JP5908776B2 - Resin composition - Google Patents

Description

  The present invention relates to a resin composition comprising a polypropylene resin and a polylactic acid resin containing a plurality of specific compatibilizers.

  Generally, as a raw material for molding, polypropylene resin, acrylonitrile-butadiene-styrene resin (ABS resin), polyamide resin such as polyamide 6 and polyamide 66, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resin and the like are used. ing. However, moldings produced from such resins are excellent in moldability and mechanical strength, but when discarded, they increase the amount of dust and are hardly decomposed in the natural environment. Even if it remains in the ground semipermanently.

  On the other hand, in recent years, biodegradable resins such as polylactic acid resins have attracted attention from the viewpoint of environmental conservation. Among the biodegradable resins, polylactic acid resin is inexpensive because it can be mass-produced, and even if incinerated after use, considering the carbon dioxide absorbed during plant growth, it is neutral as the carbon balance, It is considered as a resin with low impact on the global environment.

  However, the polylactic acid resin itself is inferior to various conventionally used molding resins in terms of moldability and mechanical strength, and in order to improve them, the polylactic acid resin itself with various additives It is possible to achieve both low environmental impact, moldability, and mechanical strength by modifying the above or by mixing with various conventionally used resins.

  Among various resins conventionally used, polypropylene resin is widely used because of its economical merit and excellent physical properties. Therefore, mixing a low environmental impact polylactic acid resin with a polypropylene resin greatly contributes to the fixation of carbon dioxide.

  However, since the polylactic acid resin is hard and has a property of poor flexibility, the flexibility which is an advantage of the polypropylene resin is lost by mixing with the polylactic acid resin. Therefore, there is a problem that the bending fracture elongation inherently possessed by the polypropylene resin is increased and the tensile fracture elongation is decreased.

  In addition, polypropylene resin and polylactic acid resin have poor compatibility. For this reason, particularly when obtaining a molded body by injection molding, the meltability of the melted resin merging portion (ie, weld) is deteriorated and weld bending There has been a problem that the molded article has low strength and weld bending fracture strain (that is, poor weld weldability).

  In addition, since a resin composition in which a polylactic acid resin is mixed with a polypropylene resin has a low tensile elongation at break (that is, inferior in flexibility), when the resin composition is used for hinges for daily goods, it is repeatedly used. However, there is a problem that fracture near the surface proceeds and tears easily (that is, inferior in folding characteristics).

  Patent Document 1 discloses a method for improving the compatibility between a polypropylene resin and a polylactic acid resin by adding a styrene / ethylenebutylene / styrene block copolymer to a resin composition containing a polylactic acid resin and a polypropylene resin. It is disclosed.

JP 2009-179750 A

  However, although the resin composition of Patent Document 1 has a slightly improved weld fusing property due to improved compatibility, its effect is insufficient. Moreover, it was also inferior in flexibility.

  In view of the prior art, an object of the present invention is to provide a resin composition containing a polypropylene resin and a polylactic acid resin excellent in weld fusion and flexibility.

  As a result of intensive studies to solve such problems, the present inventor can solve the above problems by including a specific amount of plural kinds of compatibilizers in polypropylene resin and polylactic acid resin. And reached the present invention.

That is, the gist of the present invention is as follows.
(1) The total of 100 parts by mass of the polypropylene resin (A) and the polylactic acid resin (B), 0.5 to 2.0 parts by mass of the (meth) acrylic resin (C1), styrene / ethylene butylene / styrene block A resin composition containing 3.5 to 9.0 parts by mass of coalesce (C2) and 5.5 to 20 parts by mass of a styrene / isoprene butadiene / styrene block copolymer (C3), wherein the polypropylene resin (A) The resin composition characterized by mass ratio ((A) / (B)) of a polylactic acid resin (B) being 56 / 44-71 / 29.
(2) Further, the crystal nucleating agent (D) is contained in an amount of 0.10 to 0.50 parts by mass with respect to a total of 100 parts by mass of the polypropylene resin (A) and the polylactic acid resin (B). (1) The resin composition as described.
(3) The resin composition according to (2), wherein the crystal nucleating agent (D) is an alkanetricarboxamide compound.
(4) In the styrene / ethylene butylene / styrene block copolymer (C2), the content of the styrene block is 50% by mass or more, and the resin composition according to any one of (1) to (3) .
(5) A molded product comprising the resin composition according to any one of (1) to (4) as a hinge part.

