Abstract: The aromatic hydrocarbon resin can be used as a coating material and a resist resin for a semiconductor, and has a high carbon concentration and a low oxygen concentration. A composition for forming an underlayer film for lithography that has excellent etching resistance as an underlayer film for a multilayer resist process, an underlayer film formed with the same, and a pattern forming method using the same are disclosed. An aromatic hydrocarbon is reacted with an aromatic aldehyde in the presence of an acidic catalyst, thereby providing an aromatic hydrocarbon resin that has a high carbon concentration of from 90 to 99.9% by mass and a low oxygen concentration of from 0 to 5% by mass. A composition for forming an underlayer film for lithography contains the resin and an organic solvent, an underlayer film is formed with the same, and a pattern forming method uses the same.

Abstract: The aromatic hydrocarbon resin can be used as a coating material and a resist resin for a semiconductor, and has a high carbon concentration and a low oxygen concentration. A composition for forming an underlayer film for lithography that has excellent etching resistance as an underlayer film for a multilayer resist process, an underlayer film formed with the same, and a pattern forming method using the same are disclosed. An aromatic hydrocarbon is reacted with an aromatic aldehyde in the presence of an acidic catalyst, thereby providing an aromatic hydrocarbon resin that has a high carbon concentration of from 90 to 99.9% by mass and a low oxygen concentration of from 0 to 5% by mass. A composition for forming an underlayer film for lithography contains the resin and an organic solvent, an underlayer film is formed with the same, and a pattern forming method uses the same.

Abstract: A devolatilizer nozzle comprising at least one perforated flow tube having a non-circular cross-section. In an embodiment, the non-circular cross-section has equal to or greater than 3 sides. The non-circular cross-section of said nozzle may be a triangle, diamond, pentagon, hexagon, heptagon, or octagon. A majority of the perforations in the flow tube of said nozzle may have a maximum strand angle of equal to or less than 45 degrees. The nozzle may further comprise tapered holes, which may be formed by a water jet. The nozzle may further comprise a plurality of parallel flow tubes. The nozzle may comprise 304 stainless steel, AL-6XN stainless steel, or LDX 2101 stainless steel.

Abstract: Process for preparation of polyoxymethylenes via polymerization of the monomers a) in the presence of cationic initiators b) and also, if appropriate, in the presence of regulators c), followed by deactivation and discharge from the reactor, which comprises using, as deactivator (d) at least one basic compound having at least 2 amino functions of different reactivity in one molecule.

Abstract: The present invention relates to processes for producing borohydride compounds. In particular, the present invention provides efficient processes and compositions for the large-scale production of borohydride compounds of the formula YBH4 by the reaction of a boron-containing compound represented by the formula BX3 with hydrogen or an aldehyde to obtain diborane and HX, and reacting the diborane with a Y-containing base selected from those represented by the formula Y2O, YOH and Y2CO3 to obtain YBH4 and YBO2. Y is selected from the group consisting of the alkali metals, pseudo-alkali metals, alkaline earth metals, an ammonium ion, and quaternary amines of the formula NR4+, wherein each R is independently selected from hydrogen and a straight- or branched-chain C1-4 alkyl group, and X is selected from the group consisting of halide ions, —OH, —R′ and —OR′ groups, chalcogens, and chalcogenides, wherein R′ is a straight- or branched-chain C1-4 alkyl group.

Abstract: The present invention relates to processes for producing borohydride compounds. In particular, the present invention provides efficient processes and compositions for the large-scale production of borohydride compounds of the formula YBH4 by the reaction of a boron-containing compound represented by the formula BX3 with hydrogen or an aldehyde to obtain diborane and HX, and reacting the diborane with a Y-containing base selected from those represented by the formula Y2O, YOH and Y2CO3 to obtain YBH4 and YBO2. Y is selected from the group consisting of the alkali metals, pseudo-alkali metals, alkaline earth metals, an ammonium ion, and quaternary amines of the formula NR4+, wherein each R is independently selected from hydrogen and a straight- or branched-chain C1-4 alkyl group, and X is selected from the group consisting of halide ions, —OH, —R′ and —OR′ groups, chalcogens, and chalcogenides, wherein R′ is a straight- or branched-chain C1-4 alkyl group.

