Resin composition for T-die extrusion molding

Abstract

A resin composition for T-die extrusion molding, which contains 100 parts by weight of a poly (3-hydroxyalkanoate)-based resin (A), 0.3-3 parts by weight of a layered clay mineral (B) having an average particle diameter D50 of 1-5 [mu] m and a specific surface area of 10-40 m2 / g as determined by the BET method, and 0.3-3 parts by weight of a fatty acid amide compound (C), and which has a melt viscosity of 300-1000 Pa.s as measured at 175 DEG C and a shear rate of 122 s-1.

Description

Technical Field

[0001] This invention relates to resin compositions for T-die extrusion molding, T-die extrusion molding films, laminates, molded bodies, methods for manufacturing films, and methods for manufacturing laminates. Background Technology

[0002] In recent years, environmental problems caused by waste plastics have attracted much attention. Among them, marine pollution caused by waste plastics is serious, and the widespread adoption of biodegradable plastics that decompose naturally in the environment is highly anticipated.

[0003] As such biodegradable plastics, various plastics are known, especially poly(3-hydroxyalkanoate) resins (hereinafter, sometimes referred to as P3HA resins), which are thermoplastic polyesters produced and accumulated in the cells of a large number of microbial species as energy storage substances. Since they are biodegradable not only in soil but also in seawater, they are attracting attention as raw materials for solving the above-mentioned problems.

[0004] Furthermore, laminates manufactured by laminating P3HA-based resins with biodegradable substrates such as paper are materials where both the resin and the substrate exhibit excellent biodegradability, making them highly promising from an environmental perspective. As a lamination method, the following methods can be selected: a method in which P3HA-based resin is fed into an extruder equipped with a T-die, processed into a film, and then laminated with a substrate; or an extrusion lamination method in which molten P3HA-based resin extruded from a T-die is directly laminated with a separately fed substrate using the same equipment without film formation.

[0005] Although patent document 1 does not involve T-die extrusion molding, it describes a resin composition for injection molding that includes 100 parts by weight of a poly(3-hydroxyalkanoate) resin having a specific monomer composition and 5 to 45 parts by weight of layered clay minerals.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2022 / 065182 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Typically, due to the slow crystallization rate of P3HA-based resins, they tend to adhere easily to the cooling rollers immediately after being extruded from the T-die. Therefore, a large force is required to peel the resin from the cooling rollers, resulting in a fine, uneven structure on the surface of the resulting resin film or layer. This leads to cloudy spots, wrinkles, and a deterioration in the appearance of the resin film or layer.

[0011] However, it is known that if attempts are made to improve the peelability of such cooling rollers, a phenomenon known as "necking" occurs, where the width of the resin film or resin layer (its length in the direction perpendicular to the flow direction) is less than the opening width of the T-die. In particular, when a relatively low molecular weight resin, such as a P3HA-based resin, is used to improve peelability, the melt viscosity decreases, and the increase in necking becomes significant. If necking increases, the target width may not be achieved, or the uniformity of thickness may be compromised due to thickening at the ends.

[0012] In view of the above problems, the object of the present invention is to provide a resin composition for T-die extrusion molding containing P3HA-based resin, which can improve the peelability from the cooling roller after T-die extrusion and reduce necking.

[0013] Problem Solving Methods

[0014] To solve the above problems, the inventors conducted in-depth research and found that, for P3HA-based resins, by combining layered clay minerals and fatty acid amide compounds with specific compositions in specific amounts, and by controlling the melt viscosity of the resin composition within a specific range under specific conditions, the peelability from the cooling roller after extrusion through a T-die can be improved, and necking can be reduced, thus completing the present invention.

[0015] This invention relates to a resin composition for T-die extrusion molding, comprising:

[0016] 100 parts by weight of poly(3-hydroxyalkanoate) resin (A);

[0017] Layered clay minerals (B) 0.3–3 parts by weight, with an average particle size D50 of 1–5 μm determined by laser diffraction and a specific surface area of ​​10–40 m² determined by BET method. 2 / g; and

[0018] Fatty acid amide compound (C) 0.3~3 parts by weight,

[0019] 175℃ and shear rate 122s -1 The melt viscosity measured under the conditions was 300~1000 Pa·s.

[0020] In addition, the present invention also relates to a T-die extrusion molding film comprising the above-mentioned resin composition for T-die extrusion molding.

[0021] In addition, the present invention also relates to a laminate comprising:

[0022] T-die extrusion molding resin layer, comprising the above-mentioned T-die extrusion molding resin composition; and

[0023] Substrate layer.

[0024] In addition, the present invention also relates to a shaped body comprising the above-described laminate.

[0025] In addition, the present invention also relates to a method for manufacturing a membrane, which includes a step of melt extruding the above-mentioned resin composition for T-die extrusion molding using a T-die.

[0026] Furthermore, the present invention also relates to a method for manufacturing a laminate, which is a method for manufacturing the above-mentioned laminate, the method comprising:

[0027] The process of forming the resin layer on at least one side of the substrate layer by using an extrusion lamination method with a T-die.

[0028] Furthermore, the present invention also relates to a method for manufacturing a laminate, which is a method for manufacturing the above-mentioned laminate, the method comprising:

[0029] The process of melt-extruding the aforementioned resin composition for T-die extrusion molding into a film using a T-die; and

[0030] The process of depositing the film on at least one side of the substrate layer and forming the resin layer by any one of dry lamination, solvent-free lamination or hot lamination.

[0031] The effects of the invention

[0032] According to the present invention, a resin composition is provided for T-die extrusion molding containing P3HA-based resin, the resin composition being able to improve peelability from the cooling roller after extrusion from the T-die and to reduce necking.

[0033] According to the present invention, films or laminates containing P3HA-based resins can be manufactured using T-die extrusion with good yield and high productivity. Furthermore, stable long-term production can be achieved.

