JP2007031723A - Polyamide resin composition having excellent fuel resistance at welded part and fuel part using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition that can be used for producing a large-size molded product or a part having a complicated shape, with no damage to the intrinsic property of crystalline polyamide resin and maintain high welding property in no need of special molding machine or after processing and provide fuel parts by using the polyamide resin composition that has excellent fuel resistance at the welded parts, particularly having excellent fuel permeation resistance for a long period of time. <P>SOLUTION: The polyamide resin composition having excellent fuel resistance at the welded parts comprises (A) 100 pts.wt. of crystalline polyamide resin of (the amino terminal groups concentration) > (the carboxy terminal groups concentration) and (B) 0.05 to 10 pts.wt. of a silicate salt layer that is homogeneously dispersed in the polyamide resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyamide resin composition excellent in 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 of a welded portion over a long period of time, and a fuel component using the same.

Conventionally, for the purpose of safety and environmental measures, it has been required to reduce the volatilization amount of fuel from the wall of the fuel tank or the accessory parts such as accessory parts. For example, in the automobile field, a resin fuel tank of high-density polyethylene (sometimes referred to as HDPE resin) manufactured by a single-layer structure blow method is widely used as a fuel tank body of an automobile. In the case of a fuel tank, a method of sulfonating the resin (SO ₃ treatment, Japanese Patent Publication No. Sho 46-23914), a method of fluorine treatment (F ₂ treatment), and a barrier resin to reduce the amount of fuel permeated from the tank body And a method of making a hollow molded product having a multilayer structure (Japanese Patent Publication No. Sho 55-49989), a method of dispersing a barrier resin such as polyamide in a continuous matrix phase of polyethylene in a flake form (Japanese Patent Publication No. Sho 60-14695) ) Etc. have been developed.

  In particular, recently, an outer layer made of HDPE resin is formed on the outer side of the fuel tank, and a polyamide resin or an ethylene vinyl alcohol copolymer inner layer having an excellent fuel gas barrier property is formed on the inner side of the fuel tank. Fuel tanks are becoming common.

  However, even if the permeation amount of fuel from the fuel tank body is reduced by the above method, the permeation amount from various parts (for example, valves) attached to the fuel tank is actually large, and the whole fuel parts It is an obstacle to reduce the amount of volatilization from

  This is because various parts attached to the fuel tank are made of high-density polyethylene, which is the same material as the fuel tank, in order to obtain sufficient adhesion strength with the fuel tank. It is because it is inferior.

  Therefore, it has been studied to manufacture various parts attached to the fuel tank with a polyamide resin having excellent fuel permeability. However, since polyethylene and polyamide are originally poorly bonded, this time, the fuel tank is sufficiently There was a problem that the adhesive strength could not be obtained.

  An object of the present invention is to solve the above-mentioned problems, and to use a polyamide resin composition having excellent fuel permeation resistance and fuel resistance of a welded portion, particularly excellent in fuel resistance of a welded portion over a long period of time. To provide fuel parts.

  As a result of intensive studies to solve this problem, the present inventors have found that (A) 100 parts by weight of a crystalline polyamide resin in which the amino terminal group concentration is higher than the carboxyl terminal group concentration, and (B) is uniformly dispersed in the polyamide resin. It has been found that the object can be achieved by using a polyamide resin composition comprising 0.05 to 10 parts by weight of layered silicate, and the present invention has been achieved.

  That is, the present invention includes (A) 100 parts by weight of a crystalline polyamide resin in which amino end group concentration> carboxyl end group concentration and (B) layered silicate 0.05 to 10 uniformly dispersed in the polyamide resin. The present invention relates to a polyamide resin composition consisting of parts by weight and excellent in fuel resistance of a welded part.

  In addition, the present invention provides (A) 100 parts by weight of a crystalline polyamide resin in which the amino end group concentration> the carboxyl end group concentration, and (B) a layered silicate 0.05 to 10 uniformly dispersed in the polyamide resin. The present invention relates to a fuel component using a polyamide resin composition composed of parts by weight and having excellent fuel resistance in a welded part.

  The polyamide resin composition of the present invention has high welding strength and barrier properties without impairing the original characteristics of the crystalline polyamide resin. For this reason, it can be used for a large-sized molded product or a component having a complicated shape without depending on a special molding machine or a post-processing method.

  Further, the fuel part using the polyamide resin composition of the present invention has excellent fuel permeation resistance and fuel resistance of the welded portion, particularly excellent fuel resistance of the welded portion over a long period of time. It can be suitably used as various parts attached to.

  The present invention is described in detail below.

