Film and molded body

Abstract

This film comprises a poly(3-hydroxyalkanoate)-based resin component containing a copolymer (A) which is formed of a 3-hydroxybutyrate unit and another hydroxyalkanoate unit and in which the content proportion of the 3-hydroxybutyrate unit is 76-90 mol%. The average content proportion of the 3-hydroxybutyrate unit in all monomer units forming the poly(3-hydroxyalkanoate)-based resin component is 86.0 mol% or less. The arithmetic mean curvature (Spc) of a peak measured for at least one surface of the film is 450 mm-1 or more.

Description

Films and molded articles 【0001】 The present invention relates to a film containing a poly(3-hydroxyalkanoate) resin, and a molded article containing the film. 【0002】 Large quantities of petroleum-derived plastics are discarded every year, and the environmental pollution caused by this massive amount of waste is a serious problem. In recent years, microplastics have also become a major problem in the marine environment. 【0003】 Poly(3-hydroxyalkanoate) resins possess excellent biodegradability in seawater and are materials that can solve environmental problems caused by discarded plastics. For example, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), a type of poly(3-hydroxyalkanoate) resin, allows for flexible control of its mechanical properties by changing the composition ratio of 3-hydroxyhexanoate. 【0004】 The use of poly(3-hydroxyalkanoate) resins as resin materials for various molded articles is being considered. For example, Patent Document 1 discloses an inflation film containing a poly(3-hydroxyalkanoate) resin having a specific composition and a plasticizer, and states that the molded article has good heat sealability. 【0005】 Japanese Patent Publication No. 2024-47854 【0006】 The present inventors investigated manufacturing gloves by bonding two films described in Patent Document 1 together using heat sealing, but found that the resulting gloves lacked sufficient strength. This is thought to be due to several factors: the extremely narrow width of the heat-sealed portion of the glove makes it difficult to ensure sufficient heat-seal strength; and the presence of areas with high curvature, such as between the thumb and index finger, causes stress to concentrate in these areas, making them prone to tearing. Furthermore, it was found that even when gloves were manufactured from the same constituent materials, the strength was not consistent, and sufficient strength could not always be achieved. Patent Document 1 did not address these points, indicating room for improvement. 【0007】In view of the above, the present invention aims to provide a film containing a poly(3-hydroxyalkanoate) resin that can improve the strength of a molded article formed by heat sealing the film. 【0008】 The inventors of the present invention have diligently studied to solve the above problems and have found that the problems can be solved by configuring the poly(3-hydroxyalkanoate) resin component constituting the film to include a specific copolymer and have a specific monomer composition, and by controlling at least one of the film surfaces to exhibit a roughness above a specific value, thereby completing the present invention. 【0009】 In other words, the present invention relates to a film containing a poly(3-hydroxyalkanoate) resin component, wherein the poly(3-hydroxyalkanoate) resin component comprises a copolymer (A) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is 76 mol% or more and 90 mol% or less, the average content of 3-hydroxybutyrate units in the total monomer units constituting the poly(3-hydroxyalkanoate) resin component is 86.0 mol% or less, and the arithmetic mean curvature (Spc) of the peak measured on at least one face of the film is 450 mm. －１ The above relates to films. The present invention also relates to molded articles containing the aforementioned films. 【0010】 According to the present invention, it is possible to provide a film containing a poly(3-hydroxyalkanoate) resin that can improve the strength of a molded article formed by heat-sealing the film. 【0011】 Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and various modifications are possible within the scope defined in the claims. Furthermore, the configurations described below can be combined arbitrarily, and such combinations may also constitute an embodiment of the present invention. 【0012】This embodiment relates to a film containing a poly(3-hydroxyalkanoate) resin component. 【0013】 (Poly(3-hydroxyalkanoate) resin component) The poly(3-hydroxyalkanoate) resin (hereinafter sometimes referred to as "P3HA resin") is a biodegradable aliphatic polyester (polyester that does not contain aromatic rings), and its general formula is: [-CHR-CH ２ 3-hydroxyalkanoic acid repeating unit represented by -CO-O-] (where R is C ｎ H ２ｎ＋１ The polyhydroxyalkanoate contains an alkyl group represented by , where n is an integer between 1 and 15. In particular, it is preferable that the repeating unit is contained in an amount of 50 mol% or more relative to the total monomer repeating units (100 mol%), and more preferably 70 mol% or more. 【0014】 Among P3HA resins, poly(3-hydroxybutyrate) resins are particularly readily available and easy to process, making them a preferred choice. 【0015】 The aforementioned poly(3-hydroxybutyrate) resin (hereinafter sometimes referred to as "P3HB resin") is a polyester resin containing 3-hydroxybutyrate as a repeating unit. The P3HB resin may be a poly(3-hydroxybutyrate) in which only 3-hydroxybutyrate is used as the repeating unit, or it may be a copolymer of 3-hydroxybutyrate and other hydroxyalkanoates. Furthermore, the P3HB resin may be a mixture of a homopolymer and one or more copolymers, or a mixture of two or more copolymers. 【0016】 The other hydroxyalkanoate units may be 3-hydroxyalkanoate units other than 3HB units, or hydroxyalkanoate units other than 3-hydroxyalkanoate units (for example, 4-hydroxyalkanoate units). The other hydroxyalkanoate units may consist of only one type, or two or more types. 【0017】Specific examples of the P3HB resins mentioned above include poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter sometimes referred to as "P3HB3HH"), poly(3-hydroxybutyrate-co-3-hydroxyvariate) (hereinafter sometimes referred to as "P3HB3HV"), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate). Among these, poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvariate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) are preferred because they are easy to produce industrially. 【0018】 Furthermore, by changing the composition ratio of repeating units, the melting point and degree of crystallinity can be altered, thereby changing physical properties such as Young's modulus and heat resistance, making it possible to impart properties between those of polypropylene and polyethylene. In addition, P3HB3HH is preferred from the viewpoint of being easy to produce industrially and being a physically useful plastic. In particular, among P3HB resins, which have the characteristic of being easily thermally decomposed when heated above 180°C, P3HB3HH is preferred from the viewpoint that its melting point can be lowered, enabling molding and processing at low temperatures. 【0019】 Examples of commercially available P3HB3HH products include Kaneka Corporation's "Kaneka Biodegradable Polymer Green Planet" (registered trademark). 【0020】 All resins included in the film according to this embodiment that conform to the definition of a P3HA-based resin are collectively referred to as P3HA-based resin components. 【0021】In the film according to this embodiment, the average content of 3-hydroxybutyrate units in the total monomer units constituting the P3HA resin component is set to 86.0 mol% or less. This makes it possible to impart flexibility to the film while maintaining the productivity of the film, and makes the molded article made from the film less prone to tearing. The average content is preferably 85.9% or less, preferably 85.7% or less, and more preferably 85.5% or less. 【0022】 The lower limit of the average content ratio of 3-hydroxybutyrate units to the total monomer units constituting the P3HA-based resin component is preferably 75.0 mol% or more, more preferably 80.0 mol% or more, even more preferably 84.0 mol% or more, and particularly preferably 85.0 mol% or more, from the viewpoint of film productivity and heat seal strength. 【0023】 The average content of monomer units in the P3HA resin component can be determined by methods known to those skilled in the art, for example, by the method described in paragraph

