JP2019171620A - Method of joining thermoset resin member, thermoset resin member used in the same, and joined body - Google Patents

Abstract

To provide a method of joining a thermoset resin member capable of attaining joining between a thermoset resin member and another member with more than enough bonding strength even in a case in which the thermoset resin member is used.SOLUTION: A method of joining a thermoset resin member of this invention is a method according to a thermo-pressure-type joining method including: overlapping the thermoset resin member containing reinforcing fibers onto another member via thermoplastic resin; softening the thermoplastic resin by applying heat and pressure; and joining the thermoset resin member and the other member; in which the thermoset resin member that includes the reinforcing fibers whose exposing ratio at a joining surface with the other member is 2% or higher is used as the thermoset resin member.SELECTED DRAWING: None

Description

  The present invention relates to a thermosetting resin member joining method, a thermosetting resin member used in the method, and a joined body.

  Conventionally, weight reduction is required in the fields of automobiles, railway vehicles, airplanes, and the like. For example, in the field of automobiles, the use of high-tensile materials has made it possible to make steel sheets thinner, aluminum alloy materials have been used as substitutes for steel materials, and resin materials have also been increasingly used. In these fields, development of joining technology for metal members and resin members is important not only for reducing the weight of the car body, but also for increasing the strength and rigidity of the joining members and improving productivity. is there.

  So far, for example, a so-called friction stir welding (FSW) method has been proposed as a method for joining a metal member and a resin member. As shown in FIG. 11, the friction stir welding method is a method in which a metal member 511 and a resin member 512 are overlapped, and the rotary tool 516 is rotated and pressed against the metal member 511 to generate frictional heat. In this method, the resin member 512 is melted and then solidified to join the metal member 511 and the resin member 512 (for example, Patent Documents 1 and 2). However, when a thermosetting resin member is used as the resin member, since the resin member is not melted by heat, it has been a problem that bonding cannot be achieved.

  In view of this, a technique has been disclosed in which a thermoplastic resin is interposed between the thermosetting resin member and the metal member to achieve these joining (Patent Document 3), but sufficient joining strength can be obtained. There wasn't. For this reason, a method of laminating a thermoplastic resin on the outermost surface of the thermosetting resin member precursor and joining it to a metal member is conceivable, but it is necessary to laminate the thermoplastic resin before the thermosetting resin is completely cured. Yes, the process was complicated.

Japanese Patent Laid-Open No. 2017-042972 JP 2017-104885 A JP 2017-177465 A

  Even if the inventors of the present invention adjust the surface roughness of the thermosetting resin member when a thermoplastic resin is interposed between the thermosetting resin member and the metal member, sufficient bonding strength is still obtained. I found no. Specifically, in the prior art, by adjusting the surface roughness of the thermosetting resin member, the anchor effect due to the unevenness of the surface of the resin itself can be expected, and the bonding surface area increases due to the increase in the surface area of the resin itself. The strength was thought to increase sufficiently. However, sufficient bonding strength could not be obtained even by adjusting the surface roughness of the thermosetting resin member.

  When a thermosetting resin member is used, the problem that sufficient bonding strength cannot be obtained is not only when the thermosetting resin member and the metal member are bonded, but also when the thermosetting resin members are bonded to each other and with the thermosetting resin member. It also occurred at the time of joining with the thermoplastic resin member.

  In addition, when a thermosetting resin member is used, the problem that sufficient bonding strength cannot be obtained is not only the friction stir welding method, but also the ultrasonic heating bonding method, laser heating bonding method, resistance heating bonding method, induction heating bonding method, etc. This also occurred in other hot-pressure bonding methods.

  It is an object of the present invention to provide a method for joining thermosetting resin members that can achieve joining of the thermosetting resin member and other members with more sufficient bonding strength even when a thermosetting resin member is used. To do.

The present invention
The thermosetting resin member including the reinforcing fiber and another member are overlapped with each other through the thermoplastic resin, and heat and pressure are applied to soften the thermoplastic resin and the thermosetting resin member and the other member. A thermosetting resin member joining method by a hot-pressure joining method for joining members,
The present invention relates to a thermosetting resin member joining method using a thermosetting resin member having an exposure rate of 2% or more of the reinforcing fibers on the joining surface with the other member as the thermosetting resin member.

  According to the bonding method of the present invention, even when a thermosetting resin member is used, the bonding between the thermosetting resin member and another member can be achieved with more sufficient bonding strength.

It is a schematic diagram which shows an example of a part of friction stir welding apparatus suitable for the joining method of the metal member and thermosetting resin member concerning this invention. It is an enlarged view of the front-end | tip part of an example of the rotation tool as a press member used for the joining method of this invention. It is a schematic sectional drawing for demonstrating an example of the preheating process of this invention. It is a schematic sketch of the edge part of an example of the thermosetting resin member used for the joining method of the present invention. It is an example of the photograph of the several area | region in which the fiber exposure process was carried out in the thermosetting resin member surface used for the joining method of this invention. It is a schematic sectional drawing for demonstrating an example of the pushing stirring process of this invention, a stirring maintenance process, and a holding process. It is the schematic for demonstrating the measuring method of the joint strength in an Example. The relationship between the fiber exposure rate of the thermosetting resin member in an Example and the joint strength of a joined body is shown. The relationship between the fiber exposure rate of the thermosetting resin member in an Example and the joint strength of a joined body is shown. The relationship between surface roughness Ra of the thermosetting resin member in an Example and the joint strength of a joined body is shown. It is this schematic sectional drawing for demonstrating the joining method of the metal member and resin member in a prior art.

[Method of joining thermosetting resin members]
The method for joining thermosetting resin members according to the present invention includes interposing a thermoplastic resin between a thermosetting resin member and another member, and softening (specifically, melting and solidifying) the thermoplastic resin, thereby thermosetting resin. The joining of a member and another member is achieved. The thermosetting resin member joining method according to the present invention uses a thermosetting resin member, which will be described later, and is achieved by softening a thermoplastic resin interposed between the thermosetting resin member and another member. As long as it is not particularly limited, any hot-pressure bonding method may be used.

  The hot-pressure bonding method is a method in which heat is applied by the pressing member or another means while applying pressure by the pressing member. Specific examples of the hot-pressure bonding method include a friction stir welding method, an ultrasonic heating bonding method, a laser heating bonding method, a resistance heating bonding method, an induction heating bonding method, and the like. Preferably, a friction stir welding method and an induction heating welding method are employed.

  As will be described in detail later, the friction stir welding method is a method in which a thermosetting resin member and other members (particularly metal members) are overlapped with each other via a thermoplastic resin, and a rotary tool as a pressing member is rotated. In this method, frictional heat is generated by locally pressing the other member, and the thermoplastic resin is softened and melted by the frictional heat, and then solidified and joined.

  The ultrasonic heating bonding method is a method in which a thermosetting resin member and another member (particularly a metal member) are overlapped, and while pressing the other member with the pressing member, ultrasonic vibration is caused in the pressing member and the other member. In this method, the thermoplastic resin is softened and melted by frictional heat between another member generated by the vibration and the thermosetting resin member, and then solidified and joined.

  The laser heat bonding method is a method in which a thermosetting resin member and another member (particularly a metal member) are overlapped and heat is applied by irradiating the other member with a laser in a state in which these are constrained by pressing with a pressing member. In this method, the thermoplastic resin is softened and melted with this heat and then solidified and joined. As the laser, a YAG laser, a fiber laser, a semiconductor laser, or the like is used.

  The resistance heating bonding method refers to heat generated by directly applying a current to another member in a state where a thermosetting resin member and another member (particularly a metal member) are overlapped and constrained by pressurization by a pressing member. In this method, the thermoplastic resin is softened and melted and then solidified and joined.

  The induction heating joining method is a state in which a thermosetting resin member and other members (particularly metal members) are superposed and restrained by pressurization by a pressing member, and an induction current is generated in the other members by electromagnetic induction. The thermoplastic resin is softened and melted with heat generated by the current, and then solidified and joined.

  Hereinafter, the joining method of the present invention employing the friction stir welding method will be described in detail with reference to the drawings. As long as the thermosetting resin member described later is used and joining is achieved by softening the thermoplastic resin between the thermosetting resin member and the other member, the above-described other joining methods can be used. It is clear that an effect can be obtained. It should be noted that the various elements shown in the drawings are merely schematically shown for understanding of the present invention, and the dimensional ratio and appearance may differ from the actual ones. The “vertical direction”, “left / right direction”, and “front / back direction” used directly or indirectly in the present specification correspond to directions corresponding to the vertical direction, left / right direction, and front / back direction in the drawing. Unless otherwise specified, in these drawings, common reference numerals indicate the same members, parts, or regions.

[Method of joining thermosetting resin member and other members by friction stir welding method]
The joining method (friction stir welding method) of the present invention will be described in detail.

(1) Joining Device First, FIG. 1 is a diagram schematically showing an example of a part of a friction stir welding device suitable for carrying out the joining method of the present invention. A friction stir welding device 1 shown in FIG. 1 is configured as a device for friction stir welding a thermosetting resin member 12 and another member 11 and includes a columnar rotary tool 16 as a pressing member. .

