JP2021014110A - Polypropylene resin multilayer foamed sheet - Google Patents

Abstract

To provide a polypropylene resin multilayer foamed sheet for obtaining a polypropylene resin multilayer foam having uniform and fine foamed cells and good appearance of a molded article.SOLUTION: There is provided a polypropylene resin multilayer foamed sheet which comprises a foam layer composed of a polypropylene resin composition for expansion molding containing 0.05 to 6.0 pts.wt. of a foaming agent based on 100 wt.% of a polypropylene resin composition (provided that the total of (X), (Y) and (Z) is 100 wt.%) comprising 67.5 to 2.5 wt.% of a polypropylene resin (X) having a specific long-chain branched structure, 2.5 to 67.5 wt.% of a propylene-based block copolymer (Y) which is a multistage polymer composed of a specific propylene (co)polymer (Y-1) and a propylene-ethylene copolymer (Y-2) and 10 to 65 wt.% of a specific propylene-α-olefin random copolymer (Z), a PP filler layer containing an inorganic filler and a surface layer composed of a thermoplastic resin composition.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention can provide a foamed sheet in which the foamed cells have high closed cell properties during foam molding, the cells are dense and the sizes are relatively uniform, and in particular, high foaming of 3.0 times or more by the T-die method. The present invention relates to a polypropylene (PP) filler layer containing a magnification foam layer, a polypropylene (PP) filler layer containing an inorganic filler, a polypropylene-based resin multilayer foamed sheet containing a surface layer, and a molded article thermoformed using the same.

Foam molding is one of the important molding methods for polypropylene resin. Various molded bodies obtained by extrusion foam molding and injection foam molding are used in a wide range of applications by taking advantage of excellent properties such as heat insulation, sound insulation, cushioning, and energy absorption. Especially in recent years, from the viewpoint of environmental issues, weight reduction of materials and reduction of environmental load have become important technological development issues, and the technical fields in which foamed molded products are used tend to expand, and the demand for resins with high foaming performance is increasing. , Is getting stronger.
Bubble diameter and bubble morphology are important factors for foaming performance. Especially in the fields of food packaging and containers, thermoformability, heat insulation, rigidity and high appearance (high design) are required. Therefore, in general, the foaming ratio is high, and the fineness, independence and uniformity are achieved. It is important to produce a foam sheet with high air bubbles.
In general, foam sheets obtained by extrusion foam molding are used for applications such as food foam trays and foam containers, and among the extrusion foam molding, there are a T-die method and a round die method. When the T-die method is used, there is an advantage that the surface of the foamed sheet becomes smooth and the appearance and thermoformability are improved by cooling the foamed resin with a cooling roll immediately after extrusion. Further, if the cooling roll is a mirror surface roll, it is possible to manufacture a foamed sheet having excellent gloss. As described above, it has the advantages of having a relatively good appearance and smoothness and good thermoforming property as compared with the round die method described later, but when the foamed resin discharged from the die is taken up by a roll. Since the width is restricted and the molding method stretches the foam more strongly than the round die foaming, the bubbles are likely to be crushed or broken, and it is difficult to obtain a sheet having high bubble independence. In particular, as the sheet has a high foaming ratio exceeding 3.0 times, the proportion of bubbles in the resin increases and the foaming speed increases, so that the bubbles are likely to coalesce and the bubbles It becomes difficult to maintain independence and high appearance.
Further, in order to improve the heat insulating property, it is necessary to increase the foaming ratio, but as the foaming ratio increases, the seat rigidity decreases. For the purpose of improving the rigidity of such a foamed sheet, a method of laminating a non-foamed filler layer (PP filler layer) in which an inorganic filler is added to PP is widely known. The non-foamed layer containing an inorganic filler has higher rigidity than the foamed layer, and by laminating this layer on the foamed layer, a so-called sandwich effect can be obtained, and a foamed sheet having high rigidity in terms of sheet specific gravity can be obtained. Be done.
For materials with excellent extrusion foamability, a specific propylene-ethylene block copolymer polymerized with a Ziegler-Natta catalyst is blended with a long-chain branched polypropylene having a high melt tension suitable for foam molding. Materials have been developed for the purpose of achieving both foaming properties and container appearance (Patent Documents 1 to 3).
On the other hand, in extrusion molding represented by the T-die method, in order to increase productivity, it is common practice to increase the screw rotation speed of the extruder to increase the sheet take-up speed. In an environment where a sheet is formed with a discharge rate and a high line speed, in addition to the factors caused by the high foaming ratio described above, the shear heat generation of the resin also increases, the resin temperature tends to rise, and the take-up speed also increases. By raising the foam sheet, excessive tension is generated, and bubbles are likely to be crushed, coalesced, and ruptured. Further, when the above-mentioned PP filler layer is laminated, the heat capacity of the inorganic filler contained in the PP filler layer is larger than that of PP, so that cooling is slowed down and bubbles are easily broken. Under such an environment, it is difficult to obtain a sheet having a good appearance, which has a foam layer of 3.0 times or more, particularly by the T-die method, with conventional materials, and foam having good foaming characteristics and a high appearance. There was a strong demand for the development of materials for obtaining sheets.

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

An object of the present invention is to obtain a uniform and fine foam cell particularly containing a PP filler layer and extruded using a T-die even if the foaming ratio of the foamed layer is 3.0 times or more in view of the current state of the prior art. It is an object of the present invention to provide a polypropylene-based resin multilayer foamed sheet for obtaining a polypropylene-based resin multilayer foam having a good appearance of a molded product, and to provide a molded product thermoformed using the polypropylene-based resin multilayer foamed sheet.

As a result of intensive studies to solve the above problems, the present inventors have made a multi-stage weight composed of a polypropylene resin having a specific long-chain branched structure, a specific propylene (co) polymer, and a propylene-ethylene copolymer. A polypropylene-based resin composition containing a coalesced propylene-based block copolymer and a propylene-α-olefin random copolymer component polymerized with a specific Cheegler-Natta catalyst in a specific blending amount is used for the foam layer. As a result, even if the foamed layer contains a PP filler layer and the foaming ratio of the foamed layer is set to 3.0 times or more by the T-die foaming method, a foamed polymer having uniform and fine foamed cells and a good appearance of the molded product can be obtained. We have found that it can be obtained and have completed the present invention.

That is, according to the first invention of the present invention, a foamed layer made of a polypropylene resin composition for foam molding containing 0.05 to 6.0 parts by weight of a foaming agent with respect to 100 parts by weight of the polypropylene resin composition. A polypropylene-based resin multilayer foamed sheet comprising a PP filler layer containing an inorganic filler and a surface layer made of a thermoplastic resin composition.
The polypropylene-based resin composition contains 67.5 to 2.5% by weight of the polypropylene resin (X) having the following characteristics (X-i) to (X-iv) and having a long-chain branched structure, as described below. (Y-i) to (Yv), propylene-based, which is a multi-stage polymer composed of a propylene (co) copolymer (Y-1) and a propylene-ethylene copolymer (Y-2). A block copolymer (Y) of 2.5 to 67.5% by weight and a propylene-α-olefin random copolymer (Z) having the following properties (Z-i) to (Z-iii) are used. Provided is a polypropylene-based resin multilayer foamed sheet containing 10 to 65% by weight (however, the total of (X), (Y), and (Z) is 100% by weight).
(X-i) MFR is 0.1 to 30.0 g / 10 minutes.
(X-ii) The molecular weight distribution Mw / Mn by GPC is 3.0 to 10.0, and Mz / Mw is 2.5 to 10.0.
(X-iii) The melt tension (MT) (unit: g) satisfies either log (MT) ≧ −0.9 × log (MFR) +0.7 or MT ≧ 15.
(X-iv) The amount of the paraxylene-soluble component (CXS) at 25 ° C. is less than 5.0% by weight based on the total weight of the polypropylene resin (X).
The ratio of (Y-i) (Y-1) to (Y-2) is 50 to 99% by weight for (Y-1) and 1 to 50% by weight for (Y-2) (however, propylene). The total weight of the block copolymer (Y) is 100% by weight).
The MFR of the (Y-ii) propylene block copolymer (Y) is 0.1 to 200.0 g / 10 minutes.
The melting peak temperature of the (Y-iii) propylene-based block copolymer (Y) exceeds 155 ° C.
The ethylene content in the (Y-iv) propylene-ethylene copolymer (Y-2) is 11 to 60% by weight (however, the total weight of the constituent monomers of the propylene-ethylene copolymer (Y-2) is taken. 100% by weight.).
The intrinsic viscosity of the (Yv) propylene-ethylene copolymer (Y-2) in decalin at 135 ° C. is 5.3 dl / g or more.
(Z-i) Polymerized with a Ziegler-Natta catalyst.
(Z-ii) The melting peak temperature measured by DSC is 157 ° C or lower.
(Z-iii) MFR is 21.0 g / 10 minutes or more.

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

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

Further, according to the fourth invention of the present invention, there is provided a molded body characterized in that the multilayer foamed sheet according to any one of the first to third inventions is thermoformed.

Further, according to a fifth invention of the present invention, it is a molded body obtained by molding a multilayer foamed sheet according to any one of the first to third inventions, and comprises the polypropylene-based resin composition for foam molding. Provided is a molded product obtained by molding the foam layer by any of an injection molding method, a heat molding method, an extrusion molding method, a blow molding method or a bead foam molding method.

The polypropylene-based resin multilayer foamed sheet of the present invention contains a PP filler layer, especially in a foamed sheet obtained by a T-die molding method, and even if the foamed layer has a high foaming ratio of 3.0 times or more, uniform and fine foaming is performed. It has the characteristic that a cell can be obtained, and has the characteristic that a molded product having a good appearance can be obtained.
The polypropylene-based resin multilayer foamed sheet of the present invention and the thermoformed body using the same have an excellent balance between foaming characteristics and rigidity, and a uniform and fine foamed cell can be obtained, and the appearance, thermoforming property, impact resistance, and light weight are obtained. Due to its excellent properties, heat resistance, heat insulation, oil resistance, etc., it is suitably used for food containers such as trays, plates and cups, vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery and building materials. can do.

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

The polypropylene-based resin multilayer foamed sheet of the present invention includes a foamed layer made of a polypropylene-based resin composition for foam molding, a PP filler layer containing an inorganic filler, and a surface layer made of a thermoplastic resin composition.
Here, the polypropylene-based resin composition for foam molding used in the present invention contains 0.05 to 6.0 parts by weight of a foaming agent with respect to 100 parts by weight of the polypropylene-based resin composition.
Further, the polypropylene-based resin composition used in the present invention (hereinafter, may be referred to as "resin composition used in the present invention") has the following characteristics (X-i) to (X-iv). However, the polypropylene resin (X) having a long-chain branched structure is 67.5 to 2.5% by weight, and has the following properties (Yi) to (Yv), and is a propylene (co) polymer (co) polymer. 2.5 to 67.5% by weight of the propylene-based block copolymer (Y), which is a multistage polymer composed of Y-1) and the propylene-ethylene copolymer (Y-2), and the following (Z-). It is characterized by containing 10 to 65% by weight of a propylene-α-olefin random copolymer (Z) having the characteristics of i) to (Z-iii) (however, (X), (Y), (Z). ) Is 100% by weight).
In the following, the characteristics to be satisfied by the components (X), (Y), and (Z) will be described in detail for each item.

