JP6044698B2 - Easy-adhesive film and method for producing the same - Google Patents

Description

  The present invention relates to an easily adhesive film. Specifically, the present invention relates to an easy-adhesive film that achieves both excellent coat appearance when used in a solar cell backsheet and adhesion with a sealing material over time.

  In recent years, solar cells have attracted attention as an energy means to replace petroleum energy that causes global warming, and the demand for solar cells has increased. A solar cell is a solar power generation system that directly converts solar energy into electricity. As a solar cell element, semiconductors such as single crystal silicon, polycrystalline silicon, and amorphous silicon, compound-based materials, and organic dyes are used. Yes. Recently, the ratio of thin-film solar cell elements in which the thickness of silicon is reduced in order to reduce raw materials, energy required for production, and costs has been increasing. In order to protect such elements over a long period of time (approximately 20 years or more), such a solar cell element is generally wired in series or in parallel with several to several tens of solar cell elements. Done and unitized. A unit incorporated in this package is called a solar cell module.

  Here, a solar cell module generally covers a surface to which sunlight is applied with glass, fills a gap with a sealing material for a solar electronic element, and has a plurality of layers such as a heat-resistant and weather-resistant plastic material called a back sheet on the back surface. It is the structure protected by the protective sheet which consists of a structure. As a sealing material filling the solar cell element, an olefin resin such as ethylene / vinyl acetate copolymer resin (hereinafter EVA) or polyvinyl butyral resin (hereinafter PVB) is used. Using these sealing materials, a module is produced by superposing the glass substrate / sealing material / solar cell element / sealing material / back sheet and then heat-pressing with a vacuum laminator or the like. The sealing material has a role of adhering and fixing the solar cell element, preventing moisture from entering from the outside, and protecting the solar cell element.

  As a solar cell backsheet, from the solar cell element side (encapsulant side) to polyester film / adhesive / polyester film (colored) / metal or metal oxide thin film layer (moisture-proof layer) / adhesive / fluorine Those having a laminated structure such as a film (antifouling layer) have been proposed. In a conventional solar cell module using amorphous silicon as a solar cell element, a black polyester film is used as the polyester film on the sealing material side (see Patent Document 1). This is because the output decrease due to the temperature rise is small, rather the output is expected to increase by maintaining the high temperature, and the solar cell element and the back sheet are unified in black, so that the design is excellent.

  Such a back sheet has a role of protecting the solar cell element from external moisture and contamination over a long period of time. Therefore, the adhesion between the black polyester film on the solar cell element side that is in direct contact with the sealing material and the sealing material is important. However, the surface untreated black polyester film cannot obtain sufficient adhesiveness and is required to be improved. Providing an adhesive layer containing a resin or a crosslinking agent has been proposed as a method for improving the adhesion between the polyester film and the sealing material (see Patent Documents 1 to 3).

  However, in the case where an adhesive layer is provided on the black polyester film by these measures, there is a problem that it is difficult to find out when a coating loss or repelling occurs in the step of providing the adhesive layer. Such coating loss and repellency cause adhesion failure in the bonding process with the sealing material, resulting in a significant decrease in power generation efficiency when the solar cell module is used over a long period of time. It was.

JP 2006-152013 A JP 2006-320991 A JP 2007-136911 A

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an easy-adhesive film that allows easy understanding of defects in the step of providing an adhesive layer and that has both good coat appearance and adhesiveness over time.

As a result of intensive studies to solve the above-mentioned problems, the inventor is an easy-adhesion film having a coating layer on at least one surface of a translucent polyester film, and the polyester film substrate is a polyethylene terephthalate film substrate. Yes, the coating layer is formed by coating and drying a coating solution containing a pigment and a surfactant, and the water contact angle of the coating layer is 80 ° or more and 100 ° or less, and the OD value after forming the coating layer is 1. By adjusting to 0.0 or more and 4.0 or less, it is possible to easily grasp the defects of the coating layer that can be a cause of deterioration of the solar cell module in the process, and at the same time, achieve both adhesion between the coat appearance and the sealing material, It has been found that an easy-adhesive film that can suppress deterioration of adhesion with a sealing material due to bleed-out of a surfactant even after long-term storage can be provided, leading to the present invention. Is.

That is, this invention consists of the following structures.
1. An easy-adhesion film having a coating layer on at least one side of a translucent polyester film substrate, wherein the polyester film substrate is a polyethylene terephthalate film substrate, and the coating layer contains a dye and a surfactant, And the water contact angle of the said application layer is 80 degrees or more and 100 degrees or less, OD value is 1.0 or more and 4.0 or less, The easily adhesive film characterized by the above-mentioned.
2. The easily adhesive film as described in the above item 1, wherein the surfactant is a silicone-based surfactant.
3. The easy-adhesive film according to the first or second aspect, wherein the surfactant is a silicone-based surfactant containing a hydroxyl group.
4). The easily adhesive film according to any one of the first to third aspects, wherein the coating layer contains a polyester resin or a polyester polyurethane resin and a crosslinking agent.
5. A method for producing an easy-adhesion film having a coating layer on at least one surface of a translucent polyester film substrate, wherein the polyester film substrate is a polyethylene terephthalate film substrate, and a water contact angle of the coating layer is 80 ° or more and 100 A method for producing an easy-adhesive film, which has an OD value of 1.0 or more and 4.0 or less, and includes the following two steps when forming a coating layer.
(1) A step of applying a coating liquid containing at least a pigment and a surfactant (2) A step of drying after applying the coating liquid to the drying oven for 1 second to 10 seconds

  The easy-adhesive film of the present invention makes it easy to identify defects in the process of providing an adhesive layer, and achieves both good coat appearance and adhesion with a sealing material over time. As a preferred embodiment of the present invention, when the easy-adhesive film of the present invention is used as a solar battery back sheet member, the adhesion surface between the back sheet and the sealing material has poor adhesion due to coat defects or poor wetting of the sealant. It can prevent, and it can contribute to the lifetime improvement of a solar cell module by maintaining adhesiveness with a sealing material over a long period of time. In addition, even when the easy-adhesive film is stored for a long period of time, the adhesiveness with the sealing material is good, so that a stable solar cell module can be produced regardless of the storage period of the backsheet.

