JP5577576B2 - Polyamide resin molded parts having liquid or vapor barrier properties, fuel tank parts, fuel tubes, joints for fuel piping, quick connectors, and fuel piping parts - Google Patents

Description

  The present invention relates to a polyamide resin molded part having a novel liquid or vapor barrier property. Specifically, the present invention relates to a polyamide resin molded part, a fuel tank part, a fuel tube, a fuel pipe joint, a quick connector, and a fuel pipe part, which are manufactured using a specific polyamide resin and have excellent liquid or vapor barrier properties.

  Crystalline polyamides typified by nylon 6 and nylon 66 are not only used for clothing, industrial materials, or general-purpose engineering plastics, but also for automobiles and electrical products because of their excellent characteristics and ease of melt molding. It is used as a molded part in the field.

  In the field of automobiles and electrical products, in addition to dimensional stability and chemical resistance, molded parts have barrier properties against liquids or vapors such as moisture, alcohol, fluorocarbons such as hydrofluorocarbons, fuels such as gasoline. Desired. However, for example, since nylon 6 has a property of permeating moisture, alcohol, fluorocarbon, gasoline, etc., in order to impart liquid or vapor barrier properties to the molded part, a layered silicate having excellent liquid or vapor barrier properties is used. It is indispensable to use together (for example, patent document 1).

  On the other hand, 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 2). It is expected to be used in fields where the use of conventional polyamide, where the change in physical properties due to water absorption has been problematic, is difficult.

  So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. However, for example, a polyoxamide resin using 1,6-hexanediamine as a diamine component has a melting point (about 320 ° C.) higher than the thermal decomposition temperature (1% weight loss temperature in nitrogen; about 310 ° C.) (non-patent document). 1) Melt polymerization and melt molding were difficult and could not withstand practical use.

  For a polyoxamide resin whose diamine component is 1,9-nonanediamine (hereinafter abbreviated as PA92), L. Franco et al. Discloses a production method and its crystal structure when diethyl oxalate is used as the oxalic acid source ( Non-patent document 2). The PA 92 obtained here is a polymer having an intrinsic viscosity of 0.97 dL / g and a melting point of 246 ° C., but only a low molecular weight substance that cannot form a tough molded article is obtained. In addition, JP-A-5-506466 discloses that PA92 having an intrinsic viscosity of 0.99 dL / g and a melting point of 248 ° C. was produced when dibutyl oxalate was used as the dicarboxylic acid ester ( Patent Document 3). In this case as well, there is a problem that only a low molecular weight body that cannot be formed into a tough molded body is obtained.

The present inventors use oxalic acid as a dicarboxylic acid component, and a polyamide resin using 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a specific ratio as a diamine component has low water absorption, It was disclosed that it is a polyamide resin (PA92C) having a wide melt molding temperature range and excellent properties (Patent Document 4).
However, this polyamide resin uses oxalic acid as the dicarboxylic acid component, and has a specific ratio of three diamines of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component. It is not the polyoxamide resin used in 1.

  In this technical field, it is desired to develop a polyamide resin having a high barrier property against liquid or vapor and to produce a polyamide resin molded part having a liquid or vapor barrier property using the polyamide resin.

JP-A-2-69562 JP 2006-57033 A Special table 5-506466 WO2008 / 072754 S. W. Shalaby., J. Polym. Sci., 11, 1 (1973) L. Franco et al., Macromolecules., 31, 3912 (1988)

  The present invention has been made based on the above circumstances, and the present invention is superior in liquid or vapor barrier properties as compared to a molded part using conventional nylon 6, and has low water absorption, chemical resistance and resistance. Excellent hydrolyzability, etc. Furthermore, it has a wider moldable temperature range than polyamide resin-based molded parts using 1,9-nonanediamine alone as a diamine component, and is excellent in melt moldability. Furthermore, it is found in aliphatic linear polyoxamide resins. It is an object of the present invention to provide a tough polyamide resin molded part having a high molecular weight without impairing low water absorption.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that oxalic acid diester as a oxalic acid source, 1,9-nonanediamine, 2-methyl-1,8-octanediamine as a diamine component, and It has been found that the above problems can be solved by using a polyamide resin composed of 1,6-hexanediamine (hereinafter also referred to as “PA92 / 62T”) for a molded part, and the present invention has been completed.

Specifically, the present invention relates to the following aspects.
[Aspect 1]
The dicarboxylic acid component is composed of succinic acid, and the diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter also referred to as “C9 diamine mixture”) and 1,6-hexanediamine (hereinafter referred to as “C9 diamine mixture”). And is a polyamide resin having a liquid or vapor barrier property, which is prepared using a polyamide resin in which the molar ratio of the C9 diamine mixture to the C6 diamine is 1:99 to 99: 1. Molded parts.

[Aspect 2]
Aspect 1 in which the relative viscosity (ηr) measured at 25 ° C. using a polyamide resin solution having a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent is 1.8 to 6.0. A polyamide resin molded part having a liquid or vapor barrier property described in 1.
[Aspect 3]
1% weight loss temperature in thermogravimetric analysis of the polyamide resin measured at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere, and differential scanning calorimetry measured at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin molded part having a liquid or vapor barrier property according to the aspect 1 or 2, wherein the temperature difference from the melting point measured by the step is 50 ° C or higher.

