A destaticizing thermoplastic resin composition compristing PA1 (A) a thermoplastic resin; PA1 (B) a polymer having a surface resistivity measured at 500 V of 10.sup.8 to 10.sup.11 .OMEGA., a melting point of 100.degree. C. or higher, an apparent malt viscosity at an apparent shear rate at 260.degree. C. of 1,000 sec.sup.-1 of 10 to 1,000 Pa.multidot.s, and a ratio of the above apparent melt viscosity to the apparent melt viscosity of the thermoplastic resin at an apparent shear rate at 260.degree. C. of 1,000 sec.sup.-1 of 0.01 to 1.3; or a carbon fiber having a diameter of 1 nm to 1 .mu.m, a length of 1 .mu.m to 10 mm and a volume resistivity of less than 1 .OMEGA.cm; or a combination of the polymer and the carbon fiber; and PA1 (C) a fibrous conductive filler having a volume resistivity of 100 .OMEGA..multidot.cm or less. The destaticizing composition is useful for preparation of a carrier jig for use in an electronic field.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to a destaticizing thermoplastic resin 
composition and to a carrier jig made therefrom for use in an electronic 
field. More specifically, it relates to a thermoplastic resin composition 
which is readily electrified and has excellent destaticizing properties 
that voltage attenuates swiftly even when it is electrified and to a 
carrier jig made therefrom for use in the electronic field. 
A thermoplastic resin is readily electrified by friction or peeling and 
causes various problems in its molded products, such as impact and 
adhesion of dust caused by discharging at the time of use. 
As means of providing antistatic properties to a thermoplastic resin, there 
have been known a method in which a low-molecular antistatic agent such as 
a phosphonium salt of alkyl sulfonic acid is used (JP-A 62-230835) (the 
term "JP-A" as used herein means an "unexamined published Japanese patent 
application") and a method in which a high-molecular antistatic agent such 
as a polyether ester amide is used. The low-molecular antistatic agent has 
a large initial effect but loses its antistatic properties when it is used 
to wipe something or washed. Thus, its performance changes according to 
environmental changes. The high-molecular antistatic agent has a problem 
with heat resistance or melt stability in many cases when it is used in 
engineering plastics, and it is difficult to reduce saturation voltage to 
1 kV or less and voltage half-attenuation time to 10 sec or less 
(application voltage of 10 kV) simply by increasing the content of the 
high-molecular antistatic agent. Even if the high-molecular antistatic 
agent can exhibit this performance, deterioration in physical properties 
and a problem with productivity will occur. 
As means of providing antistatic properties and rigidity to a thermoplastic 
resin, there is known a method in which a carbon fiber is added (JP-A 
8-88266). In the case of a carbon fiber alone, it is possible to reduce 
resistivity and saturation voltage by increasing its content but it is 
difficult to reduce voltage half-attenuation time to 10 sec or less 
(application voltage of 10 kV). Further, a method in which a conductive 
filler or powder having a small aspect ratio is combined with a carbon 
fiber or stainless fiber satisfies the above requirements but is not 
preferred as a carrier jig for use in the electronic field because waste 
conductive powders are produced at the time of molding. 
JP-A 7-173325 discloses an antistatic resin composition which comprises an 
organic macromolecular material, a carbon-based conductive filler and a 
non-carbon-based conductive filler having a volume resistivity of 0.5 to 
10.sup.8 .OMEGA.cm. This composition has such an advantage that the amount 
of an expensive non-carbon-based conductive filler used can be reduced. 
Further, JP-A 4-8769 discloses an antistatic and ionic conductive resin 
composition which comprises 100 parts by weight of a resin, 0.1 to 70 
parts by weight of a high-molecular weight compound having an average 
molecular weight of 10,000 or more and obtained by reacting 
polyoxyalkylene glycol and a polyvalent carboxylic acid or an organic 
polyisocyanate, and 0.1 to 30 parts by weight of a conductive filler. This 
publication names powder and granular materials as illustrative examples 
of the above conductive filler. The powder or granular material is not 
preferred as a carrier jig for use in the electronic field because it 
often falls off at the time of molding or use. 
A water carrier jig preferably has a diameter of 12 inches or more to 
improve the productivity of silicon wafers. A thermoplastic resin 
composition prepared simply by adding an high-molecular antistatic agent 
to a thermoplastic resin is preferred because it rarely suffers from 
differences in antistatic properties by a washing step and such a problem 
as the contamination of silicon wafers by a dissolution metal. However, it 
is unsatisfactory in terms of rigidity and abrasion resistance as a 
carrier jig having a diameter of 12 inches or more and cannot be 
incorporated into automation. Along with an increase in the integration of 
integrated circuits, the size of particles causing electrostatic 
interferences is becoming very small, and current antistatic properties 
are insufficient. 
Meanwhile, when a low-molecular antistatic agent is used as a carrier jig 
for use in the electronic field, the amount of a dissolution metal in the 
washing step is large, thereby causing the lack of crystals for devices 
and reductions in electric properties. 
When a carbon fiber is added to a thermoplastic resin, it is difficult to 
obtain stable conductive properties according to the shape of a carrier 
jig for use in the electronic field even by adding a large amount of the 
carbon fiber (may be abbreviated as CF hereinafter). This is probably 
because of poor dispersibility of CF. On the other hand, when a small 
amount, namely 8 wt %, of CF is added, the voltage half-attenuation time 
is 600 sec or more (when the application voltage is 10 kV) on the surface 
of a carrier jig, and only a carrier jig from which a charge is hardly 
leaked and which has unsatisfactory antistatic properties can be obtained. 
It is an object of the present invention to provide a thermoplastic resin 
composition having high and permanent antistatic properties, excellent 
destaticizing properties and small differences in antistatic properties 
(saturation voltage and voltage half-attenuation time) on the surface of a 
molded product. 
It is another object of the present invention to provide a carrier jig for 
use in the electronic field which is made from a resin composition having 
excellent destaticizing properties, and has high rigidity required for a 
large-sized carrier jig and uniform and excellent antistatic properties on 
the surface. 
It is still another object of the present invention to provide a carrier 
jig for use in the electronic field which has high rigidity required for a 
large-sized silicon wafer carrier jig such as a 12-inch or more silicon 
wafer carrier jig, uniform and excellent antistatic properties on the 
surface, excellent destaticizing properties and extremely small 
differences in antistatic properties (saturation voltage and voltage 
half-attenuation time) on the surface of a molded product. 
Other objects and advantages of the present invention will be apparent from 
the following description. 
According to the present invention, firstly, the above objects and 
advantages of the present invention can be attained by a destaticizing 
thermoplastic resin composition (may be referred to as "first composition 
of the present invention" hereinafter) which is a compound comprising: 
(A) 100 parts by weight of a thermoplastic resin; 
(B) 10 to 200 pats by weight of a polymer having a surface resistivity 
measured at 500 V of 10.sup.8 to 10.sup.11 .OMEGA., a melting point of 
100.degree. C. or higher, an apparent melt viscosity at an apparent shear 
rate at 260.degree. C. of 1,000 sec.sup.-1 of 10 to 1,000 Pa.multidot.s, 
and a ratio of the above apparent melt viscosity to the apparent melt 
viscosity of the above thermoplastic resin at an apparent shear rate at 
260.degree. C. of 1,000 sec.sup.-1 of 0.01 to 1.3; and 
(C) 1 to 100 parts by weight of a fibrous conductive filler having a volume 
resistivity of 100 .OMEGA.cm or less.

The first composition of the present invention will be described 
hereinunder. 
