JP6972764B2 - Manufacturing method of glass fiber reinforced thermosetting resin molded body and glass fiber reinforced thermosetting resin molded body - Google Patents

Description

The present invention relates to a technique for manufacturing a glass fiber reinforced thermosetting resin molded body and a glass fiber reinforced thermosetting resin molded body.

Conventionally, FRP (Fiber Reinforced Plastic) made of a thermosetting resin reinforced with a plurality of glass single fibers has been widely used in various fields as a material having excellent mechanical properties and electrical insulation performance.
As a molding method of a molded product using FRP as a material (hereinafter, referred to as "glass fiber reinforced thermosetting resin molded body"), a pultrusion molding method, a filament winding method and the like are mainly known.

Specifically, in the method for forming a glass fiber-reinforced thermosetting resin molded body by a pultrusion method, first, the glass strand is formed from a roving winding body in which a glass strand formed by bundling a plurality of glass single fibers is twill-wound. Is drawn out and immersed in a tank filled with an uncured (liquid state) thermosetting resin while advancing in one direction. Then, by passing the glass strand (resin-impregnated glass strand) immersed in the thermosetting resin through the passage of the heated drawing mold, the thermosetting resin is heated while restricting the outer shape to the cross-sectional shape of the passage. It is cured and molded (see, for example, "Patent Document 1").
On the other hand, in the method for forming a glass fiber reinforced thermosetting resin molded body by the filament winding method, first, the glass strand is pulled out from the roving winding body and uncured while advancing in one direction, as in the above-mentioned drawing molding method. Immerse in a tank filled with thermosetting resin. Then, a glass strand (resin-impregnated glass strand) immersed in a thermosetting resin is wound around a tube-shaped mold while being wound, and then heat-cured to be removed from the mold (for example, "Patent Document 2". See).

Japanese Unexamined Patent Publication No. 2004-58613 Japanese Unexamined Patent Publication No. 2012-161960

By the way, the demand for property improvement required for the glass fiber reinforced thermosetting resin molded body molded by these molding methods has been increasing in recent years.
Here, for example, even if the fiber diameter of the glass single fiber constituting the glass strand is simply increased, it is contradictory to improve the bending strength and the bending elasticity of the glass fiber reinforced thermosetting resin molded body. It is difficult because it is a characteristic.
Further, if glass strands are present near the surface of the molded glass fiber reinforced thermosetting resin molded body, unevenness due to the glass single fiber is likely to occur on the surface. However, if the fiber diameter of the glass single fiber is increased, the number increases. Large irregularities are likely to occur.
As a result, in the glass fiber reinforced thermosetting resin molded body, which has a particularly high demand for design, for example, a glass chopped strand mat or glass paper impregnated with the thermosetting resin is impregnated with the glass fiber reinforced thermosetting resin. It is necessary to attach it to the surface of the molded body to improve the design separately, which may be a factor that causes an increase in manufacturing cost.

The present invention has been made in view of the current problems shown above, and is a glass fiber reinforced thermosetting resin having an excellent appearance while improving bending strength while ensuring an appropriate flexural modulus. An object of the present invention is to provide a molded body and a method for manufacturing the glass fiber reinforced thermosetting resin molded body.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem will be described.

That is, the glass fiber reinforced thermosetting resin molded body according to the present invention is a glass fiber reinforced thermosetting resin molded body including a thermosetting resin and a glass strand contained therein. The glass strand is composed of a plurality of glass single fibers, the average fiber diameter of the plurality of glass single fibers is 5 μm or more and 11 μm or less, and the number of the plurality of glass single fibers is 4000 or more and 10,000 or less. It is characterized by being.

According to the present invention having such a configuration, the average fiber diameter of the glass single fiber is smaller and the number of bundled fibers is larger than that of the conventional glass strand having the same count, for example, so that the surface area of the entire glass strand ( The outer peripheral surface) increases, and the area that can be bound to the thermosetting resin increases.
As a result, it is possible to improve the bending strength while ensuring an appropriate flexural modulus.
Further, according to the present invention, the fiber diameter of the glass single fiber appearing on the surface of the glass strand is smaller than that of the conventional one having the same count, for example. Roughness is unlikely to occur on the surface, and the appearance of the glass fiber reinforced thermosetting resin molded body can be improved.

Further, the glass fiber reinforced thermosetting resin molded product according to the present invention may be provided with a plurality of the glass strands.

According to the present invention having such a structure, it is possible to provide a glass fiber reinforced thermosetting resin molded product having higher bending strength.

Further, in the method for producing a glass fiber reinforced thermosetting resin molded body according to the present invention, a glass strand formed by bundling a plurality of glass single fibers is impregnated with an uncured (liquid state) thermosetting resin. Manufacture of a glass fiber reinforced thermosetting resin molded body comprising an impregnating step of forming a resin-impregnated glass strand and a heating step of heating and curing the resin-impregnated glass strand to obtain a glass fiber reinforced thermosetting resin molded body. The method is characterized in that the average fiber diameter of the plurality of glass single fibers is 5 μm or more and 11 μm or less, and the number of the plurality of glass single fibers is 4000 or more and 10,000 or less.

