Abstract: A method is provided for manufacturing a wide band retardation plate which gives uniform phase difference characteristics to incident light over the whole visible wavelength region, and which, as it permits selection of raw materials regardless of whether they have a positive or negative intrinsic double refraction value, allows a wide selection of raw materials.

Abstract: A method is provided for manufacturing a wide band retardation plate which gives uniform phase difference characteristics to incident light over the whole visible wavelength region, and which, as it permits selection of raw materials regardless of whether they have a positive or negative intrinsic double refraction value, allows a wide selection of raw materials.

Abstract: A method is provided for manufacturing a wide band retardation plate which gives uniform phase difference characteristics to incident light over the whole visible wavelength region, and which, as it permits selection of raw materials regardless of whether they have a positive or negative intrinsic double refraction value, allows a wide selection of raw materials.

Abstract: This invention provides a method of producing a biaxially stretched polyester film with regulating casting conditions of a polyester film at a high speed so as not to induce surface defects caused by entrapping air microbubbles between a cooling drum and a molten resin sheet, and regulating longitudinal stretching conditions and lateral stretching conditions. The biaxially stretched polyester film is excellent in small thickness variation, resistance to cleavage and improvement in bowing phenomenon, and is particularly suitable for the support of a photographic film.

Abstract: The present invention improves the bowing phenomenon of a biaxially stretched polyester film which comprises stretching the longitudinally stretched cast film laterally at a temperature higher than the glass transition temperature of the polyester film from by 5° C. to by 50° C., staying the laterally stretched film in an intermediate zone for a period from 3 to 30 seconds which has been controlled at a temperature from higher than the lateral stretching temperature by 20° C. or more to lower than a heat setting temperature by 20° C. or less, and then heat-setting at the heat setting temperature which is lower than the melting point of the polyester film from by 30° C. to by 5° C.

Abstract: A process for preparing a silver halide emulsion is disclosed, which comprises dissolving one or more substantially water-insoluble photographic additives in a solution of an organic solvent containing a surface active agent having a hydrophilic -SO.sub.3 or --OSO.sub.3 group wherein said organic solvent is an alcohol, and then adding the resulting solution to a silver halide emulsion. A small amount of a base, or small amounts of a base and an acid may optionally be present in the mixed solution of the organic solvent and the surface active agent prior to adding the one or more substantially water-insoluble photographic additives.

Abstract: A process for preparing a silver halide emulsion, which comprises dissolving one or more substantially water-insoluble photographic additives in a heated solution of an organic solvent containing a surfactant having a hydrophilic --CO.sub.3 or --OSO.sub.3 group to completely dissolve the one or more substantially water-insoluble additives, cooling the resulting solution to precipitate crystals, separating the crystals from the solution, drying the separated crytals, dispersing said crystals in water and adding the resulting dispersion to a silver halide emulsion.

Abstract: In a coating method using a coating head having a coating solution supplying inlet and a slot opening, the coating solution is caused to flow from the inlet to the slot opening in such a manner that the flow width increases gradually while the flow thickness decreases gradually. An apparatus according to the invention has a coating head in which a flow path is formed between an inlet and a slot opening, such that the flow width gradually increases while the flow thickness gradually decreases.

Abstract: A process for preparing a silver halide emulsion is disclosed, which comprises dissolving one or more substantially water-insoluble photographic additives in a solution of an organic solvent containing a surface active agent having a hydrophilic --SO.sub.3 or --OSO.sub.3 group wherein said organic solvent is an alcohol, and then adding the resulting solution to a silver halide emulsion. A small amount of a base, or small amounts of a base and an acid may optionally be present in the mixed solution of the organic solvent and the surface active agent prior to adding the one or more substantially water-insoluble photographic additives.

Abstract: A method for producing gradient gel medium membrane for electrophoresis in which a monomer solution having a continuous concentration gradient and a polymerizing reaction initiator solution are supplied to a coating head as a gel forming solution for electrophoresis while mixing the monomer solution and the polymerizing reaction initiator solution with each other so as to coat a moving web with the gel forming solution. The coating liquid is supplied onto a moving web through the coating head in such a manner so that the flow of the coating liquid extends continuously in the direction of width and is continuously reduced in the direction of thickness along the coating head from its supply inlet to its slot opening.

Abstract: A method for producing gradient gel medium membrane for electrophoresis for determining the base sequence of DNA or DNA partially decomposed material providing an improved productivity. High and low concentration monomer solutions are mixed with a predetermined quantity of polymerizing reaction initiator solution by a static mixer to prepare a gel forming solution for coating on a continuously moving web. The flow-rate ratio of the high and low concentration monomer solutions is gradually changed so as to vary the concentration of the monomer in the gel forming solution alternatively from low to high and from high to low along the web.