Thermoplastic film bonding apparatus, thermoplastic film bonding system, and method for manufacturing laminates

Abstract

To provide an apparatus and method for easily fixing a thermoplastic film, used as a bonding material, to a substrate. [Solution] A thermoplastic film application apparatus comprising: a film supply device for supplying a thermoplastic film; a holding unit for rotatably holding a cylindrical or columnar base material having a central axis around the central axis; a pressure roller having a release surface and positioned opposite the base material; a heating device for heating the thermoplastic film; and a cutting device for cutting the thermoplastic film.

Description

[Technical Field]

[0001] This disclosure relates to a thermoplastic film application apparatus, a thermoplastic film application system, and a method for manufacturing a laminate. [Background technology]

[0002] In the design of various parts used in automobiles, home appliances, machine tools, and other applications, there is an increasing trend towards considering multi-material construction, which combines multiple dissimilar materials with different properties or properties, from the perspective of weight reduction or performance improvement. Generally, welding is used to join similar metals, and welding is used to join similar resins, while adhesives are generally used to join dissimilar materials. However, since joining with adhesives requires a series of steps, including adhesive application, fixing and holding the dissimilar materials together, and heat curing of the adhesive, there is a strong desire to simplify the joining process using adhesives.

[0003] It is known that dissimilar materials can be joined using a thermoplastic film as a joining material. Patent Document 1 (Japanese Patent No. 7485227) describes a method for manufacturing a joined body comprising a columnar base material A, a thermoplastic film B, and a resin C in this order, the method comprising: step 1 wrapping the thermoplastic film B circumferentially around at least a part of the outer circumference of the columnar base material A; and step 2 joining the resin C to the portion of the columnar base material A around the thermoplastic film B by insert molding to seal the thermoplastic film B. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 7485227 [Overview of the project] [Problems that the invention aims to solve]

[0005] It is not easy to wrap a thermoplastic film that does not exhibit tack at room temperature around a tubular, columnar, or rod-shaped substrate as a bonding material and fix it in place. In this disclosure, "fixing" is a concept that encompasses temporary fixing and bonding. According to JIS K 6800:2006, tack is defined as "the property of an adhesive that can form a bond immediately after contact with the surface of the adherend with very light force." It is possible to fix the thermoplastic film to the substrate by preheating the substrate to induce or improve tack when the thermoplastic film comes into contact with the substrate. However, it is difficult to apply preheating of the substrate to substrates containing resins with low heat resistance, or thin-walled tubular substrates that are easily deformed by heat.

[0006] This disclosure provides an apparatus and method for easily fixing a thermoplastic film as a bonding material to a substrate. [Means for solving the problem]

[0007] This disclosure includes the following aspects: [Aspect 1] A film supply device that supplies thermoplastic film, A holding part that holds a cylindrical or columnar base material having a central axis so as to be rotatable around the central axis, The surface has release properties, and a pressure roller is positioned opposite the substrate, A heating device for heating the thermoplastic film, A cutting device for cutting the thermoplastic film, A thermoplastic film application apparatus equipped with the following features. [Aspect 2] The thermoplastic film application apparatus according to Embodiment 1, wherein the heating device is a device for heating the pressure roller, and the thermoplastic film is heated by the heated pressure roller. [Aspect 3] The thermoplastic film application apparatus according to embodiment 1 or 2, wherein the pressure roller is a silicone rubber roller. [Aspect 4] A thermoplastic film application apparatus according to any one of embodiments 1 to 3, further comprising a second heating device for preheating the substrate. [Aspect 5] A thermoplastic film application apparatus according to any one of embodiments 1 to 4, further comprising a moving device for moving the pressure roller between a pressing position in which the thermoplastic film is pressed against the substrate and an open position in which no pressure is applied to the thermoplastic film. [Aspect 6] The thermoplastic film bonding apparatus according to embodiment 5, further comprising a pressure measuring device for measuring the pressure applied to the pressure roller at the aforementioned bonding position. [Aspect 7] A thermoplastic film application apparatus according to any one of embodiments 1 to 6, wherein the thermoplastic film installed in the film supply device is a continuous film in roll form, and the film supply device is a film unwinding device equipped with guide rollers and a tension detection mechanism. [Aspect 8] A thermoplastic film application apparatus according to any one of embodiments 1 to 7, wherein both the contact surface of the thermoplastic film with the pressure roller and the contact surface with the substrate are thermoplastic. [Aspect 9] A thermoplastic film application system comprising a thermoplastic film application apparatus according to any one of embodiments 1 to 8, and a thermoplastic film in which both the contact surface with the pressure roller and the contact surface with the substrate are thermoplastic. [Aspect 10] A method for manufacturing a laminate comprising a cylindrical or columnar base material having a central axis and a thermoplastic film attached to at least a portion of the outer circumference of the base material, To provide a thermoplastic film application apparatus according to any one of embodiments 1 to 8, Attaching the substrate to the holding part, The thermoplastic film is supplied from the film supply device between the pressure roller and the substrate. Heating the thermoplastic film using the heating device, and Pressing the softened or melted thermoplastic film against the substrate using the rotating pressure roller to attach the thermoplastic film to the substrate A method comprising the above. [Aspect 11] The method according to aspect 10, comprising heating the thermoplastic film in a temperature range corresponding to the rubber region of the thermoplastic film, wherein the thermoplastic film has a rubber region in a dynamic viscoelastic curve. [Aspect 12] The method according to aspect 10 or 11, wherein both the contact surface of the thermoplastic film with the pressure roller and the contact surface with the substrate exhibit thermoplasticity. [Aspect 13] The method according to any one of aspects 10 to 12, wherein the thermoplastic film exhibits tack at 40 °C or higher. [Aspect 14] The method according to any one of aspects 10 to 13, wherein the thickness of the thermoplastic film is 10 μm to 3 mm. [Aspect 15] The method according to any one of aspects 10 to 14, further comprising preheating the substrate. [Aspect 16] The method according to any one of aspects 10 to 15, further comprising pretreating the surface of the substrate. [Aspect 17] The thermoplastic film is a continuous film in roll form, and controlling the rotational speed of the pressure roller so that the tension of the thermoplastic film before being attached to the substrate is 0.1 N / mm 2 ~2 N / mm 2 The method according to any one of aspects 10 to 16, comprising the above. [Aspect 18] The method according to any one of aspects 10 to 17, wherein the thermoplastic film mainly contains an amorphous thermoplastic resin. [Aspect 19] The method according to embodiment 18, wherein the amorphous thermoplastic resin contains a thermoplastic epoxy resin which is a polymer of (a) a bifunctional epoxy resin monomer or oligomer and (b) a bifunctional compound having the same or different two functional groups selected from the group consisting of phenolic hydroxyl group, carboxyl group, mercapto group, isocyanato group and cyanate ester group. [Embodiment 20] The method according to embodiment 18 or 19, wherein the amorphous thermoplastic resin contains a phenoxy resin which is a polyhydroxy polyether synthesized from a bisphenol compound and epichlorohydrin. [Embodiment 21] The method according to any one of embodiments 18 to 20, wherein the thermoplastic film contains an amorphous thermoplastic resin having an epoxy equivalent of 1,600 g / eq. or more or not containing an epoxy group. [Embodiment 22] A method for manufacturing a joined body, comprising joining a second base material by insert molding or overmolding on the thermoplastic film of the laminate manufactured by the method according to any one of embodiments 10 to 21. [Advantages of the Invention]

[0008] According to the present disclosure, there are provided an apparatus and a method capable of easily fixing a thermoplastic film as a joining material to a base material.

