Polysiloxane release polyester film and its manufacturing method

Abstract

The objective of this invention is to provide a polysiloxane release polyester film and a method for manufacturing the same. This polysiloxane release polyester film can also be suitably used as a carrier film in the manufacture of multilayer ceramic capacitors, and exhibits excellent peelability and adhesion suitable for sheet forming from light to heavy peeling. The polysiloxane release polyester film of this invention has a coating layer formed using a release coating composition on at least one side of the polyester film. The release coating composition comprises an aqueous dispersion (1) of one or more polysiloxanes (A) containing alkenyl groups and / or Q units represented by SiO₄ / ₂; an aqueous dispersion (2) of polysiloxanes (B) containing hydrogen atoms directly bonded to Si atoms, represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier. The polysiloxane A has a number average molecular weight of 150,000 or more, and the Si atom content contained in the Q units is 0.05 mol% to 60 mol% or less.

Description

[Technical Field]

[0001] This invention relates to a polysiloxane release polyester film. More specifically, this invention relates to a polysiloxane release polyester film and a method for manufacturing the same, wherein the aforementioned polysiloxane release polyester film, in the forming of ceramic green sheets used in manufacturing multilayer ceramic capacitors, has peelability and adhesion suitable for forming from light to heavy peeling, and can prevent the aforementioned sheets from breaking or deforming. [Previous Technology]

[0002] Release films are used as carrier films for molding resin sheets or ceramic sheets. Polyester films are particularly used as the base material for release films due to their dimensional stability and heat resistance. In recent years, especially with the miniaturization and high reliability of multilayer ceramic capacitors, the thickness of manufactured ceramic green sheets has ranged from thick to thin. Therefore, the carrier film needs various properties suitable for the thickness of the paste. In the manufacture of multilayer ceramic capacitors, the rigidity of the ceramic green sheet decreases due to thinning, causing breakage when peeling the sheet; therefore, light peelability is required. Furthermore, in relatively thicker green sheets, the rigidity increases, causing the sheet to detach between the sheet and the release film during process handling, resulting in sheet deformation. Thus, there are situations where the peeling of ceramic sheets requires various peeling forces, ranging from light to heavy peeling. Furthermore, regardless of the thickness of the green sheet, tiny repulsion defects during the application of ceramic slurry can penetrate the sheet, resulting in pinholes or thickness variations, which significantly deteriorates the yield of multilayer ceramic capacitors. Therefore, the release layer of the release film needs to have coating uniformity.

[0003] Regarding these issues, although it has been proposed that a component consisting of a polysiloxane having a structure of trifunctional or tetrafunctional siloxane be added (for example, see Patent Document 1), the content of the polysiloxane is not specifically indicated, and the emulsion-type release agent is not mentioned.

[0004] Furthermore, although an aqueous coating composition is described that contains polysiloxane with Q units in a predetermined molar percentage range and polysiloxane having Si-H groups (for example, see Patent Document 2), the optimal molecular weight range, especially for polysiloxane containing Q units, is not described. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. Hei 9-1527. [Patent Document 2] Japanese Patent Application Publication No. 2021-11081. [Summary of the Invention]

[0006] [The problem the invention aims to solve]

[0007] In view of the foregoing, the present invention aims to provide a polysiloxane release PVC film and a method for manufacturing the same. The aforementioned polysiloxane release PVC film exhibits excellent peelability and adhesion, making it suitable for forming sheets with light to heavy peelability. It can also be preferably used as a carrier film, for example, in the manufacture of multilayer ceramic capacitors. [Means for solving the problem]

[0008] The inventors have conducted intensive research to solve the aforementioned problems and have found that, under certain specific conditions, even when using emulsion-type polysiloxane, a release film with appropriate peeling force from light to heavy peeling can be provided, thereby completing the present invention.

[0009] That is, the present invention provides the following polysiloxane release polyester film (polysiloxane release polyester film).

[0010] [1] A polysiloxane release polyester film having a coating layer formed using a release coating composition on at least one side of the polyester film, the release coating composition comprising: an aqueous dispersion (1) of one or more polysiloxanes (A), the polysiloxanes (A) containing alkenyl groups and / or Q units represented by SiO 4 / 2; an aqueous dispersion (2) of polysiloxanes (B), the polysiloxanes (B) having hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier; the number average molecular weight of the polysiloxanes A is 150,000 or more; the content of Si atoms contained in the Q units is 0.05 mol% or more to 60 mol% or less.

[0011] [2] As described in [1], when the total content of the aforementioned polysiloxane (A) and the aforementioned polysiloxane (B) is set to 100 parts by mass, the content of the aforementioned polysiloxane (B) is 3 parts by mass or more to 45 parts by mass or less.

[0012] [3] The polysiloxane release polyester film as described in [1] or [2], wherein the alkenyl group of the aforementioned polysiloxane (A) is vinyl.

[0013] [4] The polysiloxane release polyester film described in any of [1] to [3] has a peel strength of more than 20g / 25mm width to less than 400g / 25mm width after being attached to polyester adhesive tape.

[0014] [5] The polysiloxane release polyester film described in any of [1] to [4] is used in the manufacturing of ceramic green sheets for forming multilayer ceramic capacitors.

[0015] Furthermore, the present invention provides a method for manufacturing the following polysiloxane release polyester film.

[0016] [6] A method for manufacturing a polysiloxane release polyester film includes the step of forming a coating layer on at least one side of the polyester film using a release coating composition, wherein the release coating composition comprises: an aqueous dispersion (1) of one or more polysiloxanes (A), wherein the polysiloxanes (A) contain alkenyl groups and / or Q units represented by SiO 4 / 2; an aqueous dispersion (2) of polysiloxanes (B), wherein the polysiloxanes (B) have hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier; wherein the number average molecular weight of the polysiloxanes A is 150,000 or more; and wherein the content of Si atoms contained in the Q units is in the range of 0.05 mol% or more to 60 mol% or less.

[0017] [7] In the manufacturing method described in [6], when the total content of the aforementioned polysiloxane (A) and the aforementioned polysiloxane (B) is set to 100 parts by mass, the content of the aforementioned polysiloxane (B) is 3 parts by mass or more and 45 parts by mass or less.

[0018] [8] The manufacturing method as described in [6] or [7], wherein the alkenyl group of the aforementioned polysiloxane (A) is a vinyl group. [Invention Benefits]

[0019] The polysiloxane release polyester film of the present invention, having the aforementioned structure, serves as a release film for sheet forming, and becomes a release film with peel force suitable for sheet forming of thicknesses suitable for ceramic green sheets, and moderate peelability with less sheet deformation, and can manufacture sheets with reduced defect rate and high reliability.

