JP2016186042A - Adhesive sheet and organic electronic device prepared with the adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive sheet that is excellent in the properties described in the Specifications, and provide an organic electronic device having a beautiful appearance and sufficient peeling strength.SOLUTION: An adhesive sheet comprises an isobutylene elastomer, where one surface and the other surface are different in tack. There is also provided an organic electronic device comprising the adhesive sheet as an encapsulation layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adhesive sheet, a method for producing the adhesive sheet, an organic electronic device using the adhesive sheet as a sealing material, and a method for producing the organic electronic device.

  An ethylene-vinyl acetate copolymer or the like is known as a sealing material for silicon-based solar cells. However, since the ethylene-vinyl acetate copolymer has a high water vapor transmission rate and a large amount of water vapor penetrates from the end portion, when used in an organic electronic device, the performance of the organic electronic device tends to deteriorate.

  Accordingly, various sealing materials have been developed for sealing organic electronic elements. For example, an adhesive composition of a polyisobutylene resin and a tackifier resin is known (Patent Documents 1 and 2).

JP 2007-197517 A JP 2012-193335 A

  The pressure-sensitive adhesive compositions described in Patent Documents 1 and 2 have high gas barrier properties, adhesiveness, and transparency, and are good for devices when used as a sealing material when an organic electronic device is sealed with a protective layer or a gas barrier layer. It can bring durability.

On the other hand, since the tackiness is high, for example, when laminating with an organic electronic element by a vacuum laminating process, there is a problem that rework (reattachment) cannot be performed, and bubbles are caught in the laminating. That is, until now, there has been no sealing material that satisfies gas barrier properties, adhesiveness, transparency, and processability (reworkable).
An object of the present invention is to provide an adhesive sheet excellent in these characteristics, and to provide an organic electronic device having a beautiful appearance and sufficient peel strength.

As a result of intensive studies to solve the above problems, the present inventors have developed a sealing material having different tacks on the front and back surfaces of the sealing material, thereby solving the above problems and achieving the present invention. It came.
That is, the gist of the present invention is as follows.

[1] An adhesive sheet containing an isobutylene elastomer, wherein the tackiness of one surface and the other surface is different.
[2] The adhesive sheet according to [1], comprising at least one type of tackifying resin.
[3] The adhesive sheet according to [2], wherein the composition ratio of the isobutylene elastomer and the tackifying resin is different between one surface and the other surface of the adhesive sheet.
[4] Any one of [1] to [3], wherein the adhesive sheet is an adhesive sheet composed of two or more layers, and has a layer made of a composition containing an isobutylene elastomer on at least one surface. The adhesive sheet according to 1.
[5] The method for producing an adhesive sheet according to any one of [1] to [4], wherein the adhesive sheet coating liquid is applied onto a substrate and then dried.
[6] The method for producing an adhesive sheet according to any one of [1] to [4], wherein two or more adhesive sheets are bonded.
[7] A laminate in which the adhesive sheet according to [1] to [4] and a barrier film are laminated.
[8] An organic electronic device having a first barrier layer, a first sealing layer, an organic electronic element, a second sealing layer, and a second barrier layer in order, the first sealing layer and the second sealing layer At least one consists of the adhesive sheet as described in [1]-[4], The organic electronic device characterized by the above-mentioned.

  According to the present invention, an adhesive sheet satisfying gas barrier properties, adhesive properties, transparency, and processability (reworkable) can be provided. Moreover, by using the adhesive sheet of the present invention as a sealing material, it is possible to provide an organic electronic device having a beautiful appearance and sufficient peel strength.

It is a schematic diagram of the organic thin-film solar cell module as one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

1. Adhesive sheet In the present invention, adhesion is defined as “a state in which two surfaces are bonded by an adhesive as a medium by chemical or physical force or both”, and the adhesive sheet is laminated with another layer. If an adhesive sheet and this other layer adhere | attach, it will not be restrict | limited.

  In this invention, it is preferable that it is a base-material destruction in the peeling strength measurement (JISK6854) of an adhesive sheet and another layer. In the case of interfacial fracture and cohesive fracture, the peel strength is usually 3 N / inch or more, preferably 5 N / inch or more, and more preferably 10 N / inch or more. The upper limit of the peel strength is usually 1000 N / inch or less, preferably 800 N / inch or less, and more preferably 500 N / inch or less.

It is preferable at the point which can suppress peeling from a device edge part at the time of conveyance, construction, and use by being more than the said minimum. By being below the above upper limit, it is preferable in that the element and the protective layer can be peeled off during disposal and recovery.
1.1 Component The adhesive sheet of the present invention contains an isobutylene elastomer and, if necessary, an additive and a tackifying resin.

1.1.1 Isobutylene Elastomer The isobutylene elastomer is not limited as long as it is a polymer having a structural unit derived from isobutylene in the main chain skeleton. For example, polyisobutylene, isobutylene-isoprene copolymer, isobutylene-styrene copolymer, isobutylene-styrene hydrogenated copolymer and the like can be mentioned, and polyisobutylene is preferable in terms of high transparency and low water vapor permeability.

The weight average molecular weight is usually 10,000 or more, preferably 100,000 or more, more preferably 500,000 or more, and usually 2000000 or less, preferably 1500,000 or less, more preferably 1,000,000 or less. When it is at least the lower limit, creep resistance is improved, and when it is at most the upper limit, favorable adhesive strength can be obtained.
1.1.2 Additive

  The adhesive sheet may contain an ultraviolet absorber, an antioxidant, a silane coupling agent, and a softening agent as additives.

  The ultraviolet absorber can be used without any particular limitation. Examples include benzophenone compounds, benzotriazole compounds, triazine compounds, and the like. When an ultraviolet absorber is added to the sealing layer, the amount is preferably 0.01% by weight or more, more preferably 0.05% by weight or more based on the total amount of the sealing layer. On the other hand, the content is preferably 1% by weight or less, more preferably 0.8% by weight or less, and particularly preferably 0.6% by weight or less. This is because if it is less than 0.01% by weight, it is difficult to exhibit the ultraviolet absorption effect, and if it exceeds 1% by weight, it causes bleeding out.

  The tackifiers and the like described below are often compounds (polymers) containing double bonds, and compounds (polymers) containing double bonds tend to be oxidatively deteriorated chemically. It is effective to add. The antioxidant is not particularly limited as long as it is usually used in the field of adhesives, resin materials or rubber materials. Specifically, phenolic antioxidants, phosphite antioxidants and amine-based antioxidants are used. An antioxidant is mentioned. From the viewpoint of influence on organic electronic devices, phenolic antioxidants and amine-based antioxidants are preferred, but phenolic antioxidants are particularly preferred.

  By including the silane coupling agent, the adhesiveness of the adhesive sheet is improved. Preferred examples of the silane coupling agent include those having an alkyl group as a functional group, and specific examples include an epoxy group, a methacryl group, and a vinyl group. The content of the silane coupling agent is preferably 0.1 to 2.0, more preferably 0.3 to 1.0, and 0.5 to 0 when the weight of the resin is 100. .7 is particularly preferred. By setting it as such a range, adhesiveness can be made suitable. The phrase “containing a silane coupling agent” herein means adding or mixing the silane coupling agent to the encapsulant, and the silane coupling agent is added to or mixed with the encapsulant in advance before the solar cell module is stacked. It may be added, or may be added to or mixed with the sealing material during lamination.

  A softening agent may be added to the adhesive sheet. Known softeners may be used and are not particularly limited. For example, aromatic hydrocarbons, paraffinic hydrocarbons, naphthenic hydrocarbons, low molecular weight polybutenes, low molecular weight polyisobutylenes, low molecular weight polyisoprenes, Examples include various depolymerized rubbers (liquid rubbers), mineral oils (process oils), liquid rubbers such as hydrogenated liquid polyisoprene and derivatives thereof, petrolactam, petroleum asphalts, and the like. These softeners may be used alone or in combination of two or more.

1.1.3 Tackifier An adhesive force, tack, and holding force of the adhesive sheet can be controlled by adding a tackifier resin to the adhesive sheet of the present invention. Examples of the tackifier resin include rosin resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, aliphatic / aromatic hybrid petroleum resins, and alicyclic petroleum resins. Examples of rosin resins include gum rosin, wood rosin, tall oil rosin, rosin-modified maleic resin, polymerized rosin, rosin phenol, rosin ester, and hydrogenated rosin.

