JP2013040304A - Polypropylene-based resin for electric and electronic equipment component transporting case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene-based resin capable of manufacturing an electric and electronic equipment component transporting case in high productivity, the case being excellent in cleanliness without causing deterioration of performances during transportation.SOLUTION: The polypropylene-based resin for the electric and electronic equipment component transporting case is characterized in that a volatile constituent amount A (the unit is ppm) and a melting point T (the unit is °C) satisfy the following formula 1: A≤0.67×T-97, and also that the volatile constituent amount A is 10 ppm or less. Moreover, the melting point T is preferably 150°C or higher and a flexural modulus is preferably 1,300 MPa or more. In addition, it is preferable to use a metallocene catalyst of which the central metal is hafnium to produce the polypropylene-based resin.

Description

  TECHNICAL FIELD The present invention relates to a polypropylene-based resin for a transport case for electrical / electronic equipment parts, and more specifically, an electrical / electronic equipment with excellent cleanliness and high productivity that does not cause deterioration in performance of electrical / electronic equipment parts during transportation or storage. The present invention relates to a polypropylene resin for a component carrying case.

Polypropylene resins 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.
Various components such as silicon wafers, hard disks, disk substrates, IC chips, optical storage disks, high-performance substrate glass for LCDs, LCD color filters, hard disk magnetic head elements, CCD elements, etc. are used in electrical and electronic equipment. In assembling electrical and electronic equipment, in order to use these parts on an assembly line, it is necessary to transport and transfer these parts, and a transport case for this purpose is used. Traditionally, transport cases of thermoplastic resins such as polypropylene have been used for this purpose.

  In recent years, due to miniaturization, higher performance, and higher capacity of electrical and electronic equipment components, contaminants that occur and come into contact with the manufacturing environment, storage, and movement have become a factor in the yield, quality, and reliability of electrical and electronic equipment products. It has come to have a big influence. The low molecular weight components contained in the resin and the volatile components due to residual substances cause not only the generation of smoke and off-flavors during processing, but they may also adversely affect odor and hue after processing. As miniaturization, higher density, and higher integration progress, more sophisticated clean spaces are required.

  And the problem that the frequency which the malfunction in performance generate | occur | produces in the said components accommodated in the conveyance case increases has arisen. For example, 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). By suppressing the generation of organic pollutant gases and moisture generated from the resin material of the transport case, it is expected to prevent deterioration of product quality during product yield, storage and transfer, and to improve reliability.

  In order to solve such problems related to the polypropylene resin, 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, refer to Patent Documents 3 and 4). However, the amount of oligomer components in the obtained resin and the amount of volatile components derived therefrom are sufficient to be sufficient by any method. And the appearance of polypropylene resin with excellent quality has been desired.

  The present applicant has proposed to use a polypropylene-based resin manufactured using a metallocene catalyst as a means for providing a semiconductor-related component carrying case with reduced volatile components (Patent Document 5). However, a polypropylene resin using a metallocene catalyst is prone to deformation of the product unless it takes a long cooling time when injection molding is performed compared to a polypropylene resin manufactured using a Ziegler-Natta catalyst. There was a problem that would become longer.

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 JP 2008-106089 A

  The object of the present invention is to provide a highly clean electrical and electronic equipment component transport case with excellent cleanliness, which has an extremely small amount of volatile components and does not deteriorate performance when transporting electrical and electronic equipment components. It is to manufacture with productivity.

The present inventors have intensively studied to achieve the above-mentioned object, and a trace gas such as hydrocarbons generated from the material for the transport case acts on and deposits on the electric and electronic equipment parts, thereby causing the above-mentioned problems. Focused on. And by using a polypropylene resin in which the relationship between the amount of the volatile component and the melting point satisfies a specific relational expression, the electrical and electronic equipment parts transport case transports volatile components such as hydrocarbons that are below a specific value. -The present inventors have found that it is possible to produce an electrical / electronic equipment component transport case with high productivity without causing performance degradation during storage and the like, shortening the molding cycle, and high productivity.
That is, the present invention provides the following polypropylene-based resin for electric and electronic equipment component carrying cases and electric and electronic equipment parts carrying cases.

[1] Volatile component amount A (unit is ppm) and melting point T (unit is ° C.) satisfy the following formula 1, and volatile component amount A is 10 ppm or less, and transports parts of electrical and electronic equipment Polypropylene resin for cases.
Formula 1 A ≦ 0.67 × T-97
[2] The polypropylene-based resin for electric and electronic equipment component transport cases according to [1] above, wherein the melting point T is 150 ° C. or higher.
[3] The polypropylene-based resin for electrical and electronic equipment component transport cases according to the above [1] or [2], wherein the flexural modulus is 1300 MPa or more.
[4] The polypropylene-based resin for transporting parts of electrical and electronic equipment according to any one of the above [1] to [3], which is produced using a metallocene catalyst having hafnium as a central metal.
[5] An electrical / electronic equipment component transport case obtained by injection molding the polypropylene resin for electrical / electronic equipment component transport case according to any one of [1] to [4].

