JP7619134B2 - Propylene-based polymer composition and molded article - Google Patents

Description

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 which gives a molded article having excellent rigidity and which does not crack even when it contains biomass polyethylene. In the present invention, "crack" means that the composition is divided into several parts when a force is applied. In addition, "does not crack" means any of the following:
(1) It does not split into several parts without any fissures (cracks, fissures).
(2) A fissure (crack, split) forms, but it does not separate into several parts.

Propylene-based resins are characterized by their excellent rigidity, heat resistance, moldability, transparency and chemical resistance, and are therefore used in a wide range of applications, including various industrial materials, automobile-related parts, various medical and cosmetic containers, daily necessities, films and fibers.
Meanwhile, in recent years, environmental pollution caused by plastics has become a problem, and how to deal with this issue is a challenge. One of the ways to deal with this problem 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 has been considered (see, for example, Patent Documents 1 and 2).

However, the mixture obtained by mixing polypropylene and biomass polyethylene and melt-kneading it 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.

JP 2019-34519 A JP 2016-27171 A

In light of the situation of the prior art, the object of the present invention is to provide a propylene-based polymer composition with a biomass content of 8.4 to 49%, which gives molded articles that are excellent in rigidity and do not crack even when they contain biomass polyethylene, and a molded article made from the composition.

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, by using a specific propylene-based polymer mixture, gives a molded article that is excellent in rigidity and does not crack even when it contains 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 content of 8.4 to 49% as described below, and a molded article thereof.

[1] A propylene-based polymer composition containing 26 to 87 parts by weight of a propylene-based (co)polymer (a) satisfying the following conditions (Hi) to (H-ii), 3 to 25 parts by weight of a propylene-based copolymer (b) satisfying the following conditions (A-i) to (A-iii), and 10 to 49 parts by weight of a biomass polyethylene (c), the total of which is 100 parts by weight, and the biomass degree is 8.4 to 49%.
(Hi) A propylene homopolymer or a propylene copolymer comprising propylene and an α-olefin in an amount of less than 1% by weight.
(H-ii) 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.
(Ai) Propylene-α-olefin random copolymer.
(A-ii) The α-olefin content is in the range of 1% by weight or more and less than 3% by weight.
(A-iii) The MFR is in the range of 0.5 to 80 g/10 min.
[2] The propylene-based polymer composition according to [1], in which the propylene-based copolymer (b) satisfies the following conditions (A-iv) to (A-v):
(A-iv) Metallocene-based propylene-ethylene random copolymer.
(Av) The melting peak temperature (Tm) is in the range of 126°C or higher and lower than 142°C.
[3] A propylene-based polymer composition comprising 0.01 to 0.6 parts by weight of a nucleating agent per 100 parts by weight of the propylene-based polymer composition according to [1] or [2].
[4] A molded article obtained by using the propylene polymer composition according to any one of [1] to [3].

Molded articles produced using the propylene-based polymer composition of the present invention, which has a biomass content of 8.4 to 49%, are useful because they contribute to reducing the environmental impact and provide molded articles that are excellent in rigidity and do not crack even when they contain biomass polyethylene. In particular, injection molded articles are extremely useful.

FIG. 1 is a diagram of a crack test in the MD and TD directions performed by making cuts in an injection test piece of 120 mm×120 mm×2 mm.

The propylene-based polymer composition of the present invention contains 26 to 87 parts by weight of a propylene-based (co)polymer (a) satisfying the following conditions (Hi) to (H-ii), 3 to 25 parts by weight of a propylene-based copolymer (b) satisfying the following conditions (A-i) to (A-iii), and 10 to 49 parts by weight of a biomass polyethylene (c), totaling 100 parts by weight, and has a biomass degree of 8.4 to 49%, which is characterized by contributing to a reduction in environmental load and not causing a decrease in performance.
(Hi) A propylene homopolymer or a propylene copolymer comprising propylene and an α-olefin in an amount of less than 1% by weight.
(H-ii) 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.
(Ai) Propylene-α-olefin random copolymer.
(A-ii) The α-olefin content is in the range of 1% by weight or more and less than 3% by weight.
(A-iii) The MFR is in the range of 0.5 to 80 g/10 min.
The propylene polymer composition and the molded article of the present invention will be described in detail below.

[1] Components constituting the propylene-based polymer composition (1) Propylene-based (co)polymer (a)

(i) α-Olefin of Propylene-Based (Co)polymer (a) The propylene-based (co)polymer (a) used in the propylene-based polymer composition of the present invention is preferably a propylene homopolymer, a propylene copolymer comprising propylene and an α-olefin having a content of less than 1% by weight, or a mixture thereof.
The propylene-based (co)polymer (a) is preferably a homopolymer from the viewpoint of rigidity, and is preferably a random copolymer consisting of propylene and an α-olefin from the viewpoint of transparency. The α-olefin used for copolymerization includes α-olefins having 2 to 20 carbon atoms excluding propylene, such as ethylene, 1-butene, 1-hexene, and 1-octene. The α-olefin copolymerized with propylene may be one type or two or more types. Among these, ethylene and 1-butene are preferred. Ethylene is more preferred. These propylene-based polymers may be used in combination of two or more types. From the viewpoint of rigidity, it is preferred that the content of the α-olefin is less than 1% by weight.

Specific examples of propylene-based copolymers include binary or ternary copolymers in which small amounts of comonomers are optionally combined, 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, and propylene-1-butene-1-octene copolymer.

The α-olefin content of the propylene-based (co)polymer (a) is preferably less than 1% by weight, more preferably less than 0.8% by weight, and even more preferably less than 0.5% by weight. When the α-olefin content is less than 1% by weight, the rigidity is improved and there is no risk of deformation when the containers are stacked.
Here, the contents of propylene and α-olefin are values measured by ¹³ C-NMR under the following conditions.
Equipment: JEOL-GSX270 manufactured by JEOL Ltd.
Concentration: 300mg/2mL
Solvent: orthodichlorobenzene

(ii) Melt flow rate (MFR) of propylene (co)polymer (a)
The propylene-based (co)polymer (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). When the melt flow rate (MFR) is 0.5 g/10 min or more, the molding processability is improved, and a product that is satisfactory can be obtained. When the MFR is 100 g/10 min or less, the mechanical strength is improved.
The melt flow rate (MFR) can be easily adjusted by adjusting the temperature and pressure, which are the polymerization conditions for the propylene-based (co)polymer (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.

