JP3606213B2 - Resin tube - Google Patents

Description

【００４７】
表１に示した結果から明らかなように、実施例１，２で得られた樹脂製チューブは、いずれも比較例１〜３に対して優れた特性（耐透過性能、剥離強度）が測定された。特に、剥離強度については、測定が極めて困難なものもあり、実施例で得られた樹脂製チューブに係る材料が特別な接着工程を必要とせずに優れた接着性を有することが理解できる。
【００４８】
以上、本発明を実施例により詳細に説明したが、本発明はこれらに限定されるものではなく、本発明の要旨内であれば種々の変形が可能である。
例えば、本発明に使用される各層の材料樹脂には、酸化防止剤や熱安定剤（ヒンダードフェノール、ヒドロキノン、チオエーテル及びホスファイト類、又はこれらの任意の混合物やこれらの置換体等）、紫外線吸収剤（レゾルシノール、サリシレート、ベンゾトリアゾール及びベンゾフェノン等）、滑剤や離型剤（シリコン樹脂、モンタン酸及びこれらの塩、ステアリン酸及びこれらの塩、ステアリルアルコール、ステアリルアミド等）、染料（ニトロシン等）や顔料（硫化カドミウムやフタロシアニン等）を含む着色剤、添加剤添着液（シリコンオイル等）、及び結晶核剤（タルクやカオリン等）などを単独又は適宜組合せて添加することができる。
また、樹脂製チューブの断面形状は、代表的には円形又は楕円形であるが、これら以外の断面形状であってもよい。更に、各層の材料を用いた積層体をチューブ以外の形状、例えば雨どいのような形状やシート形状で使用しても、耐透過性等が得られることは言うまでもない。更にまた、樹脂製チューブは、押出し成形により容易に製造できるブロー成形、コルゲート形状の付与（蛇腹化）等も適用できる。
【００４９】
【発明の効果】
以上説明してきたように、本発明によれば、所定の樹脂を用いた積層構造とすることとしたため、通常のガソリンの他に含アルコール燃料に対しても低い透過性を有し、バリア層（燃料遮断層）と被覆層（燃料遮断層を保護する層）との接着性が十分高く、端材等の再利用が容易で安価な材料構成である樹脂製チューブを提供することができる。
【００５０】
【図面の簡単な説明】
【図１】樹脂製チューブの一例（２層構造）を示す概略図である。
【図２】樹脂製チューブの一例（３層構造）を示す概略図である。
【図３】樹脂製チューブの一例（５層構造）を示す概略図である。
【符号の説明】
１０、２０、３０ 樹脂製チューブ
２ａ、２ｂ 燃料遮断層
３ａ、３ｂ、３ｃ 被覆層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin tube, and more specifically, is formed by laminating resin layers, and is lightweight, rust-proof, excellent delamination resistance in a high temperature atmosphere, and high fuel barrier property (fuel impermeability). And a resin tube that can be easily reused.
Further, the resin tube of the present invention can be suitably used as a tube for fuel system piping of automobiles.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, a fuel system piping of an automobile such as a feed tube, a return tube, an evaporation hose and a filler hose has been made of metal, rubber, resin, or a pipe structure in which two to three of these are mixed. Yes. In recent years, in particular, instead of metal products, which have been the mainstream so far, it has been cut into resin products because it does not generate rust, can be reduced in weight, and is advantageous in terms of cost. It is changing.
However, in general, resin-made ones have the disadvantage of being inferior in fuel permeation resistance compared to metal ones, and it is strongly recommended to suppress the permeation of fuel evaporation regulations, which are expected to become increasingly severe in the future. It is requested.
[0003]
Although various developments aimed at improving the fuel permeation resistance of resin pipes and the like have been reported, the permeability to alcohol-containing fuels is low, and it is realistic in terms of materials and production. No inexpensive configuration has been reported.
For example, in JP-A-5-164273, etc., a fluororesin (ethylene / tetrafluoroethylene copolymer) is used for the inner layer (barrier layer), an adhesive layer is provided for the intermediate layer, and polyamide 12 is used for the outer layer. A configuration is proposed.
