JP2010100032A - Method for manufacturing adhesive sheet for solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the method for manufacturing an adhesive sheet for solar cell, with which the adhesive sheet for solar cell, the shrinkage with heat of which is small, can be manufactured with favorable productivity rate. <P>SOLUTION: The method for manufacturing this adhesive sheet for solar cell includes: the melt-kneading of a resin composition containing ethylene-based copolymer and an organic peroxide by being fed to an extruder; the extrusion of a resin sheet from a mold attached to the extruder; the seating of the resin sheet on the surface of a cooling roll at the temperature higher by 25-50°C than the melting point of the ethylene-based copolymer; the cooling of the resin sheet during its transportation by seating it on the surface of the cooling roll; and the forming of embossing onto the resin sheet by supplying it between the cooling roll and an embossing roll under the state that the resin sheet is cooled to a temperature, which is equal to or more than temperature lower by 20°C than the melting point of an ethylene-based polymer, and a temperature, which is equal to or less than the temperature higher by 15°C than the melting point of the ethylene-based polymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a solar cell adhesive sheet.

  The solar cell module has a solar cell adhesive sheet on both sides of the solar cell element, an upper transparent protective material on the upper surface of the upper solar cell adhesive sheet, and a lower substrate on the lower surface of the lower solar cell adhesive sheet. The laminate obtained by stacking the protective materials is heated while degassing under reduced pressure, and the upper transparent protective material and the lower substrate protective material are laminated and integrated on the upper and lower surfaces of the solar cell element via an adhesive sheet for solar cells. It is manufactured by letting

  As a manufacturing method of the adhesive sheet for solar cells used for such a solar cell module, for example, in Patent Document 1, a molten web formed by extruding a molding material such as an ethylene copolymer from an extruder is used as a cooling rubber roll. A method for producing a polypropylene-based resin-filled adhesive sheet polymerized using a metallocene compound as a polymerization catalyst for a solar cell module that is supplied with a release paper between a pressure-bonded rubber roll and embossed and cooled and solidified is disclosed.

  In Patent Document 2, a molding material such as an ethylene copolymer is extruded from an extruder, formed into a film with an embossing roll and a casting roll, and then irradiated with a predetermined amount of radiation to promote radiation crosslinking in a low temperature range. A method for controlling the fluidity and heat shrinkability of the resin is disclosed.

  Furthermore, Patent Document 3 discloses a sun embossed on the surface of a resin sheet by pressing a resin sheet obtained by extruding a composition for forming a filler containing a thermoplastic resin against the surface of a shaping roller with a pressure roller. A manufacturing method of a battery module filler sheet, which has a predetermined temperature difference between the surface temperature of the shaping roller and the pressure roller, is disclosed.

  However, in the manufacturing methods described in Patent Documents 1 to 3, a molten resin sheet extruded from an extruder is supplied between an embossing roll and a pressure roll in contact with the embossing roll, thereby cooling the resin sheet. And embossing are performed at the same time.

  In the above manufacturing method, the resin sheet in a molten state extruded from the mold of the extruder is directly supplied between the embossing roll and the pressure roll after being extruded from the mold. Is rapidly cooled with tension applied between the mold and the roll.

  Accordingly, a large amount of residual strain remains in the obtained adhesive sheet for solar cells, and the heat applied in the manufacturing process of the solar cell module causes shrinkage or wrinkles on the sheet, resulting in insufficient sealing of the solar cell elements or There is a problem that the integration of the upper transparent protective material and the lower substrate protective material becomes insufficient.

  In order to reduce the shrinkage due to heating of the obtained solar cell adhesive sheet, it is conceivable to reduce the production rate of the solar cell adhesive sheet, but this causes a problem that the productivity is lowered.

JP 59-22978 JP-A-8-283696 JP 2007-245555 A

  This invention provides the manufacturing method of the adhesive sheet for solar cells which can manufacture the adhesive sheet for solar cells with the small shrinkage by heating with sufficient productivity.

