92 results about "Acetal copolymer" patented technology

This invention relates to iodonium salts, acetal copolymers and polymer binders comprising functional groups capable of undergoing cationic or radical polymerization, their method of preparation and their use in the preparation of coating solutions and coatings. This invention also relates to coatings containing the iodonium salts, acetal copolymers and/or polymer binders and to negative working lithographic printing plates comprising these coatings.

A polyacetal resin composition comprises a polyacetal resin having a trioxane content of not more than 100 ppm (preferably not more than 50 ppm, and more preferably not more than 10 ppm) and at least one stabilizer selected from the group consisting of an antioxidant, a formaldehyde emission inhibitor, a processing stabilizer and a heat stabilizer. The polyacetal resin may be a polyacetal resin (particularly a polyacetal copolymer) in which the trioxane amount is reduced by a solvent treatment and/or a heat treatment. Moreover, the polyacetal resin composition may further contain at least one additive selected from the group consisting of a weather (light)-resistant stabilizer, an impact resistance improver, a gloss control agent, a sliding improver, a coloring agent, and a filler. Such a polyacetal resin composition can reduce the amount of trioxane elution and/or the amount of a volatile organic compound from a molded product thereof.

Described herein are novel thermally reactive near-infrared absorbing acetal copolymers that undergo chemical and physical changes upon exposure to near-infrared radiation. Also described are the methods of preparation of the novel acetal copolymers starting either with vinyl-alcohol polymers or with acetal copolymers. Also described are the methods of use of the new near-infrared absorbing acetal copolymers in coatings used in lithographic offset printing plates that can be directly imaged with near-infrared laser imaging devices in computer-to-plate and digital offset printing technologies. The novel acetal copolymers are also useful in photoresist applications, rapid prototyping of printed circuit boards and chemical sensor development.

The present invention provides a polyacetal resin composition having excellent processability and stability, significantly suppressing the amount of formaldehyde generated from the molded article thereof, and preventing the bleeding of blending components. Specifically, to 100 parts by weight of (A) a polyacetal copolymer in which the amount of hemiformal terminal group is 1.0 mmol/kg or less, the amount of formyl terminal group is 0.5 mmol/kg or less, and the amount of unstable terminal group is 0.5% by weight or less, there are added: 0.01 to 3 parts by weight of (B) a hindered phenol-based antioxidant; 0.01 to 1 part by weight of (C) a hydrazide compound; and 0.01 to 1 part by weight of a compound selected from (D) an isocyanate compound, an isothiocyanate compound, and a modified compound thereof.

The present invention provides a polyacetal resin composition having a metallic appearance, suppressing the generation of volatile organic compound (VOC), in particular formaldehyde from the molded article thereof to an extremely low level and giving excellent weathering (light) resistance. Specifically, (A) 100 parts by weight of a polyacetal copolymer containing 1.0 mmol/kg or smaller of a hemiformal terminal group, 2.0 mmol/kg or smaller of a formyl terminal group, 0.5 wt % or smaller of an unstable terminal group, (B) 0.03 to 0.30 part by weight of a hindered phenol-based antioxidant, (C) 0.01 to 1 part by weight of a guanamine compound, (D) 0.2 to 1 part by weight of a hindered amine-based stabilizer, and (E) 0.1 to 1 part by weight of an ultraviolet absorber, and (F) 1 to 20 parts by weight of a metallic pigment are blended together.

The invention discloses a preparation method of cross-linkable acetal copolymer. The preparation method is characterized in that: ternary polymerization of (a) trioxymethylene (TOX), (b) dioxolane (DXL) or cyclohexene oxide (CHO) and (c) a triethoxysilane compound with an epoxy group is catalyzed under a water-free and oxygen-free condition in the presence of an initiator BF3 complex or HClO4, wherein the triethoxysilane compound is shown as a formula 1 or 2; R is an alkyl group or aryl group containing 1-18 carbon atoms or a halogen-substituted group containing heteroatoms N, O, S and P, containing no active hydrogen and containing 1-18 carbon atoms; and R2 is an alkyl group containing 1-8 carbon atoms.

The invention provides a manufacturing method of polyacetal copolymer. During the process of copolymerization between trioxacyclohexane and cyclic ether/cyclic formal, the scales on the feeding part of the polymerization device are reduced, and the tar-liked precipitate caused by the catalyst will not appear, so the device can be operated stably for a long term even if the operation conditions are changed, and only a little of catalyst can maintain the polymerization yield. Before the copolymerization between trioxacyclohexane and cyclic ether/cyclic formal, a polymerization catalyst should be mixed with an organic solvent at first, then cyclic ether and/or cyclic formal is added into the solvent, and finally the mixture and trioxacyclohexane are fed into a polymerization reactor.

