WO2021137612A1

WO2021137612A1 - Composition for fuel tube, composite material comprising composition, and fuel tube using same

Info

Publication number: WO2021137612A1
Application number: PCT/KR2020/019378
Authority: WO
Inventors: 이상우; 조신제; 신봉선; 김승현
Original assignee: 한화솔루션 주식회사
Priority date: 2019-12-30
Filing date: 2020-12-30
Publication date: 2021-07-08

Abstract

The present invention relates to: a composition, for a fuel tube, comprising polyamide 12 resin (PA12); a composite material comprising the composition as an inner layer; and a fuel tube using same and, particularly, to a technique that can reduce and prevent the release of unreacted oligomers and monomers of PA12 and a plasticizer by an automotive fuel in the long-time use of the fuel tube, achieve the enhancement in chemical resistance and mechanical properties, and improve the processability and the interlayer adhesiveness of the tube. To this end, the present invention may comprise an antioxidant, a plasticizer, and a flow improver in PA11.

Description

Composition for fuel tube, composite material containing the composition, and fuel tube using the same

The present invention relates to a composition for a fuel tube comprising polyamide 12 resin (PA12), a composite material comprising the composition as an inner layer, and a fuel tube using the same, and more particularly, to PA12, an antioxidant, a plasticizer, and a fluidity improving agent. A composition, a composite material, and a fuel tube using the same to improve mechanical properties of a fuel tube by adding it to prepare a composition, and including it as an inner layer of a composite material for a fuel tube, and to suppress elution by fuel when using the fuel tube is about

A fuel tube refers to a tube that supplies fuel such as gasoline or diesel in an internal combustion engine of a vehicle. Such a fuel tube can be manufactured using PA12, which is a linear aliphatic polyamide, which has a relatively low density, and has advantages such as chemical resistance, water resistance, cold resistance (-50°C), abrasion resistance, high elasticity, etc. It is widely used as a coating material for fuel tubes, vacuum tubes, hydraulic tubes, and brake pipes in the industrial field.

However, the conventional fuel tube has a problem in that unreacted oligomers, monomers, and plasticizers of PA12 are eluted by the vehicle fuel during long-term use. Therefore, in order to prevent this, a tube having a multi-layer structure has been developed and used.

In the conventional multi-layered tube, PA12 is used for the outer layer, EVOH is used for the middle layer, and a fluororesin such as ETFE (Ethylene Tetra Fluoro Ethylene) is used for the inner layer in many cases. However, when the constituent materials of the outer layer and the inner layer are different, there may be a problem of increasing the cost, and there is a problem of reduced processability and interlayer adhesion compared to the case of manufacturing based on the same resin.

Korean Patent Registration No. 10-150004, which is a prior document, discloses a configuration using polyamide 12, but adding an additive such as an impact modifier, and including a polyamide/polyolefin/nanoclay composite material for the outer layer of an automobile fuel tube. . In particular, it comprises an impact modifier containing an ethylene-a-olefin copolymer grafted with maleic anhydride, a reaction control agent containing a polystyrene resin grafted with maleic anhydride, and nanoclay as an inorganic filler. By adopting this configuration, the composite material has improved mechanical properties such as impact resistance, tensile strength, flexural strength, and thermal stability, but there are still limitations in interlayer adhesion and workability. There is a limitation in that a solution to the problem of eluting monomers and the like has not been presented.

As another prior document, Korean Patent No. 10-0728090 discloses a composition for a conductive composite composition having excellent conductivity and compatibility. That is, by using a mixture of carbon black and carbon nanotubes in a base resin selected from the group consisting of polyamide resin, polyolefin resin, polyester resin, polyolefin-based thermoplastic elastomer resin, olefin-based copolymer, and combinations thereof, fuel transportation A composition that improves the appearance of the product by reducing the amount of conductive filler used when manufacturing a tube, prevents static electricity by expressing improved electrical conductivity, and improves physical properties such as gasoline resistance, tensile strength, impact strength, and moldability is starting However, even in this case, the effect on the improvement of interlayer adhesion or workability is insignificant, and in particular, there is a limitation in that it is difficult to expect the effect of preventing the elution of unreacted oligomers or monomers by automobile fuel during long-term use.

