JP2020141918A - Golf club head and golf club - Google Patents

Abstract

To provide a golf club head and a golf club capable of improving a carry.SOLUTION: A golf club head 2 comprises a crown part 5, a sole part 6, and a face part 8 connected to the crown part 5 and the sole part 6. At least one of the crown part 5, the sole part 6, and the face part 8 has a high repulsion region including a carbon fiber reinforcement molded body, the carbon fiber reinforcement molded body has an arranged composite material and a resin hardened object. The composite material is formed of a carbon fiber bundle obtained by arranging a plurality of continuous carbon fibers, and a carbon nanotube adhered to respective surfaces of the carbon fibers.SELECTED DRAWING: Figure 2

Description

The present invention relates to a golf club head and a golf club.

Golf clubs with a golf club head and a shaft connected to the golf club head are already well known. For example, Patent Document 1 discloses a driver whose center of gravity depth can be adjusted. According to the driver of Patent Document 1, the depth of the center of gravity can be adjusted without changing the distance of the center of gravity of the driver, which is closely related to the ease of swinging the driver.

Japanese Unexamined Patent Publication No. 2016-120120

Among golf clubs, drivers in particular are required to further improve their skills to extend the flight distance.

An object of the present invention is to provide a golf club head and a golf club capable of extending a flight distance.

The golf club head according to the present invention includes a crown portion, a sole portion, and a face portion connected to the crown portion and the sole portion, and at least the crown portion, the sole portion, and the face portion. One has a high repulsion region including a carbon fiber reinforced molded body, the carbon fiber reinforced molded body has an arranged composite material and a resin cured product, and the composite material has a plurality of continuous carbon fibers. Is formed by the carbon fiber bundles in which the carbon fibers are arranged and the carbon nanotubes attached to the respective surfaces of the carbon fibers.

The golf club according to the present invention includes the golf club head and a shaft extending from the golf club head.

According to the present invention, the face portion is elastically deformed to its original shape by the repulsive force consisting of its own elastic force and the elastic force due to the high repulsion region. The repulsive force is applied to the golf ball from the face portion. Therefore, the golf club according to the present embodiment can apply a larger repulsive force to the golf ball, so that the flight distance can be extended.

It is a perspective view which shows the golf club which concerns on this embodiment. It is the schematic sectional drawing of the golf club head which concerns on this embodiment. It is the schematic sectional drawing of the crown part which concerns on this embodiment. It is the schematic explaining the structure of the composite material contained in the carbon fiber reinforced molded article. It is explanatory drawing which shows the structure of the attachment device which attaches carbon nanotube to carbon fiber. It is sectional drawing in the use state of the golf club head which concerns on this embodiment. It is the schematic which shows the test apparatus. It is a graph (1) which shows the test result. It is a graph (2) which shows the test result.

1. 1. Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, the face portion side is referred to as "front side", the side opposite to the face portion is referred to as "rear side", the crown portion side is referred to as "upper side", and the sole portion side is referred to as "lower side" with the golf club head as the center.

FIG. 1 is a perspective view showing a golf club according to the present embodiment. In FIG. 1, the front side of the x-axis (the direction side of the arrow) is the "face side", the back side of the x-axis (the side opposite to the direction of the arrow) is the "face back side", and the upper side of the z-axis (the direction side of the arrow) is " "Crown side", z-axis lower side (opposite direction of arrow) is "sole side", y-axis front side (arrow direction side) is "toe side", y-axis back side (opposite direction of arrow) Is referred to as the "heel side". The front side of the x-axis (direction side of the arrow) is the "front side", the back side of the x-axis (opposite the direction of the arrow) is the "rear side", and the upper side of the z-axis (direction side of the arrow) is the "upper side". The lower side of the axis (opposite the direction of the arrow) is also called the "lower side".

1-1 Overall configuration The golf club 1 shown in FIG. 1 corresponds to the first wood and includes a golf club head (hereinafter referred to as “head”) 2, a hosel 3, and a shaft 4. The tip of the shaft 4 is connected to the head 2 via a tubular hosel 3. A grip is attached to the base end of the shaft 4, although not shown. The hosel 3 can be omitted. When the hosel 3 is omitted, the shaft 4 is attached by inserting the tip directly into the head 2. The shaft 4 can be formed of steel (including stainless steel), a metal material such as aluminum or an alloy, a polymer material, a composite material in which various materials are combined, or the like.

