JP2015040213A - Polypropylene resin composition for extrusion foam molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin composition suitable for extrusion foam molding capable of forming foam cells having a high closed cell rate (a low open cell ratio) and a dense and uniform size by achieving both cell formation during foaming and cell breakage prevention during spreading even under the conditions where the extrusion rate is high and the molding speed is high.SOLUTION: There is provided a polypropylene resin composition for extrusion foam molding or the like which comprises 5 to 99 wt.% of a polypropylene (X) satisfying the characteristics (X-i) to (X-iv), 1 to 95 wt.% of an impact copolymer (Y) composed of a propylene (co)polymer satisfying the characteristics (YH-i) to (YH-ii) and a propylene-ethylene copolymer (YC) satisfying the characteristics (YC-i) to (YC-ii) and satisfies the characteristics (X-i) to (Z-ii).

Description

  TECHNICAL FIELD The present invention relates to a polypropylene resin composition suitable for extrusion foam molding, and more specifically, a polypropylene resin composition for extrusion foam molding capable of forming a foam cell having a high closed cell ratio, a dense and uniform size. Further, the present invention relates to a foam sheet manufactured using the resin composition, and a molded body obtained by thermoforming the foam sheet.

One of the important molding methods for polypropylene is foam molding. Various molded products obtained by extrusion foaming or injection foaming have excellent properties such as heat insulation, sound insulation, cushioning and energy absorption, and are used in a wide range of applications. In recent years, in particular, from the viewpoint of environmental problems, weight reduction of materials and reduction of environmental burden have become important development factors, and further improvement of foaming characteristics is desired for the resin as a raw material. .
In general, polypropylene has a linear molecular structure and a standard molecular weight distribution, and thus has low melt tension and is difficult to perform foam molding. In order to compensate for this drawback, various technological developments have been made in the past as methods for improving the melt tension of polypropylene.
One of the representative methods is a method of introducing a long chain branch by generating a radical. Long-chain branching refers to a branched structure with molecular chains having several tens or more main chain carbon atoms and several hundreds or more in molecular weight, and is considered to have an effect of improving melt tension. As specific methods, a method using high-energy ionizing radiation (see Patent Document 1), a method using organic peroxide (see Patent Document 2), and the like are disclosed.
However, the method using high energy ionizing radiation requires special equipment for using the radiation, and the manufacturing cost is inevitably high. In addition, because radicals generated by high-energy ionizing radiation remain, problems such as yellowing occur, and quality problems such as changes in physical properties over time and unstableness. ing. In addition, the method using organic peroxide has quality problems such as contamination, odor, and yellowing due to decomposition products of organic peroxide, and the organic oxide is unstable. There is a big problem in terms of safety at the time.

As another method for improving the melt tension of polypropylene, there is a method of introducing an extremely high molecular weight component. Specific methods include a method of producing an ultrahigh molecular weight component by multistage polymerization (see Patent Documents 3 and 4), a method of producing an ultrahigh molecular weight polyethylene component by preliminary polymerization (see Patent Document 5), and the like. It has been.
However, the polypropylene produced by such a method has a considerably lower melt tension than polypropylene having a long chain branch, and therefore the foaming characteristics are not satisfactory and the applicable range is limited. I have a problem.
In order to solve such problems and problems, development of a technique for forming a long chain branch without generating a radical has been advanced (see Patent Documents 6 to 9). In this technique, a macromonomer having a terminal unsaturated bond is produced by polymerizing a monomer using a metallocene catalyst having a specific structure, and copolymerized with propylene to form a long chain branch. By these methods, problems such as odor caused by radical generation could be solved. Even if it can be made high, even if the cell formation during foaming is good, the spreadability is low, so the cell breaks down during sheet formation, the appearance of the sheet surface deteriorates, or the fluidity becomes low There is a problem that the extrusion rate cannot be increased and productivity is deteriorated. In particular, it is a big problem that the formation of foamed cells and the prevention of cell breakage at the time of spreading cannot be achieved at a high extrusion rate and a high molding speed.

From the viewpoint of developing a resin composition suitable for foam molding, a method of blending a plurality of polypropylenes (see Patent Documents 10 to 14) is disclosed.
However, although the patent documents 10 to 14 disclose blends of various polypropylenes, it is difficult to say that sufficient foaming characteristics are obtained. In particular, there is no improvement for the problems such as insufficient melt tension, insufficient fluidity, and poor appearance that occur when introducing long-chain branches using macromonomers. To reduce the cost.

Japanese Patent Laid-Open No. 62-121704 JP 2001-524565 A WO99 / 077752 JP 2001-335666 A WO97 / 14725 publication JP-T-2001-525460 JP 2009-275207 A JP 2009-293020 A JP 2009-299029 A JP 2001-226510 A JP 2002-356573 A JP 2010-121054 A JP 2009-275210 A JP 2011-068819 A

  An object of the present invention is to solve the above problems and problems in view of the current state of the prior art, and to provide a polypropylene resin composition suitable for extrusion foam molding. Specifically, even under conditions where the extrusion rate is high and the molding speed is high, by combining the formation of cells during foaming and the prevention of cell destruction during spreading, the closed cell ratio is high (low open cell ratio), and the size is high. The present invention provides a polypropylene resin composition for extrusion foam molding capable of forming a foam cell having a uniform quality, and further, by using the resin composition, a high-quality foam sheet and foam molded article are produced. It is to provide a method.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in remarkably enhancing the extrusion foaming characteristics by blending which requires a specific long-chain branched polypropylene and a specific impact copolymer. Specifically, by finding the optimal balance between melt tension and spreadability suitable for extrusion foam molding, we succeeded in achieving both the formation of cells during foaming and the surface formation of molded products during extrusion.

In general, in the phenomenon of resin foaming, a resin having a higher melt tension is considered desirable from the viewpoint that a thin partition can be firmly maintained during the formation and expansion of cells. On the other hand, in the extrusion molding, an operation of extending the resin raw material extruded from the die is important between the die and the take-up roll. At this time, too high melt tension acts to lower the spreadability, induces defects and disturbances in the sheet and film, and causes undesirable phenomena such as bubble destruction and surface roughness.
Therefore, in extrusion foam molding, the higher the melt tension, the better, and the idea that a specific value is preferable arises. On the other hand, it is necessary to consider that a resin having high spreadability is likely to be thin and easily cause bubble breakage because the partition walls of the cells are easily stretched during foaming. Therefore, it is not said that the higher the spreadability is, the better the idea that a specific value is preferable.

Such a balance between melt tension and spreadability is usually in a trade-off relationship, and if one is given priority, the other often deteriorates. The essence of the present invention that has successfully overcome this trade-off relationship and achieves both cell formation during foaming and surface formation during extrusion is the combined use of a specific long-chain branched polypropylene and a specific impact copolymer. . Long-chain branched polypropylene generally has high melt tension but poor spreadability. On the other hand, an impact copolymer having a propylene-ethylene copolymer having a high intrinsic viscosity is a blend of a propylene (co) polymer having a relatively low viscosity and a propylene-ethylene copolymer having a relatively high viscosity. Therefore, although the spreadability is generally high, the melt tension is not a sufficient level for foam molding. It is the essence of the present invention to use both of these in a complementary manner. In order to bring out the advantages of the two, the present inventors have to satisfy certain characteristics of each of the long-chain branched polypropylene and the impact copolymer. I found out that it was not. In particular, the viscosity of the long-chain branched polypropylene is lower than that conventionally considered, and the long-chain branched polypropylene is set in a region having a relatively low melt tension (of course, normal polypropylene or propylene-ethylene having a high intrinsic viscosity). On the contrary, it is important for the extrusion foam molding to set the viscosity of the propylene-ethylene copolymer of the impact copolymer to be higher than the melt tension of the impact copolymer having the copolymer.
It should be noted that the technical idea shown here and the specific embodiments described below are not described or suggested at all in the publicly known documents as mentioned above.

That is, according to the first invention of the present invention, the impact copolymer (Y) comprising polypropylene (X) 5 to 99 wt%, propylene (co) polymer (YH) and propylene-ethylene copolymer (YC). Polypropylene resin composition (Z) containing 1 to 95 wt% [However, the total of polypropylene (X) and impact copolymer (Y) is 100 wt%. ], And
The polypropylene (X) satisfies the following characteristics (Xi) to (X-iv),
The propylene (co) polymer (YH) satisfies the following characteristics (YH-i) to (YH-ii):
The propylene-ethylene copolymer (YC) satisfies the following characteristics (YC-i) to (YC-ii):
The impact copolymer (Y) satisfies the following characteristics (Yi), and the polypropylene resin composition (Z) satisfies the following characteristics (Zi) to (Z-ii): A polypropylene resin composition for extrusion foam molding is provided.
Characteristic (Xi): Long chain branching.
Characteristic (X-ii): Melt tension (MT) measured at 230 ° C. is 2 to 10 g.
Characteristic (X-iii): MFR exceeds 5 g / 10 min and is 20 g / 10 min or less.
Characteristic (X-iv): 25 degreeC xylene soluble component amount (CXS) is less than 5 wt% with respect to polypropylene (X) whole quantity.
Characteristic (YH-i): a propylene homopolymer or a copolymer of propylene (copolymer) with at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms. ) When the polymer (YH) is a copolymer, the total content of ethylene and α-olefin in (YH) exceeds 0 and is 3 wt% or less.
Characteristic (YH-ii): MFR is 1 to 100 g / 10 min.
Characteristic (YC-i): The ethylene content in the propylene-ethylene copolymer (YC) is 10 to 90 wt% with respect to the total amount of the propylene-ethylene copolymer (YC).
Characteristic (YC-ii): The intrinsic viscosity measured in 135 ° C. decalin is 5 to 20 dl / g.
Characteristic (Yi): The content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is 1 wt% or more and less than 50 wt% with respect to the total amount of the impact copolymer (Y).
Characteristic (Zi): MFR is 0.1 to 20 g / 10 min.
Characteristic (Z-ii): Melt tension (MT) measured at 230 ° C. is 1 to 7 g.

Moreover, according to 2nd invention of this invention, 0.1-1000 weight part of propylene (co) polymer (H) is contained with respect to 100 weight part of polypropylene resin compositions (Z) based on 1st invention. A polypropylene resin composition (Z ′) comprising:
The propylene (co) polymer (H) is a propylene homopolymer or a copolymer of propylene with at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms. When the propylene (co) polymer (H) is a copolymer, the total content of ethylene and α-olefin in the propylene (co) polymer (H) exceeds 0 and is 3 wt% or less. A polypropylene resin composition for extrusion foam molding is provided.

According to a third invention of the present invention, in the first or second invention, the polypropylene (X) further satisfies the following property (Xv): Things are provided.
Characteristic (Xv): The branching index g ^{′ at an} absolute molecular weight Mabs of 1 million is 0.3 or more and less than 1.0.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the polypropylene (X) further satisfies the following property (X-vi): A molding polypropylene resin composition is provided.
Characteristic (X-vi): strain hardening degree (λmax) in measurement of extensional viscosity is 5-12.
Furthermore, according to the fifth invention of the present invention, in any one of the first to fourth inventions, the impact copolymer (Y) further satisfies the following property (Y-ii): A polypropylene resin composition for foam molding is provided.
Characteristic (Y-ii): MFR is 0.1 to 20 g / 10 min.

  According to the sixth invention of the present invention, in any one of the first to fifth inventions, the blowing agent is added in an amount of 0.05 to 100 parts by weight of the total of the polypropylene (X) and the impact copolymer (Y). There is provided a polypropylene resin composition for extrusion foam molding characterized by containing ~ 6.0 parts by weight.

According to the seventh invention of the present invention, there is provided a polypropylene-based foam sheet produced by using the polypropylene resin composition for extrusion foam molding according to any one of the first to sixth inventions. .
According to an eighth aspect of the present invention, there is provided a polypropylene-based multilayer foamed sheet characterized in that a non-foamed layer is laminated on at least one surface of the polypropylene-based foamed sheet according to the seventh aspect. Is done.
Further, according to a ninth aspect of the present invention, in the eighth aspect, the non-foamed layer has an impact copolymer (Y ′) that satisfies the characteristics and requirements to be satisfied by the impact copolymer (Y) according to the first aspect. [However, the impact copolymer (Y ′) may be the same as or different from the impact copolymer (Y). A polypropylene-based multilayer foamed sheet characterized by comprising a polypropylene resin composition.

  According to a tenth aspect of the present invention, there is provided a heat produced by thermoforming the polypropylene foam sheet or the polypropylene multilayer foam sheet according to any of the seventh to ninth inventions. A molded body is provided.

The polypropylene resin composition for extrusion foam molding of the present invention has a very uniform cell formation during foam molding even under conditions of a high extrusion rate and a high molding speed, and has a high closed cell ratio, a dense and uniform size. A foam-molded article having open cells can be produced. In addition, it is possible to produce a foam sheet having a very high fluidity and spreadability and a beautiful appearance at a high extrusion rate. Moreover, while having such a high foaming characteristic, it has excellent draw-down resistance and good thermoformability.
The foamed molded body thus obtained has excellent appearance, thermoformability, impact resistance, lightness, rigidity, heat resistance, heat insulation, oil resistance, etc. It can be suitably used for vehicle interior materials such as food containers, automobile door trims, and automobile trunk mats, packaging, stationery, and building materials.

FIG. 1 is a diagram illustrating measurement results of a sag test in Example 1 as an evaluation of thermoformability and drawdown resistance of a foam sheet.

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention is not limited to the following unless it exceeds the gist. The description is not limited.

The polypropylene resin composition for extrusion foam molding of the present invention (hereinafter sometimes referred to as a resin composition) has polypropylene (X) of 5 to 99 wt% having specific physical properties, specific requirements and specific physical properties. It is characterized by containing 1 to 95 wt% of the impact copolymer (Y).
Below, the characteristics etc. which polypropylene (X) and impact copolymer (Y) should satisfy | fill are described in detail for every item.

I. Polypropylene (X)
The polypropylene (X) used in the present invention may be a propylene homopolymer or a propylene copolymer. In the case of a propylene copolymer, the comonomer is at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms, and the content of the comonomer in polypropylene (X) is 3 wt% or less. It is. The polypropylene (X) of the present invention is preferably a propylene homopolymer because of its high heat resistance and rigidity.

The polypropylene (X) in the present invention satisfies the following characteristics (Xi) to (X-iv).
Characteristic (Xi): Long chain branching.
Characteristic (X-ii): Melt tension (MT) measured at 230 ° C. is 2 to 10 g.
Characteristic (X-iii): MFR exceeds 5 g / 10 min and is 20 g / 10 min or less.
Characteristic (X-iv): 25 degreeC xylene soluble component amount (CXS) is less than 5 wt% with respect to polypropylene (X) whole quantity.

Among such polypropylenes (X), those satisfying the following characteristics (X-v) are more preferable, and those satisfying the following characteristics (X-vi) are most preferable.
Characteristic (Xv): The branching index g ^{′ at an} absolute molecular weight Mabs of 1 million is 0.3 or more and less than 1.0.
Characteristic (X-vi): strain hardening degree (λmax) in measurement of extensional viscosity is 5-12.
Hereinafter, the details will be described in order.

I-1. Characteristic (X-i): Long chain branching The polypropylene (X) according to the present invention must have long chain branching. Long-chain branching refers to a branched structure of a molecular chain consisting of several tens or more main chain carbon atoms and several hundred or more in molecular weight, and the number of carbons formed by copolymerization with an α-olefin such as 1-butene. A distinction is made from several short chain branches.
There are several methods for examining whether or not there is long-chain branching in polypropylene, but the one based on the rheological characteristics of the resin as shown in the characteristics (X-ii) (X-vi) can be easily used. As a more rigorous identification method, there are a method using the relationship between molecular weight and viscosity, a method using ¹³ C-NMR, etc., as shown in the feature (Xv). Regarding the latter, Patent Document 7 and Macromol. Chem. Phys. 2003, vol. Refer to 204 and 1738 for detailed explanation.

I-2. Characteristic (X-ii): Melt tension (MT)
The polypropylene (X) according to the present invention must have a melt tension (MT) of 2 to 10 g as shown in the above-mentioned property (X-ii). The melt tension (MT) in the present invention is a value measured under the following conditions.

[MT measurement conditions]
Measuring device: Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd.
Capillary: 2.0mm diameter, 40mm length
Cylinder diameter: 9.55mm
Cylinder extrusion speed: 20 mm / min Take-up speed: 4.0 m / min (however, if MT is too high and the resin breaks, the take-up speed is lowered and the maximum take-up speed is measured.)
Temperature: 230 ° C

Melt tension (MT) is recognized as an important factor for foam molding, and many patent documents specify MT.
For example, Patent Document 7 discloses a propylene polymer having high MT and swell and excellent moldability. Regarding MT, there is a description of a preferable range in paragraph [0078], and the higher the better, the most preferable being 15 g or more. Therefore, Patent Document 7 does not contain any description suggesting a specific MT value of the present invention, and the present invention that MT having a relatively low MT of 2 to 10 g is preferable as polypropylene having a long chain branch. The technical idea of the invention is fundamentally different.
Patent Documents 8 and 9 disclose an extrusion foam molding resin composition and a polypropylene foam sheet, respectively. Descriptions relating to MT are in paragraphs [0074] and [0076], respectively, but are the same as in Patent Document 7, and there is no description that suggests a specific MT value of the present invention.
Patent Document 10 discloses a polypropylene resin foam produced by extrusion foaming using a mixture of a high MT polypropylene having a long chain branch and a low MT polypropylene. In this case as well, there is a detailed description in paragraph [0014], but it is described that MT is preferably higher, and there is no description that suggests a specific MT value of the present invention.
Further, Patent Document 11 discloses a polypropylene resin extruded foam sheet in which a base resin is a mixture of a high MT polypropylene resin and a low MT polypropylene resin. Examples of high MT polypropylene resins are described in paragraph [0015], and have long chain branching or crosslinking, but as defined in claim 1 of the claims, MT is 10 cN or more. The higher one is preferable (1 g = 0.98 cN), and there is no description suggesting the specific MT value of the present invention.
In addition, Patent Document 12 includes a low MFR polypropylene, a specific prescribed propylene / ethylene block copolymer, a polypropylene containing an olefin polymer having a very high intrinsic viscosity, and hydrogenation of a styrene / conjugated diene block copolymer. A polypropylene resin composition comprising a thermoplastic resin such as a product is disclosed. Although a polypropylene containing an olefin polymer having a very high intrinsic viscosity corresponds to a high MT polypropylene, this Patent Document 12 does not include any description that suggests a long chain branched polypropylene having a specific MT value of the present invention. Absent. In addition, the polypropylene containing the olefin polymer having an extremely high intrinsic viscosity disclosed in Patent Document 12 is difficult to disperse the olefin polymer having an extremely high intrinsic viscosity, the bright spot is poor, and the appearance of the molded product tends to be deteriorated. It also includes such problems.
Furthermore, Patent Document 13 discloses a polypropylene-based expanded foam film obtained by stretching a propylene resin composition comprising a polypropylene having a long chain branch, a propylene-based polymer, and a foaming agent in at least one direction. Yes. Also in this case, as described in paragraph [0072], a higher MT is preferable, and there is no description suggesting a specific MT value of the present invention.

The polypropylene (X) according to the present invention must have an MT of 2 to 10 g. About the minimum of MT, it is preferable that MT is 3 g or more. As for the upper limit of MT, MT is preferably 9 g or less, more preferably MT is 8 g or less, and most preferably 7 g or less. If the MT value is too high, the spreadability at the time of extrusion molding deteriorates, the appearance of the sheet, film, molded product, etc. deteriorates, or the open cell ratio deteriorates due to bubble breakage due to poor spreading. It is not preferable. Conversely, if the value of MT is too low, it is preferable that the open cell ratio deteriorates, the cell diameter increases, or the cell size becomes non-uniform due to bubble breakage due to insufficient tension during foam cell formation. Absent.
Specific methods for controlling MT within the above range include a method for changing the number of long chain branches by adjusting the catalyst production method (particularly, the loading ratio of the complex), and within the range of characteristics (X-iii). There is a method for adjusting the MFR. Increasing the number of long chain branches or lowering MFR increases MT. On the other hand, in order to lower MT, it is only necessary to adjust in the reverse direction.

I-3. Characteristic (X-iii): MFR
The polypropylene (X) according to the present invention must have an MFR of more than 5 g / 10 minutes and not more than 20 g / 10 minutes as shown in the above property (X-iii).
MFR in the present invention is A method, condition M (230 ° C., 2.16 kg load) of JIS K7210: 1999 “Plastics—Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics”. It is a value measured according to.

