JPH0780830A - Production of phenol resin molding material - Google Patents

Abstract

PURPOSE:To enhance a strength of a phenol resin molding material by a method wherein a chip resin/fiber compound is prepared by mixing specific amounts of a phenol resin, a chopped strand glass fiber, an NBR, and a solvent by a high-speed mixer and making the glass fiber into a single fiber, and the compound is pelletized by a twin-screw extrusion pelletizer. CONSTITUTION:A mixture of 100% phenol resin, 160% chopped strand glass fiber of 6mm cut length, 15% NCR, and 8% phenol resin solvent having a boiling point of 60 deg.C or lower is compounded and stirred by a Henschel mixer 1. The compound is stirred and deaerated by a suction device 2 with the addition of 5-10% methanol to be made into a chip form. The chip compound is pelletized by a twin-screw extrusion pelletizer 9. In this manner, the compatibility of the resin with the NBR is enhanced by the kneading heat generation action of screws. The glass fiber is ideally dispersed while still having a long glass fiber length. A phenol resin molding material superior in toughness and strength can be produced.

Description

Detailed Description of the Invention

[0001]

Industrial Field of the Invention The present invention leaves glass fibers in a molding material for a long time to improve the adhesion to a resin, and improves the toughness by blending NBR, resulting in an excellent balance between static strength and impact strength. The present invention relates to a method for producing a high-strength phenolic resin molding material which has excellent properties.

[0002]

2. Description of the Related Art Conventionally, phenol resin molding materials have been
Excellent performance such as heat resistance, mechanical strength characteristics, electrical properties,
Due to its relatively low cost, it is used in a wide range of industries such as automobiles, electricity and machinery. Conventional phenol resin molding materials include resin, glass fiber and filler,
A general method is to mix compounding raw materials such as a curing agent, a release agent, and a colorant, and heat and knead them mainly by using a roll kneader. In recent years, the development of a fast-curing phenolic resin having excellent viscosity stability under heat has enabled the production of a phenolic resin molding material by biaxial extrusion. Since the screw of the twin-screw extruder has a lower shearing action than that of roll kneading, the glass fibers are likely to remain long. 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 the mutual interference of the glass fibers, and it is difficult to dramatically improve the reinforcing effect of the glass fibers. Starting with automobiles and electric parts, they are becoming smaller and lighter, 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.

In FIG. 2, a conventional extrusion granulation method will be described. The phenol resin blended composition in the blended matter / flex container (21) is quantitatively supplied to the hopper (23) of the twin-screw extruder by the constant-quantity feeder (22), and the heating cylinder (with the rotation of the twin-screw (25) ( 24)
The inside is advanced, and the kneading disk (26) kneads the phenol resin and the other compounding ingredients uniformly to extrude the kneaded material, and the kneaded product is transferred to the hopper (27) of the granulator. The kneaded product in the cylinder (28) of the granulator is
It is extruded from the die (30) as the screw (29) rotates. (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 kneading material extruded from the die (30) is cut into a predetermined length by a rotating cutter blade (31) to form a molding material.

In the conventional manufacturing method, the chopped strand glass fibers are loosened into single fibers and well dispersed in the compounded composition. Therefore, the screw of the twin-screw extruder used is L.
/ D = 13 to 20, and the screw of the extrusion granulator 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 manufacturing method, there is a method in which a phenol resin compounding composition is placed in a high-speed rotating mixer, a solvent of the phenol resin is added, and the mixture is mixed at high speed while heating to form a granular phenol resin molding material. In this production method, since the kneading action is weak, when a phenol resin having a high melting point is used, the dispersion of glass fibers tends to be poor,
When rubber such as NBR is blended, the rubber is not sufficiently dispersed, and when molded, the appearance of the molded product becomes poor.

[0005]

The present invention has been obtained as a result of various studies for solving the problems in the production of the conventional glass fiber base material / phenolic resin molding material as described above. Where the glass fiber in the molding material is left for a long time, the adhesion between the resin and the glass fiber is improved and NBR is increased.
The object of the present invention is to provide a method for producing a phenolic resin molding material, which is improved in dispersibility and has a good balance between static strength and impact strength.

[0006]

The present invention comprises 100 parts by weight of a phenolic resin, 75 to 260 parts by weight of chopped strand glass fiber having a cut length of 0.5 to 12 mm, and NBR.
5 to 20 parts by weight and 5 to 10 parts by weight of a solvent of a phenol resin having a boiling point of 60 ° C. or less are mixed with a high-speed mixer, and the glass fibers are made into single fibers to obtain a chip-like phenol resin / glass fiber mixture. Is further kneaded, and a method for producing a phenol resin molding material, further comprising a chip-shaped phenol resin / glass fiber mixture mixed by a high-speed mixer, L / D = 1 to 4 Alternatively, the present invention relates to a method for producing a phenol resin molding material, which comprises pelletizing with a twin-screw extrusion granulator.

