JP4784362B2 - Tubular body - Google Patents

Description

  The present invention relates to a tubular body made of a metal / fiber reinforced resin composite material, and more particularly to a tubular body having improved adhesion between a metal layer and a fiber reinforced resin layer and suitable for use in golf club shafts, fishing rods, rackets and the like.

  A composite material in which metal and fiber reinforced resin are laminated and bonded together is a material that can exhibit both the excellent impact resistance, conductivity, etc. possessed by the metal, and the excellent lightness and high mechanical properties possessed by the fiber reinforced resin. Known as.

  Especially for golf club shafts, fiber reinforced resin shafts are superior in terms of weight reduction, but metal (for example, steel) shafts are still better because of their better feel at impact. Many steel shafts are used.

  Therefore, a golf club shaft made of a composite material of a metal and a fiber reinforced resin is expected as a golf club shaft that can achieve both improved feeling of hitting with a metal and light weight and high strength with a fiber reinforced resin.

  However, in a golf club shaft made of a metal / fiber reinforced resin composite material simply formed by bonding a metal layer and a fiber reinforced resin layer, delamination occurs between the metal layer and the fiber reinforced resin layer at the time of hitting. This causes a problem that the target characteristics cannot be expressed. In particular, when the metal layer is made of a titanium alloy, the metal layer is lightweight and excellent in mechanical properties. It is necessary to perform surface treatment such as chemical etching, resulting in poor productivity and high cost, and has not been put into practical use.

In order to improve the adhesion of the metal layer, surface treatments such as forming an anodized film have been proposed (for example, Patent Document 1 and Patent Document 2), but the adhesion between the metal and the adhesive is improved. However, the adhesiveness between the adhesive and the fiber reinforced resin is not necessarily improved. In addition, although a technique for increasing the toughness of the adhesive itself has been proposed (for example, Patent Document 3 and Patent Document 4), the adhesive layer and the fiber reinforced resin layer are suppressed although destruction in the adhesive layer is suppressed. The peel strength at the interface with the film is not necessarily improved.
JP 2002-129387A JP-A-7-252687 JP 58-189277 A JP 2004-263104 A

  Therefore, the object of the present invention is to improve the adhesion between the metal layer and the fiber reinforced resin layer, particularly when a tubular body such as a golf club shaft, a fishing rod, or a racket is composed of a metal / fiber reinforced resin composite material. An object of the present invention is to provide a tubular body that can solve problems such as peeling between both layers while exhibiting the excellent characteristics of each layer, and can be put to practical use.

  In order to solve the above problems, a tubular body according to the present invention is a tubular body composed of a metal / fiber reinforced resin composite material in which a metal layer and a fiber reinforced resin layer are bonded and integrated through an intermediate resin layer. The intermediate resin layer contains thermoplastic resin particles having an average particle diameter of 3 to 10 μm and an imidazole silane compound.

  In this tubular body, the boundary part (interface vicinity part) between the intermediate resin layer and the fiber reinforced resin layer is a mixed layer in which the thermoplastic resin constituting the particles and the reinforced fibers of the fiber reinforced resin layer are mixed. Is preferably formed.

  The thermoplastic resin particles are preferably present in the intermediate resin layer at least partially in the form of a continuous phase due to fusion of particles or the like.

  The matrix resin of the fiber reinforced resin layer and the base resin of the intermediate resin layer are preferably made of the same kind of resin (preferably, the same resin). For example, the matrix resin of the fiber reinforced resin layer and the base resin of the intermediate resin layer are preferably made of the same type or the same thermosetting resin (for example, epoxy resin).

  Although various metals can be adopted as the metal layer, the effect of the present invention is particularly great when the metal layer is composed of a layer containing titanium which is a difficult-to-adhere metal.

  In addition, various reinforcing fibers can be used as the reinforcing fiber of the fiber-reinforced resin layer, but particularly when the carbon fiber is included in the layer containing the reinforcing fiber, more excellent mechanical properties can be easily obtained as a whole tubular body, and , Its characteristics are also easy to control.

  By applying the tubular body according to the present invention to a golf club shaft in particular, it is possible to achieve both improved feeling of hitting with a metal, lighter weight and higher strength with a fiber reinforced resin, and the development of expected desirable characteristics. It becomes possible. However, the present invention can be applied to any tubular body in which both the characteristics possessed by the metal and the characteristics possessed by the fiber reinforced resin are desired. In addition to the golf shaft, the fishing rod, tennis racket, badminton racket, hockey It is also applicable to sticks, baseball or softball bats, pole vaulting poles, yacht masts, boat oars, and the like.

