Propylene-based resin composition for transportation case for electrical / electronic device parts

Abstract

To provide a propylene-based resin composition for a conveying case for electric and electronic equipment parts, which suppresses the occurrence of voids, is excellent in cleanliness so as not to cause deterioration in performance of the electric and electronic equipment parts even during conveyance or storage, and has translucency (Opacity) required for realizing a function as the conveying case.SOLUTION: Disclosed is a propylene-based resin composition (X) for electric / electronic device component carrier cases, which is characterized by containing a propylene-based polymer (A) satisfying requirements (A1) - (A5) and a nucleating agent (B) satisfying requirement (B1), while satisfying requirement (X1).

Description

[Technical Field]

[0001] The present invention relates to a propylene-based resin composition for transport cases for electrical and electronic equipment components, and more particularly to a propylene-based resin composition for transport cases for electrical and electronic equipment components that suppresses the generation of voids, has excellent cleanliness so that the performance of the electrical and electronic equipment components does not deteriorate during transport or storage, and has the translucency (opacity) necessary for realizing the function of the transport case. [Background technology]

[0002] BACKGROUND ART Polypropylene resins are characterized by excellent heat resistance, moldability, transparency, and chemical resistance, and are therefore widely used in a variety of applications, including various industrial materials, various containers, daily necessities, films, and fibers. Electrical and electronic equipment uses a variety of parts, 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. When assembling electrical and electronic equipment, these parts must be transported and transferred to be fed to the assembly line, and transport cases are used for this purpose.Traditionally, transport cases made of thermoplastic resins such as polypropylene have been used for this purpose.

[0003] The above-mentioned transport cases are mainly formed by injection molding, and the product rigidity of injection-molded products increases in proportion to the cube of the wall thickness. However, increasing the wall thickness increases the weight of the product, which leads to problems such as a longer cooling time, a longer molding cycle, lower productivity, a larger amount of resin, which negates the benefits of lighter weight, and lower economic efficiency.

[0004] To address this issue, a common approach is to erect ribs on the backside of the molded product to reduce the weight of the molded product while improving its rigidity (see, for example, Patent Document 1). In order to improve product rigidity using a rib structure, the wider the rib on the backside and the thicker the rib portion, the more effective it is. Furthermore, such ribs increase the fluidity of the resin, allowing for a product with good moldability even if the main part is thin-walled. However, the wall thickness of the rib-forming area is thicker than other areas, and cooling is delayed, making it easy for voids to form inside the molded product. In molded products made from transparent materials, the voids are visible. The area takes on a whitish hue, which detracts from the design. Another problem is that the voids are prone to becoming the starting point for fracture in the molded product, reducing its strength. For this reason, wall thickness is currently limited.

[0005] Thin-walled molded products are generally fixed to other components with screws, so bosses are almost always attached as an integral part. As with ribs, the cooling of these bosses is slower than that of other thin-walled parts, which can result in internal voids, resulting in poor appearance and restricting the shape of the molded product from the perspective of strength.

[0006] In order to suppress the generation of such voids, a propylene-based resin molded article using a propylene-based resin composition that satisfies specific performance has been proposed (see, for example, Patent Document 2). However, this does not solve the problems described below, such as the deterioration in performance of electrical and electronic equipment components caused by low-molecular-weight components and residual substances contained in the resin, and the low productivity caused by the slow crystallization of the propylene-based resin.

[0007] In recent years, as electrical and electronic equipment components have become smaller, more powerful, and have higher capacities, contaminants that are generated in the manufacturing environment, during storage, and during transport have begun to have a significant impact on the yield, quality, and reliability of electrical and electronic equipment products.Volatile components from low-molecular-weight components and residual substances contained in resins not only cause smoke and unpleasant odors during processing, but can also have a negative impact on odors and color even after processing.As electrical and electronic equipment components become smaller, denser, and more highly integrated, more highly purified spaces are required.

[0008] For this reason, when manufacturing electrical and electronic equipment components, clean rooms are prepared to create a highly clean space, and to prevent contamination by sebum, hair, sweat, dust, etc. from the operator, electrical and electronic components are typically loaded into in-process transport containers, and all subsequent processing is performed by robots, resulting in product manufacturing without human intervention. When a robot loads electrical and electronic components into an in-process transport container, the container must be translucent. For example, a silicon wafer in-process transport container consists of three components: a top lid, a cassette that holds approximately 20 wafers, and a bottom box. After the robot loads the silicon wafers into the in-process transport container, the bottom box and the top lid are closed with interlocking claws to prevent easy opening. In this state, the robot uses a sensor to check whether the required number of silicon wafers has been loaded into the in-process transport container. If the top lid is too transparent, the sensor will not be able to detect the presence of the container, making it impossible to confirm that the required number of silicon wafers has been loaded with the container lid closed. However, a container top lid with the appropriate translucency (opacity) makes it possible to confirm that the required number of wafers has been loaded even when the lid is closed.

[0009] Furthermore, Patent Document 3 proposes a solution to the problem of voids occurring in propylene-based resins for transporting electrical and electronic components by using various nucleating agents, but no consideration is given to the opacity required to confirm the presence of electronic components inside the container when the container lid is closed. Therefore, there has been a demand for a polypropylene-based resin that has translucency suitable for use in containers for transporting electrical and electronic components and that solves the problem of voids. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-331157 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-118482 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-186065 [Non-patent literature]

[0011] [Non-Patent Document 1] Ultra-clean Technology, Toray Research Center (July 2005) Summary of the Invention [Problem to be solved by the invention]

[0012] In view of the situation of the prior art, an object of the present invention is to provide a propylene-based resin composition for a transport case for electrical and electronic equipment components, which has suppressed generation of voids, is excellent in cleanliness so that the performance of the electrical and electronic equipment components does not deteriorate during transport or storage, and has the translucency (opacity) necessary for realizing the function of the transport case. [Means for solving the problem]

[0013] The present inventors have conducted extensive research to achieve the above object and have discovered that by incorporating a specific nucleating agent into a propylene-based resin that satisfies specific performance properties, voids in the resulting transport case for electrical and electronic equipment components can be suppressed, the case has high productivity, is excellent in cleanliness so that the performance of the electrical and electronic equipment components does not deteriorate during transport or storage, and also satisfies the translucency (opacity) required to function as a transport case, thereby completing the present invention. That is, the present invention provides the following propylene-based resin composition for a carrying case for electrical and electronic equipment components and the following carrying case for electrical and electronic equipment components.

