JP7742845B2 - Resin composition and molded article thereof - Google Patents

Description

The present invention relates to a resin composition containing a poly(3-hydroxyalkanoate) resin and a molded article thereof.

In recent years, environmental issues caused by discarded plastic have come into the spotlight, and it has become clear that large amounts of plastic, particularly plastic dumped in the ocean or flowing into the sea via rivers, are drifting in the oceans on a global scale. Because such plastic retains its shape for long periods of time, it has been pointed out that it has an impact on the ecosystem, such as trapping and capturing marine life (a practice known as ghost fishing), and that if ingested by marine life, it can become lodged in the digestive tract, causing feeding disorders.

Furthermore, it has been pointed out that microplastics, which are plastics that break down and break down into tiny particles due to ultraviolet rays and other factors, absorb harmful compounds in the ocean, and when marine organisms ingest these, harmful substances are introduced into the food chain.

The use of biodegradable plastics is expected to be a solution to this type of marine pollution caused by plastics, but a report compiled by the United Nations Environment Programme in 2015 pointed out that plastics that can be biodegraded through compost, such as polylactic acid, cannot be expected to decompose in the short term in the cold ocean temperatures, and therefore cannot be used to combat marine pollution.

Microbial poly(3-hydroxyalkanoate) resins are materials that can biodegrade even in seawater, and are attracting attention as a material that can solve the above-mentioned problems. However, poly(3-hydroxyalkanoate) resins can sometimes have a distinctive odor that limits their applications.

Patent document 1 describes a biodegradable plastic made by adding a deodorizing agent such as hydrophobic zeolite to a biodegradable plastic such as 3-hydroxybutyrate and 3-hydroxyvalerate.

Japanese Patent Application Publication No. 7-310005

According to the method described in Patent Document 1, the odors of 3-hydroxybutyrate and 3-hydroxyvalerate can be suppressed to some extent, but the effect is not sufficient and there is room for improvement.
Furthermore, when a molded article is produced using the deodorizing agent (ABSCENTS-3000 provided by Union Showa Co., Ltd.) described in the examples of Patent Document 1, and then this is recycled and crushed to produce a new molded article, it has been found that the physical properties of the resin deteriorate, making it difficult to obtain a molded article of the same quality.

In view of the above-mentioned current situation, the present invention aims to provide a resin composition and molded articles thereof that suppress the odor characteristic of poly(3-hydroxyalkanoate)-based resins and have good recyclability.

After extensive research to solve the above problem, the inventors discovered that the above problem can be solved by blending a specific amount of specific porous particles into a poly(3-hydroxyalkanoate) resin, and thus completed the present invention.

That is, the present invention relates to a resin composition containing 100 parts by weight of a poly(3-hydroxyalkanoate) resin (A) and 0.1 to 10 parts by weight of porous particles (B), wherein the pore diameter of the porous particles (B) is 0.7 to 1.5 nm.
Preferably, the porous particles (B) have an average particle size of 0.1 to 10 μm.
Preferably, the porous particles (B) are hydrophobic zeolite.
Preferably, the poly(3-hydroxyalkanoate) resin (A) is a poly(3-hydroxybutyrate) resin.
Preferably, the poly(3-hydroxybutyrate)-based resin is at least one selected from the group consisting of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).
The present invention also relates to a molded article of the resin composition.
Preferably, the molded article is molded by injection molding, extrusion blow molding, or injection blow molding.

The present invention provides a resin composition and molded articles thereof that suppress the odor characteristic of poly(3-hydroxyalkanoate)-based resins and have good recyclability. Because the resin composition and molded articles thereof have good recyclability, even when they are remelted to produce a new resin composition or molded article, deterioration in their physical properties is suppressed. The resin composition and molded articles of the present invention can be used in a wide range of applications, including food, pharmaceuticals, and cosmetics, which are sensitive to odors.

The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

The resin composition according to this embodiment contains, as essential components, a poly(3-hydroxyalkanoate) resin (A) and specific porous particles (B). Hereinafter, the poly(3-hydroxyalkanoate) resin may be referred to as P3HA.

[Poly(3-hydroxyalkanoate)-based resin (A)]
The poly(3-hydroxyalkanoate) resin is a biodegradable aliphatic polyester, preferably an aliphatic polyester containing no aromatic ring. The poly(3-hydroxyalkanoate) resin may be one having no double bond.

