摘要:
A partially crystalline copolyamide formed from an aromatic carboxylic acid that is terephthalic acid or a mixture of terephthalic acid and isophthalic acid containing less than 40% of isophthalic acid, and an aliphatic diamine that is a mixture of hexamethylene diamine and 2-methyl pentamethylene diamine. The aliphatic diamine is at least 40%, molar basis, of hexamethylene diamine and the amount of isophthalic acid plus 2-methyl pentamethylene diamine is in the range of 15-35%, molar basis, of the total amount of aromatic carboxylic acid and aliphatic diamine. The copolyamides have a melting point of 280.degree.-330.degree. C. The copolyamide preferably has a heat of fusion of greater than 17 J/g. The copolyamide may be moulded into articles, spun into fibres or formed into films, and used in a wide variety of end-uses especially where high temperature properties are required.
摘要:
A continuous process for the manufacture of a fibrous material from a polyolefin. The process comprises feeding a solution of polyolefin dissolved in an organic solvent at elevated temperature and pressure to a spinneret. The exit of the spinneret is the inlet to an elongated vertical tube and is located in an upper section of an elongated vertical vessel. The tube extends for a major portion of the length of the vessel. Solvent is removed from an upper section of the vessel and water is sprayed both down the tube and into the vessel. The strands thus formed are shredded in a self-cleaning self-feeding shredder located at the bottom of the vessel. The shredded fibres and water are conveyed to a second vessel having a baffle located between the inlet and outlet thereof such that the shredded fibrous material passes from the inlet, over the baffle and to the outlet of the second vessel, the upper lip of the baffle being so that the level of water in the second vessel is in substantially the same horizontal plane as the shredder. An inert gas e.g. steam, is fed to the second vessel to effect removal of volatile matter. The shredded fibres and liquid passing from the second vessel are fed to a dewatering device. The process may be used to manufacture fibrous polyolefin products e.g. the form of a pulp. The preferred polyolefin is a high molecular weight homopolymer of ethylene or copolymer of ethylene and at least one C.sub.4 -C.sub.10 hydrocarbon alpha-olefin.
摘要:
Explosives that are sensitized blends of inorganic nitrate, e.g., AN, particles, such as AN or ANFO prills, and an aqueous slurry comprising a thickened aqueous solution of an inorganic oxidizing salt, preferably AN, are rendered storage-stable by keeping the slurry's water content low enough, and its viscosity high enough, that the slurry is water-retentive. Water immobilization in the slurry, a requirement for storage stability, is achieved despite the slurry's flowable consistency at the time of blending. A blend containing about 25% slurry or less, is essentially in the form of a granular mass of free-flowing, high-density, slurry-bearing prills, and the slurry is sensitizable by the prills alone. As the slurry content exceeds about 25%, the blend takes on the characteristics of a thick slurry, requiring a supplemental sensitizer in the slurry per se. Slurries containing a nitrogen-base salt of an inorganic oxidizing acid, preferably monomethylamine nitrate, are preferred because this additive affords a saturated solution with lower water content, and also can act as a sensitizer.
摘要:
A coating composition of a fluorocarbon polymer which cures at ambient temperatures in which a fluorocarbon polymer in solution is of vinylidene fluoride and hexafluoropropylene and has a weight average molecular weight of about 5,000-600,000; the composition also containsdispersed fluorocarbon polymer particles of the following group polytetrafluoroethylene, fluorinated ethylene/propylene polymer, polyvinyl fluoride, polyvinylidene fluoride, copolymer of tetrafluoroethylene/perflouroalkoxyvinyl ether;a metallic oxide such as magnesium oxide which is an acid acceptor; andan aliphatic or cycloaliphatic polyamine curing agent;preferably, the composition contains a reinforcing pigment such as titanium dioxide.The coating composition is used to provide corrosion and abrasion resistant coatings for large structures in chemical plants, oil refineries, oil drilling platforms, and as a coating for the interior of smoke stacks of large utility companies.
摘要:
A method of partitioning a pre-selected phase of a sample of liquid having a plurality of phases of differing densities, a separation device and a tube containing the separation device. The sample of liquid is placed in a first chamber of a linear tube that is separated from a second chamber by a separation device. The separation device slidably engages the interior surface of the tube in an essentially fluid-tight manner and has an axial orifice on the longitudinal axis of the tube that is in fluid flow communication with a flow-restriction channel. The phases are ordered concentrically by rotating the tube around its longitudinal axis e.g. in an axial centrifuge. The volume of the first chamber is reduced by movement of the separation device within the tube, that phase of the liquid located axially within the first chamber flowing into the axial orifice and passing through the flow-restriction channel into the second chamber. The reduction of the volume of the first chamber is controlled using phase-separation information. The method is useful in separation of blood components.
摘要:
A process, apparatus and system for making a sterile connection between two thermoplastic resin tubes is disclosed. The tubes are severed by an array of hot wires so as to form molten tube ends. The array is maintained at a temperature such that ambient air immediately within the vicinity of urging is kept sterile. Then, the tubes are aligned with each other and urged together. As the thermoplastic resin cools a sterile weld is formed.
摘要:
The present invention relates to a heat-meltable fluoropolymer composite composition having excellent thermal conductivity, gas and chemical liquid barrier properties and dynamic properties such as storage modulus which comprises a heat-meltable fluoropolymer fine powder and a layered-compound organized by treatment with tetraphenyl phosphonium ions. The present invention also relates to a heat-meltable fluoropolymer composite composition having similar properties to those mentioned above which is obtained by a process (I) in which a heat-meltable fluoropolymer composite composition is obtained by grinding and mixing a heat-meltable fluoropolymer fine powder and a layered-compound and a process (II) in which such heat-meltable fluoropolymer composite composition thus obtained is melted and mixed under shear stress by means of a melt-mixing extruder.
摘要:
A mouldable reinforced polyamide composition comprising;(a) a polyamide consisting essentially of between about 0.5 and about 99.5 mol. % of aliphatic diamines having 4-12 carbon atoms and a complementary amount of 2-methyl-pentamethylene diamine copolymerized with aliphatic dicarboxylic acids having 6-12 carbon atoms; and(b) a filler in an amount of 0.5 to 200 parts by weight per 100 parts by weight of said polyamide. The polyamide has an RV greater than about 20. Related polyamides, especially in which the acid is 1,12-dodecanedioic acid, are also disclosed. The polyamides may be used in a wide variety of end-uses, including moulding, and exhibit excellent gloss compared with nylon 6,6.