JP5769169B2 - Resin composition containing polylactic acid and method for producing the same - Google Patents

Description

  The present invention relates to a resin composition containing polylactic acid and a method for producing the same.

  In recent years, the need for environmentally compatible resins has been greatly increased in order to improve the global environment. Polylactic acid is known as an inexpensive plant-derived resin, but has a problem that heat resistance and mechanical properties are not sufficient. On the other hand, polyamide 11 is also a plant-derived resin and exhibits excellent heat resistance, but has a problem that it is very expensive. Therefore, the uses of polylactic acid and polyamide 11 were both limited.

  If polylactic acid and polyamide 11 can be blended appropriately, it is expected to obtain a balanced environmentally compatible resin, and thus several proposals have been made so far. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2004-51835) and Patent Document 2 (Japanese Patent Laid-Open No. 2009-209234) describe resin compositions obtained by simply blending polylactic acid and polyamide 11. . However, the performance of the composition was not satisfactory. Further, the patent document does not describe a compatibilizing agent for polylactic acid and polyamide 11.

  Patent Document 3 (Japanese Patent Publication No. 2009-540090) discloses that a composite material having polylactic acid as a continuous phase, polyamide 11 or the like as a dispersed phase, and a polyolefin having a functional group as a compatibilizer has excellent impact resistance. Have been described. In the examples, only ethylene-methyl methacrylate-glycidyl methacrylate copolymer (E-MMA-EGMA copolymer) is described as a compatibilizing agent. This document does not describe physical properties other than impact resistance.

  Patent Document 4 (Japanese Patent Publication No. 2010-516852) describes a resin composition containing polyamide 11 as a continuous phase, polylactic acid as a dispersed phase, and an E-MMA-EGMA copolymer as a compatibilizing agent. . Patent Document 5 (Japanese Patent Application Laid-Open No. 2010-189472) describes a resin composition comprising polylactic acid, polyamide 11, and a core-shell type graft copolymer. However, the resin compositions described in Patent Documents 4 and 5 are very expensive because the polyamide 11 is a continuous phase.

JP 2004-51835 A JP 2009-209234 A Special table 2009-540090 Special table 2010-516852 gazette JP 2010-189472 A

  As described above, a resin composition comprising polylactic acid and polyamide 11 has been studied as an environmentally compatible resin. However, an inexpensive resin composition having excellent mechanical properties such as ductility and impact resistance, and heat resistance is still available. Not obtained.

  In view of the above circumstances, an object of the present invention is to provide an inexpensive resin composition that is excellent in mechanical properties such as ductility and impact resistance and heat resistance.

The present inventors have prepared an epoxy group-containing ethylene copolymer or an epoxy group-containing styrene block copolymer grafted with polylactic acid and polyamide 11 and polystyrene or polyalkyl (meth) acrylate as a compatibilizing agent. The present invention has been completed by finding that the above problems can be solved by a resin composition containing polylactic acid as a continuous phase. That is, the subject is the following present invention:
(A) Epoxy group-containing ethylene copolymer (C1) and / or styrene-based block copolymer containing epoxy group grafted with polylactic acid, (B) polyamide 11 and (C) polystyrene or polyalkyl (meth) acrylate (C2), wherein the component (A) is a continuous phase and the component (B) and the component (C) are dispersed phases.

  According to the present invention, an inexpensive resin composition having excellent mechanical properties such as ductility and impact resistance and heat resistance can be provided.

Transmission electron microscope image of the resin composition obtained in Example 4 Transmission electron microscope image of the resin composition obtained in Comparative Example 3

  Hereinafter, the present invention will be described in detail. In the present specification, “to” includes values at both ends thereof.

1. Resin Composition of the Present Invention The resin composition of the present invention comprises an epoxy group-containing ethylene grafted with polylactic acid as the component (A), polyamide 11 as the component (B), and polystyrene or polyalkyl (meth) acrylate as the component (C). A styrene block copolymer (C2) containing an epoxy copolymer (C1) and / or an epoxy group.

