JP2003268197A - Phenolic resin molding composition for production of pulley made of the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic resin molding composition with improved mechanical strengths, and resistances to impact at elevated and lowered temperatures, belt impact and dust wear, and to provide pulleys produced by molding the composition. <P>SOLUTION: The phenolic resin molding composition comprises a resol type phenolic resin, a glass fiber, silica powder and a lubricant inorganic material. The composition preferably comprises 25-45 wt.% of the resol type phenolic resin, 35-60 wt.% of the glass fiber. 3-15 wt.% of the silica powder and 2-15 wt.% of the lubricant inorganic material of graphite or calcium fluoride. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a phenol resin molding material and a resin pulley.

[0002]

2. Description of the Related Art Phenolic resin molding materials require high reliability in terms of strength from familiar kitchen and lacquer ware products because they have excellent heat resistance and dimensional stability inherent in thermosetting resins and excellent moldability. It is used in a wide range of applications including automobile mechanical parts. In recent years, in particular, the application to alternative metal parts has been advanced for the purpose of weight reduction and cost reduction by integrating parts.

Resin pulleys are used in industrial machine parts, automobile parts, etc. because they are lighter in weight, lower in noise and lower in cost than metal pulleys. Among them, a phenol resin pulley formed by molding a phenol resin molding material is widely used because it has excellent dimensional accuracy and is less likely to be deformed than a thermoplastic resin pulley represented by nylon or the like. The pulley is required to have mechanical strength, dimensional stability, thermal shock resistance, belt attack resistance, and abrasion resistance of the pulley itself.
In particular, when used in an environment where sand dust is present, abrasion due to collision with sand dust is severe, so the pulley itself is required to have dust abrasion resistance, and it is necessary to balance these in a high dimension, but conventional phenol resin pulleys Has a problem in that these characteristics are inferior to those of metal pulleys.

In order to solve the above problems, in conventional molding materials for phenol resin pulleys, the mechanical strength has been improved by incorporating glass fibers. However, when glass fibers are incorporated, the elastic modulus is increased. It becomes higher and cracks are more likely to occur due to thermal shock. Therefore, the effect of improving the thermal shock resistance is obtained by blending the elastomer, but there is a problem in that the heat-induced strength decreases and the dimensional change increases due to heat generation during rotation. Furthermore, when used in an environment where sand dust exists, an inorganic powder base material such as glass beads, silica, or talc is blended to improve dust wear resistance. There is not only a problem such as a decrease in mechanical strength but also a problem that a mold and a molding machine are worn during molding. From the above points, phenolic resin pulleys used for industrial machine parts and automobile parts balance mechanical strength, dimensional stability, thermal shock resistance, belt attack resistance, and dust abrasion resistance in a higher dimension. That is the challenge.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a phenol resin molding material excellent in mechanical strength, thermal shock resistance, belt attack resistance and dust abrasion resistance, and A resin pulley formed by molding this is provided.

[0006]

This object is achieved by the present inventions (1) to (6) described below. (1) A phenol resin molding material comprising a resol-type phenol resin, glass fiber, silica powder, and a lubricating inorganic base material as essential components. (2) The phenol resin molding material as described in (1) above, which further contains polyvinyl acetal as an essential component. (3) Resol type phenolic resin 25 to 45% by weight, glass fiber 35 to 60% by weight, silica powder 3 to 15% by weight, and lubricating inorganic base material 2 to 15 with respect to the entire molding material.
The phenol resin molding material according to the above (1) or (2), in which the phenol resin molding material is blended in a weight percentage. (4) The phenol resin molding material as described in (3) above, which further comprises 1 to 3% by weight of polyvinyl acetal with respect to the entire molding material. (5) The phenol resin molding material according to any one of (1) to (4), wherein the lubricious inorganic base material is graphite or calcium fluoride. (6) A resin pulley formed by molding the phenol resin molding material according to any one of (1) to (5) above.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The phenol resin molding material (hereinafter referred to as "molding material") and the resin pulley of the present invention will be described in detail below. The molding material of the present invention is
It is characterized by containing a resol type phenol resin, glass fiber, silica powder, and a lubricating inorganic base material as essential components. The resin pulley of the present invention is formed by molding the phenol resin molding material. First,
The phenol resin molding material of the present invention will be described.

