JP2008106089A - Polypropylene injection molding semiconductor related parts transport case - Google Patents

Abstract

The present invention provides an injection molded semiconductor-related component carrying case excellent in cleanliness that does not cause deterioration in performance even when a semiconductor-related component such as a silicon wafer or a hard disk is conveyed with very little chlorine and oligomer components.
A polypropylene polymer polymerized with a metallocene catalyst, preferably having a halogen, preferably a chlorine content of 10 ppm by weight or less, and an oligomer component having 1 to 30 carbon atoms, is preferably 10 ppm by weight or less. A semiconductor-related component carrying case.
[Selection figure] None

Description

  The present invention relates to a polypropylene-based injection-molded semiconductor-related component carrying case with a small amount of halogen components and volatile hydrocarbons. More specifically, the present invention relates to a polypropylene-based injection molded semiconductor-related component transport case using a metallocene catalyst and having a very low chlorine content and oligomer components.

Propylene polymers are widely used in various applications such as various industrial materials, various containers, daily necessities, films, and fibers because of their excellent heat resistance, moldability, transparency, and chemical resistance. However, low molecular weight components contained in the polymer and volatile components due to residual substances not only cause generation of smoke and off-flavors during processing, but may also adversely affect odor and hue even after processing.
In recent years, there has been a remarkable spread and development of electronic devices such as computers. Computer-related components use semiconductor-related components such as semiconductor wafer disks and hard disks. In assembling a computer or the like, it is necessary to transport and transfer the semiconductor-related parts to the assembly line. Conventionally, a thermoplastic resin transfer case such as polypropylene has been used for this purpose. Here, the semiconductor-related parts refer to silicon wafers, hard disks, disk substrates, IC chips, magneto-optical disks, high-functional substrate glass for LCDs, LCD color filters, hard disk magnetoresistive heads, and the like.

However, as semiconductor related parts are more highly integrated in order to increase the storage capacity of computers, the frequency with which malfunctions occur in the semiconductor related parts housed in the above transport case increases. Occurred. Specifically, there are problems such as malfunction of the storage disk caused by organic substances and acid gas adhering to the storage disk (for example, see Non-Patent Document 1).
In order to solve the problems related to these polypropylene polymers, a method of washing and removing low molecular weight components after polymerization (for example, see Patent Documents 1 and 2) and a method of separating and removing a liquid phase portion after bulk polymerization (for example, Patent Documents 3 and 4) are proposed, but the amount of oligomer component in the obtained copolymer and the halogen component derived from the catalyst residue are not at a sufficient level by any method, The appearance of a high-quality propylene polymer has been desired.
Ultra-clean technology Toray Research Center (July 2005) Japanese Examined Patent Publication No. 53-4107 Japanese Patent Publication No.58-41283 Japanese Patent Laid-Open No. 10-17612 Japanese Patent Laid-Open No. 10-17613

  The purpose of the present invention is that in the state of the prior art, the molded product has very little chlorine and oligomer components, and injection molding with excellent cleanliness that does not cause performance degradation when transporting semiconductor-related parts such as silicon wafers and hard disks. An object of the present invention is to provide a semiconductor-related component transfer case.

  As a result of various earnest studies, the present inventors cause the above-mentioned problems because trace gases such as halogen components and hydrocarbons generated from semiconductor-related component transport case materials act on semiconductor-related components and deposit. Semiconductor-related parts that do not cause performance degradation when transporting semiconductor-related parts by using polypropylene polymer materials whose trace gases such as hydrocarbons due to this halogen component and oligomer component are below a specific value The present inventors have found that a transport case can be manufactured and have reached the present invention.

  That is, according to the first invention of the present invention, a polypropylene polymer having a halogen content of 10 ppm by weight or less and a C 1-30 oligomer content of 10 ppm by weight or less is formed. A semiconductor-related component transfer case is provided.

  According to a second aspect of the present invention, there is provided a semiconductor-related component transport case according to the first aspect, wherein the halogen is chlorine.

  According to a third aspect of the present invention, there is provided a semiconductor-related component carrying case according to the first or second aspect, wherein the polypropylene polymer is produced using a metallocene catalyst. Is done.

  The semiconductor-related parts transport case of the present invention is less susceptible to contamination of the contents than the conventional case because the content of the oligomer component and halogen content of the polypropylene polymer of the material is small. Very useful for transportation.

  The present invention is a semiconductor-related component transport case molded from a polypropylene polymer having a low oligomer component content and a low halogen content. Hereinafter, the present invention will be described in detail.

