JP5985563B2 - Laminated polyester film - Google Patents

Description

  The present invention relates to a laminated polyester film, and has good release performance in applications such as adhesive separators used for various tapes, ceramic production, various surface protection films, polarizing plate production, and the like. The present invention relates to a laminated polyester film.

  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 a polyester film is used as a release film, it has a drawback of poor practicality because of its insufficient release properties for various resins and adhesives. For this reason, conventionally, a method of laminating a release coating film on the surface of a polyester film has been studied.

  However, generally used releasable coating films often use organic solvent-based silicone compounds, and it is difficult to say that they are excellent in consideration of the environment in recent years. In addition, in a releasable coating film by an addition reaction using a metal catalyst, it may be difficult to adjust the reaction, and there is a problem that the releasability is not stabilized due to remaining functional groups.

JP 2004-142179 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is in various applications such as adhesive separators used for various tapes, ceramic production, various surface protection films, polarizing plate production, etc. An object of the present invention is to provide a laminated polyester film that is considered and has excellent release performance.

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

That is, the gist of the present invention is formed from an aqueous coating solution containing at least one crosslinking agent selected from polyether group-containing silicone and melamine compounds, oxazoline compounds, epoxy compounds, and isocyanate compounds on at least one surface of a polyester film. The present invention resides in a laminated polyester film having a coated layer.

  According to the laminated polyester film of the present invention, a base film having good release performance is used for various tapes, ceramics, various surface protective films, adhesive separators used at the time of polarizing plate production, etc. The industrial value is high.

  The polyester film constituting the laminated polyester film in the present invention may have a single layer structure or a multilayer structure, and may have four or more layers as long as it does not exceed the gist of the present invention other than a two-layer or three-layer structure. It may be a multilayer, and is not particularly limited.

  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.

  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 mainly for the purpose of imparting slipperiness and preventing scratches in each step. 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.

  Moreover, the average particle diameter of the particles is preferably 5.0 μm or less, and more preferably in the range of 0.01 to 3.0 μm. When the average particle diameter exceeds 5.0 μm, the surface roughness of the film becomes too rough, and problems may occur in various processes in the subsequent steps. Moreover, by using in the said range, haze is restrained low and it is easy to ensure transparency as the whole film.

  Further, the particle content in the polyester layer is preferably less than 5% by weight, more preferably in the range of 0.0003 to 1% by weight, and still more preferably in the range of 0.0005 to 0.5% by weight. When there are no or few particles, the transparency of the film becomes high and the film becomes a good film, but the slipperiness may be insufficient. There are cases where improvement is required. In addition, when the particle content is high, haze increases and lacks transparency. For example, during various inspections, defects such as difficulty of defect inspection for foreign matters may occur.

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 addition to the above-mentioned particles, conventionally known UV absorbers, antioxidants, antistatic agents, thermal stabilizers, lubricants, dyes, pigments, etc. may be added to the polyester film in the present invention as necessary. Can do.

  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 it is preferably 10 to 350 μm, more preferably 15 to 200 μm.

  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, the polyester raw material described above is first 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.

  In the present invention, the simultaneous biaxial stretching method can be adopted for the production of the polyester film constituting the laminated polyester film. 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, coating is performed on either an unstretched sheet obtained by melting and rapid cooling, or a stretched uniaxially stretched film.

  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 particular, it is preferable because the release performance after heat treatment is more stable.

  In the present invention, it is an essential requirement to have a coating layer formed from an aqueous coating solution containing a polyether group-containing silicone and a crosslinking agent.

  The coating layer in the present invention is provided for use as a good release film in applications such as adhesive separators used for various tapes, ceramic production, various surface protection films, polarizing plate production, etc. It is what

  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, dispersibility will worsen, and conversely too much, durability and mold release performance will 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.

  In order to improve the strength and mold release performance of the coating layer (particularly, the mold release performance after heating or solvent treatment), a crosslinking agent is also used 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. Depending on the material system to be used, when two or more types are used in combination, for example, when one type of crosslinking agent is a polymer type crosslinking agent, the mold release performance may be improved.

  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.

  For the formation of the coating layer, a polyether group-containing silicone or a polymer other than a polymer type crosslinking agent is used in combination from the viewpoints of the appearance of the coating layer, stabilization of the mold release performance, adhesion to the polyester film of the base material, etc. It is also preferable.

  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%.

  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.

