Resin composition and molded body

Abstract

Provided is a resin composition comprising a poly(3-hydroxyalkanoate)-based copolymer (A) and a lubricant (B). The lubricant (B) comprises at least one component selected from the group consisting of a diester compound composed of a dihydric alcohol and two molecules of a monovalent carboxylic acid and a triester compound composed of a trihydric alcohol and three molecules of a monovalent carboxylic acid. The monovalent carboxylic acid comprises a carboxylic acid having 15 or more carbon atoms. The monovalent carboxylic acid may comprise montanic acid. Each of the dihydric alcohol and the trihydric alcohol may have 2 to 6 carbon atoms.

Description

Resin composition and molded article

[0001] The present invention relates to a resin composition and a molded article containing a poly(3-hydroxyalkanoate) resin.

[0002] Poly(3-hydroxyalkanoate) resins are thermoplastic polyesters that are produced and accumulated as energy storage substances within the cells of many microbial species, and have attracted attention as materials that can biodegrade not only in soil but also in seawater.

[0003] The use of such poly(3-hydroxyalkanoate) resins to produce various molded articles has been investigated. For example, Patent Document 1 discloses the manufacture of sheets by performing calender molding using such resins.

[0004] On the other hand, it is known to add a fatty acid amide such as behenamide or erucamide as a lubricant to impart lubricity to a molded article of a poly(3-hydroxyalkanoate) resin (see, for example, Patent Document 2). The addition of a lubricant suppresses adhesion of the molten resin to the calender roll during, for example, calender molding, and the formed sheet becomes easily peeled off from the roll.

[0005] JP 2022-128070 A JP 2021-102669 A

[0006] A sheet made of a poly(3-hydroxyalkanoate)-based resin may be subjected to secondary molding using a mold to give it a predetermined shape. In such cases, a release agent (e.g., a silicone-based release agent) is often applied to the surface of the sheet in advance so that the sheet can be easily released from the mold after molding. However, conventional sheets made of a poly(3-hydroxyalkanoate)-based resin may repel the release agent, making it difficult to apply the agent evenly.

[0007] Similarly, when printing is performed on the surface of a sheet made of a poly(3-hydroxyalkanoate) resin, the sheet surface may repel the printing ink, and improvement in this respect was also required.

[0008] The inventors have investigated the above-mentioned problems and have found that the behenamide and / or erucamide blended as a lubricant in a sheet made of a poly(3-hydroxyalkanoate) resin causes the sheet to repel release agents and inks.

[0009] Therefore, it is conceivable to improve the applicability and printability of the release agent by not adding these lubricants, but in that case, the lubrication achieved by adding the lubricant becomes insufficient, and for example, the sheet becomes difficult to peel from the roll during calendering.

[0010] In view of the above-described current situation, an object of the present invention is to provide a poly(3-hydroxyalkanoate)-based resin-containing composition that has lubricity and allows for uniform application of a release agent to the surface of a molded article and favorable printing.

[0011] As a result of intensive research aimed at solving the above problems, the present inventors have found that by blending a compound having a specific structure with a poly(3-hydroxyalkanoate) copolymer, it is possible to achieve lubrication equal to or greater than that of conventional lubricants such as behenamide and erucamide, and also to achieve uniform application of a release agent to the surface of a molded article and good printing, thereby completing the present invention.

[0012] That is, the present invention relates to a resin composition containing a poly(3-hydroxyalkanoate) copolymer (A) and a lubricant (B), wherein the lubricant (B) contains at least one selected from the group consisting of a diester compound formed from a dihydric alcohol and two molecules of a monocarboxylic acid, and a triester compound formed from a trihydric alcohol and three molecules of a monocarboxylic acid, and the monocarboxylic acid contains a carboxylic acid having 15 or more carbon atoms. The present invention also relates to a molded article containing the resin composition.

[0013] According to the present invention, it is possible to provide a poly(3-hydroxyalkanoate)-based resin-containing composition that has lubricity and allows for uniform application of a release agent to the surface of a molded article and favorable printing. The resin composition according to the present invention has lubricity, allowing the resin composition to be easily peeled from members that come into contact with the molten resin composition, such as rolls used during melt molding. In addition, a release agent can be uniformly applied to the surface of a molded article made from the resin composition according to the present invention, and the surface has good printability. Furthermore, a molded article made from the resin composition according to the present invention can preferably have a vapor-deposited layer containing an inorganic material on its surface because the vapor-deposited layer has good adhesion to the surface of the molded article.

[0014] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0015] The present embodiment relates to a resin composition containing a poly(3-hydroxyalkanoate) copolymer (A) and a lubricant (B).

[0016] (Poly(3-hydroxyalkanoate)-based copolymer (A)) The resin composition contains a poly(3-hydroxyalkanoate)-based copolymer (A) as a constituent resin. The copolymer (A) is a copolymer having at least one or two or more types of 3-hydroxyalkanoate units.

[0017] The 3-hydroxyalkanoate unit is preferably represented by the following general formula (1): [—CHR—CH ２ -CO-O-] (1)

[0018] In the general formula (1), R is C ｐ H ２ｐ＋１ where p is an integer of 1 to 15. Examples of R include linear or branched alkyl groups such as methyl, ethyl, propyl, methylpropyl, butyl, isobutyl, t-butyl, pentyl, and hexyl. p is preferably an integer of 1 to 10, and more preferably an integer of 1 to 8.

