Crystal nucleating agent for polylactic acid resin, polylactic acid resin composition, and polylactic acid resin molded body

Abstract

The present invention provides a dispersion-type nucleating agent for polylactic acid-based resins, the nucleating agent being capable of increasing the temperature of crystallization of a polylactic acid-based resin composition and improving the heat resistance of a polylactic acid-based resin molded article when the nucleating agent is used in a polylactic acid-based resin. The present invention also provides a polylactic acid-based resin composition and a polylactic acid-based resin molded article in each of which the nucleating agent for polylactic acid-based resins is used. The nucleating agent for polylactic acid-based resins comprises a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is a cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent that is directly bound to a cyclohexane ring, the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt or a dilithium salt, and the molar ratio of a cis-isomer in stereoisomers of the alkyl substituent bound through the cyclohexane ring in the alicyclic dicarboxylic acid and an oxycarbonyl group constituting the metal salt is 80.0% or more.

Description

[Technical Field]

[0001] The present invention relates to a crystal nucleating agent for polylactic acid resin, a polylactic acid resin composition, and a polylactic acid resin molded article. [Background technology]

[0002] Polylactic acid resin is an environmentally friendly material that has the property of eventually decomposing into water and carbon dioxide by the presence of moisture and microorganisms in the environment. For this reason, attempts are being made in various fields to put it to practical use as an alternative material to petroleum-derived resins.

[0003] However, polylactic acid resins have a slower crystallization rate than petroleum-derived resins, which means that processing such as molding takes time, resulting in poor industrial productivity. To address this issue, methods have been investigated that involve using a crystal nucleating agent to shorten the crystallization time of polylactic acid resins.

[0004] For example, Patent Document 1 discloses a technique of using an amide compound having a specific structure as a crystal nucleating agent for polylactic acid-based resins.

[0005] For example, Patent Document 2 discloses a technique in which talc having a specific D50 average particle size is used as a crystal nucleating agent for polylactic acid-based resins. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-6654 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-105302 Summary of the Invention [Problem to be solved by the invention]

[0007] The nucleating agent described in Patent Document 1 is a soluble nucleating agent, so when kneading it with a polylactic acid resin, the kneading temperature must be raised to the limit temperature of the polylactic acid resin (240°C), which can lead to the problem of decomposition of the polylactic acid resin.

[0008] The crystal nucleating agent (talc) described in Patent Document 2 has problems such as insufficient crystallization promotion effect (increase in crystallization temperature) and insufficient heat resistance of the resulting polylactic acid resin molded article.

[0009] Therefore, an object of the present invention is to provide a dispersion-type crystal nucleating agent for polylactic acid-based resins, which, when used in polylactic acid-based resins, can improve the crystallization temperature of polylactic acid-based resin compositions and the heat resistance of polylactic acid-based resin molded articles. The present invention also provides a polylactic acid resin composition using the above-mentioned crystal nucleating agent for polylactic acid resin, and a polylactic acid resin molded article. [Means for solving the problem]

[0010] As a result of extensive research, the present inventors have found that the crystallization temperature of a polylactic acid resin composition and the heat resistance of a polylactic acid resin molded article can be improved by using as a crystal nucleating agent a metal salt of an alicyclic dicarboxylic acid in which the alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the metal salt is a calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt, and the molar ratio of cis isomers between the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt is within a specific range. Furthermore, the inventors have discovered that metal salts of alicyclic dicarboxylic acids are dispersion-type nucleating agents that have excellent dispersibility in polylactic acid-based resins, and do not need to be kneaded at the limit temperature of the polylactic acid-based resin as is the case with soluble nucleating agents, and therefore can suppress decomposition of the polylactic acid-based resin, thereby completing the present invention.

[0011] That is, the present invention provides a crystal nucleating agent for polylactic acid-based resins, which comprises a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, and the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt, and wherein, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 80.0% or more.

[0012] In the polylactic acid resin crystal nucleating agent of the present invention, the alkyl substituent is preferably a linear or branched alkyl group having 1 to 4 carbon atoms. In the polylactic acid resin crystal nucleating agent of the present invention, the alkyl substituent is preferably a methyl group or a tert-butyl group. In addition, in the crystal nucleating agent for polylactic acid resins of the present invention, the position of the alkyl substituent is preferably the 3rd or 4th position of the cyclohexane ring. In the crystal nucleating agent for polylactic acid resin of the present invention, the metal salt is preferably a calcium salt or a disodium salt. Furthermore, it is preferable that the crystal nucleating agent for polylactic acid-based resins of the present invention has a molar ratio of cis isomers of stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt of 90.0% or more.

[0013] The present invention also relates to a polylactic acid resin composition containing the above-mentioned crystal nucleating agent for polylactic acid resins and a polylactic acid resin. In the polylactic acid resin composition of the present invention, the content of the crystal nucleating agent for polylactic acid resin is preferably 0.03 to 10 parts by mass relative to 100 parts by mass of the polylactic acid resin.

[0014] The present invention also relates to a polylactic acid resin molded article made from the polylactic acid resin composition. [Effects of the Invention]

[0015] The present invention provides a dispersion-type crystal nucleating agent for polylactic acid-based resins, which, when used in polylactic acid-based resins, can improve the crystallization temperature of polylactic acid-based resin compositions and the heat resistance of polylactic acid-based resin molded articles. The present invention also provides a polylactic acid resin composition using the above-mentioned crystal nucleating agent for polylactic acid resin, and a polylactic acid resin molded article. DETAILED DESCRIPTION OF THE INVENTION

[0016] <Crystal nucleating agent for polylactic acid resin> The polylactic acid-based resin nucleating agent of the present invention is a polylactic acid-based resin nucleating agent containing a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt, and among the stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 80.0% or more.

[0017] (Metal salts of alicyclic dicarboxylic acids) The crystal nucleating agent for polylactic acid resin of the present invention contains a metal salt of an alicyclic dicarboxylic acid. The metal salt of the alicyclic dicarboxylic acid is a dispersion-type nucleating agent, and therefore has excellent dispersibility in the polylactic acid resin. Therefore, unlike a dissolution-type nucleating agent, it does not need to be kneaded at the limit temperature of the polylactic acid resin, and decomposition of the polylactic acid resin can be suppressed.

[0018] The alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent attached directly to the cyclohexane ring.