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

1. 1. Characteristic (X-i): MFR
The melt flow rate (MFR) of the polypropylene resin (X) having a long-chain branched structure in the present invention needs to be in the range of 0.1 to 30.0 g / 10 minutes, preferably 0.3 to 20 minutes. It is 0.0 g / 10 minutes, more preferably 0.5 to 10.0 g / 10 minutes. When the MFR of polypropylene resin (X) is 0.1 g / 10 minutes or more, problems such as an excessively high load on the extruder for various moldings due to insufficient fluidity are unlikely to occur, while 30.0 g / 10 When it is less than a minute, the tension is sufficient, the characteristics as a high melt tension material are good, and the material is suitable.
The MFR is defined in JIS K7210: 1999 "Plastic-Test Method for Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Thermoplastics", Annex A, Table 1, Condition M (230 ° C, 2.16 kg). It was measured according to (load), and the unit is g / 10 minutes.

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

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

3. 3. Characteristic (X-iii): Melt tension (MT)
Further, the polypropylene resin (X) having a long-chain branched structure needs to satisfy the following condition (1).
・ Condition (1)
log (MT) ≧ -0.9 × log (MFR) +0.7
Or MT ≧ 15
At least one of them is satisfied.
Here, MT uses Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd., Capillary: Diameter 2.0 mm, Length 40 mm, Cylinder diameter: 9.55 mm, Cylinder extrusion speed: 20 mm / min, Pick-up speed: 4.0 m. It represents the melt tension when measured under the conditions of / min and temperature: 230 ° C., and the unit is grams. However, when the MT of the component (X) is extremely high, the resin may break at a pick-up speed of 4.0 m / min. In such a case, the pick-up speed is reduced and the pick-up speed is the highest. Let MT be the tension at the speed of. The measurement conditions and units of MFR are as described above.
This regulation is an index for polypropylene resin (X) having a long-chain branched structure to have sufficient melt tension for foam molding, and in general, MT has a correlation with MFR, and therefore MFR. It is described by the relational expression with.
As described above, the method of defining MT by the relational expression with MFR is a usual method for those skilled in the art, and for example, Japanese Patent Application Laid-Open No. 2003-25425 describes polypropylene having a high melt tension as follows. The relational expression of is proposed.
log (MS)> -0.61 x log (MFR) +0.82 (230 ° C)
(Here, MS is synonymous with the above MT.)
Further, Japanese Patent Application Laid-Open No. 2003-64193 proposes the following relational expression as a definition of polypropylene having a high melt tension.
11.32 x MFR ^-0.7854 ≤ MT (230 ° C)
Further, Japanese Patent Application Laid-Open No. 2003-94504 proposes the following relational expression as a definition of polypropylene having a high melt tension.
MT ≧ 7.52 × MFR ^-0.576
(MT is a value measured at 190 ° C. and MFR is a value measured at 230 ° C.)

If the polypropylene resin (X) having a long-chain branched structure satisfies the above condition (1), it can be said that the polypropylene resin (X) has a sufficiently high melt tension and is useful for foam molding. Further, it is more preferable to satisfy the following condition (1)', and it is further preferable to satisfy the condition (1)'.
・ ・ Condition (1)'
log (MT) ≧ -0.9 × log (MFR) +0.9
Or MT ≧ 15
At least one of them is satisfied.
・ ・ Condition (1) ”
log (MT) ≧ -0.9 × log (MFR) +1.1
Or MT ≧ 15
At least one of them is satisfied.
It is not necessary to set the upper limit value of MT in particular, but when MT is 40 g or less, the collection speed is not significantly slowed by the above measurement method, and measurement becomes easy. In such a case, since the spreadability of the resin is also considered to be good, it is preferably 40 g or less, more preferably 35 g or less, and most preferably 30 g or less.

4. Characteristic (X-iv): 25 ° C. Paraxylene-soluble component amount (CXS)
The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has few low crystallinity components that cause stickiness and bleed-out when it is produced. This low crystalline component is assessed by a 25 ° C. xylene soluble component amount (CXS), which needs to be less than 5.0% by weight, preferably less than 5.0% by weight, based on the total weight of the component (X). It is 3.0% by weight or less, more preferably 1.0% by weight or less, and further preferably 0.5% by weight or less. The lower limit is not particularly limited, but is usually 0.01% by weight or more, preferably 0.03% by weight or more. The details of the CXS measurement method are as follows.
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml BHT) at 130 ° C. to prepare a solution, and then left at 25 ° C. for 12 hours. Then, the precipitated polymer is filtered off, p-xylene is evaporated from the filtrate, and the mixture is further dried under reduced pressure at 100 ° C. for 12 hours to recover the xylene-soluble component at room temperature. The ratio [% by weight] of the weight of the recovered component to the weight of the charged sample is defined as CXS.

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

5. Characteristic (X-v): Branch index g'
As a direct indication of having a polypropylene resin (X) is a long-chain branched structure having a long-chain branched structure, it is possible to increase the branching index g ^'. g ^'is the intrinsic viscosity [eta] ratio of lin of a linear polymer having the same molecular weight as the intrinsic viscosity [eta] br polymers having long chain branching structure, i.e., given by [η] br / [η] lin , If a long-chain branched structure is present, it takes a value less than 1.
The definition of the branching index g'is described in, for example, "Developments in Polymer Charation-4" (JV Dawkins ed. Applied Science Publicers, 1983) and is a well-known index to those skilled in the art.

g ^', for example, by using a GPC equipped with a light scattering meter and viscometer as referred to below in the detector can be obtained as a function of absolute molecular weight Mabs.
The polypropylene resin (X) having a long-chain branched structure used in the present invention preferably has a g'of 0.30 or more and less than 0.95 when the absolute molecular weight Mabs determined by light scattering is 1,000,000. It is preferably 0.55 or more and less than 0.95, more preferably 0.75 or more and less than 0.95, and most preferably 0.78 or more and less than 0.95.
As described in detail below, the polypropylene resin (X) having a long-chain branched structure used in the present invention is considered to form a comb-shaped chain as a molecular structure due to its polymerization mechanism, and g'is 0.30 or more. If this is the case, the number of main chains is small and the proportion of side chains is not extremely large. In such a case, the melt tension is improved and there is no risk of gel formation, which is preferable in foam molding. On the other hand, when g'is less than 0.95, since there are branches, the melt tension does not tend to be insufficient, and it is suitable for foam molding.

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

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

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

[Calculation of branch index (g')]
The branching index (g') is the ratio of the ultimate viscosity ([η] br) obtained by measuring a sample with the above Viscometer to the limit viscosity ([η] lin) obtained by separately measuring a linear polymer. It is calculated as ([η] br / [η] lin).
When a long-chain branched structure is introduced into a polymer molecule, the radius of inertia becomes smaller as compared with a linear polymer molecule having the same molecular weight. As the radius of inertia decreases, the ultimate viscosity decreases. Therefore, as the long-chain branched structure is introduced, the ultimate viscosity ([η] br) of the branched polymer with respect to the ultimate viscosity ([η] lin) of the linear polymer having the same molecular weight. The ratio of ([η] br / [η] lin) becomes smaller.
Therefore, when the branch index (g'= [η] br / [η] lin) is less than 1.0, it means that branching has been introduced. Here, as the linear polymer for obtaining [η] lin, commercially available homopolypropylene (Novatec PP (registered trademark) grade name: FY6 manufactured by Japan Polypropylene Corporation) is used. Since it is known as the Mark-Houwink-Sakurada formula that the logarithm of [η] lin of a linear polymer has a linear relationship with the logarithm of molecular weight, [η] lin is appropriately set on the low molecular weight side or the high molecular weight side. Numerical values can be obtained by extrapolation.

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

The details of the method for measuring the mm fraction of 3 chains of propylene units by ¹³ C-NMR are as follows.
375 mg of the sample is completely dissolved in 2.5 ml of deuterated 1,1,2,2-tetrachloroethane in an NMR sample tube (10φ), and then measured at 125 ° C. by the proton complete decoupling method. The chemical shift sets the central peak of the three peaks of deuterated 1,1,2,2-tetrachloroethane to 74.2 ppm. Chemical shifts of other carbon peaks are based on this.
Flip angle: 90 degrees Pulse interval: 10 seconds Resonance frequency: 100 MHz or more Accumulation frequency: 10,000 times or more Observation range: -20 ppm to 179 ppm
Number of data points: 32768
The mm fraction analysis is performed using the ¹³ C-NMR spectrum measured under the above conditions.
The spectrum is assigned with reference to Macromolecules, (1975), 8 squares, p. 687 and Polymer, Vol. 30, p. 1350 (1989).
A more specific method for determining the mm fraction is described in detail in paragraphs [0053] to [0065] of JP2009-275207A, and this method is also used in the present specification. To do.
In the present invention, a polypropylene resin having a characteristic (X-iii) satisfying log (MT) ≧ −0.9 × log (MFR) +0.7 and Mabs satisfying g ′ <1 at 1 million is a long chain. It can be said that it has a branched structure.

7. Characteristics: Blending amount of polypropylene resin (X) having a long-chain branched structure The blending amount of polypropylene resin (X) having a long-chain branched structure is 67.5 to 2.5% by weight, preferably 60.0 to 10%. It is 0% by weight, more preferably 55.0 to 15.0% by weight, still more preferably 52.5 to 17.5% by weight (however, the total of (X), (Y), and (Z) is 100% by weight. %). When the blending amount of the polypropylene resin (X) having a long-chain branched structure is within this range, shear heat is generated even at a high foaming ratio that is formed at high speed by the T-die method and exceeds 3.0 times. The load applied to the sheet can be reduced by the shearing tension, and a foamed sheet having excellent air bubble independence and denseness and high appearance can be obtained. Further, when the compounding amount is 67.5% by weight or less, the fluidity is sufficient, there is no problem that the load of the extruder is too high for various moldings, and the amount is 2.5% by weight or more. , The melt tension becomes sufficient, and the properties as a high melt tension material are excellent, which makes it suitable for foam molding.

