JP2011127132A - Aliphatic polyester resin composition and molded product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition exhibiting decomposability in natural environments and being excellent in dynamic properties, particularly in tear strength and impact strength. <P>SOLUTION: The aliphatic polyester resin composition comprises: an aliphatic polyester resin (A) having a glass transition temperature of not higher than 0°C, and an MFR, as measured at 190°C under a 2.16 kg load, of not greater than 10 g/10 min; and an aliphatic oxycarboxylic acid resin (B) having a glass transition temperature of not lower than 30°C, and an MFR, as measured at 190°C under a 2.16 kg load, of not less than 1.2 times that of the aliphatic polyester resin (A) wherein the content of (B) is 1-50 pts.wt. based on 100 pts.wt. of (A). The aliphatic polyester resin (A) comprises an aliphatic and/or an alicyclic diol unit, and an aliphatic and/or an alicyclic dicarboxylic acid unit as essential ingredients. The aliphatic oxycarboxylic acid resin (B) comprises an aliphatic oxycarboxylic acid unit as an essential ingredient. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an aliphatic polyester resin composition capable of providing a molded article having degradability in a natural environment and having excellent mechanical properties, and a molded article formed by molding the aliphatic polyester resin composition. .

  Conventionally, paper, plastic films, aluminum foils, and the like have been used in a wide range of applications such as liquids and powders for various foods, medicines, miscellaneous goods, solid packaging materials, agricultural materials, and building materials. In particular, plastic films are excellent in strength, water resistance, moldability, transparency, cost, etc., and are used in many applications as bags and containers. Examples of plastics currently used for these applications include polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate. However, when the film made of the above plastic is not biodegraded or hydrolyzed in the natural environment, or the degradation rate is extremely slow, it remains in the soil when it is buried after use or is discarded. May damage the landscape. Moreover, even when incinerated, there are problems such as generating harmful gases and damaging the incinerator.

  Therefore, many studies have been conducted on biodegradable materials as means for solving the above problems. Representative examples of biodegradable materials include aliphatic polyester resins such as polylactic acid, polybutylene succinate, polybutylene succinate adipate, and aromatic-aliphatic copolymer polyester resins such as polybutylene adipate terephthalate. .

  Aliphatic polyester resins such as polybutylene succinate and polybutylene succinate adipate that have an aliphatic dichanrubonic acid unit and an aliphatic diol unit have a high crystallization rate and good moldability, but the tear strength of the film. May be insufficient.

  On the other hand, aliphatic oxycarboxylic acid resins such as polylactic acid are materials with very high rigidity and high strength, but the impact strength when filmed is weak and the moldability is good due to the slow crystallization speed. Absent.

  As a technique for solving these problems, Patent Document 1 discloses a resin composition comprising a biodegradable polymer containing an aromatic dicarboxylic acid as a structural unit and an aliphatic polyester, and a molded product obtained from the composition. Yes. However, even when such a composition is used, the tear strength and impact strength of the film still remain insufficient.

  Patent Document 2 discloses a composition of an aliphatic polyester resin having an aliphatic dicanthuronic acid unit and an aliphatic diol unit and polylactic acid as a resin composition having both moldability and strength. The polylactic acid used in Patent Document 2 has a large molecular weight, but according to the study of the present inventors, it has been found that the effect of improving the impact strength is low when polylactic acid having a large molecular weight is used. .

  Patent Document 3 discloses an aromatic-aliphatic copolyester resin having an aromatic dicarboxylic acid unit, an aliphatic dicarboxylic acid unit, and an aliphatic diol unit, such as polybutylene adipate terephthalate. In order to develop sufficient biodegradability, it is necessary that aliphatic units exist between the aromatic units, but such materials have a low crystallization rate and have a problem in moldability. There is. In addition, since the surface of the molded product is sticky, the opening characteristics of the inflation film are poor, but when an anti-blocking agent or the like is blended, an opaque feeling appears. In addition, this material is sufficiently flexible, but has a low tensile strength, resulting in a so-called waistless film.

JP 2003-1704 A JP-A-9-272789 Special table 2001-500907

  The present invention provides a polyester resin composition that is degradable in a natural environment and excellent in mechanical properties, particularly tear strength and impact strength, and a molded article formed by molding this aliphatic polyester resin composition. The purpose is to do.

  As a result of intensive studies on the combined use of an aliphatic polyester resin (A) excellent in crystallinity and moldability and an aliphatic oxycarboxylic acid resin (B), the present inventors have found that a low molecular weight ( It has been found that by containing B) at a predetermined ratio, an aliphatic polyester resin composition having both biodegradability and excellent mechanical properties can be obtained, and the present invention has been completed.

  That is, the gist of the present invention is that the following aliphatic polyester resin (A) having a glass transition temperature of 0 ° C. or less and 190 ° C. and an MFR measured at 2.16 kg load of 10 g / 10 min or less and a glass transition temperature of The following aliphatic oxycarboxylic acid resin (B) having an MFR measured at 30 ° C. or higher and 190 ° C. under a 2.16 kg load is 1.2 times or more the MFR of the aliphatic polyester resin (A). The aliphatic polyester-based resin composition comprising 1 to 50 parts by weight of (B) with respect to 100 parts by weight of (A).

