Showing papers on "Silicic acid published in 1977"
Patent•
07 Jun 1977
TL;DR: In this paper, a light-sensitive lithographic printing plate for negative and positive images is presented, consisting of a hydrophilic support having, in succession, a light sensitive composition layer and a transparent cover film.
Abstract: A light-sensitive lithographic printing plate element suitable for the formation of negative and positive images, simultaneously, comprising a hydrophilic support having, in succession, a light-sensitive composition layer and a transparent cover film in which images for printing are formed by imagewise exposing through the cover film and peeling apart to remove, together with the cover film, the areas having a stronger adhesion to the cover film in the light-sensitive composition layer by utilizing the difference in adhesion to the support and to the cover film between the exposed areas and the unexposed areas of the light-sensitive composition layer, whereby the areas of the light-sensitive composition layer having a stronger adhesion to the support remain on the support, wherein the surface of the support adjacent the light-sensitive composition layer is treated with an aqueous solution containing at least one water soluble oxygen acid or water soluble oxygen acid salt selected from the group consisting of boric acid, boric acid salts, molybdic acids, molybdic acids salts, phosphoric acids, phosphoric acid salts, vanadic acids, vanadic acid salts, tungstic acids, tungstic acid salts, chromic acid, chromic acid salts, silicic acids and silicic acid salts.
200 citations
TL;DR: In this paper, the ionization behavior of silicic acid and polysilicate formation in basic solutions have been studied by precise potentiometry using titration techniques in a hydrogen-electrode concentration cell.
Abstract: The ionization behavior of silicic acid and polysilicate formation in basic solutions have been studied by precise potentiometry using titration techniques in a hydrogen-electrode concentration cell. Polysilicate formation was studied in 1 m NaCl solutions at temperatures from 60 to 290/sup 0/C and at Si(IV) concentrations 0.005 to 0.05 m. At the lowest silica concentration only mononuclear species occur over wide temperature and pH ranges. At hydroxyl numbers from about 0.7 to 1.0 (average charge per silicon) small polysilicates which equilibrate rapidly occur at higher Si(IV) concentrations. Polysilicate formation decreases with increasing temperature. The equilibrium quotient for the most significant reaction, Si(OH)/sub 4/(aq) + OH/sup -/ broken arrows SiO(OH)/sub 3//sup -/ + H/sub 2/O, has been precisely determined from 0.1 to 5.0 m NaCl and to about 300/sup 0/C. Values of the logarithm of the equilibrium quotient for the reaction are 3.96 and 2.20 at 50 and 300/sup 0/C in 1 m NaCl and 4.32 and 2.26 at the same two temperatures in 5 m NaCl. An analytical expression from which the thermodynamic quantities for the reaction can be computed is presented. The small effect of salt concentration is interpreted as evidence for little or no sodium ion complexing.
135 citations
TL;DR: The rate of silica dissolution in the upper 25 to 60 m of the upwelling region off northwest Africa was determined by a stable isotope tracer technique capable of measuring dissolution in presence of simultaneous silicic acid uptake as discussed by the authors.
106 citations
TL;DR: An improved method for the partial chemical synthesis of unsaturated and radioactively labeled phosphatidylcholines is described and sn-glycero-3-phosphorylcholine is reacted with twice the theoretical amount of fatty acid imidazolide and sodium methylsulfinylmethide in dimethylsulfoxide for several minutes at 17 degrees C.
90 citations
TL;DR: A tracer method is described that uses the stable isotope 30Si to measure rates of silicic acid uptake by diatom cultures and natural populations of marine phytoplankton.
57 citations
TL;DR: It is concluded that silicate-silicon may be the active agent in dietary fibre which affects the development of atherosclerosis.
56 citations
Patent•
14 Jun 1977TL;DR: In this article, a silica-containing polyimide resin is applied to a substrate such as graphite fiber or glass cloth to form a composite structure, which is then cured.
