Abstract: The present invention provides a novel phthalide compound represented by the following formula, which rapidly forms blue-blue black color with a developer when it is used as a recording material and, since a color image formed therewith has an intense absorption at 700.about.50 nm, it is usable for optical character reader; ##STR1## where R.sup.1 and R.sup.2 represent, independently, alkyl group having 6 or less carbon atoms; cycloalkyl group having 5 or 6 carbon atoms; aryl group; or heterocyclic ring connecting R.sup.1, R.sup.2 and N, R.sup.3 and R.sup.4 represent, independently, alkyl group having 6 or less carbon atoms; cycloalkyl group having 5 or 6 carbon atoms; aryl group; a heterocyclic ring connecting R.sup.3, R.sup.4 and N, X.sup.1 .about.X.sup.3 represent, independently, hydrogen atom, alkyl group having 6 or less carbon atoms, alkoxy group having 6 or less carbon atom or halogen atom, X.sup.

Abstract: This invention relates to a thermosensitive recording material containing at least one of durene derivative represented by the formula (I): ##STR1## wherein Z represents CH.sub.2 OX or H, X represents an alkyl group, a cycloalkyl group, a substituted or unsubstituted aralkyl group or aryl group, or --COR group where R represents an alkyl group or a substituted or unsubstituted aryl group,in a recording layer which contains a leuco dye and a color-developing agent which reacts with said dye so as to form a color by heating, and the thermosensitive recording material having high color sensitivity can be obtained.

Abstract: Disclosed herein is a novel process for producing 1,1-diphenylalkenes, comprising contacting lead peroxide with 1,1-diphenylalkanes having the structure wherein a nitrogen atom of a tertiary amino group is bonded to the para-position of each of the two benzene rings of the 1,1-diphenylalkane, thereby obtaining the corresponding 1,1-diphenylalkenes.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed herein is a novel chromogenic compound of the formula: ##STR1## wherein R represents an alkyl group of 6 to 12 carbon atoms or benzyl group, and ring A and ring B in the quinolyl group may be substituted, a color forming composition containing said chromogenic compound, and pressure- or heat-sensitive recording paper based on said color forming composition.

Abstract: Disclosed herein is a heat-sensitive recording material in which a chromogenic dye-procursor comprises:(A) a mixture comprising at least two divinyl phthalide compounds represented by the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 represent respectively alkyl group of 1 to 6 carbon atoms, alkyl group of 1 to 4 carbon atoms having an alkoxy group of 1 to 4 carbon atoms or cycloalkyl group of 5 to 7 carbon atoms, X.sup.1 and X.sup.2 represent respectively hydrogen atom, alkyl group of 1 to 8 carbon atoms, alkoxy group of 1 to 8 carbon atoms, alkoxy group of 1 to 4 carbon atoms having an alkoxy group of 1 to 4 carbon atoms, cycloalkoxy group of 5 to 7 carbon atoms, alkenyloxy group of 3 to 8 carbon atoms, benzyloxy group, substituted benzyloxy group, furfurloxy group, tetrahydrofurfuryloxy group, phenyl group, substituted phenyl group, phenoxy group, substituted phenoxy group, fluorine atom, chlorine atom or bromine atom, m and n represent 0 or integer of 1 to 4, m+n=4 and R.sup.1 and R.sup.

Abstract: 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.

Abstract: Disclosed herein is a chromogenic compound of the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 respectively represent an alkyl group having 1 to 4 carbon atoms; R.sup.5 represents an alkyl group having 5 to 8 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms; one of X and Y represents a nitrogen atom and the other of X and Y represents a carbon atom, and a color-forming recording composition containing at least one of the chromogenic compounds.

Abstract: The present invention relates to a novel compound of the formula: ##STR1## wherein R.sup.1 and R.sup.2 respectively represent hydrogen atom, lower alkyl group of 1 to 5 carbon atoms, lower alkoxy group of 1 to 5 carbon atoms or halogen atom; R.sup.3 represents hydrogen atom, alkyl group of 1 to 12 carbon atoms, alkoxyalkyl group of 1 to 12 carbon atoms, halogenoalkyl group of 1 to 12 carbon atoms, phenyl group which may be substituted or benzyl group which may be substituted; and m and n are an integer of 1 or 2; providing the R.sup.1 and R.sup.2 do not represent hydrogen atom, methyl group and methoxy group when R.sup.3 represents hydrogen atom or methyl group.Further, the present invention relates to color developing compositions suitable for use in a recording material and pressure- or heat-sensitive recording sheet containing the novel compound of the formula (I).

Abstract: 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.

Abstract: 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.