Propylene polymer composition and molded article

Abstract

To provide a propylene-based polymer composition which gives an unbreakable molded article having excellent slipperiness even when the blending amount of a lubricant and an antiblocking agent is reduced.SOLUTION: There is provided a propylene-based polymer composition which comprises a propylene-based polymer (A), a polyethylene (B) and a random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms in a predetermined ratio. The propylene-based polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min, the polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min and a density of 0.920 to 0.965 g / cm3, the random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min and the composition has a melt flow rate of 0.07 to 95 g / 10 min.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a propylene-based polymer composition that provides a molded article with excellent slip properties even when the blending amounts of lubricant and antiblocking agent are reduced. Furthermore, the present invention relates to a propylene-based polymer composition that provides a molded article with excellent slip properties and no cracking even when it contains polyethylene. In the present invention, "crackable" means that the composition breaks into several pieces when a force is applied. Furthermore, "not crackable" means that the composition breaks into several pieces when a force is applied. (1) It does not split into several parts without splitting (cracks). (2) A fissure (crack) forms, but it does not separate into several parts. [Background technology]

[0002] Propylene-based resins are characterized by their excellent rigidity, heat resistance, moldability, transparency, and chemical resistance, and are therefore widely used in a variety of applications, including various industrial materials, automobile-related parts, various medical and cosmetic containers, daily necessities, films, and fibers. Among these, cosmetic containers are required to have properties that allow them to withstand long-term storage of cosmetics and mechanical properties (see, for example, Patent Document 1). Among these, properties that prevent the product from breaking when dropped (impact resistance) are important. Furthermore, cosmetic containers may be fitted with caps and other fastening products, and therefore may require slipperiness (slidability). Slipperiness is also expected to make the surface of the container less susceptible to scratches.

[0003] On the other hand, because cosmetic containers also have an image-important aspect, it is important that they have an appearance that appeals to consumers, particularly a beautiful appearance and a sense of luxury. For example, it is known that cross-linked polystyrene beads or the like are blended into molded products made of synthetic resins such as polypropylene to impart a beautiful matte finish or the like (see, for example, Patent Document 2). It is also known that a lubricant is blended into molded products made of synthetic resins to improve the slipperiness of the container (see, for example, Patent Document 3). However, when printing is performed on the container to impart a sense of luxury, the addition of an anti-blocking agent or lubricant such as cross-linked beads to the container material has the problem of reducing printability. Another problem is that the lubricant bleeds onto the surface of the molded product, impairing the appearance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-182831 [Patent Document 2] Patent application No. 63-297430 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-120798 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above-mentioned circumstances of the prior art, an object of the present invention is to provide a propylene polymer composition which gives molded articles having excellent slip properties and which do not crack even when the blending amounts of lubricant and antiblocking agent are reduced. [Means for solving the problem]

[0006] The present inventors have conducted extensive research and found a specific propylene-based polymer composition that, when used in combination with a lubricant and an antiblocking agent, gives a molded article that is excellent in slipperiness and does not crack, even when the blending amounts of the lubricant and the antiblocking agent are reduced, thereby completing the present invention. That is, the present invention relates to the following propylene polymer composition and molded article thereof.

[0007] [1] A propylene-based polymer composition comprising: a propylene homopolymer (a-1); a block copolymer (a-2) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of ethylene and the α-olefin having 4 or more carbon atoms being less than 30% by weight; and a random copolymer (a-3) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of ethylene and the α-olefin having 4 or more carbon atoms being less than 3% by weight; a polyethylene (B); and a random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of ethylene and the α-olefin having 4 or more carbon atoms being 3 to 17% by weight; the propylene polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min as measured at 230°C under a load of 2.16 kg in accordance with JIS K7210; The polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min, measured at 230°C under a load of 2.16 kg in accordance with JIS K7210, and a density of 0.920 to 0.965 g / cm 3 and the random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The composition contains 15 to 85 parts by weight of a propylene polymer (A) and 85 to 15 parts by weight of a polyethylene (B) for a total of 100 parts by weight, and 5 to 50 parts by weight of a random copolymer (C), The composition is a propylene polymer composition having a melt flow rate of 0.07 to 95 g / 10 min, measured in accordance with JIS K7210 at 230° C. under a load of 2.16 kg. [2] The propylene polymer composition according to [1], wherein a test piece is injection-molded to a thickness of 1 mm at a molding temperature of 200°C and a mold temperature of 40°C, and the test piece is stored at 23°C and 50% RH for 24 hours. After that, the dynamic friction coefficient between two test pieces is measured under the same environment using a 20 mm square flat indenter at a total load of 200 g and a moving speed of 150 mm / min, and the measured value is 0.7 or less. [3] The propylene polymer composition according to [1] or [2], wherein the at least one selected from ethylene and α-olefins having 4 or more carbon atoms is ethylene or 1-butene. [4] The propylene polymer composition according to any one of [1] to [3], wherein the at least one selected from ethylene and α-olefins having 4 or more carbon atoms is ethylene. [5] The propylene polymer composition according to any one of [1] to [4], wherein the composition is substantially free of lubricants and antiblocking agents. [6] A molded article comprising the propylene polymer composition according to any one of [1] to [5]. [7] The molded article according to [6], which is for use as a cosmetic container. [8] The molded product according to [6], which is for automobile-related parts. [Effects of the Invention]

[0008] Molded articles produced using the propylene polymer composition of the present invention are useful because they have excellent slip properties and do not crack even when the blending amounts of lubricant and antiblocking agent are reduced. In particular, injection-molded articles are very useful. [Brief explanation of the drawings]

[0009] [Figure 1] Figure 1 shows the cracking test in the MD and TD directions, which is carried out by making cuts in an injection test piece measuring 120 mm x 120 mm x 2 mm. [Figure 2] FIG. 2 is a diagram showing the elution amount and the integrated elution amount in temperature-rising elution fractionation (TREF) measurement of the propylene-ethylene random block copolymer (c) used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] The propylene polymer composition of the present invention contains a propylene polymer (A) selected from the group consisting of a propylene homopolymer (a-1); a block copolymer (a-2) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 30% by weight; and a random copolymer (a-3) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 3% by weight; a polyethylene (B); and a random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is 3 to 17% by weight. The propylene polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min, measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; and the polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min, measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg, and a density of 0.920 to 0.965 g / cm. 3 The random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min as measured at 230°C under a load of 2.16 kg in accordance with JIS K7210. The composition contains 100 parts by weight in total of 15 to 85 parts by weight of the propylene polymer (A) and 85 to 15 parts by weight of the polyethylene (B), and 5 to 50 parts by weight of the random copolymer (C); the melt flow rate of the composition is 0.07 to 95 g / 10 min as measured at 230°C under a load of 2.16 kg in accordance with JIS K7210. The propylene polymer composition can provide molded articles that are excellent in slipperiness and do not crack even when the blending amounts of lubricant and antiblocking agent are reduced. Furthermore, the propylene polymer composition can provide molded articles that are excellent in slipperiness and do not crack even when the propylene polymer composition contains polyethylene (B).

[0011] <Propylene polymer (A)> The propylene polymer (A) is selected from the group consisting of a propylene homopolymer (a-1); a block copolymer (a-2) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 30% by weight (hereinafter also referred to as block copolymer (a-2)); and a random copolymer (a-3) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 3% by weight (hereinafter also referred to as random copolymer (a-3)). The propylene polymer composition containing the propylene polymer (A) can have increased rigidity and impact resistance. The propylene polymer (A) is preferably a propylene homopolymer (a-1) from the viewpoint of rigidity of the molded article, a block copolymer (a-2) from the viewpoint of impact resistance against cracking due to dropping the product, etc., and a random copolymer (a-3) from the viewpoint of transparency related to color development. The propylene polymer (A) may be any one of (a-1) to (a-3) or a mixture of two or more of these.

[0012] The block copolymer (a-2) generally has an island-in-a-sea structure. The island-in-a-sea structure can be confirmed by electron microscope observation. When the block copolymer (a-2) is a multi-stage polymer, if the content of at least one selected from ethylene and an α-olefin having 4 or more carbon atoms in the second polymerization stage reaches a certain proportion, for example, around 20% by weight, the block copolymer forms an island-in-a-sea structure, and transparency tends to be extremely poor. On the other hand, the random copolymer (a-3) does not form a sea-island structure and therefore has excellent transparency.

