JP2008075711A - Fuel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel pipe whose volume resistivity can be easily controlled. <P>SOLUTION: The fuel pipe is formed of polyamide 11 or polyamide 12 in which a predetermined amount of metal plated resin fiber is mixed. Herein, the amount of the metal plated resin fiber mixed in the polyamide 11 or the polyamide 12 is 0.5 to 1.0 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel pipe.

Conventionally, there is a resin joint connected to a resin fuel hose in which the volume resistivity of the joint body is set to 10 ⁶ to 10 ¹⁰ Ω · cm (see, for example, Patent Document 1). In the resin joint described in Patent Document 1, the volume resistivity of the joint body is controlled by blending polyamide with a conductive filler. Here, as the conductive filler, carbon black, graphite, stainless steel, or a highly conductive metal material such as copper, silver, or gold is used.

According to such a configuration, since the upper limit value of the volume resistivity of the joint body is limited, it is possible to suppress static electricity charging and thus electrostatic deterioration due to static electricity discharge. Moreover, since the lower limit value of the volume resistivity of the joint is limited, it is possible to suppress a large current from flowing from the joint to the contact portion. As a result, the electrolytic corrosion of the joint due to such a current can be suppressed.
JP 11-294676 A

By the way, since the resin joint described in Patent Document 1 controls the volume resistivity of the joint body by blending a conductive filler with polyamide, the volume resistivity changes rapidly with respect to the blending amount. It will be. For this reason, in order to set the volume resistivity of the joint body to 10 ⁶ to 10 ¹⁰ Ω · cm, it is necessary to precisely control the blending amount of the conductive filler, which still leaves room for improvement. Yes.

  This invention is made | formed in view of such a situation, The objective is to provide the fuel piping which can control volume resistivity easily.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
In the first aspect of the present invention, the fuel pipe is made of polyamide 11 or polyamide 12 in which a predetermined amount of metal-plated resin fibers are blended.

  According to the above configuration, since the fuel pipe is made of polyamide 11 or polyamide 12 in which a predetermined amount of metal-plated resin fibers is blended, a change in volume resistivity with respect to the blending amount is compared with the case of blending a conductive filler. Can be reduced. As a result, the volume resistivity of the fuel pipe can be easily controlled. In addition, a decrease in mechanical properties such as tensile properties, flexibility, and impact properties associated with blending of metal-plated resin fibers into polyamide 11 or polyamide 12 can be suppressed to a small level.

In the fuel pipe according to the first aspect, in the invention according to the second aspect, the compounding amount of the metal-plated resin fiber is set to 0.5 to 1.0 wt%.
When the compounding amount of the metal-plated resin fiber is smaller than 0.5 wt%, the volume resistivity of the fuel pipe becomes larger than 10 ¹⁰ Ω · cm. is there. Moreover, when the compounding amount of the metal-plated resin fiber is larger than 1.0 wt%, the volume resistivity of the fuel pipe is smaller than 10 ⁷ Ω · cm, so that electrolytic corrosion due to current may occur. .

In this respect, according to the above-described configuration, the volume resistivity of the fuel pipe can be controlled to 10 ⁷ to 10 ¹⁰ Ω · cm, so that electrostatic deterioration and electrolytic corrosion of the fuel pipe can be suitably suppressed.

On the other hand, in the invention according to claim 3, the fuel pipe is made of polyamide 11 or polyamide 12 containing a predetermined amount of ionic conductor.
According to the above configuration, the fuel pipe is made of the polyamide 11 or the polyamide 12 in which a predetermined amount of ionic conductor is blended. Therefore, the change in volume resistivity with respect to the blend amount is reduced as compared with the case of blending the conductive filler. be able to. Furthermore, since the ionic conductor has a lower conductivity than a metal or the like, the volume resistivity of the fuel pipe can be suppressed from becoming excessively small. As a result, the volume resistivity of the fuel pipe can be controlled more easily.