Abstract: A polyoxymethylene copolymer having a melting point of 167° to 173° C. and containing a low molecular weight polyoxymethylene copolymer in an amount of not higher than 5000 ppm, and a composition thereof. The copolymer is obtainable by subjecting unstable terminal groups to heat treatment in the presence of 0.05 to 50 ppm by weight of a quaternary ammonium compound. Further, the above composition is used for working parts such as a gear and a cam; apparatuses for image, music and telecommunication; interior and exterior parts for an automobile; and the like.

Abstract: A process for producing an oxymethylene copolymer by polymerizing trioxan and 1,3-dioxolan in the presence of a cationically active catalyst, wherein (1) 1,3-dioxolan is used in an amount of 0.01 to 2.9 mol % based on trioxan; and (2) the cationically active catalyst is used in an amount of 1×10−7 to 1.2×10−4 mol based on 1 mol of trioxan. The process of the present invention makes it possible to obtain at a high yield an oxymethylene copolymer which has almost as high mechanical strength and stiffness as an oxymethylene homopolymer while retaining the tenacity and heat stability of an oxymethylene copolymer.

Abstract: To provide a resin material in which various properties of a polyacetal resin such as excellent appearance, slidability and thermal stability are maintained and a rigidity is improved as well. That is, a polyacetal copolymer which is prepared by a copolymerization of 100 parts by weight of trioxane (A), 0.0005 to 2 parts by weight of the component (B), which is a compound (B-1) having at least three glycidyl groups in the molecule or a compound (B-2) having at least two epoxy groups in the molecule, and 0 to 20 parts by weight of a cyclic ether compound (C) copolymerizable with trioxane, and which has a total terminal group amount of 15 to 150 mmol/kg, when (B) is (B-2).

Abstract: This invention concerns a process for the copolymerization of formaldehyde with cyclic ethers, the process comprising combining in a hydrocarbon solvent a cyclic ether, a cationic initiator comprising an anion formed from tetraphenyl borate derivatives, and mixtures thereof, and a cation, and anhydrous formaldehyde. These initiators provide high activity, high cyclic ether incorporation rates, and stability while minimizing the production of by-products.

Abstract: To provide a process for stable and continuous production of a polyacetal resin, mainly comprising a copolymer of 1,3-dioxolane and trioxane under the presence of a catalyst, in a high yield on an industrial scale for a long period of time. In the continuous production of a polyacetal resin by mixing 1,3-dioxolane with boron trifluoride and/or a coordination compound of boron trifluoride and then, mixing the obtained mixture with trioxane to conduct bulk polymerization in a polymerization machine, 1,3-dioxolane is brought into contact with boron trifluoride and/or a coordination compound of boron trifluoride while feeding both at the same direction and they are mixed together for 0.1 to 30 seconds under the condition of at least 0.1 m/sec of the linear velocity of the mixture and subsequently mixed with trioxane.

Abstract: A process for the preparation of polyoxymethylene copolymers, wherein 1,3,5-trioxane is polymerized with generally known comonomers in the presence of a strong protonic acid initiator and in the presence of a formaldehyde dialkyl acetal, and wherein the initiator is dissolved in the formaldehyde dialkyl acetal before admixing to the trioxane and the comonomers.

Abstract: Disclosed is a process for copolymerization of formaldehyde with cyclic ethers in the presence of organic nitro compounds. The process enhances the selectivity for the cyclic copolymer.

Abstract: A branched or crosslinked polyacetal resin is excellent in blow moldability, has impact resistances such as plane impact resistance, and the smoothness of the inner surfaces of moldings produced therefrom, and is suitable for molding, particularly blow molding. It can be produced by the bulk polymerization of (A) trioxane with (B) a cyclic ether and/or cyclic formal and (C) a polyfunctional glycidyl ether compound in the presence of (D) a cationic polymerization catalyst, a mixture prepared by mixing the cyclic ether and/or cyclic formal (B) with the polyfunctional glycidyl ether compound (C) and the cationic polymerization catalyst (D) is added to trioxane (A) to conduct the polymerization.

