JP2009079124A - Biodegradable polyester resin composition and molded body formed of it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition having melt viscosity suitable for molding processing, heat resistance, and good appearance. <P>SOLUTION: The polyester resin composition comprises a biodegradable polyester resin A, an inorganic filler B, and an epoxy functional chain extender with weight-average epoxy functional group number 3 or more. A mass ratio A/B of the component A to the component B is 99.9/0.1-80/20. The content of the component C is 0.05-10 pts.mass to 100 pts.mass of the total of the components A and B. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biodegradable polyester resin composition, a production method thereof, and a molded body using the same.

  In recent years, biodegradable resins such as polylactic acid have attracted attention from the viewpoint of environmental conservation. Among the biodegradable resins, polylactic acid has good transparency and can be mass-produced from plant-derived raw materials such as corn and sweet potato, which can reduce costs and contribute to reducing the use of petroleum raw materials. Therefore, it is highly useful.

  However, a biodegradable resin containing polylactic acid has insufficient heat resistance, and a method of adding a layered silicate which is a plate-like inorganic filler has been proposed to improve this problem (Non-Patent Document). 1). However, when a layered silicate is added to a biodegradable resin, the dispersibility is not sufficient, and therefore aggregation easily occurs, which may cause a problem in the appearance of a molded product using the resin. For this reason, this method is unsuitable for resin compositions used for packaging materials and containers that often require a good appearance.

  As a method for reducing aggregates, a method of increasing dispersibility by kneading with polylactic acid at a melting point or lower using a layered silicate swollen in advance with water or an aqueous solvent is disclosed (Patent Document 1). However, this method requires a special kneading machine and is not economically preferable. Further, the molecular weight of the resin composition is lowered during kneading, which may cause thermal deterioration during molding. In addition, a method of improving dispersibility using a layered silicate in which a lactide or a low molecular weight polylactic acid having a number average molecular weight of 50000 or less is inserted between layers to increase the distance between layers is proposed (Patent Document 2). ). However, this method has room for further improvement with respect to the dispersibility of the layered silicate. Furthermore, a film in which a layered silicate is dispersed in polylactic acid using a compound having a number average molecular weight of 200 to 50,000 consisting of repeating alkylene oxide units has been proposed (Patent Document 3). However, since the alkylene oxide compound has high hydrophilicity and does not have high heat resistance, the amount that can be added is limited. Therefore, even with this method, there is room for further improvement with respect to the dispersibility of the layered silicate.

  On the other hand, polylactic acid in a molten state at the time of forming a film or sheet has a low melt viscosity and melt tension, so that it causes necking in the production process and is difficult to control the thickness and width. Inflation molding tends to cause problems such as the frost line becoming unstable, and blow molding in which the parison draws down, resulting in uneven thickness in the molded product. Therefore, as a means for improving melt viscosity and melt tension, a method of adding an acrylic resin modifier to an aliphatic polyester has been disclosed (Patent Document 4). Although this method improves the melt viscosity and melt tension, no method for improving the heat resistance of the aliphatic polyester has been proposed.

  In addition, a large amount of polymerization catalyst may be added to produce a polymer having a melt viscosity suitable for the molding process of bottles and films, but a heat history of the molding process is added to a polymer containing a large amount of catalyst residue. It is known that the polymer tends to deteriorate and a molecular weight decrease and yellowing associated therewith occur (Non-Patent Document 2). The yellowed plastic has a low commercial value. For this reason, this method is unsuitable for resin compositions used for packaging materials and containers that often require a good appearance. In addition, polymers with low melt viscosity have a good color tone due to a low heat history, but if the melt viscosity is low, the shear force during melt kneading is low, so the filler added to improve heat resistance is sufficiently dispersed. I couldn't let you.

  Therefore, the biodegradable polyester material has a melt viscosity suitable for molding processing, the obtained molded body has excellent heat resistance, and has an excellent appearance that can be used for packaging materials and containers. Was not yet offered.

“Polymer Papers”, 2002, Vol. 59, No. 12, p. 760-766 “Polymer life-extending technology”, CMC Corporation, January 2001, p. 35 JP 2004-027136 A JP 2004-323758 A JP 2003-261695 A JP 2006-265399 A

  The present invention solves the problems as described above, and has a polyester resin composition having a melt viscosity suitable for molding of bottles and films, heat resistance, and a good appearance. The issue is to provide.

As a result of intensive studies to solve the above problems, the present inventors can produce bottles and films with high productivity by adding a filler and a chain extender to a biodegradable polyester resin. It has been found that a polyester resin composition having a good melt viscosity, heat resistance and good appearance can be provided. Further, it has been found that the addition of a dispersant can increase the transparency with few aggregates. Furthermore, it discovered that the polyester resin composition excellent also in the color tone and heat stability can be provided by adding antioxidant and / or terminal blocker.
That is, the gist of the present invention is as follows.
(1) A polyester resin composition comprising a biodegradable polyester resin (A), an inorganic filler (B), and an epoxy functional chain extender (C) having a weight average number of epoxy functional groups of 3 or more. The mass ratio (A / B) of (A) and (B) is 99.9 / 0.1 to 80/20, and the content of (C) is the sum of (A) and (B). A polyester resin composition characterized by being 0.05 to 10 parts by mass with respect to 100 parts by mass.
(2) The polyester resin composition according to (1), wherein the biodegradable polyester resin (A) contains 50% by mass or more of polylactic acid.
(3) The polyester resin composition according to (1) or (2), wherein the inorganic filler (B) is a plate-like inorganic filler.
(4) The chain extender (C) has a weight average number of epoxy functional groups of 3 to 30, a glass transition temperature of 0 to 70 ° C., an epoxy equivalent of 180 to 2800 g / mol, and a weight average molecular weight of 2. The polyester resin composition according to any one of (1) to (3), wherein the polyester resin composition is from 4,000 to 40,000.
(5) The chain extender (C) is a copolymer formed from an epoxy-functional (meth) acrylic monomer and a non-functional (meth) acrylic monomer and / or a styrene monomer (1) to (4) The polyester resin composition in any one.
(6) It contains at least one dispersant (D) selected from polyether phosphate ester, fatty acid ester, polyhydric alcohol ester, polyvalent carboxylic acid ester, and polar wax, and the content is (A ) And (B) with respect to a total of 100 parts by mass, the polyester resin composition according to any one of (1) to (5), which is 0.1 to 15 parts by mass.
(7) The phosphite antioxidant (E) is contained, and the content thereof is 0.01 to 5 parts by mass with respect to 100 parts by mass in total of (A) and (B). The polyester resin composition according to any one of (1) to (6).
(8) The terminal blocker (F) is contained, and the content thereof is 0.1 to 5 parts by mass with respect to 100 parts by mass in total of (A) and (B) (1 The polyester resin composition according to any one of (7) to (7).
(9) The melt index (MI) measured at 190 ° C. and 2.16 kgf is 0.1 to 10.0 (g / 10 minutes), according to any one of (1) to (8) Polyester resin composition.
(10) The polyester resin composition according to any one of (1) to (9), wherein YI is 30 or less, and haze is 50% or less when a molded body having a thickness of 1 mm is formed.
(11) Any of (1) to (10), wherein an inorganic filler (B) and a chain extender (C) are added to the biodegradable polyester resin (A) at the time of melt kneading. The manufacturing method of the polyester resin composition of description.
(12) A molded article comprising the polyester resin composition according to any one of (1) to (10) above.

