Abstract: A positive photosensitive resin composition containing 100 parts by weight of a polyimide precursor (A) having a constituent unit represented by the formula (1), 15 to 25 parts by weight of a crosslinking agent (B) represented by the formula (2), and 2 to 5 parts by weight of a photosensitizer (C) generating acid upon irradiation of an actinic ray: wherein m is an integer of 1 or greater, and R is an aromatic group or an aliphatic group having a valency of 1 or higher. The positive photosensitive resin composition can be developed by using an aqueous solution of alkali metal carbonate, is capable of forming micropatterns, and has excellent thermal resistance and the like. A method for forming a positive pattern, and uses thereof are also provided.

Abstract: A positive photosensitive resin composition containing 100 parts by weight of a polyimide precursor (A) having a constituent unit represented by the formula (1), 15 to 25 parts by weight of a crosslinking agent (B) represented by the formula (2), and 2 to 5 parts by weight of a photosensitizer (C) generating acid upon irradiation of an actinic ray: wherein m is an integer of 1 or greater, and R is an aromatic group or an aliphatic group having a valency of 1 or higher. The positive photosensitive resin composition can be developed by using an aqueous solution of alkali metal carbonate, is capable of forming micropatterns, and has excellent thermal resistance and the like. A method for forming a positive pattern, and uses thereof are also provided.

Abstract: In a lubrication groove, which is formed in an insertion hole into which is inserted an output shaft, and which winds around the circumference of the insertion hole while advancing in the axial direction of the insertion hole, there is a portion that is farther to the outside than a perpendicular plane that is perpendicular to a center plane of a differential case on which lie the axial centers of the insertion hole and a pinion gear shaft, the perpendicular plane including a line of intersection of the center plane and the insertion hole. That portion is a perpendicular groove portion which is parallel to a plane that is perpendicular to the axial center of the insertion hole. Accordingly, when extracting a core for forming the insertion hole and the lubrication groove from a die, projections formed on the core for forming the lubrication groove will not interfere with the die. As a result, it is possible to form the lubrication groove during casting of the differential case using that core.

Abstract: In a lubrication groove, which is formed in an insertion hole into which is inserted an output shaft, and which winds around the circumference of the insertion hole while advancing in the axial direction of the insertion hole, there is a portion that is farther to the outside than a perpendicular plane that is perpendicular to a center plane of a differential case on which lie the axial centers of the insertion hole and a pinion gear shaft, the perpendicular plane including a line of intersection of the center plane and the insertion hole. That portion is a perpendicular groove portion which is parallel to a plane that is perpendicular to the axial center of the insertion hole. Accordingly, when extracting a core for forming the insertion hole and the lubrication groove from a die, projections formed on the core for forming the lubrication groove will not interfere with the die. As a result, it is possible to form the lubrication groove during casting of the differential case using that core.

Abstract: A branched polyene compound represented by the formula ##STR1## wherein f is an integer of 1-5; R.sup.1 and R.sup.2 represent hydrogen atoms or alkyl groups of 1-5 carbons; R.sup.3 represents a hydrogen atom or an alkyl group of 1-5 carbons or an alkenyl group represented by the formula ##STR2## wherein n is an integer of 1-5; R.sup.4, R.sup.5 and R.sup.6 represent hydrogen atoms or alkyl groups of 1-5 carbons; all of R.sup.1, R.sup.2, R.sup.3 are not simultaneously hydrogen atoms; and all of R.sup.4, R.sup.5 and R.sup.6 are not simultaneously hydrogen atoms.