[0014] [1] A propylene-based resin composition (X) for use in a transport case for an electrical / electronic device component, comprising a propylene-based polymer (A) satisfying the following requirements (A1) to (A5) and a nucleating agent (B) satisfying the following requirement (B1), and also satisfying the following requirement (X1): Requirement (A1) The propylene polymer (A) is at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers, and is also a metallocene polymer. Requirements (A2) The propylene polymer (A) has a melt flow rate (MFR, 230° C., 2.16 kg load) in the range of 8 to 40 kg / 10 minutes. Requirements (A3) The propylene polymer (A) has an α-olefin content of 5% by weight or less (provided that the total of propylene and α-olefin in the propylene polymer (A) is 100% by weight). Requirements (A4) The propylene polymer (A) has a molecular weight distribution (weight average molecular weight / number average molecular weight) in the range of 1.5 to 4.0. Requirements (A5) The propylene polymer (A) has an average elution temperature (T50) of 90 to 105°C and an elution dispersity (σ) of 9°C or less, as measured by temperature rising elution fractionation. Requirement (B1) The nucleating agent (B) has a structure represented by the following formula (1). TIFF2026005128000001.tif4187 (In formula (1), R1, R2, and R3 each independently represent an unsubstituted or substituted hydrocarbon group.) Requirements (X1) The propylene resin composition (X) contains 0.002 to 0.007 parts by weight of a nucleating agent (B) based on 100 parts by weight of the propylene polymer (A). [2] The propylene-based resin composition (X) for a transport case for an electrical and electronic device component according to [1], further satisfying the following requirement (X2): Requirements (X2) The propylene-based resin composition (X) for a transport case for electrical and electronic equipment components has a flexural modulus of elasticity of 1300 MPa or more. [3] A case for carrying electrical and electronic equipment components, comprising the propylene resin composition for carrying cases for electrical and electronic equipment components according to [1] or [2]. [Effects of the Invention]

[0015] The transport case for electrical and electronic equipment components manufactured using the propylene-based resin composition of the present invention is useful because it has significantly reduced voids compared to conventional transport cases, has high productivity, is excellent in cleanliness so that the performance of electrical and electronic equipment components does not deteriorate during transport or storage, and has excellent translucency (opacity) necessary for realizing the functionality of the transport case. It is particularly useful as a transport case for semiconductors for highly integrated circuits. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 shows the overall shape of the disk with projections used in the examples. [Figure 2] FIG. 2 is a diagram showing the shape of the protrusions on the protrusion-equipped disk used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0017] The propylene-based resin composition for use in a carrier case for electrical and electronic equipment components of the present invention is characterized by containing a specific amount of a nucleating agent having a specific structure per 100 parts of a propylene-based resin produced using a metallocene catalyst and having a certain melt flow rate, α-olefin content, molecular weight distribution, and elution characteristics. The propylene-based resin composition used in the electrical and electronic equipment component transport case of the present invention and the electrical and electronic equipment component transport case will be described in detail below.

[0018] 1. Propylene-based resin composition of the present invention One embodiment of the present invention is a propylene-based resin composition (X) for carrying cases for electrical and electronic equipment components, which contains a propylene-based polymer (A) satisfying the following requirements (A1) to (A5) and a nucleating agent (B) satisfying the following requirement (B1), and which satisfies the following requirement (X1) (hereinafter also referred to as "propylene-based resin composition (X) of the present invention" or "propylene-based resin composition of the present invention"). Requirement (A1) The propylene polymer (A) is at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers, and is also a metallocene polymer. Requirements (A2) The propylene polymer (A) has a melt flow rate (MFR, 230° C., 2.16 kg load) in the range of 8 to 40 kg / 10 minutes. Requirements (A3) The propylene polymer (A) has an α-olefin content of 5% by weight or less (provided that the total of propylene and α-olefin in the propylene polymer (A) is 100% by weight). Requirements (A4) The propylene polymer (A) has a molecular weight distribution (weight average molecular weight / number average molecular weight) in the range of 1.5 to 4.0. Requirements (A5) The propylene polymer (A) has an average elution temperature (T50) of 90 to 105°C and an elution dispersity (σ) of 9°C or less, as measured by temperature rising elution fractionation. Requirement (B1) The nucleating agent (B) has a structure represented by the following formula (1). TIFF2026005128000002.tif3682 (In formula (1), R1, R2, and R3 each independently represent an unsubstituted or substituted hydrocarbon group.) Requirements (X1) The propylene resin composition (X) contains 0.002 to 0.007 parts by weight of a nucleating agent (B) based on 100 parts by weight of the propylene polymer (A).

[0019] Each item of the propylene-based resin composition of the present invention will be described in detail below.

[0020] (1) Propylene polymer (A) The propylene polymer (A) used in the present invention will be described in detail below.

[0021] Requirement (A1) The propylene polymer (A) used in the present invention is at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers, and is also a metallocene polymer. Among these, propylene homopolymers and random copolymers of propylene and α-olefins (excluding propylene) are preferred. Examples of α-olefins include ethylene, butene-1, hexene-1, and octene-1, with ethylene and butene-1 being preferred.

