JP2013095800A - Polyamide resin composition for fuel piping component and fuel piping component obtained by molding the same - Google Patents

Abstract

[PROBLEMS] To achieve a sufficient relative viscosity ηr as compared with a conventional aliphatic polyamide resin, wide molding temperature range, heat resistance, melt moldability, and molding cycle can be reduced, and low water absorption is impaired. Polyamide resin composition for fuel piping parts containing polyamide resin with excellent chemical resistance, hydrolysis resistance and fuel barrier properties, and environmental resistance such as low temperature impact resistance and chemical resistance obtained by molding it And a fuel pipe component excellent in fuel impermeability.
A polyamide resin composition for a fuel pipe part comprising a polyamide resin (component A), wherein the component A is a combination of a unit derived from a dicarboxylic acid and a unit derived from a diamine. Oxalic acid (compound a) is included, and the diamine includes 1,6-hexanediamine (compound b) and 2-methyl-1,5-pentanediamine (compound c), and the molar ratio of the compound b to the compound c is A polyamide resin composition for fuel pipe parts having a ratio of 99: 1 to 50:50.
[Selection figure] None

Description

  The present invention relates to a polyamide resin composition for fuel pipe parts and a fuel pipe part obtained by molding the same.

Hereinafter, the name of the polyamide resin may be based on JIS6920-1.
Crystalline polyamides represented by nylon 6 (PA11), nylon 66 (PA12), etc. are widely used as textiles for clothing, industrial materials, or general-purpose engineering plastics because of their excellent properties and ease of melt molding. However, on the other hand, problems such as changes in physical properties due to water absorption, acid, high-temperature alcohol, deterioration in hot water, etc. have been pointed out, and there is an increasing demand for polyamides with better dimensional stability and chemical resistance. ing.

  A polyamide resin using oxalic acid as a dicarboxylic acid component is called a polyoxamide resin, and is known to have a higher melting point and lower water absorption than other polyamide resins having the same amino group concentration (Patent Document 1). It is expected to be used in fields where the use of conventional polyamides, where changes in physical properties have become a problem, is difficult.

So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. For example,
Non-Patent Document 1 discloses a polyoxamide resin using 1,6-hexanediamine as a diamine component,
Non-Patent Document 2 discloses a polyoxamide resin (hereinafter also referred to as PA92) in which the diamine component is 1,9-nonanediamine,
Patent Document 2 discloses a polyoxamide resin using various diamine components and dibutyl oxalate as a dicarboxylic acid ester,
Patent Document 3 discloses a polyoxamide resin using two kinds of diamines of 1,9-nonanediamine and 2-methyl-1,8-octanediamine as a diamine component in a specific ratio.

JP 2006-57033 A Japanese National Patent Publication No. 5-506466 WO2008 / 072754

S. W. Shalaby, J. et al. Polym. Sci. , 11, 1 (1973) L. Franco, et al. , Macromolecules, 31, 3912 (1998).

However,
Regarding the polyoxamide resin disclosed in Non-Patent Document 1, the melting point (about 320 ° C.) is close to the thermal decomposition temperature (1% weight loss temperature in nitrogen; about 310 ° C.), so that melt polymerization and melt molding are difficult. It is not something that can withstand practical use,
The polyoxamide resin disclosed in Non-Patent Document 2 discloses a production method and crystal structure when diethyl oxalate is used as the oxalic acid source, and PA92 obtained here has an intrinsic viscosity of 0.97 dL / g. , A polymer having a melting point of 246 ° C., and only a low molecular weight body that cannot be formed into a tough molded body has been obtained,
Regarding the polyoxamide resin disclosed in Patent Document 2, it is shown that PA92 having an intrinsic viscosity of 0.99 dL / g and a melting point of 248 ° C. is produced, but the low molecular weight is such that a tough molded body cannot be molded. There is a problem that only the body is obtained,
Regarding the polyoxamide resin disclosed in Patent Document 3, a polyoxamide resin using two kinds of diamines of 1,9-nonanediamine and 2-methyl-1,8-octanediamine as a diamine component in a specific ratio is shown. However, these polyoxamide resins have a wide moldable temperature range, excellent moldability, and low water absorption, chemical resistance, hydrolysis resistance, fuel barrier properties, etc., but the melting point is around 240 ° C., Heat resistance is slightly inferior for electrical and electronic equipment applications that require molding cycle properties and a high melting point.

Conventional plastic fuel pipe parts have large wall permeability of fuel such as gasoline and alcohol / gasoline blended fuel, air pollution due to diffusion of gasoline and alcohol / gasoline blended fuel into the air, and deterioration of automobile fuel consumption Therefore, higher fuel impermeability is required.
Also in fuel piping parts, conventional polyamide resins have been pointed out as problems such as changes in physical properties due to water absorption, deterioration in acid, hot alcohol, hot water, etc., and more chemical resistance and dimensional stability. There is also a demand for an excellent polyamide resin.

The problem to be solved by the present invention is:
Compared with conventional polyoxamide resin,
Melting point Tm (° C.) measured by differential scanning calorimetry measured at a rate of temperature increase of 10 ° C./min under a nitrogen atmosphere and measurement at a rate of temperature increase of 10 ° C./min under a nitrogen atmosphere Moldable temperature estimated from temperature difference (Td-Tm) (° C.) (hereinafter also referred to as temperature difference (Td-Tm)) from 1% weight loss temperature Td (° C.) (thermal decomposition temperature) in thermogravimetric analysis Wide,
Excellent heat resistance estimated from the melting point Tm,
It has a moderate melt viscosity and excellent melt moldability, and can reduce the molding cycle.
Polyamide resin that can form molded products with superior chemical resistance, hydrolysis resistance, and fuel barrier properties compared to conventional aliphatic polyamide resins without impairing the low water absorption found in aliphatic linear polyoxamide resins The present invention provides a polyamide resin composition for fuel pipe parts, and a fuel pipe part having excellent environmental resistance such as low temperature impact resistance, chemical resistance and fuel impermeability obtained by molding the same. .

The present invention
(1) A polyamide resin composition for fuel piping parts, comprising a polyamide resin (component A),
The component A is composed of a unit derived from a dicarboxylic acid and a unit derived from a diamine,
The dicarboxylic acid comprises oxalic acid (compound a);
The diamine comprises 1,6-hexanediamine (compound b) and 2-methyl-1,5-pentanediamine (compound c);
A polyamide resin composition for a fuel pipe part having a molar ratio of the compound b to the compound c of 99: 1 to 50:50, and (2) a polyamide resin composition for a fuel pipe part according to (1) above are molded. This is the fuel pipe part obtained.

According to the present invention,
Compared with conventional polyoxamide resin,
The moldable temperature range estimated from the temperature difference (Td−Tm) is wide.
Excellent heat resistance estimated from melting point Tm and melt formability estimated from temperature difference (Tm-Tc)
Polyamide resin that can form molded products with superior chemical resistance, hydrolysis resistance, and fuel barrier properties compared to conventional aliphatic polyamide resins without impairing the low water absorption found in aliphatic linear polyoxamide resins The present invention can provide a polyamide resin composition for fuel pipe parts, and a fuel pipe part excellent in environmental resistance such as low temperature impact resistance, chemical resistance, and fuel impermeability obtained by molding the same. .

Quick connector example

[Component A]
(1) Configuration of Component A Component A, which is a polyamide resin in the present invention,
The dicarboxylic acid component is succinic acid and the diamine component consists of 1,6-hexanediamine and 2-methyl-1,5-pentanediamine,
A polyamide resin formed by bonding a unit derived from a dicarboxylic acid and a unit derived from a diamine,
The dicarboxylic acid comprises oxalic acid (compound a);
The diamine comprises 1,6-hexanediamine (compound b) and 2-methyl-1,5-pentanediamine (compound c);
The molar ratio of the compound b to the compound c is 99: 1 to 50:50,
Preferably, the relative viscosity ηr measured at 25 ° C. using a solution of Component A having a concentration of 1.0 g / dl in 96% sulfuric acid is 1.8 to 6.0.

  Component A uses compounds a, b and c, preferably polycondensation using a mixture thereof, so that it has a high molecular weight, a high melting point, a large difference between the melting point and the thermal decomposition temperature, and excellent melt moldability. Furthermore, it is excellent in chemical resistance, hydrolysis resistance and fuel barrier properties as compared with conventional polyamides without impairing the low water absorption seen in linear polyoxamide resins.

From the viewpoint of ensuring chemical resistance, hydrolysis resistance and fuel barrier properties, component A has a molar ratio of compound b to compound c:
Preferably, it is less than 99: 1 to 55:45 mol%,
More preferably, it is 99: 1-60: 40 mol%.
Hereinafter, the molar ratio of the compound b and the compound c also means the molar ratio of the unit derived from the compound b and the unit derived from the compound c in the component A.

The amino terminal group concentration of component A is from the viewpoint of molding processability, mechanical properties, molding appearance, etc.
Preferably it is 1.5 × 10 ^{−5 to} 1.0 × 10 ⁻⁴ eq / g,
More preferably 1.3 × 10 ^{−5 to} 1.0 × 10 ⁻⁴ eq / g,
More preferably ^{7.0 × 10 -4 ~1.0 × 10 -4} eq / g.
The amino end group concentration of component A is
It can be increased by polymerizing with a small molecular weight,
It can be reduced by increasing the molecular weight.
The amino terminal group concentration of component A was determined by neutralization determination by dissolving component A in a phenol: methanol = 9: 1 mixed solution at 120 ° C., using 0.05 N HCl and thymol blue as an indicator.

