JP6750598B2 - Method for producing laminated polyester film. - Google Patents

Description

The present invention relates to a laminated polyester film, for example, a resin plate, a metal plate, etc. during transportation, as a surface protection film for preventing scratches and dirt adhesion during storage and processing, etc. The present invention relates to a laminated polyester film having excellent mechanical strength and heat resistance, little dust adhesion, and good adhesive properties.

Conventionally, resin plates, metal plates, glass plates, etc. are protected from scratches and stains during transportation, storage, and processing, and scratches during processing of liquid crystal panels, polarizing plates, and other electronic parts. A wide range of surface protection films are used in applications such as prevention of dust and dirt adhesion, prevention of dirt adhesion during transportation and storage of cars, protection of automobile coating from acid rain, protection of flexible printed circuit boards during plating and etching. It is used.

These surface protective films, such as resin plate, metal plate and glass plate, have appropriate adhesive force to the adherend during transportation, storage or processing of various adherends, It is required that the surface of the adherend is protected by being attached to the surface of the adherend and easily peeled off after the end of the purpose. In order to overcome these problems, it has been proposed to use a polyolefin film for surface protection (Patent Documents 1 and 2).

However, since a polyolefin-based film is used as the surface protection film base material, it is not possible to remove defects caused by gel-like substances and deteriorated products caused by the film base material, which are generally called fish eyes, For example, when inspecting an adherend with the surface protection film attached, there is a problem that a defect of the surface protection film is detected.

Further, as the base material of the surface protection film, a film having a certain degree of mechanical strength is required so that the base material will not be stretched due to tension during various processes such as bonding with an adherend. However, since a polyolefin-based film generally has poor mechanical strength, it has a drawback that it is not suitable for high-tensile processing due to an increase in processing speed in order to emphasize productivity.

Further, even when the processing temperature is increased to improve the processing speed and various characteristics, the polyolefin-based film does not have excellent shrinkage stability due to heat, and thus has poor dimensional stability. Therefore, there is a demand for a film that is less likely to be thermally deformed even when processed at high temperatures and has excellent dimensional stability.

In addition, plastic films generally have the drawback that static electricity is generated during peeling or by friction (peeling electrification or triboelectric electrification), and dust adheres to them, especially in applications where foreign matter is disliked, for example, in optical devices such as polarizing plates. This is a problem when used as a protective film in the manufacturing process of a member.

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

The present invention has been made in view of the above circumstances, the problem to be solved is to be used for various surface protection films and the like, less fish eyes, excellent mechanical strength and heat resistance, less dust adhesion, The object is to provide a laminated polyester film having good adhesive properties.

The present inventor, as a result of earnest studies in view of the above circumstances, has found that the above-mentioned problems can be easily solved by using a laminated polyester film having a specific configuration, and has completed the present invention.

That is, the gist of the present invention is to produce a laminated polyester film having a pressure-sensitive adhesive layer containing a resin having a glass transition point of 0° C. or less and an antistatic agent and having a film thickness of 10 μm or less on at least one surface of the polyester film. In the method, the resin having a glass transition point of 0° C. or lower is an acrylic resin or a polyester resin, and the adhesive force of the adhesive layer to a polymethylmethacrylate plate is 1 to 5000 mN/cm, and the adhesive layer is formed into a film. In the method of (1), the laminated polyester film is formed by in-line coating, and then stretched in at least one direction and heat-treated.

According to the laminated polyester film of the present invention, as various surface protection films, there are few fish eyes, excellent mechanical strength and heat resistance, less adhesion of dust, it is possible to provide a film having good adhesive properties, Its industrial value is high.

We believe that it is necessary to significantly change the base material of the base film to reduce fish eyes, improve mechanical strength, and improve heat resistance, and as a result of various studies, it is significantly different from the conventional polyolefin-based materials. It has been found that this can be achieved by using a polyester material. However, by largely changing the material system of the base film, the adhesive property was significantly lowered, and it became impossible to achieve it with a general polyester film. Therefore, the present invention has been achieved by providing an adhesive layer on the substrate film for improvement.

The polyester film constituting the laminated polyester film may have a single-layer structure or a multi-layer structure, and may have a four-layer structure or a multi-layer structure other than the two-layer structure and the three-layer structure as long as the gist of the present invention is not exceeded. It may be present and is not particularly limited. It is preferable to have a multi-layered structure of two or more layers, each layer having a characteristic so as to have multiple functions.

The polyester used may be a homopolyester or a copolyester. When it is made of homopolyester, it is preferably obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. 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. Polyethylene terephthalate etc. are illustrated as a typical polyester. On the other hand, examples of the dicarboxylic acid component of the copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (eg, p-oxybenzoic acid). One kind or two or more kinds may be mentioned, and the glycol component may be one kind or two or more kinds such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexanedimethanol, neopentyl glycol.

From the viewpoint of forming a film that can withstand various processing conditions, it is preferable that the mechanical strength and heat resistance (dimensional stability by heating) be high, and for that purpose, it may be preferable that the copolymerized polyester component is small. Specifically, the proportion of the monomer forming the copolyester in the polyester film is preferably 10 mol% or less, more preferably 5 mol% or less, and further preferably produced as a by-product during homopolyester polymerization. The amount of diether component is 3 mol% or less. More preferable form of polyester is, in consideration of mechanical strength and heat resistance, among the compounds, a film formed from polyethylene terephthalate or polyethylene naphthalate, which is formed by polymerization from terephthalic acid and ethylene glycol, is more preferable. A film formed of polyethylene terephthalate is more preferable in consideration of ease of use and handleability as a surface protection film.

The polymerization catalyst for polyester is not particularly limited, and conventionally known compounds can be used, and examples thereof include antimony compounds, titanium compounds, germanium compounds, manganese compounds, aluminum compounds, magnesium compounds, calcium compounds and the like. Among these, the antimony compound is preferable because it is inexpensive, and the titanium compound and the germanium compound have high catalytic activity and can be polymerized in a small amount, and the amount of metal remaining in the film is small, so that the film Is preferable because it has high transparency. Furthermore, since a germanium compound is expensive, it is more preferable to use a titanium compound.

In the case of polyester using a titanium compound, the titanium element content is preferably 50 ppm or less, more preferably 1 to 20 ppm, further preferably 2 to 10 ppm. If the content of the titanium compound is too large, the deterioration of the polyester may be accelerated in the step of melt-extruding the polyester to form a yellowish film, and if the content is too small, the polymerization efficiency is poor and the cost is low. In some cases, it is difficult to obtain a film having a sufficient strength or sufficient strength. Further, when a polyester containing a titanium compound is used, it is preferable to use a phosphorus compound to reduce the activity of the titanium compound for the purpose of suppressing deterioration in the melt extrusion step. As the phosphorus compound, orthophosphoric acid is preferable in consideration of the productivity and heat 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 further 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 high, it may cause gelation or foreign matter, and if the content is too low, the activity of the titanium compound cannot be sufficiently lowered, and the yellowish color It may be a film.

Particles may be incorporated into the polyester layer for the purpose of imparting slipperiness, preventing scratches in each step, and improving blocking resistance. When the particles are blended, the type of the particles to be blended is not particularly limited as long as they are particles capable of imparting slipperiness, and specific examples include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, and 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, during the polyester manufacturing process, it is also possible to use precipitated particles in which a part of a metal compound such as a catalyst is precipitated and finely dispersed. Among these, silica particles and calcium carbonate particles are preferable because the effect is easily obtained even in a small amount.

The average particle size of the particles is preferably 10 μm or less, more preferably 0.01 to 5 μm, and further preferably 0.01 to 3 μm. When the average particle size exceeds 10 μm, there may be a concern that the film may be deteriorated in transparency.

Further, the content of particles in the polyester layer cannot be generally determined because there is a balance with the average particle size of the particles, but it is preferably 5% by weight or less, more preferably 0.0003 to 3% by weight, and further preferably Is in the range of 0.0005 to 1% by weight. When the content of particles exceeds 5% by weight, problems such as falling of particles and deterioration of transparency of the film may be concerned. When there are no particles or when there are few particles, the slipperiness may be insufficient. Therefore, it may be necessary to take measures such as improving the slipperiness by incorporating particles into the adhesive layer.

The shape of the particles to be used is not particularly limited, and may be spherical, lumpy, rod-shaped, flattened, or the like. Further, the hardness, specific gravity, color, etc. are not particularly limited.
Two or more kinds of these series of particles may be used in combination, if necessary.

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 of producing the polyester constituting each layer, but it is preferably added after the completion of the esterification or transesterification reaction.

In addition to the above-mentioned particles, conventionally known ultraviolet absorbers, antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments and the like can be added to the polyester film, if 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 further preferably 8 to 75 μm.

Although a film production example will be specifically described, the film production method is not limited to the following production examples, and a commonly known film forming method can be adopted. Generally, a resin is melted, formed into a sheet, and stretched for the purpose of increasing the strength and the like to form a film. For example, when producing a biaxially stretched polyester film, first, a polyester raw material is melt-extruded from a die using an extruder, and a molten sheet is cooled and solidified by a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to increase the adhesion between the sheet and the rotary cooling drum, and the electrostatic application adhesion method or the liquid application adhesion method is preferably adopted. Next, the obtained unstretched sheet is stretched in one direction by a roll or 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. Then, it is stretched in a direction orthogonal to the stretching direction in the first stage, preferably at 70 to 170° C., and at a stretching ratio of preferably 2.5 to 7 times, more preferably 3.0 to 6 times. A method of obtaining a biaxially oriented film by subsequently performing heat treatment at a temperature of 180 to 270° C. under tension or under relaxation within 30% can be mentioned. In the above stretching, it is possible to employ a method in which stretching in one direction is performed in two or more stages. In that case, it is preferable that the stretching ratios in the two directions finally fall within the above ranges.

Further, the simultaneous biaxial stretching method can be adopted for producing the polyester film constituting the laminated polyester film. The simultaneous biaxial stretching method is a method in which the unstretched sheet is usually stretched and oriented in the machine direction and the width direction at 70 to 120° C., preferably 80 to 110° C. in a temperature controlled state at the same time. Is an area magnification of 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Then, subsequently, heat treatment is performed at a temperature of 180 to 270° C. under tension or under relaxation within 30% to obtain a stretched and oriented film. With regard to the simultaneous biaxial stretching device that employs the above-described stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be adopted.

Next, the formation of the adhesive layer constituting the laminated polyester film will be described. Examples of the method for forming the adhesive layer include methods such as coating, transfer and laminating. Considering the ease of forming the adhesive layer, it is preferably formed by coating.