In the molding material of the present invention, a resol type phenol resin is used as the phenol resin. The reason for using the resol type phenolic resin is that the repeated thermal shock resistance required for resin pulleys is inferior to the repeated thermal shock resistance when the novolac type phenolic resin is not used in combination with the elastomer. This is because it is excellent in repeated thermal shock resistance even if it is not used. The amount of the resol-type phenol resin compounded is not particularly limited, but it may be 25 relative to the entire molding material.
It is preferably from 45 to 45% by weight, more preferably from 30 to 40% by weight. Thereby, the mechanical strength and the thermal shock resistance can be balanced. If the compounding amount is less than the lower limit value, the elastic modulus becomes high, and the tensile elongation also decreases, so the thermal shock resistance may decrease, or the resin content may decrease, resulting in a decrease in moldability. Further, when the blending amount exceeds the upper limit value, the mechanical strength, the deterioration of dust wear resistance and the thermal shock resistance due to the increase of the linear expansion coefficient decrease, or the dimensional change due to molding shrinkage increases, and the resin pulley As a result, satisfactory characteristics may not be obtained.

The molding material of the present invention contains glass fiber or silica powder as a filler. A common effect of blending these inorganic base materials is that the coefficient of thermal expansion of the inorganic base material is generally small, so that the dimensional stability of the molded product with respect to temperature changes is improved.

In the molding material of the present invention, the glass fiber is
In addition to the above effects, it is added to impart mechanical strength to the molded product. The glass fiber is not particularly limited, but preferably has a fiber diameter of 10 to 15 μm and a fiber length of 1 to 3 mm. As a result, the workability in the stage of forming a molding material and the mechanical strength of the obtained molded product can be improved. The blending amount of glass fiber is not particularly limited, but it is preferably 35 to 60% by weight based on the entire molding material. Thereby, the mechanical strength and the thermal shock resistance can be balanced. If the blending amount is less than the lower limit value, the mechanical strength may not be sufficient when a high load acts on the pulley. On the other hand, when the compounding amount exceeds the above upper limit, the elastic modulus becomes high and the tensile elongation also decreases, so that the thermal shock resistance may decrease and the workability at the time of manufacturing the molding material may decrease.

In the molding material of the present invention, the silica powder is mixed between the glass fibers in order to improve the dust abrasion resistance against sand dust and the like in addition to the above effects. The silica powder is not particularly limited, but the average particle size is preferably 5 to 50 μm. Particle size is 5
If it is less than μm, the silica powder dropped between the pulley and the belt may cause abrasion of the pulley itself and the belt, while if it exceeds 50 μm, the number of silica powder present in the molding material may decrease. As a result, the amount of silica powder present near the surface may decrease, and the dust wear resistance may decrease. The blending amount of silica powder is not particularly limited, but is preferably 3 to 15% by weight, and more preferably 3 to 10% by weight, based on the entire molding material. This makes it possible to balance the dust abrasion resistance and the mechanical strength. If the blending amount is less than the lower limit, the effect of suppressing the dust wear resistance may not be sufficient. On the other hand, when the amount exceeds the upper limit, the silica powder may lower the belt attack property and mechanical strength, or the mold and the molding device may be worn during molding.

The molding material of the present invention is characterized by containing a lubricious inorganic base material. This improves the lubricity between the pulley and the belt, improves the wear resistance of the pulley and the belt, and improves the dust wear resistance. In the present invention, the lubricious inorganic base material is an inorganic base material that has the effect of reducing the friction coefficient of the surface of the molded product by being mixed with the molding material. The lubricating inorganic base material is not particularly limited, but for example, graphite, molybdenum disulfide, tungsten dioxide, hexagonal boron nitride, talc,
Layered crystal substances such as mica and calcium fluoride, lead monoxide, graphite fluoride and the like can be mentioned. Among these, it is preferable to use graphite and calcium fluoride. As a result, the above effect can be provided at low cost. The graphite is not particularly limited, but it is preferable to use natural graphite. The blending amount of the lubricious inorganic base material is not particularly limited, but is 2 to 15% by weight based on the entire molding material
Is preferable, and more preferably 3 to 7% by weight.
Is. As a result, good lubricity and dust wear resistance can be imparted without affecting other properties. If the blending amount is less than the lower limit value, the effect of lubricity may not be sufficient, and wear characteristics and dust wear resistance may be deteriorated. On the other hand, if the upper limit is exceeded, the mechanical strength may decrease.

