JPH04272592A - Tube for transferring fuel - Google Patents

Abstract

PURPOSE:To provide a fuel transfer tube which can be used for either alcohol, gasoline or a fuel obtained by mixing of the two and which has flexibility. CONSTITUTION:A fuel transfer pipe has a polyamide resin layer 2 containing methaxylyrene group and having a thickness of not more than 0.3mm and a polyolefine type resin layer 3 and both of the layered are formed by the method of simultaneous extrusion molding.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The invention of this application is based on alcohol,
This invention relates to a tube for transferring gasoline and mixed fuel thereof (herein referred to as a fuel transfer tube).

0002

2. Description of the Related Art A tube for transporting an alcoholic medium is composed of a polyamide layer 9 and a polyolefin layer 9' on the inner surface thereof, as shown in FIG. This material is used, for example, in tubes for transferring media for automobile brake systems (alcohol is added to prevent freezing), and in this case, the presence of a polyolefin layer that is alcohol-resistant and impermeable. As a result, the safety of the brake system is significantly superior compared to conventional tubes made of polyamide.

However, when tests were conducted using the tube described above to transport alcohol and gasoline separately (see below: ① gasoline permeation test, ③ moisture permeation test, etc.), it was found that the tube was resistant to gasoline. It was confirmed that the quality was not good. The method of this test is shown below, and the test results are shown in Table 1. In addition, in this test, the outer diameter was 8 mm, the inner diameter was 6 mm, and the thickness of the polyamide layer 9 was 0.
．． 9mm, and the thickness of the polyolefin layer 9' is 0.1mm.
We adopted a tube with a [Test method] ■. Gasoline permeation test A 200 mm tube (outer diameter 8, inner diameter 6 mm) was filled with gasoline and left in an oven at 50°C for 5 days, and weight loss was measured. ■． A moisture adsorbent (molecular sieve) was sealed in a moisture permeation test tube and left in a constant temperature and humidity chamber at 40° C. and 95% RH, and the weight increase of the moisture adsorbent was measured. ■． Flexibility Test The load required to hold a 400 mm tube end and wind it 180° into a semicircle with a radius of 100 mm was measured. ■． Test for length change due to alcohol absorption Methyl alcohol was sealed in a 200 mm tube, and the length change was measured after being left at 20° C. for 7 days. 〔Test results〕

0004

[Table 1]

[0005] The symbols ◎, ○, △, and × in Table 1 above are shown in Table 2 below.

[0006]

[Table 2]

That is, from Tables 1 and 2, it can be seen that the above-mentioned tubes have good alcohol resistance, but low gasoline impermeability.

[0008]

SUMMARY OF THE INVENTION An object of the invention of this application is to provide a flexible fuel transfer tube that can be used with alcohol, gasoline, or a mixture of these fuels.

[0009]

[Means for Solving the Problems] The invention of this application relates to a fuel transfer tube having a metaxylylene group-containing polyamide resin layer and a polyolefin resin layer having a thickness of 0.3 mm or less, which are coextruded. It is formed by a molding method.

0010

[Operations] The invention of this application has the following functions. Even if the metaxylylene group-containing polyamide resin layer is 0.3 mm or less, it is possible to suppress the permeation of gasoline to a much smaller level than the polyamide resin layer, and the polyolefin resin layer ensures alcohol resistance. That will happen.

[0011] Since the metaxylylene group-containing polyamide resin layer is 0.3 mm or less, flexibility, which is an essential function in a tube, can also be ensured.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the invention of this application will be explained below with reference to the drawings showing examples. (Example 1) In this example, as shown in FIG.
It is composed of two layers, the interior of which is a metaxylylene group-containing polyamide resin layer 2 (hereinafter referred to as MX nylon layer 2), and the exterior is a polyolefin resin layer 3 (hereinafter referred to as PO
layer 3). Said MX nylon layer 2
is set to 0.2 mm, and the PO layer 3 is set to 0.8 mm, and the tube as a whole is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Example 2) In this example, as shown in FIG.
It is composed of three layers, from the inside to the outside: a PO layer 3, an MX nylon layer 2, and a polyamide resin layer 1 (
They are laminated in this order (hereinafter referred to as nylon 12 layer 1). The PO layer 3 is set to 0.1 mm, the MX nylon layer 2 is set to 0.1 mm, and the nylon 12 layer 1 is set to 0.8 mm, and as in the above example, the outer diameter is 8 mm and the inner diameter is 6 m.
m. (Example 3) In this example, as shown in FIG.
It is composed of four layers, and the layers are laminated in the following order from inside to outside: MX nylon layer 2, nylon 12 layer 1, PO layer 3, and ultra-high molecular weight polyethylene layer 5. The MX nylon layer 2 has a thickness of 0.1 mm and is made of nylon 12.
Layer 1 is set to 0.35 mm, PO layer 3 is set to 0.05 mm, and ultra-high molecular weight polyethylene layer 5 is set to 0.5 mm.
It is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Example 4) In this example, as shown in FIG.
It is composed of four layers, and the layers are laminated in the order from the inside to the outside: an elastomer-containing nylon layer 6, a PO layer 3, an MX nylon layer 2, and a nylon 12 layer 1. The elastomer-containing nylon layer 6 has a thickness of 0.35 mm, P
O layer 3 is 0.05 mm, MX nylon layer 2 is 0.1 mm
, nylon 12 layer 1 is set to 0.5 mm,
It is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Example 5) In this example, as shown in FIG.
It is composed of 5 layers, from the inside to the outside: 6 layers of elastomer-containing nylon 6, PO layer 3, MX nylon layer 2, PO layer 3, 12 layers of elastomer-containing nylon 7
They are stacked in this order. The elastomer-containing nylon 6 is 0.35 mm, the PO layer 3 is 0.05 mm, MX
The nylon layer 2 is set to 0.1 mm, the elastomer-containing nylon 12 layer 7 is set to 0.45 mm, and the outer diameter is 8 mm.
It is formed to have an inner diameter of 6 mm.

