JP2002226691A - Polyglyolic acid type resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition and its molded product, the main ingredient of which is a polyglycolic acid type aliphatic polyester resin, and the composition having an excellent biodegradable property which has not been known before, together with softness, processability, practical strengths, and barrier property when the composition is subjected to process for making thin-wall product. SOLUTION: The glycolic acid type resin composition and its molded product, in which the resin composition (C) contains 0.5 to 30% by weight of an additive (B) to the resin (A) of which the main ingredient is the polyglycolic acid type aliphatic polyester resin, having the crystal melting point of 110 to 250 deg.C, the resin composition is characterized by using a glycerin triester of fatty acid as the main ingredient of the additive (B), wherein the fatty acids, which constitute three ester groups, has the total number of carbon atoms of 9 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable resin composition and a molded product comprising the composition. The application is not particularly limited, but in detail, packaging materials, medical materials, and other daily necessities with excellent biodegradability and flexibility, processing stability, practical strength, and barrier properties when thinned, heat resistance.・ It relates to industrial goods.

[0002]

2. Description of the Related Art In recent years, an increase in the amount of plastic discarded from homes and factories has become a major social problem. Conventionally, many polymer materials have been manufactured for the purpose of being stable over a long period of time, and therefore they are not easily decomposed in a natural environment, and require manual treatment. At present, waste disposal is incineration or burial disposal, but the amount of waste plastic waste far exceeds the capacity of the disposal side, causing problems in how to dispose of it. In addition, plastic discarded due to some users' disregard for the rules by disregarding the rules impairs the natural scenery and causes problems such as polluting the living environment of marine life.

[0003] Under such circumstances, biodegradable polymers that disintegrate due to hydrolysis, microbial degradation, etc. have attracted attention as polymer materials that do not burden the environment, and many researches and developments have been conducted. It is known that a material such as polyethylene, polypropylene, or polystyrene is blended with starch to impart biodegradability. In this method, the resin molded product itself disintegrates due to biodegradation of the starch, but other components remain as they are, and environmental pollution is promoted, so it is hard to say that it is a true biodegradable polymer. .

[0004] As a polymer material which easily undergoes biodegradation, there is firstly a starch alone or a material containing vegetable fiber, protein, fat, calcium, etc., which is used as a buffer material or a disposable tableware. However, these are extremely weak to moisture and have various restrictions for practical use. Cellulose-based materials are somewhat more water-resistant than those described above, but processing is difficult because of the lack of thermoplasticity of cellulose and productivity is low, thus raising processing costs. Materials made of microorganism-producing polyesters such as polyhydroxybutyric acid (PHB) and polyhydroxyvaleric acid (PHV) have to depend on the production capacity of microorganisms, and have problems in cost reduction and purity due to mass production. .

[0005] Materials produced from the above-mentioned raw materials derived from natural products are polymerized by chemical synthesis (polymerization step), and research on the materials produced has been actively conducted. Among them, polycaprolactone (hereinafter abbreviated as PCL), polybutylene succinate (PBS) and its adipate (PBSA) or carbonate copolymer, polyethylene succinate (PES), polyvinyl alcohol (PVA), polyurethane (PU ), Polylactic acid (PL
A), polyglycolic acid (PGA) and the like.

[0006] PCL is a typical soft polymer, and has a low crystal melting point and thus has excellent moldability but cannot be used as a heat-resistant material. The same is applied to PBS and a carbonate copolymer of PBSA or PBS, PES,
Although PES exhibits relatively good barrier properties, it cannot be used for materials that also require heat resistance. Although PVA is biodegradable, bacteria that promote it are scarce in the general environment, and usually remain in the environment with little biodegradation. PLA has moderate heat resistance, but does not have barrier properties such as oxygen permeability and water vapor permeability. Further, it is not easy to use as a material requiring a high glass transition point, being rigid and brittle, and thus having a pliability, and its utility value is limited. PGA is a material exhibiting high heat resistance and very excellent barrier properties, but is hard, rigid and poor in flexibility, and has low processing stability due to its heat resistance.

