Molded products, release films and their applications

Abstract

The present invention aims to provide a molded product made of polyester resin using marine plastic waste, while also providing a molded product with excellent handling properties and shape recovery. [Solution] The present invention provides a molded article containing recycled polyester resin, wherein the recycled polyester resin comprises granular material with a particle size of 1000 μm or less, comprising 4250 particles / m². 2 The above applies to molded products. The recycled polyester resin is preferably made from recycled marine plastic.

Description

[Technical Field]

[0001] The present invention relates to molded articles, release films, polyester films with ceramic green sheets, the use of ceramic green sheets as supports, and methods for manufacturing ceramic green sheets. [Background technology]

[0002] Polyester films, such as polyethylene terephthalate film and polyethylene naphthalate film, possess excellent properties in terms of mechanical properties, dimensional stability, flatness, heat resistance, chemical resistance, and optical properties, and are cost-effective, making them suitable for a wide range of applications. For example, polyester films are ideally used in various applications, such as release films for forming green sheets for multilayer ceramic capacitors, substrates for releasing interlayer insulating resins, and substrates for dry film resists, taking advantage of the smoothness of their surface.

[0003] Incidentally, in recent years, due to growing environmental concerns and the need for resource conservation, the recycling of used PET bottles and other PET containers has been carried out, and methods for utilizing them have attracted attention. For example, Patent Documents 1 to 3 disclose polyethylene terephthalate films made of a polyester resin composition containing recycled raw materials derived from PET bottles, wherein the recycled raw materials are mechanically recycled polyester resin and / or chemically recycled polyester resin.

[0004] In recent years, marine plastic pollution has become a major problem. Marine plastic refers to plastic waste that is discarded and left unattended on land, flows into the sea through rivers and other waterways, and accumulates on beaches and seabeds, or floats in the water. The origins of marine plastic are diverse, including food trays, flower pots, detergent containers, packaging for sweets and other items, and packing bands, but more than half of it is PET bottles.

[0005] For example, Patent Document 4 discloses a method for manufacturing resin molded articles, characterized in that a plastic material containing a thermoplastic resin is placed in a mold and the mold is heat-pressed to produce the resin molded article, and the use of marine plastic waste as the plastic material containing a thermoplastic resin is being considered. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-56047 [Patent Document 2] Japanese Patent Publication No. 2023-35545 [Patent Document 3] Japanese Patent Publication No. 2023-36069 [Patent Document 4] Japanese Patent Publication No. 2022-060286 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the prior art, the production of polyester resin molded products (e.g., polyester films) using marine plastic waste had not been specifically considered, nor had the physical properties of the resulting molded products been evaluated or their applications examined. In this regard, the present inventors conducted an investigation and found that there is room for improvement in terms of handling properties and shape recovery properties of polyester resin molded products obtained using the prior art.

[0008] Therefore, the inventors of this invention proceeded with research with the aim of manufacturing polyester resin molded products using marine plastic waste, and providing molded products with excellent handling properties and shape recovery. [Means for solving the problem]

[0009] Examples of specific embodiments of the present invention are shown below.

[0010] [1] A molded article containing recycled polyester resin, The recycled polyester resin has a particle size of 1000 μm or less, with a density of 4250 particles / m². 2 Molded product including the above. [2] The molded article described in [1], wherein the recycled polyester resin is made from recycled marine plastic. [3] A molded article as described in [1] or [2], which is a film. [4] A molded article according to any one of [1] to [3], wherein the arithmetic mean height (Sa) of at least one surface is 15 nm or less. [5] A molded article according to any one of [1] to [4], wherein the maximum peak height (Sp) of at least one surface is 150 nm or less. [6] A molded article according to any one of [3] to [5], wherein the film is a laminated film having two or more layers, and the surface layer of the laminated film contains recycled polyester resin. [7] A molded article according to any one of [3] to [6], wherein the film is a laminated film having a surface layer, an intermediate layer and a back layer, and the intermediate layer contains recycled polyester resin. [8] A molded article according to any one of [3] to [7], wherein the film is a laminated film having a surface layer, an intermediate layer and a back layer, and the surface layer and / or back layer contains recycled polyester resin. [9] The molded article according to [7] or [8], wherein the thickness of the surface layer is 1 to 8 μm.

[10] A molded article according to any one of [7] to [9], wherein the surface layer is substantially free of particles.

[11] A molded article according to any one of [7] to

[10] , wherein the thickness of the intermediate layer is 50 to 93% of the total film thickness.

[12] A molded product as described in any of [1] to

[11] , wherein the air leakage index is 6500 seconds or less.

[13] A molded product as described in any of [1] to

[12] , wherein the reduction rate of the air leakage index calculated by the following formula is 18% or more. Air leakage index reduction rate (%) = 100 - Air leakage index of target polyester film / Air leakage index of virgin polyester film × 100

[14] A molded article according to any of [1] to

[13] , wherein the elastic deformation power is 49% or more.

[15] A molded article according to any one of [1] to

[14] , wherein the content of isophthalic acid units relative to 100 mol% of the total dicarboxylic acid units constituting the polyester resin contained in the recycled polyester resin is 0.01 to 5 mol%.

[16] A molded article according to any of [1] to

[15] , wherein the temperature rise recrystallization temperature (Tc) is 145°C or lower.

[17] A molded article according to any of [1] to

[16] , wherein the melting peak temperature (Tm) is 254.1°C or less.

[18] A molded article according to any one of [1] to

[17] , further comprising recycled polyester resin obtained by recycling polyester film.

[19] A molded article according to any one of [7] to

[18] , further having a coating layer on the surface layer.

[20] The molded article according to

[19] , wherein the total thickness of the surface layer and the coating layer is 1 to 8 μm.

[21] A molded article according to any one of [1] to

[20] , wherein the intrinsic viscosity of the recycled polyester resin is 0.70 dL / g or more.

[22] A molded article according to any one of [1] to

[21] , used as a support for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor.

[23] A release film having a release layer further on at least one side of the molded article described in any of [1] to

[22] .

[24] A ceramic green sheet-coated film, which is a molded product described in any of [1] to

[22] with a ceramic green sheet laminated onto it.

[25] Use of any of the molded products described in [1] to

[22] as a support for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors.

[26] A method for manufacturing a ceramic green sheet, comprising the step of coating at least one side of a molded product described in any of [1] to

[22] with a ceramic slurry containing a ceramic component. [Effects of the Invention]

[0011] According to the present invention, it is possible to manufacture polyester resin molded products using marine plastic waste, and to provide molded products with excellent handling properties and shape recovery. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below. The following description may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, when "X~Y" (where X and Y are any numbers) is used, unless otherwise specified, it includes the meaning of "X or greater and Y or less," as well as "preferably greater than X" or "preferably less than Y." Also, when "X or greater" (where X is any number) or "Y or less" (where Y is any number) is used, it also includes the intention that "preferably greater than X" or "preferably less than Y." In the following description, "film" and "sheet" are not clearly distinguished, and the term "film" may include "sheet," and vice versa.

[0013] (molded product) This embodiment is a molded article containing recycled polyester resin, wherein the recycled polyester resin comprises granular material with a particle size of 1000 μm or less, with a particle size of 4250 particles / m². 2 The present invention relates to molded articles including the above. In this embodiment, the recycled polyester resin is preferably recycled from marine plastic, and the recycled polyester resin obtained by recycling marine plastic contains 4,250 granular particles with a particle size of 1,000 μm or less per square meter. 2 It is preferable that the above are included. In this embodiment, by using such recycled polyester resin, it is possible to manufacture polyester resin molded products by effectively utilizing marine plastic waste, and to provide molded products with excellent handling properties or shape recovery properties.

[0014] In preferred embodiments, the elastic deformation power of the resulting molded product can be increased. A high elastic deformation power means that even if the molded product deforms, it is easier for it to return to its original shape. Therefore, the shape of the molded product is easier to maintain during molding, and as a result, a molded product with excellent design and shape recovery can be obtained. Furthermore, when the elastic deformation power is high, it is also preferably used as a support (substrate) for ceramic green sheets. For example, when polyester film is used as a support (substrate) for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors, a cutting blade may be used to cut the ceramic green sheets laminated on the support in order to peel them off. When the polyester film is cut, it elastically deforms appropriately and then returns to its original shape, making it easier for the edges (cut parts) of the ceramic green sheets to separate from the polyester film, and as a result, a good gap (float) can be formed between the two. This gap (float) can then be effectively used as a starting point when peeling off the ceramic green sheet. In this way, by using polyester film as a support (substrate) for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors, the peelability of the ceramic green sheets can be improved.

[0015] If the molded product is a polyester film, the elastic deformation power of the polyester film is (η it ) is preferably 49% or more, more preferably 50% or more, even more preferably 52% or more, even more preferably 54% or more, particularly preferably more than 55%, and most preferably 56% or more. Elastic deformation power (η) of polyester film it The upper limit of ) is not particularly limited, but it may be 60% or less, or 58% or less. Furthermore, if the polyester film has a multilayer structure, it is preferable that the elastic deformation power of the surface layer of the polyester film be within the above range.

[0016] Elastic deformation power of polyester film (η it) is calculated by the following formula based on the physical quantity measured by the nanoindentation method (conforming to ISO14577). Specifically, after covering the back layer side of a polyester film (1.5 cm × 1.5 cm) as a sample film on a slide glass (S1112, manufactured by Matsunami Glass Industry Co., Ltd.) with the adhesive surface and curing it, the slide glass with the sample film is fixed to the sample stage of a hardness tester (Dynamic Ultra Microhardness Tester (DUH-211S, manufactured by Shimadzu Corporation)), and then a load-unload test is performed on the surface (surface layer) of the sample film, and the elastic deformation work rate (η it ) is obtained. Wtotal = Wplast + Welast (N·m) (Wtotal = total deformation work (N·m), Wplast = plastic deformation work (N·m), Welast = elastic deformation work (N·m)) η it =(Welast / Wtotal) × 100 (%) The following conditions can be adopted as the measurement conditions. Indenter used: Regular triangular pyramid indenter made of diamond (included angle between edges: 115) Measurement mode: Load-unload test Test force: 20.00 mN Minimum test force: 0.20 mN Load speed: 0.1464 mN / sec Load holding time: 0 sec Unload holding time: 0 sec Measurement atmosphere: 23 ± 2°C, relative humidity 50 ± 5%

[0017] Also, in another preferred embodiment, 4250 particles with a particle size of 1000 μm or less per m 2By using recycled polyester resin containing the above-mentioned properties, the air leakage index of the resulting molded product can be reduced. When the molded product is a polyester film, the air leakage index of the polyester film is preferably 6500 seconds or less, more preferably 6000 seconds or less, and even more preferably 5500 seconds or less. The lower limit of the air leakage index is not particularly limited, but for example, it is preferably 100 seconds or more, and may be 300 seconds or more. The air leakage index of the polyester film is measured using a Digibec smoothness tester (Toyo Seiki Co., Ltd., "DB-2") in accordance with JIS P8119, under an atmosphere of 23°C and 50% relative humidity. The pressure of the pressurizing device is 100kPa, and a vacuum container with a volume of 38ml is used. The time it takes for 1mL of air to flow, i.e., the time (seconds) until the pressure inside the container changes from 50.7kPa to 48.0kPa, is measured, and 10 times the obtained number of seconds is taken as the air leakage index. A sample size of polyester film is set to 70 mm square. Twenty sheets of film are stacked so that the front and back sides overlap to form a test laminated film. A 5 mm diameter hole is made in the center of this test laminated film, and the air leakage index is measured. In this specification, a higher air leakage index value indicates that it takes longer for air to leak through the gaps between the films, meaning that the films are in closer contact with each other. Therefore, an air leakage index below the above upper limit means that there are adequate gaps between the films, which can improve the slipperiness when winding the polyester film into a roll and reduce the risk of wrinkle formation when the film is rolled.

[0018] The air leakage index reduction rate of the polyester film, calculated using the following formula, is preferably 18% or higher, more preferably 20% or higher, even more preferably 25% or higher, even more preferably 30% or higher, and even more preferably 35% or higher. The upper limit of the air leakage index reduction rate is not particularly limited, but may be, for example, 90%, 80%, or 70%. Air leakage index reduction rate (%) = 100 - Air leakage index of target release film / Air leakage index of virgin polyester film × 100 In the above formula, "virgin polyester film" refers to a film constructed by replacing all of the recycled polyester resin contained in the polyester film with virgin polyester resin (non-recycled polyester resin). A reduction rate of the air leakage index being above the lower limit means that there is an appropriate gap between the films, which improves the slipperiness when winding the release film into a roll and reduces the risk of wrinkle formation when the film is rolled up.

