Method for manufacturing films and laminates

Abstract

To provide a method for manufacturing a film containing a poly(3-hydroxy butyrate)-based resin or a laminate obtained by laminating a resin layer containing a poly(3-hydroxy butyrate)-based resin on the surface of a base material layer such as paper which improves peelability between the poly(3-hydroxy butyrate)-based resin and a cooling roll, and continuously manufactures the film or the laminate.SOLUTION: A method for manufacturing a film containing a poly(3-hydroxy butyrate)-based resin includes the steps of: melting a resin raw material containing the poly(3-hydroxy butyrate)-based resin by an extruder, and then molding the resin raw material into a film shape; and bringing the molded film into contact with a cooling roll, and cooling the film, wherein a cooling roll is used which has an absolute value of a difference (d2-d1) between a contact angle (d2) of the surface of the cooling roll that is brought into contact with at least the film and a contact angle (d1) on the surface of the film of 25° or more and 65° or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a film and a laminate, including a poly(3-hydroxybutyrate) - based resin.

Background Art

[0002] Poly(3-hydroxybutyrate) - based resin (hereinafter sometimes referred to as "P3HB - based resin") is a thermoplastic polyester produced and accumulated as an energy storage substance in the cells of many microbial species. P3HB - based resin is completely biodegradable by microorganisms in soil or water and is incorporated into the carbon cycle process of nature. Therefore, it can be said that P3HB - based resin is an environmentally friendly plastic with little adverse impact on the ecosystem.

[0003] Generally, an extruded film of resin or a laminate formed with a resin layer (laminate layer) by extrusion lamination of resin on a base material layer is produced by melting the resin, forming the resin into a film shape using a T - die or the like, and cooling and solidifying it.

[0004] However, when continuously producing a film or a laminate using a P3HB - based resin, after melt - extrusion of the resin, it requires a long solidification (crystallization) time. Therefore, the molten resin is likely to block (stick) to the cooling roll that first contacts after film forming, making it difficult to continuously form a film or a laminate. Or, when peeling from the roll, fine irregularities are formed on the resin surface by forcibly peeling it off, resulting in problems such as deterioration of the appearance, such as cloudiness.

[0005] Patent Document 1 describes a method of manufacturing a laminate by co-extruding lamination on both sides of a paper substrate, such that a polyhydroxyalkanoate resin layer and an outer layer are polycondensed polyester resin layers of dicarboxylic acid and glycol with good processability (less prone to sticking), thereby preventing blocking to the cooling roll. However, the polycondensed polyester and polylactic acid used in Patent Document 1 are less easily decomposed by microorganisms in the natural environment compared to P3HB resins, which presents challenges in terms of the biodegradability of the laminate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-6444 [Overview of the project] [Problems that the invention aims to solve]

[0007] In view of the above situation, the present invention aims to provide a method for continuously manufacturing a film or laminate by improving the peelability of the poly(3-hydroxybutyrate) resin from a cooling roll when manufacturing a laminate in which a resin containing poly(3-hydroxybutyrate) resin is laminated onto the surface of a substrate layer such as a film or paper containing poly(3-hydroxybutyrate) resin. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the present inventors have found that by using a surface treatment roll having specific surface characteristics as a cooling roll, the peelability of resins including P3HB resins from the roll surface of the cooling roll and other rolls can be improved, enabling the continuous production of films and laminates with good surface conditions, thus completing the present invention.

[0009] In other words, the present invention is a method for producing a film containing a poly(3-hydroxybutyrate) resin, The process involves melting the resin raw material containing the aforementioned poly(3-hydroxybutyrate) resin in an extruder and then forming it into a film, and The process includes cooling the molded film by bringing it into contact with a cooling roll, The present invention relates to a method for manufacturing a film, using a cooling roll in which the absolute value of the difference (d2 - d1) between the contact angle (d1) of the surface of the film and the contact angle (d2) of the surface of the cooling roll that is in contact with at least the film is 25° or more and 65° or less.

[0010] Furthermore, the present invention relates to a method for producing a laminate having a resin layer containing a poly(3-hydroxybutyrate) resin as the outermost layer, The process involves melting the resin containing the aforementioned poly(3-hydroxybutyrate) resin in an extruder and then forming it into a film, and The process includes laminating the film onto the surface of a substrate while the film is in contact with a cooling roll, The present invention also relates to a method for manufacturing a laminate, wherein a cooling roll is used in which the absolute value of the difference (d2 - d1) between the contact angle (d1) of the surface of the film and the contact angle (d2) of the surface of the cooling roll that is in contact with at least the film is 25° or more and 65° or less.

