Propylene polymer composition and molded article

Abstract

To provide a propylene-based polymer composition having a biomass degree of 8.4 to 49% which provides a molded product having excellent rigidity and impact resistance and causing no cracks even if containing biomass polyethylene and to provide a molded article of the same.SOLUTION: There is provided a propylene-based polymer composition having a biomass degree of 8.4 to 49% which comprises the total 100 pts.mass of 51 to 90 pts.of a propylene-based copolymer (a) satisfying the following conditions (A-i) to (A-iv) and 10 to 49 pts.wt. of biomass polystyrene (b). (A-i) a propylene-α-olefin random copolymer, (A-ii) an α-olefin content of 1 to 5 wt.%, (A-iii) a melt flow rate according to JIS K7210 (at 230°C under a load of 2.16 kg) of 0.5 to 100 g / 10 min, (A-iv) a melting peak temperature (Tm) of 126 to 152°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a propylene-based polymer composition having a biomass content of 8.4 to 49% and a molded article thereof, and more particularly to a propylene-based polymer composition that gives a molded article that is excellent in rigidity and impact resistance and does not crack even when it contains biomass polyethylene. In the present invention, "crackable" means that it breaks into several parts when a force is applied. Furthermore, "not crackable" means any of the following: (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, impact resistance, 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. Meanwhile, environmental pollution caused by plastics has become a problem in recent years, and how to address this issue is a challenge. One solution is to use carbon-neutral plant-derived plastics (biomass plastics). Plant-derived polypropylene has also been considered, but is not currently on the market, and the addition of biomass polyethylene to polypropylene is being investigated (see, for example, Patent Documents 1 and 2).

[0003] However, a mixture obtained by mixing polypropylene and biomass polyethylene and then melt-kneading them has poor miscibility, and molded articles obtained from the mixture tend to crack. For this reason, there is a demand for a polypropylene composition that has excellent miscibility even when it contains biomass polyethylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-34519 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-27171 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the situation of the prior art, an object of the present invention is to provide a propylene-based polymer composition having a biomass content of 8.4 to 49%, which gives molded articles that are excellent in rigidity and impact resistance and do not crack even when containing biomass polyethylene, and a molded article thereof. [Means for solving the problem]

[0006] The present inventors have conducted extensive research and have found a propylene-based polymer composition having a biomass content of 8.4 to 49%, which, when used with a specific propylene-based polymer mixture, gives molded articles that are excellent in rigidity and impact resistance and do not crack even when containing biomass polyethylene, and a molded article thereof, thereby completing the present invention. That is, the present invention provides a propylene-based polymer composition having a biomass degree of 8.4 to 49% as follows, and a molded article thereof.

[0007] [1] A propylene-based polymer composition containing 51 to 90 parts by weight of a propylene-based copolymer (a) that satisfies the following conditions (Ai) to (A-iv) and 10 to 49 parts by weight of a biomass polyethylene (b), totaling 100 parts by weight, and having a biomass content of 8.4 to 49%. (Ai) Propylene-α-olefin random copolymer. (A-ii) The α-olefin content is in the range of 1 to 5% by weight. (A-iii) The melt flow rate (hereinafter sometimes abbreviated as MFR) according to JIS K7210 (230°C, 2.16 kg load) is in the range of 0.5 to 100 g / 10 min. (A-iv) The melting peak temperature (Tm) is in the range of 126 to 152°C. [2] A propylene-based polymer composition containing 0.01 to 0.6 parts by weight of a nucleating agent based on 100 parts by weight of the propylene-based polymer composition according to [1]. [3] A molded article obtained using the propylene polymer composition according to [1] or [2]. [Effects of the Invention]

[0008] Molded articles produced using the propylene-based polymer composition of the present invention having a biomass content of 8.4 to 49% contribute to reducing environmental impact and are useful because they provide molded articles that are excellent in rigidity and impact resistance and do not crack even when they contain biomass polyethylene. 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 flow sheet used to explain the production of a propylene-ethylene random copolymer in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] The propylene-based polymer composition of the present invention contains 51 to 90 parts by weight of a propylene-based copolymer (a) and 10 to 49 parts by weight of a biomass polyethylene (b) that satisfy the following conditions (Ai) to (A-iv), totaling 100 parts by weight, and has a biomass content of 8.4 to 49%, and is characterized by contributing to a reduction in environmental load and not causing a decrease in performance. (Ai) Propylene-α-olefin random copolymer. (A-ii) The α-olefin content is in the range of 1 to 5% by weight. (A-iii) The melt flow rate (MFR) according to JIS K7210 (230°C, 2.16 kg load) is in the range of 0.5 to 100 g / 10 min. (A-iv) The melting peak temperature (Tm) is in the range of 126 to 152°C. The propylene polymer composition and molded article of the present invention will be described in detail below.

[0011] [1] Components constituting the propylene polymer composition (1) Propylene copolymer (a)

[0012] (i) α-olefin of propylene copolymer (a) The α-olefin content of the propylene copolymer (b) used in the present invention is in the range of 1 to 5 wt%, preferably 1.9 to 4.9 wt%, more preferably 3.4 to 4.9 wt%. At least 1 wt% provides sufficient crack resistance. From the viewpoint of rigidity, an α-olefin content of 5 wt% or less is preferred. Examples of the α-olefin used in copolymerization include α-olefins having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-hexene, and 1-octene. One or more α-olefins may be copolymerized with propylene. Among these, ethylene and 1-butene are preferred. Ethylene is more preferred. These propylene copolymers may be used in combination. Specific examples of propylene copolymers include binary or ternary random copolymers in which any amount of comonomer is combined, such as propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-1-hexene random copolymer, propylene-1-octene random copolymer, propylene-ethylene-1-butene random copolymer, propylene-ethylene-1-hexene random copolymer, propylene-1-butene-1-octene random copolymer, etc. Here, the respective contents of propylene and α-olefin are determined under the following conditions: 13 This is a value measured by the C-NMR method. Equipment: JEOL-GSX270 manufactured by JEOL Ltd. Concentration: 300mg / 2mL Solvent: orthodichlorobenzene

