JP2019111766A - Polylactic acid resin composition laminated sheet - Google Patents

Abstract

To provide a polylactic acid resin composition laminated sheet excellent in transparency and storage stability, and a method for producing the laminated sheet.SOLUTION: A polylactic acid resin composition laminated sheet containing a plurality of polylactic resin composition layers includes at least the layer P and layer Q, in which the layer P is a layer of a polylactic resin composition containing (P-A) a polylactic resin, (P-B) a plasticizer and (P-C) an organic crystal nucleating agent, the layer Q is a layer of a polylactic resin composition containing (Q-A) a polylactic resin and (Q-C) an organic crystal nucleating agent, a content of the (Q-C) the organic crystal nucleating agent in the layer is more than 0.3 mass% and 1.0 mass% or less, when (Q-B) the plasticizer is contained in the layer Q, a content of (P-B) the plasticizer in the layer P is larger than a content of (Q-B) the plasticizer in the layer Q, and at least one outermost layer of the surface side and the rear face side of the sheet is the layer P.SELECTED DRAWING: None

Description

  The present invention relates to a polylactic acid resin composition laminated sheet. More specifically, the present invention relates to a polylactic acid resin composition laminated sheet which can be suitably used for molded articles such as daily necessities, cosmetics, and packs and trays of household electric appliances etc., and a method for producing the sheet.

  Polylactic acid resin is expected to be used because its raw material is derived from plants and carbon dioxide emissions are extremely small, etc. However, it is expected that lamination will be performed due to its characteristics such as high rigidity and high transparency as the resin characteristics. A technology to provide functionality by means of

  For example, Patent Document 1 discloses a layer P containing a plasticizer, and a layer Q having a smaller content of plasticizer than the layer P, as a polylactic acid resin composition lamination sheet which achieves high impact resistance and transparency. A polylactic acid resin composition laminated sheet is proposed.

JP 2017-24407 A

  However, in the polylactic acid resin composition laminated sheet of Patent Document 1, the transparency was sometimes deteriorated during storage, and it was found that further improvement is necessary.

  The present invention relates to a polylactic acid resin composition laminate sheet excellent in transparency and storage stability, and a method for producing the laminate sheet.

The present invention relates to the following [1] to [2].
[1] It is a polylactic acid resin composition lamination sheet containing layers of a plurality of polylactic acid resin compositions, and is a polylactic acid resin composition lamination sheet containing at least the following layer P and layer Q,
The layer P is a layer of a polylactic acid resin composition containing (P-A) polylactic acid resin, (P-B) plasticizer, and (P-C) organic crystal nucleating agent,
Layer Q is a layer of a polylactic acid resin composition containing (Q-A) polylactic acid resin and (Q-C) organic crystal nucleating agent, and containing (Q-C) organic crystal nucleating agent in the layer The amount is more than 0.3% by mass and not more than 1.0% by mass,
Here, in the case where the layer Q further contains a (Q-B) plasticizer, the content of the (P-B) plasticizer in the layer P is the same as that of the (Q-B) plasticizer in the layer Q. Polylactic acid resin composition lamination sheet whose content is more than content and at least one outermost layer of the surface side and back side of a sheet is layer P.
[2] A method for producing a polylactic acid resin composition laminate sheet including a plurality of layers of a polylactic acid resin composition, which comprises the following steps (1), (2) and (3): Sheet manufacturing method.
Process (1): The polylactic acid resin which comprises layer P by melt-kneading the raw material containing (P-A) polylactic resin, (P-B) plasticizer, and (PC) organic crystal nucleating agent Step (2) of Preparing a Composition: Polylactic Acid Resin Composition Comprising Layer Q by Melt-kneading a Raw Material Containing (Q-A) Polylactic Acid Resin, and (Q-C) Organic Crystal Nucleating Agent A step of preparing the organic crystalline nucleating agent in the layer in an amount of more than 0.3% by mass and not more than 1.0% by mass,
Here, in the case where the layer Q further contains a (Q-B) plasticizer, the content of the (P-B) plasticizer in the layer P is the same as that of the (Q-B) plasticizer in the layer Q. Process step (3) having a content greater than the content: layer P is a sheet of the polylactic acid resin composition of layer P obtained in step (1) and the polylactic acid resin composition of layer Q obtained in step (2) Melt coextrusion to be the outermost layer of at least one of the front and back sides of

  ADVANTAGE OF THE INVENTION According to this invention, the polylactic acid resin composition lamination sheet which is excellent in transparency and storage stability, and the manufacturing method of this lamination sheet can be provided.

  The polylactic acid resin composition laminate sheet of the present invention is a laminate of at least two layers of a polylactic acid resin composition containing a polylactic acid resin, a plasticizer, and an organic crystal nucleating agent, and one layer is the other. It is characterized in that the content of the plasticizer is higher than that of the above layer. Generally, a plasticizer is required according to the volume of the sheet that absorbs the impact in order to exert a relaxation action when an external impact is applied, but in a system in which the plasticizer is uniformly dispersed, a plasticizer according to the total volume The amount is required. As a result, the transparency and the rigidity decrease over the entire sheet. On the other hand, in the present invention in which a layer having a high plasticizer content (also referred to as a layer P) and a layer having a low content (also referred to as a layer Q) exist, the layer P having a high plasticizer content is responsible for external shock relaxation. If the same amount as the amount of plasticizer required in the uniform dispersion system is contained in the layer, the distribution ratio of the plasticizer is increased, and as a result, it is considered that the impact resistance is improved. In addition, the layer Q with a small amount of plasticizer can maintain the high transparency and rigidity originally possessed by the polylactic acid resin, thereby improving the transparency of the entire sheet and achieving both impact resistance and transparency. It is believed to be

  Here, in the layer Q containing a small amount of plasticizer, it is considered desirable to lower the degree of crystallinity from the viewpoint of improving the transparency. Therefore, conventionally, it has been considered desirable to reduce the amount of plasticizer and organic crystal nucleating agent in the layer Q as much as possible. In fact, in the example of Patent Document 1, high transparency is obtained in a mode in which the layer Q does not contain a plasticizer or an organic nucleating agent. However, when the present inventors examined the above-mentioned subject, it is surprising that the layer Q containing a small amount of plasticizer contains a specific amount of an organic crystal nucleating agent, whereby it is not only excellent in transparency but also more than the glass transition point. It has been found that it is possible to maintain the transparency during storage at the temperature of 1 and excellent in storage stability. The mechanism is not clear, but micro-crystallization of the layer Q in the range that does not deteriorate the transparency can prevent the migration and diffusion of the plasticizer from the layer P having a large plasticizer content to the layer Q. It is presumed that this is because the crystallization of the layer Q resulting from this can be suppressed. However, these guesses do not limit the present invention. In addition, the thing of the polylactic acid resin composition lamination sheet of this invention may only be described as the lamination sheet of this invention.

