TWI527841B - And an aromatic polycarbonate resin composition for storing and transporting the container - Google Patents

Description

Aromatic polycarbonate resin composition for thin plate storage and transport container

The present invention relates to an aromatic polycarbonate resin composition for a thin plate storage and transport container, which is used for storage or transportation of a wafer processed into a magnetic disk or an integrated circuit wafer. More specifically, the resin composition for a thin plate storage and transport container is excellent in mold releasability during molding, and is contaminated on the surface of a semiconductor wafer or a disk to suppress metal atoms and volatility. The gas occurs to the extent that it does not cause obstacles.

It is generally important to accommodate a container that transports a sheet that is sensitive to surface contamination such as wafers or disks, and it is important to keep the surface of the wafer clean and transport.

Therefore, synthetic resins, for example, general-purpose resins derived from polypropylene, polyethylene, acrylonitrile, butadiene, styrene, polyacetal, etc., are polyamine, polybutylene terephthalate, polycarbonate. Formed by high-performance or ultra-high-performance resin materials such as polyfluorene, fluorine-based resin, liquid crystal polymer, polyphenylene sulfide, polyether oxime, and polyether ketone. Among them, uniform mechanical properties, formability, and light weight using a specific gravity of about 0.9, coupled with mass production in a synthetic resin, favorable economical price, etc., based on various viewpoints, Since the cost performance of the total is good, a polypropylene resin is used in the prior art (Patent Document 1).

However, when polypropylene is used as a basic material and various additives are added to form a wafer storage transfer container, organic substances or ionic impurities are leaked from the container, and the semiconductor wafer is contaminated. Further, since the surface hardness of the polypropylene is relatively low, when the semiconductor wafer is taken out from the container and the like, and the surfaces are in contact with each other and rubbed, fine particles are generated, which may cause contamination of the semiconductor wafer.

Further, a tantalum wafer container is disclosed which is composed of a polyester resin which defines the amount of volatile gas in a specific heat treatment and the amount of alkali metal dissolved in water (Patent Document 2). Although these polyester resins can prevent a certain degree of contamination of the germanium wafer, they are still insufficient, and even the strength of the supply container cannot be said to be sufficient.

The requirement for contamination from the container to the wafer surface has become more stringent with the recent large diameter of semiconductor wafers, and higher strength materials have been sought. Next, not only the wafer but also the disk storage and transport container have the same requirements. In recent years, a resin composition containing a polycarbonate resin or a polycarbonate resin as a main component has been used as a molding material suitable for such requirements.

It is preferable that the material for the sheet storage container is such that the impurity component which is likely to be volatilized or leaked is not present in the material. However, in reality, it is not technically feasible to remove all impurity components having the possibility of volatilization or leakage from the material. It is important to suppress the type or amount of impurities and combinations thereof that affect the thin plates such as wafers to the extent that they are not substantially damaged. Further, it should be noted, for example, what is the component to be noted in the measurement of the volatile component at the time of heating, and then to what extent the amount of volatilization as the target material is reduced.

However, there is no clear information about the relationship between "the type of organic or inorganic impurities leaking from polycarbonate resin or a molded article of polycarbonate as a material" and the "degree of contamination of the wafer surface". Making the best choice is now in an extremely difficult state.

Therefore, Patent Document 3 and Patent Document 4 disclose a thin plate storage transfer container which is formed of a polycarbonate resin having a specific impurity amount reduced.

Patent Document 5 discloses a chlorine ion which is present in a crucible wafer or the like which is incorporated into a storage material of a thin plate storage transport container, or a malfunction due to a malfunction of a processed object, and self-polycarbonate The chloride resin which is continuously volatilized in the storage container made of the ester resin. Further, by using a resin composition containing a polycarbonate resin and an epoxy compound as a substrate of the precision member storage container, the chloride ions can be captured.

However, these inventions prevent the contamination of the objects to be stored, and although the effects can be confirmed, the improvement in productivity at the time of molding is still inconclusive.

Recently, with the increase in the diameter of semiconductor wafers, the size of the thin plate storage and transport container has also increased. However, from the viewpoints of storage places, logistics costs, and reduction of raw material costs, it is preferable to avoid exceeding the necessary enlargement and to draw the draft angle of the container. The draft angle is designed to be as small as possible. The larger the molded article is, and the smaller the draft angle is, the larger the mold release load at the time of demolding of the molded article. For this reason, in recent years, there has been a tendency to seek high mold release properties depending on materials.

Further, the epoxy compound added to the polycarbonate resin composition disclosed in Patent Document 5 is basically regarded as being applicable to all of the materials having an epoxy functional group. Among the epoxy compounds, such as epoxidized soybean oil or epoxidized linseed oil, which is well known as a plasticizer, it is also expected to have a productivity improvement by adding it. However, since the polycarbonate resin molded article which is in contact with the epoxy compound is reduced in the boundary stress, it is added to a large and complicated shape as in the thin plate storage and transport container, and the raw material of the molded article having a relatively large residual stress is induced. The possibility of cracking is extremely high, but it is likely to be related to reduced productivity.

Japanese Laid-Open Patent Publication No. 2010-275465 (Patent Document 3) Japanese Patent Publication No. 3995346 (Patent Document 4) Japanese Laid-Open Patent Publication No. 2010-275465 (Patent Document 5) Japanese Patent No. 3282584

An object of the present invention is to provide a resin composition for a thin plate storage and transport container which can reduce the surface contamination of a thin plate such as a semiconductor wafer or a magnetic disk which is sensitive to surface contamination, and which is excellent in mold release property at the time of molding.

The present inventors have found that in the aromatic polycarbonate resin composition, the content of the specific component is specified, and the above-mentioned object can be attained by further formulating a releasing agent having a specific chemical structure within a specific range, and the present invention is completed. .