[0013] [Propylene homopolymer (a-1)] From the viewpoint of the rigidity of the obtained molded article, the propylene polymer (A) is preferably a propylene homopolymer (a-1). In the propylene homopolymer (a-1), the isotactic pentad fraction, which is an index of stereoregularity, is preferably 0.90 or more, more preferably 0.94 to 0.98. When the isotactic pentad fraction is 0.90 or more, the rigidity of the molded article is improved. Here, the isotactic pentad fraction is 13 This is a value measured by a proton decoupling method using C-NMR. The propylene homopolymer (a-1) may be used alone or in combination of two or more kinds.

[0014] [Block copolymer (a-2)] The block copolymer (a-2) is a copolymer of propylene and at least one selected from ethylene and α-olefins having 4 or more carbon atoms, and the polymerized portion of propylene constitutes a block. When the propylene-based polymer composition contains the block copolymer (a-2), the impact resistance of the molded article can be improved and cracking can be suppressed. Examples of the α-olefin having 4 or more carbon atoms include α-olefins having 4 to 20 carbon atoms, such as 1-butene, 1-hexene, and 1-octene. The at least one selected from ethylene and α-olefins having 4 or more carbon atoms to be copolymerized with propylene may be one type or two or more types. Of these, ethylene and 1-butene are preferred, and ethylene is more preferred. The block copolymer (a-2) may be used alone or in combination of two or more types.

[0015] Specific examples of the block copolymer (a-2) include binary or ternary copolymers in which propylene is arbitrarily combined with a comonomer, such as a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-1-octene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, a propylene-1-butene-1-octene copolymer, etc. Among these, a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer are preferred, and a propylene-ethylene copolymer is more preferred.

[0016] From the viewpoint of rigidity of the molded article, the content of ethylene and α-olefins having 4 or more carbon atoms in the block copolymer (a-2) is less than 30% by weight, preferably 3 to 25% by weight, and more preferably 5 to 20% by weight.

[0017] The block copolymer (a-2) can be a multi-stage polymer. For example, in the case of a two-stage polymer, from the viewpoint of the balance between rigidity and impact resistance of the resulting molded article, the first stage is preferably a polypropylene homopolymer or a random copolymer of propylene and at least one selected from ethylene and α-olefins having 4 or more carbon atoms, the content of ethylene and the α-olefin having 4 or more carbon atoms being 2% by weight or less; and the second stage is preferably a random copolymer of propylene and at least one selected from ethylene and α-olefins having 4 or more carbon atoms, the content of ethylene and the α-olefin having 4 or more carbon atoms being 20 to 80% by weight, preferably 30 to 70% by weight. As the ethylene and the α-olefin having 4 or more carbon atoms constituting the random copolymer, ethylene and 1-butene are preferred, and ethylene is more preferred. For the same reason, the ethylene content in the second and subsequent stages of the block copolymer (a-2), which is a multistage polymer produced by polymerization in multiple stages, is preferably 20% by weight or more.

[0018] [Random copolymer (a-3)] The random copolymer (a-3) is a copolymer of propylene and at least one selected from ethylene and α-olefins having 4 or more carbon atoms, and the content of ethylene and α-olefins having 4 or more carbon atoms is less than 3% by weight. When the propylene polymer composition contains the random copolymer (a-3), the transparency of the molded article, that is, the color development property when colored, can be improved. Examples of the α-olefin having 4 or more carbon atoms include α-olefins having 4 to 20 carbon atoms, such as 1-butene, 1-hexene, and 1-octene. The at least one selected from ethylene and α-olefins having 4 or more carbon atoms to be copolymerized with propylene may be one type or two or more types. Of these, ethylene and 1-butene are preferred, and ethylene is more preferred. The random copolymer (a-3) may be used alone or in combination of two or more types.

[0019] Specific examples of the random copolymer (a-3) include binary or ternary copolymers obtained by arbitrarily combining propylene with a comonomer, such as propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-1-butene-1-octene copolymer, etc. Among these, propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene-1-butene copolymer are preferred, and propylene-ethylene copolymer is more preferred.

[0020] From the viewpoint of transparency, the content of ethylene and α-olefins having 4 or more carbon atoms in the random copolymer (a-3) is less than 3% by weight, preferably 0.5 to 2.5% by weight, and more preferably 1.0 to 2.0% by weight.

[0021] The random copolymer (a-3) can be a multi-stage polymer. For example, in the case of a two-stage polymer, from the viewpoint of rigidity, the first stage is preferably a polypropylene homopolymer or a random copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of ethylene and at least one selected from α-olefins having 4 or more carbon atoms being 3% by weight or less; and the second stage is preferably a random copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of ethylene and at least one selected from α-olefins having 4 or more carbon atoms being 20% ​​by weight or less. As the ethylene and the α-olefin having 4 or more carbon atoms constituting the random copolymer, ethyne and 1-butene are preferred, and ethylene is more preferred.

[0022] <<Properties of Propylene Polymer (A)>> The propylene polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min, preferably 5 to 60 g / 10 min, and more preferably 10 to 40 g / 10 min, measured at 230°C under a load of 2.16 kg in accordance with JIS K 7210. A melt flow rate of 0.5 g / 10 min or more improves molding processability and allows a molded article to achieve satisfactory performance, while a melt flow rate of 100 g / 10 min or less improves the mechanical strength of the molded article. The melt flow rate (MFR) of the propylene polymer (A) can be easily adjusted by adjusting the polymerization conditions such as temperature and pressure, or by controlling the amount of hydrogen added in a method in which a chain transfer agent such as hydrogen is added during polymerization.

[0023] In the propylene polymer (A), the contents of propylene, ethylene, and α-olefins having 4 or more carbon atoms satisfy the following conditions: 13 It can be measured by C-NMR. Equipment: JEOL-GSX270 manufactured by JEOL Ltd. Concentration: 300mg / 2mL Solvent: orthodichlorobenzene In the case of a propylene-ethylene copolymer, the contents of propylene and ethylene are as follows, as described in the examples: 13 Measurements can be made by infrared spectroscopy based on a calibration curve prepared by infrared spectroscopy using a reference material whose composition has been verified by C-NMR.

[0024] <<Catalyst for Propylene Polymer (A)>> The catalyst used in the synthesis of the propylene polymer (A) is not particularly limited, but it is preferable to use a stereoregular catalyst, such as a Ziegler catalyst or a metallocene catalyst.

[0025] Examples of Ziegler catalysts include two-component catalysts composed of a transition metal component, such as a titanium halide compound such as titanium trichloride, titanium tetrachloride, or trichloroethoxytitanium, or a contact product of the titanium halide compound with a magnesium compound, typically a magnesium halide; and an organometallic component, such as an alkylaluminum compound or its halide, hydride, or alkoxide; and three-component catalysts in which an electron-donating compound containing nitrogen, carbon, phosphorus, sulfur, oxygen, silicon, or the like is added to any of the above components.

[0026] The metallocene catalyst is preferably a supported type. A particularly preferred example of the supported metallocene catalyst is a metallocene catalyst in which the support is an ion-exchanged layered silicate that also functions as a co-catalyst. Specifically, such a metallocene catalyst can be obtained by combining the following components [A], [B], and, if necessary, the following component [C].

[0027] 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

[0028] Component [A]: Metallocene complex Specifically, the compound represented by the following formula [I] can be used as the component [A]: Component [A] may be used alone or in combination of two or more types. Q(C5H 4-a R 1 a )(C5H 4-b R 2 b )MXY ···[I] In 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, halogen, 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.

[0029] R 1 and R 2 each independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen, 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- or 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.

[0030] 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

[0031] (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

[0032] (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.

[0033] 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): (A) 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, lisardite, and antigorite (a) Smectite group such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, etc., vermiculite group such as vermiculite, mica group such as mica, illite, sericite, glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group, which have a 2:1 type structure as their main constituent layer.

[0034] The silicate used in the present invention may be a layered silicate in which the mixed layers of (a) and (b) above are formed. In the present invention, the main component silicate is preferably a silicate having a 2:1 type structure, more preferably a smectite, and particularly preferably montmorillonite. The main component means the component that is present in the largest amount. Component [B] may be used alone or in combination of two or more types.