  The polypropylene polymer used in the present invention means a homopolymer of propylene or a copolymer of propylene and ethylene and / or an α-olefin having 4 to 20 carbon atoms. Among them, a propylene homopolymer and a random copolymer of propylene and ethylene are preferable. In the case of a random copolymer of propylene and ethylene, the propylene unit is preferably 90 to 99.5% by weight, more preferably 92 to 99% by weight, and the ethylene unit is preferably 0.5 to 10% by weight, more preferably 1 -8% by weight.

The polypropylene polymer used in the present invention has a halogen content contained in the polymer, for example, a chlorine content of 10 ppm by weight or less, preferably 5 ppm by weight or less. A large halogen content is not preferable because it exhibits corrosivity.
Further, the polypropylene polymer used in the present invention has an oligomer component content of 1 to 30 carbon atoms of 10 ppm by weight or less, preferably 8 ppm by weight or less, and more preferably 5 ppm by weight or less. When the content of the oligomer component having 1 to 30 carbon atoms is large, the volatile component is increased, which is not preferable because it adheres to semiconductor-related components.

  The polypropylene polymer used in the present invention can be produced using a known olefin polymerization catalyst, and preferably a metallocene catalyst is used.

  As the catalyst system used for obtaining the polypropylene polymer used in the present invention, a known metallocene catalyst system can be used, but preferably an organoaluminum oxy compound such as methylalumoxane or a fluorine-containing boron compound is used as a co-catalyst. A non-catalytic system is used. Polymerization using an aluminum oxy compound increases the amount of Al present in the produced polymer, and polymerization using a fluorine-containing boron compound increases the amount of halogen present in the produced polymer. In order to obtain a polypropylene polymer having a halogen content according to the present invention, the load of the catalyst removal process must be very large, which is not practical.

In order to obtain a polypropylene-based polymer according to the present invention, it is preferable to use a catalyst system obtained by combining the component [A], the component [B] described below and the component [C] used as necessary.
Component [A] Metallocene complex: Transition metal compound of Groups 4 to 6 in the periodic table having at least one conjugated five-membered ring ligand Component [B] Cocatalyst: Compound [B] is reacted with metallocene complex [A] A compound capable of activating the metallocene complex [A] component [C] an organoaluminum compound

The metallocene catalyst is preferably a supported type. Specific examples of the carrier supporting the metallocene complex include inorganic oxides such as silica and alumina, or organic materials such as polypropylene polymers, and those in which the component [A] is supported in a powdery form or necessary. Correspondingly, the component [C] that is brought into contact with the organoaluminum compound may be mentioned.
A particularly preferred example of the supported metallocene catalyst is an ion-exchange layered silicate in which the carrier also functions as a promoter. Specifically, it is obtained by combining the component [A], the component [B] described below and the component [C] added as necessary.

Component [A] Metallocene complex: Transition metal compound of Groups 4-6 of the periodic table having at least one conjugated five-membered ring ligand Component [B] Cocatalyst: Ion-exchange layered silicate Component [C] Organoaluminum Compound

As the component [A], specifically, a compound represented by the following general formula [1] can be used.
^{_{Q (C 5 H 4-a}} R 1 a) (C 5 H 4-b R 2 b) MXY ··· [1]
In the above general formula [1], Q represents a binding group that bridges two conjugated five-membered ring ligands. M represents a group 4-6 transition metal of the periodic table, and titanium, zirconium, and hafnium are particularly preferable. X and Y are each independently hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, carbon A phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms is shown. R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, a silicon-containing hydrocarbon group, A phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group is shown. Further, two adjacent R ¹ or two R ² may be bonded to each other to form a C4 to C10 ring. a and b are integers satisfying 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4.

  Examples of the binding group Q that bridges between two conjugated five-membered ring ligands include an alkylene group, an alkylidene group, a silylene group, and a germylene group. These may be those in which a hydrogen atom is substituted with an alkyl group, halogen or the like. Specific examples of the metallocene complex include the following compounds.

