JPH09194714A - Silicon wafer carrier having permanent antistatic property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject carrier slight in segregation of metal impurities on the surface, sufficient in antistatic properties and durability, by blending a thermoplastic resin with a specific polyether ester and molding the blend. SOLUTION: This carrier is obtained by molding a resin composition consisting of (A) 60-95 pts.wt. of a thermoplastic resin and (B) 40-5 pts.wt. of a polyether ester [a polycondensate composed of (B1) a 8-20C aromatic dicarboxylic acid/or its ester, (B2) a poly(alkylene oxide) glycol having 200-50,000 number-average molecular weight and (B3) a 4-10C glycol]. The content of the component B2 is 5-80wt.% of the component B and the component B1 consists of 98-70mol% of a para-orientated aromatic dicarboxylic acid and/or its ester and 2-30mol% of an aromatic dicarboxylic acid of the formula (Ar<1> is a 6-12C aromatic group; R<1> and R<2> are each undependently H, a 1-6C alkyl, etc.; M<+> is a metal ion, etc.) and/or its ester.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon wafer carrier used as a silicon wafer carrier, and more particularly to a silicon wafer carrier which is excellent in permanent antistatic property and has very little metal impurities oozing out to the carrier surface.

[0002]

2. Description of the Related Art Generally, plastics are characterized by high electrical insulation, but because of this they are less prone to dissipating static electricity, which causes problems such as dust sticking to products and malfunctions of instruments and IC chips. Has occurred. Above all,
The electrification of the resin molded product used for the purpose of transporting and storing the silicon wafer causes serious damage to the quality of the silicon wafer.

It is well known that an antistatic agent is added to plastic to improve its antistatic property, and there are a method of internally adding an antistatic agent and a method of coating. The coating type requires a separate coating step, and the internal addition type is more advantageous in the manufacturing process.

In the internal addition type method, a method of kneading an ionic surfactant such as a phosphonium salt, an alkyl sulfonate or an alkylbenzene sulfonate together with a plastic has been generally adopted because of its excellent effect and economical efficiency. Came. For example, a technique utilizing a phosphonium salt is disclosed in JP-A-62-230835. However, in such a method of kneading a low-molecular-weight surfactant, the surfactant oozes out onto the surface of the molded product, so the initial antistatic effect is high, but when wiped or washed, the antistatic effect is obtained. There was a problem that the film faded and decreased with time.

As a means for imparting a permanent antistatic effect,
A method of mixing an antistatic polymer with a resin is disclosed. For example, Japanese Patent Application Laid-Open No. 62-273252 discloses a technique in which a polyether ester amide is used as an antistatic polymer with respect to a resin composed of polycarbonate and a polystyrene polymer. For antistatic polymers having a sulfonate-substituted aromatic ring structure in the molecule, see US Pat. No. 4,006,123 and US Pat. No. 4,035,346.
In the publication, a polyamide having a phosphonium sulfonate salt in the molecule and having a glass transition temperature of 25 ° C. or lower is described. However, such a polymer needs to be mixed with a resin in a relatively large amount in order to enhance the antistatic effect.
There have been problems that the heat resistance and mechanical properties originally possessed by such resins are impaired, and it is difficult to handle because the glass transition temperature of such polymers is low.

When plastics are used as a silicon wafer carrier for the purpose of transporting and storing silicon wafers, when surfactants and metal impurities seep out on the surface in contact with the silicon wafers, they adhere to the surface of the silicon wafers. As a result, various devices manufactured from a silicon wafer cause crystal defects and deterioration of electrical characteristics, and cannot be used as products.
The silicon wafer carrier is used for transportation in the process of heat-treating and cleaning the silicon wafer under various conditions. Before being usually used in these processing steps, before annealing treatment to remove distortion during molding, degassing treatment to remove residual volatile components, cleaning treatment of surface deposits and subsequent drying treatment, etc. It is processed. However, the impurities contained in the silicon wafer carrier often exude to the surface by heating the silicon wafer carrier, and therefore the silicon wafer carrier does not exude impurities such as surfactants and metals immediately after molding. In addition, it is desired that these impurities do not exude even in a pretreatment process under various conditions after molding and in an environment of use as a silicon wafer carrier.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art. The object of the present invention is to remove metallic impurities on the surface of a silicon wafer carrier during processing under specific conditions. It is an object of the present invention to provide a silicon wafer carrier which has an extremely small amount of bleeding and has an antistatic property to the extent that it does not hinder the use of the silicon wafer for transportation, and the antistatic property is permanent.