[0047] of International Publication 2013 / 147139. 【0024】 The poly(3-hydroxyalkanoate) resin component includes a copolymer (A) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is at least 76 mol% to 90 mol%. By including such a copolymer (A), flexibility can be imparted to the film while maintaining the productivity of the film, and molded articles composed of the film can be made less prone to tearing. 【0025】 The content of 3-hydroxybutyrate units in copolymer (A) is preferably 80 to 90 mol%, more preferably 85 to 90 mol%, even more preferably 87 to 90 mol%, and particularly preferably 88 to 90 mol%. 【0026】The content of copolymer (A) in the total P3HA-based resin components contained in the film according to this embodiment is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 5% by weight or more, even more preferably 8% by weight or more, and particularly preferably 10% by weight or more, from the viewpoint of imparting flexibility to the film. The upper limit is preferably 35% by weight or less, more preferably 30% by weight or less, and even more preferably 25% by weight or less, from the viewpoint of avoiding the film becoming excessively hard and from the viewpoint of improving heat seal strength. 【0027】 Preferably, the poly(3-hydroxyalkanoate) resin component further comprises, in addition to copolymer (A), a copolymer (B) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is less than 76 mol%. By including such copolymer (B), better flexibility can be imparted to the film, and furthermore, the heat seal strength can be improved, making the molded article composed of the film less prone to tearing. 【0028】 The content of 3-hydroxybutyrate units in copolymer (B) is preferably less than 74 mol%. From the viewpoint of film productivity and other factors, the lower limit of this content is preferably 1 mol% or more, more preferably 50 mol% or more, even more preferably 65 mol% or more, and particularly preferably 70 mol% or more. 【0029】 The content of copolymer (B) in the total P3HA-based resin components contained in the film according to this embodiment is preferably 10% by weight or more, more preferably 20% by weight or more, even more preferably 30% by weight or more, and particularly preferably 35% by weight or more, from the viewpoint of providing better flexibility and improving heat seal strength. The upper limit is preferably 60% by weight or less, more preferably 50% by weight or less, and even more preferably 45% by weight or less, from the viewpoint of avoiding the film becoming excessively soft and from the viewpoint of film productivity. 【0030】The total content of copolymer (A) and copolymer (B) in the total P3HA-based resin component contained in the film according to this embodiment is preferably 20% by weight or more, more preferably 30% by weight or more, even more preferably 40% by weight or more, and particularly preferably 50% by weight or more, from the viewpoint of film flexibility. The upper limit is preferably 70% by weight or less, more preferably 65% ​​by weight or less, and even more preferably 60% by weight or less, from the viewpoint of avoiding the film becoming excessively soft and from the viewpoint of film productivity. 【0031】 The poly(3-hydroxyalkanoate) resin component preferably further comprises copolymers (A) and (B), as well as copolymer (C) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is 95 to 99 mol%. Including such copolymer (C) can improve the productivity of the film. The content of 3-hydroxybutyrate units in copolymer (C) is more preferably 96 to 98 mol%. 【0032】 From the viewpoint of improving the productivity of the film, the content of copolymer (C) in the total P3HA-based resin components contained in the film according to this embodiment is preferably 10% by weight or more, more preferably 20% by weight or more, even more preferably 30% by weight or more, and particularly preferably 35% by weight or more. From the viewpoint of the flexibility of the film, the upper limit is preferably 60% by weight or less, more preferably 50% by weight or less, and even more preferably 45% by weight or less. 【0033】As described above, examples of other hydroxyalkanoate units contained in the copolymer (A), copolymer (B), and copolymer (C) include, for example, 3-hydroxyhexanoate units, 3-hydroxyvalerate units, 4-hydroxybutyrate units, 3-hydroxyoctanoate units, 3-hydroxyoctadecanoate units, and the like. Only one type of other hydroxyalkanoate unit may be included, or two or more types may be included. Further, the other hydroxyalkanoate units contained in the copolymer (A), copolymer (B), and copolymer (C) may be the same as each other or different from each other. In particular, it is preferable that the other hydroxyalkanoate unit in at least one or all of the copolymer (A), copolymer (B), and copolymer (C) is 3-hydroxyhexanoate. 【0034】 The P3HA-based resin component contained in the film according to the present embodiment may be composed only of the copolymer (A), copolymer (B), and copolymer (C), or may further contain a P3HA-based resin that does not conform to any of the definitions of the copolymer (A), copolymer (B), and copolymer (C). The total content ratio of the copolymer (A), copolymer (B), and copolymer (C) in the entire P3HA-based resin component is preferably 80% by weight or more, more preferably 90% by weight or more, still more preferably 95% by weight or more, and particularly preferably 99% by weight or more. The upper limit may be 100% by weight or less. 【0035】 The weight average molecular weight of the entire P3HA-based resin component contained in the film according to the present embodiment is not particularly limited, but from the viewpoint of achieving both the strength and productivity of the film, it is preferably 200,000 to 2,000,000, more preferably 300,000 to 1,500,000, and still more preferably 400,000 to 1,000,000. Further, from the viewpoints of film strength and film productivity, the lower limit is preferably 500,000 or more, more preferably 600,000 or more, and still more preferably 700,000 or more. 【0036】 Also, the weight average molecular weight of each polymer contained in the P3HA-based resin component is not particularly limited, and can be appropriately selected from the above numerical ranges. 【0037】The weight-average molecular weight of the P3HA-based resin can be measured in terms of polystyrene using gel permeation chromatography (HPLC GPC system manufactured by Shimadzu Corporation) with a chloroform solution. As the column in the gel permeation chromatography, a column appropriate for measuring the weight-average molecular weight may be used. 