WO2006101076A1

WO2006101076A1 - Aliphatic polyester resin composition and molded body

Info

Publication number: WO2006101076A1
Application number: PCT/JP2006/305547
Authority: WO
Inventors: Madoka Furuta; Michihiro Kaai; Yasumasa Horibe; Takeshi Kanamori
Original assignee: Toagosei Co., Ltd.; Toyota Jidosha Kabushiki Kaisha
Priority date: 2005-03-24
Filing date: 2006-03-20
Publication date: 2006-09-28
Also published as: JP4672409B2; CN101103072B; JP2006265399A; CN101103072A

Abstract

Disclosed is an aliphatic polyester resin composition wherein an acrylic resin-based modifier (B) is contained in an amount of 0.15-1 part by mass per 100 parts by mass of an aliphatic polyester resin (A). The aliphatic polyester resin (A) mainly contains a polymer having a lactic acid unit, and the lactide or lactic acid content is less than 0.2% by mass. The acrylic resin-based modifier (B) has a glass transition temperature (Tg) of not less than 0˚C, an average number of epoxy groups per molecule of 3-30, and a mass average molecular weight of 1,000-30,000. For example, a copolymer of glycidyl methacrylate and styrene is used as the acrylic resin-based modifier (B).

Description

Specification

Aliphatic polyester resin composition and molded article

Technical field

The present invention relates to an aliphatic polyester resin composition having excellent thermal stability and molding processability, and a molded body thereof.

Background art

[0002] In recent years, from the viewpoint of protecting the natural environment, biodegradable polymers that can be decomposed in the natural environment and molded articles thereof have been demanded. ing. Among natural degradable resins, polylactic acid is recently gaining attention as a bioplastic because it is obtained from plant-derived raw materials such as corn, sugar cane, and sweet potato. Materials obtained from these plant raw materials are easily converted into water and carbon dioxide by combustion (pyrolysis) or biodegradation. This carbon dioxide is originally stored in the plant by photosynthesis. Therefore, bioplastics are environmentally friendly plastics because they do not increase the concentration of carbon dioxide in the atmosphere during combustion or biodegradation.

[0003] Among the many aliphatic polyester resins, polylactic acid has a feature that its melting point is higher than that of other aliphatic polyester resins and it has excellent heat resistance. However

Since the melted polylactic acid has a low melt viscosity and melt tension, it causes necking during molding of, for example, a finale or a sheet, resulting in unstable thickness and width of the film, and breakage of the yarn during fiber molding. Or cause Also, problems can easily occur when the frost line of inflation molding becomes unstable, or when the blow molding nozzle is drawn down and the molded product becomes uneven.

[0004] Conventionally, as a means for improving the melt viscosity and melt tension, a composition in which a long-chain branched polymer is produced using a polyfunctional polymerization initiator in the polymerization process of an aliphatic polyester resin is known. ing. By introducing such a branched chain, the melt viscosity and the melt tension are improved, but due to the long polymerization time and complicated operation, there is a problem that the practicality is poor. Therefore, the crosslinked structure and branched structure in the post-process after polymerization are introduced. An introduced resin composition is proposed.

[0005] For example, Patent Document 1 discloses a biodegradable polyester resin composition comprising a biodegradable polyester resin, a biodegradable aliphatic monoaromatic copolymer polyester resin, and a (meth) acrylate compound. Is disclosed. Patent Document 2 discloses a biodegradable resin film or sheet in which a specific epoxy compound is blended with a biodegradable resin and has excellent hydrolysis resistance. Patent Document 3 discloses a biodegradable resin composition comprising a biodegradable polyester resin containing polylactic acid and a layered silicate, and further containing a reactive compound having an epoxy group.

[0006] Patent Document 4 discloses a polylactic acid resin composition comprising polylactic acid, an aliphatic polyester other than polylactic acid, and a modified olefin compound. The modified olefin compound contains an ethylene-glycidyl metatalylate copolymer. Patent Document 5 discloses a crystalline biodegradable resin composition obtained by annealing a composition containing an aliphatic polyester and a modified elastomer. The aliphatic polyester contains polylactic acid, and the modified elastomer contains an acrylic elastomer.

[0007] However, the biodegradable polyester resin composition described in Patent Document 1 is not suitable for biodegradable polyester resins, biodegradable aliphatic monoaromatic polyester resins, and (meth) acrylate esters. It is manufactured by adding an oxide and melt-kneading. In that case, the use of a (meth) acrylic acid ester compound having a functional group such as a glycidinole group causes a hydrogen abstraction reaction and a crosslinking reaction of a polylactic acid resin as a biodegradable polyester resin, resulting in a partially crosslinked product. Is produced and coloration such as yellowing is likely to occur.

[0008] In the compositions of Patent Document 2 and Patent Document 3, a long chain branched polymer is produced by the reaction of a hydroxyl group and a carboxyl group at the terminal of a polylactic acid molecule with an epoxy group-containing polymer. The effect of improving sex is recognized. However, the number of epoxy groups per molecule is too large (for example, Patent Document 2 uses a homopolymer of glycidyl metatalylate, and Patent Document 3 uses 50% glycidyl metatalylate and 50% styrene in Example 3). % Of the copolymer is used), the reaction of the hydroxyl group and carboxyl group at the polylactic acid molecule terminal with the epoxy group is local, and its control is difficult. As a result, the crosslinking reaction proceeds excessively in the molding machine, the resin composition reaches a gelled state, and the discharge becomes unstable. There arises a problem that the surface of the obtained molded body becomes non-uniform. That is, the resin composition has a problem of lacking thermal stability.

[0009] In the polylactic acid resin composition described in Patent Document 4, the amount of the modified olefin compound is 5% by weight or more based on the aliphatic polyester. In the biodegradable resin composition described in Patent Document 5, The blending amount of the acrylic elastomer is 10% by weight or more based on the aliphatic polyester such as polylactic acid. For this reason, although the obtained resin composition is improved in physical properties such as strength and heat resistance, it may cause an excessive crosslinking reaction and may lack molding processability.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-67894

Patent Document 2: JP 2004-10693 A

Patent Document 3: Japanese Patent Laid-Open No. 2003-261756

Patent Document 4: Japanese Patent Laid-Open No. 2001-123055

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2004-35691

Disclosure of the invention

[0010] The present invention has been made in view of the above-mentioned problems, and while suppressing excessive crosslinking reaction, it is possible to improve molding processability by a thickening effect and to exhibit excellent thermal stability. An object is to provide an aliphatic polyester resin composition.

