JP2002338803A - Polyamide resin composition excellent in fuel resistance at welded section and fuel member using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition which exhibits high weld strength and barrier properties without detriment to the characteristics inherent in a crystalline polyamide resin and can be used for preparing a large-size molded item or a part having a complicated shape without depending on a special molding machine or a special post-processing method; and a fuel member excellent in the fuel resistance of a welded section, especially excellent in the fuel resistance of a welded section over a long time. SOLUTION: This polyamide resin composition, excellent in the fuel resistance of a welded section, comprises (A) 100 pts.wt. crystalline polyamide resin of which the terminal amino group concentration is higher than the terminal carboxyl group concentration and (B) 0.05-10 pts.wt. layered silicate homogeneously dispersed in the polyamide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition excellent in the fuel resistance of a welded portion, and a fuel component using the same. More specifically, the present invention relates to a polyamide resin composition having excellent fuel permeation resistance and excellent fuel resistance at a welded portion for a long period of time, and a fuel component using the same.

[0002]

2. Description of the Related Art Conventionally, for safety and environmental measures, it has been required to reduce the amount of fuel volatilized from a wall or a connection portion of a fuel tank or an accessory. For example, in the automotive field, a fuel tank body of an automobile is made of a high-density polyethylene (H
Although the fuel tank made of resin (which may be referred to as DPE resin) is widely used, in the case of the fuel tank made of resin, a method of sulfonating the resin to reduce the amount of fuel permeated from the tank body (SO ₃ treatment, Sho 46-23914 JP), a method of fluorine treatment (F ₂ process), JP method (JP-B 55-49989 that a hollow molded product having a multilayer structure of a barrier resin), the continuous matrix phase of polyethylene A method of dispersing a barrier resin such as polyamide in a flake shape (Japanese Patent Publication No. 60-14695) has been developed. In particular, recently, H
A resin fuel tank having a multilayer structure in which an outer layer of DPE resin is formed and an inner layer of a polyamide resin or an ethylene vinyl alcohol copolymer having excellent fuel gas barrier properties is formed inside the fuel tank is becoming popular. .

However, even if the amount of permeation of fuel from the fuel tank body is reduced by the above method or the like, the permeation amount from various parts (for example, valves and the like) attached to the fuel tank is large, This is an obstacle to reducing the amount of volatilization from the entire parts for use. This is because various parts attached to the fuel tank are made of high-density polyethylene, the same material as the fuel tank, in order to obtain sufficient adhesive strength with the fuel tank. Because it is inferior.

Therefore, it has been considered to manufacture various parts attached to the fuel tank from a polyamide resin or the like having excellent fuel permeability. However, polyethylene and polyamide are originally poor in adhesiveness. There was a problem that sufficient adhesive strength could not be obtained.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to have excellent fuel permeation resistance and excellent fuel resistance of a welded part, particularly, fuel resistance of a welded part over a long period of time. An object of the present invention is to provide a polyamide resin composition and a fuel component using the same.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve this problem and found that (A) 100 parts by weight of a crystalline polyamide resin in which the concentration of amino terminal groups> the concentration of carboxyl terminal groups and (B) The present inventors have found that the object can be achieved by using a polyamide resin composition comprising 0.05 to 10 parts by weight of a layered silicate uniformly dispersed in the polyamide resin, and arrived at the present invention.

That is, the present invention relates to (A) 100 parts by weight of a crystalline polyamide resin having an amino terminal group concentration> a carboxyl terminal group concentration, and (B) a layered silicate uniformly dispersed in the polyamide resin. The present invention relates to a polyamide resin composition consisting of 05 to 10 parts by weight and having excellent fuel resistance at a welded portion. In addition, the present invention provides (A) 100 parts by weight of a crystalline polyamide resin having an amino terminal group concentration> a carboxyl terminal group concentration and (B) a layered silicate 0.05 to 10 dispersed uniformly in the polyamide resin. The present invention relates to a fuel component using a polyamide resin composition consisting of parts by weight and having excellent fuel resistance at a welded portion.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The crystalline polyamide resin of the present invention has an amino terminal group concentration higher than a carboxyl terminal group concentration. Also, it is desirable that the amino terminal group concentration is 50 meq. Or more, preferably 60 meq. Or more per 1 kg of the polymer. When the amino terminal group concentration is excessive, when it is welded to a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, the weld strength becomes excellent, and excellent fuel resistance is exhibited.