[0035] The activity of these silicates can be improved by chemically treating them with an acid, salt, alkali, oxidizing agent, reducing agent, 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 inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, with sulfuric acid being 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.

[0036] 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, and 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.

[0037] 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.

[0038] 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 formula [II]: (AlR 4 p X 3-p ) q [II] In formula [II], R 4represents 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, q=1, and X=hydrogen. More preferred are R 4 is a trialkylaluminum having 1 to 8 carbon atoms.

[0039] The organoaluminum compounds can be used alone or in combination. The organoaluminum compounds can be added not only during catalyst preparation but also during prepolymerization or main polymerization.

[0040] <<Method for producing propylene polymer (A)>> Examples of methods for producing the propylene polymer (A) include a slurry polymerization method using an inert solvent in the presence of the catalyst, a solution polymerization method, a gas phase polymerization method using substantially no solvent, and a bulk polymerization method using a polymerizable monomer as a solvent. For example, in the case of a slurry polymerization method, the polymerization can be carried out in an inert hydrocarbon or liquid monomer such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, or xylene. The polymerization temperature is usually from -80 to 150°C, and preferably from 40 to 120°C. The polymerization pressure is preferably from 1 to 60 atmospheres (0.10 to 6.08 MPa), and the molecular weight of the resulting propylene polymer (A) can be adjusted with hydrogen or other known molecular weight adjusters. The polymerization is carried out by a continuous or batch reaction, and the conditions may be those usually used. The polymerization reaction may be carried out in one stage or in multiple stages. When a metallocene catalyst is used, it is desirable to carry out 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]).

[0041] 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.

[0042] 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 gram 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.

[0043] In the present invention, after the polymerization is completed, the resulting propylene polymer (A) 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. As such a propylene-based polymer (A), commercially available products can be used, for example, NOVATEC PP, a trade name manufactured by Japan Polypropylene Corporation.

[0044] <Polyethylene (B)> The raw material monomer for polyethylene (B) may be petroleum-derived ethylene or plant-derived ethylene. Plant-derived ethylene can be obtained by fermenting plant materials such as sugarcane with microorganisms to produce ethanol, which is then heated in the presence of a catalyst to cause an intramolecular dehydration reaction. In the case of plant-derived polyethylene, it is a polymer obtained by polymerizing a monomer containing plant-derived ethylene as the main component. In the case of plant-derived polyethylene, the raw material monomer of polyethylene (B) does not need to contain 100% plant-derived ethylene. Using plant-derived ethylene as part of the monomer can also reduce the environmental impact. The polyethylene (B) contains 80 to 100 mol %, preferably 85 to 100 mol %, of ethylene units. Examples of plant-derived polyethylene that can be used include homopolymers obtained by homopolymerizing plant-derived ethylene and copolymers obtained by copolymerizing plant-derived ethylene with an α-olefin. The number of carbon atoms in the α-olefin is not particularly limited, but 1-butene, 1-hexene, or 1-octene is preferred. Furthermore, petroleum-derived ethylene may be contained.

[0045] The density of polyethylene (B) is 0.920 to 0.965 g / cm 3 When the density is within this range, the lubricity and sliding properties of the molded product are improved. 3 If the density is less than 0.930 to 0.965 g / cm3, improvement in slipperiness and sliding properties cannot be expected. 3 It is preferable that the density is 0.940 to 0.965 g / cm 3 It is more preferable that:

[0046] The polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min, measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg. A melt flow rate of 0.05 g / 10 min or more improves moldability, while a melt flow rate of 80 g / 10 min or less improves the impact resistance of molded articles. The melt flow rate is preferably 1 to 60 g / 10 min, and more preferably 5 to 50 g / 10 min.

[0047] Commercially available polyethylene (B) includes, for example, "Novatec" (trade name, manufactured by Japan Polyethylene Co., Ltd.) as a petroleum-derived polyethylene, and the "Green PE" series (trade name, manufactured by Braskem) as a plant-derived polyethylene.

[0048] <Random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is 3 to 17% by weight> (hereinafter also referred to as random copolymer (C)) The random copolymer (C) is a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, and the content of ethylene and the α-olefin having 4 or more carbon atoms is 3 to 17% by weight. The propylene polymer (A) and polyethylene (B) constituting the propylene polymer composition have poor compatibility with each other, which may lead to problems such as poor impact resistance and cracking in molded articles formed using a composition consisting of these two components. After extensive studies, the present inventors have found that by blending a predetermined amount of the random copolymer (C) into the propylene polymer composition, the compatibility between the propylene polymer (A) and the polyethylene (B) is improved, and the impact resistance of a molded article obtained from the composition can be improved and cracking can be suppressed while maintaining the rigidity. Examples of the α-olefin having 4 or more carbon atoms include α-olefins having 4 to 20 carbon atoms, such as 1-butene, 1-hexene, and 1-octene. The at least one selected from ethylene and α-olefins having 4 or more carbon atoms to be copolymerized with propylene may be one type or two or more types. Of these, ethylene and 1-butene are preferred, and ethylene is more preferred. The random copolymer (C) may be used alone or in combination of two or more types.

[0049] Specific examples of the random copolymer (C) include binary or ternary copolymers in which propylene is arbitrarily combined with a comonomer, such as a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-1-octene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, a propylene-1-butene-1-octene copolymer, etc. Among these, a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer are preferred, and a propylene-ethylene copolymer is more preferred.

[0050] In the random copolymer (C), the content of ethylene and α-olefins having 4 or more carbon atoms is 3 to 17% by weight, preferably 4 to 15% by weight, and more preferably 5 to 12% by weight. By setting the content of ethylene and α-olefins having 4 or more carbon atoms to 3% by weight or more, the impact resistance of the molded article becomes sufficient, and by setting it to 17% by weight or less, the molded article can maintain high rigidity and have good demoldability during injection molding.

[0051] The catalyst used in synthesizing the random copolymer (C) is not particularly limited, but it is preferable to use a stereoregular catalyst. Examples of the stereoregular catalyst include Ziegler catalysts and metallocene catalysts. As the Ziegler catalyst and metallocene catalyst, those exemplified as catalysts for the propylene polymer (A) can be used. Among them, it is preferable to use a metallocene catalyst from the viewpoint of suppressing cracking of the molded article due to the incorporation of polyethylene (B).

[0052] The random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min, preferably 2 to 50 g / 10 min, and more preferably 5 to 30 g / 10 min, measured at 230°C under a load of 2.16 kg in accordance with JIS K 7210. A melt flow rate of 0.5 g / 10 min or more improves molding processability, while a melt flow rate of 80 g / 10 min or less prevents relatively low molecular weight components in the random copolymer (C) from bleeding onto the surface of a molded article, resulting in a good appearance. The melt flow rate (MFR) of the random copolymer (C) can be easily adjusted by adjusting the polymerization conditions such as temperature and pressure, or by controlling the amount of hydrogen added in a method in which a chain transfer agent such as hydrogen is added during polymerization.

[0053] From the viewpoint of the balance between rigidity and impact resistance of the obtained molded article, the random copolymer (C) is preferably a multistage polymer consisting of a random copolymer (c-1) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of which is 1 to 5 wt%, and a random copolymer (c-2) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of which is 7 wt% to less than 25 wt%, and a random block copolymer containing (c-1) as a block component. In this case, the random copolymer (C) is preferably a metallocene-based propylene-(ethylene and / or an α-olefin having 4 or more carbon atoms) random block copolymer (c). Examples of α-olefins having 4 or more carbon atoms include α-olefins having 4 to 20 carbon atoms, such as 1-butene, 1-hexene, and 1-octene. The at least one selected from ethylene and α-olefins having 4 or more carbon atoms may be one type or two or more types. Of these, ethylene and 1-butene are preferred, and ethylene is more preferred. (c-1) and (c-2) may each be used alone or in combination of two or more types.

[0054] The content of ethylene and an α-olefin having 4 or more carbon atoms in (c-1) is preferably 1 to 5 wt%, more preferably 1.5 to 4.0 wt%, and even more preferably 1.5 to 3.0 wt%. When the content of ethylene and an α-olefin having 4 or more carbon atoms in (c-1) is 1 wt% or more, the compatibility of the propylene polymer (A), the polyethylene (B), and the random copolymer (C) tends to be sufficient, and when it is 5 wt% or less, the rigidity of the molded article tends to be sufficient.

