JP2014104406A - Solar cell module recycling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar sell module recycling method which has a small environmental load and good energy efficiency, and does not affect quality of separated and collected material.SOLUTION: There is provided a solar cell recycling method for separating a solar cell module formed by laminating a solar cell enclosed by sealant, a light-receiving surface glass and a back sheet, into each material. The method includes a preceding step of peeling the back sheet mechanically, a separation step of immersing the solar cell module from which the back sheet is peeled into a peeling agent solution to separate glass, and a step of separating sealant and solar cell into sealant and metals and collecting them. As a peeling agent, neutral peeling agent including hydrocarbon solvent agent is used.

Description

  The present invention relates to a method for recycling a solar cell module in which a solar cell module formed by laminating a solar cell surrounded by a sealant, a light receiving surface glass, and a back sheet is separated into each material.

  In recent years, solar cells have been installed in various places such as public facilities, factories, power plants, and general households from the viewpoint of environmental concerns and energy problems. Since the solar cell uses clean energy called sunlight, it is effective in reducing the load on the environment. However, there is a need to treat solar cells that are no longer needed due to their service life, damage, replacement, etc., and defective products in the manufacturing process. Establishing recycling is an important issue. It has become.

  Various materials such as a solar cell element that realizes photoelectric conversion, a light-receiving surface glass substrate that protects the solar cell element, and a sealant that bonds each member are used for the solar cell module. It is said that the service life of a product due to age-related deterioration in use in harsh environments always exposed to light, reduced light transmission, deterioration of mechanical properties, etc. is generally 20-30 years, after which it is discarded Is the current situation. However, depending on the constituent members, the light-receiving surface glass, the solar battery cell, the aluminum material of the back surface material, and the metal material of copper or aluminum can be used sufficiently, and are required to be separately collected and reused.

  From the ethylene-vinyl acetate copolymer (EVA) firmly fixed to the solar cell module, the light-receiving surface glass, solar cell, and back material (back sheet) constituting the solar cell module are separated and recovered from the solar cell module. It is necessary to separate and remove the sealing agent. However, EVA that is firmly bonded to glass or metal is crosslinked, so that it is not easy to separate and remove, and various recycling methods for separating and removing solar cell modules have been studied.

  For example, a method for taking out a solar cell substrate material in which a solar cell module is immersed in an acid solution, an alkaline solution or an organic solvent solution and then the ethylene-vinyl acetate copolymer is burned and removed is proposed (Patent Document 1). ). However, both acid and alkali solutions must be strong acid and strong alkali solutions, and organic solvents also require measures such as environmental conditions for use, waste liquid treatment, etc., and require very high energy costs for equipment and combustion. However, it is not satisfactory as a recycling method.

  There has been proposed a method for taking out a solar cell substrate material by taking out the substrate material in the solar cell by exposing the solar cell module to a supercritical atmosphere or a subcritical atmosphere to decompose EVA (Patent Document 2). However, equipment and costs are high to create a state in a supercritical atmosphere or a subcritical atmosphere, and energy costs are very high for taking out the substrate material, which is not satisfactory as a recycling method.

  Furthermore, as a recycling method of the solar cell module, a crushing step of crushing the glass material and the solar cell element, a softening step of heating and softening the crushed glass material and the filler that adheres to the solar cell element, a glass material, and In the module in which the solar cell element is crushed, a separation step of separating the back surface protection material by applying a blade to the softened filler, and a pulverization step of crushing the glass material and the solar cell element from which the back surface protection material has been separated, A recycling method for solar cell modules has been proposed (Patent Document 3). However, there is a problem that separation from the filler cannot be ensured because the blade is applied to the heat-softened filler.

  Any of the above conventional processing methods may affect the quality of the separately collected members, glass, and metal members themselves, resulting in poor recycling efficiency, cost for processing equipment, and problems in use environment. However, there is a problem in the treatment of the waste liquid after treatment, the environmental load is large, the energy efficiency is low, and there is no recycling method that can be satisfactorily satisfied.

JP 2005-31178 A JP 2006-93336 A JP 2011-173099 A

  The present invention is a solar cell module recycling method for separating a solar cell module formed by laminating a solar cell surrounded by a sealant, a light-receiving surface glass, and a back sheet into each material, and separated into each material. Recycling of solar cell modules that do not affect the quality of the components, are safe with no problems with the processing equipment and usage environment, and can be easily separated into each material without problems of waste liquid treatment after processing. It is an object to provide a method.