(Polyester film substrate)
The polyester resin constituting the substrate in the present invention includes polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polymethylene terephthalate, and copolymerization components such as diethylene glycol, neopentyl glycol, polyalkylene glycol, etc. A diol component, a polyester resin copolymerized with a dicarboxylic acid component such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or the like can be used.

  The polyester resin suitably used in the present invention mainly contains at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as a constituent component. Among these polyester resins, polyethylene terephthalate is most preferable from the balance between physical properties and cost. Moreover, these polyester films can improve chemical resistance, heat resistance, mechanical strength, etc. by biaxially stretching.

  These polyester films are also resistant to hydrolysis, such as keeping the carboxyl end concentration low to prevent hydrolysis by acid, or using polyester with a relatively high molecular weight so as not to greatly deteriorate the mechanical properties even if the deterioration has progressed to some extent. A thing with high property can be used. By using a polyester film having improved hydrolysis resistance as a base material, it is possible to further improve the adhesion to the sealing material over a long period of time.

  Further, the polyester film substrate in the present invention may be a single layer polyester film or a polyester film having at least three layers having an outermost layer and a center layer.

  These layers may contain various additives in the polyester as necessary. Examples of the additive include particles, an antioxidant, a light resistance agent, an antigelling agent, an organic wetting agent, an antistatic agent, an ultraviolet absorber, and a surfactant.

  The type of particles contained in the outermost layer may be inorganic particles or organic particles, and is not particularly limited, but is not limited to metal oxides such as silica, titanium dioxide, talc, and kaolinite, and carbonic acid. Examples thereof include inorganic particles inert to polyester such as calcium, calcium phosphate, and barium sulfate. Any one of these inert inorganic particles may be used alone, or two or more thereof may be used in combination.

  The particles preferably have an average particle size of 0.1 to 3.5 μm. The lower limit of the average particle diameter is more preferably 0.5 μm, further preferably 0.8 μm, and particularly preferably 1.0 μm. Further, the upper limit of the average particle is more preferably 3.0 μm, still more preferably 2.8 μm. If the average particle size is less than 0.1 μm, it is difficult to obtain sufficient handling properties, which is not preferable. If it exceeds 3.5 μm, coarse protrusions are likely to be generated, which is not preferable.

  These particles are preferably porous particles, particularly porous silica. The porous particles are preferable because they are easily deformed into a flat shape when stretched in the film forming process and the decrease in transparency is small.

  The content of inorganic particles in the outermost layer is preferably 0.01 to 0.20 mass% with respect to the polyester constituting the outermost layer. The lower limit of the concentration is more preferably 0.02% by mass, and further preferably 0.03% by mass. Further, the upper limit of the concentration is more preferably 0.15% by mass, and further preferably 0.10% by mass. If it is less than 0.01% by mass, it is difficult to obtain sufficient handling properties, which is not preferable. If it exceeds 0.2% by mass, the transparency is lowered, which is not preferable.

The average particle diameter of the particles can be measured by the following method.
The particles are photographed with an electron microscope or an optical microscope, and the maximum diameter of 300-500 particles (in the case of porous silica, the aggregate size) is such that the size of one smallest particle is 2-5 mm. Particle diameter) is measured, and the average value is taken as the average particle diameter. Moreover, when calculating | requiring the average particle diameter of the particle | grains in the coating layer of a laminated film, the cross section of a laminated film is image | photographed by 120,000 times magnification using a transmission electron microscope (TEM), and the largest diameter of a particle | grain is calculated | required. Can do.

  A known method can be adopted as a method of blending the above-mentioned particles with polyester. For example, it can be added at any stage for producing the polyester, but it is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or after the end of the ester exchange reaction and before the start of the polycondensation reaction. The polycondensation reaction may proceed. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a method of blending dried particles and a polyester raw material using a kneading extruder It can be carried out.

  The thickness of the polyester film base material used as the base material of the present invention is 20 to 500 μm, more preferably 25 to 450 μm, and still more preferably 30 to 300 μm. When the substrate thickness is less than 20 μm, the influence of heat shrinkage is large, and the adhesiveness after high-temperature and high-humidity treatment may be lowered, which is not preferable. When the thickness exceeds 500 μm, winding as a roll becomes difficult, which is not preferable.

  The polyester film substrate in the present invention is preferably translucent. In the present invention, translucency means that the total light transmittance is 80% or more. When the total light transmittance is low and the film itself is colored black or white, it is not preferable because it is difficult to detect minute coating loss or repellency in the manufacturing process of the coating layer. For solar cell applications that require long-term adhesion, these small defects affect the long-term stability of the product, so a polyester film substrate that can be visually inspected by transmitted light during the manufacturing process. It is desirable to use

(Coating layer)
In the present invention, the easy-adhesion film has a coating layer containing at least a pigment and a surfactant.

  The pigment | dye in this invention is disperse | distributing uniformly in resin mentioned later, and it is calculated | required to express concealability. Therefore, it is desirable that the coloring matter in the present invention is one or more dyes or pigments that are easily dispersed in the resin and solvent described below.

  A pigment | dye is not specifically limited, A well-known thing can be used. Examples of pigments include metal oxides such as titanium oxides, iron oxides, and complex oxides; other chromates, sulfides, silicates, carbonates, ferrocyanides, carbon black Inorganic pigments other than metal oxides such as: azo compounds such as soluble azo and insoluble azo (monoazo, disazo); condensed azo metal complexes azo, benzimidazolone, polycyclic phthalocyanine, anthraquinone And organic pigments comprising indigo, perinone, perylene, quinacridone, isoindolinone, metal complex, methine / azomethine, and diketopyrrolopyrrole.