[0055] The content of ethylene and α-olefin having 4 or more carbon atoms in (c-2) is preferably 7% by weight or more and less than 25% by weight, more preferably 7 to 20% by weight, and even more preferably 8 to 15% by weight. When the content of ethylene and α-olefin having 4 or more carbon atoms in (c-2) is 7% by weight or more, the compatibility of the propylene polymer (A), polyethylene (B), and random copolymer (C) tends to be sufficient, and when it is less than 25% by weight, the rigidity of the molded article tends to be sufficient.

[0056] Specific examples of the random copolymers (c-1) and (c-2) include binary or ternary copolymers in which propylene is arbitrarily combined with a comonomer, such as a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-1-octene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, a propylene-1-butene-1-octene copolymer, etc. Among these, a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer are preferred, and a propylene-ethylene copolymer is more preferred.

[0057] For the same reason, in the random copolymer (C), which is a multistage polymer produced by polymerization in multiple stages, the ethylene content in the second and subsequent stages is preferably less than 20% by weight.

[0058] When the random copolymer (C) is a multistage polymer composed of (c-1) and (c-2), the random copolymer (C) preferably satisfies the following condition (Ci). (Ci) The proportions of (c-1) and (c-2) are 30 to 70 parts by weight of (c-1) and 30 to 70 parts by weight of (c-2), totaling 100 parts by weight. The proportions of (c-1) and (c-2) are preferably 30 to 70 parts by weight of (c-1) and 30 to 70 parts by weight of (c-2), for a total of 100 parts by weight; more preferably 30 to 60 parts by weight of (c-1) and 40 to 70 parts by weight of (c-2); and even more preferably 40 to 60 parts by weight of (c-1) and 40 to 60 parts by weight of (c-2). When (c-1) is 30 parts by weight or more, the rigidity of the molded article tends to be improved, and when (c-1) is 70 parts by weight or less, the compatibility of the propylene polymer (A), polyethylene (B), and random copolymer (C) tends to be good.

[0059] The melt flow rates of (c-1) and (c-2), measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg, are preferably in the range of 0.5 to 80 g / 10 min. When the melt flow rates of (c-1) and (c-2) are 0.5 g / 10 min or higher, moldability is improved, and when they are 80 g / 10 min or lower, the relatively low molecular weight components in (c-1) and (c-2) are less likely to bleed onto the surface of the molded article, resulting in a good appearance. The melt flow rates of (c-1) and (c-2) are preferably 2 to 50 g / 10 min, and more preferably 5 to 30 g / 10 min.

[0060] The melt flow rate (MFR) of (c-2) can be calculated using the following formula from the melt flow rates (MFR) of the random block copolymers (c) and (c-1) and the content ratios of (c-1) and (c-2) in the random block copolymer (c). Log e [MFR of random block copolymer (c)] = [content of (c-1)] × Log e [MFR of (c-1)] + [content ratio of (c-2)] × Log e [MFR of (c-2)]

[0061] The melt flow rates (MFR) of (c-1) and (c-2) can be easily adjusted by adjusting the temperature and pressure, which are polymerization conditions, or by controlling the amount of hydrogen added in a method in which a chain transfer agent such as hydrogen is added during polymerization.

[0062] The melting peak temperature (Tm) of the random copolymer (C) is preferably in the range of 125 to 145° C., more preferably 128 to 141° C., and even more preferably 130 to 140° C. When the melting peak temperature (Tm) is 125° C. or higher, the moldability and rigidity of the molded article tend to be good, and when it is 145° C. or lower, the impact resistance tends to be good.

[0063] The melting peak temperature (Tm) is measured using a differential scanning calorimeter (DSC). A sample of 5.0 mg is heated to 200°C, and after erasing the thermal history, the sample is held at 200°C for 5 minutes. The temperature is then lowered to 40°C at a rate of 10°C / min to crystallize the sample. The peak position of the curve drawn when the sample is melted at a heating rate of 10°C / min is taken as the melting peak temperature Tm (°C).

[0064] In the random copolymer (C) (including the random block copolymer (c)) and (c-1), the contents of propylene, ethylene, and α-olefins having 4 or more carbon atoms are as follows: 13 It can be measured by C-NMR. Equipment: JEOL-GSX270 manufactured by JEOL Ltd. Concentration: 300mg / 2mL Solvent: orthodichlorobenzene In the case of a propylene-ethylene copolymer, the contents of propylene and ethylene are as follows, as described in the examples: 13 Measurements can be made by infrared spectroscopy based on a calibration curve prepared by infrared spectroscopy using a reference material whose composition has been verified by C-NMR.

[0065] The contents of ethylene and α-olefins having 4 or more carbon atoms in the random copolymer (c-2) can be calculated from the contents of ethylene and α-olefins having 4 or more carbon atoms in the random block copolymers (c) and (c-1) determined as described above, and the contents of (c-1) and (c-2) in the random block copolymer (c).

[0066] [Calculation of the content of (c-1) and (c-2)] When the random copolymer (C) is a multistage polymer consisting of (c-1) and (c-2), the contents of (c-1) and (c-2) can be determined by material balance during production, but to determine them more accurately, they can be calculated using temperature-rising elution fractionation (TREF).

[0067] Hereinafter, a method for evaluating a propylene-ethylene random copolymer will be described, but a random copolymer of propylene and an α-olefin having 4 or more carbon atoms can also be evaluated in the same manner. The method for evaluating the crystallinity distribution of a propylene-ethylene random copolymer by TREF is well known to those skilled in the art, and detailed measurement methods are described in, for example, the following documents. G.Glockner,J.Appl.Polym.Sci.:Appl.Polym.Symp.;45,1-24(1990) L.Wild,Adv.Polym.Sci.;98,1-47(1990) JBPSoares, AE Hamielec, Polymer;36,8,1639-1654(1995)

[0068] In the propylene-ethylene random block copolymer (c), there is a large difference in crystallinity between the propylene-ethylene random copolymers (c-1) and (c-2). In addition, since the crystallinity distribution of each copolymer is narrow due to the use of a metallocene catalyst in production, there are very few intermediate components between the two copolymers, and it is possible to accurately distinguish between the two copolymers using TREF.

[0069] A specific method will be described with reference to Figure 2. Figure 2 shows the elution amount and integrated elution amount in the TREF measurement of the propylene-ethylene random block copolymer (c) used in the examples. In the TREF elution curve (plot of elution amount against temperature), the propylene-ethylene random copolymers (c-1) and (c-2) show elution peaks at T(β) and T(α), respectively, due to differences in crystallinity, and the difference is sufficiently large that they can be almost completely separated at the intermediate temperature T(C) (={T(α)+T(β)} / 2).

[0070] The lower limit of the TREF measurement temperature is -15°C with the apparatus used in this measurement, but if the crystallinity of component (α) is very low or it is an amorphous component, this measurement method may not show a peak within the measurement temperature range. (In this case, the concentration of component (α) dissolved in the solvent at the lower limit of the measurement temperature (i.e., -15°C) is detected.) In this case, T(α) is considered to exist below the lower limit of the measurement temperature, but since its value cannot be measured, in such cases T(α) is defined as −15°C, the lower limit of the measurement temperature. Here, if the cumulative amount of components eluted up to T(C) is defined as W(α) wt%, and the cumulative amount of components eluted above T(C) is defined as W(β) wt%, W(α) corresponds roughly to the amount of the low-crystalline or amorphous component (α), i.e., (c-2), and W(β) corresponds roughly to the amount of the relatively highly crystalline component (β), i.e., (c-1). The method for calculating the elution amount curve obtained by TREF and the various temperatures and amounts described above obtained therefrom is shown in Figure 2.

[0071] <<Method for producing random copolymer (C)>> The method for producing the random copolymer (C) is not particularly limited, and for example, the methods exemplified in the method for producing the propylene polymer (A) can be used. Among them, a method using a metallocene catalyst is preferred from the viewpoint of suppressing cracking of the molded article due to the incorporation of polyethylene (B). As the metallocene catalyst, those exemplified as catalysts for the propylene polymer (A) can be used. When the random copolymer (C) is a multistage polymer, it is preferably a multistage polymer consisting of the above (c-1) and (c-2). As the random copolymer (C), commercially available products can be used, such as those manufactured by Exxon Mobil Corporation under the trade name Vistamax, and those manufactured by Japan Polypropylene Corporation under the trade names WELNEX, WINTEC, and NOVATEC PP.