  Specific examples of the terpene resin include terpene resins, terpene phenol resins, aromatic modified terpene resins, and hydrogenated terpene resins. The terpene resin is obtained by polymerizing any one of α-pinene, β-pinene and dipentene (limonene), or copolymerizing a mixture. The terpene phenol resin is a copolymer of terpene and phenol, and examples thereof include α-pinenephenol resin, dipentenephenol resin, and terpene bisgenol resin. The aromatic modified terpene resin is obtained by copolymerizing a terpene monomer and an aromatic monomer. The hydrogenated terpene resin is obtained by hydrogenating a terpene resin, a terpene phenol resin, or an aromatic modified terpene resin.

  Examples of the aliphatic petroleum resin include those obtained by polymerizing a C5 petroleum resin such as piperylene, isoprene, 2-methylbutene-2, dicyclopentadiene alone, or copolymerizing a mixture.

  Examples of the aromatic petroleum resins include coumarone resins, inden resins, hydrogenated coumarone resins, hydrogenated inden resins, phenol resins, styrene resins, hydrogenated styrene resins, and xylene resins. The coumarone resin is obtained by copolymerizing coumarone and any one of styrene, vinyltoluene, and α-methylstyrene, or by copolymerizing a mixture. The indene resin is obtained by copolymerizing indene and any of styrene, vinyltoluene, and α-methylstyrene, or by copolymerizing a mixture. Hydrogenated coumarone resin is a hydrogenated coumarone resin. Hydrogenated indene resin is a hydrogenated indene resin. The phenol resin is a copolymer of phenols and aldehydes. Examples of the styrene resin include acrylonitrile butadiene styrene copolymer, acrylonitrile styrene copolymer, and styrene thermoplastic elastomer. The styrenic thermoplastic elastomer has a polystyrene block and a rubber intermediate block, and examples of the intermediate rubber block include polybutadiene, a polyethylene / butylene copolymer, an ethylene / propylene copolymer, and a vinyl / polyisoprene copolymer. Hydrogenated styrene resin is a hydrogenated styrene resin. The xylene-based resin is a copolymer of m-xylene and formaldehyde.

  Examples of the aliphatic / aromatic hybrid petroleum resin include an aliphatic / aromatic hybrid petroleum resin and a hydrogenated aliphatic / aromatic hybrid petroleum resin. The mixed aliphatic / aromatic petroleum resin is a copolymer of isoprene, piperylene, 2-methylbutene, -1 and 2, styrene, vinyltoluene, α-methylstyrene, indene, dicyclopentadiene or a mixture thereof. Hydrogenated aliphatic / aromatic hybrid petroleum resin is a hydrogenated aliphatic / aromatic hybrid petroleum resin.

  Examples of the alicyclic petroleum resin include dicyclopentadiene resin and hydrogenated dicyclopentadiene resin. The dicyclopentadiene resin is obtained by copolymerizing dicyclopentadiene and any one of styrene, butadiene, pentadiene, vinyl acetate, maleic anhydride, and phenol, or a mixture thereof. Hydrogenated dicyclopentadiene resin is obtained by hydrogenating dicyclopentadiene resin.

1.2 Thickness The thickness of the adhesive sheet is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 20 μm or more. On the other hand, it is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less.

  When the thickness of the adhesive sheet is equal to or more than the lower limit, the adhesive follows the steps of the current collector and the base film, and a device having good appearance without bubbles can be created. In addition, the withstand voltage characteristics are improved, which is preferable in terms of safety. Furthermore, since the peel adhesive strength is improved, the peeling failure of the device can be suppressed.

  Moreover, by being below an upper limit, the combustible part of an organic electronic device can be reduced and a flame retardance improves. Moreover, since moisture intrusion from the end portion can be suppressed, module durability is improved. Moreover, light absorption by the adhesive sheet is suppressed, and the solar cell characteristics are improved. Moreover, the weight of the adhesive sheet per unit area can be suppressed, and the manufacturing cost of the adhesive sheet can be reduced, and the workability of the device and the efficiency of transportation can be expected. Furthermore, since the shear bond strength is improved, creep rupture can be suppressed.

1.3 Physical Properties The water vapor transmission rate of the adhesive sheet under the conditions of 40 ° C. and 90% RH is that the water vapor transmission rate per unit area (1 m ² ) per day is usually 100 g / m ² / day or less in terms of thickness of 50 μm, Preferably it is 50 g / m ² / day or less, more preferably 20 g / m ² / day or less, and particularly preferably 10 g / m ² / day or less, and there is no limit on the lower limit. By being below the upper limit, the penetration of moisture into the solar cell module can be suppressed, and the durability of the module can be improved. The method for measuring the water vapor transmission rate is, for example, according to JIS Z0208.

  From the viewpoint of supplying a large amount of sunlight to the solar cell element, the total light transmittance of the adhesive sheet is usually 80% or more, preferably 85% or more. The upper limit is not particularly limited, but is usually 99% or less. The measuring method of a total light transmittance is based on JISK7361-1, for example.

  The haze of the adhesive sheet is usually 50% or less, preferably 30% or less, more preferably 10% or less, and particularly preferably 5% or less. Although a minimum is not specifically limited, Usually, it is 0.1% or more. By being below the upper limit, it is possible to obtain a module having no appearance and good appearance. The method for measuring haze is, for example, according to JIS K 7136.

1.4 Tack The adhesive sheet of the present invention is characterized in that the tack on one side and the other side is different. That tack is different means that the range of the upper limit and the lower limit of the value measured three times by the following measurement method does not overlap.

<Tack measurement method>
Measure under the following conditions, and take the peak value of the force when pulling apart as the tack value.
Each sample was measured three times.
Apparatus: Brookfield, CT3-4500
Probe material: Acrylic φ12.7 (Model number: TA10)
Approach speed: 2.0mm / min
Applied pressure: 200g
Pressurization time: 3 seconds Pulling speed: 2.0 mm / min
Temperature: 23 ° C

The adhesive sheet of the present invention has different tackiness on one side and the other side.
The tack of the surface having low tackiness is preferably 500 gf or less, more preferably 300 gf or less, and even more preferably 100 gf or less, as the average of the values measured three times by the above measuring method. Although there is no restriction | limiting in a lower limit, Usually, it is 0 gf or more, 1 gf or more is preferable and 2 gf or more is more preferable. When the tack value of the surface having low tack property is not more than the above upper limit, rework (re-sticking) when laminating with other layers is easy, and it is possible to suppress the entrapment of bubbles at the time of laminating. Appearance module can be obtained. By being above the above lower limit, each layer does not slip during lamination, and positioning is easy.

  Moreover, the tack value of the surface having high tackiness is usually 500 gf or more, preferably 700 gf or more, and more preferably 900 gf or more. There is no limit on the upper limit. When the tack value is 500 gf or more, reliable adhesion to the surface protective layer and the back surface protective layer becomes possible.

<Relative value of tack>
The ratio of tackiness between one surface and the other surface is usually 1.5 times or more, preferably 2 times or more, and more preferably 3 times or more. On the other hand, it is usually 2000 times or less, preferably 1500 times or less, and more preferably 1000 times or less.

  By being above the above lower limit, the tackiness of the low tack surface is low, so that rework is possible and bubbles during lamination can be suppressed. Moreover, since the tack property of the high tack surface is high, good adhesion to the protective layer can be obtained. By being below the above upper limit, the tackiness of the low tack surface is a little, so that it is possible to suppress the deviation of the base material up to the laminate after layup. Moreover, since the tack of a high tack surface is lower than an upper limit, workability | operativity can be ensured when bonding the adhesive sheet to a protective layer.

<Tack control method>
The tack greatly depends on the elastic modulus of the adhesive sheet. Basically, when the elastic modulus of the adhesive sheet is low, the tackiness is increased because the adhesive sheet is easily wetted. In particular, it is known that the elastic modulus of rubber-based pressure-sensitive adhesive can be controlled by the composition ratio of the elastomer and the tackifier.

Therefore, if you want to increase the tack at room temperature, adjust the amount of elastomer and tackifier to lower the elastic modulus at room temperature, add low molecular weight elastomer, add plasticizer such as process oil, low It can be controlled by a method such as selecting a tackifier having a softening point. If you want to lower the tack at room temperature, adjust the amount of elastomer and tackifier to increase the modulus at room temperature, add high molecular weight elastomer, increase the amount of high softening point tackifier It can control by the method of etc. If specifically at 1 × 10 ⁸ Pa or more in modulus, almost tack without, 1 × 10 ⁷ ~1 × began to tack expressed in a range of 10 ⁸ Pa, the tack at 1 × 10 ⁶ Pa or less High value.

1.5 Structure The adhesive sheet of the present invention may be a single layer or a laminate of two or more layers. Hereinafter, the adhesive sheet having each structure will be described.

