Abstract: A cyclic organic phosphorus compound useful as a stabilizer and a fire retardant for organic substances, particularly, high molecular weight compounds is provided, which compound is expressed by the formula (I): ##STR1## and further a process for producing the above compound (I) is provided, which process comprises reacting a compound expressed by the formula (II): ##STR2## with 1,4-benzoquinone.

Abstract: Novel phenolic compounds useful as a color developer suitable for satisfying the quality requirements of heat-sensitive recording materials are provided, which compounds are expressed by the general formula ##STR1## wherein R.sub.1 represents an alkyl group or a cycloalkyl group and R.sub.2 represents hydrogen atom or an alkyl group; and also heat-sensitive recording materials usable in a broad application field are provided, which recording materials are provided with a heat-sensitive recording layer composed mainly of a colorless basic dye and the above compounds as a color developer by which the dye forms colors, overlaid on a substrate.

Abstract: Novel phenolic compounds useful as a color developer suitable for satisfying the quality requirements of heat-sensitive recording materials are provided, which compounds are expressed by the general formula ##STR1## wherein R.sub.1 represents an alkyl group or a cycloalkyl group and R.sub.2 represents hydrogen atom or an alkyl group; and also heat-sensitive recording materials usable in a broad application field are provided, which recording materials are provided with a heat-sensitive recording layer composed mainly of a colorless basic dye and the above compounds as a color developer by which the dye forms colors, overlaid on a substrate.

Abstract: In a heat-sensitive recording material incorporating a colorless or pale-colored basic dye and a color acceptor which is reactive with the basic dye to form a color when contacted therewith, the recording material characterized in that at least one compound represented by the formula [I] is contained in a heat-sensitive recording layer ##STR1## wherein X is --O-- or --COO--, R.sub.1 to R.sub.4 are each hydrogen atom, alkyl having 1 to 8 carbon atoms, aryl having 6 to 10 carbon atoms, aralkyl having 7 to 9 carbon atoms, chlorine atom, acetyl, propionyl, methoxy, methylthio, methoxycarbonyl, cyano, nitro or cyclohexenyl, substituents R.sub.1 and/or R.sub.2 or substituents R.sub.3 and R.sub.4 may link together to form aromatic ring(s), n is an integer of 1 to 10.

Abstract: In a heat-sensitive recording material incorporating a colorless or pale-colored basic dye and a color acceptor which is reactive with the dye to form a color when contacted therewith, the recording material characterized in that the color acceptor comprises at least one compound represented by the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom, alkyl having 1 to 8 carbon atoms, aryl or aralkyl, provided that R.sub.1 and R.sub.2, as well as R.sub.3 and R.sub.4, are not hydrogen at the same time.

Abstract: Alkali metal salts or/and alkaline earth metal salts of cyclic phosphorus compounds expressed by the general formula ##STR1## (wherein X.sub.1 to X.sub.8 each represent hydrogen, halogen, cyano group, acyl group, alkyl group, halogen-substituted alkyl group, aryl group, halogen-substituted aryl group or aralkyl group) are provided. These metal salts impart a specific flame retardancy to organic high molecular weight compounds prepared from alkylidenebisphenols as a raw material, without lowering the characteristic properties of substrates.

Abstract: Phosphorus-containing condensation products are obtained by effecting condensation between an organophosphorus compound of the Formula, ##STR1## wherein X, Y and Z each is hydrogen or halogen, R.sub.1 and R.sub.2 each is hydrogen or methyl and R.sub.3 is hydrogen or an alkyl group and polyhydric alcohols having at least three alcoholic hydroxyl groups.These condensation products are ueful as a flame retardant for various synthetic resins.

Abstract: Flame-retardant composition comprising (1) a novel organic phosphorous compound having a substituent of ##STR1## where R.sub.3, R.sub.4 and R.sub.5 each is a monofunctional residue selected from a hydrogen atom, a halogen atom, an alkyl or aralkyl group having 1 to 8 carbon atoms, a cyclohexyl group and a phenyl group, on an amino group of an aromatic amino compound and (2) a mixture resin of polystyrene and polyphenylene ether grafted or not with a styrenic compound, said (1) being 2 - 20% by weight and (2) 80 - 98% by weight, on the basis of the composition.