[0022] (i) Catalyst for Propylene Polymer (A) The propylene-based resin used in the present invention is a metallocene-based polymer produced using a metallocene catalyst. By using a metallocene catalyst, the molecular weight distribution of the resulting propylene-based resin [weight average molecular weight (Mw) / number average molecular weight (Mn)] can be adjusted to 1.5 to 4.0, which is smaller than the molecular weight distribution of approximately 4 to 9 obtained when a Ziegler catalyst is used. This indicates that the molecular chain length is very uniform and that the content of relatively low molecular weight components such as unreacted monomers, dimers, low molecular weight compounds, amorphous components, and oligomers, which are thought to cause the generation of volatile components, is low.

[0023] As the metallocene catalyst, known metallocene catalyst systems can be used, but it is preferable to use a catalyst system that does not use an organoaluminum oxy compound such as methylalumoxane or a fluorine-containing boron compound as a cocatalyst. Polymerization using an aluminumoxy compound results in a large amount of aluminum present in the resulting polymer, while polymerization using a fluorine-containing boron compound results in a large amount of halogen present in the resulting polymer. To obtain a propylene-based resin having the above-mentioned preferred halogen content, the load on the catalyst removal step must be significantly increased, which is not practical.

[0024] The metallocene catalyst is preferably a supported type. A particularly preferred example of the supported metallocene catalyst is an ion-exchanged layered silicate in which the support also functions as a co-catalyst, which is obtained by combining the following components [A], [B], and, if necessary, the component [C].

[0025] Component [A] Metallocene complex Transition metal compounds of groups 4-6 of the periodic table containing at least one conjugated five-membered ring ligand ·Component [B] Promoter Ion-exchange layered silicate Component [C] Organoaluminum compound

[0026] Component [A] Metallocene complex Specifically, the compound represented by the following general formula [I] can be used as the component [A]. Q(C5H 4-a R 1 a )(C5H 4-b R 2 b )MXY ···[I] In the general formula [I], Q represents a linking group that bridges two conjugated five-membered ring ligands. M represents a transition metal of Groups 4 to 6 of the periodic table, and among these, titanium, zirconium and hafnium are preferred. X and Y each independently represent 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, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms, or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms.

[0027] R 1 and R 2 each independently represents 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. 1 or two R 2 are bonded to C4~C 10 It may form a ring, and it is particularly preferred that a six-membered ring or a seven-membered ring is formed, which, together with the above-mentioned conjugated five-membered ring, forms an indene ring or an azulene ring. a and b are integers satisfying 0≦a≦4 and 0≦b≦4. Examples of the bonding group Q that bridges two conjugated five-membered ring ligands include an alkylene group, an alkylidene group, a silylene group, and a germylene group. These may have hydrogen atoms substituted with alkyl groups, halogens, etc. A silylene group is particularly preferred.

[0028] Specific preferred 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-methylindenyl)zirconium dichloride (7) Ethylene 1,2-bis(4-phenylindenyl)zirconium dichloride (8) Ethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride

[0029] (9) Dimethylsilylene(cyclopentadienyl)(tetramethylcyclopentadienyl)zirconium dichloride (10) Dimethylsilylenebis(indenyl)zirconium dichloride (11) Dimethylsilylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride (12) Dimethylsilylene(cyclopentadienyl)(fluorenyl)zirconium dichloride (13) Dimethylsilylene(cyclopentadienyl)(octahydrofluorenyl)zirconium dichloride (14) Methylphenylsilylenebis[1-(2-methyl-4,5-benzo(indenyl)]zirconium dichloride (15) Dimethylsilylenebis[1-(2-methyl-4,5-benzoindenyl)]zirconium dichloride (16) Dimethylsilylenebis[1-(2-methyl-4H-azulenyl)]zirconium dichloride (17) Dimethylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azulenyl)]zirconium dichloride (18) Dimethylsilylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azulenyl)]zirconium dichloride (19) Dimethylsilylenebis[1-(2-ethyl-4-naphthyl-4H-azulenyl)]zirconium dichloride

[0030] (20) Diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azulenyl)]zirconium dichloride (21) Dimethylsilylenebis[1-(2-methyl-4-(phenylindenyl))]zirconium dichloride (22) Dimethylsilylenebis[1-(2-ethyl-4-(phenylindenyl))]zirconium dichloride (23) Dimethylsilylenebis[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 those mentioned above are also preferred as other transition metal compounds of Groups 4, 5 and 6, such as titanium compounds and hafnium compounds. These compounds may be used in combination with the catalyst component and catalyst of the present invention.

[0031] Component [B] Co-catalyst (ion-exchange layered silicate) The ion-exchangeable layered silicate is not limited to a naturally occurring one, but may also be an artificially synthesized product. Clay compounds can be used as the ion-exchangeable layered silicate, and specific examples of clay compounds include the following layered silicates described in "Clay Mineralogy" by Haruo Shiramizu, Asakura Shoten (1995): (1) Kaolin group, such as dickite, nacrite, kaolinite, anoxite, metahalloysite, and halloysite, whose main constituent layers are 1:1 type structures; serpentine group, such as chrysotile, lizardite, and antigorite (2) Smectite group, such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, and stevensite, whose main constituent layers are 2:1 type structures. , vermiculite group such as vermiculite, mica group such as mica, illite, sericite, glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group

[0032] The silicate used in the present invention may be a layered silicate having a mixed layer of the above (1) and (2). In the present invention, the silicate as the main component is preferably a silicate having a 2:1 type structure, more preferably a smectite group silicate, and particularly preferably montmorillonite.

[0033] The activity of these silicates can be improved by chemically treating them with an acid, a salt, an alkali, an oxidizing agent, a reducing agent, an organic solvent, or the like. The acid treatment removes impurities on the surface of the ion-exchange layered silicate particles, exchanges interlayer cations, and also dissolves some or all of the cations such as Al, Fe, and Mg in the crystal structure. The acid used in the acid treatment includes hydrochloric acid, nitric acid, sulfuric acid, etc., but inorganic acids are preferred, and sulfuric acid is particularly preferred. There are no particular restrictions on the acid treatment conditions, but the preferred conditions are a 5 to 50 wt % aqueous acid solution reacted at a temperature of 60 to 100°C for 1 to 24 hours, with the acid concentration being variable during the reaction. 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-exchanged layered silicate.

