JP2006137853A - Resin composition - Google Patents

Abstract

The present invention provides a resin composition comprising a poly-3-hydroxybutyrate polymer excellent in impact resistance and heat resistance and a core-shell type latex rubber.
A core-shell in which a poly3-hydroxybutyrate-based polymer is 50 to 99% by weight, the core component is an acrylic rubber and / or a silicone-acrylic rubber copolymer, and the shell component is polymethylmethacrylate. A resin composition comprising 50 to 1% by weight of a latex rubber and satisfying the following requirements (a) and (b).
(A) Crystal in a differential scanning calorimeter when heated from room temperature to 180 ° C. at a temperature increase rate of 80 ° C./min, held at 180 ° C. for 1 minute, and then cooled at a temperature decrease rate of 10 ° C./min The conversion temperature is 110 ° C. or higher and 170 ° C. or lower.
(B) The polystyrene-equivalent weight average molecular weight (Mw) when the chloroform-dissolved component is measured by gel permeation chromatography is 100,000 or more and 3000000 or less.
[Selection figure] None.

Description

  The present invention relates to a resin composition comprising a poly-3-hydroxybutyrate polymer and a core-shell type latex rubber, and more specifically, a poly-3-hydroxybutyrate heavy polymer having excellent impact resistance and heat resistance. The present invention relates to a resin composition comprising a coalescence and a core-shell type latex rubber.

  Since poly-3-hydroxybutyrate polymers are obtained from plants as raw materials, they have recently attracted attention as materials with little environmental impact. However, the poly 3-hydroxybutyrate polymer has a problem that it is inferior in impact resistance.

  As a method for solving this problem, a method of mixing polycaprolactone or polybutylene succinate resin has been proposed (for example, see Patent Documents 1 and 2).

JP-A-9-194281 (first page) JP 11-323141 A (first page)

  However, in the method of mixing the different polymers proposed in Patent Documents 1 and 2, the impact resistance is not sufficient and the heat resistance is low.

  Therefore, the present invention provides a resin composition excellent in heat resistance and impact resistance, comprising a poly-3-hydroxybutyrate polymer and a core-shell type latex rubber.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor shows excellent impact resistance and heat resistance of a resin composition comprising a poly-3-hydroxybutyrate polymer and a specific core-shell type latex rubber. As a result, the present invention has been completed.

That is, the present invention relates to a core in which the poly 3-hydroxybutyrate polymer is 50 to 99% by weight, the core component is an acrylic rubber and / or silicon / acrylic rubber copolymer, and the shell component is polymethyl methacrylate. -It is related with the resin composition which consists of 50 to 1 weight% of shell type latex rubbers, and satisfy | fills the requirements shown to following (a) and (b).
(A) Crystal in a differential scanning calorimeter when heated from room temperature to 180 ° C. at a temperature increase rate of 80 ° C./min, held at 180 ° C. for 1 minute, and then cooled at a temperature decrease rate of 10 ° C./min The conversion temperature is 110 ° C. or higher and 170 ° C. or lower.
(B) The polystyrene-equivalent weight average molecular weight (Mw) when the chloroform-dissolved component is measured by gel permeation chromatography is 100,000 or more and 3000000 or less.

  The present invention is described in detail below.

  Examples of the poly-3-hydroxybutyrate polymer (hereinafter referred to as “PHB polymer”) used in the present invention include poly-3-hydroxybutyrate homopolymer, 3-hydroxybutyrate and 3-hydroxybutyrate. And a copolymer with a hydroxyalkanoate other than the rate. Examples of hydroxyalkanoates other than 3-hydroxybutyrate when the PHB polymer is a copolymer include 3-hydroxypropionate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxy Examples include heptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 4-hydroxybutyrate, and hydroxylaurylate. Further, as the copolymer, since a resin composition excellent in molding processability can be obtained, it is preferable that a hydroxyalkanoate other than the 3-hydroxybutyrate is copolymerized in an amount of 25 mol% or less. preferable.

  The PHB polymer used in the present invention includes, in particular, poly-3-hydroxybutyrate homopolymer, 3-hydroxybutyrate / 3-hydroxyvalerate copolymer, 3-hydroxybutyrate / 4-hydroxybutyrate. A copolymer is preferred because it is readily available.

