JP2017203129A - Laminated polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated polyester film that can be suitably used for various applications requiring good adhesion characteristics and ultraviolet absorbing property, for example, an application as a surface protective film to be used to prevent scratches, to prevent deposition of dirt or the like on a resin plate, a metal plate or the like during transportation, storage or processing.SOLUTION: The laminated polyester film has an adhesive layer comprising a resin having a glass transition temperature of 0°C or lower and an ultraviolet absorbent on at least one surface of a polyester film. A production method of a laminated polyester film is provided, in which an adhesive layer is formed by disposing a coating layer comprising a resin having a glass transition temperature of 0°C or lower and an ultraviolet absorbent on at least one surface of a polyester film, and stretching the coating layer in at least one direction.SELECTED DRAWING: None

Description

  The present invention relates to a laminated polyester film. For example, there are few fish eyes as a surface protection film for preventing scratches and preventing adhesion of dirt during transport, storage and processing of resin plates, metal plates, etc. The present invention relates to a laminated polyester film that is excellent in mechanical strength and heat resistance and has good adhesive properties and ultraviolet absorption.

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

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

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

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

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

  In addition, some of the partner substrates to be protected are easily deteriorated and reacted with ultraviolet rays. In such a case, a conventional protective film cannot be used, and a protective film that can absorb (cut) ultraviolet rays has been demanded.

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

  The present invention has been made in view of the above circumstances, and the problem to be solved is that there are few fish eyes used for various surface protective films, etc., excellent mechanical strength and heat resistance, good adhesive properties and ultraviolet rays. It is providing the laminated polyester film which has an absorptivity.

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

  That is, the gist of the present invention is a laminated polyester film characterized by having an adhesive layer containing a resin having a glass transition point of 0 ° C. or less and an ultraviolet absorber on at least one side of the polyester film, and a polyester film A coating layer containing a resin having a glass transition point of 0 ° C. or lower and an ultraviolet absorber is provided on at least one side of the coating layer, and an adhesive layer is formed by stretching the coating layer in at least one direction. It exists in the manufacturing method of a laminated polyester film.

  According to the laminated polyester film of the present invention, as various surface protective films, it is possible to provide a film having few fish eyes, excellent mechanical strength and heat resistance, and having good adhesive properties and ultraviolet absorption. Target value is high.

  We think that it is necessary to change the base material of the base film significantly in order to reduce fish eyes, improve mechanical strength, and improve heat resistance, and as a result of various studies, they differ greatly from conventional polyolefin-based materials. It has been found that this can be achieved by using a polyester-based material. However, by greatly changing the material system of the base film, the adhesive properties are greatly lowered, which cannot be achieved with a general polyester film. Therefore, improvement was achieved by providing an adhesive layer on the substrate film, and the present invention was achieved.

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

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

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

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

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

  In the polyester layer, particles can be blended for the purpose of imparting slipperiness, preventing generation of scratches in each step, and improving anti-blocking properties. When the particles are blended, the kind of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples thereof include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid. Examples thereof include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used. Of these, silica particles and calcium carbonate particles are preferable because they are particularly effective in a small amount.

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

  Further, the particle content in the polyester layer cannot be generally specified because of the balance with the average particle diameter of the particles, but is usually 5% by weight or less, preferably in the range of 0.0003 to 3% by weight, more preferably 0. .0005 to 1% by weight. When the particle content exceeds 5% by weight, there may be a concern about problems such as dropout of particles and a decrease in transparency of the film. When there are no particles or when there are few particles, the slipperiness may be insufficient. Therefore, a device such as improving the slipperiness may be required by putting particles in the adhesive layer.

The shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc.
These series of particles may be used in combination of two or more as required.

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

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

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

  Although the production example of the film will be specifically described, it is not limited to the following production example, and a generally known film forming method can be adopted. In general, the resin is melted, formed into a sheet, and stretched for the purpose of increasing the strength and the film is formed. For example, when producing a biaxially stretched polyester film, first, a polyester raw material is melt-extruded from a die using an extruder, and the molten sheet is cooled and solidified with a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed. Next, the obtained unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is usually 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, the film is stretched in the direction orthogonal to the first stretching direction at 70 to 170 ° C., usually at a stretching ratio of 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing a heat treatment usually at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% can be mentioned. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

  A simultaneous biaxial stretching method can also be adopted for the production of the polyester film constituting the laminated polyester film. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is usually stretched and oriented in the machine direction and the width direction at a temperature controlled normally at 70 to 120 ° C., preferably 80 to 110 ° C. Is usually 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, formation of the adhesion layer which comprises a laminated polyester film is demonstrated. Examples of the method for forming the adhesive layer include methods such as coating, transfer, and lamination. Considering the ease of forming the adhesive layer, it is preferable to form it by coating.