1.5.1 One layer It is preferable that the composition ratio of an elastomer and a tackifier is different on one surface and the other surface of a one-layer adhesive sheet. Specifically, the composition of the surface having a high tack is 40% by weight or more, preferably 45% by weight or more, more preferably 50% by weight or more, and the composition of the surface having a low tack is 40% by weight or less. , Preferably 35% by weight or less, more preferably 30% by weight or less.

  Examples of the method for measuring the composition of the adhesive sheet surface include the FT-IR ATR method. Specifically, after measuring the ATR spectrum of each component present in the mixed composition, the ATR spectrum of the mixed composition is measured, and the height or area of each peak is compared, so that the surface of the mixed composition is measured. It is possible to determine the ratio of each component present.

  As a method for producing such an adhesive sheet, there is a method utilizing the solubility of components contained in the sheet in a solvent. In a production method in which each composition is dissolved in a solvent to prepare a coating solution for an adhesive sheet, and then a film is formed and dried to obtain a sheet, components having lower solubility tend to precipitate on the sheet surface. On the other hand, a component with high solubility is biased toward the coated substrate. By utilizing this mechanism and changing the composition of the surface, it is possible to create an adhesive sheet having different tackiness on one side and the other side. In addition, by using multiple types of solvents, changing the drying conditions and controlling the evaporation rate, the composition of the coating substrate surface and the drying surface can be given a gradient, and the film thickness can be controlled to control the front and back surfaces. Sheets with different properties can be created.

  Further, the tack on the side where the residual solvent remains can be raised by drying only one side so that the residual solvent remains on one side.

  The solid content concentration of the adhesive sheet coating solution is usually 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight, still more preferably 15% by weight or more, and usually 99.99% by weight or less. Preferably it is 80 weight% or less, More preferably, it is 50 weight% or less. When the solid content concentration is at least the above lower limit, the coating speed can be increased, which is preferable in terms of productivity. Moreover, it can suppress that a coating viscosity becomes low too much, can prevent the dripping at the time of application | coating, etc., and is preferable at the surface of coating film quality. Further, when the solid content concentration is not more than the above upper limit, even when a high molecular weight elastomer is used, it is possible to suppress the viscosity from becoming too high and to suppress the generation of bubbles at the time of application.

  The content of the isobutylene elastomer in the solid content of the coating solution for adhesive sealing film is usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, and further preferably 40% by weight or more. It is 90% by weight or less, preferably 80% by weight or less, more preferably 70% by weight or less. When the isobutylene elastomer content in the solid content is not less than the above lower limit, it is preferable from the viewpoint of improving adhesiveness and moisture barrier properties. Moreover, when content of the isobutylene-type elastomer in solid content is below the said upper limit, it is preferable from a viewpoint of adhesive improvement. Here, the solid content of the adhesive sheet coating liquid is obtained by removing the solvent from the adhesive sheet coating liquid.

  The tackifying resin content in the solid content of the adhesive sheet coating solution is usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, and usually 90% by weight or less, preferably 80% by weight or less. More preferably, it is 70 weight% or less, More preferably, it is 60 weight% or less. When the content of tackifying resin in the solid content is not more than the above upper limit, it is preferable from the viewpoint of improving adhesiveness and moisture barrier properties. Moreover, when tackifying resin content in solid content is more than the said minimum, it is preferable from a viewpoint of adhesive improvement.

  The mixing weight ratio (isobutylene elastomer / tackifying resin) of the isobutylene elastomer and tackifying resin contained in the coating liquid for the adhesive sheet is usually 10/90 or more, preferably 20/80 or more, more preferably 30/70 or more. More preferably, it is 40/60 or more, usually 90/10 or less, preferably 80/20 or less, more preferably 70/30 or less. When the mixing weight ratio of the isobutylene elastomer and the tackifying resin is not less than the above lower limit, it is preferable from the viewpoint of improving adhesiveness and moisture barrier properties. Moreover, it is preferable from a viewpoint of adhesiveness improvement when the mixing weight ratio of an isobutylene-type elastomer and tackifying resin is below the said upper limit.

  The total content of polyisobutylene and tackifying resin in the solid content of the coating liquid for adhesive sheet is usually 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, and further preferably 95% by weight or more. is there. When the total content of polyisobutylene and tackifying resin in the solid content is not less than the above lower limit, it is preferable from the viewpoint of improving adhesiveness and moisture barrier properties.

  When the softening agent is contained in the adhesive sheet coating solution, the content of the softening agent in the solid content of the adhesive sheet coating solution is usually 0.01% by weight or more, preferably 1% by weight or more, more preferably 5% by weight. Above, it is usually 30% by weight or less, preferably 20% by weight or less, more preferably 10% by weight or less. When content of the softening agent in solid content is more than the said minimum, it is preferable from a viewpoint of the adhesive improvement by initial stage adhesion (tack). When it is below the above upper limit, creep resistance is improved, which is preferable in terms of application to a device used for a long time.

<Manufacturing method>
The adhesive sheet of the present invention can be produced by a melt extrusion method, but preferably, the above-mentioned adhesive sheet coating solution of the present invention is applied onto a substrate and dried according to the method for producing an adhesive sheet of the present invention. Manufactured by.

  Examples of the method for applying the adhesive sheet coating liquid of the present invention to the substrate include spray coating, dip coating, doctor blade coating, curtain roll coating, gravure roll coating, reverse roll coating, air knife coating, and the like. Method, rod coating method, die coating method, offset printing method, comma coating method and the like.

  The relative humidity during application of the adhesive sheet coating solution is usually 20% or more, preferably 25% or more, more preferably 30% or more, and usually 85% or less, preferably 80% or less, more preferably 75% or less. is there. When the relative humidity is within the above range, since the uniformity of the adhesive sheet is improved, the decrease in adhesion and moisture barrier properties due to the decrease in film uniformity may be suppressed, which is preferable.

  There is no restriction | limiting in the atmosphere at the time of application | coating of the coating liquid for adhesive sheets. For example, the coating liquid for the adhesive sheet may be applied in an air atmosphere, and may be applied in an inert gas atmosphere such as argon.

  It is preferable to perform filtration in order to remove foreign matter from the coating liquid for the adhesive sheet. As a filtration method, a known method can be used. For example, a known method such as a filter paper, a nonwoven fabric, a metal mesh, a sintered metal, a porous plate, a porous ceramic, or a filter can be used. Although there is no limitation in particular as a mesh of a filter medium, Usually, the thing of about 5-20 micrometers is used suitably. Filtration is usually performed at room temperature under normal pressure or reduced pressure.

  Although there is no restriction | limiting in the temperature of the coating liquid for adhesive sheets, Usually 0 degreeC or more, Preferably it is 10 degreeC or more, More preferably, it is 20 degreeC or more, Usually, 200 degrees C or less, Preferably it is 150 degrees C or less, More preferably, it is 100 degrees C or less, More preferably, it is 80 degrees C or less. When the temperature at the time of application is within the above range, the film thickness unevenness of the adhesive sheet due to volatilization of the solvent is suppressed, and there is a possibility that the decrease in adhesiveness and moisture barrier property due to the decrease in film uniformity may be suppressed. ,preferable.

  When the adhesive sheet coating liquid is solvent-free, since the adhesive sheet is obtained by cooling the coating liquid after application, drying after application is not required, but when the adhesive sheet coating liquid contains a solvent, After coating, drying for solvent removal is performed.

  As the drying method, a known method can be used, and examples thereof include a natural drying method, a heat drying method (hot air drying method, infrared drying method, far infrared drying method, etc.). You may implement and may implement in combination of 2 or more type.

  In the case of the heat drying method, the heating temperature is usually 40 ° C. or higher, preferably 60 ° C. or higher, more preferably 80 ° C. or higher, more preferably 100 ° C. or higher, usually 300 ° C. or lower, preferably 200 ° C. or lower, more preferably 150. It is below ℃. When heating temperature is more than the said minimum, the residual solvent in an adhesive sheet can be reduced and it is preferable. When heating temperature is below the said upper limit, deterioration by the heating of an adhesive sheet can be suppressed, and it is preferable. Moreover, since the base material which can be used is not restrict | limited to a heat resistant base material, it is preferable.

  The heating time during drying is usually 1 second or longer, preferably 10 seconds or longer, more preferably 30 seconds or longer, more preferably 1 minute or longer, particularly preferably 5 minutes or longer, usually 24 hours or shorter, preferably 12 hours or shorter, More preferably, it is 6 hours or less, More preferably, it is 4 hours or less. When heating time is more than the said minimum, the residual solvent in an adhesive sheet can be reduced and it is preferable. When the drying time is not more than the above upper limit, it is possible to prevent thermal deterioration of the substrate and the substrate, and it is also preferable from the viewpoint of productivity.