  Moreover, since it becomes a resin composition excellent in molding processability, it is preferable that the PHB-based polymer is produced in a microorganism. Such a PHB polymer can be obtained as a commercial product. Moreover, as the manufacturing method, it can also obtain by the method currently disclosed by the US Patent 4477654 gazette, the international publication 94/115519 gazette, the US Patent 5502273 gazette, etc., for example.

  The core-shell type latex rubber used in the present invention is a core-shell type latex rubber in which the core component is an acrylic rubber and / or silicon / acrylic rubber copolymer, and the shell component is polymethyl methacrylate. The resin composition of the present invention becomes a resin composition excellent in heat resistance and impact resistance by using a core-shell type latex rubber comprising such components.

  The method for producing the core-shell type latex rubber used in the present invention is not particularly limited. For example, multistage emulsion polymerization or multistage seed polymerization known as a general method for producing core-shell type latex rubber is performed. Can be manufactured. In addition, in that case, since the resin composition which is excellent in especially impact resistance is obtained, it is preferable that the average particle diameter of a core component is 0.05-1 micrometer. The core-shell type latex rubber used in the present invention is a commercially available product, for example, (trade name) Metabrene S-2001 (manufactured by Mitsubishi Rayon Co., Ltd.), (trade name) Metabrene W-450A (manufactured by Mitsubishi Rayon Co., Ltd.). Etc. can be obtained and used.

  Furthermore, since the core-shell type latex rubber used in the present invention is more excellent in impact resistance of the resulting resin composition, the tensile storage elastic modulus (E ′) at a measurement temperature of 0 ° C. and a measurement frequency of 10 Hz. Is preferably 1 MPa or more and 100 MPa or less, and the temperature at which the loss tangent (tan δ) has a maximum value is preferably −50 ° C. or more and 0 ° C. or less. Further, at that time, the maximum value of the loss tangent is preferably more than 0.3 because the resulting resin composition is further excellent in impact resistance. The tensile storage modulus and loss tangent can be measured with a dynamic viscoelasticity measuring device using a test piece having a thickness of 0.5 to 2 mm formed by compression molding.

  The resin composition of the present invention comprises 50 to 99% by weight of the PHB polymer and 50 to 1% by weight of the core-shell type latex rubber, and 60 to 95% by weight of the PHB polymer and the core-shell. Type latex rubber is preferably 40 to 5% by weight, more preferably 65 to 90% by weight of PHB polymer and 35 to 10% by weight of the core-shell type latex rubber. Here, when the weight ratio of the core-shell type latex rubber is less than 1% by weight, the resulting resin composition is inferior in impact resistance. On the other hand, when it exceeds 50 weight%, the resin composition obtained becomes inferior to heat resistance.

  Furthermore, the resin composition of the present invention is heated from room temperature to 180 ° C. at a temperature rising rate of 80 ° C./min with a differential scanning calorimeter (hereinafter referred to as “DSC”) at 180 ° C. After holding for 1 minute, the crystallization temperature cooled at a rate of temperature drop of 10 ° C./min is 110 ° C. or higher and 170 ° C. or lower, preferably 115 ° C. or higher and 160 ° C. or lower, and 120 ° C. or higher and 150 ° C. or lower. Is more preferable. Here, when the crystallization temperature is less than 110 ° C., the resulting resin composition has a low crystallization rate and inferior production efficiency when formed into a molded product. On the other hand, it is practically difficult to obtain a resin composition having a crystallization temperature exceeding 170 ° C. The crystallization temperature is an aluminum pan loaded with 5 mg of sample in DSC (Perkin Elmer, trade name DSC-7) measurement, and the pan is heated from room temperature to 80 ° C./min. This is the highest temperature among the peak temperatures of heat flux based on crystallization observed when heated to 180 ° C., held at 180 ° C. for 1 minute, and then cooled at a temperature decrease rate of 10 ° C./min.

  The resin composition of the present invention has a polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) when (b) a chloroform-dissolved component is measured by gel permeation chromatography (hereinafter referred to as “GPC”). It is preferably 100,000 or more and 3000000 or less, and particularly preferably 120,000 or more and 1000000 or less. Here, when Mw is less than 100,000, the obtained resin composition is inferior in mechanical strength. On the other hand, when Mw exceeds 3000000, the obtained resin composition is inferior in molding processability. In addition, Mw of the chloroform melt | dissolution component of a resin composition can also be measured by the molecular weight of the melt | dissolution part obtained by melt | dissolving a resin composition or its molding in 60 degreeC chloroform for 2 hours. In addition, the measurement of Mw in the present invention uses a GPC apparatus (manufactured by Tosoh Corporation, trade name HLC8020GPC) equipped with two columns (trade name TSKgel GMHHR-H, manufactured by Tosoh Corporation) and measuring solvent: chloroform. Using a standard polystyrene (manufactured by Tosoh Corporation), the column elution volume was measured at a measurement temperature of 40 ° C., a sample dissolution condition: 60 ° C., and a sample prepared at a measurement concentration of 50 mg / 50 mL in 2 hours with an injection volume of 100 μL. This was calibrated.