[0013] As for the method of forming the fuel transfer tubes of Examples 1 to 5 described above, any method known per se such as coextrusion molding or extrusion coating can be adopted. An endless tube can be efficiently obtained by coextrusion using a standard extruder and a multilayer tube die. Each resin can be molded into any shape as long as the temperature is above the softening point and below the decomposition point;
Preferably, the molding is carried out in a temperature range of 80°C.

[0014] Definitions of the main resins mentioned above are shown below, and Table 1 shows the results obtained by a test method similar to that described in the prior art section. [Definition of main resins] (Metaxylylene group-containing polyamide resin) In the present invention, metaxylylene group-containing polyamide resin includes metaxylylene diamine or metaxylylene diamine and paraxylylene diamine in an amount of 30% or less of the total amount. Examples include polymers containing at least 70 mol% of structural units in the molecular chain formed from mixed xylylene diamine and an α,ω-aliphatic dicarboxylic acid having 4 to 10 carbon atoms.

Examples of these polymers include homopolymers such as polymethaxylylene adipamide, polymethaxylylene sebacamide, polymethaxylylene speramide, etc., and metaxylylene/paraxylylene adipamide copolymers. , metaxylylene/paraxylylene pimeramide copolymer, metaxylylene/paraxylylene azeramide copolymer, etc., as well as components of these homopolymers or copolymers such as hexamethylene diamine. Aliphatic diamines, cycloaliphatic diamines such as piperazine,
Aromatic diamines such as para-bis(2-aminoethyl)benzene, aromatic dicarboxylic acids such as terephthalic acid, lactams such as ε-caprolactam, ω-aminocarboxylic acids such as γ-aminoheptanoic acid, para-amino Examples include copolymers obtained by copolymerizing aromatic aminocarboxylic acids such as methylbenzoic acid. In the above copolymer, para-xylylene diamine accounts for 30% or less of the total xylylene diamine, and the constituent units formed from xylylene diamine and aliphatic dicarboxylic acid account for at least 70 mol% or more in the molecular chain. It is.

The meta-xylylene group-containing polyamide resin itself is inherently brittle in an amorphous state, so its relative viscosity is usually 1.5.
It needs to be at least 2.0, preferably 2.0 to
It is 4.0. In addition, these polymers include, for example, nylon 4.6, nylon 6, nylon 6.6, nylon 6.
10, nylon 6/12, nylon 11, nylon 12
, a homopolymer or a copolymer such as nylon 12/12 may be contained.

In addition, in order to improve flexibility, a soft rubber material such as styrene, butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene/propylene rubber, acrylic rubber, urethane rubber, chlorosulfone is added to the metaxylylene group-containing polyamide resin. ethylene/chloroprene rubber, fluororubber, etc., and thermoplastic elastomers such as polyester elastomers, polyamide elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers, styrene elastomers, etc. from 0 to 97% by weight, preferably from 20 to 85% by weight.
It may be added by weight%. Also, elastic modulus 12000kg/c
A relatively soft thermoplastic resin having a diameter of m2 or less may be blended.

[0018] In the present invention, various additives may be added as necessary within a range that does not impair the present invention. Examples of additives include colorants, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, nucleating agents, plasticizers, flame retardants, impact-resistant agents, and inorganic fillers. (Polyamide Resin) As the polyamide resin used in the present invention, a high molecular weight linear polyamide is used. The polyamide may be a homopolyamide, a copolyamide or a blend thereof.

