Resin particles

Abstract

To provide a resin particle that has, while having a biodegradability, an excellent in-water hydrolysis resistance.SOLUTION: Provided is a resin particle that contains (A) cellulose acylate, (B) an aromatic compound not having a functional group that reacts with the (A) cellulose acylate, and having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to aromatic group, and (C) an ester compound having a long-chain hydrocarbon group, and in which the mass ratio of the (A) cellulose acylate and the (B) aromatic compound, ((B) / (A)), is 0.15 or more and 0.8 or less, and the mass ratio of the (A) cellulose acylate and the (C) ester compound, ((C) / (A)), is 0.02 or more and 0.10 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to resin particles. [Background technology]

[0002] Patent Document 1 proposes a resin composition comprising "a cellulose acylate (A) having at its side chain a group having a hydrocarbon chain having 5 or more carbon atoms, a polyester resin (B), and an ester compound (C) having a molecular weight of 250 or more and 2000 or less, wherein the mass ratio ((B) / (A)) of the polyester resin (B) to the cellulose acylate (A) is 0.05 or more and 0.5 or less, and the mass ratio ((C) / (A)) of the ester compound (C) to the cellulose acylate (A) is 0.02 or more and 0.15 or less."

[0003] Patent Document 2 proposes "a cellulose-based resin obtained by bonding a cardanol analogue or a derivative thereof, which contains cardanol and cardulle and has a cardulle content of 3.0 mass% or more, to the cellulose or a derivative thereof, utilizing the cellulose hydroxyl groups of the cellulose or a derivative thereof and the phenolic hydroxyl groups of the cardanol analogue." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-151794 A [Patent Document 2] JP 2015-081326 A Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide a resin particle comprising cellulose acylate (A), an aromatic compound (B) which does not have a functional group reactive with the cellulose acylate (A) and which has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to the aromatic group, and an ester compound (C) having a long-chain hydrocarbon group, the resin particle having excellent resistance to hydrolysis in water while having biodegradability, compared with a case in which the mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is less than 0.15 or exceeds 0.8, the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is less than 0.02 or exceeds 0.10, the mass loss rate after 90 days in water at 50°C and pH 7.8 exceeds 30%, or the hydrophobicity degree is less than 30. [Means for solving the problem]

[0006] The above problems are solved by the following means: <1> Cellulose acylate (A), an aromatic compound (B) which does not have a functional group reactive with the cellulose acylate (A) and which has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; and (C) an ester compound having a long chain hydrocarbon group, a mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more and 0.8 or less; The resin particles have a mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) of 0.02 or more and 0.10 or less. <2> The cellulose acylate (A) is a cellulose acylate having two or more kinds of acyl groups. <1> The resin particles according to claim 1. <3> The aromatic compound (B) is a cardanol compound (B1). <1> or <2> The resin particles according to claim 1. <4> The cardanol compound (B1) is at least one compound selected from the group consisting of a compound represented by the following general formula (CDN1) and a compound represented by the following general formula (CDN1-e): <3> The resin particles according to claim 1. [ka] (In the general formula (CDN1), R 1 R represents an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and which may have a substituent. 2 represents a hydroxy group, a carboxy group, an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and may have a substituent. P2 represents an integer of 0 to 4. When P2 is 2 or more, a plurality of R 2 may be the same group or different groups.) [ka] (In the general formula (CDN1-e), L EP represents a single bond or a divalent linking group. 1 , R 2 and P2 are R in general formula (CDN1), 1 , R 2 and P2.) <5> The ester compound (C) is an ester compound having two or more long-chain hydrocarbon groups. <1> ~ <4> 13. The resin particles according to any one of the above. <6> The two or more long chain hydrocarbon groups contained in the ester compound (C) are hydrocarbon groups having 8 to 20 carbon atoms. <5> The resin particles according to claim 1. <7> At least one of the two or more hydrocarbon groups having 8 to 20 carbon atoms contained in the ester compound (C) is a stearyl group. <6> The resin particles according to claim 1. <8> The mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is 0.20 or more and 0.40 or less. <1> ~ <7> 13. The resin particles according to any one of the above. <9> the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is 0.03 or more and 0.07 or less; <1> ~ <8> 13. The resin particles according to any one of the above. <10> Cellulose acylate (A), an aromatic compound (B) having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; and (C) an ester compound having a long chain hydrocarbon group, Resin particles that have a mass loss of 30% or less after 90 days in water at 50°C and pH 7.8. <11> Cellulose acylate (A), an aromatic compound (B) having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; and (C) an ester compound having a long chain hydrocarbon group, Resin particles having a hydrophobicity of 30 or more as measured by the following method. (Method of measuring hydrophobicity) Put 50g of distilled water into a 300ml beaker and stir with a stirrer. Put 0.2g of resin particles into the beaker and disperse them in the distilled water. Drop methanol into the beaker with a dropper. The amount of methanol dropped when all the resin particles have settled is called Me(g), and the hydrophobicity is calculated using the following formula. Hydrophobicity=Me / (Me+50) <12> The volume average particle size is 3 μm or more and 100 μm or less. <1> ~ <11> 13. The resin particles according to any one of the above. <13> The large diameter particle size distribution index GSDv is 1.50 or less. <1> ~ <12> 13. The resin particles according to any one of the above. Effect of the Invention

[0007] <1> According to the invention, in resin particles containing cellulose acylate (A), an aromatic compound (B) which does not have a functional group reactive with the cellulose acylate (A) and which has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to the aromatic group, and an ester compound (C) having a long-chain hydrocarbon group, the resin particles are provided which are biodegradable and have excellent resistance to hydrolysis in water, compared to when the mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is less than 0.15 or exceeds 0.8, or the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is less than 0.02 or exceeds 0.10.

[0008] <2> According to the present invention, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with a case in which the cellulose acylate (A) is a cellulose acylate having one kind of acyl group.

[0009] <3> or <4> According to the invention relating to the above, resin particles are provided which, as compared with a case in which the aromatic compound (B) is bisphenol A, are biodegradable and have excellent resistance to hydrolysis in water.

[0010] <5> , <6> or <7> According to the invention related to the above, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with the case where the ester compound (C) is cetyl 2-ethylhexanoate.

[0011] <8> According to the present invention, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with the case where the mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is less than 0.20 or exceeds 0.40.

[0012] <9> According to the present invention, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with a case in which the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is less than 0.03 or exceeds 0.07.

[0013] <10> According to the present invention, there is provided resin particles comprising cellulose acylate (A), an aromatic compound (B) having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to the aromatic group, and an ester compound (C) having a long-chain hydrocarbon group, which resin particles have excellent resistance to hydrolysis in water while being biodegradable, as compared with resin particles in which the mass loss rate after 90 days in water at 50°C and pH 7.8 exceeds 30%.

