Resin composition

Abstract

To provide a resin composition with superior impact resistance.SOLUTION: A resin composition contains: a β-methyl-δ-valerolactone-based polymer, represented by general formula (I-a) or (I-b); and a 3-hydroxyalkanoate-based polymer, represented by general formula (II).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition containing a β-methyl-δ-valerolactone polymer and a 3-hydroxyalkanoate polymer. [Background technology]

[0002] From the viewpoint of global environmental conservation, there is a demand in a wide range of fields for reducing the environmental impact of plastic materials used in products. In order to reduce the environmental impact, plastic materials using 3-hydroxyalkanoate polymers, which are one type of "biodegradable plastics," have been developed. However, molded articles made of 3-hydroxyalkanoate polymers tend to be brittle and inferior in flexibility and impact resistance compared to petroleum-based plastics, and their use as resin materials may be limited.

[0003] For example, a technology has been disclosed relating to a resin composition containing a 3-hydroxyalkanoate polymer having a 3-hydroxybutyrate ratio of 80 mol % or more and a polycaprolactone resin (PCL) (Patent Document 1). Patent Document 1 describes that by mixing a 3-hydroxyalkanoate polymer with PCL, the tensile elongation and tear strength are improved compared to those of the 3-hydroxyalkanoate polymer alone. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-222791 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the resin composition described in Patent Document 1 has improved impact resistance compared to a composition containing a 3-hydroxyalkanoate polymer alone, the impact resistance is not fully satisfactory. Therefore, an object of the present invention is to provide a resin composition having good impact resistance. [Means for solving the problem]

[0006] As a result of intensive research aimed at solving the above problems, the present inventors have conceived the following invention and found that the problems can be solved. That is, the present invention is as follows.

[0007] [1] A resin composition comprising a β-methyl-δ-valerolactone polymer represented by the following general formula (Ia) or (Ib) and a 3-hydroxyalkanoate polymer represented by the following general formula (II): [ka] [In general formula (Ia), n is 5 to 20. In general formula (Ib), l and m are each independently 2 to 10. [ka] [In general formula (II), The ratio of k to p (k / p) is 70 / 30 to 99 / 1. [2] The resin composition according to [1] above, containing 5 parts by mass or more and 20 parts by mass or less of the β-methyl-δ-valerolactone polymer per 100 parts by mass of the 3-hydroxyalkanoate polymer. [3] The resin composition according to the above [1] or [2], wherein the β-methyl-δ-valerolactone polymer has a number average molecular weight of 1,000 to 4,000. [4] The resin composition according to any one of the above [1] to [3], wherein the 3-hydroxyalkanoate polymer has a weight average molecular weight of 50,000 to 3,000,000. [5] The resin composition according to any one of the above [1] to [4], wherein the β-methyl-δ-valerolactone polymer is represented by the above general formula (Ia). [6] The resin composition according to any one of the above [1] to [4], wherein the β-methyl-δ-valerolactone polymer is represented by the above general formula (Ib). Effect of the Invention

[0008] According to the present invention, it is possible to provide a resin composition having good impact resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the present invention will be described based on an example of an embodiment. However, the embodiment shown below is an example for embodying the technical idea of ​​the present invention, and the present invention is not limited to the following description. In addition, in this specification, preferred embodiments are shown, but a combination of two or more of the individual preferred embodiments is also a preferred embodiment. When there are several numerical ranges for matters shown as numerical ranges, the lower limit and upper limit can be selectively combined to form a preferred embodiment. In this specification, when a numerical range is stated as "XX to YY", it means "not less than XX and not more than YY".

[0010] <Resin composition> The resin composition of the present embodiment contains a β-methyl-δ-valerolactone polymer represented by general formula (Ia) or (Ib) and a 3-hydroxyalkanoate polymer containing a structure represented by general formula (II). By containing a β-methyl-δ-valerolactone polymer represented by general formula (Ia) or (Ib) and a 3-hydroxyalkanoate polymer containing a structure represented by general formula (II), the resin composition has good impact resistance.

