WO2016035850A1

WO2016035850A1 - Layered film

Info

Publication number: WO2016035850A1
Application number: PCT/JP2015/075061
Authority: WO
Inventors: 麻莉鎌田; 昌文二科; 崇嗣杉原; 佑樹永島
Original assignee: ユニチカ株式会社
Priority date: 2014-09-05
Filing date: 2015-09-03
Publication date: 2016-03-10
Also published as: TW201623009A; KR20170052580A; JP6063612B2; CN106660351A; JPWO2016035850A1

Abstract

　The present invention provides a layered film that adheres sufficiently well to a coating layer such as a hard coating layer, and oligomer separation from the coating layer is suppressed during heat treatment. The present invention pertains to a layered film having a polyester resin layer on at least one surface of a polyester film substrate, wherein 5 to 70% (molar) of a diol component of the polyester resin constituting the polyester resin layer is a diol component having a tricyclodecane structure, and the degree of change in haze when the film is heat treated for one hour at 150°C is 1.0% or less.

Description

Laminated film

The present invention relates to a laminated film suitable for electronic materials.

The biaxially oriented polyester film is used as a substrate in various fields such as optical applications because of its excellent stability and mechanical and electrical properties.

Since polyester film generally has low adhesion to various coating layers, an adhesive modification layer (also known as an easy-adhesion layer) composed of various polymers, crosslinking agents, coupling agents, etc. is provided between the polyester film substrate and the coating layer. Providing).

For example, Patent Document 1 discloses a polyester film provided with an easy adhesion layer containing an acrylic resin or a polyester resin.

In recent years, due to the diversification of uses of polyester films, the processing conditions and the use environment have been raised to high temperatures, and accordingly, oligomers contained in the polyester film of the substrate may be precipitated. In this case, problems such as a decrease in transparency of the film due to the precipitated oligomer, contamination of the line, and a decrease in adhesiveness occur.

In order to solve the above problems, studies have been made to sequentially laminate an oligomer prevention layer and an adhesive layer on a polyester film (Patent Document 2).

Also, a laminated polyester film having three or more layers in which the amount of oligomer in the film substrate is reduced by forming a film using a polyester resin subjected to solid phase polymerization treatment has been conventionally known (Patent Document 3).

On the other hand, using an aqueous polyester resin dispersion containing specific amounts of aromatic dicarboxylic acid and tricyclodecane dimethanol as the acid component and alcohol component constituting the polyester resin, adhesion, transparency, water resistance, A technique for forming a resin film excellent in performance such as solvent resistance and heat resistance is disclosed (Patent Document 4). Also, a copolyester resin comprising a dicarboxylic acid component containing a specific amount of aromatic dicarboxylic acid and a glycol component containing a specific amount of tricyclodecane dimethanol, having a glass transition temperature of more than 30 ° C. and 70 ° C. or less. A technique for improving the hot adhesiveness and wet heat durability by using is disclosed (Patent Document 5).

JP 2010-76439 A JP2012-92314A JP 2000-141570 A JP 2011-137086 A Japanese Patent No. 5466095

However, in the method of sequentially laminating an oligomer prevention layer and an adhesive layer on a polyester film as in Patent Document 2, the effect of suppressing oligomer precipitation was not sufficient. Moreover, since two layers are sequentially laminated on the polyester film, a plurality of manufacturing steps are required, the yield of the product is reduced, and the manufacturing cost is increased.

Also, as disclosed in Patent Document 3, a method using a polyester resin obtained by subjecting a polyester film to solid phase polymerization treatment is difficult to adopt because of its high cost.

Furthermore, when a resin film was formed between the polyester film and a coat layer such as a hard coat layer using the polyester resin aqueous dispersion described in Patent Document 4, the adhesion of the coat layer was not sufficient. When the polyester resin described in Patent Document 5 is applied to a film as an adhesive and laminated, the blocking resistance is not sufficient, and it may not be formed into a roll.

The present invention is intended to solve the above problem, and is a polyester-based laminated film that is sufficiently excellent in adhesiveness with a coat layer such as a hard coat layer and that suppresses oligomer precipitation from the coat layer during heat treatment. Is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by providing a polyester resin layer having a specific monomer structure on a polyester film substrate. Reached.

That is, the gist of the present invention is as follows.
(1) A laminated film having a polyester resin layer on at least one surface of a polyester film substrate, wherein 5 to 70 mol% of a diol component of the polyester resin constituting the polyester resin layer has a tricyclodecane structure The laminated film has a haze change amount of 1.0% or less when heat-treated at 150 ° C. for 1 hour.
(2) The laminated film according to (1), wherein 0.1 to 15 mol% of the dicarboxylic acid component of the polyester resin constituting the polyester resin layer is a dicarboxylic acid component having a sulfonate group.
(3) The laminated film according to (2), wherein 3 to 8 mol% of the dicarboxylic acid component of the polyester resin constituting the polyester resin layer is a dicarboxylic acid component having a sulfonate group.
(4) The polyester resin layer further contains a curing agent, and the content of the curing agent is 1 to 10 parts by mass with respect to 100 parts by mass of the polyester resin. The laminated film as described.
(5) The coating liquid containing the polyester resin is applied to a polyester film substrate, and then subjected to a heat drying treatment at a temperature of 180 ° C. or higher, (1) to (4), A method for producing a laminated film.
(6) The method for producing a polyester-based laminated film according to (5), wherein the polyester film substrate coated with the coating solution is stretched in at least one direction.

According to the present invention, it is possible to provide a polyester-based laminated film that is sufficiently excellent in adhesiveness with various coat layers and in which oligomer precipitation from the base polyester film is reduced. Since the polyester-based laminated film of the present invention can suppress oligomer precipitation from the surface of the coating layer during heat treatment, line contamination and film transparency reduction are suppressed. Therefore, even if it is incorporated as a member in a touch panel or a smartphone, the resolution of the optical element is not impaired.

The polyester-based laminated film of the present invention has a polyester resin layer containing a polyester resin containing a diol component having a tricyclodecane structure on the surface of the polyester film substrate.

The polyester resin used for the polyester film substrate is not particularly limited, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate. You may copolymerize another component with a polyester resin as needed.

Other components include carboxylic acid components, hydroxycarboxylic acid components, and alcohol components. Examples of the carboxylic acid component include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid , Maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, cyclohexanedicarboxylic acid, trimellitic acid, trimesic acid, and pyromellitic acid. Examples of the hydroxycarboxylic acid component include 4-hydroxybenzoic acid, ε-caprolactone, and lactic acid. Examples of the alcohol component include ethylene glycol, diethylene glycol, 1,3-propanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and bisphenol. Examples include ethylene oxide adducts of A and bisphenol S, trimethylolpropane, glycerin, and pentaerythritol. Two or more of these copolymer components may be used in combination.

The melting point of the polyester resin for the substrate is preferably 230 ° C. or higher from the viewpoint of imparting heat resistance.

Examples of the method for polymerizing the polyester resin for the substrate include known production methods such as a direct esterification method and a transesterification method. Examples of the direct esterification method include a method in which a necessary monomer raw material is injected into a reaction vessel, an esterification reaction is performed, and then a polycondensation reaction is performed. In the esterification reaction, the reaction is performed by heating and melting at a temperature of 160 ° C. or higher for 4 hours or longer in a nitrogen atmosphere. At that time, oxides such as magnesium, manganese, zinc, calcium, lithium, titanium, and acetate may be used as the catalyst. In the polycondensation reaction, the polycondensation reaction proceeds under a reduced pressure of 130 Pa or less until a desired molecular weight is reached at a temperature of 220 to 280 ° C. At that time, an oxide such as antimony, titanium, germanium, or acetate may be used as a catalyst.