(iii) Stereoregularity of Propylene-Based (Co)polymer (a) When the propylene-based (co)polymer (a) used in the present invention is a propylene homopolymer, the isotactic pentad fraction 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 is satisfactory.
Here, the isotactic pentad fraction is a value measured by a proton decoupling method using ¹³ C-NMR.

(iv) Catalyst for Propylene-Based (Co)polymer (a) The catalyst for the propylene-based (co)polymer (a) used in the present invention is not particularly limited, but it is preferable to use a stereoregular catalyst. Examples of the stereoregular catalyst include Ziegler catalysts and metallocene catalysts.

Examples of Ziegler catalysts include two-component catalysts consisting of transition metal components such as titanium halide compounds, such as titanium trichloride, titanium tetrachloride, and trichloroethoxytitanium, contact products of the titanium halide compounds with magnesium compounds, such as magnesium halides, and organometallic components, such as alkylaluminum compounds or their halides, hydrides, and alkoxides, and further three-component catalysts in which electron donor compounds containing nitrogen, carbon, phosphorus, sulfur, oxygen, silicon, etc. are added to the above components.

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

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

Component [A] Metallocene Complex Specifically, the compound represented by the following formula [I] can be used as the component [A].
Q(C ₅ H _4-a R ¹ _a ) (C ₅ H _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.

^R1 and ^R2 each independently represent 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. Two adjacent ^R1s or two adjacent ^R2s may be bonded to form a _C4 to _C10 ring. In particular, it is preferable that they form a 6-membered ring or a 7-membered ring, and together with the above-mentioned conjugated 5-membered ring, form 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 bridging two conjugated five-membered ring ligands include an alkylene group, an alkylidene group, a silylene group, and a germylene group. These groups may have hydrogen atoms substituted with alkyl groups, halogens, etc. A silylene group is particularly preferred.

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

(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

(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 As for other transition metal compounds of Groups 4, 5, and 6, such as titanium compounds and hafnium compounds, the same compounds as those mentioned above are also preferred. These compounds may be used in combination with the catalyst component and catalyst of the present invention.

Component [B] Co-catalyst (ion-exchange layered silicate)
The ion-exchangeable layered silicate is not limited to a natural product, and may be an artificially synthesized product. A clay compound can be used as the ion-exchangeable layered silicate, and specific examples of the clay compound include the following layered silicates described in "Clay Mineralogy" by Haruo Shiramizu, Asakura Publishing (1995).
(A) Kaolin group, such as dickite, nacrite, kaolinite, anoxicite, 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, etc., attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group, etc., whose main constituent layers are 2:1 type structures

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 main component silicate is preferably a silicate having a 2:1 type structure, more preferably a smectite group silicate, and particularly preferably montmorillonite. The main component means the component that is the most abundant.

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 can remove impurities on the surface of the ion-exchangeable layered silicate particles, exchange interlayer cations, and also dissolve some or all of the cations such as Al, Fe, Mg, etc. in the crystal structure.
The acid used in the acid treatment includes hydrochloric acid, nitric acid, sulfuric acid, etc., and is preferably an inorganic acid, and particularly preferably sulfuric acid.
There are no particular limitations on the acid treatment conditions, but the conditions are preferably such that a 5 to 50% by weight aqueous acid solution is reacted at a temperature of 60 to 100°C for 1 to 24 hours, and the acid concentration may be changed 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-exchange layered silicate.

The salts used in the salt treatment are preferably selected from those containing specific cations. The types of cations are preferably monovalent to tetravalent metal cations, and particularly preferably Li, Ni, Zn, or Hf cations.
Specific examples of salts include the following:
Examples of compounds whose cation is Li include LiCl, LiBr, _{Li2SO4 , Li3} ( _PO4 ), Li( _ClO4 ), _Li2 ( _C2O4 ), _{LiNO3 , Li} ( _OOCCH3 ), and _Li2 ( _{C4H4O4 )} .
Examples of those having Ni as a 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 having a cation of Hf include Hf( _OOCCH3 ) ₄ , Hf( _CO3 ) ₂ , Hf( _NO3 ) ₄ , Hf( _SO4 ) ₂ , _HfOCl2 , _HfF4 , _HfCl4 , _HfBr4 , and _HfI4 .

After the chemical treatment, drying is performed. Generally, drying temperatures of 100 to 800°C can be used, and high temperature conditions that cause structural destruction (for example, 800°C or higher, depending on the heating time) are not preferred. Even if the structure is not destroyed, the characteristics 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 reduced pressure. There are no particular limitations on the drying method, and various methods can be used.

Component [C] Organoaluminum Compound The organoaluminum compound of component [C] is a component that is optionally used as required, and is most preferably a compound represented by the following formula [II]:
(AlR ⁴ _p X _3-p ) _q ...[II]
In formula [II], ^R4 represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen atom, a hydrogen atom, an alkoxy group, or an amino group, p represents an integer of 1 to 3, and q represents 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.
Of these, preferred are trialkylaluminums where p = 3 and q = 1 and dialkylaluminum hydrides where p = 2 and q = 1. More preferred are trialkylaluminums where R ⁴ has 1 to 8 carbon atoms.

The organoaluminum compounds can be used alone or in combination. In addition, the organoaluminum compounds can be added not only during catalyst preparation, but also during prepolymerization or main polymerization.

(v) Method for Producing Propylene-Based (Co)polymer (a) Examples of methods for producing the propylene-based (co)polymer (a) include a slurry polymerization method using an inert solvent in the presence of the above catalyst, a solution polymerization method, a gas phase polymerization method substantially without using a 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., and preferably 40 to 120° C. The polymerization pressure is preferably 1 to 60 atm (0.10 to 6.08 MPa), and the molecular weight of the resulting propylene-based (co)polymer (a) can be adjusted with hydrogen or other known molecular weight regulators. The polymerization is 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 in multiple stages.
When a metallocene catalyst is used, it is desirable to carry out a prepolymerization treatment before carrying out the main polymerization. As the monomer to be subjected to the prepolymerization, an α-olefin such as ethylene, propylene, 1-butene, 1-hexene, etc., a diene compound such as 1,3-butadiene, etc., or a vinyl compound such as styrene, divinylbenzene, etc. can be used.
This prepolymerization is preferably carried out in an inert solvent under mild conditions, and is desirably carried out so as to produce 0.01 to 1,000 g, preferably 0.1 to 100 g, of polymer per 1 g of solid catalyst (the total of components [A] and [B]).

