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WO2021002316A1 - Resin composition and molded article - Google Patents

Resin composition and molded article Download PDF

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Publication number
WO2021002316A1
WO2021002316A1 PCT/JP2020/025471 JP2020025471W WO2021002316A1 WO 2021002316 A1 WO2021002316 A1 WO 2021002316A1 JP 2020025471 W JP2020025471 W JP 2020025471W WO 2021002316 A1 WO2021002316 A1 WO 2021002316A1
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WO
WIPO (PCT)
Prior art keywords
resin composition
core
shell
elastomer
resin
Prior art date
Application number
PCT/JP2020/025471
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French (fr)
Japanese (ja)
Inventor
裕太 山元
Original Assignee
三菱エンジニアリングプラスチックス株式会社
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Filing date
Publication date
Application filed by 三菱エンジニアリングプラスチックス株式会社 filed Critical 三菱エンジニアリングプラスチックス株式会社
Priority to JP2021530010A priority Critical patent/JPWO2021002316A1/ja
Publication of WO2021002316A1 publication Critical patent/WO2021002316A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • C08L51/04—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to rubbers
    • 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

Definitions

  • the present invention relates to a resin composition and a molded product.
  • the present invention relates to a resin composition containing a polyacetal resin as a main component.
  • Polyacetal resins are used in a wide range of applications as plastics having excellent mechanical properties, electrical properties, and chemical properties such as chemical resistance. Further, in order to impart various functions to the polyacetal resin, it is being studied to add various additives. For example, a composition composed of a polyacetal resin and a thermoplastic polyurethane has been proposed and put into practical use. However, since the composition composed of the polyacetal resin and the thermoplastic polyurethane has poor compatibility, it tends to cause delamination, and has a problem that the adhesion of the weld portion formed by injection molding is poor. It is known (Patent Document 1).
  • An object of the present invention is to provide a resin composition and a molded product having excellent adhesion of a weld portion and excellent weather resistance under such a situation.
  • a resin composition containing a polyacetal resin and a core-shell type elastomer wherein the resin composition is molded into a 1.6 mm-thick test piece having a weld portion in the center, and at 10 mm / min according to ASTM D638.
  • the resin composition contains 60 to 95% by mass of the polyacetal resin and 40 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). ), The resin composition according to ⁇ 1>. ⁇ 3> The resin composition contains 70 to 95% by mass of the polyacetal resin and 30 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). ), The resin composition according to ⁇ 1>.
  • the resin composition according to one. ⁇ 5> The resin composition is molded into a flat plate test piece of 100 mm ⁇ 40 mm ⁇ 2 mm, and is measured with a sunshine weather meter at 83 ° C. (black panel temperature), no rain, and an optical filter: 60 in a test environment of # 255.
  • ⁇ E * (( ⁇ L *) 2 + ( ⁇ a *) 2 + ( ⁇ b *) 2 ) 1/2 ⁇ 6>
  • L / D which is the ratio of the screw length L (mm) of the extruder to the screw diameter D (mm), includes 20 ⁇ (L / D) ⁇ 100.
  • the resin composition of the present invention is a resin composition containing a polyacetal resin and a core-shell type elastomer, and the resin composition is molded into a 1.6 mm thick test piece having a weld portion in the center, and ASTM D638.
  • the weld elongation when pulled at 10 mm / min is 20% or more
  • the core-shell type elastomer contains a butadiene-containing rubber
  • the shell portion contains an acrylic resin.
  • polyacetal resins are expected to have various uses, and one of them is expected to have weather resistance. Then, in the present invention, a weather-resistant resin composition was obtained by using a specific core-shell type elastomer.
  • a core-shell type elastomer is used instead of the thermoplastic polyurethane, and further, the core-shell type elastomer having small particles is adjusted so as to be dispersed and present in the vicinity of the weld portion, thereby increasing the weld elongation. This has succeeded in improving the adhesion of the weld portion.
  • the details of the present invention will be described below.
  • the resin composition of the present invention contains a polyacetal resin.
  • the polyacetal resin is not particularly limited, and even if it is a homopolymer containing only a divalent oxymethylene group as a constituent unit, it has a divalent oxymethylene group and a divalent oxyalkylene having 2 to 6 carbon atoms. It may be a copolymer containing a group as a constituent unit.
  • Examples of the oxyalkylene group having 2 to 6 carbon atoms include an oxyethylene group, an oxypropylene group, and an oxybutylene group.
  • the ratio of the oxyalkylene group having 2 to 6 carbon atoms to the total number of moles of the oxymethylene group and the oxyalkylene group having 2 to 6 carbon atoms is not particularly limited, and is 0.5 to 10 mol. It may be%.
  • trioxane is usually used as a main raw material.
  • cyclic formal or cyclic ether can be used.
  • Specific examples of cyclic formal include 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepan, 1,3-dioxocan, 1,3,5-trioxepan, 1,3,6-trioxocan and the like.
  • Specific examples of the cyclic ether include ethylene oxide, propylene oxide and butylene oxide.
  • 1,3-dioxolane may be used as a main raw material
  • 1,3-dioxane may be used as a main raw material
  • 1,3-dioxepan may be used as the main raw material.
  • the amount of hemiformal terminal groups, the amount of formyl terminal groups, and the amount of terminal groups unstable to heat, acid, and base are small.
  • the hemiformal terminal group is represented by -OCH 2 OH
  • the formyl terminal group is represented by -CHO.
  • polyacetal resin in addition to the above, the polyacetal resins described in paragraphs 0018 to 0043 of JP2015-07724A can be used, and these contents are incorporated in the present specification.
  • the resin composition of the present invention preferably contains a polyacetal resin in an amount of 60% by mass or more, more preferably 65% by mass or more, further preferably 70% by mass or more, and further preferably 75% by mass or more. It is even more preferable to contain 78% by mass or more.
  • the upper limit is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. Within such a range, the effects of the present invention tend to be exhibited more effectively.
  • the resin composition of the present invention may contain only one type of polyacetal resin, or may contain two or more types of polyacetal resin. When two or more types are included, the total amount is preferably in the above range.
  • the resin composition of the present invention contains a butadiene-containing rubber and a core-shell type elastomer containing an acrylic resin in the shell portion.
  • a resin composition having excellent weather resistance can be obtained by using a predetermined core-shell type elastomer.
  • the core-shell type elastomer is a polymer having a multi-layer structure having a core portion and a shell layer covering a part or all of the core portion, and Kaneka Corporation's Kaneace series and Mitsubishi Chemical Corporation's Metabrene series are known.
  • the Kaneka M910 series manufactured by Kaneka Corporation can be preferably used.
  • the core-shell type elastomer by using the core-shell type elastomer, it is possible to prevent the particles from being crushed even in the vicinity of the weld portion. Further, by selecting the type of core-shell elastomer so that the average secondary particle diameter of the core-shell elastomer existing in the vicinity of the weld portion is within a predetermined range, small particles of the core-shell elastomer are dispersed in the vicinity of the weld portion. be able to. As will be described in more detail later, the secondary average particle size of the core-shell elastomer can be adjusted to be within a predetermined range by adjusting various conditions during melt-kneading.
  • the type of core-shell elastomer used in the present invention is not particularly limited, but a core-shell elastomer containing butadiene-containing rubber and an acrylic resin in the shell portion is preferable. When such a core-shell type elastomer is used, the effect of the present invention is exhibited more effectively.
  • the core-shell elastomer used in the present invention is the ratio of the longitudinal elastic modulus of the shell portion of the core-shell elastomer to the longitudinal elastic modulus of the polyacetal resin (shell) measured using an SPM (scanning probe microscope, cantilever spring constant: 9 N / m).
  • the longitudinal elastic modulus of the portion / the longitudinal elastic modulus of the polyacetal resin) is preferably 0.08 or more, more preferably 0.10 or more, further preferably 0.15 or more, and 0.2 or more. Is more preferable.
  • the upper limit value of the longitudinal elastic modulus of the shell portion / the longitudinal elastic modulus of the polyacetal resin is not particularly determined, but is practically 1.0 or less.
  • the longitudinal elastic modulus is measured according to the description of Examples described later.
  • the resin composition of the present invention preferably contains a core-shell type elastomer in an amount of 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.
  • the upper limit is preferably 40% by mass or less, more preferably 35% by mass or less, further preferably 30% by mass or less, further preferably 25% by mass or less, and 22% by mass or less. Is even more preferable. Within such a range, the effects of the present invention tend to be exhibited more effectively.
  • the resin composition of the present invention may contain only one type of core-shell type elastomer, or may contain two or more types. When two or more types are included, the total amount is preferably in the above range.
  • the resin composition of the present invention contains 60 to 95% by mass (preferably 70 to 95% by mass) of the polyacetal resin and 40 to 5% by mass (preferably 30 to 5% by mass) of the core-shell elastomer (however, polyacetal).
  • the total of the resin and the core-shell type elastomer does not exceed 100% by mass).
  • the total amount of the polyacetal resin and the core-shell type elastomer preferably occupies 95% by mass or more, and more preferably 98% by mass or more of the resin composition.
  • the resin composition of the present invention may contain any conventionally known additives and fillers as long as the object of the present invention is not impaired.
  • the additives and fillers used in the present invention include thermoplastic resins other than polyacetal resins, ultraviolet absorbers, antioxidants, stabilizers, formaldehyde traps, antistatic agents, carbon fibers, glass fibers, and glass flakes.
  • examples include potassium titanate whiskers.
  • the resin composition of the present invention also does not contain thermoplastic polyurethane, or the content of the thermoplastic polyurethane is 3% by mass or less (preferably 1% by mass or less, more preferably 0.% by mass) of the content of the core-shell type elastomer. 1% by mass or less) is preferable. With such a configuration, the weld adhesion can be further improved.
  • the resin composition of the present invention is molded into a multipurpose test piece having a thickness of 4 mm, and the flexural modulus measured according to ISO178 is preferably 1700 MPa or less, more preferably 1650 MPa or less, and more preferably 1600 MPa or less. More preferred.
  • the lower limit value is not particularly specified, but is practically, for example, 1000 MPa or more, further 1100 MPa or more, 1300 MPa or more, 1400 MPa or more, and 1500 MPa or more.
  • the present invention has high value in that it can be made excellent in weather resistance while improving the softness.
  • the resin composition of the present invention has a weld elongation of 20% or more when molded into a 1.6 mm thick test piece having a weld portion in the center and pulled at 10 mm / min according to ASTM D638, which is 25%.
