Polyethylene composition with high degree of swelling

FIELD: chemistry.

SUBSTANCE: invention relates to a polyethylene composition for making moulded articles of different types. Composition has density from 0.953 to 0.960 g/cm3 and ratio of MIF/MIP from 17–29, where MIF is melt flow index at 190 °C with load of 21.60 kg, and MIP is melt flow index at 190 °C with a load of 5 kg. Composition is obtained by polymerisation of ethylene, optionally together with one or more comonomers, in a gas phase reactor in presence of hydrogen and copolymerisation of ethylene with one or more comonomers in other gas-phase reactor in presence of a lower amount of hydrogen, than at step a). In at least one of said gas-phase reactors growing polymer particles flow upward through a first polymerisation zone under fast fluidisation or transfer conditions, come out of said zone, and enter a second polymerisation zone, through which they flow down by gravity, come out of said second polymerisation zone and reenter first polymerisation zone, creating circulation of polymer between polymerisation zones. All copolymerisation steps are carried out in presence of a Ziegler-Natta polymerisation catalyst deposited on MgCl2. Polyethylene composition contains one or more copolymers of ethylene and not more than 1 wt% of comonomer, selected from olefins of formula CH2=CHR, where R is alkyl radical, linear or branched, containing from 1 to 10 carbon atoms.

EFFECT: obtained composition is characterised by good balance of physical and mechanical properties, high degree of swelling of extruded flow with surface of high quality and stability of dimensions of end product, environmental stress-cracking resistance (FNCT) and impact strength.

4 cl, 1 dwg, 1 tbl

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to a multimodal polyethylene resin, an extrusion composition, containing it, and products, which can be used for manufacturing extrusion coatings, extrusion profiles and films.

EFFECT: extrusion composition contains the multimodal polyethylene resin and from 2 to 20 wt % of a polyethylene low density resin, and is characterised by high rates of a technological line, high resistance to resonance in the process of the extrudate drawing and essentially reduced degree of necking.

9 cl, 5 dwg, 10 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: group of inventions relates to polyethylene compositions for films or cast products. Composition has melt fluidity index at 5 kg/190°C (MI5 kg) from 0.25 to 3 g/10 min, Mz higher than 2000000 g/mol and lower than 370000 g/mol and Hostalen index (HI) value from 0.18 to 18. When melt fluidity index at 5 kg/190°C (MI5 kg) is higher than 1.9 g/10 min, Hostalen index (HI) value is higher than 1.

EFFECT: polyethylene composition in accordance with invention, possessing specified molecular-weight distribution and long-chained branched structure, possesses improved technological properties, and obtained films have higher mechanical impact strength with film thickness being 10 mcm than at 20 mcm, in accordance with measurement of dart drop impact (DDI).

9 cl, 4 tbl, 8 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of increasing homogeneity of mixtures of polyethylene, intended for manufacturing moulded products, films, tubes, wires and cables. A mixture of polyethylenes contains three fractures (A), (B) and (C) of a homo- or a copolymer of ethylene and at least one comonomer C3-C10 with different molecular weights. The low-molecular fraction A) has the weight-average molecular weight Mw lower than 40 kg/mol, the highly-molecular fraction B) has the molecular weight Mw higher than 250 kg/mol and the fraction C) has the intermediate molecular weight with the weight-average molecular weight Mw from 100 to 200 kg/mol. The mixture of polyethylenes has a single peak of melting as determined by means of differential scanning calorimetry (DSC).

EFFECT: obtained mixtures of polyethylenes, due to the improved homogeneity, possess improved properties, in particular surface properties, good processability and good mechanical properties.

16 cl, 9 dwg, 4 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to pipe, possessing increased resistance to growth of pipe cracks and manufactured from polyethylene composition, as well as to application of phenol type stabiliser (C) and phenol type stabiliser (D) to increase resistance of pipes to slow crack growth. Pipe consists of polyethylene composition, which includes basic resin and phenol type stabilisers (C) and (D), which are different. Stabiliser (C) contains, at least, one ester group, and stabiliser (D) does not contain any ester group. Basic resin of polyethylene composition contains first ethylene homo- or copolymer (A) and second ethylene copolymer (B), with comonomer(s) for copolymer (B) and, possibly, copolymer (A) representing C3-C20 alpha-olefins.

EFFECT: pipes in accordance with invention have stability in testing whole cut for creep (FNCT), measured in accordance with ISO 16770:2004, at least, 5000 h.

