JP6551303B2 - Laminated polyester film - Google Patents

Description

  The present invention relates to a laminated polyester film, and has few fish eyes, for example, as a surface protection film for preventing damage or adhesion of dirt during transportation, storage or processing of resin plates, metal plates, etc. The present invention relates to a laminated polyester film that is excellent in mechanical strength and heat resistance, has little precipitation of an ester cyclic trimer even after heat treatment, and has good adhesive properties.

  Conventionally, when transporting, storing and processing resin plates, metal plates, glass plates, etc., preventing scratches and dirt, and scratching when processing components used in electronic fields such as liquid crystal panels and polarizing plates Wide range of surface protection films for applications such as prevention of dust and dirt, prevention of dirt and dirt during transportation and storage of automobiles, protection of automobile coating from acid rain, and protection during plating and etching of flexible printed circuit boards It is used.

  These surface protection films have appropriate adhesion to the adherend during transportation, storage, processing, etc. of various adherends such as resin plates, metal plates, and glass plates. It is required that the surface of the adherend be protected by adhering to the surface of the adherend and easily peeled off after the end of the purpose. In order to overcome these problems, proposals have been made to use polyolefin-based films for surface protection (Patent Documents 1 and 2).

  However, since a polyolefin-based film is used as the surface protective film substrate, it is not possible to remove defects caused by gel-like materials and deteriorated products, which are generally called fisheye, For example, when inspecting an adherend in a state where the surface protective film is bonded, there is a problem that it becomes an obstacle such as detecting a defect of the surface protective film.

  In addition, as a base material for the surface protection film, a film having a certain degree of mechanical strength is required so that the base material is not stretched due to tension during various processing such as bonding to an adherend. However, since polyolefin films generally have poor mechanical strength, they have the disadvantage of being unsuitable for high-tension processing due to increasing the processing speed in order to emphasize productivity.

  Furthermore, even when the processing temperature is raised to improve the processing speed and various characteristics, etc., the polyolefin-based film is not excellent in the shrinkage stability due to heat, so the dimensional stability is poor. Therefore, there is a demand for a film that has little thermal deformation even when processed at high temperature and has excellent dimensional stability.

Japanese Patent Laid-Open No. 5-98219 Japanese Patent Application Publication No. 2007-270005

  The present invention has been made in view of the above circumstances, and the problem to be solved is that there are few fish eyes used for various surface protection films and the like, and the mechanical strength and heat resistance are excellent. An object of the present invention is to provide a laminated polyester film having a good adhesion property with less precipitation of a polymer.

  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 has a functional layer containing a compound derived from a crosslinking agent on at least one surface of a polyester film, and an adhesive layer containing a resin having a glass transition temperature of 0 ° C. or less on the functional layer. A functional layer containing a compound derived from a crosslinking agent is provided on at least one surface of a laminated polyester film characterized by the features of the invention, and a resin having a glass transition temperature of 0 ° C. or less is then provided on the functional layer. After providing an application layer, it exists in the manufacturing method of the laminated polyester film characterized by forming the adhesion layer by extending | stretching the said application layer at least to one direction.

  According to the laminated polyester film of the present invention, as various surface protective films, there are few fish eyes, excellent mechanical strength and heat resistance, little precipitation of ester cyclic trimer after heat treatment, and good adhesive properties. It can provide you with high industrial value.

  We believe that it is necessary to make major changes to the base material of the base film in order to reduce the fisheye, improve mechanical strength and improve heat resistance, which is the problem, and as a result of various studies, it differs significantly from conventionally used polyolefin materials It has been found that this can be achieved by using polyester based materials. However, by greatly changing the material system of the base film, the adhesive properties are greatly lowered, which cannot be achieved with a general polyester film. Then, improvement was aimed at by providing an adhesion layer on a substrate film. However, when the polyester film is used as the substrate film while continuing the investigation, the oligomer (low molecular weight component of the polyester, particularly the ester cyclic trimer) contained in the polyester film is subjected to the heat treatment or aging. Therefore, the present invention has been achieved by improving the defects.

  The polyester used may be a homopolyester or a copolyester. When it consists of homo polyesters, what is obtained by polycondensing aromatic dicarboxylic acid and aliphatic glycol is 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. A polyethylene terephthalate etc. are illustrated as a typical polyester. On the other hand, examples of the dicarboxylic acid component of the copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (for example, p-oxybenzoic acid). 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 the heat resistance (dimensional stability by heating) be high, and for that purpose, it may be preferable that the amount of the copolymerized polyester component be small. Specifically, the proportion of the monomer forming the copolyester in the polyester film is usually in the range of 10 mol% or less, 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 end up. In view of mechanical strength and heat resistance, a more preferable form of polyester is more preferably a film formed from polyethylene terephthalate or polyethylene naphthalate, which is polymerized from terephthalic acid and ethylene glycol, 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. Is preferable because the transparency of the 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 usually 50 ppm or less, preferably 1 to 20 ppm, 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 up or sufficient strength can not 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 usually in the range of 1 to 300 ppm, preferably 3 to 200 ppm, more preferably 5 to 100 ppm, based on 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.

  The polyester film may have a single layer structure or a multilayer structure. In the case of a multilayer structure, the surface layer and the inner layer, or both the surface layer and each layer can be different polyester layers depending on the purpose, so that a multilayer structure of two or more layers can be provided, and each layer can be characterized to be multifunctional. Is preferred.

  In order to suppress the precipitation amount of the ester cyclic trimer after heat treatment or after aging, it is preferable that the ester cyclic trimer has a polyester layer of 0.7% by weight or less. Therefore, the method of manufacturing a film from polyester with little content of ester cyclic trimer as a raw material is mentioned. Various known methods can be used as a method for producing a polyester having a low ester cyclic trimer content. Examples thereof include a method of solid-phase polymerization after polyester production.

  By designing a layer using a polyester material having a polyester film with three or more layers and having a low content of ester cyclic trimers as the outermost polyester layer of the polyester film, ester cyclic three such as after heat treatment or after aging The method of suppressing the precipitation amount of a monomer is mentioned.

  Although the content of the ester cyclic trimer contained in the polyester film is about 1% by weight in a general production method, the content of the ester cyclic trimer from the viewpoint of preventing precipitation of the ester cyclic trimer Preferably has a polyester layer of at most 0.7 wt%, more preferably at most 0.6 wt%. In the case of having a polyester layer formed of a polyester having a content of ester cyclic trimer of 0.7% by weight or less, the effect of preventing precipitation of the ester cyclic trimer on the film surface is particularly highly exhibited.

  The polyester used for forming a polyester layer having an ester cyclic trimer of 0.7% by weight or less preferably uses a polyester raw material having a low content of ester cyclic trimer, and the ester cyclic trimer contained The amount is preferably 0.7 wt% or less, more preferably 0.6 wt% or less, still more preferably 0.5 wt% or less. By using it in the above-mentioned range, it becomes possible to more effectively suppress the precipitation amount of the ester cyclic trimer after heat treatment or after aging.

  The polyester layer having an ester cyclic trimer of 0.7% by weight or less comprises a polyester layer formed of a polyester having an ester cyclic trimer content of 0.7% by weight or less and 70% by weight or more It is preferably formed of a polyester layer formed of polyester which is preferably 80% by weight or more. When the polyester layer is formed from a polyester having 0.7% by weight or less of the polyester and 70% by weight or more, the effect of preventing the precipitation of the ester cyclic trimer on the film surface after heat treatment or after aging is highly exhibited. It becomes possible.

  When the polyester film has a multilayer structure, it is preferred that at least one layer of the polyester film, particularly the outermost layer of the polyester film, have a polyester layer having an ester cyclic trimer content of 0.7% by weight or less. It is preferable from the viewpoint of preventing precipitation of a monomer. In addition, from the viewpoint of preventing the precipitation of the ester cyclic trimer to a higher degree, the content of the ester cyclic trimer in all polyester layers is more preferably 0.7% by weight or less. .

  In addition, the thicker the film thickness of the polyester layer having an ester cyclic trimer content of 0.7% by weight or less, the more effectively the precipitation of the ester cyclic trimer from the polyester film is suppressed. The film thickness of the 0.7% by weight or less polyester layer is preferably thicker, preferably 2 μm or more, more preferably 3 μm or more, and particularly preferably 4 μm or more. The amount of precipitation of the ester cyclic trimer is most suppressed by setting the content of the ester cyclic trimer to 0.7% by weight or less in all layers. When the film thickness of the 0.7% by weight or less polyester layer is 2 μm or more, the effect of preventing the precipitation of the ester cyclic trimer on the film surface after heat treatment or after aging can be exhibited to a high degree.

  In the polyester layer, particles can be blended for the purpose of imparting slipperiness, preventing generation of scratches in each step, and improving anti-blocking properties. In the case of blending particles, the type of particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and as specific examples, 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 in which a part of a metal compound such as a catalyst is precipitated and finely dispersed can also be used in the polyester production process. 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 usually in the range of 10 μm or less, preferably 0.01 to 5 μm, more preferably 0.01 to 3 μm. When the average particle size exceeds 10 μm, there may be a concern that the film may be impaired due to the decrease in transparency.

  Furthermore, the content of particles in the polyester layer is generally not more than 5% by weight, preferably in the range of 0.0003 to 3% by weight, and more preferably 0, although it is not general because there is also a balance with the average particle diameter of the particles. It is in the range of .0005 to 1% by weight. When the particle content is more than 5% by weight, problems such as the dropout of the particles and the decrease in the transparency of the film may be concerned. When there are no particles or few particles, the slipperiness may be insufficient. Therefore, some measures such as improvement of the slipperiness may be required by putting the particles in the adhesive layer.

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 needed.

