JP2000297709A - Intake system component for motorcycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a lightweight, high-elastic modulus, high-heat resistance component excellent in moldability and dimensional stability by forming the whole or part of the intake system component for a motorcycle engine with a polyamide composite material uniformly dispersed with a silicate layer of a stratified silicate on a molecular level. SOLUTION: In manufacturing an intake system component for a motorcycle engine, e.g. an air cleaner housing, an intake silencer, a resonance chamber or an air intake pipe, a polyamide composite material is used, uniformly dispersed with a silicate layer of a stratified silicate on a molecule level, and the component is molded into a desired shape by thermal fusion molding such as injection molding or extrusion molding. The polyamide composite material having the specific gravity of 1.2 or below and the load deflection temperature of 120 deg.C or above at 1.8 MPa is preferably used. A resin composition of the polyamide composite material uniformly dispersed with a silicate layer of a stratified silicate on a molecule level and a thermoplastic resin may be used for the material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system component for a motorcycle engine having excellent moldability, light weight, high elastic modulus, high heat resistance, and excellent dimensional stability.

[0002]

2. Description of the Related Art Conventionally, components constituting an engine mounted on a motorcycle or the like include polyamides excellent in heat cycle resistance, vibration resistance, gasoline resistance, oil resistance, etc. in addition to mechanical properties. Resins have been widely used. However, except for small tank-shaped components, the polyamide resin alone is rarely used alone, and a polyamide composite material containing a reinforcing material represented by glass fiber or talc is used.

[0003] On the other hand, today's environmental problems can be said to be two-wheelers, but the problems of more efficient and compact engines and lighter bodies are unavoidable. In addition, with the diversification of user preferences, There is a need to develop products with higher design. To that end, the adoption of resin parts, which are lightweight and have a high degree of freedom in shape design, is expected to further expand. However, conventionally used polyamide composite materials must incorporate a considerable amount of reinforcing material in order to have sufficient strength and heat resistance, which results in an increase in component weight, deterioration of moldability, etc. There is a problem, especially when a fibrous reinforcing material is used, there is also a problem in the surface appearance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a motorcycle engine having excellent moldability, light weight, high elastic modulus, high heat resistance and excellent dimensional stability. Related to air intake system components.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, a polyamide composite material in which a silicate layer of a layered silicate is uniformly dispersed at a molecular level. The present inventors have found that this object can be achieved by configuring all or a part of the intake system parts for a motorcycle engine, and arrived at the present invention.

That is, the gist of the present invention is as follows. (1) An intake system component for a motorcycle engine, wherein the component is entirely or partially composed of a polyamide composite material in which a silicate layer of a layered silicate is uniformly dispersed at a molecular level. (2) When the specific gravity is 1.2 or less, the deflection temperature under load at 1.8 MPa is
The intake system component for a motorcycle engine according to the above (1), which is at least 120 ° C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

[0008] The polyamide composite material of the present invention is obtained by dispersing a silicate layer of a layered silicate at a molecular level in a polyamide resin. Here, the silicate layer is a basic unit constituting the layered silicate, and is obtained by cleaving the layered silicate. When dispersed at the molecular level, when the layered silicate is dispersed in the polyamide resin,
It means that each of them keeps the interlayer distance of 20 mm or more. In addition, the interlayer distance refers to the distance between the centers of gravity of the silicate layers, and the term “dispersed” means that the silicate layers are parallel to each other, or a multilayer having an average overlap of 5 layers or less. Alternatively, it refers to a state in which 50% or more of them are present in the polyamide resin without forming a lump at random or in a state where parallel and random are mixed. Specifically, wide-angle X-ray diffraction measurement was performed on the pellets of the polyamide composite material, and it was confirmed that peaks due to the thickness direction of the layered silicate had disappeared, or a transmission electron microscope of an ultra-thin section obtained from the pellets. It can be confirmed from observation.

The polyamide resin constituting the polyamide composite material means a polymer having an amide bond formed from aminocarboxylic acid, lactam or diamine and dicarboxylic acid (including a pair of salts thereof).