[0011] [β-Methyl-δ-valerolactone polymer] The β-methyl-δ-valerolactone polymer of the present embodiment is represented by the following general formula (Ia) or (Ib).

[0012] [ka]

[0013] 〈n, m, l〉 In formulae (Ia) and (Ib), n, m, and l each represent the average number of repetitions. n is an integer of 5 to 20, preferably 5 to 18, and more preferably 5 to 15. m is an integer of 2 to 10, preferably an integer of 2 to 9, and more preferably an integer of 2 to 7. 1 is an integer of 2 to 10. It is preferably an integer of 2 to 9, and more preferably an integer of 2 to 7. In this specification, "n, m, and l" are 1 The ratio of the integrated proton number of the initiator structure to the integrated proton number of the repeating unit structure was determined by H-NMR measurement. The detailed measurement method can be according to the method described in the Examples.

[0014] <Number average molecular weight (Mn)> The number average molecular weight of the β-methyl-δ-valerolactone polymer is preferably 1,000 to 4,000, more preferably 1,500 to 3,000, and even more preferably 1,800 to 2,500. When the number average molecular weight of the β-methyl-δ-valerolactone polymer is within the above numerical range, the viscosity of the resin composition does not become too low, and the handling property and productivity during molding become good. All "number average molecular weights" described in this specification are number average molecular weights calculated using standard polystyrene standards and measured by gel permeation chromatography (GPC). For detailed measurement methods, the methods described in the Examples can be used.

[0015] <Weight average molecular weight (Mw)> The weight average molecular weight of the β-methyl-δ-valerolactone polymer is preferably 1,500 to 8,000, more preferably 1,500 to 6,000, and even more preferably 2,000 to 5,000. When the weight average molecular weight of the β-methyl-δ-valerolactone polymer is within the above numerical range, the viscosity of the resin composition does not become too low, and the handling property and productivity during molding become good. The "weight average molecular weight" described in this specification is a weight average molecular weight calculated as standard polystyrene by gel permeation chromatography (GPC). The detailed measurement method can be according to the method described in the Examples.

[0016] <Molecular weight distribution (Mw / Mn)> The molecular weight distribution (Mw / Mn) of the β-methyl-δ-valerolactone polymer is preferably 1.0 to 3.0, more preferably 1.1 to 2.0, and further preferably 1.2 to 1.8. All "molecular weight distributions" described in this specification are values ​​calculated from the number average molecular weight and weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography (GPC). The detailed method for measuring the number average molecular weight and weight average molecular weight can be according to the method described in the Examples.

[0017] In one embodiment of the present invention, the β-methyl-δ-valerolactone-based polymer is preferably represented by general formula (Ia). In another embodiment of the present invention, the β-methyl-δ-valerolactone-based polymer is preferably represented by general formula (Ib).

[0018] <Manufacturing method> The β-methyl-δ-valerolactone polymer of this embodiment is preferably produced by a method including a step of adding a terminal modification agent to a reaction solution obtained by reacting β-methyl-δ-valerolactone, an alcohol compound, and a base catalyst to carry out a terminal modification reaction (hereinafter also referred to as the "reaction step"). The above production method is characterized in that a terminal modifier is added directly to a reaction solution obtained by reacting β-methyl-δ-valerolactone, an alcohol compound, and a base catalyst. That is, after ring-opening polymerization of β-methyl-δ-valerolactone, the terminals of the ring-opened polymer can be modified by adding a terminal modifier to the reactor in which the ring-opening polymerization was carried out, without taking out the ring-opened polymer once. Since the reaction process involves ring-opening polymerization reaction and terminal modification reaction in one pot, the above production method can be said to be a simplified process. The β-methyl-δ-valerolactone polymer of this embodiment is not limited to being produced by the above-mentioned production method.

