Composition for forming enzyme-containing particles, enzyme-containing particles, enzymatically decomposable resin composition, and molded article

Abstract

To provide a composition for forming enzyme-containing particles which enables simple and inexpensive formation of enzyme-containing particles, enzyme-containing particles having excellent hydrolyzability in the presence of water, a molded body which can achieve both excellent durability of a resin and excellent biodegradability, and an enzymatic decomposable resin composition which enables simple and inexpensive formation of the molded body.SOLUTION: A composition for forming enzyme-containing particles contains a modified polymer which enables formation of a polymer that has a polymerizable group and is hydrolyzable, an enzyme which does not decompose a polymer that is obtained by polymerization of the modified polymer and is hydrolyzable, and a polymerization initiator for polymerizing the modified polymer, where the modified polymer contains modified polycaprolactone having a polymerizable group.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a composition for forming an enzyme-containing particle, an enzyme-containing particle, an enzyme-decomposable resin composition, and a molded article. [Background technology]

[0002] In the 20th century, humans have chemically synthesized a variety of useful new synthetic polymer compounds. However, because these compounds have chemical structures that do not exist in nature, there are no microorganisms or enzymes that can decompose them. Therefore, when these compounds are released into the natural environment as waste, they never decompose, leading to environmental pollution problems caused by plastic waste, which are symbolized by the problem of marine plastic pollution.

[0003] One solution to this problem is the development of biodegradable plastics (biodegradable resins) that can be completely decomposed into carbon dioxide and water by the decomposition enzymes secreted by microorganisms present in the environment. Polylactic acid is one representative example of such biodegradable resins. However, general biodegradable resins tend to deteriorate during use and have durability issues. Furthermore, although polylactic acid is enzymatically degradable, its decomposition rate is extremely slow. To improve the decomposition rate of such biodegradable resins, several methods have been proposed, including blending a highly hydrolyzable polyester with polylactic acid as a degradation accelerator (see Non-Patent Document 1), and enzyme-encapsulated biodegradable resins with a decomposition start switch function that can decompose polylactic acid, which normally only decomposes in a compost environment, even in an aqueous environment (see Non-Patent Document 2).

[0004] However, the porous gel used in the enzyme-encapsulated biodegradable resin is BioGel P gel (an acrylamide-based gel), which is problematic in terms of biodegradability and also insufficient in terms of the decomposition initiation switch function that initiates biodegradation when the resin is released into the environment.

[0005] Therefore, a biodegradable resin that can achieve both excellent resin durability and excellent biodegradability has not yet been provided, and there is currently a strong demand for such a resin. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] (F) Katayama, Denki, Yoshikawa, Masashi, Kogure, Masato, "High-speed enzymatic decomposition of biomass plastics for resource recycling," Toyo Seikan Group Research Institute [Non-patent document 2] QiuYuan Huang, et al., Biomacromolecules, 2020, 21(8), p.3301-3307. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to solve the above-mentioned problems of the prior art and to achieve the following objects: That is, the present invention aims to provide an enzyme-containing particle-forming composition that can easily and inexpensively form enzyme-containing particles, enzyme-containing particles that have excellent hydrolysis properties in the presence of water, a molded article that can achieve both excellent resin durability and excellent biodegradability, and an enzyme-decomposable resin composition that can easily and inexpensively form the molded article. [Means for solving the problem]

[0008] The means for solving the above problems are as follows: <1> The composition comprises a modified polymer having a polymerizable group and capable of forming a hydrolyzable polymer, an enzyme that does not decompose the hydrolyzable polymer formed by polymerization of the modified polymer, and a polymerization initiator that polymerizes the modified polymer, The composition for forming an enzyme-containing particle is characterized in that the modified polymer contains a modified polycaprolactone having a polymerizable group. <2> The aforementioned <1> The enzyme-containing particle is characterized by being obtained by curing the enzyme-containing particle-forming composition described in 1. <3> The aforementioned <2> and a resin that can be decomposed by the enzyme contained in the enzyme-containing particle. <4> The aforementioned <3> The present invention relates to a molded article obtained by curing the enzyme-decomposable resin composition described above. [Effects of the Invention]

[0009] According to the present invention, the above-mentioned problems of the prior art can be solved, the above-mentioned object can be achieved, and a composition for forming enzyme-containing particles that can form enzyme-containing particles simply and inexpensively, enzyme-containing particles that have excellent hydrolysis properties in the presence of water, a molded body that can combine excellent resin durability with excellent biodegradability, and an enzyme-decomposable resin composition that can form the molded body simply and inexpensively can be provided. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1A is a schematic explanatory view showing an example of an enzyme-containing particle of the present invention. [Figure 1B] FIG. 1B is a schematic explanatory view showing another example of the enzyme-containing particle of the present invention. [Figure 2] FIG. 2 is a schematic explanatory view showing an example of the molded article of the present invention. [Figure 3] FIG. 3 is a schematic explanatory diagram showing an example of the biodegradation scheme of the molded article of the present invention. [Figure 4] 4 is an electron microscope image of the spherical white powder [enzyme-containing particle 1] obtained in Production Example 1-1 (scale bar: 5 μm). [Figure 5] FIG. 5 is a graph showing the results of the enzymatic decomposition test in Test Example 4-2. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Composition for forming enzyme-containing particles) The composition for forming enzyme-containing particles of the present invention contains a modified polymer that has a polymerizable group and is capable of forming a hydrolyzable polymer, an enzyme that does not decompose the hydrolyzable polymer formed by polymerization of the modified polymer, and a polymerization initiator that polymerizes the modified polymer, and further contains other components as necessary. The enzyme-containing particle-forming composition is used to form the enzyme-containing particles of the present invention, which have excellent hydrolysis properties in the presence of water.

[0012] As used herein, the terms "polymer" and "monomer" refer to any basic unit adapted to form a solid material by polymerization, either alone or in combination with other monomers or polymers. "Polymer" also includes "oligomers."

[0013] As used herein, "biodegradable" refers to the ability to be decomposed by enzymes widely present in nature. More specifically, "biodegradable" means that when a substance is reacted with an enzyme or contacted with a microorganism at 37°C and atmospheric pressure for 4 days, the mass of the substance changes from the mass before the reaction or contact with a microorganism, and the rate of change is greater than that of a substance without the addition of the enzyme or microorganism.

[0014] <Modified polymer> The modified polymer having a polymerizable group and capable of forming a hydrolyzable polymer includes a modified polycaprolactone having a polymerizable group, and may further include other modified polymers as required.

[0015] As used herein, the term "hydrolyzable polymer" refers to a polymer that can be decomposed by reacting the polymer with water to give decomposition products.

[0016] The polymerizable group is not particularly limited and can be appropriately selected depending on the purpose. Examples include ring-opening polymerizable groups such as vinyl groups, allyl groups, propenyl groups, vinylidene groups, vinylene groups, (meth)acrylic groups, (meth)acryloyl groups, vinyl ether groups, vinylbenzyl ether groups, (meth)acryloxy groups, (meth)allylamido groups, styryloxy groups, styrylamide groups, isocyanate groups, thioisocyanate groups, carboxyl groups, alcoholic or phenolic hydroxyl groups, silanol groups, alicyclic epoxy groups, epoxy groups, glycidyl groups, and cyclic ether groups such as oxetane groups. The modified polymer may have only one of these groups or two or more of these groups. The modified polymer may also have only one type of these groups or two or more types. Among these, the modified polymer preferably has a (meth)acryloyl group, as this results in excellent hydrolysis and biodegradability of the enzyme-containing particles that are cured.

[0017] In this specification, the term "(meth)acryloyl" means both acryloyl and methacryloyl, the term "(meth)acrylic" means both acrylic and methacrylic, the term "(meth)acryloxy" means both acryloxy and methacryloxy, and the term "(meth)allylamide" means both allylamide and methallylamide.

[0018] <<Modified polycaprolactone with polymerizable groups>> The modified polycaprolactone having a polymerizable group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include modified polycaprolactone diols having a polymerizable group, modified polycaprolactone triols having a polymerizable group, modified polycaprolactone tetraols having a polymerizable group, etc. These may be used alone or in combination of two or more.

[0019] The polymerizable group in the modified polycaprolactone having a polymerizable group is the same as that described above.

[0020] The proportion (%) of polymerizable groups in the modified polycaprolactone having polymerizable groups is preferably 10% to 90% and more preferably 30% to 70% relative to the polycaprolactone polyol before the polymerizable groups are introduced. If the proportion of polymerizable groups is less than 10%, the crosslink density may be low and the durability of the resin may be insufficient, while if it exceeds 90%, the crosslink density may be high, the viscosity may increase, and enzymatic decomposition may be insufficient.

