JP2007246624A - Aliphatic polyester resin extrusion-molded sheet excellent in heat resistance and container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aliphatic polyester resin sheet excellent in heat resistance and a molded article thereof. <P>SOLUTION: This sheet is obtained by extrusion-molding a resin composition comprising the following (1), (2) and (3) components: (1) an aliphatic polyester resin composition, (2) a nonionic surfactant and (3) talc. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aliphatic polyester resin extruded sheet having an excellent crystallization rate and a molded container obtained therefrom.

Recently, from the viewpoint of environmental conservation, an aliphatic polyester resin having biodegradability that is decomposed by microorganisms existing in soil or water has attracted attention. In particular, in the food packaging field and the agricultural material field, the usefulness of aliphatic polyester films and sheets and molded containers obtained therefrom is increasing.
Among these aliphatic polyester resins, polylactic acid is most useful because it can be produced from renewable plant resources such as corn, can be mass-produced, is inexpensive, and can be melt-molded. However, compared with non-biodegradable general-purpose resins such as polyethylene, polypropylene, and polyethylene terephthalate, the crystallization rate of polylactic acid is remarkably slow, so that it actually behaves like an amorphous resin. That is, since it softens rapidly and extremely near the glass transition temperature, it cannot be used for a molded container or a container for hot water that contains heated food in a microwave oven or the like. In addition, when a polylactic acid sheet or its molded container is stored or transported, it is often recognized that problems such as deformation and fusion occur at the time of storage or inside a truck, train or ship during transport.

In order to solve these problems, efforts have been made to improve the crystallization speed of aliphatic polyester resins represented by polylactic acid.
As a known technique for a long time, it has been known to add an inorganic filler such as talc, mica, glass fiber, etc. However, if the inorganic filler is not added in a large amount, the effect does not appear, so the transparency of the resin itself is There was a problem that the specific gravity increased as it was made.

  Therefore, in Patent Document 1, a higher fatty acid bisamide is added to polylactic acid to prevent blocking and formability, and in Patent Document 2, a thermoplastic polymer composition containing polylactic acid as a main component. Imparting releasability and molding processability by adding a fatty acid amide to the resin, and in Patent Document 3, adding a layered clay mineral organized with an organic onium salt having a hydroxyl group to a biodegradable resin Thus, a technique for providing a biodegradable resin composite material excellent in elastic modulus and crystallization speed is disclosed. Patent Document 4 discloses automobile parts obtained from a resin composition containing a lactic acid-based resin and an aliphatic (or aromatic) polyester having an Tg of 0 degrees or less, an inorganic filler, and a hydrolysis inhibitor, and home appliances. It is disclosed that parts are excellent in physical properties and recyclability. Patent Document 5 shows that a composition having excellent heat resistance, mechanical strength, and foam processing suitability can be obtained by including a biodegradable polyester resin, a methacrylic acid ester compound, and a layered silicate. Yes. Patent Document 6 discloses that a composition having a high crystallization speed and a high heat resistance temperature of a molded product is obtained by adding polylactic acid to a layered silicate modified with an organic onium salt, an amide compound, and talc. It has been shown that

However, in the case of the above prior art, although a certain degree of improvement in the crystallization speed is recognized, the effect is not yet sufficient. Therefore, in order to obtain a molded body having a sufficient crystallinity, the molding time is remarkably reduced. There is a problem that it takes a long time or heat treatment is required after molding. Prolonging the molding time causes a significant reduction in productivity, which is an industrially fatal defect. On the other hand, when heat treatment is performed after molding, there is a problem that the molded body is deformed during the heat treatment, and the fact is that it is not put into practical use.
Japanese Patent Laid-Open No. 6-299054 JP-A-8-27363 JP 2003-73538 A JP 2003-128900 A International Publication No. 04/099315 Pamphlet JP 2004-51667 A

  An object of this invention is to obtain the aliphatic polyester resin extrusion molding sheet | seat and molding container excellent in heat resistance.

As a technique for solving these problems, the inventors of the present invention have an aliphatic polyester resin composition containing the following three components that is excellent in crystallization speed and has extremely high heat resistance in a very short molding time in injection molding and the like. It has been found that a molded body having can be made.
1. Aliphatic polyester Talc 3. Nonionic surfactant A container that exhibits high heat resistance in a very short cycle time when a sheet obtained by extrusion molding from these compositions is further molded into a container by press molding, vacuum molding, pressure molding, or vacuum / pressure molding. It was found that can be obtained. In that case, (1) using a material having a specific structure as a nonionic surfactant (2) adding a polyester resin having a specific glass transition point (Tg) as a flexible resin, The present inventors have found that the molded body has excellent impact resistance and molding processability, and that the container obtained by vacuum-pressure forming or the like exhibits excellent heat resistance.

