JP6707967B2 - Injection molded article using polypropylene-based resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an injection-molded article using a polypropylene-based resin composition, and more particularly, to an injection-molded article using a polypropylene-based resin composition having excellent impact resistance, rigidity, transparency and moldability.

Polypropylene is lightweight and excellent in mechanical strength and the like. In particular, a propylene-ethylene block copolymer is inferior in transparency, but it has an excellent balance of impact resistance and rigidity. Widely used in various fields such as food packaging containers.

Further, the propylene-ethylene random copolymer is inferior in impact resistance, but is excellent in transparency and heat sealability, and is used for dessert cups, films and the like.
In recent years, polypropylene having both rigidity, impact resistance, and transparency has been demanded, and JP-A-2006-161033 (Patent Document 1) discloses polypropylene and ethylene-α-olefin copolyester for packaging retort foods. Compositions in which a combination is used are described.

JP, 2006-161033, A

The object (problem) of the present invention relates to an injection molded article using a polypropylene resin composition, and more specifically, an injection molded article using a polypropylene resin composition excellent in impact resistance, rigidity, transparency and moldability. To provide.

The present inventor has conducted extensive studies to solve the above-mentioned problems, and as a result, by using a polypropylene-based resin composed of a specific propylene-ethylene block copolymer and an ethylene-based polymer, rigidity, impact resistance, and transparency. Further, they have found that an injection-molded article having an excellent balance of moldability can be obtained, and completed the present invention.
The present invention provides an injection molded article using the following polypropylene resin composition.

That is, according to the first aspect of the present invention, there is provided an injection-molded article made of the polypropylene resin composition (X), wherein the polypropylene resin composition (X) is characterized by the following. is there.
The polypropylene resin composition (X) is
75-85 wt% of a propylene-based homopolymer (A) having a melt flow rate (MFR) of 3.5-300 g/10 minutes according to JIS K7210 (230°C, 2.16 kg load), the following (B1)- Propylene-ethylene copolymer (B) satisfying (B2) is contained in 15 to 25 wt% (provided that the total of propylene homopolymer (A) and propylene-ethylene copolymer (B) is 100 wt%) Propylene -Ethylene block copolymer component (a) 83 to 88 wt%, 12 to 17 wt% of ethylene-based polymer (C) satisfying the following (C1) to (C3) (however, propylene-ethylene block copolymer 100 wt% of the total of the component (a) and the ethylene-based polymer (C)) is included;
(B1) The ethylene content is 20 to 35 wt% (however, based on 100 wt% of the total weight of the propylene-ethylene copolymer (B)).
(B2) The intrinsic viscosity [η]B measured in 135° C. o-dichlorobenzene is 2.0 to 3.0 dl/g.
(C1) The density is 0.905 to 0.920 g/cm ³ .
(C2) The melting point is 100° C. or higher.
(C3) MFR based on JIS K6922-2 (190°C, 2.16 kg load) is 10 to 50 g/10 minutes.
In addition, the polypropylene resin composition (X) has an MFR of 5 to 100 g/10 minutes according to JIS K7210 (230°C, 2.16 kg load).

Further, according to the second invention of the present invention, from the polypropylene resin composition (X) according to the first invention, the HAZE having a molded body thickness of 1 mmt according to JIS K7136 (ISO14782) is 35% or less. The following injection molded article is provided.
Furthermore, according to the third invention of the present invention, the polypropylene according to any one of the first and ^second inventions, wherein the Charpy impact strength at 0° C. according to JIS K7111 (ISO179) is 2.5 kJ/m ² or more. Provided is an injection-molded article made of the resin composition (X).
Further, according to the fourth aspect of the present invention, the polypropylene resin composition (X) according to any one of the first to third aspects of the invention has a flexural modulus according to JIS K7171 (ISO178) of 950 MPa or more. The following injection molded article is provided.
Furthermore, according to the 5th invention of the present invention, the polypropylene-based resin composition (X) according to any one of the 1st to 4th inventions, wherein the molded body has a thickness of 0.3 to 1.0 mmt. An injection molded body is provided.
Furthermore, according to a sixth aspect of the present invention, there is provided a food packaging container comprising the injection-molded article according to any one of the first to fifth aspects.

An injection-molded article using the polypropylene resin composition of the present invention has an excellent balance of rigidity, impact resistance, transparency and moldability.

Hereinafter, embodiments of the present invention will be described in detail, but the description of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

The injection-molded article of the present invention is an injection-molded article composed of the polypropylene resin composition (X), and is characterized by the following.
The polypropylene resin composition (X) is
75-85 wt% of a propylene-based homopolymer (A) having a melt flow rate (MFR) of 3.5-300 g/10 minutes according to JIS K7210 (230°C, 2.16 kg load), the following (B1)- Propylene-ethylene copolymer (B) satisfying (B2) is contained in 15 to 25 wt% (provided that the total of the propylene homopolymer (A) and the propylene-ethylene copolymer (B) is 100 wt%) Propylene -Ethylene block copolymer component (A) 83 to 88 wt%, 12 to 17 wt% of the ethylene-based polymer C satisfying the following (C1) to (C3) (however, propylene-ethylene block copolymer component ( A) and the ethylene-based polymer (C) in 100 wt%));
(B1) The ethylene content is 20 to 35 wt% (based on the total weight of the propylene-ethylene copolymer (B) of 100 wt%).
(B2) The intrinsic viscosity [η]B measured in 135° C. o-dichlorobenzene is 2.0 to 3.0 dl/g.
(C1) The density is 0.905 to 0.920 g/cm ³ .
(C2) The melting point is 100° C. or higher.
(C3) MFR based on JIS K6922-2 (190°C, 2.16 kg load) is 10 to 50 g/10 minutes.
The polypropylene resin composition (X) has an MFR of 5 to 100 g/10 minutes according to JIS K7210 (230°C, 2.16 kg load).

[Propylene-ethylene block copolymer component (a)]
The propylene-ethylene block copolymer component (A) used in the present invention contains 75 to 85 wt% of the propylene homopolymer (A) described below and 15 to 25 wt% of the propylene-ethylene copolymer (B) described below. (However, the total of the propylene homopolymer (A) and the propylene-ethylene copolymer (B) is 100 wt%).
Further, the propylene-ethylene block copolymer component (A) needs to be in the range of 83 to 88 wt% in 100 wt% of the polypropylene resin composition (X), preferably 83 to 87 wt %. It is preferably 83 to 86 wt %.

