JPH08283533A - Production of phenol resin molding material - Google Patents

Abstract

PURPOSE: To obtain a phenol resin molding material which has both a high impact strength and high static strengths by mixing a phenol resin, specific glass fibers, and a solvent with a high-speed mixer to give a chip-form compsn. wherein the glass fibers are separated into individual fibers and then thermally kneading the compsn. CONSTITUTION: 100 pts.wt. phenol resin and 75-260 pts.wt. glass fibers having diameters of 15-25μm and lengths of 0.5-12mm are charged into a Henschel mixer 1 preheated to 60-80 deg.C and are mixed with each other under stirring at the peripheral speeds of the upper blade 3 and lower blade 4 of 8-12m/sec for 10-30sec. Then, 5-15 pts.wt. solvent having a b.p. of 60 deg.C or lower (e.g. methanol) is added to the resulting mixture and mixed for 3-10min under deaeration, giving a chip-form compsn. having chip sizes of 3-10mm. The compsn. is fed by a measuring and supplying apparatus 6 from a discharge apparatus 5 to a granulator hopper 7. The compsn. put into a granulator cylinder 8 is extruded by the rotation of a screw 9 through a die 10 and cut with a cutter 11 into desired lenghts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides both a static strength and an impact strength by uniformly dispersing glass fibers in the manufacturing process of a molding material without impairing the length and enhancing the adhesion with a resin. The present invention relates to a method for producing a high-strength phenol resin molding material that is excellently balanced.

[0002]

2. Description of the Related Art Conventionally, phenol resin molding materials have been
It is used in a wide range of industries such as automobiles, electricity, and machinery due to its excellent properties such as heat resistance, mechanical strength, and electrical properties, and its relatively low cost. Conventional phenol resin molding materials are generally manufactured by mixing resin and glass fiber and compounding raw materials such as a filler, a curing agent, a release agent, and a coloring agent, and heating and kneading them using a roll kneader. . In recent years, a phenol resin molding material that has excellent viscosity stability during heating and melting and that is rapidly curable has been developed, and it has become possible to manufacture a phenol resin molding material using a biaxial kneader. Since the screw of the twin-screw kneader has a lower shearing action than the roll kneading, the glass fiber remains longer after the kneading. Therefore,
It is desirable as a kneading method for a molding material containing glass fiber, which requires high strength. However, in order to improve the adhesion between the phenol resin and the glass fiber, it is necessary to mount a kneading disk on a part of the twin screw. As a result, as the kneaded material passes through the kneading disc, the glass fibers are broken and shortened due to mutual interference of the glass fibers,
It is difficult to dramatically improve the reinforcing effect by blending glass fibers.

Starting with automobiles and electric parts, miniaturization and weight reduction are progressing, and higher functionality is required. Therefore, there is a strong demand for the development of a manufacturing method that can economically provide a large amount of a phenol resin molding material having high reliability in strength even in the design of thin-walled parts.

A conventional extrusion granulation method will be described with reference to FIG. The phenol resin compound composition in the blended matter / flex container (21) is quantitatively supplied to the hopper (23) of the twin-screw kneader by the constant-quantity feeder (22), and the heating cylinder (24) is rotated according to the rotation of the twin-screw (25).
The inside is advanced, the phenol resin and other compounding components are uniformly kneaded by the kneading action of the kneading disk (26) and extruded, and the kneaded product is transferred to the hopper (27) of the granulator. The kneaded product in the cylinder (28) of the granulator is extruded from the die (30) according to the rotation of the screw (29). (31) is a cutter blade, and (32) is a cutter rotating device. (33) and (34) are the motors of the granulator and the cutter rotating device, respectively. The kneaded material extruded from the die (30) is cut into a predetermined length by a rotating cutter blade (31) to form a molding material.