[0011] In one embodiment of the present invention, an aliphatic polyester resin composition is provided. The aliphatic polyester resin composition comprises 0.1 to 1 mass of an acrylic resin modifier (B) to 100 mass parts of an aliphatic polyester resin (A) whose main component is a polymer having a lactic acid unit. It is contained in the ratio of parts. The content of lactide or lactic acid in the aliphatic polyester resin (A) is less than 0.2% by mass. The glass transition temperature of the acrylic resin modifier (B) is 0 ° C or higher, the average number of epoxy groups per molecule is 3 to 30, and the mass average molecular weight is 1,000 to 30,000. It is.

[0012] According to this configuration, the epoxy group of the acrylic resin-based modifier (B) is a fatty acid under the specific requirements of both the aliphatic polyester resin (A) and the acrylic resin-based modifier (B). It can react with a carboxynole group or a hydroxynore group present at the terminal of the group polyester resin (A) to form an appropriate cross-linked structure. [0013] When the aliphatic polyester resin composition is melted and molded, the epoxy group in the acrylic resin modifier (B) is a carboxyl group or hydroxy group at the terminal of the aliphatic polyester resin (A). By reacting with a nore group and crosslinking, the viscosity increases, and a viscosity suitable for molding is developed. Therefore, while suppressing excessive crosslinking reaction, the molding calorie property can be improved by the thickening effect, and excellent thermal stability can be exhibited.

[0014] In an aliphatic polyester resin composition, measured at a temperature of 210 ° C and a load of 21.2 N (2. 16 kgf) in accordance with the thermoplastic flow test method specified in ISO 1133 of the international standard. MFR value (MFR) 5 minutes after the resin was added and 15

Change rate deviation with MFR value (MFR) after 5 minutes MFR: (MFR — MFR) ZMFR)

The value of 15 15 5 5 is preferably from −0.35 to 0.1. According to this configuration, it is possible to improve the molding force resistance with little change in fluidity of the aliphatic polyester resin composition.

[0015] The epoxy equivalent of the acrylic resin-based modified homogeneous lj (B) is preferably 0.70 to 3. OOmeqZg. According to this configuration, the amount of the epoxy group contained in the acrylic resin modifier (B) is determined in consideration of the molecular weight and the average number of epoxy groups per molecule. Therefore, it is possible to easily set the degree of the crosslinking reaction within an appropriate range, and to further exert the above-described effects.

[0016] The acrylic resin modifier (B) is preferably obtained by polymerizing a monomer mixture containing an epoxy group-containing acrylic monomer and a styrene monomer. According to this configuration, a polymer having an epoxy group can be easily obtained as the acrylic resin modifier (B).

[0017] The acrylic resin modifier (B) is preferably produced by a continuous stirred tank polymerization method set to a temperature of 130 to 350 ° C. According to this configuration, it is possible to efficiently produce an acrylic resin-based modifier (B) having a target molecular weight.

[0018] In the aliphatic polyester resin composition, with respect to the melt viscosity measured with a rheometer equipped with a die having a diameter of 1 mm and a length of 10 mm under the conditions of temperature: 200 ° C and shear rate: 121 sec- ¹ Melt viscosity (7) when the acrylic resin modifier (B) is added,

aad Rate of change from melt viscosity (7)) when acrylic resin modifier (B) is not added Δ η

0

The value of (η / η) is preferably from 1.1 to 1.8. According to this configuration, acrylic resin By adding the system modifier (B), the melt viscosity can be increased, and the molding processability can be further improved.

[0019] In the aliphatic polyester resin composition, the swell when the acrylic resin modifier (B) is added (= resin diameter at the die exit / diameter of the die) (DS) and acrylic tree add

Rate of change with Swell (DS) when no fat modifier (B) is added A DS (DS /

0 add

The value of DS) is preferably between 1.05 and 1.3. According to this configuration, the acrylic resin-based modified

0

By adding the material (B), the melt viscosity can be increased, and the molding strength can be further improved.

[0020] The acrylic resin modifier (B) preferably polymerizes a monomer mixture containing an epoxy group-containing acrylic monomer, a styrene monomer, and other vinyl monomers. Obtained. According to this configuration, it is possible to adjust the number of epoxy groups possessed by the acrylic resin modifier, and at the same time, vinyl monomers other than epoxy group-containing acrylic monomers and styrene monomers can be used. Function can be expressed.

[0021] In another aspect of the present invention, there is provided a molded product obtained by melt molding the above aliphatic polyester resin composition. According to this configuration, it is possible to improve the molding processability at the time of molding and to exhibit excellent thermal stability.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail.

[0023] The aliphatic polyester resin composition of the present embodiment (hereinafter simply referred to as the polyester resin composition) is 100 parts by mass of the aliphatic polyester resin (A) (hereinafter simply referred to as the polyester resin (A)). The acrylic resin modifier (B) is contained in a proportion of 0.15 to 1 part by mass. The polyester resin (A) is mainly composed of a polymer having lactic acid units (hereinafter referred to as polylactic acid).

[0024] The polyester resin (A) is a main component of the polyester resin composition, and has a basic function of a molded article obtained by molding the polyester resin composition. The polyester resin (A) mainly composed of polylactic acid is a polyester resin containing 50% by mass or more of a polylactic acid component. That is, if the polyester resin (A) contains 50% by mass or more of a polylactic acid component, the polylactic acid may be homopolylactic acid or other aliphatic polyester unit. Co-polymerized with lactic acid. Further, when the polyester resin (A) contains 50% by mass or more of a polylactic acid component, the polyester resin (A) is a mixture of polylactic acid and another aliphatic polyester not containing the polylactic acid. There may be.

[0025] Polylactic acid is a ring-opening polymerization of lacti K [CH CH (COO) CHCH] or lactic acid [CH CH (

3 2 3 3

OH) (C0OH)]. As this polylactic acid, one synthesized by a conventionally known method can be used. That is, polylactic acid can be produced by direct dehydration condensation from lactic acid described in JP-A-7-33861, JP-A-59-96123, and Polymer Proceedings Proceedings No. 44, pages 3198-3199, or It is synthesized by ring-opening polymerization of lactic acid cyclic dimer lactide.

In the case of direct dehydration condensation, any one of L monolactic acid, D-lactic acid, DL-lactic acid, and a mixture thereof may be used. Also in the case of ring-opening polymerization, any one of L-latatide, D-latactide, DL-lactide, meso-lactide, and a mixture thereof may be used. The synthesis, purification and polymerization operations of lactide are described, for example, in U.S. Pat. No. 4,057,537, published European Patent Application No. 261572, Polymer Bulletin, 1, 4, 491-495 (1985), and Macromol. Chem., 187, 1611—1628 (1986).