[Propylene-based homopolymer (A)]
The propylene homopolymer (A) used in the present invention needs to be in the range of 75 to 85 wt% in 100 wt% of the propylene-ethylene block copolymer component (a), preferably 77 to 84 wt. %, and more preferably 78 to 83 wt %.
The propylene homopolymer (A) used in the present invention has a melt flow rate (MFR) according to JIS K7210 (230° C., 2.16 kg load) of 3.5 to 300 g/10 minutes. It is necessary, preferably 10 to 200 g/10 minutes, more preferably 30 to 100 g/10 minutes. When the MRF is 3.5 g/10 min or more, the fluidity at the time of injection molding can be sufficiently secured, and a desired injection molded product can be obtained. On the other hand, when the MRF is 300 g/10 minutes or less, sufficient impact resistance can be obtained.

[Propylene-ethylene copolymer (B)]
The propylene-ethylene copolymer (B) used in the present invention needs to be in the range of 15 to 25 wt% in 100 wt% of the propylene-ethylene block copolymer component (a), preferably 16 to 23 wt%, and more preferably 17 to 22 wt%. When the content of the propylene-ethylene copolymer (B) is 15 wt% or more, sufficient impact resistance can be obtained. On the other hand, when the content of the propylene-ethylene copolymer (B) is 25 wt% or less, sufficient rigidity and transparency can be obtained.

In addition, the propylene-ethylene copolymer (B) satisfies the characteristics (B1) to (B2) as described above.
(B1): The ethylene content in the propylene-ethylene copolymer (B) needs to be in the range of 20 to 35 wt% based on 100 wt% of the total weight of the propylene-ethylene copolymer (B). %, preferably 22 to 33 wt %, and more preferably 25 to 30 wt %. When the ethylene content is 20 wt% or more, sufficient impact resistance can be obtained. On the other hand, if it is 35 wt% or less, sufficient transparency can be obtained.
(B2): The intrinsic viscosity [η]B of the propylene-ethylene copolymer (B) measured in ortho-dichlorobenzene (o-dichlorobenzene) at 135° C. is 2.0 to 3.0 dl/g. The range is preferably 2.0 to 2.8 dl/g, more preferably 2.2 to 2.8 dl/g. When the intrinsic viscosity [η]B is 2.0 dl/g or more, sufficient impact resistance can be obtained. On the other hand, if it is 3.0 dl/g or less, sufficient transparency can be obtained.
The intrinsic viscosity [η]B was determined by dissolving the propylene-ethylene block copolymer component (a) in p-xylene at 130°C to form a solution, and then leaving it at 25°C for 12 hours to separate the precipitated polymer by filtration. Then, after evaporating p-xylene from the filtrate to obtain a propylene-ethylene copolymer (B), it can be measured using orthodichlorobenzene as a solvent at a temperature of 135° C. using an Ubbelohde viscometer.

[Ethylene-based polymer (C)]
The ethylene polymer (C) used in the present invention needs to be in the range of 12 to 17 wt% in 100 wt% of the polypropylene resin composition (X), preferably 13 to 17 wt %, and further preferably Is 14 to 17 wt %. When the content of the ethylene polymer (C) is 12 wt% or more, sufficient impact resistance and transparency can be obtained. On the other hand, if it is 17 wt% or less, sufficient moldability can be obtained.

Further, the ethylene polymer (C) satisfies the above-mentioned characteristics (C1) to (C3).
(C1): The density of the ethylene polymer (C), must be 0.905~0.920g / cm ^3, preferably 0.907~0.920g / cm ^3, more preferably 0. It is 910 to 0.918 g/cm ³ . If the density of the ethylene polymer (C) is within this range, sufficient transparency can be obtained. The density is a value measured by the D method (density density tube method) according to JIS K7112.
(C2): The melting point of the ethylene polymer (C) needs to be in the range of 100°C or higher, preferably 102°C or higher, and more preferably 105°C or higher. When the melting point of the ethylene-based polymer (C) is 100° C. or higher, releasability during injection molding is ensured and continuous moldability is excellent. The upper limit of the melting point of the ethylene polymer (C) is not particularly limited, but it is usually preferably 125°C or lower.
Here, a specific measurement of the melting point was performed by using a differential scanning calorimeter (DSC), a sample amount of 5 mg was taken, and the sample was held at 200° C. for 5 minutes and then crystallized to 40° C. at a temperature decrease rate of 10° C./min. Further, the peak position of the curve drawn when melting at a temperature rising rate of 10° C./min is defined as the melting peak temperature (melting point) Tm (° C.).
(C3): Regarding the ethylene polymer (C), the MFR according to JIS K6922-2 (190°C, 2.16 kg load) needs to be in the range of 10 to 50 g/10 minutes, preferably 15 ~45 g/10 minutes, more preferably 17-40 g/10 minutes. When the MFR of the ethylene polymer (C) is 10 g/10 minutes or more, it is possible to sufficiently secure the fluidity during injection moldability. On the other hand, when it is 50 g/10 minutes or less, bleed-out on the surface of the molded product can be suppressed and transparency is improved.

The ethylene polymer (C) used in the polypropylene resin composition of the present invention is preferably an ethylene elastomer. Specific examples thereof include ethylene homopolymers and ethylene-α-olefin random copolymers, but they may be used alone or in combination of two or more within a range that does not impair the effects of the present invention. Here, as α-olefins other than ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene-1 and the like can be mentioned. In the case of a copolymer of ethylene and another α-olefin, the amount of ethylene units is preferably 70 to 99% by weight.
Such ethylene-α-olefin random copolymers are commercially available products such as Novatec LL series, Harmolex series, Kernel series manufactured by Nippon Polyethylene Co., Ltd., Tuffmer P series and Tuffmer A series manufactured by Mitsui Chemicals, Inc. , EVOLUE series manufactured by Prime Polymer Co., Ltd., Sumikasen E, EP series manufactured by Sumitomo Chemical Co., Ltd., and Excellen GMH series.

[Polypropylene resin composition (X)]
The polypropylene resin composition (X) used in the present invention contains propylene-ethylene block copolymer component (A) 83 to 88 wt% and ethylene polymer (C) 12 to 17 wt% (however, propylene- The total of the ethylene block copolymer component (A) and the ethylene polymer (C) is 100 wt %).
The polypropylene resin composition (X) used in the present invention needs to have a melt flow rate (MFR) according to JIS K7210 (230° C., 2.16 kg load) in the range of 5 to 100 g/10 minutes. It is preferably 10 to 90 g/10 minutes, more preferably 20 to 80 g/10 minutes. When the MFR is 5 g/10 minutes or more, the fluidity at the time of injection molding can be sufficiently secured, and a desired injection molded product can be obtained. On the other hand, if it is 100 g/10 minutes or less, sufficient impact resistance can be obtained.

Further, the polypropylene resin composition (X) preferably has a Haze of 35% or less for a molded body having a thickness of 1 mmt according to JIS K7136 (ISO14782). When the Haze is 35% or less, sufficient visibility of the content can be obtained. The lower limit of HAZE having a thickness of 1 mmt is not particularly limited, but is preferably 20% or more.

