阅读说明：本技术 树脂组合物和树脂成型体 (Resin composition and resin molded article ) 是由 八百健二 吉川英昭 于 2020-06-08 设计创作，主要内容包括：本申请涉及树脂组合物和树脂成型体。树脂组合物含有纤维素酰化物(A)以及芳香族化合物(B),该芳香族化合物(B)不具有与上述纤维素酰化物(A)反应的官能团,具有长链脂肪族基团并且具有酚羟基以及与芳香族化合物(B)的芳香族基团直接键合的单缩水甘油醚基中的至少一者,上述纤维素酰化物(A)与上述芳香族化合物(B)的质量比(B)/(A)为0.15以上。(The present application relates to a resin composition and a resin molded body. The resin composition contains a cellulose acylate (A) and an aromatic compound (B) which has no functional group reactive 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 directly bonded to an aromatic group of the aromatic compound (B), wherein the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more.)

1. A resin composition, wherein the composition comprises:

cellulose acylate (A), and

an aromatic compound (B) having no functional group that reacts with the cellulose acylate (A), but having a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B),

the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more.

2. The resin composition according to claim 1, wherein the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is from 0.15 to 0.80.

3. The resin composition according to claim 1 or claim 2, wherein the cellulose acylate (a) is at least one selected from the group consisting of cellulose acetate propionate and cellulose acetate butyrate.

4. The resin composition according to any one of claims 1 to 3, wherein the aromatic compound (B) is a cardanol compound (B1).

5. The resin composition according to claim 4, wherein 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 polymer obtained by polymerizing a compound represented by the general formula (CDN1),

[ solution 1]

In the general formula (CDN1), R¹Represents an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and having a double bond, R²Represents a hydroxyl group, a carboxyl group, an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and having a double bond, P2 represents an integer of 0 to 4, and when P2 is 2 or more, a plurality of R' s²Are the same group or are different groups.

6. A resin composition, wherein the composition comprises:

cellulose acylate (A), and

an aromatic compound (B) having no functional group that reacts with the cellulose acylate (A), but having a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B),

the solubility of the resin composition in methyl ethyl ketone at a liquid temperature of 25 ℃ is 200mg/ml or more.

7. A resin molded article comprising the resin composition according to any one of claims 1 to 6.

8. The resin molded body according to claim 7, which is a granular body.

9. The resin molded body according to claim 8, wherein the volume average particle diameter of the particulate body is 3 μm or more and 100 μm or less.

10. The resin molded body according to claim 8 or claim 9, wherein the particle size distribution index GSD on the large diameter side of the particle is_VIs 1.5 or less.

Technical Field

The present invention relates to a resin composition and a resin molded article.

Background

Patent document 1 discloses "a liquid or cream-like cosmetic composition containing 1.0 to 40% by weight of fine cellulose particles and/or fine cellulose composite particles having an average particle diameter of 0.2 to 20 μm and an L/D (L represents a long diameter of the cellulose particles or the composite particles, and D represents a short diameter) of 1.30 or less".

Patent document 2 discloses "a scouring agent containing porous cellulose particles, wherein the particle diameter is 100 μm or more and 1,000 μm or less in terms of median diameter, the specific gravity of the wool is 0.38g/ml or more and 0.55g/ml or less, and the biodegradation rate is 50 wt% or more within 10 days".

Patent document 3 discloses "a cellulose-based resin obtained by binding a cardanol analog or a derivative thereof containing 3.0 wt% or more of cardanol and ginkgol with a cellulose or a derivative thereof and a hydroxyl group of the cellulose or the derivative thereof and a phenolic hydroxyl group of the cardanol derivative".

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2000-309503

Patent document 2: japanese patent laid-open publication No. 2018-118917

Patent document 3: japanese patent laid-open publication No. 2015-081326

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a resin composition which can obtain a resin molded product having a high biodegradation rate, in comparison with a case where the mass ratio (B)/(a) of cellulose acylate (a) to aromatic compound (B) is less than 0.15 or a case where the solubility of the resin composition in methyl ethyl ketone is less than 200mg/ml in a resin composition which contains cellulose acylate (a) and aromatic compound (B) and which does not have a functional group reactive with the cellulose acylate (a), but has a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B).

Means for solving the problems

Specific means for solving the above technical problems include the following solutions.

[1]

A resin composition, wherein the composition comprises:

cellulose acylate (A), and

an aromatic compound (B) which has no functional group that 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 directly bonded to an aromatic group of the aromatic compound (B),

the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more.

[2]

The resin composition as described in [1], wherein the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is from 0.15 to 0.80.

[3]

The resin composition according to [1] or [2], wherein the cellulose acylate (A) is at least one selected from the group consisting of cellulose acetate propionate and cellulose acetate butyrate.

[4]

The resin composition according to any one of [1] to [3], wherein the aromatic compound (B) is a cardanol compound (B1).

[5]

The resin composition according to [4], wherein 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 polymer obtained by polymerizing a compound represented by the general formula (CDN 1).

(general formula (CDN1) wherein R¹Represents an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and having a double bond. R²Represents a hydroxyl group, a carboxyl group, an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and a double bond. P2 represents an integer of 0 to 4. When P2 is 2 or more, plural Rs²May or may not be the same groupThe same groups. )

[6]

A resin composition, wherein the composition comprises:

cellulose acylate (A), and

an aromatic compound (B) which has no functional group that 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 directly bonded to an aromatic group of the aromatic compound (B),

the solubility of the resin composition in methyl ethyl ketone at a liquid temperature of 25 ℃ is 200mg/ml or more.

[7]

A resin molded article comprising the resin composition according to any one of [1] to [6 ].

[8]

The resin molded article according to [7], which is a granular article.

[9]

The resin molded body as described in [8], wherein the volume average particle diameter of the particulate body is 3 μm or more and 100 μm or less.

[10]

The resin molded body according to [8] or [9], wherein the particle size distribution index GSDv on the large diameter side of the particles is 1.5 or less.

