JPH10292105A - Polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide resin composition balancedly excellent in surface smoothness, toughness, extrusion moldability, electrostatic properties, etc., especially suitable for blow molding, by making the composition include specified amounts of a polyamide, a plasticizer and an electroconductive filler. SOLUTION: This composition comprises (A) 100 pts.wt. of a polyamide resin, which is a homopolyamide composed of a structural unit containing preferably 8-15 carbon atoms on the average per amide group or a copolyamide resin containing 8-15 carbon atoms per amide group, (B) 1-25 pts.wt. of a plasticizer such as a compound of formula I [R1 to R6 are each a sulfonamido of formula II (R7 and R8 are each H, a 1-20C alkyl, alkenyl, etc.) (especially preferably an aromatic sulfonamide such as N-butylbenzensulfonamide) or a polyhydric alcohol and (C) 1-100 pts.wt. of an electroconductive filler preferably in a powdery, granular, laminar, scaly, or fibrous shape having the ratio of length/ diameter of <=200, such as metal powder or carbon powder.

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 having excellent surface smoothness, toughness, extrudability, and antistatic properties, and to a material particularly suitable for hollow molding. is there.

[0002]

2. Description of the Related Art A hollow molded article of a thermoplastic resin is manufactured by, for example, a blow molding method using a polyamide resin, mainly for ducts in an engine room of an automobile, or a saturated polyester resin or polyamide for a tube. 2. Description of the Related Art A technique of manufacturing by extrusion using a resin, a polyolefin resin, or a thermoplastic polyurethane has been widely used.

[0003] In particular, for automotive fuel tubes, polyamide resins, especially flexible polyamide resins such as polyamide 11 and polyamide 12, are widely used. In flowing applications, the molded article may be charged, and it is required to suppress this.

A polyamide-based multilayer pipe having conductivity is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-24889. However, in our study, multilayer tubes consisting of a composition containing only a conductive filler in a polyamide resin and a polyamide resin not containing a conductive filler have insufficient low-temperature impact resistance often required for automotive tubes. It was a result. In addition, a composition obtained by simply mixing and melting and kneading an elastomer together with a conductive filler to a polyamide resin to improve impact resistance is excellent in surface smoothness in a molding method under high pressure such as injection molding. Although a molded body with extremely high impact resistance is obtained, extrusion molding, when applied to a molding method in which high pressure is not applied such as blow molding, projections are easily generated on the surface, and the result is inferior surface smoothness, From the comparison with the impact resistance of the injection-molded piece, it was found that the formation of such projections resulted in a decrease in impact resistance.

[0005] Therefore, we have studied to obtain an excellent polyamide resin composition in balance with antistatic properties, impact resistance, moldability and surface smoothness, and blended a plasticizer with the polyamide resin and the conductive filler. As a result, it has been found that antistatic properties can be imparted and impact resistance and surface smoothness can be improved.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to obtain a conductive polyamide resin composition which has improved surface smoothness and impact resistance especially when applied to a blow molding method. I do.

[0007]

That is, the present invention provides the following polyamide resin composition and molded article.

(1) A polyamide resin composition containing (A) 100 parts by weight of a polyamide resin, (B) 1 to 25 parts by weight of a plasticizer, and (C) 1 to 100 parts by weight of a conductive filler.

(2) The polyamide resin (A) is a homopolyamide resin comprising a structural unit having an average number of carbon atoms per amide group in the range of 8 to 15, or an average number of carbon atoms per amide group is 8 The polyamide resin composition according to the above (1), which is a copolymerized polyamide resin having a range of from 15 to 15.

(3) The polyamide resin (A) is a polyamide resin having a relative viscosity of 1.5 to 5.0 measured at 25 ° C. in meta-cresol (polymer concentration: 0.5% by weight). The polyamide resin composition according to 2).

(4) The polyamide resin composition according to any one of the above (1) to (3), wherein the polyamide resin (A) is polyamide 11.

(5) The plasticizer (B) is one or two selected from a compound represented by the following formula (I) or a polyhydric alcohol.
The polyamide resin composition according to any one of the above (1) to (4), which is a compound of at least one kind.