[0019] The alkyl substituent is preferably a linear or branched alkyl group having 1 to 4 carbon atoms. Specific examples of the alkyl substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, from the viewpoint of suitably improving the crystallization temperature of the polylactic acid resin composition and the heat resistance of the polylactic acid resin molded article, a methyl group or a tert-butyl group is preferred, and a methyl group is more preferred.

[0020] The position of the alkyl substituent is preferably the 3rd or 4th position of the cyclohexane ring, more preferably the 4th position of the cyclohexane ring, from the viewpoint of suitably improving the crystallization temperature of the polylactic acid resin composition and the heat resistance of the polylactic acid resin molded article. The position of the alkyl substituent can be appropriately selected depending on the type of metal species that forms a metal salt with the substituted alkyl substituent.

[0021] The metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt. Among these, calcium salts or disodium salts are preferred, and calcium salts are more preferred, from the viewpoint of suitably improving the crystallization temperature of the polylactic acid resin composition and the heat resistance of the polylactic acid resin molded article.

[0022] Specific examples of the metal salt of an alicyclic dicarboxylic acid of the present invention include the disodium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the hydroxyaluminum salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the dilithium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the disodium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, and the hydrochloride salt of 3-ethylcyclohexane-1,2-dicarboxylic acid. hydroxyaluminum salt, dilithium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid Calcium salt, hydroxyaluminum salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, 3-tert-butylcyclohexane-1,2-dicarboxylic acid disodium salt of 3-tert-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-tert-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-tert-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-tert-butylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-isobutylcyclohexane-1,Dilithium salt of 2-dicarboxylic acid, disodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid aluminum salt, dilithium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid salt, hydroxyaluminum salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid disodium salt, calcium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, 4-isobutylcyclohexane-1,Examples include dilithium salts of 2-dicarboxylic acids, and among these, preferred embodiments include disodium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, and calcium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid.

[0023] The crystal nucleating agent for polylactic acid resins of the present invention has a molar ratio of cis isomers of stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt of 80.0% or more. When the molar ratio of the cis isomer is 80.0% or more, the crystallization temperature of the polylactic acid resin composition and the heat resistance of the polylactic acid resin molded article can be improved.

[0024] From the viewpoint of suitably improving the crystallization temperature of the polylactic acid resin composition and the heat resistance of the polylactic acid resin molded body, the nucleating agent for polylactic acid resin of the present invention preferably has a molar ratio of the cis isomer of 83.0% or more, more preferably 85.0% or more, even more preferably 90.0% or more, even more preferably 93.0% or more, particularly preferably 95.0% or more, and most preferably 99.0% or more.

[0025] In addition, among the stereoisomers of the alkyl substituents via the cyclohexane ring of the above-mentioned alicyclic dicarboxylic acid and the oxycarbonyl groups constituting the metal salt, the cis isomer means that the alkyl substituents on the cyclohexane ring and the two oxycarbonyl groups constituting the metal salt all point in the same direction.

[0026] As an example of a method for measuring the molar ratio of the cis isomer, stereoisomers of an alicyclic dicarboxylic acid or a derivative thereof are measured by gas chromatography (GC), the area ratio of each peak is calculated by the area percentage method, and the molar ratio can be determined by [(area ratio of cis isomer) / (area ratio of cis isomer+area ratio of trans isomer)]×100. In the case of a metal salt of an alicyclic dicarboxylic acid, the molar ratio of cis isomers among stereoisomers does not change before and after the step of reacting the alicyclic dicarboxylic acid or a derivative thereof with a metal oxide, metal hydroxide, or metal chloride. The fact that the molar ratio of cis isomers in stereoisomers does not change before and after the step of reacting an alicyclic dicarboxylic acid or a derivative thereof with a metal oxide, metal hydroxide, or metal chloride can be confirmed by comparing the results of measuring the molar ratio of cis isomers in the metal salt of alicyclic dicarboxylic acid obtained by the above method with the results of similarly measuring the molar ratio after converting the obtained metal salt of alicyclic dicarboxylic acid back into an acid anhydride.

[0027] The compounds corresponding to the respective retention times in the GC can be identified as the above-mentioned alicyclic dicarboxylic acids or derivatives thereof, and as cis isomers or trans isomers, by measuring them with nuclear magnetic resonance spectroscopy (NMR) and infrared spectroscopy (IR).

[0028] For example, in the NMR of 4-methylcyclohexane-1,2-dicarboxylic anhydride, the isomeric structure can be identified from the nuclear Overhauser effect (NOE) of the methine hydrogen at the alkyl group substitution site on the cyclohexane ring, which is present at around 1.4 ppm in the obtained 2D NMR spectrum, and the methine hydrogen at the base of the acid anhydride, which is present at around 3.2 ppm.The peak where NOE is observed can be assigned to the cis isomer, and the peak where NOE is not observed can be assigned to the trans isomer.

[0029] After the step of reacting the alicyclic dicarboxylic acid or a derivative thereof with a metal oxide, metal hydroxide, or metal chloride, IR and inductively coupled plasma analysis (ICP) are performed to identify the element-specific spectrum and measure its emission intensity, thereby confirming that the desired metal salt of the alicyclic dicarboxylic acid has been obtained.

[0030] The above GC, NMR, IR and ICP can be suitably measured, for example, under the conditions described in the Examples below.

[0031] Considering that the particle shape of the polylactic acid resin crystal nucleating agent of the present invention is a dispersed type crystal nucleating agent, the smaller the particles are, as long as their dispersibility in the polylactic acid resin is not deteriorated by secondary aggregation, the larger the contact surface with the polylactic acid resin, and the more likely it is that a smaller amount will be able to exhibit better performance as a crystal nucleating agent. Therefore, the average particle size determined by laser diffraction particle size distribution measurement is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 20 μm or less, and particularly preferably 10 μm or less. From the viewpoint of dispersibility, the average particle size determined by laser diffraction particle size distribution measurement is preferably 0.01 μm or more, more preferably 0.1 μm or more, and even more preferably 0.5 μm or more.

[0032] (Method for producing metal salts of alicyclic dicarboxylic acids) The alicyclic dicarboxylic acid can be easily produced, for example, by hydrogenating 4-cyclohexene-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent, obtained by the Diels-Alder method or the like, to obtain cyclohexane-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent, and then converting the resulting cyclohexane-1,2-dicarboxylic anhydride into a metal salt. One preferred example will be specifically described below.

