A NEW TYPE PHOTOPOLYMER DERIVED FROM PIPERAZINE AND DIEPOXY COMPOUNDS

A series of new polymers were obtained by linear addition polymerization of diepoxy compounds with piperazine. Most of the polymers were soluble or developable in dilute acids because of the molecules containing teritiary amino groups. One of the above polymers was prepared from N, N-diepoxypropylaniline with piperazine. Some photosensitive systems can be formed from this polymer with polyhalides and can be photocolorized and photocured simultaneously upon irradiating with near UV (300-400nm). The minimum quantity of exposure energy required for photocuring (Ecur) is 78mJ/cm2. But some properties of this polymer are inadequate in practice.This paper emphasised another new type three-component polymers which were prepared by bisphenol A epoxycompounds and N, N-diepoxypropylaniline with piperazine. These polymers possessed some improved properties, such as photosensitivity, adhesion, alkali resistance and lipophilic nature. Ecur of these polymers --CBr4 photosensitive systems can be as low as 110mJ/cm2. When 50% CBr4 and 5% 2, 4-diethylthioxanthone are added to them Ecur can decrease to 99mJ/cm2. A good effect can be obtained for increasing photosensitivity if 5% 2, 6-bis-(azidobenzal)- 4-methycyclohexanone and 50% CBr4 are added to them. Ecur of these systems can approach 10mJ/cm2. The image of cured film on aluminium can be etched by dilute sodium hydroxide solution. The initial research on the mechanism of photo- curing and photocoloration obtained significant results.