JP2011068705A - Phenolic resin molding material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic resin molding material which can provide a molded article excellent in dimensional accuracy and dimensional stability with heat resistance and moisture resistance. <P>SOLUTION: The phenolic resin molding material including: (A) novolac-type phenolic resin including alkylbenzene-modified novolac-type phenolic resin; (B) resol-type phenolic resin; (C) hexamethylenetetramine; (D) glass fibers; (E) wollastonite; and (F) silica, is characterized in that, based on the total weight of the molding material, the total content of the (A), (B) and (C) components is 15-30 wt.%, the content of the (D) component is 10-20 wt.%, the content of the (E) component is 30-50 wt.%, and the content of the (F) component is 15-35 wt.%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a phenol resin molding material.

  Mechanical parts used in automobiles and the like are required to have heat resistance, high strength, moldability, and the like due to the usage environment. Conventionally, ceramic or metal parts have been mainly used to satisfy these characteristics. Moreover, when using a plastic from such required characteristics, a phenol resin molding material is often used. The mechanical parts made of ceramic or metal have problems that the weight of the individual is large, the processing takes time, and the cost is high. On the other hand, the molded product of the phenol resin molding material has a large merit for use because it is small in weight and excellent in heat resistance. In order to impart such characteristics, conventionally, glass fiber, fused silica, or the like has been used as a compounding filler.

  However, dimensional variations occur in molded products using such phenolic resin molding materials, and for applications that require dimensional accuracy, the dimensions do not fall within tolerances, resulting in a decrease in yield. It has become. In order to compensate for this, precise post-processing is applied, but recently, in order to reduce product costs, there is a need to improve product yield and reduce post-processing steps, and to improve the dimensional accuracy of molded products. Has been required. For this reason, examination by precision molding has been made, but there is a limit to suppress variation in dimensions, and it has not led to improvement of product yield and reduction of post-processing steps. Furthermore, if the precision mechanism component absorbs moisture during storage and swells, or if it heat shrinks during use at high temperatures such as inside an engine, it may cause malfunction due to changes in dimensions. Therefore, dimensional stability under high temperature and high humidity has also been required at the same time. That is, there is a demand for a phenolic resin molding material that satisfies both the dimensional accuracy of the molded product and the heat and moisture resistance dimensional stability.

  On the other hand, a technique for improving dimensional accuracy by adding talc or clay to a phenol resin molding material is disclosed in Patent Document 1, for example, but further improvement is required to improve dimensional stability. It was.

  In addition, as a technology to reduce the heat-resistant dimensional change, examples achieved by blending many inorganic base materials in phenol resin molding materials can be seen, but these are molded by blending many inorganic base materials. There is a problem with stability and dimensional accuracy is not compatible.

  Furthermore, a technique for reducing the moisture-resistant dimensional change by including an alkylbenzene-modified novolak-type phenol resin as a part of the phenol resin is disclosed in, for example, Patent Document 2, but further improvement is required to improve dimensional accuracy. Was needed.

Japanese Patent Laid-Open No. 06-192544 JP 2004-269762 A

  The present invention provides a phenolic resin molding material capable of obtaining a molded product having excellent dimensional accuracy and heat / humidity dimensional stability.

[1] (A) novolak type phenolic resin including alkylbenzene modified novolak type phenolic resin, (B) resol type phenolic resin, (C) hexamethylenetetramine, (D) glass fiber, (E) wollastonite, and ( F) A phenol resin molding material containing silica,
The total content of the molding materials is 15 to 30% by weight of the components (A), (B), and (C), 10 to 20% by weight of the (D) component, and 30 to 50 of the (E) component. A phenol resin molding material, wherein the component (F) is 15 to 35% by weight.
[2] The above [1], wherein the content of the alkylbenzene-modified novolak phenol resin in the component (A) is 5 to 15% by weight based on the total of the components (A), (B), and (C). 2. A phenolic resin molding material described in 1.
[3] The phenol resin molding according to the above [1] or [2], wherein the weight ratio of the component (A) to the component (B) is (A) :( B) = 6-12: 4-8. material.