  As shown in the figure, the rotary tool 16 is not shown in the figure with respect to the workpiece 10 overlaid with a thermoplastic resin (not shown) so that the other member 11 is on top and the thermosetting resin member 12 is on the bottom. The drive source moves downward as indicated by an arrow A2 while rotating around the central axis X (see FIG. 2) of the rotary tool 16 as indicated by an arrow A1. At this time, the rotary tool 16 applies pressure in the pressing region P (the pressing scheduled region) on the surface of the other member 11. Friction heat is generated by the pressing of the rotary tool 16, and the frictional heat is conducted to the thermoplastic resin, so that the thermoplastic resin is softened and melted, and then the molten resin is solidified. As a result, the other member 11 and the resin member 12 are joined.

  FIG. 2 is an enlarged view of the distal end portion of the rotary tool 16. In FIG. 2, the right half shows the appearance of the rotary tool 16, and the left half shows a cross section. As shown in FIG. 2, the columnar rotary tool 16 has a pin portion 16 a and a shoulder portion 16 b at the distal end portion (lower end portion in FIG. 2). The shoulder portion 16 b is a portion at the tip of the rotary tool 16 including the circular tip surface of the rotary tool 16. In particular, the shoulder portion 16b may refer to a circular tip surface (shoulder surface) of the rotary tool 16. The pin portion 16a is a cylindrical portion having a smaller diameter than the shoulder portion 16b, which protrudes outwardly (downward in FIG. 2) from the circular tip surface of the rotary tool 16 on the central axis X of the rotary tool 16. is there. The pin portion 16a is for positioning the rotating tool 16 when the rotating tool 16 that is rotating is first brought into contact with the workpiece 10 and pressed. That is, the rotating tool 16 has a shoulder portion 16b including the circular tip surface of the rotating tool 16 at the tip portion, and a smaller diameter than the shoulder portion 16b projecting outward from the circular tip surface of the rotating tool 16. The cylindrical pin portion 16a is provided.

  The material of the rotary tool 16 and the dimensions of each part are mainly set according to the metal type of the other member 11 pressed by the rotary tool 16. For example, when the other member 11 is made of an aluminum alloy, the rotary tool 16 is made of tool steel (for example, SKD61), the diameter D1 of the shoulder portion 16b is 10 mm, the diameter D2 of the pin portion 16a is 2 mm, and the pin portion 16a The protrusion length h is set to 0.5 mm. For example, when the other member 11 is made of steel, the rotary tool 16 is made of silicon nitride, PCBN (cubic boron nitride sintered body) or the like, the diameter D1 of the shoulder portion 16b is 10 mm, and the diameter of the pin portion 16a. D2 is set to 3 mm, and the protruding length h of the pin portion 16a is set to 0.5 mm. Needless to say, these are merely examples, and the present invention is not limited thereto. For example, the diameter D1 of the shoulder portion 16b is usually 5 to 30 mm, preferably 5 to 15 mm, but is not limited thereto.

  Below the rotary tool 16, a cylindrical receiving member 17 having the same diameter as the rotary tool 16 or a larger diameter than the rotary tool 16 is arranged coaxially with the rotary tool 16. The receiving member 17 is moved upward with respect to the work 10 as shown by an arrow A3 by a driving source (not shown). The upper end surface of the receiving member 17 abuts on the lower surface of the workpiece 10 (more specifically, the lower surface of the resin member 12) by the time the rotating tool 16 starts pressing the workpiece 10 at the latest. The support 17 sandwiches the workpiece 10 between the rotary tool 16 and supports the workpiece 10 from below against the pressing force during a pressing period by the rotary tool 16, that is, during friction stir welding. Note that the receiving tool 17 does not necessarily have to be moved in the direction of the arrow A3, and a method of moving the rotary tool 16 in the direction of the arrow A2 after placing the workpiece 10 on the receiving tool 17 can also be adopted.

  The friction stir welding apparatus 1 is attached to a drive control device (not shown) composed of an articulated robot or the like. The coordinate positions of the rotary tool 16 and the receiving tool 17, the rotational speed (rpm) of the rotary tool 16, the pressure (N), the pressurization time (second), and the like are appropriately controlled by the drive control device. Although not shown in FIG. 1, the friction stir welding apparatus 1 fixes a workpiece 10 in advance and spacers, clamps, and the like for preventing other members 11 from lifting when the rotary tool 16 is pressed. The jig is equipped.

(2) Thermoplastic Resin The thermoplastic resin 50 (see FIG. 3) is a so-called intermediate adhesive layer that mediates bonding between the thermosetting resin member 12 and the other member 11. Joining of the other member 11 and the resin member 12 is achieved by melting of the thermoplastic resin 50 by the applied heat and solidification by subsequent cooling.

  The thermoplastic resin 50 may have any form as long as it is interposed between the other member 11 and the resin member 12. The thermoplastic resin may have, for example, the form of a sheet, the form of a film formed on the surface of another member 11, the form of a film formed on the surface of the resin member 12, or a composite form thereof. The form of the sheet is a thin plate shape that is not attached to the other member 11 or the resin member 12 and can be an object of the transaction independently, and hot pressing a thermoplastic resin. Can be formed. The form of the film formed on the surface of the other member 11 or the surface of the resin member 12 is a thin film shape formed by adhering to the surface of the other member 11 or the surface of the resin member 12, and a solution of a thermoplastic resin or It can be formed by applying the dispersion to the surface and drying. That the thermoplastic resin has a composite form means that the thermoplastic resin is interposed between the other member 11 and the resin member 12 in two or more of the above forms. FIG. 3 is a schematic cross-sectional view for explaining an example of a preheating process to be described later, and is a cross-sectional view when the XX cross section in FIG. 1 is viewed in the arrow direction.

  The kind of thermoplastic resin is not particularly limited, and any polymer having thermoplasticity can be used. Among these, a thermoplastic polymer used in the field of automobiles, particularly a thermoplastic polymer having a functional group is preferably used. Since the thermoplastic resin interposed between the other member 11 and the resin member 12 has a functional group, it is between the thermoplastic resin and the resin member 12 and between the thermoplastic resin and the other member 11 at the time of joining. Thus, the interaction further works, and the bonding strength can be further improved.

  The functional group that the thermoplastic polymer preferably has is a group containing one or more atoms selected from the group consisting of an oxygen atom, a nitrogen atom, a fluorine atom, and a sulfur atom. A more preferred functional group contains at least an oxygen atom and / or a nitrogen atom, and more preferably contains at least an oxygen atom.

  Specific examples of such a functional group include, for example, a carboxyl group (—COOH), a hydroxyl group (—OH), an amide bond group (—CO—NH—), an ester bond group (—CO—O—), an ether group. (—O—), thioether group (—S—), carboxylate group (—COOR (wherein R is an alkyl group having 1 to 3 carbon atoms)), fluorine atom (—F), urethane bonding group (—NH—CO—O—) and carbonate groups (—O—CO—O—). The functional group may be one or more groups selected from the group consisting of these groups. A preferred functional group is one or more selected from the group consisting of a carboxyl group (—COOH), a hydroxyl group (—OH), an amide bond group (—CO—NH—), and an ester bond group (—CO—O—). It is a group. A more preferred functional group is at least one group selected from the group consisting of a carboxyl group (—COOH), a hydroxyl group (—OH), and an amide bond group (—CO—NH—). Further preferred functional groups are one or more groups selected from the group consisting of a carboxyl group (—COOH) and an amide bond group (—CO—NH—). The most preferred functional group is an amide bond group (—CO—NH—). The ester bond group does not include a carboxyl group, a carboxylate group, a urethane bond group, or a carbonate group.

  The functional group may constitute at least a part of the main chain and / or side chain of the thermoplastic polymer.

  Thermoplastic polymers usually contain hydrogen atoms in the main chain and / or side chain in addition to the above functional groups. For this reason, when the other member 11 is a metal member, the interaction by a hydrogen bond acts between the said hydrogen atom of a thermoplastic polymer, and the oxygen atom of the metal oxide of the other member 11 surface. On the other hand, since the thermosetting resin described later constituting the resin member 12 usually has at least a hydrogen atom and an oxygen atom, an interaction due to hydrogen bonding works between these atoms and the functional group of the thermoplastic polymer. As a result, the bonding strength between the other member 11 and the resin member 12 is further improved.

  Specific examples of the thermoplastic polymer having a functional group include, for example, acid-modified polyolefin, thermoplastic epoxy polymer, polyamide, vinyl acetate-containing polymer, polyester, poly (meth) acrylate, polycarbonate, polyurethane, polyether, liquid crystal polymer, Examples include fluorine-containing polymers. The thermoplastic polymer does not necessarily have a functional group, and may be, for example, a polyolefin. The thermoplastic polymer may be used in combination of one or more of these polymers. From the viewpoint of further improving the bonding strength, preferred thermoplastic polymers are acid-modified polyolefins, thermoplastic epoxy polymers, polyamides, vinyl acetate-containing polymers and mixtures thereof. More preferable thermoplastic polymers from the same viewpoint are acid-modified polyolefins, thermoplastic epoxy polymers, polyamides, and mixtures thereof. Further preferred thermoplastic polymers from the same viewpoint are acid-modified polyolefins, polyamides, and mixtures thereof. The most preferred thermoplastic polymer from the same viewpoint is polyamide.