As described above, flexibility, processing stability, ability to exhibit heat resistance, practical strength,
Also, a biodegradable resin material having a barrier property when thinned and plasticized has not been obtained yet. In view of the above, among the above, various methods have been devised to improve the usability like a polyolefin by imparting flexibility by plasticizing a rigid resin because it is brittle, and exhibiting an appropriate elongation and an appropriate elastic modulus. Among them, the PLA-based resin composition has a problem that the heat resistance and the barrier property are further greatly reduced when it is plasticized (for example, Japanese Patent Application Laid-Open No. Hei 4-335060, Japanese Translation of PCT International Publication No. 2000-350).
Publication No. 506204).

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to use a polyglycolic acid-based aliphatic polyester resin as a main component and to exhibit excellent biodegradability, flexibility, processing stability and heat resistance (amorphous・ Low crystallinity is possible), practical strength,
Another object of the present invention is to provide an unconventional special resin composition having a barrier property when thinned and plasticized, and a molded product thereof, preferably a sheet or film.

[0009]

That is, the present invention provides:
(1) A resin composition (C) containing 0.5 to 30% by weight of an additive (B) with respect to a resin (A) mainly composed of a polyglycolic acid-based aliphatic polyester resin having a crystal melting point of 110 to 250 ° C. Wherein the main component of the additive (B) is a glycerol triester in which the total number of carbon atoms of fatty acids constituting three ester groups is 9 or less, a polyglycolic acid-based resin composition, (2) The polyglycolic acid-based resin composition according to (1), wherein the polyglycolic acid-based aliphatic polyester resin contains 3 to 45 mol% of a component other than glycolic acid that is copolymerized.
(3) polyglycolic acid-based aliphatic polyester resin,
Having a unit derived from glycolic acid; and other copolymer components such as a lactic acid derivative, 2-hydroxy-2,2-dialkylacetic acid, 3-hydroxy-2,2-dialkylpropionic acid, 3-hydroxybutyric acid, and 4-hydroxybutyric acid. Hydroxybutyric acid, 3
-Hydroxyvaleric acid, 3-hydroxycaproic acid, ε-
The polyglycolic acid-based resin composition according to (1) or (2), which comprises at least one unit selected from caprolactone, and (4) a resin mainly composed of a polyglycolic acid-based aliphatic polyester resin. (A) is a mixed resin containing at least one resin selected from aliphatic polyester resins (D) other than polyglycolic acid aliphatic polyester resins and other thermoplastic resins (E) in an amount of 1 to 45% by weight. % (1)-
The polyglycolic acid-based resin composition according to any one of (3) and (5) the resin composition (C) having an oxygen permeability of 100
(Cc / m ² · day · atm · 200 μm) or less, the polyglycolic acid-based resin composition according to any one of (1) to (4), (6) above (1) to (4).
(5) A molded product, wherein the polyglycolic acid-based resin composition according to any of (5) is processed into a film or sheet, (7) the film or sheet has a 2% tensile modulus of 0. The molded product according to (6), wherein the molded product has a weight of 1 to 200 kg / mm ² .

In the present invention, the crystal melting point is 110 to 25.
The polyglycolic acid-based aliphatic polyester resin at 0 ° C.
Glycolic acid, a direct polymer of glycolic acid oligomer, a glycolic acid ester polycondensate, a glycolide ring-opening polymer, and the like, preferably glycolic acid, glycolic acid oligomer, glycolic acid ester, glycolide, etc. Copolymers with the above monomers, and those having optical isomers in the copolymer component are the D-form, L-form, DL (racemic)
Body, meso body, etc. are included. Here, the copolymer includes a random shape, a block shape, and a free mixed structure of both.