Abstract: Fire barrier composition particularly applicable as an acoustic panel-fire wall structure in aircraft, capable of withstanding a 2,000° F. flame temperature, comprising incorporating a silica-containing material such as silicic acid or the reaction product of silicic acid and maleic anhydride, into a resin, particularly a polyimide resin. The resulting silica-containing resin, e.g. silicic acid-filled polyimide, is then applied to a substrate such as graphite fiber or glass cloth, to form a composite structure, which is then cured. The resulting cured composite when subjected to high temperature, e.g. a 2,000° F. flame temperature, forms silicon carbide and/or silicon nitride, in situ, which stabilizes any char that forms.
30 citations
Patent•
03 May 1977
TL;DR: In this paper, a method for making an asbestos-free calcium silicate board, which comprises preparing a slurry of a mixture of silicic acid material, lime material, fibrous wollastonite and pulp with a large amount of water, forming the slurry into a raw board by means of the sheet-forming technique, steaming the raw board and drying.
Abstract: This invention relates to a method for making an asbestos-free calcium silicate board, which comprises preparing a slurry of a mixture of silicic acid material, lime material, fibrous wollastonite and pulp with a large amount of water, forming the slurry into a raw board by means of the sheet-forming technique, steaming the raw board and drying. This invention also relates to the board produced in accordance with the above method.
28 citations
TL;DR: The effects of 0.1 and 1.0 germanic acid/silicic acid concentrations on wall development in Nitzschia alba, Navicula pelliculosa, Cylindrotheca fusiformis, and Cyclotella nana are described.
Abstract: The effects of 0.1 and 1.0 germanic acid/silicic acid concentrations on wall development inNitzschia alba, Navicula pelliculosa, Cylindrotheca fusiformis, and Cyclotella nana are described. Valve development and differentiation are interrupted, and sometimes completely blocked. Girdle band formation is also affected.N. alba produces multiple walls (at 0.1 [Ge]/[Si]) and dense cytoplasmic granules (at 1.0 [Ge]/[Si]).
26 citations
TL;DR: Ceramide aminoethylphosphonate was characterized from the lower fungus Pythium prolatum, appearing to be the first report of a phosphonolipid from fungi.
24 citations
TL;DR: A component of the acetone-soluble lipids of Nocordia rhodochrous grown on glycerol, was purified by column chromatography on silicic acid and characterized by infrared, nuclear magnetic resonance spectroscopy, optical rotation measurement and product identification after alkaline hydrolysis.
Patent•
13 Jun 1977
TL;DR: In this paper, a process for treating the surface of aluminum or aluminum alloy comprising the steps of contacting aluminum and aluminum alloy with hot water or steam to form an aluminum oxide layer thereon and conducting electrolysis using the resulting aluminum or aluminium alloy as an anode by applying direct current in an aqueous solution consisting essentially of a water-soluble salt of at least one oxyacid selected from the group consisting of silicicic acid, phosphoric acid, molybdic acid and vanadic acid.
Abstract: A process for treating the surface of aluminum or aluminum alloy comprising the steps of contacting aluminum or aluminum alloy with hot water or steam to form an aluminum oxide layer thereon and conducting electrolysis using the resulting aluminum or aluminum alloy as an anode by applying direct current in an aqueous solution consisting essentially of a water-soluble salt of at least one oxyacid selected from the group consisting of silicic acid, phosphoric acid, molybdic acid, vanadic acid, permanganic acid, stannic acid and tungstic acid.
TL;DR: In this article, the reaction between aqueous solutions of aluminum nitrate and sodium silicate was studied over a wide range of concentrations and pH values, and the classification of the precipitates was made in terms of their colloidal stability correlated with particle charge measured by electro-osmosis.
Abstract: The reaction between aqueous solutions of aluminum nitrate and sodium silicate was studied over a wide range of concentrations and pH values. Turbidity and precipitate volume measurements allowed solubility boundaries to be determined and the conditions to be defined for the formation of stable and unstable sols. The classification of the precipitates was made in terms of their colloidal stability correlated with particle charge measurements determined by electro-osmosis. The stability domains have been compared with previous work involving the interaction of aluminum salt solutions with preformed silica sols. The results were interpreted in terms of the solubilities of silica and alumina, respectively, of their interaction as oppositely charged sols, and of the possible formation of ‘alumino-silicates’.