Preferred examples of such polyamide resins include polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), and polyhexamethylene sebacamide. (Nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyundecamide (nylon 11),
Polidodecamide (nylon 12), polybis (4-aminocyclohexyl) methandodecamide (nylon PACM12),
Polybis (3-methyl-4-aminocyclohexyl) methanedodecamide (nylon dimethyl PACM12), polymethaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide (Nylon 11T
(H)] or their copolymerized polyamides and mixed polyamides, among which nylon 6 and nylon 66 are particularly preferred.

Although the relative viscosity of the polyamide resin is not particularly limited, 96% by weight concentrated sulfuric acid is used as a solvent.
1.5 to 5.0 at a temperature of 25 ° C and a concentration of 1 g / dl.
Is preferred, and those in the range of 2.0 to 3.5 are particularly preferred. If this relative viscosity is less than 1.5,
The mechanical strength when processed into a molded product or the like decreases. on the other hand,
When the relative viscosity exceeds 5.0, the moldability is significantly reduced.

The layered silicates in the present invention include smectites (for example, montmorillonite, banderite, saponite, hectorite, sauconite), vermiculites (for example, vermiculite), and mica (for example, fluoromica, muscovite, paragonite). Phlogopite,
Hydrous inosilicates such as biotite, lepidonite), brittle mica (eg, margarite, clintite, anandite), chlorite (eg, dombasite, sudoite, coucheite, clinochlore, chamonite, nimaite), and sepiolite Minerals and the like can be mentioned, and among these, swellable fluoromica-based minerals (substituted by replacing the hydroxyl group of mica with fluorine, hereinafter referred to as “fluoromica”)
Is preferable in terms of dispersibility of the silicate layer in the polyamide resin.

The fluorine mica is represented by the following formula, and can be easily synthesized. α (MF) · β (aMgF ₂ · bMgO) · γSiO ₂ (where M represents sodium or lithium, α, β,
γ, a and b each represent a count, 0.1 ≦ a ≦ 2, 2 ≦ β
≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, a + b
= 1. )

The method for producing such fluoromica is as follows:
Silicon oxide, magnesium oxide and various fluorides are mixed, and the mixture is heated at 1400 to 1500 ° C in an electric furnace or a gas furnace.
There is a so-called melting method in which the molten mica is completely melted at a temperature of and the crystal of fluorine mica grows in the reaction vessel during the cooling process.

There is also a method in which talc is used as a starting material, and alkali metal ions are intercalated into the starting material to obtain fluorine mica (Japanese Patent Application Laid-Open No. 2-149415). In this method, fluorinated mica can be obtained by mixing talc with an alkali silicofluoride or an alkali fluoride and subjecting the mixture to a short heat treatment at 700 to 1200 ° C. in a porcelain crucible.

In order to obtain the polyamide composite material of the present invention, monomers such as aminocaproic acid, lactam or diamine and dicarboxylic acid which form a polyamide resin may be polymerized in the presence of a predetermined amount of the above layered silicate.

At this time, the ratio of the layered silicate is not particularly limited as long as it can be used as a polyamide composite material having a specific gravity of 1.2 or less and a deflection temperature under load at 1.8 MPa of 120 ° C. or more. The amount is preferably 1 to 10 parts by weight based on 100 parts by weight of the polyamide resin. If the amount is less than 1 part by weight, moldability, elastic modulus, heat resistance,
The effect of improving dimensional stability is not easily exhibited. On the other hand, if the amount exceeds 10 parts by weight, the toughness of the molded product is reduced and the molded product becomes brittle.

It should be noted that a pigment, a release agent, a heat stabilizer, an antioxidant, a flame retardant, a plasticizer, and the like can be added to the polyamide composite material as long as its properties are not significantly impaired. These are added at the time of polymerization or at the time of melt-kneading or melt-molding the obtained polyamide composite material.

