JP6809564B2 - Manufacturing method of polypropylene resin foam molding material and molded product - Google Patents

Description

The present invention relates to a polypropylene resin composition for foam molding, and more specifically, a foam cell that provides a film in which the number of gels contained per unit area is extremely small, has a high closed cell ratio, is dense, and has a uniform size. The present invention relates to a polypropylene resin composition for foam molding capable of forming the above, and further, a foam molded product or a foamed sheet produced by using the resin composition, and the foamed molded product or the foamed sheet are heat-molded. Regarding molded products.

Foam molding is one of the important molding methods for polypropylene. Various molded bodies obtained by extrusion foam molding and injection foam molding have excellent properties such as heat insulation, sound insulation, cushioning, and energy absorption, and are used in a wide range of applications. Particularly in recent years, from the viewpoint of environmental problems, weight reduction of materials and reduction of environmental load have become important development factors, and further improvement of foaming characteristics is desired for resin as a raw material. ..
In general, polypropylene has a linear molecular structure and a standard molecular weight distribution, so that the melt tension is low and it is difficult to perform foam molding. In order to make up for this drawback, various technological developments have been made in the past as a method for improving the melt tension of polypropylene.
One of the typical methods is to generate a radical to introduce a long chain branch. Long-chain branching refers to a branched structure consisting of a molecular chain having a main chain carbon number of several tens or more and a molecular weight of several hundreds or more, and is considered to have an effect of improving melt tension. As a specific method, a method using high-energy ionizing radiation (see Patent Document 1), a method using an organic peroxide (see Patent Document 2), and the like are disclosed.
However, the method using high-energy ionizing radiation requires special equipment for using radiation, and the manufacturing cost is inevitably high. In addition, since radicals generated by high-energy ionizing radiation remain, there are quality problems such as yellowing and other appearance problems, and physical properties that change over time and become unstable. ing. In addition, the method using an organic peroxide has quality problems such as contamination by decomposition products of the organic peroxide, odor, and yellowing, and further, the organic peroxide is unstable, so that it is manufactured. It has a big problem from the viewpoint of time safety.

Another method for improving the melt tension of polypropylene is to introduce a component having an extremely high molecular weight. As specific methods, a method of producing an ultra-high molecular weight component by multistage polymerization (see Patent Documents 3 and 4) and a method of producing an ultra-high molecular weight polyethylene component by prepolymerization (see Patent Document 5) are known. Has been done.
However, polypropylene produced by such a method has a considerably lower melt tension than polypropylene having long-chain branches, and therefore its foaming properties are not satisfactory and the applicable range is limited. I have a problem.
In order to solve such problems and problems, the development of a technique for forming a long-chain branch without generating radicals has been promoted (see Patent Documents 6 to 9). This is a technique for forming a long-chain branch by producing a macromonomer having a terminal unsaturated bond by polymerizing a monomer using a metallocene catalyst having a specific structure and copolymerizing it with propylene. By these methods, problems such as odor associated with radical generation could be solved, but on the other hand, the amount of long-chain branches formed was small, the melt tension was insufficient, the foaming characteristics were poor, and the melt tension was reduced. Even if it can be made high, even if the cell formation at the time of foaming is good, the ductility is low, so that the cell bursts at the time of sheet formation, the appearance of the sheet surface deteriorates, or the fluidity becomes low. Problems such as the inability to increase the extrusion rate and the deterioration of productivity have occurred. In particular, under conditions where the extrusion rate is high and the molding speed is high, it is not possible to achieve both the formation of foamed cells and the prevention of cell destruction during expansion, which is a major problem.

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 Patent Documents 10 to 14 disclose blends of various polypropylenes, it cannot be said that sufficient foaming properties are obtained. In particular, the problems such as insufficient melt tension, insufficient fluidity, and poor appearance that occur when introducing long-chain branches using macromonomers are not improved at all, and polypropylene having long-chain branches is simply expensive. To the extent that the cost is reduced by diluting.

Under such circumstances, the present inventors further, when the polypropylene resin is foam-molded, if the surface of the foam-molded article is significantly uneven, a film may be attached to the surface of the molded article immediately after foam molding or by post-processing. Even so, there are problems such as difficulty in adhesion and peeling of the film (= delamination), and even if you try to print directly on the surface of the product, the printing will be difficult and the design will deteriorate. There were strong calls for improvement of the shortcomings of.

Japanese Unexamined Patent Publication No. 62-121704 Special Table 2001-524565 WO99 / 07752 Japanese Unexamined Patent Publication No. 2001-335666 WO97 / 14725 Special Table 2001-525460 JP-A-2009-275207 JP-A-2009-293020 JP-A-2009-299029 Japanese Unexamined Patent Publication No. 2001-226510 JP-A-2002-356573 Japanese Unexamined Patent Publication No. 2010-121054 JP-A-2009-275210 Japanese Unexamined Patent Publication No. 2011-068819 Japanese Unexamined Patent Publication No. 2013-199643 JP 2015-040213

An object of the present invention is to provide a polypropylene resin composition having a high melt tension, which can be suitably used for various moldings in view of the current state of the prior art, and has excellent physical properties of the obtained product. Particularly in the field of foam molding, a polypropylene resin composition for obtaining a foam molded product having a uniform and fine foam cell, good spreadability, and an improved surface appearance of a molded product was provided and used. An object of the present invention is to provide an effervescent sheet and a molded product obtained by thermoforming using the foamed sheet.

As a result of intensive research to solve the above problems, the present inventors have suppressed the number of gels of a specific size measured under predetermined conditions to a certain value or less, thereby forming such foam molding. It was found that the surface appearance of the foamed molded product prepared by using the polypropylene resin composition for use was kept good, and the present invention was completed based on this finding.
The relationship between the number of gels of a specific size measured under predetermined conditions in the polypropylene resin composition for foam molding and the surface appearance of the foam molded product is completely described or suggested in known documents. I would like to clarify that it has not been done.

That is, the present invention includes the following inventions.
[1] Containing 10 to 99% by weight of polypropylene (X) and 1 to 90% by weight of propylene block copolymer (Y), the melt tension (MT) measured at 230 ° C. is 1 g or more, and the thickness is 25 μm. A polypropylene resin composition for foam molding in which the number of gels having a major axis of 0.5 mm or more is 50 pieces / m ² or less when a non-stretched film is used.
[2] The polypropylene resin composition for foam molding according to [1], wherein the number of gels having a major axis of 0.4 mm or more and less than 0.5 mm is 400 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used.
[3] When a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.4 mm or more and less than 0.5 mm is 400 / m ² or less, and the number of gels having a major axis of 0.3 mm or more and less than 0.4 mm is The polypropylene resin composition for foam molding according to [1], which is 2000 pieces / m ² or less.
[4] The polypropylene resin composition for foam molding according to any one of [1] to [3], wherein the melt tension (MT) measured at 230 ° C. is 3 g or more.
[5] The polypropylene resin composition for foam molding according to any one of [1] to [4], wherein the melt tension (X) of polypropylene (X) measured at 230 ° C. is 3 g or more.
[6] The polypropylene resin composition for foam molding according to any one of [1] to [4], wherein the polypropylene (X) satisfies the following characteristics (X-i) to (X-iv).
Characteristic (X-i): Has a long chain branch.
Characteristic (X-ii): The melt tension (MT) measured at 230 ° C. is 3 to 25 g.
Characteristic (X-iii): Melt flow rate (MFR) is greater than 0.9 g / 10 min and less than 15 g / 10 min.
Characteristic (X-iv): The amount of xylene-soluble component (CXS) at 25 ° C. is less than 5 wt% based on the total amount of polypropylene (X).
[7] A propylene (co) polymer (Y-1) in which the propylene-based block copolymer (Y) may contain a comonomer of 10% by weight or less and a propylene having an ethylene content of 11.0 to 38.0% by weight. -It is composed of an ethylene copolymer (Y-2), and when the total amount of the propylene block copolymer (Y) is 100% by weight, (Y-1) is 50 to 99% by weight and (Y-2) is 1 to 1. The polypropylene resin composition for foam molding according to any one of [1] to [6], which is 50% by weight.
[8] The polypropylene resin composition for foam molding according to [7], wherein the propylene-based block copolymer (Y) is produced by step-growth polymerization.
[9] Foaming made of polypropylene (X) having a melt tension (230 ° C.) of 3 g or more and a number of gels having a major axis of 0.5 mm or more of 10 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used. Polypropylene resin for molding.
[10] The polypropylene resin for foam molding according to [9], wherein the number of gels having a major axis of 0.2 mm or more and less than 0.5 mm is 50 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used.
[11] When a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.2 mm or more and less than 0.5 mm is 50 pieces / m ² or less, and the number of gels having a major axis of 0.1 mm or more and less than 0.2 mm is The polypropylene resin for foam molding according to [9], which is 100 pieces / m ² or less.
[12] The polypropylene resin for foam molding according to any one of [9] to [11], wherein the polypropylene (X) satisfies the following characteristics (X-i) to (X-iv).
Characteristic (X-i): Has a long chain branch.
Characteristic (X-ii): The melt tension (MT) measured at 230 ° C. is 3 to 25 g.
Characteristic (X-iii): Melt flow rate (MFR) is greater than 0.9 g / 10 min and less than 15 g / 10 min.
Characteristic (X-iv): The amount of xylene-soluble component (CXS) at 25 ° C. is less than 5 wt% based on the total amount of polypropylene (X).
[13] To 100 parts by weight of the polypropylene resin composition for foam molding according to any one of [1] to [8] or the polypropylene resin for foam molding according to any one of [9] to [12]. On the other hand, a polypropylene resin foam molding material containing 0.05 to 6.0 parts by weight of a foaming agent.
[14] A polypropylene resin foam molded product obtained by extrusion molding the polypropylene resin foam molding material according to [13].
[15] A polypropylene resin laminated foam molded product obtained by co-extruding the polypropylene resin foam molded product according to [14] and a non-foamed layer made of a thermoplastic resin composition.
[16] The polypropylene resin laminated foam molded article according to [15], wherein the thermoplastic resin composition contains 50 parts by weight or less of an inorganic filler with respect to 100 parts by weight of the thermoplastic resin.
[17] A molded product obtained by thermoforming the polypropylene resin foam molded product or laminated foam molded product according to any one of [14] to [16].
[18] A molded product obtained by subjecting the polypropylene resin foam molding material according to [13] to any molding method of injection molding, thermoforming, blow molding or bead foam molding.
[19] The molded article according to any one of [14] to [16], which is a sheet.
[20] A foamed sheet of the polypropylene resin composition for foam molding according to any one of [1] to [8] or the polypropylene resin for foam molding according to any one of [9] to [12]. Use for manufacturing.

The polypropylene resin composition for 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, has a high closed cell ratio, and is dense and uniform in size. A foam molded product having a cell can be produced. In addition, it is possible to produce a foamed sheet having a very high fluidity and ductility and having a beautiful appearance at a high extrusion rate. Further, while having such high foaming characteristics, it is also excellent in drawdown resistance and thermoformability.
The foam molded product thus obtained is excellent in appearance, thermoforming property, impact resistance, light weight, rigidity, heat resistance, heat insulating property, 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.

It is a figure explaining the conceptual diagram of CFC-FT-IR.

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

The polypropylene resin composition for foam molding of the present invention (hereinafter, also referred to as a resin composition) contains 10 to 99 wt% of polypropylene (X) and 1 to 90 wt% of propylene block copolymer (Y). It is characterized by containing. It is preferable that polypropylene (X) and propylene-based block copolymer (Y) satisfy specific requirements and specific physical characteristics.
In the following, polypropylene (X), propylene-based block copolymer (Y), and the properties that they preferably satisfy will be described in detail for each 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. Is. The polypropylene (X) of the present invention is preferably a propylene homopolymer because of its high heat resistance and rigidity.

Preferably, the polypropylene (X) in the present invention satisfies the following characteristics (X-i) to (X-iv).
Characteristic (X-i): Has a long chain branch.
Characteristic (X-ii): The melt tension (MT) measured at 230 ° C. is 3 to 25 g.
Characteristic (X-iii): Melt flow rate (MFR) is greater than 0.9 g / 10 min and less than 15 g / 10 min.
Characteristic (X-iv): The amount of xylene-soluble component (CXS) at 25 ° C. is less than 5 wt% based on the total amount of polypropylene (X).

Among such polypropylenes (X), those satisfying the following characteristics (Xv) are more preferable, and those satisfying the following characteristics (X-vi) are most preferable.
Characteristics (X-v): absolute molecular weight Mabs 1,000,000 in branching index g ^'of 0.3 or more and less than 1.0.
Characteristic (X-vi): The degree of strain hardening (λmax) in the measurement of elongation viscosity is 5 to 15.
The details will be described below in order.

I-1. Characteristic (X-i): Long-chain branching Preferably, the polypropylene (X) according to the present invention has a long-chain branching. Long-chain branching refers to a branched structure consisting of a molecular chain having a main chain carbon number of several tens or more and a molecular weight of several hundreds or more, and the number of carbon atoms formed by copolymerizing with an α-olefin such as 1-butene. Is distinguished from several short chain branches.
There are several methods for investigating whether or not polypropylene has long-chain branches, but the one based on the rheological properties of the resin as shown in the characteristics (X-ii) and (X-vi) is simply used. As a more rigorous identification method, as shown in the feature (Xv), there are a method using the relationship between the molecular weight and the viscosity, a method using ¹³ C-NMR, and the like. Regarding the latter, Patent Document 7 and Macromol. Chem. Phys. 2003, vol. Please refer to 204 and 1738 for detailed explanations.

I-2. Characteristic (X-ii): Melt tension (MT)
Preferably, the polypropylene (X) according to the present invention has a melt tension (MT) of 3 to 25 g, as shown in the above-mentioned characteristic (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.
Capillaries: diameter 2.0 mm, length 40 mm
Cylinder diameter: 9.55 mm
Piston extrusion speed: 20 mm / min Pick-up speed: 4.0 m / min (However, if the MT is too high and the resin breaks, reduce the pick-up speed and measure at the maximum speed that can be picked up.)
Temperature: 230 ° C

Melt tension (MT) is recognized as an important factor in foam molding, and many patent documents define MT.
For example, Patent Document 7 discloses a propylene polymer having high MT and swell and excellent molding processability. Regarding MT, there is a description of a preferable range in the paragraph [0078], and it is mentioned that the higher the MT, the better, and the most preferable is 15 g or more. Therefore, Patent Document 7 does not have any description suggesting a specific MT value that is preferable in the present invention, and the present invention states that polypropylene having a long-chain branch is preferably from 3 g or more, which has a relatively low MT. The technical idea of the invention is fundamentally different.
Further, Patent Documents 8 and 9 disclose resin compositions for extrusion foam molding and polypropylene-based foam sheets, respectively. The description regarding MT is described in paragraphs [0074] and [0076], respectively, but the description content is the same as that of Patent Document 7, and there is no description suggesting a specific MT value preferable in the present invention.
Further, Patent Document 10 discloses a polypropylene-based resin foam produced by extrusion foaming using a mixture of high MT polypropylene and low MT polypropylene having long-chain branches. In this case as well, although there is a detailed description in the paragraph [0014], it is stated that the MT is preferably higher, and there is no description suggesting a specific MT value that is preferable in the present invention.
Further, Patent Document 11 discloses a polypropylene-based resin extruded foam sheet using a mixture of a high MT polypropylene resin and a low MT polypropylene resin as a base resin. An example of a polypropylene resin having a high MT is described in the paragraph [0015] and has a long chain branch or a crosslink. However, as stipulated in claim 1 of the claims, the MT is 10 cN or more. The higher the value, the more preferable the description (1 g = 0.98 cN), and there is no description suggesting a preferable specific MT value in the present invention.
Further, in Patent Document 12, hydrogen addition of low MFR polypropylene, specific specified propylene / ethylene block copolymer, polypropylene containing olefin polymer having extremely high intrinsic viscosity, and styrene / conjugated diene block copolymer. A polypropylene-based resin composition comprising a thermoplastic resin such as a product is disclosed. Polypropylene containing an olefin polymer having an extremely high intrinsic viscosity corresponds to polypropylene having a high MT, but Patent Document 12 describes a suggestion regarding a long-chain branched polypropylene having a specific MT value preferable in the present invention. Not at all. In addition, polypropylene containing an olefin polymer having an extremely high intrinsic viscosity disclosed in Patent Document 12 has difficulty in dispersing the olefin polymer having an extremely high intrinsic viscosity, has a poor bright spot, and tends to deteriorate the appearance of the molded product. It also includes problems such as.
Further, Patent Document 13 discloses a polypropylene-based foamed stretched film obtained by stretching a propylene resin composition composed of polypropylene having a long-chain branch, a propylene-based polymer, and a foaming agent in at least one direction. There is. Also in this case, as described in the paragraph [0072], the MT is preferably high, and there is no description suggesting a specific MT value which is preferable in the present invention.

Preferably, the polypropylene (X) according to the present invention has an MT of 3 to 25 g. Regarding the lower limit of MT, it is preferable that MT is 3 g or more. As a result, it is possible to maintain a tension that does not cause foaming during foam cell formation, suppress an increase in the open cell ratio, keep the cell diameter small, and make the cell size uniform. Regarding the upper limit of MT, MT is preferably 24 g or less, more preferably MT is 20 g or less, and most preferably 15 g or less. As a result, the ductility during extrusion molding can be improved, the appearance of the sheet, film, molded body and the like can be improved, foam rupture due to poor spreading can be prevented, and an increase in the open cell ratio can be suppressed.
Specific methods for controlling MT within the above range include a method of changing the number of long-chain branches by adjusting the catalyst production method (particularly the carrying ratio of the complex) and within the range of the characteristic (X-iii). There is a way to adjust the MFR with. If the number of long-chain branches is increased or the MFR is lowered, the MT becomes higher. On the other hand, in order to lower the MT, it may be adjusted in the opposite direction.

I-3. Characteristic (X-iii): MFR
Preferably, the polypropylene (X) according to the present invention has an MFR of more than 0.9 g / 10 minutes and 15 g / 10 minutes or less, as shown in the above-mentioned characteristic (X-iii).
The MFR in the present invention is the method A of JIS K7210: 1999 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic", condition M (230 ° C., 2.16 kg load). 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 preferable.
For example, in Patent Document 7, there is a description of a preferable range for MFR in the paragraph [0037], and in the case of extrusion foam molding, it is described that a relatively low value is preferable, and the most preferable range is 1. It is described as 0 to 3.0 g / 10 minutes. Therefore, there is no description in Patent Document 7 that suggests a specific MFR value that is preferable in the present invention, which is different from the present invention in which 0.9 g / 10 minutes is preferable and 15 g / 10 minutes or less is preferable. ..
Further, in Patent Documents 8 and 9, although the description regarding MFR is in paragraphs [0035] and [0037], respectively, it is described that a relatively low value is preferable as in Patent Document 7, and it is most preferable. The range is described as 2-5 g / 10 minutes. Therefore, neither patent document has any description suggesting a specific MFR value preferable in the present invention.
Further, in Patent Document 10, although there is no description about MFR in the detailed description, the values (MI) of Examples are 1.8, 3.0 g / 10 minutes (paragraph [0030]), and in the present invention. There is no description suggesting a preferred specific MFR value.
Further, in Patent Document 11, there is a description about the MFR ratio of the high MT polypropylene resin and the low MT polypropylene resin, but there is no detailed description about the MFR value itself. The MFR value of the examples is 3.2 g / 10 min (paragraph [0052]), and there is no description suggesting a specific MFR value preferable in the present invention.
Further, in Patent Document 12, polypropylene containing an olefin polymer having an extremely high intrinsic viscosity corresponds to polypropylene having a high MT, and a detailed description of the MFR is given in paragraph [0047], and the most preferable range is It is described as 0.2 to 5.0 g / 10 minutes. There is no suggestion in this patent document regarding long chain branched polypropylene having a particular MFR value preferred in the present invention.
Further, also in the case of Patent Document 13, as described in the paragraph [0034], it is preferable that the MFR is low, and the most preferable range is described as 2 to 5 g / 10 minutes. There is no description suggesting a specific MFR value that is preferable in the present invention.