Further, the polypropylene resin composition (X) preferably has a Charpy impact strength of 2.5 kJ/m ² or more at 0° C. according to JIS K7111 (ISO179). When the Charpy impact strength is 2.5 kJ/m ² or more, it is less likely to be damaged during transportation in a refrigerating environment. The upper limit of the Charpy impact strength at 0° C. is not particularly limited, but it is preferably 6.0 kJ/m ² or less.

Further, the polypropylene resin composition (X) preferably has a flexural modulus of 950 MPa or more according to JIS K7171 (ISO178). When the flexural modulus is 950 MPa or more, the molded product is less likely to be deformed when it is pressed during transportation, and the mold releasability during injection molding is excellent. Although not particularly limited, the bending elastic modulus is preferably in the range of 1300 MPa or less.

[Injection molding (injection molding)]
The injection-molded article of the present invention comprises the polypropylene resin composition (X), and the thickness of the molded article is preferably in the range of 0.3 to 1.0 mmt, more preferably 0.3 to 0 mm. 0.7 mmt, more preferably 0.3 to 0.5 mmt. When the thickness of the injection-molded product is 0.3 mmt or more, the rigidity of the injection-molded product can be sufficiently ensured and the releasability is excellent. On the other hand, if it is 1.0 mmt or less, sufficient transparency can be obtained.

The ratio of the propylene homopolymer (A) and the propylene-ethylene copolymer (B) and the ethylene content are measured by the CFC-IR method. The method is as follows.

(I) Analyzing device used (a) Cross sorting device Dia Instruments Co., Ltd. CFC T-100 (abbreviated as CFC)
(A) Fourier transform infrared absorption spectrum analysis FT-IR, Perkin Elmer 1760X
The fixed wavelength infrared spectrophotometer attached as the CFC detector is removed, and FT-IR is connected instead, and this FT-IR is used as the detector.
The transfer line from the outlet of the solution eluted from the CFC to the FT-IR has a length of 1 m and is maintained at a temperature of 140° C. throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1 mm and an optical path width of 5 mmφ and is maintained at a temperature of 140° C. throughout the measurement.
(C) Gel permeation chromatography (GPC)
The GPC column in the latter part of the CFC is used by connecting three AD806MS manufactured by Showa Denko KK in series.

(Ii) CFC measurement conditions (a) Solvent: Orthodichlorobenzene (ODCB)
(A) Sample concentration: 4 mg/ml
(C) Injection volume: 0.4 ml
(D) Crystallization: The temperature is lowered from 140° C. to 40° C. over about 40 minutes.
(E) Separation method:
The fractionation temperature at the elevated temperature elution fractionation is 40° C., 100° C., 140° C., and fractionation is performed into three fractions in total.
In addition, the elution ratio (unit:% by weight) of the component eluting at 40° C. or lower (fraction 1), the component eluting at 40 to 100° C. (fraction 2), and the component eluting at 100 to 140° C. (fraction 3), respectively, It is defined as W40, W100, and W140. W40+W100+W140=100. The separated fractions are automatically transported to the FT-IR analyzer as they are.
(F) Solvent flow rate during elution: 1 ml/min

(Iii) FT-IR measurement conditions After the elution of the sample solution from GPC at the latter stage of CFC, FT-IR measurement is performed under the following conditions, and GPC-IR data is collected for each of the above-mentioned fractions 1 to 3. ..
(A) Detector: MCT
(A) Resolution: 8 cm ^-1
(C) Measurement interval: 0.2 minutes (12 seconds)
(D) Number of integrations per measurement: 15 times

(Iv) Post-treatment and analysis of measurement results The elution amount and molecular weight distribution of the components eluted at each temperature are determined by using the absorbance at 2945 cm ⁻¹ obtained by FT-IR as a chromatogram. The elution amount is standardized so that the total elution amount of each elution component is 100%. The conversion from the retention capacity to the molecular weight is performed using a calibration curve prepared in advance using standard polystyrene.
The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.
A calibration curve is prepared by injecting 0.4 ml of a solution dissolved in ODCB (containing 0.5 mg/ml BHT) so that each of them will be 0.5 mg/ml. For the calibration curve, a cubic expression obtained by approximation by the least square method is used.
For the conversion to the molecular weight, a general-purpose calibration curve is used with reference to “Size Exclusion Chromatography” by Sadao Mori (Kyoritsu Shuppan). The following numerical values are used for the viscosity formula ([η]=K×M ^α ) used at that time.
(A) When creating a calibration curve using standard polystyrene K=0.000138, α=0.70
(A) At the time of measuring a sample of propylene-based block copolymer K=0.00103, α=0.78
The molecular weights of the eluate fractions separated by elution are defined as Mw(40), Mw(100) and Mw(140). The overall molecular weight distribution was calculated by summing the data obtained by the three fractions. From this, the content (% by weight) of the component having a weight average molecular weight of 3,000 or less, which will be described later, can be determined by integrating.
The ethylene content distribution (distribution of ethylene content along the molecular weight axis) of each eluted component was calculated by using the ratio between the absorbance at 2956 cm ⁻¹ and the absorbance at 2927 cm ⁻¹ obtained by FT-IR, using polyethylene, polypropylene or ¹³ Using ethylene-propylene rubber (EPR) and a mixture thereof whose ethylene content is already known by C-NMR measurement and the like, converted to ethylene content (wt%) by a calibration curve prepared in advance. Ask for.

The ratio (Wc) of the propylene-ethylene copolymer (B) part in the propylene-ethylene block copolymer component (A) in the present invention is calculated by the method described above, and is calculated by the following formula (I). The above is defined and determined by the following procedure.
Wc (% by weight)=W40×A40/B40+W100×A100/B100...(I)

In the formula (I), W40 and W100 are the elution ratios (unit: wt %) in each of the above-mentioned fractions, and A40 and A100 are the average ethylene content of the actual measurement in each fraction corresponding to W40 and W100 ( (Unit: wt %), and B40 and B100 are ethylene contents (unit: wt %) of (B) contained in each fraction. The method of obtaining A40, A100, B40, B100 will be described later.
The meaning of formula (I) is as follows. That is, the first term on the right side of the formula (I) is a term for calculating the amount of (A) contained in the fraction 1 (portion soluble at 40° C.). When Fraction 1 contains only (B) and does not contain (A), W40 contributes to the content of (B) derived from Fraction 1 as it is in the whole, but Fraction 1 contains (B) Since a small amount of the component derived from (A) (a component having an extremely low molecular weight) is contained in addition to the component derived, it is necessary to correct that portion. Therefore, the amount derived from the component (B) in the fraction 1 is calculated by multiplying W40 by A40/B40. For example, when the average ethylene content (A40) of fraction 1 is 15% by weight and the ethylene content (B40) of (B) contained in fraction 1 is 20% by weight, 15/20 of fraction 1=3/4 (That is, 75% by weight) is derived from (B) and 1/4 is derived from (A). Thus, the operation of multiplying A40/B40 by the first term on the right side means calculating the contribution of (B) from the weight% (W40) of the fraction 1.