Patent•
28 Nov 1977
TL;DR: In this article, a method of treating steel sheets which have good corrosion resistance after forming, which comprises coating a steel sheet with a solution which contains: (a) water-soluble or water-dispersible lithium silicate at a concentration of 2 to 250 g/l, which lithium silicates is a mixture of silicic acid or silicate and lithium salt in a molar ratio of 20:1 to 1:1.
Abstract: A method of treating steel sheets which have good corrosion resistance after forming, which comprises coating a steel sheet with a solution which contains: (a) water-soluble or water-dispersible lithium silicate at a concentration of 2 to 250 g/l, which lithium silicate is a mixture of silicic acid or silicate and lithium salt in a molar ratio of 20:1 to 1:1. (b) at least one water-soluble or water-dispersible saturated or unsaturated fatty acid compound, higher alcohol wax, polyethylene type resin, fluorine type resin or silicone type resin at a concentration of 1 to 250 g/l.
TL;DR: Fatty acid recovery from free fatty acid, phospholipid, glyceride and cholesterol ester zones is more than 90% efficient and there is no oxidation or isomerization of unsaturated fatty acids.
TL;DR: In this article, lean lamb muscle tissue from the longissimus and semitendinosus was removed from intact chilled carcasses at 0, 1, 4, 7 and 9 days postmortem.
Abstract: Lean lamb muscle tissue from the longissimus and semitendinosus was removed from intact chilled carcasses at 0, 1, 4, 7 and 9 days postmortem. Following separation of the lipids by silicic acid column chromatography, fatty acid methyl esters of the nonpolar, phospho- and glycolipid fractions were identified by gas chromatography. Lamb longissimus had significantly (P 0.05). Analysis of variance of the data based on grams fatty acid per 100g tissue resulted in more significant differences between muscles and storage periods than when the data were analyzed on a percent of total fatty acids.
Patent•
07 Oct 1977TL;DR: In this article, an article coated with an abrasion resistant coating is disclosed in which the coating comprises a polyvinyl acetal having an hydroxyl group content, calculated as polyvinel alcohol, of from 35 to 50 percent by weight and silicic acid, the weight ratio of silicaic acid to polyvinylon acetal being from 2:1 to 4:1.
Abstract: An article coated with an abrasion resistant coating is disclosed in which the coating comprises a polyvinyl acetal having an hydroxyl group content, calculated as polyvinyl alcohol, of from 35 to 50 percent by weight and silicic acid, the weight ratio of silicic acid to polyvinyl acetal being from 2:1 to 4:1.
Patent•
29 Sep 1977
TL;DR: In this paper, the authors show that trimethyl-hydroquinone (13.5g) in toluene (100 ml) is reacted 4 hrs. at 85 degrees with isophytol (25g) to give crude dl-alpha-tocopherol (36.2 g) and 26.2g crude acetate.
Abstract: Prodn. of highly pure dl-alpha-tocopherol comprises condensing trimethyl-hydroquinone and a phytol in the presence of (a) silicic acid aluminium oxide gel and/or silicic acid gel, (b) ZnCl2 and (c) a protic acid. The purity of the prod. is such that only a single vacuum distn. is required for final purificn. In an example trimethylhydroquinone (13.5g) in toluene (100 ml) is reacted 4 hrs. at 85 degrees with isophytol (25g) in the presence of silicic acid/aluminium oxide (13.5g) zinc chloride (6g) and conc. HCl (0.5g) to give crude dl-alpha-tocopherol (36.2 g) Acetylation of this gives 26.2g crude acetate. Vacuum distn. gives 20.5g of prod. with a purity of 97.3%.