  The phenolic resin molding material of the present invention can provide a molded product having superior dimensional accuracy, heat resistance and moisture resistance dimensional stability compared to conventional phenolic resin molding materials, and automobile parts (various motor gear cases, motor brush holders, It is suitably used for motor related parts such as various bushes), various gear parts, hydraulic valve parts and the like.

The phenol resin molding material of the present invention (hereinafter sometimes simply referred to as “molding material”) will be described in detail below.
The molding material of the present invention is
(A) novolak type phenolic resin containing alkylbenzene modified novolak type phenolic resin, (B) resol type phenolic resin, (C) hexamethylenetetramine, (D) glass fiber, (E) wollastonite, and (F) silica A phenolic resin molding material containing
The total content of the molding materials is 15 to 30% by weight of the components (A), (B), and (C), 10 to 20% by weight of the (D) component, and 30 to 50 of the (E) component. % By weight and component (F) is 15 to 35% by weight.

  The molding material of this invention contains the novolak-type phenol resin containing (A) alkylbenzene modified novolak-type phenol resin.

The alkylbenzene-modified novolak type phenol resin in the component (A) is a product in which alkylbenzenes such as xylene and toluene are bonded to the novolak type phenol resin by a methylene bond or the like.
The method for producing such an alkylbenzene-modified novolak type phenol resin is not particularly limited. For example, an alkylbenzene resin is produced by reacting alkylbenzene and formaldehyde in the presence of an acidic catalyst, and this is reacted in the presence of an acidic catalyst. It can be produced by reacting with phenols or phenols and aldehydes.

Although it does not specifically limit as phenols used here, For example, phenol, o-cresol, m-cresol, p-cresol, xylenol, alkylphenols, catechol, resorcin, etc. are mentioned. These can be used alone or in admixture of two or more.
The aldehydes are not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, benzaldehyde, substances that generate these aldehydes, solutions of these aldehydes, and the like. A mixture of seeds or more can be used.

  Examples of the alkylbenzene-modified novolak-type phenol resin thus obtained include xylene-modified novolak-type phenol resins and toluene-modified novolak-type phenol resins.

  In the molding material of this invention, the heat resistance and moisture resistance of the molded article formed by shape | molding the molding material of this invention can be improved by containing this alkylbenzene modified novolak-type phenol resin.

In the molding material of the present invention, the content of the alkylbenzene-modified novolak type phenol resin is preferably 5 to 15% by weight based on the total of the components (A), (B), and (C).
By setting the content of the alkylbenzene-modified novolak type phenolic resin to the above lower limit value or more, it is possible to obtain a material having a small change in moisture resistance and to obtain a material having good dimensional accuracy by setting the content to the upper limit value or less. Can do.

In the molding material of this invention, the novolak-type phenol resin which is not an alkylbenzene modified novolak-type phenol resin can be contained as said (A) component.
As such a novolak type phenol resin, phenols and aldehydes are usually added in the presence of an acidic catalyst, and the molar ratio of aldehydes to phenols (aldehydes / phenols) is 0.7 to 0.9. What was obtained by making it react as can be used.

Although it does not specifically limit as phenols used here, For example, phenol, o-cresol, m-cresol, p-cresol, xylenol, alkylphenols, catechol, resorcin, etc. are mentioned. These can be used alone or in admixture of two or more.
The aldehydes are not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, benzaldehyde, substances that generate these aldehydes, solutions of these aldehydes, and the like. A mixture of seeds or more can be used.

The number average molecular weight of the novolac type phenol resin is preferably 500 to 1,000.
By making the number average molecular weight not more than the above upper limit value, good workability can be ensured at the time of molding material production. On the other hand, by setting the number average molecular weight to the above lower limit value or more, the molding cycle when molding the molding material can be shortened.