Here, the calculation is performed in consideration of the following conditions.
(A) As described above, the average ethylene contents corresponding to the fractions 1 and 2 obtained by CFC measurement are A40 and A100, respectively (the unit is% by weight). The method for obtaining the average ethylene content will be described later.
(A) Let B40 be the ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 (unit is% by weight).
Regarding the fraction 2, it is considered that the rubber portion is completely eluted at 40° C. and cannot be defined by the same definition. Therefore, in the present invention, it is substantially defined as B100=100.
B40 and B100 are ethylene contents of (B) contained in each fraction, but it is practically impossible to analytically determine this value. The reason is that there is no means for completely separating and separating (A) and (B) mixed in the fraction. As a result of studies using various model samples, B40 can successfully explain the effect of improving the physical properties of the material by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. That is, B40 is the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. In addition, B100 has crystallinity derived from an ethylene chain, and the amount of (A) contained in these fractions is relatively smaller than the amount of (A) contained in fraction 1. For the reason above, the value closer to 100 is closer to the actual condition and there is almost no error in calculation. Therefore, analysis is performed with B100=100.

(C) For the above reason, the ratio (Wc) is calculated according to the following formula (II).
Wc (% by weight)=W40×A40/B40+W100×A100/100 (II)
That is, W40×A40/B40, which is the first term on the right side of the formula (II), represents the content (% by weight) without crystallinity (B), and W100×A100/100, which is the second term, is a crystal (A) content (% by weight) having properties is shown.
Here, the average ethylene contents A40 and A100 of the respective fractions 1 and 2 obtained by B40 and CFC measurement are determined as follows.
The ethylene content corresponding to the peak position of the differential molecular weight distribution curve is defined as B40. In addition, the sum of the products of the weight ratio of each data point and the ethylene content of each data point, which is taken in as data points at the time of measurement, is defined as the average ethylene content A40 of fraction 1. The average ethylene content A100 of fraction 2 is also determined in the same manner.

The significance of setting the above three types of separation temperatures is as follows.
In the CFC analysis of the present invention, 40° C. is necessary and sufficient to separate only polymers having no crystallinity (for example, most of (B) or components of (A) having extremely low molecular weight). It has the significance of being stable temperature conditions. 100° C. means a component that is insoluble at 40° C. but is soluble at 100° C. (for example, a component having crystallinity due to a chain of ethylene and/or propylene in (B), and low crystallinity) It is a temperature that is necessary and sufficient to elute only (A)). 140° C. means a component which is insoluble at 100° C. but soluble at 140° C. (for example, a component having particularly high crystallinity in (A), and extremely high molecular weight and extremely high ethylene in (B)). The temperature is sufficient to elute only the component having crystallinity) and to recover the total amount of the propylene-ethylene block copolymer component (a) used for analysis.
It should be noted that W140 does not contain the component (B) at all, or even if it exists, it is an extremely small amount and can be substantially ignored, so it is excluded from the calculation of the ratio of (B) and the ethylene content of (B). To do.

The catalyst used for obtaining the propylene homopolymer (A) and the propylene-ethylene copolymer (B) used in the present invention is not particularly limited, and a known catalyst can be used.
For example, a so-called Ziegler-Natta catalyst or a metallocene catalyst, which is a combination of a titanium compound and organic aluminum, can be used (for example, described in JP-A-5-295022).
In the present invention, since a propylene block copolymer having a good balance of rigidity and impact resistance is particularly preferable, a Ziegler-Natta catalyst having a high stereoregularity is more preferable.

Regarding the production process of the propylene homopolymer (A) and the propylene-ethylene copolymer (B), any method may be used as long as the above-mentioned various properties are satisfied, but from the viewpoint of economy, it is a gas phase method. The process is preferable, and among them, it is more preferable to produce it by a process having a horizontal reactor having a stirrer rotating around a horizontal axis in the form of removing the heat of polymerization by utilizing latent heat of vaporization of liquefied propylene.
Further, the propylene homopolymer (A) and the propylene-ethylene copolymer (B) may be mixed by any method as long as the above-mentioned properties are satisfied, but a two-stage continuous polymerization method. By adopting, the dispersion of the propylene-ethylene copolymer (B) in the propylene homopolymer (A) becomes good, and the transparency is further improved.
The propylene homopolymer (A) and the propylene-ethylene copolymer (B) may be used either individually or in combination of two or more.

[Nucleating agent]
By including the nucleating agent in the polypropylene resin composition (X) used in the present invention, a molded article having better transparency can be obtained.
As the nucleating agent, an organic phosphoric acid ester metal salt, an organic monocarboxylic acid metal salt, an organic dicarboxylic acid metal salt, a polymer nucleating agent, dibenzylidene sorbitol or a derivative thereof, a diterpene acid metal salt, and the like are used.

Examples of the organic phosphoric acid ester metal salt include sodium-2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate and sodium-2,2'-ethylidene-bis(4,6). -Di-t-butylphenyl)phosphate, lithium-2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate, lithium-2,2'-ethylidene-bis(4,6) -Di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis(4-i-propyl-6-t-butylphenyl)phosphate, lithium-2,2'-methylene-bis(4 -Methyl-6-t-butylphenyl)phosphate, lithium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate, sodium-2,2'-butylidene-bis(4 ,6-Di-methylphenyl)phosphate, sodium-2,2'-butylidene-bis(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-t-octylmethylene-bis( 4,6-Di-methylphenyl)phosphate, sodium-2,2'-t-octylmethylene-bis(4,6-di-t-butylphenyl)phosphate, calcium-bis[(2,2'- Methylene-bis(4,6-di-t-butylphenyl)phosphate], magnesium-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], barium-bis [2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], sodium-2,2'-methylene-bis(4-methyl-6-t-butylphenyl)phosphate, Sodium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis(4-s-butyl-6-t-butylphenyl)phosphate Fate, sodium-2,2'-methylene-bis(4,6-di-methylphenyl)phosphate, sodium-2,2'-methylene-bis(4,6-di-ethylphenyl)phosphate, potassium- 2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate, calcium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate], Magnesium-bis[2,2'-ethylidene-bis(4,6-di-t-butyl) Ruphenyl)phosphate], barium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate], aluminum-tris[2,2'-methylene-bis(4,6) -Di-t-butylfel)phosphate], aluminum-tris[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate], aluminum hydroxy-bis[2,2'- Methylene-bis(4,6-di-t-butylphenyl)phosphate], aluminum dihydrooxy-2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate, and the like. ..

