JP2008222880A - Method for producing laminate and laminate obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a laminate by which a resin film and a photo-curing composition can simply and efficiently be laminated and to provide the laminate obtained thereby. <P>SOLUTION: The laminate in which a resin layer having fine unevennesses is laminated onto the surface of the resin film 2 is produced. The method comprises passing through 5 steps (a coating step of coating the mold surface 8a of a mold 8 having fine unevennesses on the surface 8a with a liquid photo-curing composition, a contacting step of opposing and bringing the surface of the coated photo-curing composition into contact with the surface of the resin film 2 delivered from a delivery roll 1 by a prescribed length, a resin layer-forming step of curing the photo-curing composition by light irradiation and forming the resin layer, a peeling step of peeling the resin film 2 to which the resin layer is applied from the surface 8a of the mold 8 and a winding step of carrying out movement of the resin film 2 and performing winding for winding of the laminate onto a winding roll 3) in the order. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a laminate in which a resin layer having fine irregularities is formed on the surface of a resin film, and a laminate obtained thereby.

  In recent years, solar cells have attracted attention as environmental measures such as prevention of global warming and energy measures such as fossil fuel substitution. At present, a panel using a glass substrate is generally used as a solar cell, but not only is there a risk of breaking the glass, but because the glass itself is heavy, for example, when installing a solar cell panel on a roof, it is special. There was a limit to cost reduction such as the need for extra reinforcement.

  Therefore, recently, there is an active movement to replace the glass substrate of the solar cell panel with a substrate made of a resin film. By changing to a resin film, it is safe to break and safe, can be significantly reduced in weight and thickness, and can be increased in area. In addition, it has the effect that it has flexibility and can be attached to a curved surface.

  Usually, a solar cell has a transparent electrode made of a metal oxide such as zinc oxide on a substrate, a photoelectric conversion layer made of amorphous silicon or the like, and a back surface reflective electrode selected from gold, silver, copper, etc. in this order ( A structure formed by a superstrate type) or a reverse order (called a substrate type) is generally used.

  In such a solar cell, photoelectric conversion efficiency is important, and a technique related to a metal electrode or a transparent electrode is important for improving the efficiency. In particular, the transparent electrode and its surface shape greatly affect the conversion efficiency.

  The above transparent electrode is required to have a low resistance in order to increase the external extraction efficiency of the generated electric power, and is required to have transparency enough to transmit sunlight.

  Therefore, it is desirable to promote crystal growth by forming a metal oxide film at a high temperature in order to reduce the resistance and transparency of the transparent electrode.

  However, when a resin film is used as the substrate, if the film is formed at a high temperature, the resin film is discolored and the light transmittance is reduced, or the substrate with a transparent electrode obtained due to insufficient heat resistance is warped or undulated. Or problems such as cracks occurring in the transparent electrode.

  The surface shape of the transparent electrode is also important for improving the photoelectric conversion efficiency. In order to efficiently send the received light to the photoelectric conversion layer, it is desirable that the shape of the surface of the transparent electrode, which is a boundary with the photoelectric conversion layer, be a structure that easily scatters light. That is, the surface of the transparent electrode needs to be controlled to an appropriate surface roughness (RMS). When the surface roughness is controlled, light scattering occurs when sunlight passes through the transparent electrode, so that the optical path length in the photoelectric conversion layer becomes long, so that light can be used effectively and photoelectric conversion of solar cells. Efficiency will be excellent.

  As a method for controlling the surface roughness, when using a glass substrate, the surface of the transparent electrode made of a metal oxide formed on the glass substrate is roughened into fine irregularities to increase light scattering. Currently, when a metal oxide is formed on a glass substrate at a high temperature, a technique for forming an uneven shape (texture) by controlling crystal growth of the metal oxide is used.

  However, in the above method, high-temperature film formation of 300 ° C. or more is necessary for crystal growth of the metal oxide, and this method is difficult to use for a resin film. Therefore, when a resin film is used as a substrate, a method of forming a metal oxide after forming a texture on the substrate itself has been proposed as an alternative method of texture formation (see, for example, Patent Documents 1 to 3). ).

  However, in the methods disclosed in Patent Documents 1 to 3 described above, the texture forming process is complicated, which causes a cost increase, and there is a problem that it is difficult to transfer the texture according to the matrix. Moreover, since the adhesiveness between the resin film and the texture layer is insufficient, there is a concern that the texture layer may be peeled off from the resin film.

  Therefore, the present applicant has a layer structure of a resin film, a textured layer having irregularities, and a layer made of a metal oxide, and the transparent electrode substrate for solar cells, wherein the textured layer is obtained by curing the photocurable composition. Has already been proposed (see, for example, Patent Document 4).

In this material, a photocurable composition is used as a texture layer, and a texture layer formed by photocuring the photocurable composition is provided. Therefore, there is no coloring or deformation, excellent appearance characteristics, low resistance, and photoelectric conversion. The transparent electrode substrate (laminated body) for solar cells excellent in efficiency is obtained.
JP 2003-298084 A JP 2003-298085 A JP 2003-298086 A Japanese Patent Application No. 2006-345437

  However, in the above transparent electrode substrate for a solar cell, when manufacturing the substrate (a laminate comprising a resin film and a textured layer having irregularities), a resin layer comprising a resin film and a photocurable composition, Is required from the viewpoint of increasing the production amount of the transparent electrode substrate for solar cells.

  Then, development of the manufacturing method which can laminate | stack easily and efficiently the resin layer which consists of a resin film and a photocurable composition is calculated | required.

  This invention is made | formed in view of such a situation, The manufacturing method of the laminated body which can laminate | stack the resin film and the resin layer which consists of a photocurable composition simply and efficiently, and the laminated body obtained by this The purpose is to provide.

  However, as a result of intensive studies in view of the above circumstances, the present inventors have conveyed the resin film on a roll-to-roll basis, and by using the photocurable composition for the formation of fine irregularities (texture layer), The inventors have found that a laminate of a resin film and a resin layer having fine irregularities can be efficiently produced, and completed the present invention.

That is, the gist of the present invention is that a laminate having a resin layer having a fine concavo-convex formed of a photocurable composition on the surface of a resin film is manufactured through the following five steps. The production method is the first gist, and the laminate obtained by this production method is the second gist.
1. A coating process in which a liquid photocurable composition is coated on the mold surface of a mold having fine irregularities on the surface.
2. The contact process which makes the surface of the resin film sent out predetermined length from one roll face and contact the surface of the said apply | coated photocurable composition.
3. A resin layer forming step of forming a resin layer made of the photocurable composition by curing the photocurable composition by light irradiation after the contact step.
4). The peeling process which peels the resin film to which the said resin layer adhered after the said resin layer formation process from the surface of a type | mold.
5. A winding step of performing the movement of the resin film and the winding of winding the laminate of the resin film and the resin layer around the other roll after the peeling step.