The crystalline polyamide resin of the present invention includes:
An aliphatic polyamide resin comprising an aliphatic diamine and an aliphatic dicarboxylic acid, or a lactam or an aminocarboxylic acid is preferred.

The monomer components of the aliphatic polyamide resin include an aliphatic diamine having 4 to 12 carbon atoms and an aliphatic diamine having 6 to 1 carbon atoms.
2 aliphatic dicarboxylic acids, or lactams having 6 to 12 carbon atoms or aminocarboxylic acids having 6 to 12 carbon atoms. Specific examples of the aliphatic diamine include tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and the like. Specific examples of the aliphatic dicarboxylic acid include adipic acid , Heptanedicarboxylic acid, octanedicarboxylic acid, nonanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid and the like, and a preferable combination of aliphatic diamine and aliphatic dicarboxylic acid is an equimolar salt of hexamethylenediamine and adipic acid. . Examples of lactams include α
-Pyrrolidone, ε-caprolactam, ω-laurolactam, ε-enantholactam and the like. Specific examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-amino Dodecanoic acid and the like can be mentioned, but 6-aminocaproic acid, 12-aminododecanoic acid, ε-caprolactam and laurolactam are preferred. The aliphatic polyamide-forming monomer can be used alone or as a mixture of two or more components.

Specific examples of the aliphatic polyamide resin formed from these monomer components include nylon 6, nylon 66, and nylon 12, which may be a homopolymer or a copolymer of two or more.

The crystalline polyamide resin of the present invention is preferably a crystalline semi-aromatic polyamide resin containing at least one aromatic monomer component. As a crystalline semi-aromatic polyamide resin containing one or more aromatic monomer components,
Copolymerized polyamide resins containing at least one aromatic monomer component such as an aromatic dicarboxylic acid component such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid are exemplified.
Preferably, it is a crystalline semi-aromatic copolymer polyamide resin containing at least one aromatic monomer component and having a melting point of 260 ° C. or more and less than 320 ° C., more preferably at least one aromatic monomer component, Melting point is 290 ℃ or more and 316 ℃
Less than a crystalline semi-aromatic copolymerized polyamide resin. Preferred combinations of crystalline semi-aromatic copolymerized polyamide resins containing at least one aromatic monomer component include equimolar salts of aliphatic diamine and aliphatic dicarboxylic acid, and equimolar salts of aliphatic diamine and aromatic dicarboxylic acid. And / or a crystalline copolymerized polyamide resin comprising an aliphatic polyamide-forming monomer.

The aliphatic diamine is defined as having 4 to 12 carbon atoms.
And aliphatic methylene diamines such as tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethylenediamine, undecamethylene diamine, and dodecamethylene diamine. Aliphatic dicarboxylic acids are aliphatic dicarboxylic acids having 6 to 12 carbon atoms, and include adipic acid, heptanedicarboxylic acid, octanedicarboxylic acid, nonanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and the like. A preferred combination is an equimolar salt of hexamethylenediamine and adipic acid.

The aromatic dicarboxylic acid includes terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and the like, and a preferred combination is an equimolar salt of hexamethylenediamine and terephthalic acid.

As the aliphatic-forming monomer, a compound having 6 to 6 carbon atoms is used.
12 aminocarboxylic acids and lactams having 6 to 12 carbon atoms, 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, α-pyrrolidone, ε-caprolactam, laurolactam , Ε-enantholactam and the like,
Aminocaproic acid, 12-aminododecanoic acid, ε-caprolactam and laurolactam are preferred. The aliphatic polyamide-forming monomer may be used alone or as a mixture of two or more components.