[0019] In this embodiment, the amount of granular material with a particle size of 1000 μm or less is 4250 pieces / m² relative to the total mass of the resin components contained in the molded product. 2 The content of the recycled polyester resin, including the above, is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and may be 20% by mass or more, 25% by mass or more, 30% by mass or more, or 35% by mass or more. The upper limit of the content of the recycled polyester resin is not particularly limited and may be 100% by mass, 95% by mass, 90% by mass, 80% by mass or 70% by mass. Thus, in this embodiment, a high proportion of recycled polyester resin can be included. By forming such a molded product, for example, CO2 emissions can be reduced, and the burden on the environment can be reduced.

[0020] In this embodiment, the content ratio of recycled polyester resin derived from marine plastics to the total mass of resin components contained in the molded article is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and may be 20% by mass or more, 25% by mass or more, 30% by mass or more, or 35% by mass or more. The upper limit of the content ratio of recycled polyester resin derived from marine plastics is not particularly limited and may be 100% by mass, 95% by mass, 90% by mass, 80% by mass or 70% by mass. Thus, in this embodiment, a high proportion of recycled polyester resin derived from marine plastics can be included. By forming such a molded article, it is possible to contribute to the reduction of marine plastic waste.

[0021] In this embodiment, the molded article may further contain recycled polyester resin derived from marine plastics, in addition to recycled polyester resin derived from marine plastics, which is recycled from polyester products not derived from marine plastics (e.g., PET bottles and polyester films). For example, the content of recycled polyester resin derived from polyester films not derived from marine plastics is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total mass of the resin components contained in the molded article.

[0022] Examples of molded articles in this embodiment include plastic trays, plastic containers, plastic tableware, housings for various electronic devices, furniture, exterior and interior materials, automobile parts, toys, eyeglass frames, films, sheets, bottles, tubes, fibers, clothing, etc. The molding method for the molded article is not particularly limited, but methods such as injection molding, extrusion molding, blow molding, and vacuum forming can be used. Among these, it is preferable that the molded article be formed by injection molding or extrusion molding. In particular, it is preferable that the molded article be a film, and especially preferable that it be a polyester film.

[0023] When the molded product is a polyester film, the arithmetic mean height (Sa) of at least one surface of the polyester film is preferably 15 nm or less, more preferably 10 nm or less, even more preferably 8 nm or less, even more preferably 6 nm or less, and particularly preferably 4 nm or less. Furthermore, the arithmetic mean height (Sa) of at least one surface of the polyester film is preferably 0.2 nm or more, more preferably 0.4 nm or more, and even more preferably 0.6 nm or more. Thus, in this embodiment, 4250 granular materials with a particle size of 1000 μm or less are used per square meter. 2 Even when using recycled polyester resin containing the above-mentioned properties, a polyester film with excellent surface smoothness can be obtained. On the other hand, it is preferable that the arithmetic mean height (Sa) of the polyester film be equal to or greater than the lower limit value, and that it be given a roughness of a predetermined amount or more. This provides the rough surface necessary to improve the handling of the polyester film and reduces the air leakage index of the polyester film. As a result, the polyester film can exhibit appropriate slipperiness and its handling performance is improved.

[0024] The maximum peak height (Sp) of at least one surface of the polyester film is preferably 150 nm or less, more preferably 120 nm or less, even more preferably 100 nm or less, even more preferably 80 nm or less, and particularly preferably 60 nm or less. Furthermore, the maximum peak height (Sp) of at least one surface of the polyester film is preferably 5 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. Thus, in this embodiment, 4250 granular materials with a particle size of 1000 μm or less are used per m². 2 Even when using recycled polyester resin containing the above, a polyester film with excellent surface smoothness can be obtained. On the other hand, in this embodiment, 4250 granular particles with a particle size of 1000 μm or less are used per square meter. 2 By using recycled polyester resin containing the above-mentioned properties, it is possible to impart appropriate roughness to the polyester film, thereby obtaining a polyester film with excellent handling properties.

[0025] The temperature at which the polyester film undergoes recrystallization (Tc) is preferably 145°C or lower, more preferably 140°C or lower, even more preferably 138°C or lower, and particularly preferably 136°C or lower. The lower limit of the temperature at which the polyester film undergoes recrystallization (Tc) is not particularly limited, but for example, it is preferably 110°C or higher, may be 120°C or higher, or 125°C or higher.

[0026] The peak melting temperature (Tm) of the polyester film is preferably 270°C or lower, more preferably 260°C or lower, even more preferably 256°C or lower, and particularly preferably 254.1°C or lower. Furthermore, the peak melting temperature (Tm) of the polyester film is preferably 230°C or higher, more preferably 235°C or higher, even more preferably 240°C or higher, and particularly preferably 245°C or higher.

[0027] The peak melting heat (ΔHm) of the polyester film is preferably 18 J / g or more, more preferably 22 J / g or more, even more preferably 25 J / g or more, and even more preferably 27 J / g or more. Furthermore, the peak melting heat (ΔHm) of the release film is preferably 50 J / g or less, more preferably 45 J / g or less, and even more preferably 42 J / g or less.

[0028] The temperature at which the polyester film undergoes heating to recrystallize (Tc), the melting peak temperature (Tm), and the melting peak heat quantity (ΔHm) can be measured, for example, using a differential scanning calorimeter (DSC60) manufactured by Shimadzu Corporation. The measurement conditions are as follows: (1) The peak top temperature of the endothermic curve for crystal melting is defined as the melting peak temperature (Tm), the peak heat quantity of the endothermic curve for crystal melting is defined as the melting peak heat quantity (ΔHm), and (5) The peak top temperature of the exothermic curve for heating to recrystallize is defined as the heating to recrystallize temperature (Tc). (1) Increase the temperature from 20°C to 300°C at a rate of 10°C / min. (2) Hold at 300°C for 5 minutes (3) Cool down to 20°C at 600°C / min (4) Hold at 20°C for 5 minutes (5) Increase the temperature from 20°C to 300°C at a rate of 10°C / min. (6) Hold at 300°C for 5 minutes (7) Cool down to 20°C at 600°C / min

[0029] Recycled polyester resin obtained by recycling materials such as PET bottles is generally a polyester resin recycled through processes such as crushing collected used PET bottles, removing foreign matter by washing, and decontamination by high-temperature treatment. As such, it tends to have different recrystallization temperatures than polyester resins derived from fossil fuels. If the recrystallization temperature (Tc), melting peak temperature (Tm), and melting peak heat (ΔHm) of a polyester film are within the above range, it indicates that the polyester film contains recycled polyester resin. Furthermore, if the recrystallization temperature is within the above range, crystallization begins from the lower temperature side when the resin is in a molten state, which can improve the crystallinity of the film. In addition, controlling the recrystallization temperature within the above range has the advantage of making it easier to adjust the shrinkage rate and elastic deformation power of the film.

[0030] The gas density of the polyester film is 1.4000 g / cm³. 3 Preferably, it is 1.4015 g / cm³ or more. 3 It is more preferable that the concentration be greater than or equal to 1.4020 g / cm³. 3 It is even more preferable that the above is true. Furthermore, the density of the polyester film is 1.4100 g / cm³. 3 Preferably, it is 1.4075 g / cm³ 3 The following is more preferable: By keeping the gas density of the polyester film within the above range, it is possible to achieve both heat resistance, solvent resistance, and flexibility in the polyester film, and it becomes easier to obtain a polyester film with excellent shape recovery, surface properties, and handling characteristics.

[0031] The tensile strength of the polyester film in the MD direction is preferably 100 MPa or more, more preferably 120 MPa or more, even more preferably 150 MPa or more, even more preferably 170 MPa or more, and particularly preferably 200 MPa or more. Furthermore, the tensile strength of the polyester film in the MD direction may be 450 MPa or less, 400 MPa or less, 350 MPa or less, or 300 MPa or less. The tensile strength of the polyester film in the TD direction is preferably 160 MPa or higher, more preferably 180 MPa or higher, and even more preferably 200 MPa or higher. The tensile strength of the polyester film in the longitudinal direction (TD) may be 400 MPa or lower, 350 MPa or lower, or 300 MPa or lower. Tensile strength refers to the tensile fracture stress as defined in JIS K 7161-1:2014. The measurement is performed under the following conditions: 23°C, 50% relative humidity, a chuck distance of 50 mm between the test specimens, and a tensile speed of 200 mm / min.

[0032] The tensile elongation of the polyester film in the MD direction is preferably 70% or more, more preferably 100% or more, even more preferably 130% or more, even more preferably 160% or more, and particularly preferably 190% or more. Furthermore, the tensile elongation of the polyester film in the longitudinal direction (MD) may be 300% or less, 280% or less, or 260% or less. The tensile elongation of the polyester film in the TD direction is preferably 70% or more, more preferably 85% or more, and even more preferably 100% or more. Furthermore, the tensile elongation of the polyester film in the longitudinal direction (TD) may be 300% or less, 250% or less, or 200% or less. Tensile elongation refers to the tensile fracture elongation (tensile fracture nominal strain) as defined in JIS K 7161-1:2014. The measurement is performed under the following conditions: 23°C, 50% relative humidity, a chuck distance of 50 mm between the test specimens, and a tensile speed of 200 mm / min.

[0033] The overall thickness of the polyester film is not particularly limited as long as it is within the range that allows it to be formed as a film, but from the viewpoint of mechanical strength, handling, and productivity, it is preferably 10 μm or more, more preferably 12 μm or more, and even more preferably 14 μm or more. Furthermore, the overall thickness of the polyester film is preferably 150 μm or less, more preferably 100 μm or less, even more preferably 80 μm or less, even more preferably 50 μm or less, even more preferably 38 μm or less, and particularly preferably 35 μm or less. The total thickness of the polyester film may be, for example, 34 μm or less, or 32 μm or less.

[0034] <Recycled polyester resin> The molded product of this embodiment has 4250 granular particles / m² with a particle size of 1000 μm or less. 2 Recycled polyester resin containing the above (hereinafter referred to as "granular material with a particle size of 1000 μm or less, 4250 pieces / m²") 2 The term "recycled polyester resin containing the above" is sometimes simply referred to as "recycled polyester resin."

[0035] The recycled polyester resin contains granular material, with a particle size of 1000 μm or less, at a density of 4250 particles / m². 2 The above is included. In this specification, granular material refers to gel-like material formed by the aggregation of resin-derived components or foreign matter contained in recycled raw materials. The number of granular materials with a particle size of 1000 μm or less contained in recycled polyester resin is 4500 pieces / m 2 Preferably, the number is 6000 or more, or 6000 / m 2 It is more preferable that the number be greater than or equal to 8000 pieces / m 2 It is even more preferable that the number be greater than or equal to 10,000 pieces / m 2It is even more preferable that the number be greater than or equal to 13,000 / m 2 It is even more preferable that the number be greater than or equal to 15,000 pieces / m 2 It is even more preferable that the number be greater than or equal to 18,000 pieces / m 2 It is even more preferable that the number be greater than or equal to 20,000 pieces / m 2 The above is particularly preferable. Furthermore, the number of granular particles with a particle size of 1000 μm or less contained in the recycled polyester resin should be 50,000 particles / m². 2 Preferably, the following: 40,000 pieces / m 2 It is more preferable that the following be true: 34,000 pieces / m 2 It is even more preferable that the following be the case, 28,000 pieces / m 2 It is even more preferable that the following be the case: In this specification, the particle size of the granules is the average value of the longest diameter and the shortest diameter.