(1) Component A
Polylactic acid is a polymer having a repeating unit represented by the following general formula (1).

  The weight average molecular weight of the polylactic acid is not particularly limited, but the lower limit is preferably 5,000 or more, more preferably 10,000 or more, and further preferably 20,000 or more. When the weight average molecular weight of the polylactic acid is less than the lower limit, mechanical properties such as strength and elastic modulus tend to be insufficient. The upper limit of the weight average molecular weight is preferably 1,000,000 or less. When this weight average molecular weight is exceeded, the moldability tends to be lowered.

  The production method of polylactic acid is not particularly limited, and D-lactic acid and L-lactic acid may be directly polymerized, and ring-opening polymerization of lactic acid cyclic dimer D-lactide, L-lactide, and meso-lactide is performed. May be. The polylactic acid may be a copolymer of the D-form material and the L-form material. In this case, the content of one of the D-form material and the L-form material is 90 mol% or more. Preferably, it is 97 mol% or more, more preferably 99 mol% or more. If the ratio is less than 90 mol%, the stereoregularity is lowered and crystallization is difficult to occur, so that the heat resistance may be lowered. In the present invention, the lactic acid homopolymer or lactic acid copolymer thus produced is preferably used as the component (A). Alternatively, a blend of polylactic acid whose main component is D-form and polylactic acid whose main component is L-form may be used.

  Furthermore, as a component (A), in addition to lactic acid or lactide, a copolymer obtained by copolymerizing a different monomer such as glycolide or caprolactone, or a blend of a homopolymer of the different monomer and a lactic acid homopolymer may be used. Good. In this case, the proportion of the component derived from the different monomer in the component (A) is preferably 30 mol% or less in terms of monomer.

  From the viewpoint of the heat resistance of the resulting resin composition, the melting point of the polylactic acid used in the present invention is preferably 140 to 250 ° C, more preferably 150 to 230 ° C.

(2) Component (B)
The polyamide 11 is one of soft polyamides, and is a polymer mainly composed of a repeating unit represented by the following general formula (2). The main component means that the repeating unit represented by the following general formula (2) is contained in an amount of 80 to 100 mol%, preferably 90 to 100 mol%.

In the formula, R ¹ is an alkylene group having 10 carbon atoms. The polyamide 11 can be produced by a known method. For example, the polyamide 11 is obtained by polycondensation of 11-aminoundecanoic acid obtained from ricinoleic acid in natural castor oil. In the production, additives such as various catalysts and heat stabilizers may be used. Moreover, you may copolymerize the monomer which gives the repeating unit represented except general formula (2). In that case, the usage-amount of the said compound has preferable 20 mol% or less in all the monomers, and 10 mol% or less is more preferable.

The melting point of the polyamide 11 in the present invention is preferably 170 to 200 ° C, more preferably 175 to 195 ° C.
Further, MI (235 ° C., 2.16 N load) of polyamide 11 is preferably 10 to 75, more preferably 15 to 55, and particularly preferably 25 to 50. When the polyamide 11 is out of the above range, the heat resistance of the composition may be lowered or the moldability may be insufficient.

(3) Component (C)
As the component (C), an epoxy group-containing ethylene copolymer (C1) grafted with polystyrene or polyalkyl (meth) acrylate and / or a styrene block copolymer (C2) containing an epoxy group is used. The above “and / or” means that C1 and C2 are used alone or in combination.

1) Epoxy group-containing ethylene copolymer grafted with polystyrene or polyalkyl (meth) acrylate (C1)
The copolymer of C1 is a polymer in which one or both of polystyrene and polyalkyl (meth) acrylate segments are grafted as branches on the trunk of an epoxy group-containing ethylene copolymer segment.

