JP2010228440A - Low elasticity resin film, and method and apparatus for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low elasticity resin film which substantially does not expand and contract even by reheating when sticking to other raw material when a solar cell is manufactured. <P>SOLUTION: In the low elasticity resin film 100 which is to be subjected to both sides embossing, one side 15a is embossed by heating a resin raw material 15 extruded in a film-shape on a conveyance belt 11 where embossment is formed, together with the conveyance belt 11, and another side 15b is embossed by pressurizing the resin raw material 15 with a cooling roller 21 where embossment is formed. Thus, both side embossing is carried out. The low elasticity resin film 100 can be obtained by delivering the conveyance belt 11 with embossing performed, extruding the resin raw material 15 onto the conveyance belt 11, heating the film-shaped resin raw material 15 together with the conveyance belt 11, subjecting the film to embossing together with the one side 15a while pressurizing the film from another side 15b with the cooling roller 21, separating the film from the conveyance belt 11 after finish of cooling and then separately winding up only the low elasticity resin film 100 with both sides embossed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a low stretch resin film, a manufacturing method thereof, and a manufacturing apparatus.

  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. In the T-die molding method, the molten resin is extruded onto the release paper from the T-die, pulled together with the release paper with a pressure roller, and formed into a desired thickness by increasing the extrusion speed at the time of molding, and simultaneously cooled. Then, it is wound up while being peeled off from the release paper (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. In general, a solar cell has a configuration in which solar cell cells such as silicon power generation elements are sealed between a glass substrate as a front surface side transparent protective member and a back surface side protective member (back cover) with an EVA film sealing film. It is said. In other words, a glass substrate, an EVA film for sealing film, a silicon power generation element, an EVA film for sealing film, and a back cover are laminated in this order, heated and pressurized, and EVA is crosslinked and cured to be bonded and integrated. 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. In this type of resin film, embossing is performed to give unevenness to the surface for the purpose of improving handling properties at the time of manufacturing solar cells and improving heat adhesion by improving air escape.

  When embossing is performed as a resin film, in particular, as one method for producing a double-sided embossed resin film, the release paper 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 was laminated on a glass surface or the like, air was easily removed and the heat adhesiveness could 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. In addition, the winding axis direction, which is the width direction orthogonal to the resin film forming direction, is subjected to an internal strain that shrinks during the production of the resin film. it can.
In a conventional sticking process for manufacturing a solar cell or the like, heat bonding is performed in consideration of a shrinkage rate in order to avoid molding defects. For this reason, when the glass substrate and the resin film are overlapped, a complicated bonding process is required in consideration of cutting and shrinking the resin film longer in the winding direction than the surface area of the glass. Further, when the energization structure is provided as in the above-described solar cell, the circuit forming layer and the resin film are overlapped, so that there is a possibility that the circuit is cut when the contraction amount is large, thereby causing a defect in the product.

  The present invention has been made in view of the above situation, and provides a low-stretch resin film that does not substantially change in dimensions even by heat-adhesion at the time of sticking when manufacturing a solar cell, a manufacturing method thereof, and a manufacturing apparatus. Objective.

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
The low stretch resin film according to claim 1 of the present invention is a low stretch resin film 100 embossed on at least one side,
The resin material 15 extruded in the form of a film on the conveying belt 11 made of an endless belt is heated together with the conveying belt 11 to be in a molten state, and is pressed by the cooling roller 21 on which embossing is formed and embossed. It is characterized by that.

  With this low stretch resin film, the resin material 15 can be melted on the transport belt 11, the internal distortion of the extruded film-shaped resin material can be removed, and the winding tension applied to the transport belt 11 can be removed. The tension applied to the resin material 15 during manufacturing can be greatly reduced. As a result, internal strain (stress) caused by elongation in the winding direction is not accumulated.

  The low stretchable resin film according to claim 2 is the low stretchable resin film according to claim 1, wherein an emboss is formed on the transport belt 11.

  According to this low stretchable resin film, both sides are embossed by the conveyor belt 11 and the cooling roller 21.

  The low stretchable resin film according to claim 3 is for sealing solar cells.

The method for producing a low stretch resin film according to claim 4 is a method for producing a low stretch resin film that is embossed on at least one side,
The conveyor belt 11 made of an endless belt is wound and driven,
The resin material 15 is formed into a film from the die 39 and extruded onto the conveyor belt 11,
The film-like resin material 15 is heated together with the conveyor belt 11 to be in a molten state on the conveyor belt 11,
By pressing the film-like resin material 15 with the cooling roller 21 on which the emboss is formed, embossing is performed with the embossing of the cooling roller 21,
The film-like resin material 15 is cooled along with the conveyance by the conveyance belt 11,
Only the embossed low-stretch resin film 100 unloaded and separated from the conveyor belt 11 is taken up at the conveyance terminal end 11b of the conveyor belt 11 after the cooling is completed.

  In this method of manufacturing a low stretchable resin film, a conveyor belt 11 that is wound and driven by a predetermined tension is used, and the resin material 15 is melted and embossed so that no tension acts on the upper surface thereof. . Molding is completed while being placed on the conveyor belt 11, and after molding, that is, after elongation in the softened state does not occur, the molding is separated from the conveyor belt 11 and only the product is separately wound.

