Resin article and method for producing resin article

Abstract

Provided is a resin article in which a biodegradable resin is used as a substrate and which comprises a barrier film that has an excellent water vapor transmission rate. The resin article comprises: a substrate layer including a biodegradable resin; and a barrier film disposed on the surface of the substrate layer. The barrier film has a surface roughness Ra1 of less than 0.300 μm; and the resin article has a water vapor transmission rate of 0.01-20.00 g / (m2•24 h).

Description

Resin article and method for manufacturing a resin article

[0001] The present invention relates to a resin article and a method for manufacturing a resin article.

[0002] Plasma CVD is widely used as a coating technique for substrate surfaces with large surface irregularities. A source gas containing HMDSO is widely used for forming a barrier film on a substrate surface by plasma CVD. It is known that forming a barrier film using the source gas together with oxygen gas improves the barrier performance of the substrate on which the barrier film is formed.

[0003] The substrate is made of various resins, including biodegradable resins and resins other than biodegradable resins.

[0004] As a method for forming a barrier film on the surface of a substrate using a biodegradable resin, the techniques described in Patent Documents 1 to 4 are known.

[0005] Japanese Patent Publication No. 2007-302283 Japanese Patent Publication No. 2007-261077 WO2008 / 013314 WO2020 / 262619

[0006] As a result of intensive research by the present inventors, it was found that the surface roughness of biodegradable resins increases when exposed to plasma, and that the surface roughness of biodegradable resins increases significantly, particularly in the presence of oxygen radicals formed when oxygen is dissociated by plasma, which can result in the barrier performance (water vapor permeability) of the barrier film provided on the surface of the biodegradable resin being impaired.

[0007] An object of the present invention is to provide a resin article having a substrate layer made of a biodegradable resin and provided with a barrier film having excellent water vapor permeability.

[0008] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that, when a resin article is produced by providing a barrier film on the surface of a substrate layer containing a biodegradable resin by a plasma CVD method or the like, it is possible to provide a resin article having a substrate layer made of a biodegradable resin and provided with a barrier film having excellent water vapor permeability by (i) adjusting the surface roughness of the barrier film and (ii) adjusting the water vapor permeability of the resin article, and have thereby completed the present invention. One embodiment of the present invention encompasses the following inventions.

[0009] [1] A resin article comprising a substrate layer containing a biodegradable resin and a barrier film on the surface of the substrate layer, wherein the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor transmission rate of the resin article is 0.01 to 20.00 g / (m ２ - 24h).

[0010] [2] The resin article according to [1], wherein when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1-Ra0<0.200 μm.

[0011] [3] The resin article according to [1] or [2], wherein the barrier film is formed by a plasma CVD method.

[0012] [4] The resin article according to any one of [1] to [3], wherein the barrier film contains SiCxOy and / or SiOz (wherein x, y, and z each independently represent an integer of 0 to 2).

[0013] [5] The resin article according to any one of [1] to [4], wherein the thickness of the barrier film is less than 100 nm.

[0014] [6] The resin article according to any one of [1] to [5], wherein the barrier film is composed of a single layer.

[0015] [7] The resin article according to any one of [1] to [6], wherein the thickness of the substrate layer containing the biodegradable resin is 500 μm or less.

[0016] [8] The resin article according to any one of [1] to [7], wherein the biodegradable resin comprises an aliphatic polyester resin and / or an aliphatic aromatic polyester resin.

[0017] [9] The resin article according to any one of [1] to [7], wherein the biodegradable resin comprises a polyhydroxyalkanoate resin.

[0018]

[10] A method for producing a resin article, comprising a film-forming step of supplying a reactive gas onto a substrate layer containing a biodegradable resin and forming a barrier film on the surface of the substrate layer by plasma CVD, wherein the reactive gas is a mixed gas containing an organometallic compound gas and an oxidizing gas, the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor permeability of the resin article is 0.01 to 20.00 g / (m ２ 24h).

[0019]

[11] The manufacturing method according to

[10] , wherein when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1-Ra0<0.200 μm.

[0020]

[12] The method according to

[10] or

[11] , wherein the organometallic compound is an organometallic compound containing an oxygen atom in the molecule.

[0021]

[13] The method according to

[12] , wherein the organometallic compound containing an oxygen atom in the molecule is hexamethyldisiloxane.

[0022]

[14] The oxidizing gas is O ２ , CO ２ , or N ２ The method according to any one of

[10] to

[13] , wherein O is O.

[0023] According to one aspect of the present invention, a resin article can be provided that includes a barrier film having an excellent water vapor permeability and that uses a biodegradable resin as a substrate layer.

[0024] An example of an embodiment of the present invention will be described in detail below, but the present invention is not limited to this. Various modifications of the present invention are possible within the scope of the claims. Furthermore, embodiments or examples obtained by appropriately combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic literature and patent documents described in this specification are incorporated herein by reference. Unless otherwise specified in this specification, the term "X to Y" representing a numerical range means "greater than or equal to X and less than or equal to Y."

[0025] [1. Resin Article] A resin article according to one embodiment of the present invention is a resin article comprising a substrate layer containing a biodegradable resin (or a substrate layer made of a biodegradable resin) and a barrier film on the surface of the substrate layer, wherein the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor transmission rate of the resin article is 0.01 to 20.00 g / (m ２ - 24h) is a resin article.

[0026] In the technique described in the cited document 1, N ２ However, plasma treatment using a gas is required. The techniques described in Patent Documents 2 and 3 require the formation of multiple barrier films using different raw material gases, which complicates the process and reduces productivity. The technique described in Patent Document 4 discloses a method for forming a barrier film on the surface of a biodegradable resin without using an external lubricant, but the biodegradable resin on which such a barrier film has been formed has the problem of being difficult to mold.

[0027] On the other hand, according to one embodiment of the present invention, a resin article having a substrate layer made of a biodegradable resin and a barrier film having excellent water vapor permeability can be realized. Also, according to one embodiment of the present invention, a resin article having a substrate layer made of a biodegradable resin and a barrier film having excellent oxygen permeability can be realized.