  Since the residual solvent tends to lower the adhesive force and moisture barrier property, the content of the residual solvent is usually 0 pm or more, preferably 1 ppm or more, more preferably 2 ppm or more, and usually 20000 ppm or less, more preferably 2000 ppm or less. More preferably, it is 1000 ppm or less, and particularly preferably 500 ppm or less. A residual solvent can be calculated | required by conversion of the chloroform solution of the applied solvent using a gas chromatography (GC) method.

  The atmosphere during drying includes an air atmosphere, a nitrogen gas atmosphere, an Ar gas atmosphere, a He gas atmosphere, a carbon dioxide atmosphere, and the like. The coating film after heat drying may be cooled or cooled.

  As a base material to which the adhesive sheet coating solution is applied, various resin films, paper, glass plates, and the like can be used. As the resin material of the resin film, a thermoplastic resin or a thermosetting resin can be used, and there is no particular limitation. Examples of the thermoplastic resin include polyolefin resins, polystyrene resins, vinyl chloride resins, acrylic resins, polyester resins, fluorine resins, polycarbonate resins, nylon resins, and cellulose acetate. Examples of the thermosetting resin include polyester resin, acrylic resin, epoxy resin, phenol resin, unsaturated alkyd resin, melamine resin, and urethane resin. The resin film used in the present invention can be produced by a known method, and examples thereof include extrusion, calendering, injection, hollow, and compression molding.

  A release agent may be applied to the application surface of the substrate. As the release agent, a known one such as a silicone resin can be used. Moreover, you may use the below-mentioned barrier film as a base material.

  The adhesive sheet formed by applying an adhesive sheet coating solution on a substrate and drying it as necessary may be covered with another substrate and sandwiched between two substrates. At this time, the materials of the two substrates may be the same or different. Moreover, the thickness of two base materials may be the same and may differ. From the viewpoint of peeling the adhesive sheet from the base material, the thicknesses of the two base materials are preferably different.

1.5.2 Laminate of two or more layers The adhesive sheet of the present invention may be a laminate of two or more layers.
For example, what laminated | stacked 2 or more layers of the adhesive sheet from which the composition ratio of an isobutylene-type elastomer and a tackifier differs is mentioned. In the laminate of two or more layers, the composition ratio of the elastomer and the tackifier is preferably different between one surface layer and the other surface layer. Specifically, the composition of one surface layer is 40% by weight or more of elastomer, preferably 45% by weight or more, more preferably 50% by weight or more, and the composition of the other surface layer is 40% by weight or less of elastomer. , Preferably 35% by weight or less, more preferably 30% by weight or less.

The resin constituting the layer not containing the isobutylene elastomer may be a two-layer structure including a layer containing the isobutylene elastomer and a layer not containing the isobutylene elastomer. For example, olefin resin, polyester resin, polyamide resin, polyurethane resin, ethylene- Vinyl acetate copolymers and the like can be mentioned, and among them, olefin resins and polyester resins are preferable because of their low water vapor permeability.
Moreover, the laminated body of 3 or more layers which combined said resin may be sufficient.

  The thickness of the adhesive sheet as a laminate of two or more layers is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 20 μm or more. On the other hand, it is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less.

  When the thickness of the adhesive sheet is equal to or more than the above lower limit, the adhesive follows the steps of the current collector and the base film, and an electronic device having a good appearance without bubbles can be created. In addition, the withstand voltage characteristics are improved, which is preferable in terms of safety. Furthermore, since the peel adhesive strength is improved, the peeling failure of the device can be suppressed.

  Moreover, when it is below the said upper limit, when it uses as a sealing material of an electronic device, the combustible part of an electronic device can be reduced and a flame retardance improves. Moreover, since moisture intrusion from the end portion of the electronic device can be suppressed, module durability is improved. Further, light absorption by the adhesive sheet is suppressed, and the characteristics of the electronic device are improved. Moreover, the weight of the adhesive sheet per unit area can be suppressed, and the manufacturing cost of the adhesive sheet can be reduced, and the workability and transportation efficiency of the electronic device can be expected. Furthermore, since the shear bond strength of the adhesive sheet is improved, creep failure of the electronic device can be suppressed.

  The thickness of each layer of the laminate is usually 1.5 times or more, preferably 2 times or more, more preferably 3 times or more the thickness of the layer containing the most elastomer. preferable. The upper limit is not limited. By being in the said range, favorable adhesiveness can be obtained, suppressing the bubble generation at the time of lamination.

<Manufacturing method>
By creating multiple sheets with different tackiness and pasting them together. Adhesive sheets with different front and back tackiness can be created.
Although the manufacturing method of a laminated body will not have a restriction | limiting in particular if the effect of this invention is not impaired, For example, the method of bonding after producing each layer previously is mentioned. For example, wet lamination, dry lamination, hot melt lamination, extrusion lamination, coextrusion lamination, lamination with a photo-curing adhesive, thermal lamination, vacuum lamination and the like can be mentioned. Among them, a thermal laminate that does not require an adhesive between two adhesive sheets is preferable because a transparent film can be easily obtained.

The heating temperature in the laminating step is usually 10 ° C or higher, preferably 20 ° C or higher, and is usually 180 ° C or lower, preferably 170 ° C or lower. It is preferable at the point from which the adhesive strength of a laminated body is acquired by being more than a minimum. Moreover, it is preferable because it is less than the upper limit because decomposition, deformation, and the like of the adhesive sheet can be suppressed.
Further, as a production method other than the above, there is a method in which the other layer is formed on one layer by solvent coating or extrusion molding.

2. Organic Electronic Device Since the adhesive sheet of the present invention has high gas barrier properties and adhesiveness, it can be suitably used as a sealing material for organic electronic devices that are vulnerable to water and oxygen.
Examples of the organic electronic device include a switching element, a photoelectric conversion device, an optical sensor, and the like using an organic semiconductor. The adhesive sheet of the present invention has high transparency, and thus can be suitably used for an organic photoelectric conversion device. Examples of the organic photoelectric conversion device include an organic electroluminescence device and an organic solar cell. Especially, since the adhesive sheet of this invention is excellent in processability, it can be used conveniently for the organic thin film electronic device which can be manufactured by roll-to-roll.

Hereinafter, an organic thin film solar cell will be described as an example of a preferred embodiment of an organic electronic device.
FIG. 1 shows an organic thin film solar cell module 1 in which an organic thin film solar cell element 13 and a collector wire 14 electrically connected to the organic thin film solar cell element 13 are sandwiched by a front surface protective layer 11 and a back surface protective layer 12. It is a schematic diagram.
In FIG. 1, the organic thin film solar cell element 13 and the collector line 14 are sandwiched between the surface protective layer 11 and the back surface protective layer 12 via the sealing layer 15, and the sealing layer 15 is connected to the organic thin film solar cell element 13. It may be only between the surface protective layer 11 or only between the organic thin film solar cell element 13 and the back surface protective layer 12. The adhesive sheet is used as a material for the sealing layer 15.

The thickness of the organic thin film solar cell module 1 is usually 0.2 mm or more, preferably 0.5 mm or more, more preferably 1 mm or more, and usually 4 mm or less, preferably 3.5 mm or less, more preferably 3 mm or less. . It is preferable at the point from which the mechanical strength of a module is acquired by being more than the said minimum. By being below the upper limit, the module can be reduced in weight, and flexibility is obtained.
Hereinafter, each structure of the organic thin film solar cell module will be described in detail.

2-1. Surface protective layer 11
The surface protective layer of the organic thin film solar cell module has a total light transmittance of usually 80% or more, preferably 85% or more, from the viewpoint of supplying a large amount of sunlight to the organic thin film solar cell element. The upper limit is not particularly limited, but is usually 99% or less. The measuring method of a total light transmittance is based on JISK7361-1, for example.

  The haze of the surface protective layer is usually 50% or less, preferably 30% or less, more preferably 10% or less, and particularly preferably 5% or less. Although a minimum is not specifically limited, Usually, it is 0.1% or more. By being below the upper limit, it is possible to obtain a module having no appearance and good appearance. Haze measurement method is, for example, according to JIS K 7136

  Materials for the surface protective layer include glass, acrylic resin such as polycarbonate (PC) and polymethyl methacrylate (PMMA), polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and ethylene-tetrafluoroethylene copolymer. (ETFE), fluorine-based resins such as polytetrafluoroethylene (PTFE), polystyrene, cyclic polyolefin, polybutylene, polypropylene (PP), polyolefin such as polyethylene (PE), and the like. Preferably, glass, polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and fluorine resins such as ethylene-tetrafluoroethylene copolymer (ETFE) and polytetrafluoroethylene (PTFE) are used.