[0014] <11> According to the present invention, there is provided resin particles comprising cellulose acylate (A), an aromatic compound (B) having, in addition to a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to the aromatic group, and an ester compound (C) having a long-chain hydrocarbon group, which resin particles have excellent resistance to hydrolysis in water while being biodegradable, compared to resin particles having a hydrophobicity degree of less than 30.

[0015] <12> According to the present invention, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with particles having a volume average particle size of less than 3 μm or more than 100 μm.

[0016] <13> According to the present invention, there are provided resin particles which are biodegradable and have excellent resistance to hydrolysis in water, as compared with particles having a large diameter particle size distribution index GSDv of more than 1.50. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described as an example. The description and examples are merely illustrative of the embodiment, and are not intended to limit the scope of the present invention. In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples.

[0018] In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. Each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition, if the composition contains multiple substances corresponding to each component, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0019] In this specification, the cellulose acylate (A), the aromatic compound (B), and the ester compound (C) are also referred to as component (A), component (B), and component (C), respectively.

[0020] <Resin particles> First embodiment The resin particles according to the first embodiment contain a cellulose acylate (A), an aromatic compound (B) which does not have a functional group that reacts with the cellulose acylate (A) and which has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group, and an ester compound (C) which has a long-chain hydrocarbon group. The mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more and 0.8 or less, and the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is 0.02 or more and 0.10 or less.

[0021] The resin particles according to the first embodiment have the above-mentioned constitution, and are biodegradable and have excellent resistance to hydrolysis in water. The reason for this is presumed to be as follows.

[0022] Cellulose is known as a resin that is rapidly biodegradable, but due to its poor moldability, it has been difficult to produce resin particles containing cellulose. In order to impart moldability to cellulose, it is common to use cellulose acylate (A) in which some of the hydroxyl groups of cellulose are replaced with acyl groups, and to add a plasticizer. However, the cellulose acylate (A) has a problem that its biodegradability is slower than that of cellulose.

[0023] The resin particles according to the first embodiment contain a cellulose acylate (A) (i.e., component (A)) and an aromatic compound (B) (i.e., component (B)) that does not have a functional group that reacts with the cellulose acylate (A) and has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group. This enhances the biodegradability of the resin particles according to the first embodiment. The long-chain aliphatic group of component (B) has a low affinity with component (A), and therefore has a repulsive force between component (A). On the other hand, the phenolic hydroxyl group and the monoglycidyl ether group directly bonded to the aromatic group have a high affinity with component (A). In this way, since component (B) has a site with low affinity and a site with low affinity between component (A) and component (A), it is considered that component (A) and component (B) are mixed in a nearly uniform state. Therefore, in the resin particles according to the first embodiment, the thermal decomposition of component (A) is easily caused by the phenolic hydroxyl group or glycidyl ether group of component (B), and biodegradability is enhanced. This effect is exhibited when the mass ratio ((B) / (A)) of component (A) to component (B) is in the range of 0.15 to 0.8.

[0024] However, resin particles containing components (A) and (B) may undergo hydrolysis in water at temperatures of 40° C. or higher, which may accelerate biodegradability, and therefore the resin particles containing components (A) and (B) may have poor durability in water.

[0025] The resin particles according to the first embodiment contain a component (A), a component (B), and an ester compound (C) having a long-chain hydrocarbon group (i.e., component (C)). This allows the resin particles according to the first embodiment to have excellent resistance to hydrolysis in water while ensuring biodegradability. The ester group of component (C) interacts with the acyl group of component (A) to enhance the affinity with (A). On the other hand, the long-chain hydrocarbon group of component (C) has low affinity with component (A) and is easily oriented on the surface of the resin particles. In other words, the resin particles according to the first embodiment have a hydrophobic particle surface. Therefore, water is less likely to penetrate into the resin particles, and resistance to hydrolysis in water is improved. In addition, the ester group of component (C) also has an affinity with the phenolic hydroxyl group or monoglycidyl ether group of component (B) and suppresses the thermal decomposition of component (A) caused by the phenolic hydroxyl group or the monoglycidyl ether group, which is also a factor in improving resistance to hydrolysis in water. This effect is enhanced when the mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is 0.02 or more and 0.10 or less.

[0026] Therefore, the resin particles according to the first embodiment have excellent resistance to hydrolysis in water while being biodegradable.

[0027] Second Embodiment The resin particles according to the second embodiment contain a component (A), a component (B), and a component (C). In addition, the mass loss rate after 90 days in water at 50°C and pH 7.8 is 30% or less.

[0028] The resin particles according to the second embodiment have the above-mentioned constitution, and are biodegradable and have excellent resistance to hydrolysis in water. The reason for this is presumed to be as follows.

[0029] As described above, the resin particles contain the component (A) and the component (B), and thus become biodegradable resin particles. Furthermore, the resin particles further contain component (C), which improves resistance to hydrolysis in water. Furthermore, the resin particles according to the second embodiment have a mass loss rate of 30% or less after 90 days in water at 50°C and pH 7.8. This indicates that the resin particles have high resistance to hydrolysis in water. For example, by setting the mass ratio of component (A) to component (B) ((B) / (A)) to 0.15 or more and 0.8 or less, and the mass ratio of component (A) to component (C) ((C) / (A)) to 0.02 or more and 0.10 or less, resin particles are likely to have a mass loss rate of 30% or less after 90 days in water at 50°C and pH 7.8.

[0030] Therefore, the resin particles according to the second embodiment have excellent resistance to hydrolysis in water while being biodegradable.

[0031] Third embodiment The resin particles according to the third embodiment contain a component (A), a component (B), and a component (C). In addition, the hydrophobicity measured by the following method is 30 or more. (Method of measuring hydrophobicity) Put 50g of distilled water into a 300ml beaker and stir with a stirrer. Put 0.2g of resin particles into the beaker and disperse them in the distilled water. Drop methanol into the beaker with a dropper. The amount of methanol dropped when all the resin particles have settled is called Me(g), and the hydrophobicity is calculated using the following formula. Hydrophobicity=Me / (Me+50)

[0032] The resin particles according to the third embodiment have the above-mentioned constitution, and are biodegradable and have excellent resistance to hydrolysis in water. The reason for this is presumed to be as follows.

[0033] As described above, the resin particles contain the component (A) and the component (B), and thus become biodegradable resin particles. In addition, the resin particles further contain component (C), and the hydrophobicity of the resin particle surface is increased by the above-mentioned mechanism. Furthermore, the resin particles according to the third embodiment have a hydrophobicity of 30 or more as measured by the above-mentioned method. This indicates that the surface of the resin particles has high hydrophobicity. Therefore, water is less likely to penetrate into the resin particles, and resistance to hydrolysis in water is improved. For example, by making the mass ratio of component (A) to component (B) ((B) / (A)) 0.15 or more and 0.8 or less, and the mass ratio of component (A) to component (C) ((C) / (A)) 0.02 or more and 0.10 or less, resin particles are likely to have a hydrophobicity of 30 or more as measured by the above-mentioned method.

