Abstract: There is provided a membrane switch film comprising polyethylene-2,6-naphthalenedicarboxylate as the major component and having excellent handling properties and durability, and particularly a film which is suitable for a membrane switch to be used in automobile interior devices which are potentially exposed to high temperature. The film is a membrane switch film having a refractive index in the range of 1.770-1.790 on both surfaces in either or both the film processing direction and the widthwise direction and an absolute value of no greater than 0.015 for the difference between the refractive indexes of both surfaces, or having a melting sub-peak temperature of between 220° C. and 250° C. as measured with a differential scanning calorimeter (DSC) and an absolute value of no greater than 6° C. for the difference between the melting sub-peak temperature on one surface and the melting sub-peak temperature on the other surface.

Abstract: There is provided a laminated film for optical use comprising a polyester film which has a lubricity layer containing globular particles in at least one side thereof, wherein the laminated film has a thickness irregularity of 0.5 to 7.0%, and wherein the polyester film contains inert particles derived from catalysts and the amount of the inert particles determined by a dark-field microscopy satisfies the following conditions: the number of inert particles having a particle size of from 1 to 10 ?m is 200 to 20,000/mm2; and the number of inert particles having a particle size of greater than 10 ?m is 10/mm2. The laminated film for optical use which is improved in uniformity, transparency, lubricity, color tone and scratch resistance, which deposits only a reduced amount of low molecular materials, and which is excellent in the adhesion to a layer adopted for various optical purposes.

Abstract: There is provided a laminated polyester film which is improved in lubricity, transparency, dimensional stability, shock resistance and adhesion, and which comprises a polyester base film comprising polyester and to at least one direction, and a coating layer provided on at least one surface of the base film, wherein said coating layer contains polymer binder and inert particles, the refractive index of the inert particles being substantially same as that of the polymer binder, and wherein the laminated polyester film has a haze of 1.5% or less, a total light transmittance of 85% or more, 50% destructing energy per 100 &mgr;m film thickness of 0.3 J or more, and a thermal shrinkage at 230° C. for 30 minutes of 4% or less.

Abstract: A base film for magnetic recording media, comprising a film layer containing inert fine particles and having an agglomeration rate of the inert fine particles on the surface of the film of 4 to 20%, or a film layer containing inert fine particles and an ester wax of an aliphatic monocarboxylic acid having 8 or more carbon atoms and a polyhydric alcohol and having a water contact angle of the exposed surface of 70 to 90°. A magnetic recording medium, particularly a metal deposited thin film magnetic recording medium comprising this base film is excellent in electromagnetic conversion characteristics.

Abstract: A biaxially oriented polyester film, an adhesive film, or a colored hard coat film for application to CRT or liquid crystal display devices to improve contrast and color purity, characterized in that the film contains a coloring matter; (1) a wavelength (X) of the maximum absorption peak of light in wavelengths of 540 to 630 nm is in the range of 560 to 610 nm; (2) a half band width of the maximum absorption peak of the light is not more than 80 nm; a value (Tx/T540), obtained by dividing a light transmittance (Tx) at the wavelength (X) by a light transmittance (T540) at a wavelength of 540 nm, is less than 0.80; a value (T620/T540), obtained by dividing a light transmittance (T620) at the wavelength of 620 nm by a light transmittance (T540) at a wavelength of 540 nm, is in the range of 0.5 to 1.5; and a value (T450/T540), obtained by dividing a light transmittance (T450) at the wavelength of 450 nm by a light transmittance (T540) at a wavelength of 540 nm, is in the range of 0.5 to 1.5.

Abstract: The aromatic polyamide film of the present invention has microdomain structures having sizes of not less than 5 nm and not more than 600 nm. The film has an easily adhesive property and is suitable for use in printed circuit boards. In addition, it is preferable for use in magnetic recording media that the surface roughness Ra is not less than 0.25 nm and less than 25 nm and the planar orientation coefficient of the film is not less than 0.16 and not more than 0.60. And, in the production method of the present invention, the relation of a time T (minute) to the thickness t (mm) is limited to the expression; 1.2t (t+1)≦T, wherein a time T means the time of from the start of the coagulation process to the peeling of the coagulated film from the support and the thickness t means the thickness of the thin filmy product on the support just after cast. By the production method, the film having the above-mentioned characteristics can be produced in good productivity.