The method for producing a low stretch resin film according to claim 5 is a method for producing a low stretch resin film according to claim 4,
The conveyor belt 11 is formed with an emboss.
The resin material is extruded onto the emboss.

  In this method for producing a low-stretch resin film, a low-stretch resin film in which embosses are formed on both surfaces together with the emboss of the cooling roller 21 is obtained by embossing the conveyor belt 11.

  The method for producing a low stretchable resin film according to claim 6 is the method for producing a low stretchable resin film according to claim 4 or 5, wherein before the resin material is extruded onto the carry belt 11, the carry belt. 11 is heat-treated.

  In this low stretch resin film manufacturing method, the transport belt 11 can be heated in advance before the resin material is extruded onto the transport belt 11, and the resin material immediately after being extruded is cooled by the transport belt 11. Will not be.

The apparatus for producing a low stretch resin film according to claim 7 is a production apparatus 200 for a low stretch resin film,
A conveyance belt drive unit 13 for winding and driving a conveyance belt 11 made of an endless belt;
An extrusion molding part 17 for extruding the resin material 15 into a film on the conveyor belt 11;
A heating unit 19 provided in a subsequent stage of the extrusion molding unit 17 to bring the resin material 15 on the conveyor belt 11 into a molten state;
A pressure roller molding unit 23 that pressurizes a cooling roller 21 that is provided at a subsequent stage of the heating unit 19 and has an emboss formed on the surface of the resin material 15;
A cooling unit 25 that cools the film-shaped resin material formed on the conveyor belt 11 together with the conveyor belt 11;
A product take-up unit 29 for taking up only the embossed low-stretch resin film 100 unloaded from the transport belt 11 and separated from the transport belt 11;
It is characterized by comprising.

  In this low stretchable resin film manufacturing apparatus, a resin material 15 is placed on a conveyor belt 11 that is wound and driven by a conveyor belt drive unit 13, and the resin material 15 is heated and melted together with the conveyor belt 11 to be pressurized. After being made into a product in the roller molding part 23 and the cooling part 25 and no longer being stretched in the softened state, the transporting direction of the transport belt 11 is switched, and only the resin film 100 that is the product is wound.

The low stretch resin film manufacturing apparatus according to claim 8 is the low stretch resin film manufacturing apparatus 200 according to claim 7,
The conveyor belt 11 is formed with embossing, and a resin material is extruded onto the embossing.

  In this low stretchable resin film manufacturing apparatus, the resin material 15 placed on the conveyor belt 11 is formed with an embossed surface by the embossing formed on the conveyor belt 11, and the cooling roller 21 and the embossed surface are both surfaces. An emboss is formed on the surface.

The low stretch resin film manufacturing apparatus according to claim 9 is the low stretch resin film manufacturing apparatus 200 according to claim 7 or 8,
The heat treatment part 33 which heat-processes in the front | former stage of the said extrusion part 17 with respect to the said conveyance belt 11 which goes to the said extrusion part 17 is characterized by the above-mentioned.

  In this low stretchable resin film manufacturing apparatus, before the resin material is extruded onto the conveyor belt 11, the conveyor belt 11 can be heated in advance by the heat treatment unit 33 and is extruded from the extrusion molding unit 17. The resin material immediately after is not cooled on the conveyor belt 11.

The low stretch resin film manufacturing apparatus according to claim 10 is the low stretch resin film manufacturing apparatus 200A according to any one of claims 7, 8, and 9, wherein
The transport belt 11 includes a heating-side transport belt 11A that transports the resin material 15 from the extrusion molding unit 17 to the pressure roller molding unit 23, and a cooling-side transport belt 11B that transports the resin material 15 after embossing. It is comprised by these.

  In this low stretchable resin film manufacturing apparatus, the heated part is transported by the heating-side transport belt 11A and the cooled part is transported by the cooling-side transport belt 11B. A belt made of a material suitable for each process can be selected and configured.

  According to the low stretchable resin film of the first aspect of the present invention, the resin material extruded in the form of a film on the transport belt is melted on the transport belt, and the embossed cooling roller is formed. Since the resin material is melted on the conveyor belt and the internal distortion of the extruded film-like resin material can be removed, the internal distortion is applied by the winding drive by the conveyor belt. It can be transported in the absence of tension, and the tension applied to the resin material during manufacturing can be reduced. As a result, the molded resin film becomes a product with very small internal strain, and shrinkage due to reheating is substantially eliminated during the production of solar cells, and dimensional accuracy can be improved. Here, “substantially no shrinkage” means that the shrinkage rate of the resin film when reheated is 10% or less. Preferably, the shrinkage rate of the resin film is 8% or less, and more preferably 6% or less.

  According to the low stretchable resin film according to claim 2, the embossing is applied to the transport belt, and the low stretchable resin is embossed on both sides by the transport belt and the embossing of the cooling roller. A film is obtained.

  According to the low stretchable resin film of Claim 3, it is useful for solar cell sealing.

