JP7467454B2 - Molded body and its use - Google Patents

Description

The present invention relates to a molded body containing poly(3-hydroxyalkanoate) and its use.

Most plastic containers end up as solid waste. While efforts are being made to recycle them, repeated processing leads to a deterioration in their mechanical properties. Therefore, there is a demand for plastic containers that decompose in soil environments. One example of such a plastic product is one that uses biodegradable resins such as polylactic acid as its main component.

Meanwhile, environmental problems caused by discarded plastics have been brought into the spotlight, and it has become clear that large amounts of plastic, particularly plastic that has been dumped in the ocean or has flowed into the ocean via rivers, are drifting in the ocean on a global scale. Because such plastics retain their shape for long periods of time, they have been noted to have an impact on the ecosystem, including the fact that they can trap and capture marine organisms, a practice known as ghost fishing, and that if ingested by marine organisms, they can become trapped in the digestive tract and cause eating disorders.

Furthermore, there is also the problem that microplastics, which are plastics that break down and break down into small particles due to ultraviolet rays etc., adsorb harmful compounds in seawater and are ingested by marine organisms, resulting in harmful substances being introduced into the food chain. Among the plastic waste floating in the ocean, there is a large amount of film used for labels and food packaging, as well as bottle containers such as PET bottles, and this is considered problematic.

The use of biodegradable plastics is expected to combat marine pollution caused by such plastics, but a report compiled by the United Nations Environment Programme in 2015 (Non-Patent Document 1) points out that compostable plastics such as polylactic acid cannot be expected to decompose in a short period of time in the cold ocean, and therefore cannot be used as a countermeasure against marine pollution. On the other hand, however, the bottle containers themselves are particularly useful for carrying beverages and food, and continued use is desirable.

In this context, poly(3-hydroxybutyrate) resins are attracting attention as a material that can biodegrade even in seawater and thus solve the problem of marine pollution.

Since food packaging films and bottle containers are used to store beverages and food, they are required to have gas barrier properties and transparency. In order to improve the gas barrier properties of such biodegradable resins, it is widely known to manufacture gas barrier films by depositing metals or the like on the biodegradable resins. However, in general, the adhesion between biodegradable resins and deposition layers of metals or the like is poor. To solve this problem, for example, Patent Document 1 reports a technology in which an anchor coat layer made of a specific polyurethane resin composition is formed on a biodegradable resin film to improve adhesion with a deposition layer of metals or the like. Patent Document 2 also discloses a thermoplastic biodegradable polymer mixture containing starch as an essential component as a biodegradable substance.

International Publication No. 2012/039259 US2014/0087106

United Nations Environment Programme 2015, BIODEGRADABLE PLASTICS & MARINE LITTER

However, the technology of Patent Document 1 requires the formation of an anchor coat layer made of a non-biodegradable polyurethane resin composition, so there is room for improvement in terms of biodegradability. Also, the technology of Patent Document 2 has the problem that the transparency of the film is low, making it difficult to visually check the printed layer and contents.

Therefore, one aspect of the present invention aims to provide a molded body having excellent gas barrier properties and a highly transparent resin layer by improving the adhesion between a biodegradable resin layer using a poly(3-hydroxybutyrate)-based resin and a vapor deposition layer, and a technology for using the same.

As a result of intensive research conducted by the inventors to solve the above problems, they discovered new findings that (1) it is possible to improve adhesion between a biodegradable resin layer using a poly(3-hydroxybutyrate)-based resin, which is a material that biodegrades in seawater, and a vapor deposition layer, (2) the gas barrier properties of the resulting laminate are excellent, and (3) a resin layer with high transparency can be obtained, and thus completed the present invention.

Therefore, one aspect of the present invention is a molded body including a laminate having a vapor deposition layer containing an inorganic material on at least one side of a resin layer containing poly(3-hydroxyalkanoate), in which the vapor deposition layer is formed on a surface of the resin layer having a surface tension of 36 mN/m or more.

According to one aspect of the present invention, a molded body can be provided that has excellent adhesion to the deposition layer, good gas barrier properties, and high transparency of the resin layer.

An embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more, B or less." In addition, all documents described in this specification are incorporated herein by reference.