[0019] The poly(3-hydroxyalkanoate) copolymer is preferably a poly(3-hydroxyalkanoate) copolymer produced by a microorganism, in which all 3-hydroxyalkanoate units are contained as (R)-3-hydroxyalkanoate units.

[0020] The poly(3-hydroxyalkanoate) copolymer preferably contains 3-hydroxyalkanoate units (particularly units represented by general formula (1)) in an amount of 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more of all constituent units (monomer units). The poly(3-hydroxyalkanoate) copolymer may contain only two or more types of 3-hydroxyalkanoate units as constituent units of the polymer, or may contain other units (e.g., 4-hydroxyalkanoate units) in addition to one or more types of 3-hydroxyalkanoate units.

[0021] The poly(3-hydroxyalkanoate) copolymer is preferably a copolymer containing 3-hydroxybutyrate (hereinafter sometimes referred to as 3HB) units and other hydroxyalkanoate units, and the 3-hydroxybutyrate units are preferably all (R)-3-hydroxybutyrate units.

[0022] The other hydroxyalkanoate units may be 3-hydroxyalkanoate units other than 3HB units, or may be hydroxyalkanoate units other than 3-hydroxyalkanoate units (for example, 4-hydroxyalkanoate units). Only one type of other hydroxyalkanoate unit may be included, or two or more types may be included.

[0023] Specific examples of poly(3-hydroxyalkanoate) copolymers include poly(3-hydroxybutyrate-co-3-hydroxypropionate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (abbreviation: P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (abbreviation: P3HB3HH), poly(3-hydroxyalkanoate) Examples of suitable polyhydroxybutyrates include poly(3-hydroxybutyrate-co-3-hydroxyheptanoate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), poly(3-hydroxybutyrate-co-3-hydroxynonanoate), poly(3-hydroxybutyrate-co-3-hydroxydecanoate), poly(3-hydroxybutyrate-co-3-hydroxyundecanoate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (abbreviation: P3HB4HB). In particular, from the viewpoints of productivity and mechanical properties of the resin composition, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) being particularly preferred.

[0024] From the viewpoint of productivity and mechanical properties of the resin composition, the poly(3-hydroxyalkanoate) copolymer may contain at least two types of poly(3-hydroxyalkanoate) copolymers different from each other in crystallinity. Specifically, the poly(3-hydroxyalkanoate) copolymers may contain at least two types of poly(3-hydroxyalkanoate) copolymers different from each other in the types of constituent monomers and / or the content ratios of the constituent monomers.

[0025] For example, the poly(3-hydroxyalkanoate) copolymer may include a copolymer (A1) of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of which is 1 to 5 mol %, and a copolymer (A2) of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of which is 24 mol % or more. For example, in addition to the copolymer (A1) and the copolymer (A2), the copolymer preferably further includes a copolymer (A3) of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of which is 6 mol % or more but less than 24 mol %.

[0026] From the viewpoint of achieving both strength and productivity of the resin composition, the average content ratio of 3-hydroxybutyrate units and other hydroxyalkanoate units in all monomer units constituting the entire poly(3-hydroxyalkanoate) copolymer contained in the resin composition according to this embodiment is preferably 3-hydroxybutyrate units / other hydroxyalkanoates = 96 / 4 to 80 / 20 (mol % / mol %), more preferably 95 / 5 to 81 / 19 (mol % / mol %), even more preferably 94 / 6 to 82 / 18 (mol % / mol %), and still more preferably 93 / 7 to 82 / 18 (mol % / mol %).

[0027] The average content ratio of each monomer unit to all monomer units constituting the entire poly(3-hydroxyalkanoate)-based copolymer can be determined by a method known to those skilled in the art, for example, the method described in paragraph

[0047] of WO 2013 / 147139. The average content ratio means the molar ratio of each monomer unit to all monomer units constituting the entire poly(3-hydroxyalkanoate)-based copolymer.

[0028] The weight average molecular weight of the poly(3-hydroxyalkanoate) copolymer is not particularly limited, but from the viewpoint of achieving both strength and productivity of the resin composition, it is preferably 100,000 to 2,000,000, more preferably 250,000 to 1,500,000, and even more preferably 300,000 to 1,000,000.

[0029] The weight-average molecular weight of the poly(3-hydroxyalkanoate) copolymer can be measured in terms of polystyrene using gel permeation chromatography (HPLC GPC system manufactured by Shimadzu Corporation) using a chloroform solution. As the column for the gel permeation chromatography, a column appropriate for measuring the weight-average molecular weight may be used.

[0030] The method for producing the poly(3-hydroxyalkanoate) copolymer is not particularly limited, and may be a production method by chemical synthesis or a production method using a microorganism. Among these, a production method using a microorganism is preferred. Known methods can be applied to the production method using a microorganism. For example, known bacteria that produce copolymers of 3-hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB. In particular, with regard to P3HB3HH, in order to increase the productivity of P3HB3HH, Alcaligenes eutrophus AC32 strain (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)) or the like into which genes encoding P3HA synthases have been introduced is more preferred, and microbial cells obtained by culturing these microorganisms under appropriate conditions and allowing P3HB3HH to accumulate within the cells can be used. In addition to the above, genetically modified microorganisms into which various poly(3-hydroxyalkanoate) resin synthesis-related genes have been introduced may be used depending on the poly(3-hydroxyalkanoate) resin to be produced, or the culture conditions, including the type of substrate, may be optimized.

