JP2005150449A - Conveying component formed of thermoplastic polyester resin composition having excellent permanent antistatic property - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide conveying components formed of a resin composition with excellent permanent antistatic properties, when being used as the conveying components, no contamination problems in products to be conveyed due to a volatile gas or eluted metal occur, and the products to be conveyed are not damaged by its flexibility. <P>SOLUTION: (A) With respect to 100 parts by weight of a thermoplastic polyester resin, (B) 35 to 150 parts by weight of a specific polyeterester block copolymer are arranged to obtain a resin composition as the conveying components. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a conveying part molded from a thermoplastic polyester resin composition having excellent permanent antistatic properties obtained by blending a specific amount of a polyetherester-based antistatic polymer with a thermoplastic polyester resin.

  The thermoplastic resin is remarkably easily charged by abrasion, peeling, and the like, and brings various problems to the molded product, for example, impact due to discharge during use and adhesion of dust.

  As a method for imparting antistatic properties to a thermoplastic resin, a method using a low molecular weight antistatic agent such as a phosphonium salt of alkyl sulfonic acid (Patent Document 1) and a high molecular weight antistatic agent such as polyetheresteramide are used. How to do is known. Although the low-molecular-type antistatic agent has a high initial effect, its performance changes depending on environmental changes, such as loss of antistatic properties when wiped or washed. Further, when the polymer type antistatic agent is applied to engineering plastics, there are many problems in terms of heat resistance and melt stability.

Although it is already known to use a polyether ester type polymer antistatic agent as a method for imparting permanent antistatic properties (Patent Document 2), it is sufficient when added to a crystalline engineering plastic or the like. It is difficult to impart antistatic properties. In addition, for example, when a low molecular weight antistatic agent known as a transportation component in the electronics field is added to engineering plastics, the antistatic property may change during the water washing process, or the silicon wafer may be contaminated by eluted metals or volatile gases. Occurs. Moreover, the conveyance parts in the electronics field are required to have flexibility (for example, about 1000 to 1500 MPa in bending elastic modulus) for the purpose of protecting the silicon wafer.
JP-A-62-230835 JP-A-6-57153

  An object of the present invention is to solve these problems.

  In other words, the present invention has excellent permanent antistatic properties, and when used in a transportation component, the problem of contamination of the transported product due to volatile gas or eluted metal does not occur, and the transported product is damaged by its flexibility. It is an object of the present invention to provide a conveying part molded from a resin composition without any problem.

  As a result of intensive studies, the present inventor has found that when a suitable amount of a specific polyetherester block copolymer excellent in compatibility, mechanical strength, heat resistance, etc. is mixed with a thermoplastic polyester resin, excellent permanent antistatic properties and flexibility are obtained. It has been found that there are very few eluted metals and volatile gases that are sources of contamination, and the present invention has been achieved.

That is, the present invention
(A) An acid component comprising 60 to 100 mol% of a terephthalic acid component and 40 to 0 mol% of an isophthalic acid component, based on 100 parts by weight of the thermoplastic polyester resin, based on (B) (a) the total acid component,
(B) a poly (alkylene oxide) glycol component represented by the following general formula (I):

[Wherein X represents a substituent —H, —CH ₃ , —CH ₂ Cl, —CH ₂ Br, —CH ₂ I or —CH ₂ OCH ₃ , and n and m are n ≧ 0, m ≧ 0. And 120 ≧ (n + m) ≧ 20. When m is 2 or more, X may be the same or different. The poly (alkylene oxide) glycol component may be a random copolymer or a block copolymer. ]
(C) A polyether ester block copolymer comprising a glycol component consisting of 65 to 100 mol% tetramethylene glycol and 35 to 0 mol% ethylene glycol based on the total glycol component (excluding the component (b)), And the resin obtained by mix | blending 35-150 weight part of polyether ester block copolymers whose copolymerization amount of (b) component is 40 to 80 weight% of all the glycol components (however, (b) component is included) It is a conveying part molded from the composition.

  For example, silicon wafer carrier, silicon wafer carrier box, silicon wafer presser bar, IC tray, liquid crystal substrate carrier, HDD and LCD related parts carrier jig, glass tray, top robot flange , Side grip pits, forklift slots, conveyor rails, cassette sensing pads and holes, wafer sensing paths, infopads, wafer pop-out prevention protrusions, bottom forklift slot inclinations, and the like.

  Hereinafter, the present invention will be described in detail.

[Thermoplastic polyester resin]
As the thermoplastic polyester resin (A) used in the present invention, terephthalic acid or 2,6-naphthalenedicarboxylic acid is used as the main acid component, and ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, etc. An aromatic thermoplastic polyester comprising the aliphatic diol as a main diol component can be exemplified.

