JP2005171183A - Conductive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive resin composition that generates only little volatile components in a molding process and whose mechanical property and high dispersibility of carbon black in not spoiled. <P>SOLUTION: The conductive resin composition comprises a polyalkylene phthalate resin, carbon black, a hindered phenol-based antioxidant, a metal inactivating agent, and preferably at least either of a polycarbonate resin or polyarylate resin. Use of the conductive resin composition reduces an amount of a volatile composition generated in a process of molding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a conductive resin composition that has a small amount of volatile components generated during molding and is suitable as a member for electric / electronic parts.

  In general, a resin composition containing plastics or the like has a large electric resistance and is used as an insulating material. However, the resin composition contains a conductive material such as metal fine powder or carbon black in such a resin composition. There is known a conductive resin composition imparted with conductivity. In particular, as the conductive material, carbon black is preferably used because of its good dispersibility in the resin composition and good mechanical properties of the resin composition.

  However, in order to exhibit the desired conductivity, a molded product is produced by using a conductive resin composition containing a large amount of carbon black, particularly by processing under severe conditions such as fine molding, high-speed molding, and long-time molding. When performing molding or the like, decomposition or deterioration of the conductive resin composition is promoted by the carbon black contained, and as a result, volatile components are generated during molding, and the volatile components adhere to the mold and mold contamination. There is a problem that molding defects occur.

In order to solve these problems, it is proposed to reduce the amount of volatile components generated by increasing the drying temperature of the polycarbonate resin before melt-kneading the polycarbonate resin composition containing the polycarbonate resin and the conductive material. (See Patent Document 1). In addition, a resin composition containing a polyester resin and carbon black having an ash content of 30 ppm or less and suppressing the promotion of hydrolysis and deterioration by carbon black during kneading has been proposed (see Patent Document 2).
However, even in these cases, there is still a problem that it is difficult to sufficiently suppress volatile components generated during molding of the molded product.

JP 2002-53747 A JP 2002-220518 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide a conductive resin composition with a small amount of volatile components generated during molding without impairing mechanical properties and high dispersibility of carbon black.

  As a result of intensive studies by the present inventors to solve the above problems, the present invention contains a polyalkylene phthalate resin, carbon black, a hindered phenolic antioxidant, and a metal deactivator. The conductive resin composition can reduce the amount of volatile components generated during molding of a molded product using the conductive resin composition without impairing mechanical properties and high dispersibility of carbon black. I found out.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> A conductive resin composition comprising a polyalkylene phthalate resin, carbon black, a hindered phenol antioxidant, and a metal deactivator.
<2> The conductive resin composition according to <1>, wherein the metal deactivator is a hydrazide derivative.
<3> The conductive resin composition according to any one of <1> to <2>, further including at least one selected from a polycarbonate resin and a polyarylate resin.

  According to the present invention, it is possible to provide a conductive resin composition that can solve various problems in the prior art and has a small amount of volatile components generated during molding without impairing mechanical properties and high dispersibility of carbon black. .

(Conductive resin composition)
The conductive resin composition of the present invention comprises a polyalkylene phthalate resin, carbon black, a hindered phenol antioxidant, and a metal deactivator, and further appropriately selected as necessary. It contains other thermoplastic resin and other components.

-Polyalkylene phthalate resin-
The polyalkylene phthalate resin is not particularly limited and may be appropriately selected depending on the intended purpose. The polyalkylene phthalate resin is produced by polycondensation of various phthalic acids or ester derivatives thereof and alkylene glycol as main components. In addition, the main structure may be a resin made of polyalkylene phthalate and a copolymer containing other components. The molecular structure of the polyalkylene phthalate resin is not particularly limited, and in the case of a copolymer, any molecular structure such as a random body, a block body, and a linear, branched, or crosslinked molecule may be used. In addition, the degree of polymerization of the polyalkylene phthalate resin is not particularly limited as long as it has molding processability, and can be appropriately selected according to the purpose. For example, measurement of ο-chlorophenol solution at 25 ° C. Those having an intrinsic viscosity of 0.5 to 1.5 (100 ml / g) are desirable.

  Examples of the polyalkylene phthalate resin include polybutylene terephthalate, polybutylene terephthalate isophthalate copolymer, polyethylene terephthalate, polyethylene terephthalate isophthalate copolymer, and the like. The polyalkylene phthalate resin can be used alone or mixed with one or more other thermoplastic resins at an arbitrary ratio.

