JP6296088B2 - Laminated polyester film - Google Patents

Description

  The present invention relates to a laminated polyester film. For example, there are few fish eyes as a surface protection film for preventing scratches and preventing adhesion of dirt during transport, storage and 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 a small amount of oligomer precipitation 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 protective films have an appropriate adhesive force to the adherend during transport, 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 increased to improve the processing speed and various characteristics, the polyolefin-based film is not excellent in shrinkage stability due to heat, so that 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.

JP-A-5-98219 JP 2007-270005 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is that it is used for various surface protection films and the like, has few fish eyes, is excellent in mechanical strength and heat resistance, and the amount of oligomer deposited after heat treatment The object of the present invention is to provide a laminated polyester film having a small amount and good adhesive properties.

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

That is, the gist of the present invention is to have a pressure-sensitive adhesive layer containing a resin having a glass transition point of 0 ° C. or less and having a film thickness in the range of 1 nm to 5 μm on one surface of the polyester film, which is opposite to the pressure-sensitive adhesive layer. consists in the laminated polyester film, wherein the deposition amount of the ester cyclic trimer of the side of the film sheet surface to the surface when heat treated for 30 minutes at 180 ° C. is 5.0 mg / m ² or less.

  According to the laminated polyester film of the present invention, as various surface protective films, to provide a film having less fish eyes, excellent mechanical strength and heat resistance, less oligomer precipitation after heat treatment, and having good adhesive properties. And its industrial value is high.

  We think that it is necessary to change the base material of the base film significantly in order to reduce fish eyes, improve mechanical strength, and improve heat resistance, and as a result of various studies, they differ greatly from conventional polyolefin-based materials. It has been found that this can be achieved by using a polyester-based material. 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. Therefore, improvement was achieved by providing an adhesive layer on the substrate film, and the present invention was achieved.

  However, the polyester film has a property that oligomers contained in the film (low molecular weight component of polyester, particularly ester cyclic trimer) are precipitated and crystallized on the film surface by heat. For this reason, when the amount of heat is large, visibility may be reduced due to whitening of the film appearance, post-processing defects, in-process or contamination of members, and the like may occur. For this reason, it was also found out during the study that a device for suppressing the precipitation amount of the ester cyclic trimer was necessary, and improvements were made.

  The polyester used may be a homopolyester or a copolyester. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Typical polyester includes polyethylene terephthalate and the like. On the other hand, the dicarboxylic acid component of the copolyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 1 type or 2 types or more are mentioned, As a glycol component, 1 type or 2 types or more, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned.

  From the viewpoint of forming a film that can withstand various processing conditions, it is preferable that mechanical strength and heat resistance (dimensional stability by heating) are high, and for that purpose, it is sometimes preferable that the amount of the copolyester component is small. Specifically, the proportion of the monomer forming the copolyester in the polyester film is preferably in the range of 10 mol% or less, more preferably 5 mol% or less, and more preferably produced as a by-product during homopolyester polymerization. It is a grade which contains the diether component of 3 mol% or less which is a grade which will carry out. In view of mechanical strength and heat resistance, a more preferable form of polyester is 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. Since transparency of this becomes high, it is preferable. Furthermore, since a germanium compound is expensive, it is more preferable to use a titanium compound.

  Moreover, regarding the precipitation amount of an ester cyclic trimer, a titanium compound, a germanium compound, and an aluminum compound are preferably suppressed, and a titanium compound is particularly preferable. If the content of the antimony compound is not increased, the polymerization reaction tends to be disadvantageous from the viewpoint of the catalytic activity, and the amount of the ester cyclic trimer precipitated by heating the film tends to increase.

  Therefore, when an antimony compound is used as a catalyst, the amount of the catalyst is preferably small from the viewpoint of the amount of ester cyclic trimer precipitated by heating the film, and the amount is preferably 250 ppm or less, more preferably Is in the range of 200 ppm or less, more preferably 150 ppm or less. The lower limit is preferably 10 ppm from the viewpoint of the polymerization reaction. By using in the said range, the precipitation amount of the ester cyclic trimer by the heating of a film is suppressed.

  In the case of polyester using a titanium compound, the titanium element content is preferably 50 ppm or less, more preferably 1 to 20 ppm, and still more preferably 2 to 10 ppm. If the content of the titanium compound is too high, the polyester may be deteriorated in the process of melt-extruding the polyester, resulting in a strong yellowish film. If the content is too low, the polymerization efficiency is poor and the cost is low. In some cases, a film having a sufficient strength or a sufficient strength cannot be obtained. Moreover, when using the polyester by a titanium compound, it is preferable to use a phosphorus compound in order to reduce the activity of a titanium compound for the purpose of suppressing deterioration in the step of melt extrusion. As the phosphorus compound, orthophosphoric acid is preferable in view of the productivity and thermal stability of the polyester. The phosphorus element content is preferably in the range of 1 to 300 ppm, more preferably 3 to 200 ppm, and still more preferably 5 to 100 ppm with respect to the amount of polyester to be melt-extruded. If the content of the phosphorus compound is too large, it may cause gelation or foreign matter. If the content is too small, the activity of the titanium compound cannot be lowered sufficiently, and the yellowish It may be a film.

  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. It is preferable.

  In order to suppress the precipitation amount of the ester cyclic trimer after heat treatment or after aging, it is preferable to have a polyester layer with a small amount of ester cyclic trimer. Therefore, it is preferable to produce a film from a polyester having a low ester cyclic trimer content. 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.

  The polyester film is composed of three or more layers, and the outermost polyester layer of the polyester film is designed with a layer using a polyester raw material with a low ester cyclic trimer content. A method of suppressing the precipitation amount of the monomer is preferable.

  The content of the ester cyclic trimer contained in the polyester film is about 1% by weight in a general production method, but from the viewpoint of preventing precipitation of the ester cyclic trimer, the content of the ester cyclic trimer However, it preferably has a polyester layer of 0.7% by weight or less, and more preferably has a polyester layer of 0.6% by weight or less. In the case of having a polyester layer formed from a polyester having an ester cyclic trimer content of 0.7% by weight or less, the effect of preventing the precipitation of the ester cyclic trimer on the film surface is particularly high.

  The polyester used for forming the polyester layer having a small amount of the ester cyclic trimer is preferably a polyester raw material having a low content of the ester cyclic trimer, and the content of the ester cyclic trimer is 0.7% by weight. % Or less, more preferably 0.6% by weight or less, and still more preferably 0.5% by weight 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 a small amount of the ester cyclic trimer is preferably composed of a polyester layer formed from a polyester having a content of the ester cyclic trimer of 0.7% by weight or less and 70% by weight or more, More preferably, it is formed from a polyester layer formed from 80% by weight or more of polyester. 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 preferable that at least one layer of the polyester film, particularly the outermost layer of the polyester film, has a polyester layer having an ester cyclic trimer content of 0.7% by weight or less. This is preferable from the viewpoint of preventing precipitation of a monomer. Further, from the viewpoint of preventing precipitation of the ester cyclic trimer to a higher degree, it is more preferable that the content of the ester cyclic trimer is 0.7% by weight or less in all the polyester layers. .

