JP2015040318A - Deposition film and inorganic thin film laminate film comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film for vapor deposition having excellent adhesiveness, moist heat resistance and durability to an inorganic thin film, and to provide an inorganic thin-film laminated film produced therefrom.SOLUTION: In a film for vapor deposition having a coating layer with a thickness of 5 nm or more formed of a composition containing (A) a hydroxy group-containing acrylic copolymer and (B) a polyglycidylamine compound at least on one surface of a polyester film, a haze value of the polyester film on which the coating layer is formed is 10% or lower, and an inorganic thin film is formed on the coating layer surface side.

Description

  The present invention relates to a vapor deposition film and an inorganic thin film laminated film comprising the same, and more specifically, for example, a vapor deposition film having excellent adhesion, moisture heat resistance, and durability to an inorganic thin film called metal vapor deposition, transparent vapor deposition, and the like. The present invention relates to an inorganic thin film laminate film comprising the same.

  Polyester films, especially biaxially stretched films of polyethylene terephthalate, are used as base materials for various industrial materials because they have excellent mechanical properties, heat resistance, chemical resistance, etc. As a member around a flat panel display and a solar cell, the demand for the material can be significantly increased as a flexible and lightweight material that can replace conventional glass. However, since the polyester film has crystal orientation, it has high surface cohesion and poor adhesion to various counterpart materials.

Therefore, in order to improve the surface properties of the polyester film, it is known that a primer layer is provided by applying an easy-adhesive coating on a biaxially stretched polyester film. Polyurethanes, copolyesters, etc. are used, and acrylic copolymers are also known. (Patent Document 1 etc.).
Such polyurethane or copolyester may block the films due to changes in temperature and humidity during storage, or the adhesiveness may deteriorate in a high temperature and high humidity environment over a long period of time. Further, Patent Document 1 uses an acrylic copolymer as a primer and aims to improve adhesion to various paints, inks, toners and the like.

  On the other hand, members such as a solar battery backsheet are required to have gas barrier properties and long-term durability. Patent Document 2 discloses a composite laminated structure using a transparent vapor-deposited film on which an inorganic compound is vapor-deposited as a constituent material. A backsheet is described. In Patent Document 2, it is proposed that the fluororesin is modified in order to enhance the adhesion between the fluororesin and the transparent vapor deposition film, and the fluororesin and the transparent vapor deposition film are bonded by thermal bonding without using an adhesive. . However, examination about the adhesiveness of the inorganic compound vapor deposition layer and transparent film which comprise a transparent vapor deposition film is not made | formed.

JP-A-2-248435 JP 2010-109038 A

  When the polyester film on which the inorganic thin film is deposited is used for a long period of time such as a solar cell in a severe environment such as temperature and humidity, the adhesiveness between the inorganic thin film and the polyester film is changed over time. It was found that the moisture and heat resistance and durability when used for a long time under high temperature and high humidity are not sufficient. The present invention has been made for the purpose of solving such problems, and provides a polyester-based vapor deposition film having excellent adhesion, heat-and-moisture resistance and durability to an inorganic thin film, and an inorganic thin film laminated film comprising the same. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have conventionally applied a coating layer containing a hydroxyl group-containing acrylic copolymer that has not been studied as an easy-adhesion layer with an inorganic thin film to at least one surface of a polyester film. By providing, it discovered that the film for vapor deposition which has the outstanding long-term adhesiveness, wet heat resistance, and durability with respect to inorganic thin films, such as metal vapor deposition and transparent vapor deposition, can be provided.

  That is, an object of the present invention is to have a coating layer having a thickness of 5 nm or more formed of a composition containing (A) a hydroxyl group-containing acrylic copolymer and (B) a polyglycidylamine compound on at least one side of a polyester film, The haze value of the polyester film on which the coating layer is formed is 10% or less, and is achieved by a vapor deposition film in which an inorganic thin film is formed on the coating layer surface side.