[0036] The recycled polyester resin consists of granular material with a particle size of 25 μm to 1000 μm, with a density of 4250 particles / m². 2 It is preferable that the above be included. Furthermore, the number of granular particles with a particle size of 25 μm or more and 1000 μm or less should be 5000 particles / m². 2 Preferably, the number is 7000 or more, or 7000 / m 2 It is more preferable that the number be greater than or equal to 9000 pieces / m 2 It is even more preferable that the number be greater than or equal to 11,000 / m 2 It is even more preferable that the number be greater than or equal to 13,000 / m 2 It is even more preferable that the number be greater than or equal to 15,000 pieces / m 2 It is even more preferable that the number be greater than or equal to 16,000 / m 2 The above is particularly preferable. The number of granular particles with a particle size of 25 μm or more and 1000 μm or less is 40,000 particles / m². 2 Preferably, the following is true: 30,000 pieces / m 2 It is more preferable that the following be the case, 25,000 pieces / m 2 It is even more preferable that the following conditions be met: 20,000 pieces / m 2 The following is even more preferable:

[0037] Recycled polyester resin is made up of granular material with a particle size of 25 μm or more and less than 50 μm, with a density of 100 to 20,000 particles / m². 2 May contain, 300 to 18,000 pieces / m 2 May contain, 500 to 15,000 pieces / m 2 It may be included, at a rate of 700 to 12,000 pieces / m 2 It may contain 800 to 10,000 of them. Recycled polyester resin is made up of granular material with a particle size of 50 μm to less than 75 μm, with a density of 100 to 10,000 particles / m². 2 May contain, 150-8000 pieces / m 2 It may be included, at a rate of 200-6000 pieces / m 2 It may be included, at a rate of 300-5000 pieces / m 2 It may be included. The recycled polyester resin contained in the intermediate layer consists of granular material with a particle size of 75 μm to less than 100 μm, with a density of 50 to 5000 particles / m². 2 May contain 60-4500 pieces / m 2 May contain 70-4000 pieces / m 2 May contain, 100-3500 pieces / m 2 May contain, 150-3000 pieces / m 2 It may be included. Recycled polyester resin is made up of granular material with a particle size of 100 μm to less than 150 μm, with a density of 50 to 5000 particles / m². 2 May contain, 60-4500 pieces / m 2 It may contain 70 to 4000 particles, and 100 to 3500 particles / m 2 May contain, 150-3000 pieces / m 2 It may be included. Recycled polyester resin is made up of granular material with a particle size of 150 μm or more and less than 200 μm, with a density of 15 to 2000 particles / m². 2 May contain 20-1500 pieces / m 2 May contain 30 to 1000 pieces / m 2 May contain, 40-800 pieces / m 2 It may be included, 50-600 pieces / m 2 It may be included. Recycled polyester resin is made up of granular material with a particle size of 200 μm or more and less than 300 μm, with a density of 15 to 1000 particles / m². 2May contain, 20-800 pieces / m 2 May contain, 30-600 pieces / m 2 May contain, 40-400 pieces / m 2 It may be included. Recycled polyester resin is made up of granular material with a particle size of 300 μm or more and less than 500 μm, with a density of 15 to 1000 particles / m². 2 May contain, 20-800 pieces / m 2 May contain, 30-600 pieces / m 2 May contain, 40-400 pieces / m 2 It may be included. The recycled polyester resin consists of granular material with a particle size of 500 μm or more and less than 1000 μm, with a density of 15 to 1000 particles / m². 2 May contain, 20-800 pieces / m 2 May contain, 30-600 pieces / m 2 May contain, 40-400 pieces / m 2 It may be included.

[0038] The number of granular particles with the aforementioned particle sizes can be measured using a gel counter in the following manner. Specifically, recycled polyester resin is continuously extruded into a sheet with a width of 10 cm and a thickness of 50 μm, while light is shone from above onto a region of approximately 6 cm in the center of the sheet in the width direction, and shadows originating from the granular particles (gel) are photographed from below the sheet with a CCD camera. This allows for the measurement of 1 m 2 The number of granular particles of each particle size present is measured. The gel counter consists of a camera system, an extruder, and a cooling roll unit. For the gel counter, Optical Control Systems' "FS-5 Film Scan (camera system), ME-20 / 26 V2 Measuring Extruder (extruder), CR-7 Chill Roll Unit (cooling roll unit)" can be used. The measurement conditions are as follows. • Cooling roll temperature: 30°C • Extruder cylinder temperature: 295℃ Extruder screw rotation speed: 100 rpm • Sheet thickness: 50μm

[0039] The intrinsic viscosity (IV) of the recycled polyester resin is preferably 0.70 dL / g or higher, more preferably 0.75 dL / g or higher, even more preferably 0.80 dL / g or higher, and even more preferably 0.82 dL / g or higher. Furthermore, the intrinsic viscosity (IV) of the recycled polyester resin is preferably 1.2 dL / g or less, more preferably 1 dL / g or less, even more preferably 0.95 dL / g or less, and even more preferably 0.9 dL / g or less. Setting the intrinsic viscosity of the recycled polyester resin to be above the lower limit above makes it easier to stabilize the film formation, for example, making it easier to control the elastic deformation power to a higher level. On the other hand, setting the intrinsic viscosity to be below the upper limit above is preferable because it makes it easier to suppress excessive pressure increase in the film extruder and easier to suppress the thermal shrinkage rate of the film. The intrinsic viscosity of the recycled polyester resin was determined by accurately weighing 1 g of recycled polyester resin, dissolving it in 100 mL of a phenol / tetrachloroethane mixed solvent (50 / 50 mass ratio), and measuring the viscosity (IV) at 30°C using a viscosity (IV) measuring device.

[0040] Examples of dicarboxylic acid components that make up recycled polyester resins include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfondicarboxylic acid, as well as aliphatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedionic acid, cyclohexanedicarboxylic acid, and their ester derivatives.

[0041] Examples of diol components that make up recycled polyester resin include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-hexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, and spiroglycol.

[0042] When the recycled polyester resin consists of homopolyester, it is preferable that the recycled polyester resin contains structural units derived from aromatic dicarboxylic acid components and structural units derived from aliphatic glycols. In this case, examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of aliphatic glycols include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Typical polyesters include polyethylene terephthalate (PET) and polyethylene-2,6-naphthalenedicarboxylate (PEN), and it is preferable that the polyester is PET. Furthermore, as the recycled polyester resin, polyethylene terephthalate, which contains 80 mol% or more, preferably 90 mol% or more, of ethylene terephthalate units, or polyethylene-2,6-naphthalate, which contains ethylene-2,6-naphthalate units, can also be used.

[0043] On the other hand, if the recycled polyester resin is a copolymerized polyester, it is preferable that it is a copolymer containing 30 mol% or less of a third component. The third component is a component other than the compound that is the main component of the dicarboxylic acid component constituting the polyester and the compound that is the main component of the diol component. For example, in polyethylene terephthalate, it is a component other than terephthalic acid and ethylene glycol. Examples of dicarboxylic acid components of copolymerized polyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid. Examples of glycol components of copolymerized polyester include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol.

[0044] When the recycled polyester resin is a copolymer polyester, the content of isophthalic acid units relative to 100 mol% of the total dicarboxylic acid units constituting the recycled polyester resin is preferably 0.01 to 5 mol%, more preferably 0.1 to 4 mol%, even more preferably 0.5 to 3 mol%, even more preferably 0.8 to 2.5 mol%, and particularly preferably 1 to 2.2 mol%. For example, polyester such as PET bottles recycled from the market and society contains a large amount of isophthalic acid components for purposes such as controlling crystallinity. When such recycled raw materials are used, the recycled polyester resin will contain isophthalic acid units within the above range. If the isophthalic acid unit content is above the lower limit, the flexibility of the polyester layer formed from the recycled polyester resin can be increased, making it easier to obtain a polyester film with excellent shape recovery properties. On the other hand, if the isophthalic acid unit content is below the upper limit, the mechanical strength of the film can be increased. Furthermore, when polyester film is used as a support (substrate) for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors, suppressing the crystallinity of the polyester film has the advantage of reducing the generation of burrs and chips when cutting the ceramic green sheets laminated on the support using a cutting blade.

[0045] Normally, when polyester is manufactured (polycondensed) using ethylene glycol as one of the raw materials, diethylene glycol is produced as a by-product from ethylene glycol. In this specification, this diethylene glycol is referred to as by-product diethylene glycol. The amount of diethylene glycol produced as a by-product from ethylene glycol varies depending on the type of recycled raw material and the method of polycondensation. In this specification, diethylene glycol of 5 mol% or less is considered by-product diethylene glycol, and by-product diethylene glycol is considered to be included in ethylene glycol and distinguished from copolymer components. On the other hand, depending on the diethylene glycol content, more specifically, if diethylene glycol is contained in amounts exceeding 5 mol%, the diethylene glycol is treated as a copolymer component rather than as by-product diethylene glycol.

[0046] Recycled polyester resin is made by recycling (regenerating) polyester, which is a recycled raw material. The recycled raw material is preferably marine plastic. Examples of marine plastic include plastics and plastic films derived from food trays, flower pots, detergent containers, packaging for sweets, packing bands, etc., and PET bottles. The marine plastic used in this embodiment preferably contains 50% by mass or more of polyester derived from PET bottles.

[0047] Marine plastics are marine plastic waste such as plastics and plastic films derived from food trays, flower pots, detergent containers, packaging for sweets, packing bands, etc., as well as PET bottles. When recycling this marine plastic waste, various resins are separated, and recycled polyester resin is obtained by selecting polyester resin. In other words, the recycled polyester resin used in this embodiment is a polyester resin obtained by recycling and selecting marine plastics. Note that the polyester resin obtained by recycling and selecting marine plastics may contain other resins that were mixed in without being selected.

[0048] While there are no particular limitations on the method of recycling marine plastics, recycling methods such as material recycling and chemical recycling can be employed. In particular, the recycled polyester resin used in this embodiment is preferably one that has been materially recycled from marine plastics.

[0049] In the process of material recycling marine plastics, PET bottles and other materials that have accumulated on beaches and seabeds or are floating in the water are collected, sorted and identified, crushed into flakes, washed, and then pelletized. In the process of pelletizing the flakes, an extruder is used to melt, extrude, cool, and granulate. It is preferable that a filtration means is provided downstream of the extruder, and it is preferable that the filtration means has a filter that can filter out and remove solid foreign matter contained in the molten resin.

[0050] The antimony content in the recycled polyester resin is preferably 20 ppm by mass or more, more preferably 30 ppm by mass or more, and even more preferably 40 ppm by mass or more. Furthermore, the antimony content in the recycled polyester resin is preferably 2000 ppm by mass or less, more preferably 1600 ppm by mass or less, even more preferably 1200 ppm by mass or less, even more preferably 1000 ppm by mass or less, and particularly preferably 800 ppm by mass or less. The phosphorus content in the recycled polyester resin is preferably 0.5 ppm by mass or more, more preferably 1 ppm by mass or more, and even more preferably 1.5 ppm by mass or more. Furthermore, the phosphorus content in the recycled polyester resin is preferably 200 ppm by mass or less, more preferably 150 ppm by mass or less, even more preferably 100 ppm by mass or less, even more preferably 50 ppm by mass or less, even more preferably 30 ppm by mass or less, and particularly preferably 15 ppm by mass or less. The calcium content in the recycled polyester resin is preferably 0.5 ppm by mass or more, more preferably 1 ppm by mass or more, and even more preferably 1.5 ppm by mass or more. Furthermore, the calcium content in the recycled polyester resin is preferably 100 ppm by mass or less, more preferably 70 ppm by mass or less, even more preferably 50 ppm by mass or less, even more preferably 30 ppm by mass or less, and particularly preferably 20 ppm by mass or less. The magnesium content in the recycled polyester resin is preferably 0.1 ppm by mass or more, more preferably 0.2 ppm by mass or more, and even more preferably 0.3 ppm by mass or more. Furthermore, the magnesium content in the recycled polyester resin is preferably 200 ppm by mass or less, more preferably 150 ppm by mass or less, even more preferably 100 ppm by mass or less, even more preferably 50 ppm by mass or less, even more preferably 30 ppm by mass or less, and particularly preferably 25 ppm by mass or less. The titanium content in the recycled polyester resin is preferably 0.01 ppm by mass or more, more preferably 0.1 ppm by mass or more, and even more preferably 0.1 ppm by mass or more. Furthermore, the titanium content in the recycled polyester resin is preferably 2000 ppm by mass or less, more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 300 ppm by mass or less, even more preferably 100 ppm by mass or less, even more preferably 50 ppm by mass or less, and particularly preferably 20 ppm by mass or less. Furthermore, the recycled polyester resin may contain metals other than those mentioned above, but the content of these other metals is preferably 100 ppm by mass or less, more preferably 50 ppm by mass or less, even more preferably 20 ppm by mass or less, and even more preferably 10 ppm by mass or less.

[0051] Commercially available marine plastics can be used. For example, "rPET clear IV 80" manufactured by Tide Ocean SA can be used.