  In addition, the polyester film with less ester cyclic trimer content (e.g., 0.7 wt% or less) has a thicker polyester layer, which effectively precipitates the ester cyclic trimer from the polyester film. It can be suppressed. The film thickness of the polyester layer having a small ester cyclic trimer content (for example, 0.7% by weight or less) is preferably thicker, preferably 2 μm or more, more preferably 3 μm or more, particularly preferably 4 μm or more. It is. The amount of precipitation of the ester cyclic trimer is most suppressed by reducing the content of the ester cyclic trimer in all layers (for example, 0.7% by weight or less). When the polyester cyclic trimer content is low (eg 0.7% by weight or less) and the film thickness of the polyester layer is 2 μm or more, prevention of precipitation of the ester cyclic trimer on the film surface after heat treatment or after aging The effect 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. When the particles are blended, the kind of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples thereof include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid. Examples thereof include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used. Of these, silica particles and calcium carbonate particles are preferable because they are particularly effective in a small amount.

  The average particle diameter of the particles is preferably 10 μm or less, more preferably 0.01 to 5 μm, and still more preferably 0.01 to 3 μm. When the average particle size exceeds 10 μm, there may be a concern about a problem due to a decrease in transparency of the film.

  Further, the content of the particles in the polyester layer is unclear because there is a balance with the average particle size of the particles, but is preferably 5% by weight or less, more preferably in the range of 0.0003 to 3% by weight, and still more preferably. Is in the range of 0.0005 to 1% by weight. When the particle content exceeds 5% by weight, there may be a concern about problems such as dropout of particles and a decrease in transparency of the film. When there are no particles or when there are few particles, the slipperiness may be insufficient. Therefore, a device such as improving the slipperiness may be required by putting 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 required.

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

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

  The thickness of the polyester film is not particularly limited as long as it can be formed into a film, but is preferably 2 to 350 μm, more preferably 5 to 200 μm, and still 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. In general, the resin is melted, formed into a sheet, and stretched for the purpose of increasing the strength and the film is formed. 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 with a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed. Next, the obtained unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is preferably 70 to 120 ° C, more preferably 80 to 110 ° C, and the stretching ratio is preferably 2.5 to 7 times, more preferably 3.0 to 6 times. Next, the film is stretched in the direction orthogonal to the first-stage stretching direction, preferably at 70 to 170 ° C., and the stretching ratio is preferably 2.5 to 7 times, more preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing heat treatment at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% can be mentioned. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

  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 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, formation of the adhesion layer which comprises a laminated polyester film is demonstrated. Examples of the method for forming 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.

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

  Specifically, the in-line coating is a method in which coating is performed at an arbitrary stage from melt extrusion of a resin forming a film to heat setting after stretching and winding. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, and a film after heat setting and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of stretching in the transverse direction after coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) is particularly excellent. According to such a method, since film formation and adhesion layer formation can be performed simultaneously, there is a merit in manufacturing cost, and in order to perform stretching after coating, the thickness of the adhesion layer can be changed by the stretching ratio. Compared to offline coating, thin film coating can be performed more easily.

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

  Therefore, since the heat treatment performed after coating can be performed at a high temperature that cannot be achieved by other methods, the film forming property of the adhesive layer can be improved, and the adhesive layer and the base film can be more firmly adhered to each other. In addition, a strong adhesive layer can be obtained. 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 significant advantage over an extra off-line 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. It was. This can be heat-treated at a high temperature that cannot be obtained by off-line coating, and is considered to be a result of the adhesive layer and the base film being more firmly adhered to each other.

In the present invention, the polyester film has an adhesive layer containing a resin having a glass transition point of 0 ° C. or less and a film thickness of 10 μm or less, and the other surface is heat-treated at 180 ° C. for 30 minutes. It is an essential requirement that the amount of ester cyclic trimer deposited on the surface is 5.0 mg / m ² or less.

  A general adhesive layer has a thick film thickness exceeding 10 μm. However, in the present invention, when the film thickness of the adhesive layer is set to a thin range of 10 μm or less, for example, when used for producing a polarizing plate, the present invention When the film is bonded to an adherend such as a polarizing plate and cut, the sticking of the adhesive in the adhesive layer can be minimized, and the absolute amount of the adhesive layer present on the film can be reduced. The amount of the adhesive layer transferred to the adherend was found to be small, and it was also found to be effective in reducing adhesive residue.

  Conventionally known resins can be used as the resin having a glass transition point of 0 ° C. or lower. 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. An acrylic resin and a urethane resin are preferable, a polyester resin and an acrylic resin are more preferable from the viewpoint of strength of adhesive properties, and a polyester resin is more preferable because adhesive strength to various adherends is high. When considering the reusability of the film, a polyester resin or an acrylic resin is preferable. When the base material is a polyester film, when considering the adhesion to the base material, the polyester resin is less susceptible to change with time. In consideration, acrylic resin is most preferable. Furthermore, when the transferability of the components of the adhesive layer to the adherend is taken into consideration, the inventors have also found that acrylic resins are preferable because they have less transferability than polyester resins.

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

  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. In general, since a polyester resin is composed of an aromatic polyvalent carboxylic acid and a polyvalent hydroxy compound including an aliphatic group, in order to lower the glass transition point than a general polyester resin, an aliphatic polyvalent compound is used. It is effective to contain a carboxylic acid. From the viewpoint of lowering the glass transition point, the aliphatic polyvalent carboxylic acid should have a long carbon number, preferably 6 or more (adipic acid), more preferably 8 or more, and still more preferably 10 or more. The upper limit of the preferred range is 20.

  Further, from the viewpoint of improving adhesive properties, the content of the aliphatic polyvalent carboxylic acid in the acid component in the polyester resin is preferably 2 mol% or more, more preferably 4 mol% or more, and even more preferably 6 mol%. As mentioned above, it is 10 mol% or more especially preferably, and the upper limit of a preferable range is 50 mol%.

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

  In consideration of suitability for in-line coating, it is preferable to use an aqueous system. Therefore, it is preferable that a hydrophilic functional group, sulfonic acid, sulfonate, carboxylic acid, or carboxylate, is contained in the polyester resin. In view of good dispersibility in water, sulfonic acid and sulfonate are preferable, and sulfonate is particularly preferable. Of the sulfonates, metal sulfonates are more preferable.

  When using the above-mentioned sulfonic acid, sulfonate, carboxylic acid, carboxylate, the content in the acid component in the polyester resin is preferably 0.1 to 10 mol%, more preferably 0.2 to 8%. It is in the range of mol%. By using in the above range, water dispersibility is good.

  In addition, when considering the appearance of coating in in-line coating, adhesion to the film and blocking, and further reduction in migration to the adherend when used as a surface protection film (adhesive residue), as an acid component in the polyester resin, It preferably contains a certain amount of aromatic polyvalent carboxylic acid. As a ratio in the acid component in the polyester resin, the aromatic polycarboxylic acid is preferably in a range of 30 mol% or more, more preferably 50 mol% or more, and further preferably 60 mol% or more, and the upper limit of the preferred 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. In order to further improve the adhesive properties, 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.

  The acrylic resin is a polymer composed of a polymerizable monomer including acrylic and methacrylic monomers (hereinafter, acrylic and methacryl may be abbreviated as (meth) acryl). These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers.

Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion (sometimes a mixture of polymers) is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included. 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; Examples include various vinyl halides such as vinyl and biliden chloride; and 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.) ), Tridecyl methacrylate (glass transition point: −46 ° C.), isomistyryl acrylate (glass transition point: −56 ° C.), 2-hydroxyethyl acrylate (glass transition point: −15 ° C.), and the like.

