JP5934937B2 - Phenolic resin molding materials and molded products using the same - Google Patents

Description

  The present invention relates to a phenol resin molding material and a molded article using the same.

  Conventionally, many metal parts have been used for sliding parts of automobiles, electric machines, and machines. However, replacement with resin parts is being studied in response to demands for weight reduction and productivity improvement.

  Such machine parts are required to have heat resistance, mechanical strength, chemical resistance, etc., and therefore thermosetting resins are suitable.

  Among them, phenol resin molding materials are excellent in heat resistance, mechanical strength, and dimensional stability, and are therefore used as an alternative material for metal parts used in automobiles and other general-purpose engines.

  In recent years, some of these require high sliding characteristics. Phenolic resin molding materials that require sliding properties are known to be composed of phenolic resin, glass fiber, and other additives, but in order to meet the requirements for high sliding properties, lubrication substances are added. Thus, a method for improving the sliding characteristics has been proposed.

  For example, a method of adding a thermoplastic resin such as high molecular weight polyethylene or polytetrafluoroethylene as a lubricating substance has been proposed (Patent Documents 1 to 3).

  In addition to the method of adding a lubricating substance, a method of improving sliding properties by using carbon fiber or aramid fiber instead of glass fiber has been studied.

JP-A-4-103654 JP 2011-089095 A JP 09-176450 A

  However, the above-mentioned thermoplastic resin used as a lubricating substance has low polarity and poor compatibility with the phenol resin, so that the dispersibility is lowered and the strength may be significantly reduced. It was limited.

  Further, the method using carbon fiber or aramid fiber has a problem in that since these fibers are very expensive, the materials using them are also expensive, and the cost performance is low.

  The present invention has been made in view of the circumstances as described above, a phenol resin molding material having a small decrease in mechanical strength, excellent sliding characteristics, and excellent cost performance, and a molded product using the same. The issue is to provide.

  In order to solve the above problems, the phenol resin molding material of the present invention is a phenol resin molding material containing a phenol resin, a fiber reinforcing material, and a lubricating substance, and has a hydroxyl group and a carboxyl group on the surface as the lubricating substance. It is characterized by containing polyethylene particles introduced.

  In this phenol resin molding material, the content of polyethylene particles having hydroxyl groups and carboxyl groups introduced therein is preferably in the range of 1 to 8% by mass relative to the total amount of the phenol resin molding material.

  In this phenol resin molding material, it is preferable that the weight average molecular weight of the polyethylene particles into which hydroxyl groups and carboxyl groups are introduced is in the range of 100,000 to 5,000,000.

  In this phenol resin molding material, it is preferable that the average particle diameter of the polyethylene particles into which hydroxyl groups and carboxyl groups are introduced is in the range of 5 to 350 μm.

  The molded article of the present invention is characterized by being formed of a cured product of the above-described phenol resin molding material.

  According to the phenol resin molding material and the molded product of the present invention, the decrease in mechanical strength is small, the sliding property is excellent, and the cost performance is also excellent.

  The present invention is described in detail below.

  In the phenol resin molding material of the present invention, as the phenol resin, a novolac type phenol resin and a resol type phenol resin can be used alone, or these can be used in combination.

  Although content of a phenol resin is not specifically limited, The inside of the range of 25-40 mass% is preferable with respect to the whole quantity of a phenol resin molding material, and the inside of the range of 30-38 mass% is more preferable. If the content of the phenolic resin is within this range, kneadability and moldability can be improved, and the dimensional change after moisture-resistant treatment is suppressed by reducing the molding shrinkage rate and linear expansion coefficient, and good dimensional stability. Sex can be obtained.

  Although it does not specifically limit as a novolak type phenol resin, It is preferable that the weight average molecular weight of polystyrene conversion by GPC (gel permeation chromatography) exists in the range of 2000-6000. When the weight average molecular weight is within this range, a decrease in handleability due to a low molecular weight component is suppressed, and fluidity during molding is also good.

  The novolac type phenol resin preferably has an ortho / para ratio (O / P ratio) in the range of 0.8 to 6.0. When the O / P ratio is within this range, the curability can be improved.

