JP7708550B2 - FRP materials - Google Patents

Description

The present invention relates to FRP components.

Patent Document 1 discloses a technique for laminating multiple coating layers when forming a coating layer that improves the design of the surface of the main body of sports equipment, etc. It also mentions the use of a polishing process that is expected to have an anchoring effect in order to improve adhesion between coating layers, but issues include insufficient adhesion between coating layers and, in the case of coating layers that contain lustrous materials, the lustrous materials impairing adhesion between coating layers. Patent Document 1 discloses a paint that prevents peeling between coating layers when multiple coating layers are laminated by adding an adhesion promoter to the paint.

JP 2001-327635 A

However, for example, when a paint layer is placed on the surface side of a fiber-reinforced resin layer, the conventional technology is still insufficient in terms of improving paint adhesion, and there is room for improvement.

The present invention was made based on the above concerns, and aims to obtain an FRP component that can improve the adhesion of paint to the surface side of the fiber-reinforced resin layer.

The FRP member of the present embodiment has a fiber reinforced resin layer, a paint layer located on the surface side of the fiber reinforced resin layer, and a blast treated layer located on the surface side of the paint layer, wherein a plurality of the paint layers are provided, a plurality of the blast treated layers are provided on the surface sides of the plurality of paint layers , a belt abrasive layer is located on the surface side of the fiber reinforced resin layer, and a center line average roughness Ra1 of the outer circumferential surface of the fiber reinforced resin layer is greater than a center line average roughness Ra2 of the outer circumferential surface of the paint layer .

The fiber-reinforced resin layer may be cylindrical, the paint layer may be cylindrical, and the blasted layer may be cylindrical.

The blasted layer may be a water blasted layer.

According to this embodiment, it is possible to obtain an FRP component that can improve the adhesion of paint to the surface side of the fiber-reinforced resin layer.

1A and 1B are diagrams illustrating an example of a golf club shaft and a golf club. 1 is a cross-sectional view showing a simplified structure of a golf club shaft. 1 is a graph showing the measurement results of a roughness curve obtained by a water blasting process. 1 is a graph showing the measurement results of a roughness curve obtained by a belt polishing process. 5 is a graph showing the measurement results of roughness curves obtained by belt polishing treatment under conditions different from those of FIG. 4 . 13 is an experimental photograph for explaining the difference in adhesion between water blasting treatment and belt polishing treatment. FIG. 7 is a partial schematic diagram of FIG. 6 .

Figure 1 shows an example of a golf club shaft 10 and a golf club 20, which are examples of applications of the FRP member according to this embodiment. The golf club 20 is completed by attaching a head 30 to the tip side (tip side) of the golf club shaft 10 and attaching a grip 40 to the base end side (butt side) of the golf club shaft 10. Note that while Figure 1 shows an example of an iron club using an iron head as the head 30, this embodiment can also be applied to a driver club using a driver head as the head 30 and a putter club using a putter head as the head 30.

The golf club shaft 10 is a golf club shaft made of FRP (Fiber Reinforced Plastics), which is made by winding and heat-curing multiple layers of prepregs in which reinforced fibers are impregnated with thermosetting resin. For example, prepregs in which the fiber direction is aligned in a predetermined direction can be used as the prepregs. In addition, angle layers may be provided as prepregs according to strength and rigidity, and metal or resin may be provided between the prepregs or in the innermost layer. For example, the golf club shaft 10 may be an FRP having at least two or more layers laminated, with the outermost layer being FRP. The "outermost layer" here means the outermost layer of the golf club shaft 10 before the undercoat (undercoat), topcoat (topcoat), water blasting treatment, and final painting described below. There is a degree of freedom in the number, type, and number of windings (number of plies) of the prepregs used, and various design changes are possible. In other words, the configuration of the golf club shaft 10 before the undercoat (undercoat), topcoat (topcoat), water blasting, and final painting described below is not important (a person skilled in the art can select it as appropriate).

The golf club shaft 10 has a tapered shape that gradually narrows from the base end (butt side) to the tip end (tip side) (the tapered shape of the golf club shaft 10 is exaggerated in Figure 1).

In this embodiment, a base coat (undercoat) is applied to the outer peripheral surface of the golf club shaft 10, followed by a water blasting treatment and then a top coat (top coat). The top coat (top coat) is usually applied in multiple steps, in which case the first top coat (top coat) is applied followed by a water blasting treatment, and the second top coat (top coat) is applied followed by a water blasting treatment, and so on. Note that a commonly known polishing treatment may be applied before the base coat (undercoat) is applied to the outer peripheral surface of the golf club shaft 10. For example, a belt polishing layer may be located on the surface (side) of the fiber reinforced resin layer of the golf club shaft 10.