  The method for producing an adhesive sheet for a solar cell of the present invention includes a resin composition containing an ethylene copolymer and an organic peroxide supplied to an extruder, melt-kneaded, and from a mold attached to the extruder. A resin sheet is extruded, and the resin sheet is placed on the surface of the cooling roll at a temperature 25 to 50 ° C. higher than the melting point of the ethylene copolymer, and the resin sheet is conveyed on the surface of the cooling roll. The cooling roll and the embossing roll are cooled in a state where the resin sheet is cooled to a temperature not lower than 20 ° C lower than the melting point of the ethylene polymer and not higher than 15 ° C higher than the melting point of the ethylene polymer. The emboss is formed on the resin sheet.

  In the manufacturing method of the said adhesive sheet for solar cells, the resin sheet mounted on the surface of the cooling roll is heat-retained from the outer surface side by a heat retention means.

  In the manufacturing method of the adhesive sheet for solar cells, the resin sheet on which the emboss is formed is annealed at a temperature that is 10 ° C. lower than the melting point of the ethylene copolymer and 10 ° C. lower than the melting point.

  The manufacturing method of the adhesive sheet for solar cells of this invention adjusts the resin sheet extruded from the extruder so that it may become 25-50 degreeC higher than melting | fusing point of the ethylene-type copolymer which comprises this resin sheet. And put it on the cooling roll.

  And the resin sheet is gradually cooled over time by conveying in the state which mounted the resin sheet on the cooling roll, and the residual distortion which exists in the resin sheet is eased.

  Thereafter, the resin sheet is cooled on a cooling roll so that the temperature is 20 ° C. lower than the melting point of the ethylene polymer constituting the resin sheet and 15 ° C. lower than the melting point of the ethylene polymer. After that, since the resin sheet is supplied between the cooling roll and the embossing roll in this state to form the embossing on the resin sheet, the resulting solar cell adhesive sheet has little residual distortion and is not shrunk by heating. There are few things.

  Therefore, the solar cell adhesive sheet obtained by the method for manufacturing the solar cell adhesive sheet of the present invention hardly undergoes shrinkage due to heat applied when the solar cell module is manufactured, and the solar cell element is converted into a solar cell. The upper transparent protective material and the lower substrate protective material are integrated with the upper and lower surfaces of the solar cell element via the solar cell adhesive sheet to ensure the solar cell module. Can be manufactured.

  Further, by keeping the resin sheet placed on the surface of the cooling roll from the outer surface side by the heat retaining means, the outer surface side of the resin sheet that is in contact with the air becomes the cooling roll while cooling the resin sheet on the cooling roll. It is possible to prevent the resin sheet from being cooled excessively than the inner side surface of the resin sheet in contact with the resin sheet, and to cool the resin sheet to a proper temperature substantially uniformly in the thickness direction on the cooling roll.

  Since the resin sheet is cooled to an appropriate temperature on the outer surface side and is substantially uniformly cooled in the thickness direction, the resin sheet is supplied between the embossing roll and the cooling roll to emboss the surface of the resin sheet. Can be more reliably formed.

  Furthermore, since the resin sheet is cooled substantially uniformly in the thickness direction on the cooling roll, the residual strain existing in the resin sheet can be more reliably alleviated.

It is the model side view which showed an example of the manufacturing apparatus of the adhesive sheet for solar cells. It is the model side view which showed another example of the manufacturing apparatus of the adhesive sheet for solar cells.

  One example of a method for producing a solar cell adhesive sheet of the present invention will be described with reference to the drawings. FIG. 1 shows an example of an apparatus for producing an adhesive sheet for solar cells, and a mold 2 is attached to the tip of an extruder 1. And the cooling roll 4 is arrange | positioned in the extrusion direction of the metal mold | die 2, and the embossing roll 5 is arrange | positioned in the state which contact | connected this cooling roll 4. FIG. An air knife 3 is disposed on the side of the cooling roll 4. Furthermore, an annealing roll 6 and a take-up roll 7 are sequentially disposed on the downstream side in the conveying direction of the adhesive sheet A for solar cells.