[Aspect 4]
The liquid or vapor barrier property according to any one of Embodiments 1 to 3, wherein the molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine is 5:95 to 95: 5. Polyamide resin molded parts.
[Aspect 5]
A fuel tank part produced from the polyamide resin molded part according to any one of aspects 1 to 4.
[Aspect 6]
The fuel tank component according to aspect 5, wherein the amino resin end group concentration of the polyamide resin of the polyamide resin molded component is 1.5 × 10 −5 eq / g to 1.0 × 10 −4 eq / g.
[Aspect 7]
The fuel tube according to any one of aspects 1 to 4, wherein the polyamide resin layer includes a layered silicate.
[Aspect 8]
The fuel according to aspect 7, which is a multilayer tube including the polyamide resin layer and a resin layer selected from a resin including a fluororesin, a high-density polyethylene resin, a polyamide 11 resin, and / or a polyamide 12 resin containing a plasticizer. tube.
[Aspect 9]
The joint for fuel piping according to any one of aspects 1 to 4, wherein the joint material further includes a reinforcing material.
[Aspect 10]
The joint for fuel piping according to aspect 9, wherein the joint material further includes a conductive filler.
[Aspect 11]
The joint for fuel piping according to aspect 10, wherein the joint material further includes a reinforcing material and a conductive filler in a weight ratio of 1: 3 to 3: 1.
[Aspect 12]
A quick connector for a fuel pipe, wherein a tubular main body is formed of the joint material according to any one of the embodiments 9-11.
[Aspect 13]
The quick connector for fuel piping according to aspect 12, wherein an O-ring is used as the sealing material.
[Aspect 14]
A fuel piping component in which the quick connector according to aspect 12 is joined to a polyamide resin tube by a welding method selected from spin welding, vibration welding, laser welding, and ultrasonic welding.
[Aspect 15]
The fuel piping component according to claim 7, wherein the polyamide resin tube according to Aspect 14 includes a barrier layer.

  The polyamide resin molded part having liquid or vapor barrier properties of the present invention is superior in liquid or vapor barrier properties compared to conventional molded parts using nylon 6, and has low water absorption, chemical resistance and hydrolysis resistance. Excellent polyamide resin molded parts that have a wider moldable temperature range and better melt moldability than polyamide resin molded parts that use 1,9-nonanediamine alone as the diamine component, and are high molecular weight tough polyamide resin molded parts and fuel tank parts Fuel tubes, fuel pipe joints, quick connectors, and fuel pipe components.

Hereinafter, the present invention will be described in detail.
[Polyamide resin]
The polyamide resin used in the present invention has a dicarboxylic acid component consisting of oxalic acid, a diamine component consisting of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and a C9 diamine mixture. The molar ratio of (1,9-nonanediamine and 2-methyl-1,8-octanediamine) to 1,6-hexanediamine is 1:99 to 99: 1.

  As the oxalic acid source as the dicarboxylic acid source of the polyamide resin used in the present invention, oxalic acid diester is used, and there is no particular limitation as long as it has reactivity with an amino group. Dimethyl oxalate, diethyl oxalate, oxalic acid Di-n- (or i-) propyl, oxalic acid diesters of aliphatic monohydric alcohols such as di-n- (or i-, or t-) butyl oxalate, oxalic acid diesters of alicyclic alcohols such as dicyclohexyl oxalate, diphenyl oxalate, etc. And oxalic acid diesters of aromatic alcohols.

  Among the above 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 preferred, and among them, dibutyl oxalate and diphenyl oxalate are particularly preferred.

  In the polyamide resin used in the present invention, oxalic acid is used as the dicarboxylic acid source, but other dicarboxylic acid components can be blended within a range that does not impair the effects of the present invention. Examples of dicarboxylic acid components other than succinic acid include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3, Aliphatic dicarboxylic acids such as 3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and terephthalic acid , Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid Acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfuric acid Down-4,4'-dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid aromatic dicarboxylic acids such as such alone or may be added any mixtures thereof during the polycondensation reaction. Furthermore, polycarboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid can be used within a range where melt molding is possible.

  The blending amount of the other dicarboxylic acid is not particularly limited as long as the effects of the present invention are not impaired. In general, it is preferably 5 mol% or less with respect to the total amount of the dicarboxylic acid.

  The molar ratio of the 1,9-nonanediamine component to the 2-methyl-1,8-octanediamine component in the C9 diamine mixture used in the polyamide resin of the present invention is generally 1:99 to 99: 1, preferably 5:95 to 95: 5, more preferably 5:95 to 40:60 or 60:40 to 95: 5, especially 5:95 to 30:70 or 70:30 to 90:10. By copolymerizing 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine in the above specific amounts, the moldable temperature range is wide, the melt moldability is excellent, and the water absorption is low. Polyamide having excellent properties, chemical resistance, hydrolysis resistance, transparency and the like can be obtained.

  In the polyamide resin of the present invention, as the diamine component, the C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine) mixed with 1,6-hexanediamine is used. The molar ratio of C9 diamine mixture to 1,6-hexanediamine is 1:99 to 99: 1. By mixing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, the above excellent effect of the polyamide resin (PA92C) comprising oxalic acid as the dicarboxylic acid component and C9 diamine mixture as the diamine component Can be maintained (particularly without impairing melt moldability and low water absorption), the melting point of the polyamide resin can be increased, and particularly the mechanical properties can be improved. The molar ratio of the C9 diamine mixture to 1,6-hexanediamine is preferably 5.1: 94.9 to 99: 1, more preferably 10:90 to 99: 1, and even more preferably 20:80 to 99: 1. It is. In particular, it is preferably 30:70 to 98: 2, and more preferably 30:70 to 90:10 (further 30:70 to 70:30). In this polyamide resin, the change to the melting point appears clearly by copolymerizing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, and the melting point of the resin rises. If 6-hexanediamine is within a molar ratio of 99/1, an acceptable melt moldability can be obtained. If the molar ratio of 1,6-hexanediamine is within 80/20, the melting point of the polyamide resin will be 300 ° C. or lower, and polymerization and molding (melt moldability) will be easier, and within 70/30. It is more preferable because the melting point becomes 280 ° C. or lower and the melt moldability becomes easier.

  The polyamide resin used in the present invention uses 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component, but does not impair the effects of the present invention. Thus, other diamine components can be blended. Other diamine components other than 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine include ethylenediamine, propylenediamine, 1,4-butanediamine, and 1,8-octanediamine. 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1 , 6-hexanediamine, aliphatic diamines such as 5-methyl-1,9-nonanediamine, cyclohexanediamine, methylcyclohexanediamine, and cycloaliphatic diamines such as isophoronediamine, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-diamy Diphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-aromatic diamines diaminodiphenyl ether or the like, etc. alone, or can be added any mixture thereof during the polycondensation reaction.

  Although it will not specifically limit if it is a range which does not impair the effect of this invention as a compounding quantity of said other diamine component, It is preferable that it is 5 mol% or less with respect to the total amount of a diamine component.