  The acid-modified polyolefin is a thermoplastic polymer having a carboxyl group in the side chain. The acid-modified polyolefin means an acid-modified product of polyolefin. Specific examples of the acid-modified polyolefin include a copolymer of a carboxyl group-containing monomer and an olefin monomer. Examples of the carboxyl group-containing monomer include unsaturated carboxylic acids having 3 to 8, preferably 3 to 6, carbon atoms (including carbon atoms of the carboxyl group), and specific examples thereof include acrylic acid, methacrylic acid, maleic acid, and anhydrous. Examples include maleic acid, fumaric acid, citraconic acid, and citraconic anhydride. Examples of the olefinic monomer include unsaturated hydrocarbons having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and specific examples thereof include ethylene, propylene, butylene and the like. The ratio of the carboxyl group-containing monomer to the total monomer constituting the acid-modified polyolefin is 10 mol% or more, particularly 10 to 90 mol%, preferably 30 to 70 mol%. In the present specification, unless otherwise specified, when the compound has a carboxyl group, the number of carbon atoms of the carboxyl group is included.

  The thermoplastic epoxy polymer is a thermoplastic polymer having a hydroxy group in the side chain. The thermoplastic epoxy polymer is a polyaddition reaction product of a diepoxy compound and a diol compound. The diepoxy compound is not particularly limited as long as it is a compound having two epoxy groups in one molecule. The diepoxy compound is preferably an aromatic diepoxy compound. Specific examples of the aromatic diepoxy compound include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, brominated bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, and bisphenol AF diglycidyl ether. 4,4′-dihydroxybiphenyl diglycidyl ether and the like. The diol compound is not particularly limited as long as it is a compound having two hydroxyl groups in one molecule. The diol compound is preferably an aliphatic diol compound. Examples of the aliphatic diol compound include saturated aliphatic diol compounds having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples thereof include, for example, ethylene glycol, 1,2-propanediol, and 1,3-propane. Examples include diol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, and the like. The diepoxy compound and the diol compound can be used alone or in combination of two or more.

  Polyamide is a thermoplastic polymer having an amide bond group in the main chain. Polyamide is a polycondensation reaction product of a dicarboxylic acid compound and a diamine compound or a ring-opening polymerization product of a cyclic amide compound. A cyclic amide compound may be used in combination as a reaction monomer of the former polycondensation reaction product. The dicarboxylic acid compound is not particularly limited as long as it is a compound having two carboxyl groups in one molecule. The dicarboxylic acid compound is preferably an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid. Examples of the aliphatic dicarboxylic acid include saturated aliphatic dicarboxylic acids having 3 to 12 carbon atoms, preferably 4 to 10 carbon atoms. Specific examples thereof include, for example, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and suberin. Examples include acids, azelaic acid, and sebacic acid. The aromatic dicarboxylic acid preferably has 8 to 12 carbon atoms, and specific examples thereof include terephthalic acid, isophthalic acid, 1,8-naphthalenedicarboxylic acid and the like. The diamine compound is not particularly limited as long as it is a compound having two amino groups in one molecule. The diamine compound is preferably an aliphatic diamine or an aromatic diamine. Examples of the aliphatic diamine include saturated aliphatic diamines having 2 to 12 carbon atoms, preferably 4 to 10 carbon atoms. Specific examples thereof include ethylene diamine, propylene diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexa Examples include methylenediamine, nonanediamine, 2-methyl-1,5-pentanediamine, and the like. Aromatic diamines include those having 6 to 12 carbon atoms, preferably 6 to 8 carbon atoms, and specific examples thereof include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, metaxylylenediamine, and the like. Can be mentioned. Examples of the cyclic amide compound include those having 4 to 14 carbon atoms, and specific examples thereof include ε-caprolactam, undecane lactam, lauryl lactam, and the like. The dicarboxylic acid compound, the diamine compound and the cyclic amide compound can be used alone or in combination of two or more. Preferable specific examples of the polyamide include PA6, PA66, PA11, PA12, PA6T, PA9T, and MXD6.

  The vinyl acetate-containing polymer is a thermoplastic polymer having an ester bond group in the side chain. The vinyl acetate-containing polymer is a copolymer of vinyl acetate and an olefin monomer. Examples of the olefinic monomer include unsaturated hydrocarbons having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and specific examples thereof include ethylene, propylene, butylene and the like. The ratio of vinyl acetate to all monomers constituting the vinyl acetate-containing polymer is 10 mol% or more, particularly 10 to 90 mol%, preferably 30 to 70 mol%.

  Polyester is a thermoplastic polymer having an ester bond group in the main chain. Polyester is a polycondensation reaction product of a diol compound and a dicarboxylic acid compound or a polycondensation reaction product of a monohydroxymonocarboxylic acid compound. A monohydroxymonocarboxylic acid compound may be used in combination as a reaction monomer of the former polycondensation reaction product. The diol compound is not particularly limited as long as it is a compound having two hydroxyl groups in one molecule. Examples of the diol compound include those having 2 to 10 carbon atoms, and specific examples thereof include ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,4-cyclohexanedimethanol and the like. . The dicarboxylic acid compound is not particularly limited as long as it is a compound having two carboxyl groups in one molecule. Examples of the dicarboxylic acid compound include those having 4 to 14 carbon atoms. Specific examples thereof include terephthalic acid and 2,6-naphthalenedicarboxylic acid. The monohydroxymonocarboxylic acid compound is not particularly limited as long as it is a compound having one carboxyl group and one hydroxyl group in one molecule. Examples of the monohydroxymonocarboxylic acid compound include those having 2 to 8 carbon atoms, and specific examples thereof include lactic acid.

  An alkyl poly (meth) acrylate is a thermoplastic polymer having a carboxylate group in the side chain. Examples of the alkyl group include an alkyl group having 1 to 3 carbon atoms. Preferable specific examples of the alkyl poly (meth) acrylate include, for example, methyl poly (meth) acrylate (PMMA), ethyl poly (meth) acrylate, and the like.

  Polycarbonate is a thermoplastic polymer having carbonate groups in the main chain. Polycarbonate is a polymer of bisphenol A and phosgene or diphenyl carbonate.

  Polyurethane is a thermoplastic polymer having a urethane bond group in the main chain. Polyurethane is a polymer of a diol compound and a diisocyanate compound, for example.

  The polyether is a thermoplastic polymer having an ether bond group in the main chain, and may have a thioether bond group instead of or in addition to the ether bond group. The polyether may further have a carbonyl group. Preferable specific examples of the polyether include, for example, polyphenylene ether (PPE), polyacetal (POM), polyphenylene sulfide (PPS), polyether ether ketone (PEEK) and the like.

  The liquid crystal polymer is a thermoplastic polymer having an ester bond group in the main chain.

  Examples of the polyolefin that can be used as the thermoplastic polymer include homopolymers or copolymers of olefinic monomers such as ethylene, propylene, and butylene.

  The thermoplastic polymer is preferably a polymer having the functional group in the side chain from the viewpoint of further improving the bonding strength. A more preferable thermoplastic polymer is a polymer in which a monovalent functional group among the functional groups is directly bonded to a carbon atom of the main chain as a side chain. Examples of such thermoplastic polymer include acid-modified polyolefin and thermoplastic epoxy polymer.

  The molecular weight of the thermoplastic polymer is not particularly limited as long as the thermoplastic polymer can be melted at the time of joining. For example, the molecular weight may be such that the melting point is 140 to 350 ° C, particularly 140 to 300 ° C.

  The thermoplastic resin may further contain, for example, fillers such as carbon fibers and glass fibers, and additives such as plasticizers.

  Even when the thermoplastic resin is used in any form described above, the thermoplastic resin is preferably interposed between the other member 11 and the resin member 12 with a thickness of 10 to 600 μm, particularly 100 to 550 μm. This thickness is the thickness before joining. If the thermoplastic resin is too thick, it will be difficult to melt and will not contribute sufficiently to the joining. If the thermoplastic resin is too thin, the amount of melting will be insufficient and will not contribute sufficiently to the joining. When the thermoplastic resin is used in a composite form among the above forms, the total thickness thereof may be within the above range.