  The electrical and electronic equipment parts transport case manufactured using the polypropylene resin of the present invention is extremely resistant to contamination of the contents compared to conventional transport cases, and does not deteriorate in performance during transport, and is excellent in cleanliness. Therefore, it is possible to provide a highly productive electrical and electronic equipment component transport case, which is particularly useful for transport cases for semiconductors for highly integrated circuits.

The polypropylene resin for a transport case for electrical and electronic equipment parts of the present invention has a volatile component amount A of 10 ppm or less, and a volatile component amount A and a melting point T of Formula 1:
A ≦ 0.67 × T-97 is satisfied.
Hereinafter, the polypropylene resin used for the electric and electronic equipment component carrying case of the present invention and the method for producing the electric and electronic equipment parts carrying case will be described in detail.

[I] Polypropylene resin The polypropylene resin of 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 resin of the present invention has a volatile component amount of 10 ppm or less, preferably 8 ppm or less, more preferably 5 ppm or less. The reason is as follows. When the transport case contains electrical and electronic equipment parts with high integration and processing accuracy, even if a small amount of volatile components adhere, it is preferable that the amount of volatile components is less than 5 ppm. On the other hand, even when electrical and electronic equipment parts with low integration are stored, if the amount of volatile components exceeds 10 ppm, the volatile components adhere to the electrical and electronic equipment parts, leading to an increase in the frequency of occurrence of malfunctions in the performance of the parts. Therefore, it cannot be used.

The higher the melting point of the polypropylene-based resin, the higher the solidification speed. Therefore, the molding cycle at the time of molding the transport case is shortened and the productivity is improved. Therefore, for example, when a polypropylene resin having a melting point of 160 ° C. is used, even if the amount of the volatile component is 9 ppm, for example, the product productivity is improved, which is permitted. On the other hand, a propylene resin having a low melting point is considered to require high product value by reducing the amount of volatile components to the extent that productivity is lowered.
As a result of examining the amount of volatile components and the melting point using various polypropylene resins from the viewpoint of the productivity and product performance of the transport case, the polypropylene resin satisfying the above formula 1 is the production of the electrical and electronic equipment component transport case. It became clear that it was necessary to achieve both product and product value.
The polypropylene resin is preferably a polypropylene resin that satisfies the following formula 2.
Formula 2 A ≦ 0.67 × T-97.5
More preferably, it is a polypropylene resin satisfying the following formula 3.
Formula 3 A ≦ 0.67 × T-98.0

  Various additions to the polypropylene after polymerization, such as unreacted monomers, low molecular weight compounds, polymerization solvents, solvents, volatile components resulting from the polymerization process of propylene, and antioxidants Volatile components resulting from the agent and the like are included.

As described above, there are many possible causes for the generation of the volatile component, but it is often caused by the polymerization method and the production method of the polypropylene resin.
Polypropylene resin produced with a Ziegler catalyst can be obtained by measuring the weight average molecular weight (Mw) and number average molecular weight (Mn) by GPC, and obtaining Mw / Mn (index of molecular weight distribution). However, it is about 4 to 9, and the content of unreacted monomer, dimer, low molecular weight compound, amorphous component, oligomer, etc. is often high. On the other hand, the Mw / Mn of the polypropylene resin based on the metallocene catalyst is about 2 to 3, and the length of the molecular chain is very uniform, which is considered to cause the generation of volatile components, the unreacted monomer, dimer, low The content of relatively low molecular weight components such as molecular weight compounds, amorphous components, and oligomers is usually as low as 5 ppm or less, 3 ppm or less, and preferably 1 ppm or less. Therefore, it is more preferable to use a polypropylene resin based on a metallocene catalyst because it is more easily possible to stop the cause of generation of volatile components at 10 ppm by weight or less at the raw material stage.

  In the case of a polypropylene resin based on a Ziegler catalyst, the molecular weight distribution is relatively wide and the low molecular weight region is potentially large. In many cases, it is contained in 10 ppm by weight or more such as 12 ppm, 16 ppm, and 19 ppm. Therefore, when using such a polypropylene-based resin, it is necessary to remove volatile components.

  Of course, the volatile component is not only a by-product of polypropylene resin, but also a polymerization solvent, α-olefin such as ethylene, propylene, 1-butene and 1-hexene which are monomers used for copolymerization, catalyst, propane In addition, an inert saturated hydrocarbon solvent such as butane, pentane, hexane, and heptane, a polymer washing solution such as liquid α-olefin, and a polymer such as a recovery solvent may be mixed. Furthermore, since it can be assumed to be mixed from various additives such as antioxidants and processing aids, in order to make the volatile component of the polypropylene resin 10 ppm by weight or less, polymerization, washing of the polymer, extraction, solvent It is necessary to pay attention to measures from all processes and viewpoints including removal of additives and additives.