Effects of the invention

According to the aspect of [1], [4] or [5], there is provided a resin composition which can give a molded resin article having a high biodegradation rate, as compared with the case where the mass ratio (B)/(a) of cellulose acylate (a) to aromatic compound (B) is less than 0.15 in a resin composition which contains cellulose acylate (a) and aromatic compound (B) and in which the aromatic compound (B) does not have a functional group reactive with the cellulose acylate (a) but has a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B).

According to the aspect of [2], there is provided a resin composition which can give a resin molded product having a high biodegradation rate, as compared with the case where the mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is less than 0.15; this composition can provide a resin molded article in which the biodegradation rate is suppressed too fast, as compared with the case where the mass ratio is more than 0.80.

According to the aspect [3], there is provided a resin composition which can give a resin molded product having a higher biodegradation rate than a resin molded product having a cellulose acylate (A) of diacetylcellulose or triacetylcellulose.

According to the aspect of [6], there is provided a resin composition which can give a molded resin product having a higher biodegradation rate than that in a resin composition containing a cellulose acylate (a) and an aromatic compound (B) having no functional group reactive with the cellulose acylate (a), but having a long-chain aliphatic group, a phenolic hydroxyl group, and at least one of a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B), wherein the solubility of the resin composition in methyl ethyl ketone is less than 200 mg/ml.

According to the aspect of [7] or [8], there is provided a resin molded article having a higher biodegradation rate than that in a resin molded article containing a cellulose acylate (a) and an aromatic compound (B) which does not have a functional group reactive with the cellulose acylate (a) but has a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B), wherein the mass ratio (B)/(a) of the cellulose acylate (a) to the aromatic compound (B) is less than 0.15 or the solubility of the resin composition in methyl ethyl ketone is less than 200 mg/ml.

According to the aspect of [9], there is provided a granular material having a higher biodegradation rate as a resin molded body than in the case of a granular material having a volume average particle diameter of less than 3 μm or more than 100 μm.

According to the aspect [10], there is provided a granular material having a higher biodegradation rate as a resin molded article than a granular material having a large-diameter side particle size distribution index GSDv of more than 1.5.

Detailed Description

An embodiment of the present invention will be described below. The description and examples are intended to illustrate embodiments and are not intended to limit the scope of the embodiments.

In the numerical ranges recited in the present specification in stages, the upper limit or the lower limit recited in one numerical range may be replaced with the upper limit or the lower limit recited in another numerical range in another stage. In the numerical ranges described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.

The term "step" in the present specification includes not only an independent step but also a step that can achieve a desired purpose even when it cannot be clearly distinguished from other steps.

Each component may comprise two or more corresponding substances.

In the case where the amount of each component in the composition is referred to, in the case where two or more species corresponding to each component are present in the composition, the total amount of the two or more species present in the composition is referred to unless otherwise specified.

"(meth) acrylic acid" means at least one of acrylic acid and methacrylic acid, and "(meth) acrylate" means at least one of acrylate and methacrylate.

In the present specification, the cellulose acylate (a) and the aromatic compound (B) are also referred to as a component (a) and a component (B), respectively.

< resin composition >

First embodiment

The resin composition of the first embodiment contains a cellulose acylate (a) and an aromatic compound (B) which has no functional group reactive 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 directly bonded to an aromatic group of the aromatic compound (B).

The mass ratio (B)/(A) of the cellulose acylate (A) to the aromatic compound (B) is 0.15 or more.

In recent years, resin compositions containing components of biological origin have been widely used in place of petroleum for the purpose of constructing a sustainable society, such as suppression of global warming and conservation of exhausted resources.

In particular, environmental pollution and destruction of biological systems, such as marine plastic waste, have been generated, and biodegradable resin molded articles derived from organisms have been sought.

On the other hand, many biodegradable resin molded articles such as cellulose and polylactic acid have been reported.

However, these have insufficient biodegradation rate and long environmental residence time, and are either predated before decomposition or easily predated by the reduced shape after decomposition.

In contrast, the resin composition of the first embodiment has the above-described configuration, and thus a resin molded body having high biodegradability can be obtained. The reason for this is presumed as follows.

The cellulose acylate (a) (component (a)) is a biodegradable compound. The mechanism is that the molecular chain starts to be shortened by hydrolysis of the component (a), and after reaching a certain length, biodegradation by microorganisms starts, and finally water, carbon dioxide, and acid are produced.

In order to hydrolyze the molecular chain of the component (a) into a biodegradable length, a certain degree of time is required. This is one of the reasons why the biodegradation rate becomes slow.

In addition, since the hydrolysis of component (A) occurs randomly, a distribution of long and short chains results after decomposition, the short chains being relatively rapidly biodegradable, but the long chains still remaining. This also causes the rate of biodegradation not to be increased.

On the other hand, when a resin composition containing a cellulose acylate (a) (component (a)) and an aromatic compound (B) (component (B)) is brought into contact with an appropriate temperature and moisture such as compost (composition) or with an alkaline atmosphere and moisture such as seawater, since the component (B) has a relatively long-chain aliphatic group, the monoglycidyl ether group or phenolic hydroxyl group (hereinafter also referred to as "epoxy group or hydroxyl group") of the component (B) is weak in binding force and high in activity. Thus, hydrolysis of the component (A) is promoted.

When the mass ratio (B)/(a) of the component (a) to the component (B) is 0.15 or more, the hydrolysis acceleration action of the component (a) due to the epoxy group or the hydroxyl group of the aromatic compound (B) increases, and the biodegradation rate of the obtained resin molded product increases.

As can be understood from the above, in the resin composition of the first embodiment, the resin molded body having high biodegradability can be obtained by the above configuration.

Second embodiment

The resin composition of the second embodiment contains a cellulose acylate (a) and an aromatic compound (B) having no functional group reactive with the cellulose acylate (a), having a long-chain aliphatic group and at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B).

The solubility of the resin composition in methyl ethyl ketone at a liquid temperature of 25 ℃ is 200mg/ml or more.

In the resin composition of the second embodiment, a resin molded body having high biodegradability can be obtained by the above configuration. The reason for this is presumed as follows.

Cellulose acylate (a) alone is difficult to dissolve in methyl ethyl ketone. On the other hand, a resin composition in which the aromatic compound (B) is mixed with the cellulose acylate (a) has high solubility in methyl ethyl ketone.

