Polyester film and laminated polyester film

Abstract

The present invention relates to a polyester film, wherein one surface (A) of the polyester film satisfies the following (11) to (13): (11) The number of protrusions (Y) above 100 nm is 1 or less per mm². (12) The number of protrusions (X) below 50 nm is 2000 or more per mm². (13) The maximum peak height (Sp) is 60 nm or less.

Description

Polyester film and laminated polyester film This invention relates to a polyester film and a multilayer polyester film suitable as a support for a release film used in the manufacturing process of multilayer ceramic capacitors. In recent years, with the electrification of automobiles and the increasing functionality of smartphones, the miniaturization and high capacitance of multilayer ceramic capacitors (MLCCs) are constantly developing. MLCCs are manufactured as follows: First, a ceramic slurry containing ceramic components and binder resin is coated onto a release film and dried to create a ceramic preform (dielectric sheet). Electrodes are then printed onto the ceramic preform using methods such as screen printing to create internal electrodes. After drying, the printed ceramic preform is peeled off from the release film, and multiple preforms are stacked. The stacked preforms are then pressed to integrate them and cut into individual wafers. Finally, the internal electrodes and dielectric layers are sintered in a furnace to manufacture the multilayer ceramic capacitor. As MLCCs become smaller and have higher capacitance, the thin-film technology of ceramic preforms is continuously developing. When the thin-film technology of ceramic preforms is further advanced to below 0.5 μm (after drying thickness), if the surface of the release film used as the carrier film has tiny protrusions, pinholes and other defects will occur in the ceramic preform. Therefore, a higher degree of surface smoothness is required for this release film. Previously, as a support for such a release film, Patent Document 1 disclosed a release film for manufacturing ceramic blanks, characterized by comprising: a substrate having a first surface and a second surface; a smoothing layer disposed on the first surface side of the substrate; and a release agent layer disposed on the surface of the smoothing layer opposite to the substrate; wherein the smoothing layer is formed by heating and hardening a smoothing layer forming composition containing a thermosetting compound having a weight average molecular weight of 950 or less, and the arithmetic mean roughness Ra of the outer surface of the release agent layer is... 1 is less than 8 nm, and the maximum protrusion height Rp on the outer surface of the aforementioned stripping agent layer. 1 is below 50 nm. Furthermore, in Patent Document 2, a release polyester film with excellent surface smoothness, especially fewer micro-defects on the film surface, was proposed, which has a number of dents with a depth of 0.5 μm or more of 5 per m. 2 The following are release polyester films with a centerline average roughness SRa of at least one surface being 15 to 35 nm and a ten-point average roughness SRz of 1000 nm or less. Furthermore, Patent Document 3 discloses a polyester film, which is a polyester film roll formed by winding a polyester film, and the loosening defects present in the aforementioned polyester film are less than 100 m. 2 Fewer than 5. [Prior Art Documents] [Patent Documents] Patent Document 1: Japanese Patent Application Publication No. 2014-177093; Patent Document 2: Japanese Patent Application Publication No. 2013-7054; Patent Document 3: Japanese Patent Application Publication No. 2018-90803 [The problem the invention aims to solve] Previously, the surface condition of the membrane was controlled by adjusting the type, average particle size, and dosage of particles used to create fine irregularities. However, with the decreasing thickness of ceramic preforms, more precise control of irregularities is required, and the previous method of controlling the membrane surface using particles has limitations. Therefore, the industry demands a polyester membrane that allows for precise surface irregularities, minimizes raw material conversion losses, and enables continuous production over extended periods, thereby improving productivity. Furthermore, the membrane used as a support for the release film must not have any adverse effects on the hardening of the release layer disposed on the membrane, and must have good adhesion to the release layer. Therefore, the first objective of this invention is to provide a polyester film whose surface micro-unevenness is controlled, exhibiting specific smoothness and excellent damage resistance. Furthermore, it can improve productivity by addressing the issue of long polyester film rolls, and consequently, it can facilitate the thin-film production of ceramic blanks during ceramic blank manufacturing. The second objective of this invention is to provide a laminated polyester film whose surface micro-unevenness is controlled, exhibiting specific smoothness and good adhesion to the release layer. [Technical Means for Solving the Problem] First, the inventors have repeatedly conducted research in view of the above-mentioned actual situation and found that if a polyester film with a specific composition is used, the micro-unevenness of the surface of the polyester film can be controlled, it has a specific smoothness, excellent damage resistance, and can improve productivity by making the polyester film roll longer. Furthermore, it can be used to make a thin-film polyester film for ceramic blanks during the manufacturing of ceramic blanks, thus completing the present invention. That is, the first present invention provides the following [1] to

[17] . Second, the inventors have repeatedly conducted research in view of the above-mentioned actual situation and found that if a laminated polyester film with a specific composition is used, the micro-unevenness of the film surface can be controlled, it has a specific smoothness, and it has good adhesion to the release layer, thus completing the present invention. That is, the present invention provides the following

[18] to

[31] . [1] A polyester film, wherein one surface (A) of the polyester film satisfies the following (11) to (13): (11) The number (Y) of protrusions 100 nm or larger is 1 per mm. 2 (12) The number of protrusions (X) less than 50 nm is 2000 per mm. 2 Above; (13) The maximum peak height (Sp) is below 60 nm. [2] As described in [1], the number (Z) of protrusions (A) above 50 nm but below 100 nm on one surface (A) of the polyester film is 100 per mm. 2 The following. [3] The polyester film as described in [1] or [2], wherein one surface (A) of the polyester film contains a nucleating agent. [4] The polyester film as described in [3], wherein the nucleating agent is a fatty acid metal salt represented by the following general formula (X), (CH 3(CH 2) n COO) m M (X) (In the above general formula (X), n is an integer of 4 or more, M is Na, Ca or Li, and m is 1 when M is Na or Li and 2 when M is Ca). [5] The polyester film described in [4] has a melting point of 140°C or higher and 220°C or lower. [6] The polyester film described in any one of [1] to [5] has a surface (A) containing fatty acid ions. [7] The polyester film described in any one of [1] to [5] has a surface (A) containing metal ions. [8] The polyester film described in any one of [1] to [5] has a surface (A) containing both fatty acid ions and metal ions. [9] The polyester film described in any one of [1] to [8] further satisfies (14) and (15) below. (14) The average surface roughness (Sa) is 1 to 20 nm; (15) The root mean square slope (Sdq) is 0.2 to 1.1.

[10] The polyester film described in any one of [1] to [9], wherein the polyester film is composed of 3 layers.

[11] The polyester film described in

[10] , wherein the intermediate layer of the polyester film contains more than 50% by mass of recycled polyester raw material.

[12] The polyester film described in

[10] or

[11] has a surface layer C on the side opposite to one of the surfaces (A) of the polyester film.

[13] The polyester film described in

[12] , wherein the surface layer C contains particles.

[14] The polyester film described in

[13] , wherein the average particle size of the particles is 0.1 to 1.5 μm.

[15] The polyester film described in any one of [1] to

[14] has a release layer on one of the surfaces (A) of the polyester film.

[16] The polyester film described in any one of [1] to

[15] is used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors.

[17] The polyester film described in any one of [1] to

[15] is used as a support for ceramic blanks in the manufacturing process of automotive ceramic capacitors.

[18] A multilayer polyester film wherein a surface (A) of the polyester film contains a nucleating agent, and a resin layer formed of a resin composition comprising (a) an adhesive resin and (b) a crosslinking agent is provided on the surface (A), wherein the surface of the resin layer satisfies the following (21) and (22): (21) the average surface roughness (Sa) is 1 to 10 nm; (22) the maximum peak height (Sp) is 150 nm or less.

[19] The multilayer polyester film described in

[18] wherein the nucleating agent is a fatty acid metal salt represented by the following general formula (X), (CH 3(CH 2) n COO) mM・・・(X) (In the above general formula (X), n is an integer of 4 or more, M is Na, Ca or Li, and m is 1 when M is Na or Li and 2 when M is Ca).

[20] The laminated polyester film described in

[18] or

[19] , wherein the ratio (Sp / Sa) of the maximum peak height (Sp) to the average surface roughness (Sa) of the resin layer surface is 50 or less.

[21] The laminated polyester film described in any one of

[18] to

[20] , wherein the adhesive resin described in the above (a) comprises polyester resin or polyvinyl alcohol resin.

[22] The laminated polyester film described in any one of

[18] to

[21] , wherein the crosslinking agent described in the above (b) comprises a melamine compound.

[23] The laminated polyester film described in any one of

[18] to

[22] , wherein the crosslinking agent described in the above (b) comprises two or more compounds.

[24] The laminated polyester film described in any one of

[18] to

[23] , wherein the polyester film is composed of 3 layers.

[25] The laminated polyester film described in

[24] , wherein the polyester film has a surface layer C on the side opposite to the aforementioned surface (A).

[26] The laminated polyester film described in

[25] , wherein the average surface roughness (Sa) of the aforementioned surface layer C is 3 nm or more and 20 nm or less.

[27] The laminated polyester film described in

[25] or

[26] , wherein the maximum peak height (Sp) of the aforementioned surface layer C is 10 nm or more and 220 nm or less.

[28] The laminated polyester film described in any one of

[18] to

[27] , wherein it has a release layer on the aforementioned resin layer.

[29] The laminated polyester film described in

[28] , wherein the aforementioned release layer contains a curable silicone resin.

[30] The multilayer polyester film described in any one of

[18] to

[29] is used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors.