The molding material of the present invention is not particularly limited, but it is preferable to add polyvinyl acetal.
Thereby, the thermal shock resistance can be further improved. The polyvinyl acetal is not particularly limited, but includes polyvinyl formal, polyvinyl acetoacetal, polyvinyl butyral, and the like, and one or more of these may be used in combination. Since these polyvinyl acetals partially react with the resol-type phenolic resin, they exist in a form incorporated in the cross-linked structure of the resin, and therefore, they can be used in the conventionally used elastomers such as vinyl acetate, NBR and chloroprene rubber. Compared with such a structure having a sea-island structure which is independently dispersed in a cured resin system, the thermal shock resistance is improved by repeated thermal shock resistance with less deterioration due to peeling between the elastomer component and the resin interface. The blending amount of polyvinyl acetal is not particularly limited, but it is 1 with respect to the entire molding material.
It is preferably ˜3% by weight. Thereby, the thermal shock resistance of the molded product can be improved without affecting other characteristics. When the blending amount of polyvinyl acetal exceeds the above upper limit, swelling may occur at high temperature and mechanical strength may be reduced. If the blending amount is less than the lower limit value, the effect of imparting thermal shock resistance may not be sufficient.

In the molding material of the present invention, carbon fiber, carbon whiskers, potassium titanate whiskers, etc. as inorganic fibers, and calcium carbonate, clay, etc. as inorganic powders are blended as necessary with fillers other than the above. Good.

The phenolic resin molding material of the present invention is manufactured by a usual method. That is, in addition to the above raw materials, if necessary, a curing aid, a release agent, a pigment, a coupling agent, and the like are mixed and uniformly mixed, and then a roll, a co-kneader, a kneading machine such as a twin-screw extruder alone, or a roll. It is obtained by heating, melting and kneading in combination with another mixer, and then granulating or crushing.

Next, the resin pulley of the present invention will be described. The resin pulley of the present invention is obtained by molding the molding material. The phenol resin pulley of the present invention can be obtained by compression molding, transfer molding, injection molding or injection compression molding using a molding material having the above-mentioned composition, with a metal insert usually arranged in the center. The molding conditions are not particularly limited, but for example, when compression molding is used, the mold temperature is 170 to 190 ° C., and the molding pressure is 100.
It is desirable to carry out molding at a molding time of 3 to 7 minutes and a molding time of 150 kg / cm ² .

[0017]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples. 1. Manufacture of molding material The mixture mixed in the composition ratio shown in Table 1 was kneaded for 5 minutes with a heating mixing roll of different rotation speeds at 80 ° C,
The cooled sheet was crushed to obtain a granular phenol resin molding material. The formulations used in Examples and Comparative Examples are as follows. (1) Resol-type phenol resin: Resol-type phenol resin A obtained by the following production method and PR-51723 manufactured by Sumitomo Bakelite Co., Ltd. (number average molecular weight =
450) and 1: 1 were used. <Method for producing resol type phenol resin A> 100 kg of phenol (P), 62 kg of 87% by weight paraformaldehyde (F) (F / P molar ratio 1.70), 0.5 kg of zinc acetate are reflux condenser agitator, heating device, The mixture was placed in a 300-liter reaction kettle equipped with a vacuum dehydrator and a resin circulation device with a static mixer, and the reflux reaction was carried out for 3 hours. The phenol reaction rate at this point was 92%. After that, the mixture was heated to 115 ° C. while dehydrating, and the reaction was allowed to proceed at 115 ° C. and a vacuum degree of 100 Torr for 1 hour, then taken out on a cooling vat, and a resol-type phenol having a number average molecular weight of 700 in terms of phenol was 700. 105 kg of resin A was obtained. (2) PVB (polyvinyl butyral): Sekisui Chemical Co., Ltd., S-REC BX-5 (3) Graphite: Nishimura Graphite Co., Ltd., earthy graphite # 90 (4) Calcium fluoride: Morita Chemical Co., Ltd. (5) Talc : Made by Fuji Talc Industry Co., Ltd., average particle size 1
0μ (6) Glass fiber: Nippon Sheet Glass Co., Ltd. chopped strands, fiber diameter 11 μm, fiber length 3 mm (7) Silica powder 1: Denka Kogyo FB74, average particle size 30 μm (8) Silica powder 2: Admattec・ SO25R,
Average particle size 0.5 μm (9) Curing aid: slaked lime (10) Release agent: calcium stearate (11) Colorant: carbon black

