Granular body, method for producing same, and thermoplastic resin composition

Abstract

This granular body contains cross-linked resin particles (A) and an aggregation preventing agent (B), and has a median size of 20 µm to 10 mm. The cross-linked resin particles (A) contain a polyhydroxyalkanoate-based resin, and has a gel fraction of 50% or more and a volume average particle size of 0.1-10 µm. The granular body can be produced by preparing an aqueous dispersion liquid containing the cross-linked resin particles (A) and the aggregation preventing agent (B), and spraying and drying the aqueous dispersion liquid. This thermoplastic resin composition can be formed by including the granular body and a thermoplastic resin (C).

Description

Powder and granule, its manufacturing method, and thermoplastic resin composition

[0001] The present invention relates to a powder or granule containing crosslinked resin particles, a method for producing the same, and a thermoplastic resin composition containing the powder or granule.

[0002] It has been known that introducing a crosslinked structure into a resin can improve the resin's hardness, heat resistance, solvent resistance, etc. Small resin particles composed of resins with such crosslinked structures are used in a variety of applications, such as modifiers for thermoplastic resins, spacers, antiblocking agents, and matting agents.

[0003] Known resin materials constituting such crosslinked resin particles include acrylic resins, acrylic silicone resins, polystyrene, and the like (see, for example, Patent Documents 1 and 2).

[0004] On the other hand, plastic waste is a burden on the global environment, affecting ecosystems, emitting harmful gases when burned, and contributing to global warming due to the large amount of heat generated by combustion. Therefore, there has been active development of biodegradable plastics as a material that can solve these problems.

[0005] Patent Document 3 describes crosslinking of poly(3-hydroxyalkanoate), a type of biodegradable plastic, by melt-kneading the resin in the presence of an organic peroxide. However, it describes that the crosslinked resin produced by melt-kneading in this way is used to form films or sheets, and does not describe at all the production of small particle size crosslinked resin particles.

[0006] JP 2009-56770 A JP 2003-82191 A International Publication No. 2019 / 022008

[0007] To date, small-sized crosslinked resin particles composed of biodegradable plastics and exhibiting biodegradability have not been known. The present inventors have succeeded in producing crosslinked resin particles composed of polyhydroxyalkanoate resin, a biodegradable resin, in an aqueous dispersion. These crosslinked resin particles are expected to address the problem of plastic waste and be useful as environmentally friendly crosslinked resin particles. However, when attempting to separate the crosslinked resin particles from the aqueous dispersion, the crosslinked resin particles adhere to each other and aggregate as the water evaporates, forming rubber-like sheets or lumpy solids, making it difficult to separate them in an easily handleable form.

[0008] In view of the above-mentioned current situation, an object of the present invention is to provide crosslinked resin particles composed of a polyhydroxyalkanoate resin in a form that is easy to handle. Another object of the present invention is to provide a thermoplastic resin composition that can be used to form molded articles with improved impact resistance and / or tear strength.

[0009] As a result of extensive research, the present inventors have found that by preparing an aqueous dispersion in which an anti-aggregation agent is dispersed together with crosslinked resin particles containing a polyhydroxyalkanoate resin, and spray-drying the aqueous dispersion, it is possible to obtain a powder containing crosslinked resin particles which has good handleability, and that by blending the powder with a thermoplastic resin, it is possible to improve the impact resistance and / or tear strength of the thermoplastic resin, thereby completing the present invention.

[0010] Specifically, the present invention relates to a powder or granule having a median diameter of 20 μm to 10 mm, the powder or granule containing crosslinked resin particles (A) and an anti-agglomerating agent (B), the crosslinked resin particles (A) containing a polyhydroxyalkanoate resin, a gel fraction of 50% or more, and a volume average particle diameter of 0.1 μm to 10 μm. The present invention also relates to a method for producing the powder or granule, the method comprising the steps of preparing an aqueous dispersion containing the crosslinked resin particles (A) and the anti-agglomerating agent (B), and spray-drying the aqueous dispersion. The present invention also relates to a thermoplastic resin composition containing the powder or granule and a thermoplastic resin (C).

[0011] According to the present invention, crosslinked resin particles containing a polyhydroxyalkanoate resin can be provided in a form that is easy to handle. According to a preferred embodiment of the present invention, an anti-agglomerating agent coats at least a portion of the surface of a powder or granule, which is a secondary aggregate of crosslinked resin particles, thereby reducing the exposed surface area of ​​the crosslinked resin particles in the powder or granule, thereby suppressing adhesion or aggregation of the crosslinked resin particles and producing a powder or granule with high fluidity and easy handling. According to a preferred embodiment of the present invention, adhesion or aggregation between crosslinked resin particles can be suppressed even when the proportion of crosslinked resin particles in the powder or granule is increased. Furthermore, by blending the powder or granule of the present invention with a thermoplastic resin, the impact resistance and / or tear strength of the thermoplastic resin can be improved. According to a preferred embodiment of the present invention, the impact resistance and / or tear strength can be increased without impairing the compounding flexibility of the thermoplastic resin composition or the physical properties of the composition.

[0012] Micrograph of the powder and granules obtained in Example 1 (magnification: 1500) Micrograph of the powder and granules obtained in Example 2 (magnification: 3500) Micrograph of the powder and granules obtained in Example 4 (magnification: 8000) Micrograph of the powder and granules obtained in Example 9 (magnification: 2000) Micrograph of the powder and granules obtained in Example 11 (magnification: 3500) Micrograph of the powder and granules obtained in Example 12 (magnification: 2200) Micrograph of the powder and granules obtained in Example 16 (magnification: 2000)

[0013] Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the following embodiment. The powder according to this embodiment contains at least crosslinked resin particles (A) and an anti-aggregation agent (B). The powder has a particle size within a specific range, and therefore has good handleability. First, the crosslinked resin particles (A) will be described.

[0014] <Crosslinked Resin Particles (A)> The crosslinked resin particles (A) are particles composed of a polyhydroxyalkanoate resin as a main resin component. Hereinafter, the polyhydroxyalkanoate resin may be abbreviated as "PHA."

[0015] <PHA> "PHA" is a general term for polymers containing hydroxyalkanoic acid as a monomer unit, and is generally biodegradable. PHA is an aliphatic polyester, preferably a polyester not containing an aromatic ring. The PHA preferably contains 50 mol% or more of hydroxyalkanoic acid repeating units out of all monomer repeating units (100 mol%), more preferably 60 mol% or more, and even more preferably 70 mol% or more. There is no particular upper limit, and it is sufficient as long as it is 100 mol% or less.

[0016] The PHA is not particularly limited, but examples thereof include polyglycolic acid, poly(3-hydroxyalkanoate)-based resins, and poly(4-hydroxyalkanoate)-based resins. Only one type of PHA may be used, or two or more types may be used in combination. The PHA preferably contains a poly(3-hydroxyalkanoate)-based resin, and may be composed solely of a poly(3-hydroxyalkanoate)-based resin. Hereinafter, poly(3-hydroxyalkanoate)-based resin may be abbreviated as "P3HA."

[0017] The P3HA has the formula: [—CHR—CH ２ 3-hydroxyalkanoic acid repeating units represented by the formula: —CO—O— (wherein R is C ｎ H ２ｎ＋１ where n is an integer of 1 or more and 15 or less.) as an essential repeating unit. The P3HA preferably contains 50 mol % or more of the 3-hydroxyalkanoic acid repeating units, more preferably 60 mol % or more, and even more preferably 70 mol % or more of the total monomer repeating units (100 mol %). There is no particular upper limit, as long as it is 100 mol % or less.

[0018] P3HA is not particularly limited and may be a homopolymer containing the repeating unit described above, or a copolymer containing the repeating unit described above. Examples of the copolymer include copolymers of 3-hydroxybutanoic acid (hereinafter sometimes referred to as "3HB") and one or more monomers selected from the group consisting of 3-hydroxypropionic acid, 3-hydroxypentanoic acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, 3-hydroxynonanoic acid, 3-hydroxydecanoic acid, 3-hydroxyundecanoic acid, 3-hydroxydodecanoic acid, 3-hydroxytridecanoic acid, 3-hydroxytetradecanoic acid, 3-hydroxyhexadecanoic acid, and 3-hydroxyoctadecanoic acid. Other examples of the copolymer include copolymers of 3HB and one or more monomers selected from the group consisting of 4-hydroxybutanoic acid, 4-hydroxypentanoic acid, 4-hydroxyhexanoic acid, 4-hydroxyheptanoic acid, 4-hydroxyoctanoic acid, 4-hydroxynonanoic acid, 4-hydroxydecanoic acid, 4-hydroxyundecanoic acid, 4-hydroxydodecanoic acid, 4-hydroxytridecanoic acid, 4-hydroxytetradecanoic acid, 4-hydroxyhexadecanoic acid, and 4-hydroxyoctadecanoic acid.

[0019] Specific examples of the copolymer include, but are not limited to, poly(3-hydroxybutyrate) (abbreviation: P3HB), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (abbreviation: P3HB3HH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (abbreviation: P3HB4HB), etc. As P3HA, only one type may be used, or two or more types may be used in combination.

[0020] As used herein, "poly(X-co-Y)" refers to a copolymer containing X repeating units and Y repeating units, obtained by copolymerizing a monomer from which the X repeating units are derived and a monomer from which the Y repeating units are derived. Furthermore, during the production of P3HA, a trace amount (less than 1 mol%) of a monomer may be copolymerized, but if this does not significantly affect the physical properties of the resulting P3HA, that monomer is considered to be uncopolymerized, and the product will be referred to by a name that does not include that monomer.

[0021] P3HA can be produced by microorganisms. Such microbially produced P3HA is usually P3HA composed only of D-form (R-form) hydroxyalkanoic acid repeating units. Among microbially produced P3HAs, P3HB, P3HB3HH, and P3HB4HB are preferred, with P3HB3HH and P3HB4HB being more preferred, due to ease of industrial production.

[0022] When P3HA contains 3-hydroxybutanoic acid (3HB) repeating units, from the viewpoint of the balance between flexibility and strength, the composition ratio of 3HB repeating units in all monomer repeating units (100 mol%) is preferably 60 to 99 mol%, more preferably 61 to 97 mol%, and even more preferably 62 to 95 mol%. Having a composition ratio of 3HB repeating units of 60 mol% or more facilitates handling of the crosslinked resin particles (A) or the resin particles before crosslinking treatment. On the other hand, having a composition ratio of 3HB repeating units of 99 mol% or less tends to ensure the flexibility of the crosslinked resin particles (A). The monomer composition ratio of P3HA can be measured by gas chromatography or the like (see, for example, WO 2014 / 020838). Two or more types of P3HA having different composition ratios of 3HB repeating units may be used in combination.

[0023] The microorganism that produces P3HA is not particularly limited as long as it has the ability to produce 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, Ralstonia eutropha) and Alcaligenes latus. In these microorganisms, P3HB accumulates intracellularly.

[0024] Known examples of bacteria that produce copolymers of 3HB and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HH, and Alcaligenes eutrophus, which produces poly(3-hydroxybutyrate-co-4-hydroxybutyrate). In particular, Alcaligenes eutrophus AC32 (FERM BP-6038) (T. Fukui, Y. Doi, J. Bacteriol., 179, pp. 4821-4830 (1997)), into which genes encoding P3HA synthases have been introduced, is preferred for increasing P3HB3HH productivity. Microbial cells obtained by culturing such microorganisms under appropriate conditions and allowing P3HA to accumulate within the cells 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 culture conditions, including the type of substrate, may be optimized.

[0025] The molecular weight of the PHA is not particularly limited, but the weight-average molecular weight is preferably 50,000 to 3,000,000, more preferably 100,000 to 2,000,000, and more preferably 150,000 to 1,500,000. By setting the weight-average molecular weight to 50,000 or more, it is possible to avoid the tendency for the crosslinked resin particles (A) to have a low strength or to be sticky due to low molecular weight components. On the other hand, by setting the weight-average molecular weight to 3,000,000 or less, it is possible to facilitate the production and handling of the PHA. The weight-average molecular weight is a value measured before the PHA is subjected to a crosslinking treatment.