[0028] In a resin article according to one embodiment of the present invention, when the surface roughness of the substrate layer before the formation of the barrier film is defined as Ra0, the surface roughness Ra1 of the barrier film preferably satisfies the following condition: Ra1-Ra0<0.200 μm. This configuration makes it possible to realize a resin article having a substrate layer made of a biodegradable resin and a barrier film with a superior water vapor permeability.

[0029] A resin article according to one embodiment of the present invention is preferably a resin article that satisfies the following conditions: (1) the surface roughness Ra1 of the barrier film is less than 0.150 μm, or (2) when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film is Ra1-Ra0<0.100 μm. Note that a resin article according to one embodiment of the present invention may be a resin article that satisfies both of the above conditions (1) and (2).

[0030] According to the above-mentioned configuration, it is possible to realize a resin article having a substrate layer made of a biodegradable resin and provided with a barrier film having an even more excellent water vapor permeability.

[0031] A resin article according to one embodiment of the present invention is preferably a resin article that satisfies the following conditions: (3) the surface roughness Ra1 of the barrier film is less than 0.100 μm, or (4) when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film is Ra1-Ra0<0.050 μm. Note that a resin article according to one embodiment of the present invention may satisfy both of the above-mentioned conditions (3) and (4).

[0032] According to the above-mentioned configuration, it is possible to realize a resin article having a substrate layer made of a biodegradable resin and provided with a barrier film having the highest water vapor permeability.

[0033] The lower limit of the surface roughness Ra1 of the barrier film is not limited, and may be, for example, 0.010 μm or more, 0.020 μm or more, 0.030 μm or more, 0.040 μm or more, 0.050 μm or more, 0.060 μm or more, 0.070 μm or more, 0.080 μm or more, 0.090 μm or more, or 0.100 μm or more. According to this configuration, it is possible to more effectively realize a resin article having a barrier film with excellent water vapor permeability, which uses a biodegradable resin as a substrate layer.

[0034] The surface roughness Ra0 of the substrate layer before the barrier film is formed and the surface roughness Ra1 of the barrier film can be calculated from the images obtained using a microscope of the substrate layer before the barrier film is formed (specifically, an image of the surface of the substrate layer) and the composite of the barrier film and the substrate layer after the barrier film is formed (specifically, an image of the surface of the composite), as the arithmetic mean roughness (Ra0) of the surface of the substrate layer before the barrier film is formed and the arithmetic mean roughness (Ra1) of the surface of the composite of the barrier film and the substrate layer (specifically, the surface of the composite on the side on which the barrier film is formed).

[0035] The barrier film may be formed by a plasma CVD method. When a biodegradable resin is exposed to plasma, its surface roughness increases. In particular, when oxygen radicals resulting from oxygen dissociation by plasma are present, the surface roughness of the biodegradable resin increases significantly. As a result, the barrier performance (water vapor permeability) of the barrier film provided on the surface of the biodegradable resin may be impaired. According to one embodiment of the present invention, the degradation of the barrier performance of the barrier film can be prevented.

[0036] As will be described later in [2. Method for manufacturing a resin article], a resin article according to one embodiment of the present invention can be manufactured by a film-forming step in which a reactive gas is supplied onto a substrate layer containing a biodegradable resin, and a barrier film is formed on the surface of the substrate layer by plasma CVD.

[0037] In the film forming process, for example, a mixed gas containing an organometallic compound gas and an oxidizing gas can be used as the reactive gas. More specifically, the reactive gas can be hexamethyldisiloxane (C ６ H １８ Si ２ O: HMDSO) and O ２ A mixed gas containing the above may be used.

[0038] Hexamethyldisiloxane and O ２ When a mixed gas containing HMDSO and O is used, for example, a plasma reaction shown in the following formula 1 occurs, and SiCxOy and / or SiOz (x, y, and z are each independently 0 to 2) may be generated as a product.２ x, y, and z can each independently take a value of 0 to 2 depending on the ratio of

[0039] In the case of Formula 1, SiCxOy (specifically, SiCO: low barrier) can be produced by the first reaction, and SiOz (specifically, SiO ２ : high barrier) may occur.

[0040] Hexamethyldisiloxane and O ２ When the barrier film is formed by plasma CVD using a mixed gas containing the above, the barrier film may contain SiCxOy and / or SiOz (where x, y, and z are each independently 0 to 2).

[0041] If the amount of SiCxOy contained in the barrier film is large (for example, when the weight of the barrier film is taken as 100 wt%, the amount of SiCxOy contained in the barrier film is, for example, more than 50 wt%, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, or 100 wt%), advantages such as improved flexibility of the barrier film and less susceptibility to cracking, or improved adhesion between the barrier film and the substrate layer can be obtained.

[0042] On the other hand, if the amount of SiOz contained in the barrier film is large (for example, when the weight of the barrier film is taken as 100 wt%, the amount of SiOz contained in the barrier film is, for example, more than 50 wt%, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, or 100 wt%), an advantage of having low gas permeability and excellent barrier performance can be obtained.

[0043] The upper limit of the thickness of the barrier film is not limited, and may be, for example, 100 nm or less (or less than 100 nm), 90 nm or less (or less than 90 nm), 80 nm or less (or less than 80 nm), 70 nm or less (or less than 70 nm), 60 nm or less (or less than 60 nm), 50 nm or less (or less than 50 nm), 40 nm or less (or less than 40 nm), 30 nm or less (or less than 30 nm), 20 nm or less (or less than 20 nm), or 10 nm or less (or less than 10 nm). On the other hand, the lower limit of the thickness of the barrier film is not limited, and may be, for example, 1 μm or more, 5 μm or more, or 10 μm or more. This configuration makes it possible to more effectively realize a resin article having a barrier film with excellent water vapor permeability, which uses a biodegradable resin as a substrate layer. Furthermore, with a resin article according to one embodiment of the present invention, even if the barrier film is thin, it can be highly effective in preventing or reducing water vapor permeation.