Abstract: An aromatic polyester film, which comprises an aromatic polyester comprising 2,6-naphthalenedicarboxylic acid as the main dicarboxylic acid component and 1,3-propanediol as the main diol component and having a density of at least 1.310 g/cm3. A laminated film comprising another polyester layer can be formed from this aromatic polyester film. An aromatic polyester containing a small amount of a sulfonic acid phosphonium salt used as one of the aromatic polyesters forming this laminated film is excellent in electrostatic casting properties and resistance to the contamination of an electrostatic wire, and an aromatic polyester containing an inorganic anti-fungus agent is used for antifungal application.

Abstract: The aromatic polyamide film of the present invention has microdomain structures having sizes of not less than 5 nm and not more than 600 nm. The film has an easily adhesive property and is suitable for use in printed circuit boards. In addition, it is preferable for use in magnetic recording media that the surface roughness Ra is not less than 0.25 nm and less than 25 nm and the planar orientation coefficient of the film is not less than 0.16 and not more than 0.60.

Abstract: An optical biaxially oriented polyester film, an adhesive film and a colored hard coat film, which can be adhered to the image display surface of a CRT or liquid crystal display device to improve the contrast and color purity of the CRT or the liquid crystal display device without deteriorating the brightness, can be provided.

Abstract: A laminate film has a coated film layer containing a binder resin and an organic filler. The laminate film satisfies the following expressions (1) and (2) when it is heated at 200° C. for 120 minutes: 0≦(Ra1−Ra2)/Ra1<0.4  (1) 0.1<Ra2<7  (2) wherein Ra1 is an average roughness of root mean square (nm) of an exposed surface of the coated film layer before the heat treatment, and Ra2 is an average roughness of root mean square (nm) of the exposed surface of the coated film layer after the heat treatment. The film has protrusions with two or more interference fringes on the surface at a density of 100 per 100 cm2 at the most. The present laminate film is useful as a base film for a magnetic recording medium.

Abstract: A laminate film has a coated film layer containing a binder resin and an organic filler. The laminate film satisfies the following expressions (1) and (2) when it is heated at 200° C.

Abstract: An aromatic polyamide film laminate comprising at least two biaxially oriented films formed of an aromatic polyamide, wherein (1) a film layer A, which is the outermost layer of the laminate, contains inorganic particles produced from hydroxides or carbonates of at least one metal of the groups Ia and IIa of the periodic table, the inorganic particles having an average particle diameter of 80 to 1,500 nm, and has a surface roughness (RaA) of 1 to 20 nm, and (2) a film layer B, which is the layer opposite to the layer A of the laminate, has a surface roughness (RaB) of 0.1 to 10 nm, (3) the surface roughness (RaB) of the film layer B being smaller than the surface roughness (RaA) of the film layer A by 1 nm or more.

Abstract: An aromatic polyamide film for a high-density magnetic recording medium which has excellent electromagnetic conversion characteristics and few drop outs even when it is used as a base film for a deposited metal thin film magnetic recording medium and enables the production of a large-capacity magnetic recording medium. An aromatic polyamide film for a high-density magnetic recording medium which has surface flatness and excellent transferability, is thereby useful as a base film especially for a high-density magnetic recording medium and can satisfy contradictory requirements, that is, the prevention of a trouble such as projection of protrusions in a calendering step and winding easiness at the same time.

Abstract: A biaxially oriented film made from a wholly aromatic polyamide produced by an acid chloride process, which contains at least one member of inorganic particles having an average particle diameter of 5 to 2,000 nm and selected from the group consisting of hydroxides, carbonates and bicarbonates of metals of groups Ia and IIa of the periodic table. The inorganic particles is derived from inorganic particles which are added as a neutralizing agent to a reaction system to neutralize hydrogen chloride by-produced by the acid chloride reaction and its content corresponds to an excess portion added to the reaction system over the amount required for neutralizing the hydrogen chloride stoichiometrically. The film is useful as a base film for a magnetic recording medium, such as a coated, a multi-layer coated, or a thin metal film high-density magnetic recording medium.