<Polylactic acid resin composition laminated sheet>
The polylactic acid resin composition laminate sheet of the present invention includes at least a layer P and a layer Q described later, and includes a plurality of layers of the polylactic acid resin composition. The layer P is disposed on the outermost layer of at least one of the front and back sides of the sheet, preferably on the outermost layers of the front and back sides, while the layer Q may be an inner layer, It is preferred that a layer Q be present between the layers P. For example, in the case of the three-layer structure, the layer Q is located at the center, and in the case of the five-layer structure, the layer Q can be disposed in any other than the outermost layer. The number of laminated layers is not particularly limited, but is preferably 3 or more and 8 or less, more preferably 3 or more and 5 or less from the viewpoint of impact resistance and formability, for example, layer P / layer Q / It is a lamination sheet laminated in order of layer P / layer Q / layer P and layer P / layer Q / layer P in order.

  In addition, the polylactic acid resin composition lamination sheet of the present invention may include layers other than the layer P and the layer Q. For example, the polylactic acid resin composition lamination sheet of the present invention is placed on itself The aspect containing various functional sheets, such as a sheet | seat which gives gas barrier property or heat sealability to the peeling sheet which can be peeled at the time, or the polylactic acid resin composition lamination sheet of this invention, is mentioned. Specifically, it is a sheet having a polyester resin composition such as PET, PBT or PTT, a polyolefin resin composition such as PE or PP, or a nylon resin composition. A well-known thing can be used for these functional sheets, and it can be made to laminate | stack on the appropriate position of the polylactic acid resin composition lamination sheet of this invention according to the function. For example, the release sheet can be attached to the outside of the polylactic acid resin composition laminate sheet of the present invention.

[Layer P]
The layer P in the present invention is a layer of a polylactic acid resin composition containing (P-A) polylactic acid resin, (P-B) plasticizer, and (P-C) organic crystal nucleating agent.

[(PA) polylactic acid resin]
As polylactic acid resin in the layer P, commercially available polylactic acid resin, for example, Nature Works, Inc .: Nature Works PLA / NW2003D, NW3001D, NW4032D, NW4060D, Toyota Motor Co., Ltd .: Ecoplastic U'z S-09 And S-12, S-17, etc., and polylactic acid resins synthesized from lactic acid and lactide. Among them, from the viewpoint of improving the impact resistance and the moldability of the polylactic acid resin composition of the layer P, a polylactic acid resin having an optical purity of preferably 90% or more, more preferably 95% or more is preferable. A company-made polylactic acid resin (such as NW4032D) can be used. The optical purity of poly (lactic acid) in the present invention is the content of D-form described in “Voltage standards for food containers and packaging made of polyolefins and other synthetic resins, etc. Third edition revised edition June 2004 Supplement Part 3 Sanitary test method P12-13” It can be determined according to the measurement method of quantity.

  Furthermore, in the present invention, a stereocomplex composed of two types of polylactic acid obtained using a lactic acid component containing, as a main component, different isomers as the polylactic acid resin from the viewpoint of strength and transparency of the polylactic acid resin composition. Polylactic acid resin may be used.

  In addition, the polylactic acid resin in the present invention may contain a biodegradable polyester resin other than the polylactic acid resin and a non-biodegradable resin such as polypropylene as a polymer alloy obtained by blending with the polylactic acid resin. In the present specification, “biodegradable” refers to the property of being able to be decomposed into low molecular weight compounds by microorganisms in nature, and more specifically, JIS K 6953 (ISO 14855) “controlled aerobic composting condition Means the biodegradability based on the “aerobic and ultimate biodegradation and decay test”.

  The content of the polylactic acid resin is preferably 80% by mass or more, more preferably 85% by mass or more, and preferably 98% by mass or less in the polylactic acid resin composition of the layer P from the viewpoint of impact resistance and transparency. 90 mass% or less is more preferable.

[(P-B) plasticizer]
The plasticizer used in the layer P is one or more selected from the group consisting of the following (i) and (ii) from the viewpoint of improving impact resistance and transparency and improving moldability. It is preferable to contain an ester compound.
(I) An ester compound having two or more ester groups in the molecule, wherein at least one of the alcohol components constituting the ester compound has an average of 0.5 to 3 alkylene oxides having 2 to 3 carbon atoms per hydroxyl group. And an ester compound which is an alcohol to which 8 moles are added, and (ii) a compound of the formula (I):
R ¹ O-CO-R ² -CO-[(OR ³ ) _m O-CO-R ² -CO-] _n OR ¹ (I)
(Wherein, R ¹ is an alkyl group having 1 to 4 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, R ³ is an alkylene group having 2 or 3 carbon atoms, and m is 1 to 6) And n represents a number of 1 to 12, provided that all R ^{2 s} may be the same or different and all R ^{3 s} may be the same or different)
A compound represented by

  As the ester compound (i), an ester having 2 or more, preferably 2 or more and 5 or less, more preferably 2 or more and 3 or less, in the molecule from the viewpoint of impact resistance, transparency and moldability. An ester compound having a group, wherein at least one of the alcohol components constituting the ester compound has an average of 0.5 mol or more and 8 mol or less, preferably 1 mol or more of alkylene oxide having 2 or 3 carbon atoms per hydroxyl group It is possible to use an ester compound which is an alcohol to which 6 mol or less, more preferably 1 to 3 mol is added. Among them, preferred is a polyhydric alcohol ester or polyhydric carboxylic acid ester having two or more, preferably two or more and five or less, more preferably two or more and three or less ester groups in the molecule, At least one of the alcohol components constituting the ester compound has an average of 0.5 to 8 moles, preferably 1 to 6 moles, and more preferably 1 mole of an alkylene oxide having 2 or 3 carbon atoms per hydroxyl group. It is possible to use an ester compound which is an alcohol added with 3 mol or less.

  Specifically, for example, plasticizers described in JP-A-2008-174718 and JP-A-2008-115372 can be mentioned. Among them, an ester of acetic acid and glycerin with an average of 3 to 6 moles of ethylene oxide adduct (addition of 1 to 2 moles of ethylene oxide per 1 hydroxyl group), an average addition mole number of acetic acid and ethylene oxide of 4 or more Ester with polyethylene glycol of 6 or less, ester with succinic acid and polyethylene glycol monomethyl ether having an average addition mole number of ethylene oxide of 2 or more and 6 or less (addition of 2 mol or more and 6 mol or less of ethylene oxide per hydroxyl group), adipine An ester of an acid and diethylene glycol monomethyl ether, and an ester of 1,3,6-hexanetricarboxylic acid and diethylene glycol monomethyl ether are preferably used.

  The ester compound of (ii) is preferable from the viewpoint of impact resistance, transparency, and bleed resistance.

R ¹ in the formula (I) represents an alkyl group having 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms, and is present in one molecule at two ends and at both ends of the molecule. R ¹ may be linear or branched as long as it has 1 or more and 4 or less carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group may be mentioned. Among them, the compatibility with polylactic acid resin is improved to bleed the plasticizer. A methyl group is preferable from the viewpoint of suppressing out, and the viewpoint of impact resistance and transparency.

