JP3537651B2 - Method for producing fiber-reinforced resin composite molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced resin composite molded article in which fibrous fillers are dispersed in a non-oriented (isotropic) manner.

[0002]

2. Description of the Related Art Conventionally, metals have been frequently used as molded articles having excellent heat resistance, but in recent years, alternatives to resins have been studied in order to reduce weight and achieve high productivity. This resin molded body is required to have not only heat resistance but also strength, dimensional stability, chemical resistance and the like, and a thermosetting resin is suitable for this requirement.

Japanese Patent Application Laid-Open No. 64-87965 discloses a molding in which a fibrous filler (carbon fiber) is mixed with a thermosetting resin, and heat resistance and slidability are enhanced by injection molding, compression molding or transfer. Techniques for obtaining a body (resin pulley) have also been proposed.

[0004]

However, in such a molding method, the fibrous filler is contained in a state of being oriented in one direction, so that an internal stress remains and warpage occurs, and so-called weld or jute is generated. However, there is a problem in that molding distortion appears in the case of molding, flow marks, and the like, and as a result, the dimensional accuracy of the molded body is affected and the dimensional accuracy cannot be maintained. For example, cases, connectors, and
In the pulley disclosed in Japanese Patent No. 4-87965, deformation such as warping or twisting occurs in the orientation direction of the fibrous filler, and the deformation is corrected by using a jig.

In view of the above circumstances, the inventor of the present invention has intensively studied and found that a mixed material of a fibrous filler and a thermosetting resin material was powder-press-molded under predetermined conditions, and then heat-cured. It has been found that when this is done, the fibrous filler becomes a non-orientated random shape, so that internal stress does not remain and warpage does not occur, thereby improving dimensional accuracy.

Accordingly, the present invention has been completed based on the above findings, and has as its object the purpose of eliminating internal stress, preventing warpage, achieving high dimensional accuracy, and reducing manufacturing costs. The object of the present invention is to provide a fiber-reinforced resin composite material molded article.

[0007]

According to the present invention, there is provided a fiber-reinforced resin composite molded article in which a fibrous filler having an average yarn length of 150 μm or less is dispersed in a thermosetting resin, and the compounding ratio of the fibrous filler is determined by volume. The ratio is set to 70% or less, and the orientation is set to 0.9 to 2.0 in MOR-c value.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The fiber-reinforced resin composite molded article of the present invention loses the orientation of the fibrous filler by performing powder pressure molding from a raw material of a composite material of a thermosetting resin and a fibrous filler. Therefore, it becomes isotropic, and the compounding ratio of the fibrous filler can be further increased, and the volume ratio can be increased up to 70%, whereby the molded article obtained by subsequent heat curing has excellent dimensional accuracy. Become.

The mixing ratio of the fibrous filler can be increased to 70% by volume, so that warpage after molding,
This is advantageous in that the dimensional accuracy is improved, for example, deformation and torsion are reduced, the deflection temperature under load is improved, and high bending strength is obtained.

Preferably, the thermosetting resin is 70% to 30%.
%, The amount of the fibrous filler is preferably 30% to 70%, and most preferably, the thermosetting resin is 30% to 50%, and the fibrous filler is preferably 50% to 70%. In this case, the deformation during heat hardening in the powder pressure molding is reduced, the dimensional accuracy can be improved, and the powder pressure molding can be performed under optimal conditions.
By setting the value closer to 1, the fibrous filler can be isotropically dispersed.

The thermosetting resin includes phenol novolak resin, melanin resin, epoxy resin, polyimide resin and the like.

As the fibrous filler, ceramic fibers such as titania, carbon fibers, glass fibers, organic fibers such as aramid, and metal fibers such as phenol may be used because they are asbestos-free.

Further, the average yarn length of the fibrous filler is 150
It is preferable to use a short fibrous filler having a length of not more than μm, preferably not more than 100 μm, whereby the dispersibility when mixed is good and the non-oriented random shape is easily formed.

Further, with respect to the fibrous filler, the surface thereof may be coated with a coupling agent to further enhance the dispersibility.

The above-mentioned fibrous filler is mixed with a thermosetting resin, and a conventionally known additive,
For example, clay, talc, mica, kaolin, silica sand, calcium carbonate, alumina, silica, hydrated inorganic compounds, extenders such as graphite, or curing agents, curing aids, lubricants, plasticizers, dispersants, coloring agents, release agents May be added in small amounts.