[Aliphatic polyester resin (A)]
Aliphatic polyester resin [aliphatic oxycarboxylic acid resin (B)] having an aliphatic and / or alicyclic diol unit and an aliphatic and / or alicyclic dicarboxylic acid unit as essential components
Aliphatic oxycarboxylic acid resin having an aliphatic oxycarboxylic acid unit as an essential component

  In the aliphatic polyester resin composition of the present invention, 0.01 to 10 parts by weight of the carbodiimide compound (C) may be further added per 100 parts by weight of the aliphatic polyester resin (A). Moreover, 1-15 weight part of fillers (D) may be further mix | blended per 100 weight part of aliphatic polyester-type resin (A). Moreover, 0.1-20 weight part of plasticizers (E) may be further mix | blended per 100 weight part of aliphatic polyester-type resin (A).

  The molded article of the present invention is obtained by molding the aliphatic polyester resin composition of the present invention, and has sufficient flexibility, decomposition characteristics under natural environment and excellent mechanical characteristics, particularly excellent. It has tear strength and impact strength and is particularly useful for film applications.

  ADVANTAGE OF THE INVENTION According to this invention, the aliphatic polyester-type resin molding which has sufficient flexibility, the decomposition characteristic in a natural environment, and the outstanding mechanical characteristic, especially the outstanding tear strength and impact strength is provided.

Embodiments of the present invention are described in detail below.
<Aliphatic polyester resin (A)>
The aliphatic polyester-based resin (A) has an aliphatic and / or alicyclic diol unit and an aliphatic and / or alicyclic dicarboxylic acid unit as essential components, and has a glass transition temperature of 0 ° C. or lower, 190 ° C., 2. The MFR measured with a 16 kg load is 10 g / 10 min or less. Preferably, the aliphatic polyester resin (A) is an aliphatic and / or alicyclic diol unit represented by the following formula (1), and an aliphatic and / or alicyclic represented by the following formula (2). It has a formula dicarboxylic acid unit as an essential component.
—O—R ¹ —O— (1)
^-OC-R 2 -CO- (2)
(In the above formulas (1) and (2), R ¹ is a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, R ² is a direct bond, a divalent aliphatic hydrocarbon group or Represents a divalent alicyclic hydrocarbon group.)

  The diol component (a-1) that gives the diol unit of the formula (1) is usually one having 2 to 10 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like can be mentioned, among which ethylene glycol and 1,4-butanediol are preferable, and 1,4-butanediol is particularly preferable.

  The dicarboxylic acid component (a-2) giving the carboxylic acid unit of the formula (2) is usually one having 2 to 10 carbon atoms, for example, succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid Among them, succinic acid and adipic acid are preferable.

  In addition, the said diol component (a-1) and dicarboxylic acid component (a-2) can also use 2 or more types, respectively.

  Also, two or more different aliphatic polyester resins (A) can be blended and used. Specifically, the aliphatic polyester resin (A-1) in which (a-1) is 1,4-butanediol and (a-2) is succinic acid, and (a-1) is 1,4- Examples include butanediol and a blend of an aliphatic polyester resin (A-2) in which (a-2) is succinic acid and adipic acid.

  The aliphatic polyester resin (A) used in the present invention may further contain an aliphatic oxycarboxylic acid unit.

  Specific examples of the aliphatic oxycarboxylic acid component that gives an aliphatic oxycarboxylic acid unit include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, Examples thereof include 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, or a mixture thereof. Or these lower alkyl ester and intramolecular ester may be sufficient. In addition, when optical isomers exist in these, any of D-form, L-form, and racemate may be used, and the form may be any of solid, liquid, or aqueous solution. Among these, lactic acid or glycolic acid is preferable. These aliphatic oxycarboxylic acid components can be used alone or as a mixture of two or more.

  As for the content of the aliphatic oxycarboxylic acid component, the lower limit is usually 0 mol% or more, preferably 0.01 mol% or more, and the upper limit is normal among all the components constituting the aliphatic polyester resin (A). It is 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less.

  Further, the aliphatic polyester resin (A) of the present invention is a tri- or higher functional aliphatic and / or alicyclic polyhydric alcohol, aliphatic and / or alicyclic polycarboxylic acid or anhydride thereof, or fat. When an aliphatic polyoxycarboxylic acid is contained as a copolymerization component, the melt viscosity of the resulting aliphatic polyester can be increased, which is preferable. In this case, specific examples of the trifunctional aliphatic or alicyclic polyhydric alcohol include trimethylolpropane, glycerin or its anhydride, and specific examples of the tetrafunctional aliphatic or alicyclic polyhydric alcohol. May be pentaerythritol. Specific examples of the trifunctional aliphatic or alicyclic polycarboxylic acid or its anhydride include propanetricarboxylic acid or its anhydride, and a tetrafunctional aliphatic or alicyclic polycarboxylic acid or its anhydride. Specific examples of the product include cyclopentanetetracarboxylic acid or its anhydride. In addition, the trifunctional aliphatic oxycarboxylic acid component includes (i) a type having two carboxyl groups and one hydroxyl group in the same molecule, and (ii) one carboxyl group and two hydroxyl groups. These types are divided into types having a group in the same molecule, and any type can be used. Specific examples include (i) type malic acid. In addition, the tetrafunctional aliphatic oxycarboxylic acid component includes (i) a type having three carboxyl groups and one hydroxyl group in the same molecule, and (ii) two carboxyl groups and two hydroxyl groups. And (iii) a type having three hydroxyl groups and one carboxyl group in the same molecule, and any type can be used. Specific examples include citric acid and tartaric acid. These trifunctional or higher functional components can be used singly or in combination of two or more.