The polypropylene resin satisfying the above formula 1 can be preferably obtained as follows.
The melting point of the polypropylene-based resin is determined depending on the content of ethylene and / or α-olefin having 4 to 20 carbon atoms, although there are some differences depending on the catalyst system. At this time, by using a metallocene catalyst described later, the amount of volatile components satisfying the formula 1 is obtained at an arbitrary melting point (content of arbitrary ethylene and / or α-olefin having 4 to 20 carbon atoms). When a lower volatile component amount is required at the melting point, or when the volatile component amount does not satisfy Equation 1 at the melting point, a step of removing the volatile component, for example, washing, drying, adsorption What is necessary is just to reduce by such as. When a catalyst other than the metallocene catalyst described later is used, if the amount of the volatile component satisfying Equation 1 is not reached at an arbitrary melting point, the amount is reduced by a step of removing the volatile component, for example, washing, drying, adsorption, etc. Can do.

  The polypropylene resin of the present invention preferably has a melting point T of 150 ° C. or higher. By setting the melting point to 150 ° C. or higher, the molding cycle can be further shortened and productivity can be further increased. The melting point is measured by differential scanning calorimetry (DSC), but is usually measured in a state where an antioxidant is blended in order to prevent deterioration when the temperature is raised to a high temperature. Also in this invention, melting | fusing point T of a polypropylene resin is measured in the antioxidant containing state, and specifically, it measures according to the method described in the postscript Example.

  Further, the flexural modulus of the polypropylene resin of the present invention is preferably 1300 MPa or more, more preferably 1400 MPa or more. A high flexural modulus is preferable because it can prevent the container from being bent and deformed when a silicon wafer or the like is stored in the container.

  In the polypropylene resin of the present invention, the halogen content contained in the polymer, for example, the chlorine content is preferably 10 ppm by weight or less, more preferably 5 ppm by weight or less. A large halogen content is not preferable because it exhibits corrosivity.

  The polypropylene resin of the present invention preferably has a sodium and calcium content of 100 ppm or less. If the sodium and calcium content exceeds 100 ppm, the resin pieces that have peeled off from the molded product may adhere to the stored electrical and electronic equipment parts, which may result in defects due to changes in the electrical characteristics of the attached parts. There is. Since the possibility of a defect increases as the sodium or potassium content is higher, it is 100 ppm or less as a range where no problem occurs. It is more desirable to reduce it to 70 ppm or less, more preferably 50 ppm or less.

The polypropylene resin of the present invention is preferably produced using a metallocene catalyst. As the metallocene catalyst, a known metallocene catalyst system can be used. Preferably, a catalyst system that does not use an organoaluminum oxy compound such as methylalumoxane or a fluorine-containing boron compound as a cocatalyst is used.
Polymerization using an aluminum oxy compound increases the amount of aluminum present in the resulting polymer, and polymerization using a fluorine-containing boron compound increases the amount of halogen present in the generated polymer. In order to obtain a polypropylene resin having a preferable halogen content as described above, a catalyst removing step can be provided as necessary.

As the metallocene complex, it is preferable to use a metallocene compound having hafnium as a central metal, and specific examples thereof include compounds represented by the following general formula [I].
^{_{Q (C 5 H 4-a}} R 1 a) (C 5 H 4-b R 2 b) MXY ··· [I]
In the general formula [I], Q represents a binding group that bridges two conjugated five-membered ring ligands.
M is preferably hafnium.
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. In particular, it is preferable to form a 6-membered ring or a 7-membered ring and to form an indene ring or an azulene ring together with the conjugated 5-membered 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. In particular, a silylene group is preferable.