[0021] The content (%) of the polymerizable group in the modified polycaprolactone having the polymerizable group can be determined by the following method. The following describes an example of an acroyl-modified polycaprolactone in which the polymerizable group is an acroyl group. First, the polycaprolactone polyol used to prepare the sample to be measured before the introduction of the acroyl group was measured using a Fourier transform infrared spectrophotometer (FT-IR, device name: Nicolet iS20, manufactured by Thermo). -1 ~1,653cm -1 The peak intensity of (H2C=CH-C(=O)-) is measured at the acroyl group of the compound. The measurement result is taken as peak intensity α. Next, the sample to be measured (acroyl-modified polycaprolactone) was measured using a Fourier transform infrared spectrophotometer (FT-IR, device name: Nicolet iS20, manufactured by Thermo) at 1,605 cm -1 ~1,653cm -1 The peak intensity of (H2C=CH-C(=O)-) is measured at the acroyl group of the compound. The measurement result is taken as peak intensity X. The abundance (%) of the acroyl groups in the acroyl-modified polycaprolactone can be calculated by the following formula 1 using the measured peak intensities. Presence rate (%) of acroyl groups in acroyl-modified polycaprolactone = {(Peak intensity X) / (Peak intensity α)} × 100 Formula 1 The abundance (%) of the polymerizable groups contained in the modified polycaprolactone having the polymerizable groups can be measured by changing the range of peak intensity to be measured depending on the type of the polymerizable groups.

[0022] -Method for producing modified polycaprolactone having polymerizable groups- The method for producing the modified polycaprolactone having the polymerizable group is not particularly limited, and can be appropriately selected from known methods depending on the type of the polymerizable group. For example, a method for producing a (meth)acrylic-modified polycaprolactone includes reacting a polycaprolactone polyol with an acylating agent in a solvent.

[0023] --Polycaprolactone polyol-- The polycaprolactone polyol may be an appropriately synthesized product or a commercially available product.

[0024] The method for obtaining the polycaprolactone polyol by synthesis is not particularly limited and can be appropriately selected from known methods. For example, there is a method of reacting caprolactone (monomer) with a polymerization initiator in a solvent.

[0025] The caprolactone used as a raw material for synthesizing the polycaprolactone polyol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include monofunctional caprolactone diol, bifunctional caprolactone diol, trifunctional caprolactone diol, tetrafunctional caprolactone diol, monofunctional caprolactone triol, bifunctional caprolactone triol, trifunctional caprolactone triol, tetrafunctional caprolactone triol, monofunctional caprolactone tetraol, bifunctional caprolactone tetraol, trifunctional caprolactone tetraol, tetrafunctional caprolactone tetraol, etc. These may be used alone or in combination of two or more. Among these, bifunctional caprolactone diol, trifunctional caprolactone diol, tetrafunctional caprolactone diol, monofunctional caprolactone triol, bifunctional caprolactone triol, trifunctional caprolactone triol, tetrafunctional caprolactone triol, monofunctional caprolactone tetraol, bifunctional caprolactone tetraol, and trifunctional caprolactone tetraol are preferred. Monofunctional polycaprolactone monool is not incorporated into the polycaprolactone skeleton, so polycaprolactone cannot be formed. On the other hand, tetrafunctional caprolactone tetraol increases the crosslink density, which may increase the viscosity and reduce enzymatic decomposition properties.

[0026] The polymerization initiator used in the synthesis of the polycaprolactone polyol is not particularly limited and can be appropriately selected depending on the purpose, and the same initiators as those described in the <Polymerization initiator> section below can be used.

[0027] The solvent used in the synthesis of the polycaprolactone polyol is not particularly limited and can be appropriately selected depending on the purpose, and the same solvents as those described in the section "Solvent" below can be used.

[0028] Commercially available polycaprolactone polyols include, for example, the PCL series (manufactured by Daicel Corporation) such as Placcel (PCL) 410 (polycaprolactone tetraol, weight average molecular weight (Mw): 1,000), PCL 210 (polycaprolactone diol, weight average molecular weight (Mw): 1,000), PCL 312 (polycaprolactone triol, weight average molecular weight (Mw): 1,250), and PCL 308 (polycaprolactone tetraol, weight average molecular weight (Mw): 850); and the Capa series (manufactured by Ingevity) such as Capa 2100 (polycaprolactone diol, weight average molecular weight (Mw): 1,000), Capa 3091 (polycaprolactone triol, weight average molecular weight (Mw): 900), and Capa 4101 (polycaprolactone tetraol, weight average molecular weight (Mw): 1,000). These may be used alone or in combination of two or more.

[0029] The weight-average molecular weight (Mw) of the polycaprolactone polyol is not particularly limited and can be selected appropriately depending on the purpose, but the lower limit is preferably 300 or more, more preferably 1,000 or more. The upper limit of the weight-average molecular weight (Mw) of the polycaprolactone polyol is also not particularly limited and can be selected appropriately depending on the purpose, but is preferably 3,000 or less. If the weight-average molecular weight (Mw) of the polycaprolactone polyol is less than 300, the properties derived from the caprolactone skeleton may not be obtained. If the weight-average molecular weight (Mw) of the polycaprolactone polyol is more than 3,000, the crosslinked structure may be insufficient. The weight average molecular weight (Mw) can be measured, for example, by Shodex (registered trademark) GPC-101 (a product of Showa Denko KK).

[0030] --Acylating agent-- The acylating agent is not particularly limited and can be appropriately selected from known agents, for example, fatty acid anhydrides, acid halides, etc. These may be used alone or in combination of two or more. Examples of the fatty acid anhydride include (meth)acrylic anhydride, α-trifluoromethyl(meth)acrylic anhydride, (meth)acrylic acid trifluoroacetic acid mixed acid anhydride, α-trifluoromethyl(meth)acrylic acid trifluoroacetic acid mixed acid anhydride, (meth)acrylic acid p-nitrobenzoic acid mixed acid anhydride, and (meth)acrylic acid ethyl carbonic acid mixed acid anhydride. Examples of the acid halide include (meth)acrylic acid chloride, (meth)acrylic acid bromide, and α-trifluoromethylacrylic acid chloride.

[0031] --solvent-- The solvent is not particularly limited and can be appropriately selected depending on the type of the acylating agent, and examples thereof include chlorine-based solvents such as methylene chloride, chloroform, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; ethers such as dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; nitriles such as acetonitrile; ketones such as acetone and 2-butanone; esters such as ethyl acetate and n-butyl acetate; and aprotic polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide, and N-methyl-2-pyrrolidone. These solvents may be used alone or in combination of two or more.

[0032] The content of the modified polycaprolactone having a polymerizable group in the composition for forming an enzyme-containing particle is not particularly limited and can be appropriately selected depending on the purpose.

[0033] <<Other modified polymers>> The other modified polymer is a modified polymer other than the modified polycaprolactone having a polymerizable group, which has the polymerizable group and can form a hydrolyzable polymer. Such other modified polymers are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected depending on the purpose, and examples include modified PLA (polylactic acid), modified PGA (polyglycolic acid), modified PHBH (copolyester of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid), modified PBS (polybutylene succinate), modified PVA (polyvinyl alcohol), etc. These may be used alone or in combination of two or more.

[0034] The content of the other polymer in the composition for forming an enzyme-containing particle is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose.

[0035] <Enzyme> The enzyme that does not decompose the hydrolyzable polymer formed by polymerization of the modified polymer is not particularly limited and can be appropriately selected depending on the type of the modified polymer, and examples thereof include lipase, proteinase, cutinase, etc. These may be used alone or in combination of two or more. Among these, an enzyme that does not decompose the cured product of the modified polycaprolactone having a polymerizable group is preferred, and proteinase is particularly preferred.

[0036] As used herein, "an enzyme that does not decompose a polymer" means an enzyme that decomposes the hydrolyzable polymer at a rate of 0%, i.e., an enzyme that does not decompose at all the hydrolyzable polymer formed by polymerization of the modified polymer.

[0037] The decomposition rate of the polymer can be determined by the following method. First, the mass of the polymer to be measured (hereinafter sometimes referred to as "initial mass") is measured. Next, the polymer to be measured is placed in a glass container, and an enzyme solution is added so that the enzyme is 0.1 U to 100 U per 1 mg of the polymer.The polymer to be measured is completely immersed in the enzyme solution, sealed, and left at 37°C for 4 days. Next, undecomposed polymer fragments are removed by filtration, dried under reduced pressure at 40° C. for 12 hours, and the mass (hereinafter sometimes referred to as "mass after enzyme treatment") is measured. The decomposition rate can be calculated from the initial mass and the mass after the enzyme treatment using the following formula 2. Decomposition rate (%) = (initial mass - mass after enzyme treatment) / initial mass × 100 Equation 2

[0038] The content of the enzyme in the composition for forming an enzyme-containing particle is not particularly limited and can be appropriately selected depending on the purpose.

[0039] In the enzyme-containing particle-forming composition, the content of the enzyme relative to 100 parts by mass of the modified polycaprolactone having a polymerizable group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass. In the enzyme-containing particle-forming composition, if the content of the enzyme relative to 100 parts by mass of the modified polycaprolactone having a polymerizable group is less than 0.01 part by mass, biodegradability may be insufficient, and if it exceeds 5 parts by mass, the enzyme may be exposed and diffused on the surface of the enzyme-containing particle, which is the cured product of the enzyme-containing particle-forming composition, resulting in insufficient durability of the resin.