  • the above is preferable, 30% or more is more preferable, and 35% or more is further preferable.
  • the upper limit of the weld elongation is not particularly defined, but for example, 99% or less, further 90% or less, and 80% or less are practical.
  • the resin composition of the present invention has an average secondary particle diameter of 50 nm or more of the core-shell elastomer present in the weld portion when molded into a 3.2 mm thick test piece having a weld portion in the center.
  • the average secondary particle diameter is preferably 500 nm or less, more preferably 300 nm or less, further preferably 200 nm or less, further preferably 150 nm or less, and further preferably 120 nm or less. Even more preferably, it may be 110 nm or less, and even 100 nm or less.
  • the resin composition is molded into a flat plate test piece of 100 mm ⁇ 40 mm ⁇ 2 mm, and is measured with a sunshine weather meter at 83 ° C. (black panel temperature), no rain, and an optical filter: # 255 for 60 hours.
  • the color difference ( ⁇ E *) of the test pieces before and after the test is preferably 12 or less, more preferably 11 or less, further preferably 10 or less, and even more preferably 9 or less.
  • the lower limit is practically 1 or more.
  • ⁇ E * (( ⁇ L *) 2 + ( ⁇ a *) 2 + ( ⁇ b *) 2 ) 1/2
  • the polyacetal resin composition of the present invention contains the above-mentioned essential components and, if necessary, any of the above-mentioned optional components.
  • the production method thereof is arbitrary, and any conventionally known method for producing a resin composition may be used to mix and knead these raw materials.
  • Examples of the kneading machine include a kneader, a Banbury mixer, and an extruder.
  • the various conditions and devices for mixing and kneading are also not particularly limited, and may be appropriately selected and determined from any conventionally known conditions.
  • the kneading is preferably performed at a temperature equal to or higher than the melting temperature of the polyacetal resin, specifically, a temperature higher than the melting temperature of the polyacetal resin.
  • the following methods can be preferably used in order to suppress the secondary aggregation of the core-shell type elastomer and adjust the average secondary particle size to an appropriate value.
  • the polyacetal resin and the core-shell type elastomer are mixed with a tumbler, extruded by an extruder, formed into a strand, and then cut. There is a method of making pellets.
  • the extruder it is preferable to use a twin-screw extruder because secondary agglutination is likely to occur in a single-screw extruder.
  • L / D which is the ratio of the screw length L (mm) to the diameter D (mm) of the screw, satisfies the relationship of 20 ⁇ (L / D) ⁇ 100, and 25 ⁇ (L / L /). D) It is more preferable to satisfy ⁇ 70.
  • the shape of the die nozzle is not particularly limited, but in terms of pellet shape, a circular nozzle having a diameter of 1 to 10 mm is preferable, and a circular nozzle having a diameter of 2 to 7 mm is more preferable.
  • the term "circle” as used herein is not limited to a circle in a geometrical sense, but includes a circle that is interpreted as a substantially circle in the technical field of the present embodiment.
  • the melting temperature of the resin composition at the time of melt-kneading is appropriately determined in relation to the melting temperature of the resin, but is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, and 190 ° C. or higher. It is more preferable to have. Further, the melting temperature is preferably 250 ° C. or lower, more preferably 230 ° C. or lower. By setting the melting temperature to 170 ° C. or higher, melting is sufficiently performed, and the production amount tends to be remarkably improved. Further, by setting the temperature to 250 ° C. or lower, discoloration of the resin composition due to thermal deterioration can be more effectively suppressed.
  • the screw rotation speed during melt-kneading is preferably 50 to 500 rpm, more preferably 70 to 350 rpm.
  • the screw rotation speed is preferably 50 to 500 rpm, more preferably 70 to 350 rpm.
  • the screw rotation speed is preferably 50 to 500 rpm or more, the core-shell type elastomer can be easily finely dispersed, and the occurrence of secondary aggregation can be suppressed more effectively.
  • the discharge amount is preferably 5 to 1,000 kg / hr, and more preferably 7 to 800 kg / hr.
  • the core-shell type elastomer can be easily finely dispersed, and the occurrence of secondary aggregation can be effectively suppressed. Further, by setting the weight to 1,000 kg / hr or less, heat generation during melt-kneading can be effectively suppressed, and discoloration of the resin composition due to thermal deterioration can be more effectively suppressed.
  • the molded article of the present invention is formed from the polyacetal resin composition of the present invention. Further, the pellet obtained by pelletizing the polyacetal resin composition of the present invention is usually injection-molded to obtain a molded product.
  • the pellet in the present invention is preferably cylindrical, preferably has a diameter of 1 to 10 mm, and more preferably 2 to 7 mm.
  • the term "cylindrical" as used herein means that, in addition to the cylindrical one in the geometrical sense, the one interpreted as a cylindrical one in the technical field of the present invention is included. For example, a shape obtained by cutting a strand discharged from a nozzle having a circular discharge port is included in a columnar shape.
  • a preferable example of the molded product of the present invention is an injection molded product.
  • the injection-molded product is a molded product molded by injection molding, and usually, a fragile portion (weld portion) is formed in a portion where the molten resin joins in the mold.
  • the thickness of the molded product of the present invention preferably has, for example, a portion of 0.005 to 20 mm, and an appropriate thickness can be selected according to the application.
  • the shape of the molded product is not particularly limited and may be appropriately selected depending on the intended use and purpose of the molded product. For example, plate-shaped, plate-shaped, rod-shaped, sheet-shaped, film-shaped, cylindrical, annular, etc.
  • the molded product of the present invention may be a part or a finished product.
  • the polyacetal resin composition of the present invention and a molded product formed from the polyacetal resin composition are widely used in applications requiring weather resistance. Specifically, it is used for vehicle parts, building material parts, electrical / electronic parts, office equipment parts, daily miscellaneous goods parts, and the like. In particular, it is used for parts that are irradiated with ultraviolet rays.
  • Elastomer manufactured by Mitsubishi Chemical
  • Elastomer 4 Core-shell type elastomer containing silicone rubber for the core and acrylonitrile styrene resin for the shell, Metabrene, manufactured by Mitsubishi Chemical Corporation, SRK-200
  • Elastomer 5 Thermoplastic polyurethane, manufactured by BASF, product number: Elastolan S80ASH10
  • Examples 1 to 8, Comparative Examples 1 to 5, Reference Example 1 Each component shown in Tables 1 to 3 was uniformly mixed using a super mixer manufactured by Kawada Seisakusho Co., Ltd. at the ratio (parts by mass) shown in Tables 1 to 3. The obtained mixture was subjected to cylinder temperature (“PCM-30” manufactured by Ikegai Corp.) with a vented twin-screw extruder (“PCM-30” manufactured by Ikegai Corp.) having a screw diameter (D) of 30 mm, a screw length (L) of 760 mm, and a die nozzle diameter of 3.5 mm.
  • PCM-30 cylinder temperature
  • PCM-30 vented twin-screw extruder
  • Pellets of a polyacetal resin composition were produced by melt-shear mixing at a melting temperature of 200 ° C., a screw rotation speed of 120 rpm, and a discharge rate of 10 kg / hour.
  • UR20H manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.
  • ⁇ Flexural modulus> The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C. Next, the dried pellets were injection-molded in accordance with the ISO9998-2 standard by setting the cylinder temperature to 195 ° C. and the mold temperature to 90 ° C. using an injection molding machine. In this way, a multipurpose test piece (ISO test piece) having a thickness of 4 mm was obtained. Next, the 4 mm-thick multipurpose test piece (ISO test piece) is subjected to a bending test at a bending test speed of 2 mm / min according to the method described in ISO178 using a fully automatic bending tester which is a bending tester. , The flexural modulus was measured. As an injection molding machine, EC-100S manufactured by Toshiba Machine Co., Ltd. was used. A fully automatic bending tester manufactured by Shimadzu Corporation was used. The results are shown in Tables 1 to 3 below. The unit is shown in MPa.
  • ⁇ Weld growth> The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C. Next, the dried pellets were set to a cylinder temperature of 195 ° C. and a mold temperature of 90 ° C. using an injection molding machine, and an ASTM tensile test piece (thickness 1.6 mm) having a weld portion in the center. ) was prepared, and a tensile test was performed according to ASTM D638 to measure the weld elongation. As an injection molding machine, EC-100S manufactured by Toshiba Machine Co., Ltd. was used. The results are shown in Tables 1 to 3 below. The unit is shown in%.
  • ⁇ Weather resistance> The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C. Next, using an injection molding machine, the cylinder temperature was set to 215 ° C. and the mold temperature was set to 80 ° C. to prepare a flat plate test piece of 100 mm ⁇ 40 mm ⁇ 2 mm. Using the obtained flat plate test piece, test before and after 60 hours in a test environment of 83 ° C (black panel temperature), no rain, optical filter: # 255 with a sunshine weather meter. The color difference ( ⁇ E *) of one piece was measured by the following method.
  • ⁇ E * (( ⁇ L *) 2 + ( ⁇ a *) 2 + ( ⁇ b *) 2 ) 1/2 It can be said that the smaller ⁇ E * is, the smaller the discoloration property is and the better the weather resistance is.
  • PS-40 manufactured by Nissei Resin Industry Co., Ltd.
  • sunshine weather meter a sunshine weather meter S80 manufactured by Suga Test Instruments Co., Ltd. was used.
  • SE2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. was used. The results are shown in Tables 1 to 3 below.
  • ⁇ Average secondary particle size of elastomer> The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C. Next, the dried pellets were set to a cylinder temperature of 195 ° C. and a mold temperature of 90 ° C. using an injection molding machine, and an ASTM tensile test piece (thickness 3.2 mm) having a weld portion in the center. ) was prepared. From this ASTM tensile test piece, a test piece for scanning electron microscope (SEM) observation was cut out with a diamond knife so as to be parallel to the flow direction at the time of molding and include a weld portion.
  • SEM scanning electron microscope
  • an SEM image was acquired using a scanning electron microscope (SEM). From the obtained SEM image, the average value of the maximum lengths of the island-shaped portions derived from the elastomer was taken as the average secondary particle diameter of the elastomer.
  • SEM scanning electron microscope
  • As an injection molding machine EC-100S manufactured by Toshiba Machine Co., Ltd. was used.
  • the vapor deposition of osmium tetroxide was carried out using a "osmium coater" manufactured by Meiwaforsis Co., Ltd. under the conditions of 8 mA and 60 seconds.