Further objects and effects of the present invention will be apparent from the following description.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific polyether ester containing an aromatic dicarboxylic acid component nucleus-substituted with a sulfonic acid group and a para-oriented aromatic dicarboxylic acid component. The inventors have found that a silicon wafer carrier obtained by molding a resin composition prepared by mixing a thermoplastic resin in a specific amount exhibits excellent permanent antistatic properties, and arrived at the present invention.

The present invention comprises (A1) an aromatic dicarboxylic acid having 8 to 20 carbon atoms and / or an ester thereof, and (A2) a number average molecular weight of 200.
To 50000 poly (alkylene oxide) glycol, and (A3) 5 to 40 parts by weight of a polyether ester (A) obtained by polycondensing a glycol having 4 to 10 carbon atoms and a heat other than the above polyether ester (A). In a silicon wafer carrier molded from a resin composition comprising 95 to 60 parts by weight of a plastic resin (B), the above (A1) is a para-oriented aromatic dicarboxylic acid and / or its ester (A1a) 98 to 70 mol% And the following formula (1)

[0011]

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[In the formula (1), Ar ¹ is a trivalent aromatic group having 6 to 12 carbon atoms, R ¹ and R ² are each independently a hydrogen atom, and 1 to 6 carbon atoms.
Represents an alkyl group or an aryl group having 6 to 12 carbon atoms, M ⁺
Represents a metal ion, a tetraalkylphosphonium ion or a tetraalkylammonium ion. ] A sulfonate-substituted aromatic dicarboxylic acid and / or its ester (A1b) consisting essentially of 2 to 30 mol% and the content of (A2) is a polyether ester produced It is a silicon wafer carrier having a permanent antistatic property, which is 5 to 80% by weight of (A).

Hereinafter, the present invention will be described in detail. The polyether ester (A) used in the present invention includes (A1) an aromatic dicarboxylic acid having 8 to 20 carbon atoms and / or an ester thereof, (A2) a poly (alkylene oxide) glycol having a number average molecular weight of 200 to 50,000, and (A3) It can be obtained by polycondensing a glycol having 4 to 10 carbon atoms. Here, the aromatic dicarboxylic acid having 8 to 20 carbon atoms, which is a component constituting the polyether ester, is a para-oriented aromatic dicarboxylic acid and / or its ester (A1a) 98 to 70 mol% and the following formula (1)

[0014]

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[In the formula (1), Ar ¹ is a trivalent aromatic group having 6 to 12 carbon atoms, R ¹ and R ² are each independently a hydrogen atom, and 1 to 6 carbon atoms.
Represents an alkyl group or an aryl group having 6 to 12 carbon atoms, M ⁺
Represents a metal ion, a tetraalkylphosphonium ion or a tetraalkylammonium ion. ] A sulfonic acid group-substituted aromatic dicarboxylic acid and / or its ester (A1b) of 2 to 30 mol% is mainly contained.

The para-oriented aromatic dicarboxylic acid and / or its ester (A1a) is terephthalic acid,
Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid;
Examples thereof include aromatic dicarboxylic acid esters such as dimethyl terephthalate, diethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, and diethyl 2,6-naphthalenedicarboxylate. These may have a substituent such as an alkyl group or halogen on the aromatic ring. Even if these dicarboxylic acids and / or dicarboxylic acid esters are used alone,
You may use it in combination of 2 or more type. Of these, terephthalic acid and 2,6-terephthalic acid are used from the viewpoint of handleability when mixing the obtained polyether ester with other thermoplastic resins.
Naphthalene dicarboxylic acid, dimethyl terephthalate, 2,6-
Preference is given to using dimethyl naphthalenedicarboxylate.

