JPH06240147A - Molding raw material containing continuous filament reinforced thermoplastic resin pellet - Google Patents

Abstract

PURPOSE:To obtain a resin molding raw material capable of providing a fiber reinforced composite material excellent in mechanical characteristics, especially tensile strength, tensile modulus, flexural strength and flexural modulus. CONSTITUTION:A molding raw material is composed of two or more kinds of pellets containing a continuous filament reinforced resin pellet using carbon fiber and a pellet of non-reinforced resin having same molecular structure as a matrix resin used in the continuous fiber reinforced resin pellet or a fiber reinforced resin pellet containing this resin as a matrix resin. In this molding raw material, as the resin material used for the pellet other than at least continuous filament reinforced thermoplastic resin pellet, a resin material having >45% lower limit value of breaking extension in non-reinforced state is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has mechanical properties such as
The present invention relates to a molding raw material capable of providing a fiber-reinforced composite material having excellent tensile strength, tensile elastic modulus, bending strength, and bending elastic modulus, and particularly to a molding raw material containing long fiber-reinforced thermoplastic resin pellets.

[0002]

2. Description of the Related Art According to Kelly's theory dealing with the strength of short fiber reinforced composite materials, a matrix resin having a strength σ _m has a strength σ _f corresponding to a fiber volume content V _f and a length L.
The strength σ _c of the composite material reinforced with the reinforcing material can be represented by σ _c = σ _f {1- (L _c / 2L)} V _f + σ _m (1-V _f ) ... (1) . Here, Lc is the critical fiber length. And if this equation (1) actually holds,
It can be seen that if the fiber length is increased, the strength can be dramatically improved.

By the way, the commercially available short fiber reinforced resin compounds are kneaded with a molten resin and a reinforced resin by an extruder and pelletized, so that the fibers are broken or highly filled in the pellet manufacturing process. There were problems such as difficulty in commercialization.

In order to solve such a problem, a method in which a molten resin is impregnated into a long fiber and the long fiber is cut (Japanese Patent Publication No. 43-7448 and Japanese Patent Publication No. 44-16793) or "parallel" is used. A pellet structure made by the pultrusion method, in which a continuous reinforcing filament bundle is impregnated with a thermoplastic resin and coated to be cut into a predetermined length (Japanese Patent Publication No. Sho 63-3769).
No. 4, etc.), and further, a resin sheet is impregnated with a resin to prepare a composite sheet, which is cut and pelletized, and then pressed into a mold to be molded (JP-A-3-
30916 gazette) was invented. And of these, the one currently on the market is ICI
"Verton (trademark)" manufactured by the company, "Cell Strand (trademark)" sold by Japan Polyplastics Co., Ltd., and the like are applicable.

[0005]

The use of so-called long-fiber-reinforced resin pellets as described above has certainly increased the fiber length in the molded product, but nevertheless, the fiber in the case where no special mold is used is used. The length is only about 2 to 3 times as long as when the short fiber reinforced resin pellets are used.

Therefore, attempts have been made to develop a molding raw material containing long fiber reinforced resin pellets in which the fiber length in the molded product becomes large. Specifically, JP-A 1-286
As seen in Japanese Patent No. 824, mixing resin pellets having a smaller melting start temperature than long-fiber-reinforced resin pellets,
This corresponds to a means for reducing the fiber breakage of the long fiber reinforced resin pellet by first plasticizing and melting the pellet having the lower melting start temperature by setting the cylinder temperature of the injection molding machine.

By examining the physical properties of test pieces molded using long-fiber-reinforced resin pellets currently on the market, the merit of long-fiber formation is expected to improve the physical property values predicted from Kelly's theory. It turned out to be too small compared to the generation. There is also a report that there is a large difference in the improvement of mechanical properties depending on the type of matrix resin, and the strength is smaller than that when short fiber reinforced resin pellets are used.

Therefore, under the present circumstances, application development is being conducted with a focus on "high packing" of fibers, which is one of the merits of the long fiber reinforced resin pellets rather than the effect of improving strength.

[0009]

From the above background, the object of the present invention is to
It is to provide molding raw materials containing long fiber reinforced resin pellets that maximize the advantages of long fiber.

[0010]

The present invention is directed to long-fiber-reinforced resin pellets using carbon fibers, and pellets of non-reinforced resin having the same molecular structure as the matrix resin used for the long-fiber-reinforced resin pellets. In a molding raw material composed of two or more types of pellets including a fiber-reinforced resin pellet containing a resin as a matrix resin, at least the resin material used for the pellets other than the long fiber-reinforced resin pellets has a breaking elongation in a non-reinforced state. It is characterized in that the lower limit value exceeds 45%.

By the way, if the above Kelly theory is accepted without any criticism, increasing the fiber length is the most effective means for improving strength. Although the strength of the matrix resin is also an influencing factor, considering that polyamide 66 (PA66), which has a lower yield strength than polyphenylene sulfide (PPS), has a much larger merit of making the fiber long,
Attention will be paid to the influence of fiber length.

