KR20130113118A - A composition of electrically conductive resin - Google Patents

Abstract

PURPOSE: A resin composition with improved electric conductivity improves electric conductivity while having excellent heat resistance, dimensional stability, oil resistance, and molding processability. CONSTITUTION: A resin composition with improved electric conductivity includes a polyphenylene ether-based resin, a polyamide-based resin, and a carbon-based conductive material. The weight ratio of the polyphenylene ether-based resin and the polyamide-based resin is 1 or less. The melt index of the polyamide resin (275°C, 5kg) is 50-200. The content of the carbon-based conductive material is 0.1-20 parts by weight per 100.0 parts by weight of the mixture of the polyphenylene ether resin and polyamide-based resin. The carbon-based conductive material is carbon nanotubes.

Description

Electrically Conductive Resin Composition {A Composition of Electrically Conductive Resin}

The present invention relates to an electrical conductivity improving resin composition using selective dispersion of carbon nanotubes.

In general, polyphenylene ether (PPE or PPO) resin is widely used in various fields of the industry, such as automotive parts, electrical, electronic parts because of excellent mechanical and electrical properties. However, molded articles made of polyphenylene ether resins have excellent dimensional stability due to their excellent impact strength, tensile strength, and heat resistance, but polyphenylene ether resins are difficult to process alone and are used as polyamide resins and composite materials having good compatibility. The composite material is excellent in heat resistance and oil resistance and is mainly used for exterior plates for light weight in the automotive industry. Sheet extrusion and vacuum molding have been developed for applications other than injection molding, and since the difference in physical properties appears depending on the molecular weight of each component and the formulation of the elastomer, it is necessary to develop a formulation having optimized properties for the application.

As such a conductive polyphenylene ether / polyamide composite material, Korean Patent No. 10-0262771 discloses a thermoplastic composition consisting of a polyphenylene ether / polyamide base resin and conductive carbon black, but with the addition of conductive wire carbon black Due to the drawback that the impact strength drops sharply, there is a problem that can not be applied to automotive exterior panels, etc., Republic of Korea Patent No. 10-0792783 polyphenylene ether resin, unsaturated carboxylic acid or anhydride group graft polyphenyl An electrically conductive polyphenylene ether / polyamide-based thermoplastic resin composition containing a ethylene ether resin, a polyamide resin and an acid treated carbon nanotube is disclosed, but an unsaturated carboxylic acid or anhydride group graft polyphenylene ether resin and It takes a lot of time and resources to produce acid treated carbon nanotubes. The present nanotube acid treatment when the electrical conductivity has the disadvantage that the electrical conductivity falls. U.S. Patent No. 3,379,792 discloses resin compositions in which 0.01 to 25% by weight of polyamide resins are contained in polyphenylene ether resins. However, in this case, when the content of the polyamide resin is 20% by weight or more, the compatibility between the polyphenylene ether and the polyamide is poor, resulting in phase separation, and as a result, the physical properties of the molded article have a significant decrease. U. S. Patent No. 5,843, 340 discloses citric acid as a reactive material to increase the compatibility of polyphenylene ether resins with polyamide resins.

Conventional electroconductive plastics have been commercialized such that most of the products simply disperse one type of electroconductive filler in a matrix or utilize inherent conductive polymers such as polyaniline. In particular, when the conductive filler is used, a large amount of filler can be used to obtain the desired electrical conductivity, and when carbon fiber is used, the product surface appearance is not good, and when carbon black is used, carbon black may be buried on the surface. . In addition, the use of metal fibers had a problem of abrasion of the molding machine as well as the external appearance of the surface of the metal fiber had a lot of restrictions to expand the market.

On the other hand, in the case of electrically conductive nanocomposites using carbon nanotubes and carbon nanofibers manufactured through nanotechnology, appearance problems can be solved, and even small amounts of carbon nanotubes and carbon nanofibers can secure desired electrical conductivity. This solved the problem of carbon-based material on the surface. However, since carbon nanotubes and carbon nanofibers are at least three times more expensive than conductive carbon black, it is difficult to secure the marketability of carbon nanotubes and carbon nanofiber polymer composite materials.

