JP2011084654A - Polylactic acid-based resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition in which a polylactic acid-based resin having high environmental compatibility is used and which has high flexibility, and to provide a molded product made of the same. <P>SOLUTION: The resin composition is obtained by melt-mixing a component (A) and a component (B) below. The component (A) is a polylactic acid-based resin having a melt mass flow rate of 0.000 to 10 g/10min at 230&deg;C and at a load (kgf) of 2.16 kg, as measured according to the test condition 4 of JIS K7210. The component (B) is a thermoplastic elastomer. Thereby, a resin composition having high flexibility is obtained while using a polylactic acid-based resin having high environmental compatibility. A molded product having low hardness, modulus and flexural elastic modulus, and a high tensile elongation, and hardly generating folding wrinkles is obtained by molding the composition. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a polylactic acid resin composition having flexibility and a molded body obtained by molding the same.

  In recent years, interest in oil resource depletion and carbon dioxide emission reduction has increased. Under these circumstances, polylactic acid resins using lactic acid obtained by fermenting plants as a raw material are attracting attention as environmentally friendly materials. Currently, the raw material for lactic acid is edible crops such as corn, but the development of a technology for fermenting and purifying lactic acid from non-edible raw materials is also under development. However, since the polylactic acid-based resin has high rigidity and is brittle, its use in the soft field where a thermoplastic elastomer or the like is used has not progressed.

  It is known that a polylactic acid resin can be softened by adding an ester plasticizer (see Patent Document 1), but a polylactic acid resin that is a linear polymer is a plasticizer holding power. , The plasticizer tends to bleed out. Moreover, when a plasticizer is added, a glass transition temperature will fall and heat resistance will fall. Studies have also been made on softening and impact resistance improvement using acrylic rubber having high affinity with polylactic acid resin (see Patent Document 2), but the effect of softening with acrylic rubber is insufficient, and a large amount Even if it is used, it does not reach the hardness of a thermoplastic elastomer or the like.

  On the other hand, as a technique for improving the impact resistance of a polylactic acid resin, a method in which an organic oxide is added to a mixture of a polylactic acid resin and an ethylene-propylene conjugated diene copolymer and melt kneaded is disclosed. However, this technique is not a technique for softening a polylactic acid resin, but a technique for impact resistance modification of a highly rigid polylactic acid resin. In addition, although it is described here that the two components individually or mutually have a crosslinked structure, even if an organic oxide is added only to the polylactic acid-based resin, it is not crosslinked. It is considered that the conjugated diene copolymers are crosslinked with each other or between the ethylene-propylene conjugated diene copolymer and the polylactic acid resin, and the rigidity of the obtained resin composition is the rigidity of the polylactic acid resin as a matrix. Reflects and seems to remain high.

Japanese Patent No. 3421769 JP 2005-344075 A JP 2002-37987 A

  This invention is made | formed in view of this background art, The subject is providing the resin composition with high flexibility using the polylactic acid-type resin with high environmental adaptability, and its molded object. .

The present inventors have conducted intensive studies in view of the above problems. As a result, it was found that by using a polylactic acid resin having specific physical properties in combination with a thermoplastic elastomer, a highly flexible resin composition can be obtained while using a polylactic acid resin having high environmental adaptability. Was completed.
That is, the gist of the present invention resides in a resin composition obtained by melt-mixing the following component (A) and component (B).

Component (A): Polylactic acid resin having a melt mass flow rate of 0.000 to 10 g / 10 min at 230, 2.16 kg load (kgf) measured according to test condition 4 of JIS standard K7210 Component (B): Thermoplastic elastomer

  According to the present invention, by using a polylactic acid resin having specific physical properties in combination with a thermoplastic elastomer, a highly flexible resin composition can be obtained while using a polylactic acid resin having high environmental adaptability. Then, by molding this, it was possible to obtain a molded body having low hardness, modulus and flexural modulus, high tensile elongation, and hardly generating creases.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following description, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
The resin composition of the present invention comprises a component (A): a polylactic acid system having a melt mass flow rate of 0.000 to 10 g / 10 min at 230 ° C. and 2.16 kg load (kgf) measured in accordance with test condition 4 of JIS standard K7210. Resin and component (B): containing thermoplastic elastomer.
<(Component (A): Polylactic acid resin>
The component (A) contained in the resin composition of the present invention is a polylactic acid resin having specific physical properties.

The component (A) polylactic acid-based resin is a polyester resin containing polylactic acid as a main component. Here, the main component means that polylactic acid is usually contained in the polylactic acid resin in an amount of 50% by weight or more, preferably 75% by weight or more, more preferably 90% by weight or more, and most preferably 95% by weight or more. .
As a component other than polylactic acid contained in the polylactic acid-based resin, homopolymers obtained from organic acids such as aliphatic hydroxycarboxylic acids other than lactic acid, aliphatic dicarboxylic acids, aliphatic diols and aromatic compounds such as terephthalic acid, Copolymers, and mixtures thereof can be mentioned.

  As lactic acid used as a raw material for the polylactic acid-based resin, L-lactic acid, D-lactic acid, DL-lactic acid and / or lactide which is a cyclic dimer of lactic acid can be used. In addition, as the aliphatic hydroxycarboxylic acid other than lactic acid, those having 2 to 10 carbon atoms are preferable. Specifically, for example, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, Examples thereof include 5-hydroxyvaleric acid and 6-hydroxycaproic acid. As the aliphatic dicarboxylic acid, those having 2 to 30 carbon atoms are preferable, and specifically, for example, oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane. Examples include diacid, dodecanedioic acid, phenylsuccinic acid, and 1,4-phenylenediacetic acid. As the aliphatic diol, those having 2 to 30 carbon atoms are preferable. Specifically, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanoyl And 1,4-benzenedimethanol and polytrimethylene ether glycol. Specific examples of the aromatic compound include terephthalic acid, isophthalic acid, and benzoic acid. These raw materials may be used alone or in combination of two or more.

The polylactic acid resin may be a copolymer of the above-mentioned raw organic acid and a small amount of an aliphatic polyhydric alcohol, an aliphatic polybasic acid, or a polyhydric alcohol. Here, examples of the aliphatic polyhydric alcohol include trimethylolpropane and glycerin, examples of the aliphatic polybasic acid include butanetetracarboxylic acid, and examples of the polyhydric alcohol include polysaccharides.
The production method of the polylactic acid-based resin is not particularly limited. For example, a method of directly dehydrating polycondensation of the above-mentioned raw material organic acid, and a cyclic dimer of lactic acid such as lactide or a hydroxycarboxylic acid such as glycolide can be used. Examples include a method of ring-opening polymerization of a cyclic dimer or a cyclic ester intermediate such as ε-caprolactone.

Examples of commercially available products of such polylactic acid resins include “Ingeo” manufactured by NatureWorks, “LACEA” manufactured by Mitsui Chemicals, Inc., “REVODE” manufactured by Zhejiang Kaisho Biomaterials Co., Ltd., and Toyobo Co., Ltd. "Vairo Ecole" made by the company is listed.
The polylactic acid contained in the component (A) polylactic acid resin has a preferred range of melt mass flow rate, which will be described later, and the resin composition of the present invention tends to be flexible, and the molded product of the present invention has hardness, modulus and bending elasticity. Crosslinking is preferred because the ratio is low, the tensile elongation is high, and creases are less likely to occur. Cross-linked polylactic acid can be obtained by imparting molecular chain cross-linking to the above-mentioned polylactic acid. As a form of crosslinking, there are those in which polylactic acids are directly crosslinked and / or those in which polylactic acids are indirectly crosslinked through a crosslinking aid. In the present invention, not only those detected as gel fractions by the gel fraction measurement method, but also cross-linked polylactic acid, including those in which the polylactic acids are in a cross-linked state and the molecular weight of the polylactic acid is increased. And

The method for crosslinking polylactic acid is not particularly limited, and examples thereof include electron beam irradiation and use of a polyfunctional compound. These may be any one method or a combination of two or more methods.
Examples of the polyfunctional compound include a polyvalent isocyanate compound, a polyvalent epoxy compound, and an imine compound. In the case of using a polyfunctional compound, the amount used is preferably larger in terms of crosslinking efficiency, and on the other hand, it is preferably smaller in terms of difficulty in generating fish eyes. Specifically, it is preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, and more preferably 20 parts by weight or less, relative to 100 parts by weight of the polylactic acid resin. It is preferably 10 parts by weight or less.