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 the polymerization pressure on the higher side.

Usually, the polymerization temperature is selected from 60 to 90° C., and the polymerization pressure is selected from about 1.5 to 4 MPa. In particular, in the case of a bulk polymerization method, it is preferable that the polymerization temperature is selected from 60 to 80° C., and the polymerization pressure is selected from about 2.5 to 4 MPa in correlation with the temperature. On the other hand, in the case of a gas phase polymerization method, it is preferable that the polymerization temperature is selected from 70 to 90° C., and the polymerization pressure is selected from about 1.5 to 4 MPa.
Furthermore, it is possible to increase the polymer production amount per solid catalyst by increasing the residence time of the solid catalyst, but if it is too long, it will affect the productivity. The preferred residence time is 1 to 8 hours, more preferably 1 to 6 hours. It is desirable to set the polymerization conditions so that the polymer production amount per 1 g of solid catalyst including the carrier is 20 kg or more, preferably 25 kg or more, more preferably 30 kg or more.
Hydrogen may be present in the polymerization system as a molecular weight regulator. Furthermore, the polymerization may be carried out in multiple stages by changing the polymerization temperature, the concentration of the molecular weight regulator, etc.

In the present invention, after the completion of the polymerization, the obtained propylene-based (co)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 any known method can be used, such as decantation of the supernatant after contact treatment in a stirring tank, countercurrent washing, or separation from the washing liquid using a cyclone.
A deactivating agent may be added before or at the same time as washing. There is no particular limitation on the deactivating agent, and water, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, and mixtures thereof can be used.
As such a propylene-based (co)polymer (a), commercially available products can be used, such as those available from Japan Polypropylene Corporation under the trade names WINTEC and NOVATEC PP.

(vi) Molecular weight distribution (Mw/Mn) and weight average molecular weight (Mw) of the propylene (co)polymer (a)
The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the propylene (co)polymer (a) used in the present invention, as measured by gel permeation chromatography (GPC), is preferably from 1.5 to 7.0.
The lower limit of the molecular weight distribution is preferably 2.0 or more, more preferably 3.0 or more, and the upper limit is preferably 6.0 or less, more preferably 5.0 or less.
When the lower limit of the molecular weight distribution is a certain level or higher, the range of conditions for producing and purifying the propylene-based (co)polymer (a) is broadened, which is preferable since it improves production efficiency. On the other hand, when the upper limit is a certain level or lower, it indicates that the length of the molecular chain is very uniform, which is preferable since 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 considered to cause the generation of volatile components.

The weight-average molecular weight (Mw) of the propylene-based (co)polymer (a) used in the present invention is preferably in the range of 100,000 to 600,000. If the weight-average molecular weight Mw is 600,000 or less, molding is easy. On the other hand, if 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 the molded product is improved, which is practical.

(vii) Average elution temperature (T ₅₀ ) and elution dispersity (σ) of the propylene (co)polymer (a)
When a metallocene catalyst is used, the average elution temperature (T ₅₀ ) of the propylene (co)polymer (a) used in the present invention is preferably 90 to 105° C., and the elution dispersity (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 is 50 mass%. The elution dispersity is a value of σ when the elution amount obtained by temperature rising elution fractionation is assumed to follow a normal probability distribution with respect to the elution temperature, and the cumulative mass elution amount I(t) is defined as being expressed by the following mathematical formula (1).

・・・数式（１）
溶出分散度は具体的には、σ＝Ｔ_５０－Ｔ_１５．９である。なお、Ｔ_１５．９は積算質量が１５．９質量％となるときの温度を示す。
平均溶出温度が９０～１０５℃であることにより、プロピレン系（共）重合体（ａ）の分子量及び融点を成形のために適切なものとすることができ、寸法精度を向上させることができる。平均溶出温度が９０℃以上のときにはプロピレン系（共）重合体（ａ）の分子量及び融点が低くなり過ぎることはなく、成形品の寸法精度が良好となり、１０５℃以下のときにはプロピレン系樹脂の分子量及び融点が高くなり過ぎることはなく好ましい。
また、溶出分散度（σ）が９℃以下であることにより、温度上昇に伴う成分の溶出を抑えることができると共に、寸法精度を高めることができる。溶出分散度（σ）はより好ましくは７℃以下、さらに好ましくは６℃以下である。
このようなメタロセン触媒を用いるプロピレン系（共）重合体（ａ）としては、市販のものを用いることができ、例えば、日本ポリプロ（株）製の商品名：ウィンテック（ＷＩＮＴＥＣ）などを挙げることができる。

...Equation (1)
Specifically, the dispersity of the eluted solution is σ=T ₅₀ −T _15.9 , where T _15.9 indicates the temperature at which the cumulative mass is 15.9 mass %.
By having an average elution temperature of 90 to 105° C., the molecular weight and melting point of the propylene-based (co)polymer (a) can be made appropriate for molding, and the dimensional accuracy can be improved. When the average elution temperature is 90° C. or higher, the molecular weight and melting point of the propylene-based (co)polymer (a) do not become too low, and the dimensional accuracy of the molded product becomes good, and when it is 105° C. or lower, the molecular weight and melting point of the propylene-based resin do not become too high, which is preferable.
Moreover, by having the dissolution dispersity (σ) of 9° C. or less, it is possible to suppress dissolution of components due to an increase in temperature and to improve dimensional accuracy. The dissolution dispersity (σ) is more preferably 7° C. or less, and further preferably 6° C. or less.
As the propylene-based (co)polymer (a) using such a metallocene catalyst, commercially available products can be used, for example, the product name: WINTEC manufactured by Japan Polypropylene Corporation.

(2) Propylene-based copolymer (b)
(i) Catalyst for Propylene-Based Copolymer (b) The catalyst used for the propylene-based copolymer (b) is not particularly limited, but it is preferable to use a stereoregular catalyst. Examples of the stereoregular catalyst include Ziegler catalysts and metallocene catalysts. The Ziegler catalyst and metallocene catalyst are the same as those mentioned above. It is preferable to use a metallocene catalyst that is less likely to crack when containing biomass polyethylene (c).