  As dyes, naphthol dyes, azo dyes, metal complex dyes, azine dyes (nigrosine dyes), cyanine dyes, quinoline dyes, nitro dyes, anthraquinone dyes, quinoimine dyes, indigo dyes, nitroso dyes, benzoquinone dyes, carbonium dyes, naphthoquinone dyes, Naphthalimide dyes, phthalocyanine dyes and the like can be mentioned.

  The amount of the pigment in the coating layer is preferably 10% by mass or more and 100% by mass or less with respect to the resin described later. When the amount of the pigment in the resin is small, it is necessary to increase the coating amount of the coating layer in order to achieve the desired concealing property. If sufficient drying is desired, the temperature is increased and / or prolonged. It is necessary, and the flatness of the base material is likely to occur. On the other hand, when the amount of the dye in the resin is large, the strength of the coating film is reduced due to the excessive dye, or the dye that could not be contained in the resin remains on the surface and the appearance is impaired.

  In the present invention, the coating layer is formed by coating and drying a coating liquid containing a pigment, a resin, and an organic solvent on a transparent substrate. At this time, it is particularly preferable to include a surfactant in the coating solution. By including the surfactant, the coating appearance of the coating layer, in particular, dents due to minute bubbles, adhesion of foreign matters, etc., and repelling in the drying process are improved.

  As the surfactant, known cationic, anionic, and nonionic surfactants can be suitably used. However, a silicone surfactant having excellent surface activity is used, and as a result, a coating film having a high water contact angle value is obtained. It is preferable to improve the coating appearance of the coating layer.

  On the other hand, the sealing agent partially melted during the process when the sealing agent is brought into close contact with the coating layer having such a high water contact angle value cannot be sufficiently wet spread in the coating layer. As a result, since a good adhesion interface cannot be obtained, there has been a problem that the adhesive force is remarkably lowered.

  Accordingly, the inventors have conducted intensive studies, and when adding a surfactant, the water contact angle of the finally formed coating layer is 80 ° to 100 °, more preferably 85 ° to 97.5 °. Furthermore, it was found that the coating appearance of the coating layer and the adhesiveness of the sealant can be compatible by controlling the angle between 90 ° and 95 ° more preferably. A water contact angle of less than 80 ° is not preferable because defects such as omission, repellency, and cocoon skin occur in the coat layer. In addition, a water contact angle of 100 ° or more is not preferable because it adversely affects the adhesion with the sealing material.

  Further, it is generally known that surfactants do not stay in the coating layer because of their low molecular weight, but precipitate on the coating layer surface over time. Therefore, the water contact angle on the surface of the coating layer increases with time due to the deposited surfactant, which may adversely affect the adhesion with the sealant.

  Therefore, the inventors have further studied and found that among silicone surfactants, it is particularly preferable to use a modified silicone surfactant having a hydroxyl group in the molecule. By using the surfactant, it is possible to achieve both excellent coating appearance and adhesion between the sealing material after being left for a long time. Although this mechanism is not clear, it is presumed that the hydroxyl group in the surfactant is hydrogen bonded to the dye in the coating layer and the surfactant is prevented from bleeding out to the coating layer surface over time.

As a silicone-based surfactant,
TSF4440, TSF4441, TSF4445, TSF4446, TSF4452, TSF4460 (more from Momentive Performance Materials), KP-321, KP-323, KP-324, KP-326, KP-340, KP-341 (more than Shinetsu Chemical Industries) L-7001, L-7002, 8032 ADDITIVE, 57 ADDITIVE, L-7604, FZ-2110, FZ-2105, 67 ADDITIVE, 8616 ADDITIVE, 3 ADDITIVE, 56 ADDITIVE (above Toray Dow Corning) Dispalon (registered trademark) 1711, Disparon 1751N, Disparon 1761, Disparon LHP-91, Disparon LHP-96 (manufactured by Enomoto Kasei Co., Ltd.), BYK (registered trademark) -300, B K-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK- 331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-371, BYK-378, BYK-3455 (manufactured by Big Chemie) ),
Examples of the modified silicone surfactant having a hydroxyl group include XF42-B0970 (manufactured by Momentive Performance Materials), SF-8428 (manufactured by Toray Dow Corning), BYK-370, BYK- 375, BYK-377 (above made by Big Chemie)
Etc., and these can be used alone or in admixture of two or more.

  When using a modified silicone-based surfactant having a hydroxyl group, if the coating layer weight after drying is 0.1% by mass or more, excellent coating appearance and adhesion between the sealing material after standing for a long time It becomes possible to obtain the effect. More preferably, it is 0.2 mass% or more. Also, the water contact angle can be adjusted to a desired range. However, if the content is too large, the water contact angle may become too large, so it may be 4% by mass or less. More preferably, it is 2 mass% or less.

  Known resins can be used as the resin in the present invention. Of these, a polyester-based resin having excellent adhesion to a polyester film substrate or a polyester polyurethane resin is preferable.

  In addition, it is desirable to incorporate a crosslinked structure in order to improve the weather resistance of the coating layer. At this time, the cross-linked structure may be provided with a functional group having cross-linkability in a part of the resin itself, or a cross-linking agent containing a functional group having cross-linkability may be added separately from the resin. As a functional group which becomes the origin of a crosslinked structure, well-known things, such as an isocyanate group, an epoxy group, an oxazoline group, a carbodiimide group, are mentioned, for example.

  The content when the crosslinking agent is added depends on the kind of the crosslinking agent, but the mass ratio of the solid content of the crosslinking agent to the solid content mass of the resin constituting the coating layer is 20 mass% or more and 200 mass% or less. Preferably, 50 mass% or more and 170 mass% or less are still more preferable.

  The transmission OD value of the coating layer is preferably 1.0 or more and 4.0 or less, more preferably 2.0 or more and 3.0 or less. When the transmission OD value is less than 1.0, it is difficult to obtain concealability when used as a solar cell backsheet member, and the power generation efficiency and design of the solar cell module are inferior. Further, when the transmission OD value exceeds 4.0, it is not only disadvantageous in terms of cost because a large amount of dye is used, but it is necessary to add a large amount of surfactant in order to obtain a good dispersion state. This is not preferable because it may cause bleeding out.