[31] The multilayer polyester film described in any one of

[18] to

[29] is used as a support for ceramic blanks in the manufacturing process of automotive ceramic capacitors. [Effects of the Invention] According to the first invention, a polyester film can be provided whose surface micro-unevenness is controlled, exhibiting a specific smoothness, thus providing excellent damage resistance. Furthermore, it can improve productivity by allowing for the elongation of polyester film rolls, and consequently, facilitate the thinning of ceramic blanks during ceramic blank manufacturing. According to the second invention, a laminated polyester film can be provided whose surface micro-unevenness is controlled, exhibiting a specific smoothness, and providing good adhesion to the release layer. Moreover, the polyester film of the first invention and the laminated polyester film of the second invention possess specific smoothness, thus, for example, when used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors, they offer the advantage of reducing concerns about defects in the ceramic blanks caused by the micro-unevenness of the polyester film surface. The present invention will now be described in detail. Furthermore, in this specification, the term "A-B" used to describe numerical values ​​means "A or more and B or less" (when A < B) or "A or less and B or more" (when A > B). Also, in the present invention, a preferred combination of states is considered a more preferred state. [First Polyester Film] The first polyester film of the present invention (hereinafter also referred to as "first polyester film") is a polyester film whose surface (A) satisfies the following (11) to (13). (11) The number (Y) of protrusions of 100 nm or more is 1 per mm. 2 Below. (12) The number of protrusions (X) less than 50 nm is 2000 per mm. 2 Above. (13) The maximum peak height (Sp) is below 60 nm. In the first polyester film, one surface (A) of the polyester film refers, for example, to the side of the multilayer ceramic blank used as a support for the ceramic blank in the manufacturing process of a multilayer ceramic capacitor. By satisfying the above (11) to (13) with one surface (A) of the polyester film, the thin-film nature of the ceramic blank can be addressed, and the multilayer capacitor can be manufactured in a better state. Furthermore, from the viewpoint of using it as a support for the ceramic blank, one surface (A) of the polyester film is suitable as the surface for which the release layer is disposed. Furthermore, in the case where the first polyester film is a single layer, one surface (A) of the polyester film refers to any surface of the polyester film. Also, in the case where the first polyester film is a polyester film composed of two or more layers, it refers to any outermost layer of the polyester film. By having the above-described structure, the first polyester film can suppress the formation of wrinkles or pinholes during polyester film manufacturing, and can handle the elongation of polyester films, thus improving productivity. Furthermore, by having the above-described structure on one surface (A) of the first polyester film, the formation of pinholes caused by surface irregularities can be suppressed, thus enabling the thinning of ceramic blanks and allowing for the manufacture of multilayer capacitors in a better state. As described above, by having the above-described structure, the fine irregularities on the surface of the first polyester film are controlled, resulting in a specific smoothness and excellent damage resistance. Furthermore, it can handle the elongation of polyester film rolls, improving productivity, and further enabling the thinning of ceramic blanks during ceramic blank manufacturing. Moreover, by having the above-described structure, the first polyester film can achieve more precise control over the surface irregularities, making it better suited for manufacturing multilayer ceramic capacitors, especially when it is necessary to form thin-film ceramic blanks with a thickness (after drying) of 0.5 μm or less. The thickness of the first polyester film is preferably 19 μm or more and 38 μm or less, and more preferably 25 μm or more and 32 μm or less. In the first polyester film, the polyester film roll refers to a roll formed by winding polyester film. This roll refers to a polyester film roll wound onto a core such as a paper tube, metal tube, or plastic tube, preferably with a width of 0.2 m or more, more preferably 0.3 m or more, particularly preferably 1.0 m or more, and most preferably 1.5 m or more. There is no particular upper limit to the width of the film, but from an operational point of view, it is preferably 2.3 m or less, more preferably 2.0 m or less. Furthermore, there is no particular limitation on the length of the first polyester film wound onto this roll, but it is preferably 1000 m or more, more preferably 6000 m or more, and even more preferably 12000 m or more. (Surface Characteristics) In the first polyester film, one surface (A) of the polyester film is characterized by satisfying the following (11) to (13). (11) The number of protrusions (Y) of 100 nm or more is 1 per mm. 2 Below. (12) The number of protrusions (X) less than 50 nm is 2000 per mm. 2 Above. (13) The maximum peak height (Sp) is below 60 nm. [Number of protrusions] In the first polyester film, the number (Y) of protrusions larger than 100 nm on one surface (A) of the polyester film is 1 per mm. 2 Below. If the number of protrusions (Y) above 100 nm exceeds 1 per mm. 2 However, the unevenness of the polyester film surface can easily lead to defects such as pinholes, reducing its damage resistance. Furthermore, it cannot cope with the elongation of polyester film rolls and the thinning of ceramic blanks. From the viewpoint of improving damage resistance and coping with the elongation of polyester film rolls and the thinning of ceramic blanks, the number (Y) of protrusions (100 nm or larger) on one surface (A) of the polyester film is preferably 0 per mm. 2 the following. Furthermore, in the first polyester film, the number (X) of protrusions (less than 50 nm) on one surface (A) of the polyester film is 2000 per mm. 2 The above applies. If the number of protrusions (X) less than 50 nm is less than 2000 per mm... 2 If the membrane surface is excessively flattened, the membrane's slip properties decrease, making it prone to damage and thus reducing its damage resistance. Furthermore, it cannot cope with the elongation of polyester film rolls. From the perspective of improving damage resistance and addressing the elongation of polyester film rolls and the thinning of ceramic preforms, the number of protrusions (X) less than 50 nm on one surface (A) of the polyester film is preferably 4000 per mm. 2 The above is preferred to be 6000 pieces / mm. 2 That's all. Furthermore, from the perspective of improving damage resistance, the upper limit is preferably 40,000 per mm. 2 The following is preferred: 30,000 pieces / mm 2 The preferred value is 25,000 pieces / mm. 2 the following. Furthermore, in the first polyester film, the number (Z) of protrusions (50 nm or larger but less than 100 nm) on one surface (A) of the polyester film is preferably 100 per mm. 2 The following is preferred: 80 pieces / mm 2 The following is preferred: 60 pieces / mm 2 The following describes how, by ensuring that the number (Z) of protrusions (50 nm or more but less than 100 nm) on one surface (A) of the polyester film is within the aforementioned range, a polyester film roll with a smoother surface can be obtained. This facilitates damage resistance and makes it easier to handle the elongation of polyester film rolls and the thinning of ceramic blanks. Furthermore, the number of protrusions can be specifically measured using the method described in the examples. [Maximum Peak Height (Sp)] In the first polyester film, the maximum peak height (Sp) of one surface (A) of the polyester film must be 60 nm or less. If the maximum peak height (Sp) of one surface (A) of the polyester film is greater than 60 nm, defects such as pinholes are easily generated due to the unevenness of the polyester film surface, reducing its damage resistance. Furthermore, it cannot cope with the elongation of polyester film rolls and the thinning of ceramic blanks. In the first polyester film, from the viewpoint of improving damage resistance and coping with the elongation of polyester film rolls and the thinning of ceramic blanks, the maximum peak height (Sp) of one surface (A) of the polyester film is preferably 58 nm or less, more preferably 55 nm or less. Furthermore, there is no particular limitation on the lower limit of the maximum peak height (Sp), but from the viewpoint of improving the rollability of the polyester film, it is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 15 nm or more. Maximum peak height (Sp) is one of the surface roughness parameters (ISO 25178), representing the maximum height of the average surface from which the surface is located, and is expressed by the following formula (1). [Number 1] Furthermore, in the first polyester film, one surface (A) of the polyester film preferably satisfies the following (14) and (15): (14) The average surface roughness (Sa) is 1 to 20 nm. (15) The root mean square slope (Sdq) is 0.2 to 1.1. [Average Surface Roughness (Sa)] In the first polyester film, from the viewpoint of improving damage resistance and addressing the elongation of polyester film rolls and the thinning of ceramic blanks, the average surface roughness (Sa) of one surface (A) of the polyester film is preferably 1 to 20 nm, more preferably 1 to 15 nm, further preferably 1.5 to 10 nm, and even more preferably 2 to 8 nm. If the average surface roughness (Sa) of one surface (A) of the polyester film is 20 nm or less, defects such as pinholes caused by micro-unevennesses on the surface of the polyester film can be easily prevented, the reduction in damage resistance can be easily suppressed, and the elongation of polyester film rolls and the thinning of ceramic blanks can be easily addressed. On the other hand, if the average surface roughness (Sa) is 1 nm or more, extreme flattening of the film surface can be prevented, the reduction in film slippage can be easily suppressed, and the reduction in damage resistance can be easily addressed, and the elongation of polyester film rolls can be easily addressed. The average surface roughness (Sa) is one of the surface roughness parameters (ISO 25178). It is obtained by extending the two-dimensional Ra into three dimensions. It is obtained by dividing the volume of the part enclosed by the surface shape and the average surface by the measured area, and is calculated from the following formula (2). When the surface is set as the XY plane and the height direction is set as the Z axis, and A is defined as the area (considered as the entire image) and Z(x,y) is the height of the image point (x,y) from the surface with height 0, it is represented by the following formula (2). [Number 2] Furthermore, in the first polyester film, the ratio of the maximum peak height (Sp) to the average surface roughness (Sa) of one surface (A) of the polyester film, Sp / Sa, is preferably 15 or less, more preferably 12 or less, and even more preferably 10 or less. By making the ratio of the maximum peak height (Sp) to the average surface roughness (Sa), Sp / Sa, to 15 or less, the balance between a higher average surface roughness (Sa) and a lower maximum peak height (Sp) can be adjusted, making it easier to form thin-film ceramic preforms, thus enabling the thin-film production of ceramic preforms. While there is no particular limitation on the lower limit of the ratio of the maximum peak height (Sp) to the average surface roughness (Sa), from the viewpoint of adjusting the balance between high Sa and low Sp, it is preferably 3 or more, and more preferably 5 or more. [Root Mean Square Slope (Sdq)] In the first polyester film, from the viewpoint of improving damage resistance and addressing the issues of elongated polyester film rolls and thin-film ceramic blanks, the root mean square slope (Sdq) of one surface (A) of the polyester film is preferably 0.2 to 1.1, more preferably 0.2 to 0.8, and even more preferably 0.3 to 0.6. If the root mean square slope (Sdq) of one surface (A) of the polyester film is 1.1 or less, defects such as pinholes can be easily prevented, the reduction in damage resistance can be easily suppressed, and the thin-film ceramic blanks can be easily addressed. On the other hand, if the root mean square slope (Sdq) is 0.2 or more, extreme flattening of the film surface is prevented, the reduction in film slippage can be easily suppressed, thus suppressing the reduction in damage resistance, and the elongated polyester film rolls can be easily addressed. The root mean square slope (Sdq) is a surface roughness parameter determined according to ISO 25178, and is represented by the following formula (3). The root mean square slope (Sdq) represents the average magnitude of the local slope of the unevenness of the surface. The larger the value, the steeper the surface. [Number 3] In the first polyester film, the surface characteristics of one surface (A) of the polyester film can be adjusted, for example, by adjusting the type and content of the nucleating agent, or by controlling the conditions of the cooling roller during the manufacturing of the polyester film. (Crystallization nucleating agent) In the first polyester film, one surface (A) of the polyester film preferably contains a crystallization nucleating agent. In the first polyester film, by containing a crystallization nucleating agent on one surface (A) of the polyester film, the crystallization of the polyester resin can be easily promoted, and the surface (A) of the polyester film can easily satisfy the above-mentioned surface characteristics (11) to (13) and (14) and (15). The nucleating agent used in the first polyester film is preferably a fatty acid metal salt represented by the following general formula (X). (CH 3(CH 2) n COO) m M(X) (In the above general formula (X), n is an integer greater than 4, M is Na, Ca or Li, and m is 1 when M is Na or Li, and 2 when M is Ca) By making the nucleating agent a fatty acid metal salt represented by the above general formula (X), the crystallization of polyester resin is promoted. Furthermore, the fatty acid metal salt represented by the above general formula (X) has an affinity for polyester. Therefore, during the manufacture of polyester film, it is easy to suppress the aggregation of the nucleating agent in the molten polyester raw material, and the nucleating agent can be uniformly present in the polyester raw material. Therefore, one surface (A) of the polyester film can easily satisfy the above (11) to (13) and (14) and (15). In the above general formula (X), M represents the metal ion in the fatty acid metal salt, which is any one of Na, Ca, or Li, preferably Na. By making the metal ion any one of Na, Ca, or Li, the reduction in molecular weight of polyester resin caused by heat retention during polyester film manufacturing can be suppressed, and the elongation of polyester film rolls can be addressed. Furthermore, in the above general formula (X), n is an integer of 4 or more, preferably 6 or more but less than 35, more preferably 8 or more but less than 33, further preferably 10 or more but less than 30, and even more preferably 15 or more but less than 28. By ensuring that n is within the above range in general formula (X), the compatibility between the crystallizing nucleating agent and the polyester resin can be improved, enabling the production of longer polyester film rolls and thinner ceramic blanks. Among the fatty acid metal salts represented by the above general formula (X), specific examples of fatty acids include hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, pearlitic acid, stearic acid, nonadecanoic acid, arachidic acid, benzyl acid, and linalic acid, among which linalic acid is preferred. In the first polyester film, the melting point of the fatty acid metal salt used as a crystal nucleating agent is preferably 140°C to 220°C, more preferably 150°C to 210°C, and even more preferably 160°C to 200°C. By making the melting point of the fatty acid metal salt below 220°C, the maximum peak height (Sp) on the surface of the polyester film can be suppressed from becoming too large. Furthermore, by making the melting point above 140°C, fine irregularities can be formed on one surface (A) of the polyester film. Therefore, the above (11) to (13) can be easily satisfied, thereby easily improving the damage resistance and coping with the elongation of the polyester film and the thinning of the ceramic blank. In the first polyester film, the melting point of the fatty acid metal salt can be determined by TG-DTA (Thermogravimetric-Differential Thermal Analysis), specifically, by the method of the example. Regarding the dosage of the nucleating agent, from the viewpoint of improving treatment efficiency, relative to the membrane, it is preferably 2000 ppm or more by mass ratio, more preferably 3000 ppm or more and 28000 ppm or less, and even more preferably 5000 ppm or more and 25000 ppm or less, especially 5000 ppm or more and 20000 ppm or less. The above-mentioned nucleating agents can be used alone or in combination of two or more. In the first polyester film, one surface (A) of the polyester film preferably contains fatty acid ions. By making one surface (A) of the polyester film contain fatty acid ions, the surface (A) of the polyester film can easily satisfy the above-mentioned (11) to (13) and (14) and (15). As a fatty acid, it is preferably a fatty acid exemplified in the fatty acid metal salt of the above-mentioned crystal nucleating agent, among which, linalic acid is preferred. As for the content of fatty acid ions, it is preferably in the same range as the content of the above-mentioned crystal nucleating agent. In the first polyester film, the fatty acid ions are preferably fatty acids derived from the fatty acid metal salt of the above-mentioned crystal nucleating agent. In the first polyester film, one surface (A) of the polyester film preferably contains metal ions. By containing metal ions on one surface (A) of the polyester film, the surface (A) of the polyester film can easily satisfy the above-mentioned (11) to (13), (14), and (15). As the metal ion, it is preferably a metal ion exemplified in the fatty acid metal salt of the above-mentioned nucleating agent, among which Na ions are preferred. As the metal content, it is preferably in the same range as the content of the above-mentioned nucleating agent. In the first polyester film, the metal ions are preferably metal ions derived from the fatty acid metal salt of the above-mentioned nucleating agent. Furthermore, in this invention, one surface (A) of the polyester film preferably contains fatty acid ions and metal ions. By making one surface (A) of the polyester film contain fatty acid ions and metal ions, the surface (A) of the polyester film can easily satisfy the above-mentioned (11) to (13) and (14) and (15). As a fatty acid, it is preferably a fatty acid exemplified in the fatty acid metal salt of the above-mentioned nucleating agent, and among them, linalic acid is preferred. As the content of fatty acid ions, it is preferably in the same range as the content of the above-mentioned nucleating agent. As a metal ion, it is preferably a metal ion exemplified in the fatty acid metal salt of the above-mentioned nucleating agent, and among them, Na ions are preferred. As the content of metal, it is preferably in the same range as the content of the above-mentioned nucleating agent. In this invention, the metal ions are preferably metal ions derived from the fatty acid metal salt of the above-mentioned nucleating agent. (Polyester) In the first polyester film, polyester refers to the polyester that becomes the raw material of the polyester film, and refers to a polymer compound with ester bonds connected to the main chain. In the first polyester film, the polyester can be a homopolymer polyester or a copolyester. Specifically, a polyester obtained by polycondensation reaction of a dicarboxylic acid component and a diol component can be cited as an example. Furthermore, when the dicarboxylic acid content in the first polyester film is set to 100 mol%, it is preferable to use a polyester containing aromatic or aliphatic dicarboxylic acids at a content of more than 50 mol%. Examples of dicarboxylic acid components mentioned above 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'-biphenylenedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid and 4,4'-diphenyl ether dicarboxylic acid; or aliphatic dicarboxylic acids such as adipic acid, octanoic acid, sebacic acid, dimer acid, dodecanoic acid, cyclohexanedicarboxylic acid and their ester derivatives. Examples of the diol components mentioned above 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-cyclohexanediethanol, 1,3-cyclohexanediethanol, 1,4-hexanediethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbide, and spirodiol. When the aforementioned polyester includes homopolymeric polyesters, it is preferable to obtain it by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of the aforementioned aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic diol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanediethanol. Representative examples of polyesters include polyethylene terephthalate (PET) and polyethylene-2,6-naphthalenedicarboxylic acid (PEN). On the other hand, when the aforementioned polyester is a copolyester, it is preferable to be a copolymer containing 30 moles or less of a third component. The third component refers to components other than compounds that are the main components of the dicarboxylic acid constituent of the polyester and compounds that are the main components of the diol constituent. If it is polyethylene terephthalate, it refers to components other than terephthalic acid and ethylene glycol. Examples of dicarboxylic acid constituents in the copolyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and hydroxycarboxylic acids. Examples of diol constituents in the copolyester include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanediol, and neopentyl glycol. Furthermore, the polyester described above is preferably polyethylene terephthalate with 80 moles or more, more preferably 90 moles or more, of terephthalate units, or polyethylene-2,6-naphthalate with ethylene-2,6-naphthalate units. ≪Polyester Polycondensation Catalyst≫ Examples of polymerization catalysts used to polymerize the aforementioned