【0038】 The method for producing the P3HA-based resin is not particularly limited, and it may be a production method by chemical synthesis or a production method by microorganisms. Among them, the production method by microorganisms is preferred. The microorganism may be a natural microorganism, but a microorganism transformed to produce a predetermined P3HA-based resin can be preferably used. Such transformed microorganisms known in the art can be used. In the P3HA-based resin produced by the microorganism, all 3-hydroxyalkanoate units are contained as (R)-3-hydroxyalkanoate units. 【0039】 The method for obtaining the blend of copolymer (A), copolymer (B) and copolymer (C) is not particularly limited, and it may be a method for obtaining the blend by microbial production or a method for obtaining the blend by chemical synthesis. Also, two or more resins may be melt-kneaded using an extruder, kneader, Banbury mixer, roll, etc. to obtain a blend, or two or more resins may be dissolved in a solvent, mixed and dried to obtain a blend. Further, a plurality of the above-described methods may be combined and implemented. 【0040】 The content ratio of the total amount of the P3HA-based resin component contained in the film according to the present embodiment is not particularly limited, but from the viewpoint of biodegradability, it is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and particularly preferably more than 95% by weight. The upper limit may be 100% by weight or less, but may also be 99% by weight or less, 98% by weight or less, or 97% by weight or less. 【0041】The film according to this embodiment contains a poly(3-hydroxyalkanoate) resin component, but it is preferable that it substantially does not contain a molten mixture of the poly(3-hydroxyalkanoate) resin and an organic peroxide. If the film molded body contains a molten mixture with the organic peroxide, it is likely to cause holes during film molding such as inflation molding, which can lead to a decrease in the stability of the film molding or defects in the film. 【0042】 A molten compound of poly(3-hydroxyalkanoate) resin and organic peroxide has a cross-linked structure formed by the reaction of the poly(3-hydroxyalkanoate) resin with the organic peroxide. 【0043】 Here, "substantially free of a molten mixture of poly(3-hydroxyalkanoate) resin and organic peroxide" means that the proportion of the molten mixture in the total poly(3-hydroxyalkanoate) resin components contained in the film is 10% by weight or less. The proportion is preferably 5% by weight or less, and more preferably 1% by weight or less. The lower limit of the proportion may be 0% by weight. 【0044】The aforementioned organic peroxides are not particularly limited, but examples include diisobutyl peroxide, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis(4-t-butylcyclohexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, and 1,1,3,3-tetramethylbutyl peroxydioxide. Examples include oxy-2-ethylhexanoate, disuccinate peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxy-2-ethylhexyl carbonate, t-butylperoxyisopropyl carbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxy,3,5,5-trimethylhexanoate, 2,2-bis(4,4-di-t-butylperoxycyclohexy)propane, and 2,2-di-t-butylperoxybutane. One type of organic peroxide may be used alone, or two or more types may be used in combination. 【0045】 The amount of organic peroxide used is not particularly limited, but for example, it may be about 0.01 to 0.5 parts by weight per 100 parts by weight of the poly(3-hydroxyalkanoate) resin reacted with the organic peroxide. 【0046】In this embodiment, the film preferably contains a plasticizer in addition to the poly(3-hydroxyalkanoate) resin component. By including a plasticizer, the productivity of the film can be improved, better flexibility can be imparted, and the molded article made from the film can be made less prone to tearing. 【0047】 The aforementioned plasticizer is not particularly limited, but from the viewpoint of compatibility with poly(3-hydroxyalkanoate) resin components, ester-based plasticizers having ester bonds in the molecule are particularly preferred. 【0048】 Examples of ester-based plasticizers include modified glycerin compounds, dibasic acid ester compounds, adipic acid ester compounds, polyether ester compounds, benzoic acid ester compounds, citrate ester compounds, isosorbide ester compounds, and polycaprolactone compounds. Among these, modified glycerin compounds, dibasic acid ester compounds, adipic acid ester compounds, polyether ester compounds, or isosorbide ester compounds are preferred, and modified glycerin compounds are particularly preferred. Furthermore, one ester compound may be used alone, or two or more may be used in combination. When two or more are used in combination, the mixing ratio of these ester compounds can be adjusted as appropriate. 【0049】As the modified glycerin-based compound, glycerin ester compounds are preferred. As the glycerin ester compound, any of glycerin monoester, diester, or triester can be used, but from the viewpoint of compatibility with poly(3-hydroxyalkanoate) resin components, glycerin triesters are preferred. Among glycerin triesters, glycerin diacetonoester is particularly preferred. Specific examples of glycerin diacetonoesters include glycerin diacetonolaurate, glycerin diacetonooleate, glycerin diacetonostearate, glycerin diacetonocaprylate, and glycerin diacetonodecanoate. Examples of the modified glycerin-based compound include Riken Vitamin Co., Ltd.'s "Rikemar" PL series and "BIOCIZER". 【0050】 Specific examples of dibasic acid ester compounds include dibutyl adipate, diisobutyl adipate, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis[2-(2-butoxyethoxy)ethyl] adipate, bis[2-(2-butoxyethoxy)ethyl] adipate, bis(2-ethylhexyl) azelate, dibutyl sebacate, bis(2-ethylhexyl) sebacate, diethyl succinate, and mixed dibasic acid ester compounds. 【0051】 Examples of adipic acid ester compounds include diethylhexyl adipate, dioctyl adipate, and diisononyl adipate. 【0052】 Examples of polyether ester compounds include polyethylene glycol dibenzoate, polyethylene glycol dicaprylate, and polyethylene glycol diisostearate. 【0053】 As for the ester compounds, modified glycerin compounds are preferred due to their cost-effectiveness, versatility, and high biomass content. Glycerin triesters are more preferred, glycerin diacetone monoesters are even more preferred, and glycerin diacetone monolaurates are particularly preferred from the viewpoint of food contact. 【0054】 The plasticizer content is preferably 1 part by weight or more and 10 parts by weight or less per 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) resin component. By setting the plasticizer content to 1 part by weight or more, the productivity of the film can be improved, better flexibility can be imparted, and molded articles made from the film can be made less prone to tearing. Furthermore, by setting the content to 10 parts by weight or less, the productivity of the film and the heat seal strength can be improved. 