[0026] The weight-average molecular weight can be measured using gel permeation chromatography (GPC) (Shimadzu Corporation's "High Performance Liquid Chromatograph 20A System"), using polystyrene gel (Showa Denko K.K.'s "K-G 4A" or "K-806M" or the like) as a column, and chloroform as a mobile phase, and can be determined as a molecular weight converted into polystyrene. In this case, a calibration curve can be prepared using polystyrenes with weight-average molecular weights of 31,400, 197,000, 668,000, and 1,920,000. As the column for the GPC, a column appropriate for measuring the molecular weight can be used.

[0027] <Gel Fraction> The crosslinked resin particles (A) have a crosslinked structure in which molecular chains of PHA are bonded to each other. Because the crosslinked resin particles (A) have a certain amount or more of such crosslinked structure, they exhibit a high gel fraction, specifically, a gel fraction of 50% or more. Such a high gel fraction can improve the hardness, heat resistance, solvent resistance, etc. of the resin particles containing PHA. Furthermore, blending the crosslinked resin particles (A) into a thermoplastic resin can improve the mechanical strength, such as impact strength and tear strength, of the thermoplastic resin.

[0028] From the viewpoint of such improvements, the gel fraction value is preferably 60% or more, more preferably 70% or more, even more preferably 75% or more, and particularly preferably 80% or more. It may also be 85% or more, or even 90% or more. The upper limit of the gel fraction is not particularly limited as long as it is 100% or less. From the viewpoint of production efficiency of the crosslinked resin particles (A), however, it is preferably 99.5% or less, more preferably 99% or less. It may also be 98% or less, 97% or less, or 96% or less.

[0029] The gel fraction is a value measured as follows. A dried product of crosslinked resin particles (A) is added to chloroform so that the concentration becomes 0.7% by weight, and the mixture is dissolved at 60°C for 30 minutes to obtain a chloroform solution. After that, the mixture is left to stand at room temperature for 3 hours, and the chloroform solution is filtered through a membrane filter with a pore size of 0.45 μm. The gel remaining on the filter is dried, and the weight of the filter is measured, and the gel fraction is calculated using the following formula: Gel fraction (%) = [(weight of filter including dried gel - weight of filter only) / weight of crosslinked resin particles used in measurement] x 100

[0030] <Volume Average Particle Diameter> The crosslinked resin particles (A) have a volume average particle diameter in the range of 0.1 μm to 10 μm. By having such a particle diameter, a powder having a particle diameter within the specific range according to the present embodiment can be formed, and the powder can be used for various applications as described below. Furthermore, the mechanical strength of thermoplastic resins, such as impact strength and tear strength, can be improved. From the viewpoint of practical use, the lower limit of the particle diameter is preferably 0.2 μm or more, more preferably 0.3 μm or more, and even more preferably 0.5 μm or more. Furthermore, from the viewpoint of productivity (such as PHA production and crosslinking treatment), the upper limit of the particle diameter is preferably 8 μm or less, more preferably 5 μm or less.

[0031] The volume average particle diameter is a value measured when the crosslinked resin particles (A) are dispersed in an aqueous solvent. A general-purpose measuring device can be used as the measuring device, and an example of such a device is Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd.

[0032] <Peroxide> The crosslinking type of the crosslinked resin particles (A) is not particularly limited, but it is preferable that the crosslinking is performed using a peroxide. When a peroxide is used, radicals generated by decomposition of the peroxide act on PHA molecules to directly bond PHA molecular chains to each other, thereby forming the crosslinked structure.

[0033] When the crosslinked resin particles (A) are crosslinked using a peroxide, an aqueous dispersion containing the crosslinked resin particles (A) may contain substances derived from the peroxide used (e.g., decomposition products of the peroxide and unreacted peroxide). Alternatively, substances derived from the peroxide used may adhere to the surface of the resulting crosslinked resin particles (A). That is, when the crosslinked resin particles (A) are crosslinked using a peroxide, the crosslinked resin particles (A) or the powdery or thermoplastic resin composition according to this embodiment may contain substances derived from the peroxide. Therefore, when the crosslinked resin particles (A) or the powdery or thermoplastic resin composition according to this embodiment are analyzed and a substance derived from the peroxide is detected, it can be determined that the crosslinked resin particles (A) are crosslinked using a peroxide.

[0034] The peroxide may be an organic peroxide or an inorganic peroxide, but is preferably an organic peroxide because it can increase the gel fraction more efficiently.

[0035] As the organic peroxide, it is preferable to use at least one selected from the group consisting of diacyl peroxides, alkyl peroxy esters, dialkyl peroxides, hydroperoxides, peroxyketals, peroxycarbonates, and peroxydicarbonates, taking into consideration the heating temperature and time during the crosslinking treatment.

[0036] Specific examples of such organic peroxides include butyl peroxy neododecanoate, octanoyl peroxide, dilauroyl peroxide, succinic peroxide, a mixture of toluoyl peroxide and benzoyl peroxide, benzoyl peroxide, bis(butylperoxy)trimethylcyclohexane, butyl peroxylaurate, dimethyldi(benzoylperoxy)hexane, bis(butylperoxy)methylcyclohexane, bis(butylperoxy)cyclohexane, and butylperoxybenzo ester, butyl bis(butylperoxy)valerate, dicumyl peroxide, di-t-hexyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxymethyl monocarbonate, t-pentylperoxymethyl monocarbonate, t-hexylperoxymethyl monocarbonate, t-heptylperoxymethyl monocarbonate, t-octylperoxymethyl monocarbonate, 1 , 1,3,3-tetramethylbutylperoxymethyl monocarbonate, t-butylperoxyethyl monocarbonate, t-pentylperoxyethyl monocarbonate, t-hexylperoxyethyl monocarbonate, t-heptylperoxyethyl monocarbonate, t-octylperoxyethyl monocarbonate, 1,1,3,3-tetramethylbutylperoxyethyl monocarbonate, t-butylperoxy n-propyl monocarbonate, t-pentylperoxy n-propyl monocarbonate, t-hexylperoxy peroxy isopropyl monocarbonate, t-heptylperoxy isopropyl monocarbonate, t-octylperoxy isopropyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy isopropyl monocarbonate, t-butylperoxy isopropyl monocarbonate, t-pentylperoxy isopropyl monocarbonate, t-hexylperoxy isopropyl monocarbonate, t-heptylperoxy isopropyl monocarbonate, t-octylperoxy isopropyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy isopropyl monocarbonate, t-butylperoxy n-butyl monocarbonate, t-pentylperoxy n-butyl monocarbonate, t-hexylperoxy n-butyl monocarbonate, t-heptylperoxy n-butyl monocarbonate, t-octylperoxy n-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy n-butyl monocarbonate, t-butylperoxy isobutyl monocarbonate, t-pentylperoxy isobutyl monocarbonate, t -Hexylperoxy isobutyl monocarbonate, t-heptylperoxy isobutyl monocarbonate, t-octylperoxy isobutyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy isobutyl monocarbonate, t-butylperoxy sec-butyl monocarbonate, t-pentylperoxy sec-butyl monocarbonate, t-hexylperoxy sec-butyl monocarbonate, t-heptylperoxy sec-butyl monocarbonate, t-octylperoxy sec-butyl monocarbonate t-butylperoxy t-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy sec-butyl monocarbonate, t-butylperoxy t-butyl monocarbonate, t-pentylperoxy t-butyl monocarbonate, t-hexylperoxy t-butyl monocarbonate, t-heptylperoxy t-butyl monocarbonate, t-octylperoxy t-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy t-butyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-pentylperoxy 2-ethylhexyl monocarbonate ethylhexyl monocarbonate, t-hexylperoxy 2-ethylhexyl monocarbonate, t-heptylperoxy 2-ethylhexyl monocarbonate, t-octylperoxy 2-ethylhexyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexyl monocarbonate, diisobutyl peroxide, cumyl peroxy neodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis(4-t-butylcyclohexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, disuccinic acid peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy) Examples of organic peroxides include hexane, t-hexylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoyl peroxide, t-butylperoxy-2-ethylhexyl carbonate, t-butylperoxyisopropyl carbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxy-3,5,5-trimethylhexanoate, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, and 2,2-di-t-butylperoxybutane. One organic peroxide may be used alone, or two or more organic peroxides may be used in combination.

[0037] Among these, t-butylperoxyisopropyl monocarbonate, t-pentylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexyl monocarbonate, t-pentylperoxy2-ethylhexyl monocarbonate, t-hexylperoxy2-ethylhexyl monocarbonate, t-amylperoxyisopropyl monocarbonate, di-t-hexyl peroxide, t-butylperoxy2-ethylhexyl monocarbonate, Peroxymethylbutylperoxyisobutyrate, t-hexylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, and 1,1,3,3-tetramethylbutylperoxyneodecanoate are preferred organic peroxides because they can efficiently promote crosslinking of PHA.

[0038] The peroxide is preferably a compound having a one-hour half-life temperature of 200° C. or less, more preferably 170° C. or less, and even more preferably 140° C. or less, so that the heating temperature during the crosslinking treatment can be set low. The lower limit may be 50° C. or more, 60° C. or more, or 70° C. or more.

[0039] Particularly preferred organic peroxides exhibiting such a one-hour half-life temperature include t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy 2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, and 1,1,3,3-tetramethylbutylperoxyneodecanoate.

[0040] When the peroxide is an inorganic peroxide, examples of the inorganic peroxide include hydrogen peroxide, potassium peroxide, calcium peroxide, sodium peroxide, magnesium peroxide, potassium persulfate, sodium persulfate, and ammonium persulfate, taking into consideration the heating temperature and time during the crosslinking treatment. Among these, hydrogen peroxide, potassium persulfate, sodium persulfate, and ammonium persulfate are preferred because they are easy to handle and have decomposition temperatures suitable for the heating temperature during the crosslinking treatment. One type of inorganic peroxide may be used alone, or two or more types may be used in combination. Furthermore, an organic peroxide and an inorganic peroxide may be used in combination.

[0041] <Polyfunctional Compound> The crosslinked structure in the crosslinked resin particles (A) may be introduced using only a peroxide, or may be introduced using both a peroxide and a polyfunctional compound, which makes it possible to increase the gel fraction of the crosslinked resin particles (A) with a smaller amount of peroxide.

[0042] The polyfunctional compound refers to a compound having two or more functional groups capable of crosslinking PHA in one molecule. Although not particularly limited, a compound having reactivity with radicals generated from peroxide is preferred, and a compound having two or more radical reactive groups in one molecule is particularly preferred. The radical reactive group is preferably at least one selected from the group consisting of a vinyl group, an allyl group, an acryloyl group, or a methacryloyl group.

[0043] Such polyfunctional compounds are not particularly limited, but examples thereof include allyl (meth)acrylate, allyl alkyl (meth)acrylates, allyloxyalkyl (meth)acrylates, polyfunctional (meth)acrylates having two or more (meth)acrylic groups such as ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol (meth)acrylate, divinylbenzene, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene. Preferred are allyl methacrylate, triallyl isocyanurate, butanediol di(meth)acrylate, and divinylbenzene, and particularly preferred are allyl methacrylate and triallyl isocyanurate.

[0044] When a crosslinked structure is formed in the presence of a polyfunctional compound, the resulting crosslinked resin particles (A) may generally contain a structure derived from the polyfunctional compound, in which case molecular chains of the PHA are bonded to each other via the structure derived from the polyfunctional compound.

[0045] The crosslinked resin particles (A) may be composed solely of a PHA having a crosslinked structure, or may further contain components other than the PHA having a crosslinked structure, such as resins other than PHA, antioxidants, hydrolysis inhibitors, antiblocking agents, crystal nucleating agents, and ultraviolet absorbers.

[0046] The proportion of PHA or P3HA in the crosslinked resin particles (A) is not particularly limited, but may be 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, even more preferably 90% by weight or more, and particularly preferably 95% by weight or more. It may also be 99% by weight or more. There is no particular upper limit, as long as it is 100% by weight or less.