The golf club shaft 10 is completed by repeating the above-mentioned undercoat (undercoat), topcoat (topcoat) and water blasting treatment, followed by a final coating, but the golf club shaft (FRP member) 10 in this specification is assumed to be in a state where the final coating has not been applied. One of the purposes of the golf club shaft (FRP member) 10 in this embodiment is to prevent coating defects (to improve paint adhesion), but the coating (paint) mentioned here does not mean the final coating, but rather the undercoat (undercoat) and topcoat (topcoat) applied with a water blasting treatment in between. In addition, the coating layer immediately before the final coating (the outermost coating layer) does not need to be water blasted.

Figure 2 is a cross-sectional view showing a simplified structure of a golf club shaft (FRP member) 10. The golf club shaft 10 has a fiber-reinforced resin layer 100 constituting the outermost layer of the golf club shaft 10, a paint layer (e.g., undercoat layer) 200 located on the surface (side) of the fiber-reinforced resin layer 100, a blast-treated layer 300 located on the surface (side) of the paint layer 200, a paint layer (e.g., top paint layer) 400 located on the surface (side) of the blast-treated layer 300, and a blast-treated layer 500 located on the surface (side) of the paint layer 400.

In FIG. 2, the fiber reinforced resin layer 100, the paint layer 200, the blasted layer 300, the paint layer 400, and the blasted layer 500 are drawn in a planar manner, but when the golf club shaft 10 is an FRP member, the fiber reinforced resin layer 100, the paint layer 200, the blasted layer 300, the paint layer 400, and the blasted layer 500 are configured in a cylindrical shape. Note that when the FRP member is applied to a member that is not cylindrical, the fiber reinforced resin layer, the paint layer, and the blasted layer do not have to be cylindrical.

In FIG. 2, two paint layers 200 and a paint layer 400 are depicted as the multiple paint layers, and two blasted layers 300 and a blasted layer 500 are depicted as the multiple blasted layers provided on the surfaces (sides) of the two paint layers 200 and the paint layer 400. However, three or more paint layers may be provided as the multiple paint layers, and three or more blasted layers may be provided as the multiple blasted layers provided on the surfaces (sides) of the three or more paint layers. That is, multiple paint layers may be provided, and multiple blasted layers may be provided on the surface side of the multiple paint layers.

The blasted layer is a treatment layer applied to the surface of the paint layer and constitutes a part of the paint layer (it is not a treatment layer separate from the paint layer). In addition, the paint layer depicted as a single layer in Figure 2 may be laminated with multiple paint layers.

In this embodiment, the paint layer 200 and the paint layer 400 located on the surface (side) of the fiber-reinforced resin layer 100 are provided with a blast-treated layer 300 obtained by blasting the surface of the paint layer 200, and a blast-treated layer 500 obtained by blasting the surface of the paint layer 400, thereby successfully improving the adhesion of the paint to the surface (side) of the fiber-reinforced resin layer 100. More specifically, the blast-treated layer 300 and the blast-treated layer 500 are preferably water-blast-treated layers formed by performing water-blasting. The water-blasting process may be read as a wet-blasting process.

Water blasting is a surface treatment method that uses three elements: particles, liquid, and air. The particles act as an abrasive to scrape, hit, and polish the surface of the object to be treated, and can be selected from types such as ceramic, resin, and metal. The liquid transports the particles to the object to be treated, cools it, and removes deposits and shavings, as well as exerting a water film effect. The air accelerates the particles and liquid, and atomizes the liquid. Water blasting has features (technical advantages) such as a wide range of particle sizes, shapes, and materials to choose from, high fluid controllability, and little particle residue.

In water blasting, the projected abrasive scrapes off a thin layer of the surface of the object to be treated, including any foreign matter, at a submicron level, while the water washes away the surface of the object to be treated, leaving less particle residue regardless of the material of the particles attached, simplifying the removal (cleaning) process compared to commonly known polishing processes. Furthermore, the surface roughening effect, which creates a matte finish (similar to the surface of frosted glass) by creating uniform, fine irregularities on the surface of the object to be treated, can improve the adhesion of the surface of the object to be treated (improving paint adhesion).

In this embodiment, the center line average roughness Ra1 of the outer peripheral surface of the fiber reinforced resin layer 100 is larger than the center line average roughness Ra2 of the outer peripheral surface of the paint layer 200 (paint layer 200 provided with blasted layer 300) and/or the paint layer 400 (paint layer 400 provided with blasted layer 500). In addition, when polishing (e.g., belt polishing) is performed on the outer peripheral surface of the fiber reinforced resin layer 100, the center line average roughness Ra1 of the outer peripheral surface of the fiber reinforced resin layer 100 that has been polished may be used as a reference. In this way, by optimally setting the center line average roughness Ra1 and Ra2, the adhesion of the paint to the surface (side) of the fiber reinforced resin layer 100 can be further improved.