Means for increasing the residual fiber length of the molded product include changing the screw and nozzle shape of the molding machine, changing the mold structure, and optimizing the molding conditions. Also, if it is intended to improve the strength by changing the characteristics of the forming raw material,
Means first come to mind to reduce fiber failure by reducing the melt viscosity of the matrix resin.

Taking this idea one step further, the invention disclosed in Japanese Patent Application Laid-Open No. 1-286824 attempts to reduce fiber breakage by blending a resin having a low melting start temperature. This invention seems to be very rational at first glance and can be expected to have an effect without conducting experiments, but in reality, a large effect is not always obtained.

FIG. 1 shows the influence of the dilution of polyamide 6 on the improvement of the impact strength of the polyamide 66 / long glass fiber system. The long glass fiber reinforced polyamide 66 pellets (manufactured by ICI in England, trade name: Verton) are shown. 2) and polyamide 6 pellets (trade name: Amilan, manufactured by Toray Industries, Japan) are mixed, the results show a notched Izod impact test of a test piece molded using a molding raw material. In this experiment, long-fiber-reinforced resin pellets having a higher melting start temperature disclosed in JP-A-1-286824 were PA66 /
The pellet corresponding to GF Verton and having a lower melting start temperature corresponds to PA6.

As is clear from FIG. 1, when the second resin having a low melting start temperature is blended, the residual fiber length is increased and the Izod impact strength is greatly improved. However, as shown in FIG. 2, the bending strength does not improve, but rather decreases. That is, JP-A-1-286824
The invention disclosed in Japanese Patent Publication is certainly effective in increasing the residual fiber length in a molded product and thereby improving the Izod impact strength, but is not necessarily effective in improving the static strength such as tensile strength and bending strength. It is not valid.

Continuous fiber-reinforced composite materials are available if long-fiber-reinforced resin pellets currently on the market, for example, the catalog of Celstran sold by Polyplastics Co., Ltd. has a fiber length of 2 to 3 times the critical fiber length. It is described that a strength of 75 to 83% of is obtained. However, it is a well-known fact that even if the long glass fiber reinforced resin pellets currently on the market are used, the strength as described in the above-mentioned catalog cannot be obtained.

FIG. 3 shows the fiber content dependency of the tensile strength of the polyamide 66 / glass fiber system.
6 shows the results of comparing the tensile strength of 66 / GF (LGF, SGF) series. Here, LGF is data obtained by using long fiber reinforced resin pellets, and SGF is data obtained by using short fiber reinforced resin pellets.
As is clear from FIG. 3, when the fiber weight content ratio is 30 wt%, no effect of the long fiber reinforced resin pellets is seen, and the merit of increasing the fiber content comes to be seen as the fiber content ratio increases, but still 10 to 10 It is only about 20 MPa.

Next, the famous Kerry's theory regarding the strength of the short fiber reinforced composite material will be described with reference to FIG.

According to Kerry's theory, since the matrix resin near the fiber ends yields, it is considered that the shear stress near the fiber ends is constant. The fiber stress is, as shown in FIG.
When the fiber length L exceeds the critical fiber length L _c , the trapezoidal shape shown in (C) of FIG. The stress distribution of the mold is shown. Since the fiber stress cannot exceed the fiber strength, in the case of a fiber having a fiber length equal to or greater than the critical fiber length, when the fiber stress reaches the fiber strength, the distance from the fiber end is 1 Fiber breakage occurs at any site except for a section smaller than / 2L _c . In this case, the critical fiber length: and _{L c,} fiber strength: and sigma _f, fiber diameter: and _{d f,} the yield strength of the matrix: between _{τ m, L c = σ f} / τ m · (d f / 2) Assuming that the relationship of (2) holds, the formula (1) is obtained by substituting in the compound rule.

By the way, let us consider whether the material development according to Kerry's theory is really correct.

First, it is assumed that Kelly's model is convenient for re-examination, that is, the interfiber distance is large due to the small fiber content, and therefore the influence of adjacent fibers can be ignored. Consider the possible conditions.

The assumption that the shear stress is constant because the matrix resin near the end of the fiber yields is an unavoidable assumption when considering a theoretical model, but this model that does not consider the breaking elongation of the matrix resin is really valid. Is it? I have to wonder.

If the matrix resin having a small elongation at break is used, if the matrix resin having a small elongation at break is used, the fiber should be broken from the end of the fiber by the shear stress before the fiber stress reaches the fiber strength. Is. In this case, if a matrix resin having a small elongation at break is used even if the fiber length becomes large, the strength should not be significantly improved. In other words, the theoretical strength calculated by Kelly's theory is an ideal value when using a matrix resin with a sufficiently large elongation at break (toughness), and cannot be corrected by statistically treating the orientation coefficient and fiber strength. become.

The present inventor has the above-mentioned doubts with respect to Kelly's theory, devised the following new model, and has developed a carbon long fiber reinforced resin pellet capable of providing a composite material having excellent strength characteristics. Invented the forming raw material containing.

The most important point of the present invention is to improve the strength by increasing the residual fiber length in the invention relating to the long fiber reinforced resin pellet or the molding raw material containing the same, whereas in the present invention, the residual fiber is generally retained. The point is to select a combination that reduces the fiber length.