  The crystalline polyamide resin of the present invention has an amino end group concentration higher than a carboxyl end group concentration. Further, the amino end group concentration is desirably 50 milliequivalents or more, preferably 60 milliequivalents or more per kg of the polymer. When the amino terminal group concentration is excessive, when it is welded with a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, the welding strength is excellent, and excellent fuel resistance is exhibited.

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

  As a monomer component of the aliphatic polyamide resin, an aliphatic diamine having 4 to 12 carbon atoms and an aliphatic dicarboxylic acid having 6 to 12 carbon atoms, or a lactam having 6 to 12 carbon atoms or an aminocarboxylic acid having 6 to 12 carbon atoms. Is mentioned.

  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. , Heptane dicarboxylic acid, octane dicarboxylic acid, nonane dicarboxylic acid, undecane dicarboxylic acid, dodecane dicarboxylic acid, etc., and a preferred combination of aliphatic diamine and aliphatic dicarboxylic acid is an equimolar salt of hexamethylene diamine and adipic acid. .

  Specific examples of the lactam include α-pyrrolidone, ε-caprolactam, ω-laurolactam, ε-enantolactam, and the like. Specific examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 11 -Aminoundecanoic acid, 12-aminododecanoic acid and the like can be mentioned, and 6-aminocaproic acid, 12-aminododecanoic acid, ε-caprolactam and laurolactam are preferable.

  The aliphatic polyamide-forming monomer can be used not only as a single component but also 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 two or more types of copolymers.

  The crystalline polyamide resin of the present invention is preferably a crystalline semi-aromatic polyamide resin containing one or more aromatic monomer components.

  As a crystalline semi-aromatic polyamide resin containing one or more aromatic monomer components, a copolymer containing one or more aromatic monomer components such as aromatic dicarboxylic acid components such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid A polyamide resin is mentioned. Preferably, it is a crystalline semi-aromatic copolymer polyamide resin containing one or more aromatic monomer components and having a melting point of 260 ° C. or higher and lower than 320 ° C., more preferably, containing one or more aromatic monomer components, A crystalline semi-aromatic copolymer polyamide resin having a melting point of 290 ° C. or higher and lower than 316 ° C.

  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.

  Here, the aliphatic diamine is an aliphatic diamine having 4 to 12 carbon atoms, and examples thereof include tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethyle diamine, undecamethylene diamine, and dodecamethylene diamine.

  The aliphatic dicarboxylic acid is an aliphatic dicarboxylic acid having 6 to 12 carbon atoms, and examples thereof include adipic acid, heptanedicarboxylic acid, octanedicarboxylic acid, nonanedicarboxylic acid, undecanedicarboxylic acid, and dodecanedicarboxylic acid.

  A preferred combination is an equimolar salt of hexamethylenediamine and adipic acid.

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

  Aliphatic monomers include aminocarboxylic acids having 6 to 12 carbon atoms 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-enantolactam, and the like, and 6-aminocaproic acid, 12-aminododecanoic acid, ε-caprolactam, and laurolactam are preferable. The aliphatic polyamide-forming monomer can be used not only as a single component but also 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, it is 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.

  The degree of polymerization of the crystalline polyamide resin in the present invention is not particularly limited, but it is preferable that 1 g of a 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. More preferably, it is 2.0-3.0. When the relative viscosity is higher than the upper limit of the above numerical value, the workability is remarkably impaired. When the relative viscosity is lower than the lower limit, the mechanical strength is lowered, which is not preferable.

  The method for producing a polyamide resin in which the amino end group concentration of the present invention is larger than the carboxyl end group concentration is not particularly limited, but when the composition is extruded or kneaded at the time of polymerization or after completion of polymerization, a diamine compound is added. It can be obtained by containing. If manufactured at the time of melt polymerization, a method of polymerizing by adding an excessive amount of diamine monomer at the time of raw material charging, a method of polymerizing by adding a raw material monomer and a diamine compound other than the raw material monomer at the time of raw material charging, polymerizing polyamide of a predetermined molecular weight Then, a method of adding a diamine compound so as to achieve a target end group concentration balance immediately before extracting the polymer from the polymerization tank is used. If it is produced after the polymerization, a method of melt-kneading the polyamide resin after polymerization and the diamine compound so as to achieve the target end group concentration balance is used.

  Specific examples of this diamine compound include aliphatic diamines such as methylene diamine, ethylene diamine and trimethylene diamine, and aromatic diamines such as naphthalene diamine and metaxylylene diamine in addition to those used as the above-mentioned polyamide resin monomers. Preferably, hexamethylenediamine, dodecamethylenediamine, or metaxylylenediamine is used.