  According to the present invention, a biodegradable polyester resin composition having improved moldability and heat resistance is provided by adding an inorganic filler, a chain extender, and a dispersant to the biodegradable polyester resin. can do. In particular, inorganic fillers are effective in improving heat resistance, and chain extenders are effective in improving moldability. Moreover, since the resin composition of the present invention has biodegradability, it can be composted when discarded, and the amount of waste can be reduced and reused as a fertilizer. Further, when plant-derived polylactic acid is used as the biodegradable polyester resin, it contributes to prevention of depletion of petroleum resources and can be provided as an environmentally friendly material.

Hereinafter, the present invention will be described in detail.
<Biodegradable polyester resin (A)>
In the present invention, the biodegradable polyester resin (A) includes an aliphatic polyester mainly composed of either an α- and / or β-hydroxycarboxylic acid unit and an ω-hydroxyalkanoate unit, or an aliphatic group. Examples include polyesters composed of a dicarboxylic acid component and an aliphatic diol component.

Examples of α- and / or β-hydroxycarboxylic acid units include D-lactic acid, L-lactic acid, mixtures thereof, glycolic acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-hydroxycaproic acid, and the like, and These mixtures and copolymers may be mentioned. D-lactic acid and L-lactic acid are particularly preferred.
Examples of the ω-hydroxyalkanoate unit include ε-caprolactone and δ-valerolactone.
Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, or a lower alkyl ester compound as a derivative thereof, an acid anhydride, and the like. Of these, succinic acid, succinic anhydride, and adipic acid are preferable.
Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and the like. Particularly preferred is 1,4-butanediol.
As long as the biodegradability of the polyester resin is not impaired, an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid may be copolymerized. Such a copolyester is also referred to in the present invention. include.

Specific examples of the biodegradable polyester resin (A) in the present invention include poly (D-lactic acid) and poly (L-lactic acid), poly (ethylene succinate), poly (butylene succinate), and poly (butylene). Aliphatic polyesters composed of diols and dicarboxylic acids such as succinate-co-butylene adipate), polyglycolic acid, poly (3-hydroxybutyric acid), poly (3-hydroxyvaleric acid), poly (3-hydroxycapron) Acid) and the like, poly (ω-hydroxyalkanoate) represented by poly (ε-caprolactone) and poly (δ-valerolactone), poly (butylene succinate-co-butylene terephthalate), poly ( Polyethylene containing aromatic components such as butylene adipate-co-butylene terephthalate) Ether resins, polyester amides, polyester carbonates, polysaccharides starch and the like. These components may be used alone or in combination of two or more, may be mixed, or may be copolymerized.
These resins are produced by a known melt polymerization method. Poly (3-hydroxybutyric acid) and poly (3-hydroxyvaleric acid) can be produced by microorganisms.

  In the present invention, when the biodegradable polyester resin (A) containing 50% by mass or more of polylactic acid is used, the effect on the environment is high because the degree of plant origin is high, and transparency, heat resistance and It is further preferable to balance the above. The content ratio of L-lactic acid and D-lactic acid is not particularly limited as polylactic acid, but commercially available (L-lactic acid / D-lactic acid) or (D-lactic acid / L-lactic acid) is 80. Those in the range of / 20 to 99.95 / 0.05 (molar ratio) can be used without limitation. The content of polylactic acid is preferably 60% by mass or more, more preferably 80% by mass or more.

  When a resin composed of plant-derived raw materials is used as the resin composition of the present invention as a resin other than polylactic acid, the plant-derived resin content increases, and the effect of reducing the amount of petroleum resources used increases. Examples of the resin made of plant-derived materials include polylactic acid, nylon 11 and natural rubber.

  In the present invention, the molecular weight of the biodegradable polyester resin (A) is not particularly limited, but the melt index (MI) at 190 ° C. and 2.16 kgf (21.2 N) as an index is 0.1 to 50 (g / 10 minutes), the polyester resin can be preferably used. A more preferable range is 0.2 to 40 (g / 10 minutes).

  When polylactic acid is used as the biodegradable polyester resin (A) in the present invention, the weight average molecular weight (Mw) of the resin composition is not particularly limited, but considering the processability and the strength of the molded body, Mw is It is preferably 50,000 or more, more preferably in the range of 70,000 to 400,000, still more preferably in the range of 80,000 to 250,000, and most preferably 85,000 to 160,000. Range. The above Mw is converted to polystyrene when measured using a gel permeation chromatography apparatus (GPC) equipped with a differential refractive index detector and tetrahydrofuran (THF) as an eluent at a flow rate of 1.0 ml / min and 40 ° C. This is the value obtained in.

<Inorganic filler (B)>
In order to obtain a resin composition excellent in mechanical properties, moldability, heat resistance, and the like, it is necessary to add an inorganic filler (B) to the resin composition of the present invention.
As the filler, a fibrous, plate-like, granular, or powder-like material that is usually used as a thermoplastic resin filler can be used without limitation.
Specifically, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium-based whisker, silicon-based whisker, wollastonite, sepiolite, asbestos, slag fiber, zonolite, elastadite, Fibrous inorganic fillers such as gypsum fiber, silica fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber and boron fiber, glass flake, non-swellable mica, swellable mica such as synthetic fluorine mica, layered silicate , Graphite, metal foil, ceramic beads, talc, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, laponite, fine silicate, feldspar powder, potassium titanate, shirasu balloon, calcium carbonate, magnesium carbonate, sulfur Barium, calcium oxide, aluminum oxide, titanium oxide, aluminum silicate, silicon oxide, gypsum, novaculite, include plate-like or granular inorganic fillers such as dawsonite and white clay.
The filler may be coated or focused with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or with a coupling agent such as aminosilane or epoxysilane. It may be.
Among these fillers, plate-like inorganic fillers are preferred, layered silicates such as bentonite and swellable synthetic fluorine mica, talc and graphite are more preferred, and layered silicates are particularly preferred.

Specific examples of layered silicates that are one type of swellable layered clay mineral that can be used in the present invention include smectite, vermiculite, and swellable fluorinated mica. Examples of smectites include montmorillonite, beidellite, hectorite and saponite. Examples of vermiculite include Na-type vermiculite, Li-type vermiculite, and Mg-type vermiculite. Examples of the swellable fluorine mica include Na-type fluorine tetrasilicon mica, Na-type teniolite, Li-type teniolite, and the like.
In addition to the above, layered silicates that do not contain aluminum or magnesium, such as kanemite, macatite, magadiite, and kenyaite, can also be used.
Preferred layered silicates include montmorillonite and swellable fluorinated mica.
The layered silicate may be a synthetic product in addition to a natural product, and examples of the synthesis method include a melting method, an intercalation method, and a hydrothermal method, and any method may be used.
These layered silicates may be used alone, or may be used in combination of two or more kinds having different mineral types, origins, particle sizes and the like.