  The arrangement and dimensions (dimensions other than the thickness) of the thermoplastic resin are not particularly limited as long as the joining between the other member 11 and the resin member 12 is achieved. Usually, the thermoplastic resin 50 is the other member 11 and the resin member. 12 should just exist in a joining plan area | region. In the friction stir welding method, the arrangement and dimensions (dimensions other than the thickness) of the thermoplastic resin 50 are usually such that the thermoplastic resin 50 is at least on the other member 11 side surface 121 of the resin member 12 as shown in FIG. Any arrangement and dimensions that cover the region 112 directly below may be used. Specifically, when the diameter of the rotary tool 16 is D1, the thermoplastic resin 50 is usually a circular sheet having a diameter of D1 to 2 × D1, preferably 1.1 × D1 to 1.5 × D1. And is used so that its center is located on the axis of the rotating tool. The region 112 directly below is a region directly below the rotary tool 16 on the other member 11 side surface 121 of the resin member 12. 3 corresponds to, for example, the region P ′ in FIG. 4 in plan view. The plan view is a state when an object (for example, the workpiece 10 or a joined body obtained by joining) is placed and viewed from directly above in the thickness (height) direction. It is consent. The placement is placement with the surface (plane) having the maximum area constituting the appearance of the object (for example, the workpiece 10 or the joined body) as the bottom surface. FIG. 4 is a schematic sketch of an end portion of an example of a thermosetting resin member used in the bonding method of the present invention.

(3) Resin member The resin member 12 is a thermosetting resin member containing reinforcing fibers. The thermosetting resin member means a cured resin member that is not melted by heat. The thermosetting resin member may be cured by heat, or may be cured by light (particularly ultraviolet rays). Accordingly, the thermosetting resin member may be a cured product composed of a thermosetting resin, or may be a cured product composed of a photocurable resin. From the viewpoint of productivity, the thermosetting resin member is preferably a cured product composed of a thermosetting resin. The thermosetting resin and the photocurable resin mean a resin having a property of being cured by heat and light, respectively. Curing means that a network structure is formed three-dimensionally.

  Examples of the thermosetting resin include a thermosetting epoxy resin, a thermosetting phenol resin, a thermosetting melamine resin, and a thermosetting urea resin. A preferable thermosetting resin from the viewpoint of further improving the bonding strength is a thermosetting epoxy resin.

The thermosetting epoxy resin includes an epoxy resin and a curing agent.
The epoxy resin is not particularly limited as long as it is a compound having two or more epoxy groups. Examples of the epoxy resin include bisphenol A type, bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol S type, bisphenol AF type, and biphenyl type epoxy compounds, polyalkylene Difunctional glycidyl ether type epoxy resin such as glycol type, alkylene glycol type epoxy compound, epoxy compound having naphthalene ring, epoxy compound having fluorene group; phenol novolak type, orthocresol novolak type, trishydroxyphenylmethane type, Polyfunctional glycidyl ether type epoxy resin such as tetraphenylolethane type; Glycidyl ester type epoxy resin of synthetic fatty acid such as dimer acid; N, N, N ′, N′-tetraglyce Aromatic epoxy resins having a glycidylamino group such as dildiaminodiphenylmethane (TGDDM), tetraglycidyl-m-xylylenediamine, triglycidyl-p-aminophenol, N, N-diglycidylaniline; having a tricyclodecane ring An epoxy compound (for example, an epoxy compound obtained by a production method in which epichlorohydrin is reacted after polymerizing cresols or phenols such as dicyclopentadiene and m-cresol) and the like. Moreover, for example, an epoxy resin having a sulfur atom in the main chain of the epoxy resin, such as Flep 10 manufactured by Toray Fine Chemical Co., Ltd. can be mentioned. The epoxy resins can be used alone or in combination of two or more. Among these, bisphenol A type and / or bisphenol F type are preferable. The amount of bisphenol A-type epoxy resin and / or bisphenol F-type epoxy resin is preferably greater than 0 parts by mass and less than or equal to 100 parts by mass, more than 0 parts by mass and less than or equal to 70 parts by mass. More preferably. In the present invention, the contents of bisphenol A type epoxy resin and bisphenol F type epoxy resin are additive amounts.

  Curing agents that can be included with the epoxy resin include polyamines, acid anhydrides or mixtures thereof. The polyamine is not particularly limited. For example, aromatic polyamines such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane: ethylenediamine, propylene Diamine, Butylenediamine, Diethylenetriamine, Triethylenetetramine, Tetraethylenepentamine, Pentaethylenehexamine, Hexamethylenediamine, Trimethylhexamethylenediamine, 1,2-propanediamine, Iminobispropylamine, Methyliminobispropylamine, DuPont Japan Products such as MPMD aliphatic polyamines: N-aminoethylpiperazine, 3-butoxyisopropylamine, etc. Polyether skeleton diamines represented by monoamines having a ether bond and products of Sun Techno Chemical Co., Ltd. product Jeffamine EDR148: isophoronediamine, 1,3-bisaminomethylcyclohexane, 1-cyclohexylamino-3-aminopropane, 3-aminomethyl- Alicyclic polyamines such as 3,3,5-trimethylcyclohexylamine: diamine having a norbornane skeleton typified by Mitsui Chemicals, Inc. NBDA: Polyamidoamine having an amino group at the molecular end of the polyamide: 2,5-dimethyl-2,5 -Jefamine D230, a product of Sun Techno Chemical Co., which has hexamethylenediamine, mensendiamine, 1,4-bis (2-amino-2-methylpropyl) piperazine, polypropylene glycol (PPG) as a skeleton 400 or the like may be mentioned as specific examples. Examples of acid anhydrides include trimellitic acid anhydride, pyromellitic acid anhydride, hexahydrophthalic acid anhydride, methylhexahydrophthalic acid anhydride, nadic acid anhydride, methyl nadic acid anhydride, tetrahydrophthalic acid anhydride. Methyltetrahydrophthalic anhydride, dodecenyl succinic anhydride (DSA), and the like.

The thermosetting phenolic resin contains phenol and / or a derivative thereof and formaldehyde.
The thermosetting melamine resin contains melamine and / or a derivative thereof and formaldehyde.
The thermosetting urea resin contains urea and / or a derivative thereof and formaldehyde.

  Reinforcing fibers are fibers that are contained or dispersed in polymers in the field of polymer-containing composite materials in order to improve the toughness of resin members, for example, carbon fibers, glass fibers, or mixed fibers thereof. Can be mentioned. From the viewpoint of further improving the bonding strength, the reinforcing fiber is preferably a carbon fiber.

  Reinforcing fibers are generally roughly classified into continuous fibers and discontinuous fibers. In the present invention, the reinforcing fiber may be a discontinuous fiber or a continuous fiber.

  When the reinforcing fiber is a discontinuous fiber, the reinforcing fiber is contained in the resin member 12 in a randomly oriented form, and the average fiber length is usually 50 mm or less, particularly 1 mm to 50 mm, preferably 1 mm to 30 mm. The average fiber diameter of the reinforcing fibers is not particularly limited, and is, for example, 2 to 20 μm, preferably 6 to 15 μm.

  When the reinforcing fiber is a continuous fiber, the reinforcing fiber is contained in the resin member 12 in a regularly oriented form, and the average fiber length is not particularly limited. The average fiber diameter may be in the same range as the average fiber diameter of the discontinuous fibers. The regular orientation form may be, for example, a fabric orientation form.

  The content of the reinforcing fiber is not particularly limited as long as the fiber exposure rate described later is achieved, and is usually about 30 to 70% by volume with respect to the total amount of the resin member.

  The content of the reinforcing fibers can be measured as a ratio of the total area occupied by the reinforcing fibers to the total area of the resin member 12 in a parallel section with respect to the thickness direction of the resin member 12. In the present invention, the content of reinforcing fibers uses an average value of measured values in any five parallel cross sections of the resin member 12.

  The resin member 12 has a reinforcement fiber exposure rate of 2% or more on the bonding surface with the other member 11, and is preferably 5% or more, more preferably 10% or more, and still more preferably from the viewpoint of further improving the bonding strength. It is 20% or more, particularly preferably 30% or more, and most preferably 55% or more. The exposure rate of the reinforcing fibers is preferably as large as possible from the viewpoint of bonding strength, and the upper limit value is not particularly limited, and may be 100%. The exposure rate of the reinforcing fiber is usually 95% or less, preferably 90% or less, more preferably 80%, from the viewpoint of the balance between the workability of the fiber exposure process described later and the further improvement of the bonding strength. Hereinafter, it is more preferably 70% or less, particularly preferably 60% or less.

  In the present invention, the resin member 12 contains a reinforcing fiber that is generally contained for the purpose of improving toughness and the like, and achieves the above-described exposure rate, whereby the resin member 12 is a thermosetting resin member. Even so, the bonding strength with other members (for example, metal members) 11 can be improved more sufficiently. Although the details of the mechanism are not clear, it is thought to be based on the following theory. In the joining system between the thermosetting resin member and another member via the thermoplastic resin, the thermoplastic resin softened between the reinforcing fibers exposed on the surface of the resin member 12 due to the softening (and melting) of the thermoplastic resin 50. As a result, the exposed reinforcing fibers are embedded in the thermoplastic resin and solidification occurs. Thereby, the anchor effect by exposure of a reinforced fiber is exhibited, and it contributes more fully to the raise of joint strength. When the exposure rate of the reinforcing fibers is less than 2%, the anchor effect due to the exposure of the reinforcing fibers is not sufficiently exhibited, and the bonding strength is not sufficiently increased.