[0052] The recycled polyester resin may further include polyester resin obtained by recycling polyester containers (e.g., PET bottles, etc.) or polyester films (e.g., process films, etc.) that are not made from marine plastics, in addition to the polyester resin obtained by recycling marine plastics as described above. Examples of such recycled raw materials include polyester raw materials recovered on land. Furthermore, polyester recovered in the process of manufacturing polyester films or PET bottles without becoming a finished product can also be used as the recycled raw material. In this specification, polyester recovered in the process of manufacturing polyester films or PET bottles (recycled raw material) in this way is referred to as self-recovered polyester or in-system recycled polyester. For example, polyester film recovered in the process of manufacturing polyester film used as a support (substrate) for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors can be used as a recycled raw material.

[0053] There are no particular limitations on the methods for recycling polyester containers (e.g., PET bottles, etc.) and polyester films (e.g., process films, etc.) that are not marine plastics, but recycling methods such as material recycling and chemical recycling can be employed.

[0054] Self-recovering polyesters and in-system recycled polyesters may contain particles. If particles are present, the particle content is preferably 10 ppm or more by mass, more preferably 20 ppm or more, even more preferably 30 ppm or more, even more preferably 40 ppm or more, and particularly preferably 50 ppm or more. On the other hand, the particle content is preferably 500 ppm or less, more preferably 400 ppm or less, even more preferably 350 ppm or less, even more preferably 300 ppm or less, even more preferably 250 ppm or less, and particularly preferably 200 ppm or less.

[0055] Furthermore, since self-recovering polyester and in-system recycled polyester utilize film scraps and waste generated at the factory itself, the characteristics of the polyester raw material, such as the state and particle content of granular materials like gels, intrinsic viscosity, and raw material catalyst type, can be accurately determined, making it easier to achieve more stable quality in the resulting film. From this perspective, the use of self-recovering polyester and in-system recycled polyester is also preferable.

[0056] In this embodiment, the polyester used as the recycled raw material for the recycled polyester resin (marine plastic waste and other polyester resins) may be derived from biomass. In this case, it is preferable that the diol component of the polyester is derived from biomass. Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass. For example, biomass-derived ethylene glycol can be obtained by producing ethylene glycol via ethylene oxide from biomass ethanol using a conventionally known method. Alternatively, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be suitably used.

[0057] The recycled polyester resin may further contain metal components. The metal components may be used as polycondensation catalysts in the production of recycled polyester. Examples of metal components include antimony, phosphorus, manganese, calcium, magnesium, cobalt, tin, germanium, zinc, aluminum, and titanium. In particular, it is preferable that the metal component be at least one selected from the group consisting of antimony, germanium, aluminum, and titanium.

[0058] <Polyester resin> The molded article of this embodiment may contain, in addition to the recycled polyester resin described above, a non-recycled polyester resin (virgin polyester resin). Such a polyester resin may be a homopolyester or a copolymerized polyester. Specifically, a polyester obtained by polycondensation reaction of a dicarboxylic acid component and a diol component can be mentioned. In the case of a polyester film, it is preferable to use a polyester that contains more than 50 mol% of aromatic dicarboxylic acid or aliphatic dicarboxylic acid units when the dicarboxylic acid units are set to 100 mol%.

[0059] Examples of dicarboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfondicarboxylic acid, as well as aliphatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedionic acid, cyclohexanedicarboxylic acid, and their ester derivatives.

[0060] Examples of diol components include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-hexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, and spiroglycol.

[0061] When the polyester consists of a homopolyester, it is preferable to obtain one obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. In this case, examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of aliphatic glycols include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Typical polyesters include polyethylene terephthalate (PET) and polyethylene-2,6-naphthalenedicarboxylate (PEN), and it is preferable that the polyester be PET. In addition, as the polyester, polyethylene terephthalate, in which 80 mol% or more, preferably 90 mol% or more, are ethylene terephthalate units, or polyethylene-2,6-naphthalate, in which ethylene-2,6-naphthalate units, can also be used.

[0062] On the other hand, if the polyester is a copolymer, it is preferable that it is a copolymer containing 30 mol% or less of a third component. The third component is a component other than the compound that is the main component of the dicarboxylic acid component constituting the polyester and the compound that is the main component of the diol component. For example, in polyethylene terephthalate, it is a component other than terephthalic acid and ethylene glycol. Examples of dicarboxylic acid components of copolymer polyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid. Examples of glycol components of copolymer polyester include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol.

[0063] Normally, when polyester is manufactured (polycondensed) using ethylene glycol as one of the raw materials, diethylene glycol is produced as a by-product from ethylene glycol. In this specification, this diethylene glycol is referred to as by-product diethylene glycol. The amount of diethylene glycol produced as a by-product from ethylene glycol varies depending on the type of polycondensation, but it is approximately 5 mol% or less of the ethylene glycol. In this invention, diethylene glycol of 5 mol% or less is considered by-product diethylene glycol, and the by-product diethylene glycol is also included in ethylene glycol and distinguished from copolymer components. On the other hand, depending on the content of diethylene glycol, more specifically, if the content of diethylene glycol exceeds 5 mol%, the diethylene glycol is treated as a copolymer component rather than as by-product diethylene glycol.

[0064] In this embodiment, at least one of the dicarboxylic acid and diol components constituting the polyester may be derived from biomass. In particular, it is preferable that the diol component is derived from biomass. The biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass. For example, biomass-derived ethylene glycol can be obtained by conventionally known methods, such as a method of producing ethylene glycol via ethylene oxide from biomass ethanol. Alternatively, commercially available biomass ethylene glycol may be used; for example, biomass ethylene glycol commercially available from India Glycol can be suitably used.

[0065] <<Polycondensation catalyst>> Examples of polycondensation catalysts used when polycondensing the above-mentioned polyester include antimony compounds, germanium compounds, aluminum compounds, and titanium compounds. Among these, it is preferable to use at least one selected from antimony compounds and titanium compounds, and it is more preferable to use titanium compounds. By using titanium compounds as the polycondensation catalyst, it is possible to reduce the amount of polycondensation catalyst added, which makes it easier to suppress the generation of foreign matter and protrusions originating from the polycondensation catalyst.

[0066] <<Intrinsic viscosity>> The intrinsic viscosity (IV) of the polyester resin is preferably 0.5 dL / g or higher, more preferably 0.55 dL / g or higher, and even more preferably 0.6 dL / g or higher. Alternatively, the intrinsic viscosity (IV) of the polyester resin is preferably 0.85 dL / g or lower, more preferably 0.8 dL / g or lower, even more preferably 0.75 dL / g or lower, even more preferably 0.7 dL / g or lower, and particularly preferably 0.67 dL / g or lower. By setting the intrinsic viscosity (IV) of the polyester resin to be below the above upper limit, for example, when used as a polyester film, excellent surface smoothness can be achieved. Furthermore, by setting the intrinsic viscosity (IV) of the polyester resin to be above the above lower limit, it becomes easier to impart appropriate roughness to the polyester film.

[0067] Furthermore, the intrinsic viscosity (IV) of a polyester resin refers to the intrinsic viscosity (IV) of the mixed resin when two or more polyester resins with different intrinsic viscosities (IV) are used. Intrinsic viscosity can be measured according to a standard method in accordance with JIS K7367-1:2002. For example, it can be measured using an Ubbelohde viscometer with a solvent of phenol:tetrachloroethane = 1:1 at 30°C.

[0068] <> In this embodiment, in order to suppress the amount of oligomer component precipitated, molded articles may be manufactured using polyester resin with a low oligomer component content as the raw material. Various known methods can be used to manufacture polyester with a low oligomer component content, such as a method of solid-phase polymerization after polyester production. Alternatively, polyester may be obtained by esterification or transesterification, followed by melt polycondensation under reduced pressure at a higher reaction temperature. For example, it is preferable to suppress the amount of oligomer component precipitated by making the surface layer of the polyester film a layer using polyester raw material with a low oligomer component content. Solid-phase polymerization may also be performed when recycling marine plastics.

[0069] In addition to the components mentioned above, conventionally known ultraviolet absorbers, antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, etc., may be added to the molded product as needed.

[0070] <Laminated polyester film> The molded product of this embodiment is preferably a film. Such a film may be a single-layer polyester film, or it may be a laminated polyester film having two or more layers. In this case, the laminated polyester film may be a two-layer laminated polyester film consisting of a first layer and a second layer, or it may be a laminated polyester film having a surface layer, an intermediate layer and a back layer. When the polyester film is a laminated polyester film, other layers may be provided between each layer, but it is preferable that each layer is laminated so that they are in direct contact with each other.

[0071] If the polyester film is a laminated polyester film having two or more layers, the surface layer of the laminated film contains 4250 granular particles / m² with a particle size of 1000 μm or less. 2 It is preferable that the recycled polyester resin contains the above-mentioned components. The surface layer is the layer including the exposed surface of the polyester film. When the polyester film has two layers, both the first and second layers are surface layers, so it is preferable that at least one of the first and second layers contains recycled polyester resin. Furthermore, when the polyester film is a laminated polyester film having a surface layer, an intermediate layer and a back layer, the intermediate layer may contain the recycled polyester resin, and the surface layer and / or back layer may contain the recycled polyester resin. In this embodiment, it is preferable that the intermediate layer or the surface layer contains recycled polyester resin, or that the intermediate layer and the surface layer contain recycled polyester resin, or that all layers, including the surface layer, intermediate layer and back layer, contain the recycled polyester resin.

[0072] This embodiment may also relate to a roll-shaped body (winding body) made by winding a polyester film. As described above, polyester film has moderate slipperiness, as well as moderate strength and flexibility, so it can be stored and distributed as a roll-shaped body.

[0073] <Surface layer> The polyester film may be a laminated polyester film having a surface layer, an intermediate layer, and a back layer. In this case, the surface layer is preferably a layer containing polyester. When the polyester film is used as a support (substrate) for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor, the surface layer is the layer located on the side where the ceramic green sheet is laminated. In the manufacturing process of a multilayer ceramic capacitor, for example, a release layer is formed on the surface layer before the ceramic green sheet is laminated.

[0074] The surface layer consists of granular particles with a particle size of 1000 μm or less, with 4250 particles / m². 2 It is preferable to include the above-mentioned recycled polyester resin. Furthermore, as will be described later, if the intermediate layer contains the above-mentioned recycled polyester resin, the surface layer does not need to substantially contain the above-mentioned recycled polyester resin, but both the intermediate layer and the surface layer may contain the above-mentioned recycled polyester resin.

[0075] The surface layer consists of 4250 granular particles with a particle size of 1000 μm or less per square meter. 2When the recycled polyester resin containing the above-mentioned components is included, the content of the recycled polyester resin is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, based on the total mass of the resin constituting the surface layer. The content of the recycled polyester resin may be 60% by mass or more, 70% by mass or more, or 80% by mass or more. The upper limit of the content of the recycled polyester resin is not particularly limited and may be 100% by mass, based on the total mass of the resin constituting the surface layer. By including the recycled polyester resin in the surface layer, the elastic deformation power of the surface layer can be increased. This makes it easier to obtain a polyester film with excellent shape recovery properties. Furthermore, by including the recycled polyester resin in the surface layer, the arithmetic mean height (Sa) and maximum peak height (Sp) of the surface layer can be set to a desired numerical range, and it is also possible to impart appropriate roughness to the surface layer. This improves the handling properties of the laminated polyester film.

[0076] The arithmetic mean height (Sa) of the surface layer is preferably 15 nm or less, more preferably 10 nm or less, even more preferably 8 nm or less, particularly preferably 6 nm or less, and most preferably 4 nm or less. Furthermore, the arithmetic mean height (Sa) of the surface layer is preferably 0.2 nm or more, more preferably 0.4 nm or more, and even more preferably 0.6 nm or more. Thus, in this embodiment, 4250 granular materials with a particle size of 1000 μm or less are used per m². 2Even when using recycled polyester resin containing the above-mentioned properties, a polyester film with excellent surface smoothness can be obtained. On the other hand, it is preferable that the arithmetic mean height (Sa) of the surface layer be greater than or equal to the lower limit value, and that a certain amount or more of roughness is imparted. This provides the rough surface necessary to improve the handling of the laminated polyester film and reduces the air leakage index of the laminated polyester film. As a result, the laminated polyester film can exhibit appropriate slipperiness, improving handling. For example, a laminated polyester film with appropriate roughness can be easily wound into a roll.