Therefore, there is a need to develop a composite material for a fuel tube and a composition forming the same, which can improve the above problems in consideration of the mechanical properties, durability, and economic feasibility of the fuel tube.

[Prior art literature]

[Patent Literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-1118818

(Patent Document 2) Republic of Korea Patent Publication No. 10-150004

(Patent Document 3) Republic of Korea Patent Publication No. 10-0728090

An object of the present invention is to solve all of the above problems.

An object of the present invention is to reduce or prevent the elution of unreacted oligomers, monomers and plasticizers of PA12 by automobile fuel during long-term use of a fuel tube.

An object of the present invention is to improve chemical resistance and mechanical properties of a composite material constituting a fuel tube.

An object of the present invention is to reduce the cost by manufacturing the material used for the inner layer and the material used for the outer layer based on the same resin, and to improve the multilayer tube coextrusion processability and the interlayer adhesion of the tube.

As a technical means for achieving the above-described technical problem, an aspect of the present invention is

A composition for a fuel tube comprising a polyamide 12 resin with an antioxidant, a plasticizer and a flow improver is provided.

The polyamide 12 resin may have a weight average molecular weight of 45,000 to 100,000.

The antioxidant may include a material selected from the group consisting of disubstituted phenols, phenyl phosphites, hydroperoxide decomposers, sterically hindered phenols, and combinations thereof.

The plasticizer may include a material selected from the group consisting of sulfonamide series, benzoate series, phthalate series, and combinations thereof.

The fluidity improving agent is a long-chain aliphatic carboxylic acid having 12 or more carbon atoms, a derivative of a long-chain aliphatic carboxylic acid having 12 or more carbon atoms, a higher aliphatic alcohol having 12 or more carbon atoms, a derivative of a higher aliphatic alcohol having 12 or more carbon atoms, polypropylene wax, amide wax, polysiloxane, perfluorinated polyether, It may include a material selected from the group consisting of oxidized high-density polyethylene, fluorine-based resin, molybdenum disulfide, dendrimers, and combinations thereof.

Based on 100 parts by weight of the polyamide 12 resin, the content of the antioxidant is 1 part by weight to 5 parts by weight, the content of the plasticizer is 3 parts by weight to 15 parts by weight, and the content of the fluidity improving agent is 0.1 parts by weight to 5 parts by weight It may be parts by weight.

The composition for the fuel tube may further include an impact modifier and a chain extender.

The impact modifier is ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-octene rubber, butadiene rubber, high-density polyethylene, styrene-ethylene/butene rubber, acrylate rubber, maleic anhydride graft-polymerized It may include a material selected from the group consisting of ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-octene rubber, styrene-ethylene/butene rubber, and combinations thereof.

The chain extender is bislactam, bisoxazoline, bisoxazine, bisoxazolinone, bisepoxide, phosphide, phosphite, diisocyanate, dicyanate, dianhydride, bisketenimine, ethylene male It may include a material selected from the group consisting of an acid anhydride copolymer, a styrene maleic anhydride copolymer series, and combinations thereof.

Based on 100 parts by weight of the polyamide 12 resin, the content of the impact modifier may be 3 parts by weight to 15 parts by weight, and the content of the chain extender may be 0.1 parts by weight to 5 parts by weight.

The composition for fuel tube may further include a material selected from the group consisting of a capping agent, a conductive agent, a stabilizer, and combinations thereof.

The capping agent may include a material selected from the group consisting of acetic anhydride, phthalic anhydride, hexamethyldisilazane, acetic acid, cyclohexylamine, and combinations thereof.

The conductive agent may include a material selected from the group consisting of carbon nanotubes, carbon black, carbon fibers, and combinations thereof.

The stabilizer may include a material selected from the group consisting of phosphites, sterically hindered phenols, secondary amines, UV absorbers, HALS stabilizers, metal salts, and combinations thereof.

Based on 100 parts by weight of the polyamide 12 resin, the content of the capping agent is 0.1 parts by weight to 4 parts by weight, the content of the conductive agent is 0.1 parts by weight to 10 parts by weight, and the content of the stabilizer is 0.002 parts by weight to 0.002 parts by weight It may be 1 part by weight.

In addition, another aspect of the present invention,

an outer layer comprising polyamide 12 resin; an intermediate layer comprising ethylene vinyl alcohol; and an inner layer comprising a polyamide 12 resin.