As a method of coating, it may be provided by in-line coating, which is performed in the process of film production, 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, in-line coating is a method of performing coating at any stage from melt extrusion of a resin forming a film to stretching, stretching, heat setting, 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 before winding after heat setting. Although not limited thereto, for example, in successive biaxial stretching, a method of coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) and then stretching in the transverse direction is excellent. According to such a method, it is possible to perform film formation and adhesive layer formation at the same time, which is advantageous in terms of manufacturing cost. Further, in order to perform stretching after coating, it is possible to change the thickness of the adhesive layer depending on the stretching ratio. Thin film coating can be performed more easily than offline coating.

Further, by providing the pressure-sensitive adhesive layer on the film before stretching, the pressure-sensitive adhesive layer can be stretched together with the base film, whereby the pressure-sensitive adhesive layer can be firmly adhered to the base film. Furthermore, in the production of a biaxially stretched polyester film, the film can be constrained in the longitudinal and transverse directions by stretching while gripping the film end portion with a clip or the like, and a flat surface without wrinkles or the like in the heat setting step. High temperature can be applied while maintaining the sex.

Therefore, since the heat treatment applied after coating can be performed at a high temperature that cannot be achieved by other methods, the film-forming property of the adhesive layer is improved, and the adhesive layer and the base film can be more firmly adhered. Furthermore, it can be a strong adhesive layer. Especially, it is very effective for reacting a crosslinking agent.

According to the above in-line coating process, the film size does not change significantly depending on the presence or absence of the adhesive layer, and the risk of scratches or foreign matter does not change significantly depending on the presence or absence of the adhesive layer. This is a great advantage over offline coating which is performed one extra. Furthermore, as a result of various studies, it was found that in-line coating has an advantage that adhesive residue can be reduced, which is a migration of components of the adhesive layer when the film of the present invention is attached to an adherend. It was It is considered that this is because the heat treatment can be performed at a high temperature which cannot be obtained by the off-line coating, and the adhesive layer and the base film are more firmly adhered.

In the present invention, it is an essential requirement to have an adhesive layer containing a resin having a glass transition point of 0° C. or less and an antistatic agent and having a film thickness of 10 μm or less.

It has been found that by using a resin having a glass transition point of 0° C. or lower, it is possible to impart appropriate adhesive properties to the polyester film. As the resin having a glass transition point of 0° C. or lower, a conventionally known resin can be used. Specific examples of the resin include polyester resin, acrylic resin, urethane resin, polyvinyl resin (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.) and the like. Among them, polyester resin is particularly preferable in consideration of adhesive property and coatability. , Acrylic resin and urethane resin are preferred. Furthermore, in consideration of stronger adhesive properties and reusability of the film, polyester resin and acrylic resin are preferable, and also when considering adhesion to the polyester film as a base material and bonding to a polyester material. Is a polyester resin, and acrylic resin is the most preferable in consideration of strong adhesive properties, bonding to acrylic materials, reduction of migration of adhesive components (adhesive residue) to the adherend, and blocking properties with the back side. ..

Examples of the polyester resin include 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-sodiumsulfoisophthalic 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 their ester-forming derivatives can be used. Examples of polyhydric hydroxy compounds are ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 2 -Methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexane dimethanol, 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 dimethylethylsulfonate, dimethylolpropion Potassium acid or the like can be used. One or more may be appropriately selected from these compounds, and the polyester resin may be synthesized by a conventional polycondensation reaction.

Among the above, in order to lower the glass transition point to 0° C. or lower, it is preferable to contain an aliphatic polycarboxylic acid or an aliphatic polyhydroxy compound as a constituent component. In general, polyester resins are composed of aromatic polycarboxylic acids and polyhydroxy compounds including aliphatic compounds. Therefore, in order to lower the glass transition point than general polyester resins, it is necessary to use aliphatic polyhydric compounds. It is effective to contain a carboxylic acid. From the viewpoint of lowering the glass transition point, the aliphatic polycarboxylic acid preferably has a long carbon number, and preferably has 6 or more carbon atoms (adipic acid), more preferably 8 or more carbon atoms, and further preferably 10 or more carbon atoms. The upper limit of the preferable range is 20.

From the viewpoint of improving adhesive properties, the content of the aliphatic polycarboxylic acid in the acid component of the polyester resin is preferably 2 mol% or more, more preferably 4 mol% or more, and further preferably 6 mol%. As described above, particularly preferably 10 mol% or more, and the upper limit of the preferable range is 50 mol %.

In the aliphatic polyhydroxy 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 30 mol% or more.

In consideration of suitability for in-line coating, it is preferable to use an aqueous system, and therefore, it is preferable that the polyester resin contains sulfonic acid, sulfonic acid metal salt, carboxylic acid, and carboxylic acid metal salt. In particular, sulfonic acid and a metal salt of sulfonic acid are preferable, and a metal salt of sulfonic acid is particularly preferable, from the viewpoint of good dispersibility in water.

When the above sulfonic acid, sulfonic acid metal salt, carboxylic acid, or carboxylic acid metal salt is used, the content in the acid component constituting the polyester resin is preferably 0.1 to 10 mol %, more preferably 0.1. It is in the range of 2 to 8 mol %. When used in the above range, the dispersibility in water becomes good.

Further, in consideration of the coating appearance in the in-line coating coating layer, the adhesion and blocking to the polyester film, and further reduction of the adhesive residue on the adherend when used as a surface protection film, as the acid component in the polyester resin, It is preferable to contain a certain amount of aromatic polycarboxylic acid. As a proportion of the acid component in the polyester resin, the aromatic polycarboxylic acid is preferably in the range of 30 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, and the upper limit of the preferred range Is 98 mol %. In addition, 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. Further, in order to further improve the adhesive property, it is more preferable to use two or more kinds of aromatic polycarboxylic acid in combination.

As the glass transition point of the polyester resin for improving the adhesive property, 0° C. or lower is essential, preferably −10° C. or lower, more preferably −20° C. or lower, and the lower limit of the preferable range is − It is 60°C. By using in the above range, it becomes easy to obtain a film having optimum adhesive properties.

The acrylic resin is a polymer composed of a polymerizable monomer containing an acrylic or methacrylic monomer (hereinafter, acrylic and methacrylic may be collectively referred to as (meth)acrylic). These may be homopolymers or copolymers, and further copolymers with polymerizable monomers other than acrylic and methacrylic monomers.

Also included are copolymers of these polymers with other polymers (eg, polyester, polyurethane, etc.). For example, it is a block copolymer or a graft copolymer. Alternatively, the polymer (polymer mixture in some cases) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer (polymer mixture in some cases) obtained by polymerizing a polymerizable monomer in a polyurethane solution or polyurethane dispersion is also included. Similarly, the polymer (polymer mixture in some cases) obtained by polymerizing the polymerizable monomer in another polymer solution or dispersion is also included. However, considering adhesive properties and adhesive residue on the adherend, it should not contain other polymers such as polyester and polyurethane (polymerizable monomer containing carbon-carbon double bond (whether homopolymer or copolymer) (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, monobutylhydroxyfumarate, monobutylhydroxyitaconate 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 (Meth)acrylic acid esters; various nitrogen-containing compounds such as (meth)acrylamide, diacetone acrylamide, N-methylol acrylamide or (meth)acrylonitrile; styrene, α-methylstyrene, divinylbenzene, vinyltoluene Various vinyl esters such as various styrene derivatives, vinyl propionate, vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and the like; phosphorus-containing vinyl Examples thereof include various monomers, various vinyl halides such as vinyl chloride and vinylidene 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)acryl-based homopolymer having a glass transition point 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.), normalnonyl methacrylate (glass transition point: −35° C.), isononyl 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 meta. Acrylate (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 can be mentioned.

Among the above, in order to improve the adhesive property, the number of carbon atoms of the alkyl group is preferably 4 or more, more preferably 4 to 30, further preferably 4 to 20 and particularly preferably 4 to 14. The range is alkyl (meth)acrylate. Industrially mass-produced, the (meth)acrylic resin containing normal butyl acrylate and 2-ethylhexyl acrylate is the most suitable from the viewpoint of handleability and supply stability.

The content of the (meth)acrylate unit having an alkyl group having 4 or more carbon atoms at the ester terminal in the (meth)acrylic resin is preferably 20% by weight or more, more preferably 35 to 99% by weight, and further preferably 50% by weight. ˜98 wt %, particularly preferably 65-95 wt %, most preferably 75-90 wt %. The larger the content of the (meth)acrylate unit having an alkyl group having 4 or more carbon atoms at the ester terminal, the stronger the adhesive property. On the other hand, if the content is too small, the adhesive strength may be insufficient.

In the (meth)acrylic resin, the content of the (meth)acrylate unit having a homopolymer glass transition point of 0° C. or lower and having an alkyl group having a carbon number of less than 4 at the ester terminal is preferably 50% by weight. The range is preferably 40% by weight or less, more preferably 30% by weight or less. When used in the above range, good adhesive properties are obtained.

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

The content of the compound unit containing 2 or less carbon atoms at the ester terminal in the (meth)acrylic resin is preferably 50% by weight or less, more preferably 1 to 40% by weight, and further preferably 3 to 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 adhesive property in an appropriate range without significantly deteriorating the adhesive property, and conversely, if the content is large, the adhesive property to the adherend is large. It is possible to reduce the migration of the adhesive component. Therefore, if it is within the above range, it is easy to achieve the two purposes of the adhesive property and the migration reduction.

The content of the compound unit having a cyclic structure in the (meth)acrylic resin is preferably 50% by weight or less, more preferably 1 to 45% by weight, still more preferably 5 to 40% by weight. If the content of the unit is small, it is possible to impart an adhesive property in an appropriate range without significantly deteriorating the adhesive property, and conversely, if the content is large, the adhesive property to the adherend is large. It is possible to reduce the migration of the adhesive component. Therefore, if it is within the above range, it is easy to achieve the two purposes of the adhesive property and the migration reduction.

From the viewpoint of adhesive properties, the content of a monomer having a glass transition point of a homopolymer of 0° C. or less as a monomer constituting a (meth)acrylic resin is preferably 30% by weight as a ratio to the entire (meth)acrylic resin. The above range is more preferably 45% by weight or more, further preferably 60% by weight or more, and particularly preferably 70% by weight or more. The upper limit of the preferable range is 99% by weight. Good adhesive properties are likely to be obtained by using in this range.

Further, the glass transition point of a monomer having a homopolymer glass transition point of 0° C. or lower, which improves adhesive properties, is preferably −20° C. or lower, more preferably −30° C. or lower, and further preferably −40° C. or lower. , Particularly preferably -50°C or lower, and the lower limit of the preferable range is -100°C. By using in this range, it becomes easy to obtain a film having suitable adhesive properties.

