KR20160102400A - Multilayer polyester film - Google Patents

Abstract

A laminated polyester film having a resin layer (X) on at least one surface of a polyester film, wherein the resin layer (X) comprises an acrylic structure (A), a urethane (B) and a naphthalene structure (C) And the change amount? R of the spectral reflectance before and after the resistivity treatment on the side of the resin layer (X) is not less than 0% and not more than 2%. Transparency and suppression of iris images (interference fringes) when the hard coating layer was laminated, and also showed excellent adhesion to the hard coat layer, adhesion at high temperature and high humidity (anti-wet heat adhesion), and immersion in boiling water Is excellent in adhesion (mabi-adhesive property) when it is immersed in hot water, and further, is excellent in heat-resistant water-transparency when immersed in hot water.

Description

Laminated polyester film {MULTILAYER POLYESTER FILM}

The present invention relates to a laminated polyester film having a resin layer on at least one side of a polyester film. More specifically, the present invention relates to an antireflective coating composition which is excellent in transparency, suppression of an iris pattern (interference fringe) when laminated with a hard coating layer, excellent initial adhesion with a hard coating layer, (UV resistance) after immersion in boiling water and adhesion (UV resistance) after UV irradiation, and further suppressing deterioration (whitening) of transparency when immersed in hot water (heat resistance water transparency) , And an oligomer-suppressing property.

As a representative of a display material, a touch panel is known, which is provided on a screen of an image display apparatus and gives a predetermined instruction to an information processing apparatus in accordance with the position where the screen is pressed. In many image display devices including an image display device provided with a touch panel, a hard coating film for preventing scratches is provided on the outermost surface thereof. 2. Description of the Related Art Recently, image display devices such as a cellular phone, a notebook computer, and a personal digital assistant (PDA) are being used outdoors. The hard coating film used in an image display apparatus for outdoor use including car navigation requires a property (inner UV adhesiveness) that does not cause peeling of the hard coat layer and the substrate film even when exposed to ultraviolet rays for a long time.

In recent years, there has been an increase in the use of handheld devices in bathrooms and the like. In hard-coated films used in portable devices such as portable telephones and mobile phones having a touch panel among them, adhesiveness under high temperature and high humidity Is strongly demanded. The hard coating film used for such applications is required to have adhesiveness against moisture and heat, which maintains adhesiveness even after holding for 250 hours to 500 hours under the environment of 85 캜 and 85% RH. In recent years, it has been demanded to have a self-adhesive property to maintain adhesiveness even after boiling at boiling water (100 DEG C), which is a more severe condition. There is an increasing demand for a laminated polyester film which is excellent in adhesion under such a harsh environment, has no appearance change, and is excellent in suppression of iris images (interference fringes) when a hard coating layer is laminated.

Further, when a high temperature heat treatment is performed in a processing step of a polyester film as a base material, and when the display device is stored for a long time under high temperature and high humidity, oligomer precipitation occurs from the polyester film to deteriorate transmittance and visibility There has been a problem, and it is required to suppress precipitation of oligomers (oligomer-suppressing property).

Therefore, conventionally, a method of imparting ease of adhesion to the surface of the polyester film by various methods has been studied. For example, a method of forming an acrylic-modified polyurethane as a primer layer on the surface of a film (Patent Document 1), a method of forming a copolymerized polyester resin and an isocyanate-based crosslinking agent as a primer layer (Patent Document 2), a polyurethane resin and a carbodiimide A method of forming a primer layer containing an acryl-urethane copolymer resin, an isocyanate-based compound, an oxazoline-based compound, and a carbodiimide-based compound (Patent Document 4) , And a method of forming a compound having 30 to 70% of a melamine compound and a naphthalene ring and a urethane resin as a primer layer (Patent Document 5). As a method for suppressing oligomer precipitation, a method of forming a coating film using an acrylic modified polyester on the surface of a resin film (Patent Documents 6 and 7), a method of adding additives such as resins, mineral oils, and crosslinking agents having specific functional groups to the resin layer (Patent Documents 8 and 9) have been proposed.

Japanese Patent Application Laid-Open No. 2000-229394 Japanese Patent Application Laid-Open No. 2003-49135 Japanese Patent Application Laid-Open No. 2001-79994 WO 2007/032295 Pamphlet Japanese Patent No. 4916339 International Publication No. 2011/122209 brochure Japanese Patent Application Laid-Open No. 2003-012841 Japanese Patent Application Laid-Open No. 2006-281498 Japanese Patent Application Laid-Open No. 2002-127621

In Patent Document 1, although the initial adhesion with the ultraviolet curable ink is excellent, the problems such as the adhesion in the moisture-resistant and heat-resistant environment and the lack of adhesion to the ink are liable to occur.

In the method described in Patent Document 2, although the effect of improving the anti-wet heat adhesion is recognized to be constant, the adhesiveness with the UV curable resin, the solventless UV curable resin constituting the prism lens layer among them is insufficient.

In the methods described in Patent Documents 3 and 4, there is a problem that visibility (interference fringes) becomes insufficient because the heat resistance and adhesiveness to moisture and heat are improved in addition to the initial adhesiveness, but the refractive index of the resin itself is low.

In the method described in Patent Document 5, the compound having a naphthalene ring is suppressed from lowering the refractive index to improve the visibility, and the initial adhesion is also improved. However, there has been a problem that the adhesiveness against moisture and heat resistance and the resistance against the self-adhesion are insufficient. In addition, since the method described in Patent Document 5 contains a large amount of melamine compound, there is a problem that process contamination due to volatilization of the melamine compound in the production process becomes a problem or that the melamine compound generates formaldehyde harmful to the human body through the crosslinking reaction .

In addition, as in Patent Documents 6 and 7, the method of providing an acrylic-modified polyester having a glass transition point of a certain temperature or higher on the surface of the film has an effect of preventing oligomer precipitation, but has a problem of adhesion with the laminate.

In addition, when additives such as mineral oil and crosslinking agent are used as in Patent Documents 8 and 9, the additive itself bleeds out on the surface of the resin layer at the time of forming a resin layer or at the time of film formation, and as in the case where oligomers are precipitated, There is a problem that contamination or the like of the transferring process of the film is caused.

As described above, the conventional techniques can not satisfy both suppression of interference fringe (visibility), anti-wet heat adhesion, anti-magnetic adhesion and even UV resistance. Further, in the prior art, heat resistance water resistance and oligomer inhibition property could not be satisfied.

Accordingly, it is an object of the present invention to overcome the aforementioned disadvantages and to provide a laminated polypropylene resin composition which is excellent not only in initial adhesiveness but also excellent in heat and moisture resistance, UV resistance and UV resistance, And an object of the present invention is to provide an ester film. It is another object of the present invention to provide a laminated polyester film having excellent properties as described above even when a small amount or no melamine compound is contained.

The laminated polyester film according to the present invention has the following constitution.

(1) A laminated polyester film having a resin layer (X) on at least one side of a polyester film, wherein the resin layer (X) comprises an acrylic structure (A), a urethane structure (B) and a naphthalene structure , And the change amount? R of the spectral reflectance before and after the resistivity treatment on the side of the resin layer (X) is not more than 0% and not more than 2% without containing the carbodiimide structure (G).

(2) The laminated polyester film characterized in that the surface zeta potential of the resin layer (X) is -20 mV or more.

(3) The laminated polyester film according to (1) or (2), wherein the minimum value of the spectral reflectance in the wavelength range of 450 nm to 650 nm on the side of the resin layer (X) is 4.5% or more and 6.0% or less.

(4) The method according to any one of (1) to (4), wherein the resin layer (X) comprises a polyester resin (b) having an acrylic urethane copolymer resin (a) and a naphthalene skeleton, an isocyanate compound (c) and an oxazoline compound (1) to (3), wherein the laminated polyester film is a formed layer.

(5) The acrylic resin composition according to any one of the above items (1) to (4), wherein the aggregate containing the acrylic urethane copolymer resin (a) of the resin layer (X) has a dispersion index of 5 or less and the acryl / urethane copolymer resin (4). ≪ / RTI >

(6) The polyester resin (b) is a copolymerized polyester resin containing an aromatic dicarboxylic acid component containing a sulfonic acid metal base in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester Is a polyester film according to any one of (4) to (5).

(7) The laminated polyester film according to any one of (4) to (6), wherein the polyester resin (b) comprises a diol component represented by the following formula (1).

(- represents a _{(C n H 2n O) m} -H (n = 2 or more than 4, m = 1 or more integer of 15) wherein, X ^1, X ²⁾

(8) The resin composition according to any one of (4) to (7), wherein the solid content weight ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) in the coating composition is 40/60 to 5/95 Laminated polyester film.

(9) The coating composition according to any one of (1) to (10), wherein the sum of the solid content weight of the acrylic urethane copolymer resin (a) and the polyester resin (b) is 100 parts by weight, the isocyanate compound , And the oxazoline compound (d) in an amount of 20 to 50 parts by weight, based on the solids weight, of the layered polyester film.

(10) The coating composition according to any one of (1) to (5), further comprising 5 to 30 parts by weight of the melamine compound (e) when the sum of the solid content weight of the acrylic urethane copolymer resin (9). ≪ / RTI >

The laminated polyester film of the present invention is excellent in transparency, suppression of iris patterns (interference fringes) when a hard coating layer is laminated, excellent initial adhesion with a hard coating layer, adhesiveness under high temperature and high humidity (UV resistance) after immersion in boiling water, adhesion (immersion adhesion) when immersed in boiling water, adhesion after UV irradiation (UV resistance), and further suppression of transparency (whitening) Heat-resistant water-transparency) and oligomer-suppressing properties.

1 is a cross-sectional view schematically showing a laminated polyester film having a large dispersion index.
2 is a cross-sectional view schematically showing a laminated polyester film having a small dispersion index.
3 is a cross-sectional view schematically showing a laminated polyester film having a small dispersion index.
4 is a diagram schematically showing a surface on which a cross-section of the laminated polyester film is observed.

Hereinafter, the laminated polyester film of the present invention will be described in detail.

The laminated polyester film of the present invention has a polyester film to be a substrate, and the polyester film has a resin layer (X) on at least one side.

(1) Polyester film

The polyester constituting the polyester film to be the base material in the present invention is a general term for polymers having ester bond as a main bonding chain of the main chain. Preferable examples of the polyester include at least one constituent resin selected from the group consisting of ethylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene terephthalate and 1,4-cyclohexanedimethylene terephthalate, . These constituent resins may be used alone or in combination of two or more. The intrinsic viscosity (measured in o-chlorophenol at 25 캜) of the above-mentioned polyester is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 0.8 dl / g, It is suitable.

The polyester may contain various additives such as antioxidants, heat stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents, May be added so as not to deteriorate.

It is preferable to use a biaxially oriented polyester film as the polyester film. Here, the term " biaxial orientation " means a pattern of biaxial orientation by wide angle X-ray diffraction. The biaxially oriented polyester film can be generally obtained by stretching a polyester sheet in an unstretched state by about 2.5 to 5 times in the sheet longitudinal direction and the transverse direction, respectively, and then conducting a heat treatment.

The polyester film itself may be a laminated structure of two or more layers. Preferred examples of the laminated structure of the polyester film of the present invention include a composite film having an inner layer portion and a surface layer portion and a composite film formed by forming a layer containing substantially no particles in the inner layer portion and containing particles only in the surface layer portion, . The polyester constituting the inner layer portion and the surface layer portion may be the same or different.

The thickness of the polyester film is not particularly limited and may be appropriately selected depending on the purpose and the type of the film. From the viewpoints of mechanical strength and handling properties, the thickness is usually preferably 10 to 500 占 퐉, more preferably 38 to 250 占 퐉, Lt; / RTI > The polyester film may be a composite film by co-extrusion, and the obtained film may be a film back by various methods.

(2) The resin layer (X)

The laminated polyester film of the present invention is a laminated polyester film having a resin layer (X) on at least one side of a polyester film, wherein the resin layer (X) has an acrylic structure (A), a urethane structure (B) and a naphthalene structure C) and does not contain the carbodiimide structure (G), and the change amount? R of the spectral reflectance before and after the resistivity treatment on the resin layer (X) side is 0% or more and 2% or less. Film.

The laminated polyester film of the present invention is excellent in transparency, suppression of iris patterns (interference fringes) when laminated with a hard coating layer, excellent initial adhesion to a hard coating layer, adhesion at high temperature and high humidity (UV resistance) after immersion in boiling water, adhesion (immersion adhesion) when immersed in boiling water, adhesion after UV irradiation (UV resistance), and further suppression of transparency (whitening) Heat water water transparency), and oligomer suppression.

The resin layer (X) of the present invention contains an acrylic structure (A) and a urethane structure (B), and thus can be used for various purposes such as initial adhesion with a hard coating layer, Can be given. By including the naphthalene structure (C) having a high refractive index structure in the resin layer (X), the refractive index of the resin layer (X) can be set to a middle value between the refractive index of the polyester film and the refractive index of a general hard coating. It is possible to suppress interference fringes when the coating layer is laminated. On the other hand, by excluding the carbodiimide structure (G) from the resin layer (X), it is possible to maintain transparency of hot water when immersed in hot water.