  In such a tubular body according to the present invention, the intermediate resin layer contains thermoplastic resin particles having a particle diameter in a predetermined range, whereby the thermoplastic resin particles ensure a predetermined thickness of the intermediate resin layer. An intermediate resin layer having a predetermined thickness is reliably interposed between the metal layer and the fiber reinforced resin layer. In addition, since the thermoplastic resin particles are blended in the intermediate resin layer, the toughness of the intermediate resin layer itself can be increased.

  The metal layer and the fiber reinforced resin layer are bonded and integrated through this intermediate resin layer. However, the intermediate resin layer contains an imidazole silane compound, so that the adhesion to the metal is improved, and it is difficult to adhere to the metal. Even for a certain titanium alloy or the like, good adhesiveness can be expressed, and the adhesiveness between the intermediate resin layer and the metal layer is greatly improved.

  Further, since the intermediate resin layer contains thermoplastic resin particles having a fine particle diameter in a predetermined range, in the vicinity of the interface with the fiber reinforced resin layer, there are more or less thermoplastic resin particles between the reinforced fibers of the fiber reinforced resin layer. It is possible to easily form a form that penetrates into the surface. That is, the boundary portion between the intermediate resin layer and the fiber reinforced resin layer can be formed in a mixed layer in which the thermoplastic resin particles and the reinforced fibers of the fiber reinforced resin layer are mixed. If the average particle diameter of the thermoplastic resin particles is significantly larger than 10 μm, the thermoplastic resin particles are difficult to enter between the reinforcing fibers, so that a mixed layer in which the thermoplastic resin particles and the reinforcing fibers of the fiber reinforced resin layer are mixed is formed. It is not preferable because it is difficult to do. In such a form, for example, if the intermediate resin layer and the fiber reinforced resin layer are simultaneously formed at a temperature equal to or higher than the melting point of the thermoplastic resin particles, the particles are easily at least partially in a continuous phase form by fusion or the like. It is a series. If such a form appears, the thermoplastic resin that is at least partially in the form of a continuous phase by fusion or the like is formed at the interface between the intermediate resin layer and the fiber reinforced resin layer. It exists across both layers, and the anchor effect will be exhibited from any layer. Due to this anchor effect, the adhesion between the intermediate resin layer and the fiber reinforced resin layer is also reliably and significantly improved. Further, when the outermost layer is a fiber reinforced resin layer, it is preferable that the outermost layer of the fiber reinforced resin layer is subjected to water repellent treatment to form a water repellent layer. When the tubular body of the present invention is exposed to high humidity or warm water, there is a concern that the adhesion between the metal and the fiber reinforced resin may deteriorate due to moisture absorption or water absorption of the fiber reinforced resin layer. This is because moisture absorption or water absorption can be suppressed and adhesion deterioration can be prevented.

  Thus, according to the tubular body according to the present invention, by bonding and integrating the metal layer and the fiber reinforced resin layer through the intermediate resin layer containing the thermoplastic resin particles of a predetermined particle size and the imidazole silane compound, A tubular body made of a metal / fiber reinforced resin composite material that can greatly improve adhesiveness and can exhibit excellent characteristics without causing delamination can be put into practical use.

  In particular, by applying the present invention to a golf club shaft, it is possible to achieve both improved feeling of hitting with a metal, lighter weight and higher strength with a fiber reinforced resin, and to exhibit desired desirable characteristics.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of a tubular body according to an embodiment of the present invention, and particularly shows an example of the case where the present invention is applied to a golf club shaft. In FIG. 1, reference numeral 1 denotes a cross section of a golf club shaft as a tubular body. This golf club shaft 1 is composed of a single layer or a plurality of layers (total of two layers in the illustrated example), a single layer or a plurality of layers (total of two layers in the illustrated example) fiber reinforced resin layer 3, a metal An intermediate resin layer 4 of a single layer or a plurality of layers (two layers in the illustrated example) is interposed between the layer 2 and the fiber reinforced resin layer 3 to bond and integrate the metal layer 2 and the fiber reinforced resin layer 3. Have. However, the metal layer 2 may be in the outermost layer as illustrated, or may be in either the innermost layer or the fiber reinforced resin layer. Moreover, when winding and shape | molding, it is preferable that the thickness of the metal layer 2 exists in the range of 0.01-0.15 mm, for example. If it is less than 0.01 mm, the cost for producing the metal foil is increased, and if it exceeds 0.15 mm, the weight reduction of the entire golf club shaft 1 may be impaired. The fishing rod basically has the same structure as that shown in FIG. 1, but it is also preferable that the tip is used by bonding and integrating a fiber-reinforced resin layer with a solid metal cylinder through an intermediate resin layer. . In the embodiment shown in FIG. 1, a water repellent layer H is formed on the surface of the innermost fiber reinforced resin layer. The intermediate resin layer 4 contains thermoplastic resin particles having a predetermined particle diameter (average particle diameter of 3 to 10 μm) and an imidazolesilane compound. Here, the particle diameter of the thermoplastic resin particles in the intermediate resin layer can be measured by observing the cross section of the golf club shaft with an optical microscope, a microscope using a CCD camera, SEM, or TEM. The average particle diameter of the thermoplastic resin particles in the intermediate resin layer in the present invention is an average value obtained by measuring the particle diameters of at least 10 particles.