  Among the above, in order to improve the adhesive properties, the alkyl group preferably has a carbon number of 4 or more, more preferably 4 to 30, more preferably 4 to 20, particularly preferably 4 to 14. The range is alkyl (meth) acrylate. Industrially mass-produced, and (meth) acrylic resins containing normal butyl acrylate and 2-ethylhexyl acrylate are optimal from the viewpoints of handleability and supply stability.

  The content in the (meth) acrylic resin of the (meth) acrylate unit having an alkyl group having 4 or more carbon atoms at the ester end is preferably 20% by weight or more, more preferably 35 to 99% by weight, and still more preferably 50%. It is in the range of -98% by weight, particularly preferably 65-95% by weight, most preferably 75-90% by weight. The greater the content of the (meth) acrylate unit having an alkyl group having 4 or more carbon atoms at the ester end, the stronger the adhesive property. 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 glass transition point of the homopolymer of 0 ° C. or less and having an alkyl group having less than 4 carbon atoms at the ester terminal is preferably 50% by weight. Hereinafter, it is more preferably in the range of 40% by weight or less, and further preferably in the range of 30% by weight or less. By using in the above range, good adhesive properties are obtained.

In addition, from the viewpoint that the migration of the adhesive component to the adherend can be reduced, among the above, a compound having 2 or less carbon atoms contained in the ester terminal or a compound having a cyclic structure is preferable, and more preferable. Is a compound having 1 carbon atoms or an aromatic compound.
Specific examples include methyl methacrylate, acrylonitrile, styrene, and cyclohexyl acrylate as preferable compounds.

  The content of the compound unit having 2 or less carbon atoms contained in the ester terminal in the (meth) acrylic resin is preferably 50% by weight or less, more preferably 1 to 40% by weight, and still more preferably 3 to 3%. It is in the range of 30% by weight, particularly 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.

  In the (meth) acrylic resin, the content of the compound unit having a cyclic structure is preferably 50% by weight or less, more preferably 1 to 45% by weight, and still 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 the two objectives, adhesive characteristics and migration reduction.

  From the viewpoint of adhesive properties, the content of the monomer having a glass transition point of the homopolymer of 0 ° C. or less as the monomer constituting the (meth) acrylic resin is preferably 30% by weight as a proportion of the whole (meth) acrylic resin. Above, more preferably 45% by weight or more, still more preferably 60% by weight or more, particularly preferably 70% by weight or more. The upper limit of the preferred range is 99% by weight. It is easy to obtain good adhesive properties by using in this 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 preferably −20 ° C. or lower, more preferably −30 ° C. or lower, and further preferably −40 ° C. or lower. Especially 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.

  As a more optimal form of (meth) acrylic resin for improving the adhesive properties, the total content of normal butyl acrylate and 2-ethylhexyl acrylate in (meth) acrylic resin is preferably 30% by weight or more. More preferably, it is 40% by weight or more, more preferably 50% by weight or more, particularly preferably 60% by weight or more, and most preferably 70% by weight or more. The upper limit of the preferred 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 useful when it is desired to eliminate the transfer of the adhesive component to the adherend with a small amount of the crosslinking agent. The acrylate content is preferably 90% by weight or less, more 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.

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

  As the introduction of a hydroxyl group, various types such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate Examples thereof include copolymerizing a hydroxyl group-containing monomer. 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 preferably 30% by weight or less, more preferably 1 to 20% by weight, still more preferably 2 to 15% by weight, particularly preferably 3 to 10% by weight. Range. By using it in the above range, it becomes easy to develop an aqueous system.

  The glass transition point of the (meth) acrylic resin for improving the adhesive properties is essential to be 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −20 ° C. or lower, and still more 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 | decrease of transfer of the adhesion component to a to-be-adhered body, Preferably it is -70 degreeC or more, More preferably, it is -60 degreeC or more, More preferably, it is the range of -50 degreeC 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.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Examples of the polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane. Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane and the like can be mentioned. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of polycarbonate polyols obtained from these reactions include poly (1,6-hexylene) carbonate, poly (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 preferably in the range of 4 to 30, more preferably 4 to 20, and even more preferably 6 to 12. In terms of industrial mass production and good handling and supply stability, 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol It is optimal that it is a copolymerized polycarbonate polyol containing at least two diols selected from among them.

  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 the adhesive properties, the monomer forming the polyether is an aliphatic diol, particularly a straight chain fat, preferably having 2 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, and even more preferably 4 to 12 carbon atoms. It is a polyether polyol containing a group diol.

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

  Considering the adhesive properties, among the polyols, polycarbonate polyols and polyether polyols are more preferably used, 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 Methanzi Cyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination.

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

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

  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 an ionic group is introduced into the structure of the urethane resin to form an ionomer is preferable because of excellent storage stability of the liquid and water resistance and transparency of the resulting adhesive layer.

  Examples of the ionic group to be introduced include various groups such as a carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid, and quaternary ammonium salt, and a carboxyl group is preferred. As a method for introducing a carboxyl group into a urethane resin, various methods can be taken in each stage of the polymerization reaction. For example, there are a method of using a carboxyl group-containing resin as a copolymer component during prepolymer synthesis, and a method of using a component having a carboxyl group as one component such as polyol, polyisocyanate, and chain extender. In particular, a method in which a desired amount of carboxyl groups is introduced using a carboxyl group-containing diol depending on the amount of this component charged is preferred.

For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid and the like are copolymerized with a diol used for polymerization of a urethane resin. Can do. The carboxyl group is preferably in the form of a salt neutralized with ammonia, amine, alkali metal, inorganic alkali or the like. Particularly preferred are ammonia, trimethylamine and triethylamine.
In such a urethane resin, the carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a crosslinking reaction point by another crosslinking agent. Thereby, it is possible to further improve the durability, solvent resistance, water resistance, blocking resistance and the like of the obtained adhesive layer as well as excellent stability in the liquid state before coating.

  The glass transition point of the urethane resin for improving the adhesive properties must be 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −20 ° C. or lower, and further preferably −30 ° C. 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 examples thereof include melamine compounds, isocyanate compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, and aziridine compounds. 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. These crosslinking agents may be used alone or in combination of two or more.

  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 deteriorated too much. Therefore, it is preferable to pay attention to the content in the adhesive layer.

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

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

  When used in the state of blocked isocyanate, the blocking agent includes, for example, bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcohols such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. Compounds, active methylene compounds such as 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, an isocyanate compound blocked with an active methylene compound is preferable from the viewpoint that it is particularly effective for reducing the migration of the adhesive layer to the adherend.

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

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

  Of the above, polyether epoxy compounds are preferable from the viewpoint of good adhesive properties. The amount of the epoxy group is preferably a polyepoxy compound that is trifunctional or more polyfunctional than bifunctional.

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

  The amount of the oxazoline group of the oxazoline compound is preferably in the range of 0.5 to 10 mmol / g, more preferably 1 to 9 mmol / g, still more preferably 3 to 8 mmol / g, and particularly preferably 4 to 6 mmol / g. By using in the said range, durability improves and it becomes easy to adjust an adhesive characteristic.

  The carbodiimide compound is a compound having one or more carbodiimide or carbodiimide derivative structures in the molecule. A polycarbodiimide compound having two or more molecules in the molecule is more preferable for better adhesive layer strength and the like.

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

  Furthermore, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound within a range not losing the effect of the present invention, a surfactant may be added, or a polyalkylene oxide or a quaternary ammonium salt of a dialkylamino alcohol. Hydrophilic monomers such as hydroxyalkyl sulfonates may be added and used.