〔1. Overview〕
A molded article according to one embodiment of the present invention (hereinafter referred to as "the molded article") is a molded article including a laminate in which a vapor-deposited layer containing an inorganic material is provided on at least one side of a resin layer containing poly(3-hydroxyalkanoate), and is characterized in that the vapor-deposited layer is formed on a surface of the resin layer having a surface tension of 36 mN/m or more. In other words, it can be said to be a molded article including a laminate in which a layer containing an inorganic material is vapor-deposited on at least one side of a resin layer containing poly(3-hydroxyalkanoate), and in which the inorganic material is vapor-deposited on a surface of the resin layer having a surface tension of 36 mN/m or more.

As a result of extensive research into molded bodies containing poly(3-hydroxybutyrate)-based resins, the inventors have succeeded in obtaining the following findings:

In forming a molded article in which a metal or the like is vapor-deposited on a resin layer containing a poly(3-hydroxybutyrate)-based resin, it has been found that by setting the surface tension of the resin layer containing the poly(3-hydroxybutyrate)-based resin to 36 mN/m or more and vapor-depositing an inorganic material on the surface of the resin layer, the adhesion between the resin layer containing the poly(3-hydroxybutyrate)-based resin and the vapor-deposited layer (hereinafter sometimes referred to as "vapor deposition adhesion") is increased and the gas barrier properties of the molded article are improved. It has also been found that the transparency of the obtained resin layer is high. Details of the means for setting the surface tension of the resin layer to 36 mN/m or more will be described later, but one example is a method in which the resin layer does not substantially contain an external lubricant.

In previous research and development, molded articles containing poly(3-hydroxybutyrate)-based resins had a problem that the processable temperature range during inflation molding of a film was significantly narrower than that of general-purpose resins, resulting in poor moldability and productivity. In order to solve this problem, when molding poly(3-hydroxybutyrate)-based resins, it was usually necessary to add an external lubricant to ensure moldability and productivity (for example, WO 2018/181500).

Based on this common technical knowledge, when handling resins containing poly(3-hydroxybutyrate)-based resins, a person skilled in the art would naturally add an external lubricant to the mixture in the molding process, and would not think of intentionally removing the external lubricant from a molding mixture containing poly(3-hydroxybutyrate)-based resins. Therefore, the above findings obtained by the present inventors are surprising.

The present molded article has a configuration in which at least one side of a resin layer containing poly(3-hydroxyalkanoate) is provided with a vapor deposition layer containing an inorganic material, which has the effect of preventing the vapor deposition layer from peeling off, providing excellent gas barrier properties, and high transparency of the resin layer. In this specification, gas barrier properties refer to, for example, water vapor permeability and/or oxygen permeability. The configuration of the present molded article is described in detail below.

[2. Resin layer]
The resin layer in the present molded product contains poly(3-hydroxyalkanoate), which may hereinafter be abbreviated to P3HA.

Poly(3-hydroxyalkanoate) (P3HA)
In this specification, "P3HA" refers to a biodegradable aliphatic polyester (preferably a polyester not containing an aromatic ring). P3HA is a polyhydroxyalkanoate containing 3-hydroxyalkanoic acid repeating units represented by the general formula: [-CHR-CH ₂ -CO-O-] (wherein R is an alkyl group represented by C _n H _2n+1 , and n is an integer of 1 to 15) as an essential repeating unit. Among them, those containing 50 mol % or more of said repeating units relative to the total monomer repeating units (100 mol %) are preferred, and more preferably 70 mol % or more.

More specifically, 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), poly(3-hydroxybutyrate-co-3-hydroxydecanoate), and the like.

In addition, P3HA produced by microorganisms (microorganism-produced P3HA) is usually P3HA composed only of D-form (R-form) polyhydroxyalkanoic acid monomer units. Among the microbially produced P3HA, P3HB, P3HB3HH, P3HB3HV, P3HB3HV3HH, and P3HB4HB are preferred because of ease of industrial production, and P3HB, P3HB3HH, P3HB3HV, and P3HB4HB are more preferred.

In one embodiment of the present invention, P3HA is at least one selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).

When P3HA (particularly microbially produced P3HA) contains 3-hydroxybutanoic acid (3HB) repeat units as an essential monomer unit, the monomer composition ratio is preferably 80 mol% to 99 mol% of 3-hydroxybutanoic acid (3HB) repeat units in all repeat units (100 mol%), more preferably 85 mol% to 97 mol%, from the viewpoint of the balance between flexibility and strength. 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, so that purification tends to be easy. On the other hand, when the composition ratio of 3HB repeat units is 99 mol% or less, the flexibility tends to be further improved. The monomer composition ratio of P3HA can be measured by gas chromatography or the like (see, for example, International Publication No. WO 2014/020838).