[0044] The barrier film may be composed of a single layer or multiple layers, but is preferably composed of a single layer. In the resin article according to one embodiment of the present invention, even a thin barrier film composed of a single layer can be highly effective in preventing or reducing water vapor permeation.

[0045] The substrate layer contains a biodegradable resin. The substrate layer may be made of a biodegradable resin. From the viewpoint of achieving higher biodegradability, achieving a faster biodegradation rate, and protecting the global environment, the substrate layer is preferably made of a biodegradable resin.

[0046] The upper limit of the thickness of the substrate layer containing a biodegradable resin (or the substrate layer made of a biodegradable resin) is not limited, and may be, for example, 500 μm or less, 300 μm or less, 100 μm or less, 75 μm or less, 50 μm or less, 25 μm or less, or 10 μm or less. Since the thinner the substrate layer, the more likely it is that the surface roughness will increase when exposed to plasma. Therefore, when the thickness of the substrate layer is 500 μm or less, the effect of preventing a decrease in the barrier performance of the barrier film according to one embodiment of the present invention is significant, and when the thickness of the substrate layer is 100 μm or less, the effect of preventing a decrease in the barrier performance of the barrier film is even greater.

[0047] On the other hand, the lower limit of the thickness of the substrate layer containing the biodegradable resin (or the substrate layer made of the biodegradable resin) is not limited and may be, for example, 1 μm or more, 5 μm or more, or 10 μm or more. This configuration makes it possible to more effectively realize a resin article having a substrate layer made of a biodegradable resin and a barrier film with a superior water vapor permeability.

[0048] The biodegradable resin contained in the substrate layer preferably contains an aliphatic polyester resin and / or an aliphatic-aromatic polyester resin. When the biodegradable resin contained in the substrate layer contains an aliphatic polyester resin that is likely to increase in surface roughness when exposed to plasma, an embodiment of the present invention can prevent a decrease in the barrier performance of the barrier film.

[0049] The biodegradable resin contained in the substrate layer preferably contains a polyhydroxyalkanoate resin. When the biodegradable resin contained in the substrate layer contains a polyhydroxyalkanoate resin that is particularly prone to increase in surface roughness when exposed to plasma, an embodiment of the present invention can prevent a decrease in the barrier performance of the barrier film.

[0050] The biodegradable resin forming the substrate layer is not limited, and may be, for example, one or more resins selected from the group consisting of aliphatic aromatic polyester resins containing one or more dicarboxylic acid units selected from the group consisting of aliphatic dicarboxylic acid units and aromatic dicarboxylic acid units, and one or more diol units selected from the group consisting of aliphatic diol units and aromatic diol units, and aliphatic polyester resins containing aliphatic dicarboxylic acid units and aliphatic diol units (excluding polyhydroxybutyrate resins).

[0051] The aliphatic dicarboxylic acid unit may be an aliphatic dicarboxylic acid and / or its derivatives that form esters. The aliphatic dicarboxylic acid unit is not particularly limited, but may be, for example, one having 2 to 30 carbon atoms, preferably 2 to 18 carbon atoms, and more preferably 4 to 10 carbon atoms. The aliphatic dicarboxylic acid unit may be linear or branched.

[0052] Specific examples of the aliphatic dicarboxylic acid unit include oxalic acid, malonic acid, succinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, α-ketoglutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, brassylic acid, fumaric acid, 2,2-dimethylglutaric acid, suberic acid (suberic acid), diglycolic acid, oxaloacetic acid, glutamic acid, aspartic acid, itaconic acid, and maleic acid.

[0053] The aliphatic dicarboxylic acids and / or their ester-forming derivatives may be used singly or in combination. Preferably, one or more selected from the group consisting of succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, and their ester-forming derivatives may be used. More preferably, one or more selected from the group consisting of succinic acid, adipic acid, sebacic acid, and their ester-forming derivatives may be used. Succinic acid, azelaic acid, sebacic acid, and brassylic acid have the advantage of being obtained from renewable raw materials.

[0054] The aromatic dicarboxylic acid unit is not particularly limited, but it is preferable to use one or more selected from the group consisting of terephthalic acid and its derivatives that form esters. Examples of terephthalic acid derivatives that form esters include dimethyl terephthalate. Furthermore, heterocyclic aromatic dicarboxylic acids can also be used as the aromatic dicarboxylic acid unit, such as 2,5-furandicarboxylic acid.

[0055] The aliphatic diol unit is not particularly limited, but may be, for example, a branched or linear alkanediol having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms.

[0056] Specific examples of the alkanediol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-isobutyl-1,3-propanediol, and 2,2,4-trimethyl-1,6-hexanediol. As the alkanediol, it is preferable to use one or more selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propanediol (neopentyl glycol).

[0057] The aromatic diol unit is not particularly limited, but for example, a cycloalkanediol having 5 to 10 carbon atoms can be used.

[0058] Specific examples of the cycloalkanediol include cyclopentanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

[0059] As the diol unit, 1,4-butanediol and 1,3-propanediol are preferred. In particular, 1,4-butanediol in combination with adipic acid is preferred, and 1,3-propanediol in combination with sebacic acid is preferred. 1,3-propanediol has the advantage of being obtainable as a renewable raw material.

[0060] Examples of the aliphatic aromatic polyester resin include polybutylene adipate terephthalate (PBAT) resin, polybutylene sebacate terephthalate resin, and polybutylene succinate terephthalate resin. Examples of the polybutylene adipate terephthalate (PBAT) resin include polybutylene adipate terephthalate (PBAT) and polybutylene azelate terephthalate (PBAzT). Examples of the polybutylene succinate terephthalate resin include polybutylene sebacate terephthalate (PBSeT) and polybutylene succinate terephthalate (PBST). In particular, polybutylene adipate terephthalate (PBAT) is preferably used as the aliphatic aromatic polyester resin because of its excellent physical properties such as tensile elongation at break and moldability.