Furthermore, according to this invention, as a preferable aspect of the film for vapor deposition of this invention, the thickness of this application layer is 5-200 nm, and the melting subpeak temperature Tsm of this film for vapor deposition is 200 degreeC or more and 240 degrees C or less. Also included is a film comprising at least one of the polyester constituting the polyester film being polyethylene terephthalate or polyethylene-2,6-naphthalate.
The present invention also includes an inorganic thin film laminated film in which an inorganic thin film is formed on the coating layer surface side of the vapor deposition film of the present invention, and further has an undercoat layer on the coating layer surface side of the vapor deposition film of the present invention, An inorganic thin film laminated film in which an inorganic thin film is formed on the surface of the undercoat layer is also included.

  The film for vapor deposition of the present invention suppresses the deterioration in adhesiveness over time at the interface between the inorganic thin film and the polyester film, and is excellent in moisture and heat resistance and durability when used for a long time under high temperature and high humidity. The inorganic thin film laminated film of the present invention can be suitably used as a film for vapor deposition formed on a polyester film, and is useful for gas barrier films such as solar cells and flexible displays that are used for a long time under high temperature and high humidity.

Hereinafter, the present invention will be described in detail.
(Polyester film)
The polyester constituting the polyester film of the present invention is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of such polyester include polyethylene Terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylene dimethylene terephthalate), polyethylene-2,6-naphthalate, etc., and copolymers thereof and a small proportion of other resins The blend of etc. is also included. Among these polyesters, polyethylene terephthalate or polyethylene-2,6-naphthalate is preferable, and polyethylene-2,6-naphthalate is more preferable from the viewpoint of heat-resistant dimensional stability when depositing an inorganic thin film.

A small amount of inorganic or organic particles can be added to the polyester film of the present invention in order to improve slipperiness. Examples of such particles include inorganic particles such as silica, calcium carbonate, aluminum silicate, titanium oxide, barium sulfate, and alumina, and organic particles such as acrylic resin, silicone, benzoguanamine, Teflon (registered trademark), and epoxy. Particles are preferred, and bulk silica particles or agglomerated silica particles are particularly preferred. The average particle size of the particles is preferably from 0.1 to 3.0 μm, more preferably from 0.5 to 2.0 μm, still more preferably from 1.0 to 2.0 μm.
In addition to the particles, the polyester film of the present invention may contain a surfactant such as polyethylene glycol (PEG) or sodium dodecylbenzenesulfonate or an antistatic agent.
Such a polyester and, if necessary, additives such as particles are melt-extruded by a conventional method to form a film, and as described below, orientation crystallization by stretching and crystallization by heat treatment are used to form the base film of the present invention. A polyester film is obtained.

In the present invention, the thickness of the polyester film is not particularly limited, but is preferably 5 to 300 μm, and more preferably 10 to 100 μm. If the lower limit is not satisfied, the handling property may not be sufficient, while if the upper limit is exceeded, the deposition suitability when depositing the inorganic thin film may be lowered.
The polyester film of the present invention is obtained by melt-extruding polyester into a film form from a slit die, cooling and solidifying with a casting drum to form an unstretched film, and stretching the obtained unstretched film at least in a uniaxial direction, preferably in a biaxial direction. Any of a sequential biaxial stretching method and a simultaneous biaxial stretching method may be used.

  In the case of the sequential biaxial stretching method, for example, an unstretched film is heated by roll heating, infrared heating, etc., and stretched in the longitudinal direction (sometimes referred to as a continuous film forming direction, MD direction, longitudinal direction, etc.). To obtain a longitudinally stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The stretching temperature is preferably in the range of the glass transition point (Tg) to (Tg + 70) ° C. of the polyester. The film after longitudinal stretching is then stretched in the film width direction (which may be referred to as the longitudinal and vertical directions, the TD direction, the transverse direction, etc.), and then subjected to treatment such as heat setting and heat relaxation as necessary. Thus, a biaxially oriented film is obtained. The stretching temperature in the width direction is preferably higher than Tg, and is preferably carried out while raising the temperature continuously or stepwise within the range of (Tg + 5) to (Tg + 70) ° C.