Such polyamides include, for example, the following amide repeating units: -CO-R1 -NH-
...(
1) or -CO-R2 -CONH-R3 -NH
...(2) (in the formula,
Mention may be made of homopolyamides, copolyamides or blends thereof having amide repeating units in which each of R1, R2 and R3 represents a linear alkylene group. Considering gas barrier properties against oxygen, carbon dioxide, etc., the number of amide groups per 100 carbon atoms in the polyamide resin used in the present invention is 3 to 30, particularly 4 to 2.
Preferably, a range of 5 homopolyamides, copolyamides or blends thereof are used. Examples of suitable homopolyamides include polycapramide (nylon 6), poly-ω-aminohepetanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), polyundecaneamide (nylon 11), polylaurinlactam ( Nylon 12), polyethylenediamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6), polyhexamethylene adipamide (nylon 6,6), polyhexamethylene sebacamide (nylon 6) ，
10) Polyhexamethylene dodecamide (nylon 6,1
2) Polyoctamethylene adipamide (nylon 8,6)
, polydecamethylene adipamide (nylon 10,6),
Polydecamethylene sebaamide (nylon 10,10),
Polydodecamethylene dodecamide (nylon 12,12)
etc. can be given. Examples of copolyamides suitable for use in the present invention include caprolactam/
Laurin lactam copolymer, caprolactam/hexamethylene diammonium adipate copolymer, laurin lactam/hexamethylene diammonium adipate copolymer, hexamethylene diammonium adipate/hexamethylene diammonium sepacate copolymer, ethylene diammonium adipate/ Examples include hexamethylene diammonium adipate copolymer, caprolactam/hexamethylene diammonium adipate/hexamethylene diammonium sepacate polymer, and the like.

[0020] Furthermore, in order to impart flexibility to these polyamides, plasticizers such as aromatic sulfonamides, P-hydroxybenzoic acid, and esters, elastomer components with low elasticity, and lactams may be blended. . Elastomer components include ionomer resin, modified polyolefin resin, polyether amide resin, polyester amide resin, polyether ester amide resin, polyether ester resin, modified styrene thermoplastic elastomer, modified acrylic rubber, modified ethylene/propylene rubber, etc. Good compatibility with polyamide resin, elastic modulus 3000kgf/
A single or a combination of elastomers selected from the following elastomers are preferred. (Polyolefin resin) The polyolefin resin used in the present invention is generally a hydrocarbon resin, such as polyethylene, polybutadiene, polyisoprene, polyisobutylene, polybutylene, polymethylpentene,
Olefin polymers such as polypropylene, polyterpene resin, polybutene, ethylene-butadiene copolymer, and ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-decene, 1-hexadecene, 1- α-olefin copolymers obtained by copolymerizing two or more types of icosene; Saturated monocarboxylic acids, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, nadic acid, unsaturated dicarboxylic acids such as methylnadic acid, acid halides and amides of the unsaturated carboxylic acids, Acid-modified olefin polymers and acid-modified α-olefin copolymers obtained by graft copolymerizing derivatives such as imides, anhydrides, and esters, or copolymers of these acid-modified α-olefin copolymers and diene components, etc. For example, one type or a mixture of two or more of the above polyolefin resins can be used.

[0021] Furthermore, it is not necessary to be limited to thermoplastic resins in particular, and it goes without saying that crosslinked polyolefin resins such as crosslinked polyethylene are also included. A suitable example is water-crosslinked polyolefins, which are polyolefins copolymerized or grafted with compounds containing silyl groups with hydrolyzable organic groups, which are treated by the action of water in the presence of a silanol condensation catalyst. Examples include polyolefins that can be crosslinked. 〔Test results〕

[0022]

[Table 3]

[0023] The symbols ◎, ○, △, × in Table 3 above are as shown in Table 2.
This is shown below.

[0024]

Effects of the Invention Since the invention of this application has the above-described configuration, it has the following effects. From Table 3 in the Effect column, it was possible to provide a flexible fuel transfer tube that can be used with any of alcohol, gasoline, and mixed fuels thereof.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view of a fuel transfer tube according to a first embodiment of the invention of this application.

FIG. 2 is a cross-sectional perspective view of a fuel transfer tube according to a second embodiment of the invention of this application.

FIG. 3 is a cross-sectional perspective view of a fuel transfer tube according to a third embodiment of the invention of this application.

FIG. 4 is a cross-sectional perspective view of a fuel transfer tube according to a fourth embodiment of the invention of this application.

FIG. 5 is a cross-sectional perspective view of a fuel transfer tube according to a fifth embodiment of the invention of this application.

FIG. 6 is a cross-sectional perspective view of a conventional tube.

[Explanation of symbols]

2 Metaxylylene group-containing polyamide resin layer 3 Polyolefin resin layer

Claims (1)

[Claims] 1. A fuel transfer tube comprising a metaxylylene group-containing polyamide resin layer having a thickness of 0.3 mm or less and a polyolefin resin layer, the tube being formed by a co-extrusion method.