[0034] Therefore, the resin particles according to the third embodiment have excellent resistance to hydrolysis in water while being biodegradable.

[0035] Hereinafter, the resin particles corresponding to any of the resin particles according to the first, second, and third embodiments (hereinafter also referred to as "resin particles according to this embodiment") will be described in detail. However, an example of the resin particles of the present invention may be any of the resin particles according to the first, second, and third embodiments.

[0036] The resin particles according to this embodiment will be described in detail below.

[0037] (Cellulose acylate (A): Component (A)) Cellulose acylate (A) is a cellulose derivative in which at least a part of the hydroxyl groups in cellulose is replaced by an acyl group (acylation). An acyl group is a -CO-R AC (R AC represents a hydrogen atom or a hydrocarbon group.

[0038] The cellulose acylate (A) is, for example, a cellulose derivative represented by the following general formula (CA).

[0039] [ka]

[0040] In the general formula (CA), A 1 , A 2 and A 3 Each independently represents a hydrogen atom or an acyl group, and n represents an integer of 2 or more. 1 , n A 2 and n A's 3 At least some of the n A's in the molecule represent acyl groups. 1 may be all the same, some may be the same, or different from each other. 2 and n A 3 may be entirely the same, partially the same, or different from each other.

[0041] A 1 , A 2 and A 3 The acyl group represented by the formula (I) may have a hydrocarbon group that is linear, branched, or cyclic, but is preferably linear or branched, and more preferably linear.

[0042] A 1 , A 2 and A 3 The acyl group represented by the formula (I) may have a hydrocarbon group which is either a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is more preferably a saturated hydrocarbon group.

[0043] A 1 , A 2 and A 3 The acyl group represented by is preferably an acyl group having 1 to 6 carbon atoms. That is, the cellulose acylate (A) is preferably an acyl group having 1 to 6 carbon atoms. The cellulose acylate (A) having an acyl group having 1 to 6 carbon atoms is more likely to give resin particles having excellent impact resistance than the cellulose acylate (A) having an acyl group having 7 or more carbon atoms.

[0044] A 1 , A 2 and A 3The acyl group represented by may be a group in which a hydrogen atom in the acyl group is substituted with a halogen atom (for example, a fluorine atom, a bromine atom, an iodine atom), an oxygen atom, a nitrogen atom or the like, but is preferably unsubstituted.

[0045] A 1 , A 2 and A 3 Examples of the acyl group represented by include a formyl group, an acetyl group, a propionyl group, a butyryl group (butanoyl group), a propenoyl group, a hexanoyl group, etc. Among these, from the viewpoint of improving the biodegradability and hydrolysis resistance in water of the resin particles, an acyl group having 2 to 4 carbon atoms is more preferable.

[0046] A 1 , A 2 and A 3 The acyl group represented by preferably contains two or more kinds of acyl groups from the viewpoint of improving the biodegradability and resistance to hydrolysis in water of the resin particles.

[0047] Examples of the cellulose acylate (A) include cellulose acetate (cellulose monoacetate, cellulose diacetate (DAC), cellulose triacetate), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB).

[0048] As the cellulose acylate (A), from the viewpoint of improving the biodegradability and hydrolysis resistance in water of the resin particles, cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) are preferred, and cellulose acetate propionate (CAP) is more preferred.

[0049] The cellulose acylate (A) may be used alone or in combination of two or more kinds.

[0050] The weight average polymerization degree of the cellulose acylate (A) is preferably from 200 to 1,000, more preferably from 500 to 1,000, and even more preferably from 600 to 1,000, from the viewpoint of excellent moldability, impact resistance, or toughness of the resin particles.

[0051] The weight-average degree of polymerization of the cellulose acylate (A) is determined from the weight-average molecular weight (Mw) by the following procedure. First, the weight average molecular weight (Mw) of the cellulose acylate (A) is measured in terms of polystyrene using tetrahydrofuran with a gel permeation chromatography apparatus (GPC apparatus: Tosoh Corporation, HLC-8320GPC, column: TSKgel α-M). Then, the degree of polymerization of cellulose acylate (A) is calculated by dividing the molecular weight of the constituent unit of cellulose acylate (A). For example, when the substituent of cellulose acylate is an acetyl group, the molecular weight of the constituent unit is 263 when the degree of substitution is 2.4, and 284 when the degree of substitution is 2.9.

[0052] From the viewpoint of improving the biodegradability and hydrolysis resistance in water of the resin particles, the substitution degree of the cellulose acylate (A) is preferably from 1.5 to 2.9, more preferably from 1.6 to 2.8, even more preferably from 1.7 to 2.7, and particularly preferably from 1.8 to 2.7.

[0053] In cellulose acetate propionate (CAP), the ratio of the substitution degree of acetyl groups to propionyl groups (acetyl groups / propionyl groups) is preferably 0.01 to 1, more preferably 0.05 to 0.1, from the viewpoint of improving the biodegradability and hydrolysis resistance in water of the resin particles.

[0054] In cellulose acetate butyrate (CAB), the ratio of the substitution degree of acetyl groups to butyryl groups (acetyl groups / butyryl groups) is preferably 0.05 or more and 3.5 or less, more preferably 0.08 or more and 3.0 or less, from the viewpoint of improving the biodegradability and hydrolysis resistance in water of the resin particles.

[0055] The degree of substitution of cellulose acylate (A) is an index showing the degree to which hydroxyl groups in cellulose are substituted with acyl groups. In other words, the degree of substitution is an index showing the degree of acylation of cellulose acylate (A). Specifically, the degree of substitution means the intramolecular average number of substitutions in which three hydroxyl groups in the D-glucopyranose unit of cellulose acylate are substituted with acyl groups. The degree of substitution is 1 The ratio is calculated from the integral ratio of the peaks of hydrogen derived from cellulose and hydrogen derived from acyl groups using H-NMR (JMN-ECA / JEOL RESONANCE).

[0056] (Aromatic compound (B): component (B)) The aromatic compound (B) is an aromatic compound that does not have a functional group that reacts with the cellulose acylate (A) and has, in addition to a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to the aromatic group. That is, the aromatic compound (B) is a compound which does not have a functional group which reacts with the cellulose acylate (A), has a long-chain aliphatic group, and has at least one of a phenolic hydroxyl group and a monoglycidyl ether group. Here, examples of the long-chain aliphatic group include saturated aliphatic groups (alkyl groups) and unsaturated aliphatic groups (alkenyl groups, alkynyl groups) having carbon atoms of 6 to 30 (preferably 10 to 20). The aliphatic group may be linear, branched, or cyclic, with linear or branched being preferred, and linear being more preferred.