  The content of such a trifunctional or higher component is generally 0 mol% or more, preferably 0.01 mol% or more, and the upper limit of all components constituting the aliphatic polyester resin (A). Usually, it is 5 mol% or less, preferably 2.5 mol% or less.

  The aliphatic polyester resin (A) used in the present invention can be produced by a known method. For example, in the case of introducing the dicarboxylic acid component (a-2) and the diol component (a-1), and an aliphatic oxycarboxylic acid unit or a trifunctional or higher component, the dicarboxylic acid component including these components A general method of melt polymerization, such as a polycondensation reaction under reduced pressure after an esterification reaction and / or a transesterification reaction between a diol component and a diol component, and a known solution heating dehydration condensation method using an organic solvent However, from the viewpoint of economy and simplicity of the production process, a melt polymerization method carried out in the absence of a solvent is preferred.

  The polycondensation reaction is preferably performed in the presence of a polymerization catalyst. The addition timing of the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added when the raw materials are charged, or may be added at the start of pressure reduction.

  As the polymerization catalyst, in general, a compound containing a group 1 to group 14 metal element excluding hydrogen and carbon in the periodic table can be used. Specifically, at least one metal selected from the group consisting of titanium, zirconium, tin, antimony, cerium, germanium, zinc, cobalt, manganese, iron, aluminum, magnesium, calcium, strontium, sodium, and potassium. And compounds containing an organic group such as carboxylate, alkoxy salt, organic sulfonate, or β-diketonate salt, and inorganic compounds such as metal oxides and halides described above, and mixtures thereof.

  Among these, metal compounds containing titanium, zirconium, germanium, zinc, aluminum, magnesium and calcium, and mixtures thereof are preferable, and among these, titanium compounds and germanium compounds are particularly preferable. In addition, the catalyst is preferably a compound that is liquid at the time of polymerization or that dissolves in an ester low polymer or polyester because the polymerization rate increases when it is melted or dissolved at the time of polymerization.

  The amount of catalyst added in the case of using a metal compound as the polymerization catalyst, the lower limit is usually 5 ppm or more, preferably 10 ppm or more, and the upper limit is usually 30000 ppm or less, preferably 1000 ppm or less, as the amount of metal relative to the produced polyester. More preferably, it is 250 ppm or less, Especially preferably, it is 130 ppm or less. If too much catalyst is used, it is not only economically disadvantageous but also lowers the thermal stability of the polymer. Conversely, if it is too little, the polymerization activity is lowered, and as a result, the polymer decomposes during polymer production. Is more likely to be triggered.

  The lower limit of the esterification reaction and / or transesterification reaction temperature between the dicarboxylic acid component and the diol component is usually 150 ° C or higher, preferably 180 ° C or higher, and the upper limit is usually 260 ° C or lower, preferably 250 ° C or lower. The reaction atmosphere is usually an inert gas atmosphere such as nitrogen or argon. The reaction pressure is usually normal pressure to 10 kPa, but normal pressure is preferred.

  The lower limit of the reaction time is usually 1 hour or longer, and the upper limit is usually 10 hours or shorter, preferably 4 hours or shorter.

In the polycondensation reaction after the esterification reaction and / or transesterification reaction between the dicarboxylic acid component and the diol component, the pressure is usually 0.01 × 10 ³ Pa or more, preferably 0.01 × 10 ³ Pa or more. Yes, the upper limit is usually 1.4 × 10 ³ Pa or less, preferably 0.4 × 10 ³ Pa or less. At this time, the lower limit of the reaction temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher, and the upper limit is usually 260 ° C. or lower, preferably 250 ° C. or lower. The lower limit of the reaction time is usually 2 hours or more, and the upper limit is usually 15 hours or less, preferably 10 hours or less.

  In the present invention, a known vertical or horizontal stirred tank reactor can be used as a reactor for producing the aliphatic polyester resin (A). For example, using the same or different reaction apparatus, it is carried out in two stages, that is, a step of esterification and / or transesterification of melt polymerization and a step of polycondensation under reduced pressure. A method of using a stirred tank reactor equipped with a evacuation pipe for decompression to be connected can be mentioned. Also, it is preferable to use a method in which a condenser is connected between the exhaust pipe for decompression connecting the vacuum pump and the reactor, and the volatile components and unreacted monomers generated during the polycondensation reaction are recovered by the condenser. It is done.

  In the present invention, the molar ratio of the diol component and the dicarboxylic acid component for obtaining the aliphatic polyester resin (A) having the desired degree of polymerization is different in the preferred range depending on the purpose and the kind of raw material, but the dicarboxylic acid component The lower limit of the amount of the diol component relative to 1 mol is usually 0.8 mol or more, preferably 0.9 mol or more, and the upper limit is usually 1.5 mol or less, preferably 1.3 mol or less, particularly preferably 1. 2 mol or less.

  Moreover, an amide bond, a carbonate bond, an ether bond, etc. can be introduce | transduced into an aliphatic polyester-type resin (A) in the range which does not affect biodegradability.