In order to improve the dispersibility of the layered silicate in the biodegradable polyester resin (A), primary to quaternary ammonium ions, pyridinium ions, imidazolium ions or phosphonium ions are ionized between the layered silicate layers. Bonding is preferred.
Primary to tertiary ammonium ions are protonated corresponding primary to tertiary amines, and examples of primary amines include octylamine, dodecylamine, octadecylamine and the like.
Examples of secondary amines include dioctylamine, methyloctadecylamine, and dioctadecylamine.
Examples of the tertiary amine include trioctylamine, dimethyldodecylamine, didodecylmonomethylamine and the like.
Quaternary ammonium ions include dihydroxyethyl methyl octadecyl ammonium, tetraethyl ammonium, octadecyl trimethyl ammonium, dimethyl dioctadecyl ammonium, hydroxyethyl dimethyl octadecyl ammonium, hydroxyethyl dimethyl dodecyl ammonium, benzyl dihydroxyethyl dodecyl ammonium, benzyl dihydroxyethyl octadecyl ammonium, dodecyl. (Dihydroxyethyl) methylammonium, octadecyl (dihydroxyethyl) methylammonium, N, N-bis (2-hydroxyethyl) -N- (3'-dodecyloxy-2'-hydroxypropyl) methylammonium, methyldodecylbis (polyethylene) Glycol) ammonium, methyldiethyl ( Such as polypropylene glycol) ammonium.
Examples of the pyridinium ion include 1-dodecylpyridinium.
Examples of the imidazolium ion include 1-ethylmethylimidazolium, 1-heptadecyl-2,2′-ethylhydroxyethylimidazolium, and the like.
Furthermore, examples of the phosphonium ion include tetraethylphosphonium, tetrabutylphosphonium, hexadecyltributylphosphonium, tetrakis (hydroxymethyl) phosphonium, 2-hydroxyethyltriphenylphosphonium, and the like.
Of these, dihydroxyethylmethyloctadecylammonium, hydroxyethyldimethyloctadecylammonium, hydroxyethyldimethyldodecylammonium, dodecyl (dihydroxyethyl) methylammonium, octadecyl (dihydroxyethyl) methylammonium, N, N-bis (2-hydroxyethyl)- N- (3'-dodecyloxy-2'-hydroxypropyl) methylammonium, methyldodecylbis (polyethylene glycol) ammonium, methyldiethyl (polypropylene glycol) ammonium, 2-hydroxyethyltriphenylphosphonium, etc. The layered silicate treated with ammonium ions or phosphonium ions having the above hydroxyl groups is a parent to the biodegradable polyester resin. Sex particularly high, in order to improve the dispersibility of the layered silicate, particularly preferred. These ionic compounds may be used alone or in combination of two or more.

  There is no particular limitation on the method of treating the layered silicate with the primary to quaternary ammonium ions, pyridinium ions, imidazolium ions, and phosphonium ions. For example, a layered silicate is first dispersed in water or alcohol, and then the above primary to tertiary amine and acid (such as hydrochloric acid), or a quaternary ammonium salt or phosphonium salt is added and mixed by stirring to form a layered layer. Examples include a method in which inorganic ions between silicate layers are ion-exchanged with the above ammonium ions and phosphonium ions, followed by filtration, washing, and drying.

  In the resin composition of the present invention, the mass ratio (A / B) of the biodegradable polyester resin (A) and the inorganic filler (B) needs to be 99.9 / 0.1 to 80/20. Yes, it is preferably 99.5 / 0.5 to 90/10, more preferably 99/1 to 95/5. When the blending amount of the inorganic filler (B) is less than 0.1% by mass, the heat resistance improvement effect intended by the present invention cannot be obtained. Moreover, when it exceeds 20 mass%, there exists a tendency for the shaping | molding workability by deterioration of an external appearance, a molecular weight fall, etc. to fall.

<Chain extender (C)>
The number of weight average epoxy functional groups (EFW) of the chain extender (C) used in the present invention is the number of weight average epoxy functional groups represented by (EFW) = (weight average molecular weight) / (epoxy equivalent). In the present invention, the EFW of the chain extender (C) needs to be 3 or more, preferably 3 to 30, more preferably 5 to 28, and more preferably 10 to 25. Most preferred. When the EFW of the chain extender (C) is less than 3, the thickening effect on the biodegradable polyester resin (A) is small, and the moldability cannot be sufficiently improved. On the other hand, when it exceeds 30, an excessive epoxy group causes excessive crosslinking reaction with the carboxyl group or hydroxyl group of the biodegradable polyester resin (A), or a hydrogen abstraction reaction, and the moldability deteriorates. There is a case.

The glass transition temperature of the chain extender (C) used in the present invention is preferably 0 to 70 ° C., the glass transition temperature is more preferably 30 ° C. or higher, and further preferably 50 ° C. or higher from the viewpoint of operation.
Further, the epoxy equivalent of the chain extender (C) is preferably 180 to 2800 g / mol, more preferably 200 to 1000 g / mol in order to adjust to an appropriate melt viscosity which is the object of the present invention. Preferably, it is 200-450 g / mol.
Furthermore, the weight average molecular weight of the chain extender (C) is preferably 2,000 to 40,000, and preferably 3,500 to 25,000 in order to mix well with the biodegradable polyester resin (A). Is more preferable, and it is more preferable that it is 4,000-15,000.

  In the present invention, the chain extender (C) has, for example, polyethylene, polypropylene, polystyrene, polybutene, polybutadiene, polybutadiene hydrogenated polymer, polyethylene butylene, polyisobutylene, cycloolefin, and other olefins, or vinyls, Those having a resin structure such as acrylic, ester or amide are preferred. These may be copolymerized, or an epoxy group may be directly added to the above resin structure, or a structure obtained by grafting a polymer having an epoxy group added to the above resin structure.

  Preferred embodiments of the chain extender (C) in the present invention are produced from at least one epoxy-functional (meth) acrylic monomer and at least one non-functional (meth) acrylic monomer and / or styrene monomer. Mention may be made of epoxy-functional (meth) acrylic copolymers. The term (meth) acrylic monomer used in this specification includes both acrylic monomer and methacrylic monomer.

  Examples of epoxy-functional (meth) acrylic monomers that make up the chain extender (C) include both acrylic esters and methacrylic esters. Specific examples of these monomers include glycidyl acrylate, methacrylic acid. Monomers containing 1,2-epoxy groups such as glycidyl are included but are not limited thereto. An epoxy functional monomer such as allyl glycidyl ether, glycidyl ethacrylate, or glycidyl itaconate may be used in combination.

Examples of the non-functional acrylic acid monomer constituting the chain extender (C) include acrylic acid esters, specifically, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, N-butyl acrylate, s-butyl acrylate, i-butyl acrylate, t-butyl acrylate, n-amyl acrylate, i-amyl acrylate, isobornyl acrylate, n-hexyl acrylate, 2-acrylate Examples include ethyl butyl, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, methyl cyclohexyl acrylate, cyclopentyl acrylate, and cyclohexyl acrylate.
Further, examples of the non-functional methacrylic acid monomer constituting the chain extender (C) include methacrylic acid esters. Specifically, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-methacrylic acid n- Butyl, i-propyl methacrylate, i-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, i-amyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-ethylbutyl methacrylate, Examples include, but are not limited to, methyl cyclohexyl methacrylate, cinnamyl methacrylate, crotyl methacrylate, cyclohexyl methacrylate, cyclopentyl methacrylate, 2-ethoxyethyl methacrylate, and isobornyl methacrylate.
Nonfunctional acrylic ester monomers and nonfunctional methacrylate monomers include butyl acrylate, butyl methacrylate, methyl methacrylate, iso-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, and methacrylic acid. Isobornyl acids are included, and combinations thereof are particularly suitable.
Furthermore, as the non-functional styrene monomer constituting the chain extender (C), styrene, alpha-methylstyrene, vinyltoluene, p-methylstyrene, t-butylstyrene, o-chlorostyrene, vinylpyridine, and these Examples include, but are not limited to, mixtures of chemical species. As the styrene monomer, styrene and alpha-methylstyrene are preferably used.