The amounts used are 30 to 70% by weight of an equimolar salt of hexamethylenediamine and adipic acid, 70 to 30% by weight of an equimolar salt of hexamethylenediamine and terephthalic acid, and 0 to 15% by weight of an aliphatic polyamide-forming monomer. %, Preferably 35 to 55% by weight of an equimolar salt of hexamethylenediamine and adipic acid, 65 to 45% by weight of an equimolar salt of hexamethylenediamine and terephthalic acid, and 0 to 10% by weight of an aliphatic polyamide-forming monomer. is there.

Although the degree of polymerization of the crystalline polyamide resin in the present invention is not particularly limited, 1 g of the polymer is dissolved in 100 ml of 96% concentrated sulfuric acid, and the relative viscosity measured at 25 ° C. is 1.8 to 5.0. It is more preferably, and more preferably 2.0 to 3.0. When the relative viscosity is higher than the upper limit of the above numerical value, the workability is significantly impaired.

The process for producing a polyamide resin according to the present invention, wherein the amino terminal group concentration is higher than the carboxyl terminal group concentration, comprises:
Although not particularly limited, it can be obtained by incorporating a diamine compound during extrusion kneading of the composition during or after polymerization. If it is produced at the time of melt polymerization, a method of polymerizing by adding an excess of diamine monomer at the time of charging the raw material, a method of adding and polymerizing a diamine compound other than the raw material monomer and the raw material monomer at the time of charging the raw material, and polymerizing a polyamide having a predetermined molecular weight After that, a method is used in which a diamine compound is added just before the polymer is extracted from the polymerization tank so that the target terminal group concentration is balanced. If it is manufactured after the polymerization, a method of melting and kneading the polyamide resin and the diamine compound after the polymerization so as to achieve the target terminal group concentration balance is used.

Specific examples of the diamine compound include, in addition to those used as monomers of the above-mentioned polyamide resin, aliphatic diamines such as methylenediamine, ethylenediamine, trimethylenediamine, and aromatic diamines such as naphthalenediamine and meta-xylylenediamine. Diamines are used, and preferably hexamethylenediamine, dodecamethylenediamine, and meta-xylylenediamine.

In the polyamide resin composition of the present invention, the layered silicate is uniformly dispersed in the polyamide resin.
Examples of the layered silicate include a layered phyllosilicate composed of a layer of magnesium silicate or aluminum silicate.

Specific examples of the layered phyllosilicate include smectite clay minerals such as montmorillonite, saponite, paiderite, nontronite, hectorite, and stippite, vermiculite, and hallocite. These may be natural or synthetic. Of these, montmorillonite is preferred.

It is desirable that the layered silicate is uniformly dispersed in the polyamide resin. The state in which the layered silicate is uniformly dispersed means that the length of one side is 0.002 to 1
When the layered silicate having a thickness of 6 to 20 ° is dispersed in the polyamide resin, each of them has an average interlayer distance of 20 ° or more and is uniformly dispersed. Here, the interlayer distance refers to the distance between the centers of gravity of the layered silicate plates, and the term "uniformly dispersed" means that the layered silicate plates have an average of five or less stacked layers in parallel or randomly. Alternatively, it refers to a state in which 50% by weight or more, preferably 70% by weight or more, are dispersed without forming a local lump in a state of being randomly and parallelly mixed.

The proportion of the layered silicate is from 0.05 to 10 parts by weight, especially from 1.100 parts by weight of the polyamide resin.
5 to 5 parts by weight are preferred. The ratio of layered silicate is 0.05
If the amount is less than 10 parts by weight, the effect of suppressing fuel permeation is not sufficient.