  Specific examples of polyfunctional compounds include polyfunctional acrylic acid systems such as ethylene glycol diacrylate, butylene glycol diacrylate, triethylene glycol diacrylate, 1,6-hexanediol diacrylate, and tetramethylolmethane tetraacrylate. Compound: ethylene glycol dimethacrylate, butylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate , Trifunctional methacrylic acid compounds such as trimethylolpropane trimethacrylate and tetramethylolmethane tetramethacrylate; divinyl phthalate , Polyvinyl esters of aliphatic and aromatic polycarboxylic acids such as diallyl phthalate, diallyl maleate, bisacryloyloxyethyl terephthalate; polyallyl ester, polyacryloyloxyalkyl ester, polymethacryloyloxyalkyl ester, diethylene glycol divinyl ether, hydroquinone di Polyvinyl ethers and polyallyl ethers of aliphatic and aromatic polyhydric alcohols such as vinyl ether and bisphenol A diallyl ether; Cyanuric acid and isocyanuric acid allyl esters such as triallyl cyanurate and triallyl isocyanurate; Triallyl phosphate, Tris Making maleimides such as acryloxyethyl phosphate, N-phenylmaleimide, N, N'-m-phenylenebismaleimide Compound: Polyfunctional monomers such as dipropargyl phthalate and dipropargyl maleate can be used.

  Of these, polyfunctional methacrylic acid compounds are preferable, and methacrylic acid ester compounds are more preferable from the viewpoint of crosslinking reactivity and the like. The methacrylic acid ester compound is a compound having two or more methacryl groups in the molecule or one or more methacrylic compounds because of its reactivity with the biodegradable resin, low toxicity, residual monomer components after reaction and little coloration. Compounds having a group and one or more glycidyl or vinyl groups are preferred. Preferred methacrylic acid ester compounds include, for example, glycidyl methacrylate, glycidyl acrylate, glycerol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, allyloxy polyethylene glycol monoacrylate, allyloxy polyethylene glycol monomethacrylate, polyethylene glycol dimethacrylate. , Polyethylene glycol diacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, polytetramethylene glycol dimethacrylate; copolymers of alkylene glycols in which these alkylene glycol moieties have different alkylene groups; butanediol methacrylate, butanediol acrylate Etc., and the like.

  It is also suitable to use an organic peroxide in combination with a polyfunctional compound or a crosslinking aid. When the organic peroxide and the polyfunctional compound are used in combination, the cross-linking efficiency is improved by increasing the reaction site with the polyfunctional compound. In polylactic acid crosslinked with an organic peroxide and a crosslinking aid, the polyester component is crosslinked via the crosslinking aid component. Examples of the crosslinking aid include divinylbenzene, diallylbenzene, divinylnaphthalene, divinylphenyl, divinylcarbazole, divinylpyridine, and their nucleus-substituted compounds and related homologues.

  When the crosslinking aid is used, the amount used is preferably larger in terms of the degree of crosslinking, and on the other hand, it is preferably smaller in terms of appearance. Specifically, it is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, and 0.2 parts by weight or more with respect to 100 parts by weight of the polylactic acid resin. Is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and particularly preferably 8 parts by weight or less.

  Examples of organic peroxides include benzoyl peroxide, bis (butylperoxy) trimethylcyclohexane, bis (butylperoxy) cyclododecane, butylbis (butylperoxy) valerate, dicumyl peroxide, butylperoxybenzoate, and dibutyl. Examples thereof include peroxide, bis (butylperoxy) diisopropylbenzene, dimethyldi (butylperoxy) hexane, dimethyldi (butylperoxy) hexyne, and butylperoxycumene.

  In the case of using an organic peroxide, the amount used is preferably larger in terms of crosslinking efficiency, and on the other hand, it is preferably smaller in terms of oligomer component generation. Specifically, it is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the polylactic acid resin. It is preferable that it is 5 parts by weight or less.

  The melt mass flow rate at 230 ° C. and a load of 2.16 kg (hereinafter sometimes abbreviated as MFR) measured according to JIS standard K7210 test condition 4 of the polylactic acid resin of the component (A) is 0.000 g / 10 min or more. 10 g / 10 min or less. Further, from the viewpoint of moldability of the resin composition of the present invention, it is preferably 0.001 g / 10 min or more, more preferably 0.100 g / 10 min or more, and 0.300 g / 10 min or more. On the other hand, it is preferably 5 g / 10 min or less, more preferably 3 g / 10 min or less from the viewpoint of mechanical strength of the molded article of the present invention.

  In addition, MFR in 230 degreeC and a 2.16kg load measured according to the test condition 4 of JIS specification K7210 of the general polylactic acid-type resin which has not performed the crosslinking process is 15-200 g / 10min normally.

<(Component (B): Thermoplastic Elastomer>
The thermoplastic elastomer contained in the resin composition of the present invention refers to an elastomer that exhibits plasticity when heated.
The thermoplastic elastomer of component (B) is a polymer having a duro A hardness of usually 1 or more and 95 or less measured in accordance with JIS standard K6253, and a plurality of polymers as long as the duro A hardness is a resin in this range. These copolymers are also included. However, in a mixture of a plurality of resins, only a resin having a duro A hardness within this range is used as the component (B).

  Examples of thermoplastic elastomers include ethylene / propylene copolymer rubber (EPM), ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), ethylene / butene copolymer rubber (EBM), and ethylene / propylene / butene copolymer rubber. Ethylene elastomer such as styrene / butadiene copolymer rubber, styrene elastomer such as styrene / isoprene copolymer rubber, acrylic elastomer such as methyl methacrylate / butyl acrylate copolymer rubber, polyamide / polyol copolymer, etc. Polyamide elastomers; polyester elastomers such as polyester / polyol copolymers; polyurethane elastomers; polyvinyl chloride elastomers and polybutadiene elastomers. In addition, if it is included in the above-mentioned Duro A hardness range, these elastomer components are modified with an acid anhydride or the like to introduce polar functional groups, and other monomers are grafted onto these elastomer components randomly. Those obtained by block copolymerization and the like are also included in the thermoplastic elastomer of component (B).

  The thermoplastic elastomer of component (B) is preferably a styrenic block copolymer from the viewpoint of heat resistance and flexibility, and comprises a polymer block composed of vinyl aromatic hydrocarbon units and a polymer block composed of conjugated diene units. More preferred is a styrene block copolymer having a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene block represented by the following formula (1) and / or (2) and a hydrogenated derivative thereof (hereinafter referred to as the following): Is sometimes abbreviated as hydrogenated block copolymer), and is preferably a copolymer of a vinyl aromatic hydrocarbon represented by the following formula (1) and / or (2) with a conjugated diene block: Most preferred is a hydrogenated derivative of the polymer.