In other words, the present invention provides: 1. A resin composition for a thin plate storage and transport container, the resin composition comprising: [I] 100 parts by weight of an aromatic polycarbonate resin; [II] 0.01 to 0.5 parts by weight (B parts by weight) of the ester compound, which is composed of a polyol and a higher fatty acid, and has an average degree of esterification (A%) of 30 to 99% of the total ester, wherein the resin composition The product is characterized by satisfying the following conditions: (i) a chlorine atom content of 5 ppm or less, (ii) a carbon tetrachloride content of 3 ppm or less, and (iii) a total amount of a phenol compound having a carbon number of 6 to 18 of 40 ppm or less, (iv) The total content of sodium and iron atoms is 0.1 ppm or less, and (v) 0.1 (100-A) × B ≦ 10.0 (1) of the following formula (1).

According to the present invention, there is provided a method for improving mold releasability in forming a sheet storage container, which comprises the steps of: (i) preparing a molding material; and (ii) forming a molding material in a mold. A thin plate storage transfer container is obtained, wherein the molding material contains the following resin composition: [I] 100 parts by weight of an aromatic polycarbonate resin; and [II] 0.01 to 0.5 parts by weight (B parts by weight) of an ester compound, It is composed of a polyol and a higher fatty acid, and has an average degree of esterification (A%) of 30 to 99% of the total ester, wherein the resin composition is characterized by using a resin composition satisfying the following conditions: (i) a chlorine atom a phenol compound having a content of 5 ppm or less, (ii) a carbon tetrachloride content of 3 ppm or less, (iii) a carbon number of 6 to 18, a total content of 40 ppm or less, and (iv) a total content of sodium and iron atoms of 0.1 ppm or less. And (v) 0.1 (100-A) × B ≦ 10.0 (1) of the following formula (1).

(aromatic polycarbonate resin)

The aromatic polycarbonate resin used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor by a solution method or a melting method. Representative examples of the dihydric phenol used herein may be exemplified by 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), bis(4-hydroxyphenyl)methane, 1, 1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane , 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)ether 4,4-dihydroxydiphenyl, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl)anthracene, and the like. Preferred dihydric phenols are bis(4-hydroxyphenyl)alkanes, of which bisphenol A is particularly preferred.

In the case of a carbonate precursor, a carbonyl halide, a carbonate ester or a haloformate may be used, and specifically, it may be a phosgene, a diphenyl carbonate or a dihalohalide of a dihydric phenol. Wait.

When an aromatic polycarbonate resin is produced by reacting the above dihydric phenol with a carbonate precursor by a solution method or a melting method, the dihydric phenol may be used singly or in combination of two or more kinds, and may be used as needed. Medium, blocking agent, antioxidant of dihydric phenol, etc. Further, the aromatic polycarbonate resin may be a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound, an aromatic or an aliphatic group, and preferably an aromatic group having a carbon number of 8 or more. The polyester carbonate resin in which the aliphatic difunctional carboxylic acid is copolymerized may further be a mixture of two or more kinds of aromatic polycarbonate resins.

In the present invention, it is particularly suitable to use a solution method in which the reaction caused by the solution method is usually a reaction of a dihydric phenol with phosgene and is carried out in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine can be used. As the organic solvent, for example, a halogenated hydrocarbon such as dichloromethane or chlorobenzene can be used. Further, in order to promote the reaction, for example, a catalyst such as a tertiary amine or a quaternary ammonium salt may be used. At this time, the reaction temperature is usually from 0 to 40 ° C, and the reaction time is from several minutes to about 5 hours.

Further, as the polymerization reaction, a monofunctional phenol can be used as the terminal blocking agent. Monofunctional phenols are used as blocking agents, which are generally used for the adjustment of molecular weight, and the obtained polycarbonate resin is sealed according to the group mainly composed of terminal monofunctional phenols. Type of material, excellent thermal stability. Monofunctional phenol In general, it is a phenol or a lower alkyl-substituted phenol, which can be represented by a monofunctional phenol represented by the following formula (1).

(wherein R represents a hydrogen atom or an alkyl group having a carbon number of 1 to 9, preferably 1 to 8; m represents 0 to 5, preferably an integer of 0 to 3).

Specific examples of the monofunctional phenols include phenol, p-tert-butylphenol, p-cumyl phenol, and isooctyl phenol.

The reaction caused by the melting method is usually a transesterification reaction of a dihydric phenol with diphenyl carbonate, and the dihydric phenol is mixed with diphenyl carbonate in the presence of an inert gas, preferably for accelerating the polymerization rate, and using a base. The polymerization catalyst of a (metal) metal compound or the like is usually reacted at 120 to 350 ° C under reduced pressure. The degree of pressure reduction is changed stepwise, and finally, it is set to 1 mmHg or less, and the generated phenols are removed from the system. The reaction time is usually about 1 to 4 hours.

The molecular weight of the aromatic polycarbonate resin, preferably the viscosity average molecular weight (M), is in the range of from 1.4 × 10 ⁴ to 3.0 × 10 ⁴ , more preferably in the range of from 1.6 × 10 ⁴ to 2.5 × 10 ⁴ , still more preferably The range of 1.7 × 10 ⁴ to 2.4 × 10 ⁴ is particularly preferably in the range of 1.8 × 10 ⁴ to 2.3 × 10 ⁴ . The aromatic polycarbonate resin having such a viscosity average molecular weight has a certain mechanical strength, and the fluidity at the time of molding is also preferably good. When the molecular weight is less than 1.4 × 10 ⁴ , the molded article has no apparent strength, so that it is difficult to obtain a practical material, and when the molecular weight exceeds 3.0 × 10 ⁴ , the problem of deterioration in molding fluidity is liable to occur. Further, in this case, a phenol compound or a chlorine-based organic solvent which causes contamination of a thin plate such as a tantalum wafer may be generated, which is difficult to volatilize from the resin during the extrusion processing, and the problem may be eliminated, and when the extrusion temperature is raised, The chlorine-based organic solvent is reduced, but the decomposition of the resin proceeds, resulting in an increase in the amount of the phenol compound.