[0061] Polybutylene adipate terephthalate (PBAT) refers to a random copolymer of 1,4-butanediol, adipic acid, and terephthalic acid. Of these, PBAT obtained by reacting (a) a mixture consisting primarily of 35 mol% to 95 mol% of adipic acid or its ester-forming derivative, or a mixture thereof, and 5 mol% to 65 mol% of terephthalic acid or its ester-forming derivative, or a mixture thereof (the sum of the mol% of each monomer is 100 mol%) with (b) a mixture containing butanediol (wherein the molar ratio of (a):(b) is 0.4:1 to 1.5:1), as described in JP-A-10-508640, etc., is preferred. Commercially available PBATs include, for example, "Ecoflex" (registered trademark) manufactured by BASF.

[0062] The aliphatic aromatic polyester resin is not particularly limited, but for example, the weight average molecular weight is preferably from 1,000 to 100,000, more preferably from 9,000 to 75,000, and even more preferably from 10,000 to 50,000. In one or more embodiments of the present invention, the weight average molecular weight of the resin refers to the weight average molecular weight in terms of polystyrene measured by gas permeation chromatography (GPC) using chloroform as a solvent.

[0063] The aliphatic aromatic polyester resin is not particularly limited, but preferably has a melting point of 60°C or higher and 170°C or lower, more preferably 80°C or higher and 150°C or lower.

[0064] Examples of the aliphatic polyester resins include polybutylene succinate (PBS) resins, polycaprolactone (PCL) resins, and polyhydroxyalkanoate resins (excluding, for example, polyhydroxybutyrate resins). Examples of the polybutylene succinate (PBS) resins include polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA). Polyhydroxyalkanoate resins other than polyhydroxybutyrate resins refer to polyhydroxyalkanoate resins that do not contain 3-hydroxybutyrate as a monomer component. Examples of the polyhydroxyalkanoate resins include polyglycolic acid, polylactic acid, and poly-4-hydroxybutyrate resins.

[0065] The poly-4-hydroxybutyrate resin may be a poly(4-hydroxybutyrate) having only 4-hydroxybutyrate as a repeating unit, or may be a copolymer of 4-hydroxybutyrate and another hydroxyalkanoate.

[0066] The biodegradable resin forming the substrate layer is not limited, and for example, at least one selected from the group consisting of poly(3-hydroxyalkanoate), polylactic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, polybutylene succinate terephthalate, polycaprolactone, modified starch, modified cellulose, cellulose acetate, polyglycolic acid, and polyvinyl alcohol can be used.

[0067] In this specification, poly(3-hydroxyalkanoate) (hereinafter also referred to as P3HA) means a biodegradable aliphatic polyester (preferably a polyester containing no aromatic ring). P3HA is a polymer having the general formula: [-CHR-CH ２ -CO-O-] (wherein R is C ｎ H ２ｎ＋１ where n is an integer of 1 to 15.) as an essential repeating unit. Among them, polyhydroxyalkanoates containing the repeating unit in an amount of 50 mol % or more, more preferably 70 mol % or more, based on the total repeating units of the monomer (100 mol %) are preferred.

[0068] Examples of P3HA include poly(3-hydroxybutyrate) (P3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate). In one embodiment of the present invention, the substrate layer may be formed using at least one selected from these P3HAs.

[0069] P3HA produced by microorganisms (microbially produced P3HA) is typically P3HA composed solely of D-form (R-form) polyhydroxyalkanoic acid monomer units. Among microbially produced P3HAs, P3HB, P3HB3HH, P3HB3HV, P3HB3HV3HH, and P3HB4HB are preferred, with P3HB, P3HB3HH, P3HB3HV, and P3HB4HB being more preferred, due to ease of industrial production.

[0070] When P3HA (particularly microbially produced P3HA) contains 3-hydroxybutanoic acid (3HB) repeat units as an essential monomer unit, the monomer composition ratio is, from the viewpoint of the balance between the flexibility and strength of P3HA, preferably 80 mol% to 99 mol% of 3-hydroxybutanoic acid (3HB) repeat units out of all repeat units (100 mol%), more preferably 85 mol% to 97 mol%. When the composition ratio of 3HB repeat units is 80 mol% or more, the rigidity of P3HA is further improved, and the crystallinity does not become too low, which tends to make purification easier. On the other hand, when the composition ratio of 3HB repeat units is 99 mol% or less, the flexibility of P3HA tends to be further improved. The monomer composition ratio of P3HA can be measured by gas chromatography or the like (see, for example, WO 2014 / 020838).

[0071] The microorganism that produces microbially produced P3HA is not particularly limited as long as it is a microorganism capable of producing P3HAs. For example, P3HB-producing bacteria include Bacillus megaterium, discovered in 1925, as well as natural microorganisms such as Cupriavidus necator (formerly classified as Alcaligenes eutrophus, Ralstonia eutropha) and Alcaligenes latus. It is known that P3HB accumulates in the cells of these microorganisms.

[0072] Examples of bacteria that produce copolymers of hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB. In particular, with regard to P3HB3HH, in order to increase the productivity of P3HB3HH, Alcaligenes eutrophus AC32 strain (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)) into which genes for the P3HA synthase group have been introduced can be used, and microbial cells obtained by culturing these microorganisms under appropriate conditions and accumulating P3HB3HH within the cells can be used. In addition to the above, genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used depending on the P3HA to be produced, or microbial cells obtained by culturing under optimized culture conditions, including the type of substrate, and accumulating P3HA within the cells may be used.

[0073] The molecular weight of P3HA is not particularly limited as long as it exhibits substantially sufficient physical properties for the intended application. The weight-average molecular weight of P3HA is, for example, preferably in the range of 50,000 to 3,000,000, more preferably 100,000 to 1,000,000, and even more preferably 300,000 to 700,000. By setting the weight-average molecular weight to 50,000 or more, the strength of the substrate layer tends to be further improved. On the other hand, by setting the weight-average molecular weight to 3,000,000 or less, the processability tends to be further improved and molding tends to be easier. The P3HA may be uncrosslinked P3HA or may be uniformly and appropriately crosslinked P3HA, and the weight-average molecular weight is a value measured before crosslinking the P3HA.