Patent•
07 Mar 1977
TL;DR: In this paper, a process for treating air-borne dust containing silicon dioxide in order to form a silicic acid or a silicate is described, which is useful as reinforcing fillers in the rubber and plastics industries, as well as additives in the paint, varnish, lacquer, paper, cosmetic, pharmaceutical, feed and pesticide industries.
Abstract: There is provided a process for treating air-borne dust containing silicon dioxide in order to form a silicic acid or a silicate. The air-borne dust is dissolved in an alkali metal hydroxide solution to form an alkali metal silicate solution. The alkali metal silicate solution is purified by treating it with activated charcoal and/or oxidation agents. Non-decomposable substances remaining after the purification step are removed from the alkali metal silicate solution. The alkali metal silicate solution is then reacted with acids and/or salts of aluminum, magnesium and calcium. The resulting product is then filtered, washed and dried, and then comminuted to form a finely divided, amorphous, substantially pure, precipitated, silicic acid or silicate having a whiteness according to Berger at a wave length of 460 mμ of about 90 to about 95% and a specific surface area of about 30 to about 800 m 2 /g BET. The resulting products are useful as reinforcing fillers in the rubber and plastics industries, as well as additives in the paint, varnish, lacquer, paper, cosmetic, pharmaceutical, feed and pesticide industries.
TL;DR: In this paper, the rate constants of these reactions are of the order of 10−13 moles/sec 12cm2. But no significant pressure effect on the rate of clay dissolution was observed.
Patent•
23 Sep 1977
TL;DR: In this article, the X-ray diffraction patterns of H2Si8O17.xH2O and its crystalline K salt are characterized by their X-Ray diffraction pattern and are used as selective adsorbents, catalysts, catalyst supports, agents for separating mixts.
Abstract: Crystalline silicic acid of formula H2Si8O17.xH2O (x nearly equal 1) or 4SIO2.H2O, and its crystalline K salt of formula K2Si8O17.xH2O, are new and are characterised by their X-ray diffraction patterns. The acid has the diffraction parameters (d/I): 18.4/100, 9.02/70, 7.25/25, 6.56/10, 5.97/10, 4.44/10, 3.80/10, 3.68/10, 3.49-3.30/100, 2.52/10, 1.83/50, 1.69/10, 1.75/10. The K salt has the parameters 20.1/100, 10.2/30, 7.31/15, 6.68/15, 5.45/15, 4.29/30, 5.10/40, 3.82/15, 3.66/15, 3.43/90, 3.19/60, 2.91/40, 2.64/15, 2.52/30, 2.44/15, 2.34/15, 2.25/30, 1.83/15. The products have a layer lattice structure and are capable of forming intercalation cpds. with a wide range of polar cpds. They (or the intercalation cpds.) can be used as selective adsorbents, catalysts, catalyst supports, agents for separating mixts. of gases and liqs., slow-release carriers for pharmaceitucals and biocides, fillers, etc., and can be incorporated into polymers by crosslinking with the organic matrix.
TL;DR: Use of the Dole extraction procedure, “clean-up” of the hexane phase with silicic acid, and the 63 Ni assay allow determination of the hydrolysis of 5% or less of microsomal phospholipids using only small amounts of material.
TL;DR: In this article, three isomeric trihydroxy octadecenoic acids were identified by column chromatography using silicic acid and boric acid impregnated with silic acid.
Abstract: Incubation of linoleic acid with barley flour at pH 6.8 leads to the formation of three isomeric trihydroxy octadecenoic acids, namely: 9,12,13-trihydroxy-10-trans-octadecenoic acid, 9,10,13-trihydroxy-11-trans-octadecenoic acid and 9,10,11-trihydroxy-12-trans-octadecenoic acid. The acids were isolated by column chromatography using silicic acid and boric acid impregnated silicic acid and their structures were ascertained by means of IR, NMR and mass spectroscopy.
Patent•
27 Jan 1977
TL;DR: In this paper, a process novelty consists in stabilising H2O2 content with salts of lon-chained carboxylic acids and/or esters of silicic acid.