Since the polyester resin for the base material after polymerization contains monomers, oligomers, and by-products such as acetaldehyde and tetrahydrofuran, it was obtained by performing solid-state polymerization at a temperature of 200 ° C. or higher under reduced pressure or under an inert gas flow. A polymer having a higher degree of polymerization may be used for the polyester film substrate.

When polymerizing the polyester resin for the substrate, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antistatic agent, a slip agent, an antiblocking agent, etc. may be added as necessary. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of the heat stabilizer include phosphorus compounds. Examples of the ultraviolet absorber include benzophenone compounds and benzotriazole compounds. Examples of the antistatic material include antimony-doped tin oxide. Examples of the slip agent include surfactants. Examples of the antiblocking agent include silicon oxide.

The base material polyester film used in the present invention may be an unstretched film or a stretched film. The unstretched film is supplied with a sufficiently dried polyester resin raw material to the extruder, melted at a temperature higher than the fluidity, and passed through a filter as necessary. It can be obtained by extruding onto a cooling drum whose temperature is adjusted below the point (Tg).

In the uniaxial stretching method, an unstretched film is stretched in a temperature range of Tg to (Tg + 50 ° C.) of the polyester resin so as to have a stretching ratio of about 2 to 6 times in the horizontal direction or the vertical direction. In the simultaneous biaxial stretching method, the unstretched film is biaxially stretched in the temperature range of Tg to (Tg + 50 ° C.) of the polyester resin so that the stretching ratio is about 2 to 4 times in the transverse direction and the longitudinal direction. In this case, pre-longitudinal stretching of about 1 to 1.2 times may be performed before guiding to the simultaneous biaxial stretching machine. In the sequential biaxial stretching method, the unstretched film is heated with a roll, infrared rays, or the like, and stretched in the longitudinal direction to obtain a longitudinally stretched film. Stretching preferably uses a difference in peripheral speed of two or more rolls and is 2.5 to 4.0 times in the temperature range of Tg to (Tg + 40 ° C.) of the polyester resin. Subsequently, the longitudinally stretched film is continuously subjected to transverse stretching, heat setting, and thermal relaxation to form a biaxially stretched film. The transverse stretching starts in the temperature range of Tg to (Tg + 40 ° C.) of the polyester resin, and the maximum temperature is preferably in the temperature range of (Tm-100 ° C.) to (Tm-40 ° C.) of the polyester resin (Tm Is the melting point of the polyester resin). The transverse stretching ratio is adjusted depending on the required physical properties of the final film, but is preferably 3.5 times or more, more preferably 3.8 times or more, and 4.0 times or more. Is more preferable. The film can be stretched in the machine direction and the transverse direction, and further stretched in the machine direction and / or the transverse direction to increase the elastic modulus and dimensional stability of the film. Following stretching, heat fixing treatment for several seconds in the temperature range (Tm-50 ° C.) to (Tm-10 ° C.) of the polyester resin, and relaxation of 1-10% in the transverse direction of the film simultaneously with the heat fixing treatment preferable.

In order to improve the winding property of the film, particles may be added to the polyester film used for the substrate.

The type of particles to be blended in the substrate is not particularly limited, and specific examples include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, Inorganic particles such as titanium oxide can be used. Moreover, you may use heat-resistant organic particles, such as a thermosetting urea resin, a thermosetting phenol resin, a thermosetting epoxy resin, and a benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used. The shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular about the hardness, specific gravity, a color, etc. Two or more kinds of these particles may be used in combination as required.

The average particle size of the particles used is usually in the range of 0.01 to 3 μm, preferably 0.01 to 1 μm. When the average particle diameter is less than 0.01 μm, the particles are likely to aggregate and dispersibility may be insufficient. On the other hand, when the average particle diameter exceeds 3 μm, the surface roughness of the film becomes too rough and There may be a problem when a release layer is applied in the process.

The particle content in the polyester film substrate is usually 5% by mass or less, preferably in the range of 0.005 to 3% by mass. If the particles are added in excess of 5% by mass, the transparency of the film may be insufficient.

The method for adding particles to the polyester film substrate is not particularly limited, and can be added at any stage of producing the polyester. For example, it is an esterification stage or a transesterification completion stage.

The substrate polyester film used in the present invention may have a single layer or multiple layers (for example, two types, two types, two types, three layers, three types, three layers). From the viewpoint of controlling the degree and improving handling properties such as winding property, a multilayer structure is preferable. Two types, two layers, and two types and three layers are particularly preferable. The two-layer / two-layer structure is a two-layer structure manufactured using two kinds of layer forming materials, and these two layers have different compositions (for example, particle content). The two-layer / three-layer configuration is a three-layer configuration manufactured using two types of layer-forming materials, and the two outermost layers and the intermediate layer have different compositions (for example, particle content). Yes. The three-layer / three-layer structure is a three-layer structure manufactured using three kinds of layer forming materials, and these three layers have different compositions (for example, particle content).

The polyester film base material preferably has a multilayer structure having a layer containing particles in at least one outermost layer.

When the polyester film substrate has a multilayer structure, the thickness ratio in each layer of the multilayer is preferably the following ratio from the viewpoint of stability during production and transparency. For example, in the case of two types and two layers, the thickness ratio of each layer is preferably 99: 1 to 1:99, more preferably 96: 4 to 4:96, and still more preferably 90:10 to 10:90. Further, for example, in the case of two types and three layers, when the total thickness of each layer is 100%, the thickness of the intermediate layer is preferably 98 to 1%, more preferably 92 to 4%, and further preferably 80 to 10%. . At this time, the thicknesses of the outermost layer on one side and the other adjacent to the intermediate layer are each independently preferably 1 to 49.5%, more preferably 4 to 48%, and further preferably 10 to 45%.

A polyester film substrate having a multilayer structure can be produced, for example, by the following method;
(1) A method in which two or more kinds of polyester resin compositions (layer forming materials) are separately melted, merged and laminated in layers, extruded from a multilayer die, laminated and fused before solidification, and then solidified;
(2) A method of stretching and heat setting after the method of (1) above;
(3) A method in which two or more kinds of polyester resin compositions (layer forming materials) are separately melted, extruded without being joined together to form a film, and then two or more kinds of films are laminated and fused; and ( 4) A method of laminating and fusing two or more kinds of stretched films after forming into a film and stretching in the method of (3) above.

For the polyester film substrate, the above-described methods (1) and (2) are preferably used in which a multi-layer die is used and laminated and fused before solidification, because of the simplicity of the process.

Examples of the method for forming the polyester resin layer on the polyester film substrate as described above include a method in which a coating liquid containing a polyester resin is applied on the substrate and then dried.

The application method of the coating liquid is not particularly limited, and examples thereof include a gravure roll method, a reverse roll method, an air knife method, a reverse gravure method, a Mayer bar method, an inverse roll method, or various coating methods based on a combination thereof. It is done. Various spraying methods can also be employed. The coating thickness is such that the thickness after drying (especially the thickness after heat drying) falls within the following range from the viewpoints of further reduction of the precipitated oligomer, improvement of blocking resistance, prevention of coating defects and improvement of productivity. It is preferable to make it a small value. The thickness after drying (particularly the thickness after heat drying) is preferably 0.01 to 2 μm, more preferably 0.03 to 1 μm, and further preferably 0.04 to 0.5 μm. 0.2 to 0.5 μm is most preferable.

