Abstract: A surface-protecting film is formed on the surface of the semiconductor element of a resin-sealed semiconductor device to prevent the peeling and cracking of the sealing member used in said device, by coating on said surface a polyimide precursor composition containing a polyimide precursor having a recurring unit constitution represented by the following general formula (1) and heat-curing the coated polyimide precursor composition: wherein R1 is a trivalent or tetravalent aromatic group; R2 and R3 are each a tetravalent organic group having 4 or more carbon atoms; R4 is a bivalent organic group having 4 or more carbon atoms; X is a bivalent organic group containing at least one member selected from the group consisting of oxygen and nitrogen: Y is a monovalent organic group having 15 or less carbon atoms; n=5-100 and m=0-95 with a proviso that n+m=100; and p is 1 or 2).

Abstract: A surface-protecting film is formed on the surface of the semiconductor element of a resin-sealed semiconductor device to prevent the peeling and cracking of the sealing member used in said device, by coating on said surface a polyimide precursor composition containing a polyimide precursor having a recurring unit constitution represented by the following general formula (1) and heat-curing the coated polyimide precursor composition: ##STR1## wherein R.sup.1 is a trivalent or tetravalent aromatic group; R.sup.2 and R.sup.3 are each a tetravalent organic group having 4 or more carbon atoms; R.sup.4 is a bivalent organic group having 4 or more carbon atoms; X is a bivalent organic group containing at least one member selected from the group consisting of oxygen and nitrogen: Y is a monovalent organic group having 15 or less carbon atoms; n=5-100 and m=0-95 with a proviso that n+m=100; and p is 1 or 2).

Abstract: A semiconductor device containing an .alpha.-rays shielding resin layer on at least active portion of a semiconductor element, said .alpha.-rays shielding resin being a special polyimide resin, is excellent in thermal resistance at the time of sealing the semiconductor element, adhesion of the .alpha.-rays shielding layer to the semiconductor element, and .alpha.-rays shielding ability.

Abstract: A light-sensitive polymer composition comprising a poly(amic acid), a special bisazide compound and an amine compound can give a film which has high sensitivity and in which portions exposed to light are not easily released by a developing solution at the time of development.

Abstract: A light- or radiation-sensitive polymer composition comprising (a) a poly(amic acid) having as a major component a repeating unit of the formula: ##STR1## (b) one or more light- or radiation-sensitive compounds having an amino group and an aromatic azide group or aromatic sulfonylazide group in one molecule, and if necessary (c) one or more photosensitizers and/or amine compounds having at least one unsaturated bonding, and/or (d) one or more compounds having at least two unsaturated bonding in one molecule, is highly sensitive to light and radiation and can give a precise relief pattern on a substrate. Further, a finally obtained polyimide film is excellent in heat resistance.

Abstract: A spider of loudspeaker having a base material in the form of a plain-woven fabric of warps and wefts each of which constituted by fibers of an inorganic material. The warps and wefts are coated with a thermosetting resin which in turn is coated with a thermoplastic resin. The spider thus formed is less liable to absorb the ambient moisture and, therefore, is free from distortion.

Abstract: A flame resisting agent to be incorporated into an aqueous spinning dope containing chlorine-containing polymer as a main polymer ingredient for improving the flame resistant property of the fiber spun from the spinning dope which includes a stannic oxide hydrate being substantially amorphous with respect to X-ray diffraction and having a bound water in the range of about 0.5 to about 0.7 mole of H.sub.2 O per 1 mole of SnO.sub.2. The flame resisting agent has a superior dispersibility in an aqueous spinning dope containing chlorine-containing polymer as a main polymer ingredient and the aqueous spinning dope in which the flame resisting agent is incorporated has a superior stability, filtering property and spinning property to give a uniform quality of fibers having a durable, superior flame resistant property.