8. Method for producing polypropylene resin (X) having a long-chain branched structure The polypropylene resin (X) having a long-chain branched structure is described in (X-i) to (X-iv) and preferably (X-v) described above. As long as the characteristics of ~ (X-vi) are satisfied, the production method is not particularly limited, but as described above, high stereoregularity, low low crystallinity component amount, relatively wide molecular weight distribution, branching index g ^'. A preferable production method for satisfying all the conditions such as the above range and high melt tension is a method using a macromer copolymerization method using a combination of metallocene catalysts. Examples of such a method include the methods disclosed in JP-A-2009-57542.
In this method, polypropylene having a long-chain branched structure is produced by using a catalyst that combines a catalyst component having a specific structure having a macromer-forming ability and a catalyst component having a specific structure having a macromer copolymerization ability at a high molecular weight. According to this method, an industrially effective method such as a bulk polymerization method or a gas phase polymerization method can be used for single-stage polymerization under particularly practical pressure-temperature conditions, and hydrogen, which is a molecular weight modifier, can be used. By using this, it is possible to produce a polypropylene resin having a long-chain branched structure having the desired physical properties.
Further, conventionally, it has been necessary to increase the branch generation efficiency by reducing the crystallinity by using a polypropylene component having low stereoregularity, but in the above method, a polypropylene component having sufficiently high stereoregularity has been used. , (X-vi) and (X) relating to high stereoregularity and low crystallinity components, which can be introduced into the side chain by a simple method and are preferable as the polypropylene resin (X) used in the present invention. -Iv) is suitable for satisfying the characteristics.
Further, by using the above method, the molecular weight distribution can be widened by using two kinds of catalysts having significantly different polymerization characteristics, which is necessary for the polypropylene resin (X) having a long chain branched structure used in the present invention (X-). i) It is possible to satisfy the characteristics of (X-iii) at the same time, which is preferable.

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

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

In the general formula (a1), R ¹¹ and R ¹² each independently represent a heterocyclic group containing nitrogen, oxygen, or sulfur having 4 to 16 carbon atoms. Further, R ¹³ and R ¹⁴ may each independently contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus or a plurality of heteroelements selected from these aryls having 6 to 16 carbon atoms. Represents a group, a heterocyclic group containing nitrogen, oxygen, or sulfur having 6 to 16 carbon atoms. Further, X ¹¹ and Y ¹¹ independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, and a halogenation having 1 to 20 carbon atoms. hydrocarbon group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group or a nitrogen-containing hydrocarbon group having a carbon number of 1 to 20, Q ¹¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, Represents a silylene group or a gelmilene 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. It is a substituted 2-furfuryl group, more preferably a substituted 2-furyl group.
Further, as the substituent of the substituted 2-furyl group, the substituted 2-thienyl group and the substituted 2-furfuryl group, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group and a propyl group can be used. Examples thereof include a halogen atom such as a fluorine atom and a chlorine atom, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group, and a trialkylsilyl group. Of these, a methyl group and a trimethylsilyl group are preferable, and a methyl group is particularly preferable.
In addition, R ¹¹ and R ¹² are particularly preferably 2- (5-methyl) -frill groups. Further, it is preferable that R ¹¹ and R ¹² are the same as each other.
Examples of the aryl group having 6 to 16 carbon atoms of R ¹³ and R ¹⁴ and which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected from these are selected. One or more hydrocarbon groups having 1 to 6 carbon atoms, silicon-containing hydrocarbon groups having 1 to 6 carbon atoms, and halogens having 1 to 6 carbon atoms on the aryl cyclic skeleton within the range of 6 to 16 carbon atoms. It may have a contained hydrocarbon group as a substituent.

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

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

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

Among the compounds represented by the general formula (a1), preferred compounds are specifically exemplified below.
Dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-thienyl) -4-phenyl] -Indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-diphenylsilylenebis {2 -(5-Methyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylgermilenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl} ] Hafnium, dichloro [1,1'-dimethylgelmilenebis {2- (5-methyl-2-thienyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-( 5-t-Butyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-trimethylsilyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-phenyl-2-furyl) -4-phenyl-indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (4,4) 5-Dimethyl-2-furyl) -4-phenyl-indenyl}] hafnium dichloride, dichloro [1,1'-dimethylsilylenebis {2- (2-benzofuryl) -4-phenyl-indenyl}] hafnium, dichloro [1 , 1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5- (5-) Methyl-2-furyl) -4- (4-ipropylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4- (4-) Methylsilylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furfuryl) -4-phenyl-indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-Methyl-2-furyl) -4- (4-chlorophenyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4) -Fluorophenyl ) -Indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trifluoromethylphenyl) -indenyl}] hafnium, dichloro [1, 1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-t-butylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2) -Frill) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl) -4- (2-phenanthryl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (2-furyl)- 4- (9-phenanthryl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (2-naphthyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5) -Methyl-2-furyl) -4- (2-phenanthryl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (9-phenanthrill) ) -Indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (1-naphthyl) -indenyl}] hafnium, dichloro [1,1 '-Dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (2-naphthyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t) -Butyl-2-furyl) -4- (2-phenanthryl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (9) -Fenanceril) -Indenyl}] Hafnium, etc.

Of these, more preferred are dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium, dichloro [1,1'-dimethylsilylene. Bis {2- (5-methyl-2-furyl) -4- (4-methylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-ipropylphenyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trimethylsilylphenyl) -indenyl} ] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-chlorophenyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis { 2- (5-Methyl-2-furyl) -4- (2-naphthyl) -indenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-t-Butylphenyl) -indenyl}] hafnium.
Particularly preferred are dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] naphthium, dichloro [1,1'-dimethylsilylenebis { 2- (5-Methyl-2-furyl) -4- (4-ipropylphenyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl)- 4- (4-Trimethylsilylphenyl) -indenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-t-butylphenyl) -indenyl} ] Hafnium.

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

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

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

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

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

Further, Q ²¹ is a bonding group that bridges two conjugated five-membered ring ligands, and has a divalent hydrocarbon group having 1 to 20 carbon atoms and a hydrocarbon group having 1 to 20 carbon atoms. It is a gelmilene group having a silylene group or a hydrocarbon group having 1 to 20 carbon atoms, preferably a substituted silylene group or a substituted gelmilene group.

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

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

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

Dichloro {1,1'-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazurenyl)} hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4 -Hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis { 2-Methyl-4- (4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chloro-4-t-butylphenyl)- 4-Hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl-4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1' -Dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl) -4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (1-naphthyl) -4-hydroazulenyl}] hafnium, dichloro [1,1' -Dimethylsilylenebis {2-methyl-4- (2-naphthyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethyl Silyrenbis {2-methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (9-phenanthril) -4 -Hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-n −propyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] Huff Nium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis { 2-Ethyl-4- (3-Methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1'-dimethylgermilenebis {2-methyl-4- (2-fluoro-4-biphenylyl) ) -4-Hydroazurenyl}] hafnium, dichloro [1,1'-dimethylgelmilenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'- (9-Silafluorene-9,9-diyl) Bis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] Hafnium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-Chloro-2-naphthyl) -4-hydroazulenyl}] hafnium, dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium , Dichloro [1,1'-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, etc. Can be mentioned.

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

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

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

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

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

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

<Salt treatment>:
40% or more, preferably 60% or more of the cations of the exchangeable periodic table 1 metal contained in the ion-exchangeable layered silicate before being treated with salts, with the cations dissociated from the salts shown below. , Ion exchange is preferred.
The salts used in the salt treatment for the purpose of such ion exchange are composed of cations containing at least one atom selected from the group consisting of group 1 to 14 atoms in the periodic table, halogen atoms, inorganic acids and organic acids. A compound consisting of at least one anion selected from the group consisting of, and more preferably a cation containing at least one atom selected from the group consisting of group 2-14 atoms of the periodic table and Cl, Br, I. , F, PO ₄ , SO ₄ , NO ₃ , CO ₃ , C ₂ O ₄ , ClO ₄ , OOCCH ₃ , CH ₃ COCHCOCH ₃ , OCl ₂ , O (NO ₃ ) ₂ , O (ClO ₄ ) ₂ , O ( A compound consisting of at least one anion selected from the group consisting of SO ₄ ), OH, O ₂ Cl ₂ , OCl ₃ , OOCH, OOCCH ₂ CH ₃ , C ₂ H ₄ O ₄ and C ₅ H ₅ O _7. is there.

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

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

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

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

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

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

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

The method for heat-treating the adsorbed water and the interlayer water of the ion-exchangeable layered silicate is not particularly limited, but it is necessary to select conditions so that the interlayer water does not remain and structural destruction does not occur. The heating time is 0.5 hours or more, preferably 1 hour or more. At that time, when the water content of the catalyst component (B) after removal was 0% by weight when dehydrated for 2 hours under the conditions of a temperature of 200 ° C. and a pressure of 1 mmHg (133 Pa), the water content was 3% by weight. % Or less, preferably 1% by weight or less.

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

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

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

(3) Catalyst component (C)
The catalyst component (C) is an organoaluminum compound. As the organoaluminum compound used as the catalyst component (C), a compound represented by the general formula: (AlR ³¹ _q Z _3-q ) _p is suitable.
Needless to say, in the present invention, the compounds represented by this formula can be used alone, in combination of a plurality of types, or in combination. In this formula, R ³¹ represents a hydrocarbon group having 1 to 20 carbon atoms, and Z represents a halogen, hydrogen, alkoxy group, or amino group. q represents an integer of 1 to 3 and p represents an integer of 1 to 2. As R ³¹ , an alkyl group is preferable, and Z is chlorine when it is a halogen, an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and 1 to 8 carbon atoms when it is an amino group. An amino group of 8 is preferred.

Specific examples of the organic aluminum compound include trimethylaluminum, triethylaluminum, trinormalpropylaluminum, trinormalbutylaluminum, triisobutylaluminum, trinormalhexylaluminum, trinormaloctylaluminum, trinormaldecylaluminum, diethylaluminum chloride, diethylaluminum. Examples thereof include sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, diisobutylaluminum chloride and the like.
Of these, trialkylaluminum with p = 1, q = 3 and dialkylaluminum hydride with p = 1, q = 2 are preferred. More preferably, it is trialkylaluminum in which R ³¹ has 1 to 8 carbon atoms.

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

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

The ratio of the component [A-1] (compound represented by the general formula (a1)) and the component [A-2] (compound represented by the general formula (a2)) used in the present invention is propylene-based. The molar ratio of the transition metal of [A-1] to the total amount of each component [A-1] and [A-2] is preferably 0.30 or more as long as it satisfies the above-mentioned characteristics of the polymer. , 0.99 or less.
By changing this ratio, it is possible to adjust the balance between melt properties and catalytic activity. That is, a low molecular weight terminal vinyl macromer is produced from the component [A-1], and a high molecular weight compound partially copolymerized with the macromer is produced from the component [A-2]. Therefore, by changing the ratio of the component [A-1], the average molecular weight, the molecular weight distribution, the bias of the molecular weight distribution toward the high molecular weight side, the very high molecular weight component, the branching (amount, length, Distribution) can be controlled, thereby controlling the melt properties such as strain hardening degree, melt tension, and melt ductility.

