90results about How to "Improved environmental stress cracking resistance" patented technology

A polymer comprising sulfone groups, ketone groups and optionally substituted polyarylene groups, wherein the number of moles of sulfone groups over the number of moles of ketone groups ratio is greater than 1. A process for making such polymer, a composition comprising such polymer, and articles made therefrom.

The invention relates the silicon alky cross-linking low-middle-high density vinyon. The components comprises 0.8-3.0wt% silicon alky cross linking agent, 0.02-2.0wt% cross linking initiating agent, 0.02-1.0wt% cross linking catalyst, 0.01-3.0wt% anti-oxidant and 0.05-3.0wt% modified auxiliary agent. The method comprises the following steps: preparing silicon alky grafting material A, mixing A and B materials, handing with extrusion machine to get tubing product, keeping it in water bath at 85Deg.C or vaporium for 8 hours, and getting the product. The invention overcomes the defects of big contraction percentage and degelatinizing phenomena between polythene layer and metal layer; the invention has the advantages of short production circle, stable technology and high rate of finished products.

The invention discloses a metallocene polypropylene modified material for a corrosion-inhibiting coating of a steel pipe and a preparation method and application thereof. A formula of the material comprises 65 to 95 weight percent of metallocene polypropylene, 3 to 30 weight percent of co-polypropylene, 0.01 to 4 weight percent of thermal oxygen stabilizer, 0.03 to 3 weight percent of ultraviolet absorbent and light stabilizer, 0.02 to 5 weight percent of functional additive, 0.01 to 3 weight percent of inorganic nanometer reinforced material, and 0 to 5 weight percent of black color batch, and the material is prepared by adopting a double screw extruder to carry out plasticizing blending technology for extrusion and pelletization. The metallocene polypropylene modified material has wide casting and coating processing range, has strong adaptability to bottom glue of hot melt adhesives, has outstanding ultraviolet light aging resistance and thermal-oxidative aging resistance, and has excellent shock resistance and surface scratch resistance as well as extremely high environmental stress cracking resistance. The material can be suitable for terrestrial pipelines at continuous working temperature high up to 110 DEG C, and is also suitable for offshore pipelines atcertain special continuous working temperature high up to 140 DEG C at the same time.

The invention discloses a solar-powered back plate. The solar-powered back plate comprises an inner surface layer, a core layer and an outer surface layer in the mass ratio of (10-20):(20-40):(40-60) from inside to outside, wherein the inner surface layer is made from vinyl resin, a filler and an additive; the outer surface layer is made from polyamide resin, a filler and an additive; and the core layer is made from a modified polyethylene resin composition. The invention further develops a novel polyethylene resin composition, which comprises 100 parts of crosslinked polyethylene resin, 0-50 parts of grafted polyethylene, 0.1-0.5 parts of catalyst, 0-100 parts of filler and 0-2.5 parts of additive. The novel solar-powered back plate developed by the invention is prepared through a coextrusion process; and a prepared final product has the advantages of superior adhesion, high interlaminar peeling strength, aging resistance, particular damp-heat aging resistance, low saturated water absorptivity, low water vapor transmittance and superior electric insulating property, simple preparation process, low cost and suitability for industrial production.

A polyethylene composition comprising at least a first composition and a second composition in amounts of at least 70 wt% of the first composition which comprises at least: (A) up to 60 wt% lower molecular weight (LMW) polyethylene homo or copolymer obtained by Ziegler-Natta catalysis having a density of at least 940 kg / m<3>; and (B) up to 60 wt% higher molecular weight (HMW) polyethylene homo or copolymer obtained by Ziegler-Natta catalysis and having lower density than component (A); and up to 30 wt% of the second composition which comprises: (C) a polyethylene homo or copolymer obtained by single site catalysis (SSC) and having a density of up to 980 kg / m<3>; wherein said polyethylene composition has a charpy impact strength at -20 DEG C, according to ISO 179-3 on compression moulded plates of at least 2.5 kJ / m<2> and density at least 925 kg / m<3>.

The invention discloses an ABS / polyester alloy material as well as a preparation method and application thereof. The ABS / polyester alloy material comprises the following components by parts: 50-80 parts of styrene-butadiene-acrylonitrile resin, 10-65 parts of polyester resin, and 1.0-15 parts of a high-damping elastomer. According to the method disclosed by the invention, a polyester and high-damping rubber are introduced into an ABS system, so that the prepared ABS / polyester alloy material has excellent environmental stress cracking resistance while having a noise reduction effect, can replace ABS, HIPS or PC / ABS to be used for various plastic parts, can effectively reduce noise made by the parts, can greatly improve environmental stress cracking resistance of the parts, solve the problems of water leakage and cracking caused by the problem, and has significant technical and market value.

The invention provides an EVA (ethylene-vinyl acetate) precoating packaging adhesive film and a preparation method thereof. The adhesive film is composed of three layers, wherein the middle layer is a BOPP (biaxially-oriented polypropylene) film layer, and the upper and lower layers are respectively an EVA adhesive layer. The EVA adhesive layer is prepared from 100 parts of ethylene-vinyl acetate copolymer, 0.5-1 part of crosslinking agent, 0.1-2 parts of antioxidant, 0.01-0.02 part of light stabilizer and 0.02-0.04 part of tackifier. A precoating technique is adopted to produce the EVA packaging adhesive film, i.e. the EVA adhesive layers are coated to the upper and lower surfaces of the BOPP film layer to constitute the EVA packaging adhesive film, thereby greatly enhancing the production rate and simplifying the technique complexity degree under the support of the BOPP film. The bonding firmness between the EVA adhesive layer and BOPP film layer is enhanced, and the shock strength and environmental stress crack resistance of the adhesive film are enhanced.