Here, as the resin constituting the intermediate resin layer, it is preferable to use a resin composition in which thermoplastic resin particles having an average particle diameter of 3 to 10 μm are blended in advance. At this time, the average particle diameter of the thermoplastic resin particles to be blended in the resin composition is preferably measured by the median diameter obtained from the particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer.

The fiber reinforced resin layer 3 is composed of a composite material composed of reinforced fibers and a matrix resin (for example, a thermosetting resin such as an epoxy resin). Examples of the adhesion structure of the intermediate resin layer 4, the metal layer 2, and the fiber reinforced resin layer 3 are shown in FIGS. FIG. 3 is a more preferable example.

  In the example shown in FIG. 2, a thermoplastic resin is used as a base resin between the metal layer 2 and the fiber reinforced resin layer 3 including the reinforcing fiber (group) 5 and the thermosetting matrix resin 6. An intermediate resin layer 4 serving as an adhesive resin layer including the resin 8 (the thermoplastic resin continuous phase 8a and the thermoplastic resin particle phase 8b) is interposed. When the thermoplastic resin particles having a predetermined particle diameter are blended in the intermediate resin layer 4, the particles serve as a spacer to ensure a desired thickness of the intermediate resin layer 4, and the metal layer 2 and the fiber reinforced resin layer 3. A desirable interlayer thickness can be secured between the two. Moreover, the intermediate resin layer 4 can be toughened by blending the thermoplastic resin particles, and the contained particles can also exhibit a pinning effect against cracks, for example. The thermoplastic resin particles having the predetermined particle diameter contained in the intermediate resin layer 4 are at least partially in a continuous phase form (linear or film-like continuous phase form) by, for example, fusion as shown in the figure. The thermoplastic resin continuous phase portion 8a and the thermoplastic resin particle phase portion 8b that are substantially left in the form of particles are mixed. Thus, by including the thermoplastic resin in the intermediate resin layer 4 in the form of a continuous phase, the adhesion between the metal layer 2 and the fiber reinforced resin layer 3 is improved. In particular, when a stress in a peeling mode such as peeling from the fiber reinforced resin layer 3 is applied to the metal layer 2, the thermoplastic resin in the intermediate resin layer 4 has the form of the continuous phase 8a. It is considered that it acts as an anchor for the thermosetting resin matrix resin 7 to be configured, and the adhesiveness is improved. Here, the thermosetting matrix resin 6 constituting the fiber reinforced resin layer 3 and the thermosetting resin base material resin 7 constituting the intermediate resin layer 4 may have the same resin composition or different thermosetting properties. Resin may be used.

  The thermosetting resin 7 constituting the intermediate resin layer 4 contains an imidazole silane compound. By including this imidazole silane compound, the adhesion between the intermediate resin layer 4 and the metal layer 2, particularly the metal layer 2 containing titanium, is improved. In particular, deterioration of adhesiveness after exposure to high temperature and high humidity can be suppressed, and the resistance to environmental exposure can be improved. The blending amount of the imidazole silane compound in the thermosetting resin is preferably 0.1% by weight or more and 2.0% by weight or less with respect to the weight of the resin composition. That is, when the amount of the imidazole silane compound is less than 0.1% by weight, the effect of improving adhesiveness is small, which is not preferable. If it exceeds 2.0% by weight, especially when an epoxy resin is used as the thermosetting resin, the imidazole silane compound also acts as a curing agent or a curing accelerator, so that curing is excessively accelerated. Therefore, it is not preferable. In this case, it is also one of preferable usage forms that a solution obtained by melting an imidazolesilane compound in an organic solvent such as ethanol is applied to a metal adhesion surface, dried and subjected to a surface treatment. Thus, the purpose of use of the imidazolesilane compound in the present invention is to improve the adhesion to the metal layer 2 in particular, and is used as a curing agent or curing accelerator for a thermosetting resin or as a rust preventive for metals. is not.