  Since the resin composition of the present invention is obtained by adding a specific amount of a plurality of compatibilizers to polypropylene resin and polylactic acid resin, the compatibility of polypropylene resin and polylactic acid resin is greatly improved, and weld fusion is achieved. Excellent in heat resistance and impact resistance. For this reason, the molded article suitable for various uses can be obtained from the resin composition of this invention. Moreover, since the resin composition of this invention contains the polylactic acid resin, the load to an environment is small.

It is a figure which shows the measuring method of a bending test.

Hereinafter, the present invention will be described in detail.
The resin composition of the present invention comprises a (meth) acrylic resin (C1), a styrene / ethylenebutylene / styrene block copolymer (hereinafter referred to as “compatibility agent”) as a compatibilizing agent in the polypropylene resin (A) and the polylactic acid resin (B). SEBS ") (C2) and a styrene / isoprene butadiene / styrene block copolymer (hereinafter abbreviated as" vinyl SEEPS ") (C3).

  The polypropylene resin (A) refers to a resin mainly composed of polypropylene. Examples of the polypropylene resin (A) include a homopolymer composed of only a propylene monomer, or a copolymer obtained by copolymerizing a propylene monomer and a monomer other than the propylene monomer. The copolymer may be a random copolymer or a block copolymer. Examples of the monomer other than the propylene monomer include ethylene, butylene, pentene, vinyl acetate, acrylic acid, methacrylic acid, and maleic anhydride. In the present invention, from the viewpoint of weld fusibility, the polypropylene resin (A) is preferably a block copolymer of propylene and ethylene. Examples of such resins include Novatec PP BC4 and BC03C manufactured by Nippon Polypro Co., Ltd. BC03B. The polypropylene resin (A) may be three-dimensionally cross-linked with an organic peroxide or the like, or may be partially chlorinated.

  The melt flow rate at 230 ° C. under a load of 2.16 kg of the polypropylene resin (A) is preferably 0.1 to 100 g / 10 minutes, and more preferably 1 to 50 g / 10 minutes. Impact resistance can be improved by setting the melt flow rate to 0.1 to 100 g / 10 min.

  The polylactic acid resin (B) refers to a resin mainly composed of poly (L-lactic acid), poly (D-lactic acid), and a mixture or copolymer thereof. From the viewpoint of moldability, those mainly composed of poly (L-lactic acid) are preferred. In the polylactic acid resin (B), the content of L-lactic acid is preferably 97% by mass or more, and preferably 98.5% by mass or more.

  In the present invention, the melting point of the polylactic acid resin (B) is preferably 160 ° C. or higher from the viewpoint of impact resistance and heat resistance. The melting point of the polylactic acid resin (B) can be controlled by changing the optical purity of the lactic acid component. For example, when the polylactic acid resin (B) is a copolymer of L-lactic acid and D-lactic acid, if the content of L-lactic acid in the polylactic acid resin (B) is 97% by mass or more, the melting point is 160 ° C. or more. It can be.

  The melt flow rate at 190 ° C. under a load of 2.16 kg of the polylactic acid resin (B) is preferably 0.1 to 50 g / 10 minutes, more preferably 0.2 to 20 g / 10 minutes. More preferably, it is 0.5 to 10 g / 10 min. By setting the melt flow rate to 0.1 to 50 g / 10 min, impact resistance can be improved. The melt flow rate can be controlled by adding various additives. For example, the melt flow rate can be increased by containing a small amount of a chain extender, a diisocyanate compound, a bisoxazoline compound, an epoxy compound, an acid anhydride, and the like. On the other hand, the melt flow rate can be lowered by adding a polyester resin having a high melt flow rate or a low molecular weight compound.