polyester include antimony compounds, germanium compounds, aluminum compounds, and titanium compounds. Among these, at least one of antimony compounds and titanium compounds is preferred, and polyester obtained using a titanium compound is particularly preferred. Therefore, the polyester film preferably contains at least one of antimony compounds and titanium compounds, and more preferably contains a titanium compound. By using the aforementioned titanium compound, the number of metal-containing aggregates, i.e., so-called coarse foreign matter, originating from the titanium compound in the film can be reduced, and a first polyester film with specific surface smoothness, especially a smaller maximum peak height (Sp) on at least one side, can be obtained. The polyester constituting the outermost layer of the first polyester film (also referred to as the "surface layer," such as a surface layer for a release layer, like surface A of a polyester film) preferably uses a titanium compound as its polycondensation catalyst. The titanium atom content derived from the titanium compound in this outermost layer is preferably 3 ppm to 240 ppm, more preferably 4 ppm to 220 ppm. Within this range, the manufacturing efficiency of the polyester can be reduced while minimizing foreign matter caused by the catalyst. Furthermore, when the polyester film is a laminated polyester film, from a productive point of view, the polyester constituting the intermediate layer preferably uses an antimony compound as its polycondensation catalyst. Also, from the same point of view, the antimony compound content in the outermost layer of the first polyester film, calculated based on the antimony atom content derived from the antimony compound, is preferably 100 ppm or less. For example, surface layer A preferably contains at least one of an antimony compound and a titanium compound, and the antimony compound content in surface layer A is 100 ppm or less. At this point, surface layer A may also not contain antimony compounds. The limiting viscosity (IV) of the polyester constituting the first polyester film is preferably 0.50 dL / g or more, more preferably 0.55 dL / g or more, and even more preferably 0.60 dL / g or more. In the first polyester film, using a polyester with a limiting viscosity (IV) of 0.50 dL / g or more as the polyester constituting the polyester film increases the shear stress during polyester mixing, making it easier for the nucleating agent in the polyester resin to be highly dispersed, and thus easily ensuring that the surface properties of one surface (A) of the polyester film are within the aforementioned range. Furthermore, from the viewpoint of the flowability of the nucleating agent, the upper limit of the limiting viscosity (IV) of the polyester is preferably 1.00 dL / g or less, more preferably 0.85 dL / g or less, and even more preferably 0.75 dL / g or less. Furthermore, regarding the same viewpoint as above, when the first polyester film is composed of layers, the limiting viscosity (IV) of the polyester constituting the surface layer, specifically the outermost layer of the first polyester film (e.g., the surface layer for the release layer of the polyester film, such as surface (A) of the polyester film), is preferably 0.50 dL / g or more, more preferably 0.55 dL / g or more, and even more preferably 0.60 dL / g or more. Also, regarding the flowability of the nucleating agent, the upper limit of the limiting viscosity (IV) of the polyester constituting the surface layer is preferably 1.00 dL / g or less, more preferably 0.85 dL / g or less, and even more preferably 0.75 dL / g or less. Furthermore, when two or more polyesters with different limiting viscosities (IV) are used, "limiting viscosity (IV) of the polyester constituting the first polyester film" means the limiting viscosity (IV) of the mixed resins. (Composition of the polyester film) In the first polyester film, the polyester film may be a single-layer polyester film or a polyester film composed of two or more layers. From the viewpoint of easily controlling the surface characteristics of a surface (A) within the aforementioned range, the polyester film is preferably a polyester film composed of two or more layers, and more preferably a polyester film composed of three layers. Furthermore, in the case where the first polyester film is a polyester film composed of two or more layers, it is more preferably a three-layer structure consisting of a surface layer A, an intermediate layer B, and a surface layer C, forming an A / B / C structure. In the case where the first polyester film is a laminated polyester film consisting of two or more layers, the surface layer A preferably contains the aforementioned nucleating agent. Here, the surface layer A forms the surface layer of one surface (A) of the polyester film in the first polyester film. By containing the aforementioned nucleating agent in the laminated polyester film, the surface characteristics of one surface (A) of the polyester film can be easily controlled within the aforementioned range, thereby easily improving damage resistance and addressing the issues of elongated polyester films and thin-film ceramic blanks. From the viewpoint of improving damage resistance and addressing the issues of elongated polyester films and thin-film ceramic blanks, the content of the aforementioned nucleating agent in surface layer A, by mass ratio, is preferably 2000 ppm or more, more preferably 3000 ppm or more and 28000 ppm or less, and even more preferably 5000 ppm or more and 25000 ppm or less, especially 5000 ppm or more and 20000 ppm or less, which is even more preferred. Surface layer C is formed on the surface opposite to surface layer A. That is, the first polyester film preferably has surface layer C on the surface opposite to surface layer A, i.e., one surface (A) of the polyester film. Surface layer C preferably has an average surface roughness (Sa) and a maximum peak height (Sp) that are equal to or less than those of surface layer A; more preferably, the average surface roughness (Sa) of surface layer C is 20 nm or less, or the maximum peak height (Sp) is 60 nm or less. By ensuring that the average surface roughness (Sa) and maximum peak height (Sp) of surface layer C are within the aforementioned ranges, surface layer C can possess a rough surface required to improve operability. From the viewpoint of improving the operability and damage resistance of the first polyester film, the surface layer C preferably contains particles. Examples of such particles include: inorganic particles such as silicon dioxide, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, alumina, and titanium dioxide; cross-linked polymers such as cross-linked silicone resin particles, cross-linked acrylic resin particles, cross-linked styrene-acrylic resin particles, and cross-linked polyester particles; and organic particles such as calcium oxalate and ion exchange resins. Among these, cross-linked polymers, silicon dioxide, calcium carbonate, and alumina are preferred. Furthermore, examples of cross-linked polymers that can be used as components of organic particles include divinylbenzene polymers, ethylvinylbenzene-divinylbenzene copolymers, styrene-divinylbenzene copolymers, styrene-ethylvinylbenzene-divinylbenzene copolymers, ethylene glycol dimethacrylate polymers, styrene-ethylene glycol dimethacrylate copolymers, and methyl methacrylate-divinylbenzene copolymers. Moreover, cross-linked polymers can also be systems composed of three or more components, preferably copolymers of divinylbenzene, methylstyrene, methacrylic acid, and styrene. In surface layer C, the aforementioned particles can be a single component or can be composed of two or more components. From the viewpoint of improving the operability and damage resistance of the first polyester film, the average particle size is preferably 0.1 to 1.5 μm, more preferably 0.1 to 1.2 μm, and even more preferably 0.2 to 1.0 μm. Furthermore, the particles are preferably particles with a generally uniform average particle size and a narrow particle size distribution (possessing so-called monodispersity). As for particles with a generally uniform average particle size and a narrow particle size distribution, when the particle size distribution of such particles is defined as D10 (10% cumulative number), D50 (50% cumulative number), and D90 (90% cumulative number), it is preferable that the ratio (D90-D10) / D50 is 0.6 or less, and more preferably that it is 0.5 or less. This relationship (D90-D10) / D50 represents the non-uniformity of particle size based on D50. Particles with a ratio (D90-D10) / D50 of 0.6 or less have a steep particle size distribution with a small difference between D90 and D10, which can maintain excellent workability for the first polyester film and impart a specific smoothness, easily improving damage resistance. The particle size distribution of the above particles was determined using a laser diffraction measuring device. From the viewpoint of improving the operability and damage resistance of the first polyester film, the surface layer C may also contain two or more particles with different average particle sizes. Furthermore, the maximum value of the difference in average particle size between the two or more particles with different average particle sizes is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more. By making the difference in average particle size 0.1 μm or more, the slipperiness of the polyester film surface is easily improved, thereby easily improving the operability and damage resistance of the first polyester film. Furthermore, as the upper limit of the maximum value of the difference in average particle size, from the viewpoint of suppressing the generation of pinholes caused by unevenness, it is preferably 1.5 μm or less, more preferably 1.2 μm or less, and even more preferably 1.0 μm or less, for the purpose of making the polyester film roll longer. The intermediate layer B preferably functions as the thickest main layer. To reduce costs, it is preferable to be substantially free of particles, or to contain particles at a concentration at least lower than that of the surface layer C. Examples of particles used in the intermediate layer B can be the same substances used in the intermediate layer C, and the preferred range is also the same. Furthermore, "substantially free of particles" means not intentionally present; specifically, it refers to a particle content (particle concentration) of 200 ppm or less, more preferably 150 ppm or less. In the first polyester film, the intermediate layer B preferably contains at least 50% by mass of recycled polyester raw material, more preferably at least 70% by mass, and even more preferably at least 90% by mass, and even more preferably at 100% by mass. By including recycled polyester raw material in the intermediate layer B within the above-mentioned range, CO2 can be reduced, for example. 2. Emissions can help reduce the environmental impact. Furthermore, in the first polyester film, the polyester film is preferably configured as shown in (X) below, having a surface layer A, an intermediate layer B, and a surface layer C. By adopting this configuration, the polyester film can possess excellent treatment properties and specific surface smoothness. (X) Preferred embodiments (1) In the above A / B / C configuration, the surface layer A contains a titanium compound and a crystal nucleating agent as a fatty acid metal salt. (2) In the above (1), the surface layer C contains particles. (3) In any of the above (1) and (2), the surface layer C contains an antimony compound and / or a titanium compound, and the content of the antimony compound is less than 100 ppm. (4) In any of the above (1) to (3), when the particle size of the surface layer C reaches 10% of the cumulative number of particles is set as D10, the particle size of the cumulative number of particles reaches 50% of the cumulative number of particles is set as D50, and the particle size of the cumulative number of particles reaches 90% of the cumulative number of particles is set as D90, the ratio of (D90-D10) / D50 is less than 0.6. (5) In the above (1), the crystal nucleating agent is a sodium salt of fatty acid. In (X) above, by using polyester polycondensed with titanium compounds as a catalyst in both surface layer A and surface layer C, foreign matter caused by the catalyst can be reduced, and a specific surface smoothness can be achieved. Furthermore, by using polyester polycondensed with antimony compounds as a catalyst in intermediate layer B, polyester film can be produced efficiently. (Method for manufacturing polyester film) The following is an example of a method for manufacturing a first polyester film. First, it can be carried out by a known method as follows: raw materials, such as polyester flakes, are fed to an extruder, heated to above the melting point of each polymer, the molten polymer is extruded from a die, and cooled and solidified on a rotating cooling drum (casting drum) at a temperature below the glass transition point of the polymer to obtain an unaligned sheet in a substantially amorphous state. The unaligned sheet is then stretched in a unidirectional direction or using a stretching machine in the form of a tenter frame. At this time, the stretching temperature is usually 25 to 120°C, preferably 35 to 100°C, and the elongation ratio is usually 2.5 to 7 times, preferably 2.8 to 6 times. Then, it extends in a direction orthogonal to the extension direction of the first stage. At this time, the extension temperature is usually 50 to 140°C, and the extension ratio is usually 3.0 to 7 times, preferably 4.5 times or more, and even more preferably 4.5 to 5.0 times. Then, a heat-fixing process is performed at a temperature of 180–220°C under tension or relaxation of up to 30%, thereby obtaining a first polyester film as a biaxially aligned film. This heat-fixing process can be performed in two or more stages at different temperatures. Furthermore, cooling can also be performed in a cooling zone after the heat-fixing process. The cooling temperature is preferably higher than the glass transition temperature (Tg) of the polyester resin constituting the polyester film, and more specifically, preferably in the range of 100–160°C. This cooling can be performed in two or more stages at different temperatures. Moreover, in the above-mentioned stretching, a unidirectional stretching method in two or more stages can also be used. By combining this with the above-mentioned stretching conditions, the thickness of the surface layer (A) is increased, further promoting crystallization, thereby adjusting the uneven shape. Furthermore, by increasing the thickness of the surface layer (A) and simultaneously increasing the stretching ratio, protrusions can be formed more easily. For example, when the thickness of the first polyester film is between 19 μm and 38 μm and it consists of three layers, the desired uneven shape can be achieved by adjusting the thickness of the surface layer (A) within the range of 0.5 μm to 5 μm. Here, in the manufacturing method of the first polyester film, the crystallization mechanism and the formation mechanism of unevenness in the melt extrusion process of polyester raw material are speculated from a thermodynamic point of view. Regarding the crystallization mechanism of polyester from a thermodynamic point of view, the following discussion is made based on the following equation (Y): ΔG=-NΔg+Aσ (Y) In the above equation (Y), ΔG represents the nucleus generation free energy, N represents the volume of the nucleus, Δg represents the melting free energy, A represents the number of repeating units of the crystal, and σ represents the free energy. When a nucleating agent is added to the polyester, as shown in Figure 1, the energy barrier required to generate a primary nucleus decreases, thus increasing the crystallization rate. Therefore, multiple primary nuclei can be formed within the polyester film, thus it is speculated that the crystal size decreases accordingly. Furthermore, the formation mechanism of unevenness is discussed as follows: Considering the fact that when a polyester raw material containing a nucleating agent is melt-extruded, and the die is in close contact with the casting drum, the film surface state differs on the atmospheric side and the side in close contact with the casting drum. As shown in Figure 2, the polyester film surface on the side in close contact with the casting drum is rapidly cooled, thus inhibiting crystal growth and resulting in smaller crystals. Therefore, it is presumed that even with longitudinal and lateral extension, it is difficult to form unevenness. On the other hand, the film surface on the atmospheric side, which is not in close contact with the casting drum, is slowly cooled, thereby promoting crystal growth and resulting in larger crystals. Therefore, it is presumed that after longitudinal and lateral extension, minute unevenness will be formed. (Release Layer) The first polyester film can be used in a form having a release layer on at least one side. This release layer is preferably deposited on one surface (A) of the polyester film. That is, the first polyester film preferably has a release layer on one surface (A) of the polyester film. Therefore, for example, in the case of an A / B / C configuration, a release layer is deposited on the surface of surface layer A, resulting in a release layer / A / B / C configuration. By depositing a release layer on one surface (A) of the polyester film, an ultra-thin ceramic layer is deposited on the release layer, making it less prone to pinholes during ceramic sheet forming, which is preferable. The aforementioned release layer is deposited on the polyester film directly or via other layers. Examples of other layers include easy-adhesion coatings to improve adhesion to the first polyester film, as well as antistatic layers or anti-adhesion layers. The aforementioned release layer is formed from a release agent composition containing a release agent, but from the viewpoint of obtaining good release properties, it is particularly preferable that the release agent composition contains a silicone resin. Specifically, it is more preferable to contain a type of silicone resin with a curable silicone resin as the main component, or a modified silicone type obtained by graft polymerization with organic resins such as urethane resins, epoxy resins, and alkyd resins, or a fluorosilicone resin, etc. As the aforementioned curing silicone resin, any existing curing reaction type can be used, such as addition-type, condensation-type, thermosetting type, or ultraviolet-curing type, electron beam curing type. Furthermore, multiple types of curing silicone resins can be used in combination. Moreover, there are no particular restrictions on the coating form of the curing silicone resin when forming the release layer; it can be any of the following: dissolved in an organic solvent, aqueous emulsion, or solvent-free. The release agent composition that forms the release layer may also contain, as needed, adhesives, defoamers, coatability modifiers, tackifiers, inorganic or organic particles, organic lubricants, antistatic agents, conductive agents, ultraviolet absorbers, antioxidants, foaming agents, dyes, and pigments. The release layer is formed by coating a release agent composition onto a first polyester film, which can be either inline coating performed during the film-making process or so-called offline coating applied to a temporarily manufactured film outside the system. Methods for setting a release layer on a first polyester film include previously known coating methods such as reverse gravure coating, direct gravure coating, roller coating, die coating, bar coating, and curtain coating. There are no particular limitations on the hardening conditions for forming the release layer. When the release layer is set by offline coating, the heat treatment can usually be carried out according to the following standards: at 80°C or above for more than 10 seconds, preferably at 100-200°C for 3-40 seconds, and even more preferably at 120-180°C for 3-40 seconds. Furthermore, heat treatment and active energy line irradiation such as ultraviolet radiation can be combined as needed. Moreover, known devices and energy sources can be used as the energy source for hardening by active energy line irradiation. In terms of coatability, the coating weight (after drying) of the release layer is typically between 0.005 and 5 g / m². 2 The preferred value is 0.005–1 g / m³. 2 Furthermore, the preferred concentration is 0.005–0.1 g / m³. 2 Within this range. The coating amount (after drying) did not reach 0.005 g / m². 2 In such cases, the coating properties lack stability, and it is sometimes difficult to obtain a uniform coating. On the other hand, at more than 5 g / m 2 When applying a thick coating, the adhesion and hardening properties of the release layer itself may be reduced. Furthermore, the coating amount is calculated based on the liquid mass per unit coating time (before drying), the concentration of non-volatile components in the coating liquid, the coating width, the elongation ratio, the linear velocity, etc. [Second Laminated Polyester Film] The second laminated polyester film of the present invention (hereinafter also referred to as "second laminated polyester film") is a polyester film in which a surface (A) contains a crystallizing nucleating agent, and a resin layer formed on the surface (A) is formed of a resin composition containing (a) an adhesive resin and (b) a crosslinking agent, wherein the surface of the resin layer is a film that fully satisfies the following (21) and (22): (21) The average surface roughness (Sa) is 1 to 10 nm. (22) The maximum peak height (Sp) is 150 nm or less. In the second laminated polyester film, the resin layer surface formed on one surface (A) of the polyester film refers, for example, to the side of the laminated ceramic blank when used as a support for the ceramic blank in the manufacturing process of the laminated ceramic capacitor. By satisfying the above (21) and (22) on the resin layer surface, the thin film of the ceramic blank can be accommodated, and the laminated ceramic capacitor can be manufactured in a better state. Furthermore, from the viewpoint of using it as a support for the ceramic blank, the resin layer surface is suitable as the surface for providing the release layer. Furthermore, in the second laminated polyester film, when the polyester film is a single layer, one surface (A) of the polyester film refers to any surface of the polyester film. Also, in the