JP2013018206A - Method for manufacturing resin film joined body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a resin film joined body, which does not need a process for making the step difference of parts to be joined small and applying a light absorbent, and suppresses sticking of light absorbent as a foreign matter, and can efficiently join resin film members to each other to simply produce a resin film joined body.SOLUTION: The method for manufacturing the resin film joined body includes a process of butting edge surfaces of the resin film members to each other and joining the surfaces to produce the resin film joined body, wherein a light absorbing member provided with a surface having a high light absorptance with respect to the wavelength of a laser beam to be used and stability in the temperature environment of 300°C is used, the part at which the edge surfaces are butted to each other is brought into contact with the surface, the light absorbing member is irradiated with the laser beam to generate heat, the edge surfaces of the resin film members are thermally welded to each other and the butted part is separated from the light absorbing member to produce the resin film joined body.

Description

  The present invention relates to a method for manufacturing a resin film assembly, and, for example, relates to a method for manufacturing a resin film assembly in which band-shaped resin film members are bonded together to produce a resin film assembly.

  Conventionally, in a case where a strip-shaped resin film member is continuously supplied to a processing machine and processed, the preceding resin film is supplied to supply a new resin film member to the processing machine following the preceding resin film member. Joining the tip portion of a new resin film member to the end portion of the member (so-called splicing) is performed. Moreover, not only in such a case, the manufacturing method of the resin film joined body which joins resin film members at an edge part and produces a resin film joined body is widely implemented (refer patent document 1).

As a method for manufacturing this type of resin film assembly, as shown in FIG. 4A, resin film members 101 and 102 that are transparent to laser light 100R are overlapped with each other via a light absorber 104. A method has been proposed in which the overlapped portion is irradiated with a laser beam 100R to thermally bond the resin film members 101 and 102 together.
As another method, as shown in FIG. 4B, the end portions of the resin film members 101 and 102 that are transmissive to the laser beam 100R are butted together, and the butted portions are light-absorbed. The bonding member 105 coated with the agent 104 is coated so that the light absorber 104 is located at the interface between the resin film members 101 and 102 and the bonding member, and the laser beam 100R is coated on the portion covered with the bonding member 105. Is also known in which the resin film members 101 and 102 and the bonding member 105 are bonded by thermal welding.

Japanese Patent No. 3682620

  However, in these methods, the resin film members are overlapped with each other, or the resin film members and the adhesive member are thermally melted. When transporting the resin film assembly by a so-called roll-to-roll that rolls out the roll of the film assembly from the outside and winds it on another roll, the joint portion (seam, joint member, etc.) When the step (edge) passes through the conveying roller, the roller may be damaged. Further, when the resin film bonded body is wound up in a roll shape, a dent caused by the step may be generated in a peripheral portion of the step, and thus there is a possibility that the product extraction efficiency is deteriorated.

  Therefore, as shown in FIG. 5, the light absorber 104 is applied to the heat generating medium 106, the resin film members 101 and 102 are abutted, and the light absorber 104 is positioned at the interface between the resin film members 101 and 102 and the heat generating medium 106. The abutted portion is covered with the heat generating medium 106, the portion covered with the heat generating medium 106 is irradiated with a laser beam 100R, and only the resin film members 101, 102 are thermally welded to join each other. A method of manufacturing the resin film joined body 107 by peeling the butted portion from the heating medium 106 is conceivable.

  However, in such a method, the light absorbing agent 104 applied to the heat generating medium 106 adheres to the resin film joined body 107 and disappears from the heat generating medium 106 after heat welding. There is a problem that a step of applying the agent 104 is required and the lead time becomes long. In addition, an application device for applying the light absorber 104 is required, which requires an initial cost, and there is also a problem that the device itself for manufacturing the resin film assembly becomes large by the amount of installation. In addition, if the light absorber 104 adheres unintentionally as a foreign substance to a portion other than the portion where the light absorber is to be applied, the product yield may be reduced.

  Therefore, in order to solve these problems, for example, instead of the heat generating medium coated with the light absorber as described above, a light absorbing member formed by forming a light absorbing material into a film shape or the like, for example. A method of using can also be considered. In this method, for example, the light absorbing member is brought into contact with a portion where the two resin film members as described above are abutted, and the light absorbing member is irradiated with a laser beam to thermally weld only the resin film members. Are joined, and the butted portion is peeled off from the light absorbing member to produce a resin film joined body.

  However, in such a method, the light absorption rate of the light absorbing member may be changed by the irradiated laser light, and in such a case, when performing laser welding repeatedly, in order to prevent the quality of the joint portion from varying, Since the laser beam irradiation conditions and the like must be changed each time laser welding is performed, the efficiency is deteriorated. On the other hand, if laser welding is repeatedly performed using the same laser light irradiation conditions, etc., it is necessary to replace the light absorbing member each time laser welding is performed, so that the efficiency is deteriorated as described above.

  In view of the above problems, the present invention makes it possible to efficiently reduce the step of the joining portion, eliminate the need for a step of applying a light absorber, and efficiently prevent the light absorber from adhering as a foreign substance. It is an object of the present invention to provide a method for producing a resin film assembly capable of producing a resin film assembly by joining film members together.

  As a result of intensive research conducted by the inventor on the above problem, the change in the light absorption rate is related to the oxidation of the surface of the light absorbing member due to the influence of heat generated by laser light irradiation, that is, the stability of the surface. Turned out to be. And it discovered that a light absorption member has stability under the temperature environment of 300 degreeC, and can suppress the change of the light absorption rate of the light absorption member by irradiation of a laser beam, and came to complete this invention. .

That is, the method for producing a resin film assembly according to the present invention includes:
A method for producing a resin film assembly, in which the end faces of a resin film member are butted together to form a resin film assembly,
Using a light absorbing member having a surface having a higher light absorption rate than the resin film member with respect to the wavelength of the laser light to be used and having stability in a temperature environment of 300 ° C.,
The portions where the end faces are brought into contact with each other are brought into contact with the surface, and the light absorbing member is irradiated with laser light to generate heat, thereby heat-welding the end faces of the resin film member, and from the light absorbing member The butted portion is peeled off to form a resin film joined body.

