Showing papers on "Thermoplastic published in 1990"

Catheter tubing of controlled in vivo softening

Abstract: A catheter tubing has a layer of a hydrophobic stiffening polymer encapsulated by a layer of hydrophilic thermoplastic base polymer. Preferred stiffening polymers are polyesterpolyether block copolymers. Preferred base polymers are thermoplastic polyetherurethanes. The encapsulated layer may be a stripe or an annular layer having base polymer layers laminated on both surfaces thereof.

Method for producing molded article of fiber-reinforced thermoplastic resin

Abstract: A method for producing a molded article of a fiber-reinforced thermoplastic resin, which comprises supplying a melt mass of a thermoplastic resin (A) which is reinforced with fibers dispersed therein and having an average fiber length of not shorter than 1 mm and not longer than 50 mm as a reinforcing material in an unclosed mold in which a film or sheet made of a thermoplastic resin (B) having adhesiveness to a thermoplastic resin (A) is optionally placed, closing the mold and pressurizing and cooling it to obtain a molded article.

Degradable multilayer thermoplastic articles

Abstract: The invention relates to multilayer degradable thermoplastic articles. In one embodiment the novel multilayer thermoplastic article comprises a first outer layer, a core layer and second outer layer, wherein the first outer layer and second outer layer are degradable by photo, thermal or chemical means and contain an effective amount of a prodegradant and the core layer is a water-soluble and/or biodegradable core layer, preferably both water-soluble and biodegradable. Bags formed from the multilayer thermoplastic article are useful for use in the composting of organic material.

Manufacture of Powder-Impregnated Thermoplastic Composites

Abstract: The use of thermoplastic composites has been limited by the lack of reliable techniques to make prepregs of consistent quality. Dry powder impregnation methods offer a new approach to the solution of this problem. This paper discusses the features that are essential to the development of an acceptable dry powder process The physical principles that govern the manufacture of thermoplastic prepreg tapes of controllable fiber-matrix volume fractions and the consolidation of these tapes to make void-free composite parts are presentedA novel powder prepregging process suitable for the manufacture of high-quality powder-impregnated tapes and their subsequent consolidation to make void-free parts is discussed. It is shown that a well-designed dry powder process can achieve fine control over both fiber-matrix composition in the prepreg tape and intimate wetting between in dividual fibers and the thermoplastic matrix Powder prepreg tapes can be consolidated into void-free specimens with simple consolidation cycles...

Iridescent film with thermoplastic elastomeric components

Abstract: Improvements in multilayer light reflecting film are effected by the use of a thermoplastic elastomer resin in a system in which two or more resinous materials form a plurality of the layers.

Advance composites with thermoplastic particles at the interface between layers

Abstract: The invention relates to prepregs of fiber-reinforced thermosetting resin that have a coating comprising thermoplastic particles on one or both outer surfaces. Upon lamination of the prepregs into a composite, the layer comprising thermoplastic particles at the surface of the prepreg is formed into a discrete resin layer in the composite at the interface between fiber-reinforced thermosetting resin layers. The laminated composite materials have improved toughness and impact strength due to the thermoplastic particulate material at the interface and yet the composites still retain desired mechanical properties under hot/wet conditions.

Extruder apparatus and process for compounding thermoplastic resin and fibres

Abstract: Multiple extruder apparatus for compounding thermoplastic resin and reinforcing fibers incorporates a resin extruder in which thermoplastic resin pellets are melted and a compounding extruder in which the molten thermoplastic resin is mixed in intimate contact with long reinforcing fibers of at least one inch in length. The melted thermoplastic resin is introduced into the compounding extruder at a point downstream of the inlet point for the reinforcing fibers, so that the fibers are mechanically worked and heated before coming into contact with heated, molten thermoplastic resin. The extrudate from the compounding extruder consists of a homogeneous, molten mass of thermoplastic resin having discrete lengths of fibers randomly dispersed therein.