[0040] <Polymerization initiator> The polymerization initiator for polymerizing the modified polymer is not particularly limited and can be appropriately selected depending on the type of the modified polymer, and examples thereof include thermal polymerization initiators, photopolymerization initiators, etc. These may be used alone or in combination of two or more.

[0041] -Thermal polymerization initiator- Examples of the thermal polymerization initiator include azo-based initiators, peroxide initiators, persulfate initiators, redox (oxidation-reduction) initiators, etc. These may be used alone or in combination of two or more.

[0042] Commercially available azo initiators can be used, and examples of such commercially available products include VA-044, VA-46B, V-50, VA-057, VA-061, VA-067, VA-086, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2'-azobis(2-amidinopropane) dihydrochloride (VAZO 50), 2,2'-azobis(2,4-dimethylvaleronitrile) (VAZO 52), 2,2'-azobis(isobutyronitrile) (VAZO 64), 2,2'-azobis-2-methylbutyronitrile (VAZO 67), and 1,1-azobis(1-cyclohexanecarbonitrile) (VAZO 88) (all manufactured by DuPont). Examples include 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(methyl isobutylate) (V-601) (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "VAZO" is a trademark).

[0043] Examples of peroxide initiators include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate (Perkadox 16S) (manufactured by Akzo Nobel, where "Perkadox" is a trademark), di(2-ethylhexyl)peroxydicarbonate, t-butyl peroxypivalate (Lupersol 11) (manufactured by Elf Atochem, where "Lupersol" is a trademark), t-butyl peroxy-2-ethylhexanoate (Trigonox 21-C50) (manufactured by Akzo Nobel, where "Trigonox" is a trademark), and dicumyl peroxide.

[0044] Examples of persulfate initiators include potassium persulfate, sodium persulfate, and ammonium persulfate. Redox (oxidation-reduction) initiators include, for example, combinations of persulfate initiators with reducing agents such as sodium metabisulfite and sodium bisulfite, systems based on organic peroxides and tertiary amines, e.g., systems based on benzoyl peroxide and dimethylaniline, systems based on organic hydroperoxides and transition metals, and systems based on cumene hydroperoxide and cobalt naphthate.

[0045] -Photopolymerization initiator- Examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-dichlorobenzophenone, p,p-bisdiethylaminobenzophenone, Michler's ketone, benzil, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-propyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl methyl ketal, thioxanthone, 2-chlorothioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropan-1-one, methylbenzoyl formate, 1-hydroxycyclohexyl phenyl ketone, azobisisobutyronitrile, benzoyl peroxide, and di-tert-butyl peroxide. These may be used alone or in combination of two or more.

[0046] Among these, as the polymerization initiator, a radical polymerization initiator is preferred from the viewpoint of being able to react with various materials and to polymerize freely, a polymerization initiator containing a peroxide as a main component is more preferred, and a polymerization initiator containing a peroxydicarbonate as a main component is particularly preferred from the viewpoint of being active at low temperatures.

[0047] The content of the polymerization initiator in the composition for forming an enzyme-containing particle is not particularly limited as long as it can polymerize the modified polymer, and can be appropriately selected depending on the purpose.

[0048] <Other ingredients> The other components in the composition for forming an enzyme-containing particle are not particularly limited and can be selected appropriately for the purpose as long as they do not impair the effects of the present invention, and examples thereof include polymers other than the modified polymers, monomers, oligomers, etc. These may be used alone or in combination of two or more.

[0049] The content of the other components in the composition for forming an enzyme-containing particle is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose.

[0050] The enzyme-containing particle-forming composition can be cured to form enzyme-containing particles simply and inexpensively, and is therefore suitable for use in the production of the enzyme-containing particles of the present invention, which will be described later.

[0051] (enzyme-containing particles) The enzyme-containing particle of the present invention is produced by curing the enzyme-containing particle-forming composition of the present invention, and therefore contains a hydrolyzable polymer formed by polymerization of the modified polymer in the enzyme-containing particle-forming composition, an enzyme that does not decompose the hydrolyzable polymer, and, if necessary, other components.

[0052] The enzyme-containing particles are formed by immobilizing the enzyme on the hydrolyzable polymer. This allows the enzyme's enzymatic activity to withstand external stimuli such as heat and UV radiation, resulting in excellent durability. Meanwhile, since the polymer that immobilizes the enzyme is hydrolyzable, decomposition of the polymer begins in the presence of water, thereby exposing and diffusing the enzyme immobilized on the polymer. Therefore, by incorporating the enzyme-containing particles into a molded product obtained by curing the enzyme-degradable resin, the molded product will not decompose during use, but will only begin to biodegrade when exposed to water in the environment. Therefore, the enzyme-containing particles can impart a decomposition start switch function to the molded product.

[0053] The structure and shape of the enzyme-containing particles are not particularly limited and can be selected appropriately depending on the purpose, but it is preferable that the enzyme that does not decompose the hydrolyzable polymer is encapsulated (sometimes referred to as "encapsulated") in a hydrolyzable polymer formed by polymerizing the modified polymer.

[0054] <Other ingredients> The other components in the enzyme-containing particles are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected depending on the purpose. Examples include surfactants (emulsifiers), dispersants, antifoaming agents, and adhesion enhancers. These may be used alone or in combination of two or more. Among these, it is preferable that the enzyme-containing particles contain a surfactant, as this can increase the durability of the enzyme-containing particles and impart an excellent decomposition initiation switch function to the molded article.

[0055] -Surfactants- The surfactant is not particularly limited and can be appropriately selected depending on the type of the modified polymer, and examples thereof include cationic surfactants, anionic surfactants, and nonionic surfactants. These surfactants may be used alone or in combination of two or more. Among these, nonionic surfactants are preferred from the viewpoint of ionic impurities. Examples of the nonionic surfactant include ethylene glycol, polyvinyl alcohol (PVA), water-soluble cellulose, ethylene oxide surfactants (polyoxyethylene (POE) alkyl ether, polyoxyethylene (POE) alkyl allyl ether, polyoxyethylene polyoxypropylene glycol, etc.), polyhydric alcohol fatty acid ester surfactants (glycerin fatty acid ester, anhydrosorbitol fatty acid ester, etc.), poly(ethyleneimine) surfactants, etc. Among these, polyvinyl alcohol (PVA) and water-soluble cellulose are preferred.

[0056] The content of the surfactant in the enzyme-containing particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1% by mass to 10% by mass, more preferably 1% by mass to 3% by mass. If the content of the surfactant is less than 0.1% by mass, emulsification may not proceed sufficiently, making it impossible to form the enzyme-containing particles. If the content of the surfactant is more than 10% by mass, the properties of the surfactant may have an adverse effect on the resin (for example, the biodegradation of a molded product obtained by curing the enzyme-degradable resin may be slowed, or the desired properties of the hydrolyzable polymer may not be obtained).

[0057] In the enzyme-containing particle forming composition, the content of the surfactant relative to 100 parts by mass of the modified polycaprolactone having a polymerizable group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 3 parts by mass or less. In the enzyme-containing particle forming composition, if the content of the surfactant relative to 100 parts by mass of the modified polycaprolactone having a polymerizable group is less than 0.1 parts by mass, the durability of the enzyme-containing particle may be insufficient, or when the enzyme-containing particle is contained in a molded body obtained by curing the enzyme-decomposable resin, the molded body may be decomposed, resulting in insufficient durability of the molded body. If the content exceeds 10 parts by mass, the properties of the surfactant may have an adverse effect on the resin.

[0058] -Dispersant- The dispersant is not particularly limited and can be appropriately selected depending on the purpose. For example, an amino group-containing compound such as polyvinylpyrrolidone (PVP) or polyethyleneimine can be used. Other examples of the dispersant that can be used include compounds having functional groups such as sulfo groups (including sulfonates), sulfonyl groups, sulfonamide groups, carboxylic acid groups (including carboxylates), amide groups, phosphoric acid groups (including phosphates and phosphoric acid esters), phosphino groups, silanol groups, epoxy groups, isocyanate groups, cyano groups, vinyl groups, thiol groups, and carbinol groups. These compounds may be used alone or in combination of two or more.

[0059] The content of the dispersant in the enzyme-containing particles is not particularly limited and can be appropriately selected depending on the purpose.

[0060] -Antifoaming agent- The antifoaming agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include higher alcohols, higher alcohol derivatives, fatty acid derivatives, etc. These may be used alone or in combination of two or more.

[0061] The content of the antifoaming agent in the enzyme-containing particles is not particularly limited and can be appropriately selected depending on the purpose.

[0062] -Adhesion enhancer- The adhesion enhancer is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include silane coupling agents having a reactive functional group such as a carboxyl group, a (meth)acryloyl group, a vinyl group, an isocyanate group, an epoxy group, or a mercapto group. Specific examples of the adhesion enhancer include trimethoxysilylbenzoic acid, 3-((meth)acryloyloxy)propyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, (3-isocyanatopropyl)triethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These may be used alone or in combination of two or more.

