Patent GB-836148-A (GB)
Title: Improvements in or relating to photographic reproduction
IPC: G03G5/06
Filed: 1957-06-26
Abstract: A composition for use on a support in electrophotography comprises a natural resin (which may be modified) together with a 2:5-bis-(p-aminophenyl)-1:3:4-triazole (which may be substituted in the amino groups and/or the ring N-atom), with or without a sensitizing dyestuff.  Specified resins are Manila copal, colophony esterified or modified with formaldehyde, zinc resinate, and polymerized (e.g. dimerized) or hydrated natural resins.  Suitable triazoles and sensitizing dyestuffs are listed. In examples glycol monomethyl ether and benzene are used as solvents.  Specifications 633,747 and 633,796 are referred to.ALSO:2:5 - Bis - (p - aminophenyl) - 1:3:4 - triazoles of the formula <FORM:0836148/IV (b)/1> or <FORM:0836148/IV (b)/2> where R1 is H, alkyl, cycloalkyl or acetyl, R2 is alkyl or acetyl and R3 is H or alkyl, are prepared from the corresponding oxadiazoles (see Specification 851,218) by heating with formamide, followed if desired by alkylation of the triazole N-atom with a dialkyl sulphate.  If the amino groups are primary or secondary the initial product is the N-formyl derivative, and this is subsequently hydrolysed with acid.  Specified triazoles made in this way are 2:5bis - (p - aminophenyl), 2:5 - bis - (p - ethylaminophenyl), 2:5 - bis - (p - dimethylaminophenyl), 2:5 - bis - (p - diethylaminophenyl), 2:5 - bis - (p - dipropylaminophenyl), 2:5 - bis(p - ethylpropylaminophenyl), 2:5 - bis - (pisoamylaminophenyl), 2:5 - bis - (p - cyclohexylaminophenyl) and 2 - (p - dimethylaminophenyl) - 5 - (p - diethylaminophenyl).  Products made by subsequent alkylation are 1ethyl - 2:5 - bis - (p - dimethylaminophenyl)triazole and 1 - methyl - 2:5 - bis - (p - diethylaminophenyl) - triazole.  The N - acetyl compounds are obtained by direct acylation with acetic anhydride, to form e.g. 2:5-bis-(p-acetyl-aminophenyl) - triazole or 2:5 - bis - (p - acetylethylaminophenyl)-triazole.ALSO:A composition for use on a support in electrophotography comprises a synthetic resin together with a photoconductive substance consisting of a 2 : 5-bis-(p-aminophenyl)-1 : 3 : 4-triazole (which may be substituted in the amino groups and/or the ring N-atom), with or without a sensitizing dyestuff. Examples are given of compositions containing the following resins: coumarone, cyclohexanone condensed with methylcyclohexanone, colophony - formaldehyde, resin - modified maleic acid, phenolmodified, ketone, polymerized natural resin and chlorinated polyvinyl chloride.  Other types of resins mentioned are indene; phenolic (especially phenol-formaldehyde, which may be modified with colophony); polyvinyl chloride, acetate, acetals, alcohol and ethers; polyacrylic and methacrylic esters; poly-styrene and isobutylene; phthalates; alkyds; maleic acid resins; colophony esters of mixed higher alcohols; urea- and melamine-formaldehyde, xylene-formaldehyde; polyamides and polyurethanes; aldehyde resins. Suitable triazoles and sensitizing dyestuffs are listed.  The composition may be applied to the support in the form of a solution in benzene, methylene chloride or glycol monomethyl ether. Specifications 633,747 and 633,796 are referred to.