Abstract: A polyoxymethylene copolymer prepared by copolymerizing a mixture comprising trioxane and 1,3-dioxolane in the presence of at least one polymerization catalyst selected from the group consisting of boron trifluoride, a boron trifluoride hydrate and a coordination complex compound of an organic compound containing an oxygen atom or a sulfur atom with boron trifluoride, wherein the 1,3-dioxolane has a 2-methyl-1,3-dioxolane content of not more than 500 ppm by weight and a 1,3-dioxolane peroxide content of not more than 15 ppm by weight in terms of hydrogen peroxide, and contains at least one hindered phenol in an amount of from 10 to 500 ppm by weight, each based on the weight of the 1,3-dioxolane.

Abstract: In preparing a polyacetal copolymer through copolymerization of trioxane as the principal monomer with a cyclic ether or cyclic formal having at least one carbon-carbon bond as the comonomer, 0.05 to 100 ppm (on the weight basis), based on the total amount of the monomers, of a heteropoly-acid or an acidic salt thereof is used as a polymerization catalyst, and a liquid mixture preliminarily prepared by mixing at least part or the whole of the comonomer with the polymerization catalyst is added to trioxane to effect copolymerization. According to such the process, the polymerization yield and the degree of polymerization (molecular weight) are enhanced, and a polyacetal copolymer having an improved stability can be obtained.

Abstract: The present invention provides a method for producing an oxymethylene copolymer, which comprises:copolymerizing trioxane and a cyclic ether and/or a cyclic formal in the presence of at least one selected from the group consisting of boron trifluoride, boron trifluoride hydrate, and a coordination compound of an organic compound having an oxygen or a sulphur atom with boron trifluoride,volatilizing the residual polymerization catalyst to decrease its amount, by heating the obtained oxymethylene copolymer in an atmosphere of inert gas at or below its melting point, and/or reducing the pressure, without conducting any operation of deactivating the residual polymerization catalyst before volatilizing the residual polymerization catalyst, andstabilizing terminal moities of the oxymethylene copolymer after deactivating residual catalyst or stabilizing terminal moieties of the oxymethylene copolymer directly.

Abstract: Process for producing .alpha.-amino .omega.-ester monoamides such as H.sub.2 N--(CH.sub.2).sub.6 --NH--CO--(CH.sub.2).sub.4 --CO--OCH.sub.3 by reacting a diacid with a diamide at a diamine/diester molar ratio of 0.8 and 1.2 is provided. Additionally, a novel process for producing a polyamide by homopolymerization of an .alpha.-amino .omega.-ester monoamide is provided.

Abstract: A process for preparing a controlled functional density poly(secondary amine) comprising: (a) contacting a polymer containing olefinic unsaturation with carbon monoxide in hydrogen under hydroformylation conditions in the presence of a hydroformylation catalyst to produce a controlled functional density polyaldehyde containing reactive carbon-carbon double bonds, and (b) contacting the polyaldehyde with hydrogen and a primary amine under reductive amination conditions in the presence of a ruthenium-containing imine hydrogenation catalyst or (b.sup.1) contacting the polyaldehyde with a sterically hindered aliphatic or cycloaliphatic primary amine or an aromatic primary amine under reductive amination conditions in the presence of an alkali metal borohydride to produce poly(secondary amine) having a substantially equivalent ratio of secondary amine groups to reactive carbon-carbon double bonds as the ratio of aldehyde groups to reactive carbon-carbon double bonds in the polyaldehyde.

Abstract: A process for preparing a controlled functional density poly(secondary amine) comprising: (a) contacting a polymer containing olefinic unsaturation with carbon monoxide in hydrogen under hydroformylation conditions in the presence of a hydroformylation catalyst to produce a controlled functional density polyaldehyde containing reactive carbon-carbon double bonds, and (b) contacting the polyaldehyde with hydrogen and a primary amine under reductive amination conditions in the presence of a ruthenium-containing imine hydrogenation catalyst or (b.sup.1) contacting the polyaldehyde with a sterically hindered aliphatic or cycloaliphatic primary amine or an aromatic primary amine under reductive amination conditions in the presence of an alkali metal borohydride to produce poly(secondary amine) having a substantially equivalent ratio of secondary amine groups to reactive carbon-carbon double bonds as the ratio of aldehyde groups to reactive carbon-carbon double bonds in the polyaldehyde.