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

  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 group) epoxy group-containing compounds such as ethyltrimethoxysilane, vinyl group-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane, styryl group-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) Examples include isocyanurate group-containing compounds such as cyanurate, mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. It is done.

  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.

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

  In addition, the glass transition point is 0 ° C. from the viewpoints of appearance of the adhesive layer, adjustment of adhesive strength, reinforcement of the adhesive layer, adhesion to the base film, blocking resistance, and prevention of migration of the adhesive component to the adherend. It is also possible to use a resin in excess of. A conventionally known material can be used as the resin having a glass transition point exceeding 0 ° C. Among them, polyester resin, acrylic resin, urethane resin and polyvinyl (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.) are preferable, and polyester resin, acrylic resin and urethane are considered in view of the appearance of the adhesive layer and the influence on adhesive strength. A resin selected from resins is 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 the polyester resin as a resin having a glass transition point exceeding 0 ° C., a 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. Further, the content of the aromatic polycarboxylic acid as a ratio in the acid component in the polyester resin is preferably 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, particularly preferably. It is preferably in the range of 90% by weight and not containing an aliphatic polyvalent carboxylic acid, particularly an aliphatic polyvalent carboxylic acid having 6 or more carbon atoms, from the viewpoints of adjustment of adhesive strength and blocking resistance.

  Various urethanes can be used as the urethane resin as a resin having a glass transition point exceeding 0 ° C. Among them, urethanes based on polyester polyols are particularly preferred 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 adjusting the adhesive strength. Moreover, as a ratio in a urethane resin, content of aromatic polyhydric carboxylic acid becomes like this. Preferably it is 5 to 80 weight%, More preferably, it is 15 to 65 weight%, More preferably, it is the range of 20 to 50 weight%. By using it in the said range, it becomes easy to improve adhesive force adjustment and anti-blocking performance.

  The glass transition point of the resin having a glass transition point exceeding 0 ° C. is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, and further preferably 30 ° C. or higher. 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, it is preferable that the average particle size of the particles used is 3 times or less the thickness of the adhesive layer, more preferably 1.5 times or less, and even more preferably 1.0 times or less. Particularly preferably, the range is 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 adhesive layer for various functions. As a preferred form, it is a functional layer that can suppress the precipitation amount of the ester cyclic trimer by heating. However, in the range not impairing the gist of the present invention, for example, to reduce blocking of the film by the adhesive layer. It is also preferable to provide a release layer, and it is also preferable to provide an antistatic layer in order to prevent defects due to adhesion of dust around the film due to film peeling or frictional charging.

The functional layer may be provided by coating, may be provided by in-line coating, or may employ offline coating. In-line coating is preferably used from the viewpoint of production cost and stabilization of various performances of the functional layer by in-line heat treatment.

Examples of the functional layer that can suppress the precipitation amount of the ester cyclic trimer on the film surface by heating include a method of containing a material that suppresses the precipitation amount of the ester cyclic trimer on the film surface by heating. A compound having a chemical structure different from that of the polyester resin or a crosslinkable compound is effective in terms of material, and examples thereof include a compound having an ammonium group, a crosslinking agent such as a melamine compound, polyvinyl alcohol, and various metal compounds.

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

  Among the compounds having an ammonium group, a compound having a pyrrolidinium ring is preferable in that it suppresses the precipitation amount of the ester cyclic trimer by heating and is excellent in heat stability.

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

  A polymer having a pyrrolidinium ring can be obtained by cyclopolymerizing a diallylamine derivative using a radical polymerization catalyst. The polymerization is carried out by using a polymerization initiator such as hydrogen peroxide, benzoyl peroxide, tertiary butyl peroxide in a polar solvent such as water or methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane, acetonitrile as a solvent. Although it can implement by a method, it is not limited to these. A compound having a carbon-carbon unsaturated bond polymerizable with a diallylamine derivative may be used as a copolymerization component. From the viewpoint of suppressing the precipitation amount of ester cyclic trimer by heating, rather than homopolymers of diallylamine derivatives, copolymers of compounds having various carbon-carbon unsaturated bonds (acrylic and methacrylic compounds) Is preferred.

  Moreover, it is also preferable that it is a polymer which has the structure of following formula (1) at the point which is excellent in suppression of the precipitation amount of the ester cyclic trimer by heating, and excellent in heat-and-moisture stability. A single polymer or copolymer, or a plurality of other components may be copolymerized. From the viewpoint that the precipitation amount of the ester cyclic trimer by heating can be reduced, the compound having the structure of the following formula (1) is more preferable than the compound having the pyrrolidinium ring.

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

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

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

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

  In addition, the advantage of the compound having an ammonium group is that not only the amount of ester cyclic trimer precipitated can be suppressed, but also the antistatic performance of the functional layer can be imparted, preventing adhesion of foreign matters such as dust, The film has good visibility and can be handled easily. In particular, from the viewpoint of antistatic properties, a compound having a pyrrolidinium ring or a compound having the structure of the above formula (1) is preferable, and a compound having a pyrrolidinium ring is particularly preferable.

  As the cross-linking agent, various cross-linking agents that can be contained in the above-mentioned adhesive layer can be used. From the viewpoint that the amount of ester cyclic trimer precipitated by heating can be suppressed, melamine compounds, oxazoline compounds, and epoxy compounds are used. A melamine compound is particularly preferable. Moreover, when a melamine compound is contained, it is also preferable in that the strength of the functional layer can be increased.

Polyvinyl alcohol is a compound having a polyvinyl alcohol moiety. For example, conventionally known polyvinyl alcohol can be used including modified compounds partially acetalized or butyralized with respect to polyvinyl alcohol. The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably 300 to 40,000. When the degree of polymerization is less than 100, the water resistance of the functional layer may decrease. Further, the saponification degree of polyvinyl alcohol is not particularly limited, but a polyvinyl acetate saponified product in a range of 70 mol% or more, preferably in the range of 70 to 99.9 mol% is practically used.

Various metal compounds are compounds containing metals, such as sodium chloride, sodium bromide, sodium carbonate, sodium nitrate, potassium chloride, potassium nitrate, strontium chloride, strontium nitrate, cesium chloride, cesium acetate, magnesium chloride. , Magnesium nitrate, calcium chloride, calcium nitrate, iron chloride (II), iron bromide (II), iron nitrate, potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), cobalt chloride (II), bromide Cobalt (II), cobalt iodide (II), cobalt nitrate (II), cobalt acetate (II), cobalt sulfate (II), nickel chloride (II), nickel bromide (II), nickel nitrate (II), acetic acid Nickel (II), nickel sulfate (II), palladium (II) sodium chloride, copper (II) chloride, copper bromide (II), copper nitrate II), copper sulfate (II), silver nitrate, zinc chloride, zinc nitrate, zinc acetate, aluminum chloride, aluminum nitrate, indium chloride (III), metal salt compounds such as indium nitrate (III), titanium triethanolamate, titanium Examples include titanium chelate compounds such as lactate and titanium acetylacetonate, zirconium chelate compounds such as zirconium acetylacetonate, aluminum chelate compounds such as aluminum acetylacetonate, and metal chelate compounds such as cobalt chelate compounds such as cobalt acetylacetonate. .

  For the formation of the functional layer, various conventionally known polymers such as a polyester resin, an acrylic resin, and a urethane resin can be used in combination for improving the coating appearance and transparency. In addition, particles can be used in combination for the purpose of improving blocking properties and slipping properties, as long as the gist of the present invention is not impaired. In addition to the particles, for example, a release agent such as a long-chain alkyl group-containing compound, a fluorine compound, a silicone compound, or a wax can be used in combination to improve blocking resistance and slipperiness.

