JP2008308561A - Biodegradable polyester resin composition, method for producing the same, and molded article using the same - Google Patents

Abstract

A biodegradable resin composition having improved flexibility and bleed-out resistance without impairing gas barrier properties.
A biodegradable polyester resin composition comprising a biodegradable polyester resin and a rosin alcohol alkylene oxide adduct. The rosin alcohol alkylene oxide adduct has a molecular weight of 1,000 or more and 5,000 or less, and the alkylene oxide is selected from at least one block selected from ethylene oxide, propylene oxide, and butylene oxide, or at least two. It is a random copolymer.
[Selection figure] None

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 have attracted attention from the viewpoint of environmental conservation. Among the biodegradable resins, polylactic acid is one of the most transparent and highly heat-resistant resins, and its cost is low because it can be mass-produced from plant-derived raw materials such as corn and sweet potato. For this reason, it can contribute to the reduction of the amount of petroleum raw materials used, so it is highly useful.

  A biodegradable resin composition containing polylactic acid is excellent in moldability and mechanical strength, but lacks flexibility in films, sheets, injection-molded products and the like. In recent years, various modifiers have been used to improve the performance. However, most of them are mainly made from petroleum resources, and there is a problem that it conflicts with the purpose of using plant-derived resins. In general, a resin composition containing such a modifier has a problem of deterioration in performance and quality due to occurrence of bleedout of the additive under high temperature and high humidity, particularly deterioration in gas barrier properties.

  In order to improve these problems, for example, Patent Document 1 proposes a method of adding an ester derivative of rosin made from plants to polylactic acid. However, these ester compounds are inferior in compatibility with polylactic acid, impair transparency characteristics, and cannot improve processability.

  Patent Document 2 describes a derivative of rosin acid as a plasticizer for non-chlorine resin. However, when used for the modification of polylactic acid, not only the expected modification effect cannot be obtained due to poor compatibility, but also the problem that the residual rosin acid causes a decrease in the molecular weight of polylactic acid during melt kneading, rosin Derivatives of acids have a problem that the reaction becomes non-uniform, so that stable performance is difficult to be obtained, and coloring problems with time. In other words, it has many practical problems and is not appropriate.

  Patent Document 3 discloses a method of adding a rosin alcohol derivative to polylactic acid. However, no method for improving durability under high temperature and high humidity has been proposed.

Patent Document 4 proposes a method for increasing flexibility by adding a compound composed of repeating alkylene oxide units such as polyethylene glycol to polylactic acid. However, alkylene oxide compounds having hydroxyl groups at both ends have high hydrophilicity, thereby deteriorating the gas barrier properties of polylactic acid, and also have low durability under high temperature and high humidity.
JP 2001-049098 A JP 2003-160736 A JP 2006-193739 A Japanese Patent Laid-Open No. 08-199052

  An object of the present invention is to solve the above-mentioned problems, and to provide a biodegradable polyester resin composition that is flexible and excellent in bleed-out resistance without impairing gas barrier properties. And

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have added a rosin alcohol alkylene oxide adduct having a molecular weight in a specific range to the biodegradable polyester resin, so that the gas barrier property is not impaired. The present inventors have found that a biodegradable polyester resin composition having flexibility and excellent bleed-out resistance can be provided. Further, it has been found that when a layered silicate is added for the purpose of further improving the gas barrier property, the rosin alcohol alkylene oxide adduct has an effect of improving the appearance by increasing the dispersibility of the layered silicate.

  That is, the gist of the present invention is as follows.

  (1) A biodegradable polyester resin composition comprising a biodegradable polyester resin and a rosin alcohol alkylene oxide adduct satisfying the following (A) and (B).

(A) Molecular weight of 1,000 or more and 5,000 or less.
(B) A random copolymer in which the alkylene oxide is a block selected from at least one of ethylene oxide, propylene oxide, and butylene oxide, or at least two.

  (2) 0.01-100 parts by mass of at least one terminal blocker selected from a carbodiimide compound, an epoxy compound, an isocyanate compound, and an oxazoline compound is contained per 100 parts by mass of the biodegradable polyester resin ( The biodegradable polyester resin composition of 1).

  (3) The biodegradable polyester resin composition according to (1) or (2), wherein the biodegradable polyester resin is polylactic acid.

  (4) The biodegradable polyester resin composition according to any one of (1) to (3), wherein 0.5 to 20 parts by mass of a layered silicate is contained with respect to 100 parts by mass of the biodegradable polyester resin. object.

  (5) The biodegradability according to (4), wherein the layered silicate is formed by ionic bonding of any of primary to quaternary ammonium ions, pyridinium ions, imidazolium ions, and phosphonium ions between the layers. Polyester resin composition.

  (6) The biodegradable polyester resin composition according to any one of (1) to (3), wherein the flexural modulus measured at 23 ° C. according to ASTM-D790 is 3.5 GPa or less.

  (7) The biodegradable polyester resin composition according to (4) or (5), wherein the flexural modulus measured at 23 ° C. according to ASTM-D790 is 4.0 GPa or less.

(8) The oxygen permeation coefficient at 20 ° C. and a relative humidity of 90% is 220 ml · mm / m ² / day / MPa or less. (1) (2) (3) (6) Degradable polyester resin composition.

(9) The biodegradable polyester according to any one of (4), (5), and (7), wherein an oxygen permeability coefficient at 20 ° C. and a relative humidity of 90% is 150 ml · mm / m ² / day / MPa or less. Resin composition.

  (10) Any one of (2) to (9), wherein the molecular weight retention represented by the following formula is 90% or more after the wet heat treatment at 40 ° C. and a relative humidity of 90% for 300 hours: Biodegradable polyester resin composition.

Molecular weight retention (%) = C / D × 100
Where C: weight average molecular weight after wet heat treatment test
D: Weight average molecular weight before wet heat treatment test

  (11) In producing the biodegradable polyester resin composition according to any one of (1), (2), (3), (6), (8) and (10) above, the rosin alcohol alkylene oxide adduct is added during melt kneading or A method for producing a biodegradable polyester resin composition, which is added during molding.

  (12) A method for producing the biodegradable polyester resin composition according to any one of (4), (5), (7), (9) and (10) above, which is biodegradable during melt-kneading or molding. It has a two-stage process of a first stage in which a polyester resin composition and a terminal blocking agent are reacted first, and then a second stage in which a rosin alcohol alkylene oxide adduct and a layered silicate are added. A method for producing a biodegradable polyester resin composition.