  According to the production method of the present invention, a resin film and a resin layer composed of a photocurable composition can be easily and efficiently laminated. In addition, the laminate obtained by this production method has no appearance of coloring or deformation, has excellent appearance characteristics, has low resistance, and has excellent photoelectric conversion efficiency when used as a solar cell, particularly a substrate for a solar cell. As very useful.

  Next, the best mode for carrying out the present invention will be described. However, the present invention is not limited to this embodiment.

  FIG. 1 shows a laminating apparatus used in an embodiment of a method for producing a laminate according to the present invention. In FIG. 1, 1 is a delivery roll (one roll), and the belt-shaped resin film 2 is wound around it. Reference numeral 3 denotes a take-up roll (the other roll) disposed in a state of being opposed to each other with a predetermined space between the feed roll 1 and the resin film 2 wound around the feed roll 1. It acts to wind up. The take-up roll 3 has a structure that can be rotated intermittently by a control means (not shown) for controlling the rotation thereof. And at the time of rotation of the winding roll 3, by winding up the resin film 2 on this, the resin film 2 wound around the feeding roll 1 is sent out, pulled out from the feeding roll 1, and moved to the winding roll 3 side, When the roll is moved by a predetermined length, rotation of the take-up roll 3 is stopped, and in that state, a laminate 4 (see FIG. 5) is formed by a laminate formation means 7 described later, and then the take-up roll 3 is rotated again. The resin film 2 is moved by the predetermined length.

  Reference numerals 5 and 6 denote a pair of nip rolls arranged so as to face each other (usually at the same height position) so that the laminate forming means 7 is sandwiched between the rolls 1 and 3, and the resin film 2 is the nip roll 5 , 6 move horizontally or be held horizontally.

  7 is a laminate forming means disposed between the nip rolls 5 and 6, and is an uneven surface (mold surface) which is disposed below the resin film 2 so as to be movable up and down and has fine unevenness formed on a flat upper surface. ) A mold 8 having 8a, a dispenser 9 for applying a liquid photocurable composition 10 (see FIG. 2) on the upper surface 8a (that is, an uneven surface) of the mold 8, and the mold 8 are supported so as to be movable up and down. Lifting means (not shown) such as a cylinder, a flat support plate 11 fixed on the upper side of the resin film 2 (at a position opposite to the upper surface 8a of the mold 8), and an upper side of the support plate 11 A plurality of ultraviolet irradiation lamps 12 disposed, and a mirror 13 disposed above each ultraviolet irradiation lamp 12 are provided.

  The material of the mold 8 and the support plate 11 is not particularly limited, and examples thereof include glass, metal, ceramics, and plastic. However, the material is made of glass from the viewpoint of rigidity and translucency. preferable. In order to cure the photocurable composition by ultraviolet irradiation, at least one of the mold 8 and the support plate 11 needs to be made of a transparent material. When the support plate 11 is not a transparent material, the ultraviolet irradiation is performed. The lamp 12 and the mirror 13 may be disposed on the lower side of the mold 8 and ultraviolet irradiation may be performed from below.

  Using such a laminating apparatus, the laminate 4 can be manufactured as follows. That is, first, as shown in FIG. 2, the dispenser 9 of the laminate forming means 7 is moved along the upper surface 8a of the mold 8, and the liquid photocurable composition 10 is caused to flow out from the tip opening of the dispenser 9 to mold the mold. 8 is applied to the upper surface 8a of the substrate 8 (application step). Next, as shown in FIG. 3, the mold 8 is raised by the lifting and lowering means, and the upper surface of the photocurable composition 10 is brought into contact with the lower surface of the resin film 2, and then the mold 8 is lifted and lowered in that state. The upper surface of the resin film 2 is pressed against the flat lower surface of the support plate 11 (contact process). Next, as shown in FIG. 4, the photocurable composition 10 is irradiated with ultraviolet rays through the support plate 11 from the ultraviolet irradiation lamp 12 to cure the photocurable composition 10, and is made of the photocurable composition. The resin layer 14 is formed (resin layer forming step). Next, as shown in FIG. 5, the mold 8 is lowered by the elevating means and returned to the original position, and the resin film 2 to which the resin layer 14 is adhered is peeled from the upper surface 8 a of the mold 8 together with the resin layer 14 (peeling step). ). Through these contact process, resin layer forming process, and peeling process, a laminate 4 composed of the resin film 2 and the resin layer 14 is manufactured. On the surface of the resin layer 14 of the laminate 4, fine irregularities 14 a formed by transferring the irregularities of the upper surface 8 a of the mold 8 are formed. Moreover, the winding roll 3 is not rotating in these application | coating processes-peeling processes.

  Next, as shown in FIG. 6, the take-up roll 3 is rotated, the resin film 2 is moved to the take-up roll 3 side by a predetermined length, and the laminate 4 is sent to the outside of the laminate forming means 7. Then, a new resin film 2 is supplied to the upper side of the mold 8. Thereafter, in the same manner as described above, the coating process to the peeling process are performed to manufacture the laminate 4. Thus, the laminated body 4 is continuously manufactured by repeating the coating process to the peeling process. Moreover, the laminated body 4 wound up by the winding roll 3 is cut | disconnected by predetermined length, and becomes the laminated body 4 as shown in FIG.

  As described above, in this embodiment, the laminate 4 can be easily and efficiently manufactured continuously. In addition, the manufactured laminate 4 is excellent in appearance characteristics without coloring or deformation, has low resistance, and is excellent in photoelectric conversion efficiency.

  FIG. 8 shows another example of the laminating apparatus. In this example, both the nip rolls 5 and 6 are disposed so as to be slidable in an oblique direction. Along with this, slide means (not shown) for supporting the nip rolls 5 and 6 slidably in an oblique direction is provided. Is provided. Further, the ultraviolet irradiation lamp 12 and the mirror 13 are disposed on the lower side of the mold 8, and the support plate 11 is omitted. Other parts are the same as those in the above embodiment, and the same reference numerals are given to the same parts.

