represents a hydrogen atom or an alkyl group, and l represents a natural number; and then sulfonating the cross-linked copolymer to form a sulfonylated cross-linked copolymer.

Abstract: A water quality evaluation method capable of evaluating quality of water to be evaluated with high precision and a substrate contacting apparatus used in the water quality evaluation method are provided. The substrate contacting apparatus 10 has a sealing performance keeping the interior at a vacuum degree lower than or equal to ?0.094 MPa. A substrate W is accommodated in the substrate contacting apparatus 10 and water to be evaluated is fed therein, after stopping feeding water, the interior of the substrate contacting apparatus 10 is sealed, and the substrate contacting apparatus 10 is sent to an analysis device with the substrate W accommodated therein.

Abstract: An ultrapure water production system that can stably produce ultrapure water having a boron concentration of 1 ng/L or less or a metal concentration of 0.1 ng/L or less, a method for producing ultrapure water using the ultrapure water production system, and a method and a system for washing electronic component members. In an ultrapure water production system that includes a mixed-bed deionization apparatus 16, which includes an anion-exchange resin and a cation-exchange resin, as a final deionization apparatus, the anion-exchange resin is an anion-exchange resin that has been verified to have a boron content of 50 ?g/L-anion-exchange resin (wet condition) or less or an anion-exchange resin in which the amount of leached cation is 100 ?g/L-anion-exchange resin (wet condition) or less.

Abstract: A method for manufacturing an anion exchange resin, in which remaining of impurities and generation of decomposition products are suppressed and leachables are reduced, the method including the following steps (1-a) to (1-e) of: (1-a) obtaining a cross-linked copolymer by copolymerizing a monovinyl aromatic monomer and a cross-linkable aromatic monomer; (1-b) specifying the content of a specific leachable compound to be 400 ?g or less relative to 1 g of the cross-linked copolymer; (1-c) haloalkylating the cross-linked copolymer so as to introduce 80 percent by mole or less of haloalkyl group relative to the monovinyl aromatic monomer; (1-d) removing a specific leachable compound from the haloalkylated cross-linked copolymer; and (1-e) subjecting the haloalkylated cross-linked copolymer to a reaction with an amine compound.

Abstract: A water quality evaluation method capable of evaluating quality of water to be evaluated with high precision and a substrate contacting apparatus used in the water quality evaluation method are provided. The substrate contacting apparatus 10 has a sealing performance keeping the interior at a vacuum degree lower than or equal to ?0.094 MPa. A substrate W is accommodated in the substrate contacting apparatus 10 and water to be evaluated is fed therein, after stopping feeding water, the interior of the substrate contacting apparatus 10 is sealed, and the substrate contacting apparatus 10 is sent to an analysis device with the substrate W accommodated therein.

Abstract: An engine employing oval pistons and cylinders with dual connecting rods for each piston. The connecting rods are connected to each piston by a common wrist pin and to a composite crankshaft. The crankshaft includes a main bearing between the connecting rods of each of the pistons. It also includes a middle portion associated with each piston including two crank pins and the shaft therebetween for receipt of the centrally located main bearing.

Abstract: An engine employing oval pistons and cylinders with dual connecting rods for each piston. The connecting rods are connected to each piston by a common wrist pin and to a composite crankshaft. The crankshaft includes a main bearing between the connecting rods of each of the pistons. It also includes a middle portion associated with each piston including two crank pins and the shaft therebetween for receipt of the centrally located main bearing.

Abstract: A piston ring for an oblong piston is adapted to be received in a peripheral groove on the piston. The piston ring is split and the gap between the split ends is located at the center of one of two spaced curved sections of said piston ring. A corrugated spring is received in the peripheral groove within the piston ring and a gap between its split ends is positioned adjacent a side section which extends between the spaced curved sections. The corrugations which contact the side section are closer together than those which contact the curved end sections of the piston ring. This construction helps to equalize the pressure of the piston ring against the cylinder at points around the outer surface of the piston ring.

Abstract: An internal combustion engine has an oblong piston mounted to reciprocate within an oblong cylinder. The piston is elongated in a direction parallel to the axis of the crankshaft and is provided with piston rings which have sliding contact with the surface of the oblong cylinder. Each piston ring is split and is formed of at least two segments. Gaps may be provided between adjacent ends of the segments and stationary pins fixed on the piston may be received in these gaps. The gaps on one piston ring are misaligned with respect to the gaps on another piston ring.

Abstract: A four cylinder four cycle spark ignition engine has oblong pistons each mounted to reciprocate in sliding contact with an oblong cylinder. Intake valves in a series are positioned in a straight line on one side of and parallel to a central plane extending through the longest dimension of each oblong cylinder. Exhaust valves in a series are positioned in a straight line on the other side of and parallel to that central plane. A cam shaft operates all of the intake valves and another cam shaft operates all of the exhaust valves.