  According to the method for producing a low-stretch resin film according to claim 4, a conveyor belt that is wound and driven by a predetermined tension is used, and the resin material is extruded onto the conveyor belt, so that the film-shaped resin material is transferred to the conveyor belt. By heating and making the resin material in a molten state on the conveyor belt, the internal distortion of the extruded film-like resin material can be removed. Since only the embossed low-stretch resin film is taken up apart from the belt, the resin material can be taken up by using a conveying belt driven by winding so that the tension does not act directly on the upper surface. In other words, the molding is completed while being placed on the conveyor belt, and after the molding, the direction of the conveyor belt is switched and reversed, and only the film-like product is separately wound. This reduces the occurrence of internal distortion of the extruded film-like resin material as in the conventional manufacturing method, or internal distortion due to elongation in the winding direction due to winding by applying tension, that is, low A stretchable resin film can be obtained.

  According to the method for producing a low stretchable resin film according to claim 5, it is possible to obtain a low stretchable resin film in which embossing is formed on both sides together with embossing of the cooling roller by embossing formed on the conveyor belt. Become.

  According to the method for producing a low stretchable resin film according to claim 6, the conveyor belt can be heated in advance before the resin material is extruded onto the conveyor belt, and the resin material immediately after being extruded is conveyed. It is no longer cooled by the belt.

  According to the low stretch resin film manufacturing apparatus according to claim 7, a conveyor belt drive unit that winds and drives the conveyor belt, an extrusion molding unit that extrudes a resin material in a film shape on the conveyor belt, and an extrusion molding unit A heating unit that is provided in the subsequent stage and heats the resin material on the conveyor belt, a pressure roller molding unit that is provided in the subsequent stage of the heating unit and presses the cooling roller against the surface of the resin material, and cools the film-like resin material to be molded A cooling part to be wound and a product take-up part to wind up the embossed low-stretch resin film, so that the resin material is placed on the conveyor belt to be wound and maintained in a heated state. After making the product in the pressure roller molding part, it can be peeled off from the conveyor belt, and only the resin film that is the product can be taken up, that is, the conveyor belt is between the extrusion part and the product take-up part. In the process of forming the resin film from the resin material, the internal distortion of the film-like resin material extruded in a molten state can be removed, and the resin film itself has a tension. Since it can be wound up with almost no application, it is possible to reduce the occurrence of internal strain and to produce a resin film with a low expansion / contraction rate.

  According to the apparatus for producing a low stretchable resin film according to claim 8, since the emboss is formed on the conveyor belt, the emboss can be transferred and molded on the resin material placed on the conveyor belt, Thus, it is possible to obtain a resin film in which embossing is formed on both sides.

  According to the apparatus for producing a low stretch resin film according to claim 9, before the resin material is extruded onto the conveyor belt, the conveyor belt can be preheated in the heat treatment unit, and the extrusion molding unit can The resin material immediately after being extruded is not cooled on the conveyor belt.

  According to the apparatus for producing a low-stretch resin film according to claim 10, since the transport belt is configured as a separate body for the heating-side transport belt and the cooling-side transport belt, heating is performed in the heating section where the heat treatment is performed. It can be configured with a corresponding belt, and a cooling part to be cooled can be configured with a belt that is good for cooling.

It is the block diagram which represented notionally the manufacturing apparatus of the low elastic resin film which concerns on this invention. It is the block diagram which represented notionally the manufacturing apparatus of the low stretchable resin film of other embodiment which concerns on this invention. It is the block diagram which represented notionally the manufacturing apparatus of the low stretchable resin film of other embodiment which concerns on this invention. It is the block diagram which represented notionally the manufacturing apparatus of the low stretchable resin film of other embodiment which concerns on this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a low stretch resin film, a production method thereof, and a production apparatus according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram conceptually showing a low stretch resin film manufacturing apparatus according to the present invention.
The low stretchable resin film 100 is a resin film that is embossed on at least one surface, and the resin material extruded in a film shape on the transport belt is heated together with the transport belt to form a melted state. It is pressed and embossed by the formed cooling roller. The low stretch resin film 100 according to the present embodiment has embossed on both sides, that is, one surface is formed by a conveyor belt on which emboss is formed, and the other surface is on a cooling roller. It is formed by the formed embossing, and is embossed by pressurization with these conveying belts and cooling rollers.

  The resin material is required to be adhered to the conveyor belt, and is, for example, polyvinyl butyral, ethylene-acrylate copolymer, polyvinyl chloride (PVC) in addition to ethylene vinyl acetate copolymer (EVA). Soft vinyl chloride etc. can be used conveniently. The low stretchable resin film 100 is used, for example, as a sealing film for solar cells. As described above, the solar cell has a configuration in which the solar cell is sealed with the sealing film between the glass substrate and the back cover. The solar cell using the low stretchable resin film 100 includes a glass substrate, a low stretchable resin film 100, a silicon power generation element, a low stretchable resin film 100, and a back cover which are laminated in this order, heated and pressurized, and EVA. It is manufactured by cross-linking and curing and integrating.