  First, a resin composition containing an ethylene copolymer and an organic peroxide is supplied to the extruder 1. This ethylene-based copolymer is a copolymer of ethylene and a copolymerizable monomer that can be copolymerized with ethylene. Such a copolymerizable monomer is not particularly limited, and examples thereof include vinyl acetate, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, maleic acid, maleic anhydride, maleic ester and the like. preferable. In addition, the said copolymerizable monomer may be copolymerized with ethylene independently, or 2 or more types may be copolymerized with ethylene.

  Further, if the amount of the copolymerizable monomer contained in the ethylene copolymer is small, the resulting solar cell adhesive sheet lacks transparency, and the power generation efficiency of the solar cell element may be reduced. If the amount is too large, the film-forming stability and mechanical strength of the adhesive sheet for solar cells may be insufficient, so 5 to 50% by weight is preferable.

  And, if the melt flow rate of the ethylene copolymer is small, the film forming stability of the adhesive sheet for solar cells may be reduced, and if the melt flow rate is large, the mechanical strength of the adhesive sheet for solar cells is insufficient. Therefore, 1 to 100 g / 10 min is preferable. The melt flow rate of the ethylene copolymer in the present invention refers to a value measured under conditions of a temperature of 190 ° C. and a load of 2.16 kgf (21.18 N) according to JIS K7210.

  Examples of the organic peroxide include dicumyl peroxide (136 ° C.), t-butyl peroxy-2-ethylhexyl monocarbonate (119 ° C.), t-butyl peroxybenzoate (125 ° C.), 1,1- Bis (t-butylperoxy) -2-methylcyclohexane (102 ° C.), 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (106 ° C.), 1,1-bis ( t-hexylperoxy) cyclohexane (107 ° C.), 1,1-bis (t-butylperoxy) cyclohexane (111 ° C.), 2,2-bis (4,4-bis (t-butylperoxy) cyclohexyl) Propane (114 ° C), t-hexylperoxyisopropyl monocarbonate (115 ° C), t-butylperoxyisopropyl Carbonate (118 ° C), t-butylperoxylaurate (118 ° C), 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane (119 ° C), t-hexylperoxybenzoate (119 ° C) ), T-butylperoxymaleic acid (119 ° C.), t-butylperoxy-3,5,5-trimethylhexanoate (119 ° C.), t-butylperoxyacetate (121 ° C.), 2,2- Bis (t-butylperoxy) butane (122 ° C.), n-butyl-4,4-bis (t-butylperoxy) valerate (127 ° C.), di-t-hexyl peroxide (136 ° C.), t- Butyl cumyl peroxide (137 ° C.), bis (2-t-butylperoxyisopropyl) benzene (138 ° C.), 2,5-dimethyl-2,5- (T-butylperoxy) hexane (138 ° C.), di-t-butyl peroxide (144 ° C.), 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 (150 ° C.) ), P-menthane hydroperoxide (151 ° C.), etc., and may be used alone or in combination of two or more. The temperature in the parenthesis represents a 1 hour half-life temperature.

  If the content of the organic peroxide in the resin composition is small, the crosslinking (gel fraction) of the ethylene copolymer becomes insufficient during the production of the solar cell module, and the solar cell adhesive sheet Insufficient heat resistance may reduce the durability of the resulting solar cell module.In many cases, acetone or carbon dioxide is decomposed along with the decomposition of the organic peroxide during the thermocompression bonding process during the production of the solar cell module. A large amount of low molecular weight compounds such as carbon are generated, bubble expansion occurs between the facing surfaces of the solar cell element and the protective material, the adhesion between the solar cell element and the protective material is reduced, and the protective function of the solar cell element is improved. Or the solar cell adhesive sheet may be discolored and the power generation efficiency of the solar cell element may be reduced. Therefore, 0.1 to 3 parts by weight is preferable with respect to 100 parts by weight of the ethylene copolymer, 0.3-1 More preferably 5 parts by weight, the gel fraction after the production of this time the solar cell module is preferably 70% by weight or more.

  In addition, the resin composition may contain an anti-scorch agent as long as it does not inhibit the crosslinking of the ethylene copolymer, but preferably does not contain an anti-scorch agent.

  Furthermore, as long as the resin composition is within a range that does not impair the physical properties of the solar cell adhesive sheet A, a crosslinking aid, a coupling agent, and 2,6-di-t-butyl-4-methyl are added as necessary. Additives such as antioxidants such as phenol and ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone may be added.