The size of the center line average roughness Ra2 is not specifically limited, but is preferably, for example, 0.2 μm or more and 4.0 μm or less, and the upper limit of the center line average roughness Ra2 is more preferably 3.5 μm or less, even more preferably 3.0 μm or less, even more preferably 2.0 μm or less, and most preferably 1.0 μm or less.

The center line average roughness Ra1 must be greater than the center line average roughness Ra2, and is defined by the center line average roughness of the surface of the fiber reinforced resin layer 100 itself when no surface treatment is applied to the outer peripheral surface of the fiber reinforced resin layer 100. When the outer peripheral surface of the fiber reinforced resin layer 100 is subjected to a belt polishing treatment, it is defined by the center line average roughness of the belt polishing treatment layer. The size of the center line average roughness Ra2 is not specifically limited, but is, for example, 0.5 μm or more and 15.0 μm or less.

In the above embodiment, a golf club shaft 10 is used as an FRP member, but other members such as a fishing rod can also be used as the FRP member. The FRP member does not necessarily have to be cylindrical. In other words, the application of the FRP member is not limited to golf club shafts, and the FRP member of this embodiment can be applied to all types of FRP members, both current and future. Furthermore, when the FRP member is a cylindrical member, a circular cylindrical member, a cylindrical member having a constant diameter in the axial direction, or a cylindrical member having a tapered shape that contracts and expands in the axial direction may be used.

In the above embodiment, the water blasting process (layer) has been described as an example of the blasting process (layer). However, it is also possible to apply a blasting process (layer) other than the water blasting process (layer). For example, it is also possible to apply a dry blasting process (layer) that does not use water. In other words, the blasting process (layer) can be applied to all blasting processes that roughen the surface of a workpiece by spraying particles (abrasives, polishing powder).

The effects of the present invention will be explained below using examples and comparative examples. Note that the present invention is not limited in any way by the following examples.

<Experiment-1>
The surface of the paint layer formed on the outer peripheral surface of the fiber reinforced resin layer was subjected to the following treatment.
(1) Example where water blasting was performed (2) Example where belt polishing was performed (3) Example where belt polishing (low) was performed (3) was performed under conditions that were changed to those that could not be polished sufficiently compared to (2). Figures 3 to 5 are graphs showing the measurement results of the roughness curves from (1) to (3). The roughness curves shown in Figures 3 to 5 were obtained using a VR-5000 manufactured by Keyence. As shown in Figures 3 to 5, the surface roughness by the water blasting treatment could be made smaller than that by the belt polishing treatment. The measurement results of the center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS) for each example are shown in Tables 1 to 3 below.

Table 1 shows the measurement results after water blasting, Table 2 shows the measurement results after belt polishing, and Table 3 shows the measurement results after belt polishing (low). As shown in Table 1, the center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS) were all smallest after water blasting. The center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS) were measured using a method that conforms to JIS B0601.

<Experiment 2>
Next, similarly to the above-mentioned <Experiment-1>, the surface of the coating layer formed on the outer peripheral surface of the fiber-reinforced resin layer was subjected to each of the surface treatments (1) to (3), but the measurement position was changed from the reference position (0 mm) to positions of 100 mm, 400 mm, and 800 mm, and the measurement angle was changed to 0°, 90°, 180°, and 270° to measure the center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS). The measurement angle was an angle of 360° around the cylindrical coating layer surface. The measurement results are shown below.

Table 4 shows the measurement results after water blasting treatment, Table 5 shows the measurement results after belt polishing treatment, and Table 6 shows the measurement results after belt polishing treatment (low). As shown in Tables 4 to 6, when compared at the same measurement position and measurement angle, the experimental example using water blasting treatment had smaller center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS) than the experimental example using belt polishing treatment.

In addition, when considering the standard deviations of the center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS), the standard deviations of the experimental example using water blasting treatment were all smaller than those of the experimental example using belt polishing treatment. Combining Tables 1 and 4, it was found that in the experimental example using water blasting treatment, the standard deviation of the center line average roughness (Ra) could be set to about 0.1 μm to 0.5 μm, the standard deviation of the maximum height (Rz) could be set to about 1.5 μm to 3.5 μm, and the standard deviation of the point average roughness (RzJIS) could be set to about 0.5 μm to 2.0 μm. In this way, it was found that the variation in surface roughness can be reduced by performing water blasting treatment. From the above, it was found that the center line average roughness (Ra), maximum height (Rz), and ten-point average roughness (RzJIS) can be stably reduced by performing water blasting treatment.

All of the measurement results after the water blasting treatment described above correspond to the examples, and all of the measurement results after the belt polishing treatment correspond to the comparative examples.