  For example, the thickness of the low stretchable resin film 100 used as a sealing material for solar cells is generally 200 μm to 1,000 μm. In this case, improvement in handling property and air escape during solar cell production are achieved. By being good, it is embossed for the purpose of improving adhesiveness, and unevenness is imparted to the surface. The depth by embossing (the difference in height between the irregularities) is preferably 15 μm or more and 500 μm or less. This is because if the depth is excessively large, air is entrained during sealing, and air tends to remain between the laminates. Embossing may be performed only on one side of the film or on both sides. When embossing is performed on both sides of the film, the embossing depth on one side is preferably 15 to 300 μm, and the total on both sides is preferably 30 to 600 μm. Moreover, it is preferable that the ratio of the depth by the embossing with respect to the thickness of a low elastic resin film is 5 to 50%. If the ratio is 10% or more, the low stretchable resin film is less likely to cause blocking, and air escape during solar cell production is good. If the said ratio is 50% or less, the intensity | strength of a low-stretchable resin film can be hold | maintained.

  The EVA resin composition as a solar cell encapsulant used in the present invention preferably has a crosslinked structure by blending a crosslinking agent in order to improve physical properties after lamination. As this crosslinking agent, generally, an organic peroxide having a one-hour half-life temperature (decomposition temperature) higher than the melting point of EVA resin and 100 ° C. or higher is used.

  According to the low-stretchable resin film 100, one surface has an internal distortion of the extruded film-like resin material in a molten state with the resin material extruded as a film on the embossed conveyor belt. After removal, it is embossed with the emboss, and the other surface is embossed with pressure applied by the cooling roller on which the emboss is formed, so the resin material is transported on the transport belt with the tension applied to the transport belt. The tension applied to the resin material during manufacturing can be reduced. As a result, it is possible to reduce the internal strain, reduce the shrinkage rate due to reheating such as when manufacturing a solar cell, and improve the dimensional stability. Moreover, since the shrinkage rate is small, molding defects at the time of heat sticking are reduced. When stacking with a circuit or the like, the circuit is not damaged. Furthermore, it is not necessary to cut and set in a large size in consideration of shrinkage distortion as in the conventional case, and the material cost can be greatly reduced.

Next, the manufacturing apparatus 200 for manufacturing the low stretchable resin film 100 will be described.
The manufacturing apparatus 200 for the low stretchable resin film 100 includes a conveyor belt drive unit 13 that winds and drives the conveyor belt 11 made of an endless belt with a predetermined tension, and an extrusion that extrudes the resin material 15 onto the conveyor belt 11 in a film shape. A molding unit 17, a heating unit 19 that is provided downstream of the extrusion molding unit 17 and that melts the resin material 15 on the transport belt 11, and a cooling roller provided on the other surface of the resin material 15 provided downstream of the heating unit 19 A pressure roller molding unit 23 that pressurizes the sheet 21, a cooling unit 25 that cools the film-shaped resin material 15 molded on the conveyance belt 11 together with the conveyance belt 11, and a conveyance belt 11 that is unloaded from the conveyance belt 11. A product take-up portion 29 that takes up the low-stretchable resin film 100 that has been peeled and separated to become a product is provided as a main component.

  The conveyor belt drive unit 13 includes a plurality of main rollers 37 and conveyor rollers 38 that are rotationally driven by a drive source (not shown), and winds and drives the conveyor belt 11 formed of an endless belt. The driving source may transmit a driving force to the pressure roller molding unit 23. In the subsequent heating unit 19, the resin material 15 placed on the transport belt 11 is heated to a molten state. On one surface of the resin material 15, in this embodiment, the lower surface 15 a is embossed and transferred in a subsequent pressurizing step by embossing of the conveyor belt 11. In front of the extrusion molding unit 17, a heater that constitutes a heating processing unit 33 that performs a heating process on the transport belt 11 that is directed to the extrusion molding unit 17 is disposed. The heat processing unit 33 is composed of a pair of heaters 33a and 33b sandwiching the conveyor belt 11 from the front and back, and is composed of, for example, infrared heaters 33a and 33b. The infrared heaters 33a and 33b hold the conveyor belt 11 from the front and back. Heat. In the heat treatment unit 33, the conveyor belt 11 is set to the same temperature as the resin extruded onto the conveyor belt 11. The temperature of the resin material 15 to be heated in the heating unit 19 is set at +60 to −0 ° C. with respect to the melting point of the resin material extruded from the extrusion molding unit 17, and preferably +60 to + 30 ° C. with respect to the melting point. If it is within this range, the internal stress of the extruded film-like resin material can be removed, and if the temperature is higher than this, the decomposition of the organic peroxide that is a crosslinking agent is not preferable, If the temperature is lower than this, removal of internal stress becomes insufficient, such being undesirable.

  In addition, as the material of the transport belt 11, a belt obtained by coating a woven fabric / nonwoven fabric such as glass fiber or heat-resistant resin fiber with a silicone resin or a fluororesin, or a metal belt such as steel or stainless steel may be used.

