摘要:
A grafted aromatic polycarbonate resin is produced by melt-kneading a graft precursor comprising a mixture of 35 to 95% by weight of aromatic polycarbonate resin particles and 65 to 5% by weight of vinylic copolymer containing active oxygen, the vinylic copolymer being present in the aromatic polycarbonate resin particles, thereby subjecting to grafting reaction of the aromatic polycarbonate resin and the vinylic copolymer, where the grafting reaction can be sufficiently carried out and thus the grafted polycarbonate resin is useful for molding materials for optical disks, optical lenses, etc. a polymer blend-compatible agent, adhesives, paints, etc.
摘要:
An acetal resin composition comprising(A) an acetal resin,(B) at least one member selected from the group consisting of (1) a polyfunctional cyanic acid ester or its prepolymer, (2) a mixture of a polyfunctional cyanic acid ester or its prepolymer with a polyfunctional maleimide or its prepolymer and (3) a pre-copolymer of a polyfunctional cyanic acid ester and a polyfunctional maleimide,(C) an amine-substituted triazine and/or a cyanoguanidine compound, and(D) an inorganic filler other than glass, and/or an organic filler.
摘要:
In a process for producing a stabilized oxymethylene copolymer which comprises heat-melting an oxymethylene copolymer having unstable, unblocked terminals obtained by the copolymerization of trioxane with a cyclic acetal and/or a cyclic ether to heat decompose it in the presence of available heat stabilizers; the improvement which comprises heating said oxymethylene copolymer having unblocked terminals in a mixer at a temperature between the melting point of said oxymethylene copolymer and a point 100.degree. C. higher than said melting point under a pressure of 0.1 mmHg to a atmospheric pressure for a mean residence time of 5 to 60 minutes, said mixer comprising a casing, a jacket for heating medium fitted over its external wall, and at least two stirring shafts equipped with a plurality of scraping blades disposed in said casing, said stirring shafts being capable of rotating in the same or different directions, and in the meantime, rotating said stirring shafts of said mixer to heat decompose said oxymethylene copolymer while renewing the surface of the molten oxymethylene copolymer.
摘要:
Disclosed is a process for producing a grafted polycarbonate resin for optical use, which comprises adding to an aqueous suspension of an aromatic polycarbonate resin having radical-polymerizable unsaturated terminal group on a molecule wherein the aromatic polycarbonate resin has an average particle diameter of 0.1 to 5 mm and an apparent density of 0.2 to 0.9 g/cm.sup.3, a vinyl monomer and a radical-polymerization initiator, heating the aqueous suspension at a lower temperature by 5.degree. C. to 20.degree. C. than the decomposition temperature for a half-life period of 10 hours of the radical-polymerization initiator, thereby impregnating the polycarbonate resin with the vinyl monomer and the radical-polymerization initiator, then elevating the temperature to the range of from a lower temperature by 50.degree. C. to a higher temperature by 30.degree. C. than the decomposition temperature for a half-life period of 10 hours of the radical-polymerization initiator, thereby conducting a graft-polymerization reaction to obtain 90% by weight or more of conversion of vinyl monomer.
摘要:
In a process for producing a stabilized oxymethylene copolymer by heat-melting, at a temperature ranging between the melting point of the copolymer and a temperature 100.degree. C. higher than the melting point in a degassing apparatus in the presence of a heat stabilizer, a crude oxymethylene copolymer of trioxane with a cyclic acetal or cyclic ether, to decompose and eliminate the instable portions of the copolymer, the improvement which comprises using as the degassing apparatus in heat stabilizing the crude oxymethylene copolymer a combination of (A) an extruder and (B) a surface renewing-type mixer, and carrying out the operation by first feeding a crude oxymethylene copolymer to said extruder (A) to heat-melt and decompose 30-90% by weight of the instable portions of the crude copolymer, removing the decomposed gas via a vent provided in said extruder, and thereafter introducing the molten resin continuously to said surface renewing-type mixer (B) where substantially all of the remaining instable portions of the oxymethylene copolymer are heat-decomposed until the content of the instable portions falls below about 2 wt. %, thereby heat stabilizing the copolymer; said extruder (A) having a single or a plurality of shafts, said surface renewing-type mixer functioning to mix and knead the resin thereby constantly renewing the surface of the resin to volatize the volatiles contained therein.
摘要:
In a process for producing an oxymethylene homopolymer or copolymer having improved stability which comprises polymerizing trioxane or a mixture of trioxane and a cyclic ether and/or a cyclic acetal in bulk in the presence of a catalyst which is at least one compound selected from the group consisting of boron trifluoride, boron trifluoride hydrate and coordination compounds of boron trifluoride with organic compounds containing an oxygen or sulfur atom, the improvement which comprises performing the bulk polymerization without destroying the bulk polymerization system, or which comprises adding a tertiary phosphine compound to the polymerization system to deactivate the catalyst, before the polymerization system formed by the bulk polymerization is destroyed.
摘要:
A method of producing polycarbonate resin pellets containing very less residual organic solvent and low molecular weight volatile matters and having a high transparency by melt-kneading a polycarbonate resin powder in an extruder equipped with a screw having a material seal mechanism, and vents, and devolatilizing the residual organic solvent and/or the low molecular weight volatile matters at the vent portion and then extruding the molten resin. The polycarbonate resin pellets are suitable for optical grade articles and automobile lenses.
摘要:
A process for producing a low-particle-content transparent thermoplastic resin solution, which comprises centrifuging a solution of a transparent thermoplastic resin containing free water to separate it into a resin solution phase, an aqueous phase and an intermediate layer, and separating the resin solution phase from the aqueous phase and the intermediate layer. By this process, the number of particles having a size of at least 0.5 .mu.m in the resin solution can be decreased to 10,000 or less, preferably substantially zero, per gram of the transparent thermoplastic resin.
摘要:
An acetal resin composition comprising an acetal resin and a low molecular weight polycarbonate compound having an intrinsic viscosity of 0.2 dl/g or less in methylene chloride at 25.degree. C. and, optionally, an organic or inorganic filler is disclosed. Said composition has improved surface gloss and weather resistance.
摘要:
A process for continuously producing an oxymethylene polymer by continuously polymerizing a starting monomer containing at least 50 mole% of trioxane in bulk in the presence of a catalyst, which comprises feeding the starting monomer into a first-stage polymerization reactor having a self-cleaning action to perform a first-stage polymerization reaction until the conversion reaches 40 to 70%, withdrawing the reaction mixture as a powder from the outlet of the first-stage polymerization reactor, feeding the reaction mixture into a second-stage polymerization reactor having a stirring action to perform a second-stage polymerization reaction until the conversion reaches 95 to 100%, and then withdrawing the polymerization product as a powder from the outlet of the second-stage polymerization reactor.