Microorganisms that produce microbially produced P3HA are not particularly limited as long as they are capable of producing P3HAs. For example, the first P3HB-producing bacterium was Bacillus megaterium, discovered in 1925, and other natural microorganisms include Cupriavidus necator (formerly classified as Alcaligenes eutrophus, Ralstonia eutropha) and Alcaligenes latus. It is known that P3HB accumulates in the cells of these microorganisms.

In addition, known 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, p4821-4830 (1997)) into which genes of P3HA synthesis enzyme group have been introduced is more preferred, and microbial cells in which P3HB3HH has been accumulated in the cells by culturing these microorganisms under appropriate conditions are used. In addition to the above, genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used according to the P3HA to be produced, or the culture conditions, including the type of substrate, may be optimized.

The molecular weight of P3HA is not particularly limited as long as it exhibits substantially sufficient physical properties for the intended use. The weight average molecular weight of P3HA is 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 film tends to be improved. On the other hand, by setting the weight average molecular weight to 3,000,000 or less, the processability tends to be improved and molding tends to be easier. As described later, it is preferable that the P3HA is a uniformly and appropriately crosslinked P3HA, but the value of the weight average molecular weight is a value measured before crosslinking the P3HA.

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

In one embodiment of the present invention, P3HA may be used alone or in combination of two or more types.

In one embodiment of the present invention, the content of P3HA in the resin layer is not particularly limited, but is preferably 20% by weight or more, more preferably 30% by weight or more, even more preferably 40% by weight or more, even more preferably 60% by weight or more, and even more preferably 70% by weight or more. By making the content of P3HA 20% by weight or more, the biodegradability of the resin layer tends to be even better. The upper limit of the content of P3HA is not particularly limited, but is preferably 95% by weight or less, more preferably 92% by weight or less, and even more preferably 90% by weight or less.

In the present molded product, the surface tension of at least one side of the molded product before deposition is preferably 36 mN/m or more, more preferably 37 mN/m or more, and particularly preferably 38 mN/m or more. By providing a deposition layer on a surface with a surface tension of 36 mN/m or more, the gas barrier property and the adhesion between the deposition layer and the resin layer tend to be excellent. The method of making the surface tension 36 mN/m or more is not particularly limited as long as the surface tension can be made 36 mN/m or more, but preferably used are a method that does not substantially use an external lubricant, a discharge treatment such as a corona treatment or a plasma treatment, a method of washing the surface with a liquid, a method of roughening the surface, etc.

In addition, in the present molded product, the surface friction coefficient of at least one side of the molded product before deposition is preferably 0.17 or more, more preferably 0.18 or more, and particularly preferably 0.19 or more. By providing a deposition layer on a surface with a surface friction coefficient of 0.17 or more, the gas barrier property and the adhesion between the deposition layer and the resin layer tend to be excellent. The method of making the surface friction coefficient 0.17 or more is not particularly limited as long as the surface friction coefficient can be made 0.17 or more, but preferably used are a method that does not substantially use an external lubricant, a discharge treatment such as a corona treatment or a plasma treatment, a method of cleaning the surface with a liquid, a method of smoothing the surface, etc.

(External Lubricant)
The resin layer in the present molded article is preferably substantially free of an external lubricant. Since the resin layer is substantially free of an external lubricant, when a vapor deposition layer containing an inorganic material is vapor-deposited on the resin layer, the adhesiveness between the resin layer and the vapor deposition layer is increased. In addition, the molded article has high gas barrier properties.

In this specification, "external lubricant" means a substance that bleeds onto the surface of a molded body and promotes peeling from the rolls or mold of the molding machine, 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 thereof include fatty acid monoamides and fatty acid bisamides. Examples of fatty acids that constitute fatty acid amides include fatty acids with 12 to 30 carbon atoms or fatty acids with 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 bis stearic acid amide, ethylene bis stearic acid amide, ethylene bis oleic acid amide, and ethylene bis erucic acid amide.

In this specification, "substantially free of external lubricants" means that the resin layer does not contain external lubricants to an extent that would affect the effects of the present invention. In other words, "substantially free of external lubricants" means that the resin layer may contain external lubricants to an extent that would not affect the effects of the present invention.

In one embodiment of the present invention, the content of the external lubricant in the resin layer is preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and even more preferably 0.1% by weight or less. It is most preferable that the resin layer does not contain any external lubricant. When the content of the external lubricant in the resin layer is 0.5% by weight or less, high adhesion with the deposition layer is ensured, and high gas barrier properties are achieved.