[0031] The resin composition according to this embodiment contains a lubricant (B), which is an ester compound having a specific structure. The lubricant (B) includes a diester compound composed of a dihydric alcohol and two molecules of a monocarboxylic acid, or a triester compound composed of a trihydric alcohol and three molecules of a monocarboxylic acid. The monocarboxylic acid includes a carboxylic acid having at least 15 carbon atoms. By blending such a lubricant (B) with the poly(3-hydroxyalkanoate) copolymer (A), lubrication is imparted, and a release agent can be uniformly applied to the surface of an article molded from the resin composition, and good printing can be achieved.

[0032] As the lubricant (B), two or more of the diester compounds may be used in combination, or two or more of the triester compounds may be used in combination. Furthermore, only the diester compound may be used, only the triester compound may be used, or the diester compound and the triester compound may be used in combination. The diester compound is superior to the triester compound in providing lubricity, so it is preferable that the lubricant (B) contains at least the diester compound.

[0033] The dihydric alcohol or trihydric alcohol constituting the diester compound or the triester compound refers to an organic compound having two hydroxyl groups or three hydroxyl groups. The number of carbon atoms in the alcohol is not particularly limited, but may be, for example, about 2 to 18, preferably 2 to 12, more preferably 2 to 6, and particularly preferably 2 to 4. The minimum number of carbon atoms in the trihydric alcohol is 3.

[0034] Specific examples of the dihydric alcohol include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, etc. Specific examples of the trihydric alcohol include glycerin, etc.

[0035] The carboxylic acid constituting the diester compound or the triester compound is a monovalent carboxylic acid, i.e., an organic compound having one carboxyl group. The carboxylic acid may be either an aliphatic carboxylic acid or an aromatic carboxylic acid, but is preferably an aliphatic carboxylic acid. The aliphatic carboxylic acid may be either a saturated fatty acid or an unsaturated fatty acid, but is preferably a saturated fatty acid. The saturated fatty acid is preferably a fatty acid having a linear carbon chain.

[0036] The carboxylic acid includes a carboxylic acid having 15 or more carbon atoms. By using an ester compound containing such a relatively long-chain carboxylic acid, it is possible to exert a lubricity-imparting effect on the poly(3-hydroxyalkanoate) copolymer (A). The number of carbon atoms is preferably 16 or more, more preferably 18 or more, even more preferably 20 or more, even more preferably 22 or more, particularly preferably 24 or more, and most preferably 25 or more. There is no particular upper limit on the number of carbon atoms, but it may be, for example, 40 or less, or 30 or less.

[0037] Specific examples of carboxylic acids having 15 or more carbon atoms include pentadecylic acid (15 carbon atoms), palmitic acid (16 carbon atoms), stearic acid (18 carbon atoms), arachidic acid (20 carbon atoms), behenic acid (22 carbon atoms), lignoceric acid (24 carbon atoms), montanic acid (28 carbon atoms), etc. Among these, montanic acid is preferred because of its particularly excellent effect of imparting lubricity.

[0038] The carboxylic acid constituting the diester compound or the triester compound may be solely the carboxylic acid having 15 or more carbon atoms as described above, but may also include a carboxylic acid having 14 or less carbon atoms in addition to the carboxylic acid having 15 or more carbon atoms. Examples of carboxylic acids having 14 or less carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, and myristic acid. However, because of their particularly excellent effect of imparting lubricity, it is preferred that the monovalent carboxylic acid constituting the diester compound or the triester compound be solely composed of a carboxylic acid having 15 or more carbon atoms.

[0039] Specific examples of the diester compound include ethylene glycol dimontanate and butylene glycol dimontanate.

[0040] Specific examples of the triester compound include glycerin tristearate and glycerin trimontanate.

[0041] Lubricant (B) may be composed solely of the diester compound and / or the triester compound, or may be a partial saponification product of these ester compounds. That is, lubricant (B) may contain, in addition to the diester compound and / or the triester compound, a salt of the monocarboxylic acid having 15 or more carbon atoms. Such a salt is preferably an alkali metal salt or an alkaline earth metal salt, and specific examples include potassium salt, sodium salt, and calcium salt. However, because of their particularly excellent lubrication effect, lubricant (B) is preferably composed solely of the diester compound and / or the triester compound.

[0042] The amount of lubricant (B) to be added can be determined appropriately taking into consideration the lubrication, the coatability of the release agent, and the printability, but is preferably 0.01 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the poly(3-hydroxyalkanoate) copolymer (A). From the viewpoint of further improving the lubrication by adding the lubricant (B), the lower limit is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.2 parts by weight or more, even more preferably 0.3 parts by weight or more, and particularly preferably 0.4 parts by weight or more. From the viewpoint of suppressing the influence of the lubricant (B) on the appearance of the obtained molded article, the upper limit is preferably 1.5 parts by weight or less, more preferably 1 part by weight or less, even more preferably 0.8 parts by weight or less, and particularly preferably 0.6 parts by weight or less.