[0034] The salts used in the salt treatment are preferably selected to contain specific cations, preferably monovalent to tetravalent metal cations, and more preferably Li, Ni, Zn, or Hf cations. Specific examples of salts include the following: Examples of those with a Li cation include LiCl, LiBr, Li2SO4, Li3(PO4), Li(ClO4), Li2(C2O4), LiNO3, Li(OOCCH3), and Li2(C4H4O4). Examples of those with a Ni cation include NiCO3, Ni(NO3)2, NiC2O4, Ni(ClO4)2, NiSO4, NiCl2, and NiBr2. Examples of compounds with a Zn cation include Zn(OOCH3)2, Zn(CH3COCHCOCH3)2, ZnCO3, Zn(NO3)2, Zn(ClO4)2, Zn3(PO4)2, ZnSO4, ZnF2, ZnCl2, ZnBr2, and ZnI2. Examples of compounds with a cation of Hf include Hf(OOCCH3)4, Hf(CO3)2, Hf(NO3)4, Hf(SO4)2, HfOCl2, HfF4, HfCl4, HfBr4, and HfI4.

[0035] After the chemical treatment, drying is carried out. Generally, drying can be carried out at a temperature of 100 to 800°C, and high temperature conditions that cause structural destruction (for example, 800°C or higher, although this depends on the heating time) are not preferred. Even if the structure is not destroyed, the properties change depending on the drying temperature, so it is preferable to change the drying temperature depending on 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 under reduced pressure. There are no particular limitations on the drying method, and various methods can be used.

[0036] Component [C] Organoaluminum compound The organoaluminum compound of component [C] is a component that is optionally used as needed, and is most preferably a compound represented by the following general formula [II]: (AlR 4 p X 3-p ) q [II] In formula [II], 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 or 2. R 4 is preferably an alkyl group, and when X is an alkoxy group, it is preferably an alkoxy group having 1 to 8 carbon atoms, and when X is an amino group, it is preferably an amino group having 1 to 8 carbon atoms. Among these, preferred are trialkylaluminums where p=3 and q=1 and dialkylaluminum hydrides where p=2 and q=1. More preferred are R 4 is a trialkylaluminum having 1 to 8 carbon atoms.

[0037] The organoaluminum compounds can be used alone or in combination, and can be added not only during catalyst preparation but also during prepolymerization or main polymerization.

[0038] (ii) Method for producing propylene polymer (A) The metallocene catalyst used in the present invention is preferably subjected to a prepolymerization treatment before the main polymerization. The monomers to be subjected to the prepolymerization may be 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. This prepolymerization is preferably carried out in an inert solvent under mild conditions, and is desirably carried out so that 0.01 to 1,000 g, preferably 0.1 to 100 g, of polymer is produced per 1 g of solid catalyst (total of component [A] and component [B]).

[0039] The polymerization reaction is carried out in the presence or absence of a solvent such as an inert hydrocarbon such as butane, pentane, hexane, heptane, toluene, or cyclohexane, or a liquefied α-olefin. In the present invention, it is desirable to maximize the amount of polymer produced per solid catalyst (if the solid catalyst has been prepolymerized, this does not include the polymer produced by the prepolymerization). In order to increase the amount of polymer produced, it is desirable to set both the polymerization temperature and polymerization pressure relatively high.

[0040] Typically, 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 the polymerization pressure is preferably selected from about 1.5 to 4 MPa. Furthermore, the polymer production amount per solid catalyst can be increased by increasing the residence time of the solid catalyst, but if it is too long, 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 solid catalyst including the carrier is 20 kg or more, preferably 25 kg or more, more preferably 30 kg or more. Hydrogen may be present in the polymerization system as a molecular weight modifier. Furthermore, the polymerization may be carried out in multiple stages by changing the polymerization temperature, the concentration of the molecular weight modifier, etc.

[0041] In the present invention, after the polymerization is completed, the resulting propylene-based resin is preferably washed with an inert saturated hydrocarbon solvent such as propane, butane, pentane, hexane, or heptane, or a liquid α-olefin, more preferably with an inert hydrocarbon solvent having 3 or 4 carbon atoms or a liquid α-olefin. The washing method is not particularly limited, and known methods such as decantation of the supernatant after contact treatment in a stirring tank, countercurrent washing, and separation from the washing liquid using a cyclone can be used. A deactivator may be added before or at the same time as washing. The deactivator is not particularly limited, and examples thereof include water, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, and mixtures thereof.

[0042] Requirement (A2): Melt flow rate (MFR) The propylene polymer (A) has a melt flow rate (MFR, 230° C., 2.16 kg load) in the range of 8 to 40 kg / 10 min (hereinafter, melt flow rate may be abbreviated as "MFR").

[0043] There is a trade-off between MFR and impact strength: as the MFR value increases, rigidity increases but impact strength decreases. Furthermore, the optimal MFR range is often determined by the shape of the molded product and molding conditions. Thus, the MFR can be appropriately selected within a range that meets the objectives of the present invention, taking into account various physical properties and suitability for the intended use.

[0044] Requirement (A3): α-olefin content The propylene polymer (A) has an α-olefin content of 5% by weight or less (provided that the total of propylene and α-olefin in the propylene polymer (A) is 100% by weight).

[0045] The upper limit of the α-olefin content is 5% by weight or less, preferably 4% by weight or less, more preferably 3% by weight or less, even more preferably 2% by weight or less, particularly preferably 1% by weight or less, and most preferably 0.5% by weight or less, and the lower limit is 0% by weight or more, preferably 0.1% by weight or more, and more preferably 0.2% by weight or more. By setting the α-olefin content to the above-mentioned certain level or less, the rigidity of the transport case for electrical and electronic equipment components molded using the propylene-based resin composition of the present invention is increased, which is preferable because it minimizes deflection of the case due to an increase in size or thinning, and prevents damage to the contents, etc. Furthermore, by setting the ethylene content to the above-mentioned certain level or more, the impact resistance of the transport case for electrical and electronic equipment components molded using the propylene-based resin composition of the present invention is increased, which is preferable because it prevents damage such as cracking when the case is subjected to an external impact, etc.