[0019] (Alcohol compounds) The alcohol compounds that can be used in this embodiment are isoamyl alcohol and ethylene glycol. When isoamyl alcohol is used as the alcohol compound, a β-methyl-δ-valerolactone-based polymer represented by general formula (Ia) can be obtained, and when ethylene glycol is used, a β-methyl-δ-valerolactone-based polymer represented by general formula (Ib) can be obtained.

[0020] (Base Catalyst) Examples of the base catalyst that can be used in this embodiment include metal catalysts such as alkali metals and alkali metal compounds, and organic base compounds, etc. The base catalyst may be used alone or in combination of two or more kinds. Examples of the alkali metal compound include organic alkali metal compounds, alkali metal hydroxide compounds, and alkali metal hydride compounds, and among these, organic lithium compounds such as butyllithium are preferred. Examples of the organic base compound include amine compounds having an amidine skeleton or a guanidine skeleton. As the base catalyst, metal catalysts such as organomagnesium compounds and organozinc compounds can also be used. In the reaction step, it is preferable to add 0.005 to 1.5 molar equivalents of a base catalyst relative to the hydroxyl group of the alcohol compound.

[0021] (β-methyl-δ-valerolactone) The β-methyl-δ-valerolactone that can be used in this embodiment can be produced by a known method. For example, it can be produced by a known method using 2-hydroxy-4-methyltetrahydropyran or the like as a raw material (JP-B-6-53691, etc.). In addition, β-methyl-δ-valerolactone may be a commercially available product, and may be of petrochemical or biological origin. In the reaction step, β-methyl-δ-valerolactone is preferably added in an amount of 5 to 50 molar equivalents relative to the hydroxyl groups of the alcohol compound.

[0022] (Terminal Modifier) In this embodiment, acetic anhydride is used as the terminal modifying agent. In the reaction step, it is preferable to add 1.0 to 20.0 molar equivalents of acetic anhydride as a terminal modifier relative to the hydroxyl group of the alcohol compound.

[0023] (Co-catalyst) In the reaction step, a promoter may be added, if necessary. As the co-catalyst, for example, an amine compound such as triethylamine, tributylamine, trioctylamine, imidazole, pyridine, aminopyridine, or 4-dimethylaminopyridine can be used. In the reaction step, a promoter can be added in an amount of 0.001 to 10 molar equivalents relative to the hydroxyl groups of the alcohol compound.

[0024] (solvent) The reaction step can be carried out in the presence of a solvent inert to the ring-opening polymerization reaction, such as aliphatic hydrocarbons, such as cyclohexane, methylcyclohexane, n-hexane, and n-pentane, and aromatic hydrocarbons, such as benzene, toluene, and xylene.

[0025] (Reaction conditions) In the reaction step, the reaction temperature when reacting β-methyl-δ-valerolactone, the alcohol compound, and the base catalyst may usually be 20 to 100° C., and the reaction time is usually 1 minute to 24 hours. In the reaction step, after the terminal modification agent is added to the reaction solution, the reaction temperature for carrying out the terminal modification reaction may usually be 20 to 80° C., and the reaction time is usually 1 minute to 24 hours.

[0026] (Post-processing) The polymer of this embodiment can be produced through the above reaction steps. If necessary, a post-treatment step may be carried out to isolate the produced polymer. As the post-treatment step, a suitable method can be adopted from among known methods. For example, the reaction mixture after the reaction step can be washed with a reaction solvent or water, concentrated, and purified by a method typically used for separating and purifying organic compounds, such as distillation.

[0027] [3-Hydroxyalkanoate polymer] The 3-hydroxyalkanoate polymer of the present embodiment is represented by the following general formula (II).