  The thickness of the surface protective layer is usually 0.02 mm or more. Preferably it is 0.03 mm or more, More preferably, it is 0.05 mm or more. On the other hand, the upper limit is not particularly limited, but is usually 2 mm or less, preferably 1 mm or less, more preferably 0.5 mm or less, and still more preferably 0.3 mm or less. By setting it as the above range, both impact resistance and light weight can be achieved.

  Moreover, in the solar cell module of this invention, you may provide a surface protection sheet in the outer side (sunlight side) of a surface protection layer. In the present invention, it is preferable to provide a surface protective sheet in order to suppress damage and deterioration of the surface protective layer and maintain the total light transmittance. The material constituting the surface protective sheet is preferably a weather-resistant film, a hard coat film, or the like, and commonly used known materials can be used.

Examples of the resin that is a material for the weather resistant film include ethylene-tetrafluoroethylene copolymer, silicone, polyethylene terephthalate, polyamide, polyvinyl chloride, and the like. Among these, ethylene-tetrafluoroethylene copolymer and polyvinyl chloride are preferable.
The thickness of the weather-resistant film is not particularly limited, but is usually 10 μm or more, preferably 20 μm or more, and usually 200 μm or less, preferably 150 μm or less.

  An adhesive layer may be provided between the surface protective sheet and the surface protective layer. The material of the adhesive layer is not particularly limited, but usually, for example, ethylene-vinyl acetate copolymer (EVA) resin, polyvinyl butyral (PVB) resin, modified polyethylene resin modified with maleic acid or silane, modified polypropylene resin, A light transmissive material such as an epoxy adhesive or a urethane adhesive is used. The thickness of the adhesive layer is not particularly limited, but is preferably 20 to 500 μm, for example. The adhesive layer can also be used for adhesion of layers other than the surface protective sheet. The surface protective layer preferably has a gas barrier property. By covering the organic thin-film solar cell element with a surface protective layer having a gas barrier property, the solar cell element can be protected from water and oxygen, and the power generation capacity can be kept high.

The degree of moisture-proof ability of the surface protective layer having gas barrier properties varies depending on the type of the organic thin-film solar cell element, etc., but the water vapor per day at 40 ° C., 90% RH condition, unit area (1 m ² ). The transmittance is usually preferably 1 × 10 ⁻¹ g / m ² / day or less, and the lower limit is not limited.

The degree of oxygen permeability varies depending on the type of the organic thin film solar cell element, etc., but the oxygen permeability per unit area (1 m ² ) is usually 1 × 10 ⁻¹ cc / m ² / day. / Atm or less is preferred, and there is no limit to the lower limit.

  The specific structure of the surface protective layer having gas barrier properties is arbitrary as long as the organic thin film solar cell element can be protected from water. However, since the production cost increases as the amount of water vapor or oxygen that can permeate the surface protective layer increases, it is preferable to use an appropriate film that comprehensively considers these points.

  Examples of the surface protective layer suitable in terms of gas barrier properties include a film obtained by vacuum-depositing silicon oxide (SiOx) on a base film such as glass, polyethylene terephthalate (PET), or polyethylene naphthalate (PEN).

  The surface protective layer having gas barrier properties may be formed of one type of material or may be formed of two or more types of materials. The surface protective layer having gas barrier properties may be formed of a single layer film, but may be a laminated film including two or more layers.

2-2. Back surface protective layer 12
As the back surface protective layer, the same layer as the surface protective layer can be used. However, since the back surface protective layer does not necessarily have translucency, the translucency and material are not limited thereto.

For example, a resin other than the resin exemplified for the surface protective layer, a metal foil, a film in which fibers or the like are dispersed in the resin, or a woven or non-woven fabric impregnated with resin can be used.
As resins other than those exemplified for the surface protective layer, polyvinyl chloride, polyacetal, polyamide resin, ABS resin, ACS resin, AES resin, ASA resin, copolymers thereof, PVDF, silicone resin, cellulose, nitrile resin, Examples of the resin include phenol resin, polyurethane, ionomer, polybutadiene, polybutylene, polymethylpentene, polyvinyl alcohol, polyarylate, polyetheretherketone, polyetherketone, and polyethersulfone.

Examples of the metal foil include aluminum, stainless steel, gold, silver, copper, titanium, nickel, iron, and foils made of alloys thereof.
Examples of the resin of the resin in which fibers and the like are dispersed and the woven or non-woven fabric impregnated with the resin include resins used for the surface protective layer. Examples of the fiber include polyester fiber, polypropylene fiber, glass fiber, nylon fiber, cellulose fiber, carbon fiber, and / or acrylic fiber. As the woven or non-woven fabric, a woven or non-woven fabric made of these fibers is used. Can be mentioned.

The use of a light-transmitting layer similar to the surface protective layer as the back surface protective layer is preferable in that a see-through solar cell can be provided when the organic thin film solar cell has a light transmitting property.
Moreover, it is preferable that a surface protective layer and a back surface protective layer are the same material and thickness. Heat shrinkage and thermal expansion due to heating in the manufacturing process and sunlight when using the organic thin film solar cell module, etc., but canceling the stress generated at that time, suppressing the deformation of the organic thin film solar cell module it can.

2-3. Organic thin film solar cell element 13
An organic thin film solar cell element is comprised from the organic thin film solar cell which converts sunlight into electricity, and the solar cell base material for suppressing the shape change of an organic thin film solar cell.
The organic thin film solar cell element is an element that generates power by receiving light. The type of the organic thin-film solar cell element is not particularly limited as long as it can convert light energy into electric energy and can extract the electric energy obtained by the conversion to the outside. The organic thin-film solar cell element is preferable in that the module can be reduced in weight, the module fixing is less restricted, and the installation location is diversified.

  As an organic thin film solar cell element, a power generation layer (photoelectric conversion layer, light absorption layer) is sandwiched between a pair of electrodes, and a laminate of a power generation layer and another layer (buffer layer, etc.) is sandwiched between a pair of electrodes A plurality of such devices connected in series can be used. Examples of the material used for the power generation layer include organic pigment materials and organic semiconductor materials. By using these materials, a thin (light) solar cell with relatively high power generation efficiency can be realized. Further, from the viewpoint of increasing efficiency, a HIT type or a tandem type in which these are laminated may be used.

An organic semiconductor layer (a layer including a p-type semiconductor and an n-type semiconductor) can also be employed as the power generation layer. The organic semiconductor layer is preferable in that it can be formed efficiently, and because the power generation layer has various colors, it is excellent in design.
For the above reasons, an organic thin-film solar cell element that employs an organic semiconductor layer as a power generation layer is preferred.

  Specific examples of the structure of the organic semiconductor layer include a bulk heterojunction type having a layer (i layer) in which a p-type semiconductor and an n-type semiconductor are phase-separated in the layer, a layer containing a p-type semiconductor (p layer), and n, respectively. A layered type (hetero pn junction type), a PIN type, a Schottky type, and a combination thereof in which layers (n layers) including a type semiconductor are stacked can be given. Among these, a bulk heterojunction type is preferable.

  A p-type semiconductor compound is a material that operates as a p-type semiconductor whose film can transport holes, but a π-conjugated polymer material or a π-conjugated low-molecular organic compound is preferably used. A mixture of these compounds may also be used. The conjugated polymer material is obtained by polymerizing a single or a plurality of π-conjugated monomers, and the monomers include thiophene, fluorene, carbazole, diphenylthiophene, dithienothiophene, dithienosilole, dithieno which may have a substituent. Examples thereof include cyclohexane, benzothiadiazole, thienothiophene, imidothiophene, benzodithiophene, and the like. These monomers may be directly bonded or may be bonded via CH═CH, C≡C, N, or O. Low molecular organic semiconductor materials include condensed aromatic hydrocarbons such as pentacene and naphthacene, oligothiophenes having four or more thiophene rings, porphyrin compounds, tetrabenzoporphyrin compounds and their metal complexes, phthalocyanine compounds and their metal complexes, etc. .

The n-type semiconductor compound is not particularly limited, and examples thereof include fullerene compounds and derivatives thereof, and condensed ring tetracarboxylic acid diimides. Examples of fullerenes include C60 or C70, and those obtained by adding a substituent to two carbons of the fullerene, those having a substituent added to four carbons, and further adding a substituent to six carbons. Things. In order for the fullerene compound to be applicable to a coating method, the fullerene compound is preferably highly soluble in some solvent and can be applied as a solution.
When an organic semiconductor layer is used for the power generation layer, it is preferable to stack a hole extraction layer and / or an electron extraction layer.

  The material of the hole extraction layer is a conductive polymer in which polythiophene, polypyrrole, or polyaniline is doped with sulfonic acid and / or halogen, or a metal oxide having a large work function such as molybdenum oxide or nickel oxide. Used.