Since the resin composition of the present invention exhibits excellent impact resistance and heat resistance, when an ultrathin section of a compression molded specimen is prepared and observed with a transmission electron microscope, the core-shell type latex rubber is It is preferable that a continuous phase is not formed, and the agglomerates of core-shell type latex rubber having a diameter of 1 μm or more are preferably less than 2 (pieces / 100 μm ² ).

  Since the resin composition of the present invention exhibits excellent moldability, the phthalic acid plasticizer 0.1 is further added to 100 parts by weight of the total amount of the PHB polymer and the core-shell type latex rubber. It preferably comprises -30 parts by weight. As the phthalic acid plasticizer, those that lower the crystal melting point of the PHB polymer by 3 ° C. or more are preferable. The phthalic acid plasticizer is not particularly limited. For example, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, di-2-ethylhexyl phthalate (DOP), dibutylbenzyl phthalate, dicyclohexyl phthalate, dimethylcyclohexyl phthalate Moreover, you may use these 1 type or 2 types or more in mixture.

  Examples of the shape of the resin composition of the present invention include a pellet shape, a powder shape, a lump shape, and the like. Among them, the pellets are excellent in production efficiency at the time of manufacture and excellent in handleability at the time of molding. The shape is preferred. As a method for forming a pellet, for example, a strand cutting method of cutting a strand-shaped molten granulated product with a strand cutter, an underwater cutting method of cutting a molten resin in water, or cutting the molten resin as it is or by cooling with mist or the like Examples include the hot-cut method and the sheet pelletizing method in which a sheet-shaped molten granule is cut with a sheet pelletizer. Among them, strand cutting is particularly possible because pellets with good resin bite can be obtained during injection molding and extrusion molding. The method, the underwater cut method and the hot cut method are preferable.

  As a method for producing the resin composition of the present invention, any method and apparatus may be used as long as the PHB polymer and the core-shell type latex rubber can be mixed. Since a resin composition having excellent properties can be obtained, the resin composition is preferably manufactured using a kneader whose temperature is set so that the temperature of the molten resin discharged from the die of the extruder is 160 ° C. or higher and 185 ° C. or lower. The kneading machine to be used is not particularly limited, and examples thereof include different-direction twin-screw extruders such as the same-direction twin-screw extruder and conical twin-screw extruder; batch-type mixers such as a Banbury mixer and a pressure kneader, and roll kneaders. Is done. Among these, a different-direction twin screw extruder equipped with a strong kneading type screw such as a kneading disk is preferable because a composition exhibiting excellent impact resistance and heat resistance can be obtained.

  When producing the resin composition of the present invention, it is desirable to dry the PHB polymer in advance, and the drying conditions are not particularly limited, for example, at a temperature of 40 to 90 ° C. for 30 minutes to 3 days. It is preferable to dry to a certain extent. Further, when molding the resin composition of the present invention, it is desirable to dry the resin composition in advance, and the drying conditions are arbitrary, for example, at a temperature of 40 to 90 ° C. for 30 minutes to It is preferable to dry for about 3 days.

  The molding method of the resin composition of the present invention is not particularly limited, and examples thereof include profile extrusion, film, sheet, blow, injection, foaming, extrusion coating, rotational molding, etc. Among them, injection molding is a preferable example. . In the case of performing injection molding, if the temperature of the molten resin is 230 ° C. or lower, preferably 210 ° C. or lower, the time required for crystallization in the mold is small, and the molding cycle can be shortened.

  You may add a filler to the resin composition of this invention. There is no particular limitation on the filler to be added, for example, calcium carbonate, mica, talc, silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, sericanite, zeolite, nepheline cinnite, attapulgite, wollastonite, ferrite , Inorganic filler such as calcium silicate, magnesium carbonate, dolomite, antimony trioxide, titanium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass powder, glass balloon, glass fiber, quartz, quartz glass, montmorillonite Materials: Various plant fibers such as starch, cellulose fiber and kenaf; natural fillers such as wood flour, okara, fir shell, bran, and organic fillers such as modified products thereof.