As a more optimal form of the (meth)acrylic resin for improving the adhesive property, the total content of normal butyl acrylate and 2-ethylhexyl acrylate in the (meth)acrylic resin is preferably 30% by weight or more. , More preferably 40% by weight or more, further preferably 50% by weight or more, particularly preferably 60% by weight or more, most preferably 70% by weight or more, and the upper limit of the preferable range is 99% by weight. Depending on the composition of the (meth)acrylic resin used and the composition of the pressure-sensitive adhesive layer, 2-ethylhexyl is used particularly when it is desired to eliminate the migration of the pressure-sensitive adhesive component to the adherend with a small amount of the crosslinking agent. The content of acrylate is preferably 90% by weight or less, more preferably 80% by weight or less.

Further, in consideration of application to in-line coating and the like, it is possible to introduce various hydrophilic functional groups in order to obtain a water-based (meth)acrylic resin. Preferable 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, and among them, the carboxylic acid group, the carboxylic acid group and the hydroxyl group are preferable from the viewpoint of water resistance.

Examples of the introduction of the 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 the above, acrylic acid and methacrylic acid are preferable because they can effectively disperse in water.

As the introduction of the hydroxyl group, various kinds of hydroxyl groups such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutylhydroxy fumarate and monobutylhydroxy itaconate are introduced. Examples thereof include copolymerizing a hydroxyl group-containing monomer. Among the above, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferable in view 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 the crosslinking reaction group. is there. However, if the content is too large, the adhesive properties are affected, so it is necessary to use an appropriate amount.

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, further preferably 2 to 15% by weight, particularly preferably 3 to 10% by weight. The range is. Use in the above range facilitates water-based development.

The glass transition point of the (meth)acrylic resin for improving the adhesive property is essentially 0° C. or lower, preferably −10° C. or lower, more preferably −20° C. or lower, and further preferably The temperature is in the range of -30°C or lower, and the lower limit of the preferable range is -80°C. By using in the above range, it becomes easy to obtain a film having optimum adhesive properties. Further, when it is necessary to consider reduction of migration of the adhesive component to the adherend, the temperature range is preferably −70° C. or higher, more preferably −60° C. or higher, further preferably −50° C. or higher.

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

Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by dealcoholation reaction. Examples of polyhydric alcohols are ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol and 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 Examples thereof include diol, neopentyl glycol, 3-methyl-1,5-pentanediol and 3,3-dimethylolheptane. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and the like. Examples of the polycarbonate-based polyols obtained from these reactions include, for example, poly(1,6-hexylene) carbonate and poly(3-). Methyl-1,5-pentylene) carbonate and the like can be mentioned.

From the viewpoint of improving adhesive properties, the chain-like alkyl chain is a polycarbonate polyol composed of a diol component having a carbon number of preferably 4 to 30, more preferably 4 to 20, and further preferably 6 to 12. , 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are industrially mass-produced and have good handling and supply stability. Optimally, the copolymerized polycarbonate polyol contains at least two kinds of diols selected from the above.

Examples of the 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 property, the monomer forming the polyether has an aliphatic diol having a carbon number of preferably 2 to 30, more preferably 3 to 20, and still more preferably 4 to 12, particularly a straight chain fatty acid. 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. And polyhydric alcohols (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, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyl dialkanolamine, lactone diol, etc.), lactone compounds such as polycaprolactone Examples thereof include those having a derivative unit.

Considering the adhesive property, polycarbonate polyols and polyether polyols are more preferably used among the above polyols, and polycarbonate polyols are particularly preferable.

Examples of the polyisocyanate compound used to obtain 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′. An aliphatic diisocyanate having an aromatic ring such as tetramethylxylylene diisocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, aliphatic diisocyanate such as hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl Examples thereof include alicyclic diisocyanates such as methane diisocyanate and isopropylidene dicyclohexyl diisocyanate. These may be used alone or in combination of two or more.

A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with an isocyanate group, and generally, a hydroxyl group is used. 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, butanediol, xylylene glycol, aromatic glycols such as bishydroxyethoxybenzene, and esters such as neopentyl glycol hydroxypivalate. Mention may be made of 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 decanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isoprobilitin cyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1 And alicyclic diamines such as 3-bisaminomethylcyclohexane.

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

In addition, 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, but a carboxyl group is preferable. As a method of introducing a carboxyl group into the urethane resin, various methods can be adopted in each step of the polymerization reaction. For example, there is a method of using a resin having a carboxyl group as a copolymerization component at the time of prepolymer synthesis, and a method of using a component having a carboxyl group as one component such as a polyol, polyisocyanate, or a chain extender. In particular, a method in which a carboxyl group-containing diol is used and a desired amount of a carboxyl group is introduced by the charged amount of this component is preferable.

For example, copolymerizing dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, etc. with a diol used for the polymerization of urethane resin. You can The carboxyl group is preferably in the form of a salt neutralized with ammonia, amine, alkali metals, inorganic alkalis and 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 with another crosslinking agent. This makes it possible to improve the stability of the liquid state before coating and further improve the durability, solvent resistance, water resistance, blocking resistance and the like of the obtained coating layer.

The glass transition point of the urethane resin for improving the adhesive property is essentially 0° C. or lower, preferably −10° C. or lower, more preferably −20° C. or lower, and further preferably −30° C. It is in the following range, and the lower limit of the preferable range is −80° C. By using in the above range, it becomes easy to obtain a film having optimum adhesive properties.

The antistatic agent is used to reduce the surface resistance of the film surface in order to prevent the adhesion of dust during various processes. The antistatic agent is not particularly limited, and it is possible to use a conventionally known antistatic agent. However, since it is excellent in heat resistance and moist heat resistance, it is a polymer type antistatic agent. preferable. Examples of the polymer type antistatic agent include conductive polymers, compounds having an ammonium group, compounds having a sulfonic acid group, polyether compounds, betaine compounds and the like. Among these, the conductive polymer is preferable from the viewpoint that the surface resistance can be made particularly low and the antistatic performance can be made high. Further, from the viewpoint of being less likely to be colored, a compound having an ammonium group and a compound having a sulfonic acid group are preferable.

Furthermore, as a result of further studies, when a conductive polymer is used as an antistatic agent, it is preferable to use a polyester resin as a resin having a glass transition point of 0° C. or lower in combination with other resins such as acrylic resin and urethane resin. It was found that the antistatic performance is superior to that of the resin and the compatibility with the adhesive force is excellent. In addition, in the case of an antistatic agent other than the conductive polymer, it was also found that the acrylic resin has the best compatibility between the adhesive force and the antistatic performance.

Examples of the conductive polymer include polythiophene-based, polyaniline-based, polypyrrole-based, polyacetylene-based, and the like. Among them, for example, poly(3,4-ethylenedioxythiophene) is used in combination with polystyrenesulfonic acid, such as polythiophene-based. Is preferably used. The conductive polymer is preferable in comparison with the above-mentioned other antistatic agents in that the resistance value becomes low. However, on the other hand, it is necessary to take measures such as reducing the amount used in applications where coloration and cost are a concern.

The compound having an ammonium group is a compound having an ammonium group in the molecule, and examples thereof include ammonium compounds of aliphatic amines, alicyclic amines and aromatic amines. The compound having an ammonium group is preferably a polymer-type compound having an 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 to obtain a high molecular compound having an ammonium group is preferably used. As the polymer, a monomer containing an addition-polymerizable ammonium group or a precursor of an ammonium group such as amine may be polymerized alone, or 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 also preferable because it has excellent antistatic properties and heat resistance 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, etc. Even if these alkyl groups and phenyl groups are substituted with the groups shown below, Good. The substitutable group is, for example, a hydroxyl group, an amide group, an ester group, an alkoxy group, a phenoxy group, a naphthoxy group, a thioalkoxy, a thiophenoxy group, a cycloalkyl group, a trialkylammonium alkyl group, a cyano group, or a halogen. Further, two substituents attached to the nitrogen atom may be chemically bonded, for _{example, - (CH 2) m -} (m = 2~5 _{integer), - 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.

The 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 known solvent such as water or a polar solvent such as methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane or acetonitrile with a polymerization initiator such as hydrogen peroxide, benzoyl peroxide or tertiary butyl peroxide. However, the method is not limited thereto. A compound having a polymerizable carbon-carbon unsaturated bond with the diallylamine derivative may be used as the copolymerization component.

In addition, a polymer having a structure of the following formula (1) is also preferable in terms of excellent antistatic properties and resistance to moist heat. A single polymer or copolymer, or a plurality of other components may be copolymerized.

For example, in the above formula, the substituent R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, a hydrocarbon group such as a phenyl group, R ² is —O—, —NH— or —S—, and R ³ is other structures may establish alkylene group or structure of formula 1 having 1 to 20 carbon ^{atoms, R 4, R 5, R} 6 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group And the like, or a hydrocarbon group to which a functional group such as a hydroxyalkyl group is attached, X ⁻ is various counter ions.

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

Examples of the anion serving as a counter ion of the ammonium group of the above-mentioned compound having an ammonium group include halogen ions, sulfonates, phosphates, nitrates, alkyl sulfonates, carboxylates and the like.

The number average molecular weight of the compound having an ammonium group is 1,000 to 500,000, preferably 2,000 to 350,000, more preferably 5,000 to 200,000. If the molecular weight is less than 1000, the strength of the coating film may be weakened, or the heat stability may be poor.
When the molecular weight is more than 500000, the viscosity of the coating solution becomes high, which may deteriorate the handleability and coatability.

The compound having a sulfonic acid group is a compound containing a sulfonic acid or a sulfonic acid salt in the molecule, for example, a compound having a large amount of sulfonic acid or a sulfonic acid salt such as polystyrene sulfonic acid or a derivative thereof. It is preferably used.

As the polystyrene sulfonic acid or its derivative, a constituent having sulfonic acid or sulfonate in the para position is preferable from the viewpoint of antistatic property. Further, it may be a homopolymer or a copolymer containing other components, but from the viewpoint of antistatic property, it is better that the proportion of polystyrenesulfonic acid or its derivative is closer to that of the homopolymer, preferably 80% by weight or more. , And more preferably 90% by weight or more.

The portion of the sulfonic acid group may be in the state of sulfonic acid or in the state of sulfonic acid salt by monovalent metal ion or ammonium ion. From the viewpoint of more excellent antistatic property, the state of sulfonic acid or the state of monovalent metal salt (among them, a small metal ion such as lithium salt or sodium salt is preferable) is more preferable. Furthermore, it is preferable that the amount of sulfonic acid is larger than the amount of sulfonate, and the amount of sulfonic acid is more preferably 60% or more based on the total number of sulfonic acid and sulfonate. The range is more preferably 70% or more, and particularly preferably 80% or more. Further, from the viewpoint of coloring, it is preferable to increase the amount of sulfonate (the amount of sulfonic acid is slightly small), and in that case, the amount of sulfonic acid is preferably 99% or less, more preferably Is 97% or less, more preferably 95% or less.