  Furthermore, in the range not impairing the gist of the present invention, an antifoaming agent, a coating property improving agent, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, Antioxidants, foaming agents, dyes, pigments and the like can be used in combination.

  As a ratio in the adhesive layer constituting the laminated polyester film, the resin having a glass transition point of 0 ° C. or lower is usually 5% by weight or more, preferably 10 to 99.5% by weight, more preferably 30 to 98% by weight, More preferably, it is 45 to 96% by weight, particularly preferably 55 to 94% by weight, and most preferably 70 to 90% by weight. By using in the above range, sufficient adhesive force can be easily obtained, and the adhesive force can be easily adjusted. When the content is too small, the adhesive strength may be reduced, and thus it may be necessary to devise such as increasing the thickness of the adhesive layer. 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 pressure-sensitive adhesive layer constituting the laminated polyester film, the crosslinking agent is preferably 0.5 to 80% by weight, more preferably 1 to 65% by weight, further preferably 3 to 50% by weight, and particularly preferably 5 to 5% by weight. It is in the range of 40% by weight, most preferably 8-25% 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 transfer to the adherend will increase. Conversely, if the content is too large, the adhesive strength may decrease, so a device such as increasing the thickness of the adhesive layer is required. 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 preferably 70% by weight or less, more preferably 0.1 to 50% by weight, still more preferably 0.5 to 30% by weight, particularly preferably 1 to 1. It is in the range of 20% by weight. By using in the above range, sufficient adhesive properties, anti-blocking properties and slipperiness are easily obtained.

  As a ratio in the adhesive layer constituting the laminated polyester film, the resin having a glass transition point exceeding 0 ° C. is preferably in the range of 80% by weight or less, more preferably 50% by weight or less, and further preferably 30% by weight or less. . Use in the above range can be expected to improve the appearance of the pressure-sensitive adhesive layer, the adjustment of the adhesive strength, the reinforcement of the pressure-sensitive adhesive layer, the adhesion to the substrate film, and the blocking resistance. 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.

As a ratio in the functional layer that can constitute the laminated polyester film, the total amount of a compound having a chemical structure different from that of the polyester resin or a crosslinkable compound (for example, a compound having an ammonium group, a crosslinking agent, polyvinyl alcohol, various metal compounds) Etc.) is preferably in the range of 10% by weight or more, more preferably 30% by weight or more, further preferably 50% by weight or more, particularly preferably 70% by weight or more, most preferably 85% by weight or more. The total amount may be 100% by weight. By using in the said range, precipitation amount reduction of ester cyclic trimer is attained.

  In the case where a function for reducing the precipitation amount of the ester cyclic trimer is required for the functional layer and a compound having an ammonium group is used, the ratio of the compound having an ammonium group in the functional layer is preferably 10 to 90. % By weight, more preferably 15 to 75% by weight, and still more preferably 20 to 60% by weight. By using it in the above range, it is possible to reduce the precipitation amount of the ester cyclic trimer at a higher level.

  In the case where a function for reducing the precipitation amount of the ester cyclic trimer is required for the functional layer and when a crosslinking agent is used, the ratio of the crosslinking agent in the functional layer is preferably 10% by weight or more, more preferably 20%. It is in the range of not less than wt%, more preferably not less than 30 wt%, and the entire amount may be a crosslinking agent. By using it in the above range, it is possible to reduce the precipitation amount of the ester cyclic trimer at a higher level.

  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.

  Regarding the formation of the adhesive layer and functional layer, the above-mentioned series of compounds is used as a solution or solvent dispersion, and the film is coated with a liquid adjusted to a solid content concentration of about 0.1 to 80% by weight. It is preferable to produce a laminated polyester film. In particular, when provided by in-line coating, an aqueous solution or a water dispersion is more preferable. A small amount of an organic solvent may be contained in the coating solution for the purpose of improving the dispersibility in water, improving the film forming property, and the like. Moreover, only one type of organic solvent may be used, and two or more types may be used as appropriate.

  It is essential that the thickness of the adhesive layer is 10 μm or less, preferably 1 nm to 5 μm, more preferably 5 to 2500 nm, still more preferably 10 to 1000 nm, particularly preferably 20 to 700 nm, and most preferably 30 to 400 nm. Range. By using the film thickness of the adhesive layer within the above range, it becomes easy to maintain appropriate adhesive properties and blocking properties.

  A general adhesive layer has a thick film thickness exceeding 10 μm. In such a case, for example, when used for manufacturing a polarizing plate, the adhesive film is covered with a polarizing plate, a retardation plate, a viewing angle expansion plate, or the like. When sticking to a bonded body and cutting, the sticking out of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer may occur remarkably. However, the protrusion can be minimized by adjusting the film thickness within the above-mentioned range. 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. Furthermore, it can be seen that by setting the film thickness in the above-mentioned range, it is possible to achieve an appropriate adhesive strength that is not too strong. For example, for polarizing plate manufacturing processes, both adhesive performance and peeling performance that peels after bonding are achieved. In the case where it is used for an application where it is necessary to achieve the above, an operation of bonding and peeling can be easily performed, and an optimum film can be obtained. The thinner the film is, the more effective it is for blocking properties, and it is easier to manufacture when forming an adhesive layer by in-line coating. On the other hand, if the film thickness is too thin, the adhesive properties may vary depending on the configuration of the adhesive layer. Since it may disappear, use in the above-mentioned suitable range according to a use is preferable.

  The thickness of the functional layer is preferably in the range of 1 nm to 3 μm, more preferably 10 nm to 1 μm, still more preferably 15 to 500 nm, and particularly preferably 20 to 200 nm. By using the film thickness of the functional layer within the above range, it becomes possible to reduce the amount of ester cyclic trimer deposited by heating and to obtain a good appearance.

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

  The drying and curing conditions for forming the adhesive layer on the film are not particularly limited, but in the case of the coating method, the drying of a solvent such as water used in the coating solution is preferably 70. It is -150 degreeC, More preferably, it is 80-130 degreeC, More preferably, it is the range of 90-120 degreeC. The drying time is generally 3 to 200 seconds, preferably 5 to 120 seconds. Moreover, in order to improve the intensity | strength of an adhesion layer, in a film manufacturing process, Preferably it is 180-270 degreeC, More preferably, it is 200-250 degreeC, More preferably, it is passing through the heat processing process of the range of 210-240 degreeC. The time for the heat treatment step is generally 3 to 200 seconds, preferably 5 to 120 seconds.

  Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed. The 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 adhesive strength of the adhesive layer is preferably 1 to 5000 mN / cm, more preferably 3 to 1000 mN / cm, and still more preferably 5 as measured by the measurement method described later. ˜500 mN / cm, particularly preferably 7 to 300 mN / cm, most 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.

The amount of ester cyclic trimer extracted from the film surface with dimethylformamide by heat treatment at 180 ° C. for 30 minutes as the amount of precipitation of the ester cyclic trimer on the opposite side of the film from the adhesive layer is 5.0 mg / m ² or less is essential, preferably 3.0 mg / m ² or less, more preferably 2.0 mg / m ² or less, still more preferably 1.0 mg / m ² or less, particularly preferably 0.5 mg / m 2. It is a range of ² or less, and the ideal image is not precipitated (0.0 mg / m ² ). If it exceeds 5.0 mg / m ² , the amount of the foreign substance due to the ester cyclic trimer increases, and the visibility of the film may deteriorate, or it may lead to contamination of various processes.

