Showing papers on "Polycarbonate published in 1975"

Process for preparing a branched polycarbonate

Abstract: A process for preparing a thermoplastic randomly branched aromatic polycarbonate which process comprises reacting at least 20 weight percent of a stoichiometric quantity of a carbonate precursor with a mixture of a dihydric phenol and at least 0.05 mole percent of a polyfunctional aromatic compound in a medium of water and a solvent for the polycarbonate having present therein at least 1.2 mole percent of a polymerization catalyst, while concomitantly adding to the reaction medium sufficient alkali metal hydroxide to maintain a pH range of about 3.0 to about 6.0, and then adding sufficient alkali metal hydroxide to raise the pH to at least about 9.0 to less than about 12 while reacting the remaining carbonate precursor.

Tough thermoplastic polyester compositions

Abstract: Toughened multi-phase thermoplastic composition consisting essentially of one phase containing 60 to 99 percent by weight of a polyester including polycarbonate matrix resin of inherent viscosity of at least 0.35 deciliter/gram, and 1 to 40 percent by weight of at least one other phase containing particles of at least one random copolymer having a particle size in the range of 0.01 to 3.0 microns and being adhered to the polyester, the at least one random copolymer having a tensile modulus in the range of 1.0 to 20,000 p.s.i., the ratio of the tensile modulus of the polyester matrix resin to tensile modulus of said at least one polymer being greater than 10 to 1. Said at least one polymer is either a branched or straight chain polymer. The toughened compositions are useful for making molded and extruded parts. Such parts possess greater ductility, less reduction in toughness from scratches and molded in notches and reduced susceptibility to catastrophic failure when compared to known melt fabricated materials.

Flame-resistant polycarbonates

Abstract: The present invention relates to flame resistant aromatic polycarbonate molding compositions which are blends containing between about 0.1 to 15 wt.% of sulphur. The blends of the present invention may also contain up to about 30 wt.% of glass fibers. The present invention also relates to improving the flame resistance of polycarbonate molding compositions by physically incorporating 0.1 to 15 wt.% of sulphur therein.

Method of bonding a phenol-based thermoplastic resin to a cured and molded thermoset phenolic plastic

Abstract: A method of making grinding wheel mounts by molding a central hub onto a thermoset plastic abrasive disc is provided. An aromatic polycarbonate thermoplastic resin is molded to form a hub on a cured thermoset plastic abrasive disc. It is believed that the polycarbonate forms both a mechanical and chemical bond with the thermoset plastic to provide an efficient method of producing grinding wheels.

Moulding compositions contain polycarbonate and graft copolymer of a resin forming monomer on a rubber

Abstract: The invention relates to moulding compositions containing polycarbonate and graft copolymers of resin-forming monomers on a rubber.

Transparent formable polyurethane polycarbonate lamination

Abstract: A method for producing clear, cured transparent polycarbonate laminates comprises directly bonding a sheet of transparent thermosetting polyurethane sheet to a polycarbonate sheet to produce a laminate, heating the laminate above the softening point of the polycarbonate sheet, and forming the laminate to a desired curvature.

Novel flame retardant polycarbonate compositions

Abstract: This invention is concerned with a new class of flame retardant polycarbonate compositions. More particularly, the invention is concerned with admixtures of an aromatic polycarbonate and a flame retardant additive combination consisting of a halogenated organic compound and an alkali or alkaline earth metal salt of an inorganic sulfur compound. The flame retardant polycarbonates can be molded or formed into flame retardant articles such as films, sheets, fibers, laminates or reinforced plastics by conventional techniques.

Thermal activation parameters for large strain deformation of polyethylene and polycarbonate

Abstract: Experiments were performed to determine the effects of strain rate, temperature, and pressure on the flow stress of polyethylene and Lexan polycarbonate deformed in shear. The results were analyzed to determine the activation enthalpy and the shear and dilatation activation volumes of the rate-limiting mechanism of the deformation process. Results show that the activation event involves a volume containing several monomer units and that this volume must dilate by as much as 7% during the activation event. The activation enthalpy was approximately 2.5 × 10−12 erg for polyethylene and 1.1 × 10−12 erg for polycarbonate. The rate-limiting mechanism for polyethylene seemed to be unchanged by plastic strains of up to 250%.

Studies of the amorphous region of polymers. II. Relationship between change of structure and glass‐transition temperature in polycarbonate

Abstract: A study of the effect of drawing on the glass transition temperature Tg of amorphous polycarbonate was carried out. The Tg attains a maximum at a draw ratio in the range from 1.6 to 2.0. The relationship between the change of structure and Tg is discussed in terms of the configurational entropy and the rate of molecular motion in local mode relaxation. The variation of Tg with drawing may be explained by using the iso-entropy theory. The frequency of the maximum in the dielectric loss fmax and the dielectric relaxation strength Δe of the β mechanism changed with drawing in the same way as that of Tg. Based on the parallel behavior in these results, it is reasonable to consider that the β process of local mode relaxation of polyesters such as PC and PET reflects the structure of the glassy state.