The laminated polyester film of the present invention is a laminated polyester film having a resin layer (X) on at least one side of a polyester film, wherein the resin layer (X) comprises a polyester having an acrylic urethane copolymer resin (a) and a naphthalene skeleton Is preferably a layer formed using a coating composition comprising a resin (b), an isocyanate compound (c) and an oxazoline compound (d).

Here, the change amount? R of the spectral reflectance before and after the blush treatment test in the present invention means that when the blush treatment test in which the laminated polyester film is immersed in boiling water (100 占 폚) for 5 hours is carried out, (%) Of the amount of change of the spectral reflectance before and after the self-abrasion treatment test when the spectral reflectance is measured from the side (X) side.

The spectral reflectance (%) before the self-treatment treatment test and the spectral reflectance (%) after the self-treatment treatment test are obtained based on the evaluation method of the change amount? R of the spectral reflectance before and after the (8) self- ? R is the absolute value of the variation obtained by subtracting the average spectral reflectance (%) from the spectral reflectance (%) before the mercury-free test process (? R = | the average spectral reflectance before the mercury- %).

The change amount? R of the spectral reflectance before and after the mercury treatment test needs to be 0% to 2%, more preferably 0% to 1.8%, further preferably 0% to 1.5% Do.

When the change amount? R of the spectral reflectance before and after the mercury treatment test as measured from the resin layer (X) side is 0% or more and 2% or less, the laminated polyester film of the present invention has transparency, (Viscoelasticity) of the phase shape (interference fringe), excellent initial adhesion with the hard coat layer and adhesion to anti-wet heat and surprise, and remarkably excellent adhesion to the hard coating layer Lt; / RTI >

The reason for this is presumed as follows. The change of the spectral reflectance when measured from the side of the resin layer (X) occurs according to the change of the refractive index due to the change of the composition of the resin layer (X). Therefore, the change of the spectral reflectance before and after the mercury treatment test means that the refractive index of the resin layer (X) is changed by the mercury treatment test. That is, the composition of the resin layer X is changed. As a compositional change of the resin layer (X) by the mercury treatment test, leakage of the composition component of the resin layer (X) to the number of grains and invasion of the number of grains into the resin layer (X) are considered. When the change amount? R of the spectral reflectance before and after the mercury treatment test is 0% or more and 2% or less, the change in the composition of the resin layer (X) by the mercury treatment test is small. Therefore, even after immersion in hot water or boiling water, It is possible to exhibit good adhesion and mastic resistance.

On the other hand, when the change amount? R of the spectral reflectance before and after the mercury treatment test exceeds 2%, the composition change of the resin layer (X) by the mercury treatment test is large, so that the anti-wet heat adhesion and the anti-

In the present invention, as a method of forming the resin layer (X) in which the variation amount of the spectral reflectance before and after the mercury treatment test is in a range of 0% or more and 2% or less, it is preferable that the resin layer (X) By setting the dispersion index of the aggregate to 5 or less, the resin layer X in which the change amount? R of the spectral reflectance before and after the self-treatment treatment is 0% or more and 2% or less can be formed.

The resin layer (X) of the present invention preferably has a surface zeta potential of -20 mV or higher.

By setting the surface zeta potential of the resin layer (X) to -20 mV or more, the polarity of the surface of the resin layer (X) can be reduced and the penetration or adsorption of water into the resin layer (X) It is possible to exhibit the self-adhesive property.

The method for adjusting the surface zeta potential of the resin layer (X) to -20 mV or more is not particularly limited. Examples of the method for adjusting the surface zeta potential include a method of adjusting the structure of the resin contained in the resin layer (X) or the composition ratio of the chemical structure, a physical treatment such as a corona treatment or a plasma treatment, A method of introducing an anionic functional group such as a carboxyl group or a hydroxyl group onto the surface of the resin layer X by performing a chemical treatment such as a treatment or the like and a method of performing a discharge treatment such as a corona treatment or a plasma treatment on the resin layer .

The laminated polyester film of the present invention is a laminated polyester film in which the resin layer (X) comprises a polyester resin (b) having an acrylic urethane copolymer resin (a), a naphthalene skeleton, a coating material containing an isocyanate compound (c) and an oxazoline compound Is a layer formed using a composition and the aggregate containing the acrylic urethane copolymer resin (a) of the layer (X) is preferably a laminated polyester film having a dispersion index of 5 or less, more preferably 3 or less. The dispersion index in the present invention refers to a dispersion index of an aggregate containing an acrylic urethane copolymer resin (a) having a size of 40 nm or more observed in a specific area when a cross section of the resin layer (X) is observed using a transmission electron microscope Represents the average number. The number of agglomerates having a size of 40 nm or more including the acryl-urethane copolymer resin (a) observed at a field of view (Z direction x direction: 500 nm x 1200 nm) at a magnification of 20,000 was measured. The number of aggregates obtained is converted into the number per predetermined area (120000 nm ² ) by the following formula.

(Number of agglomerates having an observed size of 40 nm or more) x 120000 / area occupied by the resin layer (X) in the visual field area

This observation was performed for 10 fields of view, and the average number of aggregates containing the acrylic urethane copolymer resin (a) present per a predetermined area was calculated, and the value obtained by rounding off the number of the first digits of the decimal point was regarded as a dispersion index. Here, the size of the aggregate refers to the maximum diameter (i.e., the long diameter of the aggregate and represents the longest diameter of the aggregate) of the aggregate, and also the maximum diameter of the aggregate in the case of the aggregate having the cavity therein.

The dispersion index represents an integer of 0 or more. The dispersion index in the present invention is preferably 5 or less, and more preferably 3 or less.

In order to confirm the dispersion index of the resin layer (X), it can be determined by observing the cross-sectional structure of the layer (X) using a transmission electron microscope (TEM).

First, a cross section observation of the resin layer (X) will be described.

A sample of the cross section of the layer (X) is prepared on the layered polyester film by the RuO ₄ -discriminated thin film slice method. The cross section of the obtained sample is observed with respect to a field area (Z direction x direction: 500 nm x 1200 nm) where an acceleration voltage is 100 kV and a magnification is observed at a magnification of 20,000 times, for example, the structure shown in Figs. 1 to 3 can be confirmed.

Here, the cross-sectional observation of the resin layer (X) means the cross-sectional observation of the XZ plane in Fig. Here, the dyeing with RuO ₄ is capable of dyeing a portion having an acrylic skeleton.

For example, a multilayer polyester film containing only a polyester resin (b) having a naphthalene skeleton of the resin layer (X), an isocyanate compound (c) and an oxazoline compound (d) In one case, the black part is not observed because it does not contain the acrylic urethane copolymer resin (a) stained by RuO ₄ . On the other hand, the resin layer (X) is an acrylic-urethane copolymer resin (a) subjected to a sample produced similarly with respect to the laminated polyester film including only, when observed a cross-section, an acrylic-urethane copolymer resin to be dyed by RuO ₄ (a ), The whole of the resin layer (X) becomes black. From this result, it can be judged that the black part is the part including the acrylic urethane copolymer resin (a).

When the layer X has a sea-island structure as shown in Fig. 1, the island of a black part (for example, an acryl-urethane copolymer resin) in the thickness direction of the layer X, The dispersion index increases. On the other hand, in the case of the structures of Figs. 2 and 3, the dispersion index is small because the number of black islands is small.

When the dispersion index observed by the above-mentioned method exceeds 5, it was judged that the resin layer (X) does not form a uniform dispersion structure. On the other hand, when the dispersion index was 5 or less, it was judged that the resin layer X formed a uniform dispersion structure.

Wherein the resin layer (X) is a layer formed by using a coating composition comprising an acrylic urethane copolymer resin (a), a polyester resin (b) having a naphthalene skeleton, an isocyanate compound (c) and an oxazoline compound (d) The dispersion index of the aggregate containing the acryl-urethane copolymer resin (a) of the layer (X) is preferably 5 or less, more preferably 5 or less, further preferably 2 or less. With this range, the laminated polyester film of the present invention is excellent in transparency, suppression of iris images (interference fringes) when the hard coat layer is laminated (visibility), excellent initial adhesion with the hard coat layer, (Adhesion resistance) when immersed in boiling water (adhesion resistance to UV rays) and adhesion after UV irradiation (resistance to UV rays) can be also manifested.

The reason for this is presumed as follows. When the acrylic urethane copolymer resin (a) has a uniform dispersion structure with a dispersion index of 5 or less as shown in Figs. 2 and 3, the acrylic urethane copolymer resin (a) It is also distributed on the surface. Also, the isocyanate compound (c) and the oxazoline compound (d) excellent in adhesion to the hard coat layer are also distributed on the surface of the layer (X). As a result, the mutual action of the hard coat layer and the layer (X) is increased and the adhesive strength to the hard coat layer is greatly improved. In addition, when the force for peeling the laminated hard coat layer is applied, It is possible to exhibit excellent anti-wet heat adhesion, anti-martial adhesion and anti-UV adhesion. When the acrylic urethane copolymer resin (a) has a uniform dispersion structure in the resin layer (X), the acrylic / urethane copolymer resin (a) having a low refractive index is not locally gathered. X) becomes uniform, and the layer (X) having a uniform refractive index in the thickness direction can be formed. As a result, it is preferable to suppress the iris pattern (interference fringe) when the hard coating layer is laminated (visibility).

On the other hand, when the dispersion index exceeds 5, defective dispersion of the resin causes deterioration of transparency, anti-wet heat adhesion, anti-magnetic adhesion and UV resistance.

In the present invention, as a method for forming a uniform dispersion structure having a dispersion index of not more than 5 in the resin layer (X), for example, a polyester resin (b) having a naphthalene skeleton, A copolymerized polyester resin containing an aromatic dicarboxylic acid component containing a base in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester is used, and each resin (a) to (d) The resin layer (X) can form a structure having a dispersion index of 5 or less.

In the laminated polyester film of the present invention, the minimum value of the spectral reflectance in the wavelength range of 450 nm or more and 650 nm or less on the side of the resin layer (X) is preferably 4.5% or more and 6.0% or less.

The reason is that when the absorption wavelength of human photocells is in the range of 450 nm or more and 650 nm or less and the maximum value of the spectral reflectance in this wavelength range is 4.5% or more and 6.0% or less, the iris pattern shape (interference nonuniformity) It is difficult to see.

In the present invention, as a method for forming a laminated polyester film in which the minimum value of the spectral reflectance in the wavelength range of 450 nm to 650 nm on the side of the resin layer (X) is 4.5% or more and 6.0% or less, for example, a naphthalene skeleton Wherein the polyester resin (b) having an aromatic dicarboxylic acid component containing a sulfonic acid metal base is contained in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester, wherein a ratio of each of the resins of (a) to (d) is within a certain range so that the minimum value of the spectral reflectance in the wavelength range of 450 nm or more and 650 nm or less on the layer (X) side is 4.5% or more and 6.0% A film can be formed.

The reason for this is that, for example, the polyester resin (b) having a naphthalene skeleton contains an aromatic dicarboxylic acid component containing a sulfonic acid metal base in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester When an ester resin is used, compatibility with the acrylic urethane copolymer resin (a) and other resins is improved, and a uniform dispersion structure can be formed. As a result, the refractive index in the resin layer (X) becomes uniform, and a laminated polyester film having a minimum value of the spectral reflectance of 4.5% or more and 6.0% or less in the wavelength range of 450 nm or more and 650 nm or less on the side of the resin layer can do. By setting the reflectance within this range, suppression (visibility) of the iris pattern (interference fringe) is possible from the principle of optical interference when the hard coating layer is laminated.

The reason for this will be described in detail. The suppression of the iris phase shape becomes possible by controlling the refractive index and the film thickness of the resin layer (X). When the refractive index of the resin layer (X) is set to the refractive index of the value of the rising average of the refractive index of the hard coat layer which is laminated with the polyester film as the base, the iris phase shape can be most suppressed. For example, when the hard coating layer comprises acrylic resin and the base polyester film comprises polyethylene terephthalate, the refractive index of the hard coating layer is 1.52 and the refractive index of the polyester film of the substrate is 1.65. Therefore, The refractive index of the phosphorus layer X becomes 1.58, which is a rising average thereof. The refractive index of the coating film is correlated with the reflectance in the wavelength range of 450 nm to 650 nm so that the minimum value of the spectral reflectance in the wavelength range of 450 nm to 650 nm of the resin layer X is 4.5% By using a polyester film, the shape of the iris image can be suppressed.

Further, in the laminated polyester film of the present invention, a coating composition having a solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) of 40/60 to 5/95 is applied to at least one surface of the polyester film A laminated polyester film obtained by forming the layer (X) is preferable because adhesion between the laminated polyester film and the hard coat layer becomes good. When the sum of the solid content weight of the acrylic urethane copolymer resin (a) and the polyester resin (b) in the coating composition is 100 parts by weight, 3 to 20 parts by weight of the isocyanate compound (c) If the layered polyester film obtained by applying the coating composition containing the compound (d) in an amount of 20 to 50 parts by weight as solids weight to the resin layer (X) is used, the acrylic urethane copolymer resin (a) A laminated polyester film having a uniform dispersion structure with a dispersion index of 5 or less can be formed, and the laminated polyester film is preferable because it has good anti-wet heat adhesion, anti-magnetic adhesion and UV resistance.

As a result, it has been found that the resin layer exhibits high transparency, adhesion to a hard coat layer, anti-wet heat adhesion, anti-magnetic adhesion, UV resistance, and suppression of interference fringe (visibility) when laminated with a hard coat layer .