In the fuel pipe according to claim 3, in the invention according to claim 4, the blending amount of the ionic conductor is set to 1.0 to 3.0 wt%.
When the blending amount of the ionic conductor is smaller than 1.0 wt%, the volume resistivity of the fuel pipe becomes larger than 10 ¹⁰ Ω · cm, and there is a possibility that electrostatic deterioration due to electrostatic discharge may occur. In addition, when the blending amount of the ionic conductor is larger than 3.0 wt%, the volume resistivity of the fuel pipe does not become smaller than 10 ⁷ Ω · cm, but the mechanical characteristics of the fuel pipe deteriorate. It will be.

In this respect, according to the above configuration, the volume resistivity of the fuel pipe can be controlled to 10 ⁷ to 10 ¹⁰ Ω · cm, and the deterioration of the mechanical characteristics of the fuel pipe can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel piping which can control volume resistivity easily can be provided.

(First embodiment)
Hereinafter, a first embodiment in which a fuel pipe according to the present invention is embodied as an in-tank tube provided in a fuel tank of an in-vehicle engine will be described.

The in-tank tube basically has polyamide 11 or polyamide 12 as a base material, and an organic boron complex potassium salt, an organic boron complex lithium salt, and a lithium perchlorate as an ionic conductor against such a base material. It is formed by mix | blending any one of these. In this embodiment, a sample in which these ionic conductors are dissolved in polyalkylene glycol as a solvent is used. Moreover, you may mix | blend a some salt as an ionic conductor. The fuel pipe according to the present invention is not limited to the in-tank tube. For example, a main passage for supplying the fuel in the fuel tank to the engine and a return passage for returning the fuel supplied to the engine to the fuel tank again. Of course, the present invention can also be applied to an inlet passage, a breather passage, or the like that connects the fuel filler opening and the fuel tank.
(Second Embodiment)
Next, a second embodiment in which the fuel pipe according to the present invention is embodied as an in-tank tube provided in a fuel tank of an in-vehicle engine, with a focus on differences from the first embodiment. explain.

  The intan tube of this embodiment is also basically based on polyamide 11 or polyamide 12. However, particularly in this embodiment, such a base material is blended with any one of copper-plated aramid resin, copper-plated acrylic resin, nickel-plated aramid resin, and copper-plated PET resin as metal-plated resin fibers. It is formed by doing. Note that a plurality of resins may be blended as the metal-plated resin fibers.

  In this embodiment, as these metal-plated resin fibers, those having a fiber length of about 3.5 to 10.0 mm and a fiber diameter of about 15 μm are employed. Moreover, the film thickness of these metal plating is about 0.10 micrometer.

  Here, it is difficult to manufacture a metal-plated resin fiber having a length shorter than 3.5 mm, and those having a length longer than 20.0 mm have poor dispersibility in the base material. Therefore, it is desirable that the length is 3.5 to 20.0 mm. Moreover, if the length of the metal-plated resin fiber is 3.5 mm to 10.0 mm, the dispersibility in the base material can be further improved.

  On the other hand, it is difficult to ensure the desired conductivity when the thickness of the metal plating is thinner than 0.10 μm, and it is difficult to manufacture the thickness of the metal plating thicker than 0.20 μm. The film thickness is preferably 0.10 to 0.20 μm. Moreover, if the film thickness of metal plating shall be 0.10-0.15 micrometer, the manufacture can be made easy, ensuring the desired electroconductivity as plating fiber.

Next, this embodiment will be specifically described with reference to examples and comparative examples.
First, for each of Examples 1 to 8 and Comparative Examples 1 and 2, each component shown in the upper column of Table 1 was blended, and a test piece having a predetermined shape and size was molded. And about each of the obtained test piece, the measurement and evaluation shown below were performed. The results are shown in the lower column of Table 1.

  Next, for each of Examples 9 to 16, each component shown in the upper column of Table 2 was blended, and a test piece having a predetermined shape and size was molded. And about each of the obtained test piece, the measurement and evaluation shown below were performed. The results are shown in the lower column of Table 2.

  Finally, for each of Comparative Examples 3 to 17, each component shown in the upper column of Table 3 was blended, and a test piece having a predetermined shape and size was molded. And about each of the obtained test piece, the measurement and evaluation shown below were performed. The results are shown in the lower column of Table 3.