[0047] Examples of the resin other than PHA include aliphatic polyesters other than PHA and aliphatic aromatic polyesters. Examples of aliphatic polyesters other than PHA include (i) polycaprolactone (PCL), (ii) polylactic acid (PLA), and (iii) aliphatic polyesters having a structure obtained by polycondensation of an aliphatic diol and an aliphatic dicarboxylic acid. Specific examples of the aliphatic polyesters having a structure obtained by polycondensation of an aliphatic diol and an aliphatic dicarboxylic acid include polyethylene succinate, polybutylene succinate (hereinafter also referred to as "PBS"), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (hereinafter also referred to as "PBSA"), polyethylene sebacate, polybutylene sebacate, etc. Examples of the aliphatic aromatic polyester include aliphatic aromatic polyesters obtained by copolymerizing both an aliphatic compound and an aromatic compound as monomers. Examples of the aliphatic aromatic polyester include polybutylene adipate terephthalate (hereinafter sometimes referred to as "PBAT"), polybutylene sebacate terephthalate, polybutylene azelate terephthalate, polybutylene succinate terephthalate (hereinafter sometimes referred to as "PBST"), and polybutylene succinate adipate terephthalate. These resins other than PHA may be used alone or in combination of two or more. In the crosslinked resin particles (A), the resin other than PHA may be crosslinked or not.

[0048] The crosslinked resin particles (A) are different from the expanded resin particles disclosed in WO 2007 / 049694 and WO 2019 / 146555, and are preferably non-expanded, i.e., do not contain substantially any air bubbles inside the particles.

[0049] When not expanded, the crosslinked resin particles (A) have a relatively high apparent density of 0.6 g / cm ３ It is preferable that the density exceeds 0.7 g / cm３ More preferably, it is 0.9 g / cm or more. ３ The apparent density of the crosslinked resin particles (A) can be determined by the method described in JIS K0061 (Method for measuring density and specific gravity of chemical products) or JIS Z8807 (Method for measuring density and specific gravity of solids).

[0050] The average weight per particle of the crosslinked resin particles (A) is not particularly limited, but since the crosslinked resin particles (A) have a small particle size with a volume average particle diameter of 10 μm or less, the value is far less than 0.1 mg.

[0051] <Method for producing crosslinked resin particles (A)> An example of a method for producing crosslinked resin particles (A) will be specifically described. The crosslinked resin particles (A) can be produced by crosslinking PHA in the presence of peroxide in an aqueous dispersion containing PHA-containing resin particles before crosslinking treatment (hereinafter also referred to as uncrosslinked resin particles). In order to efficiently crosslink the PHA, it is preferable to heat the aqueous dispersion of uncrosslinked resin particles containing peroxide to a temperature suitable for decomposing the peroxide.

[0052] More specifically, the method for producing the crosslinked resin particles (A) preferably includes the steps of: (1) preparing an aqueous dispersion of uncrosslinked resin particles in which the uncrosslinked resin particles are dispersed in water; (2) adding a peroxide to the aqueous dispersion of uncrosslinked resin particles to impregnate the uncrosslinked resin particles with the peroxide; and (3) heating the aqueous dispersion of uncrosslinked resin particles impregnated with the peroxide to a heating temperature to crosslink the PHA. It further preferably includes the step of (4) maintaining the heating temperature after all the peroxide has been added.

[0053] In step (1), the aqueous dispersion of uncrosslinked resin particles may be an aqueous dispersion obtained by culturing a PHA-producing microorganism to accumulate PHA particles in the cells, disrupting the cells in the culture solution, and then separating and removing the cell components, or an aqueous dispersion obtained by concentrating or diluting the aqueous dispersion. According to this method, the process from producing PHA particles by culturing a PHA-producing microorganism to crosslinking treatment can be carried out without separating the PHA particles (i.e., uncrosslinked resin particles) from water.

[0054] Alternatively, an aqueous dispersion of uncrosslinked resin particles can be prepared by dispersing dried uncrosslinked resin particles in water. The aqueous dispersion may contain, in addition to water, a water-compatible organic solvent as described below.

[0055] In the aqueous dispersion, the volume average particle diameter of the uncrosslinked resin particles is preferably within the same range as that of the crosslinked resin particles (A) described above. In the case of PHA particles produced by a PHA-producing microorganism, the volume average particle diameter can usually be within the above range, so that an aqueous dispersion of uncrosslinked resin particles having a desired volume average particle diameter can be obtained without carrying out a special step for adjusting the particle diameter.

[0056] The concentration of the uncrosslinked resin particles in the aqueous dispersion is not particularly limited and can be set appropriately, but may be, for example, about 1 to 70% by weight, and preferably about 5 to 50% by weight.

[0057] The aqueous dispersion of uncrosslinked resin particles preferably contains a dispersant to improve the dispersibility of the uncrosslinked resin particles and promote the crosslinking reaction uniformly. Examples of dispersants include anionic surfactants such as dioctyl sodium sulfosuccinate, sodium dodecyl sulfate, sodium lauryl sulfate, and sodium oleate; cationic surfactants such as lauryl trimethylammonium chloride; nonionic surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene polyoxypropylene glycol; and water-soluble polymers such as polyvinyl alcohol, ethylene-modified polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, and sodium polymethacrylate. These dispersants may be used alone or in combination of two or more.

[0058] When a dispersant is used, the amount thereof to be added is not particularly limited, but may be, for example, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the uncrosslinked resin particles.

[0059] In step (2), a peroxide is added to the aqueous dispersion of uncrosslinked resin particles obtained in step (1) to impregnate the uncrosslinked resin particles with the peroxide. The peroxide may be any of those described above. The peroxide may be added in various forms, such as a solid or liquid. Alternatively, a liquid diluted with a diluent may be added. The peroxide may be added all at once, continuously, or in portions.

[0060] When a peroxide and the polyfunctional compound are used in combination, it is preferable to add the polyfunctional compound to the aqueous dispersion of uncrosslinked resin particles in step (2). The polyfunctional compound can be any of those described above. The polyfunctional compound can be added in various forms, such as solid or liquid. Alternatively, a liquid diluted with a diluent or the like can be added. The polyfunctional compound may be added all at once, continuously, or in portions.

[0061] To impregnate the uncrosslinked resin particles with the peroxide and any polyfunctional compound, after or while adding these compounds to an aqueous dispersion of the uncrosslinked resin particles, the temperature of the aqueous dispersion is set to, for example, 0°C or higher but lower than a temperature suitable for decomposing the peroxide employed in the next step (3), and the aqueous dispersion is stirred while maintaining the temperature for, for example, about 1 minute to 5 hours. The temperature of the aqueous dispersion during impregnation may specifically be about 10 to 60°C.

[0062] The amount of peroxide used can be appropriately set in consideration of the gel fraction of the crosslinked resin particles (A). For example, the amount is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, even more preferably 0.3 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the uncrosslinked resin particles.

[0063] According to the production method of crosslinking uncrosslinked resin particles in an aqueous dispersion using a peroxide, crosslinking can be promoted while maintaining the particle size (volume) before crosslinking, and crosslinked resin particles can be easily obtained. On the other hand, it may be difficult to achieve this with the method of crosslinking a resin by melt kneading in the presence of a peroxide. Furthermore, according to the production method of crosslinking uncrosslinked resin particles in an aqueous dispersion using a peroxide, it is easy to control the temperature rise caused by the heat generated during the crosslinking reaction, which is advantageous for efficiently obtaining crosslinked resin particles having a safe and stable crosslinked structure (quality).

[0064] The amount of the polyfunctional compound used may also be appropriately determined in consideration of the gel fraction of the crosslinked resin particles (A). For example, the amount is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 15 parts by weight, even more preferably 0.1 to 10 parts by weight, still more preferably 0.2 to 5 parts by weight, and particularly preferably 0.3 to 3 parts by weight, relative to 100 parts by weight of the uncrosslinked resin particles.

[0065] In step (3), the aqueous dispersion of uncrosslinked resin particles impregnated with peroxide is heated to a temperature suitable for decomposing the peroxide. The heating temperature is preferably within a range of about 25°C above or below the one-hour half-life temperature of the peroxide. Specifically, the heating temperature is preferably 30 to 140°C, more preferably 50 to 135°C, and even more preferably 60 to 130°C. This method makes it possible to crosslink the PHA at a temperature lower than the melting temperature of the PHA, thereby avoiding deterioration of the PHA due to heating during the crosslinking treatment.

[0066] In the subsequent step (4), it is preferable to maintain the heating temperature. This allows the crosslinking reaction using the peroxide to proceed sufficiently. The time for maintaining the heating temperature is not particularly limited, but is preferably 1 minute to 15 hours, and more preferably 1 hour to 10 hours.

[0067] By carrying out the above steps (1) to (4), an aqueous dispersion of the crosslinked resin particles (A) can be obtained. This aqueous dispersion can be used to produce the powder or granule according to this embodiment. Details will be described later.

[0068] <Anti-agglomerating agent (B)> The powder or granule according to this embodiment contains an anti-agglomerating agent (B) in addition to the crosslinked resin particles (A). By containing the anti-agglomerating agent (B), it is possible to form a powder or granule that has good handleability despite containing the crosslinked resin particles (A).

[0069] The anti-agglomerating agent (B) is a component that can reduce or prevent adhesion or aggregation of the crosslinked resin particles (A) when the crosslinked resin particles (A) are dried. The anti-agglomerating agent (B) is present so as to cover at least a portion of the surface of the powder or granules, which are secondary aggregates of the crosslinked resin particles (A), thereby reducing the exposed surface area of ​​the crosslinked resin particles (A) in the powder or granules, thereby suppressing adhesion or aggregation of the crosslinked resin particles (A). More specifically, it can reduce or prevent secondary aggregation of the dried product of the crosslinked resin particles (A) (e.g., powder or granules obtained by drying using a spray drying method) and adhesion to equipment, machines, containers, etc. used during drying and melt-kneading. As a result, a powder or granule with high fluidity and good handleability can be obtained. Another advantage is that it improves productivity and broadens the range of melt-kneading conditions and methods.

[0070] From the viewpoint of further suppressing adhesion or aggregation of the crosslinked resin particles (A), the surface coverage of the crosslinked resin particles (A) with the anti-aggregation agent (B) is preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and particularly preferably 50% or more. There is no particular upper limit, as long as it is 100% or less.

[0071] The surface coverage is a value determined as follows: In an electron microscope photograph of the appearance of the powder or granule, the areas of the regions where the surfaces of the secondary agglomerates of the crosslinked resin particles (A) are coated with the anti-agglomerating agent (B) and the regions where the surfaces of the secondary agglomerates of the crosslinked resin particles (A) are exposed and not coated with the anti-agglomerating agent (B) are calculated, and the surface coverage is calculated from each area based on the following formula: Surface coverage (%) = [area of ​​the regions where the surfaces of the secondary agglomerates of the crosslinked resin particles (A) are coated with the anti-agglomerating agent (B) / (area of ​​the regions where the surfaces of the secondary agglomerates of the crosslinked resin particles (A) are coated with the anti-agglomerating agent (B) + area of ​​the regions where the surfaces of the secondary agglomerates of the crosslinked resin particles (A) are exposed)] x 100.

[0072] The anti-aggregating agent (B) may be either an inorganic component or an organic compound. Either an inorganic component or an organic compound may be used, or both may be used in combination. Furthermore, two or more types of inorganic components may be used in combination, or two or more types of organic compounds may be used in combination.

[0073] As inorganic components usable as the anti-agglomeration agent (B), components known as inorganic fillers for thermoplastic resins can be used. Examples include silica-based inorganic fillers such as quartz, fumed silica, silicic anhydride, fused silica, crystalline silica, amorphous silica, fillers formed by condensing alkoxysilanes, and ultrafine amorphous silica, as well as alumina, zircon, iron oxide, zinc oxide, titanium oxide, silicon nitride, boron nitride, aluminum nitride, silicon carbide, glass, silicone rubber, silicone resin, titanium oxide, carbon fiber, mica, graphite, carbon black, ferrite, graphite, diatomaceous earth, clay, clay, talc, calcium carbonate, manganese carbonate, magnesium carbonate, barium sulfate, and silver powder. These may be surface-treated to improve dispersibility in the resin composition. These may be used alone or in combination of two or more.

[0074] The organic compound usable as the anti-aggregating agent (B) is not particularly limited, but is preferably a water-soluble compound from the viewpoint of ease of handling during spray drying. Specific examples of such organic compounds include, but are not particularly limited to, polyhydric alcohols, fatty acid amides, polysaccharides, oligosaccharides, glycerin fatty acid esters, etc. These may be used alone or in combination of two or more.