[0013] (ii) Melt flow rate (MFR) of propylene copolymer (a) The propylene copolymer (a) used in the present invention has a melt flow rate (MFR) in the range of 0.5 to 100 g / 10 min, preferably 5 to 60 g / 10 min, and more preferably 10 to 40 g / 10 min, according to JIS K7210 (230°C, 2.16 kg load). A melt flow rate (MFR) of 0.5 g / 10 min or more improves molding processability, resulting in a satisfactory product. Furthermore, a MFR of 100 g / 10 min or less improves mechanical strength. The melt flow rate (MFR) can be easily adjusted by adjusting the temperature and pressure, which are the polymerization conditions for the propylene copolymer (a), or by controlling the amount of hydrogen added in a method in which a chain transfer agent such as hydrogen is added during polymerization.

[0014] (iii) Catalyst for Propylene Copolymer (a) The catalyst used in the propylene copolymer (a) of the present invention is not particularly limited, but it is preferable to use a stereoregular catalyst, such as a Ziegler catalyst or a metallocene catalyst.

[0015] Examples of Ziegler catalysts include two-component catalysts consisting 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 further 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.

[0016] The metallocene catalyst is preferably a supported type. A particularly preferred example of the supported metallocene catalyst is an ion-exchanged layered silicate in which the support also functions as a co-catalyst, which is obtained by combining the following components [A], [B], and, if necessary, the component [C].

[0017] 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

[0018] Component [A] Metallocene complex Specifically, the compound represented by the following formula [I] can be used as the component [A]. Q(C5H 4-a R 1 a )(C5H 4-b R 2 b )MXY ···[I] In 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.

[0019] 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-membered ring or a seven-membered ring is formed, which, together with the above-mentioned conjugated five-membered ring, forms an indene ring or an azulene ring. a and b are integers satisfying 0≦a≦4 and 0≦b≦4. Examples of the bonding group Q that bridges two conjugated five-membered ring ligands include an alkylene group, an alkylidene group, a silylene group, and a germylene group. These may have hydrogen atoms substituted with alkyl groups, halogens, etc. A silylene group is particularly preferred.

[0020] 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

[0021] (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

[0022] (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 Group 4, 5 and 6 transition metal compounds such as titanium compounds and hafnium compounds. These compounds may be used in combination with the catalyst component and catalyst of the present invention.

[0023] 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, lizardite, 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.

[0024] The silicate used in the present invention may be a layered silicate having a mixed layer of the above (a) and (b). In the present invention, the silicate as the main component is preferably a silicate having a 2:1 type structure, more preferably a smectite group silicate, and particularly preferably montmorillonite.

[0025] The activity of these silicates can be improved by chemically treating them with an acid, a salt, an alkali, an oxidizing agent, a reducing agent, an organic solvent, or the like. The acid treatment removes impurities on the surface of the ion-exchange layered silicate particles, exchanges interlayer cations, and also dissolves some or all of the cations such as Al, Fe, and Mg in the crystal structure. The acid used in the acid treatment includes hydrochloric acid, nitric acid, sulfuric acid, etc., but inorganic acids are preferred, and sulfuric acid is particularly preferred. There are no particular restrictions on the acid treatment conditions, but the preferred conditions are a 5 to 50 wt % aqueous acid solution reacted at a temperature of 60 to 100°C for 1 to 24 hours, with the acid concentration being variable during the reaction. After the acid treatment, washing is usually performed. Washing is an operation for separating and removing the acid contained in the treatment system from the ion-exchanged layered silicate.

[0026] The salts used in the salt treatment are preferably selected to contain specific cations, preferably monovalent to tetravalent metal cations, and more preferably Li, Ni, Zn, or Hf cations. Specific examples of salts include the following: Examples of those with a Li cation include LiCl, LiBr, Li2SO4, Li3(PO4), Li(ClO4), Li2(C2O4), LiNO3, Li(OOCCH3), and Li2(C4H4O4). Examples of those with a Ni cation include NiCO3, Ni(NO3)2, NiC2O4, Ni(ClO4)2, NiSO4, NiCl2, and NiBr2. Examples of compounds with a Zn cation include Zn(OOCH3)2, Zn(CH3COCHCOCH3)2, ZnCO3, Zn(NO3)2, Zn(ClO4)2, Zn3(PO4)2, ZnSO4, ZnF2, ZnCl2, ZnBr2, and ZnI2. Examples of compounds with a cation of Hf include Hf(OOCCH3)4, Hf(CO3)2, Hf(NO3)4, Hf(SO4)2, HfOCl2, HfF4, HfCl4, HfBr4, and HfI4.

[0027] 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.

[0028] 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 4 represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen, hydrogen, an alkoxy group, or an amino group. p is an integer of 1 to 3, and q is an integer of 1 or 2. R 4 is preferably an alkyl group, and when X is an alkoxy group, it is preferably an alkoxy group having 1 to 8 carbon atoms, and when X is an amino group, it is preferably an amino group having 1 to 8 carbon atoms. Among these, preferred are trialkylaluminums where p=3 and q=1 and dialkylaluminum hydrides where p=2 and q=1. More preferred are R 4 is a trialkylaluminum having 1 to 8 carbon atoms.

[0029] The organoaluminum compounds can be used alone or in combination, and can be added not only during catalyst preparation but also during prepolymerization or main polymerization.

[0030] (iv) Method for producing propylene copolymer (a) Examples of methods for producing the propylene copolymer (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 polymerization 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 -80 to 150°C, preferably 40 to 120°C. The polymerization pressure is preferably 1 to 60 atmospheres (0.10 to 6.08 MPa), and the molecular weight of the resulting propylene copolymer (a) can be adjusted with hydrogen or other known molecular weight modifiers. The polymerization can be carried out by a continuous or batch reaction, and the conditions may be those usually used. Furthermore, the polymerization reaction may be carried out in one stage or 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]).