The viscosity average molecular weight (M) of the present invention is obtained by dissolving a specific viscosity (η _SP ) obtained by dissolving a solution of 0.7 g of an aromatic polycarbonate resin in 100 ml of dichloromethane at 20 ° C, and inserting a secondary formula.

η _SP /c=[η]+0.45×[η] ² c (but [η] is the ultimate viscosity) [η]=1.23×10 ^-4 M ^0.83 c=0.7

(ester compounds)

The resin composition of the present invention contains 0.01 to 0.5 part by weight (B parts by weight) based on 100 parts by weight of the aromatic polycarbonate resin, and is composed of a polyol and a higher fatty acid, and has an average degree of esterification of 30% of the total ester. Up to 99% (A%) of the ester compound, and satisfying 0.1 ≦ (100-A) × B ≦ 10.0.

When the average degree of esterification of the ester compound is too low, the polycarbonate resin is decomposed by lowering the heat resistance during molding, so that the amount of the phenol compound is increased, or the molecular weight of the resin is lowered or the color tone is poor. On the other hand, when the average degree of esterification of the ester compound is too high, the chloride ion trapping effect due to decomposition of the chlorine-based compound cannot be exhibited, and contamination of the thin plate cannot be suppressed.

Further, the content of the ester compound is preferably from 0.015 to 0.3 parts by weight, more preferably from 0.02 to 0.1 part by weight, per 100 parts by weight of the aromatic polycarbonate resin. When the amount of the ester compound is too small, the effect as a release agent is insufficient. When the amount is too large, the heat resistance at the time of molding, the transparency and mechanical strength of the molded article are lowered, and it is likely to be related to the ester compound itself or its decomposition. It is related to the pollution of thin plates caused by the sublimation of things.

Further, it is very important in the present invention to select the kind and amount of the ester compound to satisfy 0.1 ≦(100-A) × B ≦ 10.0. When the value of (100-A) × B is smaller than 0.1, the effect as a mold release agent is insufficient, and the chloride ion trapping effect due to decomposition of the chlorine-based compound cannot be exhibited, and contamination of the thin plate cannot be suppressed. When the value of (100-A) × B is larger than 10.0, the heat resistance at the time of molding is lowered, and when the polycarbonate resin is decomposed, the amount of the phenol compound is increased, or the molecular weight of the resin is lowered or the color tone is poor. The lower limit of (100-A) × B is preferably 0.5, more preferably 1.0. The upper limit is preferably 7.0, more preferably 5.0. Further, the average degree of esterification and content of the ester compound were measured by a ¹ H-NMR method.

Further, in the present invention, it is preferable to further satisfy the following formula (2).

0.001≦(100-A)×n×B/Mn≦0.1 (2)

(wherein, n represents the number of hydroxyl groups in one molecule of the polyol in the raw material of the ester compound; Mn represents the number average molecular weight of the ester compound).

When the value of (100-A) × n × B / Mn is 0.001 or more, the effect as a mold release agent is sufficient, and the chloride ion trapping effect due to decomposition of the chlorine-based compound can be exhibited, and contamination of the thin plate can be suppressed. When the value of (100-A) × n × B / Mn is 0.1 or less, the heat resistance at the time of molding is excellent, and the polycarbonate resin is hardly decomposed, so that the amount of the phenol compound can be suppressed from increasing, and the molecular weight of the resin is not caused. Reduced or poor color tone. The lower limit of (100-A) × n × B / Mn is preferably 0.01, more preferably 0.03. The upper limit is preferably 0.08, more preferably 0.05. Further, the number average molecular weight of the ester compound is determined by a ¹ H-NMR method.

In the case of a polyhydric alcohol, it is preferred that the number of carbon atoms is from 3 to 32. Specific examples of such a polyol include glycerin, diglycerin, polyglycerin (for example, decaglycerin), pentaerythritol, dipentaerythritol, diethylene glycol, and propylene glycol.

The higher fatty acid means an aliphatic carboxylic acid having 10 to 32 carbon atoms, and specific examples thereof may be exemplified by citric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, and pentadecanoic acid. a saturated aliphatic carboxylic acid such as palmitic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), lauric acid, icosonic acid, behenic acid, or hexamic acid; and soft fat An unsaturated aliphatic carboxylic acid such as palmitoleic acid, oleic acid, linoleic acid, linoleic acid, eicosenoic acid, eicosapentaenoic acid, cetoleic acid or the like . Among these, as the aliphatic carboxylic acid, those having 10 to 22 carbon atoms are preferred, and those having 14 to 20 carbon atoms are more preferred. In particular, it is a saturated aliphatic carboxylic acid having 14 to 20 carbon atoms, particularly preferably stearic acid and palmitic acid. Like the aliphatic carboxylic acid of stearic acid, it is usually a mixture of other carboxylic acid components having different numbers of carbon atoms. In the saturated fatty acid ester, an ester compound obtained from stearic acid or palmitic acid can be preferably used. It is composed of a mixture containing other carboxylic acid components produced from such natural fats and oils.

Specific examples of the ester compound include, for example, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, glyceryl monostearate, and neopentyl stearate. A tetraol ester, propylene glycol monostearate or the like is a main component. Among them, it is preferred to use glyceryl monostearate or neopentyl glycol stearate as a main component. The chloride ion capture effect is preferred because the secondary alcohol is higher than the primary alcohol, so it is particularly preferred to use glyceryl monostearate as a main component. These ester compounds may be used singly or in combination of two or more kinds as long as they are within the range specified by the present invention. Further, when two or more types are used in combination, the average degree of esterification is a weighted average of the respective ester compounds, and the content is the total content of the respective ester compounds.