  • SEM scanning electron microscope
  • ⁇ Measurement of longitudinal elastic modulus> A test piece for observation with a scanning probe microscope (SPM) was cut out in the same procedure as the measurement of the average secondary particle size, and a longitudinal elastic modulus image was obtained by a force curve mapping method of the scanning probe microscope (SPM). From the obtained longitudinal elastic modulus image, the longitudinal elastic modulus at a total of 10 points was measured for the polyacetal resin portion. Next, from the longitudinal elastic modulus image, the longitudinal elastic modulus was measured at a total of 10 locations for the shell portion of the core-shell type elastomer. For the non-core shell type elastomer, the longitudinal elastic modulus near the interface with the polyacetal resin was measured.
  • the longitudinal elastic modulus ratio (the longitudinal elastic modulus of the shell portion / the longitudinal elastic modulus of the polyacetal resin) was calculated from the longitudinal elastic modulus of the shell portion of the core-shell type elastomer and the longitudinal elastic modulus of the polyacetal resin.
  • the scanning probe microscope uses "SPM-9700HT” manufactured by Shimadzu Corporation, scanner: 30 ⁇ m ⁇ 30 ⁇ m, cantilever: “AC200 (spring constant 9 N / m)” manufactured by Olympus, sweep speed: 1 Hz, sweep range: 1500 nm, I gain: An elastic modulus image was obtained under 100 conditions.

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Abstract

Provided are a resin composition and molded article having excellent adhesiveness at a weld section and excellent weather resistance. The resin composition contains a polyacetal resin and a core-shell elastomer, and, when molded into a 1.6 mm-thick test piece having a weld section in the center thereof, has a weld elongation of 20% or greater when stretched at 10 mm/min according to ASTM D638 standards. The core-shell elastomer contains a butadiene-containing rubber, and an acrylic resin is included in the shell part.

Description

樹脂組成物および成形品Resin composition and molded product
　本発明は、樹脂組成物および成形品に関する。特に、ポリアセタール樹脂を主成分とする樹脂組成物に関する。 The present invention relates to a resin composition and a molded product. In particular, the present invention relates to a resin composition containing a polyacetal resin as a main component.
　ポリアセタール樹脂は、機械的性質、電気的性質、および、耐薬品性などの化学的性質に優れたプラスチックとして、広範囲の用途で使用されている。
　また、ポリアセタール樹脂に種々の機能を付与するため、各種添加剤を配合することが検討されている。例えば、ポリアセタール樹脂と熱可塑性ポリウレタンとからなる組成物が提案されており、実用化されている。ところが、ポリアセタール樹脂と熱可塑性ポリウレタンからなる組成物は、相溶性が悪いために、層間剥離を引き起こしやすく、射出成形で形成されるウエルド部の密着性が悪いという問題点を有していることが知られている（特許文献１）。 Polyacetal resins are used in a wide range of applications as plastics having excellent mechanical properties, electrical properties, and chemical properties such as chemical resistance.
Further, in order to impart various functions to the polyacetal resin, it is being studied to add various additives. For example, a composition composed of a polyacetal resin and a thermoplastic polyurethane has been proposed and put into practical use. However, since the composition composed of the polyacetal resin and the thermoplastic polyurethane has poor compatibility, it tends to cause delamination, and has a problem that the adhesion of the weld portion formed by injection molding is poor. It is known (Patent Document 1).
特開平０７－１３８４４９号公報Japanese Unexamined Patent Publication No. 07-138449
　上述の通り、ポリアセタール樹脂は広範囲の用途で使用されている。また、射出成形用途での展開が期待される。そのため、ウエルド部の密着性が良好な新規な材料が求められる。また、耐候性に優れた材料が求められる場合もある。
　本発明では、かかる状況のもと、ウエルド部の密着性に優れ、かつ、耐候性に優れた樹脂組成物および成形品を提供することを目的とする。 As mentioned above, polyacetal resins are used in a wide range of applications. It is also expected to be used in injection molding applications. Therefore, a new material having good adhesion of the weld portion is required. In addition, a material having excellent weather resistance may be required.
An object of the present invention is to provide a resin composition and a molded product having excellent adhesion of a weld portion and excellent weather resistance under such a situation.
　上記課題のもと、本発明者が検討を行った結果、下記手段により、上記課題は解決された。
＜１＞ポリアセタール樹脂と、コアシェル型エラストマーを含む樹脂組成物であって、前記樹脂組成物を、ウエルド部を中央に有する１．６ｍｍ厚さの試験片に成形し、ＡＳＴＭ　Ｄ６３８に従い１０ｍｍ／分で引張った時のウエルド伸びが２０％以上であり、前記コアシェル型エラストマーが、ブタジエン含有ゴムを含み、シェル部にアクリル樹脂を含む、樹脂組成物。
＜２＞前記樹脂組成物は、前記ポリアセタール樹脂６０～９５質量％と、前記コアシェル型エラストマー４０～５質量％を含む（ただし、ポリアセタール樹脂とコアシェル型エラストマーの合計が１００質量％を超えることはない）、＜１＞に記載の樹脂組成物。
＜３＞前記樹脂組成物は、前記ポリアセタール樹脂７０～９５質量％と、前記コアシェル型エラストマー３０～５質量％を含む（ただし、ポリアセタール樹脂とコアシェル型エラストマーの合計が１００質量％を超えることはない）、＜１＞に記載の樹脂組成物。
＜４＞前記樹脂組成物は、熱可塑性ポリウレタンを含まないか、熱可塑性ポリウレタンの含有量が、前記コアシェル型エラストマーの含有量の３質量％以下である、＜１＞～＜３＞のいずれか１つに記載の樹脂組成物。
＜５＞前記樹脂組成物を、１００ｍｍ×４０ｍｍ×２ｍｍの平板試験片に成形し、サンシャインウェザーメーターにて、８３℃（ブラックパネル温度）、雨なし、光フィルター：＃２５５の試験環境で、６０時間試験した前後の試験片の色差（ΔＥ＊）が１２以下である、＜１＞～＜４＞のいずれか１つに記載の樹脂組成物。
ΔＥ＊＝（（ΔＬ＊）２＋（Δａ＊）２＋（Δｂ＊）２）１／２
＜６＞前記樹脂組成物を４ｍｍ厚さの多目的試験片に成形し、ＩＳＯ１７８に従って測定した曲げ弾性率が１７００ＭＰａ以下である、＜１＞～＜５＞のいずれか１つに記載の樹脂組成物。
＜７＞前記ＳＰＭ（走査型プローブ顕微鏡、カンチレバーばね定数：９Ｎ／ｍ）を用いて測定したコアシェル型エラストマーのシェル部の縦弾性率とポリアセタール樹脂の縦弾性率の比率（シェル部の縦弾性率／ポリアセタール樹脂の縦弾性率）が０．０８以上である、＜１＞～＜６＞のいずれか１つに記載の樹脂組成物。
＜８＞＜１＞～＜７＞のいずれか１つに記載の樹脂組成物から形成された成形品。
＜９＞射出成形品である、＜８＞に記載の成形品。
＜１０＞＜１＞～＜７＞のいずれか１つに記載の樹脂組成物の製造方法であって、ポリアセタール樹脂とコアシェル型エラストマーをタンブラーで混合した後、押出機にて押出し、ストランド状とした後に切断してペレットとすることを含み、前記押出機のスクリューの長さＬ（ｍｍ）とスクリューの直径Ｄ（ｍｍ）の比であるＬ／Ｄが、２０＜（Ｌ／Ｄ）＜１００の関係を満たし、前記ストランド状とするためのダイノズルが直径１～１０ｍｍである、樹脂組成物の製造方法。 As a result of the examination by the present inventor based on the above problems, the above problems have been solved by the following means.
<1> A resin composition containing a polyacetal resin and a core-shell type elastomer, wherein the resin composition is molded into a 1.6 mm-thick test piece having a weld portion in the center, and at 10 mm / min according to ASTM D638. A resin composition having a weld elongation of 20% or more when pulled, the core-shell type elastomer containing butadiene-containing rubber, and an acrylic resin in the shell portion.
<2> The resin composition contains 60 to 95% by mass of the polyacetal resin and 40 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). ), The resin composition according to <1>.
<3> The resin composition contains 70 to 95% by mass of the polyacetal resin and 30 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). ), The resin composition according to <1>.
<4> Any of <1> to <3>, wherein the resin composition does not contain thermoplastic polyurethane, or the content of the thermoplastic polyurethane is 3% by mass or less of the content of the core-shell type elastomer. The resin composition according to one.
<5> The resin composition is molded into a flat plate test piece of 100 mm × 40 mm × 2 mm, and is measured with a sunshine weather meter at 83 ° C. (black panel temperature), no rain, and an optical filter: 60 in a test environment of # 255. The resin composition according to any one of <1> to <4>, wherein the color difference (ΔE *) of the test piece before and after the time test is 12 or less.
ΔE * = ((ΔL *) 2 + (Δa *) 2 + (Δb *) 2 ) 1/2
<6> The resin composition according to any one of <1> to <5>, wherein the resin composition is molded into a multipurpose test piece having a thickness of 4 mm, and the flexural modulus measured according to ISO178 is 1700 MPa or less. ..
<7> The ratio of the longitudinal elastic modulus of the shell portion of the core-shell type elastomer to the longitudinal elastic modulus of the polyacetal resin measured using the SPM (scanning probe microscope, cantilever spring constant: 9 N / m) (vertical elastic modulus of the shell portion). / The resin composition according to any one of <1> to <6>, wherein the polyacetal resin has a longitudinal elastic modulus of 0.08 or more.
<8> A molded product formed from the resin composition according to any one of <1> to <7>.
<9> The molded product according to <8>, which is an injection molded product.
<10> The method for producing a resin composition according to any one of <1> to <7>, in which a polyacetal resin and a core-shell type elastomer are mixed with a tumbler and then extruded with an extruder to obtain a strand shape. L / D, which is the ratio of the screw length L (mm) of the extruder to the screw diameter D (mm), includes 20 <(L / D) <100. A method for producing a resin composition, wherein the die nozzle for satisfying the above relationship and forming the strand shape has a diameter of 1 to 10 mm.
　本発明により、ウエルド部の密着性に優れ、かつ、耐候性に優れた樹脂組成物および成形品を提供可能になった。 INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a resin composition and a molded product having excellent adhesion of a weld portion and excellent weather resistance.
　以下において、本発明の内容について詳細に説明する。なお、本明細書において「～」とはその前後に記載される数値を下限値および上限値として含む意味で使用される。 The contents of the present invention will be described in detail below. In addition, in this specification, "-" is used in the meaning that the numerical values described before and after it are included as the lower limit value and the upper limit value.