  Using such a laminating apparatus, the laminate 4 can be manufactured as follows. That is, first, as shown in FIG. 9, the coating process is performed in the same manner as in the above embodiment, and then, as shown in FIG. 10, both nip rolls 5 and 6 are slid downward toward the center by the sliding means. Thus, the lower surface of the resin film 2 is brought into contact with the upper surface of the photocurable composition 10 and brought into contact with the pressure contact state (contact process). Next, as shown in FIG. 11, the photocurable composition 10 is irradiated with ultraviolet rays from the ultraviolet irradiation lamp 12 through the mold 8 to cure the photocurable composition 10, and a resin made of the photocurable composition. The layer 14 is formed (resin layer forming step). When the mold 8 is not a transparent material, the ultraviolet irradiation lamp 12 and the mirror 13 may be disposed on the upper side of the resin film 2 and the ultraviolet irradiation may be performed from above. Next, as shown in FIG. 12, both nip rolls 5, 6 are slid upward on both sides by the sliding means to return to the original position, and the resin film 2 with the resin layer 14 attached is molded together with the resin layer 14. 8 is peeled off from the upper surface 8a of 8 (peeling step). After that, as shown in FIG. 13, the winding process is performed in the same manner as in the above embodiment.

  This embodiment also has the same effect as the above embodiment.

  Hereinafter, the resin film used by this invention and the photocurable composition which comprises a resin layer are demonstrated.

  The resin film used in the present invention is not particularly limited as long as it is transparent. However, the resin film has excellent heat resistance and adhesion with a resin layer (having fine irregularities made of a photocurable composition) described later. A film is desirable. By using a resin film having excellent transparency, sunlight can be sufficiently transmitted, and a solar cell or the like with high photoelectric conversion efficiency can be produced. Further, by using a resin film having excellent heat resistance, it is possible to form a film at a high temperature when sputtering a metal oxide, and it is possible to form a transparent electrode film having a low sheet resistance. Furthermore, it can prevent that a resin layer peels from a resin film by using the resin film excellent in adhesiveness with a resin layer.

  Examples of the resin film used in the present invention include resins such as polyethylene terephthalate, polyethylene naphthalate, polyester, polyvinyl alcohol, polycarbonate, amorphous polyolefin, polyimide, polyurethane, polymethyl methacrylate, crosslinkable acrylic monomers, and / or Or resin obtained by hardening the composition which consists of an oligomer is mentioned. Among these, polyethylene naphthalate, polyvinyl alcohol, amorphous polyolefin, polyimide, polyurethane, and cross-linked acrylic resin are preferable in terms of heat resistance, and a polyvinyl alcohol type having a large amount of hydroxyl groups in terms of adhesion to the resin layer. Resins are particularly preferred. Furthermore, the film made of polyvinyl alcohol resin may be a film subjected to uniaxial stretching or biaxial stretching, and is preferably a polyvinyl alcohol resin film subjected to biaxial stretching. In addition, the resin film used in the present invention may appropriately contain various additives such as a plasticizer in an amount of 20 parts by weight or less.

  The resin film preferably has a thickness of 10 to 500 μm, particularly 15 to 300 μm, more preferably 20 to 200 μm, from the viewpoint of handling properties and photoelectric conversion efficiency during production. If the thickness of the resin film is too thin, the film will be easily broken due to insufficient strength, and will tend to curl when the resin layer is formed, and if it is too thick, it will be difficult to wind it on a roll. is there.

  Moreover, in the said resin film, it is preferable that the heat deformation temperature is 150 degreeC or more, It is especially preferable that it is 180 degreeC or more, Furthermore, it is 200 degrees C or more. When the heat distortion temperature is too low, when the metal oxide film is formed at a high temperature, the laminate of the present invention undulates, and the metal oxide tends to crack and the sheet resistance tends to increase remarkably. The upper limit of the heat distortion temperature is usually 500 ° C.

  The resin layer having unevenness according to the present invention preferably has a thickness of 0.1 to 100 μm, particularly 0.2 to 50 μm, more preferably 0.3 to 30 μm in terms of photoelectric conversion efficiency. . If the thickness of the resin layer is too thin, the unevenness of the resin layer cannot be transferred sufficiently, and there is a tendency to reduce the photoelectric conversion efficiency in the case of a solar cell, and if it is too thick, cracking may occur when bent. There is a tendency to interfere with photoelectric conversion. In the present invention, the thickness of the resin layer having unevenness means the length from the lowest point of the resin layer to the highest point of the convex portion when the uneven surface side is placed upward. Is.

  The resin layer is obtained by photocuring using a photocurable composition. Although it does not specifically limit as this photocurable composition, It is preferable that it is a polyfunctional (meth) acrylic-type photocurable composition. By using a polyfunctional (meth) acrylic photocurable composition, a resin layer having excellent heat resistance can be obtained.

  The polyfunctional (meth) acrylic photocurable composition preferably contains a polyfunctional (meth) acrylate compound and a photopolymerization initiator, and photocures the photocurable composition. Thereby, the resin layer which consists of a photocurable composition is obtained.

  In the present invention, “(meth) acrylate” is a generic term for acrylate and methacrylate, and “(meth) acryl” is a generic term for acrylic and methacrylic.

  Examples of such polyfunctional (meth) acrylate compounds include bifunctional (meth) acrylate compounds and trifunctional or higher (meth) acrylate compounds.

Examples of the bifunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol di (meth). ) Acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin Di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol Aliphatic compounds such as glycidyl ether di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified di (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate diester, Bis (hydroxy) tricyclo [5.2.1.0 ^2.6 ] decane = di (meth) acrylate, bis (hydroxy) tricyclo [5.2.1.0 ^2.6 ] decane = acrylate methacrylate, bis (hydroxymethyl) tricyclo [ 5.2.1.0 ^2.6 ] decane = di (meth) acrylate, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane = acrylate methacrylate, bis (hydroxy) pentacyclo [6.5.1. 1 ^3.6 . 0 ^2.7 . ^09.13 ] pentadecane = di (meth) acrylate, bis (hydroxy) pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . ^09.13 ] pentadecane = acrylate methacrylate, bis (hydroxymethyl) pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . ^09.13 ] Pentadecane = di (meth) acrylate, bis (hydroxymethyl) pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . ^09.13 ] pentadecane = acrylate methacrylate, 2,2-bis [4- (β- (meth) acryloyloxyethoxy) cyclohexyl] propane, 1,3-bis ((meth) acryloyloxymethyl) cyclohexane, 1,3-bis ((Meth) acryloyloxyethyl) cyclohexane, 1,4-bis ((meth) acryloyloxymethyl) cyclohexane, 1,4-bis ((meth) acryloyloxyethyl) cyclohexane and other alicyclic compounds, diphthalate Glycidyl ester di (meth) acrylate, ethylene oxide modified bisphenol A (2,2′-diphenylpropane) type di (meth) acrylate, propylene oxide modified bisphenol A (2,2′-diphenylpropane) type di (meth) acrylate, etc. Aromatic compound And the like.