  There is no restriction | limiting in particular as said other thermoplastic resin, Although it can select suitably according to the objective, From a compatible viewpoint with polyalkylene phthalate resin, especially polycarbonate resin and polyarylate resin are preferable. The amount of the other thermoplastic resin added is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 to 2,300 parts by mass with respect to 100 parts by mass of the polyalkylene phthalate resin.

-Polycarbonate resin-
There is no restriction | limiting in particular as said polycarbonate resin, Although it can select suitably according to the objective, For example, what is manufactured with the solution method or melting method of bihydric phenol and a carbonate precursor is mentioned. Examples of the divalent phenol include bis (4-hydroxyphenyl) alkane compounds and bisphenol A, and bisphenol A is more preferable.
The dihydric phenol can be used alone or in combination of two or more. For example, bisphenol A [2,2-bis (4-hydroxyphenyl) propane], bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, and the like. Examples of the carbonate precursor include carbonyl halides, carbonates, dihaloformates of dihydric phenols, and mixtures thereof. Furthermore, in the production of the aromatic polycarbonate, an appropriate molecular weight regulator, branching agent, catalyst, etc. can be used.

-Polyarylate resin-
The polyarylate resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is produced by a melt polymerization method, a solution polymerization method, an interfacial polymerization method, or the like using a dihydric phenol and an aromatic dicarboxylic acid. Can be mentioned.
As the divalent phenol, a bis (4-hydroxyphenyl) alkane compound is preferable, and bisphenol A is more preferable. The dihydric phenols can be used alone or in admixture of two or more. For example, bisphenol A [2,2-bis (4-hydroxyphenyl) propane], bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy) -3-methylphenyl) propane, and the like. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like.

-Carbon black-
The carbon black is not particularly limited and may be appropriately selected depending on the intended purpose. From the viewpoint of conductivity, carbon dispersibility, and the like, n-dibutyl phthalate (DBP) oil supply amount is 100 to 400 ml / 100 g. Is preferred. When the DBP oil supply amount exceeds 400 ml / 100 g, the carbon dispersion state may deteriorate, and when the DBP oil supply amount is less than 100 ml / 100 g, the conductivity imparting effect may be inferior.

  Commercially available products may be used as the carbon black, and examples thereof include Ketjen Black EC (manufactured by Lion), Vulcan XC-72 (manufactured by Cabot), Denka Black (manufactured by Denki Kagaku Kogyo), and the like. . In addition, naphtha and other hydrocarbons are partially oxidized in the presence of hydrogen and oxygen, and carbon black having the above characteristics that is replicated when producing synthesis gas containing hydrogen and carbon monoxide, or this is oxidized or reduced. Examples thereof include carbon black having the above characteristics in which the amount of n-dibutyl phthalate (DBP) is 100 to 400 ml / 100 g.

There is no restriction | limiting in particular as content of the said carbon black, Although it can select suitably according to the objective, 5 mass parts-20 mass parts are preferable with respect to a total of 100 mass parts of the said conductive resin composition, 6-15 mass parts is more preferable.
When the content is less than 5 parts by mass, the effect of imparting conductivity to the molded product may be reduced. When the content exceeds 20 parts by mass, the amount of aggregates increases and carbon black is uniformly contained in the resin. It may be difficult to disperse the resin in the water.

-Hindered phenolic antioxidants-
The hindered phenol antioxidant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, pentaerythritol tetrakis [3- (3,5-di-t-butyl-hydroxyphenyl) Propionate], thiodiethylene [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N , N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide], benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) ) -4-hydroxy, C7-C9 side chain alkyl ester, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] me L] phosphonate, 3,3 ′, 3 ″, 5,5 ′, 5 ″,-hexa-t-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol , Ethylenebis (oxyethylene) bis [3- (5-t-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate], and the like.

There is no restriction | limiting in particular as content of the said hindered phenol antioxidant, Although it can select suitably according to the objective, 0.05-2 mass with respect to a total of 100 mass parts of the said conductive resin composition. Part is preferable, and 0.1 to 1 part by mass is more preferable.
When the content is less than 0.05 parts by mass, the effect may be small. When the content exceeds 2 parts by mass, bleeding may occur during molding and cause mold contamination.