When the layered silicate is a multilayered clay mineral, an amine such as dioctadecylamine, phenylenediamine, an amino acid such as 4-amino-n-butyric acid, 12-aminododecanoic acid or ε-caprolactam may be used. After contacting with such a swelling agent for lactams to expand the layers in advance to make it easier to take in monomers between the layers, it is also possible to polymerize and uniformly disperse the monomers. Also, using a swelling agent,
A method may be used in which the interlayer is expanded to 20 ° or more in advance, and this is melt-mixed with the polyamide resin and uniformly dispersed.

Further, the polyamide resin composition of the present invention comprises:
Although it can be used as a fuel component as it is, heat-resistant agents, weathering agents, crystal nucleating agents, crystallization accelerators, mold release agents, lubricants, antistatic agents, flame retardants, flame retardant aids, as long as the purpose is not impaired,
A function imparting agent such as a coloring agent can be used.

More specifically, hindered phenols, phosphites, thioethers,
Copper halide and the like can be mentioned, and these can be used alone or in combination. Examples of the weathering agent include hindered amines and salicylates, which can be used alone or in combination. As a crystal nucleating agent, talc,
Examples include inorganic fillers such as clay and organic crystal nucleating agents such as fatty acid metal salts, and these can be used alone or in combination. Examples of the crystallization promoter include low molecular weight polyamides, higher fatty acids, higher fatty acid esters and higher fatty alcohols, and these can be used alone or in combination. Release agents include fatty acid metal salts,
Examples thereof include fatty acid amides and various waxes, which can be used alone or in combination. Examples of the antistatic agent include aliphatic alcohols, aliphatic alcohol esters and higher fatty acid esters, and these can be used alone or in combination. Flame retardants include metal hydroxides such as magnesium hydroxide, phosphorus, ammonium phosphate, ammonium polyphosphate, melamine cyanurate,
Ethylene dimelamine dicyanurate, potassium nitrate, brominated epoxy compound, brominated polycarbonate compound,
Brominated polystyrene compounds, tetrabromobenzyl polyacrylate, polycondensates of tribromophenol, polybromobiphenyl ethers and chlorine-based flame retardants,
They can be used alone or in combination. Among these, it is preferable to add a moldability improving agent such as a release agent, a lubricant, and a crystal nucleating agent.

Other thermoplastic resins can be added to the polyamide resin composition of the present invention as long as the object of the present invention is not impaired. Examples of the thermoplastic resin used in combination include general-purpose resin materials such as polyethylene, polypropylene, polystyrene, ABS resin, AS resin, and acrylic resin, polycarbonate, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, and other high heat resistant resins. Can be In particular, when polyethylene or polypropylene is used in combination, it is desirable to use those modified with maleic anhydride, a glycidyl group-containing monomer, or the like.

A fuel component using the polyamide resin composition of the present invention is joined to a fuel tank using a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof as an intermediate adhesive layer. Specifically, first, a polyamide resin composition and a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof are welded, and then the attached parts are joined to a fuel tank.

Polyolefin resins modified with unsaturated carboxylic acids or derivatives thereof include polyethylene,
Ethylene / α-olefin copolymer, ethylene / α, β
-Unsaturated carboxylic acid ester copolymers, ethylene-vinyl acetate partially saponified copolymers, and polymers obtained by graft-polymerizing an unsaturated carboxylic acid or a derivative thereof to the above copolymer.

The ethylene / α-olefin copolymer is a polymer obtained by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms. Examples of the α-olefin having 3 or more carbon atoms include propylene and butene-1. Hexene-1, decene-1, 4-methylbutene-1, 4-methylpentene-1
And preferably propylene and butene-1.

The ethylene / α, β-unsaturated carboxylic acid ester-based copolymer is a polymer obtained by copolymerizing ethylene with an α, β-unsaturated carboxylic acid ester monomer.
As unsaturated carboxylic acid ester monomers, methyl acrylate, ethyl acrylate, propyl acrylate, acrylate such as butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Examples thereof include methacrylates such as butyl methacrylate. Preferably, an ethylene / ethyl acrylate copolymer or an ethylene / methyl methacrylate copolymer which is available at a low cost and has excellent thermal stability is exemplified.