[0072] <Propylene-Based Polymer Composition> The propylene polymer composition contains 15 to 85 parts by weight of the propylene polymer (A) and 85 to 15 parts by weight of the polyethylene (B), totaling 100 parts by weight, and 5 to 50 parts by weight of the random copolymer (C). By keeping the propylene polymer (A), polyethylene (B), and random copolymer (C) within the above ranges, it is possible to provide a propylene polymer composition that gives molded articles that are excellent in slip properties and do not crack, even when the blending amounts of the lubricant and antiblocking agent are reduced.

[0073] The propylene polymer composition contains 15 to 85 parts by weight of the propylene polymer (A) and 85 to 15 parts by weight of the polyethylene (B) for a total of 100 parts by weight, preferably 30 to 70 parts by weight of the propylene polymer (A) and 70 to 30 parts by weight of the polyethylene (B) for a total of 100 parts by weight, and more preferably 35 to 65 parts by weight of the propylene polymer (A) and 65 to 35 parts by weight of the polyethylene (B) for a total of 100 parts by weight. When the content ratios of the propylene polymer (A) and the polyethylene (B) are within the above ranges, the slipperiness and slidability of the molded article can be improved.

[0074] In the propylene polymer composition, the content of the random copolymer (C) relative to 100 parts by weight of the total of the propylene polymer (A) and the polyethylene (B) is 5 parts by weight or more and 50 parts by weight or less, preferably 10 to 40 parts by weight, and more preferably 10 to 30 parts by weight. When the content of the random copolymer (C) is 5 parts by weight or more, the impact resistance is improved, and when it is 50 parts by weight or less, the rigidity is improved.

[0075] The propylene polymer composition has a melt flow rate of 0.07 to 95 g / 10 min, preferably 1 to 75 g / 10 min, and more preferably 5 to 50 g / 10 min, measured at 230°C under a load of 2.16 kg in accordance with JIS K 7210. A melt flow rate of 0.07 g / 10 min or more improves moldability, and a melt flow rate of 95 g / 10 min or less improves impact resistance.

[0076] <Additives> In addition to the above-mentioned components, the propylene polymer composition may contain additives such as various antioxidants used as stabilizers for propylene polymers, ultraviolet absorbers, light stabilizers, neutralizing agents, and nucleating agents.

[0077] Examples of antioxidants include phosphorus-based antioxidants such as bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, distearylpentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite, and tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4'-biphenylene diphosphonite; 2,6-di-t-butyl-p-cresol; and tetrakis[methylphenyl]-4,4'-biphenylene diphosphonite. Examples of antioxidants include phenolic antioxidants such as tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxylphenyl)propionate]methane, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate; and thio antioxidants such as di-stearyl-β,β'-thio-di-propionate, di-myristyl-β,β'-thio-di-propionate, and di-lauryl-β,β'-thio-di-propionate.

[0078] Examples of the ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole.

[0079] Light stabilizers include n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,4-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate-2-(4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl)ethanol condensate, poly{[6-[(1,1,3,3-tetramethylbutyl)acetate] and light stabilizers such as N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate.

[0080] Further examples include amine-based antioxidants represented by the following formula (1) and formula (2), which have good resistance to NOx gas discoloration, lactone-based antioxidants such as 5,7-di-t-butyl-3-(3,4-dimethyl-phenyl)-3H-benzofuran-2-one, and vitamin E-based antioxidants such as those represented by the following formula (3). [ka] [ka] [ka]

[0081] Examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate; hydrotalcite; for example, a magnesium aluminum complex hydroxide salt represented by the following formula (4) under the trade name DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.); and a lithium aluminum complex hydroxide salt represented by the following formula (5) under the trade name Mizukalac (registered trademark) (manufactured by Mizusawa Industrial Chemicals Co., Ltd.). Mg 1-x Al x (OH)2(CO3) x / 2 ·mH2O …(4) [Where x is 0 <x ≦ 0.5 and m is a positive integer of 3 or less.] [Al2Li(OH)6] n X·mH2O …(5) [Where X is an inorganic or organic anion, n is the valence of the anion (X), and m is a positive integer of 3 or less.] Among them, from the viewpoints of neutralization performance and economy, metal salts of stearic acid are preferred, and calcium stearate is particularly preferred. The content of the metal salt of stearic acid with respect to 100 parts by weight in total of the propylene-based polymer (A) and polyethylene (B) is preferably 0.01 to 0.1 part by weight, more preferably 0.02 to 0.08 part by weight, and still more preferably 0.03 to 0.06 part by weight.

[0082] Examples of the nucleating agent include sterically hindered amide compounds, metal salts of organic dicarboxylic acids, metal salts of organic monocarboxylic acids, aromatic carboxylic acid-based compounds or their derivatives, sorbitol-based compounds or their derivatives, nonitol-based compounds or their derivatives, metal salts of diterpenic acids, polymer nucleating agents, and the like.

[0083] Even if the blending amounts of the lubricant and the antiblocking agent are reduced, the propylene-based polymer composition can provide a molded product having excellent slipperiness and not cracking. From the viewpoints of printing suitability and suppression of bleeding onto the surface of the molded product, it is preferable that the propylene-based polymer composition does not substantially contain a lubricant and an antiblocking agent. In the present invention, "not substantially containing" means not intentionally containing, except for the case where it is unavoidably mixed in by industrial raw materials. Specifically, it means that the content ratios of the lubricant and the antiblocking agent in 100% by weight of the propylene-based polymer composition are each less than 0.1% by weight, preferably less than 0.05% by weight, more preferably less than 0.01% by weight, and particularly preferably less than 0.001% by weight.

[0084] Examples of the lubricant include monoamides, substituted amides, and bisamides. Specific examples of monoamides include saturated fatty acid monoamides such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Examples of the unsaturated fatty acid monoamide include oleic acid amide, erucic acid amide, and ricinoleic acid amide. Specific examples of the substituted amides include N-stearyl stearamide, N-oleyl oleamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, and N-oleyl palmitamide. Specific examples of bisamides include saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisisostearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene bishydroxystearic acid amide, N,N'-distearyl adipic acid amide, and N,N'-distearyl sebacate amide. Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, and N,N'-dioleyl sepacic acid amide. Examples of aromatic bisamides include m-xylylene bisstearic acid amide and N,N'-distearyl isophthalic acid amide. In this specification, the lubricant does not include the compounds exemplified as the neutralizing agent.

[0085] Examples of anti-blocking agents include inorganic pigments such as synthetic or natural silica (silicon dioxide), magnesium silicate, aluminosilicate, zeolite, aluminum borate, calcium sulfate, and calcium phosphate. In addition, organic pigments include polymethyl methacrylate, polymethylsilyl sesquioxane (silicone), polyamide, polytetrafluoroethylene, epoxy resin, polyester resin, benzoguanamine-formaldehyde (urea resin), phenolic resin, polystyrene resin, and acrylic resin.

[0086] Furthermore, the propylene polymer composition may contain various known additives, such as antistatic agents, dispersants, dyes, pigments other than antiblocking agents, etc., within the range that does not impair the object of the present invention.

[0087] The propylene polymer composition may contain other polymers besides the propylene polymer (A), polyethylene (B), and random copolymer (C), such as mono-, bi-, and terpolymers, such as polyethylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and acrylate polymer, as long as the properties and functions of the propylene polymer composition are not impaired. The content of the other polymers may be, for example, 1 to 30 parts by weight per 100 parts by weight of the propylene polymer composition. Similarly, elastomers such as natural rubber, butyl rubber, diene rubber, EPR, and EPDM may also be blended. Furthermore, general-purpose inorganic fillers such as talc, calcium carbonate, and barium sulfate may be used in combination as fillers in an amount of 1% by weight or more.

[0088] <<Method for producing propylene polymer composition>> The propylene polymer composition can be obtained by mixing predetermined amounts of the propylene polymer (A), the polyethylene (B), the random copolymer (C), and, if necessary, other additives in a Henschel mixer (trade name), a super mixer, a ribbon blender, or the like, and then melt-kneading the mixture in a temperature range of 190 to 260°C using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a plavender, a roll, or the like.