Solid feeding of silane crosslinking agents into extruder

Abstract: A process for producing a polymer crosslinkable by exposure to moisture in the presence of a hydrolysis/condensation catalyst comprising blending (i) a thermoplastic base polymer, (ii) a solid carrier polymer containing a silane, and (iii) a free radical generator; heating and mixing (i), (ii) and (iii) together at a temperature above the crystalline melting point of said base polymer; optionally, a free-radical generator, hydrolysis/condensation catalyst, and other additives are contained in the solid carrier polymer.

Impact resistant blends of thermoplastic polyamides, polyolefins and elastomers

Abstract: The present invention relates to an impact resistant polymeric composition, useful as a structural material, comprising a polyamide such as a nylon 6,6, a polyolefin such as polypropylene, and a functionalized elastomer such as a maleated-EPDM.

Optical recording medium

Abstract: PURPOSE:To maintain surface smoothness of a film and to obtain excellent wearing resistance and lubricating property by laminating a signal recording layer, metal film layer, biaxially oriented polyester film and specific coating layer in the order. CONSTITUTION:A thermoplastic resin substrate is softened with solvents or heat and modified to form the signal recording layer, on which an Al vapor deposition film of 5-10 nm thickness is provided. Then the polyester film is provided which contains aromatic dicarboxylic acid such as terephthalic acid or aliphatic carboxylic acid such as adipic acid as the acid content and ethyleneglycol, etc., as the alcohol content. The energy of fusion of the polyester resin is selected to be 3-11cal/g to improve the moldability and adhesion of the film. The surface coarseness of the metal film side is specified to be =70wt% of nonactive inorganic powder, such as TiO2 with average particle size of 0.11-0.70mum and water-soluble or water-dispersible resin. The proportion of the average particle size D of the inorganic powder to the thickness d of the coating layer is selected to 1.1-80. By this constitution, such an optical recording medium cheap and having good qualities can be obtained.

Glossy finish fiber reinforced molded product and processes of construction

Abstract: Fiber reinforced thermoplastic molded products, sheets, and the like, having a glossy surface are produced by intimately blending discrete reinforcing fibers (e.g. fiberglass) and thermoplastic fibers (e.g. polypropylene or polycarbonate) into a web. The web is heated to the melting point of the thermoplastic fibers while applying pressure, to eliminate air and press the web into a consolidated structure. Breakage of the reinforcing fibers is minimized by limiting the thickness of the web and limiting the pressure so as to produce a consolidated structure with minimal fiber breakage and a Notched Izod of at least one. Layered consolidated structures, some without reinforcing fibers, may be heated and pressed together to form a final structure having a thickness greater than the individual structures. The great majority of the fibers are provided so that the fibers of each type are within the range of about 0.5-5 inches. A sheet capable of replacing an automotive metal panel (that is having sufficiently high gloss, rigidity and impact characteristics) is provided, the sheet having a Notched Izod of at least about two and preferably at least about five. Products with Notched Izods of up to eight or nine may be achieved.

A method of forming composite structures using in situ-formed liquid crystal polymer fibers in a thermoplastic matrix

Abstract: A new high speed and potentially economical method of creating a composite material and structures therefrom is tested. The method consists of spinning composite fibers from a melt blend of a thermoplastic with a liquid crystal polymer (LCP). Discontinuous fibrils of the LCP are formed in situ during the spinning process. These composite fibers are aligned and placed in a mold and heated to melt the thermoplastic matrix, but not the fibrils. A finished composite structure reinforced by the LCP fibrils is obtained when the thermoplastic phase is consequently consolidated. Our experiments show the proposed process is reasonable for an easily processed polystyrene matrix. High modulus fibrils with essentially infinite L/D ratios are readily produced in the extrusion process using 40 wt% of a wholly aromatic poly(ester-co-amide) LCP from Celanese. The integrity and alignment of the LCP fibrils is retained in the molding step. Mechanical tests show that the fibers produced by high shear rate processing have a stiffness approaching 23 GPa and match an axial rule-of-mixtures theory. The use of polystyrene resulted in brittleness. Molded composite plates exhibit slightly lower stiffness and significantly lower strength than individual fibers.