  (13) A molded article characterized by being formed of any one of the biodegradable polyester resin compositions (1) to (10).

  (14) The molded article according to (13), which is a container.

  According to the present invention, by adding a rosin alcohol alkylene oxide adduct having a molecular weight in a specific range to a biodegradable polyester resin, the biodegradation has excellent flexibility and bleed-out resistance without impairing gas barrier properties. A functional polyester resin composition can be provided. Moreover, it is possible to further improve the barrier property by adding a layered silicate, and it is possible to provide a flexible resin composition having a higher barrier property. In addition, since the resin composition of the present invention has biodegradability, it can be composted when discarded, and therefore, the amount of waste can be reduced and reused as a fertilizer. Furthermore, rosin alcohol can generally be produced from plant-derived raw materials and has good safety and hygiene. Therefore, when polylactic acid derived from plant is used as a biodegradable polyester resin, It contributes to the prevention of resource depletion and can be provided as an environmentally friendly material.

  Hereinafter, the present invention will be described in detail.

<Biodegradable polyester resin>
Examples of the biodegradable polyester resin in the present invention include aliphatic polyesters mainly composed of α- and / or β-hydroxycarboxylic acid units, and polyesters composed of an aliphatic dicarboxylic acid component and an aliphatic diol component.

  Examples of α- and / or β-hydroxycarboxylic acid units include D-lactic acid, L-lactic acid, or a mixture thereof, glycolic acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-hydroxycaproic acid, and the like. And mixtures and copolymers thereof. Of these, D-lactic acid and L-lactic acid are particularly preferable. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, or lower alkyl ester compounds and acid anhydrides as derivatives thereof. Of these, succinic acid, succinic anhydride, and adipic acid are preferable. Aliphatic diols include ethylene glycol, 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 biodegradable polyester resins that can be used in the present invention include poly (ethylene succinate), poly (butylene succinate), poly (butylene succinate-co-butylene adipate) and the like in addition to polylactic acid. Aliphatic polyesters composed of diols and dicarboxylic acids, such as polyglycolic acid, poly (3-hydroxybutyric acid), poly (3-hydroxyvaleric acid), poly (3-hydroxycaproic acid) and other polyhydroxycarboxylic acids, poly (Ε-caprolactone) and poly (ω-hydroxyalkanoate) represented by poly (δ-valerolactone), poly (butylene succinate-co-butylene terephthalate), poly (butylene adipate-co-butylene terephthalate), etc. Polyester resin containing aromatic components; Ruamido; and polysaccharides such as starch; polyester ethers; polyester carbonates. These components may be used alone or in combination of two or more, may be mixed, or may be copolymerized. Moreover, as polylactic acid, although the content ratio of L-lactic acid and D-lactic acid is not specifically limited, As what is marketed, (L-lactic acid / D-lactic acid) = 80 / 20-99.8 / 0. Those in the range of 2 (molar ratio) are common.

  As the biodegradable polyester resin, it is preferable to use a resin containing 50% by mass or more of a resin derived from a plant-derived raw material because the plant-derived degree is high and the effect of reducing the amount of petroleum resources used is increased. More preferably, it is 60 mass% or more of resin which consists of a plant-derived raw material, More preferably, it is 80 mass% or more. It is particularly preferable to use polylactic acid as a resin made from plant-derived materials because moldability and transparency are improved.

  The biodegradable polyester resin is produced by a known melt polymerization method or, if necessary, further using a solid phase polymerization method. Poly (3-hydroxybutyric acid) and poly (3-hydroxyvaleric acid) can be produced by microorganisms.

  The biodegradable polyester resin used in the present invention may be partially crosslinked. Moreover, it may be modified with an epoxy compound or the like.

  The molecular weight of the biodegradable polyester resin is not particularly limited, but the melt flow rate (MFR) at 190 ° C., 21.2 N (2.16 kgf) (according to JIS K7210), which is an index thereof, is 0.1 to 50 g / 10 min. If it is a range, the resin can be used preferably, More preferably, it is the range of 0.2-40 g / 10min.

<Rosin alcohol alkylene oxide adduct>
The rosin alcohol alkylene oxide adduct used in the present invention satisfies the following (A) and (B).

(A) Molecular weight of 1,000 or more and 5,000 or less.
(B) A random copolymer in which the alkylene oxide is a block selected from at least one of ethylene oxide, propylene oxide, and butylene oxide, or at least two.

  Since rosin alcohol is obtained by reducing rosin made from plants, it can contribute to reducing the amount of fossil materials used. Examples of the production method include a method of hydrogenating a resin acid methyl ester with a copper chromium catalyst in the presence of a heavy metal catalyst or at 300 ° C. under a high pressure, a method of directly hydrogenating a dissolved rosin with Raney nickel, and the like. . Similarly, a polymerized rosin can be obtained by reduction to the corresponding rosin alcohol. However, in the present invention, the method for producing rosin alcohol is not particularly limited.

  The composition of rosin alcohol includes tetrahydroabiethyl alcohol, dihydroabiethyl alcohol, dehydroabiethyl alcohol and the like. The acid value of rosin alcohol is generally 3 or less, but the use of 0.5 or less is preferable from the viewpoint of maintaining the molecular weight.

  The molecular weight of the rosin alcohol alkylene oxide adduct needs to be 1,000 or more and 5,000 or less in order to improve the bleed-out resistance and not impair the gas barrier property while imparting flexibility. is there. The range is preferably 1,000 or more and 4,000 or less, more preferably 1,500 or more and 3,000 or less. In rosin alcohol alkylene oxide adducts, the abietinol moiety plays a role in increasing hydrophobicity, and the smaller the molecular weight of the rosin alcohol alkylene oxide adduct, the greater the proportion of the abietinol moiety in the whole and the higher the hydrophobicity, resulting in moisture resistance. Becomes larger. Further, the alkylene oxide moiety has high affinity with the biodegradable polyester resin, and can be imparted with flexibility while maintaining transparency by being compatibilized. Here, the longer the alkylene oxide moiety, the more flexible the biodegradable polyester resin. However, when the molecular weight exceeds 5,000, the alkylene oxide moiety becomes excessively long and the proportion of the abiethinol moiety occupies the whole, so that the moisture resistance effect is lowered. On the other hand, if the molecular weight is less than 1,000, the polyalkylene oxide moiety is shortened, the affinity with the biodegradable polyester resin is lowered and cannot be compatibilized, so that flexibility cannot be imparted. The objective cannot be achieved. The molecular weight of the rosin alcohol alkylene oxide adduct can be determined from the hydroxyl value measured according to the acetylation method described in JIS-K0070.

