JP2016216655A - Laminated polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated polyester film capable of highly suppressing electrification by peeling electrification or friction electrification, having good releasability and being able to be suitably used in applications for various protective films, and for various applications for molding, transcription, printing, or the like.SOLUTION: There is provided a laminated polyester film having a coated layer formed by in-line coating from an aqueous coating liquid containing a polyether group-containing silicone and an antistatic agent on at least one surface of a polyester film.SELECTED DRAWING: None

Description

  The present invention relates to a polyester film suitable as a release film having antistatic properties, and is used, for example, for various protective films, various moldings, transfer, printing, etc. The present invention relates to a laminated polyester film having excellent releasability, which can suppress charging due to frictional charging and suppress the adhesion of surrounding dust and the like.

  Conventionally, polyester films represented by polyethylene terephthalate and polyethylene naphthalate have excellent mechanical properties, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, etc., and cost performance. It is used for various purposes. When the polyester film is used as a release film, the release property of the polyester film itself is insufficient, so that a silicone compound is generally used in order to effectively provide the release performance.

  However, since a general plastic film including a polyester film cannot release static electricity, it is charged by peeling of the film or friction caused by a roll, and there is a problem that surrounding dust adheres to the film. The adhesion of dust or the like causes defects such as foreign matter and scratches, and obstruction of the inspection process. The same applies when the above-mentioned silicone compound is used. Therefore, an antistatic agent is used to impart antistatic performance. For example, it has been proposed to use a silicone compound in combination, but it is necessary to use a specific antistatic agent. It may be difficult to mix with a silicone compound to form a uniform coating film, or the coating appearance may not be good and sufficient performance may not be achieved (Patent Documents 1 and 2).

  Because of the problems as described above, a method in which the antistatic agent and the silicone compound are not mixed has been proposed. For example, there is a method in which an antistatic layer is provided on the back side of the silicone compound layer (Patent Document 3). However, when this method is used, the number of manufacturing steps increases and the charge due to film peeling is on the side of the silicone compound layer to be peeled off, which may be insufficient to ensure more effective antistatic performance. is there. Therefore, a film having antistatic performance on the silicone compound side is required.

JP-A-6-116426 JP 2011-201254 A JP-A-9-277451

  The present invention has been made in view of the above circumstances, and the problem to be solved is used for various protective films, various moldings, transfer, printing, etc. Is to provide an antistatic release polyester film having good release properties.

  As a result of intensive studies in view of the above circumstances, the present inventor has found that the use of a laminated polyester film having a specific configuration can easily solve the above-described problems, and has completed the present invention.

  That is, the gist of the present invention resides in a laminated polyester film characterized by having a coating layer containing a polyether group-containing silicone and an antistatic agent on at least one side of the polyester film.

  According to the laminated polyester film of the present invention, when used for various protective films, various molding, transfer, printing, etc., it is possible to provide a polyester film having excellent releasability and low charge. Yes, its industrial value is high.

  The polyester film serving as the substrate constituting the laminated polyester film in the present invention may have a single layer structure or a multilayer structure, and may have a structure other than two layers or three layers unless the gist of the present invention is exceeded. It may be a multilayer or more layers, and is not particularly limited. It is preferable to have a multi-layer structure of two or more layers and to give each layer a characteristic so as to achieve multiple functions.

  The polyester used in the present invention may be a homopolyester or a copolyester. 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. On the other hand, the dicarboxylic acid component of the copolyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 1 type or 2 types or more are mentioned, As a glycol component, 1 type or 2 types or more, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned.

  From the viewpoint of forming a film that can withstand various processing conditions, it is preferable that the mechanical strength and heat resistance (dimensional stability by heating) are high, and for that purpose, it is preferable that the copolymer polyester component is small. Specifically, the proportion of the monomer forming the copolyester in the polyester film is preferably in the range of 10 mol% or less, more preferably 5 mol% or less, and more preferably produced as a by-product during homopolyester polymerization. It is a grade which contains the diether component of 3 mol% or less which is a grade which will carry out. In view of mechanical strength and heat resistance, a more preferable form of polyester is a polyethylene terephthalate polymerized from terephthalic acid and ethylene glycol, or a film formed from polyethylene naphthalate, among the above compounds. In consideration of ease of handling and handling properties as a surface protective film, a film formed from polyethylene terephthalate is more preferable.

  There is no restriction | limiting in particular as a polymerization catalyst of polyester, A conventionally well-known compound can be used, For example, an antimony compound, a titanium compound, a germanium compound, a manganese compound, an aluminum compound, a magnesium compound, a calcium compound etc. are mentioned. Among these, antimony compounds are preferable because they are inexpensive, and titanium compounds and germanium compounds have high catalytic activity, can be polymerized in a small amount, and the amount of metal remaining in the film is small. Since transparency of this becomes high, it is preferable. Furthermore, since a germanium compound is expensive, it is more preferable to use a titanium compound.

  In the case of polyester using a titanium compound, the titanium element content is preferably 50 ppm or less, more preferably 1 to 20 ppm, and still more preferably 2 to 10 ppm. If the content of the titanium compound is too high, the polyester may be deteriorated in the process of melt-extruding the polyester, resulting in a strong yellowish film. If the content is too low, the polymerization efficiency is poor and the cost is low. In some cases, a film having a sufficient strength or a sufficient strength cannot be obtained.

  Moreover, when using the polyester by a titanium compound, it is preferable to use a phosphorus compound in order to reduce the activity of a titanium compound for the purpose of suppressing deterioration in the step of melt extrusion. As the phosphorus compound, orthophosphoric acid is preferable in view of the productivity and thermal stability of the polyester. The phosphorus element content is preferably in the range of 1 to 300 ppm, more preferably 3 to 200 ppm, and still more preferably 5 to 100 ppm with respect to the amount of polyester to be melt-extruded. If the content of the phosphorus compound is too large, it may cause gelation or foreign matter. If the content is too small, the activity of the titanium compound cannot be lowered sufficiently, and the yellowish It may be a film.

