JP2011020375A - Method of manufacturing low-shrinkable resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain low-shrinkable resin film having a low shrinkage even by reheating when sticking, and to improve heat adhesive property. <P>SOLUTION: In a method of a low-shrinkable resin film, the resin film 47 wherein a film-like resin material 15 for a sealing film extrusion-molded from a die 39 is moved to develop on a sheet substrate 11 fed out, is melted on the sheet substrate 11 by heating the film-like resin material 15 with the sheet substrate 11 together, and the film-like resin material 15 on the sheet substrate 11 is cooled after being pressurized with an emboss roller 21 and integrally laminated with the sheet substrate 11, is formed and the low-shrinkable resin film 49 comprising the sheet substrate 11 and the resin film 47 is taken up. The sheet substrate 11 fed out is supported on an endless conveying belt 37 and supported on a conveying belt 37. The film-like resin material 15 on the sheet substrate 11 can be melted by being heated with the conveying belt 37 together. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a low shrinkage resin film.

  In order to produce resin films such as optical films and functional films, it is common to extrude the heat-melted resin material from a die (die), pull it under tension and wind it up to make a product. is there. Extruded from the die onto the back sheet, pulled with the back sheet with a pressure roller, and formed into a desired thickness by passing through this roller, that is, the speed in the pulling direction was made faster than the extrusion speed at the time of molding, Further, it is molded to a desired thickness by applying pressure with a roller and simultaneously cooled, and then wound while being peeled off from the back sheet (see, for example, Patent Document 1).

  One example of the resin film thus obtained is an EVA film for a sealing film of a solar cell, for example. Generally, a solar cell is a cell for a solar cell such as a silicon power generation element by a resin film (EVA film) which is a sealing film between a glass substrate as a front surface side transparent protective member and a back sheet as a back surface side protective member. It is set as the structure which sealed. That is, a glass substrate, an EVA film for sealing film, a silicon power generation element, an EVA film for sealing film, and a backsheet are laminated in this order, and heated and pressed to crosslink and cure EVA to bond and integrate. Is done. The EVA film for sealing film is obtained by extruding a molten resin from a die having a linear slit as a die and rapidly cooling and solidifying with a cooling roll or the like. This type of resin film is subjected to embossing for the purpose of improving adhesiveness by improving handling and air escape, and imparting unevenness to the surface.

  When embossing is performed as the resin film, particularly when a double-sided embossed resin film is manufactured, the back sheet is embossed, and the film material is superimposed on this and passed through a pressure roller. In addition, embossing is also performed on one side of the pressure roller, whereby embossing is formed on both sides, and the film is wound after being cooled. When the embossed resin film is laminated on a glass surface or the like, the air is easily removed, and the weldability and pressure adhesion can be improved.

Japanese Patent Publication No. 1-52428

However, bonding to integrate a resin film with a glass substrate or the like is generally a process of heating and bonding, and this heating causes the resin film to have a distortion at the time of production, that is, to apply a tension to be wound. Deformation occurs in the shrinking (shrinking) direction due to internal strain caused by the elongation in the winding direction. Therefore, by reheating in the above process, shrinkage is caused to return to the size (length) immediately after molding, that is, before winding. In the winding axis direction, which is the width direction orthogonal to the resin film forming direction, almost no tension is applied at the time of winding, and the shrinkage rate upon reheating is extremely small and can be ignored.
Conventionally, in the resin film sticking step, heat bonding has been performed in consideration of shrinkage in order to avoid molding defects. For this reason, stacking the glass substrate and the resin film, sandwiching them with a heating plate (heater) from both outer surfaces, cutting the resin film longer in the winding direction than the surface area of the glass, and complicated dimensional adjustment that takes into account shrinkage The adhesion process by was required. Further, if the shrinkage rate could not be determined, warping occurred and the quality was lowered. In particular, when a current-carrying configuration is provided as in the above-described solar cell, the circuit forming layer and the resin film are overlapped. Therefore, if the amount of shrinkage is large, the circuit may be cut and a product may be defective.

  The present invention has been made in view of the above situation, and provides a method for producing a low-shrinkage resin film that is small in shrinkage even by reheating at the time of sticking, and thus aims to improve heat adhesion. .

