JP2015027735A - Mold release polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold release polyester film which is a release film required during adhesive processing, causes no process contamination and no adhesive contamination and has excellent foreign material inspection performance.SOLUTION: There is provided a mold release polyester film which has a layer obtained by applying a coating liquid containing a quaternary ammonium salt-containing polymer, a polyethylene glycol-containing acrylate polymer and a crosslinking agent on both surfaces of a polyester film and is a release film which has a coating layer having a thickness of 10 to 100 nm formed by applying a coating liquid containing at least one organosiloxane compound on any one of the layer and has a release layer on the coating layer, wherein the inclination of the orientation principal axis (orientation angle) of the release film is 12 degrees or less.

Description

  The present invention relates to a release polyester film having excellent oligomer sealing performance and foreign substance inspection properties at the same time.

  The technologies of flat panel display, organic EL, touch panel and electronic paper are becoming general-purpose technologies. Among the items described, there is still a pressure-sensitive adhesive technology that bonds members together, but the demand for this pressure-sensitive adhesive continues to grow. From this, the demand for release films that may be used during adhesive processing has the potential to grow as well.

  As necessary properties for release films used for adhesive processing, processing properties such as releasability and handling properties are of course important, but in recent years, other foreign matter inspection properties and process contamination sealing properties are important. The characteristics for improving the quality and the processing yield are also important. Among them, a sealing function related to process contamination sealing properties, for example, a base material component scattering sealing performance, an AS performance that does not attract foreign substances, is cited as a demand for separators used in matured adhesive technology. .

  In conventional release films, especially release polyester films, due to rolls existing in the process, especially metal rolls, heating rolls, scratches entering when passing, temperature, and heat applied during adhesive processing, A polyester film base material component (here, an oligomer, which may be abbreviated as OL hereinafter) may be generated, which may cause process contamination. For the same reason, the generated OL is mixed into the adhesive, and when the final product is viewed, the OL crystallizes and becomes a bright spot.

  Examples of the existing technology for suppressing the generation of OL in the release polyester film include the use of a polyester raw material with a small amount of OL and the provision of an OL sealing layer (Patent Documents 1 and 2). However, in the former case, the efficacy may be insufficient, and in the latter case, there is a problem that the silicone film cannot be formed well during the final silicone processing due to a small amount of transfer of the components of the OL sealing layer.

  That is, in the release polyester film technology, there is a demand for OL sealing layer application technology for stably coating the silicone release layer.

Japanese Patent No. 5281595 JP 2012-179870 published

  The present invention has been made in view of the above circumstances, and its solution is a release film required at the time of adhesive processing, which does not cause adhesive process contamination, adhesive contamination, and foreign matter inspectability. It is providing the release polyester film which is excellent in.

  As a result of intensive studies in view of the above circumstances, the present inventor has found that the above problem can be easily solved by a polyester film having a specific configuration, and has completed the present invention.

  That is, the gist of the present invention is to have a layer obtained by applying a coating solution containing a quaternary ammonium base-containing polymer, a polyethylene glycol-containing acrylate polymer, and a crosslinking agent on both sides of the polyester film. A mold release having a coating layer with a thickness of 10 to 100 nm formed by applying a coating agent containing at least one organosiloxane compound on one of the layers, and having a release layer on the coating layer The release polyester film is characterized in that the main film has an inclination (orientation angle) of 12 degrees or less.

  According to the present invention, it is possible to provide a release polyester film that can improve pressure-sensitive adhesive production, prevent pressure-sensitive adhesive process contamination, increase the pressure-sensitive adhesive processing yield, and have excellent foreign matter inspection properties. Because it can, its industrial value is high.

Schematic explanatory diagram of the composition of the film of the present invention

  The polyester film constituting the polyester film of the present invention may have a single layer structure or a multilayer structure. However, if considering the application to a further OL sealing function and other highly functional polyester films For example, it is preferable to have two layers, three layers, four layers or more.

  The polyester used in the present invention is preferably a homopolyester as a result of pursuing reduction of production costs and ease of process work. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Typical polyester includes polyethylene terephthalate and the like.

  In the film of the present invention, it is preferable to blend particles mainly for the purpose of imparting slipperiness and preventing the occurrence of scratches in each step. The kind of the particle to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness. Specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and phosphoric acid. Examples of the particles include magnesium, kaolin, aluminum oxide, and titanium oxide. Further, heat-resistant organic particles as described in JP-B-59-5216, JP-A-59-217755 and the like may be used. Examples of other heat-resistant organic particles include thermosetting urea resins, thermosetting phenol resins, thermosetting epoxy resins, benzoguanamine resins, and the like. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.

  On the other hand, the shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc. These series of particles may be used in combination of two or more as required.

  Moreover, the average particle diameter of the particle | grains to be used is 0.01-3 micrometers normally, Preferably it is the range of 0.1-2 micrometers. When the average particle size is less than 0.01 μm, the slipperiness may not be sufficiently imparted. On the other hand, when the thickness exceeds 3 μm, transparency may be lowered due to the aggregation of the particles at the time of film formation, and breakage or the like is likely to occur, resulting in a problem in productivity.

  Furthermore, the content of particles in the polyester is usually in the range of 0.001 to 5% by weight, preferably 0.005 to 3% by weight. When the particle content is less than 0.001% by weight, the slipperiness of the film may be insufficient. On the other hand, when the content exceeds 5% by weight, the transparency of the film is insufficient. It may become.

  The method for adding particles to the polyester layer is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage for producing the polyester constituting each layer, but it is preferably added after completion of esterification or transesterification.

  Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a blending of dried particles and a polyester raw material using a kneading extruder. It is done by methods.

  In addition, in the polyester film in the present invention, conventionally known antioxidants, antistatic agents, and heat stabilizers as necessary in addition to the above particles, as long as they do not affect the inhibition of the curing reaction to the silicone release layer. , Lubricants, dyes, pigments and the like can be added.

  Although the thickness of the polyester film in this invention will not be specifically limited if it can be formed into a film as a film, Usually, 10-350 micrometers, Preferably it is the range of 50-250 micrometers.