[0020] Furthermore, the manufacturing method of the polysiloxane release polyester film of the present invention can efficiently and easily obtain a polysiloxane release polyester film with the aforementioned characteristics.

Implementation Method

[0021] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0022] [Polysiloxane Release Polyester Film] The polysiloxane release polyester film of the present invention has a coating layer formed using a release coating composition on at least one side of the polyester film. The release coating composition comprises: an aqueous dispersion (1) of one or more polysiloxanes (A), wherein the polysiloxanes (A) contain alkenyl groups and / or Q units represented by SiO 4 / 2; an aqueous dispersion (2) of polysiloxanes (B), wherein the polysiloxanes (B) have hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier, wherein the number average molecular weight of the polysiloxanes A is 150,000 or more, and the content of Si atoms contained in the Q units is 0.05 mol% or more to 60 mol% or less.

[0023] [Polyester film] The polyester film of the present invention may appropriately use known polyesters, such as the polyesters shown below.

[0024] (Polyester) The polyester constituting the polyester film used as the substrate film (hereinafter sometimes referred to as "substrate") in this invention is not particularly limited, and a substrate obtained by film forming of a polyester commonly used as a substrate for release films can be used. Preferably, it is a crystalline linear saturated polyester composed of an aromatic diacid component and a glycol component, and more preferably, for example, polyethylene terephthalate, polyethylene isophthalate, polyethylene 2,6-naphthalenedicarboxylate, polyethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexylenedimethylene terephthalate, polytrimethylene terephthalate, or copolymers of these resins as the main components. Among these, a polyester film formed of polyethylene terephthalate is particularly preferred. The repeating unit of polyethylene terephthalate (PET) is preferably 90 moles or more, more preferably 95 moles or more, and small amounts of other dicarboxylic acid components and glycol components may also be copolymerized. For example, in terms of cost, PET made solely from terephthalic acid and ethylene glycol is preferred.

[0025] Furthermore, known additives, such as antioxidants, light stabilizers, ultraviolet absorbers, and crystallizers, may be added within the range that does not impair the effect of the release film of the present invention. Due to the higher elastic modulus in both directions, the polyester film is preferably a biaxially aligned polyester film.

[0026] The intrinsic viscosity of the aforementioned polyester film is preferably between 0.50 dl / g and 0.70 dl / g, more preferably between 0.52 dl / g and 0.65 dl / g. When the intrinsic viscosity is 0.50 dl / g or higher, a large amount of breakage will not occur during the stretching step, which is preferable. Conversely, when the intrinsic viscosity is 0.70 dl / g or lower, the cutability is good when cutting to the predetermined product width, and dimensional defects will not occur, which is also preferable. Furthermore, the raw material granules are preferably thoroughly vacuum dried.

[0027] Furthermore, in this specification, when referred to as "polyester film", it means a polyester film having (layered) surface layer A and surface layer B.

[0028] The method for manufacturing the polyester film in this invention is not particularly limited, and conventionally used methods can be used. For example, it can be obtained by melting and extruding the aforementioned polyester into a film using an extruder, cooling it using a rotary cooling roller to obtain an unstretched film, and then biaxially stretching the aforementioned unstretched film to obtain a polyester film. The biaxially stretched film can be obtained by a method of biaxially stretching a longitudinally or transversely uniaxially stretched film sequentially in the transverse or longitudinal direction, or by a method of biaxially stretching an unstretched film simultaneously in the longitudinal and transverse directions.

[0029] In this invention, the stretching temperature during polyester film stretching is preferably set to be above the secondary transfer point (Tg) of the polyester. Preferably, the stretching is performed by more than 1 to less than 8 times in both the longitudinal and transverse directions, and more preferably by more than 2 to less than 6 times.

[0030] The thickness of the aforementioned polyester film is preferably 12 μm or more to 100 μm or less, more preferably 16 μm or more to 50 μm or less, and even more preferably 19 μm or more to 33 μm or less. If the film thickness is 12 μm or more, there is no risk of deformation due to heat during film production, processing steps, or molding, which is preferable. On the other hand, if the film thickness is 100 μm or less, the amount of waste film after use will not become excessive, which is preferable in terms of reducing environmental impact.

[0031] The aforementioned polyester film substrate may be a single layer or a multilayer of two or more layers. For example, the substrate film may also be a polyester film having: a surface layer A that substantially does not contain particles with a particle size of 1.0 μm or larger; and a surface layer B that contains particles. Preferably, surface layer A substantially does not contain inorganic particles with a particle size of 1.0 μm or larger.

[0032] In this sample, particles with a diameter of 1 nm or larger but less than 1.0 μm may also be present in the surface layer A. By making the surface layer A substantially free of particles with a diameter of 1.0 μm or larger (e.g., inorganic particles), the problem of defects caused by the transfer of particle shape from the substrate to the resin sheet can be reduced.

[0033] In a single sample, by ensuring that the surface layer A also does not contain particles with a particle size of less than 1.0 μm, the problem of particle shape transfer from the substrate to the resin sheet and resulting in defects can be more effectively suppressed.

[0034] In one embodiment, the aforementioned polyester film substrate is preferably a laminated film having a surface layer A that substantially does not contain inorganic particles on at least one side. This more effectively suppresses the problem of particle shapes in the substrate being transferred to the resin sheet and causing defects.

[0035] For example, the surface layer A, which substantially does not contain particles with a particle size of less than 1.0 μm, is preferably a state that also substantially does not contain particles with a particle size of 1.0 μm or larger.

[0036] Here, in this invention, "substantially free of particles" means, for example, when inorganic particles smaller than 1.0 μm are present, that the content is less than 50 ppm, preferably less than 10 ppm, and most preferably below the detection limit when inorganic elements are quantified using fluorescence X-ray analysis. This is because even without actively adding particles to the membrane, there is a possibility of contamination from foreign matter, raw material resin, or dirt from pipelines or devices attached to the membrane during the manufacturing process being shed and mixed into the membrane. Furthermore, "substantially free of particles larger than 1.0 μm" means that particles larger than 1.0 μm are not actively included.

[0037] In the case of a laminated polyester film consisting of two or more layers, it is preferable to have a surface layer B that may contain inorganic particles on the opposite side of the surface layer A, which is substantially free of inorganic particles.

[0038] As a laminated structure, examples include: designating the layer on the side with the release layer as layer A, the layer on the opposite side of layer A as layer B, and the core layer other than layers A and B as layer C. The layer structure in the thickness direction is a laminated structure such as release layer / A / B or release layer / A / C / B. Of course, layer C can also be composed of multiple layers. Furthermore, the surface layer B may not contain inorganic particles. In this case, in order to impart slidability for winding the film into a roll, it is preferable to provide a coating containing at least inorganic particles and an adhesive on the surface layer B.