[0089] <<Molded Articles Containing Propylene-Based Polymer Compositions>> A molded article containing the propylene polymer composition can be obtained by molding the propylene polymer composition into a desired shape by a molding method such as injection molding, extrusion molding, blow molding, vacuum molding, or compression molding.

[0090] A propylene polymer composition is injection-molded to a thickness of 1 mm at a molding temperature of 200°C and a mold temperature of 40°C. After storing the specimen at 23°C and 50% RH for 24 hours, the dynamic friction coefficient between two specimens measured under the same conditions using a 20 mm square flat indenter at a total load of 200 g and a movement speed of 150 mm / min is preferably 0.7 or less. A dynamic friction coefficient of 0.7 or less ensures good sliding properties of the molded article. The dynamic friction coefficient is more preferably 0.65 or less, and even more preferably 0.60 or less.

[0091] The flexural modulus of the propylene polymer composition measured in accordance with JIS K7171 is preferably in the range of 700 to 2400 MPa. A flexural modulus of 700 MPa or more improves mold releasability from a mold during injection molding, while a flexural modulus of 2400 MPa or less improves the impact resistance of molded articles. The flexural modulus is more preferably 750 to 1800 MPa, and even more preferably 750 to 1600 MPa.

[0092] The Charpy impact strength of the propylene polymer composition measured in accordance with JIS K7111 is preferably 3.0 kJ / m 2 The Charpy impact strength is 3.0 kJ / m or more. 2If the Charpy impact strength is 3.5 kJ / m or more, breakage of the molded article during transportation is suppressed. 2 or more, and more preferably 4.0 kJ / m 2 That's all.

[0093] A molded article containing the propylene-based polymer composition has excellent characteristics, such as excellent slip resistance and resistance to cracking, even when the blending amounts of lubricant and antiblocking agent are reduced. The uses of the molded article are not particularly limited, and the molded article can be used in a wide variety of applications, such as various industrial materials, automobile-related parts, various containers for medical and cosmetic use, daily necessities, films, and fibers. In particular, the molded article containing the propylene-based polymer composition can be suitably used for cosmetic containers and automobile-related parts. [Example]

[0094] EXAMPLES The present invention will be described in detail below with reference to examples, comparative examples and reference examples, but the present invention is not limited to these examples. In the following examples, comparative examples, and reference examples, the physical properties of the propylene polymer (A), polyethylene (B), propylene-ethylene random copolymer (C), and propylene polymer composition were measured according to the following methods.

[0095] <1. Measurement method> (1) Melt flow rate (MFR): For resins other than the propylene-ethylene random copolymer (c-2), the measurement was carried out in accordance with JIS K7210 at 230°C and under a load of 2.16 kg.

[0096] The melt flow rate (MFR) of the propylene-ethylene random copolymer (c-2) was calculated using the following formula from the melt flow rates (MFR) of the propylene-ethylene random block copolymer (c) and the propylene-ethylene random copolymer (c-1), and the content ratios of (c-1) and (c-2) in the random block copolymer (c). Log e[MFR of random block copolymer (c)] = [content of (c-1)] × Log e [MFR of (c-1)] + [content ratio of (c-2)] × Log e [MFR of (c-2)]

[0097] (2) Calculation of the ethylene content of the propylene polymer (A) and the propylene-ethylene random copolymer (C) 13 Using an ethylene-propylene random copolymer whose ethylene content was verified by C-NMR as a reference material, infrared spectroscopy was performed and the peak was observed at 720-730 cm -1 A calibration curve of absorbance vs. ethylene content was prepared from the peaks due to ethylene appearing around 1000 nm. Using the calibration curve thus obtained, the ethylene contents of the propylene polymer (A) and the propylene-ethylene random copolymer (C) (including the propylene-ethylene random block copolymer (c) and the propylene-ethylene random copolymer (c-1)) were calculated. For infrared spectroscopy, pellets of each copolymer were press-molded into films with a thickness of approximately 500 μm.

[0098] The ethylene content of the propylene-ethylene random copolymer (c-2) was calculated from the ethylene contents of the random block copolymers (c) and (c-1) and the content ratios of (c-1) and (c-2) in the random block copolymer (b).

[0099] (3) Melting peak temperature (melting point) (Tm, unit: °C): The melting peak temperature of the propylene-ethylene random block copolymer (c) was measured using a differential scanning calorimeter (DSC). A sample of 5.0 mg was heated to 200°C, and after the thermal history was erased, 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. The top temperature of the endothermic peak when the sample was then melted at a heating rate of 10°C / min was taken as the melting peak temperature (melting point) (Tm).

[0100] (4) Calculation of the amount of each component of the propylene-ethylene random block copolymer (c) The contents of propylene-ethylene random copolymers (c-1) and (c-2) in the propylene-ethylene random block copolymer (c) were calculated using temperature-rising elution fractionation (TREF). The apparatus and measurement conditions were as follows:

[0101] [Device] (TREF section) TREF column: 4.3mmφ×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

[0102] (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℃

[0103] (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 long round, synthetic sapphire window plate Temperature during measurement: 140℃ (Pump section) Liquid transfer pump: Senshu Scientific SSC-3461 pump

[0104] [Measurement conditions] Solvent: o-dichlorobenzene (containing 0.5 mg / mL BHT) Sample concentration: 5 mg / mL Sample injection volume: 0.1 mL Solvent flow rate: 1 mL / min

[0105] (5) Coefficient of kinetic friction Measurement equipment: Tribogear TYPE14 manufactured by Shinto Scientific Co., Ltd. A propylene-based polymer composition was injection-molded to a thickness of 1 mm at a molding temperature of 200°C and a mold temperature of 40°C to prepare a test specimen. Two test specimens measuring 120 mm × 120 mm × 1 mm and 20 mm × 20 mm × 1 mm were cut from the test specimen obtained in this manner and stored at 23°C and 50% RH for 24 hours. Thereafter, under the same environment, the 120 mm × 120 mm × 1 mm test specimen was placed on the lower side of the apparatus and the 20 mm × 20 mm × 1 mm test specimen was placed on the upper side of the apparatus, and the coefficient of kinetic friction between the two test specimens was measured using a 20 mm square flat indenter at a total load of 200 g and a movement speed of 150 mm / min.

[0106] (6) Flexural modulus The flexural modulus was measured in accordance with JIS K7171.

[0107] (7) Charpy impact strength The Charpy impact strength at 23°C was measured in accordance with JIS K7111.

[0108] (8) Cracking test in MD and TD directions Test specimens measuring 120 mm x 120 mm x 2 mm were prepared by injection molding (molding temperature: 200°C, mold temperature: 40°C). As shown in Figure 1, two 15 mm wide, 30 mm long cuts were made in the MD and TD directions of the test specimens with pruning shears, and the cuts were bent by hand, and the cracks were evaluated according to the following criteria. ○: When bent by 90 degrees or more, even if splits (fissures, cracks) or whitening occur, the product does not separate into several parts (does not break). ×: If bent more than 90 degrees, it will break into several pieces (crack).

[0109] <2. Resins and additives> 2-1. Preparation of propylene-ethylene random block copolymer (c) (1) Production example 1 (PP-1) (i) Preparation of prepolymerized catalyst Chemical treatment of silicate: 3.75 L of distilled water was slowly added to a 10-L separable glass flask equipped with a stirring blade, followed by 2.5 kg of concentrated sulfuric acid (96%). At 50°C, 1 kg of montmorillonite (Mizusawa Industrial Chemicals, Benclay® SL; average particle size = 50 μm) was dispersed, and the mixture was heated to 90°C and maintained at that temperature for 6.5 hours. After cooling to 50°C, the slurry was filtered under reduced pressure to recover a cake. Seven liters of distilled water was added to the cake to re-slurry it, and the cake was then filtered. This washing procedure was repeated until the pH of the washing liquid (filtrate) exceeded 3.5. The recovered cake was dried overnight at 110°C under a nitrogen atmosphere. The dried cake weighed 707 g. The chemically treated silicate was then dried in a kiln dryer.