  Various additives such as a heat stabilizer may be added to the aliphatic polyester-based resin (A) during the production process of the aliphatic polyester-based resin (A) or within the range in which the characteristics are not impaired. Further, an antioxidant, a crystal nucleating agent, a flame retardant, an antistatic agent, a release agent, an ultraviolet absorber, and the like may be added. The same applies to the aliphatic oxycarboxylic acid resin (B) and carbodiimide compound (C) described later.

  The aliphatic polyester resin (A) used in the present invention needs to have a glass transition temperature of 0 ° C. or lower. When the glass transition temperature exceeds 0 ° C., flexibility is lowered, which is not preferable. The glass transition temperature is preferably −120 ° C. or higher and −5 ° C. or lower. The glass transition temperature of the aliphatic polyester resin (A) can be observed by measuring the viscoelasticity in a solid state. For example, “RMS800” manufactured by Rheometric Scientific F.E. The measurement of observing the response signal when sine wave vibration of 1 Hz is applied to the test piece is performed by sequentially changing the temperature from the low temperature side, and the peak temperature of the loss tangent calculated from the response signal is recorded. be able to.

  The aliphatic polyester resin (A) used in the present invention is required to have an MFR measured at 190 ° C. and a load of 2.16 kg of 10 g / 10 min or less. If the MFR exceeds 10 g / 10 min, the moldability of the resulting aliphatic polyester resin composition is inferior, which is not preferable. The lower limit of this MFR is usually 0.1 g / 10 min or more, and the upper limit is preferably 8 g / 10 min or less.

  In the present invention, the aliphatic polyester-based resin (A) is not limited to one type, and as described above, two or more types of aliphatic polyester-based resins (A) having different types, component ratios, manufacturing methods, and the like are blended. Can be used.

<Aliphatic oxycarboxylic acid resin (B)>
The aliphatic oxycarboxylic acid resin (B) has an aliphatic oxycarboxylic acid unit as an essential component, and has an MFR measured at a glass transition temperature of 30 ° C. or higher, 190 ° C., and 2.16 kg load. The MFR of the aliphatic polyester resin (A) is 1.2 times or more. The aliphatic oxycarboxylic acid unit is preferably represented by the following formula (3).
—O—R ³ —CO— (3)
(In the above formula (3), R ³ represents a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group.)

  Specific examples of the aliphatic oxycarboxylic acid component (b-3) giving the aliphatic oxycarboxylic acid unit of the formula (3) include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 2 -Hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, or a mixture thereof. When optical isomers exist in these, any of D-form and L-form may be sufficient. Among these, lactic acid or glycolic acid is preferable. These aliphatic oxycarboxylic acid components (b-3) can be used in a mixture of two or more.

  In addition, a urethane bond, an amide bond, a carbonate bond, an ether bond, and the like can be introduced into the aliphatic oxycarboxylic acid resin (B) as long as the biodegradability is not affected.

  The production method of the aliphatic oxycarboxylic acid resin (B) used in the present invention is not particularly limited, and is produced by a known method such as a direct polymerization method of oxycarboxylic acid or a ring-opening polymerization method of a cyclic product. be able to.

  The aliphatic oxycarboxylic acid resin (B) used in the present invention needs to have a glass transition temperature of 30 ° C. or higher. In the aliphatic oxycarboxylic acid resin (B) having a glass transition temperature of less than 30 ° C., the effect of improving the mechanical properties becomes small. The glass transition temperature is preferably 40 ° C. or higher, and usually 90 ° C. or lower. The glass transition temperature of the aliphatic oxycarboxylic acid resin (B) can be measured by the same method as that described in the section of the aliphatic polyester resin (A).

  The aliphatic oxycarboxylic acid resin (B) used in the present invention may be either crystalline or amorphous. However, it is preferable that the aliphatic oxycarboxylic acid resin (B) has crystallinity because the hydrolyzability of the resulting film can be suppressed. The determination of crystallinity / amorphous is the melting peak when the sample once melted in the differential scanning calorimeter measurement is cooled and solidified at 10 ° C./min and then heated at a rate of 10 ° C./min. It can be implemented depending on the presence or absence of.

  In the aliphatic oxycarboxylic acid resin (B) used in the present invention, the lower limit of MFR measured at 190 ° C. and a load of 2.16 kg is usually 0.1 g / 10 min or more, and the upper limit is usually 100 g / 10 min. Hereinafter, it is preferably 70 g / 10 min or less, more preferably 50 g / 10 min or less. The MFR of the aliphatic oxycarboxylic acid resin (B) needs to be 1.2 times or more the MFR of the aliphatic polyester resin (A). When this multiple is less than 1.2, the effect of improving the mechanical properties by blending the aliphatic oxycarboxylic acid resin (B) is unfavorable. This multiple is preferably 1.4 or more, more preferably 1.6 or more, and the upper limit is usually 30 or less, preferably 20 or less.

  As for the aliphatic oxycarboxylic acid resin (B), one kind may be used alone, and two or more kinds of aliphatic oxycarboxylic acid resins (B) having different kinds of components, component ratios, production methods, etc. may be used. It can also be used by blending.