However, in this case, there are problems that the fluororesin itself is expensive and that the adhesive layer for bonding the fluororesin and the outer polyamide 12 is expensive.
[0004]
On the other hand, in order to suppress the material cost, it is considered to reduce the thickness of the layer containing the fluororesin, but because sufficient pressure resistance cannot be ensured, it is difficult to reduce the thickness sufficiently and cost reduction cannot be achieved. .
In addition, in order to obtain stronger adhesion, when a surface treatment to introduce an active group by applying a chemical treatment liquid containing sodium-ammonia complex on the surface by extruding a fluororesin as an inner layer, The manufacturing process becomes extremely complicated and the cost is further increased.
[0005]
On the other hand, Japanese Patent Application Laid-Open No. 11-156970 proposes a configuration in which polyphenylene sulfide (PPS) is applied to the barrier layer.
However, even in this case, there is a problem that it is necessary to provide an adhesive layer and that the PPS layer and the adhesive layer are expensive. hard.
[0006]
These problems are caused by using different materials for the barrier layer and the protective layer (outer layer) in any case. In other words, when different materials are combined, an adhesive layer is required because strong adhesiveness cannot be obtained as it is, and at least a three-layer structure is required. Also, since the adhesive layer itself is expensive, piping (laminated tube) ) Inevitably becomes expensive.
[0007]
JP-A-10-30764 and JP-A-2000-55248 propose a method of bonding a barrier layer (inner layer) and a protective layer (outer layer) by surface treatment such as plasma without providing an adhesive layer. Yes.
However, the manufacturing process becomes complicated, and it is difficult to be a fundamental solution to the above problem. In addition, in such a combination of different materials, it is extremely difficult to reuse the end material in the process, which is also a big problem.
[0008]
The present invention has been made in view of such problems of the prior art, and an object of the present invention is to have low permeability to alcohol-containing fuels in addition to ordinary gasoline, and a barrier layer. An object of the present invention is to provide a resin tube having a sufficiently high adhesiveness between the (fuel barrier layer) and the coating layer (the layer that protects the fuel barrier layer) and having a material configuration that is easy to reuse, such as mill ends.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by forming a laminated structure using a predetermined resin, and have completed the present invention.
[0010]
That is, the resin tube of the present invention is a resin tube in which two or more resin layers are laminated in a tubular shape,
At least one layer is a resin layer mainly composed of polyphenylene sulfide, and the other layers are resin layers mainly composed of a polybutylene terephthalate copolymer,
Of the resin layer mainly composed of the polybutylene terephthalate copolymer, the layer in contact with the resin layer mainly composed of the polyphenylene sulfide further comprises polyphenylene sulfide.
[0011]
Another resin tube of the present invention is a resin tube in which two or more resin layers are laminated in a tubular shape,
At least one layer is a resin layer mainly composed of polyphenylene sulfide, and the other layers are resin layers mainly composed of a polybutylene terephthalate copolymer,
The resin layer containing polyphenylene sulfide as a main component further comprises a polybutylene terephthalate copolymer.
[0012]
Furthermore, still another resin tube of the present invention is a resin tube in which three or more resin layers are laminated in a tubular shape,
At least one set of resin layers mainly composed of polyphenylene sulfide which is not in contact with each other and resin layers mainly composed of polybutylene terephthalate, and the other layers are composed mainly of polybutylene terephthalate copolymer. It is characterized by comprising.
[0014]
In another preferred embodiment of the resin tube of the present invention, the polybutylene terephthalate copolymer is a polyester / ether block copolymer elastomer comprising polybutylene terephthalate as a hard segment and polyether as a soft segment. It is characterized by.
[0015]
Furthermore, in another preferred embodiment of the resin tube of the present invention, the polybutylene terephthalate copolymer is a polyester / ester block copolymer elastomer comprising polybutylene terephthalate as a hard segment and polyester as a soft segment. It is characterized by.
[0016]
Furthermore, in another preferred embodiment of the resin tube of the present invention, the polybutylene terephthalate copolymer contains terephthalic acid or an ester-forming derivative thereof and a hydrogenated dimer acid or an ester-forming derivative thereof as an acid component. Copolyester containing 1,4-butanediol as a glycol component is the main constituent.