The organic monocarboxylic acid metal salt is, for example, a salt of a metal such as benzoic acid, allyl-substituted acetic acid, and the like. Specifically, benzoic acid, p-isopropylbenzoic acid, o-tertiary butylbenzoic acid, Examples thereof include p-t-butylbenzoic acid, monophenylacetic acid, diphenylacetic acid, phenyldimethylacetic acid, and their Li, Na, Mg, Ca, Ba, and Al salts. Examples of the organic dicarboxylic acid metal salt include, for example, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, phthalic acid, cyclohexanecarboxylic acid, norbornanedicarboxylic acid and their Li, Na, Mg, Ca, Ba and Al. Examples thereof include salt. Examples of the polymer nucleating agent include polyvinyl cyclohexane and poly-3-methyl-butene-1.

Examples of the dibenzylidene sorbitol or a derivative thereof include 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene sorbitol, and 1,3-benzylidene-2,4- p-Ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-methylbenzylidene-2,4 -P-ethylbenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di(p-methylbenzylidene)sorbitol, 1,3,2,4 -Di(p-ethylbenzylidene)sorbitol, 1,3,2,4-di(pn-propylbenzylidene)sorbitol, 1,3,2,4-di(pi-propylbenzylidene)sorbitol, 1, 3,2,4-di(pn-butylbenzylidene)sorbitol, 1,3,2,4-di(ps-butylbenzylidene)sorbitol, 1,3,2,4-di(pt-) Butylbenzylidene)sorbitol, 1,3,2,4-di(p-methoxybenzylidene)sorbitol, 1,3,2,4-di(p-ethoxybenzylidene)sorbitol, 1,3-benzylidene-2,4-p -Chlorobenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-benzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3-p-chlorobenzylidene-2 ,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3 , 2,4-di(p-chlorobenzylidene)sorbitol, 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol and the like. You can Particularly preferably, 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di(p-methylbenzylidene)sorbitol, 1,3-p-chlorobenzylidene-2,4-p-methylbenzylidene Examples thereof include sorbitol, 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol and the like.

The metal salt of diterpene acids is a reaction product of a diterpene acid and a predetermined metal compound such as a magnesium compound and an aluminum compound. Diterpenic acid is generally known as a natural resin obtained from Pinaceae plants, specifically, natural rosins such as gum rosin, tall oil rosin and wood rosin; disproportionated rosin, hydrogenated rosin and dehydrogenation. Various modified rosins such as rosin, polymerized rosin, and rosin modified with α,β-ethylenically unsaturated carboxylic acid; and natural rosin and purified products of modified rosin are used as raw materials. Examples of the diterpene acids include pimaric acid, sandaracopimaric acid, parastophosphoric acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, dihydropimaric acid, dihydroabietic acid, tetrahydroabietic acid and the like.

Among these, preferable nucleating agents are organic phosphoric acid ester metal salts and organic dicarboxylic acid metal salts, and more preferably sodium-2,2′-methylene-bis(4,6-di-t-butylphenyl). Phosphate, sodium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate, aluminum-tris[2,2'-methylene-bis(4,6-di-t-butylphenyl) ) Phosphate], aluminum hydroxy-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], aluminum dihydroxy-2,2'-methylene-bis(4,4). Phosphoric acid ester metal salt having a cross-linked substituted aromatic group such as 6-di-t-butylphenyl)phosphate, or sodium 2-cyclohexanedicarboxylate, sodium 1,2-norbornane dicarboxylate, 1,2-norbornane Examples include alicyclic hydrocarbon dicarboxylic acid metal salts such as magnesium dicarboxylate. Examples of the metal salt include lithium, sodium, potassium, calcium, magnesium, aluminum salts and the like, and Group 1 metals such as lithium, sodium and potassium are more preferable.
The content of the nucleating agent is preferably 0.01 to 0.7 parts by weight, more preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the polypropylene resin composition (X). is there. When the content of the nucleating agent is 0.01 part by weight or more, the transparency improving effect is sufficient, while when it is 0.7 part by weight or less, the cost-effectiveness (cost/performance) point Is advantageous.
In addition, you may use these nucleating agents in combination of 2 or more types.

[Other additives]
The polypropylene resin composition (X) used in the present invention contains various additives such as a heat stabilizer, an antioxidant, a weather stabilizer, an ultraviolet absorber, and a copper damage preventive agent as long as the performance is not impaired. Agents, antistatic agents, flame retardants, hydrophilic agents, slip agents, antiblocking agents, antifog agents, colorants, fillers, polyethylene, elastomers, petroleum resins, antibacterial agents and the like.
Further, when MFR adjustment is necessary, an organic peroxide can be blended.

[Method for producing polypropylene resin composition (X)]
The polypropylene resin composition (X) of the present invention contains various components such as the above-mentioned propylene-ethylene block copolymer component (a), ethylene polymer (C) and, if necessary, a nucleating agent and other additives. The predetermined amounts of the components can be obtained by mixing using a normal mixing device such as a Henschel mixer (trade name), a super mixer, a ribbon blender, a tumbler mixer, a Banbury mixer, or the like. Pelletizing the obtained mixture at a melt-kneading temperature of 150 to 300° C., preferably 180 to 250° C. by using a single-screw or twin-screw extruder, a roll, or the like to obtain a pelletized composition. You can also

[Injection molded product]
The injection-molded article (injection-molded article) of the present invention is obtained by subjecting the above polypropylene-based resin composition (X) to ordinary injection molding, injection compression molding, injection foam molding, injection stretch blow molding, and the like. can get.
As the injection molded product, specifically, a food container (pudding container, jelly container, yogurt container, other dessert container, side dish container, steamed egg container, container for instant food such as instant noodles such as instant noodles, etc. , Cooked rice container, retort container, bento container, etc.), beverage container (beverage bottle, chilled coffee container, one-hand cup container, other beverage container, etc.), cap (pet bottle cap, 1-piece cap, 2-piece cap, instant coffee Caps, seasoning caps, cosmetic container caps, etc.), other various containers (ink containers, cosmetic containers, shampoo containers, detergent containers, etc.), daily necessities (costume cases, buckets, washbasins, writing utensils, containers, toys, cookware, etc.) Other various cases, etc.) and the like.

In order to efficiently produce injection molded products, a multi-cavity mold that simultaneously molds multiple products is used, but if the materials used do not have sufficient rigidity, crystallinity, and fluidity, high productivity will result. I can't get it. By using the polypropylene-based resin composition (X) used in the present invention, an injection-molded article with high productivity can be obtained.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The methods for measuring physical properties and materials used are as follows.

