JP4322065B2 - Conductive polyamide resin composition - Google Patents

Description

  The present invention relates to a polyamide resin composition. Specifically, the present invention relates to a polyamide resin composition excellent in conductivity, mechanical properties and appearance.

  Polyamide resins represented by polyamide-6 and polyamide-66 are widely used mainly for automotive parts, electrical and electronic parts, building materials, food packaging film applications, etc. due to their excellent mechanical properties, chemical resistance, moldability and appearance. in use.

  In addition, when a conductive material is blended with polyamide resin, which is inherently insulating, it exhibits excellent conductivity, so products that are electrostatically coated mainly in electrical and electronic parts, automobile parts, etc., electromagnetic shielding and antistatic properties Is used in products that require

  In addition to ionic surfactants and polymer antistatic agents having polyethylene glycol units, conductive powders blended with polyamide resins are known, such as metal powders, metal fibers, carbon fibers, and carbon black. Conductive carbon black is most widely used.

  The reason why conductive carbon black is most widely used is that it is excellent in economy with respect to other conductivity improving substances, and the conductivity can be adjusted to some extent by the amount of carbon black. .

  However, conductive carbon black greatly reduces the impact strength, tensile toughness, appearance, fluidity, etc. of polyamide resin, so it is a technical issue to demonstrate excellent conductivity with as little carbon black content as possible. ing.

  In order to solve this problem, there is a method in which carbon fiber, metal powder, and other various conductive materials such as metal fiber are further used in combination with conductive carbon black. However, metal powder and metal fiber have a large specific gravity. The resulting resin composition inevitably becomes heavy, and the carbon fiber has the disadvantage of greatly reducing the appearance and impact resistance. Furthermore, these conductivity improving materials are all economical compared to carbon black. There were many restrictions on actual use, such as a major disadvantage.

  As another technique, an attempt has been reported to improve conductivity by blending other carbon-compatible thermoplastic resin with polyamide containing conductive carbon black.

  For example, in Patent Document 1, a composition improved in conductivity by blending with other thermoplastic resin such as polypropylene resin, which is not only incompatible but also poor in compatibility, In Patent Document 2, a composition containing a modified olefin-based elastomer having no compatibility with a polyamide resin but having compatibility is used. In Patent Document 3, there is still no compatibility with a polyamide resin. The composition which mix | blended the acid-modified polyphenylene ether resin (henceforth PPE resin) which has property is disclosed.

  Certainly, by blending these resins that are not compatible with the polyamide resin, the amount of polyamide resin forming the continuous phase is reduced, and the carbon black concentration in the polyamide resin continuous phase is increased. Can do. However, in order to obtain a large conductivity improvement effect by this method, it is necessary to blend a large amount of these resins that are not compatible with the polyamide resin, and avoid sacrificing the excellent characteristics inherent in the polyamide resin. I couldn't.

  On the other hand, it supplements about the compatibility (solvability) which is the point of this invention.

  When a certain component (referred to as b) that is not component (a) is added to a certain crystalline polyamide resin (referred to as a), the crystallization temperature or glass transition temperature of (a) alone is In the case where the substance added with (b) becomes lower, (a) can be considered to be soluble with respect to (b), and is a familiar substance. I can say that.

  On the other hand, although the crystallization temperature and the glass transition temperature do not decrease, in the case of taking a micro-dispersed phase structure, these two have compatibility but are not compatible. be able to.

  Moreover, when neither case is taken, it can be considered that both are not compatible.

  Next, a composition comprising a crystalline polyamide resin blended with a substance that has the effect of lowering the crystallization temperature of the polyamide resin. Or the composition which mix | blended the semi-aromatic polyamide resin is known.

  As an effect obtained by blending these substances with a crystalline polyamide resin, what has been widely known conventionally relates to an effect of remarkably improving the surface appearance of a polyamide resin blended with an inorganic filler such as glass fiber. . In addition, since nigrosine is a black dye, the effect of a crystalline polyamide resin as a black colorant is also known.

  On the other hand, since the weather resistance of the polyamide resin colored with nigrosine is larger than that of carbon black and the reinforced polyamide resin colored black, the weather resistance discoloration becomes larger.

  Below, the composition proposed concretely is introduced.

  For example, Patent Document 4 discloses a resin composition in which polyamide resin is blended with nigrosine, carbon black, and aniline black. Here, carbon black is blended not for the purpose of improving conductivity but for the purpose of coloring black, and nigrosine is also blended for the purpose of improving the appearance. There is no description suggesting the conductivity improvement effect.