MFR is the most basic factor in polypropylene molding. In the case of foam molding or extrusion molding, it is generally said that a relatively low value is preferred.
For example, in Patent Document 7, there is a description of a preferable range in paragraph [0037] of MFR, and it is described that a relatively low value is preferable in the case of extrusion foam molding, and the most preferable range is 1. It is described as 0 to 3.0 g / 10 min. Therefore, Patent Document 7 has no description suggesting a specific MFR value of the present invention, and for extrusion foam molding, a relatively high value exceeding 5 g / 10 minutes and preferably 20 g / 10 minutes or less is preferable. This is different from the present invention.
Moreover, in the said patent documents 8 and 9, although the description regarding MFR exists in a paragraph [0035] and [0037], respectively, it is described that a comparatively low value is preferable like the said patent document 7, and is the most preferable. The range is stated as 2-5 g / 10 min. Thus, there is no description in both patent documents that suggests a specific MFR value of the present invention.
In addition, in Patent Document 10, although there is no description about MFR in the detailed description, the values (MI) of the examples are 1.8 and 3.0 g / 10 minutes (paragraph [0030]). It is not within the specified range.
Moreover, in the said patent document 11, although there exists description about the MFR ratio of a high MT polypropylene resin and a low MT polypropylene resin, there is no detailed description regarding the value of MFR itself. The value of the MFR of the example is 3.2 g / 10 minutes (paragraph [0052]), and does not fall within the prescribed range of the present invention.
Moreover, in the said patent document 12, although the polypropylene containing the olefin polymer which has very high intrinsic viscosity corresponds to the polypropylene of high MT, the detailed description regarding the MFR exists in the paragraph [0047], and the most preferable range is It is described as 0.2 to 5.0 g / 10 min. There is no suggestion in this patent document regarding the long-chain branched polypropylene having the specific MFR value of the present invention.
Further, in the case of Patent Document 13, as described in paragraph [0034], the MFR is preferably low, and the most preferable range is described as 2 to 5 g / 10 min. There is no description suggesting a specific MFR value of the present invention.

The polypropylene (X) according to the present invention must have an MFR of more than 5 g / 10 minutes and not more than 20 g / 10 minutes. The lower limit of MFR is preferably 6 g / 10 minutes or more, more preferably 7 g / 10 minutes or more, and most preferably 8 g / 10 minutes or more. If the MFR is too low, the spreadability at the time of extrusion molding is deteriorated, the appearance of the sheet, film, molded product, etc. is deteriorated, or the open cell ratio is deteriorated due to bubble breakage due to poor extension, which is not preferable. . The upper limit of MFR is preferably 17 g / 10 min or less, more preferably 15 g / 10 min or less, still more preferably 13 g / 10 min or less, and most preferably 10 g / 10 min or less. If the MFR is too high, a portion that is excessively stretched during foam cell formation is likely to occur, and the open cell ratio may deteriorate due to bubble breakage, the cell diameter may increase, or the cell size may become uneven. It is not preferable.
As a specific method for adjusting the MFR to the above range, a method of changing the amount of hydrogen added during polymerization can be mentioned. Since hydrogen acts as a chain transfer agent in the polymerization of propylene, if the amount of hydrogen added is increased, the MFR increases. Conversely, if the amount added is decreased, the MFR can be decreased. The value of MFR relative to the hydrogen concentration inside the polymerization tank varies depending on the catalyst used and other polymerization conditions, but the relationship between the hydrogen concentration and MFR is determined in advance according to the catalyst type and other polymerization conditions, and the desired MFR value is determined. It is very easy for those skilled in the art to adjust the hydrogen concentration so as to obtain a value.

I-4. Characteristic (X-iv): 25 ° C. xylene-soluble component amount (CXS)
The polypropylene (X) according to the present invention must have a 25 ° C. xylene-soluble component amount (CXS) of less than 5 wt% as shown in the above property (X-iv) (however, the total amount of polypropylene (X) is 100 wt%). CXS in the present invention is a value measured by the following procedure.

[CXS measurement procedure]
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml BHT) at 130 ° C. to make a solution, and then left at 25 ° C. for 12 hours. Thereafter, the precipitated polymer is separated by filtration, p-xylene is evaporated from the filtrate, and further dried under reduced pressure at 100 ° C. for 12 hours to recover a 25 ° C. xylene-soluble component. The ratio [wt%] of the weight of the recovered component to the charged sample weight is defined as CXS.

CXS is a general index representing a low crystalline polymer component. If this value is high, the content of the low crystalline component in polypropylene (X) is high, which may cause problems during molding or the product itself. is there. For example, there is a tendency to cause a problem of eye smoke or smoke during extrusion foam molding, or a problem that the surface of a sheet, film, or product becomes sticky. The polypropylene (X) according to the present invention must have a CXS of less than 5 wt%. CXS is preferably less than 3 wt%, more preferably less than 1 wt%, and most preferably less than 0.5 wt%. Although there is no restriction | limiting in particular about the lower limit of CXS, If it is 0.01 wt% or more, Preferably it is 0.05 wt% or more, the effect of an additive will become easy to express.
As a specific method for adjusting CXS to the above range, a catalyst can be selected. The most important factor for determining CXS of polypropylene having a long chain branch is a catalyst, and a catalyst satisfying CXS may be selected from known catalysts. Specific examples of the catalyst will be described later.

I-5. Characteristic (Xv): Branch index g ^′
The polypropylene (X) according to the present invention must satisfy the characteristics (Xi) to (X-iv), but preferably satisfies the following characteristics (Xv).
Characteristic (Xv): The branching index g ^{′ at an} absolute molecular weight Mabs of 1 million is 0.3 or more and less than 1.0.

The branching index g ^′ is known as a more direct indicator for long chain branching. There is a detailed description in “Developments in Polymer Characterization-4” (JV Dawkins ed. Applied Science Publishers, 1983). The definition of the branching index g ^′ is as follows.
Branch index g ^′ = [η] br / [η] lin
[Η] br: Intrinsic viscosity of the polymer (br) having a long-chain branched structure [η] lin: Intrinsic viscosity of a linear polymer having the same molecular weight as the polymer (br)

As is clear from the above definition, when a long chain branching structure exists, the branching index g ^′ takes a value smaller than 1, and the value of the branching index g ^′ decreases as the long chain branching structure increases. Since polypropylene generally has a molecular weight distribution, if a long-chain branched structure exists in a component having a considerably large molecular weight, it can efficiently promote entanglement and contribute to enhancing foaming characteristics. Therefore, among the polypropylenes (X) according to the present invention, those in which the value of the branching index g ^′ when the absolute molecular weight Mabs is 1 million are in a specific range are particularly preferable.
In order to know the value of the branching index g ^′ when the absolute molecular weight Mabs is 1 million, the value of the branching index g ^′ must be obtained as a function of the absolute molecular weight Mabs. In this regard, the following measurement method, analysis method, and calculation method are used in the present invention.

[Measuring method]
GPC: Alliance GPCV2000 (Waters)
Detector: Described in the order of connection Multi-angle laser light scattering detector (MALLS): DAWN-E (Wyatt Technology)
Differential refractometer (RI): attached to GPC Viscometer (Viscometer): attached to GPC Mobile phase solvent: 1,2,4-trichlorobenzene (Irganox 1076 added at a concentration of 0.5 mg / mL)
Mobile phase flow rate: 1 mL / min Column: Tosoh Corporation GMHHR-H (S) Two HT connections Sample injection part temperature: 140 ° C.
Column temperature: 140 ° C
Detector temperature: 140 ° C for all
Sample concentration: 1 mg / mL
Injection volume (sample loop volume): 0.2175 mL

[analysis method]
When calculating the absolute molecular weight (Mabs) obtained from the multi-angle laser light scattering detector (MALLS), the root mean square radius of inertia (Rg), and the intrinsic viscosity ([η]) obtained from the Viscometer, data processing attached to MALLS Calculation is performed using the software ASTRA (version 4.73.04) with reference to the following document.
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 method of branching index g ′]
The branching index g ′ is a ratio of the intrinsic viscosity ([η] br) obtained by measuring a sample with the above Viscometer and the intrinsic viscosity ([η] lin) obtained separately by measuring a linear polymer ([[ η] br / [η] lin).
Here, as a linear polymer for obtaining [η] lin, a commercially available homopolypropylene (Novatec PP (registered trademark) grade name: FY6 manufactured by Nippon Polypro Co., Ltd.) is used. It is known as a Mark-Houwink-Sakurada formula that the logarithm of [η] lin of a linear polymer has a linear relationship with the logarithm of molecular weight, and [η] lin is The values are obtained by extrapolation as appropriate.

The polypropylene (X) according to the present invention preferably has a branching index g ^′ of 0.3 or more and less than 1.0 when the absolute molecular weight Mabs is 1,000,000. More preferably, they are 0.55 or more and 0.98 or less, More preferably, they are 0.75 or more and 0.96 or less, Most preferably, they are 0.78 or more and 0.95 or less.
When the branching index g ′ is in the above range, the degree of decrease in melt tension when kneading is repeated is small, and therefore the decrease in physical properties and moldability during material recycling in the production process is preferably small.
As a specific method for adjusting the branching index g ′ within the above range, a catalyst can be selected. The most important factor for determining the branching index g ′ of polypropylene having a long chain branch is a catalyst, and a catalyst satisfying the branching index g ′ may be selected from known catalysts. Specific examples of the catalyst will be described later.

I-6. Characteristic (X-vi): strain hardening degree (λmax) in measurement of extensional viscosity
The polypropylene (X) according to the present invention must satisfy the above-mentioned characteristics (X-i) to (X-iv), and preferably satisfies the characteristics (X-v). It is preferable to satisfy the characteristic (X-vi).
Characteristic (X-vi): strain hardening degree (λmax) in measurement of extensional viscosity is 5-12.

In the calculation of λmax in the present invention, the value of extensional viscosity measured under the following conditions is used.
Apparatus: Ales manufactured by Rheometrics
Jig: EXTENSIONAL VISUALITY FIXTURE, manufactured by TA Instruments
Measurement temperature: 180 ° C
Strain rate: 0.1 / sec
Test piece preparation method: Press molding Test piece shape: Sheet of 18 mm x 10 mm, thickness 0.7 mm

Next, a method for calculating λmax from the obtained value of extensional viscosity will be described.
First, the time t (second) is plotted on the horizontal axis and the elongational viscosity η _E (Pa · second) is plotted on the logarithmic graph on the vertical axis, and the viscosity immediately before strain hardening is approximated by a straight line on the logarithmic graph. Specifically, first, the slope at each time when the extensional viscosity is plotted against time is obtained. In this case, considering the fact that the measurement data of the extensional viscosity is discrete, the slope of the adjacent data is obtained. Is used, and a moving average of several surrounding points is used.
The elongational viscosity is a simple increasing function in the low strain region, gradually approaches a constant value, and if there is no strain hardening, it agrees with the Truton viscosity after a sufficient amount of time. From about 1 strain amount (= strain rate × time), the extensional viscosity starts to increase with time. That is, the slope tends to decrease with time in the low strain region, but tends to increase from about 1 strain, and there is an inflection point on the curve when the extensional viscosity is plotted against time. . Therefore, a point where the slope of each time obtained above takes the minimum value in the range of the distortion amount of about 0.1 to 2.5 is obtained, and a tangent line is drawn at the point, and the straight line has a distortion amount of 4.0. Extrapolate until The maximum value (ηmax) of the extensional viscosity η _E until the strain amount becomes 4.0 is obtained, and the viscosity on the approximate straight line up to that time is η lin. ηmax / ηlin is defined as λmax (0.1).

The degree of strain hardening (λmax) is also recognized as an important factor for foam molding, and many patent literatures specify the degree of strain hardening.
For example, in Patent Document 7, regarding the degree of strain hardening (λmax), there is a description of a preferable range in paragraph [0066] in addition to claim 1 of the scope of claims. Is referred to as 15.0 or higher. Therefore, Patent Document 7 has no description suggesting a specific strain hardening degree (λmax) value of the present invention, and a relatively low 5.0 to 12.0 is preferable as a polypropylene having a long chain branch. The technical idea of the invention is fundamentally different from the present invention.
Further, in Patent Documents 8 and 9, the descriptions on the strain hardening degree (λmax) are in paragraphs [0061] and [0063], respectively, but are the same as those in Patent Document 7, and the specific strains of the present invention are described. There is no description suggesting the value of the degree of cure (λmax).
Moreover, the said patent document 12 has no description which suggests regarding the long-chain branched polypropylene which has the value of specific strain hardening degree ((lambda) max) of this invention.
Further, in the case of Patent Document 13, as described in the paragraph [0059], it is preferable that the degree of strain hardening (λmax) is high, and the description suggesting the value of the specific degree of strain hardening (λmax) of the present invention is as follows. There is no.
In Patent Documents 10 and 11, there is no description of the strain hardening degree (λmax).

The polypropylene (X) according to the present invention preferably has a strain hardening degree (λmax) of 5 to 12. More preferably, strain hardening degree ((lambda) max) is 6-11, More preferably, it is 7-10. Among the polypropylenes (X) according to the present invention, those having a strain hardening degree (λmax) in this range are more preferable because the balance between spreadability and cell formation during foaming is particularly good.
Specific methods for controlling the strain hardening degree (λmax) within the above range include a method of changing the number of long-chain branches by adjusting the catalyst production method (particularly the loading ratio of the complex), and characteristics (X-iii). There is a method of adjusting the MFR within the range of When the number of long chain branches is increased or the MFR is lowered, the degree of strain hardening (λmax) increases. In order to lower the strain hardening degree (λmax), it may be adjusted in the opposite direction.

I-7. Other properties (X-vii): mm fraction The properties of the polypropylene (X) according to the present invention are as described above, but in addition, when a material satisfying the following properties (X-vii) is used, Even more preferred.
Characteristic (X-vii): The isotactic triad fraction (mm fraction) determined by ¹³ C-NMR is 95% or more.

Here, the mm fraction indicates the abundance of two consecutive methyl groups in which the steric relationship between adjacent methyl groups is meso in the three chain of propylene units. The description in paragraphs [0053] to [0065] shall be followed. The measurement conditions for ¹³ C-NMR also follow JP 2009-275207 A.
The mm fraction is an index of stereoregularity, and a higher value means that propylene units are regularly arranged in the polymer chain, and the degree of crystallinity tends to increase. Accordingly, the higher the mm fraction, the higher the heat resistance and rigidity, so that it is preferable. In the present invention, the mm fraction is preferably 95% or more, more preferably 96% or more, and still more preferably 97% or more.
As a specific method for adjusting the mm fraction to the above range, a catalyst can be selected. The most important factor for determining the mm fraction of polypropylene having a long chain branch is a catalyst, and a catalyst satisfying the mm fraction may be selected from known catalysts. Specific examples of the catalyst will be described later.

II. Production method of polypropylene (X) The production method of polypropylene (X) in the present invention is not particularly limited as long as the above properties (Xi) to (X-iv) are satisfied. Among various methods, a macromer copolymerization method using a combination of metallocene catalysts is preferably used. For example, the method disclosed in JP-A-2009-57542 can be exemplified. This technique uses a catalyst having a specific structure having a macromer generation ability and a specific structure having a high molecular weight and a macromer copolymerization ability to produce a polypropylene having a long chain branched structure. It is a manufacturing method.
Hereinafter, this method is selected as a specific example of the method for producing polypropylene (X) and will be described in detail.

II-1. Catalyst It is preferable to use a catalyst comprising the following catalyst components (A), (B) and (C).
Catalyst component (A): at least one component from component [A-1] which is a compound represented by the following general formula (a1), and component [A-2] which is a compound represented by the following general formula (a2) 2 or more transition metal compounds of Group 4 of the periodic table selected from at least one.
Component [A-1]: Compound represented by general formula (a1) Component [A-2]: Compound represented by general formula (a2) Catalyst component (B): Ion exchange layered silicate catalyst component (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 General Formula (a1), each of R ¹¹ and R ¹² independently represents a heterocyclic group containing nitrogen, oxygen or sulfur having 4 to 16 carbon atoms. Each of R ¹³ and R ¹⁴ independently represents an aryl group having 6 to 16 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected from these, Alternatively, it represents a heterocyclic group containing nitrogen, oxygen or sulfur having 6 to 16 carbon atoms. X ¹¹ and Y ¹¹ each independently represent 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, oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, amino group, nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkylamide group having 1 to 20 carbon atoms, trifluoromethane A sulfonic acid group or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms is represented. Q ¹¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or a germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms. ]

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

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

X ¹¹ and Y ¹¹ are auxiliary ligands, and react with the catalyst component (B) to generate 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 are independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. A C1-C20 silicon-containing hydrocarbon group, a C1-C20 halogenated hydrocarbon group, a C1-C20 oxygen-containing hydrocarbon group, an amino group, or a C1-C20 nitrogen-containing hydrocarbon Group, an alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms.

Q ¹¹ is a binding group that bridges two conjugated five-membered rings, and may have a divalent hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms. A silylene group or a germylene group is shown. When two hydrocarbon groups are present on the silylene group or the germylene group, they may be bonded to each other to form a ring structure.
Specific examples of Q ¹¹ include alkylene groups such as methylene, methylmethylene, dimethylmethylene and 1,2-ethylene; arylalkylene groups such as diphenylmethylene; silylene groups; methylsilylene, dimethylsilylene, diethylsilylene, di ( n-propyl) silylene, di (i-propyl) silylene, alkylsilylene groups such as di (cyclohexyl) silylene, (alkyl) (aryl) silylene groups such as methyl (phenyl) silylene; arylsilylene groups such as diphenylsilylene; tetra An alkyl oligosilylene group such as methyldisilylene; a germylene group; an alkylgermylene group in which the silicon of the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl) (aryl) germylene Group; arylgermylene group And so on. In these, the silylene group which has a C1-C20 hydrocarbon group, or the germylene group which has a C1-C20 hydrocarbon group is preferable, and an alkylsilylene group and an alkylgermylene group are more preferable.

Of the compounds represented by the general formula (a1), preferred 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, dic B [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, dichloro [1,1′-dimethylsilylenebis {2- (2-benzofuryl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) Nyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) -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, di Loro [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′-dimethyl Silylenebis {2- (2-furyl) -4- (2-phenanthryl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-furyl) -4- ( -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-tert-butyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, Chloro [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.

Of these, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylene are more preferable. Bis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) -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-tert-butylphenyl) -indenyl}] hafnium.
More preferably, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis { 2- (5-Methyl-2-furyl) -4- (4-i-propylphenyl) -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 General Formula (a2), each of R ²¹ and R ²² independently represents a hydrocarbon group having 1 to 6 carbon atoms. R ²³ and R ²⁴ each independently represent an aryl group having 6 to 16 carbon atoms, which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected from these. Represent. X ²¹ and Y ²¹ each independently represent 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, oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, amino group, nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkylamide group having 1 to 20 carbon atoms, trifluoromethane A sulfonic acid group or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms is represented. Q ²¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or a germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms. M ²¹ represents 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 preferably methyl. , Ethyl, n-propyl. R ²¹ and R ²² are preferably the same as each other.

R ²³ and R ²⁴ are each independently an aryl having 6 to 16 carbon atoms, preferably 6 to 12 carbon atoms, which may contain halogen, silicon, or a plurality of hetero elements selected from these. It is a group. Preferred examples include 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. R ²³ and R ²⁴ are preferably the same as each other.

X ²¹ and Y ²¹ are auxiliary ligands, and react with 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 to the type of ligand, and are independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. A C1-C20 silicon-containing hydrocarbon group, a C1-C20 halogenated hydrocarbon group, a C1-C20 oxygen-containing hydrocarbon group, an amino group, or a C1-C20 nitrogen-containing hydrocarbon Group, an alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms.

Q ²¹ is a binding group that bridges two conjugated five-membered rings, and may have a divalent hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms. A silylene group or a germylene group is shown. When two hydrocarbon groups are present on the silylene group or the germylene group, they may be bonded to each other to form a ring structure. A substituted silylene group or a substituted germylene group is preferred.

  The substituent bonded to silicon and 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, methylphenylgermylene and the like.

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

Among the compounds represented by the general formula (a2), specific examples of preferable compounds are given below.
Although compounds having a central metal of hafnium have been described, compounds replacing zirconium are also treated as non-limiting examples.

  Dichloro {1,1′-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazurenyl)} hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4 -Hydroazulenyl}] 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-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- ( -Methyl-4-t-butylphenyl) -4-hydroazurenyl}] 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-hydroazurenyl}] hafnium, dichloro [ 1,1′-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl)- -Hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-Methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (9-phenanthryl) -4-hydroazurenyl] }] Hafnium, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-n-propyl -4- (3-Chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] huff Nitrogen, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-tert-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-hydroazurenyl}] Funium, 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-hydroazurenyl}] hafnium, and the like.

  Of these, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium, 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-hydroazurenyl}] hafnium, dichloro [1,1′-dimethyl. Silylenebis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazuleni }] Hafnium, dichloro [1,1 ′-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium .

  More 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-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4 -Hydroazulenyl}] 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) is preferably an ion-exchange layered silicate.
(I) Types of ion-exchanged layered silicates Ion-exchanged layered silicates (hereinafter sometimes simply referred to as silicates) are surfaces in which ionic bonds and the like are stacked in parallel with each other with a binding force. This refers to a silicate compound having a crystal structure and containing exchangeable ions. Most silicates are naturally produced mainly as the main component of clay minerals, and therefore often contain impurities (quartz, cristobalite, etc.) other than ion-exchanged layered silicates. But you can. Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, it may be preferable to pure silicate, and such a complex is also included in the catalyst component (B).
The silicate used in the present invention is not limited to a natural product, and may be an artificial synthetic product or may contain them.

Specific examples of the silicate include the following layered silicates described in Haruo Shiramizu “Clay Mineralogy” Asakura Shoten (1995).
That is, montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stemite and other smectites, vermiculite and other vermiculites, mica, illite, sericite and sea chlorite and other mica, attapulgite, sepiolite and palygorskite , Bentonite, pyrophyllite, talc, chlorite group, etc.
The silicate is preferably a silicate in which the main component silicate has a 2: 1 type structure, more preferably a smectite group, and particularly preferably montmorillonite. The type of 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 easy and inexpensive to obtain as an industrial raw material.