As shown in FIGS. 1 and 2, the head 2 includes a crown portion 5 forming an upper surface, a sole portion 6 forming a lower surface, a face portion 8 forming a front surface, and a side portion 10 forming a side surface. To be equipped. The face portion 8 is connected to the crown portion 5 and the sole portion 6 on the front side. The side portion 10 is connected to the crown portion 5 and the sole portion 6 on the outer circumference of the head 2 excluding the face portion 8.

The head 2 has an outer shape in which a crown portion 5, a sole portion 6, a face portion 8, and a side portion 10 are integrated. The head 2 has an internal space 12 surrounded by a crown portion 5, a sole portion 6, a face portion 8, and a side portion 10.

The crown portion 5 is provided so as to cover the upper surface of the head 2, and has an outer layer 14 and an inner layer 15 as shown in FIG. The crown portion 5 in this figure has an outer layer 14, an inner layer 15, and an intermediate layer 16 composed of two layers arranged between the outer layer 14 and the inner layer 15, and shows a case where the crown portion 5 has a four-layer structure as a whole. .. The outer layer 14 is arranged on the outer surface of the head 2, and the inner layer 15 is arranged on the inner surface of the head 2 in contact with the inner space 12.

The crown portion 5 has a region in which the outer layer 14, the inner layer 15, and the intermediate layer 16 are formed of the carbon fiber molded body 21. The carbon fiber molded body 21 includes a carbon fiber bundle and a cured resin product. Each of the outer layer 14, the inner layer 15, and the intermediate layer 16 is formed by laminating one or more sheet-shaped prepregs in which a carbon fiber bundle is impregnated with a matrix resin. The carbon fiber molded body 21 does not contain carbon nanotubes, which will be described later. As the carbon fiber molded body 21, conventional CFRP (Carbon Fiber Reinforced Plastics) can be used.

The crown portion 5 according to the present embodiment has a high repulsion region 18 including a carbon fiber reinforced molded product 20. The high repulsion region 18 is provided in a part of the region in the plane direction of the crown portion 5. The position in the plane direction in which the high repulsion region 18 is provided can be arbitrarily selected. In the high repulsion region 18, the intermediate layer 16 is formed of the carbon fiber reinforced molded body 20. That is, the high repulsion region 18 is formed of an outer layer 14 and an inner layer 15 formed of the carbon fiber molded body 21, and an intermediate layer 16 formed of the carbon fiber reinforced molded body 20. In the intermediate layer 16 of the crown portion 5, the carbon fiber molded body 21 is replaced with the carbon fiber reinforced molded body 20 in the high repulsion region 18. In the intermediate layer 16 of the crown portion 5, the carbon fiber reinforced molded body 20 and the carbon fiber molded body 21 are integrally connected in the plane direction at the outer edge of the high repulsion region 18. That is, the carbon fiber reinforced molded body 20 and the carbon fiber molded body 21 are integrally connected at an end surface parallel to the thickness direction connecting the upper surface and the lower surface of the intermediate layer 16.

The carbon fiber reinforced molded product 20 has an arranged composite material and a cured resin product. The composite material is formed of a carbon fiber bundle in which a plurality of continuous carbon fibers are arranged, and carbon nanotubes (hereinafter, referred to as “CNT”) attached to the surfaces of the carbon fibers.

(Composite material)
The composite material will be described with reference to FIG. The composite material 22 of the present embodiment includes a carbon fiber bundle 23 in which a plurality of continuous carbon fibers 24 are arranged in one direction. The carbon fiber 24 has a diameter of about 5 to 20 μm, and is obtained by firing an organic fiber derived from fossil fuel or an organic fiber derived from wood or plant fiber.

Although only 10 carbon fibers 24 are shown in the drawings for the sake of explanation, the carbon fiber bundle 23 in the present embodiment can include 10 to 100,000 carbon fibers 24. The carbon fibers 24 constituting the carbon fiber bundle 23 maintain linearity without being substantially entangled with each other. The composite material 22 of the present embodiment including such carbon fibers 24 has a strip shape in which 3 to 30 carbon fibers 24 are arranged in the thickness direction.