Korea Patent Registration No. 10-0262771 (2000.05.06) Korea Patent Registration No. 10-0792783 (2008.01.02)

The present invention has been made in order to solve the above problems, and excellent electrical properties, such as heat resistance, dimensional stability, oil resistance, molding processability, and at the same time excellent electrical conductivity improved resin composition and manufactured therefrom The purpose is to provide a molded article.

It is also an object of the present invention to selectively disperse a small amount of conductive material to significantly improve the electrical conductivity, thereby providing an economical electrical conductivity improving resin composition and a molded article produced therefrom.

The electrically conductive improvement resin composition according to the present invention is a composition comprising a polyphenylene ether resin, a polyamide resin and a carbon conductive material, wherein the polyphenylene ether resin (A) and polyamide resin (B) The weight ratio (A / B) is 1 or less, characterized in that the melt index (MVR, 275 ℃, 5kg) of the polyamide-based resin is 50 to 200.

In this case, the carbon-based conductive material is contained 0.1 to 20 parts by weight based on 100 parts by weight of the mixture of the polyphenylene ether resin and polyamide resin.

In the present invention, the carbon-based conductive material includes a multi-walled carbon nanotube having a diameter of 5 to 50 nm and a surface area of 150 to 500 m ² / g.

The polyphenylene ether resin may be poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-di Propyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene ) Copolymer of poly (2,3,6-trimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6- At least one selected from the group consisting of copolymers of triethyl-1,4-phenylene) ether and combinations thereof.

The polyamide-based resin may be polycaprolactam, polyhexamethylene adipamide, poly (11-aminoundecanoic acid), polylauryllactam, polyhexamethylene dodecanodiamide, poly (2-pyrrolidone), Polyhexamethylene terephthalamide, polytetramethylene terephthalamide, and copolymers thereof.

In the present invention, the composition is styrene / butadiene / styrene block copolymer, styrene / ethylene / butylene / styrene block copolymer, styrene / ethylene / propylene / styrene block copolymer, styrene / butadiene / butylene / styrene block copolymer, And at least one polystyrene-diene copolymer selected from styrene / ethylene / propylene block copolymers, styrene / ethylene / butylene block copolymers, and styrene / butadiene / butylene copolymers.

The composition further comprises at least one filler selected from glass fibers, carbon fibers, metal fibers, aramid fibers, whiskers, talc, mica, silicates, quartz, titanium dioxide and mixtures thereof.

The present invention provides a molded article prepared from the composition. In this case, the molded article is characterized in that the surface resistance of 1.0E + 01 to 1.0E + 10 Ω / sq.

The electrical conductivity-improving resin composition according to the present invention has an advantage of excellent mechanical properties such as heat resistance, dimensional stability, oil resistance, molding processability, and at the same time, excellent electrical conductivity. In addition, the electrical conductivity improving resin composition of the present invention is economical because it can significantly increase the electrical conductivity even if it contains a small amount of conductive material, it is possible to further expand the application range of the molded article produced using the composition.

1 shows a transmission electron microscope (TEM) low magnification photograph in which carbon nanotubes are selectively dispersed in a polyamide resin.
2 shows a transmission electron microscope (TEM) high magnification photograph of carbon nanotubes selectively dispersed in a polyamide resin.
FIG. 3 shows the dispersion and electrical conductivity of carbon nanotubes according to the conditions of the weight ratio (A / B) of the polyphenylene ether resin (A) and the polyamide resin (B) and the melt index (MVR) of the polyamide resin. It is illustrated.

Hereinafter, with reference to the accompanying drawings will be described in detail the electrical conductivity improving resin composition of the present invention. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the following drawings may be exaggerated in order to clarify the spirit of the present invention. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

Applicant has deepened the research on the electrically conductive polyphenylene ether / polyamide composite material, and surprisingly, the carbon nanotubes were controlled by controlling the melt flow rate of the polyamide as well as the mixing weight ratio of the polyphenylene ether and the polyamide resin. It has been found that the electrical conductivity can be dramatically improved according to the selective dispersion, and the present invention has been filed.