Among other monomers to be copolymerized, aliphatic hydroxycarboxylic acids include, for example, lactic acid derivatives,
-Hydroxy-2-monoalkylacetic acid, 2-hydroxy-2,2-dialkylacetic acid, 3-hydroxy-2,2-
Dialkylpropionic acid, 3-hydroxy-3-monoalkylpropionic acid, 4-hydroxybutyric acid, 4-hydroxy-4-monoalkylbutyric acid, 5-hydroxyvaleric acid,
3-hydroxy-2-monoalkylpropionic acid, 4-
Hydroxy-2-monoalkylbutyric acid, 4-hydroxy-
3-monoalkylbutyric acid, 3-hydroxy-3,3-dialkylpropionic acid, 6-hydroxycaproic acid, 3-
Hydroxy-2-monoalkylvaleric acid, 4-hydroxy-2-monoalkylvaleric acid, 5-hydroxy-2-monoalkylvaleric acid, 5-hydroxy-5-monoalkylvaleric acid, 2-hydroxy-3,3- Dialkylpropionic acid, 4-hydroxy-3,4-dialkylbutyric acid, 5-hydroxy-3-monoalkylvaleric acid, 4-hydroxy-
4,4-dialkylbutyric acid, 5-hydroxy-4-monoalkylvaleric acid, 3-hydroxy-2,2,3-trialkylpropionic acid, 4-hydroxy-2,2-dialkylbutyric acid, 4-hydroxy-3, 3-dialkylbutyric acid, 3
And at least one selected from -hydroxy-2,3,3-trialkylpropionic acid, 4-hydroxy-2,3-dialkylbutyric acid, and other known compounds.

However, when these cyclic dimers and optical isomers (D-form, L-form, DL-form, meso-form) are present,
Include them. Further, these esters may be used as raw materials and copolymerized. Examples of lactones to be copolymerized include β-propiolactone, γ-butyrolactone, β-butyrolactone, δ-valerolactone, γ-valerolactone, δ-caprolactone, ε-caprolactone, and the like.

Among other monomers copolymerized in the same manner, aliphatic polyhydric alcohols include ethylene glycol, diethylene glycol, other polyethylene glycols, propylene glycol, dipropylene glycol,
Other polypropylene glycols, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6 -Hexanediol, 2,2-trimethyl-1,6-hexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol And diols having a carbonate bond, and those containing ethylene oxide, propylene oxide and the like can also be used. These may be combined into multiple components.

Among the other monomers to be copolymerized, aliphatic polycarboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, 2,2-dimethylglutaric acid, suberic acid. , Azelaic acid, sebacic acid,
1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4
-It is possible to use cyclohexanedicarboxylic acid, diglycolic acid, phthalic acid, isophthalic acid, terephthalic acid and their ester derivatives, acid anhydrides and the like.
These may be combined into multiple components.

Further, although not limited thereto, examples of preferable combinations include, for example, those obtained by copolymerizing glycolic acid as a main raw material with a small amount of L-lactic acid or D-lactic acid, or the same DL product And copolymerized with 2-
Hydroxy-2,2-dialkylacetic acid, 3-hydroxy-2,2-dialkylpropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-
Examples thereof include those copolymerized with hydroxycaproic acid and ε-caprolactone (including the above-mentioned random, block, and others). Further, polycondensation may be performed using these esters as raw materials.

The ratio of these other monomers to be copolymerized varies somewhat depending on the target component, but is preferably 1 to 50 mol%, more preferably 2 to 50 mol%, expressed as the total of the other monomers to be copolymerized. It is about 45 mol%, more preferably about 3 to 45 mol%, and most preferably about 3 to 30 mol%. The preferable ratio of the total of these other monomers to be copolymerized is limited at the lower limit by deterioration of compatibility with the additive (B), and at the upper limit by maintaining barrier properties and heat resistance. In addition, the resin (A) mainly composed of a polyglycolic acid-based aliphatic polyester resin is other than the aliphatic polyester-based resin (D) other than the polyglycolic acid-based aliphatic polyester resin and other thermoplastic resins (E). At least one kind of resin may be used as a mixture.

The ratio of these resins when mixed is slightly different depending on the target component, but is generally 1 to 45% by weight, preferably 2 to 40% by weight, expressed as the total of the mixed resins (D) to (E). %, More preferably about 3 to 30% by weight. Specifically, as the resin (D), lactic acid, 2
-Hydroxy-2,2-dialkylacetic acid, 3-hydroxy-2,2-dialkylpropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid,
A polymer containing at least 50 mol% or more of at least one monomer unit (or an ester unit thereof) selected from -hydroxycaproic acid, ε-caprolactone, and the like;
And copolymers thereof, optical isomers thereof, copolymers containing glycolic acid in an amount of less than 50 mol%, and resins comprising the above-mentioned copolymer components. To be converted as another monomer). The composition also includes a composition such as a stereocomplex of a copolymer with a poly-L or poly-D form.