  As an example of the mass ratio (mass%) of each monomer (epoxy functional (meth) acrylic monomer / styrene monomer / nonfunctional (meth) acrylic acid ester monomer) constituting the chain extender (C), 50 to 80 / 20-50 / 0, 25-50 / 15-30 / 20-60, 50-80 / 15-45 / 0-5, 5-25 / 50-95 / 0-25, etc. are mentioned.

  Such chain extenders composed of an epoxy-functional (meth) acrylic monomer and a non-functional (meth) acrylic and / or styrene monomer are disclosed in, for example, JP-A-57-502171 and JP-A-59-6207. Can be produced by known methods described in JP-A-60-215007, JP 2005-517061, U.S. Patent Application No. 09/354350 and U.S. Patent Application No. 09/614402. Except as specified in the invention, it can be used without limitation.

  Particularly preferred as the chain extender (C) has a structure in which an epoxy group is added to the skeleton of polyethylene or polypropylene. As a commercially available epoxy group-containing additive having such a structure, Modiper A4200 ( (Nippon Yushi Co., Ltd.), Bond First 2C, Bond First E (all manufactured by Sumitomo Chemical Co., Ltd.), ARUFON UG4030 (manufactured by Toagosei Co., Ltd.), JONCRYL-ADR4300, JONCRYL-ADR4368 (all manufactured by BASF) it can.

  The content of the chain extender (C) needs to be 0.05 to 10 parts by mass with respect to 100 parts by mass in total of the biodegradable polyester resin (A) and the inorganic filler (B), It is preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass. When the content of the chain extender (C) is less than 0.05 parts by mass, the melt viscosity of the resin composition cannot be improved, and the moldability may not be improved. On the other hand, when the content exceeds 10 parts by mass, the resin composition may have a high viscosity and the moldability may be reduced.

<Dispersant (D)>
For the purpose of improving the dispersibility of the inorganic filler (B), the resin composition of the present invention is selected from polyether phosphate esters, fatty acid esters, polyhydric alcohol esters, polycarboxylic acid esters, and polar waxes. It is preferable to add at least one dispersant (D).

The polyether phosphate ester is preferably a compound represented by the following general formula (1) and / or general formula (2).
R—O (CH ₂ CH ₂ O) _n —PO (OH) ₂ (1)
_{(R-O (CH 2 CH} 2 O) n -) 2 -PO (OH) (2)
In the general formulas (1) and (2), R represents an alkyl group having 4 to 20 carbon atoms, an alkylaryl group having 6 to 20 carbon atoms, or an alkylphenoxy group having 6 to 20 carbon atoms. n represents an integer of 1 to 50. Commercially available products may be used, and as the compounds represented by the formulas (1) and (2), Disparon DA375 (manufactured by Enomoto Kasei Co., Ltd.), Plysurf A215C (manufactured by Daiichi Kogyo Seiyaku), Surf A217E (Daiichi Kogyo Seiyaku Co., Ltd.), Neoscore CM57 (Toho Chemical Co., Ltd.), Adeka Coal TS, Adeka Coal CS (Asahi Denka Co., Ltd.) and the like can be mentioned.

  Examples of fatty acid esters include dimethyl adipate, di-2-ethylhexyl adipate, diisobutyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol adipate, di-2-ethylhexyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate, Or sorbitan monocaprate, sorbitan dicaplate, sorbitan tricaplate, sorbitan monolaurate, sorbitan dilaurate, sorbitan trilaurate, sorbitan monomyristate, sorbitan dimyristate, as fatty acid ester consisting of dehydration condensate of sugar alcohol and fatty acid, Sorbitan trimistylate, sorbitan monopalmitate, sorbitan dipalmitate, sorbitan tripalmitate, sorbitan Bruno stearate, sorbitan distearate, and the like sorbitan tristearate.

  Examples of the polyhydric alcohol ester include glycerin ester such as monoglyceride and diglyceride which are esters of glycerin and fatty acid, or triglyceride such as glycerin diacetomonocaprylate, pentaerythritol ester and the like.

  Examples of polyvalent carboxylic acid esters include citric acid esters such as tributyl citrate and tributyl citrate.

The polar wax used in the present invention may be either a natural wax or a synthetic wax.
Examples of natural waxes include petroleum wax, montan wax, animal wax, and vegetable wax. The petroleum wax may be any non-polar wax having a structure mainly composed of saturated aliphatic hydrocarbons, such as paraffin wax and microwax, for example, these are modified into alcohol type wax by oxidation reaction or the like. If it is a thing, it may have polarity. Any montan wax having a structure having polarity by esterification or partial saponification may be used. Plant waxes include those containing a mixture of higher fatty acid and higher alcohol esters such as carnauba wax, rice wax and candelilla wax.
Synthetic waxes include fatty acids, fatty acid esters, fatty acid amides, etc., for example, vegetable oils such as castor oil, hydrogenated castor oil, jojoba oil, esterified products of sebacic acid, 12-hydroxystearic acid and esterified products and amide compounds thereof It may be a saponified product.
Since these waxes have polarity, they have the effect of maintaining translucency when mixed with a biodegradable polyester resin and being excellent in appearance. This effect is remarkable when polylactic acid is used as the biodegradable polyester resin.

  The content of the dispersant (D) is preferably 0.1 to 15 parts by mass, and 0.2 to 8 parts by mass with respect to 100 parts by mass in total of the biodegradable polyester resin (A) and the inorganic filler (B). Part is more preferable, and 0.5 to 5 parts by mass is more preferable. If the amount is less than 0.1 parts by mass, the dispersibility effect intended by the present invention cannot be obtained. If the amount exceeds 15 parts by mass, mechanical properties and moldability tend to be lowered. In order to improve the dispersibility of the inorganic filler, it is preferable to add 10 to 200 parts by mass of the dispersant (D) with respect to 100 parts by mass of the inorganic filler (B). These dispersants may be used alone or in combination of two or more.