(ii) α-olefin of propylene copolymer (b) The α-olefin content of the propylene copolymer (b) used in the present invention is in the range of 1% by weight or more and less than 3% by weight, preferably 1 to 2.9% by weight, more preferably 1.5 to 2.4% by weight. If it is 1% by weight or more, the impact resistance is sufficient, and if it is less than 3% by weight, high rigidity can be maintained and the mold releasability during injection molding is good. The α-olefin used for copolymerization includes α-olefins having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-hexene, and 1-octene. The α-olefin copolymerized with propylene may be one type or two or more types. Among these, ethylene and 1-butene are preferred. More preferred is ethylene. In addition, these propylene copolymers may be used in a mixture of two or more types.
Specific examples of the propylene-based copolymer include binary or ternary copolymers in which any amount of comonomer is combined, 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, and propylene-1-butene-1-octene copolymer.
Such a propylene-based copolymer (b) satisfies the condition of being a metallocene-based propylene-α-olefin random copolymer. The metallocene-based propylene-α-olefin random copolymer is a propylene-α-olefin random copolymer obtained by polymerization using a metallocene catalyst.

In addition, the propylene-based copolymer (b) used in the present invention preferably satisfies the following conditions (A-iv) to (A-v).
(A-iv) Metallocene-based propylene-ethylene random copolymer.
(Av) The melting peak temperature (Tm) is in the range of 126°C or higher and lower than 142°C.
The metallocene-based propylene-ethylene random copolymer is a propylene-based copolymer (b) obtained by polymerizing propylene as a main component and ethylene as an α-olefin using a metallocene catalyst.

(iii) MFR of propylene copolymer (b)
The melt flow rate (MFR: 230° C., 2.16 kg load) of the propylene-based copolymer (b) is in the range of 0.5 to 80 g/10 min.
When the melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene-based copolymer (b) used in the present invention is 0.5 g/10 min or more, molding is easy, and when it is 80 g/10 min or less, the relatively low molecular weight components in the propylene-based copolymer (b) are unlikely to bleed onto the surface of the molded product, resulting in a good appearance.
The melt flow rate (MFR) can be easily adjusted by adjusting the temperature and pressure, which are the polymerization conditions for the propylene-based copolymer (b), or by controlling the amount of hydrogen added in a method in which a chain transfer agent such as hydrogen is added during polymerization.

(iv) Tm of propylene copolymer (b)
The melting peak temperature (Tm) of the propylene-based copolymer (b) used in the present invention is 126°C or higher and lower than 142°C, preferably 128 to 141°C, more preferably 130 to 140°C. When the melting peak temperature (Tm) is 126°C or higher, the rigidity and moldability are good, and when it is lower than 142°C, the transparency 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 the sample is melted is taken as the melting peak temperature Tm (° C.).

(v) Content of Propylene-Based Copolymer (b) The propylene-based polymer composition of the present invention contains 26 to 87 parts by weight of the propylene-based (co)polymer (a), 3 to 25 parts by weight of the propylene-based copolymer (b), and 10 to 49 parts by weight of the biomass polyethylene (c), totaling 100 parts by weight. The propylene-based copolymer (b) is obtained by adding 3 to 25 parts by weight to 26 to 87 parts by weight of the propylene-based (co)polymer (a) and 10 to 49 parts by weight of the biomass polyethylene (c). However, the propylene-based polymer composition containing the propylene-based (co)polymer (a), the propylene-based copolymer (b), and the biomass polyethylene (c) is 100 parts by weight.
When the content of the propylene-based copolymer (b) is 3 parts by weight or more, the impact resistance is improved, and when it is 25 parts by weight or less, the rigidity is improved, which is preferable.

(vi) Method for producing propylene-based copolymer (b) There is no particular limitation on the method for producing the propylene-based copolymer (b), and any method for producing a propylene-based copolymer may be used. The catalyst used for the production is not particularly limited, but it is preferable to use a stereoregular catalyst. Examples of the stereoregular catalyst include Ziegler catalysts and metallocene catalysts. It is preferable to use a metallocene catalyst that is less likely to crack when containing biomass polyethylene (c). The metallocene catalyst is the same as that listed above.
As such a propylene-based copolymer (b), commercially available products can be used, such as those available from Exxon Mobil Corp. under the trade name of Vistamax, and those available from Japan Polypropylene Corp. under the trade names of WELNEX, WINTEC, and NOVATEC PP.

(3) Biomass polyethylene (c)
Plant-derived ethylene, which is a raw material monomer of the biomass polyethylene (c) used in the present invention, can be obtained by fermenting a plant raw material such as sugar cane with a microorganism to produce ethanol, and then heating the ethanol in the presence of a catalyst to cause an intramolecular dehydration reaction.
Biomass polyethylene (c) is a polymer obtained by polymerizing a monomer containing plant-derived ethylene as a main component. The raw material monomer of biomass polyethylene (c) does not have to contain 100% plant-derived ethylene. This is because the environmental load can be reduced by using plant-derived ethylene as a part of the monomer.
As the biomass polyethylene (c), a homopolymer obtained by homopolymerizing plant-derived ethylene or a copolymer obtained by copolymerizing plant-derived ethylene with an α-olefin can also be used. The number of carbon atoms of the α-olefin is not particularly limited, but 1-butene, 1-hexene, or 1-octene is preferable. Furthermore, petroleum-derived ethylene may be contained.

Examples of polyethylenes used as the biomass polyethylene (c) 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/ ^cm3 , and within this range, the rigidity is improved, which is preferable. The density of the medium density polyethylene is preferably 0.925 to 0.940 g/ ^cm3 , and within this range, the rigidity is improved, which is preferable.
Among the above polyethylenes, it is preferable to use at least one of low density polyethylene and linear low density polyethylene, which provides 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. When the density is 0.910 g/cm ³ or more, the rigidity is improved, which is preferable, and when the density is 0.920 g/cm ³ or less, the transparency improving effect is sufficient, which is preferable.
The density of the linear low density polyethylene is preferably 0.895 to 0.925 g/ ^cm3 , and more preferably 0.900 to 0.917 g/ ^cm3 . A density of 0.895 g/ ^cm3 or more is preferable because the rigidity is improved, and a density of 0.925 g/cm3 or ^less is preferable because the transparency improving effect is sufficient.