  Patent Document 5 discloses a composition in which a semi-aromatic polyamide resin and carbon black, glass fiber, a copper-based heat stabilizer and the like are blended with an aliphatic polyamide resin. There is no description suggesting that the group polyamide resin can improve the conductivity.

Further, Patent Document 6 discloses a resin composition excellent in calcium chloride resistance, conductivity, and welding strength in which a semi-aromatic polyamide resin and carbon black are blended. Is an improvement in calcium chloride resistance and welding strength, and the conductivity is controlled by the type and amount of carbon black and combined use with carbon fiber, and the conductivity improving effect of the semi-aromatic polyamide resin is described. There is no.
As described above, it has been proposed that various qualities centering on the appearance can be improved by blending a substance having extremely good compatibility with the polyamide resin. However, when carbon black is blended with the polyamide resin, the polyamide resin is improved. It has not been known so far that a substance having an effect of lowering the crystallization temperature of the material significantly increases the conductivity.

In addition, the conventionally proposed methods for improving the conductivity of polyamide resins blended with carbon black have a small effect on improving the conductivity, and their use has many limitations.
Japanese Patent Laid-Open No. 50-32240 JP 58-93756 A Japanese Patent Laid-Open No. 02-201811 JP 09-67516 A Japanese Patent Laid-Open No. 2002-294069 JP 2000-038505 A

  The present invention has been intensively studied for the purpose of obtaining a resin composition excellent in conductivity, fluidity, and mechanical properties with respect to a resin composition having dramatically improved conductivity of a polyamide resin blended with carbon black. It is.

  As a result, it has been found that the conductivity is dramatically improved by blending a substance that delays the solidification rate of the polyamide resin, and the present invention has been achieved.

That is, the gist of the present invention is that
Component (A): 100 parts by weight of crystalline polyamide resin,
Component (B): 0.05 to 10 parts by weight of a substance that lowers the crystallization temperature of component (A) by 2 ° C. or more and Component (C): 2 to 30 weights of conductive carbon black with DBP oil absorption exceeding 150 ml / 100 g Part of the polyamide resin composition, wherein the component (B) is a semi-aromatic polyamide resin, and the conductivity represented by the volume resistivity of the molded article comprising the composition is 2 to 9 × 10 ⁴ Ωcm Ru der relates conductive polyamide resin composition characterized.

Hereinafter, the present invention will be described in detail.
Component (A): Crystalline polyamide resin
The crystalline polyamide resin used in the present invention is not particularly limited as long as it is a polyamide resin having a clear crystallization temperature according to a predetermined measurement method described below, but from the viewpoint of moldability and toughness, an aliphatic polyamide resin is usually used. Selected. Such an aliphatic polyamide resin is a polymerized ω-amino acid or a lactam thereof, preferably a lactam having a three or more-membered ring, or an aliphatic dibasic acid and an aliphatic diamine as raw materials. It is a polyamide resin obtained by polycondensation. Specifically, the raw material ω-amino acids include ε-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like. Examples of the lactam include ε-caprolactam, enantolactam, capryl lactam, lauryl lactam, α-pyrrolidone, and α-piperidone. Aliphatic dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, undecanedioic acid, dodecanedioic acid, hexadecanedioic acid, hexadecenedioic acid, eicosanedioic acid, eicosadiene Examples include diacid, diglycolic acid, 1,4-cyclohexanedicarboxylic acid, 2,2,4-trimethyladipic acid and the like. Moreover, aromatic dibasic acids, such as a terephthalic acid, an isophthalic acid, and xylylene dicarboxylic acid, are mentioned as a raw material which can be used in the range which does not impair the effect of this invention.

The raw material aliphatic diamines include hexamethylene diamine, dodecamethylene diamine, 2,2,4 (or 2,4,4) -trimethylhexamethylene diamine, bis (4,4′-aminocyclohexyl) methane, and the like. Is mentioned. Moreover, aromatic diamines, such as metaxylylene diamine, are mentioned as a raw material which can be used in the range which does not impair the effect of this invention.