Abstract: Processes for producing a polyoxymethylene copolymer includes forming a crude polyoxymethylene copolymer by subjecting a reaction system containing trioxane, a cyclic ether or cyclic formal comonomer, and a catalyst (e.g., boron trifluoride or a coordination compound thereof) to copolymerization reaction conditions. During copolymerization, both the total content of impurities and catalyst in the copolymerization reaction system are adjusted. In this regard, the impurities content (i.e., those compounds which form unstable end groups in the polyoxymethylene copolymer and/or those compounds having a chain-terminating or chain-transfer function) in the copolymerization reaction system is adjusted to 1.times.10.sup.-2 mole percent or less based on the total monomer amount, while the the content of the catalyst in the copolymerization reaction system to between 1.times.10.sup.-3 to 1.times.10.sup.-2 mole percent based on the total monomer amount.

Abstract: Cyclic polyoxymethylene having a number-average molecular weight of 500 to 5,000 is obtained by solid state cyclization reaction of an alkalidegradative linear oxymethylene homopolymer in the presence of a medium containing a cationic catalyst.The cyclization is effected at 10.degree. to 150.degree. C. for 1 to 500 minutes in an organic liquid medium.The reaction mixture obtained by the cyclization is treated with an alkaline medium to hydrolyze and remove away unreacted linear polyoxymethylene homopolymer, and isolate the cyclic polyoxymethylene.The product has a sharp molecular weight distribution and is useful as a resin improver.

Abstract: There are disclosed a modified oriented polyacetal product, the surface of said product being coated partly or entirely with a phenolic compound-polyacetal composite layer, the application thereof and a process for preparing the same.

Abstract: Benzyl pyridinium or ammonium salts of a non-nucleophilic anion are useful as a cationic polymerization initiator having a heat latency. A variety of resinous compositions containing this initiator is also disclosed.

Abstract: The present invention relates to copolyethers comprising copolymers of 7,oxa-bicyclo(2,2,1)heptane, and its alkyl-derivatives, with one or more single-ring or condensed-rings cycloaliphatic ethers, comprising the characteristic group; ##STR1## wherein R' is hydrogen and R" is H, a halogen, or an alkyl radical containing a small number of carbon atoms, and which may also be halogen-substituted.If the ether contains one ring only, it contains from 5 to 12 atoms in the ring, and if it contains a condensed-ring system, it contains a total number of from 10 to 18 atoms in the rings.Those copolyethers show a anisotropic behaviour in the molten state, and therefore have liquid-crystal properties.

Abstract: Cationic copolymerization of trioxane and trimethylolpropane (TMP) formal or its ester derivatives yields acetal copolymers having pendant functional groups. The TMP formal or ester derivatives of TMP formal may therefore include functional groups selected from hydroxyl or ester moieties which are protected and thus survive the copolymerization with trioxane. These groups may then be present as functional reactive sites for the subsequent synthesis of block copolymers and/or to chemically bind modifiers to the acetal copolymer backbone, for example.

Abstract: Cationic copolymerization of trioxane with glycidyl ester derivatives, preferably glycidyl acrylate derivatives, produces thermally stable, usually cross-linked, acetal copolymer. The resulting acetal copolymer will exhibit side chain ester functionality, and particularly side chain vinyl functionality when glycidyl acrylate derivatives are employed, so as to permit its futher reaction with other chemical moieties to achieve an acetal copolymer of modified chemical and/or physical properties.

Abstract: Methods for forming magnetic coatings on a nonmagnetic substrate include the application of a liquid film layer onto the substrate, the film layer being a dispersion of magnetic particles in a liquid resin binder solution which contains trioxane. The trioxane may or may not be removed from the cured layer. Thus, the trioxane may be present as a reactive solvent for the resin binder, in which case, a polymerization initiator for the trioxane is also present in the liquid film layer. The trioxane may then be polymerized in situ on the substrate to yield poly(oxymethylene).