  Here, in the present invention, “having stability under a temperature environment of 300 ° C.” means “not oxidizing under a temperature environment of 300 ° C.”.

According to this method for producing a resin film assembly, the light absorbing member absorbs laser light and generates heat, so that the end faces of the resin film member are thermally welded to each other, thereby providing the following effects.
That is, since the resin film members are joined to each other only through the end faces, a resin film joined body with few steps can be produced at the joined portion. And since the level | step difference of a junction part can be reduced in this way, when the resin film conjugate | zygote is conveyed using the roller for conveyance, damage etc. of the said roller for conveyance can be prevented. Further, when the resin film bonded body is wound up, it becomes difficult to produce dents, and the efficiency of taking out the product can be increased.
Moreover, a resin film joined body can be produced, without requiring the process of apply | coating a light absorber. Therefore, the lead time can be shortened by the process of applying the light absorber. Moreover, the cost of coating equipment and the material cost of expensive light absorbers can be suppressed. Furthermore, since the foreign substance resulting from a light absorber does not arise, a product yield can be improved.
Furthermore, since the surface has stability under a temperature environment of 300 ° C., it is possible to prevent a change in light absorption rate on the surface of the light absorbing member due to the influence of heat generated by laser light irradiation. Laser welding can be performed without changing the laser light irradiation conditions and the like each time welding is performed. Further, it is possible to repeatedly perform laser welding using the same laser light irradiation conditions without replacing the light absorbing member. Thereby, manufacture of a resin film joined body becomes efficient.
Therefore, according to the manufacturing method of such a resin film joined body, the step of the joining portion is reduced, the step of applying the light absorber is not required, and further, the light absorber is prevented from adhering as a foreign substance, and the efficiency is increased. In addition, the resin film members can be bonded together to efficiently manufacture the resin film bonded body.

  In the said manufacturing method, it is preferable that the said light absorption member has a light absorption rate of 10% or more with respect to the wavelength of the said laser beam.

  Thus, when the light absorbing member has the light absorption rate of 10% or more, the resin film members can be more reliably heat-welded more reliably.

  In the manufacturing method, the light absorbing member preferably contains diamond-like carbon, glassy carbon, or carbon graphite.

  Thus, when the light absorbing member contains diamond-like carbon, glassy carbon, or carbon graphite, it becomes possible to more efficiently absorb the laser light and generate heat. Further, the surface is likely to have stability under a temperature environment of 300 ° C.

  In the said manufacturing method, it is preferable that the said laser beam has a wavelength of 800 nm or more and 2000 nm or less.

  Thus, when the wavelength of the laser beam is in the near-infrared region, the energy conversion efficiency to heat is good, and a stable laser beam is easily obtained.

  In the said manufacturing method, it is preferable that the said resin film member has a thickness of 150 micrometers or less.

  As described above, since the resin film member has a thickness of 150 μm or less, the heat generated by the laser beam irradiation is more easily transmitted over the entire thickness direction of the resin film member, so that the resin film member can be sufficiently melted by heat. It becomes easy.

  In the said manufacturing method, it is preferable that the said resin film member contains the thermoplastic resin which has 300 degreeC or less melting | fusing point or a glass transition point.

  Thus, when the resin film member contains a thermoplastic resin having a melting point or glass transition point of 300 ° C. or lower, the resin film member can be easily melted.

  In the manufacturing method, the resin film member may contain any one or more of triacetyl cellulose resin, polyethylene terephthalate resin, polycarbonate resin, polymethyl methacrylate resin, cycloolefin polymer, norbornene resin, or polyvinyl alcohol resin. preferable.

  Since these resins all have a melting point or glass transition point of 300 ° C. or lower, the resin film member can be easily melted as described above.

  As described above, according to the present invention, it is possible to reduce the level difference of the joining portion, without requiring a step of applying a light absorber, and further while efficiently suppressing the light absorber from adhering as a foreign substance, A resin film joined body can be manufactured.

The schematic process drawing which showed the end surface formation process and the matching process of the manufacturing method of the resin film conjugate | zygote which concerns on one Embodiment. The figure which showed the joining process of the manufacturing method of the resin film conjugate | zygote which concerns on one Embodiment. The figure which showed the process of winding up the resin film conjugate | zygote which concerns on this embodiment in roll shape. The figure which showed the manufacturing method of the resin film conjugate | zygote using the laser beam of a prior art. The figure which showed the manufacturing method of the resin film assembly using the laser beam which can be considered.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The method for producing a resin film assembly of the present embodiment is a method for producing a resin film assembly in which the end faces of the resin film members are brought into contact with each other and bonded to each other. Using a light absorbing member having a surface having a light absorption rate higher than that of the resin film member and having stability under a temperature environment of 300 ° C., the portion where the end faces are abutted against each other is brought into contact with the surface, By irradiating the light absorbing member with laser light to generate heat, the end faces of the resin film member are thermally welded, and the butted portion is peeled off from the light absorbing member to form a resin film assembly. is there.

  Specifically, in the method of manufacturing the resin film assembly of the present embodiment, the end portion of the first resin film member and the end portion of the second resin film member are overlapped, and both the overlapped end portions are simultaneously applied. By cutting, an end face forming process for forming cut ends corresponding to each other at these end parts, one end face formed in the end face forming process and the other end face are abutted, and the abutted part is light-absorbed The abutting step for contacting the surface of the member, the step of fixing the abutted portion together with the light absorbing member, and heating the end surfaces of the resin film members by applying laser light to the light absorbing member to generate heat. Welding, peeling off the butted portion from the light absorbing member, and carrying out a joining step to make a resin film joined body.