  Among these crystalline polyamide resins, a polyamide resin mainly composed of ε-caprolactam and / or a polyamide resin composed of an aliphatic diamine having 6 carbon atoms and an aliphatic dicarboxylic acid having 6 carbon atoms is preferable. Is preferably polyamide-6, polyamide-66, or a copolymer of polyamide-6 and polyamide-66. Polyamide-6 is particularly preferred from the viewpoint of impact resistance, and polyamide-66 is preferred when heat resistance is important.

  The crystalline polyamide resin used in the present invention preferably has a relative viscosity of 2.0 to 5.0 measured in 23 ° C. and 98% concentrated sulfuric acid. If it is less than 2.0, the mechanical strength is insufficient, and if it exceeds 5.0, the moldability is inferior. Particularly preferred are those having a relative viscosity of 2.2 to 3.5.

Component (B): Substance that lowers the crystallization temperature of component (A) by 2 ° C. or more
The component (B) used in the present invention is a substance that lowers the crystallization temperature of the crystalline polyamide resin, which is the component (A), by 2 ° C. or more. About the component (A) simple substance before carrying out and the resin composition after mix | blending, respectively, according to the following measuring method, it measures by measuring "crystallization temperature" of crystalline polyamide resin, and comparing both measured values. If the crystallization temperature value of the resin composition containing the component (A) and the component (B) is confirmed to be 2 ° C. or more lower than the crystallization temperature value of the component (A) alone. It is determined that the requirements for component (B) are satisfied.

Of course, since the value of the crystallization temperature differs if the blending ratio is different, in the present invention, at least the blending ratio of the component (A) and the component (B) must satisfy the above requirements. .
Method for Measuring Crystallization Temperature of Crystalline Polyamide Resin Crystallization temperature is measured using DSC according to JIS-K7121.

  Specifically, the temperature is increased from 40 ° C. to 300 ° C. at a rate of 20 ° C./minute, held at 300 ° C. for 10 minutes, then cooled at a rate of 20 ° C./minute, held at 40 ° C. for 10 minutes, and further 20 The temperature is raised again at a rate of ° C / min, held at 300 ° C for 10 minutes, and then lowered to 40 ° C at a rate of 20 ° C / min. As described above, the temperature raising / lowering operation is repeated twice from 40 ° C. to 300 ° C., but the value of the temperature at the top of the crystallization peak at the time of the second temperature drop is measured and set as the crystallization temperature in the present invention.

  Specific examples of the substance used as the component (B) which lowers the crystallization temperature of the crystalline polyamide resin by 2 ° C. or more include other polyamide resins having different repeating units from the component (A), nigrosine, novolak phenol resin, Further, lithium halide has been confirmed, and any other substance that lowers the crystallization temperature of the component (A) by 2 ° C. or more can be used in the same manner.

  These substances may be used alone or in combination.

  The “polyamide resin having a different repeating unit from component (A)” used as component (B) is sufficient if it has a repeating unit different from component (A), regardless of whether it is amorphous or crystalline. . Specifically, any polyamide resin different from the component (A) can be selected from the polyamide resins exemplified in the specific examples of the component (A).

  Among them, when the component (A) is an aliphatic crystalline polyamide resin such as polyamide-6 or polyamide-66, an amorphous or crystalline semi-aromatic polyamide resin is used as the component (B). The effect of improving conductivity is large and preferable.

  Semi-aromatic polyamide resins include polyamide resins obtained by polycondensation of aliphatic dibasic acids and aromatic diamines, or aromatic dibasic acids and aliphatic diamines as raw materials. Specific examples of raw materials include aliphatic dibasic acids such as adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, hexadecanedioic acid, hexadecenedioic acid, eicosane Examples include diacid, eicosadiene diacid, diglycolic acid, 2,2,4-trimethyladipic acid, 1,4-cyclohexanedicarboxylic acid, and the like. Examples of aromatic diamines include metaxylylenediamine and paraxylylenediamine. Aromatic dibasic acids include terephthalic acid, isophthalic acid, phthalic acid and the like. Aliphatic diamines include hexamethylene diamine, tetramethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4 (or 2,4,4) -trimethylhexamethylene diamine, bis- ( 4,4′aminocyclohexyl) methane and the like.

  Among these semi-aromatic polyamide resins, in particular, polyamide resins synthesized based on terephthalic acid and / or isophthalic acid and hexamethylenediamine, that is, polyamide-6T, polyamide-6I, or copolymerized polyamide-6I / 6T, Further, a polyamide resin synthesized with metaxylylenediamine and / or paraxylylenediamine and adipic acid as main components is preferable because the effect of improving appearance is great in addition to the effect of improving conductivity. Copolymer polyamide-6I / 6T is particularly preferable.

