JP2017066204A - Polypropylene resin for foam molding and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin excellent in repeating moldability while keeping good foam moldability and spreadability even after conducting extrusion granulation once.SOLUTION: There is provided a polypropylene resin for foam molding containing a propylene homopolymer having melting tensile force MTat 230°C of 3 g or more, and melting tensile force MTat 230°C after conducting extrusion granulation operation once at 230°C of 0.3 or more when MTis 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polypropylene resin composition, a foam molded article produced using the polypropylene resin composition, and a molded product thereof.

  One of the important molding methods for polypropylene is foam molding. Various molded products obtained by extrusion foaming and injection foaming have excellent properties such as heat insulation, sound insulation, cushioning and energy absorption, and are used in a wide range of applications. In recent years, weight reduction of materials and reduction of environmental load have become important development factors, and further improvement of foaming characteristics and the like is desired for the resin as a raw material.

  Since general polypropylene has a molecular structure that is linear and does not have a high molecular weight, it has a low melt tension and is difficult to perform foam molding. Therefore, various technological developments have been made to improve the melt tension of polypropylene. One of the representative methods is a method of introducing a long chain branch (LCB) by generating radicals with high-energy ionizing radiation or organic peroxide. Long chain branching refers to a branched structure of molecular chains having several tens or more carbon atoms and several hundred or more in molecular weight, and is considered to have an effect of improving melt tension. In addition, a macromonomer having a terminal unsaturated bond can be produced by polymerizing a monomer using a metallocene catalyst having a specific structure, and a long-chain branch can be formed by copolymerizing it with propylene. (Patent Document 1).

  As another method for improving the melt tension of polypropylene, there is a method of introducing a component having a very high molecular weight by multistage polymerization or prepolymerization, or blending a plurality of polypropylenes. Furthermore, balancing the melt tension and extensibility suitable for extrusion foaming has been studied by incorporating a specific impact copolymer such as a propylene-ethylene copolymer into a long-chain branched polypropylene (Patent Literature). 2, 3).

JP 2009-299029 A JP 2013-199643 A Japanese Patent Laying-Open No. 2015-40213

  Here, when a molded product is manufactured using a polypropylene resin for foam molding, it is inevitable that end materials are usually generated in portions other than the outer edge portion of the sheet or a portion used as a product during punching or thermoforming. The mill ends can be melted again and subjected to the molding process. However, as a result of investigations and examinations by the present inventors, it has been clarified that a resin once subjected to the foam molding process has a greatly reduced melt tension and cannot satisfy a sufficient foaming characteristic. In foam molding using a resin that cannot satisfy sufficient foaming characteristics, a large change in molding conditions is required every time it is reused, and the quality of the foam sheet or molded product may be deteriorated. If the resin used as a scrap material is not reused due to quality problems, such resin can only be discarded. Therefore, in consideration of the environment and cost, it is desired to improve the repetitive moldability of the foamed polypropylene resin in the production process of the molded product.

  In relation to physical properties such as melt tension of polypropylene resin and repetitive moldability, Patent Document 3 suggested a relationship with a branched chain of the polymer, but in extrusion foam molding, the balance between the melt tension of the resin and the stretchability. Therefore, to maintain these physical properties in a balanced manner, what kind of polypropylene resin is suitable, what kind of resin is effective in what kind of composition, and how much maintenance It was not clear whether the repetitive moldability could be satisfied by having the ratio. Therefore, it was necessary to search for a polypropylene resin having physical properties excellent in repetitive moldability.

  As a result of intensive studies to solve the above problems, the present inventors have found that the melt tension is not less than a specific value, and the change in melt tension after melting and solidifying once is in a specific range. By using a homopolymer, a polypropylene resin excellent in repetitive moldability has been obtained.

That is, the present invention relates to the inventions of the following items.
(1) When the melt tension MT _{0 at} 230 ° C. is 3 g or more, and the melt tension MT ₁ at 230 ° C. after performing the extrusion granulation operation at 230 ° C. once sets MT ₀ to 1 It is a polypropylene resin for foam molding containing a propylene homopolymer (X) of 0.3 or more.
(2) The propylene homopolymer (X) having a melt tension MT ₂ at 230 ° C. of 2 after the extrusion granulation operation at 230 ° C. is 0.2 or more when MT ₀ is 1 is included. The polypropylene resin for foam molding described in (1) above.
(3) The propylene homopolymer (X) having a melt tension MT ₃ at 230 ° C. of 3 after the extrusion granulation operation at 230 ° C. is 0.1 or more when MT ₀ is 1 is included. The polypropylene resin for foam molding described in (2) above.
(4) The melt flow rate MFR ₀ (230 ° C., 2.16 kg) of the propylene homopolymer (X) is in the range of 0.9 to 15 g / 10 min, and the extrusion granulation operation at 230 ° C. is 1 The melt flow rate MFR ₁ (230 ° C., 2.16 kg) of the propylene homopolymer after being repeated is 2 or less when MFR ₀ is 1, and the melt flow rate MFR ₁ is any one of (1) to (3) It is a polypropylene resin for foam molding as described.
(5) The polypropylene resin for foam molding according to any one of (1) to (4), wherein the propylene homopolymer (X) satisfies the following characteristics (Xi) to (X-iv):
Characteristic (Xi) Long chain branching.
Characteristic (X-ii) The melt tension at 230 ° C. is 3 to 25 g.
Characteristic (X-iii) Melt flow rate (230 ° C., 2.16 kg) is 0.9 to 15 g / 10 min.
Characteristic (X-iv) The amount of xylene-soluble components (CXS) at 25 ° C. is less than 5 wt% with respect to the total amount of the propylene homopolymer (X).
(6) Melting at 230 ° C. containing 10 to 99 wt% of the propylene homopolymer (X) and 1 to 90 wt% of the propylene-based block copolymer (Y) according to any one of (1) to (5) It is a polypropylene resin composition for foam molding having a tension of 1 g or more.
(7) The propylene-based block copolymer (Y) comprises a propylene (co) polymer (Y-1) and a propylene-ethylene copolymer (Y-2) which may contain 10% by weight or less of a comonomer, The polypropylene resin composition for foam molding according to (6), which satisfies the following characteristics (Yi) to (Yv).
Characteristic (Yi) When the total amount of the propylene-based block copolymer (Y) is 100 wt%, 50 to 99 wt% of the propylene (co) polymer (Y-1) which may contain a comonomer of 10 wt% or less, 1-50 wt% of propylene ethylene copolymer (Y-2) is contained.
Characteristic (Y-ii) Melt flow rate (230 ° C., 2.16 kg) is 0.1 to 200 g / 10 min.
The characteristic (Y-iii) melting point is 155 ° C. or higher.
Characteristic (Y-iv) The ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 38 wt%.
Property (Yv) The intrinsic viscosity of propylene-ethylene copolymer (Y-2) in decalin at 135 ° C. is 5.3 dl / g or more.
(8) The polypropylene resin composition for foam molding according to (7), wherein the propylene-based block copolymer (Y) is produced by a sequential polymerization method.
(9) 100 parts by weight of the polypropylene resin for foam molding according to any one of (1) to (5) or the polypropylene resin composition for foam molding according to any of (6) to (8) On the other hand, it is a polypropylene resin foam molding material containing 0.05 to 6.0 parts by weight of a foaming agent.
(10) A polypropylene resin foam molded article obtained by extruding the polypropylene resin foam molding material according to (9).
(11) A polypropylene resin laminated foam molded article obtained by co-extrusion of a foamed layer made of the polypropylene resin foam molded article according to (10) and a non-foamed layer made of a thermoplastic resin composition.
(12) The polypropylene resin laminated foam molded article according to (11), 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.
(13) The polypropylene resin foam molded article according to any one of (10) to (12), which is in the form of a sheet.
(14) A molded product obtained by thermoforming the polypropylene resin foam molded article or laminated foam molded article according to any one of (10) to (12).
(15) A molded product obtained by molding the polypropylene resin foam molding material according to (9) by any of injection molding, thermoforming, blow molding, or bead foam molding.
(16) Production of a foam sheet of the polypropylene resin for foam molding according to any one of (1) to (5) or the polypropylene resin composition for foam molding according to any of (6) to (8). Is for use.

  Even when the polypropylene resin for foam molding of the present invention is repeatedly subjected to the extrusion molding process, the decrease rate of the melt tension is small and the repeatability is excellent. In addition, since the rate of change in physical properties such as melt tension is small, a polypropylene resin molded product having a certain quality can be obtained without greatly changing the molding conditions.

It is a figure which shows the change of the melt tension by the repetitive shaping | molding of the polypropylene resin in an Example and a comparative example. It is a figure which shows the change of the melt flow rate by repeated shaping | molding of the polypropylene resin in an Example and a comparative example.

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

  The polypropylene resin for foam molding of the present invention is characterized by containing a propylene homopolymer having specific physical properties.

I. Propylene homopolymer (X)
<Melting tension (MT) and its maintenance ratio>
The propylene homopolymer (X) used for the polypropylene resin for foam molding has a melt tension MT _{0 at} 230 ° C. of 3 g or more and an extrusion granulation operation at 230 ° C. (hereinafter referred to as “repetitive extrusion operation”). The melt tension MT ₁ at 230 ° C. after the _{first step} is 0.3 or more when MT ₀ is 1. Hereinafter, represents the melt tension of the polymer after the repeated extrusion operation was carried out n times "MT _n", the ratio _MT n / MT ₀ of MT _n for MT _0, "MT retention after repeated extrusion number n times ”Or simply“ MT maintenance rate ”.

  The melt tension is one of the important factors for foam molding, and as the propylene homopolymer (X), the melt tension is 3 g or more. By setting the melt tension to 3 g or more, bubble breakage due to insufficient tension is less likely to occur when foam cells are formed. For this reason, it is possible to reduce the open cell ratio, which represents the ratio in which bubbles are continuously present in the foam. In addition, the cell diameter is reduced, and the cell size tends to be uniform. The upper limit of the melt tension is preferably 25 g or less, more preferably 24 g or less, still more preferably 20 g or less, and particularly preferably 15 g or less. By setting the upper limit of the melt tension within this range, the extensibility at the time of extrusion molding becomes good, and the appearance of a sheet, a film, a molded body and the like tends to be good. Further, it is possible to prevent bubble breakage due to poor spreading, suppress a reduction in foaming ratio, and simultaneously reduce the open cell ratio.

Since melt tension is an important factor for foam molding, maintaining melt tension even in a resin for repeated molding is important for maintaining foam moldability. Therefore, the propylene homopolymer (X) has an MT retention rate of 0.3 or more after one repeated extrusion.
If the MT retention rate after one repetitive extrusion is 0.3 or more, an increase in the open cell ratio, which is an index of foam moldability, is suppressed, and a decrease in the expansion ratio is reduced. Deterioration of product quality, such as appearance of the molded product, is less likely to occur. In addition, even when foam molding is performed by mixing a resin having a number of repeated extrusions of 1 with a newly prepared polypropylene resin (with a number of repeated extrusions of 0), a good molded product without greatly changing the molding conditions. Easy to get. In order to exhibit these effects better, the MT maintenance rate after one repetitive extrusion is preferably 0.35 or more, more preferably 0.4 or more.

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

In general, when foam molding is performed while recycling the mill ends, a resin that has been subjected to an extrusion operation twice or more can be included as well as a resin that is repeatedly extruded one time. For this reason, in the propylene homopolymer (X), it is preferable that the decrease in melt tension is small even after repeated extrusion operations are performed twice or more. Therefore, in the propylene homopolymer (X), it is preferable that the melt tension MT ₂ at 230 ° C. after repeating the extrusion operation twice is 0.2 or more when MT ₀ is 1.
When the MT maintenance ratio after the number of repeated extrusions of 2 is 0.2 or more, not only the product quality is less likely to deteriorate when the resin subjected to repeated extrusion operations alone is used, but the newly prepared resin Even when mixed, it is easy to produce a homogeneous product. In order to exhibit these effects better, the MT maintenance rate after two repeated extrusions is more preferably 0.25 or more, and further preferably 0.3 or more.

Further, in the propylene homopolymer (X), the melt tension MT ₃ at 230 ° C. after repeating the extrusion operation three times is preferably 0.1 or more when MT ₀ is 1. The MT maintenance rate after 3 times of repeated extrusions is more preferably 0.15 or more, and still more preferably 0.2 or more.

<Melt flow rate (MFR) and rate of change>
The propylene homopolymer (X) used for the polypropylene resin for foam molding has a melt flow rate MFR ₀ (230 ° C., 2.16 kg) in the range of 0.9 to 15 g / 10 min and melts at 230 ° C. When the MFR ₀ is 1, the melt flow rate MFR ₁ (230 ° C., 2.16 kg) of the propylene homopolymer after the repeated extrusion operation is preferably 2 or less. Hereinafter, the MFR when the repeated extrusion operation is performed n times is expressed as “MFR _n ”, and the ratio MFR _n / MFR ₀ of MFR _n and MFR ₀ is expressed as “MFR change rate after n times of repeated extrusion” or simply “MFR”. Sometimes referred to as the rate of change.

MFR is one of the basic factors in polypropylene molding. The melt flow rate MFR ₀ (230 ° C., 2.16 kg) of the propylene homopolymer before repeated extrusion operations is preferably in the range of 0.9 to 15 g / 10 min. Regarding the lower limit of the MFR of the propylene homopolymer, it is more preferably 1.0 g / 10 min or more, further preferably 1.1 g / 10 min or more, particularly preferably 1.2 g / 10 min or more, Most preferably, it is 1.5 g / 10 minutes or more. By setting the MFR within this range, the extensibility during extrusion molding is improved, and the appearance of sheets, films, molded articles, and the like is easily improved. Further, it is possible to prevent bubble breakage due to poor spreading and to reduce the open cell ratio. The upper limit of MFR is more preferably 14 g / 10 min or less, further preferably 13 g / 10 min or less, particularly preferably 12 g / 10 min or less, and most preferably 10 g / 10 min or less. By setting the MFR within this range, a portion that is excessively stretched during the formation of the foam cell is less likely to occur, and bubble breakage can be prevented and the open cell ratio can be lowered. In addition, the cell diameter is reduced and the cell size is likely to be uniform.

As a specific method for adjusting the MFR to the above range, a method of changing the amount of hydrogen added during polymerization can be mentioned. Since hydrogen acts as a chain transfer agent in the polymerization of propylene, if the amount of hydrogen added is increased, the MFR can be increased. Conversely, if the amount added is decreased, the MFR can be decreased. The value of MFR relative to the hydrogen concentration inside the polymerization tank varies depending on the catalyst used and other polymerization conditions, but the relationship between the hydrogen concentration and MFR is determined in advance according to the catalyst type and other polymerization conditions, and the desired MFR value is determined. The hydrogen concentration can be adjusted to a value.
Here, the MFR of the propylene homopolymer (X) is JIS K7210: 1999 “Plastics—Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics”, Condition M ( 230 ° C., 2.16 kg).

  Maintaining MFR in repetitive molding is an important factor for maintaining foam moldability of the resin, as is melt tension. Therefore, the propylene homopolymer (X) preferably has an MFR change rate of 2 or less after one repeated extrusion operation. If the MFR change rate after one repetitive extrusion operation is 2 or less, the extensibility during extrusion molding is maintained, and even if the extrusion operation is performed under the same conditions, the die pressure is less likely to occur. It is easy to obtain a sheet, a film, a molded article and the like having a good external appearance without causing any problems. The MFR change rate after one repetitive extrusion operation is more preferably 1.8 or less, and still more preferably 1.6 or less.

In addition, in the propylene homopolymer (X), the MFR ₂ of the propylene homopolymer after repeated extrusion operations is preferably 2.5 or less when MFR ₀ is 1. The MFR change rate after the number of repeated extrusions is 2 is more preferably 2.25 or less, and still more preferably 2 or less.