-Metal deactivator-
There is no restriction | limiting in particular as said metal deactivator, Although it can select suitably according to the objective, For example, a salicylic acid derivative, a hydrazide derivative, an oxalic acid amide derivative, a sulfur containing phosphite, etc. are mentioned. Among these, hydrazide derivatives are preferable because they have a high effect of suppressing volatile components.
Specific examples of the metal deactivator include 2 ′, 3-bis [[3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionyl] propionohydrazide, 3-N ′. -Salicyloylamino-1,2,4-triazole, salicylhydrazine, salicylaldehyde, oxalyl-bis [benzylidenehydrazide], tris [2-tert-butyl-4'-thio (2'-methyl-4'-hydroxy) -5-t-butyl) phenyl-5-methyl] phenyl phosphite, and the like.

There is no restriction | limiting in particular as content of the said metal deactivator, Although it can select suitably according to the objective, 0.05-2 mass parts with respect to a total of 100 mass parts of the said conductive resin composition. Is preferable, and 0.1-1 mass part is more preferable.
When the content is less than 0.05 parts by mass, the effect of suppressing the generation of volatile components may be small. When the content exceeds 2 parts by mass, bleeding out during molding may cause mold contamination. There is.

-Other ingredients-
Examples of the other components include lubricants, lubricants, nucleating agents, dyes / pigments, mold release agents, various stabilizers, other thermoplastic resins, reinforcing agents, fillers, and the like.

(Method for producing conductive resin composition)
In the conductive resin composition, the polyalkylene phthalate resin, the carbon black, the hindered phenol antioxidant, and the metal deactivator are mixed and kneaded by appropriately selected known methods. For example, it can be melt-kneaded to form a pellet compound.
There is no restriction | limiting in particular as the method of setting it as the said pellet-form compound, It can manufacture easily using the apparatus and equipment used for mixing and kneading | mixing of a normal resin composition. For example, the thermoplastic resin containing the polyalkylene phthalate resin, the carbon black, the hindered phenolic antioxidant, and the metal deactivator all coexist, and the heat containing the polyalkylene phthalate resin. The plastic resin, the hindered phenol-based antioxidant, and the metal deactivator can be kneaded for 30 seconds or longer in a state where the resin is heated and melted.
At this time, the blending order of the respective components is not particularly limited, but it is preferable to blend the hindered phenol antioxidant, the metal deactivator, and the polyalkylene phthalate resin simultaneously. Specifically, the thermoplastic resin containing the polyalkylene phthalate resin, the carbon black, the hindered phenol-based antioxidant, and the metal deactivator are previously mixed in a mixer such as a tumbler or a Henschel mixer. After uniformly mixing, the mixture is supplied to a single or twin screw extruder and melt kneaded, or the thermoplastic resin containing the polyalkylene phthalate resin, and the hindered phenol antioxidant A method of supplying the carbon black from a side feeder after premixing the metal deactivator, supplying the mixture to a single-screw or twin-screw extruder and melt-kneading the mixture (for example, JP-A-7-53767). Etc.), etc., and may be subjected to molding or may be directly molded.

  The processing temperature at the time of the melt kneading is preferably 5 to 50 ° C. higher than the temperature at which the thermoplastic resin component melts, and preferably 10 to 30 ° C. higher than the melting point of the thermoplastic resin. If the treatment temperature is too high, resin decomposition and abnormal reactions may be induced. The treatment time for the melt kneading is preferably 30 seconds to 10 minutes, more preferably 1 to 5 minutes.

  The conductive resin composition can be easily obtained by the adjustment method described above. The obtained conductive resin composition can be obtained by a known molding method such as injection molding, extrusion molding, transfer molding, inflation molding, directly or via pellets, etc. Various conductors can be manufactured. In addition, secondary molded bodies such as carrier tapes, soft trays, and other members for electric and electronic parts can be produced from these primary molded bodies by known molding methods such as vacuum molding, pressure molding, and press molding. .

  Hereinafter, although the Example of this invention is described, this invention is not limited to this Example at all.

(Examples 1-4 and Comparative Examples 1-4)
The conductive resin compositions of Examples 1 to 4 and Comparative Examples 1 to 4 having the compositions shown in Table 1 below were prepared according to a conventional method. In addition, the numerical value in Table 1 represents the mass part with respect to 100 mass parts of said conductive resin compositions.

