JPS6143659A - Conductive polycarbonate resin composition - Google Patents

Abstract

PURPOSE:The titled composition having improved electrical conductivity, processing properties and mechanical properties, high industrial value, obtained by blending an aromatic polycarbonate resin with carbon black having length of crystal >=a specific value and an alicyclic epoxy compound. CONSTITUTION:(A) An aromatic polycarbonate resin is blended with (B) 5- 30wt%, preferably 7-20wt% carbon black having >=35Angstrom , preferably >=40Angstrom length of crystal, <=100m<2>/g, preferably 15-80m<2>/g specific surface area, and <=0.3%, preferably <=0.2% volatile content, obtained by heating carbon black in N2 flow at >=2,500 deg.C, and (C) 0.01-3wt%, preferably 0.05-2wt% alicyclic epoxy compound, preferably a compound containing 1-2 epoxycyclohexyl groups, kneaded in a molten state by an extruder, and pelletized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a conductive polycarbonate resin composition. Specifically, the present invention relates to a conductive polycarbonate resin composition having excellent moldability and mechanical properties.

Conductive plastics are useful as parts of electrical and electronic devices such as computers and i-photographers, and polycarbonate resins have high expectations in particular because of their high heat resistance.

In particular, damage to electronic components caused by static electricity is a major problem in electrical and electronic equipment such as computers and copying machines.

In response to the demand for antistatic properties to prevent damage caused by static electricity, the industrial use of polycarbonate resins having a volume resistivity/(770·G or less or less) is being greatly expanded.

〔Jubei Keijutsu〕

It is known to add carbon black to a polycarbonate resin in order to make it conductive. (For example, JP-A-Sho, tj-/, 3, 5) However, the volume resistivity 1 required for industrial use
If the content of carbon black is increased in order to have conductivity of 0 rΩ or less, the composition becomes difficult to mold by melt mixing, extrusion, or injection molding, and even if it can be molded, the tensile strength and impact resistance will deteriorate. Only molded products with significantly inferior mechanical properties can be obtained.

[Purpose of the invention]

The present inventors have conducted intensive research to obtain a conductive polycarbonate resin composition with excellent moldability and mechanical properties, and have found that when polycarbonate contains a specific carbon black and a specific epoxy compound, The present invention was completed by discovering that molding processability can be improved and molded products with extremely excellent mechanical properties and electrical conductivity can be obtained.

That is, the present invention aims to provide a conductive polycarbonate resin composition of great industrial value, and its gist is to provide an aromatic polycarbonate resin with a crystallite length (LOJ of ? This is a conductive polycarbonate resin composition containing the above carbon black and alicyclic epoxy compound.

[Structure of the invention]

The present invention will be explained in detail below.

The aromatic polycarbonate resin used in the present invention is a polymer or copolymer obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate. Typical examples include yu, corbis (cyphenylfufuropane (bisphenol A) in derhydro).
Examples include polycarbonate resins manufactured from

Examples of the dihydroxydiaryl compounds include bispheno-/l/A, bis(4t-hydroxyphenyltumethane, i,i-bis[derhydroxyphenyl]ethane, co-bis(terhydroxyphenylbutane),
Tips - Bis(derhydroxyphene A/)octane,
゛Bis(Hiro-Hydrodiphenyl)phenylmethane, Co, Nibis(Dahido axy J-Methylphenyl)propane, i, i-Bis(Tei-HydoadPcyJ-J-th Butylphenyl)propane, Di, λ- Bis(l-hydroxy-, 7-7” romophenylnopropane.

Co, Corbis(Hiro-Hydroxy-3,!Dizolomofenyl)propane,Yu,-bis(Terhydroxy-J
, J-dichloropheni/L/) bis(
Hydroxyarylene alkanes 13 L/l/-His(cyphenylnocyclopentane in derhydro, ], bis[hydroxyarylcocycloalkanes such as l-bis-hydroxyphenylcocyclohexane, 41.styl-dihydroxydiphenyl ether , dihydroxydiarylethers such as Shimada'-dihydroxy-3゜3'-dimethyldiphenyl ether, +4'-dihydroxydiphenyl sulfide, +, +'-dihydroxy-3.3'-dimethyldiphenyl sulfide, etc. dihydroxydiaryl sulfides, Hiroshi, 3'-dihyde cI+?cidiphenyl sulfonate.

dihydroxydiaryl sulfoxides such as da, 3'-dihydroxy-J, 3'-dimethyldiphenyl sulfoxide, da, da'-dihydroxydiphenyl sulfone, p, a'-dihydroxy-17,17'-dimethylsiphenylsulfone, etc. Examples include dihydroxydiarylsulfones.

