JP2020117687A - Polypropylene-based resin composition and foam sheet - Google Patents

Abstract

To provide a polypropylene-based resin composition capable of producing a foam sheet and a thermoformed article having uniform fine foam cells and excellent appearance, heat moldability, impact resistance, light weight, rigidity, heat resistance, heat insulating property, oil resistance and the like.SOLUTION: There is provided a polypropylene-based resin composition comprising: 67.5 to 2.5 wt.% of a polypropylene resin (A) having the following characteristics of (X-i) to (X-iv) and having a long chain branched structure; 2.5 to 67.5 wt.% of a propylene-based block copolymer (Y) which has the following characteristics of (Y-i) to (Y-v) and is a multi-stage polymer comprising a propylene (co) polymer (Y-1) and a propylene-ethylene copolymer (Y-2); and 10 to 75 wt.% of propylene-α-olefin random copolymer (Z) having the following characteristics (Z-i) to (Z-ii), wherein the total of (X), (Y) and (Z) is 100 wt.%.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention can provide a foamed sheet in which foam cells have high closed cell properties during foam molding, cells are dense, and sizes are relatively uniform, and in particular, a foaming sheet having 3.0 times or more high foaming by a T-die method. The present invention relates to a polypropylene-based resin composition suitable for producing a sheet having a magnification, a foamed sheet using the same, and a molded product thermoformed using the same.

Foaming is one of the important molding methods for polypropylene resin. Various molded products obtained by extrusion foam molding and injection foam molding are used in a wide range of applications by taking advantage of excellent properties such as heat insulating property, sound insulating property, cushioning property and energy absorbing property. Particularly in recent years, from the perspective of environmental issues, weight reduction of materials and reduction of environmental load have become important issues for technological development, and the technical field in which foamed molded articles are used tends to expand, and there is a demand for resins with high foaming performance. , Is getting stronger.
Regarding the foaming performance, the independence and size of cells are important factors, and how to increase the independence of cells and make the size uniform and dense is important. Further, such a molded product is also preferable in that it has high appearance. Particularly in the food packaging field, prepared containers, bento containers, etc. are produced by foam molding, but since these may be displayed in stores while preserving food, they have a high appearance ( (Designability) is required.
Generally, extrusion foam molding is used as a molding method for food foam trays, foam containers, and the like. Among the extrusion foam molding methods, there are a T-die method and a round die method. As an advantage of the T-die method, generally, the foamed sheet is cooled by a mirror-finished roll immediately after extrusion so that the surface of the foamed sheet is excellent in gloss and has a relatively good appearance as compared with the round die method described later. On the other hand, however, it is difficult to maintain the independence of bubbles by handling the foamed sheet with a mirror-like roll, and it is important how to prevent the deterioration of appearance due to the breakage of bubbles. This is because, especially in a sheet having a high expansion ratio such that the expansion ratio exceeds 3.0 times, bubble coalescence easily occurs due to the destruction of the bubble wall due to the growth of bubbles, and thus the independence of bubbles is maintained and It becomes difficult to maintain high appearance.
Further, in the case of forming a sheet by the round die method, the gloss and appearance of the sheet surface tend to be inferior to those of the T die method because there is no rapid foaming sheet cooling with a mirror surface roll. There is also a feature that a sheet of magnification can be obtained.
For materials with excellent foamability, conventionally, a long chain branched polypropylene having a high melt tension suitable for foam molding was used as a base, and a specific propylene-ethylene block copolymer polymerized with a Ziegler-Natta catalyst was blended. Materials have been developed for the purpose of achieving both foaming suitability and container appearance (Patent Documents 1 to 3).
On the other hand, in the extrusion molding typified by the T-die method, in order to improve the productivity, it is generally performed to increase the screw rotation speed of the extruder to increase the sheet take-up speed. In the environment in which the sheet is molded with, the shearing heat of the resin raises the temperature of the resin and increases the take-up speed, which causes excessive take-up tension in the foamed sheet, which causes deformation, coalescence, and destruction of bubbles. It will be easier. Further, in such an environment, it is impossible to obtain a foamed sheet of 3.0 times or more particularly by the T-die method with the conventional material, and not only the productivity is excellent but also the appearance is excellent. There has been a strong demand from the market for the development of materials for obtaining

Japanese Patent No. 5624851 Japanese Patent No. 6064668 Japanese Patent No. 6089765

In view of the current state of the art, an object of the present invention is to have uniform and fine foam cells, particularly in an environment where high-speed molding is performed by the T-die method of extrusion foaming, particularly at an expansion ratio of 3.0 times or more, Provided is a resin composition for obtaining a polypropylene resin (multilayer) foam having a good appearance, and a polypropylene resin (multilayer) foam sheet using the same, and thermoforming using the same. To provide the body.

As a result of intensive studies to solve the above problems, the present inventors have found that a polypropylene resin having a specific long-chain branched structure, a specific propylene (co)polymer, and a multistage stack consisting of a propylene-ethylene copolymer. By adjusting the propylene-based block copolymer, which is a united product, and the propylene-α-olefin random copolymer component polymerized with a specific metallocene catalyst at a specific blending amount, particularly 3.0 by T-die foaming method. The inventors have found that a foamed molded product having uniform and fine foamed cells and having a good appearance of the molded product can be obtained even at a high expansion ratio of at least twice, and completed the present invention.

That is, according to the first aspect of the present invention, the polypropylene resin (X) having the following characteristics (X-i) to (X-iv) and having a long-chain branched structure is used in an amount of 67.5 to 2. 5% by weight, the following properties (Yi) to (Yv), and a multistage weight consisting of a propylene (co)polymer (Y-1) and a propylene-ethylene copolymer (Y-2). Propylene-α-olefin random copolymer having 2.5 to 67.5% by weight of the propylene-based block copolymer (Y) which is a combination and having the following characteristics (Z-i) to (Z-ii). Provided is a polypropylene-based resin composition containing 10 to 75% by weight of the combined product (Z) (however, the total of (X), (Y), and (Z) is 100% by weight).
(X-i) MFR is 0.1 to 30.0 g/10 minutes.
(X-ii) The molecular weight distribution Mw/Mn by GPC is 3.0 to 10.0, and Mz/Mw is 2.5 to 10.0.
(X-iii) Melt tension (MT) (unit: g) satisfies log(MT)≧−0.9×log(MFR)+0.7 or MT≧15.
(X-iv) The amount of the para-xylene soluble component at 25°C (CXS) is less than 5.0% by weight based on the total weight of the polypropylene resin (X).
The ratio of (Yi) (Y-1) to (Y-2) is such that (Y-1) is 50 to 99% by weight and (Y-2) is 1 to 50% by weight (provided that propylene is used. The total weight of the system block copolymer (Y) is 100% by weight).
(Y-ii) The MFR of the propylene block copolymer (Y) is 0.1 to 200.0 g/10 minutes.
(Y-iii) The melting peak temperature of the propylene block copolymer (Y) exceeds 155°C.
(Y-iv) The ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 60% by weight (however, the total weight of the constituent monomers of the propylene-ethylene copolymer (Y-2) is 100% by weight).
(Yv) The intrinsic viscosity of propylene-ethylene copolymer (Y-2) in decalin at 135°C is 5.3 dl/g or more.
(Z-i) Polymerized with a metallocene catalyst.
(Z-ii) The melting peak temperature measured by DSC is 155°C or lower.

Further, according to a second aspect of the present invention, there is provided a polypropylene resin composition characterized in that, in the first aspect, the polypropylene resin (X) has the following characteristics (X-v) ( X-v): branching index absolute molecular weight Mabs are in 1,000,000 g ^'is less than 0.30 or more 0.95.

Further, according to a third aspect of the present invention, there is provided a polypropylene resin composition according to the second aspect, wherein the polypropylene resin (X) has the following characteristics (X-vi).
(X-vi): The mm fraction of 3 chains of propylene units by ¹³ C-NMR is 95% or more.

According to a fourth aspect of the present invention, 0.05 to 6.0 parts by weight of a foaming agent is contained with respect to 100 parts by weight of the polypropylene resin composition according to any one of the first to third aspects. A polypropylene resin composition for foam molding is provided.

According to a fifth aspect of the present invention, there is provided a polypropylene-based resin foam sheet, which is obtained by extrusion-molding the polypropylene-based resin composition for foam molding according to the fourth aspect.

According to a sixth aspect of the present invention, the polypropylene-based resin foam sheet according to the fifth aspect of the invention and a non-foamed layer made of a thermoplastic resin composition are coextruded. A resin multilayer foam sheet is provided.

According to a seventh aspect of the present invention, there is provided a molded article characterized by being formed by thermoforming the polypropylene resin foam sheet according to the fifth aspect or the multilayer foam sheet according to the sixth aspect. To be done.

Further, according to the eighth invention of the present invention, the polypropylene resin composition according to any one of the first to third inventions or the polypropylene resin composition for foam molding according to the fourth invention is processed by an injection molding method, Provided is a molded article characterized by being obtained by molding by any one of a thermoforming method, an extrusion molding method, a blow molding method, and a bead foam molding method.

The polypropylene resin composition of the present invention is characterized in that uniformly fine foam cells can be obtained even under severe molding conditions, and particularly in a foam sheet obtained by the T-die molding method, it is 3.0 times or more. Even if the expansion ratio is high, uniform and fine foam cells can be obtained, so that a molded product having a good appearance can be obtained.
The resulting polypropylene resin (multilayer) foamed sheet and the thermoformed body using the same have excellent expansion ratio and uniform and fine foamed cells, and have a good appearance, thermoformability, impact resistance, light weight and rigidity. Its excellent heat resistance, heat insulation, and oil resistance make it suitable for use in food containers such as trays, plates and cups, vehicle door trims, vehicle interior materials such as automobile trunk mats, packaging, stationery, and building materials. be able to.

Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention is as follows unless the gist thereof is exceeded. It is not limited to the described contents.

The polypropylene-based resin composition of the present invention (hereinafter, also referred to as “resin composition of the present invention”) has the following characteristics (X-i) to (X-iv) and has a long chain structure. Propylene (co)polymer (Y-1) having a branched structure of polypropylene resin (X) of 67.5 to 2.5% by weight and the following characteristics of (Yi) to (Yv). And 2.5 to 67.5% by weight of the propylene block copolymer (Y), which is a multi-stage polymer composed of propylene-ethylene copolymer (Y-2), and the following (Zi) to ( Z-ii) is contained in the propylene-α-olefin random copolymer (Z) in an amount of 10 to 75% by weight (however, the total of (X), (Y) and (Z) is 100% by weight). Further, the polypropylene resin composition for foam molding of the present invention is characterized by containing 0.05 to 6.0 parts by weight of a foaming agent with respect to 100 parts by weight of the polypropylene resin composition.
Below, the characteristics to be satisfied by the components (X), (Y), and (Z) will be described in detail for each item.

I. Polypropylene resin (X) having a long-chain branched structure
In the polypropylene-based resin composition of the present invention, first, a polypropylene resin (X) having the following characteristics (X-i) to (X-iv) and having a long-chain branched structure is used. To do.
Characteristic (X-i): MFR is 0.1 to 30.0 g/10 minutes.
Characteristic (X-ii): The molecular weight distribution Mw/Mn by GPC is 3.0 to 10.0, and the Mz/Mw is 2.5 to 10.0.
Characteristic (X-iii): Melt tension (MT) (unit: g) is
log(MT)≧−0.9×log(MFR)+0.7 or MT≧15
To meet any of the above.
Characteristic (X-iv): 25° C. Para-xylene soluble component amount (CXS) is less than 5.0% by weight based on the total weight of the polypropylene resin (X).
Hereinafter, the above-mentioned respective characteristic requirements defined by the present invention, a method for producing the polypropylene resin (X) having a long-chain branched structure, and the like will be specifically described.

1. Characteristic (X-i): MFR
The polypropylene resin (X) having a long-chain branched structure in the present invention needs to have a melt flow rate (MFR) of 0.1 to 30.0 g/10 minutes, preferably 0.3 to 20. 0.0 g/10 minutes, more preferably 0.5 to 10.0 g/10 minutes. When the MFR of the polypropylene resin (X) is 0.1 g/10 minutes or more, problems such as excessive load of the extruder for various moldings due to insufficient fluidity do not easily occur, while 30.0 g/10 When it is not more than minutes, the tension is sufficient, and the characteristics as a high-melting tension material are good and suitable.
The MFR is defined in JIS K7210:1999 “Plastics-Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics”, Annex A Table 1, condition M (230° C., 2.16 kg). It is measured in accordance with (load) and the unit is g/10 minutes.

2. Characteristic (X-ii): Molecular weight distribution by GPC Further, the polypropylene resin (X) having a long-chain branched structure needs to have a relatively wide molecular weight distribution, and a molecular weight obtained by gel permeation chromatography (GPC). The distribution Mw/Mn (where Mw is the weight average molecular weight and Mn is the number average molecular weight) needs to be 3.0 or more and 10.0 or less. The molecular weight distribution Mw/Mn of the polypropylene resin (X) having a long-chain branched structure is preferably in the range of 3.5 to 8.0, more preferably 4.1 to 6.0.
Furthermore, Mz/Mw (where Mz is the Z average molecular weight) is required to be 2.5 or more and 10.0 or less as a parameter that more markedly expresses the breadth of the molecular weight distribution. The preferable range of Mz/Mw is 2.8 to 8.0, and more preferably 3.0 to 6.0.
Molding workability is improved as the molecular weight distribution is broader, but those having Mw/Mn and Mz/Mw in this range are particularly excellent in molding workability.
The definitions of Mn, Mw, and Mz are described in "Basics of Polymer Chemistry" (edited by The Polymer Society of Japan, Tokyo Kagaku Dojin, 1978) and the like, and can be calculated from the molecular weight distribution curve by GPC.

The specific measuring method of GPC is as follows.
-Device: Waters GPC (ALC/GPC 150C)
・Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
・Column: Showa Denko KK AD806M/S (3 in series)
・Mobile phase solvent: Orthodichlorobenzene (ODCB)
・Measuring temperature: 140℃
・Flow rate: 1.0 ml/min
・Injection volume: 0.2 ml
-Preparation of sample: The sample prepares a 1 mg/mL solution using ODCB (containing 0.5 mg/mL BHT), and dissolves it at 140°C for about 1 hour.
The conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve prepared in advance using standard polystyrene (PS). 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 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg/mL BHT) so that each has a concentration of 0.5 mg/mL. For the calibration curve, a cubic expression obtained by approximation by the least square method is used.
The following numerical values are used for the viscosity formula [η]=K×M ^α used for conversion into the molecular weight.
PS: K=1.38×10 ⁻⁴ , α=0.7
PP: K=1.03×10 ⁻⁴ , α=0.78

3. Characteristic (X-iii): Melt tension (MT)
Furthermore, the polypropylene resin (X) having a long-chain branched structure needs to satisfy the following condition (1).
・Condition (1)
log(MT)≧−0.9×log(MFR)+0.7
Or MT≧15
Satisfying at least one of
Here, MT is a Capillograph 1B manufactured by Toyo Seiki Seisaku-sho, Ltd., and uses a capillary: diameter 2.0 mm, length 40 mm, cylinder diameter: 9.55 mm, cylinder extrusion speed: 20 mm/min, take-up speed: 4.0 m. /Minute, temperature: The melt tension when measured under the condition of 230° C., and the unit is gram. However, when the MT of the component (X) is extremely high, the resin may be broken at a take-up speed of 4.0 m/min. The tension at the speed of is MT. The measurement conditions and units of MFR are as described above.
This definition is an index for the polypropylene resin (X) having a long-chain branched structure to have a sufficient melt tension for foam molding, and in general, MT has a correlation with MFR. It is described by the relational expression with.
As described above, the method of defining MT by the relational expression with MFR is an ordinary method for those skilled in the art. The relational expression of is proposed.
log(MS)>−0.61×log(MFR)+0.82 (230° C.)
(Here, MS is synonymous with the above MT.)
In addition, Japanese Patent Laid-Open No. 2003-64193 proposes the following relational expression as a definition of polypropylene having a high melt tension.
11.32×MFR ^−0.7854 ≦MT (230° C.)
Furthermore, JP-A-2003-94504 proposes the following relational expression as a definition of polypropylene having a high melt tension.
MT≧7.52×MFR ^−0.576
(MT is 190° C., MFR is a value measured at 230° C.)

If the polypropylene resin (X) having a long-chain branched structure satisfies the above condition (1), it can be said that it is a resin having a sufficiently high melt tension and is useful for foam molding. Further, it is more preferable to satisfy the following condition (1)′, and it is further preferable to satisfy the condition (1)″.
..Condition (1)'
log(MT)≧−0.9×log(MFR)+0.9
Or MT≧15
Satisfying at least one of
..Condition (1)”
log(MT)≧−0.9×log(MFR)+1.1
Or MT≧15
Satisfying at least one of
Regarding the upper limit value of MT, it is not necessary to provide this, but in the case where MT is 40 g or less, the take-up speed does not become remarkably slow and the measurement becomes easy with the above-mentioned measuring method. In such a case, since the spreadability of the resin is considered to be good, it is preferably 40 g or less, more preferably 35 g or less, and most preferably 30 g or less.