When the solubility of the resin composition in methyl ethyl ketone at a liquid temperature of 25 ℃ is 200mg/ml or more, the intermolecular force of the cellulose acylate (a) is weak, and the aromatic compound (B) is easily mixed into the intermolecular force of the cellulose acylate (a), so that the acceleration action of the epoxy group or hydroxyl group of the aromatic compound (B) on the hydrolysis of the component (a) increases as described above, and the biodegradation rate of the obtained resin molded product becomes high.

As can be understood from the above, in the resin composition of the second embodiment, the resin molded body having high biodegradability can be obtained by the above configuration.

The following describes in detail a resin composition according to both the first and second embodiments (hereinafter also referred to as "resin composition of the present embodiment"). However, an example of the toner of the present invention may be a toner corresponding to any one of the resin compositions of the first and second embodiments.

The resin composition of the present embodiment will be described in detail below.

[ cellulose acylate (A): component (A) ]

The cellulose acylate (a) is a cellulose derivative in which at least a part of hydroxyl groups in cellulose is substituted (acylated) with an acyl group. Acyl is of the formula-CO-R^AC(R^ACA hydrogen atom or a hydrocarbon group).

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

In the general formula (CA), A¹、A²And A³Each independently represents a hydrogen atom or an acyl group, and n represents an integer of 2 or more. Wherein n is A¹N number of A²And n is A³At least a part of (a) represents an acyl group. N A in the molecule¹May be all the same, may be partially the same, or may be different from each other. Likewise, n A's in the molecule²And n is A³They may be the same or partially the same or different from each other.

A¹、A²And A³In the acyl group, the hydrocarbon group in the acyl group may be linear, branched or cyclic, preferably linear or branched, more preferably linear.

A¹、A²And A³In the acyl group, the hydrocarbon group in the acyl group may be a saturated hydrocarbon group or a saturated hydrocarbon groupMay be an unsaturated hydrocarbon group, and is more preferably a saturated hydrocarbon group.

A¹、A²And A³Among the acyl groups, preferred is an acyl group having 1 to 6 carbon atoms. That is, as the cellulose acylate (a), a cellulose acylate (a) in which the carbon number of the acyl group is 1 to 6 is preferable. When the cellulose acylate (a) contains an acyl group having 1 to 6 carbon atoms, a resin molded product having excellent impact resistance can be easily obtained as compared with a case where the cellulose acylate (a) contains an acyl group having 7 or more carbon atoms.

A¹、A²And A³The acyl group represented may be a group in which a hydrogen atom in the acyl group is substituted with a halogen atom (e.g., a fluorine atom, a bromine atom, an iodine atom), an oxygen atom, a nitrogen atom, or the like, and is preferably unsubstituted.

As A¹、A²And A³Examples of the acyl group include formyl, acetyl, propionyl, butyryl, acryloyl, and hexanoyl. Among these, the acyl group is preferably an acyl group having 2 to 4 carbon atoms, more preferably an acyl group having 2 or 3 carbon atoms, because moldability of the resin composition and biodegradation rate of the resin molded article are improved.

Examples of the cellulose acylate (a) include cellulose acetate (mono-acetate, Diacetate (DAC), triacetate), acetate propionate (CAP), acetate butyrate (CAB), and the like.

The cellulose acylate (a) is preferably Cellulose Acetate Propionate (CAP) or Cellulose Acetate Butyrate (CAB), and more preferably Cellulose Acetate Propionate (CAP), from the viewpoint of increasing the biodegradation rate of the resin molded body.

The cellulose acylate (A) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The weight-average polymerization degree of the cellulose acylate (a) is preferably 200 to 1000, more preferably 500 to 1000, and even more preferably 600 to 1000, from the viewpoint of excellent moldability of the resin composition, impact resistance of the resin molded article, or toughness of the resin molded article.

The weight-average degree of polymerization of the cellulose acylate (a) can be determined from the weight-average molecular weight (Mw) by the following procedure.

First, the weight average molecular weight (Mw) of the cellulose acylate (A) was measured in terms of polystyrene using tetrahydrofuran and a gel permeation chromatography apparatus (GPC apparatus: HLC-8320GPC, manufactured by Tosoh Corp., column: TSKgel. alpha. -M).

Next, the polymerization degree of the cellulose acylate (a) is determined by dividing the weight average molecular weight by the molecular weight of the structural unit of the cellulose acylate (a). For example, when the substituent of the cellulose acylate is an acetyl group, the molecular weight of the structural unit is 263 when the substitution degree is 2.4, and 284 when the substitution degree is 2.9.

The degree of substitution of the cellulose acylate (a) is preferably 2.1 to 2.9, more preferably 2.2 to 2.9, even more preferably 2.3 to 2.9, and particularly preferably 2.6 to 2.9, in view of improving moldability of the resin composition and a biodegradation rate of the resin molded article.

In Cellulose Acetate Propionate (CAP), the ratio of the substitution degrees of acetyl group and propionyl group (acetyl group/propionyl group) is preferably 0.01 to 1, more preferably 0.05 to 0.1, from the viewpoint of improving the moldability of the resin composition and the biodegradation rate of the resin molded product.

In Cellulose Acetate Butyrate (CAB), the ratio of the degrees of substitution of acetyl groups and butyryl groups (acetyl/butyryl groups) is preferably 0.05 to 3.5, more preferably 0.5 to 3.0, from the viewpoint of improving moldability of the resin composition and the rate of biodegradation of the resin molded article.

The degree of substitution of the cellulose acylate (a) is an index indicating the degree of substitution of the hydroxyl group of the cellulose with the acyl group. That is, the degree of substitution is an index indicating the degree of acylation of the cellulose acylate (a). Specifically, the substitution degree is an intramolecular average of the number of substitutions of 3 hydroxyl groups in the D-glucopyranose unit of the cellulose acylate by the acyl group. Degree of substitution utilization¹H-NMR (manufactured by JMN-ECA/JEOL RESONANCE Co., Ltd.) peaks of hydrogen derived from cellulose and hydrogen derived from acyl groupThe integral ratio of (a) to (b).