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. Next, 5 to 15 parts by weight of methanol is added to 100 parts by weight of the phenol resin. The Henschel mixer body is preheated to about 60 to 85 ° C. After adding methanol, degassing the methanol with the suction device (2) for 3 to 10 minutes while rotating the mixer to form chips with a size of 3 to 10 mm, and from the discharge device (5) to the constant amount supply device (6), The particles are transferred to the hopper (7) of the granulator and extruded and granulated by the same method as that shown in FIG. The extrusion granulator may be either a single screw type or a twin screw type, but the plasticizing step may be short because the chip-form compound mixed with the solvent and heated is charged and extruded. 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 production method of the present invention is as follows. As the phenolic resin, both novolac type and resol type can be used. In the case of novolac type, hexamethylenetetramine is added as a curing agent by a conventional method. Any of the phenolic resins may be used in the form of lumps, flakes, spheres, fine powders, or liquids, but fine powdery phenolic resins are preferable from the viewpoint of mixing workability. As the type of glass fiber, chopped strands made of E glass are used. However, glass fibers other than E glass can be used depending on the application. The cut 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. In the production method of the present invention, chopped strands of 0.5 to 12 mm can be used, but 1.5 to 6 mm in terms of production efficiency.
The thing of is desirable.

In addition to strength and electrical insulation, heat resistance,
In addition to glass fiber, glass beads, magnesium hydroxide, aluminum hydroxide, clay, and mica are used to maintain a good balance of physical properties such as dimensional stability, low linear expansion coefficient, wear resistance, water resistance, and moisture absorption. The production method of the present invention can be applied to a phenol resin molding material in which an inorganic filler such as silica is used alone or in combination. In the above compounded composition, 100 parts by weight of the phenol resin was added to N.
In the case of blending 5 to 20 parts by weight of BR, the NBR is poorly dispersed only by the high speed mixer, but the compatibility between the phenol resin and the NBR is increased due to the kneading heat generation effect of the extruder granulator screw, and the glass fiber length is not deteriorated. Exhibits excellent dispersibility. A commercially available NBR can be used.

Next, 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. Mixing and stirring were continued until the glass fiber became a single fiber, and then the phenol resin was uniformly wetted on the surface of the single fiber glass by evaporation of methanol, and as a result, the glass fiber became a single fiber while maintaining the initial length. A chip-like composition in which glass fibers are attached to each other is obtained. By introducing this chip-like compound to a kneading device such as an extrusion granulator, it is possible for the first time that the glass fibers are better dispersed in the molding material and the glass fiber length remains longer than in the conventional manufacturing method. became. Preferably, the dispersibility of the glass fibers can be further improved by introducing the chip-like composition into an extrusion granulator while maintaining the kneading temperature in a high speed mixer.

[0011]

EXAMPLES Table 1 shows Comparative Examples 1 and 2 and Examples 1, 2, and 3.
2 is a composition table of

[Table 1]

Comparative Examples 1 and 2 are conventional manufacturing methods. Comparative Example 1 has the composition shown in Table 1 and has a cut length × diameter = 3 mm ×
After adding and mixing 10 parts by weight of water to 100 parts by weight of a composition using 13 μm chopped strand glass fiber, a twin screw extruder shown in FIG. 1 was used to obtain a cylinder temperature gradient of 20 ° C.
(Rear part) to 80 ° C (front part), screw rotation speed 200
The mixture was transferred in the cylinder at rpm, heated and kneaded at the kneading disk portion in front of the twin screw, and discharged from the extruder outlet. The kneaded mixture is immediately introduced into an extrusion granulator having a cylinder temperature of about 70 ° C., extruded from a die with 3 mmφ · 400 holes at a screw rotation speed of 10 to 20 rpm, cut into a length of about 3 mm by a cutter rotating device, and immediately air-cooled. By doing so, a cylindrical granular phenol resin molding material was obtained. 25 glass fibers in the molding material
4 μm, Izod impact strength was 50 J / m, and bending strength was 120 N / mm ² .