  It does not specifically limit as method to add particle | grains in a polyester layer, A conventionally well-known method can be employ | 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 ultraviolet absorbers, antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments and the like can be added to the polyester film, as required.

  The thickness of the polyester film is not particularly limited as long as it can form a film as a film, but is usually 2 to 350 μm, preferably 5 to 200 μm, more preferably 8 to 75 μm.

  Although the production example of the film will be specifically described, it is not limited to the following production example, and a generally known film forming method can be adopted. Generally, the resin is melted, sheeted, and stretched for the purpose of increasing the strength, etc., to form a film. For example, when producing a biaxially stretched polyester film, first, a polyester raw material is melt extruded from a die using an extruder, and the molten sheet is cooled and solidified by a cooling roll to obtain an unstretched sheet. In this case, in order to improve the planarity of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and the electrostatic application adhesion method or the 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 orthogonal to the first stretching direction at 70 to 170 ° C., usually at a stretching ratio of 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing a heat treatment usually 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.

  A simultaneous biaxial stretching method can also 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 usually 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in area ratio. 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 adopting the above-described stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be adopted.

  Next, the formation of the functional layer and the adhesive layer constituting the laminated polyester film will be described. Examples of the method of forming the functional layer and the adhesive layer include methods such as coating, transfer, and lamination. Considering the ease of forming the adhesive layer, it is preferable to form it by coating.

  The coating method may be provided by in-line coating performed in the process of film production, or may be provided by off-line coating, which coats the film once produced, outside the system. More preferably, it is formed by in-line coating.

  Specifically, in-line coating is a method in which coating is performed at any stage from melt extrusion of a resin forming a film to stretching after heat setting and winding. Usually, the unstretched sheet obtained by melting and quenching, the stretched uniaxially stretched film, the biaxially stretched film before heat setting, and the film after heat setting and before winding are coated. Although not limited to the following, for example, in the case of performing sequential biaxial stretching, as a preferred example, a functional layer formed of a coating solution containing a crosslinking agent is formed on an unstretched film, and then a longitudinal direction Direction), a uniaxially stretched film is formed, and a coating solution containing a resin having a glass transition point of 0 ° C. or less is applied thereon, and then stretched in the transverse direction to form an adhesive layer. According to such a method, film formation and the formation of the functional layer and the adhesive layer can be performed at the same time, so that there is a merit in manufacturing cost, and the thickness of the functional layer and the adhesive layer is stretched in order to perform stretching after coating. It can also be changed according to the magnification, and thin film coating can be performed more easily than off-line coating.

  Moreover, by providing a functional layer or an adhesive layer on the film before stretching, the functional layer or the adhesive layer can be stretched together with the base film, thereby firmly attaching the functional layer or the adhesive layer to the base film. be able to. 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 sex.

  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 functional layer and the adhesive layer is improved, and the functional layer, the adhesive layer, and the base film are made stronger. In addition, it can be a strong functional layer or an adhesive layer. In particular, it is very effective for reacting a crosslinking agent.

  According to the above-mentioned process by in-line coating, the film size does not change greatly depending on whether or not the adhesive layer is formed, and the risk of scratches and adhesion of foreign substances does not change greatly depending on whether or not the adhesive layer is formed. This is a great advantage over one extra offline coating. Furthermore, as a result of various studies, it has been found that in-line coating has the advantage of reducing adhesive residue, which is a transfer of components of the adhesive layer when the film of the present invention is bonded to an adherend. The It is considered that this can be heat-treated at a high temperature which can not be obtained by the off-line coating, and the adhesive layer and the base film (functional layer) are more firmly adhered.

  In the present invention, at least one surface of the polyester film has a functional layer containing a compound derived from a crosslinking agent, and further has an adhesive layer containing a resin having a glass transition temperature of 0 ° C. or less on the functional layer. It is an essential requirement.

  The functional layer is mainly provided to enhance the precipitation preventing effect of the ester cyclic trimer by heating. In particular, it can be an effective means when it is used as a protective film in an application which is severe to process contamination, an application which does not like whitening by heating, or an application which is severe in inspection, for example, an optical member such as a polarizing plate.

  There is no restriction | limiting in particular as a crosslinking agent contained in a functional layer, It is possible to use a conventionally well-known crosslinking agent. Examples include melamine compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, aziridine compounds, and the like. Among these, from the viewpoint of preventing precipitation of the ester cyclic trimer by heating, a melamine compound, an oxazoline compound, and an epoxy compound are preferable, and a melamine compound is more preferable.

In addition, any one of these crosslinking agents may be used, and it is also preferable to use two or more kinds of crosslinking agents in combination. In particular, from the viewpoint of preventing precipitation of the ester cyclic trimer by heating, two or more types of combined use is preferable, and combinations of a melamine compound and an oxazoline compound, a melamine compound and an epoxy compound, and an oxazoline compound and an epoxy compound are good. More preferably, the melamine compound, the oxazoline compound, and the epoxy compound are used in combination.

  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 etc. are used suitably. 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. Considering the reactivity with various compounds, it is preferable that the melamine compound contains a hydroxyl group. Furthermore, a product obtained by co-condensing urea or the like with part of melamine can also be used, and a catalyst can also 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, Examples thereof include 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like, and a mixture of one or more of these can be used. Among these, 2-isopropenyl-2-oxazoline is industrially easily available and suitable. The other monomer is not particularly limited as long as it is a monomer copolymerizable with the addition polymerizable oxazoline group-containing monomer. For example, alkyl (meth) acrylate (as alkyl group, methyl group, ethyl group, n-propyl group, 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 ( Meta) 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 amount of the oxazoline group of the oxazoline compound is usually in the range of 0.5 to 10 mmol / g, preferably 1 to 10 mmol / g, more preferably 3 to 9 mmol / g, and further preferably 5 to 8 mmol / g. By using in the above range, durability is improved, and it is effective for preventing precipitation of an ester cyclic trimer on the film surface by heating.

  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 polyglycidyl ether and diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, Examples of tetramethylene glycol diglycidyl ether and monoepoxy compound include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and as a glycidyl amine compound, N, N, N ′, N′-tetraglycidyl-m-xylyl. Examples include range amine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  Among these, polyether-based epoxy compounds are preferable from the viewpoint that the amount of ester cyclic trimer deposited on the film surface by heating is small. Moreover, as an amount of an epoxy group, a polyepoxy compound which is a trifunctional or higher polyfunctional than a bifunctional one is preferable.

  An isocyanate type compound is a compound which has an isocyanate derivative structure represented by isocyanate or block 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 isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, aliphatic isocyanate such as hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), isopropylidene dicyclohexyldiisocyanate 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 of two or more. 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 dimethyl malonate, diethyl malonate, methyl isobutanoyl acetate, 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, from the viewpoint of being effective in reducing the migration of the adhesive layer to the adherend described later, an isocyanate compound blocked by an active methylene compound is preferable.

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

  A carbodiimide type compound is a compound which has a carbodiimide or one or more carbodiimide derivative structures in a molecule | numerator. The polycarbodiimide type compound which has 2 or more in a molecule | numerator is more preferable for the strength etc. of a more favorable adhesive layer.

  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 Methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, dicyclohexylmethane diisocyanate and the like can be mentioned.

  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.

  A silane coupling compound is an organosilicon compound having an organic functional group and a hydrolysis group such as an alkoxy group in one molecule. For example, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4- Epoxy-containing compounds such as epoxycyclohexyl) ethyltrimethoxysilane, vinyl-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane, styryl-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, etc. (Meth) acrylic group-containing compound, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl)- 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N Amino group-containing compounds such as-(1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, tris (trimethoxysilylpropyl) Isocyanurate, tris (triethoxysilylpropyl) i Isocyanurate group-containing compounds such as cyanurate, mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, etc. Be

  Among the above compounds, from the viewpoint of maintaining the strength and adhesive strength of the adhesive layer, epoxy group-containing silane coupling compounds, double bond-containing silane coupling compounds such as vinyl groups and (meth) acryl groups, amino group-containing silane couplings Compounds are more preferred.

  In addition, these crosslinking agents are used by the design which is made to react in a drying process and a film forming process, and to improve the performance of a functional layer. In the finished functional layer, unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof (compounds derived from the crosslinking agent) are present.

  Further, in the formation of the functional layer, it is also possible to use a polymer in combination in order to improve the appearance, improve the transparency, and improve the adhesion with the adhesive layer. Specific examples of the polymer include polyvinyl (polyvinyl alcohol, etc.), polyester resin, acrylic resin, urethane resin, polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches and the like. Among these, polyvinyl (polyvinyl alcohol and the like), polyester resin, acrylic resin and urethane resin are suitably used, and polyvinyl is particularly preferable, and polyvinyl alcohol is preferable among them. However, depending on the composition of the functional layer, the amount of precipitation of the ester cyclic trimer on the film surface by heat treatment may increase, so careful handling is necessary.

  As polyvinyl alcohol, it has a polyvinyl alcohol part, For example, conventionally well-known polyvinyl alcohol can be used including the modified compound 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. If the degree of polymerization is less than 100, the water resistance may be reduced. Further, the degree of saponification of polyvinyl alcohol is not particularly limited, but is usually a saponified polyvinyl acetate having a range of 40 mol% or more, preferably 60 mol% or more, more preferably 70 to 99.9 mol%. .