  Examples of the crosslinking aid include polyfunctional monomers having two or more allyl groups, vinyl groups, acryloyl groups or methacryloyl groups, which stabilize polymer radicals to increase crosslinking efficiency and concentrate crosslinking points. Accelerates gel formation. Examples of the polyfunctional monomer include 1,6-hexanediol di (meth) acrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and di Pentaerythritol hexa (meth) acrylate, (meth) acrylate such as ε-caprolactone modified dipentaerythritol, (meth) acrylate of alkyl modified dipentaerythritol, diallyl phthalate, diallyl itaconate, diallyl maleate, triallyl isocyanurate, Examples include triallyl cyanurate, triallyl phosphate, and divinylbenzene. These may be used alone or in combination of two or more.

  The coupling agent is added for the purpose of improving the adhesion of the solar cell adhesive sheet, and the coupling agent is one or more selected from the group consisting of an amino group, a glycidyl group, a methacryloxy group, and a mercapto group. A silane coupling agent having the following functional group is preferably used.

  Examples of the silane coupling agent include 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like. Even if it is used, 2 or more types may be used together.

  Next, the resin composition is melt-kneaded in the extruder 1, and the resin sheet B is continuously extruded from the mold 2 attached to the extruder 1. The temperature of the resin sheet B when extruding the resin sheet B from the mold 2 is the same as the temperature of the resin sheet B when contacting the surface of the cooling roll 4 for the first time. The temperature is adjusted to be 25 to 50 ° C. higher than the melting point of the coalescence. In addition, the temperature of the resin sheet B when contacting the surface of the cooling roll 4 for the first time refers to the surface temperature on the opposite side to the cooling roll 4.

  Then, the resin sheet B extruded from the mold 2 is supplied to the surface of the cooling roll 4. Note that air is blown from the air knife 3 to the resin sheet B so that the resin sheet B is brought into close contact with the surface of the cooling roll 4 so that an air pool does not occur at the interface between the resin sheet B and the cooling roll. Note that an air chamber, electrostatic pinning, or the like may be used instead of the air knife.

  The temperature of the resin sheet B when the resin sheet B comes into contact with the surface of the cooling roll 4 for the first time is 25 to 50 ° C. higher than the melting point of the ethylene copolymer constituting the resin sheet B.

  This is because when the temperature of the resin sheet B at the first contact with the cooling roll 4 is low, the residual strain existing in the resin sheet is insufficiently relaxed. Since the oxide is decomposed and the crosslinking proceeds and the residual strain existing in the resin sheet is insufficiently relaxed, the temperature is 25 to 50 ° C. higher than the melting point of the ethylene copolymer constituting the resin sheet B. The temperature is preferably 30 to 40 ° C. higher than the melting point of the ethylene copolymer. In addition, melting | fusing point of an ethylene-type copolymer says the peak temperature of the DSC (differential scanning calorimeter) curve measured based on JISK7121. When the resin sheet B contains two or more kinds of ethylene copolymers, a DSC (differential scanning calorimeter) curve is measured for each ethylene copolymer in accordance with JIS K7121, The peak temperature of the DSC curve of the ethylene copolymer showing the highest peak among the DSC curve peaks of the copolymer.

  And the resin sheet B supplied to the surface of the cooling roll 4 is conveyed in the state mounted on the surface of the cooling roll 4 over the whole width, and the resin sheet B is gradually cooled by the cooling roll 4 during this conveyance. Thus, the residual strain existing in the resin sheet B is alleviated.

  Here, the temperature of the cooling roll 4 is a resin sheet when the resin sheet B placed on the surface of the cooling roll 4 and conveyed is supplied between the cooling roll 4 and the embossing roll 5 as described later. The temperature of B is adjusted to be not less than 20 ° C. lower than the melting point of the ethylene copolymer constituting the resin sheet B and not more than 15 ° C. higher than the melting point.