[0110] Catalyst preparation: 200 g of the dried silicate obtained above was placed in a 3-liter glass reactor equipped with a stirring blade, and 1160 ml of mixed heptane and 840 ml of a 0.60 M triethylaluminum heptane solution were added and stirred at room temperature. After 1 hour, the mixture was washed with mixed heptane and the silicate slurry was adjusted to 2.0 liters. Next, 9.6 ml of a 0.71 M triisobutylaluminum heptane solution was added to the prepared silicate slurry, and the reaction was carried out at 25°C for 1 hour. In parallel, 2177 mg (3 mmol) of [(r)-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4H-azulenyl}]zirconium] (synthesized according to the example in JP-A-10-226712) and 870 ml of mixed heptane were added with 33.1 ml of a heptane solution of triisobutylaluminum (0.71 M), and the mixture was allowed to react at room temperature for 1 hour. The reaction product thus obtained was added to the silicate slurry and stirred for 1 hour to obtain a silicate / metallocene complex slurry.

[0111] Prepolymerization: 2.1 L of normal heptane was introduced into a 10-L stirred autoclave that had been thoroughly purged with nitrogen and maintained at 40°C. The previously prepared silicate / metallocene complex slurry was then introduced. Once the temperature stabilized at 40°C, propylene was fed at a rate of 100 g / h to maintain the temperature. After 4 hours, the propylene feed was stopped and the temperature was maintained for an additional 2 hours. After completion of the prepolymerization, the remaining monomer was purged, the stirring was stopped, and the mixture was allowed to stand for approximately 10 minutes. Approximately 3 L of the supernatant was decanted. Next, 9.5 mL of a heptane solution of triisobutylaluminum (0.71 M / L) and 5.6 L of mixed heptane were added to the decanted residue. The mixture was stirred at 40°C for 30 minutes, allowed to stand for 10 minutes, and then 5.6 L of the supernatant was removed. This procedure was repeated three times. The final supernatant was analyzed for its components, revealing that the organoaluminum component concentration was 1.23 mmol / L and the Zr concentration was 8.6 × 10 -6 g / L, and the amount of Zr present in the supernatant relative to the charged amount (weight ratio) was 0.018 wt%. Subsequently, 17.0 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added to the residue after the decantation treatment, and then the mixture was dried under reduced pressure at 45°C. This procedure yielded a prepolymerized catalyst (metallocene catalyst) containing 2.16 g of polypropylene per 1 g of catalyst. Using this prepolymerization catalyst, a propylene-ethylene random block copolymer (c), which is a multistage polymer consisting of propylene-ethylene random copolymers (c-1) and (c-2), was produced according to the following procedure.

[0112] (ii) Production of propylene-ethylene random block copolymer (c) A continuous gas-phase polymerization reactor consisting of two horizontal polymerization vessels equipped with a stirrer was used. The first reactor (internal volume: 40 m) 3 The prepolymerized catalyst obtained above was continuously fed to the reactor at a rate of 130 g / hr, and triisobutylaluminum was continuously fed at a rate of 1.0 kg / hr. The ratio of the hydrogen concentration to the propylene concentration in the reactor was 1.6 × 10 -4 Hydrogen was added so that the molar ratio of ethylene to propylene was 5.8 x 10 -4Ethylene was supplied into the polymerization vessel so as to achieve the molar ratio, and propylene monomer was supplied so as to maintain the pressure inside the polymerization vessel at 2.25 MPa and the temperature at 62° C., to carry out the first polymerization reaction. The reaction heat was removed by the heat of vaporization of the raw material liquefied propylene. The propylene-ethylene random copolymer (c-1) produced in the polymerization reactor was continuously withdrawn so that the polymer retention level was 45% by volume of the reaction volume, and was supplied to the polymerization reactor for the second polymerization step.

[0113] Analysis of the propylene-ethylene random copolymer (c-1) obtained in the first polymerization reaction revealed that the yield per 1 g of solid catalyst of the polymer was 29 kg, the ethylene content was 1.9 wt%, the MFR (230°C and 2.16 kg load) was 6.9 g / 10 min, and the molecular weight distribution (Mw / Mn) was 2.3.

[0114] The second reactor (internal volume 40 m 3 ), in addition to the polymer from the first polymerization step, the ratio of hydrogen concentration to propylene concentration in the polymerization vessel was 4.3 × 10 -4 Hydrogen was supplied into the polymerization reactor so that the molar ratio was 0.36, ethylene was supplied so that the ratio of ethylene concentration to propylene concentration was 0.36, and propylene monomer was supplied so that the pressure inside the polymerization reactor was maintained at 2.2 MPa and the temperature was maintained at 70°C, to carry out a second polymerization reaction. The amount of each polymer obtained from the first and second polymerization reactions was adjusted by adding a polymerization activity inhibitor, and the reaction heat was removed by the heat of vaporization of the raw material liquefied propylene.

[0115] The propylene-ethylene random block copolymer (c) produced in the second polymerization step was continuously withdrawn from the polymerization reactor so that the polymer retention level was 55% by volume of the reaction volume. Analysis of the resulting propylene-ethylene random block copolymer (c) revealed that the polymer yield per 1 g of solid catalyst was 52 kg, the MFR (230°C and 2.16 kg load) was 7.2 g / 10 min, the ethylene content was 6.2 wt%, and Tm was 133°C.

[0116] Analysis of the propylene-ethylene random copolymer (c-2) obtained by the second polymerization reaction revealed that the MFR (230°C and 2.16 kg load) was 7.6 g / 10 min, the molecular weight distribution (Mw / Mn) was 2.4, and the ethylene content was 11.6 wt%. Here, the ethylene content of the random copolymer (c-2) was calculated from the ethylene contents of the random block copolymers (c) and (c-1) and the content ratios of (c-1) and (c-2) in the random block copolymer (b).

[0117] Figure 2 shows the results of the elution volume and integrated elution volume in the temperature-rising elution fractionation (TREF) measurement of the propylene-ethylene random block copolymer (c). T(α) corresponds to the elution peak temperature of the low-crystallinity (c-2), and T(β) corresponds to the elution peak temperature of the high-crystallinity (c-1). As shown in Figure 2, the elution peaks of T(α) and T(β) were sufficiently separable. Assuming that the cumulative amount W(α) of components eluted up to T(C) is the content of (c-2), and the cumulative amount W(β) of components eluted above T(C) is the content of (c-1), the contents of each component were calculated. As a result, the proportions of (c-1) and (c-2) in the propylene-ethylene random block copolymer (c) were 55.7 wt% and 44.3 wt%, respectively.

[0118] The resulting propylene-ethylene random block copolymer was designated PP-1. The formulation and physical properties of PP-1 are shown in Table 2.

[0119] [Table 1]

[0120] 2-2. Propylene polymer (A) Propylene homopolymer (a-1) (MA3) Manufactured by Nippon Polypro Co., Ltd., product name "NOVATEC PP MA3", MFR=11g / 10min, ethylene content=0% by weight Propylene-ethylene block copolymer (a-2) (BC02NC) NOVATEC PP BC02NC, manufactured by Japan Polypropylene Corporation, MFR = 20 g / 10 min, ethylene content = 7.2 wt% Propylene-ethylene random copolymer (a-3) (WFW4M) Made by Japan Polypropylene Corporation, trade name "WINTEC WFW4M", MFR = 7.0 g / 10 min, ethylene content = 1.9 wt%

[0121] 2-3.Polyethylene (B) (SGM9450F) Manufactured by Braskem, product name "Green PE SGM9450F", MFR=0.12g / 10min, density: 0.952g / cm 3 Biomass content: 96% (manufacturer catalog value) (HJ580N) Manufactured by Japan Polyethylene Co., Ltd., product name "NOVATEC HD HJ580N", MFR = 24 g / 10 min, density: 0.960 g / cm 3 (HJ340) NOVATEC HD HJ340, manufactured by Japan Polyethylene Co., Ltd., MFR = 3.0 g / 10 min, density: 0.953 g / cm 3 (UJ990) Manufactured by Japan Polyethylene Co., Ltd., product name "NOVATEC LL UJ990", MFR = 70 g / 10 min, density: 0.937 g / cm 3 (KF380) Manufactured by Japan Polyethylene Co., Ltd., product name "Kernel KF380", MFR = 8.0 g / 10 min, density: 0.918 g / cm 3 (KF370) Manufactured by Japan Polyethylene Co., Ltd., product name "Kernel KF370", MFR = 7.0 g / 10 min, density: 0.905 g / cm 3 (KM340T) Manufactured by Japan Polyethylene Co., Ltd., product name "Kernel KM340T", MFR = 7.0 g / 10 min, density: 0.880 g / cm 3

[0122] 2-4. Propylene-ethylene random copolymer (C) (PP-1) Propylene-ethylene random block copolymer (c) obtained by polymerization in Production Example 1, MFR = 7.2 g / 10 min, ethylene content = 6.2 wt% (VF3200) Dow Chemical Company, trade name "Versify 3200", MFR = 8.0 g / 10 min, ethylene content = 9.0 wt%

[0123] 2-5. Other additives (A-1) Hindered phenol antioxidant "IR1010" Tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxylphenyl)propionate]methane, product name "IRGANOX (registered trademark) 1010", manufactured by BASF Japan Ltd. (A-2) Phosphorus-based antioxidant "IF168" Tris(2,4-di-t-butylphenyl)phosphite, product name "IRGAFOS (registered trademark) 168", manufactured by BASF Japan Ltd. (B-1) Neutralizer "CAST" Calcium stearate, manufactured by NOF Corporation.