As described above, there are many behaviors of the short fiber reinforced composite material which cannot be explained by Kelly's theory. The reason for this is that, in Kelly's theory, it is assumed that the shear stress is constant because the matrix resin near the fiber end yields,
The ultimate failure occurs when the fiber stress reaches the fiber strength. ”In practice, however, it is possible to conveniently assume that the shear stress is constant until the elongation at break of the matrix resin is reached. I thought there was.

FIG. 5 shows a simple model. 1 → 2 → 3
When the load increases in the order of, a plastic deformation region is formed in the vicinity of the fiber end due to the stress concentration generated at the fiber end. The shear stress may be considered to be almost constant when the matrix resin yields, but the shear deformation continues because the deformation of the matrix resin at the fiber end does not stop.
When a matrix resin having a small breaking elongation is used, the breaking elongation of the matrix resin is reached when the number reaches 4 in FIG. 5, so that shear fracture starting from the fiber end portion occurs and pulling out of the fiber occurs.

On the other hand, when a matrix resin having a large elongation at break is used, even if the load is further increased, the final failure is not easily achieved, and the failure at the point 3 in FIG. Leading to.

The theoretical strength should be even greater because Kerry's theory assumes that the elongation at break of the matrix resin will not be reached until fiber breakage occurs. In other words, if the breaking elongation of the matrix resin is small, the strength improvement should be small even if the fiber length becomes large. We come to the conclusion that a completely opposite approach, in which it is better to increase the elongation at break of the resin, is more appropriate.

The model shown in FIG. 5 corresponds to a state in which the influence of adjacent fiber ends can be ignored, that is, a state in which the fiber content is small. However, one of the merits of the long fiber reinforced resin pellets is that the strength improvement merits in the high fiber content region are often cited. Therefore, in the following, by considering the fracture mechanism model in the high fiber content region, Consider a molding material that maximizes the advantages of fiber-reinforced resin pellets.

FIG. 6 shows the observation results of the destruction process of 30 wt% short fiber reinforced polyether ether ketone. Essentially, as shown in FIG. 5, the strength of the composite material depends on the breaking elongation of the matrix resin. However, as the fiber content increases, the distance between the fibers decreases, so that the plasticity as shown in FIG. Deformation area coalescence occurs.

When the fiber content increases, the improvement in tensile strength may decrease or may decrease.
If this is to be explained by Kelly's theory, it can only be considered that the residual fiber length decreases as the fiber content increases. Certainly, as the fiber content increases, the residual fiber length decreases, but it is extremely rare that the residual fiber length decreases below the rate of increase in the fiber content. As the fiber content increases, the distance between the fiber ends decreases, and coalescence in the plastic deformation region easily occurs. Therefore, the strength increases due to the increase in the residual fiber length.

However, the strength is improved because coalescence is less likely to occur in the plastic deformation region due to the increase in the distance between the fiber ends, which is completely different from the meaning given by Kelly's theory. Therefore, for the reasons described below, the breaking elongation of the matrix resin is more important than the residual fiber length for improving the strength even in the high fiber content region.

FIG. 7 is an explanatory view showing the factors governing the strength of the short fiber reinforced composite material in the region where the fiber content is high,
As shown in FIG. 7, when the distance between the fiber ends is Z,
A fiber that transitions from a state of Z> Zc in which there is a sufficient distance between the fiber ends so that the plastic deformation regions generated near the fiber ends do not coalesce to a state of Z = Zc in which the plastic deformation regions coalesce There is a critical distance Zc between the ends. When short fiber reinforced resin pellets are used, when the fiber content is high, there is almost no exception, and a state of Z <Zc in which coalescence of plastic deformation regions occurs occurs. If long-fiber-reinforced resin pellets are used under the conditions of the same matrix resin and the same fiber content, the residual fiber length increases, and the distance between the fiber ends decreases, approaching the state of Z> Zc. Also,
In the range where the fiber content is not excessively large, the state of Z> Zc completely shifts. When carbon fibers are used as the reinforcing material, the residual fiber length when the short fiber reinforced resin pellets are used is only 100 to 150 μm, depending on the type of the matrix resin and the molding conditions.

Therefore, when the reinforcing material is carbon fiber, the long fiber reinforced resin pellets are certainly effective, but the strength improvement by using the long fiber reinforced resin pellets is still restricted by the elongation at break of the matrix resin. There is. Because, in the case of matrix resin with a small elongation at break,
Due to the relatively small increase in the residual fiber length, it becomes difficult for the plastic deformation regions near the fiber ends to coalesce, but even if the distance between the fiber ends becomes larger, the elongation at break of the matrix resin was reached. This is because the final destruction will occur at that point. That is, when a matrix resin having a large elongation at break is used, the strength improvement margin should be large when the fiber length increases.