(1) Methylenebis (cyclopentadienyl) zirconium dichloride (2) Methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium dichloride (3) Isopropylidene (cyclopentadienyl) (3,4 -Dimethylcyclopentadienyl) zirconium dichloride (4) ethylene (cyclopentadienyl) (3,5-dimethylpentadienyl) zirconium dichloride (5) methylenebis (indenyl) zirconium dichloride (6) ethylenebis (2-methylindene) Nyl) zirconium dichloride (7) ethylene 1,2-bis (4-phenylindenyl) zirconium dichloride (8) ethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride (9) dimethylsilylene (cyclope) Tadienyl) (tetramethylcyclopentadienyl) zirconium dichloride (10) dimethylsilylenebis (indenyl) zirconium dichloride (11) dimethylsilylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride (12) dimethylsilylene (12) Cyclopentadienyl) (fluorenyl) zirconium dichloride (13) dimethylsilylene (cyclopentadienyl) (octahydrofluorenyl) zirconium dichloride (14) methylphenylsilylenebis [1- (2-methyl-4,5-benzo (Indenyl)] zirconium dichloride (15) dimethylsilylene bis [1- (2-methyl-4,5-benzoindenyl)] zirconium dichloride (16) dimethylsilylene bis [1- (2-methyl-4) -Azulenyl)] zirconium dichloride (17) dimethylsilylene bis [1- (2-methyl-4- (4-chlorophenyl) -4H-azurenyl)] zirconium dichloride (18) dimethylsilylene bis [1- (2-ethyl-4 -(4-Chlorophenyl) -4H-azulenyl)] zirconium dichloride (19) dimethylsilylenebis [1- (2-ethyl-4-naphthyl-4H-azurenyl)] zirconium dichloride (20) diphenylsilylenebis [1- (2 -Methyl-4- (4-chlorophenyl) -4H-azulenyl)] zirconium dichloride (21) dimethylsilylene bis [1- (2-methyl-4- (phenylindenyl))] zirconium dichloride (22) dimethylsilylene bis [ 1- (2-Ethyl-4- (phenylindene Nyl))] zirconium dichloride (23) dimethylsilylene bis [1- (2-ethyl-4-naphthyl-4H-azulenyl)] zirconium dichloride (24) dimethylgermylenebis (indenyl) zirconium dichloride (25) dimethylgermylene ( Cyclopentadienyl) (fluorenyl) zirconium dichloride

  In addition, the same compounds as described above can be used for other Group 4, 5, and 6 transition metal compounds such as a titanium compound and a hafnium compound. These compounds may be used in combination for the catalyst component and catalyst of the present invention.

  The component [B] ion-exchangeable layered silicate is not limited to a natural product, and may be an artificial synthetic product. A clay compound can be used as the ion-exchange layered silicate. Specific examples of the clay compound include, for example, the following described in Harakuo Shiramizu “Clay Mineralogy” Asakura Shoten (1995): Examples include layered silicates.

(1) Kaolin group such as dickite, nacrite, kaolinite, anorokite, metahalloysite, halloysite, etc., and serpentine group such as chrysotile, lizardite, antigolite etc. (2) Montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite and other smectites, vermiculite such as vermiculite, mica, illite, sericite and sea chlorite Mica, such as attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group

  The silicate used in the present invention may be a layered silicate in which the mixed layers (1) and (2) are formed. In the present invention, the main component silicate is preferably a silicate having a 2: 1 type structure, more preferably a smectite group, and particularly preferably montmorillonite.

The activity can be improved by chemically treating these silicates with an acid, salt, alkali, oxidizing agent, reducing agent, organic solvent or the like.
In addition to removing impurities on the surface of ion-exchangeable layered silicate particles or exchanging interlayer cations, acid treatment can elute some or all of the cations such as Al, Fe, and Mg in the crystal structure. it can.
Examples of the acid used in the acid treatment include hydrochloric acid, nitric acid, sulfuric acid and the like, preferably an inorganic acid, particularly preferably sulfuric acid.
There are no particular limitations on the acid treatment conditions, but preferably the conditions are such that an aqueous solution of 5 to 50% by weight acid is reacted at a temperature of 60 to 100 ° C. for 1 to 24 hours, and the acid concentration is changed during the reaction. May be. After the acid treatment, washing is usually performed. Washing is an operation for separating and removing the acid contained in the treatment system from the ion-exchangeable layered silicate.

