JP2015071714A - Method for producing aliphatic polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aliphatic polyester resin composition production method which has sufficient molecular weight during production, excellent in mechanical strength, and which reduces molecular weight quickly in underground, underwater, or under humidity conditions, namely under a relatively mild temperature environment.SOLUTION: The aliphatic polyester resin composition is produced by melting and kneading 0.1-5 parts by mass of an organic phosphorous compound (B) and/or a sulfonic acid ester compound (C) with respect to 100 parts by mass of aliphatic polyester resin (A) at 90-185°C.

Description

  The present invention relates to a method for producing an aliphatic polyester resin composition, and more particularly, to a method for producing an aliphatic polyester resin composition with controlled degradation characteristics under humid conditions.

  Biodegradable resins such as aliphatic polyesters are used in films, sheets, fibers, molded products, etc. for the purpose of reducing the environmental burden. However, in applications that require rapid degradation after use, such as agricultural applications, soil reforming applications, and underground resource mining applications such as oil and gas, the mechanical strength required in the initial use and the decomposition rate required after use are It is difficult to achieve both, which is a challenge.

  Conventionally, for the purpose of improving the color tone, heat stability, wet heat resistance, and moldability of a resin, it has been proposed to blend an organic phosphorus compound during polymerization or by melt kneading (for example, Patent Documents 1 to 5). On the other hand, Patent Document 6 proposes adding a sulfonic acid compound to a thermoplastic polyester resin to impart flame retardancy.

JP 2001-49097 A Special table 2008-520806 JP 2006-249152 A International Publication No. 06/118096 International Publication No. 10/053167 JP 2007-179712 A

  However, in Patent Documents 1 to 5, it is suggested that hydrolysis resistance decreases when the amount of the organophosphorus compound is large, but the decomposition characteristics required by the present inventors have not been obtained. This is the actual situation. In addition, if a large amount of a phosphorus stabilizer is added during polymerization of an aliphatic polyester for the purpose of improving the color tone of the resin or maintaining the molecular weight, an aliphatic polyester having a sufficient degree of polymerization may not be obtained or the color tone may not be stable. There was a problem. Patent Document 6 does not describe the degradability of polyester.

  The present invention provides a method for producing an aliphatic polyester resin composition in which such problems of the prior art are solved, that is, a simple production method, has a sufficient molecular weight at the time of production, and is excellent in mechanical strength. It is an object of the present invention to provide a method for producing an aliphatic polyester resin composition having controlled decomposition characteristics under such humid conditions as described above.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have a sufficient molecular weight at the time of production by melt-kneading a certain amount of an organophosphorus compound and / or a sulfonate compound in an aliphatic polyester resin. The present inventors have found that an aliphatic polyester resin composition having controlled decomposition characteristics under humid conditions such as soil and water can be produced. The present invention has been accomplished based on these findings.

That is, the gist of the present invention is as follows (1) to (9).
(1) Melting and kneading 0.1 to 5 parts by mass of an organic phosphorus compound (B) and / or a sulfonic acid ester compound (C) with respect to 100 parts by mass of an aliphatic polyester resin (A). A method for producing an aliphatic polyester resin composition.
(2) The aliphatic polyester resin (A) contains an aliphatic polyester mainly composed of a diol and a dicarboxylic acid, and when the content is 100 parts by mass of the entire aliphatic polyester resin (A), It is 50-100 mass parts, The manufacturing method as described in (1) characterized by the above-mentioned.
(3) The production method according to (1) or (2), wherein the diol is 1,4-butanediol and the dicarboxylic acid is succinic acid.
(4) The production method according to any one of (1) to (3), wherein the organophosphorus compound (B) is a compound represented by the following formula (8).

[In Formula (8), X shows a hydrogen atom or OH, n shows the integer of 1-20, m shows 1 or 2. ]

(5) The production method according to any one of (1) to (4), wherein the aliphatic polyester resin (A) has an intrinsic viscosity (IV) of 0.6 to 1.8.
(6) The aliphatic polyester resin (A) contains an aliphatic polyester mainly composed of oxycarboxylic acid, and the content thereof is 1 to 50 masses when the entire aliphatic polyester resin (A) is 100 mass parts. The production method according to any one of (1) to (5), wherein
(7) The production method according to any one of (1) to (6), wherein the aliphatic polyester resin composition has an intrinsic viscosity (IV) of 0.6 to 1.8.
(8) The production method according to any one of (1) to (7), wherein the aliphatic polyester resin composition has an intrinsic viscosity retention of 60 to 100% with respect to the aliphatic polyester resin (A).
(9) The production method according to any one of (1) to (8), wherein the aliphatic polyester resin composition is used as a filler for pores for underground resource mining.

  The aliphatic polyester resin composition (hereinafter sometimes referred to as “resin composition according to the present invention”) obtained by the production method of the present invention has a sufficient molecular weight at the time of production, and therefore has excellent mechanical properties. . In addition, it has controlled decomposition characteristics under humid conditions such as soil and water, that is, its molecular weight decreases rapidly even under mild temperature conditions. Particularly useful for certain applications.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention. In addition, in this specification, when the expression “to” is used, it is used in a sense including numerical values or physical values before and after that.

The manufacturing method of the aliphatic polyester resin composition of this invention is 0.1-5 mass of organophosphorus compound (B) and / or sulfonate compound compound (C) with respect to 100 mass parts of aliphatic polyester resin (A). The part is characterized by being melt-kneaded at a temperature of 90 to 185 ° C.
In the present invention, the organophosphorus compound (B) and / or the sulfonic acid ester compound (C) has a function as a decomposition accelerator for the aliphatic polyester resin (A). The organophosphorus compound (B) and the sulfonate compound (C) can be used in any ratio and combination as a decomposition accelerator.

1. Aliphatic polyester resin (A)
In the present invention, the aliphatic polyester resin (A) is not particularly limited as long as the molar ratio of the aliphatic structure is a maximum ratio with respect to the entire structure. For example, the aliphatic polyester resin (A) is partially aromatic in addition to the aliphatic structure. It may be an aliphatic aromatic polyester having a group structure. More specifically, for example, an aliphatic polyester mainly composed of diol and dicarboxylic acid, an aliphatic polyester mainly composed of oxycarboxylic acid (hydroxycarboxylic acid), and an aliphatic fragrance mainly composed of diol and dicarboxylic acid. Group polyesters, and mixtures thereof. Of these, aliphatic polyesters mainly composed of diol and dicarboxylic acid are preferred.

  Here, “being as a main component” means that the monomer component is obtained by polymerization reaction using 50 mol% or more of each monomer component. The amount of each monomer component used is preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more.

1.1. Aliphatic polyester mainly composed of diol and dicarboxylic acid The aliphatic polyester mainly composed of diol and dicarboxylic acid is an aliphatic diol unit represented by the following formula (1) and a fat represented by the following formula (2). An aliphatic polyester resin comprising an aliphatic dicarboxylic acid unit.