[Production method of polyamide resin]
The polyamide resin used in the present invention can be produced by any method known as a method for producing polyamide. According to the study by the present inventors, it is preferable to polymerize the polyamide resin by subjecting diamine and oxalic acid diester to a polycondensation reaction in a batch or continuous manner. Specifically, it is preferable to carry out in the order of (i) pre-polycondensation step and (ii) post-polycondensation step as shown by the following operations.

  (I) Pre-polycondensation step: First, the inside of the reactor is purged with nitrogen, and then diamine (diamine component) and oxalic acid diester (oxalic acid source) are mixed. When mixing, a solvent in which both the diamine and the oxalic acid diester are soluble may be used. The solvent in which both the diamine component and the oxalic acid source are soluble is not particularly limited, but toluene, xylene, trichlorobenzene, phenol, trifluoroethanol, and the like can be used, and particularly, toluene can be 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 of the oxalic acid diester and the diamine is oxalic acid diester / the diamine, 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), more preferably 0. .99 to 1.01 (molar ratio).

  While stirring and / or nitrogen bubbling in the reactor charged with the above raw materials, the temperature is raised under normal pressure. 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. In the temperature rising process, the final temperature of the prepolycondensation step, that is, from 80 to 150 ° C, is finally 220 ° C to 300 ° C, preferably 230 ° C to 280 ° C, more preferably 240 ° C to 270 ° C. Let reach the range. It is preferable to carry out the reaction for 1 to 8 hours including the temperature raising time, preferably 2 to 6 hours. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. The preferable final ultimate pressure in the case of performing the vacuum polymerization is less than 0.1 MPa to 13.3 Pa.

The specific example of the manufacturing method of the polyamide resin used for this invention is demonstrated.
First, the raw oxalic acid diester is charged into the container. The container is not particularly limited as long as it can withstand the temperature and pressure of the polycondensation reaction to be performed later. Thereafter, the container is heated to a temperature at which it is mixed with the raw material diamine, and then the diamine is injected to start the polycondensation reaction. The temperature at which the raw materials are mixed is not particularly limited as long as it is a temperature that is not lower than the melting point and lower than the boiling point of the oxalic acid diester and diamine, and the polyoxamide generated by the polycondensation reaction of the oxalic acid diester and diamine is not thermally decomposed. For example, a mixture of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,6-hexanediamine, and a C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octane) In the case of a polyoxamide resin made from diamine and dibutyl oxalate having a molar ratio of a mixture of diamines) and 1,6-hexanediamine of 1:99 to 99: 1, the mixing temperature is preferably 15 ° C to 300 ° C. When the molar ratio of C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine mixture) and 1,6-hexanediamine is 5:95 to 90:10, it is liquid at room temperature. Or it is more preferable because it is easy to handle because it liquefies only by heating to about 50 ° C. When the mixing temperature is equal to or higher than the boiling point of the alcohol produced by the condensation reaction, it is desirable to use a container equipped with a device for distilling and condensing the alcohol. In addition, when pressure polymerization is performed in the presence of an alcohol generated by a condensation reaction, a pressure vessel is used. The charging ratio of oxalic acid diester and diamine is oxalic acid diester / diamine as described above, 0.8 to 1.2 (molar ratio), preferably 0.91 to 1.09 (molar ratio), more preferably 0.98. -1.02 (molar ratio).

  Next, the inside of the container is heated to a temperature not lower than the melting point of the polyoxamide resin and not higher than the temperature at which it does not decompose. For example, it consists of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and a C9 diamine mixture (of 1,9-nonanediamine and 2-methyl-1,8-octanediamine). Mixture) and 1,6-hexanediamine molar ratio is 50:50, and diamine and dibutyl oxalate having a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 50:50. In the case of a polyoxamide resin made from a raw material, since the melting point is 261 ° C., the temperature is preferably raised from 270 ° C. to 300 ° C. (pressure is 2 MPa to 4 MPa). While distilling off the produced alcohol, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. When the raw materials are mixed in a pressure vessel and subjected to pressure polymerization in the presence of an alcohol produced by a condensation reaction, the pressure is first released while the produced alcohol is distilled off. Thereafter, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. The preferable final pressure in the case of carrying out the vacuum polymerization is 760 to 0.1 Torr. The temperature is preferably 270 to 300 ° C. The alcohol is cooled and liquefied by a water-cooled condenser and recovered.

[Characteristics of polyamide resin]
There is no particular restriction on the molecular weight of the polyamide resin used in the present invention, but the relative viscosity ηr measured at 25 ° C. using a 96% concentrated sulfuric acid solution of 1.0 g / dl is more preferably 1.8 to 6.0. Is a molecular weight in the range of 2.0 to 5.5, particularly preferably in the range of 2.5 to 4.5. When the molecular weight is low, the polyamide resin molded part becomes brittle and the physical properties tend to be lowered. On the other hand, when the molecular weight increases, the melt viscosity increases and the melt moldability tends to deteriorate.

  The polyamide resin used in the present invention uses oxalic acid as the carboxylic acid component and copolymerizes 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component, Compared with a polyamide composed of succinic acid and 1,9-nonanediamine, it is possible to increase the relative viscosity, that is, increase the molecular weight. The moldable temperature range represented by the difference (Td−Tm) between the 1% weight loss temperature (hereinafter abbreviated as Td) and the melting point (hereinafter abbreviated as Tm), which is a substantial thermal decomposition index, is oxalic acid. And a polyamide composed of 1,9-nonanediamine, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even 90 ° C. or higher. The polyamide resin used in the present invention has a Td of preferably 280 ° C. or higher, more preferably 300 ° C. or higher, still more preferably 320 ° C. or higher, and has high heat resistance.

[Polyamide resin molded part with liquid or vapor barrier properties]
In the present specification, the term “polyamide resin molded part having liquid or vapor barrier property” means a part molded using a polyamide resin having a barrier property against liquid or vapor. Examples of the liquid include highly polar liquids such as water and alcohol, and low polar liquids such as fuel such as gasoline, light oil, and fluorocarbon. The vapor of the liquid is raised as the vapor.
The polyamide resin molded part having a liquid or vapor barrier property of the present invention is produced from the above polyamide resin, but the polyamide resin molded part may further contain the following components as optional components in addition to the polyamide resin. it can.