Specific examples of the metallocene complex include the following compounds.
(1) Methylenebis (cyclopentadienyl) hafnium dichloride (2) Methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) hafnium dichloride (3) Isopropylidene (cyclopentadienyl) (3,4 -Dimethylcyclopentadienyl) hafnium dichloride (4) ethylene (cyclopentadienyl) (3,5-dimethylpentadienyl) hafnium dichloride (5) methylenebis (indenyl) hafnium dichloride (6) ethylenebis (2-methylindene) Nyl) hafnium dichloride (7) ethylene 1,2-bis (4-phenylindenyl) hafnium dichloride (8) ethylene (cyclopentadienyl) (fluorenyl) hafnium dichloride (9) dimethylsilylene (cyclopentadienyl) ( Tramethylcyclopentadienyl) hafnium dichloride (10) dimethylsilylenebis (indenyl) hafnium dichloride (11) dimethylsilylenebis (4,5,6,7-tetrahydroindenyl) hafnium dichloride (12) dimethylsilylene (cyclopentadiene) Enyl) (fluorenyl) hafnium dichloride (13) dimethylsilylene (cyclopentadienyl) (octahydrofluorenyl) hafnium dichloride (14) methylphenylsilylenebis [1- (2-methyl-4,5-benzo (indenyl) ] Hafnium dichloride (15) dimethylsilylene bis [1- (2-methyl-4,5-benzoindenyl)] hafnium dichloride (16) dimethylsilylene bis [1- (2-methyl-4H-azurenyl)] hafnium di Loride (17) dimethylsilylenebis [1- (2-methyl-4- (4-chlorophenyl) -4H-azulenyl)] hafnium dichloride (18) dimethylsilylenebis [1- (2-ethyl-4- (4-chlorophenyl) ) -4H-azurenyl)] hafnium dichloride (19) dimethylsilylenebis [1- (2-ethyl-4-naphthyl-4H-azurenyl)] hafnium dichloride (20) diphenylsilylenebis [1- (2-methyl-4-) (4-Chlorophenyl) -4H-azulenyl)] hafnium dichloride (21) dimethylsilylene bis [1- (2-methyl-4- (phenylindenyl))] hafnium dichloride (22) dimethylsilylene bis [1- (2- Ethyl-4- (phenylindenyl))] hafnium dichloride (23) dimethyl Tylsilylenebis [1- (2-ethyl-4-naphthyl-4H-azurenyl)] hafnium dichloride (24) dimethylgermylenebis (indenyl) hafnium dichloride (25) dimethylgermylene (cyclopentadienyl) (fluorenyl) hafnium dichloride These compounds may be used in combination for the catalyst component and the catalyst.

The metallocene catalyst is preferably a supported type.
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 compound Hafnium complex compound having at least one conjugated five-membered ring ligand Component [B] Cocatalyst Ion exchange layered silicate Component [C] Organoaluminum compound

-Component [A] Metallocene complex compound As component [A], the metallocene catalyst which uses hafnium as a central metal demonstrated by the said general formula [I] is preferable.

Component [B] cocatalyst (ion-exchange layered silicate)
The ion-exchange 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., whose 1: 1 type structure is the main constituent layer (2) Montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite and other smectites, vermiculite such as vermiculite, mica, illite, sericite, 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 the ion-exchange layered silicate particles or exchanging interlayer cations, the acid treatment may 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.

As the salt used in the salt treatment, it is preferable to select and use a salt containing a specific cation. 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.

Component [C] Organoaluminum Compound The organoaluminum compound of component [C] is a component that is optionally used as necessary, and a compound represented by the following general formula [II] is suitable.
^{_{(AlR 3 p X 3-p}} ) q ··· [II]
In formula [II], R ³ 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 ³ 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 ³ is a trialkylaluminum having 1 to 8 carbon atoms.

  The organoaluminum compounds can be used alone or 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.

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 1,000 g, preferably 0.1 g, per gram of the solid catalyst (total of component [A] and component [B]). It is desirable to carry out such that ~ 100 g of polymer is produced.

  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 polypropylene resin is more preferably used with an inert saturated hydrocarbon solvent such as propane, butane, pentane, hexane, heptane, or liquid α-olefin, and more preferably 3 carbon atoms. Alternatively, washing is preferably performed using an inert hydrocarbon solvent or a 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.

-Properties of polypropylene resin The melting point T of the polypropylene resin is preferably 150 ° C or higher. The melting point is a measure of the rigidity and crystallinity of the polypropylene resin. If the melting point of the polypropylene resin is lower than 150 ° C., the crystallinity is low, so that the volatile components cannot be prevented from flowing out from the surface of the molded body. Is unfavorable because it increases. Control of melting | fusing point can be performed by the ratio of the component which copolymerizes with the catalyst which manufactures a polypropylene resin, and propylene.

-Nucleating agent In the polypropylene resin of the present invention, the nucleating agent can be used as long as the elution of volatile components and metal components from the nucleating agent does not cause a problem.

  As a nucleating agent, a sterically hindered amide compound, an organic dicarboxylic acid metal salt, an organic monocarboxylic acid metal salt, a polymer nucleating agent, an organic phosphate metal salt, dibenzylidene sorbitol or a derivative thereof, a metal salt of diterpenic acid, etc. are used. Is done.

-Antioxidants Various types of phenolic antioxidants can be used for polypropylene resins. Specifically, 2,6-di-t-butyl-4-methylphenol (butylated hydroxytoluene), tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propione -To] methane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butyl) Phenyl) butane, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, 1,3,5-trimethyl Preferred is -2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene.
Other antioxidants can be used in combination as long as the effects of the present invention are not impaired. However, when an antioxidant containing phosphorus and sulfur is used, the contained phosphorus and sulfur have an adverse effect on the contents. This is undesirable because it may impair product performance.