The stretching ratio is preferably 2.8 to 4.5 times in both the longitudinal direction and the width direction, more preferably 3.0 to 4.0 times, and still more preferably 3.0 to 3.8 times. If the draw ratio is less than the lower limit, uneven thickness of the film may be noticeable, and if the draw ratio exceeds the upper limit, the thermal shrinkage rate becomes large, which may affect the film dimension change during processing.
After stretching in the width direction, it is preferable to further heat-set, and if necessary, both ends are supported by clips or the like, at a temperature of (Tm-55) to (Tm-20) ° C., constant width or 10% or less A method of heat-fixing for 5 seconds or more with a decrease in width may be used. With this method, the thermal shrinkage rate in the width direction can be further reduced. Moreover, heat contraction rate and thickness spots can be adjusted by performing heat treatment in such a temperature range. Moreover, you may use the method of adjusting the taking-up speed | rate of a film longitudinal direction after heat fixing as needed, and relaxing in a longitudinal direction.

(Coating layer)
The film for vapor deposition of the present invention has a coating layer having a thickness of 5 nm or more formed of a composition containing (A) a hydroxyl group-containing acrylic copolymer and (B) a polyglycidylamine compound on at least one surface of the polyester film. By having such a coating layer, when the film of the present invention is used as an inorganic thin film laminated film having an inorganic thin film on at least one side of the polyester film, the adhesive property between the polyester film and the inorganic thin film over a long period of time in an environment of high temperature and high humidity. Is maintained, and has the effect of being excellent in moisture and heat resistance and durability.

In the present invention, the (A) hydroxyl group-containing acrylic copolymer used for forming the coating layer is preferably a hydroxyl group-containing (meth) acrylic acid ester copolymer, and has a secondary transition point of 20 to 95 ° C. More preferred is a (meth) acrylic acid ester copolymer. Moreover, it is preferable that the hydroxyl-containing acrylic copolymer in this invention does not have a free carboxyl group.
Such a hydroxyl group-containing (meth) acrylic acid ester copolymer is obtained by copolymerizing a mixture of a hydroxyl group-containing (meth) acrylic acid ester monomer and another monomer copolymerizable with the hydroxyl group-containing (meth) acrylic acid ester monomer by a conventional method. It can be produced by polymerization.

  As the hydroxyl group-containing (meth) acrylic acid ester monomer, that is, a compound having one or more hydroxyl groups and polymerizable unsaturated bonds in one molecule, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate , 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 4-hydroxybutyl (meth) acrylate, 1,4-cyclohexane Examples include alicyclic (meth) acrylates having a hydroxyl group such as dimethanol monoacrylate, and hydroxyalkyl (meth) acrylates having an aromatic chain such as 2-hydroxy-3-phenoxypropyl acrylate. May be used in combination, or two or more Germany.

  Examples of other monomers copolymerizable with the hydroxyl group-containing (meth) acrylic acid ester monomer include, for example, alkyl (meth) acrylate (wherein the alkyl group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n- Butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.); (meth) acrylamide, N-alkyl (meth) acrylamide and N, N-dialkyl (meth) acrylamide (wherein the alkyl group is Methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.), N-alkoxymethyl (meth) acrylamide and N, N -Dialkoxymethyl (meth) acrylamide (wherein the alkoxy group is Amide group-containing monomers such as xy group, ethoxy group, butoxy group, isobutoxy group, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, N-phenyl (meth) acrylamide; glycidyl (meth) Epoxy group-containing monomers of acrylate; monomers such as vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, alkyl maleic acid monoester, acrylonitrile, methacrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene It is done.

  The main component of the monomer constituting the hydroxyl group-containing acrylic copolymer is at least one of methyl methacrylate (hereinafter sometimes referred to as MMA) and ethyl acrylate (hereinafter sometimes referred to as EA). Is preferred. Especially, it is preferable that the ratio (MMA / EA ratio) of methyl methacrylate and ethyl acrylate is in the range of 0.5 to 3 in terms of molar ratio, and more preferably in the range of 0.7 to 2.

  The total amount of MMA and EA is preferably 50 to 98 mol%, more preferably 80 to 96 mol%, based on the total amount of monomers constituting the hydroxyl group-containing acrylic copolymer in the present invention. . The amount of the hydroxyl group-containing monomer is preferably 0.5 to 15 mol%, more preferably 1 to 10 mol% based on the total amount of monomers constituting the hydroxyl group-containing acrylic copolymer.