  Next, although the manufacture example of the polyester film in this invention is demonstrated concretely, it is not limited to the following manufacture examples at all. That is, a method of using the polyester raw material described above and cooling and solidifying a molten sheet extruded from a die with a cooling roll to obtain an unstretched sheet is preferable. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method and / or a liquid application adhesion method is preferably employed. Next, the obtained unstretched sheet is stretched in the biaxial direction. In that case, first, the unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is usually 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is usually 2.5 to 7.0 times, preferably 3.0 to 6.0 times. Next, the film is stretched in the direction perpendicular to the first stretching direction. In that case, the stretching temperature is usually 70 to 170 ° C., and the stretching ratio is usually 3.0 to 7.0 times, preferably 3.5 to 6 times. .0 times. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% to obtain a biaxially oriented film. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

  For the production of the polyester film of the present invention, a simultaneous biaxial stretching method can also be employed. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is usually stretched and oriented in the machine direction and the width direction at a temperature controlled normally at 70 to 120 ° C., preferably 80 to 110 ° C. Is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or under relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, the formation of a layer constituting the polyester film in the present invention (which is a layer adjacent to the polyester base material and may simply be abbreviated as A, A ′ layer hereinafter) will be described. Regarding the A layer, it may be provided by in-line coating, which treats the film surface during the stretching process of the polyester film, or may be applied off-system on the film once produced, or may be used together. May be. In-line coating is preferably used in that it can be applied at the same time as film formation, so that it can be manufactured at low cost, and the thickness of the A and A ′ layers can be changed by the draw ratio.

  The in-line coating is not limited to the following, but for example, in the sequential biaxial stretching, the coating treatment can be performed particularly before the lateral stretching after the longitudinal stretching is finished. When a coating layer is provided on a polyester film by in-line coating, coating can be performed simultaneously with film formation, and the coating layer can be processed at a high temperature, and a film suitable as a polyester film can be produced.

  In the present invention, the A and A ′ layers are required to use a coating solution containing a quaternary ammonium base-containing polymer for the purpose of preventing the oligomer component from entering the pressure-sensitive adhesive layer. Is.

  Regarding the quaternary ammonium base-containing polymer used in the present invention, those having a constituent element containing a quaternary ammonium base in the main chain or side chain in the molecule are targeted. Specific examples include pyrrolidinium ring, quaternized alkylamine, copolymerized with acrylic acid or methacrylic acid, quaternized N-alkylaminoacrylamide, vinylbenzyltrimethylammonium salt, 2-hydroxy-3- And methacryloxypropyltrimethylammonium salt. Furthermore, these may be combined or copolymerized with other binder polymers. Examples of the anion that serves as a counter ion for these quaternary ammonium salts include ions such as halogen, alkyl sulfate, alkyl sulfonate, and nitric acid. Among these, counter ions other than halogen are preferable for the use of the present invention in that heat resistance is particularly good.

  Further, regarding the molecular weight of the quaternary ammonium base-containing polymer, if the molecular weight is too low, it may be easily removed from the coating layer and the performance may deteriorate over time, or problems such as blocking of the coating layer may occur. Moreover, when the molecular weight is low, the heat stability tends to be inferior.

  From this viewpoint, the number average molecular weight of the quaternary ammonium base-containing polymer is usually 1000 or more, preferably 2000 or more, and more preferably 5000 or more. On the other hand, when the number average molecular weight is too high, problems such as excessive increase in the viscosity of the coating solution may occur. Therefore, the upper limit of the number average molecular weight is preferably 500,000 or less. Moreover, these compounds may be used independently and may be used in combination of 2 or more types.

  The blending amount of the quaternary ammonium base-containing polymer in the A and A ′ layers is preferably in the range of 20 to 70% by weight, more preferably in the range of 40 to 70% by weight. If it is out of the range, it may be difficult to obtain a desired oligomer sealing effect.

  In the present invention, it is essential to contain a polyethylene glycol-containing acrylate polymer in the coating solution for the purpose of improving the stretch followability when forming the A and A ′ layers. Specifically, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene glycol diacrylate (the polymerization degree of polyethylene glycol units is preferably in the range of 4 to 14), polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, poly ( Ethylene glycol-tetramethylene glycol) diacrylate, poly (propylene glycol-tetramethylene glycol) diacrylate, polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate, polypropylene glycol-polybutylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, methoxypolyethylene Glycol monoacrelan , Octoxy polyethylene glycol-polypropylene glycol monomethacrylate, Octoxy polyethylene glycol-polypropylene glycol monoacrylate, Lauroxy polyethylene glycol monomethacrylate, Lauroxy polyethylene glycol monoacrylate, Stearoxy polyethylene glycol monomethacrylate, Stearoxy polyethylene glycol monoacrylate, Ali Examples include polymers starting from loxypolyethylene glycol monomethacrylate, allyloxypolyethylene glycol monoacrylate, and the like.

  The number average molecular weight of the polyethylene glycol-containing acrylate polymer used in the present invention is usually 1000 or more, preferably 2000 or more, more preferably 5000 or more. On the other hand, when the number average molecular weight is too high, problems such as the viscosity of the coating solution becoming too high may occur. From this point of view, the upper limit of the number average molecular weight is preferably 500,000 or less. Moreover, these compounds may be used independently and may be used in combination of 2 or more types.

  In the present invention, a polyethylene glycol-containing alkyl acrylate polymer is preferably used in combination in order to further improve stretchability. The chain length of the alkyl chain is not particularly limited as long as it is in a range that can be polymerized as a polymer. The content of the polyethylene glycol-containing alkyl acrylate polymer constituting the coating layer (A, A ') in the present invention is preferably in the range of 5 to 40% by weight in order to improve stretchability. When it is out of the range, problems such as insufficient stretching followability at the time of forming the coating layer (A, A ′) may occur.

  Regarding the A layer constituting the polyester film of the present invention, the quaternary ammonium base-containing polymer and the polyethylene glycol-containing acrylate polymer to be used may be a mixture or may be copolymerized in advance, which impairs the gist of the present invention. The range is not particularly limited. Moreover, when making it copolymerize, a conventionally well-known manufacturing method can be used.