　本発明の樹脂組成物は、ポリアセタール樹脂と、コアシェル型エラストマーを含む樹脂組成物であって、前記樹脂組成物を、ウエルド部を中央に有する１．６ｍｍ厚さの試験片に成形し、ＡＳＴＭ　Ｄ６３８に従い１０ｍｍ／分で引張った時のウエルド伸びが２０％以上であり、前記コアシェル型エラストマーが、ブタジエン含有ゴムを含み、シェル部にアクリル樹脂を含むことを特徴とする。
　上述のとおり、ポリアセタール樹脂について、様々な用途が期待されるが、その１つとして、耐候性が求められる用途も想定された。
　そして、本発明では、特定のコアシェル型エラストマーを用いることにより、耐候性のある樹脂組成物が得られた。
　また、本発明では、熱可塑性ポリウレタンに代えて、コアシェル型エラストマーを用い、さらに、ウエルド部付近において、粒子が小さいコアシェル型エラストマーを分散して存在するように調整することにより、ウエルド伸びを大きくすることができ、ウエルド部の密着性を向上させることに成功したものである。
　以下、本発明の詳細について説明する。 The resin composition of the present invention is a resin composition containing a polyacetal resin and a core-shell type elastomer, and the resin composition is molded into a 1.6 mm thick test piece having a weld portion in the center, and ASTM D638. According to the above, the weld elongation when pulled at 10 mm / min is 20% or more, the core-shell type elastomer contains a butadiene-containing rubber, and the shell portion contains an acrylic resin.
As described above, polyacetal resins are expected to have various uses, and one of them is expected to have weather resistance.
Then, in the present invention, a weather-resistant resin composition was obtained by using a specific core-shell type elastomer.
Further, in the present invention, a core-shell type elastomer is used instead of the thermoplastic polyurethane, and further, the core-shell type elastomer having small particles is adjusted so as to be dispersed and present in the vicinity of the weld portion, thereby increasing the weld elongation. This has succeeded in improving the adhesion of the weld portion.
The details of the present invention will be described below.
＜ポリアセタール樹脂＞
　本発明の樹脂組成物は、ポリアセタール樹脂を含む。
　ポリアセタール樹脂は特に限定されるものではなく、２価のオキシメチレン基のみを構成単位として含むホモポリマーであっても、２価のオキシメチレン基と、炭素数が２～６の２価のオキシアルキレン基とを構成単位として含むコポリマーであってもよい。 <Polyacetal resin>
The resin composition of the present invention contains a polyacetal resin.
The polyacetal resin is not particularly limited, and even if it is a homopolymer containing only a divalent oxymethylene group as a constituent unit, it has a divalent oxymethylene group and a divalent oxyalkylene having 2 to 6 carbon atoms. It may be a copolymer containing a group as a constituent unit.
　炭素数が２～６のオキシアルキレン基としては、オキシエチレン基、オキシプロピレン基、および、オキシブチレン基などが挙げられる。 Examples of the oxyalkylene group having 2 to 6 carbon atoms include an oxyethylene group, an oxypropylene group, and an oxybutylene group.
　ポリアセタール樹脂においては、オキシメチレン基および炭素数２～６のオキシアルキレン基の総モル数に占める炭素数２～６のオキシアルキレン基の割合は特に限定されるものではなく、０．５～１０モル％であればよい。 In the polyacetal resin, the ratio of the oxyalkylene group having 2 to 6 carbon atoms to the total number of moles of the oxymethylene group and the oxyalkylene group having 2 to 6 carbon atoms is not particularly limited, and is 0.5 to 10 mol. It may be%.
　上記ポリアセタール樹脂を製造するためには通常、主原料としてトリオキサンが用いられる。また、ポリアセタール樹脂中に炭素数２～６のオキシアルキレン基を導入するには、環状ホルマールや環状エーテルを用いることができる。環状ホルマールの具体例としては、１，３－ジオキソラン、１，３－ジオキサン、１，３－ジオキセパン、１，３－ジオキソカン、１，３，５－トリオキセパン、１，３，６－トリオキソカンなどが挙げられ、環状エーテルの具体例としては、エチレンオキシド、プロピレンオキシドおよびブチレンオキシドなどが挙げられる。ポリアセタール樹脂中にオキシエチレン基を導入するには、主原料として、１，３－ジオキソランを用いればよく、オキシプロピレン基を導入するには、主原料として、１，３－ジオキサンを用いればよく、オキシブチレン基を導入するには、主原料として、１，３－ジオキセパンを用いればよい。なお、ポリアセタール樹脂においては、ヘミホルマール末端基量、ホルミル末端基量、熱や酸、塩基に対して不安定な末端基量が少ない方がよい。ここで、ヘミホルマール末端基とは、－ＯＣＨ２ＯＨで表されるものであり、ホルミル末端基とは－ＣＨＯで表されるものである。 In order to produce the polyacetal resin, trioxane is usually used as a main raw material. Further, in order to introduce an oxyalkylene group having 2 to 6 carbon atoms into the polyacetal resin, cyclic formal or cyclic ether can be used. Specific examples of cyclic formal include 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepan, 1,3-dioxocan, 1,3,5-trioxepan, 1,3,6-trioxocan and the like. Specific examples of the cyclic ether include ethylene oxide, propylene oxide and butylene oxide. To introduce an oxyethylene group into a polyacetal resin, 1,3-dioxolane may be used as a main raw material, and to introduce an oxypropylene group, 1,3-dioxane may be used as a main raw material. To introduce an oxybutylene group, 1,3-dioxepan may be used as the main raw material. In the polyacetal resin, it is preferable that the amount of hemiformal terminal groups, the amount of formyl terminal groups, and the amount of terminal groups unstable to heat, acid, and base are small. Here, the hemiformal terminal group is represented by -OCH 2 OH, and the formyl terminal group is represented by -CHO.
　ポリアセタール樹脂としては、上記の他、特開２０１５－０７４７２４号公報の段落００１８～００４３に記載のポリアセタール樹脂を用いることができ、これらの内容は本明細書に組み込まれる。 As the polyacetal resin, in addition to the above, the polyacetal resins described in paragraphs 0018 to 0043 of JP2015-07724A can be used, and these contents are incorporated in the present specification.
　本発明の樹脂組成物は、ポリアセタール樹脂を６０質量％以上含むことが好ましく、６５質量％以上含むことがより好ましく、７０質量％以上含むことがさらに好ましく、７５質量％以上含むことが一層好ましく、７８質量％以上含むことがより一層好ましい。上限は、９５質量％以下であることが好ましく、９０質量％以下であることがより好ましく、８５質量％以下であることがさらに好ましい。このような範囲とすることにより、本発明の効果がより効果的に発揮される傾向にある。
　本発明の樹脂組成物は、ポリアセタール樹脂を１種のみ含んでいてもよいし、２種以上含んでいてもよい。２種以上含む場合、合計量が上記範囲となることが好ましい。 The resin composition of the present invention preferably contains a polyacetal resin in an amount of 60% by mass or more, more preferably 65% by mass or more, further preferably 70% by mass or more, and further preferably 75% by mass or more. It is even more preferable to contain 78% by mass or more. The upper limit is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. Within such a range, the effects of the present invention tend to be exhibited more effectively.
The resin composition of the present invention may contain only one type of polyacetal resin, or may contain two or more types of polyacetal resin. When two or more types are included, the total amount is preferably in the above range.
＜コアシェル型エラストマー＞
　本発明の樹脂組成物は、ブタジエン含有ゴムを含み、シェル部にアクリル樹脂を含むコアシェル型エラストマーを含む。本発明では、所定のコアシェル型エラストマーを用いることにより、耐候性に優れた樹脂組成物とすることができる。
　コアシェル型エラストマーとは、コア部とその一部または全部を被覆するシェル層を有する多層構造のポリマーであり、カネカ社のカネエースシリーズや三菱ケミカル社のメタブレンシリーズが知られている。本発明では、例えば、カネカ社製のカネエースＭ９１０シリーズを好ましく用いることができる。
　また、本発明では、コアシェル型エラストマーを用いることにより、ウエルド部付近でも粒子をつぶれにくくすることができる。さらに、ウエルド部付近に存在するコアシェル型エラストマーの平均二次粒子径が所定の範囲となるようにコアシェル型エラストマーの種類を選定することにより、ウエルド部付近において、コアシェル型エラストマーの小さい粒子を分散させることができる。さらに詳細を後述するとおり、溶融混練の際に諸条件を調整することによっても、コアシェル型エラストマーの二次平均粒子径が所定の範囲となるように調整できる。結果として、ウエルド伸びを高くすることができ、ウエルド密着性が向上する。
　本発明で用いるコアシェル型エラストマーの種類は特に問わないが、ブタジエン含有ゴムを含み、シェル部にアクリル樹脂を含むコアシェル型エラストマーが好ましい。このようなコアシェル型エラストマーを用いると、本発明の効果がより効果的に発揮される。 <Core-shell type elastomer>
The resin composition of the present invention contains a butadiene-containing rubber and a core-shell type elastomer containing an acrylic resin in the shell portion. In the present invention, a resin composition having excellent weather resistance can be obtained by using a predetermined core-shell type elastomer.
The core-shell type elastomer is a polymer having a multi-layer structure having a core portion and a shell layer covering a part or all of the core portion, and Kaneka Corporation's Kaneace series and Mitsubishi Chemical Corporation's Metabrene series are known. In the present invention, for example, the Kaneka M910 series manufactured by Kaneka Corporation can be preferably used.
Further, in the present invention, by using the core-shell type elastomer, it is possible to prevent the particles from being crushed even in the vicinity of the weld portion. Further, by selecting the type of core-shell elastomer so that the average secondary particle diameter of the core-shell elastomer existing in the vicinity of the weld portion is within a predetermined range, small particles of the core-shell elastomer are dispersed in the vicinity of the weld portion. be able to. As will be described in more detail later, the secondary average particle size of the core-shell elastomer can be adjusted to be within a predetermined range by adjusting various conditions during melt-kneading. As a result, the weld elongation can be increased and the weld adhesion is improved.
The type of core-shell elastomer used in the present invention is not particularly limited, but a core-shell elastomer containing butadiene-containing rubber and an acrylic resin in the shell portion is preferable. When such a core-shell type elastomer is used, the effect of the present invention is exhibited more effectively.