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

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

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

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

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

  In the present invention, it is an essential requirement to have an adhesive layer containing a resin having a glass transition point of 0 ° C. or lower and an ultraviolet absorber.

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

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

  Among them, it is preferable to contain an aliphatic polyvalent carboxylic acid or an aliphatic polyvalent hydroxy compound as a constituent component in order to lower the glass transition point to 0 ° C. or lower. In general, since a polyester resin is composed of an aromatic polyvalent carboxylic acid and a polyvalent hydroxy compound including an aliphatic group, in order to lower the glass transition point than a general polyester resin, an aliphatic polyvalent compound is used. It is effective to contain a carboxylic acid. From the viewpoint of lowering the glass transition point, the aliphatic polycarboxylic acid preferably has a long carbon number, and usually has a carbon number of 6 or more (adipic acid), preferably a carbon number of 8 or more, more preferably 10 or more. The upper limit of the preferable range is 20.

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

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

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

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

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

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

The acrylic resin is a polymer composed of a polymerizable monomer including acrylic and methacrylic monomers (hereinafter, acrylic and methacryl may be abbreviated as (meth) acryl). These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers.
Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion (sometimes a mixture of polymers) is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included. However, in consideration of adhesive properties and adhesive residue on the adherend, it should not contain other polymers such as polyester and polyurethane (polymerizable monomers containing carbon-carbon double bonds (whether homopolymers or copolymers) (Meth) acrylic resin composed only of (possible)) is preferable.

  The polymerizable monomer is not particularly limited, but particularly representative compounds include, for example, various carboxyl groups such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Monomers, and salts thereof; such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate Various hydroxyl group-containing monomers; various such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate No (meta) acrylic Acid esters; various nitrogen-containing compounds such as (meth) acrylamide, diacetone acrylamide, N-methylolacrylamide or (meth) acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene Various vinyl esters such as vinyl propionate and vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane; phosphorus-containing vinyl monomers; Examples include various vinyl halides such as vinyl and biliden chloride; and various conjugated dienes such as butadiene.

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

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

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

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

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

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

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

  From the viewpoint of adhesive properties, the monomer content of the (meth) acrylic resin is such that the homopolymer has a glass transition point of 0 ° C. or less, usually 30% by weight or more as a percentage of the total (meth) acrylic resin. The range is preferably 45% by weight or more, more preferably 60% by weight or more, and still more preferably 70% by weight or more. The upper limit of the preferred range is 99% by weight. It is easy to obtain good adhesive properties by using in this range.

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

  As a more optimal form of (meth) acrylic resin for improving adhesive properties, the total content of (butyl) acrylate and 2-ethylhexylacrylate in (meth) acrylic resin is usually 30% by weight or more, The range is preferably 40% by weight or more, more preferably 50% by weight or more, still more preferably 60% by weight or more, and particularly preferably 70% by weight or more. The upper limit of the preferred range is 99% by weight. Although it depends on the composition of the (meth) acrylic resin to be used and the composition of the adhesive layer, 2-ethylhexyl is particularly useful when it is desired to eliminate the transfer of the adhesive component to the adherend with a small amount of the crosslinking agent. The acrylate content is usually 90% by weight or less, preferably 80% by weight or less.

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

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

  As the introduction of a hydroxyl group, various types such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate Examples thereof include copolymerizing a hydroxyl group-containing monomer. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable in consideration of industrial ease of handling.

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

  The ratio of the hydrophilic functional group-containing monomer in the (meth) acrylic resin is usually 30% by weight or less, preferably 1 to 20% by weight, more preferably 2 to 15% by weight, and further preferably 3 to 10% by weight. It is. By using it in the above range, it becomes easy to develop an aqueous system.

  The glass transition point of the (meth) acrylic resin for improving the adhesive properties is essential to be 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −20 ° C. or lower, and still more preferably. The lower limit of the preferable range is −80 ° C. It becomes easy to set it as the film which has the optimal adhesion characteristic by using in the said range. Moreover, when it is necessary to consider the reduction | decrease of transfer of the adhesion component to a to-be-adhered body, Preferably it is -70 degreeC or more, More preferably, it is -60 degreeC or more, More preferably, it is the range of -50 degreeC or more.

