摘要:
A continuous process for the production of polycarboxylic acids or salts thereof from polysaccharides involving contacting a polysaccharide with an oxidizing agent selected from the group consisting of nitrogen dioxide, dinitrogen tetroxide, or an equilibrium mixture thereof in the absence of oxygen at a temperature above 80 .degree.C. and at a pressure of from about 3 bar to about 15 bar absolute and for a tirne period of from about 1 to about 30 minutes to form a reducd gaseous product and a polysaccharide product wherein the primary alcohol groups of said polysaccharide product are at least partially converted to carboxyl groups.
摘要:
A process for producing polycarboxylic acids or salts thereof by contacting a polysaccharide with nitrogen dioxide and dinitrogen tetroxide at a charging temperature in the range from the boiling point of nitrogen dioxide under a particular pressure to a temperature which is 50.degree. C. higher than said boiling point, oxidizing the primary alcohol groups of the polysaccharide at a temperature which is at least about 10.degree. C. above said charging temperature to convert the primary alcohol groups into carboxyl groups, and optionally, at least partially neutralizing the carboxylic acid groups formed.
摘要:
Poly-N-acylalkyleneimines corresponding to the following formula ##STR1## are used as an oxidatively crosslinking constituent in paints. In formula (I), R--CO represents the acyl radical of a mono- or polyunsaturated, aliphatic C.sub.16-22 carboxylic acid or a mixture of such radicals, R'--CO represents the acyl radical of a C.sub.1-22 carboxylic acid or a mixture of such radicals and x and y represent the percentages by weight of the particular polymer units, x assuming values of 20 to 100% and preferably 20 to 95% and y assuming values of 80 to 0% and preferably 80 to 5%. The indices m and n independently of one another may assume the value 2 or 3.
摘要:
The invention relates to moldable, radically polymerizable multicomponent mixtures, which may even be present in the form of storable multicomponent systems, containingethylenically unsaturated, polymerizable compounds, if desired in admixture with soluble and/or insoluble fillers and/or other auxiliaries, andan activator system initiatable by contact with oxygen,characterized in that, in their in-use form, the multi-component mixtures are present as at leastly slightly thickened material and contain an activator system based on the following principal components which can be initiated by contact with ambient air:N-alkyl-substituted tert.-arylamines containing at least one aliphatic CH bond in the .alpha.-position,metal compounds at least partly soluble in the system to accelerate the drying of unsaturated oils, andweakly acidic carboxylic acids having pK.sub.s values no lower than about 0.9.In their in-use form, the multicomponent mixtures preferably have a minimum viscosity of at least about 50 to 100 mPa.s. The invention also relates to the use of the activator systems of these mutlicomponent mixtures for the time-controlled hardening--with a predeterminable pot-life--of olefinically unsaturated systems by contact with ambient air at room temperature or only moderately elevated temperatures.
摘要:
The invention relates to moldable, radically polymerizable multicomponent mixtures containingethylenically unsaturated, polymerizable compounds, if desired in admixture with soluble and/or insoluble fillers andan activator system initiatable by contact with oxygen,and is characterized in that these multicomponent mixtures contain an activator system based on the following principal components which can be initiated by contact with oxygen and water and, in particular, by contact with ambient air:N-alkyl-substituted tert-arylamines containing at least one aliphatic CH bond in the .alpha.-positionmetal compounds at least partly soluble in the system to accelerate the drying of unsaturated oils andcompounds of weakly acidic carboxylic acids having pK.sub.a values of no less than about 0.9 which can be hydrolyzed to the free carboxylic acid on contact with moisture.The invention also relates to the use of these multicomponent mixtures as an aerobic adhesive system, more particularly in the form of a one-component adhesive packed in storable form, and to their use for surface coating or for the production of plastic moldings.
摘要:
Poly-N-acylalkyleneimines corresponding to the following formula ##STR1## are used as an oxidatively crosslinking constituent in paints. In formula (I), R--CO represents the acyl radical of a mono- or polyunsaturated, aliphatic C.sub.16-22 carboxylic acid or a mixture of such radicals, R'--CO represents the acyl radical of a C.sub.1-22 carboxylic acid or a mixture of such radicals and x and y represent the percentages by weight of the particular polymer units, x assuming values of 20 to 100% and preferably 20 to 95% and y assuming values of 80 to 0% and preferably 80 to 5%. The indices m and n independently of one another may assume the value 2 or 3.
摘要:
Alkyd resins useful in forming stoving lacquers, containing the reaction product of a polybasic carboxylic acid or reactive derivative thereof and a polyhydric alcohol which is itself the reaction product of an epoxidized fatty acid ester, fatty acid amide or fatty alcohol and an alcohol or phenol, and, optionally, a monofunctional modifying agent.
摘要:
In the Claus process for the production of sulfur a gas stream containing ammonia and hydrogen sulfide is treated to form a gas containing hydrogen sulfide and virtually no ammonia and a second gas which contains ammonia and is virtually free from hydrogen sulfide. The two gases are separately burned in the same Claus furnace with oxygen. To produce the gas virtually free from ammonia, a partial stream of the gas containing ammonia and hydrogen sulfide is scrubbed with water with the ammonia being recovered from the water.
摘要:
A longitudinal beam for a driver's cab which extends upward in an angular manner beyond a floor plate. An essentially straight longitudinal beam section is assembled with a separate longitudinal beam head.
摘要:
A hydrophilic, high molecular weight nonionic polyurethane, characterized by solubility in water and by a specific viscosity of at least 0.4 (1% by weight solution at 20° C.) is provided. Examples of such polyurethanes are those characterized by the following structural units: a) —O(—CH2—CH2—O)n—, where n=8 to 500, and b) —CO—NH—X—NH—CO—, where X is an aliphatic or cycloaliphatic radical. Also provided are methods of using the polyurethane as an adhesive, more particularly a hotmelt adhesive or a solvent-based adhesive, for example a wallpaper adhesive and labelling adhesive, of using polyurethane as a stabilizer in the emulsion polymerization of, in particular, vinyl acetate and vinyl chloride and in the copolymerization of ethylene and vinyl acetate, and of using the polyurethane as a thickener for aqueous systems, more particularly together with nonionic surfactants.