(1) Other polymer The dicarboxylic acid component used in the present invention comprises oxalic acid, the diamine component comprises 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and C9. The polyamide resin in which the molar ratio of the diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine) and 1,6-hexanediamine is 1:99 to 99: 1 impairs the effects of the present invention. To some extent, a part of the polymer can be substituted with other polymer components. Examples of other polymer components include other polyamides such as polyoxamide, aromatic polyamide, aliphatic polyamide, alicyclic polyamide, and polymers other than polyamide, such as thermoplastic polymers and elastomers.

Although it will not specifically limit if it is the range which does not impair the effect of this invention as said substitution ratio by said other polymer, Preferably it is less than 50 mass%, More preferably, it is 30 mass% or less.
Hereinafter, when simply referred to as “polyamide” or “polyamide resin”, the dicarboxylic acid component is composed of oxalic acid, the diamine component is 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1, Polyamide composed of 6-hexanediamine and having a molar ratio of C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine) to 1,6-hexanediamine of 1:99 to 99: 1 It shall refer to the resin.

(2) Additive The polyamide resin molded part having a liquid or vapor barrier property of the present invention can contain other additives as long as the effects of the present invention are not impaired. Other additives include, for example, pigments, dyes, colorants, heat resistance agents, antioxidants, weathering agents, UV absorbers, light stabilizers, lubricants, crystal nucleating agents, crystallization accelerators, mold release agents, and charging agents. Examples thereof include stabilizers, plasticizers, stabilizers such as copper compounds, antistatic agents, flame retardants, glass fibers, lubricants, fillers, reinforcing fibers, reinforcing particles, and foaming agents.

  The method for adding the other polymer and the additive is not particularly limited as long as each of them can be dispersed in the polyamide resin, and the polyamide resin can be added to the polyamide resin at any time without impairing its effect. Can be added. For example, the other polymers and additives can be added immediately after the post polycondensation step of the polyamide resin.

(3) Layered silicate The polyamide resin molded part having a liquid or vapor barrier property of the present invention has a high liquid or vapor barrier property by using the above polyamide resin. By further containing a salt, the liquid or vapor barrier property of the polyamide resin molded part of the present invention can be further 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. Moreover, it is preferable that the said layered silicate is what is uniformly disperse | distributed in the said polyamide resin, each layer maintaining the 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 exhibited, but preferably 0.05 to 10 mass with respect to 100 parts by mass of the polyamide resin. Parts, more preferably 0.05 to 8 parts by mass, particularly preferably 0.05 to 5 parts by mass. When the ratio of the layered silicate is lowered, the effect of the layered silicate is not exhibited, and when the ratio is increased, the melt viscosity becomes extremely high and the formability is deteriorated or the impact resistance tends to be lowered.

  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, and halloysite. It may be what was done.

  Further, in order to disperse the layered silicate in the polyamide resin, 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. As the swelling agent, in the present invention, it is preferable to use 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine.

  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 polyamide resin. 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, 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine are added to widen the space between the layers of the layered silicate in advance. Next, a polyamide raw material can be introduced between the layers, and the raw materials can be polymerized between the layers.

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

  The polyamide resin molded part having a liquid or vapor barrier property of the present invention can be molded by, for example, extrusion molding, blow molding, compression molding, injection molding or the like.

The polyamide resin molded part having a liquid or vapor barrier property of the present invention can be applied to various applications that require a liquid or vapor barrier property.
Applicable applications include, for example, gasoline tanks, alcohol tanks, fuel tubes, fuel strainers, brake oil tanks, clutch oil tanks, power steering oil tanks, fluorocarbon tubes for coolers, fluorocarbon tanks, canisters, air cleaners, intake air Examples include system parts, tire inner liners, tank valves, fuel delivery pipes, quick connectors, EGR parts, oil strainers, and the like.

(4) Formation of fuel tank parts The fuel tank parts of the present invention are molded using conventionally known molding methods such as injection, extrusion, hollow, press, roll, foaming, vacuum / compression, stretching, etc. , Vibration welding method, die slide injection, injection rotary 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, laser welding method, high frequency induction heating welding method, etc. And can be applied to objects. In forming the fuel tank part, the temperature of the polyamide resin is preferably maintained at a temperature that does not change the quality of the polyamide resin.

(5) Configuration and Production of Fuel Tube The fuel tube of the present invention includes the polyamide resin layer described above, and can be used as a single-layer tube. It is preferably used as a multilayer tube laminated with a resin layer. In practical automotive fuel tubes, many multilayer tubes are used.

  As another resin layer used for the multilayer fuel tube for automobiles of the present invention, a layer made of a resin obtained by blending the above plasticizer with a fluororesin, a high density polyethylene resin, a polyamide 11 resin or a polyamide 12 resin is preferable. As the layer serving as the main skeleton of the outermost layer or the other layers, a novel polyamide resin (PA92) provided by the present invention, a polyamide 11 resin, a polyamide 12 resin, or a material obtained by adding a plasticizer to the polyamide resin is used. Is preferred.

  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 gasoline resistance. 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 another resin layer through an contact bonding layer, when adhesiveness with the said composition layer is bad. In addition, the other resin layer may not be a single layer, and may be a laminate of several layers.

  When the fuel tube of the present invention is a multilayer tube, the thickness of the polyamide resin layer of the present invention is preferably 20 to 80%, more preferably 30 to 70% of the wall thickness of the tube. If it is less than 20%, the fuel impermeability of the tube may not be sufficient. Although the upper limit is not limited, 70% or less is preferable in order to satisfy many required characteristics required for the fuel tube at the same time.

  The outer diameter of the multilayer fuel tube for automobiles can be designed in consideration of the flow rate of fuel gasoline, and the wall thickness is the thickness that does not increase gasoline permeability and can maintain the normal tube breaking pressure, and the tube Although it can be designed to be thin enough to maintain flexibility with a satisfactory degree of ease of assembly work and vibration resistance during use, the outer diameter is preferably 4 mm to 15 mm, and the wall thickness is 0 .5 mm to 2 mm is preferable.

  The fuel tube of the present invention preferably contains conductive carbon black in at least one of the constituent layers in an amount of 3 to 30% by weight based on the composition of the layer.