[0046] A specific example of a propylene-based resin having a preferred α-olefin content is Wintec WMG03 (propylene-ethylene random copolymer: MFR 30 g / 10 min, ethylene content 0.75 wt %, weight-average molecular weight (Mw) 320,000, molecular weight distribution (Mw / Mn) 2.4, metallocene catalyst), manufactured by Japan Polypropylene Corporation.

[0047] Requirement (A4): Molecular weight distribution The propylene polymer (A) has a molecular weight distribution (weight average molecular weight / number average molecular weight) in the range of 1.5 to 4.0.

[0048] The molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the propylene polymer (A) used in the present invention, as determined by gel permeation chromatography (hereinafter sometimes abbreviated as "GPC"), is set to 1.5 to 4.0. The lower limit of the molecular weight distribution is preferably 2.0 or more, more preferably 2.5 or more, and the upper limit is preferably 3.8 or less, more preferably 3.5 or less. When the lower limit of the molecular weight distribution is a certain level or higher, the range of conditions for producing and purifying the propylene-based resin is widened, which is preferable, as it improves production efficiency. On the other hand, when the upper limit is a certain level or lower, it indicates that the length of the molecular chain is very uniform, which is preferable, as it reduces the content of relatively low molecular weight components such as unreacted monomers, dimers, low molecular weight compounds, amorphous components, and oligomers, which are thought to cause the generation of volatile components.

[0049] Requirement (A5): Uniform elution temperature (T50) and elution dispersity (σ) The propylene polymer (A) has an average elution temperature (T50) of 90 to 105°C and an elution dispersity (σ) of 9°C or less, as measured by temperature rising elution fractionation.

[0050] The propylene polymer (A) used in the present invention has an average elution temperature (T50) of 90 to 105°C and an elution dispersity (σ) set to 9°C or less. Here, the average elution temperature is a value based on the elution curve of the polymer obtained by temperature rising elution fractionation using o-dichlorobenzene as a solvent, and represents the temperature at which the cumulative mass of the eluted polymer reaches 50% by mass. The elution dispersity is the value of σ when the cumulative mass elution amount I(t) is defined as expressed by the following mathematical formula (1), assuming that the elution amount obtained by temperature rising elution fractionation follows a normal probability distribution with respect to the elution temperature.

number

[0051] (2) Nucleating agent (B) The nucleating agent (B) contained in the propylene-based resin composition of the present invention satisfies the following requirement (B1).

[0052] Requirement (B1) The nucleating agent (B) has a structure represented by the following formula (1). TIFF2026005128000004.tif4097

[0053] In formula (1), R1, R2 and R3 each independently represent an unsubstituted or substituted hydrocarbon group.

[0054] The use of a nucleating agent having the structure represented by formula (1) results in the formation of dense crystals of the propylene-based resin, which prevents volatile components contained in the carrying case from leaking out of the molded product. It also promotes the crystallization of the propylene-based resin, thereby improving productivity. As mentioned above, molded products for carrying cases for electrical and electronic equipment components have thicker-walled sections, such as ribs, which tend to cool slower than thinner sections, making them more susceptible to void formation within the molded product. The present invention has revealed that the inclusion of the nucleating agent significantly suppresses the formation of voids. While the mechanism is unclear, it is believed that the promotion of crystallization by the nucleating agent reduces the difference in cooling time between the thick and thin sections, thereby reducing the formation of voids.

[0055] The compounds having an unsubstituted or substituted hydrocarbon group defined by R1, R2, and R3 are specifically exemplified by the various compounds shown below. The nucleating agent used in the present invention basically has the performance that can be properly achieved as long as it has the form of the compound of formula (1) above. The various compounds having an unsubstituted or substituted hydrocarbon group depend on the reaction components selected when synthesizing the compound represented by formula (1) used in the present invention, and although they have a slight effect on the reaction yield of the compound of formula (1), they act equally as nucleating agents, and specific examples thereof include the following:

[0056] Compounds of formula (1) in which at least one of the groups R1, R2, and R3 is represented by a branched alkyl group having 3 to 20 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms that is unsubstituted or substituted by one or more alkyl groups having 1 to 20 carbon atoms are preferred.

[0057] In addition, the groups R1, R2 and R3 may each independently be an unsubstituted or one or more of a 1-methylethyl group, a 2-methylpropyl group, a 1-methylpropyl group, a tert-butyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1,1-dimethylpropyl group, a 1-ethylpropyl group, a tert-butylmethyl group, a cyclopropyl group, a 3-methylcyclopropyl group, a 2,2,3,3-tetramethylcyclopropyl group, a cyclopentyl group, a cyclopentylmethyl group, a 2-cyclopentylethyl group, a cyclohexyl group, a cyclohexylmethyl group, a 2-cyclohexylethyl group, a 4-tert-butylcyclohexyl group, a (4-methylcyclohexyl)methyl group, functional groups represented by the following formulas (1-1) to (1-3), an α-cyclohexyl More preferred are compounds of formula (1) represented by 4-tert-butylphenyl, 3-methylbenzyl, 3,4-dimethoxybenzyl, 4-biphenylmethyl, 2-naphthylmethyl, m-tolyl, m-methoxyphenyl, p-tolyl, 4-ethylphenyl, 4-isopropylphenyl, 4-tert-butylphenyl, 2,3-dimethylphenyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,5-di-tert-butylphenyl, 2,4,6-trimethylphenyl or 3,5-di-tert-butyl-4-hydroxyphenyl. [ka] [ka] [ka]