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

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

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

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

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

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

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

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

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

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

8. Other properties of polypropylene resin (X) having a long-chain branched structure As a further additional feature of the polypropylene resin (X) having a long-chain branched structure used in the present invention produced by the above method, the strain rate is 0. The strain hardening degree (λmax (0.1)) in the measurement of the extensional viscosity in 1s ^-1 is preferably 6.0 or more.
The degree of strain hardening (λmax (0.1)) is an index showing the strength at the time of melting, and when this value is large, there is an effect that the melting tension is improved. As a result, the closed cell ratio can be increased when foam molding is performed. When the strain hardening degree is preferably 6.0 or more, the closed cell property can be maintained higher, and more preferably 8.0 or more.

Details of the calculation method of λmax (0.1) will be described below.
-Λmax (0.1) calculation method The extensional viscosity when the temperature is 180 ° C. and the strain rate = 0.1s ^-1 , is the time t (seconds) on the horizontal axis and the extensional viscosity η _E (Pa · seconds) on the vertical axis. Plot with a log-log graph. On the log-log graph, the viscosity immediately before strain curing is approximated by a straight line.
Specifically, the slope at each time when the elongation viscosity is plotted against time is first obtained, but in that case, considering that the measurement data of the elongation viscosity is discrete, various averaging methods are used. To use. For example, there is a method of obtaining the slopes of adjacent data and taking a moving average of several surrounding points.
The elongation viscosity becomes a simple increasing function in the region of low strain rate, gradually approaches a constant value, and matches the Truton viscosity after a sufficient time without strain hardening, but is common in the case of strain hardening. From about 1 strain amount (= strain rate x time), the elongation viscosity begins to increase with time. That is, the slope tends to decrease with time in the low strain region, but tends to increase from about 1 strain amount, and there is an inflection point on the curve when the elongation viscosity is plotted against time. .. Therefore, in the range of the strain amount of about 0.1 to 2.5, find the point where the slope of each time obtained above takes the minimum value, draw a tangent line at that point, and draw a straight line with the strain amount of 4.0. Extrapolate until The maximum value (ηmax) of the extensional viscosity η _E until the strain amount reaches 4.0 is obtained, and the viscosity on the approximate straight line up to that time is defined as ηlin. ηmax / ηlin is defined as λmax (0.1).

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

II. Propylene block copolymer (Y)
The propylene-based block copolymer (Y), which is a component constituting the polypropylene-based resin composition used in the present invention, is a propylene (co) polymer (Y-1) (hereinafter referred to as “Y-1)” produced by conventionally known sequential polymerization. A propylene-based block copolymer (Y), which is a multistage polymer composed of "(Y-1)") and a propylene-ethylene copolymer (Y-2) (hereinafter, also referred to as "(Y-2)"). Is used.
The term block copolymer used here is a common name for a propylene-based resin composition obtained by performing multi-step polymerization by a sequential polymerization method, which is commonly used by those skilled in the art, and at each step. It is different from so-called (real) block copolymers or graft copolymers in which polymerized components are bonded to each other by chemical bonding. Since the components produced in each step of multi-step polymerization are not chemically bonded, in general, crystalline separation is performed by utilizing the difference in crystallinity, molecular weight, solubility in a solvent, etc. of each component. It is possible to separate each of the components produced in each step by a method such as molecular weight separation or solubility separation.
Further, in the block copolymer (Y) produced by the conventionally known sequential polymerization method, the existence of a long-chain branched structure due to a chemical bond such as the polypropylene resin (X) is not recognized with analyzable accuracy.

The propylene-based block copolymer (Y) may be produced using any catalyst such as a conventionally known Ziegler-Natta catalyst or a metallocene catalyst, and the production method may be a conventionally known slurry polymerization method or bulk. Various combinations such as a polymerization method and a gas phase polymerization method can be used.
Here, the Ziegler-Natta catalyst is described in, for example, "Polypropylene Handbook" by Edward P. Moore Jr. It is a catalyst system as outlined in Section 2.3.1 (pages 20-57) of the Industrial Research Council (1998), edited and supervised by Tetsuo Yasuda and Nobu Sakuma. For example, titanium trichloride and halogen. Titanium trichloride catalyst made of organoaluminum, solid catalyst component containing magnesium chloride, titanium halide, and electron donating compound as essential, magnesium-supporting catalyst made of organoaluminum and organosilicon compound, and solid catalyst component It refers to a catalyst in which an organoaluminum compound component is combined with an organosilicon-treated solid catalyst component formed by contacting an organoaluminum and an organosilicon compound. Further, the metallocene catalyst has already been described in detail in the above-mentioned "Method for producing polypropylene resin (X)". Among the above examples, those using the component [A-2] as the catalyst component (A) are preferably used for the production of the propylene-based block copolymer (Y).

Preferred catalysts include, for example, a titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and further treating with various electron donors and electron acceptors, an organoaluminum compound, and an aromatic carboxylic acid ester. (Refer to JP-A-56-100806, JP-A-56-120712, JP-A-58-104907), titanium halide, titanium tetrachloride, and various electron donors. (Refer to JP-A-57-63310, JP-A-63-43915, and JP-A-63-83116) and the like can be exemplified.

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

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

2. 2. Characteristic (Y-ii): MFR
The range of MFR of the propylene-based block copolymer (Y) used in the present invention is in the range of 0.1 to 200 g / 10 minutes, preferably 0.2 to 190 g / 10 minutes, and more preferably 0.5. It is in the range of ~ 180 g / 10 minutes, particularly preferably 2.1 to 170 g / 10 minutes.
This is a normal range as the range of MFR of resins used for various moldings, and when it is 0.1 g / 10 minutes or more, the load of the extruder becomes excessive or the resin is fluidly unstable. On the other hand, in the case of 200 g / 10 minutes or less, problems such as a large neck-in during extrusion molding and difficulty in taking out the sheet are unlikely to occur.
The method for measuring MFR is the same as the method for measuring polypropylene resin (X) described above.

3. 3. Characteristics (Y-iii): Melting peak temperature The melting peak temperature of the propylene-based block copolymer (Y) used in the present invention needs to exceed 155 ° C. from the viewpoint of maintaining the heat resistance of the sheet. It is preferable that the temperature is 157 ° C. or higher. The upper limit of the melting peak temperature does not need to be particularly limited, but it is practically difficult to produce a product having a melting peak temperature exceeding 170 ° C.
The melting peak temperature is raised again by raising the temperature to 200 ° C and erasing the heat history using differential operating calorimetry (DSC), then lowering the temperature to 40 ° C at a temperature lowering rate of 10 ° C / min. It is the temperature of the top of the heat absorption peak when measured at a temperature rate of 10 ° C./min.

4. Characteristics (Y-iv): Ethylene content in the propylene-ethylene copolymer (Y-2) In the present invention, the ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 60% by weight. (However, the total weight of the monomers constituting the propylene-ethylene copolymer (Y-2) is 100% by weight). The preferable range of the ethylene content in the propylene-ethylene copolymer (Y-2) is 11 to 38% by weight, more preferably 16 to 36% by weight, still more preferably 18 to 35% by weight.
When an ethylene content in the above range is used, the dispersed state of (Y-2) in the polypropylene-based resin composition becomes good, and the foaming suitability is excellent.

5. Characteristics (Yv): Intrinsic viscosity of propylene-ethylene copolymer (Y-2) As a result of many experimental studies, the present inventors have found that the propylene-based block copolymer (Y) to be blended in the polypropylene resin composition. ), The intrinsic viscosity value of the propylene-ethylene copolymer (Y-2) measured using 135 ° C. decalin as a solvent needs to be 5.3 dl / g or more, preferably 6.0 dl / g. It has been found that the content is g or more, more preferably 7.0 dl / g or more, and most preferably 7.5 dl / g or more.

When the intrinsic viscosity value is 5.3 dl / g or more, the melt tension is high and the foaming suitability is good.
The upper limit does not need to be specified, but if it is too high, it causes gel generation. Therefore, it is 25.0 dl / g or less, preferably 20.0 dl / g or less, and more preferably 18.0 dl / g or less. Most preferably, it is 16.0 dl / g or less.
The intrinsic viscosity here is a value measured using a Ubbelohde type capillary viscometer at a temperature of 135 ° C. and using decalin as a solvent. In order to obtain the intrinsic viscosity of (Y-2), the component (Y-2) is recovered as a 25 ° C. paraxylene-soluble component by using the same method as described in CXS described above, and the intrinsic viscosity of the component is measured. Assumed to be performed. However, if the ethylene content of the component (Y-2) is less than 15% by weight, it becomes difficult to sufficiently separate the component (Y-2) depending on the CXS method. In such a case, a small amount of the (Y-1) component after the completion of production of the propylene (co) polymer (Y-1) produced in the step-growth polymerization in the middle of the step-growth polymerization is extracted to be intrinsic. The viscosity is measured, and the intrinsic viscosity of the whole (Y) after the completion of sequential polymerization is measured and calculated by the following formula.
Intrinsic viscosity of (Y-2) component = [Intrinsic viscosity of (Y) as a whole-{Intrinsic viscosity of (Y-1) component x Weight fraction of (Y-1) component / 100}] / {(Y-2) ) Component weight fraction / 100}

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

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

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

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

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

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

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

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

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

However, in the analysis method using the combination of the cross fractionation method and the FT-IR method described above, the ethylene content of (Y-2) was less than 15% by weight, and there was no significant difference in crystallinity from (Y-1), and the temperature. Accurate analysis becomes difficult when the separation by the method cannot be sufficiently performed. In such a case, the (Y-1) component of the propylene (co) polymer (Y-1) produced in the step-growth polymerization in the middle of the step-growth polymerization after the production is completed is extracted and its molecular weight. (When copolymerizing a comonomer, the comonomer content is also measured), and further, the amount ratio of the (Y-1) component and the (Y-2) component is determined by calculation by the material balance, and further, It is preferable to determine the comonomer content of the component (Y-2) by measuring the comonomer content of the entire component (Y) at the end of the step-growth polymerization and using the following simple addition rule of weight. When ethylene is used as the comonomer, the ethylene content of (Y-2) shall be determined by the following formula.
Ethylene content of component (Y-2) = [(Y) total ethylene content-{(Y-1) component ethylene content x (Y-1) component weight fraction / 100}] / {(Y-2) ) Component weight fraction / 100}

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

6. Characteristics: Blending amount of propylene-based block copolymer (Y) The blending amount of propylene-based block copolymer (Y) is 2.5 to 67.5% by weight, preferably 10.0 to 60.0% by weight. It is more preferably 15.0 to 55.0% by weight, still more preferably 17.5 to 52.5% by weight (however, the total of (X), (Y) and (Z) is 100% by weight). .. When the blending amount of the propylene-based block copolymer (Y) is within this range, shear heat generation and take-back are performed even at a high foaming ratio that is formed at high speed by the T-die method and exceeds 3.0 times. The load applied to the sheet can be reduced by the tension, and a foamed sheet having excellent air bubble independence and denseness and high appearance can be obtained. Further, when the compounding amount is 67.5% by weight or less, the fluidity is sufficient, there is no problem that the load of the extruder is too high for various moldings, and the amount is 2.5% by weight or more. , The melt tension becomes sufficient, and the properties as a high melt tension material are excellent, which makes it suitable for foam molding.