(content of specific components in the resin composition)

The content of chlorine atoms in the resin composition of the present invention is 5 ppm or less, preferably 3 ppm or less, based on the resin composition. In the case of the chlorine atom, most of the chlorine-based organic solvent used in the production remains in the aromatic polycarbonate resin, and the raw material phosgene contains carbon tetrachloride as an impurity, or A trace of unreacted chloroformate remaining in the polymer chain. When the residual chlorine-based organic solvent is increased, hydrochloric acid generated by decomposition of the chlorine-based organic solvent itself or the chlorine-based organic solvent leaks from the resin and contaminates a thin plate such as a wafer.

The unreacted chloroformic acid group remaining in the polymer chain does not leak out of the polymer itself. However, when the amount is increased, the forming process can subtly promote the decomposition of the polymer and increase the low molecular weight portion, that is, increase. The volatile components are closely related to the contamination of the sheet.

The content of carbon tetrachloride in the resin composition of the present invention is 3 ppm or less, preferably 2 ppm or less, more preferably 1 ppm or less, further preferably 0.5 ppm or less, particularly preferably 0.3 ppm or less, most preferably the resin composition. Preferably, it is 0.1 ppm or less. When the amount of the chlorine-based organic solvent remaining in the aromatic polycarbonate resin increases, hydrochloric acid is generated by decomposition of the chlorine-based organic solvent when heated during molding. It is well known that in the process of preparing aromatic polycarbonate resin by solution method, Carbon tetrachloride has high decomposability compared to methylene chloride which is most commonly used as a solvent. In other words, among the chlorine components in the aromatic polycarbonate resin of the present invention, the carbon tetrachloride content is particularly lowered, which is related to the suppression of hydrochloric acid from the thin plate storage container.

In the present invention, the phenol compound having 6 to 18 carbon atoms refers to a phenol compound composed of a monovalent phenol compound for terminal chain sealing, a dihydric phenol of a raw material, and an additive used in the production of an aromatic polycarbonate resin. .

These are the result of decomposition of an unreacted phenol compound or decomposition of an aromatic polycarbonate resin or an additive. Since the phenol compound having a carbon number of more than 18 has a low volatility, even if the content of the phenol compound having only a carbon number of more than 18 is increased, the influence on the achievement of the present invention is small.

The phenol compound having 6 to 18 carbon atoms in the present invention, specifically, may be exemplified by the above-mentioned raw material dihydric phenol, especially bisphenol A, or the aforementioned phenol which is a monohydric phenol as a terminal blocking agent, and the third-order phenol. Butanol, p-cumyl phenol and isooctyl phenol.

In the present invention, the total content of the phenol compound having 6 to 18 carbon atoms is 40 ppm or less, preferably 35 ppm or less, based on the resin composition. When the content exceeds 40 ppm, the amount of the volatile phenol compound also increases, which may contaminate a thin plate such as a wafer.

In the present invention, the total content of sodium and iron atoms is 0.1 ppm or less, preferably 0.05 ppm or less, based on the resin composition. When the amount is more than 0.1 ppm, the decomposition of the resin is easily promoted by the molding process of the resin composition of the metal, and as a result, the volatile component on the surface of the thin plate is likely to be contaminated.

Further, in the present invention, the thin plate refers to a thin plate which is processed into a disk, a hard disk or a disk represented by an MO and an integrated circuit wafer, and the like, which is sensitive to surface contamination.

The chlorine atom content in the resin composition of the present invention is determined by a combustion chlorine method. Further, the carbon tetrachloride content was measured by headspace gas chromatography. Further, the phenol compound content was measured by a high speed liquid chromatography method. Further, the content of sodium and iron atoms was measured by a heat-induced ashing treatment according to an inductively coupled plasma ‧ mass spectrometry (ICP-MS method).

(Method of reducing specific components in the resin composition)

In the present invention, a method of reducing a chlorine-based organic solvent or a phenol compound having a carbon number of 6 to 18 remaining in the resin composition can be exemplified by, for example, a method of drying an aromatic polycarbonate resin; Method for drying an enlarged aromatic polycarbonate resin; a method for washing an aromatic polycarbonate resin powder and granules with a poor solvent, and then fortifying the aromatic polycarbonate resin powder and granules The method of de-evaporation, etc.

In order to enhance the drying of the aromatic polycarbonate resin, in particular, it is effective to increase the drying temperature. However, the temperature set above the softening temperature of the aromatic polycarbonate resin is not preferable, and drying is usually carried out at 90 to 140 °C. Further, there is a method of prolonging the drying time or increasing the stirring efficiency of the aromatic polycarbonate resin during drying.

In order to increase the surface area of the aromatic polycarbonate resin, in particular, it is preferably a powder shape which reduces the particle diameter of the aromatic polycarbonate resin, and therefore, pulverization using a reinforced aromatic polycarbonate resin can be used. The method of waiting. In particular, when the dried resin is pulverized, since the particles are too hard and the efficiency is deteriorated, it is preferred to pulverize the slurry-containing material containing the organic solvent or water after granulation. Further, it is also effective to form a porous powder. For example, an aromatic polycarbonate resin solution dissolved in a good solvent is set to a temperature which is relatively higher than the boiling point of the good solvent, and is dropped to a poor solvent. Stir and granulate.

The phenol compound in the aromatic polycarbonate resin is extracted into a poor solvent by using an aromatic polycarbonate resin in a poor solvent, in particular, a method of washing the resin powder. Further, this method also has the effect of reducing the chlorine-based organic solvent in the aromatic polycarbonate resin by such a poor solvent and reducing the effect of the chlorine-based organic solvent. In terms of a poor solvent, it may be exemplified by acetone, methanol, heptane or the like, and among them, acetone is preferably used.

In the method of enhancing de-evaporation when the aromatic polycarbonate resin powder or granules are melted and extruded, specifically, a method of increasing the de-evaporation area in the melt extruder can be used.

Further, there is also a method in which the devolatization pressure is set to be low, or a devolatization aid such as water is used.