The para-oriented aromatic dicarboxylic acid and / or its ester (A1a) is a polyether ester (A).
Other dicarboxylic acid and / or its ester within a range that does not significantly lower the glass transition temperature and crystallinity of (eg, 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less of the whole (A1a)). May be used. Examples of such other dicarboxylic acids and / or esters thereof include aliphatic dicarboxylic acids such as succinic acid, adipic acid and sebacic acid, aromatic dicarboxylic acids such as isophthalic acid and 2,7-naphthalenedicarboxylic acid; dimethyl succinate and amber. Diethyl acid, dimethyl adipate, diethyl adipate, dimethyl sebacate, aliphatic dicarboxylic acid esters such as diethyl sebacate, dimethyl isophthalate, diethyl isophthalate, dimethyl 2,7-naphthalenedicarboxylate,
Examples thereof include aromatic dicarboxylic acid esters such as diethyl 2,7-naphthalenedicarboxylic acid.

Polyetherester used in the present invention
By using the para-oriented aromatic dicarboxylic acid and / or its ester (A1a), (A) increases the crystallinity of (A), so that the melting point of (i) (A) increases, ) Can be sufficiently dried without fusion, and (ii) a silicon wafer carrier having a permanent antistatic property of the present invention is produced from a resin composition obtained by melt-mixing (A) with another thermoplastic resin. It is possible to obtain the silicon wafer carrier which is excellent in handleability at the time of carrying out and is therefore excellent in antistatic property.

The sulfonic acid group-substituted aromatic dicarboxylic acid used in the present invention and / or its ester (A1
b) is the following formula (1)

[0020]

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[0021]

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or 6 carbon atoms.
To 12 aryl groups, preferably an alkyl group having 1 to 3 carbon atoms such as hydrogen atom, methyl group and ethyl group.

In the above formula (1), M ⁺ represents an ion selected from the group consisting of a metal ion, a tetraalkylphosphonium ion and a tetraalkylammonium ion.
M ⁺ is an alkali metal ion such as sodium ion, potassium ion or lithium ion, an alkaline earth metal ion such as calcium ion or magnesium ion,
Zinc ion, tetramethylphosphonium ion, tetrabutylphosphonium ion, tetramethylammonium ion, tetrabutylammonium ion and the like. Among these ions, alkali metal ions and zinc ions are more preferable as metal ions. However, in the case of a divalent metal ion, 1 mol of the metal ion corresponds to 2 mol of the sulfonic acid group. As the nonmetal ion, tetrabutylphosphonium ion and tetrabutylammonium ion are preferable.

In the above formula (1), Ar ¹ is a trivalent aromatic group having 6 to 12 carbon atoms such as a benzene ring and a naphthalene ring, and these are also an alkyl group, a phenyl group, a halogen, an alkoxy group and the like. It may have a substituent.

The sulfonic acid group-substituted aromatic dicarboxylic acid (A1b) used in the present invention includes 4-sodium sulfo-isophthalic acid, 5-sodium sulfo-isophthalic acid, 4-potassium sulfo-isophthalic acid, 5 -Potassium sulfo-isophthalic acid, 2-sodium sulfo-terephthalic acid, 2-potassium sulfo-terephthalic acid, zinc 4-sulfo-isophthalate, zinc 5-sulfo-isophthalate, zinc 2-sulfo-terephthalate, 4-sulfo -Tetraalkylphosphonium salt of isophthalic acid, 5-Sulfo-tetraalkylphosphonium salt of isophthalic acid, 4-Sulfo-isophthalic acid tetraalkylammonium salt, 5-Sulfo-isophthalic acid tetraalkylammonium salt, 2-Sulfo-terephthalic acid tetraalkylammonium salt Salt, 4-sodium sulfo-2,6-
Naphthalenedicarboxylic acid, 4-sodium sulfo-2,7-naphthalenedicarboxylic acid, 4-potassium sulfo-2,6-naphthalenedicarboxylic acid, 4-sulfo-2,6-naphthalenedicarboxylic acid zinc, 4-sulfo-2,6 Examples thereof include naphthalenedicarboxylic acid tetraalkylphosphonium salt and 4-sulfo-2,7-naphthalenedicarboxylic acid tetraalkylphosphonium salt. Further, examples of the aromatic dicarboxylic acid ester (A1b) substituted with a sulfonate group include dimethyl ester and diethyl ester of the aromatic dicarboxylic acid specifically listed above.

Of these, R ¹ and R ² are both methyl groups,
It is more preferable that it is an ethyl group, Ar is a benzene ring, and M ⁺ is an alkali metal ion such as sodium or potassium in terms of polymerizability and mechanical characteristic color tone. When M ⁺ is a non-metal ion such as phosphonium or ammonium, the exudation of metal on the surface of the silicon wafer carrier is extremely small, and the obtained silicon wafer carrier exhibits excellent properties.