  The coating layer in the present invention may contain various particles for the purpose of forming irregularities on the surface and improving the slipperiness and handling properties. Examples of particles to be included in the coating layer include inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, and alumina, and organic materials such as acrylic, PMMA, nylon, styrene, polyester, and benzoguanamine / formalin condensate. Particles.

  In this invention, it is preferable that a coating layer is laminated | stacked by apply | coating and drying the coating liquid containing resin, a pigment | dye, and surfactant on a transparent base material. The coating solution needs to be diluted with an organic solvent in view of coating properties.

  Examples of the organic solvent include (1) alcohols such as methyl alcohol, ethyl alcohol, N-propyl alcohol, isopropyl alcohol, N-butyl alcohol, tridecyl alcohol, cyclohexyl alcohol, 2-methylcyclohexyl alcohol, and (2) ethylene glycol. , Glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, glycerin, (3) ethylene glycol monomethyl ether, ethylene glycol monoethylene ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , Diethylene glycol butyl ether, ethylene glycol monomethyl ether Glycol ethers such as teracetate, ethylene glycol monoethyl acetate, ethylene glycol monobutyl acetate, diethylene glycol monomethyl acetate, diethylene glycol monoethyl acetate, diethylene glycol monobutyl acetate, (4) ethyl acetate, isopropylene acetate, N-butyl acetate, etc. Examples include esters, (5) ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, isophorone, diacetone alcohol, etc. These may be used alone or in combination of two or more. Can do.

  Preferably, ketones excellent in dye solubility are contained in an amount of 30% by mass to 80% by mass with respect to the total organic solvent used in the coating solution. Other organic solvents are preferably selected in consideration of leveling properties and drying properties. The boiling point of the organic solvent is preferably 60 ° C. or higher and 180 ° C. or lower. When the boiling point is as low as less than 60 ° C., the solid content concentration of the coating solution changes during coating, and the coating thickness is difficult to stabilize, which is not preferable. On the other hand, when the boiling point is higher than 180 ° C., the amount of the organic solvent remaining in the coating film is increased, which is not preferable in terms of stability over time.

  If contamination or undissolved material of 1 μm or more is present in the coating liquid, the appearance after application tends to be poor. Therefore, it is preferably removed with a filter or the like before application. Various filters can be suitably used as the filter, but it is preferable to use a filter capable of removing 99% or more of a 1 μm size filter. When a coating liquid containing 1 μm or more of contamination or undissolved material is applied and dried, a dent or the like is generated around the coating liquid, which may be a disadvantage of a size of 100 to 1000 μm.

  As for solid content concentration, such as resin and a pigment | dye contained in a coating liquid, 10 to 50 mass% is preferable. When the solid content concentration is less than 10% by mass, it takes time to dry after coating, and productivity is inferior, and the amount of solvent remaining in the coating film increases, which is not preferable in terms of stability over time. . On the contrary, when the solid content concentration is higher than 50% by mass, the viscosity of the coating liquid is increased, the leveling property is insufficient, and the coating appearance is liable to be unfavorable. The viscosity of the coating solution is preferably 10 CPS or more and 300 CPS or less in terms of coating appearance, and it is preferable to adjust the solid content concentration, the organic solvent, etc. so as to be in this range.

  In the present invention, as a method of applying and laminating a coating layer on a transparent substrate by a coating method, gravure coating method, kiss coating method, dip method, spray coating method, curtain coating method, air knife coating method, blade coating method, reverse Conventionally used methods such as a roll coating method, a bar coating method, and a lip coating method can be applied. Among these, a gravure coating method that can be applied uniformly, particularly a reverse gravure method is preferable. The diameter of the gravure is preferably 80 mm or less. If the diameter is larger than 80 mm, the frequency of undulation streaks increases in the flow direction, which is not preferable.

The coating amount after drying of the coating layer is not particularly limited, but the lower limit is preferably 1 g / m ² , more preferably 2 g / m ² , and the upper limit is preferably 20 g / m ² , more preferably 10 g / m ² . is there. When the coating amount after drying is small, the concealability of the coating layer tends to be insufficient. For this reason, increasing the amount of the pigment in the resin causes deterioration of the coating strength and precipitation of the pigment. Conversely, when the coating amount after drying is large, the concealability of the coating layer is sufficient, but drying tends to be insufficient. On the other hand, when the drying is sufficient, the flatness of the substrate becomes poor.

  Examples of the method for drying the coating liquid applied on the transparent substrate include known hot air drying, use of an infrared heater, and the like. Hot air drying with a high drying speed is preferable. In the initial constant rate drying stage after coating, drying is preferably performed at 20 ° C. or more and 80 ° C. or less using hot air of 2 m / sec or more and 30 m / sec. When initial drying is performed strongly (the hot air temperature is higher than 80 ° C. and / or the hot air flow rate is higher than 30 m / second), the surfactant is not easily localized on the surface and is durable. Not only is the effect of improving the property and imparting slipperiness difficult, but minute defects of the coating film such as fine coat removal, fine repellency, cracks, and the like are liable to occur. Conversely, when initial drying is weakened (the hot air temperature is lower than 20 ° C. and / or the hot air flow rate is smaller than 2 m / second), the appearance is improved, but the drying time is increased and the cost is reduced. Not only is there a problem, but problems such as brushing are likely to occur, which is not preferable.

  In the reduction drying process, it is necessary to increase the temperature higher than the initial drying to reduce the solvent in the coating film, and the preferable temperature is 120 ° C. or higher and 180 ° C. or lower. Particularly preferably, the lower limit is 140 ° C and the upper limit is 170 ° C. When the temperature is lower than 120 ° C., it is difficult to reduce the solvent in the coating film, which becomes a residual solvent and the stability of the coating film over time is likely to be insufficient, which is not preferable. On the other hand, when the temperature is higher than 180 ° C., the flatness of the substrate tends to be poor due to heat wrinkles, which is not preferable. The passing time is preferably 5 seconds or more and 180 seconds or less. If the time is shorter than 5 seconds, the solvent remaining in the coating film increases, which is not preferable in terms of stability over time. Conversely, if the time is longer than 180 seconds, the productivity is reduced. And heat wrinkles are easily generated on the substrate, which is not preferable. The upper limit of the passage time is particularly preferably 30 seconds from the viewpoint of productivity and flatness.