That is, the present invention is as follows.
1. Aliphatic polyester resin composition comprising a mixed composition comprising aliphatic polyester 60.0-99.9% by weight, talc 0.05-20% by weight, and nonionic surfactant 0.05-20% by weight Extruded sheet consisting of
2. From an aliphatic polyester resin composition to which 0.01 to 10 parts by weight of an organically modified layered silicate obtained by treating a layered silicate with an organic onium salt is further added to 100 parts by weight of the mixed composition 2. The extruded sheet according to 1.
3. 1 or 2 which consists of an aliphatic polyester resin composition which contains 0.01-30 weight part of soft resins whose glass transition point (Tg) is 0 degrees C or less further with respect to 100 weight part of said mixed compositions. Extruded sheet.
4). The nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ether, difatty acid polyoxyethylene glycol, mono fatty acid polyoxyethylene sorbitan, and fatty acid polyoxyethylene glyceryl, polyglycerin fatty acid ester, glycerin fatty acid ester. The extruded sheet according to any one of 1 to 3, which is at least one compound.

5). The extruded sheet according to any one of 1 to 3, wherein the nonionic surfactant is at least one compound selected from the group consisting of polyoxyethylene alkyl ether, fatty acid polyoxyethylene glyceryl, and polyglycerol fatty acid ester.
6). The extrusion molded sheet according to any one of 1 to 3, wherein the nonionic surfactant is fatty acid polyoxyethylene glyceryl.
7). The extruded sheet according to any one of 1 to 6, wherein the aliphatic polyester is polylactic acid.
8). The extrusion molded sheet according to any one of 1 to 7, wherein the aliphatic polyester resin composition contains a carboxyl group terminal blocking agent of an aliphatic polyester.
9. A container obtained by molding the extruded sheet according to any one of claims 1 to 8 by any one of press molding, vacuum molding, pressure molding, and vacuum / pressure molding.

  When a sheet obtained from the aliphatic polyester resin composition of the present invention is molded by a technique such as vacuum and compressed air, a container having excellent heat resistance can be obtained in a very short molding cycle.

The present invention will be specifically described below, particularly focusing on preferred forms thereof.
The aliphatic polyester resin in the present invention is not particularly limited, but an aliphatic polyester resin having biodegradability is preferably used. Such aliphatic polyesters include polylactic acid, polybutylene succinate, polyethylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, polycaprolactone, polybutylene succinate carbonate, polyglycolic acid, polyvinyl alcohol, polyester amide And polysaccharides such as polyester carbonate, polyketone and starch. In the present invention, these resins may be used alone, or may be used in combination by copolymerizing or mixing a plurality of resin components.

  In the present invention, among the above-mentioned aliphatic polyester resins, polylactic acid which is excellent in mechanical strength and transparency and rich in versatility is preferably used. The weight average molecular weight of polylactic acid is not particularly limited, but is preferably 50,000 or more, and more preferably 100,000 or more. When polylactic acid is a copolymer of a D-form lactic acid raw material and an L-form lactic acid raw material, the content of one of the D-form lactic acid raw material and the L-form lactic acid raw material is preferably 90 mol% or more, and 95 mol % Or more is more preferable, and 98 mol% or more is more preferable. The polylactic acid may be any polymer of D-form, L-form, and DL-form. In addition, a blend of polylactic acid whose main component is D-lactic acid and polylactic acid whose main component is L-lactic acid at an arbitrary ratio may be used.

The melting point of the polylactic acid resin is not particularly limited, but is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, and particularly preferably 160 ° C. or higher. The melting point of the polylactic acid resin is usually increased by increasing the optical purity of the lactic acid component, and the polylactic acid resin having a melting point of 120 ° C. or higher contains 90 mol% or more of the L form or 90 mol% or more of the D form. In addition, a polylactic acid resin having a melting point of 150 ° C. or higher can be obtained by containing 95 mol% or more of L form or 95 mol% or more of D form.
Specific examples of these polylactic acids include a product name, NatureWorks, Mitsui Chemicals, a trade name, Lacia, Toyota Motor Corp., a trade name, U'z, and the like, manufactured by Nature Works.

  Next, talc in the present invention will be described. The type of talc is not particularly limited, but the smaller the average particle size, the better. Preferably it is 15 microns or less, More preferably, it is 5 microns or less, More preferably, it is 2 microns or less. Examples of talc having a particle size of 15 microns or less include Fuji Talc Co., Ltd., trade names, LMP100, LMP200, Matsumura Sangyo Co., Ltd., trade names, HiFiller 5000PJ, etc. Among them, HiFiller 5000PJ has a small particle size and is an aliphatic polyester in the present invention. The effect of increasing the crystallization speed of the resin composition is strong. Further, such talc may be subjected to a surface treatment in order to improve adhesiveness with the resin. Such talc is commercially available and is sold by Nippon Talc Co., Ltd., Fuji Talc Industry Co., Ltd., and the like.