(Crystal nucleating agent)
The resin layer in the present molded product may contain a crystal nucleating agent. By containing a crystal nucleating agent in the resin layer in the present molded product, the crystallization rate of P3HA is improved, and the moldability can be improved. As the crystal nucleating agent, for example, polyhydric alcohols and the like are preferably used. Examples of polyhydric alcohols include pentaerythritol, galactitol, mannitol, and the like. The crystal nucleating agent can be used alone or in combination of two or more kinds. The content of the crystal nucleating agent can be appropriately set and is not particularly limited.

(Other resins)
The resin layer in the present molded body may contain a resin other than P3HA (hereinafter, sometimes referred to as "other resin"). The other resin is not particularly limited as long as it does not significantly reduce compatibility, moldability, or mechanical properties when molding the molded body in one embodiment of the present invention, but when the present molded body is used for an application requiring biodegradability, which is a characteristic of P3HA, it is preferable that the resin is a biodegradable resin. Examples of the other resin include aliphatic polyesters having a structure in which aliphatic diols and aliphatic dicarboxylic acids are polycondensed, and aliphatic aromatic polyesters having both aliphatic compounds and aromatic compounds as monomers. Examples of the former include polyethylene succinate, polybutylene succinate (PBS), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (PBSA), polyethylene sebacate, polybutylene sebacate, etc. Examples of the latter include poly(butylene adipate-co-butylene terephthalate) (PBAT), poly(butylene sebacate-co-butylene terephthalate), poly(butylene azelate-co-butylene terephthalate), poly(butylene succinate-co-butylene terephthalate) (PBST), etc. The other resins may be used alone or in combination of two or more.

In one embodiment of the present invention, the content of other resins in the resin layer is not particularly limited, but is preferably 250 parts by weight or less, more preferably 100 parts by weight or less, even more preferably 50 parts by weight or less, and particularly preferably 20 parts by weight or less, relative to 100 parts by weight of P3HA. The lower limit of the content of other resins is not particularly limited, and may be 0 parts by weight.

(Other ingredients)
The resin layer in the present molded body may contain other components other than those described above. For example, organic or inorganic fillers may be contained within a range that does not impair the effects of the present invention. Among them, from the viewpoint of biodegradability and carbon neutrality of the obtained film, for example, wood-based materials such as wood chips, wood flour, and sawdust, and naturally derived materials such as rice husks, rice flour, starch, corn starch, rice straw, wheat straw, and natural rubber are preferred. The content of the organic or inorganic filler can be appropriately set and is not particularly limited. The organic or inorganic filler can be used alone or in combination of two or more types. In addition to the above-mentioned organic or inorganic fillers, the resin layer may contain one or more of colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolite, fragrances such as vanillin and dextrin, antioxidants, antioxidants, weather resistance improvers, ultraviolet absorbers, water repellents, antibacterial agents, sliding improvers, and other secondary additives that are commonly used within a range that does not impair the effects of the present invention. The content of the additive can also be appropriately set.

[3. Deposition layer]
The vapor-deposited layer in the present molded product may contain an inorganic material, but may also be composed of only an inorganic material.

In one embodiment of the present invention, the inorganic material is not particularly limited, and may be, for example, a metal or an inorganic oxide. Preferred examples include aluminum, aluminum oxide, silicon oxide (e.g., silicon monoxide, silicon dioxide, silicon oxynitride, etc.), cerium oxide, calcium oxide, diamond-like carbon film, or a mixture thereof. In one embodiment of the present invention, the inorganic material is preferably aluminum or silicon dioxide from the viewpoint of deposition adhesion.

The thickness of the deposition layer is not particularly limited, but from the viewpoints of productivity, handling, appearance, etc., it is preferably 5 nm to 100 nm, and more preferably 5 nm to 60 nm. When the thickness of the deposition layer is 5 nm or more, defects in the deposition layer (peeling of the deposition layer from the resin layer) are unlikely to occur, and the gas barrier properties are good. In addition, when the layer thickness is less than 100 nm, the cost of deposition is low, the coloring of the deposition layer is not noticeable, and the appearance is good.

4. Specific configuration of molded body and manufacturing method thereof
(Configuration of Molded Body)
In the present molded product, the vapor-deposited layer may be vapor-deposited on only one side of the resin layer, or on both sides. From the viewpoint of ensuring the biodegradability of P3HA, it is preferable that the vapor-deposited layer is vapor-deposited on only one side of the resin layer. It is also preferable that the vapor-deposited layer is vapor-deposited directly on the resin layer without any other layer.