  FIG. 3 shows a more preferable embodiment. That is, in the golf club shaft 11 shown in FIG. 3, the intermediate resin layer 12 is in the boundary with the fiber reinforced resin layer 3, the reinforcing fiber 5 of the fiber reinforced resin layer 3, and the thermoplastic resin, particularly the continuous phase heat. The mixed layer 12b in which the plastic resin 8a is mixed is formed unevenly. The portion closer to the metal layer 2 than the mixed layer 12b has substantially the same form as the intermediate resin layer 4 shown in FIG. Thus, by mixing the reinforcing fiber 5 and the thermoplastic resin continuous phase 8a, the thermoplastic resin continuous phase 8a acts as an anchor for the reinforcing fiber group 5, and the intermediate resin layer 12 and the fiber reinforced resin layer 3 Adhesion is greatly improved. It is more preferable that each thermoplastic resin continuous phase 8a is in contact with a plurality of reinforcing fibers 5.

  The thickness of the intermediate resin layer 12 is preferably 15 μm or more and 150 μm or less, for example, and the maximum thickness of the mixed layer 12b is preferably 10 μm or more and 100 μm or less. FIG. 3 shows the thickness of the intermediate resin layer 12 as Ta, and the thickness of the mixed layer 12b with the thermoplastic resin continuous phase 8a as the reinforcing fiber group 5 as Tpf. Ta and Tpf can be measured by observing the cross section of the composite material with an optical microscope, a microscope using a CCD, SEM, and TEM.

  If the thickness Ta of the intermediate resin layer 12 is less than 15 μm, the intermediate resin layer 12 is too thin and the layer is easily broken, which is not preferable. On the other hand, when the thickness is larger than 150 μm, the intermediate resin layer 12 is too thick, so that the weight of the intermediate resin layer 12 increases and the weight reduction as a composite material is impaired.

  Furthermore, the thickness Tpf of the mixed layer 12b in which the reinforcing fiber 5 and the thermoplastic resin continuous phase 8a are mixed may be less than 10 μm, but is preferably 10 μm or more because the adhesiveness is further improved. On the other hand, if it is thicker than 100 μm, it is not preferable because it is too thick and the weight of the intermediate resin layer 12 increases. Moreover, it is not preferable to mix the thermoplastic resin continuous phase 8a thicker than 100 μm between the reinforcing fibers because it may be very difficult from the viewpoint of molding.

  Regarding the thermoplastic resin particles blended in the intermediate resin layer 12, it is preferable that a continuous phase having the above-described continuous shape and a particle shape having an average particle diameter of 3 μm or more and 10 μm or less are mixed. The intermediate resin layer 12 is composed of a base resin 7 made of a thermosetting resin and a thermoplastic resin. The thermoplastic resin has a particle shape with an average particle size of 3 μm to 10 μm and is mixed with the thermosetting resin. Has been. By making the particle shape 3 μm or more and 10 μm or less, it is easy to process the intermediate resin layer 12 into a film shape or the like before molding. Further, in the curing and molding process, the thermoplastic resin is interposed between the reinforcing fibers. It becomes easy to form the layer 12b in which the reinforcing fiber and the thermoplastic resin are mixed after molding. For this reason, it is preferable that the thermoplastic resin mixed in the particle shape forms a continuous phase having a continuous shape, and a part of the thermoplastic resin is present in the particle shape.

  The shape of the thermoplastic resin in the intermediate resin layer after molding can be measured by observing with an optical microscope, a microscope using a CCD, SEM, and TEM, similarly to the measurement of the thickness of the intermediate resin layer.

In addition, the resin composition itself constituting the intermediate resin layer 12 in the present invention is measured based on ASTM D 5045-96 “Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy Rate of Matter Release”. The rate (Strain Energy Release Rate) G _IC is preferably 400 J / m ² or more and 1000 J / m ² or less. A G _IC of less than 400 J / m ² is not preferable because the strain energy release rate is too low and the destruction of the intermediate resin layer 12 proceeds relatively easily. G _IC can be improved by mixing the thermoplastic resin in the intermediate resin layer 12 in a continuous phase having a continuous shape. Further, by increasing the mixing amount of the thermosetting resin of the thermoplastic resin, it is possible to improve the G _IC. On the other hand, in order to make G _IC larger than 1000 J / m ^2, it is necessary to mix a larger amount of thermoplastic resin. However, if the amount of the thermoplastic resin mixed is too large, the resin composition may have a film shape or the like. This is not preferable because it becomes difficult to process and there is a concern that the heat resistance or elastic modulus of the resin layer may decrease.