  The hydroxyl group-containing acrylic copolymer in the present invention preferably has a secondary transition point of 20 to 95 ° C, more preferably 30 to 70 ° C, and still more preferably 40 to 70 ° C. When the secondary transition point of the hydroxyl group-containing acrylic copolymer is less than the lower limit, the coating layer has adhesiveness and a blocking phenomenon between films may occur. On the other hand, when the secondary transition point is higher than the upper limit, the coating layer becomes hard and brittle, and the adhesion to the polyester film may be lowered.

  In the present invention, (B) a polyglycidylamine compound is used as a crosslinking agent used together with (A) a hydroxyl group-containing acrylic copolymer. The polyglycidylamine compound is a compound having at least one tertiary amino group and two or more glycidyl groups in one molecule, and is represented by the following formulas (1), (2), (3) Is exemplified.

  In addition to these compounds, an aqueous solution such as trimethylolpropane triglycidyl ether or glycerin triglycidyl ether or a water-dispersible polyglycidyl compound can be used in combination within a range of 50% by weight or less of the total amount of component (B). .

  Further, as the composition of the coating layer in the present invention, it is possible to use a compound (reaction promoting compound) that accelerates the reaction between (A) the hydroxyl group of the hydroxyl group-containing acrylic copolymer and (B) the glycidyl group of the polyglycidylamine compound. it can. Examples of the reaction promoting compound include a tertiary amino group-containing compound, a compound having a nitrogen-containing ring structure and a salt thereof, and a quaternary ammonium salt compound. Specific examples include tri-n-butylamine, dimethylaminobenzene, 2,4,6-tris (dimethylaminomethyl) phenol, 2-methylimidazole, 1,8-diazo-bicyclo (5,4,0). Examples include undecene-7 and tetramethylammonium chloride.

  In the composition constituting the coating layer, the content of (A) hydroxyl group-containing acrylic copolymer and (B) polyglycidylamine compound is 60 to 99% by weight of component (A) based on the weight of the composition, B) is preferably 1 to 40% by weight, more preferably component (A) is 70 to 98% by weight, and component (B) is preferably 2 to 30% by weight.

  The thickness after drying of the coating layer provided on the polyester film is 5 nm or more, preferably 5 to 200 nm, more preferably 10 to 100 nm, and further preferably 20 to 50 nm. If the thickness of the coating layer is less than the lower limit, the effect of improving the adhesion between the inorganic thin film and the polyester film is not sufficiently exhibited. On the other hand, when the thickness of the coating layer exceeds the upper limit, blocking between the films may occur when the polyester film on which the coating layer is formed is wound into a roll.

The coating layer in the present invention is a coating liquid containing the layer forming component, preferably an aqueous liquid is coated on a polyester film, and at least the component (A) is heated by heating during the film forming process such as stretching, drying, and heat treatment. A part is crosslinked and formed with component (B).
The coating liquid is preferably an aqueous liquid such as an aqueous solution or a water emulsion liquid. When used in an aqueous liquid, a slight amount of an organic solvent may be contained for stabilizing the dispersion of the solid component. This aqueous coating solution is obtained by dissolving or dispersing component (A) and component B as essential components in an aqueous medium, but a catalyst and a leakage agent may be added as necessary.
Examples of leaking agents include anionic, cationic and nonionic surfactants. Among these surfactants, those that make the surface tension of the aqueous liquid 40 dyne / cm or less and promote leakage of the polyester film are preferable. For example, polyoxyethylene alkyl phenyl ether, polyoxyethylene-fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfonate, quaternary amine salt, betaine type surfactant and the like can be mentioned. Moreover, you may use together an antistatic agent, a ultraviolet absorber, a pigment, an organic filler, an inorganic filler, a lubricant, an antiblocking agent etc. within the range which does not inhibit the objective of this invention.