R ² in the formula (I) represents an alkylene group having 2 to 4 carbon atoms, and a linear alkylene group is mentioned as a preferred example. Specific examples thereof include ethylene group, 1,3-propylene group and 1,4-butylene group, among which, from the viewpoint of improving the compatibility with the polylactic acid resin and suppressing the bleeding out of the plasticizer, and From the viewpoint of impact resistance and transparency, ethylene group and 1,3-propylene group are preferable, and ethylene group is more preferable. However, all R ^{2 s} may be the same or different.

R ³ in the formula (I) represents an alkylene group having 2 or 3 carbon atoms, and OR ³ represents an oxyalkylene group. Specifically, ethylene group, 1,2-propylene group, 1,3-propylene group may be mentioned. However, all R ^{3 s} may be the same or different.

  m represents the average number of repetition of the oxyalkylene group, and is a number of 1 or more and 6 or less. When m becomes large, the ether group value of the ester compound represented by the formula (I) tends to be increased, it tends to be oxidized, and the stability tends to be reduced. From the viewpoint of improving the compatibility with the polylactic acid resin, the number is preferably 1 or more, 4 or less, more preferably 1 or more and 3 or less, and still more preferably 1 or more and 2 or less.

  n shows an average degree of polymerization, and is a number of 1 or more and 12 or less. The number of 1 or more and 4 or less is preferable, and the number of 1 or more and 3 or less is more preferable, from the viewpoint of improving the compatibility with the polylactic acid resin and suppressing the bleed out of the plasticizer, and the impact resistance and transparency. A number of 1 or more and 2 or less is more preferable.

  Among such structures, from the viewpoint of transparency, at least one dibasic acid selected from succinic acid, glutaric acid, and adipic acid, and diethylene glycol, triethylene glycol, 1,2-propanediol, and 1,3- Oligoesters of at least one dihydric alcohol selected from propane diol [in the formula (I), n = 1 to 3] are preferred.

  The compound represented by the formula (I) may be a commercially available product or one synthesized according to a known production method, and may be produced, for example, according to the method disclosed in JP-A-2012-62467. be able to.

  In the present invention, plasticizers other than the above (i) and (ii) can be used as long as the effects of the present invention are not impaired. As other plasticizers, for example, polyester-based plasticizers, glycerin-based plasticizers, polyvalent carboxylic acid ester-based plasticizers, polyalkylene glycol-based plasticizers, and epoxy-based plasticizers other than the above (i) and (ii) An agent etc. can be used. The content of one or more ester compounds selected from the group consisting of (i) and (ii) in all plasticizers used in the present invention is 50% by mass from the viewpoint of impact resistance and transparency. The above is preferable, 70 mass% or more is more preferable, 90 mass% or more is further preferable, 95 mass% or more is still more preferable, 100 mass% is still more preferable. In the present specification, the content of one or more ester compounds selected from the group consisting of (i) and (ii) means the total content when a plurality of compounds are used. .

  From the viewpoint of impact resistance, the content of the plasticizer in the layer P is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, and 9 parts by mass or more with respect to 100 parts by mass of the polylactic acid resin of the layer P Is more preferable, 13 parts by mass or more is further preferable, 20 parts by mass or less is preferable, 18 parts by mass or less is more preferable, and 17 parts by mass or less is more preferable from the viewpoint of compatibility and formability.

  The content of the plasticizer in the polylactic acid resin composition of the layer P is preferably 4% by mass or more, more preferably 6% by mass or more, and still more preferably 8% by mass or more from the viewpoint of impact resistance. More preferably, it is 18% by mass or less, more preferably 15% by mass or less, and still more preferably 14% by mass or less from the viewpoint of transparency.

[(PC) organic crystal nucleating agent]
From the viewpoint of transparency, it is preferable to use at least one organic crystal nucleating agent selected from the group consisting of the following (a) to (d) as the organic crystal nucleating agent used in the layer P:
(A) a compound having an isoindolinone skeleton, a compound having a diketopyrrolopyrrole skeleton, a compound having a benzimidazolone skeleton, a compound having an indigo skeleton, a compound having a phthalocyanine skeleton, and a compound having a porphyrin skeleton At least one organic compound to be selected [referred to as an organic crystal nucleating agent (a)]
(B) at least one organic compound selected from the group consisting of carbohydrazides, uracils, and N-substituted ureas [referred to as an organic crystal nucleating agent (b)]
(C) at least one selected from the group consisting of metal salts of dialkyl aromatic sulfonates, metal salts of phosphoric acid esters, metal salts of phenylphosphonic acids, metal salts of rosin acids, aromatic carboxylic acid amides, and rosin acid amides Organic compounds [referred to as an organic crystal nucleating agent (c)]
(D) At least one organic compound selected from the group consisting of a compound having a hydroxyl group and an amide group in the molecule and a hydroxy fatty acid ester [referred to as an organic crystal nucleating agent (d)]

  Among these, from the viewpoint of improving transparency, the organic crystal nucleating agent (c) and the organic crystal nucleating agent (d) are preferable, and the organic crystal nucleating agent (d) is more preferable.

  The organic crystal nucleating agent (c) is preferably a metal salt of phenylphosphonic acid having a phenyl group which may have a substituent and a phosphonic group (-PO (OH) 2) from the above viewpoint, and phenylphosphonic acid Specific examples thereof include unsubstituted phenylphosphonic acid, methylphenylphosphonic acid, ethylphenylphosphonic acid, propylphenylphosphonic acid, butylphenylphosphonic acid, dimethoxycarbonylphenylphosphonic acid, diethoxycarbonylphenylphosphonic acid and the like. Unsubstituted phenylphosphonic acids are preferred.

  As the compound having a hydroxyl group and an amide group in the molecule of the organic crystal nucleating agent (d), an aliphatic amide having a hydroxyl group is preferable, and as a specific example, a hydroxy fatty acid monoamide such as 12-hydroxystearic acid monoethanolamide, methylene bis Examples thereof include hydroxy fatty acid bisamides such as 12-hydroxystearic acid amide, ethylene bis 12-hydroxystearic acid amide, and hexamethylene bis 12-hydroxystearic acid amide.

  The content of the organic crystal nucleating agent in the layer P is preferably 0.1 parts by mass or more from the viewpoint of improving the crystallinity of the layer P with respect to 100 parts by mass of the polylactic acid resin of the layer P. From the viewpoint of transparency, 1.0 parts by mass or less is preferable, 0.8 parts by mass or less is more preferable, 0.75 parts by mass or less is more preferable, and 0.5 parts by mass or less is further preferable preferable.

  The content of the organic crystal nucleating agent in the polylactic acid resin composition of the layer P is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of improving the degree of crystallization. .2 mass% or more is more preferable, and from the viewpoint of transparency, 1.0 mass% or less is preferable, 0.9 mass% or less is more preferable, and 0.5 mass% or less is still more preferable.