Preferably, the polypropylene (X) according to the present invention has an MFR of more than 0.9 g / 10 minutes and 15 g / 10 minutes or less. Regarding the lower limit of MFR, it is preferably 1 g / 10 minutes or more, more preferably 1.2 g / 10 minutes or more, and most preferably 1.5 g / 10 minutes or more. As a result, the ductility during extrusion molding can be improved, the appearance of the sheet, film, molded body and the like can be improved, foam rupture due to poor spreading can be prevented, and an increase in the open cell ratio can be suppressed. The upper limit of MFR is preferably 14 g / 10 minutes or less, more preferably 13 g / 10 minutes or less, further preferably 12 g / 10 minutes or less, and most preferably 10 g / 10 minutes or less. As a result, it is possible to suppress the generation of a portion that is excessively stretched during the formation of the foam cell, prevent an increase in the open cell ratio due to foam rupture, keep the cell diameter small, and make the cell size uniform.
As a specific method for adjusting the MFR within the above range, a method for changing the amount of hydrogen added during polymerization can be mentioned. Since hydrogen acts as a chain transfer agent in the polymerization of propylene, the MFR can be increased by increasing the amount of hydrogen added, and conversely, the MFR can be decreased by decreasing the amount of hydrogen added. The value of MFR with respect 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 grasped in advance according to the catalyst species and other polymerization conditions, and the desired MFR can be obtained. Adjusting the hydrogen concentration to a value is extremely easy for those skilled in the art.

I-4. Characteristics (X-iv): 25 ° C. xylene-soluble component amount (CXS)
Preferably, the polypropylene (X) according to the present invention has a 25 ° C. xylene-soluble component amount (CXS) of less than 5 wt% as shown in the above-mentioned property (X-iv) (however, the total amount of polypropylene (X) is used. 100 wt%). The 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 prepare a solution, and then left at 25 ° C. for 12 hours. Then, the precipitated polymer is filtered off, p-xylene is evaporated from the filtrate, and dried under reduced pressure at 100 ° C. for 12 hours to recover the xylene-soluble component at 25 ° C. The ratio [% by weight] of the weight of the recovered component to the weight of the charged sample is defined as CXS.

CXS is a general index representing a low crystallinity polymer component, and by setting this value to less than a predetermined value, the content of the low crystallinity component in polypropylene (X) becomes high, and during molding or in a product. It is possible to prevent problems from occurring in itself. For example, it is possible to prevent the problem of rheumatism and the stickiness of the surface of the sheet, film, and product during extrusion foam molding. Preferably, the polypropylene (X) according to the present invention has a CXS of less than 5 wt%. The CXS is preferably less than 3 wt%, more preferably less than 1 wt%, and most preferably less than 0.5 wt%. The lower limit of CXS is not particularly limited, but if it is preferably 0.01 wt% or more, more preferably 0.05 wt% or more, the effect of the additive is likely to be exhibited.
As a specific method for adjusting CXS to the above range, selection of a catalyst can be mentioned. The most important factor that determines the CXS of polypropylene having a long-chain branch is a catalyst, and a catalyst that satisfies CXS may be selected from known catalysts. Specific examples of the catalyst will be described later.

I-5. Characteristic (X-v): Branch index g ^'
Preferably, the polypropylene (X) according to the present invention satisfies the characteristics (X-i) to (X-iv), but more preferably the following characteristics (X-v) are satisfied.
Characteristics (X-v): absolute molecular weight Mabs 1,000,000 in branching index g ^'of 0.3 or more and less than 1.0.

The branching index g ^'is directed to long-chain branching, known as a more direct indication. "Developments in Polymer Characterization-4" (J.V. Dawkins ed. Applied Science Publishers, 1983) to, but there is a detailed description, the definition of branching index g ^', is as follows.
Branch index g ^' = [η] br / [η] lin
[Η] br: Intrinsic viscosity of polymer (br) having a long-chain branched structure [η] lin: Intrinsic viscosity of linear polymer having the same molecular weight as polymer (br)

As apparent from the above definition, the long-chain branched structure is present, branching index g ^'takes a value smaller than 1, the branching index g as long chain branched structure is ^increased' value of, it becomes smaller. Since polypropylene generally has a molecular weight distribution, if a long-chain branched structure is present in a component having a considerably large molecular weight, it can efficiently promote entanglement and contribute to enhancing foaming properties. Thus, among the polypropylene according to the present invention (X), which is the value of the branching index g ^'when the absolute molecular weight Mabs is 1 million are in the specific ranges is particularly preferred.
Absolute molecular weight Mabs are branching index g when made 1 million ^'in order to know the value of the branching index g as a function of absolute molecular weight ^Mabs' must give a value of. Regarding this point, the following measurement method, analysis method, and calculation method shall be used in the present invention.

[Measuring method]
GPC: Alliance GPCV2000 (Waters)
Detector: Listed in connection order Multi-angle laser light scattering detector (MALLS): DAWN-E (Wyatt Technology)
Differential refractometer (RI): GPC attached Viscometer (Viscometer): GPC attached 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 HTs connected Sample injection part temperature: 140 ° C
Column temperature: 140 ° C
Detector temperature: All 140 ° C
Sample concentration: 1 mg / mL
Injection volume (sample loop volume): 0.2175 mL

[analysis method]
Data processing attached to MALLS is used to determine the absolute molecular weight (Mabs) obtained from the multi-angle laser light scattering detector (MALLS), the root mean square radius (Rg), and the limit viscosity ([η]) obtained from the Viscometer. The calculation is performed using the software ASTRA (version 4.73.04) with reference to the following documents.
References:
1. 1. "Developments in Polymer Charactization-4" (JV Dawkins ed. Applied Science Publicers, 1983. Chapter 1.)
2. 2. Polymer, 45, 6495-6505 (2004)
3. 3. Macromolecules, 33, 2424-2436 (2000)
4. Macromolecules, 33, 6945-6952 (2000)

[Calculation method of branch index g']
The branching index g'is the ratio ([η] lin) of the ultimate viscosity ([η] br) obtained by measuring the sample with the above Viscometer and the ultimate viscosity ([η] lin) obtained by separately measuring the linear polymer. Calculated as η] br / [η] lin).
Here, as the linear polymer for obtaining [η] lin, commercially available homopolypropylene (Novatec PP (registered trademark) grade name: FY6 manufactured by Japan Polypropylene Corporation) is used. It is known from the Mark-Houwink-Sakurada equation that the logarithm of [η] lin of a linear polymer has a linear relationship with the logarithm of molecular weight, and [η] lin is on the low molecular weight side or the high molecular weight side. The numerical value will be obtained by extrapolating as appropriate.

Polypropylene according to the present invention (X), the value of the branching index g ^'when the absolute molecular weight Mabs is 100 thousands 0.3 or more and less than 1.0. It is more preferably 0.55 or more and 0.98 or less, still more preferably 0.75 or more and 0.96 or less, and most preferably 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, so that the decrease in physical properties and moldability is small during material recycling in the production process, which is preferable.
As a specific method for adjusting the branching index g'within the above range, selection of a catalyst can be mentioned. The most important factor for determining the branching index g'of polypropylene having long-chain branching 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 elongation viscosity
Preferably, the polypropylene (X) according to the present invention satisfies the above-mentioned characteristics (X-i) to (X-iv), and preferably satisfies the characteristics (X-v), but in addition, the following It is preferable to satisfy the characteristic (X-vi) of.
Characteristic (X-vi): The degree of strain hardening (λmax) in the measurement of elongation viscosity is 5 to 15.

In the calculation of λmax in the present invention, the value of the elongation viscosity measured under the following conditions is used.
Equipment: Ares manufactured by Rheometrics
Jig: Exhibitional Viscosity Fixture manufactured by TA Instruments Co., Ltd.
Measurement temperature: 180 ° C
Strain rate: 0.1 / sec
Test piece preparation method: Press molding Test piece shape: 18 mm x 10 mm, thickness 0.7 mm, sheet

Next, a method of calculating λmax from the obtained elongation viscosity value will be described.
First, the time t (seconds) is plotted on the horizontal axis and the extensional viscosity η _E (Pa · seconds) is plotted on the vertical axis in a log-log graph, and the viscosity immediately before strain curing is approximated by a straight line on the log-log graph. Specifically, the slope at each time when the elongation viscosity is plotted against time is first obtained, but in that case, considering that the measurement data of the elongation viscosity is discrete, the slope of the adjacent data is obtained. , And use the method of taking the moving average of several points around.
The elongation viscosity becomes a simple increasing function in the region of low strain rate, gradually approaches a constant value, and matches the Truton viscosity after a sufficient time without strain hardening, but is common in the case of strain hardening. From about 1 strain amount (= strain rate x time), the elongation viscosity begins 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 amount, and there is an inflection point on the curve when the elongation viscosity is plotted against time. .. Therefore, in the range of the strain amount of about 0.1 to 2.5, find the point where the slope of each time obtained above takes the minimum value, draw a tangent line at that point, and draw a straight line with the strain amount of 4.0. Extrapolate until The maximum value (ηmax) of the extensional viscosity η _E until the strain amount reaches 4.0 is obtained, and the viscosity on the approximate straight line up to that time is defined as ηlin. ηmax / ηlin is defined as λmax (0.1).

The strain hardening degree (λmax) is also recognized as an important factor for foam molding, and many patent documents define the strain hardening degree.
For example, in Patent Document 7, regarding the degree of strain hardening (λmax), in addition to claim 1 of the claims, there is a description of a preferable range in the paragraph [0066], and the higher the value, the more preferable. Is mentioned as 15.0 or higher. Therefore, there is no description in Patent Document 7 that suggests a specific strain hardening degree (λmax) value that is preferable in the present invention, and a relatively low 5 to 15 polypropylene having a long chain branch is preferable. The technical idea of the invention is fundamentally different from that of the invention.
Further, in the above-mentioned Patent Documents 8 and 9, the description regarding the degree of strain hardening (λmax) is described in paragraphs [0061] and [0063], respectively, but the description is the same as that of Patent Document 7, which is preferable in the present invention. There is no description suggesting the value of strain hardening degree (λmax).
Further, Patent Document 12 does not have any suggestion regarding long-chain branched polypropylene having a specific strain hardening degree (λmax) value preferable in the present invention.
Further, also in the case of Patent Document 13, as described in the paragraph [0059], a higher strain hardening degree (λmax) is preferable, and a description suggesting a specific strain hardening degree (λmax) value preferable in the present invention. Is not at all.
Note that Patent Documents 10 and 11 do not have a description about the degree of strain hardening (λmax).

The polypropylene (X) according to the present invention preferably has a strain hardening degree (λmax) of 5 to 15. More preferably, the degree of strain hardening (λmax) is 6 to 14.5, and even more preferably 7 to 14. Among the polypropylenes (X) according to the present invention, those having a strain hardening degree (λmax) within this range are more preferable because the balance between ductility 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 carrying ratio of the complex) and the characteristics (X-iii). There is a method of adjusting the MFR within the range of). Increasing the number of long-chain branches or decreasing the MFR increases the strain hardening degree (λmax). To lower the strain hardening degree (λmax), the strain may be adjusted in the opposite direction.

I-7. Other characteristics (X-vii): mm fraction The characteristics of polypropylene (X) according to the present invention are as described above, but if other characteristics (X-vii) satisfying the following characteristics are used, Even more preferable.
Characteristic (X-vii): ^{13 The} isotactic triad fraction (mm fraction) determined by C-NMR is 95% or more.

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

II. Method for Producing Polypropylene (X) As long as the polypropylene (X) in the present invention satisfies the above-mentioned characteristics (X-i) to (X-iv), the production method is not particularly limited, but as described above. , High stereoregularity, low crystallinity, relatively wide molecular weight distribution, branch index g'range, high melt tension, etc. are all conditions preferred to use a combination of metallocene catalysts. This is a method using the macromer copolymerization method. Examples of such a method include the methods disclosed in JP-A-2009-57542.
In this method, polypropylene having a long-chain branched structure is produced by using a catalyst that combines a catalyst component having a specific structure having a macromer-forming ability and a catalyst component having a specific structure having a macromer copolymerization ability at a high molecular weight. According to this method, an industrially effective method such as bulk polymerization or vapor phase polymerization, particularly practical single-stage polymerization under pressure-temperature conditions, and using hydrogen as a molecular weight modifier. It is possible to produce polypropylene having a long-chain branched structure having the desired physical properties.
Further, conventionally, it has been necessary to increase the branch generation efficiency by reducing the crystallinity by using a polypropylene component having low stereoregularity, but in the above method, a polypropylene component having sufficiently high stereoregularity must be used. (X-iv) and (X), which can be introduced into the side chain by a simple method and have high stereoregularity and low crystallinity, which are preferable as the polypropylene resin (X) used in the present invention. It is suitable for satisfying the characteristics of −v).
Further, by using the above method, the molecular weight distribution can be widened by using two kinds of catalysts having significantly different polymerization characteristics, which is necessary for polypropylene (X) having a long-chain branched structure used in the present invention (X-i). )-(X-iii) can be satisfied at the same time, which is preferable.
Hereinafter, this method will be 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 composed of the following catalyst components (A), (B) and (C).
Catalyst component (A): At least one of the components [A-1] which is a compound represented by the following general formula (a1), and the component [A-2] which is a compound represented by the following general formula (a2). Two or more types of transition metal compounds of Group 4 of the periodic table selected from at least one type.
Component [A-1]: Compound represented by the general formula (a1) Component [A-2]: Compound catalyst component represented by the general formula (a2) (B): Ion-exchangeable layered silicate catalyst component (C) ): Organoaluminium 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 the general formula (a1)

[In the general formula (a1), R ¹¹ and R ¹² , respectively, independently represent a heterocyclic group containing nitrogen, oxygen or sulfur having 4 to 16 carbon atoms. R ¹³ and R ^14, respectively, are aryl groups having 6 to 16 carbon atoms, which may independently 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 are independently hydrogen atom, halogen atom, hydrocarbon group having 1 to 20 carbon atoms, silicon-containing hydrocarbon group having 1 to 20 carbon atoms, and halogenated hydrocarbon group having 1 to 20 carbon atoms, respectively. Group, oxygen-containing hydrocarbon group with 1 to 20 carbon atoms, amino group, nitrogen-containing hydrocarbon group with 1 to 20 carbon atoms, alkoxy group with 1 to 20 carbon atoms, alkylamide group with 1 to 20 carbon atoms, trifluoromethane Represents a sulfonic acid group or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms. Q ¹¹ represents a divalent hydrocarbon group or a hydrocarbon group which may have a silylene group or a germylene group having 1 to 20 carbon atoms, having 1 to 20 carbon atoms. ]

The heterocyclic group of R ¹¹ and R ¹² containing nitrogen, oxygen or sulfur having 4 to 16 carbon atoms 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.
Further, as the substituent of the substituted 2-furyl group, the substituted 2-thienyl group and the 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 can be used. Examples thereof include a halogen atom such as a fluorine atom and a chlorine atom, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group, and a trialkylsilyl group. Of these, a methyl group and a trimethylsilyl group are preferable, and a methyl group is more preferable.
In addition, R ¹¹ and R ¹² are particularly preferably 2- (5-methyl) -frill groups. Further, it is preferable that R ¹¹ and R ¹² are 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 hetero elements selected from these, carbon is used in R ¹³ and R ^14. In the range of the number 6 to 16, one or more hydrocarbon groups having 1 to 6 carbon atoms, silicon-containing hydrocarbon groups having 1 to 6 carbon atoms, and halogens having 1 to 6 carbon atoms are contained on the aryl cyclic skeleton. It may have a hydrocarbon group or the like as a substituent.

As R ¹³ and R ¹⁴ , preferably at least one is a phenyl group, a 4-methylphenyl group, a 4-i-propylphenyl group, a 4-t-butylphenyl group, a 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 as each other.

In the general formula (a1), X ¹¹ and Y ¹¹ are co-ligands and react with the catalyst component (B) to produce an active metallocene having an 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 hydrogen atoms, halogen atoms, and hydrocarbon groups having 1 to 20 carbon atoms. , Silicon-containing hydrocarbon groups with 1 to 20 carbon atoms, halogenated hydrocarbon groups with 1 to 20 carbon atoms, oxygen-containing hydrocarbon groups with 1 to 20 carbon atoms, amino groups or nitrogen-containing hydrocarbon groups with 1 to 20 carbon atoms. A 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 is shown.

In the general formula (a1), Q ¹¹ is a bonding group for cross-linking two conjugated five-membered ring, a divalent hydrocarbon group, or a hydrocarbon group having 1 to 20 carbon atoms having 1 to 20 carbon atoms Indicates either a acylene group or a gelmilene group which may be possessed. When two hydrocarbon groups are present on the silylene group or the gelmilene group described above, they may be bonded to each other to form a ring structure.
Specific examples of the above Q ^11, methylene, methylmethylene, dimethylmethylene, alkylene group of 1,2-ethylene and the like; silylene group; arylalkylene groups such as diphenylmethylene methylsilylene, dimethylsilylene, diethyl silylene, di ( Alkyl silylene groups such as n-propyl) silylene, di (i-propyl) silylene, di (cyclohexyl) silylene, (alkyl) (aryl) silylene groups such as methyl (phenyl) silylene; aryl silylene groups such as diphenyl silylene; tetra Alkyloligosilylene group such as methyldisyrylene; Germilene group; Alkyl gelmilene group in which silicon of the silylene group having a divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl) (aryl) gelmilene Group: An arylgelmilene group and the like can be mentioned. Among these, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms or a gelmilene group having a hydrocarbon group having 1 to 20 carbon atoms is preferable, and an alkylsilylene group and an alkyl gelmilene group are more preferable.

Among 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'-dimethylgermilenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl} ] Hafnium, dichloro [1,1'-dimethylgelmilenebis {2- (5-methyl-2-thienyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-( 5-t-Butyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-trimethylsilyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-phenyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (4,4) 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) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl) -2-Frill) -4- (4-i-propylphenyl) -Indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4- (4-) Methylsilylphenyl) -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) -Inde Nil}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trifluoromethylphenyl) -indenyl}] hafnium, dichloro [1,1' -Dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-t-butylphenyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) ) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1 , 1'-dimethylsilylenebis {2- (2-furyl) -4- (2-phenanthryl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) -4- (9-Phenanceril) -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-Frill) -4- (2-Phenanthrill) -Indenyl}] Hafnium, Dichloro [1,1'-dimethylsilylenebis {2- (5-Methyl-2-frill) -4- (9-Phenanthrill)- Indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1'- Dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl) -2-Frill) -4- (2-Phenanthrill) -Indenyl}] Hafnium, Dichloro [1,1'-Dimethylsilylenebis {2- (5-t-Butyl-2-Frill) -4- (9-Phenanthrill) ) -Indenyl}] Hafnium, etc.