—O—R ¹¹ —O— (1)
[In the formula (1), R ¹¹ represents a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group which may have an oxygen atom in the chain, If it is, it is not limited to one type. ]

—OC—R ²¹ —CO— (2)
[In the formula (2), R ²¹ represents a direct bond or a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, It is not limited to one type. ]

  Although it does not specifically limit as aliphatic diol which gives the diol unit of Formula (1), From a viewpoint of a moldability or mechanical strength, a C2-C10 aliphatic diol is preferable and a C4-C6 aliphatic diol. Is particularly preferred. Specifically, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptane Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,2-cyclohexanediol, 1, Examples include 4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 1,4-butanediol is particularly preferable. The above aliphatic diols may be used alone or in combination of two or more in any ratio and combination.

  Although it does not specifically limit as a dicarboxylic acid component which gives the dicarboxylic acid unit of Formula (2), A C2-C40 aliphatic dicarboxylic acid is preferable and a C4-C10 aliphatic dicarboxylic acid is especially preferable. Specific examples include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and dimer acid. Of these, succinic acid, adipic acid and sebacic acid are preferred, succinic acid and adipic acid are more preferred, and succinic acid is particularly preferred. The above aliphatic dicarboxylic acids may be used alone or in combination of two or more in any ratio and combination.

  Specific examples of the aliphatic polyester mainly composed of diol and dicarboxylic acid include polybutylene succinate, polybutylene succinate adipate, and the like.

  When the aliphatic dicarboxylic acid is succinic acid, by setting the amount of structural units derived from succinic acid within a predetermined range, when used in applications where rapid degradation is required after use, moderate biodegradability is obtained. It becomes possible. The proportion of structural units derived from succinic acid in the total aliphatic dicarboxylic acid units is preferably 50 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%.

  Further, when the aliphatic dicarboxylic acid is succinic acid and adipic acid, moderate biodegradability under normal conditions is possible by setting the amount of structural units derived from succinic acid and adipic acid within a predetermined range, and resistance to It becomes easier to impart impact properties. The proportion of structural units derived from succinic acid in the total aliphatic dicarboxylic acid units is preferably 50 to 95 mol%, more preferably 60 to 93 mol%, still more preferably 70 to 90 mol%, and the total aliphatic dicarboxylic acid The ratio of the structural unit derived from adipic acid in the unit is preferably 5 to 50 mol%, more preferably 7 to 40 mol%, still more preferably 10 to 30 mol%.

  Furthermore, the aliphatic polyester resin mainly comprising diol and dicarboxylic acid in the present invention may have a repeating unit derived from aliphatic oxycarboxylic acid (aliphatic oxycarboxylic acid unit). Specific examples of the aliphatic oxycarboxylic acid that gives an aliphatic oxycarboxylic acid unit include, for example, lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, 3-hydroxyvaleric acid, malic acid, citric acid, etc., or lower Examples thereof include alkyl esters and intramolecular esters. In addition, lactone compounds such as ε-caprolactone are also included in the aliphatic oxycarboxylic acid in the present invention. When optical isomers exist in these, any of D-form, L-form and racemic form may be sufficient, and the form may be solid, liquid, or aqueous solution. Of these, lactic acid, glycolic acid, malic acid, and citric acid are particularly preferred. One of these aliphatic oxycarboxylic acids may be used alone, or two or more thereof may be used in any ratio and combination.

  The amount of the aliphatic oxycarboxylic acid unit is preferably 20 mol% or less, more preferably 10 mol% or less, and still more preferably in the total aliphatic dicarboxylic acid unit of the aliphatic polyester resin (A) from the viewpoint of moldability. 5 mol% or less.

  In addition, the aliphatic polyester mainly composed of diol and dicarboxylic acid may have a chain length extended by a coupling agent or the like.

  Examples of the coupling agent include diisocyanate, oxazoline, diepoxy compound, acid anhydride and the like. Specific examples include 2,4-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and the like. These addition amounts are preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the aliphatic polyester resin (A).

  Aliphatic polyesters mainly composed of diol and dicarboxylic acid are produced by known methods (methods described in JP 2012-144744 A, JP 2010-195989 A, JP 2009-173884 A, etc.). be able to. For example, a general method of melt polymerization in which an esterification reaction and / or transesterification reaction between the aliphatic dicarboxylic acid and the aliphatic diol is performed, and then a polycondensation reaction under reduced pressure is performed, or an organic solvent is used. Although it can manufacture also by the well-known solution heating dehydration condensation method used, the method of manufacturing by the melt polymerization performed without a solvent from a viewpoint of economical efficiency or the simplicity of a manufacturing process is preferable. For example, a general method of melt polymerization in which an esterification reaction and / or transesterification reaction between the aliphatic dicarboxylic acid and the aliphatic diol is performed, and then a polycondensation reaction under reduced pressure is performed, or an organic solvent is used. Although it can manufacture also by the well-known solution heating dehydration condensation method used, the method of manufacturing by the melt polymerization performed without a solvent from a viewpoint of economical efficiency or the simplicity of a manufacturing process is preferable.

  Examples of usable products (commercially available products) include polybutylene succinate resin GS Pla (registered trademark) manufactured by Mitsubishi Chemical (polybutylene succinate, polybutylene succinate adipate, etc.), polybutylene succinate resin violore manufactured by Showa Denko KK (Registered trademark) and the like.

In the present invention, the aliphatic polyester having diol and dicarboxylic acid as main components preferably has the following physical properties.
The lower limit of the weight average molecular weight is preferably 10,000 or more, more preferably 20,000 or more, further preferably 50,000 or more, and the upper limit is preferably 1,000,000 or less, more preferably 500,000 or less. More preferably, it is 400,000 or less. By setting the weight average molecular weight within the above range, it is advantageous in terms of moldability and mechanical strength. In the present specification, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

  When measured at 190 ° C. and 2.16 kg, the lower limit of the melt flow rate (MFR) is preferably 0.1 g / 10 min or more, and the upper limit is preferably 100 g / 10 min or less, more preferably 50 g / 10 min. Hereinafter, it is particularly preferably 30 g / 10 min or less. By setting the melt flow rate within the above range, moldability and mechanical strength are improved.

  The lower limit of the melting point is preferably 70 ° C. or higher, more preferably 75 ° C. or higher, and the upper limit is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and particularly preferably 150 ° C. or lower. When there are a plurality of melting points, at least one melting point is preferably within the above range.

  The intrinsic viscosity (IV) is usually 0.6 or more, preferably 0.8 or more, more preferably 1.0 or more, and the upper limit is usually 1.8 or less, preferably 1.6 or less, more preferably 1. 4 or less. If the intrinsic viscosity is too small, the mechanical properties of the molded product may be reduced, and if the intrinsic viscosity is too large, the melt viscosity becomes too high during the molding process and the load on the extruder increases, which may reduce productivity. There is sex. In addition, in this specification, intrinsic viscosity (IV) is based on the value measured at 30 degreeC using the mixed solvent of phenol / tetrachloroethane (mass ratio 1/1).

  In the present invention, the physical properties of the aliphatic polyester resin (A) are substantially the same as described above.

  The content of the aliphatic polyester mainly composed of diol and dicarboxylic acid in the aliphatic polyester resin (A) is 50 parts by mass or more when the total aliphatic polyester resin (A) is 100 parts by mass. , Preferably it is 70 mass parts or more, More preferably, it is 90 mass parts or more, and an upper limit is 100 mass parts or less. When the content is within the above range, moderate biodegradability is possible particularly when used in applications that require rapid degradation after use as described above.