  Examples of the conductive carbon black include acetylene black and ketjen black. Among them, those having a good chain structure and a high aggregation density are preferable.

  As a method for producing the fuel tube of the present invention, extrusion molding is preferably used, and as a method for producing a multilayer fuel tube, for example, extrusion is performed from a number of extruders corresponding to the number of constituent layers or the number of materials. The molten resin is introduced into one multi-layer tube die, and each layer is bonded in the die or immediately after exiting the die, and then manufactured in the same manner as normal tube forming. Also, a single-layer tube is once formed. Then, a method of coating another layer on the outside or inside of the tube can be mentioned.

  The fuel tube of the present invention is excellent in fuel impermeability and fuel resistance, can be increased in molecular weight by melt polymerization, has a wide moldable temperature range of 50 ° C. or more, has excellent melt moldability, and is low Since it is excellent in water absorption, chemical resistance and hydrolysis resistance, it is particularly suitably used as a fuel tube for automobiles.

  It is preferable to add a reinforcing material to the polyamide resin or composition used in the joint material of the present invention.

  Reinforcing materials include glass fibers, carbon fibers, fibrous inorganic materials such as wollastonite and potassium titanate whiskers, organic fibers such as aramid fibers, montmorillonite, talc, mica, calcium carbonate, silica, clay, kaolin, glass powder Inorganic fillers such as glass beads are used.

  The fibrous inorganic material has a fiber diameter of 0.01 to 20 μm, preferably 0.03 to 15 μm, and a fiber cut length of 0.5 to 10 mm, preferably 0.7 to 5 mm.

  In particular, glass fiber has a high reinforcing effect and is preferably used. By strengthening the glass, the creep resistance of the fastening portion is high and deformation does not occur, and a permanent seal becomes possible.

  The amount of the reinforcing material used is 5 to 65% by weight, preferably 10 to 60% by weight, and more preferably 10 to 50% by weight in the polyamide resin or the composition. If it is less than 5% by weight, the mechanical strength of the polyamide is not sufficiently satisfied. If it is more than 65% by weight, the mechanical strength is sufficiently satisfied, but the moldability and surface condition are deteriorated, which is not preferable.

  Moreover, it is preferable to add a conductive filler to the polyamide resin or composition used for the joint material of the present invention. By connecting the conductive joint and the conductive tube to form an electric transportation circuit, it is possible to dissipate static electricity that is generated when transporting fluids such as fuel. It becomes possible.

  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. Among these, carbon black can be suitably 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 particle diameter, 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. A large amount of carbon black is not preferable in terms of impact resistance. From the viewpoint of obtaining excellent electrical conductivity with a smaller amount, carbon black preferably has an average particle size of 500 nm or less, and preferably 5 to 100 nm. More preferably, it is more preferably 10 to 70 nm, and the surface area (BET method) is preferably 10 m 2 / g or more, more preferably 300 m 2 / g or more, and 500 to 1500 m 2 / g. Further, the DBP (dibutyl phthalate) oil absorption is preferably 50 ml / 100 g or more, more preferably 100 ml / 100 g, and even more preferably 300 ml / 100 g or more. The ash content of carbon black is preferably 0.5% or less, and more preferably 0.3% or less. The DBP oil absorption referred to here is a value measured by a method defined in ASTM-D2414. Carbon black having a volatile content of less than 1.0% by weight is more preferred.

  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 the conductive filler to be used, it cannot be specified unconditionally. However, from the viewpoint of balance between conductivity, fluidity, mechanical strength, etc., the entire resin including the polyamide resin is 100 mass. Generally, 2 to 30 parts by weight is preferably selected with respect to parts.

  In addition, the conductive filler has a volume resistance of 109 Ω · cm or less, particularly 106 Ω · cm or less, in the sense of obtaining sufficient antistatic performance, by molding and extruding a polyamide resin composition containing the conductive filler. It is preferable to add a certain amount. However, the blending of the conductive filler tends to cause deterioration of strength and fluidity. Therefore, if the target conductivity level is obtained, it is desirable that the amount of the conductive filler is as small as possible.

  Moreover, it is preferable to mix | blend the said reinforcing material and a conductive filler in the ratio of 1: 3-3: 1 by weight ratio with the polyamide used for the joint material of this invention.

  Furthermore, the polyamide used in the joint material of the present invention includes an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, a lubricant, an inorganic fine particle, an antistatic agent, a flame retardant, and a crystallization as necessary. Accelerators, plasticizers, impact modifiers and the like may be added.

(5) Manufacture of joint material The joint material of the present invention may be manufactured by an injection molding method or any other known method for manufacturing a resin joint.

(6) Quick connector As a specific example of the joint for fuel piping of the present invention, a quick connector for fuel piping in which a cylindrical main body portion is formed of the joint material is 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 in an assembly engaged with 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 has a multilayer structure including a barrier layer in addition to a polyamide layer such as nylon 11 or nylon 12, and PBT, PBN, fluorine resin, PA92, nylon in which clay is nano-dispersed, EVOH, and the like are used as a barrier. It can be used as a resin for forming a 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 is made of epichlorohydrin rubber, NBR, a mixture of NBR and polyvinyl chloride, chlorosulfonated polyethylene rubber, chlorinated polyethylene in consideration of abrasion with stone, other parts, and flame resistance. Rubber, acrylic rubber (ACM), chloroprene rubber (CR), ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), rubber mixture of NBR and EPDM, vinyl chloride, olefin, ester, amide A solid or sponge-like protective member (protector) made of a thermoplastic elastomer or the like can be disposed. 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, it is useful as an excellent fuel line system that can flexibly cope with strict fuel emission regulations in combination with a multilayer tube having excellent barrier properties.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these Examples.

[Physical property measurement, molding, evaluation method]
The characteristic value was measured by the following method.
(1) Relative viscosity (ηr)
ηr was measured at 25 ° C. with an Ostwald viscometer using a 96% sulfuric acid solution of polyamide (concentration: 1.0 g / dl).