[0033] Step 1: A conjugated diene compound having 5 to 8 carbon atoms is reacted with maleic anhydride or a derivative thereof to obtain 4-cyclohexene-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent. Step 2: The alkyl-substituted 4-cyclohexene-1,2-dicarboxylic anhydride or a derivative thereof obtained in Step 1 is hydrogenated to obtain alkyl-substituted cyclohexane-1,2-dicarboxylic anhydride or a derivative thereof. Step 3: The alkyl-substituted cyclohexane-1,2-dicarboxylic anhydride or its derivative obtained in Step 2 is reacted with a metal oxide, metal hydroxide, or metal chloride to obtain the metal salt of cyclohexane-1,2-dicarboxylic acid having an alkyl substituent of the present invention.

[0034] The method for producing the metal salt of an alicyclic dicarboxylic acid preferably includes the steps 1 to 3 described above. That is, the method includes Step 1 of reacting a conjugated diene compound having 5 to 8 carbon atoms with maleic anhydride or a derivative thereof to obtain 4-cyclohexene-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent; Step 2 of hydrogenating the 4-cyclohexene-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent obtained in Step 1 to obtain cyclohexane-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent; and Step 3 of reacting the cyclohexane-1,2-dicarboxylic anhydride or a derivative thereof having an alkyl substituent obtained in Step 2 with a metal oxide, metal hydroxide, or metal chloride to obtain a metal salt of cyclohexane-1,2-dicarboxylic acid having an alkyl substituent.

[0035] Examples of the conjugated diene compound having 5 to 8 carbon atoms include 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene, 2-propyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-tert-butyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene (piperylene), 1,3-hexadiene, 2,4-hexadiene, 2,4-heptadiene, 2,4-octadiene, 3-methyl-1,3-pentadiene, and 2,5-dimethyl-2,4-hexadiene.

[0036] The metal oxides, metal hydroxides, or metal chlorides include oxides, hydroxides, or chlorides of metal species such as calcium, aluminum, sodium, and lithium.

[0037] The method of reacting a conjugated diene compound having 5 to 8 carbon atoms with maleic anhydride or a derivative thereof in the above step 1, the method of hydrogenating 4-cyclohexene-1,2-dicarboxylic anhydride having an alkyl substituent or a derivative thereof in the above step 2, and the method of obtaining a metal salt of cyclohexane-1,2-dicarboxylic acid having an alkyl substituent in the above step 3 are not particularly limited, and any known method can be appropriately selected and used.

[0038] <Polylactic acid resin composition> The polylactic acid resin composition of the present invention contains the crystal nucleating agent for polylactic acid resin of the present invention and a polylactic acid resin.

[0039] From the viewpoint of suitably increasing the crystallization temperature of the polylactic acid resin composition of the present invention, the content of the nucleating agent for polylactic acid resin is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the polylactic acid resin.

[0040] Furthermore, from the viewpoint of suitably improving the heat resistance of polylactic acid resin molded articles, the polylactic acid resin composition of the present invention preferably contains the nucleating agent for polylactic acid resin in an amount of 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 0.2 parts by mass or more, per 100 parts by mass of the polylactic acid resin. When the content of the polylactic acid resin nucleating agent is 0.2 parts by mass or more per 100 parts by mass of the polylactic acid resin, the heat resistance of the polylactic acid resin molded article can be particularly suitably improved.

[0041] Furthermore, in the polylactic acid resin composition of the present invention, the content of the polylactic acid resin nucleating agent is preferably 10 parts by mass or less per 100 parts by mass of the polylactic acid resin. When the content of the polylactic acid resin nucleating agent is 10 parts by mass or less per 100 parts by mass of the polylactic acid resin, the occurrence of white spots in the polylactic acid resin molded article described below can be suppressed.

[0042] (Polylactic acid resin) The polylactic acid resin has lactic acid units of various optical purities, and is composed of, for example, structural units consisting of L-lactic acid residues (L-lactic acid units), structural units consisting of D-lactic acid residues (D-lactic acid units), etc. The polylactic acid resin according to the present invention can be one obtained by a known production method or a commercially available product.

[0043] Specific examples of the polylactic acid resin include polylactic acid resins mainly composed of L-lactic acid units, polylactic acid resins mainly composed of D-lactic acid units, mixtures (stereocomplexes) of polylactic acid resins mainly composed of L-lactic acid units and polylactic acid resins mainly composed of D-lactic acid units, and polylactic acid resins in which L-lactic acid units and D-lactic acid units are randomly or block polymerized. Among these, polylactic acid resins mainly composed of L-lactic acid units and / or polylactic acid resins mainly composed of D-lactic acid units are preferred, and polylactic acid resins mainly composed of L-lactic acid units or polylactic acid resins mainly composed of D-lactic acid units are more preferred.

[0044] The above-mentioned "mainly composed of" means that the ratio of either one of the lactic acid units is preferably 80 to 100 mol %, more preferably 90 to 100 mol %, and even more preferably 95 to 100 mol %, relative to all structural units constituting the polylactic acid-based resin. By setting the content within this range, the melting point of the polylactic acid resin becomes high, making it easier to obtain a polylactic acid resin molded product with good heat resistance and mechanical properties, and also making it possible to further shorten the crystallization time of the polylactic acid resin molded product.

[0045] The above-mentioned "total structural units constituting the polylactic acid-based resin" means the combined units of L-lactic acid units and D-lactic acid units when the polylactic acid-based resin is composed only of structural units derived from lactic acid (lactic acid residues), and means the combined units of structural units derived from lactic acid and structural units derived from hydroxycarboxylic acids other than lactic acid, as described below.

[0046] Polylactic acid-based resins can be obtained according to known production methods using L-lactic acid, D-lactic acid, DL-lactic acid, L-lactide, D-lactide, meso-lactide, or a mixture thereof as a starting material, by a direct dehydration condensation method of lactic acid or a lactide ring-opening method.

[0047] From the viewpoint of the ease of obtaining starting materials, starting materials are not limited to plant-derived starting materials, and lactic acid derivatives such as L-methyl lactate, D-methyl lactate, L-ethyl lactate, D-ethyl lactate, and those produced by microorganisms can also be used as starting materials (monomers).