[ aromatic Compound (B): component (B) ]

The aromatic compound (B) is an aromatic compound having no functional group reactive with the cellulose acylate (a) but having a long-chain aliphatic group and having at least one of a phenolic hydroxyl group and a monoglycidyl ether group directly bonded to an aromatic group of the aromatic compound (B).

That is, the aromatic compound (B) is a compound having no functional group that reacts with the cellulose acylate (a), having a long-chain aliphatic group, and having at least one of a phenolic hydroxyl group and a monoglycidyl ether group.

Examples of the long-chain aliphatic group include a saturated aliphatic group (alkyl group) having preferably 6 to 30 carbon atoms, and more preferably 10 to 20 carbon atoms, and an unsaturated aliphatic group (alkenyl group and alkynyl group). The aliphatic group may be linear, branched or cyclic, and is preferably linear or branched, more preferably linear.

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 2 or more aromatic rings), a polycyclic ring (a polycyclic ring in which aromatic rings are bonded to each other via a carbon-carbon bond), a heterocyclic ring (a heterocyclic monocyclic ring, a condensed ring including a heterocyclic ring, a polycyclic ring including a heterocyclic ring, etc.) together with a long-chain aliphatic group.

Specific examples of the aromatic compound (B) include cardanol compounds, phenol alkylamine compounds, phenol resins, novolac-type epoxy resins, resol-type epoxy resins, phenol-modified palm oil, phenol-modified soybean oil, and phenol-modified linseed oil.

Among these, cardanol compound (B1) is preferable as aromatic compound (B) in terms of improving biodegradability.

The cardanol compound (B1) is a component contained in a compound derived from a natural source using cashew nuts as a raw material (for example, a compound represented by the following structural formulae (B-1) to (B-4)) or a derivative derived from the component.

The cardanol compound (B1) may be a mixture of compounds derived from natural sources using cashews as a raw material (hereinafter also referred to as "cashew-derived mixture").

The cardanol compound (B1) may be a derivative from a mixture of cashew sources. Examples of the derivative derived from the mixture derived from cashew nuts include the following mixture and single substance ( mer).

Mixture with adjusted composition ratio of each component in cashew nut-derived mixture

Separating only a single specific component from the mixture of cashew nuts

A mixture containing a modified product obtained by modifying a component of the cashew nut-derived mixture

Mixture containing polymer obtained by polymerizing components in cashew nut-derived mixture

A mixture containing a modified polymer obtained by modifying and polymerizing components in the cashew nut-derived mixture

A mixture containing a modified product obtained by further modifying the components in the mixture having the above composition ratio adjusted

A mixture containing a polymer obtained by further polymerizing the components in the mixture having the above-mentioned composition ratio adjusted

A mixture containing a modified polymer obtained by modifying and polymerizing the components in the mixture having the above composition ratio adjusted

A modified product obtained by further modifying the isolated single product

A polymer obtained by further polymerizing the above-separated monomer

A modified polymer obtained by further modifying and polymerizing the above-mentioned separated monomer

The single substance herein also includes multimers such as dimers and trimers.

From the viewpoint of increasing the biodegradation rate of the resin molded product, the cardanol compound (B1) is preferably at least one compound selected from the group consisting of a compound represented by general formula (CDN1) and a polymer obtained by polymerizing a compound represented by general formula (CDN 1).

In the general formula (CDN1), R¹Represents an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and having a double bond. R²Represents a hydroxyl group, a carboxyl group, an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and a double bond. P2 represents an integer of 0 to 4. When P2 is 2 or more, plural Rs²The groups may be the same or different.

In the general formula (CDN1), R¹The alkyl group having a substituent(s) is preferably an alkyl group having 3 to 30 carbon atoms, more preferably an alkyl group having 5 to 25 carbon atoms, and still more preferably an alkyl group having 8 to 20 carbon atoms.

Examples of the substituent include: a hydroxyl group; an ether bond-containing substituent such as an epoxy group or a methoxy group; substituents containing ester bonds such as acetyl and propionyl; and so on.

Examples of the alkyl group which may have a substituent include pentadecan-1-yl, heptane-1-yl, octane-1-yl, nonane-1-yl, decane-1-yl, undecane-1-yl, dodecane-1-yl, tetradecane-1-yl, and the like.

In the general formula (CDN1), R¹The unsaturated aliphatic group having a double bond and having or not having a substituent 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 still more preferably an unsaturated aliphatic group having 8 to 20 carbon atoms.

The number of double bonds of the unsaturated aliphatic group is preferably 1 to 3.

Examples of the substituent include those listed as substituents for the above-mentioned alkyl groups.

Examples of the unsaturated aliphatic group having a double bond and having or not having a substituent include pentadec-8-en-1-yl, pentadec-8, 11-dien-1-yl, pentadec-8, 11, 14-trien-1-yl, pentadec-7-en-1-yl, pentadec-7, 10-dien-1-yl, pentadec-7, 10, 14-trien-1-yl, and the like.

In the general formula (CDN1), as R¹Pentadec-8-en-1-yl, pentadec-8, 11-dien-1-yl, pentadec-8, 11, 14-trien-1-yl, pentadec-7-en-1-yl, pentadec-7, 10-dien-1-yl, pentadec-7, 10, 14-trien-1-yl are preferred.

In the general formula (CDN1), as R²The above-mentioned R is the same as the above-mentioned alkyl group having a substituent or not and the unsaturated aliphatic group having a double bond and having a substituent or not¹The groups listed as the alkyl group having or not having a substituent and the unsaturated aliphatic group having a double bond and having or not having a substituent are preferable examples.

The compound represented by the general formula (CDN1) may be further modified. For example, epoxidation may be carried out, specifically, a compound having a structure in which a hydroxyl group of a compound represented by the general formula (CDN1) is substituted with the following group (EP), that is, a compound represented by the general formula (CDN 1-e).

In the radical (EP) and the general formula (CDN1-e), L_EPRepresents a single bond or a 2-valent linking group. In the general formula (CDN1-e), R¹、R²And P2 with R in formula (CDN1), respectively¹、R²And P2.