(Ii) Chemical treatment of ion-exchange layered silicate The ion-exchange 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 preferable to perform a chemical treatment. . Here, the chemical treatment of the ion-exchange layered silicate may be any of a surface treatment for removing impurities adhering to the surface and a treatment that affects the structure of the clay. Treatment, alkali treatment, salt treatment, organic matter treatment and the like.

<Acid treatment>:
In addition to removing impurities on the surface, the acid treatment can elute part or all of cations such as Al, Fe, Mg, etc. 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 salts (described in the next section) and acid may be used for the treatment. The treatment conditions with salts and acids are not particularly limited. Usually, the salt and acid concentrations are 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 carry out the process under the condition of selecting and eluting at least a part of the substance constituting at least one compound selected from the group consisting of ion-exchangeable layered silicates. In addition, salts and acids are generally used in an aqueous solution.
In addition, you may use what combined the following acids and salts as a processing agent. Moreover, the combination of these acids and salts may be sufficient.

<Salt treatment>:
Ion-exchange 40% or more, preferably 60% or more of the exchangeable metal cations contained in the ion-exchange layered silicate before being treated with salts with cations dissociated from the salts shown below. Is preferred.
Salts used in such salt treatment for ion exchange are composed of at least one cation selected from the group consisting of an organic cation, an inorganic cation and a metal ion, and an organic anion and an inorganic anion. Examples thereof include salts composed of at least one anion selected from the group. For example, at least selected from the group consisting of a cation containing at least one atom selected from the group consisting of Group 1 to 14 atoms of the periodic table, a halogen anion, and an anion derived from an inorganic acid and an organic acid A preferred example is a compound composed of a kind of anion. Here, the anion derived from an acid is an anion in which at least one hydrogen cation is eliminated from the acid. For example, in the case of a monovalent inorganic acid such as HNO ₃ , the anion derived from the acid is NO ₃ ^— , and in the case of a trivalent inorganic acid such as H ₃ PO ₄ , the acid There are three types of anions derived from H ₂ PO ₄ ⁻ , HPO ₄ ²⁻ and PO ₄ ³⁻ . The same applies to anions derived from organic acids. More preferred is a compound in which the cation is a metal ion and the anion is an anion derived from an inorganic acid or a halogen anion.

Specific examples of such salts are LiF, LiCl, LiBr, LiI, Li ₂ SO ₄ , Li (CH ₃ COO), Li ₂ CO ₃ , LiHCO ₂ , Li ₂ C ₂ O ₄ , LiClO ₄ , Li _3. PO ₄ , CaCl ₂ , CaSO ₄ , CaC ₂ O ₄ , Ca (NO ₃ ) ₂ , MgCl ₂ , MgBr ₂ , MgSO ₄ , Mg ₃ (PO ₄ ) ₂ , Mg (ClO ₄ ) ₂ , MgC ₂ O ₄ , _{mg (NO 3) 2, mg} (CH 3 COO) 2 and the like.

_{Further, Ti (CH 3 COO) 4} , Ti (CO 3) 2, Ti (NO 3) 4, Ti (SO 4) 2, TiF 4, TiCl 4, Zr (CH 3 COO) 4, Zr (CO 3) ₂ , Zr (NO ₃ ) ₄ , Zr (SO ₄ ) ₂ , ZrF ₄ , ZrCl ₄ , Hf (CH ₃ COO) ₄ , Hf (CO ₃ ) ₂ , Hf (NO ₃ ) ₄ , Hf (SO ₄ ) _{2 , HfF 4, HfCl 4, V} (CH 3 COCHCOCH 3) 3, VOCl 3, VCl 3, VCl 4, VBr 3 , etc. may be mentioned.

Also, Cr (CH ₃ COCHCOCH ₃ ) ₃ , Cr (NO ₃ ) ₃ , Cr (ClO ₄ ) ₃ , CrPO ₄ , Cr ₂ (SO ₄ ) ₃ , CrF ₃ , CrCl ₃ , CrBr ₃ , CrI ₃ , Mn ( CH ₃ COO) ₂ , Mn (CH ₃ COCHCOCH ₃ ) ₂ , MnCO ₃ , Mn (NO ₃ ) ₂ , MnO, Mn (ClO ₄ ) ₂ , MnF ₂ , MnCl ₂ , Fe (CH ₃ COO) 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 , FeF ₃ , FeCl _{3 and the} like.

In addition, Co (CH ₃ COO) 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 (CH ₃ COO) 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.

<Alkali treatment>:
In addition to acid and salt treatment, the following alkali treatment or organic matter treatment 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 , Ba (OH) _{2 and the} like.

<Organic treatment>:
Examples of the organic treatment agent used for organic treatment include trimethylammonium, triethylammonium, N, N-dimethylanilinium, triphenylphosphonium, and the like.
Examples of the anion constituting the organic treatment agent include hexafluorophosphate, tetrafluoroborate, and tetraphenylborate other than the anion exemplified as the anion constituting the salt treatment agent. It is not limited to these.

Moreover, these processing agents may be used independently and may be used in combination of 2 or more types. These combinations may be used in combination for the treatment agent added at the start of the treatment, or may be used in combination for the treatment agent added during the treatment. The chemical treatment can be performed a plurality of times using the same or different treatment agents.
These ion-exchange layered silicates usually contain adsorbed water and interlayer water. These adsorbed water and interlayer water are preferably removed and used as the catalyst component (B).

  The heat treatment method of the ion-exchange layered silicate adsorbed water and interlayer water is not particularly limited, but it is necessary to select conditions so that interlayer water does not remain and structural destruction does not occur. The heating time is 0.5 hour or longer, preferably 1 hour or longer. At that time, the water content of the catalyst component (B) after the removal is 3% by weight or less when the water content when dehydrating for 2 hours under the conditions of a temperature of 200 ° C. and a pressure of 1 mmHg is 0% by weight, It is preferably 1% by weight or less.

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

  The ion-exchange layered silicate can be treated with a catalyst component (C) of an organoaluminum compound, which will be described later, before formation of a catalyst or use as a catalyst, which is preferable. Although there is no restriction | limiting in the usage-amount of the catalyst component (C) with respect to 1g of ion-exchange layered silicate, Usually, 20 mmol or less, Preferably it is 0.5 mmol or more and 10 mmol or less. There is no limitation on the treatment temperature and time, the treatment temperature is usually 0 ° C. or more and 70 ° C. or less, and the treatment time is 10 minutes or more and 3 hours or less. It is also possible and preferable to wash after the treatment. As the solvent, the same hydrocarbon solvent as that used in the prepolymerization or slurry polymerization described later is used.

The catalyst component (B) is preferably spherical particles having an average particle size of 5 μm or more. If the particle shape is spherical, 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.
Examples of the granulation method used here include agitation granulation method and spray granulation method, but commercially available products can also be used.
Moreover, you may use organic substance, an inorganic solvent, inorganic salt, and various binders in the case of granulation.
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 process. In the case of such particle strength, the effect of improving the particle properties is effectively exhibited especially when prepolymerization is performed.

(3) Catalyst component (C)
The catalyst component (C) is an organoaluminum compound. Organic aluminum compounds used as the catalyst component (C) has the general ^{_{formula: (AlR 31 q Z 3-}} q) a compound represented by _p is suitable. The compounds represented by this formula can be used alone, in combination of plural 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, respectively. R ³¹ is preferably an alkyl group, and Z is a chlorine atom when it is a halogen atom, a C 1-8 alkoxy group when it is an alkoxy group, and a C 1 atom when it is an amino group. Eight amino groups are preferred.

Specific examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, trinormalpropylaluminum, trinormalbutylaluminum, triisobutylaluminum, trinormalhexylaluminum, trinormaloctylaluminum, trinormaldecylaluminum, diethylaluminum chloride, diethylaluminum. Examples thereof include sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, and diisobutylaluminum chloride.
Of these, trialkylaluminum or alkylaluminum hydride having p = 1 and q = 3 is preferable. More preferably, R ³¹ is trialkylaluminum having 1 to 8 carbon atoms.

(4) Catalyst formation / preliminary polymerization In the catalyst, the catalyst components (A) to (C) are brought into contact with each other in the (preliminary) polymerization tank simultaneously or continuously, or once or multiple times. Can be formed.
The contact of each component is usually carried out in an aliphatic hydrocarbon or aromatic hydrocarbon solvent. Although a contact temperature is not specifically limited, It is preferable to carry out between -20 degreeC and 150 degreeC. As the contact order, any desired combination can be used, but particularly preferable ones for each component are as follows.
Before contacting the catalyst component (A) with the catalyst component (B), the catalyst component (A), the catalyst component (B), or both the catalyst component (A) and the catalyst component (B) C), or contacting the catalyst component (C) with the catalyst component (A) and the catalyst component (B), or contacting the catalyst component (A) and the catalyst component (B). Although it is possible to contact the catalyst component (C) after contacting, preferably, the catalyst component (C) is brought into contact with any one of the catalyst component (C) before contacting the catalyst component (A) and the catalyst component (B). Is the method.
Moreover, after contacting each component, it is possible to wash with an aliphatic hydrocarbon or an aromatic hydrocarbon solvent.

The usage-amount of catalyst component (A), (B) and (C) is arbitrary. For example, the amount of the catalyst component (A) used relative to the catalyst component (B) is preferably in the range of 0.1 μmol to 1,000 μmol, particularly preferably 0.5 μmol to 500 μmol, relative 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 molar ratio of the transition metal. preferable.

Here, the functions of component [A-1] (compound represented by general formula (a1)) and component [A-2] (compound represented by general formula (a2)) in the present catalyst system will be described. deep.
In the present catalyst system, a macromer is formed by polymerization of a monomer, and a polypropylene having a long chain branch can be produced by copolymerization of the macromer and the monomer. Component [A-1] is a catalyst component that generates a so-called macromer having a relatively small molecular weight and having a vinyl group at the terminal, and component [A-2] is a chain having a relatively large molecular weight. In addition to the polypropylene chain, it is a catalyst component for copolymerizing a macromer produced from [A-1] with propylene to produce a high molecular weight polypropylene chain having a long chain branch.
Therefore, the number of long-chain branches in the polypropylene can be controlled by changing the usage ratio of the component [A-1] and the component [A-2]. The higher the ratio of component [A-1] used, the greater the amount of macromer produced and the longer chain branching in the polypropylene. If it does so, MT of polypropylene (X) will become high, branch index g ^' will become small, and (lambda) max will become high. If the usage ratio of component [A-2] is increased, the component changes in the opposite direction. How much long chain branching is actually generated varies depending on the component [A-1] and component [A-2] to be used, but the actual usage ratio of component [A-1] and component [A-2] is changed. It is easy for those skilled in the art to grasp the amount of long-chain branching produced and adjust it to the desired value. It is obvious that MT, branching index g ^′ , and λmax can be controlled if the amount of long chain branching can be controlled.
In addition, the length of the long chain branch can be changed by adjusting the molecular weight of the macromer by selecting [A-1].
Further, the CXS and mm fraction of the polypropylene (X) can be adjusted to the desired values of the characteristics (X-iv) and (X-vii) by appropriately adjusting the conditions and compounds within the above-mentioned preferred examples. It is easy to adjust.

  As described above, the use ratio of the component [A-1] and the component [A-2] may be appropriately adjusted in accordance with the properties of the polypropylene (X), but in general, the molar ratio of the transition metal, The ratio of [A-1] to the sum of component [A-1] and component [A-2] is preferably 0.30 or more and 0.99 or less.

  The catalyst exemplified above may be preliminarily polymerized by contacting with a small amount of olefin before the main polymerization. By performing pre-polymerization, rapid growth of polymer particles can be prevented, and polypropylene particles having a good shape can be formed.

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 and the like can be exemplified. The olefin feed method may be any method such as a feed method for maintaining the olefin at a constant speed 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 prepolymerization is preferably 0.01 to 100, more preferably 0.1 to 50 with respect to the catalyst component (B). Moreover, a catalyst component (C) can also be added or added at the time of prepolymerization. It is also possible to wash after the prepolymerization.

  In addition, a method of coexisting a polymer such as polyethylene or polypropylene, or a solid of an inorganic oxide such as silica or titania, at the time of contacting or after contacting each of the above components is also possible.

II-2. Polymerization Method (1) Use of Catalyst / Propylene Polymerization As for the polymerization mode, if the olefin polymerization catalyst including the catalyst component (A), the catalyst component (B) and the catalyst component (C) and the monomer are in efficient contact, Any style can be adopted.
Specifically, a slurry polymerization method using an inert solvent, a so-called bulk polymerization method, a solution polymerization method using substantially no inert solvent as a solvent, or a gas without using a liquid solvent. For example, a gas phase polymerization method for maintaining the shape can be employed. Moreover, the method of performing continuous polymerization and batch type polymerization is also applied. In addition to single-stage polymerization, it is possible to carry out multistage 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, and 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 a bulk polymerization method is used, it 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.
Furthermore, when using a gas phase polymerization method, it 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 a bulk polymerization method is used, 1.5 MPa or more is preferable, and 2.0 MPa or more is more preferable. The upper limit is preferably 4.0 MPa or less, more preferably 3.5 MPa or less.

Furthermore, when using vapor phase polymerization, 1.5 MPa or more is preferable, and 1.7 MPa or more is more preferable. Further, the upper limit is preferably 2.5 MPa or less, and more preferably 2.3 MPa or less.
Furthermore, as a molecular weight regulator, hydrogen can be used in a molar ratio of 1.0 × 10 ⁻⁶ or more and 1.0 × 10 ⁻² or less with respect to propylene.

  The polypropylene (X) according to the present invention is preferably produced by polymerizing propylene in the presence of an olefin polymerization catalyst or by copolymerizing propylene and a comonomer. Examples of the comonomer include at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms.

III. Impact copolymer (Y)
The impact copolymer (Y) according to the present invention includes a propylene (co) polymer (YH) satisfying the following characteristics (YH-i) to (YH-ii), and characteristics (YC-i) to (YC-ii). A propylene-ethylene copolymer (YC) satisfying the above-mentioned conditions and further satisfying the characteristics (Y-i).
Characteristic (YH-i): a propylene homopolymer or a copolymer of propylene (copolymer) with at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms. ) When the polymer (YH) is a copolymer, the total content of ethylene and α-olefin in (YH) exceeds 0 and is 3 wt% or less.
Characteristic (YH-ii): MFR is 1 to 100 g / 10 min.
Characteristic (YC-i): The ethylene content in the propylene-ethylene copolymer (YC) is 10 to 90 wt% with respect to the total amount of the propylene-ethylene copolymer (YC).
Characteristic (YC-ii): The intrinsic viscosity measured in 135 ° C. decalin is 5 to 20 dl / g.
Characteristic (Yi): The content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is 1 wt% or more and less than 50 wt% with respect to the total amount of the impact copolymer (Y).

The impact copolymer is usually a reactor blend of a crystalline propylene (co) polymer and a propylene-ethylene copolymer, and was formerly called a propylene-ethylene block copolymer.
The impact copolymer (Y) according to the present invention includes propylene (co) polymer (YH) satisfying characteristics (YH-i) to (YH-ii) and propylene satisfying characteristics (YC-i) to (YC-ii). -Reactor blend with ethylene copolymer (YC).
Details will be described in the order of propylene (co) polymer (YH), propylene-ethylene copolymer (YC), and impact copolymer (Y).

III-1. Propylene (co) polymer (YH)
The propylene (co) polymer (YH), which is a constituent component of the impact copolymer (Y) according to the present invention, is a main component constituting the crystal part of the impact copolymer (Y). The point is an important control point.

III-1-1. Characteristics (YH-i)
The propylene (co) polymer (YH) which is a constituent component of the impact copolymer (Y) according to the present invention is at least one selected from the group consisting of propylene homopolymers or ethylene and α-olefins having 4 to 10 carbon atoms. It is a copolymer of a seed olefin and propylene.
When the propylene (co) polymer (YH) is a copolymer, the content of at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms in (YH) is 0. And 3 wt% or less. When the content of at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms exceeds 3 wt%, the heat resistance of the final product is deteriorated, which is not preferable.
Specific examples of the α-olefin having 4 to 10 carbon atoms include 1-butene, 1-hexene, and 1-octene. Among the at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms, ethylene and 1-butene are most preferable.
When the propylene (co) polymer (YH) is a copolymer, the content of at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms is supplied to the polymerization tank. Usually, it is carried out by appropriately adjusting the monomer ratio (eg, the ratio of ethylene to propylene). The copolymerization characteristics of the catalyst to be used may be examined in advance, and the monomer feed ratio may be adjusted so that the gas composition in the polymerization tank has a value corresponding to the desired comonomer content.
From the viewpoint of heat resistance, the propylene (co) polymer (YH) is preferably a propylene homopolymer.

III-1-2. Characteristic (YH-ii): MFR
The propylene (co) polymer (YH), which is a constituent component of the impact copolymer (Y) according to the present invention, needs to have an MFR of 1 to 100 g / 10 min.
One of the main points of the design concept of the polypropylene resin composition for extrusion foaming of the present invention is, as described above, a specific long characteristic that has a relatively high MFR and MT is not too high (and not too low). Polypropylene (X) having chain branching is to be combined with impact copolymer (Y) that is neither too high nor too low in fluidity.
The propylene-ethylene copolymer (YC), which is a component of the impact copolymer (Y), requires a high viscosity (= low fluidity) to suppress the formation of a structure under shear as described later. In order to ensure fluidity as the impact copolymer (Y), it is a normal idea to lower the viscosity of the propylene (co) polymer (YH), that is, to increase the MFR.
Here, the structure formation means that the polypropylene (X) having a long chain branch is a polymer chain in which the movement around the polypropylene having the long chain branch is inhibited under the condition that shearing is applied as in a melt extruder. In other words, it is a structure formation that forms a so-called shishi kebab structure (or a precursor thereof).
However, if the MFR of the propylene (co) polymer (YH) is too high, the viscosity difference between the propylene (co) polymer (YH) and the propylene-ethylene copolymer (YC) increases, and the propylene-ethylene copolymer There arises a problem that the dispersion failure of (YC) occurs, and the effect of suppressing the formation of the structure under shear becomes small. In addition, there is a problem that the bright spot is deteriorated and the appearance of the final product is deteriorated. Therefore, it is important to set the MFR of the propylene (co) polymer (YH) within a specific range.
For example, Patent Document 12 includes a low MFR polypropylene, a specific prescribed propylene / ethylene block copolymer, a polypropylene containing an olefin polymer having a very high intrinsic viscosity, and a hydrogen of a styrene / conjugated diene block copolymer. A polypropylene resin composition comprising a thermoplastic resin such as an additive is disclosed, and a polypropylene containing an olefin polymer having an extremely high intrinsic viscosity corresponds to a high MT polypropylene, but a propylene / ethylene block copolymer Has a high MFR of the propylene polymer portion and a high MFR of the propylene / ethylene block copolymer, and conversely, it is designed to be combined with a high MT polypropylene having a low MFR. This is a typical example of the conventional technical idea and is completely opposite to the design concept of the present invention.

The MFR of the propylene (co) polymer (YH), which is a constituent component of the impact copolymer (Y) according to the present invention, is 1 to 100 g / 10 minutes, but if the MFR is too higher than this range, propylene-ethylene This is not preferable because the dispersion of the copolymer (YC) is deteriorated and the appearance of the product is deteriorated. Regarding the upper limit, the MFR of the propylene (co) polymer (YH) is more preferably 70 g / 10 min or less, still more preferably 60 g / 10 min or less, and most preferably 50 g / 10 min or less. On the other hand, if the MFR is too low, the fluidity of the impact copolymer (Y) decreases, the spreadability of the polypropylene resin composition for extrusion foaming deteriorates, foam breakage during foaming, poor surface appearance of the sheet or film, Is not preferable because it leads to poor appearance of the final product. Regarding the lower limit, the MFR of the propylene (co) polymer (YH) is more preferably 5 g / 10 min or more, further preferably 10 g / 10 min or more, and most preferably 15 g / 10 min or more.
As a specific method for adjusting the MFR to the above range, a method of changing the amount of hydrogen added during polymerization can be mentioned. The details are the same as the description of the characteristics (X-iii) of polypropylene (X), and will be omitted.
In addition, the measuring method of MFR is the same as the measuring method of MFR in the above-mentioned polypropylene (X).

III-2. Propylene-ethylene copolymer (YC)
The propylene-ethylene copolymer (YC) which is a constituent component of the impact copolymer (Y) according to the present invention suppresses the formation of a structure under shearing of the polypropylene (X) having a long chain branch in the polypropylene resin composition for extrusion foaming. Two points, amorphous and motility, are important control points.

Due to its molecular structure, polypropylene (X) having long chain branching has a very high MT and a high degree of strain hardening as compared with linear polypropylene. This is a phenomenon that occurs because long chain branching is entangled with other polymer chains and restrains both movements. On the other hand, under conditions where shearing is applied as in an extruder, polypropylene having long chain branching is used. The polymer chains that are blocked from the central movement gradually gather to form a certain structure.
This structure is a so-called shishi kebab structure (or a precursor thereof), has a higher strength than other parts of the polypropylene or polypropylene resin composition, and behaves as a foreign substance. For this reason, it exhibits a resistance to spreading, and in the case of extrusion foaming, the surface of the sheet or film is roughened, or when the cells grow during foaming, the cell partition walls are broken and the open cell ratio is increased. Or other problems will occur. That is, in extrusion foam molding, it is desirable that the polypropylene chains having long chain branches are widely dispersed in the polypropylene or polypropylene resin composition, and it is not desirable to localize to form a structure. It is a state.
In order to suppress structure formation, it is a polymer chain that does not become a crystal itself, and its own mobility is low (and it is difficult for itself to cause structure formation). A polymer chain that cannot move to the position where the structure is formed may be present. That is, an amorphous high molecular weight polymer is considered effective. This is a propylene-ethylene copolymer (YC) which is a constituent component of the impact copolymer (Y), and two points of amorphous and mobility are important control points.