[0009] The above description should not be regarded as disclosing all embodiments of the present invention and all advantages related to the present invention. [Brief Description of the Drawings]

[0010] [Figure 1] It is a schematic diagram of a thermoplastic film sticking apparatus of one embodiment. [Modes for Carrying Out the Invention]

[0011] The embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these forms, and various applications are possible within its spirit and scope of implementation.

[0012] In this disclosure, when "~" is used for a numerical range, the numbers at both ends are the upper and lower limits, respectively, and are included in the numerical range. If multiple upper or lower limits are listed, a numerical range can be created from all combinations of upper and lower limits. Similarly, if multiple numerical ranges are listed, separate numerical ranges can be created by individually selecting and combining upper and lower limits from those ranges. Regarding reference numbers in drawings, elements with the same or similar numbers in different drawings are indicated as being the same or similar elements.

[0013] In this disclosure, joining means connecting two objects together, with adhesion and welding being sub-concepts. Adhesion means bringing two adherends (objects to be joined) into a joined state via an organic material (such as a tape or adhesive, a curable resin, or a thermoplastic resin). Welding means joining by utilizing molecular diffusion, entanglement and crystallization that occurs during the process of melting the surface of a thermoplastic resin or the like with heat, followed by contact pressurization and cooling, or by utilizing intermolecular interactions with the substrate that occur during melting.

[0014] [Thermoplastic film application device] One embodiment of a thermoplastic film application apparatus comprises a film supply device for supplying a thermoplastic film, a holding unit for rotatably holding a cylindrical or columnar substrate having a central axis around the central axis, a pressure roller having a release surface and positioned opposite the substrate, a heating device for heating the thermoplastic film, and a cutting device for cutting the thermoplastic film.

[0015] By heating a thermoplastic film with a heating device to induce tack, and then pressing the tacked thermoplastic film against a cylindrical or columnar substrate held in a holding section in a state where it can freely rotate around a central axis, while rotating a pressure roller, the thermoplastic film can be easily fixed to the substrate.

[0016] Figure 1 shows a schematic diagram of a thermoplastic film application apparatus according to one embodiment. The thermoplastic film application apparatus 10 comprises a film supply device 11 for supplying thermoplastic film 20, a holding unit 12 for rotatably holding a cylindrical or columnar base material 30 having a central axis around the central axis, a pressure roller 13 having a release surface and positioned opposite the base material 30, a heating device 14 for heating the thermoplastic film 20, and a cutting device 15 for cutting the thermoplastic film 20.

[0017] In Figure 1, the film supply device 11 is shown as a film unwinding device that supplies thermoplastic film 20, which is a continuous film in roll form. The film unwinding device includes, for example, a shaft to which the roll 21 of thermoplastic film 20 is attached, a drive motor to rotate the shaft, and a powder clutch to control the torque applied to the shaft.

[0018] The film supply device 11 may include a guide roller 111 and a tension detection mechanism 112. The guide roller 111 controls the position of the thermoplastic film 20 in the direction of travel and the width direction, and can suppress the occurrence of wrinkles, twists, etc. in the thermoplastic film 20. The guide roller 111 may be a single roller or a combination of multiple rollers. The tension detection mechanism 112 may be, for example, a load cell that measures the tension applied to the guide roller 111. Based on the tension measured by the load cell, the powder clutch of the film unwinding device is operated via a feedback loop, thereby adjusting the tension applied to the thermoplastic film 20 to a desired range, and suppressing unwanted tearing, stretching, etc. of the thermoplastic film.

[0019] The film supply device 11 is not limited to a film unwinding device, but may be, for example, a belt conveyor or roller conveyor that supplies thermoplastic film 20 in sheet form.

[0020] The holding part 12 is not particularly limited as long as it can hold the base material 30 so as to be rotatable around its central axis. The holding part 12 shown in Figure 1 is shown as a free bearing chuck that holds the base material 30 with three claws that contact the inner wall of the cylindrical base material 30, but the manner in which the base material 30 is held is not limited to this.

[0021] The pressure roller 13 has release properties on its surface and is positioned opposite the base material 30. The material of the pressure roller 13 is not particularly limited, but it is preferably an elastic material because it is possible to adhere it to the base material 30 while suppressing the tearing of the thermoplastic film 20. Examples of elastic materials include silicone rubber, urethane rubber, and nitrile rubber. The surface of the pressure roller 13 may have a release coating using a silicone release agent, a fluorine-based release agent, etc., and a release-possessing layer such as a silicone rubber layer may be laminated around the core (for example, a core made of urethane rubber, nitrile rubber, etc.). The material constituting the pressure roller 13 itself may have release properties, such as a silicone rubber roller.

[0022] The pressure roller 13 is preferably a silicone rubber roller. The silicone rubber roller has elasticity suitable for pressing and fixing the thermoplastic film 20 to the base material 30, and has high release properties that allow the thermoplastic film 20, which has tack before it cools down after fixing is complete, to be quickly peeled off the pressure roller 13.

[0023] The heating device 14 is not particularly limited as long as it can heat the thermoplastic film 20. In one embodiment, the heating device 14 is a device that heats the pressure roller 13, and the thermoplastic film 20 is heated by the heated pressure roller 13. In Figure 1, the heating device 14 is positioned inside the pressure roller 13 and temporarily heats the pressure roller 13. When the heated pressure roller 13 is brought into contact with the thermoplastic film 20, the thermoplastic film 20 is heated. In another embodiment, the heating device 14 directly heats the thermoplastic film 20. The heating device 14 may be an IR lamp positioned close to the pressure roller 13 or the thermoplastic film 20, or it may be a blower that supplies hot air to the pressure roller 13 or the thermoplastic film 20.

[0024] It is preferable to place the heating device 14 inside the pressure roller 13. By placing the heating device 14 inside the pressure roller 13, the spatial distance between the heat source and the thermoplastic film 20 can be reduced, allowing for more precise control of the temperature of the thermoplastic film 20. This makes it possible to adjust the tack of the thermoplastic film 20 to a range suitable for fixing while ensuring the tensile strength of the thermoplastic film 20, thereby effectively suppressing unwanted breakage, elongation, etc. of the thermoplastic film 20.

[0025] The cutting device 15 is not particularly limited as long as it can cut the thermoplastic film 20 so that the thermoplastic film 20 is applied to the substrate 30 to a desired length, and examples include a stainless steel blade and a thermal cutting device.

[0026] The thermoplastic film application apparatus 10 may further include a second heating device 16 for preheating the substrate 30. The second heating device 16 is not particularly limited as long as it can preheat the substrate 30, and examples include an IR lamp and a hot air blower. By preheating the substrate 30 using the second heating device 16, the decrease in tack of the thermoplastic film 20 caused by the temperature drop when the heated thermoplastic film 20 comes into contact with the substrate 30 can be suppressed, and fixing can be performed more effectively.