In the group (EP) and the general formula (CDN1-e), as L_EPExamples of the 2-valent linking group include an alkylene group (preferably an alkylene group having 1 to 4 carbon atoms, more preferably an alkylene group having 1 carbon atom) having or not having a substituent, and-CH₂CH₂OCH₂CH₂-radicals and the like.

The substituent may be R in the general formula (CDN1)¹The groups listed as substituents in (1).

As L_EPMethylene is preferred.

The polymer obtained by polymerizing the compound represented by the general formula (CDN1) means a polymer obtained by polymerizing at least 2 or more compounds represented by the general formula (CDN1) with or without a linking group.

Examples of the polymer obtained by polymerizing the compound represented by the general formula (CDN1) include a compound represented by the following general formula (CDN 2).

In the general formula (CDN2), R¹¹、R¹²And R¹³Each independently represents an alkyl group having or not having a substituent, or an unsaturated aliphatic group having a double bond and having or not having a substituent. R²¹、R²²And R²³Each independently represents a hydroxyl group, a carboxyl group, an alkyl group with or without a substituent, or an unsaturated aliphatic group with or without a substituent and having a double bond. P21 and P23 each independently represent an integer of 0 to 3, and P22 represents an integer of 0 to 2. L is¹And L²Each independently represents a 2-valent linking group. n represents an integer of 0 to 10 inclusive. When P21 is 2 or more, plural R²¹And when P22 is 2 or more, plural R²²And a plurality of R when P23 is 2 or more²³The groups may be the same or different. When n is 2 or more, plural R¹²、R²²And L¹Each of P22 may be the same or different, and when n is 2 or more, P22 may be the same or different.

In the general formula (CDN2), as R¹¹、R¹²、R¹³、R²¹、R²²And R²³Examples of the substituted or unsubstituted alkyl group and the double-bonded substituted or unsubstituted unsaturated aliphatic group include R of the general formula (CDN1)¹The groups listed are preferred examples.

In the general formula (CDN2), as L¹And L²Examples of the 2-valent linking group include an alkylene group (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms) which may have a substituent, and the like.

Examples of the substituent include R in the general formula (CDN1)¹The substituents listed in (1) above are the substituents.

In the general formula (CDN2), n is preferably 1 to 10, more preferably 1 to 5.

The compound represented by the general formula (CDN2) may be further modified. For example, epoxidation may be carried out, specifically, a compound having a structure in which a hydroxyl group of a compound represented by general formula (CDN2) is substituted with a group (EP), that is, a compound represented by general formula (CDN2-e) below.

In the general formula (CDN2-e), R¹¹、R¹²、R¹³、R²¹、R²²、R²³、P21、P22、P23、L¹、L²And n is independently from R in formula (CDN2)¹¹、R¹²、R¹³、R²¹、R²²、R²³、P21、P22、P23、L¹、L²And n have the same meaning.

In the general formula (CDN2-e), L_EP1、L_EP2And L_EP3Each independently represents a single bond or a 2-valent linking group. When n is 2 or more, a plurality of L_EP2The groups may be the same or different.

In the general formula (CDN2-e), as L_EP1、L_EP2And L_EP3A 2-valent linking group representedLikewise, L in the general formula (CDN1-e) can be mentioned_EPThe groups listed as the 2-valent linking groups are preferred examples.

The polymer obtained by polymerizing the compound represented by the general formula (CDN1) may be, for example, a polymer obtained by three-dimensionally crosslinking and polymerizing at least 3 or more compounds represented by the general formula (CDN1) with or without a linking group. Examples of the polymer obtained by three-dimensionally crosslinking and polymerizing the compound represented by the general formula (CDN1) include compounds represented by the following structural formulae.

In the above structural formula, R¹⁰、R²⁰And P20 with R in formula (CDN1), respectively¹、R²And P2. L is¹⁰Represents a single bond or a 2-valent linking group. Plural R¹⁰、R²⁰And L¹⁰The groups may be the same or different. The P20 s may be the same number or different numbers.

In the above structural formula, as L¹⁰Examples of the 2-valent linking group include an alkylene group (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms) which may have a substituent, and the like.

The substituent may be R in the general formula (CDN1)¹The groups listed as substituents in (1).

The compound represented by the above structural formula may be further modified, for example, may be epoxidized. Specifically, examples of the compound having a structure in which a hydroxyl group of the compound represented by the above structural formula is substituted with a group (EP) include a polymer obtained by three-dimensionally crosslinking and polymerizing a compound represented by the following structural formula, i.e., a compound represented by the general formula (CDN 1-e).

In the above structural formula, R¹⁰、R²⁰And P20 with R in the general formula (CDN1-e), respectively¹、R²And P2. L is¹⁰Represents a single bond or a 2-valent linking group. Plural R¹⁰、R²⁰And L¹⁰The groups may be the same or different. The P20 s may be the same number or different numbers.

In the above structural formula, as L¹⁰Examples of the 2-valent linking group include an alkylene group (preferably an alkylene group having 2 to 30 carbon atoms, more preferably an alkylene group having 5 to 20 carbon atoms) which may have a substituent, and the like.

The substituent may be R in the general formula (CDN1)¹The groups listed as substituents in (1).

The cardanol compound (B1) preferably contains a cardanol compound having an epoxy group (B1), and more preferably a cardanol compound having an epoxy group (B1), from the viewpoint of improving the transparency of the resin molded body.

As the cardanol compound (B1), a commercially available product can be used. 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, NX-9203, LB-7000, LB-7250 and CD-5L, which are available from Cardolite corporation. Examples of commercially available products of epoxy group-containing cardanol compounds include NC-513, NC-514S, NC-547, LITE513E, and Ultra LTE 513 manufactured by Cardolite corporation.

From the viewpoint of increasing the biodegradation rate of the resin molded product, the hydroxyl value of the cardanol compound (B1) is preferably 100mgKOH/g or more, more preferably 120mgKOH/g or more, and still more preferably 150mgKOH/g or more. The measurement of the hydroxyl value of the cardanol compound (B1) was performed according to method a of ISO 14900.