[0077] The maximum peak height (Sp) of the surface layer is preferably 150 nm or less, more preferably 120 nm or less, even more preferably 100 nm or less, particularly preferably 80 nm or less, and most preferably 60 nm or less. Furthermore, the maximum peak height (Sp) of the surface layer is preferably 5 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. Thus, in this embodiment, 4250 granular materials with a particle size of 1000 μm or less are used per m². 2 Even when using recycled polyester resin containing the above, the generation of minute protrusions on the surface of the laminated polyester film can be effectively suppressed, and a laminated polyester film with excellent surface smoothness can be obtained. On the other hand, in this embodiment, 4250 granular particles with a particle size of 1000 μm or less are used per square meter. 2 By using recycled polyester resin containing the above-mentioned properties, it is possible to impart appropriate roughness to the surface layer and obtain a laminated polyester film with excellent handling properties.

[0078] The value obtained by dividing the maximum peak height (Sp) of the surface layer by the arithmetic mean height (Sa) of the surface layer (Sp / Sa) is preferably 130 or less, more preferably 100 or less, even more preferably 90 or less, even more preferably 80 or less, and particularly preferably 70 or less. The lower limit of the value of Sp / Sa is not particularly limited, but for example, it is preferably 5 or more, more preferably 10 or more, even more preferably 15 or more, even more preferably 20 or more, and even more preferably 25 or more.

[0079] Arithmetic mean height (Sa) is one of the surface roughness parameters (ISO 25178), and is an extension of the two-dimensional Ra (arithmetic mean roughness of a line) to three dimensions. It is calculated by dividing the volume of the area enclosed by the surface shape curve and the average plane by the measured area, and can be obtained from the following equation (1). When the surface is the XY plane and the height direction is the Z axis, if A is the defined area (the entire image) and Z(x,y) is the height of the image point (x,y) from the plane with height 0, then it can be expressed as shown in the following equation (1).

[0080]

number

[0081] Maximum peak height (Sp) is one of the surface roughness parameters (ISO 25178), representing the maximum height from the mean surface, and is expressed as shown in equation (2) below.

[0082]

number

[0083] The arithmetic mean height (Sa) and the maximum peak height (Sp) can be adjusted by controlling the type, composition, viscosity, molecular weight, thermal properties, presence or absence of copolymer components, content, etc. of the recycled polyester resin contained in the surface layer, intermediate layer, etc. Also, when adjusting the arithmetic mean height (Sa) and the maximum peak height (Sp), during the production of the polyester film, for example, control of the draw ratio (in the case of biaxial drawing, the draw ratios in the longitudinal and transverse directions), draw temperature, heat treatment temperature and treatment time (in the case of biaxial drawing, particularly the heat treatment temperature and treatment time after transverse drawing), etc. is also effective.

[0084] In this embodiment, the elastic deformation work rate (η it ) of the surface layer is preferably 49% or more, more preferably 50% or more, further preferably 52% or more, still further preferably 54% or more, particularly preferably more than 55%, and most preferably 56% or more. The upper limit value of the elastic deformation work rate (η it ) of the surface layer is not particularly limited, and the elastic deformation work rate (η it ) of the surface layer may be 60% or less, or may be 58% or less.

[0085] In this embodiment, by setting the elastic deformation work rate (η it ) of the surface layer to be not less than the above lower limit value, the shape recovery property of the surface of the laminated polyester film can be effectively enhanced. For example, when the laminated polyester film is used as a support (base material) for a ceramic green sheet in the manufacturing process of a laminated ceramic capacitor, it is possible to make it easier to peel off the ceramic green sheet laminated on the support. More specifically, when cutting the ceramic green sheet laminated on the support using a cutting blade to peel it off, the surface layer of the laminated polyester film elastically deforms appropriately, and then returns to its original shape, making it easier for the end (cutting part) of the ceramic green sheet to separate from the laminated polyester film. As a result, a good gap (lifting) can be formed between the two. And this gap (lifting) can be effectively utilized as a starting point when peeling off the ceramic green sheet. On the other hand, the elastic deformation work rate (η itBy keeping the above upper limit below the elastic deformation power of the surface layer (η it The above range can be controlled by appropriately controlling the type, composition, viscosity, molecular weight, thermal properties, presence or absence and content of copolymer components of the recycled polyester resin constituting the surface layer, as well as by appropriately setting the film formation conditions (especially the longitudinal stretching temperature, transverse stretching ratio, heat setting temperature, roll peripheral speed, relaxation rate, etc.) and film formation raw materials.

[0086] The thickness of the surface layer is preferably 1 μm or more, more preferably 1.5 μm or more, even more preferably 2 μm or more, even more preferably 2.5 μm or more, and particularly preferably 3 μm or more. Furthermore, the thickness of the surface layer is preferably 15 μm or less, more preferably 12 μm or less, even more preferably 10 μm or less, even more preferably 9 μm or less, even more preferably 8 μm or less, even more preferably 7 μm or less, and particularly preferably 6 μm or less. By setting the thickness of the surface layer above or below the above lower limit, it becomes easier to control the arithmetic mean height (Sa) and maximum peak height (Sp) of the laminated polyester film within a desired range, thereby improving the handling properties of the film while increasing surface smoothness. In particular, as will be described later, when a recycled polyester resin is included in the intermediate layer, it is preferable to set the thickness of the surface layer to below the above upper limit. Also, by setting the surface thickness above or above the above lower limit, the elastic deformation power (η) of the surface layer can be increased. it This makes it easier to control the desired range.

[0087] The surface layer may contain particles, but it is preferable that it is substantially particle-free. In typical laminated polyester films, particles are sometimes added to the surface layer to impart a certain degree of roughness to improve handling properties, but in this embodiment, 4250 granular particles with a particle size of 1000 μm or less are used per square meter. 2By using recycled polyester resin containing the above-mentioned components in the surface layer and / or intermediate layer, it is possible to impart appropriate roughness to the surface layer without adding particles to the surface layer. This makes it possible to have a surface layer that is substantially particle-free. Furthermore, because the surface layer is substantially particle-free, there is no risk of the generation of coarse protrusions due to particle aggregation or foreign matter contamination and process contamination due to particle detachment. Note that "substantially particle-free" means intentionally omitting particles, and specifically refers to a particle content (particle concentration) in the surface layer being 200 ppm or less by mass percentage, more preferably 150 ppm or less, even more preferably 100 ppm or less, and particularly preferably 50 ppm or less.

[0088] <Middle class> When the polyester film is a laminated polyester film having a surface layer, an intermediate layer, and a back layer, the intermediate layer is a layer containing polyester. Preferably, the intermediate layer functions as the thickest main layer in the laminated polyester film.

[0089] The intermediate layer consists of granular material with a particle size of 1000 μm or less, with 4250 particles / m². 2 It is preferable to include the recycled polyester resin described above. As mentioned above, if the surface layer contains the recycled polyester resin, the intermediate layer does not need to contain the recycled polyester resin substantially, but both the intermediate layer and the surface layer may contain the recycled polyester resin.

[0090] The intermediate layer consists of 4250 granular particles with a particle size of 1000 μm or less per square meter. 2When the recycled polyester resin is included, the content of the recycled polyester resin is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on the total mass of the resin constituting the intermediate layer. Furthermore, the content of the recycled polyester resin may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more. The upper limit of the content of the recycled polyester resin is not particularly limited and may be 100% by mass, based on the total mass of the resin constituting the intermediate layer. By including the recycled polyester resin in the intermediate layer within the above range, for example, CO2 emissions can be reduced, contributing to a reduction in environmental burden. Furthermore, if the recycled polyester resin is recycled from marine plastics, it can also contribute to a reduction in marine plastic waste. In addition, by including the recycled polyester resin in the intermediate layer, the arithmetic mean height (Sa) of the surface layer can be set to a certain numerical range, and it is also possible to impart appropriate roughness to the back layer. As a result, the air leakage index can be reduced, and a laminated polyester film with excellent handling properties can be obtained.

[0091] The intermediate layer functions as the thickest main layer. The thickness of the intermediate layer is preferably 8 μm or more, more preferably 10 μm or more, even more preferably 12 μm or more, even more preferably 14 μm or more, even more preferably 16 μm or more, and particularly preferably 18 μm or more. Furthermore, the thickness of the intermediate layer is preferably 34 μm or less, more preferably 32 μm or less, and even more preferably 30 μm or less.

[0092] The thickness of the intermediate layer is preferably 50-93%, more preferably 55-92%, and even more preferably 58-90% of the total thickness of the laminated polyester film.

[0093] The intermediate layer may or may not contain particles. If the intermediate layer contains particles, there are no particular restrictions on the type of particles, but examples include metal oxides such as alumina, silica, calcium carbonate, titanium dioxide, ceria, zirconium oxide, barium oxide, chromium oxide, iron oxide, and tungsten oxide; inorganic particles such as silica-zirconium oxide, silica-titanium oxide, silica-titanium oxide-barium oxide, silica-titanium oxide-zirconium oxide, borosilicate glass, aluminosilicate glass, and fluoroaluminosilicate glass; and organic particles having carboxyl groups and sulfonic acid groups.

[0094] When particles are included in the intermediate layer, the particle content is preferably 10 ppm or more by mass, more preferably 20 ppm or more, even more preferably 30 ppm or more, even more preferably 40 ppm or more, and particularly preferably 50 ppm or more. On the other hand, the particle content is preferably 500 ppm or less, more preferably 400 ppm or less, even more preferably 350 ppm or less, even more preferably 300 ppm or less, even more preferably 250 ppm or less, and particularly preferably 200 ppm or less.

[0095] <Back layer> When the polyester film is a laminated polyester film having a surface layer, an intermediate layer, and a back layer, the back layer is a layer containing polyester. When the laminated polyester film is used as a support (substrate) for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor, the back layer is a layer located on the side opposite to the side on which the ceramic green sheet is laminated.

[0096] In this embodiment, the maximum peak height (Sp) of the back surface layer is preferably 700 nm or less, more preferably 650 nm or less, even more preferably 620 nm or less, even more preferably 600 nm or less, and particularly preferably 570 nm or less. Furthermore, the maximum peak height (Sp) of the back surface layer is preferably 10 nm or more, more preferably 20 nm or more, even more preferably 30 nm or more, and even more preferably 50 nm or more. By setting the maximum peak height (Sp) of the back surface layer to be below the above upper limit, it is possible to suppress the transfer of uneven shapes caused by minute protrusions on the back surface layer to the surface layer when the laminated polyester film is laminated or wound into a roll. On the other hand, by setting the maximum peak height (Sp) of the back surface layer to be above the above lower limit, the back surface of the laminated polyester film is provided with the necessary roughness, and the handling properties of the laminated polyester film can be improved.

[0097] The arithmetic mean height (Sa) of the back layer is preferably 1 nm or more, more preferably 3 nm or more, even more preferably 5 nm or more, even more preferably 8 nm or more, and particularly preferably 12 nm or more. Furthermore, the arithmetic mean height (Sa) of the back layer is preferably 35 nm or less, more preferably 30 nm or less, and even more preferably 25 nm or less. By setting the arithmetic mean height (Sa) of the back layer to be below the above upper limit, the transfer of the uneven shape of the back layer to the surface layer can be suppressed. On the other hand, by setting the arithmetic mean height (Sa) of the back layer to be above the above lower limit, the necessary rough surface is provided to improve the handling properties of the laminated polyester film, thereby improving the handling characteristics of the laminated polyester film. For example, when winding the laminated polyester film into a roll, the laminated polyester film can exhibit appropriate slipperiness, making it easy to wind into a roll.

[0098] The value obtained by dividing the maximum peak height (Sp) of the back layer by the arithmetic mean height (Sa) of the back layer (Sp / Sa) is preferably 100 or less, more preferably 80 or less, even more preferably 50 or less, and particularly preferably 30 or less. The lower limit of the value of Sp / Sa is not particularly limited, but for example, it is preferably 5 or more, may be 10 or more, or may be 20 or more.

[0099] The back layer preferably contains particles. The presence of particles in the back layer provides smoothness and prevents scratches during each process. Furthermore, the presence of particles in the back layer makes it easier to control the maximum peak height (Sp) and arithmetic mean height (Sa) within a desired range. Alternatively, the maximum peak height (Sp) and arithmetic mean height (Sa) may be controlled within a desired range by applying surface treatment or coating to the back layer.

[0100] The type of particles in the back layer is not particularly limited as long as they can impart slipperiness. Specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, titanium oxide, and barium sulfate, as well as organic particles obtained by polymerizing acrylic acid ester monomers, styrene monomers, silicone monomers, etc., or organic particles obtained by copolymerizing these monomers, acrylic resin particles, melamine resin particles, silicone resin particles, and crosslinked polystyrene particles. Among these, it is preferable to use organic particles, calcium carbonate, silica, and aluminum oxide. Furthermore, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester manufacturing process can also be used.