  The rosin alcohol alkylene oxide adduct used in the present invention is a block in which alkylene oxide is selected from at least one of ethylene oxide, propylene oxide and butylene oxide, or a random copolymer selected from at least two. When the proportion of ethylene oxide in the added alkylene oxide is high, the water resistance is lowered, but the solubility with polylactic acid is improved. When the ratio of butylene oxide is high, the hydrophobicity increases and the compatibility with polylactic acid decreases. Therefore, according to the performance required in each application, the type and ratio of the alkylene oxide to be added, its addition form (block addition or random addition), and the addition order can be adjusted.

  The rosin alcohol alkylene oxide adduct can be produced by a known method. For example, it can be obtained by adding alkylene oxide to rosin alcohol at 60 ° C. to 250 ° C. under pressure using an alkali catalyst as necessary.

  The blending ratio of the rosin alcohol alkylene oxide adduct is, by mass ratio, preferably biodegradable polyester resin / rosin alcohol alkylene oxide adduct = 70/30 to 98/2, more preferably 80/20 to 97 /. 3, most preferably 85/15 to 95/5. If the blending ratio is less than 2%, it is difficult to obtain the effect of improving the flexibility intended by the present invention. If it exceeds 30%, the gas barrier property of the biodegradable polyester resin is impaired, or the bleed-out after wet heat treatment Tend to be noticeable.

<End blocker>
The biodegradable polyester resin composition of the present invention comprises a carbodiimide compound, an epoxy compound, an isocyanate compound, and an oxazoline compound for the purpose of blocking the terminal group of the biodegradable polyester resin and improving the hydrolysis resistance. It may contain at least one compound selected from the group. Of these, carbodiimide compounds are most preferred. The total amount added is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the biodegradable polyester resin.

  Specific examples of the carbodiimide compound include N, N′-di-2,6-diisopropylphenyl carbodiimide (manufactured by Rheinhemy, product name: Stabuxol I), N, N′-di-o-tolylcarbodiimide, N, N Monocarbodiimides such as' -diphenylcarbodiimide, N-tolyl-N'-cyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, and aliphatic polycarbodiimides (for example, Nisshinbo Co., Ltd., product name: Carbodilite LA-1), aromatic Group polycarbodiimide (for example, manufactured by Rheinhemy, product name: Starvacol P, etc.). These carbodiimide compounds may be used alone or in combination of two or more. Of these, N, N′-di-2,6-diisopropylphenylcarbodiimide is particularly preferable.

  Specific examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutadiene diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol. Diglycidyl ether, cyclohexane dimethanol diglycidyl ether, hydroquinone diglycidyl ether, N-glycidyl phthalimide, hydrogenated bisphenol A-diglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl Ether, trimethylpropanepolyg Sidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenyl (polyethylene glycol) glycidyl ether, phenyl (polypropylene glycol) glycidyl ether, p-tert-butylphenyl glycidyl ether, diglycidyl-o-phthalate, diglycidyl terephthalate, dibromophenyl Examples thereof include glycidyl ether, epoxidized vegetable oil, and a polymer having a glycidyl group in the side chain. These epoxy compounds may be used independently and may be used in combination of 2 or more type. Of these, ethylene glycol diglycidyl ether or polyethylene glycol diglycidyl ether is particularly preferable.

  Specific examples of the isocyanate compound include hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. These isocyanate compounds may be used alone or in combination of two or more. Of these, hexamethylene diisocyanate is particularly preferable.

  Specific examples of the oxazoline compound include 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and 2,4-dimethyl-2-oxazoline. Monooxazoline compounds such as 2, bisoxazoline compounds such as 2,2 ′-(1,3-phenylene) bis (2-oxazoline), and polymers having an oxazoline group in the side chain. These oxazoline compounds may be used alone or in combination of two or more. Of these, 2,2 '-(1,3-phenylene) bis (2-oxazoline) is particularly preferable.

<Layered silicate>
The layered silicate used in the present invention is a kind of swellable layered clay mineral, and specific examples thereof include smectite, vermiculite, and swellable fluorinated mica. Examples of smectites include montmorillonite, beidellite, hectorite and saponite. 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 are montmorillonite and swellable fluorinated mica. Synthetic products may be used in addition to natural products, 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, any one of primary to quaternary ammonium ions, pyridinium ions, imidazolium ions, phosphonium ions is ionized between the layered silicate layers. Bonding is preferred. The primary to tertiary ammonium ions are those obtained by protonating the corresponding primary to tertiary amines. Examples of the primary amine include octylamine, dodecylamine, and octadecylamine. 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)- One in the molecule, such as N- (3′-dodecyloxy-2′-hydroxypropyl) methylammonium, methyldodecylbis (polyethylene glycol) ammonium, methyldiethyl (polypropyleneglycol) ammonium, 2-hydroxyethyltriphenylphosphonium Layered silicates treated with ammonium ions and phosphonium ions having the above hydroxyl groups are particularly biodegradable polyester resins. High affinity, 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 ammonium ions and phosphonium ions, followed by filtration, washing, and drying.

  When blending the layered silicate, the blending amount is preferably 0.5 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, even more preferably 100 parts by weight of the biodegradable polyester resin. Is 2-8 parts by mass. If the amount is less than 0.5 parts by mass, it is difficult to obtain an improvement effect such as gas barrier properties and moldability, which are the purpose of adding the layered silicate. Moreover, when it exceeds 20 mass parts, there exists a tendency for the deterioration of an external appearance and the molding processability by molecular weight fall etc. to arise.

<Flexibility>
The biodegradable polyester resin composition containing the biodegradable polyester resin of the present invention and the rosin alcohol alkylene oxide adduct preferably has a flexural modulus of 3.5 GPa or less measured at 23 ° C. according to ASTM-D790. . More preferably, it is 3.0 GPa or less, More preferably, it is 2.5 GPa or less, Most preferably, it is 2.0 GPa or less. By being 3.5 GPa or less, it can be suitably used for applications requiring flexibility.

