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Product Positive. UK. C. Novolak Resin. No. 1

PATENT ASSIGNEE'S COUNTRY UK
UPDATE 06.99
PATENT ASSIGNEE This data is not available for free
PATENT CLAIMS - Condensing formol with phenolic compds in presence of
acid catalyst & photoresist solvent
- Adding water to mixt. thereby forming 2 soln layers, top la
yer comprising soln of unreacted phenols, novolak oligo
mer & monomers in water & bottom layer soln of remaining
mixt in solvent & removing top layer
- Adding water soluble organic polar solvent & water to bo
ttom layer thereby again forming 2 soln layers, bottom la
yer comprising soln of novolak resin condensation prodt in
reaction solvent & top layer comprising soln of novolak oli
gomers & monomer in solvent comprising water/water solu
ble organic polar solvent/reaction solvent & removing the
top layer
- Repeating second & third steps 2 - 10 times for bottom la
yer
- Diluting remaining novolak resin soln with a solvent compri
sing reaction solvent & removing any remaining water & wa
ter soluble organic polar solvent, & thereby producing a
film forming fractionated novolak resin
PATENT PHOTOCOPY Available on request

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