[0075] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, erythritol, pentaerythritol, threitol, arabinitol, xylitol, ribitol, iditol, galactitol, glucitol, mannitol, sorbitol, inositol, maltotol, lactitol, etc. Among these, sugar alcohols are preferred, and pentaerythritol is particularly preferred.

[0076] Examples of fatty acid amides include behenamide, erucamide, uric acid amide, coconut acid amide, stearic acid amide, palmitic acid amide, behenamide, brassidic acid amide, acetamide, benzamide, propionic acid amide, oleic acid amide, ricinoleic acid amide, etc. Among these, behenamide and / or erucamide are preferred.

[0077] Examples of polysaccharides include chitin, chitosan, starch, cellulose, agarose, carrageenan, heparin, hyaluronic acid, alginic acid, pectin, xyloglucan, glucomannan, glycogen, dextran, cellulose, and cellulose derivatives such as acetylcellulose and methylcellulose.

[0078] Examples of oligosaccharides include fructooligosaccharides, soybean oligosaccharides, galactooligosaccharides, xylooligosaccharides, isomaltooligosaccharides, lactose-fructose oligosaccharides, and cyclic oligosaccharides such as cyclodextrin and cycloisomaltooligosaccharide.

[0079] Examples of glycerin fatty acid esters include monoglycerides, acetylated monoglycerides, organic acid monoglycerides, and polyglycerin fatty acid esters.

[0080] Among the compounds described above as the anti-aggregation agent (B), there are also compounds that can exhibit effects other than anti-aggregation (for example, a crystal nucleating agent, an inorganic filler, an organic filler, an inorganic filler, an antioxidant, a hydrolysis inhibitor, an ultraviolet absorber, a colorant such as a dye or a pigment, and an antistatic agent).

[0081] <Powder and granules> As described above, the powder and granules according to this embodiment contain crosslinked resin particles (A) and an anti-agglomerating agent (B). In this specification, the term "powder and granules" encompasses both powders and granules. In this specification, the term "powder and granules" refers to an object having a median diameter of 20 μm to 10 mm. The shape of the powder and granules is not particularly limited, and may be, for example, approximately spherical, flat, cubic, spindle-shaped, or needle-shaped. The powder and granules are preferably in powder and / or granular form, but may also be in pellet form as long as the median diameter is within the above-mentioned range.

[0082] In the powder or granule, the content of the crosslinked resin particles (A) relative to the total content of the crosslinked resin particles (A) and the anti-agglomerating agent (B) is preferably 10% by weight or more, more preferably 20% by weight or more, and even more preferably 30% by weight or more, because the crosslinked resin particles (A) can easily achieve effects such as improving the mechanical strength of the thermoplastic resin, such as impact resistance and tear strength. It may also be 40% by weight or more. Furthermore, the upper limit of the content of the crosslinked resin particles (A) is preferably 99.5% by weight or less, more preferably 99% by weight or less, and even more preferably 98% by weight or less, because this can further improve the handleability of the powder or granule. It may also be 95% by weight or less, or 90% by weight or less.

[0083] The powder or granular material according to this embodiment may be substantially composed only of the crosslinked resin particles (A) and the anti-agglomerating agent (B), but may also contain, within the scope of not impairing the effects of the invention, one or more of the following: dispersants or emulsifiers, pH adjusters, inorganic fillers, colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolites, fragrances such as vanillin and dextrin, plasticizers, antioxidants, weather resistance improvers, ultraviolet absorbers, crystal nucleating agents, lubricants, release agents, water repellents, antibacterial agents, sliding property improvers, etc. Furthermore, the powder or granular material according to this embodiment may contain various components resulting from the manufacturing process, within the scope of not impairing the effects of the invention.

[0084] The powder or granule according to this embodiment is mainly composed of crosslinked resin particles (A) and an anti-agglomerating agent (B). Specifically, the total proportion of the crosslinked resin particles (A) and the anti-agglomerating agent (B) in the entire powder or granule may typically be 60 to 100% by weight, 80 to 100% by weight, 90 to 100% by weight, 95 to 100% by weight, or 99 to 100% by weight. The upper limit may be 99.9% by weight or less, or 99% by weight or less.

[0085] From the viewpoint of improving the handleability of the powder and granules according to this embodiment, the median diameter of the powder and granules is 20 μm to 10 mm, preferably 25 μm to 7 mm, more preferably 30 μm to 5 mm, and even more preferably 35 μm to 3 mm. The median diameter of the powder and granules may be 20 μm or more and 1000 μm or less. In this case, the powder and granules can be called "powder." The lower limit of the median diameter may be 30 μm or more. The upper limit may be 500 μm or less, 300 μm or less, 200 μm or less, or 100 μm or less.

[0086] The median diameter of powder or granules may be measured in a dry state, or using a dispersion in which the powder or granules are dispersed in an aqueous solvent. When powder or granules tend to aggregate in an aqueous solvent, it is preferable to add the powder or granules to an aqueous solvent containing a small amount of the above-mentioned dispersant, stir the mixture, and measure the powder or granules in a state in which the powder or granules are not aggregated. A general-purpose measuring device can be used when measuring in a dry state, and an example of such a device is the LMS-3000 manufactured by Seishin Enterprise Co., Ltd. A general-purpose measuring device can be used when measuring powder or granules in a dispersed state in an aqueous solvent, and an example of such a device is the Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. More specifically, the particle diameter at which the larger and smaller sides of the cumulative particle diameter distribution obtained by measurement are equal (50%) is defined as the "median diameter (D50)."

[0087] The powder or granule according to this embodiment preferably has a low moisture content, specifically, a moisture content of 5% by weight or less, more preferably 3% by weight or less, and even more preferably 1% by weight or less.

[0088] <Method for Producing Powder and Granular Material> The method for producing the powder and granular material according to this embodiment is not particularly limited. However, a powder and granular material containing crosslinked resin particles (A) and an anti-agglomerating agent (B) can be obtained by preparing an aqueous dispersion containing crosslinked resin particles (A) and an anti-agglomerating agent (B), separating a mixture of crosslinked resin particles (A) and an anti-agglomerating agent (B) from the aqueous dispersion, and removing water from the separated mixture of crosslinked resin particles (A) and an anti-agglomerating agent (B).

[0089] The method for separating the mixture of crosslinked resin particles (A) and deflocculating agent (B) from the aqueous dispersion is not particularly limited, and examples thereof include filtration, centrifugation, heat drying, freeze drying, and spray drying. For example, spray drying can be used to obtain dried crosslinked resin particles (A) and deflocculating agent (B), i.e., powder or granules, directly from the aqueous dispersion. Alternatively, the mixture of crosslinked resin particles (A) and deflocculating agent (B) separated from the aqueous dispersion can be extruded in an extruder to completely remove residual moisture and obtain a powder or granule containing the crosslinked resin particles (A) and deflocculating agent (B) in pellet form. An aggregation step using a coagulant and / or pH adjustment may also be performed.

[0090] The aqueous dispersion containing the crosslinked resin particles (A) and the anti-aggregating agent (B) can be prepared by adding the anti-aggregating agent (B) to the aqueous dispersion of the crosslinked resin particles (A). The aqueous dispersion of the crosslinked resin particles (A) can be produced as described above.

[0091] When the anti-agglomerating agent (B) is insoluble in water, the volume average particle diameter of the anti-agglomerating agent (B) in the aqueous dispersion is preferably in the range of 0.01 μm to 20 μm. By using an anti-agglomerating agent (B) having such a particle diameter, a powder having a particle diameter within the specific range according to this embodiment can be suitably produced. The lower limit of the particle diameter is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more. The upper limit of the particle diameter is preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less.

[0092] When the anti-aggregation agent (B) is an inorganic component, the inorganic component may be added as a solid to the aqueous dispersion of the crosslinked resin particles (A), or the inorganic component may be made into an aqueous dispersion and then added to the aqueous dispersion of the crosslinked resin particles (A). The volume average particle diameter of the inorganic component after dispersion in water is preferably 0.01 μm to 20 μm, as described above.

[0093] The method for preparing the aqueous dispersion of the inorganic component is not particularly limited, and a commercially available aqueous dispersion may be used, or an aqueous dispersion prepared by adding the inorganic component to water and then finely dispersing the inorganic component by shearing with a homogenizer or the like may be used. When preparing the aqueous dispersion, temperature adjustment, pH adjustment, etc. may be performed.

[0094] A dispersant may be used to prepare a stable aqueous dispersion. Examples of dispersants that can be used include those described above for the "aqueous dispersion of uncrosslinked resin particles." These dispersants may be used alone or in combination of two or more. When a dispersant is used, the amount added is not particularly limited, but may be, for example, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight, per 100 parts by weight of the inorganic component.

[0095] When the anti-aggregating agent (B) is an organic compound, the organic compound may be added as it is to the aqueous dispersion of the crosslinked resin particles (A), or the organic compound may be made into an aqueous dispersion and then added to the aqueous dispersion of the crosslinked resin particles (A).

[0096] The method for preparing the aqueous dispersion of the organic compound is not particularly limited, and a commercially available aqueous dispersion may be used, or an aqueous dispersion prepared by adding an organic compound to water and then carrying out stirring, temperature adjustment, pH adjustment, or the like to disperse the organic compound may be used.

[0097] A dispersant may be used to prepare a stable aqueous dispersion. Examples of dispersants that can be used include those described above for the "aqueous dispersion of uncrosslinked resin particles." These dispersants may be used alone or in combination of two or more. When a dispersant is used, the amount added is not particularly limited, but may be, for example, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight, per 100 parts by weight of the organic compound.

[0098] The aqueous medium contained in the aqueous dispersion containing the crosslinked resin particles (A) and the anti-aggregating agent (B) may be water alone or a mixed solvent of water and a water-compatible organic solvent. In the mixed solvent, the concentration of the water-compatible organic solvent is not particularly limited as long as it is equal to or lower than the solubility in water of the organic solvent used.

[0099] The organic solvent is not particularly limited, but examples thereof include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, pentanol, hexanol, and heptanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; nitriles such as acetonitrile and propionitrile; amides such as dimethylformamide and acetamide; dimethyl sulfoxide, pyridine, and piperidine. Among these, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, acetonitrile, and propionitrile are preferred because they are easily removable. Furthermore, methanol, ethanol, 1-propanol, 2-propanol, butanol, and acetone are more preferred because they are easily available. Furthermore, methanol, ethanol, and acetone are particularly preferred.

[0100] The water content in the entire aqueous medium contained in the aqueous dispersion containing the crosslinked resin particles (A) and the anti-aggregating agent (B) is preferably 5% by weight or more, more preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, and particularly preferably 70% by weight or more. It may be 90% by weight or more, or even 95% by weight or more. There is no particular upper limit, and it may be 100% by weight or less.

[0101] The total concentration of the crosslinked resin particles (A) and the deflocculating agent (B) in the aqueous dispersion containing the crosslinked resin particles (A) and the deflocculating agent (B) is not particularly limited, but is preferably 10% by weight or more, more preferably 15% by weight or more, and even more preferably 20% by weight or more, because this is economically advantageous in terms of drying utility and improves productivity. Furthermore, the upper limit of the total concentration is preferably 65% ​​by weight or less, more preferably 60% by weight or less, in order to ensure the fluidity of the aqueous dispersion. The method for adjusting the total concentration is not particularly limited, and examples thereof include adding an aqueous medium and removing a portion of the aqueous medium (for example, by centrifuging and then removing the supernatant).

[0102] The pH of the aqueous dispersion containing the crosslinked resin particles (A) and the anti-aggregating agent (B) is preferably adjusted to 8 or less, more preferably 7 or less, and more preferably 6 or less, as necessary, to suppress a decrease in the molecular weight of the resin component, for example, during spray drying and during processing steps after drying. Furthermore, the lower limit of the pH is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, from the viewpoint of the acid resistance of the container. The method for adjusting the pH is not particularly limited, and examples thereof include a method of adding an acid. The acid is not particularly limited, and may be either an organic acid or an inorganic acid. More specifically, examples of the acid that can be used include sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid.