11 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a polyethylene moulding composition intended for making pipes, conduits and cables, and a method of producing said composition. The composition has a multimodal molecular-weight distribution, density in the range of 920 to 960 kg/m3, melt flow index MFI190/2 in the range of 0.05 to 10 g/10 min and Shore hardness D, measured according to ASTM D2240-05 (15 s), of at least 56.0. The composition contains at least three ethylene polymer fractions having different molecular weight. Each of the fractions A, B and C is an ethylene homopolymer or a copolymer of ethylene with at least one C3-C10 comonomer.In the composition, one of the fractions A, B and C is an ethylene homopolymer and at least one of the other fractions is an ethylene copolymer with content of said C3-C10 comonomer of 1-15 wt %. Fraction A has weight-average molecular weight Mw in the range of 15 to 40 kg/mol, fraction B - in the range of 70 to 200 kg/mol and fraction C - in the range of 220 to 400 kg/mol.

EFFECT: obtained polyethylene moulding composition has excellent mechanical properties, hardness and wear resistance, and also has high impact resistance and slow crack growth.

13 cl, 6 dwg, 6 tbl

FIELD: chemistry.

SUBSTANCE: method includes stages of mixing an acid-based polymer, a neutralisation agent and a technological additive to obtain a polymer composition. In the process of mixing a level of the acid-based polymer neutralisation constitutes from 25% to 75%. After processing the said polymer composition a polymer fabric, which is granulated into polymer particles, is obtained. The acid-based polymer represents resin with the melt flow index, measured at 190°C under a load of 2.16 kg, from 10 to 60 g/10 min, with the neutralisation agent being selected from the group, consisting of potassium hydroxide, aluminium hydroxide, calcium hydroxide, zinc oxide or their mixtures, salt of metal and fatty acid and a partly or completely neutralised ionomer or their mixtures.

EFFECT: polymer coatings possess a low negative impact on the environment, evaluated by indices of life cycle evaluation.

26 cl, 1 dwg, 10 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a colourless synthetic binding agent, which is applied in the road-industrial area. The colourless synthetic binding agent contains oil of a vegetable origin, resin of a petroleum origin and a polymer. The quantity of oil of a vegetable origin in the binding agent constitutes 10 wt % or more, and the quantity of the polymer in the binding agent constitutes 15 wt % or less.

EFFECT: colourless synthetic binding agent in accordance with invention possesses good consistency, reduced viscosity, acceptable behaviour at low temperature and acceptable elastic properties.

18 cl, 7 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to hot-melt adhesives. The hot-melt adhesive contains 5-40 wt % of a copolymer based on ethylene and C3-C20 α-olefin, which is obtained by metallocene-catalysed polymerisation, 10-65 wt % of tackifying resin, 0-35 wt % of a plasticiser and 0.01-30 wt % of additives. The additives are selected from stabilisers, adhesion promoters, fillers or pigments, waxes and/or other polymers, wherein the total amounts to 100%. The copolymer is a block copolymer having invariable elastic properties in the range of 0°C to 25°C, measured as a ratio of the storage modulus E′ according to (E'0C-E'25C)/E'25C<1.5.

EFFECT: method improves process properties of the hot-melt adhesive while preserving mechanical properties in the temperature range to 50°C.

18 cl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a PVC-free floor or wall covering comprising at least one layer of a thermoplastic composition. The composition contains a polymer matrix comprising at least two polymers and at least 100 pts.wt of least one filler per 100 pts.wt of the polymer(s). Said matrix contains 10-40 pts.wt of a polymer with carboxylic acid anhydride groups in amount of 0.5-3.1 wt %, and the other polymer of the matrix is selected from a group comprising EVA, EMA, EBA, EEA, EPM, EPDM, VLDPE, LLDPE, POE, POP and mixtures thereof, and has melt flow index between 0.6 and 3 g/10 min at 190°C and mass of 2.16 kg. The total amount of combined polymers in the composition is 100 pts.wt.

EFFECT: floor or wall covering obtained according to the invention preferably in form of rolls or tiles has improved residual indentation properties and is also suitable for recycling.

14 cl, 7 dwg, 9 tbl

FIELD: chemistry.

SUBSTANCE: coating comprises an adhesive sublayer of a thermoplastic adhesive and a functional layer of a nanostructured composite material based on polyethylene. The composite material of the functional layer has a polyethylene matrix and montmorillonite particles dispersed in the matrix in amount of 0.1-2 wt %.

EFFECT: improved physical and mechanical properties of the coating.