A- (BA) _m (1)
(AB) _n (2)
(In the formula, A represents a polymer block composed of vinyl aromatic hydrocarbon units, B represents a polymer block composed of conjugated diene units, and m and n represent integers of 1 to 5).
The block copolymer described above may be linear, branched and / or radial.

As the monomeric vinyl aromatic hydrocarbon constituting the polymer block A, styrene or a styrene derivative such as α-methylstyrene is preferable.
The conjugated diene monomer constituting the polymer block of B is preferably butadiene and / or isoprene. When the block copolymer represented by the formula (1) and / or the formula (2) is a hydrogenated block copolymer and the polymer block of B is composed only of butadiene, The 1,2-addition structure is preferably 20 to 70% by weight in order to maintain the properties as an elastomer after hydrogenation.

  m and n are preferably large in the sense of lowering the order-disorder transition temperature, but are preferably small in terms of ease of production and cost. Moreover, when m and n are 0, it does not become a block copolymer. As a block copolymer (including a hydrogenated block copolymer), since it is excellent in rubber elasticity, the block copolymer represented by the formula (2) (including the hydrogenated block copolymer) has a formula ( The block copolymer (including hydrogenated block copolymer) represented by 1) is preferable, and the block copolymer (including hydrogenated block copolymer) represented by the formula (1) in which m is 3 or less. ) Is more preferable, and a block copolymer (including a hydrogenated block copolymer) represented by the formula (1) in which m is 2 or less is particularly preferable.

  The ratio of the “A polymer block” in the block copolymer (including the hydrogenated block copolymer) represented by the formula (1) and / or (2) is the mechanical strength of the thermoplastic elastomer and The larger one is preferable from the viewpoint of the heat-sealing strength, and the smaller one is preferable from the viewpoint of flexibility, profile extrusion moldability, and ease of bleeding out. Specifically, the ratio of the “A polymer block” in the block copolymer (including the hydrogenated block copolymer) of the formula (1) is preferably 10% by weight or more, preferably 15% by weight. More preferably, it is more preferably 20% by weight or more. On the other hand, it is preferably 50% by weight or less, more preferably 45% by weight or less, and 40% by weight or less. Is particularly preferred.

  As a manufacturing method of the above-mentioned block copolymer, any method may be used as long as the above-described structure and physical properties can be obtained. Specifically, for example, it can be obtained by performing block polymerization in an inert solvent using a lithium catalyst or the like by the method described in JP-B-40-23798. The hydrogenation of the block copolymer is described in, for example, JP-B-42-8704, JP-B-43-6636, JP-A-59-133203, and JP-A-60-79005. Can be carried out in an inert solvent in the presence of a hydrogenation catalyst. In this hydrogenation treatment, 50% or more of the olefinic double bonds in the polymer block are preferably hydrogenated, more preferably 80% or more are hydrogenated, and in the polymer block It is preferable that 25% or less of the aromatic unsaturated bond is hydrogenated.

Examples of such commercially available hydrogenated block copolymers include “KRATON-G” manufactured by Shell Chemicals Japan Co., Ltd., “Septon” manufactured by Kuraray Co., Ltd., and “Tuftec” manufactured by Asahi Kasei Corporation.
The amount of the block copolymer represented by formula (1) and / or (2) and / or its hydrogenated block copolymer contained in component (B) is preferably 20% by weight or more. , More preferably 30% by weight or more, particularly preferably 40% by weight or more, and the upper limit is usually 100% by weight.

  Further, as the thermoplastic elastomer other than the block copolymer represented by the formula (1) and / or the formula (2) and / or the hydrogenated block copolymer thereof, methyl methacrylate / n-butyl acrylate copolymer Examples thereof include acrylic elastomers such as coalescence; polyamide elastomers such as polyamide / polyol copolymers; polyester elastomers such as polyester / polyol copolymers; polyurethane elastomers and the like.

  The weight average molecular weight of the thermoplastic elastomer of component (B) is preferably larger in terms of mechanical strength, but smaller in terms of molding appearance and fluidity. Specifically, it is preferably 10,000 or more, more preferably 30,000 or more, and on the other hand, it is preferably 450,000 or less, more preferably 400,000 or less, and 200,000 or less. It is particularly preferable that it is 180,000 or less. Here, the weight average molecular weight is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) under the following conditions.

  In addition, even when the weight average molecular weight of the thermoplastic elastomer of the component (B) is outside the above-mentioned preferable range, for example, the resin composition of the present invention is used for the hydrocarbon rubber of the component (C) described later. When the softener is contained, it can be suitably used. Particularly, the softener for hydrocarbon rubber of component (C) with respect to 100 parts by weight of the thermoplastic elastomer of component (B). Is preferably 100 to 500 parts by weight, more preferably 120 to 500 parts by weight.

(Measurement condition)
Equipment: “150C ALC / GPC” manufactured by Nihon Millipore Corporation
Column: Showa Denko Co., Ltd. “AD80M / S” 3 detectors: FOXBORO infrared spectrophotometer “MIRANIA” measurement Wavelength: 3.42 μm
Solvent: o-dichlorobenzene Temperature: 140 ° C
Flow rate: 1 cm ³ / min Injection amount: 200 microliters Concentration: 2 mg / cm ³
As an antioxidant, 0.2% by weight of 2,6-di-t-butyl-p-phenol was added.

  The Duro A hardness of the thermoplastic elastomer of component (B) is usually 1 or more and 95 or less. The duro A hardness is preferably higher in terms of mechanical strength and lower in terms of flexibility. Specifically, the durometer A hardness measured according to JIS standard K6253 is preferably 10 or more, more preferably 15 or more, and on the other hand, it is preferably 90 or less, and 85 or less. Is more preferable.

  The ratio of the component (A) polylactic acid resin and the component (B) thermoplastic elastomer in the resin composition of the present invention is preferably higher in terms of environmental adaptability, and is more flexible and mechanical. In terms of mechanical strength, it is preferable that the thermoplastic elastomer is large. Specifically, the total amount of the component (A) polylactic acid resin and the component (B) thermoplastic elastomer is 100% by weight, and the component (A) polylactic acid resin is 25% by weight or more. Preferably, it is more preferably 30% by weight or more, and on the other hand, it is preferably 80% by weight or less, and more preferably 70% by weight or less. The thermoplastic elastomer of component (B) is preferably 20% by weight or more, more preferably 30% by weight or more, and on the other hand, it is preferably 75% by weight or less, and 70% by weight or less. More preferably.

<(Component (C): Softener for hydrocarbon rubber>
In the point which improves the fluidity | liquidity of the thermoplastic elastomer of a component (B), it is preferable that the resin composition of this invention contains the softener for hydrocarbon type rubbers.

  The hydrocarbon rubber softener for component (C) is preferably a mineral oil-based or synthetic resin-based softener and more preferably a mineral oil-based softener because of its high affinity for thermoplastic elastomers. Mineral oil softeners are generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, with paraffinic oils in which 50% or more of all carbon atoms are paraffinic hydrocarbons, Those in which about 30 to 45% of all carbon atoms are naphthenic hydrocarbons are called naphthenic oils, and those in which 35% or more of all carbon atoms are aromatic hydrocarbons are called carbon atom aromatic oils. ing. The hydrocarbon rubber softener of component (C) may be any one of the above-mentioned various softeners or a mixture of a plurality of kinds. Among these, since the hue is good, paraffin oil Is preferred. Examples of the synthetic resin softener include polybutene and low molecular weight polybutadiene.