[0063] The content of the adhesion enhancer in the enzyme-containing particles is not particularly limited and can be appropriately selected depending on the purpose.

[0064] The method for producing the enzyme-containing particles is not particularly limited as long as it is a method that can harden the enzyme-containing particle-forming composition without inactivating the enzyme, and can be appropriately selected depending on the type of polymerization initiator, etc. Examples include a method of hardening the enzyme-containing particle-forming composition with heat, a method of hardening the enzyme-containing particle-forming composition with light, etc.

[0065] The temperature for the thermal curing is not particularly limited as long as it is a temperature at which the enzyme-containing particle-forming composition can be cured without inactivating the enzyme, and can be appropriately selected depending on the type of polymerization initiator, etc.

[0066] The light conditions for curing with light are not particularly limited as long as they are light conditions that can cure the enzyme-containing particle-forming composition without inactivating the enzyme, and can be selected appropriately depending on the type of polymerization initiator, etc.

[0067] The method for encapsulating the enzyme that does not decompose the hydrolyzable polymer in the hydrolyzable polymer obtained by polymerizing the modified polymer is not particularly limited, and can be appropriately selected from known methods depending on the type of polymerizable group possessed by the modified polymer, etc., but from the viewpoint of ease of production, the interfacial polymerization method is preferred.

[0068] The surfactant may be added during the curing reaction of the enzyme-containing particle-forming composition or after the curing reaction of the enzyme-containing particle-forming composition. Among these, adding the surfactant during the curing reaction of the enzyme-containing particle-forming composition is preferred because the surfactant can be distributed (coated) on the surfaces of the enzyme-containing particles, allowing for simple and efficient production.

[0069] An example of the enzyme-containing particle will be described below with reference to FIG. 1A. The enzyme-containing particle 1 has a structure as shown in FIG. 1A, and is composed of an enzyme 3 encapsulated inside a hydrolyzable polymer 2 formed by polymerizing a modified polymer.

[0070] Next, another example of the enzyme-containing particle will be described with reference to FIG. 1B. The enzyme-containing particle 1 has a structure as shown in Fig. 1B, in which a hydrolyzable polymer 2 formed by polymerization of a modified polymer is used as a core particle, and as in the case of Fig. 1A, the core particle encapsulates an enzyme 3 that does not decompose the hydrolyzable polymer 2 formed by polymerization of a modified polymer. The outermost surface of the core particle has a capsule structure with a shell layer 4 made of a surfactant.

[0071] The coverage of the core particles with the surfactant is not particularly limited and can be selected appropriately depending on the type of modified polymer, with the lower limit being preferably 60% or more, more preferably 80% or more. If the coverage is less than 60%, the durability of the enzyme-containing particles may be insufficient, and when the enzyme-containing particles are incorporated into a molded product obtained by curing the enzyme-degradable resin, the molded product may be decomposed, resulting in insufficient durability of the molded product. The upper limit of the coverage is not particularly limited in terms of biodegradability and durability, but is preferably 95% or less, more preferably 90% or less, from the viewpoint of cost. The coverage can be determined by observing the surface of the enzyme-containing particles with a scanning electron microscope (SEM) (for example, JSM-6510A, manufactured by JEOL Ltd.).

[0072] The enzyme-containing particles have excellent durability and do not lose their enzymatic activity due to external stimuli such as heat or UV irradiation, while also having excellent hydrolysis properties in the presence of water. Therefore, they are suitable for use in the molded article of the present invention described below, and can be suitably imparted with a decomposition start switch function that initiates biodegradation only when the molded article is exposed to water in the environment.

[0073] (Enzyme-degradable resin composition) The enzyme-decomposable resin composition of the present invention contains the enzyme-containing particle of the present invention and a resin that can be decomposed by the enzyme contained in the enzyme-containing particle, and further contains other components as necessary.

[0074] <Enzyme-containing particles> The enzyme-containing particles are the enzyme-containing particles of the present invention, and are as described in the above section (Enzyme-containing particles).

[0075] The content of the enzyme-containing particles in the enzymatically decomposable resin composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1% by mass to 30% by mass, more preferably 5% by mass to 15% by mass, relative to the total amount of the enzymatically decomposable resin composition. If the content of the enzyme-containing particles is less than 1% by mass, the biodegradability of the molded product, which is a cured product of the enzymatically decomposable resin composition, may be insufficient. If the content of the enzyme-containing particles is more than 30% by mass, the enzyme may be exposed and diffused on the surface of the molded product, which is a cured product of the enzymatically decomposable resin composition, resulting in insufficient durability of the resin.

[0076] <Resin> The enzyme-decomposable resin contained in the enzyme-containing particles is not particularly limited and can be appropriately selected depending on the type of enzyme, but a polymer having a polymerizable group is preferred, such as polylactic acid, polyglycolic acid, or a copolymer of polylactic acid and polycaprolactone having a polymerizable group. These may be used alone or in combination of two or more. Among these, polylactic acid having a polymerizable group is preferred.

[0077] Examples of the polymerizable group in the polylactic acid having a polymerizable group include the same as those described in the section <Modified polymer> of the above (Composition for forming enzyme-containing particles).

[0078] <<Polylactic acid with polymerizable groups>> The polylactic acid having a polymerizable group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include modified polylactic acid diol having a polymerizable group, modified polylactic acid triol having a polymerizable group, modified polylactic acid tetraol having a polymerizable group, etc. These may be used alone or in combination of two or more.

[0079] The proportion (%) of polymerizable groups in the modified polylactic acid having the polymerizable groups is preferably 10% to 90% and more preferably 30% to 70% relative to the polylactic acid polyol before the polymerizable groups are introduced. If the proportion of polymerizable groups is less than 10%, the crosslink density will be low and the durability of the resin may be insufficient, while if it exceeds 90%, the crosslink density will be high, the viscosity will increase, and biodegradation may be insufficient. The percentage (%) of polymerizable groups present in the modified polylactic acid can be determined in the same manner as the percentage (%) of polymerizable groups present in the modified polycaprolactone.

[0080] -Method for producing modified polylactic acid having polymerizable groups- The method for producing the modified polylactic acid having the polymerizable group is not particularly limited, and can be appropriately selected from known methods depending on the type of the polymerizable group. For example, a method for producing a (meth)acroyl-modified polylactic acid includes reacting a polylactic acid polyol with an acylating agent in a solvent.

[0081] --Polylactic acid polyol-- The polylactic acid polyol may be an appropriately synthesized product or a commercially available product.

[0082] The method for synthesizing the polylactic acid polyol is not particularly limited and can be appropriately selected from known methods, such as a method of reacting polylactic acid (monomer) with a polymerization initiator in a solvent.

[0083] The polylactic acid used as a raw material for synthesizing the polylactic acid polyol is not particularly limited and can be appropriately selected depending on the purpose. Examples include monofunctional polylactic diol, difunctional polylactic diol, trifunctional polylactic diol, tetrafunctional polylactic diol, monofunctional polylactic triol, difunctional polylactic triol, trifunctional polylactic triol, tetrafunctional polylactic triol, monofunctional polylactic tetraol, difunctional polylactic tetraol, trifunctional polylactic tetraol, and tetrafunctional polylactic tetraol. These may be used alone or in combination of two or more. Among these, difunctional polylactic diol, trifunctional polylactic diol, tetrafunctional polylactic diol, monofunctional polylactic triol, difunctional polylactic triol, trifunctional polylactic triol, tetrafunctional polylactic triol, monofunctional polylactic tetraol, difunctional polylactic tetraol, and trifunctional polylactic tetraol are preferred. Monofunctional polylactic acid monools cannot be incorporated into the polylactic acid backbone and therefore cannot form polylactic acid, whereas tetrafunctional polylactic acid tetraols can increase the crosslink density, resulting in increased viscosity and reduced enzymatic degradability.

[0084] In this specification, the constituent units of the polylactic acid may be poly-L-lactic acid consisting only of L-lactic acid, poly-D-lactic acid consisting only of D-lactic acid, or poly-L,D-lactic acid containing both L-lactic acid and D-lactic acid in various molar ratios.

[0085] The polymerization initiator used in the synthesis of the polylactic acid polyol is not particularly limited and can be selected appropriately depending on the purpose, and the same initiators as those described in the <Polymerization initiator> section of the above (Composition for forming enzyme-containing particles) can be used.

[0086] The solvent used in the synthesis of the polylactic acid polyol is not particularly limited and can be selected appropriately depending on the purpose, and the same solvents as those described in the -Solvent- section of the (Enzyme-containing particle forming composition) above can be used.

[0087] Commercially available polylactic acid polyols include, for example, PLA 2205 (polylactic acid diol, weight average molecular weight (Mw): 2,000, manufactured by eSUN), PLA 220M (polylactic acid diol, weight average molecular weight (Mw): 2,000, manufactured by eSUN), and PLA 220B (polylactic acid diol, weight average molecular weight (Mw): 2,000, manufactured by eSUN). These may be used alone or in combination of two or more.

