Showing papers on "Methyl isobutyl ketone published in 1974"

Time evolution of developed contours in poly‐(methyl methacrylate) electron resist

Abstract: The time evolution of exposure contours in poly‐(methyl methacrylate) (PMMA) electron resist is calculated for several time‐dependent developers comprised of various proportions of methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). Contours are calculated for a line of charge incident on 4000 A of resist coated on a low‐atomic‐number substrate. Parameters such as beam energy, incident charge per unit length, original molecular weight, and developer temperature are considered. The use of a time‐dependent developer greatly influences the shape of the developed contours and the development time. The more active the developer (expressed in terms of the PMMA solubility rate), the greater the influence of developer time on the contours. Use of higher beam energies results in developed contours confined closer to the beam axis and less sensitive to development time. The incident charge per unit length is very important. For the MIBK developer and at low doses the characteristic undercut phenomenon is not obtained except for long development times, resulting in an increase in linewidth and a reduction in original resist thickness. The principal result of using lower original molecular weight and/or higher developer temperature is to reduce the development time for a given contour.

Synthesis of Methyl Isobutyl Ketone from Acetone and Hydrogen Catalyzed by Palladium Supported on Zirconium Phosphate

Abstract: The one-step synthesis of methylisobutyl ketone from acetone and hydrogen was investigated by using palladium supported on zirconium phosphate, a bifunctional catalyst. Effects of reaction variables on both the conversion of acetone and the selectivity of methylisobutyl ketone were examined. The experiments were carried out with a continuous flow unit at 110–140°C and 7–25 kg/cm2 over a range of liquid hourly space velocity of acetone for 2–15 hr−1 with a mole ratio of hydrogen to acetone in the range 0.2–1.45. Under these conditions, the conversion of acetone was 20–40%, the selectivity of methylisobutyl ketone being as much 90–97 mol%. It is suggested that the one-step reaction proceeds via a consecutive mechanism.

Determination of Trace Metals in Sodium Dithionite-Citrate Extracts of Soils and Sediments by Atomic Absorption

Abstract: A general method has been developed for the analysis of Co, Cu, Ni, Mo, and Zn in dithionite-citrate extracts of soils and sediments. Because of the high Zn content of dithionite, it is necessary to preclean the dithionite-citrate solution before it is used to extract soils or sediments. This precleaning lowers the detection level significantly for other trace elements as well. Since Fe causes flame interferences in the determination of several first transition series elements by atomic absorption, the size of the individual sample aliquot taken to chelation-solvent concentration is varied to provide a constant quantity of Fe (5,000 µg). The standards and blanks are adjusted to the same Fe content. This approach is necessitated by the wide differences in the Fe concentrations of the dithionitecitrate extracts. Following pH adjustments and addition of ammonium-1-pyrrolidine dithiocarbamate, the trace metals (and Fe) are concentrated via two successive 10-ml methyl isobutyl ketone extractions. Quantities of Fe much greater than 5,000 µg interfere in the solvent concentration step. Natural organics released by the dissolution of free-Fe and -Mn oxides, to the extent that they are represented by fulvic acids, do not cause any significant interference in the ammonium-1-pyrrolidine dithiocarbamate methyl isobutyl ketone extraction of the trace metals due to the releasing effect of the Fe present.

Determination of Lead in Gasoline by Atomic Absorption Spectrometry with a Carbon Rod Atomizer

Abstract: The use of A carbon rod atomizer for the analysis of small amounts of lead in gasoline is described. Variables affecting sensitivity studied include: type of lead salts and type of solvent for standard, sample preparation, and atomizing temperature. A serious problem in the analysis of gasolines for tetraalkyl lead additives by atomic absorption spectrometry is that different lead compounds show different absorbances. This problem can be avoided by the addition of halogen or halides to the gasoline solutions diluted with methyl isobutyl ketone (MIBK). A standard method for atomic absorption spectroscopy with A carbon rod atomizer system for lead is described. The detection limit is 0.001 ppm Pb.

High energy radiation exposed positive resist mask process

Abstract: The development of high energy radiation exposed positive acrylate polymer resist layers by organic liquid developers, such as methyl isobutyl ketone, is improved by adding water to the ketone.

Extraction liquide‐liquide par des esters alkylphosphoriques. III. Séparation de la paire yttrium – gadolinium par l'acide di‐(2‐éthylhexyl)phosphorique

Abstract: The separation of yttrium and gadolinium by solvent extraction with di-(2-ethylhexyl)phosphoric acid (H(DEHP)) from solutions in HNO3 has been studied. The extraction takes place by the same mechanism for both elements. The extraction by the ion-exchange reaction is more selective than the extraction by the solvatation reaction. Methyl isobutyl ketone, compared to kerosene as diluent for H(DEHP), reduces more the extraction of Y than that of Gd, without affecting the mechanisms.

Atomic absorption spectrophotometry of manganese by using the solvent extraction with potassium benzylranthate : methyl isobutyl ketone.

Abstract: 溶媒抽出法を併用するマンガンの原子吸光分析を行なった.キレート剤としては,エチルキサントゲン酸カリウムを用い,マンガンを含む水相中に,11w/v%になるように加え,マンガン-エチルキサントゲン酸錯体を生成させた.この錯体は,pH6.5～9.0の最適pH範囲において,メチルイソブチルケトン中に定量的に抽出され,その抽出化学種はきわめて安定であり,ピロリジンジチオカルバミン酸アンモニウムやジエチルジチオカルバミン酸ナトリウムなどを用いた場合にみられる水相への逆抽出もなかった.抽出後のメチルイソブチルケトンを水相と分離して,直接原子吸光分析用試料とした.なお,抽出時におけるpH緩衝液は,10%酢酸アンモニウムを用いた場合が良好であり,共存イオンの影響は,陽イオンでは,エチルキサントゲン酸カリウムと錯体を生成するニッケル,銅,銀,カドミウム,亜鉛などがマンガン量の40倍以上共存すれば減感干渉を示すことがわかった.陰イオンでは,フェロシアンイオンが著しい減感干渉を示した.本法の応用例として,人体組織中のマンガンおよび組織を固定したのちのホルマリン中のマンガンを定量したが,満足すべき結果を得た.

Compositions of matter

Abstract: Mixture of compounds capable of promoting the growth of animals, e.g. live-stock, said mixture comprising: (a) a compound having growth-promoting properties and further the following physicochemical properties:a solid, yellow, salt-forming weak acid containing the elements carbon, hydrogen, nitrogen and oxygen, consisting of equilibrium-forming components, poorly soluble in carbon tetrachloride and benzene, soluble in chloroform, methyl isobutyl ketone, butyl acetate, ethyl acetate, methanol and alkaline solutions, showing a slightly positive reaction in the aromate test, forming a red color with concentrated sulfuric acid, a dark brown color in the Pauly reaction, a dark red color and turbidity with ferric chloride, decomposing on heating, showing in the ultraviolet region of the spectrum absorption maxima at 233 and 327 nm, and in the infrared region absorption bands at 810, 860, 940, 980, 1090, 1215, 1355, 1455, 1540, 1650, 2390 and 3400 cm 1, or a growth-promoting acceptable salt thereof, and (b) bacitracin or a growth-promoting acceptable salt or complex thereof, said mixture showing a synergistic growthpromoting action and to a method increasing the growth rate of warm-blooded animals.