The ratio of plant-derived carbon to the total carbon amount in the biomass polyethylene (c) is called the bio-content, and can be determined by measuring the concentration of ¹⁴ C contained in the biomass polyethylene (c). That is, while a certain percentage of ¹⁴ C is contained in the atmosphere, the carbon of petroleum-derived resin does not contain ¹⁴ C, so the bio-content can be determined by measuring the concentration of ¹⁴ C contained in the biomass polyethylene (c). Specifically, when all the carbon in the biomass polyethylene (c) is derived from petroleum, the bio-content is 0%, and when all the carbon in the biomass polyethylene (c) is derived from plants, the bio-content is 100%. ASTM D6866 can be cited as a test method for measuring the concentration of ¹⁴ C.
The biomass polyethylene (c) 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).

The weight ratio of the biomass polyethylene (c) used in the propylene-based 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 effect of reducing the environmental load can be expected, and when it is 49 parts by weight or less, sufficient rigidity of the product can be obtained. (Here, a propylene-based polymer composition containing 26 to 87 parts by weight of the propylene-based (co)polymer (a), 3 to 25 parts by weight of the propylene-based copolymer (b), and 10 to 49 parts by weight of the biomass polyethylene (c) is 100 parts by weight.)
An example of such biomass polyethylene (c) is "Green PE" (product name manufactured by Braskem).

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

(5) Nucleating Agent The propylene polymer composition of the present invention may contain a nucleating agent in an amount of preferably 0.01 to 0.6 parts by weight 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 diterpene acids, or polymer nucleating agents.
Among them, it is particularly preferable to contain a nucleating agent represented by the following formula (1) in order to realize transparency.

・・・（１）
（式中、ｎは、０～２の整数であり、Ｒ^１～Ｒ^５は、それぞれ独立して、同一又は異なって、水素、ハロゲン、炭素数１～２０のアルキル、炭素数２～２０のアルケニル、炭素数１～２０のアルコキシ、炭素数１～２０のアルコキシカルボニル又はフェニルであり、Ｒ^６は、炭素数１～２０のアルキルである。）
式（１）で表される造核剤のうち、市販品として入手できる代表的なものは、ミラッドＮＸ８０００Ｊ（ミリケン・アンド・カンパニー社製）などが挙げられる。その化学構造式は、下記式（１－１）のとおりである。この造核剤の分子量は４８４である。この物質は、熱的・化学的にきわめて安定であるため、成形温度においてもほとんど熱分解しないという非常に優れた特徴がある。分解物が成形品の表面にブリードアウトして外観を悪化させるという問題が生じないため、非常に好ましい。

...(1)
(In the formula, n is an integer of 0 to 2, R ¹ to R ⁵ are each independently the same or different and are 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, and R ⁶ is alkyl having 1 to 20 carbon atoms.)
Among the nucleating agents represented by formula (1), a representative one that is commercially available is Milad NX8000J (manufactured by Milliken & Company). Its chemical structural formula is as shown in the following formula (1-1). The molecular weight of this nucleating agent is 484. This substance has the excellent characteristic of being extremely stable thermally and chemically, and therefore hardly undergoing thermal decomposition even at molding temperatures. This is highly preferable because there is no problem of decomposition products bleeding out onto the surface of the molded article and deteriorating the appearance.

・・・（１－１）

... (1-1)

The content of the nucleating agent represented by formula (1) contained in the propylene-based polymer composition of the present invention is preferably in the range of 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, based on 100 parts by weight of the propylene-based polymer composition. When the content of the nucleating agent represented by formula (1) is 0.1 parts by weight or more, it is expected that rigidity and transparency will be exhibited, and when it is 0.6 parts by weight or less, there is less concern about bleeding onto the surface of the molded article, and it is advantageous in terms of cost-effectiveness (cost performance) and elution in terms of rigidity and transparency.

(6) 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-based 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.

Examples of ultraviolet absorbers 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.

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 Examples of light stabilizers include 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.

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-di-methyl-phenyl)-3H-benzofuran-2-one, and vitamin E-based antioxidants such as those represented by the following formula (4).

・・・（２）

... (2)

・・・（３）

...(3)

・・・（４）

... (4)

Examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite (trade name: DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd., a magnesium aluminum complex hydroxide salt represented by the following formula (5)), and Mizukalac (trade name, manufactured by Mizusawa Chemical Industry Co., Ltd., a lithium aluminum complex hydroxide salt represented by the following formula (6)).
Mg _1-x Al _x (OH) ₂ (CO ₃ ) _x/2・mH ₂ O…(5)
[In the formula, x is 0<x≦0.5, and m is a number of 3 or less.]
[ _Al2Li (OH) ₆ ] _nX・_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.]

In addition, various known additives, such as antistatic agents, lubricants, dispersants such as fatty acid metal salts, dyes, pigments, etc., can be added to the composition as long as they do not impair the objectives of the present invention.

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 (co)polymer (a), the propylene-based polymer (b) and the biopolyethylene (c), 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 may be added to the propylene-based polymer composition in an amount of 1 to 30 parts by weight per 100 parts by weight of the propylene-based polymer composition. Similarly, it is also possible to blend elastomers such as natural rubber, butyl rubber, diene rubber, EPR, and EPDM. Furthermore, it is also possible to use general-purpose inorganic fillers such as talc, calcium carbonate, silica, alumina, gypsum, and mica in combination.

(7) Flexural Modulus of Propylene-Based Polymer Composition The flexural modulus of the propylene-based polymer composition used in the present invention is preferably in the range of 1000 to 1500 MPa, and when the flexural modulus is 1000 MPa or more, the mold releasability from a mold during injection molding is good, and when the flexural modulus is 1500 MPa or less, the impact resistance is good, more preferably 1100 to 1450 MPa, and further preferably 1200 to 1400 MPa.

(8) Charpy impact strength of propylene-based polymer composition The Charpy impact strength of the propylene-based polymer composition used in the present invention is preferably in the range of 3.0 kJ/ ^m2 or more, and when the Charpy impact strength is 3.0 kJ/ ^{m2 or more} , breakage of a molded article during transportation is suppressed. It is more preferably 3.5 kJ/m2 or more, and further preferably 4.0 kJ/m2 or ^more .

