Abstract: A process is described for the preparation of highly stretchable high-molecular weight polyolefin gel articles and polyolefin gel articles prepared therefrom having combined high tensile strength and high modulus, wherein an initial shaped article of the polyolefin is exposed to or contacted with a swelling agent to form an intermediate swollen article, which is then converted to the gel state and then subsequently subjected to stretching at up to relatively high draw ratios.

Abstract: The invention relates to polyethylene compositions comprising 20-98 wt. % branched polyethylene (a) with a density of between 915 and 940 kg/m.sup.3 and a melt flow index of between 0.05 and 40 dg/minute, prepared by a high pressure radical process, and 2-80 wt. % substantially linear polyethylene (b) with a density of between 850 and 915 kg/m.sup.3, a melt flow index of between 0.05 and 25 dg/minute and a DSC crystallinity at 23.degree. C. of at least 10%, prepared with the aid of a transition metal catalyst, the difference between the highest crystallization temperature of branched polyethylene (a) and the highest DSC crystallization temperature of linear polyethylene (b) being at most 10.degree. C. and the mixture having a modulus of elasticity of at most 280 N/mm.sup.2 and objects made therefrom. These polyethylene compositions, when processed to foamed objects, have a high resistance to high temperatures as well as a high flexibility.

Abstract: A thermal transfer medium which has a heat meltable or heatsublimable ink layer on one side of a stretched polyamide film which mainly consists of polytetramethylenediapamide and has a melting point of at least 270.degree. C. The film shows good heat resistance and nonsticking properties.

Abstract: The invention relates to a process for preparing cyclohexanol and/or cyclohexanone, in which cyclohexene in a feed stream containing cyclohexene, cyclohexane and benzene is hydrated into cyclohexanol and/or oxidized into cyclohexanone, the cyclohexanol and/or cyclohexanone formed is separated from the reaction mixture thus obtained and the remaining cyclohexane and benzene are recycled to a preconnected cyclohexene preparation section, part of the stream that is recycled to the cyclohexene preparation section being subjected to a dehydrogenation reaction and the remaining part to a hydrogenation reaction, and the reaction streams thus obtained being combined to form the feed stream to the hydration and/or oxidation step.

Abstract: The invention relates to a thermoplastic moulded printed circuit board consisting substantially of polyamide 4.6. Preferably use is made of a multilayer structure, of which at least one layer contains reinforcing filler material.

Abstract: The invention relates to a process for the preparation of a thermoplastic polymer on the basis of an alkenyl aromatic monomer, an unsaturated dicarboxylic anhydride, and, optionally, a rubber, characterized in that the monomers and/or solution thereof are/is reacted in at least two reaction zones that are in open connection with each other at the top and at the bottom, the reaction mixture being circulated through the reaction zones by means of a mixing device and/or a conveying device.Using the process, a homogeneous product of constant composition is obtained.

Abstract: Catalyst system, suitable for the (co)polymerization of ethylene and optionally minor amounts of 1-alkenes and/or dienes at such temperatures that the copolymer formed goes into solution, to be prepared by combining at least two components A and B, which components comprise:A: one or more magnesium compounds, one or more aluminium compounds, one or more transition metal compounds and optionally one or more halogen compounds, in such amounts that the atomic ratio of halogen to magnesium is at least 2, the atomic ratio of aluminium to transition metal is at least 3, the atomic ratio of aluminium to magnesium is at least 1, and the atomic ratio of magnesium to transition metal is at least 0.5,B: one or more organoaluminium compounds of the general formula R.sub.m.sup.1 Al X.sup.1 3-m, where the symbols R.sup.1 are equal or different and represent a hydrocarbon residue with 1-20 carbon atoms and the symbols X.sup.1 are equal or different and represent a hydrogen atom, a group of the general formula --NR.sup.

Abstract: Polyacrylonitrile articles, such as filaments, tapes and films, having high tensile strength and modulus, and prepared by adding to a solution of polyacrilonitrile with a molecular weight above 3.times.10.sup.5, preferably above 5.times.10.sup.5, a minor amount of a bivalent metal compound, converting the solution into a solvent containing article, cooling this article to form a gel article, removing from this gel the solvent and metal compound, and stretching the resulting article at increased temperature. With this process filaments with a tensile strength above 1.2 GPa and a modulus above 16 GPa can be obtained.

Abstract: The adhesive strength of highly oriented, highmolecular polyolefin filaments for polar polymeric matrices is improved by subjecting the filaments to a corona treatment with a total irradiation dosage of ##EQU1## effected intermittently in several smaller dosages. The process is particularly suited for treating superstrong polyethylene fibers, and making reinforced materials while applying as matrix a polyester, polyamide or epoxy resin.

Abstract: The invention relates to a skin-shaped product comprising an aminoplast-formaldehyde resin mixture and fibrous material and is characterized in that the resin mixture has a viscosity of 25 Pa.s-15.10.sup.3 Pa.s at 120.degree. C. in the skin-shaped product and that the fibrous material in the form of a fleece or a mat has a strength of 0.1 MPa-20 MPa at 20.degree. C.