Thermoplastic Resin (A) 
The thermoplastic resin used in the present invention is a polymer 
comprising a structural units derived from at least one monomer selected 
from the group consisting of styrenes, (meth)acrylate esters, 
(meth)acrylonitrile and butadiene, polyolefin, polyester, polycarbonate, 
acryl resin, thermoplastic polyurethane, polyvinyl chloride, fluororesin, 
polyamide, polyacetal, polysulfone or polyphenylene sulfide. They may be 
used alone or in combination of two or more. 
The styrenes include styrene and substituted styrenes such as 
methylstyrene. 
Resins composed of a polymer and/or a copolymer having at least one 
structural unit selected from the group consisting of styrenes, 
(meth)acrylates, (meth)acrylonitrile and butadiene include polystyrene, 
styrene/acrylonitrile copolymer, acrylonitrile/butadiene/styrene 
copolymer, methyl methacrylate/butadiene/styrene copolymer, methyl 
methacrylate/ethyl methacrylate/butadiene/styrene copolymer and 
styrene/methyl methacrylate/acrylonitrile copolymer. 
The polyolefin is, for example, polyethylene or polypropylene. 
The polyester is preferably an aromatic polyester comprising terephthalic 
acid or 2,6-naphthalenedicarboxylic acid as a main acid component and an 
aliphatic diol such as ethylene glycol, trimethylene glycol, 
tetramethylene glycol, hexamethylene glycol or neopentyl glycol as a main 
diol component. 
The "main acid component" means an acid component which is contained in an 
amount of 70 mol % or more, preferably 80 mol % or more, more preferably 
90 mol % or more based on the total of all acid components and the "main 
diol component" means a diol component which is contained in an amount of 
70 mol % or more, preferably 80 mol % or more, more preferably 90 mol % or 
more based on the total of all diol components. 
Out of the aromatic polyesters, polybutylene terephthalate, polypropylene 
terephthalate, polyethylene terephthalate and polybutylene-2,6-naphthalate 
having high crystallization speed are preferred, and polybutylene 
terephthalate is particularly preferred. 
The polyester may be a substituted polyester part of which is substituted 
by a copolymerizable component. Illustrative examples of the 
copolymerizable component include isophthalic acid, phthalic acid; alkyl 
substituted phthalic acids such as methyl terephthalic acid and methyl 
isophthalic acid; naphthalenedicarboxylic acids such as 
2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid and 
1,5-naphthalenedicarboxylic acid; aromatic dicarboxylic acids such as 
diphenyldicarboxylic acids exemplified by 4,4-diphenyldicarboxylic acid 
and 3,4-diphenyldicarboxylic acid and diphenoxyethanedicarboxylic acids 
exemplified by 4,4-diphenoxyethanedicarboxylic acid; aliphatic and 
alicyclic dicarboxylic acids such as succinic acid, adipic acid, sebacic 
acid, azelaic acid, decanedicarboxylic acid and cyclohexanedicarboxylic 
acid; alicyclic diols such as 1,4-cyclohexanedimethanol; dihydroxybenzenes 
such as hydroquinone and resorcin; aromatic diols such as ether diols 
obtained from bisphenols such as 2,2-bis(hydroxyphenyl)-propane and 
bis(4-hydroxyphenyl)sulfone and glycols such as ethylene glycol; 
oxycarboxylic acids such as .epsilon.-oxycaproic acid, hydroxybenzoic acid 
and hydroxyethoxybenzoic acid; and the like. The above aromatic polyesters 
may contain a polyfunctional ester forming acid such as trimesic acid or 
trimellitic acid, or a polyfunctional ester forming alcohol such as 
glycerin, trimethylolpropane or pentaerythritol in an amount of 1.0 mol % 
or less, preferably 0.5 mol % or less, more preferably 0.3 mol % or less 
as a ramification component. 
The polyester used in the present invention preferably has an intrinsic 
viscosity of 0.6 to 1.2. When the intrinsic viscosity is lower than 0.6, 
sufficient properties cannot be obtained and when the intrinsic viscosity 
is higher than 1.2, melt viscosity increases and flowability lowers, 
thereby impairing moldability disadvantageously. The intrinsic viscosity 
is a value measured at 35.degree. C. in orthochlorophenol. 
The polycarbonate is preferably a polycarbonate comprising a bisphenol such 
as 2,2-bis(4-hydroxyphenyl)propane as a diol component. 
The fluororesin is, for example, a copolymer of tetrafluoroethylene and 
perfluoropropylene. 
The acryl resin is, for example, polymethyl methacrylate or polymethyl 
acrylate. 
The thermoplastic polyurethane is a polyurethane comprising a polyester or 
a polyether as a soft segment and a polyester as a hard segment. 
The polyamide is, for example, nylon 4, nylon 6, nylon 6,6 or nylon 12. 
The polyacetal is, for example, polyoxymethylene. 
The polysulfone is, for example, polyphenyl sulfone. 
Out of these, preferred are a polyester, polystyrene, polymethyl 
methacrylate, styrene/acrylonitrile copolymer, 
acrylonitrile/butadiene/styrene copolymer, methyl 
methacrylate/butadiene/styrene copolymer, styrene/methyl 
methacrylate/acrylonitrile copolymer, polyproylene and polyethylene. 
Polymer (B) 
The polymer (B) used in the present invention has a surface resistivity of 
10.sup.8 to 10.sup.11 .OMEGA.. The surface resistivity is a value measured 
at a voltage of 500 V. 
The polymer used in the present invention has an apparent melt viscosity at 
an apparent shear rate at 260.degree. C. of 1,000 sec.sup.-1 of 10 to 
1,000 Pa.multidot.s and a ratio of the above apparent melt viscosity to 
the apparent melt viscosity of the thermoplastic resin under the same 
condition (apparent shear rate at 260.degree. C. of 1,000 sec.sup.-1) of 
0.01 to 1.3. The apparent melt viscosity is preferably 10 to 500 
Pa.multidot.s and the ratio is preferably 0.01 to 0.8. 
If the melt viscosity falls within the above range, when compatibility 
between the thermoplastic resin (A) and the polymer (B) used in the 
present invention is essentially low and the thermoplastic resin (A) and 
the polymer (B) having different melt viscosities are both molten, mixed 
and molded, the polymer (B) is dispersed in the form of a stripe (a short 
diameter of 1 .mu.m or less and a long diameter of 1 .mu.m or more with an 
aspect ratio of 3 or more in a thermoplastic resin phase within a surface 
area of 20 .mu.m, preferably with an aspect ratio of 50 or more) or a net, 
whereby the polymer (B) can intersect a fibrous conductive filler (200 to 
300 .mu.m in length in the case of CF) and a fine conductive path is 
formed in the surface portion of a molded product. This is the reason why 
extremely excellent antistatic properties are provided. If the ratio is 
outside the above range, the continuous phase of the polymer (B) is not 
formed, the possibility of intersection between the polymer (B) and the 
fibrous conductive filler lowers, and antistatic properties deteriorate. 
The melting point of the polymer (B) is 100.degree. C. or higher, 
preferably 150.degree. C. or higher. When a polymer having a melting point 
lower than 100.degree. C. is used and compounded with an engineering 
plastic such as a polyester, there is a problem with heat resistance and 
sufficient antistatic properties cannot be provided. 
The polymer (B) used in the present invention is preferably a polyethylene 
glycol-based polyamide copolymer, polyethylene glycol methacrylate 
copolymer, poly(ethylene oxide/propylene oxide) copolymer, polyethylene 
glycol-based polyesteramide, polyethylene glycol-based polyester 
elastomer, poly(epichlorohydrin/ethylene oxide) copolymer or 
polyetheresteramide derived from an ethylene oxide adduct of a bisphenol 
with a polyamide having a carboxyl group at both terminals. 
Out of these polymers, a polyether ester amide derived (polymerized) from 
an ethylene oxide adduct of a bisphenol with a polyamide having a carboxyl 
group at both terminals is particularly preferred. 