Abstract: Cationic copolymerization of trioxane and 1,2,6-hexanetriol formal (HTF) or its ester derivatives yields acetal copolymers having pendant functional groups. The HTF formal or ester derivatives of HTF may therefore include functional groups selected from hydroxyl or ester moieties which are protected, and thus survive, the copolymerization with trioxane. These groups may then be present as functional reactive sites for the subsequent synthesis of block copolymers and/or to chemically bind modifiers to the acetal copolymer backbone, for example.

Abstract: A process for producing oxymethylene copolymers and terpolymers is disclosed which involves the non-linear addition of gaseous formaldehyde to a cyclic ether having at least two adjacent carbon atoms (1) and, in the case of a terpolymer, to a mixture of at least one (1) and one monoethylenically unsaturated aliphatic diol formal having at least four carbon atoms in its main chain (2), or to a mixture of (1) with a (2), in the presence of a polymerization initiator at a rate controlled so as to conform to a rate determined by kinetic equations that describe the rate of decomposition of trioxane to formaldehyde during conventional copolymerization of trioxane with a cyclic ether. The process and kinetic equations of the invention are applicable to batch reactions, single stream continuous reactions and dual stream continuous reactions.

Abstract: Cationic polymerization of trioxane and a mixture of ester derivatives of .alpha.,.alpha.- and .alpha.,.beta.-isomers of glycerol formal yields acetal terpolymers having pendant functional groups (i.e., ester groups, or hydroxyl groups obtained by hydrolyzing ester groups, pendent from the polymer's backbone). The glycerol formal monomers employed in this invention may include functional groups selected from ester moieties which are protected from, and thus survive, the polymerization process with trioxane. These groups may then be present as functional reactive sites for the subsequent synthesis of block polymers and/or to chemically bind modifiers to the acetal terpolymer backbone, for example.

Abstract: Acetal polymer having a high degree of polymerization is obtained using a catalyst of a heteropoly acid or an acid salt thereof in a small amount. The catalyst is represented by formula:H.sub.x [M.sub.m .multidot.M'.sub.n O.sub.l ]yH.sub.2 O (1)whereinM: a central element constituted of at least one member selected from among P, B, Si, Ge, Sn, As, Sb, U, Mn, Re, Cu, Ni, Ti, Co, Fe, Cr, Th and Ce,M': at least one ligand element selected from among W, Mo, V and Nb, m: 1 to 10, n: 6 to 40, l: 10 to 100, x: an integer of 1 or above, and y: 0 to 50.

Abstract: There are provided new elastomeric copolymers of about 15 to 45 mol %, preferably about 25 to 35 mol % trioxane, about 55 to 85 mol %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer. The elastomeric copolymers may be prepared by mixing said monomers in a substantially dry state and under an inert atmosphere with a cationic polymerization catalyst, e.g., p-nitrobenzenediazonium tetrafluoroborate. The elastomeric copolymers have a strong interaction with moldable, crystalline acetal polymers comprising at least 85 mol % of polymerized oxymethylene units and may be used as a blending agent with such crystalline acetal polymers or as a bonding agent to improve the adhesiveness of the crystalline acetal polymer to other materials.

Abstract: Cyclic formals, other than trioxane, form macromers with an olefinically unsaturated alcohol which functions as a propagating species to form a macromer of polyformal having a molecular weight generally less than about 10,000. A cationically ring-openable ether may be used to provide a polyether spacer in the alkenyl alcohol so that the macromer of polyformal formed contains a polyether block. Thus, the polyformal macromer may have a acryloyl, allyl, or styryl head group. Macromers of polyformal block copolymers are formed sequentially by first forming the block of first formal and then without isolating the macromer so formed, sequentially polymerizing a second formal monomer to form the second formal block. A macromer of randon copolymer may be formed with one or more cyclic formals or a cyclic ether. Macromers of random copolymers may also be formed with formaldehyde or trioxane.