When a cardanol compound (B1) having an epoxy group is used as the cardanol compound (B1), the epoxy equivalent weight thereof is preferably 300 to 500, more preferably 350 to 480, and further preferably 400 to 470, from the viewpoint of improving the transparency of the resin molded product. The epoxy equivalent of the cardanol compound having an epoxy group (B1) was measured according to ISO 3001.

From the viewpoint of increasing the biodegradation rate of the resin molded product, the molecular weight of the cardanol compound (B1) is preferably 250 to 1000, more preferably 280 to 800, and even more preferably 300 to 500.

The cardanol compound (B1) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

[ content or mass ratio of component (A) to component (B) ]

The abbreviations for the respective components are as follows.

Component (A) ═ cellulose acylate (A)

Component (B) ═ aromatic compound (B)

The mass ratio (B)/(A) of the component (A) to the component (B) is 0.15 or more.

If the mass ratio (B)/(a) is less than 0.15, the hydrolysis of the component (a) by the component (B) is insufficient, and a rapid biodegradation rate cannot be obtained.

If the mass ratio (B)/(a) is too high, hydrolysis of the component (a) may occur even under normal circumstances (for example, before the component (a) is added to a compost container, before the component (a) is added to sea water, or the like), and the durability of the resin molded article during use may be lowered. Therefore, the mass ratio (B)/(a) is preferably 0.80 or less from the viewpoint of suppressing the biodegradation rate from being excessively fast.

The mass ratio (B)/(a) is preferably 0.15 to 0.80, more preferably 0.20 to 0.50, from the viewpoint of durability of the resin molded article in use and improvement of biodegradation rate.

Here, the component (a) and the component (B) may be contained as main components in order to improve the biodegradation rate.

Here, the component (a) and the component (B) being the main components means that the total amount of the component (a) and the component (B) is the largest in the entire resin composition.

Specifically, the total amount of the component (a) and the component (B) is 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, 95 mass% or more, or 100 mass% with respect to the entire resin composition.

[ other ingredients ]

The resin composition of the present embodiment may contain other components.

Examples of the other components include plasticizers, flame retardants, compatibilizers, releasing agents, light stabilizers, weather stabilizers, colorants, pigments, modifiers, anti-dripping agents, antistatic agents, hydrolysis inhibitors, fillers, reinforcing agents (glass fibers, carbon fibers, talc, clay, mica, glass flakes, ground glass, glass beads, crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, etc.), acid acceptors for preventing acetic acid release (oxides such as magnesium oxide and alumina, metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide, hydrotalcite, etc., calcium carbonate, talc, etc.), reactive trapping agents (for example, epoxy compounds, acid anhydride compounds, carbodiimide, etc.), and the like.

The content of other components is preferably 0 mass% or more and 5 mass% or less, respectively, with respect to the total amount of the resin composition. Here, "0 mass%" means that the resin composition does not contain other components.

Examples of the plasticizer include ester compounds, camphor, metal soaps, polyols, polyalkylene oxides, and the like. The plasticizer is preferably an ester compound in view of impact resistance of the resin molded product. The plasticizer may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the ester compound contained as the plasticizer in the resin composition of the present embodiment include adipate ester, citrate ester, sebacate ester, azelate ester, phthalate ester, acetate ester, dibasic acid ester, phosphate ester, condensed phosphate ester, ethylene glycol ester (e.g., ethylene benzoate), modified product of fatty acid ester (e.g., epoxidized fatty acid ester), and the like. Examples of the ester include monoesters, diesters, triesters, and polyesters. Among them, dicarboxylic acid diesters (adipic acid diester, sebacic acid diester, azelaic acid diester, phthalic acid diester, etc.) are preferable.

As the plasticizer, adipic acid ester is preferable. Adipic acid ester has high affinity with cellulose acylate (a), and is dispersed in cellulose acylate (a) in a nearly uniform state, whereby the thermal fluidity is further improved as compared with other plasticizers.

As the adipate ester, a mixture of the adipate ester and a component other than the adipate ester can be used. Examples of commercially available products of the mixture include daicatty 101 manufactured by Daihuachikushi chemical industry.

Examples of the fatty acid ester such as citrate, sebacate, azelate, phthalate, and acetate include esters of fatty acids and alcohols. Examples of the alcohol include: monohydric alcohols such as methanol, ethanol, propanol, butanol, and 2-ethylhexanol; polyhydric alcohols such as glycerin, polyglycerin (e.g., diglycerin), pentaerythritol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, trimethylolpropane, trimethylolethane, and sugar alcohols; and so on.

Examples of the glycol in the ethylene benzoate include ethylene glycol, diethylene glycol, and propylene glycol.

The epoxidized fatty acid ester is an ester compound having a structure in which a carbon-carbon unsaturated bond of an unsaturated fatty acid ester is epoxidized (i.e., oxetane). Examples of the epoxidized fatty acid ester include esters of fatty acids and alcohols in which a part or all of carbon-carbon unsaturated bonds in unsaturated fatty acids (for example, oleic acid, palmitoleic acid, vaccenic acid, linoleic acid, linolenic acid, nervonic acid, and the like) are epoxidized. Examples of the alcohol include: monohydric alcohols such as methanol, ethanol, propanol, butanol, and 2-ethylhexanol; polyhydric alcohols such as glycerin, polyglycerin (e.g., diglycerin), pentaerythritol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, trimethylolpropane, trimethylolethane, and sugar alcohols; and so on.

The molecular weight (or weight average molecular weight) of the ester compound contained as the plasticizer in the resin composition of the present embodiment is preferably 200 to 2000, more preferably 250 to 1500, and still more preferably 280 to 1000. Unless otherwise specified, the weight average molecular weight of the ester compound is a value measured according to the method for measuring the weight average molecular weight of the cellulose acylate (a).

The resin composition of the present embodiment may contain other resins than the component (a), the component (B), the component (C), and the component (D). When other resin is contained, the content of the other resin may be 5% by mass or less, preferably less than 1% by mass, based on the total amount of the resin composition. The resin composition more preferably contains no other resin (i.e., 0 mass%).