[0013]

Embedded image (Wherein, R1 to R6 are

Embedded image A sulfonamide group, -OH group, -COOR9
An ester group represented by the formula, hydrogen, a halogen group, and having 1 to 1 carbon atoms
A group selected from 20 alkyl groups, alkenyl groups, aralkyl groups, and aromatic groups. Here, R7 and R8 represent hydrogen or a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. R9 represents a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. However, R1 to R6
At least one of the above is a sulfonamide group, -OH
Or a group selected from the above ester groups. (6) (C) The conductive filler is a conductive filler in any form of powder, granule, plate, scale, or fibrous having a length / diameter ratio of 200 or less. The polyamide resin composition according to any one of the above (1) to (5).

(7) The polyamide resin composition according to any one of the above (1) to (6), wherein the (C) conductive filler is a carbon powder.

(8) The polyamide resin composition according to the above (7), wherein the carbon powder (B) is a carbon powder having a specific surface area of 500 to 1500 m ² / g determined by the BET method.

(9) The polyamide resin composition according to any one of (7) to (8), wherein the (B) carbon powder is a carbon powder having a DBP oil absorption of 370 ml / 100 g or more.

(10) The content of (B) the carbon powder is
(A) The polyamide resin composition according to any one of the above (7) to (9), which is 3 to 20 parts by weight based on 100 parts by weight of the polyamide resin.

(11) The polyamide resin composition according to any one of the above (1) to (10), which has a volume resistivity of 10 ¹⁰ Ω · cm or less.

(12) A polyamide resin composition was melted with a melt indexer (temperature = melting point + 60 ° C., residence time 5 minutes, load 5 kg, orifice diameter 0.0825 inch, length 0.25 mm).
315 inches) to obtain a gut, and when the gut is projected by a projector, protrusions having a height of 25 μm or more observed on the gut surface have a size of 5 g / cm.
The polyamide resin composition according to any one of the above (1) to (11), wherein the number is not more than one.

(13) The polyamide resin composition according to any one of the above (1) to (12), wherein the polyamide resin composition is for hollow molding.

(14) The polyamide resin composition according to any one of the above (1) to (12), wherein the polyamide resin composition is for multilayer hollow molding.

(15) A multilayer hollow molded article comprising at least two polymer layers, wherein the polyamide resin composition according to any one of the above (1) to (12) is used for at least one layer. .

(16) A multilayer hollow tubular molded article comprising at least two types of polymer layers, wherein the polyamide resin composition according to any one of the above (1) to (12) is used for at least one layer, and is co-extrusion molded. Multi-layer tubular molded article produced by the method.

(17) An automotive fuel tube using the multilayer hollow molded article according to (15) or the multilayer tubular hollow molded article according to (16).

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyamide resin (A) used in the present invention is a polyamide containing amino acids, lactams or diamines and dicarboxylic acids as main components.
Representative examples of the main components include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid;
Lactams such as aminocaprolactam and ω-laurolactam, tetramethylenediamine, hexamerenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnona Methylenediamine, metaxylenediamine, paraxylylenediamine, 1,3-
Bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane,
Bis (4-aminocyclohexyl) methane, bis (3-
Methyl-4-aminocyclohexyl) methane, 2,2-
Bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine,
Aliphatic, alicyclic, aromatic diamines such as 2-methylpentamethylenediamine, and adipic acid, spearic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, −
Aliphatic, alicyclic, such as methyl terephthalic acid, 5-methyl isophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid;
An aromatic dicarboxylic acid is mentioned, and in the present invention,
The polyamide homopolymer or copolymer derived from these raw materials can be used alone or in the form of a mixture.

In the present invention, useful polyamide resins include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), and polyhexamethylene sebacamide. (Nylon 610), polyhexamethylene dodecamide (nylon 612), polydodecaneamide (nylon 12), polyundecaneamide (nylon 1
1), polyhexamethylene terephthalamide (nylon 6T), polyxylylene adipamide (nylon XD6)
Homopolyamide resins and copolymers thereof, and the like, which can be used alone or as a mixture.

Above all, a homopolyamide resin comprising a structural unit having an average number of carbon atoms per amide group in the range of 8 to 15, or an average carbon number per amide group of 8 to 15 is preferred.
A copolymer polyamide resin having a range of 15 is preferable in terms of obtaining more excellent toughness and extrudability, and such polyamides include polydodecaneamide (nylon 12), polyundecaneamide (nylon 11), and polyundecamethylene. Examples thereof include dodecamide (nylon 1112) and polydodecamethylene dodecamide (nylon 1212), and particularly preferred is polyundecaneamide (nylon 11).