The molecular weight of polystyrenesulfonic acid or its derivative is preferably in the range of 5,000 to 100,000, more preferably 10,000 to 50,000 in terms of number average molecular weight. When used in the above range, good antistatic performance and coating suitability are easily obtained.

Examples of the polyether compound include polyethylene oxide, polyether ester amide, and acrylic resin having polyethylene glycol as a side chain.

Further, in order to improve the appearance of the adhesive layer and further reduce the surface resistance value, for example, a polyalkylene oxide, glycerin, polyglycerin, glycerin or a polyol compound or polyether compound such as an alkylene oxide adduct to polyglycerin is used. It is also possible to use together.

Preferred as the polyalkylene oxide or its derivative is a structure having an ethylene oxide or propylene oxide structure. When the alkyl group in the alkylene oxide structure is too long, the hydrophobicity becomes strong, the uniform dispersibility in the coating liquid deteriorates, and the antistatic property tends to deteriorate. Particularly preferred is ethylene oxide.

Polyglycerin is a compound obtained by polymerizing two or more glycerins, and the degree of polymerization is preferably in the range of 2-20. When glycerin is used, the transparency may be slightly inferior.

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

Here, the structure of the added alkylene oxide or its derivative may be different for each hydroxyl group of the glycerin or polyglycerin structure. Further, it is sufficient that at least one hydroxyl group in the molecule is added, and it is not necessary that alkylene oxide or a derivative thereof is added to all hydroxyl groups.

Further, a structure having an ethylene oxide or propylene oxide structure is preferable as the alkylene oxide or its derivative added to glycerin or polyglycerin. If the alkyl chain in the alkylene oxide structure is too long, the hydrophobicity becomes strong, the uniform dispersibility in the coating solution deteriorates, and the antistatic property tends to deteriorate. Particularly preferred is ethylene oxide. Further, the number of additions is particularly preferably such that the final compound has a weight average molecular weight in the range of 300 to 2000.

Further, it is also preferable to use a crosslinking agent in combination from the viewpoint of the strength of the adhesive layer. Under severe conditions, depending on the resin used, the adhesive component may migrate to the adherend, but by using a crosslinking agent together, the migration of the adhesive layer to the adherend can be improved.

As the crosslinking agent, conventionally known materials can be used, and examples thereof include a melamine compound, an isocyanate compound, an epoxy compound, an oxazoline compound, a carbodiimide compound, a silane coupling compound, a hydrazide compound, and an aziridine compound. Among them, a melamine compound, an isocyanate compound, an epoxy compound, an oxazoline compound, a carbodiimide compound, a silane coupling compound is preferable, and further, the adhesive force can be appropriately maintained, and from the viewpoint of easy adjustment, a melamine compound, an isocyanate compound. The compound and the epoxy compound are more preferable, and the isocyanate compound and the epoxy compound are particularly preferable because the decrease in the adhesive strength due to the combined use can be suppressed. Further, from the viewpoint that migration to the adherend can be reduced, a melamine compound or an isocyanate compound is preferable, and among them, a melamine compound is particularly preferable. Further, a melamine compound is particularly preferable from the viewpoint of the strength of the adhesive layer. Moreover, these crosslinking agents may be used alone or in combination of two or more.

Depending on the constitution of the pressure-sensitive adhesive layer and the kind of the cross-linking agent, if the content of the cross-linking agent in the pressure-sensitive adhesive layer is too large, the pressure-sensitive adhesive property may be lowered too much. Therefore, it is necessary 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 alkylolated melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and these Mixtures can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. The melamine compound may be a monomer, a dimer or higher polymer, or a mixture thereof. Considering the reactivity with various compounds, it is preferable that the melamine compound contains a hydroxyl group. Further, a product obtained by co-condensing a part of melamine with urea or the like can be used, and a catalyst can be used to increase the reactivity of the melamine compound.

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

When used in a blocked isocyanate state, examples of the blocking agent include bisulfites, phenolic compounds such as phenol, cresol and ethylphenol, propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol and alcohols such as ethanol. Compounds, dimethyl malonate, diethyl malonate, methyl isobutanoyl acetate, methyl acetoacetate, ethyl acetoacetate, active methylene compounds such as acetylacetone, mercaptan compounds such as butyl mercaptan, dodecyl mercaptan, ε-caprolactam, δ-valerolactam, etc. Lactam compounds, diphenylaniline, aniline, amine compounds such as ethyleneimine, acetanilide, acid amide compounds of acetic acid amide, formaldehyde, acetoaldoxime, acetone oxime, methyl ethyl ketone oxime, oxime compounds such as cyclohexanone oxime, These may be used alone or in combination of two or more. Among the above, an isocyanate compound blocked with an active methylene-based compound is preferable from the viewpoint of being particularly effective in reducing the transferability of the adhesive layer to the adherend.

Further, the isocyanate compound may be used alone, or may be used as a mixture or a combined product with various polymers. From the viewpoint of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or combination of polyester resin and urethane resin.

The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include a condensate of epichlorohydrin and a hydroxyl group or an amino group such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A. 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, polytetramethylene glycol diglycidyl ether, monoepoxy compounds, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, glycidyl amine compounds N, N, N', N Examples include'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylamino)cyclohexane and the like.

Among the above, polyether-based epoxy compounds are preferable from the viewpoint of good adhesive properties. In addition, the amount of epoxy groups is preferably a polyepoxy compound that is polyfunctional, that is, trifunctional or higher than bifunctional.

The oxazoline compound is a compound having an oxazoline group in its molecule, and a polymer containing an oxazoline group is particularly preferable, and it can be prepared by addition-polymerizing an oxazoline group-containing monomer alone or with another monomer. The addition-polymerizable oxazoline group-containing monomer includes 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 kind or a mixture of two or more kinds thereof can be used. Among these, 2-isopropenyl-2-oxazoline is industrially easily available and suitable. The other monomer is not limited as long as it is a monomer copolymerizable with the addition-polymerizable oxazoline group-containing monomer, and examples thereof include alkyl (meth)acrylate (wherein the alkyl group is 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, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group Group, cyclohexyl group, etc.), unsaturated amides; vinyl acetate, vinyl propionate, and other vinyl esters; methyl vinyl ether, ethyl vinyl ether, and other vinyl ethers; ethylene, propylene, and other α-olefins; vinyl chloride, vinylidene chloride And halogen-containing α,β-unsaturated monomers such as vinyl fluoride; α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene; and one or more of these. Can be used.

The amount of the oxazoline group in the oxazoline compound is preferably in the range of 0.5 to 10 mmol/g, more preferably 1 to 9 mmol/g, further preferably 3 to 8 mmol/g, and particularly preferably 4 to 6 mmol/g. When used in the above range, the durability is improved and the adhesive property is easily adjusted.

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

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

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

The silane coupling compound is an organosilicon compound having an organic functional group and a hydrolyzing group such as an alkoxy group in one molecule. For example, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4- Epoxy group containing compounds such as epoxycyclohexyl)ethyltrimethoxysilane, vinyl group containing compounds such as vinyltrimethoxysilane, 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 and N-phenyl-3-aminopropyltriethoxysilane, tris(trimethoxysilylpropyl) Isocyanurate, isocyanurate group-containing compounds such as tris(triethoxysilylpropyl) isocyanurate, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiene Examples thereof include mercapto group-containing compounds such as ethoxysilane.

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

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

Further, from the viewpoint of the appearance of the adhesive layer, adjusting the adhesive strength, strengthening the adhesive layer, adhesiveness with the base film, blocking resistance, and preventing migration of the adhesive component to the adherend, the glass transition point is 0°C. It is also possible to jointly use a resin exceeding the above. Conventionally known materials can be used as the resin having a glass transition point of higher than 0°C. Among them, polyester resin, acrylic resin, urethane resin and polyvinyl (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.) are preferable. Considering the appearance of the adhesive layer and the influence on the adhesive force, polyester resin, acrylic resin and urethane A resin selected from resins is preferred. However, depending on the method of use, there is a concern that the adhesive strength may be significantly reduced, so caution is required.

Further, in the formation of the adhesive layer, particles can be used together for the purpose of improving blocking property, slipperiness, and adjusting adhesive property. However, care must be taken because the adhesive strength may decrease depending on the type of particles used. In order not to reduce the adhesive strength so much, the average particle size of the particles used is preferably 3 times or less, more preferably 1.5 times or less, further preferably 1.0 times or less than the film thickness of the adhesive layer. The range of 0.8 times or less is particularly preferable. In particular, when it is desired to exert 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 to impart various functions.
For example, it is also preferable to provide a release layer in order to reduce blocking of the film by the adhesive layer, and in order to prevent defects such as peeling charge of the film and adhesion of dust around the film due to frictional charging, an antistatic layer is provided. Providing is also a preferable form. The functional layer may be provided by coating, may be provided by in-line coating, or may be off-line coating. In-line coating is preferably used from the viewpoint of manufacturing cost and stabilization of releasing performance and antistatic performance due to in-line heat treatment.

For example, when a release functional layer is provided on the surface opposite to the adhesive layer of the film, the release agent contained in the functional layer is not particularly limited, and a conventionally known release agent can be used. There are, for example, long chain alkyl group-containing compounds, fluorine compounds, silicone compounds, waxes and the like. Of these, long-chain alkyl compounds and fluorine compounds are preferable from the viewpoints of low contamination and excellent blocking reduction, and silicone compounds are preferable when it is particularly important to reduce blocking. In addition, wax is effective for improving the surface contamination removal property. These release agents may be used alone or in combination of two or more.

The long-chain alkyl group-containing compound is a compound having a linear or branched alkyl group having usually 6 or more, preferably 8 or more, and more preferably 12 or more carbon atoms. Examples of the alkyl group include a hexyl group, an octyl group, a decyl group, a lauryl group, an octadecyl group, and a behenyl group. Examples of the compound having an alkyl group include various long-chain alkyl group-containing polymer compounds, long-chain alkyl group-containing amine compounds, long-chain alkyl group-containing ether compounds, and long-chain alkyl group-containing quaternary ammonium salts. .. A polymer compound is preferable in consideration of heat resistance and stain resistance. Further, from the viewpoint of effectively obtaining releasability, a polymer compound having a long chain alkyl group in its side chain is more preferable.

The polymer compound having a long chain alkyl group in its side chain can be obtained by reacting a polymer having a reactive group with a compound having an alkyl group capable of reacting with the reactive group. Examples of the reactive group include a hydroxyl group, an amino group, a carboxyl group, an acid anhydride and the like.
Examples of the compound having these reactive groups include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resin, reactive group-containing poly(meth)acrylic resin, and the like. Of these, polyvinyl alcohol is preferable in view of releasability and ease of handling.