Specifically, for example, 4-sodium sulfo
-Dimethyl isophthalate, 5-sodium sulfo-dimethyl isophthalate, 4-potassium sulfo-isophthalic acid dimethyl, 5-potassium sulfo-dimethyl isophthalate, 2-sodium sulfo-terephthalate dimethyl, 2-potassium sulfo-dimethyl terephthalate, Tetrabutylphosphonium 5-sulfo-isophthalate and the like are more preferable.

According to the present invention, the para-oriented aromatic dicarboxylic acid and / or its ester (A1a) and the sulfonic acid group-substituted aromatic dicarboxylic acid and / or its ester (A1b) are polyether esters. It is 98 to 70 mol% and 2 to 30 mol% of the total acid components constituting (A), respectively. In other words, the sulfonic acid group-substituted aromatic dicarboxylic acid and / or its ester (A1b) is 2 to 30% of the total amount of the aromatic dicarboxylic acid and / or its ester component.
Copolymerize so as to account for mol%. Such compounds (A1
If the proportion of b) is less than 2 mol%, the antistatic effect is not sufficient, and if it exceeds 30 mol%, the polymerization reaction becomes difficult and it becomes difficult to obtain the polyether ester (A) having a sufficient degree of polymerization.
Furthermore, the crystallinity of the polyether ester (A) is lowered, resulting in insufficient drying and poor handleability. The aromatic dicarboxylic acid having 8 to 20 carbon atoms and / or its ester (A1) in the present invention is preferably a para-oriented aromatic dicarboxylic acid and / or its ester (A1).
a) 97-71 mol% and sulfonic acid group-substituted aromatic dicarboxylic acid and / or its ester (A1b) 3-29 mol%
More preferably (A1a) 95-73 mol% and (A1b)
5 to 27 mol%, particularly preferably (A1a) 91 to 75 mol% and (A1b) 9 to 25 mol%.

Poly (alkylene oxide) glycol which is one of the constituents of the polyether (A) in the present invention
As (A2), a polyalkylene glycol mainly composed of polyethylene glycol is preferable, and in that case, polypropylene glycol or the like may be contained as a copolymerization component.

The poly (alkylene oxide) glycol having a number average molecular weight of 200 to 50,000 is used. If the molecular weight is less than 200, sufficient antistatic effect cannot be obtained. Further, from the viewpoint of practicality, when the molecular weight exceeds 50,000, the reactivity decreases, so the polyether ester (A)
It is not preferable because it takes a long time during manufacturing. The preferred molecular weight of poly (alkylene oxide) glycol is 500
〜30,000, more preferably 1000〜20,000.

Further, within the above molecular weight range, such poly (alkylene oxide) glycol may have an aromatic ring in the molecule. Examples of such poly (alkylene oxide) glycols include the following formulas (2) and (3)
One having a structure of

[0032]

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In the above formulas (2) and (3), Ar ² is a benzene ring,
A divalent aromatic group having 6 to 12 carbon atoms such as a naphthalene ring,
Ar ³ and Ar ⁴ are benzene rings. These may also have a substituent such as an alkyl group, a phenyl group, a halogen or an alkoxy group. In addition, p, q, r and s represent an integer of 2 to 60, and -X- represents the number of carbon atoms such as isopropylidene group.
It is an alkylene group having 1 to 5, a cycloalkylene group having 5 to 10 carbon atoms, -O-, -S- or -SO2-. They are,
It may be used as the poly (alkylene oxide) glycol (A2) itself, which is one of the constituents of the polyether ester (A), or may be used as a part of another poly (alkylene oxide) glycol. .

Poly (alkylene oxide) glycol (A
The amount of 2) used is that of the polyether ester (A
The content of 2) is (A1), 10 to 80 wt% with respect to the polyether ester (A) obtained by polycondensing (A2) and (A3), in other words, substantially (A1), ( It should be 10 to 80% by weight based on the total amount of A2) and (A3). If it is less than 10% by weight, the antistatic effect is not sufficient, and if it is more than 80% by weight, the handleability and heat resistance may deteriorate. The preferred amount used is the resulting polyether ester.
(A) 10 to 75 wt% of the total, more preferably 12 to 70
% By weight.