[0027] The catalyst used in this polymerization reaction is not particularly limited, and examples thereof include known lactic acid polymerization catalysts, such as tin compounds, powdered tin, tin oxide, zinc powder, halogenated zinc, Zinc oxide, organic zinc compounds, titanium compounds (eg, tetrapropyl titanate), zirconium compounds (eg, zirconium isopropoxide), antimony compounds (eg, antimony trioxide), bismuth compounds (eg, bismuth oxide (ΠΙ ))) And aluminum-based compounds. Examples of tin-based compounds include tin lactate, tin tartrate, dicaprylate, dilaurate, dipalmitate, distearate, dioleate, tin naphthoate, / 3-naphthoate, and An example is tin octoate. Examples of the aluminum compound include aluminum oxide and aluminum isopropoxide. Among these, a catalyst made of tin or a tin compound is particularly preferable because it has excellent activity. For example, in the case of ring-opening polymerization, the amount of these catalysts used is 0.001 to 5% by mass with respect to lactide. Polymerization reaction The reaction is usually performed at a temperature of 100 to 220 ° C. in the presence of the catalyst, although it varies depending on the type of catalyst. It is also preferable that the two-stage polymerization described in JP-A-7-247345 is performed.

[0028] Examples of components other than polylactic acid in the polyester resin (A) include ring-opening polyaddition aliphatic polyesters and polycondensation reaction aliphatic polyesters. Examples of the ring-opening polyaddition aliphatic polyesters include polydaricholic acid, poly (3-hydroxybutyric acid), poly (4-hydroxybutyric acid), poly (4-hydroxyvaleric acid), and polystrength prolatatone. Examples of the polycondensation reaction type aliphatic polyester include polyester carbonate, polyethylene succinate, polybutylene succinate, polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyethylene oxalate, poly Examples include butylene oxalate, polyhexamethylene oxalate, polyethylene sebacate, and polybutylene sebacate.

[0029] The mass (weight) average molecular weight of the polyester resin (A) containing polylactic acid as a main component is a force S of 100,000 or more, preferably S, a force of 120,000 or more, more preferably S, 150, 000 More preferably, it is more preferably 180,000 or more. When the polyester resin has a mass average molecular weight of less than 100,000, the resulting molded article has insufficient mechanical properties such as strength and elastic modulus. As the mass average molecular weight of the polyester resin (A) increases, the above-described physical properties are further improved. The mass average molecular weight of the polyester resin (A) is preferably 400,000 or less because the melt viscosity and melt tension of the polyester resin composition at the time of molding are high.

[0030] The polyester resin (A) containing polylactic acid as a main component contains a small amount of unreacted lactide or lactic acid. Such lactide or lactic acid reacts with the epoxy group of the acrylic resin modifier (B) to inhibit the crosslinking reaction of the polyester resin (A) by the acrylic resin modifier (B). Therefore, the content of lactide or lactic acid in the polyester resin (A) is less than 0.2% by mass, preferably less than 0.15% by mass, and more preferably less than 0.1% by mass. It is particularly preferably less than 0.05% by mass. When the content of lactide or lactic acid is 0.2% by mass or more, the acrylic resin modifier (B) is added to the polyester resin (A) even if the acrylic resin modifier (B) is added. The epoxy group in It is consumed by reacting with lactic acid or lactic acid, and the thickening effect that should be originally obtained is not fully exhibited. For this reason, an excessive amount of the acrylic resin modifier (B) is required, which not only impairs the biodegradability of the polyester resin composition but also increases the production cost. Alternatively, the ring-opening lactide, which is an acid component, works as a reaction aid for the acrylic resin modifier (B), and if the amount is large, the reaction proceeds locally to generate a crosslinked product. Moreover, since the thickening effect cannot be obtained uniformly, there arises a problem that desired physical properties cannot be obtained.

[0031] The constituent molar ratio L / D of L_lactic acid units and D_lactic acid units in polylactic acid may be any of 100/0 to 0/100. In order to obtain a high melting point, polylactic acid preferably contains at least 96 mol% of L-lactic acid and D_lactic acid in order to obtain a high melting point. More preferably, it contains 98 mol% or more of any unit of D-lactic acid. In this case, the polylactic acid may be a copolymer obtained by copolymerizing lactic acid (monomer) or lattide and other components copolymerizable therewith. Examples of other copolymerizable components include dicarboxylic acids having two or more ester bond-forming functional groups, polyhydric alcohols, hydroxycarboxylic acids, ratatones, and various polyesters composed of these various components. Examples include various polyethers and various polycarbonates.

[0032] Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. Examples of the polyhydric alcohol include aromatic polyhydric alcohols (for example, those obtained by adding ethylene oxide to bisphenol, for example), aliphatic polyhydric alcohols, and ether glycols. Examples of the aliphatic polyhydric alcohol include ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, glycerin, sonolebitan, trimethylololepropane, and neopentyldaricol. Examples of ether glycols include diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol.

[0033] Examples of the hydroxycarboxylic acid include glycolic acid, hydroxybutylcarboxylic acid, and those described in JP-A-6-184417. Examples of Lataton include glycolide, ε-force prolataton glycolide, _ε -force prolataton, ε-propiolata Ton, δ-Buchiguchi Rataton, β-Buchiguchi Rataton, γ-Buchiguchi Rataton, Pivalo Rataton, and S-Valerolatataton. The arrangement pattern of the copolymer may be any of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer.

[0034] The acrylic resin modifier (改質) has a function of improving the molding processability and thermal stability of the polyester resin (Α) containing polylactic acid as a main component. In this application, acrylic and methacryl are collectively referred to as (meth) acrylic and clay.

[0035] The glass transition temperature of the acrylic resin modifier (改質) is 0 ° C or higher, preferably 30 ° C or higher, and preferably S is 50 ° C or higher. When the glass transition temperature is less than 0 ° C, the acrylic resin modifier (B) cannot sufficiently exert the thickening effect on the polyester resin (A) during molding of the polyester resin composition, and molding is not possible. It may not be possible to improve workability. The upper limit of this glass transition temperature is usually 100 ° C.

[0036] Acrylic resin modifier (B) The average number of epoxy groups per molecule is 3 to 30, 3.

The power is preferably 5 to 20, and more preferably 4.0 to 10. When the average number of epoxy groups is less than 3, the moldability with a small thickening effect on the polyester resin (A) cannot be sufficiently improved. When the average number of epoxy groups exceeds 30, excessive epoxy groups cause excessive crosslinking reaction with the carboxyl groups or hydroxyl groups of the polyester resin (A), and the molding cacheability deteriorates.

[0037] Acrylic resin modifier (B) The average number of epoxy groups per molecule (hereinafter referred to as Fn) is calculated by the following formula (1).

[0038] Average number of epoxy groups ^ 11) = &) / (100 0)

In the formula (1), a, b and c are defined as follows.

[0039] a represents the ratio (% by mass) of the epoxy group-containing acrylic monomer unit contained in the acrylic resin modifier (B).

[0040] b represents the number average molecular weight of the acrylic resin modifier (B).

[0041] c represents the molecular weight of the epoxy group-containing acrylic monomer.