[0074] The weight-average molecular weight can be measured using gel permeation chromatography (GPC) (Shodex GPC-101 manufactured by Showa Denko K.K.) with a polystyrene gel (Shodex K-804 manufactured by Showa Denko K.K.) as a column, chloroform as a mobile phase, and the molecular weight can be calculated as a polystyrene-equivalent. In this case, a calibration curve is prepared using polystyrenes with weight-average molecular weights of 31,400, 197,000, 668,000, and 1,920,000. As the column for the GPC, a column appropriate for measuring the molecular weight may be used.

[0075] The substrate layer may contain components other than the biodegradable resin, such as a lubricant, a crystal nucleating agent, a resin other than the biodegradable resin, and other components.

[0076] As used herein, the term "external lubricant" refers to a substance that bleeds onto the surface of a resin article and promotes the release of the resin article from a roll or mold or the opening of a double-layered film, such as an inflation film. The external lubricant is not particularly limited as long as it satisfies the above definition, but examples include fatty acid monoamides and fatty acid bisamides. Fatty acids that constitute fatty acid amides include fatty acids having 12 to 30 carbon atoms or fatty acids having 18 to 22 carbon atoms, such as higher fatty acids such as erucic acid, palmitic acid, and oleic acid. Specific examples of fatty acid amides include erucic acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, methylene bisstearic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, and ethylene biserucic acid amide.

[0077] The external lubricant may be used alone or in combination of two or more. The content of the external lubricant may be appropriately set and is not particularly limited.

[0078] The substrate layer may contain a "nucleating agent." When the substrate layer contains a nucleating agent, the crystallization rate of P3HA is increased, and molding processability is improved. As the nucleating agent, for example, a polyhydric alcohol is preferably used. Examples of polyhydric alcohols include pentaerythritol, galactitol, and mannitol.

[0079] The nucleating agent may be used alone or in combination of two or more. The content of the nucleating agent may be appropriately set and is not particularly limited.

[0080] The substrate layer may contain a “resin other than biodegradable resin.” The resin other than biodegradable resin is not limited.

[0081] The resin other than the biodegradable resin may be used alone or in combination of two or more. The content of the resin other than the biodegradable resin may be appropriately set and is not particularly limited.

[0082] For example, when the total amount of the biodegradable resin and other resins other than the biodegradable resin is taken as 100% by weight, the upper limit of the amount of other resins other than the biodegradable resin may be less than 50% by weight, 40% by weight or less, 30% by weight or less, 20% by weight or less, 10% by weight or less, 5% by weight or less, or 1% by weight or less. When the total amount of the biodegradable resin and other resins other than the biodegradable resin is taken as 100% by weight, the lower limit of the amount of other resins other than the biodegradable resin may be 0% by weight, 0.01% by weight or more, 0.1% by weight or more, or 1% by weight or more.

[0083] The substrate layer may contain "other components." The substrate layer may contain organic or inorganic fillers, etc., to the extent that the effects of the present invention are not impaired. From the viewpoint of biodegradability and carbon neutrality of the resulting resin article, the other components are preferably, for example, naturally derived materials (e.g., wood-based materials such as wood chips, wood flour, and sawdust, rice husks, rice flour, starch, corn starch, rice straw, wheat straw, and natural rubber).

[0084] The organic or inorganic fillers can be used alone or in combination of two or more. The content of the organic or inorganic fillers can be appropriately set and is not particularly limited.

[0085] The substrate layer may contain, as other components, one or more selected from the group consisting of pigments, colorants (e.g., dyes), odor absorbers (e.g., activated carbon and zeolite), fragrances (e.g., vanillin and dextrin), antioxidants, weather resistance improvers, UV absorbers, water repellents, antibacterial agents, sliding properties improvers, and other secondary additives. The contents of these other components can also be set appropriately.

[0086] The water vapor permeability of the resin article is not limited, and may be, for example, 0.10 to 15.00 g / (m ２ ・24h), or 1.00 to 10.00 g / (m ２ According to this configuration, it is possible to more effectively realize a resin article having a substrate layer made of a biodegradable resin and a barrier film with a superior water vapor permeability.

[0087] The resin article according to one embodiment of the present invention is a resin article having a substrate layer made of a biodegradable resin and including a barrier film with excellent water vapor permeability, and therefore can be used, for example, as a waterproof sheet, a plastic bottle, a packaging material for food, a packaging material for medicines, a protective material for electronic devices, or a packaging material for daily necessities such as liquid detergents, etc. Of course, the uses of the resin article according to one embodiment of the present invention are not limited to these.

[0088] [2. Method for manufacturing a resin article] A method for manufacturing a resin article according to one embodiment of the present invention will be described below. Note that the method for manufacturing a resin article according to one embodiment of the present invention may be the method for manufacturing a resin article described in [1. Resin article] above. Descriptions of the matters described in [1. Resin article] above will basically be omitted.

[0089] A method for producing a resin article according to one embodiment of the present invention includes a film-forming step of supplying a reactive gas onto a substrate layer containing a biodegradable resin (or a substrate layer made of a biodegradable resin) to form a barrier film on the surface of the substrate layer by plasma CVD, wherein the reactive gas is a mixed gas containing a gas of an organometallic compound and an oxidizing gas, and the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor transmission rate of the resin article is 0.01 to 20.00 g / (m ２ 24h).

[0090] In the method for manufacturing a resin article according to one embodiment of the present invention, when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film may satisfy Ra1-Ra0<0.200 μm.

[0091] In the method for producing a resin article according to one embodiment of the present invention, (i) the surface roughness Ra1 of the barrier film may be less than 0.150 μm, or, when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film may satisfy Ra1−Ra0<0.100 μm, and (ii) the surface roughness Ra1 of the barrier film may be less than 0.100 μm, or, when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film may satisfy Ra1−Ra0<0.050 μm.

[0092] In the film-forming step, a reactive gas is supplied onto a substrate layer containing a biodegradable resin, and a barrier film is formed on the surface of the substrate layer by plasma CVD. Plasma CVD can be performed using a commercially available plasma CVD device. Details of the configuration of the substrate layer and the barrier film have been described above in [1. Resin Article], and therefore will not be described here.