[0027] The thermoplastic film application apparatus 10 may further include a moving device 17 that moves the pressure roller 13 between a pressing position where the thermoplastic film 20 is pressed against the substrate 30 and an open position where no pressure is applied to the thermoplastic film 20. In Figure 1, the moving device 17 is shown as an arm and drive mechanism (not shown) that holds the axis of the pressure roller 13 and enables the lateral movement of the pressure roller 13 (x direction in Figure 1). By using the moving device 17, it is possible to easily attach and detach the substrate 30 from the holding part 12. In addition, the thermoplastic film 20 can be pressed against the substrate 30 while moving the pressure roller 13 to match the shape of the substrate 30 using the moving device 17. This makes it possible to reliably apply the thermoplastic film 20 even to substrates 30 whose cross-sectional shape perpendicular to the length direction of the substrate 30 is not circular.

[0028] The thermoplastic film application apparatus 10 may further include a pressure measuring device 18 that measures the pressure applied to the pressure roller 13 at the pressing position. The pressure measuring device 18 is not particularly limited and includes, for example, a load cell that detects the pressure applied to the shaft of the pressure roller 13 and a spring-type pressure sensor. By adjusting the pressure applied to the thermoplastic film 20 to the substrate 30 based on the pressure applied to the pressure roller 13 measured using the pressure measuring device 18, the thermoplastic film 20 can be effectively fixed while suppressing excessive deformation, breakage, etc. of the thermoplastic film 20. Alternatively, the pressure measuring device 18 can be used to pre-determine the correlation between the gap between the pressure roller 13 and the substrate 30 and the pressure distribution using a pressure sensor sheet or pressure measuring film capable of detecting the pressure distribution, and by adjusting the positional relationship between the pressure roller 13 and the substrate 30 based on this correlation to control the amount of the gap, the thermoplastic film 20 can be pressed to the substrate 30 with an appropriate pressure distribution.

[0029] The thermoplastic film application apparatus 10 may include guide plates 19 that guide the direction of travel of the thermoplastic film 20. In Figure 1, a pair of guide plates 19 are arranged to sandwich the thermoplastic film 20. The direction of travel of the thermoplastic film 20 is controlled by the guide plates 19, which can suppress displacement, breakage, elongation, etc., of the thermoplastic film 20 that may occur due to fluttering or other factors.

[0030] In one embodiment, both the contact surface of the thermoplastic film 20 with the pressure roller 13 and the contact surface with the substrate 30 exhibit thermoplastic properties. In such a thermoplastic film 20, tack is developed on both the contact surface with the pressure roller 13 and the contact surface with the substrate 30 when heated. The tack on the contact surface with the substrate 30 contributes to the fixation of the thermoplastic film 20 to the substrate 30. On the other hand, even if tack is developed on the contact surface with the pressure roller 13, the thermoplastic film 20 does not adhere to the pressure roller 13 due to the release properties applied to the surface of the pressure roller 13. After fixation to the substrate 30, the contact surface of the thermoplastic film 20 with the pressure roller 13 is exposed and contributes to bonding with a second substrate that can be formed by insert molding, overmolding, etc. Therefore, the thermoplastic film 20 can be used as a bonding material between the substrate 30 and the second substrate.

[0031] In Figure 1, the thermoplastic film application apparatus 10 is shown with the z-axis parallel to the direction of gravity, i.e., in the vertical direction. However, the x-axis or y-axis may also be parallel to the direction of gravity. The z-axis, x-axis, or y-axis may also be approximately parallel to the direction of gravity. In this disclosure, "approximately parallel" means a direction that is inclined within a range of 10 degrees or less with respect to the direction of gravity. It is preferable that the z-axis is parallel or approximately parallel to the direction of gravity. This makes it possible to suppress unevenness, deformation, twisting, etc. in the width direction of the thermoplastic film 20 and stabilize the supply speed in the direction of travel of the thermoplastic film 20.

[0032] [Thermoplastic film lamination system] In one embodiment, a thermoplastic film application system is provided, which includes the thermoplastic film application apparatus 10 described above and a thermoplastic film 20 in which both the contact surface with the pressure roller 13 and the contact surface with the substrate 30 are thermoplastic.

[0033] [Method for manufacturing laminates] A method for manufacturing a laminate according to one embodiment is a method for manufacturing a laminate comprising a cylindrical or columnar substrate having a central axis and a thermoplastic film attached to at least a portion of the outer circumference of the substrate, To provide the above thermoplastic film application apparatus, To attach the base material to the holding part, The thermoplastic film is supplied from the film supply device between the pressure roller and the substrate. Heating a thermoplastic film using a heating device, and The process of attaching a thermoplastic film to a substrate by pressing the softened or melted thermoplastic film onto the substrate using a rotating pressure roller. This includes the ability to easily produce laminates in which a thermoplastic film is fixed to a tubular or columnar substrate.

[0034] The following describes an exemplary embodiment of the method for manufacturing the laminate, with reference to Figure 1.

[0035] A cylindrical or columnar base material 30 having a central axis is attached to the holding part 12 of the thermoplastic film application apparatus 10 described above. For example, the base material 30 can be attached to the holding part 12 by inserting the jaws of the free bearing chuck, which is the holding part 12, into the inside of the cylindrical base material 30, spreading the jaws outward, and pressing them against the inner wall of the base material 30.

[0036] The shape of the cylindrical or columnar base material 30 is not particularly limited. Examples of cross-sectional shapes perpendicular to the longitudinal direction of the base material 30 include circular, semicircular, and elliptical shapes, as well as squares, rectangles, triangles, and other polygons. The polygons may be regular polygons or not. The cross-sectional shape perpendicular to the longitudinal direction of the base material 30 is preferably circular or elliptical.

[0037] Examples of materials for the base material 30 include resin, metal, and inorganic material. The base material 30 may be one type or a combination of two or more types.

[0038] The resin is not particularly limited and includes, for example, thermoplastic resins and cured products of curable resins. Examples of thermoplastic resins include at least one selected from the group consisting of polyolefins such as polyethylene and polypropylene and their acid-modified products, polystyrene, polymethyl methacrylate, AS resin, ABS resin, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, polyimide, polyamide, polyamide-imide, polyetherimide, polyethersulfone, polyphenylene ether and its modified products, polyphenylene sulfide, polyoxymethylene, polyarylate, polyether ketone, polyether ether ketone, polyether ketone ketone, and thermoplastic epoxy resins. Examples of curable resins include at least one selected from the group consisting of epoxy resins, vinyl ester resins, unsaturated polyester resins, phenolic resins, and urethane resins. The resin may also be a fiber-reinforced plastic (FRP) containing reinforcing fibers such as carbon fibers, glass fibers, and cellulose nanofibers.

[0039] Examples of metals include aluminum, iron, copper, magnesium, and titanium, and are not particularly limited. In this disclosure, single-element metal notations such as "iron" include the single-element metal and its alloys, such as iron and its alloys. Examples of iron alloys include steel and stainless steel.