[0042] The weight average molecular weight of the acrylic resin modifier (B) is 1,000 to 30,000, preferably 1,500 to 20,000, and preferably 2,000 to 15,000. Even more preferred. If this mass average molecular weight is less than 1,000, the acrylic resin modifier (B) Since the average number of poxy groups decreases, the thickening effect on the polyester resin (A) becomes insufficient. If the weight average molecular weight exceeds 30,000, the average number of epoxy groups per molecule of the acrylic resin modifier (B) increases, and the polyester resin (A) undergoes an excessive crosslinking reaction, resulting in moldability. Getting worse. The molecular weight distribution (mass average molecular weight / number average molecular weight) of the acrylic resin modifier (B) is preferably 1.5 to 5.0, more preferably 1.6 to 4.5. Mashi 1. It is more preferable that it is 7 to 4.0.

[0043] The acrylic resin modifier (B) is obtained by polymerization of a monomer mixture containing an epoxy group-containing acrylic monomer and a styrene monomer. The acrylic resin modifier (B) can also be obtained by polymerization of a monomer mixture containing an epoxy group-containing acrylic monomer, a styrene monomer, and other vinyl monomers. . Examples of the epoxy group-containing acryl-based monomers include (meth) acrylic acid glycidyl or (meth) acrylic acid ester having a cyclohexenoxide structure, and (meth) acrylic glycidinoreether. A preferable epoxy group-containing acrylic monomer is (meth) acrylic acid glycidinole having high reactivity. The styrenic monomer has the same properties as the polylactic acid, and thus has an affinity for polylactic acid. Examples of the styrene monomer include styrene and α-methylstyrene.

[0044] Examples of butyl monomers other than epoxy group-containing acrylic monomers and styrene monomers include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid Pill, (meth) butyl acrylate, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid cyclohexyl, stearyl (meth) acrylate, alkyl group having carbon number:! ~ 22 (alkyl group) (Meth) acrylic acid alkyl ester (for example, (meth) acrylic acid methoxyethyl), (meth) acrylic acid polyalkylene glycol ester, (meth) acrylic acid alkoxyalkyl ester , (Meth) acrylic acid hydroxyalkyl esters, (meth) acrylic acid dialkylaminoalkyl esters, (meth) acrylic esters Examples include benzyl laurate, phenoxyalkyl (meth) acrylate, isobornyl (meth) acrylate, and alkoxysilylalkyl (meth) acrylate. Further, (meth) atalinoleamide, (meth) acrylic dialkylamide, buleste can be used as bulur monomers other than epoxy group-containing acrylic monomers and styrene monomers. Aromatic monomers such as butyl acetate, butyl ethers, (meth) aryl ethers, and α-olefin monomers may also be used. Examples of α-olefin monomers include ethylene and propylene. These may be used alone or in combination of two or more.

[0045] The acrylic resin modifier (改質) preferably contains 10 to 40% by mass of an epoxy group-containing acrylic monomer unit and 90 to 20% by mass of a styrene monomer unit. Les. It is more preferable that the acrylic resin modifier (Β) contains 15 to 35% by mass of an epoxy group-containing acrylic monomer unit and 85 to 25% by mass of a styrene monomer unit. Les. It is more preferable that the acrylic resin modifier (含有) contains 20 to 30% by mass of an epoxy group-containing acrylic monomer unit and 80 to 30% by mass of a styrene monomer unit. ,. In these cases, the acrylic resin modifier (改質) does not contain a bull monomer unit other than the epoxy group-containing acrylic monomer unit and the styrene monomer unit, or the acrylic resin modifier. The balance in the agent (ii) is a vinyl monomer unit other than the epoxy group-containing acrylic monomer unit and styrene monomer unit.

[0046] When the proportion of the epoxy group-containing acrylic monomer unit is less than 10% by mass, molding of the polyester resin composition in which the epoxy group in the unit mass of the talyl resin modifier (Β) is scarce In order to sufficiently obtain the effect of improving the strength and thermal stability, it is necessary to add a large amount of the acrylic resin modifier (Β) to the polyester resin (Α). As a result, there arises a problem that the mechanical strength of the molded product obtained from the polyester resin composition is lowered. When the proportion of the epoxy group-containing acrylic monomer unit exceeds 40% by mass, the polyester resin composition becomes excessive due to excessive crosslinking reaction between the polyester resin (Α) and the acrylic resin modifier (Β). In some cases, a crosslinked product is formed, and a molded product having a desired shape cannot be obtained. The styrenic monomer unit and the epoxy monomer-containing acrylic monomer unit and the vinyl monomer unit other than the styrenic monomer unit are the above after the ratio of the acrylic monomer unit is set. Within this range, it is set as appropriate in consideration of the mechanical strength of the molded product.

[0047] The acrylic resin modifier (i) can be produced by any method such as a bulk polymerization method, a solution polymerization method, and an emulsion polymerization method. The preferred polymerization method is a continuous stirred tank polymerization method, more preferred. A new polymerization method is a high temperature continuous stirred tank polymerization method. In this case, the polymerization temperature is preferably from 130 to 350 ° C, more preferably from 150 to 330 ° C, even more preferably from 170 to 270 ° C. At the above polymerization temperature, a polymer having a desired molecular weight (including a copolymer) can be efficiently obtained by using a radical polymerization initiator and a chain transfer agent, or by using a very small amount. When the polymerization temperature is less than 130 ° C, a large amount of radical polymerization initiator and chain transfer agent are required to obtain a polymer having the desired molecular weight. Therefore, impurities are present in the obtained polymer. Many are easy to include. For this reason, problems such as coloring and off-flavor may occur in the polyester resin composition and the molded body. When the polymerization temperature exceeds 350 ° C, the polymer may be thermally decomposed and the target polymer may not be obtained.

[0048] Such a high-temperature continuous stirring tank polymerization method is, for example, a known polymerization method disclosed in JP-T-57-502171, JP-A-59-6207, and JP-A-60-215007. It is done by. For example, after a pressurizable reactor is set to a predetermined temperature under pressure, each of the bull monomers and, if necessary, a vinyl monomer mixture composed of a polymerization solvent is added to the reactor at a constant supply rate. A method is adopted in which a polymerization reaction liquid is supplied from the reactor in an amount commensurate with the supply amount of the bull monomer mixture. Moreover, a polymerization initiator may be mix | blended with a vinyl-type monomer mixture as needed. The blending amount of the polymerization initiator is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the vinyl monomer mixture. The pressure depends on the reaction temperature and the boiling point of the butyl monomer used and the polymerization solvent, and does not affect the reaction. Therefore, the pressure should be sufficient to maintain the reaction temperature. Good. The residence time of the monomer mixture in the reactor is preferably 1 to 60 minutes. If the residence time is less than 1 minute, the monomer may not sufficiently react, and if the residence time exceeds 60 minutes, productivity tends to decrease. The preferred residence time is 2 to 40 minutes.