(2) Melting point (Tm) and crystallization temperature (Tc)
Tm and Tc were measured under a nitrogen atmosphere using a PYRIS Diamond DSC manufactured by PerkinELmer. The temperature was raised from 30 ° C. to 300 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 300 ° C. for 3 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first). Then, the temperature was raised to 300 ° C. at a rate of 10 ° C./min (called a temperature rising second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(3) 1% weight loss temperature (Td)
Td 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.
(4) Melt viscosity Melt viscosity was measured by attaching a 25mm cone plate to a melt viscoelasticity measuring device ARES manufactured by TA Instruments Japan Co., Ltd. Measured under conditions.

(5) Film formation A film was formed from the pellets using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. In a reduced pressure atmosphere of 500 to 700 Pa, the film is heated and melted at 290 ° C. (resin temperature 260 ° C. for PA6, resin temperature 290 ° C. for PA66, resin temperature 230 ° C. for PA12) for 5 minutes, then pressed at 5 MPa for 1 minute. did. 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 film.

(6) Saturated water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass of about 0.05 g) formed under the conditions of (5) above is immersed in ion-exchanged water at 23 ° C., and every predetermined time. The film was taken out and the mass of the film was measured. When the rate of increase in the film mass lasts 3 times within the range of 0.2%, it is judged that the absorption of moisture into the polyamide resin film has reached saturation, and the mass (Xg) of the film before being immersed in water The saturated water absorption (%) was calculated from the mass (Yg) of the film when reaching saturation with the following equation (1).
Saturated water absorption (%) = 100 × (Y−X) / X (1)

(7) Chemical Resistance After immersing the polyamide hot press film obtained by the present invention in the chemicals listed below for 7 days at 23 ° C., changes in the residual mass (%) and appearance of the film were observed. Concentrated hydrochloric acid, 64% sulfuric acid, and glacial acetic acid were tested.

(8) Hydrolysis resistance A hot press film was prepared from the material of the polyamide resin molded part of the present invention. The hot press film was placed in an autoclave, and water (pH = 7), 0.5 mol / l sulfuric acid (pH = In 1) or 1 mol / l sodium hydroxide aqueous solution (pH = 14), the weight residual ratio (%) and appearance change after treatment at 121 ° C. for 60 minutes were examined.

(9) Mechanical properties [1] to [4] shown below are measured using a resin temperature of 290 ° C. (resin temperature 260 ° C. for PA6, resin temperature 290 ° C. for PA66, and resin temperature 230 ° C. for PA12). ), And was molded by injection molding at a mold temperature of 80 ° C. The data measured at 23 ° C. after the molding was shown in the table as dry, the moisture was adjusted at a humidity of 65% RH after molding, and the data measured at 23 ° C. was shown in the table.
[1] Tensile yield strength or tensile strength: Measured according to ASTM D638 using a Type I test piece described in ASTM D638. The data measured at 23 ° C. after the molding was shown in the table as dry, the moisture was adjusted at a humidity of 65% RH after molding, and the data measured at 23 ° C. was shown in the table.
[2] Flexural modulus: Measured according to ASTM D790 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm.
[3] Izod impact strength: Measured at 23 ° C. in accordance with ASTM D256 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm.
[4] Deflection temperature under load (thermal deformation temperature): Measured at a load of 1.82 MPa in accordance with ASTM D648 using a test piece having a test piece size of 3.2 mm × 12.7 mm × 127 mm.

(10) Water absorption rate The water absorption rate (%) was calculated according to the measurement method of (6) saturated water absorption rate, except that it was placed under conditions of 23 ° C. and humidity 65% RH.

(11) Ethanol vapor permeability coefficient 50 ml of ethanol was put in a stainless steel container, and the container covered with a PTFE gasket was covered with a film molded under the conditions of (5) 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) × film thickness (mm)] / [permeation area (mm 2) × days (day) × pressure (atom)]

(12) E10 Fuel Permeability Coefficient According to JIS Z0208, an E10 fuel permeability test was performed at a measurement ambient temperature of 60 ° C. using a test piece of φ75 mm and thickness 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. Further, the fuel permeation measurement sample surface was placed with the permeation surface facing downward so that the fuel was always in contact.
E10 fuel permeability coefficient (g · mm / m 2 · day) = [permeation weight (g) × film thickness (mm)] / [permeation area (mm 2) × days (day) × pressure (atom)]

(13) Moisture permeability A tube having an outer diameter of ½ inch and a thickness of 1 mm was prepared using an extruder with a screw diameter of 30 mm (cylinder temperature of 260 to 290 ° C.) manufactured by Nippon Steel. The tube was cut to a length of 300 mm, filled with calcium chloride as a water 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.

(14) Calcium chloride resistance A film molded under the condition (5) was immersed in a saturated calcium chloride aqueous solution at 23 ° C. After one day, the appearance of the film was visually observed to evaluate the presence or absence of cracks.

(15) Initial Adhesive Strength A test piece (Type I test piece described in ASTM D638) in which the component 1 and the component 2 were joined by the following method was produced. That is, a metal piece having the shape of part 2 described later was inserted into a mold, and part 1 was molded using polyethylene modified with maleic anhydride. Next, the component 1 was sufficiently cooled and then inserted into a mold, and a test piece was obtained by molding into the shape of the component 2 using a resin to be evaluated. Using this test piece, measure the maximum tensile strength until peeling from the interface between parts 1 and 2 or breaking at a part other than the interface (base material failure) at a tensile speed of 50 mm / min. It was.

(16) Adhesive strength after immersion in fuel A test piece molded in the same procedure as the evaluation of initial adhesive strength was placed 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.

(17) Tube low-temperature impact resistance As an apparatus for forming a multilayer tube, it is equipped with an inner layer extruder, an intermediate layer extruder and an outer layer extruder, and the resin discharged from these three extruders is collected by an adapter into a tube shape. A multi-layer tube having an inner diameter of 6 mm and an outer diameter of 8 mm was prepared using an apparatus comprising a die to be molded, a sizing die for cooling the tube and controlling the dimensions, and a take-up machine. The thicknesses of the inner layer, intermediate layer and outer layer of the tube are shown in Table 2. The low temperature impact property of the obtained multilayer tube was measured according to SAE J844.