<Phosphite Antioxidant (E)>
It is preferable to add a phosphite-based antioxidant to the resin composition of the present invention in order to increase its thermal stability and prevent a decrease in viscosity and a deterioration in color tone due to a decrease in molecular weight. Specifically, for example, tris (2,4-di-tert-butylphenyl) phosphite (IRGAFOS168 manufactured by Ciba Specialty Chemicals), bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (IRGAFOS12 manufactured by Ciba Specialty Chemicals), bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid (IRGAFOS38 manufactured by Ciba Specialty Chemicals), tetrakis (2, 4-di-tert-butylphenyl) [1,1-biphenyl] 4,4′-diylbisphosphonite (IRGAFOS P-EPQ manufactured by Ciba Specialty Chemicals), 3,9-bis (p-nonylphenoxy) -2,4,8,10-tetraoxa-3,9 -Diphosphaspiro [5,5] undecane (ADEKA STAB PEP-4C manufactured by ADEKA), O, O'-dialkyl (C = 8-18) pentaerythritol diphosphite (ADEKA STAB PEP-8, PEP-8W manufactured by ADEKA), manufactured by ADEKA ADK STAB PEP-11C, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (ADEKA STAB PEP24G manufactured by ADEKA), bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol- Di-phosphite (ADEKA STAB PEP36, PEP-36Z manufactured by ADEKA), 2,2′-methylenebis (4,6-di-tert-butylphenyl) -2-ethylhexyl phosphite (ADEKA STAB HP-10 manufactured by ADEKA), Tris ( 2,4-di tert-butylphenyl phosphite (ADEKA stub 2112 from ADEKA), 4,4'-butylidene-bis (6-tert-butyl-3-methylphenyl-ditridecyl phosphite) (ADEKA STAB 260 from ADEKA), hexaalkyl or [tri Alkyl (C = 8-18) tris (alkyl (C = 8,9) phenyl)] 1,1,3-tris (3-t-butyl-6-methyl-4-oxyphenyl) -3-methylpropanetriphos Phyto (Adeka ADEKA STAB 522A), di- or mono (dinonylphenyl) mono or di (p-nonylphenyl) phosphite (ADEKA ADEKA STAB 329K), trisnonylphenyl phosphite (ADEKA ADEKA STAB 1178), (1-methyl Ethylidene) -di-4,1-pheny -Tetra-alkyl (C = 12-15) phosphite (ADEKA stab 1500 from ADEKA), 2-ethylhexyl-diphenyl phosphite (ADEKA stub C from ADEKA), diphenylisodecyl phosphite (ADEKA STAB 135A from ADEKA), triisodecyl Examples thereof include phosphite (ADEKA STAB 3010 manufactured by ADEKA), triphenyl phosphite (TPP manufactured by ADEKA), hydrogenated bisphenol A pentaerythritol phosphite polymer (JPH3800 manufactured by Johoku Chemical Industry Co., Ltd.), among others, pentaerythritol diphosphite (PEP24G). ), Bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol di-phosphite (PEP36, PEP-36Z), tris (2,4-di-te) More preferred are rt-butylphenyl phosphite (2112), hydrogenated bisphenol A / pentaerythritol phosphite polymer (JPH3800), and the like. These may be used alone or in combination of two or more.

  Although content of a phosphite type antioxidant (E) is not specifically limited, 0.01-5 mass parts is with respect to a total of 100 mass parts of a biodegradable polyester resin (A) and an inorganic filler (B). preferable. If the amount is less than 0.01 part by mass, the suppression of coloring, heat resistance, and heat and humidity resistance, which are the objects of the present invention, cannot be obtained. If the amount exceeds 5 parts by mass, the physical properties of the resin composition are degraded due to decomposition of the phosphite organic compound.

<End-blocking agent (F)>
In order to improve the durability of the resin composition of the present invention, it is preferable to add a terminal blocking agent (F) to block the terminal of the resin. Examples of the terminal blocking agent include carbodiimide compounds, oxazoline compounds, isocyanate compounds, and epoxy compounds other than those specified in the present invention. Among these, carbodiimide compounds are particularly preferable. Specifically, N, N′-di-2,6-diisopropylphenylcarbodiimide (for example, EN-160 manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) is used as a monocarbodiimide having one carbodiimide group in the same molecule. Or, aromatic polycarbodiimide (for example, Stabuzol P, Stabuzol P-100 manufactured by Rheinhemy) or aliphatic (alicyclic) polycarbodiimide having two or more carbodiimide groups in the same molecule Examples thereof include carbodiimide (for example, LA-1 manufactured by Nisshinbo Industries, Ltd.). These end-blocking agents may be used alone or in combination of two or more. Although content of terminal blocker (F) is not specifically limited, 0.1-5 mass parts is preferable with respect to a total of 100 mass parts of biodegradable polyester resin (A) and an inorganic filler (B).

<Haze>
The resin composition of the present invention is excellent in the inorganic filler (B) by appropriately selecting the combination and addition amount of the biodegradable polyester resin (A), the inorganic filler (B), and the dispersant (D). It shows dispersibility, is excellent in appearance, and can have a haze of 50% or less when formed into a molded body having a thickness of 1 mm. If the haze is greater than this value, the product value may be low due to insufficient transparency or coarse aggregates even if the haze does not exceed this value. . In addition, haze here means the turbidity measured with the turbidimeter. The larger the haze, the stronger the turbidity, and the smaller the haze, the weaker the turbidity and the clearer it is. A molded body having a thickness of 1 mm, preferably having a haze of 50% or less as described above, more preferably having a haze of 45% or less, further preferably having a haze of 38% or less, and most preferably having a haze of 30%. It is as follows.

<YI>
In addition, the resin composition of the present invention is excellent in color tone and YI by appropriately selecting the combination and addition amount of the biodegradable polyester resin (A), the inorganic filler (B), and the dispersant (D). 30 or less. Preferably YI is 26 or less, more preferably 22 or less. Here, YI means yellowness calculated from tristimulus values. It shows that yellowness is so strong that YI is large, and yellowness is so weak that YI is small.

<MI>
The resin composition of the present invention preferably has a melt index (MI) measured under the conditions of 190 ° C. and 2.16 kgf of 0.1 to 10.0 (g / 10 minutes). When MI is less than 0.1 (g / 10 minutes), the fluidity necessary for molding cannot be obtained, and when it exceeds 10.0 (g / 10 minutes), the processing stability is lowered. However, it is difficult to control the shape such as thickness and width, and uneven thickness may occur in the final molded product. The MI is more preferably 0.5 to 8.0, and even more preferably 1.0 to 7.0. The MI of the resin composition can be adjusted to the above range by appropriately selecting the combination and addition amount of the biodegradable polyester resin (A), inorganic filler (B), and chain extender (C).

<Manufacturing method>
Next, the manufacturing method of the resin composition of this invention is demonstrated.
As a method of adding the inorganic filler (B) and the chain extender (C) to the biodegradable polyester resin (A), a method of adding at the time of polymerization of the biodegradable polyester resin (A), or adding at the time of melt kneading The method etc. are mentioned. Among them, the production process can be simplified, or it can be added at the time of melt-kneading because the thermal deterioration of the resin composition to which the inorganic filler (B) and the chain extender (C) are added is reduced as much as possible. preferable. In addition, when adding at the time of melt kneading, the inorganic filler (B) and the chain extender (C) are dry-blended in advance and then supplied to a general kneader, or a side feeder is used. Then, a method of adding from the middle of kneading, and a method of injecting liquid using a metering supply pump in the case of liquid are mentioned. The inorganic filler (B) and the chain extender (C) may be supplied at the same time or separately, but for the purpose of improving the dispersibility of the inorganic filler (B). Are preferably added to the resin at the same time or the chain extender (C) first.