  In the present invention, the bonding surface of the resin member 12 with the other member 11 that should have a predetermined fiber exposure rate is the entire surface of the bonding side surface 121 with the other member 11 of the resin member 12 as shown in FIG. However, from the viewpoint of ease of fiber exposure processing described later, at least a region including the region P ′, preferably a region including at least the region Q may be used. The bonding surface of the resin member 12 with the other member 11 that should have a predetermined fiber exposure rate is preferably a region P ′ from the viewpoint of the balance between the ease of fiber exposure processing described later and the further improvement of the bonding strength. The region Q is more preferable. The region R is a region on the surface of the resin member 12 that comes into contact with the other member 11 when the other member 11 and the resin member 12 are overlapped. The region P ′ is a region inside the broken line in FIG. 4, and when the other member 11 and the resin member 12 are overlapped, the pressing region P of the rotary tool 16 on the other member 11 (see FIG. 1). ) Is a region on the surface of the resin member 12 corresponding directly below. The region Q is a region inside the broken line in FIG. 4, and is a substantially circular region having a diameter of 1.1 × D1 to 5 × D1 when the diameter of the rotary tool 16 is D1 (mm). is there. The diameter of the region Q is preferably 1.2 × D1 to 4 × D1, more preferably from the viewpoint of the balance between the ease of fiber exposure processing to be described later for exposing the reinforcing fibers and the further improvement of the bonding strength. 1.3 × D1 to 3 × D1, more preferably 1.4 × D1 to 3 × D1, and most preferably 1.5 × D1 to 2.5 × D1. In the present invention, the region P ′ and the region Q may have a concentric shape.

  The exposure rate of the reinforcing fiber can be measured by visually discriminating a portion (region) where the reinforcing fiber is exposed from a photograph of the surface of the resin member 12 or an image with a microscope or a microscope, and calculating the area ratio by image processing. . For example, in the photograph of the surface of the resin member 12 shown in FIG. 5, the portion where the reinforcing fiber is exposed (fiber exposure processing region) is visually determined as a broken line region, the broken line region is image-processed, and the reinforcing fiber occupies the broken line region The exposure rate can be obtained as a ratio of the total area to the total area of the broken line region. The broken line area in FIG. 5 may correspond to, for example, the area Q in FIG. When there are a plurality of exposed fiber regions, it is only necessary that the exposure rate is achieved in each exposed fiber treatment region. When discriminating the fiber-exposed region, the untreated region usually has a reinforcing fiber exposure rate of 1% or less, as will be described later, and there is a clear difference in brightness between the untreated region and the fiber-exposed region. Since this occurs, the determination can be easily performed. FIG. 5 is an example of a photograph of a plurality of regions exposed to fibers on the surface of the thermosetting resin member used in the bonding method of the present invention.

  The surface roughness Ra of the bonding surface of the resin member 12 with the other member 11 is not particularly limited as long as the fiber exposure rate is achieved on the bonding surface, and is usually 1 to 100 μm, particularly 2 to 50 μm. There may be. In the present invention, the bonding surface of the resin member 12 with the other member 11 having the above surface roughness is the same region as the bonding surface of the resin member 12 with the other member 11 that should have a predetermined fiber exposure rate. May be.

  As the surface roughness Ra, an average value of values measured by a laser microscope (manufactured by Keyence Corporation) at an arbitrary 10 points is used. The surface roughness Ra is a surface roughness based on the unevenness of the surface of the resin itself in the resin member 12, and is a value that does not depend on the presence of exposed reinforcing fibers.

  The resin member 12 has a substantially flat plate shape as a whole in FIG. 1 and the like, but is not limited to this, and when the resin member 12 is overlapped with another member 11 for joining, the other member As long as the part immediately below 11 has a substantially flat plate shape, it may have any shape. The part immediately below the other member 11 in the resin member 12 is generally composed of a flat surface on both sides.

  The thickness t (thickness before joining treatment; see FIG. 3) of the portion immediately below the other member 11 in the resin member 12 is usually 2 to 10 mm, particularly 2 to 5 mm, but is not limited thereto.

  The resin member 12 may further contain additives other than reinforcing fibers, such as stabilizers, flame retardants, colorants, foaming agents, and the like.

  The resin member 12 can be produced by molding and curing a resin member composition containing a thermosetting resin, reinforcing fibers, and a desired additive (for example, a curing agent), and then performing fiber exposure treatment. When the fiber exposure treatment is not performed, even if the content of the reinforcing fiber is 80% by volume, the fiber exposure rate on the surface is usually 1% or less (particularly less than 1%), and therefore used in the present invention. In obtaining a thermosetting resin member, the fiber exposure process is an essential process.

  The molding method is not particularly limited, and examples thereof include an autoclave method, a hand layup method, an RTM method (Resin Transfer Molding), a filament winding method, an injection molding method, and a press molding method. As the curing method, a heat curing method and / or a light irradiation method may be employed depending on the characteristics of the resin.

  The fiber exposure treatment is a treatment for exposing the reinforcing fibers by scraping or peeling the resin on the surface of the resin member. By the fiber exposure treatment, the above-described exposure rate of the reinforcing fibers is achieved. The fiber exposure treatment is not particularly limited as long as the exposure of the reinforcing fibers is achieved, and examples thereof include a shot blast treatment, a laser irradiation treatment, and a polishing treatment. From the viewpoint of exposure efficiency, it is preferable to perform shot blasting.

  The shot blasting process is a process of spraying particles on the surface of the resin member to scrape or peel off the resin on the surface. The fiber exposure rate can be controlled by adjusting the particle type, particle size, spraying speed, and the like. Examples of the shot blasting include sand shot blasting, dry ice shot blasting, and soft shot blasting (dry ice cleaning).

  The sand shot blasting process is a process in which hard particles such as ceramic and metal are sprayed on the surface of the resin member to scrape or peel off the resin on the surface. The fiber exposure rate can be controlled by adjusting the type and particle size of the hard particles, the spraying speed, and the like.

  The dry ice shot blasting process is a process of spraying dry ice particles on the surface of the resin member to scrape or peel off the resin on the surface. The fiber exposure rate can be controlled by adjusting the particle size of the dry ice particles, the spraying speed, and the like.

  The soft shot blasting process (dry ice cleaning) is a process in which dry ice is finely divided into a powder of about 0.3 mm and sprayed onto the surface of the resin member to scrape or peel off the resin on the surface. The fiber exposure rate can be controlled by adjusting the projection time, spraying speed, and the like.

  The laser irradiation process is a process of irradiating the surface of the resin member with a beam to scrape or peel off the resin on the surface. The fiber exposure rate can be controlled by adjusting the beam type, irradiation range (particle size), and output. In the laser irradiation treatment, penetration of the resin member by the beam is likely to occur, but the resin on the surface of the resin member can be scraped or peeled by setting a wide irradiation range, reducing output, or the like.

  The polishing process is a process of polishing or peeling off the resin on the surface by polishing the surface of the resin member using an abrasive. The fiber exposure rate can be controlled by adjusting the type and particle size of the abrasive and the pressing force.

(4) Other members The other members 11 may be metal members or resin members. When the other member 11 is a resin member, the resin member may be a thermoplastic resin member or a thermosetting resin member. Here, the thermoplastic resin member includes a thermoplastic resin selected from the same range as the above-described thermoplastic resin interposed between the thermosetting resin member 12 and the other member 11. The thermosetting resin member as the other member 11 may be selected from the same range as the thermosetting resin member 12 described above. From the viewpoint of generating frictional heat in the friction stir welding method, the other member 11 is preferably a metal member.

When the other member 11 is a metal member, any metal having a melting point higher than that of the thermoplastic polymer constituting the thermoplastic resin 50 can be used as the metal constituting the metal member. Among these, the following metals and alloys used in the automotive field are preferably used:
Aluminum and aluminum alloys (5000 series, 6000 series);
steel;
Magnesium and its alloys;
Titanium and its alloys.

  The other member 11 used in the present invention has a substantially flat plate shape as a whole in FIG. 1 or the like, but is not limited to this, and at least a portion overlapping with the resin member 12 is a substantially flat plate. As long as it has a shape, it may have any shape. The part of the other member 11 that is overlapped with the resin member 12 is generally formed of a flat surface on both sides.

  The thickness T (thickness before joining treatment; see FIG. 3) of the substantially flat plate-shaped portion that is superimposed on the resin member 12 in the other member 11 is usually 0.5 to 4 mm, but is not limited thereto.

(5) Joining method The joining method of the thermosetting resin member by the friction stir welding method according to the present invention can be applied to any other member 11 described above, but is based on the efficient generation of frictional heat. From the viewpoint of further improving the bonding strength, it is preferable to apply to a metal member. Hereinafter, the joining method of the thermosetting resin member and the metal member by the friction stir welding method according to the present invention will be described in detail. However, even when a member other than the metal member is used as the other member 11, it is clear that the effect of improving the bonding strength based on the anchor effect of the exposed reinforcing fiber can be obtained as in the case of using the metal member. is there.