  The step of applying the aqueous coating solution to the polyester film is preferably performed on the surface of the polyester film immediately after the polyester is melt-extruded and cast, or immediately after being stretched in either the vertical or horizontal direction. As a generally performed method, an aqueous coating solution is applied onto a uniaxial film stretched in the longitudinal direction, followed by transverse stretching while heating, and further heat-fixing the film at a high temperature and at least component (A) of the coating layer. There is a method in which a part is crosslinked with component (B) and heat-cured. An aqueous coating layer is applied on an unstretched film, followed by simultaneous biaxial stretching in the vertical and horizontal directions while heating and drying, and further at a high temperature. A method of thermally fixing the coating layer and thermally curing the coating layer may be used.

As a method of applying the coating layer on the polyester film, a known method can be applied. For example, a spray coating method, an air knife method, a reverse coating method, a kiss coating method, a gravure coating method, a Meyer bar method, a roll brush method, and the like can be applied. The concentration of the applied coating liquid varies depending on the coating method, but is generally 0.5 to 50% by weight. Moreover, it is preferable that a coating amount is 1-20 g / m < ² > by wet amount.

(Deposition film)
In this invention, this polyester film in which this application layer was formed is called a film for vapor deposition, an inorganic thin film is formed in this application layer surface side, and an inorganic thin film laminated film is obtained.
In the present invention, the haze value of the polyester film on which the coating layer is formed is 10% or less, preferably 8% or less, more preferably 6% or less, and further preferably 5% or less. When the haze value exceeds the upper limit, the adhesiveness after the wet heat treatment is lowered, and the adhesive effect by the coating layer having the composition of the present invention is not sufficiently exhibited.
Such haze characteristics can be obtained by not using an additive such as particles or pigments in the polyester film or by limiting the content so as to be within the haze value when used. The upper limit of the amount of addition varies depending on the type of additive, but in the case of massive silica particles or aggregated silica particles, it is 0.2% by weight or less, preferably 0.1% by weight or less based on the film weight. In addition, since spherical silica particles tend to have high haze, when they are used, they are limited to less than 0.05 wt%.

  The film for vapor deposition of the present invention preferably has a melting subpeak temperature Tsm of 200 ° C. or higher and 240 ° C. or lower, and more preferably 210 ° C. or higher and 230 ° C. or lower. If the melting sub-peak temperature is less than the lower limit, the delamination resistance may not be sufficient. On the other hand, if it exceeds the upper limit, the thickness unevenness tends to deteriorate.

(Inorganic thin film)
The film for vapor deposition of the present invention has a coating layer formed of a composition containing (A) a hydroxyl group-containing acrylic copolymer and (B) a polyglycidylamine compound on at least one surface of the polyester film, and the coating layer surface side. By using the coating layer having the structure of the present invention, the high adhesion between the polyester film and the inorganic thin film is maintained over a long period of time even when used at high temperature and high humidity for a long time. It is possible to provide a deposition film that is maintained and has heat and humidity resistance and durability.
As the inorganic thin film, those having gas barrier performance are preferable, and metal oxides such as silicon oxide, aluminum oxide, tin oxide, zinc oxide, magnesium oxide and mixtures thereof are preferably exemplified.
Such an inorganic thin film is formed on the coating layer surface of the present invention by a known vapor deposition method.

(Underlayer)
In forming the inorganic thin film on the coating layer side of the vapor deposition film of the present invention, a configuration in which the inorganic thin film is directly formed on the coating layer surface of the vapor deposition film is preferable, and as another preferred configuration, the coating of the vapor deposition film is preferable. A configuration in which an undercoat layer is further provided on the layer surface side and an inorganic thin film is formed on the undercoat layer surface is also exemplified. By further having an undercoat layer, the adhesiveness between the polyester film and the inorganic thin film is further increased, and the adhesiveness can be maintained for a long period of time in an environment of high temperature and high humidity.