2. Evaluation of Molding Material The molding materials obtained in Examples and Comparative Examples were evaluated. The molding method and evaluation method of the sample used for the characteristic evaluation are as follows. (1) Bending strength: A test piece was molded by transfer molding for 3 minutes with a mold heated to 175 ° C. This is JIS
The test was carried out according to K 6911. (2) Abrasivity: A test piece was molded by transfer molding for 3 minutes in a mold heated to 175 ° C. This is JIS
According to K7204, the load was 1000 Kgf, the rotation speed was 60 rpm, and the wear volume of the test piece after 1000 rotations with the wear wheel SC-17 used was evaluated. (3) Thermal shock resistance: inner diameter φ35 mm × outer diameter φ55 mm ×
A metal cylinder having a height of 20 mm was compression-molded at 175 ° C. for 3 minutes so as to be wrapped with a resin portion having a wall thickness of 3 mm. The heat cycle test in which this was alternately exposed from −40 ° C. to 120 ° C. for 30 minutes was repeated 1000 times, and the presence or absence of cracks was confirmed. When there were no cracks at all, it was rated as ◯, and when cracks were found, it was rated as x.

3. Manufacturing of Resin Pulleys Using the molding materials obtained in Examples and Comparative Examples, a pulley molded article having the shape shown in FIGS.
It was prepared by compression molding under the conditions of 5 ° C., curing time of 3 minutes and molding pressure of 150 kg / cm ² .

4. Evaluation of Resin Pulley (1) Belt Attack: Using the resin pulley, a belt mainly composed of ordinary rubber (26KD-9-1BAND)
ORIP-ACE 7PK95001-PXMF-1
9299-0000-T1 RG1600-140) was used to perform a motoring test at 5000 rpm for 500 hours. The belt aggressiveness was visually evaluated, and when belt wear was scarcely seen, it was rated as ◎, and when belt wear was seen but judged to be practically unproblematic, it was rated as clearly belt wear and practical When it was judged that there was a problem above, it was marked as x.

[0021]

[Table 1]

From the results shown in Table 1, all of Examples 1 to 9 are molding materials in which a predetermined amount of resol-type phenol resin, glass fiber, silica powder, and a lubricating inorganic base material are blended. The molded resin pulley has a high level of balance in mechanical strength, thermal shock resistance, belt attack resistance, and dust abrasion resistance. On the other hand, in Comparative Example 1, the novolac type phenol resin was used instead of the resol type phenol resin, but the thermal shock resistance decreased. In Comparative Example 2, since silica powder was not mixed, the belt aggressiveness was lowered. Further, in Comparative Examples 3 and 4, since no lubricating inorganic base material was blended, the belt aggressiveness was lowered.

[0023]

The present invention provides a resol type phenol resin,
A phenolic resin molding material characterized by containing glass fiber, silica powder, and a lubricating inorganic base material as essential components, and a resin pulley formed by molding the same. A resin pulley excellent in impact resistance, belt attack resistance and dust abrasion resistance can be obtained, and it can be applied to various pulleys used for industrial machine parts, automobile parts and the like.

[Brief description of drawings]

FIG. 1 is a plan view of pulleys molded in Examples and Comparative Examples.

FIG. 2 is a side sectional view of pulleys formed in Examples and Comparative Examples.

[Explanation of symbols]

1 pulley 2 Insert metal fittings

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 29/14 C08L 29/14 F16H 55/48 F16H 55/48 F term (reference) 3J031 AC10 BC05 CA03 4F071 AA41 AB03 AB15 AB26 AB28 AD01 AE11 AE17 AF14 AF22 AF23 AH07 AH17 BA01 BB03 BB05 BC07 4J002 CC041 DA028 DD038 DE098 DE158 DG028 DJ017 DJ048 DJ058 DK008 DL006 FA046 FD016 FD178 GM00 GN00

Claims (6)

[Claims] 1. A phenol resin molding material comprising a resol type phenol resin, glass fiber, silica powder, and a lubricating inorganic base material as essential components. 2. The phenol resin molding material according to claim 1, further comprising polyvinyl acetal as an essential component. 3. Resol type phenol resin 25 to 45% by weight, glass fiber 35 to 60% by weight, silica powder 3 to 15% by weight, and lubricating inorganic base material 2 to 15% by weight based on the whole molding material. The phenol resin molding material according to claim 1 or 2 to be blended. 4. The phenol resin molding material according to claim 3, further comprising 1 to 3% by weight of polyvinyl acetal with respect to the entire molding material. 5. The phenol resin molding material according to claim 1, wherein the lubricating inorganic base material is graphite or calcium fluoride. 6. A resin pulley formed by molding the phenol resin molding material according to any one of claims 1 to 5.