[0103] The aqueous dispersion containing the crosslinked resin particles (A) and the deflocculating agent (B) may contain, within the scope of the invention, one or more of the following: dispersants or emulsifiers, pH adjusters, inorganic fillers, colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolite, fragrances such as vanillin and dextrin, plasticizers, antioxidants, weather resistance improvers, ultraviolet absorbers, crystal nucleating agents, lubricants, release agents, water repellents, antibacterial agents, sliding property improvers, etc. Furthermore, the aqueous dispersion containing the crosslinked resin particles (A) and the deflocculating agent (B) may contain, within the scope of the invention, various components resulting from the manufacturing process.

[0104] In an aqueous dispersion containing crosslinked resin particles (A) and an anti-aggregating agent (B), the crosslinked resin particles (A), the anti-aggregating agent (B), and an aqueous medium are the main components. Specifically, the total proportion of the crosslinked resin particles (A) and the anti-aggregating agent (B) relative to the total solid content of the aqueous dispersion may typically be 60 to 100 wt %, 80 to 100 wt %, 90 to 100 wt %, 95 to 100 wt %, or 99 to 100 wt %. The upper limit may be 99 wt % or less, or 95 wt % or less.

[0105] The powdered granules according to this embodiment can be suitably produced by spray-drying the aqueous dispersion containing the crosslinked resin particles (A) and the anti-aggregating agent (B) described above. Examples of spray-drying methods include a method in which the aqueous dispersion is supplied as fine droplets into a dryer and dried while coming into contact with hot air in the dryer. The method for supplying the aqueous dispersion in the form of fine droplets into the dryer (atomizer) is not particularly limited, and examples include known methods such as a method using a rotating disk or a method using a nozzle. The method for contacting the droplets with hot air in the dryer is not particularly limited, and examples include a co-current method, a counter-current method, and a combination of these.

[0106] The drying temperature during spray drying may be any temperature that can remove most of the aqueous medium from the droplets of the aqueous dispersion. The drying temperature can be appropriately set under conditions that allow drying to the desired moisture content and minimize the occurrence of quality deterioration (reduction in molecular weight, color tone, etc.), melting, etc. For example, the temperature of the hot air blown into the spray dryer can be appropriately selected within the range of 40 to 300°C. The volume of hot air blown into the dryer can also be appropriately set depending on, for example, the size of the dryer.

[0107] <Uses of Powder and Granule> The uses of the powder and granule according to this embodiment are not particularly limited, and the powder and granule can be used in any application in which conventionally known crosslinked resin particles are used. Specific examples include, but are not limited to, resin modifiers, rheology adjusters for paints or adhesives, paint pigments, paper coating agents, matting agents, antiblocking agents, cosmetic additives, toner additives, liquid crystal spacers, coating agents, fillers for adhesive tapes, fiber processing agents, test particles for medical diagnosis, and fillers.

[0108] The powder particles according to this embodiment may be processed into articles other than the powder particles. Examples of such articles include, but are not limited to, granules and the molded articles described below. Therefore, one aspect of the present disclosure also encompasses a resin composition containing crosslinked resin particles (A) and an anti-agglomerating agent (B), wherein the crosslinked resin particles (A) contain a polyhydroxyalkanoate resin and have a gel fraction of 50% or more. The details of the crosslinked resin particles (A) and the anti-agglomerating agent (B) and the ratios of the two components may follow the descriptions above.

[0109] The shape of the granules obtained by processing the resin composition according to the present disclosure is not particularly limited, and may be, for example, approximately spherical, flat, cubic, spindle-shaped, needle-shaped, etc. The median diameter of the granules is not particularly limited, and may be, for example, about 1 mm to 10 mm. The granules may be in the form of pellets.

[0110] When the powder-grain material according to this embodiment is processed into granules, it has the advantage of preventing classification when mixing with the thermoplastic resin (C) described below in pellet form, and preventing clinging to the screw in a kneader. Examples of a manufacturing method for processing the powder-grain material according to this embodiment into granules include, but are not limited to, a method in which the powder-grain material is melted and extruded using an extruder and then cut with a blade.

[0111] Furthermore, a molded article can also be produced from the powder or granule according to this embodiment. By incorporating the crosslinked resin particles (A), the molded article is expected to have improved mechanical properties such as impact resistance and tear strength. A molded article may be produced using the powder or granule according to this embodiment alone, or may be produced after mixing with optional additives and / or a thermoplastic resin (C). When mixing with optional additives or a thermoplastic resin (C), it is preferable to produce a molded article after obtaining a thermoplastic resin composition by a melt-kneading step.

[0112] The thermoplastic resin composition can be produced by a known method. Specifically, the powdered or granular material according to this embodiment, the thermoplastic resin (C) and / or any additives can be melt-kneaded using an extruder, kneader, Banbury mixer, kneading roll, or the like. When melt-kneading, it is preferable to mix the components while taking care to avoid a decrease in molecular weight due to thermal decomposition. Alternatively, the thermoplastic resin composition can be produced by dissolving each component in a solvent and then removing the solvent.

[0113] As the optional additives, those mentioned above as additives that may be contained in the powder or granular material according to this embodiment can be used.

[0114] The thermoplastic resin (C) is not particularly limited as long as it can be melted by heating and then cooled and solidified to form a desired shape. Specific examples include polyolefin resins such as polyethylene and polypropylene, acrylic resins such as polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, and polymethyl methacrylic acid, AS resin, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester resin, and cyclic polyolefin. These thermoplastic resins may be used alone or in combination of two or more. The thermoplastic resin (C) preferably has a gel fraction of less than 50%. The thermoplastic resin (C) is preferably a non-crosslinked resin.

[0115] As the thermoplastic resin (C), polyester resins are particularly preferred due to their good compatibility with the crosslinked resin particles (A) containing a polyhydroxyalkanoate resin. Examples of such polyester resins include PHAs such as polyglycolic acid, poly(3-hydroxyalkanoate) resins, and poly(4-hydroxyalkanoate) resins; polylactic acid; aliphatic polyesters such as polyesters formed by the polycondensation of an aliphatic diol and an aliphatic dicarboxylic acid; and aliphatic-aromatic polyesters containing both an aliphatic compound and an aromatic compound as monomers. Examples of aliphatic polyesters other than PHAs include polycaprolactone, polyethylene succinate, polybutylene succinate (PBS), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (PBSA), polyethylene sebacate, and polybutylene sebacate. Examples of aliphatic aromatic polyesters include poly(butylene adipate-co-butylene terephthalate) (PBAT), poly(butylene sebacate-co-butylene terephthalate), poly(butylene azelate-co-butylene terephthalate), poly(butylene succinate-co-butylene terephthalate) (PBST), polyethylene furanoate, etc. These polyester resins may be used alone or in combination of two or more.

[0116] Since the crosslinked resin particles (A) contain a biodegradable PHA, it is preferable that the thermoplastic resin (C) also contains a biodegradable resin, which can enhance the biodegradability of the thermoplastic resin composition as a whole.

[0117] Furthermore, when the crosslinked resin particles (A) are produced from plant-derived raw materials, it is preferable that the thermoplastic resin (C) is also a resin produced from plant-derived raw materials from the viewpoint of resource circulation.

[0118] When the thermoplastic resin (C) contains a biodegradable resin, the content thereof is preferably 10 to 100% by weight, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, and particularly preferably 90% by weight or more, of the entire thermoplastic resin (C).

[0119] The biodegradable resin used as the thermoplastic resin (C) preferably contains the aliphatic polyester described above, and particularly preferably contains PHA and / or polylactic acid, because it has good compatibility with the crosslinked resin particles (A) and provides an excellent effect of improving impact resistance and / or tear strength due to the powder particles according to this embodiment. Note that the PHA used as the thermoplastic resin (C) preferably does not have a crosslinked structure.

[0120] When the thermoplastic resin (C) contains PHA and / or polylactic acid, the content thereof is preferably 10 to 100% by weight, more preferably 30% by weight or more, even more preferably 50% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more, of the entire thermoplastic resin (C).

[0121] When the thermoplastic resin (C) contains both PHA and polylactic acid, the weight ratio of PHA:polylactic acid is not particularly limited, but is preferably 10:90 to 90:10, and more preferably 20:80 to 80:20.

[0122] The PHA that can be used as the thermoplastic resin (C) is not particularly limited, and examples thereof include polyglycolic acid, P3HA, and poly(4-hydroxyalkanoate)-based resins. Only one type of PHA may be used, or two or more types may be used in combination. Among these, P3HA is particularly preferred.

[0123] The P3HA that can be used as the thermoplastic resin (C) is the same as the P3HA related to the crosslinked resin particles (A), and the various P3HAs described above can be used. The P3HA used as the thermoplastic resin (C) is preferably different from the P3HA used for the crosslinked resin particles (A), and is more preferably a resin that is harder than the P3HA used for the crosslinked resin particles (A).

[0124] When the P3HA used as the thermoplastic resin (C) contains 3-hydroxybutanoic acid (3HB) repeating units, from the viewpoint of the balance between flexibility and strength, the composition ratio of 3HB repeating units is preferably 80 to 99 mol%, more preferably 82 to 97 mol%, of all monomer repeating units (100 mol%). When the composition ratio of 3HB repeating units is 80 mol% or more, the rigidity of the P3HA can be further improved. On the other hand, when the composition ratio of 3HB repeating units is 99 mol% or less, the flexibility of the P3HA tends to be further improved. As P3HA, two or more types having different composition ratios of 3HB repeating units may be used in combination.

[0125] The molecular weight of the PHA used as the thermoplastic resin (C) is not particularly limited, but the weight-average molecular weight is preferably 50,000 to 3,000,000, more preferably 100,000 to 2,000,000, and more preferably 150,000 to 1,500,000. By setting the weight-average molecular weight to 50,000 or more, the thermoplastic resin composition according to this embodiment can achieve good rigidity and strength. On the other hand, by setting the weight-average molecular weight to 3,000,000 or less, the production and handling of the PHA can be facilitated.

[0126] The polylactic acid usable as the thermoplastic resin (C) may be any conventionally known polylactic acid, and may be either crystalline or amorphous. The polylactic acid may be a homopolymer of lactic acid or a copolymer of lactic acid and another monomer. Alternatively, it may be a blend of these. Examples of the other monomer include aliphatic hydroxycarboxylic acids other than lactic acid, aliphatic polyhydric alcohols, aliphatic polycarboxylic acids, and polyfunctional polysaccharides.

[0127] The lactic acid raw material for producing polylactic acid is not particularly limited, and examples thereof include L-lactic acid, D-lactic acid, DL-lactic acid, or a mixture thereof, and L-lactide, D-lactide, meso-lactide, or a mixture thereof. Lactic acid obtained by microbial fermentation from renewable plant-derived raw materials such as starch is preferably used. The method for producing polylactic acid is not particularly limited, and known methods such as dehydration condensation polymerization and ring-opening polymerization can be used.

[0128] The molecular weight of the polylactic acid used as the thermoplastic resin (C) is not particularly limited, but the weight-average molecular weight is preferably 50,000 to 1,000,000, more preferably 70,000 to 700,000, and more preferably 100,000 to 400,000. By setting the weight-average molecular weight to 50,000 or more, the thermoplastic resin composition according to this embodiment can achieve good rigidity and strength. On the other hand, by setting the weight-average molecular weight to 1,000,000 or less, the production and handling of the polylactic acid can be facilitated.

[0129] The content of the thermoplastic resin (C) in the thermoplastic resin composition can be determined appropriately from the viewpoint of improving mechanical properties such as impact resistance and tear strength, but is preferably 40 to 99 wt% of the total of the powder particles according to this embodiment and the thermoplastic resin (C). Within this range, the impact resistance and / or tear strength of the thermoplastic resin (C) can be improved. The content of the thermoplastic resin (C) may be 45 to 95 wt%, 47 to 93 wt%, 50 to 90 wt%, 55 to 85 wt%, 55 to 80 wt%, 55 to 75 wt%, or 55 to 70 wt% of the total. The content of the thermoplastic resin (C) may be 60 wt% or more, 70 wt% or more, 80 wt% or more, 85 wt% or more, 88 wt% or more, or 90 wt% or more of the total.