In such a conventional manufacturing method, the chopped strand glass fibers are loosened into single fibers and well dispersed in the compounded composition. Diameter (L /
D) = 13 to 20 and the screw of the extruder is L
A relatively long screw with / D = 5-10 is used.
Although the glass fibers are well dispersed and a uniform glass fiber distribution is obtained, the glass fiber length in the molding material is limited.

Further, as a conventional production method, there is a method of producing a granular phenol resin molding material by using a high-speed rotary mixer and adding a solvent of the phenol resin and mixing the mixture at high speed while heating. is there. In this manufacturing method, since it is possible to form a molding material with a minimum of breakage of glass fibers, a molding material excellent in impact strength can be obtained, but the kneading action is weak,
It is unsuitable as a method for producing a molding material in which the dispersion of glass fibers and the adhesion to a resin are poor, the static strength is lowered, and both impact and static strength are required to be compatible at a high level.

[0007]

The present invention has been obtained as a result of various studies in order to solve the problems in the production and characteristics of the conventional glass fiber base material / phenolic resin molding material as described above. The purpose is to leave the glass fiber in the molding material for a long time, enhance the dispersion of the resin and the glass fiber and the adhesion between the resin, and balance the static strength and impact strength, and both are excellent phenol resin molding materials Is in the place of providing.

[0008]

According to the present invention, 100 parts by weight of a phenol resin, 75 to 260 parts by weight of chopped strand glass fiber having a fiber diameter of 15 to 25 μm, and 5 to 15 solvents of a phenol resin having a boiling point of 60 ° C. or less are used. By mixing parts by weight with a high-speed mixer, the glass fibers are made into single fibers to obtain a chip-like phenol resin / glass fiber mixture, which is further kneaded by heating, and a method for producing a phenol resin molding material, preferably Relates to a method for producing a phenolic resin molding material, wherein the chip-like phenolic resin / glass fiber mixture mixed by a high-speed mixer is pelletized by a single-screw or twin-screw extrusion granulator having L / D = 1 to 4. It is a thing.

FIG. 1 is a schematic view for explaining the method for producing a phenol resin molding material of the present invention. An example of the method of the present invention will be described below with reference to FIG. (1) is a Henschel mixer main body, (5) is its discharge device, and (2) is a suction device. The phenol resin compound composition is put in the Henschel mixer main body (1), and the upper blade (3) and the lower blade (4) are rotated at a high speed of a peripheral speed of about 8 to 12 m / sec.
Mix and stir for 10 to 30 seconds. Then phenol resin 1
5 to 15 parts by weight of methanol are added to each of 00 parts by weight. Henschel mixer body is 60 ~ 8 in advance
Heat to about 5 ° C. After adding methanol, the mixture is made into chips in the size of 3 to 10 mm by operating the mixer while deaerating the volatile components with the suction device (2) for 3 to 10 minutes, and the constant amount supply device from the discharge device (5). By (6), it is transferred to the hopper (7) of the granulator, and extrusion granulation is performed by the method of FIG. 2 described above. The extrusion granulator can use either a single screw type or a twin screw type, but since the chip-like compound mixed with the solvent by heating is charged and extruded, the plasticizing step may be short. Therefore, as compared with the conventional manufacturing method, granulation can be easily performed even if the kneading screw in the cylinder of the extrusion granulator has a short length. The screw L / D of 1 to 4 is sufficient, and therefore good dispersibility is exhibited without breaking the glass fiber.

The phenolic resin composition used in the present invention is as follows. As the phenol resin, both novolac type and resol type can be used. In the case of the novolac type, hexamethylenetetramine is added as a curing agent by a conventional method. Any phenol resin can be used in the form of lumps, flakes, spheres, fine powders, or liquids, but it is preferable to use fine powders from the viewpoint of mixing workability.