  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. Moreover, when Sa is too high, in order to express adhesive force, it may be necessary to adjust the film thickness of the adhesive layer to be thick, and adjustment of adhesive force and reduction of the transfer of adhesive components to the adherend may be reduced. It can be difficult. The lower limit is not particularly limited, but the lower limit of the preferred 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 interrelationship of 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 the particles is preferably 5 μm or less. More preferably, it is a 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 preferably less than 0.30% by weight, more preferably 0.15% by weight or less, still more preferably 0.10% by weight or less, particularly preferably 0.08. It is in the range of weight percent or less. By using in the said range, it becomes easy to make Sa low.

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

As described above, Sa on the adhesive layer surface depends on the design of the adhesive layer, so it cannot be said unconditionally. However, the Sa of the polyester surface from which the adhesive layer has been removed (polyester surface when the adhesive layer is not formed) is preferably The range is 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.
By using in the said range, it will become easier to adjust Sa of the adhesion layer surface.

  As the haze of the laminated polyester film, when confirmation or inspection is performed in a state of being bonded to the adherend, the haze value is preferably low, preferably 5.0% or less, more preferably 3.0. % Or less, more preferably 2.0% or less, particularly preferably 1.5% or less, and most preferably 1.0% or less. It is preferable that the haze is lower when inspecting foreign matter or the like with a machine than with visual confirmation. The lower limit is not particularly limited, but a preferable range is 0.1%. Since visibility and straightness of light are improved by using in the above range, the state of the adherend can be grasped without removing the polyester film as the protective film even when various inspections and confirmations are required. .

  Polyolefin films, which are conventional surface protection films, have high haze (exceeding about 10%, etc.) and inferior in transparency, so it is sufficient to inspect the adherend with the surface protection film attached. It can not be done, it takes time and labor to peel off the surface protection film to inspect the adherend, and further, there is a risk of causing defects such as adhesion of foreign objects and scratches when peeled off, In some cases, a surface protective film having low haze and high transparency that can inspect the adherend in a state where the surface protective film is bonded is required.

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

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

(2) Method for measuring 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, add 20 ml of chloroform, and then add 10 ml of methanol 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. Divide by the amount of dissolved polyester raw material to obtain the amount of ester cyclic trimer (weight%). The amount of ester cyclic trimer in DMF was determined from the peak area ratio between the standard sample peak area and the measured sample peak area (absolute calibration curve method). The standard sample was prepared by accurately weighing the pre-sorted ester cyclic trimer and dissolving it in DMF accurately weighed.

(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 for Measuring Film Thickness of Adhesive Layer and Functional Layer The surface of the adhesive layer or functional layer was dyed 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).

(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) Number average molecular weight measurement method It measured using GPC (HLC-8120GPC by Tosoh Corporation). The number average molecular weight was calculated in terms of polystyrene.

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

(9-1) Adhesive strength evaluation method (adhesive strength 1)
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.

(9-2) Adhesive strength evaluation method (adhesive strength 2)
(9-1) except that the adhesive strength is evaluated using the polyester film surface (thickness 25 μm) without an adhesive layer obtained in Comparative Example 1 described later, instead of the polymethyl methacrylate plate (9-1). ) And the evaluation was performed in the same manner.

(10) Method for measuring amount of ester cyclic trimer (ethylene terephthalate cyclic trimer) deposited on the side opposite to the adhesive layer The laminated polyester film is heated in air at 180 ° C. for 30 minutes, and then subjected to heat treatment. A box-like shape was created with the measurement surface (the side opposite to the adhesive layer) as the inner surface so that the film was 10 cm long and 3 cm high with the top open. Next, 4 ml of DMF was placed in the box prepared by the above method and allowed to stand for 3 minutes, after which DMF was recovered and subjected to liquid chromatography (manufactured by Shimadzu Corporation: LC-7A, mobile phase A: acetonitrile, mobile phase B: 2% acetic acid aqueous solution, column: MCI GEL ODS 1HU manufactured by Mitsubishi Chemical Corporation, column temperature: 40 ° C., flow rate: 1 ml / min, detection wavelength: 254 nm), and the amount of ester cyclic trimer in DMF is determined. This value was divided by the film area with which DMF was contacted to obtain the film surface ester cyclic trimer amount (mg / m ² ). The amount of ester cyclic trimer in DMF was determined from the peak area ratio between the standard sample peak area and the measured sample peak area (absolute calibration curve method). The standard sample was prepared by accurately weighing the pre-sorted ester cyclic trimer and dissolving it in DMF accurately weighed.

(11) Evaluation Method of Adhesive Layer Base Material Adhesion Layer A pressure-sensitive adhesive layer side of an A4 size laminated polyester film and an A4 size film without the adhesive layer of Comparative Example 1 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) ) Is A, and when adhesive residue is present (when the adhesion of the adhesive layer to the substrate is poor) is B.

(12) Method for evaluating migration of adhesive layer to adherend Adhesive layer surface of laminated film of the present invention having a width of 5 cm on the surface of a polymethyl methacrylate plate (Kuraray Co., Ltd., Como Glass (registered trademark), thickness 1 mm) The film was pressed and reciprocated twice with a 2 cm rubber roller having a width of 5 cm, attached, treated 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 trace on the polymethylmethacrylate plate (no migration of the adhesive layer), B when a very thin trace is observed when staring for 3 seconds under a fluorescent lamp, and a thin trace The case where C is observed, the case where clear white marks are partially observed such as the edge where the film is attached (the adhesive layer has moved) D, the case where clear white marks are observed over the entire surface E. In addition, when not sticking to a to-be-adhered body, it described as "-". 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 0.63 and an amount of diethylene glycol of 2 mol% was obtained.

<Method for producing polyester (B)>
The polyester (A) is pre-crystallized at 160 ° C. in advance and then solid-phase polymerized in a nitrogen atmosphere at a temperature of 210 ° C. to have an intrinsic viscosity of 0.72 and an ester cyclic trimer content of 0.50% by weight. Polyester (B) was obtained.

<Method for producing polyester (C)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and magnesium acetate tetrahydrate as a catalyst were subjected to an esterification reaction at 225 ° C. in a nitrogen atmosphere at 900 ppm with respect to the produced polyester. Subsequently, 3500 ppm of orthophosphoric acid was added to the produced polyester, and 70 ppm of germanium dioxide was added to the produced polyester. The temperature was raised to 280 ° C. over 2 hours and 30 minutes, and the pressure was reduced to an absolute pressure of 0.4 kPa. After 85 minutes of melt polycondensation, polyester (C) having an intrinsic viscosity of 0.64, a diethylene glycol amount of 2 mol%, and an ester cyclic trimer content of 0.98 wt% was obtained.

<Method for producing polyester (D)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 0.09 parts by weight of magnesium acetate tetrahydrate as a catalyst are taken in the reactor, the reaction start temperature is 150 ° C., and the reaction temperature is gradually increased as methanol is distilled off. The temperature was 230 ° C. after 3 hours. After 4 hours, the transesterification reaction was substantially terminated. After adding 300 ppm of ethyl acid phosphate to the resulting polyester to this reaction mixture, adding 300 ppm of antimony trioxide to the resulting polyester, performing a polycondensation reaction for 4 hours, and gradually raising the temperature from 230 ° C. The temperature was 280 ° C. On the other hand, the pressure is gradually reduced from normal pressure, and finally 0.3 mmHg. After the start of the reaction, due to the change in stirring power of the reaction tank, the intrinsic viscosity is 0.65, the amount of diethylene glycol is 3 mol%, the ester cyclic trimer A polyester (D) having a body content of 0.97% by weight was obtained.