[0031] 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.

[0032] 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.

[0033] In the present invention, after the polymerization is completed, the resulting propylene copolymer (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 copolymer (a), commercially available products can be used, such as those available under the trade names WINTEC and NOVATEC PP manufactured by Japan Polypropylene Corporation.

[0034] (v) Molecular weight distribution (Mw / Mn) and weight average molecular weight (Mw) of propylene copolymer (a) The molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the propylene copolymer (a) used in the present invention, as determined by gel permeation chromatography (GPC), is preferably 1.5 to 7.0. The lower limit of the molecular weight distribution is more preferably 2.0 or more, and even more preferably 3.0 or more, and the upper limit is more preferably 6.0 or less, and even more preferably 5.0 or less. If the lower limit of the molecular weight distribution is above a certain level, the range of conditions for producing and purifying the propylene copolymer (a) is broadened, which is preferable, as it improves production efficiency. On the other hand, if the upper limit is below a certain level, it indicates that the molecular chain length is very uniform, which is preferable, as it reduces the content of relatively low molecular weight components such as unreacted monomers, dimers, low molecular weight compounds, amorphous components, and oligomers, which are thought to cause the generation of volatile components.

[0035] The weight-average molecular weight (Mw) of the propylene copolymer (a) used in the present invention is preferably in the range of 100,000 to 600,000. When the weight-average molecular weight Mw is 600,000 or less, molding is facilitated. On the other hand, when the weight-average molecular weight Mw is 100,000 or more, the amount of low-crystalline components is reduced, mold contamination, bleed-out, solvent elution, etc. are suppressed, and the impact resistance of molded articles is improved, which is practical.

[0036] (vi) Average elution temperature (T 50 ) and dissolution dispersion (σ) When a metallocene catalyst is used, the average elution temperature (T 50 ) is preferably 90 to 105°C, and the dissolution dispersion (σ) is preferably 9°C or less. Here, the average elution temperature is a value based on the elution curve of the polymer obtained by temperature rising elution fractionation using o-dichlorobenzene as a solvent, and represents the temperature at which the cumulative mass of the eluted polymer reaches 50% by mass. The elution dispersity is the value of σ when the cumulative mass elution amount I(t) is defined as expressed by the following mathematical formula (1), assuming that the elution amount obtained by temperature rising elution fractionation follows a normal probability distribution with respect to the elution temperature.

[0037]

number

[0038] (vii) Melting peak temperature (Tm) of propylene copolymer (a) The melting peak temperature (Tm) of the propylene copolymer (a) used in the present invention is in the range of 126°C to 152°C, preferably 126 to 148°C. When the melting peak temperature (Tm) is 126°C or higher, the rigidity and moldability are good, and when it is 152°C or lower, the impact strength is good. The specific method for measuring the melting peak temperature (Tm) is to use a differential scanning calorimeter (DSC) to take a 5.0 mg sample, hold it at 200°C for 5 minutes, crystallize it at a temperature drop rate of 10°C / min to 40°C, and then melt it at a temperature increase rate of 10°C / min. The peak position of the curve drawn when this is done is taken as the melting peak temperature Tm (°C).

[0039] (2) Biomass polyethylene (b) Plant-derived ethylene, which is the raw material monomer for the biomass polyethylene (b) used in the present invention, 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. Biomass polyethylene (b) is a polymer obtained by polymerizing a monomer containing plant-derived ethylene as the main component. The raw material monomer for biomass polyethylene (b) does not have to contain 100% plant-derived ethylene. This is because environmental impact can be reduced by using plant-derived ethylene as part of the monomer. The biomass polyethylene (b) may be a homopolymer obtained by homopolymerizing plant-derived ethylene or a copolymer 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 also be included.

[0040] Examples of polyethylenes that can be used as the biomass polyethylene (b) include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). These polyethylenes can be used alone or in combination of two or more. The density of the high-density polyethylene is preferably 0.940 to 0.965 g / cm 3 The density of the medium-density polyethylene is preferably 0.925 to 0.940 g / cm. 3 This range is preferable because it improves rigidity. Among the above polyethylenes, it is preferable to use at least one of low-density polyethylene and linear low-density polyethylene, which will provide a sufficient transparency-improving effect. The density of the low-density polyethylene is preferably 0.910 to 0.920 g / cm 3 and more preferably 0.913 to 0.917 g / cm 3 The density is 0.910 g / cm 3 If the density is 0.920 g / cm or more, the rigidity is improved, which is preferable. 3 If it is less than this, the transparency improving effect will be sufficient, which is preferable. The density of the linear low-density polyethylene is preferably 0.895 to 0.925 g / cm 3 and more preferably 0.900 to 0.917 g / cm 3 The density is 0.895g / cm 3 If the density is 0.925 g / cm or more, the rigidity is improved, which is preferable. 3 If it is less than this, the transparency improving effect will be sufficient, which is preferable.

[0041] The ratio of plant-derived carbon to the total carbon in biomass polyethylene (b) is called the bio-content. 14 This can be determined by measuring the concentration of C. In other words, there is a certain percentage of 14 C, while the carbon in petroleum-derived resins contains 14 Since it does not contain C, it is contained in biomass polyethylene (b). 14The bio content can be calculated by measuring the concentration of C. Specifically, if all the carbon in biomass polyethylene (b) is derived from petroleum, the bio content will be 0%, and if all the carbon in biomass polyethylene (b) is derived from plants, the bio content will be 100%. 14 Test methods for measuring the concentration of C include ASTM D6866. The biomass polyethylene (b) preferably has a melt flow rate in the range of 0.21 to 72 g / 10 min according to ASTM D1238 (190° C., 2.16 kg load).

