Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L59/00—Compositions of polyacetals; Compositions of derivatives of polyacetals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/09—Carboxylic acids; Metal salts thereof; Anhydrides thereof
  • C08K5/098—Metal salts of carboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/201—Pre-melted polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/08—Metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
  • B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2359/00—Characterised by the use of polyacetals containing polyoxymethylene sequences only
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/08—Metals
  • C08K2003/0856—Iron

Definitions

• the present invention relates to a polyacetal resin composition for use by kneading with metal powder.
• the present invention also relates to a method for producing a polyacetal resin composition, a metal resin composition containing a polyacetal resin composition and metal powder, and a method for producing a powder injection molded article using the polyacetal resin composition as a binder resin composition.
• a powder injection molding method has been used to manufacture a metal molded product by injection molding a kneaded body obtained by kneading a binder resin composition and a metal powder.
• the powder injection molding method is excellent in terms of the degree of freedom in the shape and material of the molded product, and in terms of dimensional accuracy.
• Polyacetal resin is widely used as an engineering plastic for its mechanical properties, friction/wear properties, chemical resistance, heat resistance, and electrical properties.
• a polyacetal resin can be easily removed by combustion and can reduce the residual amount of ash, so it is also preferable as a binder resin composition for metal powder in the powder injection molding method.
• Patent Document 1 discloses a polyacetal resin composition that is excellent in extrudability, thermal stability, and suppression of foreign matter, and further has excellent dispersibility with metal powder, as well as excellent extrudability and thermal stability, and contains little foreign matter. Furthermore, the present invention discloses an invention that provides a metal resin composition of a metal powder and a polyacetal resin composition in which the metal powder is effectively dispersed.
• This polyacetal resin composition contains (A) 100 parts by mass of a polyacetal resin, (B) 0.005 to 0.2 parts by mass of a nitrogen-containing compound, and (C) 0.01 to 0.8 parts by mass of a fatty acid metal salt.
• the kneaded body (metal resin composition) should have excellent properties of both bending strain and fluidity. is required.
• an object of the present invention is to provide a polyacetal resin composition to be kneaded with metal powder for use.
• the present invention also provides a method for producing a polyacetal resin composition, a metal resin composition containing a polyacetal resin composition and metal powder, and a method for producing a powder injection molded product using the polyacetal resin composition as a binder resin composition. do.
• the present invention includes the following aspects [1] to [8].
• [1] A polyacetal resin composition for use by kneading with metal powder, 100 parts by weight of polyacetal resin (A); Fatty acid metal salt (B) 0.15 to 10.0 parts by weight, The polyacetal resin composition, wherein the fatty acid metal salt (B) is fatty acid zinc, fatty acid magnesium, or a combination thereof.
• [2] The polyacetal resin composition according to [1], wherein the fatty acid of the fatty acid metal salt (B) is a fatty acid having 12 to 28 carbon atoms.
• the fatty acid metal salt (B) is at least one selected from the group consisting of magnesium laurate, zinc laurate, magnesium stearate, zinc stearate, magnesium behenate, zinc behenate, magnesium montanate, and zinc montanate.
• [6] [1] to the polyacetal resin composition according to any one of [5], A metal resin composition comprising a metal powder.
• a method for producing a polyacetal resin composition for use by kneading with metal powder A step of melt-kneading 100 parts by weight of polyacetal resin (A) and 0.15 to 10.0 parts by weight of fatty acid metal salt (B), The above method, wherein the fatty acid metal salt (B) is fatty acid zinc, fatty acid magnesium, or a combination thereof.
• a method for producing a powder injection molded product comprising a step of injecting a kneaded body obtained by melt-kneading a metal powder and a binder resin composition into a mold, The production method, wherein the binder resin composition is the polyacetal resin composition according to any one of [1] to [5].
• the kneaded body (metallic resin composition) has excellent properties of both bending strain and fluidity.
• the polyacetal resin composition of the present invention contains 100 parts by weight of polyacetal resin (A) and 0.15 to 10.0 parts by weight of fatty acid metal salt (B), and fatty acid metal salt (B) is fatty acid zinc, fatty acid magnesium, or a combination thereof.