<Other characteristics of propylene homopolymer (X)>
The propylene homopolymer (X) preferably satisfies the following characteristics (Xi) to (X-iv).
Characteristic (Xi): Long chain branching.
Characteristic (X-ii): Melt tension measured at 230 ° C. is in the range of 3 to 25 g.
Characteristic (X-iii): Melt flow rate (230 ° C., 2.16 kg) is in the range of 0.9 to 15 g / 10 min.
Characteristic (X-iv): The proportion of components soluble in xylene at 25 ° C. (CXS) is less than 5 wt% with respect to the total amount of propylene homopolymer.

Among such propylene homopolymers (X), those satisfying the following characteristics (X-v) are more preferable, and those satisfying the following characteristics (X-vi) are more preferable.
Characteristic (Xv): The branching index g ′ at an absolute molecular weight Mabs of 1 million is 0.3 or more and less than 1.0.
Characteristic (X-vi): strain hardening degree (λ _max ) in measurement of extensional viscosity is 5-15.

I-1. Characteristic (Xi): Long chain branching The propylene homopolymer (X) preferably has long chain branching. Long chain branching refers to a branched structure of molecular chains having several tens of carbon atoms or more and several hundred or more in molecular weight. Distinguished from short chain branching.
There are several methods for examining whether or not there is a long chain branch in the propylene polymer, but those based on the rheological properties of the resin as shown in the properties (X-ii) and (X-vi) are easily used. As a stricter identification method, as shown in the characteristic (Xv), there are a method using the relationship between the molecular weight and the viscosity, a method using ¹³ C-NMR, and the like. For the latter, see Macromol. Chem. Phys. 2003, vol. Refer to 204 and 1738 for detailed explanation.

I-2. Characteristic (X-ii): Melt tension (MT)
The propylene homopolymer (X) preferably has a melt tension in the range of 3 to 25 g. A more preferable range of the melt tension and a method for measuring the melt tension are as described above.

I-3. Characteristic (X-iii): Melt flow rate (MFR)
The propylene homopolymer (X) preferably has an MFR in the range of 0.9 to 15 g / 10 min. A more preferable range of MFR and a method for measuring MFR are as described above.

I-4. Characteristic (X-iv): Ratio of components soluble in xylene at 25 ° C. (CXS)
The propylene homopolymer (X) preferably has a ratio of components soluble in xylene at 25 ° C. (CXS) of less than 5 wt% (here, the total amount of the propylene homopolymer is 100 wt%). CXS in the present invention is a value measured by the following procedure.

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

  CXS is a general index representing a low crystalline polymer component. If this value is high, the content of the low crystalline component in the propylene homopolymer (X) increases, which causes problems in molding and the product itself. May occur. For example, problems such as mess and smoke generation during extrusion foaming, and problems with stickiness of the surface of sheets, films, and products are likely to occur. The propylene homopolymer (X) preferably has a CXS of less than 5 wt%. CXS is more preferably less than 3 wt%, further preferably less than 1 wt%, and particularly preferably less than 0.5 wt%. Although there is no restriction | limiting in particular about the lower limit of CXS, The effect of an additive will become easy to express that it is 0.01 wt% or more, Preferably it is 0.05 wt% or more. Examples of a method for adjusting CXS to the above range include selection of a catalyst. What is necessary is just to select the catalyst for propylene homopolymer synthesis | combination which can satisfy | fill the requirements of the said CXS from a well-known catalyst. Specific examples of the catalyst will be described later.

I-5. Characteristic (Xv): Branch index g ′
The propylene homopolymer (X) preferably satisfies the above characteristics (Xi) to (X-iv), but the branching index g ′ at an absolute molecular weight Mabs of 1,000,000 is 0.3 or more. More preferably, it is less than 0.

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

  In general, if the polymer has the same molecular weight, the one having a branched structure is smaller, and therefore, from the above definition, when a long chain branched structure is present, the branching index g ′ takes a value smaller than 1. As the long chain branched structure increases, the value of the branching index g ′ decreases. In the foaming of polypropylene resin, the entanglement of molecular chains is important. Therefore, if a long chain branched structure exists in a component having a large molecular weight, the entanglement can be efficiently promoted and the foaming characteristics can be improved. Therefore, the propylene homopolymer preferably has a branching index g ′ within a specific range when the absolute molecular weight Mabs is 1 million. In order to know the value of the branching index g ′ when the absolute molecular weight Mabs is 1 million, the value of the branching index g ′ must be obtained as a function of the absolute molecular weight Mabs. In this regard, the following measurement method, analysis method, and calculation method can be used.

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

[analysis method]
When calculating the absolute molecular weight (Mabs) obtained from the multi-angle laser light scattering detector (MALLS), the root mean square radius of inertia (Rg), and the intrinsic viscosity ([η]) obtained from the Viscometer, data processing attached to MALLS Calculation is performed using the software ASTRA (version 4.73.04) with reference to the following document.
References:
1. “Developments in Polymer Characterization-4” (JV Dawkins ed. Applied Science Publishers, 1983. Chapter 1.)
2. Polymer, 45, 6495-6505 (2004).
3. Macromolecules, 33, 2424-2436 (2000)
4). Macromolecules, 33, 6945-6952 (2000)

[Calculation method of branching index g ′]
The branching index g ′ is a ratio of an intrinsic viscosity ([η] _br ) obtained by measuring a sample with the above Viscometer and an intrinsic viscosity ([η] _lin ) obtained by separately measuring a linear polymer ([[ η] _br / [η] _lin ).
Here, as a linear polymer for obtaining [η] _lin , a commercially available homopolypropylene (Novatec PP (registered trademark) grade name: FY6 manufactured by Nippon Polypro Co., Ltd.) is used. It is known as a Mark-Houwink-Sakurada formula that the logarithm of [η] _lin of a linear polymer has a linear relationship with the logarithm of molecular weight, and [η] _lin is The values are obtained by extrapolation as appropriate.

  The propylene homopolymer (X) preferably has a branching index g ′ of 0.3 or more and less than 1.0 when the absolute molecular weight Mabs is 1 million. More preferably, they are 0.55 or more and 0.98 or less, More preferably, they are 0.75 or more and 0.96 or less, Especially preferably, they are 0.78 or more and 0.95 or less. When the branching index g ′ is in the above range, the degree of decrease in melt tension when repeating kneading is further reduced, and therefore, the decrease in physical properties and moldability is preferably reduced during material recycling in the production process. As a method for adjusting the branching index g ′ within the above range, a catalyst can be selected. What is necessary is just to select what can synthesize | combine the propylene homopolymer which satisfy | fills the requirements of the branching index g 'among well-known catalysts. Specific examples of the catalyst will be described later.

I-6. Characteristic (X-vi): degree of strain hardening (λ _max ) in measurement of extensional viscosity
The propylene homopolymer preferably satisfies the above characteristics (X-i) to (X-iv). In addition, as a characteristic (X-vi), the strain hardening degree (λ _max ) in the measurement of the extensional viscosity is It is preferable that it is 5-15.

The degree of strain hardening (λ _max ) is also an important factor for foam molding. The strain hardening degree (λ _max ) of the propylene homopolymer is more preferably 6 to 14.5, and further preferably 7 to 14. If the value of strain hardening is in this range, the balance between spreadability and cell formation during foaming tends to be particularly good. Specific methods for controlling the degree of strain hardening within the above range include a method of changing the number of long chain branches by adjusting the catalyst production method (particularly the loading ratio of the complex) and the range of characteristics (X-iii). There is a method for adjusting the MFR. When the number of long chain branches is increased or the MFR is lowered, the strain hardening degree is increased. In order to lower the strain hardening degree, it is sufficient to adjust in the opposite direction.

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

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

I-7. Other properties (X-vii): mm fraction The preferred properties of the propylene homopolymer are as described above. In addition, as the properties (X-vii), the isoform determined by ¹³ C-NMR is used. The tactic triad fraction (mm fraction) is more preferably 95% or more.

Here, the mm fraction indicates the abundance of two consecutive methyl groups in which the steric relationship between adjacent methyl groups in the three chain of propylene units is meso, and the definition in the present invention, the measurement condition of ¹³ C-NMR, It shall be as described in JP 2009-275207 A.
The mm fraction is an index of stereoregularity. A higher value means that propylene units are regularly arranged in the polymer chain, and the degree of crystallinity tends to increase. Accordingly, the higher the mm fraction, the higher the heat resistance and rigidity, so that it is preferable. In the propylene homopolymer (X), the mm fraction is preferably 95% or more, more preferably 96% or more, and still more preferably 97% or more. As a specific method for adjusting the mm fraction to the above range, a catalyst can be selected. What is necessary is just to select what can synthesize | combine the propylene homopolymer which satisfy | fills the requirement of mm fraction among the well-known catalysts. Specific examples of the catalyst will be described later.

II. Propylene Homopolymer (X) Production Method The propylene homopolymer (X) in the present invention is not particularly limited as long as the above-mentioned properties (Xi) to (X-iv) are satisfied. However, as described above, a preferable production method for satisfying all the conditions such as high stereoregularity, low low crystalline component amount, relatively wide molecular weight distribution, range of branching index g ′, high melt tension, This is a method using a macromer copolymerization method using a combination of metallocene catalysts. As an example of such a method, for example, a method disclosed in Japanese Patent Application Laid-Open No. 2009-57542 can be given.
This method produces a polypropylene having a long-chain branched structure using a catalyst in which a catalyst component having a specific structure having macromer-producing ability and a catalyst component having a specific structure having high molecular weight and macromer copolymerization ability are combined. According to this, industrially effective methods such as bulk polymerization and gas phase polymerization, particularly single-stage polymerization under practical pressure-temperature conditions, and using hydrogen as a molecular weight regulator. It is possible to produce a polypropylene having a long-chain branched structure having the desired physical properties.
In the past, it was necessary to increase the branching efficiency by lowering the crystallinity by using a polypropylene component having a low stereoregularity. However, in the above method, a polypropylene component having a sufficiently high stereoregularity is required. , Which can be introduced into the side chain by a simple method, and is preferred as the propylene homopolymer (X) used in the present invention (X-iv) relating to high stereoregularity and low amount of low crystalline components It is suitable for satisfying the characteristic of (Xv).
Moreover, if the said method is used, molecular weight distribution can be widened by using two types of catalysts from which a superposition | polymerization characteristic differs greatly, and propylene homopolymer (X) which has a long-chain branched structure used for this invention Necessary characteristics (X-i) to (X-iii) can be satisfied at the same time, which is preferable.
Hereinafter, this method is selected as a specific example of the method for producing the propylene homopolymer (X) and will be described in detail.

II-1. Catalyst It is preferable to use a catalyst comprising the following catalyst components (A), (B) and (C).
Catalyst component (A): at least one from component [A-1] which is a compound represented by the following general formula (a1), and component [A-2] which is a compound represented by the following general formula (a2) A mixture of at least one selected from at least one catalyst component (B): an ion-exchange layered silicate catalyst component (C): an organoaluminum compound

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

[In General Formula (a1), each of R ¹¹ and R ¹² independently represents a heterocyclic group containing nitrogen, oxygen or sulfur having 4 to 16 carbon atoms. Each of R ¹³ and R ¹⁴ independently represents an aryl group having 6 to 16 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected from these, Alternatively, it represents a heterocyclic group containing nitrogen, oxygen or sulfur having 6 to 16 carbon atoms. X ¹¹ and Y ¹¹ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. , An oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, trifluoromethanesulfone It represents an acid group or a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms. Q ¹¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or a germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms. ]

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

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

In the general formula (a1), X ¹¹ and Y ¹¹ are auxiliary ligands and react with the catalyst component (B) to generate an active metallocene having olefin polymerization ability. Therefore, as long as this object is achieved, X ¹¹ and Y ¹¹ are not limited in the type of ligand within the range defined above.

In general formula (a1), Q ¹¹ is a binding group that bridges two conjugated five-membered rings, and is a divalent hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms. A silylene group or a germylene group which may be present is shown. When two hydrocarbon groups are present on the silylene group or the germylene group, they may be bonded to each other to form a ring structure.
Specific examples of Q ¹¹ include alkylene groups such as methylene, methylmethylene, dimethylmethylene and 1,2-ethylene; arylalkylene groups such as diphenylmethylene; silylene groups; methylsilylene, dimethylsilylene, diethylsilylene, di ( alkylsilylene groups such as n-propyl) silylene, di (i-propyl) silylene, di (cyclohexyl) silylene, (alkyl) (aryl) silylene groups such as methyl (phenyl) silylene; arylsilylene groups such as diphenylsilylene; tetra An alkyl oligosilylene group such as methyldisilylene; a germylene group; an alkylgermylene group in which the silicon of the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl) (aryl) germylene Group; aryl Examples thereof include a germylene group. In these, the silylene group which has a C1-C20 hydrocarbon group, or the germylene group which has a C1-C20 hydrocarbon group is preferable, and an alkylsilylene group and an alkylgermylene group are more preferable.

Of the compounds represented by the general formula (a1), preferred compounds are specifically exemplified below.
Dichloro [1,1′-dimethylsilylenebis {2- (2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-thienyl) -4-phenyl -Indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-diphenylsilylenebis {2 -(5-Methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylgermylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl} ] Hafnium, dichloro [1,1'-dimethylgermylenebis {2- (5-methyl-2-thienyl) -4-phenyl-indenyl}] hafnium, dic B [1,1′-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5- Trimethylsilyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-phenyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [ 1,1′-dimethylsilylenebis {2- (4,5-dimethyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-benzofuryl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) Nyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) -indenyl}] hafnium, dichloro [1 , 1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trimethylsilylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2- Furfuryl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-chlorophenyl) -indenyl}] hafnium, dichloro [ 1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-fluorophenyl) -indenyl}] hafnium, di Loro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trifluoromethylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis { 2- (5-Methyl-2-furyl) -4- (4-t-butylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-furyl) -4- ( 1-naphthyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1′-dimethyl Silylenebis {2- (2-furyl) -4- (2-phenanthryl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (2-furyl) -4- ( -Phenanthryl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1 '-Dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2 -Furyl) -4- (2-phenanthryl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (9-phenanthryl) -indenyl} ] Hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-tert-butyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, Chloro [1,1′-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2 -(5-t-butyl-2-furyl) -4- (2-phenanthryl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (9-phenanthryl) -indenyl}] hafnium, and the like.

Of these, more preferable 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}] hafniu , 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.
More preferably, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis { 2- (5-Methyl-2-furyl) -4- (4-i-propylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-Trimethylsilylphenyl) -indenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-t-butylphenyl) -indenyl }] Hafnium.

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

[In General Formula (a2), each of R ²¹ and R ²² independently represents a hydrocarbon group having 1 to 6 carbon atoms. R ²³ and R ²⁴ are each independently an 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. is there. X ²¹ and Y ²¹ each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon having 1 to 20 carbon atoms. Represents a group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, Q ²¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, or carbon It represents a silylene group or a germylene group that may have a hydrocarbon group of 1 to 20. M ²¹ is zirconium or hafnium. ]

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

R ²³ and R ²⁴ may each independently contain halogen having 6 to 16 carbon atoms, preferably 6 to 12 carbon atoms, silicon, or a plurality of hetero elements selected from these. An aryl group. Preferred examples include phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4- (2-fluoro-4-biphenylyl), 4- (2-chloro-4-biphenylyl), 1-naphthyl, 2-naphthyl, 4-chloro-2-naphthyl, 3-methyl-4-trimethylsilylphenyl, 3,5 -Dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl, 3,5-dichloro-4-trimethylsilylphenyl and the like.

X ²¹ and Y ²¹ are auxiliary ligands, and react with the catalyst component (B) to generate active metallocene having olefin polymerization ability. Therefore, as long as this object is achieved, the types of X ²¹ and Y ²¹ are not limited within the scope of the above definition.

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

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

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

Non-limiting examples of the metallocene compound represented by the general formula (a2) include the following.
However, only the representative exemplary compounds are described below avoiding many complicated examples, and the present invention is not construed to be limited to these compounds, and various ligands, crosslinking groups or auxiliary coordinations are described. It is obvious that children can be used arbitrarily.
Also, although compounds having a central metal of hafnium have been described, compounds substituted for zirconium can be used as well, and are treated as disclosed herein.