The inner layer may include an antioxidant, a plasticizer, and a fluidity improving agent in the polyamide 12 resin.

The inner layer may further include an impact modifier and a chain extender.

The inner layer may further include a material selected from the group consisting of a capping agent, a conductive agent, a stabilizer, and combinations thereof.

In addition, another aspect of the present invention,

It provides a fuel tube comprising the multilayer composite material for the fuel tube.

The composition for a fuel tube according to the present invention, a composite material comprising the composition, and a fuel tube using the same can reduce or prevent the elution of unreacted oligomers, monomers and plasticizers of PA12 by automobile fuels during long-term use.

In addition, chemical resistance and mechanical properties may be improved, and multilayer tube coextrusion processability and interlayer adhesion of the tube may be improved.

In addition, since the material used for the inner layer and the outer layer is manufactured based on the same resin, the cost can be reduced.

1 shows a multi-layered structure of a conventional fuel tube.

2 shows a multi-layered structure of a fuel tube according to the present invention.

3 is a graph showing GC/MS results after immersion in a test fuel of a composition for a fuel tube according to an embodiment of the present invention.

4 is a graph showing GC/MS results after immersion in a test fuel of a composition for a fuel tube according to another embodiment of the present invention.

5 is a graph showing GC/MS results after immersion in a test fuel of a composition for a fuel tube according to a comparative example of the present invention.

The inventor can select or define appropriate terms or words in describing the invention, and in this case, the terms or words used are not limited to the meanings commonly used, but rather the intention of the inventor is taken into consideration. It should be interpreted to conform to the technical idea embodied in the invention.

Accordingly, the terms or words used in the present specification and claims cannot be regarded as being limited to their commonly used meanings. The above-described content is merely a preferred embodiment of the present invention, and will not represent or limit all of the present technical idea, so there may be examples corresponding to easily replaceable elements and equivalent ranges from the standpoint of those skilled in the art.

Hereinafter, a composition for a fuel tube according to the present invention, a composite material including the composition, and a fuel tube using the composition according to the present invention will be described in detail based on the above-described principle.

Polyamide 12 resin (Polyamide 12, PA12, Polyamide 12, Polyamide 12, hereinafter referred to as PA12) is a linear aliphatic polyamide with an amide bond (-NHCO-) and contains 12 carbons per unit. There is resin

PA12 has a relatively low density (1.02 g/cm ³ ) and has excellent impact resistance due to low sensitivity to stress cracking. In addition, it has excellent water resistance with a water absorption rate of 0.7%, and features such as cold resistance (-50℃), high elasticity, high chemical and abrasion resistance, and excellent barrier properties against aromatic components, such as fuel tube, vacuum tube, It has an advantage in being used as a coating material for hydraulic tubes and brake pipes.

However, there is a problem in that unreacted oligomers, monomers and plasticizers of PA12 are eluted by automobile fuel during long-term use as a fuel tube. In order to prevent this, a tube with a multi-layer structure has been developed and used.

As shown in Figure 1, the conventional multi-layered tube has an outer layer including PA12, an intermediate layer including EVOH (Ethylene Vinyl Alcohol, ethylene vinyl alcohol), and ETFE (Ethylene Tetra Fluoro Ethylene, ethylene tetrafluoroethylene) including It consists of an inner layer, and each layer uses a multi-layer structure that is adhered through a PA (Polyamide) adhesive.

However, in the case of composing the inner layer including ETFE, PA12 forming the outer layer and the base of the resin are different, so there is a problem in that the coextrusion processability of the tube of a multilayer structure and the interlayer adhesion are reduced, and the cost is increased.

Therefore, the present invention proposes a composition including a composite material constituting the inner layer of a fuel tube and PA12 constituting the composite material. It is possible to propose a fuel tube that prevents elution of unreacted oligomers and monomers of PA12, improves mechanical properties, improves coextrusion processability and interlayer adhesion of a multi-layered tube, and reduces manufacturing cost.

The composition for a fuel tube according to the present invention may include at least one of an antioxidant, an impact modifier, a plasticizer, a chain extender, a fluidity improver, a conductive agent, and a stabilizer in PA12. That is, the present fuel tube composition can be prepared by adding major additives such as impact modifiers and plasticizers to polymerized PA12, and adding a chain extender during compounding or tube molding.