The epoxy group-containing ethylene copolymer is an ethylene-based binary copolymer or an ethylene-based terpolymer. The ethylene-based binary copolymer is a copolymer comprising (a) an ethylene unit, (b) an ethylenically unsaturated carboxylic acid glycidyl ester unit or an ethylenically unsaturated hydrocarbon group glycidyl ether unit. The ethylene-based terpolymer includes (a) an ethylene unit, (b) an ethylenically unsaturated carboxylic acid glycidyl ester unit or an ethylenically unsaturated hydrocarbon group glycidyl ether unit, and (c) a vinyl acetate unit or methyl acrylate. It is a copolymer consisting of units. An ethylene unit is a part derived from ethylene in a copolymer, and is specifically a unit represented by — (CH ₂ —CH ₂ ) —. Ethylenically unsaturated carboxylic acid glycidyl ester units and the like are defined similarly.

  When the trunk is an ethylene-based binary copolymer, the composition thereof is preferably (a) unit: (b) unit = 95-40% by mass: 5-60% by mass, 90-50% by mass: 10-50% by mass. % Is more preferable.

  When the trunk is an ethylene-based terpolymer, the composition is preferably (a) unit: (b) unit: (c) unit = 40 to 94% by mass: 1 to 20% by mass: 5 to 40% by mass. 50-90 mass%: 2-15 mass%: 8-35 mass% is more preferable. (B) Compounds that give an ethylenically unsaturated carboxylic acid glycidyl ester unit or an ethylenically unsaturated hydrocarbon group glycidyl ether unit are represented by the following general formulas (3) and (4), respectively.

  In General formula (3), R is a C2-C13 hydrocarbon group which has one ethylene bond. The carbon number of R is preferably 2-10.

  Examples of the ethylenically unsaturated carboxylic acid glycidyl ester unit represented by the general formula (3) include glycidyl α, β-unsaturated carboxylic acid such as glycidyl acrylate, glycidyl methacrylate, and diglycidyl itaconate.

In General formula (4), R is a C2-C13 hydrocarbon group which has one ethylene bond. X is —CH ₂ —O— or a group represented by the following chemical formula (4-1). The carbon number of R is preferably 2-10.

  The polystyrene segment which is a branch is a segment formed by polymerizing styrene. The ratio of the epoxy group-containing ethylene copolymer segment (trunk) and the polystyrene segment (branch) is preferably 50 to 99 mass%: 50 to 1 mass%, more preferably 60 to 80 mass%: 40 to 20 mass%. . In order to bond the epoxy group-containing ethylene copolymer segment and the polystyrene segment, a known method may be used. For example, as described in JP-A-2007-63506, it can be obtained by polymerizing styrene by adding styrene to a solution of an ethylene copolymer segment in the presence of a peroxide.

  The polystyrene segment in the epoxy group-containing ethylene copolymer grafted with polystyrene has an affinity for the hydrophobic hydrocarbon group in the polyamide 11. Moreover, the epoxy group in the copolymer can react with a functional group such as a carboxyl group in polylactic acid or an amino group or a carboxyl group in polyamide 11. For this reason, the copolymer acts as a compatibilizing agent.

  The MI of the epoxy group-containing ethylene copolymer grafted with polystyrene is preferably 0.01 to 50 g / 10 min, more preferably 0.05 to 30 g / 10 min. MI is measured under the conditions of a resin temperature of 230 ° C. and a measurement load of 21 N (2.16 kg · f) in accordance with a method defined in JIS K7210. When MI is less than 0.01 g / 10 min or exceeds 50 g / 10 min, the affinity between the polystyrene-grafted epoxy group-containing ethylene copolymer and polyamide 11 or the like decreases, or the appearance of the resulting molded product May get worse.