[0011] Preferably, the contact angle (d2) is higher than the contact angle (d1).

[0012] Preferably, the absolute value of the difference in the contact angles (d2-d1) is 40° or more and less than 65°.

[0013] Preferably, the cooling roll is made of a coating material containing a resin component that is fixed to it.

[0014] Preferably, the coating material contains at least one selected from the group consisting of fluororesin-based materials and silicone resin-based materials. [Effects of the Invention]

[0015] In view of the above situation, the present invention improves the peelability of the poly(3-hydroxybutyrate) resin from the cooling roll when manufacturing a laminate in which a resin containing poly(3-hydroxybutyrate) resin is laminated onto the surface of a substrate layer such as a film or paper containing poly(3-hydroxybutyrate) resin, thereby enabling the continuous manufacture of the film or laminate. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0017] [(Poly-3-hydroxybutyrate) resin] The (poly-3-hydroxybutyrate) resin (P3HB resin) according to the present invention is an aliphatic polyester resin containing repeating units of 3-hydroxybutyrate represented by the general formula: [-CH(CH3)-CH2-CO-O-].

[0018] The P3HB resin may be a poly(3-hydroxybutyrate) in which only 3-hydroxybutyrate represented by the above general formula is used as the repeating unit, or it may be a copolymer of 3-hydroxybutyrate and other hydroxyalkanoates. In the latter case, the form of copolymerization is not particularly limited and may be random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, etc., but random copolymerization is preferred because it is readily available.

[0019] Specific examples of the P3HB-based resin include poly(3-hydroxybutyrate) (P3HB), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (P3HB3HO), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate) (P3HB3HOD), poly(3-hydroxybutyrate-co-3-hydroxydecanoate) (P3HB3HD), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), and the like. Among them, P3HB, P3HB3HH, P3HB3HV, and P3HB4HB are preferred because they are easy to produce industrially.

[0020] In the case where the P3HB-based resin is a copolymer having a plurality of types of repeating units, by changing the composition ratio of the repeating units, the melting point and crystallinity can be changed, and physical properties such as Young's modulus and heat resistance can be changed, and it is possible to impart physical properties between polypropylene and polyethylene. Also, from the viewpoint that it is easy to produce industrially and is a physically useful plastic as described above, P3HB3HH, which is a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate, is more preferred. Also, P3HB3HH is particularly preferred from the viewpoint that it can lower the melting point and enables molding processing at low temperatures.

[0021] In the method for producing the film or laminate of the present invention, the P3HB-based resin can be used alone or in combination of two or more.

[0022] In one embodiment of the present invention, the P3HB-based resin preferably contains at least one type of P3HB3HH, and particularly preferably contains at least two types of P3HB3HH in which the content ratios of the constituent monomers are different from each other. It is also preferable to contain at least one type of P3HB3HH and P3HB.

[0023] Specific production methods of P3HB3HH are described in, for example, International Publication No. 2010 / 013483. Examples of commercially available products of P3HB3HH include "Kaneka Biodegradable Polymer Green Planet" (registered trademark) of Kaneka Corporation.

[0024] From the viewpoints such as being difficult to adhere to the cooling roll during the production of the film or laminate and being easy to produce a molded product (hereinafter, may also be referred to as "secondary processed product") obtained by molding the film or laminate according to the present invention, the average content ratio of each constituent monomer in P3HB3HH is preferably 3HB / 3HH = 97 to 80 / 3 to 20 (mol% / mol%), more preferably 3HB / 3HH = 95 to 75 / 5 to 15 (mol% / mol%), and even more preferably 3HB / 3HH = 92 to 78 / 7 to 13 (mol% / mol%).

[0025] The average content ratio of each constituent in P3HB3HH can be determined by methods known to those skilled in the art, such as the method described in paragraph

[0047] of International Publication 2013 / 147139 or by NMR measurement. The average content ratio means the molar ratio of 3HB and 3HH contained in P3HB3HH. When P3HB3HH is a mixture containing two types of P3HB3HH, or at least one type of P3HB3HH and P3HB, it means the molar ratio of each monomer contained in the entire mixture.

[0026] As described above, P3HB3HH having an average content ratio of 3 to 20 mol% of 3HH particularly preferably contains at least two types of P3HB3HH in which the content ratios of the constituent monomers are different from each other, and it is also preferable to contain at least one type of P3HB3HH and P3HB.

