Abstract: Objects of the present invention are: to obtain a polyimide that is excellent in heat resistance, transparency, and optical isotropy and is soluble in an organic solvent; to provide, by using either a polyimide or a polyamic acid which is a precursor or the polyimide, a product or a member that is highly required to have heat resistance and transparency; and particularly to provide a product and a member both of which are obtained by applying a polyamic acid solution and a polyimide solution of the present invention to the surface of an inorganic substance such as glass, metal, metal oxide, or a single crystal silicon. These objects can be attained by a polyimide acid and a polyimide which are each prepared from an alicyclic tetracarboxylic dianhydride and a monomer having a fluorene structure.

Abstract: The object of the present invention is to obtain the polyimide and the polyamic acid excellent in heat resistance, low thermal expansion property, and transparency and achieve low birefringence and to provide a product or a member, demanded to have high heat resistance and transparency, by using the polyimide or the polyamic acid. In particular, the object is to provide a product and a member in which the polyimide or the polyamic acid of the present invention is formed on a surface of an inorganic substance such as glass, metal, a metal oxide, or a single crystal silicon. The objects are attained by introducing a rigid structure and an alicyclic structure into a skeleton and using a monomer having a fluorene skeleton together.

Abstract: The object of the present invention is to obtain the polyimide and the polyamic acid excellent in heat resistance, low thermal expansion property, and transparency and achieve low birefringence and to provide a product or a member, demanded to have high heat resistance and transparency, by using the polyimide or the polyamic acid. In particular, the object is to provide a product and a member in which the polyimide or the polyamic acid of the present invention is formed on a surface of an inorganic substance such as glass, metal, a metal oxide, or a single crystal silicon. The objects are attained by introducing a rigid structure and an alicyclic structure into a skeleton and using a monomer having a fluorene skeleton together.

Abstract: Objects of the present invention are: to obtain a polyimide that is excellent in heat resistance, transparency, and optical isotropy and is soluble in an organic solvent; to provide, by using either a polyimide or a polyamic acid which is a precursor or the polyimide, a product or a member that is highly required to have heat resistance and transparency; and particularly to provide a product and a member both of which are obtained by applying a polyamic acid solution and a polyimide solution of the present invention to the surface of an inorganic substance such as glass, metal, metal oxide, or a single crystal silicon. These objects can be attained by a polyimide acid and a polyimide which are each prepared from an alicyclic tetracarboxylic dianhydride and a monomer having a fluorene structure.

Abstract: An object of the present invention is to obtain a polyamide-imide solution that has a low linear thermal expansion coefficient, that is, an excellent linear thermal expansion coefficient, and that also is excellent in coating applicability. A further object of the present invention is to provide, with use of the polyamide-imide solution, a product or member which has high requirements for heat resistance and a low linear thermal expansion coefficient. In particular, the present invention is intended to provide a product or member that is suitably used for applications in which the polyamide-imide film obtained from the polyamide-imide solution of the present invention is formed on a surface of an inorganic material such as metal, metal oxide, or monocrystalline silicon.

Abstract: In conjunction with the manufacture of a multilayer ceramic capacitor having nickel-containing internal electrodes involving a polishing step for exposing the end of the internal electrodes, a non-reducible dielectric ceramic material is prepared, for the purpose of preventing the polishing step from being prolonged, by furnishing a calcined material containing a compound oxide represented by the formula (I): [(CaxSr1−x)O]m[(TiyZr1−y)O2] wherein 0≦x≦1, 0≦y≦0.10, and 0.75≦m≦1.04, as a main component, adding 0.001-10 mol % based on the main component of MgO or rare earth oxide and firing the mixture. The ceramic material contains predetermined amounts of SiO2 and BaO and/or CaO, and MnO as auxiliary components.

Abstract: The invention is a magnetic recording medium which is effectively protected against forgery by the alteration of recorded data, and a method for carrying out writing and reading on this magnetic recording medium. The magnetic recording medium of the invention comprises a recording material composed of a crystalline alloy containing Fe and Al . In the recoding material, the total amount of Fe and Al is at least 90 at % and the atomic ratio Al/(Fe+Al) ranges from 0.30 to 0.45. The recording material changes from a disordered phase to an ordered phase by heating. The recording material has a saturation magnetization of at least 45 emu/g prior to heating and lowers its saturation magnetization by at least 35 emu/g upon heating. Dark regions are observable in a bright-field image of the recording material by transmission electron microscopy, the dark regions accounting for 15-60% of the recording material in areal ratio and having a maximum breadth of 10-200 nm.