The carbon fibers 24 maintain their linearity without being substantially entangled with each other. The entanglement of the carbon fibers 24 in the carbon fiber bundle 23 can be evaluated by the linearity between the carbon fibers 24.

CNT 25 is attached to the surface of each carbon fiber 24. The CNTs 25 are evenly dispersed and entangled on almost the entire surface of the carbon fibers 24 to form a structure having a network structure in direct contact or direct connection with each other. It is preferable that there are no dispersants such as surfactants or inclusions such as adhesives between the CNTs 25. Further, the CNT 25 is directly attached to the surface of the carbon fiber 24. The connection referred to here includes a physical connection (mere contact). In addition, the adhesion referred to here means a bond by Van der Waals force. Further, the "direct contact or direct connection" includes a state in which a plurality of CNTs are simply in contact with each other, and also includes a state in which a plurality of CNTs are integrally connected.

The CNT 25 attached to the carbon fiber 24 has a linear shape. The CNT 25 has a shape that can be evaluated as linear, highly linear, and the like when observed with a scanning electron microscope (SEM). Compared to the bent CNT, the linearly shaped CNT 25 can be isolated and dispersed in a dispersion liquid described later and adhered to the carbon fiber 24 while maintaining the length, which is a feature of the CNT 25. Can be expressed more greatly.

The length of the CNT 25 is preferably 0.1 to 50 μm. When the length of the CNT 25 is 0.1 μm or more, the CNTs 25 are entangled with each other and are directly connected to each other. Further, when the length of CNT 25 is 50 μm or less, it becomes easy to disperse evenly. On the other hand, if the length of the CNTs 25 is less than 0.1 μm, the CNTs 25 are less likely to be entangled with each other. Further, if the length of CNT 25 exceeds 50 μm, it tends to aggregate.

The CNT 25 preferably has an average diameter of 1 nm to 30 nm. When the diameter of CNT 25 is 30 nm or less, the CNT 25 is highly flexible, and a network structure can be formed on the surface of each carbon fiber 24. On the other hand, if the diameter of CNT 25 is more than 30 nm, the flexibility is lost and it becomes difficult to form a network structure on the surface of each carbon fiber 24. The diameter of the CNT 25 is an average diameter measured using a transmission electron microscope (TEM) photograph. More preferably, the CNT 25 has an average diameter of about 20 nm or less.

It is preferable that the plurality of CNTs 25 are uniformly adhered to the respective surfaces of the carbon fibers 24 in the carbon fiber bundle 23. Further, it is preferable that each CNT 25 exists on the surface of a single carbon fiber 24 without connecting the carbon fibers 24 to each other. The adhered state of CNT 25 on the surface of the carbon fiber 24 can be observed by SEM, and the obtained image can be visually evaluated.

The number of CNTs attached to the carbon fibers 24 can be evaluated by the thickness of the structure (the length of the structure in the radial direction of the carbon fibers). The average thickness of the structure at each of the 10 measurement positions within the measurement range is taken as the thickness of the structure so as to cover the measurement range of the predetermined length along the fiber axis direction of the carbon fiber 24 almost evenly. To do. The length of the measurement range is, for example, five times the upper limit of the length range of the CNT 25 described above. The thickness of the structure at the measurement position is determined as the average height at which the CNT 25 protrudes from the surface of the carbon fiber 24 at each location where the CNT 25 adheres in the circumferential direction at the measurement position. The height of the CNT 25 protruding from the surface of the carbon fiber 24 can be measured by SEM or the like. When measuring the height of the CNTs 25 protruding from the surface of the carbon fibers 24, when a plurality of CNTs 25 overlap, the length of the overlapping CNTs 25 to the part farthest from the surface of the carbon fibers 24. Measure the fiber. Further, the portion where the CNT 25 is not attached to the surface of the carbon fiber 24 (height “0”) is not used in the calculation.

The thickness (average) of the structure obtained as described above is 10 nm to 300 nm, preferably 10 nm to 100 nm, and more preferably 10 nm to 50 nm. When the thickness of the structure is 300 nm or less, the friction between the carbon fibers 24 on which the structure is formed is small and the handling such as molding is easy.