The ethylene / vinyl acetate partially saponified copolymer is a compound obtained by partially saponifying an ethylene / vinyl acetate copolymer. The ethylene-vinyl acetate copolymer is saponified by a known saponification method, for example, a method of treating with a system comprising a low-boiling alcohol such as methanol and ethanol and an alkali such as sodium hydroxide, potassium hydroxide and sodium methylate. Thus, a partially saponified ethylene / vinyl acetate copolymer can be obtained.

As the unsaturated carboxylic acid or its derivative to be graft-polymerized, acrylic acid, methacrylic acid,
Ethacrylic acid, maleic acid, fumaric acid, itaconic acid,
Citraconic acid, unsaturated carboxylic acids such as nadic acid or derivatives thereof, for example, acid halides, amides, imides,
Examples thereof include anhydrides and esters. Specific examples of the derivative include maleenyl chloride, maleimide, maleic anhydride,
Monomethyl maleate, dimethyl maleate and the like can be mentioned. Among these, unsaturated dicarboxylic acids or anhydrides thereof are preferable, and maleic acid, nadic acid or acid anhydrides thereof are particularly preferably used. Also,
Modified polyolefin resin is a known production method, for example,
A method of reacting an unmodified polyolefin resin with an unsaturated carboxylic acid in a molten state, a method of reacting in a solution state,
It can be produced by any of a method of reacting in a slurry state, a method of reacting in a gas phase state, and the like.

The method of welding the polyamide resin composition of the present invention to a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof is performed by first molding a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, This is performed by injection molding a polyamide resin composition and welding both molded products.

Specific examples of the welding method include a vibration welding method, an injection welding method such as die slide injection (DSI), die rotary injection (DRI) and two-color molding, an ultrasonic welding method, a spin welding method, and a hot plate welding method. , Hot-wire welding, laser welding, high-frequency induction heating welding, and the like.

The molding resin temperature at the time of welding by an injection welding method such as DSI, DRI or two-color molding is desirably 250 to 320 ° C., preferably 270 to 300 ° C. The mold temperature at that time is 30 ° C to 120 ° C, preferably 50 ° C to 100 ° C.
Is desirable.

Examples of fuel parts using the polyamide resin composition of the present invention include parts such as a fuel tank, valves attached to the fuel tank, a fuel hose joint, a canister connecting nozzle, and a separator.

[0038]

The present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The measurement of the physical properties of the molded articles in Examples and Comparative Examples was performed as follows.

[Measurement of Terminal Group Concentration of Polyamide Resin] The amino terminal group concentration was measured by dissolving 1 g of polyamide in a phenol / methanol mixed solution and titrating with 0.02N hydrochloric acid. Carboxyl end group concentration is 1 g of polyamide
Was dissolved in benzyl alcohol and titrated with a 0.05N sodium hydroxide solution for measurement.

[Fuel Permeability Coefficient] According to JIS Z0208, a fuel permeation test was conducted at a measurement atmosphere temperature of 60 ° C. using a test piece having a diameter of 75 mm and a thickness of 1 mm formed by injection molding. The fuel is isooctane and toluene in a volume ratio of 1:
10% of ethanol was used for FuelC which was set to 1. Further, the fuel permeation measurement sample surface was installed with the permeation surface facing downward so that the fuel was always in contact.

[Tensile strength] According to ASTM D638,
Using a 3.2 mm thick No. 1 test piece, pulling speed 5 min / min
mm.