  Examples of the trifunctional or higher functional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and di Pentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, ethylene oxide modified dipentaerythritol penta (meth) Acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol Aliphatic compounds such as tri (meth) acrylate and ethylene oxide-modified pentaerythritol tetra (meth) acrylate, 1,3,5-tris ((meth) acryloyloxymethyl) cyclohexane, 1,3,5-tris ((meta And alicyclic compounds such as) (acryloyloxyethyloxymethyl) cyclohexane.

  Furthermore, in the present invention, as the polyfunctional (meth) acrylate compound, in addition to the above, polyfunctional epoxy (meth) acrylate compound, polyfunctional urethane (meth) acrylate compound, polyfunctional polyester (meth) acrylate compound Examples thereof include compounds and polyfunctional polyether (meth) acrylate compounds.

Among these polyfunctional (meth) acrylate compounds, polyfunctional urethane (meth) acrylate compounds and bis (hydroxy) tricyclo [5.2.1.] In terms of heat resistance and linear expansion coefficient of the resin film. 0 ^2.6 ] decane = di (meth) acrylate, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane = di (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) Acrylate is preferable, and further, a polyfunctional (meth) acrylate compound having an alicyclic structure is preferable in that curing shrinkage of the resin layer is suppressed and waviness is reduced, and in particular, a polyfunctional (meth) acrylate compound having an alicyclic structure is preferable. functional urethane (meth) acrylate compound or a bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6] decane Di (meth) acrylate, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6] decane = di (meth) acrylate are preferable, it is particularly preferable to use them.

  As a polyfunctional urethane (meth) acrylate-based compound suitably used in the present invention, for example, a polyisocyanate-based compound and a hydroxyl group-containing (meth) acrylate-based compound may be used, if necessary, using a catalyst such as dibutyltin dilaurate. It is preferable that it is obtained by reacting.

Specific examples of the polyisocyanate compound include aliphatic polyisocyanates such as ethylene diisocyanate and hexamethylene diisocyanate, isophorone diisocyanate, bis (isocyanatomethyl) tricyclo [5.2.1.0 ^2.6 ] decane, and norbornane isocyanate. Natomethyl, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, bis (4-isocyanatocyclohexyl) methane, 2,2-bis (4-isocyanatocyclohexyl) propane , Polyisocyanate compounds having an alicyclic structure such as hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and isophorone diisocyanate trimer compound, and diphenylmethane diisocyanate Phenylene diisocyanate, tolylene diisocyanate, and the like polyisocyanate compounds having an aromatic ring such as naphthalene diisocyanate.

  Specific examples of the hydroxyl group-containing (meth) acrylate-based compound include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3- ( Examples include meth) acryloyloxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tri (meth) acrylate, and the like.

  Two or more polyfunctional urethane (meth) acrylate compounds obtained by the reaction of a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate compound may be used in combination. Among these reactants, it is preferable to have an alicyclic skeleton from the viewpoint of water absorption, and acrylate compounds are more preferable from the viewpoint of curing speed, and 2 to 9 functional groups are particularly preferable from the viewpoint of heat resistance and bending elastic modulus. In particular, 2-6 functionalities are preferred.

  Moreover, you may add a monofunctional (meth) acrylate type compound to the said photocurable composition to such an extent that sclerosis | hardenability is not inhibited. Examples of such monofunctional (meth) acrylate compounds include ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl. Aliphatic compounds such as (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, cyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, tricyclo Decyl (meth) acrylate, tricyclodecyloxymethyl (meth) acrylate, tricyclodecyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxy Til (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl- Alicyclic compounds such as 2-adamantyl (meth) acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, aromatic compounds such as benzyl (meth) acrylate, monofunctional epoxy (meth) acrylate compounds, single Examples include functional urethane (meth) acrylate compounds, monofunctional polyester (meth) acrylate compounds, and monofunctional polyether (meth) acrylate compounds.

  These monofunctional (meth) acrylate compounds may be used alone or in combination of two or more.

  These monofunctional (meth) acrylate compounds are preferably used in a proportion of usually 50 parts by weight or less, more preferably 30 parts by weight or less, particularly 20 parts by weight with respect to 100 parts by weight of the photocurable composition. Part or less is preferred. When there is too much this usage-amount, there exists a tendency for the heat resistance of the molded object and mechanical strength which are obtained to fall.

  The photopolymerization initiator is not particularly limited as long as it can generate radicals by irradiation with active energy rays, and various photopolymerization initiators can be used. Examples include benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,6-dimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, and the like. Among these, photopolymerization initiators such as 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are particularly preferable. These photopolymerization initiators may be used alone or in combination of two or more.

  These photopolymerization initiators are (meth) acrylate compounds [when a monofunctional (meth) acrylate compound is contained, the sum of polyfunctional (meth) acrylate compounds and monofunctional (meth) acrylate compounds]] 100 weight It is preferably used at a ratio of 0.1 to 10 parts by weight with respect to parts, more preferably 0.2 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight. If the amount used is too small, the polymerization rate tends to decrease and the polymerization tends not to proceed sufficiently. If the amount is too large, the light transmittance of the resulting resin layer tends to decrease (yellowing), and the mechanical strength is low. There is a tendency to decrease.

  Moreover, you may use a thermal polymerization initiator together with a photoinitiator. As the thermal polymerization initiator, known compounds can be used, such as hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and the like. Hydroperoxides, dialkyl peroxides such as di-t-butyl peroxide and dicumyl peroxide, peroxyesters such as t-butylperoxybenzoate, t-butylperoxy (2-ethylhexanoate), benzoylper Examples thereof include peroxides such as diacyl peroxides such as oxides, peroxycarbonates such as diisopropyl peroxycarbonate, peroxyketals, and ketone peroxides.

  In addition to the (meth) acrylate compound and the photopolymerization initiator, the photocurable composition used in the present invention includes, as appropriate, an antioxidant, an ultraviolet absorber, a silane coupling agent, and a thickener. Further, auxiliary components such as an antistatic agent, a flame retardant, an antifoaming agent, a colorant, and various fillers may be contained.