  The biodegradable polyester resin composition containing the biodegradable polyester resin of the present invention, the rosin alcohol alkylene oxide adduct and the layered silicate has a flexural modulus measured at 23 ° C. according to ASTM-D790 of 4.0 GPa or less. Preferably there is. More preferably, it is 3.5 GPa or less, More preferably, it is 3.0 GPa or less, Most preferably, it is 2.5 GPa or less. When it is larger than 4.0 GPa, it becomes difficult to obtain the required flexibility when an actual molded body is formed.

<Oxygen permeability coefficient and rate of change>
The resin composition containing the biodegradable polyester resin of the present invention and the rosin alcohol alkylene oxide adduct has an oxygen permeability coefficient of 220 ml · mm / m ² / day / MPa or less at 20 ° C. and a relative humidity of 90%. Is preferred. More preferably, it is 200 ml * mm / m < ² > / day / MPa or less. When it is larger than 220 ml · mm / m ² / day / MPa, it becomes difficult to obtain a practical level of gas barrier properties when an actual molded body is formed.

The resin composition containing the biodegradable polyester resin of the present invention, the rosin alcohol alkylene oxide adduct, and the layered silicate has an oxygen permeability coefficient of 150 ml · mm / m ² / day / MPa at 20 ° C. and a relative humidity of 90%. The following is preferable. More preferably, it is 120 ml * mm / m < ² > / day / MPa or less, More preferably, it is 100 ml * mm / m < ² > / day / MPa or less. By being 150 ml * mm / m < ² > / day / MPa or less, it can be used for the use by which a gas barrier property is requested | required more.

The biodegradable polyester resin composition of the present invention preferably has an oxygen permeability coefficient change rate represented by the following formula of 120% or less.
Oxygen transmission coefficient change rate [%] = X / Y × 100
However,
X: Oxygen permeability coefficient of biodegradable polyester resin composition containing rosin alcohol alkylene oxide adduct at 20 ° C. and 90% relative humidity Y: 20 of biodegradable polyester resin composition not containing rosin alcohol alkylene oxide adduct It is an oxygen transmission coefficient at a temperature of 90 ° C. and a relative humidity of 90%. The closer this value is to 100%, the more the gas barrier property of the base biodegradable polyester resin composition is not impaired.

<Molecular weight retention>
In the present invention, a resin composition containing 0.01 to 5 parts by mass of at least one terminal blocker selected from a carbodiimide compound, an epoxy compound, an isocyanate compound, and an oxazoline compound is represented by the following formula, 40 ° C. The molecular weight retention after the wet heat treatment for 300 hours at 90% relative humidity is preferably 90% or more.

Molecular weight retention (%) = C / D × 100
However,
C: Weight average molecular weight after wet heat treatment test D: Weight average molecular weight before wet heat treatment test. The closer this value is to 100%, the higher the heat and moisture resistance. More preferably, it is 95% or more.

<Transparency / Appearance>
Since the resin composition of the present invention is obtained by adding a rosin alcohol alkylene oxide adduct to a biodegradable polyester resin, it has excellent appearance due to excellent transparency, and a molded body having a thickness of 1 mm has a haze of 30% or less. It becomes. When the haze is larger than this value, the transparency is insufficient and the commercial value may be lowered. Haze refers to turbidity measured with a turbidimeter. The larger the haze, the stronger the turbidity, and the smaller the haze, the weaker the turbidity and the clearer it is. In a molded body having a thickness of 1 mm, the haze is preferably 30% or less, more preferably 25% or less, still more preferably 20% or less, and most preferably 15% or less.

  In the resin composition of the present invention, when a rosin alcohol alkylene oxide adduct and a layered silicate are used in combination, the appearance is excellent due to excellent transparency, dispersibility of the layered silicate, etc. There are no aggregates that can be visually confirmed, and the haze is 45% or less. When the haze is larger than this value, the commercial value may be lowered because of insufficient transparency or coarse agglomerates even when the haze is not so large. In a molded body having a thickness of 1 mm, the haze is preferably 45% or less, more preferably 35% or less, still more preferably 30% or less, and most preferably 25% or less.

<Manufacturing method>
In the production of the biodegradable polyester resin composition of the present invention, as a method for adding the rosin alcohol alkylene oxide adduct, a method of adding at the time of polymerization of the biodegradable polyester resin, a method of adding at the time of melt kneading of the resin, Examples include a method of adding at the time of molding. At this time, a method of adding pellets in which the rosin alcohol alkylene oxide adduct is adjusted to a high concentration in advance, that is, a so-called master batch method may be used. The preferred addition time is at the time of melt-kneading or molding. As an addition method when adding at the time of melt-kneading or molding, after dry blending with the biodegradable polyester resin in advance, a method of supplying to a general kneader or molding machine, using a side feeder, etc. Examples thereof include a method of adding from the middle of the kneader and a method of pouring with a fixed supply pump in a heated and melted state.

  In the production of the biodegradable polyester resin composition of the present invention, as an addition method when the rosin alcohol alkylene oxide adduct, the end-blocking agent and the layered silicate are used in combination, these are biodegradable polyester resins. A method of adding at the time of polymerization, a method of adding at the time of melt kneading the resin, a method of adding at the time of molding, and the like. The addition order at this time is 2 of the first stage in which the biodegradable polyester resin and the end-capping agent are reacted first, and then the second stage in which the rosin alcohol alkylene oxide adduct and the layered silicate are added. A method comprising steps is preferred. As the rosin alcohol alkylene oxide adduct and the layered silicate, a master batch as described above may be used. The preferred addition time is at the time of melt-kneading or molding. As an addition method in the case of adding at the time of melt-kneading or molding, a resin and a terminal blocking agent are dry-blended in advance and then supplied to a general kneader or molding machine, and then a side feeder, etc. A method of adding the rosin alcohol alkylene oxide adduct and the layered silicate from the middle of the kneading machine using the above is preferable.

  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 the additive, it is preferable to use a twin screw extruder.