The degree of polymerization of these polyamide resins is not particularly limited. For example, 98% concentrated sulfuric acid solution (1 g of polymer,
Concentrated sulfuric acid 100 ml), the relative viscosity measured at 25 ° C.
A range of 1.5 to 7.0, particularly 2.0 to 6.5, and further a range of 2.0 to 5.5 can be exemplified. Alternatively, in metacresol (polymer concentration: 0.5% by weight), 25 C. and a relative viscosity in the range of 1.0 to 7.0, in particular 1.5 to 5.
A polyamide resin in the range of 0 can be exemplified.

The plasticizer (B) used in the present invention is not particularly limited as long as it is a plasticizer effective for a polyamide resin, but is preferably a compound represented by the following formula (I) or a polyhydric alcohol.

[0030]

Embedded image (Wherein, R1 to R6 are

Embedded image A sulfonamide group, -OH group, -COOR9
An ester group represented by the formula, hydrogen, a halogen group, and having 1 to 1 carbon atoms
A group selected from 20 alkyl groups, alkenyl groups, aralkyl groups, and aromatic groups. Here, R7 and R8 represent hydrogen or a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. R9 represents a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. However, R1 to R6
At least one of the above is a sulfonamide group, -OH
Or a group selected from the above ester groups. ) Specific examples of the compound of the above formula (I) include N-butylbenzenesulfonamide, N-ethylbenzenesulfonamide, N-ethyl-o, p-toluenesulfonamide,
Aromatic sulfonamides such as N, N'-dibutylbenzenesulfonamide, N-propylbenzenesulfonamide, p-hydroxybenzoic acid-n-octyl ester;
and hydroxybenzoic acid esters such as p-hydroxybenzoic acid-2-ethylhexyl ester.
The polyhydric alcohol is a compound having two or more hydroxyl groups in a molecule, and specific examples thereof include ethylene glycol, glycerin, 2-methyl-2,4-pentanediol, and 2,2,4-trimethyl. -1,3-pentanediol and the like. Among them, N-butylbenzenesulfonamide, N-ethylbenzenesulfonamide, N-ethyl-o, p-toluenesulfonamide,
Aromatic sulfonamides such as N, N'-dibutylbenzenesulfonamide and N-propylbenzenesulfonamide are particularly preferred.

The amount of the plasticizer (B) is based on 100 parts by weight of the polyamide resin (A),
A range of 5 parts by weight is selected, particularly a range of 4 to 20 parts by weight is preferable, and a range of 8 to 17 parts by weight is more preferable. If the amount of the plasticizer is less than 1 part by weight, the impact resistance is significantly reduced,
If the amount exceeds 25 parts by weight, adverse effects such as volatilization during extrusion molding become apparent, which is not preferable.

Next, the conductive filler (C) will be described. The conductive filler is not particularly limited as long as it is a conductive filler that is usually used for making the resin conductive. Specific examples thereof include metal powder, metal flake, metal ribbon, metal fiber, metal oxide, and a conductive substance. Examples thereof include a coated inorganic filler, carbon powder, graphite, carbon fiber, carbon flake, and flaky carbon.

Specific examples of the metal species of the metal powder, metal flake, and metal ribbon include silver, nickel, copper, zinc, aluminum, stainless steel, iron, brass, chromium, and tin.

Specific examples of the metal species of the metal fiber include iron,
Examples thereof include copper, stainless steel, aluminum, and brass.

The metal powder, metal flake, metal ribbon and metal fiber may be subjected to a surface treatment with a surface treating agent such as a titanate, aluminum or silane.

Specific examples of the metal oxide include SnO ₂ (antimony doped), In ₂ O ₃ (antimony doped), Z
Examples thereof include nO (aluminum dope), and these may be subjected to a surface treatment with a surface treating agent such as a titanate, aluminum, or silane.

Specific examples of the conductive material in the inorganic filler coated with the conductive material include aluminum, nickel, silver, carbon, SnO ₂ (antimony-doped),
Examples include n ₂ O ₃ (antimony doping). As the inorganic filler to be coated, mica, glass beads, glass fiber, carbon fiber, potassium whisker,
Examples include barium sulfate, zinc oxide, titanium oxide, aluminum borate whiskers, zinc oxide whiskers, titanic acid whiskers, and silicon carbide whiskers. Examples of the coating method include a vacuum deposition method, a sputtering method, an electroless plating method, and a baking method. These may be subjected to a surface treatment with a surface treating agent such as titanate, aluminum, or silane.