Polyether ester (A) in the present invention
Examples of the glycol having 4 to 10 carbon atoms (A3) constituting the above include aliphatic glycols such as 1,4-butanediol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. it can. The glycol having 4 to 10 carbon atoms (A3) can be used alone or in combination of two or more kinds, but when two or more kinds are used, one is 70 mol% from the viewpoint of crystallinity of the polyether ester. It is preferable to use the above. Further, a small amount of ethylene glycol and / or propylene glycol may be contained within the range where the physical properties, performance, handleability, etc. of the polyether ester (A) do not change. Of the above glycols, 1,4-butanediol and 1,6-hexanediol are preferable in terms of antistatic effect, crystallinity and handleability. When the carbon number is less than 4, the glass transition temperature is increased, so that the antistatic effect is small and the handleability of the obtained polyether ester is insufficient.

The above polyether ester (A) preferably has a reduced viscosity (concentration: 1.2 g / dl) of 0.2 or more measured at 35 ° C. in a mixed solvent of phenol / tetrachloroethane (weight ratio 60/40). . If the reduced viscosity is lower than 0.2, the antistatic effect is not sufficient, which may cause deterioration of heat resistance and mechanical properties. Reduced viscosity is polyether ester (A)
Is a substantially linear polymer, and therefore, the higher one is preferable from the viewpoint of mechanical properties. The reduced viscosity is preferably 0.25 or more, more preferably 0.3 or more.

Polyether ester (A) in the present invention
Is a component (A1) ~ (A3) in the presence of a transesterification catalyst,
It can be obtained by heating and melting at 150 to 300 ° C. to cause polycondensation reaction.

The resin composition used in the present invention mainly comprises 5 to 40 parts by weight of the polyether ester (A) and 95 to 60 parts by weight of the thermoplastic resin (B) other than (A). When the amount of the polyether ester (A) is less than 5 parts by weight, the antistatic effect of the resin composition becomes insufficient. On the other hand, if it exceeds 40 parts by weight, the physical properties of the thermoplastic resin (B) itself are significantly deteriorated. A preferred ratio is 7 to 30 parts by weight of polyether ester (A),
It is 93 to 70 parts by weight of the thermoplastic resin (B).

Examples of the thermoplastic resin (B) other than the polyether ester (A) are polyester resins such as polycarbonate resin, polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyphenylene ether resin, polyethylene resin, polypropylene resin, polyvinyl chloride. Resin, polyoxymethylene resin,
Polyphenylene sulfide resin, ABS resin, AS resin, HIP
Examples thereof include polystyrene resins such as S, acrylic resins such as polymethylmethacrylate, and polyamide resins. These can be used alone or in combination of two or more. Among these, it is preferable to use a polycarbonate resin, a polyester resin, or a polystyrene resin from the viewpoint of compatibility when mixed with the polyether ester used in the present invention, since a more excellent antistatic effect is exhibited.

The method for producing the resin composition used in the present invention is not particularly limited, but the polyether ester (A) and
It can be easily produced by melt-kneading the thermoplastic resin (B) other than (A) using, for example, a kneader, Banbury mixer, twin-screw extruder or the like. Melt kneading using a twin-screw extruder is particularly preferable. The temperature for mixing depends on the thermoplastic resin used, but is generally about 180 to 320 ° C, preferably 180 to 300 ° C, and more preferably 220.
~ 280 ° C.

The resin composition used in the present invention may contain a stabilizer such as a heat stabilizer, an oxidation stabilizer, a light stabilizer and a catalyst deactivator, as long as the characteristics as a silicon wafer carrier are not affected. .

[0042]

The silicon wafer carrier of the present invention has very little metal impurities bleeding to the surface and is excellent in permanent antistatic property, and therefore can be suitably used for silicon wafer transportation.

[0043]

The preferred embodiments of the present invention will be described with reference to the following examples. In the examples, “parts” means “parts by weight”.

Unless otherwise specified, the reduced viscosity is a value measured in a mixed solvent of phenol / tetrachloroethane (weight ratio 60/40) at a concentration of 1.2 g / dl at 35 ° C.