  Although the material of an electron extraction layer is not specifically limited, Specifically, an inorganic compound or an organic compound is mentioned. Examples of the inorganic compound include alkali metal salts such as LiF, and n-type oxide semiconductors such as titanium oxide (TiOx) and zinc oxide (ZnO). Examples of the organic compound include phenanthrene derivatives such as bathocuproine (BCP) and bathophenanthrene (Bphen), and phosphine compounds having a P═O or P═S structure. Among them, an aromatic hydrocarbon group or an aromatic group is included in the phosphorus atom. A heterocyclic group phosphine compound is preferred.

  Each electrode of the organic thin-film solar cell can be formed using one or more arbitrary materials having conductivity. Examples of the electrode material (electrode constituent material) include metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, and alloys thereof; indium oxide and tin oxide Metal oxides such as, or alloys thereof (ITO: indium tin oxide); conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene; acids such as hydrochloric acid, sulfuric acid, sulfonic acid, Containing dopants such as Lewis acids such as FeCl3, halogen atoms such as iodine, metal atoms such as sodium and potassium; conductive particles such as metal particles, carbon black, fullerene and carbon nanotubes in a matrix such as a polymer binder Examples thereof include a dispersed conductive composite material.

  The electrode material is preferably a material suitable for collecting holes or electrons. Examples of the electrode material suitable for collecting holes (that is, a material having a high work function) include gold and ITO. Examples of the electrode material suitable for collecting electrons (that is, a material having a low work function) include silver and aluminum.

  Each electrode of the organic thin film solar cell may be substantially the same size as the power generation layer or may be smaller than the power generation layer. However, if the electrode on the light-receiving surface side (weatherproof layer side) of the organic thin-film solar cell is relatively large (the area is not sufficiently small compared to the power generation layer area), The electrode should be a transparent (translucent) electrode, particularly an electrode having a relatively high transmittance (for example, 50% or more) of light having a wavelength at which the power generation layer can efficiently convert the electric energy. is there. Examples of transparent electrode materials include oxides such as ITO and IZO (indium oxide-zinc oxide); metal thin films, and the like.

  The thickness of each electrode of the organic thin film solar cell and the thickness of the power generation layer can be determined based on the required output and the like. Further, an auxiliary electrode may be provided so as to be in contact with the electrode. In particular, it is effective when using a slightly conductive electrode such as ITO. As the auxiliary electrode material, the same material as the above metal material can be used as long as the conductivity is good, but silver, aluminum, and copper are exemplified.

  The said solar cell base material is a member by which an organic thin film solar cell is formed on the one surface. Therefore, it is desirable that the solar cell base material has a relatively high mechanical strength, is excellent in weather resistance, heat resistance, chemical resistance, and the like and is lightweight. It is also desirable that the solar cell substrate has a certain degree of resistance to deformation. Therefore, it is preferable to employ a metal foil, a resin film having a melting point of 85 to 350 ° C., or a laminate of several metal foils / resin films as the solar cell base material. A resin base material is more preferable.

Examples of the metal foil that can be used as a solar cell substrate (or a component thereof) include foils made of aluminum, stainless steel, gold, silver, copper, titanium, nickel, iron, and alloys thereof.
The resin film having a melting point of 85 to 350 ° C includes polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polycarbonate, polyacetal, acrylic resin, polyamide resin, ABS resin, ACS resin. , AES resin, ASA resin, copolymers thereof, fluorine resin such as PVDF, PVF, silicone resin, cellulose, nitrile resin, phenol resin, polyurethane, ionomer, polybutadiene, polybutylene, polymethylpentene, polyvinyl alcohol, polyarylate, Examples thereof include films made of polyetheretherketone, polyetherketone, polyethersulfone and the like. In addition, the resin film used as a solar cell base material may be a film in which glass fibers, organic fibers, carbon fibers and the like are dispersed in the resin as described above.

  In addition, when melting | fusing point of the resin film used as a solar cell base material (or its component) is the range of 85-350 degreeC, a deformation | transformation of a solar cell base material does not arise but peeling with an organic thin film solar cell. This is preferable because it does not occur. Further, the melting point of the resin film used as the solar cell substrate (or a component thereof) is more preferably 100 ° C. or higher, further preferably 120 ° C. or higher, and particularly preferably 150 ° C. or higher. Preferably, it is 180 ° C. or higher. The melting point of the resin film is more preferably 300 ° C. or less, further preferably 280 ° C. or less, and particularly preferably 250 ° C. or less.

2-4. Current collector 14
In the present invention, the current collector is a conductive member electrically connected to the electrode of the organic thin film solar cell element. Examples of the material for the current collecting wire include metals and alloys. Among them, copper, aluminum, silver, gold, nickel and the like having low resistivity are preferably used, and copper and aluminum are particularly preferable because they are inexpensive. In order to prevent rust, the current collector may be plated with tin, silver or the like, the surface may be coated with resin, or a film may be laminated. As the shape of the current collecting wire, there are a rectangular wire, foil, flat plate, and wire shape, but for reasons such as securing a bonding area, it is preferable to use a flat wire, foil, or flat plate shape. Moreover, since a current collection line can be used as an electrical extraction terminal, it is more preferable that it is flat form.

  In the present invention, the “foil” refers to one having a thickness of less than 100 μm, and the “plate” refers to one having a thickness of 100 μm or more. Further, the “flat wire” refers to a wire whose cross section is rolled to make the cross section into a quadrangle.

  The current collector is not particularly limited as long as it has conductivity, but preferably has a lower resistance value than the upper electrode and lower electrode to be connected, and in particular, by increasing the thickness of the upper electrode and lower electrode, It is preferable to reduce the resistance value. The thickness of the current collector is preferably 5 μm or more, more preferably 10 μm or more. Moreover, it is preferable that it is 2 mm or less, More preferably, it is 1 mm or less, More preferably, it is 500 micrometers or less, Most preferably, it is 300 micrometers or less. When the thickness of the current collection line is equal to or more than the above lower limit, an increase in the resistance value of the current collection line can be suppressed, and the generated power can be efficiently taken out to the outside. Moreover, when it is less than the upper limit, problems such as unevenness on the surface of the organic thin-film solar cell module being likely to occur and production cost increasing may occur.

  Moreover, the width | variety of a current collection line is 0.5 mm or more in general, Preferably it is 1 mm or more, More preferably, it is 2 mm or more, and is 50 mm or less normally, Preferably it is 20 mm or less, More preferably, it is 10 mm or less. By making the width | variety of a current collection line more than the said minimum, the raise of the resistance value of a current collection line can be suppressed and the generated electric power can be taken out efficiently. Moreover, the mechanical strength of the current collector can be maintained, and breakage and the like can be suppressed. By being below the upper limit, the aperture ratio of the entire module can be maintained, and a decrease in the amount of power generated by the module can be suppressed.

2-5. Sealing layer 15
The said adhesive sheet can be used as a sealing layer of the organic thin film solar cell module of this invention. At least one sealing layer is provided between the solar cell element and the back surface protective layer and / or between the solar cell and the surface protective layer.

  It is more preferable to have at least one sealing layer between the surface protective layer and the organic thin film solar cell element and between the organic thin film solar cell element and the back surface protective layer. By providing such a sealing layer, the above-described solar cell element can be sealed, and impact resistance and the like can be imparted to the solar cell module.

In the organic thin film solar cell module of this invention, the aspect by which a sealing layer is laminated | stacked so that a solar cell element may be pinched | interposed is preferable.
The water vapor transmission rate at 40 ° C. and 90% RH of the sealing layer is usually 100 g / m ² / day or less, preferably 50 g in terms of the water vapor transmission rate per unit area (1 m ² ) per 50 μm thickness. / M ² / day or less, more preferably 20 g / m ² / day or less, particularly preferably 10 g / m ² / day or less, and the lower limit is not limited. By being below the above upper limit, it is possible to suppress the intrusion of moisture into the solar cell module and improve the durability of the module. The method for measuring the water vapor transmission rate is, for example, according to JIS Z0208.

The sealing layer generally has a total light transmittance of 80% or more, preferably 85% or more, from the viewpoint of supplying a large amount of sunlight to the organic thin film solar cell element. The upper limit is not particularly limited, but is usually 99% or less. The measuring method of a total light transmittance is based on JISK7361-1, for example.
The haze of the sealing layer is usually 50% or less, preferably 30% or less, more preferably 10% or less, and particularly preferably 5% or less. Although a minimum is not specifically limited, Usually, it is 0.1% or more. By being below the upper limit, it is possible to obtain a module having no appearance and good appearance. The method for measuring haze is, for example, according to JIS K 7136.

