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US 5,292,439 AGranted
Method for preparing ultrapure water
AssigneeMitsubishi Kasei Corporation
InventorsTakamitsu Morita, Junya Watanabe, Toyokazu Sugawara
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AssigneeMitsubishi Kasei Corporation
InventorsTakamitsu Morita, Junya Watanabe, Toyokazu Sugawara
Estimating the term…
A method for preparing an ultrapure water, from which impurities including inorganic salts, organic substances, fine particles and microorganisms are removed, by treatment including an ion exchange treatment, which comprises using an ion exchange resin comprising a copolymer of a polyvinyl compound and a monovinyl aromatic compound which may contain a monovinyl aliphatic compound, as the matrix, at least in a mixed bed ion exchange treatment of the ion exchange treatment, said ion exchange resin used comprising at least a regenerated form ion exchange resin A eluting an organic compound of a molecular weight of less than 3,000 but substantially not eluting an organic compound of a molecular weight of not less than 3,000 when dipped in a hot water at 50.degree. C. for 7 days.
A method for preparing ultrapure water, including removing impurities including inorganic salts, organic substances, fine particles and microorganisms, comprising flowing water to be purified through an ion exchange resin containing a copolymer comprising a polyvinyl compound and a monovinyl aromatic compound as a matrix, said ion exchange resin further comprising a regenerated form ion exchange resin eluting an organic compound of a molecular weight of less than 3,000 but substantially not eluting an organic compound of a molecular weight of not less than 3,000 when dipped in a hot water at 50.degree. C. for 7 days.
A method for preparing ultrapure water, including removing impurities including inorganic salts, organic substances, fine particles and microorganisms, comprising flowing water to be purified through a mixed bed ion exchange medium comprising a strong acidic cation exchange resin and a strong basic anion exchange resin, said mixed bed ion exchange medium further comprising, as a matrix, a bead-like copolymer resin of styrene and divinyl benzene crosslink-copolymerized in a suspension solvent, said strong basic anion exchange resin being a regenerated form strong basic anion exchange resin having a quaternary ammonium group washed with a solvent containing at least 80% of methanol and further washed with water to remove the solvent, and said strong basic anion exchange resin eluting an organic compound of a molecular weight of less than 2,000 but substantially not eluting an organic compound of a molecular weight of not less than 2,000 when dipped in a hot water at 50.degree. C. for 7 days.
Dependencies are inferred from the claim text.