As the glass fiber, chopped strands made of E glass are usually used. However, glass fibers other than E glass can be used depending on the application. In addition, the present invention is characterized in that glass fibers having a fiber diameter larger than that of glass used as a normal molding material, specifically, glass fibers having a diameter of 15 to 25 μm are used. By increasing the fiber diameter, breakage of glass fiber during manufacturing and molding is reduced,
High impact strength can be obtained. Further, since the glass surface area per unit weight is small, the adhesion between the phenol resin and the glass fiber is improved, and thus the static strength can be improved. If the fiber diameter of the glass to be used is 15 μm or less, the above effects cannot be sufficiently obtained, and if it is 25 μm or more, it is not preferable because the production of glass fibers and the molding material manufacturing facility become difficult. The fiber length of the glass fiber is important as one of the factors that influence the length of the glass fiber remaining in the molding material. 0.5 to 12 m in the manufacturing method of the present invention
Although m chopped strands can be used, 1.5 to 6 mm is preferable in terms of production efficiency.

Solvent having a boiling point of 60 ° C. or lower is phenol resin 1
It is 5 to 15 parts by weight with respect to 00 parts by weight. If the amount is less than 5 parts by weight, the monofilamentized glass fibers do not sufficiently adhere to the resin, resulting in insufficient chipping and granulation of the molding material. If the amount is more than 15 parts by weight, the volatile content increases and the resin increases. Dissolves in the solvent, making it difficult to mix it uniformly with the glass fibers. As such a solvent, methanol, acetone or the like can be used.

In addition to mechanical strength and electrical insulation, in order to maintain a good balance of physical properties such as heat resistance, dimensional stability, low linear expansion coefficient, wear resistance, water resistance, and moisture absorption, In addition to glass fibers, the production method of the present invention can be applied to a phenol resin molding material in which an inorganic filler such as glass beads, magnesium hydroxide, aluminum hydroxide, clay, mica, or silica is used alone or in combination.

Next, the features of the manufacturing method of the present invention will be described. Mix phenolic resin, chopped strand glass fiber and other ingredients in a heated high speed mixer.
Methanol is added before or after the mixing. When mixing and stirring are continued until the glass fiber becomes monofilament, the phenol resin is evenly wetted on the surface of the monofilament glass due to the evaporation of methanol, and as a result, the glass fiber becomes monofilament while maintaining the initial length, A chip-like mixture adhered to each other is obtained. By introducing this chip-like mixture to a kneading device such as an extrusion granulator, the glass fiber length is longer than in the conventional manufacturing method, the glass fiber is well dispersed in the molding material, and the adhesion with the resin is high. It becomes possible to manufacture a molding material. Preferably, the dispersibility of the glass fiber can be further improved by introducing the chip-like mixture into the extrusion granulator while maintaining the kneading temperature in the high speed mixer.

[0015]

EXAMPLES Examples of the present invention will be shown below. Table 1 is a table showing the compounding compositions of Comparative Examples 1, 2 and 3 and Examples 1 and 2, and Table 2 is a table showing the characteristics of each molding material.

[0016]

[Table 1]

[0017]

[Table 2]

(Measuring method of glass fiber length in molding material) About 2 g of molding material was heated in an electric furnace at 620 ° C., and the remaining ash was photographed with a microscope at a magnification of 50 times. The length was measured and averaged. (Mechanical strength) Each was measured according to the following standards. Charpy impact strength: JIS K 7111 Bending strength: JIS K 7203 The test piece was produced by injection molding.