  In the present invention, it is necessary to use a crosslinking agent in combination as a coating solution for the purpose of further improving the durability of the A layer. Specific examples include methylolated or alkylolized urea, melamine, guanamine, oxazoline, epoxy compound, acrylamide, polyamide compound, epoxy compound, aziridine compound, isocyanate compound, titanium coupling agent, zirco-aluminate coupling agent, poly Examples thereof include carbodiimide.

  Among the cross-linking agents, melamine cross-linking agents are preferable in terms of good coating properties and durable adhesion particularly in the use of the present invention. The melamine crosslinking agent is not particularly limited, but melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting methylolated melamine with a lower alcohol, And a mixture thereof can be used.

  The melamine crosslinking agent may be either a monomer or a condensate composed of a dimer or higher multimer, or a mixture thereof. As the lower alcohol used for the etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be preferably used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and an imino group type methylated melamine, a methylol group type melamine, or a methylol group type methylation. Melamine, fully alkyl methylated melamine and the like can be used. Of these, methylolated melamine is most preferred. Furthermore, for the purpose of promoting thermal curing of the melamine crosslinking agent, for example, an acidic catalyst such as p-toluenesulfonic acid can be used in combination.

  The oxazoline crosslinking agent used in the present invention is a compound having an oxazoline ring in the molecule, and includes a monomer having an oxazoline ring and a polymer synthesized using an oxazoline compound as one of raw material monomers.

  The isocyanate compound used in the present invention refers to a compound having an isocyanate group in the molecule, specifically, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, naphthalene diisocyanate, tolylene diene. Examples thereof include isocyanates, polymers and derivatives thereof.

  As an epoxy compound used by this invention, the compound containing an epoxy group in a molecule | numerator, its prepolymer, and hardened | cured material are mentioned, for example. A typical example is a condensate of epichlorohydrin and bisphenol A. In particular, a reaction product of a low molecular polyol with epichlorohydrin gives an epoxy resin having excellent water solubility.

  These cross-linking agents may be used alone or in combination of two or more. Furthermore, when consideration is given to application to in-line coating, it is preferable to have water solubility or water dispersibility.

  In the present invention, it is also possible to use a binder polymer in the coating layer as long as the gist of the present invention is not impaired.

  The “binder polymer” used in the present invention is a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) according to a polymer compound safety evaluation flow scheme (sponsored by the Chemical Substance Council in November 1985). ) Is a polymer compound having a molecular weight of 1000 or more and having a film-forming property.

  Specific examples of the binder polymer include polyester resin, acrylic resin, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, etc.), polyurethane resin, polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starch. And the like.

  Analysis of the components in the coating solution for forming the A layer can be performed by surface analysis such as TOF-SIMS.

  When providing a coating layer by in-line coating, the above-mentioned series of compounds is applied as an aqueous solution or dispersion, and the coating solution adjusted to a solid content concentration of about 0.1 to 50% by weight as a guide is applied onto the polyester film. It is preferable to produce a laminated polyester film. Moreover, in the range which does not impair the main point of this invention, a small amount of organic solvents may be contained in the coating liquid for the purpose of improving dispersibility in water, improving film-forming properties, and the like. Only one type of organic solvent may be used, or two or more types may be used as appropriate.

Regarding the A layer (12 in FIG. 1) of the polyester film of the present invention, the thickness of the coating layer provided on the polyester film is usually 0.002 to 1.0 g / m ² , more preferably 0.005 to 0.00. 5 g / ^{m 2,} more preferably in the range of 0.01~0.2g / ^{m 2.} When the film thickness is less than 0.002 g / m ^2, sufficient adhesion cannot be obtained, and when it exceeds 1.0 g / m ² , the appearance, transparency, and film blocking properties are deteriorated.

Moreover, regarding the A ′ layer (12 ′ in FIG. 1) opposite to the release layer surface of the polyester film of the present invention, the thickness of the coating layer provided on the polyester film is usually 0.05 to 0.15 g / m. ² and more preferably in the range of 0.07 to 0.12 g / m ² . That is, the specific film thickness of the coating layer is preferably controlled in the range of 40 to 100 nm, more preferably in the range of 60 to 80 nm. If the film thickness is less than 40 nm, sufficient OL sealing properties cannot be obtained, and scratches may occur with the rolls in the process, and when heat is generated, a problem occurs in which OL is precipitated, If it exceeds 100 nm, the cost increases.

  In the polyester film of the present invention, examples of the method for providing the A and A ′ layers include conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating. Regarding the coating method, there is a description example in “Coating method” published by Yasuharu Harasaki in 1979.

  In the present invention, the drying and curing conditions for forming the A and A ′ layers on the polyester film are not particularly limited. For example, when an application layer is provided by off-line coating, usually 80 to 200 ° C. The heat treatment may be performed for 3 to 40 seconds, preferably 100 to 180 ° C. for 3 to 40 seconds.

  On the other hand, when the A and A ′ layers are provided by in-line coating, it is usually preferable to perform heat treatment at 70 to 280 ° C. for 3 to 200 seconds as a guide.

  Further, irrespective of off-line coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as required. The polyester film constituting the laminated polyester film in the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

  Next, formation of a coating layer (hereinafter sometimes simply referred to as B layer) to be laminated on the A layer will be described. Regarding the B layer, the above-described coating stretching method (in-line coating) may be used, or a so-called off-line coating that is applied outside the system on the polyester film having the above-described coating layer once manufactured may be employed. A technique may be adopted.

  The example of the organosiloxane compound mix | blended in the coating agent used in order to form B layer in this invention is shown below. Various substituents of the organosiloxane of the following formula are variously changed.

(R ¹ ) (R ³ ) ₂ Si— (O—Si (R ¹ ) (R ³ )) n- (O—Si (R ² ) (R ³ )) m—R ^{3 wherein} R ¹ and R ² is each independently an organic group containing an epoxy group such as a γ-glycidoxypropyl group or a 3,4-epoxycyclohexylethyl group, or an alkoxy group such as a methoxy group or an ethoxy group. , R ³ is an alkoxy group such as a methoxy group or an ethoxy group, or a group represented by the following formula.

