Stamicarbon B.v.

Technische Universiteit Eindhoven

Stamicarbon B.v., Licensing Subsidiary of Dsm

Polymer Research & Development

Pieter J Lemstra

Lambert H Van Unen

Paul Smith

Antoon Dorrestijn

Cornelis W Bastiaansen

Henricus E Meijer

Rudolf J Burlet

Sanjay Rastogi

Hendrikus J Rutten

Ronald M Schellekens

Peter Paul Koets

Robert Kirschbaum

Jacques P Pijpers

Marcellus J Houben

Altug Altay

Henricus E Meyer

Johannes H Raven

Robert Marc Fifield

The present invention relates to a process for the preparation of polymer filaments having a high tensile strength and modulus by extrusion of a solution of a solvent and linear high-molecular weight polymer and subsequent spinning and quenching of the filaments thus formed, wherein after spinning and quenching the as-spun filaments are stretched under contact with steam for removing the solvent from filaments being stretched.

Process for producing high-performance polymer fibers

A method for processing ultra-high molecular weight polyethylene (UHMWPE) of at least 400,000 by heating under an elevated pressure, followed by cooling, wherein UHMWPE having a lamellar thickness <12 nm and a melting temperature at atmospheric pressure >141&deg; C. is used, by carrying out the heating under an elevated pressure via a transient hexagonal phase, which phase is represented by the hatched area in the Figure, which lies below the equilibrium line of the phase transition orthorhombic phase&mdash;liquid phase, which area is enclosed by points (P , T &prime;), (P , T &prime;), (P , T ) and (P , T ), wherein T and T represent the equilibrium temperatures associated with pressures P and P respectively, followed by heating to melting and cooling to ambient temperature.

Method for processing polyethylene having a molecular weight of at least 400,000 by heating at an elevated pressure

Novel gel-spun, irradiated and drawn ultra high strength high molecular weight and at least partially cross-linked and/or branched polyethylene filaments, tapes and films, exhibiting a combination of substantially lower creep rates, very high heat shrink characteristics and high abrasion resistance properties than corresponding but non-irradiated articles, and with a process for making the same.

Novel irradiated polyethylene filaments tapes and films and process

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.

Process for preparing polyolefin gel articles as well as for preparing

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.

Process for preparing polyacrylonitrile filaments having high tensile

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.

Process for prearing polyolefin filaments having great adhesive strength

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&gt;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.

Process for producing polyethylene articles having a high tensile

High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching. Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature. With this process low costs of solvent removal and regeneration are obtained.

Process for the preparation of polyvinyl alcohol articles of high

A continuous process is described wherein suspensions of high molecular weight polymers are readily transformed into solutions thereof for extrusion, to make gel filaments, tapes, tubes and films, by use of an extruder having alternate mixing and transporting sections and operating at mechanical shear rates of from 30 to 2,000 sec..sup.-1, and with relatively short residence times therein.

Process for the continuous preparation of homogeneous solutions of high

The invention accords to a laminate at least consisting of a first layer from a mixture of at least a propylene polymer and an ethylene-vinylalcohol copolymer and a second layer from at least one propylene polymer, the first layer at least consisting of a mixture of 60-99 parts by weight of a substantially crystalline propylene polymer and 1-40 parts by weight of an ethylene-vinylalcohol copolymer, the second layer at least consisting of a substantially crystalline propylene polymer, the said ethylene-vinylalcohol copolymer having a melting temperature at atmospheric pressure which is at most equal to and not more than 30K lower than the melting temperature at atmospheric pressure of the one of the substantially crystalline propylene polymers used having the highest melting temperature, and the laminate having been subjected to multi-axial stretching to a degree of at least twice in at least 2 directions at a temperature which at most equals the melting temperature of the one of the substantially crystalline propylene polymers used having the highest melting temperature and to a process for preparing such a laminate.

Laminates on the basis of polypropylene and process for preparing such

An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and thereafter stretching the filament thus formed. A solution of an ethylene polymer or copolymer, containing at least 80 percent by weight solvent, is spun at a temperature above the gel point of the solution. The ethylene polymer or copolymer contains at most about 5 percent by weight of an alkene having 3 to 8 carbon atoms, has a weight-average molecular weight Mw higher than 4.times.10.sup.5 kg/kmole, and has a weight/number average molecular weight ratio Mw/Mn lower than 5. The spun polymer solution is thereafter cooled to a temperature below its gel point to form a gel filament, which gel filament is thereafter stretched to form a polymer filament having a tensile strength of at least about 1.5 GPa at room temperature.

Process for the production of polymer filaments having high tensile

New rigid polyvinyl chloride foam having a density of less than 200 kg/m.sup.3 and having a uniform, fine-celled cell-structure consisting of a rigid vinyl chloride homopolymer containing per 100 parts by weight of polyvinyl chloride 0.1-15 parts by weight of a homo- or copolymer of an alkyl methacrylate having an alkylgroup of 1-10 carbon atoms having a viscosity of the solution .eta..sub.0.1 of between 1.times.10.sup.-6 and 4.times.10.sup.-6 m.sup.2 /s measured at 293 K in 1,2 dichloro ethylene and a method for the preparation of such a new rigid polyvinyl chloride foam.

Rigid polyvinyl chloride foam

The invention relates to the preparation of filaments with a high tensile strength and a high modulus and to the filaments thus prepared. A solution of a linear polyethylene with a weight-average molecular weight of at least 4.times.10.sup.5 is spun and the filaments, from which the solvent may have been removed in whole or in part, are drawn using a draw ratio of at least (12.times.10.sup.6 /M.sub.w)+1. The filaments are drawn at a temperature such that the modulus is at least 20 GPa. The invention allows filaments to be prepared at high drawing rates, of 0.5 sec.sup.-1 or more, with a modulus of at least 20 GPa and a tensile strength of at least 1 GPa.

Filaments of high tensile strength and modulus

New rigid polyvinyl chloride foam having a density of between 10 and 50 kg/m.sup.3 and having a uniform, fine-celled cell-structure consisting of a rigid vinyl chloride homopolymer containing per 100 parts by weight of polyvinyl chloride 0.1-15 parts by weight of a homo- or copolymer of an alkyl methacrylate having an alkyl group of 1-10 carbon atoms and a method for the preparation of such a rigid polyvinyl chloride foam.

Growing community of inventors

Brunssum, Netherlands

Pieter J Lemstra