Examples of the salts used in the salt treatment include various salts described in JP-A-8-127613. In the present invention, salts containing a specific cation may be selected and used. preferable. As for the kind of the cation, a monovalent to tetravalent metal cation is preferable, and a cation of Li, Ni, Zn, or Hf is particularly preferable. Specific examples of the salts include the following. Examples of the cation with Li include LiCl, LiBr, Li ₂ SO ₄ , Li ₃ (PO ₄ ), Li (ClO ₄ ), Li ₂ (C ₂ O ₄ ), LiNO ₃ , Li (OOCCH ₃ ), Li ₂ (C ₄ H ₄ O ₄ ) and the like. Examples of the cation that is Ni include NiCO ₃ , Ni (NO ₃ ) ₂ , NiC ₂ O ₄ , Ni (ClO ₄ ) ₂ , NiSO ₄ , NiCl ₂ , and NiBr ₂ . Examples of the cation with Zn include Zn (OOCH ₃ ) ₂ , Zn (CH ₃ COCHCOCH ₃ ) ₂ , ZnCO ₃ , Zn (NO ₃ ) ₂ , Zn (ClO ₄ ) ₂ , Zn ₃ (PO ₄ ) ₂ , ZnSO ₄ , ZnF ₂ , ZnCl ₂ , ZnBr ₂ , ZnI _{2 and the} like can be mentioned. As those cations of _{Hf, Hf (OOCCH 3) 4} , Hf (CO 3) 2, Hf (NO 3) 4, Hf (SO 4) 2, HfOCl 2, HfF 4, HfCl 4, HfBr 4, HfI ₄ etc. can be mentioned.

  After the chemical treatment, drying is performed. In general, the drying temperature can be 100 to 800 ° C., and high temperature conditions (for example, 800 ° C. or more depending on the heating time) that cause structural destruction are as follows. It is not preferable. Since the characteristics change depending on the drying temperature even if the structure is not destroyed, it is preferable to change the drying temperature according to the application. The drying time is usually 1 minute to 24 hours, preferably 5 minutes to 4 hours, and the atmosphere is dry air, dry nitrogen, dry argon, or reduced pressure. It does not specifically limit regarding a drying method, It can implement by various methods.

The organoaluminum compound of component [C] is a component that is optionally used as necessary, and a compound represented by general formula [2] is suitable.
^{_{(AlR 4 p X 3-p}} ) q ··· [2]
The organoaluminum compounds can be used alone, in combination of two or more, or in combination. The organoaluminum compound can be added and used not only at the time of catalyst preparation but also at the time of preliminary polymerization or main polymerization.
In formula [2], R ⁴ represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen, hydrogen, an alkoxy group, or an amino group. p is an integer of 1 to 3, and q is an integer of 1 to 2. R ⁴ is preferably an alkyl group, and X is preferably an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and an amino group having 1 to 8 carbon atoms when it is an amino group. Of these, trialkylaluminum and dialkylaluminum hydride having p = 3 and q = 1 are preferable. More preferably, R ⁴ is a trialkylaluminum having 1 to 8 carbon atoms.

The metallocene catalyst used in the present invention is preferably pre-polymerized before the main polymerization. As monomers used for the prepolymerization, α-olefins such as ethylene, propylene, 1-butene and 1-hexene, diene compounds such as 1,3-butadiene, and vinyl compounds such as styrene and divinylbenzene can be used. .
This prepolymerization is preferably carried out under mild conditions in an inert solvent, and is 0.01 to 1000 g, preferably 0.1 to 100 g, per 1 g of the solid catalyst (total of component [A] and component [B]). It is desirable to carry out such that a polymer of

The polymerization reaction is performed in the presence or absence of an inert hydrocarbon such as butane, pentane, hexane, heptane, toluene, cyclohexane, or a solvent such as a liquefied α-olefin. In the present invention, it is desirable to increase the amount of polymer produced per solid catalyst (when the solid catalyst is prepolymerized, the polymer produced by the prepolymerization is not included). In order to increase the polymer production amount, it is desirable to set both the polymerization temperature and the polymerization pressure higher.
Usually, the polymerization temperature is selected from 60 to 90 ° C., and the polymerization pressure is selected from about 1.5 to 4 MPa. In particular, in the case of bulk polymerization, the polymerization temperature is preferably 60 to 80 ° C., and the polymerization pressure is preferably selected from about 2.5 to 4 MPa in correlation with the temperature. On the other hand, in the case of gas phase polymerization, the polymerization temperature is preferably 70 to 90 ° C., and is preferably selected from about 1.5 to 4 MPa. Furthermore, it is possible to increase the polymer production amount per solid catalyst by increasing the residence time of the solid catalyst, but if it is too long, the productivity will be affected. The preferred residence time is 1 to 8 hours, more preferably 1 to 6 hours. It is desirable to set the polymerization conditions so that the polymer production amount per 1 g of the solid catalyst including the carrier is 20 kg or more, preferably 25 kg or more, more preferably 30 kg or more. Further, hydrogen may be present as a molecular weight regulator in the polymerization system. Furthermore, the polymerization may be carried out in multiple stages by changing the polymerization temperature, the concentration of the molecular weight regulator and the like.