  The time from application of the coating liquid to entering the drying furnace is preferably from 1 second to 10 seconds. If the time to enter the drying furnace is less than 1 second, the surfactant is dried in a dispersed state in the coating layer, so the coating appearance improvement effect by the surfactant cannot be obtained, and the appearance point It is not preferable. Further, if the surfactant is dried without completely depositing on the surface, the water contact angle may be reduced, which is not preferable. On the other hand, if it exceeds 10 seconds, the surfactant is significantly bleed out on the surface of the coating layer, and the adhesiveness to the sealing material tends to be lowered, which is not preferable.

  In the final stage of drying, it is preferable to set the hot air temperature to be equal to or lower than the glass transition temperature of the resin, and in the flat state, the actual temperature of the substrate is equal to or lower than the glass transition temperature of the resin. When leaving the drying oven at a high temperature exceeding the glass transition temperature, the coated surface is difficult to slip when it comes into contact with the roll surface, and not only scratches are likely to occur, but also curls may occur. There is not preferable.

(Easily adhesive film)
In this invention, it is preferable that the transmission OD value of an easily bonding film is 1.0 or more and 4.0 or less, More preferably, it is 2.0 or more and 3.0 or less. The OD value can be adjusted by the pigment density in the coating layer of the easy-adhesion film and the thickness of the coating layer.

  In this invention, it is preferable that the water contact angle of the surface of an easily bonding film is 80 degrees or more and 100 degrees or less. As a method of adjusting, it is possible to change the kind and addition amount of the surfactant used in the coating layer, or to adjust the drying conditions when forming the coating layer.

  Further, it is desirable that the easy-adhesive film does not have a defect having a diameter of 300 μm or more, more preferably 100 μm or more. If there is a defect of the above size, adhesion failure occurs when closely contacting with the sealing material, and the sealing material and the easy-adhesive film are peeled off over time, and moisture and the like enter through the gap, and the power generation efficiency of the solar cell module It is not preferable because it causes a significant decrease in.

  The easy-adhesion film in the present invention is a film having high adhesion to a sealing material used for a solar cell module. Examples of the sealing material include resin sheets using ethylene-vinyl acetate copolymer (EVA) and polyvinyl butyral (PVB). In particular, EVA sheets are often used for solar cell applications, and easy adhesion with EVA sheets is also required as an easy adhesion film.

  The adhesion strength with the EVA sheet is preferably as high as possible, specifically 50 N / 20 mm or more, more preferably 75 N / 20 mm or more, and even more preferably 100 N / 20 mm or more. When the adhesion is less than 50 N / 20 mm, when used as a member of a solar cell backsheet, peeling occurs with the EVA sheet, and moisture or the like enters through the gap to improve the power generation efficiency of the solar cell module. This is not preferable because it causes a significant decrease. In addition, although it does not set in particular about an upper limit, about 150 N / 20mm is an actual measurement limit by cohesive failure of a base film and an EVA sheet.

  In addition, it is desirable that the easy-adhesive film maintain the adhesion with the EVA sheet even after long-term storage. It is preferable that the adhesive strength with the EVA sheet after long-term storage is higher, specifically 50 N / 20 mm or more, more preferably 75 N / 20 mm or more, and further preferably 100 N / 20 mm or more. When the adhesion with the EVA sheet after long-term storage is less than 50 N / 20 mm, the adhesion of the easy-adhesion film may be hindered during the manufacturing process of the solar cell back sheet, and as a result, the solar cell back When it is used as a sheet member, it peels off from the EVA sheet, and moisture or the like enters from the gap to cause a significant decrease in the power generation efficiency of the solar cell module. In addition, although it does not set in particular about an upper limit, about 150 N / 20mm is an actual measurement limit by cohesive failure of a base film and an EVA sheet.

  In addition, long-term storage in the present invention means that the easy-adhesive film is stored in a roll form before the next process is performed. In the present invention, in order to reproduce this state, it was used as a guide for long-term storage by promoting evaluation with a constant temperature and humidity chamber at 85 ° C. and 85%. Under these conditions, it is widely known that storage for 1000 hours is equivalent to outdoor storage for about 10 years, and the easy-adhesive film of the present invention is more than 100 hours at 85 ° C. and 85%, more preferably It is preferable that the adhesiveness with the sealant is maintained even after being left in a sheet form for 400 hours or more.

  In addition, since the easy-adhesive film is used outdoors as a back sheet member for a long period of 10 years or longer, it is desirable to maintain the adhesiveness after being in close contact with the EVA sheet. In general, as in the case of adhesion after long-term storage, storage in a constant temperature and humidity chamber at 85 ° C. and 85% is regarded as accelerated evaluation, and it is preferable that the adhesion is maintained even after being left for 1000 hours under these conditions. Specifically, it is desirable to be 50 N / 20 mm or more, more preferably 75 N / 20 mm or more, and still more preferably 100 N / 20 mm or more. When the adhesive strength is less than 50 N / 20 mm after standing at 85 ° C. and 85% for 1000 hours, the EVA sheet and the easy-adhesive film peel off over time, and moisture and the like enter through the gap to generate power generation efficiency of the solar cell module It is not preferable because it causes a significant decrease in the temperature. In addition, although it does not set in particular about an upper limit, about 150 N / 20mm is an actual measurement limit by cohesive failure of a base film and an EVA sheet.