  The temperature of the cooling roll 4 is appropriately adjusted according to the temperature of the resin sheet B and the rotation speed of the cooling roll 4, but if it is low, the resin sheet in contact with the cooling roll is rapidly cooled, and residual strain existing in the resin sheet is present. If it is not sufficiently relaxed, and if it is high, embossing may not be sufficiently formed on the resin sheet by the embossing roll, so a temperature lower by 10 to 50 ° C. than the melting point of the ethylene copolymer is preferable.

  Further, as shown in FIG. 2, the resin sheet B placed on the cooling roll 4 is on the outer surface side, that is, until the resin sheet B comes into contact with the embossing roll 5 after contacting the cooling roll 4. In order to prevent excessive cooling on the surface side in contact with air (surface opposite to the cooling roll 4), it is preferable to keep the resin sheet warm by the heat retaining means 8 from the outer surface side.

  When the resin sheet B is kept warm from the outer surface side, the outer surface of the resin sheet B is 20 ° C. higher than the melting point of the ethylene-based copolymer constituting the resin sheet B and 20 ° C. higher than the melting point. It is preferable to adjust so that it may become the following.

  Thus, by keeping the resin sheet B warm from the outer surface side, the resin sheet B can be cooled substantially uniformly in the thickness direction, and in the next step, the emboss is accurately formed on the resin sheet B by an embossing roll. be able to.

  Furthermore, since the resin sheet B can be cooled substantially uniformly in the thickness direction, the residual strain of the resin sheet B can be relaxed more reliably.

  The heat retaining means is not particularly limited as long as the resin sheet B can be kept warm from the outer surface side. For example, a hot air heating device that blows hot air on the resin sheet B, a near infrared ray, a far infrared ray, or the like is irradiated to the resin sheet B. Infrared irradiating device, a roll held at a predetermined temperature to be brought into contact with the outer surface of the resin sheet B, and the like. Further, as a heat retaining means, a heat retaining box may be provided so as to cover the resin sheet B along the resin sheet B placed on the cooling roll 4.

  In this way, the resin sheet B that has been gradually cooled over time on the surface of the cooling roll 4 to relieve the residual strain is formed between the cooling roll 4 and the embossing roll 5 rotating in contact with the cooling roll 4. Supplied in between.

  The temperature of the resin sheet B supplied between the cooling roll 4 and the embossing roll 5 and pressed in the thickness direction by the cooling roll 4 and the embossing roll 5 to form the embossing by the embossing roll 5 is the resin sheet B. The temperature is adjusted to be 20 ° C. lower than the melting point of the ethylene copolymer constituting B and 15 ° C. higher than the melting point of the ethylene copolymer. In addition, the temperature of the resin sheet B at the time of embossing means the surface temperature of the surface which contacts an embossing roll.

  This is because if the temperature of the resin sheet B when the emboss is formed by the cooling roll 4 and the embossing roll 5 is low, the formation of the emboss on the resin sheet may be insufficient, and if high, the resin sheet is soft. This is because even if the embossing is once formed by the embossing roll, the embossing disappears after that or the embossing depth becomes shallow, and the embossing with a sufficient depth may not be formed.

  The resin sheet B is passed between the cooling roll 4 and the embossing roll 5, and the embossed plate formed on the surface of the embossing roll 5 is transferred to the resin sheet B to form the embossing, thereby forming the adhesive sheet A for solar cells. Is manufactured, and then the solar cell adhesive sheet A is peeled off from the cooling roll 4 and conveyed on the surface of the embossing roll 5.

  At this time, the resin sheet B is supplied between the cooling roll 4 and the embossing roll 5 and embossed in a state cooled to a predetermined temperature as described above, and then discharged from between the cooling roll 4 and the embossing roll 5. Since the discharged adhesive sheet A for solar cells is sufficiently cooled, it is excellent in peelability to the roll, and the state in close contact with the cooling roll 4 is unexpectedly continued and conveyed to the cooling roll 4 side. There is no such thing, and it is smoothly peeled off from the surface of the cooling roll 4 and conveyed in a state of being in close contact with the surface of the embossing roll 5. And since the adhesive sheet A for solar cells is excellent in the peelability with respect to a roll, it can raise a conveyance speed and can aim at the improvement of production efficiency.