The compound having an alkyl group capable of reacting with the reactive group, for example, hexyl isocyanate, octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, long-chain alkyl group-containing isocyanate such as behenyl isocyanate, hexyl chloride, octyl chloride. , Long-chain alkyl group-containing acid chlorides such as decyl chloride, lauryl chloride, octadecyl chloride and behenyl chloride, long-chain alkyl group-containing amines, and long-chain alkyl group-containing alcohols. Of these, long-chain alkyl group-containing isocyanates are preferable, and octadecyl isocyanate is particularly preferable, in consideration of releasability and ease of handling.

Further, the polymer compound having a long-chain alkyl group in the side chain can also be obtained by polymerizing a long-chain alkyl (meth)acrylate or copolymerizing a long-chain alkyl (meth)acrylate with another vinyl group-containing monomer. .. Examples of the long-chain alkyl (meth)acrylate include hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, and behenyl (meth)acrylate. To be

The fluorine compound is a compound containing a fluorine atom in the compound. Organic fluorine compounds are preferably used in terms of the appearance of coating by in-line coating, and examples thereof include perfluoroalkyl group-containing compounds, polymers of fluorine atom-containing olefin compounds, and aromatic fluorine compounds such as fluorobenzene. .. From the viewpoint of releasability, a compound having a perfluoroalkyl group is preferable. Further, as the fluorine compound, a compound containing a long chain alkyl compound as described below can also be used.

The compound having a perfluoroalkyl group is, for example, perfluoroalkyl(meth)acrylate, perfluoroalkylmethyl(meth)acrylate, 2-perfluoroalkylethyl(meth)acrylate, 3-perfluoroalkylpropyl(meth)acrylate. , 3-perfluoroalkyl-1-methylpropyl (meth)acrylate, 3-perfluoroalkyl-2-propenyl (meth)acrylate and other perfluoroalkyl group-containing (meth)acrylates and polymers thereof, perfluoroalkylmethyl vinyl ether , 2-perfluoroalkylethyl vinyl ether, 3-perfluoropropyl vinyl ether, 3-perfluoroalkyl-1-methylpropyl vinyl ether, 3-perfluoroalkyl-2-propenyl vinyl ether, and other perfluoroalkyl group-containing vinyl ethers and polymers thereof. And so on. A polymer is preferable in consideration of heat resistance and stain resistance. The polymer may be a single compound or a polymer of a plurality of compounds. From the viewpoint of releasability, the perfluoroalkyl group preferably has 3 to 11 carbon atoms. Further, it may be a polymer with a compound containing a long-chain alkyl compound as described below. From the viewpoint of adhesion to the substrate, it is also preferably a polymer with vinyl chloride.

The silicone compound is a compound having a silicone structure in the molecule, and examples thereof include alkyl silicones such as dimethyl silicone and diethyl silicone, and phenyl silicone having a phenyl group, methylphenyl silicone and the like. As the silicone, those having various functional groups can be used, and examples thereof include ether groups, hydroxyl groups, amino groups, epoxy groups, carboxylic acid groups, halogen groups such as fluorine, perfluoroalkyl groups, various alkyl groups and various types. Examples thereof include hydrocarbon groups such as aromatic groups. As other functional groups, silicones having vinyl groups and hydrogen silicones in which hydrogen atoms are directly bonded to silicon atoms are also common, and by using both together, addition type (type by addition reaction of vinyl group and hydrogen silane) silicone It is also possible to use as.

Further, as the silicone compound, it is also possible to use modified silicone such as acrylic graft silicone, silicone graft acrylic, amino modified silicone, perfluoroalkyl modified silicone. In consideration of heat resistance and stain resistance, it is preferable to use a curable silicone resin, and the curable type may be any of a condensation reaction type, an addition type, an active energy ray curable type and the like. Among these, the condensation type silicone compound is preferable from the viewpoint that there is little back surface transfer when it is rolled.

As a preferred form of using a silicone compound, a polyether group-containing silicone compound is preferred from the viewpoints of low backside transfer, good dispersibility in an aqueous solvent, and high suitability for in-line coating. The polyether group may be present on the side chain or terminal of the silicone or on the main chain. From the viewpoint of dispersibility in an aqueous solvent, it is preferable to have a side chain or a terminal.

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

The number of ether bonds of the polyether group is usually in the range of 1 to 30, preferably 2 to 20, and more preferably 3 to, from the viewpoint of improving dispersibility in an aqueous solvent and durability of the functional layer. There are 15 ranges. If there are few ether bonds, the dispersibility deteriorates, and conversely, if there are too many ether bonds, the durability and release performance deteriorate.

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

The content of the polyether group in the polyether group-containing silicone is preferably in the range of 0.001 to 0.30%, more preferably 0.01 to 0. It is in the range of 20%, more preferably in the range of 0.03 to 0.15%, particularly preferably in the range of 0.05 to 0.12%. By using within this range, the dispersibility in water, the durability of the functional layer and the good releasability can be maintained.

The molecular weight of the polyether group-containing silicone is preferably not so large in consideration of dispersibility in an aqueous solvent, and is preferably large in consideration of durability and release performance of the functional layer. It is required to balance the properties of the both, and the number average molecular weight is preferably in the range of 1,000 to 100,000, more preferably in the range of 3,000 to 30,000, and further preferably in the range of 5,000 to 10,000.

Further, in consideration of aging of the functional layer, release performance, and contamination in various processes, it is preferable that the low-molecular component of silicone (500 or less in number average molecular weight) is as small as possible. The total ratio is preferably 15% by weight or less, more preferably 10% by weight or less, and further preferably 5% by weight or less. When a condensation type silicone is used, the silicon-bonded vinyl group (vinyl silane) and hydrogen group (hydrogen silane) may cause various performance deterioration with time if they remain unreacted in the functional layer. The content of the functional group therein is preferably 0.1 mol% or less, more preferably not contained.

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

As the anionic dispersant, sodium dodecylbenzenesulfonate, sodium alkylsulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate, polyoxyalkylene alkenyl alkenyl Sulfonates such as ammonium ammonium sulfate and sulfates, sulfates such as sodium laurate and potassium oleate, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates Examples thereof include phosphate-based salts such as salts. Among these, the sulfonate type is preferable from the viewpoint of good dispersibility.

As the nonionic dispersant, for example, an ether type obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to a compound having a hydroxyl group such as a higher alcohol or an alkylphenol, a polyhydric alcohol such as glycerin or a saccharide, and a fatty acid are ester-bonded. Examples thereof include an ester type, an ester/ether type obtained by adding an alkylene oxide to a fatty acid or a polyhydric alcohol fatty acid ester, and an amide type in which a hydrophobic group and a hydrophilic group have an amide bond. Among these, the ether type is preferable in consideration of solubility and stability in water, and the type added with ethylene oxide is more preferable in consideration of handleability.

It cannot be said unequivocally because it depends on the molecular weight and structure of the polyether group-containing silicone used, and also on the type of dispersant used. The weight ratio is preferably 0.01 to 0.5, more preferably 0.05 to 0.4, and further preferably 0.1 to 0.3.

The wax is a wax selected from natural wax, synthetic wax, and waxes containing them. The natural wax is a vegetable wax, an animal wax, a mineral wax, or a petroleum wax. Examples of vegetable waxes include candelilla wax, carnauba wax, rice wax, wax and jojoba oil. Animal waxes include beeswax, lanolin, whale wax and the like. Examples of mineral waxes include montan wax, ozokerite, and ceresin. Examples of the petroleum wax include paraffin wax, microcrystalline wax, petrolatum and the like. Examples of synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, esters and ketones. Examples of synthetic hydrocarbons include Fischer-Tropsch wax (also known as Sazol wax) and polyethylene wax, and other low molecular weight polymers (specifically, polymers having a number average molecular weight of 500 to 20,000). The following polymers are also included, that is, polypropylene, ethylene/acrylic acid copolymer, polyethylene glycol, polypropylene glycol, a block or graft conjugate of polyethylene glycol and polypropylene glycol, and the like. Examples of the modified wax include montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives. The derivative here is a compound obtained by any treatment of purification, oxidation, esterification, saponification, or a combination thereof. Hydrogenated waxes include hydrogenated castor oil and hydrogenated castor oil derivatives.

Of the above, synthetic waxes are preferable, polyethylene waxes are more preferable, and oxidized polyethylene waxes are still more preferable, from the viewpoint of stable properties. The number average molecular weight of the synthetic wax is preferably 500 to 30,000, more preferably 1,000 to 15,000, and further preferably 2,000 to 8,000, from the viewpoint of stability of properties such as blocking and handleability.

When an antistatic functional layer is provided on the surface opposite to the adhesive layer of the film, the antistatic agent contained in the functional layer is not particularly limited, and a conventionally known antistatic agent can be used. A polymer type antistatic agent is preferred because it has good heat resistance and wet heat resistance. Specifically, the same antistatic agent as that for the adhesive layer can be used.

It is also a preferable mode that the functional layer which can be provided on the surface of the film opposite to the pressure-sensitive adhesive layer contains both the above-mentioned releasing agent and antistatic agent and has an antistatic releasing function.

In order to form the functional layer, various polymers such as polyester resin, acrylic resin, urethane resin and the like, and a crosslinking agent that can be used for forming the adhesive layer are used together in order to improve the coating appearance, transparency, and control of slipperiness. It is also possible. Particularly, from the viewpoint of strengthening the functional layer and reducing blocking, it is preferable to use a melamine compound, an oxazoline compound, an isocyanate compound, an epoxy compound, and a carbodiimide compound in combination, and among them, a melamine compound is particularly preferable.

Particles can be used together with the functional layer for the purpose of blocking and improving slipperiness, as long as the gist of the present invention is not impaired. However, when the functional layer has a releasing property, it often has sufficient blocking resistance and slipperiness, and therefore it may be preferable not to use particles in combination from the viewpoint of the appearance of the functional layer.

Furthermore, in the range that does not impair the gist of the present invention, an antifoaming agent, a coatability improving agent, a thickening agent, an organic lubricant, an antistatic agent, an ultraviolet absorber, if necessary, for forming the adhesive layer and the functional layer, It is also possible to use an antioxidant, a foaming agent, a dye, a pigment and the like in combination.