12 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to production of a polyolefin oxygen-absorbing composition for making sealing pads for sealing polymer and glass bottles with liquid foodstuffs. A method of producing a polyolefin oxygen-absorbing composition for sealing pads by mixing, in a melt, a mixture of high-pressure polyethylene with a copolymer of ethylene and vinyl acetate with a melt flow index in the range of 5-10 g/10 m and weight ratio of vinyl acetate in the range of 10-14%, target additives and sodium sulphite as an oxygen absorbent in amount of 3.6-6.0 wt %. Sodium sulphite with average particle size of 70 mcm is added to the composition in the form of a melt-derived granular polymer concentrate based on a copolymer of ethylene and vinyl acetate with a melt flow index in the range of 5-15 g/10 min and weight ratio of vinyl acetate in the range of 10-17%, containing 20-40 pts.wt sodium sulphite and 79-59 pts.wt ethylene and vinyl acetate copolymer.

EFFECT: invention improves oxygen absorption efficiency.

4 tbl, 12 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an elastomeric composition with a biodegradability degree below 50%, preferably below 30%, which comprises at least 0.5% and at most 99.95 wt % acetate of a starchy material, having a degree of substitution (DS) between 2.5 and 3 and, at least, 0.05 wt % and at most 99.5 wt % of a polymer other than starch, where the polymer is selected from a group comprising natural rubber and its derivatives, polyisobutylenes, polyisoprenes, styrene-butadiene copolymers (SBR), butadiene-acrylonitrile copolymers, hydrogenated butadiene-acrylonitrile copolymers, acrylonitrile-styrene-acrylate copolymers (ASA), ethylene-methyl acrylate copolymers (EAM), thermoplastic polyurethanes (TPU) in the form of simple ethers or in the form of a compound ether-simple ether, polyethylene or polypropylene, functionalised with halogenated silane, units of acrylic or maleic anhydride, ethylene-diene monomer rubber (EDM) and ethylene-propylene-diene monomer rubber (EPDM), thermoplastic elastomers, derived from polyolefines (TPO), styrene-butylene-styrene copolymers (SBS) and styrene-ethylene-butylene-styrene copolymers (SEBS), functionalised with units of maleic anhydride, and other blends of the above polymers. The composition may be used as a masterbatch or a matrix of the masterbatch, a plastic raw material, a compound for plastic or elastomeric articles, an adhesive, especially of a hot-melt type, or a matrix for the formulation of an adhesive, in particular of a hot-melt type, as a gum base or a matrix of the gum base, in particular for chewing gum, resin, co-resin or nanofiller for rubber, elastomers, bitumens, printing ink, varnish, paint, paper and cardboard, woven and non-woven products or thermosetting resins. It may also be used for the production of parts of equipment for the transport industry, in particular the automotive, aeronautical, railroad or ship building industry, for the electrical appliance, electronic appliance or electrical household appliance industries or for the sports and leisure industry.

EFFECT: compositions with low or very low biodegradability, long term high stability in water.

20 cl, 3 tbl

FIELD: chemistry.

SUBSTANCE: group of inventions relates to polyethylene compositions for films or cast products. Composition has melt fluidity index at 5 kg/190°C (MI5 kg) from 0.25 to 3 g/10 min, Mz higher than 2000000 g/mol and lower than 370000 g/mol and Hostalen index (HI) value from 0.18 to 18. When melt fluidity index at 5 kg/190°C (MI5 kg) is higher than 1.9 g/10 min, Hostalen index (HI) value is higher than 1.

EFFECT: polyethylene composition in accordance with invention, possessing specified molecular-weight distribution and long-chained branched structure, possesses improved technological properties, and obtained films have higher mechanical impact strength with film thickness being 10 mcm than at 20 mcm, in accordance with measurement of dart drop impact (DDI).

9 cl, 4 tbl, 8 ex, 1 dwg

Sealing mastic // 2542293

FIELD: chemistry.

SUBSTANCE: sealing mastic contains, wt %: chlorobutyl rubber - 3.6-4.2, ether of glycerol tall oil rosin - 1.0-1.5, high pressure polyethylene in the form of a film - 0.3-0.4, zinc borate - 4.0-4.6, magnesium hydroxide - 6.0-7.0, aluminium hydroxide - 22.0-12.0, trichloropropylphosphate - 2.5-3.0, a barite concentrate - 48.0-51.0, chloroparaffin CP-470 - 1.8-2.0, PN-6sh oil - 7.0-8.0.

EFFECT: invention makes it possible to increase soundproofing, vibration damping, adhesion properties and ecological safety.