  The propylene-ethylene copolymer (YC), which is a constituent component of the impact copolymer (Y) according to the present invention, is a copolymer of propylene and ethylene, but does not coexist with other monomers as long as the effects of the present invention are not impaired. A polymerized product may be used. Specifically, at least one α-olefin selected from the group consisting of α-olefins having 4 to 10 carbon atoms can be used. Specific examples of such α-olefins include 1-butene, 1-hexene, 1-octene and the like. Among these, 1-butene is more preferable. When the propylene-ethylene copolymer (YC) includes monomer units other than propylene and ethylene, the content thereof is, for example, 10 to 40 wt% so that the propylene-ethylene copolymer (YC) does not exhibit crystallinity. It is preferable that

III-2-1. Characteristic (YC-i): Ethylene content in propylene-ethylene copolymer (YC) The propylene-ethylene copolymer (YC), which is a component of the impact copolymer (Y) according to the present invention, is propylene-ethylene copolymer. The ethylene content in the coalescence (YC) is 10 to 90 wt% (provided that the total amount of propylene-ethylene copolymer (YC) is 100 wt%).
The ethylene content in the propylene-ethylene copolymer (YC) is an important factor that determines the amorphous nature of the propylene-ethylene copolymer (YC). If the ethylene content in the propylene-ethylene copolymer (YC) is out of the above range, the propylene-ethylene copolymer (YC) itself becomes crystalline, and the structure formation under shearing cannot be suppressed. It is not preferable.

The propylene-ethylene copolymer (YC) preferably has a higher dispersibility in the impact copolymer (Y). From this viewpoint, the ethylene content in the propylene-ethylene copolymer (YC) should not be too high. preferable. Specifically, the ethylene content in the propylene-ethylene copolymer (YC) is preferably 70 wt% or less, more preferably 60 wt% or less, still more preferably 50 wt% or less, and most preferably 40 wt% or less. On the other hand, regarding the lower limit of the ethylene content, when the crystallinity distribution of the propylene-ethylene copolymer (YC) is taken into consideration, the effect of suppressing the formation of the structure under shear can be expected when it is not too low. Specifically, the ethylene content in the propylene-ethylene copolymer (YC) is preferably 15 wt% or more, more preferably 20 wt% or more, and most preferably 25 wt% or more. Since the propylene-ethylene copolymer (YC) is well dispersed in the impact copolymer (Y), the dispersibility of the polypropylene (X) and the propylene-ethylene copolymer (YC) is also improved. obtain.
As a specific method of adjusting the ethylene content in the propylene-ethylene copolymer (YC) to the above range, a method of changing the ratio of propylene and ethylene added during polymerization can be mentioned. When producing a propylene-ethylene copolymer (YC), since propylene and ethylene are copolymerized, ethylene in the propylene-ethylene copolymer (YC) depends on the ratio of propylene and ethylene in the polymerization tank. The content is determined. The relationship between the ratio of propylene and ethylene in the polymerization tank and the ethylene content in the propylene-ethylene copolymer (YC) varies depending on the polymerization conditions such as the catalyst and temperature. It is necessary to know in advance the relationship between the ratio of propylene and ethylene and the ethylene content in the propylene-ethylene copolymer (YC), and to adjust the ratio of propylene and ethylene so that the desired ethylene content is obtained. It is easy for contractors. In order to adjust the ratio of propylene and ethylene in the polymerization tank, the ratio of propylene and ethylene added during polymerization may be adjusted.

III-2-2. Characteristic (YC-ii): Intrinsic Viscosity Propylene-ethylene copolymer (YC), which is a component of impact copolymer (Y) according to the present invention, has an intrinsic viscosity of 5 to 20 dl / g measured in decalin at 135 ° C. is there.
The intrinsic viscosity of the propylene-ethylene copolymer (YC) is an important factor that determines the mobility of the propylene-ethylene copolymer (YC). As described above, in order to suppress structure formation under shearing, the propylene-ethylene copolymer (YC) must have a low mobility and therefore its intrinsic viscosity must be high. That is, when the intrinsic viscosity of the propylene-ethylene copolymer (YC) is too low, it is not preferable because the formation of the structure under shear cannot be suppressed.
The lower limit of the intrinsic viscosity of the propylene-ethylene copolymer (YC) is preferably 6 dl / g or more, more preferably 7 dl / g or more, and most preferably 8 dl / g or more. On the other hand, if the upper limit of the intrinsic viscosity of the propylene-ethylene copolymer (YC) is too high, the impact copolymer (Y) will cause poor dispersion and the effect of suppressing the formation of the structure under shear may be reduced. This is not preferable because a problem of bright spots occurs. Specifically, the intrinsic viscosity of the propylene-ethylene copolymer (YC) is preferably 16 dl / g or less, more preferably 13 dl / g or less, and most preferably 10 dl / g or less.
As a specific method for adjusting the intrinsic viscosity of the propylene-ethylene copolymer (YC) to the above range, a method of changing the amount of hydrogen added during polymerization can be mentioned. The details are the same as the description of the characteristics (X-iii) of polypropylene (X), and will be omitted.

III-3. Impact copolymer (Y)
The impact copolymer (Y) according to the present invention comprises the propylene (co) polymer (YH) and the propylene-ethylene copolymer (YC) described above, and further satisfies the characteristics (Yi). .

III-3-1. Characteristic (Yi): Content of propylene-ethylene copolymer (YC) in impact copolymer (Y) The impact copolymer (Y) according to the present invention comprises a propylene-ethylene copolymer in impact copolymer (Y) ( The content of YC) is 1 wt% or more and less than 50 wt% (provided that the total amount of impact copolymer (Y) is 100 wt%).
The propylene-ethylene copolymer (YC), which is a constituent component of the impact copolymer (Y), is very important as described above, in which the polypropylene (A) having a long chain branch has a function of suppressing the formation of a structure under shear. If the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is too small, this structure formation inhibitory effect is reduced, which is not preferable.
The lower limit of the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is preferably 5 wt% or more, more preferably 10 wt% or more, still more preferably 15 wt% or more, and most preferably 20 wt% or more. It is. On the contrary, if the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is too large, the crystallinity of the polypropylene resin composition for extrusion foaming is lowered, so that the heat resistance and rigidity are lowered. It is not preferable. Moreover, when there is too much content of a propylene-ethylene copolymer (YC), it will lead to making MFR of a propylene (co) polymer (YH) relatively high, and dispersion | distribution of a propylene-ethylene copolymer (YC) Is inferior, and the effect of suppressing the formation of the structure is lowered. On the other hand, the upper limit of the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is preferably 45 wt% or less, more preferably 40 wt% or less, still more preferably 35 wt% or less, and most preferably 30 wt%. % Or less.
Since the total amount of impact copolymer (Y) is 100 wt%, the content of propylene (co) polymer (YH) in impact copolymer (Y) is from 100 wt% to the content of propylene-ethylene copolymer (YC). Reduced value.

As a specific method for adjusting the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) to the above range, when the impact copolymer (Y) is produced, the propylene (co) polymer (YH And a method for adjusting the production amount of the propylene-ethylene copolymer (YC).
Since the impact copolymer (Y) is a reactor blend, there are a process for producing a propylene (co) polymer (YH) and a process for producing a propylene-ethylene copolymer (YC) during the production process. For example, when the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is lowered, the relative amount of the propylene (co) polymer (YH) is increased to increase the propylene-ethylene copolymer (YC). What is necessary is just to reduce a relative amount. In that case, the production amount of the propylene-copolymer (YC) may be reduced without changing the production amount of the propylene (co) polymer (YH), or the propylene (co) polymer (YH) The production amount may be increased and the production amount of the propylene-ethylene copolymer (YC) may not be changed, or the production amount of the propylene (co) polymer (YH) may be increased and the propylene-ethylene copolymer (YC) ) May be reduced. When increasing the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y), the opposite concept may be used. In order to increase the production amount of the propylene (co) polymer (YH), the residence time in the step of producing the propylene (co) polymer (YH) may be increased, or the polymerization pressure may be increased. In order to reduce the production amount of the propylene (co) polymer (YH), the reverse operation may be performed. The same applies when the production amount of the propylene-ethylene copolymer (YC) is changed. Further, when a polymerization inhibitor such as ethanol or oxygen is used in the step of producing a propylene-ethylene copolymer (YC), it can also be controlled by increasing or decreasing the amount of addition. If the addition amount of the polymerization inhibitor is increased, the production amount of the propylene-ethylene copolymer (YC) is decreased. The reverse is also possible.

III-3-2. Characteristic (Y-ii): MFR
In the impact copolymer (Y) of the present invention, the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is 1 wt% or more and less than 50 wt% with respect to the total amount of the impact copolymer (Y). Among these impact copolymers (Y), those satisfying the following characteristics (Y-ii) are preferable.
Characteristic (Y-ii): MFR is 0.1 to 20 g / 10 min.

The MFR of the impact copolymer (Y) is preferably 0.1 to 20 g / 10 minutes, more preferably 0.5 to 10 g / 10 minutes, still more preferably 0.7 to 5 g / 10 minutes, and most preferably Is 1 to 3 g / 10 min. It is preferable that the MFR of the impact copolymer (Y) is within the above range because the extrusion behavior is stable and neck-in can be suppressed.
Next, a method for controlling the MFR of the impact copolymer (Y) will be described. Since the impact copolymer (Y) according to the present invention is a reactor blend of the above-described propylene (co) polymer (YH) and propylene-ethylene copolymer (YC), the MFR of the impact copolymer (Y) is changed. The method of changing the MFR of the propylene (co) polymer (YH), the method of changing the MFR of the propylene-ethylene copolymer (YC), and the propylene-ethylene copolymer in the impact copolymer (Y) There are three methods of changing the content of (YC). As is clear from the characteristics (X-iii) and (YC-ii), the MFR of the propylene (co) polymer (YH) has a higher value than the MFR of the propylene-ethylene copolymer (YC). Therefore, when the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is increased, the amount of the component having a low MFR increases, so that the MFR of the impact copolymer (Y) decreases. The reverse is also true. Therefore, the MFR of the impact copolymer (Y) can be controlled by changing the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y). The method for changing the MFR of the propylene (co) polymer (YH) and the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is as described above. Similarly to the propylene (co) polymer (YH), the MFR of the propylene-ethylene copolymer (YC) can also be controlled by changing the amount of hydrogen added.
In addition, the measuring method of MFR is the same as the measuring method of MFR in the above-mentioned polypropylene (X).

III-3-3. Method for Determining the Index of Impact Copolymer (Y) Impact copolymer (Y) is generally a reactor blend of a propylene (co) polymer and a propylene-ethylene copolymer, and usually comprises a step of producing a propylene (co) polymer. It implements previously, and the process of manufacturing a propylene-ethylene copolymer is performed after that.
Therefore, it is usually not possible to directly analyze only the propylene-ethylene copolymer. There are two directly analyzable, propylene (co) polymers and impact copolymers as a whole. As described above, there are two methods for determining the index of the propylene-ethylene copolymer that cannot be directly analyzed. One is a method using fractionation. This is a method in which a propylene (co) polymer and a propylene-ethylene copolymer, which are constituent components, are separated using a fractionation technique such as CXS, and an index is obtained individually. Another is the analysis of propylene (co) polymer and impact copolymer as a whole, which can be directly analyzed, and the production balance of propylene (co) polymer and propylene-ethylene copolymer. This is a method for obtaining an index of a copolymer.

In the present invention, the index of impact copolymer (Y), that is, the content of propylene-ethylene copolymer (YC) in impact copolymer (Y), the intrinsic viscosity and the ethylene content of propylene-ethylene copolymer (YC). Defines that the value obtained by the following method is used.
Procedure 1. The impact copolymer (Y) is separated into a soluble component (CXS component) and an insoluble component (CXIS component) at 25 ° C. xylene, and the CXS component is analyzed by ¹³ C-NMR to determine the ethylene content.
Procedure 2. As a result of analysis by ¹³ C-NMR, when the ethylene content of the CXS component is 15 wt% or more, the CXS component is regarded as a propylene-ethylene copolymer (YC). That is, the CXS value (wt%) is the propylene-ethylene copolymer (YC) content (wt%), and the CXS component ethylene content is the ethylene content in the propylene-ethylene copolymer (YC). Similarly, the intrinsic viscosity of the propylene-ethylene copolymer (YC) is determined by analyzing this CXS component.
Procedure 3. As a result of analysis by ¹³ C-NMR, when the ethylene content of the CXS component is less than 15 wt%, the analysis results of the entire propylene (co) polymer and impact copolymer, and the propylene (co) polymer and propylene-ethylene Using the production balance of the copolymer, the content of the propylene-ethylene copolymer (YC), the intrinsic viscosity and the ethylene content of the propylene-ethylene copolymer (YC) are determined.
Hereinafter, the details will be described in order.

(1) Fractionation method using xylene at 25 ° C. Using the method described in the section of properties (X-iv) of polypropylene (X), CXS of impact copolymer (Y) is measured, and xylene soluble in xylene (CXS) Ingredient) Collect. Using this CXS component, the ethylene content is determined by the method described in the following (2).

(2) Method for measuring ethylene content by ¹³ C-NMR In measuring the ethylene content of the CXS component, the following measurement conditions are used.
[ ¹³ C-NMR measurement conditions for ethylene content measurement]
Model: GSX-400 manufactured by JEOL Ltd.
Solvent: o-dichlorobenzene + heavy benzene (4: 1 (volume ratio))
Concentration: 100 mg / mL
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more

The spectrum may be assigned with reference to Macromolecules 17, 1950 (1984), for example. The attribution of spectra measured under the above conditions is as shown in Table 1. Table 1 Symbols such as S _{alpha alpha} in accordance with notation Carman et al (Macromolecules 10,536 (1977)), P represents respectively the methyl carbon, S is methylene carbon, T is a methine carbon.

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six kinds of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. As described in Macromolecules 15, 1150 (1982), the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads. Therefore,
[PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is. Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ . By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
In addition, when the impact copolymer (Y) is produced using a metallocene catalyst, a small amount of propylene heterogeneous bonds (2,1-bonds and / or 1,3-bonds) are generated. Produces a strong peak.

In order to obtain an accurate ethylene content, it is necessary to include the peaks derived from these heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from the heterogeneous bonds. Since the amount of ethylene is small, the ethylene content is expressed by the relational expressions (1) to (7) as in the analysis of the copolymer produced with a Ziegler-Natta catalyst that does not substantially contain a heterogeneous bond. To ask.
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X / 100)} × 100
Here, X is the ethylene content in mol%.

(3) Method for obtaining intrinsic viscosity by analysis of CXS component As a result of analyzing the CXS component by ¹³ C-NMR, if the ethylene content of the CXS component is 15 wt% or more, propylene-ethylene copolymerization by solvent fractionation with 25 ° C. xylene It is determined that the merger (YC) is correctly separated. Therefore, as described in Procedure 2, the value of CXS (wt%) is the content of propylene-ethylene copolymer (YC) (wt%), and the ethylene content of the CXS component is in the propylene-ethylene copolymer (YC). Of ethylene content. Similarly, the intrinsic viscosity of the propylene-ethylene copolymer (YC) is also determined by analyzing this CXS component.
Specifically, the intrinsic viscosity is measured using the CXS component recovered as described above. The intrinsic viscosity is measured using an Ubbelohde capillary viscometer at a temperature of 135 ° C. and a decalin solvent.

(4) Method of calculating from the analysis results of the entire propylene (co) polymer and impact copolymer As a result of analyzing the CXS component by ¹³ C-NMR, when the ethylene content of the CXS component is less than 15 wt%, the propylene-ethylene copolymer Since the crystallinity of the polymer (YC) cannot be ignored, it must be considered that the propylene (co) polymer (YH) and the propylene-ethylene copolymer (YC) cannot be fractionated with 25 ° C. xylene.
In this case, the index of impact copolymer (Y) is determined by the following procedures (4) -1 to 3.

(4) -1. Determination of content of propylene-ethylene copolymer (YC) in impact copolymer (Y) First, the content of propylene-ethylene copolymer (YC) in impact copolymer (Y) is determined from the production balance. Specifically, the production amount of the step of producing a propylene (co) polymer (YH) (hereinafter referred to as PR-YH. The unit is T / h) and the propylene-ethylene copolymer (YC) are produced. The production amount of the process (hereinafter referred to as PR-YC. The unit is T / h) was determined, and using both values, the propylene-ethylene copolymer in the impact copolymer (Y) from the following formula (III) The content of (YC) ([YC], unit is wt%) is determined.
[YC] = PR−YC ÷ (PR−YH + PR−YC) × 100 (III)

PR-YH and PR-YC are generally obtained from heat balance. When there is no particular obstacle, in the present invention, as a result of ¹³ C-NMR, when the ethylene content of the CXS component is less than 15 wt%, PR-YH and PR-YC are determined from heat balance. When it is practically impossible to obtain PR-YC from heat balance, the production amount of the entire impact copolymer (Y) instead of PR-YC (hereinafter referred to as PR-Y. The unit is T / h. ) To determine the content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) from the following formula (IV).
[YC] = (PR−Y−PR−YH) ÷ PR−Yx100 (IV)

(4) -2. Determination of ethylene content in propylene-ethylene copolymer (YC) Next, the ethylene content ([E-YC], unit is wt%) in the propylene-ethylene copolymer (YC) is determined. At this time, in addition to the content of propylene-ethylene copolymer (YC) in the impact copolymer (Y) obtained in (4) -1 ([YC], unit is wt%), propylene (co) weight The ethylene content ([E-YH], unit is wt%) in the coalescence (YH) and the ethylene content ([E-Y], unit is wt%) in the impact copolymer (Y) are used. Specifically, it is calculated from the following equation (V).
[E−YC] = [[EY] − {[E−YH] × (100− [YC]) ÷ 100}] ÷ [YC] × 100 (V)
Here, [E-YH] and [EY] can be obtained directly from analysis by ¹³ C-NMR. The analysis conditions and analysis method in this case are as described in the section of (2) Method for measuring ethylene content by ¹³ C-NMR.

(4) -3. Determination of Intrinsic Viscosity of Propylene-Ethylene Copolymer (YC) Finally, the intrinsic viscosity ([η-YC], unit is dl / g) of the propylene-ethylene copolymer (YC) is determined. In this case, in addition to the content of propylene-ethylene copolymer (YC) in the impact copolymer (Y) obtained in (4) -1 ([YC], unit is wt%), propylene (co) The intrinsic viscosity ([η-YH], unit is dl / g) of the polymer (YH) and the intrinsic viscosity ([η-Y], unit is dl / g) of the impact copolymer (Y) are used.
Specifically, it is calculated from the following formula (VI).
[Η−YC] = [[η−Y] − {[η−YH] × (100− [YC]) ÷ 100}] ÷ [YC] × 100 (VI)
Here, the intrinsic viscosity [η-YH] of the propylene (co) polymer (YH) and the intrinsic viscosity [η-Y] of the impact copolymer (Y) were measured using a Ubbelohde capillary viscometer at a temperature of 135 ° C. and a decalin solvent. It shall be performed under the conditions of.

IV. Method for Producing Impact Copolymer (Y) The impact copolymer (Y) in the present invention satisfies the above characteristics (Y-i) and has the above characteristics (YH-i) to (YH-ii). It consists of a propylene (co) polymer (YH) that satisfies the above and a propylene-ethylene copolymer (YC) that satisfies the above characteristics (YC-i) to (YC-ii), and has this requirement. If there is, the manufacturing method is not particularly limited.
Hereinafter, an appropriate form for producing the impact copolymer (Y) of the present invention will be described with specific examples.

IV-1. Catalyst Any catalyst can be used as the catalyst for producing the impact copolymer (Y) according to the present invention, but the propylene-ethylene copolymer (Y) satisfying the characteristics (YC-i) to (YC-ii). From the viewpoint of producing 2) as a constituent, it is preferable to use a Ziegler-Natta catalyst. When the Ziegler-Natta catalyst is used, a specific method for producing the catalyst is not particularly limited, but as an example, a catalyst disclosed in JP 2007-254671 A can be exemplified.
Specifically, as representative examples of the Ziegler-Natta catalyst suitable for the production of the impact copolymer (Y) according to the present invention, the following components:
(ZN-1): a solid component containing titanium, magnesium and halogen as essential components,
(ZN-2): an organoaluminum compound,
(ZN-3): electron donor,
The catalyst which consists of can be mentioned.

(1) Solid component (ZN-1)
The solid component (ZN-1), which is a component of the Ziegler-Natta catalyst suitable for producing the impact copolymer (Y) according to the present invention, is titanium (ZN-1a), magnesium (ZN-1b), halogen (ZN-). 1c) is contained as an essential component, and an electron donor (ZN-1d) can be used as an optional component. Here, “containing as an essential component” indicates that any component may be included in any form within the range not impairing the effects of the present invention, in addition to the listed three components. . This will be described in detail below.