  Among them, calcium carbonate and talc also have a function of increasing the crystallization speed, so it is preferable to add them, and talc is particularly preferable. Moreover, in order to improve the dispersibility in the resin composition of the present invention, it is also possible to use surface-modified calcium carbonate, talc, or clay. When a filler is added, it becomes a resin composition excellent in the balance between rigidity and impact resistance. Therefore, it is preferably used at 100 parts by weight or less with respect to 100 parts by weight of the resin composition of the present invention.

  Furthermore, fatty acids, aliphatic esters, aliphatic amides, and fatty acid metal salts can be added to the resin composition of the present invention.

  In addition, the resin composition of the present invention may contain a crystal nucleating agent as necessary, which further increases the crystal growth rate. Examples of the crystal nucleating agent include boron nitride, mica, talc, alumina, calcium hydroxyapatite, aluminum chloride, and clay. Among these, talc and boron nitride are preferable.

  Furthermore, the resin composition of the present invention includes an anti-hydrolysis agent typified by carbodiimide, an anti-blocking agent, a release agent, an antistatic agent, a slip agent, an antifogging agent, a lubricant, a heat stabilizer, and an ultraviolet ray as necessary. Stabilizers, light stabilizers, weathering stabilizers, antifungal agents, rust inhibitors, ion trap agents, foaming agents, flame retardants, flame retardant aids, and the like may be included. Furthermore, other thermoplastic resins and rubbers, particularly thermoplastic resins called biodegradable resins may be blended.

  The resin composition of the present invention is used for the housing and structure of electrical products; automotive exterior parts such as bumpers, rocker moldings, side moldings, and over fenders; automotive interior parts such as carpets, head liners, door trims, sun visors, etc. For example, it is suitably used.

  The resin composition of the present invention is excellent in heat resistance and impact resistance and is useful as various molded article materials.

  Hereinafter, the present invention will be described with reference to examples, but these are illustrative and the present invention is not limited to these examples.

  Various measurements in Examples and Comparative Examples are shown below.

(Measurement of crystallization temperature)
The crystal growth rate was measured using a differential scanning calorimeter (manufactured by Perkin Elmer, trade name DSC-7). A 5 mg sample is cut from the pellet and loaded into an aluminum pan. The pan is heated from room temperature to 180 ° C. at a heating rate of 80 ° C./min and held at 180 ° C. for 1 minute. Then, it cooled at the speed | rate of 10 degree-C / min, and made the highest temperature among the peak temperature of the heat flux based on crystallization the crystallization temperature.

(Measurement of crystal melting point)
The crystal melting point was measured using a differential scanning calorimeter (trade name DSC-7, manufactured by Perkin Elmer). A 5 mg sample is cut from the pellet and loaded into an aluminum pan. The highest temperature among the peak temperatures of heat flux based on crystal melting observed when the pan was heated from room temperature at a heating rate of 10 ° C./min was defined as the crystal melting point.

(Measurement of weight average molecular weight)
The molecular weight was measured by gel permeation chromatography using only the dissolved components obtained by dissolving the pellets obtained by granulation in chloroform at 60 ° C. for 2 hours. Calibration was performed using standard polystyrene (manufactured by Tosoh Corporation), and the weight average molecular weight (Mw) was determined in terms of polystyrene. The measurement conditions are shown below.

Model: Product name HLC8020GPC (manufactured by Tosoh Corporation)
Solvent: Chloroform Sample dissolution conditions: 60 ° C, 2 hours Temperature: 40 ° C
Measurement concentration: 50 mg / 50 mL
Injection volume: 100 μL
Column: Two trade names TSKgel GMHHR-H (manufactured by Tosoh Corporation) (measurement of linear viscoelasticity)
Using a solid viscoelasticity measuring device (trade name DVE-V4, manufactured by Rheology), the temperature dependence of the dynamic tensile elastic modulus was measured in the tensile mode. A core-shell type latex rubber plate molded to a thickness of 1 mm by a compression molding machine was cut into 5 mm width × 20 mm length to obtain a test piece. The measurement frequency of linear viscoelasticity was 10 Hz, the rate of temperature increase was 2 ° C./min, and the measurement temperature range was −100 ° C. to 100 ° C. Moreover, the distortion of the sine wave was given in tension mode. Measure the temperature at which the loss tangent (tan δ) shows a maximum value at −100 ° C. to 50 ° C., the maximum value of the loss tangent in the temperature range of −50 ° C. to 0 ° C., and the tensile storage modulus (E ′) at 0 ° C. did.