Of these, more preferred are dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1'-dimethylsilylene. Bis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-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-t-Butylphenyl) -indenyl}] hafnium ,.
Further preferred are dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] naphthium, 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 the general formula (a2)

[In the general formula (a2), R ²¹ and R ²² , respectively, independently represent a hydrocarbon group having 1 to 6 carbon atoms. Each of R ²³ and R ²⁴ is an aryl group having 6 to 16 carbon atoms which may independently contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus or a plurality of hetero elements selected from these. is there. X ²¹ and Y ²¹ independently have 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, and a halogenated hydrocarbon having 1 to 20 carbon atoms. group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group or a nitrogen-containing hydrocarbon group having a carbon number of 1 to 20, Q ²¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms or carbon, Represents a silylene group or a gelmilene group which may have a hydrocarbon group of several 1 to 20. M ²¹ is zirconium or hafnium. ]

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

The R ²³ and R ²⁴ may each independently contain a halogen, silicon, or a plurality of heteroelements selected from these, which have 6 to 16 carbon atoms, preferably 6 to 12 carbon atoms. It is an aryl group. Preferred examples are phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4- (2-Fluoro-4-biphenylyl), 4- (2-chloro-4-biphenylyl), 1-naphthyl, 2-naphthyl, 4-chloro-2-naphthyl, 3-methyl-4-trimethylsilylphenyl, 3,5 Examples thereof include −dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl, 3,5-dichloro-4-trimethylsilylphenyl and the like.

The X ²¹ and Y ²¹ are auxiliary ligands and react with the catalyst component (B) to produce an active metallocene having an olefin polymerization ability. Therefore, as long as this purpose is achieved, X ²¹ and Y ²¹ are not limited in the type of ligand, and are independently hydrogen atoms, halogen atoms, and hydrocarbon groups having 1 to 20 carbon atoms. , Silicon-containing hydrocarbon groups with 1 to 20 carbon atoms, halogenated hydrocarbon groups with 1 to 20 carbon atoms, oxygen-containing hydrocarbon groups with 1 to 20 carbon atoms, amino groups or nitrogen-containing hydrocarbon groups with 1 to 20 carbon atoms. A group, an alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, and a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms are shown.

The above Q ²¹ is a bonding 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. Indicates a acylene group or a gelmilene group. When two hydrocarbon groups are present on the silylene group or the gelmilene group, they may be bonded to each other to form a ring structure. It is preferably a substituted silylene group or a substituted gelmilene group.

The substituent bonded to silicon or germanium is preferably a hydrocarbon group having 1 to 12 carbon atoms, and the two substituents may be linked. Specific examples include methylene, dimethylmethylene, ethylene-1,2-diyl, dimethylsilylene, diethylsilylene, diphenylcilylene, methylphenylcilylene, 9-silafluorene-9,9-diyl, dimethylsilylene, diethylsilylene, Examples thereof include diphenylsilylene, methylphenylsilylene, 9-silafluorene-9,9-diyl, dimethylgelmilene, diethyl gelmilene, diphenylgelmilene and methylphenylgelmilene.

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

The following can be mentioned as non-limiting examples of the metallocene compound represented by the above general formula (a2).
However, the following describes only representative exemplary compounds, avoiding a large number of complicated examples, and the present invention is not construed as being limited to these compounds, and various ligands, cross-linking groups, or auxiliary coordinations are described. It is self-evident that the child can be used arbitrarily.
Further, although the compound in which the central metal is hafnium is described, the compound in place of zirconium is also treated as disclosed in the present specification.

Dichloro {1,1'-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazurenyl)} hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4 -Hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis { 2-Methyl-4- (4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chloro-4-t-butylphenyl)- 4-Hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl-4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1' -Dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl) -4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (1-naphthyl) -4-hydroazulenyl}] hafnium, dichloro [1,1' -Dimethylsilylenebis {2-methyl-4- (2-naphthyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethyl Silyrenbis {2-methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (9-phenanthril) -4 -Hydroazulenyl}] 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 Nium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis { 2-Ethyl-4- (3-Methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylgermilenebis {2-methyl-4- (2-fluoro-4-biphenylyl) ) -4-Hydroazurenyl}] hafnium, dichloro [1,1'-dimethylgelmilenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'- (9-Silafluorene-9,9-diyl) Bis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-Chloro-2-naphthyl) -4-hydroazulenyl}] 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, etc. Can be mentioned.

Of these, more preferred are dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] 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-hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-chloro-2-naphthyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethyl Sirilenbis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-(9-silafluorene-9,9-diyl) bis {2- Ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium.

Further preferred are dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- Ethyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloromethane [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-hydroazulenyl} ] Hafnium.

(2) Catalyst component (B)
The catalyst component (B) preferably used for producing the polypropylene resin (X) is an ion-exchangeable layered silicate.
(I) Types of ion-exchangeable layered silicates With ion-exchangeable layered silicates (hereinafter, may be simply abbreviated as silicates), surfaces formed by ion bonds and the like are stacked in parallel with each other due to bonding force. A silicate compound having a crystal structure and having exchangeable ions contained therein. Since most silicates are naturally produced mainly as the main component of clay minerals, they often contain impurities (quartz, cristobalite, etc.) other than ion-exchange layered silicates, but they are included. It may be. Depending on the type, amount, particle size, crystallinity, and dispersed state of these impurities, it may be preferable to pure silicate or higher, and such a complex is also included in the catalyst component (B).
The silicate used in the present invention is not limited to naturally produced ones, and may be artificial synthetic compounds or may contain them.

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

(Ii) Chemical Treatment of Ion-Exchangeable Layered Silicate The ion-exchangeable layered silicate of the catalyst component (B) according to the present invention can be used as it is without any special treatment, but it is preferable to carry out chemical treatment. .. Here, as the chemical treatment of the ion-exchangeable layered silicate, either a surface treatment for removing impurities adhering to the surface or a treatment for affecting the structure of clay can be used, and specifically, an acid. Examples include treatment, alkali treatment, salt treatment, and organic substance treatment.

<Acid treatment>:
The acid treatment can remove impurities on the surface and elute some or all of the cations such as Al, Fe, and Mg in the 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.
The number of salts (described in the next section) and acids used in the treatment may be two or more. The treatment conditions with salts and acids are not particularly limited, but 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 preferably carried out under the condition that at least a part of the substance constituting at least one compound selected from the group consisting of ion-exchangeable layered silicates is eluted. In addition, salts and acids are generally used in aqueous solutions.
A combination of the following acids and salts may be used as the treatment agent. Further, it may be a combination of these acids and salts.

<Salt treatment>:
40% or more, preferably 60% or more of the exchangeable metal cations contained in the ion-exchangeable layered silicate before being treated with salts should be ion-exchanged with the cations dissociated from the salts shown below. Is preferable.
The salts used in the salt treatment for the purpose of such ion exchange consist of at least one cation selected from the group consisting of organic cations, inorganic cations and metal ions, and organic anions and inorganic anions. Salts composed of at least one anion selected from the group are exemplified. For example, at least selected from the group consisting of cations containing at least one atom selected from the group consisting of group 1 to 14 atoms in the periodic table, halogen anions, and anions derived from inorganic and organic acids. A compound composed of a kind of anion is a preferable example. Here, the acid-derived anion 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, NO ₃ ^- is and, in the case of a trivalent inorganic acids such as H ₃ PO _4, the acid derived ^{_{anions, H 2 PO 4 -, HPO}} 4 2-, PO 4 3-, 3 kinds are present. The same applies to anions derived from organic acids. More preferably, the cation is a compound composed of a metal ion and the anion is an anion derived from an inorganic acid or a halogen anion.

Specific examples of such salts include 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, Examples thereof include Mg (NO ₃ ) ₂ and Mg (CH ₃ COO) ₂ .

In addition, 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.

In addition, 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 can be mentioned.

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

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

In addition, these treatment agents may be used alone or in combination of two or more. 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 in the middle of the treatment. Further, the chemical treatment can be performed a plurality of times using the same or different treatment agents.
These ion-exchangeable layered silicates usually include adsorbed water and interlayer water. It is preferable to remove these adsorbed water and interlayer water and use it as the catalyst component (B).

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

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

The ion-exchangeable layered silicate can be treated with the catalyst component (C) of the organoaluminum compound described later before forming a catalyst or using it as a catalyst, which is preferable. The amount of the catalyst component (C) used with respect to 1 g of the ion-exchangeable layered silicate is not limited, but is usually 20 mmol or less, preferably 0.5 mmol or more and 10 mmol or less. There is no limitation on the treatment temperature and time, and the treatment temperature is usually 0 ° C. or higher and 70 ° C. or lower, and the treatment time is 10 minutes or longer and 3 hours or shorter. It is also possible and preferable to wash after the treatment. As the solvent, a hydrocarbon solvent similar to the solvent used in the prepolymerization or slurry polymerization described later is used.

Further, as the catalyst component (B), it is preferable to use spherical particles having an average particle size of 5 μm or more. As long as the shape of the particles is spherical, a natural product or a commercially available product may be used as it is, or a particle whose shape and particle size are controlled by granulation, fragmentation, separation or the like may be used.
Examples of the granulation method used here include a stirring granulation method and a spray granulation method, but commercially available products can also be used.
In addition, an organic substance, an inorganic solvent, an inorganic salt, and various binders may be used for granulation.
The spherical particles obtained as described above preferably have a compressive fracture strength of 0.2 MPa or more, particularly preferably 0.5 MPa or more, in order to suppress crushing and formation of fine powder in the polymerization step. 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. As the organoaluminum compound used as the catalyst component (C), a compound represented by the general formula: (AlR ³¹ _q Z _3-q ) _p is suitable. The compounds represented by this formula can be used alone, in combination of two or more, or in combination. In this formula, R ³¹ represents a hydrocarbon group having 1 to 20 carbon atoms, and Z represents a halogen, hydrogen, alkoxy group, or amino group. q represents an integer of 1 to 3 and p represents an integer of 1 to 2. As R ³¹ , an alkyl group is preferable, and Z is chlorine when it is a halogen, an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and 1 to 8 carbon atoms when it is an amino group. An amino group of 8 is preferred.

Specific examples of the organic aluminum 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, diisobutylaluminum chloride and the like.
Of these, trialkylaluminum or alkylaluminum hydride with p = 1 and q = 3 is preferred. More preferably, it is trialkylaluminum in which R ³¹ has 1 to 8 carbon atoms.

(4) Formation / Prepolymerization of Catalyst The catalyst brings the above catalyst components (A) to (C) into contact with each other in the (preliminary) polymerization tank simultaneously or continuously, or at one time or multiple times. Can be formed by.
Contact of each component is usually carried out in an aliphatic hydrocarbon or aromatic hydrocarbon solvent. The contact temperature is not particularly limited, but is preferably between −20 ° C. and 150 ° C. As the contact order, any combination for the purpose is possible, and a particularly preferable one is as follows for each component.
Before the catalyst component (A) and the catalyst component (B) are brought into contact with each other, the catalyst component (A), or the catalyst component (B), or both the catalyst component (A) and the catalyst component (B) are subjected to the catalyst component ( The catalyst component (A) and the catalyst component (B) are brought into contact with each other, or the catalyst component (C) is brought into contact with the catalyst component (C) at the same time, or the catalyst component (A) and the catalyst component (B) are brought into contact with each other. It is possible to bring the catalyst component (C) into contact after the contact, but preferably, the catalyst component (A) and the catalyst component (B) are brought into contact with any of the catalyst components (C) before being brought into contact with each other. The method.
Further, after contacting each component, it is possible to wash with an aliphatic hydrocarbon or an aromatic hydrocarbon solvent.

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

The ratio of the component [A-1] (compound represented by the general formula (a1)) used in the present invention to the component [A-2] (compound represented by the general formula (a1)) is propylene-based. The molar ratio of the transition metal of [A-1] to the total amount of each component [A-1] and [A-2] is preferably 0.30 or more, although it is arbitrary as long as it satisfies the above-mentioned characteristics of the polymer. , 0.99 or less.
By changing this ratio, it is possible to adjust the balance between melt properties and catalytic activity. That is, a low molecular weight terminal vinyl macromer is produced from the component [A-1], and a high molecular weight body obtained by partially copolymerizing the macromer is produced from the component [A-2]. Therefore, by changing the ratio of the component [A-1], the average molecular weight, the molecular weight distribution, the bias of the molecular weight distribution toward the high molecular weight side, the very high molecular weight component, the branch (amount, length, Distribution) can be controlled, thereby controlling the melt properties such as strain hardening degree, melt tension, and melt ductility.

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

The catalyst according to the present invention is subjected to a prepolymerization treatment consisting of bringing an olefin into contact with the catalyst and polymerizing the catalyst in a small amount. By performing the prepolymerization treatment, it is possible to prevent the formation of a gel when the main polymerization is performed. It is considered that the reason is that the long-chain branches can be uniformly distributed among the polymer particles when the main polymerization is carried out, and thereby the melt property can be improved.

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

Further, it is also possible to allow a polymer such as polyethylene or polypropylene or a solid of an inorganic oxide such as silica or titania to coexist at the time of or after the contact of each of the above components.

II-2. Polymerization method (1) Use of catalyst / Propylene polymerization The polymerization mode is such that the olefin polymerization catalyst containing the catalyst component (A), the catalyst component (B) and the catalyst component (C) and the monomer are in efficient contact with each other. Any style can be adopted.
Specifically, a slurry polymerization method using an inert solvent, a so-called bulk polymerization method in which propylene is used as a solvent without substantially using an inert solvent, a solution polymerization method, or a gas of each monomer substantially without using a liquid solvent. A vapor phase polymerization method or the like that keeps the shape can be adopted. Further, a method of performing continuous polymerization or batch polymerization is also applied. In addition to single-stage polymerization, multi-stage polymerization of two or more stages is also possible.
In the case of the slurry polymerization method, a single or a mixture of saturated aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene and toluene is used as the polymerization solvent.

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

Further, when gas phase polymerization is used, it is preferably 1.5 MPa or more, more preferably 1.7 MPa or more. The upper limit is preferably 2.5 MPa or less, more preferably 2.3 MPa or less.
Furthermore, hydrogen can be used as a molecular weight modifier and as an auxiliary agent in the range of 1.0 × ^10-6 or more and 1.0 × ^10-2 or less in terms of molar ratio with respect to propylene. it can.

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

In addition to the propylene monomer, copolymerization may be carried out using an α-olefin comonomer having 2 to 20 carbon atoms excluding propylene, for example, ethylene and / or 1-butene as the comonomer, depending on the intended use.
Therefore, in order to obtain a polypropylene (X) used in the present invention having a good balance between catalytic activity and melt properties, ethylene and / or 1-butene may be used in an amount of 15 mol% or less based on propylene. It is preferable, more preferably 10.0 mol% or less, and further preferably 7.0 mol% or less.

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

III. Number of Gels In the polypropylene resin composition for foam molding according to the present invention, the number of gels having a major axis of 0.5 mm or more is 50 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used. Preferably, when a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.5 mm or more is 50 pieces / m ² or less, and the number of gels having a major axis of 0.4 mm or more and less than 0.5 mm is 400 pieces / m. It is ² or less. More preferably, when a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.5 mm or more is 50 / m ² or less, and the number of gels having a major axis of 0.4 mm or more and less than 0.5 mm is 400 / m ^2. m ² or less, the number of gels less than the major diameter 0.3 mm 0.4 mm is 2000 / ^{m 2} or less.

In the polypropylene resin for foam molding according to the present invention, the number of gels having a major axis of 0.5 mm or more is 10 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used. Preferably, when a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.5 mm or more is 10 pieces / m ² or less, and the number of gels having a major axis of 0.2 mm or more and less than 0.5 mm is 50 pieces / m. It is ² or less. More preferably, when a non-stretched film having a thickness of 25 μm is used, the number of gels having a major axis of 0.5 mm or more is 10 / m ² or less, and the number of gels having a major axis of 0.2 mm or more and less than 0.5 mm is 50 / m ^2. m ² or less, the number of gels less than the major diameter 0.1 mm 0.2 mm is 100 / ^{m 2} or less.

The non-stretched film can be produced by a conventional film molding apparatus using a polypropylene resin for foam molding, a polypropylene resin composition for foam molding, or other samples. For example, a sample can be produced by throwing it into a conventional extruder equipped with a T-die, extruding it under appropriate conditions, and then taking it up with a conventional film picker. The number of gels in the produced non-stretched film can be counted by a conventional defect detector. It is convenient to count the number of gels at the center of the film, between the picker and the winder. It is recommended to set the inspection width, inspection length and number of inspections as appropriate, and calculate by converting the average value of the values obtained for each size category into unit area. Details will be described in the following examples.

IV. Polypropylene resin for foam molding made of polypropylene (X) As described above, the polypropylene resin for foam molding of the present invention has a melt tension (230 ° C.) of 3 g or more and is in a predetermined range when it is a non-stretched film having a thickness of 25 μm. It is made of polypropylene (X) having a major axis number of gels of a predetermined number or less per unit area. And preferably, polypropylene (X) satisfies the above-mentioned characteristics (X-i) to (X-iv). Additives, foaming agents, extrusion foam molding, foam sheets, multi-layer foam sheets, thermoformability, molded products, uses and the like will be described in the section of the following description of the polypropylene resin composition for foam molding.

V. Propylene block copolymer (Y)
The component (Y) blended with the polypropylene (X) having the long-chain branched structure described above is not particularly limited, but is a propylene (co) polymer (Y-1) and a propylene-ethylene copolymer (Y-2). ), It is preferable to use a propylene-based block copolymer (Y). More preferably, it is produced by performing multi-step polymerization by a conventionally known sequential polymerization method.
The term block copolymer used here is different from the so-called (real) block copolymer or graft copolymer in which the components polymerized at each stage are bonded by chemical bonds. Since the components produced in each step of multi-step polymerization are not chemically bonded, in general, crystalline separation is performed by utilizing the difference in crystallinity, molecular weight, solubility in a solvent, etc. of each component. It is possible to separate each of the components produced in each step by a method such as molecular weight separation or solubility separation.
Further, in the conventionally known block copolymer (Y) by the sequential polymerization method, the existence of a long-chain branched structure by a chemical bond such as polypropylene (X) is not recognized with analyzable accuracy.

1. 1. Method for Producing propylene Block Copolymer (Y), Polymerization Catalyst Any catalyst for producing the propylene block copolymer (Y) can be used, but the following characteristics (Y-i) When a propylene-ethylene copolymer (Y-2) satisfying (Yv) is produced as a constituent component, it is preferable to use a Ziegler-Natta catalyst. When a Ziegler-Natta catalyst is used, the specific method for producing the catalyst is not particularly limited, but as an example, the catalyst disclosed in JP-A-2007-254671 can be exemplified.
Specifically, as a typical example of the Ziegler-Natta catalyst suitable for producing the propylene-based block copolymer (Y) of the present invention, the following constituent components,
(ZN-1) A solid component containing titanium, magnesium, and halogen as essential components,
(ZN-2) Organoaluminium compound,
(ZN-3) Electron donor,
A catalyst consisting of

(1) Solid component (ZN-1)
The solid component (ZN-1) that is a component of the Ziegler-Natta catalyst suitable for producing the propylene-based block copolymer (Y) of the present invention is titanium (ZN-1a), magnesium (ZN-1b), or 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 contained in any form as long as the effects of the present invention are not impaired, in addition to the three components shown. .. It will be described in detail below.

(ZN-1a) Titanium Any titanium compound can be used as a titanium source. As a typical example, the compound disclosed in JP-A-3-234707 can be mentioned. Regarding the valence of titanium, a titanium compound having an arbitrary valence of tetravalence, trivalent, divalent or 0 valence can be used, but it is desirable to use a tetravalent titanium compound.

(ZN-1b) Magnesium Any magnesium compound can be used as a magnesium source. As a typical example, a compound disclosed in JP-A-234707 can be mentioned. 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 preferable.