  The polylactic acid resin (B) can be produced by a known melt polymerization method or a combination of a known melt polymerization method and a solid phase polymerization method.

  The mass ratio ((A) / (B)) between the polypropylene resin (A) and the polylactic acid resin (B) needs to be 56/44 to 71/29, and is 56/44 to 63/37. It is preferable. When (A) / (B) is smaller than 56/44, the compatibility between (A) and (B) is deteriorated, and weld weldability and flexibility are deteriorated. On the other hand, when (A) / (B) is larger than 71/29, contribution to the environment is small, which is not preferable.

  In the present invention, a specific amount of three kinds of compatibilizers (meth) acrylic resin (C1), SEBS (C2) and vinyl SEEPS (C3) is specified with respect to the polypropylene resin (A) and the polylactic acid resin (B). The compatibility of (A) and (B) can be drastically improved by containing. The mechanism that enables such excellent effects is not clear, but is presumed to be due to the following reasons.

  In the resin composition of the present invention, the butylene chains of the SEBS (C2) styrene block and the ethylene butylene block have an affinity for the molecular chain of the polypropylene resin (A) and the molecular chain of the polylactic acid resin (B), respectively ( The interface bond of the sea-island structure of A) and (B) is improved, and weld weldability is improved. And by containing a specific amount of (meth) acrylic resin (C1), the affinity between the polypropylene resin (A) and the polylactic acid resin (B) can be further improved, and the weld fusion property can be further improved. . In addition, the side chains of vinyl SEEPS (C3) penetrate between the side chains of (C2), thereby strengthening the interface and improving impact resistance and flexibility as well as weld fusibility. Can do. SEBS (C2) and vinyl SEEBS (C3) are compatibilizers with high flexibility. Therefore, flexibility can be improved by containing a specific amount of these compatibilizers. As a result, weld weldability, flexibility, and impact resistance can all be improved.

  The (meth) acrylic resin (C1) refers to a resin mainly composed of poly (meth) acrylate. The poly (meth) acrylate is obtained by polymerizing a (meth) acrylic monomer alone or by copolymerizing two or more (meth) acrylic monomers. Examples of the (meth) acrylic monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, methyl acrylate, ethyl acrylate, and propyl acrylate. From the viewpoint of heat resistance, methyl methacrylate and acrylic acid A copolymer of methyl is preferred. Examples of such a resin include Acrypet VH manufactured by Mitsubishi Rayon Co., Ltd.

  The content of the (meth) acrylic resin (C1) needs to be 0.5 to 2.0 parts by mass with respect to 100 parts by mass in total of the polypropylene resin (A) and the polylactic acid resin (B). 0.8 to 1.8 parts by mass, and more preferably 1.0 to 1.5 parts by mass. When the content of (meth) acrylic resin (C1) is less than 0.5 parts by mass, when the content of (C1) exceeds 2.0 parts by mass, both are polypropylene resin (A) and polylactic acid resin (B ) Is not improved, and weld weldability is not improved.

  SEBS (C2) is a block copolymer having an ethylene butylene block which is a copolymer of ethylene and butylene between styrene blocks. The styrene block is obtained by copolymerizing a styrene monomer alone or by copolymerizing two or more styrene monomers. Examples of the styrenic monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and ethylstyrene. In the copolymer of ethylene and butylene, ethylene and butylene may be copolymerized randomly or may be block copolymerized. As such a resin, Asahi Kasei Chemicals Corporation Tough Tech H series, M series, JSR Corporation Dynalon 8000, 9000 series are mentioned. Among these, from the viewpoint of compatibility between the polypropylene resin (A) and the polylactic acid resin (B), the content of the styrene block in SEBS (C2) is preferably 50% by mass or more, and 65% by mass or more. It is more preferable.

  The SEBS (C2) content needs to be 3.5 to 9.0 parts by mass with respect to 100 parts by mass in total of the polypropylene resin (A) and the polylactic acid resin (B), and 4.0. It is preferable to set it as -7.5 mass parts, and it is more preferable to set it as 5.5-6.5 mass parts. When the content of SEBS (C2) is less than 3.5 parts by mass, the interface bond of the sea-island structure of (A) and (B) as described above cannot be improved, and weld weldability is not improved. . In addition, the flexibility is not improved, and the tensile elongation at break, bending properties, and impact strength are inferior. On the other hand, when the content of SEBS (C2) exceeds 6.5 parts by mass, the heat resistance is lowered, which is not preferable.