  The preferred relative viscosity of the semi-aromatic polyamide resin used in the present invention is 1.5 to 4.0, preferably at a temperature of 23 ° C. in 98% sulfuric acid at a concentration of 1 wt% according to JIS-K6810. The range is from 1.8 to 3.0. If the relative viscosity is less than 1.5, the material strength is low, and if the relative viscosity exceeds 4.0, the fluidity is deteriorated.

  The compounding quantity of the semi-aromatic polyamide resin used by this invention is 1-30 weight part with respect to 100 weight part of component (A), Preferably it is 2-20 weight part, More preferably, it is 3-10. Parts by weight. If the blending amount is too small, the effect of improving the conductivity is small, and if it is too large, the heat-resistant rigidity is lowered and the releasability during molding is deteriorated.

  “Nigrosine” used as component (B) is COLOR INDEX and C.I. I. SOLVENT BLACK5 and C.I. I. It is a black azine condensation mixture such as triphenazine oxazine, phenazine azine compound, etc., as described in SOLVENT BLACK7.

Examples of commercially available nigrosine include Nubian Black EP-3, Nubian Black PA-9800 and Nubian Black PA0800 manufactured by Orient Chemical Industries. Among these, nubian black EP-3 is particularly preferable because of its great effect of improving conductivity.
The compounding amount of nigrosine used in the present invention is 0.05 to 30 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.1 to 100 parts by weight of the component (A). 1 to 2 parts by weight. If the blending amount is too small, the effect of improving the conductivity is small, and if it is too large, the thermal stability is deteriorated, the heat-resistant rigidity is lowered, the fluidity is lowered, the release property is lowered, etc., which is not preferable.

  "Novolak phenol resin" used as component (B) is a thermoplastic resin obtained by reacting excess phenol with formaldehyde using an acid as a catalyst, and does not contain a curing agent such as hexamethylenetetramine. It is. Novolac phenolic resin is preferable because of its great conductivity improvement effect, but within the range that does not impair the effect, a part of the phenol is converted into other phenols such as various cresols, xylenol, pt-butylphenol, p-phenylphenol, resorcinol. It can also be replaced.

  As a compounding quantity of the novolak phenol resin used by this invention, it is 0.05-30 weight part with respect to 100 weight part of component (A), Preferably it is 1-20 weight part, More preferably, it is 2 -10 parts by weight.

  If the blending amount is too small, the effect of improving the conductivity will be small, and if it is too large, there will be a decrease in heat-resistant rigidity, a decrease in impact strength, a decrease in tensile toughness, a decrease in releasability, etc., which is not preferred.

  Examples of the “lithium halide” used as the component (B) include lithium iodide, lithium chloride, and lithium bromide, and lithium chloride is preferable.

Lithium chloride is a substance represented by the chemical formula of LiCl, and is a white ionic crystalline powder. Melting point is 606 ° C., density is 2.07, and adjusted by adding hydrochloric acid to lithium carbonate. There are 1, 2, 3 and pentahydrates, which can be dehydrated by heating at 198 ° C. or higher to obtain anhydrides. In the present invention, either an anhydride or a hydrate of lithium chloride can be used, but an anhydride is preferred because it hardly causes appearance defects such as silver.
As a compounding quantity of the lithium chloride used by this invention, it is 0.05-30 weight part, Preferably it is 0.05-10 weight part, More preferably, it is 0.1-3 weight part.

  If the amount is less than this, the effect of improving the conductivity is small, and if the amount is too large, the heat-resistant rigidity is lowered, the releasability is lowered, and an appearance defect is liable to occur.

Component (C): Conductive carbon black having DBP oil absorption exceeding 150 ml / 100 g As the conductive carbon black having DBP oil absorption exceeding 150 ml / 100 g used in the present invention as component (C), for example, acetylene gas Acetylene black obtained by thermal decomposition of ketene black and ketjen black produced by furnace type incomplete combustion. In particular, ketjen black can be preferably used because of its excellent conductivity.

  In addition, "DBP oil absorption" in this invention shows the dibutyl phthalate oil absorption measured based on ASTM-D2414. Carbon black with higher oil absorption exhibits higher conductivity.

  In addition to the DBP oil absorption rate, the BET specific surface area measured by the nitrogen gas adsorption method is one of the indexes for determining the conductivity of carbon black, and a carbon black having a higher BET specific surface area is preferable because it is excellent in conductivity.