In the present invention, after completion of the polymerization, the obtained propylene-based polymer is more preferably an inert saturated hydrocarbon solvent such as propane, butane, pentane, hexane, heptane, liquid α-olefin, etc. Washing is preferably performed using 3 or 4 inert hydrocarbon solvent or liquid α-olefin.
The washing method is not particularly limited, and a known method such as decantation of the supernatant after the contact treatment in the stirring tank, countercurrent washing, and separation from the washing solution by a cyclone can be used. Moreover, you may add a quenching agent before washing | cleaning or simultaneously with washing | cleaning. The quenching agent is not particularly limited, and water, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone and methyl ethyl ketone, or a mixture thereof can be used.

  An appropriate concentration of a phenolic antioxidant or a hindered amine additive can be added to the polypropylene polymer of the present invention.

In order to produce a semiconductor-related component transport case using the polypropylene polymer used in the present invention, a propylene resin composition containing the above-described additive in the polypropylene polymer described above is prepared by a known method. Obtained by injection molding.
Here, the semiconductor-related parts are not particularly limited, but examples thereof include silicon wafers, hard disks, disk substrates, IC chips, magneto-optical disks, LCD high-functional substrate glasses, LCD color filters, and hard disk magnetoresistive heads. That means.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by these examples without departing from the gist thereof. In the following examples and comparative examples, the physical properties of the polymers are measured according to the following methods.

(1) Melt flow rate (MFR): Measured according to JIS-K6921-2: 1997 appendix (230 ° C., 21.18 N load).
(2) Melting point (Tm): Using a DSC manufactured by Seiko Co., Ltd., a sample amount of 5.0 mg was taken, held at 200 ° C. for 5 minutes, and then crystallized to 40 ° C. at a temperature lowering speed of 10 ° C./min. This was evaluated for the peak temperature when held for 1 minute and further melted at a heating rate of 10 ° C./min.
(3) Measurement of ethylene content: The ethylene unit content (unit: wt%) in the polymer derived from ethylene comonomer was measured by pressing the obtained polymer and molding it into a sheet by the IR method. Specifically, it was calculated from the peak height derived from the methylene chain observed at around 730 cm ⁻³ .
(4) Measurement of the amount of oligomer components having 1 to 30 carbon atoms: An injection molded molded product is cut out at 2 mm × 50 mm, 200 mg of a sample is filled in a TGS tube manufactured by GERSTEL, and the TDS tube is inserted into a TDS-A device manufactured by GERSTEL Then, heating at 100 ° C. for 30 minutes while flowing He, and during the heating period, gas was introduced into CIS4 manufactured by GERSTEL filled with TENAX, and volatile components generated from the sample were collected by cooling CIS4 to −150 ° C. .
The collected components were introduced into the gas chromatogram by rapid vaporization to 320 ° C. The introduced gas was measured by gas chromatogram / mass spectrometry under the following conditions.
Device: HP6890
Column: DB-5ms 0.25mm x 30m
Temperature: 40 ° C. × 5 min → 10 ° C./min to 300 ° C. × 15 min
Detector: HP5973N
The amount of hydrocarbons is determined by gas chromatogram / mass spectrometry by measuring n-heptane as a solvent and measuring aliphatic straight-chain saturated hydrocarbons having a concentration of 1, 5, and 10 μg / ml and having 20 carbon atoms under the same conditions as the sample. A calibration curve was prepared by measuring the amount of carbon dioxide and quantification was performed in terms of an aliphatic straight saturated hydrocarbon having 20 carbon atoms.
(5) Measurement of Cl amount: 100 mg of an injection-molded sample was collected on a platinum board, burned in a quartz tube tubular furnace, and Cl content in the combustion gas was absorbed with 0.03% -pure water. Cl ⁻ in the absorbing solution was measured by ion chromatography. These operations were performed in the clean booth.
Equipment: Quartz tube tubular furnace AQF-100 model manufactured by Mitsubishi Chemical Corporation Ion chromatograph: ICS-1000 model manufactured by Dionex