The antistatic property was measured using an Honest meter (Static H-0110 manufactured by Shishido Electrostatic Co., Ltd.),
The half decay time at an applied voltage of 10 kV and the surface resistivity measured using a super insulation meter (SM-10E manufactured by Toa Denpa Kogyo Co., Ltd.) were evaluated. The half decay time and the surface resistivity were measured under the conditions of an ambient temperature of 23 ° C and a relative humidity of 50% after conditioning the sample for 24 hours in an atmosphere of a temperature of 23 ° C and a relative humidity of 50%.

Reference Example 1 403 parts of dimethyl 5-tetrabutylphosphonium sulfo-isophthalate, 781 parts of 2,6-naphthalenedicarboxylic acid dimethyl ester, 425 parts of 1,6-
Hexamethylene glycol, 500 parts ethylene glycol, 943 parts polyethylene glycol (number average molecular weight 200
0) and 1.5 parts of tetrabutyl titanate were charged into a reactor equipped with a rectification column and a stirrer, and the inside of the vessel was replaced with nitrogen, and then the temperature was raised to 230 ° C. under normal pressure. After carrying out the reaction for 2.5 hours while distilling off methanol at 230 ° C., the reaction product was put into a reactor having a vacuum distillation system equipped with a stirring device, and the reaction was continued for 90 minutes
The temperature was raised to 240 ° C. At that time, the pressure in the reaction system was gradually reduced to 75 mm after 0.1 mmHg, and after 4.5 hours, a highly viscous polymer was obtained. The reduced viscosity of the obtained polyetherester is 1.
It was 25.

[Reference Example 2] 237 parts of 5-sodium sulfo-
Distilled dimethyl isophthalate, 781 parts 2,6-naphthalenedicarboxylic acid dimethyl ester, 708 parts 1,6-hexamethylene glycol, 1726 parts polyethylene glycol (number average molecular weight 2000), and 1.5 parts tetrabutyl titanate. The reactor was equipped with a tower and a stirrer, the inside of the container was replaced with nitrogen, and then the temperature was raised to 220 ° C. under normal pressure. After carrying out the reaction for 5 hours while distilling off methanol at 220 ° C., the reaction product was placed in a reactor having a vacuum distillation system equipped with a stirrer,
The temperature was raised to 240 ° C in 45 minutes. At that time, the pressure in the reaction system was gradually reduced to 0.3 mmHg after 60 minutes, and a high-viscosity polymer was obtained after 6 hours. The reduced viscosity of the obtained polyether ester was 1.40 and the melting point was 157 ° C.

[Reference Example 3] 74.0 parts of dimethyl 5-sodium sulfoisophthalate, 145.5 parts of dimethyl terephthalate, 150 parts of 1,4-butanediol, 90 parts of polyethylene glycol (number average molecular weight 20000), and 0.1 Part of tetrabutyl titanate was charged into a reactor equipped with a rectification column and a stirrer, and the inside of the vessel was replaced with nitrogen, and then the temperature was raised to 200 ° C. under normal pressure. After carrying out the reaction for 3 hours while distilling off methanol at 200 ° C., the reaction product was put into a reactor having a vacuum distillation system equipped with a stirrer, while distilling off the reaction distillate under normal pressure.
The temperature was raised to 240 ° C over 120 minutes. At that time, the pressure in the reaction system was gradually reduced, and after 70 minutes, the pressure was adjusted to 1.2 mmHg to obtain a polymer.
The polyether ester obtained had a reduced viscosity of 0.25 and a melting point of 195 ° C.

[Examples 1 and 2] Polybutylene terephthalate having an inherent viscosity of 0.92 (35 ° C, o-chlorophenol solvent) of 0.92 was mixed with the polyether ester obtained in Reference Example 1 at a ratio shown in Table 1 and biaxially extruded. Using a machine, melt-kneading was performed at 260 ° C., screw rotation speed 240 rpm, and discharge rate 50 kg / h, followed by cooling and shredding to obtain a pellet-shaped resin composition used for molding. The pellets were injection-molded under the conditions of an injection pressure of 750 kg / cm ² and an injection rate of 70 cm ³ / sec to prepare a test piece, and the antistatic property was evaluated.
Table 1 shows the results.

[Comparative Example 1] In the same manner as in Example 1, test pieces were prepared with the component ratios shown in Table 1 and the above evaluation was performed.