  In the polyester layer of the film of the present invention, particles can be blended for the purpose of imparting slipperiness, preventing scratches in each step, and improving anti-blocking properties. When the particles are blended, the kind of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples thereof include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid. Examples thereof include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. 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. Of these, silica particles and calcium carbonate particles are preferable because they are particularly effective in a small amount.

  The average particle size of the particles is preferably 5 μm or less, more preferably 0.01 to 3 μm. When the average particle diameter exceeds 5 μm, there may be a concern about problems due to dropout of particles or reduction in transparency of the film.

  Further, the particle content in the polyester layer cannot be generally described because it has a balance with the average particle diameter of the particles, but is preferably 5% by weight or less, more preferably in the range of 0.0003 to 3% by weight, Preferably it is 0.0005 to 1 weight% of range. When the particle content exceeds 5% by weight, there may be a concern about problems due to dropout of particles or reduction in transparency of the film.

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.

  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.

  In the polyester film of the present invention, conventionally known ultraviolet absorbers, antioxidants, antistatic agents, thermal stabilizers, lubricants, dyes, pigments, and the like can be added as necessary in addition to the above-described particles. .

  The thickness of the polyester film in the present invention is not particularly limited as long as it can be formed as a film, but is preferably 2 to 350 μm, more preferably 5 to 200 μm, and still more preferably 10 to 75 μm. is there.

  As a film forming method of the film of the present invention, a generally known film forming method can be adopted, and there is no particular limitation. For example, when producing a biaxially stretched polyester film, first, the polyester raw material described above is melt-extruded from a die using an extruder, and the molten sheet is cooled and solidified with a cooling roll to obtain an unstretched sheet. 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 or a liquid application adhesion method is preferably employed. Next, the obtained 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 times, preferably 3.0 to 6 times. Next, the film is stretched in the direction perpendicular to the first-stage stretching direction at usually 70 to 170 ° C. and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing heat treatment at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% can be mentioned. 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, 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 180 to 270 ° C. under tension or 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, formation of the coating layer which comprises the laminated polyester film in this invention is demonstrated. Regarding the coating layer, it may be provided by in-line coating which treats the film surface during the process of forming a polyester film, or offline coating which is applied outside the system on a once produced film may be adopted. More preferably, it is formed by in-line coating.

  In-line coating is a method of coating within the process of manufacturing a polyester film, and specifically, a method of coating at any stage from melt extrusion of a polyester to heat setting after stretching and winding up. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, and a film after heat setting and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of stretching in the transverse direction after coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) is particularly excellent. According to such a method, film formation and coating layer formation can be performed at the same time, so there is an advantage in manufacturing cost. In addition, in order to perform stretching after coating, the thickness of the coating layer can be changed by the stretching ratio. Compared to offline coating, thin film coating can be performed more easily.

  Further, by providing the coating layer on the film before stretching, the coating layer can be stretched together with the base film, whereby the coating layer can be firmly adhered to the base film. Furthermore, in the production of a biaxially stretched polyester film, the film can be restrained in the longitudinal and lateral directions by stretching while gripping the film end with a clip, etc. High temperature can be applied while maintaining the properties.

  Therefore, since the heat treatment performed after coating can be performed at a high temperature that cannot be achieved by other methods, the film forming property of the coating layer can be improved, and the coating layer and the base film can be more firmly adhered to each other. Furthermore, a strong coating layer can be obtained. In addition, because of the high temperature, the coating layer can sufficiently react, and the release performance can be more stable.

  In the present invention, it is an essential requirement to have a coating layer containing a polyether group-containing silicone and an antistatic agent.

  In order to impart both release properties and antistatic properties to the coating film, investigations were made in combination with a release agent and an antistatic agent, and it was found that the stability of the liquid deteriorated. When general silicone is used, there may be a phenomenon that the material is separated. In addition, when an ionic material is used as the antistatic agent, there is a concern that if a polymerization type (particularly addition reaction type) silicone by catalytic reaction is used, sufficient performance cannot be exhibited due to a decrease in reactivity. As a result of various studies by the present inventor, the use of polyether group-containing silicone as a release agent improves the stability of the liquid, improves the compatibility of the materials used, and improves the properties of the final film. I found out.

  The coating layer in the present invention has releasability suitable for, for example, various protective films, various moldings, transfer, printing, etc., and particularly suppresses charging due to peeling charging or frictional charging, It is provided to suppress the adhesion of dust and the like.

  The polyether group-containing silicone used for forming the coating layer is a silicone compound having a polyether group. The polyether group is mainly used for improving the dispersibility of silicone in an aqueous solvent, and may be present in the side chain or terminal of the silicone or in the main chain. From the viewpoint of dispersibility in an aqueous solvent, it is preferably present in the side chain or terminal.

  A conventionally well-known structure can be used for a polyether group. From the viewpoint of the dispersibility of the aqueous solvent, an aliphatic polyether group is preferable to an aromatic polyether group, and an alkyl polyether group is preferable among the aliphatic polyether groups. Further, from the viewpoint of synthesis due to steric hindrance, a linear alkyl polyether group is preferable to a branched alkyl polyether group, and among them, a polyether group composed of linear alkyl having 8 or less carbon atoms is preferable. Further, when the developing solvent is water, a polyethylene glycol group or a polypropylene glycol group is preferable in consideration of dispersibility in water, and a polyethylene glycol group is particularly optimal.

  The number of ether bonds of the polyether group is usually in the range of 1-30, preferably in the range of 2-20, more preferably 3 in terms of improving the dispersibility in an aqueous solvent and the durability of the coating layer. There are 15 ranges. When there are few ether bonds, there exists a tendency for a dispersibility to worsen, and conversely when there are too many, there exists a tendency for durability and mold release performance to worsen.

  When the polyether group has a side chain or a terminal of the silicone, the terminal of the polyether group is not particularly limited, and is a hydroxyl group, an amino group, a thiol group, a hydrocarbon group such as an alkyl group or a phenyl group, a carboxylic acid group, Various functional groups such as a sulfonic acid group, an aldehyde group, and an acetal group can be used. Among these, considering the dispersibility in water and the crosslinkability for improving the strength of the coating layer, a hydroxyl group, an amino group, a carboxylic acid group, and a sulfonic acid group are preferable, and a hydroxyl group is particularly optimal.

