JPH0788841A - Resin composite material and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain an enough reinforcing effect of a glass fiber including the terminal end part as a whole when a molded item is prepd. by providing a distribution with two peaks in the length of the glass fiber mixed in a thermoplastic resin. CONSTITUTION:As the mean fiber length in a distribution with two peaks of the fiber lengths of glass fibers mixed in a thermoplastic resin, it is pref. that one of the peak is in the range of 5-40mm and the other is in the range of 90-110mm and the content of the glass fibers in a resin composite material is 20-60wt.%. For the resin composite material like this, when a biaxial kneading extruder is used and feeding parts for the glass fibers are provided at two positions, e.g., the first feeding part far from an outlet and the second feed part near the outlet, the glass fibers fed from the first feeding part becomes short in length and for the glass fibers fed from the second feeding part, the original length can be relatively well kept provide two peak distributions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composite material in which glass fibers are mixed in a thermoplastic resin and a method for producing the same. A resin molded product using this resin composite material can be used in fields such as automobiles and construction civil engineering.

[0002]

Background Art and Problems to be Solved by the Invention Resin molded articles having a thermoplastic resin as a matrix (base material) are roughly classified into a non-reinforced type and a reinforced type. The non-reinforced type resin molded product is obtained by extruding a molten resin into a mold by an extruder and press molding. This is limited to the case where a fiber or the like cannot be used for reinforcement or, if possible, an extremely short fiber is used.

On the other hand, in the case of a reinforced resin molded product, a web made of a resin mixed with long fibers such as glass fibers is heated,
It is manufactured by laminating or by matting needle-punched continuous fibers with a resin heated and impregnated. But,
The method for producing these resin molded products requires a few steps, and thus there is a problem that the production becomes complicated. Further, when the obtained resin molded product itself has a complicated shape, the strength was not necessarily satisfactory. That is, the entire molded product including the end of the molded product was not reinforced with glass fiber.

In the glass fiber reinforced thermoplastic resin manufacturing method, two supply ports are provided in the extrusion direction of the twin-screw extruder, and the first supply port is made of the thermoplastic resin and the second supply port is made of the thermoplastic resin. Glass roving is configured to be supplied respectively, or three supply ports are provided, a thermoplastic resin is supplied to the first supply port, glass roving is supplied to the second supply port, and glass beads are supplied to the third supply port. Although a structure configured to do so has been proposed (Japanese Patent Laid-Open No. 58-56818), the problem has not been solved yet. Therefore, an object of the present invention is to provide a resin composite material that can obtain a sufficient reinforcing effect by glass fibers as a whole including a terminal portion when a resin molded product is provided, and a method for producing the resin composite material.

[0005]

The present invention is a resin composite material in which glass fibers are mixed in a thermoplastic resin, wherein the glass fibers have two chevron shapes in the thermoplastic resin. It is characterized in that they are mixed in a content ratio having a distribution. The thermoplastic resin is polyethylene (PE), polypropylene (PP), nylon (N
y), polyester, polycarbonate, polystyrene and the like. The mountain-shaped distribution does not necessarily have to be symmetrical, such as a normal distribution. Further, the shapes of the mountain-shaped distributions on one side and the other side do not necessarily have to be the same. That is, the content ratio of relatively short glass fiber and relatively long glass fiber,
It may be different.

In the resin molded product obtained by using such a resin composite material, glass fibers are mixed therein in a content ratio having two chevron distributions with respect to the fiber length.
The reinforcing effect is enhanced. That is, even in the case of a resin molded product having a complicated shape, a relatively short glass fiber reaches the terminal part and the reinforcing effect by the glass fiber is exerted also at this terminal part, and in the other part, the relatively long glass fiber is used. Contributes to the development of strength (particularly impact strength). As a result, the strength of the molded product as a whole can be improved in addition to the end portion of the molded product.

On the other hand, the average fiber length of the mountain distribution is 5 to
A range of 40 mm is suitable, and if it is longer than this, the fluidity of the resin to the end parts and ribs of the molded product becomes poor. Also,
On the other hand, it is appropriate that the average fiber length of the chevron distribution is in the range of 90 to 110 mm, and longer lengths will not cause any inconvenience.
It usually does not exceed 150 mm. Resin composite material (resin +
The content of glass fiber in (glass fiber) is suitably 20 to 60 wt%. If it is less than 20 wt%, the reinforcing effect by the glass fiber cannot be obtained, and conversely, if it exceeds 60 wt%, the adhesion (wettability) between the resin and the glass fiber and the formability become poor.