[0017]
Still another preferred embodiment of the resin tube of the present invention is characterized in that at least a part of the terephthalic acid unit constituting the polybutylene terephthalate copolymer is substituted with a naphthalenedicarboxylic acid unit.
[0018]
Hereinafter, the resin tube of the present invention will be described in detail. In the present specification, “%” indicates a mass percentage unless otherwise specified.
As described above, the resin tube of the present invention is formed by laminating two or more resin layers into a tubular shape, and includes a resin layer mainly composed of polyphenylene sulfide (PPS) and a polybutylene terephthalate copolymer (PBT copolymer). And a resin layer containing as a main component.
[0019]
Here, the resin layer containing PPS as a main component has a low fuel permeability and functions as a layer that blocks permeation (hereinafter, this layer is referred to as a “fuel blocking layer”).
Further, the layer containing the PBT copolymer as a main component has a function as a coating layer that covers and protects the fuel cutoff layer (hereinafter, this layer is referred to as a “coating layer”).
Specifically, as shown in FIG. 1, a resin tube 10 in which a coating layer 3a is coated on the outer periphery of a fuel cutoff layer 2a having a hollow portion through which fuel or the like can flow in the center, or as shown in FIG. Further, a resin tube 20 in which a coating layer 3b is further coated on the inner periphery of the tube having the same configuration as that of the resin tube 10, or a tube having the same configuration as the resin tube 20 as shown in FIG. A resin tube 30 and the like in which the fuel cutoff layer 2b and the coating layer 3c are further coated in this order on the inner periphery of the cylinder can be exemplified.
The resin tube of the present invention is not limited to the 2-5 layer structure as shown in FIGS. 1-3, and it goes without saying that a plurality of fuel blocking layers and coating layers may be further coated. Further, the above “main component” means that 50% or more of the material is contained in the resin layer, although it varies depending on the material.
[0020]
Moreover, the fuel barrier layer has PPS as a main component, so that even if a mixed fuel containing alcohol such as ethanol or methanol is circulated in the resin tube in addition to ordinary gasoline fuel, excellent permeation resistance Have
Further, in both cases where the fuel cutoff layer 2a is in contact with the fuel as shown in FIG. 1 and in the case where the coating layer is in contact with the fuel as shown in FIG. 2 and FIG. 3, it depends on the amine-based detergent contained in the fuel. Deterioration is extremely small, and it has excellent resistance to sour gasoline (deteriorated gasoline).
Furthermore, any of the fuel blocking layer and the coating layer may be used as the innermost layer, and the sealability with metal or the like can be remarkably improved. It is hard to slip even if inserted.
[0021]
In addition to the resin layer mainly composed of PPS, a resin layer mainly composed of PBT can be laminated as the fuel cutoff layer. In this case, it is possible to obtain a high fuel cut-off property at low cost, which is effective. However, PBT and PPS have extremely low adhesiveness, and these laminates may cause problems in practical use. Therefore, the resin tube is formed by laminating three or more resin layers into a tubular shape, and at least one set It has a resin layer mainly composed of PPS and a resin layer mainly composed of PBT which are not in contact with each other, and the other layers are composed of a PBT copolymer. In this case, the layers are laminated with a high adhesive force through a resin layer mainly composed of a PBT copolymer.
[0022]
Furthermore, the fuel barrier layer has a better fuel barrier property as the PPS content increases. However, the fuel barrier layer contains a slight amount of PBT copolymer, so that a coating layer that is laminated or laminated (a PBT copolymer is mainly used). Adhesion with component) is improved. From this, when the adhesiveness outstanding between layers is requested | required, it is desirable to adjust content of a PBT copolymer suitably.
Since PPS has a solubility coefficient close to that of polyamides and is excellent in miscibility, polyamide resins such as polyamide 6 and polyamide 66 can be mixed in the fuel cutoff layer. In this case, the material configuration can be reduced.