Further, at least a part of the surface of the carbon fiber 24 to which the plurality of CNTs 25 are attached is covered with a resin called a sizing agent. As the sizing agent, urethane emulsion or epoxy emulsion is generally used.

Returning to FIG. 2, the sole portion 6 and the face portion 8 are plate-shaped members formed by casting or forging using a lightweight metal such as a titanium alloy. When the face portion 8 swings, the golf ball collides with the face portion 8. By connecting the sole portion 6 and the face portion 8, a rounded boundary portion 9 is formed. The sole portion 6 has a groove portion 11 that is concave toward the internal space 12. The groove portion 11 has a U-shaped cross section so as to be elastically deformed in the x-axis direction. The groove portion 11 is adjacent to the boundary portion 9 and is formed along the y-axis from the toe side to the heel side.

1-2 Manufacturing Method Next, a manufacturing method of the crown portion 5 provided with the high repulsion region 18 according to the present embodiment will be described. The high-resilience region 18 includes a step of producing a composite material, a step of producing a high-strength prepreg to be a carbon fiber reinforced molded body, a step of superimposing the high-strength prepreg on the prepreg to be a carbon fiber molded body, and a step of curing the matrix resin. It can be produced by passing through.

The composite material 22 is run by immersing a carbon fiber bundle 23 containing a plurality of carbon fibers 24 in a CNT dispersion liquid (hereinafter, also simply referred to as a dispersion liquid) in which CNT 25 is isolated and dispersed, and each of the carbon fibers 24 is run. It can be manufactured by adhering CNT25 to the surface of the above. Hereinafter, each step will be described in order.

(Preparation of dispersion)
A CNT 25 produced as follows can be used for the preparation of the dispersion liquid. For CNT25, for example, a catalyst film made of aluminum and iron is formed on a silicon substrate by using a thermal CVD method as described in Japanese Patent Application Laid-Open No. 2007-126311, and fine particles of a catalyst metal for CNT growth are formed. It can be produced by contacting the catalyst metal with a hydrocarbon gas in a heated atmosphere.

As long as the CNTs contain as little impurities as possible, CNTs produced by other methods such as an arc discharge method and a laser evaporation method may be used. Impurities can be removed by annealing the manufactured CNT 25 in an inert gas at a high temperature. The CNT 25 produced in this way has a high aspect ratio and linearity with a diameter of 30 nm or less and a length of several hundred μm to several mm. The CNT 25 may be either single-layer or multi-layer, but is preferably multi-layer.

Using the CNT 25 prepared as described above, a dispersion in which the CNT 25 is isolated and dispersed is prepared. Isolation and dispersion refers to a state in which CNTs 25 are physically separated one by one and dispersed in a dispersion medium without being entangled, and the proportion of aggregates in which two or more CNTs 25 are aggregated in a bundle is 10%. Refers to the following states.

For the dispersion liquid, a homogenizer, a shearing force, an ultrasonic disperser, or the like is used to make the dispersion of CNT 25 uniform. As the dispersion medium, alcohols such as water, ethanol, methanol and isopropyl alcohol; organic substances such as toluene, acetone, tetrahydrofuran (THF), methyl ethyl ketone (MEK), hexane, normal hexane, ethyl ether, xylene, methyl acetate and ethyl acetate. A solvent can be used.

Additives such as a dispersant and a surfactant are not always required for the preparation of the dispersion liquid, but such additives may be used as long as the functions of the carbon fibers 24 and CNT 25 are not impaired.

(Adhesion of CNT)
The carbon fiber bundle 23 is immersed in the dispersion liquid prepared as described above and run under predetermined conditions, and mechanical energy is applied to the dispersion liquid to attach the CNT 25 to the surface of the carbon fiber 24.

The step of adhering the CNT 25 to the carbon fiber 24 will be described with reference to FIG. In the CNT attachment tank 40 in which the dispersion liquid 46 is housed, a plurality of guide rollers 42 for running the carbon fiber bundle 23 in the direction of arrow A are arranged. The guide roller 42 is a flat roller.

The carbon fiber bundle 23 is reliably supported by the guide roller 42 and can travel in the dispersion liquid 46 without shrinking. The carbon fibers 24 contained in the carbon fiber bundle 23 are pulled while being supported by the guide roller 42, so that the entanglement is reduced and the linearity is improved.