In addition, when using 2 or more types of aliphatic polyester-type resin (A), or when using 2 or more types of aliphatic oxycarboxylic acid-type resin (B), the comparison of MFR and MFR of each resin, its ratio, The apparent MFR is calculated from the above and the calculated MFR is compared.
For example, as the aliphatic polyester resin (A), MFR is M _a-1 g / 10 min. Aliphatic polyester resin (A-1) x wt%, and MFR is M _a-2 g / 10 min. When an aliphatic polyester-based resin (A-2) y% by weight is used in a mixture of 100% by weight in total, the apparent MFR is log [MFR] =
(X / 100) × log [M _a-1 ] + (y / 100) × log [M _a-2 ]
Can be obtained by calculation. The same applies to the aliphatic oxycarboxylic acid resin (B). Therefore, it is preferable to select a resin to be used so that the coefficient is 1.2 times or more with respect to the apparent MFR thus obtained by calculation.

<Carbodiimide compound (C)>
A carbodiimide compound (C) can be suitably mix | blended with the aliphatic polyester-type resin composition of this invention mainly in order to suppress the hydrolysis by the water | moisture content etc. in air | atmosphere.

  The carbodiimide compound (C) used is a compound (including a polycarbodiimide compound) having one or more carbodiimide groups in the molecule. Such a carbodiimide compound includes, for example, an organophosphorus compound or an organometallic compound as a catalyst. It can be synthesized by subjecting the isocyanate compound to a decarboxylation condensation reaction in a solvent-free or inert solvent at a temperature of 70 ° C. or higher.

  Among the above carbodiimide compounds, the monocarbodiimide compounds include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, and di-β-naphthylcarbodiimide. Etc. can be illustrated. 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), and Chemical Review 1981, 81, No. 4, p. What was manufactured by the method described in 619-621 grade | etc., Can be used.

  Examples of organic diisocyanates that are raw materials for producing polycarbodiimide compounds include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures thereof. Specifically, 1,5-naphthalene diisocyanate, 4, 4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4- A mixture of tolylene diisocyanate and 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate , Dicyclohexylmethane-4,4′-diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl isocyanate, 1,3,5-triisopropylbenzene-2,4-diisocyanate, etc. Can do.

  Examples of the carbodiimidization catalyst used in the decarboxylation condensation reaction of organic diisocyanate include organophosphorus compounds and organometallic compounds represented by the general formula M (OR) n (where M is titanium, sodium, potassium, vanadium, tungsten, hafnium). , Zirconium, lead, manganese, nickel, calcium, barium or the like, R represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and n can be a metal atom M. Is preferred). Among them, phospholene oxides are preferable for organic phosphorus compounds, and alcosides of titanium, hafnium, or zirconium are preferable for organic metal compounds.

  Specific examples of the phospholene oxides include 3-methyl-1-phenyl-2-phospholene-1-oxide, 3-methyl-1-ethyl-2-phospholene-1-oxide, and 1,3-dimethyl-2. -Phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-methyl-2-phospholene-1-oxide and their double bond isomers Can be illustrated. Of these, 3-methyl-1-phenyl-2-phospholene-1-oxide, which is easily available industrially, is particularly preferable.

  When synthesizing these polycarbodiimide compounds, a desired degree of polymerization can be controlled by using an active hydrogen-containing compound capable of reacting with monoisocyanate or other terminal isocyanate groups. Compounds used for such purposes include monoisocyanate compounds such as phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate, methanol, ethanol, phenol, cyclohexanol, N-methylethanolamine, Hydroxyl group-containing compounds such as polyethylene glycol monomethyl ether and polypropylene glycol monomethyl ether, amino group-containing compounds such as diethylamine, dicyclohexylamine, β-naphthylamine and cyclohexylamine, carboxyl group-containing compounds such as succinic acid, benzoic acid and cyclohexane acid, ethyl mercaptan , Mercapto group-containing compounds such as allyl mercaptan and thiophenol, It can be exemplified fine various epoxy group-containing compound.

  These carbodiimide compounds (C) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  In the present invention, it is particularly preferable to use a polycarbodiimide compound, and the degree of polymerization of the lower limit is 2 or more, preferably 4 or more, and the upper limit is usually 40 or less, preferably 20 or less. If the degree of polymerization is too large, dispersibility in the composition becomes insufficient, and for example, it may cause poor appearance in an inflation film.

[Filler (D)]
In the present invention, the filler (E) can be blended from the viewpoints of stabilization during film forming by improving the fluidity and crystallization speed of the resin composition, and reducing the anisotropic properties of film mechanical properties.

  Depending on the shape of the filler used, there are fibrous, powdery and plate-like fillers, and powdery and plate-like fillers are preferred. As the granular filler, mineral particles such as talc, zeolite, diatomaceous earth, kaolin, clay, silica, quartz powder, metal carbonate particles such as calcium carbonate, magnesium carbonate, heavy calcium carbonate, calcium silicate, aluminum silicate, Examples thereof include metal silicate particles such as magnesium silicate, metal oxide particles such as alumina, silica, zinc oxide and titanium dioxide, and metal hydroxide particles such as aluminum hydroxide, calcium hydroxide and magnesium hydroxide. Moreover, mica is mentioned as a plate-shaped filler. Of these fillers, talc, calcium carbonate, and mica are preferred because of their dispersibility and dispersion form.

  The dispersion state of the filler in a molded body such as a film or the resin composition is 0.08 to 5 μm, more preferably 0.1 to 4 μm in terms of number average particle diameter. When it deviates from this range, the addition effect of the said filler will become low.

  These fillers (D) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

[Plasticizer (E)]
In the present invention, the plasticizer (E) can be blended from the viewpoint of improving film mechanical properties such as impact strength.