  In the biodegradable polyester resin composition of the present invention, a heat stabilizer, an antioxidant, a pigment, a dye, a light-proofing agent, a weathering agent, a difficulty, other than those prescribed in the present invention, within a range not impairing the effects of the present invention. A flame retardant, a lubricant, a release agent, an antistatic agent, a filler, a plasticizer, a dispersant, and the like may be added. Examples of heat stabilizers and antioxidants include phosphite organic compounds, hindered phenol compounds, benzotriazole compounds, triazine compounds, hindered amine compounds, sulfur compounds, copper compounds, alkali metal halides, or these. Mixtures can be used. These additives can generally be added at the time of melt-kneading or polymerization. Among the fillers, inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass Examples include balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, glass fiber, and carbon fiber. Examples of the organic filler include monosaccharides, polysaccharides such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, kenaf, and other naturally occurring polymers, modified products thereof, and high-strength fibers. .

  In addition, the biodegradable polyester resin composition of the present invention is not limited to polyester amide, polyester carbonate, polyamide (nylon), polyethylene, polypropylene, polybutadiene, polystyrene, AS resin, ABS resin, poly (unless the effects of the present invention are impaired. Acrylic acid), poly (acrylic acid ester), poly (methacrylic acid), poly (methacrylic acid ester), polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate and copolymers thereof A non-biodegradable resin such as 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.

  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 biodegradable polyester resin composition, preferably 180 to 230 ° C, more preferably 190 to 220 ° C. is there. 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 composition 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. Moreover, in order to promote crystallization for the purpose of improving rigidity and heat resistance, the temperature may be Tg or more and (Tm−30 ° C.) or less. Alternatively, after molding, the molded product can be heat-treated at a temperature of Tg or more and Tm or less.

  Examples of the blow molding method include a direct blow method in which molding is performed immediately after melting raw material chips, and an injection blow molding method in which blow molding is performed after molding a preform (bottomed parison) by injection molding. In addition, any of a hot parison method in which blow molding is continuously performed after molding of a preformed body, and a cold parison method in which blow molding is performed by once cooling and taking out the preformed body and then performing blow molding can be employed. Further, the stretching method is not particularly limited, and a sequential biaxial stretching method or a simultaneous biaxial stretching method can be selected according to the parison and the molding method. In order to promote crystallization for the purpose of improving rigidity, heat resistance, and barrier properties, the blow mold temperature can be molded at Tg or higher and (Tm-30 ° C.) or lower. Heat treatment can be performed at a temperature not lower than Tm and not higher than Tm.

  As the extrusion molding method, a T-die method, a round die method, or the like can be applied. The extrusion temperature must be Tm or higher or the flow start temperature or higher, preferably 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 resin composition is decomposed, and problems such as a decrease in strength and coloring of the extruded product occur. Films, sheets, pipes, and the like can be produced by extrusion molding.

  The method for producing the film is not particularly limited, and examples thereof include a T-die method, an inflation method, a tubular stretching method, and a calendar method. In production, the biodegradable polyester resin composition is heated and melted using an extruder. Furthermore, if necessary, other additives such as antistatic agents and lubricants can be blended in appropriate amounts.

  Examples of the extruder include a single screw extruder, a twin screw extruder, a roll kneader, and a Brabender. Of these, it is preferable to use a twin screw extruder in consideration of dispersibility when adding a layered silicate during film production. The extruder is heated to, for example, a cylinder temperature of 180 to 260 ° C. and a T die temperature of 200 to 250 ° C., melt kneaded and extruded, and stretched with a cooling roll controlled to 10 to 50 ° C. A stretched film can be obtained. As a biaxial stretching method for an unstretched film, either a sequential biaxial stretching method in which stretching is performed in the transverse direction or the longitudinal direction after stretching in the longitudinal direction or the transverse direction, or a simultaneous biaxial stretching method in which the stretching treatment is performed simultaneously in the longitudinal and transverse directions But you can.

  Although extending | stretching temperature is not specifically limited, It is preferable that it is the range of glass transition temperature Tg- (Tg + 50) degreeC of a biodegradable polyester resin composition. The stretching ratio is not particularly limited, but considering the mechanical properties, the longitudinal stretching ratio is set in the range of 1.5 times to 8.0 times, and the lateral stretching ratio is 1.5 times to 8.0 times. It is preferable to carry out a stretching treatment as the range. The obtained stretched film is subsequently heat-treated at a temperature of 100 ° C. to 150 ° C. in the same tenter and subjected to a relaxation treatment as necessary. The obtained stretched film may be taken out once and then heat treated.

  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 resin composition is decomposed, resulting in uneven thickness or orientation. It may break down and impact resistance may decrease. Further, for the purpose of improving the rigidity, heat resistance and barrier property of the molded container, heat treatment may be performed at a temperature of Tg or more and Tm or less in order to promote crystallization. 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 applications.

  Other molded articles produced using the biodegradable polyester resin composition of the present invention include dishes such as dishes, bowls, bowls, chopsticks, spoons, forks and knives; containers for fluids; caps for containers; rulers Office supplies such as writing instruments, clear cases, CD cases; triangular items for kitchens, trash cans, washbasins, toothbrushes, combs, hangers, etc .; various toys such as plastic models; for electrical appliances such as air conditioner panels and various cases Resin parts; automotive resin parts such as bumpers, instrument panels and door trims.

  In addition, although the form of the container for fluid 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, alcoholic beverages, etc .; temporary storage containers for seasonings such as soy sauce, sauces, mayonnaise, ketchup, edible oils; shampoos And containers such as rinses; cosmetic containers; agricultural chemical containers and the like. It is preferable that the resin composition has flexibility because squeeze properties are exhibited when the resin composition is formed into a container shape.

  The biodegradable polyester 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 needs to be Tm or higher of the biodegradable polyester composition, and 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. After stretching, heat treatment can also be performed for the purpose of relaxing internal strain, preventing shrinkage, promoting crystallization, and stabilizing strength. As a heat treatment method, a known method such as contacting with a heating plate or passing through a heating medium under tension or no tension can be appropriately employed.

  The fibers obtained by the above method are used as clothing fibers, industrial material fibers, short fiber nonwoven fabrics, and the like.

  The biodegradable polyester 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.

  The method used for evaluation of the following Examples and Comparative Examples is as follows.

