JP3107404B2 - How to improve barrier properties of hoses for automotive parts piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a burr for a hose for automotive parts piping.
Relates to yer improving method, in particular lightweight, and the resin hose which is excellent in corrosion resistance, fuel barrier hose may be suitably used for a refrigerant piping system in the fuel piping system and air conditioner etc.
The present invention relates to a method for improving the properties and refrigerant (gas) barrier properties .

[0002]

2. Description of the Related Art Conventionally, fuel pipe hoses used in automobiles have various types of rust-free, lightweight, flexible, and excellent fuel barrier properties (fuel impermeability). Performance is required, and a hose for transporting a refrigerant such as an air conditioner is required to be excellent in gas impermeability. At present, various hoses made of metal, rubber, resin and the like are provided, but from the viewpoint of lightness and rust prevention, a part of the hoses for piping is made of polyamide resin. Hose has been used.

[0003] However, the polyamide resin hose has a problem that the fuel barrier property and the gas barrier property are insufficient. Further, when a fire occurs, the polyamide resin is melted by the flame and gasoline leaks. However, such a problem is inherent, and it cannot be said that it is necessarily suitable as a hose for piping.

[0004]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a single-layer or multi-layer resin hose excellent in light weight and rust prevention properties by using gasoline. It is another object of the present invention to further improve the barrier property against an internal fluid such as a fuel and a refrigerant gas.
Another object of the present invention is to make it possible to effectively prevent the hose from melting in a fire.

[0005]

A Then, to solve the above problems, the present inventors have conducted extensive studies, by cross-linking structure is introduced by a predetermined irradiation, a predetermined forming at least one layer of the hose structure layer It has been found that both the fuel barrier property and the gas barrier property of the resin material can be advantageously improved, and the melting resistance can also be effectively improved.

Namely, the present invention has been made based on this finding, and its gist, monolayer or a multilayer hose construction, and at least one layer tree fat of the hose structure layer Layer and inside
Hose for piping of automobile parts through which fuel and refrigerant are distributed
The method for improving barrier properties of
, Polyester, polystyrene, polyacrylate,
Polyacrylamide, polyvinyl chloride, polyvinyl alcohol
Coal, polyvinylidene fluoride, or polyethylene
Consists of tetrafluoroethylene copolymer and aids in crosslinking
While the resin layer is composed of a layer to which an agent is added.
Using electron beams as radiation and irradiating them
This leads to a crosslinked structure between polymer molecules in the resin layer.
Automobile parts pipe, characterized in that the so that allowed entry
In the method for improving the barrier properties of hoses for use .

[0007]

DETAILED DESCRIPTION In short, the piping hose according to the present invention
In the barrier improvement method, a resin layer <br/> crosslinking is performed using an electron beam as the radiation is than so that the always provided as one of the hose structure layer, and the properties of such resin layer Based on this, excellent fuel barrier properties, gas barrier properties, and melting resistance can be exhibited . The resin material constituting this resin layer includes radiation-crosslinkable polystyrene, polyacrylate, polyacrylamide, polyvinyl chloride, polyamide, polyester, polyvinyl alcohol, polyvinylidene fluoride, and polyethylene-tetrafluoroethylene copolymer. Can be mentioned.

Further, in those resin materials, in order to increase the crosslinking efficiency, Ru Nodea the rack HashiSukezai is made to the addition. Well-known such crosslinking aids include HDDA (hexadiol diacrylate), TP
GDA (tripropylene glycol diacrylate),
DEGDA (diethylene glycol diacrylate),
TEGDA (tetraethylene glycol diacrylate), TMPTA (trimethylolpropane triacrylate), GPTA (glycerol propoxy triacrylate), TMPEOTA (trimethylolpropane ethoxy triacrylate), PETA (pentaerythritol acrylate), TAIC (triallyl isocyanurate) , THEICA (trishydroxyethyl isocyanuric acrylate), S ₂ Cl _{2 and the} like, and any of them can be used in the present invention. The specific type and amount of the crosslinking aid are determined according to the type of the resin material used and the desired degree of crosslinking.

Further, if necessary, any other property imparting agent or additive may be appropriately added to the resin material without any problem.

Then, in order to form a target resin layer from the resin material containing such a crosslinking aid, the resin material is melted at a melting temperature using a commonly used twin screw extruder or the like. After uniformly kneading under the region, it may be molded according to a normal hose extrusion molding operation. For example, when forming a hose having a single-layer structure, the resin material is extruded onto a predetermined mandrel to form a tubular body (resin layer), and the tubular body is cured or solidified in that state. Thus, it is possible to form a hose having a defined inner diameter.

Next, in the present invention, by irradiating the hose thus formed with predetermined radiation,
The resin forming the hose constituent layer is cross-linked. At that time, such radiation includes electron beam
So that the but be adopted. Then, the irradiation amount is appropriately adjusted according to the type of the resin material and the desired degree of crosslinking.

The hose thus completed has a fuel barrier property and a gas barrier property which are effectively improved by introducing a crosslinked structure between polymer molecules of the resin layer. It exhibits the property that melting is effectively prevented.