The undercoat layer is preferably formed of a composition containing a urethane compound or a silane coupling agent, and examples of the urethane compound include a urethane compound containing a urethane bond formed by an addition reaction between an isocyanate group and a hydroxyl group. Specific examples include urethane compounds obtained by reacting a compound having a hydroxyl group such as polyurethane polyol, polyester polyol, polyether polyol, and acrylic polyol with an isocyanate compound having an isocyanate group such as triidyl isocyanate.
Examples of the silane coupling agent include an epoxy silane coupling agent, an amino silane coupling agent, a methacrylic silane coupling agent, and a ureido silane coupling agent. Of these, epoxy-based silane coupling agents are preferred.
Various curing accelerators, reaction catalysts, fillers and the like may be added to the composition of the undercoat layer.

  Examples of the method for forming the undercoat layer include a method in which a coating solution obtained by dissolving the composition constituting the undercoat layer in an organic solvent is applied on the surface of the coating layer and dried by heating. As the coating method, a known method such as a gravure method can be used, and the thickness after drying is preferably from 0.01 to 10 μm, and more preferably from 0.05 to 5 μm.

(Inorganic thin film laminated film)
In the present invention, an inorganic thin film laminated film in which an inorganic thin film is formed on the coating layer surface side of the vapor deposition film of the present invention, and as another preferred embodiment, a composition containing a urethane paint on the coating layer surface side of the vapor deposition film of the present invention Also included is an inorganic thin film laminated film having an undercoat layer formed with an inorganic thin film formed on the surface of the undercoat layer, and high adhesion between a polyester film and an inorganic thin film even when used for a long time under high temperature and high humidity Is maintained over a long period of time and has heat and humidity resistance and durability, and is therefore useful as a base material for flexible gas barrier materials constituting solar cells and flexible flat panel displays (sometimes referred to as flexible displays).

Hereinafter, the present invention will be described in detail with reference to examples. Various measurements were performed using the following methods.
(1) Adhesive evaluation after wet heat treatment On the coating layer surface of the obtained biaxially stretched film, an equimolar mixture of silicon and silicon dioxide was used as a vapor deposition material with a high frequency induction heating type continuous vapor deposition machine, and the degree of vacuum was 1 × 10 ^−4. Vapor deposition was performed at ˜2 × 10 ⁻⁴ mmHg to form a vapor-deposited film (inorganic thin film) made of transparent silicon oxide having a thickness of about 50 nm, thereby preparing an inorganic thin film laminated film.
An unstretched polypropylene film (trade name P1153 manufactured by Toyobo Co., Ltd.) having a thickness of 70 μm was applied to the inorganic thin film surface (deposition surface) of this inorganic thin film laminated film as an adhesive / curing agent for dry lamination (trade name TM-250HV manufactured by Toyo Morton Co., Ltd.). / CAT-RT86) is used, and the unstretched polypropylene film surfaces of the obtained laminated film are heat sealed at 150 ° C. to prepare a sample of 15 cm length × 10 cm width, temperature 121 ° C., pressure After processing for 50 hours under the conditions of 2.0 kg / cm ² and humidity of 100% RH, the sample was cut to a width of 15 mm to prepare a strip-like sample of 15 cm length × 15 mm width.
Table 1 shows the results of measuring the peel strength between the polyester film and the deposited film on the obtained sample using a peel tester (a tensile tester manufactured by Toyo Seiki Co., Ltd., apparatus name “Strograph M1 type”).
If the peel strength after such wet heat treatment is 5 N / 15 mm or more, it has the long-term durability which is the subject of the present invention.

(2) Blocking property The polyester film on which the coating layer is formed is cut into a length of 15 cm × 10 cm, the coated surfaces are overlapped, and a load of 50 kg / cm ² is applied and the load is maintained at 50 ° C. for 16 hours. The results of measuring peel strength in the width direction (along the long piece) are shown in Table 1. The peel strength was measured using the same peel tester as the measurement method (1) (a tensile tester manufactured by Toyo Seiki Co., Ltd., device name “Strograph M1 type”).
If the peel strength is 20 g / 10 cm or less, it is good. If the peel strength exceeds 20 g / 10 cm, or if the sample breaks during measurement, the peel strength is poor.

(3) Haze value According to JIS K7361, a haze value of a film sample with a coating layer (Comparative Example 6 has no coating layer) using a haze meter (trade name “NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd.) Was measured.