—O—Si (R ³ ) ₂ (R ⁴ )
In the above formula, R ⁴ is the same epoxy group-containing organic group or alkoxy group as the R ¹ group or R ² group. Specific examples of the organosiloxane include γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 5 , 6-epoxyhexyltriethoxysilane, tetraethoxysilane, metolaethoxysilane, and other monomers, and hydrolyzable organisms of these monomers or mixtures of these monomers.

  The organic solvent that dissolves the B layer forming material preferably contains at least one alcohol solvent selected from ethanol, propanol, i-propanol, butanol, i-butanol, t-butanol, pentanol, and the like.

  Further, inorganic particles may be contained for the purpose of improving the adhesion and slipperiness of the B layer, and specific examples include silica, alumina, kaolin, calcium carbonate, titanium oxide, barium salt and the like.

  Moreover, if it is a material that has a low influence on the curing reaction inhibition of the release layer, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, organic polymer particles, an antioxidant, An ultraviolet absorbent foaming agent, a dye and the like may be contained.

  In the range not exceeding the gist of the present invention, only one type of organic solvent may be used for the purpose of improving dispersibility, improving film forming property, etc., and two or more types may be used as appropriate.

  In this invention, the application quantity (after drying) of B layer is 10-100 nm normally, Preferably it is the range of 20-100 nm. When the coating amount is less than 10 nm, the uniformity of the coating thickness may be insufficient, and the amount of OL deposited from the surface of the B layer after heat treatment increases. On the other hand, if the thickness exceeds 100 nm, the coating film is brittle even if it has OL sealing performance, and scratches are likely to occur in the drying process and then the winding process after coating, and the film appearance tends to become cloudy.

  In the present invention, as a method of providing the B layer, a conventionally known coating method such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating or the like can be used. As for the coating method, there is a description example in “Coating method” published by Yoji Harasaki in 1979.

  In the present invention, the curing conditions for forming the B layer on the polyester film are usually heat-treated at 120 ° C. or higher, preferably 120 to 200 ° C. for 3 to 40 seconds, more preferably 120 to 160 ° C. 3 Heat treatment is performed for approximately 40 seconds. When the heat treatment is not performed at 120 ° C. or higher, the coating film formation is incomplete and the amount of OL deposited increases.

  In the present invention, OL (oligomer) is defined as a cyclic trimer among low molecular weight substances that crystallize and precipitate on the film surface after heat treatment.

  In the present invention, the A layer and the B layer have OL sealing performance independently, but by combining them, the adhesive interaction in the film, or the configuration of compensating for the gap between each other is taken, and either of the films The OL sealing performance can be obtained more efficiently than the same thickness (A + B thickness). In addition, even if only the B layer is applied to a certain extent so as to exceed 100 nm, a desired OL sealing performance can be imparted. When silicone coating (C layer) is formed, it causes curing inhibition. The technical key of this patent is that the combination of the A and B layers and the thickness are important, and it is considered that a synergistic effect is brought about in the OL sealing performance.

  The release layer (C layer) provided on the coating layer B layer in the present invention is not particularly limited as long as it contains a material having releasability. Among them, the one containing a curable silicone resin is preferable because the releasability is improved. A type having a curable silicone resin as a main component may be used, or a modified silicone type by graft polymerization with an organic resin such as a urethane resin, an epoxy resin, or an alkyd resin may be used.

  As the type of the curable silicone resin, any of the curing reaction types such as an addition type, a condensation type, an ultraviolet ray curable type, an electron beam curable type, and a solventless type can be used.

  Specific examples of the curable silicone resin include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2242, X-manufactured by Shin-Etsu Chemical Co., Ltd. 62-2461, X-62-5039, X-92-184, X-92-185, KS-3800, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205 manufactured by Dow Corning Asia Co., Ltd. DKQ3-210, Toshiba Silicone Co., Ltd. YSR-3022, TPR-6700, TPR-6720, TPR-6721, Toray Dow Corning Co., Ltd. SD7220, SD7226, SD7229, LTC303E, LTC856, LTC755, LTC754, SRX212 etc. are mentioned. Further, a release control agent may be used in combination to adjust the release property of the release layer. Further, as described above, a silane compound having an amino group may be added to the release layer.

In the present invention, as a method for providing a release layer on the polyester film, a conventionally known coating method such as reverse roll coating, gravure coating, bar coating, doctor blade coating, or the like can be used. The application amount of the release layer in the present invention is usually in the range of 0.01 to 1.0 g / m ² .

  In the present invention, a coating layer such as an adhesive layer, an antistatic layer and an oligomer precipitation preventing layer may be provided on the surface where the release layer is not provided, and the polyester film may be subjected to corona treatment, plasma treatment, etc. A surface treatment may be applied.

  Moreover, drying and / or curing (thermal curing, ionizing radiation curing, etc.) of the coating film of the pressure-sensitive adhesive layer or the release layer can be performed individually or simultaneously. When performing simultaneously, it is preferable to carry out at the temperature of 80 degreeC or more. The drying and curing conditions are preferably 80 ° C. or higher and 10 seconds or longer. If the drying temperature is less than 80 ° C. or the curing time is less than 10 seconds, the coating film is incompletely cured, and the coating film tends to fall off.

  In order to make the coated layer of the polyester film of the present invention clean and strong, it is preferable to use a transition metal catalyst. The content of the transition metal catalyst in the coating layer is usually 1.0 to 5.0% by weight, preferably 3.0 to 4.0% by weight. When the content of the transition metal catalyst in the coating layer is lower than 1.0% by weight, the components containing excess electrons contained in the A and B layers installed for the purpose of OL sealing, Since the curing reaction is inhibited, the adhesiveness of the coating film is lowered, the peeling force is defective, and the curing reaction in the coating layer is insufficient. The key of this patent can be achieved by intensive adjustment of the content of the transition metal catalyst in the coating layer, but as a synergistic effect, it succeeded in improving the coating film adhesion. On the other hand, when the content of the transition metal catalyst in the coating layer exceeds 5.0% by weight, it may be costly and may cause process defects such as increased reactivity and generation of gel foreign matter. .

