Abstract: A compound of formula (X): wherein R1, R2, equal to or different from each other are hydrogen or a linear or branched saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C20-alkylaryl or C7-C20-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or they can form a C4-C7 ring optionally containing O, S, N, P or Si atoms that can bear substituents; R3 is hydrogen or a linear or branched saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C20-alkylaryl or C7-C20-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or two adjacent R3 groups can form a C4-C7 ring optionally containing O, S, N, P or Si atoms, wherein said ring can bear substituents; and at least one of R1, R2 or R3 is different from hydrogen.

Abstract: A process for the production of dish-shaped moldings or hollow bodies of thermoplastic material comprises the step of producing an at least approximately tubular preform by the extrusion of thermoplastic material. The preform is axially divided to form at least one single-layer web of material which is removed from the extrusion head by being engaged by means of a manipulator which spreads and/or straightens the web transversely with respect to the extrusion direction. The web is then transferred to a molding tool by a manipulator for it to be put into its final form in its first heat in the molding tool.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH2?CHR in which R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, comprising Mg, Ti, halogen and an electron donor selected from substituted succinates of a particular formula. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: A process for the production of dish-shaped moldings or hollow bodies of thermoplastic material comprises the step of producing an at least approximately tubular preform by the extrusion of thermoplastic material. The preform is axially divided to form at least one single-layer web of material which is removed from the extrusion head by being engaged by means of a manipulator which spreads and/or straightens the web transversely with respect to the extrusion direction. The web is then transferred to a molding tool by a manipulator for it to be put into its final form in its first heat in the molding tool.

Abstract: In that process for the production of hollow bodies from thermoplastic material by extrusion blow molding in which discontinuously extruded preforms are expanded in a blow molding mold, at least during that part of the filling phase which is typical of such a process, for an extrusion head, the distance covered by an ejection piston associated with a storage chamber and the speed at which the ejection piston is displaced within the storage chamber by the plasticised material are detected and compared by a central control and regulating device to the respective reference values. On the basis of the result of the comparison operation at least one operating parameter of the process, for example the delivery output of the extruder or the extent of the emptying strike movement of the ejection piston can then be adapted while still in the same working cycle in such a way that substantially the required preform volume is ejected.

Abstract: An apparatus for the production of hollow bodies from thermoplastic material by blow molding using a blow molding mold which includes at least first and second mold portions to enclose a generally tubular extruded preform which is expanded within the mold under the effect of an increased internal pressure within the preform. To provide for asymmetric closing and/or opening movements of the mold portions relative to the preform, the blow molding mold is displaced as an entirety parallel to the direction of the opening and/or closing movements of the mold portions, more especially during the mold closing and/or opening procedure, so that an additional motion is superimposed on the movements of the mold portions.

Abstract: A process and apparatus for the production of hollow bodies from thermoplastic material by means of blow molding uses a blow molding mold which includes at least first and second mold portions to enclose a generally tubular extruded preform which is expanded within the mold under the effect of an increased internal pressure within the preform. To provide for asymmetric closing and/or opening movements of the mold portions relative to the preform, the blow molding mold is displaced as an entirety parallel to the direction of the opening and/or closing movements of the mold portions, more especially during the mold closing and/or opening procedure, so that an additional motion is superimposed on the movements of the mold portions.

Abstract: In a process and apparatus for the discontinuous production of preforms for producing hollow bodies from thermoplastic material, the wall of which is a laminate having at least first and second layers, by extrusion blow molding, the flow of material for forming the laminate is guided within the extrusion head which serves to produce the preforms, by suitable dimensioning of the volume of the duct system accommodating the laminate, such that regions of disturbed laminate occur in the end portions of the preform which are squeezed off the extruded preform by the blow molding mold as a waste portion.

Abstract: In a process and apparatus for the production of hollow bodies from thermoplastic material, having a wall of a laminate formed by at least first and second layers, by means of extrusion blow molding, a preform having a wall structure with a suitable number of layers is first produced in a batch-wise procedure using an extrusion head. The material required to produce the preform is guided in the extrusion head in such a way that disturbed portions of the laminate pass into the waste flash portions at the ends of the hollow body produced from the preform, so that the wall of the finished hollow body is devoid of disturbed laminate portions of that kind.

Abstract: In a process and apparatus for the production of hollow bodies from thermoplastic material, the walls of the hollow bodies are of a laminate structure having at least first and second layers, by means of extrusion blow molding, the pressure within the extrusion head and more particularly at the location at which the laminate is formed by the discharge of flows of material from a storage chamber in the head is maintained within limits such as to avoid disturbing the laminate to such an extent as to have an adverse effect on its function. The pressure at the time of a transition between filling and emptying of the storage chamber and between emptying and filling of the storage chamber is maintained substantially at a pressure level which approximately corresponds to the storage chamber emptying pressure.

Abstract: A barrel of thermoplastic material has at least one connecting portion having an emptying opening and arranged in a trough-like depression in the upper end part of the barrel. In the region of the connecting portion the barrel has at least one inclined surface which extends between the upper end part of the barrel and the side wall of the barrel. The inclined surface is of such a configuration that in a barrel emptying position the emptying opening forms the lowest part of the interior of the barrel to permit at least almost complete emptying of the barrel.

Abstract: A moulding apparatus having a two-part mould movable between a receiving station at which thermoplastics synthetic material is extruded into the mould and a release station at which a moulded hollow body is removed from the mould. This hollow body is then supported by a blowing and calibrating member before being gripped by a two-part gripper which moves the body from the release station to a transfer station in synchronism with the mould movement. The gripper parts are mounted on arms or levers supporting and/or guiding the mould parts.

Abstract: A moulding apparatus having a two-part mould movable between a receiving station at which thermoplastics synthetic material is extruded into the mould and a release station at which a moulded hollow body is removed from the mould. This hollow body is then supported by a blowing and calibrating member before being gripped by a two-part gripper which moves the body from the release station to a transfer station in synchronism with the mould movement. The gripper parts are mounted on arms or levers supporting and/or guiding the mould parts.

Abstract: A closure adapted to be applied to a neck of a vessel or container so as to seal a comparatively wide mouth in said neck has a rim or skirt which is divided up into a plurality of sections by slits between the sections depending from a lid portion of the closure and a stressing or tensioning band placed around the rim, the arrangement being such that there is at most only slight engagement between corresponding screw threads or the like on the neck and in the skirt when the closure is applied to the neck, full sealing engagement between the said screw threads being produced by tensioning of said band after the closure is in position on the neck, such tensioning causing the initially radially outwardly splayed said sections to be pulled radially inwardly on to the neck. The vessel and closure are preferably of thermoplastic material.