(ZN-1a): Titanium Any arbitrary titanium compound can be used as a titanium source. Representative examples include compounds disclosed in JP-A-3-234707. With respect to the valence of titanium, a titanium compound having any valence of tetravalent, trivalent, divalent, and zero can be used, but it is desirable to use a tetravalent titanium compound.

(ZN-1b): Magnesium Any magnesium compound can be used as the magnesium source. Representative examples include compounds disclosed in JP-A-234707. In general, magnesium chloride, diethoxymagnesium, metallic magnesium, and butylmagnesium chloride are often used.

(ZN-1c): Halogen As the halogen, fluorine, chlorine, bromine, iodine, and a mixture thereof can be used. Of these, chlorine is particularly preferred.

(ZN-1d): Electron Donor The solid component (ZN-1) may contain an electron donor as an optional component. Representative examples of the electron donor (ZN-1d) include compounds disclosed in JP-A No. 2004-124090. In general, organic acids and inorganic acids, and derivatives thereof (esters, acid anhydrides, acid halides, amides), ether compounds, ketone compounds, aldehyde compounds, alcohol compounds, amine compounds, It is desirable to use etc.
Among these, preferred are phthalate compounds represented by diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, diheptyl phthalate, phthalate halide compounds represented by phthaloyl dichloride, 2-n- Malonic acid ester compounds having one or two substituents at the 2-position such as butyl-diethyl malonate, one or two substituents at the 2-position such as 2-n-butyl-diethyl succinate, or 2 Succinic acid ester compounds having one or more substituents at each of the 3-position and 2-isopropyl-2-isobutyl-1,3-dimethoxypropane or 2-isopropyl-2-isopentyl-1,3-dimethoxypropane Aliphatic polyhydric ether compounds represented by 1,3-dimethoxypropane having one or two substituents at the 2-position , Polyvalent ether compounds having 9,9-bis radical of aromatic typified by (methoxymethyl) fluorene in the molecule, and the like.

(2) Organoaluminum compound (ZN-2)
As the organoaluminum compound (ZN-2), compounds disclosed in JP-A No. 2004-124090 can be used. In general, it is desirable to use a compound represented by the following general formula (5).
R ⁹ _c AlX _d (OR ¹⁰ ) _e (5)
(In the general formula (5), R ⁹ represents a hydrocarbon group. X represents a halogen or a hydrogen atom. R ¹⁰ represents a hydrocarbon group or a bridging group by Al. C ≧ 1, 0 ≦ d. ≦ 2, 0 ≦ e ≦ 2, c + d + e = 3)

  Specific examples include trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum chloride, diethylaluminum ethoxide, methylalumoxane, and the like.

(3) Electron donor (ZN-3)
Examples of the electron donor (ZN-3) include an organosilicon compound (ZN-3a) having an alkoxy group or a compound (ZN-3b) having at least two ether bonds.

(ZN-3a): Organosilicon compound having an alkoxy group As the organosilicon compound (ZN-3a) having an alkoxy group, which is a constituent of a Ziegler-Natta catalyst suitable for producing the impact copolymer (Y) according to the present invention, The compounds disclosed in JP-A-2004-124090 can be used. In general, it is desirable to use a compound represented by the following general formula (3).
R ³ R ⁴ _a Si (OR ⁵ ) _b (3)
(In General Formula (3), R ³ represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. R ⁴ is selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group, and a heteroatom-containing hydrocarbon group. R ⁵ represents a hydrocarbon group, 0 ≦ a ≦ 2, 1 ≦ b ≦ 3, a + b = 3.)

Specific examples include t-Bu (Me) Si (OMe) ₂ , t-Bu (Me) Si (OEt) ₂ , t-Bu (Et) Si (OMe) ₂ , t-Bu (n-Pr). _{Si (OMe) 2, c-} Hex (Me) Si (OMe) 2, c-Hex (Et) Si (OMe) 2, c-Pen 2 Si (OMe) 2, i-Pr 2 Si (OMe) 2, _{i-Bu 2 Si (OMe)} 2, i-Pr (i-Bu) Si (OMe) 2, n-Pr (Me) Si (OMe) 2, t-BuSi (OEt) 3, (Et 2 n) 2 _{Si (OMe) 2, Et 2} N-Si (OEt) 3, and the like.

(ZN-3b): Compound having at least two ether bonds As the compound having at least two ether bonds (ZN-3b), compounds disclosed in JP-A-3-294302 and JP-A-8-333413 Etc. can be used. In general, it is desirable to use a compound represented by the following general formula (4).
_{^{R 8 O-C (R 7}} ) 2 -C (R 6) 2 -C (R 7) 2 -OR 8 ... (4)
(In General Formula (4), R ⁶ and R ⁷ represent any free radical selected from the group consisting of a hydrogen atom, a hydrocarbon group, and a heteroatom-containing hydrocarbon group. R ⁸ represents a hydrocarbon group or a hetero group. Represents an atom-containing hydrocarbon group.)

  As specific examples, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2-isopropyl -2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 9,9-bis (methoxymethyl) fluorene, and the like.

(4) Prepolymerization The catalyst exemplified above may be prepolymerized before being used in the main polymerization. Prior to the polymerization process, a small amount of polymer is generated around the catalyst in advance, so that the catalyst becomes more uniform and the generation amount of fine powder can be suppressed.
As the monomer in the prepolymerization, compounds disclosed in JP-A No. 2004-124090 can be used. Specifically, ethylene, propylene, 3-methylbutene-1, 4-methylpentene-1, styrene, divinylbenzenes, and the like are particularly preferable.
The reaction conditions for the catalyst exemplified above and the above monomer are not particularly limited, but generally are preferably within the following ranges.
The amount of prepolymerization is in the range of 0.001 to 100 g, preferably 0.1 to 50 g, more preferably 0.5 to 10 g, based on 1 g of the solid component (ZN-1). The reaction temperature during prepolymerization is -150 to 150 ° C, preferably 0 to 100 ° C. And it is desirable to make the reaction temperature at the time of preliminary polymerization lower than the polymerization temperature at the time of main polymerization. In general, the reaction is preferably carried out with stirring, and an inert solvent such as hexane or heptane can also be present.

IV-2. Polymerization Method (1) Sequential Polymerization Next, the production method of the impact copolymer (Y) according to the present invention will be described in detail.
The impact copolymer (Y) according to the present invention is a reactor blend composed of a propylene (co) polymer (YH) and a propylene-ethylene copolymer (YC). It is necessary to produce two polymer components, a co) polymer (YH) and a propylene-ethylene copolymer (YC). From the viewpoint that the propylene-ethylene copolymer (YC) having a relatively high molecular weight and low viscosity and MFR is neatly dispersed in the propylene (co) polymer (YH) to express the original performance of the impact copolymer (Y). It is desirable to produce both the components by sequential polymerization.

Specifically, it is desirable to polymerize the propylene-ethylene copolymer (YC) in the second step after polymerizing the propylene (co) polymer (YH) in the first step. Although it is possible to reverse the order of production, the propylene-ethylene copolymer (YC) has an ethylene content in the range of 10 to 90 wt% from the definition of (YC-i), Since it is a polymer with low crystallinity, if it is produced in the first step, there is a high possibility of causing production troubles such as adhesion inside the polymerization tank or clogging of the transfer pipe, which is not preferable.
When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally desirable to use a continuous method from the viewpoint of productivity.
In the case of the batch method, the propylene (co) polymer (YH) and the propylene-ethylene copolymer (YC) are separately polymerized using a single polymerization reactor by changing the polymerization conditions with time. It is possible. As long as the effect of the present invention is not impaired, a plurality of polymerization reactors may be connected in parallel.
In the case of a continuous process, it is necessary to individually polymerize propylene (co) polymer (YH) and propylene-ethylene copolymer (YC), so it is necessary to use a production facility in which two or more polymerization reactors are connected in series There is. The polymerization reactor corresponding to the first step for producing the propylene (co) polymer (YH) and the polymerization reactor corresponding to the second step for producing the propylene-ethylene copolymer (YC) are in a series relationship. Although it is necessary, a plurality of polymerization reactors may be connected in series and / or in parallel for each of the first step and the second step.

(2) Polymerization process Any polymerization process can be used.
The reaction phase may be a method using a liquid medium or a method using a gas medium. Specific examples include a slurry method, a bulk method, and a gas phase method. Although it is possible to use supercritical conditions as intermediate conditions between the bulk method and the gas phase method, they are substantially equivalent to the gas phase method, and are therefore included in the gas phase method without particular distinction. In the case of a multi-tank continuous polymerization process, a bulk polymerization reactor may be followed by a gas phase polymerization reactor. In this case, it will be referred to as a bulk method in accordance with the practice of the industry. In the case of the batch method, the first step may be performed by a bulk method, and the second step may be performed by a vapor phase method. This case is also referred to as a bulk method. As described above, the reaction phase is not particularly limited, but the slurry method has a problem that production costs are generally increased because of the use of an organic solvent such as hexane and heptane because there are many attached facilities. Therefore, it is more desirable to use a bulk method or a gas phase method.
Various processes have been proposed for the bulk method and the gas phase method. Although there is a difference in the stirring (mixing) method and the heat removal method, the present invention does not limit the particular process type in this respect.

(3) General polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a commonly used temperature range. Specifically, a range of 0 ° C to 200 ° C, preferably 40 ° C to 100 ° C can be used.
Although the polymerization pressure varies depending on the process to be selected, it can be used without any problem as long as it is in a pressure range usually used. Specifically, a range of greater than 0 to 200 MPa, preferably 0.1 to 50 MPa can be used. At this time, there is no problem even if an inert gas such as nitrogen coexists.
In the second step of producing a propylene-ethylene copolymer (YC), a polymerization inhibitor such as ethanol or oxygen can be added. When such a polymerization inhibitor is used, not only the polymerization amount in the second step can be easily controlled, but also the properties of the polymer particles can be improved.

V. Polypropylene resin composition The polypropylene resin composition of the present invention comprises polypropylene (X) 5 to 99 wt% satisfying the above characteristics (Xi) to (X-iv), and the above characteristics (YH-i) to (YH). A propylene (co) polymer (YH) satisfying -ii) and a propylene-ethylene copolymer (YC) satisfying characteristics (YC-i) to (YC-ii), and further comprising characteristics (Yi) A resin composition (Z) comprising 1 to 95 wt% of an impact copolymer (Y) to be satisfied (provided that the total of polypropylene (X) and impact copolymer (Y) is 100 wt%), and has the following characteristics (Z- i) to (Z-ii) are satisfied.
Characteristic (Zi): MFR is 0.1 to 20 g / 10 min.
Characteristic (Z-ii): Melt tension (MT) measured at 230 ° C. is 1 to 7 g.
Hereinafter, the details will be described in order.

V-1. Production Method of Resin Composition A known method can be used as a method for preparing the polypropylene resin composition (Z) of the present invention. For example, a resin composition can be prepared by mixing polypropylene (X), impact copolymer (Y), and any additive described below with a dry blend, a Henschel mixer, or the like. These may be melt kneaded by a single screw extruder, a twin screw kneader, a kneader or the like.
At this time, in order to use for extrusion molding, it is preferable that the resin composition is melt-kneaded and pelletized. As a method of pelletizing the resin composition,
a. A mixture of polypropylene (X), impact copolymer (Y) and optional additives is melt-kneaded and pelletized.
b. A mixture of polypropylene (X) and optional additives is melt-kneaded and pelletized, and the impact copolymer (Y) and optional additives are further mixed with polypropylene (X) composition pellets, and then melt-kneaded and pelletized. To do.
b '. A mixture of the impact copolymer (Y) and an optional additive is melt-kneaded and pelletized, and further mixed with polypropylene (X) and an optional additive, followed by melt-kneading.
c. A mixture of polypropylene (X) and optional additives and a mixture of impact copolymer (Y) and optional additives are melt-kneaded to obtain each pellet, and the resulting pellets are mixed. To do.
d. A mixture of polypropylene (X) and optional additives and a mixture of impact copolymer (Y) and optional additives are melt-kneaded to obtain each pellet, and the resulting pellets are mixed. Further, this is melt kneaded and pelletized.
Such a method can be used.

  Here, the polypropylene resin composition of the present invention satisfies the following characteristics (Zi) to (Z-ii), but the MFR defined by the characteristics (Zi) and the characteristics (Z- The MT specified in ii) is a value measured by using both melt-kneaded polypropylene (X) and impact copolymer (Y). Therefore, when these are simply mixed and used, or polypropylene (X) and impact copolymer (Y) are mixed (dry blended) as in c, and both are used as an extrusion foaming resin composition without melt-kneading. In some cases, polypropylene (X), impact copolymer (Y), optional components are melt-kneaded separately using the same formulation, and MFR and MT are measured using the obtained pellets. These values are determined as the MFR and MT values of the polypropylene resin composition for extrusion foaming. In this case, melt kneading is performed using the method described in the examples described later.

V-2. Content of polypropylene (X) and impact copolymer (Y) The content of polypropylene (X) in the polypropylene resin composition of the present invention is 5 to 99 wt%. When a more preferable range is exemplified, the content of polypropylene (X) is more preferably 10 to 90 wt%, and still more preferably 15 to 80 wt%. Correspondingly, the content of the impact copolymer (Y) in the polypropylene resin composition is 1 to 95 wt%, preferably 10 to 90 wt%, more preferably 20 to 85 wt% (polypropylene (X) and impact copolymer ( Y) is set to 100 wt%).
When the content of polypropylene (X) having a long chain branch is too small, the open cell ratio of the foamed molded product is increased, or drawdown is deteriorated during thermoforming, which is not preferable. Conversely, when the content of polypropylene (X) is too large, the spreadability is lowered and the appearance of the sheet or film is deteriorated, or the extrusion amount is lowered and the productivity is deteriorated. The content of the polypropylene (X) and the impact copolymer (Y) can be adjusted to a desired content by adjusting the blend amount ratio when making the resin composition.

V-3. Characteristic (Z-i): MFR
The polypropylene resin composition of the present invention has an MFR of 0.1 to 20 g / 10 min. When a more preferable range is exemplified, the MFR is more preferably 1 to 15 g / 10 minutes, further preferably 2 to 10 g / 10 minutes, and most preferably 3 to 8 g / 10 minutes. When the MFR is lower than this range, the spreadability is lowered and the appearance of the sheet or film is deteriorated, or the extrusion amount is lowered and the productivity is deteriorated. On the other hand, if the MFR is higher than this range, the open cell ratio of the foamed molded product increases, the size of the bubbles becomes non-uniform, or the drawdown becomes worse during thermoforming. It is not preferable.
There are several ways to adjust the MFR within the above range. For example, the MFR of the polypropylene resin composition can be adjusted by adjusting the MFR of polypropylene (X) or impact copolymer (Y). Moreover, when MFR of polypropylene (X) and impact copolymer (Y) differs, MFR of a polypropylene resin composition can be adjusted also by changing the compounding quantity of both. For example, when the MFR of polypropylene (X) is higher than the MFR of impact copolymer (Y), increasing the blending amount of polypropylene (X) increases the MFR of the polypropylene resin composition.

V-4. Characteristic (Z-ii): Melt tension (MT)
The polypropylene resin composition of the present invention must have a melt tension (MT) measured at 230 ° C. of 1 to 7 g. When a more preferable range is exemplified, MT is more preferably 1.5 to 6 g, and most preferably 2 to 5 g. Here, MT of a polypropylene resin composition is a value obtained using the same measuring method as the melt tension (MT) of the characteristic (X-ii) of polypropylene (X). When MT is lower than the above range, the formation and growth of cells at the time of foaming are hindered, and the open cell ratio is increased, and the cell size is not uniform. On the other hand, when MT is higher than the above range, the spreadability is lowered, the appearance of the sheet or film is deteriorated, or the extrusion amount is lowered and the productivity is deteriorated.
There are several ways to adjust MT within the above range. For example, it can be adjusted by changing the MT of polypropylene (X) or by changing the blending amount of polypropylene (X) and impact copolymer (Y). Generally, when the content of polypropylene (X) is increased, the MT of the resin composition can be increased.

V-5. Propylene (co) polymer (H)
In particular, in fields where high melt tension is required, such as foam molding, it is required to use a resin composition having a high melt tension by further diluting with another resin from the viewpoint of achieving both physical properties and economic efficiency of the product. There are many cases.
In the polypropylene resin composition (Z) in the present invention, the constituent components, polypropylene (X) and impact copolymer (Y), each play a role of improving the foaming performance, and dilution with a resin that inhibits them. Will inhibit the effects of the present invention.
Therefore, it is preferable to use other resins for dilution as long as the effects of the present invention are not significantly impaired. In the polypropylene resin composition (Z) of the present invention, the polypropylene (X) and the impact copolymer (Y) are organically influenced to express a high effect on foaming performance. Even if diluted, a high effect is easily maintained.

In the present invention, a preferable resin used for dilution for improving economic efficiency while maintaining foaming performance is at least selected from the group consisting of a propylene homopolymer, or ethylene and an α-olefin having 4 to 10 carbon atoms. When the propylene (co) polymer (H) is a copolymer of one kind of olefin and propylene and the propylene (co) polymer (H) is a copolymer, ethylene in the propylene (co) polymer (H) and α- A propylene (co) polymer (H) having an olefin content of more than 0 and 3 wt% or less is preferred.
If the propylene (co) polymer (H) having the same performance as the propylene (co) polymer (YH) contained in the impact copolymer (Y) which is a constituent element of the present invention is used as a diluent, The content of polypropylene (X) in the diluted resin composition (Z ′) and the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is within the range of the resin composition (Z) of the present invention. This is based on the fact that the foaming characteristics are not deteriorated.
On the other hand, when other impact copolymers or polyethylene resins that do not satisfy the requirements of the impact copolymer (Y) according to the present invention are used as the diluent, they are propylene-ethylene copolymers (YC) in the impact copolymer (Y). ) And the effect of the present invention may be significantly inhibited, so care should be taken when selecting the diluent.
Whether or not the effect of the present invention is remarkably hindered is, for example, whether or not the open cell ratio shows a value about three times that when the diluent is used and when the diluent is not used. Can be.

  The blending amount of the propylene (co) polymer (H) is preferably 0.1 to 1000 parts by weight, more preferably 1 to 500 parts by weight, still more preferably 100 parts by weight of the polypropylene resin composition (Z). 10 to 300 parts by weight. The content of polypropylene (X) in the diluted resin composition (Z ′) and the propylene-ethylene copolymer (YC) in the impact copolymer (Y) can be maintained within the prescribed range of the resin composition (Z). The range is preferable, and the proportion of YC in the polypropylene resin composition (Z ′) is preferably 0.01 to 47.5 wt%, more preferably 1 to 36 wt% with respect to the total amount of X, Y and H Further, it is preferable to determine the blending amount of the propylene (co) polymer (H) so as to be 4 to 25.5 wt%.

V-6. Additives Various additives can be blended as optional components in the polypropylene resin composition (Z, Z ′) of the present invention. Specifically, antioxidants, ultraviolet absorbers, light stabilizers, metal deactivators, stabilizers, neutralizers, lubricants, antistatic agents, antifogging agents, which are conventionally used as polyolefin resin compounding agents, Various additives such as a nucleating agent, a peroxide, a filler, an antibacterial and antifungal agent, and a fluorescent brightening agent can be added as long as the effects of the present invention are not impaired. The amount of these additives is generally 0.0001 to 3 wt%, preferably 0.001 to 1 wt% in 100 wt% of the resin composition.

First, the antioxidant will be described.
Oxidative degradation of polyolefin is a radical chain reaction via peroxide radicals and hydroperoxide compounds generated by the action of heat, light, mechanical force, metal ions, etc. and oxygen, and is generally called auto-oxidation. . Antioxidants are used to suppress this auto-oxidation, and there are three types of phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants depending on where they act in the chain reaction. It is common to be separated.
A phenolic antioxidant is a radical scavenger, and since radicals generated by reaction with peroxide radicals and the like are relatively stable, the radical concentration in the system can be lowered. In general, a substituted phenol compound, particularly a substituted phenol compound having a bulky substituent at the ortho position is used.

Hereinafter, typical compounds are exemplified as the phenolic antioxidant.
In the monophenol type compound, 2,6-di-t-butyl-4-methylphenol (common name: BHT), tocopherol (vitamin E), n-octadecyl-3- (4′-hydroxy-3 ′, 5 ′) -Di-t-butylphenyl) propionate (trade name: Irganox 1076, Sumilizer BP-76) can be exemplified.
Among the bisphenol type compounds, 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (trade name: Sumilizer MDP-S), 1,1-bis (2′-methyl-4′-hydroxy-5) '-T-Butylphenyl) butane (trade name: Sumilizer BBM-S, Adekastab AO-40), 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) Propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (trade names: Smither GA-80, Adeka Stab AO-80) can be exemplified.
Among the triphenol type compounds, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (trade name: ADK STAB AO-30), 1,3,5-trimethyl-2 , 4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene (trade name: Irganox 1330, Adeka Stab AO-330), Tris- (3,5-di-t-butyl-4- Hydroxybenzyl) -isocyanurate (trade name: Irganox 3114, Adeka Stab AO-20), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (trade name: Sumilyzer) BP-179, Cyanox 1790), tris- (3,5-di-tert-butyl-4-hydroxyphenyl) -isocyanu Over door (trade name: Keminokkusu 314) can be exemplified.
Examples of the tetraphenol type compound include tetrakis {methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate} methane (trade name: Irganox 1010).