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
In the method for producing a low shrinkage resin film according to claim 1 of the present invention, the film-like resin material 15 for the sealing film that is extruded from the die 39 is stretched on the sheet base material 11 that is sent out,
Heating the film-like resin material 15 together with the sheet base material 11 to melt it on the sheet base material 11,
The film-like resin material 15 on the sheet base material 11 is pressurized with an embossing roller 21 and then cooled to form a resin film 47 laminated integrally with the sheet base material 11;
The resin film 47 is wound together with the sheet base material 11.

  In this method for producing a low shrinkage resin film, a sheet base material 11 having a relatively small shrinkage rate is used, and shrinkage at the time of heat bonding after becoming a product is reduced. Since the heat melting treatment is performed on the sheet base material 11, the distortion at the time of molding is reset (internal stress is removed), and the sheet base material supports the film-like resin material that melts by heating, and becomes a product. Shrinkage during heat bonding is reduced. Rather than recycling using, for example, paper as a support, manufacturing costs and product costs are greatly reduced by using the sheet base material (back sheet) 11 that is a component in the next process (solar cell production). It becomes possible.

The method for producing a low shrinkage resin film according to claim 2 is a method for producing the low shrinkage resin film according to claim 1,
The sheet base material 11 that is fed out is supported on an endless conveyance belt 37,
The film-like resin material 15 on the sheet base material 11 supported on the conveyor belt 37 is heated and melted together with the conveyor belt 37.

  In this method for producing a low shrinkage resin film, the film-like resin material 15 is heated and melted on the sheet base material 11 supported by the flat conveying belt 37, and unevenness due to flow (non-uniform thickness) is less likely to occur. .

The method for producing a low shrinkage resin film according to claim 3 is the method for producing a low shrinkage resin film according to claim 1 or 2,
Before the film-shaped resin material 15 is spread, the sheet base material 11 is preheated.

  In this method for producing a low shrinkage resin film, a rapid temperature drop of the film-like resin material 15 delivered from the die 39 does not occur.

The method for producing a low shrinkage resin film according to claim 4 is the method for producing a low shrinkage resin film according to any one of claims 1, 2, and 3,
After the resin film 47 is formed, the sheet base material 11 is wound inside together with the resin film 47.

  In this method of producing a low shrinkage resin film, the resin film 47 rich in stretchability is wound up on the front side, so that the wrinkle ( The occurrence of defects such as i) and cracks is less likely to occur in the low-shrink resin film 49 as a product.

The method for producing a low shrinkage resin film according to claim 5 is the method for producing a low shrinkage resin film according to any one of claims 1, 2, 3, and 4,
The film-like resin material for the sealing film is an ethylene-vinyl acetate copolymer resin, and the sheet-like base material is a solar cell backsheet.

  In this method for producing a low shrinkage resin film, an encapsulant comprising an ethylene-vinyl acetate copolymer blended with a crosslinking agent, an ultraviolet absorber, a hindered amine light stabilizer, a silane coupling agent, and the like, and a solar cell backsheet Can be manufactured as a solar cell backsheet with a low-shrinkage sealing material.

The method for producing a low shrinkage resin film according to claim 6 is the method for producing a low shrinkage resin film according to claim 5,
The back sheet is characterized in that a fluorine-based resin layer or a weather-resistant polyester resin layer is used as a surface layer, and an aluminum foil or a polyester resin layer with a metal oxide deposited film is provided in an intermediate layer.

  In this method for producing a low shrinkage resin film, the back sheet has a fluorine resin layer or a weather resistant polyester resin layer as a surface layer, and an aluminum foil or a metal oxide vapor deposition film as a barrier layer via an adhesive layer. A low shrinkable resin film having a polyester resin layer as an intermediate layer and further having an easy adhesion layer can be produced.

  According to the method for producing a low shrinkage resin film according to claim 1 of the present invention, since a film-like resin material is stretched and wound on a sheet base material, a product using a sheet base material having a small shrinkage rate is used. The shrinkage at the time of heat bonding after becoming can be reduced. Thereby, shrinkage is small even by reheating at the time of sticking, and a low shrinkage resin film with high heat adhesion is obtained.