In one embodiment of the present invention, the vapor deposition layer in the molded product may be further laminated with a resin layer or the like. For example, when the molded product is to be heat sealed, a resin layer may be further laminated on the vapor deposition layer.

The present molded article is not particularly limited as long as it has a configuration in which a vapor-deposited layer containing an inorganic material is vapor-deposited on at least one side of a resin layer containing poly(3-hydroxyalkanoate), but examples include paper, film, sheet, tube, plate, rod, container (e.g., bottle container), bag, part, etc. From the viewpoint of marine pollution countermeasures, the present molded article is preferably a film or bottle container.

In one embodiment of the present invention, the haze value of the resin layer in this molded product is, for example, 40% or less, preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, particularly preferably 20% or less, and even more preferably 10% or less. If the haze value of the resin layer is 40% or less, the transparency of the resin layer is good, and there is an advantage that the visibility of the contents is excellent when used as a packaging material. The lower limit of the haze value of the resin layer is the better from the viewpoint of transparency, and is not particularly limited, but is, for example, 1% or more. In this specification, the haze value is a value measured by the method described in JIS K7136-1:1999 and K7316:2000 for a sheet (film) having a thickness of 30 μm.

A film (resin layer) with a haze value of 40% or less can be obtained by increasing the resin temperature inside the extruder to a level that does not cause surface roughness when the resin is extruded from the extruder outlet when forming the resin layer, by not blending a certain amount of resin with a high haze value (for example, a resin with a haze value of 40% or more at a thickness of 30 μm), or by not blending a certain amount of filler that increases the haze value.

The water vapor permeability of the present molded body is, for example, less than 1.00 g/m ² /24h, preferably less than 0.95 g/m ² /24h, more preferably less than 0.90 g/m ² /24h, and even more preferably less than 0.85 g/m ² /24h. If the water vapor permeability is within the above range, good water vapor gas barrier properties can be obtained. In addition, the lower the water vapor permeability, the better, and the lower limit is not particularly limited, but it is presumed that about 0.01 g/m ² /24h is the realizable lower limit. The water vapor permeability can be controlled by the average surface roughness of the layer on which the deposition layer is formed, the fn of the film, the type of inorganic material of the deposition layer, the thickness of the deposition layer, the amount of defects (pinholes, scratches, etc.) of the deposition layer, etc. In addition, the water vapor permeability is measured and evaluated by the method described in the examples.

The oxygen permeability of the present molded body is, for example, 3.00 g/m ² /24 h/atm or less, preferably 2.85 g/m ² /24 h/atm or less, more preferably 2.80 g/m ² /24 h/atm or less, and even more preferably 2.75 g/m ² /24 h/atm or less. If the oxygen permeability is within the above range, good oxygen gas barrier properties can be obtained. In addition, the lower the oxygen permeability, the better, and the lower limit is not particularly limited, but it is presumed that about 0.01 g/m ² /24 h/atm is the achievable lower limit. The oxygen permeability can be controlled by the average surface roughness of the layer on which the deposition layer is formed, the fn of the film, the type of inorganic material of the deposition layer, the thickness of the deposition layer, the amount of defects (pinholes, scratches, etc.) of the deposition layer, etc. The oxygen permeability is measured and evaluated by the method described in the examples.

The deposition adhesion of this molded body is measured and evaluated using the method described in the examples.

In one embodiment of the present invention, the molded article can be composited with a molded article made of a material different from the molded article (e.g., fiber, thread, rope, woven fabric, knitted fabric, nonwoven fabric, paper, film, sheet, tube, plate, rod, container, bag, part, foam, etc.) in order to improve its physical properties. These materials are also preferably biodegradable.

In one embodiment of the present invention, the vapor-deposited film can be used as a packaging material for various packages. The packages include, but are not limited to, side-seal packages, three-sided seal packages, pillow packages, standing pouches, etc.

(Example of manufacturing method)
When the present molded article is a vapor-deposited film or a vapor-deposited bottle container, it is produced, for example, by the method described below.

<Film manufacturing method>
In one embodiment of the present invention, the film can be produced by a molding method consisting of extrusion film molding. For example, the film can be produced by a process in which a poly(3-hydroxybutyrate)-based resin is melted in an extruder, extruded into a film shape from a T-die connected to the outlet of the extruder, and the molten resin is cooled and solidified by hitting it against a roll, and then taken up as a film. Specific conditions for extrusion film molding can be appropriately set by a person skilled in the art according to conventional methods.