According to the present invention having such a configuration, the average fiber diameter of the glass single fiber is smaller and the number of bundled pieces is larger than that of the conventional glass strand (resin-impregnated glass strand) having the same count, for example. The surface area (outer peripheral surface) of the entire glass strand is increased, and the area that can be bonded to the thermosetting resin is increased.
As a result, it is possible to improve the bending strength while ensuring an appropriate flexural modulus.
Further, according to the present invention, the fiber diameter of the glass single fiber appearing on the surface of the glass strand (resin-impregnated glass strand) is smaller than that of the conventional one having the same count, for example. Roughness is unlikely to occur on the surface of the curable resin molded body, and the appearance of the glass fiber reinforced thermosetting resin molded body can be improved.

Further, in the method for producing a glass fiber reinforced thermosetting resin molded body according to the present invention, the resin-impregnated glass strand may include a plurality of the glass strands.

According to the present invention having such a structure, it is possible to provide a glass fiber reinforced thermosetting resin molded product having higher bending strength.

Further, in the method for producing a glass fiber reinforced thermosetting resin molded body according to the present invention, the resin-impregnated glass strands include a first glass strand having an average fiber diameter of the glass single fiber of R1 and the glass single fiber. The second glass strand, which has an average fiber diameter of R2 having an average fiber diameter smaller than the average fiber diameter R1 of the glass single fibers constituting the first glass strand, is provided. It is preferable to heat-cure the second glass strand made of a glass single fiber having a small fiber diameter in a state where the second glass strand is arranged on the surface.

According to the present invention having such a configuration, since the glass strand having a small average fiber diameter is arranged on the surface, the unevenness that may occur on the surface of the molded glass fiber reinforced thermosetting resin molded body is more effective. Can be suppressed.
In addition, since the parts other than the surface are composed of glass strands having a larger fiber diameter than the glass strands arranged on the surface, it is possible to improve the bending strength while ensuring an appropriate flexural modulus. That is, since the average fiber diameters of the glass strands arranged on the surface and the glass strands other than the surface are different, it is possible to achieve both the appearance, the flexural modulus, and the bending strength.

Further, in the method for producing a glass fiber reinforced thermosetting resin molded product according to the present invention, the glass fiber reinforced thermosetting resin molded product is molded by either a pultrusion molding method or a filament winding method. It is a feature.

That is, the pultrusion molding method and the filament winding method are molding methods that can most effectively utilize the mechanical properties of the glass strands provided as reinforcing fibers among various molding methods related to FRP, and have a high glass content. It is known as a molding method for obtaining a resin molded body having the highest mechanical strength. Even when such a molding method is used, a sufficient effect can be obtained according to the present invention.

As the effect of the present invention, the following effects are exhibited.
That is, according to the glass fiber reinforced thermosetting resin molded body and the method for manufacturing the glass fiber reinforced thermosetting resin molded body according to the present invention, the bending strength is improved while ensuring an appropriate bending elasticity. It is possible to provide a glass fiber reinforced thermosetting resin molded body having excellent appearance, and a method for producing the glass fiber reinforced thermosetting resin molded body.

It is sectional drawing which showed the cross-sectional shape of the glass fiber reinforced thermosetting resin molded body in one Embodiment of this invention. It is a figure which showed the manufacturing process of the glass fiber reinforced thermosetting resin molded body in one Embodiment of this invention, and is the process drawing which showed the manufacturing process by the drawing molding method. It is a figure which showed the manufacturing process of the glass fiber reinforced thermosetting resin molded article in another embodiment of this invention, and used the roving winding | winding body of a plurality of kinds of different fiber diameters of a glass single fiber by a filament winding molding method. It is a process diagram which showed the manufacturing process in the case of manufacturing. It is a figure which showed the test method of even, (a) is a schematic diagram which showed the state immediately after setting the glass strand which becomes a test piece in the even test apparatus, (b) is the glass strand which becomes a test piece. It is a schematic diagram which showed the state in which a plurality of glass single fibers were hung down by defibrating.

Next, a mode for carrying out the present invention will be described with reference to FIGS. 1 to 4.
For the sake of convenience, the following description will be described by defining the vertical direction and the horizontal direction of the even test apparatus 100 by the direction of the arrow shown in FIG.

[Structure of glass fiber reinforced thermosetting resin molded body 1]
First, the configuration of the glass fiber reinforced thermosetting resin molded body 1 (hereinafter, simply referred to as “resin molded body 1”) that embodies the present invention will be described with reference to FIGS. 1 and 4.
In the following description, the resin molded body 1 having a solid round bar shape is mainly described, but the shape of the resin molded body 1 is not limited to this, and for example, other solid bodies may be described. Any shape may be used, such as a cross-sectional shape (for example, a flat plate member), a hollow tube shape, or a tubular shape having a bottom.

The resin molded body 1 in the present embodiment is a molded product made of FRP as a material, and as shown in FIG. 1, mainly a thermosetting resin 2 and a glass strand contained in the thermosetting resin 2. 3 and.
In other words, the thermosetting resin 2 exists not only on the surface of the glass strand 3 but also in a state of being filled at intervals thereof.

The type of the thermosetting resin 2 is not particularly limited, and examples thereof include an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, a phenol resin, and a melamine resin. It is appropriately selected according to the intended use.