Here, the O / P ratio is defined as follows. The novolac type phenol resin has a structure in which an aromatic ring derived from a phenol compound is cross-linked by a methylene bond. And the way of cross-linking of the methylene bond is when the ortho-position is cross-linked with respect to the hydroxyl group of each aromatic ring, when the ortho-position and the para-position are cross-linked, and the para-position is cross-linked There are three cases. Thus, the O / P ratio is expressed by the following equation.
O / P ratio = {(number of methylene bonds bridged between ortho positions) + (1/2 of the number of methylene bonds bridged between ortho positions and para positions)} / {bridged between para positions Number of methylene bonds + 1/2 of the number of methylene bonds bridging at ortho and para positions}
In addition, the number of methylene bonds of the novolac-type phenol resin and the bond form thereof can be determined by methods such as infrared absorption spectrum, nuclear magnetic resonance spectrum, and GPC. For example, each absorption position and absorption intensity can be confirmed in advance by these methods using a standard substance in which the number of methylene bonds and the bond form thereof have been identified, and can be determined from the absorption position and absorption intensity.

  Although it does not specifically limit as a resol type phenol resin, For example, a methylol type, a dimethylene ether type, etc. can be used. Among them, the dimethylene ether type has a good balance between curability and thermal stability.

  Although the weight average molecular weight of a resol type phenol resin is not specifically limited, It is preferable to exist in the range of 2000-6000 in polystyrene conversion by GPC. When the weight average molecular weight is within this range, a decrease in handleability due to a low molecular weight component is suppressed, and fluidity during molding is also good.

  The phenol resin molding material of the present invention may contain a phenol resin curing agent. As such a curing agent, for example, a nitrogen compound such as hexamethylenetetramine can be used, which is suitable when a novolac type phenol resin is used as the phenol resin.

  Although content of the hexamethylenetetramine as a hardening | curing agent is not specifically limited, The inside of the range of 10-25 mass% with respect to a novolak-type phenol resin is preferable. When the content of hexamethylenetetramine is within this range, the curability can be improved and the cross-linking density of the cured product can be within an appropriate range.

  The phenol resin molding material of the present invention can contain a curing aid for improving curability. As the curing aid, for example, metal oxides, metal hydroxides, boric acid, amine compounds, imidazole compounds and the like can be used.

  As the metal oxide, for example, calcium oxide, cobalt oxide, magnesium oxide, iron oxide, or the like can be used.

  As the metal hydroxide, for example, calcium hydroxide can be used.

  Examples of the amine compound include ethylenediamine, diethylenetriamine, triethylenetetramine, 4,4-diaminodiphenylmethane, metaphenylenediamine, diaminodiphenylsulfone, benzyldimethylamine, and 1,8-diazabicyclo (5,4,0) undecene. be able to.

  As the imidazole compound, for example, 2-methylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole and the like can be used.

  Although content of a hardening adjuvant is not specifically limited, The inside of the range of 0.5-5.0 mass% is preferable with respect to the whole quantity of a phenol resin. When the content of the curing aid is within this range, it is possible to accelerate the curing of the phenolic resin and to suppress the manufacturability and moldability due to the too high curing speed.

  A fiber reinforcing material is blended in the phenol resin molding material of the present invention. As the fiber reinforcing material, glass fiber is preferable. Although glass fiber is not specifically limited, For example, glass fiber which consists of A-glass, C-glass, D-glass, E-glass, R-glass, S-glass, T-glass, AR-glass etc. should be used. Can do.

  Although the fiber diameter of glass fiber is not specifically limited, The inside of the range of 8-18 micrometers is preferable. The fiber length is not particularly limited, but is preferably in the range of 1 to 5 mm. When the fiber diameter and fiber length are within this range, workability during preparation of the phenol resin molding material is good, and the strength of the molded product can be increased.

  Although content of glass fiber is not specifically limited, 40-65 mass% is preferable with respect to the whole quantity of a phenol resin molding material. When the content of the glass fiber is within this range, sufficient mechanical strength of the molded product can be obtained, and deterioration of manufacturability and moldability can be suppressed.

  In the phenol resin molding material of the present invention, an inorganic mineral can also be used as a reinforcing material together with the fiber reinforcing material. As such an inorganic mineral, for example, wollastonite, calcium carbonate, talc, fired clay, unfired clay, mica, glass beads, alumina, and the like can be used.

  In the phenol resin molding material of the present invention, polyethylene particles having a hydroxyl group and a carboxyl group introduced on the surface (hereinafter, also referred to as “surface-treated polyethylene particles”) are blended as a lubricating substance.