[0093] The reactive gas is a mixed gas containing an organometallic compound gas and an oxidizing gas.

[0094] Examples of the organometallic compound include organometallic compounds that do not contain oxygen atoms in the molecule, and organometallic compounds that contain oxygen atoms in the molecule (for example, siloxane compounds and organotitanium compounds).

[0095] Examples of the organometallic compound containing an oxygen atom in the molecule include organosilane compounds (e.g., methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane), organosiloxane compounds (e.g., octamethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, and hexamethyldisiloxane), and organotitanium compounds (e.g., alkoxytitanium).

[0096] Examples of organometallic compounds that do not contain oxygen atoms in the molecule include organoaluminum compounds (e.g., trialkylaluminum), organotitanium compounds (e.g., tetraalkyltitanium), and organosilicon compounds (e.g., silane compounds (e.g., hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, trimethylsilane, ethyltrimethylsilane, trimethylvinylsilane, diethylsilane, propylsilane, phenylsilane, and dimethylphenylsilane), and silazanes).

[0097] The oxidizing gas may be, for example, an oxidizing gas that generates oxygen radicals by plasma. More specifically, the oxidizing gas may be, for example, O ２ , CO ２ , and N ２ As the oxidizing gas, one of these may be used alone, or two or more of these may be used in combination.

[0098] When an oxidizing gas that generates oxygen radicals by plasma is used, the oxygen radicals tend to increase the surface roughness of the biodegradable resin and reduce the water vapor transmission rate of a resin article having a substrate layer made of the biodegradable resin. On the other hand, according to one embodiment of the present invention, even if the surface roughness of the biodegradable resin increases, it is possible to produce a resin article having a substrate layer made of the biodegradable resin and having a barrier film with excellent water vapor transmission rate.

[0099] In the film formation process, the desired barrier film can be formed more efficiently by adjusting one or more conditions (one condition, two conditions, three conditions, or four conditions) selected from the group consisting of, for example, plasma intensity, amount of reactive gas (in other words, flow rate of reactive gas supplied into the film formation chamber), pressure in the film formation chamber, and film formation time.

[0100] The plasma intensity can be adjusted, for example, by adjusting the output of a power source (e.g., a radio frequency (RF) power source) that applies a voltage between an electrode (cathode) and an electrode (anode). The output of the power source is not limited and can be, for example, 50 W to 1000 W, 100 W to 500 W, or 300 W.

[0101] In this case, the distance between the electrode (cathode) and the electrode (anode) is not limited and may be, for example, 20 mm to 500 mm, 100 mm to 300 mm, or 180 mm.

[0102] The reactive gas is a mixed gas containing an organometallic compound gas and an oxidizing gas, so that when adjusting the amount of the reactive gas, it is possible to adjust the amount of the organometallic compound gas and / or the amount of the oxidizing gas.

[0103] The gas amount of the organometallic compound is not limited, and may be, for example, 1 sccm to 100 sccm, 5 sccm to 20 sccm, or 7 sccm.

[0104] The amount of the oxidizing gas is not limited, and may be, for example, 1 sccm to 1000 sccm, 10 sccm to 100 sccm, or 35 sccm.

[0105] The pressure in the deposition chamber is not limited and may be, for example, 0.1 Pa to 100.0 Pa, 0.2 Pa to 10.0 Pa, or 0.4 Pa to 4.0 Pa. The pressure in the deposition chamber can be adjusted by adjusting the amount of the reactive gas, for example.

[0106] The film formation time is not limited and may be, for example, 1 s to 1000 s, 10 s to 500 s, or 60 s to 180 s.

[0107] According to one embodiment of the present invention, a resin article can be provided that has a barrier film with excellent water vapor permeability and a substrate layer made of a biodegradable resin. Such an effect may contribute to the achievement of, for example, Goal 9 of the Sustainable Development Goals (SDGs) proposed by the United Nations, "Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote innovation and resilience."

[0108] One embodiment of the present invention may be any of the following <1> to <18>. <1> A resin article comprising a substrate layer containing a biodegradable resin and a barrier film on the surface of the substrate layer, wherein the surface roughness Ra1 of the barrier film is less than 0.300 μm, or, when the surface roughness of the substrate layer before the barrier film is formed is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1 - Ra0 < 0.200 μm. <2> The resin article according to <1>, wherein the biodegradable resin contains an aliphatic polyester resin and / or an aliphatic-aromatic polyester resin. <3> The resin article according to <1> or <2>, wherein the biodegradable resin contains a polyhydroxyalkanoate resin. <4> The resin article according to any one of <1> to <3>, wherein the surface roughness Ra1 of the barrier film is less than 0.150 μm, or, wherein the surface roughness Ra1 of the barrier film satisfies Ra1 - Ra0 < 0.100 μm. <5> The resin article according to any one of <1> to <4>, wherein the surface roughness Ra1 of the barrier film is less than 0.100 μm or satisfies Ra1 - Ra0 < 0.050 μm. <6> The resin article according to any one of <1> to <5>, wherein the surface roughness Ra1 of the barrier film is 0.010 μm or more. <7> The resin article according to any one of <1> to <6>, wherein the barrier film is formed by a plasma CVD method. <8> The resin article according to any one of <1> to <7>, wherein the barrier film contains SiCxOy and / or SiOz (wherein x, y, and z are each independently 0 to 2). <9> The resin article according to any one of <1> to <8>, wherein the thickness of the barrier film is less than 100 nm. <10> The resin article according to any one of <1> to <9>, wherein the barrier film has a thickness of less than 50 nm. <11> The resin article according to any one of <1> to <10>, wherein the barrier film is composed of a single layer. <12> The resin article according to any one of <1> to <11>, wherein the substrate layer containing a biodegradable resin has a thickness of 500 μm or less. <13> The resin article according to any one of <1> to <12>, wherein the substrate layer containing a biodegradable resin has a thickness of 100 μm or less. <14> The resin article according to any one of <1> to <12>, wherein the water vapor transmission rate of the resin article is 0.01 to 20.00 g / (m ２<15> A resin article according to any one of <1> to <13>, wherein the reaction time is 24 h). <15> A method for producing a resin article, comprising a film-forming step of supplying a reactive gas onto a substrate layer containing a biodegradable resin to form a barrier film on the surface of the substrate layer by plasma CVD, wherein the reactive gas is a mixed gas containing an organometallic compound gas and an oxidizing gas, and the surface roughness Ra1 of the barrier film is less than 0.300 μm, or when the surface roughness of the substrate layer before the barrier film formation is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1 - Ra0 < 0.200 μm. <16> The method according to <15>, wherein the organometallic compound is an organometallic compound containing an oxygen atom in the molecule. <17> The method according to <16>, wherein the organometallic compound containing an oxygen atom in the molecule is hexamethyldisiloxane. <18> The oxidizing gas is O ２ , CO ２ , or N ２ <15> to <17>, wherein O is O.