[0028] [ka]

[0029] 〈k / p〉 The ratio of k to p (k / p) represents the ratio of each structural unit and is 70 / 30 to 99 / 1. When k / p is 70 / 30 or more, a molded article produced using the resin composition has sufficient strength and is excellent in practical use, and when k / p is 99 / 1 or less, the resin composition exhibits good impact resistance. In this specification, "k and p" are values ​​determined by gas chromatography measurement using the following method. 20 mg of 3-hydroxyalkanoate polymer is added to 2 ml of sulfuric acid-methanol mixture (15:85) and 2 ml of chloroform, sealed, and heated at 100°C for 140 minutes to obtain the methyl ester of the 3-hydroxyalkanoate polymer decomposition product. After cooling, 1.5 g of sodium bicarbonate is gradually added to neutralize the mixture, and the mixture is left to stand until no carbon dioxide gas is generated. Next, 4 ml of diisopropyl ether is added and mixed well, followed by centrifugation, and the monomer unit composition ratio of the polyester decomposition product in the supernatant is analyzed under the following measurement conditions. (Measurement conditions) Equipment: Gas chromatograph GC-17A (Shimadzu Corporation) Capillary column: NEUTRA BOND-1 (GL Sciences, Inc., column length 25 m, column inner diameter 0.25 mm, liquid film thickness 0.4 μm)

[0030] <Number average molecular weight (Mn)> The number average molecular weight of the 3-hydroxyalkanoate polymer is preferably 20,000 to 1,000,000, and more preferably 50,000 to 700,000. When the number average molecular weight is within the above range, the viscosity of the resin composition is prevented from becoming too low or too high, and the handling property and productivity during molding are improved.

[0031] <Weight average molecular weight (Mw)> The weight-average molecular weight of the 3-hydroxyalkanoate polymer is preferably 50,000 to 3,000,000, and more preferably 100,000 to 1,500,000. When the weight-average molecular weight is within the above range, the viscosity of the resin composition is prevented from becoming too low or too high, and the handling property and productivity during molding are improved.

[0032] <Molecular weight distribution (Mw / Mn)> The molecular weight distribution (Mw / Mn) of the 3-hydroxyalkanoate polymer is preferably from 1.0 to 3.0, more preferably from 1.1 to 2.0, and further preferably from 1.2 to 1.8.

[0033] <Manufacturing method> The 3-hydroxyalkanoate polymer of this embodiment is preferably produced by a microorganism, that is, obtained by a fermentation synthesis method. The microorganism that can be used in this fermentation synthesis method is not particularly limited as long as it is a microorganism capable of producing a 3-hydroxyalkanoate polymer. As a 3-hydroxyalkanoate polymer-producing bacterium, Aeromonas caviae, poly(3-hydroxybutyrate-co-4-hydroxybutyrate)-producing bacterium, and the like are known. From the viewpoint of productivity, Alcaligenes eutrophus AC32 strain (FERM BP-6038) (J.Bateriol., 179, pp. 4821-4830 (1997)) into which genes of a group of synthetic enzymes have been introduced is more preferable, and the microbial cells in which the 3-hydroxyalkanoate polymer has been accumulated by culturing these microorganisms under appropriate conditions may be used.

[0034] Carbon sources and culture conditions used in culturing microorganisms capable of producing 3-hydroxyalkanoate polymers are described in JP-A-5-93049, JP-A-2001-340078, etc. For example, fats and oils such as vegetable oils and fish oils are used as carbon sources, and the culture is performed under limited nutrients such as nitrogen, phosphorus, and minerals other than the carbon source to produce 3-hydroxyalkanoate polymers as storage substances inside the microbial cells. The culture conditions such as pH, temperature, aeration, and culture time are appropriately adjusted.

[0035] [Content ratio] The resin composition of this embodiment contains the β-methyl-δ-valerolactone polymer in an amount of preferably 5 parts by mass or more and 20 parts by mass or less, more preferably 10 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the 3-hydroxyalkanoate polymer. The above content ratio allows the resin composition to have better impact resistance.

[0036] In the resin composition of this embodiment, the total content of the β-methyl-δ-valerolactone polymer and the 3-hydroxyalkanoate polymer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass or more. With the above content, the effect of the present invention is more significantly exhibited.