  The adhesive sheet is used as the material for the sealing layer. In addition to the sealing layer using the adhesive sheet, it may further include a layer containing a resin material having a relatively high total light transmittance. For example, polyisobutylene, isobutylene-isoprene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, propylene-ethylene-α -Polyolefin resin such as olefin copolymer, butyral resin, styrene resin, epoxy resin, (meth) acrylic resin, urethane resin, silicone resin, synthetic rubber, etc. can be used, and a mixture of one or more of these, Alternatively, a copolymer can be used. Among these, polyisobutylene, isobutylene-isoprene copolymer, polyolefin resin, and epoxy resin are particularly preferable because of low water vapor permeability.

The thickness of the sealing layer is preferably 10 μm or more per layer, more preferably 20 μm or more, and further preferably 30 μm or more. On the other hand, it is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less. That is, in the case of having at least one sealing layer between the surface protective layer and the organic thin film solar cell element, and between the organic thin film solar cell element and the back surface protective layer, which is a preferred embodiment, an organic thin film solar cell module The thickness of the surrounding sealing layer is preferably 20 μm or more, more preferably 40 μm or more, and further preferably 60 μm or more. On the other hand, it is preferably 2000 μm or less, more preferably 1600 μm or less, and still more preferably 1000 μm or less.
By setting the thickness of the sealing layer in the above range, moderate impact resistance can be obtained, and it is also preferable from the viewpoint of withstand voltage characteristics, durability, cost, and weight, and sufficiently exhibits power generation characteristics. Can do.

  An ultraviolet absorber may be added to the sealing layer of the solar cell module. Such ultraviolet absorbers can be used without particular limitation including those commercially available. Examples include benzophenone compounds, benzotriazole compounds, triazine compounds, and the like. When an ultraviolet absorber is added to the sealing layer, the amount is preferably 0.01% by weight or more, more preferably 0.05% by weight or more based on the total amount of the sealing layer. On the other hand, the content is preferably 1% by weight or less, more preferably 0.8% by weight or less, and particularly preferably 0.6% by weight or less. This is because if it is less than 0.01% by weight, it is difficult to exhibit the ultraviolet absorption effect, and if it exceeds 1% by weight, it causes bleeding out.

  Moreover, it is preferable that the said sealing layer contains a silane coupling agent. By including the silane coupling agent, the adhesion between the sealing layer and the layer in contact with the sealing layer is improved. Preferred examples of the silane coupling agent include those having an alkyl group as a functional group, and specific examples include an epoxy group, a methacryl group, and a vinyl group. The weight ratio of the sealing material to the silane coupling agent is preferably 0.1 to 2.0, more preferably 0.3 to 1.0, when the weight of the sealing material is 100. 0.5 to 0.7 is particularly preferable. By setting it as such a range, adhesiveness can be made suitable. The phrase “containing a silane coupling agent” herein means adding or mixing the silane coupling agent to the encapsulant, and the silane coupling agent is added to or mixed with the encapsulant in advance before the solar cell module is stacked. It may be added, or may be added to or mixed with the sealing material during lamination.

2-6. Other layers In addition to the above, layers such as an ultraviolet cut layer, a gas barrier layer, and a getter material layer may be provided between the surface protective layer and the back surface protective layer. A known material can be used as a material for forming these layers, and the size and thickness are not limited as long as the effects of the present invention are exhibited.

  In particular, by covering the organic thin-film solar cell element with a gas barrier layer, it can be protected from water and / or oxygen, and the power generation capacity can be kept high.

The degree of moisture barrier capability of the gas barrier layer varies depending on the type of organic thin film solar cell element, etc., but the water vapor transmission rate per unit area (1 m ² ) per day is usually 40 ° C. and 90% RH. It is preferably 1 × 10 ⁻¹ g / m ² / day or less, and the lower limit is not limited.

The degree of oxygen permeability varies depending on the type of the organic thin film solar cell element, etc., but the oxygen permeability per unit area (1 m ² ) is usually 1 × 10 ⁻¹ cc / m ² / day. / Atm or less is preferred, and there is no limit to the lower limit.

  The specific configuration of the gas barrier layer is arbitrary as long as the organic thin-film solar cell element can be protected from water. However, since the production cost increases as the amount of water vapor or oxygen that can permeate the surface protective layer increases, it is preferable to use an appropriate film that comprehensively considers these points.

  Examples of the gas barrier layer include a film obtained by vacuum-depositing silicon oxide (SiOx) on a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

  The surface protective layer having gas barrier properties may be formed of one type of material or may be formed of two or more types of materials. The gas barrier film 3 may be formed of a single layer film, but may be a laminated film including two or more layers.

2-7. Manufacturing method of organic thin film solar cell module Hereinafter, the manufacturing method of the organic thin film solar cell module according to the present invention will be described. However, the manufacturing method of the organic thin film solar cell module according to the present invention is not limited to the following, and As long as the organic thin-film solar cell module according to the invention can be manufactured, it may be manufactured in any way.

  First, an electrical connection between the organic thin film solar cell element and the collector line is performed. The method of electrical connection is not limited, and a thermosetting resin composition containing conductive particles, a thermoplastic plastic containing conductive particles, solder, a metal paste, or the like can be used. A thermosetting resin composition containing conductive particles, a thermoplastic composition containing conductive particles, and a metal paste are preferable in that the organic thin film solar cell element can be easily prevented from being deformed or deteriorated. Among these, a thermosetting resin composition containing conductive particles that hardly cause poor appearance and a thermoplastic composition containing conductive particles are preferable.

  In addition, the electrical connection between the organic thin film solar cell element and the collector line may be after the laminating step. There are roughly two methods for electrically connecting the organic thin film solar cell element and the collector line after the laminating step. One is a method of not laminating the collector connection portion. The other is a method of laminating the collector connection portion and taking it out later. Examples of the former include a method in which holes are previously formed in a sealing layer, a surface protective layer, and the like, and a method in which only the power generation unit is laminated. Examples of the latter include a method of forming holes in the sealing layer and the surface protective layer after lamination, a method of breaking through the sealing layer and the surface protective layer using a metal such as caulking, and the like. Whichever method is used, it is possible to protect the connection portion by laminating the electrical connection portion or the entire module after electrically connecting the organic thin film solar cell and the collector wire.

Next, a surface protective layer, a sealing layer, a solar cell element, a sealing layer, and a back surface protective layer are laminated in this order.
The following is mentioned as a method of laminating these.
(1) A method of laminating a sealing layer on each of a surface protective layer and a back surface protective layer, and then laminating a solar cell element. (2) A method of first laminating a sealing layer on a solar cell element and then laminating a front surface protective layer and a back surface protective layer. (3) A method of laminating a surface protective layer, a sealing layer, a solar cell element, a sealing layer, and a back surface protective layer together.

  Among these, especially when the thickness of the sealing layer is thin, the adhesive force is high, or the cohesive force of the sealing material is small, if the release film is peeled off on both sides at the same time, breakage, wrinkles, etc. occur. It is difficult to make the sealing layer stand alone. In that case, the above-mentioned methods (1) and (2) are preferable, and it is considered from the viewpoint of minimizing the process of passing solar cell elements that are easily damaged mechanically and chemically as compared with the surface protective layer and the back surface protective layer. Of these, the method (1) is most preferable.

  The method of laminating each is not particularly limited, but examples include a method of bonding using roll lamination, vacuum lamination, etc., a method of forming a sealing layer on each layer by solvent coating, extrusion molding, and the like. It is done. Among them, a method of laminating using a roll laminate or a vacuum laminate that requires less time for heat and less damage to each layer is preferable.

  In addition, as a particularly preferable method, after the high tack surface of the sealing material is bonded in advance to the surface protective layer and the back surface protective layer by roll lamination, the low tack surface of the sealing material is applied to the solar cell element side by vacuum lamination. The method of pasting is mentioned. By this method, it is possible to obtain a solar cell module that ensures adhesion between the surface protective layer and the sealing layer and the back surface protective layer and the sealing layer during roll lamination, has no bubbles during vacuum lamination, and has good step tracking. .

  As conditions for laminating the sealing material on the surface protective layer and the back surface protective layer by roll lamination, the roll temperature is usually 10 ° C or higher, preferably 20 ° C or higher, and usually 180 ° C or lower, preferably 170 ° C or lower. is there. It is preferable at the point from which the adhesive strength of a laminated body is acquired by being more than a minimum. Moreover, it is preferable because it is less than the upper limit because decomposition, deformation, and the like of the adhesive sheet can be suppressed.