  According to the method for producing a low-shrinkage resin film according to claim 2, the film-like resin material on the sheet substrate supported on the conveyance belt is heated and melted together with the conveyance belt. The resin-like resin material can be hardly biased on the sheet base material.

  According to the method for producing a low-shrinkage resin film according to claim 3, the sheet base material is pre-warmed before the film-like resin material is stretched, so that the rapid temperature of the film-like resin material delivered from the die is increased. Lowering can be prevented and a homogeneous resin film can be obtained.

  According to the method for producing a low-shrinkage resin film according to claim 4, after the resin film is formed, the sheet base material is wound inside together with the resin film. By winding up on the front side, occurrence of defects such as wrinkles (cracks) and cracks can be prevented, and a high-quality low-shrinkage resin film can be obtained.

  According to the method for producing a low-shrinkage resin film according to claim 5, the sealing material made of an extruded ethylene-vinyl acetate copolymer is spread on a solar cell backsheet and heated firmly. A back sheet for a solar cell with a low-shrinkage sealing material that is brought into close contact with each other can be manufactured.

  According to the method for producing a low-shrinkage resin film according to claim 6, the back sheet has a fluorine-based resin or a weather-resistant polyester resin layer, which is a light-resistant material, as a surface layer, and an adhesive layer as a barrier layer. The aluminum foil or polyester resin layer with metal oxide vapor deposited film is used as an intermediate layer, and it is further equipped with an easy-adhesion layer, so it is low in intimate contact with the extruded sealing material made of styrene-vinyl acetate copolymer. A solar cell backsheet with a shrinkable sealing material is obtained.

It is a block diagram which represented notionally the manufacturing apparatus used for the manufacturing method of the low shrinkable resin film which concerns on this invention. It is the block diagram which represented notionally the modification of the manufacturing apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The low shrinkage resin film produced in the present embodiment can be suitably used for, for example, a solar cell. As described above, the solar cell is formed of a resin film (for example, EVA film) as a sealing film between a glass substrate as a front surface side transparent protective member and a back sheet as a back surface side protective member. It becomes the structure which sealed the cell for solar cells. That is, a glass substrate, an EVA film for sealing film, a silicon power generation element, an EVA film for sealing film, and a back sheet are laminated in this order, heated and pressurized, and the EVA film is crosslinked and cured to be bonded and integrated. In the thin film type, a power generation element is directly formed on a glass substrate, and then an EVA film for a sealing film and a backsheet are laminated in this order, and heated and pressed to cure and cure the EVA film. Turn into.
In this configuration, the low-shrinkage resin film includes a back sheet from the lower layer, an EVA film for sealing film, and the like.

The low-shrinkage resin film is embossed for pressure-bonding adhesiveness, cushioning properties, and air discharge, and has an uneven surface. The embossing depth is preferably 15 μm or more and 100 μm or less. If the depth is excessively large, air remains during hot pressing with a vacuum laminator, and bubbles may remain in the stacked solar cells, leading to a decrease in power generation efficiency and future failure.
Moreover, the EVA film is blended with a crosslinking agent made of a peroxide and has a crosslinked structure at the time of hot pressing. In addition, a crosslinking aid, a hindered amine light stabilizer, an ultraviolet absorber, a coupling agent, an acid scavenger and the like are blended.

  Here, the back sheet plays a role of maintaining power generation efficiency by protecting the cell and preventing deterioration. That is, the surface of the backsheet is directly exposed outdoors. The back sheet is integrated with the sealing resin surface after sealing the silicon cells arranged under the glass plate with the sealing resin. For this reason, the backsheet has weather resistance (UV light resistance, moisture resistance, heat resistance, salt damage resistance, etc.), water vapor barrier properties, electrical insulation, mechanical properties (tensile strength, elongation, tear strength, etc.), chemical resistance ( Salt water resistance), adhesive integration compatibility with the sealing resin sheet, and the like are required. As the back sheet, fluororesin film, PET (polyethylene terephthalate) resin film with metal oxide vapor deposition film, cyclic olefin, etc. are used as main members, but in addition, composite films that meet various specialized requirements are used. For example, PVF (polyvinyl fluoride) / adhesive / PET / adhesive / EVA, fluororesin coating / PET / adhesive / EVA, fluororesin coating / aluminum foil / Laminated structures such as adhesive / PET / adhesive / EVA, weather-resistant PET / adhesive / silica vapor-deposited PET / adhesive / EVA and the like can be mentioned. Back sheets are sold by Toyo Aluminum, Mitsubishi Aluminum, Lintec, Toppan Printing and Toray.