The invention discloses a flame-retardant and high-temperature-resistant computer cable. The cable comprises core wires, first wrapping layers, a second wrapping layer, a shielding layer, an armor layer and a sheath layer. Each core wire comprises tinned copper core conductors and insulating layers; the outer side of each tinned copper core conductor is wrapped with the corresponding insulating layer; every two core wires are twisted to form a pair wire set; and the outer side of each pair wire set is wrapped with the corresponding first wrapping layer. According to the invention, the quartz fiber maintenance sleeve layer on the outer side of the cable has the advantages of flame retardance, high-temperature resistance, insulationresistance, ablation resistance, corrosion resistance, heatinsulation ability, wave transmission ability, excellent dielectric property and the like; the cable can be protected from combustion in case of a fire; compared with polyethylene insulation, the performance of the the cross-linked polyethylene insulation is greatly improved after cross-linking modification; the comprehensive performance such as the mechanical performance, the environmental stresscracking resistance, the chemical corrosion resistance, the creep resistance and the electrical performance is remarkably improved; and the temperature resistance level is remarkably improved.

The invention discloses a manufacturing method of a carbon fiber reinforced HDPE double-wall winding pipe; firstly, a high-density polyethylene mixture is prepared by high-density polyethylene, a peroxide initiator, polyfunctional group monomers, a high molecular compatilizer and antioxidant; and modified carbon fibers are prepared by carbon fibers and a silane coupling agent. Then, the high-density polyethylene mixture and the modified carbon fibers are reacted and coextruded through a double-screw extruder, and are extruded by a mold and shaped in vacuum to obtain a carbon fiber reinforced HDPE hollow square pipe; and then, the carbon fiber reinforced HDPE hollow square pipe is spirally wound and welded by plastic hot melt adhesive to manufacture the carbon fiber reinforced HDPE double-wall winding pipe. As carbon fiber reinforced HDPE is adopted to manufacture the hollow square pipe, the creep resistance, the modulus, the impact resistance, the scratch resistance, the slow-speed crack expansibility resistance, the environmental stress cracking resistance and the high-temperature resistance are all greatly improved; and the double-wall winding pipe totally has enough gap tensile strength, so that the whole performance of the pipe is effectively improved.

The invention relates to high-density polyethylene resin for preparing a small hollow product with extrusion blow molding. A process of connecting two kettles of a Mitsui slurry polymerization device in series is adopted; then a reaction kettle is connected in series; only ethylene is added into the first reaction kettle; ethylene and butene-1 are added into a second reaction kettle and a third reaction kettle; the molecular weight distribution of HDPE (High-Density Polyethylene) is widened further through the polymerization of the third reaction kettle; meanwhile, the content of the butene-1 as a copolymer monomer of a high-molecular weight part is increased in order to meet the requirement on the HDPE for preparing the small hollow product with the extrusion blow molding. The HDPE has superior mechanical performance, can be up to 28MPa in tensile yield strength to the maximum extent, is over 200h in environmental stress cracking resistance, is improved remarkably in toughness, and can be widely applied to molding and processing of the small hollow product.

a non-crosslinked refractory polyethene pipe reinforced by metal skeleton is composed of a main body made of non-crosslinked refractory polyethene and a cylindrical reinforcing metallic skeleton skeleton embedded in the main body and made of curled reticular steel sheet or wound and welded steel wires. Its advantages are high resistance to low temp., high temp. and environment stress, good thermofusibility and long service life.

The invention relates to an air-drop type storage-transportation packaging box convenient to stack and a preparation method of the packaging box, belonging to the package and transportation fields. The packaging box comprises a box body and a box cover which are mutually buckled, wherein the box body and the box cover are prepared from the following raw materials in parts by weight through rotational molding: 50-70 parts of linear low density polyethylene, 50-70 parts of low density polyethylene, 40-80 parts of high density polyethylene, 10-30 parts of medium density metallocene polyethylene and 1-6 parts of a coupling agent; and rig grids are arrayed at the bottom of the box body or the top of the box body or the box cover in a matrix manner, the rig grids at the top of the box body or the box cover are mutually seamed and clamped with the rig grids at the bottom of the box body on an upper layer so as to form embedding and splicing type anti-dislocation stacking structure. The packaging box is produced from the polyethylene materials with different densities through mixing and rotational molding, and modularized rid grid structures are arranged at the top and the bottom of the packaging box, so that the strength, impact resistance and packaging efficiency of the packaging box are improved, and the mutual stable stacking of different specifications of packaging boxes is realized.

A stretch orientated silane cross-linked polyethene pipe features that its pipe wall contains at least one polyethene layer, which is orientated by radially or both radially and axially stretching and then hydrolytically condensated for cross-linking with silane. Its advantages include high pressure-bearing power and high anticracking performance. Its preparing process is also disclosed.