(Example 1)
(1) Preparation of catalyst The following operations were carried out under inert gas using deoxygenated and dehydrated solvents and monomers.
(I) Chemical treatment of ion-exchange layered silicate Acid treatment: 1130 g of distilled water and 750 g of 96% sulfuric acid are added to a separable flask and the internal temperature is kept at 90 ° C., where granulated smectite with an average particle size of 25 μm (Mizusawa) 300 g of Benclay SL (Chemical Co., Ltd.) was added and reacted for 5 hours. Washing: Cooled to room temperature in 1 hour and washed with distilled water to pH = 3.69. The washing magnification at this time was 1/10000 or less. The solid at this stage was partially dried and the elution rate by acid treatment was determined to be 33.5%.
Salt treatment: 211 g of lithium sulfate monohydrate was dissolved in 521 g of distilled water, and 100 g (dry weight) of the solid obtained by the acid treatment was further added, followed by stirring at room temperature for 120 minutes. This slurry was filtered, 3000 g of distilled water was added to the obtained solid, and the mixture was stirred for 5 minutes at room temperature. The slurry was further filtered. To the obtained solid, 2500 g of distilled water was added, stirred for 5 minutes, and then filtered again. This operation was repeated four more times. The obtained solid was pre-dried at 130 ° C. for 2 days under a nitrogen stream, and then coarse particles of 53 μm or more were removed, followed by drying under reduced pressure at 200 ° C. for 2 hours to obtain chemically treated smectite.
(Ii) Silicate activation treatment 200 g of the above chemically treated smectite was introduced into a glass reactor equipped with a stirring blade having an internal volume of 3 L, and 750 ml of normal heptane and further a heptane solution of trinormal octyl aluminum (500 mmol) were added. And stirred at room temperature. After 1 hour, the mixture was washed with normal heptane (residual liquid ratio less than 1%) to prepare a slurry of 2000 mL.
(Iii) Preparation of prepolymerization catalyst Next, (r) -dimethylsilylenebis [2-methyl-4- (4-chlorophenyl) -4H-azurenyl] zirconium dichloride 3 mmol toluene slurry 870 mL and triisobutylaluminum (15 mmol) A mixed solution obtained by reacting 42.6 mL of a heptane solution in advance at room temperature for 1 hour was added to the above chemically treated smectite slurry and stirred for 1 hour. Subsequently, 2.1 L of normal heptane was introduced into a stirring autoclave having an internal volume of 10 L which had been sufficiently substituted with nitrogen, and maintained at 40 ° C. The previously prepared montmorillonite / complex slurry was introduced there. When the temperature was stabilized at 40 ° C., propylene was supplied at a rate of 100 g / hour, and the temperature was maintained. After 4 hours, the propylene feed was stopped and maintained for another 2 hours. About 3 L of the supernatant was removed from the recovered prepolymerized catalyst slurry, 170 mL of a heptane solution of triisobutylaluminum (30 mmol) was added, stirred for 10 minutes, and then heat-treated at 40 ° C. under reduced pressure. By this operation, a prepolymerized catalyst containing 2.30 g of polypropylene per 1 g of catalyst was obtained.

(2) Production of propylene-ethylene random copolymer Internal phase 270L liquid phase polymerization tank with a stirrer, internal volume 400L deactivation tank, slurry circulation pump, circulation line hydraulic classifier, concentrator, countercurrent pump and A process incorporating a post-treatment system including a deactivation cleaning system consisting of a cleaning liquid receiving tank, a high-pressure degassing system consisting of a double-tube heat exchanger and a fluidized flash tank, and a low-pressure degassing tank and a dryer. Continuous production of ethylene copolymer was carried out. The prepolymerized catalyst produced above was dispersed in liquid paraffin (manufactured by Tonen Inc .: White Rex 335) at a concentration of 15% by weight and introduced into the liquid phase polymerization tank at 0.35 g / hr as a catalyst component. Further, liquid propylene was continuously supplied to this polymerization tank at 40 kg / hr, ethylene at 0.4 kg / hr, hydrogen at 0.25 g / hr, and triisobutylaluminum at 18 g / hr, and the internal temperature was maintained at 70 ° C. Polymerization was performed. A mixed slurry of polymer and liquid propylene was extracted from the liquid phase polymerization tank into a deactivation washing tank so as to be 12.0 kg / hr as a polymer. At this time, the average residence time of the catalyst in the polymerization tank was 1.3 hours. Ethanol was supplied to the deactivation washing tank at 21.0 g / hr as a deactivation agent. Furthermore, liquid propylene was supplied at 40 kg / hr, and the internal temperature was kept at 50 ° C. by heating with a jacket. The polymer was extracted from the lower part of the classifier into a high-pressure degassing tank, further passed through a low-pressure degassing tank, and dried with a dryer. The internal temperature of the dryer was adjusted to 80 ° C. and the residence time was 1 hour, and dry nitrogen at room temperature was further flowed in the countercurrent direction of the powder flow at a flow rate of 12 m ³ / hr. The dried polymer was removed from the hopper. On the other hand, liquid propylene separated from the polymer through a classifier and a concentrator was extracted into a washing liquid receiving tank at 40 kg / hr. The yield of the obtained polymer per 1 g of the solid catalyst was 34.3 kg, ethylene content = 0.75 wt%, MFR = 30.6 g / 10 min, and Tm = 141.7 ° C.