Although it does not specifically limit as a drying method, From a viewpoint of the further improvement of the adhesiveness of a polyester resin layer and a coating layer (for example, acrylic coating film), it is preferable to employ | adopt the heat drying process method which heats and dries. Although the reason is not clear, the adhesiveness is remarkably increased when the heat drying temperature of the polyester resin layer is 140 ° C. or higher, particularly 180 ° C. or higher. The heat drying treatment temperature is preferably 140 to 250 ° C., preferably 160 to 230 ° C., particularly 180 to 230 ° C., from the viewpoint of further improving the adhesiveness and preventing thermal wrinkling and deformation of the polyester film substrate. Is more preferable. The heat drying treatment time is preferably 5 to 60 seconds, more preferably 20 to 60 seconds.

The polyester resin layer can be formed by an inline coating method or a post coating method. The in-line coating method is a method in which a coating liquid is applied to an unstretched film or a uniaxially stretched film and then stretched in at least one direction. The stretching method may be determined according to the stretched state of the film before coating. For example, when the film before coating is an unstretched film, the stretching method after coating is a sequential biaxial stretching method or a simultaneous biaxial stretching method. For example, when the film before coating is a film that is uniaxially stretched in a predetermined direction (MD direction or TD direction), the stretching method after coating is uniaxially stretched in the unstretched direction (TD direction or MD direction). Stretching method. On the other hand, the post-coating method is a method in which an unstretched film is converted into a biaxially stretched film by a sequential biaxial stretching method or a simultaneous biaxial stretching method, and a coating solution is applied to the biaxially stretched film.

In general, the in-line coating method is more productive and economical than the post-coating method. Further, in the in-line coating method, since the coating liquid is applied to an unstretched film or a uniaxially stretched film, it can be heated at a high temperature. In the present invention, since the resin layer is preferably heat-dried at 140 to 250 ° C., an in-line coating method that can be heated at a high temperature is preferable. By employing the in-line coating method, it is possible to suppress thermal wrinkles that occur due to the shrinkage of the polyester film accompanying the heat drying treatment.

The polyester resin used in the polyester resin layer of the present invention (hereinafter referred to as polyester resin (A)) is mainly composed of a dicarboxylic acid component and a diol component. That the polyester resin (A) is mainly composed of a dicarboxylic acid component and a diol component is 35 to 50 mol%, preferably 45 to 50 mol%, more preferably among all monomer components constituting the polyester resin (A). Means that 48 to 50 mol% is the dicarboxylic acid component, and 35 to 50 mol%, preferably 45 to 50 mol%, more preferably 48 to 50% is the diol component. In the present specification, the content ratio of the monomer component of the polyester resin (A) is indicated by a value based on the amount of raw material used before polymerization.

It is necessary to contain 5 to 70 mol%, particularly 5 mol% or more and less than 70 mol% of a diol component having a tricyclodecane structure with respect to 100 mol% of the diol component constituting the polyester resin (A). From the viewpoint of further improving the adhesion between the resin layer and the coating layer (for example, acrylic coating film) and further reducing the amount of precipitated oligomer, it is preferably 10 to 60 mol%, more preferably 15 to 50 mol%. . When the content of the diol component having a tricyclodecane structure is less than 5 mol%, the effect of suppressing the precipitation of oligomers accompanying heat treatment is low. On the other hand, when it is 70 mol% or more, particularly when it exceeds 70 mol%, the adhesion between the formed polyester resin layer and the coating layer (for example, acrylic coating film) is poor.

Examples of the diol component having a tricyclodecane structure include a tricyclodecane compound represented by the following general formula (I).

In the general formula (I), X ₁ and X ₂ are groups having 1 to 4 carbon atoms and / or 1 to 4 moles of alkylene oxide added to the hydroxyalkylene group having 1 to 4 carbon atoms, They may be the same or different. The hydroxyalkylene group is a group in which one hydrogen atom of an alkyl group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms, is substituted with one hydroxyl group. The alkyl group may be linear or branched, and is preferably linear. The alkylene oxide is not particularly limited, but is preferably an alkylene oxide compound having 2 to 4 carbon atoms. Examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide. Addition of an alkylene oxide to a hydroxyalkylene group produces an ether bond based on the hydroxyl group of the hydroxyalkylene group and a hydroxyl group based on the epoxy group of the alkylene oxide. X ₁ and X ₂ usually only have to be bonded to different carbon atoms out of 10 carbon atoms constituting the three carbon 5-membered rings of the tricyclodecane structure, preferably different carbon 5-membered rings. It is bonded to the constituent carbon atoms, and more preferably X ₁ and X ₂ are bonded to the 6- and 2-positions of the tricyclodecane structure, respectively. A carbon atom constituting the tricyclodecane structure may be substituted with a monovalent substituent. The monovalent substituent is not particularly limited, and examples thereof include an alkyl group having 1 to 3 carbon atoms (specifically, a methyl group, an ethyl group, and a propyl group). Most preferred X ₁ and X ₂ are hydroxyalkylene groups having 1 to 4 carbon atoms, particularly 1 to 2 carbon atoms, which may be the same or different. The diol component having a tricyclodecane structure may be two or more compounds having different structures.

Examples of the compound represented by the general formula (I) include tricyclo [5.2.1.0 ^2,6 ] decandimethanol, 4,10-dimethyltricyclo [5.2.1.0 ^2,6 ]. Decandimethanol, 4,4,10,10-tetramethyltricyclo [5.2.1.0 ^2,6 ] decandimethanol, 1,2,3,4,5,6,7,8,9, An example is 10-decamethyltricyclo [5.2.1.0 ^2,6 ] decanedimethanol. Of these, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol is preferred because of its high versatility and high adhesion between the coating and the acrylic coating. In addition, you may use these in mixture of 2 or more types.

Examples of the diol component that can be used in combination with the compound represented by the general formula (I) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, and 2-methyl-1 , 3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropane Aliphatic glycols such as diols, 1,4-cyclohexanedimethanol, 1,3-cyclobutanedimethanol, dimethanol decalin, dimethanol bicyclooctane and other alicyclic glycols, diethylene glycol, triethylene glycol, dipropylene glycol, polytetra Methylene glycol, polyethylene glycol And ether bond-containing glycols such as polypropylene glycol, alkylene oxide adducts of 2,2-bis [4- (hydroxyethoxy) phenyl] propane, and alkylene oxide adducts of bis [4- (hydroxyethoxy) phenyl] sulfone. It is done. Among them, in terms of influence on versatility, polymerizability and resin properties, one or more diol components selected from the group consisting of aliphatic glycols, particularly ethylene glycol, neopentyl glycol, and 1,2-propanediol, It is preferably used together with a diol component having a tricyclodecane structure.

The content of the aliphatic glycol is usually 95 mol% or less, particularly 30 mol% or more and 95 mol% or less with respect to 100 mol% of the diol component constituting the polyester resin (A). From the viewpoint of further improving the adhesion with (for example, an acrylic coating film) and further reducing the amount of precipitated oligomers, it is preferably 31 to 85 mol%, more preferably 50 to 85 mol%. The content is preferably 51 to 85 mol% from the viewpoints of further improvement of adhesiveness, further reduction of precipitated oligomers and improvement of blocking resistance.