[0023]
Furthermore, since the coating layer has a PBT copolymer as a main component, the coating layer exhibits high miscibility with the fuel cutoff layer (PPS or PBT), and has sufficient adhesion only by coextrusion. Ensures excellent delamination even in high temperature atmospheres. In other words, sufficient adhesive force can be imparted without providing an adhesive layer between the coating layer and the fuel cutoff layer. In addition, since a high adhesive force is exhibited, extrusion during molding can be performed quickly, and tact time can be shortened. Further, for the same reason as the fuel cutoff layer, the inclusion of PPS in the coating layer improves the interlayer adhesion, and it is not necessary to provide an adhesion layer between the fuel cutoff layer and the coating layer, and the resin is extremely inexpensive. A tube made can be obtained.
[0024]
The PBT copolymer has excellent flexibility and can effectively function as a coating layer for protecting the fuel cutoff layer (for example, preventing the strength of the fuel cutoff layer from being damaged or preventing damage). For example, when the resin tube is attached to a vehicle or the like as a fuel tube, it can be bent and easily disposed. At this time, since the coating layer may be in contact with the fuel in a small amount, it is desirable that the coating layer has resistance to the fuel.
Since the PBT copolymer has PBT in the basic skeleton, it has flexibility required as a coating layer and also has resistance to fuel.
In addition, since PBT has a low glass transition point (about 20 ° C.), the PBT copolymer can easily obtain a low glass transition point, and is excellent even at a low temperature of −40 ° C. required for vehicles and the like. Can have flexibility. In addition, the flexibility of the coating layer is preferably 1.5 GPa or less, particularly 1.0 GPa or less in terms of the flexural modulus at room temperature, for a resin tube having an outer diameter of φ8 mm and a wall thickness of about 1 mm. desirable.
[0025]
Furthermore, the segment in the PBT copolymer may be composed of either a block type (block type PBT copolymer) or a random type (random type PBT copolymer).
[0026]
That is, when the PBT copolymer is a block type, the hard segment is PBT, the soft segment is polytetramethylene glycol, polyhexamethylene glycol, etc. from the viewpoint of market availability and low temperature flexibility. Polyester, such as polyether, adipic acid ester such as ethylene adipate and butylene adipate, polycaprolactone, polyvalerolactone and aliphatic polycarbonate can be used.
Typically, it is preferable to use a polyester / ether block copolymer elastomer having PBT as a hard segment and polyether as a soft segment, from the viewpoints of stability of physical properties from low temperature to high temperature, processability and flexibility. . At this time, the polyether is more preferably polytetramethylene glycol.
For the same reason, it is preferable to use a polyester / ester copolymer elastomer having PBT as a hard segment and polyester as a soft segment. At this time, the polyester is more preferably polycaprolactone.
[0027]
On the other hand, when the PBT copolymer is a random type, it is preferable to include a dicarboxylic acid component and a glycol component as main components from the viewpoint that one of the polymerization steps can be omitted compared to the block type.
Typically, it is a PBT copolymer containing terephthalic acid or an ester-forming derivative thereof and hydrogenated dimer acid or an ester-forming derivative thereof as the dicarboxylic acid component, and 1,4-butanediol as the glycol component. It is preferable. Moreover, it is preferable that the copolymerization composition of the said hydrogenation dimer acid is a ratio of 3-30 mol% with respect to all the acid components, and the flexibility at low temperature is obtained and workability can be improved. If the amount is outside this range, sufficient flexibility may not be obtained after forming the tube, and sufficient “waist” may not be obtained. Further, the 1,4-butanediol is desirably used in an amount of 70 mol% or more from the viewpoint of improving the molecular weight.
[0028]
Examples of the ester-forming derivative include dimethyl terephthalate. Furthermore, the hydrogenated dimer acid is obtained after separating and hydrogenating unsaturated fatty acid from the low polymer using a viscosity catalyst to remove by-products such as trimer acid and monomer acid. At this time, the purity of the hydrogenated dimer acid is desirably 99% or more.
Other examples of the acid component include isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, sebacic acid and adipic acid. Aromatic or aliphatic can be mentioned, and these can be used in combination as appropriate.