[0034] The resulting film or laminate has good peelability from the cooling roller, resulting in a good surface condition. Detailed Implementation

[0035] The embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

[0036] The resin composition of this embodiment is a resin composition containing poly(3-hydroxyalkanoate) resin (A) as an essential component.

[0037] [Poly(3-hydroxyalkanoate) resin (A)]

[0038] Poly(3-hydroxyalkanoate) resin (A) (hereinafter, "also referred to as P3HA resin (A)") is a biodegradable aliphatic polyester (a polyester without aromatic rings) containing a repeating 3-hydroxyalkanoic acid unit represented by the general formula: [-CHR-CH2-CO-O-] (where R is C n H 2n+1 The alkyl group shown is an integer n that is 1 or more and 15 or less. The polyhydroxyalkanoate contains, preferably 50 mol% or more of the repeating unit relative to all monomer repeating units (100 mol%), more preferably 70 mol% or more.

[0039] Among P3HA-based resins, poly(3-hydroxybutyrate)-based resins (hereinafter also referred to as "P3HB-based resins") are preferred from the viewpoint that they are particularly easy to obtain and easy to process.

[0040] The aforementioned P3HB-based resin is an aliphatic polyester resin that can be produced by microorganisms, and it is a polyester resin with 3-hydroxybutyrate (hereinafter, sometimes referred to as "3HB") as the repeating unit. This P3HB-based resin can be a poly(3-hydroxybutyrate) with only 3HB as the repeating unit, or it can be a copolymer of 3-hydroxybutyrate and other hydroxyalkyl esters. The copolymerization form is not particularly limited and can be random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, etc. The copolymers produced by microorganisms are usually random copolymers.

[0041] Specific examples of the aforementioned P3HA-based resins (A) include: poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter sometimes referred to as "P3HB3HH"), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (hereinafter sometimes referred to as "P3HB3HV"), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate), poly(3-hydroxybutyrate-co-3-hydroxydecanoate), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate). From the viewpoint of ease of industrial production, poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) are preferred.

[0042] By changing the composition ratio of repeating units, the melting point and crystallinity can be altered, which can change physical properties such as Young's modulus and heat resistance, thus imparting physical properties between polypropylene and polyethylene. Furthermore, from the viewpoint of ease of industrial production and its useful physical properties, P3HB3HH is particularly preferred. Additionally, P3HB3HH is also preferred from the viewpoint of its lower melting point, enabling low-temperature molding and processing.

[0043] Examples of commercially available products using the P3HB3HH brand include: KANEKA Co., Ltd.'s "KANEKA Biodegradable Polymer Green Planet" (registered trademark), etc.

[0044] Regarding the aforementioned P3HB3HV, the melting point and Young's modulus vary depending on the ratio of 3-hydroxybutyrate to 3-hydroxyvalerate. However, due to the co-crystallization of the two components, the crystallinity is as high as 50% or more, making it softer than poly(3-hydroxybutyrate), but the improvement in brittleness is insufficient.

[0045] When the P3HA-based resin (A) comprises a copolymer of 3-hydroxybutyrate and other hydroxyalkanoates, from the viewpoint of balancing mechanical strength (such as flexibility) and curing speed, the monomer unit composition ratio in the copolymer is preferably 3-hydroxybutyrate unit / other hydroxyalkanoate unit = 90 / 10 to 99 / 1 (mol / mol). This composition ratio is more preferably 92 / 8 to 98 / 2 (mol / mol), and even more preferably 94 / 6 to 97 / 3 (mol / mol).

[0046] Furthermore, the copolymer of 3-hydroxybutyrate and other hydroxyalkylates, in which the ratio of 3-hydroxybutyrate unit to other hydroxyalkylate unit is 90 / 10 to 99 / 1 (mol / mol), is preferably contained in 50 to 100% by weight of the P3HA-based resin (A) as a whole. More preferably, it contains 70 to 100% by weight, even more preferably 80 to 100% by weight, even more preferably 90 to 100% by weight, and particularly preferably 95 to 100% by weight.

[0047] The molar ratio of each monomer unit to all monomer units constituting the copolymer can be determined by methods known to those skilled in the art, such as those described in paragraph

[0047] of International Publication No. 2013 / 147139.

[0048] The weight-average molecular weight (hereinafter, sometimes referred to as "Mw") of the P3HA-based resin (A) is not particularly limited. However, the resin composition of this embodiment, from the viewpoint of satisfying the melt viscosity requirements described later, while also considering improved peelability from the cooling roller and reduced necking, is preferably 250,000 to 500,000, more preferably 300,000 to 450,000, and particularly preferably 350,000 to 400,000. If within the above range, the resin composition of this embodiment possesses sufficient mechanical properties, and it is easier to simultaneously improve peelability from the cooling roller and reduce necking.

[0049] The weight-average molecular weight of P3HA resin (A) can be determined by gel permeation chromatography (GPC) (Shodex GPC-101 manufactured by Showa Denko Corporation), using a polystyrene gel column (Shodex K-804 manufactured by Showa Denko Corporation), with chloroform as the mobile phase, and the molecular weight converted from polystyrene.

[0050] As for microorganisms producing P3HA-based resins, any microorganism capable of producing P3HA-based resins is acceptable; there are no particular limitations. For example, the earliest known P3HB-producing bacterium is *Bacillus megaterium*, discovered in 1925. Other known examples include *Cupriavidus necator* (formerly classified as *Alcaligeneseutrophus* and *Ralstonia eutropha*) and *Alcaligenes latus*, among other naturally occurring microorganisms. These microorganisms are known to accumulate P3HB within their cells.