The poly(3-hydroxyalkanoate) resin contains a 3-hydroxyalkanoate unit represented by the following general formula (1) as an essential repeating unit.
[-CHR-CH ₂ -CO-O-] (1)
In the general formula (1), R is an alkyl group represented by C _n H _2n+1 , where n is an integer of 1 or more and 15 or less.

The poly(3-hydroxyalkanoate) resin preferably contains 3-hydroxyalkanoate units represented by the general formula (1) in an amount of 50 mol% or more, and more preferably 70 mol% or more, of the total repeating units (100 mol%) constituting the resin.

The poly(3-hydroxyalkanoate) resin is preferably a resin containing 3-hydroxybutyrate (3HB) units as an essential repeating unit, ie, a poly(3-hydroxybutyrate) resin.
Examples of the poly(3-hydroxybutyrate)-based resin include poly(3-hydroxybutyrate) (P3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).

P3HA produced by microorganisms (microbially produced P3HA) is typically P3HA composed only of D-form (R-form) hydroxyalkanoate units. Among microbially produced P3HA, P3HB, P3HB3HH, P3HB3HV, P3HB3HV3HH, and P3HB4HB are preferred due to ease of industrial production, with P3HB, P3HB3HH, P3HB3HV, and P3HB4HB being more preferred.

When P3HA (especially microbially produced P3HA) contains 3-hydroxybutyrate (3HB) units, from the viewpoint of the balance between flexibility and strength, the monomer composition ratio is preferably such that the proportion of 3HB units out of all repeating units (100 mol%) constituting P3HA is 80 mol% or more and 99 mol% or less, and more preferably 85 mol% or more and 97 mol% or less. Having a proportion of 3HB units of 80 mol% or more improves the rigidity of P3HA and also tends to facilitate purification without excessively low crystallinity. On the other hand, having a proportion of 3HB units of 99 mol% or less tends to improve the flexibility of P3HA. The monomer composition ratio of P3HA can be measured by gas chromatography or the like (see, for example, WO 2014/020838).

Microorganisms that produce microbially produced P3HA are not particularly limited as long as they are capable of producing P3HA. For example, the first P3HB-producing bacterium was Bacillus megaterium, discovered in 1925. Other known natural microorganisms include Cupriavidus necator (formerly classified as Alcaligenes eutrophus and Ralstonia eutropha) and Alcaligenes latus, and P3HB accumulates intracellularly in these microorganisms.

In addition, bacteria known to produce copolymers of 3-hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB. In particular, with regard to P3HB3HH, in order to increase the productivity of P3HB3HH, Alcaligenes eutrophus AC32 strain (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)) into which genes for the P3HA synthase group have been introduced is more preferred, and microbial cells in which P3HB3HH has been accumulated within the cells by culturing these microorganisms under appropriate conditions are used. In addition to the above, genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used depending on the P3HA to be produced, or the culture conditions, including the type of substrate, may be optimized.

The molecular weight of P3HA is not particularly limited as long as it exhibits substantially sufficient physical properties for the intended application, but its weight-average molecular weight is preferably 50,000 or more and 3,000,000 or less, more preferably 100,000 or more and 1,000,000 or less, and even more preferably 200,000 or more and 700,000 or less. By setting the weight-average molecular weight to 50,000 or more, the mechanical strength of the molded body tends to be further improved. On the other hand, by setting the weight-average molecular weight to 3,000,000 or less, processability tends to be further improved, making molding easier.

The weight-average molecular weight can be measured using gel permeation chromatography (GPC) (Shodex GPC-101 manufactured by Showa Denko K.K.) with a polystyrene gel column (Shodex K-804 manufactured by Showa Denko K.K.) and chloroform as the mobile phase, and can be calculated as the molecular weight converted into polystyrene. A calibration curve is prepared using polystyrenes with weight-average molecular weights of 31,400, 197,000, 668,000, and 1,920,000. A column appropriate for measuring the molecular weight can be used for the GPC.

P3HA can be used alone or in combination of two or more types.