  As the silicone, conventionally known silicones can be used, and examples thereof include alkyl silicones such as dimethyl silicone and diethyl silicone, phenyl silicones having a phenyl group, and methylphenyl silicone. A silicone having a functional group other than the above-described polyether group can also be used, for example, a hydroxyl group, an amino group, an epoxy group, a carboxylic acid group, a halogen group such as fluorine, a perfluoroalkyl group, or various alkyl groups. And hydrocarbon groups such as various aromatic groups. As other functional groups, silicones having vinyl groups and hydrogen silicones in which hydrogen atoms are directly bonded to silicon atoms are also common, but if left unreacted in the coating layer, it may cause a change in release performance over time. The silicone of the present invention is preferably not contained.

  The polyether group content of the polyether group-containing silicone is usually in the range of 0.001 to 0.30, preferably 0.01 to 0.20% in terms of molar ratio, where the siloxane bond of the silicone is 1. The range is more preferably 0.03 to 0.15%, and still more preferably 0.05 to 0.12%. By using it within this range, it is possible to maintain water dispersibility, durability of the coating layer and good releasability.

  The molecular weight of the polyether group-containing silicone is preferably not so large in consideration of dispersibility in an aqueous solvent, and is preferably in consideration of the durability and release performance of the coating layer. It is required to balance these characteristics, and the number average molecular weight is preferably in the range of 1000 to 100,000, more preferably in the range of 3000 to 30000, and still more preferably in the range of 5000 to 10,000.

  Further, considering the time-dependent change and release performance of the coating layer and the contamination of various processes, it is preferable that the silicone low molecular component (number average molecular weight is 500 or less) is as small as possible. The total ratio is preferably 15% by weight or less, more preferably 10% by weight or less, and further preferably 5% by weight or less.

  Since polyether group-containing silicone is difficult to apply alone, it is preferable to use it dispersed in water. Various conventionally known dispersants can be used for dispersion, and examples thereof include anionic dispersants, nonionic dispersants, cationic dispersants, and amphoteric dispersants. Among these, when considering the dispersibility of the polyether group-containing silicone and the compatibility with a polymer other than the polyether group-containing silicone that can be used for forming the coating layer, an anionic dispersant and a nonionic dispersant are preferable. . Moreover, it is also possible to use a fluorine compound for these dispersing agents.

  Anionic dispersants include sodium dodecylbenzenesulfonate, sodium alkylsulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate, polyoxyalkylene alkenyl. Sulfonates such as ether ammonium sulfate, sulfate esters, carboxylates such as sodium laurate and potassium oleate, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates Examples thereof include phosphates such as salts. Among these, a sulfonate system is preferable from the viewpoint of good dispersibility.

  Nonionic dispersants include, for example, ether type compounds in which alkylene oxides such as ethylene oxide and propylene oxide are added to compounds having hydroxyl groups such as higher alcohols and alkylphenols, and polyhydric alcohols such as glycerin and saccharides and ester bonds. Examples include an ester type, an ester / ether type in which an alkylene oxide is added to a fatty acid or a polyhydric alcohol fatty acid ester, and an amide type in which a hydrophobic group and a hydrophilic group are connected via an amide bond. Among these, an ether type is preferable in consideration of solubility in water and stability, and a type to which ethylene oxide is added is more preferable in consideration of handleability.

  Although it depends on the molecular weight and structure of the polyether group-containing silicone to be used and depends on the type of the dispersant to be used, it cannot be said unconditionally. As a weight ratio, it is preferably 0.01 to 0.5, more preferably 0.05 to 0.4, and still more preferably 0.1 to 0.3.

  The antistatic agent used for forming the coating layer is not particularly limited, and a conventionally known antistatic agent can be used. However, since the heat resistance and heat and humidity resistance are good, the polymer type The antistatic agent is preferably used. Examples of the polymer type antistatic agent include a compound having an ammonium group, a conductive polymer, a polyether compound, a compound having a sulfonic acid group, and a betaine compound.

  The compound having an ammonium group is a compound having an ammonium group in the molecule, and examples thereof include aliphatic amines, alicyclic amines, and ammonium compounds of aromatic amines. The compound having an ammonium group is preferably a compound having a polymer type ammonium group, and the ammonium group has a structure incorporated in the main chain or side chain of the polymer, not as a counter ion. It is preferable. For example, a polymer obtained by polymerizing a monomer containing an addition polymerizable ammonium group or a precursor of an ammonium group such as an amine is used as a polymer compound having an ammonium group, which is preferably used. As the polymer, a monomer containing an addition polymerizable ammonium group or a precursor of an ammonium group such as an amine may be polymerized alone, or it may be a copolymer of a monomer containing these and another monomer. May be.

  Among the compounds having an ammonium group, a compound having a pyrrolidinium ring is preferred from the viewpoint of excellent antistatic properties and heat stability.

The two substituents bonded to the nitrogen atom of the compound having a pyrrolidinium ring are each independently an alkyl group, a phenyl group, and the like. Even if these alkyl groups and phenyl groups are substituted with the groups shown below, Good. Substitutable groups are, for example, hydroxyl group, amide group, ester group, alkoxy group, phenoxy group, naphthoxy group, thioalkoxy, thiophenoxy group, cycloalkyl group, trialkylammonium alkyl group, cyano group, and halogen. Moreover, the two substituents bonded to the nitrogen atom may be chemically bonded. For example, — (CH ₂ ) _m — (m = 2 to 5), —CH (CH ₃ ) CH (CH ₃ ) —, —CH═CH—CH═CH—, —CH═CH—CH═N—, —CH═CH—N═C—, —CH ₂ OCH ₂ —, — (CH ₂ ) ₂ O (CH ₂ ) ₂ — and the like.

  In the present invention, the polymer having a pyrrolidinium ring is obtained by cyclopolymerizing a diallylamine derivative using a radical polymerization catalyst. The polymerization is carried out by using a polymerization initiator such as hydrogen peroxide, benzoyl peroxide, tertiary butyl peroxide in a polar solvent such as water or methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane, acetonitrile as a solvent. Although it can implement by a method, it is not limited to these. In the present invention, a compound having a diallylamine derivative and a polymerizable carbon-carbon unsaturated bond may be used as a copolymerization component.