Abstract: Oxymethylene polymers are prepared by the continuous polymerization of trioxane using as a catalyst a blend of boron trifluoride gas and nitrogen gas. Oxymethylene polymers are used in the manufacture of plumbing fixtures, pipes, automobile body parts and a variety of other articles.

Abstract: Copolymers containing oxymethylene and 2-fluoromethoxyethylene repeat units. These copolymers, of improved heat stability, may be prepared by copolymerizing trioxane with a derivative of a cyclic ether whose molecule contains at least two adjacent carbon atoms and in which an oxymethylene group carries a fluoromethyl substituent, especially epifluorohydrin.

Abstract: A process for producing an oxymethylene copolymer by copolymerizing trioxane with at least one cyclic comonomer selected from the group consisting of cyclic ethers and cyclic formals, said process comprising(1) polymerizing trioxane alone or with a cyclic comonomer in the presence of a polymerization catalyst until the conversion of trioxane reaches 10 to 95%, and(2) thereafter adding a cyclic comonomer and a polymerization catalyst to the reaction system and continuing the polymerization.

Abstract: Compositions comprising an oligomer which (a) comprises the repeating unit (Ar--CHR), and where Ar is an aromatic group and R is hydrogen or a hydrocarbyl group or hydrogen, (b) has pendant and/or terminal groups which include inter alia acyloxymethyl, hydroxymethyl and carboxyl, and (c) has a functionality between 0.5 and 10, and processes for the preparation thereof are described. These compositions may be used in dental, electrical and electronic applications.

Abstract: The polymer or a copolymer of trioxane copolymer is manufactured by adding 0.001 to 2.0 wt. % of a stereo-hindering phenol to the monomer mixture in advance to the polymerization step and polymerizing trioxane and an optional co-monomer in the presence of a cationic, active catalyst and said phenol.

Abstract: A trioxane copolymer is manufactured by adding to trioxane and a co-monomer, 0.0001 to 2.0 percent by weight, based on the total weight of the monomers, of one or more sterically hindered phenols, then co-polymerizing the resultant mixture in the presence of a cation-active catalyst, and then treating the resultant copolymer by heating it at a temperature which is higher than the melting point of the copolymer to melt the copolymer and decompose and remove unstable parts of the copolymer.

Abstract: A copolymer of formaldehyde with a cyclic formal is continuously prepared by feeding formaldehyde, the cyclic formal and 0.1-20 weight parts, per 100 weight parts of formaldehyde, of an inert organic solvent to a biaxial mixer where the formaldehyde is copolymerized with the cyclic formal in the presence of boron trifluoride or an ether complex thereof.

Abstract: A process for preparing a thermoplastic poly(imidesulfone) is disclosed. This resulting material has thermoplastic properties which are generally associated with polysulfones but not polyimides, and solvent resistant which is generally associated with polyimides but not polysulfones. This system is processable in the 250.degree.-350.degree. C. range for molding, adhesive and laminating applications. This unique thermoplastic poly(imidesulfone) is obtained by incorporating an aromatic sulfone moiety into the backbone of an aromatic linear polyimide by dissolving a quantity of a 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) in a solution of 3,3'-diaminodiphenylsulfone and bis(2-methoxyethyl)ether, precipitating the reactant product in water, filtering and drying the recovered poly(amide-acid sulfone) and converting it to the poly(imidesulfone) by heating.

Abstract: An oxymethylene copolymer produced from trioxane, a cyclic ether and/or a cyclic formal in the presence of a cationic polymerization catalyst is contacted with a deactivating agent for the catalyst in the state of gas phase at a temperature of 160.degree. C. or lower to deactivate the cationic polymerization catalyst rapidly and completely without causing degradation of the copolymer produced.

Abstract: A continuous polymerization method to obtain polymer production in the form of fine particles from a liquid polymerization medium; the reaction being conducted in a polymerization reactor wherein mixing is effected by the action of a plurality of elliptical paddles mounted on each of dual rotating shafts, characterised in that the dual shafts are rotated in reverse directions to each other, and the paddles being enclosed by walls of the reactor with the inside surface of the walls closely defining the surface generated by the rotation of the ends of both sets of paddles; and with the ends of major axes of the elliptical paddles on one rotating shaft periodically approaching the ends of minor axes of the corresponding elliptical paddles on the other rotating shaft to effect a mixing action as well as a longitudinal shearing action across a notional interface between the two shafts. The method is particularly useful for the polymerization of trioxane.