  The extrusion molding unit 17 is provided with a main roller 37, and the resin material 15 extruded from the slit-shaped die 39 is placed on the conveyance belt 11 while the conveyance belt 11 is fed from the conveyance belt drive unit 13 with a predetermined tension. Place and transport. The thickness of the resin material is determined by the extrusion speed of the resin material 15 from the extrusion molding portion 17 and the rotation speed of the main roller 37.

  The heating unit 19 is provided with a plurality of conveyance rollers 41 that convey the conveyance belt 11 on which the resin material 15 is placed on the upper surface while supporting it from the lower surface. The heating unit 19 is provided with heating means such as an infrared heater, a halogen heater, or an electric heater on the upper and lower surfaces sandwiching the conveyance belt 11. The heating means brings the resin material 15 on the conveyance belt 11 into a molten state. As described above, the embossing of the conveyor belt 11 can be transferred and molded on the one surface 15a by the subsequent pressure by bringing the resin material 15 placed on the conveyor belt 11 into a molten state in the heating unit 19. It becomes.

  The pressure roller molding unit 23 provided at the rear stage of the heating unit 19 is provided with a cooling roller 21, and the cooling roller 21 has an embossed surface on the outer peripheral surface. In the softened resin material 15 sent from the heating unit 19, one surface 15 a is pressed by the pressing roller 43 and pressed by the cooling roller 21. As a result, the emboss of the conveyor belt 11 is transferred to the one surface 15a, and the emboss of the cooling roller 21 is added to the other surface of the soft resin material 15 that has passed through the heating unit 19, that is, the upper surface 15b in this embodiment. Pressure transferred.

  The cooling unit 25 is provided with a plurality of transport rollers 45 for cooling and transporting the resin material 15 following the cooling due to the contact of the cooling roller 21 with the embosses formed thereon. A cooling fan (not shown) may be provided in the cooling unit 25, and the resin material 15 is cooled by these cooling means.

  A pair of pinch rollers 47, 47 are provided at the conveyance end portion, which is the subsequent stage of the cooling unit 25, and the conveyance belt 11 reverses from the pinch rollers 47, 47, travels backward in the direction of the drive unit 13, and turns to be extruded again. Return to part 17. The resin material 15 on the upstream side from the arrangement position of the pinch rollers 47 and 47 is in a state of being placed on the conveyance belt 11, and the tension is applied only to the substantial conveyance belt 11 and the conveyance is performed. Therefore, since no physical force, i.e., tension, is applied to the resin material 15, the orientation of the polymer does not occur, and internal distortion hardly occurs.

  A product take-up roller 51 is provided in the product take-up unit 29, and the product take-up roller 51 takes up only the low stretchable resin film 100 as a product from which the transport belt 11 is separated.

  As described above, in the manufacturing apparatus 200, the resin material 15 is placed on the conveyor belt 11 that is fed with a predetermined tension from the conveyor belt drive unit 13, is heated and melted, and is made into a product by the pressure roller molding unit 23. After that, that is, after the elongation in the softened state does not occur, the conveyor belt 11 is separated and returned, and only the low stretch resin film 100 as a product is wound. Therefore, in the manufacturing stage of the low stretchable resin film 100, it is placed on the transport belt 11 between the extrusion molding portion 17 and the transport end portion (pinch roller 47) 11 b, and the pinch roller 47 and the product take-up portion 29 are placed. Tension will be applied only in between.

Next, the manufacturing method of the low stretchable resin film using the said manufacturing apparatus is demonstrated.
In the manufacture of the low stretch resin film 100 using the manufacturing apparatus 200, the transport belt 11 made of an endless belt subjected to embossing is wound and driven with a predetermined tension, and the molten resin material 15 is transferred from the die 39 to the film. And is extruded onto the conveyor belt 11. By heating the film-shaped resin material 15 together with the transport belt 11 to a molten state, the internal strain (internal stress) of the resin material 15 is eliminated. The temperature of the resin material 15 is set at +60 to −0 ° C. with respect to the melting point, and preferably within the range of +60 to + 30 ° C. of the melting point. If the temperature of the resin material 15 is equal to or higher than the melting point, the resin material 15 can be in a molten state. Moreover, if the temperature of the resin material 15 is melting | fusing point +60 degrees C or less, when a crosslinking agent is mix | blended with this resin material 15, crosslinking will not advance too much.

  The other surface 15b is cooled while being pressed by the cooling roller 21 on which the emboss is formed, and embossing is performed. At the same time, the embossing of the conveyor belt 11 embosses one surface 15a. After the cooling is completed, the conveyor belt 11 is reversed, and only the low-stretch resin film 100 that has been embossed on both sides and is separated from the conveyor belt 11 is separately wound to complete the manufacture.

  In this method for producing a low stretchable resin film, a conveyor belt 11 that is wound and driven by a predetermined tension is used, and the resin material 15 is heated on its upper surface to be in a molten state. After removing the internal distortion, embossing is performed. Molding is completed in a state where it is placed on the conveyor belt 11, and it is taken out without applying tension, and after molding, it is separated from the conveyor belt 11 after no longer stretched in the softened state, and only the product is separately wound. Will be taken.