The plurality of guide rollers 42 allow the carbon fiber bundle 23 to travel at a predetermined depth in the CNT attachment tank 40 at a predetermined traveling speed without receiving an excessive load. Since the carbon fiber bundle 23 is not bent during traveling, the possibility that the carbon fibers 24 contained in the carbon fiber bundle 23 are entangled is reduced. The traveling speed of the carbon fiber bundle 23 is preferably about 1 to 20 m / min. The slower the traveling speed, the more linear the carbon fibers 24 in the carbon fiber bundle 23 can be.

The above-mentioned mechanical energy is applied to the dispersion liquid 46. This creates a reversible reaction state in which the CNT 25 is always dispersed and aggregated in the dispersion liquid 46.

When the carbon fiber bundle 23 containing a plurality of continuous carbon fibers 24 is immersed in the dispersion liquid 46 in the reversible reaction state, the reversible reaction state between the dispersed state and the aggregated state of the CNT 25 is also on the surface of the carbon fibers 24. Occurs. The CNT 25 adheres to the surface of the carbon fiber 24 when moving from the dispersed state to the aggregated state.

At the time of agglutination, a van der Waals force acts on the CNT 25, and the van der Waals force causes the CNT 25 to adhere to the surface of the carbon fiber 24. In this way, the carbon fiber bundle 23 in which the CNT 25 is attached to the surface of each of the carbon fibers 24 in the carbon fiber bundle 23 is obtained.

Then, sizing treatment and drying are performed to produce the composite material 22 of the present embodiment. The sizing treatment can be carried out by a general method using a general sizing agent. Drying can be achieved by placing the sizing-treated carbon fiber bundle 23 on, for example, a hot plate.

Subsequently, the high-strength prepreg can be produced by impregnating the composite material 22 with a matrix resin and semi-curing the matrix resin. The matrix resin is not particularly limited, and examples thereof include a thermosetting resin such as an epoxy resin and a thermoplastic resin such as a phenoxy resin and nylon. In the composite material 22, since the carbon fibers 24 in the carbon fiber bundle 23 are not substantially entangled with each other, the carbon fibers 24 are not entangled with each other even in the high-strength prepreg. Moreover, the CNT 25 is well adhered to the surface of each of the carbon fibers 24 in the carbon fiber bundle 23.

Since the high-strength prepreg in which the composite material 22 is impregnated with the matrix resin is extremely unlikely to reduce the strength due to the entanglement of the carbon fibers 24, particularly the tensile strength in the longitudinal direction, the characteristics of the carbon fiber bundle 23 are sufficient. It will be demonstrated. In addition to this, since CNT 25 is well adhered to the surface of each carbon fiber 24, the obtained high-strength prepreg can sufficiently exhibit the characteristics derived from CNT.

The high-strength prepreg produced as described above is cut to a predetermined length. The high-strength prepreg is appropriately laminated with the above-mentioned prepreg in a state where one layer or a plurality of layers are laminated, and is arranged in a predetermined mold. The high-strength prepreg to be laminated and the longitudinal direction of the carbon fibers of the prepreg can be arbitrarily set. For example, the carbon fibers contained in the outer layer 14, the inner layer 15, and the intermediate layer 16 composed of the two layers may be arranged so that the longitudinal direction of the carbon fibers intersects with the carbon fibers of the other overlapping layers. ..

In this state, the matrix resin is heat-cured to obtain a cured resin while applying pressure. Examples of the method of applying heat and pressure include press molding, autoclave molding, vacuum pressure molding, sheet winding method and internal pressure molding method. When an epoxy resin is used as the matrix resin, a cured resin product can be obtained by heating at 80 to 180 ° C. for 0.5 to 5 hours. As described above, the crown portion 5 is formed. The head 2 may be formed by integrally molding the crown portion 5 with the sole portion 6, the face portion 8, and the side portion 10.

1-3 Actions and Effects As described above, the golf club 1 according to the present embodiment is provided with the high repulsion region 18 in the crown portion 5, so that the repulsive force when colliding with the golf ball is increased, and the golf club 1 is more inclined to the golf ball. Great force can be applied. Hereinafter, description will be made with reference to FIG.