Aliphatic polycarbonates contg. hydroxyl end gps. - prepd. by alcoholysis of dihydric alcohols with glycol carbonate without catalyst

Abstract: Parent Patent describes prepn. of aliphatic polycarbonates contg. aliphatically bonded OH gps., by alcoholysis of dihydric alcohols with glycol carbonate. In the presently disclosed method alcoholysis takes place in absence of catalysts. Terminal OH gp.-contg. aliphatic polycarbonate obtd. is free from cpds. which might impair its subsequent reaction with polyisocyanates. An example is prepn. of colourless, waxy polycarbonate having OH-no. 65-67, by reacting 2 mol. hexanediol-1,6 and 2.2 mol. glycol carbonate in cumene, at 155 degrees C.

Effects of drawing on molecular motions in polycarbonate

Abstract: The effect of drawing on the molecular motions in amorphous polycarbonate is studied by the dielectric relaxation with following conclusions. (1) A structural model for the drawn polycarbonate is obtained from the data of the density, the birefringence and the height of the endothermic peak atTg. The molecular chains of polycarbonate are supposed to be oriented to the draw direction and packed closely by drawing. No process similar to that in polyethylene terephthalate occurs in polycarbonate. (2) The rate of the torsional oscillation of the frozen chains in the glassy polycarbonate varies with the draw ratio. It decreases at first and then increases near the severance. This behavior can be explained by the local mode relaxation theory and the structural model proposed here. (3) The behavior of polycarbonate by drawing was compared with that of polyethylene terephtalate and discussed.

Process for the preparation of high molecular thermoplastic polycarbonates of low flammability

Abstract: The present invention is concerned with a process for the production of high molecular weight thermoplastic ppolycarbonates having improved flame resistance and in conjunction with glass fibres, improved mechanical properties and the polycarbonates so produced. A solution polycarbonate is reacted with an alkali metal salt soluble in the melt of the polycarbonate until the Staudinger Index has increased by about 3 to 30 cm3 /g. This usually requires about 0.0001 to 0.1 wt. % of the salt, based on the weight of polycarbonate and a temperature of about 250° to 400° C for between about 1 and 30 minutes. In a preferred embodiment the reaction is conducted in a self-cleaning twin screw extruder.

Flame-resistant polycarbonate molding compositions

Abstract: Molding compositions having an oxygen index of greater than 0.30 based on high molecular weight aromatic polycarbonates containing 0.5-20% of organic fibers.

Polycarbonate resin compositions

Abstract: PURPOSE: Glass-filled polycarbonate resin compn free from discoloration during molding, etc contains a phosphite and phenolic anti-oxidant COPYRIGHT: (C)1976,JPO&Japio

High molecular weight polycarbonates of α,α,α,α',α',α'-hexakisaryl-1,3-and/or -1,4-dimethyl benzenes

Abstract: The present invention is related to high molecular weight polycarbonates based on aromatic dihydroxy compounds which contain 5 to 100 mol % preferably 20 to 100 mol % of structural units derived from α,α,α,α',α',α'-hexakisaryl-1,3-and/or -1,4-dimethyl benzene dihydroxy compounds. In a preferred embodiment, the polycarbonate is a copolymer of the hexakisaryl dihydroxy compounds and bisphenols known to be useful in producing polycarbonates. The residues of the hexakisaryl compound may be 5 to 90 mol %, preferably 20 to 70 mol % of the structural units. An especially preferred copolymer is that between the hexakisaryl compounds and α,α'-(hydroxyphenyl)-diisopropyl benzenes. These polycarbonates show improved heat stability and higher second order transition temperature points than conventional polycarbonates and are useful in applications involving high service temperatures such as electrical insulating film.

Effects of Adhesive Structure on Impact Resistance and Optical Properties of Acrylic/Polycarbonate Laminates

Abstract: Acrylic/polyurethane/polycarbonate laminates have demonstrated resistance to impact by high velocity projectiles up to 100 percent greater than monolithic polycarbonate, currently considered the best commercially available transparent impact-resistant material. The energy absorbed during impact was found to be dependent on the chemical composition and microstructure of the adhesive interlayer and varied by a factor of two over the range of variables investigated. Polyurethanes based on MDI-butanediol “hard” and block copolyether “soft” segments, used as the laminate interlayer, affect both impact resistance and optical clarity as chemical composition of the urethane is varied. Microstructure as seen in both the optical and transmission electron microscope changes from no visible structure in transparent materials, through few widely scattered isolated spherulitic structures in translucent materials, to densely packed interpenetrating spherulitic structures in opaque materials. Changes in microstructure accompany increased “hard” segment and are not affected by “soft” segment composition. Urethanes with increasing spherulitic content show decreasing tackiness accompanied by decreasing laminate impact resistance. Dynamic mechanical spectra show sharp low temperature loss peaks (240°K) ascribable to Tg of soft segments and an additional broad loss shoulder around 140°K which sharpens as impact resistance decreases and urethane content increases.