  The antioxidant is useful for preventing deterioration such as color change of the substrate and decrease in mechanical strength during the high temperature process. Specific examples of such antioxidants include, for example, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 2, 6-di-t-butyl-4-s-butylphenol, 2,6-di-t-butyl-4-hydroxymethylphenol, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di- t-butylphenyl) propionate, 2,6-di-t-butyl-4- (N, N-dimethylaminomethyl) phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester 2,4-bis (n-octylthio) -6- (4-hydroxy-3 ′, 5′-di-t-butylanilino) -1,3,5-triazine, 4,4-methylene-bis (2, 6-di-t-bu Ruphenol), 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis (3,5-di-tert-butyl-4-hydroxybenzyl) Sulfide, 4,4′-di-thiobis (2,6-di-t-butylphenol), 4,4′-tri-thiobis (2,6-di-t-butylphenol), 2,2-thiodiethylenebis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydroxyhydrocinnamide, N , N′-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, calcium (3,5-di-tert-butyl-4-hydroxybenzyl) monoethyl Ruphosphonate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4 -Hydroxyphenyl) isocyanurate, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris-2 [3 (3,5-di-t-butyl-4- Hydroxyphenyl) propionyloxy] ethyl isocyanate, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] methane, 3,5-di-t-butyl-4-hydroxy Examples of the compound include benzyl phosphite-diethyl ester, and these compounds may be used alone or in combination of two or more. Among these, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4-hydroxyphenyl) propionate] methane is particularly preferable because the effect of suppressing the hue is increased.

  Further, the ultraviolet absorber is useful for preventing deterioration of solar cells and the like due to direct sunlight outdoors. Specific examples of such ultraviolet absorbers are not particularly limited as long as they are soluble in (meth) acrylate compounds, and various ultraviolet absorbers can be used. Specific examples include salicylic acid ester, benzophenone, triazole, hydroxybenzoate, and cyanoacrylate. These ultraviolet absorbers may be used in combination. Among these, in terms of compatibility with (meth) acrylate compounds, benzophenone or triazole, specifically (2-hydroxy-4-octyloxy-phenyl) -phenyl-methanone, 2-benzotriazole- Ultraviolet absorbers such as 2-yl-4-tert-octyl-phenol are preferred. The content ratio of the ultraviolet absorber is (meth) acrylate compound [when monofunctional (meth) acrylate compound is contained, the sum of polyfunctional (meth) acrylate compound and monofunctional (meth) acrylate compound]] 100 weight It is preferable that it is 0.001-1 weight part normally with respect to a part, Especially preferably, it is 0.01-0.1 weight part. If the amount of the ultraviolet absorber is too small, the light resistance of the solar cell substrate or the like tends to be lowered. If the amount is too large, the light transmittance of the resin film is lowered and the photoelectric conversion efficiency tends to be lowered.

  The photocurable composition thus obtained is photocured by irradiating with active energy rays, preferably ultraviolet rays, to obtain a resin layer.

  The present invention uses a transparent resin film and a photocurable composition as described above, and a resin layer having irregularities made of a cured product obtained by curing the photocurable composition on the surface of the transparent resin film. Are laminated to produce a laminate comprising a resin film and a resin layer having irregularities. Moreover, when manufacturing this laminated body, it is characterized by making said 5 processes (a coating process, a contact process, a resin layer formation process, a peeling process, a winding-up process) go through in this order.

  Here, as described above, it is preferable to use a polyvinyl alcohol film as the resin film because the resin film and the resin layer can maintain good adhesiveness. In addition, by photocuring the photocurable composition, there is no fear of mold loss after transfer as in the gravure printing method using a solution, and after the resin film is created, the surface is imparted with irregularities by heat and pressure. There is no concern that the transfer accuracy will be low as in the method. Further, by forming the resin layer by photocuring, not only can the resin layer be formed with extremely high accuracy, but also the process is simplified.

  Moreover, in this invention, it is necessary to have a fine unevenness | corrugation in the surface (mold surface) of the type | mold used by four processes, a coating process, a contact process, a resin layer formation process, and a peeling process, and this fine As the unevenness, the surface roughness (RMS) by AFM (atomic force microscope) measurement at a measurement range of 2 μm square and 256 measurement points is preferably 10 to 300 nm, particularly 10 to 200 nm, more preferably 15 to 100 nm is preferable. If the surface roughness (RMS) is too small, the photoelectric conversion efficiency in the case of a solar cell tends to decrease, and if it is too large, the transparent electrode tends to crack.

  The mold is not particularly limited, but is preferably made of glass or metal from the viewpoint of strength and heat resistance, and is particularly preferably made of glass from the viewpoint of translucency. Specific examples of such a mold include, for example, “A180U80”, “A110U80”, “A11DU80”, “T18VU70”, “A180U80”, “A180U80” manufactured by Asahi Glass Co., Ltd. T11VU70 ", Japanese plate glass texture glass, and the like can be mentioned, but the glass surface can be roughened by treating the glass with hydrofluoric acid or the like, or spraying powder by a sandblasting method. Among these, “A180U80” manufactured by Asahi Glass Co., Ltd., which is a commercial product, is preferable because of less variation in surface roughness between lots.

  In the peeling step, the glass plate constituting the above mold or the glass plate laminated with a metal oxide on the surface is a cured body (that is, resin) made of a photocurable composition obtained by photocuring the photocurable composition. Since the releasability of the layer) is poor, there is a possibility that the resin layer is not peeled off from the glass after photocuring and is broken. Therefore, it is desirable to apply a release agent in advance to the mold surface in contact with the resin layer. By applying a release agent, glass can be used repeatedly. The release agent is not particularly limited, but a fluorine release agent is preferable from the viewpoint of releasability. More preferable release agents include silane coupling agents containing a fluorinated alkyl group from the viewpoint of repeated durability.

  Examples of the fluorine-based mold release agent include “Optool DSX” manufactured by Daikin Industries, Ltd., “Cytop CTL-107M” manufactured by Asahi Glass Co., Ltd., “EGC-1720”, “EGC-1700”, GE manufactured by Sumitomo 3M. “XC98-B2472” manufactured by Toshiba Silicone Co., Ltd., and the like, and “OPTOOL DSX” manufactured by Daikin Industries, Ltd. is preferable in terms of releasability and repeated durability.

  In the case of using a glass plate having a metal oxide laminated on the surface as the above mold, in order to improve the adhesion between the fluorine-based silane coupling agent and the metal oxide, silicon oxide or It is desirable to form a thin film mainly composed of silicon nitride with a thickness of several nm to several tens of nm. By doing so, a chemical bond is formed between the fluorine-based silane coupling agent and the metal oxide, and a semi-permanent release film can be formed. At this time, in order to further improve the adhesion, after applying a fluorine-based silane coupling agent to the metal oxide surface, a high-temperature and high-humidity treatment (for example, under conditions of 60 ° C. and 90%) for about several hours is performed. May be.

  In the coating step, when the photocurable composition is applied to the mold surface, the viscosity at 23 ° C. is preferably 10 to 5000 mPa · s, and more preferably 20 to 2000 mPa · s. Even when the viscosity is too low or too high, it is difficult to adjust the thickness when the resin film is laminated, and the thickness accuracy tends to be inferior.