<Bottle container manufacturing method>
In one embodiment of the present invention, the bottle container can be manufactured by a molding method comprising extrusion blow molding. For example, the bottle container can be manufactured by a process comprising the steps of melting a poly(3-hydroxybutyrate)-based resin in an extruder, extruding the resin into a tube shape from a circular die connected to the outlet of the extruder, sandwiching the molten tube from both sides with a mold, blowing air into the tube with one end closed to mold it into a bottle shape according to the mold, and simultaneously cooling and solidifying the tube. Specific conditions for extrusion blow molding can be appropriately set by a person skilled in the art according to conventional methods. The bottle container can also be manufactured by a molding method comprising injection blow molding.

<Vacuum deposition>
In one embodiment of the present invention, the vapor-deposited film and the vapor-deposited bottle container are produced by depositing the vapor-deposited layer on the film and the bottle container obtained above. The vapor-deposition method is not particularly limited, and may be a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, an ion plating method, or the like.

In order to improve the gas barrier properties of the molded body, it is preferable to subject the surface of the molded body before deposition to a corona treatment or plasma treatment. The treatment intensity when performing the corona treatment is preferably 5 to 80 W·min/ ^m2 , more preferably 10 to 60 W·min/ ^m2 . In addition, it is preferable to provide a nucleated metal deposition layer under plasma discharge before providing a deposition layer, from the viewpoint of improving the adhesion of the deposition layer and thus the gas barrier properties. In this case, it is preferable to perform the plasma discharge in an oxygen and/or nitrogen gas atmosphere, and it is preferable to use copper as the nucleated metal.

In order to deposit aluminum oxide by reactive deposition, a method is preferably used in which aluminum metal or alumina is evaporated by a resistance heating boat method, high-frequency induction heating of a crucible, electron beam heating method, or the like, and aluminum oxide is deposited on a film under an oxidizing atmosphere. Oxygen is used as a reactive gas for forming the oxidizing atmosphere, but a gas mainly composed of oxygen and water vapor or a rare gas may also be used. Furthermore, ozone may be added, or a method for promoting the reaction such as ion assist may be used in combination. In order to form a silicon oxide deposition layer by reactive deposition, a method is adopted in which Si metal, SiO or _SiO2 is evaporated by an electron beam heating method, and silicon oxide is deposited on a film under an oxidizing atmosphere. The same method as above is used to form the oxidizing atmosphere.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

That is, one embodiment of the present invention is as follows.
<1> A molded article including a laminate having a vapor-deposited layer containing an inorganic material provided on at least one side of a resin layer containing poly(3-hydroxyalkanoate), wherein the vapor-deposited layer is formed on a surface of the resin layer having a surface tension of 36 mN/m or more.
<2> The molded article according to <1>, wherein the resin layer is substantially free of an external lubricant.
<3> The molded body according to <1> or <2>, wherein the resin layer has a haze value of 40% or less.
<4> The molded body according to any one of <1> to <3>, wherein the inorganic material is at least one selected from the group consisting of aluminum, aluminum oxide, silicon oxide, cerium oxide, calcium oxide, diamond-like carbon film, and mixtures thereof.
<5> The molded article according to any one of <1> to <4>, which has a water vapor permeability of less than 1.00 g/m ² /24 h.
<6> The molded article according to any one of <1> to <5>, wherein the poly(3-hydroxyalkanoate) is at least one selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).
<7> The molded article according to any one of <1> to <6>, which is a vapor deposition film or a vapor deposition bottle container.

The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

〔material〕
The following materials were used in the examples and comparative examples.

(P3HA)
A-1: Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH) obtained according to the method described in WO 2013/147139, having a 3-hydroxyhexanoate (3HH) composition of 11.2 mol% and a weight average molecular weight of 580,000 in terms of standard polystyrene measured by GPC.
A-2: P3HB3HH obtained according to the method described in WO 2008/010296, having a 3HH composition of 5.4 mol% and a weight average molecular weight of 620,000 in terms of standard polystyrene measured by GPC
A-3: Ecomann EM5400F [Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB)]
PBAT/Starch: A mixture obtained according to the method described in US 2014/0087106, which has a PBAT (poly(butylene adipate-co-butylene terephthalate)) composition of 75% by weight and a potato-derived natural starch composition of 25% by weight.