[0051] In addition, known microorganisms that produce copolymers of hydroxybutyrate and other hydroxyalkyl esters include *Aeromonas caviae* as a producer of P3HB3HV and P3HB3HH, and *Alcaligenes eutrophus* as a producer of P3HB4HB. In particular, regarding P3HB3HH, to improve the productivity of P3HB3HH, *Alcaligenes eutrophus* strain AC32 (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, p4821-4830 (1997)) with genes introduced into the P3HA synthase group is more preferred. Microbial cells containing these microorganisms can be cultured under suitable conditions to accumulate P3HB3HH within the cells. In addition to the above, recombinant microorganisms with genes related to the synthesis of various P3HA resins introduced according to the desired P3HA resins can also be used, as long as the culture conditions, including the type of substrate, are optimized.

[0052] Alternatively, P3HB3HH can be manufactured by, for example, the method described in International Publication No. 2010 / 013483.

[0053] The resin composition of this embodiment may contain only one type of resin as a P3HA-based resin (A), or it may contain a combination of two or more resins. When two or more resins (A) are combined, multiple resins with different types of monomers can be used together, or multiple resins with different monomer compositions can be used together.

[0054] When using at least two P3HA-based resins in combination, it is preferable to use at least one highly crystalline P3HA-based resin and at least one low-crystalline P3HA-based resin in combination. Generally, highly crystalline P3HA-based resins have excellent processability but lack mechanical strength, while low-crystalline P3HA-based resins have poor processability but excellent mechanical properties. By combining these resins, a P3HA-based resin composition with excellent processability and mechanical properties can be formed.

[0055] When the aforementioned highly crystalline P3HA-based resin contains 3-hydroxybutyrate units, the content ratio of 3-hydroxybutyrate units in the highly crystalline P3HA-based resin is preferably higher than the average content ratio of 3-hydroxybutyrate units in the entire P3HA-based resin (A). When the highly crystalline P3HA-based resin contains 3-hydroxybutyrate units and other hydroxyalkanoate units, the composition ratio of monomer units in the highly crystalline resin is preferably 3-hydroxybutyrate units / other hydroxyalkanoate units = 90 / 10 to 99 / 1 (mol / mol), more preferably 92 / 8 to 98 / 2 (mol / mol), and even more preferably 94 / 6 to 97 / 3 (mol / mol).

[0056] As the highly crystalline P3HA-based resin, the above-mentioned P3HA-based resin can be used, preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), etc.

[0057] Furthermore, the content ratio of 3-hydroxybutyrate units in the aforementioned low-crystallinity P3HA-based resin is preferably lower than the average content ratio of 3-hydroxybutyrate units in the entire P3HA-based resin (A). When the low-crystallinity P3HA-based resin contains 3-hydroxybutyrate units and other hydroxyalkanoate units, the composition ratio of monomer units in this low-crystallinity resin is preferably 3-hydroxybutyrate units / other hydroxyalkanoate units = 80 / 20 to 0 / 100 (mol / mol), more preferably 76 / 24 to 1 / 99 (mol / mol), even more preferably 76 / 24 to 50 / 50 (mol / mol), and particularly preferably 74 / 26 to 70 / 30 (mol / mol).

[0058] As the aforementioned low-crystallinity P3HA-based resin, the aforementioned P3HA-based resin can be used, preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), etc.

[0059] When using a combination of highly crystalline P3HA resin and a low-crystalline P3HA resin, the proportion of the low-crystalline P3HA resin in the total amount of the two resins is preferably 20 to 50% by weight, more preferably 20 to 40% by weight, and particularly preferably 25 to 35% by weight.

[0060] The resin composition of this embodiment may include one or more resins other than P3HA-based resin (A) within the scope of achieving the effects of the invention. Among these other resins, resins exhibiting biodegradability are preferred, for example: aliphatic polyester resins such as polybutylene succinate, polycaprolactone, and polylactic acid; aliphatic aromatic polyester resins such as polybutylene adipate, polybutylene sebacic acid, and polybutylene azelaic acid; polybutylene adipate succinate; copolymers of polybutylene adipate succinate and lactic acid, terephthalic acid, malic acid, and sebacic acid; and polybutylene adipate succinate-based resins, etc.

[0061] To ensure the biodegradability of this resin composition, the amount of these other resins added is preferably 30 parts by weight or less relative to 100 parts by weight of P3HA-based resin (A). This can be 20 parts by weight or less, 10 parts by weight or less, or 5 parts by weight or less. There is no particular limitation on the lower limit of the content of other resins; it can be 0 parts by weight.

[0062] (Layered clay minerals (B))

[0063] The resin composition of this embodiment further contains layered clay minerals (B). Based on this, the peelability of the cooling roller after extrusion from the T-die can be improved, and necking can be reduced.

[0064] Layered clay minerals are minerals whose main component is layered silicate.

[0065] There is no particular limitation on the layered clay mineral (B), and any known layered clay mineral can be used. From the viewpoint of easily achieving the necking reduction effect, it is preferably selected from one or more of montmorillonite, mica, talc, pyrophyllite, vermiculite, chlorite, kaolinite, and serpentine. From the viewpoint of versatility, mica, talc, and kaolinite are preferred, and talc is particularly preferred.

[0066] Examples of mica mentioned above include wet-processed pulverized mica and dry-processed pulverized mica.

[0067] Examples of talc include general-purpose talc and surface-treated talc.

[0068] Examples of kaolinite include: dry kaolin, calcined kaolin, and wet kaolin.