[0088] The weight-average molecular weight (Mw) of the polylactic acid polyol is not particularly limited and can be selected appropriately depending on the purpose, but the lower limit is preferably 300 or more, more preferably 1,000 or more. The upper limit of the weight-average molecular weight (Mw) of the polylactic acid polyol is also not particularly limited and can be selected appropriately depending on the purpose, but is preferably 3,000 or less, more preferably 2,000 or less. If the weight-average molecular weight (Mw) of the polylactic acid polyol is less than 300, the properties derived from the polylactic acid skeleton may not be obtained. If the weight-average molecular weight (Mw) of the polylactic acid polyol exceeds 3,000, the crosslinked structure may be insufficient.

[0089] --Acylating agent-- The acylating agent is not particularly limited and can be selected appropriately depending on the purpose, and the same acylating agents as those described in the "--Acylating Agent--" section of the above (Composition for forming enzyme-containing particles) can be used.

[0090] --solvent-- The solvent is not particularly limited and can be selected appropriately depending on the type of acylating agent, etc. For example, the same solvents as those described in the "--Solvent--" section of the above (Composition for forming enzyme-containing particles) can be used.

[0091] The content of the resin in the enzymatically decomposable resin composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50% by mass to 98% by mass, more preferably 80% by mass to 95% by mass, based on the total amount of the enzymatically decomposable resin composition. If the content of the resin is less than 50% by mass, the original properties of the resin may be lost, and if it exceeds 98% by mass, it may take a long time to decompose the enzymatically decomposable resin composition.

[0092] In the enzyme-degradable resin composition, the content of the enzyme-containing particles per 100 parts by mass of the resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 parts by mass to 50 parts by mass, more preferably 5 parts by mass to 20 parts by mass. If the content of the enzyme-containing particles per 100 parts by mass of the resin is less than 2 parts by mass, the biodegradability of the molded product, which is the cured product of the enzyme-degradable resin composition, may be insufficient. If the content of the enzyme-containing particles per 100 parts by mass of the resin is more than 50 parts by mass, the enzyme may be exposed and diffused on the surface of the molded product, which is the cured product of the enzyme-degradable resin composition, resulting in insufficient durability of the resin.

[0093] <Other ingredients> The other components in the enzyme-decomposable resin composition are not particularly limited and can be selected appropriately for the purpose as long as they do not impair the effects of the present invention, and examples thereof include porous materials, foaming agents, etc. These may be used alone or in combination of two or more.

[0094] <<Porous materials>> The porous material is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include porous materials that can be used as a filler. By including the porous material, the hardness of the molded product, which is the cured product of the enzyme-decomposable resin composition, can be improved, and during decomposition, enzymes can easily act from the porous regions, thereby improving biodegradability. Examples of the porous material include diatomaceous earth, zeolite, and activated carbon.

[0095] <<Foaming agent>> The foaming agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a material that can be contained in the enzyme-degradable resin composition and foamed during curing to make the cured product porous. By using the foaming agent to make a molded product, which is a cured product of the enzyme-degradable resin composition, porous, the biodegradability of the cured product can be improved. Examples of the foaming agent include azodicarbonamide, N,N'-dinitropentamethylenetetramine, 4,4'-oxybisbenzenesulfonylhydrazide, hydrogen carbonates, and carbonates.

[0096] The content of the other components in the enzyme-decomposable resin composition is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose.

[0097] The enzymatically decomposable resin composition can be cured to form a molded article simply and inexpensively, and is therefore suitable for use in producing the molded article of the present invention, which will be described later.

[0098] (Molded body) The molded article of the present invention is produced by curing the enzyme-decomposable resin composition of the present invention, and therefore contains the enzyme-containing particle of the present invention and a polymer obtained by polymerizing a resin that is decomposable by the enzyme contained in the enzyme-containing particle, and further contains other components as necessary.

[0099] The molded article does not decompose during use, but only begins to biodegrade when exposed to water in the environment. That is, the enzyme-containing particles in the molded article have a decomposition start switch function.

[0100] <Other ingredients> The other components in the molded product are not particularly limited and can be appropriately selected depending on the purpose as long as they do not impair the effects of the present invention. These may be used alone or in combination of two or more.

[0101] The method for producing the molded body is not particularly limited as long as it is a method that can harden the enzyme-decomposable resin composition without inactivating the enzyme, and can be selected appropriately depending on the type of polymerization initiator, etc. Examples include a method of hardening the enzyme-decomposable resin composition with heat, a method of hardening the enzyme-decomposable resin composition with light, etc.

[0102] The polymerization initiator is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include those described in the section <Polymerization initiator> of the above (Enzyme-containing particle forming composition). Among these, photopolymerization initiators are preferred.

[0103] The temperature for the thermal curing is not particularly limited as long as it is a temperature at which the enzyme-containing particle-forming composition can be cured without inactivating the enzyme, and can be appropriately selected depending on the type of polymerization initiator, etc.

[0104] The light conditions for curing with light are not particularly limited as long as they are light conditions that can cure the enzymatically decomposable resin composition without inactivating the enzyme, and can be appropriately selected depending on the type of polymerization initiator, etc.

[0105] The shape of the molded product is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a film, a sheet, a tube, etc. Among these, a film is preferred.

[0106] An example of the molded body will be described below with reference to FIG. The molded body 5 has a structure as shown in FIG. 2, in which the enzyme-containing particles 1 are dispersed in a polymer 6 obtained by polymerizing a resin that can be decomposed by the enzyme contained in the enzyme-containing particles. The form of dispersion of the enzyme-containing particles 1 in the polymer 6 is not particularly limited and can be selected appropriately depending on the purpose, but a uniform dispersion is preferred in terms of excellent hydrolysis and biodegradability.

[0107] Next, an example of the biodegradation scheme of the molded article will be described with reference to FIG. When the polymer obtained by polymerizing the enzyme-degradable resin contained in the enzyme-containing particles in the molded body is released into the environment, water penetrates through scratches (holes, cracks, etc.) formed by some kind of stimulus or gaps naturally formed during the formation of the molded body. In the presence of this water, if the enzyme-containing particles 1 have a shell layer 4 (surfactant layer) on their outermost surface, the shell layer 4 dissolves first, followed by the disintegration of the hydrolyzable polymer 2 constituting the core particle of the enzyme-containing particles 1. This gradually exposes and diffuses the enzyme 3 encapsulated in the enzyme-containing particles 1, bringing it into contact with the polymer obtained by polymerizing the enzyme-degradable resin contained in the enzyme-containing particles 1 in the molded body, resulting in the decomposition of the molded body. While a detailed illustration of the polymer obtained by polymerizing the enzyme-degradable resin in Figure 3 is omitted, the polymer obtained by polymerizing the enzyme-degradable resin is present around the enzyme 1.

[0108] The molded article does not decompose during use and has excellent resin durability. Furthermore, the presence of water is the trigger for decomposition, and the molded article exhibits excellent biodegradability when exposed to water in the environment. Therefore, the molded article can be suitably used in various industrial fields, such as automobiles, packaging materials, building materials, IT, agriculture, medicine, and DIY, and can further contribute to reducing environmental impact. [Example]

[0109] The present invention will be specifically explained below by means of synthesis examples, production examples, examples, comparative examples, and test examples, but the present invention is not limited to these synthesis examples, production examples, examples, and test examples.

[0110] (Synthesis Example A-1: ​​Synthesis of acryloyl-modified polycaprolactone 1) A three-necked glass flask equipped with a thermocouple, stirrer, and cooling device was charged with 50 parts by mass of polycaprolactone tetraol (trade name: PCL 410, weight-average molecular weight (Mw): 1,000, manufactured by Daicel Corporation) and 50 parts by mass of tetrahydrofuran, resulting in a dissolved mixture. Separately, 16.29 parts by mass of acrylic acid chloride was measured and slowly added dropwise to the mixture using a pressure-equalizing dropping funnel. Once the acrylic acid chloride was consumed, the pressure-equalizing dropping funnel was removed, and the mixture was refluxed for 120 minutes until the reaction was completely completed. After cooling the resulting mixture to room temperature, the filtrate was evaporated using a rotary evaporator. The residue was dissolved in 100 parts by mass of dichloromethane, transferred to a separatory funnel, neutralized with saturated aqueous sodium bicarbonate, and then separated three times using saturated saline. The dichloromethane layer was transferred to a recovery flask, concentrated with an evaporator, and dried under reduced pressure to obtain the target product [acryloyl-modified polycaprolactone 1] in a yield of 91%.

[0111] (Synthesis Example A-2: Synthesis of acryloyl-modified polycaprolactone 2) The target product [acryloyl-modified polycaprolactone 2] was obtained in a yield of 88% in the same manner as in Synthesis Example A-1, except that in Synthesis Example A-1, polycaprolactone tetraol (trade name: PCL 410, weight-average molecular weight (Mw): 1,000, manufactured by Daicel Corporation) was replaced with polycaprolactone diol (trade name: PCL 210, weight-average molecular weight (Mw): 1,000, manufactured by Daicel Corporation) and the amount of acrylic acid chloride added was changed from 16.29 parts by mass to 8.15 parts by mass.