• the polyacetal resin composition of the present invention is used by kneading with the metal powder (C), and is a binder resin composition for the metal powder (C).
• the polyacetal resin composition may be in solid, powder, strand or pellet form.
• the method for producing the polyacetal resin composition of the present invention includes a step of melt-kneading 100 parts by weight of the polyacetal resin (A) and 0.15 to 10.0 parts by weight of the fatty acid metal salt (B).
• B) is a zinc fatty acid, a magnesium fatty acid, or a combination thereof.
• the melt-kneading step is performed at a temperature at which the polyacetal resin composition melts or higher (generally 180° C. or higher).
• Polyacetal resin (A) is a polymer having an acetal bond: -O-CRH- (wherein R represents a hydrogen atom or an organic group) in a repeating unit, and usually R is a hydrogen atom oxymethylene It has a group (--OCH 2 --) as a main structural unit.
• the polyacetal resin (A) may be a copolymer (block copolymer) or terpolymer containing at least one repeating structural unit other than an oxymethylene group.
• the polyacetal resin (A) has not only a linear structure but also a branched or crosslinked structure generated by using a glycidyl ether compound, an epoxy compound, an allyl ether compound, etc. as comonomers and/or termonomers. good.
• Structural units other than an oxymethylene group include, for example, an oxyethylene group (--OCH 2 CH 2 -- or --OCH(CH 3 )--), an oxypropylene group (--OCH 2 CH 2 CH 2 --, --OCH(CH 3 )CH 2 - or -OCH 2 CH(CH 3 )-), oxybutylene group (-OCH 2 CH 2 CH 2 CH 2 -, -OCH(CH 3) CH 2 CH 2 -, -OCH 2 CH(CH 3 )CH 2 -, -OCH 2 CH 2 CH(CH 3 )-, -OCH(C 2 H 5 )CH 2 - or -OCH 2 CH(C 2 H 5 )-) having 2 to 10 carbon atoms
• An optionally branched oxyalkylene group may be mentioned, and among these, an optionally branched oxyalkylene group having 2 to 4 carbon atoms or an oxyethylene group (-OCH 2 CH 2 -) is prefer
• the content of the comonomer (structural unit other than oxymethylene group) in the polyacetal resin (A) is 0.1% to 20% by weight, 0.5 to 20% by weight, based on the weight of the polyacetal resin (A). %, 1.0-20% by weight, 2.0-20% by weight, 4.0-20% by weight, 1.0-15% by weight, 1.0-10% by weight, 1.0-15% by weight, 1.0-10% by weight, 2.0-15% by weight, 2.0-10% by weight, 2.0-8.0% by weight, 4.0-10% by weight, or 4.0-8.0% by weight % by weight.
• the polyacetal resin (A) may be one after terminal stabilization or one before terminal stabilization. That is, a polyacetal resin composition may be prepared by melt-kneading the polyacetal resin (A) and the fatty acid metal salt (B) after terminal stabilization, or the polyacetal resin (A) before terminal stabilization and the fatty acid metal salt (B) may be melt-kneaded to prepare a polyacetal resin composition.
• the polyacetal resin (A) is preferably a copolymer of a cyclic acetal such as trioxane or tetraoxane and ethylene oxide or 1,3-dioxolane.
• polyacetal resin (A) is an acetal copolymer using 1,3-dioxolane as comonomer.
• Polyacetal resin (A) is 1 to 100 g/10 minutes, 10 to 100 g/10 minutes, 15 to 100 g/10 minutes, 20 to 100 g/10 minutes, measured according to ASTM-D1238 (condition 190°C, load 2.16 kg) 10 min, 25-100 g/10 min, 30-100 g/10 min, 35-100 g/10 min, 40-100 g/10 min, 45-100 g/10 min, or 45-95 g/10 min have.
• polyacetal resin (A) has a melt flow rate of 30-100 g/10 min, 40-100 g/10 min, or 45-95 g/10 min.
• the method for producing the polyacetal resin (A) is not particularly limited, and it is produced by a known method.
• a polyacetal resin (A) having an oxymethylene group and an oxyalkylene group having 2 to 4 carbon atoms as a structural unit is a cyclic oxymethylene group such as a trimer (trioxane) or a tetramer (tetraoxane) of formaldehyde.