[0039] In the polyester film substrate of the present invention, from the viewpoint of film slippage or ease of air degassing, the surface layer B, which forms the side opposite to the surface on which the release layer is coated, preferably contains inorganic particles, and more preferably uses silicon dioxide particles and / or calcium carbonate particles. The content of inorganic particles contained is preferably between 5000 ppm and 15000 ppm in total in the surface layer B.

[0040] At this time, the average surface roughness (Sa) of the surface layer B is preferably in the range of 1 nm to 40 nm. More preferably, it is in the range of 5 nm to 35 nm. When the total amount of silicon dioxide particles and / or calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, air can be uniformly dispersed when the film is wound into a roll, the winding posture is good and the planarity is good, so it is suitable for manufacturing ultrathin ceramic green sheets. Furthermore, when the total amount of silicon dioxide particles and / or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, lubricant agglomeration is not likely to occur, and coarse protrusions will not be generated, so the quality is stable when manufacturing ultrathin ceramic green sheets, which is better.

[0041] As for the particles contained in the aforementioned layer B, in addition to silicon dioxide and / or calcium carbonate, inert inorganic particles and / or heat-resistant organic particles may also be used. However, from the viewpoint of transparency and cost, silicon dioxide particles and / or calcium carbonate particles are preferred. Other inorganic particles that can be used include: alumina-silicon dioxide composite oxide particles, hydroxyapatite particles, etc. Heat-resistant organic particles include: cross-linked polyacrylic acid particles, cross-linked polystyrene particles, guanidine-based particles, etc. When using silicon dioxide particles, porous colloidal silicon dioxide is preferred. When using calcium carbonate particles, from the viewpoint of preventing lubricant detachment, lightweight calcium carbonate obtained by surface treatment using a polyacrylic acid polymer compound is preferred.

[0042] The average particle size of the inorganic particles added to the aforementioned surface layer B is preferably 0.1 μm or more to 2.0 μm or less, and more preferably 0.3 μm or more to 1.0 μm or less. If the average particle size of the inorganic particles is 0.1 μm or more, the release film has good sliding properties, which is preferred. Furthermore, if the average particle size is 2.0 μm or less, there is no risk of adversely affecting the smoothness of the release layer surface, and therefore there is no risk of pinholes forming in the ceramic green sheet, which is also preferred.

[0043] Furthermore, in order to improve the adhesion of the release layer or prevent static electricity, a coating may be applied to the surface of surface layer A and / or surface layer B before or after the film is stretched in the film-making step, or corona treatment may be performed.

[0044] Furthermore, the peel strength of the polysiloxane release polyester film of the present invention after being attached to the polyester adhesive tape can be set to 20g / 25mm width or more to 400g / 25mm width or less. The lower limit of the aforementioned peel strength can be, for example, set to 30g / 25mm width or more, 40g / 25mm width or more, 50g / 25mm width or more, 70g / 25mm width or more, 100g / 25mm width or more, 120g / 25mm width or more, 150g / 25mm width or more, 180g / 25mm width or more, etc. The upper limit of the aforementioned peel strength can be, for example, set to 380g / 25mm width or less, 350g / 25mm width or less, 330g / 25mm width or less, 300g / 25mm width or less, 280g / 25mm width or less, 250g / 25mm width or less, 230g / 25mm width or less, 200g / 25mm width or less, etc. The aforementioned peel strength is preferably between 20g / 25mm width and above and 400g / 25mm width and below. The polysiloxane release polyester film of the present invention has the aforementioned structure. Therefore, for example, by introducing polysiloxane resin (Q-unit resin) into polysiloxane main agent (polysiloxane A), even when the crosslinking agent is relatively small, it can possess release properties such as hardness suitable for use as a release film for sheet formation and adhesion. Moreover, by adjusting the amount of crosslinking agent added, the peel force can be controlled from light peel to heavy peel, which has extremely high industrial value.

[0045] In this invention, the aforementioned adhesive tape peel strength refers to the strength obtained by applying polyester adhesive tape (manufactured by Nitto Denko Corporation, No. 31B) to the surface of the coating layer (release layer) of the release film, pressing it with a 5kg pressing roller and leaving it for more than 30 minutes, and then measuring the peel strength between the release layer and the adhesive tape using a peel strength tester (peel angle 180 degrees, peel speed 300mm / min, unit: g / 25mm width).

[0046] [Release Coating Composition] The release coating composition of the present invention comprises: an aqueous dispersion (1) of one or more polysiloxanes (A), wherein the polysiloxanes (A) contain alkenyl groups and / or Q units represented by SiO 4 / 2; an aqueous dispersion (2) of polysiloxanes (B), wherein the polysiloxanes (B) have hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier.

[0047] (One or more polysiloxanes (A) containing an alkenyl group and / or a Q unit represented by SiO 4 / 2) As an example of the polysiloxane (A) containing an alkenyl group and / or a Q unit represented by SiO 4 / 2 (hereinafter, sometimes simply referred to as "Q unit") in the present invention, an organopolysiloxane (hereinafter, sometimes referred to as "polysiloxane (A)") having the following general formula (I) is exemplified. R 1 aR 2 bSiO (4-ab) / 2···(I) (In formula (I), R 1 is an alkenyl group with 2 to 8 carbons, R 2 is a monovalent saturated hydrocarbon group with 1 to 16 carbons selected from alkyl or aryl groups, and a and b represent a being 0 to 3 and b being 0 to 3, respectively, and satisfying a + b ≤ 3 integers).

[0048] Examples of alkenyl groups represented by R1, having 2 to 8 carbon atoms, include vinyl, allyl, butenyl, pentenyl, and hexenyl, with vinyl being particularly preferred. Examples of alkyl groups represented by R2 include methyl, ethyl, propyl, and butyl, and examples of aryl groups include phenyl and tolyl. From the perspective of easy exfoliation, it is preferable that, for example, 50 mol% or more of the substituent in R2 is methyl.