[0027] When composed of two or more types of P3HB3HH, it is preferable to include both highly crystalline P3HB3HH and low-crystalline P3HB3HH. Alternatively, P3HB may be blended in place of highly crystalline P3HB3HH, or highly crystalline P3HB3HH and P3HB may be used in combination. With such a formulation, especially when laminating to a substrate to manufacture a laminate, the highly crystalline P3HB3HH, which is prone to crystallization, suppresses adhesion to the cooling roll, while the low-crystalline P3HB3HH exhibits hot tack properties, thereby further improving the adhesive strength to the substrate.

[0028] The ratio of 3HH to the total of 3HB and 3HH in the highly crystalline P3HB3HH is preferably 3 mol% or less, more preferably 2 mol% or less, and even more preferably 1 mol% or less. Furthermore, the ratio of 3HH to the total of 3HB and 3HH in the low crystalline P3HB3HH is preferably 10 to 40 mol%, and more preferably 15 to 30 mol%.

[0029] The amount of the highly crystalline P3HB3HH or P3HB blended is not particularly limited, but is preferably 1 to 60% by weight relative to the P3HB resin (B), more preferably 2 to 50% by weight, and even more preferably 4 to 15% by weight.

[0030] In the present invention, when a blend of two or more P3HB resins is used, the method for obtaining the blend is not particularly limited. The blend may be obtained by microbial production or by chemical synthesis. Alternatively, the blend may be obtained by melting and kneading the two or more resins using an extruder, kneader, Banbury mixer, rolls, etc., or by dissolving the two or more resins in a solvent, mixing, and drying them.

[0031] The weight-average molecular weight (hereinafter sometimes referred to as Mw) of the P3HB resin used in the present invention is not particularly limited, but is preferably between 100,000 and 2,500,000, more preferably between 150,000 and 2,000,000, even more preferably between 200,000 and 1,000,000, and particularly desirable between 300,000 and 800,000. If the weight-average molecular weight is less than 100,000, the mechanical properties may be inferior, and if it exceeds 2,500,000, molding and processing may become difficult. In this application, the weight-average molecular weight of the P3HB resin can be determined by gel permeation chromatography (GPC) (for example, "Shodex GPC-101" manufactured by Showa Denko Corporation), using polystyrene gel (for example, "Shodex K-804" manufactured by Showa Denko Corporation) as the column and chloroform as the mobile phase, and expressed as the molecular weight in terms of polystyrene.

[0032] (Other resin components) In the manufacturing method of the present invention, one or more biodegradable resins other than the P3HB resin may be mixed with the P3HB resin, to the extent that the effects of the present invention are not impaired, such as aliphatic polyester resins such as polybutylene succinate adipate, polybutylene succinate, and polylactic acid, or aliphatic aromatic polyester resins such as polybutylene adipate terephthalate.

[0033] (Additives) In the manufacturing method of the present invention, additives such as lubricants and inorganic fillers can be mixed with the P3HB resin, to the extent that they do not impair the effects of the present invention.

[0034] Examples of lubricants include saturated or unsaturated fatty acid amides such as palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, and erucic acid amide, as well as aliphatic amide compounds such as alkylene fatty acid amides such as methylenebis-stearic acid amide and methylenebis-stearic acid amide, and pentaerythritol.

[0035] Examples of inorganic fillers include talc, calcium carbonate, mica, silica, clay, kaolin, titanium dioxide, alumina, and zeolite, all of which have an average particle size of 0.5 μm or more.

[0036] The amount of lubricant added is preferably 0.1 to 2 parts by weight, and more preferably 0.2 to 1 part by weight, per 100 parts by weight of the total of the P3HB resin and other resin components. By adding 0.1 parts by weight or more, the peelability improvement effect due to the addition of lubricant can be obtained. Conversely, if the amount exceeds 2 parts by weight, the lubricant bleeds out during pressing and adheres to the cooling roll, making it difficult to perform continuous processing for long periods of time.

[0037] The amount of the inorganic filler is preferably 0.5 to 5 parts by weight, and more preferably 1 to 3 parts by weight, per 100 parts by weight of the P3HB resin (B). By adding 0.5 parts by weight or more, the effect of improving release properties due to the inorganic filler can be obtained. Conversely, if the amount exceeds 5 parts by weight, cracks may easily occur in the P3HB resin layer of the film or laminate.

[0038] [Substrate in laminates] The base material layer, such as paper, that can be used in the present invention is not particularly limited as long as it is biodegradable, and is acceptable as long as a resin layer can be formed on one or both sides thereof.