The polyamide having a carboxyl group at both terminals of the polyether 
ester amide preferably has a number average molecular weight of 500 to 
5,000, more preferably 500 to 3,000. When the number average molecular 
weight is less than 500, the heat resistance of the polyether ester amide 
itself lowers and when the number average molecular weight is more than 
5,000, reactivity lowers, thereby boosting the production cost of the 
polyether ester amide. 
The ethylene oxide adduct of the bisphenol of the polyether ester amide 
preferably has a number average molecular weight of 1,600 to 3,000 and the 
number of mols of the ethylene oxide is preferably 32 to 60. When the 
number average molecular weight is less than 1,600, antistatic properties 
are insufficient and when the number average molecular weight is more than 
3,000, reactivity lowers, thereby boosting the production cost of the 
polyether ester amide. 
A method of producing the polyether ester amide is not particularly limited 
and known methods can be used. For instance, a polyamide having a carboxyl 
group at both terminals is formed by reacting an amide forming monomer 
with a dicarboxylic acid, an ethylene oxide adduct of a bisphenol is added 
to the polyamide, and a polymerization reaction is carried out at a high 
temperature and a reduced pressure. 
In the present invention, the amount of the polymer (B) is 10 to 200 parts 
by weight, preferably 10 to 100 parts by weight, more preferably 15 to 30 
parts by weight based on 100 parts by weight of the thermoplastic resin. 
When the amount is larger than 200 parts by weight, mechanical strength 
and productivity lower and when the amount is smaller than 10 parts by 
weight, the voltage half-attenuation time is long and sufficient 
antistatic properties cannot be obtained. 
Fibrous Conductive Filler 
The fibrous conductive filler having a volume resistivity of 100 .OMEGA.cm 
(C) or less used in the present invention is preferably a carbon fiber, 
metal fiber, metal-based whisker, ceramic-based whisker or organic 
polymer-based whisker. Preferred examples of the carbon fiber include 
carbon fiber and nickel coated carbon fiber. When the fibrous conductive 
filler is a metal fiber, the metal fiber is preferably produced by a wire 
drawing, melt extrusion, melt extraction, cutting or plating method and 
made from Fe, Ni, Cu, Al, Pb, SUS (chromium steel) or Zn. Out of these, 
carbon fiber is the most suitable to provide high rigidity and antistatic 
properties which are requirements for a large carrier jig for use in the 
electronic field. 
The amount of the fibrous conductive filler having a volume resistivity of 
100 .OMEGA.cm or less (C) used in the present invention is 1 to 100 parts 
by weight, preferably 10 to 30 parts by weight based on 100 parts by 
weight of the thermoplastic resin. When the amount is larger than 100 
parts by weight, extrudability and moldability lower, which is 
economically disadvantageous and not practical. when the amount is smaller 
than 1 part by weight, rigidity required for a large carrier jig cannot be 
provided and the effect of leaking a charge is small disadvantageously. 
When the carbon fiber is used in an amount of more than 100 parts by 
weight, fine waste carbon is produced at the time of molding, which may 
cause the contamination of a silicon wafer. 
Use of carbon black or metal powders is not preferred from the view point 
of preventing the contamination of a silicon wafer, and a combination of 
the fibrous conductive filler of the present invention which can leak a 
charge effectively without the contamination of a silicon wafer and a heat 
resistant antistatic polymer is useful. 
When a resin composition comprising a polyether ester amide and CF out of 
the resin compositions of the present invention is used in a silicon wafer 
carrier jig, metal impurities rarely ooze out to the surface of the 
silicon wafer carrier jig at the time of a heat treatment and hence, the 
surface of a silicon wafer is not stained by transfer. 
For instance, when a carbon fiber is used alone, differences in antistatic 
properties occur on the surface of a carrier jig for use in the electronic 
field. This is probably because the dispersibility of the carbon fiber is 
low, the carbon fiber is not distributed properly due to the shape of the 
carrier jig, and a portion having a low distribution density of the carbon 
fiber is produced. 
When a heat resistant antistatic polymer having a specific melt viscosity 
and a fibrous conducive filler are used in combination in the present 
invention, the leakage of a charge is greatly promoted. That is, by 
causing the antistatic polymer to be existent in a portion where the 
fibrous conductive filler is not dispersed which is produced dependent on 
the shape of a molded product, the leakage of a charge is greatly 
promoted. Further, this resin composition can greatly reduce differences 
in antistatic properties which cannot be attained by a conventional resin 
composition, particularly differences in the antistatic properties of a 
product molded thereof. 
Studies conducted by the inventor of the present invention have made it 
clear that it is possible to provide a thermoplastic resin composition 
which can obtain the same excellent destaticizing properties as the first 
composition of the present invention even when a very fine and short 
carbon fiber is used in the above first composition of the present 
invention in place of the above polymer (B), can achieve excellent 
destaticizing properties when the content of the polymer (B) is reduced 
and the above polymer (B) and the above carbon fiber are used in 
combination, and have more excellent physical properties than the first 
composition of the present invention. 
That is, according to the present invention, secondly, there is provided a 
destaticizing resin composition (may be referred to as "second composition 
of the present invention" hereinafter) which is a compound comprising: 
(A) 100 parts by weight of a thermoplastic resin; 
(B) 1 to 30 parts by weight of a carbon fiber having a diameter of 1 nm to 
1 .mu.m, a length of 1 .mu.m to 10 mm and a volume resistivity of less 
than 1 .OMEGA.cm; and 
(C) 1 to 100 parts by weight of a fibrous conductive filler having a volume 
resistivity of 100 .OMEGA.cm or less. 
According to the present invention, thirdly, there is provided a 
destaticizing resin composition (may be referred to as "third composition 
of the present invention" hereinafter) which is a compound comprising: 
(A) 100 parts by weight of a thermoplastic resin; 
(B) 0.01 to 150 parts by weight of a polymer having a surface resistivity 
measured at 500 V of 10.sup.8 to 10.sup.11 .OMEGA., a melting point of 
100.degree. C. or higher, an apparent melt viscosity at an apparent shear 
rate at 260.degree. C. of 1,000 sec.sup.-1 of 10 to 1,000 Pa.multidot.s, 
and a ratio of the above apparent melt viscosity to the apparent melt 
viscosity of the above thermoplastic resin at an apparent shear rate at 
260.degree. C. of 1,000 sec.sup.-1 of 0.01 to 1.3; 
(B') 0.01 to 28 parts by weight of a carbon fiber having a diameter of 1 nm 
to 1 .mu.m, a length of 1 .mu.m to 10 mm and a volume resistivity of less 
than 1 .OMEGA.cm; and 
(C) 1 to 100 parts by weight of a fibrous conductive filler having a volume 
resistivity of 100 .OMEGA.cm or less. 
As for what is not described of the second composition of the present 
invention herein, it should be understood that a description of the first 
composition is directly applied to the second composition of the present 
invention. 
Carbon Fiber (B') 
In the present invention, a carbon fiber (B') having a diameter of 1 nm to 
1 .mu.m, a length of 1 .mu.m to 10 mm and a volume resistivity of less 
than 1 .OMEGA.cm is used. The carbon fiber preferably has a diameter of 1 
nm to 500 nm. 