[0069] As the layered clay mineral (B), a mineral with an average particle size D50 of 1 to 5 μm, determined by laser diffraction, is used. Based on this, both improved peelability from the cooling roller and reduced necking can be achieved. Furthermore, the mechanical properties of the resin film or resin layer formed from the resin composition of this embodiment are improved. If a layered clay mineral with an average particle size D50 exceeding 5 μm is used, while necking can be reduced, peelability from the cooling roller is not sufficient. The average particle size D50 is preferably 1.2 to 4 μm, and more preferably 1.5 to 3 μm. In particular, in the combination of the above-mentioned highly crystalline P3HA-based resin and a low-crystalline P3HA-based resin, if the average particle size D50 of the layered clay mineral (B) is 2 μm or more, peelability from the cooling roller can be further improved.

[0070] It should be noted that the average particle size D50 of layered clay minerals (B) can be measured as the median particle size (D50) using a laser diffraction / scattering particle size distribution measuring device such as the "MicrotracMT3100II" manufactured by Nikkiso Co., Ltd.

[0071] In addition, in order to achieve the function of a nucleating agent for the crystallization of P3HA-based resin (A), a layered clay mineral (B) with a specific surface area of ​​10~40 m² was used. 2 / g of mineral. The more preferred specific surface area is 12~38m². 2 / g, further preferably 15~35m 2 / g. This specific surface area can be determined by the BET method.

[0072] The amount of layered clay mineral (B) incorporating is 0.3 to 3 parts by weight relative to 100 parts by weight of P3HA-based resin (A). By incorporating layered clay mineral within this range, it is possible to achieve both improved peelability from the cooling roller after extrusion from the T-die and reduced necking. Furthermore, it can improve the mechanical properties of the resin film or resin layer. If the amount of layered clay mineral (B) is less than 0.3 parts by weight, there is a tendency to not obtain a sufficient necking reduction effect; if it exceeds 3 parts by weight, there is a tendency for poor dispersion of the layered clay mineral (B) to lead to decreased peelability from the cooling roller. The amount of layered clay mineral (B) incorporating is preferably 0.5 to 2.5 parts by weight, more preferably 1 to 2 parts by weight.

[0073] (Aliphatic amide compound (C))

[0074] Aliphatic amide compounds are among the known additives used as lubricants in the past for adding to resins.

[0075] There are no particular limitations on the aliphatic amide compound (C), for example: lauryl amide, myristyl amide, palmitamide, stearyl amide, etc. Saturated or unsaturated fatty acid amides such as oleamide, erucamide, and methylene distearate amide, and alkylene fatty acid amides such as methylene distearate amide. Among these, from the viewpoint of improving peelability from the cooling roller, the preferred type is... Aliphatic amides, erucamides. Aliphatic amide compounds can be used alone or in combination.

[0076] The amount of aliphatic amide compound (C) is 0.3 to 3 parts by weight relative to 100 parts by weight of P3HA-based resin (A). By setting the amount of aliphatic amide compound (C) to 0.3 parts by weight or more, the improved peelability from the cooling roller due to the addition of this component can be achieved. However, if the amount of aliphatic amide compound (C) exceeds 3 parts by weight, the component will seep out and adhere to the surface of the cooling roller, etc., causing difficulties in continuous processing over a long period of time. The amount of aliphatic amide compound (C) is preferably 0.5 to 2.5 parts by weight, more preferably 1 to 2 parts by weight.

[0077] (Crystallization nucleating agent)

[0078] The resin composition of this embodiment may contain a nucleating agent other than layered clay minerals and aliphatic amide compounds (hereinafter also referred to as "other nucleating agents"). Examples of other nucleating agents include: sugar alcohols such as pentaerythritol, galactitol, and mannitol; orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, and boron nitride. One or more nucleating agents may be used, and the ratio of each agent may be adjusted appropriately according to the purpose.

[0079] When using other nucleating agents, the amount of these agents is not particularly limited, but is preferably 0.1 to 5 parts by weight relative to 100 parts by weight of P3HA-based resin (A), more preferably 0.5 to 3 parts by weight.

[0080] However, the resin composition of this embodiment may also be substantially free of other nucleating agents (especially sugar alcohols or pentaerythritol). Substantially free of other nucleating agents means that the amount of other nucleating agents is less than 0.1 parts by weight relative to 100 parts by weight of the P3HA-based resin (A). It can be less than 0.01 parts by weight. In the manner of substantially free of other nucleating agents, the problems of leaching of other nucleating agents and the associated contamination of the cooling roller surface can be avoided. Since the resin composition of this embodiment contains layered clay minerals (B) and fatty acid amide compounds (C), even without substantially free of other nucleating agents, good peelability from the cooling roller can be achieved.

[0081] In addition to layered clay minerals (B) and fatty acid amide compounds (C), the resin composition of this embodiment may also include additives commonly used in the art, within the scope of achieving the effects of the invention. Examples of such additives include: inorganic fillers such as calcium carbonate, silica, titanium dioxide, and alumina; organic fillers such as rice husks, sawdust, newspaper waste paper, various starches, and cellulose; colorants such as pigments and dyes; odor absorbers such as activated carbon and zeolite; fragrances such as vanillin and dextrin; plasticizers, oxidation inhibitors, antioxidants, weather resistance modifiers, ultraviolet absorbers, lubricants, release agents, water repellents, antibacterial agents, and slip modifiers. Only one additive may be included, or two or more may be included. The content of these additives can be appropriately set by those skilled in the art according to their intended use.

[0082] In the resin composition of this embodiment, the proportion of P3HA-based resin (A) is not particularly limited, and it can be 50% or more by weight, or 60% or more by weight, 70% or more by weight, 80% or more by weight, 90% or more by weight, or 95% or more by weight in the total amount of the resin composition.