  In the molding material of this invention, the manufacturing cost of a molding material can be reduced by using the said novolak-type phenol resin.

The molding material of the present invention contains (B) a resol type phenol resin.
As the above-mentioned resol type phenolic resin, phenols and aldehydes are usually used in the presence of a basic catalyst, and the molar ratio of aldehydes to phenols (aldehydes / phenols) is set to 1.3 to 1.7. What was obtained by making it react can be used.

Although it does not specifically limit as phenols used here, For example, phenol, o-cresol, m-cresol, p-cresol, xylenol, alkylphenols, catechol, resorcin, etc. are mentioned. These can be used alone or in admixture of two or more.
The aldehydes are not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, benzaldehyde, substances that generate these aldehydes, solutions of these aldehydes, and the like. A mixture of seeds or more can be used.

  In the molding material of the present invention, the combined use of (A) a novolak type phenolic resin containing an alkylbenzene-modified novolak type phenolic resin and (B) a resol type phenolic resin improves the toughness of the molded product and increases the mechanical strength. Can be increased.

In the molding material of the present invention, the weight ratio of (A) a novolac type phenol resin containing an alkylbenzene-modified novolac type phenol resin to (B) a resol type phenol resin is (A) :( B) = 6 to 12: 4. It is preferably ˜8. More preferably, it is 7-11: 5-7.
By setting the ratio between the two in the above range, the toughness, cost, and heat / humidity dimensional changes of a molded product formed by molding the molding material of the present invention can be brought to suitable levels.

The molding material of the present invention contains (C) hexamethylenetetramine. The component (C) acts as a curing agent for the component (A) together with the component (B).
Although the compounding quantity of the said (C) component is not specifically limited, For example, 30-40 weight part can be mix | blended with respect to 100 weight part of the said (A) component.
In the molding material of this invention, what acts as a hardening | curing agent of the said (A) component other than the said (C) component and (B) component can be used together.

In the molding material of the present invention, the total content of the components (A), (B), and (C) is 15 to 30% by weight with respect to the entire molding material. More preferably, it is 17 to 25% by weight.
By making content of the said component more than the said lower limit, favorable workability | operativity can be ensured at the time of molding material manufacture.
On the other hand, by setting the content to be equal to or less than the above upper limit value, the dimensional change due to molding shrinkage during molding can be reduced, and the dimensional accuracy can be improved. In addition, the dimensional change in heat and moisture resistance can be reduced.

The molding material of this invention contains (D) glass fiber. Thereby, high mechanical strength can be imparted to the molded product.
Although it does not specifically limit about glass fiber, It is preferable to use what has a fiber diameter of 10-15 micrometers and a fiber length of 1-3 mm. Thereby, it is possible to further improve the workability at the stage of forming the molding material and the mechanical strength of the obtained molded product.

The compounding quantity of the said glass fiber is 10 to 20 weight% with respect to the whole molding material. Preferably it is 12-18 weight%.
By setting the blending amount of the glass fiber to the above lower limit or more, it is possible to secure sufficient toughness and improve the mechanical strength by setting the elastic modulus and elongation of the molded product to suitable levels. On the other hand, by setting the blending amount to the upper limit value or less, it is possible to reduce the dimensional anisotropic difference due to the orientation of the glass fiber and improve the dimensional accuracy of the molded product. Moreover, the workability at the time of manufacturing the molding material can be improved.

The molding material of the present invention contains (E) wollastonite. Thereby, mechanical strength and dimensional accuracy can be imparted to the molded product.
The compounding quantity of the said wollastonite is 30 to 50 weight% with respect to the whole molding material. Preferably it is 35 to 45% by weight.
By setting the blending amount of wollastonite to the above lower limit or higher, the bending strength and tensile strength of the molded product can be improved. Further, the linear expansion coefficient can be suppressed and the dimensional accuracy can be improved. On the other hand, workability at the time of manufacturing the molding material can be improved by setting the blending amount to the upper limit value or less.