The content of P3HA in the resin composition according to this embodiment is not particularly limited, but is preferably 20% by weight or more, more preferably 30% by weight or more, even more preferably 40% by weight or more, even more preferably 60% by weight or more, and particularly preferably 70% by weight or more. By making the P3HA content 20% by weight or more, the biodegradability of the resin composition or molded article tends to be even better. The upper limit of the P3HA content is not particularly limited, but is preferably 100% by weight or less, more preferably 99% by weight or less, and even more preferably 98% by weight or less.

[Other resins]
The resin composition according to this embodiment may contain a resin other than P3HA (hereinafter, sometimes referred to as "other resin"). The other resin is not particularly limited as long as it does not significantly reduce the compatibility, moldability, or mechanical properties when molding the resin composition according to this embodiment. However, when the resin composition is used in an application requiring biodegradability, which is a characteristic of P3HA, it is preferably a biodegradable resin.

Examples of the other resins include aliphatic polyesters formed by the polycondensation of aliphatic diols and aliphatic dicarboxylic acids, and aliphatic-aromatic polyesters containing both aliphatic and aromatic compounds as monomers. Examples of the former include polyethylene succinate, polybutylene succinate (PBS), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (PBSA), polyethylene sebacate, and polybutylene sebacate. Examples of the latter include poly(butylene adipate-co-butylene terephthalate) (PBAT), poly(butylene sebacate-co-butylene terephthalate), poly(butylene azelate-co-butylene terephthalate), and poly(butylene succinate-co-butylene terephthalate) (PBST). The other resins may be used singly or in combination of two or more.

The content of the other resin in the resin composition according to this embodiment is not particularly limited, but is preferably 250 parts by weight or less, more preferably 100 parts by weight or less, even more preferably 50 parts by weight or less, and particularly preferably 20 parts by weight or less, relative to 100 parts by weight of P3HA. It may also be 10 parts by weight or less, or 5 parts by weight or less. There is no particular lower limit for the content of the other resin, and it may even be 0 parts by weight.

[Porous particles (B)]
The porous particles contained in the resin composition according to this embodiment have porosity, which allows them to adsorb odor-causing substances and provide deodorizing properties. The porous particles may be made of an organic material, an inorganic material, or an organic-inorganic hybrid material.

Examples of organic materials include polymeric porous particles, such as nylon particles, polyamide particles, acrylic particles, polymethyl methacrylate particles, polystyrene particles, silicone particles, cyclic silicone particles, urethane particles, polyethylene particles, and phospholipid particles. These particles may be crosslinked or non-crosslinked, but crosslinked particles are preferred because they are less likely to be destroyed by shear during molding.

Examples of such inorganic materials include activated carbon, activated clay, acid clay, natural zeolite, hydrophobic zeolite, hydrophilic zeolite, silica gel, bentonite, smectite, mica, talc, pyroferrite, vermiculite, chlorite, kaolinite and serpentine, silica, titanium oxide, a mixture of magnesium oxide and silicon dioxide, and a complex of magnesium oxide and silicon dioxide.

Among the porous particles, one or more selected from the group consisting of hydrophobic zeolite, hydrophilic zeolite, and silica gel are preferably used, as they have excellent deodorizing properties, particularly against odors specific to poly(3-hydroxyalkanoate) resins. Furthermore, hydrophobic zeolite is even more preferred from the standpoint of compatibility with P3HA.

Zeolite is an inorganic compound mainly composed of tetrahedral coordinated SiO ₂ and Al ₂ O _3. The hydrophobic zeolite is a zeolite that contains a large amount of SiO ₂ and has a SiO ₂ /Al ₂ O ₃ molar ratio of 35 or more.

The inventors have discovered that, among the above-mentioned porous particles, porous particles with a pore diameter of 0.7 nm or more and 1.5 nm or less are particularly excellent at deodorizing the odors specific to poly(3-hydroxyalkanoate)-based resins, and are less likely to inhibit the recyclability of poly(3-hydroxyalkanoate)-based resins. If the pore diameter is less than 0.7 nm or more than 1.5 nm, the deodorizing effect per unit amount of porous particles decreases, making it necessary to increase the amount of porous particles added to achieve the desired deodorizing effect. As a result, the porous particles tend to accelerate the decomposition of poly(3-hydroxyalkanoate)-based resins, and recycling can easily cause the physical properties of the resin composition or molded article to deteriorate.