  At this time, if the temperature of the embossing roll 5 is low, the embossing may not be sufficiently formed on the resin sheet. If the temperature is high, the resin sheet is too soft and the embossing roll once forms the embossing roll. Or the embossing depth becomes shallow and embossing with a sufficient depth may not be formed. Therefore, a temperature lower by 10 to 60 ° C. than the melting point of the ethylene copolymer is preferable.

  Next, the solar cell adhesive sheet A is supplied to the annealing roll 6 and the solar cell adhesive sheet A is annealed. In addition, what is necessary is just to perform an annealing process as needed.

  If the temperature of the solar cell adhesive sheet A during the annealing process is low, the effect of the annealing process may not be exhibited. If the temperature is high, the solar cell adhesive sheet A may be difficult to convey. The temperature is preferably at least 10 ° C. lower than the melting point of the ethylene copolymer constituting the solar cell adhesive sheet and at most 10 ° C. higher than the melting point of the ethylene copolymer.

  And the adhesive sheet A for solar cells is continuously wound up by the winding roll 7, after performing an annealing process as mentioned above.

  In the solar cell adhesive sheet A thus obtained, the residual strain is generally relaxed, and the shrinkage hardly occurs by heating. And a solar cell module arrange | positions the solar cell adhesive sheets A and A on both surfaces of a solar cell element, an upper transparent protective material on the upper surface of the upper solar cell adhesive sheet A, and a lower solar cell adhesive The laminate obtained by overlaying the lower substrate protective material on the lower surface of the sheet A is heated while degassing under reduced pressure, and the upper transparent protective material and the lower substrate protective material are bonded to the upper and lower surfaces of the solar cell element for solar cells. It is manufactured by stacking and integrating sheets A and A.

  However, since the obtained solar cell adhesive sheet A is hardly contracted by heating, the solar cell element can be reliably sealed by the solar cell adhesive sheets A, A, and the upper transparent protective material and The lower substrate protective material can be firmly integrated with the solar cell adhesive sheets A and A.

  In addition, although the case where the resin sheet B is a single-layer sheet was described above, even if the resin sheet is formed by co-extrusion from a mold using a plurality of extruders as an extruder, a plurality of layers are laminated and integrated. Good.

Example 1
The solar cell adhesive sheet A was manufactured using the manufacturing apparatus shown in FIG. Specifically, ethylene-vinyl acetate copolymer (vinyl acetate content: 27% by weight, melt flow rate: 13 g / 10 minutes, melting point: 72 ° C.) 100 parts by weight, t-butylperoxy-2-ethylhexyl mono Carbonate (1 hour half-life temperature: 119 ° C.) 0.5 part by weight, 2,4-diphenyl-4-methyl-1-pentene 0.02 part by weight, 2,6-di-t-butyl-4-methylphenol A resin composition comprising 0.1 parts by weight and 0.3 parts by weight of 2-hydroxy-4-methoxybenzophenone is supplied to the extruder 1 and melt-kneaded at 112 ° C., connected to the extruder 1 and brought to 110 ° C. The resin sheet B was extruded from the held mold 2.

  The resin sheet B was placed on the surface of the cooling roll 4 held at 50 ° C. in close contact with the air knife 3 over its entire width and gradually cooled while being conveyed in the direction of the embossing roll 5. In addition, the temperature of the resin sheet B when the resin sheet B contacted the cooling roll 4 for the first time was 109 degreeC.

  Next, the resin sheet B conveyed while being in close contact with the surface of the cooling roll 4 is supplied between the cooling roll 4 and the embossing roll 5 that rotates in contact with the surface and has an embossed plate formed on the surface. did.

  Then, the embossed plate of the embossing roll 5 was transferred to the surface of the resin sheet B to form embossing, and then the solar cell adhesive sheet A was discharged from between the cooling roll 4 and the embossing roll 5. In addition, the temperature of the resin sheet B at the time of the resin sheet B contacting the cooling roll 4 and the embossing roll 5 for the first time was 78 degreeC.