When the diameter of the carbon fiber (B') is smaller than 1 nm, the carbon 
fiber is dispersed too finely, and targeted antistatic properties cannot 
be provided. When the diameter is larger than 1 .mu.m, dispersion becomes 
non-uniform, the effect of fusing the carbon fiber with the fibrous 
conductive filler (C) is not obtained, and targeted antistatic properties 
cannot be provided. When the length of the carbon fiber is smaller than 1 
.mu.m, the carbon fiber is dispersed too finely, and targeted antistatic 
properties cannot be provided. When the length is larger than 10 mm, 
dispersion becomes nonuniform, the effect of fusing the carbon fiber with 
the fibrous conductive filler (C) cannot be obtained, and targeted 
antistatic properties cannot be provided. When the volume resistivity of 
the carbon fiber is more than 1 .OMEGA.cm, the effect of fusing the fiber 
carbon with the fibrous conductive filler (C) cannot be obtained, and 
sufficient antistatic properties cannot be provided. 
This carbon fiber (B') is preferably a vapor phase process carbon fiber 
produced by a vapor phase process. Methods for producing this vapor phase 
process carbon fiber include a substrate method (JP-A 60-27700) and a 
flotation method (JP-A 62-78217). Carbon fibers produced by these methods 
include a carbon fiber treated at a temperature higher than 2,000.degree. 
C. These carbon fibers may be used in combination of two or more. The 
disclosures of JP-A 60-27700 and JP-A 62-78217 are cited herein as part of 
a description of the present invention. 
The amount of the carbon fiber (B') used in the present invention is 1 to 
30 parts by weight, preferably 1 to 10 parts by weight based on 100 parts 
by weight of the thermoplastic resin. When the amount is smaller than 1 
part by weight, the effect of fusing the carbon fiber with the fibrous 
conductive filler (C) is not exhibited and the effect of leaking a charge 
is small. When the amount is larger than 30 parts by weight, extrusion 
ability, moldability and mechanical property are reduced. Further, costs 
are too high, which is not practical. 
When a carbon fiber is used in the second composition of the present 
invention as the fibrous conductive filler, a carbon fiber having a 
diameter of more than 1 .mu.m is preferably used to obtain the effect of 
fusing the carbon fiber with the carbon fiber (B') and improve the effect 
of leaking a charge. 
As for what is not described of the third composition of the present 
invention herein, it should be understood that the description of the 
first composition is directly applied to the third composition of the 
present invention. 
The third composition comprises both the polymer (B) and the carbon fiber 
(B'). In this case, the content of the polymer (B) is 0.01 to 150 parts by 
weight, preferably 1 to 50 parts by weight based on 100 parts by weight of 
the thermoplastic resin. 
The carbon fiber (B') is used in an amount of 0.01 to 28 parts by weight, 
preferably 0.1 to 9 parts by weight based on the same standard. 
The thermoplastic resin composition of the present invention (including the 
first, second and third compositions of the present invention hereinafter 
unless otherwise stated) may contain various additives including a release 
agent such as montan wax, polyethylene wax or silicon oil, flame 
retardant, flame retardant aid, thermal stabilizer, ultraviolet absorber, 
pigment and dye in limits not prejudicial to the object of the present 
invention. A thermoset resin such as a phenol resin, melamine resin, 
silicon resin or epoxy resin; or a soft thermoplastic resin such as 
ethylene/vinyl acetate copolymer, polyester elastomer or epoxy modified 
polyolefin may be added in limits not prejudicial to the object of the 
present invention. Other filler such as talc, kaolin, Wollastonite, clay, 
silica, sericite, titanium oxide, carbon black, graphite, metal powder, 
glass bead, glass balloon, glass flake, glass powder or glass fiber may be 
further added. 
Composition Production Method 
The thermoplastic resin composition used in the present invention is 
obtained by blending the components (A), (B) and/or (B') and (C) in 
accordance with a desired method. These components are generally 
preferably dispersed uniformly, all or part of these components are 
preferably dispersed uniformly at the same time, or all or part of these 
components are mixed together by a mixer such as a blender, kneader, 
banbury mixer, roll or extruder at the same time or separately to prepare 
a homogenous mixture. 
Further, a dry blended composition may be molten and kneaded with a heated 
extruder to be made homogeneous and extruded into a wire form which is cut 
to a desired length to be granulated. 
Carrier Jig For Use In Electronic Field 
The thermoplastic resin composition of the present invention is suitable as 
a raw material for a carrier jig for use in the electronic field. 
Illustrative examples of the carrier jig include silicone wafer carrier, 
silicone wafer carrier box, silicone wafer press bar, IC tray, carrier for 
liquid crystal base and carrier jig for HDD and LCD-related parts. 
Therefore, according to the present invention, there is also provided a 
carrier jig for use in the electronic field which is made from the 
destaticizing thermoplastic resin composition of the present invention. 
Stated more specifically, in the carrier jig of the present invention, 
differences (relationship among average values, minimum values and maximum 
values) in saturation voltage and voltage half-attenuation time when a 
surface area measuring 125 mm in length and 150 mm in width of the carrier 
jig is measured at an application voltage of 10 kV satisfy the following 
expressions at the same time. 
EQU E.sub.max (V)-100 (V).ltoreq.E.sub.ave (V).ltoreq.E.sub.min (V)+100 (V) 
EQU T.sub.max (s)-5 (s).ltoreq.T.sub.ave (s).ltoreq.T.sub.min (s)+5 (s) 
wherein E.sub.ave, E.sub.max and E.sub.min are average, maximum and minimum 
values of saturation voltage and T.sub.ave, T.sub.max and T.sub.min are 
average, maximum and minimum values of voltage half-attenuation time, 
respectively. 
The above expressions are established when a surface area measuring 125 mm 
in length and 150 mm in width to be measured is divided into 9 sections 
and each section is measured. The above expressions are established for 
the surface area to be measured, that is, a desired flat portion of the 
resin surface forming the carrier jig. 
Owing to this feature, the adhesion of floating particles by static 
electricity can be greatly reduced over the entire surface of the carrier 
jig and poor outer appearance caused by the particles (so-called "lack of 
pattern") can be reduced. 
Although there is a possibility that the above feature can be attained by 
using a large amount of carbon black or combining a non-carbon-based 
conductive agent or a carbon-based conductive agent, it is not preferred 
to use the carbon black or the agents in a carrier jig for use in the 
electronic field because waste carbon is produced at the time of molding 
or use. 
The carrier jig of the present invention has antistatic properties and 
mechanical strength, that is, rigidity with a flexural modulus of 5,000 
MPa or more which is required for a large carrier jig for use in the 
electronic field. Due to these physical properties, there can be obtained 
a silicon wafer carrier which has at least one groove for holding a wafer 
and can be incorporated into full automation, which will be required in 
the near future. 
A combination of the fibrous conductive filler and the antistatic polymer 
described in the present invention can be applied in the field of 
electromagnetic shielding. A combination of a nickel coated carbon fiber 
and PEEA is such an example. 
When the polymer (B) is used to produce a carrier jig for use in the 
electronic field which promotes the leakage of a charge and has small 
differences in saturation voltage and voltage half-attenuation time and 
excellent destaticizing properties, molding conditions for dispersing the 
polymer (B) in the form of a stripe or net in the surface portion of a 
molded product must be employed, that is, molding must be carried out at a 
higher speed and a higher voltage than when molding an ordinary polyester. 
For instance, when the Mitsubishi 80 MSP injection molding machine is used, 
molding is preferably carried out at a cylinder temperature of 250.degree. 
C., a mold temperature of 60.degree. C. and an injection rate/injection 
pressure of 40 to 60%. The thus obtained carrier jig for use in the 
electronic field has excellent permanent antistatic properties. 
The following examples are given to further illustrate the present 
invention. 
Raw materials and evaluation methods used in the examples are as follows. 