Vinyl SEEPS (C3) is a block copolymer having an isoprene butadiene block which is a copolymer of isoprene and butadiene between styrene blocks. Examples of the styrene monomer used in the styrene block include the monomers listed as the SEBS (C2) styrene monomer. The copolymer of isoprene and butadiene may be a random copolymer of isoprene and butadiene or a block copolymer . In the present invention, from the viewpoint of compatibility between the polypropylene resin (A) and the polylactic acid resin (B), 90% by mass of the carbon-carbon unsaturated double bonds contained in the isoprene butadiene block in the vinyl SEEPS (C3). % Or more is preferably hydrogenated. An example of such a resin is Hibler 7311 manufactured by Kuraray Co., Ltd. Especially, from a compatible viewpoint of polypropylene resin (A) and polylactic acid resin (B), it is preferable that content of the styrene block in vinyl SEEPS (C3) shall be 5-20 mass%, and 8-15 mass % Is more preferable.

  The content of vinyl SEEPS (C3) is required to be 5.5 to 20 parts by mass with respect to 100 parts by mass in total of the polypropylene resin (A) and the polylactic acid resin (B), and 12 to 20 parts by mass. More preferably. When the content of vinyl SEEPS (C3) is less than 5.5 parts by mass, the interfacial bond of the sea-island structure of (A) and (B) cannot be strengthened, and weld weldability is not improved. Flexibility is not improved, and the tensile elongation at break, bending properties and impact strength are poor. On the other hand, when content of vinyl SEEPS (C3) exceeds 20 mass parts, since heat resistance falls, it is unpreferable.

  The resin composition of the present invention preferably further contains a crystal nucleating agent (D). The crystal nucleating agent (D) is preferably an alkanetricarboxamide compound from the viewpoint of heat resistance, and examples of such a compound include tris (methylcyclohexyl) propanetricarboxamide and propanetricarboxamide. Specifically, for example, Rikaclear PC1 (propanetricarboxamide) manufactured by Shin Nippon Rika Co., Ltd. can be mentioned.

  The content of the crystal nucleating agent (D) is preferably 0.10 to 0.50 parts by mass with respect to 100 parts by mass in total of the polypropylene resin (A) and the polylactic acid resin (B). It is more preferable to set it to -0.40 mass part. By setting the content of the crystal nucleating agent (D) to 0.10 to 0.50 parts by mass, crystallization can be promoted and heat resistance can be improved while suppressing a decrease in flexibility.

  Addition of flame retardant, heat stabilizer, antioxidant, weathering agent, plasticizer, lubricant, mold release agent, antistatic agent, pigment, etc. to the resin composition of the present invention, as long as the effects of the present invention are not impaired An agent may be added. Examples of the flame retardant include phosphorus-based flame retardant and metal hydroxide. Examples of the heat stabilizer and the antioxidant include hindered phenols, hindered amines, sulfur compounds, copper compounds, and alkali metal halides.

  The resin composition of the present invention comprises polypropylene resin (A), polylactic acid resin (B), (meth) acrylic resin (C1), SEBS (C2), vinyl SEEPS (C3), crystal nucleating agent (D), additive It can manufacture by mixing. The method of mixing these raw materials is not particularly limited, but is preferably melt-kneaded using a uniaxial or biaxial extruder, and in particular, melt-kneaded using a biaxial extruder from the viewpoint of compatibility. Is preferred. The kneading temperature is preferably (melting point of polylactic acid resin + 5 ° C.) to (melting point of polylactic acid resin + 100 ° C.), and the kneading time is preferably 20 seconds to 30 minutes. When the kneading temperature is less than (the melting point of the polylactic acid resin + 5 ° C.), the kneading may be insufficient in any case where the kneading time is less than 20 seconds. On the other hand, when the kneading temperature exceeds (the melting point of the polylactic acid resin + 100 ° C.) or when the kneading time exceeds 30 minutes, the resin composition may be decomposed or colored.