  The polyalkyl (meth) acrylate segment as another branch is a segment formed by polymerizing alkyl (meth) acrylate. Alkyl (meth) acrylate is an alkyl ester of acrylic acid or an alkyl ester of methacrylic acid. Ester groups in the polyalkyl (meth) acrylate segment can react with the functional groups in polylactic acid and polyamide 11. Therefore, the copolymer also functions as a compatibilizing agent. Examples of the alkyl group in the ester group in the polyalkyl (meth) acrylate segment include an alkyl group having 1 to 4 carbon atoms. From the viewpoint of promoting the reaction, the ester group is preferably not bulky. Therefore, the alkyl group is preferably a methyl group or an ethyl group. The ratio of the epoxy group-containing ethylene copolymer segment (trunk) to the polyalkyl (meth) acrylate segment (trunk) and the bonding method are as described above.

  The MI of a copolymer obtained by grafting a polyalkyl (meth) acrylate segment onto an epoxy group-containing ethylene copolymer segment is preferably 0.01 to 50 g / 10 min from the viewpoint of the effect as a compatibilizer. 05-30g / 10min is more preferable.

  Both the polyalkyl (meth) acrylate segment and the polystyrene segment may be grafted to the epoxy group-containing ethylene copolymer segment. In this case, the total amount of the two segments may be the amount described above.

2) Styrenic block copolymer containing epoxy group (C2)
The copolymer of C2 is a polymer obtained by subjecting a styrene block copolymer to epoxy modification. The styrene block copolymer is a block copolymer of styrene and a conjugated diene compound. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 3-butyl-1,3-octadiene, and butadiene or isoprene is preferable. The styrenic block copolymer may be hydrogenated. In the present invention, a styrene-butadiene-styrene triblock copolymer is preferable in view of availability. Such a styrenic block copolymer or a hydrogenated product thereof can be prepared, for example, by the method described in JP-B-40-23798 and JP-A-59-133203.

  The epoxy modification of the styrenic block copolymer is to introduce an epoxy group into the styrenic block copolymer, and preferably to introduce a compound having a glycidyl group. Examples of the compound having a glycidyl group include unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxy alkenes, and specific examples thereof include glycidyl methacrylate, glycidyl acrylate, butenecarboxylic acid glycidyl esters, allyl glycidyl ether. Etc. Glycidyl methacrylate and glycidyl acrylate are preferable from the viewpoint of availability.

  The epoxy group thus introduced reacts with the functional group of component (A) or (B). The styrene block has an affinity for the hydrophobic group of component (B). For this reason, the copolymer functions as a compatibilizing agent.

  A method for introducing the compound having a glycidyl group into the styrene block copolymer is not particularly limited, but the compound can be introduced by graft copolymerizing the compound with the styrene block copolymer. At this time, the compound having a glycidyl group is preferably introduced into the butadiene block of the styrenic block copolymer. When the introduced epoxy group can move freely, the reactivity with the component (A) or (B) increases, so that the epoxy group is not present in the butadiene block main chain but in the graft chain extending from the butadiene block. More preferably it is present.

  The epoxy group content in the C2 copolymer can be expressed in terms of oxirane oxygen concentration. The oxirane oxygen concentration can be determined by titrating the mass% of oxirane oxygen derived from the epoxy group in the block copolymer with an acetic acid solution of hydrogen bromide according to ASTM-1652. The oxirane oxygen concentration is preferably 0.1 to 8% by mass, more preferably 0.2 to 5% by mass, and still more preferably 0.4 to 3% by mass. If the oxirane oxygen concentration is outside these ranges, the reactivity between the C2 copolymer and the component (A) or (B) may be insufficient, or the molding processability of the composition may be insufficient. This is not preferable.

  The lower limit of the styrene content in the C2 copolymer is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more. Moreover, 80 mass% or less is preferable and, as for the upper limit of styrene content, 50 mass% or less is more preferable.

  The MI (190 ° C., 2.16 N load) of the copolymer is preferably 2 to 40 (g / 10 minutes), and more preferably 4 to 20 (g / 10 minutes).