  As a result of earnest studies to solve the above-mentioned problems, the present inventors have, as a solar cell module recycling method for separating the solar cell module into each material, a pre-process for mechanically peeling the back sheet of the solar cell, It has a separation step of separating the glass by immersing it in a release agent solution, and a step of separating and recovering the sealant and the solar battery cell into a sealant and metals, and the release agent contains a neutral solvent containing a hydrocarbon solvent. The present inventors have found a method for recycling a solar cell module using an agent, and have reached the present invention.

That is, the present invention is as follows.
[1] A solar cell module recycling method for separating a solar cell module formed by laminating a solar cell surrounded by a sealant, a light-receiving surface glass, and a back sheet into each material, the solar cell module A step of mechanically peeling the back sheet, a separation step of separating the glass by immersing it in a release agent solution, a step of separating and recovering the sealant and the solar cells into a sealant and metals, and peeling A method for recycling a solar cell module, comprising using a neutral release agent containing a hydrocarbon solvent as the agent.
[2] The step of separating and recovering the encapsulant and the solar battery cell into the encapsulant and the metal includes the step of pulverizing the encapsulant and the solar cell, and the pulverized encapsulant and the solar cell as a release agent. The method for recycling a solar cell module according to [1], which includes a step of immersing in a solution and separating and separating into a sealant and a metal.
[3] The solar cell module recycling method according to [1] or [2], wherein an NC router grinding machine is used in a pre-process for mechanically peeling the back sheet of the solar battery.
[4] In any one of [1] to [3], in the separation step in which the glass is separated by dipping in a release agent solution, ultrasonic treatment is used in combination with the release agent solution heated in the immersion. To recycle solar cell modules.
[5] The release agent in the step of immersing the pulverized sealant and the solar battery cell in the release agent solution to release and separate the sealant and the metal is a propylene glycol solvent or / and a dialkyl glycol solvent. The method for recycling a solar cell module according to any one of [2] to [4], which is an alkaline release agent containing

  According to the recycling method of the present invention, there is no effect on the quality of components separated into each material, there is no problem in terms of processing equipment and use environment, and there is no problem in waste liquid treatment after processing, and a solar cell module is easy. It is possible to provide a method for recycling solar cell modules that can be separated into various materials.

It is a basic section structure figure of a solar cell module used for a recycling method of the present invention. It is process drawing which shows the recycling method which concerns on one Embodiment of this invention.

  The present invention will be specifically described below. The solar cell module which is the object of the recycling method of the present invention has a structure in which the solar cells shown in FIG. 1 are surrounded by a sealant as a basic structure, and a light receiving surface glass and a back surface backsheet are laminated. Solar cell modules that are no longer necessary due to the passage of life, damage, replacement by purchase, etc., or solar cell modules such as defective products in the manufacturing process are subject to recycling.

  Prior to the recycling method of the present invention, first, as a pretreatment, the terminal box and the frame of the solar cell module are removed. The recycling method of the present invention includes a pre-process for mechanically peeling the back sheet of the solar cell module having the basic structure described above, a separation step for separating the glass by immersing the solar cell module in a release agent solution, and a sealing agent. And a step of separating and collecting the solar battery cell into a sealant and a metal. Furthermore, the recycling method includes a step of separating and recovering the sealant and the solar battery cell into a sealant and a metal, a step of pulverizing the sealant and the solar cell, and a pulverized sealant and solar cell. It is preferable to have a step of immersing the cell in a release agent solution to separate and separate the sealant and metals.

  A specific example of the recycling method of the present invention is shown in FIG. First, as step 1 (grinding), there is a step of mechanically peeling the back sheet of the solar cell module, which is a previous step. In this pre-process, it is a process which peels the back sheet | seat which exists in the back surface of a solar cell module and prevents that the moisture from the outside penetrate | invades. The back sheet is made of, for example, a sheet formed by laminating a fluorine resin, a polyester resin, an aluminum foil, and the like. The back sheet has low moisture permeability and high mechanical strength.