[0101] In this embodiment, it is also preferable to use a combination of organic and inorganic particles in the back layer. By using a combination of organic and inorganic particles in the back layer, it becomes easier to control the arithmetic mean height (Sa) and maximum peak height (Sp) of the back layer within a desired range.

[0102] The shape of the particles in the back layer is not particularly limited; spherical, lumpy, rod-shaped, flattened, etc., may be used. Furthermore, there are no particular restrictions on their hardness, specific gravity, color, etc. Two or more types of these particles may be used in combination as needed.

[0103] Furthermore, the average particle size of the particles in the back layer is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less. Also, the average particle size is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.1 μm or more. By keeping the average particle size within the above range, the surface roughness of the back layer does not become too rough, making it easy to control the maximum peak height (Sp) and arithmetic mean height (Sa) within the desired range. Additionally, by keeping the average particle size within the above range, haze is kept low, making it easier to ensure transparency for the entire laminated polyester film.

[0104] Furthermore, if the particles are in powder form, the average particle size can be determined by using a centrifugal sedimentation particle size distribution analyzer (e.g., Shimadzu Corporation's "SA-CP3" model) to measure the equivalent spherical distribution of the powder, and using the particle size at 50% of the cumulative volume fraction (d50) as the average particle size. For particles in films, layers, or resins, the average particle size can be determined by observing 10 or more particles with a scanning electron microscope (SEM), measuring the diameter of each particle, and taking the average value. In the case of non-spherical particles, the average of the longest and shortest diameters can be used as the diameter of each particle.

[0105] The particle content in the back layer is preferably 200 ppm or more, more preferably 1000 ppm or more, and even more preferably 1500 ppm or more, relative to the total mass of the back layer. Furthermore, the particle content is preferably 20000 ppm or less, more preferably 15000 ppm or less, even more preferably 10000 ppm or less, and even more preferably 8000 ppm or less, relative to the total mass of the back layer. If two or more types of particles are blended in the back layer, it is preferable that the total particle content be within the above range. By setting the particle content above the lower limit, it is possible to effectively impart slipperiness and prevent the occurrence of scratches in each process. Furthermore, by setting the particle content below the upper limit, it is possible to effectively suppress the transfer of uneven shapes caused by minute protrusions in the back layer to the surface layer.

[0106] The method for adding particles to the back layer is not particularly limited, and conventionally known methods can be employed. For example, the particles can be added at any stage in the production of the polyester constituting the back layer, but it is preferable to add them after the esterification or transesterification reaction is completed.

[0107] The thickness of the back layer is preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1 μm or more, and particularly preferably 1.2 μm or more. Furthermore, the thickness of the back layer is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less, and particularly preferably 4 μm or less.

[0108] <Coating layer> In this embodiment, a coating layer may be provided on the surface of the molded article. When the molded article is a laminated polyester film, it is preferable to further provide a coating layer on the surface layer. In this embodiment, the coating layer is preferably a layer formed by, for example, applying a composition for forming a coating layer (coating solution) on the surface layer. As a method for forming the coating layer, there are in-line coating and off-line coating, but it is preferably formed by in-line coating. Thereby, the production efficiency of the molded article and the laminated polyester film can be enhanced.

[0109] The thickness of the coating layer is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 15 nm or more. Also, the thickness of the coating layer is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less.

[0110] When the molded article is a laminated polyester film, a coating layer is further provided on the surface layer. In this case, the total thickness of the surface layer and the coating layer is preferably 1 μm or more, more preferably 1.5 μm or more, and even more preferably 2 μm or more. Also, the total thickness of the surface layer and the coating layer is preferably 15.5 μm or less, more preferably 12.5 μm or less, even more preferably 10.5 μm or less, still more preferably 9.5 μm or less, yet more preferably 8.5 μm or less, and particularly preferably 8 μm or less. By setting the total thickness of the surface layer and the coating layer to be not less than the above lower limit value, it becomes easy to control the surface roughness of the laminated polyester film within a desired range, and the surface smoothness can be enhanced. Also, by setting the total thickness of the surface layer and the coating layer to be not less than the above lower limit value, it becomes easier to control the elastic deformation work rate (η it ) of the surface layer within a desired range.

[0111] The coating layer-forming composition preferably contains a binder resin and a crosslinking agent. The total content of the binder resin and crosslinking agent in the coating layer-forming composition is preferably 80% by mass or more as nonvolatile components, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. Furthermore, the coating layer-forming composition preferably contains particles, catalysts, etc.

[0112] <<Binder Resin>> The coating layer-forming composition preferably contains a binder resin. The binder resin is a polymer compound with a number-average molecular weight (Mn) of 1000 or more, as measured by gel permeation chromatography (GPC), in accordance with the "Flow Scheme for Evaluation of Polymer Compound Safety" (November 1985, sponsored by the Chemical Substances Council). Among these, those with film-forming properties are preferred. There are no particular restrictions on such a binder resin; for example, conventionally known binder resins such as polyester resins, polyurethane resins, (meth)acrylic resins, polyvinyl resins (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.), polyalkylene glycols, polyalkyleneimines, methylcellulose, hydroxycellulose, and starches can be used. Among these, from the viewpoint of film-forming properties and adhesion to polyester films, it is preferable to include one or more selected from the group consisting of polyester resins, polyurethane resins, and (meth)acrylic resins, and more preferably to include one or more selected from the group consisting of polyester resins and polyurethane resins. In this resin composition, one type of binder resin may be used alone, or two or more types may be used in combination.

[0113] Examples of polyester resins, polyurethane resins, (meth)acrylic resins, and polyvinyl resins used as binder resins include, for example, the compounds described in International Publication No. 2023 / 145952.

[0114] The binder resin content in the coating layer-forming composition is preferably 5 to 95% by mass, more preferably 10 to 80% by mass, even more preferably 20 to 70% by mass, and even more preferably 30 to 60% by mass, as a percentage of the total non-volatile components in the coating layer-forming composition. By setting the content within the above range, it is possible to easily form a film that has film-forming properties and contains particles. In addition, by improving adhesion with the polyester film, it is possible to suppress the peeling of the coating film.

[0115] <<Crosslinking agent>> The coating layer-forming composition preferably contains a crosslinking agent. There are no particular restrictions on the crosslinking agent, and conventionally known crosslinking agents can be used. Examples of crosslinking agents include melamine compounds, isocyanate compounds, oxazoline compounds, epoxy compounds, carbodiimide compounds, and silane coupling compounds. Among these, it is preferable to include a melamine compound from the viewpoint of increasing the strength of the coating layer and improving adhesion with the polyester film. In the coating layer-forming composition, the crosslinking agent may be used alone or two or more may be used in combination.

[0116] Examples of melamine and isocyanate compounds used as crosslinking agents include those described in International Publication No. 2023 / 145952.

[0117] The crosslinking agent content in the coating layer-forming composition is preferably 5 to 50% by mass, more preferably 8 to 40% by mass, even more preferably 10 to 35% by mass, and particularly preferably 15 to 30% by mass, as a percentage of the total nonvolatile components in the coating layer-forming composition. By setting the content within the above range, it is possible to easily form a film that has film-forming properties and contains particles. In addition, by improving adhesion with the polyester film, it is possible to suppress the peeling of the coating film.

[0118] <<Particle>> The coating layer-forming composition preferably contains particles. Examples of particles include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, zirconium oxide, aluminum oxide, and titanium oxide, as well as crosslinked polymers such as crosslinked silicone resin particles, crosslinked acrylic resin particles, crosslinked styrene-acrylic resin particles, and crosslinked polyester particles, and organic particles such as calcium oxalate and ion exchange resins. Among these, zirconium oxide, titanium oxide, and silica are preferred, with zirconium oxide and silica being more preferred. The particles may be used individually or in combination of two or more types.

[0119] The particles used can be spherical, lumpy, rod-shaped, flattened, or chain-shaped. Among these, spherical particles are preferred because they are easily distributed uniformly within the resin composition.

[0120] The average particle size is preferably 0.5 to 300 nm, more preferably 1 to 250 nm, even more preferably 2 to 200 nm, even more preferably 2.5 to 200 nm, even more preferably 3 to 150 nm, even more preferably 3.5 to 100 nm, even more preferably 4 to 60 nm, and particularly preferably 4.5 to 30 nm. Within this range of average particle size, the generation of coarse protrusions due to particle aggregation and process contamination due to particle shedding can be suppressed. The average particle size can be measured by calculating it from the specific surface area measured by a specific surface area analyzer and the density of the particles, by observing with a transmission electron microscope (TEM) or scanning electron microscope (SEM) and calculating the diameter of the particles, or by measuring it using dynamic light scattering. The method most suitable for the average particle size can be used.

[0121] The content of particles in the coating layer forming composition is preferably in the range of 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, and even more preferably 0.1 to 10% by mass, as a percentage of the total nonvolatile components in the coating layer forming composition. By keeping the content within the above range, the elastic deformation power (η) of the surface of the molded product is improved.it This makes it easier to control the desired range.

[0122] <Method for manufacturing laminated polyester film> The method for manufacturing the laminated polyester film of this embodiment includes the step of laminating a polyester layer A constituting the surface layer, a polyester layer B constituting the intermediate layer, and a polyester layer C constituting the back layer. Alternatively, the method for manufacturing the laminated polyester film of this embodiment includes the step of supplying polyester resin A constituting the surface layer, polyester resin B constituting the intermediate layer, and polyester resin C constituting the back layer to their respective extruders, melting them, and then co-extruding them. In each extruder, each polymer is heated above its melting point to form a molten polymer. The molten polymer is then extruded from the die and cooled and solidified on a rotating cooling drum to a temperature below the glass transition point of the polymer, thereby obtaining an unstretched laminated polyester film. In this embodiment, at least one layer of the laminated polyester film contains 4250 granular particles / m² with a particle size of 1000 μm or less. 2 The material contains recycled polyester resin. For example, the intermediate layer may contain the recycled polyester resin, and the surface layer and / or back layer may contain the recycled polyester resin. Alternatively, all layers may contain the recycled polyester resin.

[0123] In this embodiment, a step of stretching the unstretched laminated polyester film may be provided. In the stretching step, the unstretched laminated polyester film is first stretched in one direction using a roll or tenter type stretcher. At this time, the stretching temperature is usually 25 to 120°C, preferably 35 to 100°C, and the stretching ratio is usually 2.5 to 7 times, preferably 2.8 to 6 times. Next, it is preferable to stretch in a direction perpendicular to the first stretching direction. At this time, the stretching temperature is usually 50 to 140°C, and the stretching ratio is usually 3.0 to 7 times, preferably 4.0 times or more, more preferably 4.5 to 5.0 times. In addition, in the stretching step, a method of performing unidirectional stretching in two or more stages can also be adopted.

[0124] Then, it is preferable to continue the heat-setting treatment at a temperature of 180-220°C under tension or under relaxation of 30% or less. In this way, a biaxially oriented laminated polyester film is obtained. The heat-setting treatment may be carried out in two or more steps at different temperatures. Alternatively, cooling may be performed in a cooling zone after the heat-setting treatment. The cooling temperature is preferably higher than the glass transition temperature (Tg) of the polyester resin constituting the laminated polyester film, and more specifically, it is preferably in the range of 100-160°C. This cooling may be carried out in two or more steps at different temperatures.

[0125] In this embodiment, a step of forming a coating layer on the surface layer may be provided. In the step of forming the coating layer, the coating layer is formed by applying a coating layer forming composition (coating liquid) onto the surface layer.

[0126] When forming a coating layer by applying a coating layer-forming composition (coating liquid) onto a surface layer, the coating layer-forming composition (coating liquid) is applied to the surface layer, and if necessary, the applied resin composition is subjected to drying, curing, heat treatment, etc. In this embodiment, at least heat treatment is preferred.

[0127] The composition for forming the coating layer is not particularly limited. The method for applying the composition for forming the coating layer is not particularly limited, and conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating can be used.

[0128] Furthermore, in-line coating or offline coating methods can be used as methods for forming the coating layer. The method for heat-treating the applied coating layer-forming composition is not particularly limited. For example, when forming the coating layer by offline coating, it is generally preferable to heat-treat at 80-200°C for 3-40 seconds, preferably at 100-180°C for 3-40 seconds. On the other hand, when forming the coating layer by in-line coating, it is generally preferable to heat-treat at 70-280°C for 3-200 seconds. The heat treatment may be carried out in two or more stages with different temperatures within the above temperature range. At least a portion of the heat treatment may be carried out by heating during stretching. Furthermore, drying and curing may be carried out together with the heating in the above heat treatment.