• the polyacetal resin (A) can be obtained by bulk polymerization of a cyclic acetal of an oxymethylene group and a cyclic acetal containing an oxyalkylene group having 2 to 5 carbon atoms as a comonomer using a polymerization catalyst.
• a reaction terminator may be used, if necessary, for deactivation of the polymerization catalyst and polymerization growth terminal.
• a molecular weight modifier may be used as necessary to adjust the molecular weight of the polyacetal resin (A).
• the types and amounts of the polymerization catalyst, reaction terminator, and molecular weight modifier are not limited as long as they do not impair the effects of the present invention. good too.
• the polymerization catalyst is, for example, a Lewis acid such as boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentachloride, phosphorus pentafluoride, arsenic pentafluoride, and antimony pentafluoride, or a complex compound of these Lewis acids. or salt compounds; protonic acids such as trifluoromethanesulfonic acid or perchloric acid; esters of protonic acids such as esters of perchloric acid and lower aliphatic alcohols; mixed anhydrides of perchloric acid and lower aliphatic carboxylic acids, etc.
• a Lewis acid such as boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentachloride, phosphorus pentafluoride, arsenic pentafluoride, and antimony pentafluoride, or a complex compound of these Lewis acids
• anhydride of protonic acid or triethyloxonium hexafluorophosphate, triphenylmethylhexafluoroarzenate, acetylhexafluoroborate, heteropolyacid or acid salt thereof, isopolyacid or acid salt thereof, perfluoroalkylsulfonic acid or its acid salt.
• the reaction terminator is, for example, a trivalent organophosphorus compound, an amine compound, an alkali metal, an alkaline earth metal hydroxide, or a combination thereof.
• Molecular weight regulators are, for example, methylal, methoxymethylal, dimethoxymethylal, trimethoxymethylal or oxymethylene di-n-butyl ether.
• the polyacetal resin (A) contains known antioxidants, heat stabilizers, colorants, nucleating agents, plasticizers, fluorescent brighteners, sliding agents, antistatic agents, ultraviolet absorbers, or light stabilizers. You may add additives, such as, as needed.
• Fatty acid metal salt (B) is fatty acid zinc, fatty acid magnesium, or a combination thereof.
• Fatty acid metal salts (B) are salts of fatty acids having 12 to 28 carbon atoms with zinc or magnesium.
• Fatty acids with 12 to 28 carbon atoms are, for example, lauric acid, palmitic acid, stearic acid, behenic acid, montanic acid, 12-hydroxystearic acid, oleic acid or erucic acid.
• the fatty acid zinc is zinc stearate, zinc laurate, zinc behenate or zinc montanate
• the fatty acid magnesium is magnesium laurate, magnesium stearate, magnesium behenate or magnesium montanate.
• the content of the fatty acid metal salt (B) contained in the polyacetal resin composition is 0.15 to 10.0 parts by weight with respect to 100 parts by weight of the polyacetal resin (A).
• the content of the fatty acid metal salt (B) contained in the polyacetal resin composition is 0.15 to 8.0 parts by weight, 0.15 to 6.0 parts by weight, 0.2 to 10.0 parts by weight, 0.2 to 8.0 parts by weight, 0.2 to 6.0 parts by weight, 0.3 to 10.0 parts by weight, 0.3 to 8.0 parts by weight, 0.3 to 6.0 parts by weight, 0.5 to 10.0 parts by weight, 0.5 to 8.0 parts by weight, 0.5 to 6.0 parts by weight, 1.0 to 10.0 parts by weight, 1.0 to 8.0 parts by weight, 1.0 to 6.0 parts by weight, 2.0 to 10.0 parts by weight, 2.0 to 8.0 parts by weight, or 2.0 to 6.0 parts by weight.
• the method for producing the polyacetal resin composition of the present invention includes a melt-kneading step of melt-kneading the polyacetal resin (A) and the fatty acid metal salt (B). Melt-kneading can be performed using, for example, a Banbury mixer, rolls, plastenders, single-screw extruders or twin-screw extruders, or kneaders.
• melt-kneading process Conditions such as temperature and pressure in the melt-kneading process may be appropriately selected in view of conventionally known methods for producing polyacetal resin compositions.