The first resin film member and the second resin film member described above are generally those containing the same kind of thermoplastic resin, but are not limited to the same kind and are thermally welded to each other. Different materials may be used as long as they are possible. For example, different types of compatible thermoplastic resins may be used.
Moreover, such a thermoplastic resin preferably has a melting point of 300 ° C. or lower, and more preferably has a melting point of 250 ° C. or lower. When the thermoplastic resin has a melting point of 300 ° C. or less, the resin film member is easily melted.
Further, when the above-described thermoplastic resin is an amorphous thermoplastic resin having no melting point, the thermoplastic resin preferably has a glass transition point of 300 ° C. or less, and 250 ° C. It is more preferable to have the following glass transition point. When the thermoplastic resin has a glass transition point of 300 ° C. or lower, the resin film member is easily melted.
Thus, when the thermoplastic resin has a melting point or glass transition point of 300 ° C. or lower, the resin film member is easily melted.

Examples of such thermoplastic resins include polycarbonate resins, polyvinyl alcohol resins, polyethylene resins, polypropylene resins, polyethylene terephthalate resins, polyvinyl chloride resins, thermoplastic polyimide resins, triacetyl cellulose resins, polymethyl methacrylate resins, and cycloolefins. Polymer, norbornene resin, polyoxymethylene resin, polyetheretherketone resin, polyetherimide resin, polyamideimide resin, polybutadiene resin, polyurethane resin, polystyrene resin, polymethylpentene resin, polyamide resin, polyacetal resin, polybutylene terephthalate resin, Examples thereof include ethylene vinyl acetate resin. Moreover, any one of these may be used as the thermoplastic resin, or two or more may be mixed and used.
The thermoplastic resin is preferably at least one of these resins among triacetyl cellulose resin, polyethylene terephthalate resin, polycarbonate resin, polymethyl methacrylate resin, cycloolefin polymer, norbornene resin or polyvinyl alcohol resin. . Since these resins all have a melting point or glass transition point of 300 ° C., the resin film member is easily melted by heat as described above.

Further, the resin film member may be a single layer or may be a laminate of a plurality of layers, and is not particularly limited as long as at least one layer is made of a thermoplastic resin.
Examples of the resin film member on which a plurality of layers are laminated include those in which a base material layer and a protective film layer with an adhesive are laminated.
In addition, when heat-welding such a resin film member in which a plurality of layers are laminated, each layer may be temporarily peeled and heat-welded for each layer, or heat-welded with the layers being laminated. May be. For example, if the compatibility between the base material layer and the protective film layer is poor and the mixed layers are not formed even if both layers are heat-melted, even if the resin film members laminated with both layers are heat-sealed, It is possible to peel the base material layer and the protective film layer after welding.

Furthermore, the thickness of the resin film member is preferably 150 μm or less, and more preferably 100 μm or less. When the thickness is 150 μm or less, the thermal energy generated from the light absorbing member due to the irradiation of the laser beam is more easily transmitted across the entire thickness direction (depth direction) of the resin film member, and the resin film members are more sufficiently connected to each other. It becomes easy to heat weld.
On the other hand, the thickness of the resin film member is preferably 5 μm or more, and more preferably 20 μm or more. When the thickness is 5 μm or more, the bonding strength of the resin film bonded body can be further sufficiently increased by the thickness.

Further, the resin film member preferably has a light transmittance of 30% or more with respect to the laser light, and more preferably 50% or more.
The “light transmittance” is a value represented by “100% −“ light absorption rate (%) ”” and obtained by the following formula (1).
Transmitted light intensity ÷ incident light intensity × 100% (1)
(However, “incident light intensity” is determined by “irradiation light intensity−surface reflected light intensity”.)

  In the said end surface formation process, as shown to Fig.1 (a), both the resin film members 10 and 20 in the state which accumulated the edge part of the 1st resin film member 10 and the edge part of the 2nd resin film member 20 were piled up. Are fixedly arranged, and by cutting a general resin film member 10 or 20 using a cutting tool 40 or the like, both of the overlapped end portions are cut at a time so that these end portions correspond to end faces. Form a cut. As a fixing method of the resin film members 10 and 20, for example, a general fixing method such as a method of fixing the resin film members 10 and 20 using an adsorption device 30 or the like that fixes the resin film members 10 and 20 by adsorption can be used.

  And in the said end surface formation process, as shown in FIG.1 (b), the cut end 10a of the 1st resin film member and the cut end 20a of the 2nd resin film member are transferred to a cut end collection | recovery part (not shown).

  In the manufacturing method of the resin film assembly of the present embodiment, by performing the end surface forming step, in the abutting step, the abutted end surfaces are brought into a substantially parallel state so that one end surface and the other end surface are butted together. Can.

  In the abutting step, as shown in FIG. 1C, the resin film members 10 and 20 are fixed by the suction device 30 while the resin film members 10 and 20 are placed on the stage 50 (the stage 50 is shown in FIG. 2). The suction device 30 is finely adjusted as necessary to make a desired gap, and one end face formed in the end face forming step is brought into contact with the other end face.

  Moreover, in the said butting | matching process, the length of the gap between the resin film members 10 and 20 (the largest thing among the length of the direction perpendicular | vertical to the end surface in the clearance gap between the resin film members 10 and 20) is used as the resin film member. The thickness is preferably less than half the thickness of the resin film member, more preferably less than half the thickness of the resin film member, and particularly preferably less than 1/3 the thickness of the resin film member. In the manufacturing method of the resin film assembly of the present embodiment, the resin of the resin film member is caused by the thermal energy generated from the light absorbing member by the irradiation of the laser light by making the length of the gap less than the thickness of the resin film member. By being melted and fluidized, the gap can be filled and a good bonding state and strength can be obtained.

  Further, in the matching step, the gap length is measured using a gap monitor (not shown) equipped with a camera (not shown) or the like, and the gap is measured by an irregular factor (for example, an earthquake or the like). If the length of the gap has exceeded the specified value, the length of the gap is specified by moving and finely adjusting at least one of the suction devices 30 that fix the resin film members 10 and 20. You may make it smaller than a value.