(External Lubricant)
B-1: Erucic acid amide (manufactured by Nippon Fine Chemicals)
(Crystal nucleating agent)
C-1: Pentaerythritol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
(Inorganic Materials)
D-1: Aluminum (manufactured by Kojundo Chemical Laboratory)
D-2: Silicon dioxide (manufactured by Optoscience)
[Measurement and evaluation methods]
The evaluations in the examples and comparative examples were carried out by the following methods.

(Water vapor permeability)
The water vapor permeability was measured using PERMATRAN-W3/33MG+ manufactured by MOCON Co., Ltd. The measurement was performed under the following conditions: permeation cell temperature: 38° C., relative humidity: 90%, test gas: nitrogen, permeation area: 50 cm ² , and number of test sheets: 1.

(Oxygen permeability)
The oxygen transmission rate was measured using OX-TRAN ML2/21 manufactured by MOCON Co., Ltd. The measurement was performed under the following conditions: temperature 23° C., humidity 50% RH, test gas 100% oxygen, transmission area 5 cm ² , and number of test sheets 1.

(Vapor deposition adhesion)
Cellophane tape was applied to the surface of the laminate (deposited film) and immediately peeled off, and the evaluation was made as follows: if the deposited film did not peel off, it was marked as O; if it peeled off, it was marked as X. This measurement was performed three times, and if it peeled off even once, it was marked as X.

(surface tension)
Using a cotton swab, the surface tension test mixture manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was quickly spread over an area of ⁶ cm2 or more, and if the applied state was maintained for 2 seconds or more, it was evaluated as O, and if not, it was evaluated as X. Starting with a test mixture of 50 mN/m, the surface tension of the test mixture that was O was recorded as a numerical value.

(Haze value)
The haze value of a 30 μm-thick film (resin layer) was measured using a haze meter HZ-V3 manufactured by Suga Test Instruments according to the method described in JIS K7136-1:1999 and K7316:2000.

Example 1
P3HA (A-1), external lubricant (B-1), and crystal nucleating agent (C-1) were dry blended in the compounding ratio shown in Table 1. The resulting mixture was charged into a co-rotating intermeshing twin screw extruder (TEM26ss, manufactured by Toshiba Machine Co., Ltd.), melt-kneaded at a set temperature of 120 to 160° C. and a screw rotation speed of 100 rpm, and strand-cut to obtain pellets.

Using the obtained pellets, a film (sheet) was produced by T-die molding under initial conditions of an extruder temperature setting of 130-160°C, adapter and die temperature (resin temperature) setting of 160°C, and a take-up speed of 1 m/min. The extrusion conditions were a screw rotation speed of 30 rpm and a die gap of 250 um. After extrusion, the sheet was taken up at 1 m/min while a roll adjusted to 60°C was applied to it, producing a film (resin layer). The haze value of the obtained film was then measured. The results are shown in Table 1.

In addition, the inorganic material (D-1) was vacuum-deposited on the above film to obtain a laminate. The water vapor permeability, oxygen permeability, and deposition adhesion of the laminate were then measured and evaluated by the above-mentioned methods. The results are shown in Table 1.

Example 2
Films and laminates were produced in the same manner as in Example 1, except that the type of inorganic material was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3
Except for the absence of the crystal nucleating agent, a film and a laminate were produced in the same manner as in Example 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4
Films and laminates were produced in the same manner as in Example 1, except that the nucleating agent was removed and the type of inorganic material was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 5
Films and laminates were produced in the same manner as in Example 1, except that the type of P3HA was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 6
Films and laminates were produced in the same manner as in Example 1, except that the type of P3HA and the type of inorganic material were changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 7
A film and a laminate were produced in the same manner as in Example 1, except that the crystal nucleating agent was removed and the type of P3HA was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 8
A film and a laminate were produced in the same manner as in Example 1, except that the nucleating agent was removed and the type of P3HA and the type of inorganic material were changed as shown in Table 1. In addition, the haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 9
Films and laminates were produced in the same manner as in Example 1, except that the type of P3HA was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 10
Films and laminates were produced in the same manner as in Example 1, except that the type of P3HA and the type of inorganic material were changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 11
A film and a laminate were produced in the same manner as in Example 1, except that the crystal nucleating agent was removed and the type of P3HA was changed as shown in Table 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 12
A film and a laminate were produced in the same manner as in Example 1, except that the nucleating agent was removed and the type of P3HA and the type of inorganic material were changed as shown in Table 1. In addition, the haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