(ZN-1d) Electron Donor The solid component (ZN-1) may contain an electron donor as an optional component. A typical example of the electron donor (ZN-1d) is a compound disclosed in JP-A-2004-124090. In general, organic and inorganic acids, and their derivatives (esters, acid anhydrides, acid halides, amides) compounds, ether compounds, ketone compounds, aldehyde compounds, alcohol compounds, amine compounds, etc. It is desirable to use.
Of these, preferred are dibutyl phthalate, dibutyl phthalate, diisobutyl phthalate, phthalate ester compounds typified by diheptyl phthalate, phthalate halide compounds typified by phthaloyl dichloride, 2-n-. Malonate compounds having one or two substituents at the 2-position such as diethyl butyl-malonate, one or two substituents or 2 at the 2-position such as diethyl 2-n-butyl-succinate Of succinate compounds having one or more substituents at the positions and 3-positions, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane. Free of aliphatic polyvalent ether compounds typified by 1,3-dimethoxypropane and aromatics typified by 9,9-bis (methoxymethyl) fluorene having one or two substituents at such 2-positions. Polyvalent ether compounds having a group in the molecule, and the like.

(2) Organoaluminium compound (ZN-2)
As the organoaluminum compound (ZN-2), a compound disclosed in JP-A-2004-124090 can be used. In general, it is desirable to use a compound represented by the following general formula (5).
R ⁹ cAlXd (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, methylalmoxane, and the like.

(3) Electron donor (ZN-3)
As the electron donor (ZN-3), an organosilicon compound having an alkoxy group (ZN-3a) or a compound having at least two ether bonds (ZN-3b) can be exemplified.

(ZN-3a) Organosilicon compound having an alkoxy group An organosilicon compound (ZN-3a) having an alkoxy group which is a constituent component of a Ziegler-Natta catalyst suitable for producing the propylene-based block copolymer (Y) according to the present invention. ) Can be a compound or the like disclosed in JP-A-2004-124090. In general, it is desirable to use a compound represented by the following general formula (3).
R ³ R ⁴ aSi (OR ⁵ ) b ... (3)
(In the general formula (3), R ³ represents a hydrocarbon group or a hetero atom-containing hydrocarbon group. R ⁴ is selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group and a hetero atom-containing hydrocarbon group. R ⁵ represents a hydrocarbon group. 0 ≦ a ≦ 2, 1 ≦ b ≦ 3, a + b = 3.

As a specific example, 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 can be mentioned.

(ZN-3b) Compound having at least two ether bonds Examples of the compound having at least two ether bonds (ZN-3b) include compounds disclosed in JP-A-3-294302 and JP-A-8-333413. Can be used. In general, it is desirable to use a compound represented by the following general formula (4).
R ⁸ OC (R ⁷ ) _2- C (R ⁶ ) _2- C (R ⁷ ) _2- OR ⁸ ... (4)
(In the 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 hetero atom-containing hydrocarbon group. R ⁸ represents a hydrocarbon group or a hetero. Represents an atomic-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 Examples thereof include -2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, and 9,9-bis (methoxymethyl) fluorene.

(4) Prepolymerization The catalyst exemplified above may be prepolymerized before being used in the main polymerization. By forming a small amount of polymer around the catalyst in advance prior to the polymerization process, the catalyst becomes more uniform and the amount of fine powder generated can be suppressed.
As the monomer in the prepolymerization, a compound or the like disclosed in JP-A-2004-124090 can be used. Specifically, ethylene, propylene, 3-methylbutene-1, 4-methylpentene-1, styrene, divinylbenzene, and the like are particularly preferable.
The reaction conditions between the catalyst exemplified above and the above-mentioned monomer are not particularly limited, but are generally preferably within the following ranges.
On the basis of 1 g of the solid component (ZN-1), the prepolymerization amount is in the range of 0.001 to 100 g, preferably 0.1 to 50 g, and more preferably 0.5 to 10 g. The reaction temperature during prepolymerization is −150 to 150 ° C., preferably 0 to 100 ° C. Then, it is desirable that the reaction temperature at the time of prepolymerization is lower than the polymerization temperature at the time of main polymerization. The reaction is generally preferably carried out under stirring, and an inert solvent such as hexane or heptane may be present at that time.

(5) Step-growth polymerization Next, the method for producing the propylene-based block copolymer (Y) of the present invention will be described in detail.
The propylene-based block copolymer (Y) of the present invention is preferably a propylene-ethylene copolymer composed of a propylene (co) copolymer (Y-1) and a propylene-ethylene copolymer (Y-2). In the production of such a propylene-based block copolymer (Y), two polymer components, a propylene (co) copolymer (Y-1) and a propylene-ethylene copolymer (Y-2), are produced. There is a need. A propylene-ethylene copolymer (Y-2) having a relatively high molecular weight and a low viscosity and MFR is neatly dispersed in a propylene (co) polymer (Y-1) to form a propylene block copolymer (Y) originally. From the viewpoint of exhibiting the performance of the above, it is necessary to produce both of the components by sequential polymerization.

Specifically, it is desirable to polymerize the propylene (co) copolymer (Y-1) in the first step and then polymerize the propylene-ethylene copolymer (Y-2) in the second step. Although it is possible to reverse the production order, the propylene-ethylene copolymer (Y-2) has an ethylene content of 11.0% by weight or more in the copolymer according to the specification of (Y-iv). Since the polymer is in the range of less than 0.0% by weight and has low crystallinity, if it is manufactured in the first step, it may cause manufacturing troubles such as adhesion inside the polymerization tank or blockage of the transfer pipe. High and not very desirable.
When performing step-growth polymerization, either the batch method or the continuous method can be used, but it is generally desirable to use the continuous method from the viewpoint of productivity.
In the case of the batch method, the propylene (co) polymer (Y-1) and the propylene-ethylene copolymer (Y-2) are individually separated by using a single polymerization reactor by changing the polymerization conditions with time. It is possible to polymerize to. A plurality of polymerization reactors may be connected in parallel and used as long as the effects of the present invention are not impaired.
In the case of the continuous method, it is necessary to polymerize the propylene (co) polymer (Y-1) and the propylene-ethylene copolymer (Y-2) individually, so that two or more polymerization reactors are connected in series. It is necessary to use equipment. Regarding the polymerization reactor corresponding to the first step of producing the propylene (co) polymer (Y-1) and the polymerization reactor corresponding to the second step of producing the propylene-ethylene copolymer (Y-2), Although it must be in series, a plurality of polymerization reactors may be connected in series and / or in parallel for each of the first step and the second step.

(6) Polymerization process Any polymerization process can be used.
As for the reaction phase, a method using a liquid medium or a method using a gas medium may be used. Specific examples include the slurry method, the bulk method, and the vapor phase method. It is possible to use supercritical conditions as intermediate conditions between the bulk method and the gas phase method, but since they are substantially the same as the gas phase method, they are included in the gas phase method without any particular distinction. In the case of a multi-tank continuous polymerization process, a vapor phase polymerization reactor may be attached after the bulk method polymerization reactor. In this case, the bulk method will be referred to according to the custom of the art. Further, in the case of the batch method, the first step may be carried out by the bulk method and the second step may be carried out by the vapor phase method. In this case as well, the bulk method is used. As described above, the reaction phase is not particularly limited, but the slurry method has a problem that the production cost is generally high because many auxiliary equipments are used because an organic solvent such as hexane or heptane is used. Therefore, it is more desirable to use the bulk method or the vapor phase method.
In addition, various processes have been proposed for the bulk method and the gas phase method. Although there are differences in the stirring (mixing) method and the heat removal method, the present invention does not particularly limit the process species from this viewpoint.

(7) General Polymerization Conditions The polymerization temperature can be used without any particular problem as long as it is in the normally used temperature range. Specifically, a range of 0 ° C. to 200 ° C., preferably 40 ° C. to 100 ° C. can be used.
The polymerization pressure varies depending on the selected process, but can be used without any problem as long as it is in the normally used pressure range. Specifically, a range larger than 0 and up 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.
Further, in the second step of producing the propylene-ethylene copolymer (Y-2), a polymerization inhibitor such as ethanol or oxygen can be added. When such a polymerization inhibitor is used, not only the amount of polymerization in the second step can be easily controlled, but also the properties of the polymer particles can be improved.

(Y-1) produced in the first stage of the step-growth polymerization is a propylene homopolymer or a propylene random copolymer obtained by copolymerizing a small amount of comonomer within the range not deviating from the gist of the present invention. As the comonomer, α-olefins having up to about 10 carbon atoms excluding 3 such as ethylene, butene, and hexene are usually used.
The content of the comonomer is not particularly limited, but is preferably 10 wt% or less, more preferably 3 wt% or less, and particularly preferably 1 wt% or less. The control of the comonomer content is usually performed by appropriately adjusting the amount ratio of the monomer supplied to the polymerization tank (eg, the amount ratio of ethylene to propylene). The copolymerization characteristics of the catalyst to be used may be investigated in advance, and the supply amount ratio of the monomers may be adjusted so that the gas composition of the polymerization tank becomes a value corresponding to the desired comonomer content.

2. 2. Characteristics of Propylene Block Copolymer (Y) As a result of many experimental studies, the present inventors have found that the propylene block copolymer (Y) to be blended in the polypropylene resin (X) is as follows (Y-i )-(Yv), it has been found that the formation of the structure formed by the polypropylene (X) having the long-chain branched structure under the shear flow can be suppressed. It will be described in detail below.

2-1. Characteristic (Y-i): Amount ratio of (Y-1) and (Y-2) The weight ratio of (Y-1) and (Y-2) recommended in the present invention is 50 for (Y-1). It is ~ 99 wt%, preferably 55 to 97 wt%, and more preferably 60 to 95 wt%. Correspondingly, (Y-2) is 1 to 50 wt%, preferably 3 to 45 wt%, and more preferably 5 to 40 wt%.
(However, regarding the weight ratios of (Y-1) and (Y-2), the total amount of the propylene-based block copolymer (Y) is 100 wt%).

By blending this propylene-based block copolymer (Y) with polypropylene (X) having a long-chain branched structure, good ductility is imparted, and various types are obtained as compared with the case where the component (X) is used alone. Advantages such as widening the temperature range in which molding can be performed by the molding method of the above, improving the appearance, and improving mechanical properties such as impact characteristics can be obtained. When the amount of the component (Y-2) is set to be equal to or higher than the lower limit of the above range, these merits can be easily obtained, while when the amount is set to be equal to or lower than the upper limit of the above range, the amount of the crystalline component (Y-1) is set. Can be maintained high, and the heat resistance and rigidity of the composition can be kept good.
The weight ratio of the propylene (co) polymer (Y-1) and the propylene-ethylene copolymer (Y-2) is the amount produced in the first step of producing the propylene (co) polymer (Y-1) and propylene. -Controlled by the production amount in the second step of producing the ethylene copolymer (Y-2). For example, in order to increase the amount of the propylene (co) polymer (Y-1) and decrease the amount of the propylene-ethylene copolymer (Y-2), the second step is performed while maintaining the production amount of the first step. It is only necessary to reduce the production amount of the above, which may shorten the residence time of the second step or lower the polymerization temperature. It can also be controlled by adding a polymerization inhibitor such as ethanol or oxygen, or, if originally added, increasing the amount of the addition. The reverse is also true.

2-2. Characteristic (Y-ii): MFR
The recommended range of MFR for the propylene-based block copolymer (Y) used in the present invention is in the range of 0.1 to 200 g / 10 minutes, preferably 0.2 to 190 g / 10 minutes, and more preferably 0.2 to 190 g / 10 minutes. It is in the range of 0.5 to 180 g / 10 minutes, particularly preferably 2.1 to 170 g / 10 minutes.
This is a normal range as the range of MFR of the resin used for various moldings, and by setting it above the lower limit of this range, the load of the extruder can be properly maintained and the flow of the resin can be kept stable. By setting it below the upper limit, the neck-in during extrusion molding can be reduced and the sheet can be easily picked up.
The method for measuring MFR is the same as the method for measuring polypropylene (X) described above.
Next, a method for controlling the MFR of the propylene-based block copolymer (Y) will be described. Regarding the MFR (Y) of the propylene-based block copolymer (Y), the MFR (Y-1) of the propylene (co) polymer (Y-1) and the MFR of the propylene-ethylene copolymer (Y-2) ( The following relational expression holds with Y-2).
loge [MFR (Y)] = W (Y-1) x loge [MFR (Y-1)] + W (Y-2) x loge [MFR (Y-2)]
(Here, loge is a logarithm with e as the base. Further, W (Y-1) and W (Y-2) are propylene (co) copolymers in the propylene block copolymer (Y), respectively. It is the weight ratio of (Y-1) and the propylene-ethylene copolymer (Y-2), and the relationship of W (Y-1) + W (Y-2) = 1 is established.)

This empirical formula is an empirical formula called the logarithmic addition law of viscosity and is used daily in the industry. That is, the weight ratio of the propylene (co) polymer (Y-1) and the propylene-ethylene copolymer (Y-2), MFR (Y), MFR (Y-1), and MFR (Y-2) are independent. is not. Therefore, in order to control the MFR (Y), three factors, the weight ratio of the propylene-ethylene copolymer (Y-2), the MFR (Y-1), and the MFR (Y-2), may be controlled. For example, in order to increase MFR (Y), MFR (Y-1) may be increased or MFR (Y-2) may be increased. Further, when MFR (Y-2) is lower than MFR (Y-1), even if W (Y-1) is increased and W (Y-2) is decreased, MFR (Y) is increased. You can easily understand what you can do. The same applies to the control method in the reverse direction.
To describe which of these methods is more preferable, it is necessary to control the MFR (Y-2) to a value low to some extent from the specification of (Yv) described later, and when controlling the MFR (Y), , MFR (Y-1) and / or a method of controlling the weight ratio of (Y-1) and (Y-2) is desirable. Furthermore, since the weight ratio of (Y-1) and (Y-2) is limited by (Y-i) described above, it is most preferable to use a method of controlling MFR (Y-1).
The most convenient method for controlling MFR (Y-1) and MFR (Y-2) is to use hydrogen as a chain transfer agent. Specifically, when the concentration of hydrogen, which is a chain transfer agent, is increased, the MFR (Y-1) of the propylene (co) polymer (Y-1) is increased. The reverse is also true. In order to increase the concentration of hydrogen in the polymerization tank, the amount of hydrogen supplied to the polymerization tank may be increased, which is extremely easy for those skilled in the art. The same applies to the control of MFR (Y-2).

2-3. Characteristics (Y-iii): Melting point The melting point of the propylene-based block copolymer (Y) used in the present invention is preferably more than 155 ° C, preferably more than 157 ° C, from the viewpoint of maintaining the heat resistance of the sheet. Is more preferable. The upper limit of the melting point does not need to be particularly limited, but it is practically difficult to produce a product having a melting point exceeding 170 ° C.
For the melting point, use differential operating calorimetry (DSC) to raise the temperature to 200 ° C once to erase the heat history, then lower the temperature to 40 ° C at a temperature lowering rate of 10 ° C / min, and then raise the temperature again. The temperature is the temperature of the endothermic peak when measured at 10 ° C./min.
Since the melting point of the propylene-based block copolymer (Y) is mainly determined by the melting point of the propylene (co) polymer (Y-1), when controlling the melting point of the propylene-based block copolymer (Y), It is preferable to control the melting point of the propylene (co) polymer (Y-1). The melting point of the propylene-based block copolymer (Y) is determined by the MFR (Y-1) and comonomer content of the propylene (co) polymer (Y-1). Increasing the MFR (Y-1) lowers the melting point of (Y-1), and increasing the comonomer content also lowers the melting point of (Y-1). It is easy for those skilled in the art to investigate the relationship between the MFR (Y-1) and comonomer contents and the melting point in advance and adjust the MFR (Y-1) and comonomer contents so as to obtain the desired melting point. ..

2-4. Characteristics (Y-iv): Ethylene content in the propylene-ethylene copolymer component (Y-2) In the present invention, the ethylene content in the propylene-ethylene copolymer component (Y-2) is 11 to 38% by weight. It is preferable that there is (however, the total amount of the monomers constituting the component (Y-2) is 100 wt%). A more preferable range of the ethylene content in the propylene-ethylene copolymer component (Y-2) is 16 to 36 wt%, more preferably 18 to 35 wt%.
The ethylene content in the propylene-ethylene copolymer component (Y-2) is usually controlled by appropriately adjusting the amount ratio of ethylene supplied to the polymerization tank to propylene. The copolymerization characteristics of the catalyst to be used may be investigated in advance, and the supply amount ratio of the monomers may be adjusted so that the gas composition of the polymerization tank becomes a value corresponding to the desired ethylene content.
When an ethylene content in the above range is used, the effect of suppressing the formation of a structure formed by polypropylene (X) having a long-chain branched structure under shear flow appears, and if it deviates from this, the suppressing effect is small. Become. The present inventors speculate as to the reason as follows.
The propylene-based block copolymer (Y) according to the present invention has a function of suppressing the formation of a unique structure of polypropylene (X) having a long-chain branched structure under shearing. Since the structure is a so-called shishi-kebab structure (or a precursor thereof), it is a component having as low a crystallinity as possible, and in order to suppress the growth of the structure, the motility is as low as possible, that is, the molecular weight is high. Ingredients are considered preferred. However, if the ethylene content is less than this specified range, (Y-2) itself has crystallinity, and the formation of the shishi-kebab structure cannot be suppressed. On the other hand, when the ethylene content of (Y-2) is too high, the component (Y-2) forms a sea-island structure with the component (Y-1) and exists as a completely different phase. Therefore, it cannot act on the formation of the shishi-kebab structure. That is, the ethylene content in (Y-2) needs to be in a range that does not have much crystallinity while maintaining compatibility with the crystalline propylene component to some extent.

2-5. Characteristics (Yv): Intrinsic viscosity of propylene-ethylene copolymer component (Y-2) The propylene-ethylene copolymer component (Y) constituting the propylene-based block copolymer (Y) blended with polypropylene (X). The intrinsic viscosity value of Y-2) measured using 135 ° C. decalin as a solvent is preferably 5.3 dl / g or more, more preferably 6.0 dl / g or more, still more preferably 7.0 dl / g or more. Most preferably, it is 7.5 dl / g or more.

The propylene-based block copolymer (Y) according to the present invention has a function of suppressing the formation of a unique structure in a shear field by polypropylene (X) having a long-chain branched structure. Since the structure is a so-called shishi-kebab structure (or a precursor thereof), a component having as low crystallinity as possible and a component having as low motility as possible to suppress the growth of the structure, that is, a component having a high molecular weight. Is considered preferable. By setting the intrinsic viscosity value to be equal to or higher than the lower limit of this range, the effect of suppressing the formation of the sissy kebab structure can be increased.
The upper limit value does not need to be specified in particular, but if it is set to the upper limit or less, gel generation can be suppressed. Therefore, 15.0 dl / g or less, preferably 14.0 dl / g or less, more preferably 13.0 dl / g or less. Most preferably, it is 12.0 dl / g or less.
The intrinsic viscosity here is a value measured using a Ubbelohde type capillary viscometer at a temperature of 135 ° C. and using decalin as a solvent. In order to obtain the intrinsic viscosity of (Y-2), the component (Y-2) is recovered as a 25 ° C. paraxylene-soluble component by using the same method as described in CXS described above, and the intrinsic viscosity of the component is measured. Assumed to be performed. However, if the ethylene content of the component (Y-2) is less than 15% by weight, it becomes difficult to sufficiently separate the component (Y-2) depending on the CXS method. In such a case, a small amount of the component (Y-1) in the process of sequential polymerization is extracted, the intrinsic viscosity is measured, and the intrinsic viscosity of the entire (Y) after the completion of the sequential polymerization is measured by the following formula. It shall be sought.
Intrinsic viscosity of (Y-2) component = [Intrinsic viscosity of (Y) as a whole-{Intrinsic viscosity of (Y-1) component x Weight fraction of (Y-1) component / 100}] / {(Y-2) ) Intrinsic weight fraction / 100}

The intrinsic viscosity [η] is an amount corresponding to the molecular weight, and the method of using hydrogen as a chain transfer agent is the most convenient for controlling the intrinsic viscosity [η], as in the case of MFR. Specifically, when the concentration of hydrogen, which is a chain transfer agent, is increased, the intrinsic viscosity [η] of the propylene-ethylene copolymer (Y-2) becomes smaller. The reverse is also true. In order to increase the concentration of hydrogen in the polymerization tank, the amount of hydrogen supplied to the polymerization tank may be increased, which is extremely easy for those skilled in the art.