Higher molecular weight grades generally have higher elongation at break when compared with the same matrix resin. But,
Since the higher the molecular weight grade is, the larger the melt viscosity is, the fiber becomes short when the fiber-reinforced grade is used, and therefore the high molecular weight grade is not used. In particular, when long-fiber-reinforced resin pellets are used, the purpose is to increase the length of the fibers, and therefore the matrix resin is not selected so as to reduce the length of the residual fibers even if the residual fiber length is increased. It was the basis of material development based on Kerry's theory to increase the residual fiber length even if the second resin having a low melting start temperature was blended.

As described above, according to the present invention, conventionally, less attention is paid as a method for improving strength,
At least focusing on the elongation at break of the matrix resin, which was not considered to be more effective than the fiber length, and assuming that it follows Kelly's theory that the residual fiber length becomes smaller in the molding raw material containing long fiber reinforced resin pellets, it is a disadvantage. Even after making such a trade-off, it was found that increasing the elongation at break of the matrix resin improves the strength of the composite material, thus completing the present invention.

In the molding raw material containing the long fiber reinforced thermoplastic resin pellets according to the present invention, a flame retardant, an antioxidant, an ultraviolet absorber, a lubricant, a coloring agent, a heat stabilizer and various stabilizers and lubricants, Needless to say, a filler or the like may be added within a range that does not impair the moldability and mechanical properties. Further, in the case of long fiber reinforced resin pellets using carbon fibers as a reinforcing material, molding often becomes difficult when the fiber content exceeds 40 wt%. Then, in the case of molding by the masterbatch method using long fiber reinforced resin pellets, the fiber content of the long fiber reinforced resin pellets is 60
The proportion of the resin in the long fiber reinforced resin pellets is small in order to set the content to ˜70 wt%. Therefore, when a molded product having a practical fiber content is manufactured, the resin in the pellet for dilution occupies the majority, so the lower limit of elongation at break of the resin constituting the long fiber reinforced resin pellet is 45%. It is not always necessary to do the above. In addition, the pellets may contain an appropriate amount of inorganic or organic fiber such as chopped glass fiber, ceramic fiber, aromatic polyamide fiber (trade name; aramid fiber), or continuous type of these fibers.

[0039]

【Example】

(Examples 1 and 2 and Comparative Examples 1 to 5) Hereinafter, the effects of the present invention will be described with reference to Examples and Comparative Examples. Prior to that, the mechanical properties of the matrix resins taken up in the Examples and Comparative Examples are described. The reasons taken as examples and comparative examples will be briefly described.

First, polyetheretherketone (PE
EK) is a crystalline polymeric material with very good toughness and PEEK 450G has an elongation at break of over 100%. Further, since both toughness and elongation at break have extremely large values, it is a resin that belongs to the category of the greatest improvement in strength when fiber-reinforced. Also, PEEK 151G
Is a low melt viscosity grade used for electric wire coating, and its strength is slightly higher than PEEK 450G, but its elongation at break is less than 1/10 of PEEK 450G.

However, since the melt viscosity is small, when the fiber is reinforced, the fiber is damaged during the molding process by PEEK 4.
Generally smaller than 50G.

If equation (1) really holds, PE
Since the strength of the matrix resin of EK 151G is larger and the residual fiber length is more likely to be larger, the use of PEEK 151G as the matrix resin is more effective than the case of using PEEK 450G as the matrix resin. The strength should be great.

Table 1 shows the ICI Victrex PE.
2 shows the mechanical properties of EK.

[0044]

[Table 1]

Next, polyether sanphone (PES)
Is an amorphous polymeric material with low toughness in contrast to PEEK. Further, PES 3600G and PES 4100G which are usually used for injection molding also have a considerably small elongation at break. In particular, since the toughness is small, there is a large variation in elongation at break, and if foreign matter or a defect is present, the material does not grow greatly and breaks. Therefore, it is a resin that has a smaller merit of fiber reinforcement than PEEK.

Table 2 shows Victrex P manufactured by ICI.
The mechanical properties of ES are shown.

[0047]

[Table 2]

Since the melt flow rate (MFR) of this PES decreases as the grade number increases,
The residual fiber length of the fiber reinforced grade decreases as the grade number of PES increases. Especially PES 4800
G, PES 5200P has a low MFR, and was therefore not suitable for fiber reinforced grades.

As described above, the crystalline PEEK having a high elongation at break and toughness and the amorphous PES having a low elongation at break and toughness are resin materials having exactly the opposite characteristics, and are the same as those of the present invention. These two resins were selected as examples because they are considered to be the optimum resins for demonstrating the effect by the examples and comparative examples. As the reinforcing fibers, those having an average fiber diameter shown in Table 3 were used.

[0050]

[Table 3]

Example 1 Polyetheretherketone (PEE, manufactured by ICI, UK)
K) A molding raw material (fiber content rate: fiber content rate: 67 wt%, carbon fiber: AS4, fiber length: 10 mm) mixed with “Victrex'PEEK '450G” and carbon long fiber reinforced polyether ether ketone resin pellets 5w
t%) was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded.

The tensile strength and tensile elastic modulus of the thus obtained test piece were measured according to ASTM D638. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. The results of various tests are shown in Table 4. The results of observing the fracture surface after the tensile test with a scanning electron microscope are shown in FIGS. 8 and 9.