  In the polyamide resin composition of the present invention, the layered silicate is uniformly dispersed in the polyamide resin. Examples of layered silicates include layered phyllosilicates composed of magnesium silicate or aluminum silicate layers.

  Specific examples of the layered phyllosilicate include smectite clay minerals such as montmorillonite, saponite, piderite, nontronite, hectorite, and stippsite, vermiculite, and halosite. These may be natural products or synthetic products. Among these, montmorillonite is preferable.

  The layered silicate is preferably uniformly dispersed in the polyamide resin. The state in which the layered silicate is uniformly dispersed means that when a layered silicate having a side length of 0.002 to 1 μm and a thickness of 6 to 20 mm is dispersed in the polyamide resin, each average 20 mm or more. The distance between the layers is kept uniformly distributed. Here, the interlayer distance means the distance between the center of gravity of the layered silicate flat plate, and uniformly dispersed means that the multilayered layered silicate flat plate is averagely 5 layers or less in parallel or randomly, Alternatively, in a state of being mixed in parallel and randomly, 50% by weight or more, preferably 70% by weight or more is dispersed without forming a local lump.

  The proportion of the layered silicate is preferably 0.05 to 10 parts by weight, particularly 1.5 to 5 parts by weight with respect to 100 parts by weight of the polyamide resin. When the ratio of the layered silicate is less than 0.05 parts by weight, the effect of suppressing fuel permeation is not sufficient, and when it exceeds 10 parts by weight, the physical properties of the polymer, particularly the impact strength, is lowered, which is not preferable.

  When the layered silicate is a multilayer clay mineral, an amine such as dioctadecylamine, phenylenediamine, an amino acid such as 4-amino-n-butyric acid, 12-aminododecanoic acid, or a lactam such as ε-caprolactam It is also possible to spread the layers in advance by bringing them into contact with a kind of swelling agent to facilitate incorporation of the monomers between the layers, and then polymerize and uniformly disperse them. Further, a method may be used in which a swelling agent is used and the interlayer is expanded to 20 mm or more in advance, and this is melt-mixed with the polyamide resin and uniformly dispersed.

  In addition, the polyamide resin composition of the present invention can be used as a fuel part as it is, but as long as its purpose is not impaired, a heat resisting agent, weathering agent, crystal nucleating agent, crystallization accelerator, mold release agent, lubricant, antistatic Functionality-imparting agents such as agents, flame retardants, flame retardant aids, and colorants can be used.

  More specifically, examples of the heat-resistant agent include hindered phenols, phosphites, thioethers, copper halides and the like, and these can be used alone or in combination.

  Examples of the weathering agent include hindered amines and salicylates, and these can be used alone or in combination.

  Examples of the crystal nucleating agent include inorganic fillers such as talc and clay, and organic crystal nucleating agents such as fatty acid metal salts, which can be used alone or in combination.

  Examples of the crystallization accelerator include low molecular weight polyamides, higher fatty acids, higher fatty acid esters and higher aliphatic alcohols, which can be used alone or in combination.

  Examples of the mold release agent include fatty acid metal salts, 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, which 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 compounds, brominated polycarbonate compounds, brominated Examples thereof include polystyrene compounds, tetrabromobenzyl polyacrylate, tribromophenol polycondensates, polybromobiphenyl ethers and chlorine-based flame retardants, and these can be used alone or in combination.

  Among these, it is preferable to add moldability improvers such as mold release agents, lubricants, and crystal nucleating agents.

  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 thermoplastic resins 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. It is done. In particular, when polyethylene or polypropylene is used in combination, it is desirable to use one modified with maleic anhydride or a glycidyl group-containing monomer.

  A fuel part 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 this accessory part is joined to a fuel tank.

  Polyolefin resins modified with unsaturated carboxylic acids or their derivatives include polyethylene, ethylene / α-olefin copolymers, ethylene / α, β-unsaturated carboxylic acid ester copolymers, ethylene / vinyl acetate partial saponification. Examples thereof include a polymer obtained by graft-polymerizing an unsaturated carboxylic acid or a derivative thereof to the above copolymer to a physical 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, butene-1, hexene- 1, decene-1, 4-methylbutene-1, 4-methylpentene-1 are mentioned, Preferably propylene and butene-1 are mentioned.