[0130] The content of the crosslinked resin particles (A) in the thermoplastic resin composition can be determined appropriately from the viewpoint of improving mechanical properties such as impact resistance and tear strength. However, it is preferably 1 to 60 wt% of the total of the powder particles according to this embodiment and the thermoplastic resin (C). Within this range, the impact resistance and / or tear strength of the thermoplastic resin (C) can be improved. The content of the crosslinked resin particles (A) may be 5 wt% or more, 7 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, or 30 wt% or more of the total. The content of the crosslinked resin particles (A) is preferably 55 wt% or less, more preferably 53 wt% or less, and even more preferably 50 wt% or less of the total. It may also be 45 wt% or less, 40 wt% or less, 30 wt% or less, 20 wt% or less, 15 wt% or less, 12 wt% or less, or 10 wt% or less.

[0131] The content of the anti-agglomerating agent (B) in the thermoplastic resin composition can be determined appropriately from the viewpoint of suppressing adhesion or aggregation of the crosslinked resin particles (A) and improving mechanical properties such as impact resistance and tear strength, but is preferably 0.01 to 20 wt % of the total of the powder particles according to this embodiment and the thermoplastic resin (C). Within this range, the impact resistance and / or tear strength of the thermoplastic resin (C) can be improved while reducing or suppressing adhesion or aggregation of the crosslinked resin particles (A). The content of the anti-agglomerating agent (B) may be 0.05 to 15 wt %, 0.1 to 12 wt %, 0.2 to 10 wt %, or 0.5 to 8 wt % of the total.

[0132] <Crystal Nucleating Agent> The thermoplastic resin composition may further contain a crystal nucleating agent. When the thermoplastic resin (C) is a crystalline resin, the inclusion of a crystal nucleating agent in the thermoplastic resin composition promotes crystallization during molding, thereby improving molding processability, productivity, etc. When the thermoplastic resin composition contains a crystal nucleating agent, there is also the advantage that a thermoplastic resin composition and a molded article thereof having excellent heat resistance or mechanical properties can be obtained.

[0133] The crystal nucleating agent is not particularly limited, and conventionally known ones can be used. Examples of the crystal nucleating agent include inorganic substances such as talc, kaolinite, montmorillonite, mica, synthetic mica, clay, zeolite, silica, carbon black, graphite, boron nitride, zinc oxide, titanium oxide, tin oxide, calcium carbonate, magnesium carbonate, aluminum oxide, neodymium oxide, barium sulfate, sodium chloride, and metal phosphates; sugar alcohol compounds derived from natural products such as erythritol, pentaerythritol, galactitol, mannitol, and arabitol; polysaccharides such as chitin and chitosan; polyols such as aliphatic alcohols (polyols), polyvinyl alcohol, and polyethylene oxide; sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, and terephthalic acid salts. metal salts of organic carboxylic acids such as potassium phosphate, calcium oxalate, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octacosanoate, calcium octacosanoate, sodium stearate, potassium stearate, lithium stearate, calcium stearate, magnesium stearate, barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, zinc salicylate, aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, and sodium cyclohexanecarboxylate; organic sulfonates such as sodium p-toluenesulfonate and sodium sulfoisophthalate;Carboxylic acid amides such as ethylene stearic acid amide, ethylene bislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, and trimesic acid tris(t-butylamide), lauric acid esters, palmitic acid esters, oleic acid esters, stearic acid esters, erucic acid esters, N-oleyl palmitic acid ester, N-oleyl oleic acid ester, N-oleyl stearate, N-stearyl oleic acid ester, N-stearyl stearate, N-stearyl erucic acid ester, methylene bisstearate, ethylene bislauric acid ester, ethylene biscapric acid ester, ethylene bisoleic acid ester, ethylene bisstearate, ethylene biserucic acid ester, ethylene Examples of suitable crystal nucleating agents include carboxylic acid esters such as butylene bisisostearate, butylene bisstearate, and p-xylylene bisstearate; dicarboxylic acid derivatives such as dimethyl adipate, dibutyl adipate, diisodecyl adipate, and dibutyl sebacate; cyclic compounds having a functional group C═O and one or more functional groups selected from the group consisting of NH, S, and O in the molecule, such as indigo, quinacridone, and quinacridone magenta; sorbitol derivatives such as bisbenzylidene sorbitol and bis(p-methylbenzylidene)sorbitol; compounds containing a nitrogen-containing heteroaromatic nucleus, such as pyridine, triazine, and imidazole; phosphate ester compounds, bisamides of higher fatty acids, and metal salts of higher fatty acids; branched polylactic acid; and low-molecular-weight poly(3-hydroxybutyrate). These crystal nucleating agents may be used alone or in combination of two or more.

[0134] The content of the nucleating agent is not particularly limited as long as it can promote the crystallization of the thermoplastic resin (C). The content of the nucleating agent is preferably 0.05 to 12 parts by weight, more preferably 0.10 to 10 parts by weight, and even more preferably 0.50 to 8 parts by weight, per 100 parts by weight of the thermoplastic resin (C). When the content of the nucleating agent is within the above range, the effect of the nucleating agent can be obtained while suppressing a decrease in viscosity during molding and in the physical properties of the molded product.

[0135] <Lubricant> The thermoplastic resin composition may further contain a lubricant. When the thermoplastic resin composition contains a lubricant, the surface smoothness of the obtained molded article can be improved.

[0136] The lubricant is not particularly limited. Examples of the lubricant include, but are not limited to, fatty acid metal salts such as magnesium stearate and calcium stearate; fatty acid amides such as behenic acid amide, stearic acid amide, erucic acid amide, oleic acid amide, methylene bis-stearic acid amide, and ethylene bis-stearic acid amide; polyethylene wax, oxidized polyester wax, glycerin mono-fatty acid esters such as glycerin monostearate, glycerin monobehenate, and glycerin monolaurate; organic acid monoglycerides such as succinic acid saturated fatty acid monoglycerides; sorbitan fatty acid esters such as sorbitan behenate, sorbitan stearate, and sorbitan laurate; polyglycerin fatty acid esters such as diglycerin stearate, diglycerin laurate, tetraglycerin stearate, tetraglycerin laurate, decaglycerin stearate, and decaglycerin laurate; and higher alcohol fatty acid esters such as stearyl stearate. Lubricants may be used alone or in combination of two or more.

[0137] The content of the lubricant (when multiple lubricants are used, the total content) is not particularly limited as long as it can impart lubricity to the molded article. The content of the lubricant is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, even more preferably 0.10 to 10 parts by weight, even more preferably 0.20 to 5 parts by weight, and particularly preferably 0.30 to 4 parts by weight, per 100 parts by weight of the thermoplastic resin (C). When the content of the lubricant is within the above range, it is possible to obtain the effect of the lubricant while avoiding bleeding out of the lubricant onto the surface of the molded article.

[0138] <Other Components> The thermoplastic resin composition may contain other components such as a plasticizer; an organic filler; an inorganic filler; an antioxidant; a hydrolysis inhibitor; an ultraviolet absorber; a colorant such as a dye or a pigment; or an antistatic agent, to the extent that the functionality of the resulting molded article is not impaired.

[0139] The plasticizer is not particularly limited. Examples of the plasticizer include polyester-based plasticizers such as polypropylene glycol sebacate ester; aliphatic dibasic acid ester-based plasticizers such as di-1-butyl adipate, di-n-butyl sebacate, and di-2-ethylhexyl azelate; glycerin-based plasticizers such as glycerin diacetomonolaurate, glycerin diacetomonocaprylate, and glycerin diacetomonodecanoate; polycarboxylic acid ester-based plasticizers such as tri-2-ethylhexyl acetylcitrate and tributyl acetylcitrate; polyolefin plasticizers such as polyethylene glycol, polypropylene glycol, poly(ethylene oxide-propylene oxide) block and / or random copolymers, and polytetramethylene glycol. alkylene glycol-based plasticizers; phosphate ester-based plasticizers such as diphenyl-2-ethylhexyl phosphate and diphenyloctyl phosphate; epoxy-based plasticizers such as epoxidized soybean oil and epoxidized linseed oil fatty acid butyl esters; and castor oil-based plasticizers such as castor oil fatty acid esters, methyl ricinoleate, ethyl ricinoleate, isopropyl ricinoleate, butyl ricinoleate, ethylene glycol monoricylate, propylene glycol monoricylate, trimethylolpropane monoricylate, sorbitan monoricylate, castor oil fatty acid polyethylene glycol esters, castor oil ethylene oxide adducts, castor oil-based polyols, castor oil-based toluene, and castor oil-based diols. These plasticizers may be used alone or in combination of two or more.

[0140] The organic filler is not particularly limited. Examples of the organic filler include fillers made of naturally-derived materials such as wood-based materials (e.g., wood chips, wood flour, sawdust, etc.), rice husks, rice flour, starch, corn starch, rice straw, wheat straw, and natural rubber; organic fibers such as natural plant fibers, natural animal fibers, and synthetic fibers; and fillers made of synthetic resin materials such as polyester, polyacrylic, polyamide, nylon, polyethylene, polyolefin, polyvinyl alcohol, polyvinyl chloride, polyurethane, polyacetal, aramid, PBO (poly-p-phenylene benzobisoxazole), polyphenylene sulfide, acetyl cellulose, polybenzazole, polyarylate, polyvinyl acetate, and synthetic rubber.

[0141] The natural plant fibers are not particularly limited. Examples of the natural plant fibers include kenaf fiber, abaca fiber, bamboo fiber, jute fiber, hemp fiber, linen fiber, henequen (sisal), ramie fiber, hemp, cotton, banana fiber, coconut fiber, palm, paper mulberry, Mitsumata, bagasse, etc. Other examples include regenerated fibers such as pulp, cellulose fiber, and rayon processed from plant fibers. Examples of natural animal fibers include wool, silk, cashmere, and mohair.

[0142] The inorganic filler is not particularly limited. Examples of the inorganic filler include silica-based inorganic fillers (e.g., quartz, fumed silica, silicic anhydride, fused silica, crystalline silica, amorphous silica, fillers formed by condensing alkoxysilanes, ultrafine amorphous silica, etc.), alumina, zircon, iron oxide, zinc oxide, titanium oxide, silicon nitride, boron nitride, aluminum nitride, silicon carbide, glass, silicone rubber, silicone resin, titanium oxide, carbon fiber, mica, graphite, carbon black, ferrite, graphite, diatomaceous earth, clay, clay, talc, calcium carbonate, manganese carbonate, magnesium carbonate, barium sulfate, and silver powder. These inorganic fillers may be surface-treated to improve dispersibility in the resin composition. These inorganic fillers may be used alone or in combination of two or more.

[0143] The antioxidant is not particularly limited. Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. These antioxidants may be used alone or in combination of two or more.

[0144] The hydrolysis inhibitor is not particularly limited. Examples of the hydrolysis inhibitor include carbodiimide compounds, epoxy compounds, isocyanate compounds, and oxazoline compounds. These hydrolysis inhibitors may be used alone or in combination of two or more.

[0145] The ultraviolet absorber is not particularly limited. Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, triazine compounds, salicylic acid compounds, cyanoacrylate compounds, and nickel complex salt compounds. These ultraviolet absorbers may be used alone or in combination of two or more.

[0146] The colorants such as pigments and dyes are not particularly limited. Examples of colorants include inorganic colorants such as titanium oxide, calcium carbonate, chromium oxide, cuprous oxide, calcium silicate, iron oxide, carbon black, graphite, titanium yellow, and cobalt blue; soluble azo pigments such as lake red, lithol red, and brilliant carmine; insoluble azo pigments such as dinitrile orange and fast yellow; phthalocyanine pigments such as monochlorophthalocyanine blue, polychlorophthalocyanine blue, and polybromophthalocyanine green; condensed polycyclic pigments such as indigo blue, perylene red, isoindolinone yellow, and quinacridone red; and dyes such as oracet yellow. These colorants may be used alone or in combination of two or more.

[0147] The antistatic agent is not particularly limited. Examples of the antistatic agent include low molecular weight antistatic agents such as fatty acid ester compounds, aliphatic ethanolamine compounds, and aliphatic ethanolamide compounds, and polymeric antistatic agents. These antistatic agents may be used alone or in combination of two or more.