  Specifically, each compounding component was pre-blended with a polyalkylene phthalate resin and oxidized using a twin screw extruder NR-II (manufactured by Nakatani Machinery Co., Ltd., screw diameter = 57 mm) from the original hopper of the extruder. A mixture of a thermoplastic resin containing an inhibitor and a metal deactivator is supplied by a quantitative feeder, and when the thermoplastic resin is completely melted, carbon black is forced through the side feeder by the quantitative feeder and the extruder. And the conductive resin composition was kneaded to obtain a compound. Subsequently, after cooling this, it was set as the cylindrical pellet (diameter 2mm, length 2-4mm) using the pelletizer.

  Using the obtained pelletized conductive resin composition, volatile components were evaluated by the following method. The results are shown in Table 1.

-Measurement method of volatile components-
70 g of the obtained conductive resin composition pelletized was put into a lab plast mill (manufactured by Toyo Seiki Co., Ltd.) and completely covered with 10.0 cm × 10.0 cm hard glass. In this state, the volatile matter generated when kneaded at 300 ° C. for 5 minutes was adhered to the glass plate, the haze value was measured with a digital goniophotometer (manufactured by Suga Test Instruments), and evaluated according to the following evaluation criteria. In addition, it shows that the haze value is smaller, the haze of the glass plate is smaller and the amount of volatile components generated is smaller.
〔Evaluation criteria〕
◎ ・ ・ ・ Haze value less than 2 ○ ・ ・ ・ Haze value 2 or more and less than 6 △ ・ ・ ・ Haze value 6 or more and less than 10 × ・ ・ ・ Haze value 10 or more

The abbreviations in Table 1 are as follows.
PBT (polybutylene terephthalate resin): “700FP” made by polyplastics [Intrinsic viscosity 0.97 (100 ml / g)]
PET (polyethylene terephthalate resin): “MA521H” manufactured by Mitsubishi Rayon Co., Ltd. [intrinsic viscosity 0.78 (100 ml / g)]
PC (polycarbonate resin): A mixture of 73% by mass “A2700” (MFR: 5 g / 10 min) manufactured by Idemitsu Petrochemical Co., Ltd. and 27% by mass of “IR1700H” manufactured by Idemitsu Petrochemical Co., Ltd. PAR (polyarylate resin) ): “U100” manufactured by Unitika Ltd.
CB (carbon black): Lion Corporation Ketjen Black EC (DBP oil absorption: 360 ml / 100 g)
Acid (i) (hindered phenol antioxidant): “Irganox 1010” manufactured by Ciba Specialty Chemicals Co., Ltd.
Acid-proof (ii) (hindered phenol antioxidant): “Adeka Stub AO-330” manufactured by Asahi Denka Kogyo Co., Ltd.
-Acid protection (iii) (phosphite antioxidant): "Adeka Stub PEP-36" manufactured by Asahi Denka Kogyo Co., Ltd.
-Acid protection (iv) (sulfur-based antioxidant): "Irganox PS800FL" manufactured by Ciba Specialty Chemicals Co., Ltd.
Inactive (i) (hydrazide metal deactivator): “Irganox MD1024” manufactured by Ciba Specialty Chemicals Co., Ltd.
Inactivation (ii) (salicylic acid-based metal deactivator): “Adeka Stub CDA-1” manufactured by Asahi Denka Kogyo Co., Ltd.

  From the results in Table 1, it was found that all of the conductive resin compositions of Examples 1 to 4 have a small amount of volatile components generated during molding and can prevent mold contamination and molding defects. In particular, the conductive resin compositions of Examples 1, 2 and 4 using a hydrazide metal deactivator as the metal deactivator can further reduce the amount of volatile components generated during molding. I understood. On the other hand, it turned out that the conductive resin composition of Comparative Examples 1-4 cannot be suppressed to the level which satisfies the quantity of the volatile component which generate | occur | produces at the time of shaping | molding of a molded article.

The conductive resin composition of the present invention can be suitably used for molded articles such as carrier tapes, magazines, trays, bags and the like as packaging for members for electric and electronic parts such as ICs and LEDs. Although it is particularly suitable for a carrier tape, both strength and conductivity are sufficient for use as a carrier tape.

Claims (3)

  A conductive resin composition comprising a polyalkylene phthalate resin, carbon black, a hindered phenol-based antioxidant, and a metal deactivator.   The conductive resin composition according to claim 1, wherein the metal deactivator is a hydrazide derivative. The conductive resin composition according to claim 1, further comprising at least one selected from a polycarbonate resin and a polyarylate resin.