III. Propylene-α-olefin random copolymer (Z)
The propylene-α-olefin random copolymer (Z) is produced by using a conventionally known Ziegler-Natta catalyst, and the production method includes a conventionally known slurry polymerization method, bulk polymerization method, gas phase polymerization method and the like. Various combinations can be used.
Here, the Ziegler-Natta catalyst is described, for example, in the "Polypropylene Handbook" Edward P. Moore Jr. It is a catalyst system as outlined in Section 2.3.1 (pages 20-57) of the Industrial Research Council (1998), edited and supervised by Tetsuo Yasuda and Nobu Sakuma. For example, titanium trichloride and halogen. Titanium trichloride catalyst made of organoaluminum, solid catalyst component containing magnesium chloride, titanium halide, and electron donating compound as essential, magnesium-supporting catalyst made of organoaluminum and organosilicon compound, and solid catalyst component It refers to a catalyst in which an organoaluminum compound component is combined with an organosilicon-treated solid catalyst component formed by contacting an organoaluminum and an organosilicon compound.
Preferred catalysts include, for example, a titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and further treating it with various electron donors and electron acceptors, an organoaluminum compound, and an aromatic carboxylic acid ester. (Refer to JP-A-56-100806, JP-A-56-120712, JP-A-58-104907), titanium halide, titanium tetrachloride, and various electron donors. (Refer to JP-A-57-63310, JP-A-63-43915, and JP-A-63-83116) and the like can be exemplified.

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

As a result of many experimental studies, the present inventors have found that the propylene-α-olefin random copolymer (Z) blended in the polypropylene resin composition contains a PP filler layer particularly when it has the following characteristics. It has been found that a polypropylene-based foam having a uniform and fine foam cell and having a good appearance of a molded product can be obtained even if the foam layer becomes a multilayer foam sheet having a high foaming ratio of 3.0 times or more. It will be described in detail below.

1. 1. Property (Z-i): Polymerized with Ziegler-Natta catalyst The propylene-α-olefin random copolymer (Z) used in the present invention needs to be polymerized with a Ziegler-Natta catalyst. The propylene-α-olefin random copolymer polymerized with the Ziegler-Natta catalyst is superior in plant productivity and has a wide molecular weight distribution as compared with that polymerized with the metallocene catalyst, so that it melts in the foam molding machine. It has excellent fluidity underneath and is also excellent in foam sheet productivity.

2. 2. Characteristic (Z-ii): The melting peak temperature measured by DSC is 157 ° C. or less. The melting peak temperature of the propylene-α-olefin random copolymer (Z) used in the present invention is the melting peak temperature at the time of foam molding. In order to improve the spreadability of the resin, the temperature needs to be 157 ° C or lower, preferably 156 ° C or lower, more preferably 155 ° C or lower, particularly preferably 154 ° C or lower, and most preferably 153 ° C or lower. Is. The melting peak temperature is raised again by raising the temperature to 200 ° C and erasing the heat history using differential operating calorimetry (DSC), then lowering the temperature to 40 ° C at a temperature lowering rate of 10 ° C / min. It is the temperature of the top of the heat absorption peak when measured at a temperature rate of 10 ° C./min.
When the melting peak temperature is 157 ° C. or lower, the effect of maintaining the independence of bubbles is exhibited. The lower limit of the melting peak temperature is not particularly specified, but 120 ° C. is preferable from the viewpoint of stickiness as a molded product and heat-resistant deformability.

3. 3. Characteristics (Z-iii): Melt flow rate The melt flow rate (MFR) of the propylene-α-olefin random copolymer (Z) needs to be 21.0 g / 10 minutes or more, preferably 21.0 g / g. It is in the range of 10 minutes to 100.0 g / 10 minutes, more preferably 22.0 to 80.0 g / 10 minutes, further preferably 22.5 to 70.0 g / 10 minutes, and even more preferably 23.0 to 23.0 to 10 minutes. It is 60.0 g / 10 minutes, most preferably 26.0 to 55.0 g / 10 minutes. When the MFR of the propylene-α-olefin random copolymer (Z) is within this range, a polypropylene-based foam having uniform and fine foam cells, improved ductility, and a good appearance of the molded product can be obtained. .. Further, when the melt flow rate is 21.0 g / 10 minutes or more, orientation-induced crystallization is suppressed even under high shear during extrusion foam molding, and it is difficult to form a locally solidified portion that causes poor spread, which is good. A molded product having excellent foaming characteristics and excellent appearance can be obtained. Further, when the melt flow rate of the propylene-α-olefin random copolymer (Z) is 100.0 g / 10 minutes or less, there is no problem that the viscosity is too low, and the occurrence of foaming can be prevented. ..
The method for measuring MFR is the same as the method for measuring polypropylene resin (X) described above.

4. Characteristics: Blending amount of propylene-α-olefin random copolymer (Z) The blending amount of the propylene-α-olefin random copolymer used in the present invention is 10 to 65% by weight, preferably 25 to 65% by weight. More preferably 25 to 60% by weight, even more preferably 25 to 55% by weight, even more preferably 25 to 50% by weight (however, the total of (X), (Y) and (Z) is 100% by weight. is there).
When the blending amount of the propylene-α-olefin random copolymer (Z) is within this range, even if the PP filler layer is contained and the foamed layer has a high foaming ratio of 3.0 times or more, the above-mentioned As described above, the effect of making it difficult to form a locally solidified portion that causes poor spread can be obtained, and a foamed sheet having good foaming characteristics and a high appearance can be obtained. When the blending amount is 65% by weight or less, the PP filler layer is less likely to cause foam rupture and cause foaming failure even when cooling is delayed. Further, when the compounding amount is 65% by weight or less, the rigidity of the polypropylene-based resin composition and the melting peak temperature do not decrease too much, and the molded product is not deformed or melted when used at a high temperature.

5. Characteristics: α-olefin content As the α-olefin of the propylene-α-olefin random copolymer (Z), α-olefins having a carbon number of up to about 10 excluding 3 such as ethylene, 1-butene and 1-hexene can be used. It can be selected, but ethylene is preferable.
The α-olefin content in the propylene-α-olefin random copolymer (Z) is preferably 0.5 to 5.0% by weight, more preferably 0.8 to 4.5% by weight, and further. It is preferably 0.9 to 4.0% by weight. When the α-olefin content is within this range, the PP filler layer is particularly contained, and even if the foamed layer has a high foaming ratio of 3.0 times or more, it has uniform and fine foamed cells and has ductility. A polypropylene-based foam that is improved and has a good appearance of the molded product can be obtained. Further, when the amount of α-olefin is 0.5% by weight or more, the spreadability as a propylene-α-olefin random copolymer (Z) is excellent, and the amount of α-olefin is 5.0% by weight or less. , Propylene-α-olefin random copolymer (Z) has improved rigidity and melting peak temperature, and does not deform or melt as a molded product when used at high temperatures.

IV. Constituents, preparation methods, and uses of polypropylene-based resin compositions 1. Components of Polypropylene Resin Composition In the present invention, the polypropylene resin composition comprises the above-mentioned polypropylene resin (X), propylene block copolymer (Y) and propylene-α-olefin random copolymer (Z). A polypropylene-based resin composition containing a foaming agent and further containing a foaming agent is referred to as a polypropylene-based resin composition for foam molding.
The constituent components of the polypropylene-based resin composition suitable for foam molding will be described in detail below.

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

When obtaining a polypropylene-based foam made from a physical foaming agent, a bubble adjusting agent can be used, if necessary. Examples of the bubble adjusting agent include inorganic degradable foaming agents such as ammonium carbonate, baking soda, ammonium bicarbonate and ammonium nitrite, azo compounds such as azodicarboxylic amide, azobisisobutyronitrile and diazoaminobenzene, and N, N'-. Dinitrosopentan methylenetetramine and nitroso compounds such as N, N'-dimethyl-N, N'-dinitrosoterephthalamide, benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p, p'-oxybisbenzenesulfonyl semicarbadide, p- Degradable foaming agents such as toluenesulfonyl semicarbadide, trihydrazinotriazine, bariumazodicarboxylate, inorganic powders such as talc and silica, acidic salts such as polyvalent carboxylic acid, reaction of polyvalent carboxylic acid with sodium carbonate or sodium bicarbonate. Examples thereof include a mixture, and these can be used alone or in combination.

When a polypropylene-based foam is obtained from a degradable foaming agent (chemical foaming agent), the degradable foaming agent (chemical foaming agent) is, for example, a mixture of sodium bicarbonate and an organic acid such as citric acid, azodicarboxylicamide. , Azo-based foaming agents such as barium azodicarboxylic acid, nitroso-based foaming agents such as N, N'-dinitrosopentamethylenetetramine, N, N'-dimethyl-N, N'-dinitrosopentamamide, p, p' Examples thereof include sulfohydrazide-based foaming agents such as -oxybisbenzenesulfonylhydrazide and p-toluenesulfonyl semicarbazide, and trihydrazinotriazine.
The blending amount of the foaming agent is preferably in the range of 0.05 to 6.0 parts by weight, more preferably 0, based on 100 parts by weight of the total of the components (X), (Y), and (Z). It is 05 to 3.0 parts by weight, more preferably 0.5 to 2.5 parts by weight, and particularly preferably 1.0 to 2.0 parts by weight.
When the blending amount of the foaming agent is 6.0 parts by weight or less, hyperfoaming does not occur and uniform miniaturization of the foaming cell becomes easy, while when the blending amount of the foaming agent is 0.05 parts by weight or more, The amount of gas generated is large, which is preferable.
When using the bubble adjusting agent, the blending amount of the bubble adjusting agent is 0.01 to 0.01 to 100 parts by weight in total of the components (X), (Y) and (Z). It is preferably in the range of 5 parts by weight. The term "pure content" as used herein means that when a masterbatch or the like containing a certain amount of the bubble adjusting agent is used, the amount is only the bubble adjusting agent.