【0055】 The lower limit of the plasticizer content is preferably 2 parts by weight or more, more preferably 3 parts by weight or more, and even more preferably 4 parts by weight or more. The upper limit is preferably 8 parts by weight or less, more preferably 7 parts by weight or less, and even more preferably 6 parts by weight or less. 【0056】 [Other Resins] The film according to this embodiment may contain resins other than P3HA resins (sometimes referred to as "other resins"). The other resins are not particularly limited as long as they do not significantly reduce compatibility, moldability, or mechanical properties, but if biodegradability is required for the film, biodegradable resins are preferable. 【0057】Examples of such biodegradable resins include aliphatic polyesters, which have a structure formed by the polycondensation of aliphatic diols and aliphatic dicarboxylic acids, and aliphatic aromatic polyesters, which have both aliphatic and aromatic compounds as monomers. However, the resins are not limited to these. Examples of aliphatic polyesters include polyethylene succinate, polybutylene succinate (PBS), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (PBSA), polyethylene sebacate, and polybutylene sebacate. Examples of aliphatic aromatic polyesters include poly(butylene adipate-co-butylene terephthalate) (PBAT), poly(butylene sebacate-co-butylene terephthalate), poly(butylene azelate-co-butylene terephthalate), and poly(butylene succinate-co-butylene terephthalate) (PBST). 【0058】 Other resins can be used individually or in combination of two or more types. 【0059】 The content of other resins in the film according to this embodiment is not particularly limited, but is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 30 parts by weight or less, based on 100 parts by weight of the total amount of P3HA-based resin components. It may also be 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less. The lower limit of the content of other resins is not particularly limited and may be 0 parts by weight. 【0060】[Other Components (Additives)] The film according to this embodiment may contain other components (additives). Examples of such additives include colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolite, fragrances such as vanillin and dextrin, fillers, antioxidants, weather-resistant modifiers, ultraviolet absorbers, crystal nucleating agents, lubricants, mold release agents, water repellents, antibacterial agents, sliding properties modifiers, etc. Only one type of additive may be included, or two or more types may be included. The content of these additives can be appropriately determined by those skilled in the art depending on the intended use. The crystal nucleating agents, lubricants, and fillers will be described in more detail below. 【0061】 (Crystal Nucleating Agent) The film may also contain a crystal nucleating agent. Examples of crystal nucleating agents include sugar alcohols such as pentaerythritol, galactitol, and mannitol; orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, and boron nitride. Among these, pentaerythritol is preferred because it is particularly effective in promoting the crystallization of P3HA resins. One type of crystal nucleating agent may be used, or two or more types may be used, and the ratio of use can be appropriately adjusted depending on the purpose. 【0062】 The amount of nucleating agent used is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, and even more preferably 0.7 to 1.5 parts by weight, per 100 parts by weight of the total amount of P3HA-based resin components. 【0063】 However, the film according to this embodiment does not need to substantially contain the nucleating agent (particularly sugar alcohols or pentaerythritol). Substantially not containing the nucleating agent means that the amount of the nucleating agent is less than 0.1 parts by weight per 100 parts by weight of the total amount of the P3HA resin component. It may even be less than 0.01 parts by weight. In the embodiment that does not substantially contain the nucleating agent, the problem of bleed-out of the nucleating agent and the resulting contamination of the manufacturing equipment can be avoided. 【0064】(Lubricant) The film may also contain a lubricant. Examples of lubricants include behenamide, oleamide, erucamide, stearamide, palmitamide, N-stearylbehenamide, N-stearylerucamide, ethylenebisstearate, ethylenebisoleamide, ethylenebiserucamide, ethylenebislaurylamide, ethylenebiscaprate, p-phenylenebisstearate, and polycondensates of ethylenediamine, stearic acid, and sebacic acid. Among these, behenamide or erucamide are preferred because they have a particularly excellent lubricating effect on P3HA resins. One type of lubricant may be used, or two or more types may be used, and the ratio of use can be appropriately adjusted depending on the purpose. 【0065】 The amount of lubricant used is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and even more preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of the total amount of P3HA resin components. 【0066】 (Filler) The film may contain a filler. Including a filler can make the film stronger. The filler may be either an inorganic filler or an organic filler, or both may be used in combination. The inorganic filler is not particularly limited, but examples include silicates, carbonates, sulfates, phosphates, oxides, hydroxides, nitrides, carbon black, etc. Only one type of inorganic filler may be used, or two or more types may be used in combination. 【0067】 The content of the filler is not particularly limited, but is preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight, even more preferably 5 to 70 parts by weight, and still more preferably 10 to 60 parts by weight, per 100 parts by weight of the total amount of P3HA resin components. 【0068】However, the film may not substantially contain a filler. Even if it does not substantially contain a filler, a film with good strength can be formed. Not substantially containing a filler means that the content of the filler is less than 1 part by weight with respect to 100 parts by weight of the total amount of the P3HA-based resin component. It may be less than 0.1 part by weight, or less than 0.01 part by weight. 【0069】 (Surface roughness) The film according to this embodiment has a surface roughness of a specific value or more on at least one surface. In this application, the arithmetic mean curvature (Spc) of the peak points is used as an index indicating the surface roughness. 