(1) Flexural modulus:
The resin composition was injection-molded to obtain a molded piece of length × width × thickness = 127 mm (5 inches) × 12.7 mm (1/2 inch) × 3.2 mm (1/8 inch). The bending elastic modulus was measured by applying a load at a deformation rate of 1 mm / min according to ASTM-D790. The injection molding conditions of the test piece were as follows. That is, using an injection molding machine (IS-80G type manufactured by Toshiba Machine Co., Ltd.), cylinder temperature 190-170 ° C., mold temperature 15 ° C., injection pressure 60%, injection speed 60%, injection time 20 seconds, cooling time 20 seconds. The interval was set to 2 seconds, and molding was performed using an ASTM standard 1/8 inch three-point bending test piece mold.

(2) Gas barrier properties (2-1) Oxygen permeability coefficient:
Using a differential pressure type gas / gas permeability measuring device (Yanaco, GTR-30XAU) for a heat-pressed sheet previously conditioned under conditions of 20 ° C. and 90% relative humidity, oxygen was measured by the differential pressure method. The transmittance was measured. The oxygen permeability was a value obtained from three measurement points with measurement times of 0.5 h, 1 h, and 2 h.

The oxygen transmission coefficient is
(Oxygen permeability coefficient) = (Oxygen permeability) × (Sample thickness)
Calculated from This value is an index of gas barrier properties, and the smaller the value, the better the gas barrier properties.

(2-2) Oxygen permeability coefficient change rate:
The rate of change was calculated by the method described above. When the rate of change was 120% or less, it was judged as good, and when it exceeded 120%, it was judged as bad.

  In addition, as the value of Y in each Example and Comparative Example, that is, the oxygen permeability coefficient at 20 ° C. and 90% relative humidity of the biodegradable polyester resin composition not containing the rosin alcohol alkylene oxide adduct, Examples 1-3 And in Comparative Example 3, the value of Comparative Example 1, in Examples 4-7 and Comparative Example 4, the value of Comparative Example 2, in Examples 8-12 and Comparative Example 7, the value of Comparative Example 5, and in Example 13 In -15 and Comparative Example 8, the values of Comparative Example 6 were used.

(3) Appearance evaluation (3-1) Haze A press sheet having a thickness of 1 mm was measured according to JIS K-7136. That is, using a desktop test press machine manufactured by Tester Sangyo Co., Ltd., the resin composition pellets were pressed at 190 ° C. for about 3 minutes, and then rapidly cooled to produce a 1 mm thick press sheet as a molded body. The press sheet was measured using an NDH-2000 type turbidity / cloudiness meter manufactured by Nippon Denshoku Industries Co., Ltd.

(3-2) Transparency of press sheet:
Regarding the composition to which layered silicate was added, visual evaluation of a 1 mm-thick molded product was performed, and a product having a lot of aggregates was evaluated as bad (x), and a product having almost no aggregates was evaluated as good (◯). When the aggregate was not confirmed at all, it was evaluated as the best (◎).

(4) Weight average molecular weight (Mw) of resin composition
Using a gel permeation chromatography apparatus (manufactured by Shimadzu Corp.) equipped with a differential refractive index detector (manufactured by Shimadzu Corp., RID-10A), tetrahydrofuran (THF) as an eluent and a flow rate of 1.0 ml / min at 40 ° C. It was measured. As columns, SHODEX KF-805L and KF-804L (manufactured by Showa Denko KK) were used. The sample was dissolved in 0.5 ml of chloroform after dissolving 10 mg of the resin composition, diluted with 5 ml of THF, filtered through a 0.45 μm filter, and then used for measurement. The molecular weight was converted using polystyrene (manufactured by Waters) as a standard sample.

(5) Glass transition temperature (Tg):
Using a DSC apparatus (DSC7, manufactured by PerkinElmer Co., Ltd.), the temperature was raised from 20 ° C. to 200 ° C. at + 20 ° C./min and held for 5 minutes, then cooled from 200 ° C. to −50 ° C. at −20 ° C./min to 5 Hold for a minute. Furthermore, the glass transition temperature in the process (2nd Scan) in which the temperature was raised again from −50 ° C. to 200 ° C. at + 20 ° C./min was defined as Tg of the resin composition.

(6) Moisture and heat resistance evaluation:
Using a thermo-hygrostat (Yamato Scientific Co., Ltd., IG400), the molded piece produced in (1) was stored for 300 hours in an environment of a temperature of 40 ° C. and a relative humidity of 90%. Using the test piece after the treatment, the flexural modulus was measured by the same method as (1), the Tg was measured by the same method as (5), and the molecular weight was measured by the same method as (4). Furthermore, calculation of molecular weight retention and bleed-out evaluation were performed as follows.

・ Molecular weight retention (%)
(Molecular weight retention) = (Weight average molecular weight of the resin composition after treatment) / (Weight average molecular weight of the resin composition before treatment) × 100
Calculated with

・ Bleed-out evaluation:
Observe the appearance of the above-mentioned bend-formed pieces, evaluate those with a lot of eluate as bad (x), evaluate those with almost no eluate as good (○), and cannot confirm the eluate at all Was evaluated as the best (◎). Moreover, although elution was not seen, the thing which whitened as a whole and the transparency was impaired was also evaluated as bad (x).

[material]
Next, various raw materials used in the following Examples and Comparative Examples are shown.

(1) Biodegradable polyester resin Polylactic acid (polylactic acid manufactured by NatureWorks, weight average molecular weight (Mw) = 190,000, melting point 170 ° C., D-form content 1.3 mol%, MFR 3.5 g / 10 min)

(2) Rosin alcohol alkylene oxide adduct Examples of production are shown in detail below.

In the following, “PO” means propylene oxide, “EO” means ethylene oxide, and “BO” means butylene oxide.
The addition order of alkylene oxide is as follows. For example, “Rosin alcohol + 19 mol PO block + 25 mol EO block” in Production Example 3 indicates that 19 mol PO is added to rosin alcohol first, followed by 25 mol EO.

[Production Example 1]
Additive 1: Molecular weight 2,400, rosin alcohol + EO block 45 mol Into a 5 liter autoclave equipped with a stirrer, nitrogen and alkylene oxide introduction tube, 500 g of rosin alcohol (Eastman Chemical Co., Abitol E), The catalyst was charged with 3.4 g of potassium hydroxide as a catalyst, and the inside of the autoclave was replaced with nitrogen gas. While stirring this, the pressure was kept at 0.7 MPa or less at around 140 ° C., and 2893 g of ethylene oxide was introduced over 5 hours or more. After the introduction, aging was performed for 3 hours or more, and it was confirmed that there was no pressure drop, and the aging was completed. After aging, cool to 100 ° C, put 5 liters of aluminum silicate (Kyowa Kagaku Kogyo Co., Ltd., Kyoward 700SL) as an adsorbent into the autoclave, remove the catalyst by adsorption and filter the contents in the 5 liter autoclave. Thus, additive 1 was obtained.

