Abstract: A catalyst, which is active in the oligomerization of olefins is an X-ray-amorphous silica-alumina-nickel oxide gel having an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of from 30/1 to 500/1, and NiO/SiO.sub.2 molar ratio of from 0.001/1 to 0.01/1, a superficial area of from 500 m.sup.2 /g to 1.000 m.sup.2 /g, and a porosity of from 0.3 ml/g to 0.6 ml/g, the means pore diameter being 1 nm (10 Angstrom), and devoid of pores having a diameter over 3 nm (30 Angstrom). The catalyst selectively dimerizes isobutene into alpha- and beta-isobutene and oligomerizes propylene into its relative dimers and trimers. A process is described for preparing the silica-alumina-nickel oxide gel.

Abstract: Disclosed is a process for carrying out the selective dimerization of isobutene in order to produce alpha- and beta-di-isobutene dimer.sub.3, according to which process an isobutene stream is brought into contact, under dimerization conditions, with a solid silica gel/alumina catalyst which is amorphous when analyzed by X-ray diffraction, displays a molar ratio of SiO.sub.2 /Al.sub.2 O.sub.3 comprised within the range of from 30:1 to 500:1, has a surface-area comprised within the range of from 500 to 1000 m.sup.2 /g, a porosity of from 0.3 to 0.6 ml/g and an average pore diameter of approximately 10 .ANG. (.ANG.ngstrom), and is free from pores with a larger diameter than 30 .ANG..

Abstract: A catalyst active in the polymerization of ethylene or the copolymerization of ethylene with unsaturated monomers consists of a nickel complex catalyst bonded to a polystyrene substrate, and definable by the general formula (I): ##STR1## where R, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 have the meanings given in the description.The preparation is described of the catalyst and its use in the polymerization of ethylene and the copolymerization of ethylene with other unsaturated monomers.

Abstract: Alkylarylethers are produced in accordance with the invention starting from phenols and ethers of aliphatic alcohols in the presence of amorphous BPO.sub.4, and calcined at a temperature of from 150.degree. C. to 600.degree. C.

Abstract: Alkylarylethers are produced according to the invention using phenols and ethers of aliphatic alcohols as the starting materials, in the presence of BPO.sub.4.

Abstract: A process for preparing 2,2-dialkyl-4-methyl-5,5-dialkyl-3-formyl-.DELTA..sup.3 -pyrrolines by reacting the corresponding dialkyl substituted di-tert-propargylamines with water at a pH equal to or less than 3.0. Preferably, an inorganic mercury compound is used as a catalyst.

Abstract: New dinitriles are prepared by reacting an alpha, beta saturated nitrile with an alpha, beta unsaturated nitrile. For this preparation subzero temperatures are preferred. Higher diamines can be prepared by hydrogenating the dinitriles thus obtained, such diamines being reacted with a dicarboxylic acid or a salt, ester or chloride of such an acid to prepare polyamides having an amorphous character, i.e. transparent polyamides.

Abstract: Polyolefin polymers can successfully be stabilized against the detrimental effects of UV-radiations by compounding them with a stabilizer belonging to the class of compounds containing a pyrrolidine ring and which are sterically hindered in the 3-position and also substituted in such position by substituents having a high molecular weight. The esters of the 2,2,5,5-tetraalkyl-4-methyl-3-methylol pyrrolidine are exemplary compounds; the adipic and the stearic esters are preferred.

Abstract: In the cyclization of gamma-delta or delta-epsilon unsaturated alcohols in order to obtain certain tetrahydrofuran and tetrahydropyran derivatives which are useful in the perfuming of detergents, the improvement consisting in that the alcohol to be cyclized is reacted with a cationic ion-exchange resin. The useful temperature range is from 20.degree. C. to 150.degree. C.: in practice the alcohol and the resin are boiled together or refluxed until the reaction is completed. A number of examples is reported and physicochemical data are given.

Abstract: New dinitriles are prepared by reacting an alpha, beta saturated nitrile with an alpha, beta unsaturated nitrile. For this preparation subzero temperatures are preferred. Higher diamines can be prepared by hydrogenating the dinitriles thus obtained, such diamines being reacted with a dicarboxylic acid or a salt, ester or chloride of such an acid to prepare polyamides having an amorphous character, i.e. transparent polyamides.

Abstract: In the cyclization of gamma-delta or delta-epsilon unsaturated alcohols in order to obtain certain tetrahydrofuran and tetrahydropyran derivatives which are useful in the perfuming of detergents, the improvement consisting in that the alcohol to be cyclized is reacted with a cationic ion-exchange resin. The useful temperature range is from 20.degree. C. to 150.degree. C: in practice the alcohol and the resin are boiled together or refluxed until the reaction is completed. A number of examples is reported and physicochemical data are given.

Abstract: In the cyclization of gamma-delta or delta-epsilon unsaturated alcohols in order to obtain certain tetrahydrofuran and tetrahydropyran derivatives which are useful in the perfuming of detergents, the improvement consisting in that the alcohol to be cyclized is reacted with a cationic ion-exchange resin. The useful temperature range is from 20.degree. C. to 150.degree. C.: in practice the alcohol and the resinare boiled together or refluxed until the reaction is completed. A number of examples is reported and physicochemical data are given.