JPH04191029A - Resin fuel tank - Google Patents

Abstract

PURPOSE:To facilitate the manufacturing of the tank concerned and obtain the resin fuel tank, which has no fear of the permeation of fuel such as gasoline or the like by a method wherein fine flat particles are dispersed nearly parallel to the direction of its surface in continuous matrix phase. CONSTITUTION:The resin fuel tank 10 concerned has a laminar layer 12, which is made of polyamide-based resin, mainly located at the middle to the direction of the thickness of continuous matrix phase 11 and extends to the direction of its surface, in the continuous matrix phase 11 made of polyolefin. Further, fine flat particles 13 are dispersed nearly parallel to the direction of the surface of the continuous matrix phase 11 and made of fine flat inorganic particles such as mica, talc or the like. The larger the ratio of the diameter to the thickness L/t of each particle, the more preferable. For example, the particle diameter is 20-100mum and L/t is 5 or more, preferably 10 or more. In the resin fuel tank 10, since the above-mentioned fine flat particles 13 are dispersed nearly parallel to the direction of the surface in continuous matrix phase 11, gasoline or the like is prevented from permeating.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin fuel tank, which is devised to completely prevent permeation of fuel such as gasoline.

<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, high-density polyethylene (HDPE) is blow-molded into a single layer, and then SO gas is introduced into the molded product and treated in an autoclave, followed by neutralization with NH gas. The inside of the product is S03
It is a method of processing.

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 polyamide-based I/M resin, such as SEEK (trade name; manufactured by DuPont), which is nylon with an adhesive added, and multilayer blow molding is performed. According to the darning method, as shown in FIG. 2, 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 HDPE. 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 above-mentioned nylon dispersion method, the formation of the nylon lamina layer 2 in the continuous matrix phase 1 is as follows: 1. This is because HDPE and nylon, which have different melting points, are not miscible and are stretched in a properly 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. In other words, depending on the conditions, nylon becomes granular,
The permeation prevention effect does not appear. Further, even if the lamina layer 2 is formed properly, there is a problem that the permeation prevention effect is about 1/10 as low as that of the multilayer structure described above.

In view of these circumstances, an object of the present invention is to provide a resin fuel tank that is easy to manufacture and free from the risk of permeation of fuel such as gasoline.

<I! Means for Solving the Problem> A 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 discontinuous number of lamina layers made of a polyamide resin and extending in a direction substantially perpendicular to the thickness direction in the central part in the thickness direction of the continuous matrix phase made of polyolefin, , the continuous matrix phase is characterized in that flat fine particles are dispersed substantially parallel to the plane direction of the continuous matrix phase.

Effect> In the above structure, the flat fine particles in the continuous matrix phase prevent gasoline etc. from permeating through the wall of the fuel tank, similar to the lamina layer. Therefore, together with the action of the lamina layer, or even if the action of the lamina layer is not perfect, the permeation of gasoline etc. is completely prevented.

Example of implementation The present invention will now be explained based on examples.

FIGS. 1A and 1B show a resin fuel tank of this embodiment.

The resin fuel tank 10 shown in FIG.
1) As shown in 1, a continuous matrix phase 11 made of polyolefin has a lamina layer 12 made of a polyamide resin, and flat fine particles 13 are dispersed therein.

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, flat fine particles 13 are further dispersed. The flat fine particles 13 are dispersed so as to be substantially parallel to the surface direction of the continuous matrix phase 1, and have the function of permeating gasoline and the like like the lamina layer 12.

In the present invention, polyolefin refers to polyethylene, polypropylene, polybutylene, etc., and copolymers of two or more of these. In addition to Nanolon, polyamide resin refers to a resin made by mixing nylon with an adhesive.

On the other hand, flat fine particles are free particles such as mica and talc.
- Refers to a flattened particle, the ratio of its diameter and thickness,
The larger L/l is, the more preferable. For example, the particle size is 20-10
0 μm, L/l is 5 or more, preferably ]0 or more.

If the particle size is less than 20 μm, it is difficult to exhibit the effects of the present invention, and if the particle size exceeds 100 μm, the particles will not be flat and will easily form into blocks, leading to deterioration of moldability. In addition, if L/t is small, it will still form into blocks, leading to deterioration of moldability, and the effects of the present invention will not be obtained. Examples of materials that satisfy these conditions include mica that has been caught on a boat and processed talc, but even in the case of mica, it is better to use thinly sliced mica to obtain a greater effect.

In the resin fuel tank 10 of this embodiment, such flat fine particles 13 are dispersed in the continuous matrix phase 11 so as to be substantially parallel to the surface direction thereof, as described above.
Even if the lamina phase 12 is not properly formed, permeation of gasoline etc. is prevented.

In order to manufacture such a resin fuel tank 10, it is sufficient to mix polyolefin, polyamide resin, and flat fine particles appropriately, and then to form the resin under stretching conditions similar to the conventional nylon dispersion method. Blow molding may be performed in which the extruded cylindrical body is placed in a mold and then stretched by blowing air into it.By stretching in this manner, the flat fine particles are dispersed approximately parallel to the plane direction of the continuous matrix phase. , which acts to prevent the permeation of gasoline, etc.

The blending ratio of such flat fine particles is preferably 1 to 30% by weight. This is because if it is less than 1% by weight, the effect will not be exhibited, while if it exceeds 30% by weight, it will lead to deterioration of moldability.

Using Theta (trade name: manufactured by DuPont) as a polyamide type resin, flattened mica was mixed with it as flattened fine particles, and then this was mixed with high-density, high-molecular-weight polyethylene.
A fuel tank was manufactured by blow molding. Such fuel tanks were completely prevented from permeating gasoline and the like.

<Effects of the Invention> As explained above, the resin fuel tank of the present invention can be easily manufactured by blow molding, etc., and even if the lamina layer is not properly formed, the flat particles ensure complete fuel permeation. It is highly safe.

[Brief explanation of the drawing]

FIGS. 1A and 1B are explanatory diagrams showing a resin fuel tank according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a molded body formed by a nylon dispersion method according to the prior art. Among them, 10 is a resin fuel tank, 11 is a continuous matrix phase, 12 is a lamina layer, and 13 is flat fine particles.Patent applicant: Mitsubishi Motors Corporation, agent

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 characterized in that the continuous matrix phase has flat fine particles dispersed substantially parallel to the surface direction of the continuous matrix phase.