  As the grinding device, any device that mechanically grinds the back sheet may be used. For example, a wire brush, a cutter, a cutting tool or the like can be used. In particular, when an NC router grinding machine is used as a grinding device, the backsheet can be ground accurately and reliably based on the dimensional data of the target solar cell module. Furthermore, in order to improve the penetration of the release agent solution in the separation step of separating the glass, which is the next step after the back sheet is peeled off by the NC router grinding machine, the sealing agent surface of the peeled back sheet is formed in a grid pattern. A slit can be inserted simultaneously. Any slit may be used as long as it allows efficient penetration of the release agent solution. For example, slits can be formed in a lattice shape with a width and depth of about several mm.

  The recycling method of the present invention includes, as step 2 (immersion), a separation step in which the solar cell module from which the back sheet has been mechanically separated is immersed in a release agent solution to separate the glass. The solar cell module that has been ground in step 1, that is, surrounded by the sealing agent from which the back sheet is mechanically peeled, and the light-receiving surface glass is immersed in a release agent solution, and the release agent is removed. In this step, the light-receiving surface glass is peeled off by permeating into the sealant. What is necessary is just to perform the time process which can peel the light-receiving surface glass, for example, the immersion process is an immersion process for about 1 hour or more and 20 hours. The mechanism of action by immersion is thought to be due to reaction diffusion that repeats swelling and interfacial peeling, and the sealant swells and undergoes volume change due to the release agent, resulting in shear stress between the unchanged glass and peeling. it is conceivable that. It is more preferable to use ultrasonic vibration together in a high-temperature release agent solution tank, whereby the release time of the sealant can be further shortened in the high-temperature solution. The ultrasonic vibration may be one cycle or a combination of two or more cycles.

  As the release agent solution used in Step 2 (immersion), a neutral release agent containing a hydrocarbon solvent is used. In a solar cell module, a material having good light transmission, weather resistance, moisture resistance, adhesion, and electrical characteristics such as mechanical characteristics, electrical insulation, and voltage resistance is used as a sealant. . For example, ethylene-vinyl acetate copolymer (EVA) and polyvinyl butyral (PVB) are often used, but these resins are cross-linked and firmly fixed to protect the solar cell, so that the light-receiving surface glass is separated. It is very difficult to do, but by using a neutral release agent containing a hydrocarbon solvent, it can penetrate into the sealant and swell the resin component, and easily peel off the light-receiving surface glass Can do.

  The neutral release agent preferably contains mainly a hydrocarbon solvent or an acetate solvent. Examples of the hydrocarbon solvent include straight-chain hydrocarbons having 5 or more carbon atoms such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, and hexadecane, isopentane, Any branched hydrocarbon having 5 or more carbon atoms such as isohexane, isoheptane, isooctane, isononane, isodecane, isoundecane, isododecane, isoundecane, isododecane, isotridecane, isotetradecane, isopentadecane, isohexadecane, 1-pentene, Examples thereof include α-olefins having 5 or more carbon atoms such as 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene. More preferred are isohexane, isopentane, isododecane, isotridecane, 1-hexene, 1-octene, 1-dodecene and 1-tetradecene. The content of the hydrocarbon solvent in the neutral release agent is preferably 10 to 70% by weight, more preferably 20 to 70% by weight.

  Examples of acetate solvents include 3-methoxy-3-methyl-1-butyl acetate, dipropylene glycol methyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, and propylene glycol diacetate. It can be illustrated. Preferable examples include 3-methoxy-3-methyl-1-butyl acetate and dipropylene glycol methyl ether acetate. The content of the acetate solvent in the neutral release agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight.

  The neutral release agent is preferably a solubilizing agent that uses a surfactant, glycol solvent or alcohol solvent, and can be made a release agent having no flash point by solubilizing the hydrocarbon solvent in water. . The content of the solubilizer in the neutral release agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight. Moreover, you may add the penetrant which improves penetration. As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant can be contained, and among these, it is preferable to use a nonionic surfactant. . The content of the surfactant in the neutral release agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight.

  The glycol solvent is selected from aliphatic glycols and aromatic glycols. Aliphatic glycols include ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, methyl diglycol, methyl triglycol, isopropyl diglycol, butyl diglycol, hexyl glycol, hexyl diglycol, 2-ethylhexyl glycol, 2-ethylhexyl Examples of the aromatic glycol include benzyl glycol, benzyl diglycol, benzyl triglycol, phenyl glycol, and phenyl diglycol. Although at least one of these is included, two or more of these may be used in combination. The content of the glycol solvent in the neutral release agent is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight.