[0040] Inorganic materials are not particularly limited and include, for example, glass, ceramics, and carbon molded products. Examples of glass include general glass, as well as heat-resistant glass, fire-resistant glass, fireproof glass, and chemically strengthened glass. Specific examples of chemically strengthened glass include soda-lime glass, lead glass, borosilicate glass, and quartz glass. Examples of ceramics include fine ceramics used in semiconductors, automobiles, and industrial equipment, specifically oxide ceramics such as alumina, zirconia, and barium titanate; hydroxide ceramics such as hydroxyapatite; carbide ceramics such as silicon carbide; and nitride ceramics such as silicon nitride.

[0041] The surface of the substrate 30 is preferably pre-treated for the purpose of removing contaminants, achieving an anchoring effect, or both. Examples of pre-treatments include degreasing, UV ozone treatment, blasting, polishing, plasma treatment, corona discharge treatment, laser treatment, etching, flame treatment, and boehmite treatment. The pre-treatment may be performed individually or in combination of two or more types. Known methods can be used as specific pre-treatment methods. Pre-treatments that clean the surface of the substrate 30 or pre-treatments that create irregularities on the surface are preferred. Specifically, if the substrate 30 contains aluminum, copper, glass, ceramic, or iron, at least one selected from the group consisting of degreasing, UV ozone treatment, blasting, polishing, plasma treatment, and etching is preferred. If the base material 30 includes FRP, polypropylene, polycarbonate, polymethyl methacrylate, polyetherimide, polyamide, or polybutylene terephthalate, at least one treatment selected from the group consisting of degreasing, UV ozone treatment, blasting, polishing, plasma treatment, and corona discharge treatment is preferred.

[0042] Degreasing is a method of removing oil and other contaminants from the surface of the substrate 30 by dissolving them with organic solvents such as alcohols like ethanol and isopropanol, or ketones like acetone.

[0043] UV ozone treatment is a surface cleaning or surface modification method that utilizes the energy of short-wavelength ultraviolet light emitted from a low-pressure mercury lamp and the resulting ozone (O3). In the case of glass, it is one option for pretreatment to remove organic impurities. Generally, cleaning and surface modification equipment using low-pressure mercury lamps is called a "UV ozone cleaner," "UV cleaning equipment," or "ultraviolet surface modification equipment."

[0044] Examples of blasting processes include wet blasting, shot blasting, and sandblasting. Wet blasting can create a finely textured surface.

[0045] Polishing processes include, for example, buff polishing using abrasive cloth, roll polishing using abrasive paper such as sandpaper, and electrolytic polishing.

[0046] Plasma treatment is a method of activating a substrate 30 by exciting molecules by bombarding it with a plasma beam formed using a high-voltage power supply and a rod. An example of this is atmospheric pressure plasma treatment, which can impart hydroxyl groups or polar groups to the surface of the substrate 30.

[0047] Corona discharge treatment is a method in which electrons emitted from an electrode cleave the polymer main chain or side chains near the resin surface, and the resulting radicals are used to generate hydroxyl groups or polar groups on the surface.

[0048] Laser treatment is a method of changing the surface properties of a substrate 30 by rapidly heating and cooling only its surface using laser irradiation, and is effective for roughening surfaces.

[0049] Etching processes include, for example, chemical etching processes such as the alkali method, phosphoric acid-sulfuric acid method, fluoride method, chromic acid-sulfuric acid method, and iron salt method, as well as electrochemical etching processes such as electrolytic etching.

[0050] Flame treatment is a method of hydrophilizing a substrate 30 by burning a mixture of combustion gas and air to create plasma from the oxygen in the air, and then applying the oxygen plasma to the substrate 30.

[0051] Boehmite treatment is performed, for example, by treating an aluminum substrate with hot water at approximately 90-100°C, forming a boehmite (aluminum hydrated oxide) film on the surface of the aluminum substrate. Ammonia, triethanolamine, etc., may be added to the water as reaction accelerators. For example, boehmite treatment can be performed by immersing the aluminum substrate in hot water at 90-100°C containing triethanolamine at a concentration of 0.1-5.0% by mass for 3 seconds to 5 minutes. In boehmite treatment, baking is preferable after treatment with hot water to form a good boehmite film.

[0052] Next, the thermoplastic film 20 is supplied from the film supply device 11 between the pressure roller 13 and the substrate 30. In Figure 1, the thermoplastic film 20 is a continuous film in roll form. The roll 21 is attached to the shaft of the film unwinding device, and the thermoplastic film 20 is pulled from the roll 21 and placed on the guide roller 111, and advanced through a pair of guide plates 19 towards the area between the pressure roller 13 and the substrate 30. Once the thermoplastic film 20 reaches the area between the pressure roller 13 and the substrate 30, the moving device 17 is used to move the pressure roller 13 from the open position to the compressed position and rotate it. This ensures that the thermoplastic film 20 is continuously supplied between the pressure roller 13 and the substrate 30.

[0053] The thermoplastic film 20 contains a thermoplastic resin as its main component. Preferably, the thermoplastic film 20 is adhesive to the substrate 30. In this disclosure, "main component" means the component with the highest mass content among the resin components of the thermoplastic film 20. Preferably, the thermoplastic film 20 contains 50% by mass or more of the resin component, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. In this disclosure, "film" means a resin composition mainly composed of a thermoplastic resin that has been formed into a thin film. Unlike cases where a curable resin is used as a bonding material, the thermoplastic film 20 can be recycled and repaired by softening or melting it with heat even after the bonded body has been formed.

[0054] The thermoplastic film 20 preferably contains an amorphous thermoplastic resin as its main component. An amorphous thermoplastic resin is a resin that has no crystals, or only a small amount of crystals, and whose heat of fusion is 15 J / g or less. The heat of fusion of the amorphous thermoplastic resin is preferably 11 J / g or less, more preferably 7 J / g or less, even more preferably 4 J / g or less, and it is particularly preferable that the melting peak is below the detection limit. By using a thermoplastic film 20 containing an amorphous thermoplastic resin with a heat of fusion of 15 J / g or less as its main component, the rapid decrease in viscosity seen in conventional crystalline hot-melt adhesives does not occur during heating, and it does not reach a low viscosity state (e.g., 0.001 Pa·s to 100 Pa·s) even in high-temperature regions exceeding 200°C. Therefore, even when heated and softened or melted by the heating device 14, the thermoplastic film 20 can maintain its shape to some extent, and the thermoplastic film 20 can be pressed onto the substrate 30 using the pressure roller 13. This allows the thermoplastic film 20 to be fixed to the substrate 30 while maintaining a stable thickness. Maintaining a stable thickness of the thermoplastic film 20 is advantageous for bonding the second substrate onto the thermoplastic film 20 with high bonding strength.

[0055] The heat of fusion of amorphous thermoplastic resin is calculated from the area of ​​the endothermic peak measured by a differential scanning calorimeter (DSC) and the mass of the thermoplastic resin component. If inorganic fillers are included in the thermoplastic film 20, the heat of fusion is calculated from the mass of the thermoplastic resin component excluding the inorganic fillers. Specifically, the heat of fusion is calculated by weighing 2 mg to 10 mg of the sample, placing it in an aluminum pan, and heating it from 23°C to over 200°C at a rate of 10°C / min using a DSC (DSC8231 manufactured by Rigaku Corporation) to obtain a DSC curve. Then, the heat of fusion is calculated based on the area of ​​the endothermic peak at melting obtained from the DSC curve and the weighed value mentioned above.