The molding material of the present invention contains (F) silica. Thereby, the dimensional accuracy of a molded product can be improved.
The blending amount of the silica is 15 to 35% by weight with respect to the entire molding material. Preferably it is 20-30 weight%.
By making the compounding quantity of silica more than the said lower limit, the dimensional accuracy and external appearance of a molded product can be improved. On the other hand, workability at the time of manufacturing the molding material can be improved by setting the blending amount to the upper limit value or less.

The molding material of the present invention uses an alkylbenzene-modified novolac type phenol resin as one of the phenol resin components. Thereby, the moisture-proof dimension change of a molded article can be suppressed.
Moreover, the molding material of this invention has few total content of the phenol resin component and hexamethylenetetramine with respect to the whole molding material compared with the normal phenol resin molding material. Thereby, the dimensional accuracy of a molded product can be improved.
And the molding material of this invention uses glass fiber, a wollastonite, and a silica as an inorganic filler. Glass fiber and wollastonite can impart mechanical strength to the molded product, and wollastonite and silica can impart dimensional accuracy to the molded product.
In this way, the present invention not only has the effect that each component has alone, but also has a balanced effect on the dimensional accuracy, heat resistance and moisture resistance dimensional stability of the molded product due to the synergistic effect by using each component in combination in an appropriate amount. It was possible to provide a molding material that can be expressed in a compatible manner.

  The molding material of the present invention may optionally contain various additives used in ordinary thermosetting resin molding materials, for example, a curing agent or a release catalyst such as a curing catalyst, stearic acid, zinc stearate, or calcium stearate, An adhesion improver for improving the adhesion between the filler and the thermosetting resin, or a coupling agent, a coloring pigment, a coloring dye, a solvent, or the like can be blended.

  The molding material of this invention is manufactured by a normal method. For example, in addition to the above raw materials, if necessary, a filler, a curing aid, a release agent, a pigment, a coupling agent, and the like are blended and uniformly mixed, and then a kneading apparatus such as a roll, a kneader, or a twin screw extruder alone. Alternatively, it may be obtained by granulation or pulverization after heating and melt-kneading with a combination of a roll and another mixing device.

The molding using the molding material of the present invention is suitable for injection molding, but is not particularly limited, and other methods such as transfer molding, compression molding, and injection compression molding can be used.
Although it does not specifically limit as molding conditions, For example, when using injection molding, it can shape | mold by mold temperature 170-190 degreeC, shaping | molding pressure 100-150 MPa, and curing time 30-90 second.

  Hereinafter, the present invention will be described with reference to examples and comparative examples.

1. Manufacture of molding material The material mixture mix | blended with the ratio (weight%) shown in Table 1 was knead | mixed with the heating roll from which rotational speed differs, and what was cooled in the sheet form was grind | pulverized, and the granular molding material was obtained. Table 1 shows the workability when manufacturing the molding material and the evaluation results of the characteristics of the molded product using the molding material.
The kneading conditions of the heating roll were such that the rotation speed was high speed / low speed = 20 rpm / 14 rpm, the temperature was high speed / low speed = 80 ° C./20° C., and the kneading time was 3 to 5 minutes.

Each compound used in Examples and Comparative Examples is as follows.
(1) Alkylbenzene-modified novolak-type phenolic resin (xylene-modified novolak-type phenolic resin): “PR-51992” manufactured by Sumitomo Bakelite Co., Ltd.
(2) Novolac type phenolic resin (number average molecular weight 700): “A-1077P” manufactured by Sumitomo Bakelite Co., Ltd.
(3) Resol type phenol resin (number average molecular weight 700): “R-25” manufactured by Sumitomo Bakelite Co., Ltd.
(4) Hexamethylenetetramine: CHANG CHUN PETROCHEMICAL. CO. "HEXAMINE" made by LTD
(5) Glass fiber: Glass chopped strand “CS3E479FB” manufactured by Nittobo Co., Ltd. (6) Wollastonite: “NYAD325” manufactured by NYCO
(7) Silica (fused silica): “SIDISTAR” manufactured by ELKEM
(8) Curing aid (magnesium oxide): “Kyowa Mag 30” manufactured by Kyowa Chemical Industry Co., Ltd.
(9) Colorant (carbon black): “Carbon Black # 750B” manufactured by Mitsubishi Chemical Corporation
(10) Mold release agent (stearic acid): “Stearic acid cherry” manufactured by NOF Corporation
(11) Release agent (calcium stearate): “Ca-St” manufactured by Nitto Kasei Kogyo Co., Ltd.
Among the above, the release agent was used by mixing (10) and (11) at a ratio of 1: 1.