  Further, in order to prevent precipitation of the ester cyclic trimer on the film surface by heating, it is one of preferred modes to use a compound containing an ammonium group in combination. As the compound containing an ammonium group, conventionally known materials can be used, and examples thereof include aliphatic amines, alicyclic amines, and ammonium amines of aromatic amines. The compound having an ammonium group is preferably a compound having a polymer type ammonium group, and the ammonium group is not a counter ion but a structure incorporated into the main chain or side chain of the polymer. Is preferred. 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 may be used as a polymer compound having an ammonium group, and it is preferably used. As the polymer, a monomer containing a precursor of an ammonium group such as an addition polymerizable ammonium group or an amine may be polymerized alone, or a copolymer of a monomer containing these and another monomer is used. May be

  The functional layer may contain particles for the purpose of blocking and improving slipperiness. The average particle diameter is preferably in the range of 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.2 μm or less from the viewpoint of film transparency. The lower limit is preferably in the range of 0.01 μm or more, more preferably 0.03 μm or more in order to improve the slipperiness more effectively. Specific examples of the particles include silica, alumina, kaolin, calcium carbonate, and organic particles. Among them, silica is preferable from the viewpoint of transparency.

  A conventionally known resin can be used as a resin having a glass transition point of 0 ° C. or less contained in the adhesive layer. Specific examples of the resin include a polyester resin, an acrylic resin, a urethane resin, a polyvinyl resin (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.) and the like. Acrylic resins and urethane resins are preferable, and polyester resins and acrylic resins are more preferable from the viewpoint of strength of adhesive properties, and polyester resins are further preferable because they have high adhesive strength to various adherends. In consideration of the reusability of the film, polyester resins and acrylic resins are preferred, and when the substrate is a polyester film, the polyester resin exhibits little change with time when adhesion to the substrate is considered. Acrylic resins are most preferred when considered. Furthermore, when the transferability of the components of the pressure-sensitive adhesive layer to the adherend is taken into consideration, it has also been found that an acrylic resin has a lower transferability and is preferable to a polyester resin.

  With polyester resin, what consists of a polyvalent carboxylic acid and a polyvalent hydroxy compound as follows as a main structural component is mentioned, for example. 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 -Naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutar Acids, succinic acids, trimellitic acids, trimesic acids, pyromellitic acids, trimellitic anhydrides, phthalic anhydrides, p-hydroxybenzoic acids, trimellitic acid monopotassium salts and their ester-forming derivatives can be used. And ethylene as polyvalent hydroxy compounds Recall, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanedio- , Neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol And polytetramethylene glycol, polytetramethylene oxide glycol, dimethylol propionic acid, glycerin, trimethylol propane, sodium dimethyl ethyl sulfonate, potassium dimethyl propionate and the like can be used. Among these compounds, one or more may be appropriately selected, and a polyester resin may be synthesized by a polycondensation reaction in a conventional manner.

  Among them, it is preferable to contain an aliphatic polyvalent carboxylic acid or an aliphatic polyvalent hydroxy compound as a constituent component in order to lower the glass transition point to 0 ° C. or lower. Generally, polyester resins are composed of polyvalent hydroxy compounds including aromatic polyvalent carboxylic acids and aliphatics, so in order to lower the glass transition point than common polyester resins, aliphatic polyvalent compounds are used. It is effective to contain a carboxylic acid. From the viewpoint of lowering the glass transition point, the aliphatic polycarboxylic acid preferably has a long carbon number, and usually has a carbon number of 6 or more (adipic acid), preferably a carbon number of 8 or more, more preferably 10 or more. And the upper limit of the preferred range is 20.

  In addition, the content of the aliphatic polyvalent carboxylic acid in the acid component in the polyester resin is usually 2 mol% or more, preferably 4 mol% or more, more preferably 6 mol% or more, from the viewpoint of improving adhesion properties. More preferably, it is 10 mol% or more, and the upper limit of a preferable range is 50 mol%.

  In order to lower the glass transition temperature in the aliphatic polyvalent hydroxy compound, the carbon number is preferably 4 or more (butanediol), and the content of the hydroxy component in the polyester resin is preferably 10 moles. % Or more, more preferably in the range of 30 mol% or more.

  In view of the suitability for in-line coating, it is preferable to use an aqueous system, and it is therefore preferable to contain a hydrophilic functional group, sulfonic acid, sulfonic acid salt, carboxylic acid or carboxylic acid salt, in the polyester resin. In particular, sulfonic acids and sulfonates are preferable, and in particular, sulfonates are preferable, in that the dispersibility in water is good. Among the sulfonates, metal sulfonates are more preferred.

  When using the above-mentioned sulfonic acid, sulfonate, carboxylic acid, carboxylate, the content in the acid component in the polyester resin is usually 0.1 to 10 mol%, preferably 0.2 to 8 mol%. Range. By using in the said range, the dispersibility to water becomes favorable.

  As an acid component in the polyester resin, considering the appearance of coating in in-line coating, adhesion and blocking to a film, and reduction of migration (adhesion residue) to an adherend when used as a surface protective film, It is preferable to contain a certain amount of aromatic polyvalent carboxylic acid. The proportion of the aromatic polyvalent carboxylic acid as the proportion in the acid component in the polyester resin is usually 30 mol% or more, preferably 50 mol% or more, more preferably 60 mol% or more, and the upper limit of the preferable range is 98 Mol%. Among aromatic polycarboxylic acids, a benzene ring structure such as terephthalic acid or isophthalic acid is more preferable than a naphthalene ring structure from the viewpoint of adhesive properties. Furthermore, in order to further improve the adhesive property, it is more preferable to use two or more kinds of aromatic polyvalent carboxylic acids in combination.

  As a glass transition point of the polyester resin for improving the adhesive properties, 0 ° C. or less is essential, preferably −10 ° C. or less, more preferably −20 ° C. or less, and the lower limit of the preferred range is − 60 ° C. It becomes easy to set it as the film which has the optimal adhesion characteristic by using in the said range.

An acrylic resin is a polymer which consists of a polymerizable monomer containing an acrylic type and a methacrylic type monomer (Hereafter, acrylic and a methacryl may be put together and it may be abbreviated as (meth) acrylic). These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers.
Also included are copolymers of these polymers with other polymers such as polyesters, polyurethanes and the like. For example, a block copolymer or a graft copolymer. Alternatively, it also includes a polyester solution, or a polymer obtained by polymerizing a polymerizable monomer in a polyester dispersion (in some cases, a mixture of polymers). 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, other polymer solutions, or polymers obtained by polymerizing polymerizable monomers in dispersion (in some cases, polymer mixtures) are also included. However, in consideration of adhesive properties and adhesive residue on the adherend, it should not contain other polymers such as polyester and polyurethane (polymerizable monomers containing carbon-carbon double bonds (whether homopolymers or copolymers) (Meth) acrylic resin composed only of (possible)) is preferable.

  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 such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate No (meta) acrylic Acid esters; various nitrogen-containing compounds such as (meth) acrylamide, diacetone acrylamide, N-methylolacrylamide or (meth) acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene Various vinyl esters such as vinyl propionate and vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane; phosphorus-containing vinyl monomers; And vinyl, various halogenated vinyls such as pyridene chloride; various conjugated dienes such as butadiene.

  In order to lower the glass transition point to 0 ° C. or lower, it is necessary to use a (meth) acrylic system having a glass transition point of the homopolymer of 0 ° C. or lower. For example, ethyl acrylate (glass transition point: −22 ° C.), n-propyl acrylate (glass transition point: −37 ° C.), isopropyl acrylate (glass transition point: −5 ° C.), normal butyl acrylate (glass transition point: −55 ° C.), normal hexyl acrylate (glass transition point: −57) ° C), 2-ethylhexyl acrylate (glass transition point: -70 ° C), normal octyl acrylate (glass transition point: -65 ° C), isooctyl acrylate (glass transition point: -83 ° C), normal nonyl acrylate (glass) Transition point: -63 ° C), normal nonyl methacrylate (glass transition point: -35 ° C), isono Acrylate (glass transition point: -82 ° C), normal decyl acrylate (glass transition point: -70 ° C), normal decyl methacrylate (glass transition point: -45 ° C), isodecyl acrylate (glass transition point: -55 ° C) , Isodecyl methacrylate (glass transition point: −41 ° C.), lauryl acrylate (glass transition point: −30 ° C.), lauryl methacrylate (glass transition point: −65 ° C.), tridecyl acrylate (glass transition point: −75 ° C.) And tridecyl methacrylate (glass transition temperature: −46 ° C.), isomystyryl acrylate (glass transition temperature: −56 ° C.), 2-hydroxyethyl acrylate (glass transition temperature: −15 ° C.) and the like.

  Among the above, the carbon number of the alkyl group is usually 4 or more, preferably 4 to 30, more preferably 4 to 20, and still more preferably 4 to 14 to improve the adhesion property The alkyl (meth) acrylate which is The (meth) acrylic resin which is mass-produced industrially and contains normal butyl acrylate and 2-ethylhexyl acrylate is optimal from the viewpoint of handleability and supply stability.

  The content of the (meth) acrylate unit having an alkyl group having 4 or more carbon atoms at the ester end in the (meth) acrylic resin is usually 20% by weight or more, preferably 35 to 99% by weight, more preferably 50 to 98 % By weight, more preferably 65 to 95% by weight, particularly preferably 75 to 90% by weight. The larger the content of the (meth) acrylate unit having an alkyl group having 4 or more carbon atoms at the ester end, the stronger the adhesion properties. Conversely, when the content is too small, the adhesive strength may not be sufficient.

  In the above (meth) acrylic resin, the content of the (meth) acrylate unit having a homopolymer having a glass transition point of 0 ° C. or less and an alkyl group having a carbon number of less than 4 at the ester end is usually 50% by weight or less Preferably it is 40 weight% or less, More preferably, it is 30 weight% or less range. By using in the said range, it becomes a favorable adhesion characteristic.