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

(1) Analytical device to be used (i) Cross sorting device CFC T-100 (abbreviated as CFC) manufactured by Dia Instruments Co., Ltd.
(Ii) Fourier Transform Infrared Absorption Spectrum Analysis FT-IR, PerkinElmer 1760X
The fixed wavelength infrared spectrophotometer attached as the detector of CFC is removed, and FT-IR is connected instead, and this FT-IR is used as a detector. The transfer line from the outlet of the solution eluted from CFC to FT-IR shall be 1 m long and the temperature shall be maintained at 140 ° C. throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1 mm and an optical path width of 5 mm, and the temperature is maintained at 140 ° C. throughout the measurement.
(Iii) Gel Permeation Chromatography (GPC)
The GPC column in the latter stage of the CFC is used by connecting three AD806MS manufactured by Showa Denko in series.

(2) CFC measurement conditions (i) Solvent: Orthodichlorobenzene (ODCB)
(Ii) Sample concentration: 4 mg / mL
(Iii) Injection volume: 0.4 mL
(Iv) Crystallization: The temperature is lowered from 140 ° C. to 40 ° C. over about 40 minutes.
(V) Sorting method:
The fractionation temperature at the time of temperature rise elution separation is 40, 100, 140 ° C., and the fractions are separated into three fractions in total. The elution ratio (unit weight%) of the component eluted at 40 ° C. or lower (fraction 1), the component eluted at 40 to 100 ° C. (fraction 2), and the component eluted at 100 to 140 ° C. (fraction 3) is W40, respectively. , W100, W140. W40 + W100 + W140 = 100. Further, each of the separated fractions is automatically transported to the FT-IR analyzer as it is.
(Vi) Solvent flow rate at elution: 1 mL / min

(3) FT-IR measurement conditions After the elution of the sample solution starts from the GPC in the subsequent stage of CFC, FT-IR measurement is performed under the following conditions, and GPC-IR data is collected for each of the above fractions 1 to 3. ..
A conceptual diagram of CFC-FT-IR is shown in FIG.
(I) Detector: MCT
(Ii) Resolution: 8 cm ^-1
(Iii) Measurement interval: 0.2 minutes (12 seconds)
(Iv) Number of integrations per measurement: 15 times

(4) Post-treatment and analysis of measurement results The elution amount and molecular weight distribution of the components eluted at each temperature are determined by using the absorbance of 2945 cm- ¹ obtained by FT-IR as a chromatogram. The elution amount is standardized so that the total elution amount of each elution component is 100%. The conversion from the holding capacity to the molecular weight is performed using a calibration curve prepared in advance using standard polystyrene. The specific method is the same as that described above.
For the ethylene content distribution of each eluted component (distribution of ethylene content along the molecular weight axis), polyethylene, polypropylene, or ¹³ using the ratio of the absorbance of 2956 cm ^-1 obtained by GPC-IR to the absorbance of 2927 cm ^-1. Using ethylene-propylene-rubber (EPR) whose ethylene content is known by C-NMR measurement and a mixture thereof, the ethylene content (% by weight) is determined by a calibration curve prepared in advance. Convert and calculate.

(5) Proteylene-Ethylene Copolymer Content The recommended propylene-ethylene copolymer (Y-2) (hereinafter referred to as EP) content of the propylene-based block copolymer (Y) in the present invention is as follows. It is defined by the formula (I) and is obtained by the following procedure.
EP content (% by weight) = W40 x A40 / B40 + W100 x A100 / B100 + W140 x A140 / B140 (I)
W40, W100, and W140 are the elution ratios (unit weight%) in each of the above-mentioned fractions, and A40, A100, and A140 are the average ethylene contents (actually measured) in each fraction corresponding to W40, W100, and W140. Unit weight%), and B40, B100, and B140 are the ethylene contents (unit weight%) of EP contained in each fraction.
How to obtain A40, A100, A140, B40, B100, B140 will be described later.
The meaning of equation (I) is as follows. The first term on the right side of the equation (I) is a term for calculating the amount of EP contained in fraction 1 (a portion soluble at 40 ° C.). When fraction 1 contains only EP and does not contain PP, W40 directly contributes to the EP content derived from fraction 1 in the whole, but fraction 1 contains a small amount in addition to the components derived from EP. Since PP-derived components (extremely low molecular weight components and atactic polypropylene) are also contained, it is necessary to correct those parts. Therefore, by multiplying W40 by A40 / B40, the amount derived from the EP component in fraction 1 is calculated. For example, when the average ethylene content (A40) of fraction 1 is 30% by weight and the ethylene content (B40) of EP contained in fraction 1 is 40% by weight, 30/40 = 3/4 of fraction 1. (That is, 75% by weight) is derived from EP, and the remaining 1/4 is derived from PP. The operation of multiplying A40 / B40 in the first term on the right side as described above means that the contribution of EP is calculated from the weight% (W40) of fraction 1. The same applies to the second and subsequent terms on the right-hand side, and the EP content is the sum of the EP contributions calculated for each fraction.

(I) As described above, the average ethylene contents corresponding to fractions 1 to 3 obtained by CFC measurement are A40, A100, and A140, respectively (units are all by weight). How to obtain the average ethylene content will be described later.
(Ii) Let B40 be the ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 (unit is weight%). Fractions 2 and 3 are defined as B100 = B140 = 100 in the present invention because it is considered that all the rubber portions elute at 40 ° C. and cannot be defined by the same definition. B40, B100, and B140 are the ethylene contents of EP contained in each fraction, but it is practically impossible to determine this value analytically. The reason is that there is no means to completely separate and separate PP and EP mixed in the fraction. As a result of examination using various model samples, it was found that B40 can well explain the effect of improving the material properties by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. It was. Further, B100 and B140 have two reasons: they have crystallinity derived from an ethylene chain, and the amount of EP contained in these fractions is relatively small compared to the amount of EP contained in fraction 1. Therefore, it is closer to the actual situation when both are close to 100, and almost no error occurs in the calculation. Therefore, the analysis is performed with B100 = B140 = 100.

(Iii) The EP content is determined according to the following formula.
EP content (% by weight) = W40 x A40 / B40 + W100 x A100 / 100 + W140 x A140 / 100 (II)
That is, W40 × A40 / B40, which is the first term on the right side of equation (II), indicates the EP content (% by weight) having no crystallinity, and is the sum of the second term and the third term, W100 × A100 / B40. 100 + W140 × A140 / 100 indicates the EP content (% by weight) having crystallinity.
Here, the average ethylene contents A40, A100, and A140 of each of the fractions 1 to 3 obtained by B40 and CFC measurement are determined as follows.
Fraction 1 separated by the difference in crystal distribution is converted into a molecular weight distribution curve by a curve in which the molecular weight distribution is measured by a GPC column constituting a part of the CFC analyzer, and an FT-IR connected behind the GPC column. Obtain the distribution curve of the ethylene content measured correspondingly. The ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B40.
Further, the sum of the product of the weight ratio for each data point and the ethylene content for each data point, which is taken in as data points at the time of measurement, is the average ethylene content A40.

The significance of setting the above three types of sorting temperatures is as follows.
In the CFC analysis of the present invention, 40 ° C. refers only to non-crystalline polymers (for example, most of EP, or extremely low molecular weight components and tactical components among propylene polymer components (PP)). It is significant that the temperature conditions are sufficient and necessary for sorting. Further, 100 ° C. means a component that is insoluble at 40 ° C. but soluble at 100 ° C. (for example, a component having crystallinity due to the chain of ethylene and / or propylene in EP, and a component having low crystallinity. The temperature is sufficient to elute only PP). Further, 140 ° C. refers to a component that is insoluble at 100 ° C. but soluble at 140 ° C. (for example, a component having particularly high crystallinity in PP, and a component having extremely high molecular weight and ethylene crystallinity in EP. ) Is eluted, and the temperature is sufficient to recover the entire amount of the propylene-based block copolymer used for analysis. The EP component contained in W140 is extremely small and can be substantially ignored.
Ethylene content in EP (% by weight) = (W40 x A40 + W100 x A100 + W140 x A140) / [EP] (III)
However, [EP] is the EP content (% by weight) obtained earlier.
The ethylene content (E) (% by weight) of the non-crystalline portion of EP is approximated by the value of B40 because the elution of the rubber portion is completed at almost 40 ° C. or lower.

However, in the analysis method using the combination of the above-mentioned cross fractionation method and FT-IR, the ethylene content of (Y-2) is less than 15 wt%, there is no big difference in crystallinity from (Y-1), and the fractionation is based on temperature. In cases where this cannot be done sufficiently, accurate analysis becomes difficult. In such a case, the component (Y-1) is extracted during the step-growth polymerization, its molecular weight (when the comonomer is copolymerized, the comonomer content is also measured), and further calculated by material balance. , (Y-1) and (Y-2) components, and by measuring the comonomer content of the entire component (Y) at the end of step-growth polymerization, the following simple addition rule of weight It is preferable to determine the copolymer content of the component (Y-2) by using. When ethylene is used as the comonomer, the ethylene content of (Y-2) shall be determined by the following formula.
Ethylene content of component (Y-2) = [(Y) total ethylene content-{(Y-1) component ethylene content x (Y-1) component weight fraction / 100}] / {(Y-2) ) Component weight fraction / 100}

Regarding other methods for determining the quantitative ratio of the (Y-1) component and the (Y-2) component, when producing a product in which the average molecular weights of the (Y-1) component and the (Y-2) component differ to some extent. , GPC measurement of the whole (Y) after the completion of step-growth polymerization is performed, and the obtained multimodal molecular weight distribution curve is peak-separated using commercially available data analysis software or the like, and the weight ratio thereof is calculated. It is also possible.

A polypropylene resin composition for injection foam molding, which comprises a propylene-ethylene block copolymer having the same characteristics as described above, another propylene polymer, and a foaming agent, is disclosed in Japanese Patent Application Laid-Open No. 2010-150509. However, a close examination of the examples shows that the other polypropylene polymer uses a propylene-ethylene block copolymer having an MFR of 30 g / 10 min and has a long-chain branched structure disclosed in the present invention. No technical suggestion is made regarding the problem of solving the problems peculiar to polypropylene.
Further, Japanese Patent Application Laid-Open No. 2010-121054 describes a propylene-ethylene block copolymer (component B) having the same characteristics as described above, a crystalline polypropylene having a specific MFR (component A), and a specific intrinsic viscosity. From any of polypropylene polymer (component C) composed of olefin polymer and polypropylene that meets the range, hydrogen additive of styrene-conjugated diene block copolymer, ethylene-α-olefin copolymer rubber, and ethylene polymer resin. A polypropylene-based resin composition with a kind of thermoplastic resin to be selected is disclosed as a composition suitable for foam blow molding, but this also solves the problem peculiar to polypropylene having a long-chain branched structure. No technical suggestion has been made regarding the problem, and it should be understood that it is a technical category different from the present invention.
Further, in Patent Document 10, 50 to 90% by weight of a propylene homopolymer having an MFR of 10 to 1000 g / 10 and a propylene-α-olefin copolymer having an α-olefin other than propylene of less than 1% by weight, weight average. It consists of 10 to 50% by weight of a propylene-α-olefin copolymer having a molecular weight of 500,000 to 10 million and an α-olefin content other than propylene of 1 to 15% by weight, and has a specific MFR, MFR-MT balance, and maximum relaxation time. Although a foamed sheet composed of a propylene-based resin composition portion having a propylene-based resin composition is disclosed, the problem peculiar to polypropylene having a long-chain branched structure is solved by a specific ultra-high molecular weight propylene-ethylene copolymer component. No technical suggestion has been made regarding this issue. Further, when the examples are closely examined, only 3 to 10% by weight of ethylene is disclosed as the α-olefin content of the component having a high molecular weight, and ethylene as the component (Y-2) specified in the present invention is disclosed. It is different from the content. As will be described in detail later in Examples, when the ethylene content of the component (Y-2) is at this level, polypropylene (X) having a long-chain branched structure, which is the object of the present invention, is under shearing. The effect of suppressing the formed shear kebab structure (or its precursor) is not seen.

VI. Polypropylene resin composition The polypropylene resin composition of the present invention contains 10 to 99% by weight of polypropylene (X) and 1 to 90% by weight of propylene block copolymer (Y), and has a melt tension (MT) measured at 230 ° C. ) Is 1 g or more, and the number of gels having a major axis of 0.5 mm or more is 50 pieces / m ² or less when a non-stretched film having a thickness of 25 μm is used. Polypropylene (X) has been described above. The matters of are explained in detail below in order.

VI-1. Method for Producing Resin Composition As the method for preparing the polypropylene resin for foam molding and the polypropylene resin composition for foam molding of the present invention, known methods can be used. For example, a resin composition can be prepared by mixing a predetermined amount of polypropylene (X), a propylene-based block copolymer (Y), and an arbitrary additive described later with a dry blend, a Henschel mixer, or the like. it can. Further, 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 it 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), a propylene-based block copolymer (Y), and an arbitrary additive is melt-kneaded and pelletized.
b. A mixture of polypropylene (X) and an arbitrary additive is melt-kneaded and pelletized, and polypropylene (X) composition pellets are further mixed with the propylene-based block copolymer (Y) and any additive, and then melted. Knead and pelletize.
b'. A mixture of a propylene-based block copolymer (Y) and an arbitrary additive is melt-kneaded and pelletized, further mixed with polypropylene (X) and an arbitrary additive, and then melt-kneaded.
c. A mixture of polypropylene (X) and an arbitrary additive and a mixture of a propylene-based block copolymer (Y) and an arbitrary additive were melt-kneaded to obtain respective pellets, and each obtained. Mix the pellets.
d. A mixture of polypropylene (X) and an arbitrary additive and a mixture of a propylene-based block copolymer (Y) and an arbitrary additive were melt-kneaded to obtain respective pellets, and each obtained. Pellets are mixed, and the pellets are further melt-kneaded to be pelletized.
Such a method can be used.
Here, as a method for pelletizing the resin composition, the present invention is carried out by "melting and kneading a mixture of polypropylene (X) and an arbitrary additive" described in b, c and d above to pelletize the resin composition. The polypropylene resin for foam molding of the present invention can be prepared.

Here, the polypropylene resin composition of the present invention has a melt tension (MT) measured at 230 ° C. of 1 g or more, preferably 3 g or more, which is a polypropylene (X) and propylene block copolymer. It is a value measured using the melt-kneaded product of (Y). Therefore, when these are simply mixed and used, or when polypropylene (X) and propylene block copolymer (Y) are mixed (dry blended) as in c, the resin for extrusion foaming is not melt-kneaded. When used as a composition, polypropylene (X), propylene block copolymer (Y), and optional components are separately melt-kneaded using the same composition, and MT is measured using the obtained pellets. The value thus obtained is defined as the MT value of the polypropylene resin composition for extrusion foaming. In this case, melt-kneading is carried out using the method described in Examples described later.

VI-2. Content of Polypropylene (X) and Propylene Block Copolymer (Y) The content of polypropylene (X) in the polypropylene resin composition of the present invention is 10 to 99 wt%. To exemplify a more preferable range, the content of polypropylene (X) is more preferably 10 to 90 wt%, still more preferably 15 to 80 wt%. Correspondingly, the content of the propylene-based block copolymer (Y) in the polypropylene resin composition is 1 to 90 wt%, preferably 10 to 90 wt%, and more preferably 20 to 85 wt% (polypropylene (X)). And the propylene block copolymer (Y) are 100 wt%).
By setting the content of polypropylene (X) having a long-chain branch to the lower limit of the above range or more, an increase in the open cell ratio of the foamed molded product can be suppressed, and the drawdown can be reduced during thermoforming. .. By setting the content of polypropylene (X) to be equal to or less than the upper limit of the above range, the ductility can be maintained high, the appearance of the sheet or film can be improved, and the extrusion amount can be increased to improve the productivity. The content of polypropylene (X) and the propylene-based block copolymer (Y) can be adjusted to a desired content by adjusting the blend amount ratio when preparing the resin composition.

VI-3. MFR
Preferably, the polypropylene resin composition of the present invention has an MFR of 0.1 to 20 g / 10 minutes. To exemplify a more preferable range, 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. By setting the MFR to be equal to or higher than the lower limit of this range, the ductility can be improved, the appearance of the sheet or film can be improved, and the extrusion amount can be increased to improve the productivity. By setting the MFR to or less than the upper limit of this range, it is possible to suppress an increase in the open cell ratio of the foamed molded product, keep the size of the bubbles uniform, and suppress drawdown during thermoforming.
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 the propylene-based block copolymer (Y). Further, when the MFRs of polypropylene (X) and propylene-based block copolymer (Y) are different, the MFR of the polypropylene resin composition can be adjusted by changing the blending amounts of both. For example, when the MFR of polypropylene (X) is higher than the MFR of the propylene-based block copolymer (Y), the MFR of the polypropylene resin composition increases as the blending amount of polypropylene (X) increases.

VI-4. Melt tension (MT)
The polypropylene resin composition of the present invention must have a melt tension (MT) measured at 230 ° C. of 1 g or more. It is preferably 1.5 g or more, more preferably 2 g or more, most preferably 3 g or more, preferably 20 g or less, more preferably 15 g or less, and most preferably 10 g or less. Here, the MT of the polypropylene resin composition is a value obtained by using the same measuring method as the melt tension (MT) of the characteristic (X-ii) of polypropylene (X). By setting MT to be equal to or higher than the lower limit of the above value, it is possible to maintain good cell formation and growth during foaming, suppress an increase in the open cell ratio, and make the cell size uniform. By setting MT to be equal to or lower than the upper limit of the above value, ductility can be improved, the appearance of the sheet or film can be improved, and the extrusion amount can be increased to improve productivity.
There are several ways to adjust the MT within the above range. For example, the MT of polypropylene (X) may be changed, or the blending amount of polypropylene (X) and the propylene-based block copolymer (Y) may be changed. In general, increasing the content of polypropylene (X) can increase the MT of the resin composition.

VI-5. Propylene (co) polymer (H)
In particular, in fields such as foam molding where high melt tension is required, it is required to dilute a resin composition having high melt tension with another resin from the viewpoint of achieving both physical properties and economy of the product. There are many cases.
In the polypropylene resin composition of the present invention, polypropylene (X) and propylene-based block copolymer (Y), which are constituents thereof, each play a role of improving foaming performance, and the resin that inhibits these plays a role. Dilution interferes with the effects of the present invention.
Therefore, it is preferable to use another resin for dilution within a range that does not significantly impair the effects of the present invention. In the polypropylene resin composition of the present invention, polypropylene (X) and propylene-based block copolymer (Y) organically affect each other to exhibit a high effect on foaming performance, and other resins for dilution are exhibited. Even if diluted with, it is easy to maintain a high effect.