(2) Other Blending Agents In the polypropylene-based resin composition for foam molding used in the present invention, the components (X), (Y), and (Z), and a foaming agent, and if necessary, bubble adjustment. In addition to the agents, various additives such as other polymers, antioxidants, neutralizers, light stabilizers, ultraviolet absorbers, inorganic fillers, lubricants, antistatic agents, and metal deactivators are used as objects of the present invention. Can be blended within a range that does not impair.
Examples of other polymers include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene-based resins other than those described above, propylene-α-olefin copolymers (α-olefins have 4 or more carbon atoms), and poly. Polyolefins such as -4-methyl-1-pentene, olefin elastomers such as ethylene-propylene elastomers, or other monomers copolymerizable with these, such as vinyl acetate, vinyl chloride, (meth) acrylic acid, (meth). ) Copolymers such as acrylic ester and mixtures thereof can be mentioned.

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

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

3. 3. Applications The polypropylene-based resin composition used in the present invention has various molding methods and applications that require high melt tension, such as injection molding (body), extrusion molding (body), bead foam molding (body), and extrusion foam molding (body). It can be suitably used for injection foam molding (body), blow molding (body), injection blow molding (body), foam blow molding (body), deep drawing molding (body), thermal molding (body), etc. However, it can be suitably used in the field of foam molding, in which the balance between melt tension and extensibility is particularly important.

4. Polypropylene Resin Multilayer Foam Sheet The polypropylene resin multilayer foam sheet according to the present invention comprises a foam layer made of the polypropylene resin composition for foam molding described above, a PP filler layer containing an inorganic filler, and a thermoplastic resin composition. It has a surface layer.
In the polypropylene-based resin foamed sheet according to the present invention, the average cell diameter of the foamed layer is preferably 500 μm or less, more preferably 400 μm or less, still more preferably 300 μm or less. When the average cell diameter is 500 μm or less, both the polypropylene-based foamed sheet and the thermoformed body obtained by further thermoforming the sheet do not cause appearance defects such as perforation, which is preferable.
In the polypropylene-based resin multilayer foamed sheet according to the present invention, the closed cell ratio of the foamed layer is preferably 17% or more, more preferably 18% or more, further preferably 20% or more, and particularly preferably 25% or more. .. When the closed cell ratio is 25% or more, the foam cells in the foam sheet are less likely to be exposed on the surface of the container during thermoforming, and the appearance of the container is improved, which is preferable.
The thickness of the polypropylene-based resin multilayer foamed sheet according to the present invention is not particularly limited, but is preferably 0.3 mm to 10 mm. It is more preferably 0.5 mm to 5 mm, and most preferably 0.5 mm to 4 mm. In particular, when molding by the T-die method, if the foam sheet thickness is 0.3 mm or more, there is no problem that the sheet is strongly spread during molding and the sheet is crushed, foaming defects can be prevented, and even if it is 10 mm or less. For example, there is no problem such as wrinkles on the sheet, and poor appearance can be prevented.
Further, the foaming ratio of the foamed layer of the polypropylene-based multilayer resin foamed sheet according to the present invention is not particularly limited, but generally, the higher the foaming ratio, the better the performance as a foam such as weight reduction and heat insulation. For example, 2.1 times or more, preferably 2.3 times or more, more preferably 3.0 times or more, particularly preferably 3.3 times or more, and most preferably 3.5 times or more. In particular, the polypropylene-based resin foam sheet according to the present invention contains a PP filler layer containing an inorganic filler and a polypropylene-based resin composition, and is uniform even when the foamed layer has a high foaming ratio of 3.0 times or more. A fine foam cell can be achieved.

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

Further, in order to obtain a polypropylene-based resin multilayer foamed sheet, a method of coextruding a foamed layer made of a polypropylene-based resin composition and a non-foamed layer made of a thermoplastic resin composition can be used. The polypropylene-based multilayer resin foam sheet according to the present invention includes a PP filler layer containing an inorganic filler and a surface layer made of a thermoplastic resin composition, and the PP filler layer and the surface layer are usually non-foamed layers. ..
The polypropylene-based resin multilayer foam sheet can be produced by a known coextrusion method, extrusion laminating method, or the like using a feed block using a plurality of extruders, a multi-die, or the like, but the coextrusion method is preferable.

The non-foamed layer used for the polypropylene-based resin multilayer foamed sheet may be provided on any surface of the foamed layer, and has a structure (sandwich structure) in which the foamed layer is present between the two non-foamed layers. You can also do it. The polypropylene-based resin multilayer foam sheet according to the present invention includes a three-layer structure of a foam layer / PP filler layer / surface layer, a five-layer structure of a surface layer / PP filler layer / foam layer / PP filler layer / surface layer, and the like. However, a three-kind five-layer structure of a surface layer / PP filler layer / foam layer / PP filler layer / surface layer is preferable.
The polypropylene-based resin multilayer foamed sheet provided with the PP filler layer has excellent strength, and is preferably a thermoplastic resin composition containing no PP filler layer on the outside of the foamed layer and no inorganic filler on the outside. By providing the surface layer made of the polypropylene-based resin composition, the surface smoothness and appearance are also excellent. Furthermore, by using a functional thermoplastic resin for the non-foamed layer, it is possible to easily combine the polypropylene-based resin multilayer foamed sheet with additional functions such as antibacterial property, soft feeling, and scratch resistance. ,preferable.

In the polypropylene-based resin multilayer foamed sheet according to the present invention, the PP filler layer is a layer made of a polypropylene-based resin composition containing an inorganic filler, and the surface layer is made of a thermoplastic resin composition, preferably a polypropylene-based resin composition. It is a layer. As described above, the PP filler layer and the surface layer are usually non-foaming layers.

Examples of the thermoplastic resin constituting the thermoplastic resin composition used for the non-foamed layer include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, component (X), as long as the effects of the present invention are not impaired. Polypropylene or propylene-α-olefin copolymer which may be the same as each component of (Y) and (Z), polyolefin such as poly-4-methyl-1-pentene, olefin elastomer such as ethylene-propylene elastomer , Or other monomer copolymerizable with these, for example, copolymers such as vinyl acetate, vinyl chloride, (meth) acrylic acid, (meth) acrylic acid ester, and mixtures thereof can be selected. ..
Among these, polypropylene-based resin compositions containing polypropylene, propylene-α-olefin copolymers, and the like are preferable from the viewpoints of recyclability, adhesiveness, heat resistance, oil resistance, rigidity, and the like. As the propylene-α-olefin copolymer, so-called impact-resistant polypropylene obtained by multi-step polymerization of a propylene (co) polymer and an ethylene-propylene random copolymer using a plurality of or single-tank polymerization tanks. Alternatively, it includes a multi-stage polymer commonly called a propylene block copolymer.

Further, as the polypropylene-based resin composition used for the PP filler layer, it is desirable to add 50 parts by weight or less of the inorganic filler to 100 parts by weight of the polypropylene-based resin contained in the resin composition. When the blending amount of the inorganic filler is 50 parts by weight or less, there is no problem such as generation of shavings at the die outlet, and deterioration of the appearance of the sheet can be prevented.
The inorganic filler is not particularly limited, and examples thereof include talc, calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, and magnesium silicate.

Further, the total thickness of the non-foamed layers in the polypropylene-based resin multilayer foamed sheet according to the present invention is 1 to 50%, more preferably 5 to 20% of the total thickness of the obtained polypropylene-based resin multilayer foamed sheet. It is desirable to form in. When the thickness of the non-foamed layer is 50% or less, the growth of bubbles in the foamed layer is not hindered.

Further, the polypropylene-based resin multilayer foamed sheet according to the present invention may be subjected to surface treatment such as corona discharge treatment, flame treatment, plasma treatment, etc. on the surface of the foamed sheet for printability and paintability. ..

5. Applications of Polypropylene Resin Foam Sheet and Thermoformed Body The polypropylene resin multi-layer foam sheet according to the present invention and the molded body (thermoformed body) obtained by thermoforming the multilayer foam sheet can obtain uniform and fine foam cells. Due to its excellent appearance, thermoformability, impact resistance, light weight, rigidity, heat resistance, heat insulation, oil resistance, etc., food containers such as trays, plates and cups, automobile door trims, automobile trunk mats and other vehicles It can be suitably used for interior materials, packaging, stationery, building materials, etc.

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

1. 1. Evaluation method (1) Melt flow rate MFR:
Measurements were made in accordance with JIS K7210: 1999 Annex A Table 1, Condition M (230 ° C, 2.16 kg load). The die shape has a diameter of 2.095 mm and a length of 8.000 mm. The unit is g / 10 minutes.
(2) Melt tension MT:
The measurement was performed under the following conditions using a capillograph manufactured by Toyo Seiki Seisakusho Co., Ltd.
・ Capillaries: diameter 2.0 mm, length 40 mm
・ Cylinder diameter: 9.55 mm
・ Cylinder extrusion speed: 20 mm / min ・ Pickup speed: 4.0 m / min ・ Temperature: 230 ° C
If the MT is extremely high, the resin may break at a pick-up speed of 4.0 m / min. In such a case, the pick-up speed is reduced and the tension at the maximum pick-up speed is increased to MT. And. The unit is grams.
(3) Molecular weight distribution Mw / Mn and Mz / Mn:
It was determined by GPC measurement according to the method described above.
(4) 25 ° C. Paraxylene-soluble component amount (CXS):
It was measured by the method described in the specification.
(5) mm fraction:
As described above, the measurement was carried out by the method described in paragraphs [0053] to [0065] of JP-A-2009-275207, using GSX-400 and FT-NMR manufactured by JEOL Ltd.
The unit is%.