  In addition, as the compound having an ammonium group, a compound having a structure represented by the following formula (1) is preferable in that it is excellent in antistatic properties and wet heat stability. A single polymer or copolymer, or a plurality of other components may be copolymerized.

For example, in the above formula, the substituent R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, a hydrocarbon group such as a phenyl group, R ² is —O—, —NH— or —S—, and R ³ is R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group, or an alkylene group having 1 to 20 carbon atoms or another structure that can form the structure of Formula 1. Or a hydrocarbon group provided with a functional group such as a hydroxyalkyl group, and X ⁻ represents various counter ions.

Among the above, in view of excellent antistatic properties and wet heat resistance, in particular, in the formula (1), the substituent R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ³ is preferably an alkyl group having 1 to 6 carbon atoms, and R ⁴ , R ⁵ and R ⁶ are preferably each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably , R ⁴ , R ⁵ , or R ⁶ is a hydrogen atom, and the other substituent is an alkyl group having 1 to 4 carbon atoms.

  Examples of the anion serving as the counter ion (counter ion) of the ammonium group of the compound having an ammonium group described above include ions such as halogen ions, sulfonates, phosphates, nitrates, alkylsulfonates, and carboxylates.

Moreover, the number average molecular weight of the compound which has an ammonium group is 1000-500000, Preferably it is 2000-350,000, More preferably, it is 5000-200000. When the molecular weight is less than 1000, the strength of the coating film may be weakened or the heat stability may be poor.
On the other hand, when the molecular weight exceeds 500,000, the viscosity of the coating solution increases, and the handleability and applicability may deteriorate.

  Examples of the conductive polymer include polythiophene-based, polyaniline-based, polypyrrole-based, and polyacetylene-based polymers. Among them, for example, polythiophene-based polymers using poly (3,4-ethylenedioxythiophene) in combination with polystyrene sulfonic acid. Are preferably used. The conductive polymer is preferable to the other antistatic agents described above in that the resistance value is low. However, on the other hand, it is necessary to devise measures such as reducing the amount used in applications where coloring and cost are a concern. In addition, compatibility with the materials used may not be good, and depending on the combination of materials in the coating layer, the coating appearance and haze may increase, so depending on the application used is necessary.

  Examples of polyether compounds include polyethylene oxide, polyether ester amide, acrylic resins having polyethylene glycol in the side chain, and the like. The compatibility with the polyether group-containing silicone is good, but the antistatic property may be inferior.

  The compound having a sulfonic acid group is a compound containing a sulfonic acid or a sulfonate in the molecule. For example, a compound having a large amount of sulfonic acid or a sulfonate such as polystyrene sulfonic acid is preferably used. It is done.

  In order to improve the strength, mold release performance and antistatic performance of the coating layer, it is preferable to use a crosslinking agent for forming the coating layer. A conventionally well-known material can be used with a crosslinking agent, For example, a melamine compound, an oxazoline compound, an epoxy compound, an isocyanate type compound, a silane coupling compound, a carbodiimide type compound, a hydrazide compound, an aziridine compound etc. are mentioned. From the viewpoint of the strength of the coating layer and the stable release performance, melamine compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, silane coupling compounds, carbodiimide compounds are preferred, melamine compounds, oxazoline compounds, epoxy compounds, isocyanates. Of these compounds, silane coupling compounds are more preferred, and melamine compounds are particularly preferred. These cross-linking agents may be used alone or in combination of two or more.

  The melamine compound is a compound having a melamine skeleton in the compound. For example, an alkylolized melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and these Mixtures can be used. As alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, as a melamine compound, either a monomer or a multimer more than a dimer may be sufficient, or a mixture thereof may be used. In view of reactivity with various compounds, it is preferable that the melamine compound contains a hydroxyl group. Further, a product obtained by co-condensing urea or the like with a part of melamine can be used, and a catalyst can be used to increase the reactivity of the melamine compound.

  The oxazoline compound is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable, and can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. The other monomer is not limited as long as it is a monomer copolymerizable with an addition polymerizable oxazoline group-containing monomer. For example, alkyl (meth) acrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, (meth) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; (meth) acrylamide, N-alkyl ( (Meth) acrylamide, N, N-dialkyl (meth) acrylamide, As the alkyl group, unsaturated amides such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group and cyclohexyl group); vinyl acetate Vinyl esters such as vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride And α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like, and one or more of these monomers can be used.

  The content of the oxazoline group contained in the oxazoline compound is usually 0.5 to 10 mmol / g, preferably 1 to 9 mmol / g, more preferably 3 to 8 mmol / g, and further preferably 4 to 6 mmol in terms of the amount of the oxazoline group. / G. Use within the above range is preferable because the release performance is improved.

  The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A and the like hydroxyl groups and amino groups, There are polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Examples of the polyglycidyl ether and diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , Polypropylene glycol diglycidyl ether, poly Examples of tetramethylene glycol diglycidyl ether and monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds such as N, N, N ′, N′-tetraglycidyl-m-xylyl. Examples include range amine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  The isocyanate compound is a compound having an isocyanate derivative structure typified by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate, and aromatic rings such as α, α, α ′, α′-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), isopropylidene dicyclohexyl diisocyanate Ne Alicyclic isocyanates such as bets are exemplified. Further, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimide modified products of these isocyanates are also included. These may be used alone or in combination. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

  When used in the state of blocked isocyanate, the blocking agent includes, for example, bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcohols such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. Compounds, active methylene compounds such as methyl isobutanoyl acetate, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, mercaptan compounds such as butyl mercaptan, dodecyl mercaptan, ε-caprolactam, δ-valerolactam, etc. Lactam compounds, amine compounds such as diphenylaniline, aniline, ethyleneimine, acetanilide, acid amide compounds of acetic acid amide, Examples include oxime compounds such as maldehyde, acetoald oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more. Among these, an active methylene compound is preferable from the viewpoint of particularly good release performance.

  In addition, the isocyanate compound in the present invention may be used alone, or may be used as a mixture or bond with various polymers. In the sense of improving the dispersibility and crosslinkability of the isocyanate compound, it is also preferable to use a mixture or a bond with a polyester resin or a urethane resin.