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

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

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

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

  From the viewpoint of improving the adhesive properties, the monomer forming the polyether is an aliphatic diol having a carbon number of usually 2 to 30, preferably 3 to 20, more preferably 4 to 12, particularly a linear aliphatic diol. Is a polyether polyol containing

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

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

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

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

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

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

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

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

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

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

  As the ultraviolet absorber, there are an organic ultraviolet absorber and an inorganic ultraviolet absorber. From the viewpoint of transparency, an organic ultraviolet absorber is preferable. The organic ultraviolet absorber may be used alone but is preferably a polymer type in consideration of bleed out prevention. For example, an acrylic resin, a polyester resin, or a urethane resin in which an ultraviolet absorbing structure is incorporated can be used. Among them, in particular, it is possible to improve the ultraviolet absorption performance by introducing an ultraviolet-absorbing structure into acrylate or methacrylate and polymerizing them to make an acrylic resin, which can contain many ultraviolet-absorbing structures. It is preferable from the viewpoint that it can be made. Although it does not specifically limit as an organic type ultraviolet absorber, For example, a benzotriazole type, a cyclic imino ester type, a benzophenone type etc. are mentioned. From the viewpoint of durability, a benzotriazole type and a cyclic imino ester type are more preferable, and a benzotriazole type ultraviolet absorber is more preferable in consideration of easiness of development to an acrylic resin and dispersibility in various solvents. . It is also possible to use two or more ultraviolet absorbers in combination.

  As the benzotriazole-based ultraviolet absorber, a compound in which a phenyl group, particularly a phenol group, is bonded directly to the benzotriazole structure is preferable from the viewpoint of ultraviolet absorption performance. Although not limited to the following, for example, 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxy) Ethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyhexyl) Phenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-tert-butyl-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5′- tert-Butyl-3 ′-(methacryloyloxyethyl) phenyl] -2H-benzo Riazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5 -Methoxy-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxy) Ethyl) phenyl] -5-tert-butyl-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole, and the like.

  For example, when an ultraviolet absorber is contained in an acrylic resin, a method of polymerizing by adding the ultraviolet absorber to a polymerizable monomer can be mentioned, but the content of the polymerizable monomer containing the ultraviolet absorber with respect to the entire acrylic resin Is usually 2% by weight or more, preferably 5 to 95% by weight, more preferably 10 to 80% by weight, still more preferably 20 to 70% by weight, and particularly preferably 30 to 60% by weight. When the content is too small, the ultraviolet absorption performance may not be improved even if the content of the compound containing the ultraviolet absorber is increased within a range where the adhesive performance can be maintained.

  When the ultraviolet absorber is contained in the acrylic resin, various conventionally known polymerizable monomers can be used as the copolymerizable monomer other than the polymerizable monomer containing the ultraviolet absorber. From the viewpoint of ease of polymerization, methyl (meth) acrylate and ethyl (meth) acrylate are preferred. Moreover, normal butyl acrylate and 2-ethylhexyl acrylate are preferable from the viewpoint of preventing a decrease in adhesive strength. Furthermore, from the viewpoint of aqueous dispersion such as when used in an aqueous dispersion, a compound containing a carboxylic acid group or a hydroxyl group, such as (meth) acrylic acid or 2-hydroxyethyl (meth) acrylate, is preferred.

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

  A functional layer may be provided on the surface of the film opposite to the adhesive layer for 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 due to adhesion of debris around the film due to peeling charging or frictional charging, an antistatic layer is provided. Providing is also a preferred form. The functional layer may be provided by coating, may be provided by in-line coating, or may employ offline coating. In-line coating is preferably used from the viewpoint of stabilization of production cost, release performance by in-line heat treatment, antistatic performance, and the like.

  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 conventionally known release agents can be used. Yes, for example, long-chain alkyl group-containing compounds, fluorine compounds, silicone compounds, waxes and the like. Among these, a long-chain alkyl compound and a fluorine compound are preferable from the viewpoint of low contamination and excellent blocking reduction, and a silicone compound is preferable when it is particularly important to reduce blocking. Also, wax is effective for improving the surface decontamination property. These release agents may be used alone or in combination.

  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 hexyl group, octyl group, decyl group, lauryl group, octadecyl group, and 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. . In view of heat resistance and contamination, a polymer compound is preferable. Further, from the viewpoint of effectively obtaining releasability, a polymer compound having a long-chain alkyl group in the side chain is more preferable.

The polymer compound having a long-chain alkyl group in the 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, and an acid anhydride.
Examples of the compound having such a reactive group include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, a reactive group-containing polyester resin, and a reactive group-containing poly (meth) acrylic resin. Among these, polyvinyl alcohol is preferable in view of releasability and ease of handling.

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

  In addition, a polymer compound having a long-chain alkyl group in the side chain can also be obtained by copolymerization of a long-chain alkyl (meth) acrylate polymer or a long-chain alkyl (meth) acrylate and 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. It is done.

  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 olefin compounds containing fluorine atoms, and aromatic fluorine compounds such as fluorobenzene. . From the viewpoint of releasability, a compound having a perfluoroalkyl group is preferable. Furthermore, the compound containing the long-chain alkyl compound which is mentioned later can also be used for a fluorine compound.