[0042] The weight proportion of the biomass polyethylene (b) used in the propylene copolymer is 10 to 49 parts by weight, preferably 15 to 40 parts by weight. When it is 10 parts by weight or more, an environmental load reduction effect can be expected, and when it is 49 parts by weight or less, sufficient rigidity of the product can be obtained. (Here, a propylene polymer composition containing 51 to 90 parts by weight of the propylene polymer (a) and 10 to 49 parts by weight of the biomass polyethylene (b) is 100 parts by weight.) An example of such biomass polyethylene (b) is "Green PE" (trade name manufactured by Braskem).

[0043] (3) Biomass ratio The biomass ratio (%) in the present invention is a value calculated by the following formula. Biomass ratio (%) = [{A × (B ÷ 100)} / C] × 100 Formula (2) A: Weight of biomass polyethylene (b) B: Bio content of the bio-polyethylene used (%) C: Weight of propylene polymer composition The bio content (%) of the biomass polyethylene (b) can be measured and calculated according to ASTM D6866.

[0044] (4) Nucleating agent The propylene polymer composition of the present invention may contain preferably 0.01 to 0.6 parts by weight of a nucleating agent based on 100 parts by weight of the propylene polymer composition. Various common known nucleating agents can be used, such as sterically hindered amide compounds, metal salts of organic dicarboxylic acids, metal salts of organic monocarboxylic acids, sorbitol or its derivatives, nonitol or its derivatives, metal salts of diterpenic acids, or polymer nucleating agents. Among these, it is particularly preferable to contain a nucleating agent represented by the following formula (1) in order to achieve transparency.

[0045] [ka] ···(1) (wherein n is an integer of 0 to 2, and R 1 ~R 5 are each independently the same or different and represent hydrogen, halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, alkoxycarbonyl having 1 to 20 carbon atoms, or phenyl; R 6 is alkyl having 1 to 20 carbon atoms. Among the nucleating agents represented by formula (1), a representative commercially available product is Milad NX8000J (manufactured by Milliken & Company). Its chemical structural formula is shown below in formula (1-1). The molecular weight of this nucleating agent is 484. This substance is extremely stable both thermally and chemically, and has the excellent characteristic of hardly decomposing even at molding temperatures. This is highly desirable because it does not cause the problem of decomposition products bleeding out onto the surface of molded products and deteriorating their appearance.

[0046] [ka] ···(1-1)

[0047] The content of the nucleating agent represented by formula (1) contained in the propylene polymer composition of the present invention is preferably 0.1 to 0.6 parts by weight, more preferably 0.2 to 0.4 parts by weight, and even more preferably 0.3 to 0.4 parts by weight, relative to 100 parts by weight of the propylene polymer composition. When the content of the nucleating agent represented by formula (1) is 0.1 part by weight or more, rigidity and transparency can be expected to be exhibited, while when it is 0.6 part by weight or less, there is less concern about bleeding onto the surface of a molded article, which is advantageous in terms of cost-effectiveness (cost performance) in terms of rigidity and transparency and elution.

[0048] (5) Other additives In addition to the above-mentioned components, the propylene polymer composition of the present invention may contain additives such as various antioxidants used as stabilizers for propylene polymers, ultraviolet absorbers, light stabilizers, and neutralizers. Specifically, examples of the antioxidant include phosphorus-based antioxidants such as bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, di-stearyl-pentaerythritol 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. antioxidants, phenolic antioxidants such as 2,6-di-t-butyl-p-cresol, 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.

[0049] 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.

[0050] 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.

[0051] Further examples include amine-based antioxidants represented by the following formula (2) or (3), 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 (4).

[0052] [ka] ···(2)

[0053] [ka] ···(3)

[0054]

Chem.

[0055] Examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite (trade name: DHT-4A, a magnesium-aluminum composite hydroxide salt represented by the following formula (5) manufactured by Kyowa Chemical Industry Co., Ltd.), Mizukalac (trade name, a lithium-aluminum composite hydroxide salt represented by the following formula (6) manufactured by Mizusawa Chemical Industry Co., Ltd.), and the like. Mg 1-x Al x (OH)2(CO3) x / 2 ·mH2O …(5) [In the formula, x satisfies 0 < x ≤ 0.5, and m is a number of 3 or less.] [Al2Li(OH)6] n X·mH2O …(6) [In the formula, X is an inorganic or organic anion, n is the valence of the anion (X), and m is 3 or less.]

[0056] Furthermore, various known additives, such as antistatic agents, lubricants, dispersants such as fatty acid metal salts, dyes, pigments, etc., can be blended within a range that does not impair the object of the present invention.

[0057] As long as the properties and functions of the propylene-based polymer composition of the present invention are not impaired, 1 to 30 parts by weight of other polymers than the propylene-based copolymer (a) and the biopolyethylene (b), such as mono-, bi-, or 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, can be added relative to 100 parts by weight of the propylene-based polymer composition. Similarly, elastomers such as natural rubber, butyl rubber, diene rubber, EPR, and EPDM can also be blended. Furthermore, general-purpose inorganic fillers such as talc, calcium carbonate, silica, alumina, gypsum, and mica can also be used in combination.

[0058] (6) Flexural Modulus of Propylene Polymer Composition The flexural modulus of the propylene polymer composition of the present invention is preferably 500 MPa or more, and when the flexural modulus is 500 MPa or more, the strength of the molded article is sufficient, more preferably 800 MPa or more, and even more preferably 1000 MPa or more.

[0059] (7) Charpy impact strength of propylene polymer composition The Charpy impact strength of the propylene polymer composition of the present invention is preferably 3.0 kJ / m 2 Charpy impact strength is 3.0kJ / m or more. 2 If the viscosity is 3.5 kJ / m or more, damage to the molded product during transportation is suppressed. 2 or more, more preferably 4.8 kJ / m 2 That's all.