[0124] Examples 1 to 6 and Comparative Examples 1 to 4 and 6 to 11 Each polymer and additive were prepared in the blending ratios (parts by weight) shown in Tables 2 and 3, dry-blended in a Super Mixer, and then melt-kneaded and pelletized in a Shibaura Machine Co., Ltd. TEM-35B twin-screw extruder at a die outlet temperature of 220°C under a nitrogen atmosphere. The resulting pellets were used to measure physical properties. The evaluation results are shown in Tables 2 and 3.

[0125] Comparative Examples 5 and 12 to 15 and Reference Example 1 In Comparative Examples 5 and 12 to 15 and Reference Example 1, each pellet was used as it was to prepare a test piece, and the physical properties were measured. Note that, in Reference Example 1, which had a low MFR, the test piece was prepared at a molding temperature of 230° C. The evaluation results are shown in Tables 2 and 3.

[0126] [Table 2]

[0127] [Table 3]

[0128] As is clear from Tables 2 and 3, the propylene polymer compositions of Examples 1 to 6 contained the propylene polymer (A), polyethylene (B), and random copolymer (C) in the specified amounts, and the MFR of the compositions was 0.07 to 95 g / 10 min. The molded articles had a low dynamic friction coefficient and good slipperiness and slidability. The molded articles obtained from the compositions of Examples 1 to 4 were excellent in flexural modulus and impact resistance, and were free of cracks.

[0129] On the other hand, Comparative Examples 1, 6, and 7, in which the resin component was composed only of the propylene polymer (A), and Comparative Example 5, in which the resin component was composed only of the polyethylene (B), had high dynamic friction coefficients and poor slip properties. Furthermore, Comparative Examples 2 to 4, which contained the propylene polymer (A) and the polyethylene (B) but no random copolymer (C), and Comparative Example 8, in which the content of the random copolymer (C) per 100 parts by weight of the total of the propylene polymer (A) and the polyethylene (B) was less than 5 parts by weight, had good dynamic friction coefficients of the molded articles, but cracks occurred in the TD cracking test.

[0130] Comparison of Examples 5 and 6 and Comparative Examples 9 to 11 shows that the density of polyethylene is 0.920 g / cm 3 In Comparative Examples 9 to 11, where the density of the polyethylene is less than 0.920 to 0.965 g / cm, the dynamic friction coefficient of the molded product is high and the slipperiness is poor. 3In Examples 5 and 6, the coefficient of dynamic friction was 0.7 or less, and the slipperiness was good. Comparing Comparative Examples 1 to 5, Comparative Examples 2 to 4, in which the propylene homopolymer (a-1) was 15 to 85 parts by weight and the polyethylene (B) was 85 to 15 parts by weight, totaling 100 parts by weight, showed significantly lower coefficients of dynamic friction of the molded articles than Comparative Example 1, in which the propylene homopolymer (a-1) was 100 parts by weight, and Comparative Example 5, in which the polyethylene (B) was 100 parts by weight. This shows that using a total of 100 parts by weight of 15 to 85 parts by weight of propylene polymer (A) and 85 to 15 parts by weight of polyethylene (B), as in the present invention, is effective in lowering the coefficient of dynamic friction of the molded article. [Industrial Applicability]

[0131] A molded article obtained from the propylene polymer composition of the present invention has excellent lubricity, sliding properties, and scratch resistance even when the blending amounts of a lubricant and an antiblocking agent are reduced. The molded article can be suitably used for cosmetic containers and automobile-related parts.

Claims

1. A propylene-based polymer (A) selected from the group consisting of: a block copolymer (a-2) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 30% by weight; and a random copolymer (a-3) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, wherein the content of ethylene and the α-olefin having 4 or more carbon atoms is less than 3% by weight; Polyethylene (B); and a random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of the ethylene and the α-olefin having 4 or more carbon atoms being 3 to 17% by weight; A propylene-based polymer composition comprising: the propylene polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min, measured at 230°C under a load of 2.16 kg in accordance with JIS K7210, and a density of 0.920 to 0.965 g / cm ３ and the random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The composition contains 5 parts by weight or more and 50 parts by weight or less of a random copolymer (C) based on 100 parts by weight in total of 35 to 65 parts by weight of a propylene polymer (A) and 65 to 35 parts by weight of a polyethylene (B), The composition is a propylene-based polymer composition having a melt flow rate of 0.07 to 95 g / 10 min as measured at 230° C. under a load of 2.16 kg in accordance with JIS K7210.

2. 2. The propylene polymer composition according to claim 1, wherein a test piece is injection-molded to a thickness of 1 mm at a molding temperature of 200°C and a mold temperature of 40°C, and the test piece is stored at 23°C and 50% RH for 24 hours. After that, a dynamic friction coefficient between two test pieces is measured under the same environment using a 20 mm square flat indenter at a total load of 200 g and a movement speed of 150 mm / min, and the measured value is 0.7 or less.

3. A propylene-based polymer (A) which is a propylene homopolymer (a-1); Polyethylene (B); and a random copolymer (C) of propylene and at least one selected from ethylene and an α-olefin having 4 or more carbon atoms, the content of the ethylene and the α-olefin having 4 or more carbon atoms being 3 to 17% by weight; A propylene-based polymer composition comprising: the propylene polymer (A) has a melt flow rate of 0.5 to 100 g / 10 min as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The polyethylene (B) has a melt flow rate of 0.05 to 80 g / 10 min, measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg, and a density of 0.920 to 0.965 g / cm 3 ; the random copolymer (C) has a melt flow rate of 0.5 to 80 g / 10 min as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The composition contains 5 parts by weight or more and 50 parts by weight or less of a random copolymer (C) based on 100 parts by weight in total of 35 to 65 parts by weight of a propylene polymer (A) and 65 to 35 parts by weight of a polyethylene (B), the composition has a melt flow rate of 0.07 to 95 g / 10 min, as measured in accordance with JIS K7210 at 230°C under a load of 2.16 kg; The propylene-based polymer composition is injection-molded to a thickness of 1 mm at a molding temperature of 200°C and a mold temperature of 40°C, and the test pieces are stored at 23°C and 50% RH for 24 hours. After that, the dynamic friction coefficient between two test pieces is measured under the same environment using a 20 mm square flat indenter at a total load of 200 g and a movement speed of 150 mm / min, and the measured value is 0.280 or less.

4. The propylene-based polymer composition according to claim 1, wherein in (a-2), (a-3) and the random copolymer (C), at least one selected from ethylene and an α-olefin having 4 or more carbon atoms is ethylene or 1-butene.

5. The propylene-based polymer composition according to claim 1, 2 or 4, wherein in (a-2), (a-3) and the random copolymer (C), at least one selected from ethylene and an α-olefin having 4 or more carbon atoms is ethylene.

6. The propylene-based polymer composition according to claim 3, wherein in the random copolymer (C), at least one selected from ethylene and α-olefins having 4 or more carbon atoms is ethylene or 1-butene.

7. The propylene-based polymer composition according to claim 3 or 6, wherein in the random copolymer (C), at least one selected from ethylene and α-olefins having 4 or more carbon atoms is ethylene.

8. The propylene polymer composition according to any one of claims 1 to 7, wherein the composition is substantially free of lubricants and antiblocking agents.

9. A molded article comprising the propylene polymer composition according to any one of claims 1 to 8.

10. The molded article according to claim 9, which is a cosmetic container.

11. The molded article according to claim 9, which is for an automobile-related part.

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