[0056] From the viewpoint of imparting the above-mentioned properties of amorphous thermoplastic resin to the thermoplastic film 20, the content of amorphous thermoplastic resin in the thermoplastic film 20 is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and most preferably 90% by mass or more, based on the mass of the resin component.

[0057] From the viewpoint of bonding strength with the second substrate and toughness as a bonding material, the amorphous thermoplastic resin preferably contains a thermoplastic epoxy resin or a phenoxy resin. Because thermoplastic epoxy resins and phenoxy resins have low cohesive force within the resin and may contain hydroxyl groups, they have a strong interaction with the substrate 30 and the second substrate, and can bond dissimilar materials with a higher bonding strength than conventional crystalline hot melt adhesives.

[0058] From the viewpoint of storage, it is preferable that the thermoplastic film 20 contains an epoxy equivalent of 1,600 g / eq. or more, or an amorphous thermoplastic resin that does not contain epoxy groups. The epoxy equivalent is preferably 2,000 g / eq. or more, more preferably 5,000 g / eq. or more, even more preferably 9,000 g / eq. or more, and particularly preferably above the detection limit, meaning that epoxy groups are substantially undetectable. An epoxy equivalent above the detection limit means that when the epoxy equivalent is measured according to JIS K 7236:2001 described later, no epoxy groups are detected.

[0059] In this disclosure, the epoxy equivalent (mass of thermoplastic resin containing 1 mole of epoxy groups) is the epoxy equivalent value of the thermoplastic resin contained in the thermoplastic film 20, and is a value measured by the method specified in JIS K 7236:2001 (unit "g / eq."). Specifically, it is the value obtained by adding brominated tetraethylammonium acetate solution to the thermoplastic resin and titrating it with a 0.1 mol / L perchloric acid-acetic acid solution using a potentiometric titrator. In the case of solvent-diluted products (resin varnish), the value is calculated as a solid content equivalent from the non-volatile content. In the case of a mixture of two or more resins, it can also be calculated from the respective content and epoxy equivalent.

[0060] The thermoplastic epoxy resin is preferably a polymer of (a) a difunctional epoxy resin monomer or oligomer and (b) a difunctional compound having two identical or different functional groups selected from the group consisting of phenolic hydroxyl groups, carboxyl groups, mercapto groups, isocyanate groups, and cyanate ester groups. In this disclosure, polyhydroxy polyethers synthesized from bisphenol compounds and epichlorohydrin are excluded from the polymer. By using these compounds, polymerization reactions that form linear polymers proceed preferentially, making it possible to obtain a thermoplastic epoxy resin with desired properties.

[0061] (a) A difunctional epoxy resin monomer or oligomer means an epoxy resin monomer or oligomer having two epoxy groups in its molecule. (a) Examples of difunctional epoxy resin monomers or oligomers include bisphenol A type epoxy resin, bisphenol F type epoxy resin, difunctional phenol novolac type epoxy resin, bisphenol AD ​​type epoxy resin, biphenyl type epoxy resin, difunctional naphthalene type epoxy resin, difunctional alicyclic epoxy resin, difunctional glycidyl ester type epoxy resin (e.g., diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl dimer acid ester, etc.), difunctional glycidylamine type epoxy resin (e.g., diglycidylaniline, diglycidyltoluidine, etc.), difunctional heterocyclic epoxy resin, difunctional diarylsulfone type epoxy resin, hydroquinone type epoxy resin (e.g., hydroquinone diglycidyl ether, 2 Examples include ,5-di-tert-butylhydroquinone diglycidyl ether, resorcinol diglycidyl ether, etc., difunctional alkylene glycidyl ether compounds (e.g., butanediol diglycidyl ether, butenediol diglycidyl ether, butinediol diglycidyl ether, etc.), difunctional glycidyl group-containing hydantoin compounds (e.g., 1,3-diglycidyl-5,5-dialkylhydantoin, 1-glycidyl-3-(glycidoxyalkyl)-5,5-dialkylhydantoin, etc.), difunctional glycidyl group-containing siloxanes (e.g., 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, α,β-bis(3-glycidoxypropyl)polydimethylsiloxane, etc.), and modified products thereof. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin are preferred from the viewpoint of reactivity and workability.

[0062] Examples of the difunctional compounds having a phenolic hydroxyl group in (b) include mononuclear aromatic dihydroxy compounds having one benzene ring, such as catechol, resorcinol, and hydroquinone; bisphenol compounds such as bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)methane (bisphenol F), and bis(4-hydroxyphenyl)ethane (bisphenol AD); compounds having a condensed ring, such as dihydroxynaphthalene; difunctional phenol compounds with an allyl group introduced, such as diallylresorcinol, diallylbisphenol A, and triallyldihydroxybiphenyl; and dibutylbisphenol A.

[0063] Examples of difunctional compounds having a carboxyl group in (b) include adipic acid, succinic acid, malonic acid, cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid.

[0064] Examples of the difunctional compounds having a mercapto group in (b) include ethylene glycol bisthioglycolate and ethylene glycol bisthiopropionate.

[0065] Examples of difunctional compounds having an isocyanate group in (b) include diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), and tolylene diisocyanate (TDI).

[0066] Examples of difunctional compounds having the cyanate ester group of (b) include 2,2-bis(4-cyanatophenyl)propane, 1,1-bis(4-cyanatophenyl)ethane, and bis(4-cyanatophenyl)methane.

[0067] Among the difunctional compounds of (b), difunctional compounds having a phenolic hydroxyl group are preferred because they facilitate the formation of thermoplastic polymers, difunctional compounds having two phenolic hydroxyl groups and a bisphenol or biphenyl structure are preferred from the viewpoint of heat resistance and bonding properties, and at least one selected from the group consisting of bisphenol A, bisphenol F, and bisphenol S is preferred from the viewpoint of heat resistance and cost.

[0068] When (a) is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, or a biphenyl type epoxy resin, and (b) is bisphenol A, bisphenol F, or bisphenol S, the polymer obtained by polymerization of (a) and (b) has a main backbone consisting of a paraphenylene structure and ether bonds, which are linked by alkylene groups, and a side chain with hydroxyl groups generated by polyaddition. The linear structure consisting of the paraphenylene backbone increases the mechanical strength of the polymer after polymerization, and the hydroxyl groups arranged in the side chain improve adhesion to the substrate. Therefore, high bonding strength can be achieved while maintaining the workability of the thermoplastic film 20.

[0069] Phenoxy resins are polyhydroxy polyethers synthesized from bisphenol compounds and epichlorohydrin, and are thermoplastic. Methods for producing phenoxy resins include a direct reaction between a divalent phenol compound and epichlorohydrin, and an addition polymerization reaction between a diglycidyl ether of a divalent phenol compound and the divalent phenol compound. The phenoxy resin used in this disclosure can be obtained using either method. In the case of a direct reaction between a divalent phenol compound and epichlorohydrin, examples of divalent phenol compounds include phenol compounds such as bisphenol A, bisphenol F, bisphenol S, biphenol, biphenylenediol, and fluo-orangephenyl; and aliphatic glycols such as ethylene glycol, propylene glycol, and diethylene glycol. Among these, bisphenol A, bisphenol F, and bisphenol S are preferred from the viewpoint of cost, bonding properties, viscosity, and heat resistance. These may be used individually or in combination of two or more. Phenoxy resins have a chemical structure similar to epoxy resins, with a paraphenylene structure and ether bonds as the main backbone, and a structure in which these are linked together in a main chain and hydroxyl groups are arranged in the side chains.