[0049] The polysiloxane (A) containing alkenyl and / or Q units must contain Q units. However, in the case of multiple polysiloxanes (A) containing alkenyl and / or Q units, it is sufficient that any one of the polysiloxanes (A) contains a Q unit. By including Q units in the polysiloxane release layer, the film hardness of the polysiloxane release layer can be increased, thereby suppressing adhesive loss when peeling the sheet, thus facilitating easy peeling. Furthermore, if the polysiloxane containing Q units is included in the aforementioned polysiloxane containing alkenyl groups, the wettability is also improved, thus suppressing pinhole defects when coating the sheet. The content of Si atoms contained in the Q unit is 0.05 mol% to 60 mol% relative to the total Si atoms in the polysiloxane (A) containing alkenyl groups and / or Q units, preferably 0.1 mol% to 55 mol%, and more preferably 1.0 mol% to 50 mol%. When the content of Si atoms contained in the Q unit is less than 0.05 mol%, sufficient film hardness cannot be achieved, which is not conducive to light peeling. If the content of Si atoms contained in the Q unit exceeds 60 mol%, excessive wettability is imparted, resulting in strong adhesion to the sheet, thus causing coagulation and cracking on the surface of the sheet (excessive heavy peeling).

[0050] Furthermore, the number average molecular weight of the polysiloxane (A) containing alkenyl and / or Q units is preferably 150,000 or more, for example, 180,000 or more, 200,000 or more, 220,000 or more, etc. Also, the number average molecular weight of the polysiloxane (A) containing alkenyl and / or Q units can be, for example, set to 1,000,000 or less, and can be set to 900,000 or less, 800,000 or less, 700,000 or less, 600,000 or less, 500,000 or less, 400,000 or less, etc. When the molecular weight is less than 150,000, if the crosslinking agent is reduced, the crosslinking formation of the release coating is insufficient, and the adhesive loss during sheet peeling cannot be suppressed, resulting in excessive re-peeling, and the amount of polysiloxane transferred to the adherend also increases.

[0051] The polysiloxane (A) containing alkenyl and / or Q units in this invention can be manufactured using known methods. Furthermore, the polysiloxane (A) containing alkenyl and / or Q units in this invention is preferably contained in the aforementioned composition in the form of an aqueous dispersion (aqueous dispersion (1)).

[0052] When the aforementioned polysiloxane (A) containing alkenyl and / or Q units is made into an aqueous dispersion (aqueous dispersion (1)), the mass percentage of the aforementioned polysiloxane (A) containing alkenyl and / or Q units in the aqueous dispersion (1) may be set to, for example, more than 1 mass percentage to less than 50 mass percentage, or more than 3 mass percentage to less than 40 mass percentage, more than 5 mass percentage to less than 30 mass percentage, more than 10 mass percentage to less than 20 mass percentage, etc.

[0053] (Polysiloxane (B) having hydrogen atoms directly bonded to Si atoms represented by Si-H groups) As the polysiloxane (B) having hydrogen atoms directly bonded to Si atoms represented by Si-H groups in this invention (hereinafter, sometimes referred to as "polysiloxane (B)" or "polysiloxane (B) containing Si-H groups"), an example is an organohydrogenated polysiloxane having the structure represented by the following general formula (II). R 3 cH dSiO (4-cd) / 2···(II) (In formula (II), R 3 is a monovalent saturated hydrocarbon group selected from alkyl or aryl with 1 to 16 carbon atoms, c and d represent c being 0 to 2 and d being 1 to 3, respectively, and satisfying c + d ≤ 3).

[0054] Examples of alkyl groups represented by R3 include methyl, ethyl, propyl, butyl, etc., and examples of aryl groups include phenyl, tolyl, etc. From the perspective of easy stripping, it is preferable that 50 mol% or more of the substituents in R3 are methyl.

[0055] The aforementioned polysiloxane (B) containing Si-H groups, from the viewpoint of curing properties, preferably has at least 3, more preferably 5 or more hydrogen atoms bonded to Si atoms in the polysiloxane 1 molecule.

[0056] The aforementioned polysiloxane (B) containing Si-H groups can be manufactured using known methods. Furthermore, the polysiloxane (B) containing Si-H groups in this invention is preferably contained in the aforementioned composition in the form of an aqueous dispersion (aqueous dispersion (2)).

[0057] When the aforementioned polysiloxane (B) containing Si-H groups is made into an aqueous dispersion (aqueous dispersion (2)), the mass percentage of the aforementioned polysiloxane (B) containing Si-H groups in the aqueous dispersion (2) may be set to, for example, more than 1 mass percentage to less than 50 mass percentage, or more than 3 mass percentage to less than 40 mass percentage, more than 5 mass percentage to less than 30 mass percentage, more than 10 mass percentage to less than 20 mass percentage, etc.

[0058] Furthermore, when the total content of polysiloxane (A) containing alkenyl groups and / or Q units represented by SiO 4 / 2 and polysiloxane (B) containing Si-H groups is set to 100 parts by mass, the content of polysiloxane (B) containing Si-H groups is preferably 1 part by mass to 60 parts by mass, more preferably 2 parts by mass to 50 parts by mass, and more preferably 3 parts by mass to 45 parts by mass. When the aforementioned content is less than 1 part by mass, it is difficult to carry out the curing reaction, so sometimes sufficient coating hardness cannot be obtained. When the aforementioned content exceeds 60 parts by mass, Si-H is excessively precipitated to the surface and firmly bonded to the green sheet, so as a result, re-peeling may sometimes occur.

[0059] (Polysiloxane Content) In the release coating composition of the present invention, based on the mass of the solids content of the aforementioned composition, the total amount of polysiloxane (A) solids content containing alkenyl groups and / or Q units represented by SiO 4 / 2 and polysiloxane (B) solids content containing Si-H groups is preferably 70% by mass or more. Furthermore, the preferred content of each polysiloxane solids content is 80% by mass or more to 97% by mass or less. Here, polysiloxane solids content refers to the amount after removing aqueous solvents, and the mass of solids content of the composition refers to the total amount of solids content of each additive. If the total amount of the aforementioned polysiloxane solids content is less than the lower limit, the area covered by polysiloxane decreases relative to the film surface forming the coating, the peel force increases, and sometimes uneven peel force occurs.

[0060] (Aqueous solvent) Water is preferably used as the aqueous solvent for forming the various polysiloxane aqueous dispersions of the present invention. By using an aqueous solvent, the polysiloxane release layer can be formed in the step of manufacturing the release film without the need for explosion-proof equipment and organic solvent recovery equipment required for using organic solvents.

[0061] (Nonionic Emulsifier) ​​To improve the stability and shear resistance of aqueous dispersions, nonionic emulsifiers are used to prepare each aqueous dispersion system. Furthermore, the inventors have conducted extensive research, and the results confirm that, in order to prevent the aqueous dispersions from agglomerating and to avoid affecting the curing reaction of polysiloxane, the emulsifier must be nonionic. Cationic emulsifiers can affect the curing reaction of polysiloxane and can be locally present in the coating film, for example, by seeping to the surface and affecting release properties, leading to re-peeling. Also, although the details are unclear, when using cationic emulsifiers, the polysiloxane aqueous dispersions tend to agglomerate.