  Moreover, the conveyance speed at the time of lamination | stacking is 0.1 m / min or more normally, Preferably it is 0.5 m / min, More preferably, it is 1.0 m / min or more. Moreover, it is 1000 m / min or less normally, Preferably it is 800 m / min or more, More preferably, it is 500 m / min or less. By being above the lower limit, productivity is ensured and film deformation due to excessive application of heat is suppressed, and by being below the upper limit, fluttering of the film during transportation is suppressed, and a laminate without bubbles and wrinkles is created. I can do it.

  Then, after laminating so that the surface protective layer, sealing layer, solar cell element, sealing layer, and back surface protection are arranged in this order, they are placed in a vacuum lamination device, and after vacuuming, they are integrated by heating and pressing. Thus, an organic solar cell module can be obtained. At this time, since a solar cell element and a sealing member can be dehydrated simultaneously by using a vacuum lamination apparatus, a module having no bubbles and excellent durability can be obtained. Moreover, it is preferable because a module having a beautiful step following can be obtained by pressing with a diaphragm rubber.

  In the vacuuming, the degree of vacuum is usually 30 Pa or more, preferably 50 Pa or more, more preferably 80 Pa or more. On the other hand, the upper limit is usually 150 Pa or less, preferably 120 Pa or less, more preferably 100 Pa or less. By setting it as the said range, since generation | occurrence | production of a bubble can be suppressed in each layer in a module and productivity is also improved, it is preferable.

  The vacuum time is usually 1 minute or longer, preferably 2 minutes or longer, more preferably 3 minutes or longer. On the other hand, the upper limit is usually 120 minutes or less, preferably 90 minutes or less, more preferably 60 minutes or less. By setting the vacuum time within the above range, it is preferable because generation of bubbles can be suppressed in each layer in the module while ensuring productivity.

  The heating temperature is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 110 ° C. or higher. On the other hand, the upper limit is usually 180 ° C. or lower, preferably 160 ° C. or lower, more preferably 150 ° C. or lower. By setting the temperature range, sufficient adhesive strength can be obtained.

  As for the pressurizing condition, the pressure is usually 50 kPa or more, preferably 70 kPa or more, more preferably 90 kPa or more. On the other hand, the upper limit value is preferably 101 kPa or less. By setting it as the pressurization conditions of the said range, since moderate adhesiveness can be acquired, without damaging a solar cell module, it is preferable also from a durable viewpoint.

  The holding time of the pressure is usually 1 minute or longer, preferably 3 minutes or longer, more preferably 5 minutes or longer. On the other hand, the upper limit is usually 60 minutes or less, preferably 45 minutes or less, more preferably 30 minutes or less. By setting it as the said holding time, it can follow the level | step difference of a collector wire, a base material, etc., can fully exhibit the function which protects the solar cell of a sealing layer, and can acquire sufficient adhesive strength.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to a following example.
Example 1

<Creation of adhesive sheet>
Polyisobutylene (Opanol B80, manufactured by BASF) 3.86 g, aliphatic hydrocarbon resin (Quinton A100, manufactured by Nippon Zeon) 2.08 g, antioxidant 594 mg (Irganox 1010, manufactured by BASF) in toluene 34 g at room temperature with a mixed rotor ( VMR-3 (manufactured by ASONE) was used to prepare an adhesive sealing film coating solution A.

  The adhesive sheet coating liquid A was applied onto a peeled PET film (MRV50, thickness 50 μm, manufactured by Mitsubishi Plastics) using an applicator, heated and dried on a hot plate at 80 ° C. for 5 minutes, and then heated at 110 ° C. using a hot air oven. After heat drying for 30 minutes, a peeled PET film (MRF50, thickness 50 μm, manufactured by Mitsubishi Plastics) was bonded to create an adhesive sheet A (film thickness 40 μm).

Next, an adhesive sheet B (film thickness 20 μm) was prepared in the same manner except that 2.67 g of polyisobutylene, 7.23 g of aliphatic hydrocarbon resin, 990 mg of antioxidant, and 30 g of toluene were used.
In this example, the sealing material was evaluated by the following method.

<Appearance test>
The adhesive sheet was bonded to the barrier film (VIEW-BARRIER, manufactured by Mitsubishi Plastics) using a roll laminator as shown in the following configuration (1).
Configuration (1): barrier film / adhesive sheet B / adhesive sheet A / release film.
Then, it cut into a square with a side of 50 mm, and bonded using a vacuum laminator as shown in the following configuration (2).
Configuration (2): Barrier film / adhesive sheet B / adhesive sheet A / adhesive sheet A / adhesive sheet B / barrier film.

Then, visual evaluation was performed about the bubble generation condition.
Lamination was performed under the following conditions.
Roll laminator: G / B / C roll laminator B316A3
Roll laminating conditions: 60 ° C, speed 1m / min
Vacuum laminating machine: NPC vacuum laminator LM 30x30
Vacuum lamination conditions: 120 ° C, vacuum 2 min, pressure 2 min (99 kPa)

<Tackiness>
About the front and back of each adhesive sheet, the adhesive sheet surface was measured 3 times on the following conditions, and the average value was made into the tack value.
Apparatus: Brookfield, CT3-4500
Probe material: Acrylic φ12.7 (Model number: TA10)
Approach speed: 0.5mm / min
Applied pressure: 200g
Pressurization time: 30 seconds Pulling speed: 0.5 mm / min
Temperature: 23 ° C

<Adhesiveness>
Evaluation was performed based on JIS K 6854.
Composition: Barrier film / adhesive sheet / adhesive sheet / barrier film sample preparation conditions, vacuum laminator 120 ° C., vacuum 10 min, pressurization 3 min
Peeling conditions: T-type peel test, peel speed 100 mm / min
Equipment: Desktop material testing machine: STB-1225L
Temperature: 23 ° C

<Water vapor transmission rate>
Based on JIS Z0208, the water vapor transmission rate was measured by the Viton method under the following conditions.
Conditions: 40 ° C., 90% RH, film thickness 50 μm conversion.

Example 2
An adhesive sheet C (film thickness 60 μm) was prepared in the same manner as the adhesive sheet A of Example 1 except that 3.17 g of polyisobutylene, 4.75 g of aliphatic hydrocarbon resin, 792 mg of antioxidant, and 32 g of toluene were used. Created. After that, when pasting with a barrier film with a roll laminator, the high tack surface side of the adhesive sheet C was made to be the barrier film side. Otherwise, the evaluation was performed in the same manner as in Example 1.

Comparative Example 1
Evaluation was performed in the same manner as in Example 1 except that M-2 manufactured by Kurabo Industries was used as the adhesive sheet.
Comparative Example 2
Evaluation was performed in the same manner as in Example 1 except that FWD-50 manufactured by Niei Engineering Co., Ltd. was used as the adhesive sheet.
Comparative Example 3
Evaluation was performed in the same manner as in Example 1 except that the adhesive sheet A was used as the adhesive sheet.

Comparative Example 4
Evaluation was performed in the same manner as in Example 1 except that the adhesive sheet B was used as the adhesive sheet.
Comparative Example 5
Evaluation was performed in the same manner as in Example 1 except that the adhesive sheet C was used as the adhesive sheet and the low tack surface side was bonded to the barrier film side.

  As is clear from the above evaluation results, the adhesive sheet of the present invention can be suitably used as a sealing material for organic electronic devices because of its high gas barrier properties and adhesiveness, and has low tackiness on the element side, so that rework is easy and the process It turns out that it is excellent in property. Moreover, since there are few bubble entrainment, the organic electronic device excellent in the designability can be provided.

DESCRIPTION OF SYMBOLS 1 Organic thin film solar cell module 11 Front surface protective layer 12 Back surface protective layer 13 Organic thin film solar cell element 14 Current collector 15 Sealing material

Claims (8)

  An adhesive sheet comprising an isobutylene-based elastomer, wherein one surface has a different tack from the other surface.   The adhesive sheet according to claim 1, comprising at least one kind of tackifying resin.   The adhesive sheet according to claim 2, wherein the composition ratio of the isobutylene elastomer and the tackifying resin is different between one surface and the other surface of the adhesive sheet.   The adhesion according to any one of claims 1 to 3, wherein the adhesive sheet is an adhesive sheet composed of two or more layers, and has a layer made of a composition containing an isobutylene elastomer on at least one surface. Sheet.   The method for producing an adhesive sheet according to any one of claims 1 to 4, wherein the adhesive sheet coating liquid is applied on a substrate and then dried.   The method for producing an adhesive sheet according to any one of claims 1 to 4, wherein two or more adhesive sheets are bonded together.   A laminate comprising the adhesive sheet according to claim 1 and a barrier film laminated.   An organic electronic device having a first barrier layer, a first sealing layer, an organic electronic element, a second sealing layer, and a second barrier layer in order, wherein at least one of the first sealing layer and the second sealing layer is An organic electronic device comprising the adhesive sheet according to claim 1.

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