As a proportion of the adhesive layer constituting the laminated polyester film, a resin having a glass transition point of 0° C. or lower is usually 10 to 99.9% by weight, preferably 30 to 9% when the antistatic agent used in combination is a conductive polymer. The range is 99.8% by weight, more preferably 50 to 98% by weight, further preferably 65 to 97% by weight, and particularly preferably 75 to 94% by weight. When the antistatic agent used in combination is other than the conductive polymer, it is usually in the range of 10 to 90% by weight, preferably 30 to 85% by weight, more preferably 50 to 80% by weight. If the content is too small, the adhesive properties will not be sufficient, and conversely if it is too large, the antistatic performance will be insufficient due to the small amount of antistatic agent, and dust adhesion will be a problem. May be

As a ratio in the adhesive layer constituting the laminated polyester film, the antistatic agent is usually 0.1 to 80% by weight, preferably 0.2 to 50% by weight, more preferably 0.5 in the case of a conductive polymer. -30% by weight, more preferably 1.0-20% by weight, particularly preferably 1.5-8% by weight. When the antistatic agent is other than the conductive polymer, it is usually in the range of 5 to 90% by weight, preferably 10 to 70% by weight, more preferably 15 to 50% by weight.
If the content of the antistatic agent is too small, the antistatic performance becomes insufficient, and the adhesion of dust becomes a problem. On the contrary, if the content is too large, the amount of resin having a glass transition point of 0° C. or less is small, Adhesive properties may be inadequate.

In the laminated polyester film, when a functional layer having a releasing property is provided on the side opposite to the pressure-sensitive adhesive layer, the proportion of the releasing agent as a proportion in the functional layer is uncertain because an appropriate amount varies depending on the type of the releasing agent. Although it cannot be said, the range is preferably 3% by weight or more, more preferably 15% by weight or more, and further preferably 25 to 99% by weight. If it is less than 3% by weight, the blocking reduction may not be sufficient.

When a long-chain alkyl compound or a fluorine compound is used as a release agent, the proportion in the functional layer is preferably 5% by weight or more, more preferably 15 to 99% by weight, further preferably 20 to 95% by weight, and particularly It is preferably in the range of 25 to 90% by weight. When used in the above range, blocking reduction becomes effective. The proportion of the crosslinking agent is preferably 95% by weight or less, more preferably 1 to 80% by weight, further preferably 5 to 70% by weight, and particularly preferably 10 to 50% by weight. A compound or an isocyanate compound (among them, a blocked isocyanate blocked with an active methylene compound is particularly preferable), and a melamine compound is particularly preferable from the viewpoint of reducing blocking.

When a condensation type silicone compound is used as a release agent, the proportion in the functional layer is preferably 3% by weight or more, more preferably 5 to 97% by weight, further preferably 8 to 95% by weight, particularly preferably It is in the range of 10 to 90% by weight. When used in the above range, blocking reduction becomes effective. The proportion of the crosslinking agent is preferably 97% by weight or less, more preferably 3 to 95% by weight, further preferably 5 to 92% by weight, and particularly preferably 10 to 90% by weight. Further, as the crosslinking agent, a melamine compound is preferable from the viewpoint of reducing blocking.

When an addition type silicone compound is used as a release agent, the proportion in the functional layer is preferably 5% by weight or more, more preferably 25% by weight or more, further preferably 50% by weight or more, particularly preferably 70% by weight. % Or more. The upper limit of the preferable range is 99% by weight, and the more preferable upper limit is 90% by weight. When used in the above range, blocking is effectively reduced and the functional layer has a good appearance.

When wax is used as the release agent, the proportion in the functional layer is preferably 10% by weight or more, more preferably 20 to 90% by weight, and further preferably 25 to 70% by weight. By using in the above range, blocking can be easily reduced. However, when a wax is used for the purpose of decontaminating the surface, the above-mentioned proportion can be reduced, preferably 1% by weight or more, more preferably 2 to 50% by weight, further preferably 3 to 30% by weight. % Range. The proportion of the cross-linking agent is preferably 90% by weight or less, more preferably 10 to 70% by weight, still more preferably 20 to 50% by weight. Further, as the crosslinking agent, a melamine compound is preferable from the viewpoint of reducing blocking.

On the other hand, when a functional layer having antistatic performance is provided on the side opposite to the adhesive layer, the proportion of the antistatic agent as the proportion in the functional layer cannot be unequivocally determined because an appropriate amount varies depending on the type of antistatic agent. Is preferably 0.5% by weight or more, more preferably 3 to 90% by weight, further preferably 5 to 70% by weight, particularly preferably 8 to 60% by weight. If it is less than 0.5% by weight, the antistatic effect is not sufficient, and the effect of preventing adhesion of dust and the like in the surroundings may be insufficient.

When an antistatic agent other than the conductive polymer is used as the antistatic agent, the proportion in the antistatic layer is preferably 5% by weight or more, more preferably 10 to 90% by weight, and further preferably 20 to 70% by weight. The range, particularly preferably the range of 25 to 60% by weight. If it is less than 5% by weight, the antistatic effect is not sufficient, and the effect of preventing adhesion of dust and the like in the surroundings may be insufficient.

When a conductive polymer is used as the antistatic agent, the proportion in the antistatic layer is preferably 0.5% by weight or more, more preferably 3 to 70% by weight, further preferably 5 to 50% by weight, particularly preferably It is in the range of 8 to 30% by weight. If it is less than 0.5% by weight, the antistatic effect is not sufficient, and the effect of preventing adhesion of dust and the like in the surroundings may be insufficient.

The components in the adhesive layer or the functional layer can be analyzed by TOF-SIMS, ESCA, fluorescent X-ray, IR, etc., for example.

Regarding the formation of the adhesive layer or the functional layer, the above-mentioned series of compounds is used as a dispersion of a solution or a solvent, and a liquid whose solid content concentration is adjusted to about 0.1 to 80% by weight is coated on the film. It is preferred to produce a laminated polyester film. Particularly when it is provided by in-line coating, an aqueous solution or an aqueous dispersion is more preferable. The coating liquid may contain a small amount of an organic solvent for the purpose of improving dispersibility in water, improving film-forming property, and the like. Further, the organic solvent may be only one kind, or may be appropriately used two or more kinds.

It is essential that the film thickness of the adhesive layer is 10 μm or less, preferably 1 nm to 4 μm, more preferably 10 nm to 1 μm, further preferably 20 to 700 nm, particularly preferably 30 to 600 nm, most preferably 50 to 480 nm. The range is. By using the film thickness of the adhesive layer in the above range, it becomes easy to maintain appropriate adhesive properties, antistatic properties and blocking properties.

A general adhesive layer has a thick film thickness of more than 10 μm. In such a case, for example, when it is used for manufacturing a polarizing plate, the adhesive film is not covered with a polarizing plate, a retardation plate or a viewing angle widening plate. In some cases, such as when the sheet is attached to the adherend and cut, the adhesive in the adhesive layer may significantly protrude. However, the protrusion can be minimized by adjusting the film thickness within the above range. This effect becomes better as the thickness of the adhesive layer is smaller. Further, as the film thickness of the pressure-sensitive adhesive layer is smaller, the absolute amount of the pressure-sensitive adhesive layer present on the film may be smaller, which is also effective in reducing the adhesive residue, which is the transfer of the components of the pressure-sensitive adhesive layer to the adherend. Further, by setting the film thickness in the above range, it is also found that it is possible to achieve an appropriate adhesive strength that is not too strong, for example, for polarizing plate manufacturing process, and the like, compatibility of the adhesive performance and the peeling performance of peeling after bonding. When it is used for an application that needs to be achieved, the operation of laminating-peeling can be easily performed, and an optimal film can be obtained. The thinner the film thickness, the more effective the blocking property is, which is preferable because it is easy to manufacture when the adhesive layer is formed by in-line coating, but if the film thickness is too thin, the adhesive property may be different depending on the structure of the adhesive layer. Since it may be lost, it is preferable to use it in the above-mentioned suitable range depending on the application.

The film thickness of the functional layer depends on the function to be provided, and therefore cannot be generally stated. For example, the functional layer for imparting mold release performance and antistatic performance is preferably 1 nm to 3 μm, and more preferably The range is 10 nm to 1 μm, more preferably 20 to 500 nm, and particularly preferably 20 to 200 nm. By using the film thickness of the functional layer within the above range, it is easy to improve the blocking characteristics, the antistatic performance, and the good appearance.

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

Drying and curing conditions for forming the adhesive layer on the film are not particularly limited, but in the case of a method by coating, drying of a solvent such as water used in the coating liquid is preferably 70. To 150°C, more preferably 80 to 130°C, still more preferably 90 to 120°C. As a guide, the drying time is in the range of 3 to 200 seconds, preferably 5 to 120 seconds. In addition, in order to improve the strength of the adhesive layer, a heat treatment step in the range of preferably 180 to 270°C, more preferably 200 to 250°C, and further preferably 210 to 240°C is performed in the film production process. As a guide, the time of the heat treatment step is 3 to 200 seconds, preferably 5 to 120 seconds.

Moreover, you may use heat treatment and irradiation of active energy rays, 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 and plasma treatment in advance.

As the adhesive force of the adhesive layer, the adhesive force to the polymethylmethacrylate plate measured by the measuring method described later is preferably 1 to 5000 mN/cm, more preferably 3 to 3000 mN/cm, and further preferably 5 ˜500 mN/cm, particularly preferably 7 to 300 mN/cm, most preferably 10 to 100 mN/cm. When the content is in the above range, both the adhesive performance and the peeling performance of peeling after bonding can be achieved at the same time, and it becomes possible to obtain an optimum laminate for various steps of performing the operation of adhesive-peeling. .. In addition, the blocking property of the film tends to be good.

As the blocking property of the laminated polyester film, the side face of the adhesive layer of the laminated polyester film and the opposite side face (the side face of the functional layer when there is a functional layer) are superposed, and 40° C., 80% RH, 10 kg/cm ² , for 20 hours. The peeling load after pressing under the conditions is preferably 100 g/cm or less, more preferably 30 g/cm or less, further preferably 20 g/cm or less, particularly preferably 10 g/cm or less, and most preferably 8 g/cm or less. It is a range. By setting it as the said range, it becomes easy to avoid the risk of blocking and it can be set as a more highly practical film.

As the antistatic performance of the adhesive layer, the surface resistance value is preferably in the range of 1×10 ¹² Ω or less, more preferably 1×10 ¹¹ Ω or less, and further preferably 5×10 ¹⁰ Ω or less. Within the above range, the film will have less adhesion of dust and the like.

In addition, in applications requiring antistatic properties also on the functional layer side, the surface resistance value of the functional layer is preferably 1×10 ¹² Ω or less, more preferably 1×10 ¹¹ Ω or less, and further preferably 5×. It is in the range of 10 ¹⁰ Ω or less. Within the above range, the film has less adhesion of dust and the like.