　本発明で用いるコアシェル型エラストマーは、ＳＰＭ（走査型プローブ顕微鏡、カンチレバーばね定数：９Ｎ／ｍ）を用いて測定したコアシェル型エラストマーのシェル部の縦弾性率とポリアセタール樹脂の縦弾性率の比率（シェル部の縦弾性率／ポリアセタール樹脂の縦弾性率）が０．０８以上であることが好ましく、０．１０以上であることがより好ましく、０．１５以上であることがさらに好ましく、０．２以上であることが一層好ましい。前記下限値以上とすることにより、成形時にウエルド部に発生する圧力によるコアシェル型エラストマーの変形をより効果的に抑制できる。また、前記シェル部の縦弾性率／ポリアセタール樹脂の縦弾性率の上限値は、特に、定めるものではないが、１．０以下が実際的である。
　縦弾性率は、後述する実施例の記載に従って測定される。 The core-shell elastomer used in the present invention is the ratio of the longitudinal elastic modulus of the shell portion of the core-shell elastomer to the longitudinal elastic modulus of the polyacetal resin (shell) measured using an SPM (scanning probe microscope, cantilever spring constant: 9 N / m). The longitudinal elastic modulus of the portion / the longitudinal elastic modulus of the polyacetal resin) is preferably 0.08 or more, more preferably 0.10 or more, further preferably 0.15 or more, and 0.2 or more. Is more preferable. By setting the value to the lower limit or more, the deformation of the core-shell type elastomer due to the pressure generated in the weld portion during molding can be more effectively suppressed. Further, the upper limit value of the longitudinal elastic modulus of the shell portion / the longitudinal elastic modulus of the polyacetal resin is not particularly determined, but is practically 1.0 or less.
The longitudinal elastic modulus is measured according to the description of Examples described later.
　本発明の樹脂組成物は、コアシェル型エラストマーを５質量％以上含むことが好ましく、１０質量％以上含むことがより好ましく、１５質量％以上含むことがさらに好ましい。上限は、４０質量％以下であることが好ましく、３５質量％以下であることがより好ましく、３０質量％以下であることがさらに好ましく、２５質量％以下であることが一層好ましく、２２質量％以下であることがより一層好ましい。このような範囲とすることにより、本発明の効果がより効果的に発揮される傾向にある。
　本発明の樹脂組成物は、コアシェル型エラストマーを１種のみ含んでいてもよいし、２種以上含んでいてもよい。２種以上含む場合、合計量が上記範囲となることが好ましい。
　本発明の樹脂組成物は、ポリアセタール樹脂６０～９５質量％（好ましくは７０～９５質量％）と、前記コアシェル型エラストマー４０～５質量％（好ましくは３０～５質量％）を含む（ただし、ポリアセタール樹脂とコアシェル型エラストマーの合計が１００質量％を超えることはない）ことが好ましい。
　本発明の樹脂組成物は、ポリアセタール樹脂とコアシェル型エラストマーの合計量が樹脂組成物の９５質量％以上を占めることが好ましく、９８質量％以上を占めることがより好ましい。 The resin composition of the present invention preferably contains a core-shell type elastomer in an amount of 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more. The upper limit is preferably 40% by mass or less, more preferably 35% by mass or less, further preferably 30% by mass or less, further preferably 25% by mass or less, and 22% by mass or less. Is even more preferable. Within such a range, the effects of the present invention tend to be exhibited more effectively.
The resin composition of the present invention may contain only one type of core-shell type elastomer, or may contain two or more types. When two or more types are included, the total amount is preferably in the above range.
The resin composition of the present invention contains 60 to 95% by mass (preferably 70 to 95% by mass) of the polyacetal resin and 40 to 5% by mass (preferably 30 to 5% by mass) of the core-shell elastomer (however, polyacetal). The total of the resin and the core-shell type elastomer does not exceed 100% by mass).
In the resin composition of the present invention, the total amount of the polyacetal resin and the core-shell type elastomer preferably occupies 95% by mass or more, and more preferably 98% by mass or more of the resin composition.
＜他の成分＞
　本発明の樹脂組成物は、本発明の目的を損なわない範囲内で、従来公知の任意の添加剤や充填剤を含んでいてもよい。本発明に用いる添加剤や充填剤としては、例えば、ポリアセタール樹脂以外の熱可塑性樹脂、紫外線吸収剤、酸化防止剤、安定剤、ホルムアルデヒド捕捉剤、帯電防止剤、炭素繊維、ガラス繊維、ガラスフレーク、チタン酸カリウムウイスカー等が挙げられる。これらの詳細は、特開２０１７－０２５２５７号公報の段落０１１３～０１２４の記載を参酌することができ、これらの内容は本明細書に組み込まれる。 <Other ingredients>
The resin composition of the present invention may contain any conventionally known additives and fillers as long as the object of the present invention is not impaired. Examples of the additives and fillers used in the present invention include thermoplastic resins other than polyacetal resins, ultraviolet absorbers, antioxidants, stabilizers, formaldehyde traps, antistatic agents, carbon fibers, glass fibers, and glass flakes. Examples include potassium titanate whiskers. These details can be referred to in paragraphs 0113 to 0124 of JP-A-2017-0252557, and these contents are incorporated in the present specification.
　本発明の樹脂組成物は、また、熱可塑性ポリウレタンを含まないか、熱可塑性ポリウレタンの含有量が、コアシェル型エラストマーの含有量の３質量％以下（好ましくは１質量％以下、さらに好ましくは０．１質量％以下）であることが好ましい。このような構成とすることにより、ウエルド密着性をより向上させることができる。 The resin composition of the present invention also does not contain thermoplastic polyurethane, or the content of the thermoplastic polyurethane is 3% by mass or less (preferably 1% by mass or less, more preferably 0.% by mass) of the content of the core-shell type elastomer. 1% by mass or less) is preferable. With such a configuration, the weld adhesion can be further improved.
＜樹脂組成物の物性＞
　本発明の樹脂組成物は、４ｍｍ厚さの多目的試験片に成形し、ＩＳＯ１７８に従って測定した曲げ弾性率が１７００ＭＰａ以下であることが好ましく、１６５０ＭＰａ以下であることがより好ましく、１６００ＭＰａ以下であることがさらに好ましい。下限値は、特に定めるものではないが、例えば、１０００ＭＰａ以上、さらには、１１００ＭＰａ以上、１３００ＭＰａ以上、１４００ＭＰａ以上、１５００ＭＰａ以上が実際的である。本発明では軟質性を改善しつつも、耐候性に優れたものとできる点で価値が高い。
　また、本発明の樹脂組成物は、ウエルド部を中央に有する１．６ｍｍ厚さの試験片に成形し、ＡＳＴＭ　Ｄ６３８に従い１０ｍｍ／分で引張った時のウエルド伸びが２０％以上であり、２５％以上であることが好ましく、３０％以上であることがより好ましく、３５％以上であることがさらに好ましい。前記ウエルド伸びの上限値は特に定めるものではないが、例えば、９９％以下、さらには、９０％以下、８０％以下が実際的である。
　さらに、本発明の樹脂組成物は、ウエルド部を中央に有する３．２ｍｍ厚さの試験片に成形したときの、ウエルド部に存在する前記コアシェル型エラストマーの平均二次粒子径が５０ｎｍ以上であることが実際的である。また、前記平均二次粒子径が５００ｎｍ以下であることが好ましく、３００ｎｍ以下であることがより好ましく、２００ｎｍ以下であることがさらに好ましく、１５０ｎｍ以下であることが一層好ましく、１２０ｎｍ以下であることがより一層好ましく、１１０ｎｍ以下、さらには、１００ｎｍ以下であってもよい。
　さらに、前記樹脂組成物を、１００ｍｍ×４０ｍｍ×２ｍｍの平板試験片に成形し、サンシャインウェザーメーターにて、８３℃（ブラックパネル温度）、雨なし、光フィルター：＃２５５の試験環境で、６０時間試験した前後の試験片の色差（ΔＥ＊）が１２以下であることが好ましく、１１以下であることがより好ましく、１０以下であることがさらに好ましく、９以下であることが一層好ましい。下限値は、１以上が実際的である。
ΔＥ＊＝（（ΔＬ＊）２＋（Δａ＊）２＋（Δｂ＊）２）１／２ <Physical characteristics of resin composition>
The resin composition of the present invention is molded into a multipurpose test piece having a thickness of 4 mm, and the flexural modulus measured according to ISO178 is preferably 1700 MPa or less, more preferably 1650 MPa or less, and more preferably 1600 MPa or less. More preferred. The lower limit value is not particularly specified, but is practically, for example, 1000 MPa or more, further 1100 MPa or more, 1300 MPa or more, 1400 MPa or more, and 1500 MPa or more. The present invention has high value in that it can be made excellent in weather resistance while improving the softness.
Further, the resin composition of the present invention has a weld elongation of 20% or more when molded into a 1.6 mm thick test piece having a weld portion in the center and pulled at 10 mm / min according to ASTM D638, which is 25%. The above is preferable, 30% or more is more preferable, and 35% or more is further preferable. The upper limit of the weld elongation is not particularly defined, but for example, 99% or less, further 90% or less, and 80% or less are practical.
Further, the resin composition of the present invention has an average secondary particle diameter of 50 nm or more of the core-shell elastomer present in the weld portion when molded into a 3.2 mm thick test piece having a weld portion in the center. Is practical. Further, the average secondary particle diameter is preferably 500 nm or less, more preferably 300 nm or less, further preferably 200 nm or less, further preferably 150 nm or less, and further preferably 120 nm or less. Even more preferably, it may be 110 nm or less, and even 100 nm or less.
Further, the resin composition is molded into a flat plate test piece of 100 mm × 40 mm × 2 mm, and is measured with a sunshine weather meter at 83 ° C. (black panel temperature), no rain, and an optical filter: # 255 for 60 hours. The color difference (ΔE *) of the test pieces before and after the test is preferably 12 or less, more preferably 11 or less, further preferably 10 or less, and even more preferably 9 or less. The lower limit is practically 1 or more.
ΔE * = ((ΔL *) 2 + (Δa *) 2 + (Δb *) 2 ) 1/2
＜ポリアセタール樹脂組成物の製造方法＞
　本発明のポリアセタール樹脂組成物は、上述した必須成分および必要に応じ上述した任意の成分を含有させてなる。そしてその製造方法は任意であり、従来公知の任意の、樹脂組成物の製造方法を使用し、これらの原料を混合・混練すればよい。 <Manufacturing method of polyacetal resin composition>
The polyacetal resin composition of the present invention contains the above-mentioned essential components and, if necessary, any of the above-mentioned optional components. The production method thereof is arbitrary, and any conventionally known method for producing a resin composition may be used to mix and knead these raw materials.