The molding method and evaluation method of the test piece used for the characteristic evaluation are as follows.
(1) Bending strength: Using the molding material obtained above, a test piece was prepared by transfer molding (mold temperature: 175 ° C., curing time: 3 minutes), and was performed according to JIS K 6911.
(2) Dimensional accuracy: Using the molding material obtained above, a test piece having a cylindrical shape with an outer diameter of 40 mm, an inner diameter of 34 mm, and a thickness of 3 mm is produced by injection molding (mold temperature: 175 ° C., curing time: 25 seconds). Then, the inner diameter of the cylinder was measured (n = 18), and 8σ was obtained from the standard deviation σ.
(3) Dimensional change rate: Using the molding material obtained above, a disk-shaped test piece of φ50 mm × thickness 3 mm was prepared by transfer molding (mold temperature 175 ° C., curing time 3 minutes), and a 150 ° C. constant temperature bath, And the dimension of the disk diameter direction after each 1000-hour immersion in a 49 degreeC x 85RH% constant temperature and humidity chamber was measured. Table 1 shows the dimensional change rate based on the dimensions without immersion.
(4) Workability: Workability at the time of manufacturing the molding material was confirmed. The symbols are as follows.
○: Good ×: Cured while roll kneading is insufficient, and the compound does not disperse uniformly due to insufficient kneading

From the results of Table 1, Examples 1 to 3 were all molding materials of the present invention, and were excellent in dimensional accuracy, heat and moisture resistance dimensional stability, and in workability.
Since the molding material of Comparative Example 1 did not contain an alkylbenzene-modified novolak type phenol resin, the heat and moisture resistance dimensional stability was lowered.
Since the molding material of Comparative Example 2 had a large total amount of the components (A) to (C), the dimensional accuracy and the heat and moisture resistance dimensional stability were lowered.
Since the molding material of Comparative Example 3 had a small total amount of the components (A) to (C), workability was lowered.
Since the molding material of Comparative Example 4 had a large amount of glass fiber, the dimensional accuracy was lowered.
Since the molding material of Comparative Example 5 had a small amount of glass fiber, the bending strength was lowered.

  The phenol resin molding material of the present invention can balance dimensional accuracy and heat / humidity dimensional stability at a higher level, and various products such as phenolic resin hydraulic valve parts used in industrial machine parts and automobile parts. Also, it can be suitably used.

Claims (3)

(A) novolak type phenolic resin containing alkylbenzene modified novolak type phenolic resin, (B) resol type phenolic resin, (C) hexamethylenetetramine, (D) glass fiber, (E) wollastonite, and (F) silica A phenolic resin molding material containing
The total content of the molding material is such that the total of the components (A), (B), and (C) is 15 to 30% by weight, the component (D) is 10 to 20% by weight, and the component (E) is 30 to 50%. A phenol resin molding material, wherein the component (F) is 15 to 35% by weight.   2. The phenol according to claim 1, wherein the content of the alkylbenzene-modified novolak type phenol resin in the component (A) is 5 to 15 wt% with respect to the total of the components (A), (B), and (C). Resin molding material.   The phenol resin molding material according to claim 1 or 2, wherein a weight ratio of the component (A) to the component (B) is (A) :( B) = 6-12: 4-8.