When compound a (oxalic acid) is directly used as a raw material in the production of component A, compound a (succinic acid) itself is thermally decomposed, and the melting point of component A exceeds the thermal decomposition temperature. (Hereinafter, also referred to as oxalic acid source) and obtained by polycondensation of oxalic acid derived from the oxalic acid source and diamine. This oxalic acid is derived from an oxalic acid source such as oxalic acid diester, and any oxalic acid may be used as long as it has reactivity with an amino group.
As the oxalic acid source, oxalic acid diester is preferable from the viewpoint of suppressing side reactions in the polycondensation reaction. Dimethyl oxalate, diethyl oxalate, di-n- (or i-) propyl oxalate, di-n- (or i-, or t-) oxalate Examples thereof include oxalic acid diesters of aliphatic monohydric alcohols such as butyl, oxalic acid diesters of alicyclic alcohols such as dicyclohexyl oxalate, and oxalic acid diesters of aromatic alcohols such as diphenyl oxalate.
Among the oxalic acid diesters, oxalic acid diesters of aliphatic monohydric alcohols having more than 3 carbon atoms, oxalic acid diesters of alicyclic alcohols, and oxalic acid diesters of aromatic alcohols are more preferable,
Among them, dibutyl oxalate and diphenyl oxalate are more preferable,
More preferred is dibutyl oxalate.

(2) Relative viscosity of component A
Using oxalic acid as compound a as the carboxylic acid component,
As the diamine component, 1,6-hexanediamine as compound b and 2-methyl-1,5-pentanediamine as compound c are polycondensed so that the melting point is preferably in the range of 200 to 330 ° C. Compared to a polyamide resin obtained by polycondensation of compound a and compound b with a melting point exceeding 330 ° C. (hereinafter also referred to as comparative component A2), in the melt polymerization in the post-polymerization step of component A described later, Since it is not necessary to use an excessively high temperature condition in which a side reaction occurs and inhibits high molecular weight, high molecular weight (increasing relative viscosity) is possible.
Therefore, Component A has an excellent melt moldability because it can increase the relative viscosity as compared with the conventional polyamide resin.
In view of avoiding the tendency of the molded product after melt molding to become brittle and lowering the physical properties, to avoid the tendency to increase the melt viscosity at the time of melt molding and deteriorate the molding processability, the relative viscosity ηr and the melt viscosity are more than a certain level. From the viewpoint of being suitable for uses such as automobile parts and electrical / electronic parts that are preferably high and not excessively high, a 96% concentrated sulfuric acid solution having a concentration of component A of 1.0 g / dl is used. The relative viscosity ηr measured at 25 ° C. is
Preferably it is 1.8-6.0, Preferably it is 1.8-4.5, More preferably, it is 1.8-3.0, More preferably, it is 1.85-2.5, More preferably Can be 1.85 to 2.2.
In the melt polymerization in the post-polymerization step of component A described later, the relative viscosity ηr can be increased by increasing the degree of vacuum.

  From the same viewpoint, the melt viscosity of component A is preferably 100 to 700 Pa · s, more preferably 110 to 600 Pa · s, still more preferably 120 to 500 Pa · s, still more preferably 130 to 400 Pa · s, and further Preferably it is 150-300 Pa.s, More preferably, it is 160-220 Pa.s, More preferably, it is 170-200 Pa.s.

  Furthermore, from the same viewpoint, the number average molecular weight of Component A is preferably 10,000 to 50,000, more preferably 11,000 to 40,000, and still more preferably 11,000 to 35,000.

The number average molecular weight (Mn) is based on the signal intensity obtained from the 1H-NMR spectrum, for example, dibutyl oxalate as the oxalic acid source, 1,6-hexanediamine (compound b) and 2-methyl-1, as the diamine component. In the case of a polyamide produced using 5-pentanediamine (compound c) at a molar ratio of 90:10 [hereinafter abbreviated as PX6-2 (compound b / compound c = 90/10)], it is calculated according to the following formula. did.
Mn = np × 170.21 + n (NH ₂ ) × 115.20 + n (OBu) × 129.13 + n (NHCHO) × 29.14
In addition, the measurement conditions of 1H-NMR are as follows.
・ Model used: Bruker Biospin AVANCE500
-Solvent: Bisulfuric acid-Integration frequency: 1024 times Each term in the above formula is defined as follows.
Np = Np / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
N (NH ₂ ) = N (NH ₂ ) / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
N (NHCHO) = N (NHCHO) / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
N (OBu) = N (OBu) / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
Np = Sp / sp-N (NHCHO)
N (NH ₂ ) = S (NH ₂ ) / s (NH ₂ )
N (NHCHO) = S (NHCHO) / s (NHCHO)
N (OBu) = S (OBu) / s (OBu)
However, each term has the following meaning.
Np: Total number of repeating units in the molecular chain excluding terminal units of PA62 (compound B / compound C = 90/10).
Np: the number of repeating units in the molecular chain per molecule.
Sp: PX6-2 (compound b / compound c = 90/10) excluding the signal based on the proton of the methylene group adjacent to the oxamide group in the repeating unit in the molecular chain (around 3.1 ppm) Integration value.
Sp: The number of hydrogens (4) counted in the integral value Sp.
· _N (NH 2): The total number of terminal amino groups of PX6-2 (Compound b / Compound c = 90/10).
N (NH ₂ ): number of terminal amino groups per molecule.
S (NH ₂ ): Integral value of a signal (around 2.6 ppm) based on the proton of the methylene group adjacent to the terminal amino group of PX6-2 (compound b / compound c = 90/10).
S (NH ₂ ): The number of hydrogens (2) counted in the integrated value S (NH ₂ ).
N (NHCHO): total number of terminal formamide groups of PX6-2 (compound b / compound c = 90/10).
N (NHCHO): number of terminal formamide groups per molecule.
-S (NHCHO): The integral value of the signal (7.8 ppm) based on the proton of the formamide group of PX6-2 (compound b / compound c = 90/10).
S (NHCHO): The number of hydrogens (one) counted in the integral value S (NHCHO).
N (OBu): the total number of terminal butoxy groups of PX6-2 (compound b / compound c = 90/10).
N (OBu): number of terminal butoxy groups per molecule.
S (OBu): integrated value of a signal (around 4.1 ppm) based on the proton of the methylene group adjacent to the oxygen atom of the terminal butoxy group of PX6-2 (compound b / compound c = 90/10).
S (OBu): The number of hydrogens (two) counted in the integral value S (OBu).

(3) Physical properties of component A Component A further changes the polycondensation ratio of compounds b and c,
The temperature difference (Td−Tm) is large compared to the comparative component A2, and small compared to the polyamide resin obtained by polycondensation of the compound a and the compound c (hereinafter also referred to as the comparative component A1).
The melting point Tm is low compared to the comparative component A2, high compared to the comparative component A1,
1% weight loss temperature Td is higher than the comparative component A1,
The saturated water absorption rate can be smaller than the comparative component A2 and larger than the comparative component A1.

That is, the component A is compared with the conventional polyoxamide resin,
Relative viscosity ηr (high molecular weight),
Moldable temperature range estimated from the temperature difference (Td−Tm),
Heat resistance estimated from melting point Tm,
Both melt moldability estimated from melt viscosity and low water absorption can be sufficiently secured.

Component A has sufficient chemical resistance, resistance to resistance due to the high polymerization ratio (molar ratio) of compound b after sufficiently ensuring the moldable temperature range, heat resistance, melt moldability and low water absorption. Particularly contributes to hydrolyzability and fuel barrier properties.
Component A is also excellent in calcium chloride resistance from the viewpoint of requiring resistance to calcium chloride used as a snow melting agent in automotive applications.

From the viewpoint of sufficiently ensuring all of the moldable temperature range, heat resistance, melt moldability and low water absorption,
Tm is preferably 260 to 330 ° C, more preferably 265 to 330 ° C,
Td is preferably 341 to 370 ° C, more preferably 345 to 370 ° C, still more preferably 350 to 365 ° C,
Tc is preferably 231 to 305 ° C, more preferably 231 to 303 ° C.
The temperature difference (Td−Tm) is preferably 10 to 95 ° C., more preferably 20 to 95 ° C., still more preferably 25 to 95 ° C.,
The saturated water absorption is preferably 0 to 2.4, more preferably 1 to 2.4, still more preferably 2 to 2.4, and still more preferably 2.3 to 2.4.

(4) Production of Component A Component A can be produced using any method known as a method for producing polyamide, but from the viewpoint of high molecular weight and productivity,
Preferably, it is obtained by polycondensation reaction of diamine and oxalic acid diester batchwise or continuously.
More preferably, the diamine and the oxalic acid diester are obtained by a two-stage polymerization method comprising a pre-polycondensation step and a post-polycondensation step, or a pressure polymerization method described in WO2008-072754.
More preferable two-stage polymerization method and pressure polymerization method are specifically shown by the following operations.

(4-1) Two-stage polymerization method (i) Pre-polycondensation step: First, the inside of the reactor is purged with nitrogen, and then diamine (compounds b and c) and oxalic acid diester which is the oxalic acid source of compound a are mixed. When mixing, a solvent in which both the diamine and the oxalic acid diester are soluble may be used. As a solvent in which both the diamine component and the oxalic acid source component are soluble, toluene, xylene, trichlorobenzene, phenol, trifluoroethanol, and the like can be used, and toluene is particularly preferably used. For example, after heating the toluene solution which melt | dissolved diamine to 50 degreeC, oxalic acid diester is added with respect to this.
At this time, the charging ratio between the oxalic acid diester and the diamine is 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), from the viewpoint of increasing the molecular weight. Ratio), more preferably 0.99 to 1.01 (molar ratio).