[0062] As a nonionic emulsifier, the HLB value is preferably in the range of 6 to 18. Examples include at least one type of alkylene oxide adduct selected from higher alcohols or higher fatty acids, esters of alkylene oxide adducts of higher fatty acids and alcohols, alkylene oxide adducts of alkanolamides, alkylene oxide adducts of sorbitan esters, alkylene oxide adducts of higher fatty acid glycerides, etc. These nonionic emulsifiers can be used alone or in combination of two or more. Here, the HLB value is calculated using Griffin's formula.

[0063] Examples of epoxides include ethylene oxide, propylene oxide, and butane oxide; one or more of these may be used. When using multiple types, regardless of whether they are block or random addition forms, the HLB value is preferably in the range of 6 to 18, and more preferably in the range of 10 to 15. Examples of these nonionic emulsifiers include, for example, polyoxyethylene lauryl ether and polyoxyethylene tridecyl ether. If a nonionic emulsifier with an HLB value deviating from the aforementioned range is used as an emulsifier for a polysiloxane aqueous dispersion, the emulsifying and dispersing power and the stability of the aqueous dispersion may sometimes decrease. The nonionic emulsifier is preferably used in the range of 0.1% to 20% by mass relative to the total solids content, more preferably in the range of 0.2% to 15% by mass, and more preferably in the range of 0.5% to 10% by mass. If the emulsification is below this range, it tends to fail. If it is above this range, it may cause re-peeling.

[0064] (Platinum-based catalyst) In the release coating composition constituting the coating layer of the present invention, in order to enable one or more polysiloxanes (A) containing alkenyl groups and / or Q units to undergo an addition reaction with polysiloxanes (B) containing Si-H groups, a platinum-based catalyst is required.

[0065] As a platinum-based catalyst, known platinum-based catalysts can be used, such as platinum chloride or platinum chloride acid. Considering the dispersibility of the aforementioned platinum-based catalysts with polysiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex (Karstedt catalyst) can also be used. By dispersing the platinum-based catalyst while emulsifying the polysiloxane, uniform dispersion can be ensured. The aforementioned platinum-based catalysts can be used alone or in combination of two or more.

[0066] Preferably, the amount of platinum-based catalyst is 100 parts by mass relative to the combined mass of an aqueous dispersion (1) containing one or more alkenyl and / or Q-unit polysiloxanes (A) and an aqueous dispersion (2) containing Si-H groups, wherein the mass of platinum element is in the range of 10 ppm to 800 ppm. By setting it within the aforementioned range, the curing of polysiloxane can be sufficiently carried out. Furthermore, the formation of polysiloxane aggregates can be suppressed, thereby obtaining a release polyester film with excellent surface properties. If the mass ratio of platinum element exceeds the upper limit, there is a tendency for the addition reaction of alkenyl and Si-H groups to accelerate, resulting in the formation of polysiloxane aggregates. From the aforementioned point of view, the amount of platinum-based catalyst is more preferably 600 ppm or less, more preferably 500 ppm or less, particularly preferably 200 ppm or less, and most preferably 150 ppm or less. Furthermore, if the mass ratio of platinum is below the lower limit, the addition reaction cannot proceed, leading to poor curing of the polysiloxane. Based on the aforementioned points, the amount of platinum catalyst is preferably 15 ppm or more, more preferably 20 ppm or more, especially 25 ppm or more, and most preferably 40 ppm or more.

[0067] (Cross-linking reaction inhibitor) To inhibit the activity of platinum-based catalysts at room temperature, it is preferable to contain a cross-linking reaction inhibitor in the aqueous coating composition. The aforementioned cross-linking reaction inhibitor is preferably a cross-linking reaction inhibitor with an alkynyl group. There is no particular limitation on the type of cross-linking reaction inhibitor with an alkynyl group, as long as it contains an alkynyl group. Specifically, examples include: 1-ethynyl-1-cyclohexanol, 4-ethyl-1-octyyn-3-ol, 3-methyl-1-dodecyn-3-ol, 3,7,11-trimethyl-1-dodecyn-3-ol, 1,1-diphenyl-2-propyn-3-ol, 3-ethyl-6-ethyl-1-nonyn-3-ol, 3-methyl-1-pentadecanyn-3-ol, 2,5-dimethyl-3-hexyn-2,5-diol, and 3-phenyl-1-butyn-3-ol. These can be used alone or in combination of two or more. Since an aqueous emulsion coating composition is used in this invention, from the viewpoint of balancing the affinity and solubility for water with the coordination ability to platinum and the boiling point, it is preferable to use a crosslinking reaction inhibitor having the exemplified alkynyl and hydroxyl groups.

[0068] Relative to the mass of the aqueous coating composition used to form the release layer, the content of the crosslinking reaction inhibitor is preferably 5 ppm to 1000 ppm, more preferably 10 ppm to 700 ppm, and even more preferably 20 ppm to 500 ppm. When the content of the aforementioned crosslinking reaction inhibitor is above the lower limit, the pot life becomes longer, and the addition curing reaction of polysiloxane at room temperature is not easily carried out, making it less likely to produce polysiloxane aggregates. Furthermore, if the content of the aforementioned crosslinking reaction inhibitor is below the upper limit, after the target material is peeled off, polysiloxane is not easily transferred to the target material, the amount of reaction inhibitor volatilized during heat treatment is reduced, and therefore, contamination is less likely to occur inside the oven.

[0069] (Other components) Within the scope of the present invention, such as adhesive agents for substrates, colorants, ultraviolet absorbers, particles, antistatic agents, etc., may also be added to the release coating composition of the present invention without impairing the subject matter of the present invention.

[0070] (Preparation of Polysiloxane Aqueous Dispersions) When preparing the various polysiloxane aqueous dispersions of the present invention, emulsification methods using the aforementioned polysiloxane components, aqueous solvents, and emulsifiers can be exemplified. Emulsification of these components can be performed using known methods, such as mechanical emulsification of pre-prepared polysiloxane, emulsifiers, and other components as needed in an aqueous medium using a homogenizer, an Agi-Homo-Mixer, an Ultra Planetary Mixer, or other stirring devices.

[0071] Furthermore, the particle size of the aqueous dispersion can be adjusted by adjusting the size of the stirring blades, the stirring speed, and the stirring time. The average particle size of each polysiloxane aqueous dispersion of the present invention is preferably 200 nm or less, and more preferably 100 nm or more but less than 200 nm.