In addition, the laminated polyester film of the present invention is also excellent in suppressing deterioration (whitening) of transparency (heat resistance water transparency) when immersed in hot water. The heat-resistant water transparency can be evaluated by the amount of change in film haze ΔHz before and after the mercury treatment test. The amount of film haze change DELTA Hz before and after the self-abrasion treatment test indicates the amount of change in film haze before and after the self-abrasion treatment test in which the laminated polyester film is immersed in hot water at 100 deg. Specifically, the value obtained by subtracting the haze value of the laminated polyester film before the self-bias treatment test from the haze value of the laminated polyester film after the self-bias treatment test is represented by the film haze change amount? Hz (? Hz = film haze after self- Film haze before the treatment test). The detailed measurement method will be described later. In the present invention, a film having a film haze variation DELTA Hz before and after the blush treatment test of less than 5.0% is assumed to be a film having excellent heat-resistant water transparency.

By setting the amount of film haze change DELTA Hz before and after the self-extinguishing treatment test to less than 5.0%, it is possible to obtain a laminated polyester film which can suppress the deterioration of transparency even when used for a long time under a harsh environment such as high temperature and high humidity. It is more preferable that the film haze variation DELTA Hz before and after the mercury treatment test is less than 4.5%. Examples of a method for obtaining a laminated polyester film in which the amount of change in film haze before and after the mercury treatment test is less than 5.0% include the use of the oxazoline compound (d) in the coating composition for forming the resin layer (X) A method of setting the ratio of the resin or the compound of (a) to (d) in the composition to an arbitrary constant range, and a method of combining these methods.

The reason is as follows. From the above examination, it has been confirmed that when a self-leveling test is conducted on a laminated polyester film having a resin layer, fine voids are formed on the surface of the resin layer and the haze of the laminated polyester film is increased. It is considered that the unreacted component of the crosslinking component contributing to the adhesion is leaked out by the self-abrasion treatment test in that the haze increases with the increase of the void generation amount and the adhesion decreases. When the oxazoline compound (d) is used, compatibility with the polyester resin (b) having a naphthalene skeleton and other resins can be improved, a resin layer having a uniform dispersion structure can be formed, It was thought that the oxazoline compound or the unreacted component thereof was difficult to flow out in the mercury treatment test because the high resin layer could be formed and as a result the formation of voids was suppressed and the haze change amount could be greatly suppressed.

In addition, the laminated polyester film of the present invention is also excellent in suppressing the precipitation of oligomer (oligomer suppressing property) under high temperature. The oligomer inhibition property can be evaluated by the film haze change amount (? Hz after heating) before and after the high temperature heat treatment. The amount of change in film haze before and after the high-temperature heat treatment (ΔHz after heating) indicates the amount of change in film haze before and after heating the laminated polyester film at 150 ° C. Specifically, the value obtained by subtracting the haze value of the laminated polyester film before the heat treatment from the haze value of the laminated polyester film after the heat treatment is a change in film haze before and after the high temperature heat treatment (ΔHz after heating) (ΔHz after heating = Film haze - Film haze before heat treatment). The detailed measurement method will be described later. In the present invention, a film having a film haze change amount (? Hz after heating) of less than 2.5% before and after the heat treatment is assumed to be a film having excellent oligomer suppressing properties.

By setting the amount of change in film haze before and after the heat treatment (ΔHz after heating) to be less than 2.5%, it is possible to prevent the deterioration of the transparency and the deterioration of the visibility even when the high temperature heat treatment is performed in the processing step of the polyester film . It is more preferable that the film haze change amount (? Hz after heating) before and after the heat treatment is less than 2.0%. As a method for obtaining a laminated polyester film in which the amount of change in film haze before and after the heat treatment (ΔHz after heating) is less than 2.5%, for example, the oxazoline compound (d) is used in the coating composition for forming the resin layer , A method of setting the ratios of the resins (a) to (d) in the coating composition to an arbitrary constant range, and a method of combining these methods.

The reason is as follows. The oligomer-inhibiting property is expressed by reacting and crosslinking the polyester resin (b) having a naphthalene skeleton with the oxazoline compound (d). When the oxazoline compound (d) is used in the coating composition for forming the resin layer (X), or when the ratio of the resin or the compound (a) to the compound (d) in the coating composition is within a certain constant range, The ester resin (b) and the oxazoline compound (d) react rapidly and a resin layer having a high degree of crosslinking can be formed. Therefore, oligomers are hardly diffused in a high-temperature heat treatment and the amount of film haze change can be greatly suppressed I think.

When a carbodiimide compound (g) or the like containing a carbodiimide structure (G) represented by the formula (2) is added to the coating composition, a polyester resin (b) having a naphthalene skeleton, The reaction of the isocyanate compound (c), the oxazoline compound (d), and the melamine compound (e) is inhibited, so that a resin layer having a high degree of crosslinkability can not be formed and the oligomer inhibition property is deteriorated.

Hereinafter, an acrylic urethane copolymer resin (a), a polyester resin (b) having a naphthalene skeleton, an isocyanate compound (c), an oxazoline compound (d) and a melamine compound (e) used in the laminated polyester film of the present invention Will be described.

(1) Acrylic urethane copolymer resin (a)

The acrylic urethane copolymer resin (a) in the laminated polyester film of the present invention is not particularly limited as long as it is a resin in which an acrylic resin and a urethane resin are copolymerized.

The acrylic resin used in the present invention refers to a resin obtained by copolymerizing an acrylic monomer, which will be described later, and, if necessary, various kinds of monomers by a known acrylic resin polymerization method such as emulsion polymerization or suspension polymerization.

Examples of the acrylic monomer for use in the acrylic urethane copolymer resin (a) include alkyl acrylates (methyl, ethyl, n-propyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, , Alkyl methacrylates (examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc .; 2-hydroxyethyl acrylate, Acrylate, methacrylamide, N-methylmethacrylamide, N-methyl acrylamide, N-methylol acrylate, N-methylol acrylamide, Amide, N-methylmethacrylamide, N, N-dimethylol acrylamide, N-methoxymethylacrylamide, N-methoxymethyl methacrylamide, N-butoxymethylacrylamide and N-phenylacrylamide Amide group-containing monomer, N, N-diethyl Amino group-containing monomers such as methyl ethyl ketone, aminoethyl acrylate, N, N-diethylaminoethyl methacrylate, glycidyl group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, acrylic acid, And monomers containing a carboxyl group or a salt thereof such as a salt (sodium salt, potassium salt, ammonium salt and the like).

The acrylic resin is obtained by polymerizing one or two or more kinds of acrylic monomers. When the monomers other than the acrylic monomers are used in combination, the ratio of the acrylic monomers in the total monomers is 50% by weight or more, and more preferably 70% Is preferable from the viewpoint of adhesiveness.

The urethane resin used in the present invention refers to a resin obtained by reacting a polyhydroxy compound and a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization or suspension polymerization.

Examples of the polyhydroxy compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, There may be mentioned, for example, lactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylol propane, trimethylol ethane, pentaerythritol, polycarbonate diol and glycerin .

Examples of the polyisocyanate compound include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, adducts of tolylene diisocyanate and trimethylene propane, adducts of hexamethylene diisocyanate and trimethylolethane Can be used.

When applied to an in-line coating method described later as a method of forming the resin layer (X), the acrylic urethane copolymer resin (a) is preferably dissolved or dispersed in water. As a method for enhancing the affinity of the acrylic urethane copolymer resin with water, for example, a polyhydroxy compound containing a carboxylic acid group or a hydroxyl group-containing carboxylic acid is used as one of the polyhydroxy compounds. As the carboxylic acid group-containing polyhydroxy compound, for example, dimethylolpropionic acid, dimethylolbutyric acid, dimethylolvaleric acid, trimellitic acid bis (ethylene glycol) ester and the like can be used. As the hydroxyl-containing carboxylic acid, for example, 3-hydroxypropionic acid,? -Hydroxybutyric acid, p- (2-hydroxyethyl) benzoic acid, malic acid and the like can be used.

As another method for enhancing the affinity of the acrylic urethane copolymer resin with water, there is a method of introducing a sulfonic acid base into the urethane resin. For example, it is possible to add prepolymers from a polyhydroxy compound, a polyisocyanate compound and a chain extender, add a compound having in its molecule an amino group or a hydroxyl group capable of reacting with a terminal isocyanate group and a sulfonic acid group or a sulfuric acid half ester group, And finally obtaining a urethane resin having a sulfonic acid group or a sulfuric acid half ester base in the molecule. Examples of the compound having an amino group or a hydroxyl group and a sulfonic acid base capable of reacting with a terminal isocyanate group include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 2-amino-5-methylbenzene-2-sulfonic acid, sodium β-hydroxyethanesulfonate , Propanesultone and butane sultone addition product of aliphatic primary amine compounds, and the like, and preferably propane sultone adducts of aliphatic primary amine compounds.

The acryl-urethane copolymer resin (a) is preferably an acrylic-urethane copolymer resin having an acrylic resin as a skin layer and a urethane resin as a core layer because of its excellent adhesion with the hard coat layer. Among them, it is preferable that the core layer including the urethane resin is not completely surrounded by the skin layer including the acrylic resin, but the core layer is exposed. When the core layer is completely wrapped by the skin layer, the resin layer X becomes a surface state having only the characteristics of the acrylic resin, and it becomes difficult to obtain the surface state having the characteristic of the urethane resin originating from the core layer, It is not preferable from the viewpoint of adhesion with the coating layer. On the other hand, a state in which the core layer is not surrounded by the skin layer, that is, a state where the core layer and the core layer are separated is merely a state in which an acrylic resin and a urethane resin are mixed. Then, in general, an acrylic resin having a small surface energy of the resin is selectively coordinated to the air-side surface of the resin layer (X). As a result, the surface of the resin layer (X) is not preferable from the standpoint of adhesion with the hard coat layer because it has only the characteristics of an acrylic resin.

1 shows an example of obtaining an acrylic urethane copolymer resin (a) having a core-skin structure. First, the first stage emulsion polymerization is carried out using a urethane resin monomer, an emulsifier, a polymerization initiator and an aqueous solvent which form a core portion of the polymer resin. Next, after the first stage emulsion polymerization is substantially completed, the acrylic monomer and the polymerization initiator forming the skin portion are added and the second stage emulsion polymerization is carried out. By this two-step reaction, an acrylic urethane copolymer resin having a core-skin structure can be obtained. In order to make the resulting copolymer resin into a two-layer structure of a core layer and a skin structure, an emulsifier is contained in an amount not forming a new core in the second-stage emulsion polymerization, and a urethane resin formed in the first- A method of allowing the polymerization to proceed from the core surface is useful.

The method for producing the acrylic urethane copolymer resin (a) is not limited to those obtained by this method. For example, a small amount of a dispersant and a polymerization initiator are added to an aqueous dispersion of a urethane resin, and the acrylic monomer is slowly added while stirring at a constant temperature. Thereafter, the temperature is elevated as necessary, and the reaction is continued for a predetermined time to complete the polymerization of the acrylic monomer, thereby obtaining an aqueous dispersion of an acrylic urethane copolymer resin.

The content of the acrylic urethane copolymer resin (a) in the coating composition is preferably 3% by weight or more based on the total weight of the resin solid content in the coating composition. When the content of the acrylic urethane copolymer resin (a) is less than 3% by weight, adhesion and suppression of interference fringe can not be achieved at the same time. Is preferably 3% by weight or more and 25% by weight or less, and more preferably 4% by weight or more and 20% by weight or less based on the total weight of the resin solid content in the coating composition. Particularly preferably not less than 5% by weight and not more than 10% by weight.

The glass transition temperature (hereinafter referred to as " Tg ") of the acrylic resin in the acrylic urethane copolymer resin (a) is preferably 20 ° C or higher, more preferably 40 ° C or higher. When the Tg of the acrylic resin is 20 DEG C or more, blocking property at room temperature storage is improved, which is preferable.

The ratio of the acrylic resin to the urethane resin (acrylic resin / urethane resin) in the acrylic urethane copolymer resin (a) is preferably 10/90 to 70/30 by weight, more preferably 20/80 to 50/50 Do. Outside this range, the adhesion between the laminated polyester film and the hard coat layer may be deteriorated. The weight ratio of the acrylic resin and the urethane resin can be adjusted to a desired value by adjusting the amount of the raw material in the production of the acrylic urethane copolymer resin (a).

Further, when the solid content weight ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) in the coating composition is 40/60 to 5/95, the adhesiveness between the laminated polyester film and the hard coat layer becomes good, Do. More preferably 30/70 to 10/90.

(2) a polyester resin having a naphthalene skeleton (b)

The polyester resin (b) having a naphthalene skeleton in the present invention is a resin having a naphthalene skeleton in a polyester resin having an ester bond as a main bonding chain of the main chain.