  The phosphorus-based antioxidant has an action of reducing the hydroperoxide compound and is also called a hydroperoxide decomposing agent. Although it has an antioxidant effect by itself, when used in combination with the above-mentioned phenolic antioxidant, a synergistic effect is generated and the antioxidant effect is further enhanced. Therefore, both are usually used in combination. This synergistic effect occurs because the phenolic antioxidant regenerates by reducing the phenoxy radical species generated by the reaction between the phenolic antioxidant and the radical species involved in autoxidation by the phosphorus antioxidant. It is believed that.

Hereinafter, typical compounds are exemplified as the phosphorus-based antioxidant.
Among the phosphite type compounds, tris (2,4-di-t-butylphenyl) phosphite (trade name: Irgafos 168, Sumilizer P-16, Adeka Stab 2112), trisnonylphenyl phosphite (trade name: Sumilyzer TNP, Adeka Stab) 1178), tris (mixed, mono-dinonylphenyl phosphite) (trade name: ADK STAB 329K), tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite (common name: P-EPQ) and cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl phosphite) (trade name: ADK STAB PEP-36).

Sulfur-based antioxidants, like phosphorus-based antioxidants, have the effect of reducing hydroperoxide compounds and are also called hydroperoxide decomposing agents. This is also said to have a synergistic effect when used in combination with a phenolic antioxidant, as is the case with phosphorus antioxidants.
Hereinafter, typical compounds are exemplified as the sulfur-based antioxidant.
In the sulfide type compound, dilauryl-3,3′-thio-dipropionate (common name: DLTDP), di-myristyl-3,3′-thio-dipropionate (common name: DMTDP), distearyl-3,3′-thio- Examples thereof include dipropionate (common name: DSTDP), pentaerythritol-tetrakis- (3-laurylthio-propionate) (trade name: Sumilizer TP-D, ADK STAB AO-412S).

Next, the ultraviolet absorber and the light stabilizer will be described.
Additives for suppressing photodegradation are ultraviolet absorbers and light stabilizers. When polypropylene is exposed to ultraviolet rays, radicals are generated and auto-oxidation occurs. The ultraviolet absorber has an action of suppressing generation of radicals by absorbing ultraviolet rays, and the light stabilizer has an action of capturing and inactivating radicals generated by ultraviolet rays.
The ultraviolet absorber is a compound having an absorption band in the ultraviolet region, and triazole, benzophenone, salicylate, cyanoacrylate, nickel chelate, inorganic fine particle, and the like are known. Of these, the triazole type is most widely used.
Hereinafter, typical compounds are exemplified as the ultraviolet absorber.
Among triazole-based compounds, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole (trade name: Sumisorb 200, TinuvinP), 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole (Trade names: Sumisorb 340, Tinuvin 399), 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole (trade names: Sumisorb 320, Tinuvin 320), 2- (2′-hydroxy) -3 ′, 5′-di-t-amylphenyl) benzotriazole (trade names: Sumisorb 350, Tinuvin 328), 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5 Chlorobenzotriazole (trade name: Sumisorb 300, Tinuvin 326) Yes.
Examples of benzophenone-based compounds include 2-hydroxy-4-methoxybenzophenone (trade name: Sumisorb 110) and 2-hydroxy-4-n-octoxybenzophenone (trade name: Sumisorb 130).
Examples of salicylate compounds include 4-t-butylphenyl salicylate (trade name: Seesorb 202). Examples of cyanoacrylate compounds include ethyl (3,3-diphenyl) cyanoacrylate (trade name: Seesorb 501). Examples of the nickel chelate compound include nickel dibutyldithiocarbamate (trade name: Antigen NBC). Examples of inorganic fine particle compounds include TiO ₂ , ZnO ₂ , and CeO ₂ .

The light stabilizer is generally a hindered amine compound and is called HALS. HALS has a 2,2,6,6-tetramethylpiperidine skeleton and cannot absorb ultraviolet rays, but suppresses photodegradation by various functions. The main functions are said to be three of: scavenging radicals, decomposing hydroxy peroxide compounds, and capturing heavy metals that accelerate the decomposition of hydroxy peroxides.
Hereinafter, representative compounds will be exemplified as HALS.
In the sebacate type compound, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (trade name: ADK STAB LA-77, Tinuvin 770), bis (1,2,2,6,6-pentamethyl- 4-piperidyl) sebacate (trade name: Tinuvin 765) can be exemplified.
Among the butanetetracarboxylate type compounds, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (trade name: ADK STAB LA-57), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (trade name: ADK STAB LA-52), 1,2,3,4-butanetetra Condensation product of carboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol (trade name: Adeka Stab LA-67), 1,2,3,4-butanetetracarboxylic acid and 1, A condensate of 2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol (trade name: Adeka Stab LA-62) can be exemplified. .
Examples of the succinic polyester type compound include a condensation polymer of succinic acid and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine.
In the triazine type compound, N, N′-bis (3-aminopropyl) ethylenediamine · 2,4-bis {N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino } -6-Chloro-1,3,5-triazine condensate (trade name: Chimassorb 199), poly {6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2 , 4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino} (trade name: Chimassorb 944) ), Poly (6-morpholino-s-triazine-2,4-diyl) {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-teto Lamethyl-4-piperidyl) imino} (trade name: Chimasorb 3346).

Some other additives are also exemplified.
A lubricant is an additive used to improve moldability and fluidity, and has the effect of reducing the frictional force between polymer molecules and the frictional force between the polymer and the inner wall of the molding machine in a molding machine or extruder. . Compounds used as lubricants include hydrocarbon compounds such as paraffin and wax, alcohols such as stearyl alcohol and propylene glycol, higher fatty acid esters such as n-butyl stearate, higher fatty acid amides such as oleic acid amide and stearic acid amide, stear Examples include higher fatty acid salts such as calcium phosphate, partial esters of polyhydric alcohols such as stearic acid monoglyceride, and silicone oil.
Among these, specific examples of the higher fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, and behenic acid amide. The fatty acid amide compound may have a substituent on the alkyl chain or N. Examples of the fatty acid amide compound having a substituent include hydroxy stearic acid amide, N-oleyl palmitic acid amide, N-stearyl oleic acid amide, N-stearyl erucic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, Can be mentioned.

The stabilizer is an additive for polyvinyl chloride (PVC) in the first place, and is used for the purpose of preventing degradation of hydrochloric acid (HCl) from PVC. Some of the various stabilizers also have a function as a neutralizing agent, and thus may be used as an additive for polyolefins.
A neutralizing agent is a compound used to neutralize chlorine components derived from Ziegler catalysts used in the production of polyolefins. As the neutralizing agent, a carboxylate having a neutralizing ability is often used, but an inorganic compound having a chlorine ion capturing ability can also be used. Both are compounds used as stabilizers. Basically, when using a metallocene catalyst that does not contain a chlorine atom, it is an additive that is not necessary in nature. It is often done.
Hereinafter, typical compounds are exemplified as the neutralizing agent.
Examples of the carboxylate type compound include calcium stearate and zinc stearate. Examples of inorganic compounds include hydrotalcite and inclusions of aluminum hydroxide and lithium carbonate (trade name: Mizukarak).

VI. Extrusion foam molding, polypropylene foam sheet, thermoformed body The polypropylene resin composition of the present invention can be used for extrusion molding, injection molding, calendar molding, press molding, etc. Since the tension is moderate and the spreadability is good, it is particularly suitable for various types of extrusion foaming. The type of extrusion foaming used is not particularly limited.
Typical extrusion foam molding includes foam molding by foam sheet molding, foam film molding, foam blow molding, and the like. In the case of foam sheet molding, a known combination of an extruder and a die can be used.
The extruder may be uniaxial or biaxial. The die may be a T die or a circular shape (circular). The same applies to foam film formation. In the case of foam film formation, stretching may be further performed. As the stretching method, a known method can be used without limitation. For example, a tubular method, a tenter type stretching method, a roll stretching method, a pantograph type batch stretching method, and the like can be exemplified. Also in the case of foam blow molding, a known method may be used. Specific examples include a direct blow molding machine and an accumulative blow molding machine.
Hereinafter, the details will be described in order.

VI-1. Foaming agent When performing extrusion foaming using the polypropylene resin composition of the present invention, it is necessary to use a foaming agent. At this time, the type of the foaming agent is not particularly limited, and a known foaming agent used for plastics, rubber, and the like can be used. The type of foaming agent is not particularly limited, and any type such as a physical foaming agent, a degradable foaming agent (chemical foaming agent), a microcapsule containing a thermal expansion agent, or the like may be used.

Specific examples of physical blowing agents include aliphatic hydrocarbons such as propane, butane, pentane and hexane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, and dichloromethane. Difluoromethane, chloromethane, dichloromethane, chloroethane, dichlorotrifluoroethane, dichlorofluoroethane, chlorodifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, trichlorotrifluoroethane, dichlorotetrafluoroethane Illustrative of halogenated hydrocarbons such as chloropentafluoroethane and perfluorocyclobutane, inorganic gases such as water, carbon dioxide and nitrogen Rukoto can. These compounds may be used alone or in combination with a plurality of compounds.
Among these, aliphatic hydrocarbons such as propane, butane, and pentane and carbon dioxide are preferable because they are inexpensive and have high solubility in the polypropylene resin (X). In particular, when carbon dioxide gas is used, supercritical conditions of 7.4 MPa or more and 31 ° C. or more are more preferable because the state of diffusion and solubility in the polymer is excellent.

When a physical foaming agent is used, a bubble regulator can be used as necessary. Examples of the air conditioner 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 dinitrosopentanemethylenetetramine and N, N'-dimethyl-N, N'-dinitrosotephthalamide, benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p, p'-oxybisbenzenesulfonyl semicarbazide, p- Degradable foaming agents such as toluenesulfonyl semicarbazide, trihydrazinotriazine, barium azodicarboxylate, inorganic powders such as talc and silica, acid salts such as polyvalent carboxylic acids, reaction of polyvalent carboxylic acids with sodium carbonate or sodium bicarbonate Examples of mixtures It is possible. These bubble regulators may be used alone or in combination.
When using the foam regulator, the blending amount of the foam regulator is in a range of 0.01 to 5 parts by weight with respect to a total of 100 parts by weight of polypropylene (X) and impact copolymer (Y). It is preferable to do.

Specific examples of degradable foaming agents (chemical foaming agents) include a mixture of sodium bicarbonate and an organic acid such as citric acid, an azo foaming agent such as azodicarbonamide and barium azodicarboxylate, and N, N′-dinitrosopentamethylene. Nitroso blowing agents such as tetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, sulfohydrazide blowing agents such as p, p′-oxybisbenzenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, tri And hydrazinotriazine.
The blending amount of the foaming agent is preferably in the range of 0.05 to 6.0 parts by weight, more preferably 0.05 to 3.3 parts per 100 parts by weight of the total of polypropylene (X) and impact copolymer (Y). The amount is 0 part by weight, more preferably 0.5 to 2.5 parts by weight, and particularly preferably 1.0 to 2.0 parts by weight.

VI-2. Polypropylene foam sheet The polypropylene foam sheet of the present invention is produced using the polypropylene resin composition (Z) or the polypropylene resin composition (Z ′). In the present invention, the shape and molding method of the polypropylene foam sheet are not limited. The thickness of the foam sheet is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm to 5 mm.
Polypropylene foam sheets are secondarily processed by thermoforming, and are widely used in industry, mainly in various containers. Polypropylene-based foam sheets are widely used in various applications with the advantage of being lightweight.
Here, since the polypropylene foam sheet contains many bubbles (cells) in the sheet, if the cells are rough or irregular, they appear on the surface of the sheet, which deteriorates the surface appearance and has a commercial value. It will decline. Further, when thermoforming is performed, it is necessary to heat the mold sufficiently to transfer the mold, but in the foam sheet, the cell also expands when heated. As a result, if the foam cell is rough, the surface tends to deteriorate, and if the foam cell is not uniform, the sheet is torn during heating.
In order to solve these problems, it is thought that it is necessary to form a foam cell having a high closed cell ratio, a dense and uniform size, but the polypropylene resin composition for extrusion foam molding in the present invention should be used. Thus, a sheet having excellent appearance and high thermoforming suitability can be obtained as a foamed sheet.

VI-4. Polypropylene-based multilayer foamed sheet When producing a polypropylene-based foamed sheet, a multilayer foamed sheet may be used.
Specifically, a foam layer using the polypropylene resin composition for extrusion foam molding of the present invention and a non-foam layer made of a thermoplastic resin composition may be co-extruded. At this time, a known co-extrusion method using a feed block or a multi-die using a plurality of extruders can be used.
The non-foamed layer used in the polypropylene-based multilayer foamed sheet using the polypropylene resin composition for extrusion foam molding of the present invention for the foamed layer may be provided on any surface of the foamed layer, and the foamed layer is not foamed. It is also possible to adopt a configuration (sandwich structure) that exists between the layers.

The thickness of the polypropylene-based multilayer foamed sheet is not particularly limited, but is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm-5 mm.
Moreover, the thickness of the non-foamed layer in the polypropylene-based multilayer foamed sheet is 1 to 50% of the total thickness of the obtained polypropylene-based multilayer foamed sheet, more preferably 5 to 20 so as not to hinder the growth of bubbles in the foamed layer. It is desirable to form so that it may become%.

  The polypropylene-based multilayer foam sheet provided with a non-foamed layer is excellent in strength, and is provided with a non-foamed layer at least on the outside of the foamed layer, so that the surface smoothness and appearance are also excellent. Become. Furthermore, by using a functional thermoplastic resin for the non-foamed layer, it is possible to easily combine the polypropylene-based multilayer foam sheet with additional functions such as antibacterial properties, soft feeling, and scratch resistance. preferable.

As the thermoplastic resin constituting the thermoplastic resin composition used for the non-foamed layer, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and propylene-α can be used as long as the effects of the present invention are not impaired. -Olefin copolymers, polyolefins such as poly-4-methyl-pentene-1, olefinic elastomers such as ethylene-propylene elastomer, or other monomers copolymerizable therewith, such as vinyl acetate, vinyl chloride, (meta ) Copolymers and mixtures such as acrylic acid and (meth) acrylic acid esters can be selected.
Among these, polypropylene and propylene-α-olefin copolymers are preferable from the viewpoints of recyclability, adhesiveness, heat resistance, oil resistance, rigidity, and the like. The propylene-α-olefin copolymer includes an impact copolymer obtained by multi-stage polymerization of a propylene (co) polymer and an ethylene-propylene random copolymer using a plurality or a single tank polymerization tank.
Among these, the impact copolymer is more preferable because it has an excellent balance between rigidity and impact resistance, and the impact copolymer (Y ′) that satisfies the requirements to be satisfied by the impact copolymer (Y) (where (Y ′) is (Y) When the surface layer is used, the obtained sheet has a good surface appearance, and the cell at the time of thermoforming is used. Since it has the characteristic of high retention, it is most preferable. At this time, the content of the impact copolymer (Y ′) in the polypropylene resin composition used for the surface layer is preferably 0.1 to 100% by weight.

In particular, when used as a thermoformed product, the rigidity of the molded product is very important. To improve this, a non-foamed layer is provided on the surface layer, and an inorganic filler is provided on the non-foamed layer. It is preferable to mix. As a thermoplastic resin composition used for the non-foamed layer, it is desirable to blend 50 parts by weight or less of an inorganic filler with respect to 100 parts by weight of the thermoplastic resin. If the amount exceeds 50 parts by weight, the surface of the sheet is liable to be damaged due to the occurrence of scraping at the die outlet.
Examples of the inorganic filler include talc, calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate and the like.

VI-3. Thermoformability Although the polypropylene foam sheet and the polypropylene multilayer foam sheet in the present invention have high thermoformability, they can be evaluated by performing a sag test. The sag test is a test method in which a sheet is heated with a heater as in thermoforming, and the behavior of the sheet at that time is observed. The behavior of the sheet in the sag test is as follows.
First, when the sheet is heated, it softens and expands, and the sheet once hangs down. During this time, crystal melting is not yet sufficient, and there is insufficient spread during thermoforming, and the mold shape cannot be transferred sufficiently. When heating progresses and crystal melting is sufficient, the sheet once hung down contracts due to relaxation of residual stress during sheet forming, and stretches back to the position at the time of heating. At this time, the crystal is sufficiently melted and the residual stress is released, so that a molded body in which the mold is sufficiently transferred can be obtained at the time of thermoforming. As the heating further proceeds, the viscosity decreases as the sheet temperature rises and begins to sag due to its own weight or cell expansion, and eventually begins to open holes. If the hole is opened, it is of course impossible to obtain a molded body by thermoforming, and even if the hole is not opened, if the sag is large, the mold contacts with the mold and cannot be obtained.
In the above behavior, the range in which thermoforming is possible is within the range from time T1 when the sheet is stretched back to time T2 until the hole is opened. The wider the time width, the wider the moldable range. T2-T1 can be obtained and used for the evaluation of thermoformability. At this time, in this time range, the smaller the sag, the easier it is to perform thermoforming, and the larger molded body can be molded. Therefore, the sag amount D (T2) at T2 is divided by (T2-T1). Thus, it is defined as an average sag velocity VD [mm / s] in the moldable range, and this can also be used for evaluation of thermoformability.

As for the state of the foamed cell, a state where the size of the cell is small and dense, the size is uniform, and high independence is preferable. Specifically, the average bubble diameter is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 300 μm or less. When the average cell diameter greatly exceeds 500 μm, when a polypropylene foam sheet or the sheet is thermoformed, an appearance defect such as perforation occurs in the thermoformed body, which is not preferable. In addition, let an average bubble diameter be the value calculated | required using the optical microscope by the method as described in an Example.
The cell independence can be determined by the open cell ratio. The open cell ratio is preferably 30% or less, more preferably 20% or less, and still more preferably 15% or less. If the open cell ratio exceeds 30%, expansion of the foamed cells in the foamed sheet does not occur during thermoforming, and the thickness of the thermoformed body is reduced, which is not preferable. Moreover, since it leads also to the fall of the heat insulation performance of a thermoforming body, it is not preferable.
In addition, let open-cell rate be the value calculated | required using the air pycnometer (made by Tokyo Science Co., Ltd.) by the method as described in an Example.

VI-5. Thermoformed body The thermoformed body of the present invention is obtained by thermoforming the above-mentioned polypropylene foam sheet or polypropylene multilayer foam sheet.
The thermoforming method is not particularly limited. For example, plug molding, matched molding, straight molding, drape molding, plug assist molding, plug assist reverse draw molding, air slip molding, snapback molding, reverse draw. Examples thereof include molding, free drawing molding, plug and ridge molding, and ridge molding.

VI-6. Applications The polypropylene foam sheet and thermoformed article of the present invention have uniform and fine foam cells and are excellent in appearance, thermoformability, impact resistance, light weight, rigidity, heat resistance, heat insulation, oil resistance, etc. Therefore, it can be suitably used for food containers such as trays, dishes and cups, vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery, and building materials.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

1. Measurement method of various physical properties (i) MFR
Measured in accordance with JIS K7210: 1999, Method A, Condition M (230 ° C., 2.16 kg load). The unit is g / 10 minutes.
(Ii) Melt tension (MT)
It measured on the following conditions using the Toyo Seiki Seisakusho Capillograph.
・ Capillary: Diameter 2.0mm, length 40mm
・ Cylinder diameter: 9.55mm
・ Cylinder extrusion speed: 20 mm / min ・ Pickup speed: 4.0 m / min ・ Temperature: 230 ° C.
When the MT is extremely high, the resin may break at a take-up speed of 4.0 m / min. In such a case, the take-up speed is lowered and the tension at the highest speed at which the take-up can be taken is MT. And The unit is gram.

(Iii) 25 ° C. paraxylene soluble component amount (CXS)
CXS values were obtained using the following method.
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml BHT) at 130 ° C. to make a solution, and then left at 25 ° C. for 12 hours. Thereafter, the precipitated polymer is separated by filtration, p-xylene is evaporated from the filtrate, and further dried under reduced pressure at 100 ° C. for 12 hours to recover a 25 ° C. xylene-soluble component. The ratio [wt%] of the weight of the recovered component to the charged sample weight is defined as CXS.
(Iv) Branch index g ^′
Using a GPC equipped with a differential refractometer (RI), a viscosity detector (Viscometer), and a light scattering detector (MALLS) as detectors, the branching index g ^′ when the absolute molecular weight Mabs was 1 million was determined. The specific measurement method, analysis method, and calculation method are as described above.
(V) Degree of strain hardening (λmax)
The elongational viscosity was measured using Ales manufactured by Rheometrics, and the strain hardening degree (λmax) was obtained from the result. The specific measurement method and calculation method are as described above.

(Vi) Isotactic triad fraction (mm fraction), presence / absence of long-chain branching As described above, using JSX Corporation GSX-400, FT-NMR, paragraph [0025] of JP-A-2009-275207 ] To [0065]. The unit of mm fraction is%.
(Vii) Ethylene content in propylene-ethylene copolymer (YC) Using the CXS component of the impact copolymer (Y) obtained by the method described in (iii) above, the ethylene content was determined by ¹³ C-NMR. . The measurement conditions for ¹³ C-NMR are as follows.
Model: GSX-400 manufactured by JEOL Ltd.
Solvent: o-dichlorobenzene + heavy benzene (4: 1 (volume ratio))
Concentration: 100 mg / mL
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more The method for analyzing the obtained spectrum is as described above.