1.2. Aliphatic polyester mainly composed of oxycarboxylic acid The aliphatic polyester mainly composed of oxycarboxylic acid is an aliphatic polyester comprising at least one aliphatic oxycarboxylic acid unit.

  Specific examples of the aliphatic oxycarboxylic acid that gives an aliphatic oxycarboxylic acid unit include, for example, lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, 3-hydroxyvaleric acid, malic acid, citric acid, etc., or lower Examples thereof include alkyl esters and intramolecular esters. In addition, lactone compounds such as ε-caprolactone are also included in the aliphatic oxycarboxylic acid in the present invention. When optical isomers exist in these, any of D-form, L-form and racemic form may be sufficient, and the form may be solid, liquid, or aqueous solution. Among these, lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 6-hydroxycaproic acid, and 3-hydroxyvaleric acid are preferable. One of these aliphatic oxycarboxylic acids may be used alone, or two or more thereof may be used in any ratio and combination.

  Specific examples of the aliphatic polyester mainly composed of oxycarboxylic acid include polylactic acid, polyglycolic acid, poly-3-hydroxybutyrate, poly-4-hydroxybutyrate, poly (3-hydroxybutyrate-co-3- Hydroxyvalerate), polycaprolactone and the like. Of these, polylactic acid is particularly preferred.

  The constitution of polylactic acid contained in the polylactic acid resin is preferably D-lactic acid: L-lactic acid = 100: 0 to 85:15 or 0: 100 to 15:85 as a molar ratio. It is also possible to blend other polylactic acids having different constituent ratios of D-lactic acid and L-lactic acid. A polylactic acid resin having only D-lactic acid or L-lactic acid as a structural unit becomes a crystalline resin, has a high melting point, and tends to have excellent heat resistance and mechanical properties.

  Furthermore, the polylactic acid resin may be a copolymer of the above-described polylactic acid and other hydroxycarboxylic acid units, and may contain a small amount of a chain extender residue. As other hydroxycarboxylic acid units, optical isomers of lactic acid (D-lactic acid for L-lactic acid, L-lactic acid for D-lactic acid), glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid Bifunctional aliphatic hydroxycarboxylic acids such as 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, and the like, and Examples include lactones such as caprolactone, butyrolactone, and valerolactone. Such other hydroxycarboxylic acid units are preferably used in less than 15 mol% in the polylactic acid resin.

  Examples of the chain extender residue that may be contained in the resin include a residue derived from the above-described coupling agent.

  Aliphatic polyesters mainly composed of oxycarboxylic acid, such as polylactic acid resin, are prepared by known methods such as condensation polymerization and ring-opening polymerization (JP-A-9-151244, JP-A-8-12750, international publication). No. 00/078839, etc.). For example, in the condensation polymerization method, a polylactic acid resin having an arbitrary composition and crystallinity can be obtained by directly dehydrating condensation polymerization of L-lactic acid, D-lactic acid, or a mixture thereof. Further, in the ring-opening polymerization method (lactide method), a lactate which is a cyclic dimer of lactic acid can be used to obtain a polylactic acid resin using an appropriate catalyst while using a polymerization regulator or the like as necessary. it can. The lactide includes L-lactide which is a dimer of L-lactic acid, D-lactide which is a dimer of D-lactic acid, DL-lactide which is a dimer of D-lactic acid and L-lactic acid. These are mixed as necessary and polymerized to obtain a polylactic acid resin having an arbitrary composition and crystallinity.

  Examples of usable products (commercial products) include polylactic acid resin Ingeo (registered trademark) manufactured by Nature Works.

  The lower limit of the weight average molecular weight of the polylactic acid resin that can be used in the present invention is preferably 60,000 or more, more preferably 80,000 or more, particularly preferably 100,000 or more, and the upper limit is preferably 700,000 or less. , More preferably 400,000 or less, particularly preferably 300,000 or less. When the weight average molecular weight is less than 60,000, practical physical properties such as mechanical properties and heat resistance are inferior, and when it is more than 700,000, the melt viscosity tends to be too high and the molding processability tends to be inferior.

  The content of the aliphatic polyester mainly composed of oxycarboxylic acid in the aliphatic polyester resin (A) is preferably 1 part by mass when the total amount of the aliphatic polyester resin (A) is 100 parts by mass. Above, more preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, and the upper limit is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less. By making content into the said range, hydrolyzability may improve.

1.3. Aliphatic aromatic polyester mainly composed of diol and dicarboxylic acid An aliphatic aromatic polyester mainly composed of diol and dicarboxylic acid (hereinafter sometimes referred to as “aliphatic aromatic polyester”) has the following formula ( An essential component is an aliphatic diol unit represented by 3), an aliphatic dicarboxylic acid unit represented by the following formula (4), and an aromatic dicarboxylic acid unit represented by the following formula (5). It is. However, it may have an oxycarboxylic acid unit.

—O—R ³¹ —O— (3)
[In the formula (3), R ³¹ represents a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group which may have an oxygen atom in the chain, and is a copolymer If it is, it is not limited to one type. ]

—OC—R ⁴¹ —CO— (4)
[In the formula (4), R ⁴¹ represents a direct bond or a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, and is copolymerized. It is not limited to one type. ]

—OC—R ⁵¹ —CO— (5)
[In Formula (5), R ⁵¹ represents a divalent aromatic hydrocarbon group, and is not limited to one type when copolymerized. ]

  Although it does not specifically limit as aliphatic diol which gives the diol unit of Formula (3), From a viewpoint of a moldability or mechanical strength, a C2-C10 aliphatic diol is preferable and a C4-C6 aliphatic diol. Is particularly preferred. Specifically, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptane Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,2-cyclohexanediol, 1, Examples include 4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 1,4-butanediol is particularly preferable. The above aliphatic diols may be used alone or in combination of two or more in any ratio and combination.

  Although it does not specifically limit as an aliphatic dicarboxylic acid component which gives the aliphatic dicarboxylic acid unit of Formula (4), A C2-C40 aliphatic dicarboxylic acid is preferable, A C4-C10 aliphatic dicarboxylic acid is especially preferable. preferable. Specific examples include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and dimer acid. Of these, succinic acid, adipic acid and sebacic acid are preferred, succinic acid and adipic acid are more preferred, and succinic acid is particularly preferred. The above aliphatic dicarboxylic acids may be used alone or in combination of two or more in any ratio and combination.

  Although it does not specifically limit as an aromatic dicarboxylic acid component which gives the aromatic dicarboxylic acid unit of Formula (5), A terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, etc. are mentioned. These may be acid anhydrides. Examples of the aromatic dicarboxylic acid derivatives include lower alkyl esters of these aromatic dicarboxylic acids. Among these, terephthalic acid, isophthalic acid, or their lower alkyl (e.g., alkyl having 1 to 4 carbon atoms) ester derivatives are preferable, and in particular, terephthalic acid and / or methyl ester of terephthalic acid, terephthalic acid and / or terephthalic acid. A mixture containing a methyl ester of an acid and isophthalic acid and / or a methyl ester of isophthalic acid is preferred. These may be used individually by 1 type, and may mix and use 2 or more types.