In the release polyester film that was kept for one day after the production of the present invention, 3 ml of 1-butanol solution in which 5% by weight of potassium hydroxide was dissolved in a vial (20 mL) was added in order to ensure peeling stability over time. Furthermore, after immersing the release film (40 cm ² ) and heat-treating the vial (20 mL) at 50 ° C. for 1 hour, the amount of hydrogen (H ₂ ) gas generated from the release film can be suppressed to 60 ppm or less. More preferably, it is 40 ppm or less. When the amount of hydrogen (H ₂ ) gas generated from the release film exceeds 60 ppm, when the adhesive layer and the release layer of the release film are pasted together for a long period of time, the variation in peeling over time is large. In a scene that originally needs to be peeled off, there may be problems such as difficulty in peeling.

In the release film of the present invention, as a specific method for suppressing the hydrogen (H ₂ ) gas generation amount to 60 ppm or less, for example, for the purpose of adjusting the release of the release layer, a silicone resin having a small amount of functional groups is used. When using a release control agent in combination, select a type with a small amount of Si-H group derived from the crosslinking agent, heating during processing, or adjusting the amount of catalyst arbitrarily to eliminate insufficient curing, etc. This method is exemplified.

  Conventionally, a person skilled in the art commonly uses a method of adding a large amount of a crosslinking agent for the purpose of increasing the amount of Si-H groups derived from a crosslinking agent, as a method for increasing the peeling force. It is done. However, in this method, as the amount of Si—H groups derived from the crosslinking agent decreases with time due to the influence of moisture absorption or the like, the variation in peeling increases. For this reason, when the release film and the pressure-sensitive adhesive layer are stored in a state of being bonded together for a long time after the application of the pressure-sensitive adhesive, problems such as heavy release occur when the release film is peeled.

After heat-treating the release surface of the polyester film of the present invention (180 ° C., 10 minutes), the amount of OL extracted from the surface of layer C with dimethylformamide is preferably 0.2 mg / m ² or less, more preferably Is 0.1 mg / m ² or less, particularly preferably 0.01 mg / m ² or less. When OL exceeds 0.2 mg / m ² , for example, OL is generated during heating in the adhesion process, or during heating in the ITO crystallization process, and the transparency of the adhesive is decreased, the adhesive strength of the adhesive layer is decreased, Problems such as causing trouble in the visual inspection process and causing process contamination may occur.

After heat treatment (180 ° C., 10 minutes) on the releasable surface (12 ′: A ′ layer shown in FIG. 1) of the polyester film of the present invention, the amount of OL extracted from the surface of the A ′ layer with dimethylformamide is 1. It is preferably 0 mg / m ² or less, more preferably 0.8 mg / m ² or less. When OL exceeds 1.0 mg / m ² , for example, OL occurs during heating in the adhesion process, when passing through a heating roll, or during heating in the ITO crystallization process, causing problems such as causing process contamination. Sometimes.

  In the present invention, the roughness (Sa) of the C layer surface is preferably 10 nm or less. At this time, since the surface roughness of the C layer does not contain particles in the C layer and is a thin layer, it may be considered that the surface roughness of the B layer is directly reflected. When the surface roughness exceeds 10 nm, the OL sealing performance decreases. Furthermore, in order to exhibit sealing performance, Sa is preferably 8 nm or less. As a method of controlling this Sa, it is important that clusters (aggregates) are not generated as much as possible with the coating liquid before coating. As a result of the examination, it was found that the Sa can be controlled when the solution haze in the coating material for the B layer is usually 1.0% or less, preferably 0.5% or less.

  The orientation angle of the release polyester film of the present invention is usually 12 degrees or less, preferably 9 degrees or less, more preferably 6 degrees or less. When the orientation angle is larger than 12 degrees, in the optical inspection, the light interference color becomes easy to see, and there arises a problem that the foreign matter inspection becomes difficult.

  Means for satisfying the range of the inclination (orientation angle) of the orientation principal axis of the release polyester film of the present invention is such that the stretching ratio is not reduced, and the stretching temperature is set as a stretching condition during film formation. It is to devise.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measurement method and evaluation method used in the present invention are as follows.

(1) Measurement of intrinsic viscosity of polyester 1 g of polyester from which other polymer components and pigments incompatible with polyester have been removed are precisely weighed, and 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) is added. It was dissolved and measured at 30 ° C.

(2) Measurement of average particle size (d50: μm) 50% integrated (weight basis) in equivalent spherical distribution measured using centrifugal sedimentation type particle size distribution measuring device (SA-CP3 type manufactured by Shimadzu Corporation) The value was defined as the average particle size.

(3) Measurement of solution haze of coating solution Using a Nippon Denshoku haze meter NDH-300A, the coating solution was put into a quartz cell and measured by a transmission method. An average value of three measurements was adopted.

(4) Coat thickness of coating layers (A), (A ′) and (B) A cross section of the release polyester film was cut out by a freezing ultrathin section method, and manufactured by Hitachi, Ltd. by a stained ultrathin section method by RuO ₄ staining. Using a transmission electron microscope H-7100FA, the laminated film portion was observed and photographed at an acceleration voltage of 100 kV. The thickness of the laminated film was measured from the cross-sectional photograph.

(5) Evaluation of peeling force (F) on the C layer surface side After pasting one side of a double-sided adhesive tape (“No. 502” manufactured by Nitto Denko) on the surface of the release layer of the sample film, cut into a size of 50 mm × 300 mm After that, the peel strength after standing for 1 hour at room temperature is measured. For the peeling force, a tensile tester (“Intesco model 2001 type” manufactured by Intesco Co., Ltd.) was used, and 180 ° peeling was performed under the condition of a tensile speed of 300 mm / min. The peeling force (F) on the C layer surface side is represented by gf / 50 mm.