4. Characteristics (X-iv): 25° C. Para-xylene soluble component amount (CXS)
The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has a low amount of low crystalline component which causes stickiness and bleed-out when it is made into a product. This low crystalline component is evaluated by the amount of the xylene soluble component at 25° C. (CXS), and it is necessary that it is less than 5.0% by weight, preferably the total amount of the component (X). It is 3.0% by weight or less, more preferably 1.0% by weight or less, and further preferably 0.5% by weight or less. The lower limit is not particularly limited, but is usually 0.01% by weight or more, preferably 0.03% by weight or more. Details of the CXS measurement method are as follows.
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg/ml of BHT) at 130°C to form a solution, and then the solution is left at 25°C for 12 hours. Then, the precipitated polymer is separated by filtration, p-xylene is evaporated from the filtrate, and dried under reduced pressure at 100° C. for 12 hours to recover the xylene-soluble component at room temperature. The ratio [% by weight] of the weight of the recovered component to the weight of the charged sample is defined as CXS.

The additional characteristics of the polypropylene resin (X) having a long-chain branched structure used in the present invention include the following characteristics (X-v) to (X-vi).

5. Characteristic (Xv): Branching index g'
The branching index g ^′ can be mentioned as a direct index that the polypropylene resin (X) having a long chain branched structure has a long chain branched structure. g ^′ is given by the ratio of the intrinsic viscosity [η]br of a polymer having a long-chain branched structure and the intrinsic viscosity [η]lin of a linear polymer having the same molecular weight, that is, [η]br/[η]lin. If a long-chain branched structure is present, the value is smaller than 1.
The definition of the branching index g′ is described in, for example, “Developments in Polymer Characterization-4” (JV Dawkins ed. Applied Science Publishers, 1983) and is a known index to those skilled in the art.

g ^′ can be obtained as a function of the absolute molecular weight Mabs, for example, by using a GPC equipped with a light scatterometer and a viscometer as a detector as described below.
The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has g′ of 0.30 or more and less than 0.95 when the absolute molecular weight Mabs determined by light scattering is 1,000,000. It is preferably 0.55 or more and less than 0.95, more preferably 0.75 or more and less than 0.95, and most preferably 0.78 or more and less than 0.95.
As described in detail below, the polypropylene resin (X) having a long-chain branched structure used in the present invention is considered to have a comb-shaped chain as a molecular structure due to its polymerization mechanism, and g′ is 0.30 or more. In this case, the number of main chains is small and the proportion of side chains is not extremely large, and in such a case, melt tension is improved and gel is not likely to be generated, which is preferable in foam molding. On the other hand, when g′ is less than 0.95, there is branching, so that melt tension does not tend to become insufficient easily, which is suitable for foam molding.

The lower limit of g′ is preferably the above value for the following reason.
According to the "Encyclopedia of Polymer Science and Engineering vol.2" (John Wiley & Sons 1985 p.485) , g ' value of the comb polymer is represented by the following equation.

Here, g is a branching index defined by the radius gyration ratio of the polymer, and ε is a constant determined by the shape of the branched chain and the solvent, and p. According to Table 3 of 487, a value of about 0.7 to 1.0 has been reported for comb chains in a good solvent. λ is the ratio of the main chain in the comb-shaped chain, and p is the average number of branches. According to this equation, if it is a comb-shaped chain, the number of branches will be extremely large, that is, in the limit of p being infinite, g ^' =g ^ε =λ ^ε , which is not less than the value of λ ^ε. , In general, there will be a lower limit.
On the other hand, a conventionally known formula for a random branched chain, which is considered to occur in the case of electron beam irradiation or peroxide modification, is given by the 485 page formula (19) in the same document. In the chain, as the number of branch points increases, g′ and g value decrease monotonically without any particular lower limit. That is, in the present invention, the fact that the g'value has a lower limit value means that the polypropylene resin (X) having a long chain branched structure used in the present invention has a structure close to a comb chain. As a result, the distinction from the random branched chain generated by electron beam irradiation or peroxide modification becomes more clear.
Further, in a branched polymer having a structure close to a comb chain with g'in the above range, the degree of decrease in melt tension upon repeated kneading is small, and this occurs in the step of industrially producing a molded body. For example, when a sheet, a scrap material produced by cutting an end portion during film molding, or a member such as a runner for injection molding is subjected to molding again as a recycled material, deterioration of physical properties and moldability is reduced. ,preferable.

The specific calculation method of g′ is as follows.
An Alliance GPCV2000 from Waters is used as a GPC device equipped with a differential refractometer (RI) and a viscosity detector (Viscometer). Further, as the light scattering detector, a multi-angle laser light scattering detector (MALLS) Wyatt Technology DAWN-E is used. The detectors are connected in the order of MALLS, RI, and Viscometer. The mobile phase solvent is 1,2,4-trichlorobenzene (addition of the antioxidant Irganox 1076 manufactured by BASF Japan Ltd. at a concentration of 0.5 mg/mL).
The flow rate is 1 mL/min, and two GMHHR-H(S)HTs manufactured by Tosoh Corp. are connected and used for the column. The temperature of the column, sample injection part and each detector is 140°C. The sample concentration is 1 mg/mL, and the injection amount (sample loop volume) is 0.2175 mL.
In order to obtain the absolute molecular weight (Mabs), the root mean square radius of gyration (Rg), and the intrinsic viscosity ([η]) obtained from Viscometer obtained from MALLS, the data processing software ASTRA (version 4.73.04) attached to MALLS was used. Then, the calculation is performed with reference to the following documents.
References:
1. "Developments in Polymer Characterization-4" (JV Dawkins ed. Applied Science Publishers, 1983. Chapter 1).
2. Polymer, 45, 6495-6505 (2004).
3. Macromolecules, 33, 2424-2436 (2000).
4. Macromolecules, 33, 6945-6952 (2000).

[Calculation of branching index (g')]
The branching index (g′) is the ratio of the intrinsic viscosity ([η]br) obtained by measuring the sample with the Viscometer and the intrinsic viscosity ([η]lin) separately obtained by measuring the linear polymer. It is calculated as ([η]br/[η]lin).
When a long-chain branched structure is introduced into a polymer molecule, the radius of gyration becomes smaller than that of a linear polymer molecule having the same molecular weight. Since the intrinsic viscosity becomes smaller as the radius of gyration becomes smaller, the intrinsic viscosity ([η]br) of the branched polymer with respect to the intrinsic viscosity ([η]lin) of the linear polymer having the same molecular weight as the long-chain branched structure is introduced. The ratio ([η]br/[η]lin) becomes smaller.
Therefore, when the branching index (g′=[η]br/[η]lin) becomes a value smaller than 1.0, it means that the branching has been introduced. Here, as the linear polymer for obtaining [η]lin, commercially available homopolypropylene (Novatech PP (registered trademark) grade name: FY6 manufactured by Nippon Polypro Co., Ltd.) is used. It is known as Mark-Houwink-Sakurada equation that the logarithm of [η]lin of a linear polymer has a linear relationship with the logarithm of molecular weight. It can be extrapolated to obtain a numerical value.

6. Characteristic (X-vi): mm Fraction of Propylene Unit 3 Chain by ¹³ C-NMR The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has high stereoregularity. Stereoregularity of the ^height, can be evaluated by 13 ^C-NMR, mm fraction of the propylene unit triad sequences obtained by 13 C-NMR is preferably has a 95.0% or more stereoregular.
The mm fraction is the ratio of three propylene unit chains having the same direction of methyl branch in each propylene unit in any three propylene unit chains consisting of head-to-tail bonds in the polymer chain, and the upper limit thereof is 100%. Is. This mm fraction is a value showing that the three-dimensional structure of the methyl group in the polypropylene molecular chain is isotactically controlled, and the higher the fraction, the higher the degree of control. If the mm fraction is smaller than this value, the mechanical properties such as the elastic modulus of the product tend to deteriorate.
Therefore, the mm fraction is preferably 95.0% or more, more preferably 96.0% or more, and further preferably 97.0% or more. The characteristics (X-iv) and (X-vi) are characteristics related to stereoregularity, and it is particularly preferable that the requirements of the characteristics (X-iv) and (X-vi) are simultaneously satisfied. ..

The details of the method for measuring the mm fraction of 3 chains of propylene units by ¹³ C-NMR are as follows.
A sample of 375 mg is completely dissolved in 2.5 ml of deuterated 1,1,2,2-tetrachloroethane in an NMR sample tube (10φ), and then measured at 125° C. by a complete proton decoupling method. The chemical shift sets the central peak of the three deuterated 1,1,2,2-tetrachloroethane peaks to 74.2 ppm. Chemical shifts of other carbon peaks are based on this.
Flip angle: 90 degrees Pulse interval: 10 seconds Resonance frequency: 100 MHz or more Accumulation frequency: 10,000 times or more Observation area: -20 ppm to 179 ppm
Number of data points: 32768
The analysis of the mm fraction is performed using the ¹³ C-NMR spectrum measured under the above conditions.
The attribution of the spectrum is performed with reference to Macromolecules, (1975) 8th page, 687 and Polymer, 30: 1350 (1989).
A more specific method for determining the mm fraction is described in detail in paragraphs [0053] to [0065] of Japanese Patent Application Laid-Open No. 2009-275207, and this specification is also used in this specification. To do.
In the present invention, a polypropylene resin whose characteristic (X-iii) satisfies log(MT)≧−0.9×log(MFR)+0.7 and Mabs is 1,000,000 and g′<1 is a long-chain polypropylene resin. It can be said that it has a branched structure.

7. Characteristic: Amount of polypropylene resin (X) having a long-chain branched structure The amount of polypropylene resin (X) having a long-chain branched structure is 67.5 to 2.5% by weight, preferably 60.0 to 10%. 0% by weight, more preferably 55.0 to 15.0% by weight, and further preferably 52.5 to 17.5% by weight (however, the total of (X), (Y), and (Z) is 100% by weight. %). When the compounding amount of the polypropylene resin (X) having a long-chain branched structure is within this range, shear heat generation is achieved even at a high expansion ratio of 3.0 times or more when molded at a high speed especially by the T-die method. It is possible to reduce the load applied to the sheet by the take-up tension and the take-up tension, and it is possible to obtain a foamed sheet having excellent independence and denseness of air bubbles and high appearance. Further, when the compounding amount is 67.5% by weight or less, the fluidity becomes sufficient, and there is no problem that the load of the extruder is too high for various moldings, and it is 2.5% by weight or more. In addition, the melt tension becomes sufficient, and the characteristics as a high melt tension material are excellent, and it is suitable for foam molding.

8. Method for producing polypropylene resin (X) having long-chain branched structure The polypropylene resin (X) having a long-chain branched structure is the above-mentioned (X-i) to (X-iv), and preferably (X-v). As long as the characteristics of (X-vi) are satisfied, the production method is not particularly limited, but as described above, high stereoregularity, low low crystalline component amount, relatively wide molecular weight distribution, branching index g ^' The preferred production method for satisfying all the conditions such as the above range, high melt tension and the like is a method using a macromer copolymerization method utilizing a combination of metallocene catalysts. Examples of such a method include the method disclosed in Japanese Patent Laid-Open No. 2009-57542.
This method produces a polypropylene having a long-chain branched structure by using a catalyst in which a catalyst component having a specific structure having a macromer-forming ability and a catalyst component having a specific structure having a macromolecular copolymerization ability at a high molecular weight are combined. According to this method, it is an industrially effective method such as a bulk polymerization method or a gas phase polymerization method, particularly in a single-stage polymerization under practical pressure-temperature conditions, and further, hydrogen as a molecular weight regulator is added. By using this, it is possible to produce a polypropylene resin having a long-chain branched structure having desired physical properties.
Further, conventionally, it was necessary to increase the branch formation efficiency by lowering the crystallinity by using a polypropylene component having low stereoregularity, but in the above method, a polypropylene component having sufficiently high stereoregularity was obtained. , (X-vi) and (X) relating to high stereoregularity and low low crystalline component amount, which can be introduced into the side chain by a simple method and are preferable as the polypropylene resin (X) used in the present invention. It is suitable for satisfying the characteristics of -iv).
In addition, by using the above-mentioned method, it is possible to broaden the molecular weight distribution by using two kinds of catalysts having greatly different polymerization characteristics, and it is necessary for the polypropylene resin (X) having a long chain branched structure used in the present invention (X- It is preferable because it is possible to simultaneously satisfy the characteristics i) to (X-iii).

Therefore, a preferred method for producing the polypropylene resin (X) having a long chain branched structure used in the present invention will be described in detail below.
A preferred method for producing the polypropylene resin (X) having a long-chain branched structure is a method for producing a propylene-based polymer using the following catalyst components (A), (B) and (C) as a propylene polymerization catalyst.
(A): At least one component from the component [A-1] that is a compound represented by the following general formula (a1) and at least from a component [A-2] that is a compound represented by the following general formula (a2). Two or more selected transition metal compounds of Group 4 of the periodic table.
Component [A-1]: Compound Represented by General Formula (a1) Component [A-2]: Compound Represented by General Formula (a2) (B): Ion Exchangeable Layered Silicate (C): Organoaluminum Compound

Hereinafter, the catalyst components (A), (B) and (C) will be described in detail.
(1) Catalyst component (A)
(I) Component [A-1]: compound represented by general formula (a1)

In formula (a1), R ¹¹ and R ¹² each independently represent a heterocyclic group containing nitrogen or oxygen having 4 to 16 carbon atoms, or sulfur. Further, R ¹³ and R ¹⁴ are each independently aryl having 6 to 16 carbon atoms, which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these. Group, a heterocyclic group containing 6 to 16 carbon atoms, nitrogen, oxygen, or sulfur. Further, X ¹¹ and Y ¹¹ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or a halogenated group having 1 to 20 carbon atoms. Represents a hydrocarbon group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group or a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, Q ¹¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, It represents a silylene group or a germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms.

The heterocyclic group containing nitrogen or oxygen having 4 to 16 carbon atoms of R ¹¹ and R ¹² , and sulfur is preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group, It is a substituted 2-furfuryl group, and more preferably a substituted 2-furfuryl group.
Further, as the substituent of the substituted 2-furyl group, the substituted 2-thienyl group, and the substituted 2-furfuryl group, a methyl group, an ethyl group, an alkyl group having 1 to 6 carbon atoms such as a propyl group, Examples thereof include a halogen atom such as a fluorine atom and a chlorine atom, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group, and a trialkylsilyl group. Of these, a methyl group and a trimethylsilyl group are preferable, and a methyl group is particularly preferable.
Furthermore, as R ¹¹ and R ¹² , a 2-(5-methyl)-furyl group is particularly preferable. Further, it is preferable that R ¹¹ and R ¹² are the same as each other.
Examples of the aryl group having 6 to 16 carbon atoms of R ¹³ and R ¹⁴ that may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these are: Within the range of 6 to 16 carbon atoms, one or more hydrocarbon groups having 1 to 6 carbon atoms, silicon-containing hydrocarbon groups having 1 to 6 carbon atoms, and halogens having 1 to 6 carbon atoms on the aryl cyclic skeleton. It may have a contained hydrocarbon group as a substituent.

As R ¹³ and R ¹⁴ , at least one is preferably a phenyl group, a 4-methylphenyl group, a 4-i-propylphenyl group, a 4-t-butylphenyl group, a 4-trimethylsilylphenyl group, 2,3-dimethyl. Phenyl group, 3,5-di-t-butylphenyl group, 4-phenyl-phenyl group, chlorophenyl group, naphthyl group, or phenanthryl group, more preferably phenyl group, 4-i-propylphenyl group, 4- a t-butylphenyl group, a 4-trimethylsilylphenyl group and a 4-chlorophenyl group. Further, it is preferable that R ¹³ and R ¹⁴ are the same as each other.

In the general formula (a1), X ¹¹ and Y ¹¹ are auxiliary ligands, which react with the cocatalyst of the catalyst component (B) to produce an active metallocene having olefin polymerization ability. Therefore, as long as this object is achieved, X ¹¹ and Y ¹¹ are not limited in the type of ligand, and each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. , A C 1-20 silicon-containing hydrocarbon group, a C 1-20 halogenated hydrocarbon group, a C 1-20 oxygen-containing hydrocarbon group, an amino group or a C 1-20 nitrogen-containing hydrocarbon. A group, an alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, and a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms are shown.

In general formula (a1), Q ¹¹ is a silylene that may have a divalent hydrocarbon group having 1 to 20 carbon atoms and a hydrocarbon group having 1 to 20 carbon atoms, which bonds two five-membered rings. Represents either a group or a germylene group. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure.
Specific examples of the above Q ¹¹ include alkylene groups such as methylene, methylmethylene, dimethylmethylene, 1,2-ethylene; arylalkylene groups such as diphenylmethylene; silylene groups; methylsilylene, dimethylsilylene, diethylsilylene, diethylene. An alkylsilylene group such as (n-propyl)silylene, di(i-propyl)silylene, di(cyclohexyl)silylene, an (alkyl)(aryl)silylene group such as methyl(phenyl)silylene; an arylsilylene group such as diphenylsilylene; Alkyloligosilylene group such as tetramethyldisilylene; Germylene group; Alkylgermylene group obtained by substituting germanium for silicon of silylene group having a divalent hydrocarbon group having 1 to 20 carbon atoms; (alkyl) (aryl) Germylene group; arylgermylene group and the like can be mentioned. Among these, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms or a germylene group having a hydrocarbon group having 1 to 20 carbon atoms is preferable, and an alkylsilylene group and an alkylgermylene group are particularly preferable.