Example 3 Using the pellets obtained in Example 1, a silicon wafer carrier was obtained by injection molding under the conditions of an injection pressure of 750 kg / cm ² and an injection rate of 68 cm ³ / sec. When a portion in contact with the silicon wafer was cut out from this silicon wafer carrier and the antistatic property was evaluated, the half decay time was 5 seconds, and the silicon wafer carrier had an excellent antistatic property. Furthermore, the half-decay time after aging at 160 ° C for 100 hours was 9 seconds, which was excellent antistatic property. In addition, when the amount of alkali metal eluted from this silicon wafer carrier was quantified, it was 1 ppm.
And it was an extremely low level.

Example 4 Polybutylene terephthalate having an intrinsic viscosity of 0.92 (35 ° C., o-chlorophenol solvent) was blended with the polyether ester obtained in Reference Example 2 in the proportion shown in Table 2, and the mixture was mixed in a twin-screw extruder. Using 260 ℃, screw speed 24
After melt-kneading at 0 rpm and a discharge rate of 50 kg / h, the resin composition was pelletized by cooling and shredding. The pellets were injection-molded under the conditions of an injection pressure of 750 kg / cm ² and an injection rate of 70 cm ³ / sec to prepare a test piece, and the antistatic property was evaluated. Table 2 shows the results.

[Examples 5 and 6] Polycarbonate resin and ABS resin were each blended with the polyether ester obtained in Reference Example 3 in the proportions shown in Table 3, and were mixed using a twin-screw extruder.
After melting and kneading at a temperature of 240 ° C., a screw rotation speed of 240 rpm, and a discharge rate of 50 kg / h, the mixture was cooled and shredded to obtain a pellet-shaped resin composition used for molding. This pellet has an injection pressure of 750 kg / cm ² and an injection rate of 7
A test piece was prepared by injection molding under the condition of 0 cm ³ / sec, and the antistatic property was evaluated. Table 3 shows the results.

Example 7 Using the pellets obtained in Example 4, a silicon wafer carrier was obtained by injection molding under the conditions of an injection pressure of 750 kg / cm ² and an injection rate of 68 cm ³ / sec. When a portion in contact with the silicon wafer was cut out from this silicon wafer carrier and the antistatic property was evaluated, the half-decay time was 3 seconds, which was an excellent antistatic property as a silicon wafer carrier. Furthermore, the half-decay time after aging at 160 ° C for 100 hours maintained an excellent antistatic property of 8 seconds. Also, when the amount of alkali metal eluted from this silicon wafer carrier was quantified, it was 16 pp
m was a sufficiently low level for practical use.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C08L 67/00 LPF C08L 67/00 LPF 69/00 LPQ 69/00 LPQ 101/00 LSY 101/00 LSY H01L 21/68 H01L 21/68 T

Claims (3)

[Claims] 1. (A1) an aromatic dicarboxylic acid having 8 to 20 carbon atoms and / or an ester thereof, and (A2) a number average molecular weight of 200 to 50,000.
Poly (alkylene oxide) glycol, and (A3) 5-40 parts by weight of a polyether ester (A) obtained by polycondensing a glycol having 4 to 10 carbon atoms and a thermoplastic resin other than the above polyether ester (A) (B) A silicon wafer carrier molded from a resin composition consisting of 95 to 60 parts by weight, wherein (A1) is a para-oriented aromatic dicarboxylic acid and / or its ester (A1a) 98 to 70 mol% and Formula (1) [In the formula (1), Ar ¹ is a trivalent aromatic group having 6 to 12 carbon atoms, R ¹ and
R ² independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and M ⁺ represents a metal ion, a tetraalkylphosphonium ion or a tetraalkylammonium ion. ] And the aromatic dicarboxylic acid substituted with a sulfonate group and / or its ester (A1b) 2 to 30 mol%, and (A
The content of 2) is 5 to 5 of the produced polyether ester (A).
A silicon wafer carrier having a permanent antistatic property, which is 80% by weight. 2. The thermoplastic resin (B) other than the polyether ester (A) is selected from the group consisting of a polycarbonate resin, a polyester resin and a polystyrene resin.
2. The silicon wafer carrier having permanent antistatic property according to claim 1, which is a thermoplastic resin composed of two or more kinds. 3. The silicon wafer carrier having permanent antistatic property according to claim 2, wherein the thermoplastic polyester resin is polybutylene terephthalate.