As shown in FIG. 6, when the player swings the golf club 1 and the head 2 collides with the golf ball 13, the head 2 gives an impact force to the golf ball 13. The golf ball 13 is elastically deformed so as to be crushed by the impact force.

On the other hand, the head 2 receives a reaction force of the same magnitude as the above-mentioned impact force from the golf ball 13. The head 2 is elastically deformed by the reaction force. That is, the face portion 8 is elastically deformed into a concave shape toward the internal space 12. The crown portion 5 is elastically deformed in the thickness direction so as to bulge upward by a backward force applied through the face portion 8. The groove portion 11 is elastically deformed so as to contract in the x-axis direction by a backward force applied through the face portion 8.

Further, the golf ball 13 moves to the front side together with the head 2 while being in contact with the face portion 8 due to the force of returning to the original shape. Therefore, the reaction force applied from the golf ball 13 to the face portion 8 is reduced. When the reaction force received from the golf ball 13 decreases, the head 2 elastically deforms to return to its original shape due to the repulsive force.

In the high repulsion region 18 of the crown portion 5, since the CNT 25 is interposed in the cured resin product between the carbon fibers 24, the energy loss due to the viscous characteristics of the cured resin product is reduced. Therefore, the high repulsion region 18 elastically deforms with good responsiveness to a change in reaction force. When the crown portion 5 returns to its original shape, it generates an elastic force that pushes the face portion 8 forward.

The face portion 8 is elastically deformed to its original shape by a repulsive force composed of its own elastic force and the elastic force pushed forward by the crown portion 5. The repulsive force is applied from the face portion 8 to the golf ball 13. The golf ball 13 pops out to the front side by the force of returning to its original shape and the repulsive force received from the face portion 8. Therefore, the golf club 1 according to the present embodiment can apply a larger repulsive force to the golf ball 13, so that the flight distance can be extended.

In a conventional golf club, the crown portion is formed of a carbon fiber molded body containing no CNT. Since the cured resin product between carbon fibers does not contain CNTs, the energy loss due to the viscous characteristics of the cured resin product between carbon fibers is large, and the face portion is delayed with respect to the operation of returning to the original shape. Elastically deforms. Therefore, the conventional golf club has a smaller repulsive force applied to the golf ball 13 than the golf club 1 of the present embodiment.

2. 2. Modifications The present invention is not limited to the above embodiment, and can be appropriately modified within the scope of the gist of the present invention.

In the case of the above embodiment, the case where the high repulsion region 18 is provided in a part of the region in the plane direction of the crown portion 5 has been described, but the present invention is not limited to this, and is provided in the entire crown portion 5. May be good.

In the case of the above embodiment, the crown portion 5 has a four-layer structure including an intermediate layer 16 composed of an outer layer 14, an inner layer 15, and two layers, and the intermediate layer 16 of the high repulsion region 18 has a carbon fiber reinforced molded body 20. However, the present invention is not limited to this. The crown portion 5 includes a case where the intermediate layer 16 is one layer or less and less than four layers as a whole, and a case where the intermediate layer 16 is three layers or more and five layers or more as a whole.

The high-resilience region 18 is not limited to the case where the intermediate layer 16 is the carbon fiber reinforced molded product 20, but also includes the case where at least one layer of the outer layer 14, the inner layer 15, and the intermediate layer 16 has the carbon fiber reinforced molded product 20. Further, the high repulsion region 18 may be formed only by the carbon fiber reinforced molded product 20.

In the case of the above embodiment, the case where the crown portion 5 has the high repulsion region 18 has been described, but the present invention is not limited to this, and at least one of the crown portion 5, the sole portion 6, and the face portion 8 has a high repulsion region. Including the case of having.

For example, a high repulsion region may be provided in at least a part of the face portion 8. For example, the face portion 8 may be integrally provided with the carbon fiber reinforced molded product 20 on at least a part of the surface on the internal space 12 side. The face portion 8 is elastically deformed to its original shape by the elastic force of the lightweight metal plate-shaped member and the elastic force of the carbon fiber reinforced molded body 20 to push it forward. A large repulsive force can be applied.

