Abstract: A photosensitive resin composition which is excellent in resolution, low in cost, and usable in a wide range of structures of polymer precursors each of which is reacted into a final product by a basic substance or by heating in the presence of a basic substance. The photosensitive resin composition includes a base generator which has a specific structure and generates a base by exposure to electromagnetic radiation and heating, and a polymer precursor which is reacted into a final product by the base generator and by a basic substance or by heating in the presence of a basic substance.

Abstract: There is provided a resin laminate having a layer construction of a first inorganic material layer/insulating layer/second inorganic material layer or a layer construction of an inorganic material layer/insulating layer, wherein the insulating layer has a multi-layer structure of two or more resin layers of a core insulating layer and an adhesive insulating layer. In this case, the resin laminate has the adhesive insulating layer which can realize optimal etching, is suitable for etching by a wet process, and has excellent adhesion. At least one of the layers constituting the insulating layer is formed of a polyimide resin which comprises repeating units represented by formula (1) and has a glass transition point of 150 to 360° C. and is dissolvable in a basic solution at a rate of more than 3 ?m/min, preferably more than 5 ?m/min, and most preferably more than 8 ?m/min.

Abstract: A substrate for suspension 10 comprises a metallic substrate 1, an insulating layer 2 formed on the metallic substrate 1, a conductor layer 3 formed on the insulating layer 2, and a cover layer 4 covering the conductor layer 3. The insulating layer 2 and the cover layer 4 are formed from different materials, whose coefficients of hygroscopic expansion are in the range between 3×10?6/% RH and 30×10?6/% RH. The difference between the coefficients of hygroscopic expansion of the two materials is 5×10?6/% RH or less.

Abstract: It is a main object of the present invention to provide a polyimide precursor and a polyimide precursor resin composition, which precursor being easy to synthesize, available at low cost, excellent in storage and capable of giving polyimide that is low in impurities after imidization, irrespective of the chemical structure of the finally-obtained polyimide.

Abstract: A photoradical generator which produces no low-molecular decomposition material but a radical during a photoradical generating process, does not generate a radical during a heating process, exists in a chemically stable state in a resulting product of a radical reaction such as a cured coating layer or the like, has high heat resistance, stability and preserving ability, and is excellent in compatibility or solubility is provided. The photoradical generator is comprised of a compound (a) having a seven-membered ring imide structure-containing group represented by the following formula (1), wherein, R1 to R8 respectively represent a hydrogen atom or a substituent and may be a cyclic structure in which they are bonded to each other.

Abstract: The present invention provides a radical generator having a naphthalimide structure or a crosslinking agent and a photosensitive compound having a function as a radical generator. A photoradical polymerization initiator of the present invention comprises a compound (a) having only one naphthalimide structure-containing group in one molecule. The radial generator of the present invention comprises a compound (c) having two or more naphthalimide structure-containing groups in one molecule and also functions as a crosslinking agent. A first photosensitive compound of the present invention comprises a compound (d) having a naphthalimide structure-containing group and an ethylenic unsaturated group in one molecule. A second photosensitive compound of the present invention comprises a polymer (e) of one or more radical polymerizable compounds containing the compound (d).

Abstract: The present invention provides a radical generator having a naphthalimide structure or a crosslinking agent and a photosensitive compound having a function as a radical generator. A photoradical polymerization initiator of the present invention comprises a compound (a) having only one naphthalimide structure-containing group in one molecule. The radial generator of the present invention comprises a compound (c) having two or more naphthalimide structure-containing groups in one molecule and also functions as a crosslinking agent. A first photosensitive compound of the present invention comprises a compound (d) having a naphthalimide structure-containing group and an ethylenic unsaturated group in one molecule. A second photosensitive compound of the present invention comprises a polymer (e) of one or more radical polymerizable compounds containing the compound (d).

Abstract: The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension. The insulator comprises a laminate of one or more insulation unit layers etchable by a wet process, the insulator having been subjected to plasma treatment after wet etching. The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer.

Abstract: The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension. The insulator comprises a laminate of one or more insulation unit layers etchable byawet process, the insulator having been subjected to plasma treatment after wet etching. The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer.

Abstract: A low expansion polyimide using an inexpensive aromatic dianhydride having good heat resistance. A polyimide resin composition useful as a resin material for forming a product or part requiring a low thermal expansion coefficient and heat resistance, by using the polyimide. A product or part which has a good heat resistance and is produced from the resin composition. The polyimide has a repeating unit represented by: wherein R1 to R6 is a hydrogen atom or monovalent organic group, and R1 to R6 may be bonded to each other. R7 is a divalent organic group.

Abstract: The invention provides a radical generator, although being a self-cleavage type initiator, which is capable of suppressing volatilization of low molecular weight decomposition materials at the time of light radiation and post-baking, and leaving no low molecular weight decomposition materials in the final product, a photosensitive resin composition and an article using the radical generator. The photoradical generator provided according to the invention contains a compound (a) having one or more self-cleavage type radical-generating parts and one or more ethylenic unsaturated groups in one molecule.

