Abstract: 4,4-Dimethyltetrahydrofuran-2,3-dione is prepared by reacting a dimethylpyruvate (II) with formaldehyde or a formaldehyde donor at 80.degree.-150.degree. C.

Abstract: Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid in the presence, in suspension, of a supported platinum catalyst obtainable by precipitating metallic platinum from an aqueous platinum solution onto a support by means of a reducing agent in the presence of an organic chelating agent and partially poisoned with sulfur.

Abstract: Laser-optical recording material comprises:(a) an optically transparent and isotropic, homogeneous substrate which is free of orientation birefringence and(b) one or more amorphous, thermally alterable recording layers,wherein the substrate (a)(a.sub.1) has one or two structured surfaces, the structures being in the micrometer and/or submicrometer range, and is formed form a blend of poly-(2,6-dimethylphenylene ether) (PPE) with one or more styrene polymers, the content of PPE in this blend being about 25-45% by weight, based on the blend, and(a.sub.2) that part of the blend which is not PPE contains, based on this part (a.sub.2),(a.sub.21) from 0.1 to 8% by weight of cyanoethylene groups and/or(a.sub.22) from 1 to 60% by weight of 1-methyl-1-phenylethylene groups and/or(a.sub.23) from 1 to 60% by weight of 4'-methylphenylethylene groups and/or(a.sub.24) from 0.01 to 10% by weight of groups of the general formula I ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is C.sub.1 -C.sub.10 -alkyl, C.sub.

Abstract: Carboxylic esters are prepared by reacting carboxylic acids with low-boiling alcohols by charging the reaction mixture to a 1st distillation column, withdrawing the reaction components carboxylic ester, water and unconverted alcohol as overhead product and charging this overhead product to a 2nd distillation column, from which(a) the overhead product comprises the alcohol or an azeotropic mixture of alcohol and water or alcohol and esteer, this overhead product being recycled into the esterification reaction(b) a liquid side product comprising carboxylic ester and water is withdrawn from the stripping section and separated in a phase separating vessel into water and carboxylic ester and the carboxylic ester is returned into the distillation column below the side takeoff point, and(c) the bottom product removed is the carboxylic ester.

Abstract: Diphenyl ether derivatives of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and n have the meanings stated in the description, processes for their preparation, herbicides which contain these compounds as active ingredients, and a method of controlling undesirable plant growth by means of the novel compounds.

Abstract: The properties, and particularly the print gloss, of coated, unprinted paper may be predicted using surface profilometry. The profilometer is preferably hand held so the contour of paper in jumbo rolls in the finishing and storage area may be determined quickly. The surface contour is then compared to a calibration curve to predict the desired property.

Abstract: Porous green ceramic parts may be prepared by componding 90 to 60 weight percent of a particulate ceramic material with 10 to 40 weight percent, on a dry basis, of a latex of a polymer. The compound is frothed, shaped and set. The green part may then be sintered. The process avoids the expense of preparing solid ceramic compounds containing waxes or sawdust which burn out to create voids. The process is useful to prepare ceramic filters, catalysts, or light weight metal ceramic foams.

Abstract: One-component, moisture-curable sealant compositions having fast cure times comprise a mixture of a silane-capped polyurethane polymer, an aminosilane cross-linking agent, and a titanium ester accelerator.

Abstract: Oxidized polyethylenes useful as water-emulsifiable waxes and as lubricants in the extrusion of polyvinyl chloride are prepared by oxidizing finely divided polyethylene of high density at elevated temperatures with an oxidation gas of air and/or oxygen, the oxidation gas supplied per hour containing not less the 100 mg of ozone per kilogram of polyethylene, by performing the oxidiation in a paddle dryer and passing the oxidation gas into the free gas space above the polyethylene, the temperature in the paddly dryer preferably being continuously adjusted to from 1.degree. to 2.degree. C. below the softening point of the polyethylene.

Abstract: A tanning assistant useful in particular for tanning in combination with aluminum tanning agents is obtained by condensing melamine with glyoxal and/or glyoxylic acid and optionally with an aromatic compound which has a phenolic hydroxyl group or optionally with a condensable nitrogen compound.

Abstract: N-Phenyltetrahydrophthalimide compounds of the formula I ##STR1## where R.sup.1 is hydrogen, fluorine or chlorine, R.sup.2 is chlorine or bromine, R.sup.3 is hydrogen or C.sub.1 -C.sub.3 -alkyl, and R.sup.4 is a 5- or 6-membered, saturated or unsaturated heterocyclic compound containing an oxygen or a sulfur atom and which is unsubstituted or substituted by a maximum of three C.sub.1 -C.sub.3 -alkyl groups, methods of manufacturing these compounds, and their use as herbicides.