[0148] The thermoplastic resin composition may further contain a catalyst deactivator (hindered phenol compounds, thioether compounds, vitamin compounds, triazole compounds, polyamine compounds, hydrazine derivative compounds, phosphorus compounds, etc.), a mold release agent (montanic acid and its salts, esters thereof, half esters thereof, stearyl alcohol, stearamide, polyethylene wax, etc.), a color inhibitor (phosphites, hypophosphites, etc.), a silane coupling agent (epoxy silane coupling agent, amino silane coupling agent, (meth)acrylic silane coupling agent, isocyanate silane coupling agent, etc.), a flame retardant (red phosphorus, phosphate ester, brominated polystyrene, brominated polyphenylene ether, The resin composition may also contain inorganic fillers such as fluorinated polycarbonate, aluminum hydroxide, magnesium hydroxide, melamine and cyanuric acid or salts thereof, silicon compounds, etc.), conductive agents (carbon black, etc.), sliding property improvers (graphite, fluororesin, etc.), epoxy compounds (glycidyl ether compounds, glycidyl ester compounds, polymer compounds grafted or copolymerized with a glycidyl compound, etc.), acid anhydride compounds (maleic anhydride, succinic anhydride, polymer compounds grafted or copolymerized with an acid anhydride, etc.), carbodiimide compounds (N,N'-di-2,6-diisopropylphenylcarbodiimide, 2,6,2',6'-tetraisopropyldiphenylcarbodiimide, polycarbodiimide, etc.), etc.

[0149] The content of each of the other components described above is not particularly limited as long as the effect of one embodiment of the present invention is exhibited, and can be appropriately determined by a person skilled in the art.

[0150] The thermoplastic resin composition can be produced by a known method. Specifically, the powder and granule according to this embodiment, the thermoplastic resin (C), and optional components such as a crystal nucleating agent, a lubricant, and other components can be melt-kneaded using an extruder, a kneader, a Banbury mixer, a kneading roll, or the like. When melt-kneading, it is preferable to mix the components while taking care to avoid a decrease in molecular weight due to thermal decomposition. The thermoplastic resin composition can also be produced by dissolving all raw materials (components) in a soluble solvent and then removing the solvent.

[0151] When the thermoplastic resin composition is produced by melt kneading, each component may be charged separately into an extruder, etc., or each component may be mixed in advance and then charged into an extruder, etc. For example, an aqueous dispersion of the thermoplastic resin (C) and an aqueous dispersion of the powdery or granular material according to the present embodiment may be mixed, and then the resulting mixture may be dried in a dryer to obtain a mixed powder, which may then be charged into an extruder, etc.

[0152] When melt-kneaded using an extruder, the obtained thermoplastic resin composition may be extruded into a strand shape and then cut to be processed into particle shapes such as a bar shape, a cylindrical shape, an elliptical cylindrical shape, a sphere shape, a cube shape, a rectangular parallelepiped shape, or the like.

[0153] The resin temperature during melt kneading cannot be generally defined because it depends on the melting point and melt viscosity of the resin used, but from the viewpoint of uniformly dispersing the powder or granular material according to this embodiment in the thermoplastic resin (C) while avoiding thermal decomposition of the resin component, it is preferably 120 to 250°C, more preferably 130 to 230°C, and even more preferably 140 to 220°C.

[0154] In one embodiment of the present invention, there is provided a molded article obtained by molding the thermoplastic resin composition. The method for molding the thermoplastic resin composition is not particularly limited, and any commonly used molding method can be applied, but specific examples include inflation molding, extrusion molding, calendar molding, T-die extrusion molding, casting, rolling, pressing, injection blow molding, vacuum molding, and injection molding.

[0155] By carrying out the above-described molding method using the thermoplastic resin composition, a molded article having excellent impact resistance and / or tear strength, specifically a sheet molded article, a film molded article, a blow molded article, an extrusion molded article, a vacuum molded article, or an injection molded article, can be produced with good productivity.

[0156] A film or sheet molded product according to one embodiment of the present invention is a film or sheet molded product obtained by molding the thermoplastic resin composition. By incorporating the above-described structure, these film or sheet molded products have the advantage of having improved impact resistance and / or tear strength. By incorporating the above-described structure, a film or sheet molded product according to a preferred embodiment of the present invention has the advantage of having excellent tensile elongation at break and tear strength.

[0157] In this specification, the term "film molded product" refers to a product conforming to JIS 20108:2012, specifically a thin film having a thickness of less than 0.25 mm. In this specification, the term "sheet molded product" refers to a product conforming to JIS 20108:2012, specifically a thin plate having a thickness of 0.25 mm or more.

[0158] Molded articles formed from the thermoplastic resin composition according to this embodiment can be suitably used in agriculture, fisheries, forestry, horticulture, medicine, hygiene products, the food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

[0159] The following items are preferred embodiments of the present disclosure, but the present invention is not limited to them. [Item 1] A powder or granular material having a median diameter of 20 μm to 10 mm, the powder or granular material comprising crosslinked resin particles (A) and an anti-agglomerating agent (B), the crosslinked resin particles (A) comprising a polyhydroxyalkanoate-based resin, having a gel fraction of 50% or more, and a volume-average particle diameter of 0.1 μm to 10 μm. [Item 2] The powder or granular material according to Item 1, wherein the content of the crosslinked resin particles (A) is 10 to 99.5 wt % of the total of the crosslinked resin particles (A) and the anti-agglomerating agent (B). [Item 3] The powder or granular material according to Item 1 or 2, wherein the polyhydroxyalkanoate-based resin is a poly(3-hydroxyalkanoate)-based resin. [Item 4] The powder or granular material according to any one of Items 1 to 3, wherein the crosslinked resin particles (A) are crosslinked using a peroxide. [Item 5] The powder or granule according to Item 4, wherein the crosslinked resin particles (A) are further crosslinked in the presence of a polyfunctional compound. [Item 6] The powder or granule according to any one of Items 1 to 5, wherein the proportion of the polyhydroxyalkanoate resin in the crosslinked resin particles (A) is 80% by weight or more. [Item 7] The powder or granule according to any one of Items 1 to 6, wherein the surface coverage of the crosslinked resin particles (A) with the deflocculating agent (B) is 10 to 100%. [Item 8] The powder or granule according to any one of Items 1 to 7, wherein the deflocculating agent (B) is an inorganic component. [Item 9] The powder or granule according to any one of Items 1 to 8, wherein the deflocculating agent (B) is a polyhydric alcohol. [Item 10] The powder or granule according to any one of Items 1 to 9, wherein the deflocculating agent (B) is a polysaccharide. [Item 11] The powder or granule according to any one of Items 1 to 10, wherein the deflocculating agent (B) is an oligosaccharide. [Item 12] A method for producing the powder or granule according to any one of items 1 to 11, comprising the steps of preparing an aqueous dispersion containing crosslinked resin particles (A) and an anti-agglomerating agent (B), and spray-drying the aqueous dispersion. [Item 13] A thermoplastic resin composition comprising the powder or granule according to any one of items 1 to 11 and a thermoplastic resin (C). [Item 14] The thermoplastic resin composition according to item 13, wherein the thermoplastic resin (C) comprises a biodegradable resin.[Item 15] A molded article obtained by molding the thermoplastic resin composition according to item 13 or 14.

[0160] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0161] [1] Measurement conditions 1-1. Weight average molecular weight The resin to be measured was dissolved in chloroform and heated in a hot water bath at 60°C for 30 minutes. The soluble matter was filtered through a disposable PTFE filter with a 0.45 μm pore size. The filtrate was then subjected to GPC measurement under the following conditions to determine the weight average molecular weight. GPC measurement device: High performance liquid chromatograph 20A system manufactured by Shimadzu Corporation Column: K-G 4A (1 column), K-806M (2 columns) manufactured by Showa Denko K.K. Sample concentration: 1 mg / ml Free liquid: chloroform solution Free liquid flow rate: 1.0 ml / min Sample injection amount: 100 μL Analysis time: 30 minutes Standard sample: standard polystyrene

[0162] 1-2. Volume average particle diameter The volume average particle diameter of the crosslinked resin particles, uncrosslinked resin particles, or anti-agglomerating agent was measured in the form of particle latex. The measuring device used was a Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd.

[0163] 1-3. Gel Fraction Dried crosslinked resin particles were added to chloroform to a concentration of 0.7% by weight, and dissolved at 60°C for 30 minutes to obtain a chloroform solution. After leaving the solution at room temperature for 3 hours, the chloroform solution was filtered through a membrane filter with a pore size of 0.45 μm. Losses were prevented by pouring chloroform over the inside of the container and the filter multiple times to thoroughly wash the solution before filtering. The gel remaining on the filter was dried, and the weight of the filter was measured, and the gel fraction was calculated using the following formula: Gel Fraction (%) = [(Weight of filter including dried gel - Weight of filter only) / Weight of crosslinked resin particles used in measurement] x 100

[0164] [2] Raw materials for crosslinked resin particles 2-1. Uncrosslinked resin particles Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate): (3-hydroxybutyrate) / (3-hydroxyhexanoate)=72 / 28 (mol / mol), weight average molecular weight Mw: 500,000 to 1,500,000, volume average particle size: 1.7 μm 2-2. Peroxide Di-sec-butyl peroxydicarbonate ("Luperox 225" manufactured by Arkema Yoshitomi Co., Ltd., 1-hour half-life temperature: 69°C) 2-3. Polyfunctional compound Triallyl isocyanurate

[0165] [3] Method for Preparing an Aqueous Dispersion of Crosslinked Resin Particles (A) An aqueous dispersion (100 parts by weight of solids) of uncrosslinked resin particles dispersed in water, 200 parts by weight of deionized water, 2 parts by weight of peroxide, 2 parts by weight of sodium dioctyl sulfosuccinate, and 0.5 parts by weight of a polyfunctional compound were added to a glass vessel equipped with a stirrer, baffles, a nitrogen inlet / outlet, and a thermometer. Stirring was initiated at room temperature, and the atmosphere in the glass vessel was simultaneously purged with nitrogen. The contents of the glass vessel were then stirred at room temperature for 1 hour to allow the peroxide and polyfunctional compound to impregnate the uncrosslinked resin particles, and the temperature was then raised to the reaction temperature of 75°C. After reaching the reaction temperature, the mixture was allowed to react at this temperature for 3.5 hours. After the reaction was completed, the pH was adjusted to a stable pH of 3.8 at 50-55°C, yielding an aqueous dispersion of crosslinked resin particles (A). The volume average particle diameter of the crosslinked resin particles (A) in the aqueous dispersion was measured using the method described above and found to be 1.7 μm. After adjusting the pH of the aqueous dispersion, the dispersion was dried in an oven to obtain solidified crosslinked resin particles (A). The gel fraction of the particles was measured by the above-mentioned method and found to be 95%.

[0166] [4] Method for preparing aqueous dispersions for spray drying (a) Aqueous dispersion of the above-described crosslinked resin particles (A) (solid content concentration: 25%) (b-1) Nanosilica aqueous dispersion (Snowtex MP2040, manufactured by Nissan Chemical Industries, Ltd.) Particle shape: spherical, volume average particle size (MV): 150 nm, solid content concentration: 37.8% (b-2) Nanosilica aqueous dispersion (Snowtex ZL, manufactured by Nissan Chemical Industries, Ltd.) Particle shape: spherical, volume average particle size (MV): 81 nm, solid content concentration: 40.3% (b-3) Nanosilica aqueous dispersion (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) Particle shape: spherical, solid content concentration: 30.3% (b-4) Nanosilica aqueous dispersion A predetermined amount of fumed silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was added to pure water and the mixture was dispersed using an ultrasonic homogenizer. (b-5) Nanosilica Water Dispersion: A predetermined amount of fumed silica (AEROSIL OX50 manufactured by Nippon Aerosil Co., Ltd.) was added to pure water and dispersed using an ultrasonic homogenizer. Volume average particle size (MV): 300 nm, solid content: 10%. (b-6) Talc Water Dispersion: A predetermined amount of talc (MicroAce K-1 manufactured by Nippon Talc Co., Ltd.) was added to pure water and stirred at room temperature. Average particle size by volume (MV): 10 μm, solid content: 20% (b-7) Pentaerythritol (Neuralyzer P, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) (b-8) α-cyclodextrin (reagent, manufactured by Tokyo Chemical Industry Co., Ltd.) (b-9) Starch aqueous solution A predetermined amount of water-soluble starch (reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to pure water and stirred at room temperature. Solid content: 10%

[0167] Aqueous dispersion (a) and (b-1) to (b-9) were mixed in the proportions (based on the solid content weight) shown in Table 1, and the pH was adjusted to a stable pH of 3.8 to obtain a mixed aqueous dispersion. Note that, since (b-7) and (b-8) are soluble in water, the solids were added directly to aqueous dispersion (a).