(6) Quantification of amount of hydrogen (H ₂ ) gas generated after heat treatment on the C layer surface side A sample film of 40 cm ² is cut out and weighed in advance with respect to the release polyester film placed for 1 day after the production. Again cut out amount to be used for measuring the ^second corner 5 mm, (corresponding to about 0.213g in release film 38 [mu] m) of gas chromatography dedicated 20ml vial filling sample film. Next, 3 ml of a butanol solution in which 5% by weight of potassium hydroxide is dissolved (prepared by adding 1 g of potassium hydroxide to 19 g of butanol) is sampled with a pipetter, and the entire sample film is immersed in a 5% by weight of potassium hydroxide butanol solution. Add as follows. Thereafter, the vial is sealed using a crimper, and heat-treated at 50 ° C. for 1 hour using a heating block (model: HF21, manufactured by Yamato Kagaku). Thereafter, the amount of hydrogen (H ₂ ) gas generated from the sample film is quantitatively analyzed using the following gas chromatography measuring device, and judged according to the following criteria.

<< Gas chromatography measurement conditions >>
Equipment: EAGanalyzer (SENSORTEC Co, Ltd)
Measurement conditions: pressure Gauge Low: 0.05 MPa; High: 0.05 MPa
Column temperature: 50 ° C
Column flow rate: 30.0sccm
Syringe injection volume: 1cc
Measurement time: 5 min

<Criteria>
○: 60 ppm or less (practical level)
X: Over 60 ppm (practical level)

(7) Release property on the C layer surface side The release property was evaluated from the situation when the release film was peeled off from the laminated film having the adhesive layer. Judgment is based on the following criteria.
<Criteria>
○: The release film is peeled off cleanly, and the phenomenon that the adhesive adheres to the release layer is not observed. Δ: The release film peels off, but the adhesive adheres to the release layer when peeled off at a high speed. : Adhesive adheres to the release film

(8) Coating layer adhesion on C layer surface side The release film was rubbed with a finger three times, and then a tape was applied to the rubbed portion to evaluate whether there was a catch when the tape was peeled off. Judgment is based on the following criteria.
<Criteria>
○: As with the case before rubbing with a finger, it does not feel a catch when the tape is peeled.

(9) Measurement of orientation (orientation angle) of orientation main axis of release polyester film Using a polarizing microscope manufactured by Carl Zeiss, the orientation of the polyester film is observed, and the orientation of the main orientation axis in the polyester film plane is that of the polyester film. The number of tilts with respect to the width direction was measured to determine the orientation angle. This measurement was carried out at a total of three locations on the center and both ends of the film, and the largest orientation angle value among the three locations was taken as the maximum orientation angle. Judgment is based on the following criteria.
<Criteria>
○: 12 degrees or less ×: Greater than 12 degrees

(10) Measurement of transmittance of release polyester film According to JIS-K7105, the total light transmittance of the release polyester film was measured with an integrating sphere turbidimeter NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd.

(11) Haze (turbidity) measurement of release polyester film The total light transmittance of the release polyester film was measured with an integrating sphere turbidimeter NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS-K7105.

(12) Measurement of heat-shrinkage rate of release polyester film For the release polyester film, the shrinkage rate in the film running direction is SMD and the shrinkage rate in the width direction perpendicular to the transverse film running direction is STD. cm). Subsequently, the sample is heated in an oven at 150 ° C. for 30 minutes, and the sample is taken out of the oven and the length l (cm) is measured. This operation is performed three times, and the average value is adopted as the value of the heat shrinkage rate. The heat shrinkage rate can be calculated by the following formula.
Heat shrinkage (%) = S = {(L−l) / L} × 100

(13) OL measurement extracted from the surface of C layer (14 in FIG. 1) and A ′ layer (12 ′ in FIG. 1) The unheated release film is heated in air at 180 ° C. for 10 minutes in advance. After that, the heat-treated film is brought into close contact with the inner surface of a box having a top and width of 10 cm and a height of 3 cm, and the box shape is obtained. Next, 4 ml of DMF (dimethylformamide) is placed in the box prepared by the above method and left for 3 minutes, and then DMF is recovered. The recovered DMF was supplied to liquid chromatography (manufactured by Shimadzu Corporation: LC-7A) to determine the amount of OL in DMF, and this value was divided by the area of the film in contact with DMF to obtain the amount of film surface OL (mg / M ² ).

  The amount of oligomer in DMF was determined from the peak area ratio between the standard sample peak area and the measured sample peak area (absolute calibration curve method). The standard sample was prepared by accurately weighing OL (cyclic trimer) collected in advance and dissolving it in DMF accurately weighed. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg / ml. The conditions for the liquid chromatograph were as follows.

Mobile phase A: Acetonitrile Mobile phase B: 2% acetic acid aqueous solution Column: “MCI GEL ODS 1HU” manufactured by Mitsubishi Chemical Corporation
Column temperature: 40 ° C
Flow rate: 1 ml / min Detection wavelength: 254 nm
The quality of the surface OL is judged based on the following criteria.

<Criteria>
For C layer ○: from low values ^{0.15mg / m 2 △: 0.15~0.20mg /} m 2
×: 0.20mg / ^{m 2} than the value for the high A 'layer ○: from low values ^{0.8mg / m 2 △: 0.8~1.0g /} m 2
X: Value higher than 1.0 mg / m ²

(14) C layer surface side surface roughness measurement Using AFM Nano-R manufactured by Toyo Technica, a coating solution was applied to a polyester film and dried to obtain a measurement sample. In the contact mode, the surface roughness Sa (nm) was measured in a measurement range of 5 μm × 5 μm. Three average values were used.

(15) Appearance and appearance evaluation of release film The appearance defects due to the thickness of the coating film were evaluated. Evaluation was performed according to the following criteria. Judgment is based on the following criteria.
<Criteria>
○: Transparent and beautiful △: Slightly whitish ×: Cloudy white

(16) Foreign matter inspection (visual)
A) It was evaluated whether transparency was maintained and foreign objects and scratches were easily found when inspected by a transmission and reflection method under a fluorescent lamp. In the observation, A4 size samples were cut out from a total of three locations in the center and both ends in the width direction of the obtained film.