  As specific examples of the aliphatic aromatic polyester, polybutylene terephthalate alkylate is preferable, polybutylene adipate terephthalate or polybutylene succinate terephthalate is more preferable, and polybutylene adipate terephthalate is particularly preferable.

  The aliphatic aromatic polyester can be produced by a known method (a method described in JP 2008-31457 A, JP 2008-31456 A, JP 2001-26643 A, or the like). For example, a general method of melt polymerization in which after the esterification reaction and / or transesterification reaction of the above aliphatic dicarboxylic acid, aromatic dicarboxylic acid and aliphatic diol, a polycondensation reaction is performed under reduced pressure Alternatively, it can also be produced by a known solution heating dehydration condensation method using an organic solvent, but from the viewpoint of economy and simplicity of the production process, a method of production by melt polymerization carried out in the absence of a solvent is preferred.

  Examples of usable products (commercially available products) include polybutylene terephthalate adipate resin ECOFLEX (registered trademark) manufactured by BASF.

  The content of the aliphatic aromatic polyester in the aliphatic polyester resin (A) is preferably 100 parts by mass or less, more preferably 50, when the entire aliphatic polyester resin (A) is 100 parts by mass. It is 30 parts by mass or less, particularly preferably 30 parts by mass or less.

2. Other resins In the present invention, in addition to the aliphatic polyester resin (A), other resins may be included as long as the effects of the present invention are not impaired. Examples of other resins include polyamide, polyvinyl alcohol, cellulose ester, and aromatic polyester.

  In the aliphatic polyester resin composition according to the present invention, the blending ratio of the aliphatic polyester resin (A) and the other resin may be such that the aliphatic polyester resin (A) is a main component in the resin component. Specifically, the total amount of the resin components contained in the resin composition is 100% by mass, and the aliphatic polyester resin (A) is 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more.

3. Organophosphorus compound (B)
In the present invention, an organic compound containing a carbon-phosphorus bond can be widely applied as the organic phosphorus compound (B). In particular, at least one organic phosphorus compound selected from organic phosphates, organic phosphites, and organic phosphonites is preferable. In the present invention, phosphates and phosphites may be bonded to each other to form diphosphates, diphosphites, and the like. The same applies to phosphonite.

  In the present invention, examples of the organic phosphate include a compound having a structure represented by the following formula (6). Here, the compounds of formula (6) may be combined to form diphosphate or the like.

[In Formula (6), R ³ , R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms which may have a substituent, R ³ , R ⁴ and R ⁵ may be bonded to each other to form a ring. ]

In the formula (6), examples of the alkyl group having 1 to 30 carbon atoms of R ^{3 to} R ⁵ include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, octadecyl, cyclohexyl, stearyl and the like. Can be mentioned. Examples of the aryl group having 6 to 30 carbon atoms include phenyl, nonylphenyl, butylphenyl, butylmethylphenyl, dibutylphenyl, dibutylmethylphenyl, biphenyl, octylphenyl, and the like. These aryl groups may have a substituent such as a methyl group, an ethyl group, an i-propyl group, or a t-butyl group.

  In the present invention, examples of the organic phosphite include compounds having a structure represented by the following formula (7). Here, the compounds of the formula (7) may be bonded to form diphosphite or the like.

Wherein ^{(7), R 6, R} 7, R 8 has the same meaning as ^{R 3,} R 4, ^{R 5} above. ]

Specifically, for example, tris- (2,4-di-t-butylphenyl) phosphite, tetrakis- (2,4-di-t-butylphenyl) -4,4′-biphenylene phosphite, bis- (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis- (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, distearyl-pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 4,4-butylidenebis (3-methyl-6-t-butylphenyl-di-tridecyl) phosphite, 1,1,3 -Tris- (2-methyl-4-tridecyl phosphite-5-t-butylphenyl) butane, tris- (nonylphenyl) phos Phyto and 4,4′-isopropylidenebis- (phenyl-dialkyl phosphite), 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10 -Tetra-t-butyldibenz [d, f] [1,3,2] dioxaphosphine and the like. Among them, tris- (2,4-di-t-butylphenyl) phosphite, bis- (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis- (2,6-di-t-butyl) -4-Methylphenyl) pentaerythritol diphosphite is preferred. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.

  Moreover, in this invention, as a preferable organic phosphorus compound (organic phosphate, organic phosphite), the compound represented by following formula (8) is mentioned, for example. Here, the compounds of the formula (8) may be bonded to form diphosphate, diphosphite, or the like.

[In formula (8), X shows a hydrogen atom or OH, n shows the integer of 1-20, m shows 1 or 2. ]

  In the above formula (8), X is preferably OH, n is preferably an integer of 2 to 18, more preferably an integer of 4 to 13, and an integer of 6 to 10 is more preferable.

  Further, m is 1 or 2, but the compound represented by the formula (8) does not have to be a single compound consisting of m = 1 and m = 2, and a compound having m = 1 and m = 2. It may be a mixture of The mixing ratio is not particularly limited, and may be a mixing ratio that inevitably occurs depending on manufacturing conditions and the like. That is, in Formula (8), m is 1 or 2, but it is not necessary to be only one of them.

Examples of the group C _n H _{2n + 1} include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, an isooctyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, and an isodecyl group. , Lauryl group, tridecyl group, oleyl group, stearyl group and the like. Of these, a 2-ethylhexyl group is preferred.

  Examples of the compound represented by the formula (8) include 2-ethylhexyl acid phosphate, bis (2-ethylhexyl) hydrogen phosphite, ethyl acid phosphate, butyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, diethyl hydrogen Examples thereof include phosphite, bis (2-ethylhexyl) hydrogen phosphite, dilauryl hydrogen phosphite, and dioleyl hydrogen phosphite. Among these, 2-ethylhexyl acid phosphate, bis (2-ethylhexyl) hydrogen phosphite, isotridecyl acid phosphate, dilauryl hydrogen phosphite are preferable, and 2-ethylhexyl acid phosphate, bis (2-ethylhexyl) hydrogen phosphite. Is more preferable. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.

  In the present invention, as the organic phosphonite, for example, a compound having a structure represented by the following formula (9) can be used. Here, the compounds of the formula (9) may be bonded to form diphosphonite or the like.

[In Formula (9), R < ⁹ >, R < ¹⁰ >, R < ¹¹ > is synonymous with said R < ³ >, R < ⁴ >, R < ⁵ >. ]

Specifically, for example, tetrakis (di-t-butylphenyl) -biphenylenediphosphonite, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbis Examples thereof include phosphonite, tetrakis- (2,4-di-t-butyl-5-methylphenyl) -1,1-biphenyl-4,4′-diylbisphosphonite. Of these, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite is preferred. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.

4). Sulfonic acid ester compound (C)
In the present invention, the sulfonic acid ester (C) is not particularly limited, and examples thereof include a sulfonic acid compound and an alcohol, or a sulfonic acid ester composed of a sulfonic acid compound and phenol.

  Examples of the sulfonic acid compound include aliphatic sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, and butanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalene-α-sulfonic acid, naphthalene-β-sulfonic acid, and the like. Of the aromatic sulfonic acid.

  Examples of the alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, t-butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, and undecyl alcohol. , Lauryl alcohol, stearyl alcohol and the like.