The glass strand 3 is composed of a plurality of focused glass single fibers 3a, 3a ..., And is a reinforcing fiber for strengthening the mechanical properties (for example, bending strength, bending elastic modulus, etc.) of the thermosetting resin 2. It is inherent in the resin molded body 1.
Here, as the glass constituting the glass single fiber 3a, any kind such as E glass, AR glass, C glass, D glass, and S glass may be used.
However, E-glass is preferable because it is inexpensive and it is easy to obtain a resin molded body 1 having relatively excellent mechanical strength. Further, S glass is preferable because it is easy to obtain a resin molded body 1 having further excellent mechanical strength as compared with E glass.

As will be described later, the glass single fiber 3a is formed by continuously drawing out the molten glass material from the nozzle 10a of the bushing 10 (see FIG. 2) and forming it into a fiber shape, and the average fiber diameter thereof is It is set to 5 μm or more and 11 μm or less.
Further, the number of the plurality of glass single fibers 3a, 3a ... Consisting of the glass strand 3 is set to 4000 or more and 10000 or less.

Here, when the average fiber diameter of the glass single fiber 3a is less than 5 μm, it is difficult to stably form the glass single fiber 3a. Further, when the average fiber diameter of the glass single fiber 3a is less than 5 μm, the glass single fiber 3a is easily broken and it is difficult to improve the bending strength.
Further, when the average fiber diameter of the glass single fiber 3a exceeds 11 μm, the presence of the glass single fiber 3a in the vicinity of the surface of the resin molded body 1 after molding tends to cause unevenness due to the glass single fiber 3a on the surface. , The appearance of the resin molded body 1 is deteriorated. Further, when the average fiber diameter of the glass single fiber 3a exceeds 11 μm, the flexural modulus of the resin molded body 1 decreases.

On the other hand, when the number of focused glass single fibers 3a, 3a ... Is less than 4000, it is possible to improve the bending strength while ensuring an appropriate bending elastic modulus due to the insufficient number of glass single fibers 3a. Have difficulty. Further, when the number of the glass single fibers 3a, 3a ... To be focused exceeds 10,000, the bushing 10 (see FIG. 2) used for spinning the glass single fibers 3a becomes a large scale, and the equipment becomes large. It is not desirable because of the high cost.

Therefore, in the present embodiment, the average fiber diameter of the plurality of glass single fibers 3a, 3a ... Constituting the glass strand 3 is set to 5 μm or more and 11 μm or less, and the plurality of glass single fibers to be focused are set. The number of fibers 3a, 3a ... Is set to 4000 or more and 10000 or less.
As a result, the average fiber diameter of the glass single fibers 3a becomes smaller and the number of bundled fibers increases as compared with the case where, for example, conventional glass strands having the same count are used. The surface area (outer peripheral surface) of the glass increases, and the area that can be bonded to the thermosetting resin 2 increases.
As a result, it is possible to improve the bending strength while ensuring an appropriate flexural modulus.

Further, according to the present embodiment, the average fiber diameter of the glass single fiber 3a appearing on the surface of the glass strand 3 is smaller than that of the conventional one having the same count, for example, so that the surface of the molded resin molded body 1 is formed. It is possible to improve the appearance of the resin molded body 1 because unevenness is unlikely to occur on the top.

For the plurality of glass single fibers 3a, 3a ..., It is preferable that the average fiber diameter is 7 μm or more and 9 μm or less, and the number of fibers is 5000 or more and 7,000 or less.
More specifically, for the plurality of glass single fibers 3a, 3a ..., It is more preferable that the average fiber diameter is 7 μm or more and 8 μm or less, and the number of fibers is 5500 or more and 6500 or less.

By the way, as the glass strand 3 used in the resin molded body 1, it is preferable that the glass single fiber 3a shows a value of 40 mm or less in the even test.

Here, the even test method will be described with reference to FIG.
First, the glass strand 3 to be tested is cut to a length of about 2.0 m to 2.2 m and set in the even test apparatus 100.

Specifically, as shown in FIG. 4A, the even test apparatus 100 has an interval of 2 m (dimension D in FIG. 4A) in the horizontal direction (left and right in the present embodiment). A pair of support members 101 and 102 facing each other in the direction) are provided, and the glass strand 3 is horizontally supported by supporting both ends of the cut glass strand 3 by these support members 101 and 102, respectively. Hold in a state of extending in the direction.
When both ends of the glass strand 3 are supported by the support members 101 and 102, they are firmly fixed to each other by using, for example, an adhesive.

Next, as shown in FIG. 4B, the glass strands 3 held by the support members 101 and 102 are defibrated (monofilamentized) to expose the glass single fibers 3a, 3a, etc. for each fiber. After that, the horizontal of the glass single fiber 3a is based on a virtual straight line (straight line La in FIG. 4B) connecting the positions where both ends of the glass strand 3 in the pair of support members 101 and 102 are fixed to each other. Measure the amount of sagging in the center of the direction.

Specifically, the glass strand 3 held by the support members 101 and 102 is kneaded as a whole by, for example, manually, and after confirming that the glass strand 3 is completely unraveled by visual inspection, the first glass single fiber 3a is used. Measure the amount of sagging.