In the joining step, as shown in FIG. 2, the butted portion is placed on a stage 50 arranged so that the light absorbing member 50a comes into contact with the butted portion with a pressure member 60 made of transparent glass. The pressed part is brought into contact with the light absorbing member 50a while being pressed and fixed. And in the state fixed in this way, by irradiating the light absorption member 50a with the laser beam R and generating heat, the end surfaces of the resin film members 10 and 20 are thermally welded to each other, and the light absorption member The abutted portion is peeled off from 50a, and a resin film joined body 80 is produced.
In addition, as a method of bringing the abutted portion into contact with the light absorbing member 50a, a method of placing the abutted portion on the upper surface of the light absorbing member 50a and bringing it into contact (see FIG. 2), For example, a method (not shown) in which the butted portion is pressed against the lower surface of the light absorbing member 50a and brought into contact therewith.

Pressurizing pressure strength of the pressure-圧固scheduled is a portion where the laser beam R is irradiated, the abutted portion is preferably 0.5~100kgf / cm ^2, is 10~70kgf / cm ² More preferably.

  The shape of the pressurizing member 60 is not particularly limited as long as a load is applied to the abutted portion. For example, a flat plate, a cylinder, or a spherical shape can be used.

  The thickness of the pressure member 60 is preferably 3 mm or more and less than 30 mm, and more preferably 5 mm or more and less than 20 mm. In the joining step, by using the pressure member 60 having a thickness of 3 mm or more, the pressure member 60 itself is hardly distorted during pressure fixation, and good pressure fixation can be achieved. Moreover, in the said joining process, since the laser beam R becomes difficult to be lost when the laser beam R permeate | transmits the pressurization member 60 by using the pressurization member 60 whose thickness is less than 30 mm, the resin film members 10 and 20 It can be made easy to heat-weld each other efficiently.

  Examples of the transparent glass constituting the pressure member 60 include a hard borosilicate glass marketed under the name of “Tempax”, a borosilicate glass marketed under the name of “Pyrex”, and a product of “Vycor”. 96% silica glass marketed by name, barium borosilicate glass marketed as "D263", non-alkali glass marketed as "OA10", aluminoborosilicate glass marketed under the brand name "AF45" Quartz, alkali-free glass, lead alkali glass, soda-lime glass, quartz glass and the like can be mentioned.

  From the viewpoint that the laser beam R is less likely to be lost when the laser beam R passes through the pressure member 60 and the resin film members 10 and 20 are easily heat-welded with each other. It is preferable that the light transmittance is higher than 50% with respect to the wavelength of light, and it is more preferable that the light transmittance is higher than 70%.

  In the above bonding step, from the viewpoint of uniformly pressing the large area of the butted portion with the pressure member 60 and performing good bonding over the entire area, between the butted portion and the pressure member 60, An interphase member 70 that is transmissive to the laser light R and superior in cushioning properties to the pressurizing member 60 may be interposed.

  Examples of the material of the interphase member 70 include rubber materials (for example, silicon rubber and urethane rubber) and resin materials (for example, polyethylene).

  Further, the interphase member 70 may be a single layer or may be a laminate of a plurality of layers.

  Further, the interphase member 70 preferably has a light transmittance higher than 50% with respect to the wavelength of the laser light R to be used, and further has a light transmittance higher than 70%. preferable.

  Furthermore, the thickness of the interphase member 70 is preferably 50 μm or more and less than 5 mm, and more preferably 1 mm or more and less than 3 mm. In the joining step, by using the interphase member 70 having a thickness of 50 μm or more, the force generated by the pressurization can be more sufficiently dispersed. Thereby, the large area of the abutted part can be more uniformly pressed by the pressing member 60, and more excellent bonding can be performed over the entire area. Further, by using the interphase member 70 having a thickness of less than 5 mm, the laser beam R is not easily lost when the laser beam R passes through the interphase member 70, and the resin film members 10 and 20 are easily heat-sealed efficiently. Become.

The laser beam R used in the bonding step plays a role of causing the light absorbing member 50a to generate heat, and the type of laser is not particularly limited as long as the effects of the present invention are not impaired. The laser is preferably a solid-state laser such as a semiconductor laser, a fiber laser, a femtosecond laser, or a YAG laser, from the viewpoint of having light in the visible light region or infrared region that has a wavelength with good conversion efficiency of energy into heat. A gas laser such as a CO ₂ laser. Among these, a semiconductor laser and a fiber laser are more preferable from the viewpoint that an inexpensive laser beam having a spatially uniform in-plane intensity can be easily obtained. In a process that goes through a multiphoton absorption process such as a process using a femtosecond laser or a picosecond laser, the focal position and input energy of the laser are optimized regardless of the transparency of the resin film members 10 and 20 with respect to the laser wavelength. This makes it possible to achieve bonding. Further, from the viewpoint of promoting thermal melting while avoiding the decomposition of the resin film members 10 and 20, a continuous wave CW laser is more preferable than a pulse laser that instantaneously applies high energy.

Regarding the laser, the output (power), power density, beam shape, number of irradiations, scanning speed, irradiation time, integrated irradiation amount, and the like are optical characteristics such as the light absorption rate of the resin film members 10 and 20 and the light absorbing member 50a. What is necessary is just to set suitably by differences, such as thermal characteristics, such as melting | fusing point and a glass transition point (Tg).
The power density of the laser to be irradiated is 50 W from the viewpoint of obtaining a strong joint by thermally melting and fluidizing the abutted portions of the resin film members 10 and 20 with the laser light R through the light absorbing member. / cm ² ~3,000W / cm ^2, more preferably from ^{200W / cm 2 ~1,500W / cm 2} , 250W / cm 2 ~1,000W / cm 2 is particularly preferred.
As the integrated irradiation dose, from the same viewpoint, preferably ^{10J / cm 2 ~300J / cm 2} , more preferably ^{20J / cm 2 ~150J / cm 2} , particularly preferably 30J / cm ² ~100J / cm ² .

In the bonding step, the light absorbing member 50a is irradiated with the laser light R transmitted through the resin film members 10 and 20 by irradiating the laser light R along the portion where the resin film members 10 and 20 are abutted with each other. .
In the bonding step, it is possible to irradiate a spot beam focused to a desired beam size by the condenser lens while scanning the abutted portion. It is also possible to generate a linear laser beam by an optical member such as a cylindrical lens or a diffractive optical element and irradiate the abutted portion. Furthermore, it is also possible to arrange a plurality of laser light sources along the abutted portion and irradiate all at once without scanning.