  Examples of the compound having a perfluoroalkyl group include perfluoroalkyl (meth) acrylate, perfluoroalkylmethyl (meth) acrylate, 2-perfluoroalkylethyl (meth) acrylate, and 3-perfluoroalkylpropyl (meth) acrylate. Perfluoroalkyl group-containing (meth) acrylates such as 3-perfluoroalkyl-1-methylpropyl (meth) acrylate and 3-perfluoroalkyl-2-propenyl (meth) acrylate, and polymers thereof, and perfluoroalkylmethyl vinyl ether 2-perfluoroalkyl ethyl vinyl ether, 3-perfluoropropyl vinyl ether, 3-perfluoroalkyl-1-methylpropyl vinyl ether, 3-perfluoroalkyl-2-propenyl vinyl Perfluoroalkyl group-containing vinyl ether and polymers thereof such as ether, and the like. In view of heat resistance and contamination, a polymer is preferable. The polymer may be a single compound or a polymer of multiple 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 later. Moreover, it is also preferable that it is a polymer with vinyl chloride from a viewpoint of adhesiveness with a base material.

  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, phenyl silicones having a phenyl group, and methyl phenyl silicone. Silicones having various functional groups can also be used, such as 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 both are used in combination to form silicones (addition reaction between vinyl groups and hydrogen silane). It can also be used.

  Moreover, it is also possible to use modified silicones such as acrylic graft silicone, silicone graft acrylic, amino-modified silicone, and perfluoroalkyl-modified silicone as the silicone compound. In view of heat resistance and contamination, it is preferable to use a curable silicone resin. As the type of curable type, any of the curing reaction types such as a condensation type, an addition type, and an active energy ray curable type can be used. Among these, a condensation type silicone compound is preferred from the viewpoint that there is little back surface transfer when it is formed into a roll.

  In the case of using a silicone compound, a polyether group-containing silicone compound is preferable from the viewpoint of less back transfer, good dispersibility in an aqueous solvent and high suitability for in-line coating. The polyether group may be present in the side chain or terminal of the silicone or may be present in the main chain. From the viewpoint of dispersibility in an aqueous solvent, it is preferably present in the side chain or terminal.

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

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

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

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

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

  Further, considering the temporal change and release performance of the functional layer and the contamination of various processes, it is preferable that the low molecular component (number average molecular weight is 500 or less) of silicone is as small as possible. The total ratio is usually 15% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less. In addition, when using condensation-type silicone, silicon-bonded vinyl groups (vinyl silane) and hydrogen groups (hydrogen silane) can cause changes in performance over time if left unreacted in the functional layer. The content of the functional group is preferably 0.1 mol% or less, more preferably not contained.

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

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

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

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

  The wax is a wax selected from natural waxes, synthetic waxes, and blended waxes thereof. Natural waxes are plant waxes, animal waxes, mineral waxes, and petroleum waxes. Examples of plant waxes include candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil and the like. Animal waxes include beeswax, lanolin, whale wax and the like. Examples of the mineral wax include montan wax, ozokerite, and ceresin. Examples of petroleum wax include paraffin wax, microcrystalline wax, and petrolatum. Synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, esters, ketones, and the like. 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 20000). The following polymers are also exemplified: polypropylene, ethylene / acrylic acid copolymer, polyethylene glycol, polypropylene glycol, polyethylene glycol / polypropylene glycol block or graft conjugate, and the like. Examples of the modified wax include montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives. The derivative herein is a compound obtained by any of purification, oxidation, esterification, saponification treatment, or a combination thereof. Hydrogenated waxes include hardened castor oil and hardened castor oil derivatives.

  Among these, synthetic waxes are preferable from the viewpoint of stable characteristics, among which polyethylene wax is more preferable, and oxidized polyethylene wax is more preferable. The number average molecular weight of the synthetic wax is usually in the range of 500 to 30000, preferably 1000 to 15000, more preferably 2000 to 8000, from the viewpoints of stability of properties such as blocking and handling properties.

  When providing an antistatic functional layer on the surface opposite to the adhesive layer of the film, the antistatic agent contained in the functional layer is not particularly limited, and conventionally known antistatic agents can be used. A polymer type antistatic agent is preferred because of its good heat resistance and moist heat resistance. Examples of the polymer type antistatic agent include a compound having an ammonium group, a polyether compound, a compound having a sulfonic acid group, a betaine compound, and a conductive polymer.

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

  Among the compounds having an ammonium group, compounds having a pyrrolidinium ring are also preferred in that they are excellent in antistatic properties and heat stability.

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

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

  Moreover, it is also preferable that it is a polymer which has a structure of following formula (1) at the point which is excellent in antistatic property and wet heat-resistant stability. A single polymer or copolymer, or a plurality of other components may be copolymerized.

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

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

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

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

  Examples of polyether compounds include polyethylene oxide, polyether ester amide, acrylic resins having polyethylene glycol in the side chain, and the like.