Using the resin composite material according to the present invention, a desired resin molded product can be manufactured by stamping molding, press molding or the like. Further, a resin molded product such as a plate or a pipe can be manufactured by extrusion molding which is continuous with the manufacturing process of the resin composite material. The method for producing a resin composite material according to the present invention uses a hopper of a thermoplastic resin and a twin-screw kneading extruder having two feed portions of glass fibers along the resin extrusion direction, and the thermoplastic resin is applied to the hopper. Along with the feeding, glass fibers are fed from each of the feed sections.

The shape (width and height) of the chevron distribution can be controlled by adjusting the amount and ratio of the glass fibers fed into each feed section. The length of the glass fiber to be added is arbitrary. When the glass fiber is introduced into the twin-screw kneading extruder together with the thermoplastic resin, the glass fiber is cut by the kneading by the screw, so that the length of the original glass fiber is shortened. In the case of the same twin-screw kneading extruder, the length of glass fiber becomes shorter because the glass fiber charged from a position farther from the extruder outlet is kneaded for a longer time.

Therefore, in the twin-screw kneading extruder, the glass fiber feed portion is arranged along the resin extruding direction, for example, at a location far from the outlet (first feed portion) and a location near the second feed portion (second feed portion). When it is provided at a portion, the glass fiber put in from the first feed portion has a shorter length of the glass fiber and has a good degree of opening, and also has a good wettability with the glass fiber.
On the other hand, the glass fiber put in from the second feed portion has a relatively long length of the original glass fiber and has a good wettability to some extent.

In the present manufacturing method, the resin charged from the hopper needs to be completely melted when it reaches the vicinity of the first feed section. If the resin is not completely melted, the adhesion between the glass fiber and the resin will be poor. Further, since the glass fiber in the solid state and the resin are mixed, the abrasion of the screw or the cylinder may be increased. The molten state of such a resin can be controlled by changing the screw shape and barrel temperature.

Immediately before the second feed section, the glass fibers introduced from the first feed section must be opened. If the fibers are not opened, the opening of the glass fibers fed from the second feed portion is hindered, or the adhesion (wettability) between the glass fibers fed from the second feed portion and the resin becomes poor. The opened state of such glass fibers can be controlled by changing the screw shape and the distance between the first and second feed portions. By increasing the degree of openness of the glass fiber, the flowability and filling property of the glass fiber are improved, and the strength of details is also improved. In addition, since the uneven distribution of glass fibers is eliminated and the glass fibers are uniformly filled, the strength as a whole is improved.

By improving the wettability, physical properties such as tensile strength and bending strength are improved. The amount of glass fiber charged from each charging port of the first and second feed parts is
It is appropriate that the weight of the resin is within 2/3, and if it exceeds this, the glass fibers rub against each other to shorten the fibers, and the original strength may not be exhibited. The glass fibers to be put in are usually bundles of individual glass fibers (roving), but the number of bundles is 200
Approximately 20,000, the thickness of one glass fiber is approximately 9 to 23 μm. The operating temperature during kneading is about +30 to 80 ° C, which is the melting point of the thermoplastic resin.

[0014]

EXAMPLE The twin-screw kneading extruder used in this example is equipped with two screws for kneading and a hopper for charging a thermoplastic resin as usual, and in addition, a feed section for charging a glass fiber is provided in the resin extrusion direction. It is equipped with two along. Specific dimensions are, for example, a cylinder inner diameter of 40 mm and an L / D of 28. One of the feed parts (referred to as the first feed part) is
The feed section (second feed section) is provided substantially in the middle of the hopper and the extruder outlet, and is provided substantially in the middle of the first feed section and the extruder outlet. Therefore, the first feed portion is provided at a position far from the extruder outlet and the distance to the outlet is long, and the second feed portion is provided at a position close to the extruder outlet and the distance to the outlet is short. Has become.