Among the compounds represented by the general formula (a1), preferable compounds are specifically exemplified below.
Dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)-4-phenyl-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(2-thienyl)-4-phenyl -Indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, dichloro[1,1'-diphenylsilylenebis{2 -(5-Methyl-2-furyl)-4-phenyl-indenyl}]hafnium, dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl} ] Hafnium, dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-thienyl)-4-phenyl-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-( 5-t-butyl-2-furyl)-4-phenyl-indenyl}] hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-trimethylsilyl-2-furyl)-4-phenyl-indenyl}] Hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-phenyl-2-furyl)-4-phenyl-indenyl}] hafnium, dichloro[1,1'-dimethylsilylenebis{2-(4, 5-Dimethyl-2-furyl)-4-phenyl-indenyl}]hafnium dichloride, dichloro[1,1′-dimethylsilylenebis{2-(2-benzofuryl)-4-phenyl-indenyl}]hafnium, dichloro[1 ,1′-Dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-methylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5- Methyl-2-furyl)-4-(4-ipropylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4- Trimethylsilylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(2-furfuryl)-4-phenyl-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2- (5-Methyl-2-furyl)-4-(4-chlorophenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4 -Fluorophenyl )-Indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trifluoromethylphenyl)-indenyl}]hafnium, dichloro[1, 1′-Dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(2 -Furyl)-4-(1-naphthyl)-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, dichloro [1,1'-Dimethylsilylenebis{2-(2-furyl)-4-(2-phenanthryl)-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)- 4-(9-phenanthryl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(1-naphthyl)-indenyl}]hafnium, dichloro [1,1'-Dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5 -Methyl-2-furyl)-4-(2-phenanthryl)-indenyl}] hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(9-phenanthryl) )-Indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(1-naphthyl)-indenyl}]hafnium, dichloro[1,1 '-Dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-t -Butyl-2-furyl)-4-(2-phenanthryl)-indenyl}] hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(9 -Phenanthryl)-indenyl}] hafnium, and the like.

Among these, more preferable are dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium and dichloro[1,1′-dimethylsilylene. Bis{2-(5-methyl-2-furyl)-4-(4-methylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl) -4-(4-ipropylphenyl)-indenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl} ] Hafnium, dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-chlorophenyl)-indenyl}] hafnium, dichloro[1,1'-dimethylsilylenebis{ 2-(5-Methyl-2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4- (4-t-butylphenyl)-indenyl}] hafnium.
Further, particularly preferred are dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{ 2-(5-Methyl-2-furyl)-4-(4-ipropylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)- 4-(4-Trimethylsilylphenyl)-indenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)-indenyl} ] Hafnium.

(Ii) Component [A-2]: compound represented by general formula (a2)

In formula (a2), R ²¹ and R ²² each independently represent a hydrocarbon group having 1 to 6 carbon atoms, and R ²³ and R ²⁴ each independently represent halogen, silicon, oxygen, or sulfur. , Nitrogen, boron, phosphorus, or an aryl group having 6 to 16 carbon atoms which may contain a plurality of hetero elements selected from these. X ²¹ and Y ²¹ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon having 1 to 20 carbon atoms. Group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group or a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, Q ²¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a carbon number. It represents a silylene group or a germylene group which may have 1 to 20 hydrocarbon groups. M ²¹ is zirconium or hafnium.

R ²¹ and R ²² are each independently a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, n-pentyl, i-pentyl, n-hexyl and the like, preferably methyl. , Ethyl and n-propyl.

In addition, each of R ²³ and R ²⁴ independently contains halogen, silicon, or a plurality of hetero elements having 6 to 16 carbon atoms, preferably 6 to 12 carbon atoms, selected from these. Is also an aryl group. Preferred examples are phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4- (2-Fluoro-4-biphenylyl), 4-(2-chloro-4-biphenylyl), 1-naphthyl, 2-naphthyl, 4-chloro-2-naphthyl, 3-methyl-4-trimethylsilylphenyl, 3,5 -Dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl, 3,5-dichloro-4-trimethylsilylphenyl and the like can be mentioned.

Further, the above X ²¹ and Y ²¹ are auxiliary ligands, and react with the cocatalyst of the catalyst component (B) to generate active metallocene having olefin polymerization ability. Therefore, as long as this object is achieved, X ²¹ and Y ²¹ are not limited in the kind of the ligand, and each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, Silicon-containing hydrocarbon group having 1 to 20 carbon atoms, halogenated hydrocarbon group having 1 to 20 carbon atoms, oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, amino group or nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms , An alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, and a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms.

In addition, Q ²¹ is a bonding group that bridges two conjugated five-membered ring ligands, and has a divalent hydrocarbon group having 1 to 20 carbon atoms and a hydrocarbon group having 1 to 20 carbon atoms. A silylene group which may be substituted or a germylene group having a hydrocarbon group having 1 to 20 carbon atoms, and preferably a substituted silylene group or a substituted germylene group.

The substituent bonded to silicon or germanium is preferably a hydrocarbon group having 1 to 12 carbon atoms, and two substituents may be linked. Specific examples include methylene, dimethylmethylene, ethylene-1,2-diyl, dimethylsilylene, diethylsilylene, diphenylsilylene, methylphenylsilylene, 9-silafluorene-9,9-diyl, dimethylsilylene, diethylsilylene, Examples thereof include diphenylsilylene, methylphenylsilylene, 9-silafluorene-9,9-diyl, dimethylgermylene, diethylgermylene, diphenylgermylene and methylphenylgermylene.

Further, M ²¹ is zirconium or hafnium, preferably hafnium.

The following may be mentioned as non-limiting examples of the metallocene compound represented by the above general formula (a2).
However, the following describes only typical exemplified compounds while avoiding many complicated examples, and the present invention is not construed as being limited to these compounds, and various ligands, cross-linking groups or auxiliary It is self-evident that the ligand can be used optionally. Further, although a compound in which the central metal is hafnium is described, a compound in which zirconium is substituted is also treated as disclosed in the present specification.

Dichloro{1,1'-dimethylsilylenebis(2-methyl-4-phenyl-4-hydroazurenyl)}hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4 -Hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{ 2-Methyl-4-(4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-methyl-4-(3-chloro-4-t-butylphenyl)- 4-Hydroazurenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-methyl-4-(3-methyl-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, dichloro[1,1′ -Dimethylsilylenebis{2-methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl) -4-Trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(1-naphthyl)-4-hydroazurenyl}]hafnium, dichloro[1,1' -Dimethylsilylenebis{2-methyl-4-(2-naphthyl)-4-hydroazulenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chloro-2-naphthyl)] -4-Hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-fluoro-4-biphenylyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethyl Silylene bis{2-methyl-4-(2-chloro-4-biphenylyl)-4-hydroazurenyl}]hafnium, dichloro[1,1′-dimethylsilylene bis{2-methyl-4-(9-phenanthryl)-4. -Hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chlorophenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-n -Propyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazurenyl}]huff , Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{ 2-Ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1′-dimethylgermylenebis{2-methyl-4-(2-fluoro-4-biphenylyl) )-4-Hydroazurenyl}]hafnium, dichloro[1,1′-dimethylgermylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1′- (9-Silafluorene-9,9-diyl)bis{2-ethyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-ethyl-4- (4-Chloro-2-naphthyl)-4-hydroazurenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium , Dichloro[1,1′-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, and the like. Can be mentioned.

Of these, dichloro[1,1′-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium and dichloro[1,1′-dimethylsilylenebis{2- Methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4] -Hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis {2-Ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl- 4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazurenyl}]hafnium.

Further, particularly preferably, dichloro[1,1′-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, dichloro[1,1′-dimethylsilylenebis{2-ethyl] -4-(2-Fluoro-4-biphenylyl)-4-hydroazurenyl}]hafnium, dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4- Hydroazurenyl}]hafnium, dichloro[1,1′-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazurenyl}] Hafnium.

(2) Catalyst component (B)
The catalyst component (B) preferably used for producing the polypropylene resin (X) is an ion-exchange layered silicate.
(I) Types of ion-exchange layered silicates Ion-exchange layered silicates (hereinafter sometimes simply referred to as silicates) are layers in which ionic bonds and the like are stacked in parallel with each other by a binding force. A silicate compound having a different crystal structure and having exchangeable ions contained therein. Since most silicates are naturally produced mainly as the main components of clay minerals, impurities other than ion-exchange layered silicates (quartz, cristobalite, etc.) are often contained, but they are also included. But it's okay. Depending on the type, amount, particle size, crystallinity, and dispersion state of these contaminants, it may be preferable to pure silicate or more, and such a complex is also included in the catalyst component (B).
The silicate used in the present invention is not limited to a naturally occurring silicate, and may be an artificial synthetic product or may contain them.

Specific examples of the silicate include the following layered silicates described in "Clay Mineralogy" written by Haruo Shiramizu, Asakura Shoten (1995).
That is, smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, vermiculites such as vermiculite, mica, illite, sericite, mica such as glauconite, attapulgite, sepiolite, palygorskite. , Bentonite, pyrophyllite, talc, chlorite, etc.
The silicate is preferably a silicate having a 2:1 type structure as a main component, more preferably a smectite group, and particularly preferably montmorillonite. The type of the interlayer cation is not particularly limited, but a silicate containing an alkali metal or an alkaline earth metal as a main component of the interlayer cation is preferable from the viewpoint of being relatively easily and inexpensively available as an industrial raw material.

(Ii) Chemical Treatment of Ion-Exchanged Layered Silicate The ion-exchanged layered silicate of the catalyst component (B) according to the present invention can be used as it is without any particular treatment, but it is preferably subjected to a chemical treatment. .. Here, the chemical treatment of the ion-exchange layered silicate may be either a surface treatment for removing impurities adhering to the surface or a treatment for affecting the structure of the clay. Treatment, alkali treatment, salt treatment, organic matter treatment and the like can be mentioned.

<Acid treatment>:
The acid treatment can remove impurities on the surface as well as elute part or all of cations such as Al, Fe and Mg having a crystal structure.
The acid used in the acid treatment is preferably selected from hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid and oxalic acid.
Two or more kinds of salts (described in the next section) and acids used for the treatment may be used. The treatment conditions with salts and acids are not particularly limited, but usually, the concentration of salts and acid is 0.1 to 50% by weight, the treatment temperature is room temperature to boiling point, and the treatment time is 5 minutes to 24 hours. It is preferable to perform it under the condition that at least a part of the substance constituting at least one compound selected from the group consisting of ion-exchange layered silicates is eluted. Further, salts and acids are generally used as an aqueous solution.
In addition, a combination of the following acids and salts may be used as a treating agent. Also, a combination of these acids and salts may be used.

<Salt treatment>:
Before the treatment with salts, 40% or more, preferably 60% or more, of the cations of the exchangeable Group 1 metal contained in the ion-exchange layered silicate are converted into cations dissociated from the salts shown below. It is preferable to perform ion exchange.
The salt used in the salt treatment for the purpose of such ion exchange is composed of a cation containing at least one atom selected from the group consisting of atoms of Groups 1 to 14 of the Periodic Table, a halogen atom, an inorganic acid and an organic acid. A compound comprising at least one anion selected from the group consisting of, and more preferably, a cation containing at least one atom selected from the group consisting of atoms of Groups 2 to 14 of the periodic table and Cl, Br, I. , F, PO ₄ , SO ₄ , NO ₃ , CO ₃ , C ₂ O ₄ , ClO ₄ , OOCCH ₃ , CH ₃ COCHCOCH ₃ , OCl ₂ , O(NO ₃ ) ₂ , O(ClO ₄ ) ₂ , O( _{SO 4), OH, O 2} Cl 2, OCl 3, OOCH, in _{OOCCH 2 CH 3, C 2 H} 4 O 4 and _C 5 _H 5 consisting of at least one anionic selected from the group consisting of _{O 7} compound is there.

Specific examples of such _{salts, LiF, LiCl, LiBr, LiI} , Li 2 SO 4, Li (CH 3 COO), LiCO 3, Li (C 6 H 5 O 7), LiCHO 2, LiC 2 O 4 , LiClO ₄ , Li ₃ PO ₄ , CaCl ₂ , CaSO ₄ , CaC ₂ O ₄ , Ca(NO ₃ ) ₂ , Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , MgCl ₂ , MgBr ₂ , MgSO ₄ , Mg( _{PO 4) 2, Mg (ClO} 4) 2, MgC 2 O 4, Mg (NO 3) 2, Mg (OOCCH 3) 2, MgC 4 H 4 O 4 and the like.

Moreover, Ti(OOCCH ₃ ) ₄ , Ti(CO ₃ ) ₂ , Ti(NO ₃ ) ₄ , Ti(SO ₄ ) ₂ , TiF ₄ , TiCl ₄ , Zr(OOCCH ₃ ) ₄ , Zr(CO ₃ ) ₂ , Zr(NO ₃ ) ₄ , Zr(SO ₄ ) ₂ , ZrF ₄ , ZrCl ₄ , ZrOCl ₂ , ZrO(NO ₃ ) ₂ , ZrO(ClO ₄ ) ₂ , ZrO(SO ₄ ), HF(OOCCH ₃ ) ₄ , _{HF (CO 3) 2, HF} (NO 3) 4, HF (SO 4) 2, HFOCl 2, HFF 4, HFCl 4, V (CH 3 COCHCOCH 3) 3, VOSO 4, VOCl 3, VCl 3, VCl 4 , VBr _{3 and the} like.

_{Further, Cr (CH 3 COCHCOCH 3)} 3, Cr (OOCCH 3) 2 OH, Cr (NO 3) 3, Cr (ClO 4) 3, CrPO 4, Cr 2 (SO 4) 3, CrO 2 Cl 2, CrF _{3, CrCl 3, CrBr 3,} CrI 3, Mn (OOCCH 3) 2, Mn (CH 3 COCHCOCH 3) 2, MnCO 3, Mn (NO 3) 2, MnO, Mn (ClO 4) 2, MnF 2, MnCl _{2, Fe (OOCCH 3) 2} , Fe (CH 3 COCHCOCH 3) 3, FeCO 3, Fe (NO 3) 3, Fe (ClO 4) 3, FePO 4, FeSO 4, Fe 2 (SO 4) 3, FeF3 , FeCl ₃ , FeC ₆ H ₅ O _{7 and the} like.

Also, Co(OOCCH ₃ ) ₂ , Co(CH ₃ COCHCOCH ₃ ) ₃ , CoCO ₃ , Co(NO ₃ ) ₂ , CoC ₂ O ₄ , Co(ClO ₄ ) ₂ , Co ₃ (PO ₄ ) ₂ , CoSO ₄ , CoF ₂ , CoCl ₂ , NiCO ₃ , Ni(NO ₃ ) ₂ , NiC ₂ O ₄ , Ni(ClO ₄ ) ₂ , NiSO ₄ , NiCl ₂ , NiBr _{2, and the} like.
_{Furthermore, Zn (OOCCH 3) 2,} Zn (CH 3 COCHCOCH 3) 2, ZnCO 3, Zn (NO 3) 2, Zn (ClO 4) 2, Zn 3 (PO 4) 2, ZnSO 4, ZnF 2, ZnCl _{2, AlF 3, AlCl 3,} AlBr 3, AlI 3, Al 2 (SO 4) 3, Al 2 (C 2 O 4) 3, Al (CH 3 COCHCOCH 3) 3, Al (NO 3) 3, AlPO 4 , GeCl ₄ , GeBr ₄ , GeI _{4 and the} like.

<Alkaline treatment>:
In addition to the acid and salt treatments, the following alkali treatments and organic substance treatments may be performed as necessary. Examples of the treating agent used in the alkali treatment include LiOH, NaOH, KOH, Mg(OH) ₂ , Ca(OH) ₂ , Sr(OH) ₂ and Ba(OH) ₂ .

<Organic matter treatment>:
Examples of organic treating agents used for treating organic substances include trimethylammonium, triethylammonium, N,N-dimethylanilinium, and triphenylphosphonium.
Further, as the anion constituting the organic substance treating agent, in addition to the anion exemplified as the anion constituting the salt treating agent, for example, hexafluorophosphate, tetrafluoroborate, tetraphenylborate, etc. are exemplified. It is not limited to these.

Further, these treating agents may be used alone or in combination of two or more kinds. These combinations may be used in combination with the treatment agents added at the start of the treatment, or may be used in combination with the treatment agents added during the treatment. Further, the chemical treatment can be performed multiple times using the same or different treatment agents.
These ion-exchange layered silicates usually contain adsorbed water and interlayer water. In the present invention, it is preferable to remove these adsorbed water and interlayer water and use them as the catalyst component (B).