  The kinematic viscosity at 40 ° C. of the hydrocarbon rubber softener is preferably higher in terms of fluidity of the thermoplastic elastomer, but is preferably lower in terms of difficulty of fogging and the like. Specifically, it is preferably 20 centistokes or more, more preferably 50 centistokes or more, and on the other hand, it is preferably 800 centistokes or less, and preferably 600 centistokes or less. Specifically, the flash point (COC method) of the rubber softener is preferably 200 ° C. or higher, more preferably 250 ° C. or higher.

  The amount of the softening agent for hydrocarbon rubber of component (C) relative to the thermoplastic elastomer of component (B) in the resin composition of the present invention is preferably smaller in terms of difficulty of fogging and the like and mechanical strength. Specifically, it is preferably 500 parts by weight or less, more preferably 400 parts by weight or less, and particularly preferably 300 parts by weight or less with respect to 100 parts by weight of the thermoplastic elastomer of component (B). preferable. The lower limit of the rubber softener is 0% by weight.

  The MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 for the mixture of the thermoplastic elastomer of component (B) and the softener for hydrocarbon rubber of component (C) The higher one is preferable in terms of the moldability of the resin composition, but the lower one is preferable in terms of the mechanical strength of the molded article of the present invention. Specifically, it is preferably 15 g / 10 min or more, more preferably 50 g / 10 min or more, particularly preferably 100 g / 10 min or more, and preferably 10,000 g / 10 min or less. It is more preferably 3000 g / 10 min or less, and particularly preferably 1000 g / 10 min or less. Here, the MFR of the mixture of the thermoplastic elastomer of component (B) and the softener for hydrocarbon rubber of component (C) is the thermoplastic elastomer of component (B) and the hydrocarbon of component (C). The mixture with the rubber softener for rubber is compression-molded in a choke shape at 100 ° C., and this is used as the MFR of the one that is directly put into the cylinder.

  Further, the ratio of the MFR component (A) to the MFR of the polylactic acid resin is preferably higher in terms of easily exhibiting the excellent effects of the present invention, but is preferably lower in terms of dispersibility. Specifically, the ratio of the MFR to the polylactic acid resin of the component (A) in the mixture of the thermoplastic elastomer of the following component (B) and the hydrocarbon rubber softener of the component (C) is 15 or more. Preferably, it is 50 or more, more preferably 100 or more, and it is preferably 500000 or less, more preferably 50000 or less. In addition, this ratio is a preferable range when the MFR of the polylactic acid resin is not 0 g / 10 min because of the component (A).

  “MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 of a mixture of the thermoplastic elastomer of component (B) and the softener for hydrocarbon rubber of component (C)” / “component ( MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 for the polylactic acid resin of A) ”.

<(Component (D): Propylene resin>
The resin composition of the present invention preferably contains a propylene-based resin because surface layer peeling or the like hardly occurs in a molded product obtained by molding the resin composition of the present invention.
The propylene-based resin as the component (D) is a polymer having a durometer A hardness of more than 95 measured according to JIS standard K6253. In the present invention, the propylene polymer having a durometer A hardness of 95 or less is classified as a thermoplastic elastomer of component (B).
Component (D) includes propylene homopolymer, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 4-methyl 1-pentene copolymer. And those polymers modified with an acid anhydride to give a polar functional group. The propylene-based resin of component (D) may be any one of the above-mentioned various resins or a mixture of plural kinds.

  The MFR at 230 ° C. and 2.16 kg load measured according to JIS standard K7210 test condition 4 of the propylene-based resin of component (D) is preferably larger in terms of moldability and smaller in terms of mechanical strength. . Specifically, it is preferably 0.01 g / 10 min or more, more preferably 0.1 g / 10 min or more, and preferably 100 g / 10 min or less, and 80 g / 10 min or less. Is more preferable.

  The amount of the propylene-based resin of component (D) in the resin composition of the present invention is larger in terms of blocking and the difficulty of surface layer peeling in a molded product obtained by molding the resin composition of the present invention. However, in terms of surface hardness, a smaller amount is preferable. Specifically, the content of the component (D) in the resin composition of the present invention is preferably 0.1% by weight or more, and on the other hand, preferably 50% by weight or less, 35% by weight. % Or less is more preferable, and 25% by weight or less is particularly preferable. Further, the amount of the propylene-based resin of the component (D) relative to 100 parts by weight of the polylactic acid-based resin of the component (A) is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, 30 It is particularly preferred that the amount is not more than parts by weight. Note that the lower limit amount of the propylene-based resin from the viewpoint of surface hardness is 0% by weight.

  Further, the total amount of the components (B) to (D) with respect to the component (A) in the resin composition of the present invention is preferably smaller in terms of the content of the polylactic acid resin having high environmental adaptability, but is flexible. From the point of view, more is preferable. Specifically, the total amount of components (B) to (D) is preferably 600 parts by weight or less, more preferably 400 parts by weight or less, with respect to 100 parts by weight of component (A). The amount is particularly preferably at most 40 parts by weight, and more preferably at least 50 parts by weight.

  1. A mixture comprising a thermoplastic elastomer as component (B), a softener for hydrocarbon rubber as component (C) and a propylene resin as component (D), measured at 230 ° C. according to test condition 4 of JIS standard K7210; The MFR at a load of 16 kg is preferably higher in terms of molding processability of the resin composition of the present invention, but is preferably lower in terms of mechanical strength of the molded body of the present invention. Specifically, it is preferably 15 g / 10 min or more, more preferably 50 g / 10 min or more, particularly preferably 100 g / 10 min or more, and preferably 10,000 g / 10 min or less. It is more preferably 3000 g / 10 min or less, and particularly preferably 1000 g / 10 min or less. In addition, MFR about the mixture which consists of component (B)-(D) here melt-kneads the mixture which consists of component (B)-(D) using the twin-screw extruder with a preset temperature of 200 degreeC, The value measured for the pelletized material.

  In addition, the ratio of the MFR of the component (A) to the MFR of the polylactic acid-based resin in the mixture composed of the components (B) to (D) is preferably higher in that the excellent effect of the present invention is easily expressed. The lower one is preferable in terms of dispersibility. Specifically, the ratio of the MFR of the mixture of the following components (B) to (D) to the MFR of the polylactic acid resin of the component (A) is preferably 15 or more, and preferably 50 or more. More preferably, it is particularly preferably 100 or more. On the other hand, it is preferably 500,000 or less, more preferably 50000 or less. In addition, this ratio is a preferable range when the MFR of the polylactic acid resin is not 0 g / 10 min because of the component (A).

  “MFR at 230 ° C. under 2.16 kg load measured according to JIS standard K7210 test condition 4 of the mixture of components (B) to (D)” / “Test condition of JIS standard K7210 for polylactic acid resin of component (A)” MFR at 230 ° C. and 2.16 kg load measured according to 4 ”.

<(Component (E): Compatibilizer>
The resin composition of the present invention preferably contains a compatibilizing agent from the viewpoint of improving mechanical strength, elongation and the like.
The compatibilizer of the component (E) has the following “E1 segment” or “E2 segment” and “E3 segment” or “E4 segment” bonded in a block shape, a random shape and / or a graft shape. It is a copolymer. Specifically, there are four combinations of “E1 segment” and “E3 segment”, “E1 segment” and “E4 segment”, “E2 segment” and “E3 segment”, “E2 segment” and “E4 segment”. Can be mentioned.

The compatibilizer of component (E) is a polymer having a durometer A hardness of more than 95 as measured according to JIS standard K6253.
The E1 segment is a segment having reactivity with a carboxyl group or a hydroxyl group. Specifically, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methyl fumaric acid, mesaconic acid, citraconic acid, glutaconic acid and metal salts of these carboxylic acids, maleic Methyl oxyhydrogen, methyl itaconate hydrogen, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, Aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo (2,2,21) -5-heptene-2,3-dicarboxylic acid, endobicyclo- (2,2,1) -5-F Ten-2,3-dicarboxylic acid anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconic acid and 5- Examples include norbornene-2,3-dicarboxylic acid.