Next, other thermoplastic resins (E) include polyolefin resins, ordinary polyester resins containing aromatic monomers, polyamide resins, and ethylene-based resins.
Vinyl alcohol copolymer resin, α-olefin (ethylene, other) -styrene copolymer resin (or the same hydrogenated resin), α-olefin-carbon monoxide copolymer resin (the same hydrogenated resin), Ethylene-alicyclic hydrocarbon copolymer resin (including the hydrogenated resin), styrene-butadiene to isoprene copolymer resin (including the hydrogenated resin), petroleum resin (including the hydrogenated resin), natural resin ( A resin obtained by polymerizing a raw material as a natural product (including the hydrogenated resin);
And others.

The degree of polymerization of the polyglycolic acid-based aliphatic polyester resin of the present invention is in the range of weight average molecular weight (Mw).
(However, the measurement is carried out by gel permeation chromatography in accordance with ASTM-D3536, and the molecular weight is calculated in terms of standard polymethyl methacrylate), which is usually about 20,000 to 1,000,000, preferably 50,000. 000-800,000, more preferably 7
It is between 000 and 700,000. These lower limits are limited by strength, proper melt viscosity during processing (processing stability), heat resistance, and the like, and upper limits are limited by compatibility with additives and workability.

The resin (A) in the present invention contains a polyglycolic acid-based aliphatic polyester resin having a crystal melting point (measured according to a DSC method described later) of 110 to 250 ° C. as a main component. When the crystal melting point of the resin (A) is less than 110 ° C., the heat resistance is insufficient in applications requiring heat resistance, and when it exceeds 250 ° C., the decomposition temperature becomes close, and the extrusion moldability due to a decrease in molecular weight and the like is reduced. It is not preferable because it causes instability and coloration. More preferred these ranges are from 120 to 230 ° C. for the same reason, and even more preferably 1 to 230 ° C.
40-220 ° C.

The crystal structure of the polyglycolic acid-based aliphatic polyester resin can be freely controlled to some extent by a catalyst or the like, but within the ranges described above and below, various structures and block-like crystal structures are also included. . Furthermore, the range of the crystallinity of the polyglycolic acid-based aliphatic polyester resin (measured according to a DSC method described later) is usually 3 to
It is about 50%, preferably 4 to 40%. These lower limits are limited by heat resistance, and the upper limits are limited by familiarity with additives. However, as for the composition and the resin itself, even if the degree of crystallinity is reduced due to the influence of processing conditions and additives, it can be used as it is. The degree of crystallinity may exceed the range specified here, since the crystallinity may appear.

The additive (B) used in the present invention is useful for plasticizing the resin (A) and is necessary for improving processability. It is also convenient for facilitating post-disposal composting. The main component is 3
It is a glycerin triester in which the total number of carbon atoms of fatty acids constituting two ester groups is 9 or less. It has been found that the resin (A) used in the present invention is plasticized by the above-mentioned specific glycerin ester, but if the number of ester groups of the component used as the additive (B) is small, the resin (A) ) Is hydrolyzed and the molecular weight tends to decrease, so that the ester group is preferably saturated. Further, when the total number of carbon atoms of the fatty acid constituting the ester group is large, the compatibility with the resin (A) is deteriorated and plasticization is difficult to proceed. It is preferable that the total number of carbon atoms of the fatty acids constituting the above is small.

Specifically, these are at least one selected from triacetin, glycerin diacetate monopropionate, glycerin dipropionate monoacetate, tripropionin and the like. The amount added
0.5 to 30% by weight based on the resin (A),
A preferred range is 3 to 27% by weight, more preferably 5 to 25% by weight. These lower limits are limited by the lack of flexibility of the resin composition (C), and the upper limits are limited by dimensional stability, heat resistance, insufficient molding processing stability, and insufficient strength. In addition to the above-mentioned glycerin triester as a main component, the additive (B) may be other known glycerin esters, polyglycerin esters, other monovalent alcohols, or aliphatic fatty acid esters with polyhydric alcohols (F).
At least one of them may be used in a small mixture.