The thermosetting resin, the fibrous filler and various additives are mixed, for example, by a mixer.
There is a method of kneading with a Brabender and pulverizing, or a method of melting and kneading the compound with a heating roll and then pulverizing. Further, it may be granulated to have a predetermined particle size as needed and used for molding.

Then, the uniformly mixed powder is subjected to powder pressure molding at room temperature, and then the molded body is released from the mold. According to this molding, since molding is performed at room temperature, deformation due to thermal expansion of the mold does not occur, and dimensional accuracy is improved. Moreover, since the raw material is not provided with fluidity as in injection molding, the fibrous filler loses orientation.

The molded body obtained as described above is cured in the next heat curing step. According to this step, the heat treatment temperature is preferably set in the range of 80 to 250 ° C., and an appropriate temperature is determined within the range using the properties of the thermosetting resin and the amount of the ceramics as parameters. In addition, if the volume of the molded body becomes large, the deformation can be prevented by increasing the keeping time of the set temperature.

Thus, according to the fiber-reinforced resin composite molded article of the present invention, powder pressure molding is carried out using the raw material of the composite material of the thermosetting resin and the fibrous filler having an average yarn length of 150 μm or less. By heating and curing the molded body, the orientation of the fibrous filler is 0.9 to MOR-c value.
2.0 and an isotropic molded body, and the compounding ratio of the fibrous filler can be further increased to 70% by volume,
In addition, since there is no molding distortion, correction for that is unnecessary, and as a result, the manufacturing cost is reduced and the dimensional accuracy is excellent.

In the case where the fiber-reinforced resin composite molded article of the present invention is provided with excellent sliding characteristics, or when the present invention is used as a sliding part, the mirror-finished treatment in the heat-curing step is performed. The surface smoothness may be improved by using a tool.

That is, in the case of a component (sliding component) requiring a high PV value, such as a bearing, a washer, a thrust plate, or the like, the resin shrinks in the above-mentioned heat-curing step when the above-mentioned fiber-reinforced resin composite material is molded. The resin surface is lowered, and a part of the fibrous filler is raised. For this purpose, a process such as polishing is performed. In the present invention, a jig (surface roughness Ra:
0.1 μm or less), which may enhance the surface smoothness. For example, in the case of a flat molded body, the molded body is heated and cured by sandwiching it with a mirror-finished jig, or A flat sliding member having a smooth surface with excellent sliding characteristics can be obtained by placing the device on a jig, applying a load thereon, and transferring the mirror surface.

[0022]

EXAMPLES The fiber-reinforced resin composite molding of the present invention will be described below using sliding parts as examples. (Example 1) Carbon fibers (average diameter 10 µm) obtained by changing the average length as a fibrous filler to a phenol novolak resin as a thermosetting resin as a raw material powder in various ways are shown in Table 1.
Are weighed and mixed so as to have a compounding ratio as shown in the following, and then the mixture is subjected to powder pressure molding at normal temperature so as to have a predetermined shape, and then separated from the mold, and then heated to a temperature of 80 to 250 ° C. Heat treatment was performed within the range to obtain various samples. However, the sample No. No. 7 was molded by an injection molding method, and other conditions were the same.

[0023]

[Table 1]

For each sample thus obtained, M
The OR-c value, the disc-specific wear amount, the ball-specific wear amount, the formability after powder compaction and the shape retention after heat treatment were measured.

For the MOR-c value, a molecular orientation meter (MOA-3001A manufactured by Oji Scientific Instruments) was used. The specific wear amount of the disk and the specific wear amount of the ball can be measured by the pin-on-disk method, and the disk material for that purpose is Al ₂ O ₃ , V = 5.
Comparative evaluation was performed under test conditions of m / sec and P = 1 kg.

Further, the moldability and the shape retention after heat treatment were evaluated by measuring the deflection temperature under load in accordance with JIS-K-7207. When a molded body with good dimensional accuracy was obtained, △ indicates that the molded body was brittle and the edge was chipped.

Regarding the shape retention after heat treatment,
評 価, ×, × were evaluated. ☆ indicates dimensional accuracy ±
In the case of 0.3% or less, ○ is when the dimensional accuracy is around ± 0.5%, Δ is when the dimensional accuracy exceeds ± 0.5%, and X is when the required shape is not obtained by deformation. .

As is clear from the results shown in Table 1, the sample No. of the present invention. In the case of Nos. 1 to 4, the MOR-c value was small, and the disc-specific wear amount and the ball-specific wear amount showed a self-wear type wear behavior.
As a result, wear of the disc is confirmed, and wear of the self (ball) is very small, which is suitable as a sliding material. Furthermore, the moldability and the shape retention after heat treatment were also good.