Examples of the other resin include conventionally known thermoplastic resins, and specifically include: a polycarbonate resin; a polypropylene resin; a polyester resin; a polyolefin resin; a polyester carbonate resin; a polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; polyether sulfone resin; a polyarylene resin; a polyetherimide resin; a polyacetal resin; a polyvinyl acetal resin; a polyketone resin; a polyetherketone resin; polyether ether ketone resin; a polyaryl ketone resin; a polyether nitrile resin; a liquid crystal resin; a polybenzimidazole resin; a polyoxamide resin; a vinyl polymer or copolymer obtained by polymerizing or copolymerizing 1 or more vinyl monomers selected from the group consisting of an aromatic alkenyl compound, a methacrylate ester, an acrylate ester and a vinyl cyanide compound; a diene-aromatic alkenyl compound copolymer; vinyl cyanide-diene-aromatic alkenyl compound copolymers; aromatic alkenyl compound-diene-vinyl cyanide-N-phenyl maleimide copolymer; vinyl cyanide- (ethylene-diene-propylene (EPDM)) -aromatic alkenyl compound copolymers; vinyl chloride resin; chlorinated vinyl chloride resin; and so on. These resins may be used alone or in combination of two or more.

[ Properties of resin composition ]

In the resin composition of the present embodiment, the solubility of the resin composition in methyl ethyl ketone at a liquid temperature of 25 ℃ is 200mg/ml or more.

When the solubility of the resin composition is 200mg/ml or more, the accelerating action of the epoxy group or hydroxyl group of the aromatic compound (B) on the hydrolysis of the component (a) increases, and the biodegradation rate of the obtained resin molded product becomes high.

The solubility of the resin composition is preferably 250mg/ml or more, more preferably 300mg/ml or more.

The solubility of the resin composition was measured as follows.

100ml of methyl ethyl ketone having a liquid temperature of 25 ℃ was mixed with 50000mg of a resin composition to be measured in a vessel, followed by applying ultrasonic waves having an oscillation frequency of 38kHz for 480 minutes and then standing for 3 hours.

Subsequently, the solution in the vessel was filtered through a filter having a mesh of 25 μm, and the dry mass of the residue on the filter was measured.

Then, the following formula: the solubility was calculated as (mass of resin composition dissolved in 100ml of methyl ethyl ketone)/(amount of methyl ethyl ketone 100 ml).

[ method for producing resin composition ]

Examples of the method for producing the resin composition of the present embodiment include: a method of mixing at least one of the component (a), the component (B), the component (C) and the component (D) with other components as necessary to melt-knead; a method in which at least one of the component (a), the component (B), the component (C), and the component (D) and, if necessary, other components are dissolved in a solvent; and so on. The means for melt-kneading is not particularly limited, and examples thereof include a twin-screw extruder, a henschel mixer, a banbury mixer, a single-screw extruder, a multi-screw extruder, and a worm kneader.

< resin molded article >

The resin molded article of the present embodiment includes the resin composition of the present embodiment. That is, the resin molded body of the present embodiment is composed of the same composition as the resin composition of the present embodiment.

In plastic waste, granular materials called microbeads (for example, granular materials having a particle size of 1000 μm or less) are likely to flow into the environment such as the sea through various filters, and are required to have higher biodegradability than resin molded articles such as shopping bags and straws.

Therefore, the resin molded body having rapid biodegradability of the present embodiment may be in a desired shape, but is preferably a granular body (hereinafter also referred to as "resin particle").

The volume average particle diameter of the granular bodies is preferably 3 μm to 100 μm, more preferably 5 μm to 70 μm, and still more preferably 8 μm to 60 μm.

When the particle size of the granular material is 3 μm or more, the number of particles per unit weight is not excessive, and thus the degradation rate of the biodegradation can be suppressed. On the other hand, when the particle size of the granules is 100 μm or less, the specific surface area is increased, and the biodegradation rate can be further increased.

Therefore, the volume average particle diameter of the granular material is preferably in the above range.

The large diameter side particle size distribution index GSDv of the granules is preferably 1.5 or less, more preferably 1.3 or less, and further preferably 1.2 or less.

When the particle size distribution of the granules is nearly uniform, regular hydrolysis is performed by giving a certain chance of contacting water, and the biodegradation rate can be further improved.

The volume average particle diameter and the large-diameter-side particle size distribution index GSDv of the granules were measured as follows.

The particle size was measured by an LS particle size distribution measuring apparatus "Beckman Coulter LS13320 (manufactured by Beckman Coulter corporation)", the cumulative distribution of the particle size was plotted from the small diameter side on the volume basis, and the particle size at the cumulative 50% point was obtained as the volume average particle size.

On the other hand, a cumulative distribution of particle diameters is plotted from the smaller diameter side on a volume basis, and the particle diameter at the cumulative 50% point is defined as the number average particle diameter D50v, and the particle diameter at the cumulative 84% point is defined as the number particle diameter D84 v. The large diameter side particle size distribution index GSDv is represented by the formula GSDv ═ D84v/D50v^1/2And (4) calculating.

The following methods can be mentioned as examples of the method for producing the granular particles.

1) Kneading and pulverizing method comprising kneading each component, pulverizing the obtained kneaded product, and classifying to obtain granular material

2) Dry process for producing granular material by kneading and pulverizing granular material to obtain granular material

3) Agglomeration method comprising mixing particle dispersions of the above components, agglomerating the particles in the dispersion, and heating for fusion to obtain granules

4) Dissolving and suspending method comprising suspending an organic solvent in which each component is dissolved in an aqueous solvent and granulating a granular material containing each component

Among these, wet methods such as coagulation-agglomeration method and dissolution-suspension method are preferable from the viewpoint of obtaining a granular product having a volume average particle diameter and a large-diameter side particle size distribution index GSDv in the above-mentioned ranges.

The method of molding the resin molded article according to the present embodiment may be an injection molded article obtained by injection molding, because of high degree of freedom in shape.

The cylinder temperature at the time of injection molding the resin molded article of the present embodiment is, for example, 160 ℃ to 280 ℃, preferably 180 ℃ to 240 ℃. The mold temperature at the time of injection molding the resin molded article of the present embodiment is, for example, 40 ℃ to 90 ℃, and more preferably 40 ℃ to 60 ℃.