The carbon powder is classified into acetylene black, gas black, oil black, naphthalene black, thermal black, furnace black, lamp black, channel black, roll black, disk black and the like according to its raw material and production method. The raw material and the production method of the carbon powder that can be used in the present invention are not particularly limited, but acetylene black and furnace black are particularly preferably used. Various carbon powders having different properties such as particle diameter, surface area, DBP oil absorption, and ash content are produced. The carbon powder that can be used in the present invention is not particularly limited in these characteristics. However, a large amount of carbon powder is not preferable in terms of impact resistance, and the average particle size is small in order to obtain excellent electric conductivity with a smaller amount. The diameter is 500 nm or less, especially 5 to 10
0 nm, more preferably 10 to 70 nm, and the surface area (BET method) is 10 m ² / g or more, more preferably 300 m ² / g.
As described above, it is particularly preferably 500 to 1500 m ² / g, and the DBP oil absorption is 50 ml / 100 g or more, particularly 100 m ² / g.
1/100 g, more preferably 370 ml / 100 g or more. The ash content is preferably 0.5% or less, particularly preferably 0.3% or less.

The carbon powder may be subjected to a surface treatment with a surface treating agent such as a titanate, aluminum, or silane. It is also possible to use those granulated for improving the workability of the melt-kneading.

From the viewpoint of obtaining excellent surface smoothness, the conductive filler used in the present invention is more powdery, granular, plate-like, scale-like, or resinous than fibrous filler having a high aspect ratio. It is preferable that the medium has any fibrous form having a length / diameter ratio of 200 or less.

The above-mentioned conductive fillers may be used in combination of two or more kinds. Among such conductive fillers, carbon powder is particularly preferably used in terms of strength and cost.

Although the preferred content of the conductive filler used in the present invention varies depending on the type of the conductive filler used, it cannot be unconditionally specified. However, from the viewpoint of the balance between conductivity, fluidity, mechanical strength and the like. , (A) In general, the range is preferably 1 to 100 parts by weight, preferably 2 to 50 parts by weight, more preferably 3 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin.

For example, one of the preferred conductive fillers used in the present invention, the average particle size is 500 nm or less,
Surface area (BET method) is 500 to 1500 m ² / g, DB
The amount of the carbon black having a P oil absorption of 370 ml / 100 g or more is preferably selected in the range of 3 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin (A).

The conductive resin composition has a volume resistivity of 10 ¹⁰ Ω · cm in order to obtain sufficient antistatic performance.
Below, it is particularly preferred that it is 10 ⁴ Ω · cm or less.
However, the mixing of the conductive filler tends to cause deterioration in strength and fluidity. Therefore, if the target conductivity level can be obtained, it is desirable that the amount of the conductive filler is as small as possible. The target conductivity level depends on the application, but is usually in the range of more than ¹ Ω · cm and not more than 10 ¹⁰ Ω · cm.

The polyamide resin composition of the present invention may contain a resin other than the polyamide resin as long as the effects of the present invention are not impaired. Specific examples thereof include a saturated polyester resin, a polysulfone resin, a polyethylene tetrafluoride resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polyimide resin, a polycarbonate resin, a polyethersulfone resin, a polyetherketone resin, and a polythioetherketone. Resin, polyether ether ketone resin, thermoplastic polyurethane resin, polyolefin resin, ABS resin, polyamide elastomer, polyester elastomer, polyphenylene sulfide resin, polyphenylene ether resin, or polyethylene, polypropylene, polystyrene, ethylene-propylene copolymer, ethylene- Butene copolymer, polybutene, ethylene-propylene-diene copolymer, styrene-butadiene copolymer, polybutadiene, butane Diene -
Acrylonitrile copolymer, polyisoprene, butene
Polyolefin resins such as isoprene copolymers, SBS, SEBS, or these polyolefin resins are added to maleic anhydride, succinic anhydride, fumaric anhydride, acrylic acid, methacrylic acid, vinyl acetate and their Na, Z
Salts of n, K, Ca, Mg, etc., methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate And olefin copolymers obtained by copolymerizing glycidyl ethacrylate and the like.