  Examples of the alcohol solvent include monovalent alcohol solvents, and are selected from aliphatic alcohols and aromatic alcohols. Examples of the aliphatic alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, and butyl alcohol. Examples of the aromatic alcohol include benzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, and phenoxyethanol. Of these, benzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, and phenoxyethanol as the aromatic alcohol are preferably selected. Particularly preferred are benzyl alcohol and phenoxyethanol. The content of the alcohol solvent is preferably 0.1 to 5% by weight, more preferably 1 to 5% by weight.

  Examples of penetrants include acetylene surfactants, ethylene oxide addition type nonionic surfactants, and alkylsulfonic acid anionic surfactants. Preferably, acetylene surfactants can be used. Although at least one of these is included, two or more of these may be used in combination. The content of the penetrant is preferably 0.1 to 5% by weight, more preferably 0.1 to 3% by weight.

  Water can be contained as a neutral release agent. The water may be tap water, distilled water, ion exchange water, pure water or the like. The water constituting the neutral release agent of the present invention is for dissolving the surfactant component, and is a hydrocarbon solvent, acetate solvent, glycol solvent, alcohol solvent, surfactant, penetrant. Etc. can be added. Since the neutral release agent of the present invention contains water as a component, it can be said to be a semi-aqueous release agent.

  Preferred neutral release agents include 10-70% by weight of 1-dodecene or 1-tetradecene as a hydrocarbon solvent, and 3-methoxy-3-methyl-1-butyl acetate or dipropylene glycol methyl as an acetate solvent. 5-20% by weight of ether acetate, 2-ethylhexyl diglycol as a solubilizer, nonionic surfactant, 5-20% by weight of benzyl alcohol or phenoxyethanol, acetylene surfactant as penetrant It is preferable to contain 0.1 to 5% by weight of remaining water.

  The recycling method of the present invention includes a step of separating and recovering the sealing agent and the solar battery cell into the sealing agent and metals as the next step. This is a step of separating and recovering the light-receiving surface glass separated in step 2, that is, the solar cell module that has become the sealant and the solar battery cell, into the metal constituting the sealant and the cell. In this separation and recovery process, the solar cell module that has become the separated sealant and solar cell is crushed and finely divided, and the sealant and cell made of synthetic resin are configured based on the specific gravity difference of the material there. This is a process of separating and recovering metals such as metal and silicon.

  In this step, by crushing the solar cell module that has become a sealing agent and solar cells, fine particles consisting only of the sealing agent, fine particles consisting only of the metal constituting the cell, and adhesion of the sealing agent Can be separated into fine metal particles. Through the steps so far, the light-receiving surface glass can be completely separated from the solar cell module and can be reliably recovered.

  The step of separating and recovering the sealant and the solar battery cell as the step of the present invention into a sealant and metals is preferably further divided into two steps. As two steps, as a first step of separating and recovering the sealant and the metal, a step of pulverizing the sealant and the solar battery cell is provided, and then the crushed sealant and the solar battery cell There is a step of immersing the laminate in a release agent solution to release and separate the sealant and metals.

  What is necessary is just to perform as a process which grind | pulverizes sealing agent and a photovoltaic cell using the apparatus used by a normal grinding | pulverization process, for example, a crushing mill. This step can be exemplified as step 3 (pulverization) step in FIG. In this pulverization step, since there is no light-receiving surface glass having high hardness, even if there is a wiring portion, it may be pulverized to such an extent that when the sealing agent and the solar battery cell are immersed in the release agent solution, they are separated by the specific gravity difference. Preferably, it may be finely pulverized to about 1 mm to 10 mm.

  The step of immersing the pulverized encapsulant and solar cells in a release agent solution to separate and separate the encapsulant and metals into the encapsulant and the metal is crushed and refined in the step 3 (pulverization) exemplified above. This is a step of immersing the sealing agent and solar battery cell in a release agent solution to separate and separate the sealant and metals. This step can be exemplified as step 4 (immersion / separation) step in FIG. In this immersion / separation process, the laminate of the finely divided sealing agent and the solar battery cell is immersed in a release agent solution, and the release agent is infiltrated into the laminate, and the sealant alone, metal, silicon, etc. Can be separated from the existing metals, and the sealing agent, silicon, copper, silver, and other metals can be separated in the release agent solution based on the specific gravity difference. The immersion / separation step is preferably a treatment time of 30 minutes to 3 hours, more preferably 1 to 2 hours.