Three-dimensional polymer webs with improved physical properties

Abstract: There is disclosed a three dimensional nonwoven web consisting of drawn and unoriented thermoplastic fibers formed from a blend of polypropylene and polybutylene, wherein the blend by weight is from 90% to 70% polypropylene and from 10% to 30% polybutylene. The blend can be a blend of a homopolymer of polypropylene and a homopolymer of polybutylene; a homopolymer of polypropylene and a copolymer of polybutylene; a copolymer of polypropylene and a homopolymer of polybutylene; and a copolymer of polypropylene and a copolymer of polybutylene. In addition, ternary blends comprising polypropylene, polybutylene, and terpolymer (propylene, ethylene, and 1-butene) are useful. The resulting nonwoven webs have enhanced strength, toughness, and tear resistance.

Preparation and characterization of heterophase blends of polycaprolactam and hydrogenated polydienes

Abstract: The preparation, analysis, testing, and structure determination of ultrahigh impact rubber-toughened polycaprolactams (nylon 6) are described. Partially unsaturated hydrocarbon rubbers were used for this purpose. They were functionalized by reaction either in solution or in bulk with maleic anhydride to give rubbery “ene” adducts containing varying amounts of pendnet succinic anhydride. Tough, rigid, thermoplastic engineering resins with notched Izod impact strengths of 750–1000 J/m were prepared by briefly melt-blending these adducts with nylon 6. Properties of the blends could be affected by the type and amount of elastomer used, the anhydride content, the type of nylon, the mixing conditions and the test conditions. Fractionation by coacervation in m-cresol/cyclohexane of a typical resin containing 20% by weight of functionalized rubber showed approximately 35% of a rubber–nylon graft, along with a few percent of free rubber dispersed in the nylon 6 matrix. A comb-block copolymer structure for the graft and a model for its formation are proposed, consistent with analyses of the fractions. Some of the blends prepared with partially hydrogenated medium vinyl polybutadiene–maleic anhydride adducts displayed a retention of impact properties at low temperatures which was superior to that obtainable with a similarly prepared EPDM-modified nylon 6. Transmission electron microscopy of a blend containing an anhydride-modified hydrogenated medium vinyl polybutadiene showed a morphology consisting of a nylon matrix containing finely dispersed, irregularly shaped, 0.03–0.55 μm rubber domains in which were found even smaller domains of nylon.

Plastic based laminates comprising outer fiber-reinforced thermoset sheets, lofted fiber-reinforced thermoplastic sheets and a foam core layer

Abstract: A light weight, high strength laminate having improved fire resistant characteristics and the method of making the same. A preferred embodiment includes a low density fiber reinforced thermoplastic resin core between two parallel sheets of high density fiber reinforced thermoset resin. Another embodiment includes a core of polymeric foam laminated between two parallel inner fiber reinforced thermoplastic resin layers each of which face an outer layer of fiber reinforced thermoplastic resin.

Hydroxy-functional poly(amide ethers) as thermoplastic barrier resins

Abstract: Poly(hydroxy amide ethers) which exhibit high barrier properties are prepared by contacting one or more amide-containing bisphenols and an epihalohydrin. These polymers are suitable for use in the manufacture of articles such as rigid containers and flexible films exhibiting high barrier to oxygen transmission in moist environments.

Water-resistant polyvinyl alcohol film and its application to the preparation of gas-impermeable composite articles

