Abstract: A low-birefringent organic optical component comprising a polymer prepared by polymerizing a racemic mixture of the monomer with an asymmetric spiro ring represented by general formula (1) as an essential ingredient; wherein ring A represents a monocyclic or polycyclic organic group, wherein two ring As are mutually bound each other via a spiro bond to form a spiro ring which has a molecular asymmetric structure; n is an integer of 0 to 10; X.sub.1 and Y.sub.1 are binding groups; and Z.sub.1 is a polymerization-active group. The component has excellent transparency, mechanical strength and heat resistance, as well as a low birefringence.

Abstract: Disclosed are an epoxy acrylate resin of the general formula (1) ##STR1## and an acid-modified epoxy acrylate resin obtained by reacting the epoxy acrylate resin with a carboxylic acid or an anhydride thereof, as well as curable resin compositions containing such a resin and the cured products thereof.

Abstract: Heat-sensitive recording materials contain an electron-donating chromogenic compound and an electron-attracting compound. The recording materials also contain at least one compound represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.3 mean a hydrogen atom or an alkyl, aralkyl or aryl group, R.sub.2 and R.sub.4 denote an alkyl, alkenyl, aralkyl or aryl group, X.sub.1, X.sub.2, Y.sub.1 and Y.sub.2 stand for an oxygen or a sulfur atom, and --Z.sub.1 -- and --Z.sub.2 -- are a specific aromatic group. Also provided are phenol compounds represented by the following formula: ##STR2## wherein R.sub.1, R.sub.2, X.sub.1 and Y.sub.1 have the same meanings as defined above; R.sub.5 and R.sub.6 are a hydrogen or halogen atom or an alkyl, alkoxy, aralkyl, aryl or hydroxyl group; p and q stand for an integer of 1-4; R.sub.5 and R.sub.6 may be either the same or different when p and q represent an integer of 2 or greater; and --Z.sub.3 -- means a specific divalent group.

Abstract: Heat-sensitive recording materials contain an electron-donating chromogenic compound and an electron-attracting compound. The recording materials also contain at least one compound represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.3 mean a hydrogen atom or an alkyl, aralkyl or aryl group, R.sub.2 and R.sub.4 denote an alkyl, alkenyl, aralkyl or aryl group, X.sub.1, X.sub.2, Y.sub.1 and Y.sub.2 stand for an oxygen or a sulfur atom, and --Z.sub.1 -- and --Z.sub.2 -- are a specific aromatic group. Also provided are phenol compounds represented by the following formula: ##STR2## wherein R.sub.1, R.sub.2, X.sub.1 and Y.sub.1 have the same meanings as defined above; R.sub.5 and R.sub.6 are a hydrogen or halogen atom or an alkyl, alkoxy, aralkyl, aryl or hydroxyl group; p and q stand for an integer of 1-4; R.sub.5 and R.sub.6 may be either the same or different when p and q represent an integer of 2 or greater; and --Z.sub.3 -- means a specific divalent group.