[0039] Specific examples include kraft paper, cup paper, fine paper, coated paper, tissue paper, glassine paper, cardboard, cellophane, cellulose ester, etc., and the type of base material layer should be selected according to the application of the laminate. Furthermore, the surface of the base material may be subjected to surface treatments such as corona treatment, ozone treatment, plasma treatment, flame treatment, anchor coating treatment, oxygen barrier coating, and water vapor barrier coating. These surface treatments may be performed individually or in combination. A base material with a P3HB resin pre-coated on one or both sides can be used, and the thickness of the pre-coat layer should be greater than 0 μm, preferably 0.1 μm to 100 μm, and more preferably 0.9 μm to 50 μm, in order to improve the adhesion between the base material and the P3HB resin layer.

[0040] [Cooling Roll] In this invention, the cooling roll refers to a temperature-controlled roll that first comes into contact with the resin raw material containing molten P3HB resin after it is discharged from the extruder during the manufacture of a film or laminate.

[0041] In the present invention, a cooling roll is used in which the absolute value of the difference (d2 - d1) between the contact angle (d1) of the film surface and the contact angle (d2) of the cooling roll surface is 25° or more and 65° or less. In particular, when the production speed (line speed in the case of continuous production) is increased or the film thickness is increased, the absolute value of (d2 - d1) is preferably 40° or more and less than 65°, and more preferably 45° or more and 60° or less, in order to prevent the film from sticking to the cooling roll.

[0042] Furthermore, the contact angle (d1) of the film is the contact angle of the film surface measured using a film manufactured from the resin raw material used in the present invention, and the contact angle (d2) of the cooling roll surface is the contact angle measured when the roll is not temperature-controlled. In this invention, the contact angles of the film surface and the roll surface can be measured in accordance with the plastics - film and sheet - wetting tension test method specified in JIS K6768.

[0043] In this invention, the contact angle refers to the contact angle measured using a wettability tension measuring mixture (manufactured by Fujifilm Wako Pure Chemical Industries Ltd., wettability tension testing mixture) with wetting tensions of 30 mN / m, 40 mN / m, and 50 mN / m.

[0044] In the present invention, when increasing the production speed (line speed in the case of continuous production), or increasing the film thickness or the resin layer in the laminate, it is preferable that the contact angle (d2) of the cooling roll surface is higher than the contact angle (d1) of the film surface, in that the film (resin layer) is less likely to stick to the cooling roll.

[0045] The method for setting the absolute value of the difference between contact angle (d1) and contact angle (d2) within the range of the present invention is not particularly limited as long as the contact angle of the film surface or the cooling roll surface can be adjusted so that it falls within the range. For example, a method of adjusting the contact angle (d2) of the cooling roll according to the contact angle (d1) of the film surface is preferred.

[0046] Methods for adjusting the contact angle (d2) of the cooling roll surface include, for example, selecting the roll material, applying corona treatment, ozone treatment, or plasma treatment to the roll surface, shaping treatment to create fine irregularities on the surface, or fixing treatment of a coating material containing a resin component. These methods may be performed individually or in combination. In particular, shaping treatment and fixing treatment of a coating material containing a resin component are preferred because they allow for easy adjustment of the surface contact angle value and maintain the contact angle value for a long period of time. Combining shaping treatment and fixing treatment is especially preferable. A specific method for combining shaping treatment and fixing treatment is, for example, the method described in Japanese Patent Publication No. 10-6444.

[0047] The cooling roll according to the present invention preferably has a surface roughness (Ra) of 0.1 μm to 15 μm formed by shaping treatment, more preferably 0.3 μm to 13.5 μm, and particularly preferably 0.5 μm to 12 μm. By setting the surface roughness within the above range, it tends to prevent the resin containing P3HB-based resin from sticking to the roll.

[0048] The cooling roll according to the present invention preferably has at least one material, either a fluororesin-based material or a silicone resin-based material, fixed to it. Fixing the above material tends to prevent the resin, including P3HB-based resin, from sticking to the roll.

[0049] (Film manufacturing method) A method for manufacturing a film according to one embodiment of the present invention includes the steps of melting a resin raw material containing the P3HB resin in an extruder, forming it into a film, and cooling the formed film with a cooling roll. In the manufacturing method of the present invention, the cooling roll that comes into contact with the film containing at least a P3HB resin has a surface contact angle (d2) value that is characteristic of the present invention. The film formation can be carried out using a general film forming method, but may also be carried out by, for example, a calendering method in which molten resin material is sandwiched between two or more cooling rolls, an inflation molding method in which molten resin material is extruded from a circular die as a tubular film and air is introduced inside to inflate it, or by extruding molten resin material from a T-die, i.e., an extrusion molding method. For producing a film with uniform thickness, the extrusion molding method is preferred.