Specifically, these include, for example, polyglycerol esters such as glycerin ester or diglycerin ester, and caproic acid, caprylic acid, capric acid,
Di- and tri-double bonds such as saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid, and normal monounsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid A free ester having at least one kind of a fatty acid (however, it is needless to say that an ester containing one part of acetic acid or propionic acid may be used), or a free ester of sorbitan and the above-mentioned fatty acid as described above Or a free ester of ethylene glycol, propylene glycol, tetramethylene glycol, or a polycondensate thereof and the above-mentioned fatty acid, or an aliphatic hydroxycarboxylic acid such as citric acid, malic acid, or tartaric acid; Malonic acid, succinic acid, glu Free esters such as luic acid, adipic acid, terephthalic acid, and isophthalic acid, or polycondensates thereof, or epoxidized modified soybean oil, epoxidized modified linseed oil, and the like. It can be mixed and used within a range of less than 50% by weight, preferably 0.1 to 40% by weight, more preferably 0.2 to 30% by weight.

In the case where a small amount of a high-viscosity component bleeds to the surface simultaneously with the plasticization, the plasticization and the adhesion are satisfied at the same time, and it may be more preferable depending on the application. The resin composition (C) of the present invention includes, for example, injection molding, extrusion molding, blow molding, calendar molding, vacuum molding, foam molding,
Processed into injection molded products, foams, extruded sheets, inflation, cast films, stretched films, etc. by manufacturing methods such as compression molding, etc., for example, packaging materials, bio-medical applications (sustained release materials, culture materials, etc.) ). The range of the tensile modulus (processed into a sheet and measured by the method described later) of the resin composition (C) of the present invention is generally 0.1 to 200 kg / mm.
² The preferred range for this value is 0.2-170 kg
/ Mm ² , more preferably 0.3 to 150 kg / m
m ² , more preferably 0.4 to 120 kg / mm ² .

The tensile modulus (kg / mm ² ) is measured using a quenched press sheet having a thickness of 200 μm as a sample and at room temperature of 23 ° C. and humidity of 50% in accordance with ASTM-D882. 10% stress at 2% elongation
It is the average value (sample number = 5) of values converted to 0% and further converted to thickness. The values here are also applied to the case where the above-mentioned quenched press sheet is heat-treated and a sample whose free crystallinity is controlled is obtained. Further, the present invention is also applicable to a case where a sample that has been stretched and processed into a film shape and subjected to free heat treatment is used as a sample.

The resin composition (C) of the present invention has a flow index (M
FR) is measured as 210 ° C. under a load of 2160 g according to ASTM-D1238. The value obtained is the mass of the sample extruded in 10 minutes (number of samples =
3 (average of 3), and the unit is (g / 10 min). MF
A preferred range of R is 40 or less, more preferably 30 or less, and a still more preferred range is 20 or less. The crystalline melting point of the resin composition of the present invention is determined by a DSC method (peak value under a scan speed of 10 ° C./min) according to ASTM-D1238.

Further, the crystallinity of the raw material resin of the present invention can be simply determined by comparing the melting energy of 100% crystal with the crystal melting energy of PGA of 206.5 J / g (source: JAP Sc).
iVol. 26.1727 to 1734: 1981) and determine the correlation with the melting energy of the raw resin obtained by the DSC method (similar to the crystal melting point measurement method). The oxygen permeability of the resin composition of the present invention is 4% by calcium chloride in a desiccator in a room controlled at 23 ° C.
The sample which has been dried for 8 hours is measured and determined in a room controlled at 23 ° C. by a method according to JIS-K-7126. The value obtained is 1m in 24 hours
The volume of oxygen permeated through the sheet under a pressure difference of 1 atm per ² (average value of the number of samples = 3), and the unit is (cc)
/ M ² · day · atm · 200 μm). The preferred range of the oxygen permeability is 100 or less, more preferably 70 or less.
Hereinafter, a more preferable range is 50 or less.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The details of the resin (A) mainly containing a polyglycolic acid-based aliphatic polyester resin or the aliphatic polyester resin (D) other than the polyglycolic acid-based aliphatic polyester resin used here are as follows. A-
1 is a polyglycolic acid-based aliphatic polyester resin,
20 mol% of L-lactide in 80 mol% of glycolide
Copolymerized resin (crystal melting point 190 ° C, crystallinity 25%,
(Mw = 300,000).