Comparative Example 1 Polyether ether ketone (PEE manufactured by British ICI)
K) A molding raw material (fiber content rate: fiber content rate: 67 wt%, carbon fiber: AS4, fiber length: 10 mm) mixed with "Victrex'PEEK '151G" and carbon long fiber reinforced polyether ether ketone resin pellets 5w
t%) was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded.

The tensile strength and tensile modulus of the thus obtained test piece were measured according to ASTM D638. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. The results of various tests are also shown in Table 4. The results of observing the fracture surface after the tensile test with a scanning electron microscope are shown in FIGS.

[0057]

[Table 4]

Evaluation Example 1 As is clear from the test results shown in Table 4, in Example 1 of the present invention, the residual fiber length was smaller and the strength of the matrix resin was smaller than in Comparative Example 1. PEE
It can be seen that the tensile strength is higher when K 450G is used. Further, as is clear from the results of the fracture surface observation by the scanning electron microscope shown in FIGS. 8 to 11, PEEK 4
When 50G is used as the matrix resin, the matrix resin is greatly stretched due to the shear stress near the fiber ends, but when PEEK 151G is used as the matrix resin, it exhibits a brittle fracture pattern. It can be seen that the elongation at break limits the strength of the composite material.

Example 2 Polyethersulfone (PES) "Vi" manufactured by ICI of England
ctrex 'PES' 5200P "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content:
61 wt%, carbon fiber: T800, fiber length: 10 m
m) was mixed to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, under the molding conditions of mold temperature: 200 ° C., cylinder temperature: 350 ° C., screw rotation speed: 30 rpm, ASTM D638, ASTM D790.
A No. 1 dumbbell-shaped test piece conforming to the above was molded.

The tensile strength, tensile elastic modulus, elongation at break, bending strength, and bending elastic modulus of the test piece thus obtained were A
It was measured according to STM D638 and ASTM D790. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. 12 to 17 show tensile strength, tensile modulus, elongation at break, residual fiber length, bending strength,
The measurement result of a bending elastic modulus is shown.

Comparative Example 2 Polyethersulfone (PES) "Vi
ctrex 'PES' 3600G "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content:
61 wt%, carbon fiber: T800, fiber length: 10 m
m) was mixed to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours prior to molding.

Next, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, under the molding conditions of mold temperature: 200 ° C., cylinder temperature: 350 ° C., screw rotation speed: 30 rpm, ASTM D638, ASTM D790.
A No. 1 dumbbell-shaped test piece conforming to the above was molded.

The tensile strength, tensile elastic modulus, elongation at break, bending strength, and bending elastic modulus of the test piece thus obtained were A
It was measured according to STM D638 and ASTM D790. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. 12 to 17 show tensile strength, tensile modulus, elongation at break, residual fiber length, bending strength,
The measurement result of a bending elastic modulus is shown.

Comparative Example 3 Polyethersulfone (PES) "Vi
ctrex'PES '4100G "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content:
61 wt%, carbon fiber: T800, fiber length: 10 m
m) was mixed to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, under the molding conditions of mold temperature: 200 ° C., cylinder temperature: 350 ° C., screw rotation speed: 30 rpm, ASTM D638, ASTM D790.
A No. 1 dumbbell-shaped test piece conforming to the above was molded.

The tensile strength, tensile modulus, elongation at break, bending strength, and bending modulus of the thus obtained test piece were A
It was measured according to STM D638 and ASTM D790. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. 12 to 17 show tensile strength, tensile modulus, elongation at break, residual fiber length, bending strength,
The measurement result of a bending elastic modulus is shown.

Comparative Example 4 Polyethersulfone (PES) "Vi
Ctrex'PES '4800G "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content:
61 wt%, carbon fiber: T800, fiber length: 10 m
m) was mixed to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours prior to molding.

Next, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, under the molding conditions of mold temperature: 200 ° C., cylinder temperature: 350 ° C., screw rotation speed: 30 rpm, ASTM D638, ASTM D790.
A No. 1 dumbbell-shaped test piece conforming to the above was molded.

The tensile strength, tensile elastic modulus, elongation at break, bending strength, and bending elastic modulus of the test piece thus obtained were A
It was measured according to STM D638 and ASTM D790. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. 12 to 17 show tensile strength, tensile modulus, elongation at break, residual fiber length, bending strength,
The measurement result of a bending elastic modulus is shown.

Comparative Example 5 Polyethersulfone (PES) "Vi
ctrex 'PES' 3600G "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content:
61 wt%, carbon fiber: T800, fiber length: 10 m
m) was mixed to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, under the molding conditions of mold temperature: 200 ° C., cylinder temperature: 350 ° C., screw rotation speed: 30 rpm, ASTM D638, ASTM D790.
A No. 1 dumbbell-shaped test piece conforming to the above was molded. In addition,
After molding, heat treatment was carried out at 230 ° C. for 1 hour.