[0060] (8) Haze of Propylene Polymer Composition The haze of the propylene polymer composition of the present invention at a product thickness of 2 mm is preferably 50% or less, and a haze of 50% or less improves the visibility of the contents and improves the design, more preferably 45% or less, and even more preferably 35% or less.

[0061] [2] Method for producing propylene polymer composition The propylene polymer composition of the present invention can be obtained by mixing predetermined amounts of the propylene copolymer (a), the biomass polyethylene (b), 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 conventional single-screw extruder, a twin-screw extruder, a Banbury mixer, a plavender, a roll, or the like.

[0062] [3] Molded products obtained using propylene polymer compositions To produce a molded article using the propylene polymer composition of the present invention, the propylene polymer composition is molded into a molded article having a desired shape by injection molding or the like. The uses of the molded articles are not particularly limited, but they can be used in a wide variety of applications, such as various industrial materials, automobile-related parts, various containers for medical and cosmetic purposes, daily necessities, films, and fibers. [Example]

[0063] EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the physical properties of the propylene copolymer (a) and the propylene polymer composition were measured according to the following methods. <1. Measurement method>

[0064] (1) Melt flow rate (MFR): Measurement was performed in accordance with JIS K7210 (230°C, 2.16 kg load).

[0065] (2) Calculation of the ethylene content of propylene copolymer (a) 13 The ethylene-propylene random copolymer, the composition of which was verified by C-NMR, was used as the reference material. -1The ethylene content in the random copolymer was measured by infrared spectroscopy using the characteristic absorption band of the following: The pellets were press-molded into a film of about 500 μm thickness.

[0066] (3) Measurement of molecular weight and molecular weight distribution: The molecular weight distribution Mw / Mn of the propylene copolymer (a) was calculated by measuring the weight average molecular weight Mw and the number average molecular weight Mn by gel permeation chromatography (GPC) under the following conditions. Apparatus: WATERS GPC (ALC / GPC 150C) Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3 columns in series) Mobile phase solvent: ο-dichlorobenzene Measurement temperature: 140℃ Flow rate: 1.0ml / min Injection amount: 0.2ml

[0067] (4) Melting peak temperature (melting point) (Tm, unit: ° C.): Using a differential scanning calorimeter (DSC), a 5.0 mg sample was taken, the temperature was raised to 200°C, the thermal history was erased, and the sample was then held at 200°C for 5 minutes. The temperature was then lowered to 40°C at a rate of 10°C / min to crystallize the sample, and the temperature was then raised again at a rate of 10°C / min to melt the sample. The temperature at the top of the endothermic peak was taken as the melting peak temperature (melting point) (Tm).

[0068] (5) Flexural modulus (rigidity) Measurement was carried out in accordance with JIS K7171.

[0069] (6) Charpy impact strength (impact resistance) The Charpy impact strength at 23°C was measured in accordance with JIS K7111. (7) Haze value Measurement was carried out in accordance with JIS K7136 using a 2 mm thick sheet piece.

[0070] (9) Cracking test in MD and TD directions Test pieces measuring 120mm x 120mm x 2mm were injection molded (molding temperature: 200°C, mold temperature: 40°C), and a 3cm long cut was made in each piece with pruning shears to a width of 1.5cm as shown in Figure 1. The cut sections were then bent by hand, and the cracking was evaluated according to the following criteria. ◎: No splits (tears, cracks) or separation into several pieces even when bent more than 90 degrees. (No splits) ○: Even when bent more than 90 degrees, a split (crack) occurs, but it does not separate into several parts (does not split). ×: When bent more than 90 degrees, it separates into several parts (cracks).

[0071] <2. Resins and additives> 2-1. Production of propylene copolymer (a) (1) Manufacturing Example 1 <Preparation of solid titanium catalyst component> A 10 L autoclave equipped with a stirrer was thoroughly purged with nitrogen, and 2 L of purified toluene was introduced. 200 g of Mg(OEt)2 and 1 L of TiCl4 were added at room temperature. The temperature was raised to 90°C, and 50 mL of di-n-butyl phthalate was added. The temperature was then raised to 110°C, and the reaction was carried out for 3 hours. The reaction product was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total liquid volume to 2 L. 1 L of TiCl4 was added at room temperature, and the temperature was raised to 110°C, and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total liquid volume to 2 L. 1 L of TiCl4 was added at room temperature, and the temperature was raised to 110°C, and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Furthermore, purified n-heptane was used to replace the toluene with n-heptane, and a slurry of solid components was obtained. A portion of this slurry was sampled and analyzed, and the Ti content of the solid component was found to be 2.7 wt %. Next, a 20 L autoclave equipped with a stirrer was thoroughly purged with nitrogen, and 100 g of the above solid component slurry was introduced as the solid component. Purified n-heptane was introduced to adjust the solid component concentration to 25 g / L. 50 ml of SiCl4 was added, and the reaction was carried out at 90°C for 1 hour. The reaction product was thoroughly washed with purified n-heptane. Purified n-heptane was then introduced to adjust the liquid level to 4 L. 30 ml of dimethyldivinylsilane, 30 ml of (i-Pr)2Si(OMe)2, and 80 g of Et3Al diluted in n-heptane (as Et3Al) were added, and the reaction was carried out at 40°C for 2 hours. The reaction product was thoroughly washed with purified n-heptane, and a portion of the resulting slurry was sampled, dried, and analyzed. The solid components contained 1.2 wt% Ti and 8.8 wt% (i-Pr)2Si(OMe)2. The solid component obtained above was then prepolymerized using the following procedure. Purified n-heptane was added to the slurry to adjust the solid component concentration to 20 g / L. After cooling the slurry to 10 °C, 10 g of EtAl diluted in n-heptane was added, and 280 g of propylene was added over 4 hours. After the propylene supply was completed, the reaction was continued for another 30 minutes. The gas phase was then thoroughly purged with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The resulting slurry was removed from the autoclave and vacuum-dried to obtain solid catalyst component (c). This solid catalyst component contained 2.5 g of polypropylene per gram of solid component. Analysis revealed that the portion of solid catalyst component (c) excluding polypropylene contained 1.0 wt% Ti and 8.2 wt% (i-Pr)2Si(OMe)2.