【0070】 Specifically, the film according to this embodiment has a film surface with an arithmetic mean curvature (Spc) of the peak points of 450 mm －１ or more. By using a film surface having such a surface roughness as a heat seal surface, the heat seal strength can be improved, and the molded body formed by heat sealing can be made difficult to break. Note that the heat seal surface refers to the film surface that comes into contact with the object to be fused when heat sealing is performed. 【0071】 Although the mechanism by which the heat seal strength is improved by showing a large value of Spc is not clear, it is presumed that the effective contact area of the heat seal surface increases due to the roughness of the film surface, and as a result, the adhesive strength by heat sealing is improved. 【0072】 The Spc is preferably 500 mm －１ or more, more preferably 700 mm －１ or more, still more preferably 800 mm －１ or more, and particularly preferably 900 mm －１ or more. The upper limit is not particularly limited, but from the viewpoint of the tactile sensation of the film or the molded body, etc., it is preferably 3000 mm －１ or less, more preferably 2000 mm －１ or less, and still more preferably 1500 mm －１ or less. 【0073】The arithmetic mean curvature (Spc) of the peaks refers to the surface roughness as defined by ISO 25178. A larger value indicates that the points of contact with other objects on the film surface are sharper, and the film surface is rougher. Commercial measuring instruments can be used to measure this. One example is the VKX-3000 manufactured by Keyence Corporation. 【0074】 The method for manufacturing a film having a surface that satisfies the above-described Spc conditions is not particularly limited. However, the higher the maximum resin temperature reached during film molding, the lower the Spc tends to be. Therefore, in order to control the Spc to a predetermined value or higher, it is desirable to set the resin temperature during film molding as low as possible within the range in which film molding is possible. 【0075】 Furthermore, when forming molded products by heat sealing, heat sealing is sometimes performed immediately after the film is manufactured, but it is also common to store the film for a certain period of time (for example, several days to several months) before heat sealing. During this storage period, the film may be wound into a roll and subjected to considerable surface pressure. However, if the storage period in such a state is prolonged, the Spc tends to decrease. Therefore, in order to control the Spc to a predetermined value or higher, it is desirable to shorten the storage period as much as possible, or to perform heat sealing without any storage period at all. 【0076】 Furthermore, the higher the surface pressure applied to the film during storage, the lower the Spc tends to be. Therefore, in order to control the Spc to a predetermined value or higher, it is desirable to store the film in a way that minimizes the surface pressure applied to it. 【0077】 The surface of a film manufactured and stored considering the conditions described above can satisfy the Spc conditions mentioned above. By using such a film surface that satisfies the Spc conditions as the heat-seal surface, the heat-seal strength can be improved. 【0078】The portion of the film surface not used as the heat-seal surface may or may not satisfy the above-described Spc conditions. Furthermore, the film according to this embodiment may satisfy the Spc conditions on only one side, or both sides may satisfy the Spc conditions. 【0079】 (Film Thickness) The thickness of the film according to this embodiment is not particularly limited, but is preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 80 μm or less, and even more preferably 15 μm or more and 60 μm or less. 【0080】 The film according to this embodiment is preferably a single-layer film. However, a single-layer film with printing applied to its surface is included in the definition of a single-layer film. 【0081】 (Method for manufacturing the film) The film according to this embodiment can be manufactured by melting and kneading resin components and various additives as needed, and then performing film molding. The specific method for film molding is not particularly limited, and extrusion molding using a T-die may be used, but from the viewpoint of productivity, inflation molding is preferable. 【0082】The aforementioned inflation molding refers to a molding method in which a molten resin composition is extruded in a tubular shape from an extruder equipped with a cylindrical die at its tip, and immediately afterward, gas is blown into the tube to inflate it into a balloon shape, thereby forming a tubular single-layer or multi-layer film. The inflation molding method is not particularly limited, but it can be carried out using, for example, a general inflation molding machine used when molding thermoplastic resins into films. A general inflation molding machine, in the case of molding a single-layer film, refers to one in which one cylindrical die is attached to one single-screw extruder. The single-screw extruder should melt and knead the raw resin that is fed in, and obtain a constant discharge while maintaining the desired temperature. The screw shape of the single-screw extruder is not particularly limited, but one equipped with a mixing element is preferable from the viewpoint of kneading performance. The structure of the cylindrical die is also designed as appropriate and is not particularly limited, but among them, a spiral mandrel die is preferred because it produces less weld and makes it easier to obtain uniform thickness. 【0083】 The molding temperature in inflation molding is not particularly limited as long as it is a temperature at which the resin can be properly melted, but for example, 135 to 200°C is preferred. The molding temperature referred to here is the resin temperature from the extruder to the point where it is ejected from the die. The resin temperature can generally be measured by a thermometer installed in an adapter, for example. 【0084】 For the film surface to satisfy the above-mentioned Spc range, it is preferable that the maximum temperature reached by the resin during melting is as low as possible within the range where film molding is possible. Specifically, although it depends on the resin composition, it is usually preferable to be 172°C or lower, more preferably 170°C or lower, and even more preferably 168°C or lower. 【0085】 The take-up rate in inflation molding is determined by the film thickness, width, and resin discharge rate of the molded body, but it can be adjusted within a range that maintains balloon stability. Generally, 1 to 50 m / min is preferred. 