second laminated polyester film, when the polyester film is a laminated polyester film consisting of two or more layers, it refers to any outermost layer of the polyester film. The second laminated polyester film, by having the above-described structure, controls the fine irregularities on the film surface, resulting in a specific smoothness. Therefore, it can be used to thin-film ceramic blanks during manufacturing. The reason why the second laminated polyester film can achieve this effect can be inferred as follows. According to the second laminated polyester film, one surface (A) of the polyester film contains a crystallizing nucleating agent, thereby forming multiple crystal nuclei in the polyester film as shown in FIG1, thus reducing the size of the formed crystals. Therefore, the second laminated polyester film can control the fine irregularities on the surface of the polyester film, and thus can also control the fine irregularities on the surface of the resin layer formed on one surface (A) of the polyester film. As a result, the surface of the resin layer can satisfy the above-described (21) and (22), and a laminated polyester film with specific smoothness can be obtained. Furthermore, by having the above-described structure, the second laminated polyester film can suppress the formation of wrinkles or pinholes during film manufacturing. Furthermore, by giving the resin layer surface the above-mentioned structure, the second laminated polyester film can suppress the generation of pinholes caused by surface irregularities, thus enabling the thin-film fabrication of ceramic blanks and allowing the manufacture of laminated ceramic capacitors in a better state. As described above, the second laminated polyester film, by having the above-described structure, can achieve more precise control over the unevenness of the film surface, and can be better used to manufacture multilayer ceramic capacitors, especially when it is necessary to form thin film ceramic blanks with a thickness (after drying) of less than 0.5 μm. The thickness of the second laminated polyester film is preferably 19 μm or more and 38 μm or less, more preferably 25 μm or more and 32 μm or less. Furthermore, the film roll formed by winding the second laminated polyester film is a film roll wound onto a core such as a paper tube, metal tube, or plastic tube, and preferably has a width of 0.2 m or more, more preferably 0.3 m or more, further preferably 1.0 m or more, and further preferably 1.5 m or more. There is no particular upper limit to the film width, but from an operational point of view, it is preferably 2.3 m or less, more preferably 2.0 m or less. Furthermore, there is no particular limitation on the length of the second laminated polyester film wound into a film roll, but it is preferably 1000 m or more, more preferably 6000 m or more, and further preferably 12000 m or more. (Surface Characteristics) In the second laminated polyester film, the surface of the resin layer is characterized by satisfying the following (21) and (22). (21) The average surface roughness (Sa) is 1 to 10 nm. (22) The maximum peak height (Sp) is less than 150 nm. (21) Average Surface Roughness (Sa) In the second laminated polyester film, the average surface roughness (Sa) of the resin layer surface must be 1 to 10 nm. If the average surface roughness (Sa) of the resin layer surface is greater than 10 nm, defects such as pinholes are easily generated due to the fine unevenness of the film surface, making it impossible to cope with the thin film formation of ceramic blanks. On the other hand, if the average surface roughness (Sa) is less than 1 nm, the film surface is too extremely flat, the film's sliding properties are reduced, and the processability is impaired. In the second laminated polyester film, from the perspective of controlling the fine unevenness of the laminated film surface to achieve specific smoothness, as well as from the perspective of improving processability and coping with the thin film formation of ceramic blanks, the average surface roughness (Sa) of the resin layer surface is preferably 1 to 8 nm, more preferably 1.5 to 5 nm, and even more preferably 2 to 4 nm. Furthermore, the average surface roughness (Sa) of the second laminated polyester film is obtained in the same manner as the first polyester film described above, and is expressed by the above formula (2). (22) Maximum Peak Height (Sp) In the second-layer laminated polyester film, the maximum peak height (Sp) on the surface of the resin layer must be 150 nm or less. If the maximum peak height (Sp) on the surface of the resin layer is greater than 150 nm, defects such as pinholes are easily generated due to the fine unevenness of the film surface, making it unsuitable for thin-film processing of ceramic preforms. From the viewpoint of thin-film processing of ceramic preforms, the maximum peak height (Sp) on the surface of the resin layer in the second-layer laminated polyester film is preferably 140 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. Furthermore, there is no particular limitation on the lower limit of the maximum peak height (Sp), but from the viewpoint of improving the rollability of the film, it is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 15 nm or more. Furthermore, the maximum peak height (Sp) in the second laminated polyester film is obtained in the same manner as the first polyester film, and is expressed by the above formula (1). Furthermore, in the second laminated polyester film, the relationship between the average surface roughness (Sa) and the maximum peak height (Sp) of the resin layer surface, specifically the ratio of the maximum peak height (Sp) to the average surface roughness (Sa), Sp / Sa, is preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. By making the ratio of the maximum peak height (Sp) to the average surface roughness (Sa) Sp / Sa less than 50, the maximum peak height (Sp) can be controlled while maintaining the average surface roughness (Sa). The fine irregularities on the surface of the second laminated polyester film are controlled, ensuring processability and providing a specific smoothness. As a result, the second laminated polyester film can be easily formed into thin-film ceramic preforms, thus enabling the thin-film production of ceramic preforms. Furthermore, there is no particular limitation on the lower limit of the ratio of maximum peak height (Sp) to average surface roughness (Sa), but from the viewpoint of controlling the fine irregularities on the surface of the second laminated polyester film, ensuring processability and setting a specific smoothness, it is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. In the second laminated polyester film, the surface characteristics of the resin layer can be adjusted, for example, by adjusting the type and content of the nucleating agent contained in one surface (A) of the polyester film, or by controlling the conditions of the cooling rollers during film manufacturing. Furthermore, it can also be adjusted by adjusting the type and content of the compounds contained in the resin layer formed on one surface (A) of the polyester film, or by controlling the thickness of the resin layer. <Polyester Film> The second laminated polyester film is characterized in that one surface (A) of the polyester film (hereinafter also referred to as "second polyester film") contains a crystallizing nucleating agent. (Crystallization nucleating agent) The crystallization nucleating agent used in the second laminated polyester film is preferably a fatty acid metal salt represented by the above general formula (X) exemplified in the first polyester film. By using a fatty acid metal salt represented by the above general formula (X) as the nucleating agent, the crystallization of polyester resin is promoted. Furthermore, during the manufacture of the polyester film, the aggregation of the nucleating agent in the molten polyester raw material can be easily suppressed. As a result, the nucleating agent can be uniformly present in the polyester raw material, and thus the micro-unevenness of one surface (A) of the polyester film is controlled, and the surface of the resin layer formed on one surface (A) of the polyester film can satisfy the above (21) and (22). In the second laminated polyester film, M in the above general formula (X) represents a metal ion in the fatty acid metal salt, which is any one of Na, Ca, or Li, preferably Na. By making the metal ion any one of Na, Ca, or Li, the decrease in molecular weight of the polyester resin caused by heat retention during polyester film manufacturing can be suppressed. Furthermore, in the second laminated polyester film, n in the above general formula (X) is an integer of 4 or more, preferably 6 or more and 35 or less, more preferably 8 or more and 33 or less, further preferably 10 or more and 30 or less, and further preferably 15 or more and 28 or less. By keeping n within the above range in the general formula (X), the compatibility between the nucleating agent and the polyester resin can be improved, thus enabling the thin-film formation of ceramic blanks. Also, in the second laminated polyester film, as a specific example of the fatty acid in the fatty acid metal salt represented by the above general formula (X), the fatty acid exemplified in the first polyester film can be used, wherein linalic acid is preferred. In the second laminated polyester film, the melting point of the fatty acid metal salt used as a nucleating agent is preferably 140°C to 220°C, more preferably 150°C to 210°C, and even more preferably 160°C to 200°C. By setting the melting point of the fatty acid metal salt to 220°C or lower, the maximum peak height (Sp) on the surface of the polyester film can be suppressed from becoming too large. Furthermore, by setting the melting point to 140°C or higher, fine irregularities can be formed on one surface (A) of the polyester film. Therefore, the surface of the resin layer formed on one surface (A) of the polyester film can easily meet the above-mentioned (21) and (22), and thus the fine irregularities on the surface of the second laminated polyester film are controlled, resulting in a specific smoothness. As a result, the thin film formation of ceramic blanks can be easily handled. In the second laminated polyester film, the melting point of the fatty acid metal salt can be determined by thermogravimetric-differential thermal simultaneous measurement (TG-DTA), specifically, by the method of the example. Regarding the dosage of the nucleating agent, from the perspective of controlling the micro-unevenness of the surface of the second laminated polyester film and setting a specific smoothness, and from the perspective of improving the processing, it is preferably 2000 ppm or more by mass ratio relative to the film, more preferably 4000 ppm or more and 25000 ppm or less, and even more preferably 6000 ppm or more and 20000 ppm or less, especially 8000 ppm or more and 15000 ppm or less, which is even more preferred. The above-mentioned nucleating agents can be used alone or in combination of two or more. (Polyester) In the second laminated polyester film, polyester refers to the polyester that becomes the raw material of the second polyester film. In the second laminated polyester film, the polyester can be a homopolymer polyester or a copolymer polyester. Specifically, polyester obtained by polycondensation reaction of dicarboxylic acid component and diol component can be cited as an example. Furthermore, when the dicarboxylic acid content in the second laminated polyester film is set to 100 mol%, it is preferable to use a polyester containing aromatic or aliphatic dicarboxylic acids at a content of more than 50 mol%. As the dicarboxylic acid component mentioned above, examples can be the same as those exemplified in the first polyester film. Examples of diol components mentioned above may be those identical to those mentioned in the first polyester film. When the aforementioned polyester comprises a homopolymeric polyester, it is preferable to obtain it by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of the aforementioned aromatic dicarboxylic acid may be the same as those exemplified in the first polyester film described above. On the other hand, when the aforementioned polyester is a copolyester, it is preferable to be a copolymer containing 30 moles or less of a third component. The third component refers to components other than the compounds that are the main components of the dicarboxylic acid component constituting the polyester and the compounds that are the main components of the diol component. If it is polyethylene terephthalate, it refers to components other than terephthalic acid and ethylene glycol. Examples of the dicarboxylic acid component of the copolyester that are the same as those exemplified in the first polyester film described above can be cited. Examples of the diol component of the copolyester that are the same as those exemplified in the first polyester film described above can also be cited. Furthermore, the polyester described above is preferably polyethylene terephthalate with 80 moles or more, more preferably 90 moles or more, of terephthalate units, or polyethylene-2,6-naphthalate with ethylene-2,6-naphthalate units. Furthermore, when ethylene glycol is used as a raw material to manufacture (condensation) polyester, diethylene glycol is usually produced as a byproduct. In this specification, this diethylene glycol is referred to as byproduct diethylene glycol. The amount of diethylene glycol byproduct from ethylene glycol varies depending on the type of condensation polymerization, but it is generally around 5 mol% or less in ethylene glycol. In the second laminated polyester film, after considering diethylene glycol of 5 mol% or less as byproduct diethylene glycol, this byproduct diethylene glycol is also included in the ethylene glycol and distinguished from the copolymer components. On the other hand, depending on the diethylene glycol content, more specifically, when diethylene glycol is present in quantities exceeding 5 mol%, diethylene glycol is treated as a copolymer component rather than byproduct diethylene glycol. ≪Polyester Polycondensation Catalyst≫ Examples of polycondensation catalysts for the above-mentioned polyester polycondensation include antimony compounds, germanium compounds, aluminum compounds, and titanium compounds. Among these, at least one of antimony compounds and titanium compounds is preferred. Therefore, the polyester film preferably contains at least one of antimony compounds and titanium compounds. The polyester constituting the outermost layer of the second polyester film (also referred to as the "surface layer," such as the surface layer of the polyester film (A) for the deposition of resin layers) preferably uses a titanium compound as its polycondensation catalyst. By using a titanium compound, the number of metal aggregates originating from the titanium compound in the film, i.e., so-called coarse foreign matter, can be reduced, thus lowering the maximum peak height (Sp) of the second laminated polyester film and providing a certain smoothness. The titanium content originating from the titanium compound in the outermost layer is preferably 1 ppm to 40 ppm, more preferably 2 ppm to 20 ppm, and even more preferably 3 ppm to 10 ppm. If it is within the above range, the foreign matter caused by the catalyst can be reduced without reducing the manufacturing efficiency of the polyester. Furthermore, when the polyester film is a laminated structure, from a production point of view, the polyester constituting the intermediate layer preferably does not use a titanium compound as its polycondensation catalyst. Furthermore, from the same perspective, the content of antimony compound in the outermost layer of the second polyester film is preferably less than 100 ppm. For example, the surface layer A is preferably composed of at least one of antimony compound and titanium compound, and the content of antimony compound in surface layer A is less than 100 ppm. In this case, surface layer A may also be free of antimony compound. The limiting viscosity (IV) of the polyester constituting the second polyester film is preferably 0.50 dL / g or higher, more preferably 0.55 dL / g or higher, and even more preferably 0.60 dL / g or higher. In the second laminated polyester film, using a polyester with a limiting viscosity (IV) of 0.40 dL / g or higher as the polyester constituting the polyester film increases the shear stress during polyester mixing, facilitates the high dispersion of the nucleating agent in the polyester resin, controls the fine irregularities on one surface (A) of the polyester film, and easily ensures that the surface characteristics of the resin layer formed on one surface (A) of the polyester film are within the aforementioned range. Furthermore, from the viewpoint of the flowability of the nucleating agent, the upper limit of the limiting viscosity (IV) of the polyester is preferably 1.00 dL / g or lower, more preferably 0.85 dL / g or lower, and even more preferably 0.75 dL / g or lower. Furthermore, regarding the same viewpoint as above, when the second polyester film has a laminated structure, the limiting viscosity (IV) of the polyester constituting the surface layer, specifically the outermost layer of the second polyester film (e.g., the surface layer of the polyester film such as surface (A) for the laminated resin layer), is preferably 0.50 dL / g or more, more preferably 0.55 dL / g or more, and even more preferably 0.60 dL / g or more. Also, regarding the flowability of the nucleating agent, the upper limit of the limiting viscosity (IV) of the polyester constituting the surface layer is preferably 1.00 dL / g or less, more preferably 0.85 dL / g or less, and even more preferably 0.75 dL / g or less. Furthermore, when two or more polyesters with different limiting viscosities (IV) are used, "limiting viscosity (IV) of the polyester constituting the second polyester film" means the limiting viscosity (IV) of the mixed resins. (Composition of Polyester Film) In the second laminated polyester film, the polyester film can be a single-layer polyester film or a polyester film composed of two or more layers. From the viewpoint of easily controlling the surface characteristics of the resin layer formed on a surface (A) within the aforementioned range, the polyester film is preferably a polyester film composed of two or more layers, and more preferably a polyester film composed of three layers. Furthermore, in the case where the polyester film in the second laminated polyester film is a polyester film composed of two or more layers, it is preferably a three-layer structure consisting of a surface layer A, an intermediate layer B, and a surface layer C, forming an A / B / C structure. In the second laminated polyester film, when the polyester film is a laminated polyester film consisting of two or more layers, the surface layer A preferably contains the aforementioned nucleating agent. Here, the aforementioned surface layer A is the surface layer that forms one surface (A) of the polyester film in the second laminated polyester film. By containing the aforementioned nucleating agent in the surface layer A of the laminated polyester film, the surface characteristics of the resin layer formed on one surface (A) of the polyester film can be easily controlled within the aforementioned range, thus easily enabling the thin-film formation of ceramic blanks. From the perspective of controlling the micro-unevenness of the surface of the second laminated polyester film and setting a specific smoothness, and from the perspective of improving the processing, the content of the above-mentioned nucleating agent in the surface layer A is preferably 2000 ppm or more by mass ratio, more preferably 4000 ppm or more and 25000 ppm or less, further preferably 6000 ppm or more and 20000 ppm or less, and further preferably 8000 ppm or more and 15000 ppm or less. Surface layer C is formed on the surface opposite to surface layer A. That is, the second polyester film preferably has surface layer C on the surface opposite to surface layer A, i.e., one surface (A) of the polyester film. Surface layer A preferably has an average surface roughness (Sa) and a maximum peak height (Sp) that are equal to or less than that of surface layer C. The average surface roughness (Sa) of surface layer C is preferably 3 nm to 20 nm, more preferably 4 nm to 18 nm, and even more preferably 5 nm to 15 nm. Furthermore, the maximum peak height (Sp) of surface layer C is preferably 10 nm to 220 nm, more preferably 30 nm to 200 nm, and even more preferably 50 nm to 180 nm. By ensuring that the average surface roughness (Sa) or maximum peak height (Sp) of surface layer C is within the above ranges, surface layer C can possess the rough surface required to improve operability, thus easily improving the processing quality of the second laminated polyester film. From the viewpoint of improving the operability of the second polyester film, the surface layer C preferably contains particles. Examples of such particles include: inorganic particles such as silicon dioxide, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, alumina, and titanium dioxide; cross-linked polymers such as cross-linked silicone resin particles, cross-linked acrylic resin particles, cross-linked styrene-acrylic resin particles, and cross-linked polyester particles; and organic particles such as calcium oxalate and ion exchange resins. Among these, cross-linked polymers, silicon dioxide, calcium carbonate, and alumina are preferred, and silicon dioxide is more preferred. Furthermore, examples of cross-linked polymers that can be used as components of organic particles include divinylbenzene polymers, ethylvinylbenzene-divinylbenzene copolymers, styrene-divinylbenzene copolymers, styrene-ethylvinylbenzene-divinylbenzene copolymers, ethylene glycol dimethacrylate polymers, styrene-ethylene glycol dimethacrylate copolymers, and methyl methacrylate-divinylbenzene copolymers. Moreover, cross-linked polymers can also be systems composed of three or more components, preferably copolymers of divinylbenzene, methylstyrene, methacrylic acid, and styrene. In surface layer C, the aforementioned particles can be a single component or can be composed of two or more components. From the viewpoint of improving the operability of the second polyester film, the average particle size is preferably 0.1 to 1.5 μm, more preferably 0.1 to 1.2 μm, and even more preferably 0.2 to 1.0 μm. Furthermore, the particles are preferably particles with a generally uniform average particle size and a narrow particle size distribution (possessing so-called monodispersity). As for particles with a generally uniform average particle size and a narrow particle size distribution, when the particle size distribution of such particles is defined as D10 representing 10% of the cumulative particle size, D50 representing 50% of the cumulative particle size, and D90 representing 90% of the cumulative particle size, it is preferable that the ratio (D90-D10) / D50 is 0.4 or less, and more preferably that it is 0.3 or less. This relationship (D90-D10) / D50 represents the non-uniformity of particle size based on D50. Particles with a ratio (D90-D10) / D50 of 0.4 or less have a steep particle size distribution with a small difference between D90 and D10, which can maintain excellent workability for the second polyester film and impart very specific smoothness. The particle size distribution of the above particles was determined using a laser diffraction measuring device. From the viewpoint of improving the operability of the second polyester film, the surface layer C may also contain two or more particles with different average particle sizes. In this case, the maximum value of the difference in average particle size between the two or more particles with different average particle sizes is preferably 0.1 μm or more, more preferably 0.2 μm or more, and more preferably 0.3 μm or more. By making the difference in average particle size 0.1 μm or more, the slippage of the polyester film surface can be easily improved, thereby easily improving the operability of the second polyester film. Furthermore, as an upper limit of the maximum value of the difference in average particle size, from the viewpoint of suppressing the generation of pinholes caused by unevenness, it is preferably 1.5 μm or less, more preferably 1.2 μm or less, and more preferably 1.0 μm or less. The intermediate layer B preferably functions as the thickest main layer. To reduce costs, it is preferable to be substantially free of particles, or to contain particles at a concentration at least lower than that of the surface layer C. Examples of particles used in the intermediate layer B can be the same as those used in the intermediate layer C, and the preferred range is also the same. Furthermore, "substantially free of particles" means not intentionally present; specifically, it refers to a particle content (particle concentration) of 200 ppm or less, more preferably 150 ppm or less. In the second laminated polyester film, the intermediate layer B may contain recycled polyester raw materials. In this case, it is preferable to contain 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, and even more preferably 100% by mass. By including recycled polyester raw materials in the intermediate layer B within the above-mentioned range, CO2 content can be reduced, for example. 