  The low-shrinkage resin film produced in the present embodiment has a configuration composed of a resin film (such as an EVA film for sealing film) / back sheet. And the objective is to manufacture the low-shrinkage resin film (especially suitable for solar cell use) which laminated | stacked the resin film with low (small) shrinkage property.

Next, the manufacturing apparatus 100 for manufacturing the low shrinkable resin film will be described.
FIG. 1 is a configuration diagram conceptually showing a manufacturing apparatus used in the method for manufacturing a low-shrinkage resin film according to the present invention.
The low-shrinkable resin film manufacturing apparatus 100 includes a backsheet feeding portion 13 that feeds the backsheet 11 with a predetermined tension, and an extrusion molding portion that extrudes the resin material 15 that is a film-like resin material on the backsheet 11 into a film shape. 17, a heating unit 19 that is provided downstream of the extrusion molding unit 17 and melts the resin material 15 on the back sheet 11, and an embossing roller 21 is pressed against the other surface of the resin material 15 provided downstream of the heating unit 19. A pressure roller molding unit 23; a cooling unit 25 that cools the film-like resin material 15 molded on the back sheet together with the back sheet 11, and a product winding unit 27 that winds the resin material 15 and the back sheet 11; Are provided as main constituent requirements.

  The backsheet feed unit 13 is provided with a backsheet roll 31 that can be driven to rotate. In the subsequent heating unit 19, the resin material 15 placed on the back sheet 11 is heated and melted. One surface of the resin material 15, in this embodiment, the lower surface 15 a is bonded to the upper surface of the back sheet 11.

  Between the back sheet feeding unit 13 that supports the back sheet roll 31 and the extrusion molding unit 17, a heater that constitutes a heat processing unit 33 that performs a heat treatment on the fed back sheet 11 is disposed. . That is, the back sheet 11 is preheated before the film-like resin material 15 is spread. The heat processing unit 33 is composed of a pair of upper and lower heaters 33a and 33b sandwiching the back sheet 11 from the front and back sides, for example, constituted by infrared heaters 33a and 33b. The infrared heaters 33a and 33b Preheat from. This preheating temperature is set at ± 25 ° C. with respect to the temperature of the resin material extruded from the extrusion molding portion 17, and preferably within a range of −10 to + 20 ° C. with respect to the extrusion temperature, and is higher than this range. If the temperature is lower than this, the adhesion with the back sheet becomes poor.

  In addition, since the heat treatment unit 33 is provided, a rapid temperature drop of the film-shaped resin material 15 delivered from the extrusion molding unit 17 does not occur. Thereby, a homogeneous resin film from which internal stress has been eliminated can be obtained.

  The extrusion molding unit 17 is provided with a pressing rubber roller 35 and an endless conveying belt 37, and the resin material 15 extruded from the slit-shaped die 39 while the back sheet 11 is fed out from the back sheet feeding unit 13 with a predetermined tension. Is placed on the back sheet 11 and conveyed. The film-like resin material 15 on the back sheet 11 supported on the conveyance belt 37 is heated and melted together with the conveyance belt 37. The film-like resin material 15 is heated and melted on the back sheet 11 supported by the flat conveying belt 37, and the deviation (non-uniform thickness) due to the flow hardly occurs. The thickness of the resin material is substantially determined by the extrusion speed of the resin material 15 from the extrusion molding unit 17, the rotation speed of the roller 35 and the conveyor belt 37, and the gap length.

  The heating unit 19 heats the back sheet 11 on which the resin material 15 is placed on the upper surface together with the transport belt 37. The heating unit 19 is provided with heating means 19 a and 19 b such as an infrared heater, a halogen heater, or an electric heater on the upper and lower surfaces sandwiching the conveyance belt 37 and the back sheet 11. The heating means 19 a and 19 b are resin on the back sheet 11. The material 15 is melted. As described above, the resin material 15 placed on the back sheet 11 is heated and melted by the heating unit 19, so that one surface 15 a is welded to the back sheet 11.