Here, PA12 may have a weight average molecular weight (Mw) of 45,000 to 100,000.

The antioxidant is added to prevent oxidation of the composition for fuel tube, and contains a material selected from the group consisting of disubstituted phenols, phenyl phosphite, hydroperoxide decomposing agents, sterically hindered phenols, and combinations thereof. it could be More specifically, the antioxidant may be one using a known antioxidant, for example, Irganox 1098, Irganox 1093, Irgafos 168, etc. may be used. On the other hand, the antioxidant may be preferably used at the same time of two or more antioxidants of different types, the weight mixing ratio of each of the two or more antioxidants may be the same as each other.

In the case of the polyamide resin itself or the composition mixed with various additives, there is a problem in that the impact resistance is lowered against sudden impact or external stress, particularly at a low temperature of minus 40 degrees or less, and the impact modifier is added to improve this problem. As such, it is possible to improve low-temperature impact resistance by adding an impact modifier.

The impact modifier includes ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), ethylene-butene rubber (EBR), and ethylene-octene rubber (Ethylene). Octene Rubber, EOR), Butadiene Rubber (BR), High Density Polyethylene, Styrene-ethylene/butane Rubber, Acrylate Rubber, Maleic Anhydride are grafted (graft) may include at least one of a polymerized ethylene-propylene rubber, an ethylene-propylene-diene rubber, an ethylene-butene rubber, an ethylene-octene rubber, and a styrene-ethylene/butene rubber.

At this time, 3 to 15 parts by weight of the impact modifier may be included with respect to 100 parts by weight of PA12.

The plasticizer may include at least one of a sulfonamide series, a benzoate series, and a phthalate series.

Examples of sulfonamides include N-butylbenzenesulfonamide (N-BBSA), N-ethylbentenesulfonamide (N-EBSA), N-propylbenzenesulfonamide (N-PBSA), butyldodecylbenzenesulfonamide (BDBSA) , dimethylbenzenesulfonamide (DMBSA) may be used, and 2-ethylhexyl-4-hydroxybenzoate may be used as the benzoate series, and the phthalate series may be used. Dioxyl phthalate (Dioctyl phthalate) and the like may be used.

The plasticizer can contribute to achieving processing properties by being added to the resin, for example, by improving the fluidity of the high-viscosity resin in the extrusion processing step, thereby reducing the extrusion load and improving productivity, and imparting ductility to improve moldability during tube molding can be improved In this case, 3 to 15 parts by weight of the plasticizer may be included with respect to 100 parts by weight of PA12. By adding the plasticizer of this value, the strength and low-temperature impact resistance of the tube can be maintained while ensuring sufficient fluidity and moldability.

The chain extender is bislactam (Bis-lactam), bisoxazoline (Bis-oxazoline), bisoxazine (Bis-oxazine), bisoxazolinone (Bis-oxazolinone), bis-epoxide (Bis-epoxide) , Phosphide, Phosphite, Diisocyanate, Dicyanate, Dianhydride, Bis-ketenimine, Ethylene Maleic Anhydride Copolymer ( Ethylene maleic anhydride copolymer) and styrene maleic anhydride copolymer (Styrene maleic anhydride copolymer) may include at least one of the series, but is not limited thereto and may be selected without limitation as long as it can satisfy the required physical properties. . As such a chain extender, commercially available BRUGGOLEN® M-1251, M-1253, etc. may be used.

In this case, 0.1 to 5 parts by weight of the chain extender may be included with respect to 100 parts by weight of PA12. By adding the chain extender at this level, the elution by fuel is suppressed and mechanical properties are increased by extending the chains of unreacted oligomers or monomers remaining in the PA12 neat resin.

That is, the chain extender does not promote or induce crosslinking between the main chains of PA12, but increases the molecular weight (weight average molecular weight) through reaction with the terminal active group of PA12, and narrows the Polydispersity Index (PI) range. It becomes possible to increase chemical resistance and mechanical properties.

The composition for a fuel tube according to the present invention may further include a capping agent to suppress the addition reaction, if necessary.

The capping agent may include at least one of acetic anhydride, phthalic anhydride, hexamethyl disilazane, acetic acid, and cyclohexylamine.