2. Emissions can help reduce the environmental impact. Furthermore, the second polyester film is preferably configured as shown in (W) below, comprising a surface layer A, an intermediate layer B, and a surface layer C. By employing this configuration, the second laminated polyester film can possess excellent treatment properties and surface smoothness. (W) Preferred embodiments (1) In the above A / B / C configuration, the surface layer A contains a titanium compound and a crystal nucleating agent as a fatty acid metal salt. (2) In the above (1), the surface layer C contains particles. (3) In any of the above (1) and (2), the surface layer C contains an antimony compound and / or a titanium compound, and the content of the antimony compound is less than 100 ppm. (4) In any of the above (1) to (3), when the particle size of the particles in the surface layer C reaches 10% and is set as D10, the particle size of the particles reaching 50% and is set as D50, and the particle size of the particles reaching 90% and is set as D90, the ratio of (D90-D10) / D50 is less than 0.4. (5) In the above (1), the crystal nucleating agent is a sodium salt of fatty acid. In the above (W), by using polyester polycondensed with titanium compounds as a catalyst in both surface layer A and surface layer C, foreign matter caused by the catalyst can be reduced, resulting in higher surface smoothness. Furthermore, by using polyester polycondensed with antimony compounds as a catalyst in intermediate layer B, polyester film can be produced efficiently. (Manufacturing method of the second polyester film) As one example of the manufacturing method of the second polyester film, an example of the same manufacturing method as that exemplified in the first polyester film can be given. When manufacturing a second polyester film, for example, if the thickness of the second polyester film is 19 μm or more and 38 μm or less and it consists of 3 layers, the surface layer A can be adjusted to the desired uneven shape by adjusting the thickness of the surface layer A within the range of 0.5 μm to 5 μm. It is also easy to adjust the surface characteristics of the resin layer formed on the surface (A) to the desired uneven shape. In the manufacturing method of the second polyester film, similarly to the case of the first polyester film, the crystallization mechanism and the formation mechanism of the unevenness of the polyester are speculated from a thermodynamic point of view in the melt extrusion process of the polyester raw material. <Resin Layer> The second laminated polyester film is characterized in that a resin layer (hereinafter referred to as "the resin layer") formed of a resin composition comprising (a) an adhesive resin and (b) a crosslinking agent is provided on one surface (A) of the polyester film. By including the above-mentioned compounds (a) and (b) in the composition, adverse effects such as inhibition of hardening of the release layer disposed on the resin layer can be suppressed, and the adhesion to the release layer can be improved. (Adhesive Resin) There are no particular limitations on the adhesive resin used as compound (a) above, and previously known adhesive resins can be used. Examples of adhesive resin (a) include: polyester resin, (meth)acrylic resin, polyurethane resin, polyethylene resin (polyvinyl alcohol resin, vinyl chloride-vinyl acetate copolymer, etc.), polyalkylene glycol, polyalkylimide, methylcellulose, hydroxycellulose, starch, etc. Among these, from the viewpoint of film-forming properties or adhesion to the polyester film, it is preferable to use any one of polyester resin, (meth)acrylic resin, polyurethane resin, and polyvinyl alcohol resin. From the viewpoint of suppressing the influence on the release layer disposed on this resin layer (e.g., hardening inhibition), it is more preferable to include polyester resin or polyvinyl alcohol resin. In this composition, adhesive resin (a) can be used alone or in combination with two or more. Polyester resins can be categorized by the following main components: polycarboxylic acids and polyhydroxy compounds. Specifically, polycarboxylic acids may include: terephthalic acid, isophthalic acid, phthalic acid, phthalic acid, 4,4'-biphenyl dicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfonyl terephthalic acid, 5-sodium sulfonyl isophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, pyromellitic acid, pyromellitic tetracarboxylic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, potassium trimellitic acid monophosphate, and their ester-forming derivatives. As polyhydroxy compounds, the following can be used: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentanediol, 1,4-cyclohexanediol, terephthalic acid, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(ethylene oxide glycol), dimethylolpropionic acid, glycerol, trimethylolpropane, sodium dimethylol ethyl sulfonate, potassium dimethylolpropionate, etc. Polyester resins can be synthesized by conventional polycondensation reactions, provided that one or more of these compounds are appropriately selected. Furthermore, it is preferable to use sulfoisophthalic acids, such as 5-sodium sulfoisophthalic acid, which is one part of the aforementioned polycarboxylic acid, to copolymerize and introduce sulfonic acid groups into the polyester backbone, thereby neutralizing and hydrophilizing it. The amount of copolymerization relative to the total polycarboxylic acid is typically 1–13 mol%, preferably 3–10 mol%, and even more preferably 5–9 mol%. By appropriately introducing sulfonic acid groups, the water dispersion stability can be further improved. ≪(Meth)acrylic resins≫ Meth)acrylic resins refer to polymers containing polymerizable monomers including acrylic and methacrylic monomers. These can also be homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Meth)acrylic polymers are polymers having structural units derived from (meth)acrylic acid or alkyl (meth)acrylic esters. Meth)acrylic polymers can be at least one polymer selected from (meth)acrylic acid and alkyl (meth)acrylic esters, or copolymers selected from at least one of these polymers with at least one monomer other than these, such as styrene or styrene derivatives, or monomers containing hydroxyl groups. Furthermore, copolymers of these polymers with other polymers (e.g., polyesters, polyurethanes, etc.) are also included. Examples include block copolymers and graft copolymers. That is, (meth)acrylic resins can also be (meth)acrylic acid-modified polyester resins or (meth)acrylic acid-modified polyurethane resins. Alternatively, polymers (as in the case of a mixture of polymers) obtained by polymerizing polymeric monomers in a polyester solution or polyester dispersion are also included. Similarly, polymers (as in the case of a mixture of polymers) obtained by polymerizing polymeric monomers in a polyurethane solution or polyurethane dispersion are also included. Polymers (as in the case of a mixture of polymers) obtained by polymerizing polymeric monomers in other polymer solutions or dispersions in the same manner are also included, and these are also considered (meth)acrylic acid modified polyester resins or (meth)acrylic acid modified polyurethane resins in this specification. Furthermore, the aforementioned polyesters and polyurethanes used in (meth)acrylic resins may be appropriately selected from those exemplified as polyesters and polyurethanes used in (a) adhesive resins. Also, (meth)acrylic resins may contain hydroxyl or amino groups to further improve adhesion to the polyester film. There are no particular limitations on the aforementioned polymerizable monomers. Examples of particularly representative compounds include: various carboxyl-containing monomers such as acrylic acid, methacrylic acid, butenoic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid, and their salts; various hydroxyl-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutyl hydroxy fumarate, and monobutyl hydroxy fumarate; and methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and lauryl (meth)acrylate. Various alkyl methacrylates; nitrogen-containing monomers such as methacrylamide, diacetone acrylamide, or methacrylonitrile; nitrogen-containing monomers containing hydroxyl groups such as N-hydroxymethylmethacrylamide; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, and vinyltoluene; various vinyl esters such as vinyl propionate; various silicon-containing polymeric monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; various halogenated vinyl groups such as vinyl chloride and vinylidene chloride; and various conjugated dienes such as butadiene. Of the aforementioned (meth)acrylic resins, a polymer is preferably formed by polymerizing polymerizable monomers containing acrylic and methacrylic monomers, and more preferably, the polymerizable monomers contain alkyl (meth)acrylic esters. Furthermore, the composition containing the (meth)acrylic resin is preferably prepared as a coating liquid by diluting it with a solvent as described below, wherein the solvent is preferably water (50% by mass or more) as the main solvent. That is, when the coating liquid is aqueous, from the viewpoint of easy dissolution or dispersion, the polymerizable monomers preferably have hydrophilic groups such as hydroxyl or carboxyl groups. Therefore, the acrylic resin is also preferably a polymer formed by polymerizing polymerizable monomers containing alkyl (meth)acrylic esters, and monomers containing hydroxyl groups, carboxyl groups, or other hydrophilic monomers. Furthermore, the acrylic resin may also be, for example, an emulsified polymer formed by polymerizing polymerizable monomers in the presence of a surfactant. Polyurethane resin is a polymer compound containing intramolecular urethane bonds, preferably water-dispersible or water-soluble. In the second laminated polyester film, it can be a single type or a combination of two or more types. To impart water dispersibility or water solubility, it is generally preferred to introduce hydrophilic groups such as hydroxyl, carboxyl, sulfonic acid, sulfonyl, phosphate, and ether groups into the polyurethane resin. Among the aforementioned hydrophilic groups, carboxyl or sulfonic acid groups are particularly preferred in terms of the adhesion between the resin layer and the polyester film. One method for producing polyurethane resin involves the reaction of a hydroxyl-containing compound with an isocyanate. Polyols are preferably used as the hydroxyl-containing compound, such as polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, and acrylic polyols. These compounds can be used alone or in combination. Examples of polyether polyols include: polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol. Polyester polyols can be exemplified by those obtained from the reaction of polycarboxylic acids or their anhydrides with polyols. Examples of polycarboxylic acids include: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc. Examples of polyols include: ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-propanediol, etc. -Octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, dimethylolcyclohexane, dimethylbenzene, dihydroxyethoxybenzene, alkyldialkylolamine, lactone diol, etc. Examples of polycarbonate-based polyols include polycarbonate diols obtained by reacting polyols with dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, etc., through a dealcoholization reaction, such as poly(1,6-hexyl) carbonate and poly(3-methyl-1,5-pentyl) carbonate. Of the above, polyester polyols are preferred. Examples of polyisocyanate compounds used to obtain polyurethane resins include: aromatic diisocyanates such as toluene diisocyanate, phenyl diisocyanate, methylene diphenyl diisocyanate, phenyl diisocyanate, naphthalene diisocyanate, and benzyltoluidine diisocyanate; aliphatic diisocyanates having an aromatic ring such as α,α,α',α'-tetramethylphenyl diisocyanate; aliphatic diisocyanates such as methylene diisocyanate, propyl diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl diisocyanate. These compounds can be used alone or in combination. Chain extenders can be used in the synthesis of polyurethane resins. As a chain extender, there are no particular restrictions as long as it has two or more active groups that react with isocyanate groups. Generally speaking, chain extenders with two hydroxyl or amine groups can be used. Examples of chain extenders having two hydroxyl groups include: aliphatic diols such as ethylene glycol, propylene glycol, and butanediol; aromatic diols such as benzenediethanol and dihydroxyethoxybenzene; ester diols such as neopentyl glycol hydroxypentyl ester; and other diols. Examples of chain extenders having two amino groups include: aromatic diamines such as toluenediamine, phenylenediamine, and diphenylmethanediamine; aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine; and alicyclic diamines such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, 1,4-diaminocyclohexane, and 1,3-diaminomethylcyclohexane. Polyvinyl alcohol (PVA) based resins are compounds containing a polyvinyl alcohol moiety. This includes modified compounds obtained by partially acetalizing or butyraldehyde polyvinyl alcohol resins, and previously known PVA based resins can be used. The degree of polymerization of PVA based resins is not particularly limited, but is generally above 100, preferably in the range of 300 to 40,000. Setting the degree of polymerization to above 100 easily improves the water resistance of the resin layer. Furthermore, the degree of saponification of PVA based resins is not particularly limited, but in practical applications, a polyvinyl acetate saponification of 70 mol% or more, preferably 70 to 99.9 mol%, more preferably 80 to 97 mol%, and even more preferably 86 to 95 mol% is typically used. The content of compound (a) in this composition, based on its proportion to all non-volatile components in the composition, is preferably in the range of 10-80% by mass, more preferably 15-70% by mass. From the viewpoint of film-forming properties or adhesion to polyester film, it is preferable to set this content to 10% by mass or more. Furthermore, when this content exceeds 80% by mass, insufficient film strength may result. (Crosslinking Agent) There are no particular limitations on the crosslinking agent used in compound (b) above; previously known crosslinking agents can be used. Examples include melamine compounds, epoxy compounds, azirzoline compounds, carbodiimide compounds, isocyanate compounds, and silane coupling compounds. From the viewpoint of improving the strength of the resin layer or improving adhesion to the polyester film, it is preferable to include at least one selected from epoxy compounds and melamine compounds, and more preferably, melamine compounds. Furthermore, from the same viewpoint, it is also preferable to include two or more compounds as crosslinking agents. When two or more compounds are included as crosslinking agents, it is preferable to include at least an epoxy compound and a melamine compound. Melamine compounds are compounds that have a melamine backbone. Examples include: hydroxyalkylated melamine derivatives, compounds formed by partially or completely etherifying an alcohol with a hydroxyalkylated melamine derivative, and mixtures thereof. Examples of hydroxyalkylation include hydroxymethylation, hydroxyethylation, hydroxyisopropylation, hydroxyn-butylation, and hydroxyisobutylation. From a reactivity point of view, hydroxymethylation is preferred. Alcohols used for etherification include methanol, ethanol, isopropanol, n-butanol, and isobutanol, with methanol being the most preferred. Furthermore, the melamine compound can be any of a monomer or a polymer of dimers or more, or a mixture thereof. Additionally, compounds formed by partial co-condensation of melamine with respect to urea can also be used. To improve the reactivity of the melamine compound, a catalyst can be further used in this composition. ≪Epoxy Compounds≫ Epoxy compounds are compounds containing epoxy groups within their molecules. Examples include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerol, polyglycerol, and bisphenol A, as well as polyepoxy compounds, diepoxy compounds, and monoepoxy compounds. Examples of polyepoxy compounds include: sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyltris(2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples of diepoxy compounds include: neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether. Examples of monoepoxide compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether; N,N,N',N'-tetraglycidyl-m-phenylenediamine and 1,3-bis(N,N-diglycidylamino)cyclohexane, which are glycidylamine compounds. From the viewpoint of improving the adhesion of the resin layer to the polyester film, polyether-based epoxy compounds are preferred. Furthermore, regarding the amount of epoxy groups, multifunctional polyepoxide compounds with three or more functions are preferred over difunctional ones. **Acetazolino compounds** Acetazolino compounds are compounds containing an acezoline group within their molecules, preferably polymers containing an acezoline group. They can be prepared by polymerization of a monomer containing an addition-polymerizable acezoline group, either alone or with other monomers. Examples of monomers containing an addition-polymerizable acezoline group include 2-vinyl-2-acezoline, 2-vinyl-4-methyl-2-acezoline, 2-vinyl-5-methyl-2-acezoline, 2-isopropenyl-2-acezoline, 2-isopropenyl-4-methyl-2-acezoline, and 2-isopropenyl-5-ethyl-2-acezoline, and mixtures of one or more of these monomers can be used. Among these, 2-isopropenyl-2-acezoline is readily available industrially and is therefore preferred. Other monomers are simply monomers capable of copolymerizing with monomers containing addition-polymerizable azolinyl groups; there are no restrictions. Examples include (meth)acrylates such as alkyl methacrylates (as alkyl groups, there are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, 2-ethylhexyl, and cyclohexyl); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, iconic acid, maleic acid, fumaric acid, butenoic acid, styrene sulfonic acid, and their salts (sodium salts, potassium salts, ammonium salts, tertiary amine salts, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; and (meth)acrylamide, N-alkyl... Unsaturated amides such as methyl (meth)acrylamide and N,N-dialkyl (meth)acrylamide (as alkyl groups, there are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, 2-ethylhexyl, cyclohexyl, etc.); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride and vinylidene chloride; α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene, etc., may be used, and one or more of these monomers may be used. Furthermore, methazolinone compounds may have polyoxyalkylene chains such as polyethylene oxide chains; for example, (meth)acrylates having polyoxyalkylene chains may be used as other monomers. ≪Carbodiamide compounds≫ Carbodiamide compounds refer to compounds having a carbodiamide structure, which is a compound having one or more carbodiamide structures in the molecule. However, for better adhesion between the resin layer and the polyester film, polycarbodiamide compounds having two or more carbodiamide structures in the molecule are preferred. Carbodiimide compounds can be synthesized using previously known techniques, generally through the condensation reaction of diisocyanate compounds. There are no particular limitations on the diisocyanate compounds used; any of the aromatic or aliphatic systems can be used. Examples include: toluene diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, phenyl diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane 4,4'-diisocyanate. Furthermore, without compromising the integrity