[0072] <Production of Propylene-Ethylene Random Copolymer> The production of a propylene-ethylene random copolymer will be described using the flow sheet shown in Figure 2. Two gas-phase polymerization reactors using polymerization vessels were used. The two polymerization vessels 1 and 10 had an inner diameter D of 2100 mm, a length L of 11000 mm, and an internal volume of 40 m. 3The reactor was a continuous horizontal gas-phase polymerization reactor (length / diameter = 5.2) equipped with an agitator. After thoroughly purging the interior of the polymerization vessel 1 with nitrogen, polypropylene powder, from which polymer particles with a particle size of 500 μm or less had been removed, was charged. Solid catalyst component (c) was continuously fed at 120 g / h, along with a 15 wt. % hexane solution of triethylaluminum at a molar ratio of 350 per mole of Ti atom in catalyst component (c). Hydrogen was fed into the polymerization vessel 1 so that the hydrogen / propylene ratio was 0.095, ethylene was fed so that the ethylene / propylene ratio was 0.020, and propylene monomer was fed into the polymerization vessel 1 so that the pressure and temperature within the vessel 1 were maintained at 2.10 MPa and 61°C, respectively. Reaction heat was removed by the heat of vaporization of the liquefied propylene feedstock, fed through the raw material gas feed pipe 3. Unreacted gas discharged from the polymerization vessel 1 was extracted through the unreacted gas extraction pipe 4, cooled, condensed, and then refluxed to the polymerization vessel 1 through the recycle gas pipe 2. The propylene-ethylene random copolymer (first stage) produced in the polymerization reactor 1 was continuously withdrawn from the polymerization reactor 1 through the polymer withdrawal pipe 5 so that the polymer retention level was 45% by volume of the reaction volume, and was supplied to the polymerization reactor 10 for the second polymerization step. The polymer from the first polymerization step, hydrogen so that the ratio of hydrogen concentration to propylene concentration in the polymerization reactor 10 was 0.021, ethylene so that the ratio of ethylene concentration to propylene concentration in the polymerization reactor 10 was 0.068, and propylene monomer so that the pressure inside the polymerization reactor 10 was maintained at 2.05 MPa and the temperature at 70°C were all fed into the polymerization reactor 10. A polymerization inhibitor was supplied through a polymerization inhibitor addition pipe 11 to adjust the polymerization amount of the propylene-ethylene random copolymer (second stage). Reaction heat was removed by the heat of vaporization of the liquefied propylene feedstock supplied through a raw material gas mixture supply pipe 6. The unreacted gas discharged from the polymerization reactor 10 was extracted to the outside of the reactor system through an unreacted gas extraction pipe 8, cooled and condensed, and refluxed to the polymerization reactor 10 through a recycle gas pipe 7. The propylene copolymer produced in the second polymerization step was continuously withdrawn from the polymerization reactor 10 through a polymer withdrawal pipe 9 so that the polymer retention level was 50% by volume of the reaction volume. The withdrawn powder was separated into gases in a gas recovery device 12, and the powder portion was withdrawn to a recovery system and granulated in a granulation system. The production rate of the propylene copolymer was 9.6 T / hour, the average residence time in the polymerizer 1 was 1.9 hours, and the average residence time in the polymerizer 10 was 1.3 hours. The catalytic efficiency was calculated by dividing the production rate by the feed rate of the solid catalyst component (c), and was found to be 88,900 g-PP / g-catalyst. Analysis of the resulting propylene copolymer, the second-stage polymer, revealed that it had an MFR of 38.9 g / 10 min, an ethylene content of 5.0 wt%, and a Tm of 148°C. The PP component (first stage) had an MFR of 71.9 g / 10 min and an ethylene content of 2.5 wt%. Calculation of the index for the PP component (second stage) revealed that it had an MFR of 8.0 g / 10 min and an ethylene content of 11.3 wt%. The MFR of the second-stage PP component was calculated using the MFR of the first-stage PP component, the MFR of the propylene copolymer, and the weight ratio of the first-stage PP component to the second-stage PP component, according to an empirical formula known as the logarithmic additivity rule of viscosity. The ethylene content was calculated from the ethylene content of the first-stage PP component, the ethylene content of the propylene copolymer, and the weight ratio of the first-stage PP component to the second-stage PP component. The weight ratio of the first-stage PP component to the second-stage PP component was calculated from the amount of liquefied propylene supplied to the polymerization reactor, and the production amount of the second-stage PP component was 28 wt% of the total weight.

[0073] 2-2. Production of propylene copolymers other than propylene copolymer (a) (1) Manufacturing Example 2 (i) Preparation of solid catalyst A 100-liter reactor equipped with a stirring blade, thermometer, jacket, and cooling coil was charged with 30 mol of Mg(OEt)2. Ti(OBu)4 was then added so that the molar ratio of Ti(OBu)4 / Mg was 0.60 (mr). 19.2 kg of toluene (TOL) was then added and heated with stirring. After reacting at 139°C for 3 hours, the temperature was lowered to 130°C, and a toluene solution of MeSi(OPh)3 was added so that the molar ratio of MeSi(OPh)3 / Mg was 0.67 (mr) relative to the magnesium in the Mg(OEt)2. The amount of toluene used was 7.8 kg. After the addition was completed, the reaction was continued at 130°C for 2 hours. The temperature was then lowered to room temperature, and Si(OEt)4 was added. The amount of Si(OEt)4 added was set to Si(OEt)4 / Mg=0.056(mr) relative to the magnesium in the Mg(OEt)2 previously charged.