[Initial Adhesive Strength] With the shape of the test piece shown in FIG. 1, the boundary surface between the part 1 and the part 2 is melt-bonded at the time of injection welding to obtain one test piece. In the test piece, first, a metal piece having the shape of the part 2 in FIG. 1 was inserted into a mold, and the part 1 was molded using polyethylene modified with maleic anhydride. Next, after the component 1 is sufficiently cooled, it is inserted into a mold,
The joined test piece was obtained by molding the part 2 using the resin to be evaluated. The maximum tensile strength until the test piece was peeled off from the boundary surface at a pulling speed of 50 mm / min or was broken at a portion other than the boundary surface (substrate failure) was measured, and evaluated as the initial adhesive strength.

[Adhesive strength after fuel immersion] A test piece molded in the same procedure as in the evaluation of the initial adhesive strength is placed in an autoclave, and FuelC + methanol 15% mixed fuel is sealed until the test piece is completely immersed. 6
It was left in a hot water bath at 0 ° C. for 350 hours. Thereafter, the maximum tensile strength of the test piece taken out was evaluated as the adhesive strength after fuel immersion.

Example 1 100 g of montmorillonite having an average thickness of one unit of the layered silicate of 9.5 ° and an average length of one side of about 0.1 μm was dispersed in 10 L of water, and 51.2 g of 12 -Aminododecanoic acid and 24 mL of concentrated hydrochloric acid were added, and the mixture was diffused for 5 minutes and filtered. Further, this was sufficiently washed and dried under vacuum.
By this operation, a complex of ammonium 12-aminododecanoate ion and montmorillonite was prepared. The layered silicate content in the composite was 80% by weight. In the measurement of the composite by X-ray diffraction, the silicate interlayer distance was 18.0.
Was Å. In a 70 liter autoclave, 20 kg of ε-caprolactam and 0.5 k of water were used as polymerization monomers.
g and 200 g of the complex and meta-xylylenediamine were charged so as to have a concentration of 1/290 (eq / mol lactam), and the inside of the tank was replaced with nitrogen. Next, the inside of the tank was 260 ° C,
The mixture was stirred at 1.7 MPa for 1 hour. Thereafter, the pressure was released, and polymerization was carried out at normal pressure for 3 hours while evaporating water from the reaction vessel. After the completion of the reaction, the polymer taken out in a strand form from the lower nozzle of the reaction vessel was cooled and cut to obtain a pellet comprising a polyamide resin and montmorillonite.
The unreacted monomer was extracted from the obtained pellets in hot water at 100 ° C., and dried under vacuum to obtain a sample. When the interlayer distance of this material was measured by X-ray diffraction, it was 100 ° or more. The resulting polyamide 6 had a relative viscosity of 2.50 and an amino terminal group concentration of 90 meq / kg. The obtained pellets were heated at a cylinder temperature of 270 ° C and a mold temperature of 80 ° C.
, And a tensile test specimen conforming to ASTM was evaluated. In addition, the initial adhesive strength and the adhesive strength after fuel immersion of a test piece molded at a secondary injection molding cylinder set temperature of 270 ° C. and a mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Furthermore, using a 1 mm thick plate molded under the same molding conditions,
A fuel permeation test based on JIS Z0208 was performed.
The results obtained are shown in Table 1.

Example 2 In Example 1, meta-xylylenediamine was replaced with 1/350
(Eq / mol lactam), except that polyamide 6 was obtained in the same manner as in Example 1. The amino terminal group concentration of the obtained polyamide 6 was 60 meq. The obtained pellet was injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen in accordance with ASTM was evaluated. Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Furthermore, using a 1 mm thick plate molded under the same molding conditions, JIS
A fuel permeation test based on Z0208 was performed. The results obtained are shown in Table 1.

Example 3 In Example 1, meta-xylylenediamine was used in an amount of 1/200
(Eq / mol lactam), except that polyamide 6 was obtained in the same manner as in Example 1. The resulting polyamide 6 had an amino terminal group concentration of 110 meq. The obtained pellets were injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen based on ASTM was evaluated. Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Furthermore, using a 1 mm thick plate molded under the same molding conditions, JIS
A fuel permeation test based on Z0208 was performed. The results obtained are shown in Table 1.