Since the polyester resin (A) has a dicarboxylic acid having a sulfonate group, it can be easily dispersed in water or a hydrophilic organic solvent. When the content of the dicarboxylic acid having a sulfonate group with respect to 100 mol% of the dicarboxylic acid component constituting the polyester resin (A) is 3 mol% or more, the stretchability of the polyester resin layer to the in-line coating is enhanced. On the other hand, the water resistance of the polyester resin layer is improved by setting it to 15 mol% or less, preferably 9 mol% or less, and particularly 8 mol% or less. Therefore, it is preferable from the viewpoint of water resistance to contain 0.1 to 15 mol% of dicarboxylic acid having a sulfonate group with respect to 100 mol% of the dicarboxylic acid component constituting the polyester resin (A). From the viewpoint of improving the stretch followability (during in-line coating), it is more preferably 3 to 9 mol%, particularly 3 to 8 mol%. The stretch following property is a property that even if the polyester resin layer is formed and then stretched, the polyester resin layer can be satisfactorily stretched following the polyester film substrate. The water resistance is a property that can prevent appearance changes such as whitening and swelling occurring in the polyester resin layer even when the laminated film of the present invention is immersed in water.

The dicarboxylic acid having a sulfonate group is preferably sodium sulfophthalate, for example, 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 5-potassium sulfoterephthalic acid, 5-lithium. Sulfoisophthalic acid, 5-lithium sulfoterephthalic acid, sodium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, sodium 2,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, 3,5 -Potassium di (carbo-β-hydroxyethoxy) benzenesulfonate, lithium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, dimethyl 5-sodium sulfoisophthalate, dimethyl 5-sodium sulfoterephthalate, 5 Potassium sulfoisophthalic acid dimethyl, include 5 lithium sulfoisophthalic acid dimethyl.

The dicarboxylic acid component other than the dicarboxylic acid having a sulfonate group is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, and 3-tert-butylisophthalic acid. , Aromatic dicarboxylic acids such as diphenic acid, oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, aicosane diacid, hydrogenated dimer acid, etc. Acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid, and other unsaturated aliphatic dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarbo Acid and its anhydrides, alicyclic dicarboxylic acids such as tetrahydrophthalic acid and its anhydride. Of these, aromatic dicarboxylic acids, particularly terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferred from the viewpoint of versatility, polymerizability, and resin properties.

The content of the aromatic dicarboxylic acid is usually 70 to 97 mol% with respect to 100 mol% of the dicarboxylic acid component constituting the polyester resin (A), and the polyester resin layer and the coating layer (for example, acrylic coating film) From the viewpoint of further improving the adhesiveness and further reducing the precipitated oligomer, it is preferably 80 to 95 mol%.

The polyester resin (A) may contain a hydroxycarboxylic acid component. Examples of the hydroxycarboxylic acid include 2-hydroxysebacic acid, 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, citric acid, isocitric acid, malic acid, 2-methyl-2-hydroxysuccinic acid, tartaric acid, tetrahydroxyadipine Examples thereof include alkylene oxide adducts of acid, ε-caprolactone, δ-valerolactone, γ-valerolactone, lactic acid, β-hydroxybutyric acid, p-hydroxybenzoic acid, and 4-hydroxyphenyl stearic acid. When using hydroxycarboxylic acid, the content is preferably 50 mol% or less, more preferably 40 mol% or less, out of a total of 100 mol% of all monomer components constituting the polyester resin (A). Preferably, it is more preferably 30 mol% or less.

The polyester resin (A) may contain a monocarboxylic acid component or a monoalcohol component. Examples of the monocarboxylic acid include benzoic acid, phenylacetic acid, lauric acid, palmitic acid, stearic acid, oleic acid and the like. Examples of the monoalcohol include cetyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, octyl alcohol, and stearyl alcohol.

The polyester resin (A) may contain a trifunctional or higher functional carboxylic acid or a trifunctional or higher functional alcohol. When the trifunctional or higher functional carboxylic acid or the trifunctional or higher functional alcohol is charged before the esterification reaction, the content may be 5 mol% or less with respect to 100 mol% of the dicarboxylic acid component or dialcohol component, respectively. Preferably, it is 4 mol% or less, more preferably 3 mol% or less.

Examples of the tri- or higher functional carboxylic acid include trimellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis (anhydrotrimethyl). And glycerol tris (anhydro trimellitate) and 1,2,3,4-butanetetracarboxylic acid. Examples of the trifunctional or higher functional alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

The glass transition temperature of the polyester resin (A) is not particularly limited, but from the viewpoint of improving blocking resistance and stretchability of the obtained polyester resin layer, it is 60 to 110 ° C., particularly more than 70 ° C. and 110 ° C. or less. It is preferable to be 80 to 110 ° C. from the viewpoint of further improving the blocking resistance. A glass transition temperature becomes so high that there are many diol components which have a tricyclodecane structure among the diol components which comprise a polyester resin (A). In diol components other than the diol component having a tricyclodecane structure, the glass transition temperature increases as the amount of the above-described aliphatic glycol component increases. The blocking resistance is a property that even if the laminated films of the present invention are stacked and stored at a high temperature, adhesion (blocking) does not occur between the films, and even if they occur, they can be easily peeled off.

Next, a method for producing the polyester resin (A) will be described.

The polyester resin (A) can be produced by a known method by combining the above monomers. For example, all the monomer components and / or low polymers thereof are reacted in an inert atmosphere to carry out an esterification reaction, followed by polycondensation reaction in the presence of a polycondensation catalyst under reduced pressure until the desired molecular weight is reached. A method of proceeding and a method of performing a depolymerization reaction by adding a tri- or higher functional carboxylic acid under an inert atmosphere after carrying out the method.

In the esterification reaction, the reaction temperature is preferably 180 to 260 ° C., the reaction time is preferably 2.5 to 10 hours, and more preferably 4 to 6 hours.

In the polycondensation reaction, the reaction temperature is preferably 220 to 280 ° C. The degree of vacuum is preferably 130 Pa or less. If the degree of vacuum is low, the polycondensation time may be long. It is preferable to gradually reduce the pressure over 60 to 180 minutes until it reaches 130 Pa or less from atmospheric pressure.

The polycondensation catalyst is not particularly limited, and examples thereof include known compounds such as zinc acetate, antimony trioxide, tetra-n-butyl titanate, and n-butylhydroxyoxotin. The amount of the catalyst used is preferably 0.1 to 20 × 10 ⁻⁴ mol per 1 mol of the dicarboxylic acid component.

In the depolymerization, the reaction temperature is preferably 160 to 280 ° C., and the reaction time is preferably 0.5 to 5 hours.

Next, in the present invention, a coating liquid (hereinafter referred to as a polyester resin coating liquid) used for forming a polyester resin layer will be described.

Examples of the polyester resin coating liquid include an organic solution in which the polyester resin (A) is dissolved in an organic solvent, and a dispersion liquid in which the polyester resin (A) is dispersed in an organic solvent and / or water. These polyester resin coating liquids can form a polyester resin composition layer by coating on a substrate and drying.