<Evaluation of tensile properties>
As evaluation of the tensile properties, tensile yield strength, tensile breaking strength, and tensile elongation were measured according to ISO527. The higher the tensile yield strength, the more difficult it is to yield. Moreover, it has a property which is hard to fracture | rupture, so that the numerical value of tensile fracture strength is large. Moreover, it has a tenacious property, so that the numerical value of tensile elongation is large.

<Evaluation of flexibility>
As an evaluation of flexibility, the flexural modulus was measured according to ISO178. It means that the higher the value of the flexural modulus is, the harder it is, and the smaller the value, the better the flexibility.

<Evaluation of impact properties>
As evaluation of impact properties, Charpy impact strength was measured in accordance with ISO179. If the value of Charpy impact strength is small, it is weak against impact, and the larger the value, the better the impact resistance. In Tables 1 to 3, NB is an abbreviation for “Not Break”, meaning that no break occurred.

<Evaluation of volume resistivity>
As an evaluation of the volume resistivity, the volume resistivity was measured according to IEC 60093. When the numerical value of the volume resistivity is large, it is difficult for the current to flow, and as the numerical value is small, the current is likely to flow.

表１中、ポリアミド１１のみからなる比較例１及びポリアミド１２のみからなる比較例２は、各実施例に対する評価基準となる。これら比較例１及び比較例２の体積抵抗率は、１０^１２Ω・ｃｍであり、上記燃料配管の材料として求められる体積抵抗率の範囲（１０^６〜１０^１０Ω・ｃｍ）よりも外となる。

In Table 1, Comparative Example 1 consisting only of polyamide 11 and Comparative Example 2 consisting only of polyamide 12 serve as evaluation criteria for each example. The volume resistivity of Comparative Example 1 and Comparative Example 2 is 10 ¹² Ω · cm, which is outside the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. .

In Examples 1 to 3, 10.0 wt% organoboron complex potassium salt / polyalkylene glycol is blended at a ratio of 10.0 wt%, 20.0 wt%, and 30.0 wt% with respect to polyamide 11, respectively. . That is, in these Examples 1 to 3, the organic boron complex potassium salt is blended by 1.0 wt%, 2.0 wt%, and 3.0 wt%, respectively, as the whole test piece. These volume resistivities are 10 ⁸ to 10 ⁹ Ω · cm and fall within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material of the fuel pipe. As a result of comparison with Comparative Example 1 above, no significant change is observed although the tensile properties and impact properties are slightly reduced as the proportion of the organic boron complex potassium salt / polyalkylene glycol is increased.

In Example 4, 10.0 wt% organoboron complex lithium salt / polyalkylene glycol is blended in a ratio of 10.0 wt% with respect to polyamide 11. That is, in Example 4, 1.0 wt% of the organic boron complex lithium salt is blended as the whole test piece. This volume resistivity is 10 ⁸ Ω · cm, which falls within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. In addition, from the result of the comparison with the above Comparative Example 1, although the tensile properties and impact properties are slightly reduced by the combination of the organoboron complex lithium salt / polyalkylene glycol, no significant change is observed.

In Example 5, 10.0 wt% lithium perchlorate / polyalkylene glycol is blended in a ratio of 10.0 wt% with respect to polyamide 11. That is, in Example 5, 1.0 wt% of perchloric acid lithium salt / polyalkylene glycol was blended as the whole test piece. This volume resistivity is 10 ⁸ Ω · cm, which falls within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. From the results of comparison with Comparative Example 1 above, although the tensile properties, flexibility, and impact properties are slightly reduced by the blend of lithium perchlorate / polyalkylene glycol, no significant change in mechanical properties is observed.

On the other hand, in Examples 6 to 8, polyamide 12 is employed instead of polyamide 11 as the base material, and 10.0 wt% organoboron complex potassium salt / polyalkylene glycol is 10.0 wt% with respect to polyamide 12 respectively. 20.0 wt% and 30.0 wt% are blended. That is, in these Examples 6 to 8, the organoboron complex potassium salt is blended by 1.0 wt%, 2.0 wt%, and 3.0 wt%, respectively, as the whole test piece. These volume resistivities are also 10 ⁸ to 10 ⁹ Ω · cm, as in Examples 1 to 3, and the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω) required as a material for the fuel pipe. -Fits near the center of cm). From the results of comparison with Comparative Example 2 above, there is no significant change in the tensile properties, flexibility, and impact properties that are slightly reduced by the combination of the organic boron complex lithium salt / polyalkylene glycol.