  By blending the surface-treated polyethylene particles, it is possible to enhance the sliding characteristics while suppressing a decrease in mechanical strength of the molded product. Since the polyethylene particles having no hydroxyl group or carboxyl group on the surface are non-polar, the compatibility with the polar phenol resin is poor and the dispersibility is lowered. Therefore, the sliding characteristics cannot be sufficiently exhibited. On the other hand, since the polyethylene particle which introduce | transduced into the surface the hydroxyl group and carboxyl group which are polar groups becomes high polarity, compatibility with a phenol resin becomes high and dispersibility improves. As a result, excellent sliding characteristics can be exhibited.

  The surface-treated polyethylene particles are obtained by introducing a hydroxyl group and a carboxyl group on the surface by a surface treatment technique using an oxidizing gas. For example, the “Ingens” series (manufacturer: Fluoroseal Co., Ltd.) can be used. The ratio of the hydroxyl group to the carboxyl group in the surface-treated polyethylene particles is not particularly limited, but is preferably 1: 9 to 9: 1.

  The weight average molecular weight of the surface-treated polyethylene particles is not particularly limited, but is preferably in the range of 100,000 to 5000000. When the weight average molecular weight of the surface-treated polyethylene particles is within this range, excellent sliding characteristics can be exhibited.

  Here, the weight average molecular weight of the surface-treated polyethylene particles can be measured by GPC according to the following method. As the GPC apparatus, Waters GPC 150C ALC / GPC is used. The column is measured using one SHODEX GPCUT802.5 and two UT806M, and a differential refractometer (RI detector) as a detector. The measurement solvent is o-dichlorobenzene and the column temperature is set to 145 ° C. The sample concentration is 1.0 mg / ml, and 200 microliters are injected for measurement. A calibration curve of molecular weight is prepared using a polystyrene sample having a known molecular weight by the universal calibration method.

  The average particle diameter of the surface-treated polyethylene particles is not particularly limited, but is preferably in the range of 5 to 350 μm, and more preferably in the range of 10 to 300 μm. When the average particle diameter of the surface-treated polyethylene particles is within this range, the cost performance is excellent and excellent sliding characteristics can be exhibited.

The average particle diameter can be measured by a laser diffraction / scattering method. Specifically, the particle size distribution is created on a volume basis by a laser diffraction particle size distribution measuring device, and the median diameter (d ₅₀ ) is measured. This median diameter can be taken as the average particle diameter.

  The content of the surface-treated polyethylene particles is preferably in the range of 1 to 8% by mass with respect to the total amount of the phenol resin molding material. When the content of the surface-treated polyethylene particles is within this range, the decrease in mechanical strength is small, the sliding properties are excellent, and the cost performance is also excellent.

  In the phenol resin molding material of the present invention, other additives can be blended in addition to the above-described components within a range not impairing the effects of the present invention. As such an additive, a mold release agent, a coloring agent, a coupling agent, etc. can be used, for example.

  As the mold release agent, for example, stearates such as calcium stearate, magnesium stearate and magnesium stearate, carnauba wax and the like can be used.

  As the colorant, for example, titanium oxide, bengara, carbon black, molybdenum red, phthalocyanine blue, or the like can be used.

  As a coupling agent, a silane coupling agent, a titanate coupling agent, etc. can be used, for example.

  The phenol resin molding material of the present invention can be prepared by kneading the above-mentioned phenol resin, fiber reinforcing material, lubricating material, etc. using a biaxial kneader or the like. After kneading, it may be cooled and pulverized and granulated.

  A molded article can be obtained by performing heat and pressure molding such as injection molding, direct pressure molding, transfer molding, etc. using the phenol resin molding material of the present invention thus prepared.

  The molded product of the present invention is suitable for sliding parts such as automobile engine room peripheral parts because the mechanical strength is small, sliding characteristics are excellent, and cost performance is excellent. Can do.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