  The temperature in the reactor charged in this way is increased under normal pressure while stirring and / or nitrogen bubbling. The reaction temperature is preferably controlled so that the final temperature reaches 80 to 150 ° C., preferably 100 to 140 ° C. The reaction time at the final temperature reached is 3-6 hours.

(Ii) Post-polycondensation step: In order to further increase the molecular weight, the polymer produced in the pre-polycondensation step is gradually heated in the reactor under normal pressure. From the final ultimate temperature of the pre-polycondensation step in the temperature rising process, that is, preferably from 80 to 150 ° C., finally,
The temperature is preferably 295 ° C. or higher and 350 ° C. or lower, more preferably 298 ° C. or higher and 345 ° C. or lower, more preferably 298 ° C. or higher and 340 ° C. or lower.
It is preferable to carry out the reaction while keeping the temperature rising time preferably 1 to 8 hours, more preferably 2 to 6 hours. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. A preferable final pressure in the case of carrying out the vacuum polymerization is 13.3 Pa to 0.1 MPa.

(4-2) Pressurized polymerization method First, diamine is placed in a pressure vessel and purged with nitrogen, and then heated to the reaction temperature under a sealing pressure. Thereafter, the oxalic acid compound is injected into the pressure vessel while maintaining the sealed pressure state at the reaction temperature, and the polycondensation reaction is started. The reaction temperature is not particularly limited as long as the polyamide produced by the reaction of the diamine and the oxalic acid compound can maintain a slurry or solution state and does not thermally decompose. For example, in the case of Component a, the reaction temperature is preferably 150 ° C to 250 ° C. Here, the charging ratio of dibutyl oxalate and diamine is 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), in terms of the molar amount of dibutyl oxalate / total molar amount of diamine. More preferably, it is 0.99 to 1.01 (molar ratio).
Next, while maintaining the inside of the pressure vessel in a sealed pressure state, the temperature is raised to a temperature not lower than the melting point of the polyamide resin and not pyrolyzed. For example, in the case of Component a, since the melting point is 245 to 300 ° C., the temperature is raised to 250 to 350 ° C., preferably 255 to 340 ° C., more preferably 260 to 335 ° C. The pressure in the pressure resistant container until reaching the predetermined temperature is adjusted to approximately 0.1 MPa, preferably 1 MPa to 0.2 MPa from the saturated vapor pressure of the alcohol to be generated. After reaching the predetermined temperature, the pressure is released while distilling off the produced alcohol, and the polycondensation reaction is continued under normal pressure nitrogen flow or reduced pressure as necessary. A preferable final pressure in the case of carrying out the vacuum polymerization is 13.3 Pa to 0.1 MPa.

(5) Component which can be used as dicarboxylic acid in component A In component A, other dicarboxylic acid components other than compound a can be used within a range not impairing the effects of the present invention.
As other dicarboxylic acid components other than compound a (oxalic acid),
Malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid , Aliphatic dicarboxylic acids such as suberic acid,
In addition, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid,
Further, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydi Aromatic dicarboxylic acids such as acetic acid, dibenzoic acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, 4,4′-biphenyldicarboxylic acid These may be added alone, or any mixture thereof may be added during the polycondensation reaction.
Furthermore, polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid can be used as long as melt molding is possible.
When other dicarboxylic acid components are used, the proportion thereof is 25 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, and more preferably 5 mol% or less with respect to compound a (succinic acid). More preferably, it is more preferably 0 mol% (that is, the dicarboxylic acid component consists only of compound a). The molar ratio of the other dicarboxylic acid component to the compound a (succinic acid) also means the molar ratio of the unit derived from the compound a and the unit derived from the other dicarboxylic acid component in the component A.

In component A, other diamine components other than compounds b and c can be used within the range not impairing the effects of the present invention.
As other diamine components other than 1,6-hexanediamine and 2-methyl-1,5-pentanediamine, ethylenediamine, propylenediamine, 1,4-butanediamine, 1,9-nonanediamine, 2-methyl-1, 8-octanediamine, 1,8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4- Aliphatic diamines such as trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, and 5-methyl-1,9-nonanediamine;
Furthermore, alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine,
Furthermore, aromatic diamines such as p-phenylenediamine, m-phenylenediamine, p-xylenediamine, m-xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylether ,
These may be added alone, or any mixture thereof may be added during the polycondensation reaction.
When other diamine components are used, the proportion thereof is 25 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less, with respect to compounds b and c. More preferably, it is 0 mol% (that is, the diamine component consists only of compounds b and c). In addition, the molar ratio of the other diamine component with respect to the compounds b and c also means the molar ratio of the units derived from the compounds b and c and the units derived from the other diamine components in the component A.

(6) Molding of component A As the molding method of component A, all known molding methods applicable to polyamide such as injection, extrusion, hollow, press, roll, foaming, vacuum / pressure air, and stretching can be used. From the viewpoint of shortening the molding cycle performance, it is particularly suitable for molding with fuel piping parts, and can be processed into films, sheets, molded articles, fibers, etc. by these molding methods.

[Polyamide resin composition for fuel piping parts]
(Content of component A)
The polyamide resin composition for fuel pipe parts of the present invention (hereinafter also referred to as a resin composition) has a good moldable temperature range, heat resistance, melt moldability (hereinafter referred to as thermal characteristics) for improving productivity during molding. From the viewpoint of ensuring environmental resistance such as low-temperature impact resistance, chemical resistance, and liquid, vapor and / or gas impermeability, etc.
The content of Component A in the resin composition is preferably 50 to 100% by mass, more preferably 55 to 100% by mass, and still more preferably 60 to 100% by mass.

(Other ingredients)
In the fuel piping component application, it is preferable to include the following as other components.

(1) Polymer other than Component A In the resin composition of the present invention, if necessary, in order to utilize the characteristics of each polymer,
Other polyamides other than component A, such as at least one polyamide selected from the group consisting of polyoxamides, aromatic polyamides, aliphatic polyamides and alicyclic polyamides, and / or polymers other than polyamides, such as thermoplastic polymers An elastomer can be included.

  The polymer other than component A is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 0 to 50 parts by mass, more preferably 0 to 40 parts by mass, and still more preferably, relative to 100 parts by mass of component A. Is 0-30 parts by mass.

(2) Additive The resin composition of the present invention can contain an additive as long as the effects of the present invention are not impaired. Examples of additives include pigments, dyes, colorants, heat resistance agents, antioxidants, weathering agents, UV absorbers, light stabilizers, lubricants, crystal nucleating agents, crystallization accelerators, mold release agents, and antistatic agents. , Stabilizers such as plasticizers and copper compounds, antistatic agents, flame retardants, glass fibers, lubricants, fillers, reinforcing fibers, reinforcing particles, foaming agents and the like.

The method for adding the polymer and / or additive other than the above component A is not particularly limited as long as each method can be dispersed in component A, and the component can be added at any time that does not impair the effect. A can be added.
For example, polymers and / or additives other than component A
It can also be added during or after the polycondensation reaction of component A.

(3) Layered silicate The resin composition of the present invention comprises only component A, and produces a fuel piping component excellent in environmental resistance such as low-temperature impact resistance, chemical resistance and liquid, vapor and / or gas impermeability. However, in applications where dimensional stability with higher accuracy is required, the resin composition of the present invention can further contain a layered silicate.
Moreover, by adding layered silicate, the rigidity of fuel pipe parts prepared from the resin composition of the present invention, environmental resistance such as low temperature impact resistance, chemical resistance and impermeability of liquid, vapor and / or gas Can be improved.

  The layered silicate is preferably a flat plate having a side length of 0.002 to 1 μm and a thickness of 6 to 20 mm. In addition, the layered silicate is preferably one in which each layer in the component A is uniformly dispersed with an interlayer distance of about 20 mm or more.

  Here, “interlayer distance” refers to the distance between the centroids of the plate-like layered silicate, and “uniformly dispersed” means that each layer exists mainly in a random state, and the layered silicate 50% by mass or more, preferably 70% by mass or more, is dispersed in a single layer without forming a multilayer.

The amount of the layered silicate is not particularly limited as long as the effect of the layered silicate is exerted, but the rigidity, weather resistance and / or heat resistance of the fuel pipe parts, and liquid or vapor From the viewpoint of improving the barrier properties against and from the viewpoint of securing the molding processability and impact resistance of the resin composition,
Preferably 0.05 to 10 parts by mass,
More preferably 0.05-8 parts by mass,
More preferably, it is 0.05-5 mass parts.

  As a raw material of the said layered silicate, the layered phyllosilicate mineral comprised from the layer of magnesium silicate or an aluminum silicate, ie, the aluminum silicate phyllosilicate, or the magnesium silicate phyllosilicate can be illustrated. Specific examples include smectite clay minerals such as montmorillonite, saponite, beidellite, nontronite, hectorite, and stevensite, vermiculite, halloysite, and the like. It may be what was done.

  In order to disperse the layered silicate in component A, a swelling agent is usually used. The swelling agent has a role of expanding the interlayer of the clay mineral and a role of giving the clay mineral a force for taking up the interlayer polymer. In the present invention, it is preferable to use 1,6-hexanediamine and 2-methyl-1,5-pentanediamine as the swelling agent.

  The layered silicate is preferably pulverized using a mixer, a ball mill, a vibration mill, a pin mill, a jet mill, a beating machine, or the like to have a desired shape and size in advance.