[(P-D) hydrolysis inhibitor]
From the viewpoint of improving impact resistance, the polylactic acid resin composition laminate sheet of the present invention can further use a hydrolysis inhibitor in addition to the above components.

  The hydrolysis inhibitor includes carbodiimide compounds such as polycarbodiimide compounds and monocarbodiimide compounds.

  As a monocarbodiimide compound, diphenyl carbodiimide, di-2, 6- dimethylphenyl carbodiimide, di 2, 6-diethyl phenyl carbodiimide, di 2, 6- diisopropyl phenyl carbodiimide, di 2, 6 di- tert- butyl Phenyl carbodiimide, di-o-tolyl carbodiimide, di-p-tolyl carbodiimide, di-2,4,6-trimethylphenyl carbodiimide, di-2,4,6-triisopropylphenyl carbodiimide, di-2,4,6- Aromatic monocarbodiimide compounds such as triisobutylphenylcarbodiimide; Alicyclic monocarbodiimide compounds such as di-cyclohexylcarbodiimide and di-cyclohexylmethanecarbodiimide; Di-isopropylcarbodiimide and di-octadecyl carbonate Aliphatic mono carbodiimide compounds such as Bojiimido like.

  Specifically, poly (4,4'-diphenylmethane carbodiimide), poly (p-phenylene carbodiimide), poly (m-phenylene carbodiimide), poly (diisopropyl phenyl carbodiimide), poly (triisopropyl phenyl carbodiimide) as the polycarbodiimide And aromatic polycarbodiimides; and alicyclic polycarbodiimides such as poly (dicyclohexylmethanecarbodiimide).

  The carbodiimide compounds may be used alone or in combination of two or more. Among these, from the viewpoint of impact resistance, di-2,6-diisopropylphenylcarbodiimide and poly (dicyclohexylmethanecarbodiimide) are preferable, and di-2,6-diisopropylphenylcarbodiimide is more preferable.

  The content of the hydrolysis inhibitor in the layer P is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the polylactic acid resin of the layer P from the viewpoint of improving the durability. It is more preferable, 0.3 parts by mass or more is further preferable, 3 parts by mass or less is preferable from the viewpoint of transparency improvement, 2 parts by mass or less is more preferable, and 1 part by mass or less is still more preferable.

  The polylactic acid resin composition in the layer P contains, as components other than the above, a lubricant, an inorganic crystal nucleating agent, a filler (inorganic filler, organic filler), a flame retardant, an antioxidant, an ultraviolet absorber, an antistatic An agent, an antifogging agent, a light stabilizer, a pigment, an antifungal agent, an antibacterial agent, a foaming agent, an impact modifier, etc. can be contained in the range which does not impair the effect of this invention. Similarly, it is possible to contain other polymer materials and other resin compositions as long as the effects of the present invention are not impaired. The amount of these used can be set appropriately according to known techniques.

  The polylactic acid resin composition in the layer P can be prepared without particular limitation as long as it contains the components (PA) to (PC), and for example, a polylactic acid resin, a plasticizer, and an organic Raw materials containing a crystal nucleating agent, and, if necessary, other additives including a hydrolysis inhibitor, may be used a known kneader such as a closed kneader, single-screw or twin-screw extruder, open-roll kneader, etc. It can be prepared by melt kneading. The raw materials can be subjected to melt-kneading after being uniformly mixed in advance using a Henschel mixer, a super mixer, or the like. In addition, in order to promote the plasticity of polylactic acid resin when preparing a polylactic acid resin composition, a supercritical gas may be present and melt mixed. After the melt-kneading, the melt-kneaded product may be dried according to a known method.

  The melt-kneading temperature is preferably 170 ° C. or more, preferably 220 ° C. or less, more preferably 200 ° C. or less, from the viewpoint of decomposition suppression and transparency. The melt-kneading time can not be determined generally depending on the melt-kneading temperature and the type of the kneader, but is preferably 15 seconds or more and 900 seconds or less.

  The polylactic acid resin composition in the layer P thus obtained can be layered (sheeted) in accordance with a known method. In the present invention, the layers P and Q may be separately sheeted and then laminated in a desired order, or the polylactic acid resin compositions of the layers P and Q may be laminated in a desired order You may sheet things at the same time. Details will be described later.

[Layer Q]
The layer Q in the present invention is a layer of a polylactic acid resin composition containing (Q-A) polylactic acid resin and (Q-C) organic crystal nucleating agent, and the content of the organic crystal nucleating agent is as follows: It is characterized in that it is a content.

[(Q-A) polylactic acid resin]
As the polylactic acid resin in the layer Q, the same one as the polylactic acid resin in the layer P can be used. Specifically, those exemplified in the section of the polylactic acid resin in the layer P. Among them, from the viewpoint of improving the transparency of the polylactic acid resin composition of layer Q, the optical purity is preferably 50% or more, more preferably 70% or more, still more preferably 80% or more, preferably 99% or less These polylactic acid resins are preferable, and for example, polylactic acid resins manufactured by Nature Works (NW2003D, 4032D, 4060D, etc.) can be used.

  In the polylactic acid resin composition of the layer Q, the content of the polylactic acid resin is preferably 95% by mass or more, and more preferably 99% by mass or more, from the viewpoint of rigidity and transparency.

[(Q-B) plasticizer]
The layer Q may further contain a plasticizer. The plasticizer in the layer Q may be the same as the plasticizer in the layer P, and specifically, those exemplified in the section of the plasticizer in the layer P can be mentioned.

  From the viewpoint of transparency, the content of the plasticizer in the layer Q is preferably 6 parts by mass or less, more preferably 5 parts by mass or less, and 4 parts by mass or less with respect to 100 parts by mass of the polylactic acid resin of the layer Q More preferably, 3 parts by mass or less is more preferable, and 2 parts by mass or less is still more preferable. The lower limit is not particularly set, but may be 0 parts by mass or more.

  Further, the content of the plasticizer in the polylactic acid resin composition of the layer Q is 0% by mass to 6% by mass, but from the viewpoint of transparency, 5.4% by mass or less is preferable, and 5% by mass or less Is more preferable, 4% by mass or less is more preferable, and 3% by mass or less is still more preferable. In the present specification, the content of the plasticizer of 0 parts by mass or 0% by mass is an embodiment in which the polylactic acid resin composition in the layer Q does not contain the plasticizer, and in the present invention, the layer A plasticizer may or may not be added to Q. Further, in the present invention, the plasticizer component may migrate from the layer P and be recognized in the layer Q, and the content in the above range is obtained, and the plasticizer content in the layer P is increased. It shall be included in the present invention.