  An embossing roller 21 is provided in the pressure roller molding unit 23 provided at the subsequent stage of the heating unit 19, and the embossing roller 21 forms embossing on the outer peripheral surface. The softened resin material 15 sent from the heating unit 19 is cooled while one surface 15 a is pressed by the rear roller 43 of the transport belt 37 and is pressed by the embossing roller 21. Thereby, the emboss of the embossing roller 21 is pressure-transferred to the other surface of the soft resin material 15 that has passed through the heating unit 19, in this embodiment, the upper surface 15 b.

  The cooling unit 25 is provided with a plurality of transport rollers 45 for cooling and transporting the resin material 15 subsequent to the cooling by the contact of the embossing roller 21 on which the emboss is formed. The cooling unit 25 is provided with a cooling fan (not shown), and the resin material 15 is cooled and solidified by these cooling means to form a resin film 47. That is, the low-shrinkage resin film 49 in which the back sheet 11 and the resin film 47 are integrally laminated is obtained. Moreover, the cooling method can arrange | position not only a fan but a cooling roll, and can also cool.

  A take-up roller 51 of the product take-up unit 27 is provided at the subsequent stage of the cooling unit 25, and the take-up roller 51 takes up the low-shrinkage resin film 49. The resin material 15 is in a state of being placed on the back sheet 11, and the tension is applied only to the back sheet 11 and the conveyance is performed. Therefore, since no physical pressure is applied to the resin material 15, the orientation of the polymer does not occur, and internal distortion hardly occurs. In addition, there is no directionality in strength, optical characteristics, and the like.

  At this time, the low-shrinkage resin film 49 is wound together with the resin film 47 with the back sheet 11 inside. When the resin film 47 rich in stretchability is wound up on the front side, problems such as wrinkles (wrinkles) when the backsheet 11 having a relatively small stretch rate is wound on the surface are less likely to occur. As a result, a high-quality low-shrink resin film 49 can be obtained. On the other hand, when the back sheet 11 is wound outside and wound together with the resin film 47, wrinkles are likely to occur at the initial stage of winding and cause the yield to deteriorate.

  As described above, in the manufacturing apparatus 100, the resin material 15 is placed on the back sheet 11 that is fed from the back sheet feeding unit 13 with a predetermined tension, is heated and melted, and is made into a product by the pressure roller molding unit 23. After the elongation in the softened state no longer occurs, the resin film 47 is taken up together with the back sheet 11, and the low-shrinkage resin film 49, which is a product, is taken up. Therefore, in the manufacturing stage, the sheet is placed on the back sheet 11 between the extrusion molding portion 17 and the product winding portion 27, and no tension is applied to the film-like resin material 15.

Next, the manufacturing method of the low shrinkable resin film using the manufacturing apparatus 100 will be described.
In the production of the low-shrinkage resin film 49 using the production apparatus 100, the back sheet 11 is drawn out with a predetermined tension, and the resin material 15 melted by being heated to about 90 ° C. is formed into a film from the die 39 to form the back sheet. 11 Extrude on top. The film-shaped resin material 15 is heated to about 100 ° C. together with the back sheet 11 and melted on the back sheet 11. That is, the back sheet 11 supports the resin material 15 that is melted by heating. By this heating, the internal strain (internal stress) of the resin material 15 is eliminated. In addition, this heating temperature shall be +/- 25 degree of extrusion temperature, Preferably, it shall be 80-110 degreeC.

  Embossing is performed while pressing the other surface 15b with the embossing roller 21 on which the embossing is formed. At the same time, the back sheet 11 is pressed against one surface 15a. After completion of cooling, the film-shaped resin material 15 is formed on the back sheet 11 into the resin film 47. That is, the low shrinkable resin film 49 in which the resin film 47 is integrally laminated on the back sheet 11 is obtained. The low-shrinkage resin film 49 is wound up so that the back sheet 11 is on the inside, and the manufacturing is finished.