(Measurement of Izod impact strength)
Izod impact strength at 23 ° C. was measured according to ASTM D256 using a notched Izod test piece obtained by injection molding. The impact was applied from the notch side. The injection molding was performed using an injection molding machine (trade name IS100E, manufactured by Toshiba Machine Plastic Co., Ltd.) under the conditions of a nozzle temperature of 175 ° C., an injection time of 10 seconds, and a mold temperature of 60 ° C.

(Observation of phase structure)
The compression molded test piece was cut into ultrathin sections with an ultramicrotome, stained with ruthenic acid, and then observed with a transmission electron microscope (manufactured by JEOL Ltd., trade name JEM-2000FX). The number of agglomerates exceeding 1 μm in diameter was counted among the core-shell type latex rubbers present in an arbitrarily selected 10 μm × 10 μm visual field. Moreover, the continuous phase was judged from the micrograph. The compression molding was performed under the conditions of a heating temperature of 180 ° C., a pressure of 10 MPa, a heating time of 3 minutes, and a cooling temperature of 60 ° C. to obtain a test piece having a thickness of 1 mm.

(Measurement of heat resistance)
Vicat softening temperature was measured according to JIS K7206 using the injection test piece.

Example 1
70% by weight of poly 3-hydroxybutyrate polymer (PHB Industrial S / A, trade name Biocycle 1000) preliminarily dried in an oven at 80 ° C. for 4 hours in advance, the shell component is polymethyl methacrylate, and the core component is acrylic Core-shell type latex rubber (Mitsubishi Rayon Co., Ltd., trade name: Metabrene W-450A) 30% by weight, a bi-directional extruder with a circular die (made by Toyo Seiki Seisakusho, trade name: Labo Blast Mill; Resin Resin at a temperature of 178 ° C., a rotational speed of 100 rpm, using a strong kneading type screw), solidifying the extruded strand in a hot bath set at 60 ° C., and pelletizing with a strand cutter. A composition was obtained.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 2
Further, di-2-ethylhexyl phthalate (DOP) 10 was added to 100 parts by weight of the total amount of 70% by weight of the poly-3-hydroxybutyrate polymer and 30% by weight of the core-shell type latex rubber described in Example 1. A pellet-shaped resin composition was obtained in the same manner as in Example 1 except that the parts by weight were blended.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 3
Instead of core-shell type latex rubber (product name: Metabrene W-450A, manufactured by Mitsubishi Rayon Co., Ltd.), core-shell type latex rubber (Mitsubishi Rayon, whose core component is a silicone / acrylic rubber copolymer and whose shell component is polymethyl methacrylate) A pellet-shaped resin composition was obtained in the same manner as in Example 1 except that the product name “Madebrene S-2001” was used.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 4
Example 3 except that 10 parts by weight of diethyl phthalate (DEP) was used with respect to 100 parts by weight of the total amount consisting of 70% by weight of poly-3-hydroxybutyrate polymer and 30% by weight of core-shell type latex rubber. A pellet-shaped resin composition was obtained by the same method as described above.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 5
To 100 parts by weight of the total amount of 70% by weight of poly-3-hydroxybutyrate polymer and 30% by weight of core-shell type latex rubber, talc (trade name: MICRO ACE P-manufactured by Nippon Talc Co., Ltd.) 3 and surface epoxy modification 1%) A pellet-shaped resin composition was obtained in the same manner as in Example 4 except that 10 parts by weight was blended.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. In addition, Izod impact strength and Vicat softening temperature were measured using an injection test piece, and the number of aggregates having a diameter of 1 μm or more of latex rubber in a transmission electron microscope was measured using a compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 6
A pellet-shaped resin composition was prepared in the same manner as in Example 3 except that a different-direction twin screw extruder equipped with a full flight screw was used instead of the different-direction twin screw extruder equipped with a strong kneading type screw. Got.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Example 7
Instead of core-shell type latex rubber (product name: Metabrene W-450A, manufactured by Mitsubishi Rayon Co., Ltd.), core-shell type latex rubber (Mitsubishi Rayon, whose core component is a silicone / acrylic rubber copolymer and whose shell component is polymethyl methacrylate) A pellet-shaped resin composition was obtained in the same manner as in Example 1 except that the product name, Metabrene SRK200) was used.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had high Vicat softening point and Izod impact strength, and was excellent in heat resistance and impact resistance.