[0074] Next, toluene was added to the resulting reaction mixture to adjust the magnesium concentration to 0.58 (mol / L-TOL). Furthermore, diethyl phthalate (DEP) was added so that the DEP / Mg ratio was 0.10 (mr) relative to the magnesium in the Mg(OEt)2 previously charged. The resulting reaction mixture was cooled to 10°C with continued stirring, and TiCl4 was added dropwise over 2 hours to obtain a homogeneous solution. The TiCl4 was added so that the TiCl4 / Mg ratio was 4.0 (mr) relative to the magnesium in the Mg(OEt)2 previously charged. After the TiCl4 addition was completed, the mixture was heated to 15°C at 0.5°C / min with stirring and maintained at that temperature for 1 hour. The mixture was then heated again to 50°C at 0.5°C / min and maintained at that temperature for 1 hour. The mixture was then heated to 118°C at 1°C / min and maintained at that temperature for 1 hour. After the treatment was completed, stirring was stopped, the supernatant liquid was removed, and the residue was washed by decantation with toluene to a residual liquid ratio of 1 / 73 (volume ratio of toluene / solid component) to obtain a slurry of solid components.

[0075] Next, toluene and TiCl4 were added to the resulting slurry at room temperature. The TiCl4 was adjusted so that the ratio of TiCl4 / Mg(OEt)2 to the magnesium in the Mg(OEt)2 added earlier was 5.0 (mr). The toluene was adjusted so that the TiCl4 concentration was 2.0 (mol / L-TOL). The slurry was heated with stirring and reacted at 118°C for 1 hour. After the reaction was completed, stirring was stopped, the supernatant liquid was removed, and the mixture was decanted with toluene to a residual liquid ratio of 1 / 150 (volume ratio of toluene / solid component), yielding a solid component slurry.

[0076] (ii) Preparation of solid catalyst component (A) Of the solid component obtained in (i), 400 g was transferred to another reactor equipped with a stirring blade, thermometer, and cooling jacket, and normal hexane was added to dilute the solid component to a concentration of 5.0 (g / L). Trimethylvinylsilane, TEA, and TBMDES were added to the resulting slurry at 15°C while stirring. TEA represents triethylaluminum, TBMDES represents t-butylmethyldiethoxysilane, and t-butyl represents a tertiary butyl group. The amounts of TEA, trimethylvinylsilane, and TBMDES added were 0.475 g, 0.137 g, and 0.167 g, respectively, per gram of solid component in solid catalyst component (A). After the addition, the mixture was maintained at 15°C for 1 hour while continuing to stir, and then the temperature was raised to 30°C and stirred at the same temperature for 2 hours. Next, the temperature was lowered again to 15°C, and while maintaining the same temperature, 4.8 kg of propylene gas was fed at a constant rate into the gas phase of the reactor over 8 hours to carry out prepolymerization. After the feed was completed, stirring was stopped, the supernatant liquid was removed, and the mixture was washed by decantation with normal hexane to obtain a slurry of solid catalyst component (A). The residual liquid ratio was 1 / 12 (volume ratio of normal hexane / solid catalyst component (A)). The obtained solid catalyst component (A) contained 12.0 g of propylene polymer per 1 g of solid catalyst component (A).

[0077] (iii) Production of propylene-ethylene copolymers Internal volume 0.4m 3A continuous production of propylene-ethylene copolymer was carried out using a process incorporating a degassing system consisting of a double-pipe heat exchanger and a fluidized flash tank downstream of a liquid-phase polymerization reactor equipped with an agitator. Liquefied propylene, ethylene, hydrogen, TEA, and TBEDMS were continuously fed into the liquid-phase polymerization reactor. TBEDMS stands for t-butylethyldimethoxysilane, and t-butyl stands for tertiary butyl group. The feed rates of liquefied propylene, TEA, and TBEDMS were 163 kg / hr, 8.86 g / hr, and 1.37 g / hr, respectively. Hydrogen and ethylene were fed to gas phase concentrations of 6.15 mol% and 0.74 mol%, respectively. Furthermore, the solid catalyst component (A) obtained in (ii) above was fed to a rate of 0.13 g / hr as the solid component contained in (A). The liquid-phase polymerization reactor was cooled to maintain the polymerization temperature at 70°C. The slurry polymerized in the liquid-phase polymerization vessel was heated in a double-pipe heat exchanger and discharged into a fluidized flash vessel. The discharge rate of the slurry was adjusted so that the polypropylene particles contained in the slurry were approximately 24 kg / hr. The average residence time of the polypropylene particles in the liquid-phase polymerization vessel was 1.4 hours. Analysis of the discharged polypropylene revealed an MFR of 25.0 g / 10 min, an ethylene content of 0.7 wt%, a molecular weight distribution (Mw / Mn) of 5.6, and a Tm of 156°C.

[0078] (2) Manufacturing Example 3 A propylene-ethylene copolymer was produced in accordance with Production Example 2, except that the feed rate was changed so that the ethylene concentration in the gas phase was 0.85 mol %. Analysis of the obtained polypropylene revealed that it had an MFR of 21.0 g / 10 min, an ethylene content of 0.8 wt %, a molecular weight distribution (Mw / Mn) of 5.7, and a Tm of 159°C.

[0079] 2-3. Propylene copolymer (a) (PP-1) Japan Polypropylene Corporation, trade name "WINTEC WFW4M", MFR = 7.0 g / 10 min, ethylene content = 1.9 wt%, Tm = 133°C (PP-2) Japan Polypropylene Corporation, trade name "WINTEC WSX03", MFR = 25 g / 10 min, ethylene content = 3.4 wt%, Tm = 126 °C (PP-3) NOVATEC-PP MG03BD, manufactured by Japan Polypropylene Corporation, MFR = 30 g / 10 min, ethylene content = 2.2 wt%, Tm = 152 °C (PP-4) Propylene-based resin obtained by polymerization in Production Example 1 2-4. Propylene-based copolymers other than propylene-based copolymer (a) (PP-5) Propylene-based resin obtained by polymerization in Production Example 2 (PP-6) Propylene-based resin obtained by polymerization in Production Example 3