The polyester resin coating solution of the present invention preferably contains no emulsifier. The emulsifier referred to in the present invention includes a surfactant, a compound having a protective colloid action, a modified wax, an acid-modified product having a high acid value, a water-soluble polymer and the like. Such an emulsifier may be contained in an amount less than 0.1 parts by mass with respect to 100 parts by mass of the polyester resin (A) component as long as the effects of the present invention are not impaired. When 0.1 mass part or more of an emulsifier is contained, it exists in the tendency for the water resistance of a film to fall.

Examples of a method for producing a polyester resin coating liquid as an aqueous dispersion include a self-emulsification method. The self-emulsification method is a method for preparing a polyester resin aqueous dispersion containing an organic solvent by charging the polyester resin (A), water, and an organic solvent all at once and heating the system while stirring. If necessary, a basic compound may be added.

Examples of the organic solvent include ketones such as acetone (boiling point: 56.2 ° C.), methyl ethyl ketone (boiling point: 79.6 ° C.), methyl isobutyl ketone (boiling point: 117 ° C.), and cyclohexanone (boiling point: 156 ° C.). Organic solvents; aromatic hydrocarbon organic solvents such as toluene (boiling point: 111 ° C.), xylene (boiling point: 140 ° C.); ethylene glycol monoethyl ether (boiling point: 136 ° C.), tetrahydrofuran (boiling point: 66.0 ° C.) Ether-based organic solvents such as 1,4-dioxane (boiling point: 101 ° C.); halogen-containing organic solvents; alcohols such as n-propanol (boiling point: 97.2 ° C.) and isopropanol (boiling point: 82.4 ° C.) Organic solvents; ester-based organic solvents such as ethyl acetate (boiling point: 77.1 ° C) and normal butyl acetate (boiling point: 126 ° C); Such systems an organic solvent. These may be used alone or in combination.

In the production of the aqueous polyester resin dispersion, a step of removing the organic solvent (solvent removal step) may be further provided after the above dispersion step. The content of the organic solvent after the desolvation step is preferably less than 1% by mass of the aqueous dispersion, more preferably less than 0.5% by mass, and further preferably less than 0.3% by mass. preferable.

The polyester resin coating solution as an organic solvent solution is produced by a method in which the polyester resin (A) is dissolved in an organic solvent.

The organic solvent for dissolving the polyester resin is not particularly limited as long as the polyester resin can be dissolved, but among the organic solvents, those having a boiling point of 180 ° C. or lower are preferable, those having a boiling point of 165 ° C. or lower are more preferable, and 150 Those having a temperature of 0 ° C. or lower are more preferable. If the boiling point of the organic solvent exceeds 180 ° C., it may be difficult to volatilize the organic solvent by drying during coating.

The polyester resin layer in the present invention preferably contains a curing agent from the viewpoint of further improving the adhesion of the polyester resin layer and improving water resistance.

Examples of the curing agent that can be used in the present invention include a polyfunctional epoxy compound; a polyfunctional isocyanate compound; a polyfunctional aziridine compound; a carbodiimide group-containing compound; an oxazoline group-containing compound; a phenol resin; and a urea resin, a melamine resin, and a benzoguanamine. Examples thereof include amino resins such as resins. You may use 1 type of these, or may use 2 or more types together. By adding a hardening | curing agent, the polyester resin layer obtained improves a water resistance while improving the adhesiveness with a polyester base material and coat resin further. Preferred curing agents are one or more curing agents selected from the group consisting of polyfunctional isocyanate compounds, carbodiimide group-containing compounds, oxazoline group-containing compounds, and melamine resins.

As the polyfunctional epoxy compound, specifically, a polyepoxy compound, a diepoxy compound, or the like can be used. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Polyglycidyl ether can be used. Examples of the diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and polypropylene glycol diester. Glycidyl ether and polytetramethylene glycol diglycidyl ether can be used.

Examples of the polyfunctional isocyanate compound include tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, metaxylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, tolylene diisocyanate and hexanetriol. Adduct, adduct 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 ' -Vitrylene-4,4 'diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate, etc. It is possible to use. Block isocyanate compounds in which these isocyanate groups are blocked with bisulfites and phenols containing sulfonic acid groups, alcohols, lactams, oximes and active methylene compounds may be used.

As the polyfunctional aziridine compound, for example, N, N′-hexamethylene-1,6-bis- (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate can be used. is there.

The carbodiimide group-containing compound is not particularly limited as long as it has at least two carbodiimide groups in the molecule. For example, compounds having a carbodiimide group such as p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (t-butylcarbodiimide), cyclohexane-1,4-bis (methylene-t-butylcarbodiimide) Alternatively, polycarbodiimide, which is a polymer having a carbodiimide group, can be used. These 1 type (s) or 2 or more types can be used.

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

Examples of phenolic resins include resol type phenolic resins and / or novolac types prepared from alkylphenols such as phenol, bisphenol A, pt-butylphenol, octylphenol, p-cumylphenol, p-phenylphenol, cresol, etc. Phenolic resins can be used.

As the urea resin, for example, dimethylol urea, dimethylol ethylene urea, dimethylol propylene urea, tetramethylol acetylene urea, 4-methoxy 5-dimethylpropylene urea dimethylol can be used.

A melamine resin is a compound having, for example, an imino group, a methylol group, and / or an alkoxymethyl group (for example, a methoxymethyl group or a butoxymethyl group) as a functional group in one molecule. As the melamine resin, an imino group-type methylated melamine resin, a methylol group-type melamine resin, a methylol group-type methylated melamine resin, a complete alkyl-type methylated melamine resin, or the like can be used. Of these, methylolated melamine resins are most preferred. Further, it is preferable to use an acidic catalyst such as p-toluenesulfonic acid in order to accelerate the thermosetting of the melamine resin.

As the benzoguanamine resin, for example, trimethylol benzoguanamine, hexamethylol benzoguanamine, trismethoxymethylbenzoguanamine, hexakismethoxymethylbenzoguanamine and the like can be used.

The polyester resin layer may contain particles for imparting easy slipping and blocking resistance.
The particle diameter of the particles that can be blended is preferably 1 nm to 2 μm, and more preferably 2 nm to 1 μm.

The type of particles that can be blended is not particularly limited as long as it does not affect the adhesion and oligomer precipitation suppression effect. Specific examples include silica, talc, mica, kaolin, swellable fluoromica, montmorillonite, hectorite, Examples thereof include calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, and carbon black. Of these, silica, talc, mica, and kaolin are preferred because they are highly effective in exhibiting heat resistance and transparency of the resulting coating, and silica is most preferred because of excellent slipperiness. Examples of the organic particles include acrylic particles, silicone particles, polyimide particles, Teflon (registered trademark) particles, crosslinked polyester particles, crosslinked polystyrene particles, crosslinked polymer particles, and core-shell particles. These particles can be used alone or in combination.

Curing agents and particles can be blended at any stage of preparing the polyester resin coating solution. For example, (1) a method of mixing and stirring a dispersion of a polyester resin (A), a dispersion of a curing agent, a dispersion of particles, and (2) a mixture of the polyester resin (A) and the curing agent in advance, Examples thereof include a method of adding a dispersion liquid of particles after adding or dispersing or dissolving in water or a solvent-based medium.