  In the above immersion / separation step, the fine particles made only of the sealing agent, the fine particles made only of the metal constituting the cell, and the fine particles made of the metal attached to the sealing agent are further immersed / separated. It is a process. In this step, the sealing agent is permeated and peeled from the fine particles of the sealant-attached metal in the release agent solution. Furthermore, since the specific gravity of the release agent solution is nearly 1.0 and the specific gravity of EVA as the sealant is about 0.9 by stirring the release agent solution, the sealant is the upper layer portion in the release agent solution. The metal such as silicon (specific gravity: 2.3), copper (specific gravity: 8.9), silver (specific gravity: 10.5) becomes the lower layer and is easily separated and recovered with a simple device such as a cyclone. be able to.

  In the immersion / separation step, an alkaline release agent can be preferably used as the release agent solution. More preferably, an alkaline release agent containing a propylene glycol solvent or / and a dialkyl glycol solvent can be used. Since the laminate of the sealant and the solar battery cell is miniaturized, the alkaline release agent penetrates into the interface between the sealant and the metal made of silicon or a metal material, and the solar battery cell made of both of these members The sealing agent in a laminated body can be peeled. Furthermore, by stirring the release agent solution in the release agent solution, EVA as a sealant floats on the upper layer in the release agent solution by using the specific gravity difference, and metals such as silicon, copper and silver are It can be separated from the lower layer and easily separated and recovered with a simple device.

  As the release agent solution used in the dipping / separation step, any alkaline release agent can be used. More preferably, an amine solvent is added to the propylene glycol solvent and / or dialkyl glycol solvent to make it alkaline. A release agent can be used. Further, the alkaline release agent may contain the hydrocarbon solvent, surfactant and water used in Step 2. When an aqueous alkaline stripper is used, it becomes a safe stripper in this recycling operation, and is more preferable.

  Propylene glycol solvents as alkaline release agents include methylpropylene glycol, methylpropylene diglycol, methylpropylene triglycol, propylpropylene glycol, propylpropylene diglycol, butylpropylene glycol, butylpropylene diglycol, butylpropylene triglycol, phenyl Examples thereof include propylene glycol and methylpropylene glycol acetate. Among them, methylpropylene glycol, methylpropylene diglycol and methylpropylene triglycol are preferable.

  Examples of the dialkyl glycol solvent as the alkaline release agent include dimethyl glycol, dimethyl diglycol, dimethyl triglycol, diethyl diglycol, dibutyl diglycol, dimethylpropylene diglycol and the like, among which diethyl diglycol, dimethylpropylene diglycol. Glycol is preferred.

  Examples of amine solvents as alkaline release agents include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, dipropanolamine, tripropanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N , N-dibutylethanolamine, N- (β-aminoethyl) ethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-ethyldiethanolamine, Nn-butylethanolamine, N- Mono-trialkanolamines such as n-butyldiethanolamine, N- (β-aminoethyl) isopropanolamine, N, N-diethylisopropanolamine, 2-ethylhexylamine, cyclohexylamine, dimethylaminocyclo Examples include alicyclic amines such as hexane, aromatic amines such as aniline and toluidine, dialkylamines such as diamylamine, N-methyl-2-pyrrolidone, dimethylformamide, and N, N-dimethylacetamide. , Diethanolamine, triethanolamine, monoisopropanolamine, and dipropanolamine are preferred.

  Examples of alkaline release agents include propylene glycol solvent 20 to 60% by weight, dialkyl glycol solvent 10 to 35% by weight, amine solvent 5 to 15% by weight, hydrocarbon solvent 1 to 10% by weight, and acetylene penetrant. 0.1 to 5%, remaining water. Among them, 30% by weight of dipropylene glycol methyl ether acetate, 49% by weight of methylpropylene triglycol, 10% by weight of monoisopropanolamine, 5% by weight of 1-tetradecene, 1% of acetylene penetrant, and an alkaline release agent as residual water are illustrated. it can.

  In the present invention, the neutral release agent and the alkaline release agent are appropriately added with various additives, for example, antioxidants, ultraviolet absorbers, viscosity modifiers, thickeners, and pigments, as needed. Coloring agents such as fragrances, and fragrances may be added.