[Production Example 2]
Additive 2: Molecular weight 2,500, rosin alcohol + EO block 25 mole + PO block 19 mole 7.3 g of potassium hydroxide was used as a catalyst, 1572 g of ethylene oxide was introduced, and 1572 g of propylene oxide was further introduced. Otherwise in the same manner as in Production Example 1, additive 2 was obtained.

[Production Example 3]
Additive 3: Molecular weight 2,500, rosin alcohol + PO block 19 mol + EO block 25 mol 7.3 g of potassium hydroxide was used as a catalyst, 1572 g of propylene oxide was introduced, and 1572 g of ethylene oxide was further introduced. Otherwise in the same manner as in Production Example 1, additive 3 was obtained.

[Production Example 4]
Additive 1 produced in Production Example 1 was dimerized to obtain Additive 4: Molecular weight 5000, rosin alcohol + EO block 90 mol.

[Production Example 5]
Additive 5: Molecular weight 2,500, rosin alcohol + PO block 8 mol + EO block 37 mol 7.3 g of potassium hydroxide was used as a catalyst, 723 g of propylene oxide was introduced, and 2421 g of ethylene oxide was further introduced. Otherwise in the same manner as in Production Example 1, additive 5 was obtained.

[Production Example 6]
Additive 6: Random copolymerization of molecular weight 2,500, rosin alcohol + PO 8 mol / EO 37 mol 7.3 g of potassium hydroxide was used as a catalyst, and 2421 g of ethylene oxide and 723 g of propylene oxide were simultaneously introduced. Otherwise in the same manner as in Production Example 1, additive 6 was obtained.

[Production Example 7]
Additive 7: Molecular weight 2,500, rosin alcohol + EO block 46 mol + PO block 1 mol 7.3 g of potassium hydroxide was used as a catalyst, 3060 g of ethylene oxide was introduced, and 85 g of propylene oxide was further introduced. Otherwise in the same manner as in Production Example 1, additive 7 was obtained.

[Production Example 8]
Additive 8: molecular weight 7,500, rosin alcohol + PO block 18 mol + EO block 138 mol 11.5 g of potassium hydroxide as a catalyst, 1573 g of propylene oxide were introduced, and after complete aging, 1505 g was extracted, and the residue was further removed. 2480 g of ethylene oxide was introduced. Otherwise in the same manner as in Production Example 1, additive 8 was obtained.

[Production Example 9]
Additive 9: molecular weight 7,500, rosin alcohol + BO block 23 mol + EO block 125 mol Potassium hydroxide as catalyst 15 g, butylene oxide 2400 g was introduced and after complete aging, 2125 g was extracted, and ethylene oxide was further removed from the residue. 2200 g was introduced. Otherwise in the same manner as in Production Example 1, additive 9 was obtained.

[Production Example 10]
Additive 10: Molecular weight 5,000, rosin alcohol + EO block 105 mol Potassium hydroxide as catalyst 7.3 g, ethylene oxide 2900 g was introduced and after complete aging, 1862 g was extracted, and ethylene oxide 1764 g was further added to the residue. Introduced. Otherwise in the same manner as in Production Example 1, additive 10 was obtained.

[Production Example 11]
Additive 11: Rosin ester compound (molecular weight 1,300)
Into a 1 liter reaction vessel equipped with a condenser and a stirrer, 302.0 g of rosin (containing about 80% dehydroabietic acid) was heated and melted, and polyethylene glycol (average molecular weight 1,000, manufactured by Sanyo Chemical Co., Ltd.) After 1850 g of PEG-1000) was added dropwise at 150 ° C. over 1 hour, 1.8 g of triphenyl phosphite (0.6 parts by mass with respect to 100 parts by mass of rosin) was added dropwise. After completion of dropping, the temperature was raised to 280 ° C. and stirred for 24 hours. Finally, the unreacted product was distilled off under reduced pressure to obtain Additive 11.

(3) Layered silicate Swelling synthetic fluorinated mica in which interlayer ions are substituted with dihydroxyethylmethyldodecylammonium ions (Coop Chemical Co., Somasif MEE, average particle size 6.2 μm)

(4) Endblocker N, N'-di-2,6-diisopropylphenylcarbodiimide (Rheinhemy, Stavaxol I)

(5) Antioxidant Phosphite-based antioxidant: hydrogenated bisphenol A / pentaerythritol phosphite polymer (JPH-3800, manufactured by Johoku Chemical Industry Co., Ltd.)

[Production of resin]
For melt kneading, a PCM-30 type twin screw extruder manufactured by Ikegai Co., Ltd. was used. Screw diameter is 30mm
φ and average groove depth were 2.5 mm.

Example 1
90 parts by mass of polylactic acid and 10 parts by mass of additive 1 produced in Production Example 1 were dry blended, and using the above extruder, 190 ° C., screw rotation speed 200 rpm (= 3.3 rps), Melt kneading was performed at a residence time of 1.6 minutes, extrusion, processing into pellets, and drying to obtain a resin composition. The evaluation results of the obtained composition are shown in Table 1.

Examples 2-7
The composition was changed as shown in Table 1 with respect to Example 1. Other than that, various evaluations were performed after obtaining a resin composition as in Example 1. In Examples 4 to 7, the end-capping agent was dry blended simultaneously with polylactic acid and each additive. The results are shown in Table 1.

Comparative Examples 1-4
The composition was changed as shown in Table 2 with respect to Example 1. Other than that, various evaluations were performed after obtaining a resin composition as in Example 1. In Comparative Examples 2 and 4, the end-capping agent was dry blended simultaneously with polylactic acid and each additive. The results are shown in Table 2.