  In the present invention, when a plasticizer is further contained in the layer Q, the plasticizer in the layer P and the plasticizer in the layer Q are characterized in that the content of the plasticizer in the layer P is high. . Based on the content of the polylactic acid resin in the layer Q as a content relative to 100 parts by mass of the polylactic acid resin in the layer Q, the content of the plasticizer in the layer P is the content of the plasticizer in the layer Q Preferably, the amount is preferably 1 part by mass or more, more preferably 2 parts by mass or more. Also, the upper limit is not particularly set.

  Moreover, as total content of the plasticizer used for the lamination sheet of this invention, 2 mass parts or more are preferable, and 3 mass parts or more are preferable, when the total content of the polylactic acid resin in a lamination sheet is 100 mass parts. More preferably, 4.5 parts by mass or more is further preferable, 6 parts by mass or more is further preferable, 16 parts by mass or less is preferable, 12 parts by mass or less is more preferable, and 10 parts by mass or less is still more preferable. In the present invention, sufficient impact resistance can be obtained even if the amount of plasticizer used as a whole is within the above range.

[(Q-C) organic crystal nucleating agent]
As the organic crystal nucleating agent used in layer Q, the same organic crystal nucleating agent as in layer P can be used, and specifically, those exemplified in the section of organic crystal nucleating agent in layer P can be mentioned. However, from the viewpoint of storage stability, the above-mentioned organic crystal nucleating agent (d) and the like are preferable.

  The content of the organic crystal nucleating agent in the layer Q is preferably 0.32 parts by mass or more, more preferably 0.35 parts by mass or more, from the viewpoint of storage stability with respect to 100 parts by mass of the polylactic acid resin of the layer Q Preferably, 0.40 parts by mass or more is more preferable, and from the viewpoint of transparency, 1.00 parts by mass or less is preferable, 0.90 parts by mass or less is more preferable, and 0.80 parts by mass or less is still more preferable.

  The content of the organic crystal nucleating agent in the polylactic acid resin composition of the layer Q is more than 0.3% by mass and 1% by mass or less, but from the viewpoint of storage stability, 0.32% by mass or more Is preferable, 0.35% by mass or more is more preferable, 0.40% by mass or more is further preferable, and from the viewpoint of transparency, 1.00% by mass or less is preferable, 0.90% by mass or less is more preferable, and 0. 80 mass% or less is still more preferable. In the present invention, the organic crystal nucleating agent component may be transferred from the layer P and recognized in the layer Q, and the content within the above range is included in the present invention.

  From the viewpoint of storage stability, the crystallinity of the layer Q is preferably 5% or more, more preferably 7% or more, and still more preferably 10% or more.

  The polylactic acid resin composition in the layer Q contains, as components other than the above, a hydrolysis inhibitor, a lubricant, an inorganic crystal nucleating agent, a filler (inorganic filler, organic filler), a flame retardant, an antioxidant, and ultraviolet light. An absorbent, an antistatic agent, an antifogging agent, a light stabilizer, a pigment, an antifungal agent, an antibacterial agent, a foaming agent, an impact modifier, etc. can be contained in the range which does not impair the effect of the present invention. Similarly, it is possible to contain other polymer materials and other resin compositions as long as the effects of the present invention are not impaired. The amount of these used can be set appropriately according to known techniques.

  The polylactic acid resin composition in the layer Q is not particularly limited as long as it contains the components (Q-A) and (Q-C), and further contains the component (Q-B) as necessary. It can be prepared in the same manner as the polylactic acid resin composition in the layer P. Specifically, the section of the preparation method of the polylactic acid resin composition in the layer P can be referred to.

  The polylactic acid resin composition in the layer Q thus obtained can be layered (sheeted) according to a known method. A known method can be selected as a method of laminating the layer P and the layer Q. Hereinafter, a method of simultaneously sheeting the polylactic acid resin compositions of the layer P and the layer Q in a desired order will be described.

  Specifically, for example, the laminated sheet is prepared by subjecting each polylactic acid resin composition of layer P and layer Q to melt coextrusion molding using a T-die such as feed block method or multi manifold method, for example. be able to. Here, the crystallinity of the sheet may be adjusted by bringing the obtained laminated sheet into contact with a cooling roll and then a heating roll, and then cutting may be performed. Moreover, you may uniaxially or biaxially stretch the obtained lamination sheet as needed. In addition, when filling into an extruder, after filling and melt-kneading the raw material which comprises each polylactic acid resin composition, you may extrusion-mold.

  The temperature of the extruder may be the same or different depending on the components of the polylactic acid resin composition of layer P and layer Q. Specifically, from the viewpoint of improving transparency, it is preferably 170 ° C. or more, more preferably 175 ° C. or more, still more preferably 180 ° C. or more, preferably 240 ° C. or less, more preferably 220 ° C. or less, still more preferably It can set suitably within the temperature range of 210 ° C or less. In the present invention, the temperature of the extruder means the cylinder temperature of the twin-screw kneading section of the extruder. The residence time in the extruder depends on the thickness and width of the sheet and the winding speed, and can not be generally specified. However, from the viewpoint of avoiding deterioration due to heat, about 30 seconds to several minutes is preferable.

  The temperature of the cooling roll is preferably less than 40 ° C., more preferably 30 ° C. or less, from the viewpoint of improving the transparency and improving the releasability from the cooling roll.

  The time of contact with the cooling roll is not necessarily specified because it varies depending on the setting temperature of the cooling roll, the number of cooling rolls, the extrusion speed, and the sheet winding speed, but, for example, transparency improvement and peelability improvement from the cooling roll From the point of view, it is preferably 1 second or more, more preferably 3 seconds or more, still more preferably 5 seconds or more, preferably 60 seconds or less, more preferably 50 seconds or less, still more preferably 40 seconds or less.

  The surface temperature of the heating roll is preferably 65 ° C. or more, more preferably 70 ° C. or more, still more preferably 75 ° C. or more, and preferably 100 ° C. or less, from the viewpoint of improving the transparency and the crystallinity. Moreover, 5 seconds or more are preferable, 10 seconds or more are more preferable, and, as for the sum total of the time which contacts the heating roll, 15 seconds or more are still more preferable. In addition, the surface temperature of a cooling roll and a heating roll means the temperature which measured the roll surface, and can be measured using a contact-type thermometer.

  Thus, the polylactic acid resin composition laminate sheet of the present invention is obtained. The thickness of the obtained laminated sheet is preferably 10 μm or more, more preferably 100 μm or more, preferably 1000 μm or less, more preferably 700 μm or less.

  In addition, each layer in the laminated sheet includes, for example, a plurality of layers P, and the thickness of the thickest one layer is preferably 5% or more, more preferably from the viewpoint of impact resistance with respect to the thickness of the entire laminated sheet. It is 7% or more, more preferably 11% or more, further preferably 15% or more, and from the viewpoint of transparency, preferably 40% or less, more preferably 35% or less, still more preferably 28% or less, further preferably 25 It is preferable that it is% or less.