(4) Melting sub-peak temperature (Tsm)
About 20 mg of a film sample with a coating layer (Comparative Example 6 has no coating layer) is sealed in an aluminum pan for measurement and attached to a differential calorimeter (TA Instruments, DSCQ100), and 25 ° C. to 20 ° C./min. The temperature was raised to 300 ° C. at a rate, and the melting subpeak temperature (Tsm) observed on the lower temperature side than the melting point was measured.

(5) Film thickness The average value which measured 10 point | piece thickness for the film sample with an application layer using the electric micrometer (Anritsu K-402B) was made into film thickness.

(6) Coating layer thickness, undercoat layer thickness The film was cut into a triangle, fixed to an embedded capsule, and then embedded in an epoxy resin. Then, the embedded sample was made into a thin film section having a thickness of 50 nm by a microtome (ULTRACUT-S), and then a transmission electron microscope (JEOL JEM2010) was used at an acceleration voltage of 100 kV. The film was observed and photographed, and the thicknesses of the coating layer and the undercoat layer were measured at 10 points from the photograph, and each layer thickness was obtained by averaging.

[Examples 1 to 7 and Comparative Examples 1 to 4]
A polyethylene terephthalate composition containing 0.08% by weight of massive silica particles having an average particle diameter of 1.7 μm is charged into an extruder, extruded onto a cooling drum, rapidly cooled and solidified to form an unstretched film, The stretched film was stretched 3.7 times in the longitudinal direction, and then the coating layer coating liquid composition (% by weight) shown in Table 1 was applied to one side of the uniaxially stretched film by a gravure coating method. Next, after drying the coating liquid at 100 ° C., the film is stretched 3.9 times in the transverse direction, and then heat-set at 220 ° C. to obtain a biaxially stretched film (inherent viscosity 0.62) having a coating layer thickness of 50 μm. It was. The properties of the obtained film are as shown in Table 1, and had good adhesiveness even after wet heat treatment.
In addition, each example had good gas barrier properties not only in the initial stage but also after the durability test.

[Example 8]
A polyethylene-2,6-naphthalate composition containing lump silica particles having an average particle diameter of 1.7 μm in an amount of 0.08% by weight is charged into an extruder, extruded onto a cooling drum, rapidly cooled and solidified, and unstretched. The unstretched film was stretched 3.7 times in the longitudinal direction, and then the coating layer coating liquid composition (% by weight) shown in Table 1 was applied to one side of the uniaxially stretched film by a gravure coating method. Next, after drying the coating solution at 100 ° C., it is stretched 3.9 times in the transverse direction, and then heat-set at 235 ° C. to obtain a biaxially stretched film (inherent viscosity 0.61) with a coating layer of 50 μm thickness. It was. The properties of the obtained film are as shown in Table 1, and had good adhesiveness even after wet heat treatment. This example also had good gas barrier properties not only in the initial stage but also after the durability test.

[Example 9]
On the surface of the coating layer of the biaxially stretched film with a coating layer obtained in Example 2, an urethane paint (mixed so that the hydroxyl groups of acrylic polyol and the isocyanate groups of triidyl isocyanate are equivalent in ethyl acetate solvent) A film with an undercoat layer was obtained by providing a film having a dry thickness of 200 nm by a roll coating method. The characteristics of the obtained film are as shown in Table 1. Even after wet heat treatment, the film had very good adhesion. This example also had good gas barrier properties not only in the initial stage but also after the durability test.

[Example 10]
On the surface of the coating layer of the biaxially stretched film with the coating layer obtained in Example 2, an epoxy silane coupling agent (3-glycidoxypropyltrimethoxysilane was adjusted to a concentration of 10 wt% with an ethyl acetate solvent) A film with an undercoat layer was obtained by providing a mixture of 100 ppm of iron acetylacetonate as a reaction catalyst so as to have a dry film thickness of 200 nm by a roll coating method. The characteristics of the obtained film are as shown in Table 1. Even after wet heat treatment, the film had very good adhesion. This example also had good gas barrier properties not only in the initial stage but also after the durability test.