  Therefore, according to the manufacturing apparatus 200 described above, the conveyance belt drive unit 13 that drives the conveyance belt 11 to wind, the extrusion molding unit 17 that extrudes the resin material 15 on the conveyance belt 11 in a film shape, and the extrusion molding unit 17. A heating unit 19 provided in the subsequent stage for heating and melting the resin material 15 on the conveyor belt 11 and a pressure roller molding for pressing the cooling roller 21 on the other surface 15b of the resin material 15 provided in the subsequent stage of the heating unit 19 Section 23 and a product take-up portion 29 for winding only the low-stretchable resin film 100 that is separated from and separated from the conveyor belt 11, the resin material 15 is placed on the conveyor belt 11 that is driven to wind. After being heated and melted and made into a product by the pressure roller molding unit 23, only the resin film 100 as a product can be wound up from the conveyor belt 11, and this resin film can be wound. Beam 100, from the position of the cooling and solidifying after the pinch rolls 47 and 47 only tensioned only between the product take-up portion 29, to reduce the occurrence of internal strain, capable of producing a resin film of a low expansion ratio.

  Further, according to the method for producing the low stretchable resin film 100, the embossed transport belt 11 is fed out, the resin material 15 is extruded onto the transport belt 11, and the film-shaped resin material 15 is heated together with the transport belt 11. The internal distortion of the extruded film-like resin material can be removed by being in a molten state, and the embossing of the conveyor belt 11 is embossed on one surface 15a, and the other is cooled by the cooling roller 21. After the cooling is completed, the direction of the conveyor belt 11 is switched at the conveyance terminal end 11b, and only the low-stretch resin film 100 that has been embossed on both sides and separated from the conveyor belt 11 is separately provided. Since it is wound up, the conveyor belt 11 driven by winding with a predetermined tension is used, and the tension does not act on the upper surface thereof. The film-like resin material so as to be able 引取Ru. That is, the molding is completed while being placed on the conveyor belt 11, and only the product is separately wound up from the conveyor belt 11 after the molding. Thereby, it is not necessary to generate an internal distortion due to elongation in the winding direction by winding by applying tension, and a resin film having a low expansion / contraction rate can be obtained by these.

  In addition, in the manufacturing apparatus 200 mentioned above, it is set as the structure which can convey continuously the conveyance belt 11 from the position of the extrusion molding part 17 to the position of the product winding-up part 29, and on the conveyance belt 11, it is the resin raw material 15 to the resin film. Although it has been shown as an example in which the product is placed up to 100 products, it is divided by the processing process of the conveyance path, that is, the resin material 15 is subjected to a heat treatment part and a cooling treatment part. The conveyor belt 11 may be configured as a separate body, and may be configured as a heating-side conveyor belt 11A in a portion where heat treatment is performed, and as a cooling-side conveyor belt 11B in a portion where cooling processing after embossing is performed.

  Further, in the above-described embodiment, the extrusion molding unit 17 is disposed directly above the main roller 37, and the resin material 15 extruded right below from the die 39 is dropped onto the transport belt 11 and then transported by the main roller 37. The resin material 15 is sent together with the belt 11 to the heating unit 19 at the subsequent stage. However, as a configuration of the carry-in side 11a of the resin material 15, in addition to such a configuration, as shown in FIG. It is also possible to adopt a configuration in which 39 is set sideways, the resin material 15 is extruded onto the conveying belt 11 on the main roller 37, and immediately enters the heating unit 19 together with the conveying belt 11. With such a configuration of the carry-in side 11a, it is preferable that the temperature of the resin material 15 is not excessively lowered when the resin material 15 pushed out from the die 39 is sent to the heating unit 19. It should be noted that the resin material 15 is not in direct contact with the main roller 37 or the like and the distance to the heating unit 19 is set short, so that the temperature drop between the resin material 15 and the heating unit 19 is minimized. The process in the heating unit 19 is performed. In addition, by arranging a suction device (not shown) between the resin material 15 extruded from the die 39 and the conveyor belt 11, it is possible to improve the adhesion between the resin material 15 and the conveyor belt 11. is there.

FIG. 3 is a configuration diagram conceptually showing a low stretch resin film manufacturing apparatus 200 </ b> A according to another embodiment of the present invention.
The heating-side conveyance belt 11A extends from the position of the extrusion molding unit 17 to the position of the pressure roller molding unit 23, and is placed on the conveyance belt 11A when the resin material 15 is melted by the heating unit 19. It is made up of an endless belt made of a material that is embossed and has heat resistance.

  The cooling side conveyor belt 11B extends from the position of the pressure roller molding part 23 to the position of the pinch rollers 47 and 47 which are the conveyance end parts, and the resin material after embossing the front and back surfaces is supplied to the cooling part 25. It supports the resin material 15 in the cooling process, and is composed of an endless belt made of a metal belt having a good thermal conductivity such as steel or stainless steel so that the cooling can be performed efficiently.

Then, as shown in FIG. 3, the resin material 15 is disposed and configured to be delivered by the heating side conveyance belt 11 </ b> A and the cooling side conveyance belt 11 </ b> B at the position of the pressure roller molding portion 23.
With such a configuration, the heating-side transport belt 11A is made of a heat-resistant material that can withstand the heating of the resin material 15, and the cooling-side transport belt 11B is made of a resin material that has become a film after embossing. It is possible to select a material corresponding to each configuration in which the material is configured mainly for cooling and conveyance.