of the second-layer polyester film, surfactants or hydrophilic monomers such as quaternary ammonium salts of polyepoxides, dialkylamino alcohols, and hydroxyalkyl sulfonates can be added to improve the water solubility or water dispersibility of the polycarbodiimide compound. Isocyanate compounds refer to isocyanates, or compounds with isocyanate derivative structures, represented by block isocyanates. Examples of isocyanates include: aromatic isocyanates such as toluene diisocyanate, phenyl dimethyl diisocyanate, methylene diphenyl diisocyanate, phenyl diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates with aromatic rings such as α,α,α',α'-tetramethylphenyl dimethyl diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propyl diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis(4-cyclohexyl isocyanate), and isopropylidene dicyclohexyl diisocyanate. Furthermore, examples can also be given of polymers or derivatives of such isocyanates, such as biuret compounds, isocyanurate compounds, urea diketides, and carbodiimide modifiers. These can be used alone or in combination. Among the aforementioned isocyanates, aliphatic or alicyclic isocyanates are preferred over aromatic isocyanates to avoid yellowing caused by ultraviolet light. When used as a block isocyanate, the end-capping agents include, for example, bisulfites; phenolic compounds such as phenol, cresol, and ethylphenol; alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol; active methylene compounds such as methyl isobutyl acetate, dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, and acetylacetone; thiol compounds such as butanethiol and dodecyl mercaptan; lactamic compounds such as ε-caprolactam and δ-pentanolide; amine compounds such as diphenylaniline, aniline, and ethyleneimine; acetamide compounds such as acetaniline and acetylamine; and oxime compounds such as formaldehyde oxime, acetaldehyde oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime. These can be used alone or in combination of two or more. ≪Silane Coupling Compounds≫ Silane coupling compounds refer to organosilicon compounds that contain an organic functional group and a hydrolyzable group such as an alkoxy group in a single molecule. Examples include: 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc., containing epoxy groups; vinyltrimethoxysilane, vinyltriethoxysilane, etc., containing vinyl groups; p-styrenetrimethoxysilane, etc. styrene-containing compounds such as methoxysilane and p-styrenetriethoxysilane; (meth)propenylpropyltrimethoxysilane, 3-(meth)propenylpropyltriethoxysilane, 3-(meth)propenylpropylmethyldimethoxysilane, 3-(meth)propenylpropylmethyldiethoxysilane, etc., containing (meth)propenyl groups; 3-aminopropyltrimethoxysilane, 3-aminopropyl... Triethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, N-phenyl-3 -Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane and other amino-containing compounds; tris(trimethoxysilylpropyl) isocyanurate, tris(triethoxysilylpropyl) isocyanurate and other isocyanuric acid-containing compounds; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane and other mercapto-containing compounds. The content of compound (b) in this composition, based on its proportion to all non-volatile components in the composition, is preferably in the range of 10-60% by mass, more preferably 20-50% by mass. By setting this content to 10% by mass or more, the coating strength is improved. Furthermore, by setting this content to 60% by mass or less, the influence on the release layer disposed on this resin layer (e.g., curing inhibition) can be suppressed. (Antistatic Agent) An antistatic agent may be used in this resin layer. By using an antistatic agent, foreign matter adhering to the film surface due to static electricity can be suppressed during the manufacturing or processing process. The antistatic agent used in this resin layer is preferably an ionicly conductive antistatic agent, and more preferably a compound containing a quaternary ammonium group. A compound containing a quaternary ammonium group refers to a compound having a quaternized ammonium group within its molecule, particularly a polymer, and even more preferably a water-soluble compound. In the second laminated polyester film, for example, a polymer containing monomers having quaternary ammonium groups can be used. As a specific example of such a polymer, one could cite a polymer having the constituent elements represented by the following chemical formula (P) or the following chemical formula (Q) as repeating units. These could be homopolymers or copolymers, or further copolymers of other multiple components. [Chemistry 1] In the above chemical formula (P), R 1 R 2 Each is independently a hydrogen atom, alkyl group, phenyl group, etc., and these alkyl and phenyl groups can be substituted with the following groups. Examples of substituents include hydroxyl, amide, ester, alkoxy, phenoxy, naphthoxy, thioalkoxy, thiophenoxy, cycloalkyl, trialkylammonium alkyl, cyano, and halogen. Also, R 1 and R 2 They can also be chemically bonded, for example: -(CH 2) m -(m = integers from 2 to 5), -CH(CH) 3)CH(CH 3)-, -CH=CH-CH=CH-, -CH=CH-CH=N-, -CH=CH-N=C-, -CH 2OCH 2-、-(CH 2) 2O(CH 2) 2- etc. [Chemistry 2] In the above chemical formula (Q), R 2 For -O- or -NH-, R 3 R is an alkyl group or other structure that enables the structure of chemical formula (Q) to be valid. 1 R 4 R 5 R 6 These are hydrogen atoms, alkyl groups, phenyl groups, etc., which may be substituted with the following groups. Examples of substituents include hydroxyl, amide, ester, alkoxy, phenoxy, naphthoxy, thioalkoxy, thiophenoxy, cycloalkyl, trialkylammonium alkyl, cyano, and halogen. X in the above chemical formulas (P) and (Q) - Appropriate options can be selected within the scope of ensuring no damage to the second-layer polyester film. Examples include: halide ions, sulfonates, phosphates, nitrates, alkyl sulfonates, carboxylates, etc. When the resin layer contains an antistatic agent, the content of the antistatic agent in the composition, based on its proportion to all non-volatile components in the composition, is preferably in the range of 20-60% by mass, more preferably 30-50% by mass. By setting this content to 20% by mass or more, the adhesion of foreign matter to the film surface due to static electricity is suppressed during the manufacturing or processing process, thus achieving antistatic properties. Furthermore, by setting this content to 60% by mass or less, the influence on the release layer disposed on the resin layer (e.g., inhibition of curing) can be suppressed. (Other components) In addition to the above components, crosslinking catalysts, defoamers, coatability modifiers, surfactants, tackifiers, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments and other additives may be appropriately formulated within the scope of not damaging the second laminated polyester film. (Solvent) This composition can also be diluted with a solvent to prepare a coating liquid. That is, this composition can be used as a liquid coating liquid, for example, coated onto a second polyester film, dried and hardened as needed to form a resin layer. Furthermore, the components constituting this composition (compounds (a) and (b), antistatic agent, other components, etc.) can be dissolved in a solvent or dispersed in a solvent. When preparing a coating liquid, the concentration of all non-volatile components of this composition in the coating liquid is preferably 0.1 to 50% by mass. If it is 0.1% by mass or more, a resin layer of the desired thickness can be formed efficiently. On the other hand, if it is 50% by mass or less, the appearance of the resin layer can be improved by suppressing the viscosity during coating, and the stability of the coating liquid can be improved. There are no particular restrictions on the solvents used; either water or organic solvents can be used. From an environmental protection perspective, it is preferable to use water as the main solvent (50% by mass or more of the total solvent) to prepare the aqueous coating solution. The water content is preferably 60% by mass or more, more preferably 70% by mass or more. The aqueous coating solution may contain a small amount of organic solvent. The specific amount of organic solvent is based on mass and can be set below the amount of water, for example, it can be set below 50% by mass of the solvent, preferably below 40% by mass, and more preferably below 30% by mass. Examples of organic solvents that can be used with water include: alcohols such as ethanol, isopropanol, ethylene glycol, and glycerol; ethers such as ethyl cellosolve, tributyl cellosolve, propylene glycol monomethyl ether, and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and amines such as dimethylethanolamine. These can be used alone or in combination. By appropriately selecting and including these organic solvents in the aqueous coating solution as needed, the stability and coating properties of the coating solution can sometimes be improved. Furthermore, when only an organic solvent is used as the solvent mentioned above, examples of such organic solvents include: aromatic hydrocarbons such as toluene; aliphatic hydrocarbons such as hexane, heptane, and isooctane; esters such as ethyl acetate and butyl acetate; ketones such as ethyl methyl ketone and isobutyl methyl ketone; alcohols such as ethanol and 2-propanol; and ethers such as diisopropyl ether and dibutyl ether. These solvents can be used individually or in combination, taking into account factors such as solubility, coatability, and boiling point. It can be inferred that the resin layer contains unreacted substances, reacted compounds, or mixtures thereof of the components constituting this composition (compounds (a) and (b), antistatic agents, other components, etc.). Furthermore, the analysis of the components in the resin layer can be performed, for example, by TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry), ESCA (Electron Spectroscopy for Chemical Analysis), fluorescence X-rays, etc. (Method for Forming the Resin Layer) Next, the method for forming the resin layer constituting the second laminated polyester film will be described. Regarding this resin layer, it can be formed simply by coating the composition onto the polyester film and then subjecting the coated composition to drying, curing, heat treatment, or other treatments as needed. There are no particular limitations on the method of coating the resin composition; for example, previously known coating methods such as reverse gravure coating, direct gravure coating, roller coating, die coating, rod coating, and curtain coating can be used. Furthermore, as methods for forming the resin layer, there are in-line coating and offline coating. There is no particular limitation on the method of heat treatment of the coated resin composition. For example, when the resin layer is formed by offline coating, heat treatment is generally performed according to the following standard: at 80–200°C for 3–40 seconds, preferably at 100–180°C for 3–40 seconds. On the other hand, when the resin layer is formed by in-line coating, heat treatment is generally performed according to the following standard: at 70–280°C for 3–200 seconds. Furthermore, heat treatment can also be performed in two or more stages at different temperatures within the above temperature range. At least a portion of the heat treatment can be performed by heating during stretching. Furthermore, drying and hardening can be performed uniformly by heating during the above heat treatment. In the second laminated polyester film, the resin layer is preferably formed by in-line coating, which involves treating the film surface during the polyester film manufacturing process. In-line coating is a coating method performed during the polyester film manufacturing process. Specifically, it refers to a method of coating at any stage after the polyester has been melt-extruded, stretched, and then heat-cured and rolled up. It is typically applied to any of the following: unstretched sheets obtained by melting and quenching; stretched uniaxially stretched films; biaxially stretched films before heat curing; and films after heat curing but before rolling up. For example, in successive biaxial stretching, a particularly advantageous method is to stretch laterally after coating a uniaxially stretched film that has already stretched along its long side (longitudinal direction), but it is not limited to the above. According to this method, film formation and resin layer formation can be performed simultaneously, thus offering advantages in manufacturing costs. Furthermore, since stretching is performed after coating, the thickness of the resin layer can also be varied according to the stretch ratio, making thin film coating easier compared to offline coating. Furthermore, by setting a resin layer on the film before stretching, the resin layer and the polyester film can be stretched together, thereby making the resin layer firmly bonded to the polyester film. Furthermore, in the manufacture of biaxially stretched polyester films, the film ends are held in place by clamps while the film is stretched, thereby restricting the film in both the longitudinal and transverse directions. During subsequent heat treatment (heat-setting process), high temperatures can be applied while maintaining planarity without wrinkles. Therefore, the heat treatment performed after coating can achieve high temperatures that are unattainable by other methods, thus improving the film-forming properties of the resin layer and allowing for a more robust bond between the resin layer and the polyester film. This results in a strong resin layer, improving properties such as resistance to transfer or damp heat that can be formed on the resin layer. Furthermore, regardless of whether offline coating or in-line coating is used, heat treatment and active energy line irradiation such as ultraviolet irradiation can be combined as needed. For the polyester film constituting this laminated polyester film, surface treatments such as corona treatment and plasma treatment can also be performed in advance. The thickness of this resin layer is preferably 0.005 to 1 μm, more preferably 0.01 to 0.5 μm, and even more preferably 0.01 to 0.1 μm. If the thickness is within this range, the influence on the release layer formed on the resin layer (such as curing inhibition) can be suppressed, and the adhesion to the release layer can be improved. <Release Layer> The second laminated polyester film can be used in a form having a release layer on at least one side. This release layer is preferably laminated on a resin layer. That is, the second laminated polyester film preferably has a release layer on the resin layer. Specifically, the second laminated polyester film preferably has a resin layer and a release layer sequentially on one surface (A) of the polyester film. Therefore, when the second polyester film is, for example, composed of A / B / C, and surface (A) corresponds to surface layer A, a resin layer and a release layer are sequentially laminated on the surface of surface layer A, forming a release layer / resin layer / A / B / C configuration. By laminating a release layer on the resin layer side formed on one surface (A) of the polyester film, an ultra-thin ceramic layer is laminated on the release layer, making it less prone to pinholes during ceramic sheet forming, which is preferable. As described above, the release layer is deposited on the polyester film via a resin layer. The release layer described above is formed from a release agent composition containing a release agent, and from the viewpoint of obtaining good release properties, it is particularly preferable that the release agent composition contains a silicone resin. Specifically, the example exemplified in the first polyester film described above can be used as well. The release layer is more preferably composed of a curable silicone resin. As the aforementioned cured silicone resin, the cured silicone resin exemplified in the first polyester film can also be cited as an example. The release agent composition that forms the release layer may also contain, as needed, adhesives, defoamers, coatability modifiers, tackifiers, inorganic or organic particles, organic lubricants, antistatic agents, conductive agents, ultraviolet absorbers, antioxidants, foaming agents, dyes, and pigments. The release layer is formed by coating a release agent composition onto a second laminated polyester film, which can be either inline coating performed during the film-making process or so-called offline coating applied to a temporarily manufactured film outside the system. As a method for providing a release layer on the second laminated polyester film, the method for providing a release layer described in the first polyester film can be similarly exemplified. There are no particular limitations on the hardening conditions for forming the release layer. When the release layer is set by offline coating, the heat treatment can usually be carried out according to the following standards: at or above 80°C for more than 10 seconds, preferably at 100-200°C for 3-40 seconds, and even more preferably at 120-180°C for 3-40 seconds. Furthermore, heat treatment and active energy line irradiation such as ultraviolet radiation can be combined as needed. Moreover, known devices and energy sources can be used as the energy source for hardening by active energy line irradiation. In terms of coatability, the coating weight (after drying) of the release layer is typically between 0.005 and 5 g / m². 2The preferred value is 0.005–1 g / m³. 2 The preferred concentration is 0.005–0.1 g / m³. 2 Within this range. The coating amount (after drying) did not reach 0.005 g / m². 2 In such cases, stability is lacking in terms of coatability, and it is sometimes difficult to obtain a uniform coating. On the other hand, at concentrations exceeding 5 g / m²... 2 When applying a thick coating, the adhesion and hardening properties of the release layer itself may be reduced. Furthermore, the coating amount is calculated based on the liquid mass per unit coating time (before drying), the concentration of non-volatile components in the coating liquid, the coating width, the elongation ratio, and the linear velocity. (Applications) The first polyester film and the second laminated polyester film are suitable for various release applications. For example, they can be used as dry film resist (DFR), for multilayer circuit boards, and for the manufacture of ceramic blanks for multilayer ceramic capacitors, among other release and process applications. In release and process applications, this film can be used as a support, for example, to coat or laminate various materials such as ceramic slurry onto the support. In particular, the first polyester film, as mentioned above, possesses specific smoothness, which, on the other hand, can improve productivity. Therefore, it is suitable as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors. Furthermore, as mentioned above, the second multilayer polyester film has excellent smoothness, which can handle the thin-film forming of ceramic blanks. Therefore, it is suitable as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors. Furthermore, regarding multilayer ceramic capacitors suitable for increasingly electrified automobiles, it is anticipated that the miniaturization and high capacitance of these capacitors will lead to continuous development in the thin-film technology of the ceramic blanks used. Therefore, the first polyester film and the second multilayer polyester film are suitable as supports for the ceramic blanks used in multilayer ceramic capacitors suitable for automobiles. [Example] The present invention will be described in more detail below with reference to embodiments and comparative examples, but the present invention is not limited to the following embodiments. [Example of the first polyester film] <Manufacturing of polyester> (1) Manufacturing of polyester 1-A 100 parts by mass of dimethyl terephthalate and 65 parts by mass of ethylene glycol are added to an ester exchange reaction tank equipped with a stirring device, a heating device and a distillation separation tower, and heated to 150°C to melt the dimethyl terephthalate. Subsequently, an ethylene glycol solution of magnesium acetate tetrahydrate was added, with the amount of magnesium acetate added being 0.09% by mass relative to the obtained polyester. Then, the temperature was raised to 225°C under normal pressure for 3 hours, and then stirred and maintained at 225°C for 1 hour and 15 minutes. At the same time, methanol was removed by distillation while the transesterification reaction was carried out, and the transesterification reaction was substantially completed to obtain the polyester oligomer (oligomer). The oligomers were then transferred to a polycondensation reactor equipped with a distillation tube and a stirrer. An ethylene glycol solution of magnesium acetate tetrahydrate was added to the transferred oligomers at a magnesium acetate content of 0.09% by mass relative to the obtained polyester resin composition. Then, an ethylene glycol solution of phosphoric acid was added as a heat stabilizer at a phosphoric acid content of 0.017% by mass relative to the obtained polyester. Subsequently, a tetrabutyl titanate solution in ethylene glycol was added to the oligomer as a polycondensation catalyst at a concentration of 4.5 ppm by mass relative to the obtained polyester (based on titanium atoms). Then, a melt polycondensation reaction was carried out by reducing the pressure from 101.3 kPa to 0.4 kPa over 85 minutes and maintaining it at 0.4 kPa, while simultaneously increasing the temperature from 225°C to 280°C over 2 hours and maintaining it at 280°C for 1.5 hours, thereby obtaining polyester 1-A with an ultimate viscosity (IV) of 0.63 dL / g. (2) The polyester 1-B is manufactured by solid-state polymerization of the above-mentioned polyester 1-A to obtain polyester 1-B with an ultimate viscosity (IV) of 0.70 dL / g. (3) Polyester 1-C is manufactured in the above-mentioned polyester 1-A by adding antimony trioxide as a polycondensation catalyst in a manner that is 300 ppm by mass relative to the obtained polyester resin composition, in place of tetrabutyl titanate. Otherwise, the process is the same as that of polyester 1-A, and polyester 1-C with an ultimate viscosity (IV) of 0.63 dL / g is obtained. (4) Polyester 1-D is produced by adding tetrabutyl titanate to the above-mentioned polyester 1-A in such a way that the amount of titanium atoms is 210 ppm by mass relative to the