(Vii) Intrinsic viscosity of propylene-ethylene copolymer (YC) Intrinsic viscosity was measured using the CXS component of the impact copolymer (Y) obtained by the method described in (iii) above. The intrinsic viscosity was measured using an Ubbelohde capillary viscometer under the conditions of a temperature of 135 ° C. and a decalin solvent.
(Viii) Content of propylene-ethylene copolymer (YC) in impact copolymer (Y) The CXS value (wt%) of impact copolymer (Y) obtained by the method described in (iii) above is calculated as impact copolymer (Y). The content (wt%) of the propylene-ethylene copolymer (YC) in Y).

2. Materials used (1) Polypropylene (X)
Polypropylenes (X1) to (Xc7) obtained in the following Production Examples X1 to Xc7 were used as polypropylene (X).

[Production Example X1: Production of Polypropylene (X1)]
<Synthesis of catalyst component [A-1]>
Dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl}] hafnium was synthesized by the following procedure.
(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 ( 0.28 mol) and 100 ml of water were added, 13 g (67 mmol) of 4-bromoindene and 5 g (4 mmol) of tetrakistriphenylphosphinopalladium were added in this order, and the mixture was heated at 80 ° C. for 6 hours.
After allowing to cool, the reaction solution was poured into 500 ml of distilled water, transferred to a separatory funnel, and extracted with diisopropyl ether. The ether layer was 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 15.4 g (yield 99%) of 4- (4-i-propylphenyl) indene as a colorless liquid.

(Ii) Synthesis of 2-bromo-4- (4-i-propylphenyl) indene In a 500 ml glass reaction vessel, 15.4 g (67 mmol) of 4- (4-i-propylphenyl) indene, 7.2 ml of distilled water DMSO (200 ml) was added, and N-bromosuccinimide (17 g, 93 mmol) was gradually added thereto. The mixture was stirred at room temperature for 2 hours, poured into 500 ml of ice water, and extracted three times with 100 ml of toluene. The toluene layer was washed with saturated brine, 2 g (11 mmol) of p-toluenesulfonic acid was added, and the mixture was heated to reflux for 3 hours while removing moisture. 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 with 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 glass reaction vessel, 6.7 g (82 ml mol) of 2-methylfuran and 100 ml of DME were added. The solution was cooled to -70 ° C in a dry ice-methanol bath. To this was added dropwise 51 ml (81 mmol) of a 1.59 mol / L n-butyllithium-n-hexane solution, and the mixture was stirred for 3 hours. The solution was cooled to −70 ° C., and a solution of 20 ml (87 mmol) of triisopropyl borate and 50 ml of DME was added dropwise thereto. After dropping, the mixture was stirred overnight while gradually returning to room temperature.
The reaction solution was hydrolyzed by adding 50 ml of distilled water, and then a solution of 223 g of potassium carbonate and 100 ml of water and 19.8 gg (63 mmol) of 2-bromo-4- (4-i-propylphenyl) indene were added in that order at 80 ° C. The mixture was heated and reacted for 3 hours while removing low-boiling components.
After allowing to cool, the reaction solution was poured into 300 ml of distilled water, transferred to a separatory 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 with a silica gel column to obtain 19.6 g of 2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indene as a colorless liquid ( Yield 99%).

(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. To this, 17 ml (28 mmol) of a 1.66 mol / L n-butyllithium-n-hexane solution was dropped, 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 solution, transferred to a separatory funnel and washed with brine until neutral, and sodium sulfate was added to dry the reaction solution. Sodium sulfate was filtered off, the solvent was distilled off under reduced pressure, and the residue was purified with a silica gel column. 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, 8.6 g (13 mmol) of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane and 300 ml of diethyl ether were added, and -70 ° C. in a dry ice-methanol bath. Until cooled. To this, 15 ml (25 mmol) of a 1.66 mol / L n-butyllithium-n-hexane solution was added dropwise and stirred for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, 400 ml of toluene and 40 ml of diethyl ether were added, and the solution was cooled to −70 ° C. in a dry ice-methanol bath. Thereto was added 4.0 g (13 mmol) of hafnium tetrachloride. Thereafter, the mixture was stirred overnight while gradually returning to room temperature.
The solvent was distilled off under reduced pressure, recrystallized with dichloromethane-hexane, and dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl]. }] 7.6 g (yield 65%) of hafnium racemate as yellow crystals was obtained.
The identified value by ^{1 H-NMR} of the obtained racemates are described below.
¹ H-NMR (C6D6) identification results Racemate: δ0.95 (s, 6H), δ1.10 (d, 12H), δ2.08 (s, 6H), δ2.67 (m, 2H), δ5. 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 ), Δ 7.30 (d, 2H), δ 7.83 (d, 4H).

<Synthesis of catalyst component [A-2]>
Based on the method described in Example 1 of JP-A-11-240909, rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium Was synthesized.

<Synthesis of catalyst component B>
(I) Chemical treatment of ion-exchange layered silicate In a separable flask, 96% sulfuric acid (668 g) was added to 2,264 g of distilled water, and then montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL: average particle size 19 μm) as a layered silicate ) 400 g was added. The slurry was heated at 90 ° C. for 210 minutes. When this reaction slurry was added to 4,000 g of distilled water and filtered, 810 g of a cake-like solid was obtained.
Next, 432 g of lithium sulfate and 1,924 g of distilled water were added to the separable flask to make a lithium sulfate aqueous solution, and the entire amount of the cake-like solid was charged. The slurry was reacted at room temperature for 120 minutes. 4 L of distilled water was added to this slurry, followed by filtration, and further washing with distilled water to pH 5-6, followed by filtration to obtain 760 g of a cake-like solid.
The obtained solid was preliminarily dried overnight at 100 ° C. under a nitrogen stream, and then coarse particles of 53 μm or more were removed, followed by drying 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 wt%, Si: 38.30 wt%, Mg: 0.98 wt%, Fe: 1.88 wt%, Li: 0.16 wt%, Al / Si = 0.175 [mol / mol].

<Preparation of prepolymerization catalyst M1>
(I) Catalyst preparation and prepolymerization In a three-necked flask (volume: 1 L), 20.0 g of the chemically treated smectite obtained by the synthesis of the above catalyst component B was added, and heptane (132 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 68.0 mL of a 143 mg / mL concentration heptane solution) was added and stirred for 1 hour, and then washed with heptane until the residual liquid ratio became 1/100, so that the total volume became 100 mL. Added heptane.
In another flask (volume: 200 mL), rac-dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) obtained by synthesis of the catalyst component [A-1] is used. ) -4- (4-i-propylphenyl) indenyl}] hafnium (180 μmol) was dissolved in toluene (42 mL) (Solution 1), and in another flask (volume 200 mL), the above catalyst component [A -2] dissolved in rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium (120 μmol) in toluene (18 mL). (Solution 2).
Triisobutylaluminum (0.84 mmol: 1.2 mL of a heptane solution with 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. Thereafter, triisobutylaluminum (0.36 mmol: 0.50 mL of a heptane solution having a concentration of 143 mg / mL) was added, and then the above solution 2 was added and stirred at room temperature for 1 hour.
Thereafter, 338 mL of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed while maintaining the temperature at 40 ° C. for 4 hours. Thereafter, propylene feed was stopped and residual polymerization was carried out for 1 hour. After removing the supernatant of the resulting 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.
This solid was dried under reduced pressure for 1 hour to obtain 60.0 g of a dry prepolymerized catalyst. The prepolymerization magnification (a value obtained by dividing the amount of the prepolymerized polymer by the amount of the solid catalyst) was 2.00 g / g-catalyst.
Hereinafter, this is referred to as “preliminary polymerization catalyst M1”.

<Polymerization>
After sufficiently replacing the inside of the stirring autoclave with an internal volume of 200 liters with propylene, 40 kg of purified liquefied propylene was introduced. To this was added 10 L of hydrogen (as a standard volume) and 470 ml (0.12 mol) of a triisobutylaluminum-n-heptane solution, and the internal temperature was adjusted to 30 ° C. Next, 2.0 g (by weight excluding the prepolymerized polymer) of the prepolymerized catalyst M1 was injected with argon, and the temperature was raised until the internal temperature reached 70 ° C. Two hours after the internal temperature reached 70 ° C., 100 ml of ethanol was injected under pressure, unreacted propylene was purged, and the inside of the autoclave was purged with nitrogen to terminate the polymerization. Thereafter, the obtained polymer was dried for 1 hour under a nitrogen stream at 90 ° C. The yield of polypropylene was 19.0 kg, and the catalytic activity was 9.5 kg-PP / g-catalyst.

<Granulation>
1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (trade name: Cyanox 1790, Nippon Cytec Industries) with respect to 100 parts by weight of the polypropylene obtained by the above polymerization. 0.05 part by weight, Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.) 0.10 part by weight, poly {6- (1 , 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {( 2,2,6,6-tetramethyl-4-piperidyl) imino} (trade name: Chimassorb 944, manufactured by BASF Japan Ltd.) 0.03 Part by weight and 0.09 part by weight of stearamide were mixed and sufficiently stirred, then melt-kneaded using a twin-screw extruder (Technobel KZW25TW-45MG-NH), the extruded strand was cut and pelleted To obtain polypropylene (X1).
The results of analyzing the obtained polypropylene (X1) are shown in Table 3. As a result of ¹³ C-NMR measurement, it was confirmed that long chain branching was present in this polypropylene (X1). In addition, the branching index g ^′ is 0.85 and a value smaller than 1 indicates that this polypropylene (X1) has a long chain branch.

[Production Example X2: Production of Polypropylene (X2)]
<Preparation of prepolymerization catalyst M2>
The prepolymerized catalyst M2 was prepared in the same manner as the preparation of the prepolymerized catalyst M1 of Production Example X1, except that the usage amounts of the catalyst components [A-1] and [A-2] were 210 and 90 μmol, respectively. . The yield of the dried prepolymerized catalyst was 58.0 g, and the prepolymerization ratio was 1.90 g / g-catalyst.
Hereinafter, this is referred to as “preliminary polymerization catalyst M2”.

<Polymerization>
Polymerization was performed in the same manner as in Production Example X1, except that the prepolymerization catalyst M2 was used instead of the prepolymerization catalyst M1, and the amount of hydrogen used was 9.5 L (as a standard volume). The yield of polypropylene was 18.4 kg, and the catalytic activity was 9.2 kg-PP / g-catalyst.

<Granulation>
Using the polypropylene obtained by the above polymerization, granulation was carried out in the same manner as in Production Example X1, to obtain polypropylene (X2).
The results of analyzing the obtained polypropylene (X2) are shown in Table 3.

[Production Example Xc3: Production of polypropylene (Xc3)]
Polypropylene (Xc3) was produced in the same manner as in Production Example X1 except that the amount of hydrogen used was 6.2 L (as a standard volume) during the polymerization (synthesis and production of prepolymerized catalyst). The grains are the same as in Production Example X1).
The results of analyzing the obtained polypropylene (Xc3) are shown in Table 3.

[Production Example Xc4: Production of polypropylene (Xc4)]
Polypropylene (Xc4) was produced in the same manner as in Production Example X2 except that the amount of hydrogen used was changed to 7.8 L (as a standard volume) during the polymerization (synthesis and production of prepolymerized catalyst). The grains are the same as in Production Example X2.)
The results of analyzing the obtained polypropylene (Xc4) are shown in Table 3.

[Production Examples X5, X6: Production of polypropylene (X5, X6)]
In the polymerization, polypropylene (X5, X6) was produced in the same manner as in Production Example X2, except that the amount of hydrogen used was 9.0, 10.5 L (as a standard state volume), respectively ( The synthesis and granulation of the prepolymerization catalyst are the same as in Production Example X2).
Table 3 shows the results of analyzing the obtained polypropylene (X5, X6).

[Production Example Xc7: Production of polypropylene (Xc7)]
Polypropylene (Xc7) was produced in the same manner as in Production Example X2 except that the amount of hydrogen used was 11.0 L (as a standard volume) during the polymerization (synthesis and production of prepolymerized catalyst). The grains are the same as in Production Example X2.)
The results of analyzing the obtained polypropylene (Xc7) are shown in Table 3.

(2) Impact copolymer (Y)
The impact copolymers (Y1) to (Y7) obtained in the following production examples Y1 to Y6 were used as the impact copolymers (Y). In the production examples of Y, Me is an abbreviation for methyl, Et is ethyl, Pr is propyl, and Bu is butyl.

[Production Example Y1: Production of Impact Copolymer (Y1)]
<Method for analyzing catalyst>
In analyzing the catalyst component, the solid catalyst, and the prepolymerized catalyst, the following methods were used.
・ Ti content (wt%)
The sample was accurately weighed, hydrolyzed, and measured using a colorimetric method. About the sample after prepolymerization, content was calculated using the weight remove | excluding 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. About the sample after prepolymerization, content was calculated using the weight remove | excluding prepolymerized polymer.

<Preparation of prepolymerization catalyst Z1>
(1) Preparation of solid component Z1 A 10 L autoclave equipped with a stirrer was sufficiently substituted with nitrogen, and 2 L of purified toluene was introduced. Here, 200 g of Mg (OEt) ₂ was added at room temperature, and 1 L of TiCl ₄ was slowly added thereto. The temperature was gradually raised to 90 ° C., and 50 ml of di-n-butyl phthalate was introduced. Thereafter, the temperature was raised to 110 ° C. to carry out a reaction for 3 hours. The reaction product was thoroughly washed with purified toluene. Subsequently, the refined toluene was introduce | transduced and the whole liquid quantity was adjusted to 2L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and the reaction was performed for 2 hours. The reaction product was thoroughly washed with purified toluene. Subsequently, the refined toluene was introduce | transduced and the whole liquid quantity was adjusted to 2L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and the reaction was performed for 2 hours. The reaction product was thoroughly washed with purified toluene. Further, using purified n-heptane, toluene was replaced with n-heptane to obtain a slurry of solid component Z1. A portion of this slurry was sampled and dried. As a result of analysis, the Ti content of the solid component Z1 was 2.7 wt%.

(2) Preparation of Solid Catalyst Z1 Next, a 20 L autoclave equipped with a stirring device was sufficiently substituted with nitrogen, and 100 g of the solid component Z1 slurry was introduced as a solid component. Purified n-heptane was introduced to adjust the solid component concentration to 25 g / L. 50 ml of SiCl ₄ was added and a reaction was performed at 90 ° C. for 1 hr. The reaction product was thoroughly washed with purified n-heptane.
Thereafter, 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 product was thoroughly washed with purified n-heptane to obtain a solid catalyst Z1.
A portion of the resulting slurry of solid catalyst Z1 was sampled and dried for analysis. The solid catalyst Z1 contained 1.2 wt% Ti and 8.9 wt% t-BuMeSi (OMe) ₂ .

(3) Prepolymerization Prepolymerization was performed by the following procedure using the solid catalyst Z1 obtained above.
Purified n-heptane was introduced into the slurry, and the solid catalyst concentration was adjusted 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.
Next, the gas phase was sufficiently replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum-dried to obtain a prepolymerized catalyst Z1.
This prepolymerized catalyst Z1 contained 2.5 g of polypropylene per 1 g of the solid catalyst. As a result of analysis, the portion of the prepolymerized catalyst Z1 excluding polypropylene contained 1.0 wt% Ti and 8.3 wt% t-BuMeSi (OMe) ₂ .

<Polymerization>
The polymerization was carried out using a two-vessel continuous gas phase polymerization reactor. The first polymerization tank for carrying out the first step of 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 source gas used was a sufficiently purified one.

(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 controlling 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 is supplied to the first polymerization tank at 4.0 g / h, and the preliminary polymerization catalyst Z1 is fed so that the production rate of the propylene polymer in the first polymerization tank is 17.5 kg / h. Propylene homopolymer was produced by continuously feeding. The powder (propylene polymer) produced in the first polymerization tank was continuously withdrawn so that the amount of powder retained in the polymerization tank was 40 kg, and was 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 the measurement of MFR, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (product) was added to the sample propylene polymer. Name: IRGANOX 1010, manufactured by BASF Japan Ltd., Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.), calcium stearate, respectively, in appropriate amounts (about 500 wtppm) Measurement was performed after addition and mixing.

(Second step: production of propylene-ethylene copolymer)
Regarding the gas composition of the second polymerization tank, propylene, ethylene, and nitrogen were continuously added 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 controlling 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. Furthermore, as a polymerization inhibitor, ethanol was continuously supplied so as to be 2.0 g / h to produce a propylene-ethylene copolymer. The powder (impact copolymer consisting of propylene polymer and propylene-ethylene copolymer) finished in the second polymerization tank was continuously extracted into the vessel so that the amount of powder held in the polymerization tank was 60 kg. Nitrogen gas containing moisture was supplied to the vessel to stop the reaction, and an impact copolymer powder was obtained.

<Granulation>
Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (trade name: IRGANOX1010) with respect to 100 parts by weight of the impact copolymer obtained by the above polymerization , Manufactured by BASF Japan Ltd.) 0.05 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.) 0.05 parts by weight, calcium stearate 0 .05 parts by weight was mixed and sufficiently stirred, then melt-kneaded using a twin-screw extruder (Technobel KZW25TW-45MG-NH), the extruded strand was cut and pelletized, and the impact copolymer (Y1) was Obtained.
Table 4 shows the results of analyzing the obtained impact copolymer (Y1).

[Production Example Y2: Production of Impact Copolymer (Y2)]
During the second step of polymerization, the partial pressure of propylene was 1.28 MPaA, the partial pressure of ethylene was 0.22 MPaA, and the molar ratio of hydrogen / (propylene + ethylene) was adjusted to 120 ppm. The impact copolymer (Y2) was produced in the same manner as in Production Example (Y1) except that the amount of ethanol supplied was changed to 1.5 g / h.
Table 4 shows the results of analyzing the obtained impact copolymer (Y2).

[Production Example Y3: Production of Impact Copolymer (Y3)]
<Preparation of prepolymerization catalyst Z2>
The analysis of the catalyst was carried out in the same manner as in Production Example Y1.
(1) Preparation of Solid Component Z2 A 10 L autoclave equipped with a stirrer was sufficiently substituted with nitrogen, and 2 L of purified n-heptane was introduced. Further, 250 g of MgCl ₂ and 1.8 L of Ti (On-Bu) ₄ were added, and a reaction was performed at 95 ° C. for 2 hours. The reaction product was cooled to 40 ° C. and 500 ml of methyl hydrogen polysiloxane (20 centistokes) was added. After 5 hours of reaction at 40 ° C., the precipitated solid product was thoroughly washed with purified n-heptane.
Subsequently, purified n-heptane was introduced to adjust the concentration of the solid product to 200 g / L. Here, 300 ml of SiCl ₄ was added and a reaction was carried out at 90 ° C. for 3 hours. The reaction product was thoroughly washed with purified n-heptane, and purified n-heptane was introduced so that the concentration of the reaction product was 100 g / L. A liquid prepared by mixing 30 ml of phthalic acid dichloride with 270 ml of purified n-heptane was prepared in advance, and the mixed liquid was added to an autoclave and reacted at 90 ° C. for 1 hr. The reaction product was thoroughly washed with purified n-heptane, and purified n-heptane was introduced so that the concentration of the reaction product was 200 g / L. To this, 1 L of TiCl ₄ was added and a reaction was carried out at 95 ° C. for 3 hours. The reaction product was thoroughly washed with purified n-heptane to obtain a slurry of solid component Z2. A portion of this slurry was sampled and dried. As a result of analysis, the Ti content of the solid component Z2 was 2.5 wt%.

(2) Preparation of Solid Catalyst Z2 Next, a 20 L autoclave equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the solid component Z2 slurry was introduced as a solid component. Purified n-heptane was introduced to adjust the solid component concentration to 25 g / L. 50 ml of SiCl ₄ was added and a reaction was performed at 70 ° C. for 1 hr. Thereafter, the temperature was lowered to 30 ° C., and 80g added trimethylvinylsilane 30 ml, a _{t-BuMeSi (OMe) 2 30ml} , the n- heptane dilution of _Et 3 Al as _Et 3 Al, were 2hr reaction at 30 ° C. . The reaction product was thoroughly washed with purified n-heptane to obtain a solid catalyst Z2. A portion of the resulting slurry of solid catalyst Z2 was sampled and dried for analysis. The solid catalyst Z2 contained 1.4 wt% Ti and 7.2 wt% t-BuMeSi (OMe) ₂ .

(3) Prepolymerization Prepolymerization was performed by the following procedure using the solid catalyst Z2 obtained above.
Purified n-heptane was introduced into the slurry, and the solid catalyst concentration was adjusted 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. Next, the gas phase was sufficiently replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum-dried to obtain a prepolymerized catalyst Z2.
This prepolymerized catalyst Z2 contained 2.5 g of polypropylene per 1 g of the solid catalyst. As a result of analysis, 1.1 parts by weight of Ti and 6.8% by weight of t-BuMeSi (OMe) ₂ were contained in the part of the prepolymerized catalyst Z2 excluding polypropylene.

<Polymerization>
The polymerization was carried out using a batch type slurry polymerization reactor. The polymerization tank is a stainless steel autoclave with a stirrer having an internal volume of 400 liters. The source gas used and n-heptane were sufficiently purified.

