Abstract: A purification method for an aqueous hydrogen peroxide solution, includes passing the aqueous hydrogen peroxide solution through a first H-form strong cation exchange resin column 1, a salt-form strong anion exchange resin column 2 and a second H-form strong cation exchange resin column 3. An H-form strong cation exchange resin having crosslinking of 6% or less, an H-form strong cation exchange resin having crosslinking of 9% or more, or an H-form strong cation exchange resin produced by steps (a) and (b) is used as an H-form strong cation exchange resin packed in the second H-form strong cation exchange resin column 3: (a) copolymerizing a monovinyl aromatic monomer with a crosslinkable aromatic monomer having a non-polymerizable impurity content of 3% by weight or less therein using a predetermined amount of a specified radical polymerization initiator at a predetermined polymerization temperature to obtain a crosslinked copolymer; and (b) sulfonating the crosslinked copolymer.

Abstract: A purification method for an aqueous hydrogen peroxide solution includes subjecting the aqueous hydrogen peroxide solution to a reverse osmosis membrane separation treatment with a high-pressure reverse osmosis membrane separation device. The high-pressure reverse osmosis membrane has a denser skin layer on the membrane surface and is therefore lower in an amount of membrane permeate water per unit operating pressure but higher in the rejection rate of TOC and boron, as compared with a low-pressure or ultralow-pressure reverse osmosis membrane. The high-pressure reverse osmosis membrane permeate water is preferably further subjected to an ion exchange treatment with an ion exchange device including two or more columns packed with gel-type strong ion exchange resins.

Abstract: A purification method for an aqueous hydrogen peroxide solution, includes passing the aqueous hydrogen peroxide solution through a first H-form strong cation exchange resin column 1, a salt-form strong anion exchange resin column 2 and a second H-form strong cation exchange resin column 3. An H-form strong cation exchange resin having crosslinking of 6% or less, an H-form strong cation exchange resin having crosslinking of 9% or more, or an H-form strong cation exchange resin produced by steps (a) and (b) is used as an H-form strong cation exchange resin packed in the second H-form strong cation exchange resin column 3: (a) copolymerizing a monovinyl aromatic monomer with a crosslinkable aromatic monomer having a non-polymerizable impurity content of 3% by weight or less therein using a predetermined amount of a specified radical polymerization initiator at a predetermined polymerization temperature to obtain a crosslinked copolymer; and (b) sulfonating the crosslinked copolymer.

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 method of cleaning and sterilizing an ultrapure water manufacturing system including an ultrapure water manufacturing apparatus, a point of use of ultrapure water, and an ultrapure water channel connecting the ultrapure water manufacturing apparatus and the point of use, a cleaning and sterilizing process including an alkali cleaning step for cleaning at least part of the inside of the system with alkaline solution and a sterilizing step for sterilizing the system with sterile water after the alkali cleaning is treated twice or more. By treating the cleaning and sterilizing process twice or more, metals, organic substances, particles, and bacteria inside the ultrapure water manufacturing system can be highly efficiently removed, and thereby ultrapure water satisfying required water quality can be produced within a short period of time after the cleaning and sterilizing.

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: 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: A sheetfed resist removing apparatus having a substrate (111) being a cleaning object placed therein, includes a treatment chamber (101) forming a closed space, and a spray nozzle (102) to spray a cleaning liquid in a form so-called liquid drops over a surface of the substrate (111), in which the treatment chamber (101) forms the closed space containing the substrate (111) such that the placed substrate (111) faces the spray nozzle (102). This structure allows a cleaning liquid to be in the form of liquid drops in consideration of energy reduction, and permits desirable regulation of the temperature of the liquid drops when the liquid drops contact with the resist film in spraying the cleaning liquid over the resist film on the surface of the substrate (111) to thereby remove the resist film, so that secure removal of the resist film can be accomplished.

Abstract: In a method of cleaning and sterilizing an ultrapure water manufacturing system including an ultrapure water manufacturing apparatus, a point of use of ultrapure water, and an ultrapure water channel connecting the ultrapure water manufacturing apparatus and the point of use, a cleaning and sterilizing process including an alkali cleaning step for cleaning at least part of the inside of the system with alkaline solution and a sterilizing step for sterilizing the system with sterile water after the alkali cleaning is treated twice or more. By treating the cleaning and sterilizing process twice or more, metals, organic substances, particles, and bacteria inside the ultrapure water manufacturing system can be highly efficiently removed, and thereby ultrapure water satisfying required water quality can be produced within a short period of time after the cleaning and sterilizing.

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 plant that can produce ultrapure water with an extremely low rate of impurity concentration such as dissolved oxygen concentration, etc., is provided. A primary pure water is introduced and a catalyst mixed tower 4, wherein catalyst supports strong base anion exchange resins are mixed and filled, is located in the downstream of the ultraviolet oxidation equipment of the ultrapure water production plant 1 producing ultrapure water. Further in the latter part of the catalyst mixed tower 4, membrane degasser 5 and demineralization equipment 6 are located. Hydrogen peroxide generated in the ultraviolet oxidation equipment 3 etc., is decomposed by contacting the catalyst supports filled in the catalyst mixed tower 4 and thus decomposition of the strong base anion exchange resins is inhibited.