obtained polyester. Otherwise, the process is the same as that of polyester 1-A to obtain polyester 1-D with an limiting viscosity (IV) of 0.63 dL / g. (5) Manufacturing of Polyester 1-E: 1.0% by mass of monodisperse spherical silica with an average primary particle size of 0.5 μm ((D90-D10) / D50=0.27) is added to the above-mentioned polyester 1-D, and the mixture is kneaded using an exhaust-type twin-shaft mixer to obtain polyester 1-E. (6) Manufacturing of Polyester 1-F: 0.75% by mass of alumina particles with an average primary particle size of 0.05 μm are added to the above-mentioned polyester 1-D, and the mixture is kneaded using an exhaust-type biaxial mixer to obtain polyester 1-F. (8) Manufacturing of Polyester 1-G: 1.0% by mass of organic particles with an average primary particle size of 0.3 μm ((D90-D10) / D50 = 0.46: divinyl styrene-ethyl styrene-methacrylic acid-styrene copolymer) are added to the above-mentioned polyester 1-D, and the mixture is kneaded using an exhaust-type biaxial mixer to obtain polyester 1-G. (9) Manufacturing of Polyester 1-H: Add 10% by mass of a fatty acid metal salt crystallizing nucleating agent (manufactured by Clariant: Licomont NaV101 (CH)) to the above-mentioned polyester 1-D. 3(CH 2) 26 Polyester 1-H is obtained by mixing COONa (melting point 171℃) using an exhaust-type twin-shaft mixer. (10) Manufacturing of Polyester 1-I: 5% by mass of a crystallizing nucleating agent (manufactured by ADEKA: NA-27, phosphate metal salt, melting point 230°C) is added to the above-mentioned polyester 1-D, and the mixture is kneaded using an exhaust-type twin-shaft mixer to obtain polyester 1-I. Furthermore, the limiting viscosity (IV) and the average particle size and particle size distribution mentioned above were determined by the methods described in (1) Limiting viscosity (IV) and (2) Average particle size and particle size distribution in the <Methods for Measurement and Evaluation>. [Example 1-1] A raw material obtained by blending polyester 1-D at a mass ratio of 90% and polyester 1-H at 10% was used as the raw material for surface layer A. A raw material obtained by blending polyester 1-C at a mass ratio of 100% was used as the raw material for intermediate layer B. A raw material obtained by blending polyester 1-D at a mass ratio of 70% and polyester 1-G at 30% was used as the raw material for surface layer C. These materials were fed into an extruder equipped with venting holes and melt-extruded at 290°C. The resulting three-layer structure (A / B / C) consisted of surface layer A and C as the outermost layer (surface layer) and intermediate layer B as the intermediate layer. Co-extrusion was performed under extrusion conditions with a thickness ratio of A / B / C = 1.5 / 28 / 1.5. An amorphous film was obtained by cooling and curing on a cooling roller with a surface temperature set to 40°C using an electrostatic bonding method. In this case, surface layer C is the side in contact with the cooling roller. Subsequently, utilizing the difference in roller speed, the film is extended 3.4 times in the longitudinal direction (MD) at a film temperature of 85°C. The longitudinally extended film is then fed into a tenter frame and extended 4.6 times in the transverse direction (TD) at 120°C. The film is then heat-treated in the heat treatment (fixing) zones 1 and 2, and the cooling zones 3 and 4 within the tenter frame at 215°C, 205°C, 150°C, and 110°C, respectively. Finally, the film is wound into a 6-inch plastic core in a roll shape to obtain a polyester film with a thickness of 31 μm. [Examples 1-2] In Example 1-1, the raw material mixing ratio of surface layer A and the thickness of each layer were changed as shown in Table 1. Otherwise, the polyester film was manufactured in the same manner as in Example 1-1. [Comparative Examples 1-1] to [Comparative Examples 1-3] In Example 1-1, the raw material mixing ratios of surface layer A and surface layer C and the thickness of each layer were changed as shown in Table 1. Otherwise, polyester films were manufactured in the same manner as in Example 1-1. The characteristics of each film obtained are shown in Table 1 below. <Measurement and Evaluation Methods> The measurement and evaluation methods used in the examples and comparative examples are described below. The results of the measurement and evaluation are summarized in Table 1. (1) Limiting viscosity (IV) Accurately weigh 1 g of polyester, add 100 mL of a mixed solvent of phenol / tetrachloroethane = 50 / 50 (mass ratio) to dissolve it, and use a viscosity (IV) measuring device (VMS-022UPC・F10 manufactured by Lihe Company) to measure it at 30°C. (2) The average particle size and particle size distribution were determined using a scanning electron microscope (HITACHI, "S3400N") to observe the powder on the surface of the polyester film of the examples and comparative examples from the surface layer A side. The size of one particle was measured from the obtained image data, and the average value of 10 points was taken as the average first particle size. In addition, a dispersion with a solid content of 0.03 g / mL was prepared by adding a phenol / tetrachloroethane mixed solvent of 2 / 3 to the raw material particles. For this dispersion, the particle size D10, the particle size D50, and the particle size D90 that reached 10% of the total number of particles were measured by laser diffraction using a MicrotracBEL "MT3300EXII". The particle size distribution was calculated as (D90-D10) / D50. (3) Thermal Analysis of the Nucleating Agent (TG-DTA) A DSC (manufactured by Hitachi High-Tech Science Co., Ltd., model: STA200RV AS) was used to heat the agent from room temperature to 290°C at a rate of 120°C / min, and then maintain the temperature at 290°C for 10 minutes. During this process, the state change of the nucleating agent was confirmed, and the state change of the nucleating agent at the time point of reaching 200°C was observed. (Judgment Criteria) A: Confirmed as melted at 200°C. B: Confirmed as unmelted at 200°C. (4) Average surface roughness (Sa), maximum peak height (Sp), and root mean square slope (Sdq) Using a surface roughness measuring instrument (manufactured by AMETEK Co., Ltd., "NewView" (registered trademark)), the surface profile curve of the surface layer A of the polyester film of the examples and comparative examples was measured, and the average surface roughness (Sa), maximum peak height (Sp), and root mean square slope (Sdq) were obtained from the obtained surface profile curve. (5) The number of protrusions was determined using a white light interferometer (manufactured by Bruker, "Contour"). The number of protrusions with a height of less than 50 nm was measured on the surface of the polyester film of the examples and comparative examples under the following measurement conditions (unit: protrusions / mm). 2 The number of protrusions with a height of 50 nm or more but less than 100 nm (unit: protrusions / mm) 2 ), and the number of protrusions with a height of 100 nm or more (unit: protrusions / mm) 2 (Measurement conditions) • Measurement mode: VXI mode • Objective lens: 20x • Internal lens: 0.55x • Field of view area: 586 μm × 460 μm (6) Damage Resistance Regarding scratches and defects on the membrane surface, A4-sized sample films of the polyester films from the examples and comparative examples were prepared. The presence of scratches (micro-scratches, scratch-like defects, granular patterns, etc.) was confirmed under both "transmitted light under three-wavelength fluorescent lamps in an indoor environment" and "reflected light from a halogen lamp in a dark room." The number of scratches detected was counted, and the following evaluation criteria were used for judgment. <Evaluation Criteria> A: 0 to 4 scratches with a depth of 0.3 μm or more that can be confirmed under transmitted light under three-wavelength fluorescent lamps in an indoor environment or under reflected light from a halogen lamp. B: 5 or more scratches with a depth of 0.3 μm or more that can be confirmed under transmitted light under three-wavelength fluorescent lamps in an indoor environment or under reflected light from a halogen lamp. (7) Thin film formation of ceramic blanks: In the polyester films of the examples and comparative examples, the number of protrusions with a diameter of 100 nm or more should be 1 per mm. 2 Below, a condition where the maximum peak height (Sp) of surface layer A is below 60 nm is considered good "A", and a condition where the number of protrusions above 100 nm exceeds 1 per mm is considered good. 2 The situation, or the situation where the maximum peak height (Sp) exceeds 60 nm, is judged as undesirable "B". For example, in the forming process of thin film ceramic blanks with a thickness of less than 0.5 μm, the risk of pinholes and other defects increases due to the higher protrusions present when the maximum peak height (Sp) exceeds 60 nm. (8) When the polyester film roll is wound into a roll shape for 12,000 m, the situation in which no wrinkles are generated and the roll can be made into a roll is judged as good "A", and the situation in which wrinkles are generated and the roll cannot be made into a roll is judged as bad "B". [Table 1] In the surface layer A of Examples 1-1 and 1-2, the number (Y) of protrusions larger than 100 nm is 1 per mm. 2 The number of protrusions (X) less than 50 nm is 2000 per mm. 2 Furthermore, the maximum peak height (Sp) is below 60 nm. Therefore, Examples 1-1 and 1-2 are excellent in terms of damage resistance, thin-film processing of preforms, and strip processing of polyester films. On the other hand, comparing the number of protrusions in Examples 1-1 and 1-2 with Comparative Example 1-3 (particle system), it was confirmed that in both the number of protrusions above 50 nm and below 100 nm (Z) and the number of protrusions above 100 nm (Y), Comparative Example 1-3, which added alumina particles to surface layer A, was overwhelmingly greater. Moreover, comparing the number of protrusions in Examples 1-1 and 1-2 with Comparative Example 1-2, it was confirmed that Comparative Example 1-2 had a higher maximum peak height (Sp) even with a smaller amount of nucleating agent added, presumably due to the aggregation of the nucleating agent. Furthermore, the nucleating agent used in Comparative Examples 1-2 was not sufficiently compatible with the polyester resin and agglomerated within the polyester film, thus being considered a negative factor in ensuring a specific smoothness. Comparative Example 1-1 was an example of a particle-free surface without the addition of a nucleating agent to the surface layer A, but it was too smooth, easily causing wrinkles, and difficult to handle elongated shapes when made into rolls. [Examples of Second-Layer Polyester Films] <Polyester Raw Materials> The polyester raw materials used in the examples and comparative examples are shown in Table 2-1. Polyester raw materials 2-A to 2-D listed in Table 2-1 are all homopolymer polyethylene terephthalate (isopolymer polyester). Furthermore, in the manufacture of polyester raw material 2-C, as a crystallization nucleating agent, 10% by mass of a fatty acid metal salt crystallization nucleating agent (manufactured by Clariant: Licomont NaV101 (CH)) was added relative to the polyester. 3(CH 2) 26 COONa), melting point 171℃). Also, in the manufacture of polyester raw material 2-D, 1.0% by mass of monodisperse spherical silica with an average primary particle size of 0.5 μm ((D90-D10) / D50=0.27) is added relative to the polyester. [Table 2-1] [Example 2-1] A raw material obtained by blending polyester raw material 2-A at a mass ratio of 90% and polyester raw material 2-C at a mass ratio of 10% was used as the raw material for surface layer A. A raw material obtained by blending polyester raw material 2-B at a mass ratio of 100% was used as the raw material for intermediate layer B. A raw material obtained by blending polyester raw material 2-A at a mass ratio of 70% and polyester raw material 2-D at a mass ratio of 30% was used as the raw material for surface layer C. These materials were fed into an extruder equipped with venting holes and melt-extruded at 290°C. The resulting three-layer structure consisted of three layers (A / B / C): the raw materials for surface layers A and C were formed into the outermost layer (surface layer), and the raw material for intermediate layer B was formed into the intermediate layer. Co-extrusion was performed under extrusion conditions with a thickness composition ratio of A / B / C = 3 / 27 / 1. An amorphous film was obtained by cooling and curing on a cooling roller with a surface temperature set at 40°C using an electrostatic bonding method. In this case, surface layer C is the side in contact with the cooling roller. Subsequently, using the roller speed difference, after extending 3.5 times in the longitudinal direction (MD direction) at a film temperature of 85°C, a coating liquid having the following composition is applied to one side of the longitudinally extended film to a thickness (after drying) of 0.02 μm. The film is then introduced into a tenter frame and extended 4.5 times in the transverse direction (TD direction) at 105°C. Heat treatment is then performed in the heat treatment (fixing) zones 1, 2, 3 and cooling zone 4 of the tenter frame at 170°C, 230°C, 230°C and 140°C, respectively, to obtain a laminated polyester film with a resin layer R1 on the surface layer A of a polyester film with a thickness of 31 μm. The coating liquid in Example 2-1 was prepared by diluting a resin composition obtained by stirring and mixing according to the following composition with water. (Compound (a) Adhesive resin) Polyvinyl alcohol resin: 20% by mass of polyvinyl alcohol with a saponification degree of 88 mol% and a polymerization degree of 500 (Compound (b) Crosslinking agent) Melamine compound: 40% by mass of hexamethoxyhydroxymethyl melamine (Antistatic agent) Poly(trimethylammonium ethyl methacrylate-methanesulfonate) 40% by mass Furthermore, the content ratios of the above compounds are the proportions of all non-volatile components in this composition. [Example 2-2] Except for the change of coating liquid as described below in Example 2-1, a laminated polyester film with a resin layer R2 on the surface layer A of a polyester film with a thickness of 31 μm was obtained by manufacturing in the same manner as in Example 2-1. The coating liquid in Example 2-2 was prepared by diluting a resin composition obtained by stirring and mixing according to the following composition with water. (Compound (a) Adhesive Resin) Polyester Resin: 60% by mass of an aqueous dispersion of polyester resin obtained by copolymerization according to the following composition Monomer composition: (Acid component) 2,6-naphthalenedicarboxylic acid / 5-sodium sulfoisophthalic acid / / (Diol component) ethylene glycol / diethylene glycol = 92 / 8 / / 80 / 20 (mol%) (Compound (b) Crosslinking Agent) Melamine compound: 10% by mass of hexamethoxyhydroxymethyl melamine Epoxy compound: 30% by mass of polyglycerol polyglycidyl ether Furthermore, the above compounds are contained in proportions of all non-volatile components in the composition. [Comparative Example 2-1] In Example 2-1, the coating liquid was changed to a coating liquid that does not contain the adhesive resin of compound (a) as shown below. Otherwise, it was manufactured in the same manner as in Example 2-1, and a laminated polyester film having a resin layer R3 on the surface layer A of a polyester film with a thickness of 31 μm was obtained. The coating liquid in Comparative Example 2-1 was prepared by diluting a resin composition obtained by stirring and mixing according to the composition shown below with water. (Compound (b) Crosslinking agent) Melamine compound: hexamethoxyhydroxymethyl melamine 60% by mass Azoline compound: Epocros (manufactured by Nippon Shokubai Co., Ltd.) Azoline group 7.7 mmol / g 40% by mass Furthermore, the content ratios of the above compounds are the percentages of all non-volatile components in this composition. [Comparative Example 2-2] Except that no resin layer was provided in Example 2-1, a polyester film with a thickness of 31 μm was obtained by manufacturing in the same manner as in Example 2-1. [Comparative Examples 2-3] In Example 2-1, the raw material mixing ratio of surface layer A was changed as shown in Table 2-2, and no resin layer was provided. Otherwise, it was manufactured in the same manner as in Example 2-1 to obtain a polyester film with a thickness of 31 μm. <Measurement and Evaluation Methods> The measurement and evaluation methods used in the examples and comparative examples are described below. (1) Limiting viscosity (IV) Accurately weigh 1 g of polyester, add 100 mL of a mixed solvent of phenol / tetrachloroethane = 50 / 50 (mass ratio) to dissolve it, and use a viscosity (IV) measuring device (“VMS-022UPC・F10” manufactured by Lihe Company) to measure it at 30°C. (2) The average particle size and particle size distribution were determined using a scanning electron microscope (HITACHI, "S3400N") to observe the powder on the surface of the films of the examples and comparative examples. The size of one particle was measured from the obtained image data, and the average of 10 points was taken as the average first particle size. In addition, a dispersion with a solid content of 0.03 g / mL was prepared by adding a phenol / tetrachloroethane mixed solvent of 2 / 3 to the particles. For this dispersion, the particle size D10, the particle size D50, and the particle size D90 reaching the cumulative number of particles were measured by laser diffraction scattering method using a MicrotracBEL "MT3300EXII". The particle size distribution was calculated as (D90-D10) / D50. (3) Average surface roughness (Sa) and maximum peak height (Sp): Using a surface roughness measuring instrument (manufactured by AMETEK Co., Ltd., "NewView" (registered trademark)), the surface profile curves of the resin layer (surface layer A when there is no resin layer) and surface layer C of the films of the examples and comparative examples were measured, and the average surface roughness (Sa) and maximum peak height (Sp) were obtained from the obtained surface profile curves. The results are shown in Table 2-2. (4) Adhesion of the release layer coating: On the resin layer (surface layer A when there is no resin layer) of the films in the examples and comparative examples, the following release layer composition was applied at a coating amount (after drying) of 0.1 g / m. 2The coating was applied in the manner described above, and after heat treatment at 150°C for 30 seconds, a film with a release layer (release film) was obtained. The release layer of the obtained release film was rubbed five times by hand, and the presence or absence of release layer peeling was determined according to the following criteria. Furthermore, the sample film was stored at 23°C and 50±3%RH for the period specified in Table 2-2, and the change in the adhesion of the release layer coating (whether the release layer peeled off) over time was confirmed using the same method. The results are shown in Table 2-2. (Release layer composition) Curing silicone resin (Shin-Etsu Chemical Manufacturing: KS-847H) 99% by mass Curing agent (Shin-Etsu Chemical Manufacturing: PL-50T) 1% by mass The above release agent was adjusted to 2% by mass using a toluene / MEK mixed solvent (mixing ratio of 1:1). Judgment Criteria: ○: No coating peeling found, or the coating has turned white but has not peeled off (practical level) ×: Coating peeling confirmed (unpractical level) [Table 2-2] As shown in Table 2-2, the films of Examples 2-1 and 2-2 have an average surface roughness (Sa) of 1–10 nm, exhibiting specific smoothness. Furthermore, a nucleating agent can be used to control the maximum peak height (Sp) while maintaining the average surface roughness (Sa). Additionally, the films of Examples 2-1 and 2-2 have a specific resin layer, thus exhibiting no inhibition of release layer hardening, and consequently, good adhesion to the release layer. On the other hand, the film system of Comparative Examples 2-3, where surface layer A does not contain a nucleating agent and the film does not have a resin layer, is too smooth, resulting in reduced slipability and potentially impairing processability. Furthermore, it is impossible to reduce the maximum peak height (Sp) relative to the average surface roughness (Sa), making it difficult to balance smoothness and processability. In addition, it is observed that the adhesion of the release layer deteriorates over time. Moreover, when the release layer is directly applied to surface layer A containing a nucleating agent, as in Comparative Example 2-2, or when the release layer is applied to a resin layer without (a) adhesive resin, as in Comparative Example 2-1, the adhesion deteriorates immediately after the release layer is applied. Therefore, it is understood that the nucleating agent component inhibits the hardening of the release layer. [Industrial Applicability] The first polyester film possesses specific smoothness and, with increased productivity, can handle the elongation of polyester films. Furthermore, when used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors, a uniform thin-film dielectric layer can be formed. It is particularly suitable as a support for ceramic blanks used in multilayer ceramic capacitors for automobiles. The second multilayer polyester film also possesses specific smoothness and offers the advantage of improved adhesion to the release layer. Furthermore, when used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors, a uniform thin-film dielectric layer can be formed. It is particularly suitable as a support for ceramic blanks used in multilayer ceramic capacitors for automobiles. Figure 1 illustrates the thermodynamic crystallization mechanism (estimated) of polyester resin with and without a nucleating agent. Figure 2 illustrates the effect of the casting drum during polyester film manufacturing and the formation mechanism of surface unevenness caused by the use of a nucleating agent (estimated). Figure 3 shows the distribution of the nucleating agent on one surface (A) of the polyester film obtained in Examples 1-1. Figure 4 shows the particle-free surface state of one surface (A) of the polyester film obtained in Comparative Examples 1-1. Figure 5 shows the distribution of the nucleating agent on one surface (A) of the polyester film obtained in Comparative Examples 1-2. Figure 6 shows the distribution of the particulate compound on one surface (A) of the polyester film obtained in Comparative Examples 1-3.