1 tbl

FIELD: chemistry.

SUBSTANCE: non-drying rubber mixture contains, wt %: butyl-rubber regenerate from waste diaphragm chambers - 17.0-31.0, ether of glycerol tall oil rosin - 0.5-1.0, PN-6sh oil - 20.0-25.0, chalk - 10.0-45.0, high-pressure polyethylene in the form of a film - 0.5-1.3, waste fibres of cotton ginneries - 0.7-1.0, alumosilicate microspheres - 4.0-25.0, talc - 4.0-11.0.

EFFECT: invention makes it possible to increase the damping properties, adhesion to metal and frost resistance of the composition.

1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to polymer composition for manufacturing sealing and electroinsulating materials for production of connection cable envelope. Composition contains low-pressure polyethylene, lubricant buxol as plasticiser and filling agent representing titanium oxide.

EFFECT: composition is characterised by high thermodynamic compatibility of components, which makes it possible to obtain material with high mechanical characteristics and optimal combination of electro- and hydroinsulating properties.

2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to polyethylene composition, intended for obtaining slow-burning construction materials of general technical and engineering-technical purpose. Composition contains high-density polyethylene and filling agent with particle size 0.145-0.315 mm in quantity 30-50 wt. p. per 100 wt. p. of polyethylene. Filling agent represents mixture of crushed basalt and crushed basalt wool.

EFFECT: obtained compositions possess increased output of coke residue at 600°C, Vicat softening temperature, temperature of destruction starting, toughness, bending strength, as well as high weight loss during combustion.

1 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an antifrictional polymer composition based on ultra-high-molecular-weight polyethylene, particularly for making friction bearings in mobile friction assemblies of machines and mechanisms. The composition contains ultra-high-molecular-weight polyethylene and an inorganic modifier, wherein the inorganic modifier used is thermally expanded graphite in amount of 2 wt %.

EFFECT: composition has improved deformation-strength properties, wear resistance and bearing capacity.

1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a bimodal polyethylene high-density composition for obtaining products by pressure moulding, in particular caps and plugging means. The composition includes bimodal high-density polyethylene, a composition of an inorganic alpha-nucleating agent, a composition of a friction-reducing agent, representing amide of primary fatty acid, and a composition with one or more additives, selected from antioxidants, acid acceptors, pigments and UV-stabilisers. The application of bimodal polyethylene in a combination with the inorganic alpha-nucleating agent, in particular, with talc and behenamide, as the friction-reducing agent, makes it possible to obtain the moulding composition with an unexpected and synergic impact on crystallisation temperature, and the composition friction coefficient.

EFFECT: composition by the invention demonstrates higher crystallisation temperature and lower friction coefficient.

14 cl, 5 tbl

FIELD: chemistry.

SUBSTANCE: invention deals with ultrahigh molecular weight polyethylene (UHMWPE), modified with nanosized particles of tantalum pentoxide. It is applied for the obtaining polycomposite materials, which can be applied in microelectronics, medicine and other fields. It is obtained by the addition of benzyl alcohol to a UHMWPE benzene solution. The formed reaction mixture is mixed at a rate of 400-500 rev/min in boiling for 5-6 hours. Then, it is filtered, washed with benzene, the solvent is distilled. After that, a benzene solution of tantalum pentachloride is added to the reaction mass in a quantity corresponding to the molar ratio of tantalum pentachloride to benzene alcohol, equal to 1:5-5.3. Then the obtained reaction mass is mixed at the same rate in boiling for 3-4 hours, cooled and the target product is separated by filtering, extraction with chloroform and vacuum distillation of the solvent.

EFFECT: extension of application fields of materials with higher physical-mechanical properties.

3 dwg, 2 tbl, 2 ex

FIELD: technological processes.

SUBSTANCE: invention relates to the field of material science, in particular, to anti-friction polymer composite materials, and may be used in manufacturing of parts of metal-polymer friction units and in general machines of various types of equipment. The method to manufacture items from polymer composite materials on the basis of polytetrafluorethylene consists in the fact that fillers are mixed with polytetrafluorethylene in a mixer with rotation frequency of 2800 min-1, and cold pressing is carried out in a closed die mould. Then the pressed stock is installed into the closed device, and additional pressure of compression is developed in the pressing direction. Besides, the additional pressure of compression is regulated and set within 2.0 - 8.0 MPa.

EFFECT: increased characteristics of mechanical and tribotechnical properties of a composite material based on polytetrafluorethylene.

1 tbl, 1 dwg

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