[0112] (Synthesis Example A-3: Synthesis of acryloyl-modified polycaprolactone 3) The target product [acryloyl-modified polycaprolactone 3] was obtained in a yield of 92% in the same manner as in Synthesis Example A-1, except that in Synthesis Example A-1, polycaprolactone tetraol (trade name: PCL 410, weight-average molecular weight (Mw): 1,000, manufactured by Daicel Corporation) was changed to polycaprolactone triol (trade name: PCL 312, weight-average molecular weight (Mw): 1,250, manufactured by Daicel Corporation) and the amount of acrylic acid chloride added was changed from 16.29 parts by mass to 9.78 parts by mass.

[0113] (Synthesis Example B-1: Synthesis of acryloyl-modified polylactic acid) 20 parts by mass of polylactic acid diol (trade name: PLA 2205, weight average molecular weight (Mw): 2,000, manufactured by eSUN) and 100 parts by mass of tetrahydrofuran were placed in a three-neck glass flask equipped with a thermocouple, a stirrer, and a cooling device and dissolved. 2.5 parts by mass of triethylamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the mixture to obtain a completely dissolved solution. Separately, 10.2 parts by mass of acrylic acid chloride was placed in a sample bottle, dissolved in 20 parts by mass of tetrahydrofuran, and added to the above-mentioned mixture using a pressure-equalizing dropping funnel. Furthermore, while monitoring the thermometer, acrylic acid chloride was carefully and gradually added dropwise to the three-neck flask using the pressure-equalizing dropping funnel. When acrylic acid chloride was completely consumed, the pressure-equalizing dropping funnel was removed, and the mixture was refluxed for 120 minutes until the reaction was completely completed. The above-mentioned synthetic product was cooled to room temperature, and the triethylamine hydrochloride was removed by suction filtration. The filtrate from the reaction mixture was evaporated using a rotary evaporator, and the residue was dissolved in 100 parts by mass of dichloromethane, transferred to a separatory funnel, and separated three times using saturated saline. The dichloromethane layer was transferred to a recovery flask, concentrated using an evaporator, and dried under reduced pressure to obtain the target product, [acryloyl-modified polylactic acid], in a yield of 73%.

[0114] Synthesis Examples A-1 to A-3 and B-1 are summarized in Table 1 below.

[0115] [Table 1]

[0116] (Production Example 1-1: Production of enzyme-containing particles 1) 25 parts by weight of the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was weighed into a stirring cup, and 0.25 parts by weight of a thermal polymerization initiator (trade name: Perloyl® TCP, manufactured by Nippon Oil & Fats Corporation) and 0.025 parts by weight of proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The mixture was stirred twice for 10 minutes at 2,000 rpm to obtain a completely dissolved mixture (22.33 g). 198 parts by weight of ion-exchanged water was weighed into a glass container, and 2 parts by weight of PVA (polyvinyl alcohol) were added. The mixture was stirred for 2 minutes to obtain a completely dissolved mixture. 200 g of this solution was stirred at setting 2 (9,500 rpm) using a homogenizer (T25 digital ULTRA-TURRAX®, manufactured by IKA® Japan KK), and 22.33 g of the above-mentioned mixture was gradually added. Then, the mixture was stirred at setting 2 for another 10 minutes. The separable three-neck flask was then placed in a heatable aluminum hood, and the temperature was raised to 85°C using a hot plate with a stirrer under nitrogen bubbling, and the temperature was maintained for three hours to polymerize [acryloyl-modified polycaprolactone 1]. This polymerization reaction solution was filtered under reduced pressure, washed three times with acetone water, and then filtered again under reduced pressure. The filtered product was dried under reduced pressure for 12 hours to obtain [enzyme-containing particles 1] as a white powder in an 83% yield.

[0117] The white powder obtained in Production Example 1-1 was observed with a scanning electron microscope (SEM) (JSM-6510A, manufactured by JEOL Ltd.), and the results are shown in Figure 4. From this result, the spherical shape of [enzyme-containing particles 1] was confirmed.

[0118] (Production Example 1-2: Production of enzyme-containing particles 2) In Production Example 1-1, [Enzyme-containing particles 2] were obtained as a white powder in a yield of 89% in the same manner as in Production Example 1-1, except that [Acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to [Acryloyl-modified polycaprolactone 2] obtained in Synthesis Example A-2.

[0119] (Production Example 1-3: Production of enzyme-containing particles 3) In Production Example 1-1, [Enzyme-containing particles 3] were obtained as a white powder in a yield of 85% in the same manner as in Production Example 1-1, except that [Acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to [Acryloyl-modified polycaprolactone 3] obtained in Synthesis Example A-3.

[0120] (Production Example 1-4: Production of enzyme-containing particles 4) <Immobilization of enzymes onto porous gels> One mL of distilled water was added to 0.1 g of porous gel (trade name: Bio-Gel P-30, manufactured by BIO-RAD) and centrifuged at 3,500 rpm for 4 minutes. This process was repeated three times to wash the Tris-HCl buffer from the porous gel. The washed porous gel was added to a column, to which an enzyme solution of 3,000 U of proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) per 1 g of porous gel was added. The column was then centrifuged at 3,500 rpm and room temperature (24±1°C) for 4 minutes. The resulting filtrate was again poured into the column, and the same procedure was repeated five times. The column was then freeze-dried at room temperature for 48 hours to obtain the immobilized enzyme.

[0121] <Production of enzyme-containing particles 4> In Production Example 1-1, except that Proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was replaced with the aforementioned [immobilized enzyme], a white powder [enzyme-containing particle 4] was obtained in a yield of 58% using the same method as Production Example 1-1.

[0122] (Comparative Production Example 1-1: Production of Enzyme-Containing Particles 5) In Production Example 1-1, [enzyme-containing particles 5] were obtained as a white powder in a yield of 95% in the same manner as in Production Example 1-1, except that the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to tetra(poly)ethylene glycol diacrylate (TEGDA) (product name: M-240, manufactured by Toagosei Co., Ltd.).

[0123] Comparative Production Example 1-2: Production of cured acryloyl-modified polycaprolactone 25 parts by weight of the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was weighed into a stirring cup, and 1 part by weight of a photopolymerization initiator (trade name: Omnirad 819, manufactured by IGM Resins BV) was added. Stirring was repeated twice for 10 minutes at 2,000 rpm to obtain a completely dissolved composition 1 (22.67 g). 200 parts by weight of ion-exchanged water was weighed into a glass container, and 1 part by weight of PVA (polyvinyl alcohol) was added and stirred for 2 minutes to obtain a completely dissolved composition. 204 g of this solution was stirred at setting 2 (9,500 rpm) using a homogenizer (T25 digital ULTRA-TURRAX®, manufactured by IKA® Japan KK), while 22.67 g of the above composition 1 was gradually added. Then, the mixture was stirred at setting 2 for another 10 minutes. Next, a jacket with a rotary high-pressure mercury lamp attached to the center of the separable three-neck flask was irradiated with nitrogen bubbling while stirring with a magnetic stirrer for 3 hours to polymerize the acryloyl-modified product. After filtering the polymerization reaction solution under reduced pressure, it was washed three times with ion-exchanged water and acetone water, filtered again under reduced pressure, and the filtered product was dried under reduced pressure for 12 hours to obtain a white powder [cured acryloyl-modified polycaprolactone] in a yield of 83%.

[0124] Comparative Production Example 1-3: Polycaprolactone combination thing Containing composition (Production) Comparative Production Example 1-2 was produced in the same manner as Comparative Production Example 1-2, except that the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was replaced with polycaprolactone tetraol (trade name: PCL 410, weight average molecular weight (Mw): 1,000, manufactured by Daicel Corporation), but no white powder was obtained because polymerization did not occur.

[0125] Production Examples 1-1 to 1-4 and Comparative Production Examples 1-1 to 1-3 are summarized in Table 2 below.

[0126] [Table 2]

[0127] (Test Example 1: Changes in enzyme activity due to ultraviolet light) The effect of UV irradiation on the decomposition activity of the enzyme was confirmed by the following method.

[0128] <UV irradiation treatment of enzymes> Proteinase K (Fujifilm Wako Pure Chemical Industries, Ltd.) was used to perform 0 to 6 UV irradiation treatments (1,000 mJ / cm) using a UV conveyor system (iGrandage, iGraphics Co., Ltd.). 2 / time) to obtain [Enzyme-UV0] to [Enzyme-UV6] shown in Table 3 below.