When the hose is formed, it is possible to perform the forming without using a mandrel. Also,
The thickness of the hose is appropriately determined depending on the desired barrier property and flexibility. In the case of a hose having a single-layer structure, the thickness is preferably about 0.5 to 1.5 mm.

The present invention can be applied to a hose having a two-layer structure or a multilayer structure having three or more layers. In such a case, at least one layer is formed as the radiation-crosslinked resin layer, and the remaining layers are formed by lamination with other various resin materials, rubber materials, or the like, so that the desired hose is formed. Obtainable.

Further, the single-layer or multi-layer resin hose to which the present invention is applied is provided on the outside thereof with a solid material such as a rubber material, a soft resin, or a thermoplastic elastomer, a foam, or the like. A protective layer having a thickness of about 2 mm may be provided. In this case, the protective layer and the resin hose may be adhered to each other as necessary.

[0016]

EXAMPLES Hereinafter, some examples of the present invention will be described to clarify the present invention more specifically. However, the present invention imposes some restrictions by the description of such examples. It goes without saying that you don't receive anything. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

First, as a resin material, nylon 11 (P
A11) and polybutylene terephthalate (PBT) were prepared, and triallyl isocyanurate (TAIC) was added as a crosslinking aid at a ratio of 5% by weight to each of them to prepare a hose-forming material. According to
A tubular body having an inner diameter of 6 mmφ and an outer diameter of 8 mmφ was formed.
Then, after the tubular body is cured, a predetermined radiation (electron beam)
And irradiated in the irradiation amount indicated in Table 1, allowed crosslinking, a hose (Example Nanba1～3) aimed its
I got each.

The hose thus obtained was examined for fuel barrier properties and melting resistance by the following test method.
The results are shown in Table 1 below. As a comparative example, a hose made of nylon 11 and a hose made of polybutylene terephthalate were produced without performing radiation (electron beam) crosslinking, and the same test was performed. The results are also shown in Table 1 below. Shown.

Fuel Barrier Property A test gasoline is sealed in each hose and left at a temperature of 40 ° C. to reduce its weight (g / m ² · day).
Was measured.

Melting resistance Each hose was cut into a length of 20 mm,
The hose was left in an atmosphere of each of 50 ° C., 300 ° C., and 350 ° C. for 10 minutes, and the melting state of the hose was observed. In the table,
The case where the hose shape was maintained was represented by ○, and the case where the hose shape was melted and collapsed was represented by ×.

[0021]

[Table 1]

From the results shown in Table 1, Comparative Example No. By comparing the hose of Example No. 1 with the hoses of Example Nos. 1 and 2, the weight of the hose subjected to the electron beam crosslinking according to the present invention is reduced, and the fuel barrier property is improved. It turns out that there is. It is also apparent that the melting resistance has been improved. The same effect can be obtained by comparing the hose of Comparative Example No. 2 with the hose of Example No. 3. Further, the hose of Example No. 1 and the hose of Example No. 2 have a difference in fuel barrier property due to a difference in irradiation amount of the electron beam, and this resin material (PA11 + TAIC)
It has been found that by adjusting the irradiation amount to around 50 Mrad, extremely excellent characteristics can be obtained.

Examples Nos. 1 to 3 and Comparative Example N
o. 1 to 2 enclosed respectively refrigerant to each hose was measured permeation amount of gas, it was compared gas barrier property, that the gas barrier properties of the hose of Example No. 1 to 3 are improved confirmed.

[0024]

As is apparent from the above description, in the method for improving the barrier property of a hose according to the present invention, at least one predetermined resin layer as a hose constituent layer is irradiated with radiation.
Ri by the irradiation of the electron beam, which is one of the line, not introduce a cross-linking structure
By that as caulking, resulting fuel barrier properties and gas barrier property, and melt resistant is enhanced effectively
And than become Rukoto, compared with the conventional polyamide resin hose is the have improved properties. Therefore, it has become possible to provide a hose having extremely high utility value as a hose for automobile parts piping that can be used for both the fuel piping system and the refrigerant piping system.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-113885 (JP, A) JP-A-53-88852 (JP, A) JP-A-62-259815 (JP, A) JP-A-61-1987 7336 (JP, A) JP-A-61-278533 (JP, A) JP-A-61-261308 (JP, A) JP-B-2-8606 (JP, B2) JP-B-61-52853 (JP, B2) JP-B-56-54217 (JP, B2) JP-B-46-19543 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 9/00-11/26 C08J 3/28

Claims (1)

(57) [Claims] 1. A consists hose construction of single-layer or multi-layer, and with at least one layer of the hose structure layer is a tree Aburaso, self fuel or refrigerant is caused to flow therein
A method for improving barrier properties of a hose for a vehicle part piping, wherein the resin layer is made of polyamide, polyester, or polystyrene.
, Polyacrylate, polyacrylamide, polychloride
Vinyl, polyvinyl alcohol, polyvinylidene fluoride
Or polyethylene-tetrafluoroethylene copolymer
It is composed of a layer made of coalesced and added with a crosslinking aid.
On the other hand, an electron beam is applied to the resin layer as radiation.
By irradiating it, the resin layer
That a cross-linking structure was introduced between the mer molecules.
How to improve barrier properties of hoses for automotive parts piping
Law.