[0109] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0110] 1. Production of Resin Articles Resin articles were produced by plasma CVD using a vacuum film-forming apparatus UHSP-T2040H manufactured by Shimadzu Industrial Systems Corporation.

[0111] The raw material film (substrate layer) was set on a transfer table that also served as the vacuum chamber door and the anode, and then the transfer table was transferred into the vacuum chamber, and the vacuum chamber door was closed.Then, the vacuum chamber was evacuated to a pressure of 0.05 Pa or less using an exhaust pump.

[0112] Next, while supplying raw material gases, HMDSO (hexamethyldisiloxane) at a flow rate of 7 sccm and oxygen at a flow rate of 35 sccm, into the vacuum chamber, the aperture of the control valve was adjusted so that the pressure inside the vacuum chamber was kept at a predetermined value (e.g., 0.4 Pa, 1.0 Pa, 2.0 Pa, or 4.0 Pa).

[0113] Thereafter, plasma CVD film formation was carried out by supplying power to the cathode at an output of 300 W from a 13 MHz radio frequency (RF) power supply, and the film formation time was adjusted so that the barrier film formed on the surface of the raw material film had a predetermined film thickness (e.g., 20 nm or 60 nm).

[0114] The distance between the electrode (cathode) and the electrode (anode) was set to 180 mm.

[0115] [2. Film Thickness of Barrier Film] The film thickness of the barrier film was measured by X-ray reflectivity using a SmartLab 3kW X-ray diffractometer manufactured by Rigaku Corporation. Details of the measurement of the film thickness of the barrier film were in accordance with the protocol attached to the X-ray diffractometer and a known X-ray reflectivity method.

[0116] [3. Surface Roughness] Images of the raw material film and the obtained raw material film with a barrier film were obtained using a 3D measuring laser microscope manufactured by Evident Co., Ltd., and the arithmetic mean roughness (Ra0) of the surface of the raw material film and the arithmetic mean roughness (Ra1) of the surface of the obtained raw material film with a barrier film were calculated from the images. Details of the surface roughness measurement were in accordance with the protocol attached to the 3D measuring laser microscope.

[0117] 4. Water Vapor Transmission Rate The water vapor transmission rate of the raw material film with a barrier film was measured using a moisture permeation cup manufactured by Yasuda Seiki Seisakusho Co., Ltd. in accordance with JIS L1099A-1 method (calcium chloride method).

[0118] Specifically, a barrier film-coated raw material film was set in the evaluation device. The weight of water vapor that permeated the barrier film-coated raw material film was measured every day as the weight increase due to moisture absorption by calcium chloride (for each evaluation device). The water vapor transmission rate of the barrier film-coated raw material film was calculated from the area through which water vapor permeated the barrier film-coated raw material film (permeation area) and the rate of increase in the weight.

[0119] 5. Oxygen Permeability The oxygen permeability of the raw material film with a barrier film was measured using an oxygen permeability measuring device manufactured by Systec Illinois, Inc., in accordance with JIS K 7126-2.

[0120] [Example 1] A 25 µm thick biodegradable resin film (biodegradable resin: polyhydroxyalkanoate) containing an external lubricant (behenic acid amide) was used as the raw film, and a barrier film-attached raw film (resin article) was produced according to the above-mentioned [1. Production of resin article], with the pressure in the vacuum chamber set to 1.0 Pa, the film-forming time set to 60 seconds, and the thickness of the barrier film set to 20 nm.

[0121] Example 2 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 1, except that the pressure in the vacuum chamber was set to 2.0 Pa.

[0122] Example 3 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 1, except that the pressure in the vacuum chamber was set to 4.0 Pa.

[0123] Example 4 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 1, except that the film formation time was set to 180 seconds and the thickness of the barrier film was set to 60 nm.

[0124] Example 5 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 4, except that the pressure in the vacuum chamber was set to 1.0 Pa.

[0125] Example 6 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 4, except that the pressure in the vacuum chamber was set to 2.0 Pa.

[0126] Example 7 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 4, except that the pressure in the vacuum chamber was set to 4.0 Pa.

[0127] Example 8 A raw film with a barrier film (resin article) was produced in the same manner as in Example 1, except that a 400 μm thick biodegradable resin film (biodegradable resin: polyhydroxyalkanoate) containing an external lubricant (behenic acid amide) was used as the raw film and the pressure in the vacuum chamber was set to 0.4 Pa.

[0128] Comparative Example 1 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 1, except that the pressure in the vacuum chamber was set to 0.4 Pa.

[0129] Comparative Example 2 In Comparative Example 2, the arithmetic mean roughness (Ra), water vapor permeability, and oxygen permeability of a 25 μm thick biodegradable resin film (biodegradable resin: polyhydroxyalkanoate) itself were measured.

[0130] Comparative Example 3 In Comparative Example 3, the arithmetic mean roughness (Ra), water vapor permeability, and oxygen permeability of a 400 μm thick biodegradable resin film (biodegradable resin: polyhydroxyalkanoate) itself were measured.

[0131] Comparative Example 4 A raw material film (resin article) with a barrier film was produced in the same manner as in Example 1, except that a 25 μm thick PET film (Lumirror #25-S10) manufactured by Toray Industries, Inc. was used as the raw material film.