  Dichloro {1,1′-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazurenyl)} hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4 -Hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis { 2-methyl-4- (4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-chloro-4-t-butylphenyl)- 4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- ( -Methyl-4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl} ] Hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2 -Methyl-4- (1-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [ 1,1′-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl)- -Hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-Methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (9-phenanthryl) -4-hydroazurenyl] }] Hafnium, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-n-propyl -4- (3-Chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] huff Nitrogen, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-tert-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis { 2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylgermylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) ) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylgermylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′- (9-silafluorene-9,9-diyl) bis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] Funium, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-ethyl -4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium, dichloro [1,1 ′-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3 5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, and the like.

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

  More preferably, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2- Ethyl-4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4 -Hydroazulenyl}] hafnium, dichloro [1,1 ′-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl} ] Hafnium.

(2) Catalyst component (B)
The catalyst component (B) preferably used for producing the propylene homopolymer (X) is an ion-exchange layered silicate.
(I) Types of ion-exchanged layered silicates Ion-exchanged layered silicates (hereinafter sometimes simply referred to as silicates) are surfaces in which ionic bonds and the like are stacked in parallel with each other by a binding force. A silicate compound having a crystal structure and containing exchangeable ions. Most silicates are naturally produced mainly as a main component of clay minerals, and therefore often contain impurities (quartz, cristobalite, etc.) other than ion-exchangeable layered silicates. But you can. Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, it may be preferable to pure silicate, and such a complex is also included in the catalyst component (B). The ion-exchange layered silicate used in the present invention is not limited to a natural product, and may be an artificial synthetic product or may contain them.

Specific examples of the silicate include the following layered silicates described in Haruo Shiramizu “Clay Mineralogy” Asakura Shoten (1995).
That is, smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, vermiculite such as vermiculite, mica, mica, illite, sericite, sea green stone, attapulgite, sepiolite, palygorskite , Bentonite, pyrophyllite, talc, chlorite group.
The silicate is preferably a silicate in which the main component silicate has a 2: 1 type structure, more preferably a smectite group, and even more preferably montmorillonite. The type of interlayer cation is not particularly limited, but a silicate containing an alkali metal or an alkaline earth metal as a main component of the interlayer cation is preferable from the viewpoint of being relatively easy and inexpensive to obtain as an industrial raw material.

(Ii) Chemical treatment of ion-exchange layered silicate The ion-exchange layered silicate as the catalyst component (B) according to the present invention can be used as it is without any particular treatment, but the chemical treatment can be performed. preferable. Here, the chemical treatment of the ion-exchange layered silicate can use either a surface treatment that removes impurities adhering to the surface or a treatment that affects the structure of the clay. Specifically, Examples include acid treatment, alkali treatment, salt treatment, and organic matter treatment.

<Acid treatment>:
In addition to removing impurities on the silicate surface, the acid treatment can elute some or all of cations such as Al, Fe, and Mg having a crystalline 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 acid used for the treatment may be a combination of two or more.

<Salt treatment>:
It is also preferred that 40% or more, preferably 60% or more of the exchangeable metal cations contained in the silicate before being treated with salts are ion exchanged with cations dissociated from the salts shown below.
There are no particular restrictions on the type of salt used in such salt treatment for ion exchange. For example, selected from the group consisting of a cation containing at least one atom selected from the group consisting of Group 1 to 14 atoms of the periodic table, a halogen anion, an anion derived from an inorganic acid, and an anion derived from an organic acid. Preferred examples include compounds composed of at least one anion. Here, the anion derived from an acid is an anion in which at least one hydrogen cation is eliminated from the acid. For example, in the case of a monovalent inorganic acid such as HNO ₃ , the anion derived from the acid is NO ₃ ^— , and in the case of a trivalent inorganic acid such as H ₃ PO ₄ , the acid There are three types of anions derived from H ₂ PO ₄ ⁻ , HPO ₄ ²⁻ and PO ₄ ³⁻ . The same applies to anions derived from organic acids. More preferred are salts in which the cation is a metal ion and the anion is an anion derived from an inorganic acid or a halogen anion. Moreover, what combined 2 or more types of salts may be used.

Specific examples of such salts are LiF, LiCl, LiBr, LiI, Li ₂ SO ₄ , Li (CH ₃ COO), Li ₂ CO ₃ , LiHCO ₂ , Li ₂ C ₂ O ₄ , LiClO ₄ , Li _3. PO ₄ , CaCl ₂ , CaSO ₄ , CaC ₂ O ₄ , Ca (NO ₃ ) ₂ , MgCl ₂ , MgBr ₂ , MgSO ₄ , Mg ₃ (PO ₄ ) ₂ , Mg (ClO ₄ ) ₂ , MgC ₂ O ₄ , Examples thereof include salts of alkali metals or Group 2 elements such as Mg (NO ₃ ) ₂ and Mg (CH ₃ COO) ₂ .

_{Further, Ti (CH 3 COO) 4} , Ti (CO 3) 2, Ti (NO 3) 4, Ti (SO 4) 2, TiF 4, TiCl 4, Zr (CH 3 COO) 4, Zr (CO 3) ₂ , Zr (NO ₃ ) ₄ , Zr (SO ₄ ) ₂ , ZrF ₄ , ZrCl ₄ , Hf (CH ₃ COO) ₄ , Hf (CO ₃ ) ₂ , Hf (NO ₃ ) ₄ , Hf (SO ₄ ) _{2 , HfF 4, HfCl 4, V} (CH 3 COCHCOCH 3) 3, VOCl 3, VCl 3, VCl 4, VBr 3, 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 , 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 , Examples include transition metal salts such as Ni (ClO ₄ ) ₂ , NiSO ₄ , NiCl ₂ , and NiBr ₂ .

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.

  The treatment conditions with the acid or salts are not particularly limited, but usually the acid or salt concentration is 0.1 to 50% by weight, the treatment temperature is room temperature to the boiling point of the treatment solution, and the treatment time is 5 minutes to 24 hours. It is preferable to carry out the reaction under conditions that elute at least a part of the substance constituting the silicate. The acid and salt are generally used in an aqueous solution. Moreover, you may use what combined the said acids and salts as a processing agent.

<Alkali treatment>:
In addition to acid and salt treatment, alkali treatment or organic matter treatment may be performed as necessary. Examples of the treating agent used in the alkali treatment include LiOH, NaOH, KOH, Mg (OH) ₂ , Ca (OH) ₂ , Sr (OH) ₂ , Ba (OH) _{2 and the} like.

<Organic treatment>:
Examples of the organic treatment agent used for the organic treatment include trimethylammonium, triethylammonium, N, N-dimethylanilinium, triphenylphosphonium and the like. Examples of the anion constituting the organic treatment agent include hexafluorophosphate, tetrafluoroborate, tetraphenylborate and the like, in addition to the anions constituting the salts for salt treatment exemplified above. It is not limited to.

  Moreover, these processing agents may be used independently and may be used in combination of 2 or more types. These combinations may be used in combination for the treatment agent added at the start of the treatment, or may be used in combination for the treatment agent added during the treatment. The chemical treatment can be performed a plurality of times using the same or different treatment agents.

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

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

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

  The catalyst component (B) is preferably spherical particles having an average particle size of 5 μm or more. If the particle shape is spherical, a natural product or a commercially available product may be used as it is, or a particle whose particle shape and particle size are controlled by granulation, sizing, or sorting may be used. Examples of the granulation method used here include stirring granulation method and spray granulation method. Moreover, you may use organic substance, an inorganic solvent, inorganic salt, and various binders in the case of granulation. The spherical particles obtained as described above preferably have a compressive fracture strength of 0.2 MPa or more, more preferably 0.5 MPa or more, in order to suppress crushing and generation of fine powder in the polymerization step. In the case of such particle strength, the effect of improving the particle properties is effectively exhibited particularly when prepolymerization is performed.

(3) Catalyst component (C)
The catalyst component (C) is an organoaluminum compound. Organic aluminum compounds used as the catalyst component (C) has the general ^{_{formula: (AlR 31 q Z 3-}} q) a compound represented by _p is suitable. The compounds represented by this formula can be used alone, in combination of plural kinds or in combination. In this formula, R ³¹ represents a hydrocarbon group having 1 to 20 carbon atoms, and Z represents a halogen, hydrogen, an alkoxy group or an amino group. q represents an integer of 1 to 3, and p represents an integer of 1 to 2, respectively. R ³¹ is preferably an alkyl group, and Z is a chlorine atom when it is a halogen atom, a C 1-8 alkoxy group when it is an alkoxy group, and a C 1 atom when it is an amino group. Eight amino groups are preferred.

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

(4) Formation of catalyst / preliminary polymerization In the catalyst, each of the above catalyst components (A) to (C) is contacted in the (preliminary) polymerization tank simultaneously or continuously, or once or multiple times. Can be formed. The contact of each component is performed in an aliphatic hydrocarbon or aromatic hydrocarbon solvent, for example. The contact temperature is not particularly limited, but is preferably between −20 ° C. and 150 ° C. As the contact order, any desired combination can be used. However, the preferred ones for each component are as follows.
Before contacting the catalyst component (A) with the catalyst component (B), the catalyst component (A), the catalyst component (B), or both the catalyst component (A) and the catalyst component (B) C), or contacting the catalyst component (C) with the catalyst component (A) and the catalyst component (B), or contacting the catalyst component (A) and the catalyst component (B). Although it is possible to contact the catalyst component (C) after the contact, a method of contacting the catalyst component (C) before contacting the catalyst component (A) and the catalyst component (B) is preferable. Moreover, after contacting each component, it is possible to wash with an aliphatic hydrocarbon or an aromatic hydrocarbon solvent.

The usage-amount of catalyst component (A), (B) and (C) is arbitrary. For example, the usage-amount of the catalyst component (A) with respect to a catalyst component (B) becomes like this. Preferably it is 0.1 micromol-1,000 micromol with respect to 1 g of catalyst components (B), More preferably, it is the range of 0.5 micromol-500 micromol. The amount of the catalyst component (C) relative to the catalyst component (A) is a transition metal molar ratio, preferably 0.01 to 5 × 10 ⁶ , more preferably 0.1 to 1 × 10 ^4. .

The ratio of said component [A-1] (compound represented by general formula (a1)) and said component [A-2] (compound represented by general formula (a1)) used by this invention is a propylene type | system | group. Although it is arbitrary as long as the above properties of the polymer are satisfied, the molar ratio of the transition metal of [A-1] to the total amount of each component [A-1] and [A-2], preferably 0.30 or more 0.99 or less.
By changing this ratio, it is possible to adjust the balance between melt physical properties and catalyst activity. That is, from the component [A-1], a low molecular weight terminal vinyl macromer is produced, and from the component [A-2], a high molecular weight body obtained by copolymerizing a part of the macromer is produced. Therefore, by changing the ratio of the component [A-1], the average molecular weight, molecular weight distribution, bias of the molecular weight distribution toward the high molecular weight side, very high molecular weight component, branch (amount, length, Distribution) can be controlled, whereby the melt physical properties such as strain hardening degree, melt tension, and melt spreadability can be controlled.

In order to produce a higher strain hardening propylene homopolymer (X), the ratio of [A-1] and [A-2] needs to be 0.30 or more, preferably 0.40 or more. Yes, more preferably 0.5 or more. Further, the upper limit is 0.99 or less, and in order to efficiently obtain the propylene homopolymer (X) with high catalytic activity, it is preferably 0.95 or less, and more preferably 0.90 or less. It is.
In addition, by using component [A-1] within the above range, it is possible to adjust the balance between the average molecular weight and the catalytic activity with respect to the amount of hydrogen.

  The catalyst according to the present invention is subjected to a prepolymerization treatment consisting of a small amount of polymerization by bringing an olefin into contact therewith. By performing the prepolymerization treatment, gel formation can be prevented when the main polymerization is performed. The reason is considered to be that long-chain branches can be uniformly distributed among the polymer particles when the main polymerization is performed, and the melt physical properties can be improved thereby.

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

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

II-2. Polymerization Method Any polymerization method can be adopted as long as the olefin polymerization catalyst containing the catalyst components (A), (B) and (C) and the monomer come into efficient contact. Specifically, a slurry polymerization method using an inert solvent, a so-called bulk polymerization method using a propylene monomer itself as a solvent without substantially using an inert solvent, a solution polymerization method, or each monomer using substantially no liquid solvent. It is possible to employ a gas phase polymerization method or the like that keeps the gas in a gaseous state. Moreover, the method of performing continuous polymerization and batch type polymerization can also be applied. In addition to single-stage polymerization, it is possible to carry out multistage polymerization of two or more stages. In the case of the slurry polymerization method, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene, and toluene is used alone or as a mixture as a polymerization solvent.

The polymerization temperature is 0 ° C. or higher and 150 ° C. or lower. In particular, when a bulk polymerization method is used, 40 ° C. or higher is preferable, and 50 ° C. or higher is more preferable. The upper limit is preferably 80 ° C. or lower, more preferably 75 ° C. or lower.
Furthermore, when using a gas phase polymerization method, it is preferably 40 ° C. or higher, more preferably 50 ° C. or higher. The upper limit is preferably 100 ° C. or lower, more preferably 90 ° C. or lower.
The polymerization pressure is preferably 1.0 MPa or more and 5.0 MPa or less. In particular, when a bulk polymerization method is used, 1.5 MPa or more is preferable, and 2.0 MPa or more is more preferable. The upper limit is preferably 4.0 MPa or less, more preferably 3.5 MPa or less.
Furthermore, when using vapor phase polymerization, 1.5 MPa or more is preferable, and 1.7 MPa or more is more preferable. Further, the upper limit is preferably 2.5 MPa or less, more preferably 2.3 MPa or less.
Further, as a molecular weight regulator and for an activity improving effect, hydrogen is supplementarily used in a molar ratio of 1.0 × 10 ⁻⁶ or more and 1.0 × 10 ⁻² or less with respect to propylene. it can.

Also, by changing the amount of hydrogen used, in addition to the average molecular weight of the polymer to be produced, the molecular weight distribution, the deviation of the molecular weight distribution toward the high molecular weight side, very high molecular weight components, branching (amount, length, Distribution) can be controlled, whereby the melt physical properties characterizing polypropylene having a long-chain branched structure such as MFR, strain hardening degree, melt tension (MT), and melt spreadability can be controlled.
Therefore, hydrogen should be used at a molar ratio to propylene of 1.0 × 10 ⁻⁶ or more, preferably 1.0 × 10 ⁻⁵ or more, more preferably 1.0 × 10 ⁻⁴ or more. Is good. Regarding the upper limit, it 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 using an α-olefin comonomer having 2 to 20 carbon atoms excluding propylene, for example, ethylene and / or 1-butene as a comonomer may be performed depending on the application.
Therefore, in order to obtain a propylene homopolymer (X) used in the present invention having a good balance between catalytic activity and melt properties, ethylene and / or 1-butene is used at 15 mol% or less based on propylene. More preferably, it is 10.0 mol% or less, More preferably, it is 7.0 mol% or less.

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

III. Propylene block copolymer (Y)
The propylene-based block copolymer (Y) blended together with the propylene homopolymer (X) having a long-chain branched structure described above may contain a propylene (co) polymer (Y-1) that may contain 10% by weight or less of a comonomer. ) And a propylene-based block copolymer (Y) composed of a propylene-ethylene copolymer (Y-2). More preferably, it is produced by performing multistage polymerization by a conventionally known sequential polymerization method.
The term block copolymer used here is different from a so-called (real) block copolymer or graft copolymer in which components polymerized at each stage are bonded by chemical bonding. The components produced in each step of multi-stage polymerization are not chemically bonded, so in general, crystallinity is determined by utilizing the difference in crystallinity, molecular weight, or solubility in a solvent between the components. Each component produced in each step can be separated by a technique such as fractionation, molecular weight fractionation, or solubility fractionation.
In addition, in the propylene-based block copolymer (Y) obtained by a conventionally known sequential polymerization method, a long chain branched structure by a chemical bond such as the propylene homopolymer (X) is recognized to be present with analyzable accuracy. Absent.