FIG. 4 is a configuration diagram conceptually showing a low stretch resin film manufacturing apparatus 200 </ b> B according to still another embodiment of the present invention.
In the low stretchable resin film manufacturing apparatus 200 </ b> B, the configuration of the conveyance belt is not limited as long as the heating-side conveyance belt 11 </ b> A is configured, that is, the cooling side is supported by a plurality of rollers 45. Good.
As shown in FIG. 4, the heating side conveyance belt 11 </ b> A is formed from the position of the extrusion molding unit 17 to the position of the pressure roller molding unit 23, and is conveyed when the resin material 15 is melted by the heating unit 19. The belt is placed on the belt 11A and is composed of an endless belt made of a material having heat resistance. As a material of the conveyor belt 11A, embossing for adding peelability and functionality to the surface, such as metal and rubber, may be performed.

  In this embodiment, the main roller 37 and the roller 34 attached to the main roller 37 are constituted by heating rollers, and these rollers 34 and 37 serve as a heat processing unit 33 to heat the transport belt 11A. It is comprised so that the extrusion resin temperature from the extrusion molding part 17 may not fall. In addition, a touch roller 36 serving as an air biting prevention roller is disposed to face the main roller 37. A heating unit 19 is disposed adjacent to the main roller 37 and the touch roller 36.

  In addition, a pressure roller molding unit 23 in which the cooling roller 20 and the embossing cooling roller 21 are arranged to face each other is disposed at the subsequent stage of the heating unit 19, and the softened resin material 15 that has passed through the heating unit 19 is disposed. Embossed. That is, the emboss of the conveyor belt 11A is pressure-transferred to one surface 15a, and the emboss of the emboss cooling roller 21 is pressure-transferred to the other surface (upper surface) 15b. Further, the cooling roller 20 is provided with a take-off roller 22, and the low-stretch resin film 100 that has been embossed on both sides is peeled off from the belt by the take-off roller 22, and cooling and winding are performed at the subsequent stage. .

  By adopting such a configuration, the heating side conveyor belt 11A is made of a heat resistant material that can withstand the heating of the resin material 15 and is embossed on the heating side, and the embossed film shape on the cooling side. It becomes possible to select the material and structure according to each component that is mainly configured to cool and convey the resin material, and internal distortion to the resin material especially in the process part of heating and embossing The resin material in a heated and melted state is supported and molded by a belt so that (internal stress) is eliminated, and after the take-off roller 22, only the cooling and winding processes are performed, and the tension at the product winding unit 29 is applied. Thus, the occurrence of internal strain can be reduced, and a resin film having a low expansion / contraction rate can be obtained.

  Next, the amount of vinyl acetate contained in the low stretch resin film according to the example manufactured by the same manufacturing method using the manufacturing apparatus having the same configuration as that of the above embodiment is 33% and 28%. The results of comparing shrinkage due to heating in one example of a resin film according to a comparative example and two conventional resin films will be described. These comparative examples and conventional examples are only cooled after embossing the resin material after extrusion molding. In the comparative examples, a manufacturing method using a conveyor belt, each conventional example is an old manufacturing method that does not use a belt. It is.

Hereinafter, the resins used in the examples are as follows.
EVA1: ethylene vinyl acetate copolymer (manufactured by The Polyolefin Company, trade name “Cosmothene MA-10”, vinyl acetate content 33 mass%, melting point: 60 ° C.)
EVA2: ethylene vinyl acetate copolymer (manufactured by The Polyolefin Company, trade name “Cosmothene VF-023”, vinyl acetate content 28 mass%, melting point: 69 ° C.)

[Example 1]
EVA1: 100 parts by mass, cross-linking agent (manufactured by NOF, trade name “Perbutyl E”, t-butylperoxy 2-ethylhexyl monocarbonate, 1 hour half-life temperature 119.3 ° C.) 1.0 part by mass, ultraviolet ray Absorbent (BASF, trade name “Uvinul 3008”, 2-hydroxy-4 octoxybenzophenone) 0.2 parts by mass is dry blended with a ribbon blender, melt kneaded with an extruder (uniaxial, caliber 90 mm), slit The resin material 15 was extruded onto the conveyor belt 11 using the manufacturing apparatus shown in FIG. 1 using a shape die (T-die) 39. The temperature of the die 39 was 90 ° C., and the screw rotation speed was 20 rpm. While the extruded resin material 15 was transported by the transport belt 11, the resin material 15 was heated together with the transport belt 11 by a 120 ° C. oven for 30 seconds. At this time, the temperature of the resin material 15 at the outlet of the oven was 100 ° C. Thereafter, the resin material 15 is embossed by the pressure roller molding unit 23, passes through the cooling unit 25, and is transported to the pinch rollers 47 and 47 together with the transport belt 11, and then separated from the transport belt 11 to take up the product. The film was wound around a roller 51 to obtain a low stretch resin film 100. The thickness of the resin film is 600 μm, the embossing is a grained pattern, and the arithmetic average of the emboss depth is 80 μm.

