JPH04191030A - Resin fuel tank - Google Patents

Abstract

PURPOSE:To facilitate the manufacturing of the tank concerned and obtain resin fuel tank, the permeability of fuel such as gasoline or the like through which can easily be judged, by a method wherein magnetic metal. powder is dispersed along a laminar layer in continuous matrix layer. CONSTITUTION:The resin fuel tank 10 concerned has laminar layer 12, which is made of polyamide-based resin and along which magnetic metal powder 13 is dispersed in continuous matrix phase 11 made of polyolefin. The laminar layer 12 mainly locates at the middle to the direction of the thickness of the continuous matrix phase 11 and extends to the direction of its surface. The magnetic metal powder 13 is composed of ferrite, iron oxide, chromium oxide or the like having the particle diameter of 100mum or less and dispersed together with the laminar layer 12 in the continuous matrix phase 11. The preferable mixing ratio of the magnetic metal powder is 1-30wt.%. Thus, the fuel. tank concerned perfectly prevents gasoline or the like from permeating. The quality of the prevention can be checked with an ultrasonic sensor or the like, to say nothing of with a metal finder.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a resin fuel tank, and is devised so that the permeation of fuel such as gasoline can be easily determined.

<Prior Art> Most fuel tanks are made of metal, but fuel tanks made of resin are being considered because they are lightweight and can be easily molded into any shape. However, general resins cannot completely block out gasoline and the like and have some permeability, so it is necessary to perform treatment after molding to completely prevent the penetration of gasoline and the like. Therefore, the following resin fuel tank has been proposed.

First, for example, after blow molding high density polyethylene (HDPE) into a single layer, 803 gas is introduced into the molded product, the molded product is treated in an autoclave, and then the molded product is neutralized with NH3 gas. 80 on the inside
This is a three-processing method.

The second method is to blow 1% F2 gas into the HDPE during blow molding to treat the inner surface of the molded product with fluorine.

The third method is to blow mold a nylon layer that is completely impermeable to gasoline so that HDPE layers are formed on both sides of the center nylon layer. In this case, the adhesive is inserted between the central nylon layer and the HDPE layers on both sides, resulting in a blow-molded product with three types and five layers.

However, all of these methods have a problem in that the manufacturing process and manufacturing equipment become complicated and the manufacturing cost increases. Therefore, a method called the so-called nylon dispersion method, which has a simple manufacturing process, is attracting attention. This method is a method in which HDPE is mixed with a polyamide resin such as SEEK (trade name; manufactured by DuPont), which is nylon with an adhesive added, and the mixture is blow-molded in a single layer. According to this method, as shown in FIG.
A plurality of lamina layers 2 made of polyamide resin are formed at the center in the thickness direction of the continuous matrix phase 1 of DPE.

This lamina layer 2 is discontinuous but extends in a direction perpendicular to the thickness direction, and has the function of preventing gasoline from permeating.

<Problems to be Solved by the Invention> In the nylon dispersion method described above, the nylon lamina layer 2 is formed in the continuous matrix phase 1 because HDPE and nylon, which have different melting points, are not compatible with each other and are not mixed properly. This is because they are stretched in a mixed state. However, there is a problem that the range of temperature conditions etc. under which the lamina layer 2 is formed is narrow, and it is not always clear whether the lamina layer 2 is formed properly. That is, depending on the conditions, the nylon becomes granular and no permeation prevention effect is exhibited, but there is a problem in that it is not possible to ascertain what kind of lamina layer 2 is actually formed.

In view of these circumstances, an object of the present invention is to provide a resin fuel tank that is easy to manufacture and whose permeability to fuel such as gasoline can be easily determined.

Means for Solving the Problems〉 The resin fuel tank according to the present invention that achieves the above object has the following features:
A fuel tank made of a resin molded material having a continuous matrix phase made of polyolefin and a plurality of discontinuous lamina layers made of polyamide resin and extending in a direction substantially perpendicular to the thickness direction in the central part in the thickness direction, The continuous matrix phase is characterized in that magnetic metal powder is dispersed along the lamina layer.