The heat treatment method for the adsorbed water of the ion-exchange layered silicate and the interlayer water is not particularly limited, but it is necessary to select conditions so that the interlayer water does not remain and the structure is not destroyed. The heating time is 0.5 hours or longer, preferably 1 hour or longer. At that time, when the water content of the catalyst component (B) after removal was 0% by weight when the water content was 0% by weight when dehydrated for 2 hours under the conditions of a temperature of 200° C. and a pressure of 1 mmHg (133 Pa). % Or less, preferably 1% by weight or less.

As described above, in the present invention, the particularly preferable catalyst component (B) is an ion-exchange layered silicic acid having a water content of 3% by weight or less, which is obtained by performing a salt treatment and/or an acid treatment. It is salt.

The ion-exchange layered silicate is preferable because it can be treated with a catalyst component (C) of an organoaluminum compound described below before forming a catalyst or using it as a catalyst. The amount of the catalyst component (C) used with respect to 1 g of the ion-exchange layered silicate is not limited, but is usually 20 mmol or less, preferably 0.5 mmol or more and 10 mmol or less. The treatment temperature and time are not limited, and the treatment temperature is usually 0° C. or higher and 70° C. or lower, and the treatment time is 10 minutes or longer and 3 hours or shorter. It is also possible and preferable to wash after the treatment. As the solvent, the same hydrocarbon solvent as that used in the pre-polymerization method or slurry polymerization method described later is used.

Further, as the catalyst component (B), it is preferable to use spherical particles having an average particle diameter of 5 μm or more. As long as the particles have a spherical shape, a natural product or a commercially available product may be used as it is, or a particle whose particle shape and particle size are controlled by granulation, sizing, fractionation, or the like may be used.
The granulation method used here includes, for example, a stirring granulation method and a spray granulation method, but a commercially available product can also be used.
Further, at the time of granulation, an organic substance, an inorganic solvent, an inorganic salt or various binders may be used.
The spherical particles obtained as described above desirably have a compressive fracture strength of 0.2 MPa or more, particularly preferably 0.5 MPa or more, in order to suppress crushing and generation of fine powder in the polymerization step. In the case of such a particle strength, the effect of improving the particle property is effectively exhibited, particularly when prepolymerization is carried out.

(3) Catalyst component (C)
The catalyst component (C) is an organoaluminum compound. As the organoaluminum compound used as the catalyst component (C), a compound represented by the general formula: (AlR ³¹ _q Z _3-q ) _p is suitable.
In the present invention, it goes without saying that the compound represented by this formula can be used singly, as a mixture of two or more kinds, or in combination. In this formula, R ³¹ represents a hydrocarbon group having 1 to 20 carbon atoms, and Z represents a halogen, hydrogen, an alkoxy group or an amino group. q represents an integer of 1 to 3, and p represents an integer of 1 to 2. R ³¹ is preferably an alkyl group, and Z is chlorine when it is a halogen, an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and a C 1 to 1 when it is an amino group. An amino group of 8 is preferred.

Specific examples of the organic aluminum compound include trimethyl aluminum, triethyl aluminum, trinormal propyl aluminum, trinormal butyl aluminum, triisobutyl aluminum, trinormal hexyl aluminum, trinormal octyl aluminum, trinormal decyl aluminum, diethyl aluminum chloride, diethyl aluminum. Examples thereof include sesquichloride, diethyl aluminum hydride, diethyl aluminum ethoxide, diethyl aluminum dimethylamide, diisobutyl aluminum hydride, diisobutyl aluminum chloride and the like.
Among these, trialkyl aluminum having p=1 and q=3 and dialkyl aluminum hydride having p=1 and q=2 are preferable. More preferably, R ³¹ is trialkylaluminum having 1 to 8 carbon atoms.

(4) Formation of Catalyst/Preliminary Polymerization As for the catalyst, the catalyst components (A) to (C) are brought into contact with each other in the (preliminary) polymerization tank at the same time or continuously, or once or plural times. Can be formed by
The contact of each component is usually carried out in an aliphatic hydrocarbon or aromatic hydrocarbon solvent. The contact temperature is not particularly limited, but it is preferably carried out between -20°C and 150°C. The order of contact may be any combination that is purposeful, but the particularly preferable ones are shown below for each component.
When using the catalyst component (C), before contacting the catalyst component (A) with the catalyst component (B), the catalyst component (A) or the catalyst component (B) or the catalyst component (A) and the catalyst Contacting both the component (B) with the catalyst component (C), or contacting the catalyst component (A) with the catalyst component (B) and simultaneously contacting the catalyst component (C), or the catalyst component It is possible to contact the catalyst component (C) after contacting (A) with the catalyst component (B), but it is preferable to contact the catalyst before contacting the catalyst component (A) with the catalyst component (B). It is a method of contacting with either component (C).
Further, after bringing the respective components into contact with each other, it is possible to wash with an aliphatic hydrocarbon or aromatic hydrocarbon solvent.

The amounts of the catalyst components (A), (B) and (C) used are arbitrary. For example, the amount of the catalyst component (A) used with respect to the catalyst component (B) is preferably 0.1 μmol to 1,000 μmol, and particularly preferably 0.5 μmol to 500 μmol with respect to 1 g of the catalyst component (B). The amount of the catalyst component (C) with respect to the catalyst component (A) is preferably in the range of 0.01 to 5×10 ⁶ , particularly preferably 0.1 to 1×10 ⁴ , in terms of the transition metal molar ratio. preferable.

The ratio of the component [A-1] (compound represented by the general formula (a1)) and the component [A-2] (compound represented by the general formula (a2)) used in the present invention is propylene-based. It is optional within a range satisfying the above-mentioned properties of the polymer, but is preferably 0.30 or more in a molar ratio of the transition metal of [A-1] to the total amount of each component [A-1] and [A-2]. , 0.99 or less.
By changing this ratio, it is possible to adjust the balance between the melt property and the catalytic activity. That is, a low molecular weight terminal vinyl macromer is produced from the component [A-1], and a high molecular weight product obtained by copolymerizing a part of the macromer is produced from the component [A-2]. Therefore, by changing the ratio of the component [A-1], the average molecular weight of the produced polymer, the molecular weight distribution, the deviation of the molecular weight distribution toward the high molecular weight side, the extremely high molecular weight component, the branch (amount, length, The distribution) can be controlled, and thereby the melt physical properties such as strain hardening degree, melt tension and melt spreadability can be controlled.

In order to produce a higher strain-hardening propylene-based polymer, it is preferably 0.30 or more, more preferably 0.40 or more, still more preferably 0.5 or more. In addition, the upper limit is preferably 0.99 or less, more preferably 0.95 or less, and further preferably 0.90 or less in order to efficiently obtain the polypropylene resin (X) with high catalytic activity. It is a range.
Further, by using the component [A-1] within the above range, it is possible to adjust the balance between the average molecular weight and the catalytic activity with respect to the hydrogen amount.

The catalyst according to the present invention is subjected to a prepolymerization treatment, which comprises contacting it with an olefin and polymerizing it in a small amount. By performing the prepolymerization treatment, it is possible to prevent the formation of gel during the main polymerization. It is considered that the reason is that the long-chain branch can be uniformly distributed among the polymer particles at the time of the main polymerization, and the melt property can be improved by that.

The olefin used in the prepolymerization is not particularly limited, but propylene, ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, Styrene etc. can be illustrated. The olefin feed method may be any method such as a feed method for maintaining the olefin in the reaction tank at a constant rate or in a constant pressure state, a combination thereof, or a stepwise change.
The prepolymerization temperature and time are not particularly limited, but are preferably in the range of -20°C to 100°C and 5 minutes to 24 hours, respectively. The amount of the prepolymerized polymer is preferably 0.01 to 100, more preferably 0.1 to 50 in terms of the weight ratio of the prepolymerized polymer to the catalyst component (B). Further, the catalyst component (C) can be added or added during the prepolymerization. It is also possible to wash after the completion of the preliminary polymerization.

In addition, a method in which a polymer such as polyethylene or polypropylene and a solid of an inorganic oxide such as silica or titania are allowed to coexist during or after the contact of each of the above components is also possible.

(5) Use of Catalyst/Regarding Propylene Polymerization Any polymerization mode can be used as long as the olefin polymerization catalyst containing the catalyst component (A), the catalyst component (B) and the catalyst component (C) is efficiently contacted with the monomer. Can be adopted.
Specifically, a slurry polymerization method using an inert solvent, using propylene as a solvent without substantially using an inert solvent, a so-called bulk polymerization method, a solution polymerization method or a method of gasifying each monomer without using a substantially liquid solvent. A gas phase polymerization method for maintaining the shape can be adopted. Further, a method of performing continuous polymerization or batch polymerization is also applied. In addition to single-stage polymerization, it is also possible to carry out multi-stage polymerization of two or more stages.
In the case of the slurry polymerization method, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene or toluene is used alone or as a mixture as a polymerization solvent.

The polymerization temperature is 0°C or higher and 150°C or lower. In particular, when the bulk polymerization method is used, the temperature is preferably 40°C or higher, more preferably 50°C or higher. The upper limit is preferably 80°C or lower, more preferably 75°C or lower.
Further, when using a gas phase polymerization method, the temperature is preferably 40° C. or higher, more preferably 50° C. or higher. The upper limit is preferably 100°C or lower, more preferably 90°C or lower.
The polymerization pressure is preferably 1.0 MPa or more and 5.0 MPa or less. In particular, when using bulk polymerization, the pressure is preferably 1.5 MPa or more, more preferably 2.0 MPa or more. The upper limit is preferably 4.0 MPa or less, more preferably 3.5 MPa or less.

Furthermore, when using the gas phase polymerization method, the pressure is preferably 1.5 MPa or more, more preferably 1.7 MPa or more. The upper limit is preferably 2.5 MPa or less, more preferably 2.3 MPa or less.
Further, as a molecular weight modifier and for the effect of improving the activity, it is advisable to use hydrogen in a molar ratio of 1.0×10 ⁻⁶ to 1.0×10 ⁻² with respect to propylene. it can.

Further, by changing the amount of hydrogen used, in addition to the average molecular weight of the polymer produced, the molecular weight distribution, the bias toward the high molecular weight side of the molecular weight distribution, very high molecular weight component, branching (amount, length, The distribution) can be controlled, thereby controlling the melt properties that characterize polypropylene having a long-chain branched structure, such as MFR, strain hardening degree, melt tension MT, and melt spreadability.
Therefore, it is preferable to use hydrogen in a molar ratio to propylene of 1.0×10 ⁻⁶ or more, preferably 1.0×10 ⁻⁵ or more, and more preferably 1.0×10 ⁻⁴ or more. Is good. The upper limit is preferably 1.0×10 ⁻² or less, preferably 0.9×10 ⁻² or less, and more preferably 0.8×10 ⁻² or less.

In addition to the propylene monomer, copolymerization may be carried out using an α-olefin comonomer having 2 to 20 carbon atoms other than propylene, such as ethylene and/or 1-butene, as a comonomer, depending on the application.
Therefore, in order to obtain the polypropylene resin (X) used in the present invention having a good balance of catalytic activity and melt property, use ethylene and/or 1-butene in an amount of 15 mol% or less with respect to propylene. Is preferable, more preferably 10.0 mol% or less, and further preferably 7.0 mol% or less.

When propylene is polymerized using the catalyst and the polymerization method exemplified here, one end of the polymer is mainly propenyl by a special chain transfer reaction generally called β-methyl elimination from the active species derived from the catalyst component [A-1]. The structure is shown and so-called macromers are generated. It is considered that this macromer can generate a higher molecular weight and is incorporated into the active species derived from the catalyst component [A-2] having a better copolymerizability, and the macromer copolymerization proceeds. Therefore, it is considered that the comb-shaped chain is the main as the branched structure of the polypropylene resin having a long-chain branched structure to be generated.

8. Other Properties of Polypropylene Resin (X) Having Long Chain Branch Structure As a further additional feature of the polypropylene resin (X) having a long chain branch structure used in the present invention, which is produced by the above-mentioned method, a strain rate of 0 is obtained. The strain hardening degree (λmax(0.1)) in the measurement of extensional viscosity at 0.1 s ⁻¹ is preferably 6.0 or more.
The strain hardening degree (λmax (0.1)) is an index showing the strength during melting, and if this value is large, there is an effect of improving the melt tension. As a result, the closed cell ratio can be increased when foam molding is performed. When the degree of strain hardening is preferably 6.0 or more, the closed cell property can be kept higher, and more preferably 8.0 or more.

Details of the calculation method of λmax (0.1) will be described below.
-[Lambda]max (0.1) calculation method The elongation viscosity when the temperature is 180[deg.] C. and the strain rate is 0.1 s< ^-1 >, the horizontal axis represents time t (seconds), and the vertical axis represents the elongation viscosity [eta] _E (Pa.second). Plot in a log-log graph. The viscosity immediately before strain hardening is approximated by a straight line on the log-log graph.
Specifically, first, the slope at each time when the extensional viscosity is plotted against time is obtained. In this regard, considering that the measurement data of extensional viscosity is discrete, various averaging methods are used. To use. For example, there is a method in which the slopes of adjacent data are obtained and the moving average of several surrounding points is calculated.
The extensional viscosity becomes a simple increasing function in the low strain amount region, and gradually approaches a constant value, and if there is no strain hardening, it coincides with the Troton viscosity after a sufficient time has passed, but in the case of strain hardening, it is generally Then, from about 1 strain amount (= strain rate x time), the extensional viscosity starts to increase with time. That is, the slope tends to decrease with time in the low strain region, but it tends to increase from the strain amount of about 1, and there is an inflection point on the curve when the extensional viscosity is plotted against time. .. Therefore, within the strain amount range of 0.1 to 2.5, the point where the slope of each time obtained above has the minimum value is obtained, a tangent line is drawn at that point, and the straight line has the strain amount of 4.0. Extrapolate until The maximum value (ηmax) of the extensional viscosity η _E until the strain amount reaches 4.0, and the viscosity on the approximate straight line until that time is η lin. ηmax/ηlin is defined as λmax(0.1).

The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has high stereoregularity as described above, whereby a molded product having high rigidity can be produced. The polypropylene resin (X) is homopolypropylene, or propylene-α with a small amount of α-olefin or other comonomer such as ethylene, 1-butene or 1-hexene, as long as it satisfies the various properties described above. It may be an olefin random copolymer. When the polypropylene resin (X) is homopolypropylene, the crystallinity is high and the melting peak temperature is high, but even when the polypropylene resin (X) is a propylene-α-olefin random copolymer, the melting peak is high. Higher temperatures are preferred.
More specifically, the melting peak temperature obtained by differential scanning calorimetry (DSC) is preferably 145°C or higher, more preferably 150°C or higher. When the melting peak temperature is higher than 145°C, it is preferable from the viewpoint of heat resistance of the product, but the upper limit of the melting peak temperature of the polypropylene resin (X) is usually 170°C or lower.
The melting peak temperature is determined by differential scanning calorimetry (DSC), and once the temperature is raised to 200° C. to erase the thermal history, the temperature is lowered to 40° C. at a temperature lowering rate of 10° C./min, and then again. It is the temperature of the endothermic peak top when measured at a heating rate of 10° C./min.

II. Propylene-based block copolymer (Y)
The propylene block copolymer (Y), which is a component that constitutes the polypropylene resin composition according to the present invention, is a propylene (co)polymer (Y-1) (hereinafter A propylene-based block copolymer (Y) which is a multistage polymer composed of "(Y-1)") and a propylene-ethylene copolymer (Y-2) (hereinafter also referred to as "(Y-2)"). To use.
The term block copolymer as used herein is commonly used by those skilled in the art, and is a common name for propylene-based resin compositions obtained by carrying out multistage polymerization by a sequential polymerization method, and at each stage. It is different from a so-called (real) block copolymer or graft copolymer in which the polymerized components are bonded by a chemical bond. Multi-stage polymerization Since the components produced in each process are not chemically bonded, it is generally necessary to use the difference in crystallinity, molecular weight, solubility in solvents, etc. to separate the crystalline fractions. It is possible to separate the components produced in each step by a method such as molecular weight fractionation, solubility fractionation, or the like.
Further, in the block copolymer (Y) obtained by the conventionally known stepwise polymerization method, the long-chain branched structure due to the chemical bond like the polypropylene resin (X) does not exist with an analyzable accuracy.

The propylene block copolymer (Y) may be produced using any catalyst such as a conventionally known Ziegler-Natta catalyst or a metallocene catalyst, and the production method is also a conventionally known slurry polymerization method or bulk. Various combinations of polymerization methods, gas phase polymerization methods and the like can be used.
Here, the Ziegler-Natta catalyst is, for example, "Polypropylene Handbook" by Edward P. Moore Jr. Ed., Tetsuo Yasuda/Nobu Sakuma, supervised translation, and the catalyst system as outlined in Section 2.3.1 (Pages 20-57) of the Industrial Research Committee (1998), such as titanium trichloride and halogen. A titanium trichloride-based catalyst composed of organoaluminum chloride, a solid catalyst component containing magnesium chloride, titanium halide, and an electron-donating compound as an essential component, and a magnesium-supported catalyst composed of organoaluminum and an organosilicon compound, and a solid catalyst component. A catalyst in which an organoaluminum compound component is combined with an organosilicon-treated solid catalyst component formed by contacting an organoaluminum and an organosilicon compound. Further, the metallocene catalyst has already been described in detail in the description of the “method for producing polypropylene resin (X)”. Among the above examples, the catalyst [A-2] as the catalyst component (A) is particularly preferably used for the production of the propylene block copolymer (Y).