  The preferable addition amount of the phenolic antioxidant is in the range of 0.03 to 0.2 parts by weight with respect to 100 parts by weight of the polypropylene resin. If the added amount of the phenolic antioxidant is less than 0.03 parts by weight, the deterioration of polypropylene due to heat cannot be prevented and the amount of volatile components increases, which is not suitable. If the added amount of the phenolic antioxidant exceeds 0.2 parts by weight, there is a concern that outgas derived from the antioxidant may be generated, and the production cost becomes high, and there is a concern that the color of the product may be deteriorated. . In addition, if the blending amount is increased, not only the semiconductor contents are directly contaminated by blooming but also it may be recognized as a volatile component.

Moreover, it is desirable that the lower limit of the addition amount (parts by weight) of the phenolic antioxidant is adjusted so as to satisfy the following formula with respect to 100 parts by weight of the polypropylene resin.
3 × 10 ⁻³ B−0.67
(However, the unit is parts by weight, and B is the molding temperature (° C.). Also, a value less than 0.03 is 0.03.)
In the injection molding, when an electric / electronic equipment component transport case is obtained, it is necessary to increase the molding temperature when the case is large, thin, or has a complicated shape. However, the higher the molding temperature is, the more the thermal deterioration is promoted and the volatile components are increased. Therefore, a large amount of phenolic antioxidant is required. On the other hand, the more the phenolic antioxidant is added, the worse the hue becomes. Therefore, when the moldability, the amount of volatile components and the hue required for practical use of the product are taken into consideration, the addition amount of the phenolic antioxidant represented by the above formula is most effective. Here, the molding temperature refers to the cylinder set temperature of the (injection) molding machine.

-Other components In the polypropylene resin of this invention, another additional arbitrary component can also be mix | blended in the range which does not impair the effect of this invention remarkably. Examples of such optional components include antistatic agents, antifogging agents, metal deactivators, ultraviolet absorbers, dispersants, fillers, flame retardants, colorants, pigments, and fluorescent whitening agents.

-Molding method of conveyance case In order to manufacture an electrical and electronic equipment component conveyance case using the polypropylene resin of the present invention, a polypropylene resin composition containing the above-described additives as necessary is added to the polypropylene resin. Then, a case having a desired shape is formed by injection molding or the like by a known method. The transfer case includes various magazines, trays, boxes, containers, and the like.
Here, the electric and electronic device parts are not particularly limited, but for example, silicon wafer, hard disk, sapphire wafer, disk substrate, IC chip, magneto-optical disk (MO), DVD, BD, various memories, high function for LCD This refers to parts for various electrical and electronic equipment such as substrate glass, LCD color filters, magnetoresistive heads for hard disks, CCDs, CCD devices, and optical equipment semiconductor parts.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is limited to these Examples and is not interpreted.
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):
It measured based on JIS-K6921-2: 1997 appendix (230 degreeC, 21.18N load).

(2) Melting point (T):
Using a differential scanning calorimeter (DSC6200) 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 decreasing rate of 10 ° C./minute for 1 minute. It was held and evaluated by the maximum melting peak temperature when it was further melted at a heating rate of 10 ° C./min.

(3) Ethylene content:
The ethylene unit content (unit:% by weight) in the polymer derived from the ethylene comonomer was measured by pressing the obtained pellet and molding it into a sheet by the IR method. Specifically, it was calculated from the peak height derived from the methylene chain observed in the vicinity of 730 cm ⁻¹ .

(4) Volatile component amount:
200 mg of a cylindrical pellet sample having a diameter of 2 to 4 mm and a length of 2 to 4 mm is filled into a GERSTEL TDS tube, the TDS tube is inserted into a GERSTEL TDS-A apparatus, and helium gas is flowed at a flow rate of 53.9 ml / min. While flowing, the mixture was heated at 100 ° C. for 30 minutes. During the heating time, gas was introduced into CIS4 manufactured by GERSTEL filled with TENAX, and CIS4 was cooled to −150 ° C. to collect volatile components generated from the sample.
The collected components were introduced into the gas chromatogram by rapid heating and 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 minutes → 10 ° C./minute to 300 ° C. × 15 minutes Detector: HP5973N
The amount of hydrocarbons was determined by measuring aliphatic straight-chain saturated hydrocarbons having 20 carbon atoms at concentrations of 1, 5 and 10 μg / ml under the same conditions as the sample using n-heptane as a solvent, and gas chromatogram / mass. Measurement was performed by an analytical method, a calibration curve was prepared, and quantification was performed in terms of an aliphatic straight-chain saturated hydrocarbon having 20 carbon atoms.

(5) Flexural modulus:
The measurement was performed at 23 ° C. in accordance with JIS K7203 “Bending test method of hard plastic”.