A-2 is a polyglycolic acid-based aliphatic polyester resin obtained by copolymerizing 95 mol% of glycolide with 5 mol% of L-lactide (crystal melting point: 200 ° C., crystallinity: 35%, Mw = 200). , 000). A-3
Is a polyglycolic acid-based aliphatic polyester resin obtained by copolymerizing 75 mol% of glycolide and 25 mol% of L-lactide (crystal melting point: 164 ° C., crystallinity: 10%, M
w = 330,000). A-4 is a polyglycolic acid-based aliphatic polyester resin obtained by copolymerizing 80 mol% of glycolide with 20 mol% of 2-hydroxyisobutyric acid (crystal melting point: 185 ° C., crystallinity: 20%, Mw = 30).
0000). A-5 is a polyglycolic acid-based aliphatic polyester resin having 90 mol% glycolic acid and L
-Resin obtained by copolymerizing lactic acid at 10 mol% (crystal melting point: 181)
° C, crystallinity 35%, Mw = 200,000).

D-1 is an aliphatic polyester resin other than the polyglycolic acid-based aliphatic polyester resin, and is PLA (crystal melting point 170 ° C., Mw = 300,000) obtained by ring-opening polymerization of L-lactide. . D-2 is
An aliphatic polyester resin other than the polyglycolic acid-based aliphatic polyester resin, L-lactide 37.5 mol%, DL-lactide 37.5 mol%, glycolide 2
Resin copolymerized with 5 mol% (no crystal melting point, Mw = 10
0000).

B-1 is triacetin. B-2
Is tripropionin. B-3 is glycerin diacetate monopropionate. B-4 is glycerin dipropionate monoacetate.

F-1 is tributyl acetylcitrate. F-2 is diacetin. F-3 is a glycerin monocap plate. F-4 is glycerin diacetate monolaurate. F-5 is glycerin diacetate monocaprylate.

(Examples 1 to 5) A-1 was used as resin (A).
And B-1, B-2, and B-3 as additives (B) were kneaded in a kneader at a rate shown in Table 1 at 210 ° C. for 15 minutes.
A 200 μm quenched sheet was prepared by a press, and the physical properties of the sheet were measured. The results are shown in Table 1 (units of numerical values are omitted). In Examples 1 to 5, B- was added to the additive (B).
When 1, B-2 and B-3 were used, the MFR was small, and it was found that the composition was less likely to cause a decrease in molecular weight. It was also confirmed that the degree of plasticization can be freely adjusted by the amount of addition. In Example 3, although the amount of the additive was 15% by weight, the oxygen permeability was 3 (cc / m ² · d).
ay.atm.200 μm), which confirms that the resin composition of the present invention has excellent barrier properties.
Further, when the sheet of Example 3 was heat-treated at 100 ° C. for 2 minutes and the physical properties were measured, the tensile elastic modulus was 70 (kg / m 2).
m ² ) and oxygen permeability of 2 (cc / m ² · day · atm)
200 μm).

[0035]

[Table 1]

(Comparative Examples 1 to 3) D-1 and D-
2 as additives B-1 and F-1 as Comparative Examples 1 to 3 in Table 2
In a combination as shown in No. 3, the mixture was kneaded with a kneader at 190 ° C. for 15 minutes, a 200 μm quenched sheet was prepared by a press, and the physical properties of the sheet were measured. The result (MFR
Table 2 shows the MFR measured at a set temperature of 190 ° C. and a load of 2160 g because the MFR was abnormally large at a set temperature of 210 ° C. and a load of 2160 g, and the measurement accuracy was not high. Omitted). The effects of suppressing the decrease in molecular weight and maintaining the barrier properties confirmed in Examples 1 to 5 were not observed. Further, even if the film was crystallized by heat treatment, the barrier property was not so improved.