〔比較例１〕
結晶核剤を除き、真空蒸着を行わなかったこと以外は、実施例１と同様にして、フィルムを製造した。また、実施例１と同様の方法により、得られたフィルムのヘイズ値、水蒸気透過度および酸素透過度を測定した。結果を表２に示す。

Comparative Example 1
Except for the absence of the crystal nucleating agent and the absence of vacuum deposition, a film was produced in the same manner as in Example 1. The haze value, water vapor permeability, and oxygen permeability of the obtained film were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2
Except for the elimination of the crystal nucleating agent, the type of P3HA was changed as shown in Table 2, and vacuum deposition was not performed, films were produced in the same manner as in Example 1. The haze value, water vapor permeability, and oxygen permeability of the obtained films were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3
Except for the elimination of the crystal nucleating agent, the type of P3HA was changed as shown in Table 2, and vacuum deposition was not performed, films were produced in the same manner as in Example 1. The haze value, water vapor permeability, and oxygen permeability of the obtained films were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 4
Except for adding an external lubricant, a film and a laminate were produced in the same manner as in Example 1. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 5
Films and laminates were produced in the same manner as in Example 1, except that an external lubricant was added, the crystal nucleating agent was removed, and the type of inorganic material was changed as shown in Table 2. The haze value of the obtained film, and the water vapor permeability, oxygen permeability, and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 6
Films and laminates were produced in the same manner as in Example 1, except that an external lubricant was added and the type of P3HA was changed as shown in Table 2. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 7
A film and a laminate were produced in the same manner as in Example 1, except that an external lubricant was added, the crystal nucleating agent was removed, and the type of P3HA and the type of inorganic material were changed as shown in Table 2. In addition, the haze value of the obtained film, and the water vapor permeability, oxygen permeability, and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 8
Films and laminates were produced in the same manner as in Example 1, except that an external lubricant was added and the type of P3HA was changed as shown in Table 2. The haze value of the obtained film, and the water vapor permeability, oxygen permeability and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 9
A film and a laminate were produced in the same manner as in Example 1, except that an external lubricant was added, the crystal nucleating agent was removed, and the type of P3HA and the type of inorganic material were changed as shown in Table 2. In addition, the haze value of the obtained film, and the water vapor permeability, oxygen permeability, and deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 10
Except for removing the crystal nucleating agent and changing P3HA to PBAT/Starch, a film and a laminate were produced in the same manner as in Example 1. In addition, the haze value of the obtained film and the deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 11
A film and a laminate were produced in the same manner as in Example 1, except that the crystal nucleating agent was removed, P3HA was changed to PBAT/Starch, and the type of inorganic material was changed as shown in Table 2. The haze value of the obtained film and the deposition adhesion of the obtained laminate were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

〔結果〕
表１および２より、実施例では、比較例に比して、積層体の水蒸気透過度および酸素透過度が低い結果となった。また、すべての実施例において、蒸着密着性および樹脂層のヘイズ値が良好な結果となった。

〔result〕
As can be seen from Tables 1 and 2, the laminates of the Examples had lower water vapor permeability and oxygen permeability than the Comparative Examples. In addition, the deposition adhesion and the haze value of the resin layer were good in all the Examples.

From the above, it was found that the molded body (laminate) of the present invention is a molded body in which the vapor deposition layer is resistant to peeling, has excellent gas barrier properties, and the resin layer has high transparency.

The molded body can be suitably used in agriculture, fishing, forestry, horticulture, medicine, hygiene products, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

Claims (6)

A molded article including a laminate having a vapor-deposited layer containing an inorganic material provided on at least one side of a resin layer containing poly(3-hydroxyalkanoate) and having a haze value of 40% or less , wherein the vapor-deposited layer is formed on a surface of the resin layer having a surface tension of 36 mN/m or more. The molded article according to claim 1, wherein the resin layer is substantially free of an external lubricant. 3. The molded body according to claim 1 , wherein the inorganic material is at least one selected from the group consisting of aluminum, aluminum oxide, silicon oxide, cerium oxide, calcium oxide, diamond-like carbon film, and mixtures thereof. The molded article according to any one of claims 1 to 3 , which has a water vapor permeability of less than 1.00 g/m ² /24 h. The molded article according to any one of claims 1 to 4, wherein the poly(3-hydroxyalkanoate) is at least one selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co- 4 -hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) and poly(3-hydroxybutyrate-co-3-hydroxydecanoate). The molded article according to any one of claims 1 to 5 , which is a vapor deposition film or a vapor deposition bottle container.