  The ratio of the total thickness of layer P to the thickness of layer Q (layer P / layer Q) is preferably 80/20 to 10/90, more preferably 55/45 to 30/70.

  When a plurality of layers P is included, and the thickness of the thickest one layer is 5% or more and 28% or less with respect to the thickness of the entire laminated sheet, the content of the plasticizer in the layer P is an impact resistance point of view 6% by mass or more is preferable, 8% by mass or more is more preferable, 10% by mass or more is more preferable, and from the viewpoint of transparency, 15% by mass or less is preferable, and 14% by mass or less is more preferable.

  The haze value of the polylactic acid resin composition laminate sheet of the present invention is preferably 10% or less, more preferably 8% or less, and still more preferably 6% or less. In this specification, the haze value makes a sample of 5 cm x 5 cm x 0.3 mm from the sheet | seat after shaping | molding, The integrating sphere type | system | group light transmittance measurement apparatus of JIS-K7105 specification (HM-150 Murakami Color Research Laboratory) Measure using

  The polylactic acid resin composition laminate sheet of the present invention is excellent in transparency and excellent in storage stability, so it can be used as a packaging material for various applications such as daily necessities, cosmetics, home appliances, blister packs, trays, It can be suitably used as a material for food containers such as lids for lunch boxes and industrial trays used for transportation and protection of industrial parts.

  The present invention also provides a method for producing the polylactic acid resin composition laminate sheet of the present invention.

  The production method may be any method including a step of melt co-extrusion molding of the polylactic acid resin composition in the layer P and the polylactic acid resin composition in the layer Q. For example, the following method is suitably used.

Specifically, the manufacturing method which has following process (1)-(3) is mentioned.
Process (1): The polylactic acid resin which comprises layer P by melt-kneading the raw material containing (P-A) polylactic resin, (P-B) plasticizer, and (PC) organic crystal nucleating agent Step (2) of Preparing a Composition: Polylactic Acid Resin Composition Comprising Layer Q by Melt-kneading a Raw Material Containing (Q-A) Polylactic Acid Resin, and (Q-C) Organic Crystal Nucleating Agent A step of preparing the organic crystalline nucleating agent in the layer in an amount of more than 0.3% by mass and not more than 1.0% by mass,
Here, in the case where the layer Q further contains a (Q-B) plasticizer, the content of the (P-B) plasticizer in the layer P is the same as that of the (Q-B) plasticizer in the layer Q. Process step (3) having a content greater than the content: layer P is a sheet of the polylactic acid resin composition of layer P obtained in step (1) and the polylactic acid resin composition of layer Q obtained in step (2) Melt coextrusion to be the outermost layer of at least one of the front and back sides of

  Step (1) contains (P-A) polylactic acid resin, (P-B) plasticizer, and (P-C) organic crystal nucleating agent, and optionally (P-D) a hydrolysis inhibitor Raw materials containing other additives are preferably 170 ° C. or higher, preferably 220 ° C. or lower, using a known kneader such as a closed kneader, single-screw or twin-screw extruder, open-roll type kneader, etc. The polylactic acid resin composition in the layer P is prepared by melt-kneading at a temperature of preferably 200 ° C. or less. The raw materials and the conditions of the melt-kneading conform to the section of the polylactic acid resin composition lamination sheet of the present invention.

  In step (2), the raw material containing (Q-A) polylactic acid resin and (Q-C) organic crystal nucleating agent is added to the closed kneader, single-screw or twin-screw extruder, open roll kneader, etc. The polylactic acid resin composition in the layer Q is prepared by melt kneading at a temperature of preferably 170 ° C. or more, preferably 220 ° C. or less, more preferably 200 ° C. or less, using a known kneader. The raw materials and the conditions of the melt-kneading conform to the section of the polylactic acid resin composition lamination sheet of the present invention.

  In step (3), the polylactic acid resin composition obtained in step (1) and step (2) is melt coextruded. Melt co-extrusion molding can be performed using a known melt co-extrusion molding machine, and the conditions are appropriately set such that it becomes the outermost layer of at least one of the surface side and the back side of the sheet from which layer P is obtained. can do. For example, in the case of using a melt co-extrusion sheet forming machine (300 mm T-die manufactured by Giken Co., Ltd.) equipped with a cooling roll and a heating roll, it is possible to obtain a laminated sheet in which the crystallinity is adjusted. The conditions of the extruder and the conditions in the case of contacting with the subsequent cooling roll and heating roll conform to the section of the polylactic acid resin composition lamination sheet of the present invention.

The sheet after melt co-extrusion molding may be formed by cutting the end, and the cut end is mixed with the raw material of the polylactic acid resin composition constituting the layer P and / or the layer Q after melting. It can be used as a polylactic acid resin composition of each layer. Above all, it is preferable to use it by mixing with the raw material of the polylactic acid resin composition that constitutes the layer Q, and as another embodiment of the method for producing the polylactic acid resin composition laminated sheet of the present invention, And the like.
Step (4): A step of collecting and using a part of the melt co-extrusion molded product obtained in step (3) and mixing it with the raw material of the polylactic acid resin composition in step (2)

  The cutting of the end in step (4) can be performed according to known techniques. As a ratio which cut | judges an edge part, from a viewpoint of productivity, 50 mass% or less of a polylactic acid resin composition lamination sheet is preferable, 40 mass% or less is more preferable, and 30 mass% or less is still more preferable.

  Hereinafter, the present invention will be specifically described by way of examples. Note that this example is merely an example of the present invention and does not mean any limitation. Parts in the examples are parts by weight unless otherwise stated. In addition, "atmospheric pressure" shows 101.3 kPa and "normal temperature" shows 25 degreeC.

Production Example 1 of Plasticizer ((MeEO ₃ ) ₂ SA, diester compound of succinic acid and triethylene glycol monomethyl ether)
In a 3 L flask equipped with a stirrer, a thermometer, and a dehydration tube, 500 g of succinic anhydride, 2463 g of triethylene glycol monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd., reagent), paratoluenesulfonic acid monohydroxide (manufactured by Wako Pure Chemical Industries, Ltd. Reagents: 9.5 g was charged, and while reacting with nitrogen (500 mL / min) in a space, reaction was performed at 110 ° C. for 15 hours under reduced pressure (4 to 10.7 kPa). The acid value of the reaction solution was 1.6 mg KOH / g. After adding 27 g of adsorbent Kyoward 500SH (made by Kyowa Chemical Industry Co., Ltd.) to the reaction liquid and stirring at 80 ° C. and 2.7 kPa for 45 minutes and filtering, triethylene at a liquid temperature of 115 to 200 ° C. and pressure 0.03 kPa After distilling off glycol monomethyl ether and cooling to 80 ° C., the residue was filtered under reduced pressure to obtain a diester of succinic acid and triethylene glycol monomethyl ether [(MeEO ₃ ) ₂ SA] as a filtrate. The obtained diester had a weight average molecular weight of 410, a viscosity (23 ° C.) of 27 mPa · s, an acid value of 0.2 mg KOH / g, a saponification value of 274 mg KOH / g, a hydroxyl value of 1 mg KOH / g or less, and a hue APHA200. In addition, this plasticizer is an ester compound with the alcohol which 3 mol of ethylene oxide was added per hydroxyl group.

