摘要:
A method produces fatty acid esters by transesterification of fats and oils with the aid of an alcohol, at a high pressure and temperature. Unreacted alcohol is separated inline from the reaction mixture and continuously recycled into the transesterification process. The separation is performed by obtaining a vapour phase and higher density phases of the reaction mixture and concentrating the alcohol in the vapour phase.
摘要:
A method produces fatty acid esters by transesterification of fats and oils with the aid of an alcohol, at a high pressure and temperature. Unreacted alcohol is separated inline from the reaction mixture and continuously recycled into the transesterification process. The separation is performed by obtaining a vapour phase and higher density phases of the reaction mixture and concentrating the alcohol in the vapour phase.
摘要:
A method produces a fatty acid alkylester by transesterification of a fat or oil and an alcohol. The reaction is catalysed by a heterogeneous catalyst immobilised in a tubular reactor at a temperature between 260 and 420° C. and at a pressure higher than 5 bar. A mixture of the fat or oil and the alcohol is led in a continuous flow through the tubular reactor. The catalyst is preferably a metal oxide or a metal carbonate including an alkaline earth metal. The reaction takes place at reduced residence times and contact times compared to the prior art.
摘要:
A method produces a fatty acid alkylester by transesterification of a fat or oil and an alcohol. The reaction is catalysed by a heterogeneous catalyst immobilized in a tubular reactor at a temperature between 260 and 420° C. and at a pressure higher than 5 bar. A mixture of the fat or oil and the alcohol is led in a continuous flow through the tubular reactor. The catalyst is preferably a metal oxide or a metal carbonate including an alkaline earth metal. The reaction takes place at reduced residence times and contact times compared to the prior art.
摘要:
A method has been described for preparing an ultrathin tabular grain emulsion rich in silver bromide, having {111} major faces, wherein tabular grains having a thickness of less than 0.08 &mgr;m exhibit an average aspect ratio of more than 5:1 and account for at least 75% by number of hexagonal grains and a coefficient of variation on average equivalent surface area of less than 0.50. The process is characterized in that during formation, (a) pH is maintained from 0.8 to 10; (b) a gelatino-peptizer is present in a concentration of 0 to 50 g per liter of dispersing medium, and (c) pBr having a value of at least 1.8 is maintained during grain nucleation and pBr is maintained at less than 2.4 during growth provided that a gelatin peptizer which is free from calcium ions and has a methionine content of less than 30 micromoles per gram of gelatino-peptizer is present.
摘要:
A chemically and spectrally-sensitized emulsion has been described, wherein said emulsion comprising (100) cubic silver halide grains with an average edge length of from 0.2 up to 1.5 &mgr;m, has been spectrally sensitized by addition at least three trimethine dyes: a main spectral sensitizer added in an amount of at least 85 mole % of all spectral sensitizers added, followed by adding a second spectral sensitizer in an amount of not more than 10 mole % and a third spectral sensitizer in an amount of at most 1 mole % wherein at least said main spectral sensitizer has two benzoxazole rings in its chemical structure, at least said third spectral sensitizer has two benzimidazole rings in its chemical structure and wherein the said second spectral sensitizer has a structure more sterically hindered than the structure of the other spectral sensitizers. A light-sensitive silver halide photographic film material coated with such emulsion and a radiographic screen/film combination has been described.
摘要:
A film material has been provided with emulsions comprising {111} tabular silver halide grains rich in silver bromide, spectrally sensitive to irradiation in the wavelength range shorter than 420 nm by the presence of at least one blue spectral sensitizer and of at least one azacyanine dye, the formula of which has been given in the description and in the claims. A radiographic screen/film combination or system has also been provided comprising a duplitized film sandwiched between a pair of supporting or self-supporting X-ray intensifying screens, characterized in that i) said pair of supported or self-supporting X-ray intensifying screens essentially consists of luminescent phosphor particles emitting at least 50% and more preferably at least 80% of their emitted radiation in the wavelength range shorter than 420 nm, ii) said film corresponds with the film material disclosed hereinbefore.
摘要:
A photosensitive element which comprises a support, at least one silver halide emulsion layer and at least a non-light sensitive hydrophilic colloidal layer, wherein the silver halide emulsion layer comprises a selenium compound represented by formula (1): ##STR1## wherein: Q represents R.sup.1 SO.sub.2 or R.sup.2 R.sup.3 P=X;each of R.sup.1, R.sup.2 and R.sup.3 the same or different represents OR.sup.4, NR.sup.5 R.sup.6, SR.sup.7, SeR.sup.8 an alkyl group, an aryl group or a heteroaryl group;X represents O, S or Se;each of R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 the same or different represents hydrogen, an alkyl group, an aryl group or a heteroaryl group, or R.sup.5 and R.sup.6 together represents the atoms necessary to form a N-containing ring.The invention also provides a method for the preparation of a photosensitive element as disclosed hereinbefore comprising the step of chemically sensitizing at least one of the silver halide emulsions by means of a selenium compound as defined.
摘要翻译:一种感光元件,其包括载体,至少一种卤化银乳剂层和至少一种非光敏亲水性胶体层,其中所述卤化银乳剂层包含由式(1)表示的硒化合物:其中:Q表示R 1 SO 2或 R2R3P = X; R 1,R 2和R 3各自相同或不同,表示OR 4,NR 5 R 6,SR 7,SeR 8烷基,芳基或杂芳基; X表示O,S或Se; R 4,R 5,R 6,R 7和R 8各自表示氢,烷基,芳基或杂芳基,或者R 5和R 6一起表示形成含氮环所必需的原子。 本发明还提供了一种制备如上所述的感光元件的方法,其包括通过如所定义的硒化合物对至少一种卤化银乳剂进行化学增感的步骤。
摘要:
A method has been disclosed for preparing a tabular silver halide emulsion wherein tabular silver halide grains having an average aspect ratio of at least 2:1, an average crystal diameter from 0.3 &mgr;m to 3.0 &mgr;m and an average thickness of less than 0.50 &mgr;m account for at least 50% of the total projective surface area of said grains, said method comprising the steps of precipitating, spectrally sensitizing and chemically ripening said grains, characterized by spectrally sensitizing by adding to the emulsion grains before chemically ripening at least one J-band aggregating spectrally sensitizing dye and at least one non-J-band aggregating dye. A light-sensitive silver halide emulsion having at least one J-band aggregating dye and at least one non-J-band aggregating dye comprising said tabular grains has also been disclosed as well as a light-sensitive silver halide photographic X-ray material comprising a support, at least one hydrophilic colloid layer on at least one side of said support and one or more photosensitive layer(s) comprising the said silver halide photographic emulsion and a radiographic screen-film combination comprising at least one X-ray intensifying screen in operative association with the said material.
摘要:
A spectrally-sensitized emulsion has been described, wherein said emulsion comprises {111} tabular silver halide grains having an average aspect ratio of at least 2 with two flat parallel {111} crystal faces accounting for a total projective surface of said parallel crystal faces in said emulsion of at least 50%, characterized in that a site-directing compound is present at said faces, satisfying the general formula I as described herein is present. A light-sensitive silver halide photographic film material comprising a support and on one or both sides thereof at least one light-sensitive emulsion layer having an emulsion as disclosed has also been described as well as a radiographic screen/film combination comprising such a light-sensitive silver halide photographic film material and a supporting or self-supporting X-ray intensifying screen, characterized in that said supported or self-supporting X-ray intensifying screen essentially consists of luminescent phosphor particles emitting green light.