The intake system parts for a motorcycle engine of the present invention include an air cleaner housing, an air cleaner cover, an air cleaner case, an intake silencer, a resonance chamber, an air intake pipe, and the like. These parts are obtained by hot-melt molding such as injection molding and extrusion molding, preferably by injection molding, using the above-described polyamide composite material, and have a specific gravity of 1.2 or less and a deflection temperature under load at 1.8 MPa of 120 ° C or more. It is.

Further, in the present invention, a resin comprising a polyamide composite material (component A) in which a silicate layer of the above-mentioned layered silicate is dispersed at a molecular level, and a thermoplastic resin containing no layered silicate (component B) The composition can also be used as an intake system component for a motorcycle engine. These resin compositions are not particularly limited as long as they have a specific gravity of 1.2 or less and a deflection temperature under load at 1.8 MPa of 120 ° C. or more, but are usually 50% by weight or more, preferably 70% by weight as an A component.
The above are used.

Specific examples of the component B include, in addition to the above polyamide resin, polybutadiene, butadiene / styrene copolymer, acrylic rubber, ethylene / propylene copolymer, ethylene / propylene / butadiene copolymer, natural rubber, Chlorinated butyl rubber, elastomers such as chlorinated polyethylene and their acid-modified products such as maleic anhydride, styrene / maleic anhydride copolymer, styrene / phenylmaleimide copolymer, polyethylene, polypropylene, butadiene / acrylonitrile copolymer, Polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide, polyether sulfone, phenoxy resin, polyphenylene ether, polymethylene Methacrylate, polyether ketone, Porika boat, there is polytetrafluoroethylene.

[0022]

Next, the present invention will be described more specifically with reference to examples. In addition, the measuring method of the raw material and each physical property value used in the example and the comparative example is as follows. 1. Raw material (a) Fluorine mica Powdered talc pulverized by a ball mill to an average particle size of 4 μm was mixed with sodium silicate having the same average particle size of 4 μm so as to be 20% by weight of the total amount. The mixture was placed in a crucible and heat-treated at 800 ° C. for 1 hour in an electric furnace to synthesize fluorine mica. Wide-angle X-ray diffraction measurement (RAD-rB type X
As a result, a peak corresponding to a thickness of 9.2 mm in the c-axis direction of the raw material talc disappeared, and a peak corresponding to 12 to 16 mm indicating the formation of fluorine mica was observed. (b) Polyamide composite material (A-1) To 10 kg of ε-caprolactam, 1 kg of water and 200 g of fluoromica were added, and the mixture was placed in an autoclave having a capacity of 30 liters, heated to 260 ° C. Was increased to 15 kg / cm ² . After that, gradually releasing water vapor,
After polymerization for 2 hours while maintaining the pressure at 15 kg / cm ² and the temperature at 260 ° C., the pressure was released to normal pressure over 1 hour, and the polymerization was continued for 40 minutes. When the polymerization was completed, the above reaction product was discharged in a strand shape, cooled, solidified, and cut to obtain a pellet made of a polyamide composite material. Next, the pellets were scoured with hot water of 95 ° C. for 8 hours, and then dried under vacuum. The resulting polyamide composite material contained 2.3% by weight of a silicate layer and had a relative viscosity of 2.5. Further, when wide-angle X-ray diffraction measurement was performed on the pellets of the polyamide composite material, the peak in the thickness direction of the fluoromica completely disappeared, and it was found that the fluoromica was uniformly dispersed in the polyamide resin. Was. (c) Polyamide composite material (A-2) A polyamide composite material was obtained in the same manner as shown in (b) except that 400 g of fluorine mica was used instead of 200 g of fluorine mica. The resulting polyamide composite material contained 4.4% by weight of a silicate layer and had a relative viscosity of 2.5. Also,
Wide-angle X-ray diffraction measurement of the polyamide composite material pellet revealed that the peak in the thickness direction of the fluoromica completely disappeared, indicating that the fluoromica was uniformly dispersed in the polyamide resin. (d) Nylon 6 (N6) Unitika, A1030JR (e) Glass fiber reinforced nylon 6 (N6G) Unitika, A1030GFL (f) Inorganic filled nylon 6 (N6I) Unitika, A3130