  An aromatic sulfonic acid ester composed of an aromatic sulfonic acid and an alcohol is preferred from the viewpoint of the balance between the decomposability of the aliphatic polyester resin composition by blending and the difficulty of volatilization of the sulfonic acid ester. Methyl acid, ethyl p-toluenesulfonate, and butyl p-toluenesulfonate are preferable, and methyl p-toluenesulfonate is particularly preferable. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.

  In the polyester resin composition according to the present invention, the content (total amount) of the organic phosphorus compound (B) and / or the sulfonic acid ester compound (C) (hereinafter sometimes referred to as “hydrolysis accelerator”) is as follows. The lower limit is usually 0.1 parts by mass or more, preferably 0.6 parts by mass or more, more preferably 1 part by mass or more, further preferably 1.5 parts by mass with respect to 100 parts by mass of the aliphatic polyester resin (A). The upper limit is usually 5 parts by mass or less, preferably 4 parts by mass or less, more preferably 3.5 parts by mass or less, and further preferably 3 parts by mass or less. By adding the hydrolysis accelerator to the above-mentioned aliphatic polyester resin (A) so as to have the above-mentioned content and melt-kneading, it has a sufficient molecular weight at the time of production, under high humidity conditions such as in soil and water Thus, it is possible to obtain an aliphatic polyester resin composition having the characteristics of causing the molecular weight to rapidly decrease even under mild temperature conditions.

5. Other components The resin composition according to the present invention includes lubricants, fillers (fillers), plasticizers, antistatic agents, antioxidants, light stabilizers, ultraviolet absorbers, dyes, pigments, hydrolysis inhibitors, and the like. Various additives, animal / plant substance fine powders such as starch, cellulose, paper, wood powder, chitin / chitosan, coconut shell powder, walnut shell powder, or mixtures thereof are included as “other ingredients”. Also good. These can be arbitrarily used as long as the effects of the present invention are not impaired. These may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations. The additive amount of these additives is usually such that the total amount of compounds to be mixed is 0.01% by mass or more and 40% by mass or less with respect to the total amount of the resin composition so as not to impair the physical properties of the resin composition. Is preferred.

5.1. Lubricant When the resin composition according to the present invention contains a lubricant, the moldability of the resin composition can be improved.

  Examples of the lubricant include paraffins such as paraffin oil and solid paraffin; higher fatty acids such as stearic acid and palmitic acid; higher alcohols such as palmityl alcohol and stearyl alcohol; calcium stearate, zinc stearate, barium stearate, aluminum stearate , Metal salts of fatty acids such as magnesium stearate and sodium palmitate; fatty acid esters such as butyl stearate, glycerin monostearate, diethylene glycol monostearate; stearamide, methylenebisstearamide, ethylenebisstearamide, oxystearic acid Fatty acid amides such as ethylenediamide, methylolamide, oleylamide, stearic acid amide, erucic acid amide; carnauba wax, montan wax, etc. Such as box acids and the like. Of these, erucic acid amide is particularly preferred. In addition, lubricants and waxes may be used alone or in combination of two or more in any ratio and combination. The content of these lubricants is usually in the range of 0.01 to 2% by mass and preferably in the range of 0.05 to 0.5% by mass in the resin composition.

5.2. Filler When the resin composition according to the present invention contains a filler, the rigidity of the resin composition can be improved. Moreover, when a resin composition is used as a film, blocking between films can be prevented. Alternatively, when the film is formed into a bag, the opening of the bag can be easily opened. Furthermore, the film and the bag can be colored to improve the light shielding property and the light reflecting property.

  Depending on the shape of the filler, there are fibrous, powdery, and plate-like fillers, and powdery and plate-like fillers are particularly preferable. Examples of the particulate filler include mineral particles such as talc, zeolite, diatomaceous earth, kaolin, clay, silica, and quartz powder, metal carbonate particles such as calcium carbonate, magnesium carbonate, and heavy calcium carbonate, calcium silicate, and aluminum silicate. , Metal silicate particles such as magnesium silicate, metal oxide particles such as alumina, silica, zinc oxide and titanium oxide, metal hydroxide particles such as aluminum hydroxide, calcium hydroxide and magnesium hydroxide, carbon such as carbon black Particles and the like. Moreover, as a plate-shaped filler, mica is mentioned, for example. From the viewpoint of facilitating the opening of the bag and preventing blocking, talc, calcium carbonate, or silica is preferably used. From the viewpoint of coloring the film or bag and improving the light shielding property or light reflecting property. Carbon black or titanium oxide may be used. The dispersion state of the filler in a molded body such as a film or the resin composition is 0.08 to 25 μm, more preferably 0.1 to 5 μm, in terms of number average particle diameter. When it deviates from this range, the addition effect of the said filler will become low. A filler may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations. These fillers are usually used in the resin composition in the range of 0.05 to 40% by mass.

5.3. Plasticizer In addition, when the flowability of a resin composition is bad, it is good to add a plasticizer. In particular, when a filler is included in the resin composition, the viscosity of the resin composition may increase and the flowability of the resin composition may deteriorate, and this may be reduced by adding a plasticizer to the resin composition. Can be improved.

  Examples of the plasticizer include methyl adipate, diethyl adipate, diisopropyl adipate, di-n-propyl adipate, di-2-ethylhexyl adipate, diisobutyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol adipate, di-2-ethylhexylase Fatty acid esters such as rate, dibutyl sebacate, di-2-ethylhexyl sebacate, methylacetyl lysylate; glycerin esters such as triacetin; diethyl maleate, dibutyl maleate, dioctyl maleate, dibutyl fumarate, dioctyl fumarate, etc. Maleic acid and fumaric acid ester; polyester / epoxidized ester such as adipic acid-1,3-butylene glycol and epoxidized soybean oil; trioctyl Trimellitic acid esters such as melitrate; triethylene glycol diacetate, tributyl acetyl citrate, glycerol diacetomonopropionate, glycerol diacetomonocaprylate, glycerol diacetomonocaprate, glycerol diacetomonolaurate, glycerol diacetomonooleate, glycerol Acetylated monoglycerides such as monoacetomonobehenate and glycerin monoacetomonostearate; polyglycerides such as diglycerin acetate, decaglycerin propionate, tetraglycerin caprylate, decaglycerin laurate, decaglycerin oleate, decaglycerin behenate Examples include glycerin fatty acid esters; rosin derivatives and the like. These plasticizers may be used alone or in combination of two or more in any ratio and combination. The plasticizer is preferably used in the resin composition in the range of 0.05 to 10% by mass.

5.4. Antistatic agent The resin composition according to the present invention may also contain an antistatic agent. Any antistatic agent can be used as long as the effects of the present invention are not significantly impaired. As a specific example, a surfactant type nonionic, cationic or anionic type is preferable.

  Nonionic antistatic agents include, for example, glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, alkyl diethanolamine, hydroxyalkyl monoethanolamine, polyoxyethylene alkylamine, polyoxyethylene alkylamine fatty acid ester Examples thereof include alkyl diethanol amides. Of these, alkyldiethanolamines are preferred.

  Examples of the cationic antistatic agent include tetraalkylammonium salts and trialkylbenzylammonium salts.

