Method for preparing ultrapure water
US5292439A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1991 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Nov 22, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/90
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.