<Method for producing polyester (E)>
Polyester (D) was pre-crystallized at 160 ° C. in advance, and then solid-phase polymerized in a nitrogen atmosphere at a temperature of 220 ° C., with an intrinsic viscosity of 0.75 and an ester cyclic trimer content of 0.46 wt% Polyester (E) was obtained.

<Method for producing polyester (F)>
In the production method of polyester (D), 200 ppm of antimony trioxide is added to the produced polyester, and the intrinsic viscosity is 0.62, according to the production method of polyester (D), except that the polycondensation reaction time is lengthened. Was a polyester (F) having a content of 3 mol% and an ester cyclic trimer content of 0.98 wt%.

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

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

Examples of compounds constituting the adhesive layer and the functional layer are as follows.
(Example compounds)
・ 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 point: −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 (% by 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 (% by weight)

-Urethane resin: (IK)
Polyurethane polyol having a number average molecular weight of 2000 / polyethylene glycol / butanediol having a number average molecular weight of 400 comprising 1,6-hexanediol and diethyl carbonate, an aqueous dispersion of urethane resin (glass transition point: −30 ° C.) having the following composition: Isophorone diisocyanate / dimethylolpropionic acid = 83/2/2/11/2 (% by weight)

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

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

・ 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 point: 40 ° C.) having the following composition: ethyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 48/45/4/3 (% by weight)
-Urethane resin: (IIIE)
Water dispersion of urethane resin (glass transition point: 50 ° C.) having the following composition: Isophorone diisocyanate / terephthalic acid / isophthalic acid / ethylene glycol / diethylene glycol / dimethylolpropanoic acid = 12/19/18/21/25/5 (mol) %)

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

・ Compound having an ammonium group: (VA)
Polymer polymerized by the following composition: 2- (trimethylammonio) ethyl methacrylate / butyl methacrylate / ethyl methacrylate = 75/15/10 (% by weight), a copolymer having a counter ion of monomethyl sulfate ion. Number average molecular weight 150,000.

・ Compounds containing ammonium groups: (VB)
Poly (trimethylammonium ethyl methacrylate / methanesulfonate). Number average molecular weight 30000

・ Compounds containing ammonium groups: (VC)
Poly (diallyldimethylammonium chloride) having a pyrrolidinium ring in the main chain. Number average molecular weight 30000.

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

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

Example 1:
A mixed raw material in which polyesters (B), (C), and (G) were mixed in proportions of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and polyesters (A) and (C) were each 97 %, 3% of the mixed raw material is used as an intermediate layer raw material, each is supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. 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. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 90 nm, and coating liquid B1 shown in Table 3 below is applied to the opposite surface so that the film thickness (after drying) of the functional layer is 30 nm, and guided to a tenter at 95 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the lateral direction, heat treated at 230 ° C. for 10 seconds, relaxed by 2% in the lateral direction, 25 μm thick, and Sa on the surface of the adhesive layer A 9 nm polyester film was obtained. When the adhesive layer was removed with ethyl acetate, Sa on the polyester surface side where the adhesive layer was present was 9 nm.

  When the finished polyester film was evaluated, the adhesive strength with the polymethyl methacrylate plate was 10 mN / cm, the adhesive property was good, the amount of ester cyclic trimer precipitated was small, and there was no concern about process contamination. It was. The properties of this film are shown in Table 4 below.

Examples 2-163:
In Example 1, it manufactured like Example 1 except having changed an application agent composition into an application agent composition shown in Tables 1-3, and obtained a polyester film. As shown in Tables 4 to 8 below, the finished polyester film had good adhesive strength and was also good with a small amount of ester cyclic trimer.

Example 164:
A mixed raw material in which polyesters (A), (C), and (G) were mixed in proportions of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and polyesters (A) and (C) were each 97 %, 3% of the mixed raw material is used as an intermediate layer raw material, each is supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. 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. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 150 nm, and coating liquid B1 shown in Table 3 below is applied to the opposite surface so that the film thickness (after drying) of the functional layer is 30 nm, and guided to a tenter at 95 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the lateral direction, heat treated at 230 ° C. for 10 seconds, relaxed by 2% in the lateral direction, 25 μm thick, and Sa on the surface of the adhesive layer A 9 nm polyester film was obtained. When the adhesive layer was removed with ethyl acetate, Sa on the polyester surface side where the adhesive layer was present was 9 nm.

  When the finished polyester film was evaluated, the adhesive strength with the polymethylmethacrylate plate was 20 mN / cm, the adhesive property was good, the amount of ester cyclic trimer precipitated was small, and there was no concern about process contamination. It was. The properties of this film are shown in Table 9 below.

Examples 165-192:
In Example 164, it manufactured like Example 164 except having changed the coating composition into the coating composition shown in Tables 1-3, and obtained the polyester film. As shown in Table 9 below, the finished polyester film had good adhesive strength and was also good with a small amount of ester cyclic trimer.

Example 193:
A mixed raw material in which polyesters (E) and (H) are mixed at a ratio of 94% and 6%, respectively, is used as a raw material for the outermost layer (surface layer), and polyester (D) is used as a raw material for the intermediate layer in each of two extruders. After each was melted at 285 ° C., it was coextruded and cooled on a cooling roll set at 40 ° C. in a layer configuration of two types and three layers (surface layer / intermediate layer / surface layer = 5: 15: 5 discharge amount). Solidified to obtain an unstretched film. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 150 nm, and coating liquid B1 shown in Table 3 below is applied to the opposite surface so that the film thickness (after drying) of the functional layer is 30 nm, and guided to a tenter at 95 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the lateral direction, heat treated at 230 ° C. for 10 seconds, relaxed by 2% in the lateral direction, 25 μm thick, and Sa on the surface of the adhesive layer A 9 nm polyester film was obtained. When the adhesive layer was removed with ethyl acetate, Sa on the polyester surface side where the adhesive layer was present was 9 nm.

  When the finished polyester film was evaluated, the adhesive strength with the polymethylmethacrylate plate was 20 mN / cm, the adhesive property was good, the amount of ester cyclic trimer precipitated was small, and there was no concern about process contamination. It was. The properties of this film are shown in Table 10 below.

Examples 194-221:
In Example 193, it manufactured like Example 193 except having changed the coating composition into the coating composition shown in Tables 1-3, and obtained the polyester film. As shown in Table 10 below, the completed polyester film had good adhesive strength and was also good with a small amount of ester cyclic trimer.

Example 222:
The mixed raw materials in which the polyesters (F) and (H) are mixed at a ratio of 94% and 6% are used as the outermost layer (surface layer) raw material, and the polyester (F) is used as the intermediate layer raw material in each of the two extruders. After each was melted at 285 ° C., it was coextruded and cooled on a cooling roll set at 40 ° C. in a layer configuration of two types and three layers (surface layer / intermediate layer / surface layer = 5: 15: 5 discharge amount). Solidified to obtain an unstretched film. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 150 nm, and coating liquid B1 shown in Table 3 below is applied to the opposite surface so that the film thickness (after drying) of the functional layer is 30 nm, and guided to a tenter at 95 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the lateral direction, heat treated at 230 ° C. for 10 seconds, relaxed by 2% in the lateral direction, 25 μm thick, and Sa on the surface of the adhesive layer A 9 nm polyester film was obtained. When the adhesive layer was removed with ethyl acetate, Sa on the polyester surface side where the adhesive layer was present was 9 nm.