Abstract: A laminate film comprises a base film and a second film layer containing core-shell particles and a hydrophilic resin. The laminate film is useful for a base film for a magnetic recording medium.

Abstract: A laminate film comprises a base layer A formed of a thermoplastic resin A and a coating film layer B present on one surface of the base layer A. The coating film layer B contains a binder resin, inert fine particles and a surfactant. The surfactant consists essentially of 0.1 to 15% by weight of a surfactant X having an HLB value of 10 to 14 and 10 to 40% by weight of a surfactant Y having an HLB value of 16 to 18.5 based on the solid content of the coating film layer B to ensure that the average HLB value defined by the following equation be 15 to 18:average HLB=HLB(X).times.(P)X+HLB(Y).times.P(Y)wherein HLB(X) is an HLB value of the surfactant X, P(X) is a weight fraction of the surfactant X with respect to the total weight of the surfactants X and Y, HLB(Y) is an HLB value of the surfactant Y, and P(Y) is a weight fraction of the surfactant Y with respect to the total weight of the surfactants X and Y.The laminate film is useful as a base for a magnet recording medium.

Abstract: A biaxially oriented laminate film comprising a thermoplastic resin layer A and a thermoplastic resin layer B which is laminated on one side of the thermoplastic resin layer A. The surface of the thermoplastic resin layer A has protrusions having an average height of 2 to 85 nm and an average width of 20 to 500 .mu.m, at a density of 4 to 2,500/mm.sup.2. The thermoplastic resin layer B contains inert fine particles, and the surface of the thermoplastic resin layer B is rougher than the surface of the thermoplastic resin layer A. The laminate film can have furher a layer C on the thermoplastic resin layer A. The surface of the thermoplastic resin layer C has protrusions having an average height of 2 to 85 nm and an average width of 20 to 500 .mu.m, at a density of 4 to 2,500/mm.sup.2. These laminate film are useful as a base film for magnetic recording medium.

Abstract: A polyester film having low electrostatic and high adhesion properties and having formed on at least one side thereof a primer layer which has a softening point of 100.degree. to 170.degree. C. and essentially consists of (1) water-dispersible polyester resin containing, as a copolymer component, a sulfonic acid metal salt group-containing compound in an amount of 0.01 mol % or more and less than 0.5 mol % of the whole dicarboxylic acid compound (component A) and (2) polyethylene oxide-monoalkyl ether or a mixture of the same and a polyethylene oxide-polypropylene oxide block copolymer (component B). This adherent polyester film has low electrostatic properties and high heat resistance and is useful as a base film for a magnetic recording medium.

Abstract: A biaxially oriented laminated polyester film comprising a first thin polyester layer containing large-diameter inert particles and small-diameter inert particles; a second polyester layer containing large-diameter inert particles; and a third thin polyester layer containing large-diameter inert particles and small-diameter inert particles, the biaxially oriented laminated polyester film satisfying the following expression (1), ##EQU1## wherein: W.sub.1 is the content (wt. %) of the large-diameter inert particles in the first thin polyester layer, W.sub.2 is the content (wt. %) of the large-diameter inert particles in the second polyester layer, D.sub.13 is a total of the thickness (.mu.m) of the first thin polyester layer and the thickness (.mu.m) of the third thin polyester layer, and D.sub.2 is the thickness (.mu.m) of the second polyester layer. This film is useful as a base film for a magnetic medium.

Abstract: The present invention provides a biaxially oriented polyester film made of a polyester containing 0.01 to 5% by weight of crosslinked polymer particles characterized by:(1) having a particle size distribution ratio (.gamma.) of 1.3 to 3.5,(2) having an average particle diameter of 0.1 to 2 .mu.m,(3) having a non-circularity of 3.4 or more, and(4) having a standard deviation of noncircularity, of at least 0.16.The polyester film of the present invention has a flat surface having a small number of large protuberances, excellent running property and excellent winding property, and can be produced economically. The film has excellent properties for use as a base for various magnetic recording media.