The electrically conductive improvement resin composition according to the present invention is a composition comprising a polyphenylene ether resin, a polyamide resin and a carbon conductive material, wherein the polyphenylene ether resin (A) and polyamide resin (B) The weight ratio (A / B) is 1 or less, characterized in that the melt index (MVR, 275 ℃, 5kg) of the polyamide-based resin is 50 to 200.

In the present invention, the weight ratio (A / B) of the polyphenylene ether resin (A) and the polyamide resin (B) is 1 or less, and preferably 0.3 to 0.8. Outside the above range, the polyamide-based resin in which carbon nanotubes are selectively dispersed forms domains other than the matrix, thereby reducing electrical conductivity.

The carbon-based conductive material is characterized in that the carbon nanotubes, and includes any one or more selected from the group consisting of single-walled carbon nanotubes, double-walled carbon nanotubes, thin multi-walled carbon nanotubes and multi-walled carbon nanotubes. More preferably, the carbon nanotubes may be multi-walled carbon nanotubes having a diameter of 5 to 50 nm and a surface area of 150 to 500 m ² / g.

In this case, the carbon-based conductive material is characterized in that 0.1 to 20 parts by weight based on 100 parts by weight of the mixture of polyphenylene ether resin and polyamide resin. If the content of the carbon-based conductive material is less than 0.1 weight ratio, the effect of improving the electrical conductivity is not seen, and if it is more than 20 parts by weight, economic efficiency is poor.

In the present invention, the polyphenylene ether resin may be poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6) -Dipropyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether , Poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4- Copolymer of phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3, At least one selected from the group consisting of copolymers of 6-triethyl-1,4-phenylene) ether and combinations thereof.

In another embodiment of the present invention, the polyphenylene ether resin includes a polyphenylene ether resin alone or a modified polyphenylene ether resin containing a polyphenylene ether resin, a vinyl aromatic polymer and the like. The modified polyphenylene ether resin may be used 10 to 300 parts by weight, more preferably 25 to 150 parts by weight of the vinyl aromatic polymer with respect to 100 parts by weight of polyphenylene ether resin. When the vinyl aromatic polymer is less than 10 parts by weight, it is disadvantageous in terms of fluidity reduction, and when it is more than 300 parts by weight, it is difficult to exhibit sufficient mechanical properties as a polyphenylene ether resin.

The vinyl aromatic polymer may include, as a main component, a conventional polystyrene resin, an impact resistant polystyrene resin, or a mixture thereof. As a non-limiting example of the vinyl aromatic polymer, at least one compound selected from the group consisting of polystyrene, high impact polystyrene, acrylonitrile / butadiene / styrene copolymer, polychlorostyrene, poly alpha-methylstyrene and polytetra-butyl styrene Can be used. More preferably, polystyrene or high impact polystyrene may be used alone or in combination.

Polyamide resins in the present invention include, but are not limited to, polycaprolactam (polyamide 6), polyhexamethylene adipamide (polyamide 66), poly (11-aminoundecanoic acid) (polyamide 11), Polylauryllactam (polyamide 12), polyhexamethylene dodecanodiamide (polyamide 6,9), poly (2-pyrrolidone) (polyamide 4), polyhexamethylene terephthalamide (polyamide 6T), Polytetramethylene terephthalamide (polyamide 4T) and the like and polyamides such as polyamide 4/6, polyamide 6 / 6,6, polyamide 6 / 6,10, and polyamide 6/12, which are copolymers thereof. It is also possible to use a mixture of two or more kinds. Preference is given to using polyamide 6, polyamide 66 or mixtures thereof. The polyamide resin is preferably used 30 to 500 parts by weight based on 100 parts by weight of the polyphenylene ether resin.

In particular, in the present invention, it is necessary to control the melting flow of the polyimide for the selective dispersion of the carbon-based conductive material. At this time, the melt index (MVR, 275 ℃, 5kg) of the polyamide-based resin is characterized in that 50 to 200. If the melt index is less than 50, carbon nanotubes are not selectively dispersed in the polyamide-based resin, and if it is more than 200, mechanical properties of the molded article are drastically reduced.