1. raw materials 
The following raw materials were used. 
polybutylene terephthalate (PBT): TRB-QK of Teijin Limited 
polystyrene (PS): Stylon 666 of Asahi Chemical Industry Co., Ltd. 
acrylonitrile/butadiene/styrene copolymer (ABS): Stylac 101 of Asahi 
Chemical Industry Co., Ltd. 
polycarbonate (PC): AD5509 of Teijin Kasei Co., Ltd. 
polyether ester amide (PEEA): Pelestat 6321 of Sanyo Chemical Industries, 
Ltd. having a surface resistivity of 1.times.10.sup.9 .OMEGA. and a 
melting point of 203.degree. C. 
high-molecular antistatic agent: SD100 of Mitsui Dupont Chemical Co., Ltd. 
having a surface resistivity of 1.times.10.sup.8 .OMEGA. and a melting 
point of 92.degree. C. 
high-molecular antistatic agent: Leorex AS-170 of Daiichi Kogyo Seiyaku 
Co., Ltd. having a surface resistivity of 7.times.10.sup.6 .OMEGA. and a 
melting point of 80.degree. C. 
polyether ester: TRB-EKV of Teijin Limited having a surface resistivity of 
1.times.10.sup.10 .OMEGA. and a melting point of 170.degree. C. 
sodium dodecylbenzenesulfonate (DBS-Na): TPL456 of Takemoto Yushi Co., Ltd. 
carbon fiber (CF): HTA-C6-SR of Toyo Rayon Co., Ltd. having a volume 
resistivity of 1.5.times.10.sup.-3 .OMEGA.cm, a diameter of 7 .mu.m and a 
length of 6 mm 
nickel coated carbon fiber: MC(I)HTA-C6-SR of Toyo Rayon Co., Ltd. having a 
volume resistivity of 7.5.times.10.sup.-5 .OMEGA.cm 
stainless fiber: Tafmic Fiber of Tokyo Seiko Co., Ltd. having a volume 
resistivity of 7.5.times.10.sup.-5 .OMEGA.cm 
conductive potassium titanate whisker: Dentole WK300 of Ohtsuka Kagaku Co., 
Ltd. having a volume resistivity of 1 to 10 .OMEGA.cm, a diameter of 0.4 
to 0.7.mu.m, a length of 10 to 20 .mu.m 
conductive potassium titanate whisker: Dentole WK200B of Ohtsuka Kagaku 
Co., Ltd. having a volume resistivity of 0.1 to 1 .OMEGA.cm 
needle-like conductive titanium oxide: FT1000 of Ishihara Sangyo Co., Ltd. 
having a volume resistivity of 10 to 15 .OMEGA.cm 
super fine vapor phase process carbon fiber (VGCF1): VGCF of Showa Denko 
K.K. having a volume resistivity of 1.0.times.10.sup.-2 .OMEGA.cm, a 
diameter of 0.2 .mu.m and a length of 20 .mu.m 
super fine vapor phase process carbon fiber (VGCF2): Micrographite fibril 
BN1100 of Hypilion Katarisys Co., Ltd. having a volume resistivity of 
1.times.10.sup.-2 .OMEGA.cm, a diameter of 15 nm and a length of 10 to 20 
.mu.m 
2. antistatic properties (resistivity, saturation voltage and voltage 
half-attenuation time): 
Antistatic properties were evaluated based on saturation voltage measured 
at an application voltage of 10 kV using an Honest meter (Static H-0110 of 
Shishido Seidenki Co., Ltd.), voltage half-attenuation time and surface 
resistivity measured using a ultra-insulation resistance testor (SM-10E of 
Toa Denpa Kogyo Co., Ltd.). 
Low resistivity was measured in accordance with JIS K7194. 
The voltage half-attenuation time and the surface resistivity were measured 
at an ambient temperature of 23.degree. C. and a relative humidity of 50% 
after a sample was kept at a temperature of 23.degree. C. and a relative 
humidity of 50% for 24 hours. 
To measure differences in saturation voltage and voltage half-attenuation 
time, a test piece (125.times.150 mm, thickness of about 5 mm) was divided 
into 9 small sections, each measuring about 41.7 mm in length.times.50 mm 
in width, and each of the sections was measured. 
3. mechanical strength: 
A tensile test was conducted in accordance with ASTM D638 and a flexural 
test was conducted in accordance with ASTM D790. 
4. volume resistivity of fibrous conductive filler: 
The volume resistivity was measured in accordance with JIS-R-7601. When 
this method was not used, a powder produced at a pressure of 100 
kg/cm.sup.2 was measured. 
5. surface resistivity of antistatic polymer: 
The surface resistivity was measured using a ultra-insulation resistance 
testor (SM-10E of Toa Denpa Kogyo Co., Ltd.) (measurement voltage of 500 
V). This measurement was carried out at an ambient temperature of 
23.degree. C. and a relative humidity of 50% after a sample was kept at a 
temperature of 23.degree. C. and a relative humidity of 50% for 24 hours. 
6. melting point of antistatic polymer: 
The melting point was measured by DSC (of T. A. Instrument Japan Co., 
Ltd.). 
7. melt viscosity ratio: 
The melt viscosity ratio is defined by the following expression. 
(melt viscosity ratio)=(melt viscosity of antistatic polymer)/(melt 
viscosity of thermoplastic resin such as PBT) 
The measurement conditions include a temperature of 260.degree. C. and a 
shear rate of 1,000 sec.sup.-1. Leograph 2002 of Getfelt of Germany was 
used to measure melt viscosity. 
8. washing: 
The surface of a sample was manually washed with sponge for 3 minutes using 
a neutral detergent (1.5 ml/l of aqueous solution of Mama Lemon) and then 
with hot purified water (60.degree. C.) for 3 minutes, dried with an air 
blow and in an oven at 80.degree. C. for 10 minutes and kept at a 
temperature of 23.degree. C. and a relative humidity of 50% for 24 hours. 
EXAMPLES 1 TO 13 AND COMATIVE EXAMPLES 1 TO 20 
The above raw materials were dry blended uniformly in a weight ratio shown 
in Tables 2, 4 and 5, molten and kneaded at a cylinder temperature of 180 
to 310.degree. C., a screw revolution speed of 160 rpm and a discharge 
rate of 40 kg/h using a vented double-screw extruder having a screw 
diameter of 44 mm, and a thread discharged from a dice was cooled and cut 
to obtain a pellet for molding. 
A silicon wafer carrier and a test piece for the evaluation of mechanical 
properties were formed from this pellet by injection molding under 
conditions including an injection pressure of 750 kg/cm.sup.2, an 
injection rate of 70 cm.sup.3 /sec, a cooling time of 15 sec and a total 
molding cycle of 25 sec. Further, the side portion of this silicon wafer 
carrier was cut to a desired size to carry out the above evaluation. 
The antistatic agents used are shown in Table 1, out of which, 
high-molecular antistatic agents which can produce an effect when they are 
applied in PBT, that is, have high heat stability and can be dispersed in 
PBT in the form of a net or stripe are PEEA and TRB-EKV. 
Further, The evaluation results are shown in Table 2. 
TABLE 1 
______________________________________ 
antistatic 
melt viscosity at 260.degree. C. 
melt viscosity 
melting point 
polymer and 1,000 sec.sup.-1 (PA.multidot.S) ratio to TRB-QK (.degree. 
C.) 