  Next, the adhesive sheet A for solar cells was conveyed from the cooling roll 4 while being in close contact with the surface of the embossing roll 5. Thereafter, the solar cell adhesive sheet A is supplied to the annealing roll 6 maintained at 65 ° C. and is conveyed while being in close contact with the surface of the annealing roll 6, and is subjected to annealing treatment and then conveyed at 10 m / min. The film was continuously wound on the winding roll 7 at a speed.

(Example 2)
Except that the solar cell adhesive sheet A is peeled off from the embossing roll 5 and the solar cell adhesive sheet A is not wound on the winding roll 7 without being annealed without the annealing roll 6 being provided. In the same manner as in Example 1, a solar cell adhesive sheet A was obtained.

(Example 3)
An ethylene-vinyl acetate copolymer (vinyl acetate content: 34% by weight, melt flow rate: 40 g / 10 min, melting point: 60 ° C.) was used, and the resin composition was replaced with 112 ° C. in the extruder 1. It was melt kneaded at 95 ° C., the mold 2 was maintained at 95 ° C. instead of 110 ° C., the cooling roll 4 was maintained at 30 ° C. instead of 50 ° C., and the embossing roll 5 was maintained at 25 ° C. instead of 30 ° C. Adhesion for solar cells in the same manner as in Example 1 except that the temperature was maintained at ℃, the annealing roll 6 was maintained at 55 ℃ instead of 65 ℃, and the conveyance speed was 12 m / min instead of 10 m / min. Sheet A was obtained. In addition, the temperature of the resin sheet B at the time of the resin sheet B contacting the cooling roll 4 for the first time was 88 degreeC. The temperature of the resin sheet B when the resin sheet B first contacted both the cooling roll 4 and the embossing roll 5 was 56 ° C.

Example 4
Except that the solar cell adhesive sheet A is peeled off from the embossing roll 5 and the solar cell adhesive sheet A is not wound on the winding roll 7 without being annealed without the annealing roll 6 being provided. In the same manner as in Example 3, a solar cell adhesive sheet A was obtained.

(Example 5)
The temperature of the cooling roll was set to 45 ° C. instead of 50 ° C., the hot air heating device 8 was disposed below the cooling roll 4, the resin sheet B before passing through the air knife 3 and contacting the embossing roll 5 Adhesive sheet A for solar cells was obtained in the same manner as in Example 1 except that hot air of 70 ° C. was blown from the hot air heating device to the outer surface and the resin sheet B was kept warm from the outer surface side. In addition, the temperature of the outer surface of the resin sheet B sprayed with hot air was 87 ° C. The temperature of the resin sheet B when the resin sheet B first contacted both the cooling roll 4 and the embossing roll 5 was 84 ° C.

(Comparative Example 1)
Implemented except that the cooling roll 4 was maintained at 65 ° C. instead of 50 ° C., the embossing roll 5 was maintained at 60 ° C. instead of 30 ° C., and the conveyance speed was 3 m / min instead of 10 m / min. In the same manner as in Example 1, a solar cell adhesive sheet A was obtained. In addition, the temperature of the resin sheet B when the resin sheet B contacted the cooling roll 4 for the first time was 109 degreeC. The temperature of the resin sheet B when the resin sheet B first contacted both the cooling roll 4 and the embossing roll 5 was 109 ° C.

(Comparative Example 2)
Comparison was made except that the solar cell adhesive sheet A was peeled off from the embossing roll 5 and the solar cell adhesive sheet A was taken up on the take-up roll 7 without being annealed without the annealing roll 6 being provided. In the same manner as in Example 1, a solar cell adhesive sheet A was obtained.

(Comparative Example 3)
Adhesive sheet A for solar cells was obtained in the same manner as in Example 1 except that the conveyance speed was 5 m / min instead of 10 m / min. The emboss was not formed in the surface of the adhesive sheet A for solar cells.

  The temperature at which the resin sheet B first contacted the cooling roll 4 was 109 ° C. The temperature of the resin sheet B when the resin sheet B first contacted both the cooling roll 4 and the embossing roll 5 was 45 ° C.