[0057] Examples of the aromatic compound (B) include compounds in which a phenolic hydroxyl group is substituted on a monocyclic ring, a condensed ring (a polycyclic ring having two or more aromatic rings), a polynuclear ring (a polycyclic ring in which aromatic rings are bonded to each other via a carbon-carbon bond), or a heterocyclic ring (a monocyclic heterocyclic ring, a condensed ring containing a heterocyclic ring, a polynuclear ring containing a heterocyclic ring, etc.) together with a long-chain aliphatic group.

[0058] Specific examples of the aromatic compound (B) include cardanol compounds, phenalkamine compounds, phenol resins, phenol novolac type epoxy resins, phenol resol type epoxy resins, phenol modified palm oil, phenol modified soybean oil, and phenol modified linseed oil. Among these, from the viewpoint of improving biodegradability, the cardanol compound (B1) is preferred as the aromatic compound (B).

[0059] The cardanol compound (B1) refers to a component contained in a naturally derived compound made from cashew (for example, a compound represented by the following structural formulas (b-1) to (b-4)) or a derivative of the above component.

[0060] [ka]

[0061] The cardanol compound (B1) may be a mixture of naturally occurring compounds made from cashews (hereinafter also referred to as a "cashew-derived mixture").

[0062] The cardanol compound (B1) may be a derivative from a mixture derived from cashew. Examples of the derivative from a mixture derived from cashew include the following mixtures and simple substances.

[0063] A mixture in which the composition ratio of each component in the cashew-derived mixture has been adjusted A single substance isolated from a mixture of cashew-derived ingredients -Mixtures containing modified components of cashew-derived mixtures - Mixtures containing polymers obtained by polymerizing ingredients in cashew-derived mixtures Mixtures containing modified polymers obtained by modifying and polymerizing components in a cashew-derived mixture A mixture containing a modified product obtained by further modifying the components in the mixture with the adjusted composition ratio. A mixture containing a polymer obtained by further polymerizing the components in the mixture with the adjusted composition ratio. A mixture containing a modified polymer obtained by further modifying and polymerizing the components in the mixture whose composition ratio has been adjusted. A denatured product obtained by further denaturing the isolated monomer A polymer obtained by further polymerizing the isolated monomer. A modified polymer obtained by further modifying and polymerizing the isolated monomer. Here, the monomer also includes polymers such as dimers and trimers.

[0064] From the viewpoint of improving the biodegradation rate of the resin particles, the cardanol compound (B1) is preferably at least one compound selected from the group consisting of compounds represented by general formula (CDN1) and polymers of compounds represented by general formula (CDN1).

[0065] [ka]

[0066] In the general formula (CDN1), R 1 R represents an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and which may have a substituent. 2 represents a hydroxy group, a carboxy group, an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and may have a substituent. P2 represents an integer of 0 to 4. When P2 is 2 or more, a plurality of R 2 may be the same group or different groups.

[0067] In the general formula (CDN1), R 1 The alkyl group which may have a substituent, represented by the formula (I), is preferably an alkyl group having 3 to 30 carbon atoms, more preferably an alkyl group having 5 to 25 carbon atoms, and further preferably an alkyl group having 8 to 20 carbon atoms. Examples of the substituent include a hydroxy group; a substituent containing an ether bond, such as an epoxy group or a methoxy group; and a substituent containing an ester bond, such as an acetyl group or a propionyl group. Examples of the alkyl group which may have a substituent include a pentadecane-1-yl group, a heptan-1-yl group, an octan-1-yl group, a nonan-1-yl group, a decan-1-yl group, an undecane-1-yl group, a dodecane-1-yl group, and a tetradecane-1-yl group.

[0068] In the general formula (CDN1), R 1 The unsaturated aliphatic group having a double bond and optionally having a substituent, represented by the formula (I) is preferably an unsaturated aliphatic group having 3 to 30 carbon atoms, more preferably an unsaturated aliphatic group having 5 to 25 carbon atoms, and even more preferably an unsaturated aliphatic group having 8 to 20 carbon atoms. The unsaturated aliphatic group preferably has 1 or more and 3 or less double bonds. Examples of the substituent include those exemplified as the substituent for the alkyl group. Examples of the unsaturated aliphatic group having a double bond and optionally having a substituent include a pentadec-8-en-1-yl group, a pentadeca-8,11-dien-1-yl group, a pentadeca-8,11,14-trien-1-yl group, a pentadec-7-en-1-yl group, a pentadeca-7,10-dien-1-yl group, and a pentadeca-7,10,14-trien-1-yl group.

[0069] In the general formula (CDN1), R 1 As the alkyl group, a pentadec-8-en-1-yl group, a pentadeca-8,11-dien-1-yl group, a pentadeca-8,11,14-trien-1-yl group, a pentadec-7-en-1-yl group, a pentadeca-7,10-dien-1-yl group, and a pentadeca-7,10,14-trien-1-yl group are preferable.

[0070] In the general formula (CDN1), R 2 The alkyl group which may have a substituent and the unsaturated aliphatic group which has a double bond and may have a substituent represented by R 1Similarly, preferred examples include those exemplified as the alkyl group which may have a substituent and the unsaturated aliphatic group which has a double bond and may have a substituent, represented by the formula (I) below.

[0071] The compound represented by the general formula (CDN1) may be further modified, for example, epoxidized, and from the viewpoint of improving the biodegradation rate of the resin particles, specifically, it is preferable that the compound represented by the general formula (CDN1) has a structure in which the hydroxyl group is replaced by the following group (EP), that is, the compound represented by the following general formula (CDN1-e).

[0072] [ka]

[0073] In the group (EP) and the general formula (CDN1-e), L EP represents a single bond or a divalent linking group. 1 , R 2 and P2 are R in general formula (CDN1), 1 , R 2 and P2.

[0074] In the group (EP) and the general formula (CDN1-e), L EP Examples of the divalent linking group represented by include an alkylene group which may have a substituent (preferably an alkylene group having 1 to 4 carbon atoms, more preferably an alkylene group having 1 carbon atom), a -CH2CH2OCH2CH2- group, and the like. The above-mentioned substituents include R 1 The substituents are the same as those listed in the above.

[0075] L EP As the alkyl group, a methylene group is preferable.

[0076] The polymer of the compound represented by the general formula (CDN1) refers to a polymer of at least two or more compounds represented by the general formula (CDN1) polymerized with or without a linking group.

[0077] An example of a polymer obtained by polymerizing the compound represented by general formula (CDN1) is a compound represented by the following general formula (CDN2).

