Disclosed is a salt represented by formula (I): ##STR00001##
wherein, in formula (I), Q.sup.1 and Q.sup.2 each independently represent a fluorine atom or the like, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or the like, Z represents an integer of 0 to 6, X.sup.1 represents *—CO—O— or the like, where * represents a bonding site to C(R.sup.1)(R.sup.2) or C(Q.sup.1)(Q.sup.2), L.sup.1 represents a single bond or a saturated hydrocarbon group, and —CH.sub.2— included in the saturated hydrocarbon group may be replaced by —O—, —S—, —SO.sub.2— or —CO—, A.sup.1 represents a divalent alicyclic hydrocarbon group which may have a substituent, R.sup.a represents a cyclic hydrocarbon group which may have a substituent, and Z.sup.+ represents an organic cation.

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has at least the following repeating unit (I): ##STR00001## wherein: A is a direct bond or an alkylene; X is —C(O)O—, —OC(O)—, —C(O)N(R.sub.6)—, —N(R.sub.6)C(O)—, —C(O)—, —N(R.sub.6)—, —O—, or —S—; R.sub.6 is H or an alkyl; R.sub.1 includes a C.sub.1-C.sub.80 alkyl, a C.sub.2-C.sub.20 alkenyl, a C.sub.2-C.sub.20 alkynyl, a C.sub.3-C.sub.12 aryl, or a polyether; and n is an integer from 1 to 200. The present invention also provides a method for forming the alkylphenol copolymer containing the aforementioned repeating unit (I) as well as a method for forming a monomer for forming repeating unit (I).

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has at least the following repeating unit (I): ##STR00001## wherein: A is a direct bond or an alkylene; X is —C(O)O—, —OC(O)—, —C(O)N(R.sub.6)—, —N(R.sub.6)C(O)—, —C(O)—, —N(R.sub.6)—, —O—, or —S—; R.sub.6 is H or an alkyl; R.sub.1 includes a C.sub.1-C.sub.80 alkyl, a C.sub.2-C.sub.20 alkenyl, a C.sub.2-C.sub.20 alkynyl, a C.sub.3-C.sub.12 aryl, or a polyether; and n is an integer from 1 to 200. The present invention also provides a method for forming the alkylphenol copolymer containing the aforementioned repeating unit (I) as well as a method for forming a monomer for forming repeating unit (I).

An object is to provide a cured product having excellent heat resistance and dielectric properties (low dielectric properties) and prepregs, circuit boards, build-up films, semiconductor sealing materials, and semiconductor devices having these pieces of performance by using a curable resin having a specific structure. Specifically, provided is a curable resin having a structural unit (1) represented by General Formula (1) below and a terminal structure (2) represented by General Formula (2) below. In Formulae (1) and (2) above, the details of R.sub.1, R.sub.2, R.sub.3, k, and X are as described herein.

##STR00001##

An object is to provide a cured product having excellent heat resistance and dielectric properties (low dielectric properties) and prepregs, circuit boards, build-up films, semiconductor sealing materials, and semiconductor devices having these pieces of performance by using a curable resin having a specific structure. Specifically, provided is a curable resin having a structural unit (1) represented by General Formula (1) below and a terminal structure (2) represented by General Formula (2) below. In Formulae (1) and (2) above, the details of R.sub.1, R.sub.2, R.sub.3, k, and X are as described herein.

##STR00001##

A light emitting element includes a first semiconductor layer; an active layer on the first semiconductor layer; a second semiconductor layer on the active layer; an insulating film surrounding an outer peripheral surface of each of the first semiconductor layer, the active layer and the second semiconductor layer; and a polymer film including a polymer chain and on at least a portion of a surface of the insulating film.

A light emitting element includes a first semiconductor layer; an active layer on the first semiconductor layer; a second semiconductor layer on the active layer; an insulating film surrounding an outer peripheral surface of each of the first semiconductor layer, the active layer and the second semiconductor layer; and a polymer film including a polymer chain and on at least a portion of a surface of the insulating film.

A method for synthesizing a poly(phenylene) with high ion selectivity comprises dissolving an alkyl halide poly(phenylene) in a polar aprotic solvent to form a nonaqueous solution and adding an anhydrous nucleophile to the nonaqueous solution to replace the halide of the alkyl halide poly(phenylene) with a cationic group of the nucleophile. The poly(phenylene) can be used in anion exchange membranes.

A method for synthesizing a poly(phenylene) with high ion selectivity comprises dissolving an alkyl halide poly(phenylene) in a polar aprotic solvent to form a nonaqueous solution and adding an anhydrous nucleophile to the nonaqueous solution to replace the halide of the alkyl halide poly(phenylene) with a cationic group of the nucleophile. The poly(phenylene) can be used in anion exchange membranes.

The present invention provides with an electron-accepting compound having a structure of the following formula (1): ##STR00001##