[0080] 2-5. Biomass polyethylene (b) Low-density polyethylene (LDPE) (PE-1)Braskem product name "Green PE SPB608" Density: 0.915g / cm 3 The melt flow rate conforming to ASTM D1238 (190°C, 2.16 kg load) is 30 g / 10 min, and the bio content is 95%. (All properties are listed in the manufacturer's catalog.) Linear low-density polyethylene (LLDPE) (PE-2)Braskem product name "Green PE SLL118" Density: 0.916g / cm 3 The melt flow rate conforming to ASTM D1238 (190°C, 2.16 kg load) is 1 g / 10 min, and the bio content is 87%. (All properties are listed in the manufacturer's catalog.) High-density polyethylene (HDPE) (PE-3)Braskem product name "Green PE SGM9450F" Density: 0.952g / cm 3 The melt flow rate conforming to ASTM D1238 (190°C, 5 kg load) is 0.33 g / 10 min, and the bio content is 96%. (All properties are listed in the manufacturer's catalog.)

[0081] 2-6. Other additives (A-1) Hindered phenolic antioxidant "IR1010" tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxylphenyl)propionate]methane. Manufactured by BASF Japan Ltd., trade name "IRGANOX 1010". (A-2) Phosphorus-based antioxidant "IF168" tris(2,4-di-t-butylphenyl) phosphite. Manufactured by BASF Japan Ltd., trade name "IRGAFOS168". (B-1) Neutralizer "CAST" calcium stearate. Manufactured by NOF Corporation. (N-1) Nucleating agent "NX8000J" 1,2,3-trideoxy-4,6:5,7-bis-[(4-propylphenyl)methylene]-nonitol. Manufactured by Milliken & Company, trade name "Milad NX8000J".

[0082] 3. Examples 1 to 11 and Comparative Examples 1 to 4 Each polymer and additive were prepared in the blending ratio (parts by weight) shown in Table 1, dry-blended in a Super Mixer, and then melt-kneaded and pelletized in a nitrogen atmosphere at a die outlet temperature of 220°C using a TEM-35B twin-screw extruder manufactured by Toshiba Machine Co., Ltd. The resulting pellets were used to measure physical properties. The evaluation results are shown in Table 1.

[0083] [Table 1]

[0084] As is clear from Table 1, Examples 1 to 11 contain the specified amounts of the propylene-based copolymer (a) and biomass polyethylene (b) according to the present invention, and are materials that can reduce environmental impact. They are excellent in rigidity and impact resistance and do not crack. Examples 1 to 4 contain the specified amounts of LDPE as the biomass polyethylene (b), and are also excellent in transparency. Example 5 has the same composition as Example 1, but with an increased amount of LDPE as the biomass polyethylene (b). This increases the biomass content while improving impact resistance, demonstrating superiority in terms of environmental impact. Example 6 has the same composition as Example 1, but with a reduced amount of LDPE as the biomass polyethylene (b). This shows that the rigidity and transparency are superior to those of Example 1. Example 7 uses LLDPE as the biomass polyethylene (b). Although the content is the same as in Example 1, the impact resistance is improved compared to Example 1. Example 8 uses HDPE as the biomass polyethylene (b). Although the content is the same as in Example 1, the rigidity is improved compared to Example 1. Example 9 uses LLDPE as the biomass polyethylene (b), has the same content as Example 2, and has similar rigidity and impact resistance to Example 2. Example 10 uses HDPE as the biomass polyethylene (b), and has the same content as Example 2, but has improved rigidity compared to Example 2. Example 11 has the same composition as Example 1 but does not contain a nucleating agent, and it can be seen that the rigidity and impact resistance of Example 1 are further improved compared to Example 11 due to the nucleating action of the nucleating agent. On the other hand, Comparative Example 1 is slightly superior to Example 1 in rigidity and transparency, but is found to crack in a TD cracking test. Comparative Examples 2 and 3 are excellent in both rigidity and impact resistance and have sufficient cracking resistance, but the content of biomass polyethylene (b) LDPE is low and they do not have a sufficient biomass content. Comparative Example 4 is excellent in both rigidity and impact resistance, being comparable to Example 1, but is found to crack in a TD cracking test. [Industrial Applicability]

[0085] The propylene polymer composition of the present invention gives molded articles that are excellent in rigidity and impact resistance and do not crack even when it contains biomass polyethylene, and since the biomass content is 8.4 to 49%, it can be used to reduce the environmental load and is therefore useful. [Explanation of symbols]

[0086] Figure 2 1.Polymerization vessel (first polymerization step) 2.Recycled gas piping 3. Raw material mixed gas supply piping 4. Unreacted gas extraction piping 5. Polymer withdrawal piping 6. Raw material mixed gas supply piping 7.Recycled gas piping 8. Unreacted gas extraction piping 9. Polymer withdrawal piping 10.Polymerization vessel (second polymerization step) 11. Polymerization inhibitor addition piping 12.Gas recovery machine

Claims

1. A propylene-based polymer composition for injection molding contains 51 to 90 parts by weight of a propylene-based copolymer (a) that satisfies the following conditions (A-i) to (A-iv) and 10 to 49 parts by weight of a biomass polyethylene (b), totaling 100 parts by weight, and having a biomass content of 8.4 to 49%. (Ai) Propylene-α-olefin random copolymer. (A-ii) The α-olefin content is in the range of 1 to 5% by weight. (A-iii) The melt flow rate according to JIS K7210 (230°C, 2.16 kg load) is in the range of 0.5 to 100 g / 10 min. (A-iv) The melting peak temperature (Tm) is in the range of 126 to 152°C.

2. 2. A propylene polymer composition for injection molding, comprising 0.01 to 0.6 parts by weight of a nucleating agent per 100 parts by weight of the propylene polymer composition for injection molding according to claim 1.

3. A molded article obtained by using the propylene polymer composition for injection molding according to claim 1 or 2.

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