These can be used alone or in a mixture of two or more, but
In addition to these, a mixture of terephthalic acid chloride, isophthalic acid chloride, piperazine, piperidyl, hyde chloride, resorcinol, dihydroxydiphenyl, etc. may be used.

The carbon black of the present invention has a crystallite length (LcJ of 3!
Among carbon blacks having a carbon black of rX or higher, particularly preferred are carbon blacks with a carbon black of rX or higher.

Among them, the specific surface a (low-temperature nitrogen adsorption method using the BJ”T formula) is / 0
0 rrVI or less, preferably lj to l0rrl/1
The thing is (.

In addition, the volatile content (ASTM D/4 0-10) is 0.
．． 3% or less, preferably o, flathead or less is suitable.

If Lc is too small, a composition with excellent single-function properties and a low volume resistivity cannot be obtained.

On the other hand, a large Lc is not particularly disadvantageous, but JooX is the upper limit from the viewpoint of the carbon black manufacturing method.

As such carbon black, Mitsubishi Chemical Industries ■
split, trademark, Mitsubishi Carbon Black Nahiro 010B, same a
Examples include Oda OB.

As a method for obtaining carbon black having La of sk'jj- or higher, it is usually carried out in an oxygen-free atmosphere, for example, in a gas stream, in a vacuum, or in carbon powder (-named snail powder and 1 usually coke powder). ) is used in which carbon black is heated to a temperature above 100°C.

In this case, the presence of oxygen in the atmosphere reduces the yield of carbon black, so it is preferable that the oxygen concentration in the atmosphere be 1 volume H2 or less. Also other oxidizing properties? It goes without saying that it is preferable to reduce the amount of gas contained as much as possible.

When carrying out the above heat treatment on a large scale, it is advantageous to use the Acheson type electric furnace 7. When carrying out the heat treatment on a small scale, a prescribed amount of carbon black is filled into a graphite pipe and this is buried in carbon powder. After that, you can pass an alternating current to both ends of the pipe.

In this way, when carbon black is heat-treated, the crystallites inside the carbon black are rearranged and the shape changes.
Although the particle size is slightly smaller.

The crystallite grows and becomes longer.

The alicyclic epoxy compound used in the present invention is preferably a compound having an alicyclic ring having an oxygen bridge bonded to an adjacent carbon atom.

Containing two epoxycyclohexyl groups
□It is a compound that

For such compounds.

, 7,4C-epoxycyclohexylmethyl-3,4
! -Epoxycyclohexanecarboxylate, J, 4
I-epoxy-6-methylcyclohexyl-J, #-epoxy-6-methylcyclohexanecarboxylate, co, J-epoxy-6-methylcyclohexyl-3, dicyclohexanecarboxylate in terepoxy.

$-(J, Hiro-Evokai!-Methylcyclohexyl 2
-Butyl-3, Hiro-epoxycyclohexanecarboxylate.

3.Hori-epoxycyclohexylethylene oxide, bis(J, l-epoxy-6-methylcyclohexylmethyl λ adipate.

Cyclohexylmethyl-,7,II-epoxycyclohexanecarboxylate.

J, terepoxy-6-methylcyclohegycylmethyl-6-methylcyclohexylcarboxylate.

Vinyl cyclohexene oxide.

Examples include bis(J, lI-epoxycyclohexylmethyl) adipate, 4-(J, epoxycyclohexyl-!, !-xhyo-, 7.4A-epoxycyclohexane-metadioxane), and the like.

The composition of the present invention may contain other resins, such as impact modifiers such as polyolefin, ABC, polyester, polystyrene, or modified ethylene copolymers, and glass fibers, to the extent that their physical properties are not impaired. Reinforcing agents such as glass peas, glass flakes, metal flakes, metal fibers, carbon fibers or other additives such as silica, alumina, magnesia, kaolin, silica-alumina-merck, silica-magnesia,
Fillers such as bentonite, calcium silicate, and surface treatments such as silanizing agents.

Flame retardants such as decabromodiphenyl ether, tri-R-7-thimones, paraffins, and lubricants such as fatty acid esters.

In addition, one foaming agent, one stabilizer, one coloring agent, etc. may be included.

The polycarbonate resin composition of the present invention can be prepared at any stage up to the production of the final molded article.