The method for reducing carbon tetrachloride in the resin composition can be exemplified by a method for reducing the introduction of carbon tetrachloride according to the decrease in the concentration of carbon tetrachloride in the phosgene of the raw material, and specifically, it can be exemplified as : adsorption removal of carbon tetrachloride by activated carbon; or separation and removal of carbon tetrachloride produced by phosgene by distillation using a difference in boiling point between phosgene and carbon tetrachloride. Further, in the case of using a dichloromethane having a small amount of carbon tetrachloride, in the case where the dichloromethane is continuously and recycled, a part or the whole amount of the recycled dichloromethane is operated by distillation or the like. A method of removing carbon tetrachloride in methylene chloride is removed.

In order to reduce the chloroformic acid group in the aromatic polycarbonate resin, a catalyst may be used during the polymerization, or a polymerization time may be sufficiently obtained to complete the polymerization, or the aromatic polycarbonate resin may be an aqueous solution of NaOH or the like. A method in which an alkaline aqueous solution is subjected to a washing treatment.

Further, in the method of reducing the metal atom, a method in which an aromatic polycarbonate resin solution dissolved in a good solvent is mixed with pure water, and the liquid separation is repeated, or a method of filtering by a filter or the like can be used.

(Evaluation of resin composition)

In the case where the resin composition of the present invention is heated and extracted by pure water at 80 ° C for 24 hours, the amount of chloride ions extracted is preferably relative to the aromatic polycarbonate resin composition used for the measurement. 30 ppb or less, more preferably 20 ppb or less, and preferably 15 ppb or less, and particularly preferably 10 ppb or less. When a resin composition having a dissolved chloride ion concentration of more than 30 ppb is used, it not only contaminates a thin plate such as a wafer, but is also likely to be associated with corrosion of a metal device such as a molding machine or a mold. Further, the dissolved chloride ion concentration of the resin composition was measured by ion chromatography (concentration column method).

In the resin composition of the present invention, the mold release load is a glass mold-like mold for evaluation of mold release property, and when the injection molded product is released from the mold, it is measured by a load cell. The mold release load is preferably 250 kgf or less, more preferably 200 kgf or less, and still more preferably 150 kgf or less.

In order to confirm whether or not the resin composition of the present invention is a material suitable for the purpose of the present invention, it is necessary to measure a slight contamination state of the surface of the thin plate accommodated in the thin plate storage and transport container formed by the resin composition. The measurement method is a method of determining how much the contact angle of the wafer surface with water changes before and after the placement when the container is placed for a long time. Since the contact angle is greatly changed at a micron level, even if only the surface is slightly contaminated, it can be used as a simple evaluation method. The contact angle of the pure water obtained by the aromatic polycarbonate resin composition of the present invention with respect to the wafer accommodated in the semiconductor wafer storage and transport container is measured by the Θ/2 method.

(Additive for resin composition)

In the present invention, various additives such as a heat stabilizer and an antioxidant are preferably not used, or the amount of use is minimized.

The heat stabilizer may be formulated in a small amount in order to prevent a decrease in molecular weight or deterioration of color tone and prevent deterioration of the resin during molding of the aromatic polycarbonate resin, and is preferably 50 ppm or less with respect to the aromatic polycarbonate resin. It is preferably 10 to 50 ppm, and preferably 10 to 40 ppm. Within these ranges, it is preferred to volatilize the heat stabilizer or volatilize the heat stabilizer, especially if there is no contamination of the wafer surface.

Examples of such heat stabilizers include: phosphorous acid, phosphoric acid, phosphonic acid, phosphonic acid, and the like, and specifically, triphenyl phosphite. Ester, tris(2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, tri-octadecyl phosphite, dinonyl monophenyl phosphite, Dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, diphosphoric acid (2,6-di-tris-butyl-4-methylphenyl)pentaerythritol ester, 2,2-methylenebis(4,6-di-tributylphenyl)octyl phosphite , bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearyl neopentyl glycol diphosphite, tributyl phosphate, triethyl phosphate, phosphoric acid Trimethyl ester, triphenyl phosphate, diphenyl mono-diphenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4'-linked phenyl diphosphonic acid tetrakis ,4-di-tertiary butylphenyl), dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate Wait. Among them, preferably In order to use 4,4'-linked phenyldiphosphonic acid tetrakis(2,4-di-tert-butylphenyl), trimethyl phosphate, tris(2,4-di-tert-butylbenzene) Ester and dimethyl phenylphosphonate. These heat stabilizers may be used singly or in combination of two or more.

In the resin composition of the present invention, other resins or elastomers, i.e., at a very small ratio, may be blended without departing from the scope of the object of the present invention.

Such other resins may, for example, be polyester resins such as polyethylene terephthalate or polybutylene terephthalate; polyamine resins, polyimine resins, and polyether oximes; Polyamine resin, polyurethane resin, polyphenylene sulfide resin, polyphenylene sulfide resin, polyfluorene resin, polyolefin resin such as polyethylene, polypropylene, etc.; polystyrene resin, acrylonitrile/styrene copolymer ( AS resin), acrylonitrile/butadiene/styrene copolymer (ABS resin), polymethacrylate resin, phenol resin, epoxy resin, and the like.

Further, the elastomer may, for example, be an isobutylene/isoprene rubber, a styrene/butadiene rubber, an ethylene/propylene rubber, an acrylic elastomer, a polyoxyethylene rubber, a polyester elastomer, or a poly An amine-based elastomer, an MBS (methyl methacrylate/styrene/butadiene) rubber which is a core-shell type elastomer, or a MAS (methyl methacrylate/acrylonitrile/styrene) rubber.

In the resin composition of the present invention, any method may be employed in order to blend the same. For example, a tumbler, a V-type mixer, a super mixer, a nauta mixer, a Banbury mixer can be suitably used ( Banbury mixer), blending roll, extruder, etc. The aromatic polycarbonate resin composition thus obtained can be formed into a pellet form as it is or once by a melt extruder, and then produced by a generally known method such as an injection molding method, an extrusion molding method, or a compression molding method. Formed into a molded product. Further, in order to improve the dispersion of the blending component of the aromatic polycarbonate resin and to obtain stable mold release property or physical properties, it is preferred to use a two-axis extruder for melt extrusion.