[0029]
As described above, whether the PBT copolymer is a block type or a random type, since the melting temperature of the fuel barrier layer material and the coating layer material is close, the resin tube is extruded using the same crosshead. It is easy to mold. Moreover, since it has miscibility between the fuel barrier layer and the coating layer, high adhesion can be imparted between the layers.
[0030]
In addition, the constituent material of the fuel barrier layer and the coating layer described above does not need to be special and can be easily obtained on the market. Moreover, according to a request | requirement suitably, heat resistance and hydrolysis resistance can be provided, a filler etc. can be mixed, electroconductivity can be provided, an inorganic material etc. can be mixed and strengthened.
[0031]
Moreover, the layer thickness ratio of each layer is not specifically limited, A resin-made tube can be suitably manufactured with a desired thickness ratio. In particular, from the viewpoint of stability during extrusion molding, the thickness of each of the above layers is preferably 10% or more with respect to the total thickness (thickness of the resin tube), and the fuel cutoff layer is protected. From the viewpoint of the above and from the viewpoint of maintaining appropriate flexibility, it is desirable that the layer thickness retention ratio of the coating layer is 40 to 90% of the total layer thickness.
For example, a three-layer tube as shown in FIG. 2 can have a layer structure of 0.1 mm, 0.3 mm, and 0.6 mm from the inner layer side. The outer diameter of the resin tube is typically about 3 to 20 mm, although it varies depending on the type of distribution medium.
[0032]
Furthermore, since the materials having high miscibility are combined, not only an adhesive is not required at the time of forming the tube, but also it can be reused very easily.
For example, mill ends that are produced during the manufacturing process and fuel tubes that are no longer needed can be simultaneously pulverized and remelted without separating the layers and reused in desired resin parts.
[0033]
Furthermore, in the resin tube of the present invention, at least a part of the terephthalic acid unit constituting the PBT copolymer can be replaced with a naphthalenedicarboxylic acid unit. In this case, the solubility coefficient of the copolymer is increased, and adhesion with a resin layer containing PPS as a main component or a resin layer containing PBT as a main component can be further improved, and the fuel blocking property can be improved. In addition, since the solubility coefficient of the copolymer can be made close to PPS according to the amount of the naphthalenedicarboxylic acid unit mixed, or the fuel shut-off property can be improved, the amount mixed is preferably adjusted according to the desired characteristics. When all of the terephthalic acid unit is replaced with naphthalenedicarboxylic acid, a PBN copolymer is obtained, and at this time, the adhesiveness and the fuel cutoff are particularly excellent. Moreover, as said naphthalene dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,5-dicarboxylic acid, etc. can be used.
[0034]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.
[0035]
[Performance evaluation method]
A laminated tube (single layer only in Comparative Example 2) was molded with the layer structure shown in Examples 1 and 2, Comparative Examples 1 to 3 and Reference Examples 1 to 5, and a 1-inch wide test piece was collected from the molded product. Then, a 180 ° peel test of JIS-K6301 was performed.
Further, a material having the same structure as that of the laminated tube was extruded into a flat plate shape, and a permeation resistance test was performed using the extrudate. Here, permeation resistance was measured by the amount of gasoline or alcohol-containing fuel permeated in a 60 ° C. atmosphere and after a specified time into a sample punched out into a disk shape of φ70 mm. These results are shown in Table 1.
The gasoline used was commercially available regular gasoline, and the alcohol-containing fuel was a mixture of 90 parts by volume of regular gasoline and 10 parts by volume of ethanol. In Table 1, ◎, ○, Δ and × are relative evaluations when the result of Comparative Example 1 is ○, ◎ is better than this, ○ is equivalent, △ is slightly Inferior ones and x indicate extremely inferior ones.
[0036]
(Reference Example 1)
PPS resin (made by Toray Industries, Inc .; A670X01) is used as the inner layer, and PBT copolymer (polyester / ether block copolymer elastomer, manufactured by Toray DuPont, Inc .; Hytrel 5577) is extruded at a volume ratio of 3: 7 in this example. Resin tubes (extruded outer diameter 8 mm, inner diameter 6 mm) and a flat plate (1 mm thickness) were obtained.