• the melt-kneading step may be carried out at a temperature equal to or higher than the melting temperature of the polyacetal resin, preferably at 180 to 240°C, more preferably at 200 to 220°C.
• a polyacetal resin composition may be produced by melt-kneading the polyacetal resin (A) and the fatty acid metal salt (B) at once so that the content of the fatty acid metal salt (B) is finally as described above, The fatty acid metal salt (B) may be dividedly added in the same step. Once a polyacetal resin composition containing a high concentration of fatty acid metal salt (B) is prepared, it may be diluted by kneading with another polyacetal resin.
• the fatty acid metal salt (B) contained in the polyacetal resin composition is fatty acid zinc, fatty acid magnesium, or a combination thereof, and the content of the fatty acid metal salt (B) is 0.00 per 100 parts by weight of the polyacetal resin (A).
• the kneaded body (metallic resin composition) of the polyacetal resin composition and the metal powder (C) can have excellent properties of both bending strain and fluidity. .
• the metal resin composition of the present invention contains the above polyacetal resin composition and metal powder (C).
• the metal resin composition is produced by melt-kneading the polyacetal resin composition and the metal powder (C).
• the melt-kneading step is performed at a temperature at which the polyacetal resin composition melts or higher (generally 180° C. or higher).
• the metal resin composition (kneaded body) may be solid, powder, strand, or pellet.
• the metal-resin composition has excellent properties of both bending strain and fluidity. Bending strain (%) is measured by performing a three-point bending test on a molded piece of the metal resin composition at a bending speed of 2 mm / min using an apparatus such as "Autograph (registered trademark) AGS-X” manufactured by Shimadzu Corporation. measured as the point where the bending strength is maximum. Fluidity (g/10 minutes) is measured according to ASTM-D1238 at a temperature of 190° C. and a load of 10 kg. The metal resin composition has a bending strain of 1.0% or more and a fluidity of 10 g/10 minutes or more.
• the metal resin composition has a bending strain of 1.0 to 15%, 1.0 to 12%, 1.0 to 10%, 1.0 to 9.5%, or 1.1 to 9.1% and a fluidity of 11 to 2000 g/10 minutes, 11 to 1800 g/10 minutes, or 11 to 1700 g/10 minutes.
• the metal of metal powder (C) is iron, aluminum, magnesium, cobalt, zinc, copper, nickel, titanium, tungsten, or metal compounds or metal alloys based thereon.
• the metal powder (C) is a powder of stainless steel (SUS), and the stainless steel is austenitic stainless steel (SUS300 series), ferritic and martensitic stainless steel (SUS400 series), or precipitation hardening type It is stainless steel (SUS600 series).
• the particle size (average particle size) of the metal powder (C) is not particularly limited. ⁇ 25 ⁇ m, or 1-10 ⁇ m.
• the content of the metal powder (C) in the metal resin composition is 60 to 95 wt%, 65 to 95 wt%, 70 to 95 wt%, 80 to 95 wt%, or 85 to 95% by weight.
• the method for producing a powder injection-molded article of the present invention includes a step of injecting a kneaded body obtained by melt-kneading a metal powder (C) and a binder resin composition into a mold. It is a polyacetal resin composition. Further, the production method includes a step of heating the molded kneaded body in a degreasing furnace or removing the binder resin composition with gaseous acid or the like, and sintering the molded body in a sintering furnace. and forming a powder injection molded article.
• the polyacetal resin composition may contain other stabilizers, nucleating agents, mold release agents, fillers, pigments, lubricants, plasticizers, ultraviolet absorbers, flame retardants, and other stabilizers, as long as the objects of the present invention are not impaired.
• Optional additives such as retardants or flame retardant aids may be added.
• optional additives include glass fibers, glass flakes, glass beads, wollastonite, mica, talc, boron nitride, calcium carbonate, kaolin, silicon dioxide, clay, asbestos, silica, diatomaceous earth, graphite, molybdenum disulfide, Glass fiber, middle fiber, potassium titanate fiber, poron fiber, carbon fiber, aramid fiber, potassium titanate whisker, carbon black, or pigment.