When a curing agent is used, the blending amount thereof is 1 to 10 parts by mass with respect to 100 parts by mass of the polyester resin (A) from the viewpoint of gelation of the coating liquid and cracking of the coat when stretched. It is preferably 1 to 8 parts by mass, more preferably 1 to 5 parts by mass. When blending the particles, from the viewpoint of blocking resistance and adhesiveness of the coating film, the total mass of the polyester resin (A) and the curing agent, the polyester resin (A) + the curing agent, {polyester resin (A ) + Curing agent} / particles = 99/1 to 70/30 (mass ratio), more preferably 99/1 to 80/20 (mass ratio), and 99/1 to 90/10. (Mass ratio) is more preferable.

The polyester resin coating solution may further contain other optional components. Examples of optional components that can be blended include leveling agents, antifoaming agents, other thickeners, color pigments, water, alcohol, and the like.

Examples of the leveling agent include silicone-based and fluorine-based leveling agents, and silicone-based leveling agents are particularly preferred from the viewpoint of compatibility with the coating liquid, coating suitability, adhesiveness, and blocking resistance. Examples of the silicone leveling agent include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. By using a leveling agent, it is possible to improve the wettability during coating and to improve the smoothness of the coating. The blending amount of the leveling agent is preferably 1 to 15% by mass in the polyester resin coating solution.

As the antifoaming agent, for example, an acetylene glycol compound or an ethylene oxide adduct thereof is preferable. Specifically, 3,6-dimethyl-4-decyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and compounds obtained by adding ethylene oxide to these compounds Is effective. By using an antifoaming agent, generation of bubbles mixed in the dispersion during coating can be suppressed, and the smoothness and transparency of the resulting coating can be improved. The blending amount of the antifoaming agent is preferably 1 to 10% by mass in the polyester resin coating solution.

The thickness of the polyester-based laminated film of the present invention is not particularly limited, but is preferably 15 to 150 μm. By setting the thickness to 15 to 150 μm, a film can be produced with high productivity.

In the polyester-based laminated film of the present invention, the polyester film substrate is preferably stretched in at least one direction. By being stretched, the flatness and heat resistance of the film can be improved.

In the polyester-based laminated film of the present invention, oligomer precipitation from the base film during heat treatment is suppressed. Specifically, the haze change amount when heat-treated at 150 ° C. for 1 hour is 1.0% or less. Preferably, it is 0.5% or less. Further, as a more severe condition, even when heat treatment is performed at 180 ° C. for 30 minutes, the amount of change in haze is 1.5% or less, preferably 1.0% or less.

In the present specification, the amount of change in haze is based on a value measured according to JIS-K7136: 2000.

The polyester laminated film of the present invention has good adhesion to various coat layers, particularly acrylic hard coat resins, and oligomers that precipitate during heat treatment are reduced. For this reason, it can be suitably used as an easily adhesive film for optics such as a touch panel display.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
<Evaluation of characteristics>

〔water resistant〕
The laminated film was immersed in distilled water at 25 ° C., gently pulled up after 24 hours and air-dried, and then the appearance of the resin layer was visually observed.
○: No change in appearance.
Δ: Part of the resin layer was whitened or swollen (no problem in practical use).
X: The entire resin layer was dissolved or swollen.

〔Adhesiveness〕
Acrylic hard coat resin (Seika Beam PHC manufactured by Dainichi Seika Co., Ltd.) is applied onto the polyester resin layer of the laminated film using a desktop coating device, and a low-pressure mercury lamp UV cure device (Toshiba Lighting & Technology Corp., 40 mW / cm, one Curing was performed by a lamp type) to form a hard coat layer having a thickness of 3 μm. This coating was checked for adhesion by a cross-cut method in accordance with JIS K-5600-5-6. Specifically, an adhesive tape (TF-12 manufactured by Nichiban Co., Ltd.) was applied to a film in which cuts were made to form a lattice pattern of 100 sections, and the tape was peeled off vigorously. In addition, “100/100” is the best state with no separation at 100 sections, and “0/100” indicates the state where all 100 sections are peeled off and is not the best. 100/100 to 90/100 is accepted, 100/100 to 95/100, particularly 100/100 to 98/100 is excellent, and 100/100 is the most excellent.

[Glass transition temperature of polyester resin]
10 mg of a polyester resin is weighed, and using an input-compensated differential scanning calorimeter (DSC manufactured by Perkin Elmer; Diamond DSC type, detection range: −50 ° C. to 200 ° C.) at a temperature rising rate of 10 ° C./min. Measurements were made. In the obtained temperature rise curve, the temperature at the intersection of the straight line obtained by extending the low temperature side baseline to the high temperature side and the tangent drawn at the point where the slope of the step change part of the glass transition becomes maximum is obtained. The glass transition temperature was determined.

[Change in haze]
A transparent adhesive sheet (LUCIACS CS9621T manufactured by Nitto Denko) was pasted on the non-coated surface (the surface opposite to the resin layer) of the laminated film, and based on JIS-K7136: 2000, a haze meter NDH4000 (Nippon Denshoku) was used. The haze value before the heat treatment was measured. Next, the laminated film was put into an oven heated to 150 ° C. and taken out after heat treatment for 1 hour. Thereafter, the haze value of the obtained film was measured again by the same method as described above. About the obtained film, the difference of the haze value after heat processing and before heat processing was made into the variation | change_quantity of haze.
The measurement of the amount of haze change was also performed when the heat treatment condition was changed to 180 ° C. and 30 minutes.

[Appearance (heat wrinkles)]
The appearance of the laminated film was visually observed and evaluated as follows.
○: Wrinkles are not confirmed.
Δ: Wrinkles are confirmed, but wrinkles cannot be confirmed by holding and pulling on all sides (no problem in practical use).
X: Wrinkles are confirmed, and wrinkles are confirmed even if the hand is held and pulled.

[Blocking resistance]
The laminated film is cut into a size of 50 mm × 50 mm, and the laminated film and a biaxially stretched polyethylene terephthalate (PET) film (S-50, manufactured by Unitika) are biaxially stretched with the coated surface (resin layer) of the laminated film. The layers were superposed so that they contacted the non-corona surface of the PET film, and left for 24 hours at 60 ° C. under a load of 10 kPa. After removing the load and cooling to room temperature, blocking resistance was evaluated by examining the adhesion between the resin layer and the PET film.
○: Adhesion is not recognized between the laminated films in contact.
(Triangle | delta): Although close_contact | adherence was recognized between the laminated | multilayer films which contact, it peels easily and a change, such as whitening, is not seen by the resin layer (no problem practically).
X: Between the laminated | multilayer films which contact, a resin layer raise | generates cohesive failure, or the resin layer after peeling has become white as a whole.

[Preparation of polyester resin]
Preparation Example 1
A mixture of 3057 g of terephthalic acid, 474 g of dimethyl 5-sodium sulfoisophthalate, 1154 g of ethylene glycol and 275 g of tricyclo [5.2.1.0 ^2,6 ] decanedimethanol was heated in an autoclave at 250 ° C. for 4 hours. An esterification reaction was performed. At this time, the monomer component was blended with terephthalic acid: 5-sodium sulfoisophthalate dimethyl: ethylene glycol: tricyclo [5.2.1.0 ^2,6 ] decanedimethanol = 92: 8: 93: 7 (molar ratio). ). Next, 0.525 g of antimony trioxide, 0.328 g of triethyl phosphate and 1.580 g of zinc acetate dihydrate were added as catalysts, the temperature of the system was raised to 250 ° C., and the pressure of the system was 0.4 MPa. Suppressed and reacted for 3 hours. Thereafter, the pressure was gradually released, and the reaction was performed at normal pressure for 1 hour. Thereafter, the temperature was raised to 270 ° C. and gradually decreased to 13 Pa after 1 hour. The polycondensation reaction was continued under these conditions, and the polycondensation reaction was terminated after 2 hours and 30 minutes by setting the system to normal pressure with nitrogen gas. Thereafter, the system was pressurized with nitrogen gas, and the resin was dispensed into a sheet and allowed to cool. Subsequently, the mixture was pulverized with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin (P-1) having the composition shown in Table 1.