In the present invention, the preferred resin used for dilution for improving economic efficiency while maintaining foaming performance is at least selected from the group consisting of propylene copolymer or ethylene and α-olefin having 4 to 10 carbon atoms. It is a copolymer (H) of one kind of olefin and propylene, and when the propylene (co) polymer (H) is a copolymer, ethylene and α- in the propylene (co) polymer (H) A propylene (co) copolymer (H) having an olefin content of more than 0 and 3 wt% or less is preferable.
This dilutes the propylene (co) copolymer (H) having the same performance as the propylene (co) polymer (Y-1) contained in the propylene-based block copolymer (Y), which is a constituent requirement of the present invention. When used as a material, the content of polypropylene (X) in the diluted resin composition and the propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) is determined by the resin of the present invention. It is based on the fact that the foaming properties are not deteriorated when it can be maintained within the range of the composition.
On the other hand, when other propylene-based block copolymers or polyethylene-based resins that do not satisfy the requirements for the propylene-based block copolymer (Y) according to the present invention are used as diluents, they are propylene-based block copolymers ( Care must be taken in selecting the diluent because it may inhibit the improving effect of the propylene-ethylene copolymer (Y-2) in Y) and significantly inhibit the effect of the present invention.
Whether or not the effect of the present invention is significantly inhibited is determined by, for example, whether or not the open cell ratio shows a value of about 3 times that of the case where the diluent is used and the case where 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 10 to 300 parts by weight, based on 100 parts by weight of the polypropylene resin composition. It is a department. The content of polypropylene (X) in the diluted resin composition and the propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) can be maintained within the specified range of the polypropylene resin composition. The range is preferable, and the ratio of (Y-2) in the polypropylene resin composition 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. It is preferable to determine the blending amount of the propylene (co) polymer (H) so as to be more preferably 4 to 25.5 wt%.

VI-6. Additives Various additives can be added as optional components to the polypropylene resin composition of the present invention. Specifically, antioxidants, UV absorbers, light stabilizers, metal deactivators, stabilizers, neutralizers, lubricants, antistatic agents, antifogging agents, which are used as conventionally known compounding agents for polyolefin resins. Various additives such as nucleating agents, peroxides, fillers, antibacterial fungicides, and fluorescent whitening agents can be added as long as the effects of the present invention are not impaired. The blending 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 deterioration of polyolefin is a radical chain reaction via peroxide radicals or hydroperoxide compounds generated by the action of oxygen with heat, light, mechanical force, metal ions, etc., and is generally called autoxidation. .. Antioxidants are used to suppress this autoxidation, and depending on where they act in the chain reaction, there are three major types: phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. It is common to be separated.
Phenolic antioxidants are radical supplements, and since the radicals generated by reacting with peroxide radicals and the like are relatively stable, the radical concentration in the system can be lowered. Generally, a substituted phenol compound, particularly a substituted phenol compound having a bulky substituent at the ortho position is used.

Hereinafter, typical compounds will be exemplified as phenolic antioxidants.
Among monophenol type compounds, 2,6-di-t-butyl-4-methylphenol (commonly known as BHT), tocopherol (vitamin E), n-octadecyl-3- (4'-hydroxy-3', 5') -Di-t-butylphenyl) propionate (trade name: Irganox 1076, simmerizer BP-76) can be exemplified.
Among bisphenol type compounds, 2,2'-methylenebis (4-methyl-6-t-butylphenol) (trade name: Sumilyzer MDP-S), 1,1-bis (2'-methyl-4'-hydroxy-5) '-T-Butylphenyl) Butan (trade name: Sumilyzer BBM-S, Adecastab 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 name: Sumilyzer GA-80, Adecastab AO-80) can be exemplified.
Among the triphenol type compounds, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (trade name: Adecastab AO-30), 1,3,5-trimethyl-2 , 4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene (trade name: Irganox1330, Adecastab AO-330), Tris- (3,5-di-t-butyl-4-4) Hydroxybenzyl) -isocyanurate (trade name: Irganox3114, Adecastab AO-20), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (trade name: smilizer) BP-179, Cyanox1790), Tris- (3,5-di-t-butyl-4-hydroxyphenyl) -isocyanurate (trade name: Cheminox 314) can be exemplified.
As the tetraphenol type compound, tetrakis {methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate} methane (trade name: Irganox1010) can be exemplified.

Phosphorus-based antioxidants have the effect of reducing hydroperoxide compounds and are also called hydroperoxide decomposing agents. Although it has an antioxidant effect by itself, when it is 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 is regenerated by the reduction of the phenoxy radical species generated by the reaction between the phenolic antioxidant and the radical species involved in autoxidation by the phosphorus-based antioxidant. It is believed that.

Hereinafter, typical compounds will be exemplified as phosphorus-based antioxidants.
Among the phosphite type compounds, tris (2,4-di-t-butylphenyl) phosphite (trade name: Irgafos168, smilizer P-16, adecastab 2112), trisnonylphenyl phosphite (trade name: smilizer TNP, adecastab) 1178), Tris (mixed, mono-dinonylphenyl phosphite) (trade name: Adecastab 329K), tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite (commonly known as: P-EPQ), cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenylphosphite) (trade name: Adecaster PEP-36) can be exemplified.

Similar to phosphorus-based antioxidants, sulfur-based antioxidants also have the effect of reducing hydroperoxide compounds, and are also called hydroperoxide decomposing agents. Similar to phosphorus-based antioxidants, it is said that there is a synergistic effect when used in combination with phenol-based antioxidants.
Hereinafter, typical compounds will be exemplified as sulfur-based antioxidants.
Among sulfide-type compounds, dilauryl-3,3'-thio-dipropionate (commonly known as DLTDP), di-myristyl-3,3'-thio-dipropionate (commonly known as DMTDP), distearyl-3,3'-thio- Dipropionate (commonly known as DSTDP), pentaerythritol-tetrakis- (3-laurylthio-propionate) (trade name: Sumilyzer TP-D, Adecastab AO-412S) can be exemplified.

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 light, radicals are generated and autoxidation occurs. The ultraviolet absorber has an effect of suppressing the generation of radicals by absorbing ultraviolet rays, and the light stabilizer has an effect of capturing and inactivating radicals generated by ultraviolet rays.
The ultraviolet absorber is a compound having an absorption band in the ultraviolet region, and is known to be triazole-based, benzophenone-based, salicylate-based, cyanoacrylate-based, nickel chelate-based, inorganic fine particle-based, and the like. The most commonly used of these is the triazole system.
Hereinafter, typical compounds as ultraviolet absorbers will be illustrated.
Among triazole-based compounds, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole (trade name: Sumisorb 200, TinuvinP), 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole (Product names: Sumisorb 340, Tinuvin 399), 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) benzotriazole (Product names: Sumisorb 320, Tinuvin 320), 2- (2'-hydroxy) -3', 5'-di-t-amylphenyl) Benzotriazole (trade name: Sumisorb 350, Tinuvin328), 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5 Chlorobenzotriazole (trade name: Sumisorb 300, Tinuvin 326) can be exemplified.
Examples of benzophenone-based compounds include 2-hydroxy-4-methoxybenzophenone (trade name: Sumisorb 110) and 2-hydroxy-4-n-octoxybenzophenone (trade name: Sumisorb 130).
As the salicylate-based compound, 4-t-butylphenyl salicylate (trade name: Seasorb 202) can be exemplified. As the cyanoacrylate-based compound, ethyl (3,3-diphenyl) cyanoacrylate (trade name: Seasove 501) can be exemplified. As a nickel chelate compound, nickel dibutyldithiocarbamate (trade name: Antigen NBC) can be exemplified. Examples of the inorganic fine particle-based compound include TiO ₂ , ZnO ₂ , and CeO ₂ .

As the light stabilizer, it is common to use a hindered amine compound, which is called HALS. HALS has a 2,2,6,6-tetramethylpiperidine skeleton and cannot absorb ultraviolet rays, but suppresses photodegradation by a wide variety of functions. It is said that its three main functions are the capture of radicals, the decomposition of hydroxyperoxide compounds, and the capture of heavy metals that accelerate the decomposition of hydroxyperoxide.
Hereinafter, representative compounds as HALS will be exemplified.
Among sebacate-type compounds, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (trade names: Adecastab LA-77, Tinuvin770), bis (1,2,2,6,6-pentamethyl-) 4-Piperidyl) sebacate (trade name: Tinuvin765) can be exemplified.
Among the butanetetracarboxylate type compounds, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (trade name: Adecastab LA-57), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (trade name: Adecastab LA-52), 1,2,3,4-butanetetra Condensate of carboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol (trade name: Adecastab 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: Adecastab LA-62) can be exemplified.
In the polyester succinate type compound, a condensation polymer of succinic acid and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine can be exemplified.
For triazine-type compounds, 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-tetra) Methyl-4-piperidyl) imino} (trade name: Chimasorb 3346) can be exemplified.

Some other additives will also be illustrated.
Lubricants are additives used to improve moldability and fluidity, and have 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 the 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, and stearic acid. There are higher fatty acid salts such as calcium phosphate, partial esters of polyhydric alcohols such as stearic acid monoglyceride, and silicon oil.
Among these, specific examples of higher fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, oleic acid amides, erucic acid amides, and bechenic acid amides. The fatty acid amide compound may have a substituent on the alkyl chain or N. Examples of fatty acid amide compounds having substituents include hydroxystearic acid amide, N-oleyl palmitate amide, N-stearyl oleic acid amide, N-stearyl erucic acid amide, methylene bisstearic acid amide, ethylene bisstearate amide, Can be mentioned.

Stabilizers are additives for polyvinyl chloride (PVC) in the first place, and are used for the purpose of preventing hydrochloric acid (HCl) from desorbing from PVC and deteriorating. Since some compounds among various stabilizers also have a function as a neutralizing agent, they may also be used as an additive for polyolefin.
The neutralizer is a compound used to neutralize the chlorine component derived from the Ziegler catalyst 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 trapping ability can also be used. Both are compounds used as stabilizers. Basically, when using a metallocene catalyst that does not contain chlorine atoms, it is an additive that is not originally necessary, but since chlorine atoms are a chemical species that easily contaminates, they are used as insurance from the viewpoint of stable production. Is often done.
Hereinafter, typical compounds as neutralizing agents will be illustrated.
Examples of the carboxylate type compound include calcium stearate and zinc stearate. Examples of the inorganic compound include hydrotalcite and inclusions of aluminum hydroxide and lithium carbonate (trade name: Mizukarak).

VII. Extrusion foam molding, polypropylene-based foam sheet, heat-molded body The polypropylene resin for foam molding and polypropylene resin composition for foam molding of the present invention can be used for extrusion molding, injection molding, heat molding, calendar molding, press molding and the like. However, it is particularly suitable for various extrusion foam moldings because it has excellent air bubble retention and moderate melt tension and therefore has good spreadability. What kind of extrusion foam molding is used is not particularly limited.
Typical extrusion foam molding includes foam molding by foam sheet molding, foam film molding, foam blow molding, bead foam molding and the like. In the case of foam sheet molding, a combination of a known extruder and a die can be used.
The extruder may be uniaxial or biaxial. The die may be a T die or a circular die. The same applies to the case of foam film molding. In the case of foam film molding, further stretching may be 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 accumulator type blow molding machine.
The details will be described below in order.

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

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

When a physical foaming agent is used, a bubble adjusting agent can be used, if necessary. Examples of the bubble adjusting agent include inorganic degradable foaming agents such as ammonium carbonate, baking soda, ammonium bicarbonate and ammonium nitrite, azo compounds such as azodicarboxylic amide, azobisisobutyronitrile and diazoaminobenzene, and N, N'-. Dinitrosopentan methylenetetramine and nitroso compounds such as N, N'-dimethyl-N, N'-dinitrosoterephthalamide, benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p, p'-oxybisbenzenesulfonyl semicarbadide, p- Degradable foaming agents such as toluenesulfonyl semicarbadide, trihydrazinotriazine, bariumazodicarboxylate, inorganic powders such as talc and silica, acidic salts such as polyvalent carboxylic acid, reaction of polyvalent carboxylic acid with sodium carbonate or sodium bicarbonate. A mixture or the like can be exemplified. These bubble adjusting agents may be used alone or in combination of two or more.
When using the bubble modifier, the amount of the bubble modifier to be blended is 0.01 to 5 weight by weight based on 100 parts by weight of the total of polypropylene (X) and propylene block copolymer (Y). It is preferably in the range of parts.

Specific examples of the degradable foaming agent (chemical foaming agent) include a mixture of sodium bicarbonate and an organic acid such as citric acid, an azo foaming agent such as azodicarboxylic amide and barium azodicarboxylic acid, and N, N'-dinitrosopentamethylene. Nitroso-based foaming agents such as tetramine, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, sulfohydrazide foaming agents such as p, p'-oxybisbenzenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, tri Hydrazinotriazine and the like can be mentioned.
The blending amount of the foaming agent is preferably in the range of 0.05 to 6.0 parts by weight, more preferably 0, with respect to 100 parts by weight of the total of polypropylene (X) and propylene block copolymer (Y). It is 05 to 3.0 parts by weight, more preferably 0.5 to 2.5 parts by weight, and particularly preferably 1.0 to 2.0 parts by weight.

VII-2. Polypropylene resin foam molded product The polypropylene resin foam molded product of the present invention is produced by using the polypropylene resin for foam molding and the polypropylene resin composition for foam molding of the present invention. In the present invention, the shape and molding method of the polypropylene resin foam molded product are not limited. The polypropylene resin foam molded product of the present invention is preferably a sheet, and the thickness of the foamed sheet is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm to 5 mm.
Polypropylene-based foam sheets are secondary processed by thermoforming and are widely used industrially mainly in various containers and the like. The polypropylene-based foam sheet is widely used in various applications because of its light weight.
Here, since the polypropylene-based foam sheet contains many bubbles (cells) in the sheet, if the cells are rough or uneven, these appear on the sheet surface, deteriorating the surface appearance and increasing the commercial value. It will drop. Further, when thermoforming is performed, it is necessary to heat the mold sufficiently in order to transfer the mold, but in the foamed sheet, the cell also expands at the time of heating. As a result, if the foam cell is rough, the surface is likely to be deteriorated, and if it is uneven, the sheet is torn during heating.
In order to solve these problems, it is considered necessary to form foam cells having a high closed cell ratio, which are dense and have the same size. However, the polypropylene resin for foam molding or the polypropylene resin for foam molding of the present invention is considered to be necessary. By using the composition, these can be realized, and as a foamed sheet, a sheet having an excellent appearance and high thermoforming suitability can be obtained.

VII-3. Polypropylene resin multi-layer foam sheet When manufacturing a polypropylene resin foam sheet, it can also be a multi-layer foam sheet.
Specifically, the foamed layer using the polypropylene resin for foam molding or the polypropylene resin composition for foam molding of the present invention and the non-foamed layer made of the thermoplastic resin composition may be coextruded. At this time, a known coextrusion method using a feed block or a multi-die using a plurality of extruders can be used.
The non-foaming layer used in the polypropylene resin multilayer foamed sheet using the polypropylene resin for foam molding or the polypropylene resin composition for foam molding of the present invention as the foam layer may be provided on any surface of the foam layer, and may be provided on any surface of the foam layer. It is also possible to have a structure (sandwich structure) in which the foamed layer is present between the non-foamed layers.

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

The polypropylene resin multilayer foamed sheet provided with the non-foamed layer has excellent strength, and at least the non-foamed layer is provided 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 foamed sheet with additional functions such as antibacterial property, soft feeling, and scratch resistance. preferable.

The thermoplastic resin constituting the thermoplastic resin composition used for the non-foamed layer includes high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and propylene-α as long as the effects of the present invention are not impaired. -Olefin copolymers, polyolefins such as poly-4-methyl-pentene-1, olefin elastomers such as ethylene-propylene elastomers, or other monomers copolymerizable with these, such as vinyl acetate, vinyl chloride, (meth). ) Copolymers and mixtures such as acrylic acid and (meth) acrylic acid ester can be selected.
Of these, polypropylene and propylene-α-olefin copolymers are preferable from the viewpoints of recyclability, adhesiveness, heat resistance, oil resistance, rigidity and the like. As the propylene-α-olefin copolymer, a propylene-based block copolymer obtained by multi-step polymerization of a propylene (co) polymer and an ethylene-propylene random copolymer using a plurality of or single-tank polymerization tanks. Including coalescence.
Of these, the propylene-based block copolymer is more preferable because it has an excellent balance between rigidity and impact resistance, and is a propylene-based block copolymer that satisfies the requirements that the propylene-based block copolymer (Y) must meet (however, however). When a polypropylene resin composition containing (which may be the same as or different from (Y)) is used for the non-foamed surface layer, the obtained sheet has a good surface appearance and heat. It is most suitable because it has a feature of high cell retention during molding. At this time, the content of the propylene-based block copolymer in the polypropylene resin composition used for the non-foamed surface layer is preferably 0.1 to 100% by weight.

Further, especially when used as a thermoformed body, the rigidity of the molded body is very important, but in order to improve this, a non-foaming layer is provided on the surface layer and an inorganic filler is applied to the non-foaming layer. It is preferable to mix. In the thermoplastic resin composition used as the non-foaming layer, it is desirable to add 50 parts by weight or less of the inorganic filler to 100 parts by weight of the thermoplastic resin. If it exceeds 50 parts by weight, the appearance of the sheet is likely to be spoiled due to the occurrence of shaving at the die outlet.
Examples of the inorganic filler include talcite, calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate and the like.

VII-4. Thermoformability The polypropylene-based foamed sheet and polypropylene-based multilayer foamed sheet in the present invention have high thermoforming suitability, and these can be evaluated by performing a drooping test. The sagging test is a test method in which a sheet is heated by a heater and the behavior of the sheet at that time is observed, as in thermoforming. The behavior of the sheet in the sagging test is as follows.
First, when the sheet is heated, it softens and expands, and the sheet hangs down once. During this period, the crystal melting is not yet sufficient, the ductility is insufficient during thermoforming, and the mold shape cannot be sufficiently transferred. When the heating progresses and the crystal melting becomes sufficient, the sheet once hung down shrinks due to the relaxation of the residual stress during sheet molding, and regains tension to the position at the time of heating. At this time, the crystals are sufficiently melted and the residual stress is also released, so that a molded product in which the mold is sufficiently transferred can be obtained at the time of thermoforming. As the heating progresses further, the viscosity decreases as the sheet temperature rises, and it begins to hang down due to its own weight and expansion of the cell, and eventually holes begin to open. When a hole is opened, it is naturally impossible to obtain a molded product by thermoforming, and even if the hole is not opened, if the sagging is large, the molded product comes into contact with the mold and the molded product cannot be obtained.
In the above behavior, the range in which thermoforming is possible is within the range from the time T1 when the sheet is re-tensioned to the time T2 until the hole is opened, and the wider the time width, the wider the moldable range. , T2-T1 can be obtained and used for evaluation of thermoformability. At this time, in this time range, the smaller the sagging, the easier it is to perform thermoforming, and since it is possible to form a larger molded body, the sagging amount D (T2) in T2 is divided by (T2-T1). It is defined as the average sagging speed VD [mm / s] in the moldable range, which can also be used for evaluation of thermoformability.

As for the state of the foamed cell, it is preferable that the cell size is small, dense, uniform in size, and highly independent. Specifically, the foam layer bubble diameter is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 300 μm or less. If the bubble diameter of the foam layer greatly exceeds 500 μm, the polypropylene-based foam sheet or the thermoformed body may have an appearance defect such as perforation, which is not preferable. The bubble diameter of the foamed layer is a value obtained by using an optical microscope by the method described in Examples.
Further, the independence of the cell can be judged by the open cell ratio. The open cell ratio is preferably 30% or less, more preferably 20% or less, still more preferably 15% or less. If the open cell ratio exceeds 30%, the foam cells in the foam sheet do not expand during thermoforming, and the thickness of the thermoformed body may decrease, which is not preferable. Further, it is not preferable because it may lead to deterioration of the heat insulating performance of the thermoformed body.
The open cell ratio is a value obtained by using an air pycnometer (manufactured by Tokyo Science Co., Ltd.) by the method described in the examples.