  The resin composition of the present invention can be formed into various molded bodies by molding methods such as injection molding, blow molding, extrusion molding, inflation molding, vacuum molding after sheet processing, pressure molding, vacuum pressure molding and the like. In particular, it is suitable for the injection molding method, and in addition to general injection molding, gas injection molding, injection press molding, and the like can be performed. The injection molding conditions are appropriately selected depending on the type and content ratio of the resin composition, but the cylinder temperature is preferably equal to or higher than the melting point or flow start temperature of the resin composition, and more preferably 190 to 270 ° C. The mold temperature is preferably (the melting point of the resin composition−20 ° C.) or less. If the molding temperature is too low, a short shot may occur in the molded product, or the operability may become unstable due to overload. On the other hand, if the molding temperature is too high, the resin composition may be decomposed and the strength of the resulting molded product may be reduced or colored.

  Molded articles obtained from the resin composition of the present invention include various daily necessaries and miscellaneous goods using polypropylene resin, various parts and casings around personal computers, mobile phone parts and casings, and other OA equipment parts. It can be used for resin parts for automobiles such as resin parts for electric appliances, bumpers, instrument panels, console boxes, garnishes, door trims, ceilings, floors, and panels around engines. Moreover, it can also be set as a film, a sheet | seat, and a hollow molded article.

  Especially, since the resin composition of this invention is excellent in a softness | flexibility, it is excellent also in the bending characteristic, and can be used suitably especially as various hinges.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these inventions.
The measuring method used for evaluation of the resin composition of an Example and a comparative example is as follows.

(1) Melt flow rate It measured based on JISK7210 (test condition 4). The polypropylene resin was measured at 230 ° C. under a load of 2.16 kg, and the polylactic acid resin was measured at 190 ° C. under a load of 2.16 kg.
(2) Tensile elongation at break Measured in accordance with ISO 527 using a test piece for measuring general physical properties having a width of 10 mm and a thickness of 4 mm.

(3) Charpy impact strength It measured based on ISO179 using the test piece for a general physical property measurement of width 10mm x thickness 4mm.
(4) Deflection temperature under load (DTUL)
Measurement was performed under a load of 0.45 MPa in accordance with ISO75 using a test piece for measuring general physical properties having a width of 10 mm and a thickness of 4 mm.

(5) Weld Bending Strength and Weld Bending Breaking Strain Measured according to ISO 178 using a weld measurement specimen having a width of 12.7 mm and a thickness of 3.2 mm.
(6) Bending Characteristics Using a test piece for measuring general physical properties having a width of 12.7 mm and a thickness of 0.8 mm, the specimen was bent to an angle of 170 ° in both directions with the crease 1 as a fulcrum as shown in FIG. The operation of bending in both directions was defined as one time, this operation was repeated, and the number of times until breakage occurred was measured.

Moreover, the various raw materials used for the Example and the comparative example are as follows.
<Polypropylene resin (A)>
(1) Nippon Polypro Co., Ltd., Novatec PP BC03C, block copolymer of propylene and ethylene, melt flow rate 30 g / 10 min (under 2.16 kg load, 230 ° C.)

<Polylactic acid resin (B)>
(1) PLA 3001D, L-form content 98.6% by mass, melt flow rate 10 g / 10 min (190 ° C. under 2.16 kg load), manufactured by Cargill Dow

<(Meth) acrylic resin (C1)>
(1) Mitsubishi Rayon Co., Ltd., Acrypet VH, Copolymer of methyl methacrylate and methyl acrylate <SEBS (C2)>
(1) Asahi Kasei Corporation, Tuftec H1043, content of styrene block 67% by mass
(2) Asahi Kasei Corporation, Tuftec M1943, content of styrene block 20% by mass
(3) Made by JSR, Dynalon 8630P, styrene block content 15% by mass

<Vinyl SEEPS (C3)>
(1) Kuraray Co., Ltd., Hibler 7311, content of styrene block 12% by mass, and 90% by mole or more of the carbon-carbon unsaturated double bond contained in the isoprene butadiene block is hydrogenated.