[Method of evaluating physical properties]
(1) MFR
The melt flow rates (MFR) of the propylene homopolymer (A), the propylene-ethylene block copolymer component (A) and the polypropylene resin composition (X) are JIS K-7210-1999 (230°C, 2. 16 kg load). The melt flow rate (MFR) of the ethylene polymer (C) is measured according to JIS K-6922-2 (190°C, 2.16 kg load).
(2) Bending elastic modulus A test piece was molded by an injection molding method, and after molding, left for 5 days or more in a temperature-controlled room controlled at a room temperature of 23° C. and a relative humidity of 50%, and then determined according to JIS K7171 (ISO178). It was
(3) Charpy impact strength A test piece was molded by an injection molding method, and after molding, left for 5 days or more in a temperature-controlled room controlled at room temperature of 23°C and relative humidity of 50%, and then in an environment of 0°C for 30 minutes or more. Was adjusted according to JIS K7111 (ISO179).
(4) Transparency (Haze, haze)
A flat plate having a thickness of 0.5 mmt, 1.0 mmt, and 2.0 mmt was molded by an injection molding method, and after molding, the plate was allowed to stand in a thermostatic chamber controlled at room temperature of 23° C. and relative humidity of 50% for 24 hours, and then JIS K7136 (ISO14782). ) Was obtained in accordance with.
(5) Molding cycle Using a Sumitomo Heavy Industries injection molding machine SG125M-H, a dessert cup mold having a side wall thickness of 0.7 mmt and an internal capacity of 180 ml was used, and the cylinder temperature was 200°C, the manifold temperature was 200°C, and the mold temperature was 20°C. Was injection-molded, and the shortest cooling time was evaluated in which the product did not remain in the fixed mold for 20 consecutive shots. For this cooling time, 15 seconds or more was evaluated as ×, if it was within the range of 11 to 15 seconds, it was evaluated as Δ, if it was within the range of 5 to 10 seconds, it was evaluated as ○, and if it was less than 5 seconds, it was evaluated.

[Materials used]
(1) Propylene-ethylene block copolymer component (a)
As each propylene-ethylene block copolymer (PP-1 to 6) obtained in Production Examples 1 to 6 below, and as (PP-7), Novatec PP BC03GS (trade name of Nippon Polypro Co., Ltd.) is used. I was there.

<Production Example 1 (PP-1)>
(I) Production of solid catalyst component (A) Preparation of solid component An autoclave with a volume of 10 L equipped with a stirrer was sufficiently replaced with nitrogen, and 2 L of purified toluene was introduced. At room temperature, 200 g of Mg(OEt) ₂ and 1 L of TiCl ₄ were added. The temperature was raised to 90° C. and 50 ml of di-n-butyl phthalate was added. Then, the temperature was raised to 110° C. and a 3Hr reaction was performed. The reaction product was thoroughly washed with purified toluene, and then purified toluene was added to make the total liquid volume 2 L. At room temperature, 1 L of TiCl ₄ was added, the temperature was raised to 110° C., and 2Hr reaction was performed. After thoroughly washing the reaction product with purified toluene, the toluene was replaced with n-heptane using purified n-heptane to obtain a slurry of solid component A1. When a part of this slurry was sampled, dried and analyzed, the Ti content of the solid component A1 was 2.7 wt %.
Next, the autoclave having a capacity of 20 L equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the slurry of the solid component A1 was prepared as the solid component A1. Purified n-heptane was introduced into this to adjust the concentration of the solid component A1 to 25 g/L, 50 ml of SiCl ₄ was added, and 1 Hr reaction was carried out at 90°C.
The reaction product was thoroughly washed with purified n-heptane, and purified n-heptane was added to adjust the liquid volume to 4 L. Here, dimethyl divinyl silane 30 _ml, was added 80g as (i-Pr) 2 Si ( OMe) 2 to 30 ml, _Et 3 Al of n- heptane dilution _Et 3 Al, were 2Hr reaction at 40 ° C.. The reaction product was thoroughly washed with purified n-heptane, a part of the obtained slurry was sampled, dried and analyzed, and the Ti content of the solid component A1 was 1.2 wt%, (i-Pr). ₂ Si(OMe) ₂ was contained at 8.8 wt %.
Preliminary Polymerization Using the solid component A1 obtained above, preliminary polymerization was carried out by the following procedure. Purified n-heptane was introduced into the above slurry to adjust the concentration of the solid component to 20 g/L. Then, after cooling the slurry to 10 ° C., and 10g added n- heptane dilution of _Et 3 Al as _Et 3 Al, a propylene 280g were fed 4Hr seat. After supplying propylene, the reaction was further performed for 30 minutes, the gas phase was sufficiently replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried to obtain a solid catalyst component A. The solid catalyst component A contained 2.5 g of polypropylene per 1 g of the solid component. Further, the solid catalyst component A except for polypropylene contained 1.0 wt% of Ti and 8.2 wt% of (i-Pr) ₂ Si(OMe) ₂ .

(Ii) Production of Propylene-Ethylene Block Copolymer (PP-1) Powder A continuous gas phase polymerization reactor consisting of two horizontal polymerization tanks equipped with a stirrer was used. 130 g/Hr of the solid catalyst component A obtained above in the first reactor (internal volume 40 m ³ ) as a solid component, and a 15 wt% hexane solution of triethylaluminum relative to 1 mol of Ti atom in the solid catalyst component A, It was continuously fed so that the molar ratio was 350. In addition, hydrogen was added so that the ratio of hydrogen concentration in the polymerization vessel to propylene concentration was 0.051, and propylene monomer was placed in the polymerization vessel so that the pressure in the polymerization vessel was 2.25 MPa and the temperature was kept at 65°C. It was supplied and the first polymerization reaction was carried out.
The reaction heat was removed by the heat of vaporization of the liquefied propylene raw material.
The propylene-based homopolymer produced in the polymerization vessel was continuously withdrawn so that the retained level of the polymer would be 50% by volume of the reaction volume and supplied to the polymerization vessel in the second polymerization step.
In the second reactor (internal volume 40 m ³ ), hydrogen was added so that the ratio of the polymer from the first polymerization step and the hydrogen concentration in the polymerization vessel to the propylene concentration was 0.020, and the ethylene concentration was propylene concentration. And ethylene in a ratio of 0.153 and a propylene monomer in a pressure of 2.2 MPa and a temperature of 60° C. were supplied to the polymerization reactor to carry out the second polymerization reaction.
The polymerization amount of the propylene-ethylene copolymer was adjusted by supplying a polymerization activity inhibitor. The heat of reaction was removed by the heat of vaporization of the liquefied propylene raw material.
The propylene-ethylene block copolymer produced in the second polymerization step was continuously withdrawn from the polymerization vessel so that the retained level of the polymer was 50% by volume of the reaction volume.
When the obtained propylene-ethylene block copolymer (PP-1) was analyzed, MFR was 25 g/10 min and ethylene content was 6.0 wt %.