This can be done by incorporating the above-mentioned components by various means. For example, there is a method in which the above-mentioned components are mixed, melt-kneaded using an extruder, extruded, and pelletized, and a method in which components other than carbon black are melt-kneaded, extruded, and pelletized to produce an Et final molded product. Examples include a method of blending carbon black, a method of melt-kneading components other than polycarbonate resin and carbon black, and then blending polycarbonate resin.

The conductive polycarbonate resin composition of the present invention contains the carbon brane in an amount of 5 to 30% by weight, preferably 7 to -0 i% by weight.

and the alicyclic epoxy compound yo, oi-J, o weight%
, preferably from 0.05 to 0 to 0.

If the amount of carbon black is too large, the melt fluidity will decrease and it will be impossible to obtain molded articles with excellent mechanical properties.

On the other hand, if it is too small, a product with sufficient conductivity cannot be obtained.

If the amount of the alicyclic epoxy compound is too large, it will not be possible to obtain a molded article with excellent mechanical properties, and problems will also arise in fluidity and heat resistance.

On the other hand, if the amount is too small, a product with sufficient conductivity cannot be obtained. In the present invention, the alicyclic epoxy compound is Xra
When the carbon black is Js'A or higher, it acts with a specific carbon black and exhibits the effect of imparting electrical conductivity. It is an important recognition of the present inventors that they have discovered a synergistic effect produced by both.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

In the examples, "part" indicates the part where X is placed. The tensile strength is ABTM D 1.3g, and the Izod impact value is A137M Da36. The volume resistivity is a value measured according to ABTM D 444-j'4cT.

Example 1-g and Comparative Examples 7-9 Molecular weight λ3. ! θθ polycarbonate [manufactured by Mitsubishi Chemical Corporation, Tubarex 70 pieces! to rAJ.

Carbon black and epoxy compounds were blended at the compounding ratio shown in the table below.
The mixture was melt-kneaded and extruded into pellets using a MAEi type 30xx vent type) at <RTIgt;

The crystallite length in the 0-axis direction of the carbon used here, black; the measurement results of LC are shown in Table 1.

The measurement was carried out using an automatic recording type X-ray diffractometer (Rigaku wo Kiki), with tube: Ou, filter: N1 voltage, 7J-KV,
'! i flow; 301r LA divergence slit; /6# light receiving slit; I did some measurements.

Crystallite length in the C-axis direction; for Lc, September 1, 1919
It was calculated using the following formula according to the method described in Kuchimaruzen ■ Publication 1 Handbook Carbon Black, page 210.

LO=0. t9λ/BCOaθ where λ is the wavelength of the X-ray (], yoah) B is the width expressed in angle of interference at half the maximum intensity (phantom θ is the Bragg' reflection angle (degrees).

The pellets were molded using a 3.6 oz injection molding machine (Toshiba Machine Model S-7 to 8) and a metal test piece specified by ABTM at a resin temperature of 190°C and a mold temperature of to°C. .

The tensile strength, notched Izot impact value, and volume resistivity of the obtained molded article were as shown in Table 7 below.

Table - Examples! And Comparative Example 1 O~L Using the same polycarbonate as used in Example 1, carbon black, epoxy compound and glass fiber (Asahi Fiberglass Chopped Strand QfF303MAIIO90) were added at the compounding ratio shown in Table 3 below. 'h nib V7) 'L,! The mixture was melt mixed at soo°C using a 411 machine and extruded into pellets.

The pellets were injection molded as in Example 1. The tensile strength, impact value, and volume resistivity of the obtained molded product were as shown in Table 3 below.

〔Effect of the invention〕

The composition of the present invention has excellent conductivity, processability, and mechanical properties, so it can be used in electrical and electronic devices by various molding methods such as extrusion, injection, and compression.

It is possible to obtain molded products of moderate shapes that are useful as industrial materials for automobiles, aircraft, and others.

Questioner: Mitsubishi Chemical Industries, Ltd.

Claims (3)

[Claims] (1) Crystallite length (Lc
) A conductive polycarbonate resin composition containing carbon black having a thickness of 35 Å or more and an alicyclic epoxy compound. (2) The conductive polycarbonate resin composition according to claim 1, wherein the content of carbon black is 5 to 30% by weight based on the total amount of the composition. (3) The conductive polycarbonate resin composition according to claim 1 or 2, wherein the content of the alicyclic epoxy compound is 0.01 to 3 parts by weight based on the total amount of the composition.