  Further, in the range not impairing the gist of the present invention, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are formed as necessary for forming the coating layer. It is also possible to use a foaming agent, a dye, a pigment 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 95% by weight, preferably 8 to 80% by weight, more preferably 10 to 70% by weight, Preferably it is the range of 15-60 weight%. When it is out of the above range, the release performance may be deteriorated.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the ratio of the crosslinking agent is usually 1 to 90% by weight, preferably 2 to 80% by weight, more preferably 5 to 70% by weight, and still more preferably 8%. It is in the range of ˜50% by weight. When it is out of the above range, the coating film strength and the release performance may be deteriorated.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the ratio of the polymer other than the polyether group-containing silicone is usually 95% by weight or less, preferably 5 to 90% by weight, more preferably 10 to 70% by weight. More preferably, it is in the range of 15 to 55% by weight. By using it in the above-mentioned range, it is easy to ensure a good coating appearance, adhesion with a polyester film as a substrate, and various release characteristics.

  In the polyester film of the present invention, various coating layers can be provided on the side opposite to the coating layer containing the polyether group-containing silicone. For example, an easy adhesion layer for providing a functional layer, an antistatic layer for preventing dust adhesion, and the like can be used.

  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. 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 0.2 μm. Range. When the film thickness is out of the above range, the appearance of the coating may be deteriorated or the release performance may be deteriorated.

  In the film of the present invention, as a method for forming the coating layer, for example, gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze Conventionally known coating methods such as coating, impregnation coating, kiss coating, spray coating, calendar coating, extrusion coating, etc. 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.

  Although the haze of the polyester film of the present invention is not particularly limited, for example, when used for strict inspections such as polarizing plates, transmission of inspection light is important for 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 the adhesive tape is preferably 200 mN / cm or less, more preferably 100 mN / cm. Hereinafter, it is more preferably in the range of 50 mN / cm or less, particularly preferably 40 mN / cm or less. By setting the amount within the above range, the peeling operation becomes easy.

  As the mold release performance of the coating layer, the peel force after heating to the adhesive tape is preferably 1000 mN / cm or less, more preferably 300 mN / cm or less, still more preferably 100 mN / cm or less, and particularly preferably 40 mN / cm or less. . By setting it as the said range, it becomes possible to peel the material which comes on an application layer well even after heat processing.

  As the mold release performance of the coating layer, the peeling force after solvent (toluene) treatment on the adhesive tape is preferably 1000 mN / cm or less, more preferably 300 mN / cm or less, still more preferably 100 mN / cm or less, and particularly preferably 40 mN / cm. cm or less. By setting it as the said range, it becomes possible to peel the material which comes on an application layer well even after solvent processing.

  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 Adhesive tape (“No. 502” manufactured by Nitto Denko Co., Ltd.) 5 cm in width is applied to the surface of the coating layer by one reciprocating press with a 2 kg rubber roller to room temperature The peel strength after standing 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) Method of measuring peel force after heating of coating layer After pressure-bonding a pressure sensitive adhesive tape (“No. 502” manufactured by Nitto Denko Corporation) 5 cm wide with a 2 kg rubber roller on the surface of the coating layer, oven at 100 ° C. The inside was heated for 1 hr. Thereafter, the peel force after standing 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.

(8) Measuring method of peeling force after solvent (toluene) treatment of coating layer The surface of the coating layer is reciprocated 10 times with a load of 700 g using a rubbing tester with a toluene impregnated becot. After air-drying, the peel force after one-way pressure-bonding of a pressure-sensitive adhesive tape (“No. 502” manufactured by Nitto Denko Corporation) with a 2 kg rubber roller to the surface of the coating layer 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.

(9) Strength evaluation method of coating layer The surface of the coating layer of the laminated polyester film is rubbed strongly three times with the belly of the finger, and when peeling of the coating layer is not observed, peeling of the coating layer is seen slightly and slightly whitish The case where it becomes becomes (triangle | delta), peeling of the coating layer was seen and the case where it became white was set as x.

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. 0.63 polyester (A) 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 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.