[Comparative Example 5]
A biaxially stretched polyethylene terephthalate film was obtained in the same manner as in Example 2, except that a polyethylene terephthalate composition containing 0.2% by weight of true spherical silica particles having an average particle size of 2.0 μm was used. . The characteristics of the obtained film are as shown in Table 1, and are unsuitable for use in applications requiring high haze values and transparency, and low adhesiveness after wet heat treatment. It is unsuitable for applications that require durability.

[Comparative Example 6]
A biaxially stretched polyethylene terephthalate film was obtained in the same manner as in Example 1 except that no coating layer was formed on the film.

In Table 1, the acrylic resins A to C, the crosslinking agents D to G, and the wetting material are as follows.
In Table 1, PET represents polyethylene terephthalate, and PEN represents polyethylene-2,6-naphthalate.

・ Acrylic resin A
Prepared according to the method described in Preparation Examples 1 to 3 of JP-A-63-37167, methyl methacrylate 50 mol% / ethyl acrylate 40 mol% / 2-hydroxyethyl methacrylate 5 mol% / N-methylol acrylamide An aqueous dispersion (solid content 25% by weight) of a hydroxyl group-containing acrylic copolymer (Tg = 30 ° C., molecular weight 390000) composed of a monomer composition ratio of 5 mol% was obtained.
・ Acrylic resin B
Similar to the acrylic resin A, a hydroxyl group-containing acrylic copolymer having a monomer composition ratio of methyl methacrylate 50 mol% / ethyl acrylate 40 mol% / 4-hydroxybutyl acrylate 5 mol% / N-methylol acrylamide 5 mol% An aqueous dispersion (Tg = 25 ° C., molecular weight 410000) (solid content 25% by weight) was obtained.
・ Acrylic resin C
Similarly to the acrylic resin A, a carboxyl group-containing acrylic copolymer (Tg = 45 ° C.) composed of 50% by mole of methyl methacrylate / 40% by mole of ethyl acrylate / 5% by mole of methacrylic acid / 5% by mole of N-methylolacrylamide , A molecular weight of 380000) was obtained (solid content 25% by weight).
・ Crosslinking agent D
N, N, N ′, N′-tetraglycidyl m-dimethylcyclohexanediamine / crosslinking agent E
N, N, N ′, N′-tetraglycidyl m-xylenediamine / crosslinking agent F
Polyglycerol polyglycidyl ether / crosslinking agent G
Glycerol polyglycidyl ether / wetting agent Polyoxyethylene (n = 7) lauryl ether (trade name “Naroacty N-70” manufactured by Sanyo Chemical Co., Ltd.)

  The film for vapor deposition of the present invention suppresses the deterioration in adhesiveness over time at the interface between the inorganic thin film and the polyester film, and is excellent in moisture and heat resistance and durability when used for a long time under high temperature and high humidity. The inorganic thin film laminated film of the present invention can be suitably used as a film for vapor deposition formed on a polyester film, and is useful for gas barrier films such as solar cells and flexible displays that are used for a long time under high temperature and high humidity.

Claims (6)

  The polyester film has a coating layer having a thickness of 5 nm or more formed of a composition containing (A) a hydroxyl group-containing acrylic copolymer and (B) a polyglycidylamine compound on at least one side of the polyester film. A haze value of a polyester film is 10% or less, and an inorganic thin film is formed on the coating layer surface side.   The film for vapor deposition according to claim 1, wherein the coating layer has a thickness of 5 to 200 nm.   The film for vapor deposition according to claim 1 or 2, wherein a melting subpeak temperature Tsm of the film for vapor deposition is 200 ° C or higher and 240 ° C or lower.   The film for vapor deposition according to any one of claims 1 to 3, wherein the polyester constituting the polyester film is polyethylene terephthalate or polyethylene-2,6-naphthalate.   The inorganic thin film laminated film in which the inorganic thin film was formed in this application layer surface side of the film for vapor deposition in any one of Claims 1-4.   The inorganic thin film laminated film which has an undercoat layer further in this application layer surface side of the film for vapor deposition in any one of Claims 1-4, and the inorganic thin film was formed in this undercoat layer surface.