[0078] [ka]

[0079] In the general formula (CDN2), R 11 , R 12 and R 13 R each independently represents an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and which may have a substituent. 21 , R 22 and R 23 Each independently represents a hydroxy group, a carboxy group, an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and may have a substituent. P21 and P23 each independently represent an integer of 0 or more and 3 or less, and P22 represents an integer of 0 or more and 2 or less. L 1 and L 2 Each independently represents a divalent linking group. n represents an integer of 0 to 10. When P21 is 2 or more, a plurality of R 21 , when P22 is 2 or more, there are multiple R 22 , and when P23 is 2 or more, there are multiple R 23 may be the same or different groups. When n is 2 or more, a plurality of R 12 , R 22 and L 1 may be the same or different groups, and when n is 2 or greater, a plurality of P22s may be the same or different in number.

[0080] In the general formula (CDN2), R11 , R 12 , R 13 , R 21 , R 22 and R 23 The alkyl group which may have a substituent and the unsaturated aliphatic group which has a double bond and may have a substituent represented by R 1 The above-listed examples are also preferred.

[0081] In the general formula (CDN2), L 1 and L 2 Examples of the divalent linking group represented by include an alkylene group which may have a substituent (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms). The above-mentioned substituents include R 1 The substituents are the same as those listed in the above.

[0082] In formula (CDN2), n is preferably 1 or more and 10 or less, and more preferably 1 or more and 5 or less.

[0083] The compound represented by the general formula (CDN2) may be further modified, for example, may be epoxidized, specifically, may be a compound having a structure in which the hydroxy group of the compound represented by the general formula (CDN2) is replaced with a group (EP), that is, may be a compound represented by the following general formula (CDN2-e).

[0084] [ka]

[0085] In the general formula (CDN2-e), R 11 , R 12 , R 13 , R 21 , R 22 , R 23 , P21, P22, P23, L 1 , L 2and n are each R in general formula (CDN2). 11 , R 12 , R 13 , R 21 , R 22 , R 23 , P21, P22, P23, L 1 , L 2 and n. In the general formula (CDN2-e), L EP1 , L EP2 and L EP3 Each of L independently represents a single bond or a divalent linking group. EP2 may be the same group or different groups.

[0086] In the general formula (CDN2-e), L EP1 , L EP2 and L EP3 The divalent linking group represented by is L in the general formula (CDN1-e). EP Similarly, the divalent linking group represented by the formula (I) is preferably the same as the divalent linking group represented by the formula (I).

[0087] The polymer obtained by polymerizing the compound represented by the general formula (CDN1) may be, for example, a polymer obtained by three-dimensionally crosslinking polymerizing at least three or more compounds represented by the general formula (CDN1) with or without a linking group. Examples of the polymer obtained by three-dimensionally crosslinking polymerizing the compound represented by the general formula (CDN1) include compounds represented by the following structural formulas.

[0088] [ka]

[0089] In the above structural formula, R 10 , R 20 and P20 are R in general formula (CDN1), 1 , R 2 and P2. 10 represents a single bond or a divalent linking group. 10 , R 20 and L10 may be the same or different groups. 20 may be the same or different numbers.

[0090] In the above structural formula, L 10 Examples of the divalent linking group represented by include an alkylene group which may have a substituent (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms). The above-mentioned substituents include R 1 The substituents are the same as those listed in the above.

[0091] The compound represented by the above structural formula may be further modified, for example, may be epoxidized.Specifically, the compound represented by the above structural formula may have a structure in which the hydroxyl group is replaced with a group (EP), and for example, the compound represented by the following structural formula, that is, the polymer in which the compound represented by general formula (CDN1-e) is three-dimensionally crosslinked and polymerized, may be mentioned.

[0092] [ka]

[0093] In the above structural formula, R 10 , R 20 and P20 are R in the general formula (CDN1-e), 1 , R 2 and P2. 10 represents a single bond or a divalent linking group. 10 , R 20 and L 10 may be the same or different groups. 20 may be the same or different numbers.

[0094] In the above structural formula, L 10Examples of the divalent linking group represented by include an alkylene group which may have a substituent (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms). The above-mentioned substituents include R 1 The substituents are the same as those listed in the above.

[0095] From the viewpoint of improving the transparency of the resin molded article, the cardanol compound (B1) preferably contains a cardanol compound (B1) having an epoxy group, and is more preferably a cardanol compound (B1) having an epoxy group.

[0096] Commercially available products may be used as the cardanol compound (B1). Examples of commercially available products include NX-2024, Ultra LITE 2023, NX-2026, GX-2503, NC-510, LITE 2020, NX-9001, NX-9004, NX-9007, NX-9008, NX-9201, and NX-9203 manufactured by Cardolite Co., Ltd., and LB-7000, LB-7250, and CD-5L manufactured by Tohoku Kako Co., Ltd. Commercially available products of cardanol compounds having an epoxy group include NC-513, NC-514S, NC-547, LITE513E, and Ultra LTE 513 manufactured by Cardolite Co., Ltd.

[0097] From the viewpoint of improving the biodegradation rate of the resin molded article, the hydroxyl value of the cardanol compound (B1) is preferably 100 mgKOH / g or more, more preferably 120 mgKOH / g or more, and even more preferably 150 mgKOH / g or more. The hydroxyl value of the cardanol compound (B1) is measured according to ISO14900 Method A.

[0098] When a cardanol compound (B1) having an epoxy group is used as the cardanol compound (B1), from the viewpoint of improving the transparency of a resin molded product, the epoxy equivalent is preferably from 300 to 500, more preferably from 350 to 480, and even more preferably from 400 to 470. The epoxy equivalent of the cardanol compound (B1) having an epoxy group is measured in accordance with ISO3001.

[0099] The molecular weight of the cardanol compound (B1) is preferably 250 or more and 1,000 or less, more preferably 280 or more and 800 or less, and even more preferably 300 or more and 500 or less, from the viewpoint of improving the biodegradation rate of the resin molded article.

[0100] The cardanol compound (B1) may be used alone or in combination of two or more kinds.

[0101] (Ester compound (C): component (C)) The ester compound (C) has an ester group and a long-chain hydrocarbon group.

[0102] A long chain hydrocarbon group is a hydrocarbon group having 8 or more carbon atoms.

[0103] The long-chain hydrocarbon group preferably has 12 or more and 20 or less carbon atoms, more preferably 13 or more and 19 or less, and even more preferably 14 or more and 18 or less carbon atoms, from the viewpoint of improving resistance to hydrolysis in water.

[0104] The long-chain hydrocarbon group may be a saturated or unsaturated hydrocarbon group, but is more preferably a saturated hydrocarbon group.

[0105] The long chain hydrocarbon group may be linear, branched or cyclic, but is preferably linear or branched, and more preferably linear.

[0106] The long-chain hydrocarbon group may be a group in which a hydrogen atom in the long-chain hydrocarbon group is substituted with a halogen atom (for example, a fluorine atom, a bromine atom, an iodine atom), an oxygen atom, a nitrogen atom, or the like, but is preferably unsubstituted.