  The nonionic surfactant in the present invention is composed of a hydrophilic part and a hydrophobic part. Examples of the structure of the hydrophobic portion include saturated or unsaturated hydrocarbon groups typified by lauryl group, cetyl group, oleyl group, isostearyl group, stearyl group, etc. It may have, and may be epoxidized. Further, it may be derived from fatty acids purified from natural products such as beef tallow and coconut oil. Further, the structure may have a cycloalkane structure such as rosin or lanolin, an aromatic structure such as benzene or phenol, or an ester structure such as acrylate or methacrylate. Moreover, you may have carboxylic acid like betaines. As the structure of the hydrophilic portion, it is preferable to have any one of a hydroxyl group, a hydroxyalkylene, a polyoxyalkylene, a polyglycerin structure, a carboxyl, an ester, an amine, an amide, and an alkanol. More preferred are hydroxyalkylene and polyoxyalkylene structures.

  Examples of nonionic surfactants that satisfy these conditions are polyoxyethylene stearyl ether, polyoxyethylene dodecyl ether, polyoxyethylene monolaurate, polyoxyethylene octylphenyl ether, polyoxyethylene lanolin ether, polyoxyethylene Rosin ester, polyoxyethylene stearic acid ester, difatty acid polyoxyethylene glycol, mono fatty acid polyoxyethylene sorbitan, fatty acid polyoxyethylene glyceryl (polyoxyethylene glycerin fatty acid ester), glycerin fatty acid ester, polyglycerin fatty acid ester, hydroxystearic acid Octyl, cholesteryl hydroxystearate, stearyl diethanolamine, dodecyl diethanolamine, etc. It is below. Specific examples of the nonionic surfactant having a structure in such a range include products manufactured by Nippon Emulsion Co., Ltd., trade names, EMALEX 602, EMALEX 703, EMALEX 805, EMALEX 1605, EMALEX 600di-S, Examples include Emarex series such as Rex ET-8020 and Emarex GWIS-120, manufactured by Riken Vitamin Co., Ltd., trade names, Riquemar, and Poem series.

Among these nonionic surfactants, polyoxyethylene alkyl ether, difatty acid polyoxyethylene glycol, mono fatty acid polyoxyethylene sorbitan, fatty acid polyoxyethylene glyceryl, glycerin fatty acid ester, polyglycerin fatty acid ester are the fats in the present invention. The effect of improving the crystallization rate of the group polyester resin composition is high.
Among these, polyoxyethylene alkyl ether, fatty acid polyoxyethylene glyceryl, and polyglycerin fatty acid ester are preferable. These polyoxyethylene alkyl ether, fatty acid polyoxyethylene glyceryl, and polyglycerin fatty acid ester will be described in more detail.

Among the polyoxyethylene alkyl ethers represented by the following formula (1), a polyoxyethylene alkyl ether in which the carbon chain length of the alkyl group R is 12 to 18 carbon atoms is preferable. As the structure of the hydrocarbon moiety (R), both saturated and unsaturated can be used. As the carbon chain length, polyoxyethylene stearyl ether having 18 carbon atoms is more preferable. Examples of these include trade name, EMALEX 602, EMALEX 610, EMALEX 620, EMALEX 630, EMALEX 640, and the like. For the hydrophilic part, the number of added moles (n) of polyoxyethylene is preferably about 2 or more and 50 or less. More preferably, it is about 5-25, More preferably, it is about 20. Moreover, it is better that the terminal hydroxyl group is not blocked. An example of this nonionic surfactant is the trade name Emalex 620.
R—O— (CH ₂ CH ₂ O) _n H (1)

  The fatty acid polyoxyethylene glyceryl represented by the following formula (2) will be described. As the structure of the hydrocarbon portion (R) of the fatty acid, both saturated and unsaturated can be used. The fatty acid has a carbon chain length (R) of preferably 11 to 17, and particularly preferably polyoxyethylene glyceryl stearate having 17 carbon atoms. In this case, stearic acid may have an iso structure. Further, among the three hydroxyl groups, tri-fatty acid polyoxyethylene glyceryl in which all fatty acids are esterified or di-fatty acid polyoxyethylene glyceryl in which two are fatty acid esters can also be used. Mono fatty acid polyoxyethylene glyceryl remaining as it is is preferable. The addition mole (a + b + c) of polyoxyethylene is preferably 3 or more and 60 or less, more preferably 5 or more and 30 or less, and even more preferably about 20. An example of this is Emalex GWIS-120.

  About the polyglycerol fatty acid ester shown in following formula (3), both saturated and unsaturated can be used as a structure of the hydrocarbon part (R) of a fatty acid. The carbon chain length (R) of the fatty acid is preferably 11 to 17, and polyglycerol stearic acid ester having 17 carbon atoms is particularly preferable. About the polymerization degree n of polyglycerol, about 1-30 are preferable. More preferably, it is 10-20. Examples of this structure include the product name, Poem J-0081HV, manufactured by Riken Vitamin Co., Ltd.