  In the production of the resin composition of the present invention, other known crosslinking methods may be used in combination. Examples thereof include a method of adding a polyfunctional isocyanate compound, a (meth) acrylic acid ester compound and / or a peroxide as a crosslinking agent, or a method of crosslinking by electron beam irradiation. Among these, the method of adding a (meth) acrylic acid ester compound and / or peroxide is used as a cross-linking agent for the biodegradable polyester resin composition, and can promote crystallization and improve heat resistance. preferable.

  As the cross-linking agent, the reactivity with the polylactic acid resin is high, the monomer hardly remains, the toxicity is low, and the resin is less colored, so that it has two or more (meth) acryl groups in the molecule, Alternatively, a compound having one or more (meth) acryl groups and one or more glycidyl groups or vinyl groups is preferable. Specific compounds include glycidyl methacrylate, glycidyl acrylate, glycerol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, allyloxy polyethylene glycol monoacrylate, allyloxy (poly) ethylene glycol monomethacrylate, (poly) ethylene glycol Dimethacrylate, (poly) ethylene glycol diacrylate, (poly) propylene glycol dimethacrylate, (poly) propylene glycol diacrylate, (poly) tetramethylene glycol dimethacrylate, or alkylenes with various lengths of these alkylene glycols And the like, butanediol methacrylate, butanediol acrylate, and the like.

  0.05-10 mass parts is preferable with respect to 100 mass parts of biodegradable polyester resin (A), and, as for the addition amount of a crosslinking agent, More preferably, it is 0.05-1 mass part. If the amount is less than 0.05 parts by mass, crystallization cannot be promoted, and if the amount exceeds 10 parts by mass, the operability during kneading decreases.

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

  The amount of the peroxide added is preferably 0.1 parts by mass or more, more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the biodegradable polyester resin (A). If the amount is less than 0.1 parts by mass, the intended effect cannot be obtained, and if the amount exceeds 20 parts by mass, the operability during kneading may be reduced.

  In melt kneading, a general kneader such as a single screw extruder, a twin screw extruder, a roll kneader, or a Brabender can be used. In order to improve the dispersibility of additives, a twin screw extruder is used. It is preferable to use it.

The resin composition of the present invention includes a heat stabilizer, an antioxidant, a crystal nucleating agent, a pigment, a dye, a light resistance agent, a weather resistance agent, a flame retardant, a plasticizer, a lubricant, a release agent, as long as the effects of the present invention are not impaired. Molding agents, antistatic agents, organic fillers, dispersants other than those specified in the present invention, terminal blockers, fillers, and the like may be added.
For example, a hindered phenol compound, a benzotriazole compound, a triazine compound, a hindered amine compound, a sulfur compound, a copper compound, an alkali metal halide, or a mixture thereof may be used as a heat stabilizer or an antioxidant. it can. These additives are generally added during melt-kneading or polymerization.
Examples of the crystal nucleating agent include organic amide compounds, organic hydrazide compounds, carboxylic acid ester compounds, organic sulfonates, phthalocyanine compounds, melamine compounds, and organic phosphonates.
Organic fillers include polyester fiber, nylon fiber, acrylic fiber, cotton fiber, hemp fiber, bamboo fiber, wood fiber, kenaf fiber, jute fiber, banana fiber, coconut fiber, silk, wool, Angola, cashmere or camel. Animal fiber, paper powder, wood powder, bamboo powder, cellulose powder / fine particles, rice husk powder, fruit shell powder, chitin powder, chitosan powder, polysaccharides such as protein, monosaccharide, starch, rice husk, wood chip, okara, fir Examples thereof include organic fillers in the form of fibers, powders, or chips, such as shells, bran, waste paper grinding materials, clothing grinding materials, and modified products thereof.

  In addition, the resin composition of the present invention includes an aliphatic dicarboxylic acid, a copolymer thereof, polyester amide, polyester carbonate, polyamide (nylon), polyethylene, polypropylene, polybutadiene, polystyrene, AS, as long as the effects of the present invention are not impaired. Resin, ABS resin, poly (acrylic acid), poly (acrylic acid ester), poly (methacrylic acid), poly (methacrylic acid ester), polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, poly Non-biodegradable resins such as arylates and their copolymers may be added.

<Molded body>
The resin composition of the present invention can be formed into various molded products by known molding methods such as injection molding, blow molding, and extrusion molding. If the resin can be sufficiently melt-kneaded in the molding machine, the biodegradable polyester resin (A), the inorganic filler (B), and the chain extender (C) are added to the molding machine. The resin composition may be produced in a molding machine and subsequently molded. That is, the production of the resin composition and the production of the molded body may be continuously performed with a single molding machine.
As the injection molding method, in addition to a general injection molding method, a gas injection molding method, an injection press molding method, or the like can be adopted. The cylinder temperature at the time of injection molding needs to be equal to or higher than the melting point (Tm) or the flow start temperature of the resin composition, and is preferably in the range of 180 to 230 ° C, more preferably 190 to 220 ° C. If the molding temperature is too low, it tends to cause molding failure or overload of the apparatus due to a decrease in fluidity of the resin. On the other hand, when the molding temperature is too high, the biodegradable polyester resin is decomposed, and problems such as a decrease in strength and coloring of the molded product occur. On the other hand, the mold temperature is preferably (Tg−10 ° C.) or less when it is set to Tg (glass transition temperature) or less of the resin composition. Further, in order to promote crystallization of the resin composition for the purpose of improving rigidity and heat resistance, the mold temperature can be set to Tg or more and (Tm−30 ° C.) or less.

  Examples of the blow molding method include a direct blow method in which molding is performed directly from raw material chips, and an injection blow molding method in which blow molding is performed after a preformed body (bottom parison) is first molded by injection molding. In addition, any of a hot parison method in which blow molding is continuously performed after forming the preform, and a cold parison method in which the preform is cooled and taken out and then heated again to perform blow molding can be employed.

  As the extrusion molding method, a T-die method, a round die method, or the like can be applied. The extrusion molding temperature needs to be not less than the melting point (Tm) of the resin composition or not less than the flow start temperature, and is preferably in the range of 180 to 230 ° C, more preferably 190 to 220 ° C. If the molding temperature is too low, the operation tends to become unstable or overloaded. On the other hand, when the molding temperature is too high, the biodegradable polyester component is decomposed, causing problems such as a decrease in strength and coloring of the extruded product. Sheets, pipes and the like can be produced by extrusion molding.

Specific applications of the sheet or pipe obtained by the extrusion method include: deep drawing raw sheet, batch type foam raw sheet, credit cards and other cards, underlays, clear files, straws, agriculture and horticulture Hard pipes for use. Further, the sheet is further subjected to deep drawing such as vacuum forming, pressure forming, vacuum pressure forming, etc. to produce food containers, agricultural / horticultural containers, blister pack containers, press-through pack containers, etc. be able to.
The deep drawing temperature and the heat treatment temperature are preferably (Tg + 20 ° C.) to (Tg + 100 ° C.). If the deep drawing temperature is less than (Tg + 20 ° C.), deep drawing becomes difficult. Conversely, if the deep drawing temperature exceeds (Tg + 100 ° C.), the biodegradable polyester component is decomposed, resulting in uneven thickness or orientation failure. Impact resistance may decrease.
Forms of food containers, agricultural / horticultural containers, blister pack containers, and press-through pack containers are not particularly limited, but are deeply drawn to a depth of 2 mm or more in order to accommodate food, articles, medicines, and the like. It is preferable. Although the thickness of a container is not specifically limited, From a strong point, it is preferable that it is 50 micrometers or more, and it is more preferable that it is 150-500 micrometers.
Specific examples of food containers include fresh food trays, instant food containers, fast food containers, lunch boxes and the like. Specific examples of the agricultural / horticultural containers include a seedling pot. Specific examples of blister pack containers include packaging containers for various product groups such as office supplies, toys, and dry batteries in addition to food.