[0129] <Enzyme decomposition test> The polycaprolactone obtained in Comparative Production Example 1-3 was combination thing Containing composition Next, the mass (initial mass) of [polycaprolactone] was measured. combination thing Containing composition ]0.1g and [polycaprolactone combination thing Containing composition ], [Enzyme-UV0] to [Enzyme-UV6] were added so that each was 5 U per 1 mg of [Polycaprolactone combination thing Containing composition The [polycaprolactone] was completely immersed in the enzyme solution, sealed, and left at 37°C for 4 days. combination thing Containing composition The resulting mixture was washed with distilled water, dried under reduced pressure at 40°C for 12 hours, and its mass (mass after enzyme treatment) was measured. The decomposition rate was calculated using the following formula 2 and evaluated based on the following evaluation criteria. The results are shown in Table 3 below. Decomposition rate (%) = (initial mass - mass after enzyme treatment) / initial mass × 100 Equation 2 [Evaluation criteria for enzymatic degradability] ◎: Decomposition rate is 50% or more 〇: Decomposition rate is 25% to 50% △: Decomposition rate is over 0% and less than 25% ×: Decomposition rate is 0%

[0130] [Table 3]

[0131] From the results in Table 3, UV irradiation of the enzyme combination thing Containing composition It was found that the biodegradability of the UV irradiation was affected, and that the enzyme activity decreased further as the number of UV irradiation treatments increased.

[0132] (Test Example 2: Change in enzyme activity of polymer-immobilized enzymes exposed to ultraviolet light) The effect of UV irradiation on the decomposition activity of the polymer-immobilized enzyme was confirmed by the following method.

[0133] <UV irradiation treatment of immobilized enzymes> The enzyme-containing particles 4 obtained in Production Example 1-4 were subjected to 0 to 6 UV irradiator phase grandage irradiation treatments (1,000 mJ / cm) using a UV conveyor device (iGrandage, manufactured by iGraphics Co., Ltd.). 2 / time) to obtain [immobilized enzyme-UV0] to [immobilized enzyme-UV6] shown in Table 4 below.

[0134] <Enzyme decomposition test> In the <Enzyme Degradability Test> of Test Example 1, except that [Enzyme-UV0] to [Enzyme-UV6] were changed to [Immobilized Enzyme-UV0] to [Immobilized Enzyme-UV6], the decomposition rate was calculated in the same manner as in the <Enzyme Degradability Test> of Test Example 1, and evaluated based on the same evaluation criteria as in the <Enzyme Degradability Test> of Test Example 1. The results are shown in Table 4 below.

[0135] [Table 4]

[0136] The results in Table 4 show that even if the enzyme is immobilized with a polymer and then subjected to UV irradiation treatment, the biodegradability is not significantly affected.

[0137] (Test Example 3: Evaluation of biodegradability of cured acroyl-modified polycaprolactone) The biodegradability of a cured product of acroyl-modified polycaprolactone was confirmed by the following methods when an enzyme was externally added, an immobilized enzyme was externally added, an enzyme was encapsulated, and an immobilized enzyme was encapsulated.

[0138] <Enzyme decomposition test> The mass (initial mass) of the [cured product of acroyl-modified polycaprolactone] obtained in Comparative Production Example 1-2, the [enzyme-containing particle 4] obtained in Production Example 1-4, or the [enzyme-containing particle 1] obtained in Production Example 1-1 was measured in advance. Next, the biodegradability of each of the "external enzyme addition," "external immobilized enzyme addition," "enzyme encapsulation," and "immobilized enzyme encapsulation" was confirmed by the following method.

[0139] -External enzyme addition- 20 g of 50 mM phosphate buffer (pH 7.0) was placed in a glass container, and 0.1 g of the [cured product of acroyl-modified polycaprolactone] obtained in Comparative Production Example 1-2 and 10 U of proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added per 1 mg of [cured product of acroyl-modified polycaprolactone]. The [cured product of acroyl-modified polycaprolactone] was completely immersed in the enzyme solution, sealed, and left for 4 days at 37 ° C. Next, fragments of the [cured product of acroyl-modified polycaprolactone] that had not decomposed were removed by filtration using filter paper (qualitative filter paper No. 2, manufactured by Advantec Toyo Co., Ltd.), dried under reduced pressure at 40 ° C. for 12 hours, and the mass (mass after enzyme treatment) was measured.

[0140] -External addition of immobilized enzyme- The test was carried out in the same manner as in the above-mentioned "External Enzyme Addition" except that in the above-mentioned "External Enzyme Addition" proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was replaced with the [immobilized enzyme-UV0] obtained in Test Example 2, and the mass (mass after enzyme treatment) was measured.

[0141] -Enzyme encapsulation- 0.1 g of the enzyme-containing particles 1 obtained in Production Example 1-1 was added to 20 g of 50 mM phosphate buffer (pH 7.0) placed in a glass container, and the enzyme-containing particles 1 were completely immersed in the 50 mM phosphate buffer, sealed, and left to stand for 4 days at 37° C. Next, the resin fragments of the enzyme-containing particles 1 that had not decomposed were removed by filtration using filter paper (qualitative filter paper No. 2, manufactured by Advantec Toyo Co., Ltd.), dried under reduced pressure at 40° C. for 12 hours, and the mass (mass after enzyme treatment) was measured.

[0142] -Immobilized enzyme encapsulation- In the method described above in -Enzyme encapsulation-, the test was carried out in the same manner as the method described above in -Enzyme encapsulation-, except that [Enzyme-containing particle 1] was replaced with [Enzyme-containing particle 4] obtained in Production Example 1-4, and the mass (mass after enzyme treatment) was measured.

[0143] -Control- The test was carried out in the same manner as in the above-mentioned "External Enzyme Addition" except that the enzyme solution of Proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed to water, and the mass (mass after enzyme treatment) was measured.

[0144] For the "external enzyme addition," "external immobilized enzyme addition," "enzyme-encapsulated," and "immobilized enzyme-encapsulated," the decomposition rates were calculated in the same manner as in the <Enzyme Decomposition Test> in Test Example 1, and evaluated based on the same evaluation criteria as in the <Enzyme Decomposition Test> in Test Example 1. The results are shown in Table 5 below.

[0145] [Table 5]

[0146] The degradation rates were highest in the following order: "external enzyme addition" > "external immobilized enzyme addition" > "immobilized enzyme encapsulation" > "enzyme encapsulation" > "control." This shows that when an enzyme is incorporated into a cured product of acroyl-modified polycaprolactone without being immobilized with a polymer and then UV cured, the biodegradability of the enzyme decreases. The difference in decomposition rate between "external immobilized enzyme addition" and "immobilized enzyme encapsulation" was not very large. "Immobilized enzyme encapsulation" showed improved biodegradability compared to the "control."

[0147] (Test Example 4-1: Enzymatic decomposition of resin) The test films used were polycaprolactone type H5C (trade name: PCL H5C, weight average molecular weight (Mw): 50,000, manufactured by Daicel Corporation), polylactic acid type A (trade name: LACEA (registered trademark), weight average molecular weight (Mw): 140,000, manufactured by Mitsui Chemicals, Inc.), polylactic acid type B (trade name: Purasorb (registered trademark) PURASORB PLG 8055, weight average molecular weight (Mw): 140,000, manufactured by Purac), polybutylene succinate type A (trade name: ZM7B01, manufactured by Mitsubishi Chemical Corporation), or polybutylene succinate type B (trade name: ZM9B02, manufactured by Mitsubishi Chemical Corporation). The enzyme used was Lipase PS (trade name: Lipase PS "Amano" SD, manufactured by Amano Enzyme Inc.) or Proteinase K (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0148] <Enzyme decomposition test> The mass (initial mass) of each test film was measured in advance. Next, each test film was placed in a glass container, and an enzyme solution was added so that 10 U of lipase PS or proteinase K was added per 1 mg of each test film. The test film was completely immersed in the enzyme solution, sealed, and left at 37 ° C. for 4 days. As a control, a test film was completely immersed in water, sealed, and left at 37 ° C. for 4 days in the same manner, except that the enzyme solution was changed to water. Next, fragments of the test film that were not decomposed were removed by filtration using filter paper (qualitative filter paper No. 2, manufactured by Advantec Toyo Co., Ltd.), dried under reduced pressure at 40 ° C. for 12 hours, and the mass (mass after enzyme treatment) was measured. The decomposition rate was calculated in the same manner as in the <Enzymatic Decomposition Test> of Test Example 1, and evaluated based on the same evaluation criteria as in the <Enzymatic Decomposition Test> of Test Example 1. The results are shown in Table 6 below.

[0149] [Table 6]

[0150] The results in Table 6 show that polycaprolactone is largely decomposed by lipase PS, while polylactic acid is decomposed by proteinase K.

[0151] (Test Example 4-2: Enzymatic decomposition of resin) -Preparation of test film 1- To 100 parts by mass of the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1, 4% by mass of a photopolymerization initiator (trade name: Omnirad 1173, manufactured by IGM Resins BV) was added, and the mixture was stirred at 2,000 rpm for 2 minutes using a mixer (trade name: Awatori Rentaro ARE-310, manufactured by Thinky Corporation) that could be set to rotate or revolve, to produce a blend. This mixture was poured into a 500 μm-thick silicone rubber frame (length: 4.5 cm x width: 3.5 cm), sandwiched between two sheets of PET film, and irradiated (3 J / cm) on a UV conveyor. 2 ) to obtain Test Film 1.