The silane coupling compound is a compound having a structure represented by the general _{X n -Si (OR) 4-} n (n = 1~3), and affinity organic material in one molecule Alternatively, it is a silane compound having a site X having a reactive functional group and a functional group OR having affinity or reactivity with an inorganic material. Examples of the functional group in the site X having a functional group include an epoxy group, a (meth) acryloxy group, an amino group, a vinyl group, a mercapto group, a styryl group, a sulfide group, an isocyanate group, and the like. May be directly bonded or may be bonded via a hydrocarbon group such as an alkylene group such as methylene, ethylene or propylene. Examples of the functional group OR include alkoxy groups such as methoxy, ethoxy, and isopropoxy, and acetoxy groups, but are not particularly limited thereto.

  Among these, considering the crosslinkability with various organic materials, the functional group in the site X having a functional group is preferably an epoxy group, a (meth) acryloxy group, an amino group, a vinyl group, a mercapto group, particularly a polyester resin. An epoxy group and a (meth) acryloxy group are preferred because the mold release performance is improved in a system used in combination with a polymer such as.

  A carbodiimide-based compound is a compound having a carbodiimide structure, and is used to improve adhesion with various surface functional layers that can be formed on a coating layer and to improve the heat and humidity resistance of the coating layer. is there. The carbodiimide compound is a compound having one or more carbodiimide or carbodiimide derivative structures in the molecule, but a polycarbodiimide compound having two or more in the molecule is more preferable for better adhesion and the like.

  The carbodiimide compound can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and any of aromatic and aliphatic compounds can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexa Examples include methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

  Furthermore, in order not to lose the effect of the present invention, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound, adding a surfactant, polyalkylene oxide, quaternary ammonium salt of dialkylamino alcohol, You may add and use hydrophilic monomers, such as a hydroxyalkyl sulfonate.

  The content of the carbodiimide group contained in the carbodiimide-based compound is a carbodiimide equivalent (weight of the carbodiimide compound to give 1 mol of carbodiimide group [g]) and is usually 100 to 1000, preferably 250 to 800, more preferably 300. It is -700, More preferably, it is the range of 350-650. Use within the above range is preferable because the release performance is improved.

  These cross-linking agents are used in a design that improves the performance of the coating layer by reacting in the drying process or film forming process. It can be inferred that unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof exist in the finished coating layer.

  In forming the coating layer, it is possible to use a polymer other than polyether group-containing silicone and antistatic agent from the viewpoints of appearance of coating layer, stabilization of mold release performance, adhesion to polyester film of substrate, etc. It is.

  A conventionally well-known polymer can be used as a polymer. Specific examples of the polymer include polyester resin, acrylic resin, urethane resin, polyvinyl (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.), polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches and the like. . Among these, polyester resin, acrylic resin, urethane resin, and polyvinyl alcohol are preferably used in combination from the viewpoint of improving the coating appearance, stabilizing the release performance, and adhesion to the polyester film of the base material. Resins, acrylic resins and urethane resins are preferred. In view of the fact that the substrate is a polyester film, a resin having a polyester skeleton is more preferable from the viewpoint of adhesion to the polyester film of the substrate.

  The polyester resin includes, for example, those composed of the following polyvalent carboxylic acid and polyvalent hydroxy compound as main constituent components. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6 -Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutar Acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt and ester-forming derivatives thereof can be used. As the polyvalent hydroxy compound, ethylene Recall, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol , Neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol Polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate, and the like can be used. One or more compounds may be appropriately selected from these compounds, and a polyester resin may be synthesized by a conventional polycondensation reaction.

  The acrylic resin is a polymer composed of a polymerizable monomer including acrylic and methacrylic monomers. These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion (sometimes a mixture of polymers) is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included. Moreover, in order to improve adhesiveness more, it is also possible to contain a hydroxyl group and an amino group.

  The polymerizable monomer is not particularly limited, but particularly representative compounds include, for example, various carboxyl groups such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Monomers, and salts thereof; such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate Various hydroxyl group-containing monomers; various (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate; (Meth) acrylamide, Various nitrogen-containing compounds such as acetone acrylamide, N-methylol acrylamide or (meth) acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene, and various vinyls such as vinyl propionate Esters; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, etc .; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and biridene chloride Various conjugated dienes such as butadiene.

  The urethane resin is a polymer compound having a urethane bond in the molecule, and is usually produced by a reaction between a polyol and an isocyanate. Examples of the polyol include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination.

  Polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides. Product and polyhydric alcohol (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol 2-methyl-2-propyl-1 3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexane Diol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyl dialkanolamine, lactone diol, etc.) and those having derivative units of lactone compounds such as polycaprolactone.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Examples of the polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane. Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane and the like can be mentioned. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of the polycarbonate-based polyols obtained from these reactions include poly (1,6-hexylene) carbonate, poly (3- And methyl-1,5-pentylene) carbonate.

  Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and the like.

  Considering the appearance of coating and stabilization of the release performance, among the above polyols, polyester polyols and polycarbonate polyols are more preferably used, and polyester polyols are particularly preferable.

  Examples of the polyisocyanate compound used for obtaining the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate, α, α, α ′, α ′. -Aliphatic diisocyanates having aromatic rings such as tetramethylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl Methanzi Cyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination.

  A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with an isocyanate group. Alternatively, a chain extender having two amino groups can be mainly used.

  Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, and esters such as neopentyl glycol hydroxypivalate. And glycols such as glycols. Examples of the chain extender having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, and diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3- Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- Aliphatic diamines such as decane diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isoprobilitincyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1 , 3-Bisaminomethylcyclohexa And alicyclic diamines such as

  The urethane resin in the present invention may use a solvent as a medium, but preferably uses water as a medium. In order to disperse or dissolve the urethane resin in water, there are a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, and a water-soluble type. In particular, the self-emulsification type in which an ionic group is introduced into the structure of the urethane resin to form an ionomer is preferable because of excellent storage stability of the liquid and water resistance and transparency of the resulting coating layer.