(Back sheet)
The solar cell backsheet of the present invention comprises an easily adhesive film as a constituent member. In particular, it is preferably used for the outermost layer that is in direct contact with the sealing material. With such a configuration, the solar cell backsheet of the present invention can exhibit strong adhesion to the encapsulant, and can exhibit good adhesion even under harsh environments over a long period of time. Therefore, it can contribute to moisture proof maintenance and barrier property improvement of the solar cell element.

  As an aspect of the solar cell backsheet of the present invention, for example, there is a configuration such as an easily adhesive film / adhesive / metal foil or a film having a metal-based thin film layer / adhesive / polyvinyl fluoride film or a polyester-based highly durable moisture-proof film. Illustrated. Here, as the film having a metal foil or a metal thin film layer, a film having a water vapor barrier property can be suitably used.

  Examples of the metal include aluminum, tin, magnesium, silver, and stainless steel. Among them, aluminum and silver are preferable because they have a relatively high reflectance and are easily available industrially. The metal layer may be used as a metal foil, or may be laminated as a thin film on a polyester film or the like. As a method of laminating these metals as a thin film, a vacuum deposition method, a sputtering method, an ion plating method, a plasma vapor deposition method (CVD), or the like can be used.

  In the present invention, an easy adhesion film, a film having a metal foil or a metal-based thin film layer, a lamination method in which each layer of a polyvinyl fluoride film or a polyester-based high durability moisture-proof film is integrally heat-pressed by vacuum suction or the like. The back sheet for solar cells can be manufactured by using the conventional molding method and thermocompression-molding each of the above layers as an integrally molded body. In the above, in order to improve the adhesiveness etc. between each film, it is preferable to laminate | stack via an adhesive agent. Examples of the adhesive include (meth) acrylic resins, olefinic resins, vinyl resins, and other heat melting adhesives, solvent-based adhesives, photo-curing adhesives, etc. whose main component is a vehicle. It is done.

  Here, the high durability moisture-proof film is laminated for the purpose of improving the weather resistance, and examples of the high durability moisture-proof film include polytetrafluoroethylene (PTFE), 4-tetrafluoroethylene-perchloroalkoxy copolymer. Polymer (PFA), 4-tetrafluoroethylene-6-propylene-propylene copolymer (FEP), 2-ethylene-tetrafluoroethylene copolymer (ETFE), poly-3-tetrafluoroethylene (PCTFE), polyfluoride Fluorine resin film such as vinylidene (PVDF) or polyfuca vinyl (PVF), or UV absorber for resin such as polycarbonate, polymethyl methacrylate, polyacrylate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic Examples thereof include a film made of a kneaded resin composition.

  Next, examples and comparative examples of the present invention will be shown. The characteristic value measurement method and effect evaluation method used in the present invention are as follows.

(1) OD value Using a black and white transmission densitometer (Ihara Electronics Industrial IHAC-T5), measurement was performed so that light was applied to the coated surface side.

(2) Appearance of coated surface The coated surface of the obtained EVA easy-adhesive film is placed on an electric decoration BOX (manufactured by KOKUYO) and visually observed by an observer with a visual acuity of 1.0 to 1.5 from a place 1 m away. It was confirmed that there was no abnormality in the coating appearance. The ranking was based on the following criteria.
○: The number of cissings that can be visually confirmed is 1 or less / A4 size, and no coating spots are observed. Δ: The number of cissing that can be visually confirmed is 1 or less / A4 sizes, and the coating spots are visible. 1 or more repellants can be confirmed

(3) Sealing material adhesion The prepared easy-adhesive film was cut into 100 mm width × 100 mm length and the sealing material was cut into 70 mm width × 90 mm length, and the film (coating surface) / EVA / (coating described below) was prepared. Construction surface) A sample was prepared by stacking with a film structure and heat-pressing with a vacuum laminator under the bonding conditions described below. The prepared sample was cut out into a width of 20 mm and a length of 100 mm, attached to a SUS plate, and the peel strength between the film layer and the EVA layer was measured with a tensile tester under the conditions described below. The peel strength was determined as the average value of the portions that peeled stably after exceeding the maximum point. In addition, when it fractured | ruptured at the maximum point, the numerical value of the maximum point was made into the breaking strength.

(Sample creation conditions)
Apparatus: Vacuum laminator NP-30 type LM-30x30 pressurization: 1 atmosphere EVA:
Sanvic standard cure type ULTLA PEARL PV (0.4μm)
Lamination process: 100 ° C. (vacuum 5 minutes, vacuum pressurization 5 minutes)
Cure process: Heat treatment 150 ° C (normal pressure 45 minutes)

(Measurement condition)
Apparatus: Tensilon RTM-100 manufactured by Toyo BALDWIN
Peeling speed: 200 mm / min Peeling angle: 180 degrees

(4) Adhesiveness with sealing material after long-term storage The obtained easy-adhesion film was left in an environment of 85 ° C. and 85% RH for 100 hours in a high-temperature and high-humidity tank. Next, the easy-adhesion film was taken out and left at room temperature and normal humidity for 24 hours. Thereafter, the peel strength was measured by the same method as in (3) above.

(5) Adhesiveness with sealing material after durability evaluation The laminate of the easy-adhesive film (applied layer surface) / EVA / (applied layer surface) easy-adhesive film obtained in (3) is 85 ° C in a high-temperature and high-humidity tank , And left in an environment of 85% RH for 1000 hours. The sample was taken out from the high-temperature and high-humidity tank and allowed to stand in an environment of 25 ° C. and 65% RH for 200 hours, and then the peel strength was measured by the same method as in (3) above.

(6) Water contact angle The water contact angle was measured according to the JIS-R3257 sessile drop method using Kyowa Interface Chemical Co., Ltd. contact angle meter CA-X type. Specifically, in an environment of a temperature of 23 ° C. and a humidity of 50% RH, a sample piece of the obtained easy-adhesive film was placed horizontally with the coating layer surface facing up, and each N = 5 measurements were performed with water or methylene iodide. The average value of the contact angles was taken as the contact angle of each solvent. In addition, when calculating | requiring the contact angle of water, the dripping amount was 1.8 microliters and the contact angle after standing still for 1 minute was read.