  In order to at least partially make the thermoplastic resin into a continuous phase by fusion or the like, it is preferable to mold at a temperature equal to or higher than the melting point (or softening point) of the thermoplastic resin particles. When the intermediate resin layer 12 and the fiber reinforced resin layer 3 are molded simultaneously in order to allow the particles to enter between the reinforced fibers, or when a cured fiber reinforced resin is used, the surface roughness is equal to or larger than the particle diameter of the particles. A method of blasting the adhesive surface can also be adopted.

  If it is difficult to measure the strain energy release rate of the intermediate resin layer itself, pull the metal layer from the fiber reinforced resin layer using a test piece in which the fiber reinforced resin layer and the metal layer are bonded and integrated through the intermediate resin layer. It is also possible to evaluate the adhesion by performing a peeling test.

  In this case, the peeling torque measured by the climbing drum peel method based on ASTM D 1781-98 (1998) is preferably 10 N · mm / mm or more, more preferably 20 N · mm / mm or more. When evaluating the adhesiveness of the intermediate resin layer, an evaluation method using an opening mode such as a strain energy release rate and a peeling torque is more preferable than a shear mode evaluation method.

  Moreover, it is preferable that the metal layer layer in this invention is inserted in the fiber reinforced resin layer. By interpolating the metal layer in the fiber reinforced resin layer, compared to the case where the metal layer is provided only in the outermost layer or the innermost interior, the adhesion area between the fiber reinforced plastic layer and the metal layer can be increased. When a bending load or the like is applied to the tubular body, it is possible to reduce the load applied to the tubular body per one intermediate resin layer, and it is possible to suppress peeling between the metal and the fiber reinforced resin layer. Is preferred.

The melting point or softening point of the thermoplastic resin is preferably 200 ° C. or lower. In the present invention, the thermoplastic resin in the intermediate resin is once melted or softened by molding the composite material at a temperature equal to or higher than the melting point or softening point of the thermoplastic resin and at an appropriate pressure condition. The thermoplastic resin can be easily mixed in the form of a continuous phase. When the melting point or softening point of the thermoplastic resin is higher than 200 ° C., the molding temperature of the composite material needs to be higher than 200 ° C., which is not preferable because the molding temperature becomes too high. The melting point of the thermoplastic resin in the present invention is a value measured by DSC at a heating rate of 10 ° C./min in accordance with JIS-K7121. The softening point is a value obtained by measuring the Picad softening temperature in accordance with JIS-K7206.

In the present invention, the reinforcing fibers constituting the reinforcing fiber group include inorganic fibers such as carbon fibers, glass fibers, and alumina fibers, organic fibers such as aramid fibers and polyamide synthetic fibers, and a combination of two or more thereof. Although it can be used, carbon fiber is particularly preferable as the reinforcing fiber. Since carbon fiber has a small specific gravity, high strength, and high elastic modulus, the specific strength and specific elastic modulus are large. It can be used and it is easy to control these characteristics.

  In the present invention, the thermoplastic resin is selected from the group of polyamide resin, polyester resin, polycarbonate resin, styrene resin, EVA resin, urethane resin, acrylic resin, polyolefin resin, and PPS resin. At least one kind of resin is preferred. In particular, a polyamide-based resin is more preferable because it has excellent adhesion to a thermosetting resin.

  The polyamide resin of the present invention includes polyamide 11, polyamide 12, polyamide 610, polyamide 612, and their copolyamide resins such as polyamide 66/6, 6/66/610, 6/66/612, 6/66 / Resin selected from 610/612.

  Of these, polyamide 11 and polyamide 12 are preferred because of their low water absorption.

  In the tubular body according to the present invention, steel, aluminum, an aluminum alloy, or the like can be used as the metal constituting the metal layer, but titanium or a titanium alloy is particularly preferable. That is, in the case of using the fiber reinforced resin having a light weight, high strength, and high elastic modulus as in the present invention, a titanium alloy having a light weight, high strength, and high elastic modulus is more preferable. Of these, β-15 alloy Ti-15V-3Cr-3Al-3Sn and α + β alloy Ti-6Al-4V are more preferred because of their high strength among titanium alloys.

  Further, the method for producing a tubular body of the present invention is a production method for producing a tubular body by thermoforming a thermosetting resin prepreg, wherein the molding is performed at a temperature equal to or higher than the melting point or softening point of the thermoplastic resin. It is characterized by doing. By thermoforming to a temperature equal to or higher than the melting point or softening point of the thermoplastic resin, it is possible to form a continuous phase by fusing the thermoplastic resins in the intermediate resin layer in the molding step. Even at a temperature equal to or higher than the softening point, the thermoplastic resin can be deformed and mixed between the reinforcing fibers by applying an appropriate pressure.