表２中、実施例９及び実施例１０では、銅めっきアラミド繊維をポリアミド１１に対しそれぞれ０．５ｗｔ％、１．０ｗｔ％の割合で配合している。これらの体積抵抗率は１０^７〜１０^９Ω・ｃｍであり、上記燃料配管の材料として求められる体積抵抗率の範囲（１０^６〜１０^１０Ω・ｃｍ）の中心付近に収まる。なお、上記比較例１との比較の結果から、体積抵抗率以外の他の材料物性には大きな変化は認められない。

In Table 2, in Example 9 and Example 10, copper-plated aramid fibers are blended in proportions of 0.5 wt% and 1.0 wt% with respect to polyamide 11, respectively. These volume resistivities are 10 ⁷ to 10 ⁹ Ω · cm, and are within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. In addition, from the result of the comparison with Comparative Example 1, no significant change is observed in the material properties other than the volume resistivity.

In Examples 11 and 12, copper-plated acrylic fibers are blended in proportions of 0.5 wt% and 1.0 wt% with respect to polyamide 11, respectively. These volume resistivities are 10 ⁷ to 10 ⁹ Ω · cm, and are within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. In addition, from the result of the comparison with the comparative example 1, in the example 11 and the example 12, there is no significant change in material properties other than the volume resistivity.

In Example 13 and Example 14, nickel-plated aramid fibers are blended in proportions of 0.5 wt% and 1.0 wt% with respect to polyamide 11, respectively. These volume resistivities are 10 ⁷ to 10 ⁹ Ω · cm, and are within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. In addition, from the result of the comparison with Comparative Example 1, no significant change is observed in the material properties other than the volume resistivity.

In Example 15 and Example 16, copper-plated PET fibers are blended in proportions of 0.5 wt% and 1.0 wt% with respect to polyamide 11, respectively. These volume resistivities are 10 ⁷ to 10 ⁹ Ω · cm, and are within the vicinity of the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. In addition, from the result of the comparison with Comparative Example 1, no significant change is observed in the material properties other than the volume resistivity.

表３中、比較例３〜比較例６では、アセチレンブラックをポリアミド１１に対しそれぞれ５ｗｔ％、１５ｗｔ％、２０ｗｔ％、及び２５ｗｔ％の割合で配合している。これらの体積抵抗率はアセチレンブラックの配合量が５ｗｔ％、１５ｗｔ％のときには１０^１１〜１０^１２Ω・ｃｍであり、上記燃料配管の材料として求められる体積抵抗率の範囲（１０^６〜１０^１０Ω・ｃｍ）よりも外となる。また、同配合量が２０ｗｔ％、２５ｗｔ％のときには１０^２〜１０^５Ω・ｃｍであり、上記燃料配管の材料として求められる体積抵抗率の範囲（１０^６〜１０^１０Ω・ｃｍ）よりも外となる。このことから、アセチレンブラックの配合量に対して体積抵抗率が急激に変化しやすく、体積抵抗率を上記燃料配管の材料として求められる範囲（１０^６〜１０^１０Ω・ｃｍ）に収めるためには緻密な配合量の制御が求められる。

In Table 3, in Comparative Examples 3 to 6, acetylene black is blended in proportions of 5 wt%, 15 wt%, 20 wt%, and 25 wt% with respect to the polyamide 11, respectively. These volume resistivities are 10 ¹¹ to 10 ¹² Ω · cm when the blending amount of acetylene black is 5 wt% and 15 wt%, and the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω) required as a material for the above fuel pipe・ Outside cm). Further, when the blending amount is 20 wt% or 25 wt%, it is 10 ² to 10 ⁵ Ω · cm, which is outside the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material of the fuel pipe. It becomes. Therefore, in order to keep the volume resistivity within the range (10 ⁶ to 10 ¹⁰ Ω · cm) required as a material for the fuel pipe, the volume resistivity is likely to change rapidly with respect to the blending amount of acetylene black. A precise control of the amount is required.