  Examples of the anionic antistatic agent include alkyl sulfonates, alkyl benzene sulfonates, and alkyl phosphates. Of these, alkylbenzene sulfonate is preferable. This is because the kneadability with the resin is good and the antistatic effect is high.

  The amount of the antistatic agent used is arbitrary as long as the effects of the present invention are not significantly impaired. However, the lower limit of the resin composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and the upper limit. Is preferably 5% by mass or less, more preferably 3% by mass or less. When the above range is exceeded, the resin composition has surface stickiness and the product value tends to decrease. On the other hand, if it is below the above range, the effect of improving the antistatic property tends to be reduced.

5.5. Other Additives In addition to the additives described above, the resin composition according to the present invention may contain starch, a light resistance agent, an ultraviolet absorber, a heat stabilizer, a terminal blocking agent, and the like.

  Specific examples of starch include corn starch, waxy corn starch, high amylose corn starch, wheat starch, rice starch, potato starch, sweet potato starch, tapioca starch, pea starch, etc., both of which are unmodified and modified products. it can. Modification includes all modification methods such as chemical, physical, and biological, and chemical modification includes esterification, etherification, oxidation, reduction, or partial or all of the structural units of carbohydrates (polysaccharides). It shows that it is modified by a chemical reaction such as coupling, dehydration, hydrolysis, dehydrogenation, halogenation, etc., and particularly shows that a hydroxyl group is etherified or esterified. Physical modification means changing physical properties such as changing the crystallinity. Biological degeneration refers to changing a chemical structure or the like using a living organism.

  Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester decanoate, a reaction product of 1,1-dimethylethyl hydroperoxide and octane, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (1,2 , 2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) ) Sebacate, 1- [2- [3- [3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-ter -Butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5- Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] and the like Hindered amine stabilizers and the like. The light stabilizer is preferably used in combination with an ultraviolet absorber, and a combination of a hindered amine stabilizer and an ultraviolet absorber is effective.

  The amount of the light proofing agent to be mixed is, on the mass basis, preferably 100 ppm or more, more preferably 200 ppm or more, and the upper limit is preferably 5% or less, more preferably 1% or less, based on the resin composition. Preferably it is 0.5% or less. Below this range, the effect of the light resisting agent tends to be small. Moreover, when it exceeds this range, the manufacturing cost tends to increase, and the heat resistance of the resin composition tends to be inferior, or the light-proofing agent tends to bleed out.

  Examples of the ultraviolet absorber include 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol, 2- (4,6-diphenyl-1,3). , 5-triazin-2-yl) -5-[(hexyl) oxy] phenol and the like. It is preferable to use two or more different kinds of ultraviolet absorbers in any ratio and combination.

  The amount of the ultraviolet absorber to be mixed is arbitrary as long as the effects of the present invention are not significantly impaired. However, the lower limit of the resin composition is preferably 100 ppm or more, more preferably 200 ppm or more, and the upper limit. Is preferably 5% or less, more preferably 2% or less, and still more preferably 0.5% or less. Below this range, the effect of the ultraviolet absorber tends to decrease. Moreover, when it exceeds this range, the production cost tends to be too high, the heat resistance of the resin composition is inferior, or the ultraviolet absorber bleeds out.

  Examples of the heat stabilizer include dibutylhydroxytoluene (BHT; 2,6-di-tert-butyl-4-methylphenol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), pentaerythritol. Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-tris [ (4-tert-Butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3 5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, calcium diethylbis [[3 5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, bis (2,2′-dihydroxy-3,3′-di-tert-butyl-5,5′-dimethylphenyl) ethane Hindered phenol heat stabilizers such as N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide; 3-hydroxy-5,7 -Lactone heat stabilizers such as di-tert-butyl-furan-2-one and xylene reactive organisms; dilauryl thiodipropionate, distearyl thiodipropionate Sulfur-based antioxidants and the like can be mentioned. Alternatively, the organic phosphorus compounds described above, may be also functions as a phosphorus-based heat stabilizer.

  The amount of the heat stabilizer to be mixed is based on the mass of the resin composition, and the lower limit is preferably 100 ppm or more, more preferably 200 ppm or more, and the upper limit is preferably 5% or less, more preferably 1% or less. More preferably, it is 0.5% or less. Below this range, the effect of the heat stabilizer tends to be small. On the other hand, if it exceeds this range, the manufacturing cost tends to be high, and the bleedout of the thermal stabilizer may occur.

  The end-capping agent is mainly used for the purpose of suppressing hydrolysis due to moisture in the atmosphere, and examples thereof include carbodiimide compounds, epoxy compounds, and oxazoline compounds. Among the above carbodiimide compounds, examples of the monocarbodiimide compound include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β- Naphthyl carbodiimide etc. are mentioned. Of these, dicyclohexylcarbodiimide and diisopropylcarbodiimide are preferred because they are easily available industrially.

  Examples of the polycarbodiimide compound include U.S. Pat. No. 2,941,956, Japanese Patent Publication No. 47-33279, J. Pat. Org. Chem. 28, p2069-2075 (1963), Chemical Review 1981, 81, No. 4, p. What was manufactured by the method described in 619-621 grade | etc., Can be used.

  These carbodiimide compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations. In the present invention, it is particularly preferable to use a polycarbodiimide compound, and the degree of polymerization of the lower limit is usually 2 or more, preferably 4 or more, and the upper limit is usually 40 or less, preferably 20 or less. The amount of these carbodiimides is usually 0.1 to 5% by mass with respect to the entire resin composition.

  In addition to these, known surface wettability improvers, flame retardants, mold release agents, incineration aids, pigments, dispersion aids, surfactants, hydrolysis inhibitors, crystal nucleating agents, compatibilizing agents and the like are included. Also good.

6). Production Method In the present invention, 0.1 to 5 parts by mass of an organophosphorus compound (B) and / or a sulfonic acid ester compound (C) is further added to 100 parts by mass of the aliphatic polyester resin (A) as necessary. An aliphatic polyester resin composition is produced by melt-kneading other components at a temperature of 90 to 185 ° C.

  Conventionally, various additives (for example, phosphorus-based antioxidants, heat stabilizers, etc.) have been mixed together with the raw materials during polymerization of the resin (internal polymerization). If it is too much, polymerization will be inhibited. Moreover, the molecular weight of the resin to be produced is lowered, which is not preferable as a polymer. On the other hand, in the present invention, after polymerizing the polymer in advance, the polymer (aliphatic polyester resin (A)) and the organic phosphorus compound and / or sulfonic acid ester compound (hydrolysis accelerator) are subjected to a specific temperature. It is characterized by melt-kneading in this process, so that it has a sufficient molecular weight at the time of manufacture, excellent mechanical properties, and since these compounds were added in a larger amount than before, It is possible to obtain a resin composition that exhibits an unprecedented remarkable effect that molecular weight is rapidly reduced under humid conditions such as in water.

  The lower limit of the kneading temperature is 90 ° C or higher, preferably 120 ° C or higher, more preferably 130 ° C or higher, and the upper limit is 185 ° C or lower, preferably 170 ° C or lower, more preferably 150 ° C or lower. When the kneading temperature is less than 90, the melt viscosity becomes high and kneading may be difficult. On the other hand, when the kneading temperature exceeds 185 ° C., the melt viscosity of the aliphatic polyester resin composition becomes low, and it may be difficult to take up the strands.