(4) Composition ratio In the present invention, the composition ratio of each component is determined so that component (A) is a continuous phase and component (B) and component (C) are dispersed phases. When component (A) is a continuous phase, a resin composition having low cost and excellent performance is obtained. The mass ratio of the component (A) and the component (B) is preferably 50 to 99/50 to 1, more preferably 56 to 95/44 to 5, still more preferably 60 to 90/40 to 10, and 70 to 80. / 30 to 20 is even more preferable. If it is out of the above range, the component (B) may form a continuous phase, which is not preferable.

  Moreover, 1-50 mass parts is preferable, as for the quantity of the component (C) with respect to 100 mass parts of total amounts of a component (A) and a component (B), 2-40 mass parts is more preferable, and 4-30 mass parts is further. preferable.

(5) Other components An electrical conductivity-imparting substance can be further added to the resin composition of the present invention to obtain an electrically conductive resin composition.

  The resin composition of the present invention may further include other compounding agents depending on applications and purposes, for example, electrical conductivity imparting substances such as carbon black, carbon fiber, graphite, metal fiber, carbon nanotube, and metal oxide, Anti-plasticizers such as inorganic fillers such as talc, mica, calcium carbonate, wollastonite, glass fibers, coupling agents, reinforcing agents, flame retardant aids, stabilizers, pigments, mold release agents, or elastomers An impact modifier or the like can be blended. The compounding quantity of these compounding agents is 60 mass parts or less with respect to a total of 100 mass parts of component (A), (B) and (C), Preferably it is 40 mass parts or less.

(6) Structure of the resin composition of the present invention In the resin composition of the present invention, the polylactic acid of the component (A) forms a continuous phase and the other components form a dispersed phase. Furthermore, a part of the component (C) may be dispersed in the component (A) phase, or may be dispersed in the component (B) phase. As described above, the component (C) reacts not only with the functional group in the component (A) but also with the functional group in the component (B), and these reaction products become the phases of the components (A) and (B). Increase solubility. From the viewpoint of enhancing this effect, the (C) phase is preferably dispersed as fine particles having a number average particle diameter of 1 μm or less in the (A) and (B) phases, and a size of 0.5 μm or less. More preferably, it is dispersed as fine particles. The lower limit of the number average particle diameter is preferably 5 nm or more. The phase structure can be observed with a transmission electron microscope. That is, after dyeing the composition with ruthenium oxide or the like, an ultrathin section is prepared using a microtome or the like, and the phase structure can be observed with a transmission electron microscope. At that time, when the section is dyed with ruthenium oxide, the component (C) is most easily dyed, the component (B) is easily dyed next, and the component (A) is most difficult to dye. The form of the component can be observed.

  In the present invention, since the polylactic acid of the component (A) is a continuous phase, the polylactic acid is inexpensive and includes the polyamide 11 of the component (B) excellent in heat resistance. Moreover, since most of the components are plant-derived resins, the resin composition of the present invention also has environmental compatibility. Furthermore, since the resin composition of the present invention has the above-described structure, it is considered that the resin composition has excellent heat resistance, impact resistance, and ductility that have not existed in the past.

  In general, the compatibility between the component (A) polylactic acid and the component (B) polyamide 11 is not sufficient, and a resin composition obtained by simply mixing the two is not sufficient because the adhesion at the interface between the two is not sufficient. Dynamic characteristics cannot be demonstrated. However, in this invention, since a component (C) can react with a component (A) and (B), it becomes a resin composition excellent in mechanical characteristics.

2. Production method of resin composition of the present invention The resin composition of the present invention can be obtained by melt-kneading components (A), (B) and (C). For melt-kneading, a kneading machine such as a batch-type twin-screw kneader, a single-screw extruder, or a twin-screw extruder can be used. Among them, a twin-screw extruder capable of strong kneading and capable of continuous melt-kneading. Is preferably used. The melt kneading temperature is preferably 180 to 260 ° C, more preferably 190 to 240 ° C, and further preferably 200 to 230 ° C.