In this case, 0.1 to 4 parts by weight of the capping agent may be included based on 100 parts by weight of PA12.

Examples of the fluidity improving agent include long-chain aliphatic carboxylic acids having 12 or more carbon atoms such as stearic acid and montanic acid and derivatives thereof (eg, esters, alkali metal salts, alkaline earth metal salts, amides, etc.), higher aliphatic alcohols having 12 or more carbon atoms, such as stearyl alcohol, and derivatives thereof , polyethylene wax, polypropylene wax, amide wax, polysiloxane, perfluorinated polyether, oxidized high-density polyethylene, fluorine-based resin, molybdenum disulfide, and may be at least one selected from dendrimers. BRUGGOLEN®'s TP-P1507, TP-P1508, Calcium Stearate, and Licowax E (Montanic acid ester wax) commercially available may be used as such a fluidity improving agent.

Meanwhile, preferably, the long-chain aliphatic carboxylic acid and its derivatives, and the higher aliphatic alcohol and its derivatives may have 12 or more carbon atoms and 40 or less carbon atoms.

When a fluidity improver is added, the fluidity of the resin is improved during processing, which contributes to reducing the extrusion load and increasing productivity. That is, by adding the fluidity improver, it is possible to reduce the dissolution of the plasticizer while maintaining fluidity instead of reducing the content of the plasticizer. effect can be expected. At this time, based on 100 parts by weight of PA12, 0.1 to 5 parts by weight of the fluidity improving agent may be included. When 5 parts by weight or more is exceeded, the mechanical properties of the composition may be deteriorated.

If necessary, in order to impart conductivity to the composition for fuel tube according to the present invention, a conductive agent may be added, and the conductive agent may include at least one of carbon nanotubes, carbon black, and carbon fibers.

At this time, based on 100 parts by weight of PA12, 0.1 to 10 parts by weight of the conductive agent may be included. When the conductive agent is added in an amount of less than 0.1 parts by weight, the conductivity is lowered to reduce effectiveness, and when it exceeds 10 parts by weight, fluidity and mechanical properties during processing may be reduced.

The composition for a fuel tube according to the present invention may further include a stabilizer if necessary. In this case, the stabilizer may be at least one selected from phosphite, sterically hindered phenol, secondary amine, UV absorber, HALS stabilizer, and metal salt. In this case, 0.002 to 1 part by weight of the stabilizer may be included with respect to 100 parts by weight of PA12.

A situation in which the composition and the tube are exposed to high temperatures by the addition of the stabilizer, for example, a compounding process for preparing a composition by mixing an additive, a molding process for extruding a tube using the prepared composition, and a high temperature for the manufactured tube during use When exposed to , the effect of maintaining physical properties can be expected by suppressing the degradation, bonding, and crosslinking of PA12 resin.

The composition for a fuel tube comprising at least one of the aforementioned antioxidants, impact modifiers, plasticizers, chain extenders, fluidity improvers, conductive agents, stabilizers, and capping agents has mechanical properties such as impact strength, tensile strength, and flexural strength compared to the same composition. It has the effect of improving physical properties.

As described above, a composite material for a fuel tube having a multi-layer structure may be constituted by including the composition for a fuel tube. As shown in FIG. 2 , the composite material for fuel tube may have an outer layer comprising PA12, an intermediate layer comprising EVOH, and an inner layer comprising an antioxidant, impact modifier, plasticizer, chain extender, fluidity improver, and conductive material. agent, and may include PA12 containing at least one of a capping agent. In this case, each layer may be adhered via a PA adhesive.

In addition, fuel tubes can be manufactured including this composite material for fuel tubes.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

실시예Example 1. One. 언료Unrequited 튜브용 조성물의 제조 Preparation of composition for tube

To prepare the composition for fuel tubes according to the invention, 90.8 wt% of UBE 3030U PA 12 as polyamide 12 resin, 0.5 wt% of Irganox 1098 as primary antioxidant, 0.5 wt% of Irgafos 168 as secondary antioxidant, as plasticizer A composition for a fuel tube was prepared by mixing 8 wt% of N-butylbenzenesulfonamide (N-BBSA) and 0.2 wt% of calcium stearate as a fluidity improver.