[0049] Such a high-temperature continuous stirring tank polymerization method can maintain the composition in the polymerization tank in a uniform state as compared with the batch polymerization method and the semi-batch polymerization method. Distribution is uniform. Therefore, the acrylic resin modifier (B) has a more uniform number of epoxy groups per molecule and molecular weight distribution, and is suitable for the purpose. In addition, high temperature The continuous polymerization method has an advantage that a desired acrylic resin modifier (B) can be obtained by a short polymerization operation, and is economical and hardly causes gelation by a crosslinking reaction.

[0050] The acrylic resin modifier (B) is a temperature measured according to the flow test method for thermoplastics specified in ISO 1133 (International Standard 3-1 ^ 7 210). : It is preferable that the MFR value at 210 ° C and load: 21.2N (2.16kgf) shows the specified value. That is, the change between the MFR value (MFR) after 5 minutes and the MFR value (MFR) after 15 minutes.

5 15 The conversion rate deviation (a MFR: (MFR -MFR) / MFR) should be _0.35 to 0.1

15 5 5

It is more preferable that -0.2 to 0.05.

[0051] When the change rate deviation of the MFR value is less than 0, it means that the viscosity of the sample increases with time. That is, the reaction between the resin and the acrylic resin modifier (B) was not completed during the mixing and kneading, and the reaction further progressed during the subsequent molding cage. When the change rate deviation of the MFR value is less than -0.35, the reaction between the polyester resin (A) and the acrylic resin modifier (B) proceeds excessively during the molding process, increasing more than necessary. Because of stickiness, fish eyes and disappearance may occur on the surface of the resulting molded article, which may reduce the design. When the deviation rate deviation of the MFR value exceeds 0.1, it means that the viscosity of the sample decreases with time. In this case, the viscosity of the resin is greatly reduced due to a long stay during the molding process, and drawdown occurs, making it difficult to obtain a molded body having a desired shape.

[0052] The epoxy equivalent (hereinafter referred to as EV) of the acrylic resin-based modified homogeneous IJ (B) has a power of 0.70 to 3.00 meq / g. S is preferably 1.06 to 2.46 meq / g. The power of g is more preferable than S, and more preferably 1.40 to 2. l lmeq / g. When this epoxy equivalent is less than 0.70 meq / g, a large amount of acrylic resin modifier (B) is added to the polyester resin (A) in order to sufficiently obtain the moldability and thermal stability of the polyester resin composition. It is necessary to add. As a result, there arises a problem that the mechanical strength of the molded product obtained from the polyester resin composition is lowered. When the epoxy equivalent exceeds 3.00 meq / g, the polyester resin composition becomes, for example, due to excessive crosslinking reaction between the carboxyl group or hydroxyl group of the polyester resin (A) and the epoxy group of the acrylic resin modifier (B). An excessive cross-linked state is caused in the molding machine, and a molded product having a desired shape cannot be obtained by surging or the like. There is a case.

[0053] The addition amount of the acrylic resin modifier (B) is 0.11 to 1 part by mass, and 0.2 to 0.8 part by mass with respect to 100 parts by mass of the polyester resin (A). Is more preferably 0.3 to 0.6 parts by mass. When the amount of the acrylic resin-based modifier (B) added is less than 0.15 parts by mass, the excellent thermal stability and molding cacheability of the polyester resin composition which is poor in the modification effect cannot be obtained. When the amount of the acrylic resin modifier (B) exceeds 1 part by mass, the polyester resin composition is excellent in thermal stability, but the crosslinking reaction proceeds during the molding process, leading to an excessive crosslinking state. Therefore, molding becomes difficult.

[0054] The method of mixing the acrylic resin-based modifier (B) into the polyester resin (A) and blending various additives may be carried out by a conventionally known method without particular limitations. For example, powder or pellets of polyester resin (A) and each component of the additive may be mixed by dry blending, or a part of the additive may be preblended and other components may be dry blended later. Good. For example, each component is mixed using a mill roll, a Banbury mixer, or a super mixer, and then kneaded using a single screw or twin screw extruder. This mixing and kneading is usually performed at a temperature of 120 to 220 ° C.

[0055] The mixing temperature of the polyester resin (A) and the acrylic resin modifier (B) is preferably 180 to 230 ° C. When the mixing temperature is less than 180 ° C, the reaction between the polyester resin (A) and the allyl resin modifier (B) proceeds slowly, so that the reaction takes time, and productivity and equipment are limited. The When the mixing temperature exceeds 230 ° C, depolymerization of the polyester resin (A) occurs at the same time, and the viscosity of the polyester resin (A) component in the final polyester resin composition becomes shorter and the viscosity decreases. Happens. When the polyester resin (A) and the acrylic resin-based modifier (B) are mixed under this temperature condition, it is preferable that the residence time is 2 minutes or more 3 to: 15 minutes. 3 to 10 minutes is more preferable. If the residence time is less than 2 minutes, sufficient reaction time cannot be secured, and unreacted substances remain and the reaction proceeds during the molding process. If the residence time exceeds 15 minutes, there is a concern that the polyester resin (A) will suffer heat degradation and depolymerization if the productivity decreases. Furthermore, an additive may be added in the polymerization step for obtaining the polyester resin (A). In addition, for example, a master batch containing a high concentration of additives is produced. A method in which this is added to the polyester resin (A) can also be employed.

[0056] For the polyester resin composition, conventionally known plasticizers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, colorants, various fillers, antistatic agents, release agents, if necessary. Various additives such as agents, fragrances, lubricants, flame retardants, foaming agents, fillers, antibacterial agents'antifungal agents, and other nucleating agents may be blended. In particular, in order to improve the molding processability, it is preferable that an aliphatic amide compound, an aromatic amide compound, talc or the like, which is a known crystal nucleating agent, is blended.

[0057] The polyester resin composition is a rheometer equipped with a die having a diameter of 1 mm and a length of 10 mm, specifically a capillary rheometer (Capillograph 1C, manufactured by Toyo Seiki Co., Ltd.), temperature: 200 °. Regarding the melt viscosity measured under the condition of C and shear rate: 121se _C — ¹ , the following conditions are preferably satisfied. That is, the melt viscosity when the acrylic resin modifier (B) is added) and the melt viscosity when the acrylic resin modifier (B) is not added (add

77) The rate of change Δη (η / η) is preferably 1.1 to:! This strange

0 add 0

When the conversion rate Δ 77 is less than 1.1, the thickening effect is small. The effect of improving the desired molding cacheability is insufficient. On the other hand, if the rate of change Δ exceeds 1.8, the viscosity will increase excessively during the molding process, making it difficult to obtain the desired molded product.