The tensile strength, tensile modulus, elongation at break, bending strength, and bending modulus of the test piece thus obtained were A
It was measured according to STM D638 and ASTM D790. In addition, the distribution of the carbon fiber length in the molded product was also measured. In this case, the fiber length distribution is measured by dissolving the test piece with concentrated sulfuric acid and then using an image analyzer (image processing device).
Was measured using. As a result, tensile strength: 145.4M
Pa, tensile modulus: 11.3 GPa, bending strength: 22
It was 0.1 MPa, flexural modulus: 8.43 GPa, average fiber length: 207.9 μm.

Evaluation Example 2 As shown in FIGS. 12 to 17, although the residual fiber length becomes larger when PES having a smaller grade number is used, the strength when reinforced with fibers is PES3600.
It is clear that there is no big difference whether G, PES 4100G or PES 4800G is used. The reason is that the use of PES having a smaller grade number results in a larger residual fiber length, but the break elongation of the matrix resin is also small and the contribution of the residual fiber length and the break elongation of the matrix resin are offset. Conceivable.

In addition, PES 5200P and PES 48
The difference in the melt flow rate (MFR) of 00G is relatively small.
Therefore, the difference in the residual fiber length is not so large. On the other hand, the lower limit of the elongation at break of the matrix resin is PES 48.
When using 00G, it is only 13.2%, while when using PES 5200P, it reaches 58.0%. In other words, when PES 5200P is used, the advantage that the elongation at break of the matrix resin is large is greater than the disadvantage that the residual fiber length is reduced, so the strength is specifically increased.

When PES 3600G is heat-treated at 230 ° C. for 1 hour, the static strength is greatly improved as shown in Table 2. At this time, the elongation at break is also reduced to about 1/2 of that before the heat treatment. The test results of Comparative Example 5 in which such heat treatment was performed are as described above, but as can be seen by comparing with the results of Comparative Example 1, when the strength of the matrix resin is increased and the elongation at break becomes small, the composite material As a result, the strength is reduced.

As is clear from the above results, the invention relating to the improvement of the strength of the molding raw material containing the long fiber reinforced resin pellets based on Kerry's theory does not always provide the effect as indicated by the formula (1). I know there isn't.

(Examples 3-5, Comparative Examples 6-9, 14) Next, by clarifying the relationship between the lower limit of the elongation at break of the matrix resin and the static strength, the influence of the decrease in the residual fiber length was examined. An experiment was carried out to determine the lower limit value of the elongation at break of the matrix resin capable of obtaining a sufficient static strength without being subjected to cracking. In this experiment, it is necessary to prepare matrix resins having different lower limits of elongation at break.

Therefore, PEEK natural materials having different lower limit values of breaking elongation, which are used in the following Examples and Comparative Examples,
Prepared PES natural material. And PEEK 1
51G and PEEK 450G, PES 4800G and P
ES 5200P was mixed using a V-type blender and then extruded using an extruder to obtain natural pellets. The lower limit of the elongation at break of the natural material thus obtained was measured using a No. 1 dumbbell test piece according to ASTM D638.

PEEK 151G and PEEK 450G
Blending ratio and PES 4800G and PES 52
The compounding ratio of 00P and the lower limit of elongation at break of the natural material corresponding thereto are shown in FIGS. 18 and 19, respectively.

Example 3 Polyetheretherketone (PEE, manufactured by ICI, UK)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK A in FIG. 18) obtained by mixing and extruding ictrex'PEEK '151G ", and carbon long fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: AS4, fiber length:
10 mm) mixed molding material (fiber content: 5 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The results of the tensile test are shown in FIG.

Example 4 Polyetheretherketone (PEE, manufactured by ICI, UK)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK B in FIG. 18) obtained by mixing and extruding ictrex'PEEK '151G ", and long carbon fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: AS4, fiber length:
10 mm) mixed molding material (fiber content: 5 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The results of the tensile test are also shown in FIG.

Comparative Example 6 Polyether ether ketone (PEE manufactured by British ICI)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK C in FIG. 18) obtained by mixing and extruding ictrex'PEEK '151G "and kneading and extruding, and carbon long fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: AS4, fiber length:
10 mm) mixed molding material (fiber content: 5 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The results of the tensile test are also shown in FIG.

Comparative Example 7 Polyetheretherketone (PEE manufactured by ICI, UK)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK D in FIG. 18) obtained by mixing and extruding ictrex 'PEEK' 151G "and kneading and extruding, and carbon long fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: AS4, fiber length:
10 mm) mixed molding material (fiber content: 5 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The results of the tensile test are also shown in FIG.

Evaluation Example 3 As can be seen from FIG. 20, a large improvement in tensile strength was confirmed in Examples 3 and 4 in which the lower limit of elongation at break of the matrix resin exceeded 45%, but the lower limit of elongation at break was confirmed. In Comparative Example 6 and Comparative Example 7 having a small value, almost no improvement in strength was observed.

Example 5 Polyether sulfone (PES) "Vi
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES A ′ in FIG. 19) and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is shown in FIG.