These polyoxyethylene alkyl ethers, fatty acid polyoxyethylene glyceryl, and polyglycerin fatty acid esters not only have a high crystallization promoting effect, but are also excellent in processability of extrusion sheet molding and vacuum / pressure forming of the obtained sheet. Therefore, it is preferably used in the present invention. Of these, fatty acid polyoxyethylene glyceryl is preferable.
The ratio of each component in the aliphatic polyester resin composition of the present invention is 60 to 99.9% by weight of aliphatic polyester resin, non-ionic surfactant based on the total amount of aliphatic polyester, talc and nonionic surfactant. The ionic surfactant is preferably 0.05 to 20% by weight and talc 0.05 to 20% by weight. More preferably, they are 80-98.0 weight% of aliphatic polyester resin, 1.0-10 weight% of nonionic surfactant, and 1.0-10.0 weight% of talc, More preferably, aliphatic polyester resin 90 0.095.0% by weight, nonionic surfactant 2.0-4.0% by weight, talc 3.0-6.0% by weight.

  When the nonionic surfactant is less than 0.05% by weight, the crystallization rate is not improved, and the finally obtained aliphatic polyester resin composition has low heat resistance. On the other hand, when there are more nonionic surfactants than 20 weight%, a nonionic surfactant may bleed out from a molded object and an external appearance may be impaired. When talc is less than 0.05% by weight, the crystallization rate is not improved, and the finally obtained aliphatic polyester resin composition has low heat resistance. On the other hand, when talc is more than 20% by weight, the resulting aliphatic polyester resin composition may become brittle and impact strength may be reduced.

  Examples of layered silicates in the present invention include clay minerals such as pyrophyllite, smectite, vermiculite, mica, etc., and these are known methods such as hydrothermal methods, even if they are purified from naturally occurring ones. It may be synthesized by. Specific examples of the layered silicate used in the present invention include montmorillonite, hectorite, beidellite, saponite, and synthetic fluorinated mica. For example, examples of montmorillonite include Southern Clay, trade name, CloisiteNa, Kunimine Kogyo, trade name, Kunipia RG, etc. Examples of synthetic fluorinated mica include Corp Chemical, trade name, Somasif ME100, etc. Can be mentioned.

  The organically modified layered silicate in the present invention is obtained by organicizing a layered silicate by exchanging a cation existing between layers of the layered silicate with an organic onium salt. An organic onium salt refers to a salt formed by the coordination of an organic substance component and a Lewis base, and a quaternary ammonium salt, an organic phosphonium salt, an organic sulfonium salt, and the like correspond thereto. In addition, organic amine compounds that exhibit cationic properties when dissolved in an acidic polar solvent, zwitterionic compounds, and the like correspond to these, but quaternary ammonium salts as shown in the following formula (4), or cationization The organic amine compound is preferably used.

In the formula, each of R1, R2, R3, and R4 is hydrogen or a saturated or unsaturated hydrocarbon represented by methyl, ethyl, lauryl, cetyl, oleyl, isostearyl, stearyl and the like. The hydrocarbon may be linear or branched, and may be epoxidized. The hydrocarbon chain may be derived from natural products such as beef tallow and coconut oil. Further, it may have a cycloalkane, an aromatic ring or an ester structure, and may have a carboxylic acid like betaines. Moreover, it is preferable that at least one of the hydrocarbon chains of R1 to R4 has 10 or more carbon atoms. When the number of carbon atoms constituting the longest hydrocarbon chain is less than 10, the affinity between the organically modified layered silicate and the aliphatic polyester is insufficient, and sufficient physical properties may not be improved. X ⁻ represents an anion and is not particularly limited, but mainly corresponds to a halide ion such as a chloride ion or a bromide ion.

  Among organic layered silicates, the organic onium salt preferably contains a hydroxyl group. The hydroxyl group may exist in the form of a hydroxyalkylene group, a polyoxyalkylene group or the like. The position of the hydroxyl group in the organic onium salt in the present invention is not particularly limited, but when an ammonium salt, an amine or the like is used as the organic onium salt, a hydroxyl group bonded in the vicinity of the nitrogen atom is preferably used. Examples of these include cured tallow diethanolamine, dodecyl diethanolamine, methyl octadecyl dihydroxyethyl ammonium chloride, and methyl dodecyl dihydroxypropyl ammonium chloride. Examples of the organic ammonium compound containing a polyoxyalkylene group include polyoxyethylene octadecyldimethylammonium chloride and methyldipolyoxypropylene octadecylammonium chloride. Any number of moles of these polyoxyalkylene groups can be used.

Examples of organic amines or organic onium salts having such a structure include Aoki Yushi Kogyo Co., Ltd., trade names, BROWNON S-202, BROWNON S-204, BROWNON S-205T, BROWNON L-202, manufactured by Lion Akzo Corporation. , Trade name, Esomin C / 12, Esomin HT / 12, Esomin 18/12, Esocard C / 25, Esocard C / 12, Esocard, manufactured by Kao Corporation, trade names, Amphitol 20BS, Amphitol 24B, Amphitol 86B, etc. .
Aliphatic polyester resin compositions containing organically modified layered silicates obtained by treatment with organic onium salts containing these hydroxyl groups promote crystallization of aliphatic polyester resins when subjected to crystallization treatment And there exists an effect (Template effect) which improves a crystallinity degree, and the heat resistance of the molded object obtained as a result improves. Moreover, there exists an effect that the rigidity of a molded object improves by containing these organic-ized layered silicate.