(9) Haze of Propylene Polymer Composition
The haze of the propylene polymer composition used in the present invention at a product thickness of 2 mmt is preferably in the range of 50% or less, and when the haze is 50% or less, the visibility of the contents is improved and the design is further improved, more preferably 45% or less, and further preferably 35% or less.

[2] Method for Producing Propylene-Based Polymer Composition The propylene-based polymer composition of the present invention can be obtained by mixing the propylene-based (co)polymer (a), the propylene-based copolymer (b), the biomass polyethylene (c), and other additives in predetermined amounts, as required, 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, twin-screw extruder, Banbury mixer, a plabender, a roll, or the like.

[3] Molded Articles Obtained Using Propylene-Based Polymer Composition To produce a molded article using the propylene-based polymer composition of the present invention, the propylene-based 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 range of applications, such as various industrial materials, automobile-related parts, various medical and cosmetic containers, daily necessities, films, and fibers.

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 (co)polymer (a), the propylene copolymer (b) and the propylene polymer composition were measured according to the following methods.
1. Measurement method

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

(2) Calculation of the ethylene content of the propylene (co)polymer (a) and the propylene copolymer (b)
The ethylene content in the random copolymer was measured by infrared spectroscopy using a characteristic absorption band at 733 cm ⁻¹ with an ethylene-propylene random copolymer, the composition of which was verified by ¹³ C-NMR, as a standard substance. The pellets were press-molded into a film having a thickness of about 500 μm.

(3) Measurement of molecular weight and molecular weight distribution:
The molecular weight distribution Mw/Mn of the propylene-based (co)polymer (a) and the propylene-based copolymer (b) 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 measurement 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°C
Flow rate: 1.0ml/min
Injection volume: 0.2ml

(4) Melting peak temperature (melting point) (Tm, unit: ° C.):
Using a differential scanning calorimeter (DSC), a sample of 5.0 mg was taken, and the temperature was once raised to 200° C. to erase the thermal history. After that, the sample was held at 200° C. for 5 minutes, and then the temperature was lowered to 40° C. at a temperature drop rate of 10° C./min to crystallize the sample. The temperature was then measured again at a temperature rise 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).

(5) Flexural modulus: Measured in accordance with JIS K7171.

(6) Charpy Impact Strength Charpy impact strength at 23° C. was measured in accordance with JIS K7111.
(7) Haze Value: Measured in accordance with JIS K7136 using a sheet piece having a thickness of 2 mm.

(8) Crack test in MD and TD Test pieces of 120 mm x 120 mm x 2 mm were injection molded (molding temperature: 200°C, mold temperature: 40°C), and a cut of about 3 cm in length was made with pruning shears to a width of 1.5 cm as shown in Figure 2. The cut parts were then bent by hand, and the cracks were evaluated according to the following criteria.
◎: Even if bent by 90 degrees or more, no splits (fissures, cracks) occur and the product does not separate into several parts (does not break).
○: Even when bent 90 degrees or more, a split (crack) occurs, but the piece does not separate into several pieces (does not split).
×: When bent more than 90 degrees, it separates into several parts (cracks).

<2. Resins and Additives>
2-1. Production of propylene (co)polymer (a) (1) Production Example 1
(i) Preparation of solid catalyst A 100-liter reactor equipped with an agitator, a thermometer, a jacket, and a cooling coil was charged with 30 mol of Mg(OEt) ₂ , and then Ti(OBu) ₄ was charged so that Ti(OBu) ₄ /Mg = 0.60 (m.r. (molar ratio)) was obtained with respect to the magnesium in the charged Mg(OEt) _2. Furthermore, 19.2 kg of toluene (TOL) was charged, and the temperature was raised while 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 MeSi(OPh) ₃ /Mg = 0.67 (m.r.) was obtained with respect to the magnesium in the charged Mg(OEt) _2. The amount of toluene used here was 7.8 kg. After the addition was completed, the mixture was reacted at 130° C. for 2 hours, then cooled to room temperature, and Si(OEt) ₄ was added. The amount of Si(OEt) ₄ added was adjusted so that the ratio of Si(OEt) ₄ /Mg was 0.056 (m.r.) relative to the magnesium in the Mg(OEt) ₂ previously charged.

Next, toluene was added to the obtained reaction mixture so that the magnesium concentration was 0.58 (mol/L-TOL). Furthermore, diethyl phthalate (DEP) was added so that DEP/Mg=0.10 (m.r.) was obtained relative to the magnesium in the Mg(OEt) ₂ previously charged. The obtained mixture was cooled to 10°C while continuing to stir, and TiCl ₄ was added dropwise over 2 hours to obtain a uniform solution. Note that TiCl 4 was adjusted so that TiCl ₄ /Mg=4.0 (m.r. ₎ was obtained relative to the magnesium in the Mg(OEt) ₂ previously charged. After the addition of TiCl ₄ was completed, the temperature was raised to 15°C at 0.5°C/min while stirring, and the temperature was maintained at the same temperature for 1 hour. Next, the temperature was raised again to 50°C at 0.5°C/min, and the temperature was maintained at the same temperature for 1 hour. Furthermore, the temperature was raised to 118°C at 1°C/min, and the treatment was performed at the same temperature for 1 hour. After the treatment was completed, the stirring was stopped, the supernatant liquid was removed, and the residue was washed with toluene to a residual liquid ratio of 1/73 (volume ratio of toluene/solid component) to obtain a slurry of the solid component.

Next, toluene and _TiCl4 were added to the slurry obtained here at room temperature. _TiCl4 was adjusted so that _TiCl4 /Mg(OEt) ₂ =5.0 (m.r.) with respect to the magnesium in Mg(OEt) ₂ previously charged. Toluene was adjusted so that the _TiCl4 concentration was 2.0 (mol/L-TOL). The slurry was heated while being stirred, 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 washed with toluene so that the residual liquid ratio was 1/150 (volume ratio of toluene/solid component), and a slurry of solid components was obtained.