Further, roughening the film surface on the side opposite to the adhesive layer (the side of the functional layer when there is a functional layer) may be one of the means for improving the blocking property with the adhesive layer side. .. It cannot be said unequivocally because it depends on the type and adhesive strength of the adhesive layer, but if the purpose is to improve the blocking property by surface roughness regardless of the functional layer, the film surface on the side opposite to the adhesive layer The arithmetic mean roughness (Sa) is preferably in the range of 5 nm or more, more preferably 8 nm or more, further preferably 30 nm or more, and the upper limit is not particularly limited, but is 300 nm from the viewpoint of transparency as the upper limit of the preferred range. Is. When the releasability is good by a method such as providing a release functional layer on the side opposite to the adhesive layer, the releasability becomes dominant, so that the influence of Sa is small and no special attention is required. However, when the releasability is weak, the influence of Sa may be large, which can be an effective means for improving the blocking characteristics. However, since increasing haze increases haze and lowers transparency, it is necessary to take measures depending on the intended use, and it is preferable to consider blocking improvement by the release layer in a case where transparency is particularly important. ..

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. The measuring method and the evaluating method used in the present invention are as follows.

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

(2) Method of measuring average particle diameter (d50: μm) Shimadzu Corporation, centrifugal sedimentation type particle size distribution measuring device SA-CP3 type equivalent spherical distribution measured by using SA-CP3 value (value by weight) of 50% Was defined as the average particle size.

(3) Method of Measuring Arithmetic Average Roughness (Sa) The film surface was measured using a non-contact surface/layer cross-section shape measuring system VertScan (registered trademark) R550GML manufactured by Ryoka Systems Inc., and a CCD camera: Sony HR- 50 1/3′, objective lens: 20 times, lens barrel: 1X Body, zoom lens: No Relay, wavelength filter: 530 white, measurement mode: Wave, and output was obtained by fourth-order polynomial correction.

(4) Method of 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. After that, the section prepared by the ultrathin section method was stained with RuO ₄ , and the cross section of the adhesive layer was measured using TEM (H-7650 manufactured by Hitachi High-Technologies Corporation, accelerating voltage 100 kV).

(5) Glass transition point PerkinElmer Japan Co., Ltd. make, differential scanning calorimeter (DSC) 8500 was used, and it measured at the temperature rising conditions of -100-200 degreeC per minute 10 degreeC.

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

(7-1) Adhesive strength evaluation method (adhesive strength 1)
On the surface of a polymethylmethacrylate plate (Komoray Co., Ltd., Kuraray Co., Ltd., thickness 1 mm), the pressure-sensitive adhesive layer surface of the laminated polyester film of the present invention having a width of 5 cm was crimped back and forth with a 2 kg rubber roller having a width of 5 cm at room temperature. The peeling force after standing for 1 hour was measured. As the peeling force, “Ezgraph” manufactured by Shimadzu Corporation was used, and 180° peeling was performed under the condition of a pulling speed of 300 mm/min.

(7-2) Adhesive strength evaluation method (adhesive strength 2)
(7-1) In place of the polymethylmethacrylate plate of (7-1), the adhesive force was evaluated using the polyester film surface (thickness: 25 μm) without the adhesive layer obtained in Comparative Example 1 described later (7-1 ) And evaluated.

(8) Evaluation method of adhesive property The adhesive property was evaluated by stacking one A4 size laminated polyester film on the adhesive layer side and pressing it with a finger. 5 points when the film sticks and can be held in a curled state by simply pressing lightly with a finger, 4 points when the film can be held in a curled state by pressing it strongly with a finger, and a film when pressed firmly with a finger Can be held in a rolled state, but it can be peeled off within 3 seconds. 3 points, and if the film is strongly pressed with a finger, the adhesive property is minute but the rolled state cannot be held at all. The point was 1 when no adhesive property was observed even when pressed strongly with a finger. In practical use, 3 or more points are preferable.

(9) Method of measuring surface resistance The surface resistance of the adhesive layer was measured based on the method of (9-1) below. Since the surface resistivity lower than 1×10 ⁸ Ω cannot be sufficiently measured by the method (9-1), the method (9-2) was used for the film that could not be measured by the method (9-1).
In addition, when surface resistance exceeds 1*10< ¹⁴ >(ohm), it described as "-".

(9-1) Using a high resistance measuring instrument: HP4339B and measuring electrode: HP16008B manufactured by Nippon Hewlett-Packard Co., Ltd., a polyester film was sufficiently conditioned under a measurement atmosphere of 23° C. and 50% RH, and then with an applied voltage of 100V. The surface resistance of the coating layer after 1 minute was measured.
(9-2) Mitsubishi Chemical Co., Ltd. low resistance meter: Loresta GP MCP-T600 was used, and the surface resistance of the coating layer was measured after controlling the humidity of the sample for 30 minutes in a measurement atmosphere of 23° C. and 50% RH.

(10) Evaluation method of dust adhesion on functional layer (antistatic layer) side After sufficiently controlling the humidity of the polyester film in a measurement atmosphere of 23° C. and 50% RH, the antistatic layer is rubbed 10 times with a cotton cloth. This was gently brought close to the finely crushed cigarette ash, and the ash adhesion state was evaluated according to the following criteria.
A: Does not adhere even when the film is in contact with ash B: Very slightly adheres when the film is contacted with ash C: A little adheres when the film is contacted with ash D: A large amount just by bringing the film close to ash Adhere to

(11) Blocking property measuring method Two polyester films to be measured are prepared, and the adhesive layer side and the side opposite to the adhesive layer (the functional layer side when there is a functional layer) are overlapped, and the area is 12 cm×10 cm. Was pressed under the conditions of 40° C., 80% RH, 10 kg/cm ² , and 20 hours. After that, the films were peeled from each other according to the method specified in ASTM D1893, and the peeling load was measured.
In addition, when it was not possible to perform a sufficient measurement in excess of 300 g/cm or when the film was broken, it was described as "-".

(12) Evaluation Method of Adhesive Layer Adhesive Residue (Transfer Characteristics) A pressure sensitive adhesive layer side of one sheet of A4 size laminated polyester film and an A4 size polyester film having no pressure sensitive adhesive layer of Comparative Example 1 described later are overlaid with fingers. After strongly pressing and pasting, the film having the adhesive layer was peeled off, and the film surface without the adhesive layer of Comparative Example 1 was observed. A when there was no adhesive residue (transferring trace of the adhesive layer), strongly with the finger The case where there is adhesive residue (slightly trace of transfer of the adhesive layer) in a range of 20% or less of the pressed portion is B, and the case where there is adhesive residue in a range of more than 20% of the strongly pressed portion is C. ..

The polyesters used in Examples , Reference Examples and Comparative Examples were 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 produced polyester, magnesium acetate tetrahydrate as a catalyst with 100 ppm of the ester at 260° C. in a nitrogen atmosphere at 260° C. The chemical reaction was carried out. Subsequently, 50 ppm of tetrabutyl titanate was added to the produced polyester, the temperature was raised to 280° C. over 2 hours and 30 minutes, the absolute pressure was reduced to 0.3 kPa, and melt polycondensation was continued for 80 minutes to obtain an intrinsic viscosity. A polyester (A) having 0.63 and an amount of diethylene glycol of 2 mol% was obtained.

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

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

<Production method of polyester (D)>
A polyester (D) is produced in the same manner as in the method for producing the polyester (A) except that 0.6 part by weight of silica particles having an average particle size of 3.2 μm is added before the melt polymerization. Got

Examples of compounds constituting the adhesive layer and the functional layer are as follows.
(Compound example)
・Polyester resin: (IA)
Aqueous dispersion of polyester resin (glass transition point: -20°C) consisting of the following composition Monomer composition: (acid component) dodecanedicarboxylic acid/terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene Glycol/1,4-butanediol=20/38/38/4//40/60 (mol%)

・(Meth)acrylic resin: (IB)
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)
・(Meth)acrylic resin: (IC)
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 (wt%)

-Antistatic agent (conductive polymer): (IIA) Poly(3,4-ethylenedioxythiophene) in combination with polystyrene sulfonic acid

・Antistatic agent (quaternary ammonium salt compound): (IIB)
Polymer having a pyrrolidinium ring in the main chain and polymerized with the following composition: diallyldimethylammonium chloride/dimethylacrylamide/N-methylolacrylamide=90/5/5 (mol%). Number average molecular weight 30,000.

・Antistatic agent (compound having ammonium group): (IIC)
A polymer compound having a number average molecular weight of 50,000, whose counter ion is a methanesulfonate ion, which is composed of a structural unit represented by the following formula (2).

・Antistatic agent (compound having sulfonic acid group): (IID)
A homopolymer of styrene sulfonic acid and a salt thereof having a sulfonic acid and a sulfonate group in the para position, wherein the ratio of the sulfonic acid and the sulfonate in the polymer is 90% sulfonic acid and 10% sodium sulfonate. A polymer compound having a number average molecular weight of 20,000.

・Melamine compound: (IIIA) hexamethoxymethylol melamine

Epoxy compound: (IIIB) polyfunctional polyepoxy compound, polyglycerol polyglycidyl ether

・Polyether compound: (IV)
Polyethylene oxide adduct to diglycerin structure. Weight average molecular weight 350.

・Release agent (compound containing long-chain alkyl group): (VA)
To a four-necked flask, 200 parts of xylene and 600 parts of octadecyl isocyanate were added and heated with stirring. From the time when xylene started to reflux, 100 parts of polyvinyl alcohol having an average polymerization degree of 500 and a saponification degree of 88 mol% was added little by little at intervals of 10 minutes for about 2 hours. After the addition of polyvinyl alcohol was completed, the mixture was refluxed for another 2 hours to complete the reaction. When the reaction mixture was cooled to about 80° C. and then added to methanol, a reaction product was precipitated as a white precipitate. This precipitate was filtered off, 140 parts of xylene was added, and the mixture was heated to completely dissolve it. After that, the operation of adding methanol again to cause precipitation was repeated several times, and then the precipitate was washed with methanol and dried and pulverized.

・Release agent (fluorine compound): (VB)
Aqueous dispersion of fluorine compound having the following composition Octadecyl acrylate/Perfluorohexyl ethyl methacrylate/Vinyl chloride=66/17/17 (wt%)

-Polyether group-containing condensed silicone: (VC)
Polyether group-containing silicone having a number average molecular weight of 7,000 (silicone siloxane) containing 1 side chain of dimethyl silicone and 1 polyethylene glycol (terminal is a hydroxyl group) having 8 ethylene glycol chains per 100 moles of dimethyl siloxane. When the number of bonds is 1, the ether bond of the polyether group is 0.07 in a molar ratio. 3% of low molecular weight components having a number average molecular weight of 500 or less, no silicon-bonded vinyl group (vinylsilane) and hydrogen group (hydrogensilane). In addition, this compound was obtained by blending sodium dodecylbenzene sulfonate at a ratio of 0.25 with a polyether group-containing silicone as 1 and dispersing in water.

