KR20170091429A - Pressure sensitive adhesive composition, encapsulation sheet for a solarcell having an encapsulating layer comprising the same, and a solar cell module comprising the encapsulation sheet - Google Patents

Abstract

The present application relates to an adhesive composition, an encapsulation sheet for a solar cell having an encapsulating layer comprising cured materials of the composition, and a solar cell module comprising the encapsulation sheet. According to an exemplary adhesive composition, it is possible to provide an encapsulation layer having excellent mechanical and optical characteristics, and excellent resistance to moisture, heat and ultraviolet rays. In addition, the exemplary adhesive composition of the present application omits vacuum, high-temperature, and high-pressure laminating processes, and can perform a roll to roll continuous process, thereby improving production speed and production efficiency.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition, a sealing sheet for a solar cell including a sealing layer containing a cured product of the composition, and a solar cell module including the sealing sheet. BACKGROUND OF THE INVENTION [0002] Conventionally, , AND A SOLAR CELL MODULE COMPRISING THE ENCAPSULATION SHEET}

The present invention relates to a pressure-sensitive adhesive composition, a solar cell encapsulant sheet including an encapsulation layer containing a cured product of the composition, and a solar cell module including the encapsulation material sheet.

Solar power generation is a clean power generation technology that produces electricity from sunlight. Photovoltaic power generation facilities consist of a solar cell (module) that generates electricity by receiving sunlight, a power regulator that converts the generated direct current into alternating current, and a battery that stores the electricity generated in the daytime. Generally, the module that generates electricity is composed of glass, encapsulant, solar cell, and backsheet.

Currently, ethylene-vinyl acetate copolymer (EVA), which is used as an encapsulant, is a substance that is inserted between the front and rear surfaces of the solar cell and the surface material to protect moisture-sensitive solar cell devices. EVA satisfies the characteristics such as transmittance, adhesive force and elasticity to some extent, but requires a separate crosslinking step in vacuum and high temperature, which may lower the production speed and production efficiency of the solar cell module. In addition, EVA has a problem of deteriorating efficiency of a solar cell module due to corrosive substances such as acid generated during crosslinking and yellowing due to long-term ultraviolet exposure.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a solar cell module comprising a pressure-sensitive adhesive composition, a sealing material sheet for a solar cell including a sealing layer containing a cured product of the composition, and the sealing material sheet do.

The present application relates to a pressure-sensitive adhesive composition. The sealing material sheet for a solar cell manufactured using the exemplary pressure-sensitive adhesive composition does not require a crosslinking step such as vacuum pressing (takes about 15 minutes) like the EVA sheet. In addition, the pressure-sensitive adhesive composition can be produced through a roll-to-roll continuous process by applying the adhesive liquid itself and proceeding thermosetting for several minutes, so that the production speed and production efficiency are excellent. In addition, it is superior in moisture resistance than EVA encapsulant by using material resistant to humidity, and it does not cause acid corrosion due to crosslinking unlike EVA, thereby preventing the deterioration of photoelectric devices and enhancing UV cut-off characteristics to suppress yellowing .

Hereinafter, the solar cell module including the solar cell encapsulant sheet and the encapsulation material sheet of the present application will be described in detail with reference to the attached drawings, but the accompanying drawings are exemplary and the solar cell module But is not limited to.

In the present application, the "peeling force" means the peeling force of the sealing layer with respect to the front member, and means the value measured by ASTM D903.

In the present application, the value " Y.I " means the yellowing index and means the value measured by ASTM D1003.

In the present application, the " transmittance " value means the value measured by ASTM D1003.

In the present application, the " Haze " value means the value measured by ASTM D1003.

The pressure sensitive adhesive composition of the present application comprises a pressure sensitive adhesive polymer comprising a copolymer of (meth) acrylate and a reactive ultraviolet stabilizer; And a wavelength conversion material.

The (meth) acrylate refers to a (meth) acrylate and an alkyl (meth) acrylate containing a crosslinkable functional group. In one example, the pressure sensitive adhesive composition of the present application comprises (meth) acrylate containing a crosslinkable functional group And alkyl (meth) acrylate.

The crosslinkable functional group of the (meth) acrylate containing a crosslinkable functional group may be a hydroxy group. Examples of the (meth) acrylate containing a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl Hydroxyalkyl (meth) acrylates such as hydroxyhexyl (meth) acrylate or 8-hydroxyoctyl (meth) acrylate; Or hydroxyalkylene glycol (meth) acrylate such as 2-hydroxyethyleneglycol (meth) acrylate or 2-hydroxypropyleneglycol (meth) acrylate, but is not limited thereto.