Examples of the ionic group to be introduced include various groups such as a carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid, quaternary ammonium salt, and the like, and a carboxyl group is preferable. As a method for introducing a carboxyl group into a urethane resin, various methods can be taken in each stage of the polymerization reaction. For example, there are a method of using a carboxyl group-containing resin as a copolymer component during prepolymer synthesis, and a method of using a component having a carboxyl group as one component such as polyol, polyisocyanate, and chain extender. In particular, a method in which a desired amount of carboxyl groups is introduced using a carboxyl group-containing diol depending on the amount of this component charged is preferred.
For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid and the like are copolymerized with a diol used for polymerization of a urethane resin. Can do. The carboxyl group is preferably in the form of a salt neutralized with ammonia, amine, alkali metal, inorganic alkali or the like. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a urethane resin, the carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a crosslinking reaction point by another crosslinking agent. Thereby, it is possible to further improve the durability, solvent resistance, water resistance, blocking resistance, and the like of the obtained coating layer, as well as excellent stability in a liquid state before coating.

  Polyvinyl alcohol has a polyvinyl alcohol site, and conventionally known polyvinyl alcohol can be used, including modified compounds partially acetalized or butyralized with respect to polyvinyl alcohol. The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably 300 to 40,000. When the degree of polymerization is less than 100, the water resistance of the coating layer may decrease. Further, the saponification degree of polyvinyl alcohol is not particularly limited, but it is preferably a saponified polyvinyl acetate having a range of 70 mol% or more, more preferably 80 to 99 mol%, and still more preferably 86 to 97 mol%.

  Also, in order to improve the appearance and reduce the surface resistance, for example, a polyalkylene oxide, glycerin, polyglycerin, glycerin or an alkylene oxide adduct to polyglycerin may be used in combination with a polyol compound or a polyether compound. This is one of the preferred forms.

  Preferred as the polyalkylene oxide or derivative thereof is a compound having an ethylene oxide or propylene oxide structure. If the alkyl group in the alkylene oxide structure is too long, the hydrophobicity becomes strong, the uniform dispersibility in the coating solution tends to deteriorate, and the antistatic property tends to deteriorate. Particularly preferred is polyethylene oxide. Moreover, the thing of 200-2000 is more preferable in a weight average molecular weight.

  Polyglycerol is a compound in which two or more glycerols are polymerized, and the degree of polymerization is preferably in the range of 2-20. When glycerin is used, transparency may be slightly inferior.

  Further, the alkylene oxide adduct to glycerin or polyglycerin has a structure in which alkylene oxide or a derivative thereof is added to the hydroxyl group of glycerin or polyglycerin.

  Here, the structure of the alkylene oxide added or its derivative may differ for every hydroxyl group of a glycerol or polyglycerol structure. Moreover, it is sufficient that it is added to at least one hydroxyl group in the molecule, and alkylene oxide or a derivative thereof need not be added to all hydroxyl groups.

  Moreover, what is preferable as an alkylene oxide or its derivative added to glycerol or polyglycerol is a compound which has ethylene oxide or a propylene oxide structure. If the alkyl chain in the alkylene oxide structure becomes too long, the hydrophobicity becomes strong, the uniform dispersibility in the coating solution tends to deteriorate, and the antistatic property and transparency tend to deteriorate. Particularly preferred is ethylene oxide. The number of additions is preferably in the range of 250 to 2000 in terms of the number average molecular weight as the final compound, and more preferably in the range of 300 to 1000.

  In forming the coating layer, particles may be used in combination for blocking and improving slipperiness. However, from the viewpoint of transparency and stabilization of the release performance, it is preferable not to use much.

  Furthermore, as long as it does not impair the gist of the present invention, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an ultraviolet absorber, an antioxidant, a foaming agent, It is also possible to use dyes, pigments and the like in combination.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the ratio of the polyether group-containing silicone is usually 3 to 99% by weight, preferably 8 to 85% by weight, more preferably 12 to 70% by weight, Preferably it is the range of 16-50 weight%. When it is out of the above range, the other performance may be deteriorated due to the release performance and the small amount of other components.

  As a ratio in the coating layer which the laminated polyester film in the present invention constitutes, the ratio of the antistatic agent is usually 1 to 97% by weight. When a material other than the conductive polymer is used as the antistatic agent, it is preferably in the range of 10 to 85% by weight, more preferably 20 to 75% by weight, and further preferably 25 to 55% by weight. When a conductive polymer is used as the antistatic agent, it is preferably in the range of 1 to 85% by weight, more preferably 3 to 60% by weight, and still more preferably 6 to 40% by weight. When it is out of the above range, the other performance may be deteriorated due to the antistatic performance and the lack of other components.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the ratio of the crosslinking agent is preferably 5 to 80% by weight, more preferably 10 to 65% by weight, and further preferably 25 to 55% by weight. is there. By using it within the above range, it is easy to increase the strength of the coating film and to ensure release performance.

  The analysis of the components in the coating layer can be performed, for example, by analysis of TOF-SIMS, ESCA, fluorescent X-ray, IR, or the like.

  Regarding the formation of the coating layer, in order to enable environmental considerations and in-line coating, a coating solution prepared by adjusting the above-mentioned series of compounds in an aqueous system and having a solid content concentration of about 0.1 to 80% by weight on the polyester film is used. It is preferable to produce a laminated polyester film in the manner of applying to the substrate. An aqueous system is an aqueous solution or a dispersion, and as a solvent component in the coating solution, 50% by weight or more is water, preferably 70% by weight or more, more preferably 85% by weight or more, and still more preferably. 95% by weight or more is water. In particular, since the polyether group-containing silicone has a hydrophilic group, it is more compatible with water than other mold release agents such as silicone compounds, so that it is easy to use in an aqueous system and is a preferred form. However, a small amount of an organic solvent may be contained in the coating solution for the purpose of improving dispersibility in water, improving the film forming property, and the like. Moreover, only one type of organic solvent may be used, and two or more types may be used as appropriate.