Abstract: Polyvinyl alcohol films are provided which are gelled, non-tacky, bubble-free and resistant to water at ambient temperatures. The polyvinyl alcohol film is obtained by plasticizing (fluxing) and melting granules of pure polyvinyl alcohol containing from 25 to 35% by weight of water at a temperature at least 100° C. above the equilibrium melting point of the granules and less than or equal to 220° C., and extruding the melted granules through a die at a temperature at least 5° C. above the equilibrium melting point of the granules and less than or equal to 98° C., optionally followed by monoaxial stretching or biaxial stretching of the unstretched film obtained. The stretched or unstretched film may be heat-treated to improve its properties. The polyvinyl alcohol film can be used to prepare with thermoplastic films composite films or sheets having a high gas impermeability. The invention also provides composite, biaxially oriented, impermeable barrier layer coated, thermoplastic hollow shaped articles useful as packaging materials, e.g., as packages and bottles for flavored foods and carbonated beverages. The hollow shaped articles are produced by externally barrier covering a thermoplastic tubular blank, parison or preform with a relatively thick barrier layer consisting essentially of water-resistant and highly crystalline polyvinyl alcohol, said barrier layer having been prepared by shaping a melt of homogeneously shear fluxed and molten flakes or pure polyvinyl alcohol having a water content of 25 to 35% by weight thereof, with said shear fluxing and melting of said polyvinyl alcohol flakes being at a temperature above the equilibrium melting point of the polyvinyl alcohol/water admixture essentially constituting said flakes, and said shaping being at a temperature of at least said equilibrium melting point but less than that at which the vapor pressure of the component water would effect the surface expansion and bubbling of the desired barrier layer, and thence biaxially orienting and blow molding into final configuration said barrier covered blank, parison or preform.

Ballistic resistant composite article having improved matrix system

Abstract: An impact resistant rigid composite article comprising a fibrous layer comprising a network of filaments dispersed in a rigid matrix comprising one or more thermosetting resins and one or more thermoplastic resins.

Coextruded multilayer foamed film for plastic container closures and process for manufacture

Abstract: A plastic container closure, such as a bottle cap liner or tamper evident seal, is formed from a coextruded multilayer foamed film. The coextruded multilayer foamed film has at least one solid film layer of a first polyolefin blend containing linear low density polyethylene, low density polyethylene, and, optionally high density polyethylene, and at least one foamed layer of a second polyolefin blend containing linear low density polyethylene, low density polyethylene, and optionally ethylene vinyl acetate. The multilayer foamed film may be coextruded using a blown film or cast film extrusion process under defined conditions. The coextruded multilayer foamed film may be laminated to other materials such as polyester film, thermoplastic adhesive films or metallic films and used as a plastic container closure, or may be applied as a liner to a plastic bottle cap.

Thermoplastic resin composition

Abstract: A thermoplastic resin composition which comprises a polyethylene glycol compound such as polyethylene glycol and a water soluble thermoplastic polymer compound compatible with said polyethylene glycol compound such as a polymer comprising in a side chain a tertiary nitrogen atom such as of a lactam structure such as pyrrolidone and caprolactam, a tertiary amino group and a quaternary ammonium group. This resin composition softens at a relatively low temperature and is soluble in water, and besides adheres to various materials. Thus it is particularly useful as an adhesive which can temporarily bond an article to be processed to a jig at a low temperature and can be washed off with water to remove it from the article after the processing.

High shrink energy/high modulus thermoplastic multi-layer packaging film and bags made therefrom

Abstract: Disclosed is an oriented, heat-shrinkable, packaging film having a layer of polyamide or polyester. The film has a high shrink energy and high modulus.

Low density foamed thermoplastic elastomers

Abstract: A foamed thermoplastic elastomer having a substantially uniform closed cell structure and having a specific gravity of less than about 0l.40, an energy return ratio greater than about 0.50 when compressed and released said foam being prepared from a thermoplastic multi-block copolymer elastomer having a Shore D hardness of 25-75.

Polystyrene foam sheet manufacture

Abstract: The method of making polystyrene foam for foam products which comprises utilizing atmospheric gases as the blowing agents or preferably mixing one or more of these gases and a blending agent which is non-volatile at the extrusion temperatures, introducing the mixture to a molten thermoplastic polystyrene resin containing nucleating agents such as sodium bicarbonate and citric acid and extruding the thermoplastic in the form of a foam. The resultant foam has substantially no residual blowing agent, is dimensionally stable at ambient temperatures and when used with a non-volatile blending agent can be made with small amounts of blowing agent permitting cooling of the melt without high loading on the extruder. The foam may be coextruded with one or more layers of thermoplastic film so that the resultant product is adapted for use for plates, cups, food containers or packaging and for labels for containers such as glass and plastic containers and for labels that are shrunk in place on a container.

