Positive-type Alkaline Developable Photosensitive Branched Polyamides with Low Degree of Branching and Diazonaphthoquinone as a Photosensitive Compound

Abstract

A positive-type photosensitive polyamide based on the branched polyamides with low degree of branching and 1-{1,1-bis[4-(2-diazo-1-(2H)naphthalenone-5-sulfonyloxy)phenyl]ethyl}-4-{1-[4-(2-diazo-1-(2H)naphthalenone-5-sulfonyloxy)phenyl]methylethyl}benzene (S-DNQ) as a photosensitive compound has been developed. The branched polyamides with low degree of branching having amino end groups (2a and 2b) were prepared from a ABB′ type monomer, 4-(2,4-diaminophenoxy) benzoic acid 1 in the presence of diphenyl(2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (DBOP) and triphenylphosphite/pyridine (TPP/Py) as a condensing agent, of which the degrees of branching (DB) were 0.10 and 0.36, respectively. Followed by end-capping with 4-hydroxy benzoic acid, end-modified polymers with phenolic hydroxy groups (4a and 4b) were successfully prepared. The polymer properties were characterized by 1H and 13C NMR, GPC, TG/DTA and DSC, respectively. The photosensitive polymer based on polymer 4a and 30 wt % S-DNQ showed a sensitivity of 140 mJ cm−2 and a contrast of 2.1 when it was pre-baked at 80 °C for 5 min, subsequently exposed to a 436 nm light (g-line) and developed with a developer of 5 wt % aqueous tetramethylammonium hydroxide (TMAH) solution: 2-propanol (4:1 by weight ratio) at 25 °C. A fine positive image of 6 μm line-and-space pattern was obtained when the film was exposed to 300 mJ cm−2 by contact-printing mode.