[0083] The resin composition of this embodiment is shown at 175°C and a shear rate of 122s. -1 The resin composition having a measured melt viscosity of 300 Pa·s or more and 1000 Pa·s or less is preferred. If the melt viscosity is within this range, shear exothermia in the extruder is suppressed, and crystal nuclei necessary for promoting crystallization upon contact with the cooling roller are easily retained in the molten resin. If the melt viscosity is less than 300 Pa·s, the peelability from the cooling roller becomes insufficient, and sometimes the necking reduction effect cannot be adequately obtained. Furthermore, if the melt viscosity exceeds 1000 Pa·s, the peelability from the cooling roller becomes insufficient, and continuous production is sometimes difficult. The aforementioned melt viscosity is preferably 350 Pa·s or more and 900 Pa·s or less, preferably 400 Pa·s or more and 800 Pa·s or less, and more preferably 500 Pa·s or more and 700 Pa·s or less.

[0084] The melt viscosity of the resin composition of this embodiment can be controlled by adjusting the monomer composition ratio of P3HA resin (A), the weight-average molecular weight of P3HA resin (A), and the amount of components other than P3HA resin (A).

[0085] The resin composition of this embodiment is a resin composition for use in T-die extrusion molding. Specifically, it can be used to produce films by melt extrusion molding using a T-die, or to produce laminates by directly laminating a substrate layer with a molten resin composition extruded from a T-die. Details are described below.

[0086] [Layered structure]

[0087] The laminate of this embodiment includes a substrate layer and a resin layer containing the above-described resin composition, the resin layer being laminated on at least one side of the substrate layer. The surface condition of the resin layer in this laminate is good, and therefore it is advantageous in various applications.

[0088] In this laminate, the resin layer may be laminated on only one side of the substrate layer or on both sides. The resin layer may be laminated onto the substrate layer via other layers or directly onto the substrate layer without any other layers. In addition, other layers may be further laminated on top of the resin.

[0089] (Substrate layer)

[0090] This laminate includes a substrate layer. The substrate layer in this laminate can be any layer capable of being laminated with a resin layer; there are no particular limitations, but a biodegradable layer is preferred. Therefore, the entire laminate, including the resin layer, is biodegradable, making it more advantageous as a raw material for addressing marine pollution problems.

[0091] The biodegradable substrate layer is not particularly limited, and examples include: paper (mainly composed of cellulose), celluloid, cellulose esters; polyvinyl alcohol, polyamino acids, polyglycolic acid, pullulan, or inorganic materials such as aluminum and silica deposited on these substrates. Among these, paper is preferred from the viewpoint of excellent heat resistance and low cost. The type of paper is not particularly limited, and examples include: waxed paper cups, kraft paper, fully chemical pulp paper, coated paper, tissue paper, glassine paper, and cardboard. The type of paper can be appropriately selected according to the intended use of this laminate. Water-resistant agents, water-repellent agents, inorganic materials, etc., can be added to the paper as needed, and it can also be paper with surface treatments such as oxygen barrier coating or water vapor barrier coating.

[0092] Surface treatments such as corona treatment, plasma treatment, ozone treatment, flame treatment, and primer treatment can be applied to the substrate layer. These surface treatments can be performed individually or in combination. In particular, applying corona treatment to the substrate layer during the lamination process and then laminating a resin layer on top of the substrate layer can improve the adhesion strength between the P3HA-based resin (A) and the substrate layer.

[0093] (Resin layer)

[0094] The resin layer in this laminate is formed from the resin composition of this embodiment. This resin layer may contain components other than the resin composition of this embodiment without impairing the effects of the invention. The content of such additives can be appropriately determined by those skilled in the art according to their intended use.

[0095] (Manufacturing method of laminated bodies)

[0096] The laminate in this embodiment is not particularly limited. For example, it can be manufactured by forming a resin layer (laminated layer) containing P3HA-based resin on a substrate layer such as paper and one or both sides thereof using a lamination method.

[0097] The lamination method refers to a method of manufacturing a laminate by pressing a resin layer containing P3HA-based resin onto a substrate layer using a pressing surface, and then peeling the resin layer containing P3HA-based resin off the pressing surface. The pressing surface only needs to be able to press the resin layer containing P3HA-based resin onto the substrate layer, and examples include a plate-shaped surface, the surface of a roller, etc.

[0098] There is no particular limitation on the lamination method. Specifically, examples include: extrusion lamination in which a molten resin composition is extruded from a T-die into a film and directly laminated onto a separately fed substrate layer such as paper, and then cooled and pressed using a cooling roller; and lamination in which a film is made by melt extrusion molding using a T-die and then disposed and pressed onto at least one side of a substrate layer (specifically, dry lamination, solvent-free lamination, and hot lamination).

[0099] The heating temperature (hereinafter also referred to as lamination temperature) in the above-described lamination method is preferably within the range of the temperature of the resin composition of this embodiment during lamination being above the melting point (Tm) of the P3HA-based resin (A) and below a temperature (Tm+30) that is 30°C higher than the melting point (Tm). The melting point mentioned above refers to the peak temperature of the melting point peak on the highest temperature side in the crystallization melting curve obtained by differential scanning calorimetry.

[0100] If the lamination temperature is below the melting point, the resin cannot flow sufficiently, and there is a tendency for the thickness of the resin film or resin layer to become uneven. In addition, if the lamination temperature exceeds 30°C above the melting point, the curing speed of the resin film or the laminated resin layer slows down, resulting in a tendency for insufficient peelability from the cooling rollers.

[0101] Specifically, the lamination temperature is preferably 160°C or higher, more preferably 165°C or higher. Furthermore, the upper limit of the lamination temperature is preferably 180°C or lower. If the lamination temperature is 180°C or lower, it is possible to avoid a decrease in the mechanical strength of the resin film or resin layer due to the thermal decomposition of the P3HA-based resin (A).

[0102] Regarding the lamination temperature mentioned above, the apparatus temperature can be set so that the resin composition containing P3HA-based resin reaches a temperature within the aforementioned range during lamination. For example, in the case of extrusion lamination, the temperature of the T-die can be adjusted; in the case of hot lamination, the temperature of the heating roller used for film lamination can be adjusted.