  The method for adding the layered silicate is not particularly limited as long as the layered silicate can be uniformly dispersed in the component A. For example, when the raw material of the layered silicate is a multilayered clay mineral, as disclosed in JP-A-62-74957, the layered silicate is ionized with hydrochloric acid or the like, and a swelling agent such as, for example, 1,6-hexanediamine and 2-methyl-1,5-pentanediamine are added to widen the space between the layers of the layered silicate in advance. Subsequently, the raw material of component A can be introduce | transduced between the said layers, and also the said raw material can be polymerized between the said layers.

  Alternatively, using an organic compound as a swelling agent, the layers may be preliminarily spread to about 100 mm or more and melt-mixed with component A to disperse each layer in a polyamide resin.

(4) Plasticizer It is preferable to mix | blend a plasticizer with the polyamide resin composition of this invention from the viewpoint of the impact resistance in low temperature, and a softness | flexibility provision.
As a plasticizer, from the same viewpoint,
Preferred is an ester of benzenesulfonic acid butyramide and / or p-hydroxybenzoic acid and a linear or branched alcohol having 6 to 21 carbon atoms (for example, 2-ethylhexyl, p-hydroxybenzoate),
More preferred is benzenesulfonic acid butyramide.

From the viewpoint of securing a stable breaking pressure of the fuel pipe component and suppressing bleed out, the blending amount of the plasticizer is based on 100 parts by mass of the resin component in the polyamide resin composition of the present invention.
Preferably it is 1-30 mass parts, More preferably, it is 5-20 mass parts, More preferably, it is 10-15 mass parts.

(5) Conductive filler

The polyamide resin composition of the present invention can dissipate static electricity generated when transporting fluids such as fuel by forming fuel transportation parts in the fuel piping parts, and can prevent parts from being damaged or exploding due to sparks. From the viewpoint of becoming, it is preferable to blend a conductive filler.
For example, it is preferable that the fuel piping component is joined to a conductive joint and a conductive tube to form an electric transportation circuit.

  With conductivity, for example, when a flammable fluid such as gasoline is continuously in contact with an insulator such as resin, static electricity accumulates and sparks may occur, which may ignite the fuel. Electrical characteristics that do not accumulate static electricity. As a result, it is possible to prevent the occurrence of a spark due to static electricity generated when a fluid such as fuel is conveyed.

  The conductive filler referred to in the present invention includes all fillers added to impart conductive performance to the resin, and examples thereof include granular, flaky and fibrous fillers.

As the particulate filler, carbon black, graphite or the like can be preferably used. As the flaky filler, aluminum flakes, nickel flakes, nickel-coated mica and the like can be suitably used.
As the fibrous filler, metal fibers such as carbon nanotubes, carbon nanofibers, carbon fibers, carbon-coated ceramic fibers, carbon whiskers, aluminum fibers, copper fibers, brass fibers, and stainless fibers can be suitably used.
The fibrous filler is also preferable from the viewpoint of improving the mechanical properties of fuel piping parts obtained by molding the polyamide resin composition of the present invention.
Among these, carbon fiber and carbon black can be preferably used.

The carbon black includes all carbon blacks generally used for imparting conductivity.
Preferred carbon blacks include acetylene black obtained by complete combustion of acetylene gas, ketjen black produced by furnace-type incomplete combustion using crude oil as raw material, oil black, naphthalene black, thermal black, lamp black, channel black. , Roll black, disk black and the like, but are not limited thereto.

Carbon black is produced in various carbon powders having different characteristics such as average particle diameter, specific surface area, DBP oil absorption, and ash content.
There is no particular limitation on the characteristics of the carbon black, but those having a good chain structure and a high aggregation density are preferred.
From the viewpoint of obtaining excellent electrical conductivity with a smaller amount, while ensuring the impact resistance stably, the size of the carbon black,
Average particle size is
Preferably it is 500 nm or less,
More preferably 5-100 nm,
More preferably, it is 10-70 nm,
Specific surface area (BET method)
It is preferably 10 to 1500 m ² / g or more,
More preferably, it is 300-1500 m < ² > / g or more,
More preferably, it is 500-1500 m < ² > / g,
DBP (dibutyl phthalate) oil absorption is
It is preferably 50 to 500 ml / 100 g or more,
More preferably, it is 100-500ml / 100g,
More preferably, it is 300 to 500 ml / 100 g or more.
As the average particle size, 100 arbitrary particles were selected by electron microscopy, and the arithmetic average value of these particle sizes was used.
The DBP oil absorption is measured by the method defined in ASTM-D2414.

These conductive fillers may be surface-treated with a surface treatment agent such as titanate, aluminum, or silane.
It is also possible to use a granulated product to improve melt kneading workability.

Since the blending amount of the conductive filler varies depending on the type of conductive filler used, it cannot be specified unconditionally, but from the viewpoint of balance between conductivity, fluidity, mechanical strength, etc.
2 to 30 parts by weight is preferably selected with respect to 100 parts by mass of the entire resin including the polyamide resin.

Moreover, such a conductive filler is meant to obtain sufficient antistatic performance,
The amount of the fuel pipe component obtained by melt-extruding the polyamide resin composition blended with it is preferably 109 Ωcm or less, more preferably 106 Ωcm or less.

Since the blending amount of the conductive filler varies depending on the type of conductive filler used, it cannot be specified unconditionally, but from the viewpoint of balance between conductivity, fluidity, mechanical strength, etc.
2 to 30 parts by weight is preferably selected with respect to 100 parts by mass of the entire resin including the polyamide resin.

(6) Organic fiber and inorganic filler The polyamide resin composition of the present invention is preferably for fuel piping from the viewpoint of improving the mechanical properties of fuel piping parts obtained by molding the polyamide resin composition of the present invention. In joint applications, it is preferable to blend organic fibers and / or inorganic fillers (excluding conductive fillers).

  Examples of organic fibers include aramid fibers.

As an inorganic filler, inorganic fibers such as glass fiber and carbon fiber, wollastonite and potassium titanate whisker,
Inorganic fillers such as montmorillonite, talc, mica, calcium carbonate, silica, clay, kaolin, glass powder, and glass beads are used.

As inorganic fiber,
The fiber diameter is preferably 0.01 to 50 μm, more preferably 0.03 to 30 μm, still more preferably 0.05 to 20 μm,
The fiber length is preferably 0.1 to 15 mm, more preferably 0.5 to 15 mm, still more preferably 0.5 to 10 mm,
Are preferably used.
However, when the polyamide resin composition of the present invention is melt-kneaded to form a fuel pipe part, the inorganic fibers are cut and the like, and within the polyamide resin composition of the present invention or the fuel pipe part,
The fiber diameter of the inorganic fiber is 0.01-50 μm, preferably 0.03-30 μm,
The fiber length of the inorganic fibers may be about 0.5 to 10 mm, preferably about 0.7 to 5 mm.

Among inorganic fibers, glass fibers are preferably used because of their high reinforcing effect.
By strengthening the glass, the creep resistance of the fastening portion of the fuel pipe component of the present invention is high, and no deformation occurs, and a permanent seal is possible.

  In the polyamide resin composition for a fuel pipe part of the present invention for molding a fuel pipe part of the present invention, preferably a fuel pipe joint, the amount of organic fiber and / or inorganic filler used is the fuel pipe part of the present invention. From the viewpoint of stably securing the moldability, surface condition and mechanical strength of the polyamide resin composition for fuel pipe parts of the present invention, preferably 5 to 65% by weight, more preferably 10 to 60% by weight, Preferably it is 10 to 50% by weight.

[Fuel piping parts]
The fuel piping component of the present invention can be applied to various applications that require barrier properties of liquid or vapor fuel obtained by molding the polyamide resin composition for fuel piping components of the present invention.
Applicable uses include, for example, fuel tanks such as gasoline tanks, alcohol tanks, fuel tubes, brake oil tanks, clutch oil tanks, power steering oil tanks,
Fuel strainer, fluorocarbon tube for cooler, fluorocarbon tank, canister, air cleaner, intake system parts, tire inner liner, tank valve, fuel delivery pipe, quick connector, EGR parts, parts for fuel tanks such as oil strainer, fuel tube, Fuel pipe fittings are preferred,
Fuel tank parts, fuel tubes, and fuel pipe joints are more preferred.

(1) Fuel tank parts The fuel tank parts of the present invention are applied to the polyamide resin composition for fuel pipe parts of the present invention, such as injection, extrusion, hollow, press, roll, foaming, vacuum / pressure air, stretching, etc. Molding using a conventionally known molding method according to the method, vibration welding method, die slide injection, die welding injection method such as die rotary injection and two-color molding, ultrasonic welding method, spin welding method, hot plate welding method, hot wire welding method It can be applied to an object using a construction method, a laser welding method, a high frequency induction heating welding method, or the like. In forming the fuel tank component, the temperature of the polyamide resin is preferably maintained at a temperature that does not alter the polyamide resin.

(2) Fuel tube The fuel pipe part of the present invention is obtained by molding the polyamide resin of the present invention, and preferably a layer comprising the polyamide resin composition for fuel pipe parts of the present invention (hereinafter also referred to as layer 1). ).

The fuel pipe component of the present invention may be a single-layer tube composed of only layer 1, but is preferably used as a multilayer tube in which one or more layers other than layer 1 and layer 1 are laminated.
In practical fuel piping parts, many multilayer tubes are used.

  When the fuel piping component of the present invention is a multilayer tube, the thickness of the layer 1 is determined from the viewpoint of stably ensuring the fuel impermeability and simultaneously satisfying many required characteristics required for the fuel piping component. 20 to 80% of the wall thickness is preferable, and 30 to 70% is more preferable.