[0132] Comparative Example 5 In Comparative Example 5, the arithmetic mean roughness (Ra) and water vapor transmission rate of the PET film itself of Comparative Example 4 are shown.

[0133] Reference Example 1 The raw material film was plasma-treated using only oxygen under the same conditions as Comparative Example 1, except that HMDSO was not used as the raw material gas (in Reference Example 1, no barrier film was formed). The arithmetic mean roughness (Ra) of the raw material film was shown as Ra1.

[0134] [Reference Example 2] The raw material film was plasma-treated using only oxygen under the same conditions as Reference Example 1, except that the pressure in the vacuum chamber was set to 2.0 Pa (in Reference Example 2, no barrier film was formed). The arithmetic mean roughness (Ra) of the raw material film was shown as Ra1.

[0135] Reference Example 3 The same conditions as Reference Example 1 were used except that the raw material film was a PET film "Lumirror #25-S10" manufactured by Toray Industries, Inc., and the raw material film was plasma-treated using only oxygen (in Reference Example 3, no barrier film was formed). The arithmetic mean roughness (Ra) of the raw material film was shown as Ra1.

[0136] [Reference Example 4] The raw material film was plasma-treated using only oxygen under the same conditions as Reference Example 3, except that the pressure in the vacuum chamber was set to 2.0 Pa (in Reference Example 4, no barrier film was formed). The arithmetic mean roughness (Ra) of the raw material film was shown as Ra1.

[0137] The test results are shown in Tables 1 and 2 below.

[0138] From Tables 1 and 2, it can be seen that the resin articles according to the examples of the present invention are resin articles having a substrate layer made of a biodegradable resin and equipped with a barrier film having excellent water vapor permeability and oxygen permeability.

[0139] From Tables 1 and 2, the following can be understood in more detail:

[0140] For example, a comparison between Example 1 and Comparative Example 1 shows that adjusting the pressure (film-forming conditions) can suppress an increase in surface roughness and achieve a good water vapor permeability. Similarly, a comparison between Example 6 and Comparative Example 1 shows that a good oxygen permeability can also be achieved. If the pressure is increased too much, the adhesion between the barrier film and the raw material film may decrease, making it difficult to achieve a good water vapor permeability.

[0141] For example, a comparison between Example 4 and Comparative Example 1 shows that adjusting the thickness of the barrier film can suppress an increase in the surface roughness of the barrier film and achieve a good water vapor permeability. It is believed that setting the thickness of the barrier film to an appropriate thickness is effective in improving the surface roughness of the barrier film and the water vapor permeability of the resin article. On the other hand, a long film-forming time may reduce the productivity of the resin article, and an excessively thick barrier film may make it more susceptible to cracking, making it difficult to improve the water vapor permeability of the resin article.

[0142] For example, from a comparison between Example 8 and Comparative Example 3, it can be seen that even if the thickness of the substrate layer is increased, a similarly good water vapor permeability can be achieved.

[0143] For example, a comparison between Comparative Example 1 and Comparative Example 2 reveals that the surface roughness of the raw material film, which is a biodegradable resin, is impaired by the plasma.

[0144] For example, a comparison between Comparative Examples 4 and 5 reveals that the surface roughness of a PET film, which is not a biodegradable resin, is not impaired by plasma and a good water vapor transmission rate is obtained.

[0145] For example, a comparison of Comparative Example 2 with Reference Examples 1 and 2 reveals that the surface roughness of the biodegradable resin increases, particularly, due to plasma using oxygen (the oxygen radicals generated).

[0146] For example, a comparison of Comparative Example 4 with Reference Examples 3 and 4 shows that in the case of a PET film that is not a biodegradable resin, the surface roughness of the biodegradable resin does not increase even when oxygen-based plasma is used.

[0147] The present invention can be suitably used in the fields of agriculture, fisheries, forestry, horticulture, medicine, hygiene products, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

Claims

1. A resin article comprising a substrate layer containing a biodegradable resin and a barrier film on the surface of the substrate layer, wherein the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor permeability of the resin article is 0.01 to 20.00 g / (m ２ - 24h).

2. A resin article according to claim 1, wherein when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1-Ra0<0.200 μm.

3. The resin article according to claim 1, wherein the barrier film is formed by a plasma CVD method.

4. The resin article according to claim 1, wherein the barrier film contains SiCxOy and / or SiOz (wherein x, y, and z each independently represent an integer of 0 to 2).

5. The resin article according to claim 1, wherein the barrier film has a thickness of less than 100 nm.

6. The resin article according to claim 1, wherein the barrier film consists of a single layer.

7. The resin article according to claim 1, wherein the thickness of the substrate layer containing the biodegradable resin is 500 μm or less.

8. A resin article according to any one of claims 1 to 7, wherein the biodegradable resin comprises an aliphatic polyester resin and / or an aliphatic-aromatic polyester resin.

9. The resin article according to any one of claims 1 to 7, wherein the biodegradable resin comprises a polyhydroxyalkanoate resin.

10. A method for producing a resin article, comprising a film-forming step of supplying a reactive gas onto a substrate layer containing a biodegradable resin and forming a barrier film on the surface of the substrate layer by plasma CVD, wherein the reactive gas is a mixed gas containing an organometallic compound gas and an oxidizing gas, the surface roughness Ra1 of the barrier film is less than 0.300 μm, and the water vapor permeability of the resin article is 0.01 to 20.00 g / (m ２ 24h).

11. The manufacturing method according to claim 10, wherein, when the surface roughness of the substrate layer before the formation of the barrier film is Ra0, the surface roughness Ra1 of the barrier film satisfies Ra1-Ra0<0.200 μm.

12. The method of claim 10, wherein the organometallic compound contains an oxygen atom in the molecule.

13. The method according to claim 12, wherein the organometallic compound containing an oxygen atom in the molecule is hexamethyldisiloxane.

14. The oxidizing gas is O ２ , CO ２ , or N ２ The method according to any one of claims 10 to 13, wherein O is O.

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