  In this manufacturing method, the back sheet 11 having a relatively small shrinkage rate is used, and shrinkage at the time of heat bonding after becoming a product is reduced. Since the heat melting treatment is performed on the back sheet 11, the distortion at the time of molding is reset (internal stress is removed), and the shrinkage at the time of heat bonding after becoming a product is reduced. Production cost and product cost are greatly reduced by using the sheet base material (back sheet 11), which is a component in the next process (solar cell production), rather than recycling using paper as a support. It becomes possible.

  Therefore, according to the manufacturing method of the low shrinkage resin film described above, since the film-like resin material 15 is stretched and wound on the back sheet 11, the back sheet 11 having a small shrinkage rate is used to obtain a product. The shrinkage at the time of heat bonding can be reduced. That is, from the manufacturing stage, the backsheet 11 is already used for integral molding, thereby simplifying the interlayer bonding process and making it difficult to accumulate internal strain. Thereby, the shrinkage is small even by reheating at the time of sticking, and the low shrinkage resin film 49 having high heat adhesion is obtained.

  In addition, the low shrinkage resin film 49 obtained by this production method has the following excellent points. That is, the circuit is not damaged due to shrinkage deformation or the like particularly when it is laminated with a circuit such as a solar cell. In addition, when the product using the low shrinkage resin film 49 is manufactured, the back surface of the solar cell is configured by an easy sticking operation without taking a large cut and set in consideration of the conventional shrinkage distortion. Can be constructed.

  The low shrinkage resin film 49 is a sealing material film for a solar cell mainly composed of a ternary polymerization crosslinked product of a crosslinking aid such as an ethylene-vinyl acetate copolymer or ethylene-vinyl acetate-triallyl isocyanurate, It can be set as the solar cell sealing material film | membrane previously bonded with the surface protective layer of a solar cell module.

  Further, according to the low shrinkage resin film 49, since the resin film 47 as the sealing material is integrated with the back sheet 11 itself as the back surface protection sheet, the conventional back surface protection sheet and the sealing material are used twice. Lay-up can be reduced at a time and man-hours can be reduced.

FIG. 2 is a configuration diagram conceptually showing a modification of the manufacturing apparatus shown in FIG.
In the above-described embodiment, the example in which the conveyance belt 37 is used for conveyance in the heating unit 19 has been described. However, as the conveyance unit in the heating unit 19, a calendar using a plurality of calendar sheets and calendar rolls is also used. You may use the press manufacturing method and the conveyance means by the modification shown in FIG. The conveying means according to this modification is pressed by the main roller 34 pressed by the pressing rubber roller 35, the pair of support rollers 37Aa and 37Ab for supporting the back sheet 11 on the upstream and downstream sides of the heating means 19b, and the embossing roller 21. And a sandwiching roller 38. According to the manufacturing apparatus 100 </ b> A according to this modification, the heating and conveying means can have a simple structure as compared with the manufacturing apparatus 100 using the conveying belt 37.

  Further, the low shrinkable resin film 49 on which the resin film 47 laminated on the back sheet 11 becomes the low shrinkage side (the surface to be bonded to which the embossing is applied) is used for making a module circuit of a crystalline or thin film solar cell. However, it is preferable that damage, breakage, and wiring disconnection do not occur during the lamination process.

  Further, the back sheet 11 may further stabilize the performance of the back protective sheet by further heat-welding and laminating an EVA adhesive resin film on the inner surface of the aluminum foil or the metal oxide discontinuous layer. Good.

Next, as an example manufactured by the same manufacturing method using a manufacturing apparatus having the same configuration as the configuration according to the above embodiment, a low-shrinkage resin film containing 33% of vinyl acetate, and the amount of vinyl acetate As a comparative example, two examples of a resin film containing 33% vinyl acetate and a resin film containing 28% vinyl acetate were used as comparative examples.
Regarding the four examples of these two examples of low shrinkage resin films and the two examples of comparative examples of resin films, the shrinkage by heating will be compared, and the results of the adhesion to the back sheet and the embossed state will be described.
In addition, these comparative examples are the manufacturing methods which showed what carried out embossing without laminating | stacking resin on a back sheet | seat without performing preheating with respect to the resin raw material after extrusion molding, and heating and melting.