The propylene block copolymer (Y) in the present invention has the following characteristics (Yi) to (Yv), and the propylene homopolymer (X) having the long-chain branched structure is shear-flowed. It is easy to suppress the formation of the structure formed below, which is preferable.
Characteristic (Yi): When the total amount of the propylene-based block copolymer (Y) is 100 wt%, the propylene (co) polymer (Y-1) which may contain a comonomer of 10 wt% or less is 50 to 99 wt%. And 1-50 wt% of propylene-ethylene copolymer (Y-2).
Characteristic (Y-ii): Melt flow rate (230 ° C., 2.16 kg) is in the range of 0.1 to 200 g / 10 min.
Characteristic (Y-iii): Melting point is 155 ° C. or higher.
Characteristic (Y-iv): The ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 38 wt%.
Characteristic (Yv): The intrinsic viscosity of propylene-ethylene copolymer (Y-2) in decahydronaphthalene at 135 ° C. is 5.3 dl / g or more.

III-1. Characteristic (Yi): Proportion of propylene (co) polymer and propylene-ethylene copolymer (Y-2) Propylene (co) polymer (Y-1) and propylene-ethylene copolymer (Y-2) ) Is preferably 50 to 99 wt%, more preferably 55 to 97 wt%, and still more preferably 60 to 95 wt%. Correspondingly, the proportion of (Y-2) is preferably 1 to 50 wt%, more preferably 3 to 45 wt%, and still more preferably 5 to 40 wt%.
However, regarding the weight ratio 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 a propylene homopolymer (X) having a long-chain branched structure, good spreading properties are imparted, and the molding processable temperature in various molding methods. There are advantages such as wide range, good appearance, and good mechanical properties such as impact characteristics. When the amount of the (Y-2) component is set to be equal to or higher than the lower limit of the above range, these advantages can be easily obtained. On the other hand, when the amount is set to be equal to or lower than the upper limit of the above range, it is a crystalline component (Y-1). Can be kept 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 production amount and propylene in the first step for producing the propylene (co) polymer (Y-1). -It can control by the manufacturing amount in the 2nd process which manufactures an ethylene copolymer (Y-2).
For example, in order to increase the amount of propylene (co) polymer (Y-1) and reduce the amount of propylene-ethylene copolymer (Y-2), the second step while maintaining the production amount of the first step For this purpose, the residence time in the second step may be shortened or the polymerization temperature may be lowered. In addition, when a polymerization inhibitor such as ethanol or oxygen is added, or when a polymerization inhibitor is originally added, the component (Y-1) and the component (Y-2) can also be increased or decreased. The weight ratio of can be controlled.

III-2. Characteristic (Y-ii): Melt flow rate (MFR)
The MFR of the propylene-based block copolymer (Y) used in the present invention is preferably in the range of 0.1 to 200 g / 10 min, more preferably in the range of 0.2 to 190 g / 10 min. More preferably, it is the range of 0.5-180 g / 10min, Most preferably, it is the range of 2.1-170 g / 10min.
This is a normal range as the MFR range of the resin used for various moldings. By setting the range 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. It is possible to reduce the neck-in at the time of extrusion molding and to facilitate sheet take-up by setting the upper limit or less. In addition, the measuring method of MFR is the same as the measuring method in the above-mentioned propylene homopolymer (X).
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) ( Y-2) holds the following relational expression.
log _e [MFR (Y)] = W (Y−1) × log _e [MFR (Y−1)] + W (Y−2) × log _e [MFR (Y−2)]
(Where log _e is the logarithm with e as the base. W (Y-1) and W (Y-2) are the propylene (co) weights in the propylene-based block copolymer (Y), respectively. (This is the weight fraction of the union (Y-1) and the propylene-ethylene copolymer (Y-2), and W (Y-1) + W (Y-2) = 1).)

This relational expression is an empirical expression called a logarithmic addition law of viscosity, and is used routinely in the industry. That is, the weight ratio of propylene (co) polymer (Y-1) to propylene-ethylene copolymer (Y-2), MFR (Y), MFR (Y-1), and MFR (Y-2) are independent. is not. Therefore, in order to control MFR (Y), it is only necessary to control the three factors of weight ratio of propylene-ethylene copolymer (Y-2), MFR (Y-1), and MFR (Y-2). 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), MFR (Y) can be increased even if W (Y-1) is increased and W (Y-2) is decreased. Will be easily understood. The same applies to the reverse control.
Which of these methods is more preferable is described below. MFR (Y-2) needs to be controlled to a certain low value based on the definition of the characteristic (Yv) described later, and when MFR (Y) is controlled. It is preferable to use a method of controlling the weight ratio of MFR (Y-1) and / or (Y-1) and (Y-2). Furthermore, since the weight ratio of (Y-1) and (Y-2) is defined by the above-mentioned characteristic (Yi), it is particularly preferable to use a method of controlling MFR (Y-1). .
As a method for controlling MFR (Y-1) and MFR (Y-2), a method using hydrogen as a chain transfer agent is the simplest. Specifically, when the concentration of hydrogen as 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, it is only necessary to increase the amount of hydrogen supplied to the polymerization tank, and adjustment is extremely easy for those skilled in the art. The same applies to the control of MFR (Y-2).

MFR (Y-1) is preferably 1 to 100 g / 10 min. If it is less than or equal to this upper limit, the propylene-ethylene copolymer (Y-2) is well dispersed and the appearance of the product is improved. More preferably, it is 70 g / 10 minutes or less, More preferably, it is 60 g / 10 minutes or less, Most preferably, it is 50 g / 10 minutes or less. On the other hand, if it is at least the lower limit value, the fluidity of the propylene-based block copolymer (Y) is improved, the spreadability of the polypropylene resin composition for foam molding is improved, and foam breakage at the time of foaming is prevented. This is preferable because the surface appearance becomes good and the appearance of the final product becomes good. More preferably, it is 5 g / 10 minutes or more, More preferably, it is 10 g / 10 minutes or more, Most preferably, it is 15 g / 10 minutes or more.
In addition, the measuring method of MFR is the same as the measuring method of MFR in propylene homopolymer (X).

III-3. Characteristic (Y-iii): Melting point The melting point of the propylene-based block copolymer (Y) used in the present invention is preferably higher than 155 ° C from the viewpoint of maintaining the heat resistance of the sheet, and is 157 ° C or higher. More preferred. The upper limit of the melting point is not particularly limited, but it is practically difficult to produce a melting point exceeding 170 ° C. Here, the melting point is determined by using differential scanning calorimetry (DSC), once the temperature is raised to 200 ° C. and the thermal history is erased, then the temperature is lowered to 40 ° C. at a temperature lowering rate of 10 ° C./min, and the temperature is raised again The temperature is the endothermic peak top temperature when measured at a rate of 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 good 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). When MFR (Y-1) is increased, the melting point of (Y-1) is decreased, and even when the comonomer content is increased, the melting point of (Y-1) is decreased. The relationship between the MFR (Y-1) or comonomer content and the melting point is examined in advance, and the MFR (Y-1) or comonomer content can be adjusted so as to obtain a desired melting point.

III-4. Characteristic (Y-iv): ethylene content in propylene-ethylene copolymer component (Y-2) In propylene-ethylene copolymer component (Y-2) in propylene-based block copolymer (Y) of the present invention The ethylene content is preferably 11 to 38 wt% (provided that the total amount of 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%, and 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 examined in advance, and the monomer supply ratio may be adjusted so that the gas composition in the polymerization tank has a value corresponding to the desired ethylene content.
When an ethylene content within the above range is used, the propylene homopolymer (X) having a long-chain branched structure has an effect of suppressing the formation of a structure formed under shear flow. The effect is reduced. About the reason, the present inventors are estimating as follows.
The propylene-based block copolymer (Y) according to the present invention functions to prevent the propylene homopolymer (X) having a long-chain branched structure from forming a unique structure under shear. Since the structure is a so-called shishi kebab structure (or its precursor), it is as low a crystallinity component as possible, and in order to suppress the growth of the structure, the mobility is as low as possible, that is, the molecular weight is high. Ingredients are considered preferred. However, if the ethylene content falls below this specified range, (Y-2) itself has crystallinity, and the formation of a shishi-kebab structure cannot be suppressed. On the other hand, when the ethylene content of (Y-2) is too high, the (Y-2) component forms a sea-island structure with the (Y-1) component and exists as a completely different phase. In addition, 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.

III-5. Characteristic (Yv): Intrinsic viscosity of propylene-ethylene copolymer component (Y-2) 135 of propylene-ethylene copolymer component (Y-2) in propylene-based block copolymer (Y) of the present invention The intrinsic viscosity value measured using decalin at 0 ° C. as a solvent is preferably 5.3 dl / g or more. More preferably, it is 6.0 dl / g or more, More preferably, it is 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 is preferably a component having a high molecular weight, and the molecular weight is correlated with the viscosity. Therefore, the intrinsic viscosity value should be set to be above the lower limit of this range. Thus, the effect of suppressing the formation of the shishi-kebab structure can be increased.
If the intrinsic viscosity value of the component (Y-2) is 5.3 dl / g or more, the upper limit value does not need to be specified, but if it is too high, it may cause gel formation, and preferably 15.0 dl. / G or less, more preferably 14.0 dl / g or less, further preferably 13.0 dl / g or less, and most preferably 12.0 dl / g or less.
Here, the intrinsic viscosity is a value measured using an Ubbelohde capillary viscometer using a temperature of 135 ° C., decalin as a solvent. In order to determine the intrinsic viscosity of the component (Y-2), the component (Y-2) is recovered as a component soluble in xylene at 25 ° C. by using the same method as described in the above CXS, and this intrinsic viscosity is recovered. Measurement shall be performed. However, when the ethylene content of the (Y-2) component is less than 15 wt%, it is difficult to sufficiently separate the (Y-2) component depending on the CXS method. In such a case, a small amount of the propylene (co) polymer (Y-1) component in the course of sequential polymerization is withdrawn, the intrinsic viscosity is measured, and further, the propylene-based block copolymer (Y) after completion of sequential polymerization. The total intrinsic viscosity is measured and determined by the following formula.
Intrinsic viscosity of component (Y-2) = [(Y) Intrinsic viscosity of entire component− {Intrinsic viscosity of component (Y−1) × weight fraction of component (Y−1) / 100}] / {(Y−2) ) Component 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 simplest method for controlling the intrinsic viscosity [η] as in MFR. Specifically, when the hydrogen concentration as the chain transfer agent is increased, the intrinsic viscosity [η] of the propylene-ethylene copolymer (Y-2) is decreased. The reverse is also true. In order to increase the concentration of hydrogen in the polymerization tank, it is only necessary to increase the amount of hydrogen supplied to the polymerization tank, and adjustment is extremely easy for those skilled in the art.

  Here, the ratio of (Y-1) and (Y-2) in the propylene-based block copolymer (Y) and the ethylene content in (Y-2C) are conventionally known IR, NMR, or solubility. It can be determined by an analysis method combining the fractionation method and the IR method. Various indexes of the propylene-based block copolymer (Y) were determined mainly by a method combining the cross fractionation method described below and the FT-IR method.

(1) Analytical device to be used (i) Cross fractionation device CFC T-100 (abbreviated as CFC) manufactured by Dia Instruments Co., Ltd.
(Ii) Fourier transform infrared absorption spectrum analysis FT-IR, Perkin Elmer 1760X
The fixed wavelength infrared spectrophotometer attached as the CFC detector is removed, and an FT-IR is connected instead, and this FT-IR is used as the detector. The transfer line from the outlet of the solution eluted from the CFC to the FT-IR is 1 m long, and the temperature is maintained at 140 ° C. throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1 mm and an optical path width of 5 mmφ, and the temperature is maintained at 140 ° C. throughout the measurement.
(Iii) Gel permeation chromatography (GPC)
The GPC column at 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-raising elution fractionation is 40, 100, and 140 ° C., and fractionation is performed in three fractions in total. In addition, the elution ratio (unit wt%) of the component eluting at 40 ° C. or lower (fraction 1), the component eluting at 40 to 100 ° C. (fraction 2), and the component eluting at 100 to 140 ° C. (fraction 3) is W _40, is defined as _{W 100, W 140.} W ₄₀ + W ₁₀₀ + W ₁₄₀ = 100. Moreover, each fractionated fraction is automatically transported to the FT-IR analyzer as it is.
(Vi) Solvent flow rate during elution: 1 mL / min

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

(4) Post-treatment and analysis of measurement results The elution amount and molecular weight distribution of the components eluted at each temperature are obtained using the absorbance at 2945 cm ⁻¹ obtained by FT-IR as a chromatogram. The elution amount is normalized so that the total elution amount of each elution component is 100%. Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene. The specific method is the same as described above.
Ethylene content distribution of each eluted component (the distribution of the molecular weight axis ethylene content along) uses the ratio of the absorbance of the absorbance and 2927cm ^-1 of 2956Cm ^-1 obtained by GPC-IR, polyethylene or polypropylene and ¹³ Using ethylene-propylene-rubber (EPR) whose ethylene content is known by C-NMR measurement and the like and a mixture thereof, it is converted into ethylene content (wt%) by a calibration curve prepared in advance. Ask.

(5) Content of propylene-ethylene copolymer The content of the propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) is defined by the following formula (I), and The procedure is required.
(Y-2) content _{(wt%) = W 40 ×} A 40 / B 40 + W 100 × A 100 / B 100 + W 140 × A 140 / B 140 (I)
W ₄₀ , W ₁₀₀ , and W ₁₄₀ are elution ratios (unit: wt%) in each of the above-described fractions, and A ₄₀ , A ₁₀₀ , and A ₁₄₀ are the respective fractions corresponding to W ₄₀ , W ₁₀₀ , and W _{140. a, B 40, B 100, B} 140 is included in each fraction ethylene content of (Y-2) component (unit: wt%): average ethylene content of the actual measurement in transfection (wt% basis) in is there.
A method for _obtaining A ₄₀ , A ₁₀₀ , A ₁₄₀ , B ₄₀ , B ₁₀₀ , and B ₁₄₀ will be described later.
The meaning of the formula (I) is as follows. The first term on the right side of the formula (I) is a term for calculating the amount of (Y-2) contained in fraction 1 (portion soluble at 40 ° C.). When fraction 1 contains only (Y-2) and does not contain PP, W ₄₀ contributes to the Y-2 content derived from fraction 1 as a whole, but fraction 1 contains (Y -2) In addition to the component derived from PP, a small amount of PP-derived component (extremely low molecular weight component and atactic polypropylene) is also included, so that part needs to be corrected. Therefore, by multiplying W ₄₀ by A ₄₀ / B ₄₀ , the amount derived from the component (Y-2) in fraction 1 is calculated. For example, when the average ethylene content (A ₄₀ ) of fraction 1 is 30% by weight and the ethylene content (B ₄₀ ) of (Y-2) contained in fraction 1 is 40% by weight, 30 of fraction 1 / 40 = 3/4 (that is, 75% by weight) is derived from (Y-2), and the remaining 1/4 is derived from PP. Thus, the operation of multiplying A ₄₀ / B ₄₀ by the first term on the right side means that the contribution of (Y−2) is calculated from the weight% (W ₄₀ ) of the fraction 1. The same applies to the second term on the right side, and for each fraction, the (Y-2) content is obtained by calculating and adding the contribution of (Y-2).