As a method for obtaining a polyester resin having a naphthalene skeleton, there can be mentioned, for example, a method in which a diol component or a polyhydric hydroxyl group component in which two or more hydroxyl groups are introduced as a substituent in a naphthalene ring, or an ester- There is a method of using the introduced dicarboxylic acid component or polyvalent carboxylic acid component as a polyester resin raw material. From the viewpoint of the stability of the polyester resin, it is preferable to use a dicarboxylic acid component having two carboxylic acid groups in the naphthalene ring as a polyester resin raw material to obtain a polyester resin having a naphthalene skeleton. Examples of the naphthalene skeleton having two carboxylic acid groups include 2,6-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; And ester-forming derivatives of aromatic dicarboxylic acids such as dimethyl 1,4-naphthalenedicarboxylate and dimethyl 1,4-naphthalenedicarboxylate. Among them, ester-forming derivatives of 2,6-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid are particularly preferable in view of refractive index and dispersibility with other resins.

Use of a polyester in which the dicarboxylic acid component having a naphthalene skeleton accounts for at least 30 mol%, more preferably at least 35 mol%, and even more preferably at least 40 mol%, of the total dicarboxylic acid component improves visibility It is preferable.

As the constituent component of the polyester resin (b) containing a naphthalene skeleton, for example, a polyvalent carboxylic acid and a polyhydric hydroxy compound having no naphthalene skeleton may be used in combination. That is, examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4'-diphenylcarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, There may be mentioned phthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, , Trimellitic acid monopotassium salt and ester-forming derivatives thereof. Examples of the polyhydric hydroxy compound include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 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, polytetramethyl There may be mentioned glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylol ethyl sulfonate, potassium dimethylol propionate, and the like.

The polyester resin (b) of the present invention is a copolymerized polyester resin having an aromatic dicarboxylic acid component containing a sulfonic acid metal base in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester desirable. If less than 1 mol%, the polyester resin may not exhibit water solubility, and the compatibility with the acrylic urethane copolymer resin (a), the isocyanate compound (c), and the oxazoline compound (d) The uniformity and the transparency of the ink X may be lowered. On the other hand, if it exceeds 30 mol%, the dispersibility with other resin decreases and transparency, anti-wet heat adhesion and anti-magnetic adhesion tend to deteriorate.

The aromatic dicarboxylic acid component containing a sulfonic acid metal base includes, for example, an alkali metal salt of sulfophthalic acid, an alkali metal salt of sulfoisophthalic acid, an alkali metal salt of sulfoterephthalic acid, an alkaline earth metal salt of sulfophthalic acid, an alkaline salt of sulfoisophthalic acid Alkaline earth metal salts of sulfoterephthalic acid, alkali metal salts of sulfo-2,6-naphthalene dicarboxylic acid, alkali metal salts of sulfo-2,3-naphthalene dicarboxylic acid, sulfo-1,4-naphthalene dicarboxylic acid Alkaline earth metal salts of sulfo-2,6-naphthalene dicarboxylic acid, alkaline earth metal salts of sulfo-2,3-naphthalene dicarboxylic acid, alkaline earth metal salts of sulfo-1,4-naphthalene dicarboxylic acid And a compound having a sulfonic acid base such as a metal salt.

Examples of the aromatic dicarboxylic acid component containing a sulfonic acid metal base other than the above include an alkali metal salt of dimethyl sulfophthalate, an alkali metal salt of dimethyl sulfoisophthalate, an alkali metal salt of dimethyl sulfoterephthalate, an alkali of sulfopropylphthalic acid dimethyl Alkaline earth metal salts of dimethyl sulfo terephthalate, alkali metal salts of dimethyl sulpho-2,6-naphthalenedicarboxylate, sulfates of dimethyl sulfo-2,3-naphthalenedicarboxylate An alkali metal salt of dimethyl sulfo-2,4-naphthalenedicarboxylate, an alkali metal salt of dimethyl sulfo-1,4-naphthalenedicarboxylate, an alkaline earth metal salt of dimethyl sulfo-2,6-naphthalenedicarboxylate, Ester formation of an aromatic dicarboxylic acid having a sulfonic acid group such as earth metal salt and alkaline earth metal salt of dimethyl sulfo-1,4-naphthalenedicarboxylate And salts of derivatives thereof.

Of these, alkali metal salts of sulfoisophthalic acid, alkaline earth metal salts of sulfoisophthalic acid, alkali metal salts and alkaline earth metal salts of ester-forming derivatives of sulfoisophthalic acid are particularly preferable.

Specific examples of the alkali metal salts of dimethyl sulfophthalate include dimethyl sulfoxide 5-sulfophthalate, dimethyl sodium 5-sulfophthalate, dimethyl potassium 5-sulfophthalate and dimethyl cesium 5-sulfophthalate, and the alkali of the dimethyl sulfophthalate Specific examples of the earth metal salt include bis (5-sulfophthalic acid dimethyl) magnesium, bis (5-sulfophthalic acid dimethyl) calcium and bis (5-sulfophthalic acid dimethyl) barium. The same applies to alkali metal salts and alkaline earth metal salts of dimethyl dimethyl sulfo isophthalate and dimethyl sulfoterephthalate although specific examples are omitted.

Further, when the polyester resin (b) in the present invention contains the diol component represented by the following formula (1) as the diol component of the polyester resin, the dispersibility with other resins is improved and the visibility is improved Therefore, it is preferable. Since the following formula (1) has a bisphenol S skeleton having an S element with a high refractive index, the refractive index of the polyester resin (b) can be increased. On the other hand, by using a bisphenol compound including a bisphenol A having a structure similar to that of the formula (1) as a diol component, the dispersibility improving effect and the visibility improving effect with other resins compared with the case of using the diol component represented by the formula (1) Falls.

Here, X ¹ and X ² : - (C _n H _2n O) _m -H n = 2 or more and 4 or less, and m = 1 or more and 15 or less. Here, the oxyalkylene unit constituting X ¹ and X ² has ² to 4 carbon atoms and includes oxyethylene unit, oxypropylene unit, oxybutylene unit and / or oxytetramethylene unit, but oxyethylene unit Units and / or oxypropylene units (n = 2 or 3). The repeating number (m) of the oxyalkylene group is preferably 1 or more and 15 or less, more preferably 1 or more and 4 or less, still more preferably 1 or 2.

The polyester resin (b) in the present invention is preferably a copolymerized polyester resin containing the diol component represented by the formula (1) in an amount of 5 mol% or more and 50 mol% or less with respect to the total diol component of the polyester. And more preferably 10 mol% or more and 40 mol% or less.

The polyester resin (b) preferably contains at least one diol compound represented by the following formula (3) as a diol component other than the formula (1).

(Wherein X ³ : - (C _x H _2x O) _y -, x = 2 or more and 10 or less, y = 1 or more and 4 or less)

Examples of the alkanediol having 2 to 10 carbon atoms (x = 2 to 10) include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,8 1,3-propanediol, 1,4-butanediol (x = 2 or 3) is preferable. The repeating number y of the oxyalkylene group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less. The polyester resin (b) in the present invention is preferably a copolymerized polyester resin containing the diol component represented by the formula (3) in an amount of 5 mol% or more and 50 mol% or less with respect to the total diol component of the polyester. And more preferably 10 mol% or more and 40 mol% or less. Having such an oxyalkylene group is more preferable since the hydrophilicity of the polyester resin (b) can be improved and the dispersibility with other resins can be improved.

The intrinsic viscosity of the polyester resin (b) used in the present invention is not particularly limited, but is preferably 0.3 dl / g or more and 2.0 dl / g or less, more preferably 0.4 dl / g or more and 1.0 dl / g or less More preferable. The intrinsic viscosity in the present invention is a value obtained by dissolving 0.3 g of a polyester resin in 25 ml of a mixed solvent of phenol / tetrachloroethane = 40/60 (weight ratio) and measuring at 35 ° C using a Canon fescue viscometer.

The polyester resin (b) according to the present invention preferably has a refractive index of 1.58 or more, preferably 1.61 or more and 1.65 or less. In the present invention, the refractive index is a value measured at 25 캜 using an Abbe's refractometer by molding a polyester resin into a resin plate having a thickness of 0.5 mm using a mini hot press. For the measurement, monobromonaphthalene is used as an intermediate liquid.

In the laminated polyester film of the present invention, the polyester resin (b) can be produced by the following production method. For example, a mixture of dimethyl naphthalenedicarboxylate as a dicarboxylic acid component having a naphthalene skeleton and dimethyl sodium 5-sulfoisophthalate as an aromatic dicarboxylic acid component containing a sulfonic acid metal base, (2) and ethylene glycol as a diol component represented by the formula (3) are transesterified in the presence of a known polymerization catalyst, and then subjected to a transesterification reaction at a high temperature and a high vacuum A method of producing by a transesterification-polycondensation reaction in which a low molecular weight compound is distilled off and subjected to a polycondensation reaction; a method in which dimethyl naphthalenedicarboxylate as a dicarboxylic acid component having a naphthalene skeleton and an aromatic dicarboxylic acid containing a sulfonic acid metal base , Sodium dimethyl 5-sulfoisophthalate as an acid component, and sodium bisulfite as a diol component represented by the formula (1) A compound obtained by adding 2 moles of ethylene oxide to 1 mole of phenol S and ethylene glycol as a diol component represented by the formula (3) are transesterified in the presence of a known polymerization catalyst, and then a low molecular weight compound Polycondensation-depolymerization reaction in which a polycondensation reaction and a depolymerization reaction are carried out while distillation is removed, a method in which dimethyl naphthalenedicarboxylate as a dicarboxylic acid component having a naphthalene skeleton and an aromatic dicarboxylic acid containing a sulfonic acid metal base A compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S as a diol component represented by the formula (1), and a diol represented by the formula (3) Ethylene glycol as a component is obtained by distillation of a low molecular weight compound under high temperature and high vacuum in the presence of a known polymerization catalyst And a method of producing by a polycondensation reaction.

At this time, for example, alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like can be used as reaction catalysts.

The Tg of the polyester resin (b) is preferably 0 deg. C or more and 130 deg. C or less, and more preferably 10 to 85 deg. When the Tg is less than 0 ° C, for example, the anti-wet heat adhesive property and the anti-magnetic adhesion are deteriorated or the blocking phenomenon occurs in which the resin layers X are fixed to each other. On the contrary, when the Tg is higher than 130 ° C, Which is not preferable.

(3) Isocyanate Compound (c)

The isocyanate compound (c) in the present invention means a compound containing a structure derived from the following isocyanate compound (c) or the following isocyanate compound (c).

Examples of the isocyanate compound (c) include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, methacrylsilane diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, Adducts of dicyclohexylmethane diisocyanate and hexanetriol adducts, adducts of tolylene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, Isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-bitolylene-4,4'diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, Can be used. Particularly, when a polymeric isocyanate compound having a plurality of isocyanate groups at the terminals or side chains of a polymer such as polyester resin or acrylic resin is used, the layer (X) can be preferably used because it has high toughness.

When applied to an in-line coating method described later as a method of forming the resin layer (X), the isocyanate compound (c) is preferably water-dispersed. Particularly, a block isocyanate compound in which an isocyanate group is masked with a block agent or the like is particularly preferable from the viewpoint of the time of use of the coating composition. As a cross-linking reaction of a block agent, a system is known in which the block agent is volatilized by heat in a drying step after application, the isocyanate group is exposed, and a cross-linking reaction is caused. The isocyanate group may be either a monofunctional or polyfunctional type. However, the cross-linking density of the layer (X) of the block polyisocyanate compound of the polyfunctional type is improved and the anti-wet heat adhesion property with the hard coat layer, It is preferable because it has excellent properties.

Examples of the low molecular weight or high molecular compound having two or more block isocyanate groups include tolylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate 3 mole adduct of trimethylolpropane, polyvinylisocyanate, vinylisocyanate copolymer, polyurethane terminal diisocyanate , A methyl ethyl ketone oxime block material of tolylene diisocyanate, a sodium hypochlorite block material of hexamethylene diisocyanate, a methyl ethyl ketone oxime block material of polyurethane end diisocyanate, and a phenol adduct of 3 mol of tolylene diisocyanate trimethylol propane Block bodies or the like can be used.

(C) is preferably not less than 3 parts by weight and not more than 20 parts by weight, more preferably not more than 20 parts by weight, based on 100 parts by weight of the total of the acrylic urethane copolymer resin (a) and the polyester resin (b) Is not less than 4 parts by weight and not more than 18 parts by weight, more preferably not less than 5 parts by weight and not more than 16 parts by weight.

When the content of the isocyanate compound (c) is within the above range and the total content of the oxazoline compound (d) is within a predetermined range, the resin layer X is excellent in transparency, wet heat adhesion, Visibility can be expressed. When the content of the isocyanate compound (c) in the coating composition is less than 3 parts by weight, adhesion with the hard coat layer is poor. On the other hand, when the amount exceeds 20 parts by weight, the transparency of the laminated polyester film is deteriorated, the refractive index of the resin layer is lowered, and the visibility is poor when the hard coat layer is laminated.

(4) Oxazoline compound (d)

The oxazoline compound (d) in the present invention is not particularly limited as long as it has at least one oxazoline group or an oxazole group per molecule. However, the addition-polymerizable oxazoline group-containing monomer may be used alone or in combination with other monomers Polymer forms polymerized together are preferred. When the layer (X) of the present invention is formed on a thermoplastic resin film by using a polymer type oxazoline compound to improve the flexibility, toughness, water resistance, and solvent resistance of the layer (X) .