[0129] The coating layer is preferably formed by in-line coating, which treats the film surface during the polyester film manufacturing process. In-line coating is a method of coating within the polyester film manufacturing process, specifically, a method of coating at any stage from melt extrusion of polyester to stretching, heat fixing, and winding. Typically, the coating is applied to an unstretched sheet obtained by melting and quenching, a stretched uniaxially oriented film, a biaxially oriented film before heat fixing, or a film after heat fixing but before winding.

[0130] For example, when sequential biaxial stretching is performed, a superior method is to coat a uniaxially stretched film (stretched longitudinally) with a coating layer-forming composition and then stretch it transversely. This method offers cost advantages in manufacturing because film formation and coating layer formation can be performed simultaneously. Furthermore, because stretching is performed after coating, the thickness of the coating layer can be varied according to the stretching ratio, making thin-film coating easier compared to offline coated films.

[0131] <Application> The molded articles of this embodiment can be suitably used for various applications. Examples of molded articles include plastic trays, plastic containers, plastic tableware, housings for various electronic devices, furniture, exterior and interior materials, automobile parts, toys, eyeglass frames, films, sheets, bottles, tubes, fibers, clothing, etc. The molding method for the molded articles is not particularly limited, but for example, molding methods such as injection molding, extrusion molding, blow molding, and vacuum forming can be used. Among these, it is preferable that the molded articles be molded by injection molding or extrusion molding. That is, it is preferable that the molded articles be injection molded or extruded. When molding molded articles by injection molding, etc., a mold may be used in the molding process, but since the molded articles of this embodiment have a high elastic deformation power, the occurrence of molded defects can be suppressed. Furthermore, since the molded articles of this embodiment have a moderate roughness on the surface, they also have excellent mold release properties.

[0132] Furthermore, if the molded product is a polyester film, the polyester film can be used for a variety of applications. For example, it can be used in industrial materials, optical materials, electronic component materials, battery packaging materials, food packaging materials, and the like. The polyester film of this embodiment is also suitable for release applications. For example, it can be used for various release and process applications such as dry film resist (DFR), multilayer circuit boards, and ceramic green sheet manufacturing for multilayer ceramic capacitors. In release and process applications, the polyester film can be used, for example, as a support, and various materials such as ceramic slurry may be applied or laminated on the support.

[0133] In particular, the polyester film of this embodiment has excellent surface smoothness and can be used to thin ceramic green sheets, making it preferable to use it as a support for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors. That is, the laminated polyester film of this embodiment is preferably a laminated polyester film for manufacturing multilayer ceramic capacitors. The laminated polyester film of this embodiment has excellent surface smoothness even though it contains recycled polyester resin, so even when manufacturing thin ceramic green sheets, it can suppress defects such as the occurrence of pinholes in the ceramic green sheets. If surface defects such as pinholes occur in the ceramic green sheet, it can significantly affect quality reliability in terms of short-circuit failures and variations in capacitance, which is problematic.

[0134] Furthermore, in the future, as multilayer ceramic capacitors for automobiles become increasingly electrified, it is predicted that the thickness of the ceramic green sheet used will decrease, particularly as capacitors become smaller and their capacitance increases. Therefore, polyester film is preferably used as a support for the ceramic green sheet in the manufacturing process of automotive ceramic capacitors.

[0135] (Release film) The molded product of this embodiment may further have a release layer on at least one side. For example, if the molded product of this embodiment is a laminated polyester film, it is preferable that the release layer be formed on the surface layer side of the laminated polyester film, and in such a release film, it is preferable that the configuration be release layer / surface layer / intermediate layer / backside layer. If the laminated polyester film has a coating layer, the configuration may be release layer / coating layer / surface layer / intermediate layer / backside layer. The release layer is laminated to the laminated polyester film directly or via other layers. Other layers include, for example, an easy-adhesion coating layer to improve adhesion to the polyester film, as well as an antistatic layer and an anti-blocking layer. By providing a release layer on the surface layer in this way, when the polyester film is used as a support (substrate) for the ceramic green sheet in the manufacturing process of a laminated ceramic capacitor, it is possible to easily peel off the ceramic green sheet laminated on the release layer.

[0136] In this case, the release layer is formed from a release agent composition containing a release agent, and it is preferable that the release agent composition contains a silicone-based release agent or a non-silicone-based release agent.

[0137] Examples of silicone-based mold release agents include mold release agents mainly composed of curable silicone resin, modified silicone mold release agents produced by graft polymerization with organic resins such as urethane resin, epoxy resin, and alkyd resin, or fluorosilicone mold release agents. Among these, silicone-based mold release agents are more preferably those containing curable silicone resin.

[0138] As the curable silicone resin, any existing curing reaction type can be used, such as addition-type, condensation-type, or other thermosetting types, or electron beam-curing types such as UV-curing types. Multiple types of curable silicone resins may also be used in combination.

[0139] Examples of non-silicone-based release agents include waxes, long-chain alkyl group-containing compounds, and fluorine compounds.

[0140] Examples of waxes include natural waxes, synthetic waxes, and modified waxes. Examples of natural waxes include plant-based waxes, animal-based waxes, mineral waxes, and petroleum waxes. Examples of plant-based waxes include candelilla wax, carnauba wax, rice wax, wood wax, and jojoba oil. Examples of animal-derived waxes include beeswax, lanolin, and whale wax. Examples of mineral-based waxes include montan wax, ozokerite, and ceresin. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and petrolatum. Examples of synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, ester waxes, and ketones.

[0141] Long-chain alkyl group-containing compounds are compounds having a linear or branched alkyl group with 6 or more carbon atoms, preferably 8 or more, and more preferably 12 or more. Examples of alkyl groups include hexyl, octyl, decyl, lauryl, octadecyl, and behenyl groups. Examples of alkyl group-containing compounds include various long-chain alkyl group-containing polymer compounds, long-chain alkyl group-containing amine compounds, long-chain alkyl group-containing ether compounds, and long-chain alkyl group-containing quaternary ammonium salts. Polymer compounds having long-chain alkyl groups as side chains can be obtained by reacting a polymer having a reactive group with a compound having an alkyl group that can react with the reactive group. Examples of the reactive group include hydroxyl, amino, carboxyl, and acid anhydride. Examples of compounds having these reactive groups include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resin, and reactive group-containing poly(meth)acrylic resin. Among these, polyvinyl alcohol is preferred considering ease of handling.

[0142] Fluorine compounds are compounds that contain fluorine atoms. Organic fluorine compounds are preferably used as fluorine compounds, and examples include perfluoroalkyl group compounds, polymers of olefin compounds containing fluorine atoms, and aromatic fluorine compounds such as fluorobenzene.

[0143] There are no particular restrictions on the coating form of the release agent composition when forming the release layer. Preferably, the release agent composition contains a solvent in addition to the release agent. The release agent composition may be in the form of being dissolved in an organic solvent, in the form of an aqueous emulsion, or in a solvent-free form.

[0144] The mold release agent composition that forms the release layer may also contain, as needed, a binder, an antifoaming agent, a coating properties improver, a thickener, inorganic particles, organic particles, an organic lubricant, an antistatic agent, a conductive agent, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, and the like.

[0145] The release layer is provided by coating the polyester film with a release agent composition, and either in-line coating performed within the film manufacturing process or so-called off-line coating applied outside the system to a film that has already been manufactured may be employed.

[0146] Conventional coating methods for providing a release layer on a polyester film include reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating.

[0147] The curing conditions for forming the release layer are not particularly limited. When providing a release layer by offline coating, it is generally preferable to perform heat treatment at 80°C or higher for 10 seconds or more, preferably at 100-200°C for 3-40 seconds, and more preferably at 120-180°C for 3-40 seconds.

[0148] The amount of release layer applied (after drying) is typically 0.005 to 5 g / m², considering the coating properties. 2Preferably 0.005 to 1 g / m 2 , more preferably 0.005~0.1 g / m 2 It is within this range. The coating amount (after drying) is 0.005 g / m². 2 With the above conditions, good stability in terms of coating properties can be obtained, and a uniform coating film can be obtained. On the other hand, 5 g / m 2 The following conditions result in good coating adhesion, curing properties, etc., of the release layer itself.

[0149] (Film with ceramic green sheet) This embodiment may relate to a film with a ceramic green sheet, in which a ceramic green sheet is laminated onto the molded product (laminated polyester film) described above, or it may relate to a release film with a ceramic green sheet used in the manufacturing process of automotive ceramic capacitors. The release film with a ceramic green sheet is obtained in the manufacturing process of a laminated ceramic capacitor. The laminated polyester film of this embodiment is suitable for manufacturing thin films of ceramic green sheets, so for example, the thickness of the ceramic green sheet after drying may be 2 μm or less, 1 μm or less, or 0.5 μm or less.

[0150] This embodiment may relate to the use of the above-described molded product (laminated polyester film) as a support for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor. Furthermore, this embodiment may relate to a method for manufacturing a ceramic green sheet, comprising the step of coating at least one side of the above-described molded product (laminated polyester film) with a ceramic slurry containing ceramic components.

[0151] In manufacturing the ceramic green sheet-attached film of this embodiment, a ceramic slurry containing ceramic components and binder resin can be applied to the surface layer or coating layer of the laminated polyester film described above, or to the release layer of the release film described above, and then dried to produce a ceramic green sheet (dielectric sheet). [Examples]

[0152] The features of the present invention will be further described below with reference to examples and comparative examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following specific examples.

[0153] [Polyester raw material] The polyester raw materials used in the examples and comparative examples are as follows: (1) Polyester A: Homopolyethylene terephthalate (titanium-based catalyst, intrinsic viscosity 0.63 dL / g) (2) Polyester B: Homopolyethylene terephthalate (titanium-based catalyst, intrinsic viscosity 0.70 dL / g) (3) Polyester C: Homopolyethylene terephthalate (antimony catalyst, intrinsic viscosity 0.85 dL / g) (4) Polyester D: Material recycled polyethylene terephthalate derived from marine plastics, "rPET clear IV 80" manufactured by Tide Ocean SA (intrinsic viscosity 0.893 dl / g, isophthalic acid unit content 1.7 mol% per 100 mol% of total dicarboxylic acid units, diethylene glycol unit content 2.2 mol% per 100 mol% of total glycol units) (5) Polyester E: Material recycled polyethylene terephthalate derived from PET bottles, "UK-31" manufactured by Utsumi Recycling Systems Co., Ltd. (intrinsic viscosity 0.711 dl / g, isophthalic acid unit content 1.4 mol% per 100 mol% of total dicarboxylic acid units, diethylene glycol unit content 2.29 mol% per 100 mol% of total glycol units) (6) Polyester F: Masterbatch containing 2.0% by mass of 0.7 μm calcium carbonate particles in homopolyethylene terephthalate (antimony catalyst) (intrinsic viscosity 0.61 dL / g) (7) Polyester G: A masterbatch (intrinsic viscosity 0.61 dL / g) containing 0.4% by mass of 0.8 μm organic particles in homopolyethylene terephthalate (antimony catalyst).

[0154] (Comparative Example 1) Polyester B was used as the raw material for the surface layer, polyester A as the raw material for the intermediate layer, and a blend of polyester C (28%), polyester F (22%), and polyester G (50%) by mass was used as the raw material for the back layer. This blend was supplied to a vented extruder and melt-extruded at 280°C. The raw materials for the surface and back layers were then used as the outermost layers, resulting in a three-layer structure of three types (surface layer A / intermediate layer / back layer C), which was co-extruded. The co-extrusion was performed under extrusion conditions such that the thickness composition ratio A / B / C = 4.0 / 25.0 / 2.0. An amorphous film was obtained by cooling and solidifying on a cooling roll with a surface temperature set to 20°C using an electrostatic application adhesion method. Next, the film was stretched 3.5 times in the longitudinal direction, i.e., in the MD direction, at a film temperature of 86°C using the difference in roll peripheral speed. This longitudinally stretched film was guided into a tenter, preheated to 90°C inside the tenter, then stretched 4.2 times in the transverse direction, i.e., the TD direction, at 105°C. Heat treatment was then performed at 230°C in the heat treatment (fixing) zone inside the tenter, followed by a cooling treatment at 140°C with a relaxation rate of 2%, resulting in a polyester film with a total thickness of 31 μm.