(I) As described above, the average ethylene contents corresponding to fractions 1 to 3 obtained by CFC measurement are A ₄₀ , A ₁₀₀ , and A ₁₄₀ , respectively (units are wt%). A method for obtaining the average ethylene content will be described later.
(Ii) The ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 is defined as B ₄₀ (unit is wt%). For fractions 2 and 3, it is considered that the rubber part is completely eluted at 40 ° C. and cannot be defined with the same definition, so in the present invention, it is defined as B ₁₀₀ = B ₁₄₀ = 100. B ₄₀ , B ₁₀₀ , and B ₁₄₀ are ethylene contents of (Y-2) contained in each fraction, but it is practically impossible to obtain this value analytically. The reason is that there is no means for completely separating and separating PP and (Y-2) mixed in the fraction. As a result of examination using various model samples, B ₄₀ can explain the improvement effect of material physical properties well by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. all right. Moreover, _B100 , _B140 has the crystallinity derived from an ethylene chain, and the quantity of (Y-2) contained in these fractions compared with the quantity of (Y-2) contained in the fraction 1. For two reasons, which are relatively few, it is closer to the actual situation when both are approximated to 100, and there is almost no error in calculation. Therefore, analysis is performed with B ₁₀₀ = B ₁₄₀ = 100.
(Iii) According to the following formula | equation, (Y-2) content is calculated | required.
(Y-2) content _{(wt%) = W 40 ×} A 40 / B 40 + W 100 × A 100/100 + W 140 × A 140/100 (II)
That is, W ₄₀ × A ₄₀ / B ₄₀ which is the first term on the right side of the formula (II) indicates the content (% by weight) having no crystallinity, and the second term and the third term. W ₁₀₀ × A _100/100 + W ₁₄₀ × A _140/100 which is the sum indicates (Y-2) content (wt%) having crystallinity.
_Here, the average ethylene content _A 40 of each fraction 1-3 obtained by _{B 40} and CFC _measurement, A _{100, A 140} is determined as follows.
Fraction 1 fractionated by the difference in crystal distribution is converted into a molecular weight distribution curve by a curve obtained by measuring the molecular weight distribution with a GPC column constituting a part of the CFC analyzer, and FT-IR connected to the back of the GPC column. A corresponding distribution curve of the ethylene content is determined. Ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B _40.
Also, captured as data points in the measurement, the sum of the product of the weight ratio and the ethylene content of each data point for each data point is an average ethylene content A _40.

The significance of setting the three types of fractionation temperatures is as follows.
In the CFC analysis of the present invention, 40 ° C. means a polymer having no crystallinity (for example, most of (Y-2), or a propylene polymer component (PP) having an extremely low molecular weight and an atactic component. It has the meaning that it is a temperature condition necessary and sufficient for fractionating only the component. Further, 100 ° C. means a component that is insoluble at 40 ° C. but becomes soluble at 100 ° C. (for example, (Y-2), a component having crystallinity due to a chain of ethylene and / or propylene, and The temperature is necessary and sufficient to elute only PP having low crystallinity. Furthermore, 140 ° C. is a component that is insoluble at 100 ° C. but becomes soluble at 140 ° C. (for example, a component having particularly high crystallinity in PP, and an extremely high molecular weight in (Y-2) and an ethylene crystal) The temperature is necessary and sufficient to elute only the component having the property and recover the entire amount of the propylene-based block copolymer (Y) used for the analysis. Note that the EP component contained in W ₁₄₀ is extremely small and can be substantially ignored.
(Y-2) an ethylene content in _{(wt%) = (W 40} × A 40 + W 100 × A 100 + W 140 × A 140) / [Y-2] (III)
However, [Y-2] is (Y-2) content (wt%) calculated | required previously.
Of (Y-2), ethylene content of the portion having no crystalline (E) (wt%), since the dissolution of the rubber part is completed at most 40 ° C. or less, approximated with the value of B _40.

However, in the analysis method based on the combination of the above-described cross fractionation method and FT-IR, the ethylene content of (Y-2) is less than 15 wt%, and there is no significant difference in crystallinity from (Y-1), and the fractionation by temperature In the case where it is not possible to perform sufficiently, accurate analysis becomes difficult. In such a case, the component (Y-1) is withdrawn during the successive polymerization, the molecular weight (when comonomer is copolymerized, the comonomer content is also measured), and further calculated by material balance. , (Y-1) and (Y-2) by determining the quantity ratio, and by measuring the comonomer content of the entire component (Y) at the end of sequential polymerization, the following simple addition rule of weight: It is preferable to determine the comonomer content of the component (Y-2). When ethylene is used as a comonomer, the ethylene content of (Y-2) is determined by the following formula.
(Y-2) component ethylene content = [(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 obtaining the amount ratio of the component (Y-1) and the component (Y-2), when producing products having different average molecular weights of the component (Y-1) and the component (Y-2) (Y) After the completion of sequential polymerization, GPC measurement of the whole is performed, and the obtained multimodal molecular weight distribution curve is peak-separated using commercially available data analysis software, and the weight ratio is calculated. It is also possible.

IV. Production Method of Propylene Block Copolymer (Y) The production method of the propylene block copolymer (Y) is not particularly limited as long as it satisfies the above characteristics (Yi) to (Yv).
Hereinafter, the manufacturing method of a propylene-type block copolymer (Y) is demonstrated in detail, giving a specific example.

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

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

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

(ZN-1b): Magnesium Any magnesium compound can be used as the magnesium source. Typical examples include compounds disclosed in JP-A No. 00-234707. In general, magnesium chloride, diethoxymagnesium, metallic magnesium, and butylmagnesium chloride are often used.

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

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

(2) Organoaluminum compound (ZN-2)
As the organoaluminum compound (ZN-2), compounds disclosed in JP-A No. 2004-124090 can be used. Among these, it is preferable to use a compound represented by the following general formula (2).
R ⁹ _c AlX _d (OR ¹⁰ ) _e (2)
(In the general formula (2), 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 of the compound represented by the general formula (2) include trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum chloride, diethylaluminum ethoxide, methylalumoxane and the like. Can do.

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

(ZN-3a): Organosilicon compound having an alkoxy group As the organosilicon compound (ZN-3a) having an alkoxy group which is a constituent of a Ziegler-Natta catalyst suitable for the production of a propylene-based block copolymer (Y) The compounds disclosed in JP-A-2004-124090 can be used. Among these, it is preferable to use a compound represented by the following general formula (3).
R ³ R ⁴ _a Si (OR ⁵ ) _b (3)
(In General Formula (3), R ³ represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. R ⁴ is selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group, and a heteroatom-containing hydrocarbon group. R ⁵ represents a hydrocarbon group, 0 ≦ a ≦ 2, 1 ≦ b ≦ 3, a + b = 3.
Specific examples of the compound represented by the general formula (3) include t-Bu (Me) Si (OMe) ₂ , t-Bu (Me) Si (OEt) ₂ , t-Bu (Et) Si (OMe). _{2, t-Bu (n-} Pr) Si (OMe) 2, c-Hex (Me) Si (OMe) 2, c-Hex (Et) Si (OMe) 2, c-Pen 2 Si (OMe) 2, i-Pr ₂ Si (OMe) ₂ , i-Bu ₂ Si (OMe) ₂ , i-Pr (i-Bu) Si (OMe) ₂ , n-Pr (Me) Si (OMe) ₂ , t-BuSi ( OEt) ₃ , (Et ₂ N) ₂ Si (OMe) ₂ , Et ₂ N—Si (OEt) _{3 and the} like.

(ZN-3b): Compound having at least two ether bonds As the compound having at least two ether bonds (ZN-3b), compounds disclosed in JP-A-3-294302 and JP-A-8-333413 Etc. can be used. Among these, it is preferable to use a compound represented by the following general formula (4).
_{^{R 8 O-C (R 7}} ) 2 -C (R 6) 2 -C (R 7) 2 -OR 8 ... (4)
(In the general formula (4), R ⁶ and R ⁷ are the .R ⁸ represent any free radicals each independently hydrogen atom, selected from the group consisting of hydrocarbon radicals and hetero atom-containing hydrocarbon group, Represents a hydrocarbon group or a heteroatom-containing hydrocarbon group.)
Specific examples of the compound represented by the general formula (4) include 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl- 1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 9,9-bis (methoxymethyl) fluorene, etc. Can do.

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

IV-2. Polymerization method (1) Sequential polymerization Next, the manufacturing method of the propylene-type block copolymer (Y) of this invention is explained in full detail.
The propylene-based block copolymer (Y) of the present invention is preferably a reactor blend comprising a propylene (co) polymer (Y-1) and a propylene-ethylene copolymer (Y-2). At that time, it is necessary to produce two polymer components, a propylene polymer (Y-1) and a propylene-ethylene copolymer (Y-2). A propylene-based block copolymer (Y) in which a propylene-ethylene copolymer (Y-2) having a relatively high molecular weight and low viscosity and MFR is uniformly dispersed in a propylene (co) polymer (Y-1). From the viewpoint of expressing the original performance, it is preferable to produce both the components by sequential polymerization.

Specifically, it is preferable to polymerize the propylene-ethylene copolymer (Y-2) in the second step after polymerizing the propylene (co) polymer (Y-1) in the first step. Although it is possible to reverse the order of production, the propylene-ethylene copolymer (Y-2) is a polymer having a low crystallinity with an ethylene content of 11 to 38 wt% from the definition of (Y-iv). For this reason, if it is produced in the first step, it may cause production troubles such as adhesion inside the polymerization tank or clogging of the transfer pipe, which is not preferable. When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally preferable to use a 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 changed using a single polymerization reactor by changing the polymerization conditions with time. It is possible to polymerize individually. As long as the effects of the present invention are not impaired, a plurality of polymerization reactors may be connected in parallel.
In the case of a continuous process, since it is necessary to polymerize propylene (co) polymer (Y-1) and propylene-ethylene copolymer (Y-2) separately, two or more polymerization reactors are connected in series. It is necessary to use equipment. For the polymerization reactor corresponding to the first step for producing the propylene (co) polymer (Y-1) and the polymerization reactor corresponding to the second step for producing the propylene-ethylene copolymer (Y-2), Although it must be in a serial relationship, a plurality of polymerization reactors may be connected in series and / or in parallel for each of the first step and the second step.

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

(3) General polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a 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 process to be selected, but can be used without any problem as long as it is in a pressure range usually used. Specifically, the polymerization can be performed in the range of 0 to 200 MPa, preferably in the range of 0.1 to 50 MPa. At this time, an inert gas such as nitrogen may coexist. Moreover, in the process for 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 polymerization amount can be easily controlled, but also the properties of the polymer particles can be improved.

The propylene (co) polymer (Y-1) produced in the preceding stage of the sequential polymerization is a propylene homopolymer or a propylene random copolymer obtained by copolymerizing a small amount of a comonomer without departing from the gist of the present invention. It is. As the comonomer, an α-olefin having up to about 10 carbon atoms excluding 3 such as ethylene, butene and hexene is usually used.
Although there is no restriction | limiting in particular in the content of the said comonomer, It is preferable that it is 10 wt% or less, More preferably, it is 3 wt% or less, Most preferably, it is 1 wt% or less. The comonomer content is usually controlled 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 examined in advance, and the monomer feed ratio may be adjusted so that the gas composition in the polymerization tank has a value corresponding to the desired comonomer content.

V. Polypropylene resin composition The polypropylene resin composition for foam molding of the present invention is preferably a resin composition containing the propylene homopolymer (X) and optionally the propylene-based block copolymer (Y). Furthermore, the polypropylene resin composition preferably satisfies the following characteristics (Zi) to (Z-iii).
Characteristic (Zi): 10 to 99 wt% of propylene homopolymer (X) and 1 to 90 wt% of propylene-based block copolymer (Y) are contained.
Characteristic (Z-ii): Melt tension measured at 230 ° C. is 1 g or more.
Characteristic (Z-iii): MFR is 0.1 to 20 g / 10 min.

V-1. Characteristic (Zi) Content of propylene homopolymer (X) and propylene-based block copolymer (Y) The polypropylene resin composition for foam molding is composed of 10 to 99 wt% of the propylene homopolymer (X) and propylene-based It is preferable to contain 1-90 wt% of block copolymers (Y).
The content of the propylene homopolymer (X) in the polypropylene resin composition is preferably 10 to 99 wt%, more preferably 10 to 90 wt%, and still more preferably 15 to 80 wt%. Correspondingly, the content of the propylene-based block copolymer (Y) in the polypropylene resin composition is preferably 1 to 90 wt%, more preferably 10 to 90 wt%, and still more preferably 20 to 85 wt% ( Here, the total of the propylene homopolymer (X) and the propylene-based block copolymer (Y) is 100 wt%).
By setting the content of the propylene homopolymer (X) to be equal to or higher than the lower limit of the above range, an increase in the open cell ratio of the foamed molded product can be suppressed, and drawdown can be reduced during thermoforming. By setting the content of the propylene homopolymer (X) below the upper limit of the above range, it is possible to maintain high ductility, improve the appearance of the sheet or film, increase the amount of extrusion, and improve productivity. . The content of the propylene homopolymer (X) and the propylene-based block copolymer (Y) can be adjusted to a desired range by adjusting the blend amount ratio when the resin composition is made.

V-2. Characteristic (Z-ii): Melt tension (MT)
The polypropylene resin composition has a melt tension of 1 g or more measured at 230 ° C. The lower limit is preferably 1.5 g or more, more preferably 2 g or more, further preferably 3 g or more, and the upper limit is preferably 20 g or less, more preferably 15 g or less, and even more preferably 10 g or less. Here, the melt tension of the polypropylene resin composition is a value obtained using the same measurement method as the melt tension of the characteristic (X-ii) of the propylene homopolymer (X). By setting the melt tension to be equal to or higher than the above lower limit value, the formation and growth of the cells at the time of foaming can be maintained well, the increase in the open cell ratio can be suppressed, and the cell size can be made uniform. Moreover, by setting the melt tension to be equal to or lower than the upper limit of the above value, the spreadability can be improved, the appearance of the sheet or film can be improved, the amount of extrusion can be increased, and the productivity can be improved.
There are several ways to adjust the melt tension to the above values. For example, the melt tension of the propylene homopolymer (X) may be changed, or can be adjusted by changing the blending amount of the propylene homopolymer (X) and the propylene block copolymer (Y). . Generally, when the content of the propylene homopolymer (X) is increased, the melt tension of the resin composition can be increased.

V-3. Characteristic (Z-iii): MFR
The polypropylene resin composition of the present invention preferably has an MFR of 0.1 to 20 g / 10 min. More preferably, it is the range of 1-15 g / 10min, More preferably, it is the range of 2-10g / 10min, Most preferably, it is the range of 3-8g / 10min. By setting the MFR within this range, the spreadability can be improved, the appearance of the sheet or film can be improved, the amount of extrusion can be increased, and the productivity can be improved. By setting the MFR to be equal to or lower than the upper limit of the above range, it is possible to suppress an increase in the open cell ratio of the foamed molded product, to keep the size of the bubbles uniform, and to suppress drawdown during thermoforming.
There are several ways to adjust the MFR to the above range. For example, the MFR of the polypropylene resin composition can be adjusted by adjusting the MFR of the propylene homopolymer (X) or the propylene-based block copolymer (Y). Moreover, when MFR of a propylene homopolymer (X) and a propylene-type block copolymer (Y) differs, MFR of a polypropylene resin composition can be adjusted also by changing both compounding quantity. For example, when the MFR of the propylene homopolymer (X) is higher than the MFR of the propylene block copolymer (Y), the MFR of the polypropylene resin composition is high when the blending amount of the propylene homopolymer (X) is increased. Become.

V-4. Diluent: Propylene (co) polymer (H)
In particular, in fields where high melt tension is required, such as foam molding, it is required to use a resin composition with high melt tension diluted with another resin from the viewpoint of achieving both physical properties and economic efficiency of the product. It is often done.
In the polypropylene resin composition of the present invention, the propylene homopolymer (X) that is a constituent component and the propylene-based block copolymer (Y) that is optionally contained are responsible for improving the foaming performance of each, Dilution with a resin that inhibits these can inhibit the effects of the present invention.
Therefore, it is preferable to use other resins for dilution as long as the effects of the present invention are not significantly impaired. In the polypropylene resin composition of the present invention, the propylene homopolymer (X) and the propylene-based block copolymer (Y) interact organically and exhibit a high effect on foaming performance. Even if it is diluted with the above resin or is extruded multiple times, a high effect is easily maintained.