　混練機は、ニーダー、バンバリーミキサー、押出機等が例示される。混合・混練の各種条件や装置についても、特に制限はなく、従来公知の任意の条件から適宜選択して決定すればよい。混練はポリアセタール樹脂が溶融する温度以上、具体的にはポリアセタール樹脂の融解温度以上で行うことが好ましい。 Examples of the kneading machine include a kneader, a Banbury mixer, and an extruder. The various conditions and devices for mixing and kneading are also not particularly limited, and may be appropriately selected and determined from any conventionally known conditions. The kneading is preferably performed at a temperature equal to or higher than the melting temperature of the polyacetal resin, specifically, a temperature higher than the melting temperature of the polyacetal resin.
　特に、本発明のポリアセタール樹脂組成物において、コアシェル型エラストマーの二次凝集を抑制し、平均二次粒子径を適切な値に調整するためには、以下の方法を好ましく用いることができる。 In particular, in the polyacetal resin composition of the present invention, the following methods can be preferably used in order to suppress the secondary aggregation of the core-shell type elastomer and adjust the average secondary particle size to an appropriate value.
　ポリアセタール樹脂組成物中におけるコアシェル型エラストマーの二次凝集の抑制するための好ましい製造方法の一例としてポリアセタール樹脂とコアシェル型エラストマーをタンブラーで混合した後、押出機にて押出し、ストランド状とした後に切断してペレットとする方法が挙げられる。この際、押出機としては単軸押出機では二次凝集が発生しやすいことから、二軸押出機を用いることが好ましい。中でもスクリューの長さＬ（ｍｍ）と同スクリューの直径Ｄ（ｍｍ）の比であるＬ／Ｄが、２０＜（Ｌ／Ｄ）＜１００の関係を満足することが好ましく、２５＜（Ｌ／Ｄ）＜７０を満足することがより好ましい。かかる比を２０超とすることにより、コアシェル型エラストマーが微分散しやすくなり、二次凝集の発生をより効果的に抑制できる。また、前記比を１００未満とすることにより、熱劣化により樹脂組成物が変色しやすくなるのを効果的に抑制できる。
　ダイノズルの形状も特に限定されないが、ペレット形状の点で、直径１～１０ｍｍの円形ノズルが好ましく、直径２～７ｍｍの円形ノズルがより好ましい。ここでの円形とは、幾何学的な意味での円形に限定解釈されるものではなく、本実施形態の技術分野においてほぼ円形と解釈されるものを含む趣旨である。 As an example of a preferable production method for suppressing secondary aggregation of the core-shell type elastomer in the polyacetal resin composition, the polyacetal resin and the core-shell type elastomer are mixed with a tumbler, extruded by an extruder, formed into a strand, and then cut. There is a method of making pellets. At this time, as the extruder, it is preferable to use a twin-screw extruder because secondary agglutination is likely to occur in a single-screw extruder. Above all, it is preferable that L / D, which is the ratio of the screw length L (mm) to the diameter D (mm) of the screw, satisfies the relationship of 20 <(L / D) <100, and 25 <(L / L /). D) It is more preferable to satisfy <70. By setting such a ratio to more than 20, the core-shell type elastomer can be easily finely dispersed, and the occurrence of secondary aggregation can be suppressed more effectively. Further, by setting the ratio to less than 100, it is possible to effectively suppress the resin composition from being easily discolored due to thermal deterioration.
The shape of the die nozzle is not particularly limited, but in terms of pellet shape, a circular nozzle having a diameter of 1 to 10 mm is preferable, and a circular nozzle having a diameter of 2 to 7 mm is more preferable. The term "circle" as used herein is not limited to a circle in a geometrical sense, but includes a circle that is interpreted as a substantially circle in the technical field of the present embodiment.
　また、溶融混練時の樹脂組成物の溶融温度は、樹脂の融解温度との関係で適宜定められるが、１７０℃以上であることが好ましく、１８０℃以上であることがより好ましく、１９０℃以上であることがさらに好ましい。また、前記溶融温度は、２５０℃以下であることが好ましく、２３０℃以下であることがより好ましい。溶融温度を１７０℃以上とすることにより、溶融が十分になされ、生産量が顕著に向上する傾向にある。また、２５０℃以下とすることにより、熱劣化による樹脂組成物の変色をより効果的に抑制できる。 The melting temperature of the resin composition at the time of melt-kneading is appropriately determined in relation to the melting temperature of the resin, but is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, and 190 ° C. or higher. It is more preferable to have. Further, the melting temperature is preferably 250 ° C. or lower, more preferably 230 ° C. or lower. By setting the melting temperature to 170 ° C. or higher, melting is sufficiently performed, and the production amount tends to be remarkably improved. Further, by setting the temperature to 250 ° C. or lower, discoloration of the resin composition due to thermal deterioration can be more effectively suppressed.
　溶融混練時のスクリュー回転数は５０～５００ｒｐｍであることが好ましく、７０～３５０ｒｐｍであることがより好ましい。スクリュー回転数を５０ｒｐｍ以上とすることにより、コアシェル型エラストマーが微分散しやすくなり、二次凝集の発生をより効果的に抑制できる。また、５００ｒｐｍ以下とすることにより、溶融混練時の発熱を顕著に抑制でき、熱劣化による樹脂組成物の変色を効果的に抑制できる。また吐出量は５～１，０００ｋｇ／ｈｒであることが好ましく、７～８００ｋｇ／ｈｒでああることがより好ましい。５ｋｇ／ｈｒ以上とすることにより、コアシェル型エラストマーが微分散しやすくなり、二次凝集の発生を効果的に抑制できる。また、１，０００ｋｇ／ｈｒ以下とすることにより、溶融混練時の発熱を効果的に抑制でき、熱劣化による樹脂組成物の変色をより効果的に抑制できる。 The screw rotation speed during melt-kneading is preferably 50 to 500 rpm, more preferably 70 to 350 rpm. By setting the screw rotation speed to 50 rpm or more, the core-shell type elastomer can be easily finely dispersed, and the occurrence of secondary aggregation can be suppressed more effectively. Further, by setting the speed to 500 rpm or less, heat generation during melt-kneading can be remarkably suppressed, and discoloration of the resin composition due to thermal deterioration can be effectively suppressed. The discharge amount is preferably 5 to 1,000 kg / hr, and more preferably 7 to 800 kg / hr. By setting the content to 5 kg / hr or more, the core-shell type elastomer can be easily finely dispersed, and the occurrence of secondary aggregation can be effectively suppressed. Further, by setting the weight to 1,000 kg / hr or less, heat generation during melt-kneading can be effectively suppressed, and discoloration of the resin composition due to thermal deterioration can be more effectively suppressed.
＜成形品＞
　本発明の成形品は、本発明のポリアセタール樹脂組成物から形成される。また、本発明のポリアセタール樹脂組成物をペレタイズして得られたペレットは、通常、射出成形して成形品とされる。本発明におけるペレットは、円柱状であることが好ましく、その直径は１～１０ｍｍであることが好ましく、２～７ｍｍであることがより好ましい。ここでの円柱状とは、幾何学的な意味での円柱状のものに加え、本発明の技術分野において、円柱状と解釈されるものを含む趣旨である。例えば、吐出口が円形であるノズルから吐出したストランドをカットして得られた形状は、円柱状のものに含まれる。
　すなわち、本発明の成形品の好ましい一例は、射出成形品である。射出成形品とは、射出成形により、成形された成形品であり、通常、金型内で溶融樹脂が合流する部分に脆弱部分（ウエルド部）が形成されてしまう。
　本発明の成形品の厚さは、例えば、０．００５～２０ｍｍの部位を有することが好ましく、用途に応じて適当な厚みを選択できる。
　成形品の形状としては、特に制限はなく、成形品の用途、目的に応じて適宜選択することができ、例えば、板状、プレート状、ロッド状、シート状、フィルム状、円筒状、環状、円形状、楕円形状、歯車状、多角形形状、異形品、中空品、枠状、箱状、パネル状、キャップ状のもの等が挙げられる。本発明の成形品は、部品であっても、完成品であってもよい。 <Molded product>
The molded article of the present invention is formed from the polyacetal resin composition of the present invention. Further, the pellet obtained by pelletizing the polyacetal resin composition of the present invention is usually injection-molded to obtain a molded product. The pellet in the present invention is preferably cylindrical, preferably has a diameter of 1 to 10 mm, and more preferably 2 to 7 mm. The term "cylindrical" as used herein means that, in addition to the cylindrical one in the geometrical sense, the one interpreted as a cylindrical one in the technical field of the present invention is included. For example, a shape obtained by cutting a strand discharged from a nozzle having a circular discharge port is included in a columnar shape.
That is, a preferable example of the molded product of the present invention is an injection molded product. The injection-molded product is a molded product molded by injection molding, and usually, a fragile portion (weld portion) is formed in a portion where the molten resin joins in the mold.
The thickness of the molded product of the present invention preferably has, for example, a portion of 0.005 to 20 mm, and an appropriate thickness can be selected according to the application.
The shape of the molded product is not particularly limited and may be appropriately selected depending on the intended use and purpose of the molded product. For example, plate-shaped, plate-shaped, rod-shaped, sheet-shaped, film-shaped, cylindrical, annular, etc. Examples thereof include a circular shape, an elliptical shape, a gear shape, a polygonal shape, a deformed product, a hollow product, a frame shape, a box shape, a panel shape, and a cap shape. The molded product of the present invention may be a part or a finished product.
＜用途＞
　本発明のポリアセタール樹脂組成物およびポリアセタール樹脂組成物から形成される成形品は、耐候性が求められる用途に広く用いられる。具体的には、車両部品、建材部品、電気・電子部品、事務機器部品、日用雑貨部品などに用いられる。特に、紫外線の照射を受ける部分に用いられる。 <Use>
The polyacetal resin composition of the present invention and a molded product formed from the polyacetal resin composition are widely used in applications requiring weather resistance. Specifically, it is used for vehicle parts, building material parts, electrical / electronic parts, office equipment parts, daily miscellaneous goods parts, and the like. In particular, it is used for parts that are irradiated with ultraviolet rays.
　以下に実施例を挙げて本発明をさらに具体的に説明する。以下の実施例に示す材料、使用量、割合、処理内容、処理手順等は、本発明の趣旨を逸脱しない限り、適宜、変更することができる。従って、本発明の範囲は以下に示す具体例に限定されるものではない。 The present invention will be described in more detail with reference to examples below. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.