[0043] The resin composition according to this embodiment may contain other resins besides the poly(3-hydroxyalkanoate) copolymer, provided that the effects of the invention are not impaired. Examples of such other resins include aliphatic polyester resins such as polybutylene succinate adipate, polybutylene succinate, polycaprolactone, and polylactic acid, and aliphatic aromatic polyester resins such as polybutylene adipate terephthalate, polybutylene sebatate terephthalate, and polybutylene azelate terephthalate. Only one type of other resin may be contained, or two or more types may be contained.

[0044] The content of the other resin is not particularly limited, but is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, even more preferably 15 parts by weight or less, and even more preferably 10 parts by weight or less, relative to 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) copolymer (A). The lower limit of the content of the other resin is not particularly limited, and may be 0 parts by weight or more.

[0045] The resin composition according to this embodiment may contain additives that can be used together with the poly(3-hydroxyalkanoate) copolymer (A), as long as they do not impair the effects of the invention. Examples of such additives include crystallization nucleating agents, fillers, plasticizers, colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolites, fragrances such as vanillin and dextrin, antioxidants, weather resistance improvers, UV absorbers, release agents, water repellents, antibacterial agents, and sliding properties improvers. Only one type of additive may be contained, or two or more types may be contained. The content of these additives can be appropriately determined by those skilled in the art depending on the intended use.

[0046] Examples of the crystallization nucleating agent include pentaerythritol, orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, boron nitride, etc. Among these, pentaerythritol is preferred because it has a particularly excellent effect of promoting the crystallization of the poly(3-hydroxyalkanoate) copolymer (A).

[0047] When a crystallization nucleating agent is used, the amount used 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 the poly(3-hydroxyalkanoate) copolymer (A). One type of crystallization 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.

[0048] 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 thereof include silicates, carbonates, sulfates, phosphates, oxides, hydroxides, nitrides, and carbon black. Only one type of filler may be used, or two or more types may be used in combination. The filler is preferably one or more selected from the group consisting of talc, silica, mica, kaolinite, montmorillonite, and smectite.

[0049] When a filler is contained, the content thereof is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.5 to 5 parts by weight, per 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) copolymer (A).

[0050] The plasticizer is not particularly limited, but from the viewpoint of compatibility with the poly(3-hydroxyalkanoate) copolymer (A), it is preferable to use an ester compound having an ester bond in the molecule.

[0051] Examples of ester compounds that can be used as plasticizers include modified glycerin compounds, dibasic acid ester compounds, adipate compounds, polyether ester compounds, benzoate ester compounds, citrate ester compounds, isosorbide ester compounds, and polycaprolactone compounds. Among these, modified glycerin ester compounds, dibasic acid ester compounds, adipate ester compounds, polyether ester compounds, and isosorbide ester compounds are preferred. The ester compounds can be used alone or in combination of two or more. When two or more compounds are used in combination, the mixing ratio of the ester compounds can be appropriately adjusted.

[0052] As the modified glycerin compound, a glycerin ester compound is preferred. As the glycerin ester compound, any of glycerin monoesters, diesters, and triesters can be used, but from the viewpoint of compatibility with the poly(3-hydroxyalkanoate) copolymer (A), a glycerin triester is preferred. However, compounds that may fall under the category of lubricant (B) are excluded. Among the glycerin triesters, glycerin diacetomonoester is particularly preferred. Specific examples of glycerin diacetomonoesters include glycerin diacetomonolaurate, glycerin diacetomonocaprylate, and glycerin diacetomonodecanoate. Examples of the modified glycerin compound include Riken Vitamin Co., Ltd.'s "Rikemal" PL series and "BIOCIZER."

[0053] 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-group dibasic acid ester compounds.

[0054] Examples of the adipate compounds include diethylhexyl adipate, dioctyl adipate, and diisononyl adipate.

[0055] Examples of polyether ester compounds include polyethylene glycol dibenzoate, polyethylene glycol dicaprylate, and polyethylene glycol diisostearate.

[0056] When a plasticizer is used, the amount thereof can be appropriately set in consideration of the moldability and strength of the resin composition, but is preferably 0.1 part by weight or more and 10 parts by weight or less, more preferably 1 to 8 parts by weight, and even more preferably 3 to 6 parts by weight, relative to 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) copolymer (A).

[0057] The resin composition according to the present embodiment can be heated to a temperature equal to or higher than the melting point of the resin composition, melted, and then formed into a molded article having a predetermined shape. The molding method that can be used is not particularly limited, and commonly used molding methods can be applied, and specific examples include calendar molding, blow molding, injection molding, extrusion molding, and inflation molding.

[0058] Calendering is a method of producing a film or sheet by rolling and molding a molten resin composition into a sheet while kneading it between heated rolls. Blow molding is a molding method that can produce a hollow molded body such as a bottle by blowing air into the inside of a molten and plasticized resin material. Any of extrusion blow molding, multilayer extrusion blow molding, injection blow molding, stretch blow molding, etc. can be used.

[0059] Injection molding is a method in which a molten resin composition is injected into a mold, the resin composition is cooled and solidified in the mold, the mold is opened, and the molded article is demolded to obtain a molded article. Injection molding methods that can be used include injection molding methods commonly used when molding thermoplastic resins, as well as gas-assisted molding and injection compression molding. In-mold molding, gas press molding, two-color molding, sandwich molding, push-pull molding, SCORIM molding, and the like can also be used. However, the injection molding methods that can be used are not limited to the above methods.