  The method of melt kneading is not particularly limited. For example, the component (A) polylactic acid, the component (B) polyamide 11 and the component (C) copolymer may be melt-kneaded together. Alternatively, component (A) and component (C) are previously melt-kneaded and then component (B) is added and melt-kneaded. Component (B) and component (C) are previously melt-kneaded and then component (A) is added. Alternatively, a melt kneading method may be used. Furthermore, the component (A) and the component (C) are supplied from the upstream side of the extruder and the component (B) is supplied from the downstream side of the extruder and melt kneaded, or the component (B) and the component (C ) May be supplied from the upstream side of the extruder, and the component (A) may be supplied from the downstream side of the extruder and melt kneaded.

  When the resin composition is produced in this manner, the polyamide 11 of the component (B) is dispersed in the polylactic acid continuous phase of the component (A), and the component (C) is easily finely dispersed with a particle size of 1 μm or less. . In the present invention, the step of melt-kneading the components (A), (B) and (C) is preferably carried out using a kneader. As the kneader, a twin screw extruder excellent in productivity is preferable.

3. Processing method and application of the resin composition of the present invention The resin composition of the present invention is easily processed into a molded product by a processing method used for ordinary thermoplastic resin molded products. Examples of processing methods include injection molding, extrusion molding, film / sheet molding, fiber molding, vacuum molding, blow molding, press molding, calendar molding, foam molding, and the like. The resin composition in the present invention is excellent in heat resistance, impact resistance, ductility and the like, and has environmental compatibility, so that it is an electric / electronic part, a communication part, a film / sheet for packaging, a fiber, an automobile part, It can be widely applied to household electric appliances such as refrigerators and televisions.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

(1) Physical property test / Tensile test: A tensile test was performed using a Strograph VES 50 type manufactured by Toyo Seiki Seisakusho Co., Ltd. with a load cell of 1 kN, a distance between chucks of 40 mm, and a stretching speed of 10 mm / min.
・ Tensile impact test: DG digital impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd., load 4J due to the mass of the hammer, distance from the center of rotation of the hammer to the center of gravity 0.23 mm, hammer lifting angle 150 °, period 0 Measurement was performed in accordance with JIS 7160 at 962 sec and a temperature of 20 ° C.

  (2) Components of resin composition

1) Component (A)
Polylactic acid (Lacia H400 manufactured by Mitsui Chemicals, Inc.)
Melting point 168 ° C
・ Glass transition point 61 ℃
Mn = 130,000 (g / mol), Mw = 200,000 (g / mol)

2) Component (B)
Polyamide 11 (Rilsan BMN O manufactured by Arkema Co., Ltd.)
Melting point (DSC measurement) 187 ° C
・ Glass transition temperature 37 ℃
-MI (235 degreeC, 2.16N load) 30-40 (g / 10min)

3) Component (C)
Styrene-butadiene-styrene block copolymer containing an epoxy group (Epofriend AT501 manufactured by Daicel Chemical Industries, Ltd. (indicated as Cb in the table))
MI (JIS K7210, 190 ° C., 2.16 kg load) = 7 g / 10 minutes Specific gravity: 0.985 (g / cm ³ )
・ Styrene content 40% by mass
・ Oxirane oxygen concentration 1.5% by mass
Styrene graft EGMA (manufactured by NOF Corporation, Modiper A4100 (shown as C-sg in the table))
-Graft copolymer in which polystyrene segments are grafted onto segments consisting of ethylene units / ethylenically unsaturated carboxylic acid glycidyl ester (EGMA) units (segment ratio is 70/30 (mass ratio))
・ Glycidyl methacrylate content in EGMA 15% by mass
Melting point 95 ° C
・ Glass transition temperature -28 ℃