Production Example 2 of a plasticizer ((MeEO ₄ ) ₂ SA, a diester compound of succinic acid and tetraethylene glycol monomethyl ether)
In a 3 L flask equipped with a stirrer, thermometer, and dehydration tube, 500 g of succinic anhydride, 3124 g of tetraethylene glycol monomethyl ether, and 9.5 g of paratoluenesulfonic acid monohydroxide are charged, and nitrogen (500 mL / min) The reaction was carried out at 130 ° C. for 20 hours under reduced pressure (4 to 10.7 kPa) while blowing. The acid value of the reaction solution was 1.6 mg KOH / g. Add 27g of Adsorbent Kyoward 500SH to the reaction solution, stir for 45 minutes at 80 ° C and 2.7 kPa, filter, and distill off tetraethylene glycol monomethyl ether at a solution temperature of 150 to 250 ° C and a pressure of 0.003 kPa. After cooling to 80 ° C., the residue was filtered under reduced pressure to obtain, as a filtrate, the diester of succinic acid and tetraethylene glycol monomethyl ether [(MeEO ₄ ) ₂ SA]. The obtained diester had a weight average molecular weight of 499, a viscosity (23 ° C.) of 35 mPa · s, an acid value of 0.2 mg KOH / g, a saponification value of 225 mg KOH / g, a hydroxyl value of 1 mg KOH / g or less, and a hue APHA 230. In addition, this plasticizer is an ester compound with the alcohol which 4 mol of ethylene oxide was added per hydroxyl group.

Preparation Example 3 of a plasticizer ((MeEO ₆ ) ₂ SA, a diester compound of succinic acid and hexaethylene glycol monomethyl ether)
In a 3 L flask equipped with a stirrer, thermometer, and dewatering tube, 500 g of succinic anhydride, 4235 g of hexaethylene glycol monomethyl ether, and 9.5 g of paratoluenesulfonic acid monohydroxide are charged, and nitrogen (500 mL / min) The reaction was carried out at 150 ° C. for 40 hours under reduced pressure (4 to 10.7 kPa) while blowing. The acid value of the reaction solution was 1.6 mg KOH / g. Add 27g of Adsorbent Kyoward 500SH to the reaction solution and stir for 45 minutes at 80 ° C and 2.7kPa and filter, then distill off hexaethylene glycol monomethyl ether at a liquid temperature of 200 to 280 ° C and a pressure of 0.003kPa After cooling to 80 ° C., the residue was filtered under reduced pressure to obtain a diester of succinic acid and hexaethylene glycol monomethyl ether [(MeEO ₆ ) ₂ SA] as a filtrate. The obtained diester had a weight average molecular weight of 674, a viscosity (23 ° C.) of 42 mPa · s, an acid value of 0.2 mg KOH / g, a saponification value of 166 mg KOH / g, a hydroxyl value of 1 mg KOH / g or less, and a hue APHA 280. In addition, this plasticizer is an ester compound with the alcohol which added 6 mol of ethylene oxide per hydroxyl group.

Preparation Example 4 of plasticizer (MeSA-1,3PD, oligoester compound of dimethyl succinate and 1,3-propanediol)
86.8 g (1.14 mol) of 1,3-propanediol and 2.2 g of a 28 wt% sodium methoxide-containing methanol solution as a catalyst in a four-piece flask (with stirrer, thermometer, dropping funnel, distillation tube, and nitrogen blowing tube) (Sodium methoxide 0.011 mol) was added, and methanol was distilled off while stirring at 120 ° C. for 0.5 hours under normal pressure. Thereafter, 500 g (3.42 mol) of dimethyl succinate (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped over 2 hours, and methanol generated by the reaction was distilled off at 120 ° C. under normal pressure. Next, it is cooled to 75 ° C., and the pressure is gradually reduced from normal pressure to 6.7 kPa over 2 hours to distill off methanol, and then returned to normal pressure, and further, 28 wt% sodium methoxide-containing methanol as a catalyst A solution of 2.0 g (0.010 mol of sodium methoxide) was added, and the pressure was gradually reduced from atmospheric pressure to 2.9 kPa over 3 hours at 100 ° C. to distil out methanol. Then, after cooling to 80 ° C., 6 g of Kyoward 600S (manufactured by Kyowa Chemical Industry Co., Ltd.) was added and stirred at a pressure of 4.0 kPa and 80 ° C. for 1 hour, and then vacuum filtration was performed. The filtrate was heated at 114 ° C. to 194 ° C. at a pressure of 4.5 kPa for 1 hour to distill off residual dimethyl succinate, thereby obtaining [MeSA-1,3 PD] as a yellow liquid at room temperature. The amount of catalyst used was 0.61 mole per 100 moles of dicarboxylic acid ester. In addition, this plasticizer is an ester compound represented by Formula (I) (R1 is a methyl group, R2 is an ethylene group, R3 is a propylene group, m is 1, and n is 1.5).

Examples 1 to 7 and Comparative Examples 1 to 2
Preparation of Polylactic Acid Resin Composition As a polylactic acid resin composition, a composition raw material shown in Table 1 was obtained by using a twin-screw extruder (HK manufactured by Perker, HK25D, cylinder diameter 25.2 mm, rotation speed 100 rpm, discharge amount 8 kg / h) It melt-kneaded at 180-190 degreeC of melt-kneading temperature using this, strand cut was performed, and the pellet of the polylactic acid resin composition was obtained. The obtained pellet was dried at 110 ° C. under reduced pressure for 2 hours to make the water content 500 ppm or less.

Preparation of laminated sheet by coextrusion Multi-manifold type T-die extruder (300 mm T, manufactured by Plastic Engineering Research Institute, Inc.) Using a die, coextrusion sheet molding having a width of 250 mm was performed under the conditions of Table 2 to obtain a polylactic acid resin composition laminated sheet with a sheet thickness of 300 μm.