VII-5. Thermoformed body The thermoformed body of the present invention is the above-mentioned polypropylene resin foamed sheet or polypropylene resin multilayer foamed sheet thermoformed.
The heat molding method is not particularly limited, and 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. Methods such as molding, free drawing molding, plug-and-ridge molding, and ridge molding can be exemplified.

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

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

1. 1. Methods for Measuring Various Physical Properties The characteristics of polypropylene (X), a polypropylene resin composition composed of polypropylene (X) and a propylene-based block copolymer, were measured by the following methods.
1.1. Melt flow rate (MFR)
Measurement was performed in accordance with JIS K7210: 1999 Method A, Condition M (230 ° C., 2.16 kg load). The unit is g / 10 minutes.
1.2. Melt tension (MT)
The measurement was performed under the following conditions using a capillograph manufactured by Toyo Seiki Seisakusho.
・ Capillaries: diameter 2.0 mm, length 40 mm
・ Cylinder diameter: 9.55 mm
・ Piston extrusion speed: 20 mm / min ・ Pickup speed: 4.0 m / min ・ Temperature: 230 ° C
If the MT is extremely high, the resin may break at a pick-up speed of 4.0 m / min. In such a case, the pick-up speed is reduced and the tension at the maximum pick-up speed is increased to MT. And. The unit is grams.

Ratio of xylene-soluble components at 1.3.25 ° C (CXS)
The value of CXS was obtained by 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 prepare a solution, and then left at 25 ° C. for 12 hours. Then, the precipitated polymer is filtered off, p-xylene is evaporated from the filtrate, and dried under reduced pressure at 100 ° C. for 12 hours to recover the xylene-soluble component at 25 ° C. The ratio [% by weight] of the weight of the recovered component to the weight of the charged sample is defined as CXS.
1.4. 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 reached 1,000,000 was determined. The specific measurement method, analysis method, and calculation method are as described above.
1.5. Strain hardening degree (λmax)
Stretch viscosity was measured using Ares manufactured by Rheometrics, and the strain hardening degree (λmax) was determined from the result. The specific measurement method and calculation method are as described above.

1.6. Isotactic triad fraction (mm fraction), presence or absence of long chain branching Using JEOL Ltd., GSX-400, FT-NMR, as described above, paragraphs [0025] to [0025] of JP-A-2009-275207. 0065] was measured by the method described. The unit of mm fraction is%.
1.7. Melting point:
Using a differential operating calorimeter (DSC), once raise the temperature to 200 ° C to erase the heat history, then lower the temperature to 40 ° C at a temperature lowering rate of 10 ° C / min, and then raise the temperature again to 10 ° C / min. The temperature at the top of the endothermic peak was taken as the melting point.

1.8. Molecular weight distribution Mw / Mn and Mz / Mn:
It was determined by the following GPC measurement.
-Device: Waters GPC (ALC / GPC 150C)
-Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
-Column: Showa Denko AD806M / S (3 in series)
-Mobile phase solvent: orthodichlorobenzene (ODCB)
・ Measurement temperature: 140 ℃
-Flow velocity: 1.0 ml / min
・ Injection amount: 0.2 ml
-Sample preparation: As a sample, prepare a 1 mg / mL solution using ODCB (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.
The conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve prepared in advance using standard polystyrene (PS). The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000
A calibration curve is created by injecting 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. For the calibration curve, a cubic equation obtained by approximating with the least squares method is used.
The following numerical values are used for the viscosity formula [η] = K × Mα used for conversion to the molecular weight.
PS: K = 1.38 × 10-4, α = 0.7
PP: K = 1.03 × 10-4, α = 0.78

1.9. Ratio of propylene (co) polymer (Y-1) and propylene-ethylene copolymer (Y-2), ethylene content in Y-2 Combination of cross fractionation method and FT-IR method described in the specification. It was decided by the method of.

1.10. Intrinsic viscosity of propylene-ethylene copolymer (Y-2) 1.3. The intrinsic viscosity was measured using the CXS component of the propylene-based block copolymer (Y) obtained by the method described in 1. The intrinsic viscosity was measured using an Ubbelohde type capillary viscometer at a temperature of 135 ° C. and a decalin solvent.

1.11. Characteristic evaluation of foamed sheet The characteristic evaluation of foamed sheet was carried out by the following method.
1.11.1. Density A test piece was cut out from the foam sheets obtained in Examples and Comparative Examples, and the weight (g) of the test piece was divided by the volume (cm ³ ) obtained from the external dimensions of the test piece. The density was determined by measuring according to JIS K7222.
1.12. Foaming Magnification The value obtained by dividing the polypropylene resin density of 0.9 g / cm ³ by the density of the foamed sheet test piece was defined as the foaming magnification.
1.13. Appearance evaluation of sheet The appearance evaluation of the foamed sheet was evaluated based on the following criteria for the polypropylene-based resin foamed sheets obtained in each Example and Comparative Example.
⊚: Smooth with very few thickness spots. Beautiful with no local irregularities on the surface. The bubble shape is fine.
◯: There are few thickness spots. There is almost no local unevenness on the surface. The bubble shape is uniform.
Δ: There is thickness unevenness. The bubble shape is uniform, but local irregularities are seen.
X: There are many thickness spots. Consolidation of bubbles is seen, and there are local recesses (sinks).

1.14. Foam layer bubble diameter A 25 mm square sample was cut out from the foam sheets obtained in Examples and Comparative Examples. A stereomicroscope (manufactured by Nikon: SMZ-1000-2 type) is used to magnify and project the cross section of the foam layer, and the bubble diameters in the extrusion direction cross section and its vertical cross section are calculated from the number of bubbles and the bubble diameter in the cross section. The average value was taken as the foam layer bubble diameter of the foam layer.
1.15. Continuous bubble ratio A test piece was cut out from the foam sheets obtained in Examples and Comparative Examples, and measured using an air pycnometer (manufactured by Tokyo Science Co., Ltd.) according to the method described in ASTM D2856.

2. 2. Materials used 2.1. Polypropylene (X)
The polypropylenes X1 to X3 obtained in Production Examples 1 to 3 below and the homopolypropylene Daploy (TM) WB140HMS: X4 manufactured by Borealis were used as polypropylene (X).

[Manufacturing Example 1: Manufacture of polypropylene (X1)]
<Synthesis of catalyst component [A-1]>
Dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl}] Hafnium synthesis: (component [A-1] (complex 1) ) Synthesis):
(I) Synthesis of 4- (4-i-propylphenyl) inden 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 (DME) was added. 0.28 mol) and 100 ml of water were added, 13 g (67 mmol) of 4-bromoinden 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 separating funnel, and extracted with diisopropyl ether. The ether layer was washed with saturated brine and dried over sodium sulfate. The sodium sulfate was filtered, the solvent was distilled off under reduced pressure, and the residue was purified on a silica gel column to obtain 15.4 g (yield 99%) of a colorless liquid of 4- (4-i-propylphenyl) inden.

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

Synthesis of (iii) 2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) inden To a 500 ml glass reaction vessel, 6.7 g (82 m1 mol) of 2-methylfuran and 100 ml of DME were added. , Cooled to −70 ° C. in a dry ice-methanol bath. 1 here
.. 51 ml (81 mmol) of a 59 mol / L n-butyllithium-n-hexane solution was added dropwise, and the mixture was stirred as it was for 3 hours. The mixture was cooled to −70 ° C., and a solution of 20 ml (87 mmol) of triisopropylborate and 50 ml of DME was added dropwise thereto. After the dropping, the mixture was stirred overnight while gradually returning to room temperature.
After hydrolyzing by adding 50 ml of distilled water to the reaction solution, a solution of 223 g of potassium carbonate and 100 ml of water and 19.8 g (63 mmol) of 2-bromo-4- (4-i-propylphenyl) indene were added in this order at 80 ° C. The mixture was heated and reacted for 3 hours while removing low boiling water.
After allowing to cool, the reaction solution was poured into 300 ml of distilled water, transferred to a separating funnel and extracted three times with diisopropyl ether. The ether layer was washed with saturated brine and dried over sodium sulfate. The sodium sulfate was filtered, the solvent was evaporated under reduced pressure, and the residue was purified on a silica gel column. 19.6 g (19.6 g) of a colorless liquid of 2- (2-methyl-5-furyl) -4- (4-i-propylphenyl) indene. Yield 99%) was obtained.

(Iv) Synthesis of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane In a 500 ml glass reaction vessel, 2- (5-methyl-2-) 9.1 g (29 mmol) of frill) -4- (4-i-propylphenyl) indene and 200 ml of THF were added, and the mixture was cooled to −70 ° C. in a dry ice-methanol bath. 17 ml (28 mmol) of a 1.66 mol / L n-butyllithium-hexane solution was added dropwise thereto, and the mixture was stirred as it was for 3 hours. The mixture was cooled to −70 ° C., 0.1 ml (2 mmol) of 1-methylimidazole and 1.8 g (14 mmol) of dimethyldichlorosilane were added in this order, and the mixture was stirred overnight while gradually returning to room temperature.
Distilled water was added to the reaction solution, the mixture was transferred to a separatory funnel, washed with brine until neutral, sodium sulfate was added, and the reaction solution was dried. Sodium sulfate was filtered, the solvent was evaporated under reduced pressure, purified on a silica gel column, and the yield of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane was reduced. 8.6 g (yield 88%) 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, Add 8.6 g (13 mmol) of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane and 300 ml of diethyl ether, and in a dry ice-methanol bath at -70 ° C. Cooled to. To this, 15 ml (25 mmol) of a 1.66 mol / L n-butyllithium-n-hexane solution was added dropwise, and the mixture was 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 mixture was cooled to −70 ° C. in a dry ice-methanol bath. To this, 4.0 g (13 mmol) of hafnium tetrachloride was added. Then, the mixture was stirred overnight while gradually returning to room temperature.
The solvent was evaporated under reduced pressure, recrystallized from dichloromethane-hexane, and dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl. )}] 7.6 g (65% yield) of the racemic hafnium was obtained as yellow crystals.
The identification values of the obtained racemic mixture by 1H-NMR are described below.
^{1 1} H-NMR (C ₆ D ₆ ) identification result Racemic: δ0.95 (s, 6H), δ1.10 (d, 12H), δ2.08 (s, 6H), δ2.67 (m, 2H) , Δ5.80 (d, 2H), δ6.37 (d, 2H), δ6.74 (dd, 2H), δ7.07 (d, 2H), δ7.13 (d, 4H), δ7.28 ( s, 2H), δ7.30 (d, 2H), δ7.83 (d, 4H).

<Synthesis of catalyst component [A-2]>
rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] Hafnium synthesis: (Synthesis of component [A-1] (complex 2)):
The synthesis of rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium is the method described in Example 1 of JP-A-11-240909. It was carried out in the same manner as above.

<Synthesis of catalyst component (B)>
(I) Chemical treatment of ion-exchangeable layered silicate Add 96% sulfuric acid (668 g) to 2,264 g of distilled water in a separable flask, and then use montmorillonite (Mizusawa Industrial Chemicals, Inc. Benclay SL: average particle size 19 μm) as the layered silicate. ) 400 g was added. The slurry was heated at 90 ° C. for 210 minutes. After adding 4,000 g of distilled water to this reaction slurry, filtration was performed to obtain 810 g of a cake-like solid.
Next, 432 g of lithium sulfate and 1,924 g of distilled water were added to a separable flask to prepare an aqueous solution of lithium sulfate, and the entire amount of the cake-like solid was put into the flask. The slurry was reacted at room temperature for 120 minutes. After adding 4 L of distilled water to this slurry, it was filtered, further washed with distilled water to pH 5 to 6, and filtered to obtain 760 g of a cake-like solid.
The obtained solid was pre-dried at 100 ° C. under a nitrogen stream for a whole day and night, coarse particles of 53 μm or more were removed, and further dried under reduced pressure at 200 ° C. for 2 hours to obtain 220 g of chemically treated smectite.
The obtained solid was pre-dried at 100 ° C. under a nitrogen stream for a whole day and night, coarse particles having a diameter of 53 μm or more were removed, and further dried under reduced pressure at 200 ° C. for 2 hours to obtain 220 g of chemically treated smectite.
The composition of this chemically treated smectite is Al: 6.45% by weight, Si: 38.30% by weight, Mg: 0.98% by weight, Fe: 1.88% by weight, Li: 0.16% by weight. Al / Si = 0.175 [mol / mol].

<Preparation of prepolymerization catalyst 1>
i) Catalyst preparation and prepolymerization 20 g of the chemically treated smectite obtained from the above catalyst component (B) is placed in a three-necked flask (volume 1 L), and heptane (132 mL) is added to prepare a slurry, which is triisobutyl. Add aluminum (25 mmol: 68.0 mL of heptane solution with a concentration of 143 mg / mL), stir for 1 hour, wash with heptane until the residual liquid ratio becomes 1/100, and add heptane so that the total volume becomes 100 mL. It was.
Further, in another flask (volume 200 mL), rac-dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) obtained by the synthesis of the above-mentioned catalyst component [A-1]] ) -4- (4-i-propylphenyl) indenyl}] Hafnium (180 μmol) is dissolved in toluene (42 mL) (solution 1), and further in another flask (volume 200 mL), the above-mentioned catalytic component [A -2] Rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium (120 μmol) obtained in the synthesis was dissolved in toluene (18 mL). (Solution 2).
After adding triisobutylaluminum (0.84 mmol: 1.2 mL of heptane solution having a concentration of 143 mg / mL) to a 1 L flask containing the above chemically treated smectite, the above solution 1 was added and the mixture was stirred at room temperature for 20 minutes. Then, triisobutylaluminum (0.36 mmol: 0.50 mL of a heptane solution having a concentration of 143 mg / mL) was further added, the above solution 2 was added, and the mixture was stirred at room temperature for 1 hour.
Then 338 mL of heptane was added and the 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 40 ° C. for 4 hours. Then, the propylene feed was stopped and residual polymerization was carried out for 1 hour. After removing the supernatant of the obtained catalyst slurry by decantation, triisobutylaluminum (6 mmol: 17.0 mL of heptane solution having a concentration of 143 mg / mL) was added to the remaining portion, and the mixture was stirred for 5 minutes.
The solid was dried under reduced pressure for 1 hour to obtain 60.0 g of a dry prepolymerization catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 2.00 g / g-catalyst.
Hereinafter, this is referred to as "prepolymerization catalyst 1".

<Polymerization>
After sufficiently replacing the inside of the stirring autoclave having an internal volume of 200 liters with propylene, 40 kg of fully dehydrated liquefied propylene was introduced.
After adding 6.8 NL (0.61 g) of hydrogen and 0.47 L of triisobutylaluminum (0.12 mol: 0.47 L of heptane solution having a concentration of 50 g / L) to this, the internal temperature was raised to 70 ° C. Next, 2.4 g of the prepolymerized catalyst 1 (by weight excluding the prepolymerized polymer) was press-fitted with argon to initiate polymerization, and the internal temperature was maintained at 70 ° C.
After 2 hours, 100 ml of ethanol was press-fitted, unreacted propylene was purged, and the inside of the autoclave was replaced with nitrogen to terminate the polymerization.
The obtained polymer was dried under a nitrogen stream at 90 ° C. for 1 hour to obtain 16.9 kg of polymer PP-1. The catalytic activity was 7.0 kg-PP / g-catalyst.

<Granulation>
1,3,5-Tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (trade name) with respect to 100 parts by weight of the polypropylene polymer PP-1 obtained by the above polymerization. : Cyanox1790, manufactured by Nippon Cytec Industries Co., Ltd.) 0.05 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Co., Ltd.) 0.10 parts 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 Co., Ltd.) 0.03 parts by weight, stearate amide 0.09 parts by weight, Was mixed and thoroughly stirred, and then melt-kneaded at 220 ° C. using a twin-screw extruder (KZW25TW-45MG-NH manufactured by Technobel Co., Ltd.), and the extruded strands were cut and pelletized to obtain polypropylene (X1). ..
The results of analysis of the obtained polypropylene X1 are shown in Table 1. As a result of ¹³ C-NMR measurement, it was confirmed that this polypropylene X1 had a long chain branch. Further, the branching index g'is 0.88, which is smaller than 1, indicating that the polypropylene X1 has a long-chain branching.

[Manufacturing Example 2: Manufacture of polypropylene (X2)]
<Polymerization>
The polymerization operation was carried out in the same manner as in Production Example 1 above except that the amount of hydrogen was 8.2 NL (0.73 g) to obtain 19.9 kg of polymer PP-2. The catalytic activity was 8.3 kg-PP / g-catalyst.
<Granulation>
Using the polymer PP-2 obtained by the above polymerization, granulation was carried out in the same manner as in Production Example 1 to obtain polypropylene X2.
The results of analysis of the obtained polypropylene X2 are shown in Table 1.

[Manufacturing Example 3: Production of Polypropylene (X3)]
<Polymerization>
The polymerization operation was carried out in the same manner as in Production Example 1 above except that the amount of hydrogen was 9.7 NL (0.87 g) to obtain 23.1 kg of polymer PP-3. The catalytic activity was 9.6 kg-PP / g-catalyst.
<Granulation>
Using the polymer PP-3 obtained by the above polymerization, granulation was carried out in the same manner as in Production Example 1 to obtain polypropylene X3.
The results of analysis of the obtained polypropylene X3 are shown in Table 1.

2.2. Propylene block copolymer (Y)
Y1 and Y2 obtained in Production Examples 4 and 5 below were used as the polypropylene-based block copolymer (Y). The properties are summarized in Table 2.
[Production Example 4: Production of Propylene Block Copolymer (Y1)]
1. 1. Production of solid catalyst component A 10 liter autoclave equipped with a stirrer was sufficiently replaced with nitrogen, and 2 liters of purified toluene was introduced. To this, at room temperature, 200 g of diethoxymagnesium Mg (OEt) ₂ and 1 liter of titanium tetrachloride were added. The temperature was raised to 90 ° C. and 50 ml of -n-butyl phthalate was introduced. Then, the temperature was raised to 110 ° C. and the reaction was carried out for 3 hours. The reaction product was thoroughly washed with purified toluene.
Then, purified toluene was introduced to adjust the total liquid volume to 2 L. 1 liter of titanium tetrachloride was added at room temperature, the temperature was raised to 110 ° C., and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Further, using purified n-heptane, toluene was replaced with n-heptane to obtain a slurry of solid catalyst components.
A part of this slurry was sampled and dried. As a result of analysis, the titanium content of the solid catalyst component was 2.7% by weight, and the magnesium content was 18% by weight. The average particle size of the solid catalyst component was 33 μm.

Next, an autoclave having a capacity of 20 liters equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the slurry of the solid catalyst component was introduced as a solid catalyst component. Purified n-heptane was introduced to adjust the concentration of the solid catalyst component to 25 g / liter. 50 mL of silicon tetrachloride SiCl ₄ was added, and the reaction was carried out at 90 ° C. for 1 hour. The reaction product was thoroughly washed with purified n-heptane.
Then, purified n-heptane was introduced to adjust the liquid level to 4 liters. Here, dimethyl divinyl silane 30 ml, t-butyl methyl dimethoxy silane _{(t-C 4 H 9)} (CH 3) Si (OCH 3) 2 to 30 ml, the n- heptane dilution of triethylaluminum _Et 3 Al Et ₃ 80 g of Al was added, and the reaction was carried out at 40 ° C. for 2 hours. The reaction product was thoroughly washed with purified n-heptane, and a part of the obtained slurry was sampled and dried. As a result of analysis, the solid component contained 1.2% by weight of titanium and 8.8% by weight of (t-C ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) ₂ .