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

  Examples of the conductive polymer include polythiophene-based, polyaniline-based, polypyrrole-based, and polyacetylene-based polymers. Among them, for example, polythiophene-based polymers using poly (3,4-ethylenedioxythiophene) in combination with polystyrene sulfonic acid. Are preferably used. The conductive polymer is preferable to the other antistatic agents described above in that the resistance value is low. However, on the other hand, it is necessary to devise measures such as reducing the amount used in applications where coloring and cost are a concern.

  It is also a preferred embodiment that the functional layer that can be provided on the surface of the film opposite to the adhesive layer contains both the above-mentioned release agent and antistatic agent and has an antistatic release function.

  For the functional layer formation, various polymers such as polyester resin, acrylic resin, urethane resin, and various crosslinking agents are used in combination to improve the coating appearance and transparency, control slipperiness, and improve the strength of the functional layer. It is also possible to do. In particular, in terms 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, or a carbodiimide compound, and among them, a melamine compound is particularly preferable.

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

  These cross-linking agents are used in a design for improving the performance of the functional layer by reacting in the drying process or the film forming process. It can be inferred that unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof (compounds derived from the crosslinking agent) are present in the functional layer.

  As long as the gist of the present invention is not impaired, particles can be used in combination with the formation of the functional layer in order to improve blocking and slipperiness. However, when the functional layer has mold release performance, it often has sufficient blocking resistance and slipperiness, and therefore it may be preferable not to use particles from the viewpoint of the appearance of the functional layer.

  Furthermore, in the range not impairing the gist of the present invention, an antifoaming agent, a coating property improving agent, a thickener, an organic lubricant, an antistatic agent, an antioxidant, It is also possible to use a foaming agent, a dye, a pigment and the like in combination.

  As a ratio in the pressure-sensitive adhesive layer constituting the laminated polyester film, the resin having a glass transition point of 0 ° C. or less is usually 5 to 98% by weight, preferably 10 to 95% by weight, more preferably 20 to 90% by weight, Preferably it is 30 to 80 weight%, Most preferably, it is the range of 40 to 70 weight%. By using in the above range, sufficient adhesive force can be easily obtained, and the adhesive force can be easily adjusted. If the content is too small, the adhesive strength may decrease.

  As a ratio in the pressure-sensitive adhesive layer constituting the laminated polyester film, the UV absorber is not general because it depends on the film thickness of the pressure-sensitive adhesive layer, but is usually 2 to 95% by weight, preferably 5 to 90% by weight, more preferably. Is in the range of 10 to 80% by weight, more preferably 20 to 70% by weight, particularly preferably 30 to 60% by weight. When the content is too small, the ultraviolet absorption performance is inferior.

  In the laminated polyester film, when providing a functional layer having a releasing performance on the side opposite to the adhesive layer, the proportion of the releasing agent as a proportion in the functional layer is generally different because the appropriate amount varies depending on the type of releasing agent. However, it is usually in the range of 3% by weight or more, preferably 15% by weight or more, more 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 the release agent, the proportion in the functional layer is usually 5% by weight or more, preferably 15 to 99% by weight, more preferably 20 to 95% by weight, and still more preferably. It is in the range of 25 to 90% by weight. By using it in the above range, blocking reduction is effective. The proportion of the crosslinking agent is usually 95% by weight or less, preferably 1 to 80% by weight, more preferably 5 to 70% by weight, and still more preferably 10 to 50% by weight. Isocyanate compounds (in particular, blocked isocyanates blocked with active methylene compounds are preferred), and melamine compounds are particularly preferred from the viewpoint of reducing blocking.

  When a condensation type silicone compound is used as the release agent, the proportion in the functional layer is usually 3% by weight or more, preferably 5 to 97% by weight, more preferably 8 to 95% by weight, and still more preferably 10 to 10%. It is in the range of 90% by weight. By using it in the above range, blocking reduction is effective. Moreover, the ratio of a crosslinking agent is 97 weight% or less normally, Preferably it is 3-95 weight%, More preferably, it is 5-92 weight%, More preferably, it is the range of 10-90 weight%. Moreover, as a crosslinking agent, a melamine compound is preferable from a viewpoint of blocking reduction.

  When an addition-type silicone compound is used as a release agent, the proportion in the functional layer is usually 5% by weight or more, preferably 25% by weight or more, more preferably 50% by weight or more, and further preferably 70% by weight or more. Range. The upper limit of the preferable range is 99% by weight, and the more preferable upper limit is 90% by weight. By using in the said range, blocking reduction becomes effective and the external appearance of a functional layer also becomes favorable.

  When wax is used as the release agent, the proportion in the functional layer is usually 10% by weight or more, preferably 20 to 90% by weight, more preferably 25 to 70% by weight. By using it in the above range, blocking can be easily reduced. However, when a wax is used for the purpose of decontamination of the surface, the above ratio can be reduced, and usually 1% by weight or more, preferably 2 to 50% by weight, more preferably 3 to 30% by weight. It is a range. Moreover, the ratio of a crosslinking agent is 90 weight% or less normally, Preferably it is 10-70 weight%, More preferably, it is the range of 20-50 weight%. Moreover, as a crosslinking agent, a melamine compound is preferable from a viewpoint of blocking reduction.