Preparation Examples 2-5 and 8-25
The polyester resins (P-2) to (P-) are the same as the polyester resin (P-1) except that the resin composition is changed so that the resin composition after polymerization is as described in Tables 1 to 5. 5) and (P-8) to (P-25) were obtained. The results are shown in Tables 1 to 5.

Preparation Example 6
A mixture comprising 3099 g of terephthalic acid, 812 g of ethylene glycol, and 1208 g of tricyclo [5.2.1.0 ^2,6 ] decanedimethanol was heated in an autoclave at 250 ° C. for 4 hours to carry out an esterification reaction. At this time, the monomer component was blended with terephthalic acid: ethylene glycol: tricyclo [5.2.1.0 ^2,6 ] decanedimethanol = 97: 68: 32 (molar ratio). Next, 0.525 g of antimony trioxide, 0.328 g of triethyl phosphate and 1.580 g of zinc acetate dihydrate were added as catalysts, and then the temperature of the system was raised to 250 ° C., and the pressure of the system was controlled at 0.4 MPa. And reacted for 3 hours. Thereafter, the pressure was gradually released, and the reaction was performed at normal pressure for 1 hour. Thereafter, the temperature was raised to 270 ° C. and gradually decreased to 13 Pa after 1 hour. Under this condition, the polycondensation reaction was further continued for 2 hours, the system was brought to atmospheric pressure with nitrogen gas, 94 g of trimellitic anhydride was added, and the mixture was stirred at 270 ° C. for 2 hours to carry out the depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was dispensed into a sheet and allowed to cool. Next, the mixture was pulverized with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin (P-6) having the composition shown in Table 1.

Preparation Example 7
A polyester resin (P-7) was obtained in the same manner as the polyester resin (P-6) except that the resin composition was changed so that the resin composition after polymerization was as described in Table 1. The results are shown in Table 1.

In Tables 1 to 5, abbreviations indicate the following.
TPA: terephthalic acid IPA: isophthalic acid SIP: 5-sodium sulfoisophthalic acid TMA: trimellitic acid EG: ethylene glycol TCD: tricyclo [5.2.1.0 (2,6)] decanedimethanol DEG: diethylene glycol NPG: Neopentyl glycol PD: 1,2-propanediol BAEO: ethylene oxide adduct of bisphenol A

Production example 1 of polyester resin coating solution
Using a jacketed cylindrical glass container (with an internal volume of 3 L) and a stirrer (manufactured by Tokyo Science Instruments Co., Ltd., “MAZELA NZ-1200”), 300 g of polyester resin (P-1) and 50 g of isopropanol Then, 650 g of distilled water was charged in each glass container, and the temperature was raised by passing hot water into the jacket while stirring while maintaining the rotation speed of the stirring blade at 70 rpm. When the internal temperature reached 80 ° C., the temperature was raised and stirring was continued for 90 minutes. During stirring, the internal temperature was kept at 72 ± 2 ° C. Thereafter, cold water was passed through the jacket, and the rotation speed was lowered to 30 rpm and the mixture was stirred and cooled to 25 ° C. to obtain a polyester resin dispersion. 800 g of the obtained polyester resin dispersion was charged into a round bottom flask, 40 g of water was added, a mechanical stirrer and a Liebig condenser were installed, the flask was heated in an oil bath, and 40 g of an aqueous medium was distilled off at normal pressure. Thereafter, the mixture was cooled to room temperature, and further with stirring, ion-exchanged water was finally added so that the solid content concentration was 30% by mass to obtain a polyester resin dispersion.
This polyester resin dispersion and a curable aqueous dispersion (oxazoline group-containing compound, Epocros WS-700; manufactured by Nippon Shokubai Co., Ltd.) were blended so that the solid content mass ratio was 100/5, and mixed and stirred for coating. A liquid (S-1) was obtained.

Coating liquid production examples 2-31
A polyester resin coating solution (S-2) was prepared in the same manner as in Production Example 1 except that the type of polyester resin and the type and addition amount of the curing agent were changed as described in Tables 1 to 5. ) To (S-31) were obtained.

The following compounds were used as the curing agent.
Carbodilite V-02-L2 (Nisshinbo Co., Ltd.) was used as the carbodiimide group-containing compound.
Vasonate HW-100 (manufactured by BASF) was used as the polyfunctional isocyanate compound.
M-30WT (manufactured by ChangChun Plastics. Co. Ltd.) was used as the melamine resin.

[Example A, Comparative Example A (Production of Post Coat Film)]
Example A1
On the corona-treated surface of a biaxially stretched polyethylene terephthalate (PET) film (S-50, manufactured by Unitika, thickness 50 μm, Hz 3.8%), a tabletop coating device (film applicator manufactured by Yasuda Seiki Co., Ltd .; No. 542) The coating liquid (S-1) was post-coated using an AB type and a bar coater) so that the resin layer thickness after the heat drying treatment was 0.24 μm. Then, the postcoat film was obtained by making it dry for 30 seconds in the hot air dryer set to 180 degreeC.

Examples A2 to A29 and Comparative Examples A1 to A5
The coating liquid to be used was changed as shown in Tables 1 to 5 except that the thickness of the base PET film, the thickness of the polyester resin layer, and the heat drying treatment temperature were changed as shown in Tables 6 to 10. The same operation as in Example A1 was performed to obtain a post coat film.

[Example B, Comparative Example B (production of in-line coated film)]
In Example B and Comparative Example B, the following were used as the polyester resin used for the polyester film substrate.
As polyethylene terephthalate A, a polyethylene terephthalate resin in which 0.07% by mass of silica particles having a particle diameter of 2.3 μm was contained in polyethylene terephthalate B described later was used.
As the polyethylene terephthalate B, a polyethylene terephthalate resin having a polymerization catalyst of antimony trioxide, an intrinsic viscosity of 0.67, a glass transition temperature of 78 ° C., and a melting point of 253 ° C. was used.

Example B1
Polyethylene terephthalate B was introduced into extruder I (screw diameter: 50 mm) and polyethylene terephthalate A was introduced into extruder II (screw diameter: 65 mm). After melting at 280 ° C., each melt was formed into a T-die of a multilayer die. Before reaching the outlet, the layer thickness ratio (II / I / II) was 6/38/6, and the three layers were joined and laminated so that the total thickness was 1000 μm. The laminated melt was extruded from a T-die outlet, and was brought into close contact with a cooling drum whose surface temperature was adjusted to 20 ° C. to rapidly cool and solidify to obtain an unstretched film. Subsequently, after preheating with a preheating roll group whose temperature is adjusted to 90 ° C., the longitudinal speed is changed 4.0 times by changing the peripheral speed between the drawing rolls whose temperature is adjusted to 90 ° C., thereby obtaining a 250 μm thick longitudinally stretched film. It was. Next, the longitudinally stretched film was coated in-line with the coating liquid (S-1) using a Mayer bar so that the resin layer thickness after the heat drying treatment was 0.19 μm. Thereafter, the inline-coated film is guided to a tenter type stretching machine, and is stretched 5 times at a preheating temperature of 90 ° C. and a stretching temperature of 120 ° C., followed by a heat drying treatment at 230 ° C., followed by 3 in the transverse direction at 200 ° C. % Relaxation treatment. The film coming out of the tenter was wound up at a film speed of 150 m / min. Thus, a biaxially stretched polyester film having a thickness of 50 μm was obtained.