Example 1 Using the above-mentioned twin-screw kneading extruder, GF reinforced PP, which is a resin composite material according to an example, was manufactured as follows, and further this G
Sheets and ribbed moldings made of F-reinforced PP were produced. First, prepare homo-grade polypropylene (MI = 20) as a thermoplastic resin, and use glass fiber (GF) roving as glass fiber [count 400 (0.4 g / m), single fiber 4
00 Convergence] was prepared. Adjust the extruder cylinder temperature to 210
℃, while maintaining the number of revolutions of the screw at 200 rpm, polypropylene was introduced from the hopper into the cylinder of the extruder, and 5 GF rovings were fed from the first feed section and 5 from the second feed section. And kneaded.

At the time of this kneading, P charged from the hopper
P was completely melted when it reached the vicinity of the first feed section. Also, immediately before the second feed section,
The GF introduced from the first feed section was opened. Then, a sheet was produced from this GF-reinforced PP as follows. That is, the GF-reinforced PP sheet discharged from the die (width 100 mm, thickness 3 mm) is cut out before it is solidified and put into a mold to form a GF-reinforced PP sheet with a thickness of 3.8 mm at a press pressure of 10 to 15 tons. did. Then, cut the periphery of this PP sheet to a width of 210 mm, a depth of 125 mm, and a thickness of 3.8 mm.
To obtain a rectangular GF-reinforced PP sheet.

The GF content in this sheet was 38.9 wt%. This "GF content" is measured by ashing a GF-reinforced PP sheet. GF in this sheet
Were mixed in two chevron-shaped normal distributions with respect to the fiber length. The width of the fiber length of one chevron distribution is 30-40 mm (average fiber length 35 mm), the content ratio is 50 wt%, the width of the fiber length of the other chevron distribution is 90-100 mm (average fiber length 95 m
m), and the content ratio was 50 wt%. This "G
The "F fiber length" is measured by ashing the produced GF-reinforced PP sheet, separating 50 GF fibers near the center thereof, and measuring the length with a straight line ruler. In this measurement, GF having a length of 2 mm or less was ignored because its amount was very small.

The wettability between GF and PP in this GF-reinforced PP sheet was good. This "wettability" is due to the fact that the surface of the GF-reinforced PP sheet is observed by an electron microscope and
It was evaluated by examining the bondability with. And GF
When a certain degree of conjugation between GF and PP was recognized, it was defined as “good”, and when GF and PP were completely separated, it was defined as “poor”. The GF-reinforced PP sheet had a good appearance. This "appearance" is evaluated by visually observing the surface. The case where the surface was smooth and GF was not visible was defined as “good”, and the case where GF was visible as a convex portion was defined as “poor”.

The opened state of this GF-reinforced PP sheet was good. This "opened state" is evaluated by GF-reinforced PP
The surface of the sheet was observed by an electron microscope and evaluated. The state in which the converged GF single fibers were opened and separated was defined as “good”. Next, a ribbed molded article was produced from the GF-reinforced PP as follows. That is, as in the case of the above-mentioned sheet, the resin composite material discharged from the die was put into a mold and molded at a press pressure of 10 to 15 tons to obtain a box-formed product 11 as shown in FIG. This molded product 11 is
Four side wall portions 13 to 16 are formed on the periphery of the rectangular bottom portion 12, and the first ribs 17 are respectively formed at the approximate centers of the long side wall portions 13 and 15.
And the second rib 18 is formed.

Specific dimensions are, for example, that one side of the bottom portion 12 is
250 mm, the other side is 150 mm, the height of the side walls 13 to 16 is 65 mm, the length of the first rib 17 is 50 mm, the height is 25 mm, the thickness is 3 mm, the length of the second rib 18 is 50 mm, The height is 5 mm and the thickness is 3 mm. The appearance and rib appearance of this molded product 11 were evaluated in the same manner as in the case of the above-mentioned sheet, and were good. When the GF filling rate of the first rib 17 was measured, it was 80% or more, and the evaluation was good. The "GF filling rate" is obtained by cutting the first rib 17 and performing soft X-ray photography on this test piece, and measuring the ratio of the cross-sectional area of the GF-filled portion shown as a shaded portion to the total cross-sectional area. It was done.
And 80% or more was made "good" and 50% or less was made "bad".