[0037]

[Table 2]

(Comparative Examples 4 to 8) At a ratio shown in Table 3, A-1 as a resin (A) and an additive (F) were kneaded with a kneader, and physical properties of the kneaded material were measured. The results are shown in Table 3 (numerical units are omitted). In the case of a plasticizer in which a hydroxyl group remains in the molecule, such as F-2 and F-3, plasticization proceeds, but hydrolysis (molecular collapse) of the polymer proceeds, and MFR is remarkably increased to deteriorate processing stability. Was. Further, it was also found that when the alkyl chain in the ester group becomes longer as in F-4, plasticization does not proceed in the composition of the present invention.
Furthermore, F-5 was liable to have a large MFR.

[0039]

[Table 3]

(Examples 6 to 9) At the ratios shown in Table 4, A-2, A-3, A-4 and A-5 were used as the resin (A), and B-1 and B were used as the additives (B). -2, B-3, and B-4 were kneaded by a kneader at 210 ° C. for 15 minutes in a combination as shown in Examples 6 to 9, and a 200 μm quenched sheet was prepared by pressing, and the physical properties of the sheet were obtained. Was measured. The results are shown in Table 4 (numerical units are omitted). Examples 6 to 9
As in Examples 1 to 5, it was confirmed that the resin composition of the present invention hardly caused a decrease in molecular weight and had excellent barrier properties.

[0041]

[Table 4]

[0042]

According to the present invention, packaging materials, medical materials, and other materials having excellent biodegradability as well as heat resistance, flexibility and processing stability, practical strength, and barrier properties when thinned. A composition that can be used as an article or an industrial article could be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F071 AA43 AC10 AF08Y AF20Y AH04 BB06 BB07 BC01 4J002 BA013 BB013 BC043 BC053 BE033 CD164 CF032 CF043 CF181 CF191 CJ003 CL003 EH046 EH096 4J029 AA02 AB01 BA03 EA03 CA03 CA04 CA05 CA06 CD03 EA03 EA05 EG02 EG05 EG07 EG09

Claims (7)

[Claims] 1. A resin composition containing an additive (B) in an amount of 0.5 to 30% by weight based on a resin (A) mainly composed of a polyglycolic acid-based aliphatic polyester resin having a crystal melting point of 110 to 250 ° C. C) wherein the main component of the additive (B) is 3
A polyglycolic acid-based resin composition, which is a glycerin triester in which the total number of carbon atoms of fatty acids constituting two ester groups is 9 or less. 2. The polyglycolic acid-based aliphatic polyester resin contains three to three components other than glycolic acid.
The polyglycolic acid-based resin composition according to claim 1, which contains 45 mol%. 3. A polyglycolic acid-based aliphatic polyester resin having units derived from glycolic acid, and a lactic acid derivative, 2-hydroxy-2,2 as a copolymer component.
At least one unit selected from the group consisting of -dialkylacetic acid, 3-hydroxy-2,2-dialkylpropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-hydroxycaproic acid and ε-caprolactone Claim 1 or Claim 2
The polyglycolic acid-based resin composition according to the above. 4. A resin (A) mainly composed of a polyglycolic acid-based aliphatic polyester resin, wherein the mixed resin is an aliphatic polyester-based resin (D) other than the polyglycolic acid-based aliphatic polyester resin, and other heat At least one resin selected from the group consisting of plastic resins (E) and 1-45
The polyglycolic acid-based resin composition according to any one of claims 1 to 3, which is contained by weight. 5. The resin composition (C) having an oxygen permeability of 10
^{0 (cc / m 2 · day} · atm · 200μm) polyglycolic acid-based resin composition according to any one of claims 1 to 4, characterized in that less. 6. A molded product, wherein the polyglycolic acid-based resin composition according to claim 1 is processed into a film or a sheet. 7. The molded product according to claim 6, wherein the 2% tensile modulus of the film or sheet is 0.1 to 200 kg / mm ² .