______________________________________ 
PEEA 56 0.30 203 
TRB-EKV 54 0.30 171 
SD100 236 1.32 92 
Leorex could not be measured 1.32 or more 80 
SD-170 due to increased 
viscosity 
______________________________________ 
TABLE 2 
__________________________________________________________________________ 
Composition (wt %) untreated 
CF saturation 
voltage half- 
tensile 
flexural 
elastic 
(HTAC voltage attenuation time strength strength modulus 
PBT PEEA SD100 Leorex 6SR) .OMEGA./.quadrature.* (KV) (sec) (MPa) (MPa) 
(MPa) 
__________________________________________________________________________ 
Ex. 1 
77 15 8 1E9 0.03 1.7 73 90 5200 
Ex. 2 79 15 6 1E9 0.07 3 63 82 4400 
C.Ex. 1 85 15 4E12 1.5 3 44 65 1900 
C.Ex. 2 96 4 3E16 1.3 300 or more 82 125 4300 
C.Ex. 3 94 6 2E14 0.7 300 or more 95 145 5200 
C.Ex. 4 92 8 1E14 0.5 300 or more 113 170 6600 
C.Ex. 5 85 15 4.8E13 1.19 300 or more -- 36 2200 
C.Ex. 6 85 15 4.9E13 1.18 300 or more 46 66 2000 
C.Ex. 7 80 10 10 1.4E9 0.24 300 or more 66 89 7600 
C.Ex. 8 70 10 20 1.6E9 0.07 240 79 110 12400 
C.Ex. 9 70 15 15 2.0E4 0.12 213 91 120 8600 
C.Ex. 10 70 10 20 2.9 0.11 177 102 135 11200 
C.Ex. 11 70 30 28 0.05 28 172 260 17100 
C.Ex. 12 80 20 3.3E12 1.4 1.9 42 60 2000 
C.Ex. 13 
70 30 could not be produced 
__________________________________________________________________________ 
Note) *For example. "1E9" means 1 .times. 10.sup.9 (This shall apply 
hereinafter). 
As is evident from Table 2, in compositions comprising PEEA and CF 
(Examples 1 and 2), the effect of fusing PEEA with carbon fiber is 
exhibited markedly, the saturation voltage is 1 kV or less, and the 
voltage half-attenuation time is 10 sec or less. 
In contrast, in compositions comprising Leorex and CF (Comparative Examples 
9 and 10) and compositions comprising SD100 and CF (Comparative Examples 7 
and 8), antistatic properties are insufficient. 
In compositions comprising an antistatic polymer and no CF (Comparative 
Examples 1, 5, 6, 12 and 13) and composition comprising CF and no 
antistatic polymer (Comparative Examples 2, 3, 4 and 11), the saturation 
voltage could not be reduced to 1 kV or less and the voltage 
half-attenuation time could not be reduced to 10 sec or less even by 
increasing the content of the antistatic polymer or CF. 
Since the composition of Comparative Example 1 has a surface resistivity of 
10.sup.12 .OMEGA. or more, a saturation voltage of 1 kV or more and a 
flexural modulus of 2,000 MPa or less, it is not suitable for use as a 
large carrier jig which requires high rigidity. 
Although the compositions of Comparative Examples 2 to 4 have a flexural 
modulus of 4,000 to 6,000 MPa, they have a voltage half-attenuation time 
of 300 sec or more and may have a problem with antistatic properties as a 
large carrier jig. 
The compositions comprising PEEA and carbon fiber of Examples 1 and 2 have 
antistatic properties as a carrier jig for use in the electronic field and 
high rigidity for a large carrier jig. 
Differences in antistatic properties, saturation voltage and voltage 
half-attenuation time, on molded products of Example 1, Comparative 
Example 1, Comparative Example 4 and Comparative Example 11 have been 
studied. 
The side portion (125.times.150 mm, thickness of about 5 mm) of a molded 
silicon wafer carrier was equally divided into 9 small sections, each 
measuring about 41.7 mm in length.times.50 mm in width, as shown in FIG. 1 
and the saturation voltage and voltage half-attenuation time of each 
section were measured to study differences in saturation voltage and 
voltage half-attentuation time. 
Table 3 shows differences in saturation voltage and voltage 
half-attenuation time. 
TABLE 3 
__________________________________________________________________________ 
C.Ex. 1 C.Ex. 4 C.Ex. 11 Ex. 1 
saturation 
voltage half- 
saturation 
voltage half- 
saturation 
voltage half- 
saturation 
voltage half- 
divided voltage attenuation time voltage attenuation time voltage 
attenuation time voltage 
attenuation time 
portion (V) (sec) (V) (sec) (V) (sec) (V) (sec) 
__________________________________________________________________________ 
1 660 0.7 480 saturation 
50 26 0 0.0 
2 740 1.0 450 voltage 40 57 0 0.0 
3 680 0.8 500 on the 50 25 0 0.0 
4 510 0.5 590 left is 50 28 30 0.1 
5 690 1.7 430 kept and 40 54 0 0.0 
6 480 0.5 580 does not 50 23 30 0.1 
7 820 1.4 640 attenuate 50 21 50 0.4 
8 960 2.7 420 &gt;300 20 6 20 0.1 
9 1050 4.0 580 40 19 50 0.4 
__________________________________________________________________________ 
As is evident from Table 3, in the composition comprising PEEA and CF of 
Example 1, differences in voltage half-attenuation time and saturation 
voltage are smaller than those of the composition comprising CF and no 
antistatic polymer of Comparative Example 4. 
It is understood that differences in voltage half-attenuation time and 
saturation voltage on the flat plate of the composition comprising CF and 
PEEA of Example 1 are smaller and antistatic properties are more uniformly 
provided than those of the composition comprising PEEA and no CF of 
Comparative Example 1. 
Further, in the composition comprising CF and no antistatic polymer of 
Comparative Example 11 which has the total of volume fractions of PEEA and 
CF, the initial saturation voltage can be reduced but the voltage 
half-attenuation time cannot be reduced and differences cannot be 
eliminated. 
Thus, the composition of the present invention can reduce differences in 
antistatic properties on the surface of a molded product. 
The antistatic properties of a carrier jig for use in the electronic field 
must not be changed by washing and temperature variations at the time of 
transportation. Changes in antistatic properties at the time of washing 
and annealing were measured. The results are shown in Table 4. 
TABLE 4 
__________________________________________________________________________ 
Composition (wt %) untreated 160.degree. C. .times. 5 hours 
water treatment 
saturation 
voltage half- 
saturation 
voltage half- 
saturation 
voltage half- 
TRB DBS- HTAC 
voltage attenuation 
time voltage 
attenuation time 
voltage attenuation 
time 
QK PEEA EKV Na 6SR (KV) (sec) (KV) (sec) (KV) (sec) 
__________________________________________________________________________ 
Ex. 3 
50 40 10 0 0 0 0 0 0 
Ex. 4 30 60 10 0 0 0 0 0 0 
Ex. 5 47 7 46 0 0 0 0 0 0 
Ex. 6 25 50 25 0 0 0 0 0 0 
C.Ex. 14 80 5 15 0 1 0.02 3.7 0.11 396 
C.Ex. 15 75 5 20 0.03 0.82 0.03 0.60 0.06 92 
C.Ex. 16 75 10 15 0 0 0.01 1.87 0.06 307 
C.Ex. 17 
50 40 10 could not be produced 
__________________________________________________________________________ 
As means of reducing saturation voltage and voltage half-reduction time, a 
combination of a conductive filler and a low-molecular antistatic agent is 
used (Comparative Examples 14 to 17). However, as is obvious from Table 4, 
according to this method, antistatic properties are greatly deteriorated 
by 5 hours of annealing at 160.degree. C. and washing. 
In contrast, a carrier jig for use in the electronic field made from the 
composition of the present invention (Examples 3 to 6) does not suffer 
from deterioration in characteristic properties and has permanent 
antistatic properties. 
The results obtained when a conductive filler other than CF (HTA-C6-SR) was 
compounded are shown in Table 5. 