The GF filling rate of the side wall portion and the bottom surface portion was 0.90 or more, which was good. The "GF filling rate" was also measured in the same manner as the GF filling rate measurement of the first rib 17, and 0.90 or more was "good" and less than 0.90 was "bad". Then, a test piece was cut from the bottom surface portion 12 of the molded product 11, and various physical properties were measured on the test piece. Tensile strength was 1010 kg / mm ² , bending strength was 1840 kg.
/ Mm ² , flexural modulus of 69100, impact strength of 60 kg · cm / cm
^{Was 2} . Each physical property is measured by tensile strength ... ASTM
D638, flexural strength ... ASTM D790, flexural modulus ... ASTM D79
0, impact strength ... Performed based on ASTM D256.

Next, the shapeability of the GF-reinforced PP was examined as follows. That is, width 290 mm, depth 170
mm, 65 mm thick mold, using the rectangular GF reinforced PP
Stack 3 sheets, heating blank temperature 230-250 ℃,
The upper mold temperature was 50 to 60 ° C., the lower mold temperature was 30 to 45 ° C., the pressing pressure was 140 kg / cm ² , and the pressing time was 20 seconds. As a result of this molding test, all five samples could be completely shaped, and the evaluation was good. It should be noted that a ratio of 3/5 or more that could be completely shaped was evaluated as “good” and a ratio of 2/5 or less as “poor”.

Examples 2 to 5 GF-reinforced PP according to each example was manufactured in the same manner as in Example 1, and a sheet and a ribbed molded product made of this GF-reinforced PP were manufactured. However, in each example, when kneading with an extruder, the number of GF rovings to be fed from the first feed section and the second feed section, respectively, was determined as “G” in Tables 1 and 2.
The method was changed as shown in the column of “F roving charging method”. Then, regarding the rectangular GF-reinforced PP sheet according to each example, in the same manner as in Example 1, the GF content, the GF fiber length,
The wettability, the appearance and the opened state were measured and evaluated.

The results of these measurements and evaluations are shown in Tables 1 and 2. In the column of GF roving charging method in the table, F1 represents the first feed section and F2 represents the second feed section. next,
A ribbed molded product 11 according to each example was manufactured in the same manner as in Example 1 from GF-reinforced PP. Then, this ribbed molded product 11 was measured and evaluated in the same manner as in Example 1 for the appearance, rib appearance, rib GF filling rate, GF filling rate of the side wall portion and the bottom surface portion, and various physical characteristics. Next, the shapeability of the GF-reinforced PP according to each example was also examined in the same manner as in Example 1.

Comparative Examples 1 to 5 GF-reinforced PP according to each comparative example was manufactured in the same manner as in Example 1, and a sheet and a ribbed molded product made of this GF-reinforced PP were manufactured. However, in each example, when kneading with an extruder, the number of GF rovings fed from the first feed section and / or the second feed section was set to "GF" in Tables 3 and 4.
The method was changed as shown in the column of "Roving input method". Then, with respect to the rectangular GF-reinforced PP sheet according to each comparative example, the GF content, the GF fiber length, the wettability, the appearance and the opened state were measured and evaluated in the same manner as in Example 1.

The results of these measurements and evaluations are shown in Tables 3 and 4. Next, a ribbed molded product according to each comparative example was manufactured from GF-reinforced PP in the same manner as in Example 1. Then, with respect to this ribbed molded article, in the same manner as in Example 1, the appearance,
The rib appearance, the rib GF filling rate, the GF filling rate of the side wall portion and the bottom surface portion, and various physical properties were measured and evaluated. next,
The shapeability of the GF-reinforced PP according to each comparative example was also examined in the same manner as in Example 1.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

From Tables 1 and 2, according to the GF-reinforced PP sheets according to Examples 1 to 5, GF was mixed in a content ratio having two chevron distributions with respect to the fiber length, and one of the chevron distributions had an average fiber length. 5-40 mm, mean fiber length of the other chevron distribution is 90
~ 110 mm and glass fiber content of 20 ~
Since it is in the range of 60 wt%, it is understood that the wettability, the appearance and the opened state are good. Therefore, since the wettability and the spread state are good, the reinforcing effect of GF can be sufficiently exerted.