  The ethylene / α, β-unsaturated carboxylic acid ester copolymer is a polymer obtained by copolymerizing ethylene and an α, β-unsaturated carboxylic acid ester monomer, and is an α, β-unsaturated carboxylic acid ester. Examples of monomers include acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and methacrylate esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. be able to. Preferably, an ethylene / ethyl acrylate copolymer or an ethylene / methyl methacrylate copolymer which can be obtained at low cost and has excellent thermal stability can be used.

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

  Examples of unsaturated carboxylic acids or derivatives thereof to be graft-polymerized include unsaturated carboxylic acids or derivatives thereof such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, nadic acid, such as acid halides, Amides, imides, anhydrides, esters and the like can be mentioned. Specific examples of the derivative include maleenyl chloride, maleimide, maleic anhydride, monomethyl maleate, dimethyl maleate and the like. Of these, unsaturated dicarboxylic acids or their anhydrides are preferred, and maleic acid, nadic acid or their acid anhydrides are particularly preferred.

  The modified polyolefin resin is a known production method, for example, a method of reacting an unsaturated carboxylic acid with an unmodified polyolefin resin in a molten state, a method of reacting in a solution state, a method of reacting in a slurry state, or a gas phase state. It can be produced by any of the methods of reacting.

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

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

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

  Examples of the 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 joint for a fuel hose, a nozzle for connecting a canister, a separator, and the like.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

  In addition, the physical-property measurement of the molded article in an Example and a comparative example was performed as follows.

[Measurement of end group concentration of polyamide resin]
The amino end group concentration was measured by dissolving 1 g of polyamide in a phenol / methanol mixed solution and titrating with 0.02N hydrochloric acid.

  The carboxyl end group concentration was measured by dissolving 1 g of polyamide in benzyl alcohol and titrating with 0.05 N sodium hydroxide solution.

[Fuel permeability coefficient]
In accordance with JIS Z0208, a fuel permeation 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.

[Tensile strength]
According to ASTM D638, a No. 1 test piece having a thickness of 3.2 mm was used and the tensile speed was 5 mm per minute.

[Initial bond strength]
In the shape of the test piece shown in FIG. 1, the interface between the part 1 and the part 2 is melted and bonded at the time of injection welding, whereby one test piece is obtained.

  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 was sufficiently cooled, it was inserted into a mold, and a part of the component 2 was molded using a resin to be evaluated, thereby obtaining a bonded test piece. The maximum tensile strength until the test piece was peeled off from the boundary surface at a tensile speed of 50 mm / min or destroyed at a portion other than the boundary surface (base material failure) was measured and evaluated as the initial adhesive strength.

[Adhesive strength after immersion in fuel]
A test piece molded in the same procedure as the evaluation of the initial adhesive strength is put in an autoclave, and Fuel C + methanol 15% mixed fuel is sealed until the test piece is completely immersed. The autoclave was left in a 60 ° C. hot water tank for 350 hours. Thereafter, the maximum tensile strength point of the test piece taken out was evaluated as the adhesion strength after fuel immersion.

Example 1
100 g of montmorillonite having an average thickness of one unit of layered silicate of 9.5 mm and an average length of one side of about 0.1 μm is dispersed in 10 L of water, to which 51.2 g of 12-aminododecanoic acid and 24 mL are dispersed. Of concentrated hydrochloric acid was added, diffused for 5 minutes, and then filtered. Further, this was sufficiently washed and vacuum-dried. By this operation, a complex of 12 aminododecanoate ammonium ion and montmorillonite was prepared. The layered silicate content in the composite was 80% by weight. Further, the X-ray diffraction measurement of this composite showed a silicate interlayer distance of 18.0 mm.

  A 70 liter autoclave was charged with 0.5 kg of water and 200 g of the complex and metaxylylenediamine as a polymerization monomer to 20 kg of ε-caprolactam to 1/290 (eq / mol lactam), and the inside of the tank was replaced with nitrogen. Then, it heated to 100 degreeC and stirred so that the inside of a tank might become uniform. Next, the inside of the tank was stirred at 260 ° C. and 1.7 MPa for 1 hour. Thereafter, the pressure was released, and polymerization was performed for 3 hours under normal pressure while volatilizing water from the reaction vessel. 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 pellets made of polyamide resin and montmorillonite. Unreacted monomers were extracted from the obtained pellets in 100 ° C. hot water and vacuum dried to prepare a sample. The interlayer distance of this material measured by X-ray diffraction was 100 mm or more.