  The E2 segment is a segment having an affinity for the polylactic acid resin of component (A). Specifically, for example, polylactic acid, polyglycolic acid, lactic acid / glycolic acid copolymer, cellulose acetate, polyhydroxyalkanoate, polyhydroxybutyrate, polybutylene succinate, polybutylene succinate-adipate modified, polybutylene Examples include succinate / carbonate modification, polybutylene adipate / terephthalate, polymers containing acrylic units, copolymers thereof, and modified products thereof. In addition, the block / random and / or graft copolymer of “E2 segment” and “E3 segment”, “E2 segment” and “E4 segment” containing 50% by weight or more of polylactic acid as E2 segment is component (E) Excluded from

The E3 segment is a segment having an affinity for the propylene resin of component (D). Specifically, for example, propylene homopolymer, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 4-methyl-1-pentene copolymer Examples include coalescence.
The E4 segment is a segment having an affinity for the thermoplastic elastomer of component (B). Specifically, for example, ethylene / propylene copolymer rubber (EPM), ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), ethylene / butene copolymer rubber (EBM), ethylene / propylene / butene copolymer rubber, etc. Ethylene elastomers; styrene elastomers such as styrene / butadiene copolymer rubber and styrene / isoprene copolymer rubber, and polybutadiene.

  The amount of the compatibilizer of component (E) in the resin composition of the present invention is preferably large in terms of improving physical properties, but is preferably small in terms of cost. Specifically, the content of the component (E) in the resin composition of the present invention is preferably 0.1% by weight or more, and on the other hand, preferably 30% by weight or less, 25% by weight. % Or less is more preferable, and 15% by weight or less is particularly preferable. In addition, since the outstanding effect of this invention can be expressed even when there is no compatibilizing agent, the lower limit amount of the compatibilizing agent is usually 0% by weight.

<Other ingredients>
The resin composition of the present invention may contain resins and components other than the above-described components (A) to (E) as long as the effects of the present invention are not significantly hindered.
Examples of the resins other than the components (A) to (E) include elastomers and resins other than the essential components described above. Specifically, for example, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid ester copolymer, etc. Polyethylene resins such as polyethylene and polybutene-1; Polyphenylene ether resins; Polyamide resins such as nylon 66 and nylon 11; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polyoxymethylene Examples thereof include thermoplastic resins such as polyoxymethylene resins such as homopolymers and polyoxymethylene copolymers, and polymethyl methacrylate resins. Some ethylene / vinyl acetate copolymers have a durometer A of 95 or less depending on the copolymerization ratio. In the present invention, these resins are resins other than components (A) to (E). Instead, the thermoplastic elastomer of component (B) is used.

  As optional components other than the components (A) to (E), various heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, crystal nucleating agents, impact modifiers, pigments, lubricants, antistatic agents, difficulty Examples include flame retardants, flame retardant aids, fillers, and the like. In addition, these arbitrary resin and component may use only 1 type, or may use 2 or more types together. Moreover, it is not specifically limited about the method of mixing these resin and components with an essential component.

  Examples of the heat stabilizer and the antioxidant include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and the like. The flame retardants are roughly classified into halogen-based flame retardants and non-halogen-based flame retardants, but in consideration of the environment, non-halogen flame retardants are preferable. Non-halogen flame retardants include phosphorus flame retardants, hydrated metal compounds (aluminum hydroxide and magnesium hydroxide) flame retardants, nitrogen-containing compounds (melamine and guanidine) flame retardants and inorganic compounds (borate and molybdenum) Compound) flame retardant and the like. Crystal nucleating agents are roughly classified into organic crystal nucleating agents and inorganic crystal nucleating agents. Organic crystal nucleating agents include sorbitol compounds and metal salts thereof; benzoic acid and metal salts thereof; phosphate metal salts; rosin compounds; ethylene bisoleic acid amide, methylene bisacrylic acid amide, ethylene bisacrylic acid amide, hexamethylene bis -9,10-dihydroxystearic acid bisamide, p-xylylene bis-9,10-dihydroxystearic acid amide, decanedicarboxylic acid dibenzoyl hydrazide, hexanedicarboxylic acid dibenzoyl hydrazide, 1,4-cyclohexanedicarboxylic acid dicyclohexylamide, 2,6 -Naphthalenedicarboxylic acid dianilide, N, N ', N "-tricyclohexyltrimesic acid amide, trimesic acid tris (t-butylamide), 1,4-cyclohexanedicarboxylic acid dianilide, 2,6-naphth Dicarboxylic acid dicyclohexylamide, N, N′-dibenzoyl-1,4-diaminocyclohexane, N, N′-dicyclohexanecarbonyl-1,5-diaminonaphthalene, ethylenebisstearic acid amide, N, N′-ethylenebis ( Examples thereof include amide compounds such as 12-hydroxystearic acid) amide, octanedicarboxylic acid dibenzoyl hydrazide, etc. Examples of the inorganic crystal nucleating agent include talc, kaolin, etc. The filler includes an organic filler and an inorganic filler. Organic fillers include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, and modified products thereof, and inorganic fillers. , Talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide Um, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, titanium Examples include potassium acid, boron nitride, graphite, and carbon fiber.

  The total amount of components (A) and (B) in the resin composition of the present invention when the resin composition of the present invention contains a resin or component other than components (A) and (B) In view of ease of manifesting the excellent effects of the invention, it is preferably 40% by weight or more, more preferably 45% by weight or more, particularly preferably 55% by weight or more, and 60% by weight or more. Most preferably. In addition, the upper limit here is 100 weight%.

  The total amount of components (A) to (E) in the resin composition of the present invention when the resin composition of the present invention contains resins and components other than components (A) to (E) In view of ease of manifesting the excellent effects of the invention, it is preferably 50% by weight or more, and more preferably 70% by weight or more. The upper limit here is usually 100% by weight.

<Method for Producing Resin Composition of the Present Invention>
The resin composition of the present invention can be obtained by melt-mixing the above-described components. There is no particular limitation on the method of melt mixing. For example, a composition in which each component is uniformly distributed can be obtained by melt-mixing the above-described resins and components simultaneously or in any order. Specifically, for example, the components contained in the resin composition of the present invention may be mixed and heated in an arbitrary order, or may be mixed while melting all the components. A mixture of components may be melt mixed during molding. The mixing conditions are not particularly limited as long as each component is uniformly mixed, but from the viewpoint of productivity, a continuous kneader such as a single screw extruder or a twin screw extruder, a mill roll, a Banbury mixer, a pressure kneader. It is preferable to use a known melt-kneading method such as a batch kneader. The temperature at the time of melt mixing may be any temperature at which the raw material components and the like are in a molten state, but is usually 160 to 250 ° C.

<Physical properties of the resin composition of the present invention>
Since the polylactic acid-based resin and the thermoplastic elastomer are far apart from each other in melting parameter, they are usually incompatible in the molecular region, and the morphology of the complex forms a sea-island structure. In general, it is known that a polymer alloy in which a two-component resin has a sea-island structure has a smaller particle size of an island phase and exhibits better physical properties as the viscosity ratio under tensile shear becomes closer. For this reason, in an incompatible polymer alloy having a large island phase particle size and high interfacial tension, it has been considered as a conventional technique to bring the viscosity ratio between components close to each other. However, in the present invention, surprisingly, although the viscosity ratio between the polylactic acid resin and the thermoplastic elastomer is not close, the softening has succeeded.