(7) Total light transmittance of base film About the polyester film used as a base material, the total light transmittance was measured according to JIS-K7136 using the haze meter (The Tokyo Denshoku Industries make, model TC-H3DP). .

Example 1
The following coating liquid A was applied to polyester film E5100-50 (manufactured by Toyobo Co., Ltd.) on the corona-treated surface of the base film using a reverse gravure with a diameter of 60 cm. Secondly, 20 seconds with hot air of 5 m / second at 40 ° C., 20 seconds with hot air of 20 m / second at 150 ° C., and 10 seconds with hot air of 20 m / second at 90 ° C. did. The OD value after drying was 2.5.

(Coating liquid A for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare coating solution A.
・ Toluene 26.85% by mass
・ Methyl ethyl ketone 26.8% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate (registered trademark) L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST (registered trademark) BLACK 3810 manufactured by Orient Chemical Co., Ltd.)
・ Silicone surfactant 0.05% by mass
(Toray Dow Corning 57ADDITIVE solid content concentration: 100% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although the adhesiveness after storage for a long period of time was slightly inferior, an easy-adhesive film having an adhesiveness with a level of a sealing material having no practical problem could be obtained.

(Example 2)
The following coating liquid B was applied and dried under the same conditions as in Example 1 to obtain an easy-adhesion film.

(Coating fluid B for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare coating solution B.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.7% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

Example 3
The following coating liquid C was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid C for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution C.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.8% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicon surfactant 0.1% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

Example 4
The following coating liquid D was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid D for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution D.
・ Toluene 26.4% by mass
・ Methyl ethyl ketone 26.3 mass%
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 1.0% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 5)
The following coating liquid E was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating fluid E for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Next, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution E.
・ Toluene 28.8% by mass
・ Methyl ethyl ketone 28.7% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 3.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 6)
The following coating liquid F was applied and dried under the same conditions as in Example 1 to obtain an easy-adhesion film.

(Coating fluid F for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution F.
・ Toluene 25.3% by mass
・ Methyl ethyl ketone 25.2% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 10.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 7)
The following coating solution was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid G for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Next, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution G.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.7% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-375 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 8)
The following coating solution was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating fluid H for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution H.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.7% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-377 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

Example 9
The following coating solution was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid I for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating liquid I.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.7% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Nigrosine black dye 7.0% by mass
(NUBIAN (registered trademark) BLACK NH-805 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 10)
The following coating liquid J was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid J for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution J.
・ Toluene 24.4% by mass
・ Methyl ethyl ketone 24.3% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Acetylene-based surfactant 5.0% by mass
(Shinfin Chemical Surfynol 420 solid concentration: 100% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although some coating spots and repellencies were seen in the coating film, the adhesion after durability evaluation was slightly lowered, but an easy-adhesive film having a level of practically no problem could be obtained.

(Example 11)
The following coating liquid K was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid K for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to adjust the coating solution K.
・ Toluene 15.1% by mass
・ Methyl ethyl ketone 15.0 mass%
・ Polyester polyurethane resin 62.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although the adhesiveness after durability evaluation was inferior, the easily adhesive film which has adhesiveness with the sealing material of a level which is satisfactory practically was able to be obtained.

(Example 12)
It takes 2 seconds to enter the drying oven, 60 seconds with hot air of 5 m / second at 40 ° C., 60 seconds with hot air of 20 m / second at 150 ° C., and 30 seconds with hot air of 20 m / second at 90 ° C. An easily adhesive film was obtained in the same manner as in Example 2 except that the film was dried.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although some coating spots and repellencies were seen in the coating film, the adhesion after durability evaluation was slightly lowered, but an easy-adhesive film having a level of practically no problem could be obtained.

(Example 13)
It takes 8 seconds to enter the drying oven, 60 seconds with hot air of 5 m / second at 40 ° C., 60 seconds with hot air of 20 m / second at 150 ° C., and 30 seconds with hot air of 20 m / second at 90 ° C. An easily adhesive film was obtained in the same manner as in Example 2 except that the film was dried.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Since the surfactant is deposited on the surface of the coating film in a large amount, the water contact angle is increased, and therefore, the adhesion of the sealing material is reduced as a whole. I was able to get it.

(Example 14)
The following coating liquid L was applied and dried under the same conditions as in Example 1 to obtain an easy-adhesion film.

(Coating liquid L for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Next, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare the coating liquid L.
・ Toluene 24.5% by mass
・ Methyl ethyl ketone 24.5% by mass
・ Polyester polyurethane resin 31.3% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 12.5% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although the adhesiveness after durability evaluation was slightly inferior, an easy-adhesive film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Example 15)
The following coating liquid M was applied and dried under the same conditions as in Example 1 to obtain an easy-adhesion film.

(Coating liquid M for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution M.
・ Toluene 28.5% by mass
・ Methyl ethyl ketone 28.5% by mass
-Polyester polyurethane resin 18.2% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 17.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Although the sealing material adhesion was slightly inferior, it was possible to obtain an easy-adhesive film that achieved both excellent coating appearance and adhesion over time with the sealing material.

(Example 16)
A weather-resistant polyester film Q1210-50 μm (manufactured by Toyobo) was used in the same manner as in Example 2 to obtain an easy-adhesive film.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Since a weather-resistant polyester film was used, the film was not broken even after 1000 hours of durability evaluation, and an easy-adhesion film having excellent adhesion could be obtained.

(Example 17)
The following coating liquid N was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid N for coating layer)
A polyester resin (Toyobo's Byron 280) was dissolved in toluene to a solid content concentration of 30% by mass and stirred for 30 minutes or more to obtain a polyester resin dissolved product. Next, the materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating liquid N.
・ Toluene 26.8% by mass
・ Methyl ethyl ketone 26.7% by mass
・ Polyester resin melt 23.7% by mass
(Toyobo, Byron 280, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

(Example 18)
The following coating liquid O was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating solution O for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution O.
・ Toluene 23.4% by mass
・ Methyl ethyl ketone 23.3% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Carbodiimide type crosslinking agent 22.4% by mass
(Nisshinbo Chemical Co., Ltd., Carbodilite V-07, solid content: 50% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. An easy-adhesion film having both excellent coat appearance and adhesiveness with the sealing material over time could be obtained.