  The plasticizer to be used is not particularly limited, and specifically, methyl adipate, diethyl adipate, diisopropyl adipate, di-n-propyl adipate, di-2-ethylhexyl adipate, diisobutyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol Fatty acid esters such as adipate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, methylacetyl lysylate, glycerin ester such as triacetin, diethyl maleate, dibutyl maleate, dioctyl maleate, dibutyl Maleic acid and fumaric acid ester such as fumarate and dioctyl fumarate, polyester epoxidation ester such as adipic acid 1,3-butylene glycol and epoxidized soybean oil Trimellitic acid esters such as tellurium and trioctyl trimellitate, triethylene glycol diacetate, tributyl acetylcitrate, glycerin diacetomonopropionate, glycerin diacetomonocaprylate, glycerin diacetomonocaprate, glycerin diacetomonolaurate, Acetylated monoglycerides such as glycerin diacetomonooleate, glycerin monoacetomonobehenate, glycerin monoacetomonostearate, diglycerin acetate, decaglycerin propionate, tetraglycerin caprylate, decaglycerin laurate, decaglycerin oleate, decaglycerin Examples thereof include polyglycerin fatty acid esters such as behenate, rosin derivatives and the like.

  Among them, epoxidized soybean oil, acetylated monoglycerides such as glycerin diacetomonocaprylate, glycerin diacetomonolaurate, and glycerin diacetomonooleate, diglycerin acetate, decaglycerin caprylate, decaglycerin laurate, decaglycerin oleate, and the like are preferable. Polyglycerol fatty acid ester, adipic acid ester, and tributyl acetylcitrate.

  These plasticizers (E) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

<Combination ratio>
The content ratio of the aliphatic oxycarboxylic acid resin (B) in the aliphatic polyester resin composition of the present invention containing the aliphatic polyester resin (A) and the aliphatic oxycarboxylic acid resin (B) is: A) For 100 parts by weight, the lower limit is 1 part by weight or more, preferably 2 parts by weight or more, more preferably 3 parts by weight or more, and the upper limit is 50 parts by weight or less, preferably 40 parts by weight or less, more preferably 30 parts by weight. Or less. If the amount of the aliphatic oxycarboxylic acid resin (B) is too small or too large than this range, the effect of improving the mechanical properties such as impact strength of the film tends to be low, which is not preferable.

  Moreover, the mixing | blending ratio of the carbodiimide compound (C) to the aliphatic polyester-type resin composition of this invention has a minimum of 0.01 weight part or more normally per 100 weight part of aliphatic polyester-type resin (A), Preferably it is 0. 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more, and the upper limit is usually 10 parts by weight or less, preferably 5 parts by weight or less, particularly preferably 3 parts by weight or less. If the amount of the carbodiimide compound (C) is too small, the hydrolysis inhibiting effect tends to be insufficient, and if it is too large, the effect of addition is saturated and an effect commensurate with the increase in the amount of addition cannot be obtained.

  The blending ratio of the filler (D) to the aliphatic polyester resin composition of the present invention is such that the lower limit is 0 part by weight or more, usually 1 part by weight or more per 100 parts by weight of the aliphatic polyester resin (A). Preferably it is 1.5 parts by weight or more, particularly preferably 2 parts by weight or more, and the upper limit is usually 15 parts by weight or less, preferably 10 parts by weight or less, particularly preferably 8 parts by weight or less. If the amount of the filler (D) is too large, the film impact strength and the like are lowered, which is not preferable.

  Further, the blending ratio of the plasticizer (E) to the aliphatic polyester resin composition of the present invention is such that the lower limit is 0 part by weight or more and usually 0.1 part by weight per 100 parts by weight of the aliphatic polyester resin (A). Above, preferably 0.3 parts by weight or more, particularly preferably 0.5 parts by weight or more, and the upper limit is usually 20 parts by weight or less, preferably 15 parts by weight or less, particularly preferably 10 parts by weight or less. When there are too many compounding quantities of a plasticizer (E), the heat resistance of a composition may be inferior or the bleed-out of a plasticizer may arise.

<Other ingredients>
The aliphatic polyester resin composition of the present invention comprises an aliphatic polyester resin (A), an aliphatic oxycarboxylic acid resin (B), a carbodiimide compound (C) used as necessary, and a filler (D ), Other biodegradable resins, such as polycaprolactone, polyamide, polyvinyl alcohol, cellulose ester, aromatic-aliphatic copolyester resin, etc., as long as the effects of the present invention are not impaired, other than the plasticizer (E). Furthermore, starch, cellulose, paper, wood powder, chitin / chitosan, animal / plant substance fine powder such as coconut shell powder, walnut shell powder, or a mixture thereof can be blended. Furthermore, additives such as heat stabilizers, lubricants, antiblocking agents, nucleating agents, colorants, pigments, UV absorbers, light stabilizers, modifiers, crosslinks are used for the purpose of adjusting the physical properties and processability of the molded product. It is also possible to add an agent or the like.

<Manufacturing method>
Although the manufacturing method of the aliphatic polyester-type resin composition of this invention is not specifically limited, The raw material chip | tip of the blended aliphatic polyester-type resin (A) and aliphatic oxycarboxylic acid-type resin (B) is used with the same extruder. Examples thereof include a method of melting and mixing, a method of mixing after melting with separate extruders, and the like. In addition, it is possible to obtain the molded body at the same time as preparing the resin composition by supplying each raw material chip directly to the molding machine.