(18) Fuel permeability Seal one end of the tube cut to 30cm, put alcohol gasoline mixed with commercial gasoline and ethyl alcohol 1: 1 into the inside, seal the remaining one end, and measure the total weight. Then, the test tube was put in an oven at 60 ° C., and the change in weight (g / 24 hours) was measured to evaluate the fuel permeability.

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

(20) Fuel permeability A joint with an outer diameter of 8 mm, a wall thickness of 2 mm, and a length of 100 mm is prepared, one end of which is sealed, and Fuel C (isooctane / toluene = 50/50 volume ratio) and ethanol are 90/10 volume inside. The ethanol / gasoline mixed to the ratio was added and the remaining end was sealed. Then, the whole weight is measured, then the joint is put in an oven at 60 ° C., the change in weight is measured, and the fuel permeability (permeation amount and the amount of hydrocarbon components contained therein (HC amount) Both are shown).

(21) Electrical resistance Measured according to ASTM D-257.

[Production Example 1: PA9262-1]
A stirrer, thermometer, torque meter, pressure gauge, raw material inlet directly connected to the diaphragm pump, nitrogen gas inlet, pressure relief port, pressure regulator, and polymer outlet are placed in a pressure vessel with an internal volume of about 150 liters. The operation of charging 28.230 kg (139.56 mol) of dibutyl acid, pressurizing the inside of the pressure vessel to 0.5 MPa with nitrogen gas having a purity of 99.9999%, and then releasing nitrogen gas to normal pressure After repeating nitrogen substitution 5 times, the system was heated while stirring under a sealing pressure. After bringing the temperature of dibutyl oxalate to 100 ° C. over about 30 minutes, 1.241 kg (7.84 mol) of 1,9-nonanediamine and 19.639 kg (124.04 mol) of 2-methyl-1,8-octanediamine were obtained. ) And 0.893 kg (7.68 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine is 5.62). : 88.88: 5.50) 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 235 ° C. over 1 hour. 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 235 ° 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 brought to 260 ° C. over about 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 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 = 3.13.

[Production Example 2: PA9266-2]
28.462 kg (140.71 mol) of dibutyl oxalate was charged, and 16.448 kg (103.88 mol) of 1,9-nonanediamine and 2.903 kg (18.34 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 2.150 kg (18.50 mol) of 1,6-hexanediamine (molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 73.83: 13 0.03: 13.14) was reacted in the same manner as in Production Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer with ηr = 2.97.

[Production Example 3: PA9262-3]
30.238 kg (149.49 mol) of dibutyl oxalate was charged, and 4.486 kg (28.33 mol) of 1,9-nonanediamine and 4.486 kg (28.33 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 10.79 kg (92.85 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 18.95: 18 .95: 62.10) 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, 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 270 ° C. over 1.5 hours. Meanwhile, the internal pressure was adjusted to 1.00 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 285 ° C. over about 1 hour, and the reaction was carried out at 285 ° C. for 1.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 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 = 2.88.

[Production Example 4: PA9262-4]
29.864 kg (147.64 mol) of dibutyl oxalate was charged, and 5.598 kg (35.36 mol) of 1,9-nonanediamine and 5.598 kg (35.36 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 8.941 kg (76.92 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 23.95: 23 .95: 52.10) 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, 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 250 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 1.00 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 250 ° 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 increased to 270 ° C. over about 1 hour and reacted at 270 ° C. for 2 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 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 = 2.83.

[Production Example 5: PA9262-5]
29.107 kg (143.89 mol) of dibutyl oxalate was charged, and 5.641 kg (35.63 mol) of 1,9-nonanediamine and 10.028 kg (63.34 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 5.223 kg (44.93 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 24.76: 44. .02: 31.22) 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 250 ° C. over 1 hour. 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 240 ° 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 adjusted to 265 ° C. over about 1 hour, and the reaction was carried out at 265 ° C. for 3 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 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 = 3.11.

[Reference Production Example 1: PA92C]
A mixture of 11.11 kg (70.2 mol) of 1,9-nonanediamine and 11.11 kg (70.2 mol) of 2-methyl-1,8-octanediamine was charged with 28.40 kg (140.4 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, and at the same time 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 235 ° C. over 1 hour. 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 235 ° 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 brought to 260 ° C. over about 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 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 = 3.35.

[Comparative Production Example 1: Production of PA92]
Using only 22.25 kg (140.4 mol) of 1,9-nonanediamine as a diamine raw material, a reaction was carried out in the same manner as in Production Example 1 to obtain a polyamide. The obtained polymer was a yellowish white polymer, and ηr = 2.78.

  Polyamide PA92 / 62T-1 to PA92 / 62T-5, PA92C, PA92, and nylon 6 (manufactured by Ube Industries, UBE nylon 1015B: PA6) produced in Production Examples 1-5, Reference Production Example 1 and Comparative Production Example 1. For nylon 66 (Ube Industries, UBE nylon 2020B: PA66) and nylon 12 (Ube Industries, UBESTA3020U: PA12), relative viscosity, melting point, crystallization temperature, 1% weight loss temperature, melt viscosity, saturated water absorption, resistance to water Chemical properties, hydrolysis resistance, mechanical properties in dry and wet conditions were measured. The results are shown in Table 1.

  From Table 1, the polyamide resin molded part of the present invention has low water absorption compared to nylon 6, nylon 66 and nylon 12, excellent chemical resistance and hydrolysis resistance, and mechanical properties under wet conditions. It can be seen that it is excellent and has a moldable temperature range wider than that of a polyamide resin (PA92) using 1,9-nonanediamine alone as a diamine component, is excellent in melt moldability, and is a tough molded body having a high molecular weight.

[Examples 1-5, Comparative Examples 1-2]
Table 2 shows the liquid or vapor barrier properties of PA92 / 62T-1 to PA92 / 62T-5 prepared in Production Examples 1 to 5, and PA6 of Comparative Example 1 and PA12 of Comparative Example 2.

[Example 6: Production of polyamide resin molded part]
Gasoline tanks and fuel tubes were produced by injection molding using PA92 / 62T-1 to PA92 / 62T-5 prepared in Production Examples 1 to 5 and the above-mentioned PA6, PA66 and PA12. PA92 / 62T-1 to PA92 / 62T-5 had the same or better moldability as PA6, PA66, and PA12.