[0072] [Coating Layer] In this invention, a coating layer (release layer) is formed on at least one side of a polyester film by using the release coating composition of this invention. The coating layer (release layer) of this invention is formed by applying the aforementioned release coating composition onto the aforementioned polyester film and then drying it.

[0073] In this invention, the coating thickness, measured after drying, is preferably between 5 nm and 70 nm. If the coating thickness does not reach the lower limit, the release properties may be insufficient. Furthermore, if the coating thickness exceeds the upper limit, the peel strength increases. In addition, the coating solution must be of a high concentration or the coating amount must be increased, which may make coating difficult.

[0074] When applying the release coating composition of the present invention onto a polyester film, an aqueous coating solution containing the aforementioned composition is prepared. Using the mass of the coating solution as a reference, the solid content concentration of the aqueous coating solution is preferably 20% by mass or less, and more preferably 1% by mass or more to 10% by mass or less. If the solid content concentration in the aqueous coating solution does not reach the lower limit, the coating properties of the polyester film may be insufficient. Furthermore, if the solid content concentration exceeds the upper limit, the stability of the coating solution or the appearance of the coating layer may sometimes deteriorate. Water is preferably used as the aqueous solvent for adjusting the solid content concentration.

[0075] The coating of the aqueous coating liquid onto the polyester film can be carried out at any stage, but it is preferred to carry out it during the manufacturing process of the polyester film, and even more preferably to coat the polyester film before the alignment crystallization is completed.

[0076] Here, the polyester film before the completion of crystallization alignment includes an unstretched film, a uniaxially aligned film obtained by aligning the unstretched film in either the longitudinal (hereinafter sometimes referred to as the film continuous forming direction, long side direction, MD direction) or transverse (hereinafter sometimes referred to as the direction orthogonal to the longitudinal direction, width direction, TD direction), and an aligned film obtained by low-ratio stretching alignment in both the longitudinal and transverse directions (a biaxially stretched film before the alignment crystallization is finally completed by further stretching in the longitudinal and transverse directions). Preferably, this is called in-line coating, which involves coating the unstretched film or the uniaxially stretched film obtained by alignment in one direction with an aqueous coating solution of the aforementioned components, and directly performing longitudinal stretching and / or transverse stretching and heat fixation. The coating layer can be dried by a stretching step or heat fixation treatment after coating, and a drying step can be added as needed. Furthermore, when a catalyst is used to harden the composition to obtain a hardened film, the composition can be hardened by an extension step or a heat-fixing treatment, and a hardening step can be added as needed.

[0077] When coating an aqueous coating liquid onto a polyester film, it is preferable to perform physical treatments such as corona surface treatment, flame treatment, or plasma treatment on the film surface as a pretreatment to improve the coatability, or to use the aforementioned emulsifier as a wetting agent together with the composition.

[0078] As a coating method, any known coating method can be used. For example, roller coating, gravure coating, roller brush coating, spray coating, pneumatic doctor blade coating, impregnation coating, curtain coating, etc. can be used alone or in combination.

[0079] [Method for manufacturing polysiloxane release polyester film] The method for manufacturing polysiloxane release polyester film of the present invention includes the step of forming a coating layer on at least one side of a polyester film using a release coating composition, wherein the release coating composition comprises: an aqueous dispersion (1) of one or more polysiloxanes (A), wherein the polysiloxanes (A) contain alkenyl groups and / or Q units represented by SiO 4 / 2; an aqueous dispersion (2) of polysiloxanes (B), wherein the polysiloxanes (B) have hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier, wherein the number average molecular weight of the polysiloxanes A is 150,000 or more, and the content of Si atoms contained in the Q units is in the range of 0.05 mol% or more to 60 mol% or less.

[0080] The method for manufacturing the polysiloxane release polyester film of the present invention can efficiently and easily obtain a polysiloxane release polyester film possessing the aforementioned characteristics. Furthermore, the manufacturing method shown herein is an example, and the present invention is not limited thereto.

[0081] In the aforementioned manufacturing method, the descriptions in this specification relating to the aforementioned polysiloxane release polyester film and the like may be appropriately applied to each component.

[0082] As for the step of forming a coating layer using a release coating composition with an aqueous dispersion in the aforementioned manufacturing method, any method that forms a coating layer using a release coating composition with an aqueous dispersion on a film is acceptable, and known methods may be used appropriately. [Example]

[0083] The present invention will be specifically described through embodiments, but the present invention is not limited to the following embodiments. Furthermore, the physical properties or characteristics in the embodiments are measured or evaluated using the methods described below. Also, when expressed as "parts", it means "parts by mass".

[0084] The various measurements and evaluations in the embodiments are performed in the following manner.

[0085] (1) Adhesive tape peel strength refers to the strength obtained by bonding polyester adhesive tape (manufactured by Nitto Denko Corporation, No. 31B) to the surface of the coating layer (release layer) of the release film, pressing it with a 5kg pressing roller, and leaving it for more than 30 minutes, and then measuring the peel strength between the release layer and the adhesive tape using a peel strength tester (peel angle 180 degrees, peel speed 300mm / min, unit: g / 25mm width). The peel strength of the polysiloxane release polyester film of the present invention is preferably between 20g / 25mm width and above and 400g / 25mm width and below.

[0086] (2) Determination of Residual Adhesion Rate The peel strength of the polyester adhesive tape (manufactured by Nitto Denko, No. 31B) after being applied to a cold-rolled stainless steel sheet (SUS304) as specified in JIS G4305 is taken as the basic adhesion force (f0). Furthermore, the aforementioned polyester adhesive tape is pressed onto the release layer surface of the release polyester film using a 5kg pressing roller, and after maintaining for 30 seconds, the adhesive tape is peeled off. The peel strength of this peeled adhesive tape after being applied to the aforementioned stainless steel sheet is measured and taken as the residual adhesion force (f). The residual adhesion rate is calculated using the following formula based on the obtained extrusion adhesion force (f0) and residual adhesion force (f). Furthermore, the peel angle is set to 180 degrees and the peel speed is set to 300 mm / min. Residual adhesion rate (%) = (f) / (f0) × 100 The residual adhesion rate is preferably 90% or more, indicating a higher polysiloxane crosslinking density. Furthermore, if the cross-linking rate is less than 90%, it indicates insufficient cross-linking.

[0087] [Examples 1 to 3, Comparative Examples 1 to 4] 0.1% by mass of molten polyethylene terephthalate ([η] = 0.64 dl / g, Tg = 78°C) containing calcium carbonate particles with an average particle size of 0.7 μm was extruded from a die and cooled in a cooling roller by conventional methods to form an unstretched film. After being stretched longitudinally to 3.6 times, an aqueous coating liquid (a water dispersion with a solid content of 3% by mass) prepared by mixing the components in the manner shown in Table 1 was uniformly coated on the surface of the film using a roller coater.