  In particular, when a particle-shaped thermoplastic resin is blended with the thermosetting resin constituting the intermediate resin layer, the viscosity of the thermosetting resin decreases during the temperature rising process, and the thermoplastic resin particles move. It becomes easy to be mixed between the reinforcing fibers, and further, by heating up to the melting point of the thermoplastic resin or more, the particles of the adjacent thermoplastic resin can be fused to form a continuous phase. . In this way, the thermoplastic resin is mixed between the reinforced fibers to form a mixed layer, and further, the thermoplastic resin particles are fused together to form a continuous phase, whereby the metal layer and the fiber reinforced resin layer are formed. It is possible to further improve the adhesion.

  A golf club shaft in which a pure titanium layer was bonded and integrated on the surface layer of a carbon fiber reinforced plastic layer was prepared, and hit ball durability was evaluated.

  The materials used are as follows.

A unidirectional prepreg sheet A (fiber basis weight: 116 g / m ² , fiber content: 76 wt%, fiber tensile elastic modulus: 375 GPa, matrix resin: epoxy resin) was used for the bias layer of the carbon fiber reinforced plastic layer.

A unidirectional prepreg sheet B (fiber basis weight: 125 g / m ² , fiber content: 76% by weight, fiber tensile elastic modulus: 295 GPa, matrix resin: epoxy resin) was used for the straight layer of the carbon fiber reinforced plastic layer.

However, the unidirectional prepreg sheet that forms the outermost layer of the fiber reinforced plastic layer (the outermost layer of the straight layer) is preliminarily laminated with a resin film for forming an intermediate resin layer on one surface of the unidirectional prepreg sheet B. Unidirectional prepreg sheet C was used.
The epoxy resin of the matrix resin constituting the unidirectional prepreg sheet is common to the unidirectional prepreg sheet A, the unidirectional prepreg sheet B, and the unidirectional prepreg sheet C.
The resin film laminated on the unidirectional prepreg sheet C is obtained by adding nylon fine particles (polyamide 12 fine particles SP500 manufactured by Toray Industries Inc., average particle size 5 μm, melting point 165 ° C.) to the epoxy resin of the matrix resin constituting the prepreg sheet. A resin composition containing 20% by weight with respect to weight and 1% by weight with respect to epoxy weight of imidazolesilane compound (IS-1000 manufactured by Nikko Materials Co., Ltd.) is processed into a film having a basis weight of 60 g / m ² . The unidirectional prepreg sheet C was prepared by placing this resin film on one surface of the prepreg sheet B and laminating it by pressing with a calender roll heated to 80 ° C.
As the titanium layer, a pure titanium plate having a thickness of 50 μm was used. The bonded surface of the pure titanium plate was polished with # 800 sanding paper and then washed with acetone.

[Example 1]
(Evaluation of golf club shaft)
A prepreg sheet A, a prepreg sheet B, and a pure titanium plate were used to form a golf club shaft using a mandrel.

  First, a prepreg sheet A cut into a predetermined shape as a bias layer on a tapered stainless steel mandrel having a tip diameter of 6 mmφ, a hand diameter of 13 mmφ, and a length of 1143 mm, has a fiber direction of +45 with respect to the mandrel axial direction. One layer was wound so that the angle was + 45 °, one layer was wound so as to be −45 °, then one layer was wound so as to be + 45 °, and another layer was wound so as to be −45 °. Further, two layers of the prepreg sheet B cut into a predetermined shape as a straight layer were wound so that the fiber direction was the same as the mandrel axis direction (angle of 0 ° with respect to the cylindrical axis direction). Furthermore, one layer of the unidirectional prepreg sheet C was wound as the outermost layer of the fiber reinforced plastic layer in the same manner as the unidirectional prepreg sheet B. However, the unidirectional prepreg sheet C was wound so as to be disposed on the outermost layer so that the resin film laminated in advance could be bonded to the titanium layer. Furthermore, as a titanium layer, the surface polished with sanding paper was disposed on the resin film side of the surface of the unidirectional prepreg sheet C wound around the mandrel and wound. Further, a wrapping tape was wound and cured by heating at 135 ° C. for 2 hours, and then the mandrel was removed to obtain a golf club shaft.