Other molded articles produced using the resin composition of the present invention include dishes such as dishes, bowls, bowls, chopsticks, spoons, forks, knives, containers for fluids, caps for containers, rulers, writing instruments, clears Office supplies such as cases and CD cases, triangular corners for kitchens, trash cans, washbasins, toothbrushes, combs, hangers and other daily necessities, various toys such as plastic models, resin parts for electrical appliances such as air conditioner panels and various cases, bumpers And automotive resin parts such as instrument panels and door trims.
In addition, although the form of the said container for fluids is not specifically limited, In order to accommodate a fluid, it is preferable to shape | mold to 20 mm or more in depth. Although the thickness of a container is not specifically limited, From a strong point, it is preferable that it is 0.1 mm or more, and it is more preferable that it is 0.1-5 mm. Specific examples of fluid containers include beverage cups and beverage bottles for dairy products, soft drinks and alcoholic beverages, soy sauce, sauces, mayonnaise, ketchup, temporary storage containers for seasonings such as edible oil, and shampoos. , Rinse containers, cosmetic containers, agricultural chemical containers, and the like.

The resin composition of the present invention may be a fiber. The production method is not particularly limited, but a method of melt spinning and stretching is preferred. The melt spinning temperature is preferably 160 ° C to 260 ° C. If it is less than 160 ° C., melt extrusion tends to be difficult. On the other hand, if it exceeds 250 ° C., decomposition tends to be remarkable, and it becomes difficult to obtain high-strength fibers. The melt-spun fiber yarn may be drawn at a temperature of Tg or higher so as to have a target fiber diameter.
The fibers obtained by the above method are used as clothing fibers, industrial material fibers, short fiber nonwoven fabrics, and the like.
The resin composition of the present invention can also be developed into a long-fiber nonwoven fabric. The production method is not particularly limited, and examples thereof include a method of depositing fibers obtained by spinning a resin composition by a high-speed spinning method and then forming a web using means such as hot pressing.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited only to the following examples.

<Evaluation method>
The method used for evaluation of the following Examples and Comparative Examples is as follows.
(1) Melt index (MI: Unit [g / 10 min])
According to JIS K7210, the measurement was performed under the conditions of D in Appendix A, Table 1 (190 ° C., 21.2 N [2.16 kgf]).
(2) Formability Using an injection blow molding machine (“ASB-50TH” manufactured by Nissei ASB Machine Co., Ltd., hot parison method), the resin composition is melted at a cylinder set temperature of 200 ° C. and filled into a 10 ° C. mold. Cooled for 10 seconds to obtain a 3.5 mm thick preform (bottom parison). This is heated with a heater at 120 ° C, then placed in a mold set at 20 ° C and blow-molded under conditions of pressure air of 3.5 MPa to produce a bottle container with an inner volume of 350 ml and an average thickness of 0.4 mm. The situation at the time of molding was confirmed. In the case of bottomed parison molding, drawdown occurred and uneven thickness was generated in the bottle after blowing, or when a bowl-shaped molding unevenness was confirmed on the shoulder, it was determined as poor moldability (x). Those having no drawdown or uneven thickness were evaluated as having good moldability (◯).
(3) Heat resistance The bottle obtained in (2) above was filled with water, sealed, and evaluated by the shape change after storage for 1 week in a hot air dryer at 55 ° C. Those in which the container did not deform were evaluated as good heat resistance (◯), and those in which deformation or distortion occurred were evaluated as poor heat resistance (×).
(4) Color tone (YI)
A color difference meter Z-Σ90 manufactured by Nippon Denshoku Industries Co., Ltd. was used. A 1.5 mm × 3 mm square pellet was filled into a 12 mm × 30 mmφ glass cell and measured.
(5) Transparency (haze)
According to JIS K-7136, it measured with respect to the 1 mm thick press sheet formed with the resin composition. That is, the tester industry company desktop test press machine was used for the resin composition, and it pressed at 190 degreeC for about 3 minutes, and produced the 1 mm-thick press sheet as a molded object. The press sheet was measured using an NDH-2000 type turbidity / cloudiness meter manufactured by Nippon Denshoku Industries Co., Ltd.
(6) Dispersibility (visual appearance)
Visual evaluation of the press sheet produced in the above (5) is performed, the gel or agglomerate is defective (x), the inorganic filler is uniformly dispersed is good (◯), and the agglomerate is hardly confirmed. The thing was made the best (◎).

<Raw material>
Next, various raw materials used in the following Examples and Comparative Examples are shown.
(1) Biodegradable polyester resin (A)
PLA1: Polylactic acid manufactured by NatureWorks, weight average molecular weight (MW) = 123,000, melting point = 166 ° C., D-form content = 1.3 mol%, MI = 8.0 (g / 10 min)
PLA2: Polylactic acid manufactured by NatureWorks, weight average molecular weight (MW) = 170,000, melting point = 169 ° C., D-form content = 1.3 mol%, MI = 3.5 (g / 10 min)

(2) Inorganic filler (B)
MEE: plate-like layered silicate. Swellable synthetic fluorinated mica in which interlayer ions are substituted with dihydroxyethylmethyldodecylammonium ions (Coop Chemical Co., Somasif MEE, average particle size 6.2 μm)
SBW: plate-like layered silicate. Montmorillonite with inter-layer ions substituted with dioctadecyldimethylammonium ions (Hojoen, Sven W)
-Talc: Plate-like inorganic filler. (Made by Hayashi Kasei, MW-HS-T, average particle size of 2.7 μm)

(3) Epoxy functional chain extender (C)
ADR-4300: Epoxy group-containing styrene-acrylic copolymer. Epoxy equivalent = 445 g / mol, weight average epoxy functional group number (EFW) = 12.3, glass transition temperature = 56 ° C., weight average molecular weight (Mw) = 5,500. (BASF, JONCRYL-ADR4300)
ADR-4368: Epoxy group-containing styrene-acrylic copolymer. Epoxy equivalent = 285 g / mol, weight average epoxy functional group number (EFW) = 23.9, glass transition temperature = 54 ° C., weight average molecular weight (Mw) = 6,800. (BASF, JONCRYL-ADR4368)

(4) Low molecular weight epoxy compound / EX-810: ethylene glycol diglycidyl ether. Epoxy equivalent = 113 g / mol, weight average epoxy functional group number (EFW) = 1.5, liquid, molecular weight = 174 g / mol. (Nagase ChemteX, Denacol EX-810)

(5) Dispersant (D)
-Polyether phosphate ester: Disparon DA375 (manufactured by Enomoto Kasei)
Sorbitan fatty acid ester: sorbitan tristearate (Riken Vitamin Co., Poem S-65V)
・ Glycerin fatty acid ester: Glycerin acetocaprylate (Riken Vitamin Co., Riquemar PL-019)