Preferred as component (C) in the present invention is carbon black having a DBP oil absorption of more than 150 ml / 100 g and a BET specific surface area of more than 100 m ² / g. Particularly preferred is ketjen black having a DBP oil absorption exceeding 400 ml / 100 g and a specific surface area exceeding 1000 m ² / g.

  The compounding quantity of the component (C) used by this invention is 2-30 weight part with respect to 100 weight part of component (A), Preferably, it is 3-20 weight part, More preferably, 4- 10 parts by weight.

  If the blending amount of the conductive carbon black is too large, the appearance, fluidity, impact resistance and the like deteriorate, which is not preferable. If the blending amount is too small, the effect of improving the conductivity is small and not preferable.

  Various other additives and thermoplastic resins can be blended in the conductive polyamide resin composition according to the present invention within a range that does not impair the objects and effects of the present invention.

  For example, colorants such as iron oxide, titanium oxide, perinone dyes, heat stabilizers such as phosphites, hindered phenols, copper compounds, glass fibers, talc, mica, kaolin, wollastonite, titanium oxide, various layered forms Reinforcing agents such as silicates, conductivity improvers such as carbon fibers, metal fibers and metal powders, release agents such as metal salts of higher fatty acids and higher fatty acid amides, paintability improving agents such as epoxy compounds and ethylene vinyl alcohol Flame retardants such as melamine cyanurate, melamine polyphosphate, phosphazene, red phosphorus, Br-polystyrene, flame retardant aids such as antimony trioxide and zinc borate, EBR (ethylene butene copolymer) modified with unsaturated dicarboxylic acid ), Unsaturated dicarboxylic acid modified EPR (ethylene-propylene copolymer), unsaturated dicarboxylic acid modified SEBS (styrene Improving impact resistance of SEM (styrene / ethylene propylene / styrene copolymer) modified with unsaturated dicarboxylic acid, ABS (acrylonitrile / butadiene / styrene copolymer) modified with unsaturated dicarboxylic acid, etc. Functional groups such as PP (polypropylene) modified with an agent, unsaturated dicarboxylic acid, PPE (polyphenylene ether) modified with unsaturated dicarboxylic acid, PS (polystyrene) modified or copolymerized with unsaturated dicarboxylic acid, amino, carboxyl group, etc. Other thermoplastic resins such as added AS (acrylonitrile / styrene copolymer) can be mentioned.

  In particular, a composition in which talc and / or wollastonite as an inorganic filler and ethylene / butene-1 copolymer as an impact resistance improver are used in combination are rigid, dimensional stability, impact resistance, electrical conductivity, flow It can be preferably used as a resin composition having an excellent balance of properties.

  The compounding of the resin composition in the present invention is carried out at any stage from resin production to molding. Preferably, the component (A) + (B) + (C) is melt-kneaded at the same time by an extruder, or the component (A) (B) is melt-kneaded, and then the component (C) is added and melt-kneaded. is there.

  In addition to components (A), (B) and (C), when other thermoplastic resins such as impact resistance improvers and inorganic fillers are blended, components (A), (B) and other It is preferable to melt-knead the thermoplastic resin and then melt-knead the component (C) and the inorganic filler.

  By this method, since the component (C) can be dispersed in the component (A) and / or the component (B) without being dispersed in other thermoplastic resins, the resin has excellent conductivity and mechanical properties. A composition can be obtained, which is preferable.

  Usually, a pellet is once produced from the above blended composition, and the pellet is molded into an arbitrary shape by compression molding, injection molding, extrusion molding or the like and used as a desired resin product.

  The resin composition of the present invention is, for example, a gasoline cap, an engine cover, an outer panel of an automobile, a casing of an electric / electronic component such as a personal computer, a mobile phone, etc. Etc. can be suitably used.