  As a result of cross-sectional observation of the obtained golf club shaft, an intermediate resin layer having a thickness (corresponding to Ta in FIG. 3) of 110 μm is formed between the outermost titanium layer and the carbon fiber reinforced plastic layer. In the resin layer, nylon fine particles (corresponding to 8b in FIG. 3) having an average particle diameter of 5 μm were observed. Further, some of the nylon fine particles entered the carbon fiber group constituting the carbon fiber plastic, and a mixed layer (corresponding to the mixed layer 12b in FIG. 3) in which the carbon fibers and the nylon fine particles were mixed was formed. The thickness of the mixed layer was 40 μm.

  Further, some nylon fine particles were integrated with each other to form a nylon continuous phase (corresponding to 8a in FIG. 3).

  A No. 3 iron head was attached to the obtained golf club shaft to make a No. 3 iron club, and then set in an air cannon tester, and a hit endurance test was conducted at a golf ball speed of 55 km / sec. As a result, even after hitting 3000 times, no peeling or the like was observed between the titanium layer and the carbon fiber reinforced plastic layer, and the impact durability test was passed.

The feel at impact was good with a feeling close to that of a steel shaft.
(Adhesion evaluation with titanium alloy layer)
In order to evaluate the adhesion of the unidirectional prepreg sheet C used in this example to the titanium alloy layer, a test piece for a climbing drum peel was prepared and the peeling torque was measured.
As the titanium alloy layer, a titanium alloy Ti-15V-3Cr-3Al-3Sn having a thickness of 0.15 mm, a length of 300 mm, and a width of 25 mm was used. The adhesive surface of the titanium alloy was polished and cleaned in the same manner as in Example 1.
Seven layers of the unidirectional prepreg sheet B used in Example 1 were stacked in a stacked configuration of [45/0 / −45 / 90/90 / −45 / 0], and the unidirectional prepreg sheet C was stacked on the outermost layer. A laminated material was prepared. The laminated material was 250 mm long and 25 mm wide. Further, the laminated material is placed on the titanium alloy so that the overlapping length is 250 mm and the width is 25 mm, and the adhesive surface of the titanium alloy is disposed on the resin film previously laminated on the unidirectional prepreg sheet C. Laminated.
Using an autoclave, under a pressure of 6 kg / cm ² , it was cured by heating at 135 ° C. for 2 hours to form five climbing drum peel test pieces.
Based on ASTM D 1781-98 (1998), the test was performed on the five test pieces prepared, the peel torque was measured, and the average value of the peel torque was obtained. As a result, it was 30 N · mm / mm.

[Example 2]
(Evaluation of golf club shaft)
A golf club shaft was formed in the same manner as in Example 1 except that the curing condition was 180 ° C. for 2 hours to obtain a golf club shaft.
As a result of cross-sectional observation in the same manner as in Example 1, an intermediate resin layer having a thickness (corresponding to Ta in FIG. 3) of 100 μm was formed between the outermost titanium layer and the carbon fiber reinforced plastic layer. Nylon fine particles were integrated with each other to form a nylon continuous phase (corresponding to 8a in FIG. 3) over a wide range in the layer.
In addition, nylon fine particles (corresponding to 8b in FIG. 3) having an average particle diameter of 5 μm were observed in part. Furthermore, a part of the nylon continuous phase entered the carbon fiber group constituting the carbon fiber plastic, and a mixed layer (corresponding to the mixed layer 12b in FIG. 3) in which carbon fibers and nylon fine particles were mixed was formed. The thickness of the mixed layer was 40 μm.

  As a result of performing the impact durability test in the same manner as in Example 1, even if the ball was hit 3000 times, no peeling was observed between the titanium layer and the carbon fiber reinforced plastic layer, and the impact durability test was passed.

The feel at impact was good with a feeling close to that of a steel shaft.
(Adhesion evaluation with titanium alloy layer)
A test piece for climbing drum peel was prepared in the same manner as in Example 1 except that the curing condition was 180 ° C. for 2 hours, and the peeling torque was measured. As a result, the average value of the peeling torque was 50 N · mm / mm.
(Strain energy release rate G _IC measurement of resin composition)
The strain energy release rate G _IC was measured using a cured resin obtained by heating only the resin composition constituting the resin film laminated on the unidirectional prepreg sheet C at 180 ° C. for 2 hours. The measurement was performed based on ASTM D 5045-96 “Standard Test Methods for Plane-Strain Fracture Tourness and Strain Energy Release Rate of Plastic Materials”.

As a result, G _IC was 700 J / m ² .

[Example 3]
(Evaluation of golf club shaft)
In Example 2, in addition to the outermost layer, the titanium layer is laminated between the −45 ° layer of the prepreg sheet A constituting the bias layer and the 0 ° layer of the prepreg sheet B constituting the straight layer. In the same manner as in No. 2, a golf club shaft was molded to obtain a golf club shaft.