(6) Minimum cooling time:
Using a SG220HD molding machine manufactured by Sumitomo Heavy Industries, the cylinder temperature is set to 220 ° C, the mold temperature is set to 20 ° C, and 20 conveyance case models with a thickness of 0.7mm, an inner diameter of 61mm, and a depth of 105mm are continuously formed. When molding, the minimum cooling time during which the model did not buckle or deform was measured.

(7) Product performance After installing the glass plate in the closed conveyance case model and curing at room temperature for half a year, the contamination state of the glass plate was visually observed. Use the following criteria to judge good or bad.
○: No contamination at all ×: Cloudiness can be confirmed.

(Production Example 1)
(1) Preparation of catalyst The following operations were carried out under inert gas using deoxygenated and dehydrated solvents and monomers.
(I) Synthesis of metallocene compound Synthesis of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] hafnium is disclosed in JP-A-11-240909. It carried out according to the method as described in Example 1 of the gazette.
(Ii) Chemical treatment of ion-exchangeable layered silicate 1,700 g of pure water was put into a 5 L separable flask equipped with a stirring blade and a reflux device, and 500 g of 98% sulfuric acid was added dropwise. Further, 300 g of a commercially available granulated montmorillonite (manufactured by Mizusawa Chemical Co., Ltd., Benclay SL, average particle size: 19.5 μm) was added and stirred. Then, it was made to react at 90 degreeC for 2 hours. This slurry was washed with a Nutsche and a suction bottle connected to an aspirator. A 900 ml aqueous solution of 325 g of lithium sulfate monohydrate was added to the recovered cake and reacted at 90 ° C. for 2 hours. The slurry was washed with a Nutsche and a suction bottle connected to an aspirator until pH> 4, and the recovered cake was dried at 120 ° C. overnight. As a result, 270 g of a chemically treated product was obtained. Thereafter, the entire amount was put into a 2 L flask and dried under reduced pressure at 200 ° C. for 6 hours.
(Iii) Preparation of solid catalyst A mixture of 0.223 kg of the dried silicate obtained above and 1.45 liters of heptane was introduced into a metal reactor equipped with a stirrer having an internal volume of 13 liters. 0.79 liter of heptane solution (0.71M) was added to maintain the system temperature at 25 ° C. After the reaction for 1 hour, it was thoroughly washed with heptane, and the silicate slurry was adjusted to 2.0 liters.
(Iv) Preparation of prepolymerization catalyst 9.5 ml of a triisobutylaluminum heptane solution (0.71 M) was added to the slurry and stirred for 10 minutes. Furthermore, a mixture prepared by adding 0.55 liters of heptane to 2.73 g of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] hafnium was introduced. Then, after reacting at room temperature for 1 hour, heptane was added to adjust to 5.6 liters. Subsequently, propylene was supplied at a rate of 111.8 g / hour at a temperature of 40 ° C., and prepolymerization was performed for 4 hours. Further polymerization was carried out for 1 hour.
After completion of the prepolymerization, the remaining monomer was purged and the catalyst was thoroughly washed with heptane. Subsequently, 95 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added, followed by drying at 40 ° C. under reduced pressure. By this operation, 0.656 kg of a prepolymerized catalyst containing 1.94 g of polypropylene per 1 g of dry silicate was obtained.

(2) Production of polypropylene-based resin After the inside of a stirring autoclave having an internal volume of 200 liters was sufficiently substituted with propylene, 45 kg of liquefied propylene was introduced. To this, 470 ml (0.11 mol) of a triisobutylaluminum / n-heptane solution and 4.0 L of hydrogen (as a standard state volume) were added, and the internal temperature was maintained at 30 ° C. Next, 2.26 g of the prepolymerized catalyst was injected with argon to start polymerization, and the temperature was raised to 70 ° C. over 48 minutes. The polymerization temperature was maintained at 70 ° C., and after 2.0 hours, 100 ml of ethanol was added to stop the reaction, and the remaining gas was purged. The yield of the obtained polymer per 1 g of the solid catalyst was 16.9 kg.

(Production Example 2)
(1) Production of polypropylene-based resin After the inside of a stirring autoclave having an internal volume of 200 liters was sufficiently substituted with propylene, 45 kg of liquefied propylene was introduced. To this was added 0.09 kg of ethylene, 470 ml (0.11 mol) of a triisobutylaluminum / n-heptane solution, and 4.1 L of hydrogen (as a standard state volume), and the internal temperature was maintained at 30 ° C. Next, 2.94 g of the prepolymerized catalyst was injected with argon to start polymerization, and the temperature was raised to 70 ° C. over 35 minutes. The polymerization temperature was maintained at 70 ° C., and after 2.0 hours, 100 ml of ethanol was added to stop the reaction, and the remaining gas was purged. The yield of the obtained polymer per 1 g of the solid catalyst was 20.3 kg, and the ethylene content was 0.33 wt%.