In Comparative Example 2, the same compounding composition as in Comparative Example 1 was mixed for 10 seconds with a Henschel mixer at a temperature of about 70 ° C., and methanol was added in an amount of 10 per 100 parts by weight of the phenol resin.
Add parts by weight, mix for 5 minutes, discharge the mixture, and
An m-shaped rice husk-shaped chip molding material was obtained. The glass fiber length in the molding material is as long as 2590 μm, and the Izod impact strength is as high as 250 J / m, but the bending strength is as low as 89 N / mm, and small blurring defects due to NBR particles occur on the appearance surface of the molding product, resulting in a molding material. Is not suitable.

In Example 1, a composition using the chopped strand glass fiber having a cut length × diameter = 6 mm × 13 μm having the composition shown in Table 1 was compared with Comparative Example 1 by the production apparatus of the present invention shown in FIG. Similarly, a Henschel mixer having a temperature of about 70 ° C. was mixed for 10 seconds, 10 parts by weight of methanol was added to 100 parts by weight of the phenol resin, and the mixture was discharged for 5 minutes to obtain a chip-like composition. This formulation is L / D
= 3 for screw extrusion granulator, cylinder temperature approx. 70 ° C, screw rotation speed 20 rpm, 3 mmφ ・ 4
Extruded from a 00-hole die and length 3 by cutter
It was cut to about mm and immediately air-cooled to obtain a cylindrical granular phenol resin molding material. Although the glass fiber length and Izod impact strength of the molding material are lower than those of Comparative Example 2, NBR is well compatible with the phenol resin and has no defect in the appearance of the molded product.
Moreover, since the glass fibers sufficiently longer than in Comparative Example 1 were well dispersed and present, both the Izod impact strength and the bending strength were excellent and the results were balanced.

In Example 2, as in Example 1, chopped strand glass fibers having a cut length × diameter = 3 mm × 9 μm with the composition shown in Table 1 were used, and the amount of methanol added after mixing with a Henschel mixer was phenol resin 100. By increasing the amount to 16 parts by weight with respect to parts by weight, a cylindrical granular phenol resin molding material having a length of about 3 mm could be easily obtained under the same conditions as in Example 1 by the manufacturing apparatus of the present invention in FIG.
The glass fiber length in the molding material, the Izod impact strength, the bending strength, and the appearance evaluation of the molded product are as summarized in Table 2, showing that they are all superior to Comparative Example 1.

In Example 3, as in Example 1, chopped strand glass fibers having a cut length × diameter = 3 mm × 13 μm with the composition shown in Table 1 were used, and the amount of methanol added after mixing with a Henschel mixer was phenol resin 100. By reducing the amount to 6 parts by weight, the cylindrical granular phenol resin molding material having a length of about 3 mm could be easily obtained under the same conditions as in Example 1 by the manufacturing apparatus of the present invention in FIG.
The glass fiber length in the molding material, the Izod impact strength, the bending strength, and the appearance evaluation of the molded product are as summarized in Table 2, showing that they are all superior to Comparative Example 1.

[0017]

[Table 2] (Measuring method of glass fiber length in molding material) Molding material 2 g
It is heated at an electric furnace temperature of 620 ° C., and the remaining ash is photographed with a microscope photograph of 50 times, and then all the glass fibers on the photograph are measured to have an average length. (Mechanical strength characteristics) According to JIS K 6911. The test piece was prepared by compression molding. (Appearance of Molded Article) The appearance of the test piece for mechanical strength properties was visually evaluated.

[0018]

When the production method of the present invention is used, the glass fibers dispersed in the molding material remain for a long time, and the adhesion between the glass fibers and the phenol resin is enhanced, so that high strength is exhibited. Further, excellent toughness and good appearance are exhibited due to good compatibility between NBR and phenol resin. In this way, a high-strength phenol resin molding material in which excellent static strength and dynamic strength such as impact resistance are balanced is economically produced in large quantities by mixing with a high-speed mixer and extrusion granulating. You can

[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

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29K 105: 12 C08L 61:06

Claims (2)

[Claims] 1. Phenolic resin 100 parts by weight, chopped strand glass fiber 75 to 260 parts by weight having a cut length of 0.5 to 12 mm, NBR 5 to 20 parts by weight, and a solvent of phenol resin having a boiling point of 60 ° C. or less 5 to 10 parts by weight. Parts are mixed with a high-speed mixer to make the glass fibers into single fibers to obtain a chip-like phenol resin / glass fiber mixture, and the mixture is further heated and kneaded to produce a phenol resin molding material. 2. The chip-like phenol resin / glass fiber blend is pelletized by a single-screw or twin-screw extruder granulator having L / D = 1 to 4, wherein the mixture is pelletized. Manufacturing method of phenol resin molding material.