In the present invention, the method for synthesizing the organically modified layered silicate is not particularly limited, and a known method can be used. Specific examples of these organically modified layered silicates include the product names, Cloisite 15A, Cloisite 20A, Cloisite 25A, manufactured by Corp Chemical, trade names, Somasif MAE, MTE, etc., manufactured by SouthernClay. Specific examples of the organically modified layered silicate treated with an organic onium salt containing a hydroxyl group include Southern Clay, trade name, Cloisite 30B, Coop Chemical, trade name, Somasif MEE, Somasif MPE, and the like. It is done.
The addition amount of these organically modified layered silicates is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the mixed composition composed of aliphatic polyester, talc and nonionic surfactant. . When the organic layered silicate is less than 0.01 part by weight, the effect of improving the crystallinity of the resulting aliphatic resin composition tends to be small. On the other hand, when the amount is more than 10 parts by weight, the resulting aliphatic polyester resin composition may become brittle and impact strength may be reduced.

In the present invention, (1) improvement of process suitability at the time of sheet molding (2) specific glass transition temperature (Tg) and melting point (Tm) in order to improve the impact resistance and molding processability of the obtained sheet and its molded product It is preferable to add a flexible resin having an aliphatic polyester resin composition. In particular, when the aliphatic polyester which is a main component in the composition is polylactic acid, the effect is great.
The glass transition temperature (Tg) of the flexible resin in the present invention is 0 ° C. or lower, more preferably −20 ° C. or lower. When the glass transition temperature is higher than 0 ° C., the impact resistance improving effect tends to be insufficient. When the Tg of the aliphatic polyester as the main component is 0 ° C. or higher, the effect of adding the flexible resin is increased.
The melting point of the flexible resin is preferably higher than the glass transition temperature (Tg) of the aliphatic polyester resin and lower than the melting point (Tm). The case where the aliphatic polyester resin is polylactic acid will be described. A preferable melting point range of the flexible resin is 80 ° C. or higher and 180 ° C. or lower. If it is lower than this temperature, the heat resistance of the molded product may be insufficient.

  Although there are many flexible resins that satisfy such conditions, in the present invention, it is preferable to use a flexible resin having biodegradability as in the case of the aliphatic polyester as the main component. More preferably, it is a biodegradable polyester resin. The biodegradable thermoplastic resin is a degree of biodegradation measured in accordance with at least one of JIS K6950 (2000), JIS K6951 (2000), JIS K6953 (2000), OECD 301C or ISO 17556. It is a thermoplastic resin that is 60% (theoretical value) or more within the legal description period. Specific examples thereof include polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate carbonate, polybutylene adipate terephthalate, polybutylene succinate adipate terephthalate, polyhydroxyalkanoate (PHA) resin. can give. Particularly preferred are polybutylene adipate terephthalate and polybutylene succinate adipate terephthalate.

  These flexible resins are preferably contained in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of the mixed composition composed of aliphatic polyester, talc and a nonionic surfactant. If the amount is less than 0.01 parts by weight, the effect of improving the moldability is small. Conversely, if the amount is more than 30 parts by weight, the heat resistance of the sheet and the container may be impaired.

  In the composition of this invention, it is preferable to mix | blend the carboxyl group terminal blocker of aliphatic polyester. By blocking the carboxyl group terminal of aliphatic polyester, the molecular weight fall of the molded object obtained can be suppressed and durability can be improved. Moreover, there is also an effect of improving molding stability by suppressing hydrolysis, transesterification reaction and the like during sheet molding. The carboxyl group end-blocking agent used in the present invention is not particularly limited as long as it is a compound capable of blocking carboxyl end groups such as aliphatic polyesters in the present invention, particularly polylactic acid. In the present invention, the carboxyl group end-capping agent not only blocks the end of the aliphatic polyester resin, but also lactic acid produced by thermal decomposition or hydrolysis of an organic filler such as aliphatic polyester or nonionic surfactant. The carboxyl group of acidic low molecular weight compounds such as formic acid can also be blocked. Further, the end-capping agent is more preferably a compound that can also block the hydroxyl end where an acidic low molecular weight compound is generated by thermal decomposition.

As such a carboxyl group terminal blocking agent, it is preferable to use at least one compound selected from an epoxy compound, an oxazoline compound, an oxazine compound, and a carbodiimide compound, and among them, an epoxy compound and / or a carbodiimide compound are preferable.
As an epoxy compound that can be used as a carboxyl group terminal blocking agent in the present invention, a glycidyl ether compound, a glycidyl ester compound, a glycidyl amine compound, a glycidyl imide compound, and an alicyclic epoxy compound can be preferably used. As other epoxy compounds, epoxy-modified fatty acid glycerides such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized whale oil, phenol novolac type epoxy resins, cresol novolac type epoxy resins and the like can be used. Specific examples of the epoxy end-capping agent include Toagosei Co., Ltd., trade name, ARUFON, manufactured by NOF Corporation, trade name, Bremer CP50S (BLCPS), manufactured by Nagase Kasei Co., Ltd., trade name, Denacol EX-711, etc. Can be mentioned.