The outer diameter of the fuel piping component can be designed in consideration of the flow rate of various fuels, and the wall thickness is a thickness that does not increase the permeability of various fuels and can maintain the breaking pressure of the fuel tube, and Although it can be designed with a thinness that can maintain flexibility with a good degree of ease of assembly work of the fuel tube and vibration resistance during use,
The outer diameter is preferably 4 to 15 mm, more preferably 3 to 13 mm,
The wall thickness is preferably 0.5 to 2 mm, more preferably 0.7 to 1.8 mm.

As layers other than the layer 1 of the fuel piping component of the present invention, from the viewpoint of moldability and barrier properties,
Preferably, at least one resin selected from the group consisting of fluororesin, high-density polyethylene resin, PA11 resin and PA12,
More preferably, it consists of a resin composition containing at least one resin selected from the group consisting of PA11 resin and PA12 and a plasticizer (preferably, the above-mentioned suitable plasticizer).
The content of the plasticizer ensures a stable breaking pressure of the fuel pipe component and suppresses bleed out, with respect to 100 parts by mass of the resin component of the layer other than the layer 1.
Preferably it is 1-30 mass parts, More preferably, it is 5-20 mass parts, More preferably, it is 10-15 mass parts.

  In at least one layer constituting the fuel pipe component of the present invention, from the viewpoint of improving conductivity, a conductive filler (preferably, the above-mentioned suitable conductive filler) is blended in the above-mentioned suitable blending amount. It is preferable.

  Examples of the fluororesin include polytetrafluoroethylene (PTEF), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). Further, it may be a resin partially containing chlorine, such as polychlorofluoroethylene (PCTFE), or a copolymer with ethylene or the like.

  As the high density polyethylene resin, those having an average molecular weight of about 200,000 to 300,000 are preferable in consideration of mechanical properties. The high-density polyethylene resin has a low-temperature embrittlement temperature of −80 ° C. or less and excellent low-temperature impact resistance.

  Moreover, you may provide layers other than the layer 1 through an adhesive layer, when adhesiveness with the said composition layer is bad.

  Extrusion molding is preferably used as a method for producing the fuel pipe component of the present invention, and as a method for producing a multilayer fuel pipe component, for example, from the number of extruders corresponding to the number of constituent layers or the number of materials. A method in which the extruded molten resin is introduced into one multi-layer tube die, each layer is bonded in the die or immediately after the die is removed, and then manufactured in the same manner as normal tube molding. After molding, a method of coating another layer on the outside or inside of the tube can be exemplified.

As a method of manufacturing a multilayer tube such as a multilayer fuel tube, for example,
The molten resin extruded from a number of extruders corresponding to the number of constituent layers or the number of materials is introduced into one multilayer tube die,
Bond each layer in the die or immediately after exiting the die,
After that, the method of manufacturing in the same way as normal tube molding,
Once the single layer tube is formed,
Examples include a method of coating another layer on the outside of the tube.
The shape of the tube may be a straight tube or may be processed into a bellows shape.
For straight multilayer tubes, a protective layer may be provided on the outside,
Examples of the forming material include rubbers such as chloroprene rubber, ethylene propylene diene terpolymer, epichlorohydrin rubber, chlorinated polyethylene, acrylic rubber, chlorosulfonated polyethylene, and silicon rubber.

For example, using a molding machine of Plabor (Plastics Engineering Laboratory Co., Ltd.)
The resin composition of the present invention is melted separately at an extrusion temperature of 340 ° C., the discharged molten resin is molded into a laminated tubular body, cooled by a sizing die that controls dimensions, and taken up.
A single-layer tube formed by molding the resin composition of the present invention can be produced.

For example, using a molding machine of Plabor (Plastics Engineering Laboratory Co., Ltd.)
Extrusion temperature of the resin composition of the present invention is 340 ° C,
PA11 is melted separately at an extrusion temperature of 260 ° C., and the discharged molten resin is joined by an adapter, formed into a laminated tubular body, cooled by a sizing die that controls dimensions, and taken up.
Layer 1 (inner layer) formed by molding the resin composition of the present invention,
A two-layer hose can be manufactured as layer 2 (outer layer) formed by molding PA6.

For example, in a molding machine of Plabor (Plastics Engineering Laboratory Co., Ltd.)
Extrusion temperature of the resin composition of the present invention is 340 ° C,
PA11 was extruded at 260 ° C,
PA12 is melted separately at an extrusion temperature of 260 ° C., the discharged molten resin is joined by an adapter, formed into a laminated tubular body, cooled by a sizing die that controls dimensions, and taken up.
Layer 1 (innermost layer) formed by molding the resin composition of the present invention,
Layer 2 (intermediate layer) formed by molding PA6,
A three-layer tube having a layer 3 (outermost layer) formed by molding PA12 can be produced.

For example, as an apparatus for forming a multilayer tube, an innermost layer extruder, an inner layer extruder, an intermediate layer extruder and an outer layer extruder are provided, and the resin discharged from these four extruders is collected by an adapter into a tube shape. It is possible to use an apparatus comprising a die to be formed, a sizing die that cools the tube and controls its dimensions, and a take-up machine.
In this case, for example,
A resin composition containing PA11 of the present invention in the hopper of the innermost layer (layer 4) extruder,
A resin composition containing PA12 in the hopper of the inner layer (layer 3) extruder,
The resin composition of the present invention is applied to the hopper of the intermediate layer (layer 1) extruder.
A multilayer tube can be produced by introducing another resin composition into the hopper of the outer layer extruder.

For example, as a method for producing a high-temperature chemical solution and / or a laminated hose for gas transportation,
A method of melt extrusion using an extruder corresponding to the number of layers or the number of materials, and a method of simultaneously laminating inside or outside the die (coextrusion method),
Alternatively, once a single layer hose or a laminated hose for high temperature chemicals and / or gas transport manufactured by the above method is manufactured in advance, an adhesive is used on the outside sequentially, if necessary, A method of laminating and laminating (coating method) is mentioned.

  As the fuel piping component, a fuel piping component such as a tube for an automobile fuel piping system is preferably exemplified.

(3) Fuel Piping Joint The fuel pipe joint of the present invention may be produced by any method known as an injection molding method or other methods for producing resin joints of the polyamide resin composition for fuel pipe parts of the present invention. .

As a specific example of the joint for fuel piping of the present invention,
Preferably, a fuel pipe quick connector,
More preferably, the quick connector for fuel pipes obtained by molding the polyamide resin composition for fuel pipe parts of the present invention in the cylindrical main body portion of the quick connector for fuel pipes may be mentioned.

FIG. 1 shows a cross section of a typical quick connector 1.
In the quick connector 1 shown in this figure, the end of the steel tube 2 and the end of the plastic tube 3 are connected to each other. The flange-shaped portion 4 located away from the end of the steel tube 2 is detachably engaged by the retainer 5 of the connector 1, and the fuel is sealed by the row of O-rings 6. Further, at the joint portion between the plastic tube 3 and the connector 1, the connector end portion forms an elongated nipple 7 having a plurality of jaw portions 8 protruding in the radial direction.
The end portion of the plastic tube 3 is tightly fitted to the outer surface of the nipple 7 and the fuel is sealed by mechanical joining with the jaw portion 8 and an O-ring 9 provided between the tube and the nipple.

  As a manufacturing method of the quick connector, there is a method in which each part such as a cylindrical main body, a retainer and an O-ring is formed by injection molding and then assembled and assembled at a predetermined place.

The quick connector is assembled into an assembly that is engaged with a tube, preferably a tube formed from a resin composition containing a resin (hereinafter also referred to as a resin tube), and used as a fuel piping component.

  The quick connector and the resin tube may be mechanically joined by fitting, but are preferably joined by a welding method such as spin welding, vibration welding, laser welding, or ultrasonic welding. Thereby, airtightness can be improved.

  Moreover, after insertion, airtightness can also be improved by using a thick resin tube, heat-shrinkable tube, clip or the like that can apply a sufficient tightening force to the overlapping portion.

  The resin tube may have a corrugated region in the middle thereof. Such a corrugated region is a region in which an appropriate region in the middle of the tube body is formed into a corrugated shape, a bellows shape, an accordion shape, a corrugated shape, or the like. By having a region in which a plurality of such wavy folds are arranged in a ring, one side of the ring can be compressed and the other side can be extended outward in that region, so stress fatigue and delamination It is possible to easily bend at any angle without accompanying.

  The resin tube preferably includes a layer made of a polyamide resin composition including a polyamide resin such as nylon 11 or nylon 12, and preferably has a multilayer structure including a barrier layer. PBT, PBN, fluorine resin, PA92 Nylon in which clay is nano-dispersed, EVOH or the like can be used as a resin for forming the barrier layer.

  Further, in the line through which the liquid fuel flows, a configuration in which the conductive layer is included in the innermost layer is preferable for preventing damage due to static electricity.

All or a part of the outer periphery of the resin tube, in consideration of stone shaving, wear with other parts, flame resistance,
Epichlorohydrin rubber, NBR, a mixture of NBR and polyvinyl chloride,
Chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, acrylic rubber (ACM), chloroprene rubber (CR), ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), rubber mixture of NBR and EPDM,
A solid or sponge-like protective member (protector) made of a thermoplastic elastomer such as vinyl chloride, olefin, ester or amide can be provided.
The protective member may be a sponge-like porous body by a known method. By using a porous body, a protective part that is lightweight and excellent in heat insulation can be formed. Moreover, material cost can also be reduced.
Alternatively, the strength may be improved by adding glass fiber or the like.
Although the shape of a protection member is not specifically limited, Usually, it is a block-shaped member which has a recessed part which receives a cylindrical member or a multilayer tube.
In the case of a cylindrical member, a multilayer tube can be inserted later into a cylindrical member prepared in advance, or the cylindrical member can be coated and extruded on the multilayer tube to adhere both together.
In order to bond the two, the adhesive is applied to the inner surface of the protective member or the concave surface as necessary, and the multilayer tube is inserted or fitted into the inner surface, and the multilayer tube and the protective member are integrated with each other. Forming a structure.