In the present invention, a preferable resin used for dilution for improving economic efficiency while maintaining foaming performance is at least selected from the group consisting of a propylene homopolymer or ethylene and an α-olefin having 4 to 10 carbon atoms. When the propylene (co) polymer (H) is a copolymer of one kind of olefin and propylene and the propylene (co) polymer (H) is a copolymer, ethylene and α- in the propylene (co) polymer (H) A propylene (co) polymer (H) having an olefin content of 0 to 3 wt% is preferred.
This is a dilution of the propylene (co) polymer (H) having the same performance as the propylene (co) polymer (Y-1) contained in the propylene-based block copolymer (Y), which is a constituent of the present invention. If used as a material, the content of propylene homopolymer (X) in the diluted resin composition and the content of propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) is as follows. This is based on the fact that the foaming characteristics are not deteriorated when it can be maintained within the range of the resin composition of the invention.
On the other hand, when other propylene-based block copolymers or polyethylene resins that do not satisfy the requirements of the propylene-based block copolymer (Y) according to the present invention are used as a diluent, they are propylene-based block copolymers ( Since the improvement effect of the propylene-ethylene copolymer (Y-2) in Y) may be hindered and the effects of the present invention may be significantly hindered, care must be taken in the selection of the diluent.
Whether or not the effect of the present invention is remarkably hindered is, for example, whether or not the open cell ratio shows a value about three times that when the diluent is used and when the diluent is not used. Can be.

  The blending amount of the propylene (co) polymer (H) is preferably 0.1 to 1000 parts by weight, more preferably 1 to 500 parts by weight, and still more preferably 10 to 300 parts by weight with respect to 100 parts by weight of the polypropylene resin composition. Part. The content of the propylene homopolymer (X) in the diluted resin composition and the propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) is within the specified range of the polypropylene resin composition. The ratio of (Y-2) in the polypropylene resin composition is preferably 0.01 to 47.5 wt%, more preferably 1 with respect to the total amount of X, Y and H in the polypropylene resin composition. It is preferable to determine the blending amount of the propylene (co) polymer (H) so as to be ˜36 wt%, more preferably 4 to 25.5 wt%.

V-5. Additives In addition to the propylene (co) polymer (H) described above, various additives can be blended as optional components in the polypropylene resin composition of the present invention. Specifically, antioxidants, UV absorbers, light stabilizers, metal deactivators, stabilizers, neutralizers, lubricants, antistatic agents, antifogging, which are conventionally used as polyolefin resin compounding agents. Various additives such as an agent, a nucleating agent, a peroxide, a filler, an antibacterial and antifungal agent, and a fluorescent brightening agent can be added within a range not impairing the effects of the present invention. The compounding amount of these additives is 0.0001 to 3 wt%, preferably 0.001 to 1 wt%, in 100 wt% of the polypropylene resin composition.

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

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

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

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

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

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

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

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

The stabilizer is an additive for polyvinyl chloride (PVC) in the first place, and is used for the purpose of preventing degradation of hydrochloric acid (HCl) from PVC. Some of the various stabilizers also have a function as a neutralizing agent, and thus may be used as an additive for polyolefins.
A neutralizing agent is a compound used to neutralize chlorine components derived from Ziegler catalysts used in the production of polyolefins. As the neutralizing agent, a carboxylate having a neutralizing ability is often used, but an inorganic compound having a chlorine ion capturing ability can also be used. Stabilizers are essentially unnecessary additives when using metallocene catalysts that do not contain chlorine atoms, but chlorine atoms are chemical species that easily cause contamination, so from the viewpoint of stable production. Often used for insurance purposes.
Hereinafter, typical compounds are exemplified as the neutralizing agent.
Examples of the carboxylate type compound include calcium stearate and zinc stearate. Examples of the neutralizing agent for inorganic compounds include hydrotalcite and inclusions of aluminum hydroxide and lithium carbonate (trade name: Mizukarak).

V-6. Production Method of Polypropylene Resin Composition Known methods can be used for preparing the polypropylene resin composition for foam molding of the present invention. For example, a resin composition can be prepared by mixing a predetermined amount of each of propylene homopolymer (X), propylene-based block copolymer (Y), and optional additives with a dry blend, a Henschel mixer, or the like. it can. These may be melt kneaded by a single screw extruder, a twin screw kneader, a kneader or the like. At this time, in order to use for extrusion molding, it is preferable that the resin composition is melt-kneaded and pelletized. As a method of pelletizing the resin composition,
a. A mixture of a propylene homopolymer (X), a propylene-based block copolymer (Y), and an optional additive is melt-kneaded and pelletized.
b. A mixture of propylene homopolymer (X) and optional additives is melt-kneaded and pelletized, and propylene homopolymer (X) pellets are further mixed with propylene-based block copolymer (Y) and optional additives Then, it is melt-kneaded and pelletized.
b '. A mixture of the propylene-based block copolymer (Y) and an optional additive is melt-kneaded and pelletized, and further mixed with the propylene homopolymer (X) and an optional additive, followed by melt-kneading.
c. A mixture of a propylene homopolymer (X) and an optional additive and a mixture of a propylene block copolymer (Y) and an optional additive are melt-kneaded to obtain each pellet. Mix each pellet produced.
d. A mixture of a propylene homopolymer (X) and an optional additive and a mixture of a propylene block copolymer (Y) and an optional additive are melt-kneaded to obtain each pellet. The pellets thus obtained are mixed and further melt-kneaded to form pellets.
Such a method can be used.
Here, as a method for pelletizing the resin composition, “a mixture of the propylene homopolymer (X) and an arbitrary additive is melt-kneaded and pelletized” described in the above b, c and d. By this, the polypropylene resin for foam molding of the present invention can be prepared. Here, the propylene-based block copolymer (Y) is preferably produced by a sequential polymerization method, the propylene-based block copolymer (Y) is produced by sequential polymerization, and a propylene homopolymer A method for producing a polypropylene resin composition for foam molding, which comprises mixing (X) and the propylene-based block copolymer (Y) is also an embodiment of the present invention.

  Here, the polypropylene resin composition preferably satisfies the above characteristics (Zi) to (Z-iii), but the MT defined by the characteristics (Z-iii) and the MFR defined by the characteristics (Z-iii). These are values measured using both melt-kneaded propylene homopolymer (X) and propylene-based block copolymer (Y). Therefore, when these are simply mixed and used, or as in c, the propylene homopolymer (X) and the propylene block copolymer (Y) are mixed (dry blended), and both are extruded without being melt-kneaded. When used as a foaming resin composition, propylene homopolymer (X), propylene-based block copolymer (Y), and optional components are separately melt-kneaded using the same formulation, and the resulting pellets are used. The measurement of MT and MFR is performed, and the value thus obtained is determined as the value of MT and MFR of the polypropylene resin composition for extrusion foaming. In this case, melt kneading is performed using the method described in the examples described later.

  Hereinafter, materials, molded articles, molded articles and the like using the polypropylene resin composition of the present invention will be described in detail.

VI. Polypropylene resin foam molding material When performing foam molding using the polypropylene resin for foam molding and the polypropylene resin composition for foam molding of the present invention, a foaming agent is contained to obtain a polypropylene resin foam molding material.
<Foaming agent>
There is no restriction | limiting in particular in the kind of foaming agent used in order to obtain the polypropylene resin foam molding material of this invention, The well-known foaming agent currently used for a plastic, rubber | gum, etc. can be used. There is no restriction | limiting in particular also in the kind of foaming agent, You may use any kind, such as a microcapsule containing a physical foaming agent, a degradable foaming agent (chemical foaming agent), and a thermal expansion agent.

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

When a physical foaming agent is used, a bubble regulator can be used as necessary. Examples of the air conditioner include inorganic decomposable foaming agents such as ammonium carbonate, sodium bicarbonate, ammonium bicarbonate and ammonium nitrite, azo compounds such as azodicarbonamide, azobisisobutyronitrile and diazoaminobenzene, N, N′— Nitroso compounds such as dinitrosopentanemethylenetetramine and N, N′-dimethyl-N, N′-dinitrosoterephthalamide, benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p, p′-oxybisbenzenesulfonyl semicarbazide, p- Degradable foaming agents such as toluenesulfonyl semicarbazide, trihydrazinotriazine, barium azodicarboxylate, inorganic powders such as talc and silica, acidic salts such as polyvalent carboxylic acids, reaction of polyvalent carboxylic acids with sodium carbonate or sodium bicarbonate Mixed The like may be exemplified ones. These bubble regulators may be used alone or in combination.
When using the bubble regulator, the blending amount of the bubble regulator is 0.01% pure with respect to a total of 100 parts by weight of the propylene homopolymer (X) and the propylene-based block copolymer (Y). It is preferable to set it as the range of -5 weight part.

Specific examples of degradable foaming agents (chemical foaming agents) include a mixture of sodium bicarbonate and an organic acid such as citric acid, an azo foaming agent such as azodicarbonamide and barium azodicarboxylate, and N, N′-dinitrosopentamethylene. Nitroso blowing agents such as tetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, sulfohydrazide blowing agents such as p, p′-oxybisbenzenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, tri And hydrazinotriazine.
The blending amount of the blowing agent is preferably in the range of 0.05 to 6.0 parts by weight with respect to a total of 100 parts by weight of the propylene homopolymer (X) and optionally the propylene-based block copolymer (Y). More preferably 0.05 to 3.0 parts by weight, still more preferably 0.5 to 2.5 parts by weight, and particularly preferably 1.0 to 2.0 parts by weight.

VII. Polypropylene resin foam molding VII-1. Polypropylene resin extrusion foam molding The polypropylene resin foam molding material of the present invention can be used for extrusion molding, injection molding, thermoforming, calender molding, press molding, etc. Since the spreadability is good due to the tension, it is particularly suitable for various types of extrusion foaming. What type of extrusion foaming is used is not particularly limited.
Typical extrusion foam molding includes foam molding by foam sheet molding, foam film molding, foam blow molding and the like.
In the case of foam sheet molding, a known combination of an extruder and a die can be used. Use of the polypropylene resin for foam molding or the polypropylene resin composition for foam molding of the present invention for production of a foamed sheet is also an embodiment of the present invention.
The extruder may be uniaxial or biaxial. The die may be a T die or a circular shape (circular). The same applies to foam film formation. In the case of foam film formation, stretching may be further performed. As the stretching method, a known method can be used without limitation. For example, a tubular method, a tenter type stretching method, a roll stretching method, a pantograph type batch stretching method and the like can be exemplified. Also in the case of foam blow molding, a known method may be used. Specific examples include a direct blow molding machine or an accumulative blow molding machine.

VII-2. Polypropylene resin laminated foamed molded product When producing a polypropylene resin foamed laminated product, a laminated foamed molded product can also be used. Specifically, a foamed layer using the polypropylene resin composition or molding material of the present invention and a non-foamed layer made of a thermoplastic resin composition may be coextruded. For example, a polypropylene resin laminated foam molded body is obtained by co-extrusion of a layer made of a polypropylene resin foam molded body and a non-foamed layer made of a thermoplastic resin composition. At this time, a known co-extrusion method using a feed block or a multi-die using a plurality of extruders can be used.
The non-foamed layer used in the polypropylene resin laminate foamed molded article using the polypropylene resin composition for the foamed layer may be provided on any surface of the foamed layer, and the foamed layer is present between the non-foamed layers. It is also possible to adopt a configuration (sandwich structure).

  When the polypropylene resin laminated foam-molded body is a sheet, the thickness of the sheet is not particularly limited, but is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm-5 mm. Moreover, the thickness of the non-foamed layer in the polypropylene resin laminated foam sheet is 1 to 50% of the total thickness of the obtained polypropylene resin laminated foam molded product, more preferably 5 to prevent the growth of bubbles in the foamed layer. It is preferable to form so as to be 20%.

  Polypropylene resin laminate foam molded body provided with a non-foamed layer is excellent in strength, and is excellent in surface smoothness and appearance by providing a non-foamed layer at least outside the foamed layer. It becomes. In addition, by using a functional thermoplastic resin for the non-foamed layer, additional functions such as antibacterial properties, soft feeling, and scratch resistance can be easily combined with the polypropylene resin laminated foam molded article. ,preferable.

As the thermoplastic resin constituting the thermoplastic resin composition used for the non-foamed layer, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and propylene-α can be used as long as the effects of the present invention are not impaired. -Olefin copolymers, polyolefins such as poly-4-methyl-pentene-1, olefinic elastomers such as ethylene-propylene elastomer, or other monomers copolymerizable therewith, for example vinyl acetate, vinyl chloride, (meta ) Copolymers and mixtures such as acrylic acid and (meth) acrylic acid esters can be selected.
Among these, polypropylene and propylene-α-olefin copolymers are preferable from the viewpoint of securing adhesiveness, heat resistance, oil resistance, rigidity and the like while further improving recyclability. The propylene-α-olefin copolymer includes a propylene-based block copolymer obtained by multi-stage polymerization of a propylene polymer and an ethylene-propylene random copolymer using a plurality or a single polymerization tank. .
Among these, the propylene-based block copolymer is more preferable because of its excellent balance between rigidity and impact resistance, and the propylene-based block copolymer (provided that the propylene-based block copolymer (Y) satisfies the requirements) When the polypropylene resin composition containing Y) 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 is thermoformed. This is preferable because it has a feature of high cell retention. Under the present circumstances, it is preferable that the content rate of the propylene-type block copolymer in the polypropylene resin composition used for a non-foaming surface layer is 0.1-100 wt%.

  In particular, when used as a thermoformed article, the rigidity of the formed article is very important. In order to improve the rigidity, it is preferable to provide a non-foamed layer on the surface layer and blend an inorganic filler in the non-foamed layer. In the thermoplastic resin composition used for the non-foamed layer, it is preferable to blend 50 parts by weight or less of an inorganic filler with respect to 100 parts by weight of the thermoplastic resin. When the amount is 50 parts by weight or less, the occurrence of scraping at the die outlet is prevented, and the appearance of the sheet tends to be good. Examples of the inorganic filler include talc, calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate and the like.

VII-3. Polypropylene resin foam-molded sheet In the present invention, the shape and molding method of the polypropylene resin foam-molded product are not limited, but a preferred shape is a sheet. The thickness of the foam sheet is preferably about 0.3 mm to 10 mm. More preferably, it is 0.5 mm to 5 mm. Polypropylene resin foam moldings are secondarily processed by thermoforming and are widely used in industry, mainly in various containers. Polypropylene resin foamed molded products are widely used in various applications, with the advantage of being lightweight.

  Here, since the polypropylene resin foam molded sheet contains many bubbles (cells) in the molded body, if the cells are rough or irregular, these appear on the sheet surface, deteriorating the surface appearance, and the product. The value will decline. Further, when thermoforming is performed, it is necessary to heat the mold sufficiently to transfer the mold, but in the foamed molded body, the cell also expands when heated. As a result, if the foamed cell is rough, the surface tends to deteriorate, and if it is not uniform, the molded body, particularly the sheet, is torn during heating. In order to solve these problems, it is considered necessary to form a foam cell having a high closed cell ratio, a dense and uniform size, but the polypropylene resin for foam molding or the polypropylene for foam molding of the present invention. These are realized by using the resin composition, and as the foamed sheet, a sheet having excellent appearance and high thermoformability can be obtained.

About the state of the foam cell of the polypropylene resin foam molding of this invention, the size of a cell is small and dense, the size is equal, and a state with high independence is preferable. Specifically, the average bubble diameter is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 300 μm or less. When the average cell diameter is 500 μm or less, when a polypropylene resin foam molded article, for example, a sheet-like molded article, is thermoformed, appearance defects such as perforations are less likely to occur in the thermoformed article. In addition, let an average bubble diameter be the value calculated | required using the optical microscope by the method as described in an Example.
The cell independence can be determined by the open cell ratio. The open cell ratio is preferably 30% or less, more preferably 20% or less, and still more preferably 15% or less. If the open cell ratio is 30% or less, expansion of the foam cells in the foam molded body occurs during thermoforming, and the thickness of the thermoformed body tends to increase, which is preferable. Moreover, it leads also to the improvement of the heat insulation performance of a thermoformed body.