Examples of the oxazoline-based end-blocking agent that can be used as the carboxyl-group end-blocking agent in the present invention include products manufactured by Nippon Shokubai Co., Ltd., trade name, Epocross RPS1005, Takeda Pharmaceutical Co., Ltd. 2,2′-m-phenylenebis (2-oxazoline) ) And the like.
The carbodiimide compound that can be used as a carboxyl group end-blocking agent in the present invention is a compound having at least one carbodiimide group represented by (—N═C═N—) in the molecule. In the presence of a catalyst, the organic isocyanate can be heated and produced by a decarboxylation reaction. As an example of a carbodiimide type | system | group terminal blocker, the Nisshinbo Co., Ltd. make, a brand name, carbodilite LA1, HMV-8CA etc. are mentioned.

  Although the said carboxyl group terminal blocker can select and use 1 type or 2 or more types of compounds arbitrarily, the combination containing an epoxy compound and / or a carbodiimide compound is used preferably. The carboxyl group end-blocking agent in the present invention may be added to the aliphatic polyester resin composition in an appropriate amount depending on the use, but the mixed composition consisting of approximately aliphatic polyester, talc and nonionic surfactant is 100 weights. Parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, and still more preferably 0.1 to 3 parts by weight. As an addition method, it is preferable to knead together with the aliphatic polyester resin by a biaxial extruder.

  In addition, the composition of the present invention contains, as desired, known additives used in the technical field, that is, a plasticizer, a heat stabilizer, an antioxidant, a crystallization accelerator, a flame retardant, a release agent, and the following. Organic fillers (rice husk, wood chips, okara, waste paper grinding material, clothing grinding material, cotton fiber, hemp fiber, bamboo fiber, wood fiber, kenaf fiber, hemp fiber, jute fiber, banana fiber, coconut fiber, etc. Plant fiber, and animal fibers such as silk, wool, Angola, cashmere, camel, paper powder, wood powder, bamboo powder, cellulose powder, rice husk powder, fruit shell powder, chitin powder, chitosan powder, protein, starch, etc.) Can be added.

  Moreover, the impact strength of the molded object obtained can be improved by adding the impact resistance improver used in the said field | area to the aliphatic polyester resin composition in this invention. For example, at least one selected from the following various impact resistance improvers can be used. That is, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, ethylene-butene-1 copolymer, various acrylic rubbers, ethylene-acrylic acid copolymer and alkali metal salts thereof (So-called ionomer), ethylene-glycidyl (meth) acrylate copolymer, ethylene-alkyl acrylate copolymer (for example, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer), acid-modified ethylene -Propylene copolymer, diene rubber (eg polybutadiene, polyisoprene, polychloroprene), copolymer of diene and vinyl monomer (eg styrene-butadiene random copolymer, styrene-butadiene block copolymer, styrene-butadiene) − Tylene block copolymer, styrene-isoprene random copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, polybutadiene grafted with styrene, butadiene-acrylonitrile copolymer) And polyisobutylene, a copolymer of isobutylene and butadiene or isoprene, natural rubber, thiocol rubber, polysulfide rubber, polyurethane rubber, polyether rubber, epichlorohydrin rubber, polyester elastomer, polyamide elastomer and the like. An elastomer modified with maleic acid or an amine-modified one can also be preferably used. Examples of these elastomers are hydrogenated styrene-based thermoplastic elastomers from Asahi Kasei Chemicals, Inc., trade names, “Tuftec M1911”, “Tuftec M1913”, “Tuftech M1943”, or terminal amine-modified elastomers also from Asahi Kasei Chemicals. Trade name, “TDM19”, manufactured by Mitsubishi Rayon Co., Ltd., trade name, “Metablene” series, manufactured by Sumitomo Chemical Co., Ltd., trade names, “Bond First E”, “Bond First 7M”, and the like.

The method for preparing the aliphatic polyester resin composition of the present invention is not particularly limited, and known aliphatic polyester kneading techniques, that is, aliphatic polyester, nonionic surfactant, talc and, if necessary, organically modified layered silica. It can be prepared by melt kneading the acid salt. Among them, a kneading method using a twin screw extruder that can enhance dispersibility by efficiently applying shear stress during kneading is preferably used. A dry blend method in which pellets are mixed in advance can be suitably used for all pellet-like materials.
The extrusion molding in the present invention is not particularly limited, and means any extrusion method generally used. As the die, a T die or a round die is preferably used. Although there is no restriction | limiting in particular also in extrusion temperature, It is preferable that it is more than melting | fusing point of aliphatic polyester. Specifically, about 170-230 degreeC is preferable. If the extrusion temperature is too high, the aliphatic polyester resin tends to decompose.

  Although there is no restriction | limiting in particular also in the thickness of a sheet | seat, 3 micrometers-3 mm are preferable, 50-1 mm is more preferable, 100-500 micrometers is further more preferable. Further, the obtained sheet can be stretched by simultaneous biaxial stretching, sequential biaxial stretching, etc., or can be made into a laminated structure using a co-extrusion facility having a feed block or a multi-manifold die. Is possible.