(Thin plate storage and transport container)

The present invention includes a sheet storage transport container formed of the resin composition.

The thin plate storage transport container is preferably a storage and transport container for a semiconductor wafer.

The thin plate storage transport container is preferably a thin plate storage transfer container called FOSB (Front Opening Shipping Box), which can accommodate a plurality of sheets (10 to 40 pieces, preferably 20 to 30 pieces). ) 300mm or 450mm semiconductor wafer. The size of the container is from 350 mm to 600 mm in width, from 300 mm to 550 mm in depth, and from about 300 mm to 500 mm in height. Further, the container has a shape as disclosed in Japanese Laid-Open Patent Publication No. 2008-141080 or Japanese Laid-Open Patent Publication No. 2012-56639.

(method of improving the shape of the body)

The method for improving the mold release property at the time of molding of the sheet storage container of the present invention includes the following steps: (i) preparing a molding material; and (ii) molding the molding material in a mold to obtain a sheet storage container.

This resin composition was used as a molding material.

The molding material is preferably dried at 80 to 140 ° C for 1 hour or more.

More preferably, it is ideal for drying at 3 to 24 hours at 100 to 130 °C. The formed material after drying is preferably injection-molded at a mold temperature of from 230 to 330 ° C in a range of from 40 to 100 ° C in a mold temperature, and it is preferred to obtain a sheet-storage transfer container.

More preferably, the injection molding is carried out in a range of a cylinder temperature of 260 to 300 ° C and a mold temperature of 60 to 80 ° C, and a sheet storage container is preferably obtained.

When the cylinder temperature is in the range of 230 to 330 ° C and the mold temperature is in the range of 40 to 100 ° C, the surface smoothness of the molded article is good, and it is difficult to contaminate according to the fine particles generated by the friction with the wafer surface to be accommodated, and It is preferred that the additive such as a molding agent is difficult to vaporize.

Example

The examples are described in detail below, but the invention is not limited by the above. In addition, the evaluation is based on the methods described below.

(1) Viscosity average molecular weight

0.7 g of the aromatic polycarbonate powder or granules were dissolved in 100 ml of dichloromethane, and the obtained solution was used to obtain a specific viscosity at 20 ° C using an Ostwald viscometer, and the viscosity average molecular weight (M) was determined by the following formula.

Specific viscosity (η _SP )=(tt ₀ )/t ₀ [t ₀ is the number of seconds of falling of methylene chloride: t is the number of seconds of falling of the sample solution] η _SP /c=[η]+0.45×[η] ² c (but [η] is the ultimate viscosity) [η]=1.23×10 ^-4 M ^0.83 c=0.7

(2) Chlorine atom content

The chlorinated sulfur analyzer TSX10 manufactured by Mitsubishi Chemical Corporation was used and measured according to the combustion chlorine method. Specifically, the sample (particles) is heated in an electric furnace (920 ° C), and the gas is completely vaporized, and the vaporized gas is dehydrated by sulfuric acid, and then adsorbed to an electrolyte (sodium acetate) for chlorine. The potential difference generated by the adsorption is returned to the original potential by potentiometric titration. Calculate the amount of chlorine based on the energy necessary to return to the original potential.

(3) Carbon tetrachloride content

In a 120 ml stainless steel container, 5 g of pellets were placed and stoppered, and after heating at 250 ° C for 2 hours, 1 ml of headspace gas was injected into a gas chromatography apparatus equipped with an electron capture type detector (manufactured by Hitachi, Ltd.). Type 263), measured.

(4) phenolic compound content

The particles were dissolved in dichloromethane, and acetonitrile was added to precipitate a polymer, which was determined by liquid chromatography.

(5) The amount of each metal of sodium and iron

After the particles were subjected to heating and ashing treatment, the measurement was carried out by an inductively coupled plasma-mass spectrometry (ICP-MS method).

(6) ester compound content, average esterification degree and number average molecular weight

3 g of the particles were dissolved in 30 ml of dichloromethane, and the solvent was added in the order of 50 ml of acetone and 200 ml of hexane. Next, the precipitate was filtered, removed, and the filtrate was concentrated and dried to obtain an extract. The extract was dissolved in 1 ml of deuterated chloroform according to a predetermined internal standard, and subjected to ¹ H-NMR measurement. The ester compound content is determined by calculating the amount of the ester compound by the ratio of the peak of the ester compound and the integral value of the internal standard peak. Further, from the results of ¹ H-NMR measurement, the molar ratio of each ester compound (partial ester and full ester) was calculated, and the average degree of esterification was determined by the following formula (3), and the following formula (4) was obtained. The number average molecular weight was obtained. Further, Table 1 shows the average degree of esterification (%) with respect to the full ester.

(wherein: i represents the average degree of esterification; n represents the number of hydroxyl groups in a molecule of the polyol in the starting material; i represents the degree of esterification of the higher fatty acid ester of the polyol; and Ni represents the higher fatty acid of the ester having a degree of esterification i) % of all ester compounds in esters)

(wherein Mn represents a number average molecular weight; n represents the number of hydroxyl groups in one molecule of the polyol in the raw material; i represents the degree of esterification of the higher fatty acid ester of the polyol, and Mi represents the higher fatty acid ester of the polyol having an esterification degree of i; The molecular weight; Ni represents the % of the total ester compound of the polyol higher fatty acid ester having a degree of esterification i).

(7) Dissolved chloride ion concentration

In a clean polyolefin container, 50 g of the obtained pellet and 50 mL of ultrapure water were placed and stoppered, and after standing at 80 ° C for 24 hours, the obtained solution was subjected to an ion layer manufactured by Dionex Co., Ltd. having a separation column IonPacAS12A manufactured by Dionex Corporation. The analyzer DX-120 measures the chloride ion concentration and calculates the concentration in the particles from the obtained results.