  The MFR of the resin composition of the present invention is preferably higher in terms of molding processability of the resin composition of the present invention, but in terms of mechanical strength of a molded product obtained by molding the resin composition of the present invention. The lower one is preferable. Specifically, with respect to the resin composition of the present invention, the MFR at 190 ° C. and a 2.16 kg load measured according to test condition 4 of JIS standard K7210 is preferably 0.1 g / 10 min or more, and preferably 1 g / 10 min or more. Is more preferably 2 g / 10 min or more. On the other hand, it is preferably 300 g / 10 min or less, more preferably 200 g / 10 min or less, and 100 g / 10 min or less. Is particularly preferred. Here, the MFR is measured for a pellet obtained by melt-kneading the raw material components of the resin composition of the present invention using a biaxial kneader at a set temperature of 200 ° C.

<The manufacturing method of the molded object of this invention>
The molded body of the present invention can be obtained by molding the above-described resin composition of the present invention. Here, there is no restriction | limiting in particular about the preparation methods of the molded object of this invention. Specific examples include various molding methods such as injection molding, blow molding, extrusion molding, inflation molding, and vacuum molding after sheet molding, pressure molding, and vacuum / pressure molding. Of these, injection molding and extrusion molding are preferred. The temperature of the cylinder and the die at the time of molding is preferably a high temperature from the viewpoint that appearance failure due to surface deposition of unmelted material is unlikely to occur, and the melting point of the highest melting point component among the components contained in the molten resin It is more preferable that the temperature is higher, particularly preferably 10 ° C. or higher than the melting point of the component having the highest melting point, and most preferably 20 ° C. or higher than the melting point of the component having the highest melting point. On the other hand, the lower one is preferable in that discoloration or deterioration of physical properties due to thermal decomposition of the contained component hardly occurs. Specifically, since the melting point of the component (A) is generally 130 ° C to 170 ° C, it is preferably 150 ° C or higher, more preferably 170 ° C or higher, and 190 ° C or higher. Is particularly preferable. On the other hand, it is preferably 250 ° C. or lower, more preferably 240 ° C. or lower. Further, the mold temperature when performing injection molding is preferably 60 ° C. or less, and more preferably 45 ° C. or less.

<Shape of molded product>
The molded body of the present invention may have any shape as long as it is a molded body obtained by molding the resin composition of the present invention, and in particular, has a shape such as a tube, a film, a sheet, a fin, or a grip. The shape is preferable because flexibility is easily required.
The molded body of the present invention may be a laminate with other layers. In this case, each molded layer may be laminated, or any one of the layers may be molded in advance, and another layer may be laminated thereon, or a laminate may be formed while simultaneously molding a plurality of layers. Good. As a molding method in the case of a laminated body, specifically, for example, two-color co-extrusion molding using a single-screw or twin-screw extruder, two colors for injecting a molten resin into a previously molded layer Examples include molding, laminate molding, and multilayer inflation molding. Examples of the layer to be laminated include polyethylene, polypropylene, ethylene / α-olefin copolymer, and polymethyl methacrylate.

<Physical properties of molded body>
(1) Duro A hardness The molded body of the present invention is preferably flexible. Specifically, the molded article of the present invention preferably has a duro A hardness of 90 or less measured according to JIS standard K6253. In addition, it is preferable that the minimum of the duro A hardness is 20.

(2) Tensile elongation, 100% modulus, 300% modulus The molded article of the present invention preferably has a higher tensile elongation. Moreover, since it is preferable that the molded object of this invention is flexible, the one where the 100% and 300% modulus is low is preferable. Specifically, in accordance with JIS standard K6251, a test piece of No. 3 dumbbell obtained by punching a plate-shaped molded body of 80 mm × 120 mm × 2 mm is pulled by using an autograph at a speed of 500 mm / min to break. The elongation rate (tensile elongation) is preferably 200% or more, more preferably 250% or more. Note that the upper limit of the tensile elongation is preferably 1000%. In this case, the stress (100% modulus) obtained when the elongation rate of 100% is shown is preferably 5 MPa or less, and more preferably 4 MPa or less. Further, the stress (300% modulus) obtained when the elongation rate of 300% is shown is preferably 15 MPa or less, and more preferably 10 MPa or less.

(3) Flexural modulus The flexural modulus is calculated from the stress when a vertical displacement is applied to a molded body obtained by injection molding at a speed of 2 mm / min in accordance with JIS standard K7171, resulting in a displacement of 0.1 to 0.5 mm. Is done. In terms of flexibility of the molded article of the present invention, the flexural modulus is preferably low, specifically, preferably 100 MPa or less, and more preferably 50 MPa or less. In addition, it is preferable that the minimum of a bending elastic modulus is 0.1 MPa.

(4) Difficulty to cause creases Since the molded body of the present invention is flexible, wrinkles due to deformation are less likely to occur. Easiness of wrinkles due to deformation can be evaluated by whether or not wrinkles are generated on the surface when the molded article of the present invention is deformed by 90 degrees in a direction perpendicular to the flow direction during resin molding.

<Application>
The resin composition of the present invention is suitable for a wide range of uses such as a film and a sheet because it has a polylactic acid resin composition layer having high environmental adaptability and is excellent in flexibility and hardly causes creases. It is considered possible. Among these, it is very suitable for applications that require environmental adaptability, such as food packaging films that consume a large amount of food.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.
In the examples and comparative examples of the present invention, the following raw materials were used.
(A) Polylactic acid resin (a-1) Polylactic acid resin “LACEA H-100” manufactured by Mitsui Chemicals, Inc. Purity 100%. The MFR measured at 190 ° C. and a 2.16 kg load (kgf) is 8 g / 10 min. According to the test condition 4 of JIS standard K7210, MFR measured by 230 degreeC and 2.16kg load (kgf) is 50 g / 10min. Non-crosslinked.

  (A-2) Polylactic acid resin “REVODE101” manufactured by Zhejiang Haisheng Biological Materials Co., Ltd. Purity 100%. The MFR measured at 190 ° C. and a 2.16 kg load (kgf) is 5 g / 10 min. According to the test condition 4 of JIS standard K7210, MFR measured by 230 degreeC and the 2.16kg load (kgf) is 20 g / 10min. Non-crosslinked.

(B) Thermoplastic elastomer (B-1) Styrene-ethylene-butylene copolymer “KRATON G1650” manufactured by Shell Chemical Co., Ltd. The duro A hardness measured according to JIS standard K6253 is 78. The measured value of weight average molecular weight is 90,000. Styrene content 30% by weight.
(B-2) Styrene-ethylene-butylene copolymer “KRATON G1641H” manufactured by Shell Chemical Co., Ltd. Duro A hardness measured in accordance with JIS standard K6253 is 66. The measured value of the weight average molecular weight is 220,000. Styrene content 33% by weight.
(B-3) Styrene-ethylene-butylene copolymer “Tuftec H1031” manufactured by Asahi Kasei Chemicals Corporation. The duro A hardness measured according to JIS standard K6253 is 82. Styrene content 30% by weight. MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 is 150 g / 10 min.

(B-4) An imine-modified styrene-ethylene-butylene copolymer “Tuftec N503” manufactured by Asahi Kasei Chemicals Corporation. The duro A hardness measured according to JIS standard K6253 is 79. Styrene content 30% by weight. MFR at 230 ° C. and 2.16 kg load measured in accordance with test condition 4 of JIS standard K7210 is 20 g / 10 min.
(B-5) An imine-modified styrene-butadiene-butylene copolymer “Tuftec MP10” manufactured by Asahi Kasei Chemicals Corporation. The duro A hardness measured in accordance with JIS standard K6253 is 89. Styrene content 30% by weight. MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 is 7 g / 10 min.