The following ingredients were used as blending components.
(Phenolic resin)
・ Novolak type phenol resin, “PAR” manufactured by Panasonic Corporation, weight average molecular weight 3000, O / P ratio = 1.0
・ Resol type phenol resin, “AX-10” manufactured by Panasonic Corporation, weight average molecular weight 3000, dimethylene ether type (curing agent)
Hexamethylenetetramine (lubricating substance)
-Polyethylene particles into which hydroxyl groups and carboxyl groups have been introduced by surface treatment, distributor: Yoko Hiraizumi Co., Ltd., manufacturer: Fluorseal Co., Ltd., “Ingens UH, HD” series, weight average molecular weight 3000000 and average particle diameters 20 μm, 30 μm, 45 μm , 180 μm, weight average molecular weight 100,000 and average particle diameter 20 μm
Polyethylene particles (no surface treatment), “Miperon XM-220” manufactured by Mitsui Chemicals, Inc., weight average molecular weight 3000000, average particle diameter 30 μm
(Curing aid)
Calcium hydroxide (release agent)
Carnauba wax (pigment)
Carbon black (fiber reinforcement)
Glass fiber, “CS3E-479S” manufactured by Nitto Boseki Co., Ltd., fiber diameter 12 μm, fiber length 3 mm
Predetermined amounts of the above ingredients were mixed as shown in Table 1 and mixed for 1 minute. Next, this mixture was kneaded at a product temperature of 100 to 110 ° C. for 3 minutes with a twin-screw kneader. Thereafter, the kneaded product was cooled and pulverized and granulated to obtain a phenol resin molding material.

The following evaluation was performed using the phenol resin molding material thus obtained.
[Bending strength, flexural modulus]
A test piece was prepared according to JIS K6911 by injection molding (molding temperature 165 ° C., curing time 90 seconds) (the test piece had 180 ° C. × 8 h after-baking). Using this test piece, bending strength and bending elastic modulus were measured in accordance with JIS K6911.
[Sliding wear test]
A cylindrical resin test piece was produced under the following conditions.
Mold: Test piece mold of desired shape (direct pressure molding)
Molding conditions: mold temperature 165 ° C., pressure 10 MPa, curing time 180 seconds Shape: φ100 mm × 3 mm
180 ° C. × 8 h With annealing treatment A cylindrical resin test piece (rotor, φ100 mm × 3 mm) produced under the above conditions contacts a square plate-like test piece (stator, aluminum A5052, 42 mm × 18 mm × 4 mm) at the top of the test piece. A load of 1.2 kg was applied uniformly to the contact portion. Then, the amount of wear of the rotor (resin molded product) and the stator (aluminum A5052) after rotating the rotor at room temperature for 5 hours at 60 rpm was measured.

  The evaluation results are shown in Table 1.

  From Table 1, in Examples 1-8 in which polyethylene particles having a hydroxyl group and a carboxyl group introduced on the surface as a lubricating substance were blended, they were worn even in a relatively small amount as compared with Comparative Examples 1 and 3 in which this was not blended. And was excellent in sliding characteristics. Further, the mechanical properties (bending strength and flexural modulus) were smaller than those of Comparative Examples 1 and 3.

  In Comparative Examples 2 and 4 in which polyethylene particles not subjected to surface treatment were blended, the mechanical properties (bending strength and flexural modulus) were almost the same as those of Examples 1 and 3 under the same conditions. there were. However, Examples 1 to 8 were significantly superior to Comparative Examples 2 and 4 in suppressing wear.

  From the above results, the molded products of Examples 1 to 8 have greatly improved sliding characteristics while satisfying mechanical characteristics without requiring the use of relatively expensive carbon fibers or aramid fibers instead of glass fibers. It was confirmed that it can be improved.

Claims (5)

A phenolic resin molding material containing a phenolic resin, a fiber reinforcing material, and a lubricating substance, wherein the lubricating substance contains polyethylene particles having hydroxyl groups and carboxyl groups introduced on the surface thereof, and the fiber reinforcing material is a glass fiber The content of the glass fiber is 40 to 65% by mass with respect to the total amount of the phenol resin molding material.   2. The phenol resin molding material according to claim 1, wherein the content of the polyethylene particles into which the hydroxyl group and the carboxyl group are introduced is in the range of 1 to 8 mass% with respect to the total amount of the phenol resin molding material. .   3. The phenol resin molding material according to claim 1, wherein the polyethylene particles into which the hydroxyl group and the carboxyl group are introduced have a weight average molecular weight in the range of 100,000 to 5000000. 4.   The phenol resin molding material according to any one of claims 1 to 3, wherein an average particle diameter of the polyethylene particles into which the hydroxyl group and the carboxyl group are introduced is in the range of 5 to 350 µm.   A molded product, characterized by being formed of a cured product of the phenol resin molding material according to any one of claims 1 to 4.