Preferred catalysts are, for example, titanium tetrachloride compositions obtained by reducing titanium tetrachloride with an organoaluminum compound and further treating with various electron donors and electron acceptors, organoaluminum compounds and aromatic carboxylic acid esters. (See JP-A-56-100806, JP-A-56-120712 and JP-A-58-104907), magnesium halide and titanium tetrachloride and various electron donors. Examples of the supported catalysts (see JP-A-57-63310, JP-A-63-43915, and JP-A-63-83116), which are brought into contact with each other, and the like.

The propylene (co)polymer (Y-1) produced in the first stage of the sequential polymerization is a propylene homopolymer or a propylene random copolymer obtained by copolymerizing a small amount of a comonomer without departing from the scope of the present invention. Is. As the comonomer, α-olefins having up to about 10 carbon atoms excluding 3 such as ethylene, 1-butene and 1-hexene are usually used. When a comonomer is included, it can be illustrated that the comonomer content in the propylene (co)polymer (Y-1) is 0.1 to 5.0% by weight (provided that the propylene (co)polymer (Y The total weight of the monomers constituting -1) is 100% by weight).

1. Characteristic (Y-i): Quantity ratio of (Y-1) and (Y-2) In the present invention, the weight ratio of (Y-1) and (Y-2) is such that (Y-1) is 50 to 99. %, preferably 55 to 97% by weight, more preferably 60 to 95% by weight. Correspondingly, (Y-2) is 1 to 50% by weight, preferably 3 to 45% by weight, more preferably 5 to 40% by weight.
(However, the total weight of the propylene block copolymer (Y) is 100% by weight)
When the amount of (Y-2) is 1% by weight or more, the melt tension is not too low and it is suitable for foam molding, while when it is 50% by weight or less, the crystalline component (Y-1) is used. Does not become too small, so the heat resistance and rigidity of the composition are not impaired.

2. Characteristic (Y-ii): MFR
The propylene block copolymer (Y) used in the present invention has a MFR range of 0.1 to 200 g/10 minutes, preferably 0.2 to 190 g/10 minutes, and more preferably 0.5. ˜180 g/10 min, particularly preferably 2.1 to 170 g/10 min.
This is a range of the MFR of the resin used for various moldings, which is a usual range, and when it is 0.1 g/10 minutes or more, the load of the extruder becomes excessive and the flow instability of the resin becomes On the other hand, when it is 200 g/10 minutes or less, problems such as a large neck-in during extrusion molding and difficulty in sheet take-up hardly occur.
The method for measuring MFR is the same as the method for measuring polypropylene resin (X) described above.

3. Characteristic (Y-iii): melting peak temperature The melting peak temperature of the propylene block copolymer (Y) used in the present invention needs to be higher than 155°C from the viewpoint of maintaining heat resistance of the sheet. And is preferably 157° C. or higher. The upper limit of the melting peak temperature does not need to be particularly limited, but it is practically difficult to produce a material having a melting peak temperature exceeding 170°C.
The melting peak temperature was measured by using differential operation calorimetry (DSC), and once the temperature was raised to 200°C to erase the thermal history, the temperature was lowered to 40°C at a cooling rate of 10°C/min, and increased again. It is the temperature of the endothermic peak top when measured at a temperature rate of 10° C./min.

4. Characteristic (Y-iv): Ethylene content in propylene-ethylene copolymer (Y-2) In the present invention, ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 60% by weight. Are required (however, the total weight of the monomers constituting the propylene-ethylene copolymer (Y-2) is 100% by weight). The preferable range of ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 38% by weight, more preferably 16 to 36% by weight, and further preferably 18 to 35% by weight.
When the ethylene content is within the above range, the dispersion state of (Y-2) in the polypropylene resin composition is good, and the foaming suitability is excellent.

5. Characteristic (Y-v): Intrinsic viscosity of propylene-ethylene copolymer (Y-2) As a result of many experimental studies, the present inventors have found that the propylene block copolymer (Y ), the intrinsic viscosity value of the propylene-ethylene copolymer (Y-2) measured with 135°C decalin as a solvent must be 5.3 dl/g or more, and preferably 6.0 dl/g. It has been found that it is at least g, more preferably at least 7.0 dl/g, and most preferably at least 7.5 dl/g.

When the intrinsic viscosity value is 5.3 dl/g or more, the melt tension is high and the foaming suitability is good.
The upper limit is not particularly specified, but if it is too high, it causes gelation, so it is 25.0 dl/g or less, preferably 20.0 dl/g or less, more preferably 18.0 dl/g or less. , And most preferably 16.0 dl/g or less.
The intrinsic viscosity here is a value measured using a Ubbelohde-type capillary viscometer with a temperature of 135° C. and decalin as the solvent. In order to obtain the intrinsic viscosity of (Y-2), the component (Y-2) was recovered as a 25° C. para-xylene soluble component using the same method as described in the above CXS, and the intrinsic viscosity of the component (Y-2) was measured. Assumed to be performed. However, when the ethylene content of the component (Y-2) is less than 15% by weight, it becomes difficult to sufficiently separate the component (Y-2) depending on the method of CXS. In such a case, a small amount of the (Y-1) component after the completion of the production of the propylene (co)polymer (Y-1) produced in the previous stage of the sequential polymerization during the sequential polymerization is extracted to obtain a unique property. The viscosity is measured, and further, the intrinsic viscosity of the whole (Y) after the completion of the sequential polymerization is measured and determined by the following formula.
Intrinsic viscosity of component (Y-2)=[(Y) overall intrinsic viscosity-{(Y-1) intrinsic viscosity×(Y-1) component weight fraction/100}]/{(Y-2 ) Component weight fraction/100}

Here, as a method for determining the ratio of (Y-1) and (Y-2) in the component (Y) and the ethylene content in (Y-2), conventionally known IR, NMR, or solubility fractionation is used. It can be determined by an analysis method or the like that combines the method and the IR method.
In the present invention, various indexes of the component (Y) are mainly determined by a combination of the cross fractionation method and the FT-IR method described below.

(1) Analytical equipment to be used (i) Cross fractionation device CFC T-100 (abbreviated as CFC) manufactured by Dia Instruments Co., Ltd.
(Ii) Fourier transform infrared absorption spectrum analysis FT-IR analyzer: Perkin Elmer 1760X
The fixed wavelength infrared spectrophotometer attached as the CFC detector is removed and an 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 CFC to FT-IR has a length of 1 m, and the temperature is maintained at 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 kept at 140° C. throughout the measurement.
(Iii) Gel permeation chromatography (GPC)
The GPC column at the latter stage of CFC is used by connecting three AD806MS manufactured by Showa Denko KK in series.

(2) CFC measurement conditions (i) Solvent: Orthodichlorobenzene (ODCB)
(Ii) Sample concentration: 4 mg/mL
(Iii) Injection volume: 0.4 mL
(Iv) Crystallization: The temperature is lowered from 140° C. to 40° C. over about 40 minutes.
(V) Separation method:
The temperature for elution fractionation at the elevated temperature is 40, 100, 140° C., and the fractions are separated 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.
(Vi) Solvent flow rate during elution: 1 mL/min

(3) FT-IR measurement conditions After elution of the sample solution from GPC in 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 conceptual diagram of CFC-FT-IR is shown in, for example, JP-A-2018-135419 and JP-A-2017-031359.
(I) Detector: MCT
(Ii) Resolution: 8 cm ^-1
(Iii) Measurement interval: 0.2 minutes (12 seconds)
(Iv) Number of integrations per measurement: 15 times

(4) Post-treatment and analysis of measurement results The elution amount and molecular weight distribution of the components eluted at each temperature are obtained by using the absorbance at 2945 cm ⁻¹ obtained by FT-IR measurement 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 volume to the molecular weight is performed using a calibration curve based on standard polystyrene prepared in advance. The specific method is the same as that described above.
Ethylene content distribution of each eluted component (ethylene content distribution along the molecular weight axis), using the ratio between the absorbance of the absorbance and 2927cm ^-1 of 2956Cm ^-1 obtained by GPC-IR, of polyethylene or polypropylene ¹³ Converted to ethylene content (wt%) by a calibration curve prepared in advance using ethylene-propylene rubber (EPR) and a mixture thereof whose ethylene content is known by C-NMR measurement and the like. And ask.

(5) Propylene-Ethylene Copolymer Content The propylene-ethylene copolymer (Y-2) (hereinafter, referred to as EP) content of the propylene block copolymer (Y) in the present invention has the following formula (I). ) Is defined by the following procedure.
EP content (% by weight)=W40×A40/B40+W100×A100/B100+W140×A140/B140 (I)
W40, W100, W140 is the elution ratio (unit: weight %) in each of the above-mentioned fractions, and A40, A100, A140 is the average ethylene content of the actual measurement in each fraction corresponding to W40, W100, W140. (Unit: wt%), and B40, B100, and B140 are ethylene contents (unit: wt%) of EP contained in each fraction.
How to obtain A40, A100, A140, B40, B100, B140 will be described later.
The meaning of the formula (I) is as follows. The first term on the right side of the formula (I) is a term for calculating the amount of EP contained in the fraction 1 (portion soluble at 40° C.). When Fraction 1 contains only EP and does not contain PP, W40 contributes to the EP content derived from Fraction 1 as it is in the whole, but Fraction 1 contains a small amount in addition to EP-derived components. Since components derived from PP (components having extremely low molecular weight and atactic polypropylene) are also included, it is necessary to correct that portion. Therefore, the amount derived from the EP component in the fraction 1 is calculated by multiplying W40 by A40/B40. For example, when the average ethylene content (A40) of Fraction 1 is 30% by weight and the ethylene content (B40) of EP contained in Fraction 1 is 40% by weight, 30/40=3/4 of Fraction 1 That is, 75% by weight is derived from EP and the remaining 1/4 is derived from PP. Thus, the operation of multiplying A40/B40 by the first term on the right side means that the contribution of EP is calculated from the weight% of fraction 1 (W40). The same applies to the second term on the right side and thereafter, and the EP content is calculated by adding the contribution of EP for each fraction and adding them.

(I) As described above, the average ethylene contents corresponding to the fractions 1 to 3 obtained by the CFC measurement are A40, A100, and A140, respectively (the units are all% by weight). The method for obtaining the average ethylene content will be described later.
(Ii) 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 fractions 2 and 3, it is considered that the rubber part is completely eluted at 40° C. and cannot be defined by the same definition. Therefore, in the present invention, B100=B140=100 is defined. B40, B100, and B140 are the ethylene content of EP contained in each fraction, but it is virtually impossible to analytically determine this value. The reason is that there is no means for completely separating/separating PP and EP mixed in the fraction. As a result of study using various model samples, it was found that B40 can well 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. It was In addition, B100 and B140 have crystallinity derived from ethylene chain and that the amount of EP contained in these fractions is relatively small compared to the amount of EP contained in fraction 1; Therefore, it is closer to the actual condition when both are closer to 100, and there is almost no error in calculation. Therefore, B100=B140=100 is set for analysis.

(Iii) The EP content is calculated according to the following formula.
EP content (% by weight)=W40×A40/B40+W100×A100/100+W140×A140/100 (II)
That is, W40×A40/B40, which is the first term on the right side of the formula (II), represents the EP content (% by weight) having no crystallinity, and is W100×A100/ which is the sum of the second term and the third term. 100+W140×A140/100 indicates the EP content (% by weight) having crystallinity.
Here, the average ethylene contents A40, A100, and A140 of the respective fractions 1 to 3 obtained by B40 and CFC measurement are determined as follows.
The fraction 1 fractionated by the difference in crystal distribution was converted into a molecular weight distribution curve by a curve in which the molecular weight distribution was measured by a GPC column constituting a part of the CFC analyzer and FT-IR connected after the GPC column. A correspondingly measured ethylene content distribution curve is determined. The ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B40.
The average ethylene content A40 is the sum of the products of the weight percentage of each data point and the ethylene content of each data point, which are taken in as data points during measurement.

The significance of setting the three types of separation temperatures is as follows.
In the CFC analysis of the present invention, 40° C. means only a polymer having no crystallinity (for example, most of EP, or extremely low molecular weight component and atactic component among propylene polymer components (PP)). It has the significance of being a temperature condition necessary and sufficient for separation. Further, 100° C. means a component that is insoluble at 40° C. but soluble at 100° C. (for example, a component having crystallinity due to a chain of ethylene and/or propylene in EP, and low crystallinity). The temperature is sufficient to elute only PP). Further, 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 PP and a component having extremely high molecular weight and ethylene crystallinity in EP). ) Is eluted and the temperature is necessary and sufficient for recovering the total amount of the propylene-based block copolymer used for analysis. The EP component contained in W140 is extremely small, and can be substantially ignored.
Ethylene content in EP (% by weight)=(W40×A40+W100×A100+W140×A140)/[EP] (III)
However, [EP] is the EP content (% by weight) obtained previously.
The ethylene content (E) (% by weight) of the EP having no crystallinity is approximated by the value of B40, since the elution of the rubber portion is completed at almost 40° C. or lower.

However, in the analysis method by the combination of the cross fractionation method and the FT-IR method described above, the ethylene content of (Y-2) is less than 15% by weight, and there is no large difference in crystallinity from (Y-1), Accurate analysis becomes difficult when it is not possible to perform sufficient separation by. In such a case, the (Y-1) component after the completion of the production of the propylene (co)polymer (Y-1) produced in the polymerization in the first stage of the sequential polymerization in the course of the sequential polymerization is extracted and the molecular weight thereof is extracted. (When the comonomer is copolymerized, the comonomer content is also measured) is measured, and the amount ratio of the component (Y-1) and the component (Y-2) is determined by calculation by material balance. It is preferable to determine the comonomer content of the component (Y-2) by measuring the comonomer content of the entire component (Y) at the end of the sequential polymerization and using the following simple addition rule of weight. When ethylene is used as a comonomer, the ethylene content of (Y-2) is determined by the following formula.
Ethylene content of component (Y-2)=[ethylene content of (Y) overall-ethylene content of component (Y-1) x weight fraction of component (Y-1)/100}]/{(Y-2 ) Component weight fraction/100}

Regarding another method for obtaining the amount ratio of the (Y-1) component and the (Y-2) component, in the case of producing those in which the average molecular weights of the (Y-1) component and the (Y-2) component are somewhat different from each other, GPC measurement of the whole (Y) after completion of the sequential polymerization is performed, and the obtained multimodal molecular weight distribution curve is peak-separated by using commercially available data analysis software or the like, and the weight ratio thereof is calculated. You can also

6. Characteristics: Amount of propylene-based block copolymer (Y) blended The amount of the propylene-based block copolymer (Y) blended is 2.5 to 67.5% by weight, preferably 10.0 to 60.0% by weight, It is more preferably 15.0 to 55.0% by weight, and further preferably 17.5 to 52.5% by weight (however, the total of (X), (Y), and (Z) is 100% by weight). .. When the blending amount of the propylene block copolymer (Y) is within this range, the shear heat generation and the take-up are performed especially at a high molding rate by the T-die method and even at a high expansion ratio exceeding 3.0 times. It is possible to reduce the load applied to the sheet by the tension, and it is possible to obtain a foamed sheet having excellent independence and denseness of cells and high appearance. Further, when the compounding amount is 67.5% by weight or less, the fluidity becomes sufficient, and there is no problem that the load of the extruder is too high for various moldings, and it is 2.5% by weight or more. In addition, the melt tension becomes sufficient, and the characteristics as a high melt tension material are excellent, and it is suitable for foam molding.

III. Propylene-α-olefin random copolymer (Z)
The propylene-α-olefin random copolymer (Z) is produced by using a conventionally known metallocene catalyst, and various production methods such as a conventionally known slurry polymerization method, bulk polymerization method and gas phase polymerization method are used. Combinations can be used.
Here, the metallocene catalyst has already been described in detail in the description of the “method for producing polypropylene resin (X)”. Among the above examples, those using the component [A-2] as the catalyst component (A) are exemplified as the catalyst preferably used for the production of the propylene-α-olefin random copolymer (Z). be able to.

As the α-olefin of the propylene-α-olefin random copolymer (Z), ethylene, 1-butene, 1-hexene such as α-olefins having up to about 10 carbon atoms excluding 3 can be selected.

As a result of many experimental studies, the present inventors have found that the propylene-α-olefin random copolymer (Z) blended in the polypropylene resin composition has particularly high-speed molding when it has the following properties. In die foam molding, even in a foam sheet having a high expansion ratio of more than 3.0 times, a polypropylene-based foam having uniform fine cells and excellent independence and a molded article having a good appearance can be obtained. I found that. It will be described in detail below.