Examples of the addition polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2- 2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline and 2-isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination of two or more. Of these, 2-isopropenyl-2-oxazoline is industrially easily available and is suitable. The other monomer is not particularly limited as long as it is a monomer copolymerizable with the addition polymerizable oxazoline group-containing monomer, and examples thereof include alkyl acrylate, alkyl methacrylate (examples of the alkyl group include a methyl group, ethyl group, n-propyl group, isopropyl group, (Meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, Unsaturated carboxylic acids such as salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt and the like), unsaturated nitriles such as acrylonitrile and methacrylonitrile; Acrylamide, N, N-dialkyl methacrylate (the alkyl group includes methyl, ethyl, n-propyl, isopropyl, Unsaturated amides such as isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl and cyclohexyl groups; vinyl esters such as vinyl acetate, vinyl propionate, acrylic acid and methacrylic acid; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether;? -Olefins such as ethylene and propylene; halogen such as vinyl chloride, vinylidene chloride and vinyl fluoride; And?,? - unsaturated aromatic monomers such as α, β-unsaturated monomers, styrene, and α-methylstyrene, and the like. One or more of these monomers may be used.

The content of the oxazoline compound (d) is preferably 20 to 50 parts by weight based on 100 parts by weight of the content of (a) and (b) in the coating composition. When the resin layer (X) of the present invention is formed on the polyester film in the range of 20 to 50 parts by weight, when the laminated polyester film is used, it has a high resistance to moisture and heat and heat, an excellent UV adhesive property, A laminated polyester film can be imparted.

(5) Melamine compound (e)

The resin layer (X) of the present invention may also be a layer formed using a coating composition containing a melamine compound (e).

The melamine compound (e) is not particularly limited, but a methylol melamine derivative obtained by condensing melamine and formaldehyde from the viewpoint of hydrophilization may be subjected to a dehydration condensation reaction such as methyl alcohol, ethyl alcohol or isopropyl alcohol as a lower alcohol, And one compound.

Methylol melamine derivatives include, for example, monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine.

The layer formed by using the coating composition containing the melamine compound (e) in the resin layer (X) of the present invention is preferable because adhesion can be improved, but if the coating composition contains a large amount of melamine compound, There arises a problem that process contamination due to volatilization of the melamine compound becomes a problem or that the melamine compound generates formaldehyde which is harmful to the human body by the crosslinking reaction. Therefore, it is preferable that the content of the melamine compound (e) is 30 parts by weight or less when the content of (a) and (b) in the coating composition is 100 parts by weight. More preferably 5 parts by weight or more and 30 parts by weight or less, and particularly preferably 10 parts by weight or more and 25 parts by weight or less.

When the melamine compound (e) is used in an amount of not less than 5 parts by weight and not more than 30 parts by weight, the layer (X) of the present invention is formed on a polyester film, and when the laminated polyester film is used, Can be made better.

(6) Method of forming the resin layer (X)

The resin layer (X) in the present invention is obtained by mixing the above-mentioned acrylic urethane copolymer resin (a), the polyester resin (b), the isocyanate compound (c), the oxazoline compound (d). < / RTI > (A), a polyester resin (b), an isocyanate compound (c), an oxazoline compound (d), and at least one component selected from the group consisting of a polyester resin Means that a coating composition comprising a mixture containing the melamine compound (e) is formed into a layer shape on the base film and is cured or crosslinked if necessary. Specifically, the acrylic urethane copolymer resin (a), the polyester resin (b), the isocyanate compound (c), the oxazoline compound (d) and, if necessary, the melamine compound (e) Or a surfactant may be coated on the polyester film, and if necessary, the solvent may be dried and, if necessary, cured or crosslinked to form the resin layer (X) on the polyester film.

Further, in the present invention, it is preferable to use an aqueous solvent (f) as a solvent. By using an aqueous solvent, the solvent in the drying step can inhibit rapid evaporation and can form a uniform resin layer (X), and is excellent in terms of environmental load.

Here, the water-based solvent (f) is water or an alcohol such as methanol, ethanol, isopropyl alcohol or butanol, ketones such as acetone or methyl ethyl ketone, glycols such as ethylene glycol, diethylene glycol or propylene glycol And that organic solvent soluble in water is mixed at an arbitrary ratio. By using an aqueous solvent, rapid evaporation of the solvent in the drying step can be suppressed, and a uniform resin layer can be formed. It is also excellent in terms of environmental load.

The coating method of the coating composition on the polyester film can be used either in the in-line coating method or the off-coating method, but is preferably the in-line coating method.

The in-line coating method is a method of performing coating in a production process of a polyester film. Specifically, it refers to a method in which the polyester resin is melt-extruded, followed by biaxial stretching, followed by heat treatment, and then the film is wound up at an arbitrary step until the film is rolled up. Usually, the film is subjected to a substantially quasi-non- (Uniaxially oriented) polyester film (hereinafter referred to as " B film ") or a further stretched film in the transverse direction (Biaxially oriented) polyester film (hereinafter referred to as " C film ") before heat treatment.

In the present invention, the coating composition is applied to any one of the A film, the B film, and the C film before the crystal orientation is completed, and then the polyester film is uniaxially or biaxially stretched, Is subjected to a heat treatment at a temperature higher than the boiling point of the polyester film to complete the crystal orientation of the polyester film and to form the resin layer (X). According to this method, the film formation of the polyester film and the application and drying of the coating composition (that is, the formation of the resin layer (X)) can be carried out at the same time. Further, it is easy to make the thickness of the resin layer X thinner in order to perform stretching after application. The thickness of the resin layer X is preferably from 50 nm to 200 nm, more preferably from 60 nm to 150 nm, and still more preferably from 70 nm to 130 nm, which is capable of canceling optical interference from the viewpoint of visibility.

Among them, the method of applying a coating composition to a uniaxially stretched film (B film) in the longitudinal direction and then stretching it in the width direction and then subjecting it to heat treatment was excellent. Compared with the biaxial stretching method after coating on the unstretched film, defects and cracks of the resin layer (X) due to stretching are less likely to occur due to a small number of stretching steps, and the resin layer (X) having excellent transparency and smoothness As shown in FIG.

On the other hand, the offline coating method refers to a method in which the film A is stretched uniaxially or biaxially and subjected to a heat treatment to complete the crystal orientation of the polyester film, or to a film A by a process different from the film- .

In the present invention, it is preferable that the resin layer (X) is formed by the in-line coating method from the above-mentioned various advantages.

Therefore, a preferred method for forming the resin layer (X) in the present invention is a method in which a water-based coating composition using an aqueous solvent (f) is applied on a polyester film using an inline coating method and dried. More preferably, the coating composition is in-line coated on the uniaxially stretched B film. Also, the solid content concentration of the coating composition in the coating liquid is preferably 5% by weight or less. By setting the solid concentration to 5% or less, it is possible to produce a laminated polyester film which can impart good coating properties to the coating composition and has a transparent and homogeneous resin layer.

(7) Process for producing a coating liquid containing a coating composition using an aqueous solvent (f)

The coating composition using the water-based solvent (f) may contain, if necessary, water-soluble or water-soluble acrylic urethane copolymer resin (a), polyester resin (b), isocyanate compound (c), oxazoline compound And water-based solvent (f) in any order in a desired solid content weight ratio.

Subsequently, the melamine compound (e) may be added to the coating composition in any order in a desired solid content weight ratio, if necessary, followed by stirring.

For mixing and stirring, the container may be shaken by hand, or a magnetic stir bar, stirring blade, ultrasonic wave irradiation, vibration dispersion, or the like may be performed.

If necessary, various additives such as lubricants, inorganic particles, organic particles, surfactants, and antioxidants may be added to the extent that the properties of the resin layer formed by the coating composition do not deteriorate.

(8) Coating method

The application method of the coating composition to the polyester film may be any known coating method such as a bar coating method, a reverse coating method, a gravure coating method, a die coating method and a blade coating method.

(9) Method for producing laminated polyester film

Next, the method of producing the laminated polyester film of the present invention will be described by taking as an example the case where a polyethylene terephthalate (hereinafter abbreviated as PET) film is used as the polyester film, but the invention is not limited thereto. First, the PET pellets are thoroughly vacuum-dried and then fed to an extruder. The PET pellets are melt-extruded at about 280 ° C in a sheet form, cooled and solidified to produce an unstretched (unoriented) PET film (A film). The film is stretched 2.5 to 5.0 times in the longitudinal direction by a roll heated at 80 to 120 占 폚 to obtain a uniaxially oriented PET film (B film). The coating composition of the present invention prepared at a predetermined concentration is applied to one side of the B film. At this time, a surface treatment such as a corona discharge treatment may be performed on the coated surface of the PET film before application. It is possible to improve the wettability of the coating composition to the PET film, prevent the coating composition from being cratered, and achieve a uniform coating thickness by performing surface treatment such as corona discharge treatment.

After the application, the end of the PET film is gripped with a clip and is led to a heat treatment zone (preheating zone) at 80 to 130 캜 to dry the solvent of the coating composition. And then stretched by 1.1 to 5.0 times in the width direction after drying. Subsequently, the film is led to a heat treatment zone (heat-setting zone) at 160 to 240 ° C and heat treatment is performed for 1 to 30 seconds to complete crystal orientation.

In this heat treatment step (heat fixing step), a relaxation treatment of 3 to 15% in the width direction or the longitudinal direction may be carried out if necessary. The thus-obtained laminated polyester film is a laminated polyester film which is excellent in transparency and adhesiveness to a hard coating layer, anti-wet heat adhesion, anti-magnetic adhesion, and visibility when a hard coating layer is laminated.

[Method of measuring characteristics and evaluation method of effect]

(1) Evaluation method of transparency

The transparency was evaluated by the initial haze (%). The haze was measured using a turbidity meter "NDH5000" manufactured by Nippon Denshoku Kogyo Co., Ltd. after the laminated polyester film was left in the state (temperature 23 ° C, relative humidity 65%) for 1 hour. The average value measured three times was regarded as the initial haze of the laminated polyester film. Transparency was evaluated in four steps according to the value of haze. C is a level with practical problems, B is a practical level, and S and A are good.

S: Less than 1.0%

A: 1.0% or more and less than 2.0%

B: 2.0% or more and less than 3.0%

C: More than 3.0%.

(2) Evaluation method of adhesion to hard coat layer

(2-1) Evaluation method of initial adhesion property

The UV cured resin mixed in the following ratio on the surface of the resin layer (X) of the laminated polyester film was uniformly coated using a bar coater so that the cured UV cured resin layer had a thickness of 2 탆.

Dipentaerythritol hexaacrylate: 60 parts by weight

(Kaya Rad (registered trademark) DPHA, manufactured by Nippon Kayaku Co., Ltd.)

Pentaerythritol triacrylate: 40 parts by weight

("KAYA RAD" (registered trademark) PETA manufactured by Nippon Kayaku Co., Ltd.)

Photopolymerization initiator ("Irgacure" (registered trademark) 184 manufactured by Nagaseishan Co., Ltd.): 3 parts by weight

Methyl ethyl ketone: 100 parts by weight

Subsequently, the total irradiation intensity was set to 300 mJ / cm ² with a condensing type high-pressure mercury lamp (H03-L31 manufactured by Eye Graphics Co., Ltd.) having an irradiation intensity of 120 W / cm set at a height of 9 cm from the surface of the UV cured resin layer Ultraviolet rays were irradiated and cured to obtain a hard coat laminated polyester film in which a hard coat layer was laminated on the laminated polyester film. Obtained into the 100 cross cuts 1mm ² of the hard coat laminate surface of hard coat laminated polyester film, attaching a cellophane tape (registered trademark) (Mannich half (Co., Ltd.) CT405AP) and, 1.5kg / cm ² with a hand roller , And then rapidly peeled off in the direction of 90 degrees to the hard coat laminated polyester film. Adhesiveness was evaluated in four stages by the number of remaining crosscuts. The number of remaining crosscuts was determined to be an average value obtained three times. C is a level with practical problems, B is a practical level, and S and A are good.

S: 100 remaining

A: 80 to 99 remaining

B: 50 to 79 remaining

C: Less than 0 to less than 50 residues.

(2-2) Evaluation method of adhesion resistance in wet heat

A hard-coated laminated polyester film was obtained in the same manner as in (2-1). The resultant hard-coated laminated polyester film was allowed to stand for 240 hours in a constant-temperature and constant-humidity bath at a temperature of 85 캜 and a relative humidity of 85%, and then dried in a state (23 캜, relative humidity 65%) for 1 hour, A sample was obtained. The obtained hard-coating laminate sample for wet adhesion test was subjected to adhesion evaluation in the same manner as in (2-1), and evaluated in four steps. The number of remaining crosscuts was determined to be an average value obtained three times. C is a level with practical problems, B is a practical level, and S and A are good.

(2-3) Evaluation method of self-adhesive property

The UV cured resin was applied to the surface of the resin layer of the laminated polyester film in the same manner as in the evaluation of (2-1) and cured to obtain an evaluation sample for adhesion of masticity. Next, the sample for evaluation of adhesion to the masticatory adhesive was cut to a size of 10 cm x 10 cm, each of the samples was fixed on a clip to be in a suspended state, and then the whole surface of the laminated polyester film was immersed in a boiling water (100 DEG C) Was put in the soaking state for 18 hours. Thereafter, the sample for evaluation of mabi-adhesive adhesion was dried for 1 hour in a take-out state (23 ° C, relative humidity 65%) to obtain a hard-coated laminated sample for mabi adhesion test. The obtained hard-coating laminate sample for adhesion resistance evaluation was subjected to adhesion evaluation in the same manner as in (2-1), and evaluated in four steps. The number of remaining crosscuts was determined to be an average value obtained three times. C is a level with practical problems, B is a practical level, and S and A are good.