The pore diameter of the porous particles is preferably 0.7 nm or more and 1.2 nm or less, more preferably 0.7 nm or more and 1.0 nm or less, and particularly preferably 0.8 nm or more and 1.0 nm or less.

The pore diameter of the porous particles is a value measured by a constant volume gas adsorption method. Examples of adsorbed gases used in the constant volume gas adsorption method include nitrogen, carbon dioxide, methane, and hydrogen.

The particle size of the porous particles is not particularly limited, but it is preferable that the average particle size be 0.1 μm or more and 10 μm or less. By making the average particle size 0.1 μm or more, the dispersibility of the porous particles in the poly(3-hydroxyalkanoate) resin is improved, and the deodorizing effect tends to be improved. On the other hand, by making the average particle size 10 μm or less, the mechanical strength of the molded body tends to be improved. The average particle size is more preferably 0.3 μm or more and 8 μm or less, and even more preferably 0.5 μm or more and 6 μm or less.

The average particle diameter of the porous particles is a value observed using a scanning electron microscope (SEM). 100 or more particles that are not overlapping with other particles are selected, the lengths of the major and minor axes of each particle are measured, and the arithmetic mean of these particle diameters is used as the particle diameter of each particle. The arithmetic mean of these particle diameters can then be calculated as the average particle diameter.

The amount of the porous particles is 0.1 to 10 parts by weight per 100 parts by weight of the poly(3-hydroxyalkanoate) resin (A). If the amount of porous particles is less than 0.1 parts by weight, the deodorizing effect of the porous particles cannot be fully achieved. On the other hand, if the amount exceeds 10 parts by weight, the porous particles tend to cause the poly(3-hydroxyalkanoate) resin to decompose more easily, and the physical properties of the resin composition or molded article tend to deteriorate during recycling. The amount of the porous particles is preferably 0.5 to 8 parts by weight, more preferably 1.0 to 7 parts by weight, and even more preferably 2.0 to 6 parts by weight.

(Additives)
The resin composition according to the present embodiment may contain additives as long as the effects of the invention are not impaired. Examples of additives that can be used depending on the purpose include nucleating agents, lubricants, plasticizers, antistatic agents, flame retardants, conductive agents, heat insulating agents, crosslinking agents, antioxidants, ultraviolet absorbers, colorants, inorganic fillers, organic fillers, and hydrolysis inhibitors. Biodegradable additives are particularly preferred.

Examples of nucleating agents include pentaerythritol, orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, and boron nitride. Among these, pentaerythritol is preferred due to its particularly excellent effect in promoting the crystallization of poly(3-hydroxyalkanoate) resins. The amount of nucleating agent used is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, and even more preferably 0.7 to 1.5 parts by weight, per 100 parts by weight of poly(3-hydroxyalkanoate) resin. Furthermore, one type of nucleating agent or two or more types may be used, and the usage ratio can be adjusted appropriately depending on the purpose.

Examples of lubricants include behenamide, oleamide, erucamide, stearamide, palmitamide, N-stearylbehenamide, N-stearylerucamide, ethylenebisstearamide, ethylenebisoleamide, ethylenebiserucamide, ethylenebislauricamide, ethylenebiscapricamide, p-phenylenebisstearamide, and polycondensates of ethylenediamine, stearic acid, and sebacic acid. Among these, behenamide and erucamide are preferred due to their particularly excellent lubricating effect on poly(3-hydroxyalkanoate) resins. The amount of lubricant used is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and even more preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of the poly(3-hydroxyalkanoate) resin. The lubricant may be used alone or in combination of two or more kinds, and the ratio of use can be adjusted appropriately depending on the purpose.