[0037]
(Reference Example 2)
The same operation as in Reference Example 1 was repeated except that the PBT copolymer of the outer layer was changed to another PBT copolymer (polyester / ester block copolymer elastomer, manufactured by Toyobo Co., Ltd .; Perprene S-3001). Example resin tubes and flat plates were obtained.
[0038]
(Reference Example 3)
The same procedure as in Reference Example 1 was repeated except that the outer layer PBT copolymer was changed to another PBT copolymer (random polyester copolymer, manufactured by Kanebo Gosei Co., Ltd .; Perprene P02121). A tube and a flat plate were obtained.
[0039]
Example 1
Except that the PPS of the inner layer was changed to a mixture of PPS and PBT copolymer (weight ratio 90:10), the same operation as in Reference Example 1 was repeated to obtain a resin tube and a flat plate of this example.
[0040]
(Reference Example 4)
A PBT copolymer (polyester / ether block copolymer elastomer, manufactured by Toray DuPont Co., Ltd .; Hytrel 7277) is laminated on the inner periphery of the PPS of the intermediate layer, and the inner layer: intermediate layer: outer layer has a volume ratio of 1: 3. The resin tube and the flat plate of this example were obtained by repeating the same operation as in Reference Example 1 except that the ratio was changed to 6.
[0041]
(Reference Example 5)
The same operation as in Reference Example 1 was performed except that a PBT copolymer (in-house prototype) was laminated as the inner layer on the inner periphery of the PPS of the intermediate layer, and the inner layer: intermediate layer: outer layer was set to a volume ratio of 1: 3: 6. The resin tube and flat plate of this example were obtained by repeating.
[0042]
(Example 2)
From the inner layer side, the innermost layer is PBT copolymer (polyester / ether block copolymer elastomer, manufactured by Toray DuPont Co., Ltd .; Hytrel 5577), the inner layer is PPS (manufactured by Toray Industries, Inc .; A670X01), and the intermediate layer is PBT copolymer. Copolymer (polyester / ether block copolymer elastomer, manufactured by Toray DuPont Co., Ltd .; Hytrel 5577), PBT (Kanebo Gosei Co., Ltd .: PBT719) as the outer layer, and PBT copolymer (polyester / ether block copolymer as the outermost layer) The same as Reference Example 1 except that an elastomer, manufactured by Toray DuPont Co., Ltd .: Hytrel 5577) was laminated and the innermost layer: inner layer: intermediate layer: outer layer: outermost layer was changed to a volume ratio of 1: 1: 1: 3: 4. These operations were repeated to obtain a resin tube and a flat plate of this example.
[0043]
(Comparative Example 1)
An ethylene tetrafluoroethylene copolymer (ETFE) is used for the inner layer, a mixture of ETFE and polyamide 12 (PA12) is used for the intermediate layer, and PA12 is used for the outer layer. Inner layer: intermediate layer: volume ratio of outer layer = 1.5: 1.5: 7 to obtain a resin tube (extruded outer diameter 8 mm, inner diameter 6 mm) and a flat plate (1 mm thickness) of this example. The peel strength is a measurement result at the interface between the inner layer and the intermediate layer.
[0044]
(Comparative Example 2)
A resin tube of this example, that is, a single-layer tube (extruded outer diameter 8 mm, inner diameter 6 mm) and a flat plate (1 mm thickness) were obtained only from polyamide 11 (PA11).
[0045]
(Comparative Example 3)
Except that the PBT copolymer of the outer layer was changed to PBT (5201-X10), the same operation as in Example 1 was repeated to obtain a resin tube and a flat plate of this example.
[0046]
[Table 1]

[0047]
As is clear from the results shown in Table 1, the resin tubes obtained in Examples 1 and 2 were measured for excellent properties (permeation resistance, peel strength) relative to Comparative Examples 1 to 3. It was. In particular, regarding the peel strength, there are some which are extremely difficult to measure, and it can be understood that the material according to the resin tube obtained in the example has excellent adhesiveness without requiring a special bonding step.
[0048]
As mentioned above, although this invention was demonstrated in detail by the Example, this invention is not limited to these, A various deformation | transformation is possible if it is in the summary of this invention.