Polycarbonate-polyvinyl chloride moulding compounds

Abstract: Process for the production of vinyl chloride polymers modified with aromatic polycarbonate, characterized in that mixtures of olefinically unsaturated monomers containing at least 70 % by weight of vinyl chloride are polymerized by radical polymerization in the presence of aromatic polycarbonates, 0 - 100 % by weight of rubber or rubber-modified thermoplastic resin, based on the polycarbonate-modified vinyl chloride polymer, being added before or after polymerization.

Polyvinyl chloride-polycarbonate alloys

Abstract: Polymer alloys consisting of (a) 20-90% by weight of polyvinyl chloride or copolymers of vinyl chloride with up to 30% by weight of other copolymerizable vinyl compounds, and (b) 10-80% by weight of aromatic polycarbonates.

Electrochromism of indolinobenzospirans dissolved in rigid amorphous polymer matrices

Abstract: The effect of a static electric field on the position of absorption bands of colored stereoisomers of two photochromic compounds of the indolinobenzospiropiran group dissolved in matrices of poly(methyl methacrylate), poly(n-butyl methacrylate), polystyrene, and polycarbonate at room temperature was studied. In the case of matrices with the polymethacrylates the effects observed show that applied electric field produces a shift of thermal equilibrium towards stablization of stereoisomers of larger dipole moment. On the basis of kinetic measurements of attainment of thermal equilibrium on switching the electric field off, the rate constants of their interconversion have been determined. In the case of matrices with polystyrene and polycarbonate, a small red shift only was observed.

Non-opaque flame retardant polycarbonate composition

Abstract: A non-opaque flame retardant polycarbonate composition comprising in admixture an aromatic carbonate polymer and an additive which may be the metal salts of either monomeric or polymeric aromatic ether sulfonic acids; said aromatic carbonate polymer and additive having a refractive index in the range of 1.54 to 1.65.

Crystallization of polycarbonates

Abstract: A moulding composition which comprises a polycarbonate polymer, a plasticizer for said polymer, and a finely divided nucleating agent selected from the group consisting of metal salts of polymers carrying lateral carboxylic groups.

Plastics, partly laminated, partly injection-moulded, vehicle lamp - is composed of polycarbonate and PMMA

Abstract: A vehicle lamp has its transparent pane made of a laminate comprising a colourless base and 1 or several coloured panes functioning as light filters, the bond between base and coloured pane(s) being effected by injection-moulding the one to the other. The inner part of the transparent pane is made of a polycarbonate and the outer part is of PMMA; The claimed construction combines the desirable optical props. of PMMA with the resistance to heat-deformation of the polycarbonate.

Bullet-proof transparent plastics laminate - comprises a polymethylmethacrylate polycarbonate combination

Abstract: A bullet-proof "glass" pane e.g. for use in banks comprises several superposed or adhesively-bonded, transparent, sheets. Specif., there is a pane facing the direction from which a bullet may be expected to be fired, comprising PMMA, with a backing pane made of polycarbonate. May be made thinner than prior-art single PMMA or inorg. glass (i.e., silicate) panes, whilst affording at least equal protection.

Molding thermoplastic resin articles

Abstract: PURPOSE: Molded articles having thin portions 3.5 mm or lower in thickness is obtained by using a thermoplastic resin composition consisting of a copolymer composed of a diene elastomer, a vinyl cyanide and an aromatic vinyl compound, a polycarbonate resin, and talc. COPYRIGHT: (C)1977,JPO&Japio

Flame retardant polycarbonate compositions

Abstract: Polycarbonate articles are provided with enhanced flame retardant characteristics by the addition of ferrocene and derivatives thereof to polycarbonate resins.

Thermoplastic polycarbonate moulding compositions

Abstract: Thermoplastic moulding compositions comprising 1. 5- 95 % by weight of polycarbonates of divalent phenols 2. 95- 5 % by weight of graft copolymers of A. at least one aromatic monovinyl compound B. acrylonitrile and/or its derivatives C. optionally a vinyl or allyl compound on ethylene/vinyl acetate copolymers.

Conjugate polycarbonate fibers and fibrous sheets made thereof

Abstract: A conjugate polycarbonate fiber comprising 95% to 50% by weight of a polycarbonate component and 5 to 50% by weight of a polypropylene component wherein ultrafine fibers composed of the polypropylene component are dispersed and arranged in a bundle-like form in the polycarbonate component as the fiber matrix, whereby the crazing resistance and oil resistance are improved. The conjugate polycarbonate fiber can be made into fibrous sheets and non-woven fabrics. The non-woven fabrics are adapted to be used as insulating layers in electric power cables.

Method of using limiting relations for the study of structural homogeneity of polymers

Abstract: A method is proposed using limited relations to give a quantitative description of the structural homogeneity of polymer compositions. The method is used to characterize mixtures of polyethylene in terms of different rubbers and ABC plastic mixed with polycarbonate.