(B-6) Kuraray Co., Ltd. methyl methacrylate / n-butyl acrylate copolymer “LA polymer LA2140e”. The duro A hardness measured in accordance with JIS standard K6253 is 32. Catalog value for weight average molecular weight is 80,000. MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 is 500 g / 10 min.
(C) Softener for hydrocarbon rubber Paraffinic process oil “PW-90” manufactured by Idemitsu Kosan Co., Ltd.

(D) Propylene-based resin Block polypropylene “Novatec PP BC06AH” manufactured by Nippon Polypropylene Co., Ltd. MFR at 230 ° C. and 2.16 kg load measured according to test condition 4 of JIS standard K7210 is 60 g / 10 min.

(E) Compatibilizer Glicidyl methacrylate / alkyl methacrylate copolymer “Falpack 75AS” manufactured by NOF Corporation.
(F) Crosslinking aid Glycidyl methacrylate / methyl methacrylate / styrene copolymer “ARFON UG4040” manufactured by Toagosei Co., Ltd.

(G) Additive (G-1) Phenol antioxidant “Irganox 1010” manufactured by Ciba Japan Co., Ltd.
(G-2) Sulfur antioxidant “ADEKA STAB AO-412S” manufactured by ADEKA Corporation.
(G-3) Polyethylene wax “High Wax 210MP” manufactured by Mitsui Chemicals, Inc.
(G-4) Mitsubishi Rayon Co., Ltd. acrylic impact modifier “Metabrene S2001”.

(Production Example 1)
100 parts by weight of the polylactic acid resin (a-1), 3 parts by weight of the crosslinking aid (F), 0.2 parts by weight of the additives (G-1 to 3) and 8.5 parts of the additive (G-4) The mixture to which parts by weight were added was melt-kneaded at a processing temperature of 200 ° C. and discharged using a twin-screw extruder (double-screw extruder “PCM-30” manufactured by Ikegai Co., Ltd., caliber 30 mm, L / D30). The resin composition was cut into pellets and dried using a speed dryer at 60 ° C. for 12 hours under a nitrogen atmosphere to obtain crosslinked polylactic acid resin pellets. About the obtained pellet, MFR measured by 230 degreeC and the 2.16kg load (kgf) according to the test condition 4 of JIS specification K7210 was 0.4 g / 10min.

(Production Example 2)
100 parts by weight of a styrene-ethylene-butylene copolymer (B-1) and 100 parts by weight of a hydrocarbon rubber softener (C) were mixed using a Henschel mixer. For this mixture, the MFR measured at 230 ° C. and a 2.16 kg load (kgf) was 170 g / 10 min in accordance with test condition 4 of JIS standard K7210. The mixture was compression-molded in a chalk shape at 100 ° C., and the MFR was measured by directly feeding the mixture into a cylinder.

(Production Example 3)
100 parts by weight of a styrene-ethylene-butylene copolymer (B-2) and 100 parts by weight of a hydrocarbon rubber softener (C) were mixed using a Henschel mixer. With respect to this mixture, the MFR measured at 230 ° C. and a 2.16 kg load (kgf) was 0.5 g / 10 min in accordance with test condition 4 of JIS standard K7210. The mixture was compression-molded in a choke shape at 100 ° C., and MFR was measured by directly putting it into a cylinder.

[Example 1]
100 parts by weight of the pellets obtained in Production Example 1, 90 parts by weight of the composition obtained in Production Example 2, 5 parts by weight of imine-modified styrene-butadiene-butylene copolymer (B-5), and propylene-based resin (D) 5 After mixing the parts by weight with a Henschel mixer for 1 minute, the mixture was melt-kneaded at a processing temperature of 200 ° C. using a twin screw extruder, the resulting strand was cut, and the speed was reduced to 12 at 55 ° C. under a nitrogen atmosphere. After drying for a period of time, an 80 mm × 120 mm × 2 mm plate was obtained using an injection molding machine (“IS-130t” manufactured by Toshiba Machine Co., Ltd.).

[Example 2]
The raw material ratio of Example 1 was set to 120 parts by weight of the composition obtained in Production Example 2 and 30 parts by weight of the imine-modified styrene-butadiene-butylene copolymer (B-5) with respect to 100 parts by weight of the pellets obtained in Production Example 1. A plate was obtained in the same manner as in Example 1 except that 10 parts by weight and 10 parts by weight of the propylene-based resin (D) were used.

[Example 3]
The raw material ratio of Example 1 is 160 parts by weight of the composition obtained in Production Example 2 with respect to 100 parts by weight of the pellets obtained in Production Example 1, and 30 weights of imine-modified styrene-butadiene-butylene copolymer (B-5). A plate was obtained in the same manner as in Example 1 except that 10 parts by weight and 10 parts by weight of the propylene-based resin (D) were used.

[Example 4]
With respect to the raw material ratio of Example 1, 240 parts by weight of the composition obtained in Production Example 2 and 30 parts by weight of the imine-modified styrene-butadiene-butylene copolymer (B-5) with respect to 100 parts by weight of the pellets obtained in Production Example 1. A plate was obtained in the same manner as in Example 1 except that 10 parts by weight and 10 parts by weight of the propylene-based resin (D) were used.

[Example 5]
With respect to the raw material ratio of Example 1, 240 parts by weight of the composition obtained in Production Example 2 and 10 parts by weight of imine-modified styrene-butadiene-butylene copolymer (B-5) with respect to 100 parts by weight of the pellets obtained in Production Example 1. A plate was obtained in the same manner as in Example 1 except that 10 parts by weight and 10 parts by weight of the propylene-based resin (D) were used.

[Example 6]
The raw material ratio of Example 1 is 240 parts by weight of the composition obtained in Production Example 2 and 10 parts by weight of propylene-based resin (D) with respect to 100 parts by weight of the pellets obtained in Production Example 1, and imine-modified styrene-butadiene- Except for using the butylene copolymer (B-5), 10 parts by weight of the compatibilizer (E) and 5 parts by weight of calcium carbonate as a blocking inhibitor for the compatibilizer, the same as in Example 1, A plate was obtained.

[Example 7]
The raw material ratio of Example 1 was 260 parts by weight of the composition obtained in Production Example 2 with respect to 100 parts by weight of the pellets obtained in Production Example 1, and the imine-modified styrene-butadiene-butylene copolymer (B-5) and A plate was obtained in the same manner as in Example 1 except that the proprene-based resin (D) was not used.

[Example 8]
The raw material ratio of Example 1 was changed to 260 parts by weight of the styrene-ethylene-butylene copolymer (B-3) instead of the composition obtained in Production Example 2 with respect to 100 parts by weight of the pellets obtained in Production Example 1. A plate was obtained in the same manner as in Example 1 except that the imine-modified styrene-butadiene-butylene copolymer (B-5) and the propylene resin (D) were not used.

[Example 9]
The raw material ratio of Example 1 was changed to the composition obtained in Production Example 2 with respect to 100 parts by weight of the pellets obtained in Production Example 1, and methyl methacrylate / n-butyl acrylate copolymer (B-6) was used. A plate was obtained in the same manner as in Example 1 except that the content was 70 parts by weight and the imine-modified styrene-butadiene-butylene copolymer (B-5) and the proprene-based resin (D) were not used.

[Comparative Example 1]
In Example 4, polylactic acid resin (a-2) was used instead of the pellet obtained in Production Example 1, and the composition obtained in Production Example 3 was used instead of the composition obtained in Production Example 2. In the same manner as in Example 4, a plate was obtained.