Claims

1. A polyester film, wherein one surface (A) of the polyester film satisfies the following (11) to (13), wherein the surface (A) of the polyester film contains a nucleating agent, and the nucleating agent is a fatty acid metal salt represented by the following general formula (X), (11) the number of protrusions (Y) of 100 nm or more is 1 or less / mm2; (12) the number of protrusions (X) of less than 50 nm is 2000 or more / mm2; (13) the maximum peak height (Sp) is 60 nm or less; (CH3(CH2)nCOO)mM (X) (in the above general formula (X), n is an integer of 4 or more, M is Na, Ca or Li, and m is 1 when M is Na or Li, and 2 when M is Ca).

2. The polyester film of claim 1, wherein on one surface (A) of the polyester film, the number (Z) of protrusions 50 nm or larger and less than 100 nm is less than 100 protrusions / mm2.

3. The polyester film of claim 1, wherein the melting point of the aforementioned fatty acid metal salt is above 140°C and below 220°C.

4. The polyester film of claim 1, wherein one surface (A) of the polyester film contains fatty acid ions.

5. The polyester film of claim 1, wherein one surface (A) of the polyester film contains metal ions.

6. The polyester film of claim 1, wherein one surface (A) of the polyester film contains fatty acid ions and metal ions.

7. The polyester film of claim 1, wherein one surface (A) of the polyester film satisfies the following (14) and (15): (14) the average surface roughness (Sa) is 1 to 20 nm; (15) the root mean square slope (Sdq) is 0.2 to 1.

1.

8. The polyester film of claim 1, wherein the polyester film is composed of 3 layers.

9. The polyester film of claim 8, wherein the polyester film has an intermediate layer containing 50% by mass or more of recycled polyester raw material.

10. The polyester film of claim 8, having a surface layer C on the side opposite to one of the surfaces (A) of the polyester film.

11. The polyester film of claim 10, wherein the surface layer C comprises particles.

12. The polyester film of claim 11, wherein the average particle size of the aforementioned particles is 0.1 to 1.5 μm.

13. The polyester film of claim 1, having a release layer on one surface (A) of the polyester film.

14. The polyester film of any one of claims 1 to 13 is used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors.

15. The polyester film of any one of claims 1 to 13 is used as a support for ceramic blanks in the manufacturing process of automotive ceramic capacitors.

16. A laminated polyester film, wherein one surface (A) of the polyester film contains a nucleating agent, and a resin layer formed of a resin composition comprising (a) an adhesive resin and (b) a crosslinking agent is provided on the surface (A), wherein the surface of the resin layer satisfies the following (21) and (22), and the nucleating agent is a fatty acid metal salt represented by the following general formula (X), (21) the average surface roughness (Sa) is 1 to 10 nm; (22) the maximum peak height (Sp) is 150 nm or less; (CH3(CH2)nCOO)mM・・・(X) (in the above formula, n is an integer of 4 or more, M is Na, Ca or Li, and m is 1 when M is Na or Li, and 2 when M is Ca).

17. The laminated polyester film of claim 16, wherein the ratio (Sp / Sa) of the maximum peak height (Sp) to the average surface roughness (Sa) of the surface of the resin layer is 50 or less.

18. The laminated polyester film of claim 16, wherein the adhesive resin of (a) comprises polyester resin or polyvinyl alcohol resin.

19. The laminated polyester film of claim 16, wherein the crosslinking agent described above (b) comprises a melamine compound.

20. The laminated polyester film of claim 16, wherein the crosslinking agent described above (b) comprises two or more compounds.

21. The laminated polyester film of claim 16, wherein the polyester film is composed of 3 layers.

22. The laminated polyester film of claim 21, wherein the polyester film has a surface layer C on the side opposite to the aforementioned surface (A).

23. The laminated polyester film of claim 22, wherein the average surface roughness (Sa) of the surface layer C is 3 nm or more and 20 nm or less.

24. The laminated polyester film of claim 22, wherein the maximum peak height (Sp) of the surface layer C is 10 nm or more and 220 nm or less.

25. The laminated polyester film of claim 16, having a release layer on the aforementioned resin layer.

26. The laminated polyester film of claim 25, wherein the release layer contains a cured silicone resin.

27. The multilayer polyester film of any one of claims 16 to 26, used as a support for ceramic blanks in the manufacturing process of multilayer ceramic capacitors.

28. The laminated polyester film of any one of claims 16 to 26, used as a support for ceramic blanks in the manufacturing process of automotive ceramic capacitors.

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