VIII. Molded product The molded product of the present invention is a product obtained by thermoforming the above-mentioned polypropylene resin foam molded product or polypropylene resin laminated foam molded product, or a polypropylene resin foam molded material by injection molding, thermoforming, blow molding or bead foam molding. A molded product obtained by molding by any one of the methods is included.
The thermoforming method is not particularly limited. For example, plug molding, matched molding, straight molding, drape molding, plug assist molding, plug assist reverse draw molding, air slip molding, snapback molding, reverse draw. Examples thereof include molding, free drawing molding, plug-and-ridge molding, and ridge molding. VII. And VIII. A method for producing a polypropylene resin foam molded article, a polypropylene resin laminated foam molded article or a molded article using the polypropylene resin foam molding material of the present invention by the various methods described in the section is also an aspect of the present invention. .

VIIII. Use The polypropylene resin foam molded article of the present invention has uniform fine foam cells and is excellent in appearance, thermoformability, impact resistance, lightness, rigidity, heat resistance, heat insulation, oil resistance, etc. It can be suitably used for food containers such as trays, dishes and cups, vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery, and building materials.
In addition, since the polypropylene resin for foam molding and the polypropylene composition for foam molding of the present invention have a small rate of change in viscoelastic properties such as melt tension with respect to repeated heat history and shear history, the foam molded product and its molded product The scrap material produced in the process of manufacturing can be melted again and used, which is excellent in economic effect.

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

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

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

(Vi) Isotactic triad fraction (mm fraction), presence / absence of long-chain branching As described above, using JSX Corporation GSX-400, FT-NMR, paragraph [0025] of JP-A-2009-275207 ] To [0065]. The unit of mm fraction is%.
(Vii) Melting point:
Using a differential operating calorimeter (DSC), once the temperature was raised to 200 ° C. and the heat history was erased, the temperature was lowered to 40 ° C. at a rate of 10 ° C./min, and again the temperature rising rate was 10 ° C./min. The temperature at the top of the endothermic peak was measured as the melting point.

(Viii) Molecular weight distributions Mw / Mn and Mz / Mn:
It calculated | required by the following GPC measurement.
Apparatus: GPC manufactured by Waters (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 rate: 1.0 mL / min
・ Injection volume: 0.2 mL
Sample preparation: Prepare a 1 mg / mL solution using ODCB (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.
Conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve prepared in advance by 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. The calibration curve uses a cubic equation obtained by approximation by the least square method.
In addition, the following numerical value is used for the viscosity formula [η] = K × M ^α used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PP: K = 1.03 × 10 ⁻⁴ , α = 0.78

(Ix) Propylene (co) polymer (Y-1) to propylene-ethylene copolymer (Y-2) ratio, ethylene content in Y-2 Cross fractionation method and FT-IR as described in the specification It was determined by the method of combination of laws.

(X) Intrinsic viscosity of propylene-based block copolymer (Y-2) Using the CXS component of the propylene-based block copolymer (Y) obtained by the method described in (iii) above, the intrinsic viscosity is measured. went. The intrinsic viscosity was measured using an Ubbelohde capillary viscometer at a temperature of 135 ° C. and a decalin solvent.

2. Materials used 2-1. Propylene homopolymer (X)
Polypropylenes obtained in Production Examples 1 to 3 below: X1 to X3, and homopolypropylene Dapploy ^™ WB140HMS manufactured by Borealis were used as the propylene homopolymer (X).

[Production Example 1: Production of polypropylene homopolymer (X1)]
<Synthesis of catalyst component [A-1]>
Synthesis of dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl}] hafnium: (component [A-1] (complex 1 ) Synthesis):
(I) Synthesis of 4- (4-i-propylphenyl) indene To a 500 mL glass reaction vessel, 15 g (91 mmol) of 4-i-propylphenylboronic acid and 200 mL of dimethoxyethane (DME) were added, and 90 g of cesium carbonate ( 0.28 mol) and 100 mL of water were added, 13 g (67 mmol) of 4-bromoindene and 5 g (4 mmol) of tetrakistriphenylphosphinopalladium were added in this order, and the mixture was heated at 80 ° C. for 6 hours.
After allowing to cool, the reaction solution was poured into 500 mL of distilled water, transferred to a separatory funnel, and extracted with diisopropyl ether. The ether layer was washed with saturated brine and dried over sodium sulfate. Sodium sulfate was filtered, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column to obtain 15.4 g (yield 99%) of 4- (4-i-propylphenyl) indene as a colorless liquid.

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

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

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

(V) Synthesis of dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl}] hafnium In a 500 mL glass reaction vessel, 8.6 g (13 mmol) of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane and 300 mL of diethyl ether were added, and −70 ° C. in a dry ice-methanol bath. Until cooled. A 1.66 mol / L n-butyllithium-n-hexane solution (15 mL, 25 mmol) was added dropwise thereto and stirred for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, 400 mL of toluene and 40 mL of diethyl ether were added, and the mixture was cooled to −70 ° C. in a dry ice-methanol bath. Thereto was added 4.0 g (13 mmol) of hafnium tetrachloride. Thereafter, the mixture was stirred overnight while gradually returning to room temperature.
The solvent was distilled off under reduced pressure, recrystallized with dichloromethane-hexane, and dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl]. )}] 7.6 g (yield 65%) of a hafnium racemate as yellow crystals was obtained.
The identified value by ^{1 H-NMR} of the obtained racemates are described below.
¹ H-NMR (C ₆ D ₆ ) identification result Racemate: δ 0.95 (s, 6H), δ 1.10 (d, 12H), δ 2.08 (s, 6H), δ 2.67 (m, 2H) , Δ 5.80 (d, 2H), δ 6.37 (d, 2H), δ 6.74 (dd, 2H), δ 7.07 (d, 2H), δ 7.13 (d, 4H), δ 7.28 ( s, 2H), δ 7.30 (d, 2H), δ 7.83 (d, 4H).

<Synthesis of catalyst component [A-2]>
Synthesis of rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium: (synthesis of component [A-1] (complex 2)):
The synthesis of rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium is carried out according to the method described in Example 1 of JP-A-11-240909. It carried out like.

<Synthesis of catalyst component (B)>
(I) Chemical treatment of ion-exchange layered silicate In a separable flask, 96% sulfuric acid (668 g) was added to 2,264 g of distilled water, and then montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL: average particle size 19 μm) as a layered silicate ) 400 g was added. The slurry was heated at 90 ° C. for 210 minutes. When 4,000 g of distilled water was added to the reaction slurry and filtered, 810 g of a cake-like solid was obtained.
Next, 432 g of lithium sulfate and 1,924 g of distilled water were added to the separable flask to make a lithium sulfate aqueous solution, and the entire amount of the cake-like solid was charged. The slurry was reacted at room temperature for 120 minutes. 4 L of distilled water was added to the slurry, followed by filtration, further washing with distilled water to pH 5-6, and filtration. As a result, 760 g of a cake-like solid was obtained.
The obtained solid was preliminarily dried overnight at 100 ° C. under a nitrogen stream, and then coarse particles having a diameter of 53 μm or more were removed, followed by drying under reduced pressure at 200 ° C. for 2 hours to obtain 220 g of chemically treated smectite.
The composition of this chemically treated smectite is Al: 6.45 wt%, Si: 38.30 wt%, Mg: 0.98 wt%, Fe: 1.88 wt%, Li: 0.16 wt%, Al / Si = 0.175 [mol / mol].

<Preparation of prepolymerization catalyst 1>
i) Catalyst preparation and prepolymerization In a three-necked flask (volume: 1 L), 20 g of the chemically treated smectite obtained in the above catalyst component (B) was added, and heptane (132 mL) was added to form a slurry, which was then triisobutyl. Add aluminum (25 mmol: 68.0 mL of 143 mg / mL concentration of heptane solution) and stir for 1 hour, then wash with heptane until the residual liquid ratio becomes 1/100, and add heptane to a total volume of 100 mL. It was.
In another flask (volume: 200 mL), rac-dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) obtained by synthesis of the catalyst component [A-1] is used. ) -4- (4-i-propylphenyl) indenyl}] hafnium (180 μmol) was dissolved in toluene (42 mL) (solution 1), and the catalyst component [A -2] dissolved in rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium (120 μmol) in toluene (18 mL). (Solution 2).
Triisobutylaluminum (0.84 mmol: 1.2 mL of a heptane solution with a concentration of 143 mg / mL) was added to a 1 L flask containing the chemically treated smectite, and then the above solution 1 was added and stirred at room temperature for 20 minutes. Thereafter, triisobutylaluminum (0.36 mmol: 0.50 mL of a heptane solution having a concentration of 143 mg / mL) was further added, and then the above solution 2 was added, followed by stirring at room temperature for 1 hour.
Thereafter, 338 mL of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed while maintaining the temperature at 40 ° C. for 4 hours. Thereafter, propylene feed was stopped and residual polymerization was carried out for 1 hour. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (6 mmol: 17.0 mL of a heptane solution having a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes.
This solid was dried under reduced pressure for 1 hour to obtain 60.0 g of a dry prepolymerized catalyst. The prepolymerization magnification (a value obtained by dividing the amount of the prepolymerized polymer by the amount of the solid catalyst) was 2.00 g / g-catalyst.
Hereinafter, this is referred to as “preliminary polymerization catalyst 1”.

<Polymerization>
After sufficiently replacing the inside of the stirring autoclave having an internal volume of 200 liters with propylene, 40 kg of sufficiently dehydrated liquefied propylene was introduced.
Hydrogen 7.2L (0.64 g) and triisobutylaluminum (0.12 mol: 0.47 L of a heptane solution with a concentration of 50 g / L) were added thereto, and the internal temperature was raised to 70 ° C. Next, 2.4 g of the prepolymerized catalyst 1 (by weight excluding the prepolymerized polymer) was injected with argon to initiate polymerization, and the internal temperature was maintained at 70 ° C.
After 2 hours, 100 mL of ethanol was injected under pressure, unreacted propylene was purged, and the autoclave was purged with nitrogen to terminate the polymerization.
The obtained polymer was dried at 90 ° C. under a nitrogen stream for 1 hour to obtain 17.8 kg of polymer PP-1. The catalytic activity was 7.4 kg-PP / g-catalyst.

<Granulation>
The 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (trade name) is used with respect to 100 parts by weight of the polypropylene polymer PP-1 obtained by the above polymerization. : Cyanox 1790, manufactured by Nippon Cytec Industries, Ltd.) 0.05 parts by weight, Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan 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, BASF Japan Ltd.) (Company) 0.03 parts by weight and stearamide 0.09 parts by weight were mixed and stirred well, then melt kneaded at 220 ° C. using a twin screw extruder (Technobel KZW25TW-45MG-NH). The extruded strand was cut and pelletized to obtain a polypropylene homopolymer (X1).
The results of analyzing the obtained polypropylene homopolymer (X1) are shown in Table 1. As a result of ¹³ C-NMR measurement, it was confirmed that this polypropylene homopolymer (X1) had long chain branching. Further, the branching index g ′ is 0.88, and a value smaller than 1 also indicates that long chain branching is present in this polypropylene homopolymer (X1).

[Production Example 2: Production of polypropylene homopolymer (X2)]
<Polymerization>
Except that the amount of hydrogen was 7.6 L (0.68 g), the polymerization operation was performed in the same manner as in Production Example 1 to obtain 18.6 kg of polymer PP-2. The catalytic activity was 7.8 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 a polypropylene homopolymer (X2).
Table 1 shows the results of analyzing the obtained polypropylene homopolymer (X2).

[Production Example 3: Production of polypropylene homopolymer (X3)]
<Polymerization>
A polymerization operation was performed in the same manner as in Production Example 1 except that the amount of hydrogen was 9.9 L (0.88 g), to obtain 23.4 kg of polymer PP-3. The catalytic activity was 9.7 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 a polypropylene homopolymer (X3).
Table 1 shows the result of analyzing the obtained polypropylene homopolymer (X3).

2-2. Propylene block copolymer (Y)

[Production Example 4: Production of propylene-based block copolymer (Y1)]
1. Production of solid catalyst component A 10 L autoclave equipped with a stirrer was sufficiently replaced with nitrogen, and 2 L of purified toluene was introduced. Here, 200 g of diethoxymagnesium Mg (OEt) ₂ and 1 L of titanium tetrachloride were added at room temperature. The temperature was raised to 90 ° C. and 50 mL of n-butyl phthalate was introduced. Thereafter, 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.
Subsequently, the refined toluene was introduce | transduced and the whole liquid quantity was adjusted to 2L. 1 L of titanium tetrachloride was added at room temperature, the temperature was raised to 110 ° C., and the reaction was performed for 2 hours. The reaction product was thoroughly washed with purified toluene. Further, using purified n-heptane, toluene was replaced with n-heptane to obtain a slurry of a solid catalyst component.
A portion 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, a 20 L autoclave equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the solid catalyst component slurry was introduced as a solid catalyst component. Purified n-heptane was introduced to adjust the concentration of the solid catalyst component to 25 g / L. 50 mL of silicon tetrachloride SiCl ₄ was added and reacted at 90 ° C. for 1 hour. The reaction product was thoroughly washed with purified n-heptane.
Thereafter, purified n-heptane was introduced to adjust the liquid level to 4 L. Here, 30 mL of dimethyldivinylsilane, 30 mL of t-butylmethyldimethoxysilane (t-C ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) _2, and n-heptane diluted solution of triethylaluminum Et ₃ Al in Et ₃ 80 g of Al was added and reacted at 40 ° C. for 2 hours. The reaction product was thoroughly washed with purified n-heptane, and a portion of the resulting slurry was sampled and dried. Analysis, in the solid component, titanium _1.2% by weight and contained ₂ 8.8 _{wt% (t-C 4 H 9} ) (CH 3) Si (OCH 3).

Prepolymerization was performed by the following procedure using the solid component obtained above.
Purified n-heptane was introduced into the slurry, and the solid component concentration was adjusted to 20 g / L. 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 completed, the reaction was continued for another 30 minutes.
Next, the gas phase was sufficiently replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried to obtain a solid catalyst component (catalyst 1). This solid catalyst component (Catalyst 1) contained 2.5 g of polypropylene per 1 g of the solid component. Analysis, in the polypropylene obtained by removing part of the solid catalyst component (catalyst 1), titanium _1.0% by weight, _{2 (t-C 4 H 9)} (CH 3) Si (OCH 3) 8.2 It was included by weight.

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

Next, in the second reactor, propylene and ethylene were continuously supplied at a polymerization temperature of 70 ° C. and a monomer pressure of 1.5 MPa so that the molar ratio of ethylene / propylene was 0.29. In addition, hydrogen as a molecular weight control agent is continuously supplied so that the molar ratio of hydrogen / propylene is 0.0008, and ethyl alcohol is 1.17 with respect to triethylaluminum supplied to the first reactor. It supplied so that it might become a double mole.
The powder polymerized in the second reactor is continuously withdrawn into the vessel so that the amount of powder retained in the reactor is 60 kg, and the reaction is stopped by supplying nitrogen gas containing moisture. A polymer was obtained (second stage polymerization step).

  With respect to 100 parts by weight of the resulting propylene / ethylene block copolymer powder, 0.2 parts by weight of “IRGASTAB FS 301 FF” (manufactured by BASF), 1,3,5-tris (2, 6-dimethyl-3-hydroxy-4-tertiarybutylbenzoyl) isocyanate (Songwon, trade name: SONGNOX1790) 0.1 parts 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: ADK STAB PEP-36) 0.05 parts by weight, calcium stearate as neutralizing agent 0.03 weight part was added and it mixed for 5 minutes with the super mixer (made by Kawata Co., Ltd.).

Using the obtained blend, a propylene-based block copolymer (Y1) was obtained by an underwater cut granulation method under the following apparatus and conditions.
・ Twin screw extruder (Technobel KZW25TW-45MG-NH)
・ Aperture 30mm, L / D = 25 (PMS30-25 manufactured by IK Corporation)
・ Screw: Full flight CR2.0, Feed part groove depth 4mm + Dalmage ・ Screw speed: 60rpm
・ Set temperature: hopper sewage cooling, C1-C4 each 220, 200, 200, 200 ° C.
・ Die: Strand die ・ Granulation rate: 200 kg / hr
・ Cooling water temperature: 43 ℃
Screen mesh: BMT140ZZ (obtained from Ishikawa Wire Mesh Co., Ltd., special twill woven)

[Production Example 5: Production of propylene-based block copolymer (Y2)]
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 This was carried out according to Production Example 4 except that was used.