Examples of plasticizers include glycerin ester compounds, citrate ester compounds, sebacate compounds, adipate compounds, polyether ester compounds, benzoate ester compounds, phthalate ester compounds, isosorbide ester compounds, polycaprolactone compounds, and dibasic acid ester compounds. Among these, glycerin ester compounds, citrate ester compounds, sebacate compounds, and dibasic acid ester compounds are preferred due to their particularly excellent plasticizing effect on poly(3-hydroxyalkanoate) resins. Examples of glycerin ester compounds include glycerin diacetomonolaurate. Examples of citrate ester compounds include acetyl tributyl citrate. Examples of sebacate compounds include dibutyl sebacate. Examples of dibasic acid ester compounds include benzyl methyl diethylene glycol adipate. The amount of plasticizer used is not particularly limited, but is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and even more preferably 3 to 10 parts by weight, relative to 100 parts by weight of the total poly(3-hydroxyalkanoate) resin. One type of plasticizer may be used, or two or more types may be used, and the usage ratio can be adjusted appropriately depending on the purpose.

[Resin composition]
The resin composition according to the present embodiment can be easily produced using a known melt kneader as long as it is an apparatus that can heat and knead the poly(3-hydroxyalkanoate) resin (A) to a temperature equal to or higher than the melting point thereof. For example, a method can be used in which the poly(3-hydroxyalkanoate) resin (A), the porous particles (B), and, if necessary, other components are melt-kneaded using an extruder, a roll mill, a Banbury mixer, or the like to form pellets, which are then subjected to molding; or a method can be used in which a masterbatch of a high concentration of the porous particles (B) is prepared in advance, which is melt-kneaded with the poly(3-hydroxyalkanoate) resin (A) in a desired ratio, and then subjected to molding.

The poly(3-hydroxyalkanoate) resin (A) and the porous particles (B) may be added to the kneader simultaneously, or the poly(3-hydroxyalkanoate) resin (A) may be melted first and then the porous particles (B) may be added.

[Molded body]
The resin composition according to this embodiment can be used to produce a molded article by various molding methods such as extrusion molding, injection molding, calendar molding, injection blow molding, and extrusion blow molding.
The resin composition according to this embodiment can be used to produce a molded article, particularly by injection molding, extrusion blow molding, or injection blow molding.

(Method for producing blow molded or injection molded articles)
The molded article according to this embodiment can be produced by a known blow molding method or injection molding method after obtaining pellets as needed.

First, poly(3-hydroxyalkanoate) resin (A), porous particles (B), and other components, if necessary, are added and melt-kneaded using an extruder, kneader, Banbury mixer, roll, or the like to produce a resin composition, which is then extruded into strands and cut to obtain pellets in particle shapes such as cylindrical, elliptical, spherical, cubic, and rectangular prism shapes. The pellets produced are then thoroughly dried at 40-80°C to remove moisture, and are then preferably subjected to blow molding or injection molding.

The temperature at which the melt-kneading is carried out cannot be generally defined as it depends on the melting point, melt viscosity, etc. of the resin used, but it is preferable that the resin temperature of the melt-kneaded product at the die outlet is 135 to 200°C, more preferably 140 to 190°C, even more preferably 145 to 180°C, and particularly preferably 150 to 170°C. If the resin temperature of the melt-kneaded product is below 135°C, the poly(3-hydroxyalkanoate) resin may remain unmelted, and if it exceeds 200°C, the poly(3-hydroxyalkanoate) resin may undergo thermal decomposition.

The pellets thus produced can then be subjected to blow molding or injection molding to form a blow molded or injection molded body.

Blow molding is a molding method that can produce hollow molded objects such as bottles by blowing air into plasticized resin material. Any of the following methods can be used: extrusion blow molding, multi-layer extrusion blow molding, injection blow molding, stretch blow molding, etc.

Injection molding is a method in which a heated and molten resin composition is injected into a mold, the resin composition is cooled and solidified inside the mold, the mold is opened, and the molded article is demolded to obtain a molded article. Injection molding methods that can be used include those commonly used when molding thermoplastic resins, as well as gas-assisted molding, injection compression molding, and injection blow molding (including one-step and two-step methods). Other methods that can be used include in-mold molding, gas press molding, two-color molding, sandwich molding, push-pull molding, and SCORIM molding. However, usable injection molding methods are not limited to the above methods.

The molded article according to this embodiment is not particularly limited, but examples include films, sheets, tubes, plates, rods, packaging materials (e.g., bags), containers (e.g., bottle containers), parts, etc. From the perspective of preventing marine pollution, the molded article is preferably a packaging material or a container.

The present invention will be explained in detail below using examples, but the technical scope of the present invention is not limited to these examples.