[0088] Subsequently, the coated film is dried at 115°C for about 5 seconds and stretched laterally to 4.5 times at 145°C, and then heat-fixed at 230°C for about 5 seconds to obtain a 25µm biaxially stretched polyester film with the coating layer shown in Table 1.

[0089] (Aqueous dispersion of polysiloxane (1-a) containing alkenyl and Q units) Using an emulsification device (manufactured by NPLAO Co., Ltd., device name "Ultra Planetary Mixer") capable of stirring the entire container, a raw material consisting of 95% by mass of polysiloxane (1) and 5% by mass of polyoxyethylene tridecyl ether (manufactured by Takemoto Oils Co., Ltd., trade name "New Calgen D-1208") as a surfactant was mechanically emulsified in an aqueous medium to obtain an aqueous dispersion of polysiloxane (1-a) with a solid content of 20% by mass. Furthermore, by adjusting the stirring speed and stirring time during emulsification, the emulsion particle size was adjusted to an average particle size of 200 nm.

[0090] Furthermore, the composition of polysiloxane (1-a) is as follows: in formula (I), R1 is vinyl, R2 is methyl, and there is only one vinyl unit bonded to the silicon directly bonded to the vinyl, totaling 6.00 mol; in formula (I), there is 60.00 mol of the constituent unit composed of Q units of a=b=0; and in formula (I), there is 34.00 mol of the constituent unit of methyl, a=0, b=2 (with a=0, b=3 at both ends); and the number average molecular weight is adjusted to be 240000 (1-a). R 1 aR 2 bSiO (4-ab) / 2···(I) (In formula (I), R 1 is an alkenyl group with 2 to 8 carbons, R 2 is a monovalent saturated hydrocarbon group with 1 to 16 carbons selected from alkyl or aryl groups, and a and b represent a being 0 to 3 and b being 0 to 3, respectively, and satisfying the integer a + b ≤ 3).

[0091] (Aqueous dispersion of polysiloxane (1-b) containing alkenyl groups excluding Q units) Using an emulsification device (manufactured by NPLabo Co., Ltd., device name "Ultra Planetary Mixer") capable of stirring the entire container, a raw material consisting of 95% by mass of polysiloxane (1-b) and 5% by mass of polyoxyethylene tridecyl ether (manufactured by Takemoto Oils Co., Ltd., trade name "New Calgen D-1208") as a surfactant was mechanically emulsified in an aqueous medium to obtain an aqueous dispersion of polysiloxane (1-b) with a solid content of 20% by mass. Furthermore, by adjusting the stirring speed and stirring time during emulsification, the emulsion particle size was adjusted to an average particle size of 200 nm.

[0092] Furthermore, the composition of polysiloxane (1-b) is as follows: in formula (I), R1 is vinyl, R2 is methyl, only one vinyl is bonded to the silicon directly bonded to the vinyl, the vinyl is bonded to the terminal silicon atom, and the number of repeating silicon atoms bonded to the vinyl is 3; and the constituent unit of dimethylsiloxane (with vinyl at both ends); and the number of repeating units of the latter constituent unit is adjusted to a number average molecular weight of 40,000.

[0093] (Aqueous dispersion of Si-H group polysiloxane (2)) Using an emulsification device (manufactured by NPLabo Co., Ltd., device name "Ultra Planetary Mixer") capable of stirring the entire container, a raw material consisting of 97% by mass of Si-H group polysiloxane (2) and 3% by mass of polyoxyethylene tridecyl ether (manufactured by Takemoto Oils Co., Ltd., trade name "New Calgen D-1208") as a surfactant was mechanically emulsified in an aqueous medium to obtain an aqueous dispersion (2) containing Si-H group polysiloxane (2) with a solid content of 10% by mass. Furthermore, the emulsion particle size was adjusted to an average particle size of 160 nm by adjusting the stirring speed and stirring time during emulsification. R 3 cH dSiO (4-cd) / 2···(II) (In formula (II), R 3 is a monovalent saturated hydrocarbon group selected from alkyl or aryl groups with 1 to 16 carbon atoms, and c and d represent c from 0 to 2 and d from 1 to 3, respectively, and satisfying the integer c + d ≤ 3).

[0094] Furthermore, the polysiloxane composition containing Si-H groups is composed of the following: in formula (II), R3 is methyl, c=d=1, that is, only one hydrogen group is bonded to the silicon directly bonded to the hydrogen group, the hydrogen atom is not bonded to the terminal silicon atom, and the number of repetitions of the constituent unit with silicon atoms directly bonded to the hydrogen group is 30; and the constituent unit of dimethylsiloxane (with methyl groups at both ends); and by adjusting the number of repetitions of the latter constituent unit, the number average molecular weight is adjusted to 5000.

[0095] (Preparation of polysiloxane coating solution) In a polysiloxane aqueous dispersion prepared by mixing a polysiloxane (1-a) aqueous dispersion or a polysiloxane (1-b) aqueous dispersion and a polysiloxane (2) having Si-H groups in a manner that is as shown in Table 1, a platinum-based catalyst of the following amount with a total coating liquid mass of 40 ppm relative to the total mass of polysiloxane (1-a) and polysiloxane (2) and a crosslinking reaction inhibitor of the following amount with a coating mass of 200 ppm are mixed as an aqueous coating composition (release coating composition), and the solid component concentration of the coating solution is diluted with water in such a way that the dry coating film thickness is 40 nm to prepare a coating solution. Platinum-based catalyst: Platinum-based catalyst emulsion (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "CAT-PM-10A") Crosslinking reaction inhibitor: 1-ethynylcyclohexanol (manufactured by Alfa Lancaster)

[0096] The aforementioned formulation and results are shown in Table 1. Furthermore, the numerical values ​​of each polysiloxane represent the mass parts of the solids component.

[0097] [Table 1] Number average molecular weight Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Polysiloxane (1-a) 240,000 95 75 65 98 50 Polysiloxane (1-b) 40,000 95 65 Polysiloxane (2) 5,000 5 15 35 2 50 5 35 Adhesive tape peel strength g / 25mm 384 57 32 450 18 7 twenty three Residual adhesion rate % 92 93 97 92 87 80 88

[0098] As shown in Table 1, the films of the embodiments of the present invention exhibit excellent peelability and residual adhesion. This is because a specific composition containing polysiloxane with extremely high molecular weight is used to obtain films with various peelability and excellent residual adhesion. On the other hand, in Comparative Example 1, insufficient crosslinking led to re-peeling. Also, in Comparative Example 2, the increase in SiH residues in polysiloxane (2) led to increased transfer and decreased residual adhesion. Also, in Comparative Example 3, insufficient crosslinking led to increased transfer of the main agent and decreased residual adhesion. Also, in Comparative Example 4, the increase in SiH residues in polysiloxane (2) led to increased transfer and decreased residual adhesion.