Further, in the case of the sole portion 6, a high repulsion region may be provided in at least a part of the groove portion 11. For example, the groove portion 11 may be integrally provided with the carbon fiber reinforced molded body 20 on at least a part of the surface on the internal space 12 side. The face portion 8 is elastically deformed to its original shape by a repulsive force consisting of an elastic force of a lightweight metal plate-shaped member and an elastic force of pushing forward by the groove portion 11 provided with the carbon fiber reinforced molded body 20. A greater repulsive force can be applied to the golf ball 13.

Further, the high repulsion region may be provided in any two or more of the crown portion 5, the face portion 8, and the groove portion 11.

3. 3. Examples Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

(sample)
A high-strength prepreg used for the carbon fiber reinforced molded product 20 was produced by the procedure shown in the above manufacturing method. As the CNT 25, MW-CNTs (Multi-walled Carbon Nanotubes) grown on a silicon substrate to a diameter of 10 to 15 nm and a length of 100 μm or more by thermal CVD were used.

The CNT 25 was washed with a 3: 1 mixed acid of sulfuric acid and nitric acid to remove the catalyst residue, and then filtered and dried. CNT25 was added to acetone as a dispersion medium to prepare a dispersion. The CNT 25 was pulverized using an ultrasonic homogenizer and cut to a length of 1 to 5 μm. The concentration of CNT25 in the dispersion was 0.05 wt% (= 500 wt ppm). This dispersion does not contain a dispersant or adhesive.

The CNT attachment tank 40 as shown in FIG. 5 was prepared, and the dispersion liquid 46 thus prepared was housed. Vibration, ultrasonic waves, and sway as mechanical energy were applied to the dispersion liquid 46.

As the carbon fiber bundle 23, T700SC-12000 (manufactured by Toray Industries, Inc.) was used. The carbon fiber bundle 23 contains 12,000 carbon fibers 24. The diameter of the carbon fiber 24 is about 7 μm, and the length is about 100 m. The carbon fiber bundle 23 was immersed in the dispersion liquid 46 and traveled at a speed of 3.5 m / min via the guide roller 42.

Then, a sizing treatment was carried out using an epoxy resin as a sizing agent, and the composite material 22 was prepared by drying on a hot plate at about 80 ° C. The composite material 22 had a strip shape in which 12 carbon fibers were lined up in the thickness direction.

Further, the composite material was impregnated with an epoxy resin as a matrix resin to prepare a high-strength prepreg. The volume content of the resin in the high-strength prepreg was 30%. The basis weight of the composite material was 180 g / m ² .

The high-strength prepreg was cut out to prepare a sample according to an example having a size of 15 mm in width, 300 mm in length × 0.8 mm in thickness.

For comparison, a conventional CFRP sample was prepared in the same manner as in the examples except that the composite material was changed to a carbon fiber bundle in which CNTs were not attached to the surface of the carbon fibers.

(Test equipment)
Subsequently, the repulsive force characteristics of each sample 63 were evaluated using the test device 50 shown in FIG. 7. The test device 50 includes a rectangular plate-shaped base 52, a sample support portion 54 provided on one end side surface of the base 52 in the longitudinal direction, and a rotation provided on the other end side surface of the base 52 in the longitudinal direction. A body support portion 56 is provided. The sample support portion 54 is designed to fix one end of the sample 63. The rotating body support portion 56 has a pair of columns 57 and a rotating body 58 rotatably supported by the columns 57. The rotating body 58 has a rotating shaft 59 supported by a support column 57, a pair of supporting rods 60 connected to the rotating shaft 59, and an action shaft 61 spanned between the tips of the supporting rods 60.

(Test method and results)
First, one end of the sample 63 according to the embodiment is fixed to the sample support portion 54. The other end of the sample 63 fixed to the sample support portion 54 is a free end. The sample 63 is fixed in a range of 50 mm from one end by the sample support 54 so that the length from the sample support 54 to the other end is 250 mm. The rotating body support portion 56 is fixed to the base 52 so that the action shaft 61 comes into contact with the sample 63 at a position 235 mm from the sample support portion 54 and the other end of the sample 63 can be deformed 29 mm downward.

