JPH0611492B2 - Method for producing phenolic resin molding material - Google Patents

Description

The present invention relates to a method for producing a phenol resin molding material having excellent impact resistance, heat resistance and moisture resistance.

[Conventional technology]

Phenolic resins have excellent heat resistance and physical properties, and have been used as various industrial materials from the past.
In recent years, attempts have been made to resinize metal parts for the purpose of reducing the weight of various metal parts such as automobiles, or for the purpose of reducing the number of processing steps of metal parts and simplifying the process by integration.

In general, phenolic resin molding materials include wood powder as a filler,
Organic substances such as pulp and cloth, asbestos, calcium carbonate,
Inorganic substances such as mica, clay, talc, silica and glass fibers are used alone or in combination of two or more.

In particular, for parts that are required to have heat resistance, dimensional stability, and mechanical strength, a phenol resin molding material highly filled with an inorganic material has been used. Among them, phenol resin molding materials highly filled with glass fibers are excellent in high temperature strength, creep resistance, fatigue strength, dimensional stability and the like, and therefore, replacement of metal parts is progressing in some cases.

However, phenolic resins have the drawback of being hard and brittle due to their structure. For this reason, there is a problem that cracks are generated due to impact, and the application is limited at present.

On the other hand, since thermoplastic resins such as nylon, PBT, and PPS have excellent impact resistance, they do not have problems such as cracks due to impact, but have the drawback of low heat resistance.

Against this background, there has been a long-awaited development of a phenolic resin molding material that can achieve both heat resistance and impact resistance.

Phenolic resin molding material highly filled with glass fiber,
A mixture of kneader or Henschel mixer, etc., in which glass fibers are left as long fibers (for example, PG-123T manufactured by Nippon Oil Seal Co., Ltd.) is commercially available, but has a large dryness (dryness coefficient 5.4) injection molding, Transfer molding is not possible, high impact strength but low static strength,
There were some drawbacks such as dimensional change when heated. Also,
The material produced by a heat roll, an extruder, etc., has good injection moldability and dimensional stability, but the glass fiber is shear fractured, resulting in a short fiber length (50 to 500 μm length), and sufficient impact strength cannot be obtained. As a substitute material for a metal part that requires high reliability or high load, it has a drawback of poor reliability.

[Problems to be Solved by the Invention]

The present inventor has obtained a material capable of solving such a problem by blending glass fiber into a phenol resin composition produced in advance with a hot roll or an extruder, and heating it with a mixer with a lower shear such as a Henschel mixer. The present inventors have obtained the finding that the impact resistance can be improved without reducing the static strength by mixing, and based on this finding, various researches have been advanced to complete the present invention.

Its purpose is to have impact resistance and heat resistance,
It is to provide a method for producing a phenol resin molding material having excellent moldability.

[Means for Solving the Problems]

The present invention relates to a phenol resin composition 10 obtained by mixing and kneading a phenol resin, a reinforcing material, a curing agent, and other additives.
To 0 parts by weight, 4 to 30 parts by weight of 1.0 to 6.0 mm long glass fiber was added, and the temperature was 60 to 100 ° C with a stirrer having a heating mechanism and a rotating blade, and the peripheral speed of the rotating blade was 15 to 50 m / sec.
The method for producing a phenolic resin molding material is characterized by uniformly mixing and granulating under the conditions of.

Phenolic resin and reinforcing material used in the present invention, filler,
The phenol resin composition prepared by mixing and kneading a curing agent and other additives is produced by a kneader having a relatively high shearing force such as a hot roll or an extruder. In the case of using a kneader or a kneader with a relatively low shear such as a Henschel mixer, the adhesion between the resin and the filler becomes weak, and sufficient heat resistance (dimensions, creep, fatigue strength) cannot be obtained. Further, as the filler, an inorganic base material such as glass fiber, clay, mica or silica is desirable.

It is difficult to obtain heat resistance with organic equipment.

Further, the resin composition primarily kneaded in the present invention has a thickness of 500 μm.
The following particle sizes are preferred. When the particle size is adjusted to 500 μm or less, the resin composition melts well and the granulation property improves.

Next, in the present invention, glass fiber is added. The glass fiber used here has a length of 1.0 to 6.0 mm, and the amount thereof is 4 to 100 parts by weight of the phenol resin composition.
30 parts by weight. Impact resistance is insufficient with a short fiber of 1.0 mm or less or an addition amount of 4 parts by weight or less, and with a long fiber of 6.0 mm or more or an addition amount of 30 parts by weight or more, dryness becomes large and injection molding becomes difficult.

Further, in the present invention, the manufacturing method for uniformly mixing the phenol resin composition and the glass fiber is carried out by an agitator having a heating / cooling mechanism and a high-speed rotating blade. In simple mixing or mixing by a kneader, the glass fibers are entangled with each other, and the fibers become flocculated or the glass fibers remain in a bundled state, resulting in poor appearance of the molded product and variation in strength. Further, in the case of mixing with a kneader having a high shearing force such as a hot roll or an extruder, the glass fiber is sheared and broken, so that sufficient impact strength cannot be obtained.

The mixing conditions are a heating temperature of 60 to 100 ° C. and a rotary blade peripheral speed of 15 to 50 m / sec. If the heating temperature is 60 ° C or higher, the melting of the resin will be insufficient and uniform mixing will be difficult,
It is difficult to control the reaction of the resin at 100 ° C or higher. If the peripheral speed of the rotating blade is 15 m / sec or less, uniform mixing is difficult,
If it is / sec or more, the glass fiber is likely to be flocculated.