Abstract: This invention relates to "comb" polymers having high molecular weight and related structurally to polyoxymethylene, but having improved thermal stability. In addition, this invention relates to a method for preparing these high molecular weight "comb" polymers and teaches a process which exhibits reduced reactor fouling and produces a free-flowing powder. Generally the improved polymer is made by copolymerizing trioxane with polyanhydride or copolymerizing trioxane with copolymers of olefins and anhydrides. The improved polymer can optionally be reacted with agents known to react with terminal hydroxy groups to end-cap the polymer.

Abstract: A polyacetal suitable for moldings which are excellent in lubricity, wear and antistatic properties, which has at least one terminal of its linear polymer molecule capped with an alkylene oxide adduct of an alcohol or a carboxylic acid, which adduct is of the formula ##STR1## wherein R.sub.o is a hydrogen atom, alkyl group, substituted alkyl group, aryl group, or substituted aryl group, R.sub.o 's may be the same or different, R.sub.1 is an alkyl group, substituted alkyl group, aryl group, or substituted aryl group, R.sub.2 is a hydrogen atom, alkyl group, substituted alkyl group, aryl group, or substituted aryl group, m is from 2 to 6, and n is from 1 to 1,000; the number average molecular weight of said polyacetal being in the range from 10,000 to 500,000 excluding the terminal group.

Abstract: A process for producing a polyacetal homopolymer or copolymer which comprises continuously feeding a liquid starting mixture containing molten trioxane and a catalyst and optionally a comonomer through a feed opening of a reactor, said reactor being a continuously stirring-type mixer having two stirring shafts having a plurality of plate-like paddles fixed thereto the cross-section of each of said paddles taken perpendicularly of the axial direction of the stirring shaft having a shape of a convex lens, an ellipse or a quasipolygon inscribing a phantom circle at each vertex, one of said paddles facing another paddle fixed to the other stirring shaft and said one paddle being positioned such that it rotates while the edges thereof keep a slight clearance from the inner surface of the barrel and the other paddle; polymerizing the starting mixture while moving it toward the discharge opening by the rotation of the paddles, the improvement wherein the profiles of the paddles are changed, or the arrangement of the

Abstract: 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.

Abstract: A process for the preparation of polyoxymethylene copolymers, wherein 1,3,5-trioxane is polymerized with generally known comonomers in the presence of a strong protonic acid initiator and in the presence of a formaldehyde dialkyl acetal, and wherein the initiator is dissolved in the formaldehyde dialkyl acetal before admixing to the trioxane and the comonomers.

Abstract: Dihydroxy-terminated copolyformals formed fromA. formaldehyde andB. a diol comonomer mixture of(1) 1,2-bis(2-hydroxyethyl)-1,2-dicarbadodecaborane(12) and(2) a fluorodiol which is HOCH.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CH.sub.2 HOCH.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CH.sub.2 OH, HOCH.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2 CF.sub.2 CH.sub.2 OH, HOCH.sub.2 CF.sub.2 OCF.sub.2 CF.sub.2 OCF.sub.2 CH.sub.2 OH, HOCH.sub.2 CH.sub.2 (CF.sub.2).sub.2 CH.sub.2 CH.sub.2 OH, HOCH.sub.2 CH.sub.2 (CF.sub.2).sub.4 CH.sub.2 CH.sub.2 OH, HOCH.sub.2 CH.sub.2 (CF.sub.2).sub.6 CH.sub.2 CH.sub.2 OH, HOCH.sub.2 CH.sub.2 (CF.sub.2).sub.8 CH.sub.2 CH.sub.2 OH, HOCH.sub.2 CH.sub.2 (CF.sub.2).sub.10 CH.sub.2 CH.sub.2 OH, or mixtures thereof. A fraction of the fluorodiol may be replaced with an equal number of moles of a suitable nitrodiol.