  The carbodiimide compound (C), the filler (D), and the plasticizer (E) may be added together or independently during the preparation of such a composition, or the aliphatic polyester resin (A) and It is also possible to knead and mix with any one or two components of the aliphatic oxycarboxylic acid resin (B) and dry blend with the remaining components during molding. Alternatively, a master batch containing an aliphatic polyester resin (A) and / or an aliphatic oxycarboxylic acid resin (B) containing a high concentration of carbodiimide compound (C), filler (D), and plasticizer (E) is prepared. The aliphatic polyester resin (A) and / or the aliphatic oxycarboxylic acid resin (B) so that the carbodiimide compound (C), the filler (D), and the plasticizer (E) each have a predetermined concentration during molding. ) May be dry blended and diluted.

  The method for molding the aliphatic polyester resin composition of the present invention is not particularly limited, such as hot press molding, injection molding, extrusion molding, etc., but the effect of the present invention is particularly remarkable in a film-like molded body obtained by extrusion molding. appear. That is, the film in which the aliphatic polyester resin composition of the present invention is molded has sufficient tensile elongation, tear strength, and impact strength.

  As a method for obtaining a film-like molded body, for example, a film, sheet or cylinder extruded from a T die, I die, round die or the like to a predetermined thickness is cooled and solidified by a cooling roll, water, compressed air or the like. And the like. Under the present circumstances, it can also be set as the laminated | multilayer film which laminated | stacked several types of compositions in the range which does not inhibit the effect of this invention.

  The film-like molded product thus obtained may then be uniaxially or biaxially stretched by a roll method, a tenter method, a tubular method or the like. In the case of stretching, the stretching temperature is usually in the range of 30 to 110 ° C., and the stretching ratio is usually in the range of 0.6 to 10 times in the longitudinal and lateral directions, respectively. Moreover, after extending | stretching, you may perform heat processing, such as the method of spraying a hot air, the method of irradiating infrared rays, the method of irradiating a microwave, and making it contact on a heat roll.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

  In addition, the glass transition temperature in the following examples used "RMS800" manufactured by Rheometric Scientific F.E., and applied a 1 Hz sinusoidal vibration to a test piece having a length of 45 mm, a width of 12 mm, and a thickness of 2 mm. The measurement of observing the response signal was performed while changing the temperature sequentially from the low temperature side, and the peak temperature of the loss tangent calculated from the response signal was recorded.

  Further, using a differential scanning calorimeter manufactured by PerkinElmer Co., Ltd., product name: DSC7, a 10 mg sample was heated and melted at a rate of 10 ° C./min under a nitrogen stream at a flow rate of 50 mL / min, and then 10 ° C./min. The melting point was defined as the melting peak temperature when the mixture was once cooled and solidified at a rate of 10 ° C. and then heated at a rate of 10 ° C./min.

  Each component used for manufacture of an aliphatic polyester-type resin composition is as follows.

(1) Aliphatic polyester resin (A)
[Aliphatic polyester resin (A1)]
In a reaction vessel having a capacity of 1 m ³ equipped with a stirrer, a nitrogen inlet, a heating device, a thermometer and a vacuum port, 76.9 kg of succinic acid, 24.8 kg of adipic acid, 84.3 liters of 1,4-butanediol, DL Malic acid 0.24 kg and 90% DL lactic acid aqueous solution 5.4 kg in which 1% by weight of germanium oxide was dissolved in advance were charged. Nitrogen gas was introduced while stirring the contents of the container, the reaction was started from 120 ° C. under a nitrogen gas atmosphere, and the temperature was raised to 200 ° C. over 1 hour and 40 minutes. Subsequently, the temperature was raised to 230 ° C. over 1 hour and 25 minutes, and at the same time, the pressure was reduced to 1 mmHg (133 Pa), and polymerization was performed at 230 ° C. and 1 mmHg (133 Pa) for 4 hours to obtain an aliphatic polyester resin (A1).

  MFR (190 degreeC, 2.16kg load) of the obtained aliphatic polyester-type resin (A1) was 4.2 g / 10min, glass transition temperature was -38 degreeC, and melting | fusing point was 88 degreeC. The malic acid component in this aliphatic polyester resin (A1) was 0.16 mol%.

[Aliphatic polyester resin (A2)]
In a reaction vessel having a capacity of 1 m ³ equipped with a stirrer, a nitrogen inlet, a heating device, a thermometer, and a pressure reducing port, 134 kg of succinic acid, 116 liters of 1,4-butanediol, 0.24 kg of DL malic acid, and germanium oxide were previously added. 7.21 kg of 90% DL lactic acid aqueous solution dissolved 1% by weight was charged. Nitrogen gas was introduced while stirring the contents of the container, the reaction was started from 120 ° C. under a nitrogen gas atmosphere, and the temperature was raised to 200 ° C. over 1 hour and 40 minutes. Subsequently, the temperature was raised to 230 ° C. over 1 hour and 25 minutes, and at the same time, the pressure was reduced to 1 mmHg (133 Pa), and polymerization was performed at 230 ° C. and 1 mmHg (133 Pa) for 4 hours and 20 minutes to obtain an aliphatic polyester resin (A2). .