[0048] The polylactic acid resin may contain structural units other than lactic acid residues, preferably at a ratio of 20 mol % or less, more preferably 10 mol % or less, and even more preferably 5 mol % or less, of the total structural units constituting the polylactic acid resin.

[0049] Examples of the other structural units include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; aliphatic glycols such as ethylene glycol, propylene glycol, and 1,4-butanediol; and hydroxycarboxylic acids such as glycolic acid, β-hydroxybutyric acid, hydroxypivalic acid, and hydroxyvaleric acid.

[0050] The molecular weight of the polylactic acid resin is not particularly limited, but the number average molecular weight is preferably in the range of 5,000 to 400,000, and more preferably in the range of 10,000 to 200,000. If the molecular weight of the polylactic acid resin falls within the above range, the polylactic acid resin molded article will be superior in terms of mechanical properties, hydrolysis resistance, and moldability. In this specification, the number average molecular weight is a value calculated as polystyrene measured by GPC (gel permeation chromatography).

[0051] (others) The polylactic acid resin composition of the present invention may contain additives as needed.

[0052] Examples of the additives include hydrolysis resistance improvers (end-capping agents), lubricants, plasticizers, pigments, impact resistance modifiers, processing aids, reinforcing agents, colorants, flame retardants, weather resistance modifiers, ultraviolet absorbers, antioxidants, mildew inhibitors, antibacterial agents, light stabilizers, antistatic agents, silicone oils, antiblocking agents, mold release agents, foaming agents, fragrances, various fibers such as glass fibers and polyester fibers, fillers such as wood flour, and coupling agents.

[0053] When the above-mentioned additives are blended, their content is appropriately selected depending on their type and purpose, but for example, it is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the polylactic acid-based resin.

[0054] (crystallization temperature) The polylactic acid resin composition of the present invention preferably has a crystallization temperature of 126°C or higher, more preferably 129°C or higher, and even more preferably 132°C or higher. If the crystallization temperature is within the above range, it can be determined that the crystallization temperature of the polylactic acid resin composition has been improved by the polylactic acid resin crystal nucleating agent. The crystallization temperature is determined by, for example, preparing a polylactic acid resin composition by the method described below, measuring it by differential scanning calorimetry under the measurement conditions described below, and determining the temperature at the top of the detected peak.

[0055] <Preparation of polylactic acid resin composition> A predetermined amount of a nucleating agent for polylactic acid resin is added to 100 parts by mass of polylactic acid resin (TE-2000, manufactured by Unitika Ltd., or 4032D, manufactured by Natureworks Inc.), and the mixture is dry-blended in a Henschel mixer to obtain a mixture. The above mixture is melt-kneaded in a twin-screw extruder (nozzle die inner diameter: φ3 mm) at a resin temperature of 185°C, extruded into strands in water (25°C), cooled, and cut with a pelletizer to produce a polylactic acid-based resin composition. The crystallization temperature is measured under the following measurement conditions. <Measurement conditions> Measurement device: Product name: DSC8500 (manufactured by PerkinElmer) Measurement started at 200°C, finished at 50°C, and cooled at a rate of 10°C / min (based on JIS K 7121:2012 "Method for measuring transition temperature of plastics"). Approximately 6 mg of polylactic acid resin composition sample was dried in a vacuum dryer at 80°C and 0.1 kPa for 12 hours or more.

[0056] <Polylactic acid resin molded body> The polylactic acid resin molded article of the present invention is made from the polylactic acid resin composition of the present invention.

[0057] The polylactic acid resin molded article of the present invention can be produced, for example, by the following method. The polylactic acid resin molded article of the present invention can be obtained by molding according to a commonly used molding method. The molding method is not particularly limited as long as it achieves the effects of the present invention, and any of the conventionally known molding methods such as injection molding, extrusion molding, blow molding, pressure molding, rotational molding, and film molding can be used.

[0058] (Heat resistance) The polylactic acid resin molded article of the present invention has excellent heat resistance. The heat resistance can be evaluated, for example, by preparing a polylactic acid resin molded article under the following conditions, measuring the dynamic viscoelasticity under the following measurement conditions, and determining the storage modulus E' at 80°C. The storage modulus E' at 80°C is preferably 100 MPa or more, more preferably 150 MPa or more, even more preferably 200 MPa or more, even more preferably 250 MPa or more, particularly preferably 300 MPa or more, particularly more preferably 350 MPa or more, and most preferably 400 MPa or more.

[0059] <Method for measuring storage modulus of polylactic acid resin molded body> A polylactic acid resin composition is prepared in the same manner as in the measurement of the crystallization temperature. The polylactic acid resin composition is dried in a vacuum dryer at 110° C. and 0.1 kPa for 12 hours or more, and then melted in a press at a resin temperature of 200° C. and 10 MPa for 2 minutes. Thereafter, the mixture is annealed at 130°C for 1 minute and then rapidly cooled at 25°C to prepare a polylactic acid resin molded body. The storage modulus E' at 80°C is measured under the following measurement conditions. <Measurement conditions> Measuring device: Product name: Rheogel-E4000 (manufactured by UBM Co., Ltd.) Measurement mode: tension, frequency: 10Hz, measurement start temperature: 30℃, heating rate: 2℃ / min

[0060] (exterior) The polylactic acid resin molded article of the present invention preferably has excellent appearance. A polylactic acid resin molded article is prepared in the same manner as in the measurement of heat resistance, and the polylactic acid resin molded article is visually observed to count the number of white spots. If there are no white spots (0 spots) on the polylactic acid resin molded article, it can be determined that the appearance is excellent.