  When the finished polyester film was evaluated, the adhesive strength with the polymethylmethacrylate plate was 20 mN / cm, the adhesive property was good, the amount of ester cyclic trimer precipitated was small, and there was no concern about process contamination. It was. The properties of this film are shown in Table 11 below.

Examples 223-250:
In Example 222, it manufactured similarly to Example 222 except having changed the coating composition into the coating composition shown in Tables 1-3, and obtained the polyester film. As shown in the following Table 11, the finished polyester film had good adhesive force and a slightly larger amount of ester cyclic trimer was observed, but it was good as a whole.

Example 251
A mixed raw material in which polyesters (D) and (H) are mixed at a ratio of 94% and 6%, respectively, is used as a raw material for the outermost layer (surface layer), and polyester (D) is used as a raw material for the intermediate layer in each of two extruders. After each was melted at 285 ° C., it was coextruded and cooled on a cooling roll set at 40 ° C. in a layer configuration of two types and three layers (surface layer / intermediate layer / surface layer = 5: 15: 5 discharge amount). Solidified to obtain an unstretched film. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 150 nm, and coating liquid B1 shown in Table 3 below is applied to the opposite surface so that the film thickness (after drying) of the functional layer is 30 nm, and guided to a tenter at 95 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the lateral direction, heat treated at 230 ° C. for 10 seconds, relaxed by 2% in the lateral direction, 25 μm thick, and Sa on the surface of the adhesive layer A 9 nm polyester film was obtained. When the adhesive layer was removed with ethyl acetate, Sa on the polyester surface side where the adhesive layer was present was 9 nm.

  When the finished polyester film was evaluated, the adhesive strength with the polymethylmethacrylate plate was 20 mN / cm, the adhesive property was good, the amount of ester cyclic trimer precipitated was small, and there was no concern about process contamination. It was. The properties of this film are shown in Table 12 below.

Examples 252 to 277:
In Example 251, it manufactured like Example 251 except having changed an application agent composition into an application agent composition shown in Tables 1-3, and obtained a polyester film. As shown in Table 12 below, the finished polyester film had good adhesive strength and was also good with little precipitation of ester cyclic trimer.

Example 278:
In Example 1, it manufactured similarly to Example 1 except having not provided the adhesion layer, and obtained the polyester film. On the polyester film without the adhesive layer, the coating liquid A21 shown in Table 1 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 by offline coating. A polyester film having an adhesive layer laminated thereon was obtained. As shown in Table 12, the finished polyester film had good adhesive strength and was good with a small amount of ester cyclic trimer. However, the adhesion of the adhesive layer to the substrate and the transferability to the adherend were not good.

Example 279:
In Example 278, except having changed the composition of the adhesion layer into the composition shown in Table 2, it manufactured like Example 278 and obtained the polyester film. As shown in Table 12 below, the finished polyester film had good adhesive force and good precipitation amount of the ester cyclic trimer, but the adhesion of the adhesive layer to the base material and transferability to the adherend Was not good.

Comparative Example 1:
In Example 1, it manufactured like Example 1 except not having provided an adhesion layer and a functional layer, and obtained a polyester film. When the completed polyester film was evaluated, as shown in Table 13 below, it was a film having no adhesive force.

Comparative Examples 2 to 13:
In Example 1, it manufactured like Example 1 except having changed an application agent composition into an application agent composition shown in Tables 1-3, and obtained a polyester film. As shown in Table 13, the finished polyester film was a film having no adhesive force, or a large amount of ester cyclic trimer precipitated, and there were cases where there was a concern such as process contamination.

Comparative Examples 14 and 15:
A polyester film was obtained in the same manner as in Example 251 except that the coating composition was changed to the coating composition shown in Tables 1 and 2 in Example 251. As shown in Table 13, the finished polyester film was a film having a large amount of ester cyclic trimer and a concern about process contamination.

Comparative Example 16
On the polyester film without the adhesive layer and functional layer obtained in Comparative Example 1, the coating liquid A21 shown in Table 1 below was applied at 100 ° C. for 3 minutes so that the film thickness (after drying) of the adhesive layer was 20 μm. Drying was performed to obtain a polyester film having an adhesive layer formed by off-line coating. When the polyester film was cut after bonding the pressure-sensitive adhesive layer side, the component of the pressure-sensitive adhesive layer that was not seen in the examples was seen 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 13.

  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 can be suitably used for applications that are excellent in mechanical strength and heat resistance, have a small amount of oligomer precipitation after heat treatment, and need to have good adhesive properties.

Claims (17)

It has an adhesive layer containing a resin having a glass transition point of 0 ° C. or less and a film thickness in the range of 1 nm to 5 μm on one surface of the polyester film, and the film surface opposite to the adhesive layer is 180 ° C. A laminated polyester film, wherein the amount of ester cyclic trimer precipitated on the surface when heat-treated for 30 minutes is 5.0 mg / m ² or less. The laminated polyester film according to claim 1, wherein the polyester film has a polyester layer having an ester cyclic trimer content of 0.7% by weight or less. The laminated polyester film according to claim 2, wherein the polyester layer having a content of the ester cyclic trimer of 0.7% by weight or less has a film thickness of 2 μm or more. The laminated polyester film according to any one of claims 1 to 3, wherein the resin having a glass transition point of 0 ° C or lower is at least one selected from polyester resins, acrylic resins, and urethane resins. The laminated polyester film according to claim 4, 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 4 or 5, wherein the polyester resin contains sulfonic acid, sulfonate, carboxylic acid, or carboxylate as a functional group. The laminated polyester film according to any one of claims 4 to 6, wherein the polyester resin contains an aromatic polyvalent carboxylic acid as a constituent component. The laminated polyester film according to claim 4, comprising an alkyl (meth) acrylate having an alkyl group having 4 to 30 carbon atoms as a monomer constituting the acrylic resin. The laminated polyester film according to claim 4 or 8, wherein the monomer constituting the acrylic resin contains a compound having 2 or less carbon atoms or a compound having a cyclic structure at the ester terminal. The content of the monomer having a glass transition point of 0 ° C. or less when the homopolymer is composed of the monomers constituting the acrylic resin is 30% by weight or more as a ratio with respect to the entire acrylic resin. The laminated polyester film according to any one of the above. The laminated polyester film according to claim 4, wherein the acrylic resin has a carboxylic acid group, a carboxylic acid group, a sulfonic acid group, a sulfonic acid group, or a hydroxyl group. The laminated polyester film according to claim 4, wherein the urethane resin contains a polycarbonate polyol or a polyether polyol as a polyol component. The laminated polyester film according to any one of claims 1 to 12, wherein the adhesive layer contains a crosslinking agent. The laminated polyester film according to any one of claims 1 to 13, which has a functional layer on the side of the polyester film opposite to the adhesive layer. The laminated polyester film according to claim 14, wherein the functional layer contains a compound having an ammonium group, a crosslinking agent, polyvinyl alcohol, or a metal compound. The laminated polyester film according to claim 14 or 15, wherein the functional layer has a thickness in the range of 1 nm to 3 µm. The laminated polyester film according to any one of claims 1 to 16, wherein an arithmetic average roughness (Sa) of the adhesive layer surface is 50 nm or less.