실시예Example 2. 2. 언료Unrequited 튜브용 조성물의 제조 Preparation of composition for tube

In Example 1, Mitsui TAFMER MH-5020C as an impact modifier and Bruggolen M-1251 as a chain extender were further mixed, and polyamide 12 resin, primary antioxidant, secondary antioxidant, impact modifier, chain extender, plasticizer and a composition for a fuel tube was prepared in the same manner except that the weight mixing ratio (wt%) of the fluidity improving agent was 82.8: 0.5: 0.5: 5: 3: 8: 0.2.

비교예comparative example . . 언료Unrequited 튜브용 조성물의 제조 Preparation of composition for tube

Except that in Example 1, no plasticizer was added and the weight mixing ratio (wt%) of the polyamide 12 resin, the primary antioxidant, the secondary antioxidant, and the fluidity improving agent was 98.8: 0.5: 0.5: 0.2 A composition for a fuel tube was prepared using the same method.

Hereinafter, in Table 1, the compositions of the compositions for fuel tubes prepared in Examples and Comparative Examples are shown.

[표 1][Table 1]

실험예Experimental example . . 언료Unrequited 튜브용 조성물의 물성측정 Measurement of physical properties of composition for tubes

In order to measure the physical properties of the composition for a fuel tube prepared in each of the Examples and Comparative Examples with respect to the test fuel, first, each of the compositions was injected to prepare a specimen. Thereafter, each prepared specimen was treated with FAM B test fuel (42.3 vol% toluene, 25.4 vol% isooctane, 4.3 vol% ethanol, 12.7 vol% diisobutylene, 15.0 vol% methanol and 0.5 vol% of deionized water) at a temperature of 60° C. for 72 hours.

Thereafter, the mass difference, impact strength, and flexural strength of each specimen were measured before and after immersion, and are shown in Table 2 below.

[표 2][Table 2]

As shown in Table 2 above, in the case of the composition for fuel tube prepared in Comparative Example, a single molecule (FAM B, plasticizer) penetrated into the space between the polyamide 12 resins and was plasticized and softened, resulting in an increase in mass and impact strength. and the flexural strength decreased. That is, it was confirmed that the test fuel had low barrier properties.

On the other hand, in the case of the composition for fuel tube prepared in Example 1, although the impact strength was increased, it was confirmed that the increase in mass and the decrease in flexural strength were remarkably low, and in the case of the composition for fuel tube prepared in Example 2, the mass And it was confirmed that the impact strength was decreased, and the decrease in the flexural strength was also very low.

Through this, it was confirmed that the composition for fuel tube prepared according to the embodiment of the present invention had high barrier properties against the test fuel, and in particular, in the case of Example 2 in which a chain extender was mixed, monomolecular penetration inhibition and softening were inhibited. It was confirmed that the mass was reduced (partial oligomer dissolution) and the retention rate of impact strength and flexural strength was very high.

On the other hand, the components eluted after immersion in the test fuel of the specimens prepared in Examples 1 and 2 and Comparative Examples, respectively, were analyzed, and GC/MS graphs showing the results are shown in FIGS. 3 to 5, respectively.

First, referring to FIG. 5 showing the results according to the comparative example, it was confirmed that the monomer peak was observed and the monomer was eluted.

On the other hand, referring to FIG. 3 showing the result according to Example 1 and FIG. 4 showing the result according to Example 2, it was confirmed that the monomer was not eluted because the monomer peak was not observed, and the plasticizer and dimer was confirmed to be eluted in a small amount. In particular, in the case of Example 2, compared to Example 1, it was confirmed that the amount of eluted plasticizer and dimer was small, indicating the best performance.

As mentioned above, although the present invention has been described in detail with preferred embodiments, the scope of the technical idea of the present invention is not limited to these embodiments. Accordingly, various modifications or equivalent ranges of embodiments may exist within the scope of the technical spirit of the present invention. Therefore, the scope of the technical idea according to the present invention should be interpreted by the claims, and the technical idea within the equivalent or equivalent scope should be interpreted as belonging to the scope of the present invention.