[0061] The present specification discloses the following: The present disclosure (1) is a crystal nucleating agent for polylactic acid-based resins, comprising a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, and the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt, and among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 80.0% or more. The present disclosure (2) is the crystal nucleating agent for polylactic acid resins according to the present disclosure (1), wherein the alkyl substituent is a linear or branched alkyl group having 1 to 4 carbon atoms. The present disclosure (3) is the crystal nucleating agent for polylactic acid resins according to the present disclosure (2), in which the alkyl substituent is a methyl group or a tert-butyl group. The present disclosure (4) is a crystal nucleating agent for polylactic acid resins according to any one of the present disclosures (1) to (3), wherein the alkyl substituent is at the 3rd or 4th position of the cyclohexane ring. The present disclosure (5) is the crystal nucleating agent for polylactic acid resins according to any one of the present disclosures (1) to (4), wherein the metal salt is a calcium salt or a disodium salt. The present disclosure (6) is a crystal nucleating agent for polylactic acid-based resins according to any one of the present disclosures (1) to (5), in which, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 90.0% or more. The present disclosure (7) is a polylactic acid resin composition containing the crystal nucleating agent for polylactic acid resin according to any one of the present disclosures (1) to (6) and a polylactic acid resin. The present disclosure (8) is the polylactic acid-based resin composition according to the present disclosure (7), wherein the content of the nucleating agent for polylactic acid-based resin is 0.03 to 10 parts by mass per 100 parts by mass of the polylactic acid-based resin. The present disclosure (9) is a polylactic acid resin molded article made of the polylactic acid resin composition according to the present disclosure (7) or (8). [Example]

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The methods for measuring the various properties in the examples are as follows. Reagents were used for compounds not specifically mentioned.

[0063] [Compound used] Maleic anhydride (Tokyo Chemical Industry Co., Ltd.) Isoprene (Tokyo Chemical Industry Co., Ltd.) Piperylene (Tokyo Chemical Industry Co., Ltd.) 1-Cyclohexene-1,2-dicarboxylic anhydride (Tokyo Chemical Industry Co., Ltd.) · Palladium catalyst (manufactured by Tokyo Chemical Industry Co., Ltd.) · Polylactic acid resin: "TE-2000" (manufactured by Unitika Ltd.) · Polylactic acid resin: "4032D" (manufactured by NatureWorks LLC) · Talc "Micro Ace P-3" (manufactured by Nippon Talc Co., Ltd.) · Crystal nucleating agent: Tricyclohexylammonium trimesate (manufactured by Shin Nippon Rika Co., Ltd.)

[0064] [Analysis method for metal salts of alicyclic dicarboxylic acids] (1) Gas chromatography analysis (GC) In the examples and the like, the molar ratio of the cis isomer in the stereoisomers of the alkyl substituent at the 3-position or 4-position via the cyclohexane ring of the alicyclic dicarboxylic acid or its derivative and the oxycarbonyl group forming the metal salt was measured by GC. Thereafter, the area ratio of each peak was calculated by the area percentage method, and the molar ratio of the alkyl substituent at the 3-position or 4-position via the cyclohexane ring in the metal salt of the alicyclic dicarboxylic acid and the cis isomer in the stereoisomers of the oxycarbonyl group constituting the metal salt was determined by [(area ratio of cis isomer) / (area ratio of cis isomer + area ratio of trans isomer)]×100. It should be noted that the fact that the molar ratio of the cis isomer in the above stereoisomers did not change before and after the step of reacting the alicyclic dicarboxylic acid or its derivative with the metal oxide, metal hydroxide or metal chloride was confirmed by comparison with the result of performing the same measurement after returning the obtained metal salt of the alicyclic dicarboxylic acid to the acid anhydride. Also, the fact that the compound corresponding to each retention time is the alicyclic dicarboxylic acid or its derivative, and that it is the cis isomer and trans isomer thereof was confirmed by the following NMR and IR.

[0065] <GC measurement conditions> Model: Gas chromatograph GC-2010 (manufactured by Shimadzu Corporation) Detector: FID, 280 °C Column: DB-1701 (30 m × 0.25 mm φ × 0.25 μm) Column temperature: 145℃ Injection temperature: 280℃ Carrier gas: Helium (linear velocity: 30 cm / sec) Injection volume: 0.1 μl (split ratio: 1 / 15)

[0066] (2) Nuclear magnetic resonance spectroscopy (NMR) The structure of each isomer in the GC analysis was confirmed by NMR under the following NMR measurement conditions: NMR analyzer: Product name "DRX-500", manufactured by Bruker Solvent: deuterated dimethyl sulfoxide (DMSO-d6) Internal standard: tetramethylsilane (TMS) Sample tube: 5 mm 1 H-NMR: Resonance frequency: 500.1 MHz, 4 times of accumulation 13 C-NMR: Resonance frequency: 125.8 MHz, number of accumulations: 23 The measurement sample was prepared by diluting 30 mg of the sample with 0.8 ml of solvent.

[0067] (3) Infrared spectroscopy (IR) The structures of the isomers in the GC analysis and the metal salts of the alicyclic dicarboxylic acids obtained in the examples were confirmed by IR. The IR measurement conditions are as follows: FT-IR device: product name "Spectrum One", manufactured by PerkinElmer, Measurement method: ATR method Number of times accumulated: 3 times Resolution: 4.00cm -1 The measurement was performed by pressing the sample onto the cell of the device.

[0068] (4) Inductively Coupled Plasma Analysis (ICP) The structures of the metal salts of alicyclic dicarboxylic acids obtained in the examples were confirmed by ICP. The ICP measurement conditions are as follows: ICP device: product name "iCAP 6500Duo", manufactured by Thermo Fisher Scientific, Spray chamber: Cyclone atomizer Plasma conditions: Plasma / Auxiliary / Carrier = 15 / 1.0 / 0.6 Plasma observation direction: axial direction 3 times The samples for measurement were prepared by pretreatment using microwave decomposition. Microwave device: Product name "Multiwave PRO", manufactured by Anton Paar Decomposition conditions: Approximately 0.05 g of sample and 6 mL of nitric acid (special grade) were decomposed, and then diluted with distilled water.