［原料］
ポリアセタール樹脂（ＰＯＭ）
ＰＯＭ１：Ｆ２０－０３、三菱エンジニアリングプラスチックス社製
ＰＯＭ２：Ｆ１０－０１、三菱エンジニアリングプラスチックス社製
エラストマー１：コアがブタジエン由来の構成単位を含み、シェルがアクリル樹脂を含むコアシェル型エラストマー、カネカ社製、カネエースＭ９１０
エラストマー２：コアがブタジエン由来の構成単位を含み、シェルがアクリル樹脂を含むコアシェル型エラストマー、カネカ社製、カネエースＭ９１０改良品
エラストマー３：コアがシリコーンゴム、シェルがアクリロニトリルスチレン樹脂を含むコアシェル型エラストマー、メタブレン、三菱ケミカル社製、ＳＸ－００６
エラストマー４：コアがシリコーンゴム、シェルがアクリロニトリルスチレン樹脂を含むコアシェル型エラストマー、メタブレン、三菱ケミカル社製、ＳＲＫ－２００
エラストマー５：熱可塑性ポリウレタン、ＢＡＳＦ社製、品番：エラストランＳ８０ＡＳＨ１０ [material]
Polyacetal resin (POM)
POM1: F20-03, Mitsubishi Engineering Plastics POM2: F10-01, Mitsubishi Engineering Plastics Elastomer 1: Core-shell type elastomer whose core contains butadiene-derived structural units and whose shell contains acrylic resin, manufactured by Kaneka Corporation. , Kaneka M910
Elastomer 2: Core-shell type elastomer in which the core contains a butadiene-derived structural unit and the shell contains an acrylic resin, Kaneka M910 improved elastomer 3: Core-shell type elastomer in which the core is silicone rubber and the shell is acrylonitrile styrene resin. Elastomer, manufactured by Mitsubishi Chemical, SX-006
Elastomer 4: Core-shell type elastomer containing silicone rubber for the core and acrylonitrile styrene resin for the shell, Metabrene, manufactured by Mitsubishi Chemical Corporation, SRK-200
Elastomer 5: Thermoplastic polyurethane, manufactured by BASF, product number: Elastolan S80ASH10
［実施例１～８、比較例１～５、参考例１］
　表１～３に示す各成分を表１～３に示す割合（質量部）で、川田製作所社製スーパーミキサーを用いて均一に混合した。得られた混合物をスクリュー径（Ｄ）３０ｍｍ、スクリュー長さ（Ｌ）７６０ｍｍ、ダイノズル径３．５ｍｍのベント付き二軸押出機（株式会社池貝製「ＰＣＭ－３０」）を用いて、シリンダー温度（溶融温度）２００℃、スクリュー回転数１２０ｒｐｍ、吐出量１０ｋｇ／時間で溶融せん断混合し、ポリアセタール樹脂組成物のペレットを製造した。
　比較例６は、三菱エンジニアリングプラスチックス社製、ＵＲ２０Ｈを用いた。 [Examples 1 to 8, Comparative Examples 1 to 5, Reference Example 1]
Each component shown in Tables 1 to 3 was uniformly mixed using a super mixer manufactured by Kawada Seisakusho Co., Ltd. at the ratio (parts by mass) shown in Tables 1 to 3. The obtained mixture was subjected to cylinder temperature (“PCM-30” manufactured by Ikegai Corp.) with a vented twin-screw extruder (“PCM-30” manufactured by Ikegai Corp.) having a screw diameter (D) of 30 mm, a screw length (L) of 760 mm, and a die nozzle diameter of 3.5 mm. Pellets of a polyacetal resin composition were produced by melt-shear mixing at a melting temperature of 200 ° C., a screw rotation speed of 120 rpm, and a discharge rate of 10 kg / hour.
In Comparative Example 6, UR20H manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.
＜曲げ弾性率＞
　上記で得られたペレットを、温度８０℃の熱風循環式乾燥機にて４時間熱処理を行った。
　次に、上記乾燥後のペレットを、射出成形機を用い、シリンダー温度１９５℃に設定し、金型温度を９０℃に設定して、ＩＳＯ９９８８－２規格に準拠して、射出成形した。こうして、４ｍｍ厚さの多目的試験片（ＩＳＯ試験片）を得た。
　次に、この４ｍｍ厚さの多目的試験片（ＩＳＯ試験片）について、曲げ試験機である全自動曲げ試験機を用いて、ＩＳＯ１７８に記載の方法に従って、曲げ試験速度２ｍｍ／分で曲げ試験を行い、曲げ弾性率を測定した。
　射出成形機は、東芝機械社製、ＥＣ－１００Ｓを用いた。全自動曲げ試験機は、島津製作所社製のものを用いた。
　結果を下記表１～３に示した。単位は、ＭＰａで示した。 <Flexural modulus>
The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C.
Next, the dried pellets were injection-molded in accordance with the ISO9998-2 standard by setting the cylinder temperature to 195 ° C. and the mold temperature to 90 ° C. using an injection molding machine. In this way, a multipurpose test piece (ISO test piece) having a thickness of 4 mm was obtained.
Next, the 4 mm-thick multipurpose test piece (ISO test piece) is subjected to a bending test at a bending test speed of 2 mm / min according to the method described in ISO178 using a fully automatic bending tester which is a bending tester. , The flexural modulus was measured.
As an injection molding machine, EC-100S manufactured by Toshiba Machine Co., Ltd. was used. A fully automatic bending tester manufactured by Shimadzu Corporation was used.
The results are shown in Tables 1 to 3 below. The unit is shown in MPa.
＜ウエルド伸び＞
　上記で得られたペレットを、温度８０℃の熱風循環式乾燥機にて４時間熱処理を行った。
　次に、上記乾燥後のペレットを、射出成形機を用い、シリンダー温度１９５℃に設定し、金型温度を９０℃に設定して、ウエルド部を中央に有するＡＳＴＭ引張試験片（厚み１．６ｍｍ）を作製し、ＡＳＴＭ　Ｄ６３８に準じて、引張試験を行って、ウエルド伸びを測定した。
　射出成形機は、東芝機械社製、ＥＣ－１００Ｓを用いた。
　結果を下記表１～３に示した。単位は、％で示した。 <Weld growth>
The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C.
Next, the dried pellets were set to a cylinder temperature of 195 ° C. and a mold temperature of 90 ° C. using an injection molding machine, and an ASTM tensile test piece (thickness 1.6 mm) having a weld portion in the center. ) Was prepared, and a tensile test was performed according to ASTM D638 to measure the weld elongation.
As an injection molding machine, EC-100S manufactured by Toshiba Machine Co., Ltd. was used.
The results are shown in Tables 1 to 3 below. The unit is shown in%.
＜耐候性＞
　上記で得られたペレットを、温度８０℃の熱風循環式乾燥機にて４時間熱処理を行った。次に、射出成形機を用い、シリンダー温度２１５℃、金型温度８０℃に設定し、１００ｍｍ×４０ｍｍ×２ｍｍの平板試験片を作製した。得られた平板試験片を使用して、サンシャインウェザーメーターにて、８３℃（ブラックパネル温度）、雨なし、光フィルター：＃２５５の試験環境で、６０時間試験した前と、６０時間後の試験片の色差（ΔＥ＊）を下記の方法にて測定した。
　分光測色色差計を使用し、耐候性試験前と、６０時間耐光性試験後の色差（ΔＥ＊）を次式で評価した。
ΔＥ＊＝（（ΔＬ＊）２＋（Δａ＊）２＋（Δｂ＊）２）１／２
ΔＥ＊が小さいほど変色性が小さく、耐候性に優れているといえる。
　尚、射出成形機は、日精樹脂工業社製、ＰＳ－４０を用いた。サンシャインウェザーメーターは、スガ試験機社製、サンシャインウェザーメーターＳ８０を用いた。分光測色色差計は、日本電色工業社製、ＳＥ２０００を用いた。
　結果を下記表１～３に示した。 <Weather resistance>
The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C. Next, using an injection molding machine, the cylinder temperature was set to 215 ° C. and the mold temperature was set to 80 ° C. to prepare a flat plate test piece of 100 mm × 40 mm × 2 mm. Using the obtained flat plate test piece, test before and after 60 hours in a test environment of 83 ° C (black panel temperature), no rain, optical filter: # 255 with a sunshine weather meter. The color difference (ΔE *) of one piece was measured by the following method.
Using a spectrophotometric color difference meter, the color difference (ΔE *) before the weather resistance test and after the 60-hour light resistance test was evaluated by the following equation.
ΔE * = ((ΔL *) 2 + (Δa *) 2 + (Δb *) 2 ) 1/2
It can be said that the smaller ΔE * is, the smaller the discoloration property is and the better the weather resistance is.
As the injection molding machine, PS-40 manufactured by Nissei Resin Industry Co., Ltd. was used. As the sunshine weather meter, a sunshine weather meter S80 manufactured by Suga Test Instruments Co., Ltd. was used. As the spectrophotometric color difference meter, SE2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. was used.
The results are shown in Tables 1 to 3 below.
＜エラストマーの平均二次粒子径＞
　上記で得られたペレットを、温度８０℃の熱風循環式乾燥機にて４時間熱処理を行った。
　次に、上記乾燥後のペレットを、射出成形機を用い、シリンダー温度１９５℃に設定し、金型温度を９０℃に設定して、ウエルド部を中央に有するＡＳＴＭ引張試験片（厚み３．２ｍｍ）を作製した。
　このＡＳＴＭ引張試験片から、成形時の流動方向に平行で、かつ、ウエルド部を含むようにダイヤモンドナイフで走査型電子顕微鏡（ＳＥＭ）観察用試験片を切り出した。
　得られたＳＥＭ観察用試験片の観察面に四酸化オスミウムを蒸着させた後、走査型電子顕微鏡（ＳＥＭ）を用いてＳＥＭ画像を取得した。
　得られたＳＥＭ画像から、エラストマー由来の島状部の最大長さの平均値を、エラストマーの平均二次粒子径とした。
　射出成形機は、東芝機械社製、ＥＣ－１００Ｓを用いた。
　四酸化オスミウムの蒸着は、メイワフォーシス社製「オスミウムコータ」を用いて８ｍＡ、６０秒の条件で行った。走査型電子顕微鏡は、日立ハイテクノロジーズ製「走査型電子顕微鏡（ＳＥＭ）Ｓ－４８００」を用い、加速電圧：１ｋＶ、信号：ＬＡ１００（Ｕ）、エミッション電流：６μＡ、プローブ電流：Ｎｏｒｍａｌの条件でＳＥＭ画像を取得した。
　結果を下記表１～３に示した。単位はμｍで示した。 <Average secondary particle size of elastomer>
The pellets obtained above were heat-treated for 4 hours in a hot air circulation dryer at a temperature of 80 ° C.