Example 4 The same procedure as in Example 1 was repeated except that the montmorillonite composite
Polyamide 6 was obtained in the same manner as in Example 1 except that g was used. When the interlayer distance of the obtained material was measured by X-ray diffraction, it was 100 ° or more. The obtained pellets are injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C.
ASTM compliant tensile test pieces were evaluated. In addition, the secondary injection molding cylinder set temperature during the procedure of FIG.
The initial adhesive strength of the test piece molded at a mold temperature of 80 ° C. and the adhesive strength after fuel immersion were measured. Further, a plate having a thickness of 1 mm molded under the same molding conditions was used, and JIS Z020 was used.
A fuel permeation test according to No. 8 was conducted. The results obtained are shown in Table 1.

Example 5 In a 70-liter autoclave, ω-
20 kg of laurololactam, 4 kg of water, 200 g of the montmorillonite complex and meta-xylylenediamine were charged to 1/300 (eq / mol lactam), and the inside of the tank was replaced with nitrogen. Was stirred so as to be uniform. Next, at 280 ° C
After pre-polymerization at 3.0 MPa, the temperature was lowered to 250 ° C. while releasing the pressure to atmospheric pressure, and post-polymerization was performed at 250 ° C. under a nitrogen stream. After completion of the reaction, the polymer taken out in a strand form from the lower nozzle of the reaction vessel was cooled and cut to obtain a pellet composed of a polyamide resin and montmorillonite. The unreacted monomers were extracted from the obtained pellets in hot water at 100 ° C. and dried under vacuum to obtain a sample. The interlayer distance of this material was measured by X-ray diffraction.
0 ° or more. The obtained polyamide 12 had a relative viscosity of 2.05 and an amino terminal group concentration of 60 meq / kg. The obtained pellets were heated at a cylinder temperature of 270 ° C.
Injection molding was performed at a mold temperature of 80 ° C., and a tensile test specimen in accordance with ASTM was evaluated. In addition, the initial adhesive strength and the adhesive strength after fuel immersion of a test piece molded at a secondary injection molding cylinder set temperature of 270 ° C. and a mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Further, a fuel permeation test based on JIS Z0208 was performed using a plate having a thickness of 1 mm molded under the same molding conditions. The results obtained are shown in Table 1.

Example 6 In Example 5, meta-xylylenediamine was replaced with 1/480
(Eq / mol lactam), except that polyamide 12 was obtained in the same manner as in Example 5. Polyamide 12 obtained
Had an amino end group concentration of 50 meq. The obtained pellets were injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen based on ASTM was evaluated.
Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Using a 1 mm thick plate molded under the same molding conditions,
A fuel permeation test based on SZ0208 was performed. The results obtained are shown in Table 1.

Example 7 In Example 5, meta-xylylenediamine was added at 1/250
(Eq / mol lactam), except that polyamide 12 was obtained in the same manner as in Example 5. Polyamide 12 obtained
Had an amino end group concentration of 80 meq. The obtained pellets were injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen based on ASTM was evaluated.
Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Using a 1 mm thick plate molded under the same molding conditions,
A fuel permeation test based on SZ0208 was performed. The results obtained are shown in Table 1.

Comparative Example 1 In Example 1, meta-xylylenediamine was replaced with 1/400
(Eq / mol lactam), except that polyamide 6 was obtained in the same manner as in Example 1. The amino terminal group concentration of the obtained polyamide 6 was 50 meq. The obtained pellets were injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen based on ASTM was evaluated. Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Furthermore, using a 1 mm thick plate molded under the same molding conditions, JIS
A fuel permeation test based on Z0208 was performed. The results obtained are shown in Table 1.

Comparative Example 2 A polyamide 6 was obtained in the same manner as in Example 1 except that the polymerization was carried out without adding the montmorillonite composite. The obtained pellets were injection molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a tensile test specimen based on ASTM was evaluated. Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Further, a fuel permeation test based on JIS Z0208 was performed using a plate having a thickness of 1 mm molded under the same molding conditions. The results obtained are shown in Table 1.