(ii) Preparation of solid catalyst component (A) Of the solid components obtained in (i), 400 g was transferred to another reactor equipped with an agitator blade, a thermometer, and a 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 obtained 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 1 g of the solid components in the solid catalyst component (A). After the addition was completed, the mixture was kept at 15°C for 1 hour while continuing to stir, and was then heated 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 feeding was completed, stirring was stopped, the supernatant liquid was removed, and washing was carried out with normal hexane to obtain a slurry of solid catalyst component (A). The residual liquid rate was 1/12 (volume ratio of normal hexane/solid catalyst component (A)). The obtained solid catalyst component (A) had 12.0 g of propylene polymer per 1 g of solid catalyst component (A).

(iii) Production of propylene-ethylene copolymers Continuous production of propylene-ethylene copolymers was carried out by a process incorporating a degassing system consisting of a double ^- tube heat exchanger and a fluidized flash tank in the downstream of a liquid-phase polymerization tank with an internal volume of 0.4 m3 and equipped with a stirrer. Liquefied propylene, ethylene, hydrogen, TEA, and TBEDMS were continuously fed to the liquid-phase polymerization tank. TBEDMS represents t-butylethyldimethoxysilane, and t-butyl represents a 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, and hydrogen was fed to a gas phase concentration of 6.15 mol%, and ethylene was fed to a gas phase concentration of 0.74 mol%, respectively. Further, the solid catalyst component (A) obtained in (ii) above was fed so that the solid component contained in (A) was 0.13 g/hr. The liquid-phase polymerization tank was cooled so that the polymerization temperature was 70° C. The slurry polymerized in the liquid-phase polymerization tank was heated by a double-tube heat exchanger and discharged into a fluidized flash tank. The discharge rate of the slurry was adjusted so that the polypropylene particles contained in the slurry were about 24 kg/hr. The average residence time of the polypropylene particles in the liquid-phase polymerization tank was 1.4 hours. Analysis of the discharged polypropylene showed that the MFR was 25.0 g/10 min, the ethylene content was 0.7 wt%, the molecular weight distribution (Mw/Mn) was 5.7, and the Tm was 156° C.

(2) Production Example 2
(i) Preparation of solid catalyst 20 L of dehydrated and deoxygenated n-heptane was introduced into a 50 L tank equipped with a stirrer and thoroughly purged with nitrogen, followed by 10 moles of magnesium chloride (MgCl ₂ ) and 20 moles of tetrabutoxytitanium [Ti(O-n-C ₄ H ₉ ) ₄ ], and the reaction was carried out for 2 hours at 95° C. After completion of the reaction, the temperature was lowered to 40° C., and 12 L of methylhydrogenpolysiloxane [kinematic viscosity: 20 centistokes (cSt) = 2×10 ^-5 m ² /s] was introduced and the reaction was carried out for 3 hours. The produced solid component was washed with n-heptane.
Next, 5 L of n-heptane purified in the same manner as above was introduced into the tank equipped with a stirrer, and 3 moles of the solid component synthesized above were introduced in terms of Mg atom. Next, 5 moles of tetrachlorosilane (SiCl ₄ ) were mixed with 2.5 L of n-heptane, introduced into the flask at 30° C. for 30 minutes, and reacted at 70° C. for 3 hours. After the reaction was completed, the mixture was washed with n-heptane.
Next, 2.5 L of n-heptane was introduced into the tank equipped with a stirrer, and 0.3 mol of phthalic acid chloride was mixed and introduced at 70°C for 30 minutes, and reacted at 90°C for 1 hour. After the reaction was completed, the reaction mixture was washed with n-heptane. Then, 2 L of titanium tetrachloride (TiCl ₄ ) was introduced and reacted at 110°C for 3 hours. After the reaction was completed, the reaction mixture was washed with n-heptane to obtain a solid component (b1) for preparing a solid catalyst component (b). The titanium content of this solid component (b1) was 2.0% by weight.
Thereafter, 8 L of n-heptane, 400 g of the solid component (b1) synthesized above, and 0.6 _L of SiCl4 as component (b2) were introduced into the nitrogen-purged agitator-equipped vessel, and the reaction was carried out for 2 hours at 90° C. After completion of the reaction, 0.54 mol of vinyltrimethylsilane [(CH ₂ ═CH)Si(CH ₃ ) ₃ ] as component (b3), 0.27 mol of t-butylmethyldimethoxysilane [(t-C ₄ H ₉ )(CH ₃ )Si(OCH ₃ ) ₂ ] as component (b4), and 1.5 mol of triethylaluminum [Al(C ₂ H ₅ ) ₃ ] as component (a5) were further introduced in this order, and the mixture was contacted at 30° C. for 2 hours.
After the contact was completed, the mixture was thoroughly washed with n-heptane to obtain 390 g of a solid catalyst component (b) mainly composed of magnesium chloride. The titanium content of this solid catalyst component (b) was 1.8% by weight.

(ii) Prepolymerization Prepolymerization was carried out by the following procedure using the solid catalyst component (b) obtained above. Purified n-heptane was introduced into the above slurry to adjust the concentration of the solid catalyst component (b) to 20 g/L. After cooling the slurry to 10°C, 10 g of n-heptane diluted solution of Al(C ₂ H ₅ ) ₃ was added as Al(C ₂ H ₅ ) ₃ , and 210 g of propylene was supplied over 4 hours. After the supply of propylene was completed, the reaction was continued for another 30 minutes.
Next, the gas phase was thoroughly replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was taken out of the autoclave and vacuum dried to obtain a prepolymerized solid catalyst component (B). This solid catalyst component (B) contained 2.0 g of polypropylene per 1 g of solid catalyst component (B). Analysis showed that the portion of this solid catalyst component (B) excluding polypropylene contained 1.0 wt % Ti and 8.2 wt % (i-C ₃ H ₇ ) ₂ Si(OCH ₃ ) ₂ .

(iii) Production of propylene homopolymer Propylene polymerization was carried out using a fluidized bed reactor with an internal volume of 230 L as a continuous reactor. Propylene and hydrogen were continuously fed to the reactor so that the polymerization temperature was 85° C., the propylene partial pressure was 1.8 MPa (absolute pressure), and hydrogen as a molecular weight regulator was 0.010 in terms of the molar ratio of hydrogen/propylene. Furthermore, 5.25 g/hour of triethylaluminum and 0.50 g of the above-described prepolymerized solid catalyst component (B) were fed so that the propylene polymerization rate was 20 kg/hour, to produce a propylene homopolymer.
The powder polymerized in the reactor was continuously discharged into a vessel so that the amount of powder held in the reactor was 60 kg. Moisture-containing nitrogen gas was supplied to terminate the reaction, and a propylene homopolymer was obtained.
The MFR of this propylene homopolymer was 9 g/10 min.