• Polyacetal resin (A) As the polyacetal resin (A-1), a polyacetal resin "Iupital (registered trademark) F40-05" manufactured by Mitsubishi Engineering-Plastics Co., Ltd. was used. The melt flow rate of the polyacetal resin (A-1) is 47 g/10 minutes (measured at 190° C. under a load of 2.16 kg according to ASTM-D1238). As the polyacetal resin (A-2), a polyacetal resin "Iupital (registered trademark) F50-05” manufactured by Mitsubishi Engineering-Plastics Co., Ltd. was used. The melt flow rate of the polyacetal resin (A-2) is 90 g/10 minutes (measured at 190° C. under a load of 2.16 kg according to ASTM-D1238).
• the fatty acid metal salt (B-1) is magnesium stearate "Engineering Magnesium Stearate” manufactured by NOF Corporation.
• Fatty acid metal salt (B-2) is zinc stearate “zinc stearate” manufactured by NOF Corporation.
• Fatty acid metal salt (B-3) is zinc laurate “ZS-3” manufactured by Nitto Kasei Kogyo Co., Ltd.
• Fatty acid metal salt (B-4) is zinc behenate "ZS-7” manufactured by Nitto Kasei Kogyo Co., Ltd.
• Fatty acid metal salt (B-5) is zinc montanate "ZS-8” manufactured by Nitto Kasei Kogyo Co., Ltd.
• Fatty acid metal salt (B-6) is calcium stearate "calcium stearate” manufactured by NOF Corporation.
• Metal powder (C) The metal powder (C) is SUS630 powder (average particle size: about 10 ⁇ m) manufactured by Epson Atmix Corporation.
• Example 1 As shown in Table 1, the polyacetal resin composition of Example 1 was prepared by adding 0.15 parts by weight of magnesium stearate (B-1) to 100 parts by weight of polyacetal resin (A-1). It was prepared by melt-kneading under a nitrogen stream for 20 minutes at a set temperature of 220° C. and a rotation speed of 30 rpm using a kneader “Laboplastomill (registered trademark) 4C150” manufactured by Seisakusho.
• Examples 2 to 47 In the same manner as in Example 1, the polyacetal resin (A) and the fatty acid metal salt (B) were mixed according to the types and blending amounts (parts by weight) of the polyacetal resin (A) and the fatty acid metal salt (B) shown in Tables 1 to 3. Polyacetal resin compositions of Examples 2 to 47 were prepared by melt-kneading.
• Example 2 Similarly to Example 1, in Examples 2 to 41, 20 g (10% by weight) of the polyacetal resin composition and 180 g (90% by weight) of the metal powder (C) were mixed in the kneader at a set temperature of 180. C. and a rotation speed of 60 rpm for 40 minutes under a nitrogen stream, followed by cooling and solidification to prepare a kneaded body (metallic resin composition). Further, in Examples 42 to 47, 60 g (30% by weight) of the polyacetal resin composition and 140 g (70% by weight) of the metal powder (C) were mixed in the kneader at a set temperature of 180°C and a rotation speed of 60 rpm. The mixture was kneaded under a nitrogen stream for 40 minutes and solidified by cooling to prepare a kneaded body (metallic resin composition). The kneaded bodies of Examples 2 to 47 were each crushed using the granulator.
• Comparative Example 11 was prepared according to the composition of Example 5 of Patent Document 1 above.
• Fluidity The fluidity of the crushed kneaded material was measured using a melt indexer “L241” manufactured by Takara Kogyo Co., Ltd. according to ASTM-D1238 at a temperature of 190° C. and a load of 10 kg.
• a fluidity (g/10 minutes) value of 10 (g/10 minutes) or more is considered acceptable and is evaluated as having excellent fluidity characteristics.
• the kneaded bodies (metal resin compositions) of the polyacetal resin compositions and metal powders of Examples 1 to 47 had a bending strain of 1.0% or more and a flow rate of 10 g/10 minutes or more. have characteristics of both sexes.
• the kneaded bodies (metal resin compositions) of the polyacetal resin compositions and the metal powder of Comparative Examples 1 to 12 had a bending strain of 1.0% or more and a flow rate of 10 g/10 minutes or more. It was inferior to those using the polyacetal resin compositions of Examples 1-47.

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• 2021
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