[0060] Extrusion molding is a method of obtaining a long molded product by extruding a molten resin composition through a mold of a specific shape. For example, a film or sheet can be obtained by using a T-die as the mold, and a tube or pipe can be obtained by using a double-cylindrical mold. Inflation molding is a method of obtaining a tubular film by extruding a molten resin composition into a cylindrical shape and inflating it with air.

[0061] According to this embodiment, a molded article can be obtained by various molding methods, which can be easily peeled from a member that comes into contact with the molten resin composition and has good applicability and printability of a release agent. Preferred molded articles include films, sheets, injection molded articles, and blow molded articles. Examples of blow molded articles include extrusion blow molded articles and injection blow molded articles.

[0062] The thickness of the film or sheet is not particularly limited, but may be, for example, about 10 μm or more and about 1 mm or less. When performing secondary molding as described below, the thickness of the film or sheet is preferably about 0.1 to 1 mm, more preferably 0.15 to 0.8 mm, and even more preferably 0.20 to 0.6 mm.

[0063] The uses of the film or sheet are not particularly limited, but they can be preferably used in, for example, agriculture, fisheries, forestry, horticulture, medicine, sanitary products, the food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields. More specifically, they can be used for, for example, agricultural mulch films, forestry fumigation sheets, binding tapes including flat yarns, film for wrapping plant roots, diaper back sheets, packaging sheets, shopping bags, garbage bags, draining bags, and other compost bags.

[0064] The uses of the blow molded articles or injection molded articles are not particularly limited, but examples include bottles, containers, cases for beverages, liquid foods, liquid detergents, etc., toys, entertainment items, tableware, agricultural materials, office automation parts, home appliance parts, body parts for ships and aircraft structures, automobile parts, daily necessities, stationery products, etc.

[0065] The molded article made of the resin composition according to the present embodiment has good printability, and therefore can preferably have a printed layer on its surface. The printed layer is not particularly limited as long as it contains a pigment or a dye. The ink used for printing may be an oil-based ink or a water-based ink.

[0066] A molded article made from the resin composition according to this embodiment can have a release agent layer on its surface because the release agent can be uniformly applied to the surface. A release agent is a chemical that is applied to the surface of a molded article before secondary molding, for example, when the molded article is placed in a mold and secondary molding is performed to give it a predetermined shape, so that the molded article can be smoothly removed from the mold after secondary molding. After application, the agent is appropriately dried to form a film, which can prevent the molded article from adhering to the mold. Specific examples include silicone-based release agents, wax-based release agents, and fluorine-based release agents. The method for applying the release agent is not particularly limited, and known methods can be used. Furthermore, the thickness of the formed release agent layer is also not particularly limited, and can be appropriately determined by those skilled in the art.

[0067] The secondary forming described above is also called thermoforming, and refers to imparting a predetermined shape to a molded body such as a film or sheet while heating and softening it, and for example, a container having a recess can be obtained from a sheet. More specifically, the secondary forming can be carried out by fixing the ends of the molded body such as a film or sheet with clamps or pins, heating and softening the molded body using a far-infrared heater or the like, and then conforming the film to the mold using vacuum or compressed air.

[0068] Specific examples of the thermoforming method include vacuum forming, pressure forming, vacuum pressure forming, matched mold forming, plug assist forming, and TOM forming. Vacuum forming and pressure forming are preferred because they are simple and require low mold costs.

[0069] The device used to heat the molded body in the thermoforming process is not particularly limited, and examples include far-infrared heaters, hot wire heaters, and hot air heaters. Among these, far-infrared heaters are preferred because they provide quick and uniform heating.

[0070] The molded body obtained by thermoforming is not particularly limited, but examples include a container having a recess in the center, a container having a partition, a container having a folded portion around the opening, a lid having a recess or protrusion in the center, and a lid having a curved or stepped structure around part or the entire circumference of the edge.

[0071] The molded article made from the resin composition according to this embodiment can have a release agent uniformly applied to its surface. Therefore, by forming a release agent layer in advance, the molded article can be easily removed from the mold after thermoforming.

[0072] The molded article made of the resin composition according to the present embodiment has good adhesion of the vapor-deposited layer, and therefore can preferably have a vapor-deposited layer containing an inorganic material on the surface. The vapor-deposited layer may contain an inorganic material, but may also be made of only an inorganic material.

[0073] The inorganic material in the vapor-deposited layer may be, for example, a metal or an inorganic oxide, and is not particularly limited, but preferably includes, for example, 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. From the viewpoint of adhesion of the vapor-deposited layer, aluminum or silicon dioxide is particularly preferably used.

[0074] The thickness of the vapor-deposited layer is not particularly limited, but is preferably 5 nm to 100 nm, and more preferably 5 nm to 60 nm, from the viewpoints of productivity, handleability, appearance, etc. When the thickness of the vapor-deposited layer is within this range, the adhesion between the vapor-deposited layer and the molded article and the barrier properties of the vapor-deposited layer (impermeability of the molded article to water vapor and oxygen) can be improved.