(Comparative Example 4)
The resin composition was melt kneaded at 90 ° C. instead of 112 ° C. in the extruder 1, the mold 2 was maintained at 90 ° C. instead of 110 ° C., and the conveyance speed was 3 m / min instead of 10 m / min. The solar cell adhesive sheet A was manufactured in the same manner as in Example 1 except that the resin sheet B was poorly spread between the mold 2 and the cooling roll 4, and the resin sheet B and the sun were uniform. The battery adhesive sheet A could not be obtained. In addition, the temperature of the resin sheet B at the time of the resin sheet B contacting the cooling roll 4 for the first time was 85 degreeC.

(Comparative Example 5)
Adhesion for solar cells in the same manner as in Example 1 except that the resin composition was melt-kneaded at 135 ° C instead of 112 ° C in the extruder 1 and the mold 2 was maintained at 135 ° C instead of 110 ° C. Although it tried to manufacture the sheet | seat A, gel generate | occur | produced 30 minutes after the manufacture start, and the favorable adhesive sheet A for solar cells was not able to be obtained.

  In addition, the temperature of the resin sheet B at the time of the resin sheet B contacting the cooling roll 4 for the first time was 131 degreeC. The temperature of the resin sheet B when the resin sheet B first contacted both the cooling roll 4 and the embossing roll 5 was 103 ° C.

  The heating shrinkage and embossability of the obtained solar cell adhesive sheet A were measured in the following manner, and the results are shown in Table 1. In the column of “contact temperature with cooling roll” in Table 1, the upper column shows “temperature of resin sheet B when resin sheet B first contacts cooling roll 4”, and the lower column shows "The temperature difference between the temperature of the resin sheet B when the resin sheet B first contacts the cooling roll 4 and the melting point of the ethylene-vinyl acetate copolymer constituting the resin sheet B" is described.

  In the column of “Embossing temperature” in Table 1, the upper column shows “the temperature of the resin sheet B when the resin sheet B first contacts both the cooling roll 4 and the embossing roll 5”, and the lower column. “The temperature difference between the temperature of the resin sheet B when the resin sheet B first contacts both the cooling roll 4 and the embossing roll 5 and the melting point of the ethylene-vinyl acetate copolymer constituting the resin sheet B”. Was described.

(Heat shrinkability)
A planar square test piece having a side of 120 mm was cut out from the obtained solar cell adhesive sheet. Two straight lines parallel to each other were drawn on the test piece with an interval of 100 mm.

Next, the test piece was placed on a polytetrafluoroethylene sheet on which talc disposed in an oven heated to 60 ° C. was sprinkled for 2.5 minutes. Thereafter, the test piece was taken out of the oven and cooled. The distance A (mm) between two straight lines drawn on the test piece was measured with a caliper, and the heat shrinkage rate was calculated based on the following formula.
Heat shrinkage rate (%) = 100 × (100−A) / 100

(Emboss shapeability)
The maximum embossed depth of the obtained solar cell adhesive sheet was measured with a laser microscope.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Mold 3 Air knife 4 Cooling roll 5 Embossing roll 6 Annealing roll 7 Winding roll 8 Heat insulation means A Adhesive sheet for solar cells B Resin sheet

Claims (3)

A resin composition containing an ethylene copolymer and an organic peroxide is supplied to an extruder and melt-kneaded, the resin sheet is extruded from a mold attached to the extruder, and the resin sheet is extruded into the ethylene copolymer. The resin sheet is placed on the surface of the cooling roll at a temperature 25 to 50 ° C. higher than the melting point of the polymer, and is cooled while being transported while the resin sheet is placed on the surface of the cooling roll. The emboss is formed on the resin sheet by supplying it between the cooling roll and the embossing roll in a state where it is cooled to a temperature that is 20 ° C lower than the melting point and 15 ° C lower than the melting point of the ethylene polymer. The manufacturing method of the adhesive sheet for solar cells characterized by performing. The method for producing an adhesive sheet for a solar cell according to claim 1, wherein the resin sheet placed on the surface of the cooling roll is kept warm from the outer surface side by a heat retaining means. The resin sheet on which embossing is formed is annealed at a temperature not lower than 10 ° C lower than the melting point of the ethylene copolymer and not higher than 10 ° C higher than the melting point. Manufacturing method for solar cell adhesive sheet.

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