In Comparative Examples 7 to 9, ketjen black is blended with polyamide 11 in proportions of 2 wt%, 5 wt%, and 7 wt%, respectively. When the blending amount of ketjen black is 5 wt%, the volume resistivity is 10 ⁸ Ω · cm, which is approximately the center of the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. However, when the blending amount is 2 wt%, the volume resistivity is 10 ¹² Ω · cm, and when 7 wt%, the volume resistivity is 10 ³ Ω · cm. From this, the volume resistivity tends to change rapidly with respect to the blending amount of ketjen black, and the volume resistivity falls within the range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material for the fuel pipe. Requires precise control of the blending amount.

In Comparative Example 10 to Comparative Example 13, carbon fibers are blended in proportions of 5 wt%, 15 wt%, 20 wt%, and 25 wt% with respect to polyamide 11, respectively. These volume resistivity values are 10 ¹¹ to 10 ¹² Ω · cm when the carbon fiber content is 5 wt% or 15 wt%, and the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω) required as a material for the fuel pipe is described above.・ Outside cm). Further, when the blending amount is 20 wt% or 25 wt%, it is 10 ² to 10 ⁵ Ω · cm, which is outside the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as a material for the fuel pipe. It becomes. From this, the volume resistivity tends to change abruptly with respect to the blending amount of the carbon fiber, and in order to keep the volume resistivity within the range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material of the fuel pipe. A precise control of the amount is required.

In Comparative Examples 14 to 17, for example, metal fibers such as nickel are blended in the proportions of 5 wt%, 15 wt%, 20 wt%, and 25 wt% with respect to the polyamide 11, respectively. These volume resistivity values are 10 ¹¹ to 10 ¹² Ω · cm when the blending amount of the metal fiber is 5 wt% or 15 wt%, and the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω) required as a material for the fuel pipe is described above.・ Outside cm). Further, when the blending amount is 20 wt% or 25 wt%, it is 10 ² to 10 ⁵ Ω · cm, which is outside the volume resistivity range (10 ⁶ to 10 ¹⁰ Ω · cm) required as a material for the fuel pipe. It becomes. From this, the volume resistivity tends to change rapidly with respect to the blending amount of the metal fiber, and the volume resistivity is within the range (10 ⁶ to 10 ¹⁰ Ω · cm) required as the material of the fuel pipe. A precise control of the amount is required. In addition, it has been confirmed by the inventor that stainless steel, nickel, aluminum, silver, gold, and the like as these metal fibers exhibit the same tendency as the volume resistivity characteristics of nickel.

Thus, even when carbon fiber or metal fiber is blended with polyamide 11, if the blending amount thereof is precisely controlled, the volume resistivity of the fuel pipe can be obtained as a range (10 ⁶ to 10 ⁶ ). 10 ¹⁰ Ω · cm). However, in this case, a large amount of carbon fiber or metal fiber must be blended at a rate of about 15 to 20 wt%. For this reason, in Example 9-16 which mix | blends resin by which metal plating was carried out, the compounding quantity can be restrained to 1/10 or less compared with the case where carbon fiber and a metal fiber are mix | blended. The reason why the amount of the metal-plated resin can be reduced to such a small amount is considered that the metal-plated resin has higher conductivity per unit mass than the metal fiber or carbon fiber. . That is, since metal fibers and carbon fibers are easily broken by shear stress acting at the time of forming the test piece, the blending amount must be increased in order to ensure the conductivity of the entire test piece. On the other hand, most of the metal-plated resin is resin, so that it has high flexibility and is not easily broken even when a test piece is molded. Therefore, the metal-plated resin fiber can ensure flexibility and weight reduction through the resin fiber portion, and can secure desired conductivity through the metal plating portion.

Claims (4)

  A fuel pipe made of polyamide 11 or polyamide 12 containing a predetermined amount of metal-plated resin fibers.   The fuel pipe according to claim 1, wherein the amount of the metal-plated resin fiber is 0.5 to 1.0 wt%.   A fuel pipe made of polyamide 11 or polyamide 12 containing a predetermined amount of ionic conductor.   The fuel pipe according to claim 3, wherein a blending amount of the ionic conductor is 1.0 to 3.0 wt%.