[0075] The vapor-deposited layer may be formed on only one side of the molded body, or on both sides. From the viewpoint of ensuring the biodegradability of the molded body, it is preferable that the vapor-deposited layer is formed on only one side of the molded body. Furthermore, it is preferable that the vapor-deposited layer is formed directly on the surface of the molded body without any other layer interposed therebetween.

[0076] The molded article having the vapor-deposited layer may further be laminated with a resin layer, etc. For example, when the molded article is to be heat-sealed, a resin layer may further be laminated on the vapor-deposited layer.

[0077] A molded article having a vapor-deposited layer containing an inorganic material formed on its surface can be preferably used for, for example, paper, film, sheet, tube, plate, rod, container (e.g., bottle container), bag, part, etc., and from the viewpoint of measures against marine pollution, it can be particularly preferably used for film or bottle container.

[0078] Examples of methods for forming the vapor deposition layer include vacuum deposition, sputtering, chemical vapor deposition, and ion plating.

[0079] In order to improve the adhesion between the vapor-deposited layer and the molded body and the barrier properties of the molded body, it is preferable to subject the surface of the molded body to a corona treatment or plasma treatment before vapor deposition. The treatment intensity when performing corona treatment is 5 to 80 W·min / m２ It is preferable that the power consumption is 10 to 60 W·min / m ２ It is more preferable to form a metal deposition layer with nuclei under plasma discharge before forming the deposition layer, from the viewpoint of improving the adhesion of the deposition layer and, consequently, improving the barrier properties. In this case, it is preferable to perform the plasma discharge in an atmosphere containing oxygen gas, nitrogen gas, argon gas, or the like.

[0080] The following items list preferred embodiments of the present disclosure, but the present invention is not limited to them. [Item 1] A resin composition containing a poly(3-hydroxyalkanoate) copolymer (A) and a lubricant (B), wherein the lubricant (B) comprises at least one compound selected from the group consisting of a diester compound composed of a dihydric alcohol and two molecules of a monovalent carboxylic acid, and a triester compound composed of a trihydric alcohol and three molecules of a monovalent carboxylic acid, and the monovalent carboxylic acid comprises a carboxylic acid having 15 or more carbon atoms. [Item 2] The resin composition according to Item 1, wherein the monovalent carboxylic acid comprises an aliphatic carboxylic acid. [Item 3] The resin composition according to Item 1 or 2, wherein the monovalent carboxylic acid comprises a carboxylic acid having 25 or more carbon atoms. [Item 4] The resin composition according to any one of Items 1 to 3, wherein the monovalent carboxylic acid comprises montanic acid. [Item 5] The resin composition according to any one of Items 1 to 4, wherein the dihydric alcohol and the trihydric alcohol each have 2 to 6 carbon atoms. [Item 6] The resin composition according to any one of Items 1 to 5, wherein the lubricant (B) comprises the diester compound. [Item 7] The resin composition according to any one of Items 1 to 6, wherein the lubricant (B) further comprises a salt of a carboxylic acid having 15 or more carbon atoms. [Item 8] The resin composition according to any one of Items 1 to 7, wherein the amount of the lubricant (B) blended is 0.01 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the poly(3-hydroxyalkanoate)-based copolymer (A). [Item 9] The resin composition according to any one of Items 1 to 8, wherein the poly(3-hydroxyalkanoate)-based copolymer (A) is a copolymer containing 3-hydroxybutyrate units and other hydroxyalkanoate units. [Item 10] The resin composition according to Item 9, wherein the other hydroxyalkanoate units are 3-hydroxyhexanoate units. [Item 11] A molded article comprising the resin composition according to any one of Items 1 to 10. [Item 12] The molded article according to Item 11, wherein the molded article is a film or sheet. [Item 13] The molded article according to Item 11, wherein the molded article is an extrusion blow molded article or an injection blow molded article.[Item 14] The molded article according to any one of items 11 to 13, which has a printed layer and / or a release agent layer on its surface. [Item 15] The molded article according to any one of items 11 to 14, which has a vapor-deposited layer containing an inorganic material on its surface.

[0081] EXAMPLES The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0082] (Raw materials used) PHBH (1'): poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH) obtained according to the method described in WO 2008 / 010296, having a 3-hydroxyhexanoate (3HH) composition of 5.1 mol% and a weight average molecular weight of 760,000 in terms of standard polystyrene as measured by GPC. PHBH (1''): P3HB3HH obtained according to the method described in WO 2013 / 147139, having a 3HH composition of 10.5 mol% and a weight average molecular weight of 580,000 in terms of standard polystyrene as measured by GPC. PHBH (2'): P3HB3HH obtained according to the method described in WO 2008 / 010296, having a 3HH composition of 4.2 mol% and a weight average molecular weight of 570,000 in terms of standard polystyrene as measured by GPC. PHBH (3'): 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 660,000 in terms of standard polystyrene measured by GPC

[0083] (Composition of raw materials used) PHBH (1): Powder obtained by blending 70 parts by weight of PHBH (1'), 30 parts by weight of PHBH (1"), and 5 parts by weight of filler. PHBH (2): Powder obtained by blending 70 parts by weight of PHBH (2'), 30 parts by weight of PHBH (1"), and 5 parts by weight of filler. PHBH (3): Powder obtained by blending 60 parts by weight of PHBH (3'), 40 parts by weight of PHBH (1"), and 15 parts by weight of filler.