<Other compatibilizer>
(1) Kuraray, Septon 2004, styrene block content 18% by mass, styrene / isoprene / styrene copolymer (2) Sumitomo Chemical Co., Ltd., Bond First E, styrene block content 0% by mass, ethylene Glycidyl methacrylate copolymer

<Crystal nucleating agent (D)>
(1) Alkanetricarboxamide compound manufactured by Shin Nippon Rika Co., Ltd., Rikaclear PC1, tris (methylcyclohexyl) propane tricarboxamide (2) manufactured by talc Hayashi Kasei Co., Ltd., MW-HST
(3) Trimesic acid amide compound, manufactured by Shin Nippon Rika Co., Ltd., TF-1
(4) Ethylene bishydroxystearic acid amide compound Kawaken Fine Chemicals, WX-1

Example 1
Using a twin screw extruder (TEM37BS type manufactured by Toshiba Machine Co., Ltd.), 68 parts by mass of Novatec PP BC03C as a polypropylene resin, 32 parts by mass of PLA 3001D as a polylactic acid resin, and 1.2 parts of Acrypet VH as a (meth) acrylic resin Mass parts, 6.1 parts by mass of Tuftec H1043 as SEBS, 15 parts by mass of Hibler 7311 as vinyl SEEPS, and 0.24 parts by mass of Ricclear CL1 as a crystal nucleating agent were dry blended and supplied from the supply port of the extruder. The barrel temperature was 180 ° C., the screw rotation speed was 150 rpm, the discharge was 20 kg / hour, and the venting was performed. The resin extruded from the tip of the extruder was cut into pellets to obtain resin composition pellets.

  The obtained pellets were dried with hot air at 85 ° C. for 10 hours, and then a test piece for measuring general physical properties of a mold surface temperature of 35 ° C. and a width of 10 mm × thickness of 4 mm using an IS-80G injection molding machine manufactured by Toshiba Machine Co., Ltd. A test piece for measuring general physical properties of width 12.7 mm × thickness 0.8 mm and a test piece for weld measurement of width 12.7 mm × thickness 3.2 mm (test pieces filled with resin from both ends and welded at the center) Produced.

Examples 2-18 and Comparative Examples 1-20
Except for changing the types and contents of polypropylene resin, polylactic acid resin, compatibilizer, and crystal nucleating agent as shown in Tables 1 and 2, the same operation as in Example 1 was performed to obtain pellets, and various test pieces were obtained. Produced.

  The compositions and characteristic values of the resin compositions of Examples 1 to 18 and Comparative Examples 1 to 20 are shown in Tables 1 and 2.

  Since the resin compositions of Examples 1 to 18 were excellent in both weld fusibility and flexibility, they were excellent in all of weld bending strength, weld bending break strain, tensile break elongation, and bending characteristics. Moreover, DTUL and Charpy impact strength were also high.

Since the content of the polypropylene resin was lower than the range specified in the present invention, the resin composition of Comparative Example 1 had low tensile rupture elongation, weld bending strength, and weld bending rupture strain, and was inferior in bending characteristics.
In the resin compositions of Comparative Examples 2 and 3, the content of the (meth) acrylic resin was out of the range specified in the present invention, so the weld bending strength and the weld bending fracture strain were low.
Since the resin composition of Comparative Example 4 had a SEBS content lower than the range specified in the present invention, the tensile breaking elongation, Charpy impact strength, weld bending strength, weld bending breaking strain was low, and the bending properties were inferior. It was.
The resin composition of Comparative Example 5 had a low DTUL because the SEBS content was higher than the range specified in the present invention.
In the resin composition of Comparative Example 6, the content of vinyl SEEPS was lower than the range specified in the present invention, so the tensile breaking elongation, Charpy impact strength, weld bending strength, weld bending breaking strain was low, and the bending properties were inferior. It was.
The resin composition of Comparative Example 7 had a low DTUL because the vinyl SEEPS content was higher than the range specified in the present invention.
Since the resin compositions of Comparative Examples 8 and 9 used styrene / isoprene / styrene copolymer and ethylene / glycidyl methacrylate copolymer instead of SEBS, respectively, tensile elongation at break, Charpy impact strength, weld bending strength Further, the weld bending fracture strain and the bending characteristics were not sufficiently improved to achieve the effects of the present invention.
In the resin composition of Comparative Example 10, the total amount of the compatibilizing agent was the same as in Example 1, but the SEBS content was lower than the range specified in the present invention, so that the tensile elongation at break and Charpy impact strength were The weld bending strength and weld bending breaking strain were low, and the bending characteristics were inferior.