  MFR (190 degreeC, 2.16kg load) of the obtained aliphatic polyester-type resin (A2) was 3.8 g / 10min, glass transition temperature was -25 degreeC, and melting | fusing point was 110 degreeC. The malic acid component in this aliphatic polyester resin (A2) was 0.15 mol%.

(2) Aliphatic oxycarboxylic acid resin (B)
[Aliphatic Oxycarboxylic Acid Resin (B1)]
Polylactic acid having an MFR (190 ° C., 2.16 kg load) of 30 g / 10 min and a glass transition temperature of 65 ° C. was used. In the DSC measurement, the melting point was 166 ° C.
[Aliphatic oxycarboxylic acid resin (B2)]
Polylactic acid having an MFR (190 ° C., 2.16 kg load) of 20 g / 10 min and a glass transition temperature of 63 ° C. was used. In the DSC measurement, no melting point was observed.
[Aliphatic oxycarboxylic acid resin (B3)]
Polylactic acid having an MFR (190 ° C., 2.16 kg load) of 8.1 g / 10 min and a glass transition temperature of 65 ° C. was used. In the DSC measurement, the melting point was 166 ° C.
[Aliphatic oxycarboxylic acid resin (B4)]
Polylactic acid having an MFR (190 ° C., 2.16 kg load) of 4.1 g / 10 min and a glass transition temperature of 65 ° C. was used. In the DSC measurement, the melting point was 165 ° C.
[Aliphatic oxycarboxylic acid resin (B5)]
Polylactic acid having an MFR (190 ° C., 2.16 kg load) of 3.9 g / 10 min and a glass transition temperature of 63 ° C. was used. In the DSC measurement, no melting point was observed.

(3) Carbodiimide compound (C)
A polycarbodiimide obtained by condensing dicyclohexylmethane-4,4′-diisocyanate (softening temperature 70 ° C., thermal decomposition temperature 340 ° C., polymerization degree 8 to 12) was used.

(4) Filler (D)
A talc “MT-13” average particle size of 4.1 μm manufactured by Fuji Talc was used.

(5) Plasticizer (E)
Adipic acid ester “DAIFATTY-101” manufactured by Daihachi Chemical Co., Ltd. was used.

Examples 1-8 and Comparative Examples 1-5
Tables 1 and 2 show aliphatic polyester resins (A1) and (A2), aliphatic oxycarboxylic acid resins (B1) to (B5), carbodiimide compounds (C), fillers (D), and plasticizers (E). In the composition shown in (1) above, the mixture was kneaded at 190 ° C. with a twin-screw kneader and subjected to inflation molding at 175 ° C. to obtain a 25 μm thick film. At that time, the blow ratio was 2.5.

The following evaluation was implemented about the obtained film. The results are shown in Tables 1 and 2. In addition, MD represents the flow direction at the time of film forming, and TD represents the perpendicular direction.
<Tensile properties (tensile yield strength, tensile elongation at break)>
It measured based on JISK6781.
<Elmendorf tear strength>
The measurement was performed according to JIS K7128.
<Punching impact strength>
Using a film impact tester manufactured by Toyo Seiki Co., Ltd., the punching impact strength of a film having a diameter of 50 mm was measured according to JIS P8134. The evaluation was performed by attaching a hemispherical metal jig having a diameter of 25.4 mm to the tip of the impact tester punched portion.
<Biodegradability>
It was buried in the field and its biodegradability was observed.
○: Perforation is observed in the film after 2 months. Or it has disappeared.
X: No change in appearance after 2 months.

  The aliphatic polyester resin molded article provided by the present invention is excellent in mechanical properties such as tear strength and impact strength while having degradability in a natural environment. It is suitably used in a wide range of applications such as liquids and powders, solid packaging materials, agricultural materials, and building materials.

Claims (6)

The following aliphatic polyester-based resin (A) having a glass transition temperature of 0 ° C. or lower and 190 ° C. and an MFR measured with a 2.16 kg load of 10 g / 10 min or less,
The following aliphatic oxycarboxylic acid resin (MFR measured at a glass transition temperature of 30 ° C. or higher, 190 ° C. and 2.16 kg load) is 1.2 times or more of the MFR of the aliphatic polyester resin (A) ( B) and a resin composition comprising
(A) An aliphatic polyester-based resin composition comprising 1 to 50 parts by weight of (B) with respect to 100 parts by weight.
[Aliphatic polyester resin (A)]
Aliphatic polyester resin [aliphatic oxycarboxylic acid resin (B)] having an aliphatic and / or alicyclic diol unit and an aliphatic and / or alicyclic dicarboxylic acid unit as essential components
Aliphatic oxycarboxylic acid resin having an aliphatic oxycarboxylic acid unit as an essential component   The aliphatic polyester resin composition according to claim 1, wherein 0.01 to 10 parts by weight of the carbodiimide compound (C) is blended per 100 parts by weight of the aliphatic polyester resin (A).   The aliphatic polyester resin composition according to claim 1 or 2, wherein 1 to 15 parts by weight of the filler (D) is blended per 100 parts by weight of the aliphatic polyester resin (A).   The aliphatic polyester resin composition according to any one of claims 1 to 3, wherein 0.1 to 20 parts by weight of a plasticizer (E) is blended per 100 parts by weight of the aliphatic polyester resin (A). object.   The molded object formed by shape | molding the aliphatic polyester-type resin composition of any one of Claims 1 thru | or 4.   The molded product according to claim 5, which is a film.