[0058] Specifically, the compounds represented by formula (1) include 1,3,5-tris[2,2-dimethylpropionylamino]benzene, 1,3,5-tris[cyclohexylcarbonylamino]benzene, 1,3,5-tris[4-methylbenzoylamino]benzene, 1,3,5-tris[3,4-dimethylbenzoylamino]benzene, 1,3,5-tris[3,5-dimethylbenzoylamino]benzene, 1,3,5-tris[cyclopentanecarbonylamino]benzene, 1,3,5-tris[1-adamantanecarbonylamino]benzene, 1,3,5 -Tris[2-methylpropionylamino]benzene, 1,3,5-tris[3,3-dimethylbutyrylamino]benzene, 1,3,5-tris[2-ethylbutyrylamino]benzene, 1,3,5-tris[2,2-dimethylbutyrylamino]benzene, 1,3,5-tris[2-cyclohexylacetylamino]benzene, 1,3,5-tris[3-cyclohexylpropionylamino]benzene, 1,3,5-tris[4-cyclohexylbutyrylamino]benzene, 1,3,5-tris[5-cyclohexylvaleroylamino]benzene Benzene, 1-isobutyrylamino-3,5-bis[pivaloylamino]benzene, 2,2-dimethylbutyrylamino-3,5-bis[pivaloylamino]benzene, 3,3-dimethylbutyrylamino-3,5-bis[pivaloylamino]benzene, 1,3-bis[isobutyrylamino]-5-pivaloylaminobenzene, 1,3-bis[isobutyrylamino]-5-(2,2-dimethyl-butyryl)aminobenzene, 1,3-bis[isobutyrylamino]-5-(3,3-dimethyl-butyryl)aminobenzene, 1,3-bis[2,2-dimethylbutyryl amino]-5-pivaloylaminobenzene, 1,3-bis[2,2-dimethylbutyrylamino]-5-isobutyrylaminobenzene, 1,3-bis[2,2-dimethylbutyrylamino]-5-(3,3-dimethylbutyryl)-aminobenzene, 1,3-bis[3,3-dimethylbutyrylamino]-5-pivaloylamino-benzene, 1,3-bis[3,3-dimethylbutyrylamino]-5-isobutyryl-aminobenzene, 1,3-bis[3,3-dimethylbutyrylamino]-5-(2,2-dimethyl-butyrylamino)aminobenzene or 1,3,5-tris[3-(trimethylsilyl)propionylamino]benzene can be mentioned.

[0059] Such compounds can be produced, for example, by the production method described in Japanese Patent Publication No. 2006-518402.

[0060] Among these, compounds of formula (1) in which the groups R1, R2 and R3 are the same group are preferred, and among these, compounds of formula (1) in which R1, R2 and R3 are tert-butyl groups, i.e., 1,3,5-tris[2,2-dimethylpropionylamino]benzene, are particularly preferred.

[0061] (3) Propylene-based resin composition (X) The propylene-based resin composition (X) of the present invention satisfies the following requirement (X1).

[0062] (3-1) Requirements (X1) The propylene resin composition (X) contains 0.002 to 0.007 parts by weight of a nucleating agent (B) based on 100 parts by weight of the propylene polymer (A). By incorporating the nucleating agent (B) in the above amount per 100 parts by weight of the propylene polymer (A), the crystallization of the propylene resin can be promoted, thereby improving productivity. Furthermore, the presence of the nucleating agent can suppress the generation of voids. The content of the nucleating agent (B) is preferably 0.0025 to 0.0065 parts by weight, more preferably 0.003 to 0.006 parts by weight, based on 100 parts by weight of the propylene polymer (A).

[0063] The propylene resin composition (X) of the present invention further satisfies the following requirement (X2).

[0064] (3-2) Requirement (X2): Flexural modulus The propylene-based resin composition (X) for a transport case for electrical and electronic equipment components has a flexural modulus of elasticity of 1300 MPa or more.

[0065] The flexural modulus of the propylene-based resin composition of the present invention is preferably 1000 MPa or more, more preferably 1200 MPa or more, and even more preferably 1300 MPa or more, when measured at 23°C in accordance with JIS K7171 after cutting a multipurpose test piece molded in accordance with JIS K7152-1 to a predetermined size. It is usually 10,000 MPa or less, preferably 7,000 MPa or less, and more preferably 5,000 MPa or less. A high flexural modulus is preferable because it can prevent flexural deformation of a container when a silicon wafer or the like is placed in the container.

[0066] (3-3) Antioxidants The propylene-based resin composition of the present invention can further contain various phenolic antioxidants, such as 2,6-di-t-butyl-4-methylphenol (butylated hydroxytoluene), tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t-pentylphenyl acrylate, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene. It is possible to use other antioxidants in combination within a range that does not impair the effects of the present invention. However, the use of antioxidants containing phosphorus or sulfur is undesirable because the phosphorus or sulfur contained therein may have an adverse effect on the contents and impair the performance of the product.

[0067] The preferred amount of phenolic antioxidant added is preferably in the range of 0.03 to 0.2 parts by weight per 100 parts by weight of polypropylene resin. Adding an amount of phenolic antioxidant of 0.03 parts by weight or more is preferable because it can prevent thermal degradation of polypropylene and suppress an increase in the amount of volatile components. Adding an amount of phenolic antioxidant of 0.2 parts by weight or less is preferable because it suppresses the generation of outgassing due to the antioxidant, reduces production costs, and improves the color of the product. Adding an amount of 0.2 parts by weight or less is also preferable because it suppresses direct contamination of the semiconductor contents due to blooming and is not recognized as a volatile component.

[0068] (3-4) Other additives The propylene-based resin composition of the present invention may also contain other optional additional components within the range that does not significantly impair the effects of the present invention, such as neutralizing agents, lubricants, light stabilizers, antistatic agents, antifogging agents, metal deactivators, ultraviolet absorbers, dispersants, fillers, flame retardants, colorants, pigments, and fluorescent brighteners.