Composite material for dielectric lens antennas

Abstract: This invention is to provide a composite material for dielectric lens antennas which contains 3-70 percent by volume of a high dielectric constant ceramic and 30-97 percent by volume of a macromolecular material. At this time it is desirable that the mean particle diameter of the high dielectric constant ceramic is 1-50 μm. It is also preferable that the macromolecular material is a thermoplastic macromolecular material. A dielectric lens is made of this composite material for the dielectric lens antennas. Further, the dielectric lens antenna is preferably produced forming a matching layer on the dielectric lens surface.

Method of fabricating composite structures

Abstract: A method of fabricating a composite structure having at least one skin molecularly bonded to a core. A skin is provided of reinforcing fibrous material and a thermoplastic matrix. The skin is thermoformed to the general exterior shape of the composite structure. A core having a thermoplastic matrix complementary to the matrix of the skin is molded into the general shape of the composite structure. The skin and the core are placed in juxtaposition in a final forming mold. A thermoplastic material is injected into the final forming mold under isostatic conditions. The thermoplastic material is complementary to the thermoplastic matrices of the skin and the core.

Reversible polymer gel binders for powder forming

Abstract: Thermoplastic binder compositions comprising a high molecular weight polymer component and a molten wax component are compounded with sinterable ceramic or other inorganic powders. Upon cooling, a thermally reversible gel is formed in the binder by the gelation of the polymer in the molten wax. Ceramic batches comprising these binders behave as shear-thinning and thermally reversible gels. They exhibit substantially improved dewaxing performance and, preferably, extensibility sufficient for sheet reforming processes.

Transparent overlay for protecting a document from tampering

Abstract: A transparent overlay that can protect a document from tampering has a transparent cover sheet, a layer of hot-melt adhesive over one surface of the transparent cover sheet, and a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer. The transparent cover sheet can be a simple thermoplastic film but preferably is retroreflective sheeting which can bear a pattern or legend that is noticeable only when viewed retroreflectively. When the polymeric image-receiving layer is dye-receptive, it can be imaged by using a thermal printing head with a dye-donor element. A preferred polymeric image-receiving layer that is dye-receptive is chlorinated poly(vinylchloride).

Hot melt adhesives useful in temporary bonding operations

Abstract: Hot melt adhesives having suitable open time and crystallinity properties making them especially useful as temporary adhesives are provided by a composition comprising a combination of 5 to 50% by weight of an isotactic thermoplastic polybutylene copolymer or a low density ethylene polymer with 3 to 65% by weight of a solid benzoate plasticizer.

Method for producing resin rich surface layer on composite thermoplastic material

Abstract: A layer of a neat resin in powder form is deposited either on a mold surface or on a bulk thermoplastic composite fiber reinforced sheet. The resin layer is adjacent to an insulated wall of a compression mold. The bulk sheet is preheated and compression deformed with the powdered resin. The heat from the sheet flows to and melts the powder layer producing a resin rich layer. The insulated wall permits the heat of the sheet to be retained sufficiently to melt the powdered resin. In the alternative, the neat resin powder may be replaced with a preformed film of thermoplastic resin compatible with the sheet resin. A structural homogeneous integral molecular bond is formed between the neat resin layer and the sheet.

Flame-retardant resin composition

Abstract: The present invention relates to a flame-retardant resin composition having halogen content of 2 to 40% by weight basing on the amount of said composition, which comprises (a) 100 parts by weight of a styrene-based polymer having mainly syndiotactic configuration, or a mixture of 99 to 50% by weight of said styrene-based polymer and 1 to 50% by weight of a thermoplastic resin (exclusive of tetrafluoroethylene-based polymer) and/or rubber; (b) 3 to 40 parts by weight of a flame retardant selected from the group consisting of halogenated polystyrenes and halogenated polyphenylene oxides and (c) 1 to 15 parts by weight of an auxiliary flame retardant, as main components. In addition, the present invention contains the above components (a), (b) and (c) as main components, and further contains (d) 0.003 to 10 parts by weight of tetrafluoroethylene-based polymer and/or (e) 1 to 300 parts by weight of an inorganic filler. The present invention provides a resin composition which is excellent in flame retardance and further in heat resistance.