(First step: production of propylene polymer)
The polymerization tank was sufficiently replaced with propylene gas, and 120 L of n-heptane was introduced as a polymerization solvent. After adjusting the temperature to 70 ° C., 30 g of Et ₃ Al and 12 liters of hydrogen were introduced, and 10 g of the above prepolymerized catalyst Z2 (excluding the prepolymerized polymer) was added. After raising the internal temperature to 75 ° C., polymerization was started by supplying propylene at 20.7 kg / h and hydrogen at 20.6 L / h. After 200 minutes, the supply of propylene and hydrogen was stopped. While the supply of propylene and hydrogen was continued, the pressure in the polymerization tank gradually increased and finally increased to 0.46 MPaG. After the supply of propylene and hydrogen is stopped, residual polymerization is performed using the gas in the polymerization tank, and when the pressure in the polymerization tank becomes 0.35 MPa, the gas in the polymerization tank is purged to 0.03 MPaG. A propylene homopolymer was obtained.
When a part of the obtained propylene polymer was sampled and analyzed, the MFR was 24.0 g / 10 min.
In the measurement of MFR, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (product) was added to the sample propylene polymer. Name: IRGANOX 1010, manufactured by BASF Japan Ltd., Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.), calcium stearate, respectively, in appropriate amounts (about 500 wtppm) Measurement was performed after addition and mixing.

(Second step: production of propylene-ethylene copolymer)
After the completion of the first step, the internal temperature of the polymerization tank was adjusted to 65 ° C., and 16.0 cc of n-butanol was introduced. Then, propylene was supplied at 2.4 kg / h and ethylene was supplied at 1.6 kg / h, and copolymerization of propylene and ethylene in the second step was started. After 90 minutes, the supply of ethylene and propylene was stopped and the gas in the polymerization tank was purged, and then the inside of the tank was sufficiently replaced with nitrogen to complete the polymerization. The pressure in the polymerization tank was 0.03 MPaG when the supply of ethylene and propylene was started, but was 0.09 MPaG when the supply was stopped.
The obtained polymer slurry was transferred to the subsequent post-treatment tank equipped with a stirrer, 2.5 liters of butanol was added, and the treatment was performed at 70 ° C. for 3 hours. Thereafter, the slurry was transferred to a subsequent post-treatment tank equipped with a stirrer, and 100 liters of pure water in which 20 g of sodium hydroxide was dissolved was added for 1 hour of treatment. Thereafter, the aqueous layer was allowed to stand and then separated to remove the catalyst residue. The slurry was transferred to a centrifuge to separate the powder and heptane. The separated powder was dried with a dryer at 80 ° C. for 3 hours to obtain 59.7 kg of impact copolymer.

<Granulation>
Using the impact copolymer obtained above, granulation was performed in the same manner as in Production Example Y1, to obtain an impact copolymer (Y3).
Table 4 shows the results of analyzing the obtained impact copolymer (Y3).

[Production Example Yc4: Production of Impact Copolymer (Yc4)]
During the first step of polymerization, the hydrogen / propylene molar ratio was adjusted to 0.012, the amount of powder held in the polymerization tank was adjusted to 60 kg, and the polymerization temperature was adjusted to 80 ° C. during the second step. In the same manner as in Production Example (Y2), except that the hydrogen / (propylene + ethylene) molar ratio was adjusted to 1680 ppm and the ethanol supply amount was changed to 2.6 g / h. A copolymer (Yc4) was produced.
Table 4 shows the results of analyzing the obtained impact copolymer (Yc4).

[Production Example Y5: Production of Impact Copolymer (Y5)]
In the second step of the polymerization, except that the hydrogen / (propylene + ethylene) molar ratio was adjusted to 500 ppm, and the ethanol supply was changed to 2.2 g / h. In the same manner as in Example (Y1), impact copolymer (Y5) was produced.
Table 4 shows the results of analyzing the obtained impact copolymer (Y5).

[Production Example Y6: Production of Impact Copolymer (Y6)]
During the first step of the polymerization, the hydrogen / propylene molar ratio is adjusted to be 0.027, and further, during the second step of the polymerization, the ethanol supply amount is 1.4 g / h. The impact copolymer (Y6) was produced in the same manner as in Production Example (Y1), except for changing to.
Table 4 shows the results of analyzing the obtained impact copolymer (Y6).

[Example 1]
1. Properties of Polypropylene Resin Composition (Z1) In order to measure the properties of the resin composition (Z1) used for foam molding, the polypropylene pellets (X1) obtained in Production Example X1 and the impact copolymer obtained in Production Example Y1 (Y1) The pellets were blended at 50:50 (weight ratio) and sufficiently stirred, and then melt-kneaded using a single screw extruder under the following conditions, and the extruded strand was cut and pelletized.
Kneading conditions:
Extruder: Diameter 30 mm, L / D = 25 (PMS 30-25, manufactured by IK Corporation)
・ Screw: Full flight CR2.0, Feed part groove depth 4mm + Dalmage ・ Screw speed: 60rpm
・ Set temperature: hopper lower water cooling, C1 to C4 220, 200, 200, 200 ° C.
・ Die: Strand die

Various physical properties of the obtained pellets were measured by the following methods. The results are shown in Table 5.
・ MFR
Measured in accordance with JIS K7210: 1999, Method A, Condition M (230 ° C., 2.16 kg load). The unit is g / 10 minutes.
・ Melting tension (MT)
It measured on the following conditions using the Toyo Seiki Seisakusho Capillograph.
・ Capillary: Diameter 2.0mm, length 40mm
・ Cylinder diameter: 9.55mm
・ Cylinder extrusion speed: 20 mm / min ・ Pickup speed: 4.0 m / min ・ Temperature: 230 ° C.
When the MT is extremely high, the resin may break at a take-up speed of 4.0 m / min. In such a case, the take-up speed is lowered and the tension at the highest speed at which the take-up can be taken is MT. And The unit is gram.

2. Extrusion Foamed Sheet Molding Polypropylene pellets (X1) and impact copolymer pellets (Y1) were dry blended at 50:50 (weight ratio) to obtain a polypropylene resin composition for extrusion foaming (Z1).
To 100 parts by weight of the resin composition (Z1), 0.5 parts by weight of a chemical foaming agent (trade name: Hydrocerol CF40E-J, manufactured by Nippon Boehringer Ingelheim Co., Ltd.) was added as a foam regulator and stirred sufficiently. It is put into the rear single screw extruder and extruded from the physical foaming agent charging hole opened in the extruder cylinder while injecting liquefied CO ₂ using a high-pressure pump, and the width is 750 mm and the Lip width is 0.4 mm through the feed block. A T-die was used to form a sheet.
At this time, using two single-screw extruders, the impact copolymer (Y3) obtained in Production Example Y3 was extruded from each, and laminated on both surface layers with a feed block to form a multilayer sheet of two types and three layers.
The extruded sheet is a 50 mm diameter roll installed immediately after the die exit. First, one side is cooled, then both sides are cooled by four 100 mm diameter rolls, and the sheet is taken up at a constant speed by a nip roll. Processed into a shape.
The operating conditions and sheet forming conditions of each extruder at this time are as follows.
・ Extruder (foamed layer)
65 mm diameter, L / D = 45, position at L / D = 20 from CO2 inlet root Screw rotation speed: 75 rpm
Set temperature: C1-180, C2-4-240, C5-190, C6-9-175 ° C
Discharge rate: Approximately 65kg / h
・ Extruder (both surface layers)
Diameter 30mm, L / D = 28
Screw rotation speed: 50rpm
Set temperature: C1-180, C2-230, C3-190, C4-180 ° C
Discharge rate: About 5kg / h
Sheet molding Feed block temperature: 175 ° C
Die temperature: 175 ° C
Cooling roll temperature: 15 ° C
Winding speed: 4.5 m / min
Various characteristics of the obtained foamed sheet were measured by the following methods. The results are shown in Table 5.

3. Foam sheet characteristics and average cell diameter:
A 25 mm square sample was cut out from the polypropylene resin foam sheets obtained in the examples and comparative examples. Using a stereomicroscope (Nikon: SMZ-1000-2 type), the foam layer cross section is enlarged and projected, and from the number of bubbles and the bubble diameter in the cross section, the bubble diameter of the cross section in the extrusion direction and the cross section in the vertical direction are calculated. The average value was defined as the average cell diameter of the foam layer.
·density:
A test piece was cut out from the polypropylene-based (multi-layer) foamed sheet obtained in Examples and Comparative Examples, and the test piece weight (g) was obtained by dividing by the volume (cm ³ ) determined from the outer dimensions of the test piece. The density was determined by measuring according to JIS K7222.
・ Open cell ratio:
Test pieces were cut out from the polypropylene-based (multi-layer) foamed sheets obtained in Examples and Comparative Examples, and measured according to the method described in ASTM D2856 using AirPycnometer (manufactured by Tokyo Science Co., Ltd.).

・ Extensibility and sheet appearance evaluation:
Appearance evaluation of the foamed sheet was evaluated based on the following criteria for the polypropylene resin foamed sheets obtained in each of Examples and Comparative Examples.
(Double-circle): It spreads uniformly and there are very few thickness spots. The cell shape is fine and uniform, and there is no partial depression (sink), and the sheet appearance is beautiful.
○: Uniformly spread with few thickness spots. The bubble shape is uniform and there are no partial depressions.
(Triangle | delta): A spreading defect is recognized and there exists a thickness spot. The bubble shape is uniform, but a partial recess (sink) is generated at a poorly spread portion.
X: Uniform extension is difficult and there are many thickness spots. Bubbles are coalesced and there are partial depressions.

・ Thermal formability and resistance to drawdown:
In order to evaluate the thermoformability and drawdown resistance of the obtained foamed sheet, the following evaluation was performed using a sag tester (manufactured by Misuzu River Lee).
A test piece having a size of 300 mm × 300 mm was cut out from the polypropylene resin foam sheet obtained in each example and each comparative example, and fixed to a frame having an inner size of 260 mm × 260 mm. A frame with a fixed sheet is set in a droop tester, the sheet is heated by sliding a set of heating panels on the sheet, and the time displacement in the height direction at the center of the sheet from the start of heating is measured with a laser displacement meter. .
At this time, the heating plate has two heating plates on which infrastein heaters are arranged, and the vertical position is set so that each position is 120 mm with respect to the set sheet. The heater is previously controlled at 440 ° C.
From the measured displacement data, read back time T1 and time T2 until the hole is opened, sag amount D (T2) at time T2 is read, and as a moldable time range (= T2-T1) [s], in the moldable range The average sag velocity VD (= D (T2) / (T2−T1)) [mm / s] is defined and used for evaluation.
At this time, each measured value uses the average value of the result of performing a sag test on each of the three sheets. The results are shown in Table 5.
The measurement result of the sag test in Example 1 is shown in FIG.

4). Thermoforming The obtained sheet was cut into 45 cm × 45 cm, and both surfaces were heated using a test vacuum / pressure forming machine (FKS type manufactured by Asano Laboratory Co., Ltd.), and then a container was formed by vacuum forming.
At this time, the container was produced by changing the heating time and the mold position so that a container as clean as possible could be molded.
At this time, the range of the heating time in which the container is in a good shape is wide, and the easier the adjustment of the mold position, the better the thermoformability, and the sensory evaluation of the moldability was carried out (evaluation criteria: good ◎ ~ ○ ~ △ ~ × 4 stages of evil).
Moreover, the external appearance of the obtained container was visually evaluated (evaluation criteria: 4 stages of good 〜 to ○ to △ to × bad). The results are shown in Table 5.

[Example 1 ']
Commercially available homopolypropylene pellets [Nippon Polypro Co., Ltd.] with respect to 100 parts by weight of the polypropylene resin composition (Z1) comprising 50:50 (weight ratio) of the polypropylene pellets (X1) and impact copolymer (Y1) pellets used in Example 1. Manufactured, MA1B (MFR = 21 g / 10 min)] was added in an amount of 70 parts by weight to obtain a diluted resin composition (Z1 ′).
The characteristics of (Z1 ′) were evaluated in the same manner as in Example 1. The results are shown in Table 5.
Moreover, sheet | seat molding was performed similarly to Example 1 except having used (Z1 ') instead of the resin composition (Z1), and various physical properties were measured. The results are shown in Table 5.

[Example 2]
Evaluation similar to Example 1 was performed except that the polypropylene pellet (X2) obtained in Production Example X2 was used as the polypropylene (X). The results are shown in Table 5.

[Example 2 ']
As polypropylene (X), the same evaluation as in Example 1 ′ was performed except that the polypropylene pellet (X2) obtained in Production Example X2 was used. The results are shown in Table 5.

[Example 3]
The same evaluation as in Example 1 was performed except that the ratio of the polypropylene pellet (X1) and the impact copolymer (Y1) pellet was set to 70:30 (weight ratio). The results are shown in Table 5.

[Example 4]
Evaluation similar to Example 3 was performed except that the polypropylene pellet (X5) obtained in Production Example X5 was used as the polypropylene (X). The results are shown in Table 5.

[Example 4 ']
Commercially available homopolypropylene pellets [Nippon Polypro Co., Ltd.] with respect to 100 parts by weight of the polypropylene resin composition (Z1) comprising 70:30 (weight ratio) of the polypropylene pellets (X5) and impact copolymer (Y1) pellets used in Example 4. Manufactured, MA1B (MFR = 21 g / 10 min)] was added in an amount of 150 parts by weight to obtain a diluted resin composition (Z1 ′).
Evaluation similar to Example 1 'was performed. The results are shown in Table 5.

[Example 5]
Evaluation similar to Example 3 was performed except having used the polypropylene pellet (X6) obtained by manufacture example X6 as polypropylene (X). The results are shown in Table 5.

[Example 6]
The same evaluation as in Example 3 was performed except that the impact copolymer pellet (Y2) obtained in Production Example Y2 was used as the impact copolymer (Y). The results are shown in Table 5.

[Example 6 ']
100 parts by weight of commercially available homopolypropylene pellets [manufactured by Nippon Polypro Co., Ltd., MA1B (MFR = 21 g / 10 min)] were added to the resin composition (Z) used in Example 6 and diluted (Z ′). The same evaluation as in Example 6 was performed except that was used. The results are shown in Table 5.

[Example 7]
Evaluation was performed in the same manner as in Example 3 except that the impact copolymer pellet (Y3) obtained in Production Example Y3 was used as the impact copolymer (Y). The results are shown in Table 5.

[Example 8]
The same evaluation as in Example 6 ′ was performed except that the impact copolymer pellet (Y5) obtained in Production Example Y5 was used as the impact copolymer (Y). The results are shown in Table 5.

[Example 9]
The same evaluation as in Example 6 ′ was performed except that the impact copolymer pellet (Y6) obtained in Production Example Y6 was used as the impact copolymer (Y). The results are shown in Table 5.

[Comparative Example 1]
Evaluation similar to Example 1 was performed except having used the polypropylene pellet (Xc3) obtained by manufacture example Xc3 which does not satisfy the requirements as polypropylene (X). The results are shown in Table 6.

[Comparative Example 1 ']
Evaluation similar to Example 1 'was performed except having used the polypropylene pellet (Xc3) obtained by manufacture example Xc3 which does not satisfy the requirements as polypropylene (X). The results are shown in Table 6.

[Comparative Example 2]
Evaluation similar to Example 3 was performed except that the polypropylene pellet (Xc4) obtained in Production Example Xc4 not satisfying the requirements as polypropylene (X) was used. The results are shown in Table 6.

[Comparative Example 2 ']
Evaluation similar to Example 1 'was performed except having used the polypropylene pellet (Xc4) obtained by manufacture example Xc4 which does not satisfy the requirements as polypropylene (X). The results are shown in Table 6.

[Comparative Example 3]
Evaluation similar to Example 4 'was performed except having used the polypropylene pellet (Xc7) obtained by manufacture example Xc7 which does not satisfy the requirements as polypropylene (X). The results are shown in Table 6.

[Comparative Example 4]
The same evaluation as in Example 1 was performed using only polypropylene (X1) without using the impact copolymer (Y). The results are shown in Table 6.

[Comparative Example 5]
Without using the impact copolymer (Y), only 100 parts by weight of polypropylene (X1) was added with 40 parts by weight of commercially available homopolypropylene pellets [manufactured by Nippon Polypro, MA1B (MFR = 21 g / 10 min)]. Evaluation similar to Example 1 was performed. The results are shown in Table 6.

[Comparative Example 6]
The same evaluation as in Example 3 was performed except that the polypropylene pellet (Yc4) obtained in Production Example Yc4 not satisfying the requirements as the impact copolymer (Y) was used. The results are shown in Table 6.

  From the comparison between Examples and Comparative Examples, it is clear that the polypropylene resin composition for extrusion foam molding in the present invention is excellent in foaming characteristics, high in heat molding suitability for foamed sheets, and excellent in appearance of the resulting container.

  The polypropylene resin composition for extrusion foam molding of the present invention has excellent foaming characteristics, high thermoforming suitability of the foamed sheet, and excellent appearance of the resulting container. It can be suitably used for vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery, and building materials, and has an extremely high industrial value.

Claims (10)

Polypropylene resin composition containing polypropylene (X) 5 to 99 wt% and impact copolymer (Y) 1 to 95 wt% composed of propylene (co) polymer (YH) and propylene-ethylene copolymer (YC) ( Z) [However, the total of polypropylene (X) and impact copolymer (Y) is 100 wt%. ], And
The polypropylene (X) satisfies the following characteristics (Xi) to (X-iv),
The propylene (co) polymer (YH) satisfies the following characteristics (YH-i) to (YH-ii):
The propylene-ethylene copolymer (YC) satisfies the following characteristics (YC-i) to (YC-ii):
The impact copolymer (Y) satisfies the following characteristics (Yi), and the polypropylene resin composition (Z) satisfies the following characteristics (Zi) to (Z-ii): A polypropylene resin composition for extrusion foam molding.
Characteristic (Xi): Long chain branching.
Characteristic (X-ii): Melt tension (MT) measured at 230 ° C. is 2 to 10 g.
Characteristic (X-iii): MFR exceeds 5 g / 10 min and is 20 g / 10 min or less.
Characteristic (X-iv): 25 degreeC xylene soluble component amount (CXS) is less than 5 wt% with respect to polypropylene (X) whole quantity.
Characteristic (YH-i): a propylene homopolymer or a copolymer of propylene (copolymer) with at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms. ) When the polymer (YH) is a copolymer, the total content of ethylene and α-olefin in (YH) exceeds 0 and is 3 wt% or less.
Characteristic (YH-ii): MFR is 1 to 100 g / 10 min.
Characteristic (YC-i): The ethylene content in the propylene-ethylene copolymer (YC) is 10 to 90 wt% with respect to the total amount of the propylene-ethylene copolymer (YC).
Characteristic (YC-ii): The intrinsic viscosity measured in 135 ° C. decalin is 5 to 20 dl / g.
Characteristic (Yi): The content of the propylene-ethylene copolymer (YC) in the impact copolymer (Y) is 1 wt% or more and less than 50 wt% with respect to the total amount of the impact copolymer (Y).
Characteristic (Zi): MFR is 0.1 to 20 g / 10 min.
Characteristic (Z-ii): Melt tension (MT) measured at 230 ° C. is 1 to 7 g. A polypropylene resin composition (Z ′) containing 0.1 to 1000 parts by weight of a propylene (co) polymer (H) with respect to 100 parts by weight of the polypropylene resin composition (Z) according to claim 1,
The propylene (co) polymer (H) is a propylene homopolymer or a copolymer of propylene with at least one olefin selected from the group consisting of ethylene and an α-olefin having 4 to 10 carbon atoms. When the propylene (co) polymer (H) is a copolymer, the total content of ethylene and α-olefin in the propylene (co) polymer (H) exceeds 0 and is 3 wt% or less. A polypropylene resin composition for extrusion foam molding characterized by the above. 3. The polypropylene resin composition for extrusion foam molding according to claim 1 or 2, wherein the polypropylene (X) further satisfies the following property (Xv).
Characteristic (Xv): The branching index g ^{′ at an} absolute molecular weight Mabs of 1 million is 0.3 or more and less than 1.0. The polypropylene resin composition for extrusion foam molding according to any one of claims 1 to 3, wherein the polypropylene (X) further satisfies the following property (X-vi).
Characteristic (X-vi): strain hardening degree (λmax) in measurement of extensional viscosity is 5-12. The polypropylene resin composition for extrusion foam molding according to any one of claims 1 to 4, wherein the impact copolymer (Y) further satisfies the following property (Y-ii).
Characteristic (Y-ii): MFR is 0.1 to 20 g / 10 min.   The foaming agent is contained in an amount of 0.05 to 6.0 parts by weight with respect to a total of 100 parts by weight of the polypropylene (X) and the impact copolymer (Y). The polypropylene resin composition for extrusion foam molding described.   A polypropylene-based foam sheet produced by using the polypropylene resin composition for extrusion foam molding according to any one of claims 1 to 6.   A polypropylene-based multilayer foamed sheet, wherein a non-foamed layer is laminated on at least one surface of the polypropylene-based foamed sheet according to claim 7.   The non-foamed layer has an impact copolymer (Y ′) that satisfies the characteristics and requirements to be satisfied by the impact copolymer (Y) according to claim 1 [wherein the impact copolymer (Y ′) is the same as the impact copolymer (Y)]. It may be different or different. The polypropylene-based multilayer foamed sheet according to claim 8, comprising a polypropylene resin composition containing   A thermoformed article produced by thermoforming the polypropylene foam sheet or the polypropylene multilayer foam sheet according to any one of claims 7 to 9.

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