[0084] Lubricant (B): Ethylene glycol dimontanate, mixture of butylene glycol dimontanate and calcium montanate, glycerin tristearate

[0085] Other additives for comparison: Erucamide Pentaerythritol Tetrastearate Behenamide Glycerin Diacetate Monolaurate

[0086] Filler: Talc [Microace K-1 (Nippon Talc)]

[0087] (Processing Method 1) PHBH (1), PHBH (2), or PHBH (3) according to the composition described in "Composition of Raw Materials Used" was placed in a Φ8 inch x L20 roll (manufactured by Kansai Roll Co., Ltd.) heated to a set temperature of 145°C, melt-kneaded for 3 minutes, and rolled to a sheet width of 32 cm. The sheet was then stretched in the MD direction at a draw ratio of 1.0 to 1.5 times while being cooled to obtain a resin sheet with a thickness of 0.5 to 0.6 mm. At this time, the ease of peeling the sheet from the roll was evaluated as "roll peelability." The "appearance" of the obtained sheet was also evaluated.

[0088] (Method for measuring average molecular weight) The weight average molecular weight of a poly(3-hydroxyalkanoate) copolymer was measured by first dissolving the poly(3-hydroxyalkanoate) copolymer to be measured in chloroform and heating it in a hot water bath at 60°C for 0.5 hours, filtering the soluble matter through a disposable PTFE filter with a 0.45 μm pore size, and then using the filtrate to perform GPC measurement under the following conditions: GPC measurement device: RI monitor (L-3000) manufactured by Hitachi, Ltd. Columns: K-G (1 column), K-806L (2 columns) manufactured by Showa Denko K.K. Sample concentration: 3 mg / ml Free liquid: chloroform solution Free liquid flow rate: 1.0 ml / min Sample injection amount: 100 μL Analysis time: 30 min Standard sample: standard polystyrene

[0089] (Evaluation Method) (Roll Removal Property) When the sheets produced in each Example and Comparative Example were removed from the roll, the ease of removal was evaluated according to the following criteria: ×: The sheet could not be removed from the roll. △: The sheet was taken up by the roll and was difficult to remove from the roll. ○-: The sheet could be removed without being taken up by the roll. ○: The sheet peeled off easily from the roll without any force being applied.

[0090] (Sheet Appearance) The surface appearance of the sheets produced in each Example and Comparative Example was visually evaluated according to the following criteria: ◯: The appearance of the sheet surface is good Δ: There are bubbles or holes on the sheet surface

[0091] (Release Agent Coating Ability) The sheets produced in each Example and Comparative Example were cut to 10 cm x 10 cm, and 0.1 to 0.2 g of a liquid obtained by diluting emulsion-type silicone release agent KM-9782 (manufactured by Shin-Etsu Chemical Co., Ltd.) 15 times was dropped onto the surface of the sheet. When the liquid was spread, it was confirmed whether the surface of the sheet repelled the release agent. Evaluation was made according to the following criteria. ○: The surface of the sheet did not repel the release agent ×: The surface of the sheet repelled the release agent

[0092] (Printability) Ink was spread on the surface of the sheets produced in each Example and Comparative Example using a water-based black brush pen to check whether the sheet surface repels ink. ○: The sheet surface does not repel ink. ×: The sheet surface repels ink.

[0093] (Adhesion of Vapor-Deposited Layer) A vapor-deposited layer (thickness: 100 nm) containing aluminum as an inorganic material was formed on the surface of the sheet produced in each Example and Comparative Example. The vapor-deposited layer was formed on a sheet cut into a 30 mm square using a film-forming device (UHSP-T2040H, manufactured by Shimadzu Industrial Machinery Systems Co., Ltd.) under an argon gas atmosphere. The resulting sheet having the vapor-deposited layer was subjected to the cross-cut method (JIS-K5600-6), and the adhesion of the vapor-deposited layer was evaluated based on the area ratio (%) of the area where the vapor-deposited layer had peeled off relative to the surface to be evaluated. ◯: The area where the vapor-deposited layer had peeled off was less than 25%. △: The area where the vapor-deposited layer had peeled off was 25% or more but 75% or less. ×: The area where the vapor-deposited layer had peeled off was more than 75% of the surface.