Further, from the viewpoint of reducing the migration of the adhesive component to the adherend, among the above, a compound having 2 or less carbon atoms at the ester end is preferable, or a compound having a cyclic structure is more preferable. Is a compound having 1 carbon atoms or an aromatic compound.
Specific examples thereof include methyl methacrylate, acrylonitrile, styrene and cyclohexyl acrylate as preferable compounds.

  The content of the compound unit having 2 or less carbon atoms at the ester end in the (meth) acrylic resin is usually 50% by weight or less, preferably 1 to 40% by weight, more preferably 3 to 30% %, More preferably 5 to 20% by weight. If the content of the unit is small, it is possible to impart an appropriate range of adhesive properties without greatly degrading the adhesive properties. Conversely, if the content is high, the content of the unit is greater on the adherend. It is possible to reduce the migration of the adhesive component. Therefore, if it is the said range, it will become easy to achieve the two objectives, adhesive characteristics and migration reduction.

  The content of the compound unit having a cyclic structure in the (meth) acrylic resin is usually 50% by weight or less, preferably 1 to 45% by weight, and more preferably 5 to 40% by weight. If the content of the unit is small, it is possible to impart an appropriate range of adhesive properties without greatly degrading the adhesive properties. Conversely, if the content is high, the content of the unit is greater on the adherend. It is possible to reduce the migration of the adhesive component. Therefore, if it is the said range, it will become easy to achieve two objectives, an adhesion characteristic and a transition reduction.

  From the viewpoint of adhesive properties, the content of a monomer having a glass transition point of 0 ° C. or less of a homopolymer as a monomer constituting the (meth) acrylic resin is usually 30% by weight or more as a ratio to the entire (meth) acrylic resin Preferably it is 45 weight% or more, More preferably, it is 60 weight% or more, More preferably, it is 70 weight% or more range. The upper limit of the preferred range is 99% by weight. Favorable adhesion characteristics are easy to be obtained by using in the said range.

  Moreover, as a glass transition point of the monomer whose homopolymer has a glass transition point of 0 ° C. or lower for improving the adhesive property, it is usually −20 ° C. or lower, preferably −30 ° C. or lower, more preferably −40 ° C. or lower, further Preferably it is -50 degrees C or less, and the minimum of a preferable range is -100 degreeC. By using it in the said range, it becomes easy to set it as the film which has moderate adhesive characteristics.

  Further, as the form of (meth) acrylic resin for further improving the adhesive property, the total content of normal butyl acrylate and 2-ethylhexyl acrylate in the (meth) acrylic resin is usually 30% by weight or more, The content is preferably 40% by weight or more, more preferably 50% by weight or more, still more preferably 60% by weight or more, particularly preferably 70% by weight or more, and the upper limit of the preferable range is 99% by weight. Although it depends on the composition of the (meth) acrylic resin to be used and the composition of the adhesive layer, 2-ethylhexyl is particularly desirable in order to eliminate the migration of the adhesive component to the adherend with a small amount of crosslinking agent. The acrylate content is usually 90% by weight or less, preferably 80% by weight or less.

  In consideration of application to in-line coating, etc., various hydrophilic functional groups can be introduced in order to obtain an aqueous (meth) acrylic resin. Preferred examples of the hydrophilic functional group include a carboxylic acid group, a carboxylic acid group, a sulfonic acid group, a sulfonic acid group, and a hydroxyl group. Among these, a carboxylic acid group, a carboxylic acid group, and a hydroxyl group are preferable from the viewpoint of water resistance.

  As the introduction of carboxylic acid, copolymerization of various carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid and citraconic acid can be mentioned. Among these, acrylic acid and methacrylic acid are preferred because effective water dispersion is possible.

  As the introduction of a hydroxyl group, various kinds such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate, etc. Copolymerizing a hydroxyl group containing monomer is mentioned. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable in consideration of industrial ease of handling.

  It is also possible to include a copolymer of an amino group-containing monomer such as dimethylaminoethyl (meth) acrylate or a copolymer of an epoxy group-containing monomer such as glycidyl (meth) acrylate as a crosslinking reactive group. is there. However, if the content is too large, the adhesive properties are affected, so an appropriate amount is required.

  The proportion of the hydrophilic functional group-containing monomer in the (meth) acrylic resin is usually in the range of 30% by weight or less, preferably 1 to 20% by weight, more preferably 2 to 15% by weight, still more preferably 3 to 10% by weight It is. By using in the said range, aqueous system development becomes easy.

  The glass transition point of the (meth) acrylic resin for improving the adhesive property is essentially 0 ° C. or less, preferably −10 ° C. or less, more preferably −20 ° C. or less, further preferably The lower limit of the preferable range is −80 ° C. It becomes easy to set it as the film which has the optimal adhesion characteristic by using in the said range. Moreover, when it is necessary to consider the reduction of migration of the adhesive component to the adherend, it is preferably in the range of -70 ° C or more, more preferably -60 ° C or more, and still more preferably -50 ° C or more.

  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 polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination of two or more.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. As polyhydric alcohols, 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-dimethylolheptane and the like can be mentioned. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate and the like. Polycarbonate polyols obtained from these reactions include, for example, poly (1,6-hexylene) carbonate, poly (3- (3) And methyl-1,5-pentylene) carbonate.

  From the viewpoint of improving adhesive properties, the chain alkyl chain is a polycarbonate polyol composed of a diol component that is usually in the range of 4 to 30, preferably 4 to 20, and more preferably 6 to 12, and is industrial. From the viewpoint of easy handling and supply stability, 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol The copolycarbonate polyol containing at least two selected diols is optimum.

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

  From the viewpoint of improving adhesion properties, monomers forming polyethers are aliphatic diols having a carbon number of usually 2 to 30, preferably 3 to 20, more preferably 4 to 12, and particularly linear aliphatic diols. Is a polyether polyol containing

  As polyester polyols, polyvalent carboxylic 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 Those obtained from the reaction of a diol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyl dialkanolamines, lactone diols, etc.), those having a derivative unit of a lactone compound such as polycaprolactone, etc. may be mentioned.

  Among the above-mentioned polyols, polycarbonate polyols and polyether polyols are more preferably used in consideration of the adhesive property, and polycarbonate 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 Methane diy Cyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination of two or more.

  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. Glycols such as glycol can be mentioned. Moreover, as a chain extender having two amino groups, for example, aromatic diamines such as tolylenediamine, xylylenediamine, diphenylmethanediamine, etc., 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, isopropylidenecyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1, 3-Bisaminomethylcyclohexa And alicyclic diamines, and the like.

  The urethane resin 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, a self-emulsification type in which ion groups are introduced into the structure of the urethane resin to make it ionomerized is preferable because it is excellent in the storage stability of the liquid and the water resistance and transparency of the obtained adhesive layer.

  Moreover, as an ionic group to introduce | transduce, although various things, such as a carboxyl group, a sulfonic acid, phosphoric acid, a phosphonic acid, a quaternary ammonium salt, are mentioned, a carboxyl group is preferable. As a method of introducing a carboxyl group into the urethane resin, various methods can be taken in each step 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, it is preferable to use a carboxyl group-containing diol and introduce a desired amount of carboxyl group depending on the amount of this component charged.

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. The carboxyl group is preferably in the form of a salt neutralized with ammonia, an amine, an alkali metal, an 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 is removed in the drying step after coating can be used as a crosslinking reaction point by another crosslinking agent. This makes it possible to further improve the durability, solvent resistance, water resistance, blocking resistance and the like of the adhesive layer obtained, as well as having excellent stability in the liquid state before coating.

  The glass transition point of the urethane resin for improving the adhesive properties is essentially 0 ° C. or less, preferably −10 ° C. or less, more preferably −20 ° C. or less, and still more preferably −30 ° C. It is the following range, and the lower limit of the preferred range is -80 ° C. It becomes easy to set it as the film which has the optimal adhesion characteristic by using in the said range.

  In addition, only 1 type may be used for the above-mentioned resin whose glass transition point is 0 degrees C or less, and 2 or more types may be used together. Preferred forms when two or more types are used in combination include a polyester resin and a urethane resin, a polyester resin and an acrylic resin, and a urethane resin and an acrylic resin.

  Moreover, it is also preferable to use a crosslinking agent together from the viewpoint of the strength of the adhesive layer. Although the investigation of the pressure-sensitive adhesive layer using a resin having a glass transition point of 0 ° C. or lower has been mainly conducted, it has been found in the examination that the pressure-sensitive adhesive component migrates to the adherend under severe conditions. As a result of various studies, it was also found that the use of a crosslinking agent together can improve the transfer of the adhesive layer to the adherend.

  As the crosslinking agent, conventionally known materials can be used, and compounds such as those used in the functional layer can be used. Examples include melamine compounds, isocyanate compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, aziridine compounds, and the like. Among them, melamine compounds, isocyanate compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, and silane coupling compounds are preferable, and melamine compounds and isocyanate compounds are preferable from the viewpoint that adhesive strength can be appropriately maintained and adjusted easily. A compound and an epoxy compound are more preferable, and an isocyanate compound and an epoxy compound are particularly preferable because a decrease in adhesive strength due to the combined use can be suppressed. In particular, from the viewpoint that migration to an adherend can be reduced, melamine compounds and isocyanate compounds are preferable, and among them, melamine compounds are particularly preferable. Furthermore, a melamine compound is particularly preferable from the viewpoint of the strength of the adhesive layer. In addition, one type of these crosslinking agents may be used, or two or more types may be used in combination.

  Depending on the configuration of the pressure-sensitive adhesive layer and the type of crosslinking agent, if the content of the crosslinking agent in the pressure-sensitive adhesive layer is excessive, the pressure-sensitive adhesive characteristics may be excessively lowered. Therefore, it is preferable to pay attention to the content in the adhesive layer.

