Ultra-fine foreign material filter
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 常熟联邦化工股份有限公司
- Publication Date
- 2009-12-09
- Estimated Expiration
- Not applicable · inactive patent
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Figure 1
Abstract
Description
technical field
[0001] The invention belongs to the technical field of liquid filters, and in particular relates to an ultrafine foreign matter filter, which is used for filtering out ultrafine foreign matters in liquid materials. Background technique
[0002] For some liquid materials with extremely strict foreign matter requirements, such as liquid pyromellitic acid (PMA) and pyromellitic dianhydride (Pyromellitic Dianhydride, PMDA), the filtration of foreign matter must use ultra-fine foreign matter filtration This is because PMA and PMDA products are ultimately used to manufacture high-end electronic-grade polyimide films. The thinner the electronic-grade polyimide film, the stricter the requirements for foreign matter in PMA and PMDA. At present, the thickness of polyimide film has been processed to 1-1.5 μm abroad, and the number of foreign matter in PMA and PMDA is required to meet the following requirements: under a magnifying glass of 40 times, the number of ultra-f...