Here, the "hanging amount" means the amount of displacement of the glass single fiber 3a in the central portion in the horizontal direction in the vertical direction (downward in the present embodiment) orthogonal to the horizontal direction.
Further, the horizontal central portion of the glass single fiber 3a corresponds to the horizontal central portion between the pair of support members 101 and 102, and the amount of hanging of the glass single fiber 3a becomes the maximum value in this portion.
The amount of hanging of the glass single fiber 3a is defined by the amount of hanging of the glass single fiber 3a having the largest displacement among the plurality of existing glass single fibers 3a, 3a ...

After the first measurement is completed, the glass strand 3 is manually kneaded again, and after confirming that the glass strand 3 is completely solved by visual inspection, the amount of drooping of the second glass single fiber 3a is measured.
Then, the first measured value and the second measured value are compared, and if both measured values are the same, the measured value is used as the drooping amount of the glass single fiber 3a (dimension X in FIG. 4 (b)). ).

On the other hand, as a result of comparing the first measurement value and the second measurement value, if the two measurement values are different, the glass strand 3 was manually kneaded again and it was confirmed that the glass strand 3 was completely solved visually. Then, the amount of drooping of the glass single fiber 3a is measured for the third time.
In this way, a series of operations are repeated until the measured value of the drooping amount becomes the same value as the previous measured value, and the last measured drooping amount is determined as the drooping amount (dimension X) of the glass single fiber 3a. do.

In the even test performed by the above procedure, as described above, it is preferable for the resin molded body 1 to use the glass strand 3 composed of the glass single fiber 3a having a drooping amount of 40 mm or less.
Specifically, it is more preferable for the resin molded body 1 to use the glass strand 3 made of the glass single fiber 3a having a drooping amount of 20 mm or more and 35 mm or less.

In such a case where the amount of hanging of the glass single fiber 3a is 40 mm or less, the lengths of the respective glass single fibers 3a, 3a ... When the resin molded body 1 is manufactured, the disconnection of the glass strand 3 can be suppressed more effectively.

[Manufacturing method of glass fiber reinforced thermosetting resin molded body (resin molded body) 1]
Next, a method for manufacturing the glass fiber reinforced thermosetting resin molded body 1 (resin molded body 1) in the present embodiment will be described with reference to FIG.

First, in the previous step, the molten glass material (molten glass) is continuously drawn out through a plurality of (4000 to 10000) nozzles 10a, 10a ... Provided at the bottom of the platinum bushing 10. Then, a plurality of fibrous single glass fibers 3a, 3a ... With an average fiber diameter of 5 μm or more and 11 μm or less are formed.
The plurality of molded glass single fibers 3a, 3a ... Are subsequently applied with a sizing agent and are focused on one glass strand 3 via a sizing roller 11.

Then, the plurality of focused glass single fibers 3a, 3a ... (Glass strand 3) are wound into a roll shape by a collet or the like (not shown), whereby the roving winding body 4 is formed.

The formed roving winding body 4 is sent to the molding step S100, which is the next step.
The molding step S100 is a manufacturing step using a pultrusion molding method, and is mainly composed of an impregnation step S101, a heating step S102, a cutting step S103, and the like, which are arranged in order over time.

A drawing device 40 is disposed between the heating step S102 and the cutting step S103, and as will be described later, the resin molded body 1 heat-cured by the drawing device 40 is pulled out to perform roving winding. The glass strand 3 is drawn out from the rotating body 4, and then the glass strand 3 is conveyed in the order of the resin accommodating tank 20, the drawing die 30, the drawing device 40, and the cutting device 50, and the resin molded product as a final product. 1A is formed.

In addition, in the case of molding a resin molded body (not shown) having, for example, a tube shape or a tubular shape instead of a solid shape such as the resin molded body 1 of the present embodiment, it will be described later. It will be molded by the molding step S200 using a flexible filament winding method.

In the impregnation step S101, one glass strand 3 formed by focusing 4000 to 10000 glass single fibers 3a, 3a ... With a plurality of continuous average fiber diameters of 5 μm or more and 11 μm or less is uncured (liquid). This is a step of impregnating the thermosetting resin 2 (hereinafter referred to as “thermosetting resin 2A”) in the state) to form the resin-impregnated glass strand 5.
The impregnation step S101 is provided with a resin storage tank 20 in which the uncured thermosetting resin 2A is stored.

The thermosetting resin 2A stored in the resin storage tank 20 may contain a curing agent, a mold release agent, or the like, and may contain a curing accelerator, a reactive diluent, a colorant, a filler, and an increase. A slimming agent, a low shrinkage agent and the like may be contained.

Then, the roving winding body 4 sent to the molding step S100 is first unwound in the impregnation step S101, and one continuous glass strand 3 is drawn out from the roving winding body 4.
The glass strand 3 drawn out from the roving winding body 4 is guided into the resin storage tank 20 and immersed while passing through the uncured thermosetting resin 2A, and then again to the outside of the resin storage tank 20. Is withdrawn.
As a result, the glass strand 3 is impregnated with the uncured thermosetting resin 2A, and the resin-impregnated glass strand 5 is formed.

The resin-impregnated glass strand 5 drawn out of the resin storage tank 20 is subsequently led to the heating step S102.
The heating step S102 is a step of heating and curing the resin-impregnated glass strand 5 to obtain the resin molded body 1.
In the heating step S102, a drawing die 30 having a through passage 30a is provided.