Claims

to polyamide 12 resin,

A composition for a fuel tube comprising an antioxidant, a plasticizer and a flow improver.
According to claim 1,

The weight average molecular weight of the polyamide 12 resin is 45,000 to 100,000 composition for a fuel tube.
According to claim 1,

wherein the antioxidant comprises a material selected from the group consisting of disubstituted phenols, phenyl phosphites, hydroperoxide degrading agents, sterically hindered phenols, and combinations thereof.
According to claim 1,

The plasticizer composition for a fuel tube comprising a material selected from the group consisting of sulfonamide series, benzoate series, phthalate series, and combinations thereof.
According to claim 1,

The fluidity improving agent is a long-chain aliphatic carboxylic acid having 12 or more carbon atoms, a derivative of a long-chain aliphatic carboxylic acid having 12 or more carbon atoms, a higher aliphatic alcohol having 12 or more carbon atoms, a derivative of a higher aliphatic alcohol having 12 or more carbon atoms, polypropylene wax, amide wax, polysiloxane, perfluorinated polyether, A composition for a fuel tube comprising a material selected from the group consisting of oxidized high-density polyethylene, fluorine-based resin, molybdenum disulfide, dendrimers, and combinations thereof.
According to claim 1,

Compared to 100 parts by weight of the polyamide 12 resin,

The content of the antioxidant is 1 part by weight to 5 parts by weight,

The content of the plasticizer is 3 parts by weight to 15 parts by weight,

The content of the fluidity improving agent is 0.1 parts by weight to 5 parts by weight of the composition for a fuel tube.
According to claim 1,

The composition for a fuel tube further comprises an impact modifier and a chain extender.
8. The method of claim 7,

The impact modifier is ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-octene rubber, butadiene rubber, high-density polyethylene, styrene-ethylene/butene rubber, acrylate rubber, maleic anhydride graft-polymerized A composition for a fuel tube comprising a material selected from the group consisting of ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-octene rubber, styrene-ethylene/butene rubber, and combinations thereof.
8. The method of claim 7,

The chain extender is bislactam, bisoxazoline, bisoxazine, bisoxazolinone, bisepoxide, phosphide, phosphite, diisocyanate, dicyanate, dianhydride, bisketenimine, ethylene male A composition for a fuel tube comprising a material selected from the group consisting of an acid anhydride copolymer, a styrene maleic anhydride copolymer series, and combinations thereof.
8. The method of claim 7,

Compared to 100 parts by weight of the polyamide 12 resin,

The content of the impact modifier is 3 parts by weight to 15 parts by weight,

The content of the chain extender is 0.1 parts by weight to 5 parts by weight of the composition for a fuel tube.
According to claim 1,

The composition for a fuel tube further comprises a material selected from the group consisting of a capping agent, a conductive agent, a stabilizer, and combinations thereof.
12. The method of claim 11,

The capping agent comprises a material selected from the group consisting of acetic anhydride, phthalic anhydride, hexamethyldisilazane, acetic acid, cyclohexylamine, and combinations thereof.
12. The method of claim 11,

The conductive agent is a fuel tube composition comprising a material selected from the group consisting of carbon nanotubes, carbon black, carbon fibers, and combinations thereof.
12. The method of claim 11,

wherein the stabilizer comprises a material selected from the group consisting of phosphites, sterically hindered phenols, secondary amines, UV absorbers, HALS stabilizers, metal salts, and combinations thereof.
12. The method of claim 11,

Based on 100 parts by weight of the polyamide 12 resin,

The content of the capping agent is 0.1 parts by weight to 4 parts by weight,

The content of the conductive agent is 0.1 parts by weight to 10 parts by weight,

The content of the stabilizer is 0.002 parts by weight to 1 part by weight of the composition for a fuel tube.
an outer layer comprising polyamide 12 resin;

an intermediate layer comprising ethylene vinyl alcohol; and

A multilayer composite material for a fuel tube comprising a; an inner layer comprising polyamide 12 resin.
17. The method of claim 16,

The inner layer is

A multilayer composite material for fuel tubes, comprising polyamide 12 resin containing antioxidants, plasticizers and flow improvers.
18. The method of claim 17,

The inner layer is

The multilayer composite material for fuel tube further comprising an impact modifier and a chain extender.
18. The method of claim 17,

The inner layer is

The multilayer composite material for a fuel tube further comprising a material selected from the group consisting of a capping agent, a conductive agent, a stabilizer, and combinations thereof.
A fuel tube comprising the multilayer composite material for a fuel tube according to claim 16 .