The quick connector according to the present invention can be combined with an airtightness improving technique such as an O-ring or welding so that a wall permeation amount of a fuel / gasoline mixed fuel or the like is small and has excellent characteristics such as creep deformation resistance. .
Therefore, the quick connector according to the present invention is useful as an excellent fuel line system capable of flexibly responding to strict fuel emission regulations in combination with a resin tube excellent in fuel barrier properties, preferably a fuel tube according to the present invention.

[Examples and Comparative Examples]
Examples 1-1 to 5, Examples 2-1 to 4, Examples 3-1, 2 and 5, Examples 4-1 to 4,
The polyamide resin composition for fuel pipe parts of the present invention was produced in the intermediate layer and outer layer of Examples 6-1 to 6 and the outer layer of Example 6-7.
In Examples 3-1, 2 and 5, and Examples 4-1 to 4, a fuel pipe joint that is a fuel pipe part of the present invention was manufactured.
In Examples 5-1 to 5, a single-layer fuel tube, which is a fuel piping component of the present invention, is manufactured.
In Examples 6-1 to 5, a three-layer fuel tube, which is a fuel piping component of the present invention, is manufactured.
In Example 7, a gasoline tank and a fuel tube, which are fuel piping parts of the present invention, were manufactured.

(1) Example 1-1 (component A: PX6-1)
In a pressure vessel with an internal volume of about 150 liters equipped with a stirrer, thermometer, torque meter, pressure gauge, raw material inlet directly connected with a diaphragm pump, nitrogen gas inlet, pressure outlet, pressure regulator and polymer outlet.
Mixture of compound a (1,6-hexanediamine) 15.407 kg (132.58 mol) and compound b (2-methyl-1,5-pentanediamine) 811.1 g (6.98 mol) (compound a and compound the molar ratio of b is 95: 5),
After pressurizing the interior of the pressure vessel to 0.5 MPa with nitrogen gas having a purity of 99.9999%,
Next, the operation of releasing nitrogen gas to normal pressure was repeated 5 times, and after nitrogen replacement,
The system was heated while stirring under a sealing pressure.
After bringing the temperature of dibutyl oxalate to 80 ° C. over about 30 minutes,
At the same time, 28.230 kg (139.56 mol) of dibutyl oxalate was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump.
The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C.
Thereafter, the temperature was raised to 330 ° C. over 2 hours.
Meanwhile, the internal pressure was adjusted to 0.75 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 330 ° C., butanol was extracted from the pressure relief port over about 20 minutes, and the internal pressure was brought to normal pressure.
From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, and the reaction was carried out for 4.5 hours.
Thereafter, the stirring was stopped and the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes. Then, the pressure was released to an internal pressure of 0.1 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel.
The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer.
The obtained polyamide was a white tough polymer with ηr = 1.95.

(2) Example 1-2 (component A: PX6-2)
A mixture of 14.717 kg (126.64 mol) of compound a and 1.635 kg (14.07 mol) of compound b (molar ratio of compound a and compound b is 90:10) is charged.
Except for charging 28.462 kg (140.71 mol) of dibutyl oxalate,
Reaction was carried out in the same manner as in Example 1 to obtain polyamide.
The obtained polyamide was a white tough polymer with ηr = 2.05.

(3) Example 1-3 (component A: PX6-3)
A mixture of 12.16 kg (104.64 mol) of compound a and 5.212 kg (44.85 mol) of compound b (the molar ratio of compound a to compound b is 70:30) is charged.
At the same time, 30.238 kg (149.49 mol) of dibutyl oxalate was supplied into the reaction vessel by a diaphragm pump at a flow rate of 1.49 liters / minute over about 17 minutes.
The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C.
Thereafter, the temperature was raised to 290 ° C. over 1.5 hours.
Meanwhile, the internal pressure was adjusted to 0.5 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 290 ° C., butanol was extracted from the pressure relief port over about 20 minutes, and the internal pressure was brought to normal pressure.
The temperature was raised from normal pressure while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 310 ° C. over about 1 hour, and the reaction was carried out at 310 ° C. for 1.5 hours. .
Thereafter, the stirring was stopped and the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes. Then, the pressure was released to an internal pressure of 0.1 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel.
The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer.
The obtained polyamide was a white tough polymer with ηr = 2.40.

(4) Example 1-4 (component A: PX6-4)
A mixture of 10.294 kg (88.583 mol) of compound a and 6.863 kg (59.057 mol) of compound b (molar ratio of compound a to compound b is 60:40) is charged.
29.864 kg (147.64 mol) of dibutyl oxalate was supplied into the reaction vessel at a flow rate of 1.49 liter / min by a diaphragm pump over about 17 minutes, and the temperature was raised.
The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C.
Thereafter, the temperature was raised to 275 ° C. over 1.5 hours.
Meanwhile, the internal pressure was adjusted to 0.5 MPa while extracting the generated butanol from the pressure relief port.
Immediately after the temperature of the polycondensate reached 270 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure.
From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was changed to 290 ° C. over about 1 hour, and the reaction was carried out at 290 ° C. for 2 hours.
Thereafter, the stirring was stopped and the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes. Then, the pressure was released to an internal pressure of 0.1 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel.
The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer.
The obtained polyamide was a white tough polymer, and ηr = 2.68.

(5) Example 1-5 (component A: PX6-5)
A mixture of 8.361 kg (71.947 mol) of compound a and 8.361 kg (71.947 mol) of compound b (molar ratio of compound a and compound b is 50:50),
At the same time, 29.107 kg (143.89 mol) of dibutyl oxalate was supplied into the reaction vessel at a flow rate of 1.49 liters / minute over about 17 minutes by a diaphragm pump.
The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C.
Thereafter, the temperature was raised to 260 ° C. over 1.5 hours.
Meanwhile, the internal pressure was adjusted to 0.5 MPa while extracting the generated butanol from the pressure relief port.
Immediately after the temperature of the polycondensate reached 260 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure.
The temperature was raised from normal pressure while flowing nitrogen gas at 1.5 liters / minute, and the temperature of the polycondensate was changed to 275 ° C. over about 1 hour, and the reaction was carried out at 275 ° C. for 3 hours.
Thereafter, the stirring was stopped and the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes. Then, the pressure was released to an internal pressure of 0.1 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel.
The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer.
The obtained polyamide was a white tough polymer, and ηr = 2.61.

(6) Comparative Example 1-1: (Polyamide resin: PX6-6)
(I) Pre-polycondensation step: The inside of a 1 L separable flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a raw material inlet is replaced with nitrogen gas having a purity of 99.9999%.
500 ml of dehydrated toluene,
1,6-hexanediamine 58.7209 g (0.5053 mol) was charged.
After this separable flask was placed in an oil bath and heated to 50 ° C,
Dibutyl oxalate (102.1956 g, 0.5053 mol) was charged.
Next, the temperature of the oil bath was raised to 130 ° C., and the reaction was carried out for 5 hours under reflux.
Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 50 ml / min.
(Ii) Post-polycondensation step: The prepolymer obtained by the above operation is charged into a glass reaction tube having a diameter of about 35 mmφ equipped with a stirrer, an air cooling tube, and a nitrogen introduction tube, and the pressure inside the reaction tube is reduced to 13.3 Pa or less. Then, the operation of introducing nitrogen gas to normal pressure was repeated 5 times, and then the mixture was transferred to a salt bath maintained at 290 ° C. under a nitrogen stream of 50 ml / min. After the temperature of the salt bath was set to 340 ° C. over 1 hour, the pressure in the container was reduced to about 66.5 Pa, and the reaction was further continued for 2 hours.
Subsequently, after introducing nitrogen gas to normal pressure, it was removed from the salt bath and cooled to room temperature under a nitrogen stream of 50 ml / min to obtain a polyamide resin.
The obtained polymer was a yellow polymer, and ηr = 1.65.

(7) Comparative Examples 1-2-4
As a polyamide resin of a resin composition for fuel piping parts,
Nylon 6 (Ube Industries, UBE nylon 1015B: PA6) (Comparative Example 1-2),
Nylon 66 (Ube Industries, UBE nylon 2020B: PA66) (Comparative Example 1-3) and nylon 12 (Ube Industries, UBESTA3020U: PA12) (Comparative Example 1-4) pellets were used.

(8) Examples 2-1 to 4 and Comparative Examples 4 to 4
In the composition shown in Table 1, PX6-1 produced in Example 1-1,
Glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) and / or carbon fiber (K223SE manufactured by Mitsubishi Chemical) are kneaded in a TEX44 twin screw extruder manufactured by Nippon Steel,
After the strand was cooled and solidified in a cooling water tank, pellets of Example 2-1 were obtained with a pelletizer. In Table 1, glass fiber is described as GF, and carbon fiber is described as CF.
A pellet of Example 2-4 was obtained under the same conditions as in Example 2-1, except that PX6-1 was replaced with PX6-4 manufactured in Example 1-4.
To PX6-2 produced in Example 1-2,
30% by mass of glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) is kneaded in a TEX44 twin screw extruder manufactured by Nippon Steel,
After the strand was cooled and solidified in a cooling water tank, pellets of Example 2-2 were obtained with a pelletizer.
In Example 2-2, Examples 2-3 to 4 and Comparative Example 2-4 were performed under the same conditions except that PX6-2 was replaced with PX6-3 and 4 and PA12 produced in Examples 1-3 and 4, respectively. Pellets were obtained.