  Regarding the laminated polyester film in the present invention, the thickness of the coating layer provided on the polyester film is preferably 0.001 to 1 μm, more preferably 0.01 to 0.5 μm, still more preferably 0.02 to 0.3 μm. Especially preferably, it is the range of 0.04-0.2 micrometer. When the film thickness exceeds 1 μm, the appearance and transparency may be deteriorated, and when the film thickness is less than 0.005 μm, sufficient releasability and antistatic properties may not be obtained.

  Examples of the method for forming the coating layer of the present invention include gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze coating, and impregnation. Conventionally known coating methods such as coat, kiss coat, spray coat, calendar coat, and extrusion coat can be used.

  In the present invention, the drying and curing conditions for forming the coating layer on the polyester film are not particularly limited, but for the drying of water used in the coating solution, preferably 70 to 150 ° C, More preferably, it is 80-130 degreeC, More preferably, it is the range of 90-120 degreeC. The drying time is generally 3 to 200 seconds, preferably 5 to 120 seconds. Moreover, in order to improve the mold release performance and intensity | strength of an application layer, In a film manufacturing process, Preferably it is 180-270 degreeC, More preferably, it is 200-250 degreeC, More preferably, it passes through the heat treatment process of the range of 210-240 degreeC. It is. The time for the heat treatment step is generally 3 to 200 seconds, preferably 5 to 120 seconds.

  Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed. 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.

  The haze of the polyester film of the present invention is not particularly limited. For example, when used for a strict inspection such as a polarizing plate for the purpose of a protective film, the inspection light is used for a more accurate inspection. Therefore, it is preferable that the haze is low. When used in such applications, the preferred haze is 4.0% or less, more preferably 3.0% or less, still more preferably 2.0% or less, and particularly preferably 0.2 to 1. The range is 5%.

  As the mold release performance of the coated layer of the laminated polyester film of the present invention, as an untreated coated layer, the peel force (normal peel force) for an acrylic adhesive tape is preferably 1000 mN / cm or less, more preferably The range is 500 mN / cm or less, more preferably 200 mN / cm or less, and particularly preferably 100 mN / cm or less. By setting the amount within the above range, the peeling operation becomes easy.

The surface resistance value of the polyester film (coating layer surface) of the present invention is preferably 5 × 10 ¹² Ω or less, more preferably 5 × 10 ¹¹ Ω or less, further preferably 1 × 10 ¹¹ Ω or less, and particularly preferably 5 ×. The range is 10 ¹⁰ Ω or less. By setting it as the above range, it is possible to prevent the surrounding dust from being attached.

  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) Method for measuring the 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. And dissolved at 30 ° C.

(2) Method for measuring film thickness of coating layer The surface of the coating layer was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, a coating layer cross-section was measured by using a TEM (Hitachi High Technologies Corporation H-7650, accelerating voltage 100 V). The film thickness was measured at a location not including the particle portion.

(3) Method for measuring number average molecular weight of polyether group-containing silicone Polyether group-containing silicone was adjusted to a toluene solution, and measurement was performed using GPC (HLC-8120GPC manufactured by Tosoh Corporation) with toluene as an eluent. The number average molecular weight was calculated in terms of polystyrene.

(4) Functional group confirmation of polyether group-containing silicone Using polyether (AVANCE III600 manufactured by Bruker Biospin), the polyether group-containing silicone is assigned each peak of ¹ H-NMR, and the amount of dimethylsiloxane and polyether group The presence or absence of vinyl silane or hydrogen silane was confirmed.

(5) Measuring method of haze It measured by JISK7136 using the haze meter HM-150 by Murakami Color Research Laboratory.

(6) Measuring method of peeling force (normal peeling force) of coating layer An acrylic adhesive tape (Nitto Denko Co., Ltd. No. 502, substrate thickness 25 μm) is applied to the surface of the coating layer with a width of 5 cm and a 2 kg rubber with a width of 5 cm. One reciprocal pressing was performed with a roller, and the peeling force after being left at room temperature for 1 hour was measured. The peeling force used was “Ezgraph” manufactured by Shimadzu Corporation, and was peeled 180 ° under conditions of a tensile speed of 300 mm / min, and the peeling force was measured.

(7) Measuring method of surface resistance of coating layer side Based on the method of the following (7-1), the surface resistance of the coating layer was measured. In the method (7-1), since the surface resistivity lower than 1 × 10 ⁸ Ω cannot be measured sufficiently, the method (7-2) was used for the sample that could not be measured in (7-1).

(7-1) Using a high resistance measuring instrument manufactured by Nippon Hewlett-Packard Co., Ltd .: HP4339B and measuring electrode: HP16008B, adjusting the polyester film sufficiently in a measurement atmosphere of 23 ° C. and 50% RH, and applying voltage of 100V The surface resistance of the coating layer after 1 minute was measured.
(7-2) Low resistance meter manufactured by Mitsubishi Chemical Co., Ltd .: Loresta GP MCP-T600 was used, the sample was conditioned for 30 minutes in a measurement atmosphere of 23 ° C. and 50% RH, and then the surface resistance of the coating layer was measured.

(8) Dust adhesion evaluation method on the coating layer side After sufficiently adjusting the humidity of the polyester film in a measurement atmosphere of 23 ° C. and 50% RH, the coating layer is rubbed 10 times with a cotton cloth. This was brought close to the finely crushed cigarette ash and the ash adhesion was evaluated according to the following criteria.
○: Even if the film is brought into contact with ash, it does not adhere. Δ: When the film is brought into contact with ash, it adheres a little.

(9) Method for evaluating strength of coating layer The surface of the coating layer of the laminated polyester film is rubbed three times with the belly of the finger, and when the peeling of the coating layer is not observed, the peeling of the coating layer is slightly seen and slightly whitish The case was marked with Δ, and the case where peeling of the coating layer was observed was marked with ×.

The polyester used in the examples and comparative examples was prepared as follows.
<Method for producing polyester (A)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 30 ppm of ethyl acid phosphate with respect to the resulting polyester, and 100 ppm of magnesium acetate tetrahydrate with respect to the resulting polyester as the catalyst at 260 ° C. in a nitrogen atmosphere at 260 ° C. The reaction was allowed to proceed. Subsequently, 50 ppm of tetrabutyl titanate was added to the resulting polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, the pressure was reduced to 0.3 kPa in absolute pressure, and melt polycondensation was further carried out for 80 minutes. A polyester (A) having 0.63 and an amount of diethylene glycol of 2 mol% was obtained.

