41results about How to "Low coloration" patented technology

The invention is directed to an aluminoborosilicate glass containing alkali metals for the production of optical components with refractive index gradients which are generated by ion exchange of monovalent metal ions in a base glass comprising at least silicon oxide, boron oxide, aluminum oxide and an alkali metal oxide, particularly for the production of gradient index lenses (GRIN lenses). The object of the invention, to find a novel possibility for producing GRIN lenses based on aluminoborosilicate glasses in which the glass has an appreciably reduced tendency toward crystallization in subsequent thermal treatment processes, is met according to the invention in an alkali-containing aluminoborosilicate glass for the production of optical components with refractive index gradients generated by ion exchange of monovalent, refractive index-changing metal ions in a base glass of SiO2, Al2O3, a metal-(III)-oxide (of B and / or Ga) and at least one metal-(I)-oxide (of Li, Na, K and / or Rb) in that defined molar ratios of metal-(III)-oxides to the metal-(I)-oxides of the base glass are adjusted within a given range in order to appreciably reduce the tendency toward crystallization of the glass for subsequent thermal treatment processes. Point defects caused by crystallites in the GRIN lenses produced in this manner are drastically reduced in this way.

Provided is a Li2O—Al2O3—SiO2-based crystallized glass, comprising, as a composition in terms of mass %, 55 to 75% of SiO2, 20.5 to 27% of Al2O3, 2% or more of Li2O, 1.5 to 3% of TiO2, 3.8 to 5% of TiO2+ZrO2, and 0.1 to 0.5% of SnO2, and satisfying the relationships of 3.7≦Li2O+0.741MgO+0.367ZnO≦4.5 and SrO+1.847CaO≦0.5.

Milled rice grains are primarily immersed, and at least surface layers of the grains are converted to the alpha-type. The rice grains are then preliminarily dried and consummatively polished, and are further subjected to secondary immersing and secondary alpha-type conversion. During these processes, there occurs no cracking on the surfaces of the rice grains. The consummatively polished rice grains are then separated into individual single grains. The separated individual single grains are finally dried whereby the finished product of instant rice is obtained. The instant rice containing polished rice has good appearance and quality.

An optical glass comprises, denoted as weight percentages, SiO2-2-22%, B2O3: 3-24%, ZnO:>8% and ≦30%, CaO+BaO+ZnO: 10-50%, MgO: 0-3%, La2O3+Y2O3+Gd2O3+Yb2O3: 1-33%, TiO2: 2-20%, ZrO2: 0-10%, Nb2O5: 2-32%, Li2O: 0-5%, Na2O: 0-8%, K2O: 0-10%, WO3: 0-20%. The ratio by weight of La2O3 to the combined contents of La2O3, Y2O3, Gd2O3, and Yb2O3 (La2O3 / (La2O3+Y2O3+Gd2O3+Yb2O3)) falls within a range of 0.7 to 1.

A process for producing BPDA by which high productivity is attained while maintaining a high purity. The process for biphenyltetracarboxylic acid dianhydride production comprises heating biphenyltetracarboxylic acid to produce biphenyltetracarboxylic acid dianhydride, wherein the heat treatment is conducted at a pressure of 1*10<2>-1.1*10<5> Pa to a maximum temperature in the range of 210-250 DEG C in such a manner that at least 1 / 4 the period used for heating from 60 DEG C to 210 DEG C has a heating rate of 50 DEG C / Hr or higher and that the acid is held at 150-250 DEG C for 0.5-10 hours.

Using at least one compound selected from the group consisting of a zirconyl compound and a zirconium alcoholate as an allophanation catalyst, an allophanate group-containing polyisocyanate composition is produced from a starting material of at least one isocyanate compound selected from the group consisting of an aliphatic diisocyanate, an alicyclic diisocyanate and an isocyanate pre-polymer obtained therefrom, and another starting material of a hydroxyl group-containing compound.

An object of the present invention is to provide a method for producing a saccharide polycondensate which is inexpensive and is applicable to a food or beverage product. Disclosed is a method for producing a saccharide polycondensate, which comprises carrying out a saccharide polycondensation reaction in the presence of activated carbon.

A print medium in which a plurality of color development layers that develop colors to obtain colored portions by being heated are formed at different positions in the thickness direction is conveyed in a first direction. A plurality of heat generation elements that heat the print medium are controlled so as to selectively cause the plurality of color development layers to develop the respective colors. Heating positions on the print medium are controlled such that, in at least one of the color development layers in the print medium, in a case where lines each including a plurality of pixels which are formed by the colored portions and arranged at a predetermined resolution in the first direction are arranged in a second direction, positions of the plurality of pixels are shifted between the lines in the first direction by a distance smaller than an interval corresponding to a resolution.