The composition according to the invention is a styrene / butadiene / styrene block copolymer, styrene / ethylene / butylene / styrene block copolymer, styrene / ethylene / propylene / styrene block copolymer, styrene / butadiene / butylene / styrene block copolymer, One or more polystyrene-diene copolymers selected from styrene / ethylene / propylene block copolymers, styrene / ethylene / butylene block copolymers, and styrene / butadiene / butylene copolymers may be further included. At this time, the content of the copolymer is preferably 5 to 30 parts by weight based on 100 parts by weight of the mixture of polyphenylene ether resin and polyamide resin, the impact characteristics and strength is reduced outside the above range.

In another embodiment of the present invention, the copolymer may be a polystyrene-diene copolymer in which an unsaturated carboxylic acid or an anhydride group is grafted, thereby improving compatibility and physical properties between components. Preferably grafted maleic anhydride to a polystyrene-diene block copolymer, more preferably hydrogenated styrene / butadiene / styrene block copolymer (styrene / Ethylene / butylene / styrene block copolymer) is preferably used. At this time, as a monomer which has an unsaturated carboxylic acid or its anhydride group, maleic anhydride, maleic acid, itaconic anhydride, fumaric acid, acrylic acid, methacrylic acid ester, or a mixture of 2 or more types can be used.

The present invention may further include any one or more fillers selected from glass fibers, metal fibers, whiskers, talc, mica, silicates, quartz, titanium dioxide, and mixtures thereof. At this time, the content of the filler is preferably 10 to 30 parts by weight based on 100 parts by weight of the mixture of polyphenylene ether resin and polyamide resin, the mechanical properties are poor or poor workability outside the above range.

The present invention can provide a molded article prepared by including the composition.

The molded article is characterized in that the surface resistance by the ASTM evaluation method D257 is 1.0E + 10 Ω / sq or less.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. Various modifications and variations are possible in light of the above teachings.

(Examples 1 and 2)

The compositions for the various components used in the examples of the present invention are shown in Table 1 below. Polyphenylene ether (PPE) was used by Mitsubishi Chemical, Yupiace PX-100F, polyamide resin was used polyamide 66 (PA66), melt index (MVR, cc / 10min, 275 ℃, 5kg, ISO 1133) PA66 (name: A3K) having 115) was used. Carbon nanotubes (CNT) were used as multi-walled carbon nanotubes (Nanocy, NC7000, average diameter 9.5nm, average length 1.5㎛, surface area 250 ~ 300m ² / g).

The composition ratios shown in Table 1 were titrated and mixed, and the compositions were made using a twin screw extruder having a length-to-diameter ratio (L / D) of 40, and then test specimens were made through an injection machine. At this time, the extrusion conditions were the screw speed of 300rpm, temperature 270 ~ 320 ℃, injection conditions were injection temperature 280 ~ 300 ℃, mold temperature 60 ~ 70 ℃.

(Example 3)

Test specimens were prepared in the same manner as in Example 1, except that GF (Chopped glass fiber, Owens Corning, 123D) and styrene ethylene butylene styrene (SEBS, Kraton, FG1901X) were used. Prepared.

(Comparative Example 1)

A test specimen was prepared in the same manner as in Example 1 except that the composition ratios shown in Table 1 were titrated and mixed, but the mixing weight ratio of the polyphenylene ether resin and the polyamide resin was changed.

(Comparative Example 2)

The composition ratios shown in Table 1 below were appropriately mixed, but A3K was used as polyamide 66, and the melt index (MVR, cc / 10 min, 275 ° C., 5 kg, ISO 1133) was changed to PA66 (name: A4H) having 40. Test specimens were prepared in the same manner as in Example 1 except that.

Examples 1 to 3 use PA66 [A3K] with a melt index (MVR) of 115, but when the PPE / PA66 ratio is 1 or less, the flow of A3K is high and the relative content is high so that PA66 forms a matrix. do. In addition, since carbon nanotubes (CNTs) are dispersed in PA66 which is much more flowable than PPE having little flowability, as shown in FIGS. 1 and 2, it can be seen that CNTs selectively disperse in PA66. .

