摘要:
Propylene homopolymers, wherein, in their separation according to tacticity by first dissolving the polymers in boiling xylene, then cooling the solution to 25° C. at a cooling rate of 10° C./h and then, with ascending temperature, separating the propylene homopolymers into fractions of different tacticity, either one or more of the conditions that i) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 112° C. is greater than 20% by weight or ii) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 117° C. is greater than 8% by weight or iii) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 122° C. is greater than 1% by weight, are satisfied.
摘要:
Propylene polymers containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C. and thereafter, increasing the temperature, separating the propylene polymers into fractions of different solubility, either one or more of the conditions that i) more than 20% by weight of the matrix remain undissolved on further heating to 112° C. or ii) more than 8% by weight of the matrix remain undissolved on further heating to 117° C. or iii) more than 1% by weight of the matrix remain undissolved on further heating to 122° C. are fulfilled by the matrix which remains undissolved on heating the cooled propylene polymer solution to 80° C., a process for the preparation of the propylene polymers, their use for the production of films, fibers or moldings and the films, fibers or moldings comprising these propylene polymers, are described.
摘要:
Catalyst systems of the Ziegler-Natta type comprise as active constituents a) a solid component comprising a compound of titanium or vanadium, a compound of magnesium, a particulate inorganic oxide as support and an internal electron donor compound, and as cocatalyst b) an aluminum compound and c) if desired, a further, external electron donor compound, wherein the particulate, inorganic oxide used has a specific surface area of from 350 to 1000 m2/g and a mean particle diameter {overscore (D)} in the range from 5 to 60 &mgr;m and comprises particles which are composed of primary particles having a mean particle diameter {overscore (d)} in the range from 1 to 10 &mgr;m and contain voids or channels between the primary particles, where the macroscopic proportion of voids or channels having a diameter of greater than 1 &mgr;m in the particles of the inorganic oxides is in the range from 5 to 30% by volume and the molar ratio of the compound of magnesium to the particulate, inorganic oxide is from 0.5:1 to 2.0:1.
摘要:
The catalyst systems comprise as active constituents a) a titanium-containing solid component comprising a compound of titanium, a compound of magnesium, a halogen, an inorganic oxide as support and a carboxylic ester as electron donor compound, and also, as cocatalyst, b) an aluminum compound and c) optionally a further electron donor compound, wherein the inorganic oxide used has a pH of from 1 to 6, an average particle diameter of from 5 to 200 &mgr;m, an average primary particle diameter of from 1 to 20 &mgr;M and voids or channels having an average diameter of from 0.1 to 20 &mgr;m and a macroscopic share of the volume of the overall particle within the range from 5 to 30%.
摘要:
A method of producing shaped articles made from single-sidedly or double-sidedly galvanized steel sheet, starting from galvanized steel strip, at least one of the steps of the method being a transport operation, and in which, for protection from black-spot corrosion, a corrosion preventive oil is applied which comprises N-acyl derivatives of sarcosinic acid as corrosion inhibitor.
摘要:
The present invention relates to the use of oxidic nanoparticles having an average particle size of 2 to 2000 nm in combination with at least one polycationic polymer as corrosion protection for metallic surfaces and also to a method of protecting metallic surfaces from corrosion, comprising the steps of: i) providing a formulation comprising oxidic nanoparticles (a) and at least one polycationic polymer (b) and an application medium, ii) applying the formulation to the metallic surface that is to be protected, and iii) optionally drying and/or heat-treating the surface.
摘要:
The surfaces of apparatuses and apparatus parts for chemical plant construction, including, for example, apparatus, container and reactor walls, discharge apparatuses, fittings, pumps, filters, compressors, centrifuges, columns, heat exchangers, dryers, comminuting machines, internals, packings and mixing elements, are coated by a process wherein protuberances having a mean height of from 100 nm to 50 &mgr;m with a mean spacing of from 100 nm to 100 &mgr;m are produced on the surface to be coated and the coating is applied thereon by currentless deposition of a metal layer or of a metal-polymer dispersion layer with the aid of a plating bath which contains a metal electrolyte, a reducing agent and optionally a polymer or polymer blend to be deposited, in dispersed form.
摘要:
Catalyst systems of the Ziegler-Natta type, which are suitable for the polymerization of olefins are prepared by: A) bringing an inorganic metal oxide on which a magnesium compound has been deposited into contact with a tetravalent titanium compound, B) if desired, bringing the intermediate obtained in this way into contact with an electron donor compound and C) bringing the intermediate obtained in step A) or B) into contact with a polysiloxane.
摘要:
The invention relates to a process for the preparation of polyalkylenepolyamines by catalyzed alcohol amination, in which(i) aliphatic aminoalcohols are reacted with one another or(ii) aliphatic diamines or polyamines are reacted with aliphatic diols or polyols with the elimination of water in the presence of a catalyst.
摘要:
Use of formulations comprising (A) one or more aminocarboxylates, selected from among methylglycine diacetate (MGDA) and its alkali metal salts and glutamic diacetate (GLDA) and its alkali metal salts, (B) at least one inorganic compound selected from among inorganic phosphates, inorganic phosphites, inorganic nitrates, ammonium salts and potassium salts and (C) optionally water for the application to plants, the ground or growth substrates.