<Experiment 3>
Next, the surface roughness was measured at three points of the tip, middle, and butt of the golf club shaft. The tip of the golf club shaft is near the head 30 shown in Fig. 1, the butt of the golf club shaft is near the grip 40 shown in Fig. 1, and the middle of the golf club shaft is the position between the tip and butt of the golf club shaft.

In the experiment, the surface of the paint layer formed on the outer peripheral surface of the fiber-reinforced resin layer was subjected to a water blasting treatment, and the surface roughness of the paint layer was measured. The measurement results are shown in Table 7 below.

Furthermore, in the experiment, the outer peripheral surface of the fiber-reinforced resin layer was subjected to belt polishing before the coating layer was formed, and the surface roughness of the outer peripheral surface of the fiber-reinforced resin layer was measured. The measurement results are shown in Table 8 below.

The Ra shown in Table 7 corresponds to the "center line average roughness Ra2 of the outer peripheral surface of the paint layer," and the Ra shown in Table 8 corresponds to the "center line average roughness Ra1 of the outer peripheral surface of the fiber-reinforced resin layer." As shown in Tables 7 and 8, it was found that Ra1>Ra2 at the tip, middle, and grip parts. The same results were also obtained for the maximum height (Rz) and the ten-point average roughness (RzJIS). Furthermore, the average spacing (Sm) of irregularities was larger on the water-blasted paint layer surface than on the outer peripheral surface of the fiber-reinforced resin layer at the tip, middle, and grip parts. Thus, it was found that the water-blasting treatment reduces irregularities and smooths the surface.

Furthermore, from Tables 7 and 8, it was found that the variation in Ra from the tip to the grip was smaller on the water-blasted paint layer surface than on the outer peripheral surface of the fiber-reinforced resin layer. It was found that the variation in Ra from the tip to the grip could be reduced to about 0.01 μm to 0.2 μm on the water-blasted paint layer surface. It was also found that the variation in Rz from the tip to the grip could be reduced to about 0.05 μm to 0.2 μm on the water-blasted paint layer surface. It was also found that the variation in Rz JIS from the tip to the grip could be reduced to about 0.05 μm to 0.2 μm on the water-blasted paint layer surface. It was also found that the variation in Ra from the tip to the grip was smaller on the water-blasted paint layer surface than on the example where the paint layer surface was subjected to belt polishing.

<Experiment 4>
Next, as an example, a topcoat was applied to the surface of the paint layer that had been subjected to water blasting. In this example, the relationship Ra1>Ra2 shown in Experiment 3 above was satisfied. In addition, as a comparative example, a topcoat was applied to the surface of the paint layer without subjecting it to water blasting.

In the experiment, cellophane tape was applied to the film surface of the Example and Comparative Example, then peeled off, and the peeled cellophane tape was applied to a backing paper. A photograph of this is shown in Figure 6, and a partial schematic diagram of Figure 6 is shown in Figure 7. The cellophane tape of the Comparative Example was applied to the backing paper on the left side shown in Figures 6 and 7, and the cellophane tape of the Example was applied to the backing paper on the right side shown in Figures 6 and 7. As shown in Figures 6 and 7, in the Comparative Example, part of the paint was attached to the cellophane tape, indicating poor adhesion. In contrast, in the Example, the paint was not attached to the cellophane tape, indicating good adhesion was maintained.

<Summary>
The above experiment has revealed that the adhesion of the paint can be improved by performing a water blasting treatment on the paint layer. It has also been found that in terms of adhesion, it is preferable that the center line average roughness Ra1 of the outer peripheral surface of the fiber reinforced resin layer and the center line average roughness Ra2 of the outer peripheral surface of the paint layer be Ra1>Ra2. Furthermore, although the size of the center line average roughness Ra2 is not specifically limited, it has been found from the above experiment results that it is preferable that it is 0.2 μm or more and 4.0 μm or less.

10 Golf club shaft (FRP member)
20 Golf club 30 Head 40 Grip 100 Fiber reinforced resin layer 200 Paint layer 300 Blasted layer 400 Paint layer 500 Blasted layer

Claims (3)

A fiber reinforced resin layer;
A coating layer located on the surface side of the fiber reinforced resin layer;
A blasted layer located on the surface side of the coating layer;
having
The coating layer is provided in a plurality of layers,
The blasted layer is provided on the surface side of the coating layers ,
An FRP member characterized in that a belt polishing layer is located on the surface side of the fiber reinforced resin layer, and a center line average roughness Ra1 of an outer peripheral surface of the fiber reinforced resin layer is larger than a center line average roughness Ra2 of an outer peripheral surface of the paint layer . The fiber reinforced resin layer is cylindrical,
The coating layer is cylindrical,
The blasted layer is cylindrical.
The FRP member according to claim 1 . The blasted layer is a water blasted layer.
3. The FRP member according to claim 1 or 2.