The drawing die 30 is provided with a heating heater (not shown), and the drawing die 30 is always maintained at a predetermined heating temperature by the heating heater.
Further, the cross-sectional shape of the through passage 30a is set based on the shape of the resin molded body 1 finally obtained, and is set to a circular shape, for example, in the present embodiment.
A release agent such as liquid paraffin, solvent-based wax, silicone resin, or polyvinyl alcohol solution may be applied to the inner peripheral surface of the through passage 30a.

Here, as described above, a drawing device 40 is arranged between the heating step S102 and the cutting step S103, and the drawing device 40 is, for example, a pair of endless shapes arranged so as to face each other in the vertical direction. It is composed of conveyors 41 and 41 and the like.

Then, the resin-impregnated glass strand 5 drawn out from the resin storage tank 20 is pulled out by the drawing device 40 in a state of being sandwiched between the pair of endless conveyors 41 and 41, and is guided to the drawing die 30. After passing through the through passage 30a, it is pulled out to the outside of the drawing die 30 again.
As a result, the resin-impregnated glass strand 5 is heat-cured while the outer shape of the resin-impregnated glass strand 5 is restricted by the cross-sectional shape of the through passage 30a, and a continuous resin molded body 1 is formed.

The resin molded body 1 drawn out of the drawing die 30 is subsequently guided to the cutting step S103.
The cutting step S103 is a step of cutting the molded resin molded body 1 to a predetermined length as a final product.
In the cutting step S103, for example, a cutting device 50 including a disk-shaped blade 51 and a drive motor 52 for rotationally driving the blade 51 around an axis is provided.

Then, the resin molded body 1 drawn out from the drawing die 30 and passing through the drawing device 40 is cut at a predetermined position by the blade 51 of the cutting device 50 rotating at high speed.
As a result, a long resin molded body 1A having a predetermined length, which is a final product, is obtained, and the molding step S100 is completed.

[Structure of glass fiber reinforced thermosetting resin molded body 201 in another embodiment]
Next, the configuration of the glass fiber reinforced thermosetting resin molded body (hereinafter, simply referred to as “resin molded body 201”) in another embodiment will be described with reference to FIG.
While the resin molded body 201 in another embodiment has a structure partially equivalent to that of the resin molded body 1 described above, the structure of the glass strand 203 is significantly different from that of the resin molded body 1.
Therefore, in the following description, the differences from the resin molded body 1 will be mainly described, and the description of the configuration equivalent to the resin molded body 1 will be omitted.

In the following description, the resin molded body 201 having a hollow tube shape is mainly described, but the shape of the resin molded body 201 is not limited to this, and for example, a solid round bar shape is described. It may have any shape, such as one having a cylindrical shape or one having a bottom.

The resin molded body 201 mainly includes a thermosetting resin 202 of a matrix resin (resin base material) and a plurality of glass strands 203 contained in the thermosetting resin 202.
Here, the plurality of glass strands 203 used are composed of a plurality of types of glass strands having different average fiber diameters of single glass fibers. For example, in the present embodiment, the first glass strand 203A having an average fiber diameter of R1. And two types of glass strands 203A and 203B, which are the second glass strand 203B made of a glass single fiber having an average fiber diameter R2 having at least an average fiber diameter smaller than that of the glass single fiber constituting the first glass strand 203A. It is composed of.

In these plurality of types (two types in the present embodiment) of the glass strands 203 and 203, the first glass strand 203A made of a glass single fiber having a large average fiber diameter is arranged on the center side in the cross-sectional view of the resin molded body 201. In addition, the second glass strand 203B made of a glass single fiber having a small average fiber diameter is contained in the resin molded body 201 by arranging the second glass strand 203B on the outside of the first glass strand 203A, that is, on the surface of the resin molded body 201. Will be done.

By having such a configuration, since the glass strand having a small average fiber diameter is arranged on the surface, it is possible to more effectively suppress the unevenness that may occur on the surface of the resin molded body 201 to be molded.
In addition, since the parts other than the surface are composed of glass strands having a larger fiber diameter than the glass strands arranged on the surface, it is possible to improve the bending strength while ensuring an appropriate flexural modulus. That is, since the average fiber diameters of the glass strands arranged on the surface and the glass strands other than the surface are different, it is possible to achieve both the appearance, the flexural modulus, and the bending strength.

In the present embodiment, two types of glass strands 203A and 203B having different average fiber diameters of glass single fibers are used, but the present invention is not limited to this, and for example, not only the average fiber diameter but also the average fiber diameter is used. The number of fibers to be focused may also be different.
Further, as long as the glass strand 203 made of the glass single fiber having the largest average fiber diameter is not arranged on the surface of the resin molded body 201, the type of the glass strand 203 may be three or more.
Specifically, for example, when three different types of glass strands having an average fiber diameter are used, the glass strand made of the glass single fiber having the smallest average fiber diameter is arranged on the surface of the resin molded body.

However, it goes without saying that in all the glass strands 203A and 203B, the average fiber diameter of the glass single fibers is 5 μm or more and 11 μm or less, and the number of glass single fibers is 4000 or more and 10,000 or less.