  The wavelength of the laser light is more preferably 800 nm to 2000 nm. Thus, when the wavelength of the laser beam is in the near-infrared region, the energy conversion efficiency to heat is good, and a stable laser beam is easily obtained.

  The light absorbing member 50a has a surface that has a higher light absorption rate than the resin film member with respect to the wavelength of the laser light to be used and has stability in a temperature environment of 300 ° C.

The light absorbing member 50a has a light absorption rate higher than that of the resin film member with respect to the wavelength of the laser light to be used, thereby absorbing the irradiated laser light R to generate heat, and the target resin film member 10, It plays a role of transferring heat to 20 and thermally welding the resin film members 10 and 20 to each other.
The light absorbing member 50a preferably has a light absorption rate of 10% or more with respect to the laser light to be used, more preferably has a light absorption rate of 20% or more, and has a light absorption rate of 30% or more. It is particularly preferred.
When the light absorbing material 50a has the light absorption rate of 10% or more, the resin film member can be more reliably melted by heat. Moreover, even if the laser power of the laser beam is relatively low, the resin film member can be sufficiently melted by heat, and the energy efficiency becomes higher.

Such light absorptance can be measured by a spectrophotometer (manufactured by JASCO, V-670, using an integrating sphere).
Moreover, the said light absorption rate can be adjusted with the thickness, component ratio, etc. of the light absorption member 50a.

In addition, since the light absorbing member 50a has a surface having stability under a temperature environment of 300 ° C., the light absorption rate of the surface of the light absorbing member 50a due to the influence of heat generated by laser light irradiation is increased. It can suppress changing. This makes it possible to perform laser welding without changing the laser light irradiation conditions and the like each time laser welding is performed. Further, it is possible to repeatedly perform laser welding using the same laser light irradiation conditions without replacing the light absorbing member. Therefore, the production of the resin film joined body becomes efficient.
From the viewpoint of suppressing the decrease in light absorbency on the surface of the light absorbing member 50a as described above, it is more preferable that the light absorbing member 50a has a surface having stability under a temperature environment of 350 ° C.
Here, in the present invention, “having stability under a temperature environment of 300 ° C.” means “not oxidizing under a temperature environment of 300 ° C.”.
Further, whether or not the surface is oxidized in the temperature environment can be measured by a nanoindentation method. Specifically, the light absorbing member 50a is arranged in a temperature environment of normal temperature (20 ° C.) and 300 ° C., the surface hardness is measured by the nanoindentation method, and the obtained surface hardness at normal temperature and 300 ° C. is compared. By doing so, it can be determined whether or not the surface of the light absorbing member 50a is oxidized at 300 ° C.
In this measurement method, it can be confirmed that the surface of the light absorbing member 50a is oxidized when the surface hardness at 300 ° C. is 80% or less with respect to the surface temperature at room temperature.
On the other hand, the oxidation temperature of the light absorbing member 50a can be obtained by measuring the temperature at which the ambient temperature is raised from room temperature and the surface hardness is 80% with respect to the surface temperature at room temperature using the measurement method. When the oxidation temperature of the light absorbing member 50a thus obtained exceeds 300 ° C, the light absorbing member 50a is not oxidized in a temperature environment of 300 ° C, that is, stable in a temperature environment of 300 ° C. Will have.

  Moreover, it is preferable that the light absorption member 50a is superior in heat resistance to the resin film members 10 and 20 so as not to melt together when the resin film members 10 and 20 are melted by laser irradiation. Specifically, the melting point of the light absorbing member 50a is preferably higher than the melting point of the resin film members 10 and 20, and the melting point of the light absorbing member 50a is preferably 300 ° C. or higher.

  The light absorbing member 50a preferably has a low thermal conductivity from the viewpoint of efficiently transferring the heat generated by laser irradiation to the resin film members 10 and 20, and specifically, the thermal conductivity is 100 W / It is preferably lower than m / K, more preferably the thermal conductivity is lower than 50 W / m / K, and still more preferably the thermal conductivity is lower than 20 W / m / K.

Such a light absorbing member 50a preferably contains diamond-like carbon (DLC), glassy carbon, or carbon graphite. Thereby, the laser beam R can be efficiently absorbed and heat can be generated. Further, it becomes possible to generate heat by absorbing laser light more efficiently under a temperature environment of 300 ° C. or higher. Further, the surface of the light absorbing member is likely to have stability under an environment of 300 ° C.
Diamond-like carbon means amorphous carbon in which a graphite structure and a diamond structure are mixed.

  The shape of the light absorbing member 50a is not particularly limited as long as it has a surface that contacts the lower surface or the upper surface of the abutted portion. In the present embodiment, the light absorbing member 50a is formed in a film shape and disposed on the surface of the base portion 50b, and is provided on the stage 50 together with the base portion 50b.

  Specifically, PVD method (for example, vacuum deposition method, ion plating method, sputtering method, laser ablation method, ion beam deposition method, ion implantation method, etc.) and CVD method (for example, thermal CVD method, plasma CVD method) The film-like light absorbing member 50a is provided on the base portion 50b by a method such as (method). Thus, since the light absorbing member 50a is in the form of a film, the heat generated by irradiation with the laser light R is easily retained on the surface layer of the light absorbing member 50a, that is, it is difficult to escape to the base portion 50b side. It becomes possible to efficiently transfer heat to the resin film members to join the resin film members together.

  The contact angle of the surface of the light absorbing member 50a with respect to 1 μL of water is preferably 60 ° or more, and more preferably 70 ° or more. When the contact angle is 60 ° or more, the surface is excellent in water repellency, so that the heat-melted resin film members 10 and 20 are difficult to adhere to the light absorbing member 50a. Thereby, the heat-welded resin film member can be easily peeled from the light absorbing member 50a. Further, it is possible to prevent the heat-welded resin film member from adhering to and sticking to the light absorbing member 50a, and the light absorbing member 50a can be repeatedly used more reliably. Accordingly, the bonding of the resin film member becomes more efficient.