  In addition, these crosslinking agents are used by the design which makes it react in a drying process or a film forming process, and improves the performance of the adhesion layer. In the completed pressure-sensitive adhesive layer, there are unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof (compounds derived from the crosslinking agent).

  In addition, glass transition from the viewpoints of appearance of adhesive layer, adjustment of adhesive strength, reinforcement of adhesive layer, adhesion to base film (functional layer), blocking resistance, and prevention of adhesion component migration to adherend It is also possible to use a resin whose point exceeds 0 ° C. in combination. A conventionally known material can be used as the resin having a glass transition point exceeding 0 ° C. Among them, polyester resins, acrylic resins, urethane resins and polyvinyls (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.) are preferable, and polyester resins, acrylic resins and urethanes in consideration of the appearance and adhesion of the adhesive layer. Resins selected from resins are preferred. However, depending on the method of use, there is a concern that the adhesive strength may be greatly reduced, and caution is required.

  Resins having a glass transition point exceeding 0 ° C. are used for the appearance of the adhesive layer, adjustment of adhesive strength, reinforcement of the adhesive layer, adhesion to the substrate film, improvement of blocking resistance, etc. There is also a concern that the adhesive strength may be greatly reduced, so caution is required.

  As a polyester resin as resin whose glass transition point exceeds 0 degreeC, the polyester resin containing an aromatic compound is preferable. In addition, the aromatic compound is preferably an aromatic polyvalent carboxylic acid from the viewpoint of adjustment of adhesive strength, etc., than the aromatic polyvalent hydroxy compound. The content of the aromatic polyvalent carboxylic acid is usually 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 90% by weight, as a proportion of the acid component in the polyester resin. %, And it is preferable from the viewpoint of adhesion control, blocking resistance and the like that it does not contain an aliphatic polyvalent carboxylic acid, particularly an aliphatic polyvalent carboxylic acid having 6 or more carbon atoms.

  Various urethanes can be used as the urethane resin as a resin having a glass transition temperature exceeding 0 ° C. Among them, urethanes by polyester polyols from the viewpoints of adjustment of adhesive strength, slipperiness, and blocking resistance. A resin is more preferable. The polyester polyols preferably contain an aromatic compound, and an aromatic polyvalent carboxylic acid is more preferable than an aromatic polyvalent hydroxy compound from the viewpoint of adjustment of adhesive strength and the like. The content of the aromatic polyvalent carboxylic acid as a proportion in the urethane resin is usually 5 to 80% by weight, preferably 15 to 65% by weight, and more preferably 20 to 50% by weight. By using it in the said range, it becomes easy to adjust the adhesive force and to improve the performance of blocking resistance.

  The glass transition temperature of the resin having a glass transition temperature exceeding 0 ° C. is usually in the range of 10 ° C. or more, preferably 20 ° C. or more, more preferably 30 ° C. or more, and the upper limit of the preferable range is 150 ° C. By setting it as the said range, it can adjust without dropping adhesive force too much, and it becomes easy to improve performance, such as slipperiness and blocking resistance.

  In forming the adhesive layer, it is also possible to use particles in combination for blocking, improving slipperiness and adjusting adhesive properties. However, care should be taken because the adhesive strength may decrease depending on the type of particles used. In order not to reduce the adhesive strength so much, the average particle diameter of the particles to be used is preferably 3 times or less of the thickness of the adhesive layer, more preferably 1.5 times or less, still more preferably 1.0 times or less And particularly preferably in the range of 0.8 times or less. In particular, when it is desired to exhibit the adhesive performance of the resin of the adhesive layer as it is, it may be preferable not to contain particles in the adhesive layer.

  A functional layer may be provided on the surface of the film opposite to the pressure-sensitive adhesive layer in order to impart various functions. For example, it is preferable to provide a release layer in order to reduce blocking of the film by the adhesive layer, or to prevent defects due to adhesion of dust around the film due to peeling charging of the film or frictional charging. Providing is also a preferred form. The functional layer may be provided by coating, may be provided by in-line coating, or may adopt off-line coating. In-line coating is preferably used from the viewpoint of stabilization such as manufacturing cost and mold release performance and antistatic performance by in-line heat treatment.

  For example, when a release functional layer is provided on the surface of the film opposite to the adhesive layer, the release agent contained in the release functional layer is not particularly limited, and a conventionally known release agent may be used. For example, long chain alkyl group-containing compounds, fluorine compounds, silicone compounds, waxes and the like can be mentioned.

  When an antistatic functional layer is provided on the surface of the film opposite to the adhesive layer, the antistatic agent contained in the antistatic functional layer is not particularly limited, and conventionally known antistatic agents can be used.

  The functional layer which may be provided on the side opposite to the adhesive layer of the film contains both the above-mentioned release agent and antistatic agent, and it is also a preferable embodiment to have an antistatic release function.

  In addition, antifoaming agents, coatability improvers, thickeners, organic lubricants, antistatic agents, ultraviolet light absorbers, if necessary, for the formation of the adhesive layer and the functional layer, as long as the gist of the present invention is not impaired. Antioxidants, foaming agents, dyes, pigments and the like can be used in combination.

  The total amount of the crosslinking agent as a ratio in the functional layer constituting the laminated polyester film is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, particularly preferably 70% by weight or more, Preferably it is the range of 85 weight% or more, and the whole quantity may be a crosslinking agent, ie, 100 weight%. By using in the said range, reduction of the precipitation amount of ester cyclic trimer is attained.

  When a melamine compound is selected as one of the cross-linking agents, the melamine compound is usually in the range of 10% by weight or more, preferably 15 to 90% by weight, more preferably 30 to 85% by weight as a ratio in the functional layer. . When using in the said range, the precipitation amount of ester cyclic trimer by heating can be suppressed effectively.

  When an oxazoline compound is selected as one of the crosslinking agents, the ratio of the oxazoline compound in the functional layer is usually 5% by weight or more, preferably 10 to 85% by weight, more preferably 15 to 70% by weight. . When using in the said range, the precipitation amount of ester cyclic trimer by heating can be suppressed effectively.

  When an epoxy compound is selected as one of the crosslinking agents, the proportion of the epoxy compound in the functional layer is usually 5% by weight or more, preferably 10 to 85% by weight, more preferably 15 to 70% by weight. . When using in the said range, the precipitation amount of ester cyclic trimer by heating can be suppressed effectively.

  When using a compound containing an ammonium group in the functional layer, the ratio in the functional layer is usually 5 to 70% by weight, preferably 10 to 60% by weight, more preferably 20 to 50% by weight It is. When using in the said range, the precipitation amount of ester cyclic trimer by heating can be suppressed.

When a polymer other than the compound containing an ammonium group is used in the functional layer, the proportion in the functional layer is usually 5 to 70% by weight, preferably 10 to 50% by weight. When using in the said range, the precipitation amount of the ester cyclic trimer by heating can be suppressed, and the external appearance of a functional layer will become favorable.

The resin having a glass transition temperature of 0 ° C. or less is usually 5% by weight or more, preferably 10 to 99.5% by weight, more preferably 30 to 98% by weight, as a ratio in the adhesive layer constituting the laminated polyester film. More preferably, it is in the range of 45 to 96% by weight, particularly preferably 55 to 94% by weight, and most preferably 70 to 90% by weight. By using in the said range, sufficient adhesive force is easy to be obtained, and it is easy to adjust adhesive force. If the content is too small, the adhesive strength may be reduced, and a device such as increasing the thickness of the adhesive layer may be required.
However, in order to increase the film thickness, in some cases the productivity may be adversely affected, for example, by lowering the line speed.

  As a ratio in the adhesive layer constituting the laminated polyester film, the crosslinking agent is usually 0.5 to 80% by weight, preferably 1 to 65% by weight, more preferably 3 to 50% by weight, still more preferably 5 to 40% %, Particularly preferably in the range of 8 to 25% by weight. By using in the said range, while improving the intensity | strength of an adhesion layer and the transfer to the adherend of an adhesion layer, it is easy to adjust adhesive force. If the content is too small, the transition to the adherend will increase, and if the content is too large, the adhesive strength may decrease, so it is necessary to take measures such as increasing the thickness of the adhesive layer. It may become. However, in order to increase the film thickness, care must be taken because the productivity may be adversely affected, for example, by reducing the line speed depending on the degree or circumstances.

  As a ratio in the adhesive layer constituting the laminated polyester film, the particles are usually 70% by weight or less, preferably 0.1 to 50% by weight, more preferably 0.5 to 30% by weight, and further preferably 1 to 20% by weight. % Range. By using in the said range, sufficient adhesion characteristic, blocking resistance property, and slipperiness are easy to be obtained.

  As a ratio in the adhesive layer constituting the laminated polyester film, the resin having a glass transition point exceeding 0 ° C. is usually 80% by weight or less, preferably 50% by weight or less, more preferably 30% by weight or less. By using in the said range, the external appearance of an adhesion layer, adjustment of adhesive force, reinforcement of an adhesion layer, adhesiveness with a base film, and the improvement of blocking resistance can be anticipated. If the content is too large, the adhesive strength is reduced, and thus it is sometimes necessary to devise such as increasing the thickness of the adhesive layer.

  The analysis of the components in the adhesive layer and the functional layer can be performed by analysis of TOF-SIMS, ESCA, fluorescent X-ray, IR, etc., for example.

  With respect to the formation of the adhesive layer and the functional layer, a solution or solution dispersion of the above-mentioned series of compounds and a solution having a solid content concentration adjusted to about 0.1 to 80% by weight is coated on a film It is preferred to produce a laminated polyester film. In particular, when provided by in-line coating, an aqueous solution or a water dispersion is more preferable. The coating solution may contain a small amount of an organic solvent for the purpose of improving the dispersibility in water, 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.