TABLE 5 
__________________________________________________________________________ 
Composition (wt %) untreated 160.degree. C. .times. 5 
hours 
CF saturation 
voltage half- 
saturation 
voltage half- 
MC stainless wk 
wk FT voltage 
attenuation time 
voltage attenuation 
time 
QK CF (1) steel 300 200B 1000 PEEA .OMEGA./.quadrature. (KV) (sec) (KV) 
(sec) 
__________________________________________________________________________ 
Ex. 7 
70 10 20 1.0E3 
0 0 0 0 
Ex. 8 70 10 20 1.3E13 0.05 0.47 0 0 
Ex. 9 72 8 20 4.3E11 0.62 0.52 0.66 0.52 
Ex. 10 70 10 20 2.1E11 0.48 0.29 0.32 0.19 
Ex. 11 70 10 20 1.7E11 0.42 0.28 0.30 0.20 
Ex. 12 70 10 20 4.1E11 0.58 0.44 0.55 0.40 
Ex. 13 60 30 10 2.7E10 0.03 0.74 0.01 0.098 
C.Ex. 18 70 30 7.6E10 0.15 129 0.19 240 
C.Ex. 19 90 10 4.2E13 1.26 &gt;300 1.25 &gt;300 
C.Ex. 20 
70 30 could not be produced 
__________________________________________________________________________ 
The same effect is observed when nickel coated carbon fiber, stainless 
fiber and various whiskers shown in Table 5 are used (Examples 7 to 13). 
Like carbon fiber shown in Table 2, when only a conductive filler is used, 
both the voltage half-attenuation time and saturation voltage cannot be 
reduced (Comparative Examples 18 to 20). 
EXAMPLES 14 TO 22 AND COMATIVE EXAMPLES 21 TO 25 
The antistatic agents used are shown in Table 6. Of these, high-molecular 
antistatic agents which can produce an effect when they are applied in 
thermoplastic resins other than PBT, that is, have high heat stability and 
can be dispersed in thermoplastic resins in the form of a net or stripe 
are PEEA and TRB-EKV. 
TABLE 6 
__________________________________________________________________________ 
Antistatic 
Melt viscosity at 260.degree. C. 
Melt viscosity 
Melt viscosity 
Melting point 
polymer and 1,000 sec.sup.-1 (PA.multidot.S) ratio to PS ratio to ABS 
(.degree. C.) 
__________________________________________________________________________ 
PEEA 56 0.82 0.34 203 
TRB-EKV 54 0.79 0.32 171 
Leorex SD-170 Could not be measured 1.30 or more 1.30 or more 80 
due to increased viscosity 
__________________________________________________________________________ 
Various components were mixed in a weight ratio specified In Table 7, Table 
9 and Table 10, and the resulting mixtures were evaluated In the same 
manner as in Examples 1 to 13. 
Table 7 shows the evaluation results. 
TABLE 7 
__________________________________________________________________________ 
Composition (wt %) untreated 
CF saturation 
voltage half- 
(HTAC voltage attenuation time 
PS ABS PEEA Leorex 6SR) .OMEGA./.quadrature. (KV) (sec) 
__________________________________________________________________________ 
Ex. 14 
77 15 8 5E + 8 
0.02 0.13 
Ex. 15 77 15 8 2E + 3 0.03 0.66 
C.Ex. 21 70 20 10 3E + 2 0.16 200 
C.Ex. 22 70 30 2E + 9 0.10 &gt;600 
__________________________________________________________________________ 
As is evident from Table 7, in the compositions comprising PEEA and CF of 
Examples 14 and 15, the effect of fusing PEEA with carbon fiber is 
exhibited markedly, the saturation voltage is 1 kV or less, and the 
voltage half-attenuation time is 10 sec or less. 
In contrast, in the composition comprising Leorex and CF of Comparative 
Example 21, antistatic properties are insufficient. 
In the composition comprising CF and no antistatic polymer of Comparative 
Example 22, the saturation voltage cannot be reduced to 1 kV or less and 
the voltage half-attenuation time cannot be reduced to 10 sec or less 
simply by increasing the content of CF. 
The compositions comprising PEEA and carbon fiber of Examples 14 and 15 
show a flexural strength of 70 MPa and a flexural modulus of 4,300 MPa and 
have antistatic properties as a carrier jig for use in the electronic 
field and high rigidity required for a large carrier jig. 
Differences in antistatic properties, that is, saturation voltage and 
voltage half-attenuation time, on the surfaces of molded products of 
Examples 15 and Comparative Example 22 were studied. 
The side portion (125.times.150 mm, thickness of about 5 mm) of a molded 
silicon wafer carrier was equally divided into 9 small sections, each 
measuring about 41.7 mm in length.times.50 mm in width, as shown in FIG. 1 
and the saturation voltage and voltage half-attenuation time of each 
section were measured to study differences in saturation voltage and 
voltage half-attenuation time. 
Table 8 shows differences in saturation voltage and voltage 
half-attenuation time. 
TABLE 8 
______________________________________ 
Ex.15 C.Ex.22 
voltage voltage 
half- half- 
saturation attenuation saturation attenuation 
divided voltage time voltage time 
portion (V) (sec) (V) (sec) 
______________________________________ 
1 10 0.16 80 saturation 
2 0 0.00 40 voltage 
3 20 0.16 60 on the 
4 20 0.13 60 left is 
5 0 0.00 30 kept and 
6 20 0.26 50 does not 
7 20 0.20 40 attenuate 
8 0 0.00 30 
9 10 0.19 50 
______________________________________ 
As is evident from Table 8, in the composition comprising CF and no 
antistatic polymer and having the total of volume fractions of PEEA and CF 
of Comparative Example 22, the initial saturation voltage can be reduced 
but the voltage half-attenuation time cannot be shortened and differences 
cannot be eliminated. 
Thus, the composition of the present invention can eliminate differences in 
antistatic properties on the surface of a molded product. 
The antistatic properties of a carrier jig for use in the electronic field 
must not be changed by washing and temperature variations at the time of 
transportation. Then, changes in antistatic properties at the time of 
washing and annealing were measured. The results are shown in Table 9. 
TABLE 9 
__________________________________________________________________________ 
untreated washing 
voltage voltage 
half- half- 
Composition(wt %) saturation attenuation saturation attenuation 
TRB 
DBS 
HTAC6 
voltage 
time voltage 
time 
PS ABS EKV 
Na SR (KV) (sec) (KV) (sec) 
__________________________________________________________________________ 
Ex.16 50 40 10 0 0 0 0 
Ex.17 30 60 10 0 0 0 0 
Ex.18 47 7 46 0 0 0 0 
Ex.19 25 50 25 0 0 0 0 
C.Ex.23 75 5 20 0 0 0.03 4 
C.Ex.24 75 10 15 0 0 0.02 0.4 
__________________________________________________________________________ 
As means of reducing saturation voltage and voltage half-attenuation time, 
a combination of a conductive filler and a low-molecular antistatic agent 
is used (Comparative Examples 23 and 24). However, as is evident from 
Table 9, according to this method, antistatic properties are greatly 
reduced by washing. 
In contrast, a carrier jig for use in the electronic field made from the 
composition of the present invention (Examples 16 to 19) does not suffer 
from deterioration in characteristic properties by the same treatment and 
has permanent antistatic properties. The compositions of Examples 16 to 19 
do not change in characteristic properties after 5 hours of annealing at 
160.degree. C. 
The evaluation results of the compositions comprising conductive fillers 
other than CF (HTA-C6-SR) are shown in Table 10. 
TABLE 10 
__________________________________________________________________________ 
composition 
nickel 
coated saturation voltage half- 
stainless carbon voltage attenuation time 
PS ABS fiber WK200B fiber PEEA (KV) (sec) 
__________________________________________________________________________ 
Ex.20 
72 8 20 0.17 0.30 
Ex.21 70 10 20 0.12 0.32 
Ex.22 70 10 20 0.01 0.12 
C.Ex.25 70 30 0.42 &gt;600 
__________________________________________________________________________ 
The same effect is observed when nickel coated carbon fiber, stainless 
fiber and various whiskers shown in Table 10 are used (Examples 20 to 22). 