(Production Example 3)
(1) Preparation of catalyst (i) As the synthesis of the metallocene compound, (r) -dimethylsilylenebis [2-methyl-4] was synthesized according to the method described in Example 3 of JP-A-11-240909. A prepolymerized catalyst was prepared according to Production Example 1 (1) except that-(4-chlorophenyl) -4H-azurenyl] zirconium dichloride was used.

(2) Production of polypropylene-based resin From a liquid phase polymerization tank with an internal volume of 270 L, a deactivation tank with an internal volume of 400 L, a slurry circulation pump, a circulation line hydraulic classifier, a concentrator, a countercurrent pump, and a washing liquid receiving tank Propylene-ethylene copolymer by a process incorporating a post-treatment system including a deactivation cleaning system, a high pressure degassing system comprising a double tube heat exchanger and a fluidized flash tank, and a low pressure degassing tank and a dryer. Was continuously produced.
The prepolymerized catalyst produced above was dispersed in liquid paraffin (trade name “White Rex 335” manufactured by Tonen Co., Ltd.) at a concentration of 15% by weight and introduced into the liquid phase polymerization tank at 0.35 g / hour as a catalyst component. Further, liquid propylene is supplied to this polymerization tank at 40 kg / hour, ethylene at 0.4 kg / hour, hydrogen at 0.25 g / hour, and triisobutylaluminum at 18 g / hour to keep the internal temperature at 70 ° C. Then, polymerization was performed. A mixed slurry of polymer and liquid propylene was extracted from the liquid phase polymerization tank into a deactivation washing tank as a polymer at 12.0 kg / hour. 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 as a deactivation agent at 21.0 g / hour. Furthermore, liquid propylene was supplied at 40 kg / hour, 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 adjusted to 1 hour. Further, dry nitrogen at room temperature was flowed at a flow rate of 12 m ³ / hour in the countercurrent direction of the powder flow. The dried polymer was removed from the hopper.
On the other hand, the liquid propylene separated from the polymer through the classifier and the concentrator was extracted into a washing liquid receiving tank at 40 kg / hour. The yield of the obtained polymer per 1 g of the solid catalyst was 34.3 kg, and the ethylene content was 0.75 wt%.

(Production Example 4)
(1) Production of solid product 6 L of n-hexane, 5.0 mol of diethylaluminum monochloride (hereinafter “DEAC”) and 12.0 mol of diisoamyl ether were mixed at 25 ° C. for 1 minute and reacted at the same temperature for 5 minutes. Thus, a reaction product liquid (I) was obtained. Titanium tetrachloride (40 mol) was placed in a reactor purged with nitrogen, heated to 35 ° C., and the entire amount of the reaction product liquid (I) was added dropwise thereto over 30 minutes. Thereafter, the mixture was kept at the same temperature for 30 minutes, further heated to 75 ° C., and then reacted for 1 hour. After a predetermined time, it was cooled to room temperature and the supernatant was removed. Next, the operation of adding 40 L of n-hexane and removing the supernatant by decantation was repeated 4 times to obtain 1800 g of a solid product (II). In a state where the total amount of (II) was suspended in 30 L of n-hexane, 1800 g of diisoamyl ether and 3500 g of titanium tetrachloride were added at 20 ° C. over 1 minute and reacted at 85 ° C. for 1 hour. After completion of the reaction, the mixture was cooled to room temperature (20 ° C.), the supernatant was removed by decantation, 40 L of n-hexane was added, the mixture was stirred and allowed to stand for 10 minutes, and the supernatant was removed 5 times. It was dried under reduced pressure to obtain 1700 g of a solid product (III).
(2) Production of prepolymerized catalyst A glass container with a magnetic stirrer with a volume of 3 L was replaced with nitrogen gas, 2 L of purified n-hexane was charged under a nitrogen stream, and the solid product (III) was converted into titanium trichloride as 20. 0 g, DEAC 1.56 g, and the same molar reaction product of diethylene glycol dimethyl ether and DEAC as a molar ratio of solid product (III) to 0.007 were added to prepare a catalyst dispersion. Next, as a first stage prepolymerization treatment, 10.0 g of propylene monomer was blown into the catalyst dispersion liquid maintained at 30 ° C. for 2 hours and absorbed. Next, as a second-stage prepolymerization treatment, a prepolymerized catalyst was prepared by blowing and absorbing the propylene monomer mixed gas having a concentration of carbonyl sulfide of 10,000 ppm into a catalyst dispersion liquid kept at 30 ° C. for 4 hours. Got.
(3) Production of polypropylene-based resin A stainless steel autoclave with a capacity of 50 L was replaced with nitrogen gas, and 23 L of purified n-hexane was charged under a nitrogen stream, and 100 ml of a prepolymerized catalyst (1.00 g of titanium trichloride content, DEAC 6.24 g was added to DEAC 78 mg). Next, hydrogen is charged in a predetermined amount so as to achieve the target MFR, and after raising the temperature to 70 ° C., propylene is injected until it reaches 10 kg / cm ² G, and polymerization is performed for 4 hours while maintaining the temperature and pressure to be constant. went. When the time is up, the propylene supply is stopped, 3 L of methanol is injected into the vessel to deactivate the catalyst, and the unreacted propylene is purged and then separated from the polymerization suspension into a polymer and atactic polypropylene according to a conventional method. It was collected. The yield of the obtained polymer per 1 g of the solid catalyst was 5.0 kg.