For example, the material resin of each layer used in the present invention includes antioxidants and heat stabilizers (hindered phenols, hydroquinones, thioethers and phosphites, or any mixture or substitution thereof), ultraviolet rays, and the like. Absorbent (resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricant and mold release agent (silicon resin, montanic acid and salts thereof, stearic acid and salts thereof, stearyl alcohol, stearylamide, etc.), dye (nitrosine, etc.) And coloring agents including pigments (cadmium sulfide, phthalocyanine, etc.), additive additives (silicon oil, etc.), crystal nucleating agents (talc, kaolin, etc.) and the like can be added alone or in appropriate combination.
The cross-sectional shape of the resin tube is typically circular or elliptical, but may be other cross-sectional shapes. Furthermore, it goes without saying that permeation resistance and the like can be obtained even if the laminate using the material of each layer is used in a shape other than a tube, such as a gutter shape or a sheet shape. Furthermore, the resin tube can be applied to blow molding that can be easily manufactured by extrusion molding, corrugated shape imparting (bellowing), or the like.
[0049]
【The invention's effect】
As described above, according to the present invention, since a laminated structure using a predetermined resin is adopted, it has low permeability to alcohol-containing fuels in addition to ordinary gasoline, and a barrier layer ( It is possible to provide a resin tube having a sufficiently high adhesiveness between the fuel cutoff layer) and the coating layer (a layer that protects the fuel cutoff layer), which is easy to reuse, such as scrap materials, and is inexpensive.
[0050]
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a resin tube (two-layer structure).
FIG. 2 is a schematic view showing an example (three-layer structure) of a resin tube.
FIG. 3 is a schematic view showing an example (five-layer structure) of a resin tube.
[Explanation of symbols]
10, 20, 30 Resin tube 2a, 2b Fuel blocking layer 3a, 3b, 3c Coating layer

Claims (10)

Two or more resin layers are resin tubes formed in a tubular shape,
At least one layer is a resin layer mainly composed of polyphenylene sulfide, and the other layers are resin layers mainly composed of a polybutylene terephthalate copolymer,
A resin tube characterized in that, among the resin layers mainly composed of the polybutylene terephthalate copolymer, the layer in contact with the resin layer mainly composed of the polyphenylene sulfide further comprises polyphenylene sulfide. Two or more resin layers are resin tubes formed in a tubular shape,
At least one layer is a resin layer mainly composed of polyphenylene sulfide, and the other layers are resin layers mainly composed of a polybutylene terephthalate copolymer,
A resin tube, wherein the resin layer containing polyphenylene sulfide as a main component further comprises a polybutylene terephthalate copolymer. Three or more resin layers are resin tubes formed in a tubular shape,
At least one set of a resin layer mainly composed of polyphenylene sulfide which is not in contact with each other and a resin layer mainly composed of polybutylene terephthalate, and the other layers are composed mainly of a polybutylene terephthalate copolymer. A resin tube characterized by comprising: The polybutylene terephthalate copolymer is a polyester / ether block copolymer elastomer comprising polybutylene terephthalate as a hard segment and polyether as a soft segment. The resin tube described in 1. The resin-made tube according to claim 4, wherein the polyether is polytetramethylene glycol. The polybutylene terephthalate copolymer is a polyester / ester block copolymer elastomer comprising polybutylene terephthalate as a hard segment and polyester as a soft segment, according to any one of claims 1 to 5, The resin tube described. 7. The resin tube according to claim 6, wherein the polyester is polycaprolactone. The polybutylene terephthalate copolymer comprises terephthalic acid or an ester-forming derivative thereof as an acid component and a hydrogenated dimer acid or an ester-forming derivative thereof, and a copolyester containing 1,4-butanediol as a glycol component. The resin tube according to any one of claims 1 to 3, wherein the resin tube is a main component. The resin-made tube according to claim 8, wherein the copolymerization composition of the hydrogenated dimer acid is 3 to 30 mol% with respect to the total acid component. The resin tube according to any one of claims 1 to 9, wherein at least a part of a terephthalic acid unit constituting the polybutylene terephthalate copolymer is substituted with a naphthalenedicarboxylic acid unit. .

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