(9) Examples 3-1, 2 and 5, Comparative Examples 3-4, Examples 4-1 to 4, Comparative Example 4-4, Examples 4-1 to 4 and Comparative Example 4-4
A plastic joint for fuel piping having an outer diameter of 8 mm, a wall thickness of 2 mm, and a length of 100 mm was manufactured using a 30 mm screw extruder (cylinder temperature 250 to 340 ° C.) manufactured by Nippon Steel.

(10) Examples 5-1 to 5 and Comparative Examples 2 and 4
About the polyamide resins PA6 and PA66 produced in Examples 1-1 to 5 by using an extruder with a screw diameter of 30 mm (cylinder temperature 250 to 340 ° C.) manufactured by Nippon Steel Co., Ltd., an outer diameter of 1/2 inch. A single-layer tube having a thickness of 1 mm was manufactured.

(11) Examples 6-1 to 7 and Comparative Examples 6-2 and 3
Multi-layer tube forming equipment includes an inner layer extruder, an intermediate layer extruder and an outer layer extruder. Resin discharged from these three extruders is collected by an adapter and molded into a tube, and the tube is cooled. A three-layer tube having an inner diameter of 6 mm and an outer diameter of 8 mm was prepared using an apparatus (product name: Platform, manufactured by Plastic Engineering Laboratory Co., Ltd.) consisting of a sizing die and a take-up machine for controlling the size.
Table 3 shows the composition and thickness of the resin composition of the inner layer, intermediate layer, and outer layer of the tube.
In addition, the following was used as a raw material.
Resin r1: Vinylidene fluoride resin (cefal soft, manufactured by Central Glass)
Resin r2: High density polyethylene resin (8600A, manufactured by Tosoh Corporation)
Plasticizer:
Benzenesulfonic acid butyramide (BBSA, manufactured by Proviron)
(In Table 3, it is described as BSBA)
Adhesive: Maleic acid-modified polyethylene (U Bond F1100, manufactured by Ube Industries)

(12) Example 7
Using PX6-1 to PX6-5, PA6, PA66, and PA12 manufactured in Examples 1 to 5, a fuel tank for transporting a gasoline tank and gasoline fuel as fuel piping components was manufactured by injection molding.
Injection molding conditions are
300 ° C when PX6-1 to PX3 are used as the polyamide resin,
In the case of using PX 6-4 to 6 as the polyamide resin, 340 ° C.,
When PA6 is used as a polyamide resin,
290 ° C when PA66 is used as the polyamide resin
23 ° C when PA12 is used as polyamide resin
A test plate was obtained by molding with an electrophotographic apparatus part having a mold temperature of 80 ° C.
The injection molding conditions were: injection pressure: primary pressure 650 kg / cm ² , injection time: 11 seconds, cooling time: 20 seconds.
The gasoline tank and the fuel tube, which are fuel piping parts of the present invention, had a formability equal to or higher than that of PA6, PA66, and PA12.

About the polyamide resin or polyamide resin composition in Examples 1-1 to 5 and Comparative Examples 1 to 4 manufactured or used under the following conditions, relative viscosity, melt viscosity, melting point, 1% weight loss temperature, saturated water absorption rate, resistance to water Chemical properties, hydrolysis resistance, physical properties in dry and wet, liquid or vapor barrier properties (ethanol vapor permeability, E10 permeability coefficient, calcium resistance), mechanical properties, fuel immersion resistance,
In Examples 1-1, 2 and 5, Comparative Examples 1-3 to 4, Examples 2-1 to 4 and Comparative Example 2-4, the Izod impact strength and electrical resistance were measured, so that in the polyamide resin composition The addition effect of glass fiber (inorganic fiber) and carbon fiber (conductive filler) was confirmed.
The results are shown in Table 1.

In Examples 3-1, 2 and 5, Comparative Examples 3-3 to 4, Examples 4-1 to 4 and Comparative Example 4-4, the fuel barrier property of the joint for fuel piping which is a fuel piping component of the present invention (Measure fuel permeation (total permeation and HC permeation)
In Examples 5-1 to 5 and Comparative Examples 5-2 and 4, the vapor barrier properties (moisture permeability) of the single-layer fuel tubes were measured.
The results are shown in Table 2.

In Examples 6-1 to 7 and Comparative Examples 6-2 to 3, the low temperature impact property, fuel barrier property (fuel permeability) and fuel resistance of the three-layer fuel tube were measured.
The results are shown in Table 3.

[Physical property measurement, molding, evaluation conditions]
The following contents were used.

(1) Relative viscosity ηr of polyamide resin
ηr was measured at 25 ° C. using an Ostwald viscometer using a 96% sulfuric acid solution (concentration: 1.0 g / dl) of each polyamide resin of Examples 1-1 to 5 and Comparative Examples 1-1 and 2 did.

(2) Melt Viscosity of Polyamide Resin The melt viscosities of the polyamide resins of Examples 1 to 5 and Comparative Examples 1 and 2 are 25 mm cone plates in a melt viscoelasticity measuring device ARES manufactured by TA Instruments Japan. In the nitrogen,
When PX6-1 to PX3 are used as the polyamide resin, 340 ° C.,
300 ° C when PX6-4-5 is used as the polyamide resin,
In the case of using PA6 as the polyamide resin,
The measurement was performed under conditions of a shear rate of 0.1 ^s-1 .

(3) Melting point of polyamide resin (Tm)
Tm of each polyamide resin of Examples 1-1 to 5 and Comparative Examples 1 to 3 was measured under a nitrogen atmosphere using PYRIS Diamond DSC manufactured by PerkinELmer.
Tm when PX6-1 to 2 and 6 are included as the polyamide resin is
The temperature is raised from 30 ° C. to 350 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run),
After holding at 350 ° C for 3 minutes,
The temperature is decreased to -100 ° C at a rate of 10 ° C / min (referred to as a temperature decrease first run),
Next, the temperature was raised to 350 ° C. at a rate of 10 ° C./min (referred to as a temperature raised second run).
Tm when PX6-3-5, PA6, PA66 and PA12 are included as the polyamide resin is
The temperature is increased from 30 ° C. to 310 ° C. at a rate of 10 ° C./min (referred to as a temperature rising first run),
After holding at 310 ° C for 3 minutes,
The temperature is decreased to -100 ° C at a rate of 10 ° C / min (referred to as a temperature decrease first run),
Next, the temperature was raised to 310 ° C. at a rate of 10 ° C./min (referred to as a temperature rise second run).
The endothermic peak temperature of the elevated temperature second run was defined as Tm.

(4) 1% weight loss temperature Td of polyamide resin
Td of each polyamide resin of Examples 1 to 5 and Comparative Examples 1 to 3 was measured by thermogravimetric analysis (TGA) using THERMOGRAVIMETRIC ANALYZER TGA-50 manufactured by Shimadzu Corporation.
The temperature was raised from room temperature to 500 ° C. at a rate of 10 ° C./min under a nitrogen stream of 20 ml / min, and Td was measured.

(5) Test Film, Plate Molding Conditions (5-1) Test Film Films were formed using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. Examples 1-1 to 5 and Comparative Examples 1-1 to 1-1. A test film for each polyamide resin of No. 3 was obtained.
Under a reduced pressure atmosphere of 500 to 700 Pa,
In the case of using PX6-1-3 as a polyamide resin, 300 ° C.,
In the case of using PX6-4 to 6 as the polyamide resin, 340 ° C.,
When PA6 is used as a polyamide resin,
290 ° C when PA66 is used as the polyamide resin
After 5 minutes of heating and melting,
The film was formed by pressing at 5 MPa for 1 minute.
Next, the reduced-pressure atmosphere was returned to normal pressure, and then cooled and crystallized at room temperature of 5 MPa for 1 minute to obtain a test film.

(5-2) Test plate Resin temperature In the case of using PX6-1 to PX3-3 as the polyamide resin,
In the case of using PX6-4 to 6 as the polyamide resin, 340 ° C.,
When PA6 is used as a polyamide resin,
290 ° C when PA66 is used as the polyamide resin
A test plate was obtained by molding with an electrophotographic apparatus part having a mold temperature of 80 ° C.
The injection molding conditions were: injection pressure: primary pressure 650 kg / cm ² , injection time: 11 seconds, cooling time: 20 seconds.

(6) Saturated water absorption rate of polyamide resin A test film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass about 0.05 g) is immersed in ion-exchanged water at 23 ° C.
The test film was taken out every predetermined time, and the mass of the film was measured.
When the rate of increase in the mass of the test film lasts 3 times within the range of 0.2%, it is judged that the absorption of moisture into the test film has reached saturation,
The saturated water absorption (%) was calculated by the following formula (1) from the mass (Xg) of the test film before being immersed in water and the mass (Yg) of the test film when saturation was reached.
Saturated water absorption (%) = 100 × (Y−X) / X (1)

(7) Chemical resistance of polyamide resin After the test film was immersed in the chemicals listed below for 7 days, the weight residual ratio (%) and changes in the appearance of the film were observed. Tests were conducted on samples immersed in concentrated hydrochloric acid, 64% sulfuric acid, 30% NaOH aqueous solution, and 5% K ₂ MnO ₄ at 23 ° C. and benzyl alcohol at 50 ° C.

(8) Hydrolysis resistance of polyamide resin A test film is placed in an autoclave, and water (pH = 7), 0.5 mol / l sulfuric acid (pH = 1) or 1 mol / l sodium hydroxide aqueous solution (pH = 14). The residual weight ratio (%) and appearance change after treatment at 121 ° C. for 60 minutes were examined.