(3) Molding of molded body For 100 parts by weight of the obtained powder, pentaerythryl-tetrakis [3- (3,5-t-butyl-4-hydroxyphenyl) propionate], a phenolic antioxidant, (Ciba Made by Specialty Chemicals Co., Ltd .; hereinafter abbreviated as RA1010.) 0.03 part by weight was added, and after nitrogen sealing with a super mixer, mixed for 3 minutes. Thereafter, the powder was granulated at a cylinder temperature of 180 ° C., a screw rotation speed of 200 rpm, and an extrusion rate of 15 kg / h using a twin-screw extruder TEM35 manufactured by Toshiba Machine Co., Ltd., to obtain polypropylene polymer pellets. . This pellet was molded into a sheet-like molded body having a size of 100 mm × 100 mm and a thickness of 2 mm under conditions of a cylinder temperature of 230 ° C. and a mold temperature of 40 ° C. using an IS100GN molding machine manufactured by Toshiba Machine Co., Ltd. The quantity was measured. The amount of the oligomer component having 1 to 30 carbon atoms in the obtained molded body was 8 wt. ppm, Cl amount is 0.3 wt. ppm. The results are shown in Table 1.

(Comparative Example 1)
(1) Catalyst adjustment (i) Ziegler catalyst adjustment A 100 L reactor equipped with a stirring blade, thermometer, jacket, and cooling coil was charged with Mg (OEt) ₂ : 30 mol, and then Ti (OBu) ₄ was added. The Mg (OEt) ₂ was charged so that the molar ratio of Ti (OBu) ₄ / Mg was 0.60 with respect to magnesium in the charged Mg (OEt) ₂ . Furthermore, 19.2 kg of toluene was charged, and the temperature was raised while stirring. After reacting for 3 hours at 139 ° C., and cooled to 130 ° C., the toluene solution of MeSi _{(OPh) 3,} with respect to the magnesium of the charged Mg _{(OEt) 2} previously, MeSi _(OPh) 3 / Mg The molar ratio was 0.67. The amount of toluene used here was 7.8 kg. After completion of the addition, the reaction was performed at 130 ° C. for 2 hours, and then the temperature was lowered to room temperature, and Si (OEt) ₄ was added. The addition amount of Si _{(OEt) 4,} to the magnesium in the charged Mg _{(OEt) 2} previously, the molar ratio of Si _(OEt) 4 / Mg was set to be 0.056.
Next, toluene was added to the obtained reaction mixture so that the magnesium concentration was 0.57 (mol / L · TOL). Furthermore, diethyl phthalate (DEP) was added so that the molar ratio of DEP / Mg was 0.10 with respect to magnesium in Mg (OEt) ₂ charged previously. The resulting mixture was cooled to −10 ° C. with continued stirring, and TiCl ₄ was added dropwise over 2 hours to obtain a uniform solution. Incidentally, TiCl _4, relative to the magnesium of the charged Mg _{(OEt) 2} previously was such that the molar ratio of TiCl ₄ / Mg is 4.0. After completion of the addition of TiCl ₄ , the temperature was raised to 15 ° C. at 0.5 ° C./min with stirring, and kept at the same temperature for 1 hour. Next, the temperature was raised again to 50 ° C. at 0.5 ° C./min, and kept at the same temperature for 1 hour. Further, the temperature was raised to 118 ° C. at 1 ° C./min, and the treatment was performed at the same temperature for 1 hour. After completion of the treatment, stirring was stopped and the supernatant liquid was removed, followed by washing with toluene so that the residual liquid ratio = 1/73 to obtain a slurry.
Next, toluene and TiCl ₄ were added to the resulting slurry at room temperature. Incidentally, TiCl _4, relative to the magnesium of the charged Mg _{(OEt) 2 previously,} the molar ratio of TiCl 4 / Mg _{(OEt) 2} was set to be 5.0. Toluene was prepared so that the TiCl ₄ concentration was 2.0 (mol / L · TOL). The slurry was heated with stirring and reacted at 118 ° C. for 1 hour. After completion of the reaction, stirring was stopped and the supernatant liquid was removed, followed by washing with toluene so that the residual liquid ratio = 1/150 to obtain a solid component slurry. Furthermore, 400 g of the solid component obtained above was transferred to another reactor having a stirring blade, a thermometer, and a cooling jacket, and normal hexane was added to give a solid component concentration of 5.0 (g / l). ). Trimethylvinylsilane, TEA and TMBDES were added at 15 ° C. while stirring the resulting slurry. Here, TBMDES represents t-butylmethyldiethoxysilane, and t-butyl represents a tertiary butyl group. The addition amounts of TEA, trimethylvinylsilane, and TBMDES are 3.1 (mmol), 0.2 (ml), and 0.2 (ml) with respect to 1 g of the solid component in the solid component, respectively. I made it. After completion of the addition, the mixture was kept at 15 ° C. for 1 hour with continuous stirring, further heated to 30 ° C., and stirred at the same temperature for 2 hours.
(Ii) Preliminary polymerization Next, the temperature was lowered again to 15 ° C., and while maintaining the same temperature, 1.2 kg of propylene gas was fed at a constant rate to the gas phase part of the reactor over 72 minutes to perform preliminary polymerization. went. After the feed was completed, the stirring was stopped and the supernatant liquid was removed, followed by washing with normal hexane to obtain a slurry of a prepolymerized catalyst component. The remaining liquid ratio was 1/12. The obtained prepolymerization catalyst component had 3.1 g of propylene polymer per 1 g of the solid component.