(2-4) Evaluation method of UV adhesive property

The UV cured resin was applied to the surface of the resin layer (X) of the laminated polyester film in the same manner as in the evaluation of (2-1) and cured to obtain a sample for UV-adhesive test. Thereafter, as in (2-1), ultraviolet rays were irradiated so that the total irradiation intensity was 500 mJ / cm ² , and the procedure was repeated three times in total until the total irradiation intensity became 1500 mJ / cm ² . The obtained hard coat layered sample for UV adhesion test was subjected to adhesion evaluation in the same manner as in (2-1), and evaluated in four steps. C is a level with practical problems, B is a practical level, and S and A are good.

(3) Evaluation method of thermal water resistance

The heat-resistant water-transparency was evaluated by the haze change amount (? Hz) (%) before and after immersing the laminated polyester film in hot water. The laminated polyester film was cut into a size of 10 cm x 10 cm and fixed to a clip to make it stand still. Then, the entire surface of the laminated polyester film was immersed in a boiling water (100 DEG C) containing pure water prepared in a beaker 1 hour. Thereafter, the laminated polyester film was taken out and dried in a state (23 DEG C, relative humidity 65%) for 1 hour to obtain a sample for heat water resistance transparency test. Here, in the case of the sample having the resin layer (X) on only one side of the polyester film, the side of the polyester film opposite to the resin layer was treated with a nonwoven fabric containing acetone (manufactured by Ozagan Kogyo Co., ), And the film was allowed to stand for one hour in a normal state, and the oligomer precipitated from the surface of the polyester film opposite to the resin layer was removed to obtain a sample for heat water resistance transparency test.

Transparency was evaluated in the same manner as in (1) for the obtained hot water water resistance test sample, and the obtained value was defined as haze (%) after the mercury-free test. The value obtained by subtracting the haze (%) (initial haze) before the mercury-free test process from this value was used as the film haze change amount? Hz (? Hz = haze after the mercury-free test process- And a four-step evaluation was carried out. C is a level with practical problems, B is a practical level, and S and A are good.

S: less than 3.0%

A: 3.0% or more and less than 5.0%

B: 5.0% or more and less than 6.0%

C: 6.0% or more.

(4) Evaluation method of visibility (interference stripes)

(2-1), a hard coating film having a hard coat layer of 2 탆 in thickness laminated on the laminated polyester film was obtained. Subsequently, a sample having a size of 8 cm (in the hard coating film width direction) × 10 cm (in the hard coating film length direction) was cut out from the obtained hard coating film, and a black glossy tape (vinyl tape No.200-50-21: Black) was attached so as not to include air bubbles.

The sample was placed in a dark room at 30 cm directly under a three-wavelength fluorescent lamp (3-wavelength type main white (F · L 15EX-N 15W) manufactured by Matsushita Electric Industries, Ltd.), and the degree of interference non- , And the following evaluations were carried out. A or higher was evaluated as good.

S: Interference roughly invisible

A: A little disturbance of interference is seen.

B: Weak interference is visible

C: Strong interference uniformity.

(5) Evaluation method of film thickness of resin layer (X)

A laminated polyester film was prepared by a RuO ₄ -discriminated thin film slicing method. The cross section of the obtained sample was observed using a transmission electron microscope (TEM) to measure the thickness of the resin layer (X) on the laminated polyester film. The thickness of the resin layer (X) was read from the image taken at a magnification of 200,000 times by TEM. The thickness of the resin layer was measured at 20 points, and the average value was defined as the film thickness (nm) of the resin layer (X).

Measurement apparatus: transmission electron microscope (H-7100FA type manufactured by Hitachi).

(6) Evaluation method of spectral reflectance

The film sheet cut in the A4 cut size was divided into three parts in the vertical and horizontal directions, and a total of nine pieces were used as measurement samples. And the long side was the longitudinal direction. The measurement of the spectral reflectance was carried out in such a manner that a 50 mm wide black glossy tape (vinyl tape No. 200-50-21: black, manufactured by Yamato Co., Ltd.) of 50 mm in width was placed on the back surface of the measurement surface The tape was bonded in the longitudinal direction, cut into 4 cm square pieces, and the spectral reflectance at an incident angle of 5 DEG was measured with a spectrophotometer (UV2450 manufactured by Shimadzu Corporation). The direction in which the sample was set on the measuring device was the longitudinal direction of the sample in the forward and backward directions toward the front of the measuring device. The standard Al ₂ O ₃ plate was used as a standard reflector in order to standardize the reflectance. The spectral reflectance of the surface side having the resin layer X is measured for a wavelength range of 450 nm to 650 nm and the minimum value (%) of the spectral reflectance in the wavelength range of 450 nm to 650 nm at the side of the resin layer (X) Respectively. The measurement was performed on 9 pieces of sample pieces cut out at 4 cm square, and the average value of 9 points was obtained.

(7) Evaluation method of dispersion index (determination by cross-sectional photograph of transmission electron microscope (TEM))

A sample of the surface of the resin layer (X) is prepared on the laminated polyester film by the RuO ₄ -discriminated thin film cutting method. A sectional photograph of the obtained sample was obtained by using a transmission electron microscope (TEM) under the following conditions. The number of agglomerates including the acrylic urethane copolymer resin (a) having a size of 40 nm or more observed in the visual field area (Z direction x direction: 500 nm x 1200 nm) in the obtained cross-sectional photograph was observed, (120000 nm ² ) according to the following expression.

(Number of agglomerates having an observed size of 40 nm or more) x 120000 / area occupied by the resin layer (X) in the visual field area

The observation was carried out for 10 fields and the number of first decimal places of the average number of aggregates observed per a predetermined area was rounded off to obtain a dispersion index. The dispersion index represents an integer of 0 or more. In the present invention, the dispersion index of 5 or less is considered good.

Measurement apparatus: transmission electron microscope (Model H-7100FA manufactured by Hitachi Ltd.)

Measurement conditions: Acceleration voltage (100 kV)

· Magnification: 20,000 times.

(8) Evaluation method of change amount? R of spectral reflectance before and after the self-abrasion treatment test

The spectral reflectance (%) before the mercury treatment test was measured in the same manner as in the method described in the evaluation method of spectral reflectance (6), and the spectral reflectance was measured for the wavelength range of 400 nm to 800 nm on the side of the resin layer (X) Respectively.

The spectral reflectance (%) after the mercury treatment test was obtained by the following method. Namely, the laminated polyester film was cut into 9 cm × 10 cm × 10 cm pieces, fixed to a clip and suspended, and then the entire surface of the laminated polyester film was immersed in a boiling water (100 ° C.) containing pure water prepared in a beaker And the mixture was immersed in water for 5 hours. Thereafter, the laminated polyester film was taken out and dried in a normal state (23 캜, relative humidity 65%) for 1 hour to obtain a sample for spectral reflectance measurement after the self-treatment treatment test.

A 50-mm-thick black glossy tape (vinyl tape No. 200-50-21: black, manufactured by Yamato) was applied to the back surface of the measurement surface (the resin layer (X)) to the sample for measurement of spectral reflectance after the obtained self- The sample was cut into 4 cm square sample pieces, and the spectral reflectance was measured with a spectrophotometer (UV2450 manufactured by Shimadzu Corporation) at an incident angle of 5 DEG to a wavelength range of 400 nm to 800 nm . The average value of the wavelength range of 400 nm or more and 800 nm or less was taken as the average value of 9 sample pieces cut out at 4 cm square as the spectral reflectance (%) after the self-treatment treatment test.

The absolute value of the value obtained by subtracting the average value (%) of the spectral reflectance after the self-bias test treatment from the average spectral reflectance (%) before the self-bias treatment test obtained above is referred to as a change amount? R of the spectral reflectance before and after the self- The spectral reflectance - the spectral reflectance after the self-test (|) (%). The change amount? R of the spectral reflectance before and after the mercury treatment test was 0% or more and 2% or less.

(9) Evaluation of heat treatment (ΔHz after heating)

A laminated film sample was fixed on four sides of a metal frame and a sample fixed to a metal frame was placed in a hot air oven " HIGH-TEMP-OVEN PHH-200 " manufactured by Espec Co., Ltd., Heated up for 1 hour, and then allowed to stand at room temperature for 1 hour. Here, in the laminated film sample in which the resin layer was formed only on one side of the polyester film, the surface of the polyester film on the opposite side to the resin layer was treated with a nonwoven fabric (Hijase Kagaku NT-4, manufactured by Ozagan Kogyo Co., Ltd.) Washed with acetone, left to stand still under normal conditions for 40 hours, and the oligomer precipitated from the surface of the polyester film opposite to the resin layer was removed. Thereafter, the haze value of the sample after heating was measured by the initial haze evaluation method described in the above (1), and the difference in haze value of one side of the resin layer before and after the heat treatment was evaluated as ΔHz value after heating. The sample of the laminated film having the resin layer formed on both sides of the polyester film was heated in a hot air oven and allowed to stand in a normal state for 40 hours. The haze value after heating was measured by the initial haze evaluation method described in the above (1) , And the value obtained by dividing the difference in haze value before and after the heating treatment by half (50%) was regarded as the difference in haze value of the resin layer side, and this was evaluated as ΔHz value after heating. The average value measured 10 times in total was defined as the haze value of the sample.

≪ DELTA Hz value after heating &

S: less than 2.0%

A: 2.0% or more and less than 2.5%

B: 2.5% or more and less than 3.0%

C: 3.0% or more

The evaluation of the heat treatment was made to be A or better.

(10) Measurement of surface zeta potential of resin layer (X)

First, the laminated polyester film was sampled at a size of 3 cm x 1 cm in accordance with the size of the solid surface zeta potential measuring cell, and a zeta potential was measured by a zeta potential meter (manufactured by Otsuka Denshi Co., Ltd.) so that the measurement surface was the resin layer (Refractive index: 1.3328, viscosity: 0.8878 (cP), dielectric constant: 78.3) as a solvent, and the measurement was carried out by using the equation of Smoluchowski Three mean values of the calculated values were used as values of the zeta potential.

Example

The present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.

A reference example also shows a method of synthesizing an acrylic urethane copolymer resin and a polyester resin having a naphthalene skeleton.

(Reference Example 1)

Preparation of an aqueous dispersion of the acrylic urethane copolymer resin (a-1)

66 parts by weight of a polyester-based urethane resin ("Hydran" (registered trademark) AP-40 (F) manufactured by DIC Corporation) and 35 parts by weight of methyl methacrylate were added to a vessel 1 under a nitrogen gas atmosphere at room temperature , 29 parts by weight of ethyl acrylate and 2 parts by weight of N-methylol acrylamide were added to obtain Solution 1. Subsequently, 7 parts by weight of an emulsifier ("Rear Thorpe" ER-30 manufactured by ADEKA INC.) Was added, and water was added so that the solid content of the solution became 50% by weight to obtain Solution 2. 30 parts by weight of water was added to vessel 2 at room temperature (25 占 폚), and the temperature was raised to 60 占 폚. Then, Solution 2 was continuously dripped into Container 2 over 3 hours while stirring. Simultaneously, 3 parts by weight of a 5 wt% aqueous solution of potassium persulfate was added dropwise to the vessel 2. After completion of the dropwise addition, the mixture was further stirred for 2 hours and then cooled to 25 ° C to terminate the reaction to obtain an acrylic urethane copolymer resin (a-1) water dispersion. The solid content concentration of the obtained acrylic urethane copolymer resin (a-1) water dispersion was 30% by weight.

In the following Reference Examples 2 to 13, the composition ratio of the dicarboxylic acid component and the diol component is a value obtained by setting the total dicarboxylic acid component and the total diol component at 100 mol%. In Reference Examples 2 to 13, the molar ratio of the total dicarboxylic acid component to the total diol component was 1: 1.

(Reference Example 2)

Preparation of an aqueous dispersion of a polyester resin (b-1) having a naphthalene skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 88 mol%

5-dimethylsodium sulfoisophthalate: 12 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

1,3-Propanediol: 14 mole%.

(Reference Example 3)

Production of an aqueous dispersion of a polyester resin (b-2) having a naphthalene skeleton and an aromatic dicarboxylic acid component containing a sulfonic acid metal base

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 99 mol%

5-dimethylsodium sulfoisophthalate: 1 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

1,3-Propanediol: 14 mole%.

(Reference Example 4)

Production of an aqueous dispersion of a polyester resin (b-3) having a naphthalene skeleton and an aromatic dicarboxylic acid component containing a sulfonic acid metal base

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 85 mol%

5-dimethylsodium sulfoisophthalate: 15 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

1,3-Propanediol: 14 mole%.

(Reference Example 5)

Production of an aqueous dispersion of a polyester resin (b-4) having a naphthalene skeleton and an aromatic dicarboxylic acid component containing a sulfonic acid metal base

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid: 85 mol%

5-dimethylsodium sulfoisophthalate: 15 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

1,3-Propanediol: 14 mole%.