As the alkyl (meth) acrylate, for example, alkyl (meth) acrylates having an alkyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, or 1 to 10 carbon atoms can be used. The alkyl group in the above may be, for example, straight chain, branched chain or cyclic. Examples of such monomers are methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, Acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, Isobornyl (meth) acrylate, and the like, and one or more of the above can be selected and used, but the present invention is not limited thereto.

(Meth) acrylate containing a crosslinkable functional group is used in an amount of 3 to 30 parts by weight, 4 to 20 parts by weight, or 5 to 15 parts by weight, based on 100 parts by weight of (meth) acrylate containing an alkyl (meth) acrylate and a crosslinkable functional group. Weight portion. In the above range, the sealing layer formed from the pressure-sensitive adhesive composition can exhibit excellent mechanical properties.

The pressure-sensitive adhesive composition of the present application includes a reactive ultraviolet stabilizer. In one example, the reactive ultraviolet stabilizer may be an acrylic monomer represented by the following formula (1).

[Chemical Formula 1]

Wherein R ¹ is hydrogen or a methyl group, X is a single bond or an alkylene group having 1 to 5 carbon atoms or 1 to 3 carbon atoms, R ² is a phenyl group substituted with an aromatic group, a hydroxyphenyl group substituted with an aromatic group, A phenyl group substituted with an aromatic group or a hydroxyphenyl group substituted with a heteroaromatic group, and in one specific example, R ² may be a hydroxyphenyl group substituted with a benzotriazole group. By adopting the reaction type UV stabilizer as described above, excellent yellowing resistance and excellent peeling force can be secured.

The ultraviolet stabilizer may be 1 to 10 parts by weight or 3 to 8 parts by weight based on 100 parts by weight of (meth) acrylate. The encapsulating material sheet produced from the pressure-sensitive adhesive composition satisfying the above range can ensure excellent optical properties and mechanical properties.

The pressure-sensitive adhesive composition of the present application comprises a wavelength converting material. For example, the wavelength converting material may be an organic pigment. The organic pigment of the present application can be used without any particular limitation as long as it absorbs light of 300 nm to 600 nm, 350 nm to 550 nm, or 378 nm to 524 nm and emits light of 330 nm to 620 nm, 380 nm to 570 nm, or 413 nm to 539 nm. In one example, the organic pigment may be a naphthalene-based organic pigment, and specifically includes naphthalene 1,8: 4,5-tetracarbonic acid diimide, naphthalene- Naphthalene-1,8-dicarbonic acid imide, 4,5-dialkoxynaphthalene-1,8-dicarbonic acid-1,8-dicarboxylic acid monoimide, acid monoimide, 4-phenoxynaphthalene-1,8-dicarbonic acid monoimide, N- (2-ethylhexyl) -4,5-dimethoxynaphthalene- (2-ethylhexyl) -4,5-dimethoxynaphthalene-1,8-dicarbonic acid imide, N- (2,6-diisopropyl-phenyl) -4,5 (2,6-diisopropyl-phenyl) -4,5-dimethoxynaphthalene-1,8-dicarbonic acid imide), N- (7-tridecyl) imide, (7-tridecyl) -4,5-dimethoxy-naphthalene-1,8 dicarbonic acid imide), N- ( 2,6-diisopropylphenyl) -4,5-diphenoxynaphthalene-1,8-dicarboxylic acid imide (N- (2,6-diisopropylphenyl) -4,5-diphenoxynaphthalene-1,8-dicarbonic acid imide, and N, N'-bis (2,6-diisopropylphenyl) -1,8: 4,5-naphthalenetetracarboxylic acid diimide ) -1,8: 4,5-naphthalene tetracarbonic acid diimide), but the present invention is not limited thereto. In one embodiment of the present invention, the organic pigment may be at least one selected from the group consisting of Lumogen F Yellow 083, Lumogen F Orange 240, Lumogen F Red 305 and Lumogen F Violet 570 from BASF.

The wavelength conversion material may be 0.2 to 0.8 parts by weight or 0.3 to 0.7 parts by weight based on 100 parts by weight of the adhesive polymer. The sealing layer made of the pressure sensitive adhesive composition satisfying the above range exhibits excellent mechanical and optical properties.

In one example, the pressure-sensitive adhesive composition of the present application may further comprise a horseradish radical scavenger. The Halscad radical scavenger may be NOR-HALS in one example. By further including the horseshoe radial scavenger in the pressure-sensitive adhesive composition, the sealing layer produced from the pressure-sensitive adhesive composition of the present application can maintain excellent optical characteristics even when exposed to high temperature and high humidity conditions.

The horseradish radical scavenger may be included in an amount of 1 to 5 parts by weight or 1 to 3 parts by weight based on 100 parts by weight of (meth) acrylate. An encapsulating material sheet produced from the pressure-sensitive adhesive composition having the above-mentioned range can secure excellent peel strength and excellent moisture heat resistance.