  The surface of the light absorbing member 50a preferably has a Vickers hardness of 500 Hv or more, more preferably 1000 Hv or more, and particularly preferably 3000 Hv or more. When the surface has a Vickers hardness of less than 1000 Hv, the surface cannot withstand the stress caused by the heat generated by the absorption of the laser beam, and may deform and deteriorate the quality of the produced resin film joined body. On the other hand, when the Vickers hardness is 1000 Hv or more, the surface can sufficiently withstand the stress caused by the heat, and the deterioration of the quality of the produced resin film assembly can be suppressed.

  Further, the surface of the light absorbing member 50a preferably has an arithmetic average roughness (Ra) of less than 100 nm, more preferably less than 70 nm, and even more preferably less than 50 nm. When the arithmetic average roughness of the surface is 100 nm or more, the heat-melted resin film member is likely to adhere to the surface of the light absorbing member 50a due to the anchor effect, so that the attached resin film member is fixed and the light absorbing member 50a is fixed. May be difficult to reuse, or it may be difficult to peel off the thermally welded resin film member from the light absorbing member 50a. On the other hand, since the arithmetic average roughness of the surface is less than 100 nm, the occurrence of the anchor effect is suppressed, and the heat-melted resin film member is difficult to adhere to the light absorbing member 50a. After heat welding each other, it is possible to improve the releasability when peeling from the light absorbing member 50a.

  Further, the surface of the light absorbing member 50a may be subjected to a surface treatment from the viewpoint that dirt transfer can be prevented and water repellency is excellent. Examples of such surface treatment include fluorine treatment.

  The thickness of the light absorbing member 50a is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 2.0 μm, and particularly preferably 0.5 μm to 1.5 μm. When the thickness is 0.1 μm or more, the light absorbing member 50a easily absorbs the laser light R, and the resin film members 10 and 20 are easily heat-welded efficiently. Further, when the light absorbing member 50a is arranged on the surface of the base portion 50b as in the present embodiment because the thickness is 5.0 μm or less, when the temperature of the light absorbing member 50a is changed, the base portion It can suppress that the light absorption member 50a peels from the base part 50b by the difference in the linear expansion coefficient of 50b and the light absorption member 50a.

  Furthermore, the light absorbing member 50a may contain a fluorine element for the purpose of improving water repellency, and may contain an optimum element as appropriate according to the required specifications.

  Further, as described above, the stage 50 of the present embodiment includes the base portion 50b and the light absorbing member 50a disposed on the surface of the base portion 50b.

  The material of the base part 50b is not particularly limited as long as it does not impair the effects of the present invention. Examples of the material of the base part 50b include metals, glass, resin, rubber, ceramics, and the like. Glass is particularly preferred. Since the material of the base part 50b is glass, the heat conductivity of the glass is relatively low. Therefore, the heat generated from the light absorbing member 50a by the irradiation of the laser light R is difficult to move to the base part 50b side, and the heat Can be efficiently transmitted to the resin film members 10 and 20. Moreover, since the heat resistance of glass is high, the durability of the base portion 50b is increased.

  The stage 50 may include a primer layer (not shown) between the light absorbing member 50a and the base portion 50b. Examples of the material for the primer layer include silicone-based materials. Thus, by providing a primer layer, the adhesiveness of the light absorption member 50a with respect to the base part 50b is improved, and the light absorption member 50a becomes difficult to peel from the base part 50b.

As described above, according to the method for manufacturing a resin film assembly of the present embodiment, the step of the bonding portion is reduced, the step of applying the light absorber is not required, and the light absorber is further adhered as a foreign substance. While suppressing, it is possible to efficiently join the resin film members to produce the resin film joined body.
In addition, in the manufacturing method of the resin film conjugate | zygote of this embodiment, although it is not necessary to apply | coat a light absorber, on the other hand, you may use a less amount of light absorbers than before.

  In addition, the method for producing a resin film joined body according to the present embodiment particularly includes a so-called roll-to-roll conveying step in which a raw film wound in a roll shape is fed out and the fed raw film is taken up. In the method for producing an anti-film, this is a method suitable for so-called splicing, in which a belt-like long film is successively formed by joining the leading end side of the next original film to the end side of the preceding original film.

Moreover, in the resin film joined body produced by the method for producing a resin film joined body of this embodiment, the thickness of the joined portion (that is, the portion affected by the heat generated by laser irradiation) and the unjoined portion The difference from the thickness (that is, the portion not affected by the heat generated by laser irradiation) is preferably 20 μm or less, and more preferably 10 μm or less. When the difference in thickness is 20 μm or less, when the resin film bonded body is wound up in a roll shape, it is possible to further suppress the occurrence of a dent due to the difference in thickness. Further, from the viewpoint of further suppressing dents, the ratio of the bonded portion to the unbonded portion (ratio = the bonded portion / the unbonded portion) is preferably 1.5 or less. More preferably, it is 2 or less.
The difference in thickness can be adjusted by appropriately setting, for example, laser irradiation conditions, pressurizing conditions, hardness of the pressurizing member, and the like.

  Moreover, as shown in FIG. 3, the resin film joined body produced by the manufacturing method of the resin film joined body of this embodiment includes a roll body 90 obtained by winding a resin film joined body 80 in a roll shape. You can also

  Moreover, the above-mentioned resin film joined body and roll body are applicable to the optical film provided with these, for example. As such an optical film, for example, two or more end scales of a protective film for a polarizing plate (for example, triacetyl cellulose, cycloolefin polymer, etc.) used for a liquid crystal display device, etc. are used for the resin film assembly of this embodiment. A long original fabric obtained by joining by using as a resin film member of a manufacturing method is mentioned. Further, such an optical film can be applied to, for example, a polarizing film provided with the same. As this polarizing film, the polarizing plate obtained by bonding together the said elongate original fabric and the polarizer obtained by dyeing | staining a polyvinyl alcohol film and extending | stretching further through an adhesive agent is mentioned, for example.