(2) Production of propylene-ethylene random copolymer Polymerization was carried out using the same reactor system as used in Example 1. The prepolymerized catalyst component obtained above was dispersed in liquid paraffin (manufactured by Tonen Inc .: White Rex 335) at a concentration of 2% by weight and introduced as a catalyst component at 0.2 g / hr. In this reactor, 32.8 kg / hr of liquid propylene, 0.26 kg / hr of ethylene, 4.0 g / hr of hydrogen, 6.6 g / hr of triethylaluminum, TBEDMS (t-butylmethyldiethoxysilane, where , T-butyl represents a tertiary butyl group) was continuously supplied at 0.011 g / hr, and the internal temperature was maintained at 70 ° C. for polymerization. A mixed slurry of polymer and liquid propylene was extracted from the liquid phase polymerization tank 1 to a deactivation washing tank as a polymer at 13.8 kg / hr. At this time, the average residence time of the catalyst in the polymerization tank was 1.3 hours. Ethanol was supplied to the deactivation washing tank at 21.0 g / hr as a deactivation agent. Furthermore, liquid propylene was supplied at 40 kg / hr, and the internal temperature was kept at 50 ° C. by heating with a jacket. The polymer was extracted from the lower part of the classifier into a high-pressure degassing tank, further passed through a low-pressure degassing tank, and dried with a dryer. The internal temperature of the dryer was adjusted to 80 ° C. and the residence time was 1 hour, and dry nitrogen at room temperature was further flowed in the countercurrent direction of the powder flow at a flow rate of 12 m ³ / hr. The dried polymer was removed from the hopper. On the other hand, liquid propylene separated from the polymer through a classifier and a concentrator was extracted into a washing liquid receiving tank at 40 kg / hr. The yield of the obtained polymer per 1 g of the solid catalyst was 69.0 kg, and the C2 content was 4.2 wt. %, MFR = 25.5 g / 10 min, and Tm = 140.1 ° C.

(3) Molding of molded body Granulation and molding were carried out in the same manner as in the examples. The amount of the oligomer component having 1 to 30 carbon atoms of the polypropylene-based molded product obtained by this method is 14 wt. ppm, Cl amount is 28 wt. ppm. The results are shown in Table 1.

  Since the semiconductor-related parts transport case of the present invention is formed by injection molding from a polypropylene-based polymer having a very low oligomer component content and halogen content, contamination of the contents is extremely unlikely to occur compared to the conventional case, It can be used effectively for transporting semiconductors for highly integrated circuits.

Claims (3)

  A semiconductor-related component carrying case formed by molding a polypropylene polymer having a halogen content of 10 ppm by weight or less and an oligomer component having 1 to 30 carbon atoms of 10 ppm by weight or less.   The semiconductor-related component transfer case according to claim 1, wherein the halogen is chlorine.   The semiconductor-related component carrying case according to claim 1 or 2, wherein the polypropylene-based polymer is a product produced using a metallocene catalyst.