Methyl methacrylate (MMA) -grafted EGMA (manufactured by NOF Corporation, Modiper A4200 (denoted as C-mg in the table))
A graft copolymer in which a polyMMA segment is grafted on a segment composed of ethylene units / ethylenically unsaturated carboxylic acid glycidyl ester (EGMA) units (segment ratio is 70/30 (mass ratio))
・ Glycidyl methacrylate content in EGMA 15% by mass
Melting point 95 ° C
・ Glass transition temperature -28 ℃

[Examples 1-3 and Comparative Examples 1-2]
After the components shown in Table 1 were thoroughly dry blended, a lab plast mill 4M150 manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as the kneading machine, kneading temperature 210 ° C., screw rotation speed 50 rpm, kneading time 5 minutes. As a result, each component was melt-kneaded.

  The obtained kneaded material was preheated at a temperature of 210 ° C. for 3 minutes and pressed at a pressure of 10 MPa for 5 minutes, and then rapidly cooled to 0 ° C. to obtain a sheet having a thickness of about 0.5 mm. However, Comparative Example 1 was press-molded using the pellets as they were without kneading.

  For the tensile test, a press sheet punched into a mini dumbbell shape having a length of 16 mm in the straight part of the parallel part was used. For the Charpy impact test, a press sheet having a dumbbell shape, punched into a total length of 80 mm, a thickness of 0.5 mm, a parallel part width of 10 mm, a parallel part length of 10 mm, and a grip part width of 15 mm was used.

  As shown in Table 1, in Examples 1 to 5 containing Component C, a significant improvement in impact strength was observed. Moreover, from Examples 1, 4, and 5, it was also clarified that the elongation percentage was significantly improved by increasing the amount of component (B) added.

  1 is a transmission electron microscope image of the resin composition obtained in Example 4. FIG. First, after cutting out the center part of the injection-molded piece with a cutter, it was dyed with ruthenium oxide and subjected to microtome cutting. Next, the obtained section was observed with a transmission electron microscope to obtain the image shown in FIG. Since component (C) is most easily dyed, it shows a black contrast on the photograph, and component (B) is easily dyed next, so it shows a gray contrast on the photograph, and component (A) is the least dyed It shows almost white contrast on the photo. In FIG. 1, the black component (C) having a size of 0.06 to 0.4 μm is dispersed in both the continuous phase and the domain. It is considered that the dispersion of component (C) contributed to the improvement of physical properties such as impact resistance.

  On the other hand, FIG. 2 is a transmission electron microscope image of the resin composition obtained in Comparative Example 3. In FIG. 2, only the polyamide 11 of the gray component (B) is dispersed in a size of 0.1 to 8 μm in the polylactic acid continuous phase of the component (A).

A component A
B component B
C component C

Claims (7)

(A) polylactic acid;
(B) polyamide 11;
Comprises (C) polystyrene emissions epoxy group-containing ethylene copolymer grafted with (C1),
The resin composition in which the component (A) is a continuous phase, and the component (B) and the component (C) are dispersed phases. The mass ratio of the component (A) to the component (B) is 50 to 99 to 50 to 1,
The resin composition of Claim 1 which contains 1-50 mass parts of components (C) with respect to 100 mass parts of total amounts of a component (A) and a component (B). The copolymer of component (C1) is a segment of ethylenically unsaturated carboxylic acid glycidyl ester unit or ethylenically unsaturated hydrocarbon group glycidyl ether unit, a copolymer polystyrene synth segment grafted, copolycondensation The resin composition of Claim 1 whose ratio of the said graft segment of a coalescence is 1-50 mass%.   The resin composition of Claim 1 whose weight average molecular weights measured by GPC of the polylactic acid of the said component (A) are 5,000-1,000,000 (g / mol).   The manufacturing method of the resin composition of Claim 1 including the process of melt-kneading the said component (A), (B) and (C).   An injection-molded article, an extruded molded article, a tubular molded article, a sheet / film molded article, or a fiber comprising the resin composition according to claim 1.   A household electric product, an electric / electronic component, a communication device component, or an automobile component using the molded article according to claim 6.