The polyamide resin composition of the present invention is a resin composition particularly suitable for multilayer blow molding. The resin laminated with the polyamide resin composition of the present invention is not particularly limited,
Specific examples thereof include a polyamide resin alone or a polyamide resin composition that does not satisfy the requirements of the present invention, polyphenylene sulfide resin, saturated polyester resin, polysulfone resin, polyethylene tetrafluoride resin, polyetherimide resin, polyamideimide resin, polyamide resin. ,
Polyimide resin, polycarbonate resin, polyether sulfone resin, polyether ketone resin, polythioether ketone resin, polyether ether ketone resin, thermoplastic polyurethane resin, polyolefin resin, ABS
Examples thereof include resins, polyamide elastomers, polyester elastomers, ETFE, and PVDF, and these may be used as a mixture of two or more. Among them, a polyamide resin, a thermoplastic polyester resin, a thermoplastic polyurethane resin, and a polyolefin resin alone or a composition thereof are more preferably used. Further, polyamide resin compositions satisfying the requirements of the present invention may be laminated.

Specific examples of the polyamide resin are the same as the specific examples of the polyamide resin (A) described above, and thus description thereof is omitted.

The thermoplastic polyester resin used herein includes polyester obtained from a dicarboxylic acid such as terephthalic acid and an aliphatic diol. Examples of dicarboxylic acids other than terephthalic acid include azelaic acid, sebacic acid, adipic acid, dodecanedicarboxylic acid, isophthalic acid, and other aliphatic dicarboxylic acids having 2 to 20 carbon atoms, isophthalic acid, and aromatic dicarboxylic acids such as naphthalenedicarboxylic acid. Or an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, which may be used alone or in a mixture. Examples of the aliphatic diol include ethylene glycol, propylene glycol, 1,4-butanediol, trimethylene glycol, 1,4-cyclohexanedimethanol, and hexamethylene glycol.

Preferred examples of the thermoplastic polyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polycyclohexylene dimethylene terephthalate, and polyethylene naphthalate. Among them, suitable mechanical strength is obtained. Having 60 mol% of polybutylene terephthalate or terephthalic acid
As described above, a copolyester comprising a dicarboxylic acid component containing dodecanedicarboxylic acid and / or isophthalic acid in an amount of 70 mol% or more and 1,4-butanediol component is particularly preferably used.

The degree of polymerization of these thermoplastic polyester resins is not particularly limited. For example, in the case of polybutylene terephthalate (hereinafter abbreviated as PBT resin) and copolyester, which are preferably used, the degree of polymerization is preferably
The relative viscosity of a 0.5% orthochlorophenol solution measured at 25 ° C. is in the range of 0.5 to 2.5, especially 0.8 to 2.
Those in the range of 0 are preferred. In the case of polyethylene terephthalate, the intrinsic viscosity of a 0.5% orthochlorophenol solution measured at 25 ° C. is preferably in the range of 0.54 to 1.5, particularly preferably 0.6 to 1.2.

The thermoplastic polyurethane resin is a chain polymer composed of a polyisocyanate and a diol. Specific examples of the polyisocyanate include 2,4-tolylene diisocyanate, hexamethylene diisocyanate, meta-xylene diisocyanate, and 4,4. 4'-diphenylmethane diisocyanate and the like. Diols include polyester type and polyether type.Specific examples of the former include organic acids such as phthalic acid, adipic acid, dimerized linoleic acid, and maleic acid, and glycols such as ethylene, propylene, butylene, and diethylene. The specific examples of the latter include polyoxypropylene glycol, poly (oxypropylene) poly (oxymethylene) glycol, poly (oxybutylene) glycol, poly (oxytetramethylene) glycol, and the like, respectively. Used for

The degree of polymerization of these polythermoplastic polyurethanes is not particularly limited.
A melt viscosity of 1000 to 100,000 poise / sec is used.

The polyolefin resin includes polyethylene, polypropylene, chlorinated polyethylene, chlorinated polypropylene, polyvinyl alcohol and polymethylpentene.