[0037] In the resin composition of this embodiment, the content of the β-methyl-δ-valerolactone polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and is preferably 20% by mass or less, more preferably 18% by mass or less. With the above content, the effect of the present invention is more significantly exhibited.

[0038] The content of the 3-hydroxyalkanoate polymer in the resin composition of this embodiment is preferably 80% by mass or more, more preferably 82% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less. With the above content, the effects of the present invention are more significantly exhibited.

[0039] [Additives] The resin composition of this embodiment may contain additives other than the β-methyl-δ-valerolactone polymer and the 3-hydroxyalkanoate polymer. Examples of additives include inorganic fillers, softeners, heat aging inhibitors, antioxidants, hydrolysis resistance inhibitors, light stabilizers, antistatic agents, release agents, flame retardants, foaming agents, pigments, dyes, brightening agents, ultraviolet absorbers, lubricants, etc. These may be used alone or in combination of two or more. When the above additives are used, the content of the additives in the resin composition may be appropriately determined depending on the desired physical properties of the resin composition.

[0040] [Method of producing resin composition] There is no particular limitation on the method for producing the resin composition of this embodiment, and it is sufficient to uniformly mix the β-methyl-δ-valerolactone polymer, the 3-hydroxyalkanoate polymer, and, if necessary, additives. Examples of the mixing method include a method of melt-kneading using a single-screw extruder, a multi-screw extruder, a Banbury mixer, a heating roll, a Brabender, various kneaders, etc., or a method of feeding each component through a separate inlet and melt-kneading the components. Also, pre-blending may be performed before melt-kneading. Examples of the pre-blending method include a method using a mixer such as a Henschel mixer, a high-speed mixer, a V blender, a ribbon blender, a tumbler blender, or a conical blender. The temperature during melt-kneading is preferably set to an upper limit of about 185°C, taking into consideration the melting point and decomposition temperature of the 3-hydroxyalkanoate polymer. Therefore, for example, the temperature may be about 100 to 185°C, or may be arbitrarily selected within the range of 120 to 180°C.

[0041] <Molded body> By using the resin composition of this embodiment, a molded article having good impact resistance can be obtained. The shape of the molded body may be any molded body that can be produced using the resin composition of this embodiment. Examples of the molded body include molded bodies of various shapes such as pellets, films, sheets, plates, pipes, tubes, bottles, fibrous bodies, rods, fine particles, particulate bodies, and foams. The method for producing the molded body is not particularly limited, and the molded body can be molded by various known molding methods such as injection molding, blow molding, press molding, extrusion molding, calendar molding, and molding using a 3D printer.

[0042] <Application> The β-methyl-δ-valerolactone polymer represented by the above general formula (Ia) or (Ib) can improve impact resistance by mixing it with a 3-hydroxyalkanoate polymer to form a resin composition. Therefore, the β-methyl-δ-valerolactone polymer represented by the above general formula (Ia) or (Ib) is useful as a modifier for the 3-hydroxyalkanoate polymer. EXAMPLES

[0043] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0044] <Measurement and evaluation methods> Various physical properties were measured or evaluated by the following methods.

[0045] [Average degree of polymerization of β-methyl-δ-valerolactone polymers] In the production examples, the degree of polymerization of the terminally modified β-methyl-δ-valerolactone polymer obtained was 1 The proton signal of the initiator alcohol determined by H-NMR measurement was used as a reference, and the ratio of the proton signal of the repeating unit of the polymer was used for calculation. (Measurement conditions) Equipment: 400YH (manufactured by JEOL Ltd.) Solvent: deuterated chloroform (CDCl 3 ) Measurement temperature: 23℃ (Polymerization degree calculation method) In the case of Production Example I-1, the terminal CH of the initiator, isoamyl alcohol 3 (0.9-0.92 ppm, d) Proton number X and the repeating structural unit β-methyl-δ-valerolactone methyl branch CH 3 Using the number of protons Y of (0.98-1.00 ppm, d), n was calculated using the following formula (1). n=2×Y / X (1) In the case of Production Example I-2, the CH reaction of the initiator ethylene glycol 2 (4.28-4.30 ppm, m) proton number X' and the repeating structural unit β-methyl-δ-valerolactone methyl branch CH 3 Using the number of protons Y' of (0.98-1.00 ppm, d), l+m was calculated using the following formula (2). l+m=4×Y' / (3×X') (2)