Comparative Example 3 Polyamide 12 was prepared in the same manner as in Example 5 except that the polymerization was carried out without adding the montmorillonite composite.
I got The obtained pellets were heated at a cylinder temperature of 270 ° C.
Injection molding was performed at a mold temperature of 80 ° C., and a tensile test specimen in accordance with ASTM was evaluated. Further, the initial adhesive strength and the adhesive strength after fuel immersion of the test piece molded at the secondary injection molding cylinder set temperature of 270 ° C. and the mold temperature of 80 ° C. in the procedure of FIG. 1 were measured. Further, a fuel permeation test based on JIS Z0208 was performed using a plate having a thickness of 1 mm molded under the same molding conditions. The results obtained are shown in Table 1.

Comparative Example 4 Polyethylene modified with maleic anhydride was injection molded at a cylinder temperature of 190 ° C. and a mold temperature of 40 ° C.
M-compliant tensile test pieces were evaluated. In addition, using a plate having a thickness of 1 mm molded under the same molding conditions,
08 was conducted. The results obtained are shown in Table 1.

[0055]

[Table 1]

[0056]

The polyamide resin composition of the present invention has high welding strength and barrier properties without impairing the intrinsic properties of the crystalline polyamide resin. For this reason, it can be used for a large molded product or a component having a complicated shape without depending on a special molding machine or a post-processing method. Further, the fuel component using the polyamide resin composition of the present invention has excellent fuel permeation resistance and excellent fuel resistance of the welded part, particularly excellent fuel resistance of the welded part over a long period of time. It can be suitably used as various parts attached to.

[Brief description of the drawings]

FIG. 1 is a diagram showing the shape of a test piece for evaluating adhesive strength.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA54 AA55 AA56 AB26 AB30 AD05 AF04 AH05 AH07 BB05 BC04 4J002 CL001 CL011 CL031 CL051 DJ006 DJ036 DJ056 FA016 FD016 FD03 FD06 FD07 FD10 FD13 FD16 FD20 GG01 GN

Claims (8)

[Claims] (1) 100 parts by weight of a crystalline polyamide resin in which (A) amino terminal group concentration> carboxyl terminal group concentration; and (B) 0.05 to 10 parts by weight of a layered silicate uniformly dispersed in the polyamide resin. And a polyamide resin composition having excellent fuel resistance at the welded portion. 2. The polyamide resin composition according to claim 1, wherein the amino terminal group concentration is at least 50 meq / kg of the polymer. 3. The polyamide resin composition according to claim 1, wherein the crystalline polyamide resin is an aliphatic diamine and an aliphatic dicarboxylic acid, or an aliphatic polyamide resin comprising a lactam or an aminocarboxylic acid. 4. The polyamide resin composition according to claim 1, wherein the crystalline polyamide resin is a crystalline semi-aromatic polyamide resin containing at least one aromatic monomer component. 5. The layered silicate having a side length of 0.002
１1 μm and 6-20 mm thick, each having an average of 2
The polyamide resin composition according to claim 1, wherein the polyamide resin composition is uniformly dispersed in the polyamide resin while maintaining an interlayer distance of 0 ° or more. 6. (A) 100 parts by weight of a crystalline polyamide resin having an amino terminal group concentration> carboxyl terminal group concentration, and (B) 0.05 to 10 parts by weight of a layered silicate uniformly dispersed in the polyamide resin. A fuel part using a polyamide resin composition consisting of parts and having excellent fuel resistance at the welded part. 7. A fuel part comprising a polyamide resin composition according to claim 1 and a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, which are welded and have excellent fuel resistance. 8. The method according to claim 1, wherein a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof is molded.
A method for producing a fuel component having excellent fuel resistance at a welded portion, comprising injection-molding the polyamide resin composition described above and welding both molded products.