In the above configuration, since the magnetic metal powder is dispersed along the lamina layer in the continuous matrix phase, if the degree of dispersion of the magnetic metal powder is detected by electromagnetic measurement or acoustics, it can be determined how the lamina layer is formed. It would be possible to determine whether it is formed in such a state and judge its ability to prevent the permeation of gasoline, etc.

Example of implementation 9 below, the present invention will be explained based on examples.

FIGS. 1(a) and 1(bl) show the resin fuel tank of this embodiment.

The resin fuel tank 10 shown in FIG. 1(a) is shown in FIG.
As shown in b), a continuous matrix phase 11 made of polyolefin has a lamina layer 12 made of polyamide resin, and magnetic metal powder 13 is dispersed in this lamina layer 12. Here, the lamina layer 12 is mainly formed in the central part in the thickness direction of the continuous matrix phase 11 and extends in the surface direction thereof, which is similar to that formed by the conventional nylon dispersion method.

In the present invention, polyolefin refers to polyethylene, polypropylene, polybutylene, etc., and copolymers of two or more of these. In addition to nylon, the polyamide resin refers to a resin in which nylon is mixed with an adhesive.

On the other hand, in the present invention, the magnetic metal powder has a particle size of, for example, 100 μm.
It refers to ferrite, iron oxide, chromium oxide, etc. under MFD, and it does not matter whether or not it has magnetism in advance. In addition, if the particle size is 1
If it exceeds 00 μm, it is not preferable because it will have an adverse effect on moldability.

In order to manufacture such a resin fuel tank 10, a mixture of polyamide resin and magnetic metal powder may be appropriately mixed with polyolefin, and then molded under stretching conditions similar to the conventional nylon dispersion method. Blow molding may be used in which the extruded cylindrical body is placed in a mold and then stretched by blowing air into it. By stretching and molding in this manner, the magnetic metal powder 13 is dispersed while forming the lamina layer 12 within the continuous matrix phase 11.

The blending ratio of such magnetic metal powder is 1 to 30% by weight.
is preferred. If the amount is less than 1% by weight, the effect will not be exhibited.
On the other hand, if it exceeds 30% by weight, moldability will deteriorate.

Nura (trade name: manufactured by DuPont) is used as a polyamide type resin, and ferrite is mixed with it as a magnetic metal powder, and then this is mixed with high-density, high-molecular-weight polyethylene.
A fuel tank was manufactured by blow molding.

When this fuel tank was measured using an electromagnetic wave measurement N (metal detector), metal was detected throughout the entire area. Note that this fuel tank was completely prevented from permeating gasoline and the like.

For comparison, blow molding was performed in the same manner as in the above example under the condition that no lamina layer was formed, and then measurement was performed with a metal detector. No metal was detected in some places, indicating that the lamina layer was not sufficiently formed. was recognized. Note that this fuel tank allowed gasoline, etc. to permeate through it.

The quality of the resin fuel tank of the present invention can be easily controlled in this way, and it is extremely easy to maintain safety. The method for checking the quality is not particularly limited, and in addition to the above-mentioned metal detector, it can also be checked by, for example, ultrasonic detection, although the device is larger.

<Effects of the Invention> As explained above, the resin fuel tank of the present invention can be easily manufactured by blow molding, etc., and it is also possible to easily measure whether the lamina layer is properly formed. This has the effect of allowing complete quality control.

[Brief explanation of drawings]

FIG. 1 fal, (b) is an explanatory diagram showing a resin fuel tank according to an embodiment of the present invention, and FIG. 2 is a sectional view of a molded body formed by a nylon dispersion method according to the prior art. In the drawings, 10 is a resin fuel tank, 11 is a continuous matrix phase, 12 is a lamina layer, and 13 is a magnetic metal powder. Patent applicant Mitsubishi Motors Corporation representative Patent attorney Hidetoshi Hikari (and one other person) Figure 1 (b)

Claims (1)

[Claims] A fuel tank made of a resin molded material having a continuous matrix phase made of polyolefin and a plurality of discontinuous lamina layers made of polyamide resin and extending in a direction substantially perpendicular to the thickness direction in the central part in the thickness direction, A resin fuel tank, wherein magnetic metal powder is dispersed in the continuous matrix phase along the lamina layer.