1. Characteristic (Z-i): Polymerized with metallocene catalyst The propylene-α-olefin random copolymer (Z) used in the present invention needs to be polymerized with a metallocene catalyst. A propylene-α-olefin random copolymer polymerized with a metallocene catalyst can suppress an increase in the amount of oligomer components even if the amount of α-olefin increases, as compared with that polymerized with a Ziegler-Natta catalyst. It is possible to suppress the stickiness of the molded product.

2. Characteristic (Z-ii): Melt peak temperature measured by DSC is 155° C. or lower. In order to improve the spreadability of the resin, the temperature needs to be 155°C or lower, preferably 145°C or lower, more preferably 140°C or lower, particularly preferably 135°C or lower, and most preferably 130°C or lower. Is. The melting peak temperature was measured by using differential operation calorimetry (DSC), and once the temperature was raised to 200°C to erase the thermal history, the temperature was lowered to 40°C at a cooling rate of 10°C/min, and increased again. It is the temperature of the endothermic peak top when measured at a temperature rate of 10° C./min.
When the melting peak temperature is 155° C. or lower, the effect of maintaining the independence of bubbles is exhibited. The lower limit of the melting peak temperature is not particularly limited, but 100° C. is preferable from the viewpoint of heat distortion resistance as a molded product.

3. Characteristic: Blending amount of propylene-α-olefin random copolymer (Z) The blending amount of the propylene-α-olefin random copolymer used in the present invention is 10 to 75% by weight, preferably 25 to 75% by weight, It is more preferably 30 to 70% by weight, further preferably 35 to 65% by weight, and particularly preferably 40 to 60% by weight (however, the total of (X), (Y) and (Z) is 100% by weight. ).
When the blending amount of the propylene-α-olefin random copolymer (Z) is within this range, shearing occurs even at a high expansion ratio of 3.0 times or more, especially when molded at a high speed by the T-die method. It is possible to reduce the load applied to the sheet due to heat generation and the take-up tension, and it is possible to obtain a foamed sheet having excellent independence and denseness of air bubbles and high appearance. When the content is 10% by weight or more, the polypropylene resin composition has sufficient spreadability and excellent foaming suitability, and when it is 75% by weight or less, the rigidity and melting peak temperature of the polypropylene resin composition are high. The molded product does not deform or melt when used at high temperatures.

4. Characteristic: α-olefin content As the α-olefin of the propylene-α-olefin random copolymer (Z), ethylene, 1-butene, 1-hexene such as α-olefins having up to about 10 carbon atoms excluding 3 can be used. It can be selected, but is preferably ethylene.
The α-olefin content in the propylene-α-olefin random copolymer (Z) is preferably 0.5 to 5.0% by weight, more preferably 0.8 to 4.5% by weight, and further It is preferably 0.9 to 4.0% by weight. When the α-olefin content is within this range, a polypropylene-based foam having uniform and fine foam cells, improved spreadability, and good appearance of the molded product can be obtained. Further, when the amount of α-olefin is 0.5% by weight or more, the propylene-α-olefin random copolymer (Z) has excellent spreadability, and when the amount of α-olefin is 5.0% by weight or less. The rigidity and melting peak temperature of the propylene-α-olefin random copolymer (Z) are improved, and deformation or melting does not occur as a molded article when used at high temperature.

5. Properties: Melt Flow Rate The melt flow rate (MFR) of the propylene-α-olefin random copolymer (Z) is preferably in the range of 0.1 to 100.0 g/10 minutes, more preferably 1.0 to. 80.0 g/10 minutes, more preferably 5.0 to 70.0 g/10 minutes, even more preferably 10.0 to 60.0 g/10 minutes, particularly preferably 15.0 to 55.0 g/10 minutes, Most preferably, it is 21.0 to 50.0 g/10 minutes. When the MFR of the propylene-α-olefin random copolymer (Z) is within this range, a polypropylene-based foam having uniform and fine foam cells, improved spreadability, and a good molded product appearance can be obtained. .. Further, when the melt flow rate is 0.1 g/10 minutes or more, orientation-induced crystallization is less likely to occur when molding is performed, and the bubble wall is not particularly broken during extrusion sheet molding in the T-die molding method, and the appearance is improved. A molded product with excellent When the melt flow rate is 100.0 g/10 minutes or less, the melt tension becomes high, which is suitable for foaming.
The method for measuring MFR is the same as the method for measuring polypropylene resin (X) described above.

IV. Component of polypropylene resin composition, preparation method, use 1. Constituent Components of Polypropylene Resin Composition The constituent components of the polypropylene resin composition suitable for foam molding will be described in detail below.

(1) Blowing Agent It is preferable to further blend a blowing agent into the polypropylene resin composition of the present invention.
As the foaming agent, a well-known and publicly used foaming agent used for plastics and rubber can be used without any problem. Conventionally used foaming agents such as physical foaming agents, decomposable foaming agents (chemical foaming agents), and microcapsules containing a thermal expansion agent can be used.
As a physical blowing agent, for example, propane, butane, pentane, aliphatic hydrocarbons such as hexane, cyclopentane, alicyclic hydrocarbons such as cyclohexane, chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, dichlorodifluoromethane , Chloromethane, dichloromethane, chloroethane, dichlorotrifluoroethane, dichlorofluoroethane, chlorodifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, trichlorotrifluoroethane, dichlorotetrafluoroethane, chloro Examples thereof include halogenated hydrocarbons such as pentafluoroethane and perfluorocyclobutane, water, inorganic gases such as carbon dioxide gas and nitrogen, and combinations of two or more thereof.
Of these, aliphatic hydrocarbons such as propane, butane, and pentane and carbon dioxide gas are preferable because they are inexpensive and have high solubility in the polypropylene resin (X). Carbon dioxide gas is in a supercritical state at 7.4 MPa or higher and 31° C. or higher, and is in a state excellent in diffusion and solubility in the polymer.

When obtaining a polypropylene-based foam using a physical foaming agent, a cell regulator may be used if necessary. Examples of the foam control agent include inorganic decomposable foaming agents such as ammonium carbonate, sodium bicarbonate, ammonium bicarbonate and ammonium nitrite, azo compounds such as azodicarbonamide, azobisisobutyronitrile and diazoaminobenzene, N,N'-. Nitroso compounds such as dinitrosopentane methylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide, benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p,p'-oxybisbenzenesulfonyl semicarbazide, p- Degradable foaming agents such as toluenesulfonyl semicarbazide, trihydrazinotriazine and barium azodicarboxylate, inorganic powders such as talc and silica, acidic salts such as polyvalent carboxylic acid, reaction of polyvalent carboxylic acid with sodium carbonate or sodium bicarbonate Examples thereof include a mixture and the like, and these may be used alone or in combination.

When a polypropylene-based foam is obtained with a decomposable foaming agent (chemical foaming agent), examples of the decomposable foaming agent (chemical foaming agent) include a mixture of sodium bicarbonate and an organic acid such as citric acid, and azodicarbonamide. , Azo foaming agents such as barium azodicarboxylate, nitroso foaming agents such as N,N'-dinitrosopentamethylenetetramine, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, p,p' -Sulfohydrazide-based foaming agents such as oxybisbenzenesulfonyl hydrazide and p-toluenesulfonyl semicarbazide, and trihydrazinotriazine.
The blending amount of the foaming agent is preferably in the range of 0.05 to 6.0 parts by weight, more preferably 0.1 parts by weight, based on 100 parts by weight of the components (X), (Y), and (Z). 05 to 3.0 parts by weight, more preferably 0.5 to 2.5 parts by weight, particularly preferably 1.0 to 2.0 parts by weight.
When the blending amount of the foaming agent is 6.0 parts by weight or less, over-foaming does not occur, and it becomes easy to make the foam cells uniform and fine. On the other hand, when the blending amount of the foaming agent is 0.05 parts by weight or more, A large amount of gas is generated, which is preferable.
When using the cell regulator, the content of the cell regulator is 0.01 to 100 parts by weight in total of the components (X), (Y), and (Z). It is preferably in the range of 5 parts by weight.

(2) Other compounding agents In the polypropylene resin composition of the present invention, in addition to the components (X), (Y), and (Z), a foaming agent, and, if necessary, a cell regulator. , Other polymers, antioxidants, neutralizing agents, light stabilizers, ultraviolet absorbers, inorganic fillers, lubricants, antistatic agents, various additives such as metal deactivators, without impairing the purpose of the present invention. It can be blended in a range.
Other polymers include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene-based resins other than those described above, propylene-α-olefin copolymer (α-olefin has 4 or more carbon atoms), poly Polyolefin such as -4-methyl-1-pentene, olefin elastomer such as ethylene-propylene elastomer, or other monomer copolymerizable therewith, such as vinyl acetate, vinyl chloride, (meth)acrylic acid, (meth ) Copolymers such as acrylic acid esters and mixtures thereof can be mentioned.

Examples of the antioxidant include phenol-based antioxidants, phosphite-based antioxidants and thio-based antioxidants, and examples of the neutralizer include higher fatty acid salts such as calcium stearate and zinc stearate. Examples of the light stabilizer and the ultraviolet absorber include hindered amines, nickel complex compounds, benzotriazoles and benzophenones.
Further, examples of the inorganic filler include talc, calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate, and the like, and examples of the lubricant include higher fatty acid amides such as stearic acid amide.
Examples of antistatic agents include fatty acid partial esters such as glycerin fatty acid monoester, and examples of metal deactivators include triazines, phosphones, epoxies, triazoles, hydrazides, oxamides and the like. it can.

2. Method for preparing polypropylene-based resin composition As a method for preparing the polypropylene-based resin composition of the present invention, powdery or pelletized polypropylene resin (X), propylene-based block copolymer (Y), propylene-α-olefin. Examples thereof include a method of mixing the random copolymer (Z), the foaming agent, and other compounding agents used as necessary with a dry blend, a Henschel mixer (trade name), or the like. Alternatively, melt kneading may be performed in advance using a single-screw kneader, a twin-screw kneader, a kneader, or the like. However, when the chemical foaming agent is melt-kneaded at the same time, it is necessary to control the kneading temperature to a temperature lower than the decomposition temperature of the chemical foaming agent.
Further, depending on the situation, only the foaming agent may be separately fed at the time of manufacturing the polypropylene foam.

3. Uses The polypropylene resin composition of the present invention is used in various molding methods and uses that require high melt tension, such as injection molding (body), extrusion molding (body), bead foam molding (body), extrusion foam molding (body). ), injection foam molding (body), blow molding (body), injection blow molding (body), foam blow molding (body), deep drawing molding (body), thermoforming (body), etc. However, in particular, it can be suitably used in the field of foam molding in which the superiority or inferiority of the characteristics of the melt tension is most prominent.

4. Polypropylene-based resin (multilayer) foamed sheet The polypropylene-based resin foamed sheet obtained from the polypropylene-based resin composition (containing a foaming agent) of the present invention preferably has an average cell diameter of 500 μm or less, more preferably 400 μm or less, and 300 μm. The following is more preferable. It is preferable that the average cell diameter is 500 μm or less because appearance defects such as perforation do not occur in both the polypropylene foam sheet and the thermoformed body obtained by further thermoforming the sheet.
The polypropylene resin foam sheet according to the present invention preferably has an open cell rate of 30% or less, more preferably 20% or less, further preferably 15% or less, and particularly preferably 10% or less. When the open cell ratio is 30% or less, expansion of the foam cells in the foam sheet during thermoforming increases the thickness of the thermoformed body, which is preferable. It is also preferable because it also leads to the improvement of the heat insulating performance of the thermoformed body.
The thickness of the polypropylene resin foam sheet according to the present invention is not particularly limited, but is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm to 5 mm. The thickness of the foamed sheet formed by the T-die molding method is preferably about 0.3 mm to 3 mm, more preferably 0.5 mm to 2.0 mm.
The density of the polypropylene-based resin foamed sheet according to the present invention is not particularly limited, but generally, the lower the density, the more excellent the performance as a foam such as the weight reduction and the heat insulating property. Therefore, for example, 0.500 g/ cm ³ or less, preferably, 0.391 g / cm ³ or less, more preferably 0.300 g / cm ³ or less, more preferably, 0.265 g / cm ³ or less, and most preferably, 0.257 g / cm ³ or less is there.
Further, the expansion ratio of the polypropylene-based resin foam sheet according to the present invention is not particularly limited, but in general, the higher the expansion ratio, the more excellent the performance as a foam, such as the weight reduction and the heat insulating property. It is 8 times or more, preferably 2.3 times or more, more preferably 3.0 times or more, particularly preferably 3.4 times or more, and most preferably 3.5 times or more. In particular, the polypropylene-based resin foam sheet according to the present invention can achieve uniform and fine foam cells even at a high expansion ratio of 3.0 times or more by the T-die method.

Examples of the method for obtaining a polypropylene-based resin foam sheet include injection molding methods, thermoforming methods, extrusion molding methods, blow molding methods, bead foam molding methods, and other molding methods. The composition can be obtained by a known extrusion molding method in which the composition is melted by an extruder and extruded from a die provided at the tip of the extruder. The extruder may be either a single-screw extruder or a twin-screw extruder, and may be, for example, a tandem system in which a twin-screw extruder and a single-screw extruder are combined in a front stage and a rear stage.
In the case of physical foaming, a physical foaming agent such as carbon dioxide or butane is introduced (press-fitted) in the middle of the extruder cylinder. The die attached to the tip of the extruder may be a T die or a circular (circular) die.

In the case of a polypropylene resin multilayer foamed sheet, it can be obtained by coextrusion molding a foamed layer made of a polypropylene resin composition and a non-foamed layer made of a thermoplastic resin composition.
The polypropylene resin multilayer foamed sheet can be produced by a known co-extrusion method using a feed block or a multi-die using a plurality of extruders, an extrusion laminating method, or the like, but the co-extrusion method is preferable.
The non-foaming layer used for the polypropylene-based resin multilayer foamed sheet may be provided on any surface of the foaming layer, and the foaming layer is formed between two non-foaming layers (sandwich structure). You can also
The polypropylene-based resin multilayer foamed sheet provided with the non-foamed layer is excellent in strength, and by providing the non-foamed layer at least outside the foamed layer, it is also excellent in surface smoothness and appearance. Become. Furthermore, by using a functional thermoplastic resin for the non-foamed layer, it is possible to easily provide the polypropylene resin multilayer foamed sheet with additional functions such as antibacterial property, soft feeling, and scratch resistance. ,preferable.

As the thermoplastic resin constituting the thermoplastic resin composition used in the non-foamed layer, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, component (X), as long as the effects of the present invention are not impaired, Polypropylene and propylene-α-olefin copolymers, polyolefins such as poly-4-methyl-1-pentene, which may be the same as the respective components of (Y) and (Z), and olefin elastomers such as ethylene-propylene elastomers Or other monomers copolymerizable therewith, such as copolymers of vinyl acetate, vinyl chloride, (meth)acrylic acid, (meth)acrylic acid ester and the like, and mixtures thereof can be selected. ..
Among these, polypropylene and propylene-α-olefin copolymer are preferable from the viewpoints of recyclability, adhesiveness, heat resistance, oil resistance, rigidity and the like. As the propylene-α-olefin copolymer, a so-called impact-resistant polypropylene obtained by multi-stage polymerization of a propylene (co)polymer and an ethylene-propylene random copolymer in a plurality or in a single tank is used. It also includes a multi-stage polymer commonly referred to as a propylene block copolymer.

The thickness of the polypropylene resin multilayer foamed sheet is not particularly limited, but is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm to 5 mm. The thickness of the foamed sheet formed by the T-die molding method is preferably about 0.3 mm to 3 mm, more preferably 0.5 mm to 2.0 mm.
In addition, the total thickness of the non-foamed layer in the polypropylene-based resin multilayer foamed sheet should be 1 to 50%, more preferably 5 to 20% of the total thickness of the obtained polypropylene-based resin multilayer foamed sheet. Is desirable. When the thickness of the non-foamed layer is 50% or less, the growth of bubbles in the foamed layer is not hindered.

Further, the polypropylene-based resin (multilayer) foamed sheet according to the present invention has no problem even if the surface of the foamed sheet is subjected to surface treatment such as corona discharge treatment, flame treatment, and plasma treatment for printability and paintability. It doesn't matter.

5. Uses of Polypropylene-based Resin Foamed Sheet and Thermoformed Body A polypropylene-based resin (multilayer) foamed sheet according to the present invention and a molded body (thermoformed body) obtained by thermoforming the (multilayered) foamed sheet are uniform fine foam cells. It is excellent in appearance, thermoformability, impact resistance, light weight, rigidity, heat resistance, heat insulation, oil resistance, etc., so food containers such as trays, plates, cups, automobile door trims, automobile trunks, etc. It can be suitably used for vehicle interior materials such as mats, packaging, stationery, and building materials.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.
In Examples and Comparative Examples, various properties of the polypropylene-based resin composition, the polypropylene-based resin (multilayer) foamed sheet, and the components thereof were measured and evaluated according to the following evaluation methods. I used the one.