[0050] Furthermore, in the manufacturing method of the present invention, the temperature of the cooling roll is preferably set to 40 to 100°C in order to allow the crystallization of the P3HB resin to progress to a certain extent and to avoid suppressing adhesion to the cooling roll.

[0051] The thickness of the film produced by the manufacturing method of the present invention is not particularly limited, but from the viewpoint of ensuring sufficient flexibility of the film to prevent it from sticking to the cooling roll, it is preferably 5 to 300 μm, more preferably 10 to 200 μm, and most preferably 25 μm to 60 μm.

[0052] (Method of manufacturing a laminate) A method for manufacturing a laminate according to one embodiment of the present invention will be described using as an example a method for manufacturing a laminate composed of a substrate such as paper and a resin layer (laminate layer) containing a P3HB-based resin formed on one side thereof by an extrusion lamination method, but the present invention is not limited thereto. The manufacturing method for laminates by the extrusion lamination method involves extruding a resin raw material containing molten P3HB resin from a T-type die or the like, bringing the molten extruded resin into contact with a substrate separately fed from a substrate feeding roll, and laminating the substrate and resin layers to form a layered structure. Subsequently, the formed laminate is sandwiched between a pair of pressure rolls, at least one of which is temperature-controlled, and the substrate layer and resin layer constituting the laminate are pressed together.

[0053] In this invention, the bonding is performed using a cooling method (bonding at a temperature lower than the temperature of the molten resin raw material), and at least one bonding roll in contact with the resin layer is composed of a cooling roll according to this invention.

[0054] The extrusion lamination method described above involves cooling and pressing a resin layer, made from molten resin raw material, onto a substrate, and immediately peeling the resin layer off the cooling roll, and is performed continuously. Therefore, in conventional methods, when P3HB resin is used as the resin material, the resin layer does not peel off smoothly from the cooling roll, and a phenomenon in which the laminate layer temporarily adheres to the cooling roll is likely to occur. As a result, when force is applied to the adhered area when peeling from the roll, a problem that causes clouding (fine irregularities) on the surface of the laminate layer occurs particularly prominently at that area. However, by applying a cooling roll having the surface contact angle (d2) value according to the present invention, it is possible to improve the peelability from the cooling roll and manufacture a laminate with a good surface condition of the resin layer.

[0055] Furthermore, in the manufacturing method of the laminate by the extrusion lamination method, the temperature of the cooling roll is preferably set to 40 to 100°C in order to allow the crystallization of the P3HB resin to progress to a certain extent and to suppress adhesion to the cooling roll.

[0056] Other lamination methods include the thermal lamination method, in which a pre-made resin film is heated and pressed onto a paper substrate. In this method as well, the material in contact with the resin surface containing the P3HB resin should be a pressing material having the contact angle (d2) value characteristic of the present invention. In the laminate produced by the manufacturing method of the present invention, the thickness of the resin layer containing P3HB resin (or each resin layer if the laminate has two or more resin layers) is not particularly limited, but from the viewpoint of preventing water absorption into the paper while ensuring sufficient flexibility, it is preferably 5 to 300 μm, and more preferably 10 to 100 μm.

[0057] [Molded body] Because the film or laminate produced by the manufacturing method of the present invention has a good surface condition, the molded products produced using the film or laminate produced by the present invention are not particularly limited, but examples include paper cups, paper bags, cartons, trays, and interior wallpaper. [Examples]

[0058] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited in any way to these examples.

[0059] (Resin materials used) Resin raw material: Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [Manufactured by Kaneka, Kaneka Biodegradable Polymer GreenPlanet] TM ,X136)

[0060] (Removability from cooling rolls) The degree of adhesion of P3HB resin to the cooling roll was observed. The evaluation criteria were as follows.

[0061] <Rating> ◎: When molded at a rate of 4.0 m / min or higher, the film (resin layer) does not stick to the roll surface, allowing for continuous operation, and no irregularities are observed on the surface of the film (resin layer). ○: When molded at 4.0 m / min, the film (resin layer) is difficult to peel off from the cooling roll, and there are cloudy, uneven areas on part of the film (resin layer). However, when molded at 2.0 m / min, the film (resin layer) does not stick to the roll surface, allowing for continuous operation, and no irregularities are observed on the surface of the film (resin layer). ×: Even when molding is performed at a rate of less than 2.0 m / min, the film (resin layer) adheres to the cooling roll, making continuous operation impossible without manual assistance to remove it.