[0152] -Preparation of test film 2- Test film 2 was obtained in the same manner as in the preparation of test film 1, except that in the preparation of test film 1, [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to [acryloyl-modified polycaprolactone 2] obtained in Synthesis Example A-2.

[0153] -Preparation of test film 3- Test film 3 was obtained in the same manner as in the preparation of test film 1, except that in the preparation of test film 1, the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to the [acryloyl-modified polycaprolactone 3] obtained in Synthesis Example A-3.

[0154] -Preparation of test film 4- Test film 4 was obtained in the same manner as in the preparation of test film 1, except that in the preparation of test film 1, the [acryloyl-modified polycaprolactone 1] obtained in Synthesis Example A-1 was changed to tetra(poly)ethylene glycol diacrylate (TEGDA) (product name: M-240, manufactured by Toagosei Co., Ltd.).

[0155] <Enzyme decomposition test> In the enzymatic decomposition test of Test Example 4-1, the test films were changed to the above-mentioned test films 1 to 4, and only lipase PS was used as the enzyme. The decomposition rate was calculated in the same manner as in the enzymatic decomposition test of Test Example 4-1, and evaluated based on the same evaluation criteria as in the <Enzymatic Decomposition Test> of Test Example 1. As a control, a test film was completely immersed in 50 mM phosphate buffer (pH 7.0), sealed, and left at 37°C for 4 days in the same manner, except that the enzyme solution was changed to phosphate buffer. The results are shown in Table 7 below and Figure 5.

[0156] [Table 7]

[0157] The results in Table 7 show that acryloyl-modified polycaprolactones 1 to 3 are decomposed by lipase PS and hydrolyzed by phosphate buffer.

[0158] Example 1 Synthesis Example BTo 100 parts by mass of the acryloyl-modified polylactic acid obtained in Example 1-1, 10 parts by mass of the enzyme-containing particles 1 obtained in Example 1-1 were added, and 4 parts by mass of a photopolymerization initiator (product name: Omnirad 1173, manufactured by IGMResins B.V.) was further added. The mixture was stirred at 2,000 rpm for 2 minutes in a mixer (product name: Awatori Rentaro ARE-310, manufactured by Thinky Corporation) that could be set to rotate or revolve, to produce a blend. This mixture was poured into a 500 μm-thick silicone rubber frame (length: 4.5 cm x width: 3.5 cm), sandwiched between two sheets of PET film, and irradiated (3 J / cm) on a UV conveyor. 2 ) to obtain [Cured Film 1].

[0159] Example 2 In Example 1, [cured film 2] was obtained in the same manner as in Example 1, except that the [enzyme-containing particles 1] obtained in Production Example 1-1 was replaced with the [enzyme-containing particles 2] obtained in Production Example 1-2.

[0160] Example 3 In Example 1, [cured film 3] was obtained in the same manner as in Example 1, except that the [enzyme-containing particles 1] obtained in Production Example 1-1 was replaced with the [enzyme-containing particles 3] obtained in Production Example 1-3.

[0161] Example 4 In Example 1, [cured film 4] was obtained in the same manner as in Example 1, except that the [enzyme-containing particles 1] obtained in Production Example 1-1 was replaced with the [enzyme-containing particles 4] obtained in Production Example 1-4.

[0162] (Comparative Example 1) In Example 1, [cured film 5] was obtained in the same manner as in Example 1, except that the [enzyme-containing particles 1] obtained in Production Example 1-1 was replaced with the [enzyme-containing particles 5] obtained in Comparative Production Example 1-1.

[0163] (Comparative Example 2) [Cured film 6] was obtained in the same manner as in Example 1, except that the [enzyme-containing particles 1] obtained in Production Example 1-1 was not added (0 parts by mass).

[0164] Cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated for "resin durability" and "enzymatic decomposition" by the following methods. The results are shown in Table 8 below.

[0165] <Evaluation of resin durability> Cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 and 2 were placed in a thermo-hygrostat at 40°C and 95% RH for 7 days and then removed. Each film was then completely immersed in tetrahydrofuran (THF) at room temperature (24°C±1°C), visually observed, and evaluated for "resin durability" based on the following criteria. The evaluation results are shown in Table 8 below. [Evaluation criteria for resin durability] Excellent: The film shape is maintained. Good: The film shape is mostly maintained. Poor: The film has lost its shape.

[0166] <Evaluation of enzymatic decomposition> -Enzymatic decomposition in the presence of water- The masses (initial masses) of cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 to 2 were measured in advance. Next, cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 to 2 were placed in glass containers, water was added, and cured films 1 to 6 were completely immersed in the water, sealed, and left at 37°C for 4 days. Next, fragments of the test film that had not decomposed were removed by filtration using filter paper (qualitative filter paper No. 2, manufactured by Advantec Toyo Co., Ltd.), dried under reduced pressure at 40°C for 12 hours, and their masses (mass after enzyme treatment) were measured. The decomposition rates were calculated from the measured values ​​using the same method as in the <Enzymatic Decomposition Test> in Test Example 1. The results are shown in Table 8 below. In addition, in the presence of water, a decomposition rate of 20% or more is "excellent," a decomposition rate of 5% or more but less than 20% is "good," and a decomposition rate of less than 5% is "poor." "Excellent" or "good" means that there are no problems with use.

[0167] -Enzymatic decomposition in the absence of water- The masses (initial masses) of cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 to 2 were measured in advance. Next, cured films 1 to 6 of Examples 1 to 4 and Comparative Examples 1 to 2 were placed in glass containers, sealed without adding water, and left at 37°C for 4 days. Next, fragments of the test films that had not decomposed were dried under reduced pressure at 40°C for 12 hours, and their masses (mass after enzyme treatment) were measured. The decomposition rates were calculated from the measured values ​​in the same manner as in the <Enzymatic Decomposition Test> of Test Example 1. The results are shown in Table 8 below. It is desirable that the substance does not decompose in the absence of water, and a decomposition rate of less than 5% is considered "excellent," while a decomposition rate of 5% or more is considered "poor."

[0168] [Table 8]

[0169] The results in Table 8 show that in Example 1, the resin durability was excellent and the enzymatic degradability was also good. In Example 2, the resin durability was slightly reduced compared to Example 1, but the enzymatic degradability was improved. This is thought to be because the crosslink density was lowered due to the fact that the functional groups of the polycaprolactone polyol, the raw material for the enzyme-containing particles in Example 2, were bifunctional. In Example 3, the enzymatic degradability was slightly reduced compared to Example 1. This is thought to be because the crosslink density and hydrolysis property were between those of Examples 1 and 2, but the amount of caprolactone segment introduced was large. In Example 4, the enzymatic degradability was slightly reduced compared to Example 1. This is thought to be because the immobilized enzyme encapsulated in the polymer was less likely to diffuse outside the system than a single enzyme. Comparative Example 1 In the comparative example, the resin did not disintegrate and decomposability was significantly reduced. 2 In the case of the sample containing no enzyme-containing particles, no enzymatic degradation occurred. [Industrial Applicability]

[0170] The enzyme-containing particle-forming composition can be cured to form enzyme-containing particles simply and inexpensively, and is therefore suitable for use in producing the enzyme-containing particles of the present invention. The enzyme-containing particles have excellent durability and do not lose their enzymatic activity due to external stimuli such as heat or UV irradiation, while also having excellent hydrolysis properties in the presence of water. Therefore, they are suitable for use in the molded body of the present invention, and can be suitably imparted with a decomposition start switch function that initiates biodegradation only when the molded body is exposed to water in the environment. The enzymatically decomposable resin composition can be cured to form a molded article simply and inexpensively, and is therefore suitable for use in producing the molded article of the present invention. The molded article does not decompose during use and has excellent resin durability. Furthermore, the presence of water is the trigger for decomposition, and the molded article exhibits excellent biodegradability when exposed to water in the environment. Therefore, the molded article can be suitably used in various industrial fields, such as automobiles, packaging materials, building materials, IT, agriculture, medicine, and DIY, and can further contribute to reducing environmental impact. [Explanation of symbols]

[0171] 1: Enzyme-containing particles 2: Hydrolyzable polymer 3: Enzymes 4: Shell layer 5: Molded body 6: Polymer

Claims

1. A polymer capable of forming a hydrolyzable polymer, the polymer comprising modified polycaprolactone in which polycaprolactone is modified with a polymerizable group; an enzyme that does not decompose the hydrolyzable polymer formed by polymerization of the polymer in the absence of water; a polymerization initiator for polymerizing the polymer; A composition for forming enzyme-containing particles, comprising:

2. An enzyme-containing particle obtained by curing the enzyme-containing particle-forming composition according to claim 1.

3. The enzyme-containing particle according to claim 2, a resin that is decomposable by the enzyme contained in the enzyme-containing particles, has a polymerizable group, and has a weight-average molecular weight of 3,000 or less; An enzyme-decomposable resin composition comprising:

4. A molded article obtained by curing a resin contained in the enzymatically decomposable resin composition according to claim 3.

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