[0168] [5] Spray Drying Method The mixed aqueous dispersion obtained as described above was spray dried using an L-8 type spray dryer manufactured by Okawara Kakoki Co., Ltd. under the conditions shown in Table 1 to obtain a powder containing crosslinked resin particles (A) and an anti-aggregating agent (B).

[0169] (Median diameter) The median diameter of the powder particles obtained by spray drying was measured in a dry state by a laser diffraction / scattering method using an LMS-3000 manufactured by Seishin Enterprise Co., Ltd. The results are shown in Table 1.

[0170] (Evaluation of powder and granule state) The state of the powder and granules obtained by spray drying was evaluated based on the following criteria. The results are shown in Table 1. A: Free flowing powder and granules with no adhesion and cohesion B: Powder and granules with increased adhesion and cohesion but with good flowability C: Powder and granules with further increased adhesion and cohesion and decreased flowability, but still in a powder and granule state D: Unable to be made into a powder and granule

[0171]

[0172] In Examples 1 to 17 in Table 1, a powder containing crosslinked resin particles (A) and an anti-agglomerating agent (B) was obtained by spray-drying a mixed aqueous dispersion containing crosslinked resin particles (A) and an anti-agglomerating agent (B). The powders obtained in each Example had flowability and were easy to handle. Among these, the powders obtained in Examples 1 to 10 and 12 to 17 were excellent in terms of flowability, and the powders obtained in Examples 1 to 3, 6, 7, 12, and 15 to 17, which used silica, pentaerythritol, α-cyclodextrin, or starch as the anti-agglomerating agent (B), were particularly excellent.

[0173] On the other hand, in Comparative Example 1, spray drying of an aqueous dispersion containing only crosslinked resin particles (A) was attempted, but the resin particles adhered to the inner wall of the spray dryer while agglomerating, making recovery difficult, and it was impossible to obtain a powder or granule like those obtained in each Example. This shows that the crosslinked resin particles (A) have extremely high adhesion and agglomeration properties and are difficult to recover as a powder or granule alone.

[0174] [6] Micrograph and surface coverage of powder and granules The powder and granules obtained in Example 1 were fixed to a sample stage, and gold was vapor-deposited. Then, the powder and granules were observed using a scanning electron microscope (EF-SEM: S-4800, manufactured by Hitachi High-Technologies Corporation) to obtain a micrograph. The photograph is shown in Figure 1. From Figure 1, it can be seen that the surfaces of the secondary aggregates of the crosslinked resin particles (A) are covered with fine particles of silica, which is the anti-agglomeration agent (B).

[0175] Next, in the photograph, the areas of the regions where the surfaces of the secondary aggregates of crosslinked resin particles (A) were coated with the anti-agglomerating agent (B) and the regions where the surfaces of the secondary aggregates of crosslinked resin particles (A) were exposed were calculated, and the surface coverage was calculated from each area using the following formula: Surface coverage (%) = [area of ​​regions where the surfaces of the secondary aggregates of crosslinked resin particles (A) were coated with the anti-agglomerating agent (B) / (area of ​​regions where the surfaces of the secondary aggregates of crosslinked resin particles (A) were coated with the anti-agglomerating agent (B) + area of ​​regions where the surfaces of the secondary aggregates of crosslinked resin particles (A) were exposed)] × 100 As a result, the surface coverage in Example 1 was 100%.

[0176] Similarly, the powders and granules obtained in Examples 2, 4, 9, 11, 12, and 16 were observed under an electron microscope, and the resulting micrographs are shown in Figures 2 to 7. Based on these micrographs, the surface coverage was calculated in the same manner as above. The results were as follows: Figure 2, Example 2: 70% Figure 3, Example 4: 30% Figure 4, Example 9: 30% Figure 5, Example 11: 20% Figure 6, Example 12: 100% Figure 7, Example 16: 100%

[0177] In Figures 2 to 4, silica, which is the deflocculating agent (B), is observed as fine particles adhering to the surfaces of the secondary aggregates of crosslinked resin particles (A), as in Figure 1. In Figures 5 and 6, talc or pentaerythritol, which is the deflocculating agent (B), is observed as a thin plate-like substance. In Figure 7, it can be seen that α-cyclodextrin, which is the deflocculating agent (B), is uniformly coated on the entire surfaces of the secondary aggregates of crosslinked resin particles (A).

[0178] [7] Evaluation of physical properties of thermoplastic resin compositions 7-1. Components of test specimens (a) Thermoplastic resin: Blending amounts (parts by weight) shown in Tables 2 to 5 (C-1): Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (Kaneka Biodegradable Polymer PHBH (registered trademark) manufactured by Kaneka Corporation), (3-hydroxybutyrate) / (3-hydroxyhexanoate) = 94.4 / 5.6 (mol / mol), weight average molecular weight Mw: 530,000 (C-2): PLA, Total Corbion PLA, Luminy (registered trademark) LX975 (C-3): PBSA, Mitsubishi Chemical Corporation, FD92PB

[0179] (b) Powders and granules prepared in Examples 1 to 17 or crosslinked resin particles (A): amounts (parts by weight) shown in Tables 2 to 5. The crosslinked resin particles (A) were prepared by adjusting the pH of the aqueous dispersion of the crosslinked resin particles (A) and then drying it in an oven to solidify it. (c) Pentaerythritol (Neuraizer P, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.): amounts (parts by weight) shown in Tables 2 to 5. (d) Behenamide (BNT22H, manufactured by Nippon Fine Chemical Industry Co., Ltd.): 0.5 parts by weight.

[0180] 7-2. Method for preparing test pieces (Method for preparing test pieces in Reference Examples 1, 4 to 5, and Examples 18 to 23, 25, 33 to 51) The mixture of (a), (b), (c), and (d) was kneaded in a twin-screw kneader (KZW15TWIN-45WG, manufactured by Technovel Co., Ltd.) with a barrel temperature heated to 140 to 165°C at a screw rotation speed of 80 rpm to obtain a kneaded product. This kneaded product was dried in a dryer at 80°C for 4 hours to sufficiently reduce the moisture content, and then a thermoplastic resin composition was obtained. The obtained thermoplastic resin composition was press-molded at 165°C to prepare test pieces of a predetermined thickness.

[0181] (Method of preparing test pieces in Reference Examples 2 to 3, and Examples 24, 26 to 32) The mixture of (a), (b), (c), and (d) was melt-kneaded in a twin-screw extruder (Shibaura Machine Co., Ltd. TEM-26SS) heated to a barrel temperature of 155°C at a screw rotation speed of 100 rpm to obtain a melt-kneaded product (mixture). The obtained melt-kneaded product was dried in a dehumidifying dryer at 50°C for 12 hours to sufficiently reduce the moisture content, thereby obtaining a thermoplastic resin composition. Furthermore, the obtained thermoplastic resin composition was press-molded at 120 to 165°C to prepare test pieces of a predetermined thickness.

[0182] The 500 μm thick sheets prepared by the method described above were aged for 7 days under conditions of 23°C and 50% RH, and then punched into test pieces conforming to JIS K 71603. A tensile impact test was carried out according to JIS K 7160 Method A. The results are shown in Tables 2 to 4.

[0183] 7-4. Measurement of Tensile Properties After aging the 200 μm thick sheets prepared by the above method under conditions of 23°C and 50% RH for 7 days, the tensile properties were measured at a test speed of 100 mm / min using a tensile tester (Shimadzu Corporation: EZ-LX 1kN) according to JIS K 7133. The results are shown in Tables 2 to 4.

[0184] 7-5. Elmendorf Tear Strength A 110 μm thick film prepared by the method described above was aged for 7 days under conditions of 23°C and 50% RH. Thereafter, tear strength was measured in accordance with JIS K7128-2 using a light-load tear tester ("No. 2037 Special Specification Machine" manufactured by Kumagai Riki Kogyo Co., Ltd.) having the same functions and structure as the standard Elmendorf tear tester specified in JIS K7128-2. The measured value (N) was divided by the film thickness (mm) to obtain the Elmendorf tear strength (N / mm). The results are shown in Table 5.

[0185]

[0186]

[0187]

[0188] In Examples 18 to 25 and 33 to 43 in Tables 2 to 4, it can be seen that by blending the powder particles of Examples 1 to 17 containing crosslinked resin particles (A) and an anti-agglomerating agent (B) with a thermoplastic resin (C), the impact strength of the thermoplastic resin (C) was improved compared to Reference Example 1, which did not contain the powder particles. Among them, Examples 18 to 23, 25, 36, 39 to 42 exhibited high levels of impact strength, and in particular, Examples 18, 19, 21 to 23, 25, 36, and 40 to 42 exhibited impact strength equivalent to or higher than Reference Example 4, which did not contain an anti-agglomerating agent (B) and contained only crosslinked resin particles (A). Furthermore, Examples 18 to 23, 25, 33 to 43 exhibited tensile properties comparable to those of Reference Example 4.

[0189] It can also be seen from Examples 26 to 32 in Tables 2 to 4 that by blending the powder particles of Example 6 containing crosslinked resin particles (A) and an anti-agglomerating agent (B) with a thermoplastic resin (C), the impact strength of the thermoplastic resin (C) was improved compared to Reference Examples 2 and 3 in which the powder particles were not blended.

[0190]

[0191] In Examples 44 to 51 in Table 5, it can be seen that by blending the powder particles of each Example containing crosslinked resin particles (A) and an anti-agglomerating agent (B) with a thermoplastic resin (C), the Elmendorf tear strength value was increased compared to Reference Example 1 containing only thermoplastic resin (C) or Reference Example 5 in which only crosslinked resin particles (A) were blended with a thermoplastic resin (C).

Claims

1. A powder or granular material having a median diameter of 20 μm to 10 mm, the powder or granular material containing crosslinked resin particles (A) and an anti-agglomerating agent (B), the crosslinked resin particles (A) containing a polyhydroxyalkanoate resin, the gel fraction being 50% or more, and the volume average particle diameter being 0.1 μm or more and 10 μm or less.

2. The powder or granule according to claim 1, wherein the content of the crosslinked resin particles (A) in the total of the crosslinked resin particles (A) and the anti-agglomerating agent (B) is 10 to 99.5% by weight.

3. The powder or granule according to claim 1 or 2, wherein the polyhydroxyalkanoate resin is a poly(3-hydroxyalkanoate) resin.

4. The powder or granule according to claim 1 or 2, wherein the crosslinked resin particles (A) are crosslinked using a peroxide.

5. The powder or granule according to claim 4, wherein the crosslinked resin particles (A) are further crosslinked in the presence of a polyfunctional compound.

6. The powder or granule according to claim 1 or 2, wherein the proportion of said polyhydroxyalkanoate resin in said crosslinked resin particles (A) is 80% by weight or more.

7. The powder or granule according to claim 1 or 2, wherein the surface coverage of the crosslinked resin particles (A) with the anti-agglomerating agent (B) is 10 to 100%.

8. The powder or granule according to claim 1 or 2, wherein the anti-agglomerating agent (B) is an inorganic component.

9. The powder or granule according to claim 1 or 2, wherein the anti-agglomerating agent (B) is a polyhydric alcohol.

10. The powder or granule according to claim 1 or 2, wherein the anti-agglomerating agent (B) is a polysaccharide.

11. The powder or granule according to claim 1 or 2, wherein the anti-agglomerating agent (B) is an oligosaccharide.

12. A method for producing the powder or granular material according to claim 1 or 2, comprising the steps of: preparing an aqueous dispersion containing crosslinked resin particles (A) and an anti-agglomerating agent (B); and spray-drying the aqueous dispersion.

13. A thermoplastic resin composition comprising the powder or granule according to claim 1 or 2 and a thermoplastic resin (C).

14. The thermoplastic resin composition according to claim 13, wherein the thermoplastic resin (C) comprises a biodegradable resin.

15. A molded article obtained by molding the thermoplastic resin composition according to claim 13.