  The obtained polyamide 6 had a relative viscosity of 2.50 and an amino end group concentration of 90 meq / kg. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 2
A polyamide 6 was obtained in the same manner as in Example 1 except that metaxylylenediamine was changed to 1/350 (eq / mol lactam) in Example 1. The resulting polyamide 6 had an amino end group concentration of 60 milliequivalents. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 3
Polyamide 6 was obtained in the same manner as in Example 1 except that metaxylylenediamine was changed to 1/200 (eq / mol lactam) in Example 1. The amino end group concentration of the obtained polyamide 6 was 110 milliequivalents. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 4
A polyamide 6 was obtained in the same manner as in Example 1 except that 500 g of the montmorillonite composite was used in Example 1. When the interlayer distance of the obtained material was measured by X-ray diffraction, it was 100 mm or more. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 5
A 70 liter autoclave was charged with 4 kg of water and 200 g of the montmorillonite complex and metaxylylenediamine as 1/300 (eq / mol lactam) with respect to 20 kg of ω-laurolactam as a polymerization monomer, and the inside of the tank was replaced with nitrogen. Then, it heated to 180 degreeC and stirred so that the inside of a tank might become uniform. Next, after prepolymerization was performed at 280 ° C. and 3.0 MPa in the tank, the temperature was lowered to 250 ° C. while releasing the pressure to atmospheric pressure, and post-polymerization was performed at 250 ° C. in 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 pellets made of polyamide resin and montmorillonite. Unreacted monomers were extracted from the obtained pellets in 100 ° C. hot water and vacuum dried to prepare a sample. The interlayer distance of this material measured by X-ray diffraction was 100 mm or more.

  The obtained polyamide 12 had a relative viscosity of 2.05 and an amino end group concentration of 60 meq / kg. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 6
Polyamide 12 was obtained in the same manner as in Example 5 except that metaxylylenediamine was changed to 1/480 (eq / mol lactam) in Example 5. The resulting polyamide 12 had an amino end group concentration of 50 milliequivalents. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Example 7
Polyamide 12 was obtained in the same manner as in Example 5 except that metaxylylenediamine was changed to 1/250 (eq / mol lactam) in Example 5. The amino terminal group concentration of the obtained polyamide 12 was 80 milliequivalents. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Comparative Example 1
Polyamide 6 was obtained in the same manner as in Example 1 except that metaxylylenediamine was changed to 1/400 (eq / mol lactam) in Example 1. The resulting polyamide 6 had an amino end group concentration of 50 milliequivalents. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Comparative Example 2
A polyamide 6 was obtained in the same manner as in Example 1 except that polymerization was performed without adding the montmorillonite complex in Example 1. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results are shown in Table 1.

Comparative Example 3
A polyamide 12 was obtained in the same manner as in Example 5 except that polymerization was performed without adding the montmorillonite complex in Example 5. The obtained pellet was injection-molded at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and an ASTM-compliant tensile test piece was evaluated. Further, the initial adhesion strength and the adhesion 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 1 mm thick plate molded under the same molding conditions. The obtained results 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., and an ASTM-compliant tensile test piece was evaluated. Moreover, the fuel permeation | transmission test based on JISZ0208 was done using the plate of thickness 1mm shape | molded on the molding conditions. The obtained results are shown in Table 1.

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

Claims (8)

  (A) Amino end group concentration> carboxyl end group concentration 100 parts by weight of crystalline polyamide resin and (B) layered silicate uniformly dispersed in the polyamide resin 0.05 to 10 parts by weight Polyamide resin composition with excellent fuel resistance.   The polyamide resin composition according to claim 1, wherein the amino terminal group concentration is 50 milliequivalents or more per kg of the polymer.   The polyamide resin composition according to claim 1, wherein the crystalline polyamide resin is an aliphatic polyamide resin comprising an aliphatic diamine and an aliphatic dicarboxylic acid, or comprising a lactam or an aminocarboxylic acid.   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.   2. The layered silicate has a side length of 0.002 to 1 μm and a thickness of 6 to 20 mm, and each layer is uniformly dispersed in the polyamide resin while maintaining an average interlayer distance of 20 mm or more. The polyamide resin composition as described.   (A) Polyamide resin comprising 100 parts by weight of crystalline polyamide resin in which amino terminal group concentration> carboxyl terminal group concentration and (B) 0.05 to 10 parts by weight of layered silicate dispersed uniformly in the polyamide resin A fuel component that uses the composition and has excellent fuel resistance at the welded portion.   A fuel part excellent in fuel resistance of a welded portion, wherein the polyamide resin composition according to claim 1 and a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof are welded.   After molding a polyolefin resin modified with an unsaturated carboxylic acid or derivative thereof, the polyamide resin composition according to claim 1 is injection-molded, and both molded articles are welded. Excellent fuel component manufacturing method.

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