[0069] [Method for evaluating polylactic acid resin compositions] (5) Crystallization temperature The polylactic acid-based resin compositions obtained in the examples were measured using a differential scanning calorimeter (DSC8500, manufactured by PerkinElmer) at a starting temperature of 200°C, an ending temperature of 50°C, and a cooling rate of 10°C / min (in accordance with JIS K 7121:2012 "Method for measuring transition temperature of plastics"). The temperature at the top of the detected peak was taken as the crystallization temperature (°C), and was evaluated according to the following criteria. For measuring the crystallization temperature, about 6 mg of a sample was used that had been dried in a vacuum dryer at 80° C. and 0.1 kPa for 12 hours or more. (Evaluation criteria) ◎: Crystallization temperature is 129℃ or higher 〇: Crystallization temperature is 126℃ or higher but less than 129℃ △: Crystallization temperature is 123℃ or higher but lower than 126℃ ×: Crystallization temperature not detected or crystallization temperature is less than 123°C

[0070] [Evaluation method for polylactic acid resin molded products] (6) Heat resistance The polylactic acid resin molded articles obtained in the examples were measured for their storage modulus E' at 80°C using a measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) under the following conditions: measurement mode: tension, frequency: 10 Hz, measurement starting temperature: 30°C, and heating rate: 2°C / min. The values ​​were evaluated according to the following criteria. (Evaluation criteria) ◎: Storage modulus E' at 80℃ is 200MPa or more ○: Storage modulus E' at 80℃ is 100MPa or more and less than 200MPa △: Storage modulus E' at 80°C is 10 MPa or more and less than 100 MPa ×: Storage modulus E' at 80°C is less than 10 MPa

[0071] (7) Appearance The polylactic acid resin molded articles obtained in the examples were visually observed, the number of white spots was counted, and the results were evaluated according to the following criteria. 〇: No white spots observed (0 white spots) ×: White spots were observed (one or more white spots)

[0072] Example 1 <Preparation of crystal nucleating agent for polylactic acid resin> A pressure-resistant autoclave was charged with 196 g of maleic anhydride, 500 ppm of p-tert-butylcatechol as a radical polymerization inhibitor, and 500 ppm of diphenyl sulfide as a polymerization inhibitor. The mixture was heated to 50-55°C and melted. The system was then purged with nitrogen gas containing 0.06% oxygen by volume under stirring. 140 g of isoprene (a conjugated diene compound) was then added continuously over 6 hours at 50-55°C, followed by a Diels-Alder reaction at 70°C for 1 hour. After completion of the reaction, the mixture was distilled at 85°C under atmospheric pressure and then under reduced pressure to remove volatile components, yielding 332 g of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride.

[0073] Next, 200 g of the 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride obtained above and 0.4 g of a palladium catalyst (palladium 5% / alumina 95%) were placed in a pressure-resistant autoclave, and a hydrogenation reaction was carried out under a hydrogen pressure of 1 MPa at a temperature of 110°C for 5 hours with stirring. After the reaction was completed, the reaction mixture was separated from the catalyst by centrifugation to obtain 197 g of 4-methylcyclohexane-1,2-dicarboxylic anhydride. GC and NMR analyses confirmed that the molar ratio of the cis isomer in the resulting 4-methylcyclohexane-1,2-dicarboxylic anhydride was 85.0%. The 4-methylcyclohexane-1,2-dicarboxylic anhydride was then distilled under reduced pressure at 120°C to separate the low-boiling fraction and the subsequent fraction. Two-dimensional NMR spectroscopy confirmed that the low-boiling fraction was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of 99.5% cis isomer. In the obtained 2D NMR spectrum, the methine hydrogen of the alkyl group substituted on the cyclohexane ring, which is present at around 1.4 ppm, and the methine hydrogen of the base of the acid anhydride, which is present at around 3.2 ppm, were assigned as the peak of the cis isomer when NOE was observed, and the peak of the trans isomer when NOE was not observed.

[0074] Next, 500 ml of water and 61 g (0.81 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and a thermometer, and the mixture was stirred at room temperature to form a slurry. 136 g (0.81 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, and the mixture was heated to 50°C and stirred for 5 hours to carry out the reaction. After completion of the reaction, the slurry was filtered, washed with a sufficient amount of water, and then dried under reduced pressure at 140°C overnight to obtain 168 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt. IR and ICP confirmed that the structure of the obtained compound 1 (calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid with a molar ratio of cis isomer of 99.5%) was the structure of the target compound.

[0075] <Preparation of polylactic acid resin composition> 0.03 parts by mass of a nucleating agent for polylactic acid resins (Compound 1) was added to 100 parts by mass of polylactic acid resin (TE-2000, manufactured by Unitika Ltd.), and the mixture was dry-blended in a Henschel mixer to obtain a mixture. The above mixture was melt-kneaded in a twin-screw extruder (nozzle die inner diameter: φ3 mm) at a resin temperature of 185°C, extruded into water (25°C) in the form of strands, cooled, and cut with a pelletizer to produce a polylactic acid-based resin composition. The polylactic acid resin composition was used to evaluate the crystallization temperature by the above-mentioned method.

[0076] <Preparation of polylactic acid resin molded body> The polylactic acid resin composition was dried in a vacuum dryer at 110° C. and 0.1 kPa for 12 hours or more, and then melted in a press at a resin temperature of 200° C. and 10 MPa for 2 minutes. Thereafter, the mixture was annealed at 130°C for 1 minute, and then rapidly cooled in a mold whose temperature was controlled at 25°C to produce a polylactic acid resin molded body. The heat resistance and appearance of the polylactic acid resin molded article were evaluated by the above-mentioned methods.

[0077] Examples 2 to 10 <Preparation of crystal nucleating agent for polylactic acid resin> In the same manner as in Example 1, Compound 1 (calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid with a molar ratio of cis isomer of 99.5%) was prepared. <Preparation of polylactic acid resin composition> A polylactic acid resin composition was prepared in the same manner as in Example 1, except that a nucleating agent for polylactic acid resin (Compound 1) was added in the amount shown in Table 1 to 100 parts by mass of polylactic acid resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0078] Example 11 <Preparation of crystal nucleating agent for polylactic acid resin> 200 g of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride obtained in Example 1 and 0.4 g of a palladium catalyst (palladium 5% / alumina 95%) were placed in a pressure-resistant autoclave, and a hydrogenation reaction was carried out under a hydrogen pressure of 1 MPa at a temperature of 110°C for 5 hours with stirring. Thermal isomerization was carried out at 170°C to obtain 197 g of 4-methylcyclohexane-1,2-dicarboxylic anhydride. GC and NMR confirmed that the molar ratio of cis isomer in the obtained 4-methylcyclohexane-1,2-dicarboxylic anhydride was 50.0%. Subsequently, the 4-methylcyclohexane-1,2-dicarboxylic anhydride having a molar ratio of cis isomer of 50.0% obtained above was mixed with the 4-methylcyclohexane-1,2-dicarboxylic anhydride having a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride having a molar ratio of cis isomer of 95.0%.

[0079] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 2). IR and ICP confirmed that the structure of the resulting compound 2 was the structure of the target compound.