[0070] The weight-average molecular weight of thermoplastic epoxy resins and phenoxy resins is preferably 10,000 to 500,000, more preferably 18,000 to 300,000, and even more preferably 20,000 to 200,000, based on polystyrene equivalent values ​​measured by GPC (gel permeation chromatography). The weight-average molecular weight is calculated from the elution peak positions detected by GPC and is the molecular weight equivalent to standard polystyrene. When the weight-average molecular weight is within the above range, a good balance between thermoplasticity and heat resistance is achieved, and laminates with high heat resistance can be efficiently formed. When the weight-average molecular weight is 10,000 or more, it exhibits excellent heat resistance, and when it is 500,000 or less, it shows high bonding properties when melted or softened.

[0071] If necessary, the thermoplastic film 20 may contain fillers or additives as components other than the resin component, to the extent that they do not impede the purposes of this disclosure.

[0072] Examples of fillers include inorganic fillers and organic fillers. Examples of inorganic fillers include spherical fused silica, metal powders such as iron powder, silica sand, talc, calcium carbonate, mica, acid clay, diatomaceous earth, kaolin, quartz, titanium dioxide, silica, phenolic resin microballoons, and glass balloons. Examples of organic fillers include resin powders.

[0073] If the thermoplastic film 20 contains a filler, the filler content of the thermoplastic film 20 is preferably 50 volume% or less, more preferably 30 volume% or less, even more preferably 20 volume% or less, and most preferably 10 volume% or less, based on the volume of the thermoplastic film 20. The volume of the filler is the value obtained by dividing the mass of the filler contained in the thermoplastic film 20 by the apparent specific gravity of the filler. Based on the volume of the thermoplastic film 20, the resin component content of the thermoplastic film 20 is preferably 10 volume% or more, more preferably 20 volume% or more, even more preferably 30 volume% or more, and particularly preferably 50 volume% or more. In some embodiments, the resin component content of the thermoplastic film 20 is 80 volume% or more, 90 volume% or more, or 99 volume% or more.

[0074] Examples of additives include defoamers, coupling agents such as silane coupling agents, pigments, and tackifying resins. Additives may be used individually or in combination of two or more.

[0075] The additive content of the thermoplastic film 20 is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0076] The thickness of the thermoplastic film 20 is preferably 10 μm to 3 mm, more preferably 20 μm to 1 mm, even more preferably 30 μm to 0.5 mm, particularly preferably 40 μm to 0.2 mm, and most preferably 50 μm to 0.1 mm. By setting the thickness of the thermoplastic film 20 to 3 mm or less, heat can be efficiently supplied to the thermoplastic film 20 from the heating device 14 to quickly develop tack, allowing it to be easily fixed to the substrate 30, and bonding with the second substrate can also be performed in a short time. By setting the thickness of the thermoplastic film 20 to 10 μm or more, high bonding strength can be achieved between the second substrate and the substrate 30.

[0077] The width of the thermoplastic film 20, which is perpendicular to the circumferential direction of the base material 30, can be appropriately determined according to the base material 30.

[0078] The thermoplastic film 20 may be a single layer or a laminate containing multiple layers. It is preferable that the thermoplastic film 20 be a single layer because it is easy to manufacture and provides high bonding strength.

[0079] It is preferable that the thermoplastic film 20 exhibits thermoplasticity at both the contact surface with the pressure roller 13 and the contact surface with the substrate 30. Such a thermoplastic film 20 can be advantageously used as a bonding member for the second substrate.

[0080] The thermoplastic film 20 preferably has a rubber region in its dynamic viscoelastic curve. The rubber region is defined as the region between the glass transition temperature Tg and the melting point Tm in a dynamic viscoelastic curve where the vertical axis is the storage modulus E' and the horizontal axis is temperature. In amorphous thermoplastic resins where the melting point Tm is unclear, the rubber region is defined as the region between the glass transition temperature Tg and the temperature corresponding to the point where the storage modulus E' and the loss modulus E'' intersect, instead of the melting point Tm. In one embodiment, the rubber region corresponds to a temperature range of 100°C to 180°C. A thermoplastic film 20 having a rubber region can be softened or melted while maintaining its shape and exhibiting tack by being heated to the temperature range corresponding to the rubber region. In this state, by pressing the thermoplastic film 20 onto the substrate 30 using a pressure roller 13, the thermoplastic film 20 can be easily fixed to the substrate 30 while suppressing the thermoplastic film 20 from breaking or stretching in undesirable locations.

[0081] The dynamic viscoelastic curve is obtained by performing dynamic viscoelastic measurements on the thermoplastic film 20 as a test specimen using a dynamic viscoelasticity measuring device under the following conditions. Specimen size: Thickness 0.01-1 mm, width 5 mm, length 20 mm Measurement mode: Strain mode Distortion amount: 0.1mm Excitation waveform: sine wave Frequency: 10Hz Measurement temperature: 0-200°C (or until melted) Heating rate: 4°C / min

[0082] The glass transition temperature Tg and melting point Tm of the thermoplastic film 20 are values ​​obtained using a DSC (differential scanning calorimeter). Specifically, 2 mg to 10 mg of the thermoplastic film 20 is weighed, placed in an aluminum pan, and heated from 23°C to over 200°C at a rate of 10°C / min using a DSC (DSC8231 manufactured by Rigaku Corporation) to obtain a DSC curve. The melting peak temperature of the obtained DSC curve (the temperature of the endothermic peak in the DSC curve resulting from melting) is defined as the melting point Tm. If the melting peak temperature cannot be obtained, or if the heat of fusion is 15 J / g or less, the melting point Tm is considered to be the glass transition temperature plus 70°C. The glass transition temperature Tg is defined as the temperature at which the DSC curve begins to decline in the second cycle after heating to 200°C (10°C / min) with a DSC, cooling to below 40°C (10°C / min), and then heating again to 200°C.

[0083] The thermoplastic film 20 preferably exhibits tack at 40°C or above. This improves handling when not heated, and for example, in the case of a continuous film in roll form, it can be easily unwound. On the other hand, since the thermoplastic film 20 that exhibits tack at 40°C or above quickly develops tack when heated by the heating device 14, it can be easily fixed to the substrate 30.

[0084] The method for producing the thermoplastic film 20 is not particularly limited, but for example, a resin composition can be obtained by heating and polymerizing a monomer or oligomer of a bifunctional epoxy compound, a solvent can be added to the obtained resin composition as needed, and the resin composition can be applied to a release film or the like, cured and dried, and pressurized as needed. The thermoplastic film 20 produced by this embodiment has excellent bonding properties. The thermoplastic film 20 can also be produced by rolling or extruding the resin composition. The polymerization reaction may be carried out after applying the monomer or oligomer of the bifunctional epoxy compound to the release film, after removing the solvent and obtaining the film shape, or at both stages.