【0086】In inflation molding, an air ring blown from the outside of the balloon can be used to solidify the extruded molten resin and stabilize the balloon. A preferred air ring structure is a slit type, which has multiple annular slits from which air is blown, and chambers between each slit promote balloon stabilization. 【0087】 After inflation molding, the process may include taking the tubular molded film, folded on pinch rolls, to a winding roll, blowing air into the interface of the folded film on the pinch rolls to easily separate the folded molded film after winding, and cutting the film during the take-up process according to the application. Cutting methods include cutting both ends of the folded tubular molded film in the width direction to form two films, or hot cutting the tubular molded film in the width direction and fusing it by heat sealing to form a bag-shaped film. It may also include blowing air into the interface of the folded film just before cutting to make it easier to cut. It may also include a process of folding both ends of the folded tubular film inward, a so-called gusset fold. Furthermore, after folding on pinch rolls, it may be printed on the film surface before winding, and corona treatment may be performed on the film surface before printing to further improve print adhesion. The printing method is not particularly limited, but examples include gravure printing and flexographic printing. 【0088】 (Molded body) The film according to this embodiment is used to construct a molded body of a predetermined shape by performing heat sealing on the film surface having the surface roughness described above. The molded body includes the portion where the film is fused. Preferably, the molded body has a Spc of 450 mm as described above. －１ This includes areas where surfaces are fused together. 【0089】The films and molded articles according to this embodiment have excellent biodegradability. Therefore, they can be suitably used in agriculture, fisheries, forestry, horticulture, medicine, hygiene products, the food industry, clothing, non-clothing products, packaging, automobiles, building materials, and other fields. Specific examples of molded articles include garbage bags, shopping bags, vegetable and fruit packaging bags, pillow packaging, delivery bags, bags for gloves, shower caps, aprons, straw packaging bags and other bag containers, bag-shaped protective materials for equipment, storage bags for various documents such as instruction manuals, agricultural mulch films, forestry fumigation sheets, binding tapes including flat yarn, root wrapping films for plants, diaper backsheets, packaging sheets, shopping bags, drainer bags, and other compost bags. 【0090】 In a particularly preferred embodiment, the molded body according to this embodiment is a glove. The glove is constructed by heat-sealing the outermost edges (excluding the hand insertion opening) of two glove-shaped films together. In gloves with such a construction, it is generally difficult to ensure heat-seal strength because the width of the heat-sealed portion is extremely narrow, and stress tends to concentrate between the thumb and index finger, making them prone to tearing at that point. However, according to this embodiment, by satisfying the above-mentioned P3HA-based resin component composition and Spc conditions, it is possible to provide a glove that is resistant to tearing. 【0091】 The heat sealing method refers to a processing method in which a film is pressed together under heat. By fusing a portion of the film through heat sealing, the film can be secondarily processed into the shape of the molded body described above. The heat sealing temperature is not particularly limited and can be set appropriately by those skilled in the art, but it is preferably in the range of 210 to 250°C. Setting the heat sealing temperature to 210°C or higher will achieve good fusion. Setting it to 250°C or lower will suppress the occurrence of pinholes and the like. Particularly preferred is 225 to 235°C. The heat sealing pressure is also not particularly limited and can be set appropriately by those skilled in the art, but for example, it may be 0.1 MPa or higher. 【0092】When manufacturing the gloves described above, two films are stacked so that the film surfaces satisfying the Spc conditions face each other, and then pressed together using a glove-shaped mold. After this, the excess film on the outside of the glove shape is removed to manufacture the gloves. The production speed of the gloves is preferably 100 pieces / min or less, and more preferably 50 pieces / min or less, from the viewpoint of achieving good fusion and suppressing the occurrence of pinholes. 【0093】 The following items list preferred embodiments of the present disclosure, but the present invention is not limited to the following items. [Item 1] A film containing a poly(3-hydroxyalkanoate) resin component, wherein the poly(3-hydroxyalkanoate) resin component includes a copolymer (A) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is 76 mol% or more and 90 mol% or less, the average content of 3-hydroxybutyrate units in the total monomer units constituting the poly(3-hydroxyalkanoate) resin component is 86.0 mol% or less, and the arithmetic mean curvature (Spc) of the peaks measured on at least one face of the film is 450 mm －１The above, a film. [Item 2] The film according to Item 1, wherein the content of the copolymer (A) in the poly(3-hydroxyalkanoate) resin component is 1% by weight or more and 35% by weight or less. [Item 3] The film according to Item 1 or 2, wherein the poly(3-hydroxyalkanoate) resin component further comprises a copolymer (B) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is less than 76 mol%. [Item 4] The film according to any one of Items 1 to 3, wherein the other hydroxyalkanoate units are 3-hydroxyhexanoate units. [Item 5] The film according to any one of Items 1 to 4, further containing an ester-based plasticizer. [Item 6] The film according to any one of Items 1 to 5, which is an inflation-molded film. [Item 7] A molded article comprising the film according to any one of Items 1 to 6. [Item 8] The arithmetic mean curvature (Spc) of the peak is 450 mm －１ A molded article as described in item 7, including a portion where two surfaces are fused together. [Item 9] A molded article as described in item 7 or 8, which is a glove. [Item 10] A film as described in any of items 1 to 6, wherein the arithmetic mean curvature (Spc) of the peak is 450 mm. －１ A method for manufacturing a molded article, comprising the step of fusing the aforementioned surfaces together by heat sealing. 