(Comparative Example 1)
Black polyester film An easy-adhesion film was obtained in the same manner as in Example 2 except that Lumirror (registered trademark) X30-50 μm (manufactured by Toray) was used.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. The appearance of the coated surface could not be confirmed, and the coating appearance abnormality that had been mixed in could not be confirmed. For this reason, an adhesion failure that appears to have occurred due to an abnormal appearance of the coat occurred, and the adhesion of the sealing material after durability evaluation was significantly reduced.

(Comparative Example 2)
The following coating liquid P was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid P for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Next, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution P.
・ Toluene 29.9% by mass
・ Methyl ethyl ketone 29.9% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 0.7% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. The OD value was greatly reduced, and no concealability was obtained. Moreover, the adhesiveness with a sealing agent also fell remarkably.

(Comparative Example 3)
The following coating liquid Q was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating liquid Q for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution Q.
・ Toluene 23.3% by mass
・ Methyl ethyl ketone 23.2% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 14.0 mass%
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.2% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. The dye that could not be dispersed in the resin was deposited on the surface of the coating film, and the appearance and the adhesiveness of the sealing material were significantly reduced.

(Comparative Example 4)
The following coating liquid R was applied and dried under the same conditions as in Example 1 to obtain an easy-adhesion film.

(Coating liquid R for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution R.
・ Toluene 26.89% by mass
・ Methyl ethyl ketone 26.8% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 0.01% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Since the addition amount of the surfactant was insufficient, the appearance was remarkably deteriorated. In addition, adhesion failure that was thought to have occurred due to abnormal appearance of the coat occurred, and the adhesion of the sealing material after durability evaluation was significantly reduced.

(Comparative Example 5)
The following coating liquid S was applied and dried under the same conditions as in Example 1 to obtain an easily adhesive film.

(Coating fluid S for coating layer)
The materials of the coating liquid were mixed at the following mass ratio and stirred for 30 minutes or more. Subsequently, the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare the coating solution S.
・ Toluene 24.4% by mass
・ Methyl ethyl ketone 24.3% by mass
・ Polyester polyurethane resin 23.7% by mass
(Toyobo, UR-8200, solid content: 30% by mass)
・ Isocyanate-based crosslinking agent 15.6% by mass
(Nippon Polyurethane, Coronate L, solid content: 75% by mass)
・ Azochrome complex dye 7.0% by mass
(VALIFAST BLACK 3810 manufactured by Orient Chemical Industries)
・ Silicone surfactant 5.0% by mass
(BYK, BYK-370 solid content concentration: 25% by mass)

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. The excessively added surface activity was deposited on the surface, and the sealing material adhesion was remarkably lowered.

(Comparative Example 6)
It takes 12 seconds to enter the drying oven, 60 seconds with hot air of 5 m / second at 40 ° C., 60 seconds with hot air of 20 m / second at 150 ° C., and 30 seconds with hot air of 20 m / second at 90 ° C. An easily adhesive film was obtained in the same manner as in Example 2 except that the film was dried.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Since a large amount of the surfactant was deposited on the surface of the coating film, the water contact angle was increased, and therefore, the sealant adhesion was significantly reduced.

(Comparative Example 7)
Time to enter the drying oven is 0.5 second, 60 seconds with hot air of 5 m / second at 40 ° C., 60 seconds with hot air of 20 m / second at 150 ° C., and 30 seconds with hot air of 20 m / second at 90 ° C. An easy-adhesive film was obtained in the same manner as in Example 2 except that it was allowed to pass through and dried.

  Table 1 shows the pigment concentration in the coating layer, the type of surfactant, the amount added, the presence or absence of a crosslinking agent, the raw material used, and the processing conditions. In addition, Table 2 shows the physical properties of the easily adhesive film obtained. Coating spots and repellencies were seen on the entire surface of the coating film, and the adhesion after the durability evaluation was significantly reduced.

  When the easy-adhesive film of the present invention is used as a solar battery back sheet member, it is possible to prevent poor adhesion due to a coating defect on the adhesive surface of the back sheet and the sealing material, and thus the adhesion to the sealing material over a long period of time. By holding the value, it is possible to contribute to extending the life of the solar cell module. In addition, even if the easy-adhesive film is stored for a long period of time, it has good adhesion to the sealing material, so it becomes possible to create a stable solar cell module regardless of the storage period of the backsheet, contributing to the industry. It is great to do.

Claims (5)

An easy-adhesion film having a coating layer on at least one side of a translucent polyester film substrate, wherein the polyester film substrate is a polyethylene terephthalate film substrate, and the coating layer contains a dye and a surfactant, And the water contact angle of the said application layer is 80 degrees or more and 100 degrees or less, OD value is 1.0 or more and 4.0 or less, The easily adhesive film characterized by the above-mentioned. The easily adhesive film according to claim 1, wherein the surfactant is a silicone-based surfactant. The easily adhesive film according to claim 1 or 2, wherein the surfactant is a silicone-based surfactant containing a hydroxyl group. The easily adhesive film according to any one of claims 1 to 3, wherein the coating layer contains a polyester resin or a polyester polyurethane resin and a crosslinking agent. A method for producing an easy-adhesion film having a coating layer on at least one surface of a translucent polyester film substrate, wherein the polyester film substrate is a polyethylene terephthalate film substrate, and a water contact angle of the coating layer is 80 ° or more and 100 A method for producing an easy-adhesive film, which has an OD value of 1.0 or more and 4.0 or less and includes the following two steps when the coating layer is formed.
(1) A step of applying a coating liquid containing at least a pigment and a surfactant (2) A step of drying after applying the coating liquid to the drying oven for 1 second to 10 seconds