The injection molding of the resin molded body according to the present embodiment can be performed using a commercially available apparatus such as NEX500 manufactured by hitachi resin industries, NEX150 manufactured by hitachi resin industries, NEX7000 manufactured by hitachi resin industries, PNX40 manufactured by hitachi resin industries, SE50D manufactured by sumitomo machineries, and the like.

The resin molded article of the present embodiment may be a resin molded article obtained by another molding method. As other molding methods, for example, extrusion molding, blow molding, hot press molding, roll molding, coating molding, cast molding, dip molding, vacuum molding, transfer molding, and the like can be applied.

Examples of the applications of the resin molded article of the present embodiment include particulate bodies of cosmetic base materials, polishing agents, abrasives, polishing agents, display pads, materials for bead molding, light diffusing particles, resin reinforcing agents, refractive index control agents, biodegradation accelerators, fertilizers, water absorbing particles, and toner particles.

The resin molded article of the present embodiment can be suitably used for applications such as electronic and electrical equipment, office equipment, home electric appliances, automobile interior materials, toys, and containers. Specific applications of the resin molded article of the present embodiment include: a housing of an electric appliance or a home electric appliance; various components of electronic and electric equipment or home electric appliances; interior components of automobiles; assembling the block toy; a plastic mold kit; a storage case for CD-ROM or DVD; tableware; beverage bottles; a food pan; a packaging material; a film; slicing; and so on.

[ examples ]

The resin composition and the resin molded article according to the present embodiment will be described in more detail below with reference to examples. The materials, amounts, proportions, treatment processes and the like shown in the following examples can be appropriately modified within a range not departing from the gist of the present invention. Therefore, the resin composition and the resin molded article of the present embodiment should not be construed as being limited to the specific examples shown below.

< preparation of respective materials >

The following materials were prepared.

[ cellulose acylate (A) ]

CA 1: eastman chemical "CAP 482-20", cellulose acetate propionate, weight average degree of polymerization 716, degree of substitution of acetyl 0.18, degree of substitution of propionyl 2.49.

CA 2: eastman chemical "CAP 504-0.2", cellulose acetate propionate, weight average degree of polymerization 133, degree of substitution of acetyl 0.04, degree of substitution of propionyl 2.09.

CA 3: eastman chemical "CAB 171-15", cellulose acetate butyrate, weight average degree of polymerization 754, degree of substitution of acetyl 2.07, degree of substitution of butyryl 0.73.

CA 4: daicel "L50", diacetylcellulose, weight average degree of polymerization 570.

CA 5: daicel "LT-35", triacetyl cellulose, weight average degree of polymerization 385.

[ aromatic Compound (B) ]

PAC 1: cardolite 'NX-2503', hydroxyethylated cardanol, and having a molecular weight of 296-320

PAC 2: cardolite 'Ultra LITE 513', glycidyl ether of cardanol, and molecular weight of 354-361.

PAC 3: phenol novolac epoxy resin "EPICLON 865-alkyl modified product" available from DIC corporation

Examples 1 to 18 and comparative examples 1 to 3

(preparation of resin pellets RE 1-13)

Kneading was carried out by a twin-screw kneading apparatus (TEX 41SS, manufactured by Toshiba machine Co., Ltd.) while adjusting the barrel temperature in accordance with the charge ratio shown in Table 1, to prepare resin compositions RE1 to RE13 (hereinafter referred to as resin pellets RE1 to RE13) in pellet form.

(preparation of resin particles) -preparation of resin particles PC1

300g of the resin pellet (RE1) was completely dissolved in 700g of methyl ethyl ketone. This was added to an aqueous liquid (prepared by dispersing 100g of calcium carbonate, 4g of carboxymethyl cellulose, and 200g of methyl ethyl ketone in 1100g of pure water) and stirred for 3 hours. 10g of sodium hydroxide was added thereto, heated to 80 ℃ and stirred for 3 hours to remove methyl ethyl ketone. After the residue was filtered off, the solid was freeze-dried to obtain resin pellets PC 1.

Preparation of resin particles PC 2-18

Resin pellets PC2 to 18 were obtained in the same manner as resin pellet PC1 except that the amounts of the respective components (calcium carbonate amount, carboxymethyl cellulose amount, methyl ethyl ketone amount) in the resin pellets and the aqueous liquid, the stirring time of the aqueous liquid, and the amount of sodium hydroxide added were changed from table 2.

Preparation of the resin particles PC19, 20

Commercially available cellulose pellets, CELLULOBEADS D10 (manufactured by Dadonghua Co., Ltd.) were prepared as resin pellets PC19 and BELLOCEA (manufactured by Daicel Co., Ltd.) was prepared as resin pellets PC 20.

< measurement of particle size, particle size distribution, and solubility >

The volume average particle diameter and the particle size distribution GSDv of the resin particles were measured by the above method using a LS particle size distribution measuring apparatus Beckman Coulter LS13320 (manufactured by Beckmancoulter).

In addition, the solubility of the resin pellets as a raw material of the resin particles was measured in the above-described manner.

The results are shown in Table 2.

< measurement of biodegradability >

Using the obtained resin pellets, the aerobic biodegradation rate was measured by a method according to ISO-14855-2 (2018), the anaerobic biodegradation rate was measured by a method according to ISO-14853 (2016), and the time until 50% and 90% of the biodegradation rates were reached was evaluated as the biodegradation rate. The results are shown in Table 2.

From the above results, it is clear that the biodegradation rate of the resin particles of examples 1 to 18 is higher than that of the resin particles of comparative examples 1 to 3.

(example 19, comparative example 4)

Using the resin pellets RE1 (corresponding to examples) and RE11 (corresponding to comparative examples) shown in Table 1, test pieces having a thickness of 10mm × 12.5mm and a thickness of 4mm were injection-molded by an injection molding machine (NEX 500I, manufactured by Nilapinik resin industries, Ltd.) under conditions of an injection peak pressure of not more than 180MPa, a molding temperature of 190 ℃ and a mold temperature of 40 ℃.

Each test piece was subjected to biodegradability measurement. The results are shown in Table 4.

[ Table 4]

From the above results, it is understood that the injection molded article of example 19 has a higher biodegradation rate than the injection molded article of comparative example 4.