On the other hand, the sample No. In the case of 5 and 6, since the average length of the carbon fiber is 200 μm, its dispersibility becomes poor, and it becomes impossible to uniformly fill a mold. Therefore, the shape retention (dimensional accuracy) after heat treatment becomes poor, and good molding is performed. No product was obtained. In addition, the sample No. produced by the injection molding method. In No. 7, the MOR-c value was large.

(Example 2) In this example, glass fiber was used in place of the carbon fiber used in (Example 1), and the other conditions were the same. The body was made and evaluated similarly. However, the sample No. No. 14 was molded by the injection molding method, and the other conditions were the same.

[0031]

[Table 2]

As is clear from the results shown in Table 2, the sample No. of the present invention. 8 to No. For the sample No. 11, the MOR-c value was small, and the disc-specific wear amount and the ball-specific wear amount were the same as those of the sample No. 11 described above. 1 to No. As in the case of No. 4, good abrasion characteristics were obtained, and the moldability and the shape retention after heat treatment were also good.

The sample no. In Nos. 12 and 13, the average length of the glass fiber is as large as 200 μm, so that the dispersibility is poor, the mold cannot be uniformly filled, and the shape retention (dimensional accuracy) after the heat treatment is poor. In addition, the sample No. produced by the injection molding method. In No. 14, the MOR-c value was large.

(Example 3) A glass fiber (average diameter of 10) in which phenol novolak resin as a thermosetting resin as a raw material powder and an average length as a fibrous filler were changed in various ways.
μm) was weighed and mixed so as to have a compounding ratio shown in Table 3, and then the mixture was subjected to powder pressure molding at room temperature so as to have a predetermined shape, and then released from a mold. The molded body was sandwiched between mirror-finished jigs and heat-treated in a temperature range of 80 to 250 ° C. 15-17 were obtained. Also, in this heat treatment step, a mirror-finished jig was not used, and the other conditions were the same.
18-20.

[0035]

[Table 3]

Then, for each sample, the surface roughness R
a (μm) and the average area of the convex portions / average area of one filler (%) were measured. The surface roughness Ra is measured by a surface precision meter, and the average area of the protrusions / average area of one filler (%)
Was measured by performing image analysis with a LUZEX of a cross-sectional observation photograph by a metal microscope.

As is clear from the results shown in Table 3, the sample No. of the present invention. In Nos. 15 to 17, excellent surface smoothness was obtained as a sliding part. 18-20
Was inferior in surface properties.

(Example 4) In (Example 1) and (Example 2), a phenol novolak resin was used as a thermosetting resin.
Although carbon fibers and glass fibers were used as fibrous fillers, melanin resins, epoxy resins, and polyimide resins were used as thermosetting resins instead, and titania-based ceramic fibers and aramid-based organic fibers were further used as fibrous fillers. An example in which a phenolic metal fiber is used will be described.

[0039]

[Table 4]

As is clear from the results shown in Table 4, the sample No. of the present invention. In Nos. 22 to 28, excellent surface smoothness was obtained as a sliding part. 29-31
Was inferior in surface properties.

[0041]

As described above, according to the fiber-reinforced resin composite molding of the present invention, the thermosetting resin has an average yarn length of 150.
By dispersing the fibrous filler of not more than μm, the compounding ratio of the fibrous filler is reduced to 70% or less by volume, and the orientation thereof is set to 0.9 to 2.0 in MOR-c value, so that the internal stress is reduced. No longer remains and warpage does not occur, thereby achieving high dimensional accuracy and reducing manufacturing costs. For example, when the molded article of the present invention is in the shape of a case, there is no internal stress and no warpage, so that the dimensional accuracy is good, and the warpage and deformation during use (after thermal cycling) are small. Long-term high reliability cases were obtained.

Further, according to the present invention, the surface smoothness can be enhanced by using a jig mirror-finished in the heat curing step, whereby the molded article of the fiber reinforced resin composite material of the present invention can be slid. It became suitable for parts.

Claims (1)

(57) [Claims] 1. The thermosetting resin has an average yarn length of 150 μm or less.
Of fibrous fillers in a volume ratio of 30-70%
And then press forming the uniformly mixed powder at room temperature.
Transfer the mirror surface of the mirror-finished jig within 250 ° C
A method for producing a fiber-reinforced resin composite material molded article , wherein the orientation of the fibrous filler is adjusted to an MOR-c value of 0.9 to 2.0 by heat treatment .