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

(11) Foam density:
A test piece is cut out from the polypropylene-based resin multilayer foam sheet (foam) obtained in Examples and Comparative Examples, and the weight (g) of the test piece is divided by the volume (cm ³ ) obtained from the external dimensions of the test piece. I asked. The density of the foam was determined by measuring according to JIS K7222.
(12) Foam layer magnification:
The cross section of the foamed sheet was observed using an optical microscope, and the thicknesses of the surface layer, the PP filler layer, and the foamed layer were measured. From the densities of the multi-layer foam sheet, the surface layer and the PP filler layer, and the thickness of the surface layer, the PP filler layer and the foam layer, the density of the foam layer of the multi-layer foam sheet was calculated according to an "empirical formula called an addition rule of physical properties". The surface layer, the density of the polypropylene resin used in the PP filler layer and foam layer are 0.91 g / cm ^3, the density of PP filler layer used in this embodiment is 1.15 g / cm ^3.
Further, the value obtained by dividing the density of polypropylene resin 0.91 g / cm ³ by the density of the foam layer was taken as the foam layer magnification.
(13) Foam layer closed cell ratio:
A test piece was cut out from the polypropylene-based resin multilayer foamed sheet obtained in Examples and Comparative Examples, and an air pycnometer (manufactured by Tokyo Science Co., Ltd.) was used to foam the multilayer foamed sheet according to the method described in ASTM D2856. The closed cell ratio of the foamed layer was calculated for the layer portion. The surface layer, the density of the polypropylene resin used in the PP filler layer and foam layer are 0.91 g / cm ^3, the density of PP filler layer used in this embodiment is 1.15 g / cm ^3.
(14) Sheet appearance evaluation:
The appearance of the foamed sheet was evaluated based on the following criteria for the polypropylene-based resin multilayer foamed sheets obtained in Examples and Comparative Examples.
◯: The independence of bubbles is high, the surface of the foamed sheet is smooth, and the appearance is beautiful.
Δ: The surface of the foamed sheet is smooth, but the independence of bubbles is low and the appearance is inferior.
X: Wrinkles and fire swelling occur on the sheet, and the appearance is significantly inferior.
(15) Container moldability:
Regarding the container moldability, the container moldability was evaluated as follows using a multipurpose thermoforming machine manufactured by Asano Laboratories Co., Ltd.
From the polypropylene-based resin multilayer foam sheets obtained in Examples and Comparative Examples, a test piece having a size of 530 mm × 530 mm was cut out and fixed to a clamp frame. After heating both sides of the foam sheet with the upper and lower heaters, vacuum pressure air molding was performed using a circular container mold having an inner diameter of 22 cm and a depth of 3.8 cm, and the molded container was visually evaluated according to the following criteria. In addition, when molding the container of each sample, the container was manufactured by changing the heating time and the mold position so that the container could be molded as clean as possible.
◯: No wrinkles or crushes were confirmed in the container after thermoforming, and a good container with less uneven thickness could be molded.
Δ: Slight wrinkles and crushing were confirmed on the container after thermoforming, but the container could be molded.
X: Significant crushing and wrinkles were confirmed in the container after thermoforming, and there were places where air bubbles were exposed on the surface, so a good container could not be molded.

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

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

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

Synthesis of (iii) 2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indene To a 500 ml glass reaction vessel, 6.7 g (82 m1 mol) of 2-methylfuran and 100 ml of DME were added. , Cooled to −70 ° C. in a dry ice-methanol bath. 51 ml (81 mmol) of a 1.59 mol / L n-butyllithium-n-hexane solution was added dropwise thereto, and the mixture was stirred as it was for 3 hours. The mixture was cooled to −70 ° C., and a solution of 20 ml (87 mmol) of triisopropylborate and 50 ml of DME was added dropwise thereto. After the dropping, the mixture was stirred overnight while gradually returning to room temperature.
After adding 50 ml of distilled water to the reaction mixture and hydrolyzing it, 19.8 g (63 mmol) of 2-bromo-4- (4-i-propylphenyl) inden, a solution of 223 g of potassium carbonate and 100 ml of water, was added in this order at 80 ° C. The mixture was heated and reacted for 3 hours while removing low boiling water.
After allowing to cool, the reaction mixture was poured into 300 ml of distilled water, transferred to a separating funnel, extracted 3 times with diisopropyl ether, and the ether layer was washed with saturated brine and dried over sodium sulfate. The sodium sulfate was filtered, the solvent was evaporated under reduced pressure, and the residue was purified on a silica gel column. 19.6 g (19.6 g) of a colorless liquid of 2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) inden. Yield 99%) was obtained.

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

(V) Synthesis of dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl}] hafnium In a 500 ml glass reaction vessel, Add 8.6 g (13 mmol) of dimethylbis (2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl) silane and 300 ml of diethyl ether, and in a dry ice-methanol bath at -70 ° C. Cooled to. To this, 15 ml (25 mmol) of a 1.66 mol / L n-butyllithium-n-hexane solution was added dropwise, and the mixture was stirred for 3 hours. The solvent of the reaction mixture was distilled off under reduced pressure, 400 ml of toluene and 40 ml of diethyl ether were added, and the mixture was cooled to −70 ° C. in a dry ice-methanol bath. To this, 4.0 g (13 mmol) of hafnium tetrachloride was added. Then, the mixture was stirred overnight while gradually returning to room temperature.
The solvent was evaporated under reduced pressure, recrystallized from dichloromethane-hexane, and dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-i-propylphenyl) indenyl. }] 7.6 g (65% yield) of the racemic hafnium was obtained as yellow crystals.
The identification values of the obtained racemic mixture by ¹ H-NMR are described below.
^{1 1} H-NMR (C ₆ D ₆ ) identification result Racemic: δ0.95 (s, 6H), δ1.10 (d, 12H), δ2.08 (s, 6H), δ2.67 (m, 2H) , Δ5.80 (d, 2H), δ6.37 (d, 2H), δ6.74 (dd, 2H), δ7.07 (d, 2H), δ7.13 (d, 4H), δ7.28 ( s, 2H), δ7.30 (d, 2H), δ7.83 (d, 4H).

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

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

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

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

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

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

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

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

<Preparation of prepolymerization catalyst B1>
(1) Preparation of Solid Component B1 An autoclave having a capacity of 10 L equipped with a stirrer was sufficiently replaced with nitrogen, and 2 L of purified toluene was introduced. Here, at room temperature, 200 g of Mg (OEt) ₂ was added, and 1 L of TiCl ₄ was slowly added. The temperature was gradually raised to 90 ° C., and 50 ml of di-n-butyl phthalate was introduced. Then, the temperature was raised to 110 ° C. and a 3 hr reaction was carried out. The reaction mixture was thoroughly washed with purified toluene. Then, purified toluene was introduced to adjust the total liquid volume to 2 L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and a 2 hr reaction was carried out. The reaction mixture was thoroughly washed with purified toluene. Then, purified toluene was introduced to adjust the total liquid volume to 2 L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and a 2 hr reaction was carried out. The reaction mixture was thoroughly washed with purified toluene. Further, using purified n-heptane, toluene was replaced with n-heptane to obtain a slurry of solid component B1. A part of this slurry was sampled and dried. As a result of analysis, the Ti content of the solid component B1 was 2.7 wt%.

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

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

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

(First step: Production of propylene polymer)
Regarding the gas composition of the first polymerization tank, propylene and nitrogen were continuously supplied so that the partial pressure of propylene was 1.8 MPaA and the total pressure of the polymerization tank was 3.0 MPaG. Further, hydrogen as a molecular weight control agent was continuously supplied so as to have a molar ratio of hydrogen / propylene of 0.020. The polymerization temperature was controlled to be 60 ° C. Et ₃ Al is supplied to the first polymerization tank at 4.0 g / h, and the above-mentioned prepolymerization catalyst B1 is added so that the production rate of the propylene polymer in the first polymerization tank is 17.5 kg / h. The propylene homopolymer was produced by continuously supplying the polymer. The powder (propylene polymer) produced in the first polymerization tank was continuously extracted so that the amount of powder held in the polymerization tank was 40 kg, and was continuously transferred to the second polymerization tank. When a part of the powder transferred from the first polymerization tank to the second polymerization tank was sampled and analyzed, the MFR was 20.0 g / 10 minutes. When measuring MFR, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (commodity) was added to the sample propylene polymer. Name: IRGANOX1010, manufactured by BASF Japan Co., Ltd., Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Co., Ltd.), calcium stearate, appropriate amounts (500 wtppm) In order to add (about), these were placed in a plastic bag, and the contents were mixed (dry blended) by shaking the bag up, down, left and right by hand to sufficiently stir the contents, and then the measurement was performed.
Further, MPaG is a gauge pressure based on atmospheric pressure, and has a relationship of XX [MPaG] = XX + 0.10133 [MPaA] with MPaA (absolute pressure) based on vacuum pressure.

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

[Manufacture of propylene-based block copolymer (Y) pellets]
1,3,5-Tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate (1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate with respect to 100 parts by weight of the propylene block copolymer (Y1) obtained in Production Example 3. Product name: Cyanox1790, manufactured by Nippon Cytec Industries Co., Ltd. 0.05 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Co., Ltd.) 0. 10 parts by weight and 0.05 part by weight of calcium stearate were mixed and mixed at room temperature for 3 minutes using a high-speed stirring mixer (Henchel mixer, trade name). Then, it was melt-kneaded and extruded with a twin-screw extruder, passed through a cold water tank, and then the strands were cut with a strand cutter to obtain pellets.
A KZW-25 manufactured by Technobel Co., Ltd. is used for the twin-screw extruder, the screw rotation speed is 300 RPM, and the kneading temperature is 80, 160, 180, 200, 200, 200, 210, 210, 210 ° C. (dice) from the bottom of the hopper. It was set to the exit).
As a result of analyzing the pellets of the obtained propylene-based block copolymer (Y1), the MFR was 1.2 g / 10 minutes, and the propylene-ethylene copolymer (Y-2) in the propylene-based block copolymer (Y) was found. 28.0% by weight, the ethylene content in the propylene-ethylene copolymer (Y-2) is 26.0% by weight, and the melting peak temperature of the propylene-based block copolymer (Y) is 160.0 ° C. The intrinsic viscosity of the propylene-ethylene copolymer (Y-2) was 9.4 dl / g.
The pellet of the propylene-based block copolymer (Y1) is also referred to as the pellet (Y1) of the component (Y).