  The neutral release agent and the alkaline release agent of the present invention are those in which the above-described components are blended. However, since each component to be used has relatively low volatility, there is little composition variation, and it is stable and good for a long time. The peeling effect can be demonstrated. In addition, since each component does not contain components that have a large effect on the human body, it is safe for work operations, and the release agent is an aqueous liquid, so it can be easily regenerated by replenishing water after long-term use, In addition, liquid management after the peeling process is easy.

  If the immersion used in the step 2 (immersion) and step 4 (immersion / separation) processes of the present invention can bring the release agent of the present invention into contact with a solar cell module laminate or a refined battery module laminate. Any means may be used. Although contact may be performed in the atmosphere at room temperature or under heating by a method such as dipping, coating, spraying, or showering, the use of the release agent under heating can further promote peeling. In particular, a method of detaching the object to be peeled by dipping or swinging in a release agent tank in which the release agent of the present invention is heated to a high temperature is preferable. In Step 2 (immersion), it is more preferable to use ultrasonic vibration in the release agent tank. This can shorten the release time of the sealant in the high temperature liquid. For example, in a stripping agent heated to 60 to 90 ° C., when the ultrasonic vibration is applied in a tank at a frequency of 28 to 135 KHz and a high frequency output of 150 to 600 W, the sealing agent stripping time can be greatly shortened. In particular, the separation efficiency can be further improved by using ultrasonic vibrations having a frequency of 40 KHz and 100 KHz in combination.

  In each step requiring immersion in the present invention, the temperature of the release agent can be used under the condition that water does not evaporate, that is, from room temperature to 90 ° C. It is preferable that the material to be treated is put into a release agent tank heated to 30 to 90 ° C., particularly preferably 50 to 85 ° C. for release treatment. The treatment time may be immersion for 1 to 20 hours, rocking immersion, or ultrasonic vibration immersion, and thereafter removing the release agent by normal cleaning and drying. For example, after washing with water, acetone, isopropyl alcohol, or the like, the release agent may be removed by drying at room temperature.

  By the recycling method of the present invention, each material from the solar cell module formed by laminating a solar cell surrounded by a sealant, a light receiving surface glass and a back sheet, that is, a glass component, a resin component which is a sealant, The silicon component constituting the cell, the metal component constituting the wiring, etc. can be easily separated and recovered. In particular, the light-receiving surface glass and metals can be reused because they have no adhering components and can be recovered intact. On the other hand, the sealant can be recovered in a bulk state and can be easily reused.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

  <Peeling object> As a glass substrate (530 mm × 620 mm × 3 mm), a solar battery cell is placed between a tedora (made by DuPont) as a back sheet, and an ethylene vinyl acetate copolymer (EVA: Hangzhou First PV Material Co) And made at 40 ° C. for 10 minutes, and allowed to stand at room temperature for 2 hours. The thickness of the article was about 3.0 mm, and a 40 W implementation equivalent solar cell dummy module sample was prepared. .

  <Peeling method> The sample was immersed in a release agent bath in which the following various release agents were heated to a liquid temperature of 40 to 80 ° C., and the release treatment was performed for 16 hours.

  <Evaluation means, method> Evaluation of the peeling treatment was performed by examining the time until the glass substrate peels and the peeling state of the glass substrate. The peeling time was evaluated by the time until the glass substrate was completely peeled by visual inspection. The peeled state was evaluated by visual observation of the peeled state of the ethylene-vinyl acetate copolymer.

[Example 1]
Using an NC router grinder, the back sheet of the solar cell module sample was ground and peeled for 15 minutes, and slits were placed on the EVA surface at 1 cm intervals in the vertical and horizontal directions (step 1). Next, a neutral release agent containing a hydrocarbon solvent in the treatment tank (60% by weight of 1-tetradecene, 10% by weight of 3-methoxy-3-methyl-1-butyl acetate, 3% by weight of ethylhexyl diglycol, 1% by weight of benzyl alcohol) %, Acetylene penetrating agent 0.2% by weight, nonionic surfactant 19.8% by weight, remaining water) was heated at 80 ° C. and immersed for 16 hours to peel off the glass substrate (step 2). After the immersion treatment, the remaining photovoltaic cell covered with EVA is crushed with a mill and subjected to a fine graining process of about 1 mm square for 15 minutes, and then EVA metal, a metal composed of silicon and metal. It could be crushed into fine metal particles and EVA fine metal particles. When the fine granules were washed with water, they could be separated into EVA and metals due to the difference in specific gravity. The treatment time was 16.5 hours in total, and the glass could be recovered with the EVA completely peeled off with no EVA visible. The glass collected for confirmation was burned at 500 ° C. for 1 hour, and the total organic matter adhering was measured and found to be 10 ppm.