  The main acid component refers to 70 mol%, preferably 80 mol%, more preferably 90 mol% or more of the acid component relative to the total acid component, and the main diol component refers to 70 mol%, preferably 80 mol, relative to the total diol component. %, More preferably 90 mol% or more diol component.

  Of these, polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polybutylene-2,6-naphthalate and polyethylene-2,6-naphthalate having a high crystallization rate are preferable, and polybutylene terephthalate is particularly preferable.

  The aromatic thermoplastic polyester may be one obtained by substituting a part of the above-mentioned polyester with a copolymer component. Examples of the copolymer 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; diphenyls such as 4,4′-diphenyldicarboxylic acid and 3,4′-diphenyldicarboxylic acid; Aliphatic dicarboxylic acids such as dicarboxylic acids, diphenoxyethanedicarboxylic acids such as 4,4′-diphenoxyethanedicarboxylic acid, aliphatics such as succinic acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, and cyclohexanedicarboxylic acid Or alicyclic dicarboxylic acid; 1 Alicyclic diols such as 4-cyclohexanedimethanol; dihydroxybenzenes such as hydroquinone and resorcin; bisphenols such as 2,2′-bis (4-hydroxyphenyl) -propane and bis (4-hydroxyphenyl) -sulfone; Examples include aromatic diols such as ether diols obtained from bisphenols and glycols such as ethylene glycol; oxycarboxylic acids such as ε-oxycaproic acid, hydroxybenzoic acid, and hydroxyethoxybenzoic acid. Furthermore, as the branched component in the above-mentioned aromatic polyester, an acid having a polyfunctional ester-forming ability such as trimesic acid or trimellitic acid or an alcohol having a polyfunctional ester-forming ability such as glycerin, trimethylolpropane, pentaerythritol, etc. 0.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less may be copolymerized.

  The intrinsic viscosity of the thermoplastic polyester resin used in the present invention is preferably 0.6 to 1.2. If the intrinsic viscosity is less than 0.6, sufficient characteristics cannot be obtained, and if it is greater than 1.2, the melt viscosity is high, the fluidity is lowered, and the moldability is impaired. Here, the intrinsic viscosity is a value measured in orthochlorophenol at 35 ° C.

[Polyether ester block copolymer]
The polyether ester block copolymer (B) used in the present invention is:
(B) an acid component comprising 60 to 100 mol% of a terephthalic acid component and 40 to 0 mol% of an isophthalic acid component based on the total acid component, and (b) a poly (alkylene oxide) glycol component represented by the following general formula (I) ,

[Wherein X represents a substituent —H, —CH ₃ , —CH ₂ Cl, —CH ₂ Br, —CH ₂ I or —CH ₂ OCH ₃ , and n and m are n ≧ 0, m ≧ 0. And 120 ≧ (n + m) ≧ 20. When m is 2 or more, X may be the same or different. The poly (alkylene oxide) glycol component may be a random copolymer or a block copolymer. ]
(C) A polyether ester block copolymer comprising a glycol component consisting of 65 to 100 mol% tetramethylene glycol and 35 to 0 mol% ethylene glycol based on the total glycol component (excluding the component (b)), And (b) a polyether ester block copolymer in which the copolymerization amount is 40 to 80% by weight of the total glycol component (including the (b) component).

  The tetramethylene glycol component in the polyetherester block copolymer (B) needs to be 65 mol% or more based on the total glycol components (excluding the component (b)). If the tetramethylene glycol component is less than 65 mol%, the moldability is deteriorated.

  The polyether ester block copolymer (B) includes dicarboxylic acids other than terephthalic acid and isophthalic acid as the acid component (I), such as phthalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, trimellitic acid, Pyromellitic acid, naphthalenedicarboxylic acid, and cyclohexanedicarboxylic acid may be copolymerized.

  When these components are copolymerized, the copolymerization amount is preferably less than 40 mol%, more preferably less than 20 mol%, based on the total acid component amount.

  Polyether ester block copolymer (A) has a glycol component (c) as a diol other than tetramethylene glycol and ethylene glycol, such as trimethylene glycol, 1,5-pentanediol, 1,6-hexanediol, and diethylene glycol. 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol may be copolymerized.

  When these components are copolymerized, the copolymerization amount is preferably less than 40 mol%, more preferably less than 20 mol%, based on the total glycol component amount (excluding the component (b)).

  Polyether ester block copolymer (B) is copolymerized with poly (alkylene oxide) glycol component (b), and the copolymerization amount of this (b) component is the total glycol component (however, (b) component 40 to 80% by weight, preferably 40 to 70% by weight. If it is less than 40% by weight, the effect of antistatic properties is small, and if it exceeds 80% by weight, polymer fusion and sticking occur, resulting in problems in the process.

