Plastic and nonmetallic article shaping or treating: processes – Direct application of electrical or wave energy to work – Extrusion molding
Reexamination Certificate
2001-08-29
2004-10-26
Eashoo, Mark (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Direct application of electrical or wave energy to work
Extrusion molding
C264S495000, C264S171130
Reexamination Certificate
active
06808671
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing a fuel hose and an ultraviolet crosslinking composition used therefor, and specifically relates to a method for manufacturing a fuel hose for a car and an ultraviolet crosslinking composition used therefor.
2. Description of the Art
Generally, fuel hoses for cars are roughly divided into rubber hoses having a rubber layer as a base, and resin hoses having a resin layer as a base. Due to their lighter weights, the use of resin hoses has been increasing. An outer peripheral surface of a resin hose has a protector layer (outer skin) to resist the impact of stones and to thereby protect fuel (oil or the like) contained in the hose. A material for forming the protector layer (outer skin) is, for instance, rubber, flexible polyvinyl chloride, various types of thermoplastic elastomers (TPE), or the like.
However, when rubber is used to form a protector layer, hoses cannot be continuously manufactured and the productivity is low due to a batch processing in which rubber is coated on an outer peripheral surface of a resin layer and a hose is subsequently cut therefrom into a predetermined length and then the rubber heated and crosslinked (vulcanized). Moreover, since the resin layer is deformed (molten resin) because of high temperature during the heating and vulcanizing process, the material forming the resin layer is limited to a heat-resistant material, for example, engineering plastic. General-purpose resins such as polyethylene or the like cannot be used, and therefore the costs for the hose are increased.
On the other hand, when flexible polyvinyl chloride or TPE is used to form a protector layer, heating and vulcanizing become unnecessary. It is also unnecessary to cut the hose into a predetermined length in the middle of production. Thus, hoses can be continuously produced, and the productivity is superior. However, since polyvinyl chloride or TPE is not crosslinked, it cannot be used at a temperature higher than its softening point and its heat-resistance is inferior. Moreover, when polyvinyl chloride or TPE is exposed to fire, it liquefies into drops. Thus, not only is its flame resistance low, but it may also cause falling globules of flaming material. If polyvinyl chloride or TPE ignites, an evacuation period would be extremely short. Its dropping-resistance is inferior, which is also troublesome. Additionally, flexible polyvinyl chloride or TPE has a problem in that it has less flexibility than vulcanized rubber.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method for manufacturing a fuel hose that can efficiently produce a heat-resistant and flexible fuel hose and an ultraviolet crosslinking composition used therefor.
In order to achieve the above object, a method for manufacturing a fuel hose according to a first aspect of the present invention forms a protector layer on an outer peripheral surface of a resinous inner layer, the method including the steps of extruding an ultraviolet crosslinking composition for a protector layer which contains the following components A to D, onto the outer peripheral surface of the resinous inner layer; and irradiating ultraviolet rays to polymerize the ultraviolet crosslinking composition, thus forming a protector layer:
(A) ethylene-propylene-diene rubber;
(B) acrylate-based monomer;
(C) silica; and
(D) photopolymerization initiator.
An ultraviolet crosslinking composition for use in the method for manufacturing a fuel hose in the first aspect, according to a second aspect of the present invention, contains the following components A to D:
(A) ethylene-propylene-diene rubber;
(B) acrylate-based monomer;
(C) silica; and
(D) photopolymerization initiator.
In other words, the present inventors repeated thorough studies mostly on a material for forming a protector layer so as to provide an efficient method for manufacturing a heat-resistant and flexible fuel hose. First, they thought that batch processing might become unnecessary and continuous production might be possible as rubber can be vulcanized by ultraviolet irradiation with the use of a photopolymerization initiator. Thus, they further repeated studies mainly on rubber materials. Then, they directed their attention to relatively economical ethylene-propylene-diene rubber (EPDM), among other rubbers, and thought good results might be obtained if both EPDM and an acrylate-based monomer were used and crosslinked by ultraviolet rays after being mixed with a photopolymerization initiator. However, they found that EPDM is not compatible with an acrylate-based monomer, and kneadability is inferior. After further studies, they found that silica absorbs the acrylate-based monomer and shear is likely to be added, thereby shortening kneading time and improving kneadability. Accordingly, they found that the above-noted object can be achieved when an ultraviolet crosslinking composition containing EPDM, acrylate-based monomer, silica and a photopolymerization initiator is used as a material for forming a protector layer and a protector layer is formed by irradiating ultraviolet rays thereto, thereby reaching the present invention.
Acrylate-based monomer includes methacrylic monomer, in addition to acrylic monomer, in the present invention.
Moreover, the kneading of a composition becomes preferable as the mixing ratio of each component in the ultraviolet crosslinking composition is within a predetermined range, thus improving the transparency of the protector layer and the flexibility of the fuel hose.
Furthermore, when a resorcinol-based compound (component E) and melamine resin (component F), in addition to the above-mentioned components A to D, are used together, the resorcinol-based compound (component E) operates mainly as an adhesive. At the same time, the melamine resin (component F) operates mainly as an adhesive aid. Thus, the resinous inner layer can be bonded to the protector layer with further strength, preventing the exposure of a hose end due to the slippage of layers during bend processing or a connector press-in process. Moreover, even when a thin layer is formed by using a material which loses significant mechanical and barrier properties due to moisture, such as polyamide resin, ethylene-vinyl alcohol copolymer (EVOH), metal or the like, on the outer peripheral surface of the resinous inner layer, a fuel hose with excellent adhesive strength between each thin layer and a protector layer can be provided.
The embodiments of the present invention will be explained in detail.
An example of the method of manufacturing a fuel hose of the present invention will be explained based on FIG.
1
. In other words, a resin material is first extruded by an extrusion molding machine
3
and then cooled if necessary, thus forming a resinous inner layer
1
. Then, the subject ultraviolet crosslinking composition
5
is extruded onto the surface of the resinous inner layer
1
by an extrusion molding machine
4
. Subsequently, ultraviolet rays are irradiated from an ultraviolet lamp
6
to polymerize the subject ultraviolet crosslinking composition
5
, thus forming a protector layer
2
. The resultant product is wound into a roll shape. A hose is then cut therefrom into the necessary length, thereby manufacturing a fuel hose as shown in
FIG. 2
in which the protector layer
2
is formed on the outer peripheral surface of the resinous inner layer
1
. In
FIG. 1
, reference numeral
7
indicates a roller.
There is no particular limitation on the material for forming the resinous inner layer
1
. The material may include, for instance, fluorine resin, polyamide resin, polyester resin, polyolefine resin, and the like. The material may be used alone or with two or more kinds of the above.
The fluorine resin may include, for instance, polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrafluoroethylene copolymer (ETFE), hexafluoropropylene-tetrafluoroethylene c
Katayama Kazutaka
Miyahara Naotoshi
Taguchi Takehiko
Armstrong Kratz Quintos Hanson & Brooks, LLP
Eashoo Mark
Tokai Rubber Industries Ltd.
LandOfFree
Method for manufacturing fuel hose and ultraviolet... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for manufacturing fuel hose and ultraviolet..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for manufacturing fuel hose and ultraviolet... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3261592