The number of layers and the order of lamination of the multilayer hollow molded article of the present invention are not particularly limited, and specific examples thereof include two or three or more layers in which the polyamide resin composition of the present invention is disposed as the innermost layer. Hollow molded article, two or three or more hollow molded articles in which the polyamide resin composition of the present invention is arranged in the outermost layer, three or four or more layers in which the polyamide resin composition of the present invention is arranged in the intermediate layer In particular, a two-layer hollow molded article in which the polyamide resin composition of the present invention is disposed in the innermost layer, and three or four or more layers in which the polyamide resin composition of the present invention is disposed in the intermediate layer Is preferred.

Further, the polyamide resin composition of the present invention and the resin composition laminated therewith may contain a filler according to the purpose and application within a range not to impair the scope of the present invention. Shape or non-fibrous shape. Specific examples of such a filler include glass fiber, glass milled fiber, carbon fiber, potassium whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber,
Fibrous filler such as asbestos fiber, masonry fiber, metal fiber, silicate, alumina, oxidized silicate such as walasteinite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate Metal compounds such as silicon, magnesium oxide, zirconium oxide, titanium oxide and iron oxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; sulfates such as calcium sulfate and barium sulfate; magnesium hydroxide; calcium hydroxide; Non-fibrous fillers such as hydroxides such as aluminum, glass beads, ceramic beads, boron nitride, silicon carbide and silica, and carbon black may be used. These may be hollow. More than one type can be used together . In addition, when these fillers are pre-treated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound, more excellent mechanical strength can be obtained. Preferred in meaning.

When such a filler is used, the compounding amount is preferably in the range of usually 5 to 150 parts by weight based on 100 parts by weight of the composition comprising the resin and the plasticizer.

Further, the polyamide resin composition of the present invention and the resin composition laminated therewith include a plasticizer, a crystal nucleating agent, a coloring inhibitor, an antioxidant, a heat stabilizer, a lubricant, an ultraviolet ray inhibitor, and a coloring agent. Ordinary additives such as a flame retardant and a foaming agent can be added.

One object of the present invention is to obtain a conductive polyamide resin composition having excellent impact resistance and excellent surface smoothness. Specifically, the melt indexer (3
(15.5 ° C., residence time: 5 minutes, load: 5 kg, orifice diameter: 0.0825 inch, length: 0.315 inch) Obtained on the surface of the gut when the gut obtained by throwing the gutter is projected by a projector. The number of protrusions having a height of 25 μm or more is preferably 5 or less per cm, preferably 2 or less, particularly preferably 1 or less.

The method for preparing the polyamide resin composition of the present invention is not particularly limited as long as the above excellent surface properties, conductivity and impact resistance are obtained.
A typical example is a method of feeding to a known melt mixer such as a shaft extruder, a Banbury mixer, a kneader and a mixing roll and kneading at a temperature 10 to 80 ° C higher than the melting point of the polyamide resin, preferably 20 to 50 ° C higher. Examples can be given.

The order of compounding is not particularly limited.
Polyamide resin, (B) plasticizer and (C) conductive filler may be simultaneously compounded and melt-kneaded.
A multi-stage kneading method may be used, in which a polyamide resin, (B) a plasticizer and a part of (C) a conductive filler are melt-kneaded, and then the obtained composition and the remaining compounding materials are blended and melt-kneaded. Further, as a multi-stage kneading method, a method in which the first-stage composition is supplied from a main hopper and the second-stage composition is supplied from a side feeder can also be mentioned.

Further, when a small amount of an additive component is used,
After kneading other components by the above method and pelletizing,
Of course, it is also possible to add it before the forming process and to provide it for forming.

The composition of the present invention is suitable for producing hollow molded articles such as tube molded articles and blow molded articles, and is particularly suitable for producing multilayer hollow molded articles by coextrusion. The hollow molded article of the present invention is a bottle because it has excellent impact resistance, surface smoothness, and antistatic properties.
It is preferably used for tanks, pipes, ducts, tubes, and the like, and is particularly preferably used for automotive fuel tube applications, but is not limited to such a hollow molding method, and other extrusion molding methods such as a round bar, injection molding methods, Of course, application to other molding methods such as a transfer molding method is also possible.

[0063]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Further, the surface smoothness in the following examples,
Volume resistivity, notched impact strength, tube toughness
It carried out by the following method.