Example 8
86.4 parts by mass of polylactic acid, 9.6 parts by mass of additive 1 prepared in Production Example 1 and 4 parts by mass of layered silicate were dry-blended, and the above extruder was used. Melting and kneading were performed at a temperature of 200 ° C., a screw rotational speed of 200 rpm (= 3.3 rps), and a residence time of 1.6 minutes, extrusion, processing into a pellet, and drying to obtain a resin composition. The evaluation results of the obtained composition are shown in Table 2.

Examples 9-15
The composition was changed as shown in Table 3 with respect to Example 8. Other than that, various evaluations were performed after obtaining a resin composition as in Example 8. In Examples 13 to 15, the end-capping agent and the antioxidant were dry blended simultaneously with polylactic acid and each additive. The results are shown in Table 3.

Comparative Examples 5-9
The composition was changed as shown in Table 4 with respect to Example 8. Other than that, various evaluations were performed after obtaining a resin composition as in Example 8. In Comparative Examples 6 and 8 to 9, the end-capping agent and the antioxidant were dry blended simultaneously with polylactic acid and each additive. The results are shown in Table 4.

  The resin compositions of Examples 1 to 7 were good because the flexural modulus decreased and showed flexibility, and the oxygen permeability coefficient and the rate of change thereof, which are indicators of gas barrier properties, were low. Furthermore, the bleed-out evaluation after 40 ° C. and 90% RH for 300 hours was also good.

  Since the resin compositions of Comparative Examples 1 and 2 did not contain an alkylene oxide adduct of rosin alcohol, the flexural modulus was high, and no flexibility was exhibited.

  Since the rosin ester compound was added to the resin composition of Comparative Example 3, the molecular weight of the rosin ester compound was 5,000 or less, but the molecular weight of the resin composition after kneading was reduced. Furthermore, a decrease in molecular weight and bleed-out after 300 hours at 40 ° C. and 90% RH were remarkable.

  Since the resin composition of Comparative Example 4 used an alkylene oxide adduct of rosin alcohol having a molecular weight exceeding 5,000, gas barrier properties were poor, and bleeding out after 300 hours at 40 ° C. and 90% RH was remarkable. Met.

  The resin compositions of Examples 8 to 15 were good because the flexural modulus decreased and showed flexibility, and the oxygen permeability coefficient, which is an indicator of gas barrier properties, and the rate of change thereof were low. Furthermore, the bleed-out evaluation after 40 ° C. and 90% RH for 300 hours was also good.

  On the other hand, since the resin compositions of Comparative Examples 5 to 6 did not contain the alkylene oxide adduct of rosin alcohol, the flexural modulus was high and the flexibility was not exhibited.

  Since the rosin ester compound was added to the resin composition of Comparative Example 7, the molecular weight of the rosin ester compound was 5,000 or less, but the molecular weight of the resin composition after kneading was reduced. Furthermore, a decrease in molecular weight and bleed-out after 300 hours at 40 ° C. and 90% RH were remarkable.

  Since the resin compositions of Comparative Examples 8 to 9 were obtained by using an alkylene oxide adduct of rosin alcohol having a molecular weight exceeding 5,000, the gas barrier property was poor, and the molded piece was molded at 40 ° C. and 90% RH after 300 hours. Whitening was remarkable and transparency was impaired.

  Since the resin compositions of Examples 4 to 7 and 13 to 15 contained a terminal blocking agent, the molecular weight retention after wet heat treatment reached 95% or more, and the heat and moisture resistance was good.

Claims (14)

A biodegradable polyester resin composition comprising a biodegradable polyester resin and a rosin alcohol alkylene oxide adduct satisfying the following (A) and (B).
(A) Molecular weight of 1,000 or more and 5,000 or less.
(B) A random copolymer in which the alkylene oxide is a block selected from at least one of ethylene oxide, propylene oxide, and butylene oxide, or at least two.   The content of 0.01 to 5 parts by mass of at least one terminal blocker selected from a carbodiimide compound, an epoxy compound, an isocyanate compound, and an oxazoline compound is contained with respect to 100 parts by mass of the biodegradable polyester resin. Biodegradable polyester resin composition.   The biodegradable polyester resin composition according to claim 1 or 2, wherein the biodegradable polyester resin is polylactic acid.   The biodegradable polyester resin composition according to any one of claims 1 to 3, comprising 0.5 to 20 parts by mass of a layered silicate with respect to 100 parts by mass of the biodegradable polyester resin.   The biodegradable polyester resin according to claim 4, wherein the layered silicate is one in which any one of primary to quaternary ammonium ions, pyridinium ions, imidazolium ions, and phosphonium ions is ion-bonded between the layers. Composition.   The biodegradable polyester resin composition according to any one of claims 1 to 3, wherein the flexural modulus measured at 23 ° C according to ASTM-D790 is 3.5 GPa or less.   6. The biodegradable polyester resin composition according to claim 4, wherein the flexural modulus measured at 23 ° C. according to ASTM-D790 is 4.0 GPa or less. The biodegradable polyester according to any one of claims 1, 2, 3, and 6, wherein an oxygen permeability coefficient at 20 ° C and a relative humidity of 90% is 220 ml · mm / m ² / day / MPa or less. Resin composition. 8. The biodegradable polyester resin composition according to claim 4, wherein the oxygen permeability coefficient at 20 ° C. and a relative humidity of 90% is 150 ml · mm / m ² / day / MPa or less. The raw material according to any one of claims 2 to 9, wherein the molecular weight retention represented by the following formula is 90% or more after the wet heat treatment at 40 ° C and 90% relative humidity for 300 hours. Degradable polyester resin composition.
Molecular weight retention (%) = C / D × 100
Where C: weight average molecular weight after wet heat treatment test
D: Weight average molecular weight before wet heat treatment test   When producing the biodegradable polyester resin composition according to any one of claims 1, 2, 3, 6, 8, and 10, a rosin alcohol alkylene oxide adduct is added during melt-kneading or molding. A method for producing a biodegradable polyester resin composition.   A method for producing the biodegradable polyester resin composition according to any one of claims 4, 5, 7, 9, and 10, wherein the biodegradable polyester resin composition is produced during melt-kneading or molding. The biodegradability is characterized by having a two-stage process comprising a first stage in which the end-capping agent is first reacted with a rosin alcohol alkylene oxide adduct and a layered silicate. A method for producing a polyester resin composition.   A molded body characterized by being formed of the biodegradable polyester resin composition according to any one of claims 1 to 10.   The molded body according to claim 13, which is a container.