[0103] In the above lamination method, after the resin composition is extruded from the T-die in a molten state, the surface temperature of the resin composition immediately in contact with the cooling roller is only required to be a temperature sufficient to form a resin film or cool and press the resin layer, preferably 55~65°C, more preferably 57~62°C. Within the above range, the crystallization of the P3HA-based resin (A) is promoted, resulting in reduced adhesion to the cooling roller and enabling curing in a short time.

[0104] Metal rollers can be used as cooling rollers. To avoid adhesion to the resin film or resin layer, rollers with sandblasting or release coating treatments applied to their surfaces can be used. Examples of release coating treatments include fluorine-based coatings, ceramic coatings, and Tosical coatings (a registered trademark of Tosico Co., Ltd.).

[0105] The thickness of the film in this embodiment, or the thickness of the resin layer of the laminate in this embodiment, is not particularly limited. From the viewpoint of preventing the substrate layer from absorbing water and ensuring sufficient flexibility, it is preferably 5 to 300 μm, and more preferably 10 to 200 μm.

[0106] As a substrate layer, using 150~350g / m 2 In the case of waxed paper cups, the thickness of the resin layer is preferably set to 20~100μm, more preferably 30~70μm. By setting the thickness within the above range, secondary processing properties such as die-cutting and heat-sealing properties can be well maintained.

[0107] [Molded body]

[0108] The molded body of this embodiment includes the above-described laminate. Since this molded body is formed from a laminate with a good surface condition of the resin layers, it is advantageous for various applications.

[0109] This molded body can be any material comprising the aforementioned laminates, without particular limitation. Examples include: paper, film, sheet, tube, plate, rod, container (e.g., bottle container), bag, component, etc. From the viewpoint of countermeasures against marine pollution, this molded body is preferably a bag or bottle container.

[0110] The molded body can be the aforementioned laminate itself, or it can be a product of the aforementioned laminate after secondary processing.

[0111] This laminate, through secondary processing, can be used as a molded body containing it as a material for various packaging containers such as shopping bags, various bags, food / snack packaging materials, cups, trays, and cartons (in other words, in various fields such as food, cosmetics, electronics, medical, and pharmaceuticals). Because it contains a resin composition with high adhesion to the substrate and good heat resistance, this laminate is more preferably used as a container for holding liquids, especially for containers for holding warm contents such as cups for instant noodles, instant soup, coffee, etc., as well as trays for dishes, boxed meals, and microwaveable foods.

[0112] The secondary processing can be performed using any method known in the art, such as various bag-making machines and filling packaging machines. Alternatively, it can be done using paper tray compression molding machines, paper cup forming machines, punching machines, box-making machines, and other similar devices. In these processing machines, the bonding method for the molded body can use known techniques, including not only conventional heat sealing but also pulse sealing, ultrasonic sealing, high-frequency sealing, hot air sealing, and flame sealing. This heat sealing can be performed between the substrate layer and the resin layer, or between the resin layers.

[0113] When using a heated heat-sealing tester with a sealing strip for double-sided heating, the heat-sealing temperature for heat-sealing the resin layers of the above-mentioned laminate to each other is typically 150~200°C, preferably 160~190°C, and more preferably 170~180°C. When using a heated heat-sealing tester with a sealing strip for double-sided heating, the heat-sealing temperature for heat-sealing the resin layer and the substrate layer of the above-mentioned laminate is typically 160~220°C, preferably 170~210°C, and more preferably 180~200°C. Within these ranges, resin leaching near the sealing portion can be avoided, ensuring an appropriate resin layer thickness and sealing strength.

[0114] The heat-sealing pressure during the heat sealing of the above-mentioned laminate varies depending on the bonding method. When using a heated heat-sealing testing machine with a sealing strip, the heat-sealing pressure of the molded body is typically 0.1 MPa or higher, preferably 0.3 MPa or higher. If the pressure is above this value, sufficient adhesive strength resulting from heat sealing can be ensured.

[0115] To improve its physical properties, the molded body of this embodiment can also be composited with other molded bodies made of materials different from the molded body (e.g., fibers, filaments, ropes, textiles, woven fabrics, nonwoven fabrics, paper, films, sheets, tubes, plates, rods, containers, bags, components, foams, etc.). These materials are also preferably biodegradable.

[0116] The membrane, laminate, or molded body of this embodiment can be suitably used in agriculture, fisheries, forestry, horticulture, medicine, hygiene products, clothing, non-clothing materials, packaging, automobiles, building materials, and other fields.

[0117] Preferred embodiments of this disclosure are set forth in the following items, but the invention is not limited to the following items.

[0118] [Project 1]

[0119] A resin composition for T-die extrusion molding, comprising:

[0120] 100 parts by weight of poly(3-hydroxyalkanoate) resin (A);

[0121] Layered clay minerals (B) 0.3–3 parts by weight, with an average particle size D50 of 1–5 μm determined by laser diffraction and a specific surface area of ​​10–40 m² determined by BET method. 2 / g; and

[0122] Fatty acid amide compound (C) 0.3~3 parts by weight,

[0123] The resin composition for T-die extrusion molding is subjected to a temperature of 175°C and a shear rate of 122s. -1 The melt viscosity measured under the specified conditions was 300~1000 Pa·s.

[0124] [Project 2]

[0125] According to the resin composition for T-die extrusion molding described in Project 1, wherein...

[0126] The poly(3-hydroxyalkanoate) resin (A) comprises more than 50% by weight of a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of other hydroxyalkanoate units is 1 to 10 mol.

[0127] [Project 3]

[0128] According to the resin composition for T-die extrusion molding described in Project 1 or 2, wherein...