【0094】 The present invention will be specifically described below with reference to examples, but the technical scope of the present invention is not limited by these examples. 【0095】The following raw materials were used in each example and comparative example: [Poly(3-hydroxyalkanoate) resin] P3HB3HH-1 [Poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 97 / 3 (mol% / mol%), weight-average molecular weight is 730,000 g / mol] Manufactured according to the method described in Example 2 of International Publication WO2019 / 142845. P3HB3HH-2 [Poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 94 / 6 (mol% / mol%), weight-average molecular weight is 430,000 g / mol] Manufactured according to the method described in Example 1 of International Publication WO2019 / 142845. P3HB3HH-3 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 89 / 11 (mol% / mol%), weight-average molecular weight is 780,000 g / mol] was produced according to the method described in Comparative Example 1 of International Publication WO2015 / 146195. P3HB3HH-4 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 72 / 28 (mol% / mol%), weight-average molecular weight is 730,000 g / mol] was produced according to the method described in Example 9 of International Publication WO2019 / 142845. 【0096】 [Additives] Additive-1: Behenamide (manufactured by Nippon Seika Co., Ltd.: BNT-22H) Additive-2: Erucamide (manufactured by Nippon Seika Co., Ltd.: Neutron-S) Additive-3: Glycerin fatty acid ester [manufactured by Riken Vitamin Co., Ltd.: BIOCIZER] 【0097】The evaluation methods used in the examples and comparative examples are described below. (Preparation of inflation film) P3HB3HH-1, P3HB3HH-2, P3HB3HH-3, P3HB3HH-4, and each additive were mixed in the proportions shown in Table 1 using a co-meshing twin-screw extruder (Toshiba Machine Co., Ltd.: TEM26ss) at a set temperature of 120°C to 170°C and a screw rotation speed of 150 rpm. After obtaining a molten mixture by strand cutting, an inflation film was prepared using an inflation molding machine (Hokushin Sangyo Co., Ltd.) equipped with a die fitted with a 100 mm diameter cylindrical die slip connected to an extruder with a single-screw L / D = 32, at the molding temperature (resin temperature) shown in Table 1. 【0098】 (Glove Manufacturing) Two layers of inflation film were pressed together using a glove-shaped mold (conditions: 230°C, production speed: 34 pieces / min), and the outer waste material of the glove shape was removed to manufacture the gloves. The gloves have an opening (hand insertion opening) at the wrist side, and the two films are fused together by heat sealing at the outermost edge other than the opening. The width of the heat-sealed area is in the range of approximately 0.1 to 0.5 mm. 【0099】 (Method for measuring the arithmetic mean curvature Spc at the peak) For the heat-sealed surface of the inflation film, the arithmetic mean curvature Spc at the peak was measured as surface roughness using a Keyence VKX-3000 (50x lens). 【0100】 (Method for measuring average thickness) The average thickness of the inflation film was measured along the TD direction of the film using a continuous thickness gauge (TOF-5R01, manufactured by Yamabun Electric Co., Ltd.). 【0101】 (Method for measuring glove rupture strength) Room temperature air was injected into the opening of the glove at a flow rate of 10 L / min until the glove ruptured, and the pressure (kPa) at the time of rupture was measured. 【0102】(Examples 1, 5-7) Using P3HB3HH-1, P3HB3HH-3, P3HB3HH-4, and each additive in the mixing ratios shown in Table 1, inflation films were manufactured using the method described above at the molding temperatures (resin temperature 166°C to 172°C) shown in Table 1. The surface roughness of the film was measured immediately after manufacturing. Gloves were also made using the film, and the tear strength of the gloves was measured. These results are shown in Table 1. 【0103】 (Examples 2-4) After manufacturing the film of Example 1, the film was wound into a roll so that the surface pressure was 2.8 MPa, 1.5 MPa, or 0.2 MPa or less, respectively, and stored in that state for 30 days (temperature: 25°C). The surface roughness of each film after storage was measured. In addition, gloves were made using each of the stored films, and the tear strength of the gloves was measured. These results are shown in Table 1. 【0104】 (Examples 8-10) Inflation films were manufactured in the same manner as in Example 1, except that the blending amounts of each P3HB3HH were changed as shown in Table 1 so that the average HB ratio was the value shown in Table 1. The surface roughness of the film was measured immediately after manufacturing. Gloves were also made using the film, and the tear strength of the gloves was measured. These results are shown in Table 1. 【0105】 (Comparative Example 1) An inflation film was prepared in the same manner as in Example 1, except that P3HB3HH-2 was used instead of P3HB3HH-3, and each evaluation was performed. The evaluation results are shown in Table 1. 【0106】 (Comparative Example 2) The film was stored in the same manner as in Example 2, except that the surface pressure was changed to 3 MPa, and each evaluation was performed on the film after storage. The evaluation results are shown in Table 1. 【0107】 (Comparative Example 3) The film was stored in the same manner as in Example 2, except that the storage period was extended to 60 days, and each evaluation was performed on the film after storage. The evaluation results are shown in Table 1. 【0108】(Comparative Example 4) After manufacturing the film of Example 9, the film was wound into a roll so that the surface pressure was 3 MPa, and stored in that state for 30 days (temperature: 25°C). The film after storage was evaluated. The evaluation results are shown in Table 1. 【0109】 【0110】 Table 1 shows that in Examples 1 to 10, the bag-breaking strength measured for the gloves was high. On the other hand, in Comparative Example 1, which did not contain copolymer (A), the arithmetic mean curvature Spc of the peak measured on the heat-sealed surface was 450 mm. －１ Comparative Examples 2-4, which were below the threshold, showed lower bag rupture strength than Examples 1-10. 【0111】 Furthermore, by comparing Examples 1-2 with Comparative Example 3, it can be seen that the arithmetic mean curvature Spc of the peaks, i.e., the surface roughness of the film surface, decreases as the storage period of the film under surface pressure increases after film manufacturing. Also, by comparing Examples 2-4 with Comparative Example 2, it can be seen that Spc decreases as the surface pressure during storage increases. In addition, by comparing Examples 1 with 5-7, it can be seen that Spc decreases when the resin temperature during film molding is increased.