[0107] Specific examples of the long-chain hydrocarbon group include octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl (cetyl), heptadecyl, octadecyl (stearyl), nonadecyl, and eicosyl groups. From the viewpoint of improving resistance to hydrolysis in water, the long-chain hydrocarbon group is preferably a hexadecyl group (cetyl group) or an octadecyl group (stearyl group), and more preferably an octadecyl group (stearyl group).

[0108] From the viewpoint of improving resistance to hydrolysis in water, the ester compound (C) is preferably an ester compound having two or more long-chain hydrocarbon groups.

[0109] When the ester compound (C) is an ester compound having two or more long-chain hydrocarbon groups, the number of carbon atoms in the long-chain hydrocarbon groups is preferably 12 or more and 20 or less, more preferably 13 or more and 19 or less, and even more preferably 14 or more and 18 or less, from the viewpoint of improving resistance to hydrolysis in water.

[0110] When the ester compound (C) is an ester compound having two or more long-chain hydrocarbon groups, it is preferable that at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 17 to 20 carbon atoms and at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 15 to 18 carbon atoms, it is more preferable that at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 18 or 19 carbon atoms and at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 16 to 18 carbon atoms, it is even more preferable that at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 18 carbon atoms and at least one of the two or more long-chain hydrocarbon groups is a long-chain hydrocarbon group having 16 or 18 carbon atoms.

[0111] Specifically, for example, when the ester compound (C) is an ester compound having two or more long-chain hydrocarbon groups, it is preferable that at least one of the two or more long-chain hydrocarbon groups is a heptadecyl group, an octadecyl group (stearyl group), a nonadecyl group, or an eicosyl group, and at least one of the two or more long-chain hydrocarbon groups is a pentadecyl group, a hexadecyl group (cetyl group), a heptadecyl group, or an octadecyl group (stearyl group). It is more preferable that one of the two or more long-chain hydrocarbon groups is an octadecyl group (stearyl group) or a nonadecyl group and at least one of the two or more long-chain hydrocarbon groups is a hexadecyl group (cetyl group), a heptadecyl group or an octadecyl group (stearyl group), and it is even more preferable that at least one of the two or more long-chain hydrocarbon groups is an octadecyl group (stearyl group) and at least one of the two or more long-chain hydrocarbon groups is a hexadecyl group (cetyl group) or an octadecyl group (stearyl group).

[0112] Specific examples of the ester compound having two or more long-chain hydrocarbon groups include pentadecyl stearate, cetyl stearate, heptadecyl stearate, and stearyl stearate. From the viewpoint of improving the hydrolysis resistance of the resin particles in water, the ester compound having two or more long-chain hydrocarbon groups is preferably at least one of cetyl stearate and stearyl stearate.

[0113] The ester compound (C) may be used alone or in combination of two or more kinds.

[0114] (Content or mass ratio of components (A) to (C)) - Mass ratio of component (A) to component (B) ((B) / (A)) - The mass ratio of component (A) to component (B) ((B) / (A)) is 0.15 or more and 0.8 or less.

[0115] If the mass ratio ((B) / (A)) is less than 0.15, the thermal decomposition action of component (A) by component (B) becomes insufficient, and a high biodegradation rate cannot be obtained. Therefore, the mass ratio ((B) / (A)) is set to 0.15 or more. However, if the mass ratio ((B) / (A)) exceeds 0.8, the biodegradation rate becomes too fast, which may reduce the durability of the resin particles when used in water. Therefore, from the viewpoint of suppressing an excessive biodegradation rate, the mass ratio ((B) / (A)) is set to 0.80 or less.

[0116] From the viewpoint of improving the biodegradation rate while maintaining the durability of the resin particles during use, the mass ratio ((B) / (A)) is preferably 0.20 or more and 0.40 or less, and more preferably 0.20 or more and 0.35 or less.

[0117] - Mass ratio of component (A) to component (C) ((C) / (A)) - The mass ratio of component (A) to component (C) ((C) / (A)) is 0.02 or more and 0.10 or less.

[0118] If the mass ratio ((C) / (A)) is less than 0.02, the amount of component (C) oriented on the surface of the resin particles will be small, and resistance to hydrolysis in water will decrease. Therefore, the mass ratio ((C) / (A)) is set to 0.02 or more. However, if the mass ratio ((C) / (A)) exceeds 0.10, the component (C) will be in excess, which will cause the component (C) to aggregate and crystallize. This will make the layer of component (C) that forms on the surface more susceptible to cracking, reducing resistance to hydrolysis in water. For this reason, the mass ratio ((C) / (A)) is set to 0.10 or less.

[0119] From the viewpoint of improving the resistance of the resin particles to hydrolysis in water, the mass ratio ((C) / (A)) is preferably 0.03 or more and 0.07 or less, and more preferably 0.04 or more and 0.05 or less.

[0120] -Content of component (A)- From the viewpoint of improving the biodegradation rate, it is preferable that the component (A) is contained as a main component. Here, the component (A) being the main component means that the mass ratio of the component (A) to the entire resin particles is the highest.

[0121] Specifically, the total amount of component (A) is preferably 50% by mass or more and 90% by mass or less, more preferably 53% by mass or more and 85% by mass or less, and even more preferably 60% by mass or more and 82% by mass or less, based on the total amount of the resin particles.

[0122] (Other Ingredients) The resin particles according to this embodiment may contain other components. Examples of other components include plasticizers, flame retardants, compatibilizers, release agents, light resistance agents, weather resistance agents, colorants, pigments, modifiers, anti-drip agents, antistatic agents, hydrolysis inhibitors, fillers, reinforcing agents (glass fibers, carbon fibers, talc, clay, mica, glass flakes, milled glass, glass beads, crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, etc.), acid acceptors for preventing release of acetic acid (oxides such as magnesium oxide and aluminum oxide; metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide, and hydrotalcite; calcium carbonate; talc; etc.), and reactive trapping agents (for example, epoxy compounds, acid anhydride compounds, carbodiimides, etc.). The content of each of the other components is preferably 0% by mass or more and 5% by mass or less based on the total amount of the resin particles, where "0% by mass" means that no other components are included.

[0123] The resin particles according to the present embodiment may contain other resins other than the component (A) and the component (B). However, when the other resins are contained, the content of the other resins relative to the total amount of the resin particles is preferably 5% by mass or less, and more preferably less than 1% by mass. It is more preferable that the other resins are not contained (i.e., 0% by mass). Examples of other resins include conventionally known thermoplastic resins, specifically, polycarbonate resins; polypropylene resins; polyester resins; polyolefin resins; polyester carbonate resins; polyphenylene ether resins; polyphenylene sulfide resins; polysulfone resins; polyether sulfone resins; polyarylene resins; polyetherimide resins; polyacetal resins; polyvinyl acetal resins; polyketone resins; polyether ketone resins; polyether ether ketone resins; polyaryl ketone resins; polyether nitrile resins; liquid crystal resins; polybenzimidazole resins; polypa Examples of the resin include lavane acid resins, vinyl polymers or copolymers obtained by polymerizing or copolymerizing one or more vinyl monomers selected from the group consisting of aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters, and vinyl cyanide compounds, diene-aromatic alkenyl compound copolymers, vinyl cyanide-diene-aromatic alkenyl compound copolymers, aromatic alkenyl compound-diene-vinyl cyanide-N-phenylmaleimide copolymers, vinyl cyanide-(ethylene-diene-propylene (EPDM))-aromatic alkenyl compound copolymers, vinyl chloride resins, chlorinated vinyl chloride resins, etc. These resins may be used alone or in combination of two or more.