[Comparative Example 2]
In Example 4, a plate was obtained in the same manner as in Example 4 except that the polylactic acid resin (a-2) was used instead of the pellets obtained in Production Example 1.

[Comparative Example 3]
In Example 3, a plate was obtained in the same manner as in Example 4 except that the polylactic acid resin (a-2) was used instead of the pellets obtained in Production Example 1.

[Comparative Example 4]
In Example 7, the polylactic acid resin (a-2) was used instead of the pellets obtained in Production Example 1, and the styrene-ethylene-butylene copolymer (B-4) was used instead of the composition obtained in Production Example 2. A plate was obtained in the same manner as in Example 7 except that each was used.

[Comparative Example 5]
In Example 9, a plate was obtained in the same manner as in Example 9 except that the polylactic acid resin (a-2) was used instead of the pellets obtained in Production Example 1.
The molded bodies obtained in Examples and Comparative Examples were evaluated for the following conditions: duro A hardness, tensile elongation, 100% modulus, 300% modulus, flexural modulus, and crease susceptibility. These results are shown in Table 1.

(1) Duro A hardness Duro A hardness was measured in accordance with JIS standard K6253 by stacking three plates obtained in each Example or Comparative Example. In addition, about the thing with high duro A hardness, three plates obtained by each Example or the comparative example were piled up, and duro D hardness was also measured according to JIS specification K6253.

(2) Tensile elongation, 100% modulus, 300% modulus A test piece of No. 3 dumbbell obtained by punching the plate obtained in each example or comparative example was measured according to JIS standard K6251. Specifically, it was pulled at a speed of 500 mm / min using an autograph, and the elongation until it broke was defined as the tensile elongation. Here, the stress obtained when the elongation rate of 100% or 300% was shown was 100% modulus or 300% modulus, respectively.

(3) Flexural modulus The flexural modulus is obtained by applying a vertical displacement at a speed of 2 mm / min to the plate obtained in each example or comparative example according to JIS standard K7171, and displacing by 0.1 to 0.5 mm. It was calculated from the stress.

(4) Easiness of occurrence of creases Easiness of occurrence of creases occurs when the plate obtained in each example or comparative example is deformed by 90 degrees in the direction perpendicular to the flow direction during resin molding. Evaluation was made based on whether wrinkles occurred on the surface.
In addition, MFR in 190 degreeC or 230 degreeC and a 2.16 kg load (kgf) of the resin composition of the Example was measured according to the test condition 4 of JIS specification K7210.
The following points became clear from the comparison between the examples and the comparative examples.
When the thermoplastic elastomer is styrene (Examples 1 to 8 and Comparative Examples 1 to 4 ), Examples 3 and 4 comprising the polylactic acid resin and the styrene thermoplastic elastomer according to the present invention, and these Compared with Comparative Examples 3 and 2 that differ only in that the MFR of the polylactic acid resin is high, Example 4 has lower hardness, 100% and 300% modulus, and higher tensile elongation than Comparative Example 2, Excellent flexibility and no creases. In addition, Example 3 was lower in hardness and flexural modulus than in Comparative Example 3, was excellent in flexibility, had a very high tensile elongation, and was not easily creased.

Further, comparing Example 4 with Comparative Example 1 in which the type of thermoplastic elastomer is different from Example 4, compared with Comparative Example 1 in which the thermoplastic elastomer is a low molecular weight polymer, the thermoplastic elastomer is more Example 4, which has a low molecular weight and a high fluidity, had very low hardness, 100% modulus and flexural modulus, and was particularly excellent in flexibility.
Similarly, when Example 8 is compared with Comparative Example 4 in which the type of thermoplastic elastomer is different from Example 8, Example 8 has a lower hardness than Comparative Example 4, and is 100% modulus and 300% modulus. In addition, the flexural modulus was very low, the tensile elongation was high, and the flexibility was excellent.

  In Examples 1 to 5, the polylactic acid resin and the amount of other components are different, but all have hardness, 100% and 300% moduli, low flexural modulus, excellent flexibility, and tensile elongation. It was high and it was difficult for folds to occur. In particular, Example 6 containing a compatibilizing agent has an extremely low 300% modulus compared to Examples 4 and 5 in which the amount ratio of the polylactic acid resin and the other components is about the same. It was found that the containing system is superior in flexibility when loaded. Moreover, the excellent softness | flexibility was fully expressed also in Example 7 which does not contain a propylene-type resin.

In the case where the thermoplastic elastomer is acrylic (Example 9 and Comparative Example 5), Example 9 composed of the polylactic acid resin according to the present invention and the acrylic thermoplastic elastomer, and these are the polylactic acid resin. When compared with Comparative Example 5 that differs only in that the MFR is high, Example 9 has a very low hardness and flexural modulus compared to Comparative Example 5, and creases are less likely to occur.
From the above results, the resin composition of the present invention has high flexibility while using a polylactic acid-based resin having high environmental adaptability, and the molded product obtained by molding the resin has hardness, modulus, and flexural modulus. The tensile elongation rate was high, and it was revealed that creases are unlikely to occur.

Claims (11)

A resin composition obtained by melt-mixing the following component (A) and component (B).
Component (A): Polylactic acid resin having a melt mass flow rate of 0.000 to 10 g / 10 min at 230 ° C. and a load of 2.16 kg (kgf) measured according to test condition 4 of JIS standard K7210 Component (B): Thermoplastic Elastomer   2. The resin composition according to claim 1, wherein the component (A) is a polylactic acid based on a total amount of 100% by weight of the component (A) polylactic acid resin and the component (B) thermoplastic elastomer. Resin composition is 25-80 weight%, The thermoplastic elastomer of the said component (B) is 20-75 weight%, The resin composition characterized by the above-mentioned.   3. The resin composition according to claim 1, wherein the first component (A) polylactic acid resin is a crosslinked polylactic acid resin.   The resin composition according to any one of claims 1 to 3, wherein the thermoplastic elastomer of the component (B) is a styrenic block copolymer.   5. The resin composition according to claim 4, wherein the styrenic block copolymer is a block copolymer having a polymer block comprising a vinyl aromatic hydrocarbon unit and a polymer block comprising a conjugated diene unit. The resin composition characterized by the above-mentioned.   The resin composition according to any one of claims 1 to 5, further comprising a component (C) a hydrocarbon-based rubber softener.   The resin composition according to any one of claims 1 to 6, further comprising a component (D) a propylene-based resin. The resin composition according to any one of claims 1 to 7, further comprising the following component (E):
Component (E): a copolymer in which the following “E1 segment” or “E2 segment” and “E3 segment” or “E4 segment” are bonded in a block shape, a random shape and / or a graft shape. E1 segment: segment having reactivity to carboxyl group or hydroxyl group E2 segment: segment having affinity for polylactic acid-based resin of component (A) E3 Segment: Segment having affinity for propylene resin of component (D) E4 Segment: Segment having affinity for thermoplastic elastomer of component (B)   The resin composition according to any one of claims 1 to 8, wherein the thermoplastic elastomer of the component (B) has a weight average molecular weight of 10,000 to 200,000.   It is a resin composition in any one of Claims 6 thru | or 9, Comprising: About the melt mass flow rate in 230 degreeC and a 2.16 kg load (kgf) measured according to the test condition 4 of JIS specification K7210, the said component (B) A value obtained by dividing the melt mass flow rate of the mixture of the thermoplastic elastomer and the hydrocarbon rubber softener of component (C) by the melt mass flow rate of the polylactic acid resin of component (A) is 15 or more. A resin composition.   The molded object obtained by shape | molding the resin composition in any one of Claims 1 thru | or 10.