[0129] The poly(3-hydroxyalkanoate) resin (A) comprises a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of other hydroxyalkanoate units is 24 mol% or more.

[0130] [Project 4]

[0131] According to the resin composition for T-die extrusion molding described in item 2 or 3, wherein...

[0132] The other hydroxyalkanoate unit is a 3-hydroxyhexanoate unit.

[0133] [Project 5]

[0134] The resin composition for T-die extrusion molding according to any one of items 1 to 4, wherein...

[0135] The weight-average molecular weight of the poly(3-hydroxyalkanoate) resin (A) is 250,000 to 500,000.

[0136] [Project 6]

[0137] The resin composition for T-die extrusion molding according to any one of items 1 to 5 does not substantially contain pentaerythritol.

[0138] [Project 7]

[0139] A T-die extruded film comprising any one of items 1 to 6 of the resin composition for T-die extrusion molding.

[0140] [Project 8]

[0141] A stack comprising:

[0142] The T-die extrusion molding resin layer contains the resin composition for T-die extrusion molding as described in any one of items 1 to 6; and

[0143] Substrate layer.

[0144] [Project 9]

[0145] According to the laminated body described in Project 8, wherein...

[0146] The substrate layer is biodegradable.

[0147] [Project 10]

[0148] According to the laminated body described in item 8 or 9, wherein...

[0149] The substrate layer is paper.

[0150] [Project 11]

[0151] A molded body comprising any one of items 8 to 10.

[0152] [Project 12]

[0153] A method for manufacturing a membrane, comprising:

[0154] The process of melt extruding a resin composition for extrusion molding using any one of items 1 to 6 using a T-die.

[0155] [Project 13]

[0156] A method for manufacturing a laminate, which is a method for manufacturing the laminate as described in any one of items 8 to 10, the method comprising:

[0157] The process of forming the resin layer on at least one side of the substrate layer using an extrusion lamination method with a T-die.

[0158] [Project 14]

[0159] A method for manufacturing a laminate, which is a method for manufacturing the laminate as described in any one of items 8 to 10, the method comprising:

[0160] The process of melt-extruding a resin composition for extrusion molding using a T-die to form a film; and

[0161] The process of depositing the film on at least one side of the substrate layer and forming the resin layer by any one of dry lamination, solvent-free lamination or hot lamination.

[0162] [Project 15]

[0163] According to the manufacturing method described in item 13 or 14, wherein,

[0164] The heating temperature during extrusion is the melting point (Tm) of the poly(3-hydroxyalkanoate) resin (A) to the melting point (Tm) +30℃, and the temperature of the cooling roller is 55~65℃.

[0165] Example

[0166] The present invention will now be described in more detail based on embodiments, but the present invention is not limited to these embodiments.

[0167] The raw materials for the resin compositions used in the T-die extrusion molding in the examples and comparative examples are shown below.

[0168] [Poly(3-hydroxyalkanoate) resins]

[0169] The following P3HB3HH-1 to P3HB3HH-3 were manufactured in accordance with the methods described in Manufacturing Examples 3 and 4 of International Publication No. WO2019 / 239913.

[0170] P3HB3HH-1: P3HB3HH (average content ratio 3HB / 3HH=94 / 6 (mol% / mol%), weight-average molecular weight is 400,000 g / mol)

[0171] P3HB3HH-2: P3HB3HH (average content ratio 3HB / 3HH=94 / 6 (mol% / mol%), weight-average molecular weight is 600,000 g / mol)

[0172] P3HB3HH-3: P3HB3HH (average content ratio 3HB / 3HH=94 / 6 (mol% / mol%), weight-average molecular weight is 200,000 g / mol)

[0173] P3HB3HH-4: P3HB3HH [average content ratio 3HB / 3HH = 72 / 28 (mol% / mol%), weight-average molecular weight is 600,000 g / mol] was manufactured according to the method described in Example 9 of International Publication No. WO2019 / 142845.

[0174] [Layered clay minerals]

[0175] Talc 1: MICRO ACE SG-200N15 manufactured by Japan Talc Co., Ltd. (average particle size D50 = 1.5 μm, specific surface area = 35 m²) 2 / g)

[0176] Talc 2: MICRO ACE SG-95 manufactured by Japan Talc Co., Ltd. (average particle size D50 = 2.1 μm, specific surface area = 15 m²) 2 / g)

[0177] Talc 3: Microace K-1 manufactured by Japan Talc Co., Ltd. (average particle size D50 = 8.0 μm, specific surface area = 7 m²) 2 / g)

[0178] It should be noted that the average particle size D50 of the layered clay minerals is a value measured using a laser diffraction / scattering particle size distribution measuring device, "Microtrac MT3100II" manufactured by Nikkiso Corporation, as the median particle size (D50).

[0179] [Aliphatic amide compounds]

[0180] Nippon Fine Chemicals Co., Ltd. Acid amide BNT-22H

[0181] The evaluation methods implemented in the embodiments and comparative examples are described below.

[0182] [Methods for determining melt viscosity]

[0183] A flow orifice with a diameter of 1 mm, a length of 10 mm, and an inflow angle of 90° was installed. 15 g of resin granules were filled into a capillary rheometer (barrel diameter 10 mm) heated to 175 °C. After preheating for 5 minutes, the piston was lowered at a speed of 10 mm / min. Based on the stress applied to the piston when molten resin was extruded from the orifice, the melt viscosity at a shear rate of 122 / s was calculated.

[0184] [Peelability from the cooling roller]

[0185] The adhesion of the resin film extruded from the T-die to the cooling roller was observed. The evaluation criteria are as follows.

[0186] <Evaluation>

[0187] ◎: When peeling the resin film off the cooling roller, it can be removed continuously and smoothly without tension.

[0188] ○: There is slight tension when peeling the resin film off the cooling roller, but it can be removed continuously and smoothly.