[0080] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 2) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0081] Example 12 <Preparation of crystal nucleating agent for polylactic acid resin> 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 50.0% obtained in Example 11 was mixed with 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 93.0%.

[0082] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 3). IR and ICP confirmed that the structure of the resulting compound 3 was the structure of the target compound.

[0083] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 3) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0084] Example 13 <Preparation of crystal nucleating agent for polylactic acid resin> 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 50.0% obtained in Example 11 was mixed with 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 90.0%.

[0085] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 4). IR and ICP confirmed that the structure of the resulting compound 4 was the structure of the target compound.

[0086] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 4) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0087] Example 14 <Preparation of crystal nucleating agent for polylactic acid resin> 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 50.0% obtained in Example 11 was mixed with 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 83.0%.

[0088] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 5). IR and ICP confirmed that the structure of the resulting compound 5 was the structure of the target compound.

[0089] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 5) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0090] Example 15 <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 1) was added to 100 parts by mass of polylactic acid-based resin ("4032D", manufactured by NatureWorks). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0091] (Comparative Example 1) <Preparation of polylactic acid resin composition> A polylactic acid resin composition was prepared in the same manner as in Example 1, except that no crystal nucleating agent for polylactic acid resin was added to the polylactic acid resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0092] (Comparative Example 2) <Preparation of crystal nucleating agent for polylactic acid resin> 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 50.0% obtained in Example 11 was mixed with 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 75.0%.

[0093] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 6). IR and ICP confirmed that the structure of the resulting compound 6 was the structure of the target compound.

[0094] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 6) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0095] (Comparative Example 3) <Preparation of crystal nucleating agent for polylactic acid resin> 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 50.0% obtained in Example 11 was mixed with 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 99.5% obtained in Example 1. Two-dimensional NMR spectroscopy confirmed that the resulting mixture was 4-methylcyclohexane-1,2-dicarboxylic anhydride with a molar ratio of cis isomer of 70.0%.

[0096] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 7). IR and ICP confirmed that the structure of the resulting compound 7 was the structure of the target compound.

[0097] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 7) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0098] Comparative Example 4 <Preparation of crystal nucleating agent for polylactic acid resin> In the same manner as in Example 11, 4-methylcyclohexane-1,2-dicarboxylic anhydride having a molar ratio of cis isomer of 50.0% was prepared.

[0099] Next, 50 ml of water and 6.1 g (0.08 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 13.6 g (0.08 mol) of 4-methylcyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 15.9 g of 4-methylcyclohexane-1,2-dicarboxylic acid calcium salt (compound 8). IR and ICP confirmed that the structure of the resulting compound 8 was the structure of the target compound.

[0100] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 8) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0101] (Comparative Example 5) <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 1 part by mass of a nucleating agent (talc, Microace P-3, manufactured by Nippon Talc Co., Ltd.) was added to 100 parts by mass of a polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0102] (Comparative Example 6) <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.2 parts by mass of trimesic acid tricyclohexylamide was added to 100 parts by mass of a polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0103] (Comparative Example 7) <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.03 parts by mass of trimesic acid tricyclohexylamide was added to 100 parts by mass of a polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0104] (Comparative Example 8) <Preparation of crystal nucleating agent for polylactic acid resin> A pressure-resistant autoclave was charged with 196 g of maleic anhydride, 500 ppm of p-tert-butylcatechol as a radical polymerization inhibitor, and 500 ppm of diphenyl sulfide as a polymerization inhibitor. The mixture was heated to 50-55°C and melted. The system was then purged with nitrogen gas containing 0.06% oxygen by volume under stirring. Next, 108 g of butadiene (a conjugated diene compound) was added continuously over 6 hours at 70-75°C, followed by a Diels-Alder reaction at 90°C for 1 hour. After the reaction was complete, the volatile components were removed by distillation at 85°C under atmospheric pressure and then under reduced pressure, yielding 304 g of 4-cyclohexene-1,2-dicarboxylic anhydride.

[0105] Next, 200 g of the 4-cyclohexene-1,2-dicarboxylic anhydride obtained above and 0.4 g of a palladium catalyst (palladium 5% / alumina 95%) were placed in a pressure-resistant autoclave, and a hydrogenation reaction was carried out for 5 hours with stirring at a hydrogen pressure of 1 MPa and a temperature of 110°C. After the reaction was completed, the reaction product was separated from the catalyst by centrifugation to obtain 197 g of cyclohexane-1,2-dicarboxylic anhydride.

[0106] Next, 500 ml of water and 61 g (0.81 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 125 g (0.81 mol) of the cyclohexane-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 120 g of cyclohexane-1,2-dicarboxylic acid calcium salt (compound 9). IR and ICP confirmed that the structure of the resulting compound 9 was the structure of the target compound.

[0107] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 9) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0108] (Comparative Example 9) <Preparation of crystal nucleating agent for polylactic acid resin> A four-neck flask equipped with a stirrer and thermometer was charged with 500 ml of water and 61 g (0.81 mol) of calcium hydroxide, and the mixture was stirred at room temperature to form a slurry. To the resulting slurry, 123 g (0.81 mol) of 4-cyclohexene-1,2-dicarboxylic anhydride obtained in Comparative Example 8 was added, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and then dried under reduced pressure at 140°C overnight to obtain 156 g of 4-cyclohexene-1,2-dicarboxylic acid calcium salt (compound 10). IR and ICP confirmed that the structure of the resulting compound 10 was the structure of the target compound.

[0109] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 10) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0110] (Comparative Example 10) <Preparation of crystal nucleating agent for polylactic acid resin> A four-neck flask equipped with a stirrer and thermometer was charged with 500 ml of water and 61 g (0.81 mol) of calcium hydroxide, and the mixture was stirred at room temperature to form a slurry. To the resulting slurry, 134 g (0.81 mol) of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride obtained in Example 1 was added, heated to 50°C, and stirred for 5 hours to carry out the reaction. After completion of the reaction, the slurry was filtered, washed with a sufficient amount of water, and then dried under reduced pressure at 140°C overnight to obtain 166 g of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid calcium salt (compound 11). IR and ICP confirmed that the structure of the resulting compound 11 was the structure of the target compound.

