Yamada Chemical Co., Ltd.

Yoshiharu Fujino

Katsuhiko Tsunemitsu

Hajime Kawai

Seiichi Nieda

Kazuhiko Gendai

Youji Shimizu

Yasushi Nakai

Yoji Shimizu

Disclosed herein is a process for producing 3,3-bis-(4-dimethylaminophenyl)-6-dimethylaminophthalide, which process comprises oxidizing 2-[4,4'-bis-(dimethylamino)-benzhydryl]-5-dimethylaminobenzoic acid in an aqueous solution of a mineral acid of pH of from 2.0 to 4.0 with air, oxygen or a gas containing oxygen in the presence of at least one catalyst selected from the group consisting of compounds of iron, copper, cobalt, nickel, chromium, vanadium and manganese.

Process for producing

Disclosed herein are novel divinyl compounds represented by the formula (I): ##STR1## and a recording-material prepared by utilizing the divinyl compounds. The divinyl compound is in itself almost colorless, extremely stable in the atmosphere and develops rapidly blackish color by a developer. The color image given by the divinyl compound is excellent in light-resistance and moisture-resistance and the letters developed can be read by an optical letter-reading apparatus or a barcord reading apparatus.

Divinyl compounds and chromogenic recording-material prepared by using

Disclosed herein are novel divinyl compounds represented by the formula (I): ##STR1## and a recording-material prepared by utilizing the divinyl compounds. The present divinyl compound is in itself almost colorless, extremely stable in the atmosphere and develops rapidly blakish color by a developer. The color image given by the present divinyl compound is excellect in light-resistance and moisture-resistance and the letters developed can be read by an optical letter-reading apparatus or a barcord reading apparatus.

The chromogenic azaphthalide compounds of the invention are of the formula: ##STR1## wherein A is a pyridine ring; R.sub.1 is hydrogen atom or alkyl radicals of from one to 4 carbon atoms; X is hydrogen atom, alkyl radicals of from one to 2 carbon atoms or alkoxy radicals of from one to 2 carbon atoms; R.sub.2 is alkyl radicals of from one to 2 carbon atoms or phenyl radical; R.sub.3 is hydrogen atom or alkyl radicals of from one to 8 carbon atoms. These compounds are particularly suitable for use in providing high quality pressure- or heat-sensitive copying sheets.

Chromogenic compounds

Novel chromogenic fluoran compounds of the formula: ##STR1## wherein R.sub.1 is selected from the group consisting of alkyl radicals of from five to eight carbon atoms; R.sub.2 is selected from the group consisting of alkyl radicals of from one to eight carbon atoms; R.sub.3 is selected from the group consisting of hydrogen atom and lower alkyl radicals of from one to four carbon atoms; X.sub.1 and X.sub.2 are independently selected from the group consisting of hydrogen atom and lower alkyl radicals of from one to four carbon atoms, X.sub.3 is selected from the group consisting of hydrogen atom, lower alkyl radicals of from one to four carbon atoms, halogen atoms and trifluoromethyl radical; and n is an integer of a value of 1 or 2; providing that R.sub.1 does not represent an amyl radical when R.sub.2 is selected from the group consisting of alkyl radicals of from one to five carbon atoms, X.sub.1 and X.sub.2 are each a hydrogen atom, X.sub.3 is selected from the group consisting of hydrogen atom, lower alkyl radicals of from one to four carbon atoms and halogen atoms.

Growing community of inventors

Tsuzuki, Japan

Yoshiharu Fujino