〔Example〕

 Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

"Part" indicates "part by weight".

Example 1 The following compounding composition was primarily kneaded and extruded with a twin-screw extruder, and pulverized to a particle size of 500 μm or less.

Resol type phenolic resin (softening point 65 ° C) 35 parts Glass fiber (1.5 mm length) 45 Firing clay 5 Curing aid 2 Release agent 2 Colorant 1 90 parts in total 3.0 parts length to 90 parts of this primary kneaded product Glass fiber 1
0 parts and a small amount of methanol are blended, a Hensche mixer (75) is used as a secondary kneader, and the tank temperature is 70 ° C.
The mixture was uniformly mixed and granulated under the condition that the peripheral speed of the rotary blade was 20 m / sec.

Comparative Example 1 A phenol resin molding material was obtained in the same manner as in Example 1 except that a kneader (125) was used as the primary kneader instead of the twin-screw extruder.

Comparative Example 2 A phenol resin molding material was obtained in the same manner as in Example 1 except that a hot roll (16 inches) was used as the secondary kneader instead of the Henschel mixer (without addition of methanol).

Comparative Example 3 Using the Henschel mixer (75), the following composition was uniformly mixed under the conditions of a bath temperature of 80 ° C. and a rotary blade peripheral speed of 20 m / sec to granulate.

Resol type phenolic resin (softening point 65 ° C) 35 parts Glass fiber (1.5 mm length) 45 Glass fiber (3.0 mm length) 10 Firing clay 5 Curing aid 2 Release agent 2 Colorant 1 Methanol (10) Total 100 Part Example 2 The following compounding composition was subjected to primary kneading with a hot roll (16 inches) and pulverized to a particle size of 500 μm or less.

Novolac type phenolic resin (softening point 95 ° C) 35 parts Glass fiber (1.5 mm length) 35 Hexamethylenetetramine 5 Curing aid 2 Release agent 2 Colorant 1 Total 80 parts 1.5 mm to 80 parts of this primary kneaded product Long glass fiber 2
0 parts and a small amount of methanol were blended, a Henschel mixer was used as a secondary kneader, and the mixture was uniformly mixed and granulated under the conditions of a tank temperature of 80 ° C. and a peripheral speed of a rotary blade of 40 m / sec.

Example 3 In Example 2, 1.5m as the glass fiber to be secondarily compounded
A phenol resin molding material was obtained in the same manner as in Example 2 except that the length of 3.0 mm was used instead of the length of m.

Comparative Example 4 In Example 2, the content of glass fiber having a length of 1.5 mm was reduced from 35 parts to 25 parts in the primary composition and 2 in the secondary composition.
A phenol resin molding material was obtained in the same manner as in Example 2 except that 0 part was increased to 30 parts.

Comparative Example 5 A phenol resin molding material was obtained in the same manner as in Example 2 except that the bath temperature was 40 ° C. in the Henschel mixer production conditions.

Comparative Example 6 A phenol resin molding material was obtained in the same manner as in Example 2, except that the rotating blade peripheral speed was set to 80 m / sec in the manufacturing conditions of the Henschel mixer.

The characteristics of the phenol resin molding materials obtained in the above Examples and Comparative Examples were measured according to JIS K-6911.

The results are shown in Table 1. In Comparative Examples 4, 5, and 6, flocculation was violent and granulation could not be performed.

As is clear from Table 1, the molding materials obtained in the examples have a low crawling coefficient and are well-balanced molding characteristics. In Comparative Example 1,
A kneader, which is a low shear kneader, was used as the primary kneader, but the dimensional stability, water resistance, etc. were poor. In Comparative Example 2,
A hot roll, which is a high-shear kneader, was used as the secondary kneader, but it is inferior in impact resistance. Comparative Example 3 shows that the crust-burden coefficient is slightly high and the formability is slightly inferior. The properties other than impact strength are also inferior.

Comparative Example 4 is a case where the blending amount of the glass fiber of the secondary blending is increased, and Comparative Examples 5 and 6 are the influences of the manufacturing conditions of the Henschel mixer. In both cases, the glass fiber is defibrated. However, since it becomes cotton-like, it cannot be made into a molding material.

〔The invention's effect〕

According to the method of the present invention, it is possible to obtain a molding material having a low crust-varying coefficient and an excellent molded product, and also to improve heat resistance, moisture resistance, and impact resistance which is a conventional defect without lowering. Therefore, it is suitable as an industrial method for producing a phenol resin molding material.

Therefore, the present invention can provide a material useful as a substitute material for metal parts such as automobiles.

Claims (1)

[Claims] 1. A phenol resin composition 10 prepared by blending a phenol resin, a reinforcing material, a filler, a curing agent and other additives and kneading them with a kneader having a high shearing force such as a hot roll or an extruder.
To 0 parts by weight, 4 to 30 parts by weight of glass fiber having a length of 1.0 to 6.0 mm was added, and the heating temperature was 60 to 100 ° C. and the peripheral speed of the rotating blade was 15 to 50 m / sec by an agitator having a heating mechanism and a rotating blade. A method for producing a phenol resin molding material, which comprises uniformly mixing and granulating under the conditions.