(3) Propylene-α-olefin random copolymer (Z)
As the propylene-α-olefin random copolymer (Z), a commercially available grade can be used.
(Z1) Novatec PP MG03BF (trade name, manufactured by Japan Polypropylene Corporation), catalyst: Ziegler-Natta catalyst, melting peak temperature: 148 ° C, MFR: 30 g / 10 minutes (Z2) Novatec PP MG03EQ (trade name, Japan Polypropylene) (Manufactured by Co., Ltd.), Catalyst: Ziegler-Natta catalyst, melting peak temperature: 144 ° C, MFR: 30 g / 10 minutes)
(Z3) Novatec PP MG3F (trade name, manufactured by Japan Polypropylene Corporation), catalyst: Ziegler-Natta catalyst, melting peak temperature: 152 ° C, MFR: 8 g / 10 minutes

(4) Propylene homopolymer (H1) Novatec PP MA1B (trade name, manufactured by Japan Polypropylene Corporation), catalyst: Ziegler-Natta catalyst, melting peak temperature: 158 ° C, MFR: 20 g / 10 minutes

(5) Inorganic filler-containing resin composition for PP filler layer (PPF-1) TX1447MBN (trade name, manufactured by Japan Polypropylene Corporation), talc masterbatch

(6) Resin composition for non-foamed layer (PP-3) Novatec PP BC3BRFA (trade name, manufactured by Japan Polypropylene Corporation), MFR: 13 g / 10 minutes)

[Example 1]
Mixture 100 in which the weight ratio of the pellet (X1) of the component (X), the pellet (Y1) of the component (Y), and the pellet (Z1) of the component (Z) is 49:21:30 in order to obtain a foamed layer. A part by weight and 1.25 parts by weight of a chemical foaming agent (trade name: Hydrocerol CF40E-J, manufactured by Clariant Japan Co., Ltd.) as a bubble adjusting agent are uniformly stirred and mixed by a ribbon blender, and physically in the middle of the barrel. It was put into an extruder having a screw diameter of 65 mmΦ having a barrel hole for injecting a foaming agent.
While setting the cylinder set temperature of the extruder to 240 ° C. and the screw rotation speed to 75 rpm to heat and melt the resin to plasticize it and decompose the bubble conditioner, carbon dioxide is added as a physical foaming agent to 100 parts by weight of the mixture. , A polypropylene-based resin composition for foam molding was obtained by press-fitting and kneading at a ratio of 0.48 parts by weight with respect to the resin discharge amount of the foam layer.
The set temperature of the latter stage of the extruder was set to 180 ° C., and the polypropylene-based resin composition for foam molding was cooled.
Further, in order to obtain the PP filler layer, the above-mentioned resin composition PPF-1 for the PP filler layer and the resin composition PP-3 for the non-foaming layer are stirred by a ribbon blender so that the weight ratio is 50:50. The mixture was mixed, charged into an extruder having a screw diameter of 65 mmΦ, heated and melted at 230 ° C., and then cooled by setting the set temperature of the extruder cylinder to 180 ° C.
Further, in order to obtain a surface layer, the resin composition PP-3 for a non-foaming layer is put into an extruder having a screw diameter of 40 mmΦ, heated and melted at 230 ° C., and then cooled by setting the temperature of the extruder cylinder to 200 ° C. did.
The foam layer, PP filler layer and surface layer are composed of 3 types and 5 layers composed of a surface layer / PP filler layer / foam layer / PP filler layer / surface layer from a T die (gap = 0.4 mm) via a feed block. Co-extruded into the atmosphere at a discharge rate of 105 kg / hr to form a multi-layer foam, and while cooling the foam with a cooling roll, it was picked up with a pinch roll to adjust the thickness, and a polypropylene-based resin multi-layer foam with a thickness of 0.71 mm was obtained. I got a sheet.
The obtained multilayer foam sheet has a layer structure of surface layer: PP filler layer: foam layer: PP filler layer: surface layer thickness of 8: 80: 534: 80: 8, and has a foam density of 0.43 g. / cm ^3, the foamed layer closed cell ratio was achieved and good appearance of 54%. The evaluation results of the foam sheet are shown in Table 2.

[Examples 2 to 4]
The pellets of the component (X), the component (Y), and the component (Z) are mixed with the type and weight ratio as shown in Table 2 and 1.25 parts by weight of the chemical foaming agent described in Example 1 as a bubble adjusting agent. A multilayer foamed sheet was obtained in the same manner as described in Example 1. Table 2 shows the evaluation results of the obtained foam sheet.

[Example 5]
First, in order to pellet the powder of the component (Z2), tetrakis [methylene-3- (3,5-gyt-butyl-4-hydroxyphenyl) propionate] methane (trade name:) per 100 parts by weight of the component (Z2). IRGANOX 1010, manufactured by BASF Japan Ltd. 0.10 parts by weight, Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.) 0.10 parts by weight , 0.05 part by weight of calcium stearate, and mixed at room temperature for 3 minutes using a high-speed stirring mixer (Henchel mixer, trade name). Then, it was melt-kneaded and extruded with a twin-screw extruder, passed through a cold water tank, and then the strands were cut with a strand cutter to obtain pellets.
A KZW-25 manufactured by Technobel Co., Ltd. is used for the twin-screw extruder, the screw rotation speed is 300 RPM, and the kneading temperature is 80, 160, 180, 200, 200, 200, 210, 210, 210 ° C. (dice) from the bottom of the hopper. It was set to the exit).
Pellets of the obtained component (Z2) and pellets of the component (X) and the component (Y) in the types and weight ratios as shown in Table 2, and the chemical foaming agent 1 according to Example 1 as a bubble adjusting agent. A multi-layer foamed sheet was prepared by mixing with .25 parts by weight in the same manner as in Example 1. Table 2 shows the evaluation results of the obtained foam sheet.

[Example 6]
The pellets of the component (X), the component (Y), and the component (Z) are mixed with the type and weight ratio as shown in Table 2 and 1.25 parts by weight of the chemical foaming agent described in Example 1 as a bubble adjusting agent. A multilayer foamed sheet was obtained in the same manner as described in Example 5. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 1]
In order to obtain a foamed layer, only the pellets (X1) of the component (X) and the pellets (Y1) of the component (Y) were used at a weight ratio of 70:30, and the layers were formed in the same manner as in Example 1. A foam sheet was obtained. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 2]
In order to obtain a foamed layer, only the pellets (X2) of the component (X) and the pellets (Y1) of the component (Y) were used at a weight ratio of 70:30, and the layers were formed in the same manner as in Example 1. A foam sheet was obtained. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 3]
To obtain a foamed layer, pellets of component (X) (X1), pellets of component (Y) (Y1) and pellets of propylene-α-olefin random copolymer (Z), which is outside the scope of the claims of the present application. A multilayer foamed sheet was obtained in the same manner as described in Example 1 except that (Z3) was used in a weight ratio of 35:15:50. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 4]
In order to obtain a foamed layer, the pellets of the component (X) (X1), the pellets of the component (Y) (Y1), and the pellets of the polypropylene homopolymer (H1), which is outside the scope of the claims of the present application, are weight-ratio 35: A foamed sheet was obtained in the same manner as described in Example 1 except that it was used at 15:50. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 5]
In order to obtain a foamed layer, the pellet (X1) of the component (X), the pellet (Y1) of the component (Y), and the pellet (Z1) of the component (Z) are weight ratio 17 which is outside the scope of the claims of the present application. A foamed sheet was obtained in the same manner as described in Example 1 except that it was used in 5.5: 7.5: 75. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Comparative Example 6]
In order to obtain a foamed layer, the pellet (X2) of the component (X), the pellet (Y1) of the component (Y), and the pellet (Z1) of the component (Z) are weight ratio 17 which is outside the scope of the claims of the present application. A foamed sheet was obtained in the same manner as described in Example 1 except that it was used in 5.5: 7.5: 75. The foamed sheet had a low closed cell ratio and was inferior in the appearance of the sheet. Table 2 shows the evaluation results of the obtained foam sheet.

[Examples 7 to 10]
In the same manner as described in Example 1, a multilayer foam sheet having the thickness of each layer, the foam density, the foam layer magnification and the closed cell ratio shown in Table 3 was obtained. Here, the types and weight ratios of the component (X), the component (Y) and the component (Z), and the PP filler layer composition and the surface layer composition were changed to those shown in Table 3. The evaluation results of the obtained foam sheet are shown in Table 3.

The polypropylene-based resin multilayer foamed sheet of the present invention and the thermoformed body using the foamed sheet can obtain uniform and fine foamed cells, and have appearance, thermoformability, impact resistance, light weight, rigidity, heat resistance, and heat insulating properties. Due to its excellent oil resistance, it can be suitably used for food containers such as trays, plates and cups, vehicle interior materials such as automobile door trims and automobile trunk mats, packaging, stationery, building materials, etc., and has extremely high industrial value. high.

Claims (5)

A foamed layer made of a polypropylene-based resin composition for foam molding containing 0.05 to 6.0 parts by weight of a foaming agent with respect to 100 parts by weight of the polypropylene-based resin composition, a PP filler layer containing an inorganic filler, and thermoplasticity. A polypropylene-based resin multilayer foamed sheet provided with a surface layer made of a resin composition.
The polypropylene-based resin composition
67.5 to 2.5% by weight of polypropylene resin (X) having the following characteristics (X-i) to (X-iv) and having a long-chain branched structure.
Propine, which has the following properties (Yi) to (Yv) and is a multi-stage polymer composed of a propylene (co) copolymer (Y-1) and a propylene-ethylene copolymer (Y-2). 2.5 to 67.5% by weight of the block copolymer (Y), and propylene-α-olefin random copolymer (Z) having the following properties (Z-i) to (Z-iii). 10-65% by weight
A polypropylene-based resin multilayer foamed sheet comprising (however, the total of (X), (Y), and (Z) is 100% by weight).
(X-i) MFR is 0.1 to 30.0 g / 10 minutes.
(X-ii) The molecular weight distribution Mw / Mn by GPC is 3.0 to 10.0, and Mz / Mw is 2.5 to 10.0.
(X-iii) Melt tension (MT) (unit: g) is
log (MT) ≧ -0.9 × log (MFR) +0.7, or MT ≧ 15
To meet any of the above.
(X-iv) The amount of the paraxylene-soluble component (CXS) at 25 ° C. is less than 5.0% by weight based on the total weight of the polypropylene resin (X).
The ratio of (Y-i) (Y-1) to (Y-2) is 50 to 99% by weight for (Y-1) and 1 to 50% by weight for (Y-2) (however, propylene). The total weight of the block copolymer (Y) is 100% by weight).
The MFR of the (Y-ii) propylene block copolymer (Y) is 0.1 to 200.0 g / 10 minutes.
The melting peak temperature of the (Y-iii) propylene-based block copolymer (Y) exceeds 155 ° C.
The ethylene content in the (Y-iv) propylene-ethylene copolymer (Y-2) is 11 to 60% by weight (however, the total weight of the constituent monomers of the propylene-ethylene copolymer (Y-2) is taken. 100% by weight.).
The intrinsic viscosity of the (Yv) propylene-ethylene copolymer (Y-2) in decalin at 135 ° C. is 5.3 dl / g or more.
(Z-i) Polymerized with a Ziegler-Natta catalyst.
(Z-ii) The melting peak temperature measured by DSC is 157 ° C or lower.
(Z-iii) MFR is 21.0 g / 10 minutes or more. The polypropylene-based resin multilayer foamed sheet according to claim 1, wherein the polypropylene resin (X) has the following characteristics (Xv).
(X-v): branching index absolute molecular weight Mabs are in 1,000,000 g ^'is less than 0.30 or more 0.95. The polypropylene-based resin multilayer foamed sheet according to claim 2, wherein the polypropylene resin (X) has the following characteristics (X-vi).
(X-vi): ¹³ The mm fraction of 3 chains of propylene units by C-NMR is 95% or more. A molded product obtained by thermoforming the multilayer foam sheet according to any one of claims 1 to 3. A molded product obtained by molding the multilayer foam sheet according to any one of claims 1 to 3, wherein a foam layer made of the polypropylene-based resin composition for foam molding is formed by an injection molding method, a heat molding method, or extrusion molding. A molded product obtained by molding by any of a molding method, a blow molding method, or a bead foam molding method.