1. Evaluation method (1) Melt flow rate MFR:
The measurement was performed according to JIS K7210:1999, Annex A Table 1, Condition M (230° C., 2.16 kg load). The die has a diameter of 2.095 mm and a length of 8.000 mm. The unit is g/10 minutes.
(2) Melt tension MT:
The measurement was performed under the following conditions using a capillograph manufactured by Toyo Seiki Seisakusho.
・Capillary: diameter 2.0 mm, length 40 mm
・Cylinder diameter: 9.55 mm
・Cylinder extrusion speed: 20 mm/min ・Take-off speed: 4.0 m/min ・Temperature: 230°C
When MT is extremely high, the resin may be broken at a take-up speed of 4.0 m/min. In such a case, the take-up speed is reduced and the tension at the highest take-off speed is MT. And The unit is gram.
(3) Molecular weight distribution Mw/Mn and Mz/Mn:
It was determined by GPC measurement according to the method described above.
(4) 25° C. Para-xylene soluble component amount (CXS):
It was measured by the method described in the specification.
(5) mm fraction:
As described above, it was measured using a JSX-400, FT-NMR manufactured by JEOL Ltd. by the method described in paragraphs [0053] to [0065] of JP-A No. 2009-275207.
The unit is %.

(6) Branching index g ^' :
As described above, it was determined by GPC equipped with a differential refractometer (RI), a viscosity detector (Viscometer), and a light scattering detector (MALLS) as detectors.
(7) Strain hardening degree λmax:
The extensional viscosity was measured under the following conditions.
-Device: Ares manufactured by Rheometrics
・Jig: Extensive Viscosity Fixture manufactured by TA Instruments
・Measurement temperature: 180℃
・Strain rate: 0.1/sec
-Preparation of test piece: A sheet having a size of 18 mm x 10 mm and a thickness of 0.7 mm is formed by press molding.
The details of the calculation method of λmax are as described above.
(8) Melting peak temperature:
Using a differential operation calorimeter (DSC), once the temperature was raised to 200° C. to erase the thermal history, the temperature was lowered to 40° C. at a temperature lowering rate of 10° C./min, and the temperature rising rate was again set to 10° C./min. The temperature of the endothermic peak top at the time of measurement was defined as the melting peak temperature.
(9) Ratio of (Y-1) and (Y-2), ethylene content in (Y-2):
It was determined by the combination of the cross fractionation method and the FT-IR method described in the specification.
(10) Intrinsic viscosity of component (Y-2):
The CXS component of the propylene block copolymer (Y) was measured at a temperature of 135° C. using decalin as a solvent and using an Ubbelohde-type capillary viscometer. However, for the ethylene content of (Y-2) less than 15% by weight, the intrinsic viscosities of the (Y-1) component and the (Y) component as a whole were measured and determined by the calculation formula described in the specification.

(11) Density:
Test pieces were cut out from the polypropylene-based resin (multilayer) foamed sheets obtained in Examples and Comparative Examples, and the weight (g) of the test piece was divided by the volume (cm ³ ) obtained from the outer dimensions of the test piece. .. The density was determined by measurement according to JIS K7222.
(12) Open cell rate:
Test pieces were cut out from the polypropylene-based resin (multilayer) foamed sheets obtained in Examples and Comparative Examples, and measured using an air pycnometer (manufactured by Tokyo Science Co., Ltd.) according to the method described in ASTM D2856.
(13) Seat appearance evaluation:
For the appearance evaluation of the foamed sheet, the polypropylene-based resin (multilayer) foamed sheets obtained in Examples and Comparative Examples were evaluated according to the following criteria.
⊚: Bubble shape is fine and uniform, and the sheet appearance is beautiful.
◯: The bubble shape is uniform and the sheet appearance is beautiful.
Δ: Cohesion of bubbles is observed to some extent and the sheet appearance is inferior.
X: The coalescence of bubbles is remarkable and the appearance of the sheet is extremely poor.
(14) Drawdown resistance:
Test pieces of 300 mm×300 mm were cut out from the polypropylene-based resin (multilayer) foamed sheets obtained in Examples and Comparative Examples, and fixed to a frame having inner dimensions of 260 mm×260 mm. Using a sag tester manufactured by Misuzu Erie Co., Ltd., the sample was guided to a heating furnace in a tester in which heaters were vertically arranged and heated at an ambient temperature of 200° C., and the displacement of the central portion of the sample from the start of heating was sequentially measured by a laser beam. ..
As the sheet hangs down (displaces in the minus direction) with heating, it hangs up again due to stress relaxation (displaces in the plus direction) and then hangs down again. Therefore, the sheet position at the heating start point is A (mm) and the maximum rebound point position is B. The drawdown resistance was evaluated according to the following criteria, where (mm) and C (mm) are the positions 10 seconds after the maximum point T of return.
⊚: B−A≧0 mm and C−B≧−5 mm
◯: B-A≧−5 mm and C−B≧−10 mm (excluding the case of B−A≧0 mm and C−B≧−5 mm)
Δ: B−A≧−5 mm and C−B<−10 mm, or B−A<−5 mm and C−B≧−10 mm
X: B-A<-5 mm and C-B<-10 mm
Here, B−A≧−5 mm means that the sheet is tensioned at the time of molding the container, and a beautiful appearance can be formed without wrinkles, and C−B≧−10 mm is good. This means that the molding time range for obtaining a flexible container is sufficiently wide.

2. Materials used (1) Polypropylene resin (X) having a long-chain branched structure
The polymer (PP-1) produced in Production Example 1 below and the polymer (PP-2) produced in Production Example 2 below were used.

[Production Example 1 (Production of PP-1)]
<Synthesis example 1 of catalyst component (A)>
Synthesis of dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium by the following procedure (component [A-1 ] (Synthesis of complex 1) was carried out.
(I) Synthesis of 4-(4-i-propylphenyl)indene To a 500 ml glass reaction vessel, 15 g (91 mmol) of 4-i-propylphenylboronic acid and 200 ml of dimethoxyethane (DME) were added, and 90 g of cesium carbonate ( A solution of 0.28 mol) and 100 ml of water was added, 13 g (67 mmol) of 4-bromoindene and 5 g (4 mmol) of tetrakistriphenylphosphinopalladium were added in that order, and the mixture was heated at 80° C. for 6 hours.
After allowing to cool, the reaction mixture was poured into 500 ml of distilled water, transferred to a separating funnel and extracted with diisopropyl ether. The ether layer was washed with saturated saline and dried over sodium sulfate. Sodium sulfate was filtered, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column to obtain 15.4 g (yield 99%) of 4-(4-i-propylphenyl)indene colorless liquid.

(Ii) Synthesis of 2-bromo-4-(4-i-propylphenyl)indene 4-(4-i-propylphenyl)indene 15.4 g (67 mmol) and distilled water 7.2 ml in a 500 ml glass reaction vessel. , DMSO (200 ml) and N-bromosuccinimide (17 g, 93 mmol) were gradually added thereto. The mixture was stirred at room temperature for 2 hours, poured into 500 ml of ice water, and extracted with 100 ml of toluene three times. The toluene layer was washed with saturated brine, 2 g (11 mmol) of p-toluenesulfonic acid was added, and the mixture was heated under reflux for 3 hours while removing water. The reaction mixture was allowed to cool, washed with saturated brine and dried over sodium sulfate. Sodium sulfate was filtered, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column to obtain 19.8 g (yield 96%) of 2-bromo-4-(4-i-propylphenyl)indene as a yellow liquid. ..

(Iii) Synthesis of 2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indene To a 500 ml reaction vessel made of glass, 6.7 g (82 ml mol) of 2-methylfuran and 100 ml of DME were added. , Cooled to -70°C in a dry ice-methanol bath. 51 ml (81 mmol) of a 1.59 mol/L n-butyllithium-n-hexane solution was added dropwise thereto, and the mixture was stirred as it was for 3 hours. It cooled at -70 degreeC and the solution of triisopropyl borate 20ml (87 mmol) and DME50ml was dripped there. After the dropping, the mixture was stirred overnight while gradually returning to room temperature.
After hydrolyzing by adding 50 ml of distilled water to the reaction mixture, a solution of 223 g of potassium carbonate and 100 ml of water and 19.8 g (63 mmol) of 2-bromo-4-(4-i-propylphenyl)indene were sequentially added, and at 80°C. The mixture was heated and reacted for 3 hours while removing low boiling components.
After allowing to cool, the reaction mixture was poured into 300 ml of distilled water, transferred to a separating funnel and extracted three times with diisopropyl ether. The ether layer was washed with saturated brine and dried over sodium sulfate. Sodium sulfate was filtered off, the solvent was distilled off under reduced pressure, and the residue was purified on a silica gel column to give 2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indene as a colorless liquid 19.6 g ( Yield 99%) was obtained.

(Iv) Synthesis of dimethylbis(2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl)silane In a 500 ml glass reaction vessel, 2-(5-methyl-2- Furyl)-4-(4-i-propylphenyl)indene (9.1 g, 29 mmol) and THF (200 ml) were added, and the mixture was cooled to -70°C in a dry ice-methanol bath. 17 ml (28 mmol) of a 1.66 mol/L n-butyllithium-n-hexane solution was added dropwise thereto, and the mixture was stirred as it was for 3 hours. The mixture was cooled to −70° C., 0.1 ml (2 mmol) of 1-methylimidazole and 1.8 g (14 mmol) of dimethyldichlorosilane were sequentially added, and the mixture was stirred overnight while gradually returning to room temperature. Distilled water was added to the reaction mixture, the mixture was transferred to a separating funnel and washed with saline until neutral, sodium sulfate was added, and the reaction mixture was dried. Sodium sulfate was filtered off, the solvent was distilled off under reduced pressure, and the residue was purified on a silica gel column to give dimethyl bis(2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl)silane. 8.6 g (88% yield) of a yellow solid was obtained.

(V) Synthesis of dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium In a 500 ml glass reaction vessel, Dimethylbis(2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl)silane (8.6 g, 13 mmol) and diethyl ether (300 ml) were added, and the mixture was dried at -70°C in a dry ice-methanol bath. Cooled down. 15 ml (25 mmol) of a 1.66 mol/L n-butyllithium-n-hexane solution was added dropwise thereto, and the mixture was stirred for 3 hours. The solvent of the reaction mixture was distilled off under reduced pressure, 400 ml of toluene and 40 ml of diethyl ether were added, and the mixture was cooled to -70°C in a dry ice-methanol bath. Thereto, 4.0 g (13 mmol) of hafnium tetrachloride was added. Then, the mixture was stirred overnight while gradually returning to room temperature.
The solvent was distilled off under reduced pressure and recrystallized from dichloromethane-hexane to give dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl. }] Hafnium racemate was obtained as yellow crystals (7.6 g, yield 65%).
Identification values of the obtained racemate by ¹ H-NMR are shown below.
¹ H-NMR (C ₆ D ₆ ) identification result Racemate: δ 0.95 (s, 6H), δ 1.10 (d, 12H), δ 2.08 (s, 6H), δ 2.67 (m, 2H). , Δ 5.80 (d, 2H), δ 6.37 (d, 2H), δ 6.74 (dd, 2H), δ 7.07 (d, 2H), δ 7.13 (d, 4H), δ 7.28 ( s, 2H), δ7.30 (d, 2H), δ7.83 (d, 4H).

<Synthesis example 2 of catalyst component (A)>
Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium: (Synthesis of component [A-2] (complex 2)):
The synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium was carried out by the method described in Example 1 of JP-A No. 11-240909. It carried out similarly to.

<Catalyst synthesis example 1>
(I) Chemical treatment of ion-exchangeable layered silicate 96% sulfuric acid (668 g) was added to 2,264 g of distilled water in a separable flask, and then montmorillonite as a layered silicate (Ben clay SL manufactured by Mizusawa Chemical Industry Co., Ltd.: average) 400 g (particle size 19 μm) was added. The slurry was heated at 90°C for 210 minutes. Distilled water (4,000 g) was added to the reaction slurry and then filtered to obtain 810 g of cake-like solid.
Next, 432 g of lithium sulfate and 1,924 g of distilled water were added to a separable flask to prepare a lithium sulfate aqueous solution, and the whole amount of the cake-like solid was charged. This slurry was reacted at room temperature for 120 minutes. Distilled water (4 L) was added to this slurry, which was then filtered, washed with distilled water to a pH of 5 to 6, and filtered to obtain 760 g of a cake-like solid.
The obtained solid was preliminarily dried at 100° C. for one day under a nitrogen stream, coarse particles having a diameter of 53 μm or more were removed, and further dried under reduced pressure at 200° C. for 2 hours to obtain 220 g of chemically treated smectite.
The composition of this chemically treated smectite is Al: 6.45% by weight, Si: 38.30% by weight, Mg: 0.98% by weight, Fe: 1.88% by weight, Li: 0.16% by weight, It was Al/Si=0.175 [mol/mol].

(Ii) Preparation of Catalyst and Prepolymerization 20 g of the chemically treated smectite obtained above was placed in a three-necked flask (volume: 1 L), heptane (132 mL) was added to form a slurry, and triisobutylaluminum (25 mmol: concentration) was added to the slurry. A 143 mg/mL heptane solution (68.0 mL) was added, and the mixture was stirred for 1 hour, washed with heptane until the residual liquid ratio became 1/100 or less, and heptane was added so that the total liquid volume was 100 mL.
In another flask (volume 200 mL), rac-dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-) prepared in Synthesis Example 1 of the catalyst component (A) was used. 4-(4-i-Propylphenyl)indenyl}]hafnium (210 μmol) was dissolved in toluene (42 mL) (Solution 1), and the catalyst component (A) was synthesized in another flask (volume 200 mL). The rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (90 μmol) prepared in Example 2 was dissolved in toluene (18 mL). ).
Triisobutylaluminum (0.84 mmol: 1.2 mL of a heptane solution having a concentration of 143 mg/mL) was added to a 1 L flask containing the chemically treated smectite, and then the above solution 1 was added and stirred at room temperature for 20 minutes. Then, after further adding triisobutylaluminum (0.36 mmol: 0.50 mL of a heptane solution having a concentration of 143 mg/mL), the above solution 2 was added, and the mixture was stirred at room temperature for 1 hour.
Then, 338 mL of heptane was added, and this slurry was introduced into a 1 L autoclave.
After setting the internal temperature of the autoclave to 40° C., propylene was fed at a rate of 10 g/hour to carry out preliminary polymerization while maintaining 40° C. for 4 hours. Then, the propylene feed was stopped and the residual polymerization was carried out for 1 hour. After removing the supernatant of the obtained catalyst slurry by decantation, triisobutylaluminum (6 mmol: 17.0 mL of a heptane solution having a concentration of 143 mg/mL) was added to the remaining portion and stirred for 5 minutes.
The solid was dried under reduced pressure for 1 hour to obtain 52.8 g of a dry prepolymerized catalyst. The prepolymerization ratio (value obtained by dividing the prepolymerized polymer amount by the solid catalyst amount) was 1.64.
Hereinafter, this is referred to as "preliminary polymerization catalyst 1".

<Polymerization>
After thoroughly replacing the inside of the stirring autoclave having an inner volume of 200 liters with propylene, 40 kg of sufficiently dehydrated liquefied propylene was introduced. After adding 9.5 liters of hydrogen (as a standard volume) and 470 ml (0.12 mol) of a triisobutylaluminum/n-heptane solution, the internal temperature was raised to 70°C. Then, 1.9 g of the prepolymerized catalyst 1 (by weight excluding the prepolymerized polymer) was press-fitted with argon to start the polymerization, and the internal temperature was maintained at 70°C. After 2 hours, 100 ml of ethanol was injected under pressure, unreacted propylene was purged, and the inside of the autoclave was replaced with nitrogen to terminate the polymerization.
The obtained polymer was dried under a nitrogen stream at 90° C. for 1 hour to obtain 18.4 kg of a polymer (hereinafter referred to as “PP-1”).
The catalytic activity was 9200 (g-PP/g-cat). The MFR was 9.3 g/10 minutes.

[Production Example 2 (Production of PP-2)]
The procedure of Production Example 1 was repeated, except that 4.8 liters of hydrogen was added and 2.3 g (by weight excluding the prepolymerized polymer) of the prepolymerized catalyst 1 used. 16.1 kg of a polymer (hereinafter referred to as "PP-2") was obtained.
The catalytic activity was 6980 (g-PP/g-cat). The MFR was 1.9 g/10 minutes.

[Production of PP-1 to PP-2 Pellets (X1) to (X2)]
To 100 parts by weight of the polymers (PP-1 to PP-2) produced in Production Examples 1 to 2, tetrakis[methylene-3-(3',5'-di-t] which is a phenolic antioxidant is used. -Butyl-4'-hydroxyphenyl)propionate]methane (trade name: IRGANOX1010, manufactured by BASF Japan Ltd.) 0.125 parts by weight, tris(2,4-di-t) which is a phosphite antioxidant. -Butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.) 0.125 parts by weight is mixed and mixed for 3 minutes at room temperature using a high-speed stirring mixer (Henschel mixer, trade name). Then, the mixture was melt-kneaded with a twin-screw extruder to obtain polypropylene resin (X) pellets (X1) to (X2).
As the twin-screw extruder, KZW-25 manufactured by Techno Bell Co. was used, the screw rotation speed was 400 RPM, and the kneading temperature was set to 80, 160, 210, 230 from the bottom of the hopper (hereinafter, the same temperature up to the die outlet) °C. did.
The obtained pellets (X1) to (X2) were evaluated for MFR, CXS, ¹³ C-NMR, GPC, branching index, MT and extensional viscosity. The evaluation results are shown in Table 1.