[0046] [k / p of 3-hydroxyalkanoate polymer] The k / p of the 3-hydroxyalkanoate polymer (P3HB3HH-1) was determined by gas chromatography. The specific measurement method is as follows. 20 mg of P3HB3HH-1 obtained in the manufacturing example was added with 2 ml of a sulfuric acid-methanol mixture (15:85) and 2 ml of chloroform, sealed, and heated at 100°C for 140 minutes to obtain a methyl ester of a 3-hydroxyalkanoate polymer decomposition product. After cooling, 1.5 g of sodium bicarbonate was gradually added to neutralize the mixture, and the mixture was left to stand until no carbon dioxide gas was generated. Next, 4 ml of diisopropyl ether was added and mixed well, followed by centrifugation, and the monomer unit composition ratio of the polyester decomposition product in the supernatant was analyzed under the following measurement conditions. (Measurement conditions) Equipment: Gas chromatograph GC-17A (Shimadzu Corporation) Capillary column: NEUTRA BOND-1 (GL Sciences, Inc., column length 25 m, column inner diameter 0.25 mm, liquid film thickness 0.4 μm)

[0047] [Number-average molecular weight and weight-average molecular weight of β-methyl-δ-valerolactone polymer] The polymer after the terminal modification reaction of the β-methyl-δ-valerolactone polymer was used as a sample, and the number average molecular weight (Mn) and weight average molecular weight (Mw) of the β-methyl-δ-valerolactone polymer were determined by gel permeation chromatography (GPC) in terms of standard polystyrene. The specific measurement method is as follows. A tetrahydrofuran (THF) solution was used as the eluent, and 10 mg of the sample was weighed out in terms of resin and dissolved in 1 mL of the eluent. The solution was passed through a 0.2 μm membrane filter to prepare a measurement sample. The specific measurement method is as follows. (Measurement conditions) Equipment: HLC-EcoSEC8320GPC (Tosoh Corporation) Columns: KF-803, KF-802.5, and KF-802 (manufactured by Resonac Corporation), three columns connected in series. Eluent: Tetrahydrofuran Flow rate: 0.9mL / min Sample injection volume: 30 μL Column temperature: 40℃ Standard polystyrene: Tosoh Corporation's PSt Oligomer Kit (molecular weight 589 to 98,900) was used and approximated by a third-order equation. Detector: RI detector

[0048] [Weight average molecular weight of 3-hydroxyalkanoate polymer] The weight average molecular weight (Mw) of the 3-hydroxyalkanoate polymer was determined by gel permeation chromatography (GPC) in terms of standard polystyrene. The specific measurement method is as follows. (Measurement conditions) Equipment: High-performance liquid chromatograph LC-20A (Shimadzu Corporation) Columns: KG 4A (1 column) and K-806M (2 columns) (manufactured by Resonac Co., Ltd.) were connected in series. Eluent: Chloroform Flow rate: 1.0mL / min Sample injection volume: 100 μL Column temperature: 40℃ Standard polystyrene: Polystyrene standards (molecular weight: 2,880 to 6,570,000) manufactured by Agilent Technologies were used and approximated by a quintic equation. Detector: RI detector

[0049] [Impact resistance test] (1) Preparation of test specimens for impact resistance tests The resin compositions (pellets) obtained in the examples and comparative examples were put into an injection molding machine ("SI-30IV-CCH150B" manufactured by Shibaura Machine Co., Ltd.) and molded into plate-like molded articles measuring 80×80 mm and 1 mm in thickness at a cylinder temperature of 120 to 150° C. (exit resin temperature of 160° C.) and a mold setting temperature of 35° C. The obtained plate-like molded articles were cut into pieces measuring 40×40 mm to prepare test pieces. (2) Impact resistance test The obtained test pieces were evaluated for impact resistance using a DuPont drop impact tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) in accordance with JIS K 7211-1:2006. When a 2 kg weight was dropped from a height of 100 cm, the test piece was rated as "good" if it was not destroyed, and as "bad" if it was destroyed.