To provide a polyacetal resin material in which an excellent sliding property is given and the appearance, dimensional precision, mechanical properties, etc. of the molded article thereof are improved as well. That is, a branched polyacetal resin composition, comprising 100 parts by weight of a branched polyacetal copolymer (A) having an oxymethylene group as the main repeating unit and having a specific branching unit, and0.5 to 40 parts by weight of at least one polymer (B) selected from the group consisting of the following polymer (B-1) and (B-2), i.e.polymer (B-1): a graft or block copolymer prepared from an olefin polymer (b-1) and at least one vinyl polymer (b-2); andpolymer (B-2): a modified olefin polymer in which an olefin polymer (b-3) is modified with at least one compound selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride and derivatives thereofand/or 0.1 to 5 parts by weight of a lubricant (C).

The present invention provides a polyacetal resin composition having excellent processability and stability, significantly suppressing the amount of formaldehyde generated from the molded article thereof, and preventing the bleeding of blending components. Specifically, to 100 parts by weight of (A) a polyacetal copolymer having 1.0 mmol/kg or less of hemiformal terminal group, 0.5 mmol/kg or less of formyl terminal group, and 0.5% by weight or less of unstable terminal group, there are blended: 0.01 to 3 parts by weight of (B) a hindered phenol-based antioxidant; 0.05 to 1 part by weight of (C) at least one compound selected from a guanamine compound and a triazine compound; and 0.01 to 1 part by weight of (D) a compound selected from an isocyanate compound, an isothiocyanate compound, and a modified compound thereof.

A production method for a polyacetal copolymer that makes deactivation of a catalyst simple and efficient and that achieves a high polymerization yield and high quality using equipment that does not require a cleaning step and a process that involves a simple operation technique. The production method for a polyacetal copolymer uses trioxane as a main monomer and a cyclic ether and/or a cyclic formal having at least one carbon-carbon bond as a comonomer. In the production method, a predetermined heteropoly acid is used as a polymerization catalyst to perform copolymerization, a predetermined salt is added to the reaction product, melt kneading processing is performed, and the polymerization catalyst is deactivated.

The invention relates to a manufacturing method of polyacetal copolymer. The manufacturing method is capable of reducing scales, and can stably and continuously produce high quality polyacetal copolymer in a long term in a high yield. The manufacturing method comprises the following steps: mixing cyclic ether and/or cyclic condensed formaldehyde, a polymerization catalyst, acetal, which is represented by the formula (1), with a low molecular weight, an organic solvent, and an antioxidant to obtain a pre-mixed solution; and then feeding the pre-mixed solution and trioxane into a polymerization machine to carry out polymerization. Formula (1): R-(CH2-O)n-R.... in the formula (1), the R represents a free hydrogen atom, a straight chain alkyl group or a branched alkyl group, a straight chain alkoxyl group or a branched alkoxyl group, or a hydroxyl group, and n represents an integer in a range of 1 to 20.

According to the present invention, a foamed injection molded article of excellent mechanical properties and small surface roughness is obtained by injection-molding a resin composition in which a polyacetal copolymer resin with a crystallization time of 5 minutes or more is impregnated with a fluid in a supercritical state as a foaming agent by use of a mold made of a material having a thermal conductivity of 5 W/m·K or less in at least a part of a surface on a cavity side.

Provided is a polyoxymethylene resin composition which has excellent molding characteristics (releasing property and molding cycle) and suppresses the generation of formaldehyde. Specifically the polyoxymethylene resin composition is prepared by blending (A) 100 parts by weight of a polyacetal copolymer containing 1 mmol/kg or less of hemiformal terminal, mmol/kg or less of formyl terminal, and 0.5% by weight or less of unstable terminal; (B) 0.01 to 20 parts by weight of one or a mixture of two or more of a guanamine compound (b-1) and a hydrazide compound (b-2); and (C) 0.1 to 5 parts by weight of an ester compound having 50% or more of esterification percentage.

A hinged glider mechanism includes a hinge device for pivoted mounting in a chair between a stationary base frame and a seat frame, for supporting the seat frame for oscillatory gliding motion generally longitudinally relative to the base frame. The hinge device is configured for repeated substantially silent pivotal oscillating cycles over an extended life. The hinge device includes a hinge panel consisting essentially of a polymeric material, such as acetal copolymer, that is characterized by a sufficient strength and durability to support the seat frame and a seat occupant during repeated and extended pivotal oscillating cycles without failure and a sufficient lubricity not to generate noise during the repeated and extended pivotal oscillating cycles.

The present invention provides a method for producing a polyacetal copolymer which is less in generation amount of scale, allows a high yield of high quality polyacetal copolymer, and can maintain a polymerizatioin rate. A method of manufacturing a polyacetal copolymer polyethylene, which is performed trioxane with a cyclic ether and / or method for producing the polyacetal copolymer of polymerizable cyclic formals, comprises: a step of preparing a premixed solution from a cyclic ether and / or a cyclic formal, a polymerization catalyst and at least one alcohol represented by the following general formula (1); and a polymerization reaction from the pre-mixed solution and trioxane fed to a the polymerization reactor device, wherein R- (CH2-O) n-H ... (1) (formula (1), R represents a group selected group consisting of hydrogen, straight-chain or branched-chain alkyl group, branched or linear alkoxy and the group consisting of a hydroxyl group in any one. The n represents an integer ranging from 1 to 20).