[0189] △: The resin film can be continuously peeled off from the cooling roller, but the film develops wrinkles.

[0190] ×: The resin is not sufficiently crystallized and therefore cannot be molded.

[0191] [Neck retraction]

[0192] The width of the obtained membrane was measured at 50 mm intervals along the discharge direction, and the necking ((T-die opening width - average membrane width) × 1 / 2) was evaluated based on the average value according to the following criteria.

[0193] <Evaluation>

[0194] ○: Less than 80mm

[0195] ×: 80mm or more

[0196] (Example 1)

[0197] Relative to 100 parts by weight of P3HB3HH-1, the components were dry-mixed (the resin components were mixed in a non-molten state) according to the proportions shown in Table 1 (the proportions in the table are expressed in parts by weight). Next, the resulting compound was melt-mixed using a twin-screw extruder with the barrel and die set to 150°C, extruded into filaments, and then impregnated in a water bath heated to 40°C for crystallization and solidification. Finally, it was cut using a granulator to produce resin granules for T-die extrusion molding. The melt viscosity of the obtained resin granules is shown in Table 1.

[0198] Next, the obtained resin particles were thoroughly dried at 60°C and then fed into a single-screw extruder equipped with a T-die with an opening width of 500 mm and a die lip clearance of 0.7 mm. The extruder was held between a metal roller (150 mm diameter) and a rubber roller (150 mm diameter) and traction was applied at 5 m / min to form a film with a thickness of 40 μm. Peelability from the cooling roller and necking were evaluated at this stage. The extruder barrel and die were set to 170°C, the cooling roller to 60°C, and the air gap (the distance from the die outlet to the point where the molten resin film contacts the cooling roller) was set to 90 mm. The results are shown in Table 1.

[0199] (Examples 2-4, Comparative Examples 1-5)

[0200] The resin formulation was modified as shown in Table 1. Otherwise, resin particles were prepared in the same manner as in Example 1, and the same evaluation was performed as in Example 1. The results are summarized in Table 1.

[0201] [Table 1]

[0202]

[0203] 〔result〕

[0204] As shown in Table 1, in Examples 1 to 4, the evaluation results for the peelability and necking of the cooling roller were good.

[0205] On the other hand, Comparative Example 1 did not include layered clay mineral (B), resulting in poor necking evaluation. In Comparative Example 2, the amount of layered clay mineral (B) was increased to 5 parts by weight, but peelability from the cooling roller was poor. Comparative Example 3 used layered clay mineral (B) with an average particle size D50 as high as 8.0 μm, but peelability from the cooling roller was poor. Comparative Example 4 used a resin composition with a melt viscosity as high as 1060 Pa·s under specific conditions, but peelability from the cooling roller was poor. Comparative Example 5 used a resin composition with the same melt viscosity as low as 290 Pa·s, but both peelability from the cooling roller and necking were poor.

Claims

1. A resin composition for T-die extrusion molding, comprising: 100 parts by weight of poly(3-hydroxyalkanoate) resin (A); Layered clay minerals (B) 0.3–3 parts by weight, with an average particle size D50 of 1–5 μm determined by laser diffraction and a specific surface area of ​​10–40 m² determined by BET method. 2 / g; and Fatty acid amide compound (C) 0.3~3 parts by weight, The resin composition for T-die extrusion molding is subjected to a temperature of 175°C and a shear rate of 122s. -1 The melt viscosity measured under the specified conditions was 300~1000 Pa·s.

2. The resin composition for T-die extrusion molding according to claim 1, wherein, The poly(3-hydroxyalkanoate) resin (A) comprises more than 50% by weight of a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of other hydroxyalkanoate units in the copolymer is 1 to 10 mol.

3. The resin composition for T-die extrusion molding according to claim 2, wherein, The poly(3-hydroxyalkanoate) resin (A) comprises a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, wherein the content of other hydroxyalkanoate units in the copolymer is 24 mol% or more.

4. The resin composition for T-die extrusion molding according to claim 2, wherein, The other hydroxyalkanoate unit is a 3-hydroxyhexanoate unit.

5. The resin composition for T-die extrusion molding according to any one of claims 1 to 4, wherein, The weight-average molecular weight of the poly(3-hydroxyalkanoate) resin (A) is 250,000 to 500,000.

6. The resin composition for T-die extrusion molding according to any one of claims 1 to 4, substantially does not contain pentaerythritol.

7. A T-die extruded film comprising the resin composition for T-die extrusion as described in claim 1.

8. A laminate comprising: A T-die extrusion molding resin layer comprising the T-die extrusion molding resin composition of claim 1, and Substrate layer.

9. The laminate according to claim 8, wherein, The substrate layer is biodegradable.

10. The laminate according to claim 8, wherein, The substrate layer is paper.

11. A molded body comprising the laminate of claim 8.

12. A method for manufacturing a membrane, comprising: The process of melt extruding the resin composition for T-die extrusion molding as described in claim 1 using a T-die.

13. A method for manufacturing a laminate, comprising the method of manufacturing the laminate of claim 8, the method comprising: The process of forming the resin layer on at least one side of the substrate layer using an extrusion lamination method with a T-die.

14. A method for manufacturing a laminate, comprising the method of manufacturing the laminate of claim 8, the method comprising: A process of forming a film by melt extrusion molding of a resin composition for extrusion molding using a T-die; as well as The process of depositing the film on at least one side of the substrate layer and forming the resin layer by any one of dry lamination, solvent-free lamination or hot lamination.

15. The manufacturing method according to claim 13 or 14, wherein, The heating temperature during extrusion is the melting point (Tm) of the poly(3-hydroxyalkanoate) resin (A) to the melting point (Tm) +30℃, and the temperature of the cooling roller is 55~65℃.

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