Comparative Example 1
Pellets were obtained in the same manner as in Example 1 except that extrusion was performed only with a poly-3-hydroxybutyrate polymer (manufactured by PHB Industrial S / A, trade name Biocycle 1000).

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained pellets were measured, and the Izod impact strength and Vicat softening temperature of the injection specimen were measured. Table 1 shows the results.

  The obtained resin had low Izod impact strength and was inferior in impact resistance.

Comparative Example 2
A core-shell type latex rubber (Mitsubishi Rayon Co., Ltd., trade name Metabrene W-450A) is used instead of the core-shell type latex rubber (Mitsubrene W-450A). The core component is a styrene-butadiene copolymer rubber and the shell component is polymethyl methacrylate. A pellet-shaped resin composition was obtained in the same manner as in Example 1 except that Rayon Co., Ltd., trade name Metabrene C-223A) was used.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had low Izod impact strength and was inferior in impact resistance.

Comparative Example 3
A pellet-shaped resin composition was obtained in the same manner as in Example 1 except that the resin temperature immediately after discharge from the different-direction twin screw extruder was 178 ° C., except that the resin temperature was 250 ° C.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had a low crystallization temperature of 92 ° C. and poor moldability, low Izod impact strength, and poor impact resistance.

Comparative Example 4
Instead of 70% by weight of poly-3-hydroxybutyrate polymer and 30% by weight of core-shell type latex rubber, 30% by weight of poly-3-hydroxybutyrate polymer and 70% by weight of core-shell type latex rubber were used. Except for the above, a pellet-shaped resin composition was obtained in the same manner as in Example 1.

  The crystallization temperature, crystal melting point, and weight average molecular weight of the chloroform-dissolved component of the obtained resin composition were measured. Moreover, the Izod impact strength and Vicat softening temperature were measured using the injection test piece, and the number of aggregates having a diameter of 1 μm or more of the core-shell type latex rubber in the transmission electron microscope observation was further measured using the compression test piece. The results are shown in Table 1.

  Table 2 shows the measurement results of dynamic viscoelasticity obtained using test pieces obtained by compression molding only the core-shell type latex rubber at 180 ° C.

  The obtained resin composition had a low Vicat softening temperature of 70 ° C. and was inferior in heat resistance.

Claims (4)

50-99% by weight of a poly 3-hydroxybutyrate polymer, a core-shell type latex rubber 50 in which the core component is an acrylic rubber and / or a silicone / acrylic rubber copolymer, and the shell component is polymethyl methacrylate. A resin composition comprising ˜1% by weight and satisfying the requirements shown in the following (a) and (b).
(A) Crystal in a differential scanning calorimeter when heated from room temperature to 180 ° C. at a temperature increase rate of 80 ° C./min, held at 180 ° C. for 1 minute, and then cooled at a temperature decrease rate of 10 ° C./min The conversion temperature is 110 ° C. or higher and 170 ° C. or lower.
(B) The polystyrene-equivalent weight average molecular weight (Mw) when the chloroform-dissolved component is measured by gel permeation chromatography is 100,000 or more and 3000000 or less.   Core-shell type having a tensile storage elastic modulus (E ′) of 1 MPa or more and 100 MPa or less at a measurement temperature of 0 ° C. and a measurement frequency of 10 Hz, and a temperature showing a maximum value of loss tangent (tan δ) being −50 ° C. or more and 0 ° C. or less. The resin composition according to claim 1, wherein the resin composition is latex rubber.   The composition further comprises 0.1 to 30 parts by weight of a phthalic acid plasticizer with respect to 100 parts by weight of the total amount of the poly-3-hydroxybutyrate polymer and the core-shell type latex rubber. The resin composition according to either 1 or 2. When an ultra-thin section of a compression molded specimen is observed with a transmission electron microscope, the core-shell type latex rubber does not form a continuous phase, and an aggregate of core-shell type latex rubber having a diameter of 1 μm or more is formed. The resin composition according to claim 1, wherein the resin composition is less than 2 (pieces / 100 μm ² ).