  In addition, when melt-kneading the aliphatic polyester resin (A) and the hydrolysis accelerator, it is preferable that the water content in the aliphatic polyester resin (A) before kneading is within a predetermined range. That is, the upper limit of the amount of water before kneading in the aliphatic polyester resin (A) is preferably 2000 ppm or less, more preferably 1500 ppm or less. Thereby, the intrinsic viscosity retention with respect to the aliphatic polyester resin (A) of the aliphatic polyester resin composition obtained by melt-kneading the aliphatic polyester resin (A) and the phosphonite compound (B) is maintained at 60% or more. It becomes easier.

  In the production of the resin composition, all conventionally known mixing / kneading techniques can be applied. As the mixer, a horizontal cylindrical type, V-shaped, double-cone type mixer, a blender such as a ribbon blender or a super mixer, various continuous mixers, or the like can be used. As the kneader, a batch kneader such as a roll or an internal mixer, a single-stage or two-stage continuous kneader, a twin screw extruder, a single screw extruder, or the like can be used. In this invention, it is preferable to use a twin screw extruder from the point of kneading | mixing efficiency, and also the thing whose rotation direction of a screw is the same direction is preferable.

  Specific examples of the production method include a method in which the aliphatic polyester resin (A), the hydrolysis accelerator, and other components as necessary are blended and then melt mixed in the same extruder. Alternatively, when the aliphatic polyester resin (A) and the hydrolysis accelerator are mixed and heated and melted, other components can be added and blended as necessary. At this time, blending oil or the like can be used for the purpose of uniformly dispersing the respective components.

A single screw or twin screw extruder can be used as the resin extruder. In particular, it is preferable to use a resin extruder equipped with a vacuum vent and perform melt kneading while reducing the pressure inside the extruder with the vacuum vent. The internal pressure of the extruder during decompression is preferably about 5 to 50 kPa. By reducing the pressure in the system at the time of melt-kneading, moisture can be removed from the resin composition, and a resin composition having further excellent mechanical properties and the like can be obtained.
However, when the decomposition accelerator is likely to volatilize, it may be preferable to perform melt kneading while maintaining the normal pressure without reducing the pressure.

  The lower limit of the screw rotation speed of the extruder is usually 150 rpm or more, preferably 200 rpm or more, more preferably 250 rpm or more, and the upper eye is usually 400 rpm or less, preferably 350 rpm or less, more preferably 300 rpm or less. If the lower limit is less than 150 rpm, the dispersibility of the decomposition accelerator may be low, and the subsequent hydrolyzability variation may increase. If the upper limit exceeds 400 rpm, shear heat generation will increase, and the aliphatic polyester resin composition. May break down.

7). Properties of Aliphatic Polyester Resin Composition The aliphatic polyester resin composition according to the present invention preferably has an intrinsic viscosity (IV) of 0.6 to 1.8. The intrinsic viscosity is more preferably 0.8 or more, further preferably 1.0 or more, more preferably 1.6 or less, and further preferably 1.4 or less. If the intrinsic viscosity is too small, the mechanical properties of the molded product may be lowered. If the intrinsic viscosity is too large, the melt viscosity becomes too high during molding and the moldability may be lowered.

  In the aliphatic polyester resin composition according to the present invention, the intrinsic viscosity retention with respect to the aliphatic polyester resin (A) as a raw material is more preferably 80% or more and 100% or less, and 90% or more and 100% or less. More preferably. If the intrinsic viscosity retention is 60% or more, there is no particular problem, but if it is less than 60%, many low molecular weight components derived from the aliphatic polyester resin composition are produced. Trouble may occur.

  In addition, the aliphatic polyester resin composition according to the present invention contains the hydrolysis accelerator in the aliphatic polyester resin as described above, so that the intrinsic viscosity retention after water immersion is within a predetermined preferable range. That is, the aliphatic polyester resin composition according to the present invention preferably has an intrinsic viscosity retention of 20% or less after being immersed in water at 60 ° C. for 13 days. The intrinsic viscosity retention is more preferably 18% or less, and still more preferably 15% or less. Thereby, since molecular weight falls rapidly, it can be used conveniently for the use as which quick decomposition | disassembly is calculated | required.

8). Molded Article and Use The method for obtaining a molded article from the resin composition according to the present invention is not particularly limited, and various molding methods employed for thermoplastic resins can be applied, and the obtained molded article For example, molded products by injection molding methods such as injection molding, injection blow molding, injection compression molding, foam molding, etc .; pipes and tubes, deformed products, electric wires by extrusion molding methods such as T-die method, inflation method, laminating Molded products such as coatings, multilayer or single layer films / sheets, monofilaments, multifilaments, core-sheath structured fibers; molded products by blow molding, molded products by vacuum molding, molded products by calendar molding, and compression molding Examples thereof include molded products and molded products such as powders or granules obtained by a pulverization method.

  In the present invention, the resin composition according to the present invention is molded into a molded product by directly performing melt-kneading of the aliphatic polyester resin (A) and the hydrolysis accelerator with a molding machine used in the molding method described above. Can also be manufactured directly.

  The resin composition according to the present invention has a good mechanical strength in the initial stage of use, and rapidly causes a decrease in molecular weight under high humidity conditions such as in soil and water. In order to effectively use the characteristics, the resin composition according to the present invention is preferably formed into a film, a container, or the like used for soil improvement, agriculture, crude oil excavation, or the like. When forming into a film, it is also possible to set it as the laminated | multilayer film which laminated | stacked several types of compositions in the range which does not impair the effect of this invention. When the resin composition according to the present invention is formed into a film, the film may be uniaxially or biaxially stretched by a roll method, a tenter method, a tubular method, or the like. When extending | stretching, extending | stretching temperature is normally in the range of 30 to 110 degreeC, and a draw ratio is performed in the range of 0.6 to 10 times in the vertical and horizontal directions, respectively. Further, after stretching, heat treatment may be performed by a method of blowing hot air, a method of irradiating infrared rays, a method of irradiating microwaves, a method of contacting on a heat roll, or the like.

  The resin composition according to the present invention, as specifically shown in the examples described later, has sufficient mechanical strength in the initial stage of use, and a low temperature (mild temperature) of 100 ° C. or less under humid conditions. Controlled degradation characteristics, that is, rapid molecular weight reduction, and when used as a sealant for voids when mining underground resources such as crude oil and gas, for example, shale gas Since it is considered that it disappears after performing the function and does not cause a reduction in the subsequent gas recovery efficiency, it is particularly expected to be applied as a sealing material in underground resource mining.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, the following examples are shown in order to explain the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the gist thereof. In addition, various production conditions and evaluation result values in the following examples have meanings as preferred values of the upper limit or the lower limit in the embodiment of the present invention, and the preferred range is the value of the upper limit or the lower limit. It may be a range defined by a combination of values of the examples or values between the examples.