Therefore, as shown in FIG. 3, since the CNTs are not dispersed in the PPE domain, the concentration of CNTs dispersed only in the PA66 matrix becomes relatively high. Therefore, in Examples 1 and 2, while the content of CNT is constant, the content of PPE is high and the content of PA66 is low, so that the relative content of CNT in the PA66 matrix is high, so that Example 2 has higher electrical conductivity (lower surface) than Example 1. Resistance). In addition, these results appeared unchanged even if the glass fiber or the impact modifier SEBS further included.

As shown in Figure 3, Comparative Example 1 (weight ratio (A / B)> 1 of PPE / PA66> 1) has a very high PPE content, form a matrix and good flowability PA66 forms a domain so that CNT is PA66 domain It can be seen that a relatively large number, and some CNTs that do not enter the PA66 domain is dispersed in the PPE matrix, it can be seen that the surface resistance is relatively high (Fig. 3 (c)). In addition, in Comparative Example 2 (weight ratio (A / B) ≤ 1 of PPE / PA66 ≤ 1, MVR (PA) <50) using a low flowability PA66 instead of a good flowability PA66, the viscosity difference between PPE and PA66 is reduced As the CNT is dispersed in not only PA66 but also PPE, the surface resistance is relatively higher than that of Example 1 (Fig. 3 (b)). That is, in the present invention, in order to increase the electrical conductivity by lowering the surface resistance through selective dispersion of CNTs, a resin having good flowability is selected as the matrix resin, and the electrical conductivity is significantly increased by increasing the viscosity difference with the resin forming the domain. It could be improved (FIG. 3 (a)).

While the present invention has been described in detail with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. All of which fall within the scope of the present invention.

Claims (10)

A composition comprising polyphenylene ether resin, polyamide resin, and carbon conductive material, wherein the weight ratio (A / B) of the polyphenylene ether resin (A) and polyamide resin (B) is 1 or less Wherein the melt index (MVR, 275 ° C., 5 kg) of the polyamide-based resin is 50 to 200.
The method of claim 1,
The carbon-based conductive material is an electrical conductivity improving resin composition containing 0.1 to 20 parts by weight based on 100 parts by weight of a mixture of polyphenylene ether resin and polyamide resin.
The method of claim 1,
The carbon-based conductive material is an electrically conductive improvement resin composition, characterized in that the carbon nanotubes.
The method of claim 3, wherein
The carbon nanotubes are 5 to 50 nm in diameter, the surface conductivity is 150 to 500 m ² / g electrical conductivity enhancement resin composition comprising a multi-walled carbon nanotubes.
The method of claim 1,
The polyphenylene ether resin may be poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-di Propyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene ) Copolymer of poly (2,3,6-trimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6- An electroconductivity improving resin composition which is at least one selected from the group consisting of a copolymer of triethyl-1,4-phenylene) ether and a combination thereof.
The method of claim 1,
The polyamide-based resin may be polycaprolactam, polyhexamethylene adipamide, poly (11-aminoundecanoic acid), polylauryllactam, polyhexamethylene dodecanodiamide, poly (2-pyrrolidone), The electrical conductivity improvement resin composition which is any one or more selected from polyhexamethylene terephthalamide, polytetramethylene terephthalamide, and a copolymer thereof.
The method of claim 1,
The composition includes styrene / butadiene / styrene block copolymer, styrene / ethylene / butylene / styrene block copolymer, styrene / ethylene / propylene / styrene block copolymer, styrene / butadiene / butylene / styrene block copolymer, styrene / ethylene An electrically conductive improvement resin composition further comprising any one or more polystyrene-diene copolymers selected from / propylene block copolymers, styrene / ethylene / butylene block copolymers, and styrene / butadiene / butylene copolymers.
The method of claim 1,
The composition may further include at least one filler selected from glass fibers, metal fibers, whiskers, talc, mica, silicates, quartz, titanium dioxide, and mixtures thereof.
The molded article containing the resin composition of any one of Claims 1-8.
The method of claim 9,
The molded article is a molded article, characterized in that the surface resistance by the ASTM evaluation method D257 is 1.0E + 10 Ω / sq or less.

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