[0069] (3-5) Properties of propylene-based resin compositions Melt flow rate (MFR) There is a trade-off between MFR and other properties: as the MFR value increases, rigidity and moldability improve, but impact strength decreases. Furthermore, the optimal MFR range is often limited by factors such as the shape of the molded product and molding conditions. Thus, the MFR can be appropriately selected within a range that meets the objectives of the present invention, taking into account various physical properties and suitability for the application.

[0070] Void Vacuum voids can occur in the thick parts of molded products. If voids exist in a transport case for electrical and electronic components, not only will they impair the design, but the sensors that monitor the components inside the case may recognize these voids as foreign matter. For these reasons, it is desirable for this application to have as few voids as possible.

[0071] ·Translucency (Opacity) In the case of electrical and electronic parts, especially in the case of silicon wafer containers, There is a process to check that a predetermined number of silicon wafers are present in the sealed container. If the container is too transparent, the sensor may not be able to detect the presence of the predetermined number of silicon wafers. The presence of the container cannot be confirmed, and the silicon wafer is mistakenly recognized as not being sealed in the container. For this reason, translucency (opacity) is necessary for the container for this purpose.

[0072] Charpy impact strength Cases for electrical and electronic components must have the function of protecting the electrical and electronic components inside the case even if they are accidentally dropped. Although it is common to measure the impact strength using the case that will actually be used, if you want to check the suitability of the material for use, it is also possible to create an impact test specimen and measure the Charpy impact strength to make a judgment.

[0073] 2. A case for transporting electrical and electronic equipment components comprising the propylene-based resin composition of the present invention Another embodiment of the present invention is a carrying case for electrical and electronic equipment components, which comprises the propylene resin composition of the present invention. To produce a carrying case for electrical and electronic equipment components using the propylene-based resin composition of the present invention, the propylene-based resin composition is molded into a case of a desired shape by injection molding or the like. The carrying case includes various magazines, trays, boxes, containers, etc. Here, electrical and electronic equipment components are not particularly limited, but include, for example, silicon wafers, hard disks, sapphire wafers, disk substrates, IC chips, magneto-optical disks (MO), DVDs, BDs, various memories, high-performance substrate glass for LCDs, LCD color filters, magnetoresistive heads for hard disks, CCDs, CCD devices, and semiconductor parts for optical equipment.

[0074] Examples of injection molding methods include known molding methods, such as general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding. [Example]

[0075] EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0076] In the following examples and comparative examples, the propylene polymers and propylene resin compositions were evaluated and their physical properties were measured according to the following methods.

[0077] <1. Evaluation and property measurement methods> (1) Melt flow rate (MFR): Measurement was performed in accordance with JIS K7210 (230°C, 2.16 kg load).

[0078] (2) Measurement of ethylene content: The ethylene content (unit: wt%) in the polymer derived from ethylene comonomer was measured by pressing the obtained polymer into a sheet and measuring it by an IR method. -1 The peak height was calculated from the height of the peak derived from the methylene chain observed in the vicinity.

[0079] (3) Measurement of molecular weight and molecular weight distribution: The molecular weight distribution Mw / Mn was calculated by measuring the weight average molecular weight Mw and the number average molecular weight Mn by gel permeation chromatography (GPC) under the following conditions: Apparatus: WATERS GPC (ALC / GPC 150C) Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3 columns in series) Mobile phase solvent: ο-dichlorobenzene Measurement temperature: 140℃ Flow rate: 1.0ml / min Injection amount: 0.2ml

[0080] (4) Melting peak temperature (melting point) (Tm, unit: ° C.): Using a differential scanning calorimeter (DSC), a 5.0 mg sample was taken, the temperature was raised to 200°C to erase the thermal history, and then the sample was held at 200°C for 5 minutes. The temperature was then lowered to 40°C at a rate of 10°C / min to crystallize the sample, and the temperature was then raised again at a rate of 10°C / min to melt the sample. The temperature at the top of the endothermic peak was taken as the melting peak temperature (melting point) (Tm).

[0081] (5) Measurement of mean dissolution temperature (T50) and dissolution dispersion (σ): The mean elution temperature (T50) and elution dispersity (σ) were calculated by temperature rising elution fractionation (TREF). Specifically, the mean elution temperature (T50) is a value based on the elution curve of the polymer, and represents the temperature at which the cumulative mass of the eluted polymer is 50% by mass. The elution dispersity (σ) is the value of σ when the cumulative mass elution amount I(t) is defined as expressed by the following mathematical formula (1), assuming that the elution amount follows a normal probability distribution with respect to the elution temperature.

number

[0082] The elution curve of the polymer was measured as follows. The sample was dissolved in orthodichlorobenzene (containing 0.5 mg / mL BHT) at 140 °C to form a solution. This was then introduced into a TREF column at 140 °C, cooled to 100 °C at a rate of 8 °C / min, then cooled to 40 °C at a rate of 4 °C / min, and held for 10 minutes. The solvent, orthodichlorobenzene (containing 0.5 mg / mL BHT), was then passed through the column at a flow rate of 1 mL / min. The components dissolved in orthodichlorobenzene at 40 °C in the TREF column were eluted for 10 minutes. The column was then heated linearly to 140 °C at a rate of 100 °C / hour, and an elution curve was obtained.