  The conductive polyamide resin composition of the present invention is excellent in mechanical strength such as conductivity, fluidity, impact strength, rigidity, etc., and housings such as electric / electronic and automobile parts, structural members, exterior members, connectors, etc. The industrial utility value is extremely high.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples. In the examples and comparative examples, the compounding amount means parts by weight.
(1) Details of each component in the blending examples are as follows.
Component (A): Crystalline polyamide resin (A-1): Polyamide-6: Relative viscosity measured by Mitsubishi Engineering Plastics, trade name Novamid 1010J, temperature 23 ° C., 98% sulfuric acid at 1 wt% concentration 5. Melting point: 223 ° C
(A-2): Polyamide-66: manufactured by DuPont, trade name Zytel FE3218, temperature 23 ° C., relative viscosity 2.8 measured at 1 wt% concentration in 98% sulfuric acid, melting point 263 ° C.
Ingredient (B): Substance that lowers the crystallization temperature of ingredient (A) by 2 ° C. or more (B-1): Novolak phenolic resin: Sumitomo Durez, trade name Sumilite Resin PR53195, softening temperature 110 ° C., number average molecular weight 830, free phenol content <1%
(B-2): Nigrosine: manufactured by Orient Chemical Co., Ltd., trade name Nubian Black EP-3, melting point> 300 ° C.
(B-3): Lithium chloride: Merck's product name, lithium chloride. Purity> 99%
(B-4): Copolymer polyamide-6I / 6T (semi-aromatic, amorphous polyamide resin): Mitsubishi Engineering Plastics, trade name Novamid X21F07, temperature 23 ° C., 98% sulfuric acid at 1 wt% concentration Measured relative viscosity 2.1, no melting point (B-5): MXD6 (semi-aromatic, crystalline polyamide) obtained by polycondensation of metaxylylenediamine and adipic acid: trade name Reny 6002, manufactured by Mitsubishi Engineering Plastics Melting point 242 ° C., temperature 23 ° C., relative viscosity 2.14 measured in 98% sulfuric acid at 1 wt% concentration

(B-6): Polyamide-6: manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name Novamid 1007J, temperature 23 ° C., 98% sulfuric acid, relative viscosity 2.2 measured at 1 wt% concentration

Ingredient (C): Conductive carbon black with DBP oil absorption exceeding 150 ml / 100 g (C-1) Ketjen black: Lion Corporation, trade name Ketjen 600JD, DBP oil absorption 495 ml / 100 g, specific surface area 1270 m ² / g
(D) Other components (D-1) Talc (magnesium silicate): Hayashi Kasei Co., Ltd., trade name HST0.5, average particle system 2.75 μm
(D-2) Maleic anhydride-modified ethylene / butene copolymer: manufactured by Mitsubishi Chemical Corporation, trade name AP730T, density = 0.89 MFI = 2 g / 10 min (measured at ASTM 1238-190 ° C.), surface hardness 83 (JIS) -K6301-A)
(D-3) Bis (2,6-di-tbutyl-4-methylphenyl) pentaerythritol diphosphite: Asahi Denka Co., Ltd., trade name PEP36, melting point 234-240 ° C. It has a function as a heat stabilizer of polyamide resin and a function to improve heat-resistant rigidity.
(D-4) Maleic anhydride-modified PPE resin: 1% maleic anhydride was melt-kneaded with 100% by weight of PPE resin having an intrinsic viscosity of 0.46 (measured in chloroform at 30 ° C.) manufactured by Mitsubishi Gas Chemical Company, Inc. PPE resin.

  Regarding the effect of lowering the crystallization temperature of component (A) by component (B), the results of crystallization temperature measurement of various formulations are shown in Table 1 as reference examples.

The sample preparation method and measurement conditions used for the measurement are as follows.
1) Preparation method of crystallization temperature measurement sample Weighed so as to have the composition shown in Table 1 below, mixed with a tumbler mixer, and then used a twin screw extruder TEX-30XCT (caliber 30 mmφ) manufactured by Nippon Steel Works. Then, a pellet was prepared by melt-kneading under the following conditions. The pellet was dried at 120 ° C. for 5 hours, and then used as a crystallization temperature measurement sample.

・ Cylinder setting temperature = melting point + 20 ℃
(When component (A) is polyamide-6, 242 ° C.,
(When polyamide-66 or polyamide-66 rich, it was 283 ° C.)
・ Screw rotation speed = 200rpm
・ Discharge rate = 15kg / h
2) Crystallization temperature measurement method The crystallization temperature was measured using DSC [PYRIS-DIAMOND] manufactured by PerkinElmer according to JIS-K7121.

  The sample is precisely weighed 8 mg, heated from 40 ° C to 300 ° C at a rate of 20 ° C / minute, held at 300 ° C for 10 minutes, then cooled down at a rate of 20 ° C / minute, and held at 40 ° C for 10 minutes. Further, the temperature is raised again at a rate of 20 ° C./minute, held at 300 ° C. for 10 minutes, and then lowered to 40 ° C. at a rate of 20 ° C./minute.