(Reference Example 6)

Production of an aqueous dispersion of a polyester resin (b-5) having a naphthalene skeleton and an aromatic dicarboxylic acid component containing a sulfonic acid metal base

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 65 mol%

5-dimethylsodium sulfoisophthalate: 35 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

1,8-Octanediol: 14 mole%.

(Reference Example 7)

Production of an aqueous dispersion of a polyester resin (b-6) having a naphthalene skeleton and no aromatic dicarboxylic acid component containing a sulfonic acid metal base

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 88 mol%

Trimellitic acid: 12 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

Ethylene glycol: 14 mole%.

(Reference Example 8)

Production of an aqueous dispersion of a polyester resin (b-7) having a naphthalene skeleton and having a bisphenol S skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 88 mol%

5-dimethylsodium sulfoisophthalate: 12 mol%

(Diol component)

Compound obtained by adding 2 moles of propylene oxide to 1 mole of bisphenol S: 86 mol%

Ethylene glycol: 14 mole%.

(Reference Example 9)

Production of an aqueous dispersion of an ester resin (b-8) having a naphthalene skeleton and having a bisphenol S skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 88 mol%

5-dimethylsodium sulfoisophthalate: 12 mol%

(Diol component)

A compound obtained by adding 10 moles of propylene oxide to 1 mole of bisphenol S: 50 mole%

Ethylene glycol: 50 mole%.

(Reference Example 10)

Production of an aqueous dispersion of a polyester resin (b-9) having a naphthalene skeleton and having a bisphenol A skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 85 mol%

Dimethyl lithium 5-sulfoisophthalate: 15 mol%

(Diol component) A compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol A: 86 mole%

Ethylene glycol: 14 mole%.

(Reference Example 11)

Production of an aqueous dispersion of a polyester resin (b-10) having a naphthalene skeleton and having a bisphenol A skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

2,6-naphthalene dicarboxylic acid dimethyl: 85 mol%

5-dimethylsodium sulfoisophthalate: 15 mol%

(Diol component)

A compound obtained by adding 10 moles of propylene oxide to 1 mole of bisphenol: 86 mole%

Ethylene glycol: 14 mole%.

(Reference Example 12)

Preparation of an aqueous dispersion of a polyester resin (b-11) having no naphthalene skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

Isophthalic acid: 88 mol%

5-dimethylsodium sulfoisophthalate: 12 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

Ethylene glycol: 14 mole%.

(Reference Example 13)

Preparation of an aqueous dispersion of a polyester resin (b-12) having no naphthalene skeleton

A polyester resin aqueous dispersion containing the following copolymerization composition

≪ Copolymerization component &

(Dicarboxylic acid component)

Terephthalic acid: 88 mol%

5-dimethylsodium sulfoisophthalate: 12 mol%

(Diol component)

Compound obtained by adding 2 moles of ethylene oxide to 1 mole of bisphenol S: 86 mol%

Ethylene glycol: 14 mole%.

(Example 1)

The coating composition was prepared as follows.

Water dispersion of acrylic urethane copolymer resin (a): "Sanaron" WG-658 (solid content concentration 30% by weight) manufactured by Sankan Kosei Kagaku Co.,

Water dispersion of polyester resin (b): polyester resin (b-1) (solid concentration: 15% by weight)

"Elastron" (registered trademark) E-37 (solid concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was used as the water dispersion of the isocyanate compound (c)

Water dispersion of oxazoline compound (d-1): "Epochros" WS-500 (solid concentration: 40% by weight) manufactured by Nippon Shokubai Co.,

Aqueous solvent (f): pure water

(A) / (d) = 15/85/10/40 as the solid content weight ratio and the solid content concentration of the coating composition was 8.5 wt% (F) were mixed to adjust the concentration. The resin composition in the coating composition at this time is shown in Table 1-1.

Subsequently, PET pellets (intrinsic viscosity: 0.63 dl / g) substantially free from particles were thoroughly vacuum-dried and then fed to an extruder and melted at 285 DEG C and extruded from the T- Was wound on a mirror casting drum having a surface temperature of 25 占 폚 and cooled and solidified. The unstretched film was heated at 90 DEG C and stretched 3.4 times in the longitudinal direction to obtain a uniaxially stretched film (B film). This film was subjected to corona discharge treatment in air.

Next, the coating composition whose concentration was adjusted to the aqueous solvent was applied to the corona discharge treated surface of the uniaxially stretched film by bar coating. Both ends in the width direction of the uniaxially stretched film coated with the coating composition adjusted in concentration with an aqueous solvent were gripped with clips and guided to a preheating zone, and the atmosphere temperature was set to 75 캜. Thereafter, the atmosphere temperature was elevated to 110 Deg.] C, the atmosphere temperature was adjusted to 90 deg. C, and the concentration of the coating composition was adjusted with an aqueous solvent was dried to form a resin layer (X). Subsequently, the laminate was successively stretched 3.5 times in the width direction in a heating zone (stretching zone) at 120 ° C, followed by heat treatment in a heat treatment zone (heat fixing zone) at 230 ° C for 20 seconds to obtain a laminated polyester A film was obtained. The thickness of the PET film in the obtained laminated polyester film was 100 탆. The resin layer X is a composition which contains an acrylic structure (A), a urethane structure (B) and a naphthalene structure (C) and does not contain a carbodiimide structure (D) from the composition of the coating composition.

Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. It has an excellent transparency due to low haze and is excellent in initial adhesion with a hard coat layer and adhesion to moisture and heat resistance and has a small reflectance change amount DELTA R before and after the self-extinguishing treatment test, Oligomer inhibition property and visibility were good.

(Examples 2 to 3)

A laminated polyester film was obtained in the same manner as in Example 1 except that the following melamine compound (e) was used and the weight ratio of solids in (e) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By containing the melamine compound as compared with Example 1, the reflectance change amount? R before and after the mercury treatment test was reduced, the mastic adhesion and the UV resistance were excellent, and the excellent transparency, the initial adhesion, Heat water transparency, oligomer inhibition, and visibility.

Water dispersion of melamine compound (e): "NIKARAK" (registered trademark) MW12LF (solid concentration: 71% by weight) manufactured by Sanwa Chemical Co.,

(Example 4)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of solids of the melamine compound (e) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. The increase in the content of the melamine compound (e) compared to Example 3 resulted in a slightly higher initial haze, a slightly increased reflectance change amount DELTA R and a dispersion index before and after the self-extinguishing test, and transparency, But showed good initial and equivalent initial adhesion, anti-wet heat adhesion, heat-resistant water resistance, oligomer suppression, and visibility.

(Example 5)

A laminated polyester film was obtained in the same manner as in Example 3 except that the polyester resin (b-2) was used as the polyester compound (b). Properties and other properties of the obtained laminated polyester film are shown in Table 2-1.

By using the polyester resin (b-2) having a small content of the aromatic dicarboxylic acid component containing the sulfonic acid metal base as compared with Example 3, the initial haze was slightly higher, and the reflectance change amount? R before and after the self- The index slightly increased, and transparency, mabi adhesion, UV resistance, and heat resistance water transparency were slightly decreased, but good initial adhesive property, anti-wet heat adhesion, oligomer suppression property, and visibility were exhibited.

(Examples 6 to 7)

(Example 6) and the polyester resin (b-4) (Example 7) were used as the polyester compound (b) ≪ / RTI > Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By using a polyester resin containing a large amount of an aromatic dicarboxylic acid component containing a sulfonic acid metal base as compared with Example 3, the initial haze was slightly lower and the reflectance change amount? R before and after the blackening treatment test was equal, And exhibited excellent initial adhesion, anti-wet heat adhesion, anti-magnetic adhesion, anti-UV adhesion, heat-resistant water resistance, oligomer suppression, and visibility, which were equivalent.

(Example 8)

A laminated polyester film was obtained in the same manner as in Example 3 except that the polyester resin (b-5) was used as the polyester compound (b). Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By using a polyester resin containing a large amount of an aromatic dicarboxylic acid component containing a sulfonic acid metal base as compared with Example 3, the initial haze was slightly higher, the reflectance change amount? R and dispersion index before and after the blackening treatment test became larger, Transparency, visibility, initial adhesion, mabi adhesion, UV resistance, heat-resistant water transparency, and oligomer inhibition were slightly lower but good.

(Example 9)

A laminated polyester film was obtained in the same manner as in Example 3 except that the polyester resin (b-6) was used as the polyester compound (b). Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By using a polyester resin containing no aromatic dicarboxylic acid component containing a sulfonic acid metal base as compared with Example 3, the initial haze was slightly higher, the reflectance change amount? R and dispersion index before and after the blackening treatment test became larger, Transparency, visibility, initial adhesion, mabi adhesion, UV resistance, heat resistance water transparency, and oligomericity were all slightly better.

(Examples 10 to 11)

(B-7) (Example 10) and polyester resin (b-8) (Example 11) were used as the polyester compound (b) ≪ / RTI >

Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By using a polyester resin having a different bisphenol S skeleton as compared with Example 3, the oligomer inhibition property was slightly lowered, but the reflectance change amount DELTA R before and after the self-pretreatment test was small, and the excellent initial adhesion property, Adhesion resistance, mabi adhesion, UV resistance, heat resistance water transparency, and visibility.

(Example 12)

A laminated polyester film was obtained in the same manner as in Example 3, except that the solid content ratio of the isocyanate compound (c) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By reducing the content of the isocyanate compound (c) as compared with Example 3, the reflectance change amount? R before and after the self-abrasion treatment test was slightly increased, and the initial adhesion, anti-wet heat adhesion, The transparency was slightly lowered, but exhibited equivalent transparency, oligomer suppressing property, and visibility.

(Examples 13 to 14)

A laminated polyester film was obtained in the same manner as in Example 3, except that the solid content ratio of the isocyanate compound (c) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By increasing the content of the isocyanate compound (c) in comparison with Example 3, it is possible to increase the content of the isocyanate compound (c) .

(Example 15)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of solids of the oxazoline compound (d) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. By reducing the content of the oxazoline compound (d) as compared with Example 3, the reflectance change amount? R before and after the mercury treatment test was slightly increased, and the initial adhesion, anti-wet heat adhesion, The oligomer inhibition property was slightly decreased, but good, equivalent transparency, visibility, and heat resistance water transparency were exhibited.

(Example 16)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of solids of the oxazoline compound (d) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. It is possible to increase the content of the oxazoline compound (d) in comparison with that of Example 3, and to provide the same excellent transparency, initial adhesive property, anti-wet heat bonding property, Respectively.

(Example 17)

A laminated polyester film was obtained in the same manner as in Example 3 except that the following oxazoline compound (d-2) was used as the oxazoline compound (d). Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. Even when the oxazoline compound (d-2) having a terminal structure and a different degree of polymerization were used as compared with Example 3, the same transparency, initial adhesion, anti-wet heat adhesion, Transparency, and oligomer inhibition.

Water dispersion of oxazoline compound (d-2): "Epochros" WS-700 (solid content concentration: 40% by weight) manufactured by Nippon Shokubai Co.,

(Examples 18 to 19)

A laminated polyester film was obtained in the same manner as in Example 3 except that the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. (A) / polyester resin (b) = 30/70 (Example 18), acrylic urethane copolymer resin (a) / polyester resin (b) (Example 19), the reflectance change amount? R and dispersion index before and after the mercury treatment test slightly increased, the reflectance slightly decreased, and the haze slightly increased. In addition, it showed good initial adhesive property, anti-wet heat bonding property, and heat-resistant water-resistance transparency although the resistance to mabi adhesion, resistance to UV, oligomeric property and visibility were slightly decreased.

(Example 20)

A laminated polyester film was obtained in the same manner as in Example 3 except that the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) was changed to the values shown in Table 1-1. Properties and other properties of the obtained laminated polyester film are shown in Table 2-1. Even when the acrylic urethane copolymer resin (a) / polyester resin (b) = 20/80 was used as compared with Example 3, the reflectance change amount? R before and after the mercury treatment test slightly increased the oligomer inhibition property. Initial adhesive property, anti-wet heat adhesion, anti-self-adhesive property, anti-UV adhesive property, heat-resistant water transparency, and visibility.

(Example 21)

A laminated polyester film was obtained in the same manner as in Example 3, except that the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) was changed to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. (A) / polyester resin (b) = 5/95 as compared with Example 3, the dispersion index was slightly reduced, the haze was slightly decreased, the reflectance was slightly increased, and the transparency, oligomer suppression Sex was good. Also, since the reflectance change amount? R slightly increased before and after the self-abrasion treatment test, the initial adhesion, anti-wet heat adhesion, anti-magnetic adhesion, UV resistance, heat resistance water transparency and visibility were slightly lowered.

(Example 22)

A laminated polyester film was obtained in the same manner as in Example 3, except that the solid content ratio of the isocyanate compound (c) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. Since the content of the isocyanate compound (c) was decreased as compared with Example 3, the transparency, visibility and oligomer suppressing properties were excellent, and the reflectance change amount? R slightly increased before and after the self- , The resistance to abrasion resistance, the resistance to UV in the inside, and the transparency to water resistance were slightly lowered, but good.

(Example 23)

A laminated polyester film was obtained in the same manner as in Example 3 except that the solid content ratio of the isocyanate compound (c) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. As the content of the isocyanate compound (c) was increased as compared with Example 3, the haze was slightly increased, and the transparency and the oligomer inhibiting property were slightly lowered. In addition, since the reflectance change amounts DELTA R before and after the self-abrasion treatment test were the same, they exhibited equivalent initial adhesion, anti-wet heat adhesion, anti-magnetic adhesion, UV resistance and water resistance.