[Surface Smoothness] A polyamide resin composition pellet was melted with a melt indexer (Type, manufactured by Toyo Seiki Co., Ltd.).
C-5059D2-1, orifice diameter 0.0825 inch, length 0.315 inch), stayed at the melting point of the polyamide resin + 60 ° C. for 5 minutes, and extruded gut with a load of 5 kg. This operation was performed ten times to obtain ten guts. The gut was projected by a projector (Nikon Corp., profile projector, V-12), and the number of protrusions having a height of 25 μm or more on the gut surface was observed. Observation was performed for 10 guts each of 5 cm, a total of 50 cm, and the number was counted as the number of protrusions observed per cm.

[Notched Impact Strength] The polyamide resin composition pellets were subjected to injection molding under the conditions of (A) the melting point of the polyamide resin + 50 ° C. and the mold temperature of 80 ° C. to form a measurement sample. Using this sample, the notched Izod impact strength at 23 ° C. was measured according to the ASTM D256 method.

[Volume Specific Resistance] Using a polyamide resin composition pellet, resin thickness: 0.3A under conditions of (A) the melting point of the polyamide resin + 50 ° C. and the mold temperature 70 ° C.
A molded product having a diameter of 100 mm and a diameter of 100 mm was molded by injection molding, and this was used as a sample. Takeda Riken Industry Co., Ltd.
TR6877 Computing Digital Multimeter was used.

[Evaluation of Low Temperature Toughness of Tube] Ten tubes each having a length of 30 cm were prepared and left in a cooling device at -40 ° C for 4 hours. Remove the tube from the cooling device,
A 0.454 kg weight was dropped onto the tube from a height of 304.8 mm, and the presence or absence of breakage of the tube was observed.

[Compounding Materials Used in Examples and Comparative Examples] (A) Thermoplastic resin A-1: Nylon 12 (relative viscosity 2.2) pellet A-2: Nylon 12 (relative viscosity 1.4) pellet A -3: Nylon 11 (relative viscosity 2.2) pellets The relative viscosity was measured in meta-cresol (polymer concentration 0.5% by weight) at 25 ° C.

(B) Plasticizer B-1: N-butylbenzenesulfonamide B-2: P-hydroxybenzoic acid-2-ethylhexyl (C) Conductive filler C-1: Carbon black (Ketjen Black International EC600JD, DBP oil absorption 495 ml / 100 g, BET surface area 1270 m ² /
g, average particle size 30 nm, ash content 0.2% C-2: carbon black (Mitsubishi Kasei Kogyo Co., Ltd. Mitsubishi conductive carbon black # 3050, DBP oil absorption 18)
0 ml / 100 g, BET method surface area 50 m ² / g, ash content 0.2% Examples 1 to 5 Each blended material shown in Table 1 was dry-blended at a ratio shown in Table 1 and preliminarily mixed in a tumbler for 2 minutes. The mixture was melt-kneaded with a twin-screw extruder in which the cylinder temperature was set to (A) the melting point of the polyamide resin + 35 ° C, pelletized by a strand cutter, and dried overnight. Using such pellets,
Form a molded body for measuring impact strength and volume resistivity,
The surface smoothness was measured. Table 1 shows the results.

Comparative Example 1 (B) Melt kneading, pelletizing and drying were carried out in the same manner as in Examples 1 and 2, except that no plasticizer was used. Using these pellets, a molded article for measuring impact strength and volume resistivity was molded, and the surface smoothness and melt viscosity were measured. Table 1 shows the results.

Evaluation of tube forming (1) Semi-soft polyamide 12 manufactured by Toray Industries, Inc., AESN
Using OP20TL, using the pellets obtained in Examples 1 to 4 or Comparative Example 1 for the inner layer, outer diameter: 8 mm, inner diameter:
6 mm, outer layer thickness: 0.8 mm, inner layer thickness: 0.2 mm
Was formed. As the molding device, two single-screw extruders of 65 mm set at a resin temperature of 240 ° C., a die for collecting the resin discharged from the two extruders by an adapter and forming the same into a tube shape, cooling the tube, and measuring the size. Using a sizing die to be controlled and a take-off machine, a tube was formed at a take-up speed of 50 cm / min, and the tube low-temperature toughness was evaluated using this tube. Table 1 shows the results.