The method for joining thermosetting resin members by the friction stir welding method according to the present invention includes at least the following steps:
A first step of superimposing the thermosetting resin member 12 and the metal member 11 via the thermoplastic resin 50; and while rotating the rotary tool 16, the metal member 11 is pressed against the metal member 11 to generate frictional heat. After the softening and melting of the thermoplastic resin 50 by the second step, the second step of solidifying and joining the thermosetting resin member 12 and the metal member 11:
Is included.

  In the first step, as shown in FIG. 1, the thermosetting resin member 12 and the metal member 11 are superposed through a thermoplastic resin 50 (not shown in FIG. 1) at a desired joining site.

  In the second step, as shown in FIG. 6, at least a pushing stirring step C2 is performed in which the rotary tool 16 is pushed into the metal member 11 to enter a depth not reaching the boundary surface 13 between the metal member 11 and the thermoplastic resin 50. Preferably it is done.

In the second step, it is preferable to perform a preheating step C1 in which the rotary tool 16 is rotated in a state where only the front end portion of the rotary tool 16 is in contact with the surface portion of the metal member 11 before the pushing and stirring step C2. It does not necessarily have to be done.
After the indentation stirring step C2, it is preferable to perform the stirring maintenance step C3 in which the rotation operation of the rotary tool 16 is continued at a position where the rotary tool 16 has been advanced to a depth that does not reach the boundary surface. It doesn't have to be.

  Each step in the present invention may be performed by controlling the pressing force (pressing force) and pressing time of the rotating tool, and the amount of movement of the rotating tool in the pressing direction (joining member after contacting the joining member) And the movement time thereof may be controlled.

  Hereinafter, these steps will be described in detail.

(Preheating process C1)
In the preheating step C1, by bringing the rotary tool 16 and the receiving member 17 close to each other, as shown in FIG. 3, only the tip of the rotary tool 16 is placed on the surface portion (upper surface portion in the illustrated example) of the metal member 11. This is a step of rotating the rotary tool 16 in a contacted state. In the preheating step C1, the rotary tool 16 is rotated at a predetermined rotation speed (for example, 3000 rpm) for a first pressurizing time (for example, 1.00 seconds) with a first pressure (for example, 900 N). Specifically, the state in which only the tip portion of the rotary tool 16 is in contact with the surface portion of the metal member 11 means that only the pin portion 16a and the shoulder portion 16b at the tip portion of the rotary tool 16 are in contact with the surface portion of the metal member 11. It is a state.

  Specifically, in the preheating step C <b> 1, frictional heat is generated at the surface portion (upper surface portion in the illustrated example) of the metal member 11 by pressing of the rotary tool 16. The frictional heat is transmitted to the inside of the metal member 11, and the range of the pressing area P (the pressing area by the rotary tool 16) of the metal member 11 and the area near the pressing area P are preheated. Thereby, it becomes easy to push the rotary tool 16 into the metal member 11 in the next pushing and stirring step C2.

  The first pressurizing force and the first pressurizing time in the preheating step C1 are from the viewpoint of productivity in addition to the ease of pressing the rotary tool 16 and the ease of softening and melting of the thermoplastic resin 50 as described above. The value varies depending on, for example, the rotational speed of the rotary tool 16, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the first pressing force in the preheating step C1 is preferably a value of 700 N or more and less than 1200 N. The first pressurizing time is preferably 0.5 seconds or more and less than 2.0 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Indentation stirring step C2)
In the pushing and stirring step C2, the rotating tool 16 and the receiving member 17 are brought close to each other, thereby pushing the rotating tool 16 into the metal member 11 as shown in FIG. When the pushing and stirring step C2 is performed after the preheating step C1, the rotating tool 16 and the receiving member 17 are brought closer to each other, thereby pushing the rotating tool 16 into the metal member 11 as shown in FIG. Thereby, the rotary tool 16 is advanced to a depth not reaching the boundary surface 13 between the metal member 11 and the thermoplastic resin 50. At this time, the portion immediately below the rotary tool of the metal member 11 may be protruded and deformed toward the thermoplastic resin 50 (not shown).

  Specifically, in the indentation stirring step C2, the rotary tool 16 is moved at a second pressurizing time (for example, 1500 N) that is larger than the first pressurizing time and shorter than the first pressurizing time (for example, Rotate at a predetermined rotation speed (for example, 3000 rpm) for 0.25 seconds.

  In the indentation stirring step C2, the rotating tool 16 is pushed into the metal member 11 when the applied pressure is larger than that in the preheating step C1. That is, the rotary tool 16 enters deep inside the metal member 11. Preferably, the pressing of the rotary tool 16 moves the boundary surface 13 between the metal member 11 and the thermoplastic resin 50 toward the support 17 side (lower side in FIG. 6) immediately below the rotary tool of the metal member 11. The directly lower portion projects and deforms toward the resin member 12 in the thermoplastic resin 50. Thereby, the thermoplastic resin 50 is softened and melted by frictional heat, and the molten resin flows on the metal member side surface 121 of the resin member 12 in the direction from the region 112 directly below to the outer peripheral region. The molten resin spreads in a substantially circular shape centering on the region directly under the rotary tool. As a result, after solidification by cooling, the interaction is performed in a wider region between the metal member 11 and the thermoplastic resin 50 and between the thermoplastic resin 50 and the resin member 12, thereby achieving bonding. .

  If the rotary tool 16 is further pushed in (that is, if the applied pressure is too high and / or the pressurizing time is too long), the shoulder portion 16b of the rotary tool 16 exceeds the boundary surface 13. That is, the rotary tool 16 penetrates the metal member 11, and the outer peripheral portion of the rotary tool 16 contacts the thermoplastic resin 50 and the resin member 12. Then, the metal member 11 is in a holed state in which the hole through which the rotary tool 16 has passed is opened, resulting in poor bonding.

  Therefore, in this indentation stirring step C2, the indentation of the rotation tool 16 is stopped when the shoulder portion 16b of the rotation tool 16 enters a depth that does not reach the boundary surface 13. In other words, the rotary tool 16 is advanced to a depth that does not reach the boundary surface 13. As a result, in the next agitation maintaining step C3, frictional heat is generated at a reference position close to the resin member 12, and a large amount of frictional heat is transmitted to the resin member 12 to promote softening and melting of the thermoplastic resin 50.

  The second pressing force and the second pressurizing time in the indentation stirring step C2 are set from the viewpoint of avoiding the opening of the metal member 11 as described above and the rotating tool 16 as close to the resin member 12 as possible. The value varies depending on, for example, the number of rotations of the rotary tool 16, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the second applied pressure in the indentation stirring step C2 is preferably a value of 1200 N or more and less than 1800 N. The second pressurization time is preferably 0.1 seconds or more and less than 0.5 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Stirring maintenance step C3)
The agitation maintaining step C3 stops the mutual approach between the rotary tool 16 and the receiving member 17 and, as shown in FIG. 6, the position where it has entered to a depth that does not reach the boundary surface 13 (this is referred to as “reference position”). The rotation tool 16 continues to rotate. In the stirring maintaining step C3, the rotary tool 16 is moved to a third pressurizing time (for example, 5.75) longer than the first pressurizing time with a third pressurizing force (for example, 500 N) smaller than the first pressurizing force. Seconds) at a predetermined rotation speed (for example, 3000 rpm).

  In the stirring maintaining step C3, the rotating tool 16 is substantially maintained at the reference position by the applied pressure being smaller than that of the preheating step C1 (of course, being smaller than the pushing stirring step C2). Since the rotation operation of the rotary tool 16 is continued at the reference position close to the thermoplastic resin 50, a large amount of frictional heat is generated, and most of the generated frictional heat is transferred to the thermoplastic resin 50. Therefore, the thermoplastic resin 50 is sufficiently softened and melted in a wide range beyond the range of the region immediately below the pressing region P.

  The third pressurizing force and the third pressurizing time in the stirring maintaining step C3 are set from the viewpoint of sufficient softening / melting and productivity in a wide range of the thermoplastic resin 50 as described above, and the values thereof are: For example, it changes depending on the number of rotations of the rotary tool 16, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the third pressing force in the stirring and maintaining step C3 is preferably a value of 100 N or more and less than 700 N. The third pressurizing time is preferably a value of 1.0 second or more and less than 20 seconds, particularly a value of 3.0 seconds or more and 10 seconds or less. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Holding process C4)
After the agitation maintenance step C3, the rotation of the rotary tool 16 may be stopped, and a holding step C4 for holding the rotary tool 16 with a predetermined pressurizing force for a predetermined pressurization time may be performed. It is not necessary.
Similarly, as shown in FIG. 6, the holding step C <b> 4 is a step in which the rotation of the rotary tool 16 is stopped and the rotary tool 16 is held for a predetermined time with a predetermined pressure in that state. In the holding step C4, the rotary tool 16 is moved at a fourth pressure force (for example, 1000 N) that is larger than the third pressure force but smaller than the second pressure force and shorter than the third pressurization time but the second pressure force. Hold for a fourth pressurization time (for example, 5.00 seconds) longer than the pressure time.