As a result of cross-sectional observation in the same manner as in Example 1, the thickness (corresponding to Ta in FIG. 3) is between the titanium layer and the carbon fiber reinforced plastic layer disposed in the outermost layer and the carbon fiber reinforced plastic layer. An intermediate resin layer of 100 μm was formed, and the nylon fine particles were integrated with each other to form a nylon continuous phase (corresponding to 8a in FIG. 3) over a wide range in the intermediate resin layer.
In addition, nylon fine particles (corresponding to 8b in FIG. 3) having an average particle diameter of 5 μm were observed in part. Furthermore, a part of the nylon continuous phase entered the carbon fiber group constituting the carbon fiber plastic, and a mixed layer (corresponding to the mixed layer 12b in FIG. 3) in which carbon fibers and nylon fine particles were mixed was formed. The thickness of the mixed layer was 40 μm.

  As a result of performing the impact durability test in the same manner as in Example 1, even if the ball was hit 3000 times, no peeling was observed between the titanium layer and the carbon fiber reinforced plastic layer, and the impact durability test was passed.

  The feel at impact was good with a feeling close to that of a steel shaft.

[Comparative example]
(Evaluation of golf club shaft)
Example except that the resin composition constituting the resin film used in Example 1 is a resin composition not containing nylon fine particles and an imidazole silane compound (same as the matrix resin constituting the unidirectional prepreg sheet A). 2 to obtain a golf club shaft.
As a result of cross-sectional observation as in Example 1, almost no resin layer was formed between the outermost titanium layer and the carbon fiber reinforced plastic layer, and between the titanium layer and the carbon fiber reinforced plastic layer. It is considered that the resin constituting the disposed resin film flowed out during molding.
As a result of performing the impact durability test in the same manner as in Example 1, when the ball was hit 400 times, an abnormal sound was generated in the hitting sound. The test was stopped and the golf club shaft was inspected. It was confirmed that was peeled off.
(Adhesion evaluation with titanium alloy layer)
Example except that the resin composition constituting the resin film used in Example 2 is a resin composition not containing nylon fine particles and an imidazole silane compound (same as the matrix resin constituting the unidirectional prepreg sheet A). The climbing drum peel test piece was molded in the same manner as in No. 2, the peel torque was measured, and the average value was obtained.
(Strain energy release rate G _IC measurement of resin composition)
The strain energy release rate was measured in the same manner as in Example 5 using a cured resin obtained by heating only the resin composition constituting the resin film used in Comparative Example 1 at 180 ° C. for 2 hours. As a result, G _IC was 200 J / m ² .

It is a cross-sectional view of the tubular body which concerns on one embodiment of this invention. It is an expanded partial sectional view which shows the structural example of each layer adhesion part of the tubular body of FIG. It is an expanded partial sectional view which shows another structural example of each layer adhesion part of a tubular body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Golf club shaft 2 as a tubular body Metal layer 3 Fiber reinforced resin layer 4, 12 Intermediate resin layer 5 Reinforcing fiber (group)
6 Matrix resin of fiber reinforced resin layer 7 Base resin of intermediate resin layer 8 Thermoplastic resin 8a Thermoplastic resin continuous phase 8b Thermoplastic resin particle phase 12a Middle resin layer portion 12b near metal layer Mixed layer H Water repellent layer

Claims (7)

  It is a tubular body composed of a metal / fiber reinforced resin composite material in which a metal layer and a fiber reinforced resin layer are bonded and integrated through an intermediate resin layer, and the intermediate resin layer is a heat having an average particle diameter of 3 to 10 μm. A tubular body comprising plastic resin particles and an imidazolesilane compound.   The boundary part of the said intermediate | middle resin layer and the said fiber reinforced resin layer forms the mixed layer in which the thermoplastic resin which comprises the said particle | grain, and the reinforced fiber of the said fiber reinforced resin layer were mixed. Tubular body. Wherein the thermal particles of thermoplastic resin is present in the intermediate resin layer in a partially continuous phase forms even without small, tubular body according to claim 1 or 2.   The tubular body according to claim 1, wherein the thermoplastic resin particles are made of a polyamide-based resin.   The tubular body according to any one of claims 1 to 4, wherein the matrix resin of the fiber reinforced resin layer and the base resin of the intermediate resin layer are made of the same kind of resin.   The tubular body according to claim 5, wherein the same kind of resin is made of a thermosetting resin.   The tubular body according to any one of claims 1 to 6, wherein the metal layer includes a layer containing titanium.

Images