Claims

1. A film containing a poly(3-hydroxyalkanoate) resin component, wherein the poly(3-hydroxyalkanoate) resin component contains a copolymer (A) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is 76 mol% or more and 90 mol% or less, the average content of 3-hydroxybutyrate units in the total monomer units constituting the poly(3-hydroxyalkanoate) resin component is 86.0 mol% or less, and the arithmetic mean curvature (Spc) of the peaks measured on at least one face of the film is 450 mm. －１ That's all, film.

2. The film according to claim 1, wherein the content of the copolymer (A) in the poly(3-hydroxyalkanoate) resin component is 1% by weight or more and 35% by weight or less.

3. The film according to claim 1, wherein the poly(3-hydroxyalkanoate) resin component further comprises a copolymer (B) of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of 3-hydroxybutyrate units is less than 76 mol%.

4. The film according to claim 1, wherein the other hydroxyalkanoate unit is a 3-hydroxyhexanoate unit.

5. The film according to claim 1, further containing an ester-based plasticizer.

6. The film according to claim 1, which is an inflation-molded film.

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

8. The arithmetic mean curvature (Spc) of the aforementioned mountain peak is 450 mm. －１ The molded article according to claim 7, including a portion where two surfaces are fused together.

9. The molded article according to claim 7, which is a glove.

10. The arithmetic mean curvature (Spc) of the peak of the film according to any one of claims 1 to 6 is 450 mm. －１ A method for manufacturing a molded article, comprising the step of fusing the aforementioned surfaces together by heat sealing.

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