The film thickness (coating amount) of the functional layer is usually 0.001 to 1 g / m ² , preferably 0.01 to 0.5 g / m ² , more preferably 0.02, as the final film after drying and drawing. It is in the range of ˜0.2 g / m ² . By using the film thickness amount within the above range, the precipitation preventing performance and the appearance of the ester cyclic trimer by heating become good.

  The film thickness of the adhesive layer depends on the material used for the adhesive layer, so it cannot be said unconditionally. However, in order to adjust the adhesive force more appropriately, or to improve the blocking properties, the appearance of the adhesive layer, etc. It is 10 μm or less, preferably 1 nm to 4 μm, more preferably 10 nm to 1 μm, still more preferably 20 to 700 nm, and particularly preferably 30 to 400 nm. Moreover, in order to reduce especially the transfer of the adhesion component to a to-be-adhered body, the thinner one is preferable.

  A typical adhesive layer has a thick film thickness of several tens of μm, but in such a case, the adhesive in the adhesive layer sticks out when it is pasted to an adherend and molded or cut. May occur prominently.

  However, by adjusting the film thickness to the above-mentioned range, the protrusion can be minimized. This effect becomes better as the adhesive layer is thinner. In addition, the thinner the adhesive layer is, the smaller the absolute amount of the adhesive layer present on the film is, and the more effective the adhesive paste component is transferred to the adherend and the reduction in adhesive residue. In addition, when the film thickness is in the above-mentioned range, it can be seen that a moderate adhesive strength that is not too strong can be achieved, and when used for applications that require both adhesive performance and peeling performance to peel after bonding. In this case, the adhesion-peeling operation can be easily performed, and an optimum film can be obtained.

  The thinner the film thickness is, the more effective it is for blocking properties, and it is easy to manufacture when the adhesive layer is formed by in-line coating, but it is preferable if the film thickness is too thin. Since it may disappear, the use in the above-mentioned preferred range is preferred according to a use.

  The adhesive layer and the functional layer can be formed, for example, by gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze coating, impregnation Conventionally known coating methods such as coat, kiss coat, spray coat, calender coat, and extrusion coat can be used.

  The drying and curing conditions for forming the adhesive layer on the film are not particularly limited, but in the case of the method by coating, the drying of a solvent such as water used in the coating liquid is usually 70 to The temperature is 150 ° C., preferably 80 to 130 ° C., and more preferably 90 to 120 ° C. The drying time is, as a standard, 3 to 200 seconds, preferably 5 to 120 seconds. Moreover, in order to improve the intensity | strength of an adhesion layer, in a film manufacturing process, it is 150-270 degreeC normally, Preferably it is 170-230 degreeC, More preferably, it passes through the heat treatment process of the range of 180-210 degreeC. The time of the heat treatment step is, as a standard, in the range of 3 to 200 seconds, preferably 5 to 120 seconds.

  Moreover, you may use together heat processing and active energy ray irradiations, such as ultraviolet irradiation, as needed. The 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 adhesion of the adhesive layer to the polymethyl methacrylate plate is usually 1 to 5000 mN / cm, preferably 3 to 1000 mN / cm, more preferably 5 to 500 mN / cm, as measured by the measurement method described later. More preferably, it is in the range of 7 to 300 mN / cm, particularly preferably 10 to 100 mN / cm. By setting it as the said range, coexistence of adhesive performance and peeling performance which peels after bonding can be aimed at, and it becomes possible to set it as an optimal laminated body for various processes which perform adhesion-peeling operation. . Moreover, it becomes easy to make the blocking characteristic of a film favorable.

  As an index for precipitation of ester cyclic trimer by heating on the pressure-sensitive adhesive layer side, the film haze change amount in heat treatment (150 ° C., 90 minutes) is usually 1.5% or less, preferably 1.0% or less, more preferably It is 0.5% or less, more preferably 0.3% or less. If the haze change amount exceeds 1.5%, the amount of ester cyclic trimer precipitated is large, which may be inappropriate due to process contamination, a decrease in adhesive strength, and a decrease in visibility due to an increase in film haze. is there.

  The arithmetic average roughness (Sa) of the adhesive layer surface is preferably 50 nm or less, more preferably 30 nm or less, still more preferably 20 nm or less, particularly preferably 15 nm or less, and most preferably 10 nm or less. If Sa is too high, sufficient adhesive strength may not be exhibited. In addition, when Sa is too high, it may be necessary to adjust the film thickness of the adhesive layer to be thick in order to express the adhesive force, and adjustment of the adhesive force and reduction of migration of the adhesive component to the adherend are It can be difficult. The lower limit is not particularly limited, but the lower limit of the preferable range is 1 nm.

  Sa on the surface of the adhesive layer can be adjusted by designing the adhesive layer or designing the polyester film layer on the side in contact with the adhesive layer. When trying to adjust Sa in the design of the pressure-sensitive adhesive layer, it is necessary to increase the thickness of the pressure-sensitive adhesive layer and raise the hurdle in designing the pressure-sensitive adhesive force. Therefore, it is preferable to cope with the design of the polyester film layer.

  As a design of the polyester film layer on the adhesive layer side, the average particle diameter of the contained particles, the content of the particles, and the thickness of the polyester film layer are mainly mentioned as factors affecting Sa. Since the value of Sa is mainly determined by the interrelation between these factors, it is not possible to determine the value of Sa considering only one factor. However, as a guideline for adjustment, the average particle size of particles is usually 5 μm or less, preferably Is in the range of 3.5 μm or less. By using in the said range, it becomes easy to make Sa low.

  The amount of particles contained in the polyester film layer on the adhesive layer side is usually less than 0.30% by weight, preferably 0.15% by weight or less, more preferably 0.10% by weight or less, further preferably 0.08% by weight. The range is as follows. By using in the said range, it becomes easy to make Sa low.

  The thickness of the polyester film layer on the pressure-sensitive adhesive layer side is usually 0.5 to 10 μm, preferably 1 to 8 μm, more preferably 2 to 6 μm. By using in the said range, adjustment of content of particle | grains becomes easy, and adjustment of Sa also becomes easy.

  As mentioned above, Sa on the surface of the adhesive layer depends on the design of the adhesive layer, so it can not be said in general, but Sa on the polyester surface from which the adhesive layer has been removed (polyester surface without forming the adhesive layer) is usually 50 nm The thickness is preferably 30 nm or less, more preferably 20 nm or less, still more preferably 15 nm or less, and particularly preferably 10 nm or less. By using in the said range, it becomes easier to adjust Sa of the adhesive layer surface.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples as long as the gist thereof is not 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 the amount of ester cyclic trimer (ethylene terephthalate cyclic trimer) contained in the polyester raw material 200 mg of the polyester raw material was weighed, and the ratio of chloroform / HFIP (hexafluoro-2-isopropanol) was 3: 2. Dissolve in 2 ml of mixed solvent. After dissolution, 20 ml of chloroform is added, and then 10 ml of methanol is added little by little. The precipitate is removed by filtration, and the precipitate is washed with a mixed solvent of chloroform / methanol ratio 2: 1. The filtrate / washing solution is collected, concentrated by an evaporator, and then dried. After the dried product was dissolved in 25 ml of DMF (dimethylformamide), this solution was subjected to liquid chromatography (manufactured by Shimadzu Corporation: LC-7A, mobile phase A: acetonitrile, mobile phase B: 2% aqueous acetic acid, column: Mitsubishi Chemical Corporation). MCI GEL ODS 1HU manufactured by the company, column temperature: 40 ° C., flow rate: 1 ml / min, detection wavelength: 254 nm), the amount of ester cyclic trimer in DMF was determined, and this value was used as a chloroform / HFIP mixed solvent. It is divided by the dissolved polyester raw material amount to obtain the contained ester cyclic trimer amount (% by weight). The amount of ester cyclic trimer in DMF was determined from the peak area ratio of the standard sample peak area to the measurement sample peak area (absolute calibration method). The standard sample was prepared by accurately weighing the ester cyclic trimer obtained in advance and dissolving it in the correctly weighed DMF.

(3) Measuring method of average particle size (d50: μm) 50% integrated (weight basis) value in equivalent spherical distribution measured using centrifugal sedimentation type particle size distribution measuring device SA-CP3 type manufactured by Shimadzu Corporation Was the average particle size.

(4) Method for Measuring Arithmetic Average Roughness (Sa) Using a non-contact surface / layer cross-sectional shape measurement system VertScan (registered trademark) R550GML, manufactured by Ryoka System Co., Ltd., a CCD camera: SONY HR- 50 1/3 ′, objective lens: 20 ×, lens barrel: 1 × Body, zoom lens: No Relay, wavelength filter: 530 white, measurement mode: Wave, and output by fourth-order polynomial correction was used.

(5) Method of Measuring Film Thickness of Adhesive Layer (and Functional Layer) The surface of the adhesive layer or the functional layer was stained with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, and the adhesive layer cross-section was measured using a TEM (Hitachi High Technologies Corporation H-7650, accelerating voltage 100 kV).
In addition, the adhesive layer and the functional layer were hard to distinguish the boundary of the layer, and the thing which integrated the adhesive layer and the functional layer was evaluated as the film thickness of the adhesive layer.

(6) Glass transition point Using a differential scanning calorimeter (DSC) 8500, manufactured by PerkinElmer Japan Co., Ltd., the temperature was measured at −100 to 200 ° C. under a temperature rising condition of 10 ° C. per minute.