In the resin layer forming step, when ultraviolet irradiation illuminance 10~10000mW / cm ^2, particularly 100~1000mW / cm ^2, light quantity 1~100J / cm ^2, in particular is preferably carried out at 2~10J / cm ² . After irradiation, the mold can be removed, and the resulting cured product can be heated with hot air to reduce volatile gases.

  Thus, a laminate is obtained in which a resin layer having irregularities made of a cured product of the photocurable composition is formed on the surface of the transparent resin film.

  Moreover, it is preferable that the surface roughness (RMS) of the resin layer which has an unevenness | corrugation exists in the range of 10-300 nm, More preferably, it is 10-200 nm, Most preferably, it is 15-100 nm. If the surface roughness is too small, it is difficult to diffuse the incident sunlight after the metal oxide film is formed, so that the photoelectric conversion efficiency in the case of a solar cell tends to decrease. There is a tendency to crack easily. The irregular shape on the surface is preferably irregular.

  The total light transmittance of the laminate thus obtained is preferably 80% or more, particularly 85 to 95%. If the light transmittance is too low, the photoelectric conversion efficiency in the case of a solar cell tends to decrease.

  Moreover, when manufacturing the transparent electrode substrate for solar cells from the said laminated body, although this laminated body is used as a structural member of the electrode substrate for solar cells, specifically, the resin layer of the said laminated body A film made of a metal oxide or the like is formed on the substrate.

  The metal oxide is not particularly limited, but single metal oxides such as zinc oxide, tin oxide, indium oxide, and titanium oxide, and various metal oxides such as indium tin oxide, indium zinc oxide, indium titanium oxide, and tin cadmium oxide. And doping metal oxides such as gallium-doped zinc oxide, aluminum-doped zinc oxide, boron-doped zinc oxide, titanium-doped zinc oxide, titanium-doped indium oxide, zirconium-doped indium oxide, and fluorine-doped tin oxide. Among these, gallium-added zinc oxide, aluminum-added zinc oxide or boron-added zinc oxide is preferable from the viewpoints of light transmittance and low resistivity.

  A method for forming a film made of such a metal oxide is not particularly limited, but for example, it is preferable to form a film made of a metal oxide by a dry process at 150 ° C. or higher. If the temperature is too low, additives such as gallium, aluminum and boron are difficult to activate, and the crystallinity becomes poor and the sheet resistance tends to increase. The sheet resistance is preferably 50Ω / □ or less, more preferably 40Ω / □ or less, and particularly preferably 30Ω / □ or less.

  A method of forming a film made of such a metal oxide is not particularly limited, but it is preferable to form a film made of a metal oxide by a dry process at 150 ° C. or higher, for example.

  In addition, as a dry process said here, a sputtering method, CVD method, a vapor deposition method, etc. are mentioned. In the formation of the metal oxide, it is preferable to use a sputtering method from the viewpoint of adhesion with the resin layer.

  The thickness of the film made of such a metal oxide is usually 100 to 1000 nm, preferably 130 to 700 nm, particularly preferably 150 to 500 nm. If the thickness is too thin, the sheet resistance tends to be high, and if it is too thick, it takes a long time to form a film, and the light transmittance is lowered. There is.

  Further, a gas barrier film can be further formed on the laminate. The gas barrier film here is a film that blocks oxygen and moisture. Such a gas barrier film may be formed on at least one surface of the laminate. As the gas barrier film, a gas barrier film containing silicon oxide or silicon nitride as a main component is preferable. The method of film formation is not particularly limited, but a method such as vapor deposition or sputtering is preferable.

  The thickness of the gas barrier film is preferably 5 to 500 nm, more preferably 10 to 100 nm, and still more preferably 15 to 50 nm. If the film thickness is too thin, the gas barrier properties are not sufficient. Conversely, if the film thickness is too thick, cracks tend to occur when the transparent electrode substrate is bent.

The gas barrier capability is preferably a water vapor transmission rate of 1 g / day · atm · m ² or less, more preferably 0.5 g / day · atm · m ² or less, and still more preferably 0.3 g / day · atm · m ^2. m ² or less. If the water vapor transmission rate is too high, the reliability of the solar cell tends to decrease. The lower limit of the water vapor transmission rate is usually 0.001 g / day · atm · m ² .

  In the transparent electrode substrate having the layer structure of the resin film, the resin layer having unevenness, and the layer made of metal oxide, the resin film side opposite to the film made of metal oxide is further provided on the resin film. An antireflection film or an antifouling film can be formed.

  The antireflection film is preferably formed at the interface between the resin film and the atmosphere. Examples of the antireflection film include a low refractive index fluorine-based resin film and a dielectric multilayer film in which a silicon oxide film and a titanium oxide film are laminated. Among these, a fluorine-based resin film that is inexpensive and has an antifouling function is preferable. The method of film formation is not particularly limited, but a wet process such as spin coating or die coating is preferable.

  Moreover, about the transparent electrode substrate for solar cells in this invention, it is preferable that a total light transmittance is 80% or more, especially 82% or more, Furthermore, it is 84% or more. If the light transmittance is too low, the photoelectric conversion efficiency as a solar cell tends to decrease.

  The transparent electrode substrate for solar cells obtained in the present invention is excellent in appearance characteristics without coloration and deformation, has a low resistance, and has an excellent effect in photoelectric conversion efficiency. It is useful as a constituent member of an electrode substrate of a solar cell.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “parts” and “%” mean weight basis unless otherwise specified.

The measuring method of each physical property is as follows.

(1) Surface roughness (RMS) (nm)
A sample was cut to a size of 1 cm square and measured with “NanoScope III a” manufactured by Digital Instruments. The sample is set on a horizontal sample stage on the piezo scanner, the cantilever is approached to the sample surface, and when it reaches the region where the atomic force works, it scans in the XY direction, and the unevenness of the sample is displaced in the Z direction. As a laser. A scanner capable of scanning 150 μm in the XY direction and 10 μm in the Z direction was used. The cantilever having a resonance frequency of 120 to 400 kHz and a spring constant of 12 to 90 N / m was used. At the time of measurement, 256 points of 2 μm × 2 μm on the surface were measured. The scan speed was 1 Hz.

(2) Total light transmittance (%)
A 3 cm square sample was prepared, and the total light transmittance (%) was measured using a spectrophotometer (manufactured by JASCO Corporation, “V-7200”).

(3) Thermal deformation temperature (℃)
Using a test piece having a length of 30 mm and a width of 3 mm, the temperature was raised from room temperature by a tensile method TMA (distance 20 mm between fulcrums, weight 100 g, temperature increase rate 5 ° C./min) by “TMA120” manufactured by Seiko Electronics Co., Ltd. The point at which the amount of elongation was 200% (40 mm) was defined as the heat distortion temperature.