Abstract: A conductive foam having a surface resistance of not more than 9.9.times.10.sup.10 ohms as measured by DIN 53,345 may be prepared by incorporating into the base compound at least about 5 parts by dry weight per 100 parts by weight of polymer of a dispersion of carbon black stabilized by a soap predominantly of the same type as that compatible with the process used to set the foam; and processing the compound in a conventional manner.

Abstract: A process for the preparation of stable dispersions of finely divided polyisocyanates, and the preparation of heat-crosslinkable isocyanate systems.Stable dispersions of finely divided polyisocyanates in a liquid which may or may not contain surfactants, protective colloids and other assistants are obtained by a method in which polyisocyanates are treated with a stabilizer in the presence of absence of the liquid, and the dispersions prepared from these are finely dispersed and/or milled under the action of high shear forces, if necessary with the addition of further stabilizer.These dispersions are useful as crosslinking agents, particularly for the preparation of heat-cross-linkable isocyanate systems.

Abstract: Polyurethane/polyisocyanurate rigid foams having low thermal conductivity are prepared from isocyanate-terminated quasi-prepolymers prepared from polyester polyols derived from phthalic anhydride or from the transesterification of polyethylene terephthalate scrap.

Abstract: This invention relates to a process, which comprises spreading a metallomacrocyclic polymer dissolved in an organic, water-immiscible solvent on a water surface, removing the solvent to form a monomolecular, uniformly oriented film of said polymer on the surface of the water, immersing a substrate in the water, and withdrawing the substrate from the water, whereby said polymer film is transferred from the water surface to the substrate.

Abstract: Photopolymerizable recording materials suitable for producing photoresist layers and lithographic printing plates are composed of one or more photopolymerizable olefinically unsaturated organic compounds, optionally a polymeric binder, one or more photopolymerization initiators, a color-forming system which on irradiation with actinic light causes an increase in the color intensity of the recording material, a sensitizer and optionally further additive and/or auxiliary substances, and contain as the color-forming system(a) one or more colorless or virtually colorless organic compounds which are oxidizable to colored compounds, and(b) a photooxidant for the colorless or virtually colorless organic compound(s) (a),wherein photooxidant (b) comprises an organic salt with a substituted or unsubstituted hetaromatic system, this hetaromatic system having one or more built-in groups of the general formula (I) ##STR1## where R is substituted or unsubstituted alkenyl, alkynyl, hetaryl, alkoxycarbonyl, carbamoyl, alkyls

Abstract: Hydroxyoxaalkylmelamines of the general formula I ##STR1## where the radicals R may be identical or different and are each hydrogen or a radical of the general formula IIH--(--O--CHR'--CHR'--)--.sub.n (II)where the radicals R' may be indentical or different and are each hydrogen or C.sub.1 -C.sub.4 -alkyl and n is 2 or 3, and mixtures of these, are useful intemediates for the preparation of urethanes and for modifying aminoplast resins.

Abstract: Slightly crosslinked, water-soluble polymaleic acid which is obtainable by polymerization of maleic anhydride with from 0.1 to 10% by weight of a crosslinking agent in an aromatic hydrocarbon at from 60.degree. to 200.degree. C. in the presence of from 1 to 20% by weight, based on maleic anhydride, of a peroxyester, and hydrolysis of the polymer to give slightly crosslinked polymaleic acid having a Fikentscher K value of from 8 to 20 (measured at 20.degree. C. in 5% strength aqueous solution at pH 7 as the Na salt), a process for the preparation of slightly crosslinked polymaleic acid, and its use as a water treatment agent for reducing boiler scale and hard water deposits in water-conveying systems.

Abstract: A circuit board substrate of good thermal conductivity comprises a composite formed from(A) an electrically and thermally insulating plastic and(B) a plastic incorporating a thermally highly conductive filler.

Abstract: An improved fibrous polyacrylonitrile mixture for use in friction products enables the production of low resiliency preforms by mixing an additive with a polyacrylonitrile wet gel. The additive is incorporated into the fiber in extremely large amounts. The additive is a member selected from the group consisting of:(a) polyethylene glycol esters of pelargonic acid; or(b) polyethylene glycol esters of enanthic, caprylic or capric acids; or(c) blends of polyethylene glycol esters of enanthic, caprylic, pelargonic, or capric acids; or(d) blends of polyethylene glycol esters of carboxylic acids derived from natural products containing at least 50% by weight of carboxylic acids containing less than 14 carbon atoms; or(e) reaction products of ethylene oxide and carboxylic acid amides wherein at least 70% of the acids from which the amide is derived contain between 16 and 20 carbon atoms.