[0155] (Comparative Example 2) In Comparative Example 1, a polyester film with a total thickness of 31 μm was obtained by manufacturing in the same manner as in Comparative Example 1, except that a raw material blend of polyester A and polyester E in a mass ratio of 50% and polyester E was used as the raw material for the intermediate layer, and the stretch ratio in the TD direction was set to 4.5 times.

[0156] (Example 1) In Comparative Example 1, the same procedure was used as for the intermediate layer, except that a raw material blend of 80% polyester A and 20% polyester D was used, to obtain a polyester film with an overall thickness of 31 μm.

[0157] (Comparative Example 3) Polyester E was used as the raw material for the surface layer, and polyester A as the raw material for the intermediate layer. A blend of polyester A (80%) and polyester F (20%) was used as the raw material for the back layer. This blend was supplied to a vented extruder and melt-extruded at 280°C. The raw materials for the surface and back layers were then used as the outermost layers, resulting in a three-layer structure of three types (surface layer A / intermediate layer / back layer C). The extrusion conditions were adjusted so that the thickness composition ratio of A / B / C was A / 27.8 / 1.6. An amorphous film was obtained by cooling and solidifying on a cooling roll with a surface temperature set to 20°C using an electrostatic application adhesion method. Next, the film was stretched 3.5 times in the longitudinal direction, i.e., in the MD direction, at a film temperature of 86°C using the difference in roll peripheral speed. This longitudinally stretched film was guided into a tenter, preheated to 90°C inside the tenter, then stretched 4.2 times in the transverse direction, i.e., the TD direction, at 105°C. Heat treatment was then performed at 230°C in the heat treatment (fixing) zone inside the tenter, followed by a cooling treatment at 140°C with a relaxation rate of 2%, resulting in a polyester film with a total thickness of 31 μm.

[0158] (Example 2) In Comparative Example 3, the same procedure was followed as in Comparative Example 3, except that polyester D was used as the raw material for the surface layer, to obtain a polyester film with a total thickness of 31 μm.

[0159] <Measurement and Evaluation Methods> (1) Arithmetic mean height (Sa), maximum peak height (Sp) Using a surface roughness measuring instrument (AMETEK, "NewView" registered trademark), the surface of the front layer and the back layer of a polyester film (5cm x 5cm) were measured, and the arithmetic mean height (Sa) and maximum peak height (Sp) were determined from the resulting surface profile curves. Specifically, measurements were performed using the surface roughness measuring instrument described above, under the conditions of objective lens magnification of 10x, zoom magnification of 2.0x, and field of view of 0.44mm × 0.44mm. After performing the following processing, the arithmetic mean height (Sa) and maximum peak height (Sp) were calculated. Measurements were taken at 12 points, and the average of the 10 points excluding the maximum and minimum values ​​was used as the measured value. FilterType:Spline Filter: High Pass Type:Robust Gaussian Spline Fixed Cutoffs Mode:Period Long Period: 200 μm

[0160] (2) Air leakage index Using a Digibec smoothness tester (Toyo Seiki Co., Ltd., "DB-2"), the air leakage index was measured in accordance with JIS P8119 under conditions of 23°C and 50% relative humidity. The pressurizing device pressure was set to 100kPa, and a 38ml vacuum container was used. The time it took for 1mL of air to flow, i.e., the time (in seconds) for the pressure inside the container to change from 50.7kPa to 48.0kPa, was measured, and 10 times the obtained number of seconds was used as the air leakage index. The polyester film sample size was 70mm square, and 20 sheets were laminated so that the front and back sides of the film overlapped to create a test laminated film. A 5mm diameter hole was made in the center of this test laminated film, and the air leakage index was measured as described above. A higher value for the air leakage index indicates that it takes longer for air to leak through the gaps between the films, indicating that the films are more tightly packed together and that wrinkles are more likely to occur when the film is rolled up. Furthermore, the reduction rate of the air leakage index was calculated using the following formula. Air leakage index reduction rate (%) = 100 - Air leakage index of target polyester film / Air leakage index of virgin polyester film × 100 The air leakage index of the virgin polyester film in the above formula is the air leakage index of the polyester film obtained in Comparative Example 1.

[0161] (3) Tc (temperature at which recrystallization occurs), Tm (peak melting temperature), ΔHm (peak melting heat) An 8 mg sample, cut from the evaluation film, was measured using a differential scanning calorimeter (DSC8500) manufactured by Shimadzu Corporation. The sample temperature is, (1) Increase the temperature from 20°C to 300°C at a rate of 10°C / min. (2) Hold at 300°C for 5 minutes (3) Cool down to 20°C at 600°C / min (4) Hold at 20°C for 5 minutes (5) Increase the temperature from 20°C to 300°C at a rate of 10°C / min. (6) Hold at 300°C for 5 minutes (7) Cool down to 20°C at 600°C / min The scan was performed in the following order to determine the melting peak temperature (Tm: peak top temperature of the endothermic curve of crystal melting) and melting peak heat quantity (ΔHm: peak heat quantity of the endothermic curve of crystal melting) at (1), and the heating recrystallization temperature (Tc: peak top temperature of the exothermic curve of heating recrystallization) at (5).

[0162] (4) Gas density Gas density was measured using a Shimadzu Accuphase 1330 (dry automatic densimeter). The following measurement conditions were followed, and each film sample was vacuum-dried for at least 30 minutes before measurement. ·Measurement temperature: 23℃ • Measurement cell used: 10cm 3 • Gas used: Helium gas (purity > 99.99995% by volume)

[0163] (5) Elastic deformation power Approximately 2-8 mg of Aron Alpha® (general-purpose, manufactured by Toa Gosei Kagaku Co., Ltd.) was dropped onto a microscope slide (S1112, manufactured by Matsunami Glass Industry Co., Ltd.). A polyester film (1.5 cm x 1.5 cm) was then placed on top, with the back surface facing outwards, and cured. After fixing the microscope slide with the polyester film attached to the sample stage of a hardness tester (Dynamic Microhardness Tester (DUH-211S, manufactured by Shimadzu Corporation)), a load-unload test was performed on the surface (surface layer) of the polyester film, and the elastic deformation power (η) was calculated using the following formula. it The following formula was used to calculate (the average of 5 measurements, excluding the first measurement out of 6 n=6): Wtotal = Wplast + Welast (N·m) (Wtotal = total deformation work (N·m), Wplast = plastic deformation work (N·m), Welast = elastic deformation work (N·m)) η it= (Welast / Wtotal) × 100 (%) (Measurement conditions) Indenter used: Diamond triangular pyramidal indenter (angle between edges: 115) Measurement mode: Load-unload test Test force: 20.00 mN Minimum test force: 0.20 mN Loading speed: 0.1464 mN / sec Load holding time: 0 sec Unloading holding time: 0 sec Measurement atmosphere: 23 ± 2℃, relative humidity 50 ± 5% Number of measurements: 6

[0164] (6) Content of isophthalic acid and diethylene glycol components contained in polyester A sample solution was prepared by dissolving the raw material polyester in a solvent prepared by mixing chloroform D (manufactured by EURISO-TOP) and trifluoroacetic acid D1 (manufactured by EURISO-TOP) in a 10:1 volume ratio. The proton NMR of the sample solution was measured using an NMR spectrometer ("GEMINI-200"; manufactured by Varian) at a temperature of 23°C and with 64 cumulative measurements. In the NMR measurement, the peak intensity of a predetermined proton was calculated to determine the content of isophthalic acid units in 100 mol% dicarboxylic acid units and the content of diethylene glycol units in 100 mol% glycol units (mol%).

[0165] (7) Number of granular particles and average particle size By continuously extruding polyesters A to E into sheets with a width of 10 cm and a thickness of 50 μm, and shining light from above onto a region of approximately 6 cm in the center of the width direction, and capturing shadows originating from granular material (gel) from the underside of the sheet with a CCD camera, 1 m 2 The number of granular particles present was measured. The gel counter consisted of a camera system, an extruder, and a cooling roll unit. The gel counter used was the "FS-5 Film Scan (camera system), ME-20 / 26 V2 Measuring Extruder (extruder), CR-7 Chill Roll Unit (cooling roll unit)" manufactured by Optical Control Systems. The measurement conditions were as follows. The number of granular particles and the average particle size are shown in Table 3. • Cooling roll temperature: 30°C • Extruder cylinder temperature: 295℃ Extruder screw rotation speed: 100 rpm • Sheet thickness: 50μm

[0166] [Table 1]

[0167] [Table 2]

[0168] [Table 3]

[0169] In Example 1, a recycled polyester resin containing a specific amount of granular material with a particle size of 1000 μm or less was used as the intermediate layer, resulting in a lower air leakage index compared to the films of Comparative Examples 1 and 2, and improved handling properties of the polyester film. Furthermore, in Example 2, a recycled polyester resin containing a specific amount of granular material with a particle size of 1000 μm or less was used as the surface layer, resulting in a higher elastic deformation power compared to Comparative Example 3. This means that even if the molded product is deformed, its shape is more easily restored to its original state. Therefore, it is considered that the shape of the molded product is more easily maintained during molding, leading to increased production efficiency. [Industrial applicability]

[0170] The molded articles of the present invention can be manufactured using marine plastic waste to produce polyester resin molded articles, and can also provide molded articles with excellent handling properties and shape recovery. The molded articles of the present invention can also contribute to the reduction of marine plastic waste, and are expected to have diverse applications, such as as supports (substrates) for ceramic green sheets in the manufacturing process of multilayer ceramic capacitors.

Claims

1. A molded article containing recycled polyester resin, The recycled polyester resin contains 4,250 granular particles with a particle size of 1,000 μm or less per square meter. ２ Molded product including the above.

2. The molded article according to claim 1, wherein the recycled polyester resin is made from recycled marine plastic.

3. A molded article according to claim 1 or 2, which is a film.

4. The molded article according to claim 3, wherein the arithmetic mean height (Sa) of at least one surface is 15 nm or less.

5. The molded article according to claim 3, wherein the maximum peak height (Sp) of at least one surface is 150 nm or less.

6. The molded article according to claim 3, wherein the film is a laminated film having two or more layers, and the surface layer of the laminated film contains the recycled polyester resin.

7. The molded article according to claim 3, wherein the film is a laminated film having a surface layer, an intermediate layer and a back layer, and the intermediate layer contains the recycled polyester resin.

8. The molded article according to claim 3, wherein the film is a laminated film having a surface layer, an intermediate layer, and a back layer, and the surface layer and / or back layer contains the recycled polyester resin.

9. The molded article according to claim 7, wherein the thickness of the surface layer is 1 to 8 μm.

10. The molded article according to claim 7, wherein the surface layer substantially does not contain particles.

11. The molded article according to claim 7, wherein the thickness of the intermediate layer is 50 to 93% of the total film thickness.

12. The molded article according to claim 3, wherein the air leakage index is 6500 seconds or less.

13. The molded article according to claim 3, wherein the reduction rate of the air leakage index calculated by the following formula is 18% or more. Air leakage index reduction rate (%) = 100 - Air leakage index of the target polyester film / Air leakage index of the virgin polyester film × 100

14. The molded article according to claim 3, wherein the elastic deformation power is 49% or more.

15. The molded article according to claim 1 or 2, wherein the content of isophthalic acid units relative to 100 mol% of the total dicarboxylic acid units constituting the polyester resin in the recycled polyester resin is 0.01 to 5 mol%.

16. The molded article according to claim 3, wherein the temperature of recrystallization (Tc) is 145°C or lower.

17. The molded article according to claim 3, wherein the melting peak temperature (Tm) is 254.1°C or less.

18. A molded article according to claim 1 or 2, further comprising recycled polyester resin obtained by recycling polyester film.

19. The molded article according to claim 7, further comprising a coating layer on the surface layer.

20. The molded article according to claim 19, wherein the total thickness of the surface layer and the coating layer is 1 to 8 μm.

21. The molded article according to claim 1 or 2, wherein the intrinsic viscosity of the recycled polyester resin is 0.70 dL / g or more.

22. The molded article according to claim 3, which is used as a support for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor.

23. A release film further having a release layer on at least one side of the molded article according to claim 3.

24. A film with a ceramic green sheet, wherein a ceramic green sheet is laminated onto the molded product described in claim 3.

25. The use of the molded product according to claim 3 as a support for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor.

26. A method for producing a ceramic green sheet, comprising the step of coating at least one side of a molded article according to claim 3 with a ceramic slurry containing a ceramic component.

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