[0083] <Device> (TREF section) TREF column: 4.3mmφ x 150mm stainless steel column Column packing material: 100 μm surface-deactivated glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is water-cooled) Temperature distribution: ±0.5℃ Temperature controller: Chino Corporation Digital Program Controller KP1000 (valve oven) Heating method: Air bath oven Temperature during measurement: 140℃ Temperature distribution: ±1℃ Valve: 6-way valve, 4-way valve (Sample injection section) Injection method: Loop injection method Injection volume: Loop size 0.1 ml Inlet heating method: Aluminum heat block Temperature during measurement: 140℃ (Detection unit) Detector: Fixed wavelength infrared detector FOXBORO MIRAN 1A Detection wavelength: 3.42 μm High-temperature flow cell: Micro flow cell for LC-IR, optical path length 1.5 mm, window shape 2φ×4 mm oblong, synthetic sapphire window plate Temperature during measurement: 140℃ (Pump section) Liquid transfer pump: Senshu Scientific SSC-3461 pump

[0084] <Measurement conditions> Solvent: orthodichlorobenzene (containing 0.5 mg / mL BHT) Sample concentration: 5 mg / mL Sample injection volume: 0.1 mL Solvent flow rate: 1 mL / min

[0085] (6) Measurement of void occurrence rate: Using a Sumitomo Heavy Industries SE180 molding machine, five disks with protrusions, each 2 mm thick and 200 mm in diameter, were molded using the injection molding method with a cylinder temperature of 200°C and a mold temperature of 40°C, and the percentage of protrusions with voids was calculated (unit: %). The state of voids was visually inspected and confirmed by the state of whitening at the base of the protrusions. The overall shape of the disk with protrusions is shown in Figure 1. The shape of the protrusions on the disk with protrusions is shown in Figure 2. The evaluation was carried out as follows: ◯: No voids were observed, and the number of voids was 0. ×: Voids were observed, and one or more voids were observed.

[0086] (7) Measurement of flexural modulus: Multipurpose test pieces molded in accordance with JIS K7152-1 using a Toshiba Machine EC100 injection molding machine were machined to the specified dimensions, and then measured at 23°C in accordance with JIS K7171. The evaluation was carried out as follows: 〇: Flexural modulus is 1300 MPa or more ×: Flexural modulus less than 1300 MPa

[0087] (8) Haze measurement: Measurement was carried out in accordance with JIS K7136 using a D2 test piece (60 x 60 x 2 mm) molded in accordance with JIS K7152-3 using a Toshiba Machine EC100 injection molding machine. The smaller this value, the higher the transparency, and when this value is 70 to 90%, the translucency that is a feature of the present invention can be achieved.

[0088] (9) Measurement of translucency The two sheets prepared in (8) were stacked on top of each other and placed on top of a printed matter (letters printed in black ink on white paper), with a gap of 3 mm between the printed matter and the two sheets. At this point, the translucency was judged based on whether the letters on the printed matter (3.3 mm long x 3.9 mm wide) could be clearly seen. O: The text is vaguely visible, ensuring the desired translucency. ×: Too transparent to read the text clearly, or too opaque to read the text at all.

[0089] (10) Charpy impact strength measurement Multipurpose test pieces molded in accordance with JIS K7152-1 using a Toshiba Machine EC100 injection molding machine were machined to the specified dimensions, and then measured at 23°C in accordance with JIS K7111. The evaluation was carried out as follows: 〇: Charpy impact strength is 3.0kJ / m 2 End ×: Charpy impact strength is 3.0 kJ / m 2 less than

[0090] (11) Overall rating A comprehensive evaluation was made using the results of the above-mentioned voids, translucency, flexural modulus, and Charpy impact strength. The evaluation was performed as follows. ○: All four ratings are ○. ×: Any of the four evaluations was rated ×, and the product was not suitable for practical use.

[0091] <2. Resins and additives> 〇Propylene polymer (A) (a-1) By using the method using a metallocene catalyst shown in Production Example 1 of JP 2016-186065 A, a propylene-ethylene random copolymer was obtained with an MFR of 30 g / 10 min, an ethylene content of 0.75 wt%, a molecular weight distribution (Mw / Mn) of 2.8, and a T50 of 93°C. Nucleating agent (B) (b-1) 1,3,5-tris[2,2-dimethylpropionylamino]benzene (a compound in which R1 to R3 in formula (1) are all tert-butyl groups.)

[0092] <Examples 1 to 3, Comparative Examples 1 and 2> The above (a-1), (b-1), BASF Japan Ltd.'s product name "Irgaclear XT-386" and antioxidant IRGANOX1010 were blended in a Super Mixer in the proportions shown in Table 1, and then melt-kneaded and pelletized using a Nippon Steel Corporation TEX-25αIII twin-screw extruder at a die extruder outlet temperature of 200°C. The resulting pellets were used for the above evaluations and physical property measurements. The evaluation results are shown in Table 1.

[0093] [Table 1]

Claims

1. A propylene-based resin composition (X) for use in a transport case for an electrical / electronic device component, comprising: a propylene-based polymer (A) satisfying the following requirements (A1) to (A5); and a nucleating agent (B) satisfying the following requirement (B1), and also satisfying the following requirement (X1): Requirement (A1) The propylene polymer (A) is at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers, and is also a metallocene polymer. Requirements (A2) The propylene polymer (A) has a melt flow rate (MFR, 230° C., 2.16 kg load) in the range of 8 to 40 kg / 10 min. Requirements (A3) The propylene polymer (A) has an α-olefin content of 5% by weight or less (provided that the total of propylene and α-olefin in the propylene polymer (A) is 100% by weight). Requirements (A4) The propylene polymer (A) has a molecular weight distribution (weight average molecular weight / number average molecular weight) in the range of 1.5 to 4.

0. Requirements (A5) The propylene polymer (A) has an average elution temperature (T50) of 90 to 105°C and an elution dispersity (σ) of 9°C or less, as measured by temperature rising elution fractionation. Requirement (B1) The nucleating agent (B) has a structure represented by the following formula (1): (In formula (1), R １ , R ２ and R ３ represent, independently of one another, an unsubstituted or substituted hydrocarbon group. Requirements (X1) The propylene-based resin composition (X) contains 0.002 to 0.007 parts by weight of a nucleating agent (B) based on 100 parts by weight of the propylene-based polymer (A).

2. The propylene-based resin composition (X) for a transport case for an electrical and electronic equipment component according to claim 1, further satisfying the following requirement (X2): Requirements (X2) The propylene-based resin composition (X) for a transport case for an electrical and electronic equipment component has a flexural modulus of elasticity of 1,300 MPa or more.

3. A carrying case for electrical and electronic equipment components, comprising the propylene resin composition for carrying cases for electrical and electronic equipment components according to claim 1 or 2.

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