・Wax: (VD)
In an emulsification equipment with an internal capacity of 1.5 L equipped with a stirrer, a thermometer, and a temperature controller, a melting point of 105° C., an acid value of 16 mg KOH/g, a density of 0.93 g/mL, 300 g of a polyethylene oxide wax having a number average molecular weight of 5000, and 650 g of ion-exchanged water. 50 g of decaglycerin monooleate surfactant and 10 g of 48% potassium hydroxide aqueous solution were added, and after replacing with nitrogen, the mixture was sealed, stirred at 150° C. for 1 hour at high speed and cooled to 130° C., and a high-pressure homogenizer under 400 atm. A wax emulsion that was passed and cooled to 40°C.

・Polyester resin: (VIA)
Aqueous 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%)

・(Meth)acrylic resin: (VIB)
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)
・(Meth)acrylic resin: (VIC)
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 (wt %)

Example 1:
A mixed raw material obtained by mixing polyesters (A), (B), and (C) at a ratio of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and each of the polyesters (A) and (B) was 97%. %, 3% as a raw material for the intermediate layer, each of which is supplied to two extruders, melted at 285° C., and then melted at 2° C. on a cooling roll set at 40° C. An unstretched sheet was obtained by coextrusion and cooling and solidification in a layer structure of layers (surface layer/intermediate layer/surface layer=discharge amount of 3:19:3).
Then, the film was stretched 3.3 times in the machine direction at a film temperature of 85° C. using the roll peripheral speed difference, and then the coating solution A1 shown in Table 1 below was applied to one side of the machine direction stretched film to obtain a film thickness of the adhesive layer (dry). The coating solution B1 shown in Table 2 below is applied so that the thickness (after drying) of the functional layer is 30 nm, and the solution is introduced into a tenter and heated at 90°C. After drying for 10 seconds, it was stretched 4.3 times in the transverse direction at 110° C., heat-treated at 230° C. for 10 seconds, and then relaxed by 2% in the transverse direction, the thickness was 25 μm, the back surface side of the adhesive layer (function). A polyester film having a surface (layer side) Sa of 9 nm was obtained.

When the polyester film thus prepared was evaluated, the adhesive force with the polymethylmethacrylate plate was 6 mN/cm, adhesive properties were observed, and the surface resistance was 2×10 ⁹ Ω, which was a good antistatic property. The characteristics of this film are shown in Table 3 below.

Examples 2-77:
A polyester film was obtained in the same manner as in Example 1 except that the coating agent composition shown in Tables 1 and 2 was changed. The resulting polyester film had good adhesive strength and surface resistance as shown in Tables 3 to 7 below.

Example 78:
Polyesters (A), (B), and (C) were mixed at a ratio of 91%, 3%, and 6%, respectively, and a mixed raw material was used as a raw material for the outermost layer (surface layer 1), and polyesters (A), (B), ( The mixed raw materials obtained by mixing D) at 72%, 3%, and 25% were used as raw materials for the outermost layer (surface layer 2), and polyesters (A) and (B) were mixed at 97% and 3%, respectively. Using the mixed raw material as the raw material for the intermediate layer, each was supplied to two extruders and melted at 285° C. respectively, and then three types of three layers (surface layer 1/intermediate layer/surface layer) were placed on a cooling roll set to 40° C. An unstretched sheet was obtained by coextrusion and cooling and solidifying in a layer structure of 2=6:13:6 discharge amount). Then, the film was stretched 3.3 times in the longitudinal direction at a film temperature of 85° C. by utilizing the difference in roll peripheral speed, and then the coating solution A1 shown in Table 1 below was applied to the surface layer 1 side of the longitudinally stretched film. After coating (after drying) to be 250 nm, it is introduced into a tenter, dried at 90° C. for 10 seconds, then stretched in the transverse direction by 4.3 times at 110° C., and heat-treated at 230° C. for 10 seconds. A polyester film having a thickness of 25 μm and a Sa of 30 nm on the back surface side (surface layer 2 side, functional layer side) of the adhesive layer was obtained.

The polyester film thus produced was evaluated and found to have an adhesive force with a polymethylmethacrylate plate of 10 mN/cm, good adhesive properties, and a surface resistance of 1×10 ⁹ Ω, which was a good antistatic property. The characteristics of this film are shown in Table 7 below.

Examples 79-84:
A polyester film was obtained in the same manner as in Example 78 except that the coating composition was changed to the coating composition shown in Table 1. As shown in Table 7 below, the resulting polyester film had good adhesive strength and surface resistance.

Example 85:
Polyesters (A), (B), and (C) were mixed at a ratio of 91%, 3%, and 6%, respectively, and a mixed raw material was used as a raw material for the outermost layer (surface layer 1), and polyesters (A), (B), ( D) was mixed in the proportions of 47%, 3% and 50%, respectively, and the raw materials for the outermost layer (surface layer 2) were used, and polyesters (A) and (B) were mixed in the proportions of 97% and 3%, respectively. Using the mixed raw material as the raw material for the intermediate layer, each was supplied to two extruders and melted at 285° C. respectively, and then three types of three layers (surface layer 1/intermediate layer/surface layer) were placed on a cooling roll set to 40° C. 2=4:17:4 discharge amount) was coextruded and solidified by cooling to obtain an unstretched sheet. Then, the film was stretched 3.3 times in the longitudinal direction at a film temperature of 85° C. by utilizing the difference in roll peripheral speed, and then the coating solution A1 shown in Table 1 below was applied to the surface layer 1 side of the longitudinally stretched film. After coating (after drying) to be 250 nm, it is introduced into a tenter, dried at 90° C. for 10 seconds, then stretched in the transverse direction by 4.3 times at 110° C., and heat-treated at 230° C. for 10 seconds. A polyester film having a thickness of 25 μm and a Sa on the back surface side of the adhesive layer of 55 nm was obtained by being relaxed in the lateral direction by 2%.

The polyester film thus produced was evaluated and found to have an adhesive force with a polymethylmethacrylate plate of 10 mN/cm, good adhesive properties, and a surface resistance of 1×10 ⁹ Ω, which was a good antistatic property. The characteristics of this film are shown in Table 7 below.

Examples 86-91:
A polyester film was obtained in the same manner as in Example 85 except that the coating composition was changed to the coating composition shown in Table 1. As shown in Table 7 below, the resulting polyester film had good adhesive strength and surface resistance.

Reference example 1 :
A polyester film was obtained in the same manner as in Example 1 except that the adhesive layer was not provided. Coating solution A4 shown in Table 1 below was applied on the polyester film without the adhesive layer so that the film thickness (after drying) of the adhesive layer was 350 nm, followed by drying at 100° C. for 1 minute, followed by offline coating. A polyester film having an adhesive layer laminated thereon was obtained. As shown in Table 7, the finished polyester film had good adhesive strength and surface resistance. However, the adhesive residue (transfer property) was strong.

Comparative Example 1:
A polyester film was obtained in the same manner as in Example 1 except that the adhesive layer and the functional layer were not provided. When the finished polyester film was evaluated, as shown in Table 8 below, it was a film having no adhesive strength and no surface resistance.

Comparative Examples 2-9:
A polyester film was obtained in the same manner as in Example 1, except that the coating composition was changed to the coating composition shown in Table 1. As shown in Table 8, the finished polyester film had no adhesive force or poor surface resistance.

Comparative Example 10:
On a polyester film having no adhesive layer and no functional layer obtained in Comparative Example 1, coating solution C1 shown in Table 1 below was applied at 100° C. for 3 minutes so that the adhesive layer had a thickness (after drying) of 20 μm. It was dried to obtain a polyester film having an adhesive layer formed by off-line coating. When the adhesive layer side of the obtained film was stuck to a polyester film having no adhesive layer and no functional layer of Comparative Example 1 and then cut, a protrusion of the components of the adhesive layer, which was not seen in Examples, was observed. However, there was a concern that contamination by the adhesive component may occur. The adhesive strength could not be measured well. Other properties were as shown in Table 8.

The film of the present invention is, for example, a resin plate, a metal plate or the like, in transportation, storage or during processing or surface protection film used for preventing stain adhesion during processing, etc. It can be suitably used for applications that require excellent adhesive strength and heat resistance, little dust adhesion, and good adhesive properties.

Claims (15)

On at least one surface of the polyester film, the glass transition point containing a 0 ℃ less resin and antistatic agent, the film thickness is a method for producing a laminated polyester film provided with a pressure-sensitive adhesive layer is 10μm or less, the glass transition The resin having a point of 0° C. or lower is an acrylic resin or a polyester resin, the adhesive force of the adhesive layer to the polymethylmethacrylate plate is 1 to 5000 mN/cm, and the adhesive layer is formed by in-line coating in the process of film production. After that, the laminated polyester film is stretched in at least one direction and heat-treated. The method for producing a laminated polyester film according to claim 1, wherein the temperature of the heat treatment is in the range of 180 to 270°C. The method for producing a laminated polyester film according to claim 1, wherein the adhesive layer is formed by applying an aqueous solution or an aqueous dispersion. The method for producing a laminated polyester film according to claim 1, wherein the adhesive layer has a thickness in the range of 1 to 600 nm. The method for producing a laminated polyester film according to claim 1, wherein the antistatic agent is a polymeric antistatic agent. The production of a laminated polyester film according to claim 5, wherein the polymer antistatic agent is at least one selected from a conductive polymer, a compound having an ammonium group, a compound having a sulfonic acid group, a polyether compound and a betaine compound. Method. The method for producing a laminated polyester film according to claim 1, wherein the adhesive layer contains a polyol compound or a polyether compound. The method for producing a laminated polyester film according to claim 1 , wherein the polyester resin contains a sulfonic acid, a sulfonic acid metal salt, a carboxylic acid, or a carboxylic acid metal salt as a functional group. The method for producing a laminated polyester film according to claim 1 , wherein the acrylic resin contains a carboxylic acid group, a carboxylic acid group, a sulfonic acid group, a sulfonic acid group, or a hydroxyl group. The method for producing a laminated polyester film according to claim 1 , wherein a functional layer is provided on the side of the polyester film opposite to the adhesive layer. The method for producing a laminated polyester film according to claim 10 , wherein the functional layer contains a release agent. The method for producing a laminated polyester film according to claim 10 , wherein the functional layer contains an antistatic agent. The method for producing a laminated polyester film according to claim 10 , wherein the functional layer is formed using a crosslinking agent. The method for producing a laminated polyester film according to claim 1, wherein an arithmetic mean roughness (Sa) of the surface of the laminated polyester film on the side opposite to the adhesive layer is 30 nm or more and 300 nm or less. The method for producing a laminated polyester film according to claim 1, wherein the content of the resin having a glass transition point of 0° C. or lower is in the range of 10 to 99.9% by weight in the adhesive layer.