[Method for manufacturing glass fiber reinforced thermosetting resin molded product (resin molded product) 201 in another embodiment]
Next, a method for manufacturing the glass fiber reinforced thermosetting resin molded body (resin molded body) 201 according to another embodiment will be described with reference to FIG.
First, similarly to the method for manufacturing the resin molded body 1 described above, in the previous step, a plurality of glass single fibers 203a / 203a ... The roving winding body 204 is formed by focusing on one glass strand 203 by the focusing roller 211 and then winding it into a roll shape by a collet or the like (not shown).

Here, in the present embodiment, a plurality of types (two types in this embodiment) of glass strands 203 having different average fiber diameters of the glass single fibers 203a, that is, the first glass strand 203A and the second glass strand 203B are used. Be done.
Therefore, in the previous step, the first roving winding body 204A in which the first glass strand 203A is wound and the second roving winding body 204B in which the second glass strand 203B is wound are formed. NS.

These two types of roving winding bodies 204A and 204B formed are sent to the molding step S200, which is the next step.
The molding step S200 is a manufacturing step using a filament winding method, and is mainly composed of an impregnation step S201, a winding step S202, a heating step S203, a demolding step S204, and the like, which are arranged in order over time.

Then, as will be described later, in the winding step S202, the resin-impregnated glass strand 205 is wound around the mandrel 231 to pull out the glass strand 203 from the roving winding body 204, and then the resin accommodating tank 220 and the winding device. The glass strand 203 is conveyed in the order of 230, and the resin molded body 201A as a final product is formed.

In addition, in the case of molding a resin molded body (not shown) having, for example, a solid round bar shape instead of the hollow tube-shaped one such as the resin molded body 201 of the present embodiment, the above-mentioned is described. It will be molded by the molding step S100 using such a pultrusion molding method.

The impregnation step S201 is a step having substantially the same contents as the impregnation step S101 of the molding step S100 described above, while the two types of roving winding bodies 204 (first roving winding body 204A and second roving winding body 204B). ) Is used, which is different from the impregnation step S101.
Therefore, in the following description, the differences from the impregnation step S101 will be mainly described, and the description of the contents equivalent to the impregnation step S101 will be omitted.

The two types of the first roving winding body 204A and the second roving winding body 204B sent to the molding step S200 are first unwound in the impregnation step S201, respectively, and these first roving winding body 204A and the second roving are used. One continuous glass strand 203 (first glass strand 203A and second glass strand 203B) is pulled out from the winding body 204B, respectively.

The end portion (end portion on the drawing direction side) of the second glass strand 203B made of a glass single fiber having a small average fiber diameter drawn from the second roving winding body 204B is in the first roving winding body 204A. It is connected to the start end portion (the end portion opposite to the end portion) of the first glass strand 203A which is still in the wound state.
After that, the first glass strand 203A drawn out from the first roving winding body 204A is guided into the resin accommodating tank 220.

The first glass strand 203A guided into the resin storage tank 220 is immersed while passing through the uncured thermosetting resin 202 (hereinafter referred to as “thermosetting resin 202A”), and then the resin is again immersed. It is pulled out to the outside of the containment tank 220.
As a result, the first glass strand 203A is impregnated with the uncured thermosetting resin 202A, and the resin-impregnated glass strand 205 is formed.

When the molding of the resin molded body 201 progresses and the start end portion of the first glass strand 203A is guided into the resin storage tank 220, the resin molded body 201 is guided into the resin storage tank 220 with the end portion of the second glass strand 203B. Be taken.
As a result, the second glass strand 203B is continuously immersed while passing through the uncured thermosetting resin 202A, and the second glass strand 203B is impregnated with the thermosetting resin 202A to cause the resin. The impregnated glass strand 205 is continuously formed.

The resin-impregnated glass strand 205 drawn out of the resin storage tank 220 is subsequently led to the winding step S202.
The winding step S202 is a step of continuously winding the resin-impregnated glass strand 205 to form a hollow tube shape.
In the winding step S202, for example, a winding device 230 including a columnar mandrel 231 and a drive motor 232 for rotationally driving the mandrel 231 around an axial center is provided.

Then, the resin-impregnated glass strand 205 drawn out from the resin storage tank 220 is wound while applying a predetermined tension to the rotated mandrel 231 while vibrating.
As a result, the resin-impregnated glass strand 205 is formed in the shape of a hollow tube.

As described above, the first glass strand 203A and the second glass strand 203B constituting the resin-impregnated glass strand 205 are connected to each other, and when the resin-impregnated glass strand 205 is wound around the mandrel 231. First, the first glass strand 203A is wound, and then the second glass strand 203B is wound around the upper layer portion of the wound first glass strand 203A.
As a result, in the resin-impregnated glass strand 205 formed in the shape of a hollow tube, the second glass strand 203B made of glass single fiber 203a having a smaller average fiber diameter than the first glass strand 203A is always arranged on the surface. It will be in the state of being.

When the winding of the resin-impregnated glass strand 205 around the mandrel 231 is completed, the heating step S203 is started.
The heating step S203 is a step of heating and curing the resin-impregnated glass strand 205 to obtain the resin molded body 1.
Here, the winding device 230 is provided with a heating heater (not shown), and the mandrel 231 is configured to be heated to a predetermined heating temperature by the heating heater.