B) Taking the polarizing plate inspection into consideration, the width direction of the release film obtained by applying a release agent on the film and having a dryer temperature of 120 ° C. and a line speed of 30 m / min is parallel to the alignment axis of the polarizing film. The release film was adhered to the polarizing film through an adhesive so that a polarizing plate was obtained. Here, when the polarizing plate was prepared, black metal powder (foreign matter) having a size of 50 μm or more was mixed between the pressure-sensitive adhesive and the polarizing film so as to be 50 / m ² . A polarizing plate for inspection is superimposed on the polarizing plate release film mixed with the foreign matter thus obtained so that the orientation axis is orthogonal to the width direction of the release film, and white light is irradiated from the polarizing plate side. Then, it was visually observed from a polarizing plate for inspection, and whether or not a foreign matter mixed between the adhesive and the polarizing film was found under crossed Nicols was evaluated according to the following criteria. In the observation, A4 size samples were cut out from a total of three locations in the center and both ends in the width direction of the obtained film. Judgment is based on the following criteria.

<Criteria>
○: Good foreign object recognition △: Foreign object can be recognized with relatively no problem.
×: Foreign matter recognition poor ○ and Δ are at a level where there is no problem in actual use.

(17) Release film formation, processing productivity When producing a polyester film, the film formation yield is evaluated from the film breakage and film formation characteristics under the stretching conditions. Further, in the subsequent B-layer and C-layer deposition, the processing yield including appearance and characteristics is evaluated. Judgment is based on the following criteria.
<Criteria>
○: Sufficient continuity can be secured (level that can be implemented and sold)
X: Sufficient continuity cannot be ensured (it is difficult to implement and costs do not match)

(18) Adhesive Processing Characteristics A) Adhesive Processing Step Roll Dirt In the pressure-sensitive adhesive step, the roll contamination of the heating roll and / or metal roll when using a release film quantitatively was evaluated. Judgment is based on the following criteria.
<Criteria>
○: Roll stain does not occur even if processed over 10,000m (practicable level)
X: Roll dirt occurs before processing 10,000 m (level at which implementation is difficult)

B) Adhesive processing step In the contaminated adhesive step, the degree of contamination in the adhesive drying step was evaluated when the release film was used quantitatively. Judgment is based on the following criteria.
<Criteria>
○ Contamination is not noticeable even after 1 week of production (practical level)
×: Whitish contamination occurs before production for 1 week (difficult to implement)

C) Pressure-sensitive adhesive processing productivity In the pressure-sensitive adhesive process, it was comprehensively evaluated whether the above-mentioned A) and B) were not satisfied, and the foreign matter inspection property was poor, resulting in defects. Judgment is based on the following criteria.
<Criteria>
○: Adhesive process is not contaminated and foreign matter inspection is good (practicable level)
X: There is pressure-sensitive adhesive process contamination, or the foreign matter inspection property is poor (level that is difficult to implement)

(19) Appropriate use of separator for polarizing plate member pressure-sensitive adhesive As a release film for polarizing plate pressure-sensitive adhesive, pressure-sensitive adhesive coating can be performed without any problem, and foreign matter can be recognized after the production of the product. Judgment is based on the following criteria.
<Criteria>
○: Appropriate for use and can be used ×: Not appropriate for use and difficult to use

(20) Appropriate Separator for General Optical Member Adhesive Use For general tapes and as a release film for new non-adhesive (particularly highly transparent type) adhesive coating can be performed without problems. Judgment is based on the following criteria.
<Criteria>
○: Appropriate for use and can be used ×: Not appropriate for use and difficult to use

The polyester used in the examples and comparative examples was prepared as follows.
<Method for producing polyester (a)>
Using 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol as starting materials, adding tetrabutoxy titanate as a catalyst to the reactor, setting the reaction start temperature to 150 ° C., and gradually increasing the reaction temperature as methanol is distilled off. It was 230 degreeC after 3 hours. After 4 hours, the transesterification reaction was substantially completed, and then a polycondensation reaction was performed for 4 hours.
That is, the temperature was gradually raised from 230 ° C. to 280 ° C. On the other hand, the pressure was gradually reduced from normal pressure, and finally 0.3 mmHg. After the start of the reaction, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.61 due to a change in the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure to obtain a polyester (a) having an intrinsic viscosity of 0.61.

<Method for producing polyester (b)>
In the production method of polyester (a), 0.2 part of silica particles having an average particle diameter of 2.0 μm dispersed in ethylene glycol was added, and the polycondensation reaction was stopped at a time corresponding to an intrinsic viscosity of 0.61. A polyester (b) having an intrinsic viscosity of 0.61 was obtained using a method similar to the method for producing polyester (a).

<Manufacture of polyester>
The mixed raw materials in which the polyesters (a) and (b) were mixed at a ratio of 77% and 23%, respectively, were used as the outermost layer (surface layer) raw material, and the polyester (a) was used as the intermediate layer raw material in each of the two extruders. 2 layers and 3 layers (surface layer / intermediate layer / surface layer) on a cooling roll which is extruded from a die and melted at 290 ° C. and then set to a surface temperature of 40 ° C. using an electrostatic application adhesion method. The composition was co-extruded and cooled and solidified to obtain an unstretched sheet. Next, the film was stretched 2.8 times in the machine direction at a film temperature of 100 ° C. using the roll peripheral speed difference, and then the coating amount (after drying) of the following coating agent was applied to one side of the machine film. Apply to 03 g / m ² (corresponds to 12 layers (A layer) shown in FIG. 1) and apply to the other surface so that the coating amount (after drying) is 0.07 g / m ² (Corresponding to the 12 ′ (A ′) layer shown in FIG. 1), led to a tenter, stretched 5.1 times at 120 ° C. in the transverse direction, heat-treated at 220 ° C. for 10 seconds, and then at 180 ° C. in the width direction A polyester film (I) having a width of 4500 mm, a thickness of the A layer of 38 μm (surface layer of 1.9 μm, intermediate layer of 34.2 μm) and an intrinsic viscosity of 0.61 was obtained.