Next, five types of weights of 1.0 g, 3.0 g, 4.5 g, 9.0 g, and 16.0 g were prepared. A weight is placed on the sample 63 at a position 230 mm from the sample support portion 54. In this state, the rotating body 58 is rotated in the direction of the arrow in the figure. As the rotating body 58 rotates, the action shaft 61 comes into contact with the position of 235 mm from the sample support portion 54 of the sample 63. Further rotation of the rotating body 58 causes the sample 63 to be pushed down by the action shaft 61, and the other end side is elastically deformed downward with the sample support portion 54 as the center. When the sample 63 is deformed 29 mm downward, it separates from the action axis 61 and elastically deforms upward to return to its original shape. The operation of the sample 63 to return to its original shape causes the weight placed on the sample 63 to be flipped and raised. At this time, the highest reaching point (height) of the raised weight was measured. Each sample was measured 6 times.

The results are shown in Table 1, FIG. 8 and FIG. FIG. 8 is a graph showing the average value of the measured heights of 6 times. The vertical axis is the height (mm), the horizontal axis is the weight of the weight (g), ◇ is an example, and □ is a comparative example. The result is shown. FIG. 9 is a graph showing the ratio of the average value of the 6 times of heights measured in the example to the average value of the 6 times of heights measured in the comparative example as a height ratio, and the vertical axis is the height ratio. (%), The horizontal axis represents the weight (g) of the weight.

From the above results, it was confirmed that the highest achievement points of the examples were higher than those of the comparative examples in all the weights. The height ratio of the examples to the comparative examples is 107.5% to 116.1% on average, the height ratio of the examples is 7.5% or more higher, and the weight of the weight is heavier. Has also grown. From this, it was shown that the carbon fiber reinforced molded product can obtain a higher repulsive force than the conventional carbon fiber molded product, and when a larger load is applied, the difference from the conventional one becomes larger.

From the above, the carbon fiber reinforced molded product can exert a higher repulsive force than the conventional carbon fiber molded product that does not contain CNT, so that when applied to the head as a high repulsive region, the flight distance can be extended. it can.

1 ... Golf club, 2 ... Head, 3 ... Hosel, 4 ... Shaft, 5 ... Crown part, 6 ... Sole part, 8 ... Face part, 9 ... Boundary part, 10 ... Side part, 11 ... Groove part, 12 ... Internal space , 13 ... Golf ball, 14 ... Outer layer, 15 ... Inner layer, 16 ... Intermediate layer, 18 ... High resilience region, 20 ... Carbon fiber reinforced molded body, 21 ... Carbon fiber molded body, 22 ... Composite material, 23 ... Carbon fiber bundle , 24 ... carbon fiber, 40 ... attachment tank, 42 ... guide roller, 46 ... dispersion, 50 ... test equipment, 52 ... base, 54 ... sample support, 56 ... rotating body support, 57 ... support, 58 ... Rotating body, 59 ... Rotating shaft, 60 ... Support rod, 61 ... Axis of action, 63 ... Each sample

Claims (5)

Crown part and
With the sole part
A face portion connected to the crown portion and the sole portion,
With
At least one of the crown portion, the sole portion, and the face portion has a high repulsion region including a carbon fiber reinforced molded product.
The carbon fiber reinforced molded product has an arranged composite material and a cured resin product.
The composite material was formed of a carbon fiber bundle in which a plurality of continuous carbon fibers were arranged and carbon nanotubes attached to the surfaces of the carbon fibers.
Golf club head. It has an internal space surrounded by the crown portion, the sole portion, and the face portion.
The sole portion has a groove portion that is concave toward the internal space.
The groove has the high repulsion region.
The golf club head according to claim 1. The crown portion has an outer layer, an inner layer, and an intermediate layer arranged between the outer layer and the inner layer.
The high repulsion region
The outer layer and the inner layer are formed of a carbon fiber molded product having a carbon fiber bundle and a cured resin product.
The intermediate layer is formed of the carbon fiber reinforced molded product.
The golf club head according to claim 1 or 2. The golf club head according to any one of claims 1 to 3, wherein the carbon nanotube has a length of 0.1 μm to 50 μm and a diameter of 1 nm to 30 nm. The golf club head according to any one of claims 1 to 4.
A shaft extending from the golf club head and
A golf club equipped with.

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