[0058] In addition, when the acrylic resin modifier (Β) is added, the swell (= resin diameter / die diameter at the die outlet) (DS) and the acrylic resin modifier (Β) are added. Not add

The rate of change A DS (DS / DS) with Swell (DS) at the time is 1 · 05〜: L 3

0 add 0

It is preferable. When the change rate A DS is less than 1.05, sufficient processability cannot be exhibited, which is insufficient for thickening effect. On the other hand, when the rate of change A DS exceeds 1.3, the increase in viscosity during the molding process becomes excessively large, making it difficult to obtain a molded product having a desired shape. Therefore, it is particularly preferable that the conditions of the change rate Δη of the melt viscosity and the change rate ADS of the swell are both satisfied.

[0059] The molding method of the polyester resin composition is not limited to an extrusion molding method of a film, a sheet or the like, but in the same manner as a general plastic, an injection molding method, a blow molding method, a vacuum molding method, a compression molding method, etc. A molding method may be employed. And various molded objects, such as a film molded object, a sheet molded object, a fiber, a foam molded object, a blow molded object, are obtained. Polyester resin set The composition is also suitable for molding foams and the like that require particularly high melt strength and melt tension.

[0060] The polyester resin composition is obtained by blending the acrylic resin modifier (B) at a ratio of 0.15 to 1 part by mass with respect to 100 parts by mass of the polyester resin (A) described above. It is done. In the case of producing a molded body using the obtained polyester resin composition, the polyester resin composition is heated and melted and molded according to a molding method such as an injection molding method to produce a molded body having a desired shape. Is done.

[0061] In this molding process, the epoxy group contained in the acrylic resin modifier (B) reacts with a carboxyl group or a hydroxyl group present at the terminal of polylactic acid which is the main component of the polyester resin (A). As a result, the crosslinking reaction proceeds. At this time, since the content of latatin or lactic acid in the polyester resin (A) is limited to less than 0.2% by mass, the epoxy group in the acrylic resin-based modifier (B) is a carboxynole of polylactic acid. Can react effectively with groups or hydroxyl groups. At the same time, the average number of epoxy groups per molecule of the acrylic resin modifier (B) is limited to 3-30, and the mass average molecular weight is set in the range of 1,000-30,000. , Excessive progress of the crosslinking reaction is suppressed. Therefore, an appropriate thickening can be obtained during molding, and the molding can proceed smoothly to produce a molded product having good appearance and physical properties.

[0062] This embodiment has the following advantages.

[0063] The polyester resin composition of the present embodiment contains 0.1-15 parts by mass of the acrylic resin modifier (B) with respect to 100 parts by mass of the polyester resin (A). Polyester resin (A) is mainly composed of polylactic acid, and the content of lactide or lactic acid is less than 0.2% by mass. On the other hand, the glass transition temperature of the acrylic resin modifier (B) is 0 ° C or higher, the average number of epoxy groups per molecule of the acrylate resin modifier (B) is 3 to 30, and The mass average molecular weight of the talyl resin modifier (B) is 1,000-30,000. For this reason, the epoxy group of the acrylic resin modifier (B) reacts with the carboxyl group or hydroxyl group of the polylactic acid terminal to form an appropriate crosslinked structure.

[0064] When the polyester resin composition is molded by heating, the viscosity increases due to the crosslinking reaction, and a viscosity suitable for molding is obtained. Therefore, while suppressing excessive cross-linking reaction, it is possible to improve the molding strength due to the thickening effect, and excellent thermal stability. Qualitative can be demonstrated.

Further, the polyester resin composition has a change rate deviation (σ MFR) value of −0.35-0.

By setting it to 1, it is possible to improve the molding processability with little change in fluidity even when the heating residence time is long.

[0066] Furthermore, the amount of epoxy groups contained in the acrylic resin modifier (B) is set by setting the epoxy equivalent of the acrylic resin modifier (Β) to 0.70-3.00 meq / g. But with molecular weight

Determined by taking into account the average number of epoxy groups per molecule. Therefore, the degree of the crosslinking reaction can be suppressed within an appropriate range.

[0067] Further, since the acrylic resin modifier (B) is obtained by polymerizing a monomer mixture containing an epoxy group-containing acrylic monomer and a styrene monomer, an acrylic resin-based modifier is obtained. A polymer having an epoxy group can be easily obtained as the modifying agent (B).

[0068] In addition, the acrylic resin-based modifier (B) is produced by a continuous stirred tank polymerization method set at a temperature of 130 to 350 ° C, so that the acrylic resin-based modifier having a target molecular weight is modified. It is possible to manufacture the quality agent efficiently.

[0069] In addition, the value of the change rate Δ 77 (77 / τ 7) of the melt viscosity (77) is set to 1 · 1 to:! · 8

0 add 0

And the change rate of force swell (DS) A DS (DS / DS) is set to 1 · 05 ~: L 3

0 add 0

Can be done. For this reason, the addition of the acrylic resin modifier (B) can increase the melt viscosity and can further improve the molding strength.

[0070] As described above, the temperature dependence of the melt viscosity of the polyester resin composition can be reduced, and the viscosity change can be maintained even during long-time residence at the molding processing temperature, which can only improve the molding processability. Can be kept within a certain range. As a result, a molded article having an appearance and mechanical properties superior to conventional ones can be produced by melt-molding the polyester resin composition.

Example

[0071] The embodiment will be described more specifically with reference to production examples and examples. However, the present invention is not limited to these examples. In each of the following examples, the pellet was immersed in acetonitrile for 12 hours, and the extracted measurement specimen was measured with a high-performance liquid chromatograph, and the obtained results were obtained using a lactide calibration curve or a lactic acid calibration curve prepared in advance. The content of lactide or lactic acid was analyzed by calculation. The weight average molecular weight (Mw) of the polymer is a polystyrene conversion value by gel permeation chromatography (GPC) analysis, and the glass transition temperature and melting point are determined by a scanning differential calorimeter (DSC) at a rate of temperature increase of 10 ° C. It is a value measured in / min.

[0072] The average number (Fn) of epoxy groups per molecule of the acrylic resin modifier (B) was calculated from the above-described formula (1). The epoxy equivalent (EV) was measured according to ASTM D-1652-73.

[0073] Various acrylic resin-based modifiers were produced in advance by the following method.

(Production Example 1, production of acrylic polymer 1)

The oil jacket temperature of a 1 liter pressurized stirred tank reactor equipped with an oil jacket was maintained at 200 ° C. On the other hand, 74 parts by mass of styrene (hereinafter referred to as St), 20 parts by mass of glycidyl methacrylate (hereinafter referred to as GMA), 6 parts by mass of butyl acrylate (hereinafter referred to as BA), 15 parts by mass of xylene, and initiation of polymerization A monomer mixture consisting of 0.5 parts by mass of ditertiary butyl peroxide (hereinafter referred to as DTBP) was charged into the raw material tank as an agent. The monomer mixture is continuously supplied from the raw material tank to the reactor at a constant supply rate (48 g / min, residence time: 12 minutes), and the reaction liquid is kept constant at approximately 580 g. Was continuously extracted from the outlet of the reactor. At that time, the internal temperature of the reactor was kept at about 210 ° C.