[0062] (Measurement of contact angle) The contact angle was measured in accordance with the "Plastics - Films and Sheets - Wetting Tension Test Method" specified in JIS K6768, using wetting tension test mixtures No. 30.0 (30 mN / m), No. 40.0 (40 mN / m), and No. 50.0 (50 mN / m) (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0063] (Example 1) Using a UNA310X10 (manufactured by Toshiko Co., Ltd.) as the cooling roll, resin pellets 1 (X136) were processed using a single-screw extruder (Toyo Seiki Seisakusho 20C200 type laboplast mill) equipped with a T-type die with a width of 150 mm and a lip opening width of 0.25 mm. The cylinder temperature was set to 145-165°C and the T-type die to 175°C, and a laminator (roll diameter 100 mm) with the cooling roll temperature controlled to 60°C was used to produce a basis weight of 200 g / m². 2 A laminate was obtained by laminating one side of the cup base paper with a resin layer thickness of 30 μm. When the laminate was manufactured at a line speed of 4.0 m / min, no adhesion of the resin layer to the cooling roll was observed. No clouding was observed in the resin layer of the obtained laminate. The results are shown in Table 1.

[0064] [Examples 2-8, Comparative Examples 1 and 2] The cooling roll peelability was evaluated in the same manner as in Example 1, except that the cooling rolls shown in Table 1 were used. The results are shown in Table 1.

[0065] [Table 1] 〔result〕 Table 1 shows that the example demonstrated better peelability of the cooling roll compared to the comparative example.

Claims

1. A method for producing a film containing a poly(3-hydroxybutyrate) resin, The process involves melting the resin raw material containing the aforementioned poly(3-hydroxybutyrate) resin in an extruder and then forming it into a film, and The process includes bringing the film into contact with a cooling roll to cool it, A cooling roll is used in which the absolute value of the difference (d2-d1) between the contact angle (d1) of the surface of the film and the contact angle (d2) of the surface of the cooling roll that is in contact with at least the film is 25° or more and 65° or less. A film manufacturing method wherein the contact angles (d1) and (d2) are contact angles measured using a mixed solution for measuring wet tension with wet tensions of 30 mN / m, 40 mN / m, and 50 mN / m, in accordance with the "Plastics - Films and Sheets - Wetting Tension Test Method" specified in JIS K6768.

2. The method for manufacturing a film according to claim 1, wherein the contact angle (d2) is higher than the contact angle (d1).

3. The method for manufacturing a film according to claim 1 or 2, wherein the absolute value of the difference in contact angles (d2 - d1) is 40° or more and less than 65°.

4. The method for manufacturing a film according to any one of claims 1 to 3, wherein the cooling roll is made to which a coating material containing a resin component is fixed.

5. The method for producing a film according to claim 4, wherein the coating material contains at least one selected from the group consisting of fluororesin-based materials and silicone resin-based materials.

6. A method for producing a laminate having a resin containing a poly(3-hydroxybutyrate) resin as the outermost layer, The process involves melting the resin containing the aforementioned poly(3-hydroxybutyrate) resin in an extruder and then forming it into a film, and The process includes laminating the film onto the surface of a substrate while the film is in contact with a cooling roll, A cooling roll is used in which the absolute value of the difference (d2-d1) between the contact angle (d1) of the surface of the film and the contact angle (d2) of the surface of the cooling roll that is in contact with at least the film is 25° or more and 65° or less. A method for manufacturing a laminate, wherein the contact angles (d1) and (d2) are contact angles measured using a mixed solution for measuring wetting tension with wetting tensions of 30 mN / m, 40 mN / m, and 50 mN / m, in accordance with the "Plastics - Films and Sheets - Wetting Tension Test Method" specified in JIS K6768.

7. The method for manufacturing a laminate according to claim 6, wherein the contact angle (d2) is higher than the contact angle (d1).

8. The method for manufacturing a laminate according to claim 6 or 7, wherein the absolute value of the difference in the contact angles (d2-d1) is 40° or more and less than 65°.

9. The method for manufacturing a laminate according to any one of claims 6 to 8, wherein the cooling roll is made to which a coating material containing a resin component is fixed.

10. The method for manufacturing a laminate according to claim 9, wherein the coating material contains at least one selected from the group consisting of fluororesin-based materials and silicone resin-based materials.

Images