Since the resin compositions of Comparative Examples 11 and 12 used styrene / isoprene / styrene copolymer and ethylene / glycidyl methacrylate copolymer instead of vinyl SEEPS, respectively, tensile elongation at break, Charpy impact strength, weld bending The strength and weld bending fracture strain were low, and the bending properties were inferior.
Since the resin composition of Comparative Example 13 did not contain vinyl SEEPS, the tensile breaking elongation, Charpy impact strength, weld bending strength and weld bending breaking strain were low, and the bending properties were inferior.
The resin composition of Comparative Example 14 had a low DTUL because the content of the compatibilizer SEBS was high. Further, since vinyl SEEPS was not contained, the tensile breaking elongation, Charpy impact strength, weld bending strength, weld bending breaking strain, and bending characteristics were not sufficiently improved to exhibit the effects of the present invention.
In the resin composition of Comparative Example 15, the total amount of the compatibilizing agent was the same as in Example 1, but the content of vinyl SEEPS was lower than the range specified in the present invention. The strength, DTUL, weld bending strength and weld bending breaking strain were low, and the bending properties were inferior.
Since the resin composition of Comparative Example 16 used styrene / isoprene / styrene copolymer instead of vinyl SEEPS, the tensile elongation at break, Charpy impact strength, weld bend strength, weld bend break strain was low, and the bending properties were improved. It was inferior.
Since the resin composition of Comparative Example 17 did not contain SEBS and vinyl SEEPS, the tensile breaking elongation, Charpy impact strength, weld bending strength and weld bending breaking strain were low, and the bending properties were inferior.
Since the resin composition of Comparative Example 18 did not contain (meth) acrylic acid resin and vinyl SEEPS, the tensile elongation at break, Charpy impact strength, weld bending strength, weld bending breaking strain was low, and the bending properties were inferior. It was.
Since the resin composition of Comparative Example 19 did not contain (meth) acrylic acid resin and SEBS, the tensile breaking elongation, Charpy impact strength, weld bending strength, weld bending breaking strain was low, and the bending properties were inferior. .
Since the resin composition of Comparative Example 20 did not contain any compatibilizing agent, the tensile breaking elongation, Charpy impact strength, weld bending strength and weld bending breaking strain were low, and the bending properties were inferior.

1 crease

Claims (5)

For a total of 100 parts by mass of polypropylene resin (A) and polylactic acid resin (B), 0.5 to 2.0 parts by mass of (meth) acrylic resin (C1), styrene / ethylenebutylene / styrene block copolymer (C2) ) 3.5 to 9.0 parts by mass, and styrene / isoprene butadiene / styrene block copolymer (C3) 5.5 to 20 parts by mass, the polypropylene resin (A) and polylactic acid The resin composition characterized by mass ratio ((A) / (B)) with resin (B) being 56/44 to 71/29. Further, the crystal nucleating agent (D) is contained in an amount of 0.10 to 0.50 parts by mass with respect to a total of 100 parts by mass of the polypropylene resin (A) and the polylactic acid resin (B). The resin composition as described. 3. The resin composition according to claim 2, wherein the crystal nucleating agent (D) is an alkanetricarboxamide compound. 4. The resin composition according to claim 1, wherein the content of the styrene block is 50% by mass or more in the styrene / ethylene butylene / styrene block copolymer (C2). A molded product comprising the resin composition according to any one of claims 1 to 4 as a hinge portion.