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 production procedure of the propylene / ethylene block copolymer of Production Example 4 above. In addition, the first charge of ethyl alcohol was changed so that the hydrogen / propylene molar ratio in the second-stage polymerization was 0.00015, and the molar ratio of propylene and ethylene was 0.26. Propylene / ethylene block copolymer is produced at 1.19 moles relative to triethylaluminum supplied to the reactor, and the same granulation as in Production Example 4 is carried out to produce a propylene-based block copolymer (Y2). Got.
The physical properties of Y1 and Y2 are as shown in Table 2 below.

2-3. Polypropylene resin composition [Production Example 6: Production of polypropylene resin composition (A)]
A polypropylene homopolymer (X1) and a propylene-based block copolymer (Y1) are blended at 70:30 (weight ratio) and sufficiently stirred, and then melt-kneaded under the following conditions using a single-screw extruder and extruded. The strand was 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 part groove depth 4mm + Dalmage ・ Screw rotation speed: 60rpm
Set temperature: hopper water cooling, C1 / C2 / C3 / C4 = 220/200/200/200 ° C.
・ Die: 1mmφ strand die

[Production Example 7: Production of polypropylene resin composition (B)]
A polypropylene resin composition (B) was obtained in the same manner as in Production Example 6 except that the polypropylene homopolymer was (X2).

[Production Example 8: Production of polypropylene resin composition (C)]
A polypropylene resin composition (C) was obtained in the same manner as in Production Example 6 except that the polypropylene homopolymer was (X3).

[Production Example 9: Production of polypropylene resin composition (D)]
A polypropylene resin composition (D) was obtained in the same manner as in Production Example 8, except that (Y2) was used as the propylene-ethylene block copolymer.
The physical properties of the polypropylene compositions (A) to (D) are as shown in Table 3 below.

<Examples and comparative examples>
Characteristic evaluation of the foam sheet in each example and comparative example was performed by the following method.
(1) Density A test piece was cut out from the polypropylene-based (multilayer) foamed sheet obtained in Examples and Comparative Examples, and the test piece weight (g) was divided by the volume (cm ³ ) determined from the outer dimensions of the test piece. Asked. The density was determined by measuring according to JIS K7222.
(2) Foaming Ratio A value obtained by dividing the density of the polypropylene resin by 0.9 g / cm ³ by the density of the above foamed sheet test piece was defined as the foaming ratio.
(3) Appearance evaluation of sheet Appearance evaluation of the polypropylene resin foam sheets obtained in each of Examples and Comparative Examples was evaluated according to the following criteria.
A: There are very few thickness spots and it is smooth. There is no local unevenness on the surface and it is beautiful. Bubble shape is fine.
○: There are few thickness spots. There are almost no local irregularities on the surface. Bubble shape is uniform.
Δ: There are thick spots. Bubble shape is uniform, but local irregularities are seen.
X: There are many thickness spots. Bubbles are coalesced and there are local depressions.
(4) Foamed layer cell diameter A 25 mm square sample was cut out from the polypropylene resin foam sheets obtained in the examples and comparative examples. Using a stereomicroscope (Nikon: SMZ-1000-2 type), the foam layer cross section is enlarged and projected, and from the number of bubbles and the bubble diameter in the cross section, the cross section in the extrusion direction and the bubble diameter in the cross section in the vertical direction are respectively calculated. The average value was defined as the average cell diameter of the foam layer.
(5) Open cell ratio A test piece was cut out from the polypropylene-based (multi-layer) foamed sheet obtained in Examples and Comparative Examples, and using Air Pycnometer (manufactured by Tokyo Science Co., Ltd.), according to the method described in ASTM D2856. It was measured.
The measurement of melt tension and melt flow rate is as described above.

[Example 1]
The propylene homopolymer (X1) is melted and extruded by a single screw extruder, and the extruded melt strand is sufficiently solidified in a cold water tank having a water temperature of 10 to 15 ° C. installed in the immediate vicinity of the die, and then sufficiently drained with air. While taking over with a take-up machine. The speed of the take-up machine was adjusted so that the strand diameter was about 1 mmφ, and then the pellet was cut with a fan cutter. The cut length of the strand was adjusted to be 1 to 2 times the strand diameter. Details of the extrusion conditions are as follows.
Extruder: Diameter 30 mm, L / D = 25 (IKG PMS30-25)
・ Screw: Full flight CR = 2.0, Feed part groove depth 4mm + Dalmage ・ Screw rotation speed: 30rpm
・ Set temperature: hopper water cooling, C1 / C2 / C3 / adapter / die = 230/230/230/230/230 ° C.
Die: 1 mm in diameter strand die resulting pellets were dried for 2 hours in an oven set at 100 ° C., and the pellet X1-R ₁ of repeating extrusion times = once.
When the melt tension (MT ₁ ) and melt flow rate (MFR ₁ ) were measured by the above-mentioned methods, they were 13.0 (g) and 2.1 (g / 10 min), respectively, and the original pellets (repetitive extrusion) From the ratio of the melt tension (MT ₀ ) = 23.1 (g) and the melt flow rate (MFR ₀ ) = 1.6 (g / 10 minutes) of the number of times = 0, the MT maintenance rate (MT ₁ / MT ₀ ) = 0.56, MFR change rate (MFR ₁ / MFR ₀ ) = 1.34.
Repeat the same extrusion granulation operation was pelleted X1-R ₂ in the repeating extrusion count = 2 times. Its melt tension (MT ₂ ) was 7.2 (g), and a value of MT maintenance ratio (MT ₂ / MT ₀ ) = 0.31 was obtained.
Further by repeating the same extrusion granulation operation, to obtain pellets X1-R ₃ of repetitions extrusion count = 3 times. Its melt tension (MT ₃ ) was 5.1 (g), and a value of MT maintenance factor (MT ₃ / MT ₀ ) = 0.22 was obtained. The results are shown in Table 4.

[Example 2]
Except that the propylene homopolymer was changed to X2, the same procedure as in Example 1 was repeated to obtain the number of extrusion times = 1, 2, and 3 pellets, X2-R ₁ , X2-R ₂ , and X2-R ₃ . It was. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Example 3]
Except that the propylene homopolymer was changed to X3, the same procedure as in Example 1 was repeated to obtain the number of extrusion times = 1, 2, and 3 pellets, X3-R ₁ , X3-R ₂ , and X3-R ₃ . It was. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Example 4]
Except that the polypropylene resin composition A composed of 70/30 (weight ratio) of propylene homopolymer X1 and propylene-ethylene copolymer Y1 was used, the number of times of extrusion was repeated once in the same manner as in Example 1, 2 times, 3 times the pellet to obtain _{a-R 1, a-R} 2, a-R 3. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Example 5]
Except for using polypropylene resin composition B composed of 70/30 (weight ratio) of propylene homopolymer X2 and propylene-ethylene copolymer Y1, the number of repeated extrusions was 1 in the same manner as in Example 1, 2 times to give three _pellets, the _{B-R 1, B-R} 2, B-R 3. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Example 6]
Except for using polypropylene resin composition C composed of 70/30 (weight ratio) of propylene homopolymer X3 and propylene-ethylene copolymer Y1, the number of repeated extrusions was 1 in the same manner as in Example 1, 2 times to give three _pellets, the _{C-R 1, C-R} 2, C-R 3. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Example 7]
Except for using polypropylene resin composition D composed of 70/30 (weight ratio) of propylene homopolymer X3 and propylene-ethylene copolymer Y2, the number of times of repeated extrusion = 1 times 2 in the same manner as in Example 1. times, 3 times the pellet _to obtain a _{D-R 1, D-R} 2, D-R 3. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate.

[Comparative Example 1]
Except that X4 was used as the propylene homopolymer, the number of repeated extrusions was 1, 2, and 3 pellets, X4-R ₁ , X4-R ₂ , and X4-R ₃ in the same manner as in Example 1. Obtained. Table 4 shows the results of MT, MFR, MT maintenance rate, and MFR change rate. MT greatly decreased after one repetition of extrusion, and each MT maintenance rate also became a low value. The MFR also increased greatly after one extrusion and the MT change rate became a large value.

Foaming examples and comparative examples (circular foaming)
[Example 8]
100 parts by weight of the propylene homopolymer (X2) and 0.5 parts by weight of a chemical foaming agent (trade name: Polyslen EE275F, manufactured by Eiwa Chemical Co., Ltd.) as a bubble adjusting agent are stirred and mixed uniformly with a ribbon blender, and the screw diameters are respectively It put into a 40 mmΦ and 50 mmΦ tandem type extruder. While the resin was heated and melted and plasticized by setting the cylinder setting temperature of the first stage extruder to 230 ° C., 0.88 parts by weight of isobutane / isobutane / 1008 parts by weight of the mixture was dissolved while 100 parts by weight of the mixture was decomposed. Normal butane = 60/40 wt%) was injected and kneaded with a high-pressure pump to obtain a polypropylene resin composition for foam molding, and then the second stage extruder was set at 180 ° C. to quickly cool it, and at the tip of the extruder The propylene resin composition was extruded from the attached circular die (setting temperature 175 ° C., aperture 50 mmφ, gap = 0.75 mm) into the atmosphere and foamed. The rotational speed of the first stage extruder was 90 rpm, and the rotational speed of the second stage extruder was 6 rpm.
The foam extruded from the die was passed through a cooling mandrel having an outer diameter of 120 mmφ that passed water at a temperature of 10 ° C. to cool the inner surface, and at the same time, the outer surface was cooled by blowing air from an air ring attached in the immediate vicinity of the die. Thereafter, the sheet was cut open with a rotary cutter, the thickness was adjusted at the speed of the take-up roll, and the sheet was taken up with a pinch roll and take-up roll. The obtained foamed sheet had a density of 0.18 g / cm ³ , an average cell diameter of 80 μm, an open cell ratio of 7%, little corrugation, and good appearance. Table 5 shows the evaluation results of the obtained foamed sheet.

[Example 9]
A foam sheet was produced in the same manner as in Example 8 except that the propylene homopolymer was X2-R ₁ (pellets obtained by repeatedly extruding X2 once). The obtained foamed sheet had a density of 0.19 g / cm ³ , an average cell diameter of 100 μm, an open cell ratio of 15%, little corrugation, and good appearance. Table 5 shows the evaluation results of the obtained foamed sheet.

[Comparative Example 2]
A foam sheet was produced in the same manner as in Example 8, except that the propylene homopolymer was X4 and the setting temperature of the second stage extruder was 175 ° C. The obtained foamed sheet had a density of 0.18 g / cm ³ , an average cell diameter of 80 μm, an open cell ratio of 10%, and no corrugation occurred, but local irregularities were observed on the sheet surface. Table 5 shows the evaluation results of the obtained foamed sheet.

[Comparative Example 3]
A foam sheet was produced in the same manner as in Comparative Example 2 except that the propylene homopolymer was X4-R ₁ (pellets obtained by repeatedly extruding X4 once). The obtained foamed sheet had a density of 0.25 g / cm ³ , an average cell diameter of 70 μm, an open cell ratio of 35%, and surface roughness thought to be due to foaming in the die. Table 5 shows the evaluation results of the obtained foamed sheet.

  As is clear from Table 5, the polypropylene resin composition having the MT retention rate of the present invention maintains a high expansion ratio and a low open cell ratio even after undergoing an extrusion melting operation, and is good as a resin for foam molding. It was shown that it maintained the proper properties. Thereby, it was shown that the polypropylene resin of the present invention has excellent foam moldability and is suitable for repeated molding.

Claims (16)

The melt tension MT _{0 at} 230 ° C. is 3 g or more, and the melt tension MT ₁ at 230 ° C. after one extrusion granulation operation at 230 ° C. is 0.3 when MT ₀ is 1. A polypropylene resin for foam molding comprising the propylene homopolymer (X) as described above. The melt tension MT ₂ at 230 ° C after performing the extrusion granulation operation at 230 ° C twice includes a propylene homopolymer (X) that is 0.2 or more when MT ₀ is 1. 1. Polypropylene resin for foam molding as described in 1. The melt tension MT ₃ at 230 ° C. after performing the extrusion granulation operation at 230 ° C. three times includes a propylene homopolymer (X) that is 0.1 or more when MT ₀ is 1. 2. Polypropylene resin for foam molding according to 2. The melt flow rate MFR ₀ (230 ° C., 2.16 kg) of the propylene homopolymer (X) is in the range of 0.9 to 15 g / 10 min, and the extrusion granulation operation at 230 ° C. was performed once. The foam molding according to any one of claims 1 to 3, wherein a melt flow rate MFR ₁ (230 ° C, 2.16 kg) of a later propylene homopolymer is 2 or less when MFR ₀ is 1. Polypropylene resin. The polypropylene resin for foam molding according to any one of claims 1 to 4, wherein the propylene homopolymer (X) satisfies the following characteristics (X-i) to (X-iv).
Characteristic (Xi) Long chain branching.
Characteristic (X-ii) The melt tension at 230 ° C. is 3 to 25 g.
Characteristic (X-iii) Melt flow rate (230 ° C., 2.16 kg) is 0.9 to 15 g / 10 min.
Characteristic (X-iv) The amount of xylene-soluble components (CXS) at 25 ° C. is less than 5 wt% with respect to the total amount of the propylene homopolymer (X).   It contains 10 to 99 wt% of the propylene homopolymer (X) according to any one of claims 1 to 5 and 1 to 90 wt% of the propylene-based block copolymer (Y), and has a melt tension of 1 g or more at 230 ° C. A polypropylene resin composition for foam molding. The propylene-based block copolymer (Y) comprises a propylene (co) polymer (Y-1) and a propylene-ethylene copolymer (Y-2) which may contain a comonomer of 10 wt% or less, and has the following characteristics ( The polypropylene resin composition for foam molding according to claim 6, which satisfies Yi) to (Yv).
Characteristic (Yi) When the total amount of the propylene-based block copolymer (Y) is 100 wt%, 50 to 99 wt% of the propylene (co) polymer (Y-1) which may contain a comonomer of 10 wt% or less, 1-50 wt% of propylene ethylene copolymer (Y-2) is contained.
Characteristic (Y-ii) Melt flow rate (230 ° C., 2.16 kg) is 0.1 to 200 g / 10 min.
The characteristic (Y-iii) melting point is 155 ° C. or higher.
Characteristic (Y-iv) The ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 38 wt%.
Property (Yv) The intrinsic viscosity of propylene-ethylene copolymer (Y-2) in decalin at 135 ° C. is 5.3 dl / g or more.   The polypropylene resin composition for foam molding according to claim 7, wherein the propylene-based block copolymer (Y) is produced by a sequential polymerization method.   The foaming agent is added in an amount of 0. 0 to 100 parts by weight of the polypropylene resin for foam molding according to any one of claims 1 to 5 or the polypropylene resin composition for foam molding according to any one of claims 6 to 8. Polypropylene resin foam molding material containing 05 to 6.0 parts by weight.   A polypropylene resin foam molded article obtained by extruding the polypropylene resin foam molding material according to claim 9.   A polypropylene resin laminated foam molded article obtained by co-extrusion of a foamed layer comprising the polypropylene resin foam molded article according to claim 10 and a non-foamed layer comprising a thermoplastic resin composition.   The polypropylene resin laminated foam molded article according to claim 11, 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.   The polypropylene resin foam molded article according to any one of claims 10 to 12, which is in a sheet form.   A molded article formed by thermoforming the polypropylene resin foam molded article or the laminated foam molded article according to any one of claims 10 to 12.   A molded product obtained by molding the polypropylene resin foam molding material according to claim 9 by any one of injection molding, thermoforming, blow molding or bead foam molding.   Use of the polypropylene resin for foam molding according to any one of claims 1 to 5 or the polypropylene resin composition for foam molding according to any one of claims 6 to 8 for production of a foam sheet.