(9) Mechanical properties of polyamide resin
What was evaluated at 23 ° C. without conditioning immediately after molding was dried,
What was evaluated at 23 ° C. after conditioning at a humidity of 65% and a temperature of 23 ° C. after molding was described in the table as wet.

(9-1) Tensile strength: Measured according to ASTM D638 using a test plate formed into a dumbbell shape of a Type I test piece described in ASTM D638.
(9-2) Flexural modulus: Measured according to ASTM D790 using a test plate.
(9-3) Deflection temperature under load (thermal deformation temperature): Measured with a load of 1.82 MPa in accordance with ASTM D648 using a test plate.

(10) Water absorption rate of polyamide resin Except that it was placed under conditions of 23 ° C. and humidity 65% RH using a test film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass about 0.05 g). (6) The water absorption rate (equilibrium water absorption rate) (%) was calculated according to the method for measuring the saturated water absorption rate.

(11) Ethanol Vapor Permeability Coefficient of Polyamide Resin 50 ml of ethanol was placed in a stainless steel container, and a container covered with a PTFE gasket was covered with a test film and tightened with screw pressure. The cup was placed in a constant temperature bath at 60 ° C., and nitrogen was allowed to flow at 50 ml / min in the bath. The change in weight with time was measured, and when the weight change rate per hour was stabilized, the ethanol vapor transmission coefficient was calculated from the following equation. The transmission area of the sample is 78.5 cm2.
Ethanol vapor transmission coefficient (g · mm / m ² · day)
= [Permeation weight (g) x film thickness (mm)]
/ [Permeation area (mm ² ) × days (day) × pressure (atom)]

(12) E10 Fuel Permeation Coefficient of Polyamide Resin According to JIS Z0208, an E10 fuel permeation test was performed at a measurement ambient temperature of 60 ° C. using a test piece having a diameter of 75 mm and a thickness of 1 mm molded by injection molding.
As a fuel, 10% ethanol was mixed with Fuel C in which isooctane and toluene were mixed at a volume ratio of 1: 1.
The fuel permeation measurement sample surface was placed with the permeation surface facing downward so that the fuel always contacted.
E10 fuel permeability coefficient (g · mm / m ² · day)
= [Permeation weight (g) x film thickness (mm)]
/ [Permeation area (mm ² ) × days (day) × pressure (atom)]
In the case of using PX6-1-3 as a polyamide resin, 300 ° C.,
In the case of using PX6-4 to 6 as the polyamide resin, 340 ° C.,
When PA6 is used as a polyamide resin,
290 ° C when PA66 is used as the polyamide resin
230 ° C when PA12 is used as the polyamide resin
A test plate was obtained by molding with an electrophotographic apparatus part having a mold temperature of 80 ° C.
The injection molding conditions were: injection pressure: primary pressure 650 kg / cm ² , injection time: 11 seconds, cooling time: 20 seconds.

(13) Calcium chloride resistance of polyamide resin The test film was immersed in a saturated calcium chloride aqueous solution at 23 ° C. After one day, the appearance of the test film was visually observed to evaluate the presence or absence of cracks.

(14) Initial Adhesive Strength of Polyamide Resin A test piece (Type I test piece described in ASTM D638) was produced by the following method.
That is, a metal piece made into a half of a mold for producing a Type I test piece is inserted, and polyethylene which has been modified with maleic anhydride is injected and filled into a portion where the metal piece is not inserted.
Next, after the injection-filled maleic anhydride-modified polyethylene is sufficiently cooled, the metal piece in the mold is removed, and the resin to be evaluated is injected into the mold part from which the metal piece has been removed. Fill. In this way, a polyethylene resin in which the upper half of the Type I test piece is modified with maleic anhydride, and the lower half of the Type I test piece is the target resin, and these resins are placed in the center of the Type I test piece. A test piece having the following interface is obtained.
Injection molding conditions are
300 ° C when PX6-1 to PX3 are used as the polyamide resin,
In the case of using PX 6-4 to 6 as the polyamide resin, 340 ° C.,
When PA6 is used as a polyamide resin,
290 ° C when PA66 is used as the polyamide resin
23 ° C when PA12 is used as polyamide resin
20 ° C when polyethylene modified with maleic anhydride is used
A test plate was obtained by molding with an electrophotographic apparatus part having a mold temperature of 80 ° C.
The injection molding conditions were: injection pressure: primary pressure 650 kg / cm ² , injection time: 11 seconds, cooling time: 20 seconds.
Using this test piece, the resin to be evaluated peels off from the boundary surface between polyethylene modified with maleic anhydride at a tensile speed of 50 mm / min and a metal piece or breaks at a portion other than the boundary surface (base material breakdown) ) Was measured as the initial adhesive strength.

(15) Adhesive strength after immersion in fuel of polyamide resin A test piece molded in the same procedure as the evaluation of initial adhesive strength was put in an autoclave, and Fuel C + ethanol 10% mixed fuel was sealed until the test piece was completely immersed. The autoclave was left in a 60 ° C. hot water tank for 350 hours. Thereafter, the maximum tensile strength of the test piece taken out was measured in the same manner as described above, and was taken as the adhesive strength after immersion in fuel.

(16) Izod impact value It measured at 23 degreeC based on ASTMD256 using the plate for a test (test piece dimension 3.2mmx12.7mmx127mm).

(17) Electric resistance Using a test plate (test piece dimensions: 3.2 mm × 12.7 mm × 127 mm), measurement was performed according to ASTM D-257.

(18) Fuel permeation amount of the fuel pipe joint Seal one end of the fuel pipe joint,
Inside, put ethanol / gasoline mixed with Fuel C (isooctane / toluene = 50/50 volume ratio) and ethanol in 90/10 volume ratio,
The remaining end was also sealed.
Then weigh the whole and then put the joint into a 60 ° C. oven,
Measure the weight change,
The fuel permeation amount (which indicates both the total permeation amount and the permeation amount of hydrocarbon components contained therein (HC permeation amount)) was evaluated.

(19) Moisture permeability of single layer fuel tube The single layer fuel tube was cut into a length of 300 mm, filled with calcium chloride as a moisture absorbent, and sealed. Next, this tube was allowed to stand for 10 days or longer in an atmosphere at 40 ° C. and a relative humidity of 90%, and the average daily moisture permeability per unit area was measured.

(20) Low temperature impact property of three-layer tube The low temperature impact property of the obtained multilayer tube was measured in accordance with SAE J844.

(21) Fuel permeability of three-layer tube Seal one end of a three-layer tube cut to 30 cm,
Put alcohol gasoline mixed with commercial gasoline and ethyl alcohol 1: 1 inside.
After sealing the remaining one end, the entire weight was measured, and then the test tube was placed in an oven at 60 ° C., and the change in weight (g / 24 hours) was measured to evaluate the fuel permeability.

(22) Fuel resistance of three-layer tube The surface of the three-layer tube after the fuel permeation test was visually observed to check for cracks.

From Tables 1 to 3, the polyamide resin composition for fuel piping parts of the present invention has low water absorption compared to materials such as nylon 6 and nylon 66, excellent chemical resistance and hydrolysis resistance, and under wet conditions. It has excellent mechanical properties and has a wider moldable temperature range than polyamide resin (PX6-6) using 1,6-hexanediamine alone as a diamine component, and it has excellent melt moldability. It can be seen that a fuel piping component having excellent environmental resistance such as low temperature impact resistance, chemical resistance, and fuel impermeability can be produced by molding it.
In addition, the polyamide resin composition using PX6-6 could not be melt-kneaded and molded because Td-Tm was small.

1 Quick connector 2 Steel tube 3 Plastic tube 4 Flange shape part 5 Retainer 6 O-ring 7 Nipple 8 Jaw part 9 O-ring

Claims (11)

A polyamide resin composition for fuel pipe parts, comprising a polyamide resin (component A),
The component A is composed of a unit derived from a dicarboxylic acid and a unit derived from a diamine,
The dicarboxylic acid comprises oxalic acid (compound a);
The diamine comprises 1,6-hexanediamine (compound b) and 2-methyl-1,5-pentanediamine (compound c);
A polyamide resin composition for fuel pipe parts, wherein the molar ratio of the compound b to the compound c is 99: 1 to 50:50.   Furthermore, the polyamide resin composition for fuel piping components of Claim 1 containing layered silicate.   Furthermore, the polyamide resin composition for fuel piping components of Claim 1 or 2 containing an organic fiber and / or an inorganic filler (however, except a conductive filler).   Furthermore, the polyamide resin composition for fuel piping components of any one of Claims 1-3 containing an electroconductive filler.   A fuel pipe part obtained by molding the polyamide resin composition for a fuel pipe part according to any one of claims 1 to 4.   The fuel piping component according to claim 5, wherein the fuel piping component is a fuel tank component.   The fuel piping component according to claim 5 or 6, wherein the fuel piping component is a fuel tube.   The fuel pipe part according to claim 7, wherein the fuel tube has a layer made of the polyamide resin composition for a fuel pipe part according to any one of claims 1 to 4.   The said fuel tube further contains the layer which consists of a resin composition containing at least 1 sort (s) of resin chosen from the group which consists of a fluororesin, a high density polyethylene resin, PA11 resin, and PA12, and a plasticizer. Fuel piping parts.   The fuel piping component according to claim 5 or 6, wherein the fuel piping component is a joint for fuel piping.   The fuel pipe component according to claim 10, wherein the fuel pipe joint is a fuel pipe quick connector.

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