Abstract: High strength and modulus articles, such as filaments, fibers, tapes, films, tubes, bars or profiles, are prepared by irradiating a solid, particular, lamellar, disentangled polyethylene with a Mw>4.times.10.sup.5, transforming this polyethylene above the melt temperature into an article, cooling said article to below the melting point and stretching it in several steps at rising temperature but below the melting point of the article.Advantages are i.a. the lower costs compared with the known processes, such as solid state extrusion or thermoreversible gelation.

Abstract: Thermoplastic polymer mixture with a high surface gloss on the basis of:a 50-95 wt. % ofa.1 20-90 wt. % of a copolymer of styrene and/or .alpha.-methyl-styrene with acrylonitrile with an acrylonitrile content of 18-27 wt. %, the copolymer having a fluidity of 3-20;a.2 5-60 wt. % of a copolymer of styrene and .alpha.-methyl-styrene with acrylonitrile with an acrylonitrile content of 25-40 wt. %, the copolymer having a fluidity of at least 25;a.3. 0-30 wt. % of a polyacrylate compound;b 5-50 wt. % ofb.1 a substantially saturated rubber andb.2 chlorinated polyethylene.The thermoplastic polymer mixture not only has a high surface gloss, but also the flow of the mixture has been improved substantially. As a result, the mixture has excellent processing characteristics.

Abstract: The invention relates to a process for preparation of L-.alpha.-amino acid and D-.alpha.-amino acid amide from DL-.alpha.-amino-acid amide by contacting the DL-.alpha.-amino acid amide in an aqueous solution with an .alpha.-amino acid amidase containing preparation obtained from a culture of Pseudomonas putida in the presence of traces of bivalent metal ions as activator, characterized in that the aqueous solution also contains a potassium salt selected from the group consisting of potassium sulphate and potassium chloride.The invention further relates to a process for the preparation of L-.alpha.-amino acid and D-.alpha.- amino acid amide starting from the corresponding aldehyde, potassium cyanide and ammoniumsulphate, subsequent treatment with a ketone and potassiumhydroxide and finally subjecting to enzymatic hydrolysis with a preparation obtained from Pseudomonas putida.

Abstract: The invention relates to a process for preparing a 2-alkyl-1,4,5,6-tetrahydropyrimidine with the formula ##STR1## where R represents a straight or branched chain with 1-8 C-atoms or a phenyl group from 1,3-diaminopropane and an alkanecarboxylic acid, in which the alkyl group of such an acid is the same as the R group described above, wherein the starting materials are reacted in the gas phase in the presence of an oxide catalyst at a temperature of between 250.degree. and 450.degree. C. and from the reaction mixture thus obtained the 2-alkyl-1,4,5,6-tetrahydropyrimidine is recovered.

Abstract: The invention relates to aromatic polyesters containing units with two carbonyl groups and having liquid crystalline properties. The aromatic polyesters are characterized in that the polyesters contain heterocyclic units with two carbonyl groups. Preferably these units are derived from furandicarboxylic acid. The aromatic polyesters show a considerable reduction in melting temperature, rendering the polyester more processable.

Abstract: The invention relates to a polyamide composition with improved stability in contact with oil at elevated temperatures. The polyamide composition with superior stability characteristics has been obtained by the incorporation in the polyamide composition of a small amount of an alkaline inorganic material. Preferably the polyamide is nylon 4.6.

Abstract: The invention relates to a process for the preparation of a thermoplastic consisting of a vinylaromatic compound, acrylonitril and a butadiene rubber, by means of a two-step polymerization reaction characterized in that 0.1-10 wt. % of the butadiene rubber based on the entire composition, is replaced by an acrylate rubber in the second step. The process results in a decreased concentration of residual monomers.

Abstract: The invention relates to a novel grade of copolymides of tetramethyleneadipamide (nylon 4.6) and tetramethyleneterephthalamide (nylon 4.T) containing a mole fraction nylon 4.T of 0.1 to 0.6 and having such a degree of orientation that the melting temperature shows little dependence on the composition of the copolyamide and remains relatively low and which copolyamides have good mechanical properties.

Abstract: An improved process and apparatus for the concentration of an aqueous urea solution by evaporation of water in a single pass shell and tube heat exchanger having a substantially vertical tube bundle within the shell. The aqueous urea solution is introduced into the top of the vertical tube bundle and caused to fall as a film down the inside of said tubes whereby it is heated and water evaporated therefrom to form a concentrated urea solution. The heat for this evaporation is provided by condensing at least a part of a gas mixture containing NH.sub.3, CO.sub.2 and H.sub.2 O in the shell side of the heat exchanger. This gas mixture is introduced into a lower portion of the shell wherein it is caused to flow upwardly in shell in contact with said tube bundle, counter-current to the flow of the aqueous urea solution within the tubes whereby heat from said condensation is transferred to said aqueous urea solution flowing down the inside of the tubes.