2-2. Propylene-based (co)polymer (a)
(PP-1) Propylene-based resin obtained by polymerization in Production Example 1 (PP-2) Propylene-based resin obtained by polymerization in Production Example 2 2-3. Propylene-based copolymer other than propylene-based copolymer (b) (PP-3) Made by Japan Polypropylene Corporation, trade name "WINTEC WMG03", MFR = 30 g/10 min, ethylene content = 0.9 wt%, Tm = 142 ° C.
2-4. Propylene-based copolymer (b)
(PP-4) Japan Polypropylene Corporation, trade name "WINTEC WFW4M", MFR = 7.0 g/10 min, ethylene content = 1.9 wt%, Tm = 135°C
(PP-5) Trade name "NOVATEC PP MG03BD" manufactured by Japan Polypropylene Corporation, MFR = 30 g/10 min, ethylene content = 2.4 wt%, Tm = 152 ° C.

2-5. Biomass polyethylene (c)
Low Density Polyethylene (LDPE)
(PE-1) Product name “Green PE SPB608” manufactured by Braskem
Density: 0.915 g/cm ³ , melt flow rate according to ASTM D1238 (190°C, 2.16 kg load) is 30 g/10 min, bio content: 95% (all properties shown are values in the manufacturer's catalogue).
Linear low density polyethylene (LLDPE)
(PE-2) Product name “Green PE SLL118” manufactured by Braskem
Density: 0.916 g/cm ³ , melt flow rate according to ASTM D1238 (190°C, 2.16 kg load) is 1 g/10 min, bio content: 87% (all properties shown are values in the manufacturer's catalogue).
High density polyethylene (HDPE)
(PE-3) Braskem product name “Green PE SGM9450F”
Density: 0.952 g/cm ³ , melt flow rate according to ASTM D1238 (190°C, 5 kg load) is 0.33 g/10 min, bio content: 96% (all properties shown are values in the manufacturer's catalogue).

2-6. Other Additives (A-1) Hindered phenol-based antioxidant "IR1010"Tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxylphenyl)propionate]methane. Manufactured by BASF Japan Ltd., product name "IRGANOX1010".
(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".

<3. Examples 1 to 10 and Comparative Examples 1 to 9>
Each polymer and additive were prepared in the mixing ratio (parts by weight) shown in Table 1, dry-blended in a super mixer, and then melt-kneaded in a nitrogen atmosphere at a die outlet temperature of 220°C using a Toshiba Machine TEM-35B twin-screw extruder, and pelletized. The obtained pellets were used to measure physical properties. The evaluation results are shown in Table 1.

As is clear from Table 1, Examples 1 to 10 contain the specified amounts of the propylene-based (co)polymer (a), propylene-based copolymer (b) and biomass polyethylene (c) according to the present invention, and are materials that can reduce environmental loads, and are excellent in rigidity and do not crack. Example 1 contains a specified amount of LDPE as the biomass polyethylene (c), and is also excellent in transparency. Example 2 is the composition of Example 1 in which the content of the biomass polyethylene (c) LDPE is reduced, but is more excellent in rigidity and transparency than Example 1. Examples 3 and 4 use LLDPE and HDPE as the biomass polyethylene (c), respectively, and Examples 5 to 7 use propylene homopolymer as the propylene-based (co)polymer (a). Examples 8 to 9 increase or decrease the content of the propylene-based copolymer (b), and Example 10 uses a different propylene-based copolymer (b), but it can be confirmed that the effects of the present invention are obtained.
On the other hand, Comparative Examples 1 and 2 have a lower α-olefin content than the propylene-based copolymer (b) or do not contain the propylene-based copolymer (b), and although the rigidity is slightly better than that of Example 1, it is found that the cracking test in the TD direction cracks. Comparative Examples 3 and 4 are compositions containing PP-1 or PP-4 alone, but the biomass degree is 0%. Comparative Example 5 is a composition containing PE-1 alone, and the rigidity is insufficient. Comparative Example 6 has a low content of the propylene-based copolymer (b), so it cracks in the TD direction, and Comparative Example 9 has a high content of the propylene-based copolymer (b), so it is insufficient in rigidity. Comparative Example 7 has a low content of the biomass polyethylene (c), so the biomass degree is too low, and Comparative Example 8 does not use the propylene-based copolymer (b), so it is found that the cracking test in the TD direction cracks.

The propylene-based polymer composition of the present invention gives molded articles that are excellent in rigidity and do not crack even when they contain biomass polyethylene, and with a biomass content of 8.4 to 49%, it is useful for reducing the environmental load.

Claims (4)

A propylene-based polymer composition for injection molding contains 26 to 87 parts by weight of a propylene-based (co)polymer (a) satisfying the following conditions (Hi) to (H-ii), 3 to 25 parts by weight of a propylene- based copolymer (b) satisfying the following conditions (A-i) to (A-iii), and 10 to 49 parts by weight of a biomass polyethylene (c), totaling 100 parts by weight, and having a biomass degree of 8.4 to 49%.
(Hi) A propylene homopolymer or a propylene copolymer comprising propylene and an α-olefin in an amount of less than 1% by weight.
(H-ii) 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.
(Ai) Propylene-α-olefin random copolymer.
(A-ii) The α-olefin content is in the range of 1% by weight or more and less than 3% by weight.
(A-iii) The MFR is in the range of 0.5 to 80 g/10 min. The propylene-based polymer composition for injection molding according to claim 1, wherein the propylene-based copolymer (b) satisfies the following conditions (A-iv) to (A-v):
(A-iv) Metallocene-based propylene-ethylene random copolymer.
(Av) The melting peak temperature (Tm) is in the range of 126°C or higher and lower than 142°C. 3. A propylene-based polymer composition for injection molding, comprising 0.01 to 0.6 parts by weight of a nucleating agent based on 100 parts by weight of the propylene-based polymer composition for injection molding according to claim 1 or 2. A molded article obtained by using the propylene polymer composition for injection molding according to any one of claims 1 to 3.

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