[Example 2]
Using an NC router grinder, the back sheet of the solar cell module sample was ground and peeled for 15 minutes, and slits were placed on the EVA surface at 1 cm intervals in the vertical and horizontal directions (step 1). Next, a neutral release agent containing a hydrocarbon solvent in the treatment tank (1-tetradecene 60%, 3-methoxy-3-methyl-1-butyl acetate 10%, ethylhexyl diglycol 3%, benzyl alcohol 1%, acetylene series Glass substrate after immersion for 6 hours while applying ultrasonic vibration consisting of two frequencies of 40 kHz and 100 kHz, with the penetration of 0.2% penetrant, 19.8% nonionic surfactant, remaining water) Was peeled off (step 2). After the immersion treatment, the remaining solar cell covered with EVA from which the glass substrate was peeled was crushed using a mill and subjected to a fine graining treatment of about 1 mm square for 15 minutes (step 3). Further, an alkaline stripping agent containing propylene glycol solvent or / and dialkyl glycol solvent in the treatment tank (dipropylene glycol methyl ether acetate 30% by weight, methylpropylene triglycol 49% by weight, monoisopropanolamine 10% by weight, 1-tetradecene 5 wt%, acetylene penetrant 1%, remaining water) was heated at 80 ° C. and immersed for 1 hour while being stirred (step 4). Moreover, EVA fine particles, silicon fine particles, and metal fine particles could be separated and recovered in 30 minutes due to the difference in specific gravity. The treatment time was 8 hours in total, and the peeled state was completely peeled off with no EVA visible on the glass.

  Examples 1 and 2 were a total of 8 hours to 16.5 hours of recycling, and achieved the target within 24 hours. In any of the examples, the glass was recovered intact, there was no deposit on the surface, and the recovery rate was 100%. The sealant could be peeled off at the interface with the cell by a release agent, and could be separated in a bulk state without reattachment. Furthermore, the example which added the grinding | pulverization and the refinement | miniaturization process could separate and collect three types, EVA fine grain, silicon fine grain, and metal fine grain, and was more efficient.

  The present invention is a solar cell module recycling method for separating a solar cell module formed by laminating a solar cell surrounded by a sealant, a light-receiving surface glass, and a back sheet into each material, and separated into each material. It is possible to provide a method for recycling a solar cell module that does not affect the quality of the members, is safe without problems in use environment, and has no problem of waste liquid treatment after treatment, and can easily separate the solar cell module into each material. Regardless of the material such as EVA or PVB, the solar cell module in which the solar cells surrounded by the sealant, the light-receiving surface glass, and the back sheet are laminated can be used as a recycling target.

Claims (5)

A solar cell module recycling method for separating a solar cell module formed by laminating a solar cell surrounded by a sealant, a light-receiving surface glass, and a back sheet into each material,
There is a pre-process for mechanically peeling the back sheet of the solar battery, a separation process for separating the glass by immersing it in a release agent solution, and a process for separating and recovering the sealant and solar cells into a sealant and metals. And the neutral release agent containing a hydrocarbon solvent is used for a release agent, The recycling method of the solar cell module characterized by the above-mentioned.   The step of separating and recovering the sealant and the solar battery cell into the sealant and the metal, the step of pulverizing the sealant and the solar battery cell, and the pulverized sealant and the solar battery cell in the release agent solution The method for recycling a solar cell module according to claim 1, further comprising a step of immersing and separating / separating into a sealant and a metal.   The method for recycling a solar cell module according to claim 1 or 2, wherein an NC router grinding machine is used in a pre-process for mechanically peeling the back sheet of the solar cell.   4. The solar cell module according to claim 1, wherein in the separation step of immersing in a release agent solution and separating the glass, ultrasonic treatment is used in combination with the release agent solution heated for immersion. Recycling method. The release agent in the step of detaching and separating the pulverized sealant and the solar battery cell into the release agent solution to separate and separate the sealant and metals is an alkaline solution containing a propylene glycol solvent or / and a dialkyl glycol solvent. It is a peeling agent, The recycling method of the solar cell module in any one of Claims 2-4 characterized by the above-mentioned.