In the formula (I), X represents a hydrogen atom (—H) or a substituent —CH ₃ , —CH ₂ Cl, —CH ₂ Br, —CH ₂ I or —CH ₂ OCH ₃ .

  When X is a complex group other than these, it is difficult to increase the degree of polymerization of the copolymer due to steric hindrance. A polymer in which the main chain of the polyethylene glycol unit is directly substituted with a halogen or an alkoxy group has a strong polymer degradability. X is preferably a hydrogen atom.

  In the formula (I), n and m are required to satisfy n ≧ 0, m ≧ 0, and 120 ≧ (n + m) ≧ 20. When the value of (n + m) is less than 20, the block property of the block copolymer is lowered and the antistatic property is insufficient. On the other hand, when the value of (n + m) exceeds 120, the degree of polymerization is lowered and sufficient. Not only is it difficult to obtain a copolymer having a degree of polymerization, but the antistatic property is lowered. When m is 2 or more, the above Xs may be the same or different. The poly (alkylene oxide) glycol component (b) may itself be a random copolymer or a block copolymer.

  The compounding quantity of the polyetherester block copolymer (B) used for this invention is 35-150 weight part with respect to 100 weight part of thermoplastic polyester resins (A), Preferably it is 35-100 weight part. . If it is less than 35 parts by weight, sufficient antistatic properties cannot be imparted. When the amount is more than 150 parts by weight, the effect of improving the antistatic property is in a saturated state, and there is a problem in terms of lowering the mechanical properties.

[Additive]
Various additives can be added to the resin composition of the present invention as long as the object of the present invention is not impaired.

  Examples of additives include mold release agents such as montanic acid wax, polyethylene wax and silicone oil, flame retardants, flame retardant aids, heat stabilizers, ultraviolet absorbers, pigments, dyes, KCl, NaCl and other metal salts. Can be mentioned.

  In addition, other thermoplastic resins such as polyethylene, polypropylene, polystyrene, acrylic resins, fluororesins, polyamides, polyacetals, polysulfones, polyphenylene sulfides; thermosetting resins such as phenol resins and melamine resins are used within the range not impairing the object of the present invention. , Silicone resin, epoxy resin; soft thermoplastic resin such as ethylene / vinyl acetate copolymer, polyester elastomer, epoxy-modified polyolefin, and other fillers such as talc, kaolin, wollastonite, Clay, silica, sericite, titanium oxide, carbon black, graphite, metal powder, glass beads, glass balloons, glass flakes, glass powder, and glass fibers can be added.

[Method for Producing Resin Composition]
The resin composition of the present invention can be obtained by blending the above components (A) and (B) by an arbitrary blending method.

  Usually, it is preferable to disperse these blending components more uniformly, and it is preferable to disperse all or part of them simultaneously or uniformly.

  In the resin composition of the present invention, it is possible to use a method in which all or a part of the components are simultaneously or separately mixed and homogenized with a mixer such as a blender, kneader, Banbury mixer, roll, or extruder.

  Further, it is also possible to use a method in which a pre-dry blended composition is melt-kneaded with a heated extruder, homogenized, extruded into a wire shape, and then cut into a desired length and granulated.

[Manufacturing method of conveying parts]
Taking a polyester resin as an example, when a Mitsubishi 80MSP injection molding machine is used, it is desirable to mold at a cylinder of 250 ° C., a mold temperature of 60 ° C., and an injection speed / injection pressure of 40 to 60%. The conveyance parts thus obtained have excellent permanent antistatic properties.

  The resin composition of the present invention is particularly preferably used as a glass tray, a silicon wafer carrier, and infopad (a jig attached to the bottom surface of the silicon wafer carrier).

  The following examples illustrate the invention.

The raw materials and evaluation methods used in the examples are as follows. The unit of Table 3 with respect to the blending amount is% by weight.
1. material:
The following materials were used.
-Polyetherester block copolymers 1-4
React dimethyl terephthalate, dimethyl isophthalate, tetramethylene glycol, ethylene glycol, and (modified) polyethylene glycol, and tetrabutyl titanate (0.090 mol% with respect to the acid component) as a catalyst so as to have the composition described in Table 1. An esterification reaction was carried out at an internal temperature of 190 ° C. After about 80% of the theoretical amount of methanol was distilled, the temperature was raised and a polycondensation reaction was performed while gradually reducing the pressure. After reaching a vacuum of 1 mmHg or less, the reaction was continued at 240 ° C. for 200 minutes. Next, the antioxidant Irganox 1010 was added in an amount of 5% by weight based on polyethylene glycol or modified polyethylene glycol, to complete the reaction. The composition of the purified polymer is shown in Table 2. The copolymer used in Synthesis Example 1 was used in the examples. Hereinafter, the copolymer obtained in Synthesis Example 1 is referred to as “antistatic agent (1)” in the table.