Claims

1. A polysiloxane release polyester film, having at least one side of the polyester film a coating layer formed using a release coating composition, the release coating composition comprising: an aqueous dispersion (1) of one or more polysiloxanes (A), the polysiloxanes (A) containing alkenyl groups and / or Q units represented by SiO4 / 2; an aqueous dispersion (2) of polysiloxanes (B), the polysiloxanes (B) having hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier; wherein the total amount of the solids component of the polysiloxanes (A) and the solids component of the polysiloxanes (B) in the release coating composition is 70% by mass or more; When the total content of the aforementioned polysiloxane (A) and the aforementioned polysiloxane (B) is set to 100 parts by mass, the content of the aforementioned polysiloxane (B) is 3 parts by mass or more to 45 parts by mass or less; relative to the mass of the aforementioned aqueous coating composition, the content of the aforementioned crosslinking reaction inhibitor is 5 ppm or more to 1000 ppm or less; the amount of the aforementioned platinum-based catalyst is 100 parts by mass relative to the total amount of the aforementioned aqueous dispersion (1) and the aforementioned aqueous dispersion (2), and the platinum-based catalyst is included in the range of 10 ppm or more to 800 ppm by mass of platinum element; the aforementioned nonionic emulsifier is used in the range of 0.1% by mass or more to 20% by mass relative to the total solids content; the number average molecular weight of the aforementioned polysiloxane A is 150,000 or more; the content of Si atoms contained in the aforementioned Q unit is 0.05 mol% or more to 60 mol% or less; Furthermore, the residual adhesion rate of the aforementioned polysiloxane release polyester film obtained by the following method is 90% or more: The peel strength of the polyester adhesive tape (manufactured by Nitto Denko, No. 31B) after being attached to a cold-rolled stainless steel sheet (SUS304) as specified in JIS G4305 is measured as the basic adhesion force (f0). The aforementioned polyester adhesive tape is pressed onto the release layer surface of the aforementioned polysiloxane release polyester film using a 5kg pressing roller. After maintaining the pressure for 30 seconds, the aforementioned polyester adhesive tape is peeled off. The peel strength of the aforementioned polyester adhesive tape after being attached to the aforementioned stainless steel sheet is measured as the residual adhesion force (f). The residual adhesion rate is calculated using the following formula based on the obtained basic adhesion force (f0) and the aforementioned residual adhesion force (f): Residual adhesion rate (%) = (f) / (f0) × 100 Here, the peel angle is set to 180 degrees and the peel speed is set to 300 mm / min.

2. The polysiloxane release polyester film as described in claim 1, wherein the alkenyl group of the aforementioned polysiloxane (A) is vinyl.

3. The polysiloxane release polyester film described in claim 1 has a peel strength of more than 20g / 25mm width and less than 400g / 25mm width after being attached to polyester adhesive tape.

4. The polysiloxane release polyester film as described in claim 1, wherein the aforementioned crosslinking reaction inhibitor is a crosslinking reaction inhibitor having an alkyne group.

5. The polysiloxane ionomer film described in any one of claims 1 to 4, used to form ceramic green sheets in the manufacture of multilayer ceramic capacitors.

6. A method for manufacturing a polysiloxane release polyester film, comprising the step of forming a coating layer on at least one side of the polyester film using a release coating composition, wherein the release coating composition comprises: an aqueous dispersion (1) of one or more polysiloxanes (A), wherein the polysiloxanes (A) contain alkenyl groups and / or Q units represented by SiO4 / 2; an aqueous dispersion (2) of polysiloxanes (B), wherein the polysiloxanes (B) have hydrogen atoms directly bonded to Si atoms represented by Si-H groups; a crosslinking reaction inhibitor; a platinum catalyst; and a nonionic emulsifier; wherein the total amount of the solids component of the polysiloxanes (A) and the solids component of the polysiloxanes (B) in the release coating composition is 70% by mass or more; When the total content of the aforementioned polysiloxane (A) and the aforementioned polysiloxane (B) is set to 100 parts by mass, the content of the aforementioned polysiloxane (B) is 3 parts by mass or more to 45 parts by mass or less; relative to the mass of the aforementioned aqueous coating composition, the content of the aforementioned crosslinking reaction inhibitor is 5 ppm or more to 1000 ppm or less; the amount of the aforementioned platinum-based catalyst is 100 parts by mass relative to the total amount of the aforementioned aqueous dispersion (1) and the aforementioned aqueous dispersion (2), and the platinum element mass is 10 ppm or more to 800 ppm or less; the aforementioned nonionic emulsifier is used in the range of 0.1% by mass or more to 20% by mass relative to the total solids content; the number average molecular weight of the aforementioned polysiloxane A is 150,000 or more; the content of Si atoms contained in the aforementioned Q unit is in the range of 0.05 mol% or more to 60 mol% or less. Furthermore, the residual adhesion rate of the aforementioned polysiloxane release polyester film obtained by the following method is 90% or more: The peel strength of the polyester adhesive tape (manufactured by Nitto Denko, No. 31B) after being attached to a cold-rolled stainless steel sheet (SUS304) as specified in JIS G4305 is measured as the basic adhesion force (f0). The aforementioned polyester adhesive tape is pressed onto the release layer surface of the aforementioned polysiloxane release polyester film using a 5kg pressing roller. After maintaining the pressure for 30 seconds, the aforementioned polyester adhesive tape is peeled off. The peel strength of the aforementioned polyester adhesive tape after being attached to the aforementioned stainless steel sheet is measured as the residual adhesion force (f). The residual adhesion rate is calculated using the following formula based on the obtained basic adhesion force (f0) and the aforementioned residual adhesion force (f): Residual adhesion rate (%) = (f) / (f0) × 100 Here, the peel angle is set to 180 degrees and the peel speed is set to 300 mm / min.

7. The method for manufacturing a polysiloxane release polyester film as described in claim 6, wherein the aforementioned crosslinking reaction inhibitor is a crosslinking reaction inhibitor having an alkyne group.

8. A method for manufacturing a polysiloxane release polyester film as described in claim 6 or 7, wherein the alkenyl group of the aforementioned polysiloxane (A) is vinyl.