Example 1
(1) Production of Resin Composition With respect to 100 parts by weight of the polypropylene resin powder by the metallocene catalyst obtained in Production Example 1, the phenolic antioxidant pentaerythryl-tetrakis [3- (3,5-t- Butyl-4-hydroxyphenyl) propionate] (trade name “IRGANOX 1010” manufactured by BASF) was added in an amount of 0.03 part by weight, and after nitrogen sealing with a super mixer, the mixture was mixed for 3 minutes. Thereafter, the powder was granulated at a cylinder temperature of 200 ° C., a screw rotation speed of 150 rpm, and an extrusion rate of 15 kg / hour using a twin-screw extruder (TEM 35) manufactured by Toshiba Machine Co., Ltd. while sealing the hopper with nitrogen. Pellets were obtained.
Using this pellet, MFR, melting point, amount of volatile components, flexural modulus, measurement of minimum cooling time, and evaluation of product performance were performed. The obtained results are shown in Table 1.

(Example 2)
Polypropylene resin composition pellets were obtained in the same manner as in Example 1 except that the polypropylene resin powder obtained from the metallocene catalyst obtained in Production Example 2 was used. Using this pellet, the melting point, the amount of volatile components, the flexural modulus, the minimum cooling time were measured, and the product performance was evaluated. The obtained results are shown in Table 1.

(Comparative Example 1)
Pellets of a polypropylene resin composition were obtained in the same manner as in Example 1 except that the polypropylene resin powder by the metallocene catalyst obtained in Production Example 3 was used. Using this pellet, the melting point, the amount of volatile components, the flexural modulus, the minimum cooling time were measured, and the product performance was evaluated. The obtained results are shown in Table 1.

(Comparative Example 2)
Pellets of a polypropylene resin composition were obtained in the same manner as in Example 1 except that the polypropylene resin powder by the Ziegler catalyst obtained in Production Example 4 was used. Using this pellet, the melting point, the amount of volatile components, the flexural modulus, the minimum cooling time were measured, and the product performance was evaluated. The obtained results are shown in Table 1.

From the results of Table 1 above, it can be seen that in Examples 1 and 2 using a polypropylene resin that satisfies Formula 1, the minimum cooling time is a small value and the productivity is good. Moreover, a volatile component is also a value of 5 ppm or less, and it is suitable for an electrical and electronic equipment component conveyance case.
On the other hand, since the bending elastic modulus is small in Comparative Example 1, there is a possibility that the deflection may occur due to the weight of the contents when used in the electric and electronic equipment component transport case. The minimum cooling time is also a large value, and it is judged that productivity is not good. From the above, it is unsuitable for the electrical and electronic equipment parts transport case. In Comparative Example 2, the minimum cooling time is long while the melting point is high, and the amount of volatile components is extremely large.
The case for transporting electrical and electronic equipment parts manufactured using the propylene resin composition of the present invention is formed by injection molding from a propylene resin having a very small amount of volatile components. It is difficult to cause contamination of objects and can be used effectively for transporting semiconductors for highly integrated circuits.

  The polypropylene resin of the present invention is shaped into an electrical / electronic equipment component transport case by injection molding or the like, and the electrical / electronic equipment component transport case obtained has excellent cleanliness and productivity that does not cause performance degradation during transportation. Since it is a high transport case, the yield of electrical and electronic equipment parts and the deterioration of quality during transport and storage can be prevented, so that the industrial utility is very high.

Claims (5)

Volatile component amount A (unit: ppm) and melting point T (unit: ° C) satisfy the following formula 1, and volatile component amount A is 10 ppm or less. Resin.
Formula 1 A ≦ 0.67 × T-97   Melting point T is 150 degreeC or more, The polypropylene resin for electrical and electronic equipment component conveyance cases of Claim 1 characterized by the above-mentioned.   The polypropylene-based resin for an electric / electronic equipment component transport case according to claim 1 or 2, wherein the flexural modulus is 1300 MPa or more.   The polypropylene-based resin for an electric / electronic equipment component transfer case according to any one of claims 1 to 3, wherein the polypropylene resin is manufactured using a metallocene catalyst having hafnium as a central metal.   An electrical / electronic equipment component transport case formed by injection-molding the polypropylene resin for electrical / electronic equipment component transport case according to claim 1.