  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 generally described because the appropriate amount varies depending on the type of the antistatic agent. Is usually in the range of 0.5% by weight or more, preferably in the range of 3 to 90% by weight, more preferably in the range of 5 to 70% by weight, and still more preferably in the range of 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 the adhesion of surrounding dust and the like may not be sufficient.

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

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

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

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

  Although the thickness of the adhesive layer depends on the material used for the adhesive layer, it cannot be said unconditionally. However, for better adjustment of adhesive strength, UV absorption performance, blocking characteristics, appearance of the adhesive layer, etc. Is usually 10 μm or less, preferably 10 nm to 4 μm, more preferably 30 nm to 3 μm, still more preferably 50 nm to 1 μm, and particularly preferably 80 to 900 nm.

  A general adhesive layer has a thickness of several tens of μm, but in such a case, for example, when used for manufacturing a polarizing plate, the adhesive film is used as a polarizing plate, a retardation plate, a viewing angle expansion plate, and the like. In some cases, the sticking out of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive layer may occur remarkably when it is bonded to the adherend and molded or cut.

  However, the protrusion can be minimized by adjusting the film thickness within the above-mentioned range. This effect becomes better as the adhesive layer is thinner. In addition, the thinner the adhesive layer, the smaller the absolute amount of the adhesive layer present on the film, and the more effective the adhesive paste component is transferred to the adherend. Furthermore, it can be seen that by setting the film thickness in the above-mentioned range, it is possible to achieve an appropriate adhesive strength that is not too strong. For example, for polarizing plate manufacturing processes, both adhesive performance and peeling performance that peels after bonding are achieved. When used in applications where it is necessary to achieve this, the adhesive-peeling operation can be easily performed, and an optimum film can be obtained.

  The thinner the film is, the more effective it is for blocking properties, and it is easier to manufacture when forming an adhesive layer by in-line coating. On the other hand, if the film thickness is too thin, the adhesive properties may vary depending on the configuration of the adhesive layer. Since it may disappear, use in the above-mentioned suitable range according to a use is preferable.

  The thickness of the functional layer is not general because it depends on the function to be provided. For example, the functional layer for imparting release performance or antistatic performance is usually 1 nm to 3 μm, preferably 10 nm to 1 μm. More preferably, it is 20-500 nm, More preferably, it is the range of 20-200 nm. By using the film thickness of the functional layer within the above range, it becomes easy to improve the blocking characteristics, improve the antistatic performance, or obtain a good appearance.

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

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

  Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed. The film constituting the laminated polyester film in the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

  As the adhesive strength of the adhesive layer, the adhesive strength with respect to the polymethylmethacrylate plate measured by the measurement method described later is usually 1 to 5000 mN / cm, preferably 3 to 1000 mN / cm, more preferably 5 to 500 mN / cm, More preferably, it is 7-300 mN / cm, Most preferably, it is the range of 10-100 mN / cm. By setting it as the said range, coexistence of adhesive performance and peeling performance which peels after bonding can be aimed at, and it becomes possible to set it as an optimal laminated body for various processes which perform adhesion-peeling operation. . Moreover, it becomes easy to make the blocking characteristic of a film favorable.

  As the ultraviolet absorption performance of the laminated polyester film, the transmittance at a wavelength of 350 nm is usually 70% or less, preferably 55% or less, more preferably 40% or less, still more preferably 30% or less, and particularly preferably 20% or less. Yes, and a preferable lower limit range is 0%. When outside the above range, the ultraviolet absorption performance is not sufficient, and depending on the adherend to be protected, deterioration due to ultraviolet rays may be observed.

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

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

(2) Measuring method of average particle diameter (d50: μm) Value of 50% of integration (weight basis) in equivalent spherical distribution measured using Shimadzu Corporation, centrifugal sedimentation type particle size distribution measuring device SA-CP3 type Was the average particle size.

(3) Method for Measuring Film Thickness of Adhesive Layer and Functional Layer The surface of the adhesive layer or functional layer was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, and the adhesive layer cross-section was measured using a TEM (Hitachi High Technologies Corporation H-7650, accelerating voltage 100 kV).

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

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

(6-1) Adhesive strength evaluation method (adhesive strength 1)
The pressure-sensitive adhesive layer surface of the laminated polyester film of the present invention having a width of 5 cm is applied to the surface of a polymethylmethacrylate plate (Kuraray Co., Ltd. (commercial glass (registered trademark), 1 mm thick)) with a 2 cm rubber roller having a width of 5 cm, The peel force after standing for 1 hour was measured. For the peeling force, “Ezgraph” manufactured by Shimadzu Corporation was used, and 180 ° peeling was performed under the condition of a tensile speed of 300 mm / min.