(8) demoulding load

After the granules were dried at 120 ° C for 5 hours, an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.: SS75) was used, and the cylinder temperature was 320 degrees, and the mold temperature was 90 degrees, and a glass cup shape (opening outer diameter) was used. The mold for mold release evaluation of 70 mm, the outer diameter of the bottom surface: 63 mm, the height: 20 mm, and the thickness: 4 mm was injection-molded, and the load at the time of demolding was measured by a load cell. The smaller the value, the more excellent the mold release property.

(9) Contact angle

The pellet was dried at 120 ° C for 5 hours, and then injection-molded at a cylinder temperature of 280 ° C, a mold temperature of 70 ° C, and a molding cycle for about 130 seconds to obtain a 300 mm semiconductor wafer storage transfer container (FOSB).

Inserting a predetermined number of semiconductor wafers into the semiconductor wafer storage and transport container, and holding the semiconductor wafer at a normal temperature for one week in the sealed container, and taking out the semiconductor wafer at five places on the surface, and measuring pure water and crystal according to the Θ/2 method. The contact angle of the round surface. Further, in the examples and comparative examples, the contact angle before placement in the container was 4°.

Example 1

In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 2194 parts of ion-exchanged water, 402 parts of a 48% aqueous sodium hydroxide solution, and 575 parts of 2,2-bis(4-hydroxyphenyl) were dissolved therein. After propane and 1.2 parts of acidic sulfite, 1810 parts of dichloromethane were added, and 283 parts of phosgene treated with activated carbon was blown in with stirring at 15 to 25 ° C for 40 minutes. After the phosgene blowing is completed, 72 parts of 48% aqueous sodium hydroxide solution and 18.5 parts of tertiary butyl phenol are added, stirred and emulsified, and after 10 minutes, the mixture is treated with a homomixer, without stirring, at a temperature. The reaction was completed by placing it in the range of 30 to 33 ° C for 3 hours.

After completion of the reaction, 1810 parts of dichloromethane was added, and the mixture was stirred and mixed for 20 minutes, and then allowed to stand, and the organic solvent solution phase of the polycarbonate resin was separated from the aqueous phase. One part of the ion-exchanged water was added to 1 part of the organic solvent solution of the separated polycarbonate resin, and the washing and liquid separation were repeated three times until the conductivity of the water phase was almost the same as that of the ion-exchanged water. The polycarbonate resin organic solvent solution to be washed was filtered through a SUS304 filter having a filtration efficiency of 1 μm, and then 4'-linked phenyldiphosphonic acid tetra(4) was added in an amount of 25 ppm based on the polycarbonate resin. , 4-di-tertiary butylphenyl) ester.

Next, the obtained polycarbonate resin organic solvent solution was charged in a kneader charged with 45 ° C of warm water (occupying a kneader internal space capacity of about 10%) over one hour. Steam was blown in, and dichloromethane was removed by evaporation at an internal temperature of 45 ° C to obtain a mixture of polycarbonate granules and water. The mixture of the granules and the water is pulverized by a pulverizer, and then placed in a mixer hot water treatment tank controlled at a water temperature of 95 ° C, and water is added to obtain a mixing ratio of 25 parts of granules and 75 parts of water. It was mixed by a mixer for 30 minutes. The mixture of the granules and water was separated by a centrifugal separator to obtain a granule containing 3.5% by weight of dichloromethane and 10% by weight of water. Next, the powder or granules were continuously supplied at a speed of 50 kg/Hr (converted polycarbonate resin) at a speed of 50 kg/Hr (converted polycarbonate resin) in a SUS316L controlled heating type groove type two-axis stirring continuous dryer controlled at 140 ° C, and an average drying time of 8 hours. The conditions were dried to obtain a granule having a viscosity average molecular weight of 1.85 × 10 ⁴ and a dichloromethane content of 50 ppm.

Next, Rikemal S-100A (trade name) (main component: glyceryl monostearate) manufactured by Riken Vitamin Co., Ltd., which is 1000 ppm based on the polycarbonate resin, was added to the obtained polycarbonate powder and granules. A two-axis extruder (made by Nippon Steel Works Co., Ltd.: TEX30α) with a 20 μm dish-shaped screen between the two vent holes and the vent hole, and an ion-exchanged water injection port, and a Nota mixer The mixture was stirred for 20 minutes, supplied at a rate of 30 kg/Hr from the raw material supply port, and melted and extruded at a screw rotation rate of 300 rpm, a resin temperature of 280 ° C, and a venting vacuum of 1 kPa. The melted strands were cooled in a cooling bath, and then cut by a cutter to obtain pellets having a diameter of 3 mm and a length of 3 mm. Further, from the ion-exchanged water injection port, ion-exchanged water as a de-evaporation aid was supplied in an amount of 0.5 part by weight based on 100 parts by weight of the polycarbonate resin composition. The pellets (1) to (9) were measured and evaluated for the obtained pellets, and the results are shown in Table 1. The ND system does not meet the detection limit.

Example 2

In Example 1, the same procedure as in Example 1 was carried out except that the amount of the p-tertiary butylphenol added was changed to 14.9 parts.

Example 3

In the first embodiment, the same procedure as in the first embodiment was carried out except that the activated carbon was not used as the raw material phosgene.

Example 4

In Example 1, except for the polycarbonate granules obtained in Example 1, the polycarbonate granules obtained in Comparative Example 4 described later were used as a polycarbonate granule except that the 1:1 mixture was used. Others were carried out in the same manner as in Example 1.

Example 5

In Example 1, except that the polycarbonate granules obtained in Example 1 and the polycarbonate granules obtained in Comparative Example 5 described later were used in a 1:1 blend as polycarbonate granules, The same procedure as in Example 1 was carried out.