Prepolymerization was carried out by the following procedure using the solid component obtained above.
Purified n-heptane was introduced into the above slurry to adjust the concentration of the solid component to 20 g / liter. After cooling the slurry to 10 ° C., and 10g added n- heptane dilution of triethylaluminum _Et 3 Al as _Et 3 Al, were added over 4 hours propylene 280 g. After the supply of propylene was finished, the reaction was continued for another 30 minutes.
The gas phase was then thoroughly replaced with nitrogen and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried to obtain a solid catalyst component (catalyst 1). This solid catalyst component (catalyst 1) contained 2.5 g of polypropylene per 1 g of the solid component. As a result of analysis, in the portion of the solid catalyst component (catalyst 1) excluding polypropylene, titanium was 1.0% by weight, and (t-C ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) ₂ was 8.2. It was contained in% by weight.

2. 2. Production of propylene-based block copolymer Polymerization was carried out using a continuous reactor consisting of two fluidized bed reactors with an internal volume of 2000 liters connected together.
First, in the first reactor, the polymerization temperature was 65 ° C., the partial pressure of propylene was 1.8 MPa (absolute pressure), and hydrogen as a molecular weight control agent was continuously added so that the molar ratio of hydrogen / propylene was 0.015. At the same time, the above catalyst 1 was supplied at 4.0 g / hr of triethylaluminum so that the polymerization rate of the monomer was 16 kg / hr. The powder (crystalline propylene polymer) polymerized in the first reactor is continuously withdrawn at a withdrawal rate of 16 kg / hr so that the amount of powder held in the reactor is 40 kg, and is continuously withdrawn into the second reactor. Transferred (first stage polymerization step).

Next, in the second reactor, propylene and ethylene were continuously supplied so that the monomer pressure was 1.5 MPa and the molar ratio of ethylene / propylene was 0.29 at a polymerization temperature of 70 ° C. , Hydrogen as a molecular weight control agent is continuously supplied so as to have a molar ratio of hydrogen / propylene of 0.0008, and ethyl alcohol is supplied to the first reactor at 1.17 with respect to triethylaluminum. It was supplied so as to double the molar amount.
The powder polymerized in the second reactor is continuously extracted into the vessel so that the amount of powder held in the reactor becomes 60 kg, and nitrogen gas containing water is supplied to stop the reaction, and both the propylene-ethylene block and the propylene-ethylene block are used. A polymer was obtained (second stage polymerization step).

0.2 parts by weight of "IRGASTAB FS 301 FF" (manufactured by BASF), 1,3,5-tris (2,) as an antioxidant with respect to 100 parts by weight of the obtained propylene / ethylene block copolymer powder. 6-Dimethyl-3-hydroxy-4-talsialbutylbenzoyl) isocyanate (manufactured by Songwon, trade name: SONGNOX1790) 0.1 part by weight, 3,9-bis (2,6-di-tert-butyl-4- Methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] Undecane (manufactured by ADEKA, trade name: Adecastab PEP-36) 0.05 parts by weight, calcium stearate as a neutralizing agent 0.03 part by weight was added and mixed with a super mixer (manufactured by Kawata Co., Ltd.) for 5 minutes.

Using the obtained blend, a propylene-based block copolymer (Y1) was obtained by an underwater cut granulation method under the following equipment and conditions.
-Two-screw extruder (KZW25TW-45MG-NH manufactured by Technobel)
-Diameter 30 mm, L / D = 25 (PMS30-25 manufactured by IG)
・ Screw: Full flight CR2.0, Feed groove depth 4mm + Darmage ・ Screw rotation speed: 60rpm
-Set temperature: hopper sewage cooling, C1 to C4 220, 200, 200, 200 ° C.
・ Die: Strand die ・ Processing rate of granules: 200kg / hr
・ Cooling water temperature: 43 ° C
-Screen mesh: BMT140ZZ (obtained from Ishikawa Wire Net Co., Ltd., special twill weave)

[Production Example 5: Production of Propylene Block Copolymer (Y2)]
1. 1. Of Production Example 4 of the solid catalyst component of the solid catalyst component _{preparation, (t-C 4 H 9} ) (CH 3) Si (OCH 3) instead of _{2, (i-Pr) 2} Si (OCH 3) 2 Was used, but the procedure was carried out according to Production Example 4.

2. 2. Production of propylene-based block copolymer Using the catalyst prepared above, the molar ratio of hydrogen / propylene in the first-stage polymerization was 0.016 according to the procedure for producing the propylene / ethylene block copolymer of Production Example 4 above. In addition, the amount of ethyl alcohol input was first set so that the molar ratio of hydrogen / propylene in the second stage polymerization was 0.00015 and the molar ratio of propylene and ethylene was 0.26 in ethylene / propylene. A propylene / ethylene block copolymer was produced at 1.19 times the molar amount of triethylaluminum supplied to the reactor, and granulation was carried out in the same manner as in Production Example 4 to obtain a propylene-based block copolymer (Y2). Got

2.3. Polypropylene resin composition A blend of polypropylene (X) and a propylene-based block copolymer (Y). It is summarized in Table 3.

[Manufacturing Example 6]
Polypropylene X3 and propylene block copolymer Y1 are blended at 90:10 (weight ratio), stirred sufficiently, melt-kneaded under the following conditions using a single-screw extruder, and the extruded strands are cut with a fan cutter. And pelletized to obtain a polypropylene resin composition A.
・ Extruder: Diameter 30 mm, L / D = 25 (IKG PMS30-25)
・ Screw: Full flight CR = 2.0, Feed groove depth 4 mm + Darmage screw Rotation speed: 60 rpm
-Set temperature: hopper sewage cooling, C1 / C2 / C3 / C4 = 220/200/200/200 ° C
・ Die: 1mm diameter strand die

[Manufacturing Example 7]
A polypropylene resin composition B was obtained in the same manner as in Production Example 6 except that polypropylene X3 and propylene block copolymer Y1 were set at 70:30 (weight ratio).

[Manufacturing Example 8]
A polypropylene resin composition C was obtained in the same manner as in Production Example 6 except that polypropylene X3 and propylene block copolymer Y1 were set to 10:90 (weight ratio).

[Manufacturing Example 9]
A polypropylene resin composition D was obtained in the same manner as in Production Example 7 except that the propylene-based block copolymer was Y2.

3. 3. Preparation of non-stretched film and counting of the number of gels [Example 1]
Using the polypropylene resin composition A, a film having a thickness of 25 μm was produced by a CF-350 type film molding apparatus manufactured by Create Plastic Co., Ltd., and the number of gels of the film was counted by a CCD defect detector (SCANTEC7000) manufactured by Nagase & Co., Ltd. did. The details are shown below.
Polypropylene resin composition on a CR45-25 type extruder (caliber 40 mm, L / D = 25) having a full flight metering type screw and a straight manifold type T die (350 type film die) with a width of 350 mm attached to the tip. Insert A. The setting condition of the extruder was the condition (3) shown in Table 4, and the screw rotation speed was 55 rpm. The molten resin from the T-die was picked up by a double chill roll type film picker (CR-400 type) in which the cooling roll temperature was set to 40 ° C. to obtain a non-stretched film.
The number of gels was counted using the above-mentioned defect detector at the center of the film between the taker and the winder. The inspection width and inspection length were 10 mm width and 5 m length (inspection area 0.05 m ² ), respectively, and the number of inspections was 600 times. The average value of the values obtained for each size category was converted into a unit area and calculated. The results are shown in Table 5.

[Example 2]
A film was prepared in the same manner as in Example 1 except that B was used as the polypropylene resin composition, and the number of gels was calculated. The results are shown in Table 5.

[Example 3]
A film was prepared in the same manner as in Example 1 except that C was used as the polypropylene resin composition and the setting condition of the extruder was the condition (2) shown in Table 4, and the number of gels was calculated. The results are shown in Table 5.

[Comparative Example 1]
A film was prepared in the same manner as in Example 1 except that D was used as the polypropylene resin composition, and the number of gels was calculated. The results are shown in Table 5.

[Example 4]
A film was prepared in the same manner as in Example 1 except that polypropylene X1 was used instead of the polypropylene resin composition and the setting condition of the extruder was the condition (1) shown in Table 4, and the number of gels was calculated. .. The results are shown in Table 6.

[Example 5]
A film was prepared in the same manner as in Example 1 except that polypropylene X2 was used and the setting condition of the extruder was the condition (2) shown in Table 4, and the number of gels was calculated. The results are shown in Table 6.

[Example 6]
A film was prepared in the same manner as in Example 1 except that polypropylene X3 was used and the setting condition of the extruder was the condition (3) shown in Table 4, and the number of gels was calculated. The results are shown in Table 6.

[Comparative Example 2]
A film was prepared in the same manner as in Example 4 except that polypropylene X4 was used. And the like holes in the film is free in the gel due to calculate the number of gels using the value of the largest test area test area of 0.05 m ² could be continuous measurement because it could not be secured (0.015 m ²⁾ .. The results are shown in Table 6.

4. Manufacture and evaluation of foam sheet using T-die [Example 7]
100 parts by weight of polypropylene resin composition A and 0.5 part by weight of a chemical foaming agent (trade name: Hydrocerol CF40E-J, manufactured by Nippon Boehringer Ingelheim Co., Ltd.) as a bubble adjusting agent are uniformly stirred and mixed by a ribbon blender, and a barrel is used. It was put into a single-screw extruder having a barrel hole for injecting a physical foaming agent in the middle of. While heating and melting in the pre-stage of the extruder to plasticize and decompose the bubble conditioner, 0.35 parts by weight of liquefied carbon dioxide is injected and kneaded with a high pressure pump to 100 parts by weight of the mixture to foam polypropylene resin. After the molding material was used, the polypropylene resin foam molding material was rapidly cooled in the subsequent stage of the extruder and extruded from a T-die having a width of 750 mm and a lip width of 0.4 mm via a feed block.
At this time, using two single-screw extruders, a propylene-based block copolymer resin (manufactured by Japan Polypropylene Corporation, grade name "BC3BRF", MFR = 12 g / 10 minutes) was heated, melted and extruded on both surfaces. The layers were laminated to form a multi-layer foamed sheet having a two-kind, three-layer structure composed of a non-foamed layer, a foamed layer, and a non-foamed layer. One side of the extruded multilayer foam sheet was first cooled by a roll with a diameter of 80 mm installed near the die, then both sides were cooled by three rolls with a diameter of 100 mm installed after that, and the sheet was picked up at a constant speed by a pinch roll. ..
The operating conditions of each extruder are as follows.
・ Extruder (foam layer)
Caliber: 65 mm, L / D = 50, Physical foaming agent injection port: L / D = 20 position Screw rotation speed: 75 rpm
Set temperature: C1 / C2-C4 / C5 / C6 to C9 = 180/240/190/175 ° C.
Discharge rate: Approximately 70 kg / h
・ Extruder (non-foaming layer)
Caliber: 40 mm, L / D = 28
Screw rotation speed: 50 rpm
Set temperature: C1 / C2 / C3 / C4 = 180/230/190/180 ° C
・ Feed block temperature: 175 ℃
・ Die temperature: 175 ℃
・ Cooling roll temperature: 15 ℃
・ Pick-up speed: 4.5m / min
The obtained multilayer foamed sheet has a layer structure having a thickness ratio of non-foamed layer: foamed layer: non-foamed layer of 4: 92: 4, a density of 0.30 g / cm ³ , and a foamed layer bubble diameter of 80 μm. It had a fine bubble structure with an open cell ratio of 8% and had a good appearance. The evaluation results of the foam sheet are shown in Table 7.

[Example 8]
A foamed sheet was produced in the same manner as in Example 7 except that the polypropylene resin composition was B.
The obtained multilayer foamed sheet has a layer structure having a thickness ratio of non-foamed layer: foamed layer: non-foamed layer of 4: 92: 4, a density of 0.30 g / cm ³ , and a foamed layer bubble diameter of 90 μm. It had a fine cell structure with an open cell ratio of 5% and had a good appearance. The evaluation results of the foam sheet are shown in Table 7.

[Example 9]
A foamed sheet was produced in the same manner as in Example 7 except that the polypropylene resin composition was C.
The obtained multilayer foamed sheet has a layer structure having a thickness ratio of non-foamed layer: foamed layer: non-foamed layer of 4: 92: 4, a density of 0.31 g / cm ³ , and a foamed layer bubble diameter of 120 μm. It had a dense cell structure with an open cell ratio of 7% and had a good appearance. The evaluation results of the foam sheet are shown in Table 7.

[Example 10]
A foamed sheet was produced in the same manner as in Example 8 except that the non-foamed layer was not co-extruded to form a foamed single layer sheet. The obtained single-layer foamed sheet had a density of 0.29 g / cm ³ , a foamed layer bubble diameter of 120 μm, and an open cell ratio of 14%, and had a good appearance. The evaluation results of the foam sheet are shown in Table 7.

[Comparative Example 3]
A foamed sheet was produced in the same manner as in Example 7 except that the polypropylene resin composition was D. The obtained multilayer foamed sheet had a density of 0.37 g / cm ³ and a low foaming ratio, and an open cell ratio of 30%. The appearance of the foamed sheet was confirmed to have local irregularities that were thought to be caused by the gel in the foamed layer. The evaluation results of the foam sheet are shown in Table 7.

[Comparative Example 4]
A single-layer foamed sheet was produced in the same manner as in Example 10 except that the polypropylene resin composition was D. The obtained single-layer foamed sheet had a density of 0.41 g / cm ³ and a low foaming ratio, and an open cell ratio of 44%. As for the appearance of the foamed sheet, roughness that seems to be caused by the gel of the foamed layer was confirmed on the entire surface. The evaluation results of the foam sheet are shown in Table 7.

5. Manufacture and evaluation of foamed sheet using a circular die [Example 11]
100 parts by weight of polypropylene X1 and 0.5 part by weight of a chemical foaming agent (trade name: Hydrocerol CF40E-J, manufactured by Nippon Boehringer Ingelheim Co., Ltd.) as a bubble adjusting agent are uniformly stirred and mixed with a ribbon blender, and the screw diameter is Was put into a tandem extruder of 40 mm and 50 mm, respectively. A high-pressure pump pumps 0.99 parts by weight of isobutane with respect to 100 parts by weight of the mixture while heating and melting the resin to plasticize it by setting the cylinder set temperature of the first-stage extruder to 230 ° C. and decomposing the bubble conditioner. After injecting and kneading with a polypropylene resin foam molding material, the second-stage extruder was quickly cooled at a set temperature of 190 ° C, and a circular die attached to the tip of the extruder (set temperature 175 ° C, diameter 50 mm). , Gap = 0.75 mm), the polypropylene resin foam molding material was extruded into the atmosphere and foamed. The rotation speed of the first-stage extruder was 90 rpm, and the rotation speed of the second-stage extruder was 10 rpm.
The foam extruded from the die was passed through a cooling mandrel having an outer diameter of 120 mm through which water was passed at a water temperature of 10 ° C. to cool the inner surface, and at the same time, air was blown from an air ring attached near the die to cool the outer surface. Then, after cutting open with a rotor cutter to form a sheet, the thickness was adjusted at the speed of a take-up roll, and the sheet was taken up by a pinch roll and a take-up roll. The obtained foamed sheet had a density of 0.16 g / cm ³ , a foamed layer bubble diameter of 100 μm, an open cell ratio of 10%, less corrugation, and a good appearance. The evaluation results of the obtained foam sheet are shown in Table 8.

[Example 12]
A foamed sheet was produced in the same manner as in Example 11 except that polypropylene was set to X2 and the set temperature of the second-stage extruder was 180 ° C. The obtained foamed sheet had a density of 0.16 g / cm ³ , a foamed layer bubble diameter of 120 μm, an open cell ratio of 7%, less corrugation, and a good appearance. The evaluation results of the obtained foam sheet are shown in Table 8.

[Example 13]
A foam sheet is produced by the same method as in Example 11 except that the injection amount of polypropylene is X3 and the injection amount of isobutane is 0.80 parts by weight with respect to the polypropylene resin foam molding material and the set temperature of the second stage extruder is 175 ° C. did. The obtained foamed sheet had a density of 0.20 g / cm ³ , a foamed layer bubble diameter of 120 μm, an open cell ratio of 10%, no corrugation, and had a good appearance. The evaluation results of the obtained foam sheet are shown in Table 8.

[Comparative Example 5]
A foamed sheet was produced in the same manner as in Example 11 except that polypropylene was used as D. The obtained foamed sheet had a density of 0.20 g / cm ³ , a foamed layer bubble diameter of 100 μm, an open cell ratio of 10%, and no corrugation was generated, but local unevenness due to gel was observed. Table 8 shows the evaluation results of the obtained foamed sheet.

By comparison between Examples and Comparative Examples, the polypropylene resin for foam molding and the polypropylene resin composition for foam molding according to the present invention have excellent foaming characteristics, high thermoforming suitability for foam sheets, and excellent appearance of the obtained container. It is clear that.

The polypropylene resin for foam molding and the polypropylene resin composition for foam molding according to the present invention have excellent foaming properties, high thermoforming suitability for foam sheets, and excellent appearance of the obtained container. It can be suitably used for food containers such as cups, vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery, and building materials, and has extremely high industrial value.

Claims (7)

In a method for producing a polypropylene resin foam molding material by blending 0.05 to 6.0 parts by weight of a foaming agent with respect to 100 parts by weight of the resin composition.
As the resin composition,
It contains 10 to 99% by weight of polypropylene (X) produced by macromer copolymerization using a combination of metallocene catalysts and 1 to 90% by weight of propylene-based block copolymer (Y) produced by step-growth polymerization.
Polypropylene (X) satisfies the following characteristics (X-i) to (X-iv),
Characteristic (X-i): Has a long chain branch.
Characteristic (X-ii): The melt tension (MT) measured at 230 ° C. is 3 to 25 g.
Characteristic (X-iii): Melt flow rate (MFR) exceeds 0.9 g / 10 minutes,
15 g / 10 minutes or less.
Characteristic (X-iv): 25 ° C. xylene-soluble component amount (CXS) is polypropylene (X)
It is less than 5 wt% of the total amount.
The propylene-based block copolymer (Y) may contain a comonomer of 10% by weight or less. The propylene (co) copolymer (Y-1) and the ethylene content are 11.0 to 38.0% by weight.
When the total amount of the propylene-based block copolymer (Y) is 100% by weight, (Y-1) is 50 to 99% by weight, and (Y-) is composed of the propylene-ethylene copolymer (Y-2).
2) is 1 to 50% by weight, and the MFR range of the propylene-based block copolymer (Y) is 2.1 to 170 g / 10 minutes.
230 measured melt tension at ° C. (MT) is prepared der Ru resin composition or 1g, from the resulting resin composition, the number of major diameter 0.5mm or more gel when the non-stretched film having a thickness of 25μm A method characterized by selecting a resin composition having 50 pieces / m ² or less. Method for producing a polypropylene resin foam molded article by extruding a foam molding material obtained by the manufacturing method according to claim 1. A method for producing a polypropylene resin laminated foam molded product by co-extruding the polypropylene resin foam molded product according to claim 2 and a non-foamed layer made of a thermoplastic resin composition. The method for producing a polypropylene resin laminated foam molded article according to claim 3, wherein the thermoplastic resin composition contains 50 parts by weight or less of an inorganic filler with respect to 100 parts by weight of the thermoplastic resin. A method for producing a molded product by thermoforming the polypropylene resin foam molded product or laminated foam molded product according to any one of claims 2 to 4. Manufacturing method of the claim injection molding a foam-molded material obtained by the manufacturing method according to claim 1, thermoformed molded article by subjecting to any one of the molding methods blow molding or bead foam molding. The method for producing a molded product according to any one of claims 2 to 4, which is in the form of a sheet.

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