Abstract: The present invention is directed to a laminate having a layer construction of metal-insulating layer-metal or a layer construction of metal-insulating layer, which laminate meets conditions for developing large adhesive strength between the insulating layer and the metal, as well as to an insulating film and an electronic circuit using the laminate. The laminate has a layer construction of first metal layer/insulating layer/second metal layer or a layer construction of metal layer/insulating layer. The insulating layer 1 has a multilayer structure of two or more layers. The layers on the side of the adhesive interface with each metal layer (a copper foil 3 and an SUS foil 4), out of the layers constituting the insulating layer 1, each are a thermoplastic resin layer 2. The minimum value of the storage modulus at a temperature at or above Tg of the thermoplastic resin layer 2 is not more than 106 Pa.

Abstract: The present invention provides a laminate comprising an insulating layer having suppressed dusting properties, an insulating film comprising the insulating layer, and an electronic circuit component comprising a pattern of the insulating layer. The laminate has a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer. The insulating layer comprises a laminate of two or more wet etchable insulating unit layers. At the interface between the inorganic material layer and the insulating layer, surface irregularities of the inorganic material layer have been transferred onto the surface of the insulating layer. The average height of the surface irregularities transferred onto the insulating layer is less than the thickness of the outermost insulating unit layer in the insulating layer.

Abstract: The invention provides a radical generator, although being a self-cleavage type initiator, which is capable of suppressing volatilization of low molecular weight decomposition materials at the time of light radiation and post-baking, and leaving no low molecular weight decomposition materials in the final product, a photosensitive resin composition and an article using the radical generator. The photoradical generator provided according to the invention contains a compound (a) having one or more self-cleavage type radical-generating parts and one or more ethylenic unsaturated groups in one molecule.

Abstract: A main object of the present invention is to provide a polymer precursor which exhibits high transmittance to a shorter wavelength range with respect to an electromagnetic wave though the polymer precursor has a part which sequences an unsaturated bond having a ? electron orbit and a single bond alternately.

Abstract: This invention relates to an HDD suspension and a process for its manufacture with high productivity and reliability. The HDD suspension of this invention is manufactured from a laminate composed of a stainless steel substrate, an insulating resin layer and a metal foil by wet-etching the laminate by the use of a basic fluid. The insulating layer of the laminate is composed of plural layers of polyimide, every constituent layer exhibits a mean etching rate of 0.5 ?M/min or more by a 50 wt % aqueous solution of KOH at 80° C., the layers in contact with the stainless steel substrate and the metal foil are those of polyimide (B) exhibiting a glass transition temperature of 300° C. or less and the adhesive strength between the layer of polyimide (B) and either the stainless steel substrate or the metal foil is 0.5 kN/m or more.

Abstract: A polymer compound, wherein a transparency of a polymer compound which is easily colored due to the formation of a conjugated state is improved by a new method different from conventional ones, is provided. More preferably, polyimide having high transparency and original properties such as heat resistance or the like at the same time is provided. A polymer compound comprising a part which sequences an unsaturated bond containing a n electron orbit and a single bond alternately, wherein at least a part of a conjugated state formed by the n electron orbit in a molecule is shortened or weakened due to a three-dimensional structure of the molecule, thereby a transmittance is improved, is provided. Further, as one embodiment thereof, highly transparent polyimide having a repeating unit represented by the following formula (1) is provided: wherein, each of R1 to R6 is independently a hydrogen atom or a monovalent organic group, and which may be bonded each other; R7 is a divalent organic group.

Abstract: A wireless suspension blank is made using a two-layer laminate composed of a metallic layer with the spring property and an electrically insulating layer. The first method includes a first step for working the metallic layer by the photo etching method, a second step for forming a wiring part on the insulating layer by the semi-additive method and a third step for working the insulating layer by the wet-etching method. The second method includes a first step for working the metallic layer by the photo etching method, a second step for forming a wiring part on the insulating layer by the semi-additive method and a third step for working the insulating layer by the plasma etching method. The third method includes a first step for forming a wiring part on the metallic layer by the semi-additive method, a second step for working the metallic layer by the wet-etching method and a third step for working the insulating layer by the dry-etching method or the wet-etching method.

Abstract: The invention provides a radical generator, although being a self-cleavage type initiator, which is capable of suppressing volatilization of low molecular weight decomposition materials at the time of light radiation and post-baking, and leaving no low molecular weight decomposition materials in the final product, a photosensitive resin composition and an article using the radical generator. The photoradical generator provided according to the invention contains a compound (a) having one or more self-cleavage type radical-generating parts and one or more ethylenic unsaturated groups in one molecule.

Abstract: A photoradical generator which produces no low-molecular decomposition material but a radical during a photoradical generating process, does not generate a radical during a heating process, exists in a chemically stable state in a resulting product of a radical reaction such as a cured coating layer or the like, has high heat resistance, stability and preserving ability, and is excellent in compatibility or solubility is provided. The photoradical generator is comprised of a compound (a) having a seven-membered ring imide structure-containing group represented by the following formula (1), wherein, R1 to R8 respectively represent a hydrogen atom or a substituent and may be a cyclic structure in which they are bonded to each other.