2. Measuring method (A) High-cycle moldability The cylinder temperature of an air cleaner housing as shown in Fig. 1 was measured using an injection molding machine (TOSHIBA MACHINE, IS220GN).
The molding was performed under the conditions of 260 ° C., a mold temperature of 70 ° C., and an injection time of 5 seconds, and the obtained molded product was evaluated by measuring the shortest cooling time without causing warpage. (B) Specific gravity Determined by the underwater displacement method based on ASTM D792. (C) Flexural modulus was determined based on ASTM D790. (D) Deflection temperature under load Based on ASTM D648, it was determined at a load of 1.8 MPa. (E) Dimensional change rate The air cleaner housing obtained in (A) was heat-treated at a temperature of 120 ° C. for 100 hours, and the dimensional change rate was obtained from the dimensional change in the width direction of the molded article.

Example 1 A polyamide composite material (A-1) was heated at a cylinder temperature of 260 ° C.
Injection molding using an injection molding machine (TOSHIBA MACHINE CO., IS220GN) under the conditions of ℃, mold temperature of 70 ℃ and injection time of 5 seconds.
Was evaluated for high cycle formability when obtaining an air cleaner housing as shown in FIG. Also, using the molding machine,
Injection molding was performed under the same conditions as described above except that the cooling time was changed to 10 seconds, to obtain a molded article shown in FIG. 1, and the dimensional change was evaluated. Finally, under the conditions of a cylinder temperature of 260 ° C., a mold temperature of 70 ° C., an injection time of 5 seconds and a cooling time of 10 seconds, injection molding was performed using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., IS-80G) to obtain a thickness of 3.2. mm test pieces were prepared, and the specific gravity, flexural modulus, and deflection temperature under load were respectively evaluated using the test pieces. The specific gravity, flexural modulus, and deflection temperature under load determined from the test specimen correspond to the specific gravity, flexural modulus, and deflection temperature under load of the intake system parts for a motorcycle engine, respectively.

Example 2 Each molded article was prepared in the same manner as in Example 1 except that A-2 was used in place of A-1.

Comparative Example 1 Each molded article was prepared in the same manner as in Example 1 except that N6 was used instead of A-1 and the cooling time during molding of the air cleaner housing of FIG. 1 was 30 seconds. Each was subjected to a test.

Comparative Example 2 Each molded product was prepared in the same manner as in Example 1 except that N6G was used instead of A-1 and the cooling time during molding of the air cleaner housing of FIG. 1 was 25 seconds. Each was subjected to a test.

Comparative Example 3 Each molded article was prepared in the same manner as in Comparative Example 2 except that N6I was used in place of A-1, and each molded article was subjected to a test.

Table 1 summarizes the results in Examples 1 and 2 and Comparative Examples 1 to 3.

[0030]

[Table 1]

The polyamide composite materials used in Examples 1 and 2 had excellent moldability, were lightweight, had a high modulus of elasticity, had high heat resistance, and had high dimensional stability. On the other hand, the polyamide resin and the polyamide composite material used in Comparative Examples 1 to 3 lacked at least one of the characteristics described above.

[0032]

According to the present invention, excellent moldability, light weight,
An intake system component for a motorcycle engine having high elastic modulus, high heat resistance, and excellent dimensional stability can be obtained.

[Brief description of the drawings]

FIG. 1 is a general view of an air cleaner housing which is one of components constituting an air cleaner of an engine.

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Claims (2)

[Claims] 1. An intake system component for a motorcycle engine, wherein the component is entirely or partially composed of a polyamide composite material in which a silicate layer of a layered silicate is uniformly dispersed at a molecular level. 2. The intake system component for a motorcycle engine according to claim 1, wherein the specific gravity is 1.2 or less and the deflection temperature under load at 1.8 MPa is 120 ° C. or more.