  Moreover, a foam sheet can also be created by adding a chemical foaming agent, a physical foaming agent, or both. As the foaming agent, those commonly used in the art can be used. For example, examples of the inorganic compound include hydrogen carbonates such as sodium hydrogen carbonate, ammonium carbonate, and the like. Examples of the organic compound include polycarboxylic acid, azo compound, sulfone hydrazide compound, nitroso compound, p-toluenesulfonyl semicarbazide, isocyanate compound and the like. Examples of the polycarboxylic acid include citric acid, oxalic acid, fumaric acid, and phthalic acid. Examples of the azo compound include azodicarbonamide (ADCA). Moreover, what combined several types of these is also mentioned. On the other hand, examples of the physical foaming agent include carbon dioxide gas, nitrogen gas, hydrocarbon, neon, helium, oxygen, water, and chlorofluorocarbon, but are not limited thereto.

There is no restriction | limiting in particular in the press molding in this invention, vacuum forming, pressure forming, and vacuum pressure forming, The general forming method used in the said field | area can be used. In addition, the container in the present invention is not limited at all, and means any one of cups, trays, pots, blister pack containers, container-shaped containers, bowl-shaped containers, and the like.
Here, in order to obtain an aliphatic polyester resin container having high heat resistance, the mold temperature is set to a temperature that is 20 ° C. higher than the glass transition point (Tg) of the aliphatic polyester and lower than the melting point by about 20 ° C. Is preferred. The optimal mold temperature varies slightly depending on the type of composition, composition ratio, sheet thickness, etc., but when the aliphatic polyester resin is polylactic acid, it is preferably 80 ° C to 140 ° C, more preferably 100 ° C to 130 ° C, More preferably, it is 110-120 degreeC.
Since the aliphatic polyester resin composition in the present invention has a remarkably high crystallization rate, production efficiency can be improved by significantly shortening the crystallization time in the mold, that is, the molding cycle time.

EXAMPLES Although this invention is demonstrated based on an Example, this invention is not limited only to a following example. Measurement methods and molding methods used for the evaluation of Examples and Comparative Examples are shown below.
Solid Tray Molding The resin raw materials were put into the same direction twin screw extruder and pelletized after melt kneading so that the resin compositions shown in Examples 1 to 6 and Comparative Examples 1 to 3 were obtained. The pellets were extruded from a T die at a resin temperature of 180 ° C. using a single screw extruder with a screw system of 30 mm, and an amorphous sheet having a thickness of about 500 μm was prepared with a 45 ° C. casting roll. The sheet was preheated at 110 to 120 ° C. for about 10 to 30 seconds, and then formed into a tray shape having a diameter of 200 mm and a depth of 20 mm using a vacuum forming machine. The mold temperature is 110 ° C. The molding test was conducted by changing the molding time from 5 seconds to 200 seconds by 40 points every 5 seconds. The sample with the shortest molding time among the molds that could be released was placed in an oven at 100 ° C. to 140 ° C. and left for 10 minutes.

In this molding process, the following three types of evaluation were performed.
Mold release time:
When vacuum molding was performed while changing the molding time, the shortest molding time when the tray was released without deformation was indicated.
Vacuum forming stability:
The trays obtained by vacuum molding have good surface smoothness and no cracks, wrinkles, etc. are recognized. ◎, no cracks are recognized, but some molding spots are observed. The case where “crack” was considerably recognized was indicated by Δ, and the case where the sheet was cracked and could not be formed during vacuum forming was indicated by ×.
Heat-resistant:
When the tray is placed in an oven at 100 ° C. to 140 ° C. for 10 minutes, the tray is not deformed at all, ◎ if the deformation of the tray is less than 1%, ○ if 1% -5%, Δ, 5% The larger one was rated as x.

[Example 1]
Polylactic acid (manufactured by Nature Works, trade name, NatureWorks 4032D), talc (HiFiller5000PJ, produced by Matsumura Sangyo Co., Ltd.), polyoxyethylene glyceryl isostearate (20E.O.) as a nonionic surfactant (trade name, manufactured by Japan Emulsion) , Emalex GWIS-120) was poured into a twin screw extruder with a screw diameter of 30 mm so as to have a composition ratio as shown in Table 1, and melt kneaded to obtain an aliphatic polyester resin composition pellet. The kneading temperature was 200 ° C. This pellet was used for the above-described solid tray molding. The evaluation results are shown in Table 1.

[Example 2]
Solid tray molding was carried out under the same conditions as in Example 1 except that the composition of Example 1 was further added as an organically modified layered silicate by Cope Chemical Co., Ltd. and trade name MEE at the composition ratio shown in Table 1. . The evaluation results are shown in Table 1.

[Example 3]
Solid tray molding was carried out under the same conditions as in Example 1 except that the nonionic surfactant was changed from Emalex GWIS120 to polyoxyethylene glycol distearate (trade name, Emalexdi-S, manufactured by Japan Emulsion). The evaluation results are shown in Table 1.