(7) Adhesive strength evaluation method (adhesive strength)
The pressure-sensitive adhesive layer surface of the laminated polyester film of the present invention having a width of 5 cm is applied to the surface of a polymethylmethacrylate plate (Kuraray Co., Ltd. (commercial glass (registered trademark), 1 mm thick)) with a 2 cm rubber roller having a width of 5 cm, The peel force after standing for 1 hour was measured. For the peeling force, “Ezgraph” manufactured by Shimadzu Corporation was used, and 180 ° peeling was performed under the condition of a tensile speed of 300 mm / min.

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

(9) Method of measuring haze change amount of film by heat treatment On the surface of the polyester film opposite to the surface to be measured (surface on the adhesive layer side), 80 parts by weight of dipentaerythritol hexaacrylate, 2-hydroxy-3- A mixed coating solution of 20 parts by weight of phenoxypropyl acrylate, 5 parts by weight of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) and 200 parts by weight of methyl ethyl ketone was applied so that the dry film thickness was 3 μm. A hard coat layer was formed by curing by irradiating with ultraviolet rays. The haze of the film on which the hard coat layer was formed was measured by the method of (8). Next, the measurement surface, which is the surface opposite to the hard coat layer of the film, is overlaid and fixed with Kent paper, and left to stand at 150 ° C. for 90 minutes in a nitrogen atmosphere for heat treatment, and the method of (8) The haze was measured. The difference between the haze after heat treatment and the haze before heat treatment was calculated and used as the amount of haze change.

(10) Evaluation method of adhesion of substrate of adhesive layer Adhesive layer side of one A4 size laminated polyester film and A4 size film without the adhesive layer of Comparative Example 1 to be described later are stacked and pressed firmly with fingers. After pasting, the film having the adhesive layer is peeled off, and the film surface without the adhesive layer of Comparative Example 1 is observed, and when there is no adhesive residue (the transfer trace of the adhesive layer) (the adhesive layer and the original base material) The case where the adhesiveness of (A) is good, and the case where there is adhesive residue (the case where the substrate adhesion of the adhesive layer is poor) is B.

(11) Evaluation method of transferability of adhesion layer to adherend Adhesion of laminated polyester film of the present invention having a width of 5 cm on the surface of a polymethylmethacrylate plate (Komoray Co., Ltd. (registered trademark), thickness 1 mm) The layer surface was subjected to two reciprocating pressure bonding with a 2 cm rubber roller having a width of 5 cm, followed by attachment, treatment at 60 ° C. for 8 days, the film was peeled off, and the surface of the polymethyl methacrylate plate was observed.

  A: when there is no mark on the polymethyl methacrylate plate (no transition of the adhesive layer is seen); B, when a very slight thin mark is observed when staring under fluorescent light for 3 seconds; When C is observed, a clear white mark is partially observed such as the end where the film is stuck (the adhesive layer is transferred) D, when a clear white mark is observed over the entire surface E. In addition, "-" was described when not sticking to a to-be-adhered body. In applications where transferability is a concern, it is better to avoid D and E, and in applications where low transferability is required, it is preferable that the level is A or B, particularly A.

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 a content of 0.63 and a diethylene glycol content of 2 mol% and an ester cyclic trimer content of 1.0% by weight was obtained.

<Method for producing polyester (B)>
Polyester (A) is pre-crystallized at 160 ° C. in advance, and then solid-phase polymerized in a nitrogen atmosphere at 210 ° C., limiting viscosity 0.72, diethylene glycol content 2 mol%, ester cyclic trimer content A polyester (B) having an amount of 0.50% by weight was obtained.

<Method for producing polyester (C)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, magnesium acetate tetrahydrate as a catalyst 900 ppm with respect to the formed polyester was subjected to esterification reaction at 225 ° C. in a nitrogen atmosphere. 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. Melt polycondensation was performed for 85 minutes to obtain a polyester (C) having an intrinsic viscosity of 0.64, an amount of diethylene glycol of 2% by mole, and a content of an ester cyclic trimer of 0.98% by weight.

<Method for producing polyester (D)>
In the process for producing polyester (A), polyester (E) is obtained using the same method as the process for producing polyester (A) except that 0.3 parts by weight of silica particles having an average particle diameter of 2 μm is added before melt polymerization. The

<Method for producing polyester (E)>
Polyester (E) is produced using the same method as in the production of polyester (A) except that in the production method of polyester (A), 0.6 parts by weight of silica particles having an average particle diameter of 3.2 μm is added before melt polymerization. I got

The example of a compound which comprises an adhesion layer and a functional layer is as follows.
(Example of compound)
・ Polyester resin: (IA)
Water dispersion of polyester resin (glass transition point: −20 ° C.) having the following composition: Monomer composition: (acid component) dodecanedicarboxylic acid / terephthalic acid / isophthalic acid / 5-sodiumsulfoisophthalic acid // (diol component) ethylene Glycol / 1,4-butanediol = 20/38/38/4 // 40/60 (mol%)
・ Polyester resin: (IB)
Water dispersion of polyester resin (glass transition point: −30 ° C.) having the following composition: Monomer composition: (acid component) dodecanedicarboxylic acid / terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene Glycol / 1,4-butanediol = 30/33/33/4 // 40/60 (mol%)

・ Acrylic resin: (IC)
Aqueous dispersion of acrylic resin (glass transition temperature: -50 ° C) having the following composition: 2-ethylhexyl acrylate / methyl methacrylate / methacrylic acid = 85/12/3 (% by weight)
・ Acrylic resin: (ID)
Aqueous dispersion of acrylic resin (glass transition point: −55 ° C.) having the following composition: 2-ethylhexyl acrylate / normal butyl acrylate / methyl methacrylate / 2-hydroxyethyl methacrylate = 77/10/5/8 (% by weight)
・ Acrylic resin: (IE)
Aqueous dispersion of acrylic resin (glass transition point: −25 ° C.) having the following composition Normal butyl acrylate / styrene / acrylic acid = 62/35/3 (% by weight)
・ Acrylic resin: (IF)
Aqueous dispersion of acrylic resin (glass transition point: −40 ° C.) having the following composition: 2-ethylhexyl acrylate / normal butyl acrylate / methyl methacrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58/20/15/5 / 2 (weight%)

・ Acrylic resin: (IG)
Aqueous dispersion of acrylic resin (glass transition point: −40 ° C.) having the following composition: normal butyl acrylate / 2-ethylhexyl acrylate / acrylonitrile / acrylic acid = 82/10/5/3 (% by weight)
・ Acrylic resin: (IH)
Aqueous dispersion of acrylic resin (glass transition point: −50 ° C.) having the following composition: 2-ethylhexyl acrylate / normal butyl acrylate / ethyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 50/27/15/5 / 3 (weight%)

Melamine compound: (IIA) hexamethoxymethylolmelamine oxazoline compound: (IIB)
Oxazoline group-containing acrylic polymer EPOCROS (registered trademark) (The amount of oxazoline group = 7.7 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)
・ Epoxy compounds: (IIC)
Polyglycerol polyglycidyl ether which is a polyfunctional polyepoxy compound

・ Isocyanate compounds: (IID)
1000 parts of hexamethylene diisocyanate were stirred at 60 ° C., and 0.1 part of tetramethylammonium caprylate was added as a catalyst. After 4 hours, 0.2 part of phosphoric acid was added to stop the reaction to obtain an isocyanurate type polyisocyanate composition. 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 temperature of the reaction solution was maintained at 60 ° C., 35.8 parts of methyl isobutanoyl acetate, 32.2 parts of diethyl malonate, and 0.88 parts of a 28% methanol solution of sodium methoxide were added, and held for 4 hours. 58.9 parts of n-butanol is added, and the reaction solution temperature is maintained at 80 ° C. for 2 hours, and then blocked polyisocyanate by active methylene obtained by adding 0.86 parts of 2-ethylhexyl acid phosphate

・ Polyester resin: (IIIA)
Water dispersion of polyester resin (glass transition point: 30 ° C.) 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 = 40/56/4 // 45/25/30 (mol%)
・ Polyester resin: (IIIB)
Water dispersion of polyester resin (glass transition point: 50 ° C.) 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 = 50/46/4 // 70/20/10 (mol%)

・ Acrylic resin: (IIIC)
Aqueous dispersion of acrylic resin (glass transition point: 10 ° C.) having the following composition: normal butyl acrylate / ethyl acrylate / methyl methacrylate / 2-hydroxyethyl methacrylate / acrylic acid = 10/52/30/5/3 (% by weight)
・ Acrylic resin: (IIID)
Aqueous dispersion of acrylic resin (glass transition temperature: 40 ° C.) consisting of the following composition: ethyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 48/45/4/3 (% by weight)

・ Polyvinyl alcohol: (IIIE)
Polyvinyl alcohol having a saponification degree of 88 mol% and a polymerization degree of 500

-Compounds having an ammonium group: (IV)
Water dispersion 2- (trimethylammonio) ethyl methacrylate / butyl methacrylate / ethyl methacrylate = 75/15/10 (% by weight) having the following composition, counter ion is monomethyl sulfate ion, and number average molecular weight is 150,000 .

-Particles: (V) Silica particles with an average particle size of 45 nm

Example 1:
A mixed material in which polyesters (A), (C) and (D) are mixed at a ratio of 91%, 3% and 6%, respectively, is used as a material of the outermost layer (surface layer), and polyesters (A) and (C) are 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 with a layer structure of layers (surface layer / intermediate layer / surface layer = 3: 19: 3 discharge amount) and cooled and solidified to obtain an unstretched film. Thereafter, a water-based coating solution P1 shown in Table 1 below is applied to one side of the unstretched film, dried, and the film thickness (coating amount) as the final film after drying and stretching is 0.05 g / m ² A film having a layer was obtained. Next, after stretching 3.3 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, the water-based coating solution A1 shown in Table 2 below is applied to the functional layer side of this longitudinally stretched film The film thickness (total of functional layer and adhesive layer after drying) was applied to 200 nm (estimated to be 150 nm for the adhesive layer alone), guided to a tenter, dried at 90 ° C. for 10 seconds, and then laterally The film was stretched 4.3 times at 110 ° C. and heat-treated at 230 ° C. for 10 seconds, and then relaxed by 2% in the transverse direction to obtain a polyester film having a thickness of 25 μm and an Sa of the adhesive layer surface of 9 nm. When the adhesive layer and the functional layer were removed with ethyl acetate, Sa of the polyester surface on the side where the adhesive layer was present was 9 nm.