(6) Phosphite antioxidant (E)
PEP36: Bis (2,6-di-tert-butyl-4-methylphenyl) -pentaerythritol-di-phosphite (manufactured by ADEKA, ADK STAB PEP36)

(7) Endblocker (F)
EN160: N, N′-di-2,6-diisopropylphenylcarbodiimide, purity 98.8% (manufactured by Matsumoto Yushi Seiyaku, EN-160)
LA-1: Polycarbodiimide (Nisshinbo, Carbodilite LA-1)

Example 1
99 parts by mass of PLA1, 1 part by mass of MEE and 0.5 parts by mass of ADR-4300 were dry blended, and the above extruder (Ikegai PCM-30 type twin screw extruder, screw diameter = 30 mmφ) , Average groove depth = 2.5 mm) was melt kneaded at 190 ° C. and screw rotation speed 150 rpm, extruded, processed into a pellet, and dried to obtain a resin composition.
MI and YI were measured using the pellets of the obtained resin composition. The pellets were molded into a press sheet and evaluated for transparency and dispersibility. Further, blow bottles were molded and evaluated for moldability and heat resistance. The evaluation results are shown in Table 1.

Examples 2-10
A resin composition was obtained and evaluated in the same manner as in Example 1 except that the composition of the resin composition was changed as shown in Table 1. The results are shown in Table 1.
Further, using the resin composition of Example 9, a high temperature mold was blow molded in the same manner except that the final mold was set to 120 ° C., and a bottle container having an internal volume of 350 ml and an average thickness of 0.4 mm was obtained. The condition at the time of fabrication and molding was confirmed.

Comparative Examples 1 and 2
Using only the biodegradable polyester resin (A), a resin composition was obtained and evaluated. The results are shown in Table 1.

Comparative Example 3
The same kneading was performed without adding the inorganic filler (B) to obtain a resin composition for evaluation. The results are shown in Table 1.

Comparative Example 4
The same kneading was performed except that EX-810 was used instead of the chain extender (C) to obtain a resin composition for evaluation. The results are shown in Table 1.

Comparative Examples 5 and 6
The same kneading was performed except that the amount of the chain extender (C) added was changed, and a resin composition was obtained for evaluation. The results are shown in Table 1.

Comparative Example 7
Except that the chain extender (C) was not added, the same kneading was carried out to obtain a resin composition for evaluation. The results are shown in Table 1.

Since the resin compositions of Examples 1 to 10 contained an appropriate chain extender (C), the melt viscosity was improved from the raw material biodegradable polyester resin (A), and the moldability was good. It was. Furthermore, since the inorganic filler (B) was added, the heat resistance of the obtained bottle was also good.
Since the dispersing agent (D) is added to the resin compositions of Examples 2 to 10, the aggregates are few and show a good appearance. In particular, the resin compositions of Examples 2 to 9 are almost aggregated. The object was not visible and had good transparency.
Since the phosphite antioxidant (E) is added to the resin compositions of Examples 7 to 8, YI is lower than that of the resin composition to which no antioxidant is added (Examples 5 to 6). It was possible to improve the appearance. In addition, since the end blocker (F) was added to the resin composition of Example 9, the MI was lower than that of the resin composition without the end blocker added (Example 8). It was possible to increase the viscosity while suppressing the decrease in molecular weight due to.
When the resin composition of Example 9 was blow molded using a high temperature mold, the heat resistance was improved by the inorganic filler (B), and the viscosity was appropriately adjusted by the chain extender (C). Therefore, a bottle having a good shape with no drawdown or uneven thickness and no heat shrinkage due to a high temperature mold was obtained. Moreover, since the dispersing agent (D) was added, the dispersibility of the inorganic filler (B) was good, and the transparency of the bottle body was good. Furthermore, since the antioxidant (E) and the end-capping agent (F) were added, the color tone was also good.

  On the other hand, none of the resin compositions of Comparative Examples 1 to 7 had good moldability, heat resistance, and appearance. That is, since Comparative Examples 1-3 did not contain the inorganic filler (B), heat resistance was not obtained. In Comparative Example 4, since the chain extender (C) was not appropriate, the melt viscosity was not improved and the moldability was poor. Moreover, since the obtained bottle had uneven thickness, heat resistance was insufficient. In Comparative Example 5, since the amount of the chain extender (C) added was small, the melt viscosity was hardly improved and the moldability could not be improved. In Comparative Example 6, the amount of the chain extender (C) added was too large, resulting in excessively high viscosity, and MI measurement and blow molding could not be performed. In Comparative Example 7, because the chain extender (C) was not added, the moldability could not be improved, and as in Comparative Example 4, both the moldability and heat resistance were insufficient.

Claims (12)

  A polyester resin composition comprising a biodegradable polyester resin (A), an inorganic filler (B), and an epoxy functional chain extender (C) having a weight average epoxy functional group number of 3 or more, The mass ratio (A / B) of A) and (B) is 99.9 / 0.1 to 80/20, and the content of (C) is a total of 100 parts by mass of (A) and (B). The polyester resin composition is characterized by being 0.05 to 10 parts by mass.   The polyester resin composition according to claim 1, wherein the biodegradable polyester resin (A) contains 50% by mass or more of polylactic acid.   The polyester resin composition according to claim 1 or 2, wherein the inorganic filler (B) is a plate-like inorganic filler.   The chain extender (C) has a weight average number of epoxy functional groups of 3 to 30, a glass transition temperature of 0 to 70 ° C., an epoxy equivalent of 180 to 2800 g / mol, and a weight average molecular weight of 2,000 to 2,000. It is 40,000, The polyester resin composition in any one of Claims 1-3 characterized by the above-mentioned.   The chain extender (C) is a copolymer formed from an epoxy-functional (meth) acrylic monomer and a non-functional (meth) acrylic monomer and / or a styrene monomer. A polyester resin composition according to claim 1.   It contains at least one dispersant (D) selected from polyether phosphate ester, fatty acid ester, polyhydric alcohol ester, polyvalent carboxylic acid ester, and polar wax, and the content thereof is (A) and ( It is 0.1-15 mass parts with respect to a total of 100 mass parts of B), The polyester resin composition in any one of Claims 1-5 characterized by the above-mentioned.   The phosphite antioxidant (E) is contained, and the content thereof is 0.01 to 5 parts by mass with respect to 100 parts by mass in total of (A) and (B). The polyester resin composition in any one of 1-6.   The terminal blocking agent (F) is contained, and the content thereof is 0.1 to 5 parts by mass with respect to 100 parts by mass in total of (A) and (B). A polyester resin composition according to any one of the above.   The polyester resin composition according to claim 1, wherein the melt index (MI) measured at 190 ° C. and 2.16 kgf is 0.1 to 10.0 (g / 10 minutes). .   10. The polyester resin composition according to claim 1, wherein the haze is 50% or less when YI is 30 or less and the molded product has a thickness of 1 mm.   The polyester resin according to any one of claims 1 to 10, wherein an inorganic filler (B) and a chain extender (C) are added to the biodegradable polyester resin (A) during melt-kneading. A method for producing the composition.   A molded article comprising the polyester resin composition according to any one of claims 1 to 10.