In addition, the compound used in order to comprise A and A 'layer is as follows.
(Example compounds)
-Quaternary ammonium base-containing polymer (A1):
2-hydroxy-3-methacryloxypropyltrimethylammonium salt polymer Counter ion: methyl sulfonate Number average molecular weight: 30000
-Polyethylene glycol-containing acrylate polymer (B1):
Polyethylene glycol-containing monoacrylate polymer Number average molecular weight: 20000
-Polyethylene glycol-containing acrylate polymer (B2):
Octoxy polyethylene glycol-polypropylene glycol monoacrylate polymer Number average molecular weight: 32000

・ Crosslinking agent (C1): Melamine crosslinking agent (DIC Corporation: Becamine “MAS”)
・ Crosslinking agent (C2): Oxazoline crosslinking agent (Nippon Shokubai: Epocross “WS500”)
Particle (D1): Alumina surface modified colloidal silica (average particle size: 50 nm)
Particle (D2): colloidal silica (average particle diameter: 70 nm)
The following coating agent is applied on the A layer (corresponding to 12 layers (A layer) shown in FIG. 1) of the obtained polyester film by a reverse gravure coating method so that the coating amount (after drying) is 0.05 g / m ^2. After coating, heat treatment was performed at 120 ° C. for 30 seconds to obtain a laminated polyester film provided with the B layer.

In addition, the coating agent composition used in order to comprise B layer is as follows.
<< Coating composition >>
Organosiloxane (ethyl silicate 48: Colcoat Co.): 0.9% by weight (based on 100% by weight of solvent)
The mixture was diluted with a mixed solvent of i-propanol / butanol = 6/4 to give 0.9% by weight.

A reverse gravure is applied to the layer B of the obtained laminated polyester film so that the coating amount of the release layer composition-1 comprising the release agent composition shown below is 0.1 g / m ² (after drying). Coating was carried out by a coating method, and a C layer was placed under conditions of a dryer temperature of 120 ° C. and a line speed of 30 m / min to obtain a roll-shaped release polyester film.

In addition, the mold release agent composition used in order to comprise C layer is as follows.
<Releasing agent composition>
-Release layer composition-1
Curable silicone resin (KS-847H: manufactured by Shin-Etsu Chemical) 20 parts Catalyst (PL-50T: manufactured by Shin-Etsu Chemical) 1.0 part MEK / toluene mixed solvent (mixing ratio is 1: 1)
・ Releasing layer composition-2
Curable silicone resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 17 parts Peeling control agent (KS-3800: manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts Addition type platinum catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.0 part MEK / toluene / N-heptane mixed solvent (mixing ratio is 1: 1: 1)
・ Release layer composition-3

Curable silicone resin (LTC303E: manufactured by Toray Dow Corning) 20 parts Addition type platinum catalyst (SRX212: manufactured by Toray Dow Corning) 1.0 part MEK / toluene / n-heptane mixed solvent (mixing ratio is 1: 1: 1) )
Migrating amount of release agent composition-1: 15% by weight
-Release layer composition-4
Curable silicone resin (X-62-5039: manufactured by Shin-Etsu Chemical Co., Ltd.) 14 parts Peeling control agent (KS-3800: manufactured by Shin-Etsu Chemical Co., Ltd.) 6 parts Cross-linking agent (X-92-185: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.4 Part catalyst (PL-5000: manufactured by Shin-Etsu Chemical Co., Ltd.) 2.0 parts MEK / toluene / n-heptane mixed solvent (mixing ratio is 1: 1: 1)
-Release layer composition-5
Curable silicone resin (X-62-5039: manufactured by Shin-Etsu Chemical Co., Ltd.) 12 parts Peeling control agent (KS-3800: manufactured by Shin-Etsu Chemical Co., Ltd.) 8 parts Cross-linking agent (X-92-185: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.4 Part catalyst (PL-5000: manufactured by Shin-Etsu Chemical Co., Ltd.) 2.0 parts MEK / toluene / n-heptane mixed solvent (mixing ratio is 1: 1: 1)

Examples 2-15:
In Example 1, except that the film forming conditions are changed, the A ′ layer and the B layer coating thickness are changed, and the release layer composition change of the C layer is changed, it is manufactured in the same manner as in Example 1 to obtain a release polyester film. It was. The evaluation results of the produced release polyester film were as shown in Tables 1 and 2.

Comparative Examples 1-7:
In Example 1, except that the film forming conditions are changed, the A ′ layer and the B layer coating thickness are changed, and the release layer composition change of the C layer is changed, it is manufactured in the same manner as in Example 1 to obtain a release polyester film. It was. The evaluation results of the produced release polyester film were as shown in Table 3. Comparative Example 1 is an example in which the B layer is not provided.

  The release polyester film of the present invention is contaminated with an adhesive process. It can prevent contamination of the adhesive, increase the adhesive processing yield, and is excellent in foreign matter inspection, so that it can be suitably used for optical applications with strict quality control.

11 Polyester film 12 Coating layer: A layer 12 ′ Coating layer: A layer 13 Coating layer: B layer 14 Release layer: C layer

Claims (3)

A layer obtained by applying a coating solution containing a quaternary ammonium base-containing polymer, a polyethylene glycol-containing acrylate polymer, and a crosslinking agent is provided on both sides of the polyester film, and on at least one of the layers, at least A release film formed by applying a coating agent containing a kind of organosiloxane compound, having a coating layer with a thickness of 10 to 100 nm, and having a release layer on the coating layer, the release film A release polyester film characterized in that the inclination (orientation angle) of the orientation main axis is 12 degrees or less. The release polyester film according to claim 1, wherein the thickness of the layer opposite to the release layer is 40 to 100 nm. The release polyester film according to claim 1 or 2, wherein the heat shrinkage rate after treatment at 150 ° C for 30 minutes simultaneously satisfies the following formulas (1) to (3).
SMD-STD ≦ 1.5 (1)
SMD ≦ 2.5 (2)
STD ≦ 2.0 (3)
(In the above formula, SMD means the shrinkage rate (%) in the film longitudinal direction, and STD means the shrinkage rate (%) in the film width direction).

Images