(Iii) Production of Propylene-Ethylene Block Copolymer (PP-1) Pellets As a propylene-ethylene block copolymer, the following is shown for 100 parts by weight of the (PP-1) powder obtained in Production Example 1. Nucleating agent (a) 0.2 part by weight, neutralizing agent calcium stearate 0.05 part by weight, phenolic antioxidant pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4). -Hydroxyphenyl)propionate] (manufactured by BASF; hereinafter abbreviated as RA1010) 0.05 part by weight, and phosphorus-based antioxidant tris(2,4-di-t-butylphenyl)phosphite (manufactured by BASF; hereinafter). (Abbreviated as RA168) 0.05 part by weight and 0.08 part by weight of oleic acid amide as a slip agent were added, and the mixture was sealed with nitrogen using a super mixer and mixed for 3 minutes.
Then, the powder was granulated at a cylinder temperature of 200° C., a screw rotation speed of 150 rpm, and an extrusion rate of 15 kg/h using a twin-screw extruder TEM35 manufactured by Toshiba Machine Co., Ltd. while sealing the hopper with nitrogen, and a propylene-ethylene block copolymer was used. The pellet of (PP-1) was obtained.
Table 1 shows each composition of the propylene homopolymer (A) and the propylene-ethylene copolymer (B) in the propylene-ethylene block copolymer (PP-1) obtained in Production Example 1 above.

[Nucleating agent (a)]
Nucleating agent (a): ADEKA product name, ADEKA STAB NA-21, organophosphate metal salt nucleating agent

<Production Example 2 (PP-2)>
85% by weight of the propylene-ethylene block copolymer (PP-1) pellets obtained in Production Example 1 was used, and propylene homopolymer (HPP-1): Novatec PP SA06GA (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst. : 15% by weight of Ziegler catalyst and MFR: 60 g/10 min were added, and blending and granulation were performed in the same manner as in Production Example 1 to obtain pellets of a propylene-ethylene block copolymer (PP-2). Table 2 shows each composition and the like.

<Production Example 3 (PP-3)>
25 wt% of propylene homopolymer (HPP-1) was added to 75 wt% of propylene-ethylene block copolymer (PP-1), blending and granulation were carried out in the same manner as in Production Example 1, and propylene- Pellets of ethylene block copolymer (PP-3) were obtained. Table 2 shows each composition and the like.

<Production Example 4 (PP-4)>
40 wt% of propylene homopolymer (HPP-1) was added to 60 wt% of propylene-ethylene block copolymer (PP-1), blending and granulation were carried out in the same manner as in Production Example 1, and propylene- Pellets of the ethylene block copolymer (PP-4) were obtained. Table 2 shows each composition and the like.

<Production Example 5 (PP-5)>
60 wt% of a propylene homopolymer (HPP-1) was added to 40 wt% of a propylene-ethylene block copolymer (PP-1), blending and granulation were carried out in the same manner as in Production Example 2, and propylene- Pellets of ethylene block copolymer (PP-5) were obtained. Table 2 shows each composition and the like.

<Production Example 6 (PP-6)>
80% by weight of propylene homopolymer (HPP), propylene-ethylene elastomer (PE-1): Vistamaxx6102 (trade name of Exxonmobil), catalyst: metallocene catalyst, MFR (230°C): 3 g/10 minutes, containing ethylene. Amount: 16 wt% of 20 wt% was added, and blending and granulation were performed in the same manner as in Production Example 2 to obtain pellets of propylene-ethylene block copolymer (PP-6). Table 2 shows each composition and the like.

<PP-7>
PP-7: Novatec PP BC03GS (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: Ziegler catalyst, propylene-ethylene copolymer content: 17 wt%, ethylene content in propylene-ethylene copolymer: 38 wt%, propylene- Intrinsic viscosity [η] of ethylene copolymer (B): 3.8 dl/g, MFR: 30 g/10 min.
Table 2 shows each composition and the like.

Ethylene polymer (C)
(C-1) LDPE: Novatec LD LJ802 (trade name of Nippon Polyethylene Co., Ltd.), MFR (190° C.): 22 g/10 minutes, density: 0.918 g/cm ³ , melting point: 106° C.
(C-2) LDPE: Novatec LD LJ902 (trade name, manufactured by Nippon Polyethylene Co., Ltd.), MFR (190° C.): 45 g/10 minutes, density: 0.915 g/cm ³ , melting point: 102° C.
(C-3) LLDPE: Novatec LL UJ580 (trade name of Nippon Polyethylene Co., Ltd.), MFR (190° C.): 20 g/10 minutes, density: 0.925 g/cm ³ , melting point: 123° C.
(C-4) LLDPE: Novatec LL UJ370 (trade name, manufactured by Nippon Polyethylene Co., Ltd.), MFR (190° C.): 16 g/10 minutes, density: 0.921 g/cm ³ , melting point: 121° C.
(C-5) Ethylene-based plastomer: Kernel KS571 (trade name, manufactured by Japan Polyethylene Corporation), MFR (190°C): 24 g/10 minutes, density: 0.907 g/cm ³ , melting point: 100°C.
(C-6) Ethylene-based plastomer: Kernel KS560T (trade name, manufactured by Japan Polyethylene Corporation), MFR (190°C): 16.5 g/10 minutes, density: 0.898 g/cm ³ , melting point: 90°C

[Example 1]
(1) Production of polypropylene resin composition (X) As a propylene-ethylene block copolymer component (a), 85 wt% of (PP-1) and 15 wt% of C-1 as an ethylene polymer (C), After sealing with nitrogen using a super mixer, the mixture was mixed for 3 minutes.
Then, using a twin-screw extruder TEM35 manufactured by Toshiba Machine Co., Ltd., while granulating the hopper with nitrogen, the granulation was performed at a cylinder temperature of 200° C., a screw rotation speed of 150 rpm, and an extrusion rate of 15 kg/h to obtain a polypropylene resin composition (X) It was

(2) Manufacture of injection-molded article (injection-molded article) The polypropylene resin composition (X) pellets obtained above were used to supply to a Toshiba injection molding machine EC100, and the injection primary pressure was 50 MPa and the molding temperature was 200. C., the mold cooling water temperature was 40.degree. C., and the molding cycle was 15 seconds to mold the test piece and the test flat plate.
The physical properties of the above-mentioned items (flexural modulus, Charpy impact strength, Haze) were evaluated for the obtained test pieces and test flat plates. Table 3 shows the evaluation results of the physical properties and moldability.