<The manufacturing method of the resin film conjugate | zygote of other embodiment>
The manufacturing method of the resin film assembly of the present invention is not limited to the manufacturing method of the resin film assembly of the above embodiment, and the design can be changed as appropriate.
For example, in the method for manufacturing a resin film assembly of the above embodiment, the end surface of the second resin film member 20 is abutted against the end surface of the first resin film member 10, but the method for manufacturing the resin film assembly of the present invention is as follows. In addition, the other end surface of the resin film member 10 may be abutted against one end surface of the one resin film member 10. Specifically, in the method for producing a resin film joined body of the present invention, one end portion of one resin film member 10 and the other end portion of the resin film member 10 are overlapped, and both the overlapped end portions are overlapped. An end face forming step for forming cuts that are end faces that coincide with each other at these ends, and a butting step for matching one end face and the other end face formed in the end face forming step, You may implement a joining process.

Moreover, in the manufacturing method of the resin film conjugate | zygote of this invention, you may collect | recover two or more termination | terminus parts of an original fabric, what is called an end measure, and use it as a resin film member.
Conventionally, the end measure has a problem that it has been discarded without being sufficiently reused, but the end measure is reused as a resin film member as in the manufacturing method of such a resin film assembly. It is also preferable to manufacture a resin film assembly that hardly causes dents even from the viewpoint of suppressing material loss and reducing industrial waste.

  Next, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1
The following resin film member, laser, pressure member, and stage were used.
Resin film member 1 Triacetylcellulose (TAC) film (Fuji Film)
Thickness 80μm
Width 30mm
280 ° C
Tg 170 ° C
Light absorption rate 1% or less Resin film member 2 Same as the resin film member 1 Butt gap 20 μm
Laser type Semiconductor laser
Beam Top hat beam
Wavelength 940nm
Spot diameter 2mmφ
Laser power 20W
Power density 610W / cm ²
Scanning speed 15mm / s
Integrated dose 25J / cm ²
Pressure member Quartz glass plate (thickness: 10 mm)
Silicon rubber (1 mm thick) is inserted as an interphase member between the pressure member and the resin film member.
Pressing stage with a load of 15 kgf / cm ² Light absorbing member DLC member (thickness: 1 μm, light absorption at a wavelength of 940 nm: 25%, surface contact angle to 1 μL of water: 70 °, oxidation temperature 400 ° C.)
Base part Fused quartz glass (thickness: 5mm)
By depositing DLC on one side of fused silica glass, a DLC member that is a deposited film is produced.

  The end face of the resin film member 1 and the end face of the resin film member 2 are abutted on the DLC member, and the abutted portion is pressed against the surface of the DLC member of the stage by the pressurizing member, and the laser light 1 By scanning and irradiating the lines to generate heat, the end faces of the resin film members were thermally welded, the DLC member was peeled off from the abutted portions, and a resin film joined body was produced.

As a result, it was possible to produce a resin film joined body without a step without using a light absorber. Moreover, the obtained resin film joined body showed favorable bondability with a tensile strength of 110 N / 30 mm width.
Further, after the resin film assembly was peeled off, the light absorption rate on the surface of the DLC member was measured using a spectrophotometer (manufactured by JASCO, V-670, using an integrating sphere) at a measurement wavelength of 940 nm. No change in absorption rate was observed. As a result, it is possible to perform laser welding without changing the laser light irradiation conditions each time laser welding is performed, and the same laser light irradiation conditions can be used without replacing the light absorbing member. It was found that laser welding can be performed repeatedly. Therefore, it was found that the production of the resin film assembly is efficient.

(Example 2)
A resin film joined body was produced in the same manner as in Example 1 except that a polyvinyl alcohol film (made by Kuraray Co., Ltd., thickness 75 μm, width 30 mm, melting point 230 ° C., light absorption rate 1% or less) was used as the resin film member. did.
As a result, it was possible to produce a resin film joined body without a step without using a light absorber. Moreover, the obtained joined body showed favorable joining property with a tensile strength of 90 N / 30 mm.
Furthermore, when the light absorptivity was measured on the surface of the DLC member in the same manner as in Example 1 after the resin film joined body was peeled off, no change in the light absorptance on the surface of the DLC member was observed. As a result, as in Example 1, it was found that the production of the resin film assembly was efficient.

(Example 3)
A glassy carbon member (made by IBIDEN, thickness: 1 mm, light absorption rate: 82%, contact angle with respect to 1 μL of water: 66.8 °, oxidation temperature: 500 ° C.) is used as a light absorbing member for the stage, and a base portion is provided. A resin film joined body was produced in the same manner as in Example 1 except that the sheet-like glassy carbon member was used as the stage without using the sheet.
As a result, it was possible to produce a resin film joined body without a step without using a light absorber. Moreover, the obtained joined body showed favorable bondability with a tensile strength of 100 N / 30 mm.
Furthermore, when the light absorptivity was measured on the surface of the glassy carbon member in the same manner as in Example 1 after the resin film joined body was peeled off, no change in the light absorptance on the surface of the DLC member was observed. As a result, as in Example 1, it was found that the production of the resin film assembly was efficient.

Example 4
The following resin film member, laser, pressure member, and stage were used.
Resin film member 1 Cycloolefin polymer film (Zeon Corporation)
Thickness 80μm
Width 30mm
Tg 150 ° C
Light absorption rate 1% or less Resin film member 2 Same as the resin film member 1 Butt gap 20 μm
Laser type Semiconductor laser
Beam Top hat beam
Wavelength 940nm
Spot diameter 2mmφ
Laser power 80W
Power density 2546W / cm ²
Scanning speed 25mm / s
Integrated dose 203J / cm ²
Pressure member Quartz glass plate (thickness: 10 mm)
Silicon rubber (1 mm thick) is inserted as an interphase member between the pressure member and the resin film member.
Pressing stage at a load of 15 kgf / cm ² Light absorbing member Carbon graphite member (thickness: 1 mm, light absorption at wavelength 940 nm: 88.5%, contact angle for 1 μL of water: 115.6 °, oxidation temperature: 500 ℃)
Uses a sheet-like carbon graphite member as a stage without providing a base

Resin film member 1 and resin film member 2 were joined in the same manner as in Example 1 except that such conditions were used.
As a result, it was possible to produce a resin film joined body without a step without using a light absorber. Moreover, the obtained joined body showed favorable joining property with a tensile strength of 120 N / 30 mm.
Furthermore, when the light absorptivity was measured on the surface of the carbon graphite member in the same manner as in Example 1 after the resin film joined body was peeled off, no change in the light absorptance on the surface of the DLC member was observed. As a result, as in Example 1, it was found that the production of the resin film assembly was efficient.