Like carbon fiber shown in Table 2, when only a conductive filler is used, 
both voltage half-attenuation time and saturation voltage cannot be 
reduced (Comparative Example 25). 
EXAMPLES 23 TO 26 AND COMATIVE EXAMPLES 26 AND 27 
Various components were mixed in a weight ratio specified in Table 11 and 
Table 12, and the resulting mixtures were evaluated in the same manner as 
in Examples 1 to 13. 
The evaluation results are shown in Table 11. 
TABLE 11 
______________________________________ 
Ex.23 C.Ex.26 
______________________________________ 
[composition(wt %)] 
PBT 85 84 
CF 8.5 6 
VGCF 1 6.5 -- 
Dentole WK300 -- 10 
surface resistivity(.OMEGA.) 2.0E + 9 5.0E + 13 
______________________________________ 
As shown in Table 11, in the composition comprising CF and VGCF1 of Example 
23, the surface resistivity can be controlled to an antistatic level by 
the effect of fusing two different types of fibers whereas in the 
composition comprising Dentole WK300 and CF of Comparative Example 26, the 
fusion effect is hardly seen. 
TABLE 12 
______________________________________ 
Ex.24 Ex.25 Ex.26 C.Ex.27 
______________________________________ 
[composition(wt %)] 
PBT 87.5 -- 77.5 70 
PC -- 87.5 -- -- 
CF 8.5 8.5 8.5 30 
VGCF 2 4 4 4 -- 
TRB-EKV -- -- 10 -- 
surface resistivity(.OMEGA.) 1.3E + 9 5.3E + 5 2.9E + 8 28 
saturation voltage(KV) &lt;0.01 &lt;0.01 0 0.05 
voltage half-attenuation &lt;0.1 &lt;0.1 0 28 
time(sec) 
flexural modulus (MPa) 7400 6800 -- -- 
______________________________________ 
As is seen from Table 12, in the compositions comprising CF and VGCF2 of 
Examples 24 and 25, the effect of fusing CF with VGCF2 is exhibited 
markedly, the saturation voltage is 1 kV or less, and the voltage 
half-attenuation time is 10 sec or less. In the composition comprising 
TRB-EKV of Example 26, the leakage of a charge is promoted more 
effectively. In contrast, when the content of CF is simply increased 
(Comparative Example 27), the voltage half-attenuation time cannot be 
reduced to 10 sec or less and a molded product of the composition is 
inferior in destaticizing properties. 
The compositions comprising CF and VGCF2 of Examples 24 and 25 have 
antistatic properties as a carrier jig for use in the electronic field and 
high rigidity required for a large carrier jig. 
Differences in antistatic properties, saturation voltage and voltage 
half-attenuation time, on molded products of Examples 24 and Comparative 
Example 27 have been studied. 
The side portion (125.times.150 mm, thickness of about 5 mm) of a molded 
silicon wafer carrier was equally divided into 9 small sections, each 
measuring about 41 mm in length.times.about 50 mm in width, as shown in 
FIG. 1 and the saturation voltage and voltage half-attenuation time of 
each section were measured to study differences in saturation voltage and 
voltage half-attenuation time. 
Table 13 shows differences in saturation voltage and voltage 
half-attenuation time. 
TABLE 13 
______________________________________ 
Ex.24 C.Ex.27 
voltage voltage 
half- half- 
saturation attenuation saturation attenuation 
divided voltage time voltage time 
portion (V) (sec) (V) (sec) 
______________________________________ 
1 0 0.0 50 26 
2 0 0.0 40 57 
3 0 0.0 50 25 
4 10 0.1 50 28 
5 0 0.0 40 54 
6 10 0.1 50 23 
7 10 0.1 50 21 
8 0 0.1 20 6 
9 10 0.1 40 19 
______________________________________ 
As is obvious from Table 13, in the composition comprising CF and VGCF2 of 
Example 24, differences in saturation voltage and voltage half-attenuation 
time are much smaller than those of the composition comprising CF and no 
antistatic polymer of Comparative Example 27. 
Thus, the composition of the present invention can reduce differences in 
antistatic properties on the surface of a molded product. 
EXAMPLES 27 AND 28 AND COMATIVE EXAMPLES 28 TO 31 
Various components were mixed in a weight ratio specified in Table 14, and 
the resulting mixtures were evaluated in the same manner as in Examples 1 
to 13. 
The results are shown in Table 14. 
TABLE 14 
__________________________________________________________________________ 
Ex.27 
Ex.28 
C.Ex.28 
C.Ex.29 
C.Ex.30 
C.Ex.31 
__________________________________________________________________________ 
Composition(wt %) 
TRB-QK 77 79 85 96 94 92 
Pelestat 6321 15 15 15 0 0 0 
HTA-C6-SR 8 6 0 4 6 8 
surface resistivity(.OMEGA.) 1E + 9 1E + 9 4E + 12 3E + 16 2E + 14 1E + 
14 
saturation voltage(KV) 0.03 0.07 1.5 1.3 0.7 0.5 
voltage half-attenuation 1.7 3 3 300&lt; 300&lt; 300&lt; 
time(sec) 
tensile strength(MPa) 73 63 44 82 95 113 
flexural strength(MPa) 90 82 65 125 145 170 
flexural modulus(MPa) 5200 4400 1900 4300 5200 6600 
__________________________________________________________________________ 
Although the composition of Comparative Example 28 has a surface 
resistivity of 10.sup.12 .OMEGA. less and a voltage half-attenuation time 
of 5 sec or less and has antistatic properties, it has a flexural modulus 
of 2,000 MPa or less and hence, not suitable for use in a large carrier 
which requires high rigidity. On the other hand, the compositions of 
Comparative Examples 29 to 31 have a flexural modulus of 4,000 to 6,000 
MPa and a voltage half-attenuation time of 300 sec or more. Therefore, it 
is possible that a large silicon wafer carrier made therefrom will have a 
problem with antistatic properties. 
The compositions comprising PEEA and carbon fiber of Examples 27 and 28 
have antistatic properties as a large silicon wafer carrier and high 
rigidity required for a large carrier. Especially, the voltage 
half-attenuation time is greatly reduced by the effect of fusing PEEA with 
carbon fiber, and the composition of Example 27 has a voltage 
half-attenuation time of the level of 1 sec. 
Differences in antistatic properties on molded products of Example 27 and 
Comparative Examples 28 and 31 have been studied based on voltage 
half-attenuation time. Table 15 shows the distribution of voltage 
half-attenuation times of 9 sections obtained by dividing the side portion 
(125.times.150 mm, thickness of about 5 mm) of a molded silicon wafer 
carrier as shown in FIG. 1. 
TABLE 15 
______________________________________ 
C.Ex.28 C.Ex.31 Ex.27 
voltage voltage voltage 
half- half- half- 
attenuation attenuation attenuation 
divided time time time 
portion (sec) (sec) (sec) 
______________________________________ 
1 0.7 300 0.0 
2 1.0 300 0.0 
3 0.8 300 0.0 
4 0.5 300 0.1 
5 1.7 300 0.0 
6 0.5 300 0.1 
7 1.4 300 0.4 
8 2.7 300 0.1 
9 4.0 300 0.4 
______________________________________ 
The composition comprising PEEA and CF (Ex.27) has a much shorter voltage 
half-attenuation time than that of the composition comprising CF and no 
antistatic polymer (C.Ex.31) and smaller differences (Ex.27) in voltage 
half-attenuation time on a flat plate than those of the composition 
comprising PEEA and no CF (C.Ex.28). Therefore, it is understood that 
antistatic properties are provided more uniformly. 
Thus, the composition comprising PEEA and CF is very useful as a raw 
material for a silicon wafer carrier.