・ Polybutylene terephthalate (PBT (1))
TRE-DM2 (IV: 0.90) manufactured by Wintech Polymer Co., Ltd.
・ Polybutylene terephthalate (PBT (2))
TRE-DE2 (IV: 1.10) manufactured by Wintech Polymer Co., Ltd.
・ Polyether ester type antistatic agent (Antistatic agent (2))
EXA726 manufactured by Dainippon Ink Co., Ltd.
・ Polyetheresteramide type antistatic agent (Antistatic agent (3))
Pelestat 6321 manufactured by Sanyo Chemical Co., Ltd.
2. Antistatic property (surface resistivity)
The antistatic property was evaluated by the surface resistivity (measurement voltage: 500 V) measured using a super insulation meter (R8340 ULTRHIGH RESISTANCE METER manufactured by Advantest).

The surface resistivity was measured at an ambient temperature of 23 ° C. and a relative humidity of 50% after the sample was conditioned for 24 hours in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%.
3. Measurement of physical properties The bending test was measured according to ISO178.
4). Volatile gas measurement Measured by headspace gas chromatography. The measured value is shown as a total gas amount in terms of THF.
HS: PERKIN ELMER HeadspaceSampler HS40XL
GS: HP6890 HEWLET PACKARD
HS heating condition: sample weight: 3 g, 150 ° C. × 1 hr
5). Eluted metal The metal deposited in warm pure water was measured with an atomic absorption photometer. A measured value is shown by the total metal amount of Na, K, Fe, Al, and Ti.
Z-8100 atomic absorption spectrophotometer pretreatment manufactured by Hitachi, Ltd .: Sample / pure water = 3 g / 30 cc, 80 ° C. × 2 hours [Examples 1-3 and Comparative Examples 1-3]
Various raw materials were previously dry blended uniformly in the amounts shown in Table 3, and then a cylinder temperature of 210 to 260 ° C., a screw rotation speed of 160 to 220 rpm, and a discharge amount of 50 kg / kg using a vented twin screw extruder with a screw diameter of 44 mm. After melt-kneading at h, the thread discharged from the die was cooled and then cut to obtain a molding pellet.

The pellets were then used for injection molding and disc test pieces (diameter 100 mm, thickness 3 mm by injection molding under the conditions of an injection pressure of 750 kg / cm ² , an injection speed of 70 cm ³ / sec, a cooling time of 15 seconds, and a total molding cycle of 25 seconds. )created. Further, the side portion of the infopad was cut into a required size, and the above evaluation was performed. These evaluation results are shown in Table 3.

  As shown in Table 3, the polyether ester type antistatic agent prepared in Synthesis Example 1 (1) used products (Examples 1 to 3) are other polyether ester type antistatic agents (2) (Comparative Example 2) and Compared to polyether ester amide type antistatic agent (3) (Comparative Example 3) which is generally used in many cases, it is excellent in low gas property and low elution metal property. Furthermore, it has both the flexibility necessary for preventing destruction of the conveyed product and good antistatic properties.

Claims (3)

(A) An acid component comprising 60 to 100 mol% of a terephthalic acid component and 40 to 0 mol% of an isophthalic acid component, based on 100 parts by weight of the thermoplastic polyester resin, based on (B) (a) the total acid component,
(B) a poly (alkylene oxide) glycol component represented by the following general formula (I):

[Wherein X represents a substituent —H, —CH ₃ , —CH ₂ Cl, —CH ₂ Br, —CH ₂ I or —CH ₂ OCH ₃ , and n and m are n ≧ 0, m ≧ 0. And 120 ≧ (n + m) ≧ 20. When m is 2 or more, X may be the same or different. The poly (alkylene oxide) glycol component may be a random copolymer or a block copolymer. ]
(C) A polyether ester block copolymer comprising a glycol component consisting of 65 to 100 mol% tetramethylene glycol and 35 to 0 mol% ethylene glycol based on the total glycol component (excluding the component (b)), And the resin obtained by mix | blending 35-150 weight part of polyether ester block copolymers whose copolymerization amount of (b) component is 40 to 80 weight% of all the glycol components (however, (b) component is included) Conveyor parts molded from the composition.   The thermoplastic polyester resin (A) is at least one polyester selected from the group consisting of polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polybutylene-2,6-naphthalate and polyethylene-2,6-naphthalate. The transportation parts described.   The conveyance part molded from the resin composition according to claim 1 or 2, wherein the flexural modulus is 1000 to 1500 MPa.