[0074] After 36 minutes had passed since the temperature inside the reactor was stabilized, the extracted reaction solution was continuously subjected to volatile component removal treatment by a thin film evaporator maintained at a reduced pressure of 3 OkPa and a temperature of 250 ° C. Polymer 1 containing almost no volatile component was recovered. About 7 kg of Polymer 1 was collected over 180 minutes.

(Production Example 2, production of acrylic polymer 2)

Other than using a monomer mixture consisting of St 38 parts by mass, BA 8 parts by mass, GMA 25 parts by mass, methyl metatalylate (hereinafter referred to as MMA) 29 parts by mass, xylene 15 parts by mass, and DTBP 0.3 parts by mass Produced polymer 2 in the same manner as polymer 1 was produced.

(Production Example 3, production of acrylic polymer 3)

A polymer 3 was produced by the same production method as that for the polymer 1 except that the composition of the raw material monomer was as shown in Table 1. (Production Examples 4-7, production of acrylic polymers 4-7)

Polymers 4 to 7 were produced by the same production method as that for polymer 1 except that the composition of the raw material monomers and the polymerization temperature were as shown in Table 1.

[table 1]

The following two types of polylactic acid resin were used. Each molecular weight shown below is a polystyrene conversion value by GPC method, and Tg is by DSC. The lactide content is a result measured by liquid chromatography according to the above method.

[0076] Polylactic acid resin B_2 (hereinafter referred to as PLA1) manufactured by Toyota Motor Corporation

Mw = 123, 000, Mn = 56, 400, Mw / Mn = 2.18,

Tg = 59.7 ° C, lactide content = 970ppm (0.097 mass%)

Polylactic acid resin # 5000 (hereinafter referred to as PLA2) manufactured by Toyota Motor Corporation

Mw = 224, 000, Mn = 98, 700, Mw / Mn = 2.27,

Tg = 60. 7 ° C, lactide, content = 2, 500ppm (0. 25 mass ^_0/0)

(Examples 1-7 and comparative examples:! -12, compound and moldability test)

After blending various polylactic acid resins and mixed aliphatic polyester resins with the acrylic resin modifier (B) so as to have the addition amounts shown in Table 2, each component is uniformly premixed with a Henschel mixer, It was melt kneaded at 200 ° C. in a parallel twin screw extruder (ST-40, manufactured by Plastics Engineering Laboratory).

[0077] [Table 2]

* Epoxy soy bean oil: Asahi Denka Kogyo Co., Ltd. Ade force sizer O-130P

Denacol EX-313: Polyglycidyl etherate manufactured by Nagase ChemteX Corporation

GS-Pla: Aliphatic polyester resin (polybutylene succinate) “G” manufactured by Mitsubishi Chemical Corporation

S-pla AZ71T "

AO-50: Phenolic antioxidant manufactured by Asahi Denka Kogyo Co., Ltd .: “ADK STAB A〇-50” MA— P6: Fine talc manufactured by Nippon Talc Co., Ltd .: “MICR〇 ACE P_6”

WX-1: JI Ken Fine Chemical Co., Ltd. Bisamide lubricant: “WX_ 1”

LA-1: Nisshinbo Carpositimide Stabilizer: “LA_ 1”

(Compound viscosity change and thickening effect evaluation)

Next, for the obtained compound, the temperature was 210 ° C and the load was 21.2N (2.) In accordance with the flow test method for thermoplastics of ISO 1133 (JIS Industrial Standard JIS-K7210). The MFR value at 16 kgf) was measured. The MFR value (MFR) at 5 minutes after the resin was added and the MFR value (MFR) at 15 minutes were measured.

5 15

[0078] Further, using a capillary rheometer (Capillograph 1C manufactured by Toyo Seiki Co., Ltd.) equipped with a die having a diameter of 1 mm and a length of 10 mm, melting at a temperature of 200 ° C and a shearing measure of 121 sec- ¹ The viscosity was measured. The diameter of each sample discharged from the capillary rheometer die was measured, and the swell was measured by comparison with the die diameter (calculated from swell = diameter of discharge sample (mm) / die diameter (mm)). The results are shown in Table 3.

[0079] [Table 3]

MFR ₅ MFR ₁₅ Melt viscosity η Swell DS

Appearance

(g / 10 min) (g / 10 min) (Pa-s) (1)

Example 1 Good 8.2 6.7 1070 1.22 Example 2 Good 6.7 5.0 1270 1.31 Example 3 Good 5.0 3.3 1200 1.42 Example 4 Good 9.7 10.2 1205 1.20 Example 5 Good 7.5 5.8 1 170 1.24 Example 6 Good 13.1 11.4 622 1.58 Example Example 7 Good 7.3 7.5 722 170 Comparative Example 1 Good 1 1.4 15.8 929 1.14 Comparative Example 2 Good 2.9 10.1 1943 1.49 Comparative Example 3 Gelation 3.2 1.5 1640 1 J6 Comparative Example 4 Good 10.7 1 1.0 974 1.15 Comparative Example 5 Good 1 1.0 1 1.8 996 1.15 Comparative Example 6 Good 10.4 10.3 1 1 10 1.15 Comparative Example 7 Good 15.0 26.5 795 1.15 Comparative Example 8 Good 15.2 36.7 709 1.12 Comparative Example 9 Good 10.4 1 1.6 1090 1.18 Comparative Example 10 Gelation 6.7 4.3 1318 1.25 Comparative Example 1 1 Good 1.0 1.3 2440 1.56 Comparative Example 12 Good 17.1 21.3 417 1.39

As shown in Examples 1 to 5 in Table 3, the appearance of various PLA compounds to which polymers 1 to 3 were added was good, and those PLA compounds were compared with the PLA resin of Comparative Example 1. A sufficient thickening effect was confirmed. Furthermore, in Examples 6 and 7 in which two types of aliphatic polyesters were mixed, the thickening effect due to the addition of the acrylic resin modifier (B) was sufficiently confirmed as compared with Comparative Example 12, and various additions were made. Even when the agent was included, the thickening effect was not inhibited.

[0080] Based on the results in Table 3, change rate deviation MFR: (MFR _MFR) ZMFR)

15 5 5 The melt viscosity change rate Δη was calculated from the melt viscosity measurement result, and the swell change rate ΔDS value was calculated from the swell measurement result. Table 4 shows the results.