In Comparative Example 2, after mixing water with the compounding composition of Table 1, the mixture was transferred in the cylinder with a twin-screw kneader having a cylinder temperature gradient of 20 ° C. (rear part) to 80 ° C. (front part), and before the screw. Heat kneading at the kneading disk part of the section, and discharge from the kneader exit. Then, this kneaded mixture was immediately introduced into an extrusion granulator having a cylinder temperature of 50 to 70 ° C. and a diameter of 3 m.
A cylindrical granular phenol molding material was obtained by extruding from a die having m.400 holes, cutting to a length of about 3 mm by a cutter rotating device, and then cooling. Comparative Example 3 is shown in Table 1.
After adding and mixing 4 parts by weight of water to 100 parts by weight of the phenol resin in the compounded composition of, the roll diameter was 16 inches, and the temperature was 70 to 90 ° C. on the high speed side and 20 to 40 ° C. on the low speed side on a biaxial dry hot roll. It is a conventional manufacturing method of kneading under pressure, taking out into a sheet, cooling and pulverizing to obtain a granular molding material.
In each of the comparative examples, the high shear increases the adhesion between the resin and the glass fiber and is excellent in static strength, but on the other hand, the glass fiber length in the material is short and the impact strength is low.

In each of Example and Comparative Example 1, the compounded composition of Table 1 was first mixed by a Henschel mixer having a bath temperature of 70 to 90 ° C. for about 30 seconds by the production apparatus of the present invention shown in FIG. 10 parts by weight of methanol was added to 100 parts by weight of the phenol resin, mixed for several minutes and discharged, and the resulting chip-like mixture was L / D = 3, and the cylinder temperature was 50 to 50.
Immediately introduced into the screw extruder granulator at 70 ℃, diameter 3
It was extruded from a die having a diameter of 400 mm and cut with a cutter rotating device to a length of about 3 mm and then cooled to obtain a cylindrical granular phenol molding material. Only the fiber diameter of the glass fiber used was different.

Comparing Example and Comparative Example 1 with other comparative examples having different manufacturing methods, the adhesiveness to the resin was increased while the glass fiber length was kept relatively long, and the impact strength and static strength were improved in a high dimension. It achieves both strength. Above all, in Examples, by using glass having a fiber diameter larger than that of the glass generally used for the molding material, further high strength is possible.

[0022]

According to the present invention, the glass fibers dispersed in the molding material remain for a long time, the adhesion between the glass fibers and the phenol resin is enhanced, and high mechanical strength is exhibited. In this way, by mixing with a high-speed mixer and extruding and granulating, and by using glass fiber having a large fiber diameter, a high-strength phenol resin molding material having excellent static strength and impact strength in a balanced manner is economical. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an apparatus used in the present invention.

FIG. 2 is a schematic cross-sectional view of a conventional phenol resin molding material manufacturing apparatus.

[Explanation of symbols]

 1 Henschel mixer main body 2 Suction device 3 Upper blade 4 Lower blade 5 Discharge device 6 Fixed amount supply device 7 Hopper 8 Cylinder 9 Screw 10 Die 11 Cutter blade 12 Cutter rotation device 13 Granulator motor 14 Cutter rotation device motor 21 Blend Matter / Flecon 22 Quantitative Supply Device 23 Hopper 24 Heating Cylinder 25 Twin Screw 26 Kneading Disc 27 Hopper 28 Cylinder 29 Screw 30 Die 31 Cutter Blade 32 Cutter Rotating Device 33 Granulator Motor 34 Cutter Rotating Motor

Claims (3)

[Claims] 1. A high-speed mixer is used to mix 100 parts by weight of a phenol resin, 75 to 260 parts by weight of glass fibers having a fiber diameter of 15 to 25 μm, and 5 to 15 parts by weight of a solvent of a phenol resin having a boiling point of 60 ° C. or less with a high-speed mixer. The glass fiber is made into a single fiber to obtain a chip-like phenol resin / glass fiber mixture,
A method for producing a phenolic resin molding material, which comprises further kneading this. 2. The glass fiber used has a fiber length of 0.5 to 1
The method for producing a phenolic resin molding material according to claim 1, which is 2 mm chopped strand glass fiber. 3. The chip-shaped phenolic resin / glass fiber mixture is added to a screw length / screw outer diameter (L
The method for producing a phenolic resin molding material according to claim 1 or 2, wherein pelletizing is carried out by a single-screw or twin-screw extrusion granulator of / D) = 1 to 4.