Next, the dried pellets were set to a cylinder temperature of 195 ° C. and a mold temperature of 90 ° C. using an injection molding machine, and an ASTM tensile test piece (thickness 3.2 mm) having a weld portion in the center. ) Was prepared.
From this ASTM tensile test piece, a test piece for scanning electron microscope (SEM) observation was cut out with a diamond knife so as to be parallel to the flow direction at the time of molding and include a weld portion.
After depositing osmium tetroxide on the observation surface of the obtained SEM observation test piece, an SEM image was acquired using a scanning electron microscope (SEM).
From the obtained SEM image, the average value of the maximum lengths of the island-shaped portions derived from the elastomer was taken as the average secondary particle diameter of the elastomer.
As an injection molding machine, EC-100S manufactured by Toshiba Machine Co., Ltd. was used.
The vapor deposition of osmium tetroxide was carried out using a "osmium coater" manufactured by Meiwaforsis Co., Ltd. under the conditions of 8 mA and 60 seconds. As the scanning electron microscope, "scanning electron microscope (SEM) S-4800" manufactured by Hitachi High-Technologies is used, and SEM under the conditions of acceleration voltage: 1 kV, signal: LA100 (U), emission current: 6 μA, probe current: Normal. I got an image.
The results are shown in Tables 1 to 3 below. The unit is shown in μm.
＜縦弾性率の測定＞
　平均二次粒子径の測定と同様手順で走査型プローブ顕微鏡（ＳＰＭ）観察用試験片を切り出し走査型プローブ顕微鏡（ＳＰＭ）のフォースカーブマッピング法にて縦弾性率像を得た。得られた縦弾性率像からポリアセタール樹脂部について合計１０か所の縦弾性率を測定した。次いで、縦弾性率像からコアシェル型エラストマーのシェル部について合計１０か所の縦弾性率を測定した。また、非コアシェル型エラストマーについてはポリアセタール樹脂との界面付近における縦弾性率を測定した。
　さらに、コアシェル型エラストマーのシェル部の縦弾性率と、ポリアセタール樹脂の縦弾性率から、縦弾性率比（シェル部の縦弾性率／ポリアセタール樹脂の縦弾性率）を算出した。
　走査型プローブ顕微鏡は島津製作所製「ＳＰＭ－９７００ＨＴ」を用い、スキャナ：３０μｍ×３０μｍ、カンチレバー：オリンパス製「ＡＣ２００（バネ定数９Ｎ／ｍ）」、スイープ速度：１Ｈｚ、スイープ範囲：１５００ｎｍ、Ｉゲイン：１００の条件で弾性率像を得た。 <Measurement of longitudinal elastic modulus>
A test piece for observation with a scanning probe microscope (SPM) was cut out in the same procedure as the measurement of the average secondary particle size, and a longitudinal elastic modulus image was obtained by a force curve mapping method of the scanning probe microscope (SPM). From the obtained longitudinal elastic modulus image, the longitudinal elastic modulus at a total of 10 points was measured for the polyacetal resin portion. Next, from the longitudinal elastic modulus image, the longitudinal elastic modulus was measured at a total of 10 locations for the shell portion of the core-shell type elastomer. For the non-core shell type elastomer, the longitudinal elastic modulus near the interface with the polyacetal resin was measured.
Further, the longitudinal elastic modulus ratio (the longitudinal elastic modulus of the shell portion / the longitudinal elastic modulus of the polyacetal resin) was calculated from the longitudinal elastic modulus of the shell portion of the core-shell type elastomer and the longitudinal elastic modulus of the polyacetal resin.
The scanning probe microscope uses "SPM-9700HT" manufactured by Shimadzu Corporation, scanner: 30 μm × 30 μm, cantilever: “AC200 (spring constant 9 N / m)” manufactured by Olympus, sweep speed: 1 Hz, sweep range: 1500 nm, I gain: An elastic modulus image was obtained under 100 conditions.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003

Claims (10)

  1. ポリアセタール樹脂と、コアシェル型エラストマーを含む樹脂組成物であって、前記樹脂組成物を、ウエルド部を中央に有する１．６ｍｍ厚さの試験片に成形し、ＡＳＴＭ　Ｄ６３８に従い１０ｍｍ／分で引張った時のウエルド伸びが２０％以上であり、前記コアシェル型エラストマーが、ブタジエン含有ゴムを含み、シェル部にアクリル樹脂を含む、樹脂組成物。 A resin composition containing a polyacetal resin and a core-shell type elastomer, when the resin composition is molded into a 1.6 mm-thick test piece having a weld portion in the center and pulled at 10 mm / min according to ASTM D638. A resin composition having a weld elongation of 20% or more, the core-shell type elastomer containing butadiene-containing rubber, and an acrylic resin in the shell portion.
  2. 前記樹脂組成物は、前記ポリアセタール樹脂６０～９５質量％と、前記コアシェル型エラストマー４０～５質量％を含む（ただし、ポリアセタール樹脂とコアシェル型エラストマーの合計が１００質量％を超えることはない）、請求項１に記載の樹脂組成物。 The resin composition comprises 60 to 95% by mass of the polyacetal resin and 40 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). Item 2. The resin composition according to Item 1.
  3. 前記樹脂組成物は、前記ポリアセタール樹脂７０～９５質量％と、前記コアシェル型エラストマー３０～５質量％を含む（ただし、ポリアセタール樹脂とコアシェル型エラストマーの合計が１００質量％を超えることはない）、請求項１に記載の樹脂組成物。 The resin composition comprises 70 to 95% by mass of the polyacetal resin and 30 to 5% by mass of the core-shell elastomer (however, the total of the polyacetal resin and the core-shell elastomer does not exceed 100% by mass). Item 2. The resin composition according to Item 1.
  4. 前記樹脂組成物は、熱可塑性ポリウレタンを含まないか、熱可塑性ポリウレタンの含有量が、前記コアシェル型エラストマーの含有量の３質量％以下である、請求項１～３のいずれか１項に記載の樹脂組成物。 The one according to any one of claims 1 to 3, wherein the resin composition does not contain thermoplastic polyurethane, or the content of the thermoplastic polyurethane is 3% by mass or less of the content of the core-shell type elastomer. Resin composition.
  5. 前記樹脂組成物を、１００ｍｍ×４０ｍｍ×２ｍｍの平板試験片に成形し、サンシャインウェザーメーターにて、８３℃（ブラックパネル温度）、雨なし、光フィルター：＃２５５の試験環境で、６０時間試験した前後の試験片の色差（ΔＥ＊）が１２以下である、請求項１～４のいずれか１項に記載の樹脂組成物。
    ΔＥ＊＝（（ΔＬ＊）２＋（Δａ＊）２＋（Δｂ＊）２）１／２     The resin composition was molded into a flat plate test piece of 100 mm × 40 mm × 2 mm, and tested with a sunshine weather meter at 83 ° C. (black panel temperature), no rain, and in a test environment of optical filter: # 255 for 60 hours. The resin composition according to any one of claims 1 to 4, wherein the color difference (ΔE *) between the front and rear test pieces is 12 or less.
    ΔE * = ((ΔL *) 2 + (Δa *) 2 + (Δb *) 2 ) 1/2
  6. 前記樹脂組成物を４ｍｍ厚さの多目的試験片に成形し、ＩＳＯ１７８に従って測定した曲げ弾性率が１７００ＭＰａ以下である、請求項１～５のいずれか１項に記載の樹脂組成物。 The resin composition according to any one of claims 1 to 5, wherein the resin composition is molded into a multipurpose test piece having a thickness of 4 mm, and the flexural modulus measured according to ISO178 is 1700 MPa or less.
  7. 前記ＳＰＭ（走査型プローブ顕微鏡、カンチレバーばね定数：９Ｎ／ｍ）を用いて測定したコアシェル型エラストマーのシェル部の縦弾性率とポリアセタール樹脂の縦弾性率の比率（シェル部の縦弾性率／ポリアセタール樹脂の縦弾性率）が０．０８以上である、請求項１～６のいずれか１項に記載の樹脂組成物。 The ratio of the longitudinal elastic modulus of the shell part of the core-shell type elastomer to the longitudinal elastic modulus of the polyacetal resin (vertical elastic modulus of the shell part / polyacetal resin) measured using the SPM (scanning probe microscope, cantilever spring constant: 9 N / m). The resin composition according to any one of claims 1 to 6, wherein has a longitudinal elastic modulus of 0.08 or more.
  8. 請求項１～７のいずれか１項に記載の樹脂組成物から形成された成形品。 A molded product formed from the resin composition according to any one of claims 1 to 7.
  9. 射出成形品である、請求項８に記載の成形品。 The molded product according to claim 8, which is an injection-molded product.
  10. 請求項１～７のいずれか１項に記載の樹脂組成物の製造方法であって、
    ポリアセタール樹脂とコアシェル型エラストマーをタンブラーで混合した後、押出機にて押出し、ストランド状とした後に切断してペレットとすることを含み、
    前記押出機のスクリューの長さＬ（ｍｍ）とスクリューの直径Ｄ（ｍｍ）の比であるＬ／Ｄが、２０＜（Ｌ／Ｄ）＜１００の関係を満たし、
    前記ストランド状とするためのダイノズルが直径１～１０ｍｍである、樹脂組成物の製造方法。     The method for producing a resin composition according to any one of claims 1 to 7.
    It involves mixing a polyacetal resin and a core-shell elastomer with a tumbler, extruding them with an extruder, forming them into strands, and then cutting them into pellets.
    L / D, which is the ratio of the screw length L (mm) of the extruder to the screw diameter D (mm), satisfies the relationship of 20 <(L / D) <100.
    A method for producing a resin composition, wherein the die nozzle for forming the strand shape has a diameter of 1 to 10 mm.
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WO2023238790A1 (en) * 2022-06-09 2023-12-14 グローバルポリアセタール株式会社 Resin composition and molded article
JP7519553B2 (en) 2022-06-09 2024-07-19 グローバルポリアセタール株式会社 Resin composition and molded article
JP7550321B2 (en) 2022-06-09 2024-09-12 グローバルポリアセタール株式会社 Resin composition and molded article

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