The present application also relates to an encapsulant sheet for a solar cell. The sealing sheet for a solar cell according to the present application comprises: a substrate; And an encapsulating layer comprising a cured product of the above-described pressure-sensitive adhesive composition.

The base material of the encapsulating material sheet of the present application may be a polymer film. Examples of the base material include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate Selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) It is either.

In the sealing sheet for a solar cell according to the present application, the specific content of the pressure-sensitive adhesive composition is the same as that described in the above-mentioned portion relating to the pressure-sensitive adhesive composition, and therefore will be omitted.

The sealing layer made of the pressure-sensitive adhesive composition of the present application has a peel force (ASTM D903) of 800 gf / in to 1200 gf / in or 900 gf / in to 1100 gf / in on the front member.

The present application also relates to a solar cell module comprising an encapsulation sheet of the present application. In the solar cell module of the present application, the details of the encapsulation material sheet are the same as those described above in connection with the encapsulation material sheet, and therefore will not be described.

The pressure-sensitive adhesive composition according to the present invention can improve the crosslinking density by applying the composition itself and proceeding thermosetting within a few minutes, thus enabling a roll-to-roll continuous process. Thus, production speed and production efficiency are improved. In addition, the pressure-sensitive adhesive composition according to the present application has excellent mechanical properties and anti-wet heat characteristics, including wavelength conversion pigments.

FIG. 1 is a view illustrating an exemplary solar cell module according to an embodiment of the present application.
Figure 2 is a simplified view of a laminate made according to an embodiment of the present application.

Hereinafter, the present invention will be described in more detail by way of Experimental Examples, but the following Examples are for explaining the present invention only in detail and are not intended to limit the scope of the present invention.

A laminate 200 made of glass 210, an encapsulating layer 220 and a substrate 230 was prepared as shown in Fig. Mechanical properties and optical properties of the pressure sensitive adhesive composition were measured according to the contents of the wavelength conversion pigments contained in the pressure - sensitive adhesive composition and the inclusion of a horseradish radical scavenger.

Experimental Example  One

50 parts by weight of 2-ethylhexyl acrylate (EHA) (142.9 g) and 40 parts by weight of methyl acrylate (MA) (114.3 g) were added to a 1 L reactor equipped with a cooling device ), 10 parts by weight (28.6 g) of 2-hydroxyethyl acrylate (HEA) and 5 parts by weight (14.3 g) of RUVA-93 as a reactive ultraviolet absorbent of Otsuka Chemical Co. were added. Subsequently, 700 g of ethyl acetate (EAc) was poured into the solvent, nitrogen gas was purged for 60 minutes to remove oxygen, and the reaction initiator V-65 (2,2 '-azobis (2,4-dimethyl valeronitrile)) at 1400 ppm (0.42 g). Thereafter, the reaction was conducted for about 5 hours to prepare a sticky polymer (EMH-R). Further, according to the sample, a composition containing the above adhesive polymer was further added to Lumogen F Violet 570, a wavelength conversion pigment of BASF, to prepare a pressure-sensitive adhesive composition sample capable of forming the pressure-sensitive adhesive layer as shown in Table 1 below.

The solid content of the pressure-sensitive adhesive is 26.24%. Methyl ethyl ketone (MEK) was added to the pressure-sensitive adhesive so that the solid content became 25%, and 0.125% of TAKENATE D-110N isocyanate crosslinking agent of Mitsui Chemical Co. was added to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was coated on one side of A4200 PET manufactured by TOYOBO Co., Ltd. to a thickness of about 30 mu m and dried at 120 DEG C for 2 minutes to form a pressure-sensitive adhesive layer. Covered with Rf-02N type PET of SKC Haas, and then aged in a 40 ° C oven for 48 hours. Thereafter, the release-treated PET film was peeled off from the glass to produce a laminate to obtain a sample.

It can be seen from Table 1 that the peeling force is remarkably reduced when the wavelength converting pigment is included in the pressure sensitive adhesive composition beyond a specific range.

(85 ° C, 85% RH, 2000 hr test) in which the laminate prepared by using the pressure-sensitive adhesive described in Table 1 was allowed to stand at 85 ° C. and 85% relative humidity for 2000 hours. Ultraviolet rays were irradiated for 2000 hours And an explosion test (Q-UVB test). The results are shown in Table 2 below.

From the above Table 2, it was found that, in the case of the pressure-sensitive adhesive composition (EMH (refer.)) Not containing the ultraviolet stabilizer and the wavelength conversion pigment, the test results showed that the optical properties were significantly worse than before the test. In addition, in the case of the pressure-sensitive adhesive composition containing only the ultraviolet light stabilizer or containing the wavelength conversion pigment in a specific amount together with the ultraviolet light stabilizer, it can be seen that the initial optical properties remain relatively good even after the test.