  As described above, the temperature raising and lowering operation was repeated twice from 40 ° C. to 300 ° C., but the temperature value at the top of the crystallization peak at the time of the second temperature drop was measured and used as the crystallization temperature.

参考例の結晶化温度測定結果
表１に示す通り、各種の成分（Ｂ）の配合により成分（Ａ）単独配合より結晶化温度が低下していることが分かる。一方、成分（Ｄ−２）（Ｄ−４）では結晶化温度は変わらないことが分かる。

As shown in Table 1, the crystallization temperature measurement result of the reference example shows that the crystallization temperature is lower than that of the component (A) alone by the combination of the various components (B). On the other hand, it turns out that a crystallization temperature does not change with a component (D-2) (D-4).

Next, the manufacturing method of the resin composition in the Example regarding this invention and a comparative example is demonstrated.
3) Example 1-10, Comparative Example 1-6
Ingredients (A), (B), (C) and other ingredients (D) were blended in the proportions shown in Tables 2 and 3 and mixed with a tumbler mixer, and a twin-screw extruder TEX made by Nippon Steel Works The mixture was supplied to -30XCT and melt-kneaded at a cylinder temperature of 280 ° C, a screw speed of 300 rpm, and a discharge rate of 15 kg / h to obtain pellets of each composition. The obtained pellet was dried with hot air at 120 ° C. for 8 hours to obtain a molding material.

  In Examples 1-5, 9-10, and Comparative Examples 1 and 6, which are compositions consisting only of components (A), (B), and (C), all components are batched. Blended and melt kneaded.

  On the other hand, in Example 6-7 and Comparative Example 2-4, after components (A), (B), and (C) were melt-kneaded, components (D-1), (D-2), and (D-4) ) And melt-kneaded again.

In Example 8 and Comparative Example 5, which are compositions in which components (D-1), (D-2), and (D-3) are blended simultaneously, components (A), (B), (C), and (D- 3) was blended and melt-kneaded at the same time, then (D-1) was blended, melt-kneaded again, then (D-2) was blended again, and melt-kneaded again to obtain pellets of each composition.
4) Preparation method of physical property test pieces Using a J75ED injection molding machine manufactured by Nippon Steel Works, various physical property test piece molds were injection molded to prepare various test pieces.
The molding conditions were a cylinder temperature of 280 ° C., a mold temperature of 80 ° C., an injection time of 15 seconds, and a cooling time of 30 seconds.

5) Tensile properties Tensile tests were conducted according to ASTM-D638.
6) Bending properties The bending test was conducted according to ASTM-D790.

In addition, the bending displacement amount described the displacement amount until fracture.
It shows that it is excellent in rigidity, so that a bending elastic modulus is large, and it is excellent in toughness, so that a bending displacement amount is large.

7) Impact properties An IZOD impact test was conducted according to ASTM-D256.
It shows that it is excellent in impact resistance, so that a numerical value is large.

8) Fluidity When a test piece having a thickness of 100 mm × 100 mm × 3 mm was injection-molded, it was evaluated by an injection pressure (necessary filling pressure) required to fully fill the mold.

Except for the injection pressure, it was performed under the same conditions without changing depending on the material.
Molding machine = “J75ED” manufactured by Nippon Steel Works
Cylinder temperature = 280 ° C., mold temperature = 80 ° C., injection speed = 99%, injection time = 10 seconds, cooling time = 15 seconds. The smaller the required filling pressure value, the better the fluidity.

9) Conductivity Evaluated by measuring volume resistivity.

  The sample is cut into strips of 5 cm in length, 1.27 cm in width, and 0.32 cm in thickness by cutting off both ends of the tensile test piece in 4) described above. Next, a silver paste was applied to the cut-off both end faces, air-dried at 23 ° C. for 30 minutes, the resistance value was measured with a tester, and the volume resistivity was determined by the following calculation formula.

Volume resistivity {Ωcm} = (measured resistance value {Ω}) × (cross-sectional area of test = 1.27 × 3.2 {cm ² }) / (length of test piece = 5 {cm})
It shows that it is excellent in electroconductivity, so that this figure is low.