Then, the temperature of the mandrel 231 is raised depending on the state in which the resin-impregnated glass strand 205 is wound.
As a result, the resin-impregnated glass strand 205 is heat-cured in a state where the second glass strand 203B made of a glass single fiber 203a having a smaller fiber diameter than the first glass strand 203A is always arranged on the surface. Then, a hollow tube-shaped resin molded body 201 is molded.

When the uncured thermosetting resin 202A impregnated in the resin-impregnated glass strand 205 reaches a sufficient hardness and the heating step S203 is completed, the demolding step S204 is started.
The demolding step S204 is a step of taking out the molded resin molded body 201 from the winding device 230.

The molded resin molded body 201 that has been molded is taken out from the mandrel 231 and taken out from the winding device 230.
As a result, a hollow tube-shaped resin molded body 201A, which is the final product, is obtained, and the molding step S200 is completed.

[Overview of manufacturing method]
As described above, the resin molded bodies 1 and 201 in the present embodiment are mainly molded by either a pultrusion molding method or a filament winding method.
That is, the round bar-shaped resin molded body 1 as described above is mainly molded by the pultrusion method, and for example, the resin molded body 201 of another embodiment having a tube shape is mainly molded by the filament winding method. Will be done.

Such a molding method by a pultrusion molding method and a filament winding method is a molding method that can most effectively utilize the mechanical properties of the glass strands 3 and 203 provided as reinforcing fibers among various molding methods related to FRP. It is known as a molding method for obtaining resin molded bodies 1.201 having a high glass content and the highest mechanical strength.
Further, in these molding methods, mechanization in each manufacturing process is progressing, and not only mass production and automation are possible, but also the quality of the molded resin molded body 1 is relatively stable. be.

By the way, in order to judge the effectiveness of the glass fiber reinforced thermosetting resin molded product (resin molded product) 1.201 that embodies the present invention, the following experiments were conducted.

First, as a sample of the embodiment of the present invention molded by the pultrusion molding method, a round bar-shaped resin molded body according to Examples 1 and 2 was prepared. Further, as a comparison target of these samples, a round bar-shaped resin molded product according to Comparative Examples 1, 2 and 3 was prepared.

Here, both of these samples (Examples 1 and 2 and Comparative Examples 1, 2, and 3) were experimentally produced in the laboratory according to the procedure shown below.
That is, various glass strands having different average fiber diameters and number of focused glass strands are prepared, and 2% by mass of the radical initiator Percadox C-50L (manufactured by Chemical Axo) is dissolved in these glass strands. After impregnating each of the unsaturated polyester resin N-350L (manufactured by Japan Composite), which is a thermosetting resin, the glass strand impregnated with the thermosetting resin is placed in a glass tube having a diameter of 2.3 mm and a length of 50 cm. bottom.

Next, in this state, the glass strand is heated at 80 ° C. for 1 hour, then heated at 120 ° C. for 1 hour, cooled, and the glass strand is taken out (demolded) from the inside of the glass tube to have a diameter of 2. A sample having a round bar shape of 15 mm was obtained.

For Examples 1 and 2, a sample was formed using a glass strand made of a plurality of glass single fibers having an average fiber diameter of 7.0 μm and a number of focused fibers of 6000.
The glass strand used in Example 1 has a count of 600 tex and the amount of fibers in the sample is 79.3 wt%, and the glass strand used in Example 2 has a count of 600 tex and the sample. The amount of fiber in the glass is 65.7 wt%.

On the other hand, in Comparative Examples 1 and 3, a sample was formed by molding a sample using a glass strand made of a plurality of glass single fibers having an average fiber diameter of 17.0 μm and a number of focused fibers of 2000. For Example 2, it was decided to form a sample using a glass strand made of a plurality of glass single fibers having an average fiber diameter of 13.0 μm and a number of focused fibers of 2000.
Further, the glass strand used in Comparative Example 1 has a count of 1200 tex and the amount of fibers in the sample is 79.5 wt%, and the glass strand used in Comparative Example 2 has a count of 700 tex and the sample. The amount of fiber in the sample is 79.7 wt%, the glass strand used in Comparative Example 3 has a count of 1200 tex, and the amount of fiber in the sample is 65.42 wt%.

For various samples manufactured according to the above procedure, the appearance of the glass grain (pattern by the glass single fiber exposed on the surface) on the surface is evaluated as an appearance judgment, and the maximum bending strength and bending which are mechanical characteristics are evaluated. The elastic modulus was measured respectively.

The evaluation of the glass grain shall be performed visually, and if the glass grain is almost invisible, it is judged to be good (marked with a circle), and if the glass grain is slightly visible, it is normal (marked with a △ mark). ), And if the glass grain is clearly visible, it is judged to be defective (marked with a cross).

The maximum bending strength and flexural modulus will be measured by a three-point bending test. As the test conditions at that time, the distance between the fulcrums is set to 32 mm and the test speed is set to 1.3 mm / min. I decided to set it.

The results thus obtained are shown in [Table 1].

As shown in [Table 1], the results of the samples in Examples 1 and 2 having good appearance (marked with ◯) could be obtained.
On the other hand, the sample in Comparative Example 2 had a normal appearance (marked with Δ), but the samples in Comparative Examples 1 and 3 both had a poor appearance (marked with ×). ..

Further, the samples in Examples 1 and 2 both exceeded 45.0 GPa and recorded the maximum bending strength exceeding 1100 MPa, whereas the samples in Comparative Examples 1, 2 and 3 both exceeded 45.0 GPa. However, it did not exceed 1100 MPa.