[Example 2]
A low stretch resin film 100 was obtained in the same manner as in Example 1 except that the resin was changed to EVA2.

[Comparative example]
A resin film was obtained in the same manner as in Example 1 except that a manufacturing apparatus in which the heating unit 19 was omitted was used. The temperature of the film was measured immediately before the pressure roller molding part 23.

[Conventional example 1]
The resin material extruded from the die was cooled by a cast roll having an embossed surface formed by a T-die extrusion method, and wound around a product winding roller 51 to obtain a resin film. The film temperature was measured after the cast roll.

[Conventional example 2]
A resin film was used in the same manner as in Example 2 except that a manufacturing apparatus in which the heating unit 19 was omitted was used and release paper (made by Oji Specialty Paper, trade name “N-73GS”) was used instead of the conveyor belt 11. Obtained. The film temperature was measured immediately before the pressure roller molding part 23.

In the test method, a film cut into a 12 cm square was marked with 10 cm in the winding direction, that is, the molding direction, heated in an oven at 90 ° C. for 1 hour, and the shrinkage was measured.
The film in the oven was heated on an aluminum plate with talc so that it could shrink freely.
The measurement results are shown in Table 1.

  In both examples in which the resin material was placed on a conveyor belt that was drawn out with a predetermined tension and driven to heat and heated to maintain a molten state, the shrinkage ratio was 3 to 5, and the comparative example 16. It was confirmed that it was 1/3 or less than 0. Moreover, when compared with the conventional examples 1 and 2 which are the current products, it was confirmed that the shrinkage ratio was reduced to 1/10 to 1/5.

DESCRIPTION OF SYMBOLS 11 ... Conveyance belt 13 ... Conveyance belt drive part 15 ... Resin raw material 15a ... One side 15b ... Other side 17 ... Extrusion molding part 19 ... Heating part 21 ... Cooling roller 23 ... Pressure roller molding part 25 ... Cooling part 29 ... Product winding unit 33 ... Heat treatment unit 39 ... Die 100 ... Low stretch resin film 200 ... Low stretch resin film manufacturing apparatus

Claims (10)

A low stretch resin film embossed on at least one side,
The resin material extruded in the form of a film on a conveyance belt made of an endless belt is heated together with the conveyance belt to be in a molten state, and is embossed by being pressed by a cooling roller having an emboss formed thereon. A low stretch resin film.   2. The low stretchable resin film according to claim 1, wherein an emboss is formed on the conveyor belt.   The low stretchable resin film according to claim 1 or 2, which is used for sealing a solar cell. A method for producing a low stretch resin film embossed on at least one side,
The conveyor belt consisting of an endless belt is wound and driven.
A resin material is formed into a film from a die and extruded onto the conveyor belt,
The film-like resin material is heated together with the conveyor belt to be in a molten state on the conveyor belt,
By pressing the film-like resin material with a cooling roller on which embossing is formed, embossing is performed on the embossing of the cooling roller,
The film-like resin material is cooled along with the conveyance by the conveyance belt,
A method for producing a low-stretch resin film, wherein only the embossed low-stretch resin film unloaded from and separated from the transport belt is separately wound at the transport end portion of the transport belt after cooling is completed. . The conveyor belt is formed with embossing,
The method for producing a low stretch resin film according to claim 4, wherein the resin material is extruded onto the emboss.   The method for producing a low stretchable resin film according to claim 4 or 5, wherein a heat treatment is performed on the conveyor belt before extruding the resin material onto the conveyor belt. An apparatus for producing a low stretch resin film,
A conveyor belt drive unit for winding and driving a conveyor belt made of an endless belt;
An extrusion molding section for extruding a resin material into a film on the conveyor belt;
A heating unit provided at a subsequent stage of the extrusion molding unit to melt the resin material on the conveyor belt;
A pressure roller molding section that is provided in a subsequent stage of the heating section and pressurizes a cooling roller having an emboss formed on the surface of the resin material;
A cooling unit that cools the film-shaped resin material formed on the conveyor belt together with the conveyor belt;
A product take-up portion that takes up only the embossed low-stretch resin film that is unloaded from the conveyor belt and separated from the conveyor belt;
An apparatus for producing a low-stretch resin film, comprising: An apparatus for producing a low stretch resin film according to claim 7,
Embossing is formed in the said conveyance belt, The resin raw material is extruded on this embossing, The manufacturing apparatus of the low elastic resin film characterized by the above-mentioned. An apparatus for producing a low stretchable resin film according to claim 7 or 8,
An apparatus for producing a low-stretch resin film, comprising: a heat treatment unit that performs heat treatment on the conveyor belt toward the extrusion molding unit at a stage preceding the extrusion molding unit. An apparatus for producing a low stretch resin film according to any one of claims 7, 8, and 9,
The conveyance belt is configured by a heating-side conveyance belt that conveys the resin material from the extrusion molding unit to the pressure roller molding unit, and a cooling-side conveyance belt that conveys the resin material after embossing. An apparatus for producing a low stretch resin film.

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