[Example 4]
As in Example 1, except that an epoxy-based compound (trade name: ARUFON-UG4040, manufactured by Toagosei Co., Ltd.) is added to the composition of Example 2 as a carboxyl group terminal blocker of aliphatic polyester at a composition ratio shown in Table 1. Solid tray molding was carried out under the following conditions. The evaluation results are shown in Table 1.

[Example 5]
Solid tray molding was performed under the same conditions as in Example 1 except that polybutylene adipate terephthalate (BASF, trade name: Ecoflex) was added as a flexible resin to the composition of Example 2 at the composition ratio shown in Table 1. Carried out. The evaluation results are shown in Table 1.

[Comparative Example 1]
Only a polylactic acid (manufactured by Nature Works, trade name, NatureWorks 4032D) was subjected to solid tray molding under the same conditions as in Example 1. The evaluation results are shown in Table 1.

[Comparative Example 2]
Polylactic acid (manufactured by Nature Works, trade name: NatureWorks 4032D) and talc (HiFiller5000PJ, manufactured by Matsumura Sangyo Co., Ltd.) were biaxially kneaded so as to have the composition ratio shown in Table 1. The composition was subjected to solid tray molding under the same conditions as in Example 1. The evaluation results are shown in Table 1.

[Comparative Example 3]
Polylactic acid (manufactured by Nature Works, trade name, NatureWorks 4032D), talc (HiFiller5000PJ, made by Matsumura Sangyo Co., Ltd.) and polybutylene adipate terephthalate (BASF, trade name: Ecoflex) have the composition ratio shown in Table 1. Biaxial kneading. The composition was subjected to solid tray molding under the same conditions as in Example 1. The evaluation results are shown in Table 1.

  From the comparison between Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that when the aliphatic polyester resin composition sheet in the present invention is vacuum-formed, the releasability is very good (release time is short). This is based on the fact that the composition of the present invention has a very high crystallization rate and the rigidity is improved in a short time. Moreover, it turns out that the heat resistance of the obtained tray is also very excellent. Among them, the effect is large when the organic layered silicate is contained. Specifically, the mold is released in a cycle time of about 5 seconds and has a heat resistance of 140 ° C. On the other hand, it can be seen that in the comparative example, even when 10% by weight of talc which is a general crystal nucleating agent is added, the releasability is very poor.

On the other hand, with respect to vacuum molding stability, it can be seen that excellent molding results are obtained when fatty acid polyoxyethylene glyceryl is used among nonionic surfactants. Furthermore, remarkably good results have been obtained by adding a carboxy end-blocking agent or a flexible resin. In addition, these compositions have good release properties and heat resistance. That is, the addition of a carboxy terminal blocking agent and a flexible resin in this system does not inhibit the high crystallization rate that is a feature of the present invention.
In conclusion, it can be seen that the sheet obtained from the aliphatic polyester resin composition of the present invention is a very balanced sheet that can achieve both moldability in vacuum molding and heat resistance of the molded article obtained.

  Since the aliphatic polyester resin extruded sheet of the present invention is excellent in both moldability and heat resistance, it is possible to produce molded containers for various uses such as food containers, beverage containers, chemical containers, cosmetic containers and the like. .

Claims (9)

  Aliphatic polyester resin composition comprising a mixed composition comprising aliphatic polyester 60.0-99.9% by weight, talc 0.05-20% by weight, and nonionic surfactant 0.05-20% by weight Extruded sheet consisting of   From an aliphatic polyester resin composition to which 0.01 to 10 parts by weight of an organically modified layered silicate obtained by treating a layered silicate with an organic onium salt is further added to 100 parts by weight of the mixed composition The extruded sheet according to claim 1.   3. The aliphatic polyester resin composition further comprising 0.01 to 30 parts by weight of a flexible resin having a glass transition point (Tg) of 0 ° C. or less with respect to 100 parts by weight of the mixed composition. Extrusion sheet as described.   The nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ether, difatty acid polyoxyethylene glycol, mono fatty acid polyoxyethylene sorbitan, and fatty acid polyoxyethylene glyceryl, polyglycerin fatty acid ester, glycerin fatty acid ester. The extruded sheet according to any one of claims 1 to 3, which is at least one compound.   The extrusion molding according to any one of claims 1 to 3, wherein the nonionic surfactant is at least one compound selected from the group consisting of polyoxyethylene alkyl ether, fatty acid polyoxyethylene glyceryl, and polyglycerol fatty acid ester. Sheet.   The extruded sheet according to any one of claims 1 to 3, wherein the nonionic surfactant is a fatty acid polyoxyethylene glyceryl.   The extruded sheet according to any one of claims 1 to 6, wherein the aliphatic polyester is polylactic acid.   The extrusion molded sheet according to any one of claims 1 to 7, wherein the aliphatic polyester resin composition contains a carboxyl group terminal blocker of an aliphatic polyester.   A container obtained by molding the extruded sheet according to any one of claims 1 to 8 by any one of press molding, vacuum molding, pressure molding, and vacuum / pressure molding.