(4) Sheet resistance (Ω / □)
Using a test piece of 5 cm × 5 cm, measurement was performed using a 4-terminal resistance measuring instrument (Lorester MP) manufactured by Mitsubishi Chemical Corporation.

(5) Photoelectric conversion efficiency Current voltage measurement in a solar cell of 0.5 cm × 0.5 cm (0.25 cm ² ) under light irradiation of AM (air mass) 1.5, 100 mW / cm ² using a solar simulator. And the photoelectric conversion efficiency was determined from the measurement results of the short circuit current, open circuit voltage, and fill factor.

(6) Viscosity (mPa · s)
Using a B-type viscometer manufactured by Shibaura System Co., Ltd., “Bismetron VS-A1”, the measurement was performed at 23 ° C. and a rotational speed of 60 rpm (No. 3 rotor).

(7) Adhesiveness between resin film and resin layer (that is, adhesiveness of laminate)
A cellophane tape is applied to the surface of the resin layer, and the adhesiveness when the cellophane tape is subjected to a 180 ° peel test at a speed of 10 cm / sec is evaluated. What did not do was made into "(circle)".

<Example 1>
[Preparation of polyfunctional urethane acrylate (A-1)]
In a four-necked flask equipped with a thermometer, stirrer, water-cooled condenser and nitrogen gas inlet, 53.34 g (0.24 mol) of isophorone diisocyanate, 55.73 g (0.48 mol) of 2-hydroxypropyl acrylate, polymerization Hydroquinone methyl ether 0.02 g as an inhibitor, 0.02 g of dibutyltin dilaurate as a reaction catalyst, and 500 g of methyl ethyl ketone were charged and reacted at 60 ° C. for 3 hours. The reaction was terminated when the residual isocyanate group became 0.3%, The solvent was distilled off to obtain bifunctional urethane acrylate (A-1).

[Preparation of Photocurable Composition (B-1)]
40 parts of the above bifunctional urethane acrylate (A-1), 30 parts of bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “DCP”), pentaerythritol 30 parts of tetraacrylate (manufactured by Shin-Nakamura Chemical Co., “A-TMMT”), 1 part of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy, “Irgacure 184”) as a photopolymerization initiator, tetrakis [methylene-3 as an antioxidant -(3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] 0.5 parts of methane (Ciba Geigy, "Irganox 1010") was stirred at 60 ° C until uniform and photocured Sex composition (B-1) was obtained. The viscosity of the obtained composition was 1500 mPa · s.

[Preparation of mold (C-1)]
A silicon oxide film having a thickness of 100 mm is formed on a textured surface of glass (made by Asahi Glass Co., Ltd., “A180U80”, size 350 mm × 300 mm, surface roughness (RMS) 30 nm) having an unevenness (texture) made of tin oxide on one side. The film was formed by a sputtering method, and a fluorine-based mold release agent (manufactured by Daikin Industries, Ltd., “OPTOOL DSX”) was uniformly applied and air dried. Then, after leaving it in an environment of 60 ° C. and 90% RH for 3 hours, it was immersed in a fluorine-based solvent (“Demnam Solvent” manufactured by Daikin Industries, Ltd.) and subjected to ultrasonic cleaning at 23 ° C. for 10 minutes. 1) was obtained. The surface roughness (RMS) of this textured surface was 30 nm.

[Production of laminate]
According to the process of FIGS. 1-6, it carried out as follows.

With the texture surface of the mold (C-1) facing upward, 2 g of the photocurable composition (B-1) at 23 ° C., 2 cm inside from the edge of one side of the upper surface of the mold (C-1) The resin film (provided on both rolls of the laminating machine) was used as a resin film (polyvinyl alcohol film [Nippon Synthetic Chemical Co., Ltd. “Boblon” film (size 350 mm × 300 mm, 25 μm thickness). )]. After that, using a metal halide lamp, an ultraviolet ray was irradiated at an illuminance of 20 mW / cm ² and a light amount of 5 J / cm ² to remove the mold to obtain a laminate. The thickness of the resin layer was 10 μm, the surface roughness of the irregularities was 30 nm, and no peeling of the resin layer occurred.

  Various physical properties of the obtained laminate were as shown in Table 1 below.

[Production of transparent electrode substrate]
Next, the laminate was cut into 5 cm square, fixed to a sample holder for sputtering, and put into a sputtering machine. The inside of the sputtering machine was evacuated to a pressure of 10 ⁻⁵ Pa, and the substrate holder temperature was set to 150 ° C. Thereafter, argon gas is introduced into the sputtering machine at a flow rate of 100 sccm, adjusted to a pressure of 0.667 Pa, and then supplied with DC power of 400 W to a zinc oxide (ZnO) target to which 5.7 wt% of gallium oxide (Ga ₂ O ₃ ) has been added. did. As a result, a transparent electrode substrate in which a thin film made of gallium-doped zinc oxide having a thickness of 200 nm was formed on the textured surface of the laminate was obtained. Various physical properties of the obtained transparent electrode substrate were as shown in Table 2 below.

[Production of solar cells]
Next, the transparent electrode substrate sample was set in a three-layer separation type silicon film forming apparatus (CVD), and a photoelectric conversion layer was formed on the transparent electrode by the following procedure.

(P-type layer formation)
After transporting the sample to the p-type silicon film forming chamber, a high-purity semiconductor gas such as silane (SiH ₄ ), hydrogen (H ₂ ), diborane (B ₂ H ₆ ), methane (CH ₄ ) or the like is formed into the p-type silicon film. After introducing into the chamber at a constant flow rate and maintaining the substrate temperature at 150 ° C. and the pressure at 66.7 Pa, discharge was started, and a boron-doped a-Si alloy film having a thickness of 10 nm was obtained by film formation for 1 minute. Thereafter, only the introduction of diborane (B ₂ H ₆ ) gas under the above conditions was stopped in the same chamber, and a 5 nm thick film was formed using a non-doped a-SiC alloy film as a solar cell buffer layer. After film formation was completed, the vacuum was exhausted again.

(I-type layer formation)
Next, after the sample was transported to the i-type silicon film forming chamber, SiH ₄ and H ₂ were introduced into the i-type silicon film forming chamber at a constant flow rate and maintained at a substrate temperature of 150 ° C. and a pressure of 133 Pa, and then discharge was started. A non-doped a-Si having a thickness of 0.35 μm was obtained by film formation for 25 minutes. After film formation was completed, the vacuum was exhausted again to high vacuum.