[0085] The thermoplastic film 20 is heated using the heating device 14. The heating temperature can be appropriately determined considering the tack formation temperature and viscoelastic properties of the thermoplastic film 20, as well as the heat resistance temperature of the material of the base material 30. In an embodiment in which the heating device 14 is located inside the pressure roller 13, the thermoplastic film 20 can be heated by bringing it into contact with the heated pressure roller 13.

[0086] It is preferable to heat the thermoplastic film 20 having a rubbery region to a temperature range corresponding to that rubbery region. This allows the film to soften or melt while maintaining its shape, thereby developing tack. In this state, by pressing the thermoplastic film 20 onto the substrate 30 using the pressure roller 13, the thermoplastic film 20 can be easily fixed to the substrate 30 while suppressing breakage or stretching of the thermoplastic film 20 in undesirable places.

[0087] The thermoplastic film 20 is heated to a temperature of preferably 100°C to 300°C, more preferably 120°C to 250°C, and even more preferably 150°C to 220°C. By heating the thermoplastic film 20 to a temperature of 100°C to 300°C, the thermoplastic film 20 can be easily fixed to the substrate 30 while suppressing the thermoplastic film 20 from tearing or stretching in undesirable places when the thermoplastic film 20 is pressed onto the substrate 30 with the pressure roller 13.

[0088] The thermoplastic film 20 is attached to the base material 30 by pressing the softened or melted thermoplastic film 20 onto the base material 30 using a rotating pressure roller 13. At this time, by rotating the pressure roller 13, the thermoplastic film 20 can be wound around the base material 30 while being fed in the direction of the base material 30's rotation. The base material 30 is attached to a rotatable holder 12 and rotates in conjunction with the rotation of the pressure roller 13 that presses the thermoplastic film 20 onto the base material 30.

[0089] The pressure applied by the pressing roller 13 to the base material 30 is preferably 0.001 MPa to 1 MPa, more preferably 0.01 MPa to 0.5 MPa, and even more preferably 0.05 MPa to 0.2 MPa. By setting the pressure to 0.001 MPa or more, the thermoplastic film 20 can be surely fixed to the base material 30. By setting the pressure to 1 MPa or less, unwanted breakage of the thermoplastic film 20 can be suppressed. The pressure applied by the pressing roller 13 to the base material 30 can be measured by the pressure measuring device 18.

[0090] The peripheral speed of the pressing roller 13 is preferably 0.06 m / min to 6 m / min, more preferably 0.1 m / min to 1 m / min, and even more preferably 0.3 m / min to 0.6 m / min. By setting the peripheral speed to 0.06 m / min or more, peeling of the thermoplastic film 20 from the pressing roller 13 can be assisted and the fixing efficiency can be enhanced. By setting the peripheral speed to 6 m / min or less, the thermoplastic film 20 can be heated to a temperature sufficient for fixing and surely fixed to the base material 30.

[0091] In an embodiment where the thermoplastic film 20 is a continuous film in roll form, it is preferable to control the rotation speed of the pressing roller 13 so that the tension of the thermoplastic film 20 before being attached to the base material 30 is 0.1 N / mm 2 ~2 N / mm 2 At this time, the tension of the thermoplastic film 20 is more preferably 0.2 N / mm 2 ~1 N / mm 2 and even more preferably 0.3 N / mm 2 ~0.5 N / mm 2 That is. By controlling the rotation speed of the pressing roller 13 so that the tension of the thermoplastic film 20 is 0.1 N / mm 2 or more, the occurrence of wrinkles, twists, etc. of the thermoplastic film 20 can be suppressed and the thermoplastic film 20 can be stably supplied. When the tension of the thermoplastic film 20 is 2 N / mm 2By controlling the rotation speed of the pressure roller 13 as follows, unwanted tearing, stretching, etc., of the thermoplastic film 20 can be suppressed. The tension of the thermoplastic film 20 can be measured by the tension detection mechanism 112 as the tension applied to the guide roller 111.

[0092] The base material 30 may be preheated. Preheating the base material 30 suppresses the decrease in tack of the thermoplastic film 20 caused by the temperature drop when the heated thermoplastic film 20 comes into contact with the base material 30, thereby enabling more effective fixing. Preheating is particularly effective when the base material 30 contains a low thermal conductivity material such as resin. Preheating can be performed using the second heating device 16. The preheating temperature of the base material 30 can be appropriately determined considering the heat resistance of the base material 30, and can be, for example, 80°C to 120°C.

[0093] Once the desired amount of thermoplastic film 20 has been supplied, the thermoplastic film 20 is cut using the cutting device 15.

[0094] After attaching the desired amount of thermoplastic film 20 to the substrate 30, the pressure roller 13 is moved from the pressing position to the release position using the moving device 17. Fixation is completed by lowering the temperature of the thermoplastic film 20 and allowing it to solidify. By detaching the substrate 30, to which the thermoplastic film 20 is fixed, from the holding part 12, a laminate is obtained that includes the substrate 30 and the thermoplastic film 20 attached to at least a portion of its outer circumference.

[0095] Methods for solidifying the thermoplastic film 20 include letting it cool at room temperature or cooling it using a cooling device. From the viewpoint of ease of manufacture, letting it cool at room temperature is preferred. In this disclosure, "room temperature" means room temperature in the range of 5°C to 30°C. In this disclosure, "solidified" means solid at 23°C, that is, non-fluid under unpressurized conditions at 23°C.

[0096] The thermoplastic film 20 may be attached to a part of the outer periphery of the substrate 30, or to the entire outer periphery. The thermoplastic film 20 may be attached in two or more layers on a part or all of the outer periphery of the substrate 30.

[0097] [Method for manufacturing a jointed body] One embodiment of the method for manufacturing a bonded body includes joining a second substrate to the thermoplastic film 20 of the laminate manufactured by the above method by insert molding or overmolding.

[0098] Conventional methods can be used for insert molding and overmolding. Specifically, after placing the laminate in the cavity of an insert molding die, resin is injected and filled into the cavity from a resin injection port provided in the die. This bonds the injected resin onto at least a portion of the thermoplastic film 20 of the laminate. This forms an insert molded product in which a base material 30 and a second base material are bonded via the thermoplastic film 20. In overmolding, two or more types of resin are successively injected and bonded onto at least a portion of the thermoplastic film 20 of the laminate, and the second base material is formed to contain two or more types of resin.

[0099] The resin injected in insert molding and overmolding is not particularly limited, but it preferably includes one selected from the group consisting of thermoplastic resins, fiber-reinforced plastics (FRP), and thermosetting resins, and is preferably a thermoplastic resin from the viewpoint of bonding strength, cost, and ease of molding.

[0100] Examples of thermoplastic resins include at least one selected from the group consisting of polyolefins such as polyethylene and polypropylene and their acid-modified products, polystyrene, polymethyl methacrylate, AS resin, ABS resin, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, polyimide, polyamide, polyamide-imide, polyetherimide, polyethersulfone, polyphenylene ether and its modified products, polyphenylene sulfide, polyoxymethylene, polyarylate, polyether ketone, polyetherether ketone, polyether ketone ketone, and thermoplastic epoxy.

[0101] Examples of fiber-reinforced plastics include those containing the above-mentioned thermoplastic resin and reinforcing fibers such as carbon fibers, glass fibers, and cellulose nanofibers.