[0124] (mass reduction rate) The resin particles according to this embodiment have a mass loss rate of 30% or less after 90 days in water at 50° C. and pH 7.8. When the mass loss rate is 30% or less, the resin particles have improved resistance to hydrolysis in water.

[0125] The mass reduction rate is preferably 0% or more and 26% or less, more preferably 0% or more and 16% or less, even more preferably 0% or more and 11% or less, and most preferably 0% or more and 5% or less.

[0126] The mass loss rate is measured by the procedure described in the Examples below.

[0127] (Hydrophobicity) The resin particles according to this embodiment have a hydrophobicity of 30 or more as measured by the following method. When the hydrophobicity is 30 or more, the resin particles have improved resistance to hydrolysis in water.

[0128] The hydrophobicity is preferably 30 or more and 95 or less, more preferably 35 or more and 90 or less, and further preferably 40 or more and 85 or less.

[0129] The hydrophobicity is measured as follows. (Method of measuring hydrophobicity) Put 50g of distilled water into a 300ml beaker and stir with a stirrer. Put 0.2g of resin particles into the beaker and disperse them in the distilled water. Drop methanol into the beaker with a dropper. The amount of methanol dropped when all the resin particles have settled is called Me(g), and the hydrophobicity is calculated using the following formula. Hydrophobicity=Me / (Me+50)

[0130] (Shape of resin particles) From the viewpoint of improving the resistance of the resin particles to hydrolysis in water, the resin particles according to this embodiment preferably have a volume average particle size of, for example, 3 μm or more and 100 μm or less. The volume average particle size of the resin particles is more preferably from 5 μm to 50 μm, and further preferably from 8 μm to 30 μm.

[0131] The large particle size distribution index GSDv of the resin particles is, for example, preferably 1.50 or less, more preferably 1.30 or less, and even more preferably 1.20 or less, from the viewpoint of improving the hydrolysis resistance of the resin particles in water.

[0132] The volume average particle size and the large particle size distribution index GSDv of the resin particles are measured as follows. The particle size is measured using an LS particle size distribution analyzer "Beckman Coulter LS13 320 (manufactured by Beckman Coulter)" and the cumulative particle size distribution is plotted from the smallest diameter side on a volume basis. The particle size at 50% of the cumulative distribution is determined as the volume average particle size. On the other hand, the cumulative particle size distribution is plotted from the small diameter side on a volume basis, and the particle size at 50% of the cumulative distribution is defined as the number average particle size D50v, and the particle size at 84% of the cumulative distribution is defined as the number particle size D84v. The large diameter side number particle size distribution index GSDv is calculated by the formula GSDv=(D84v / D50v). 1 / 2 It is calculated as follows.

[0133] The resin particles can be produced, for example, by the following method. 1) A kneading and grinding method in which the components are kneaded together, and the resulting kneaded mixture is ground and classified to obtain resin particles; 2) A dry manufacturing method in which the shape of granules obtained by the kneading and grinding method is changed by mechanical impact force or thermal energy to obtain resin particles. 3) A method in which particle dispersions of each component are mixed, the particles in the dispersion are aggregated, and then heat-fused to obtain resin particles. 4) A dissolution suspension method in which the organic solvent in which each component is dissolved is suspended in an aqueous solvent to granulate resin particles containing each component.

[0134] Among these, from the viewpoint of obtaining resin particles having a volume average particle size and a large particle size distribution index GSDv within the above range, wet methods such as the aggregation-coalescence method and the dissolution-suspension method are preferred.

[0135] Applications of the resin particles according to this embodiment include cosmetic base materials, rolling agents, abrasives, scrubbing agents, display spacers, materials for forming beads, light diffusing particles, resin reinforcing agents, refractive index control agents, biodegradation accelerators, fertilizers, water absorbing particles, and granular toner particles. EXAMPLES

[0136] The resin particles according to this embodiment will be described in more detail below with reference to examples. The materials, amounts, ratios, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the resin particles according to this embodiment should not be interpreted as being limited by the specific examples shown below.

[0137] Here, "*" in Tables 1 to 4 means that it is outside the scope of the preferred embodiments of the present invention.

[0138] <Preparing each ingredient> The following materials were prepared:

[0139] (Component (A)) CA1: Eastman Chemical "CAP482-20", cellulose acetate propionate, weight average degree of polymerization 716, acetyl group substitution degree 0.18, propionyl group substitution degree 2.49. CA2: Eastman Chemical "CAB381-20", cellulose acetate butyrate, weight average degree of polymerization 595, acetyl substitution degree 0.15, butyryl substitution degree 1.74. · CA3: Daicel "L-20", cellulose acetate, weight average degree of polymerization 450, acetyl group substitution degree 2.50.

[0140] (Component (B)) PHC1: Cardolite "NX-2503", hydroxyethylated cardanol, molecular weight 296-320 · PHC2: Cardolite "Ultra LITE 513", glycidyl ether of cardanol, molecular weight 354-361. ·PHC3: Idemitsu Showa Shell "Bisphenol A" PHC4: Tokyo Chemical Industry "Phenol" PHC5: Mitsubishi Chemical "ODA", dioctyl adipate

[0141] (Component (C)) EC1: Kao "Excelpearl SS", stearyl stearate EC2: Tokyo Chemical Industry "Cetyl stearate" EC3: High-grade alcohol industry "EHC", 2-ethylhexanoic acid cetyl EC4: Tokyo Chemical Industry "Ethyl Acetate" ·EC5: Dodecyl octylate ·EC6: Dodecyl icosylates EC7: Henicosyl dodecyl ester

[0142] <Preparation of resin pellets RE1 to RE30> The cylinder temperature was adjusted based on the charged composition ratios shown in Tables 1 and 2, and kneading was carried out using a twin-screw kneader (TEX41SS, manufactured by Toshiba Machine Co., Ltd.) to produce pellet-shaped resins RE1 to RE30 (hereinafter referred to as resin pellets RE1 to RE30). In addition, "-" in Table 2 indicates that the corresponding component is not contained, or that the corresponding value has not been calculated because component (B) or component (C) is not contained.