  In the holding step C4, the rotation of the rotary tool 16 is stopped, whereby the generation of frictional heat is completed. That is, the substantial operation as the friction stir welding is finished, and cooling of the workpiece 10 is started. During the cooling period of the workpiece 10, the rotating tool 16 that has stopped rotating receives the thermosetting resin member 12 and the metal member 11 because the applied pressure is smaller than the indentation stirring step C 2 but larger than the stirring maintaining step C 3. Clamp it with the tool 17. Thereby, the adhesive force during cooling between the thermosetting resin member 12 and the metal member 11 is enhanced, and the bonding strength after completion of cooling and solidification is enhanced.

  The fourth pressurizing force and the fourth pressurizing time in the holding step C4 are set from the viewpoint of improving the adhesion strength of the region immediately below the pressing region P during the cooling period as described above, and the values thereof are, for example, the metal member 11 It depends on the type of material. For example, when the aluminum alloy metal member 11 is used, the fourth pressing force in the holding step C4 is preferably a value of 700 N or more and less than 1200 N, for example. The fourth pressurization time is preferably, for example, a value of 1 second or longer.

In the said joining method, when melting | fusing point of the thermoplastic resin 50 is set to Tm (degreeC), joining temperature is Tm-50-Tm + 150 degreeC normally. From the viewpoint of further improving the bonding strength, the bonding temperature is preferably in the following range depending on the type of the thermoplastic resin 50.
When the acid-modified polyolefin or polyamide is used, the joining temperature is preferably Tm to Tm + 150 ° C, more preferably Tm + 20 to Tm + 130 ° C, and further preferably Tm + 70 to Tm + 120 ° C.
In the case of a thermoplastic epoxy polymer, the joining temperature is preferably Tm-50 to Tm + 30 ° C, more preferably Tm-10 to Tm + 20 ° C.
In the case of polyamide, the joining temperature is preferably Tm + 10 to Tm + 70 ° C., more preferably Tm + 20 to Tm + 60 ° C.
In the case of a vinyl acetate-containing polymer, the joining temperature is preferably Tm to Tm + 80 ° C.
The joining temperature is the maximum temperature of the region 112 immediately below the interface between the thermoplastic resin 50 and the resin member 12, and is the pressing force (pressing force), pressing time and number of rotation of the rotary tool 16, or the pressing direction of the rotating tool. It can be controlled by adjusting the moving amount, the moving time and the rotational speed.

  Although the said joining method demonstrated the case where a metal member and a resin member are joined to a point shape, without moving a rotation tool on the contact surface of a metal member in a surface direction (point joining), in the said surface direction It is clear that the effect of the present invention can be obtained even when the metal member and the resin member are joined linearly while moving the rotary tool (line joining).

(6) Bonded Body In the bonded body of the thermosetting resin member 12 and the other member 11 obtained by the method of the present invention, the thermoplastic resin 50 is interposed between the thermosetting resin member 12 and the other member 11. is doing.

  Also in such a joined body, the thermosetting resin member 12 has the exposure rate of the reinforcing fiber on the joining surface with the other member 11 within the above-described range. That is, the exposure rate of the reinforcing fiber does not change before and after the implementation of the thermosetting resin member joining method of the present invention. For example, the exposure rate A of the reinforcing fiber of the thermosetting resin member 12 before the bonding method of the present invention is not changed by bonding with another resin, and the thermosetting resin member in the bonded body obtained after the execution. The exposure rate B of the 12 reinforcing fibers shows a value substantially equal to the exposure rate A before the implementation.

  The exposure rate B of the reinforcing fiber of the thermosetting resin member 12 in the joined body is determined by the above-described measurement by peeling the thermosetting resin member 12 from the other member 11 and removing the thermoplastic resin 50 by dissolution in a solvent or the like. It can be measured by providing. However, in a joining method in which the temperature partially (or locally) rises above the resin decomposition temperature, such as a friction stir welding method, the thermosetting resin may be decomposed and the exposure rate may change. The decomposition of the thermosetting resin usually takes place in the region P ′ in FIG. 4, and the position of the decomposition portion can be clearly discriminated by the difference in brightness from the surrounding area. Therefore, the exposure rate B is measured, for example, in a region within the region Q (fiber exposure processing region) in FIG. 4 and outside the region P ′. In other words, in the thermosetting resin member obtained by peeling from the joined body or the like, the exposure rate B measured in a region within the region Q and outside the region P ′ is defined by the present invention. If it is in the range of a rate range, it can be discriminate | determined clearly that the thermosetting resin member of this invention is used.

  In the joined body, the thermoplastic resin 50 usually has a thickness (a thickness after joining) of 1 to 500 μm, preferably 10 to 400 μm.

[Example 1]
(Metal member)
As the metal member, a flat plate member made of a 6000 series aluminum alloy was used (length 100 mm × width 30 mm × thickness 1.2 mm).

(Thermosetting resin member)
A thermosetting epoxy resin composition was prepared by mixing bisphenol A type epoxy resin (EP-834, manufactured by Japan Epoxy Resin Co., Ltd.), carbon fiber and o-phenylenediamine as a curing agent. This thermosetting epoxy resin composition was molded and sufficiently cured by being held in a mold at 230 ° C. to produce a resin member 12 (length 100 mm × width 50 mm × thickness 3 mm). The carbon fiber content was 50% by volume, the average fiber length of the carbon fibers was 3 mm, and the average fiber diameter was 7 μm.

  The bonding surface in the resin member 12 was subjected to fiber exposure treatment. Specifically, as shown in FIG. 4, the sand shot blasting process was performed on the region Q in the resin member 12. In the sand shot blasting process, ceramic particles (particle size: 500 to 600 μm) were used. In FIG. 4, the region P ′ is on the surface of the resin member 12 corresponding to the region immediately below the pressing region P (see FIG. 1) of the rotary tool 16 on the metal member 11 when the metal member 11 and the resin member 12 are overlapped. It is an area. The region Q is a region where the fiber exposure process has been performed, and is a region including the region P ′. In this embodiment, the region P ′ and the region Q are concentric with each other, and the diameter of the region Q is 2 × D1 when the diameter of the rotary tool 16 is D1 (mm). ing. The exposure rate of the reinforcing fibers in the region Q was 30%, and the surface roughness Ra was 3.4 μm.

(Thermoplastic resin sheet)
A polymer sheet of polyamide 12 (Toray Plastic Seiko Co., Ltd., thickness: 500 μm) was used. The polyamide had a melting point of 220 ° C.
The thermoplastic resin sheet was a circular sheet having a diameter of 12 mm, and was used so that the center thereof was disposed on the axis of the rotary tool.

(Rotation tool)
As the rotation tool, the rotation tool 16 shown in FIG. 2 was used. The dimensions of each part were D1 = 10 mm, D2 = 2 mm, h = 0.5 mmmm, and the rotary tool was made of tool steel.

(Joining method)
The joined body of the thermosetting resin member 12 and the metal member 11 was manufactured by the following method.
First step:
The thermosetting resin member 12 and the metal member 11 were superposed as shown in FIG. 1 with a thermoplastic resin sheet 50 interposed therebetween.

Second step:
As shown in FIG. 3, the rotary tool 16 was rotated in a state where only the tip of the rotary tool 16 was in contact with the surface portion of the metal member 11 (preheating step C1: pressure 900N, pressurization time 1.00 seconds). Tool rotation speed 3000 rpm).
Next, as shown in FIG. 6, the rotary tool 16 was pushed into the metal member 11 to a depth not reaching the boundary surface between the metal member 11 and the thermoplastic resin 50 (indentation stirring step C2: applied pressure 1500 N, applied pressure Pressure time 0.25 seconds, tool rotation speed 3000 rpm).
Next, as shown in FIG. 6, the rotation operation of the rotary tool 16 was continued at a position where the rotary tool 16 was advanced to a depth that did not reach the boundary surface (stirring maintenance step C3: pressurizing pressure 500 N, pressurization time 5). 75 seconds, tool rotation speed 3000 rpm).
Subsequently, the rotary tool 16 was extracted from the joined body 20 and allowed to cool.

[Examples 2 to 11]
A joined body was obtained by the same method as in Example 1 except that a resin member having various fiber exposure rates achieved by various fiber exposure treatments was used.
Table 1 shows the types of fiber exposure treatment and the achieved exposure rate and surface roughness Ra in each example.

In the table, the level in each processing means that processing conditions such as processing time are different from each other.
Table 2 shows the projectiles in each process.

[Joint strength]
As shown in FIG. 7, the joined body of the thermosetting resin member 12 and the metal member 11 was placed in the jig 100. The jig 100 is configured such that a downward force acts on the upper end portion of the resin member 12 by pulling the jig 100 downward. By fixing the jig 100 and pulling the metal member 11 upward, a downward force acts on the upper end portion of the resin member 12, and the joint strength of the joint portion is not affected by the strength of the base material of the resin member 12. (Tensile shear strength S) was measured. FIG. 8 and FIG. 9 show the relationship between the fiber exposure rate and the bonding strength. The relationship between the surface roughness Ra and the bonding strength is shown in FIG. 8 and 9, the exposure rate “1.00” means an exposure rate of 100%.