Melamine compound: (IIA) hexamethoxymethylol melamine

・ Oxazoline compounds: (IIB)
Acrylic polymer having an oxazoline group and a polyalkylene oxide chain Epocross (Oxazoline group amount = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)
Epoxy compound: (IIC) polyglycerol polyglycidyl ether

・ Isocyanate compounds: (IID)
1000 parts of hexamethylene diisocyanate was stirred at 60 ° C., and 0.1 part of tetramethylammonium capryate was added as a catalyst. After 4 hours, 0.2 part of phosphoric acid was added to stop the reaction, and an isocyanurate type polyisocyanate composition was obtained. 100 parts of the obtained isocyanurate type polyisocyanate composition, 42.3 parts of methoxypolyethylene glycol having a number average molecular weight of 400, and 29.5 parts of propylene glycol monomethyl ether acetate were charged and maintained at 80 ° C. for 7 hours. Thereafter, the reaction solution temperature was kept at 60 ° C., 35.8 parts of methyl isobutanoyl acetate, 32.2 parts of diethyl malonate, and 0.88 part of 28% methanol solution of sodium methoxide were added and kept for 4 hours. Block polyisocyanate obtained by adding 58.9 parts of n-butanol, maintaining the reaction solution temperature at 80 ° C. for 2 hours, and then adding 0.86 part of 2-ethylhexyl acid phosphate.

・ Isocyanate compounds: (IIE)
158 parts by weight of hexamethylene diisocyanate trimer, 26 parts by weight of methoxypolyethylene glycol (OH value = 81 mg KOH / g), 27.8 parts by weight of diethyl diethylene glycol and 0.001 part by weight of dioctyltin laurate were reacted at 85 ° C. Thereafter, the mixture was allowed to cool, and 66 parts by weight of methyl ethyl ketone oxime was added dropwise to react. Subsequently, 115 parts by weight of 1,6-hexamethylenediol-based polycarbonate diol (OH value = 56 mgKOH / g), 1.2 parts by weight of trimethylolpropane (OH value = 1254 mgKOH / g), dimethylolpropionic acid (OH value = 837 mgKOH) / G) 7.6 parts by weight and 50 parts by weight of dimethyldipropylene glycol were added, and after stirring, 40.3 parts by weight of isophorone diisocyanate was added and reacted. After allowing to cool, 8.2 parts by weight of hexamethylene diisocyanate trimer was added, and after stirring, 5.8 parts by weight of triethylamine was added and stirred. A block isocyanate compound obtained by dropping 450 parts by weight of water into this mixed solution and dropping and stirring 21 parts by weight of a 15% aqueous diethylenetriamine solution.

Silane coupling compound: (IIF) 3-glycidoxypropyltriethoxysilane Carbodiimide compound: (IIG)
Polycarbodiimide compound Carbodilite (carbodiimide equivalent = 600, manufactured by Nisshinbo Co., Ltd.)

・ Polyester resin: (III)
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%)

-Silicone dispersant: (IV) Sodium dodecylbenzenesulfonate Although described in the item of silicone compound, the silicone compound and the dispersant are described separately to clearly indicate the components in the coating layer. The same applies to Table 1.

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 0.05 μm, guiding to a tenter, drying at 95 ° C. for 10 seconds, stretching in the transverse direction by 4.3 times at 120 ° C., and performing heat treatment 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 finished polyester film was evaluated, the normal peel strength by the adhesive tape was as low as 28 mN / cm, and the release performance was good. The properties of this film are shown in Table 2 below.

Examples 2 to 20:
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. As shown in Table 2, the finished polyester film had a low peel force with the adhesive tape and a good release performance.

Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except having not provided the application layer, and obtained the polyester film. When the completed polyester film was evaluated, as shown in Table 2 below, the peel strength by the adhesive tape was high and the release performance was poor.

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. As shown in Table 2, the completed polyester film had good peel strength with the adhesive tape, and the normal peel strength was low and good, but the peel strength after heating and the solvent treatment peel strength were high, and the release performance was not good. .

  The film of the present invention is suitably used for applications that require good release performance, for example, for various tapes, for ceramic production, for various surface protection films, for adhesive separators used for polarizing plate production, etc. can do.

Claims (3)

It has a coating layer formed from an aqueous coating solution containing at least one crosslinking agent selected from polyether group-containing silicone and melamine compounds, oxazoline compounds, epoxy compounds, and isocyanate compounds on at least one side of the polyester film. A laminated polyester film characterized. The laminated polyester film according to claim 1, wherein the coating layer is formed by stretching in at least one direction. The laminated polyester film according to claim 1 or 2, wherein after the adhesive tape is applied to the surface of the coating layer, the peel strength after treatment for 1 hour at 100 ° C is 1000 mN / cm or less.