[0050] [Manufacturing example I-1] A 500 mL glass four-neck flask was purged with nitrogen, and 7.9 g (90 mmol) of isoamyl alcohol and 231 g (2.025 mol) of β-methyl-δ-valerolactone were added and heated to 60° C. 0.84 mL of n-butyllithium (1.6 M hexane solution) was added thereto and stirred at 60° C. for 60 minutes. Next, 11.0 g (108 mmol) of acetic anhydride and 0.55 g (4.5 mmol) of 4-dimethylaminopyridine dissolved in 5.5 g of β-methyl-δ-valerolactone were added to the above four-necked glass flask and stirred at 60°C for 60 minutes to obtain a reaction solution containing a β-methyl-δ-valerolactone polymer. The reaction solution containing the obtained β-methyl-δ-valerolactone polymer was extracted with toluene and water and purified using a thin-film evaporator ("Molecular Distillation Apparatus MS-300" manufactured by Shibata Scientific Co., Ltd.) to obtain 155 g of β-methyl-δ-valerolactone polymer. The obtained β-methyl-δ-valerolactone polymer (hereinafter sometimes referred to as “PMVL-1”) is represented by the above-mentioned general formula (Ia). The physical properties of the obtained PMVL-1 were measured as described above. The results are shown in Table 1.

[0051] [Manufacturing example I-2] A 500 mL glass four-neck flask was purged with nitrogen, and 11.3 g (183 mmol) of ethylene glycol and 184 g (1.616 mol) of β-methyl-δ-valerolactone were added and heated to 60° C. 1.18 mL of n-butyllithium (1.6 M hexane solution) was added thereto and stirred at 60° C. for 60 minutes. Next, 44.2 g (433 mmol) of acetic anhydride and 2.23 g (18.3 mmol) of 4-dimethylaminopyridine dissolved in 20.8 g of β-methyl-δ-valerolactone were added to the above-mentioned four-necked glass flask, and the mixture was stirred at 60°C for 60 minutes to obtain a reaction solution containing a β-methyl-δ-valerolactone polymer. The reaction solution containing the obtained β-methyl-δ-valerolactone polymer was extracted with toluene and water and purified using a thin-film evaporator ("Molecular Distillation Apparatus MS-300" manufactured by Shibata Scientific Co., Ltd.) to obtain 161 g of β-methyl-δ-valerolactone polymer. The obtained β-methyl-δ-valerolactone polymer (hereinafter, sometimes referred to as “PMVL-2”) is represented by the above-mentioned general formula (Ib). The physical properties of the resulting PMVL-2 were measured as described above, and the results are shown in Table 1.