<Method for producing polyester (B)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and magnesium acetate tetrahydrate as a catalyst were subjected to an esterification reaction at 225 ° C. in a nitrogen atmosphere at 900 ppm with respect to the produced polyester. Subsequently, 3500 ppm of orthophosphoric acid was added to the produced polyester, and 70 ppm of germanium dioxide was added to the produced polyester. The temperature was raised to 280 ° C. over 2 hours and 30 minutes, and the pressure was reduced to an absolute pressure of 0.4 kPa. After 85 minutes of melt polycondensation, polyester (B) having an intrinsic viscosity of 0.64 and a diethylene glycol amount of 2 mol% was obtained.

<Method for producing polyester (C)>
In the production method of polyester (A), polyester (C) is obtained using the same method as the production method of polyester (A) except that 0.3 part by weight of silica particles having an average particle diameter of 2 μm is added before melt polymerization. It was.

Examples of compounds constituting the coating layer are as follows.
(Example compounds)
・ Polyether group-containing silicone: (IA)
Polyether group-containing silicone having a number average molecular weight of 7000 (silicone siloxane) containing 1 polyethylene glycol (terminated with a hydroxyl group) having an ethylene glycol chain of 8 with respect to dimethylsiloxane 100 in the dimethyl silicone side chain in a molar ratio. When the bond is 1, the ether bond of the polyether group is 0.07 at a molar ratio). 3% of low molecular components having a number average molecular weight of 500 or less, no vinyl group (vinyl silane) and hydrogen group (hydrogen silane) bonded to silicon exist. In addition, this compound used the polyether group containing silicone as 1 by weight ratio, mix | blended sodium dodecylbenzenesulfonate in the ratio of 0.25, and used it for the water-dispersed layer formation.

・ Polyether group-containing silicone: (IB)
Polyether group-containing silicone having a number average molecular weight of 7200 (silicone) containing 1.5 polyethylene glycol (terminated with a hydroxyl group) having an ethylene glycol chain of 8 with respect to dimethylsiloxane 100 in the side chain of dimethyl silicone. When the siloxane bond of 1 is 1, the ether bond of the polyether group is 0.11. 3% of low molecular components having a number average molecular weight of 500 or less, no vinyl group (vinyl silane) and hydrogen group (hydrogen silane) bonded to silicon exist. In addition, this compound used the polyether group containing silicone as 1 by weight ratio, mix | blended sodium dodecylbenzenesulfonate in the ratio of 0.25, and used it for the water-dispersed layer formation.

・ Antistatic agent (compound having ammonium group): (IIA)
Polymer polymerized with the following composition having a pyrrolidinium ring in the main chain: Diallyldimethylammonium chloride / dimethylacrylamide / N-methylolacrylamide = 90/5/5 (mol%). Number average molecular weight 30000.

・ Antistatic agent (conductive polymer): (IIB) Poly (3,4-ethylenedioxythiophene) combined with polystyrene sulfonic acid

Melamine cross-linking agent: (III) hexamethoxymethylol melamine

・ Polyether compounds: (IV)
Polyethylene oxide adduct to diglycerin structure, number average molecular weight 350.

・ Polyester resin: (V)
Water dispersion of polyester resin having the following composition: Monomer composition: (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4-butanediol / diethylene glycol = 56 / 40/4 // 70/20/10 (mol%)

・ Addition reaction type silicone: (VI)
Addition-type silicone aqueous dispersion mixed with a compound of the following composition: methyl hydrogen polysiloxane containing 80% by weight of methyl vinyl polysiloxane containing 0.6 mol% of vinyl groups and 30 mol% of hydrogen silane groups (hydrogen groups) 5% by weight, 5% by weight of 3-glycidoxypropyltrimethoxysilane, 10% by weight of polyethylene glycol butyl ether, and an aqueous dispersion containing a platinum catalyst.

Example 1:
A mixed raw material in which polyesters (A), (B), and (C) were mixed in proportions of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) were each 97 %, 3% of the mixed raw material is used as an intermediate layer raw material, each is supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. Coextruded and cooled and solidified in a layer configuration of layers (surface layer / intermediate layer / surface layer = 2: 21: 2 discharge amount) to obtain an unstretched sheet.
Next, the film was stretched 3.3 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating solution 1 shown in Table 1 below was applied to the film thickness of the coating layer (dried) on one side of the machined film. After coating to 0.03 μm, guided to a tenter, dried at 95 ° C. for 10 seconds, stretched 4.3 times at 120 ° C. in the transverse direction, and heat-treated at 230 ° C. for 10 seconds The polyester film was relaxed by 2% in the transverse direction to obtain a polyester film having a thickness of 25 μm.

  When the obtained polyester film was evaluated, the releasability and antistatic property were good. The properties of this film are shown in Table 2 below.

Examples 2-13:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. The finished polyester film was as shown in Table 2 and had good release properties and antistatic properties.

Comparative Example 1:
In Example 1, it manufactured like Example 1 except not providing an application layer, and obtained the polyester film. When the completed laminated polyester film was evaluated, it was as shown in Table 2 and was inferior in releasability and antistatic properties.

Comparative Examples 2 and 3:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. When the completed laminated polyester film was evaluated, it was as shown in Table 2. In some cases, the release property and antistatic property were inferior.

Comparative Example 4:
When an attempt was made to adjust the coating solution 13 shown in Table 1 for the coating agent composition, a precipitate was generated and the solution was not suitable for coating.

  The release film of the present invention can be suitably used, for example, for various protective films, for various moldings, for transfer, for printing, etc., particularly in applications requiring release properties and antistatic properties. it can.

Claims (3)

A laminated polyester film comprising a coating layer containing a polyether group-containing silicone and an antistatic agent on at least one side of the polyester film. The laminated polyester film according to claim 1, wherein the coating layer is a coating layer formed from an aqueous coating solution containing a polyether group-containing silicone and an antistatic agent. The laminated polyester film according to claim 1 or 2, wherein the coating layer is formed by in-line coating.