(Example 24)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of solids of the oxazoline compound (d) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. The content of the oxazoline compound (d) was decreased as compared with Example 3, and the oligomer suppressing property was slightly lowered. However, since the reflectance change amount? R slightly increased before and after the resistivity test, Resistance to moisture resistance, resistance to moisture resistance, water resistance to water resistance, and water resistance.

(Example 25)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of solids of the oxazoline compound (d) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. As the content of the oxazoline compound (d) was increased as compared with Example 3, the haze was slightly increased and the transparency was slightly decreased. Also, since the reflectance change amounts DELTA R before and after the self-extinguishing treatment test were equivalent, they exhibited equivalent initial adhesiveness, anti-wet heat adhesion, anti-magnetic adhesion, UV resistance, heat resistance water resistance and oligomer inhibition.

(Example 26)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of the solids of the melamine compound (e) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. The content of the melamine compound (e) was reduced as compared with Example 3, thereby showing the same excellent transparency, initial adhesion, anti-wet heat adhesion, and oligomer inhibition. In addition, since the reflectance change amount? R slightly increased before and after the self-abrasion treatment test, the self-adhesive property, the UV-adhesive property and the water-resistant water-resistance transparency were slightly lowered.

(Example 27)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratio of the solids of the melamine compound (e) was adjusted to the values shown in Table 1-2. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. As the content of the melamine compound (e) was increased as compared with Example 3, the dispersion index slightly increased and the haze slightly increased, but it was good. Also, the reflectance change amount DELTA R before and after the self-extinguishing treatment test was slightly increased, and the self-adhesive property and UV-adhesive property were slightly lowered.

(Example 28)

A laminated polyester film was obtained in the same manner as in Example 3 except that the polyester resin (b-9) was used as the polyester compound (b). Properties and the like of the obtained laminated polyester film are shown in Table 2-2. By using a polyester resin having a skeleton of bisphenol A in comparison with Example 3, the initial haze was slightly higher, the reflectance change amount? R before and after the blackening treatment test, the dispersion index was slightly large, the reflectance was small, and transparency, visibility, Although the self-adhesive property, the UV-adhesive property and the oligomer-repellency property were slightly lowered, the same showed excellent initial adhesion and anti-wet heat adhesion.

(Example 29)

A laminated polyester film was obtained in the same manner as in Example 3 except that the polyester resin (b-10) was used as the polyester compound (b). Properties and the like of the obtained laminated polyester film are shown in Table 2-2. By using a polyester resin having a skeleton of bisphenol A in comparison with Example 3, the initial haze was slightly higher, the reflectance change amount? R before and after the blackening treatment test, the dispersion index, the oligomer suppressing property were slightly higher, , Visibility, mabi adhesion, and UV-curability were somewhat lowered, but exhibited equivalent initial adhesion and anti-wet heat adhesion.

(Example 30)

A laminated polyester film was obtained in the same manner as in Example 1 except that the polyester resin (b-2) was used as the polyester compound (b). Properties and the like of the obtained laminated polyester film are shown in Table 2-2.

By using the polyester resin (b-2) having a small content of the aromatic dicarboxylic acid component containing the sulfonic acid metal base as compared with Example 1, the initial haze was slightly higher, the dispersion index slightly increased, and the transparency, Resistance to water resistance, transparency to water resistance, and oligomer suppression were slightly lowered. However, the reflectance change amount DELTA R before and after the self-abrasion treatment test was excellent, and the same initial adhesion, anti-wet heat adhesion and visibility were exhibited.

(Examples 31 to 33)

Except that the polyester resin (b-2) was used as the polyester compound (b) and the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) was changed to the values shown in Table 1-2 A laminated polyester film was obtained in the same manner as in Example 3. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. (A) / polyester resin (b) = (b-2) was obtained by using a polyester resin (b-2) having a small content of aromatic dicarboxylic acid component containing a sulfonic acid metal base, (A) / polyester resin (b) = 40/60 (Example 31), acrylic urethane copolymer resin (a) / polyester resin (b) = 30/70 20/80 (Example 33), the dispersion index was slightly increased, the reflectance was slightly decreased, the haze was slightly increased, and the oligomer controllability was slightly lowered. Further, the reflectance change amount DELTA R before and after the self-extinguishing treatment test slightly increased, and showed excellent initial adhesion, anti-wet heat adhesion, and heat resistance water transparency although the resistance to mabi adhesion, UV resistance and visibility decreased slightly.

(Example 34)

A laminated polyester film was obtained in the same manner as in Example 3 except that the film thickness of the resin layer (X) was changed. Properties and the like of the obtained laminated polyester film are shown in Table 2-2. By decreasing the film thickness of the resin layer (X) as compared with Example 3, the reflectance was lowered, the visibility was slightly lowered, and the oligomer suppressing property was slightly lowered, but the initial adhesive property, Self-adhesive property, UV-adhesive property and heat-resistant water-transparency.

(Comparative Example 1)

A laminated polyester film was obtained in the same manner as in Example 1, except that the weight ratios of the solid components (a) to (e) were adjusted to the values shown in Table 1-3. Properties and the like of the obtained laminated polyester film are shown in Table 2-3. The laminated polyester film of Comparative Example 1 did not contain an acryl-urethane copolymer resin, so that it exhibited excellent transparency and oligomer-suppressing property equivalent to those of Example 1, but the reflectance change amount? R before and after the self- And exhibited poor performance in terms of anti-wet heat resistance, mastic adhesion, UV-visibility, and visibility.

(Comparative Examples 2 to 3)

A laminated polyester film was obtained in the same manner as in Example 3 except that the weight ratios of the solid components in (a) to (e) were adjusted to the values shown in Table 1-3. Properties and the like of the obtained laminated polyester film are shown in Table 2-3. The laminated polyester films of Comparative Examples 2 and 3 did not contain the polyester resin (b) having a naphthalene skeleton, and thus the reflectance change amount? R before and after the excellent masticatory treatment test as compared with Example 3, transparency, Heat resistance, anti-wet heat resistance, anti-magnetic adhesion, UV resistance, and oligomer suppression, but the performance was poor in visibility.

(Comparative Examples 4 to 5)

A laminated polyester film was obtained in the same manner as in Example 3, except that the weight ratios of the solid components (a) to (e) were adjusted to the values shown in the table. Properties and the like of the obtained laminated polyester film are shown in Table 2-3.

Since the laminated polyester film of Comparative Example 4 does not contain the isocyanate compound (c), it shows comparable transparency, good visibility and oligomer suppression property as compared with Example 3, but the reflectance change amount? R before and after the self- And the performance was poor in terms of wet heat adhesion, mastic adhesion, and UV resistance.

Further, since the laminated polyester film of Comparative Example 5 does not contain the oxazoline compound (d), it exhibits the same excellent transparency and good visibility as in Example 3, but the reflectance change amount? R before and after the self- Resistance to weathering resistance, resistance to moisture and heat, resistance to intumescent adhesion, resistance to UV, resistance to water resistance, and oligomer suppression.

(Comparative Examples 6 to 9)

A laminated polyester film was obtained in the same manner as in Example 3, except that the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) was changed to the values shown in Table 1-3. Properties and the like of the obtained laminated polyester film are shown in Table 2-3.

The laminated polyester film of Comparative Example 6 had a dispersion index of 7 and a slight increase in haze, as compared with Example 3, by setting the acrylic urethane copolymer resin (a) / polyester resin (b) = 50/50, The reflectance was reduced. In addition, although it exhibits excellent initial adhesion and anti-wet heat adhesion properties equivalent to each other, the reflectance change amount? R before and after the self-abrasion treatment test was poor in terms of the adhesion to the interior, the UV resistance to heat, the transparency to water resistance, and the visibility to oligomers.

The laminated polyester film of Comparative Example 7 had a dispersion index of 10 and a lower reflectance when the acrylic urethane copolymer resin (a) / the polyester resin (b) = 60/40 as compared with Example 3, And the transparency was deteriorated. In addition, although the same initial adhesive property and anti-wet heat adhesion property were exhibited, the reflectance change amount? R before and after the self-abrasion treatment test was inferior in the adhesion to the inner barrier, the adhesion to the inner wall, the transparency to the hot water, and the visibility to the oligomer.

The laminated polyester film of Comparative Example 8 had a dispersion index of 15 and a lower reflectance when the acrylic urethane copolymer resin (a) / polyester resin (b) = 80/20 as compared with Example 3, And the transparency was deteriorated. In addition, although the same initial adhesive property and anti-wet heat adhesion property were exhibited, the reflectance change amount? R before and after the self-abrasion treatment test was inferior in the adhesion to the inner barrier, the adhesion to the inner wall, the transparency to the hot water, and the visibility to the oligomer.

The laminated polyester film of Comparative Example 9 had a dispersion index increased to 20, a reflectance decreased, haze increased, and transparency was improved by setting the acrylic urethane copolymer resin (a) / polyester resin (b) = 90/10 It was falling. In addition, although the same initial adhesive property and anti-wet heat adhesion property were exhibited, the reflectance change amount? R before and after the self-abrasion treatment test was inferior in the adhesion to the inner barrier, the adhesion to the inner wall, the transparency to the hot water, and the visibility to the oligomer.

(Comparative Examples 10 to 11)

A laminated polyester film was obtained in the same manner as in Example 3 except that the following carbodiimide compound (g) was used and the weight ratio of solids in (g) was changed to the values shown in Table 1-3. Properties and the like of the obtained laminated polyester film are shown in Table 2-3. Compared with Example 3, the content of the carbodiimide compound was comparable to that of Example 3, but the transparency, initial adhesion, anti-wet heat adhesion, heat-resistant water transparency and visibility were the same as in Example 3, (c), the oxazoline compound (d), and the melamine compound (e) is inhibited, the resin layer having a high degree of crosslinking can not be formed and the oligomer inhibition property is poor.

Water dispersion of carbodiimide compound (g): "Carbodilite" V-04 (solid content concentration: 40% by weight) manufactured by Nisshinbo Chemical Co.,

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Table 2-1]

[Table 2-2]

[Table 2-3]

The present invention relates to a laminated polyester film having a resin layer excellent in not only initial adhesion but also excellent anti-wet heat bonding property, anti-magnetic adhesion property and heat resistance water transparency and excellent suppression of interference fringes when laminated with a hard coating layer And is excellent in adhesiveness to various kinds of laminated articles such as an easy-to-use optical film for various display applications, an easy-to-adhere film for hard coating films for industrial use such as window glass for automobiles and buildings, It is usable for easy-to-adhere film.

1: Resin layer (X)
2: polyester film
3: X direction
4: Y direction
5: Z direction

Claims (10)

On at least one side of the polyester film
As a laminated polyester film having a resin layer (X)
When the resin layer (X)
(A), a urethane structure (B), and a naphthalene structure (C)
It does not include the carbodiimide structure (G)
Wherein a change amount? R of the spectral reflectance before and after the resistivity treatment on the side of the resin layer (X) is 0% or more and 2% or less. The laminated polyester film according to claim 1, wherein the surface zeta potential of the resin layer (X) is -20 mV or more. The laminated polyester film according to any one of claims 1 to 4, wherein the minimum value of the spectral reflectance on the side of the resin layer (X) in the wavelength range of 450 nm to 650 nm is 4.5% or more and 6.0% or less. 4. The resin composition according to any one of claims 1 to 3, wherein the resin layer (X)
The acrylic urethane copolymer resins (a) and
The polyester resin (b) having a naphthalene skeleton and
The isocyanate compounds (c) and
Is a layer formed by using a coating composition comprising an oxazoline compound (d). The method according to claim 4, wherein the aggregate containing the acrylic-urethane copolymer resin (a) of the resin layer (X) has a dispersion index of 5 or less,
Wherein the ratio of the acrylic urethane copolymer resin (a) in the coating composition is 3% by weight or more. The polyester resin composition according to claim 4 or 5, wherein the polyester resin (b) contains an aromatic dicarboxylic acid component containing a sulfonic acid metal base in an amount of 1 to 30 mol% based on the total dicarboxylic acid component of the polyester A laminated polyester film characterized by being a polyester resin. The laminated polyester film according to any one of claims 4 to 6, wherein the polyester resin (b) comprises a diol component represented by the following formula (1).

(- represents a _{(C n H 2n O) m} -H (n = 2 or more than 4, m = 1 or more integer of 15) wherein, X ^1, X ²⁾ The coating composition according to any one of claims 4 to 7, wherein the solid content ratio of the acrylic urethane copolymer resin (a) and the polyester resin (b) in the coating composition is 40/60 to 5/95 Polyester film. 9. The coating composition according to claim 8, wherein when the sum of the solid content weight of the acrylic urethane copolymer resin (a) and the polyester resin (b) is 100 parts by weight,
Isocyanate compound (c) in an amount of 3 to 20 parts by weight,
And the oxazoline compound (d) is contained in an amount of 20 to 50 parts by weight as solids. The coating composition according to claim 9, wherein the coating composition further comprises 5 to 30 parts by weight of the melamine compound (e) when the total weight of the solid content of the acrylic urethane copolymer resin (a) and the polyester resin (b) By weight based on the total weight of the polyester film.

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