Based on the results of the above verification experiments, a plurality of single glass fibers having an average fiber diameter of 5 μm or more and 11 μm or less and a focused number of 4000 or more and 10,000 or less as shown in the resin molded body 1 of the present embodiment. It can be confirmed that a resin molded product using a glass strand made of the above can be used to improve the bending strength while ensuring an appropriate flexural modulus and to obtain a resin molded product having excellent appearance. rice field.

Next, as a sample of the embodiment of the present invention molded by the filament winding method, a hollow tube-shaped resin molded body according to Example 3 was prepared. Further, as a comparison target of this sample, a hollow tube-shaped resin molded body according to Comparative Example 4 was prepared.

At this time, the thermosetting resin used is obtained by dissolving 2% by mass of the radical initiator Percadox C-50L (manufactured by Chemical Axo) in the same manner as in the verification experiment of the resin molded body molded by the above-mentioned pultrusion molding method. It was decided to use the unsaturated polyester resin N-350L (manufactured by Japan Composite).
Further, the outer diameter of the sample to be molded is set so that the inner diameter is 50 mm and the outer diameter is 60 mm.

In Example 3, a sample was formed using a glass strand made of a plurality of glass single fibers having an average fiber diameter of 7.0 μm and a number of focused fibers of 6000.
On the other hand, in Comparative Example 4, it was decided to form a sample using a glass strand made of a plurality of glass single fibers having an average fiber diameter of 17.0 μm and a number of focused fibers of 2000.

For various samples produced according to the above procedure, it was decided to evaluate the appearance of the glass grain (pattern by the glass single fiber exposed on the surface) on the surface as an appearance judgment.

The evaluation of the glass grain shall be performed visually as in the verification experiment of the resin molded body molded by the above-mentioned drawing molding method, and if the glass grain is almost invisible, it is considered good (marked with a circle). Judgment was made, and if the glass grain was slightly visible, it was judged to be normal (indicated by a Δ mark), and if the glass grain was clearly visible, it was judged to be defective (indicated by a cross mark).

The results thus obtained are shown in [Table 2].

As shown in [Table 2], the sample in Example 3 had a good appearance (marked with ◯).
On the other hand, the sample in Comparative Example 4 was found to have a poor appearance (marked with x).

Based on the results of the above verification experiments, a plurality of single glass fibers having an average fiber diameter of 5 μm or more and 11 μm or less and a focused number of 4000 or more and 10,000 or less as shown in the resin molded body 2 of the present embodiment. It was confirmed that a resin molded product having an excellent appearance can be obtained if it is a resin molded product using a glass strand made of the above.

1 Glass fiber reinforced thermosetting resin molded body (resin molded body)
2 Thermosetting resin 2A Thermosetting resin (uncured)
3 Glass strand 3a Glass single fiber 5 Resin impregnated glass strand 201 Glass fiber reinforced thermosetting resin molded body (resin molded body)
202 Thermosetting resin 202A Thermosetting resin (uncured)
203 Glass Strand 203A First Glass Strand 203B Second Glass Strand 203a Glass Single Fiber 205 Resin Impregnated Glass Strand S101 Impregnation Step S102 Heating Step S201 Impregnation Step S203 Heating Step

Claims (6)

Thermosetting resin and
The glass strands contained in the thermosetting resin and
It is a glass fiber reinforced thermosetting resin molded body provided with
The glass strand consists of a plurality of single glass fibers.
The average fiber diameter of the plurality of glass single fibers is 5 μm or more and 7 μm or less, and the number of the plurality of glass single fibers is 4000 or more and 10,000 or less.
A glass fiber reinforced thermosetting resin molded product. It is provided with a plurality of the glass strands.
The glass fiber reinforced thermosetting resin molded product according to claim 1. An impregnation step of impregnating an uncured thermosetting resin with a glass strand formed by bundling a plurality of glass single fibers to form a resin-impregnated glass strand.
A heating step of heating and curing the resin-impregnated glass strand to obtain a glass fiber-reinforced thermosetting resin molded body,
A method for manufacturing a glass fiber reinforced thermosetting resin molded product.
The average fiber diameter of the plurality of glass single fibers is 5 μm or more and 7 μm or less, and the number of the plurality of glass single fibers is 4000 or more and 10,000 or less.
A method for producing a glass fiber reinforced thermosetting resin molded product. The resin-impregnated glass strand comprises a plurality of the glass strands.
The method for producing a glass fiber reinforced thermosetting resin molded product according to claim 3. The resin-impregnated glass strand is
The first glass strand having an average fiber diameter of R1 and the glass single fiber
A second glass strand in which the average fiber diameter of the glass single fiber is R2 having an average fiber diameter smaller than the average fiber diameter R1 of the glass single fiber constituting the first glass strand.
Be prepared for
In the heating step,
The second glass strand is heat-cured with the second glass strand placed on the surface.
The method for producing a glass fiber reinforced thermosetting resin molded product according to claim 4. The glass fiber reinforced thermosetting resin molded body is molded by either a pultrusion molding method or a filament winding method.
The method for producing a glass fiber reinforced thermosetting resin molded product according to any one of claims 3 to 5, wherein the method is characterized by the above.

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