[0081] [Table 4] Test a MFR η Remarks Example 1 -0.18 1.15 1.07 A η and DS are calculated based on the value of standard 1 Example 2 -0.26 1.37 1.15 Δ η and DS are calculated based on the value of standard 1 Example 3 -0.34 1.29 1.25 AV and DS are calculated based on the value of standard 1 Example 4 0.05 1.30 1.05 Δ η, lDS is calculated based on the value of standard 1 Example 5 -0.23 1.26 1.09 Δ Ό, lDS is standard Example 6 -0.13 1.49 1.14 A η, IDS is calculated based on the standard 3 value Example 7 0.04 1.70 1.19 Δ 7}, DS is calculated based on the standard 3 value Comparative Example 1 0.39 1.00 1.00 Standard 1

Comparative Example 2 2.51 1.00 1.00 Standard 2

Comparative Example 3 -0.53 1.77 1.54 Δ η, lDS is calculated based on the value of Reference 1 Comparative Example 4 0.03 1.05 1.01 A η, DS is calculated based on the value of Reference 1 Comparative Example 5 0.08 1.07 1.01 Δ η, DS is calculated based on the value of standard 1.Comparative example 6 1 0.01 1.20 1.01 Δ Π, is calculated based on the value of standard 1 Comparative example 7 0.77 0.86 1.01 A η, DS is based on the value of standard 1 Calculation Comparative Example 8 1.41 0.76 0.98 A η, DS is calculated based on the value of Standard 1. Comparative Example 9 0.12 1.17 1.04 An. DS is calculated based on the value of Standard ^1. Comparative Example 10 -0.36 1.42 1.10 Δ η , DS is calculated based on the value of Standard 1 Comparative Example 11 0.36 1.26 1.05 A η, lDS is calculated based on the value of Standard 2 Comparative Example 12 0.25 1, 00 1.00 Standard 3

(Effects of lactide content in polylactic acid resin)

When the value of the change in melt viscosity of Example 1 was compared with the value of the change in melt viscosity of Comparative Example 11 in which a polylactic acid resin having a high lactide content was used, the addition of polymer 1 as an acrylic resin modifier was added. Despite the same amount and compounding conditions, the thickening effect of the viscosity change value of Example 1 was higher than that of Comparative Example 11.

(Effects of acrylic resin modifiers)

From Comparative Example 3, when Polymer 4 having a large epoxy group equivalent was used, a bridge reaction occurred in the extruder, and the melt was gelled, so that stable extrusion could not be achieved. Furthermore, from Comparative Examples 4 to 6, when polymers 5 to 7 having a Tg of 0 ° C. or lower were used, the extrusion moldability and the viscosity change by MFR measurement were good, but the melt viscosity change rate Δ From the results of η and swell change rate ADS, sufficient thickening was not recognized. In the results of Comparative Examples 7 and 8 where epoxidized soybean oil and polyglycidyl ether were added, the reactivity was poor. As it was sufficient, the effect of improving the viscosity change by MFR measurement was low, and no increase in melt viscosity was observed.

(Effects of added amount of acrylic resin modifier)

From the results of Example 1, Example 4 and Example 5, the appearance of the PLA compound was good and a sufficient thickening effect as a PLA resin was confirmed. However, the amount of the acrylic resin-based modifier added was small. In Comparative Example 9 with a small amount, a sufficient thickening effect was not confirmed based on the values of Δ and ADS. On the other hand, in Comparative Example 10 in which the acrylic resin modifier was excessively added, a crosslinking reaction occurred in the extruder, the melt reached gelation, and a stable extrusion could not be achieved. However, it was confirmed that the reaction proceeds excessively and the viscosity change of MFR measurement is large, so that the thermal stability during molding calorie is lacking.

[0082] The embodiment described above can be embodied with the following modifications.

[0083] In addition to the acrylic resin-based modifier (B), a compound that reacts with the hydroxyl group or carboxynole group of polylactic acid may be added to the polyester resin composition. Examples of this compound include acid anhydrides, alkoxy compounds, and amide group-containing compounds.

[0084] An aromatic polyester resin may be added to the polyester resin composition in order to improve the mechanical strength and heat resistance of the molded body.

[0085] In order to accelerate the crosslinking reaction of the polyester resin composition, a small amount of an epoxy compound such as bisphenol A may be blended in the polyester resin composition.

Claims

The scope of the claims

[1] Aliphatic polyester resin (A) comprising a polymer having a lactic acid unit as a main component and a lactide or lactic acid content of less than 0.2% by mass (A) with respect to 100 parts by mass, Acrylic resin-based modifier (B) having an average number of epoxy groups per molecule of 3 to 30 and a mass average molecular weight of 1,000 to 30,000 is 0.15 ° C. ~ :! An aliphatic polyester resin composition characterized by containing at a ratio of parts by mass.

[2] MFR value at a temperature of 210 ° C and a load of 21.2 N (2. 16 kgf) measured according to the thermoplastic flow test method specified in ISO 1133 of the international standard. Deviation in the rate of change between the MFR value (MFR) after 5 minutes and the MFR value (MFR) after 15 minutes

5 15

(a MFR: (MFR —MFR) / MFR) is a value between 0 · 35 and 0.1.

15 5 5

The aliphatic polyester resin composition according to claim 1.

[3] The aliphatic polyester resin composition according to claim 1 or 2, wherein an epoxy equivalent of the acrylic resin-based modifier (であ) is 0 · 70-3.00 meq / g.

[4] The acrylic resin modifier (B) is obtained by polymerizing a monomer mixture containing an epoxy group-containing acrylic monomer and a styrene monomer. The aliphatic polyester resin composition according to claim 3.

[5] The acrylic resin-based modifier (B) is produced by a continuous stirred tank polymerization method set at a temperature of 130 to 350 ° C. The aliphatic polyester resin composition described in 1.

[6] Acrylic resin modifier for melt viscosity measured with a rheometer equipped with a die of diameter: lmm and length: 10mm, temperature: 200 ° C and _shear rate: 121 _SeC — ¹ ( When B) is added, the melt viscosity () and acrylic resin modifier (B) are added.

The rate of change from the melt viscosity () when there is no Δ η (η / η) is 1.:!~1.8

0 add 0

The aliphatic polyester resin composition according to any one of claims 1 to 5, wherein:

[7] Swell when the acrylic resin modifier (B) is added (= resin diameter / die diameter at the die exit) (DS) and acrylic resin modifier (B) Add

Rate of change with Sueñore (DS) A DS (DS / DS) has a value of 1 · 05〜: 1. 3 The aliphatic polyester resin composition according to any one of claims 1 to 5.

[8] It is obtained by polymerizing a monomer mixture containing an acrylic resin modifier (B), an epoxy group-containing acrylic monomer, a styrene monomer, and other vinyl monomers. The aliphatic polyester resin composition according to any one of claims 4 to 7, characterized by:

[9] A molded article obtained by melt-molding the aliphatic polyester resin composition according to any one of claims 1 to 8.