Comparative Example 14 Polyethersulfone (PES) "Vi
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES B ′ in FIG. 19) and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Comparative Example 8 Polyethersulfone (PES) "Vi
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES C ′ in FIG. 19) and carbon long fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Comparative Example 9 Polyethersulfone (PES) "Vi
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES D ′ in FIG. 19) and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 10 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Evaluation Example 4 As can be seen from FIG. 21, a large improvement in tensile strength was confirmed in Example 5 when the lower limit of the elongation at break of the matrix resin exceeded 45%. In Examples 8 and Comparative Example 9, almost no improvement in strength was observed.

(Examples 7 to 10 and Comparative Examples 10 to 13) Next, the case where the fiber content is relatively high, for example, the fiber content is 30 wt% will be described with reference to Examples and Comparative Examples. As the matrix resin, the above PEE
K and PES were used. Further, in order to investigate the influence of the lower limit of the elongation at break, B, B ′, C shown in FIGS.
The matrix resin of C'was also examined.

Example 7 Polyether ether ketone (PEE manufactured by ICI, UK)
K) A molding raw material (fiber content ratio: 30) in which "Victrex'PEEK '450G" is mixed with carbon long fiber reinforced polyether ether ketone resin pellets (fiber content ratio: 67 wt%, carbon fiber: IM7, fiber length: 10 mm)
wt%) was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is shown in FIG.

Comparative Example 10 Polyetheretherketone (PEE manufactured by ICI, UK)
K) A molding raw material (fiber content rate: 30) in which "Victrex'PEEK '151G" is mixed with carbon long fiber reinforced polyether ether ketone resin pellets (fiber content rate: 67 wt%, carbon fiber: IM7, fiber length: 10 mm)
wt%) was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Example 8 Polyetheretherketone (PEE, manufactured by ICI, UK)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK B in FIG. 18) obtained by mixing and extruding ictrex'PEEK '151G ", and long carbon fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: IM7, fiber length:
10 mm) mixed molding material (fiber content: 30 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Comparative Example 11 Polyetheretherketone (PEE manufactured by ICI UK)
K) "Victrex'PEEK '450G" and "V
PEEK natural pellets (PEEK C in FIG. 18) obtained by mixing and extruding ictrex'PEEK '151G "and kneading and extruding, and carbon long fiber reinforced polyether ether ketone resin pellets (fiber content: 67 wt%, Carbon fiber: IM7, fiber length:
10 mm) mixed molding material (fiber content: 30 wt
%) Was prepared and pre-dried at 150 ° C. for 5 hours prior to molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 210 ° C., the cylinder temperature was 390 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Example 9 Polyethersulfone (PES) "Vi
ctrex'PES '5200P "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 6
1 wt%, carbon fiber: T800, fiber length: 10 mm)
A molding raw material (fiber content: 30 wt%) was prepared by mixing the above, and pre-dried at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm, according to ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is shown in FIG.

Comparative Example 12 Polyethersulfone (PES) "Vi
ctrex'PES '4800G "and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 6
1 wt%, carbon fiber: T800, fiber length: 10 mm)
A molding raw material (fiber content: 30 wt%) was prepared by mixing the above, and pre-dried at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Example 10 Polyethersulfone (PES) "Vi" manufactured by ICI of England
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES B ′ in FIG. 19) and long carbon fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 30 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Comparative Example 13 Polyether Sulfone (PES) "Vi
"ctrex'PES '4800G" and "Victr
After mixing ex'PES '5200P ", kneading /
PES natural pellets obtained by extrusion (PES C ′ in FIG. 19) and carbon long fiber reinforced polyether sulfone resin pellets (fiber content: 61 wt
%, Carbon fiber: T800, fiber length: 10 mm) to prepare a molding raw material (fiber content: 30 wt%), and preliminary drying was performed at 150 ° C. for 5 hours before molding.

Then, using this molding raw material, in an injection molding machine with a mold clamping pressure of 75 TON, the molding temperature was 200 ° C., the cylinder temperature was 350 ° C., and the screw rotation speed was 30 rpm in accordance with ASTM D638. A No. 1 dumbbell-shaped test piece was molded. Then, the tensile strength of the test piece thus obtained was measured in accordance with ASTM D638. The result of the tensile test is also shown in FIG.

Evaluation Example 5 As shown in FIGS. 22 and 23, the lower limit of the elongation at break of the matrix resin was 4 even when the fiber content was high.
When it exceeds 5%, the strength is rather increased even if the residual fiber length is decreased.

[0117]

As described above, according to the present invention,
Contrary to the conventional invention based on the famous theory of Kerry, which is focused on increasing the residual fiber length, it is a matrix resin that shows the merit of improving the strength even if the residual fiber length is greatly reduced. It was found that the lower limit of the elongation at break exists, and the resin material used for at least the pellets other than the long fiber reinforced resin pellets has a lower limit of the elongation at break of more than 45%. It is possible to provide a molding raw material containing long-fiber-reinforced resin pellets that maximizes the advantages of long-fiber formation, and has excellent mechanical properties, particularly tensile strength, tensile elastic modulus, bending strength, and bending elastic modulus. The remarkable advantage is that a reinforced composite material can be obtained.