Evaluation of tube forming (2) Semi-soft polyamide 11, BESN manufactured by Toray Industries, Inc.
Using OP20TL, the pellet obtained in Example 5 for the inner layer, outer diameter: 8 mm, inner diameter: 6 mm, outer layer thickness:
A two-layer tube having a thickness of 0.8 mm and an inner layer thickness of 0.2 mm was formed. As the molding device, two single-screw extruders of 65 mm set at a resin temperature of 240 ° C., a die for collecting the resin discharged from the two extruders by an adapter and forming the same into a tube shape, cooling the tube, and measuring the size. Using a sizing die to be controlled and a take-off machine, a tube was formed at a take-up speed of 50 cm / min, and the tube low-temperature toughness was evaluated using this tube. Table 1 shows the results.

[0074]

[Table 1]

[0075]

Industrial Applicability The polyamide resin composition of the present invention is excellent in balance of surface smoothness, toughness, extrudability, antistatic property, etc., and is particularly suitable for hollow molding.

Claims (17)

[Claims] (A) 100 parts by weight of a polyamide resin,
A polyamide resin composition containing (B) 1 to 25 parts by weight of a plasticizer and (C) 1 to 100 parts by weight of a conductive filler. 2. The polyamide resin (A) is a homopolyamide resin comprising a structural unit having an average number of carbon atoms per amide group in the range of 8 to 15, or an average carbon number per amide group of 8 to 15. The polyamide resin composition according to claim 1, which is a copolymerized polyamide resin having a range of 15. 3. The polyamide resin (A) having a relative viscosity of 1.5 to 5.0 measured at 25 ° C. in meta-cresol (polymer concentration: 0.5% by weight). The polyamide resin composition according to the above. 4. The method according to claim 1, wherein (A) the polyamide resin is polyamide 11
The polyamide resin composition according to any one of claims 1 to 3, wherein 5. The polyamide resin composition according to claim 1, wherein (B) the plasticizer is one or more compounds selected from the compounds of the following formula (I) or polyhydric alcohols. Embedded image (Wherein, R1 to R6 are A sulfonamide group, -OH group, -COOR9
An ester group represented by the formula, hydrogen, a halogen group, and having 1 to 1 carbon atoms
A group selected from 20 alkyl groups, alkenyl groups, aralkyl groups, and aromatic groups. Here, R7 and R8 represent hydrogen or a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. R9 represents a group selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aralkyl group, and an aromatic group. However, R1 to R6
At least one of the above is a sulfonamide group, -OH
Or a group selected from the above ester groups. ) 6. The conductive filler (C) is a powdery, granular, plate-like, scale-like or fibrous form having a length / diameter ratio of 200 or less. The polyamide resin composition according to claim 1. 7. The polyamide resin composition according to claim 1, wherein the conductive filler (C) is a carbon powder. 8. The polyamide resin composition according to claim 7, wherein (B) the carbon powder has a specific surface area of 500 to 1500 m ² / g determined by the BET method. 9. The carbon powder (B) has a DBP oil absorption of 37.
The polyamide resin composition according to any one of claims 7 to 8, wherein the carbon powder is 0 ml / 100 g or more. 10. The content of (B) the carbon powder is (A)
The polyamide resin composition according to any one of claims 7 to 9, wherein the amount is 3 to 20 parts by weight based on 100 parts by weight of the polyamide resin. 11. The polyamide resin composition according to claim 1, which has a volume resistivity of 10 ¹⁰ Ω · cm or less. 12. A polyamide resin composition is melt-indexed (temperature = melting point + 60 ° C., residence time 5 minutes, load 5k).
g, orifice diameter 0.0825 inch, length 0.31
5 inches) to obtain a gut, and when the gut is projected by a projector, the number of protrusions having a height of 25 μm or more observed on the gut surface is 5 or less per cm of the gut. Any polyamide resin composition. 13. The polyamide resin composition according to claim 1, wherein the polyamide resin composition is for hollow molding. 14. The polyamide resin composition according to claim 1, wherein the polyamide resin composition is for multi-layer hollow molding. 15. A multilayer hollow molded article comprising at least two polymer layers, wherein at least one layer has at least one layer.
13. A multilayer hollow molded article using the polyamide resin composition according to any one of items 12 to 12. 16. A multilayer hollow tubular molded article comprising at least two kinds of polymer layers, wherein the polyamide resin composition according to claim 1 is used for at least one layer and produced by a coextrusion molding method. Multi-layer tubular molded body. 17. A fuel tube for an automobile using the multilayer hollow molded article according to claim 15 or the multilayer tubular hollow molded article according to claim 16.