Example 6

In the first embodiment, the same procedure as in the first embodiment was carried out except that the amount of Rikemal S-100A (trade name) was changed to 300 ppm, which was manufactured by Riken Vitamin Co., Ltd.

Example 7

In the first embodiment, the same procedure as in the first embodiment was carried out except that the amount of Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd. was changed to 2000 ppm.

Example 8

In Example 1, except that Rikestar-EW-400 (trade name) (main component: pentaerythritol tetrastearate) was added at 3,000 ppm relative to the polycarbonate resin to replace the relative The same procedure as in Example 1 was carried out except that Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd., which is a polycarbonate resin of 1000 ppm.

Example 9

In the first embodiment, Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd. was added, and further added to Rikenmal-EW-400 (trade name), which is 4000 ppm based on the polycarbonate resin. The same procedure as in Example 1 was carried out.

Comparative example 1

In the first embodiment, the same procedure as in the first embodiment was carried out except that pure water was not used as the devolatization aid at the time of melt extrusion.

Comparative example 2

In Comparative Example 1, the same procedure as in Comparative Example 1 was carried out except that the activated carbon treatment of phosgene used as a raw material was not carried out.

Comparative example 3

In the first embodiment, the same procedure as in the first embodiment was carried out except that the amount of phosgene added was changed to 276 parts.

Comparative example 4

In the first embodiment, the same procedure as in the first embodiment was carried out except that the number of times of washing and liquid separation by the ion-exchanged water of the organic solvent solution of the separated polycarbonate resin after the completion of the reaction was changed to one.

Comparative Example 5

In the first embodiment, the same procedure as in the first embodiment was carried out except that the material of the conduction heating type groove type two-axis stirring continuous dryer was changed to SUS304.

Comparative Example 6

In the first embodiment, the same procedure as in the first embodiment was carried out except that Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd. was not added.

Comparative Example 7

In Example 1, except that 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate was added in an amount of 50 ppm relative to the polycarbonate resin instead of the polycarbonate. The same procedure as in Example 1 was carried out except that the ester resin was 1000 ppm of Rikenmal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd.

Comparative Example 8

In the first embodiment, the same procedure as in the first embodiment was carried out except that the amount of Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd. was changed to 3000 ppm.

Comparative Example 9

In the first embodiment, Rikestar-EW-400 (trade name) manufactured by Riken Vitamin Co., Ltd., which is 300 ppm with respect to the polycarbonate resin, was added in place of the addition of 1000 ppm of the polycarbonate resin to the polycarbonate resin. Other than the Rikemal S-100A (trade name), the same procedure as in Example 1 was carried out.

Comparative Example 10

In the first embodiment, Rikestar-EW-400 (trade name) manufactured by Riken Vitamin Co., Ltd., which is 6000 ppm with respect to the polycarbonate resin, was added in place of the addition of 1000 ppm of the polycarbonate resin to the polycarbonate resin. Other than the Rikemal S-100A (trade name), the same procedure as in Example 1 was carried out.

Effect of the invention

The resin composition of the present invention is excellent in mold release property at the time of molding. Further, the thin plate housing and transporting container of the present invention can reduce the surface contamination of a thin plate such as a semiconductor wafer or a magnetic disk which is sensitive to surface contamination, and the industrial effect which can be achieved is particularly excellent.

Industrial availability

The thin plate storage and transport container of the present invention is extremely useful as a storage and transport container for a thin plate such as a semiconductor wafer or a magnetic disk.

Claims (7)

A resin composition for a thin plate storage and transport container, the resin composition comprising: [I] 100 parts by weight of an aromatic polycarbonate resin; and [II] 0.01 to 0.5 parts by weight (B parts by weight) of an ester compound. The average degree of esterification (A%) composed of a polyol and a higher fatty acid is 30 to 99% of the total ester, wherein the resin composition is characterized by satisfying the following conditions: (i) the chlorine atom content is 5 ppm or less, (ii) The total content of the phenol compound having a carbon tetrachloride content of 3 ppm or less, (iii) the carbon number of 6 to 18 is 40 ppm or less, (iv) the total content of sodium and iron atoms is 0.1 ppm or less, and (v) the following formula ( 1) 0.1 ≦ (100-A) × B ≦ 10.0 (1). The resin composition of claim 1 which satisfies the following formula (2): 0.001 (100-A) × n × B / Mn ≦ 0.1 (2) (wherein n represents a raw material of the ester compound The number of hydroxyl groups in one molecule of the polyol; Mn represents the number average molecular weight of the ester compounds). The resin composition of claim 1, wherein the main component of the ester compound is glyceryl monostearate. The resin composition of claim 1, wherein the aromatic polycarbonate resin has a viscosity average molecular weight of from 1.4 × 10 ⁴ to 3.0 × 10 ⁴ . A thin plate storage transfer container formed by the resin composition of the first aspect of the patent application. The thin plate storage transfer container of the fifth aspect of the patent application is used for a semiconductor wafer. A method for improving mold release property in forming a thin plate storage conveyance container, the method comprising the steps of: (i) preparing a molding material, and (ii) molding the molding material in a mold to obtain a sheet storage conveyance container, the molding material system Contains the following resin compositions: [I] 100 parts by weight of an aromatic polycarbonate resin, and [II] 0.01 to 0.5 part by weight (B parts by weight) of an ester compound, which is an average degree of esterification of a polyol and a higher fatty acid (A%) It is 30 to 99% of the total ester, wherein the resin composition is characterized by using (i) a chlorine atom content of 5 ppm or less, (ii) a carbon tetrachloride content of 3 ppm or less, (iii) carbon. The total content of the phenol compound having a number of 6 to 18 is 40 ppm or less, (iv) the total content of sodium and iron atoms is 0.1 ppm or less, and (v) the following formula (1) 0.1 ≦ (100 - A) × B ≦ 10.0 (1).