Abstract: Textiles are pre-cleaned and bleached with an organic liquid contg. H2O2, stabilisers for H2O2, emulsifiers and dispersants and alkaline reagents to set pH >7. Process novelty consists in stabilising H2O2 content with salts of lon-chained carboxylic acids and/or esters of silicic acid. Pref. stabilisers are 0.5-10 wt. % w.r.t. H2O2, alkaline earth-, esp. Ca- or Mg salts of long-chained carboxylic acids and/or silicic acid esters with =5C alcohols. The stabilisers are effective and cause no discolouration Emulsifier or dispersant quantity can be kept low, e.g. 0.25-15 wt. % w.r.t. total soln.
TL;DR: In this paper, a new C20-sterol was isolated from a soft coral, Sarcophyta elegans, by column chromatography on a silver nitrate-impregnated silicic acid with hexane-benzene.
Abstract: A new C20-sterol was isolated from a soft coral, Sarcophyta elegans. From the sterol mixture, the C29-sterol was isolated by column chromatography on a silver nitrate-impregnated silicic acid with hexane-benzene. The chemical structure was determined by infrared absorption, mass, and nuclear magnetic resonance spectrometries. On the basis of the above data, this sterol was identified as 23, 24-dimethylcholesta-5, 23-dien-3β-ol.
Patent•
08 Mar 1977
TL;DR: In this paper, a dry granular alkali metal silicate is chemically reacted with a concentrated mineral acid or an acid hydrogen containing salt to produce a white granular silicic acid compound which will react chemically with an acrylic compound by using an alkaline compound as a catalyst, and by heating the mixture.
Abstract: A dry granular alkali metal silicate is chemically reacted with a concentrated mineral acid or an acid hydrogen containing salt to produce a white granular silicic acid compound which will react chemically with an acrylic compound by using an alkaline compound as a catalyst, and by heating the mixture. The silicic acrylate compound is then polymerized with a catalyst such as a peroxide initiator.
Patent•
24 Jun 1977
TL;DR: In this article, a pyrogenically prepd. is rendered hydrophobic by stirring the silicic acid into a soln. This mixture is used as reinforcing filler material for compsns.
Abstract: Pyrogenically prepd. silicic acid is rendered hydrophobic by stirring the silicic acid into a soln. of a hydrophobing agent in an organic solvent; homogenising the mixt.; admixing further pyrogenically prepd. silicic acid; tempering the mixt.; and post-treating the tempered product in a ball mill. Used as reinforcing filler material for compsns., curable to elastomers, based on diorganopolysiloxanes, in amts. of 5-50, pref. 5-40%, w.r.t. the curable compsn. the filler is partic. advantageous in two-component mixtures vulcanisable at room temp. by the cross-linking of polydiorganosiloxanes contg. terminal silanol gps. with polyfunctional cross-linking agents. There is no thickening of the liquid when the filler is used in high proportions.
Patent•
07 Apr 1977
TL;DR: In this article, the authors describe a method for the hydrogenolysis of maleic anhydride, maleic acid and/or fumaric acid over a catalyst which is a mixt. contg. 0.1-50 wt. % active substances.
Abstract: Prodn. of 1,4-butanediol (I) comprises hydrogenolysis of maleic anhydride, maleic acid and/or fumaric acid over a catalyst which is a mixt.of a Gp. 7b and a Gp. 8 Pt-metal (or their cpds.) supported on a silico-acetate, or its mixt. with silicic acid, as carrier. The carrier is made by treating a silicate, specifically of Mg, Ca, Zn, Ni, Co, Sr, Mn or Cd with acetic acid, and is then impregnated esp. with a soln. of Pt-metal acetate and perrheric acid in acetic acid, to give a compsn. contg. 0.1-50 wt. % active substances. (I) is an intermediate for poly(butylene terephthalate). The compsn. is resistant to abrasive losses in continuous processes; yield is imporved with reduction in by-products, specifically succinic acid, formation; and the catalyst has excellent resistance to O2-contg. gases.