[Brief description of drawings]

FIG. 1 is a graph illustrating the influence of PA6 dilution on the improvement of impact strength of PA66 / LGF system.

FIG. 2 is a graph illustrating the influence of PA6 dilution on the change in bending strength of PA66 / LGF system.

FIG. 3 is a graph illustrating the fiber content dependency of the tensile strength of PA66 / GF (LGF, SGF) system.

FIG. 4 shows theoretical strengths of short fiber reinforced composite materials according to Kelly's theory, where L = L _c in (A) and L = L in (B).
_c and (C) are explanatory diagrams showing a case where L> L _c .

FIG. 5 is an explanatory diagram showing the reason why the strength of the short fiber reinforced composite material is different due to the difference in elongation at break of the matrix resin.

FIG. 6 is a copying diagram (2200 times) showing a scanning electron microscope observation result of coalescence of plastic deformation regions generated in the vicinity of fiber ends of short carbon fiber reinforced polyether ether ketone.

FIG. 7 is an explanatory diagram showing strength controlling factors of the short fiber reinforced composite material in a region where the fiber content is large.

FIG. 8 is a copying diagram (180 times) showing a scanning electron microscope observation result of a fracture surface of a 5 wt% carbon short fiber reinforced PEEK after using PEEK 450G after a tensile test.

FIG. 9 is a copying diagram (600 times) showing a scanning electron microscope observation result of a fracture surface of a 5 wt% short carbon fiber reinforced PEEK after using PEEK 450G after a tensile test.

FIG. 10: 5 wt% when PEEK 151G is used
It is a copying figure (180 times) which shows the scanning electron microscope observation result of the fracture surface after the tensile test of short carbon fiber reinforced PEEK.

FIG. 11: 5 wt% when PEEK 151G is used
It is a copying figure (1,200 times) which shows the scanning electron microscope observation result of the fracture surface after the tensile test of short carbon fiber reinforced PEEK.

FIG. 12 is a graph illustrating a relationship between PES grade and tensile strength of a composite material.

FIG. 13 is a graph illustrating the relationship between PES grade and tensile modulus of the composite material.

FIG. 14 is a graph illustrating the relationship between PES grade and tensile elongation at break of a composite material.

FIG. 15 is a graph illustrating a relationship between PES grade and residual fiber length of a composite material.

FIG. 16 is a graph illustrating a relationship between PES grade and bending strength of a composite material.

FIG. 17 is a graph illustrating the relationship between PES grade and flexural modulus of a composite material.

FIG. 18 is a graph illustrating the relationship between the PEEK blending ratio and the lower limit of elongation at break.

FIG. 19 is a graph exemplifying the relationship between the PES compounding ratio and the elongation at break lower limit value.

FIG. 20 is a graph illustrating the relationship between the lower limit of elongation at break of PEEK and the tensile strength of the composite material.

FIG. 21 is a graph illustrating the relationship between the lower limit of elongation at break of PES and the tensile strength of a composite material.

FIG. 22 is a graph illustrating the relationship between the lower limit of elongation at break of PEEK and the tensile strength of the composite material.

FIG. 23 is a graph illustrating the relationship between the lower limit of elongation at break of PES and the tensile strength of a composite material.

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[Procedure amendment]

[Submission date] February 19, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

FIG. 6 is a photograph (2200 times) showing a scanning electron microscope observation result of coalescence of plastic deformation regions generated in the vicinity of fiber ends of short carbon fiber reinforced polyether ether ketone.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

FIG. 8 is a photograph (180 times) showing a scanning electron microscope observation result of a fracture surface of 5 wt% short carbon fiber reinforced PEEK after using PEEK 450G after a tensile test.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

FIG. 9 is a photograph (600 times) showing a scanning electron microscope observation result of a fracture surface of a 5 wt% short carbon fiber reinforced PEEK after using PEEK 450G after a tensile test.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

FIG. 10: 5 wt% when PEEK 151G is used
It is a photograph (180 times) which shows the scanning electron microscope observation result of the fracture surface after the tensile test of short carbon fiber reinforced PEEK.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 11

[Correction method] Change

[Correction content]

FIG. 11: 5 wt% when PEEK 151G is used
It is a photograph (1,200 times) which shows the scanning electron microscope observation result of the fracture surface after the tensile test of short carbon fiber reinforced PEEK.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

[Figure 8]

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

[Figure 9]

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 11

[Correction method] Change

[Correction content]

FIG. 11

Claims (2)

[Claims] 1. A long fiber reinforced resin pellet using carbon fiber, a non-reinforced resin pellet having the same molecular structure as the matrix resin used for the long fiber reinforced resin pellet, or a fiber reinforced using this resin as a matrix resin. In a molding raw material composed of two or more kinds of pellets including resin pellets, a resin material used for at least the pellets other than the long-fiber-reinforced resin pellets having a lower limit of elongation at break of more than 45% in an unreinforced state. A molding raw material containing long-fiber-reinforced thermoplastic resin pellets. 2. The molding raw material containing long fiber reinforced thermoplastic resin pellets according to claim 1, wherein at least one of polyether ether ketone and polyether sulfone is used as the resin material.