(Comparative Example 1)
A light absorber (Clearweld (registered trademark) LD120C, 10 nL / mm ² , manufactured by Gentex) is applied to the upper surface of a polyimide film (manufactured by DuPont, Kapton V, thickness: 75 μm), and the polyimide film layer and the above light absorber layer The light absorption rate at a wavelength of 940 nm of the light absorber was set to 30%. Moreover, after using the thing only of the base part in which the light absorption member is not provided as a stage and mounting the said laminated body on the upper surface of a base part so that the said light absorber layer may be arrange | positioned above, a light absorber The end face of the resin film member 1 and the end face of the resin film member 2 were butted together on the layer. The laser power was 50 W and the scanning speed was 40 mm / sec. Other than that was carried out similarly to Example 1, and obtained the resin film conjugate | zygote.
As a result, the obtained joined body showed good joining properties with a tensile strength of 90 N / 30 mm. However, when the periphery of the bonded portion of the obtained resin film bonded body was simply wiped off with a cloth (cloth), contamination due to the light absorbent was confirmed. Therefore, it can be seen that this light absorbent can cause problems such as the fact that the light absorbent can cause dirt to adhere to the nip roller or the like when the resin film assembly is conveyed by so-called roll-to-roll. It was.

(Reference example)
A resin film joined body was produced in the same manner as in Example 1 except that the thickness of the light absorbing member was 0.2 μm, the oxidation temperature was 400 ° C., and the light absorption rate at a wavelength of 940 nm was 8%.
As a result, since the heat energy generated by irradiating the light absorbing member with laser light was insufficient, the tensile strength of the resin film joined body was as low as 10 N / 30 mm, and the joining was insufficient.

(Example 5)
A resin film joined body was obtained in the same manner as in Example 1 except that the thickness of the light absorbing member was 0.2 μm, the oxidation temperature was 400 ° C., the light absorption rate at a wavelength of 940 nm was 8%, and the laser power was 80 W. Produced.
As a result, the obtained joined body showed good joining properties with a shear rate of 90 N / 30 mm. However, energy required for bonding is large, and energy saving cannot be achieved.

(Comparative Example 2)
A resin film joined body was produced in the same manner as in Example 1 except that only a base portion having no light absorbing member was used as the stage. At this time, the light absorptance at a wavelength of 940 nm in the quartz glass plate as the base portion was 1% or less, and the oxidation temperature was 1600 ° C.
As a result, since the quartz glass plate was insufficient in light absorption, it was not possible to generate sufficient thermal energy to heat-melt the resin film members 1 and 2, and thus the resin film member 1 and 2 could not be joined.

(Example 6)
A DLC member (thickness: 1 μm, light absorption at a wavelength of 940 nm: 10%, contact angle with respect to 1 μL of water on the surface: 72 °, oxidation temperature: 400) (° C.), a resin film joined body was produced in the same manner as in Example 1 except that the DLC member was used as a light absorbing member and the laser power was 35 W.
As a result, it was possible to produce a resin film joined body without a step without using a light absorber. Moreover, the obtained joined body showed favorable joining property with a tensile strength of 160 N / 30 mm. Furthermore, when the light absorptance was measured about the surface of the DLC member, the change of the light absorptance in the DLC member surface was not recognized. As a result, as in Example 1, it was found that the production of the resin film assembly was efficient.

  10: first resin film member, 10a: piece, 20: second resin film member, 20a: piece, 30: suction device, 40: blade, 50: stage, 50a: light absorbing member, 50b: base portion, 60: Pressure member, 70: Interphase member, 80: Resin film joined body, 80a: Joined portion, 90: Roll, R: Laser light, 101: Resin film member, 102: Resin film member, 104: Light absorber, 105: Joining member, 106: Heat generating medium, 107: Resin film joined body, 100R: Laser light

Claims (7)

A method for producing a resin film assembly, in which the end faces of a resin film member are butted together to form a resin film assembly,
Using a light absorbing member having a surface having a high light absorptance with respect to the wavelength of the laser light to be used and having stability under a temperature environment of 300 ° C.,
By contacting the surface where the end faces are brought into contact with the surface and generating heat by irradiating the light absorbing member with laser light, the end faces of the resin film member are thermally welded, from the light absorbing member, A method for producing a resin film assembly, wherein the butted portions are peeled to form a resin film assembly.   The method for producing a resin film assembly according to claim 1, wherein the light absorbing member has a light absorption rate of 10% or more with respect to a wavelength of the laser light.   The method for producing a resin film joined body according to claim 1, wherein the light absorbing member contains diamond-like carbon, glassy carbon, or carbon graphite.   The said laser beam has a wavelength of 800 nm or more and 2000 nm or less, The manufacturing method of the resin film joined body in any one of Claims 1-3 characterized by the above-mentioned.   The method for producing a resin film joined body according to claim 1, wherein the resin film member has a thickness of 150 μm or less.   The said resin film member contains the thermoplastic resin which has 300 degreeC or less melting | fusing point or glass transition point, The manufacturing method of the resin film joined body in any one of Claims 1-5 characterized by the above-mentioned.   2. The resin film member contains at least one of triacetyl cellulose resin, polyethylene terephthalate resin, polycarbonate resin, polymethyl methacrylate resin, cycloolefin polymer, norbornene resin, or polyvinyl alcohol resin. The manufacturing method of the resin film conjugate | zygote in any one of -6.

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