[0143] <Example 1> (Preparation of resin particles RPC1) 300 parts by mass of resin pellets (RE1) were completely dissolved in 700 parts by mass of methyl ethyl ketone. This was added to an aqueous liquid in which 100 parts by mass of calcium carbonate, 4 parts by mass of carboxymethyl cellulose, and 200 parts by mass of methyl ethyl ketone were dispersed in 1100 parts by mass of pure water, and the mixture was stirred for 3 hours. 10 parts by mass of sodium hydroxide was added to this, and the mixture was heated to 80°C and stirred for 3 hours to remove the methyl ethyl ketone. After filtering the residue, the solid content was freeze-dried to obtain resin particles RPC1.

[0144] <Examples 2 to 27 and Comparative Examples 1 to 12> (Preparation of resin particles RPC2-37) Resin particles RPC2 to 37 were obtained in the same manner as resin particle RPC1, except that the resin pellets, the amount of each component in the aqueous liquid (amount of calcium carbonate, amount of carboxymethyl cellulose, amount of methyl ethyl ketone), the stirring time of the aqueous liquid, and the amount of sodium hydroxide added were changed in accordance with Tables 3 and 4.

[0145] (Preparation of resin particles RPC38 and 39) Commercially available cellulose particles, CELLULOBEADS D10 (manufactured by Daito Kasei) were prepared as resin particles RPC38, and BELLOCEA (manufactured by Daicel) were prepared as resin particles RPC39.

[0146] <Particle size, particle size distribution, hydrophobicity> According to the method described above, the volume average particle size and the large particle size distribution index GSDv of the resin particles were measured using an LS particle size distribution measuring device Beckman Coulter LS13 320 (manufactured by Beckman Coulter, Inc.). The degree of hydrophobicity was measured according to the method already described.

[0147] <Mass reduction rate> The mass loss rate of the obtained resin particles was measured by the following procedure.

[0148] -Measurement of mass loss rate of resin particles- 50 g of the obtained resin particles were sealed in a bag made of #508 / 585-1μ nylon mesh (mesh size 1μm) and immersed in distilled water adjusted to 50℃ and pH 7.8 for 90 days. After that, the nylon mesh containing the resin particles was removed and the resin particles in the nylon mesh were vacuum dried. The mass of the resin particles after vacuum drying was measured, and the mass reduction rate of the resin particles was measured.

[0149] <Measurement of biodegradability> Using the obtained resin particles, the aerobic biodegradability was measured according to a method conforming to ISO-14855-2 (2018), and the anaerobic biodegradability was measured according to a method conforming to ISO-14853 (2016). The time required to reach 50% and 90% biodegradability was evaluated as the biodegradation rate.

[0150] [Table 1]

[0151] [Table 2]

[0152] [Table 3]

[0153] [Table 4]

[0154] From the above results, it is apparent that the resin particles of this example have excellent resistance to hydrolysis in water while being biodegradable.

Claims

1. Cellulose acylate (A), an aromatic compound (B) which does not have a functional group reactive with the cellulose acylate (A) and has, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; (C) an ester compound having a long chain hydrocarbon group, a mass ratio ((B) / (A)) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more and 0.8 or less; a mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is 0.03 or more and 0.10 or less; The acyl group contained in the cellulose acylate (A) is an unsubstituted acyl group, the resin particles do not contain any other resin than the cellulose acylate (A) and the aromatic compound (B), or the content of the other resin is 5% by mass or less based on the total amount of the resin particles; The resin particles have a volume average particle size of 3 μm or more and 100 μm or less, The resin particles have a large particle size distribution index GSDv of 1.50 or less.

2. 2. The resin particles according to claim 1, wherein the cellulose acylate (A) is a cellulose acylate having two or more kinds of acyl groups.

3. The resin particles according to claim 1 or 2, wherein the aromatic compound (B) is a cardanol compound (B1).

4. The resin particles according to claim 3, wherein the cardanol compound (B1) is at least one compound selected from the group consisting of compounds represented by the following general formula (CDN1) and compounds represented by the following general formula (CDN1-e): 【Chemistry 1】 (In general formula (CDN1), R １ R represents an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and may have a substituent. ２ represents a hydroxy group, a carboxy group, an alkyl group which may have a substituent, or an unsaturated aliphatic group which has a double bond and may have a substituent. P2 represents an integer of 0 to 4. When P2 is 2 or more, a plurality of R ２ may be the same group or different groups.) 【Chemistry 2】 (In the general formula (CDN1-e), L ＥＰ represents a single bond or a divalent linking group. １ , R ２ and P2 are each R in general formula (CDN1). １ , R ２ and P2.)

5. 5. The resin particle according to claim 1, wherein the ester compound (C) is an ester compound having two or more long-chain hydrocarbon groups.

6. The resin particle according to claim 5 , wherein the two or more long-chain hydrocarbon groups contained in the ester compound (C) are hydrocarbon groups having 8 to 20 carbon atoms.

7. The resin particle according to claim 6 , wherein at least one of the two or more hydrocarbon groups having 8 to 20 carbon atoms contained in the ester compound (C) is a stearyl group.

8. The mass ratio of the cellulose acylate (A) to the aromatic compound (B) ((B) / (A)) The resin particles according to any one of claims 1 to 7, wherein the value is 0.20 or more and 0.40 or less.

9. 9. The resin particles according to claim 1, wherein a mass ratio ((C) / (A)) of the cellulose acylate (A) to the ester compound (C) is 0.03 or more and 0.07 or less.

10. Cellulose acylate (A), an aromatic compound (B) having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; (C) an ester compound having a long chain hydrocarbon group, The mass loss rate after 90 days in water at 50°C and pH 7.8 is 16% or less, The acyl group contained in the cellulose acylate (A) is an unsubstituted acyl group, The resin particles have a volume average particle size of 3 μm or more and 100 μm or less, The resin particles have a large particle size distribution index GSDv of 1.50 or less.

11. Cellulose acylate (A), an aromatic compound (B) having, together with a long-chain aliphatic group, at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group; (C) an ester compound having a long chain hydrocarbon group, The hydrophobicity measured by the following method is 50 or more, The acyl group contained in the cellulose acylate (A) is an unsubstituted acyl group, The resin particles have a volume average particle size of 3 μm or more and 100 μm or less, The resin particles have a large particle size distribution index GSDv of 1.50 or less. (Method of measuring hydrophobicity) 50 g of distilled water is placed in a 300 ml beaker and stirred with a stirrer. 0.2 g of resin particles is placed in the beaker and dispersed in the distilled water. Methanol is added dropwise to the beaker using a dropper. The amount of methanol dropped when all the resin particles have settled is designated as Me (g), and the hydrophobicity is calculated according to the following formula. Hydrophobicity=Me / (Me+50)

12. The resin particles according to any one of claims 1 to 11, wherein the acyl group of the cellulose acylate (A) is at least one selected from the group consisting of an acetyl group, a propionyl group, a butyryl group, and a hexanoyl group.

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