Experimental Example  2

50 parts by weight of 2-ethylhexyl acrylate (EHA) (142.9 g) and 40 parts by weight of methyl acrylate (MA) (114.3 g) were added to a 1 L reactor equipped with a cooling device ), 10 parts by weight (28.6 g) of 2-hydroxyethyl acrylate (HEA), 5 parts by weight (14.3 g) of RUVA-93 as a reactive ultraviolet absorbent of Otsuka Chemical Co. and NOR-HALS 2 parts by weight (5.72 g) was added thereto. Subsequently, 700 g of ethyl acetate (EAc) was poured into the solvent, nitrogen gas was purged for 60 minutes to remove oxygen, and the reaction initiator V-65 (2,2 '-azobis (2,4-dimethyl valeronitrile)) at 1400 ppm (0.42 g). Thereafter, the reaction was carried out for about 5 hours to prepare a sticky polymer (EMH-RH). Lumogen F Violet 570, a wavelength-converting pigment of BASF, and Tinuvin 123, a Halss radical scavenger of BASF, were also added according to the samples to prepare pressure sensitive adhesive samples as shown in Table 3 below.

The solid content of the pressure-sensitive adhesive is 23.43%. Methyl ethyl ketone (MEK) was added to the pressure-sensitive adhesive so as to have a solid content of 20%, and 0.125% of TAKENATE D-110N isocyanate crosslinking agent of Mitsui Chemical Co. was added to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was coated on one side of A4200 PET manufactured by TOYOBO Co., Ltd. to a thickness of about 30 mu m and dried at 120 DEG C for 2 minutes to form a pressure-sensitive adhesive layer. Covered with Rf-02N type PET of SKC Haas, and then aged in a 40 ° C oven for 48 hours. Thereafter, the release-treated PET film was peeled off from the glass to produce a laminate to obtain a sample.

From Table 3, it can be seen that the peel strength of the seal layer made of the pressure-sensitive adhesive composition can be remarkably reduced depending on the kind of the Halss radical scavenger.

From Table 4, it is confirmed that the sealing layer made of the pressure-sensitive adhesive composition containing NOR-HALS maintains excellent optical characteristics in the anti-wet heat test and the ignition test.

100: solar cell module
110: substrate layer
120: encapsulant layer
130: front member
140: Solar cell
200: laminate
210: glass
220: encapsulant layer
230: substrate

Claims (12)

A tacky polymer comprising a copolymer of (meth) acrylate and a reactive ultraviolet stabilizer; And 0.2 to 0.8 parts by weight of a wavelength converting material based on 100 parts by weight of the pressure-sensitive adhesive polymer. The method according to claim 1,
(Meth) acrylate comprises a (meth) acrylate and an alkyl (meth) acrylate containing a crosslinkable functional group. 3. The method of claim 2,
Wherein the (meth) acrylate containing a crosslinkable functional group is 3 to 30 parts by weight based on 100 parts by weight of the total (meth) acrylate. The method according to claim 1,
Wherein the ultraviolet light stabilizer is an acrylic monomer represented by the following formula (1):
[Chemical Formula 1]

Wherein R ¹ is hydrogen or a methyl group, X is a single bond or an alkylene group having 1 to 5 carbon atoms, R ² is a phenyl group substituted with an aromatic group, a hydroxyphenyl group substituted with an aromatic group, a phenyl group substituted with a heteroaromatic group Or a hydroxyphenyl group substituted with a heteroaromatic group. The method according to claim 1,
Wherein the content of the ultraviolet light stabilizer is 1 to 10 parts by weight based on 100 parts by weight of the (meth) acrylate. The method according to claim 1,
Wherein the wavelength conversion material is an organic pigment. The method according to claim 6,
Wherein the wavelength converting material is an organic pigment that absorbs light of 300 to 600 nm and emits light of 330 to 620 nm. The method according to claim 6,
Wherein the wavelength conversion material is a naphthalene-based organic pigment. The method according to claim 1,
Wherein the tacky polymer further comprises a horseradish radical scavenger. 10. The method of claim 9,
Wherein the content of the radical scavenger is 1 to 5 parts by weight relative to 100 parts by weight of (meth) acrylate. materials; And
A pressure-sensitive adhesive composition comprising a sealing layer comprising a cured product of the pressure-sensitive adhesive composition of claim 1,
Wherein the sealing layer has a peeling force (ASTM D903) of 800 gf / in to 1200 gf / in. A solar cell module comprising the encapsulating material sheet of claim 11.

Images