In addition, the raw material in Table 1 is as follows.
<Polylactic acid resin>
4032D: Ingeo (registered trademark) Biopolymer 4032D (poly-L-lactic acid, optical purity 98.5%, melting point 166 ° C., weight average molecular weight 180000) manufactured by NatureWorks LLC
<Plasticizer>
DAIFATTY-101: Mixed diester of adipic acid and diethylene glycol monomethyl ether / benzyl alcohol = 1/1, Daihachi Chemical Industry Co., Ltd.
(MeEO ₃ ) ₂ SA: diester compound produced in Production Example 1 of the plasticizer
(MeEO ₄ ) ₂ SA: diester compound produced in Production Example 2 of the plasticizer
(MeEO ₆ ) ₂ SA: diester compound MeSA-1, 3PD produced in Production Example 3 of the plasticizer: oligoester compound produced in Production Example 4 of the plasticizer <organic crystal nucleating agent>
SLIPAKX H: Ethylene bis 12-hydroxystearic acid amide, manufactured by Nippon Kasei Co., Ltd. <hydrolysis inhibitor>
BioAdmide 100: Diisopropylphenylcarbodiimide, manufactured by Rein Chemie

The characteristics of the obtained laminated sheet were evaluated according to the methods of Test Examples 1 to 3 below. The layer ratio was measured as follows. The results are shown in Table 1.
<Layer ratio>
The resin used for the inner layer is colored with a black pigment (carbon black), and the fractured surface of the obtained laminated sheet is prepared using a microtome, and is 200 times using an optical microscope (VHX-1000 manufactured by KEYENCE CORPORATION) It observed and measured sheet | seat thickness and the thickness of the colored layer of inner layer, and calculated | required the layer ratio.

Test Example 1
Transparency
A sample of 5 cm × 5 cm × 0.3 mm was prepared from the sheet after molding, and the haze value was measured using an integrating sphere type light transmittance measurement device (HM-150 Murakami Color Research Laboratory) defined in JIS-K7105. The smaller the value, the better the transparency. The results are shown in Table 1.

Test example 2
<Storage examination>
A sample of 5 cm × 5 cm × 0.3 mm is prepared from the sheet after molding, and stored for 7 days at a temperature of 60 ° C. and a humidity of 30% using a constant temperature and humidity chamber (PL-3J manufactured by ESPEC Co., Ltd.). The haze value was measured in the same manner as in. The results are shown in Table 1.

Storage stability
The difference in haze value before and after storage was calculated. If this difference is 1.5% or less, it means that storage stability is good. The results are shown in Table 1.

<Impact resistance>
A sample of 5 cm x 5 cm x 0.3 mm is prepared from the sheet after molding, and a Dupont type drop impact tester (No. 517-L manufactured by Yasuda Seiki Seisakusho, maximum drop height 1000 mm, interval 50 mm, diameter 19.05 mm) 50% impact fracture energy measured in an atmosphere with a temperature of 23.degree. C. according to JIS-K 7211-1 (2006), using a shooting type, a pedestal with a diameter of 19.05 mm, and a dropping weight of 100 to 1000 g as the impact strength . The larger the impact strength value, the better the impact resistance. The results are shown in Table 1.

  From Table 1, it can be seen that the polylactic acid resin composition laminate sheet of each example in which the layer Q contains an organic crystal nucleating agent is excellent in transparency, storage stability, and impact resistance. On the other hand, in Comparative Example 1 which does not contain the organic crystal nucleating agent and Comparative Example 2 in a small amount, although excellent in transparency immediately after preparation, storage stability is inferior to the polylactic acid resin composition laminated sheet of the present invention. Met.

  Since the polylactic acid resin composition laminate sheet of the present invention is excellent in transparency and storage stability, it is suitably used for various applications such as food containers, packaging materials for daily necessities and home appliances, trays for industrial parts, etc. Can.

Claims (7)

It is a polylactic acid resin composition lamination sheet including a plurality of layers of a polylactic acid resin composition, and is a polylactic acid resin composition lamination sheet including at least a next layer P and a layer Q,
The layer P is a layer of a polylactic acid resin composition containing (P-A) polylactic acid resin, (P-B) plasticizer, and (P-C) organic crystal nucleating agent,
Layer Q is a layer of a polylactic acid resin composition containing (Q-A) polylactic acid resin and (Q-C) organic crystal nucleating agent, and containing (Q-C) organic crystal nucleating agent in the layer The amount is more than 0.3% by mass and not more than 1.0% by mass,
Here, in the case where the layer Q further contains a (Q-B) plasticizer, the content of the (P-B) plasticizer in the layer P is the same as that of the (Q-B) plasticizer in the layer Q. Polylactic acid resin composition lamination sheet whose content is more than content and at least one outermost layer of the surface side and back side of a sheet is layer P.   The polylactic acid resin composition lamination sheet according to claim 1, wherein the content of the (P-B) plasticizer in the layer P is 4% by mass to 18% by mass.   The polylactic acid resin composition lamination sheet according to claim 1 or 2, wherein the content of the (PC) organic crystal nucleating agent in the layer P is 0.05% by mass or more and 1.0% by mass or less.   The polylactic acid according to any one of claims 1 to 3, comprising a plurality of layers P, wherein the thickness of the thickest one of the layers P is 5% or more and 40% or less with respect to the thickness of the polylactic acid resin composition laminated sheet. Resin composition lamination sheet.   The polylactic acid resin composition lamination sheet according to any one of claims 1 to 4, wherein a plurality of layers P are included, and the layer Q is laminated between at least two layers P. (P-B) plasticizer and / or (Q-B) plasticizer are
(I) An ester compound having two or more ester groups in the molecule, wherein at least one of the alcohol components constituting the ester compound has an average of 0.5 to 3 alkylene oxides having 2 to 3 carbon atoms per hydroxyl group. And an ester compound which is an alcohol to which 8 moles are added, and (ii) a compound of the formula (I):
R ¹ O-CO-R ² -CO-[(OR ³ ) _m O-CO-R ² -CO-] _n OR ¹ (I)
(Wherein, R ¹ is an alkyl group having 1 to 4 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, R ³ is an alkylene group having 2 or 3 carbon atoms, and m is 1 to 6) And n represents a number of 1 to 12, provided that all R ^{2 s} may be the same or different and all R ^{3 s} may be the same or different)
The polylactic acid resin composition laminate sheet according to any one of claims 1 to 5, comprising one or more selected from the group consisting of compounds represented by It is a manufacturing method of the polylactic acid resin composition lamination sheet containing the layer of a plurality of polylactic acid resin compositions, and manufacture of the polylactic acid resin composition lamination sheet containing following process (1), (2), and (3) Method.
Process (1): The polylactic acid resin which comprises layer P by melt-kneading the raw material containing (P-A) polylactic resin, (P-B) plasticizer, and (PC) organic crystal nucleating agent Step (2) of Preparing a Composition: Polylactic Acid Resin Composition Comprising Layer Q by Melt-kneading a Raw Material Containing (Q-A) Polylactic Acid Resin, and (Q-C) Organic Crystal Nucleating Agent A step of preparing the organic crystalline nucleating agent in the layer in an amount of more than 0.3% by mass and not more than 1.0% by mass,
Here, in the case where the layer Q further contains a (Q-B) plasticizer, the content of the (P-B) plasticizer in the layer P is the same as that of the (Q-B) plasticizer in the layer Q. Process step (3) having a content greater than the content: layer P is a sheet of the polylactic acid resin composition of layer P obtained in step (1) and the polylactic acid resin composition of layer Q obtained in step (2) Melt coextrusion to be the outermost layer of at least one of the front and back sides of