(6-2) Adhesive strength evaluation method (adhesive strength 2)
(6-1) except that the adhesive strength is evaluated using a polyester film surface (thickness 25 μm) without an adhesive layer obtained in Comparative Example 1 described later, instead of the polymethyl methacrylate plate (6-1). ) And the evaluation was performed in the same manner.

(7) Transmittance measurement method at a wavelength of 350 nm Using a spectrophotometer (UV-visible spectrophotometer V-570 and automatic absolute reflectance measuring device AM-500N manufactured by JASCO Corporation), transmission mode, asynchronous mode, Measure the transmittance of the functional layer surface in the wavelength range of 300 to 800 nm at an incident angle of 0 °, a detector of 0 °, N-polarized light, response fast, data collection interval of 1.0 nm, bandwidth of 10 nm, and scanning speed of 1000 m / min. The transmittance at a wavelength of 350 nm was evaluated.

(8) Measuring method of blocking property Two polyester films to be measured are prepared, and the adhesive layer side and the opposite side of the adhesive layer (the functional layer side when there is a functional layer) are overlapped to obtain an area of 12 cm × 10 cm Was pressed under the conditions of 40 ° C., 80% RH, 10 kg / cm ² , and 20 hours. Thereafter, the films were peeled according to the method specified in ASTM D1893, and the peel load was measured.
The lighter the peeling load, the harder it is to block and the better, preferably 100 g / cm or less, more preferably 30 g / cm or less, more preferably 20 g / cm or less, particularly preferably 10 g / cm or less, and most preferably 8 g / cm. The range is as follows. In addition, it described as "-" when sufficient measurement was not possible, such as exceeding 300 g / cm, or when a film fractured.

(9) Measuring method of surface resistance Using a high resistance measuring instrument: HP4339B and measuring electrode: HP16008B manufactured by Hewlett-Packard Japan, apply the polyester film after sufficient humidity adjustment in a measurement atmosphere of 23 ° C. and 50% RH. The surface resistance of the antistatic layer after 1 minute at a voltage of 100 V was measured.

(10) Dust adhesion evaluation method on the functional layer (antistatic layer) side After sufficiently conditioning the polyester film in a measurement atmosphere of 23 ° C. and 50% RH, the antistatic layer is rubbed 10 times with a cotton cloth. Gently bring this close to the finely crushed cigarette ash, observe the state of ash adhesion, and if the film does not adhere even if it comes into contact with the ash, then if the film comes in contact with the ash a little B, when C was attached in large quantities just by bringing the film close to ash.

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

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

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

<Method for producing polyester (D)>
In the production method of the polyester (A), the polyester (D) is produced using the same method as the production method of the polyester (A) except that 0.6 parts by weight of silica particles having an average particle diameter 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.
(Example compounds)
・ Polyester resin: (IA)
Water dispersion of polyester resin (glass transition point: −20 ° C.) having the following composition: Monomer composition: (acid component) dodecanedicarboxylic acid / terephthalic acid / isophthalic acid / 5-sodiumsulfoisophthalic acid // (diol component) ethylene Glycol / 1,4-butanediol = 20/38/38/4 // 40/60 (mol%)

・ 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)
・ 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 (% by weight)

・ UV absorber: (IIA)
Aqueous dispersion of acrylic resin containing ultraviolet absorbing compound having the following composition: 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole / methyl methacrylate / normal butyl acrylate / 2-hydroxy Ethyl methacrylate / acrylic acid = 40/30/23/5/2 (% by weight)
・ UV absorber: (IIB)
Aqueous dispersion of acrylic resin containing ultraviolet absorbing compound having the following composition: 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole / methyl methacrylate / normal butyl acrylate / 2-hydroxy Ethyl methacrylate / acrylic acid = 10/60/23/5/2 (% by weight)

Melamine compound: (III) hexamethoxymethylol melamine

・ Polyester resin: (IVA)
Water dispersion of polyester resin (glass transition point: 30 ° C.) having the following composition: Monomer composition: (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4 -Butanediol / diethylene glycol = 40/56/4 // 45/25/30 (mol%)
・ Polyester resin: (IVB)
Water dispersion of polyester resin (glass transition point: 50 ° C.) having the following composition: Monomer composition: (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4 -Butanediol / diethylene glycol = 50/46/4 // 70/20/10 (mol%)

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

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

・ Releasing agent (long chain alkyl group-containing compound): (VIA)
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 began to reflux, 100 parts of polyvinyl alcohol having an average degree of polymerization of 500 and a degree of saponification of 88 mol% was added in small portions over a period of about 2 hours. After the addition of polyvinyl alcohol, the reaction was completed by further refluxing for 2 hours. When the reaction mixture was cooled to about 80 ° C. and added to methanol, the reaction product was precipitated as a white precipitate. This precipitate was filtered off, added with 140 parts of xylene, and heated to dissolve completely. After repeating the operation of adding methanol again to precipitate several times, the precipitate was washed with methanol and dried and ground.