[Example 2]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that (C-2) was used as the ethylene polymer (C). The results are shown in Table 3.

[Example 3]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that (C-5) was used as the ethylene polymer (C). The results are shown in Table 3.

[Comparative Example 1]
A polypropylene resin composition (X) and an injection molded article were obtained in the same manner as in Example 1 except that (C-3) was used as the ethylene polymer (C). The results are shown in Table 3.

[Comparative example 2]
A polypropylene resin composition (X) and an injection molded article were obtained in the same manner as in Example 1 except that (C-4) was used as the ethylene polymer (C). The results are shown in Table 3.

[Comparative Example 3]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that (C-6) was used as the ethylene polymer (C). The results are shown in Table 3.

As is clear from Table 3, Examples 1 to 3 which are injection-molded products obtained by using the polypropylene resin composition (X) of the present invention have transparency, rigidity, impact resistance and moldability. It turns out that it is good.
On the other hand, in Comparative Examples 1 to 3 which do not satisfy the constituent requirements of the polypropylene resin composition (X) of the present invention, the transparency is not good.

[Example 4]
In the same manner as in Example 1, except that 83 wt% of (PP-1) was used as the propylene-ethylene block copolymer component (a) and 17 wt% of C-1 was used as the ethylene polymer (C). Thus, a polypropylene resin composition (X) and an injection molded product were obtained. The results are shown in Table 4.

[Example 5]
As a propylene-ethylene block copolymer component (a), the same method as in Example 1 except that 88 wt% of (PP-1) and 12 wt% of C-1 were used as the ethylene polymer (C). Thus, a polypropylene resin composition (X) and an injection molded product were obtained. The results are shown in Table 4.

[Comparative Example 4]
In the same manner as in Example 1 except that 90 wt% of (PP-1) was used as the propylene-ethylene block copolymer component (a) and 10 wt% of C-1 was used as the ethylene polymer (C). Thus, a polypropylene resin composition (X) and an injection molded product were obtained. The results are shown in Table 4.

[Comparative Example 5]
In the same manner as in Example 1, except that 92 wt% of (PP-1) was used as the propylene-ethylene block copolymer component (a) and 8 wt% of C-1 was used as the ethylene polymer (C). Thus, a polypropylene resin composition (X) and an injection molded product were obtained. The results are shown in Table 4.

[Comparative Example 6]
In the same manner as in Example 1 except that 80% by weight of (PP-1) was used as the propylene-ethylene block copolymer component (A) and 20% by weight of C-1 was used as the ethylene polymer (C). Thus, a polypropylene resin composition (X) and an injection molded product were obtained. The results are shown in Table 4.

As is clear from Table 4, Examples 4 to 5 which are injection-molded articles obtained by using the polypropylene resin composition (X) of the present invention have transparency, rigidity, impact resistance and moldability. It turns out that it is good.
On the other hand, in Comparative Examples 4 to 5, which do not satisfy the constituent requirements of the polypropylene resin composition (X) of the present invention, the transparency is not good, and in Comparative Example 6, the moldability is not good.

[Example 6]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that 85% by weight of (PP-2) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

[Example 7]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that 85% by weight of (PP-3) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

[Comparative Example 7]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that 85 wt% of (PP-4) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

[Comparative Example 8]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that 85% by weight of (PP-5) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

[Comparative Example 9]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1, except that 85 wt% of (PP-6) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

[Comparative Example 10]
A polypropylene resin composition (X) and an injection-molded article were obtained in the same manner as in Example 1 except that 85% by weight of (PP-7) was used as the propylene-ethylene block copolymer component (A). It was The results are shown in Table 5.

As is clear from Table 5, Examples 6 to 7, which are injection-molded articles obtained by using the polypropylene resin composition (X) of the present invention, have transparency, rigidity, impact resistance and moldability. It turns out that it is good.
On the other hand, in Comparative Examples 7 to 10, which do not satisfy the constituent requirements of the polypropylene resin composition (X) of the present invention, any of transparency, rigidity, impact resistance and moldability is not good.

The injection-molded article obtained by using the polypropylene-based resin composition (X) of the present invention has good rigidity, impact resistance, transparency and moldability, and also retains the lightweight feeling characteristic of polypropylene resin. Therefore, it can be suitably used for applications such as food containers, beverage containers, caps, daily necessities, etc., and its industrial utility is extremely high.

Claims (5)

75-85 wt% of a propylene-based homopolymer (A) having a melt flow rate (MFR) of 3.5-300 g/10 minutes according to JIS K7210 (230°C, 2.16 kg load), the following (B1)- Propylene-ethylene copolymer (B) satisfying (B2) is contained in 15 to 25 wt% (provided that the total of propylene homopolymer (A) and propylene-ethylene copolymer (B) is 100 wt%) Propylene -Ethylene block copolymer component (A) 83 to 88 wt%, 12 to 17 wt% of the ethylene-α-olefin random copolymer ethylene-based polymer (C) satisfying the following (C1) to (C3). % (Provided that the total of the propylene-ethylene block copolymer component (a) and the ethylene-based polymer (C) is 100 wt%), the polypropylene-based resin composition (X) comprising:
(B1) The ethylene content is 20 to 35 wt% (however, based on the total weight of the propylene-ethylene copolymer (B) 100 wt%).
(B2) The intrinsic viscosity [η]B measured in o-dichlorobenzene at 135° C. is 2.0 to 3.0 dl/g,
(C1) the density is 0.905 to 0.920 g/cm ³ ,
(C2) has a melting point of 100° C. or higher,
(C3) MFR in accordance with JIS K6922-2 (190°C, 2.16 kg load) is 10 to 50 g/10 minutes,
The polypropylene resin composition (X) is, JIS K7210 (230 ℃, 2.16kg load) polypropylene resin composition MFR conforming to is 5 to 100 g / 10 min (X) Tona Ri, JIS K7111 ( ISO 179) 0 ° C. Charpy impact strength that complies with the 2.5 kJ / ^{m 2} or more der Ru injection molded articles. An injection-molded article comprising the polypropylene-based resin composition (X) according to claim 1, wherein the HAZE having a thickness of 1 mmt according to JIS K7136 (ISO14782) is 35% or less. The polypropylene-based resin composition (X) according to claim 1 or 2 , which has a flexural modulus of 950 MPa or more according to JIS K7171 (ISO178). Injection molded body thickness of the molded body is made of polypropylene resin composition according to any one of claims 1 to 3 which is 0.3~1.0mmt (X). Food packaging container made of injection-molded article according to any one of claims 1-4.