(Raw materials used)
The raw materials used in the examples and comparative examples are shown in Table 1.

Example 1
(Preparation of PHBH Blends)
100 parts by weight = 10 kg. Using a 75 L Super Mixer manufactured by Kawata Corporation, 10 kg of PHBH, 100 g of PETL, 50 g of EA, 50 g of BA, and 100 g of zeolite A were charged and stirred at 300 rpm for 3 minutes to obtain a PHBH blend.

(compounding)
A TEM26SS (L/D = 60) manufactured by Toshiba Machine was used, and the barrel temperature was set to 150°C and the screw rotation speed to 100 rpm. The PHBH blend was fed from the base of the screw at a rate of 10 kg/hr, passed through a water tank filled with hot water at 45°C to solidify the strands, and cut into pellets using a pelletizer.

(Acquisition of injection molded products)
Using a Toyo Machinery & Metal injection molding machine Si-100V, nozzle/T1/T2/T3/T4 = 155/145/135/125/115°C, an injection speed of 20 mm/sec, and a mold temperature of 35°C, bottles having a diameter of 5 cm, a height of 10 cm, and a thickness of 1 mm were obtained from the pellets. Immediately after molding, the bottles were sealed with lids.

(Odor evaluation)
The sealed bottle was left to stand at 23°C for 48 hours, then placed in a 40°C oven for 24 hours, the lid was removed, and five people were asked to smell the odor and evaluate it based on the following criteria. The results are shown in Table 2.
××: 5 out of 5 people could clearly detect the odor, but it was unpleasant. ×: 5 out of 5 people could clearly detect the odor. △: 5 out of 5 people could just barely detect the odor. 〇: Some out of 5 people could detect the odor and some could not, and even if they could detect the odor, it was not bothersome. ◎: None of the 5 people could detect the odor.

(Recyclability evaluation)
The resulting bottles were crushed, and the crushed product was blended with the pellets in a 20:80 ratio (crushed product:pellets, by weight). The process of obtaining bottles was repeated twice using the same method as in "Obtaining injection-molded products" described above. Whether or not bottles equivalent to those before crushing could be obtained without changing the molding conditions was evaluated based on the following criteria. The results are shown in Table 2.
Good: Equivalent bottles can be obtained without changing molding conditions. Bad: Equivalent bottles cannot be obtained without changing molding conditions. Fluidity is too high, resulting in flashing.

[Examples 2 to 3, Comparative Examples 1 to 5]
Pellets and bottles were prepared in the same manner as in Example 1, except that the type and/or amount of zeolite was changed according to the formulation shown in Table 2.
The resulting bottles were evaluated for odor and recyclability in the same manner as in Example 1, and the results are shown in Table 2.

The following can be seen from Table 2: The bottles obtained in Examples 1 to 3 had reduced odor and were also highly recyclable.
On the other hand, Comparative Example 1 used the same porous particles as Examples 1 to 3, but the blended amount was large, resulting in insufficient recyclability. Comparative Example 2 did not blend any porous particles, and Comparative Examples 3 and 4 blended the same type of porous particles as those described in Patent Document 1, but all of them had an odor. Comparative Example 5 blended the same type of porous particles as those described in Patent Document 1 in a larger amount than Comparative Examples 3 and 4. Although the odor was suppressed, the recyclability was insufficient.

Claims (7)

The composition contains 100 parts by weight of a poly(3-hydroxyalkanoate) resin (A) and 0.1 to 10 parts by weight of porous particles (B),
The resin composition, wherein the porous particles (B) have a pore size of 0.7 to 1.5 nm. A resin composition according to claim 1, wherein the average particle diameter of the porous particles (B) is 0.1 to 10 μm. A resin composition described in claim 1 or 2, wherein the porous particles (B) are hydrophobic zeolite. A resin composition described in any one of claims 1 to 3, wherein the poly(3-hydroxyalkanoate)-based resin (A) is a poly(3-hydroxybutyrate)-based resin. The resin composition described in claim 4, wherein the poly(3-hydroxybutyrate)-based resin is at least one selected from the group consisting of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate). A molded article made from the resin composition described in any one of claims 1 to 5. The molded article according to claim 6 , which is molded by injection molding, extrusion blow molding, or injection blow molding.