[0094] Example 1 100 parts by weight of PHBH (2) and 0.05 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the method described in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0095] Example 2 100 parts by weight of PHBH (2) and 0.07 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0096] Example 3 100 parts by weight of PHBH (2) and 0.1 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0097] Example 4 100 parts by weight of PHBH (3) and 0.1 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0098] Example 5 100 parts by weight of PHBH (3) and 0.3 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0099] Example 6 100 parts by weight of PHBH (1) and 0.1 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0100] Example 7 100 parts by weight of PHBH (1) and 0.3 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0101] Example 8 100 parts by weight of PHBH (1) and 0.5 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0102] Example 9 100 parts by weight of PHBH (3) and 0.5 parts by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0103] Example 10 100 parts by weight of PHBH (1) and 1.0 part by weight of ethylene glycol dimontanate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0104] Example 11 100 parts by weight of PHBH (1) and 0.1 parts by weight of a mixture of butylene glycol dimontanate and calcium montanate were added, and a sheet was obtained by the method described in Processing method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0105] Example 12 100 parts by weight of PHBH (1) and 0.5 parts by weight of a mixture of butylene glycol dimontanate and calcium montanate were added, and a sheet was obtained by the method described in Processing method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0106] Example 13 100 parts by weight of PHBH (1) and 1.0 part by weight of a mixture of butylene glycol dimontanate and calcium montanate were added, and a sheet was obtained by the method described in Processing method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0107] Example 14 100 parts by weight of PHBH (1) and 0.5 parts by weight of glycerin tristearate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0108] <Comparative Example 1> 100 parts by weight of PHBH (1) was added, and a sheet was obtained by the method described in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0109] <Comparative Example 2> 100 parts by weight of PHBH (3) was added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0110] <Comparative Example 3> 100 parts by weight of PHBH (1) and 0.5 parts by weight of erucic acid amide were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0111] Comparative Example 4 100 parts by weight of PHBH (3) and 0.5 parts by weight of erucic acid amide were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0112] Comparative Example 5 100 parts by weight of PHBH (1) and 1.0 part by weight of erucic acid amide were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0113] <Comparative Example 6> 100 parts by weight of PHBH (1) and 0.5 parts by weight of pentaerythritol tetrastearate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0114] <Comparative Example 7> 100 parts by weight of PHBH (1) and 0.5 parts by weight of behenic acid amide were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0115] Comparative Example 8 100 parts by weight of PHBH (1) and 0.5 parts by weight of glycerin diacetate monourarate were added, and a sheet was obtained by the same method as in Processing Method 1. Using the obtained sheet, roll releasability, sheet appearance, release agent applicability, and printability were evaluated, and the results are shown in Table 1.

[0116]

[0117] As can be seen from Table 1, Examples 1 to 13, in which a compound meeting the definition of lubricant (B) was added, had better roll releasability than Comparative Examples 1 and 2, in which the resin was used alone. In addition, release agent applicability and printability were also good. Among these Examples, Examples 1 to 9, 11, 12, and 14 also had good sheet appearance. Comparative Examples 3 to 7, in which a substance not meeting the definition of lubricant (B) was added, had poor release agent applicability and printability, and Comparative Examples 7 and 8 had insufficient roll releasability. The erucic acid amide used in Comparative Examples 3 to 5 and the behenic acid amide used in Comparative Example 7 are conventionally known lubricants. The compound used in Comparative Example 6 was a tetraester compound. The compound used in Comparative Example 8 is a substance known as a plasticizer.

[0118] Example 15 A vapor-deposited layer containing aluminum was formed on the sheet produced in Example 9, and the adhesion of the vapor-deposited layer was evaluated. The results are shown in Table 2.

[0119] Comparative Example 9 A vapor-deposited layer containing aluminum was formed on the sheet produced in Comparative Example 2, and the results are shown in Table 2.

[0120] Comparative Example 10 A vapor-deposited layer containing aluminum was formed on the sheet produced in Comparative Example 4, and the results are shown in Table 2.

[0121]

[0122] As can be seen from Table 2, Example 15, in which a compound meeting the definition of lubricant (B) was added, had better adhesion of the vapor-deposited layer than Comparative Example 9, in which only the resin was used, and Comparative Example 10, in which a compound not meeting the definition of lubricant (B) was added.

Claims

1. A resin composition containing a poly(3-hydroxyalkanoate) copolymer (A) and a lubricant (B), the lubricant (B) contains at least one compound selected from the group consisting of a diester compound composed of a dihydric alcohol and two molecules of a monocarboxylic acid, and a triester compound composed of a trihydric alcohol and three molecules of a monocarboxylic acid, the monocarboxylic acid includes a carboxylic acid having 15 or more carbon atoms, The resin composition has a blending amount of the lubricant (B) of 0.01 to 2 parts by weight per 100 parts by weight of the poly(3-hydroxyalkanoate) copolymer (A).

2. The resin composition according to claim 1 , wherein the monocarboxylic acid comprises an aliphatic carboxylic acid.

3. The resin composition according to claim 1 or 2, wherein the monovalent carboxylic acid includes a carboxylic acid having 25 or more carbon atoms.

4. The resin composition according to claim 1 or 2, wherein the monovalent carboxylic acid includes montanic acid.

5. 3. The resin composition according to claim 1, wherein the dihydric alcohol and the trihydric alcohol each have 2 to 6 carbon atoms.

6. The resin composition according to claim 1 or 2, wherein the lubricant (B) comprises the diester compound.

7. The resin composition according to claim 1 or 2, wherein the lubricant (B) further comprises a salt of a carboxylic acid having 15 or more carbon atoms.

8. The resin composition according to claim 1 or 2, wherein the poly(3-hydroxyalkanoate) copolymer (A) is a copolymer containing 3-hydroxybutyrate units and other hydroxyalkanoate units.

9. The resin composition according to claim 8, wherein the other hydroxyalkanoate units are 3-hydroxyhexanoate units.

10. A molded article comprising the resin composition according to claim 1 or 2.

11. The molded article according to claim 10, wherein the molded article is a film or a sheet.

12. The molded article according to claim 10, wherein the molded article is an extrusion blow molded article or an injection blow molded article.

13. The molded article according to claim 10, which has a printed layer and / or a release agent layer on its surface.

14. The molded article according to claim 10 , which has a vapor-deposited layer containing an inorganic material on its surface.