A: 8.3 kN ≦ S (best);
A: 7.5 kN ≦ S <8.3 kN (excellent);
○: 6.0 kN ≦ S <7.5 kN (good);
Δ: 3.0 kN ≦ S <6.0 kN (no problem in practical use);
X: S <3.0 kN (practical problem).

From FIG. 10, no clear relationship was found between the surface roughness and the bonding strength, but from FIG. 8, it was suggested that the exposed fibers sufficiently contributed to the bonding.
From FIG. 9, a correlation was recognized between the fiber exposure rate and the bonding strength.
From FIG. 8 to FIG. 10, the following is clear: In the joining system between the thermosetting resin member and another member via the thermoplastic resin, the anchor effect due to the unevenness of the surface of the resin itself in the resin member 12 Rather, the anchor effect due to the exposure of the reinforcing fibers contained in the resin member 12 contributes significantly to the increase in bonding strength.

[Measuring method]
The exposure rate and surface roughness Ra of the reinforcing fibers were measured by the methods described above.

  The joining method according to the present invention is useful for joining a thermosetting resin member and other members (particularly metal members) in the fields of automobiles, railway vehicles, aircraft, home appliances, and the like.

1: Friction stir welding apparatus 10: Work 11: Metal member 12: Thermosetting resin member 13: Interface between metal member and thermoplastic resin 16: Rotating tool 17: Receiving tool 50: Thermoplastic resin (layer)
100: Jig for measuring joint strength 111: Resin member side surface of metal member P: Pressing region (scheduled pressing region)
121: Metal member side surface of thermosetting resin member

Claims (31)

The thermosetting resin member including the reinforcing fiber and another member are overlapped with each other through the thermoplastic resin, and heat and pressure are applied to soften the thermoplastic resin and the thermosetting resin member and the other member. A thermosetting resin member joining method by a hot-pressure joining method for joining members,
A thermosetting resin member joining method using, as the thermosetting resin member, a thermosetting resin member having an exposure rate of the reinforcing fibers of 2% or more on a joining surface with the other member.   The joining of the thermosetting resin member according to claim 1, wherein an anchor effect based on embedding of the exposed reinforcing fiber of the thermosetting resin member in the softened thermoplastic resin contributes to the joining of the thermosetting resin member. Method.   The method for joining thermosetting resin members according to claim 1 or 2, wherein the reinforcing fibers are one or more fibers selected from the group consisting of carbon fibers and glass fibers.   The method for joining thermosetting resin members according to claim 1, wherein the reinforcing fibers have an average fiber length of 1 to 50 mm and an average fiber diameter of 2 to 20 μm.   The said thermosetting resin member is a joining method of the thermosetting resin member in any one of Claims 1-4 which contains the said reinforced fiber by content of 30-70 volume%.   The joining method of the thermosetting resin member in any one of Claims 1-5 which achieves the exposure rate of the said reinforced fiber by a shot blast process, a laser irradiation process, or a grinding | polishing process.   The said other member is a joining method of the thermosetting resin member in any one of Claims 1-6 which is a metal member.   The method for joining thermosetting resin members according to claim 1, wherein the thermoplastic resin is interposed at a thickness of 10 to 600 μm before joining.   The thermoplastic resin is one or more selected from the group consisting of a sheet form, a film form formed on the surface of the thermosetting resin member, and a film form formed on the surface of the other member. The joining method of the thermosetting resin member in any one of Claims 1-8 which has a form. The thermoplastic resin is a thermoplastic polymer having a functional group;
The thermosetting resin member according to claim 1, wherein the functional group is a group containing one or more atoms selected from the group consisting of an oxygen atom, a nitrogen atom, a fluorine atom, and a sulfur atom. Joining method.   The functional group is one or more groups selected from the group consisting of carboxyl group, hydroxyl group, amide bond group, ester bond group, ether group, thioether group, carboxylate group, fluorine atom, urethane bond group and carbonate group. The joining method of the thermosetting resin member of Claim 10 which is.   The thermoplastic resin is a group consisting of acid-modified polyolefin, thermoplastic epoxy polymer, polyamide, vinyl acetate-containing polymer, polyester, alkyl poly (meth) acrylate, polycarbonate, polyurethane, polyether, liquid crystal polymer, fluorine-containing polymer and polyolefin. The method for joining thermosetting resin members according to claim 1, wherein the thermosetting resin member is at least one polymer selected from the group consisting of:   The said thermosetting resin member is comprised from 1 or more types of resin selected from the group which consists of a thermosetting epoxy resin, a thermosetting phenol resin, a thermosetting melamine resin, and a thermosetting urea resin. The joining method of the thermosetting resin member in any one of -12. The other member is a metal member;
The thermosetting resin member and the metal member are overlapped with each other through the thermoplastic resin, and while rotating a rotary tool, the metal member is pressed against the metal member to generate frictional heat, and the thermoplastic resin is generated by the frictional heat. The method for joining thermosetting resin members according to any one of claims 1 to 13, which is based on a friction stir welding method for softening and joining. The method for joining thermosetting resin members according to claim 14, wherein the friction stir welding method includes the following steps:
A first step of superimposing the thermosetting resin member and the metal member through the thermoplastic resin; and while rotating the rotary tool, the metal member is pressed against the metal member to generate frictional heat. A second step of softening and melting the thermoplastic resin and solidifying and joining the thermosetting resin member and the metal member.   The heat according to claim 15, wherein the second step includes a pressing and stirring step of pressing the rotating tool into the metal member to enter a depth that does not reach a boundary surface between the metal member and the thermoplastic resin. A method of joining cured resin members.   The second step further includes a preheating step of rotating the rotary tool in a state in which only a tip portion of the rotary tool is in contact with a surface portion of the metal member before the pushing and stirring step. The method for joining thermosetting resin members according to 16. In the preheating step, the rotary tool is rotated by a first pressurizing time while being pressed with a first pressing force,
18. In the indentation stirring step, the rotary tool is rotated by a second pressurization time shorter than the first pressurization time while pressing the rotary tool with a second pressurization force larger than the first pressurization force. Joining method of thermosetting resin member. The second step further comprises an agitation maintaining step of continuing the rotation operation of the rotary tool at a position where the rotary tool has entered to a depth that does not reach the boundary surface,
19. In the stirring maintaining step, the rotary tool is rotated by a third pressurizing time longer than the first pressurizing time while pressing the rotary tool with a third pressurizing force smaller than the first pressurizing force. Joining method of thermosetting resin member.   The thermosetting resin member used in the joining method of the thermosetting resin member in any one of Claims 1-19. A joined body of a thermosetting resin member containing reinforcing fibers and another member,
A thermoplastic resin is interposed between the thermosetting resin member and the other member,
The said thermosetting resin member is a joined body which is a thermosetting resin member whose exposure rate of the said reinforced fiber in a joining surface with said other member is 2% or more.   The anchor effect based on the embedding of the exposed reinforcing fiber of the thermosetting resin member in the thermoplastic resin contributes to the joining of the thermosetting resin member and the other member. Joined body.   The joined body according to claim 21 or 22, wherein the reinforcing fibers are one or more fibers selected from the group consisting of carbon fibers and glass fibers.   The joined body according to any one of claims 21 to 23, wherein the reinforcing fibers have an average fiber length of 1 to 50 mm and an average fiber diameter of 2 to 20 µm.   The joined body according to any one of claims 21 to 24, wherein the thermosetting resin member contains the reinforcing fiber in a content of 30 to 70% by volume.   The joined body according to any one of claims 21 to 25, wherein the other member is a metal member.   The joined body according to any one of claims 21 to 26, wherein the thermoplastic resin is interposed at a thickness of 1 to 500 µm after joining. The thermoplastic resin is a thermoplastic polymer having a functional group;
The joined body according to any one of claims 21 to 27, wherein the functional group is a group containing one or more atoms selected from the group consisting of an oxygen atom, a nitrogen atom, a fluorine atom, and a sulfur atom.   The functional group is one or more groups selected from the group consisting of carboxyl group, hydroxyl group, amide bond group, ester bond group, ether group, thioether group, carboxylate group, fluorine atom, urethane bond group and carbonate group. The joined body according to claim 28, wherein   The thermoplastic resin is a group consisting of acid-modified polyolefin, thermoplastic epoxy polymer, polyamide, vinyl acetate-containing polymer, polyester, alkyl poly (meth) acrylate, polycarbonate, polyurethane, polyether, liquid crystal polymer, fluorine-containing polymer and polyolefin. The joined body according to any one of claims 21 to 29, which is one or more kinds of polymers selected from the group consisting of:   The said thermosetting resin member is comprised from 1 or more types of resin selected from the group which consists of a thermosetting epoxy resin, a thermosetting phenol resin, a thermosetting melamine resin, and a thermosetting urea resin. The joined body according to any one of?