Test method 1) Heat shrinkage rate Each of the four laminated resin films cut and molded in a 14 cm square was marked with 10 cm in the winding direction, and heated in a 90 ° C. oven for 1 hour to measure the shrinkage rate. The film in the oven was heated on an aluminum plate with talc so that it could shrink freely.
2) Adhesiveness with the backsheet A part of the backsheet and the film that had been partially peeled off was cut into a 25 mm-wide strip, and a peel test was performed at a rate of 200 mm / min with an autograph. Those having peel strength were regarded as acceptable.
When the peel strength is low, the back sheet and film peel off during the process and air enters, so when integrated as a module, the air may remain and cause a decrease in yield. Moreover, when the thing which peeled occurs, the part which peeled will produce the hump by the slack of winding, and the smoothness of a product will be impaired. In that case, it is difficult to lay up in the module manufacturing process, and there is a demerit that takes time for positioning.
3) Embossability The surface roughness of the embossing roll surface was previously collected with a silicone mold, and the arithmetic average roughness (Ra) was measured. With respect to this value, the film that was created this time was accepted as a transfer of the embossed shape assumed to have an arithmetic average roughness (Ra) value of 80% or more in surface observation with a laser microscope.
The measurement results are shown in Table 1.

2 of vapor-deposited PET-based backsheet (product name: BS-W250-S-FA20-Le) manufactured by Toyo Aluminum Co., Ltd. and aluminum foil-based backsheet (product name: BS-Le-B50P188-Al20 manufactured by Toyo Aluminum Co., Ltd.) Example 1 in which embossing was performed by heating and melting about 100 ° C. together with a back sheet, which was obtained by extruding a melted EVA resin in a film form from a die, using a seed back sheet, respectively, while being drawn out at a predetermined tension. 2 and 2, it was confirmed that the shrinkage rate was 1% or less, which was significantly smaller than 4.0% and 3.2% of Comparative Examples 1 and 2. Further, curling (resin surface inside) occurred due to shrinkage of EVA resin.
Further, the adhesion to the back sheet and the embossing workability are also in an adhesive state due to material breakage in both examples, and the embossing reproducibility is 88 for the arithmetic average roughness (Ra) of the surface shape of the embossing roll. %, Example 2 was confirmed to have a high reproducibility of 92%, but in Comparative Examples 1 and 2, a partial peel confirmation and a peel strength of 200 g / 25 mm or less were observed.
In Comparative Example 2, the emboss reproducibility was 71%, and the emboss roll shape reproducibility was not obtained.

11 ... Sheet base material (back sheet)
DESCRIPTION OF SYMBOLS 15 ... Film-form resin material for sealing films 21 ... Embossing roller 37 ... Conveyor belt 39 ... Die 47 ... Resin film

Claims (6)

The film-like resin material for the sealing film that is extruded from the die is spread on the sheet base that is sent out,
Heating the film-like resin material together with the sheet base material to melt on the sheet base material,
After the film-like resin material on the sheet base material is pressurized with an embossing roller and cooled, a resin film laminated integrally with the sheet base material is formed,
A method for producing a low shrinkage resin film, comprising winding the resin film together with the sheet base material. A method for producing a low shrinkage resin film according to claim 1,
The sheet base material that is sent out is supported on an endless conveyor belt,
A method for producing a low shrinkage resin film, comprising heating and melting the film-like resin material on the sheet base material supported on the conveyor belt together with the conveyor belt. A method for producing a low shrinkage resin film according to claim 1 or 2,
A method for producing a low-shrinkage resin film, wherein the sheet base material is preheated before the film-like resin material is stretched. A method for producing a low shrinkage resin film according to any one of claims 1, 2, and 3,
After forming the said resin film, it winds with the said resin film with the said sheet | seat base material inside, The manufacturing method of the low shrinkable resin film characterized by the above-mentioned. A method for producing a low-shrinkage resin film according to any one of claims 1, 2, 3, and 4,
The method for producing a low shrinkage resin film, wherein the film-shaped resin material for the sealing film is an ethylene-vinyl acetate copolymer resin, and the sheet-shaped substrate is a back sheet for a solar cell. A method for producing a low shrinkage resin film according to claim 5,
The backsheet has a fluorine resin layer or a weather resistant polyester resin layer as a surface layer, and an aluminum foil or a polyester resin layer with a metal oxide deposited film is provided in an intermediate layer. Method.

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