Further, according to the ribbed molded product 11 according to each example, the appearance, the rib appearance, the rib GF filling rate, the GF filling rate of the side wall portion and the bottom surface portion, and various physical characteristics are good. Recognize. Therefore, since the GF having a short fiber length is sufficiently distributed to the ribs 17 and 18 of the molded product 11, the ribs 17 and 18 and the molded product 11 as a whole are G
A sufficient reinforcing effect by F can be obtained. Furthermore, it can be seen that the GF-reinforced PP according to each example also has good shapeability. Therefore, there is no problem in molding due to the two peak distribution of the present invention.

On the other hand, the GF-reinforced P according to Comparative Examples 1, 2, and 4
According to the P sheet, since GF is mixed in the fiber length not in two chevron distributions but in one chevron distribution, the wettability, the appearance, and the opened state are poor as shown in Tables 3 and 4. There is. Further, according to the ribbed molded products of Comparative Examples 1, 2, and 4, the appearance, the rib appearance, the rib GF filling rate, the GF filling rate of the side wall portion and the bottom surface portion, and various physical characteristics are also shown in Tables 3 and 4. It may be defective as shown. Therefore, when the rib GF filling rate is poor as in the ribbed molded products according to Comparative Examples 1 and 4, the ribs of the molded product are not sufficiently filled with GF, and a sufficient reinforcing effect can be obtained with this rib. There is a fear that it will not.

Regarding the shapeability, Comparative Examples 1, 2,
All of the GF-reinforced PPs of No. 4 were good. According to the GF-reinforced PP sheet according to Comparative Example 3, GF is mixed at a content ratio having two chevron distributions with respect to the fiber length, but the other chevron distribution has a short average fiber length of 70 mm and G
Since the content of F exceeds 60 wt%, the wettability, the appearance and the opened state were poor. Further, in the case of Comparative Example 3, an attempt was made to produce a ribbed molded product, but the content of GF was too large and the flowability was poor, and molding was not possible.

Further, the GF-reinforced PP according to Comparative Example 3 was also poor in shapeability. According to the GF-reinforced PP sheet according to Comparative Example 5, GF is mixed in a content ratio having two chevron distributions with respect to the fiber length, but since the mean fiber length of the other chevron distribution is as short as 50 mm, the wettability, The appearance and the opened state were poor. In addition, according to the ribbed molded product of Comparative Example 5, the appearance, the rib appearance, the rib GF filling rate, and the GF filling rate of the side wall portion and the bottom portion were also poor. Furthermore, the GF-reinforced PP according to Comparative Example 5 was also poor in shapeability.

[0036]

EFFECTS OF THE INVENTION According to the resin composite material and the method for producing the resin composite material according to the present invention, when a resin molded product is obtained, a sufficient reinforcing effect by the glass fiber including the end portion can be obtained as a whole.

[Brief description of drawings]

FIG. 1 is a perspective view of a ribbed molded product made of F-reinforced PP according to an embodiment of the present invention.

[Explanation of symbols]

 11 Box-formed product 17 First rib 18 Second rib

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Narutoshi Wada 2 Chitose-cho, Yokkaichi-shi, Mie Idemitsu NSG Co., Ltd. (72) Kenji Sudo 2 Chitose-cho, Yokkaichi-shi, Mie Idemitsu NGS Co., Ltd. ( 72) Inventor Manabu Nomura 1 Inezaki Kaigan Co., Ltd. 1 Anezaki Kaigan, Ichihara City, Chiba Prefecture

Claims (3)

[Claims] 1. A resin composite material in which glass fibers are mixed in a thermoplastic resin, wherein the glass fibers are mixed in the thermoplastic resin in a content ratio having two chevron distribution with respect to the fiber length. A resin composite material characterized by the above. 2. An average fiber length of one chevron distribution of the glass fibers is 5 to 40 mm, and an average fiber length of the other chevron distribution is 90 to
It is in the range of 110 mm and the glass fiber content is 20
The resin composite material according to claim 1, wherein the content is -60 wt%. 3. A twin-screw kneading extruder equipped with a thermoplastic resin hopper and two glass fiber feed portions along the resin extrusion direction is used, and the thermoplastic resin is introduced into the hopper and each of the feeds is fed. The method for producing a resin composite material according to claim 1 or 2, wherein glass fibers are charged from a portion.