  Various evaluation shown in Table 2 was performed using PA92 / 62T-1 to PA92 / 62T-5 prepared above and PA6 described above.

[Examples 7 to 13, Comparative Examples 3 to 4]
Polyamide PA92 / 62T-1 to PA92 / 62T-5 produced in Production Examples 1 to 5, Reference Production Example 1 and Comparative Production Example 1, nylon 6 (Ube Industries, UBE nylon 1015B: PA6), and nylon 12 (Ube) Using a mixture of Kosan, UBESTA3020U: PA12) and the components shown in Table 2, a fuel tube having a layer structure shown in Table 4 was produced by coextrusion. In 42, PA12 is nylon 12, benzenesulfonic acid butyramide is a plasticizer, and U-bond made by Ube Industries is maleic acid-modified polyethylene (U-bond F1100).

The low temperature impact property and fuel permeability of this fuel tube were evaluated. The surface of the tube after the fuel permeation test was visually observed to check for the presence of cracks, but no cracks were observed in any of the examples and comparative examples.
The evaluation results are shown in Table 4.

[Examples 14 to 20, Comparative Examples 5 to 7]
Example 14
Test beads according to ASTM standards were molded using PA92 / 62T-1, and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. The “diamine component ratio” in Table 5 is the composition ratio of 1,9-nonanediamine / 1,8-methyl-2-octadiamine / 1,8-methyl-2-octadiamine (in Examples 2 to 7 below) Same as Table 5) As shown in Table 5, the required rigidity of the connector is better than nylon 12, and is a physically suitable joint. Also, it has excellent fuel barrier properties from fuel permeation tests, especially harmful hydrocarbon components. It was shown that the barrier property is excellent.

Example 15
Test beads according to ASTM standards were molded using PA92 / 62T-2, and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

Example 16
Test beads according to ASTM standards were molded using PA92 / 62T-5, and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

Example 17
30% by mass of glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) with PA92 / 62T-1 is kneaded with a TEX44 twin-screw extruder manufactured by Nippon Tsuna, and the strand is cooled and solidified in a cooling water tank, and then a pelletizer. A pellet-like sample was obtained. Test beads according to ASTM standards were molded using this sample, and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

Example 18
30 mass% of glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) is kneaded with PA92 / 62T using a TEX44 twin-screw extruder manufactured by Nippon Tsuna Co., and the strand is cooled and solidified in a cooling water tank, followed by a pelletizer. A pellet sample was obtained. Test beads according to the ASTM standard were molded using this sample, and mechanical properties (dry and wet bending elastic modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

Example 19
15% by mass of glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) and 15% by mass of carbon fiber (K223SE manufactured by Mitsubishi Chemical) are kneaded with PA92 / 62T using a TEX44 twin-screw extruder manufactured by Tuna, Japan. After cooling and solidifying in a cooling water tank, a pellet-like sample was obtained with a pelletizer. Test beads according to the ASTM standard were molded using this sample, and mechanical properties (dry and wet bending elastic modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

Example 20
A glass fiber (CS-3J-265S manufactured by Nitto Boseki Co., Ltd.) 15% by weight and carbon fiber (K223SE manufactured by Mitsubishi Chemical Co., Ltd.) 15% by mass are kneaded with PA92 / 62T with a TEX44 twin-screw extruder manufactured by Nippon Steel Corporation. After cooling and solidifying in a cooling water tank, a pellet-like sample was obtained with a pelletizer. Test beads according to the ASTM standard were molded using this sample, and mechanical properties (dry and wet bending elastic modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5. As shown in Table 5, the required rigidity of the connector is better than nylon 12, and it is a physically suitable joint. Also, it has excellent fuel barrier properties from the fuel permeation test, especially for harmful hydrocarbon component barrier properties. It was shown to be excellent.

[Comparative Example 5]
Test beads according to ASTM standards were molded with nylon 12 (Ube Industries 3020U), and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5.

[Comparative Example 6]
Test beads according to ASTM standards were molded with nylon 12 containing glass fiber 30% by mass (3024GC6 manufactured by Ube Industries), and mechanical properties (dry and wet bending elastic modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5.

[Comparative Example 7]
Test beads in accordance with the ASTM standard were molded with nylon 66 (Ube Industries 2020B), and mechanical properties (dry and wet flexural modulus, Izod impact value) and electrical resistance were measured. Moreover, the joint was shape | molded and the fuel permeability was measured. The results are shown in Table 5.

  The polyamide resin molded part having liquid or vapor barrier properties of the present invention is superior in liquid or vapor barrier properties compared to conventional molded parts using nylon 6, and has low water absorption, chemical resistance and hydrolysis resistance. It has excellent moldability, etc., and has a wider moldable temperature range and excellent melt moldability than polyamide resin molded parts using 1,9-nonanediamine alone as a diamine component. It can be used widely as a polyamide resin molded part with liquid or vapor barrier properties, such as strainers, various covers, fuel tank parts, fuel tubes, fuel pipe joints, quick connectors, and fuel pipe parts. Useful.

A cross-sectional view of a typical quick connector is shown.

Explanation of symbols

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 (3)

The dicarboxylic acid component consists of oxalic acid,
The diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter also referred to as “C9 diamine mixture”) and 1,6-hexanediamine (hereinafter also referred to as “C6 diamine”). )
The molar ratio of the C9 diamine mixture and C6 diamine 1: 99 to 99: Ri 1 der,
The molar ratio of the 2-methyl-1,8-octane diamine and the 1,9 is 5:95 to 95: 5 der Ru polyamide resin manufactured by using a polyamide with a liquid or vapor barrier properties Plastic molded parts.   The relative viscosity (ηr) of the polyamide resin measured at 25 ° C. using a polyamide resin solution having a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent is 1.8 to 6.0. 2. A polyamide resin molded part having a liquid or vapor barrier property according to 1.   1% weight loss temperature in thermogravimetric analysis of the polyamide resin measured at a heating rate of 10 ° C./min in a nitrogen atmosphere, and differential scanning calorimetry measured at a heating rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin molded part having a liquid or vapor barrier property according to claim 1 or 2, wherein the temperature difference from the melting point measured by (1) is 50 ° C or more.

Images