・ Releasing agent (fluorine compound): (VIB)
Fluorine compound aqueous dispersion having the following composition: Octadecyl acrylate / perfluorohexyl ethyl methacrylate / vinyl chloride = 66/17/17 (% by weight)

-Polyether group-containing condensed silicone: (VIC)
Polyether group-containing silicone having a number average molecular weight of 7000 (silicone siloxane) containing 1 polyethylene glycol (terminated with a hydroxyl group) having an ethylene glycol chain of 8 with respect to dimethylsiloxane 100 in the dimethyl silicone side chain in a molar ratio. When the bond is 1, the ether bond of the polyether group is 0.07 at a molar ratio). 3% of low molecular components having a number average molecular weight of 500 or less, no vinyl group (vinyl silane) and hydrogen group (hydrogen silane) bonded to silicon exist. In addition, this compound mix | blends the water which disperse | distributes sodium dodecyl benzenesulfonate in the ratio of 0.25 by making polyether group containing silicone 1 by weight ratio.

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

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

・ Antistatic agent (compound having ammonium group): (VIIB)
A polymer compound having a number average molecular weight of 50000, wherein the counter ion is a methanesulfonic acid ion, comprising a structural unit of the following formula (2).

Example 1:
A mixed raw material in which polyesters (A), (B), and (C) were mixed in proportions of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) were each 97 %, 3% of the mixed raw material is used as an intermediate layer raw material, each is supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. Coextruded and cooled and solidified with a layer structure of layers (surface layer / intermediate layer / surface layer = 3: 19: 3 discharge amount) to obtain an unstretched sheet.
Next, the film was stretched 3.3 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid A1 shown in Table 1 below was applied to the film thickness of the adhesive layer (dried) on one side of the film. (After) is applied to 450 nm, and coating liquid B1 shown in the following Table 3 is applied to the opposite side so that the film thickness (after drying) of the functional layer is 30 nm, and led to a tenter at 90 ° C. After drying for 10 seconds, the film was stretched 4.3 times at 110 ° C. in the transverse direction, heat treated at 230 ° C. for 10 seconds, and then relaxed 2% in the transverse direction to obtain a polyester film having a thickness of 25 μm.

  When the obtained polyester film was evaluated, the adhesive strength with the polymethyl methacrylate plate was 20 mN / cm, the adhesive property was good, the transmittance at 350 nm was as low as 27%, and the ultraviolet absorbing performance was also good. The properties of this film are shown in Table 3 below.

Examples 2-31:
In Example 1, it manufactured like Example 1 except having changed an application agent composition into the application agent composition shown in Table 1 or 2, and obtained the polyester film. As shown in Table 3 below, the obtained polyester film had good adhesive force and 350 nm transmittance.

Comparative Example 1:
In Example 1, it manufactured like Example 1 except not having provided an adhesion layer and a functional layer, and obtained a polyester film. When the obtained polyester film was evaluated, as shown in Table 4 below, there was no adhesive force, and the film had a high transmittance at 350 nm and a poor ultraviolet absorption performance.

Comparative Examples 2-6:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. As shown in Table 4, the obtained polyester film was a film having no adhesive force or a film having a high transmittance of 350 nm and a poor ultraviolet absorption performance.

Comparative Example 7:
On the polyester film without the adhesive layer and functional layer obtained in Comparative Example 1, the coating liquid C5 shown in Table 1 below was applied at 100 ° C. for 3 minutes so that the thickness (after drying) of the adhesive layer was 20 μm. Drying was performed to obtain a polyester film having an adhesive layer formed by off-line coating. When the polyester film was cut after bonding the pressure-sensitive adhesive layer side, the component of the pressure-sensitive adhesive layer that was not seen in the examples was seen to be contaminated by the pressure-sensitive adhesive component. Also, the adhesive strength could not be measured well. Other characteristics were as shown in Table 4.

  The film of the present invention has few fish eyes in applications such as surface protection films used for preventing scratches and preventing dirt adhesion during transportation, storage and processing of resin plates, metal plates, etc. It can be suitably used for applications that are excellent in mechanical strength and heat resistance and need to have good adhesive properties and ultraviolet absorption.

Claims (2)

A laminated polyester film comprising an adhesive layer containing a resin having a glass transition point of 0 ° C. or lower and an ultraviolet absorber on at least one side of the polyester film. A coating layer containing a resin having a glass transition point of 0 ° C. or less and an ultraviolet absorber is provided on at least one surface of a polyester film, and the coating layer is formed in at least one direction to form an adhesive layer. A method for producing a laminated polyester film.