<Evaluation methods and materials>
(1) Underwater decomposition (hydrolysis) test 5.0 g of aliphatic polyester resin composition and 15.0 g of deionized water were placed in a glass bottle, capped, and then placed in an oven at 60 ° C for 13 days. Then, the resin composition was taken out from the glass bottle and dried at 70 ° C. for 6 hours under a nitrogen flow. The obtained resin composition is subjected to mass measurement and intrinsic viscosity measurement, and the ratio between the mass before measurement and the intrinsic viscosity is calculated, and the mass retention rate and intrinsic viscosity retention rate in the underwater decomposition test are calculated. did.

(2) Mass measurement Mass measurement was performed using a digital balance A200S manufactured by sartorius (weighable to 0.0001 g).

(3) Intrinsic viscosity measurement (IV measurement)
It calculated | required in the following way using the Ubbelohde type viscometer. That is, a mixed solvent of phenol / tetrachloroethane (mass ratio 1/1) was used, and at 30 ° C., the polyester sample solution having a concentration of 0.5 g / dL and the falling seconds of the solvent alone were measured, and the following formula (A )
IV = ((1 + 4KHη _sp ) ^0.5 −1) / (2KHC) (A)
Here, η _sp = η / η ₀ −1, η is the sample solution dropping time, η ₀ is the solvent dropping time, C is the sample solution concentration (g / dL), and KH is the Huggins constant. It is. KH adopted 0.33.

(4) Odor at the time of melt kneading It was judged that the odor at the time of melt kneading had a lot of odor around the die of the extruder.

(5) Smoke generation during melt-kneading The smoke generation during melt-kneading was visually confirmed around the die of the extruder to determine whether there was much or less smoke.

(6) Whether or not strands can be taken out during melt kneading Whether or not strands can be taken out during melt kneading was determined by strand take-up work.

(7) Resin The resin used is as follows.
(PBS-1) Polybutylene succinate manufactured by Mitsubishi Chemical Corporation FZ61PN, IV = 1.228
(PBS-2) Polybutylene succinate FZ71PN, IV = 1.427 manufactured by Mitsubishi Chemical Corporation
(PBSA) manufactured by Mitsubishi Chemical Co., Ltd. Polybutylene succinate adipate FD92WN, IV = 1.752
(PLA) Polylactic acid 6302D, IV = 1.383 manufactured by Nature Works

(8) Hydrolysis accelerator The additives used as the hydrolysis accelerator are as follows.
<2-ethylhexyl acid phosphate> JP-508 manufactured by Johoku Chemical Industry Co., Ltd.
<Bis (2-ethylhexyl) hydrogen phosphite> JPE-208 manufactured by Johoku Chemical Industry Co., Ltd.
<Butyl p-toluenesulfonate> PTSB manufactured by MRC Unitech
<Ethyl p-toluenesulfonate> PTSE manufactured by MRC Unitech
<Methyl p-toluenesulfonate> PTSM manufactured by MRC Unitech
<Tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite> HOSTANOX P-EPQ (powder) manufactured by Clariant Japan

<Production and Evaluation of Aliphatic Polyester Resin Composition>
[Examples 1-15, Comparative Examples 1-8]
The resin and hydrolysis accelerator were melt kneaded in a twin screw extruder (TEX30; 15 cylinders, L / D = 52.5) manufactured by Nippon Steel Works having one vent port in the ratio shown in Table 1. Extruded into a strand form from the outlet of the shaft extruder, cooled and solidified with water, and then pelletized with a rotary cutter. The obtained pellets were dried for 6 hours at 70 ° C. under a nitrogen flow to obtain an aliphatic polyester resin composition. The set temperature at the time of kneading was the temperature described in Table 1, and the screw rotation speed was 300 rpm. Each resin was used for melt kneading immediately after opening the moisture-proof bag.

It is determined whether or not odor, smoke, and strands can be taken out during melt kneading, and the results are shown in Table 1.
The obtained aliphatic polyester resin composition was subjected to an underwater decomposition (hydrolysis) test, and the respective retention rates were calculated from the mass and intrinsic viscosity measured before and after the test. The results are shown in Table 1.

In addition, IV before kneading | mixing in Example 6 and Example 15 was computed from the following formula.
Before kneading IV = (IV of PBS-1) * 0.92 + (IV of PLA) * 0.08
On the other hand, IV before kneading in Example 11 and Comparative Example 7 was calculated from the following formula.
Before kneading IV = (IV of PBS-2) * 0.92 + (IV of PLA) * 0.08

In Examples 1 to 15, the odor and fuming during melting and kneading were all small, and the strands could be taken up without any particular problem.
In Examples 1 to 15, the intrinsic viscosity retention after kneading is 60% or more, and the intrinsic viscosity retention in an underwater decomposition (hydrolysis) test (at 60 ° C. after 13 days) is 20% or less. , When used as a sealing material for voids when mining underground resources such as crude oil and gas, for example, when shale gas is mined, it disappears after exhibiting a temporary sealing function (the time until disappearance varies depending on the temperature) It is considered that it does not cause a decrease in the subsequent gas recovery efficiency. Therefore, it is considered that the material shown in the present application can be used very favorably in the same application.

  The aliphatic polyester resin composition according to the present invention has sufficient mechanical strength at the time of production and in the initial stage of use, has degradation characteristics controlled under humid conditions such as soil and water, and has a molecular weight that is prompt. Cause a drop. Therefore, for film, sheet, fiber, particle, molded product, etc., for applications that require rapid degradation after use, such as agricultural applications, soil modification applications, and underground resource mining applications such as oil and gas. Can be widely used.

Claims (9)

  Melting and kneading 0.1 to 5 parts by mass of the organophosphorus compound (B) and / or the sulfonate compound (C) with respect to 100 parts by mass of the aliphatic polyester resin (A) at 90 to 185 ° C. A method for producing an aliphatic polyester resin composition.   The aliphatic polyester resin (A) contains an aliphatic polyester mainly composed of diol and dicarboxylic acid, and the content thereof is 50 to 100 when the entire aliphatic polyester resin (A) is 100 parts by mass. The manufacturing method according to claim 1, wherein the manufacturing method is part by mass.   The process according to claim 1 or 2, wherein the diol is 1,4-butanediol and the dicarboxylic acid is succinic acid. The method according to any one of claims 1 to 3, wherein the organophosphorus compound (B) is a compound represented by the following formula (8).

(8)
[In Formula (8), X shows a hydrogen atom or OH, n shows the integer of 1-20, m shows 1 or 2. ]   The manufacturing method according to any one of claims 1 to 4, wherein the aliphatic polyester resin (A) has an intrinsic viscosity (IV) of 0.6 to 1.8.   The aliphatic polyester resin (A) contains an aliphatic polyester containing oxycarboxylic acid as a main component, and the content is 1 to 50 parts by mass when the entire aliphatic polyester resin (A) is 100 parts by mass. The manufacturing method of any one of Claims 1-5 characterized by the above-mentioned.   The production method according to any one of claims 1 to 6, wherein the aliphatic polyester resin composition has an intrinsic viscosity (IV) of 0.6 to 1.8.   The manufacturing method according to any one of claims 1 to 7, wherein an intrinsic viscosity retention of the aliphatic polyester resin composition with respect to the aliphatic polyester resin (A) is 60 to 100%.   The manufacturing method according to any one of claims 1 to 8, wherein the aliphatic polyester resin composition is used for a filler for a void for underground resource mining.