Abstract: A block copolymer of a polyimide and a polyamic acid is disclosed. Further disclosed are a method for producing the block copolymer and a positive type photosensitive composition comprising the block copolymer. The solubility of the photosensitive composition in an alkaline aqueous solution is controlled to achieve high resolution of a pattern. Further disclosed are a protective film of a semiconductor device and an ITO insulating film of an organic light emitting diode (OLED), which are formed using the block copolymer. The protective film and the ITO insulating film are very stable over time.

Abstract: A method of efficiently manufacturing a film having micro-patterns and an optical film manufactured using the same are used for various optical purposes. The method includes forming a first micro-pattern on one face of the film, and forming a second micro-pattern, which has a geometry equal to that of the first micro-pattern, on the other face of the film by a photo-lithography method using the first micro-pattern formed on one face of the film as a photomask.

Abstract: A method for manufacturing a cylinder head system for a vehicle includes manufacturing a first main mold having an exhaust manifold mold and a first water jacket mold; manufacturing a second main mold having a second water jacket mold; and assembling the first main mold to the second main mold. The exhaust manifold mold is configured to form an exhaust manifold, the first water jacket mold is configured to form a first water jacket for cooling the exhaust manifold, and the second water jacket mold is configured to form a second water jacket for cooling a cylinder block.

Abstract: Exhaust passages are integrally formed in at least a projection portion protruded from a side portion of a cylinder head.

Abstract: Disclosed is an ink composition for solder resist that includes, as a binder polymer, a styrene-maleic anhydride copolymer of which the maleic anhydride group is partly esterified with a lower alcohol, the ink composition forming a solder resist film excellent in flexibility and hence soldering heat resistance as well as adherence.