[0102] Examples of thermosetting resins include at least one selected from the group consisting of epoxy resins, vinyl ester resins, unsaturated polyester resins, phenolic resins, and urethane resins.

[0103] For applications requiring heat resistance, at least one material selected from the group consisting of polycarbonate, glass fiber reinforced polyamide, glass fiber reinforced polybutylene terephthalate, and glass fiber reinforced polyphenylene sulfide is preferred.

[0104] The combination of the material of the base material 30 and the resin from which the second base material is injected is not particularly limited.

[0105] The molding temperature of the resin is preferably 100°C to 400°C, more preferably 150°C to 350°C, and even more preferably 180°C to 300°C. By injection molding in the range of 100°C to 400°C, the thermoplastic film 20 is heated, efficiently deformed and melted, and effectively wets and spreads across the bonding surface, thereby obtaining high bonding strength with the resin.

[0106] By providing a thermoplastic film 20 between the base material 30 and the resin forming the second base material, the base material 30 and the second base material can be joined. The thermoplastic film 20, after the completion of chemical reactions such as polymerization, enables rapid curing by utilizing the phase change between solid and liquid. Therefore, compared to applying a liquid adhesive, by fixing the thermoplastic film 20 to the base material 30 and using it as a joining material, the joining process can be made shorter and simpler, and uneven bonding caused by incomplete application or dripping of the liquid adhesive can be prevented.

[0107] Since the thermoplastic film 20 exhibits thermoplasticity at high temperatures, it can relieve stress at the bonding interface or within the thermoplastic film 20 during thermal cycling, thereby suppressing delamination from the substrate 30 or the second substrate.

[0108] The bonding strength is influenced by numerous factors, including interfacial interactions (e.g., hydrogen bonds or van der Waals forces) between the thermoplastic film 20 and the substrate 30, and between the thermoplastic film 20 and the second substrate, the thickness of the thermoplastic film 20, the molecular weight, chemical structure, mechanical properties, and viscoelastic properties of the polymers constituting the thermoplastic film 20. Therefore, the details of the mechanism by which the bonded structure of this disclosure exhibits excellent bonding strength are not clear. In the bonded structure of this disclosure, the state or properties of the interface between the thermoplastic film 20 and the substrate 30, and the interface between the thermoplastic film 20 and the second substrate, are difficult to analyze because they are due to extremely thin chemical structures at the nanometer level or less. For this reason, it is impossible or impractical with current art to describe the bonded structure of this disclosure in a way that distinguishes it from a bonded structure that does not use the thermoplastic film 20 by specifying the state or properties of the above-mentioned interfaces.

[0109] This disclosure can be used for bonding, insert molding, and overmolding of various parts used in automobiles, home appliances, machine tools, and the like. [Explanation of symbols]

[0110] 10 Thermoplastic film application device 11. Film feeding device 111 Guide roller 112 Tension detection mechanism 12 Holding part 13 Pressure roller 14 Heating device 15 Cutting device 16 Second heating device 17 Mobile device 18 Pressure measuring device 19 Guide Plate 20 Thermoplastic film 21 rolls 30 Base material

Claims

1. A film supply device that supplies thermoplastic film, A holding part that holds a cylindrical or columnar base material having a central axis so as to be rotatable around the central axis, The surface has release properties, and a pressure roller is positioned opposite the substrate, A heating device for heating the thermoplastic film, A cutting device for cutting the thermoplastic film, A thermoplastic film application apparatus equipped with the following features.

2. The thermoplastic film application apparatus according to claim 1, wherein the heating device is a device for heating the pressure roller, and the thermoplastic film is heated by the heated pressure roller.

3. The thermoplastic film application apparatus according to claim 1 or 2, wherein the pressure roller is a silicone rubber roller.

4. The thermoplastic film application apparatus according to claim 1 or 2, further comprising a second heating device for preheating the substrate.

5. The thermoplastic film application apparatus according to claim 1 or 2, further comprising a moving device for moving the pressure roller between a pressing position in which the thermoplastic film is pressed against the substrate and an open position in which no pressure is applied to the thermoplastic film.

6. The thermoplastic film bonding apparatus according to claim 5, further comprising a pressure measuring device for measuring the pressure applied to the pressure roller at the aforementioned bonding position.

7. The thermoplastic film application apparatus according to claim 1 or 2, wherein the thermoplastic film installed in the film supply device is a continuous film in roll form, and the film supply device is a film unwinding device equipped with guide rollers and a tension detection mechanism.

8. The thermoplastic film application apparatus according to claim 1 or 2, wherein both the contact surface of the thermoplastic film with the pressure roller and the contact surface with the substrate exhibit thermoplastic properties.

9. A thermoplastic film application system comprising a thermoplastic film application apparatus according to claim 1 or 2, and a thermoplastic film in which both the contact surface with the pressure roller and the contact surface with the substrate are thermoplastic.

10. A method for manufacturing a laminate comprising a cylindrical or columnar base material having a central axis and a thermoplastic film attached to at least a portion of the outer circumference of the base material, To provide a thermoplastic film application apparatus according to claim 1 or 2, Attaching the substrate to the holding part, The thermoplastic film is supplied from the film supply device between the pressure roller and the substrate. Heating the thermoplastic film using the heating device, and The thermoplastic film is attached to the substrate by pressing the softened or melted thermoplastic film onto the substrate using the rotating pressure roller. Methods that include...

11. The method according to claim 10, wherein the thermoplastic film has a rubber region in its dynamic viscoelastic curve, and the method comprises heating the thermoplastic film to a temperature range corresponding to the rubber region of the thermoplastic film.

12. The method according to claim 10, wherein both the contact surface of the thermoplastic film with the pressure roller and the contact surface with the substrate exhibit thermoplastic properties.

13. The method according to claim 10, wherein the thermoplastic film exhibits tack at 40°C or higher.

14. The method according to claim 10, wherein the thickness of the thermoplastic film is 10 μm to 3 mm.

15. The method according to claim 10, further comprising preheating the substrate.

16. The method according to claim 10, further comprising pre-treating the surface of the substrate.

17. The thermoplastic film is a continuous film in roll form, and the tension of the thermoplastic film before it is attached to the substrate is 0.1 N / mm². ２ ~2N / mm ２ The method according to claim 10, comprising controlling the rotation speed of the pressure roller to such an extent.

18. The method according to claim 10, wherein the thermoplastic film mainly comprises an amorphous thermoplastic resin.

19. The method according to claim 18, wherein the amorphous thermoplastic resin comprises a thermoplastic epoxy resin which is a polymer of (a) a difunctional epoxy resin monomer or oligomer and (b) a difunctional compound having two identical or different functional groups selected from the group consisting of phenolic hydroxyl groups, carboxyl groups, mercapto groups, isocyanate groups and cyanate ester groups.

20. The method according to claim 18, wherein the amorphous thermoplastic resin comprises a phenoxy resin which is a polyhydroxy polyether synthesized from a bisphenol compound and epichlorohydrin.

21. The method according to claim 18, wherein the thermoplastic film comprises an amorphous thermoplastic resin having an epoxy equivalent of 1,600 g / eq. or more, or does not contain epoxy groups.

22. A method for producing a bonded body, comprising bonding a second substrate to the thermoplastic film of a laminate produced by the method of claim 10 by insert molding or overmolding.

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