  The obtained polyester film was evaluated. The adhesion to a polymethyl methacrylate plate was 20 mN / cm, the adhesion characteristic was good, the change in haze was as low as 0.0%, and the ester cyclic trimer precipitated Was not seen and was good. The properties of this film are shown in Table 3 below.

Examples 2 to 66:
In Example 1, except having changed a coating agent composition into the coating agent composition shown to Table 1 and 2, it manufactured like Example 1 and the polyester film was obtained. As shown in Tables 3 and 4 below, the obtained polyester film had a good adhesion and a change in haze.

Example 67:
A mixed material in which polyesters (B), (C) and (D) are mixed at a ratio of 91%, 3% and 6%, respectively, is used as a material of the outermost layer (surface layer), and polyesters (A) and (C) are 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. The film was coextruded and cooled and solidified with a layer structure of layers (surface layer / intermediate layer / surface layer = 5: 15: 5 discharge amount) to obtain an unstretched film. Thereafter, a water-based coating solution P1 shown in Table 1 below is applied to one side of the unstretched film, dried, and the film thickness (coating amount) as the final film after drying and stretching is 0.05 g / m ² A film having a layer was obtained. Next, after stretching 3.3 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, the water-based coating solution A1 shown in Table 2 below is applied to the functional layer side of this longitudinally stretched film The film thickness (total of functional layer and adhesive layer after drying) was applied to 200 nm (estimated to be 150 nm for the adhesive layer alone), guided to a tenter, dried at 90 ° C. for 10 seconds, and then laterally The film was stretched 4.3 times at 110 ° C. and heat-treated at 230 ° C. for 10 seconds, and then relaxed by 2% in the transverse direction to obtain a polyester film having a thickness of 25 μm and an Sa of the adhesive layer surface of 9 nm. When the adhesive layer and the functional layer were removed with ethyl acetate, Sa of the polyester surface on the side where the adhesive layer was present was 9 nm.

  The obtained polyester film was evaluated. The adhesion to a polymethyl methacrylate plate was 20 mN / cm, the adhesion characteristic was good, the change in haze was as low as 0.0%, and the ester cyclic trimer precipitated Was not seen and was good. The properties of this film are shown in Table 5 below.

Examples 68-106:
A polyester film was obtained in the same manner as in Example 67 except that the coating composition was changed to the coating composition shown in Tables 1 and 2 in Example 67. As shown in Table 5 below, the obtained polyester film had good tack and haze change.

Example 107:
A mixed material in which polyesters (A), (C) and (E) are mixed at a ratio of 87%, 3% and 10%, respectively, is used as a material of the outermost layer (surface layer), and polyesters (A) and (C) are 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. The film was coextruded and cooled and solidified with a layer structure of layers (surface layer / intermediate layer / surface layer = 6: 13: 6 discharge amount) to obtain an unstretched film. Thereafter, a water-based coating solution P1 shown in Table 1 below is applied to one side of the unstretched film, dried, and the film thickness (coating amount) as the final film after drying and stretching is 0.05 g / m ² A film having a layer was obtained. Next, the film was stretched 3.3 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the aqueous coating liquid A1 shown in Table 2 below was applied to the functional layer side of the longitudinally stretched film. The film thickness (total of functional layer and adhesive layer after drying) was applied to 200 nm (estimated to be 150 nm for the adhesive layer alone), guided to a tenter, dried at 90 ° C. for 10 seconds, and then laterally The film was stretched 4.3 times at 110 ° C. and subjected to heat treatment at 230 ° C. for 10 seconds, and then relaxed by 2% in the lateral direction to obtain a polyester film having a thickness of 25 μm and an Sa of the adhesive layer surface of 15 nm. In addition, Sa of the polyester surface at the side with the adhesion layer at the time of removing an adhesion layer and a functional layer with ethyl acetate was 15 nm.

  The obtained polyester film was evaluated. The adhesion to a polymethyl methacrylate plate was 20 mN / cm, the adhesion characteristic was good, the change in haze was as low as 0.0%, and the ester cyclic trimer precipitated Was not seen and was good. The properties of this film are shown in Table 6 below.

Examples 108-126:
A polyester film was obtained in the same manner as in Example 107 except that the coating agent composition was changed to the coating agent composition shown in Table 1 in Example 107. As shown in Table 6 below, the obtained polyester film had good adhesion and haze change.

Example 127:
A polyester film was obtained in the same manner as in Example 1 except that the adhesive layer was not provided in Example 1. On the polyester film without the adhesive layer, the coating solution A6 shown in Table 2 below is applied so that the film thickness (after drying) of the adhesive layer is 100 nm, dried at 100 ° C. for 60 seconds, and subjected to offline coating. A polyester film having an adhesive layer laminated thereon was obtained. As shown in Table 6, the obtained polyester film had good tack and haze change. However, the adhesion of the adhesive layer to the substrate and the migration to the adherend were not good.

Example 128:
In Example 127, except having changed the composition of the adhesion layer into the composition shown in Table 2, it manufactured like Example 127 and obtained the polyester film. As shown in Table 6 below, the obtained polyester film had good adhesion and a change in haze but poor adhesion to the substrate and transferability to the adherend of the adhesive layer.

Comparative Example 1:
A polyester film was obtained in the same manner as in Example 1 except that the adhesive layer and the functional layer were not provided in Example 1. When the obtained polyester film was evaluated, as shown in the following Table 7, there was no adhesive force and the haze change was bad.

Comparative Examples 2-14:
In Example 1, except having changed a coating agent composition into the coating agent composition shown to Table 1 and 2, it manufactured like Example 1 and the polyester film was obtained. As shown in Table 7, the obtained polyester film was a film having no adhesive force or a film having a bad amount of change in haze.

Comparative Example 15:
Coating solution A6 shown in the following Table 2 on the polyester film having no adhesive layer and no functional layer obtained in Comparative Example 1 so that the film thickness (after drying) of the adhesive layer is 20 μm, at 100 ° C. for 3 minutes Was dried to obtain a polyester film having an adhesive layer formed by off-line coating. When the pressure-sensitive adhesive layer side was bonded to the polyester film of Comparative Example 1 and cut, the components of the pressure-sensitive adhesive layer that were not seen in the examples were found to be contaminated by the pressure-sensitive adhesive component. Also, the adhesive strength could not be measured well. The other characteristics were as shown in Table 7.

  The film of the present invention has few fish eyes in applications such as surface protection films used for preventing scratches and preventing dirt adhesion during transportation, storage and processing of resin plates, metal plates, etc. It is excellent in mechanical strength and heat resistance, has little precipitation of ester cyclic trimer even after heat treatment, and can be suitably used for applications that require good adhesive properties.

Claims (11)

At least one surface of the polyester film has a functional layer containing a compound derived from a crosslinking agent, and has an adhesive layer containing a resin having a glass transition point of 0 ° C. or less on the functional layer, and the film thickness of the adhesive layer Is in the range of 1 nm to 1 μm. On at least one surface of a polyester film having a functional layer containing a compound derived from a crosslinking agent, have a pressure-sensitive adhesive layer having a glass transition point in the functional layer contains 0 ℃ following resins and particles, of the adhesive layer thickness is at 10μm or less, the laminated polyester film content of the particles, characterized in range der Rukoto of 0.1 to 50 wt% as a ratio in the adhesive layer. The laminated polyester film according to claim 1, wherein the resin having a glass transition point of 0 ° C. or less is a polyester resin or a urethane resin. The glass transition point is 0 ℃ or less of the resin is an acrylic resin, as a percentage of the adhesive layer, laminated polyester film according to claim 1 or 2 said acrylic resin is in the range of 70 to 90 wt%. A pressure-sensitive adhesive layer having a functional layer containing a compound derived from a crosslinking agent on at least one surface of the polyester film, and a resin having a glass transition temperature of 0 ° C. or less on the functional layer, and a film thickness of the pressure-sensitive adhesive layer Is 10 μm or less, and the functional layer and the adhesive layer are both drawn together. The laminated polyester film according to any one of claims 1 to 5, wherein the adhesive layer is a layer formed from a coating solution containing a crosslinking agent. The laminated polyester film according to claim 3, wherein the urethane resin contains at least one selected from polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols and acrylic polyols as a component. The laminated polyester film according to claim 3, wherein the polyester resin contains an aliphatic polyvalent carboxylic acid or an aliphatic polyvalent hydroxy compound as a constituent component. The laminated polyester film according to claim 3 or 8, wherein the polyester resin contains at least one selected from a sulfonic acid, a sulfonate, a carboxylic acid, and a carboxylate as a functional group. The laminated polyester film according to claim 2, wherein an average particle diameter of the particles is 3 times or less of a film thickness of the adhesive layer. After providing a functional layer containing a compound derived from a crosslinking agent on at least one surface of the polyester film, and then providing a coating layer containing a resin having a glass transition point of 0 ° C. or less on the functional layer, together with the functional layer A method for producing a laminated polyester film, wherein an adhesive layer having a thickness of 10 μm or less is formed by stretching the coating layer in at least one direction.