(N-type layer formation)
Next, the sample is transported to the n-type silicon film forming chamber, SiH ₄ , H ₂ and phosphine (PH ₃ ) are introduced into the n-type silicon film forming chamber at a constant flow rate, and the substrate temperature is maintained at 150 ° C. and the pressure is 26.7 Pa. It was. Discharge was started and phosphorus-doped a-Si having a thickness of 30 nm was obtained by film formation for 6 minutes. After film formation was completed, the vacuum was exhausted again.

(Backside reflective electrode layer formation)
After forming the above p-i-n3 layer photoelectric conversion unit, after cooling the sample to room temperature and taking it out into the atmosphere, the sample is placed in the sputtering vacuum apparatus again, and the backside reflective electrode layer is formed by the following procedure. did.

A gallium-added zinc oxide layer 20 nm, a silver layer 200 nm, and a gallium-added zinc oxide layer 20 nm were laminated in this order at room temperature. After removing the sample from the vacuum device, a solar cell having an area of 0.25 cm ² was obtained by patterning the back electrode. Thereafter, post-annealing at 150 ° C. was performed for 2 hours.

  It was 8% when the photoelectric conversion efficiency of the amorphous silicon solar cell obtained by the above process was measured.

<Example 2>
[Preparation of polyfunctional urethane acrylate (A-1)]
The same bifunctional urethane acrylate (A-1) as in Example 1 was used.

[Preparation of Photocurable Composition (B-1)]
The same photocurable composition (B-1) as Example 1 was used.

[Preparation of mold (C-2)]
A silicon oxide film having a thickness of 100 mm is formed on a textured surface of glass (made by Asahi Glass Co., Ltd., “T18VU70”, size 350 mm × 300 mm, surface roughness (RMS) 25 nm) having an unevenness (texture) made of tin oxide on one side. The film was formed by a sputtering method, and a fluorine-based mold release agent (manufactured by Daikin Industries, Ltd., “OPTOOL DSX”) was uniformly applied and air dried. Then, after leaving it in an environment of 60 ° C. and 90% RH for 3 hours, it was immersed in a fluorine-based solvent (“Demnam Solvent” manufactured by Daikin Industries, Ltd.) and subjected to ultrasonic cleaning at 23 ° C. for 10 minutes. 2) was obtained. The surface roughness (RMS) of this textured surface was 25 nm.

[Production of laminate]
Except having used said (C-2) as a type | mold, it carried out similarly to Example 1 and obtained the laminated body. Various physical properties of the obtained laminate were as shown in Table 1 below.

[Production of transparent electrode substrate]
A transparent electrode substrate was produced in the same manner as in Example 1. Various physical properties of the obtained transparent electrode substrate were as shown in Table 2 below.

[Production of solar cells]
A solar battery cell was produced in the same manner as in Example 1. The photoelectric conversion efficiency of the obtained solar cell was as shown in Table 2 below.

<Example 3>
[Preparation of polyfunctional urethane acrylate (A-2)]
In a four-necked flask equipped with a thermometer, stirrer, water-cooled condenser, and nitrogen gas inlet, 53.34 g (0.24 mol) of isophorone diisocyanate, pentaerythritol triacrylate (hydroxyl value 125.4 mg KOH / g) (Osaka Organic) Chemical Industry Co., Ltd., “Biscoat # 300”) 95.46 g (0.48 mol), 0.02 g of hydroquinone methyl ether as a polymerization inhibitor, 0.02 g of dibutyltin dilaurate as a reaction catalyst, and 500 g of methyl ethyl ketone, 60 The reaction was carried out at 3 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.3%, and the solvent was distilled off to obtain a hexafunctional urethane acrylate (A-2).

[Preparation of Photocurable Composition (B-2)]
40 parts of the above-mentioned hexafunctional urethane acrylate (A-2), 40 parts of bis (hydroxymethyl) tricyclo [5.2.1.02,6] decane = dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “DCP”), tri A photocurable composition (B-2) was obtained in the same manner as in Example 1 except that 20 parts of cyclodecyl acrylate ("FA-513A" manufactured by Hitachi Chemical Co., Ltd.) was used. The viscosity of the obtained photocurable composition (B-2) was 500 mPa · s.

[Preparation of mold (C)]
The same mold (C-1) as in Example 1 was used.

[Production of laminate]
It carried out similarly to Example 1 and obtained the laminated body. Various physical properties of the obtained laminate were as shown in Table 1 below.

[Production of transparent electrode substrate]
A transparent electrode substrate was produced in the same manner as in Example 1. Various physical properties of the obtained transparent electrode substrate were as shown in Table 2 below.

[Production of solar cells]
A solar battery cell was produced in the same manner as in Example 1. The photoelectric conversion efficiency of the obtained solar cell was as shown in Table 2 below.

  The measurement results of the examples are shown in Tables 1 and 2 below.

It is description which shows the lamination apparatus used for the manufacturing method of the laminated body of this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus in this invention. It is sectional drawing which shows the laminated body of this invention. It is explanatory drawing which shows the other example of the lamination apparatus in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus of the other example in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus of the other example in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus of the other example in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus of the other example in this invention. It is explanatory drawing which shows the effect | action of the lamination apparatus of the other example in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding roll 2 Resin film 3 Winding roll 8 Type | mold 8a Surface

Claims (7)

A method for producing a laminate, comprising the following five steps when producing a laminate in which a resin layer having fine irregularities made of a photocurable composition is formed on the surface of a resin film.
1. A coating process in which a liquid photocurable composition is coated on the mold surface of a mold having fine irregularities on the surface.
2. The contact process which makes the surface of the resin film sent out predetermined length from one roll face and contact the surface of the said apply | coated photocurable composition.
3. A resin layer forming step of forming a resin layer made of the photocurable composition by curing the photocurable composition by light irradiation after the contact step.
4). The peeling process which peels the resin film to which the said resin layer adhered after the said resin layer formation process from the surface of a type | mold.
5. A winding step of performing the movement of the resin film and the winding of winding the laminate of the resin film and the resin layer around the other roll after the peeling step.   The method for producing a laminate according to claim 1, wherein the resin film has a thickness in the range of 10 to 500 μm.   The manufacturing method of the laminated body of Claim 1 or 2 whose surface roughness (RMS) of the said resin layer exists in the range of 10-300 nm.   The total light transmittance of the said laminated body is 80% or more, The manufacturing method of the laminated body as described in any one of Claims 1-3.   The said photocurable composition contains a polyfunctional (meth) acrylate and a photoinitiator, The manufacturing method of the laminated body as described in any one of Claims 1-4.   The laminated body obtained by the manufacturing method as described in any one of Claims 1-5.   The laminated body of Claim 6 used as a structural member of the electrode substrate for solar cells.

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