[0052] [Manufacturing example II] Alcaligenes eutrophus AC32 (Accession No. FERM BP-6038) into which polyhydroxyalkanoate synthase group genes derived from Aeromonas caviae have been introduced was cultured by the method described in Example 1 of JP-A 2001-340078 to produce 3-hydroxyalkanoate polymers. That is, Alcaligenes eutrophus AC32 (Accession No. FERM BP-6038) (hereinafter abbreviated as "AC32") was cultured as follows. The composition of the medium was 1 w / v% Meat-extract, 1 w / v% Bacto-Trypton, 0.2 w / v% Yeast-extract, 0.9 w / v% Na 2 HPO 4 12H 2 O, 0.15w / v% KH 2 PO 4 The composition of the polyester production medium was 1.1 w / v% Na 2 HPO 4 12H 2 O, 0.19w / v% KH2 PO 4 , 0.6w / v% (NH 4 ) 2 SO 4 , 0.1w / v% MgSO 4 7H 2 0.5v / v% trace metal salt solution (1.6w / v% FeCl in 0.1N hydrochloric acid) 3 6H 2 O, 1w / v% CaCl 2 2H 2 O, 0.02w / v% CoCl 2 6H 2 O, 0.016w / v% CuSO 4 5H 2 O, 0.012w / v% NiCl 3 6H 2 O, 0.01w / v% CrCl 3 6H 2 O dissolved in water), 2 w / v% Proex AP-12 (Banshu Seasoning Co., Ltd.), 5 × 10 -6 The culture medium was inoculated with glycerol stock of AC32 strain, cultured for 20 hours, and inoculated at 1.5 v / v% into a 10 L jar fermenter (Marubishi Bioengineering Co., Ltd., "MD-500 type") containing 6 L of production medium. The operating conditions were a culture temperature of 30°C, a stirring speed of 400 rpm, and aeration of 1.8 L / min, and the pH was controlled between 6.6 and 6.8. 5N sulfuric acid and sodium hydroxide were used to control the pH. Culture was continued for up to 72 hours. The cells were collected by centrifugation, washed with methanol, and then freeze-dried. The 3-hydroxyalkanoate polymer was extracted from the dried cells using chloroform, and then the chloroform solution containing the 3-hydroxyalkanoate polymer was filtered to remove the cell components, and methanol was added to the filtrate to precipitate the 3-hydroxyalkanoate polymer. The supernatant was then removed by centrifugation, and the 3-hydroxyalkanoate polymer was obtained by drying. The obtained 3-hydroxyalkanoate polymer (hereinafter sometimes referred to as "P3HB3HH-1") is represented by the above-mentioned general formula (II). The physical properties of the resulting P3HB3HH-1 were measured as described above, and the results are shown in Table 1.

[0053] [Table 1]

[0054] [Examples 1 and 2, and Comparative Example 1] The β-methyl-δ-valerolactone polymer and 3-hydroxyalkanoate polymer obtained in the production example were fed into a co-rotating intermeshing twin screw extruder (Shibaura Machine Co., Ltd. "TEM26ss"), melt-kneaded at a cylinder temperature of 140 to 160°C and a screw rotation speed of 100 rpm, and the extruded strand was cut to produce a resin composition (pellet). The evaluation results of the resin composition are shown in Table 2.

[0055] [Table 2]

[0056] It is understood from Examples 1 and 2 and Comparative Example 1 that the resin compositions obtained in the Examples are resin compositions having improved impact resistance at the above-mentioned temperatures. It is also understood from Examples 1 and 2 and Comparative Example 1 that the β-methyl-δ-valerolactone polymers obtained in Production Examples 1 and 2 are useful as modifiers for 3-hydroxyalkanoate polymers.

Claims

1. A resin composition containing a β-methyl-δ-valerolactone polymer represented by the following general formula (I-a) or (I-b) and a 3-hydroxyalkanoate polymer represented by the following general formula (II): 【Chemistry 1】 [In general formula (I-a), n is 5 to 20. In general formula (Ib), l and m each independently represent 2 to 10. 【Chemistry 2】 [In general formula (II), The ratio of k to p (k / p) is 70 / 30 to 99 / 1.]

2. 2. The resin composition according to claim 1, comprising 5 to 20 parts by mass of the β-methyl-δ-valerolactone polymer per 100 parts by mass of the 3-hydroxyalkanoate polymer.

3. 3. The resin composition according to claim 1, wherein the β-methyl-δ-valerolactone polymer has a number average molecular weight of 1,000 to 4,000.

4. 3. The resin composition according to claim 1, wherein the 3-hydroxyalkanoate polymer has a weight average molecular weight of 50,000 to 3,000,000.

5. 3. The resin composition according to claim 1, wherein the β-methyl-δ-valerolactone polymer is represented by general formula (Ia).

6. 3. The resin composition according to claim 1, wherein the β-methyl-δ-valerolactone polymer is represented by general formula (I-b).

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