Examples B2 to B20 and B25 to B30 and Comparative Examples B1 to B5
An inline coated film was obtained in the same manner as in Example B1, except that the coating liquid used was changed as shown in Tables 1 to 5.
In Example B30, the coating liquid (S-2) was prepared so that the ratio of the silica particles (particle diameter 200 nm) to the total amount of the polyester resin and the curing agent was the value shown in Table 9. Used in a dispersed manner.

Example B31
Polyethylene terephthalate B was introduced into Extruder I (screw diameter: 50 mm), and polyethylene terephthalate A was introduced into Extruder II (screw diameter: 65 mm). After melting at 280 ° C., each melt was introduced into the outlet of the T-die. Before reaching, the layer thickness ratio (I / II) was 33/17, and the two layers were joined and laminated so that the total thickness was 1000 μm. The laminated melt was extruded from the T-die outlet of a multi-layer die, brought into close contact with a cooling drum whose surface temperature was adjusted to 20 ° C., and rapidly cooled and solidified to obtain an unstretched film. Subsequently, after preheating with a preheating roll group whose temperature is adjusted to 90 ° C., the longitudinal speed is changed 4.0 times by changing the peripheral speed between the drawing rolls whose temperature is adjusted to 90 ° C., thereby obtaining a 250 μm thick longitudinally stretched film. It was. Next, the longitudinally stretched film was coated in-line with the coating liquid (S-2) using a Mayer bar so that the resin layer thickness after the heat drying treatment was 0.19 μm. Thereafter, the inline-coated film is guided to a tenter type stretching machine, and is stretched 5 times at a preheating temperature of 90 ° C. and a stretching temperature of 120 ° C., followed by a heat drying treatment at 230 ° C., followed by 3 in the transverse direction at 200 ° C. % Relaxation treatment. The film coming out of the tenter was wound up at a film speed of 150 m / min. Thus, a biaxially stretched polyester film having a thickness of 50 μm was obtained.
In this example, the coating liquid (S-2) was prepared so that the ratio of the silica particles (particle diameter 200 nm) to the total amount of the polyester resin and the curing agent was a value shown in Table 9. Used in a dispersed manner.

Example B32
Example B31 except that the ratio of silica particles (particle diameter 200 nm) to be blended with the coating liquid (S-2) was changed as shown in Table 9 with respect to the total amount of the polyester resin and the curing agent. The same operation was performed to obtain an inline coated film.

Example B33
Polyethylene terephthalate A is put into Extruder I (screw diameter: 50 mm), melted at 280 ° C., extruded from the T-die outlet so that the thickness becomes 1000 μm, and brought into close contact with a cooling drum whose surface temperature is adjusted to 20 ° C. And solidified rapidly to obtain an unstretched film. Subsequently, after preheating with a preheating roll group whose temperature is adjusted to 90 ° C., the longitudinal speed is changed 4.0 times by changing the peripheral speed between the drawing rolls whose temperature is adjusted to 90 ° C., thereby obtaining a 250 μm thick longitudinally stretched film. It was. Next, the longitudinally stretched film was coated in-line with the coating liquid (S-2) using a Mayer bar so that the resin layer thickness after the heat drying treatment was 0.19 μm. Thereafter, the inline-coated film is guided to a tenter type stretching machine, and is stretched 5 times at a preheating temperature of 90 ° C. and a stretching temperature of 120 ° C., followed by a heat drying treatment at 230 ° C., followed by 3 in the transverse direction at 200 ° C. % Relaxation treatment. The film coming out of the tenter was wound up at a film speed of 150 m / min. Thus, a biaxially stretched polyester film having a thickness of 50 μm was obtained.
In this example, the coating liquid (S-2) was prepared with silica particles (particle diameter 200 nm) so that the ratio of the silica particles to the total amount of the polyester resin and the curing agent was the value shown in Table 9. Used in a dispersed manner.

Tables 6 to 10 show the laminated films obtained in Examples and Comparative Examples and their evaluation results.

In Examples A1 to A29 and Examples B1 to B5, B8 to B20 and B25 to B33, the obtained coating liquid had good stability, and the polyester resin layer obtained from the coating liquid Was excellent in adhesiveness, and haze value change (ΔH) accompanying heat treatment was suppressed.

In particular, in Examples A2, A3, A6 to A15, A18 to A20, A23 to A24 and A26 to A28, and Examples B2, B3, B8 to B15, B18 to B20, B26 to B28 and B30 to B33, Since the amounts of TCD and curing agent contained in each were within the optimum range, more excellent adhesion was exhibited. Furthermore, since precipitation of the oligomer accompanying the heat treatment was further suppressed, the change in haze value (ΔH) was further suppressed.

In Examples A1 to A5, A8, A11 to A15, A18 to A25 and A27 to A29 and Examples B1 to B5, B8, B11 to B15, B18 to B20, B25 and B27 to B33, they are contained in the coating film. Both the amount of SIP and curing agent was more appropriate and therefore showed higher water resistance. In particular, in Example B described above, good stretchability was obtained.

In particular, in Examples B1 to B5, B8 to B20, and B25 to B29, the polyester resin was compared with Examples A1 to A5, A8 to A20, and A25 to A29 by heat drying treatment at a high temperature in the in-line process. The adhesion of the layer was further improved.

On the other hand, in Comparative Examples A1 and A4, since the TCD component in the diol component of the polyester resin (A) was too much, the adhesiveness was lowered.

In Comparative Examples A2 and B2, Comparative Examples A3 and B3, and Comparative Examples A5 and B5, since the TCD component in the diol component of the polyester resin (A) was too small, the change in haze value (ΔH) accompanying the heat treatment was significantly large. It was.

The laminated film of the present invention is useful as an electronic material, an optical material, or an electro-optical material.

Claims

A laminated film having a polyester resin layer on at least one surface of a polyester film substrate, wherein 5 to 70 mol% of a diol component of the polyester resin constituting the polyester resin layer is a diol component having a tricyclodecane structure; A laminated film having a haze change amount of 1.0% or less when heat-treated at 150 ° C. for 1 hour.
The laminated film according to claim 1, wherein 0.1 to 15 mol% of the dicarboxylic acid component of the polyester resin constituting the polyester resin layer is a dicarboxylic acid component having a sulfonate group.
The laminated film according to claim 2, wherein 3 to 8 mol% of the dicarboxylic acid component of the polyester resin constituting the polyester resin layer is a dicarboxylic acid component having a sulfonate group.
The laminated film according to any one of claims 1 to 3, wherein the polyester resin layer further contains a curing agent, and the content of the curing agent is 1 to 10 parts by mass with respect to 100 parts by mass of the polyester resin.
The production of a laminated film according to any one of claims 1 to 4, wherein after the coating liquid containing the polyester resin is applied to a polyester film substrate, a heat drying treatment is performed at a temperature of 180 ° C or higher. Method.
6. The method for producing a polyester-based laminated film according to claim 5, wherein the polyester film substrate coated with the coating liquid is stretched in at least one direction.