[0111] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (compound 11) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0112] (Comparative Example 11) <Preparation of crystal nucleating agent for polylactic acid resin> A four-neck flask equipped with a stirrer and thermometer was charged with 500 ml of water and 61 g (0.81 mol) of calcium hydroxide, and the mixture was stirred at room temperature to form a slurry. 123 g (0.81 mol) of 1-cyclohexene-1,2-dicarboxylic anhydride was added to the resulting slurry, which was then heated to 50°C and stirred for 5 hours to carry out the reaction. After the reaction was complete, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 156 g of 1-cyclohexene-1,2-dicarboxylic acid calcium salt (compound 12). IR and ICP confirmed that the structure of the resulting compound 12 was that of the target compound.

[0113] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (Compound 12) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0114] (Comparative Example 12) <Preparation of crystal nucleating agent for polylactic acid resin> A pressure-resistant autoclave was charged with 196 g of maleic anhydride, 500 ppm of p-tert-butylcatechol as a radical polymerization inhibitor, and 500 ppm of diphenyl sulfide as a polymerization inhibitor. The mixture was heated to 50-55°C and melted. The system was then purged with nitrogen gas containing 0.06% oxygen by volume under stirring. Next, 140 g of piperylene (a conjugated diene compound) was added continuously over 6 hours at 50-55°C, followed by a Diels-Alder reaction at 70°C for 1 hour. After the reaction was complete, the volatile components were removed by distillation at 85°C under atmospheric pressure and then under reduced pressure, yielding 332 g of 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride.

[0115] Next, 500 ml of water and 61 g (0.81 mol) of calcium hydroxide were charged into a four-neck flask equipped with a stirrer and thermometer and stirred at room temperature to form a slurry. 134 g (0.81 mol) of the 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride obtained above was added to the resulting slurry, heated to 50°C, and stirred for 5 hours to carry out the reaction. After the reaction was completed, the slurry was filtered, washed with a sufficient amount of water, and dried under reduced pressure at 140°C overnight to obtain 166 g of 3-methyl-4-cyclohexene-1,2-dicarboxylic acid calcium salt (compound 13). IR and ICP confirmed that the structure of the resulting compound 13 was the structure of the target compound.

[0116] <Preparation of polylactic acid resin composition> A polylactic acid-based resin composition was prepared in the same manner as in Example 1, except that 0.3 parts by mass of a nucleating agent for polylactic acid-based resins (compound 13) was added to 100 parts by mass of polylactic acid-based resin (TE-2000, manufactured by Unitika Ltd.). The crystallization temperature of the polylactic acid resin composition was evaluated by the above method. <Preparation of polylactic acid resin molded body> A polylactic acid resin molded article was produced in the same manner as in Example 1 except that the above polylactic acid resin composition was used, and the heat resistance and appearance were evaluated by the above methods.

[0117] The evaluation results of the above Examples and Comparative Examples are shown in Tables 1 to 3. In Tables 1 to 3, "nucleating agent for polylactic acid resins" is abbreviated simply to "nucleating agent," "the molar ratio of cis isomers among the stereoisomers of the alkyl substituents via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt" is abbreviated simply to "molar ratio of cis isomers," and "the amount of nucleating agent for polylactic acid resins added per 100 parts by mass of polylactic acid resin" is abbreviated simply to "amount of nucleating agent added."

[0118] [Table 1]

[0119] [Table 2]

[0120] [Table 3]

[0121] From the above examples, it was confirmed that the use of the nucleating agent for polylactic acid-based resins of the present invention in polylactic acid-based resins can improve the crystallization temperature of the polylactic acid-based resin composition and the heat resistance of the polylactic acid-based resin molded body. Furthermore, it was confirmed from Examples 5 and 11 to 14 that the higher the molar ratio of the cis isomer in the nucleating agent for polylactic acid-based resins, the more favorably the crystallization temperature of the polylactic acid-based resin composition and the heat resistance of the polylactic acid-based resin molded body can be improved. Furthermore, it was confirmed from Examples 1 to 10 that the heat resistance of polylactic acid resin molded bodies can be significantly improved by adding 0.2 parts by mass or more of the nucleating agent for polylactic acid resin per 100 parts by mass of polylactic acid resin. On the other hand, when the nucleating agent of the comparative example was used in a polylactic acid-based resin, it was not possible to sufficiently improve the crystallization temperature of the polylactic acid-based resin composition and the heat resistance of the polylactic acid-based resin molded body. [Industrial Applicability]

[0122] The present invention provides a dispersion-type crystal nucleating agent for polylactic acid-based resins, which, when used in polylactic acid-based resins, can improve the crystallization temperature of polylactic acid-based resin compositions and the heat resistance of polylactic acid-based resin molded articles. The present invention also provides a polylactic acid resin composition using the above-mentioned crystal nucleating agent for polylactic acid resin, and a polylactic acid resin molded article. The polylactic acid resin molded article of the present invention has excellent heat resistance and can be used in products intended for use at high temperatures.

Claims

1. A crystal nucleating agent for polylactic acid resins, comprising a metal salt of an alicyclic dicarboxylic acid, the alicyclic dicarboxylic acid is cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly attached to the cyclohexane ring; the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt; A crystal nucleating agent for polylactic acid-based resins, wherein, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 80.0% or more.

2. 2. The polylactic acid resin crystal nucleating agent according to claim 1, wherein the alkyl substituent is a linear or branched alkyl group having 1 to 4 carbon atoms.

3. 3. The polylactic acid resin crystal nucleating agent according to claim 2, wherein the alkyl substituent is a methyl group or a tert-butyl group.

4. 3. The crystal nucleating agent for polylactic acid resins according to claim 1, wherein the alkyl substituent is at the 3rd or 4th position of the cyclohexane ring.

5. 3. The crystal nucleating agent for polylactic acid resins according to claim 1, wherein the metal salt is a calcium salt or a disodium salt.

6. 3. The crystal nucleating agent for polylactic acid-based resins according to claim 1 or 2, wherein, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 90.0% or more.

7. A polylactic acid resin composition comprising the crystal nucleating agent for polylactic acid resins according to claim 1 or 2 and a polylactic acid resin.

8. 8. The polylactic acid resin composition according to claim 7, wherein the content of the nucleating agent for polylactic acid resin is 0.03 to 10 parts by mass per 100 parts by mass of the polylactic acid resin.

9. A polylactic acid resin molded article made from the polylactic acid resin composition according to claim 7.

Images