実施例、比較例の各種物性評価結果
表２，３に示す、配合組成及び物性評価結果について、説明を補足する。
（１）比較例１と、比較例１の組成物に成分（Ｂ）を配合しただけの実施例１，２，３，４，５とを比較すると、実施例１，２，３，４，５は導電性以外の品質を損なうことなく、導電性が著しく高められていることが分かる。
（２）比較例１と、比較例１の組成物に成分（Ｄ−４）を配合しただけの比較例２を比較すると、成分（Ａ−１）と相溶性の無い成分（Ｄ−４）を配合しただけでは、導電性の改良効果は小さいことが分かる。
（３）比較例３と、比較例３の組成物に成分（Ｂ）を配合しただけの実施例６を比較すると、実施例６は導電性以外の品質を損なうことなく、導電性が著しく高められていることが分かる。

Various physical property evaluation results of Examples and Comparative Examples Supplementary explanations are given for the blending compositions and physical property evaluation results shown in Tables 2 and 3.
(1) Comparing Comparative Example 1 with Examples 1, 2, 3, 4, and 5 in which component (B) was simply blended with the composition of Comparative Example 1, Examples 1, 2, 3, 4, and 5 5 shows that the conductivity is remarkably improved without deteriorating the quality other than the conductivity.
(2) Comparing Comparative Example 1 with Comparative Example 2 in which the component (D-4) was added to the composition of Comparative Example 1, the component (D-4) having no compatibility with the component (A-1) It can be seen that the effect of improving the conductivity is small simply by blending.
(3) Comparing Comparative Example 3 with Example 6 in which the component (B) was simply blended with the composition of Comparative Example 3, Example 6 significantly increased conductivity without degrading quality other than conductivity. You can see that

Moreover, it turns out that Example 6 which mix | blended the component (D-1) with respect to Example 1 has an effect which remarkably improves rigidity, although fluidity | liquidity and toughness fall (4) Comparative example 4 and a comparative example When Example 7 which only mix | blended the component (B) with the composition of 4 was compared, it turns out that Example 7 has improved electroconductivity remarkably, without impairing quality other than electroconductivity.

Moreover, it turns out that Example 7 which mix | blended component (D-2) with respect to Example 1 has the effect of improving a toughness remarkably, although fluidity | liquidity and rigidity fall.
(5) Comparing Comparative Example 5 with Example 8 in which (B) was blended with the composition component of Comparative Example 5, Example 8 had a quality other than conductivity (six quality of display excluding IZOD) . It can be seen that the conductivity is remarkably enhanced without loss.

Moreover, it turns out that the balance of rigidity and toughness is improving by mix | blending a component (D-1), (D-2), and (D-3) with respect to Example 1. FIG.
(6) Comparing Comparative Example 6 and Examples 9 and 10 in which the composition of Comparative Example 6 was simply blended with component (B), Examples 9 and 10 were remarkably not impaired in quality other than conductivity. It can be seen that the conductivity is increased.

Claims (6)

Component (A): 100 parts by weight of crystalline polyamide resin,
Component (B): 0.05 to 10 parts by weight of a substance that lowers the crystallization temperature of component (A) by 2 ° C. or more and Component (C): 2 to 30 weights of conductive carbon black with DBP oil absorption exceeding 150 ml / 100 g Part of the polyamide resin composition, wherein the component (B) is a semi-aromatic polyamide resin, and the conductivity represented by the volume resistivity of the molded article comprising the composition is 2 to 9 × 10 ⁴ conductive polyamide resin composition characterized by Ωcm Ru der.   The component (A) is a polyamide comprising ε-caprolactam as a main structural unit and / or a polyamide comprising an aliphatic diamine having 6 carbon atoms and an aliphatic dicarboxylic acid having 6 carbon atoms. The conductive polyamide resin composition described in 1.   2. The conductive polyamide resin composition according to claim 1, wherein the component (A) is polyamide-6, polyamide-66, or a copolymer of polyamide-6 and polyamide-66.   The conductive polyamide resin composition according to any one of claims 1 to 3, wherein the component (B) is a semi-aromatic polyamide resin composed of terephthalic acid, isophthalic acid, and hexamethylenediamine. Component (C) is a conductive polyamide resin composition according to any one of claims 1-4, characterized in that the Ketjen black. Component (A) is polyamide-6, Component (B) is a semi-aromatic polyamide resin composed of terephthalic acid and isophthalic acid and hexamethylenediamine, and Component (C) is ketjen black The conductive polyamide resin composition according to claim 1 .