(2) Propylene-based block copolymer (Y)
The propylene block copolymer (Y1) produced in Production Example 3 below was used.

[Production Example 3: Production of propylene block copolymer (Y1)]
<Catalyst analysis method>
The following methods were used for the analysis of the catalyst component, solid catalyst, and prepolymerized catalyst.
Ti content (wt%) A sample was accurately weighed, hydrolyzed, and then measured by a colorimetric method. For the sample after prepolymerization, the content was calculated using the weight excluding the prepolymerized polymer.
・Silicon compound content (wt%)
The sample was accurately weighed and decomposed with methanol. The silicon compound concentration in the obtained methanol solution was determined by comparison with a standard sample using gas chromatography. The content of the silicon compound contained in the sample was calculated from the concentration of the silicon compound in methanol and the weight of the sample. For the sample after prepolymerization, the content was calculated using the weight excluding the prepolymerized polymer.

<Preparation of prepolymerization catalyst B1>
(1) Preparation of Solid Component B1 A 10 L capacity autoclave 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 was added and 1 L of TiCl ₄ was slowly added. The temperature was gradually raised to 90° C. and 50 ml of di-n-butyl phthalate was introduced. Then, the temperature was raised to 110° C. and the reaction was performed for 3 hours. The reaction mixture was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total liquid volume to 2L. At room temperature, 1 L of TiCl ₄ was added, the temperature was raised to 110° C., and the reaction was performed for 2 hours. The reaction mixture was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total liquid volume to 2L. At room temperature, 1 L of TiCl ₄ was added, the temperature was raised to 110° C., and the reaction was performed for 2 hours. The reaction mixture was thoroughly washed with purified toluene. Further, using purified n-heptane, toluene was replaced with n-heptane to obtain a slurry of solid component B1. A part of this slurry was sampled and dried. As a result of analysis, the Ti content of the solid component B1 was 2.7 wt %.

(2) Preparation of Solid Catalyst B1 Next, the autoclave with a capacity of 20 L equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the slurry of the solid component B1 was introduced as a solid component. Purified n-heptane was introduced to adjust the concentration of the solid component to 25 g/L. 50 ml of SiCl ₄ was added, and the reaction was performed at 90° C. for 1 hr. The reaction mixture was washed thoroughly with purified n-heptane.
Then, purified n-heptane was introduced to adjust the liquid level to 4 L. Here, dimethyl divinyl silane 30 ml, 80 g was added _{t-BuMeSi (OMe) 2 30ml} , the n- heptane dilution of _Et 3 Al as _Et 3 Al, were 2hr reaction at 40 ° C.. The reaction mixture was thoroughly washed with purified n-heptane to obtain a solid catalyst B1 formed by treating the solid component B1 with an organic silicon. A part of the obtained slurry of the solid catalyst B1 was sampled, dried and analyzed. The solid catalyst B1 contained 1.2 wt% of Ti and 8.9 wt% of t-BuMeSi(OMe) ₂ .

(3) Preliminary Polymerization Using the solid catalyst B1 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 catalyst to 20 g/L. After cooling the slurry to 10 ° C., 10 g was added n- heptane dilution of _Et 3 Al as _Et 3 Al, were fed over 4hr of propylene 280 g. After the supply of propylene was completed, the reaction was further continued for 30 minutes. Then, the gas phase was thoroughly replaced with nitrogen, and the reaction mixture was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried to obtain a prepolymerized catalyst B1. The prepolymerized catalyst B1 contained 2.5 g of polypropylene per 1 g of the solid catalyst. As a result of analysis, the portion of the prepolymerization catalyst B1 excluding polypropylene contained 1.0 wt% of Ti and 8.3 wt% of t-BuMeSi(OMe) ₂ .

The polymerization was carried out using a two-tank continuous gas phase polymerization reactor. The first polymerization tank for carrying out the first step of the sequential polymerization and the second polymerization tank for carrying out the second step are both fluidized bed reactors having an internal volume of 230 liters. The raw material gas used was one that was sufficiently purified.

(First step: production of propylene polymer)
Regarding the gas composition of the first polymerization tank, propylene and nitrogen were continuously supplied so that the partial pressure of propylene was 1.8 MPaA and the total pressure of the polymerization tank was 3.0 MPaG. Further, hydrogen as a molecular weight control agent was continuously supplied so that the molar ratio of hydrogen/propylene was 0.020. The polymerization temperature was controlled to be 60°C. Et ₃ Al was supplied to this first polymerization tank at 4.0 g/h, and the above-mentioned prepolymerization catalyst B1 was further added so that the production rate of the propylene polymer in the first polymerization tank was 17.5 kg/h. It was continuously supplied to produce a propylene homopolymer. The powder (propylene polymer) produced in the first polymerization tank was continuously extracted so that the powder holding amount in the polymerization tank was 40 kg, and continuously transferred to the second polymerization tank. When a part of the powder transferred from the first polymerization tank to the second polymerization tank was sampled and analyzed, the MFR was 20.0 g/10 minutes. In addition, when measuring the MFR, tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane (commercial product) was added to the sample propylene polymer. Name: IRGANOX1010, manufactured by BASF Japan Ltd., tris(2,4-di-t-butylphenyl)phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.), calcium stearate, each in an appropriate amount (500 wtppm). To add, these were put in a plastic bag, shaken by hand with the bag up and down, left and right, and the contents were thoroughly mixed (dry blended) and then measured.
Further, MPaG is a gauge pressure based on atmospheric pressure, and has a relationship of XX [MPaG]=XX+0.10133 [MPaA] with MPaA (absolute pressure) based on vacuum pressure.

(Second step: production of propylene-ethylene copolymer)
Regarding the gas composition of the second polymerization tank, propylene, ethylene, and nitrogen were continuously supplied so that the partial pressure of propylene was 1.15 MPaA, the partial pressure of ethylene was 0.35 MPaA, and the total pressure of the polymerization tank was 2.5 MPaG. Supplied. Further, hydrogen as a molecular weight control agent was continuously supplied so that the molar ratio of hydrogen/(propylene+ethylene) was 260 ppm. The polymerization temperature was controlled to be 70°C. Further, as a polymerization inhibitor, ethanol was continuously supplied at 2.0 g/h to produce a propylene-ethylene copolymer. As for the powder (the propylene-based block copolymer, which is a multistage polymer composed of propylene polymer and propylene-ethylene copolymer), the production of which has been completed in the second polymerization tank, the powder holding amount in the polymerization tank is 60 kg. It was continuously extracted into a vessel. Nitrogen gas containing water was supplied to the vessel to stop the reaction, and thus a propylene-based block copolymer (Y1) was obtained.

[Production of Propylene Block Copolymer (Y) Pellets]
1,3,5-Tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate (based on 100 parts by weight of the propylene block copolymer (Y1) obtained in Production Example 3 Trade name: Cyanox 1790, manufactured by Nippon Cytec Industries Co., Ltd. 0.05 parts by weight, tris(2,4-di-t-butylphenyl)phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Co., Ltd.) 10 parts by weight and 0.05 parts by weight of calcium stearate were mixed and mixed for 3 minutes at room temperature using a high-speed stirring mixer (Henschel mixer, trade name). Then, the mixture was melt-kneaded with a twin-screw extruder, extruded, passed through a cold water tank, and then the strand was cut with a strand cutter to obtain pellets.
The twin-screw extruder used was KZW-25 manufactured by Techno Bell, the screw rotation speed was 300 RPM, and the kneading temperature was 80, 160, 180, 200, 200, 200, 210, 210, 210°C from below the hopper (die. Exit).
As a result of analyzing the pellets of the obtained propylene block copolymer (Y1), MFR was 1.2 g/10 minutes, and the propylene-ethylene copolymer (Y-2) in the propylene block copolymer (Y) was found. Content of 28.0% by weight, ethylene content in propylene-ethylene copolymer (Y-2) is 26.0% by weight, melting peak temperature of propylene-based block copolymer (Y) is 160.0°C, The intrinsic viscosity of the propylene-ethylene copolymer (Y-2) was 9.4 dl/g.
The pellets of the propylene block copolymer (Y1) are also referred to as pellets (Y1) of the component (Y).

(3) Propylene-α-olefin random copolymer (Z)
As the propylene-α-olefin random copolymer (Z) of the present invention, a commercially available grade can be used.
(Z1) Wintech WMH02 (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: metallocene catalyst, melting peak temperature: 152° C., MFR: 20 g/10 minutes, ethylene content: 0.5 wt%
(Z2) Wintech WMG03 (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: metallocene catalyst, melting peak temperature: 142° C., MFR: 30 g/10 minutes, ethylene content: 0.9% by weight
(Z3) Wintech WSX03 (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: metallocene catalyst, melting peak temperature: 125° C., MFR: 25 g/10 minutes, ethylene content: 3.4 wt%

(4) Propylene homopolymer (H1) Novatec PP MA1B (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: Ziegler-Natta catalyst, melting peak temperature: 158° C., MFR: 20 g/10 minutes

[Example 1]
A mixture 100 in which the weight ratio of the pellets (X1) of the component (X), the pellets (Y1) of the component (Y), and the pellets (Z1) of the component (Z) was 35:15:50 to obtain a foamed layer. By weight, 0.5 parts by weight of a chemical foaming agent (trade name: Hydrocelol CF40E-J, manufactured by Nippon Boehringer Ingelheim Co., Ltd.) as a cell adjuster are uniformly stirred and mixed by a ribbon blender, and physically mixed in the middle of the barrel. It was charged into an extruder having a screw diameter of 65 mm and having a barrel hole for injecting a foaming agent.
While setting the cylinder temperature of the extruder at 250° C. and the screw rotation speed at 105 rpm, the resin is heated and melted to be plasticized and the bubble control agent is decomposed, and 0.45 part by weight of carbon dioxide is added to 100 parts by weight of the mixture. In a part, the mixture was pressed and kneaded to obtain a polypropylene resin composition for foam molding.
The polypropylene resin composition for foam molding was cooled in the latter stage of the extruder so that the final resin temperature was 205°C.
Further, in order to obtain a non-foamed layer, a screw diameter 40 mmΦ extruder was used, and a propylene-ethylene block copolymer resin (manufactured by Nippon Polypro Co., Ltd., trade name: Novatec PP, grade name “BC3BRFA”, MFR=13 g/10 min. ) 100 parts by weight of a thermoplastic resin composition is charged, heated and melted at 220° C., and then cooled to 180° C., together with the polypropylene resin composition for foam molding, through a feed block, a T die (gap= 0.4 mm) was co-extruded into the atmosphere at a rate of 83 kg/hr into a polypropylene resin multi-layer foamed sheet having a two-kind three-layer constitution of non-foamed layer-foamed layer-non-foamed layer.
While cooling the foam with a cooling roll and an air knife, the foam was extended by pulling a pinch roll to adjust the thickness and form a foam sheet having a thickness of 1.54 mm.
The obtained multilayer foamed sheet had a layer structure in which the thickness of non-foamed layer:foamed layer:non-foamed layer was 3.2:93.6:3.2, and the density was 0.261 g/cm ³ , continuous. The appearance was good with a bubble ratio of 44.7%. Table 2 shows the evaluation results of the foamed sheet.

[Examples 2 to 5]
Pellets of component (X), component (Y) and component (Z) were mixed in the types and weight ratios shown in Table 2 and 0.5 part by weight of the chemical foaming agent described in Example 1 as a cell regulator. Then, a multilayer foam sheet was produced by the same method as described in Example 1. The evaluation results of the obtained foamed sheet are shown in Table 2.

[Comparative Example 1]
Foaming in the same manner as described in Example 1 except that only the pellets (X1) of the component (X) and the pellets (Y1) of the component (Y) were used in a weight ratio of 70:30 to obtain the foamed layer. Got the sheet. The foamed sheet had a remarkably high open cell rate and was inferior in the appearance of the sheet.

[Comparative example 2]
To obtain the foamed layer, the weight ratio of the pellets (X1) of the component (X), the pellets (Y1) of the component (Y) and the polypropylene homopolymer (H1) which is outside the scope of the claims of the present application is 35:15: A foamed sheet was obtained in the same manner as in Example 1, except that the foamed sheet was used. The foamed sheet had a remarkably high open cell ratio, was inferior in the appearance of the sheet, and did not reach the target of the sheet thickness and the expansion ratio. Regarding this, since the independence of the sheet is extremely low, it is considered that carbon dioxide was diffused from the surface of the sheet to the atmosphere during foaming, and the sheet thickness and the expansion ratio did not increase.

[Examples 6 to 7]
Pellets of component (X), component (Y) and component (Z) were mixed in the types and weight ratios shown in Table 3 and 0.75 part by weight of the chemical foaming agent described in Example 1 as a cell regulator. Then, a multilayer foam sheet was produced by the same method as described in Example 1. In Examples 6 to 7, the thickness of the multilayer foam sheet was changed to the value shown in Table 3. The evaluation results of the obtained foamed sheet are shown in Table 3.

The polypropylene-based resin composition of the present invention, the polypropylene-based resin (multilayer) foam sheet obtained therefrom, and the thermoformed body using the foamed sheet have uniform fine foam cells, and have an appearance, thermoformability, and impact resistance. , Light weight, rigidity, heat resistance, heat insulation, oil resistance, etc., food containers such as trays, plates, cups, car door trims, car interior mats such as car trunk mats, packaging, stationery, building materials, etc. It can be used favorably and has an extremely high industrial value.

Claims (8)

The polypropylene resin (X) having the following characteristics (X-i) to (X-iv) and having a long-chain branched structure is 67.5 to 2.5% by weight,
Propylene, which is a multistage polymer having the following properties (Yi) to (Yv) and consisting of a propylene (co)polymer (Y-1) and a propylene-ethylene copolymer (Y-2): 2.5 to 67.5% by weight of the block copolymer (Y), and a propylene-α-olefin random copolymer (Z) having the following characteristics (Z-i) to (Z-ii): 10-75% by weight
A polypropylene-based resin composition characterized by containing (however, the total of (X), (Y), and (Z) is 100% by weight).
(X-i) MFR is 0.1 to 30.0 g/10 minutes.
(X-ii) The molecular weight distribution Mw/Mn by GPC is 3.0 to 10.0, and Mz/Mw is 2.5 to 10.0.
(X-iii) Melt tension (MT) (unit: g) is
log(MT)≧−0.9×log(MFR)+0.7, or MT≧15
To meet any of the above.
(X-iv) The amount of the para-xylene soluble component at 25°C (CXS) is less than 5.0% by weight based on the total weight of the polypropylene resin (X).
The ratio of (Yi) (Y-1) to (Y-2) is such that (Y-1) is 50 to 99% by weight and (Y-2) is 1 to 50% by weight (provided that propylene is used. The total weight of the system block copolymer (Y) is 100% by weight).
(Y-ii) The MFR of the propylene block copolymer (Y) is 0.1 to 200.0 g/10 minutes.
(Y-iii) The melting peak temperature of the propylene block copolymer (Y) exceeds 155°C.
(Y-iv) The ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 60% by weight (however, the total weight of the constituent monomers of the propylene-ethylene copolymer (Y-2) is 100% by weight).
(Yv): The intrinsic viscosity of propylene-ethylene copolymer (Y-2) in decalin at 135° C. is 5.3 dl/g or more.
(Z-i) Polymerized with a metallocene catalyst.
(Z-ii) The melting peak temperature measured by DSC is 155°C or lower. The polypropylene-based resin composition according to claim 1, wherein the polypropylene resin (X) has the following characteristics (X-v).
(Xv): The branching index g ^′ when the absolute molecular weight Mabs is 1,000,000 is 0.30 or more and less than 0.95. The polypropylene resin composition according to claim 2, wherein the polypropylene resin (X) has the following characteristics (X-vi).
(X-vi): The mm fraction of 3 chains of propylene units by ¹³ C-NMR is 95% or more. A polypropylene resin composition for foam molding, comprising 0.05 to 6.0 parts by weight of a foaming agent based on 100 parts by weight of the polypropylene resin composition according to claim 1. A polypropylene-based resin foam sheet, which is obtained by extruding the polypropylene-based resin composition for foam molding according to claim 4. A polypropylene-based resin multilayer foamed sheet, which is obtained by coextruding the polypropylene-based resin foamed sheet according to claim 5 and a non-foamed layer made of a thermoplastic resin composition. A molded article, which is obtained by thermoforming the polypropylene-based resin foam sheet according to claim 5 or the multilayer foam sheet according to claim 6. The polypropylene resin composition according to any one of claims 1 to 3 or the polypropylene resin composition for foam molding according to claim 4, is injection-molded, thermoformed, extruded, blow-molded or beads. A molded article obtained by molding by any one of the foam molding methods.