JP5171727B2 - Polypropylene-based injection-foamed molded article and method for producing the same - Google Patents

Description

  The present invention relates to a polypropylene-based injection-foamed molded article, in particular, a polypropylene-based foam-molded article having good moldability, excellent foam uniformity and surface appearance, and capable of significantly reducing weight at a high foaming ratio, and a method for producing the same. About.

Conventionally, polypropylene resin has good physical properties and moldability, and its use range is rapidly expanding as an environmentally friendly material. In particular, for automobile parts and the like, a lightweight and excellent polypropylene resin product is provided, and one of such products is an injection foam molded product of a polypropylene resin.
So far, in the injection molding of polypropylene resin, so-called injection foam molding has been performed in which foaming is performed for weight reduction, cost reduction, and prevention of warping and sink marks of the molded body. As a technology for highly foaming polypropylene-based resin, a resin containing a foaming agent is injection-molded in a mold space that is held so that the mold can be opened, and then the mold is opened to expand the space. There is a so-called core back method (moving cavity method) for foaming (for example, Patent Document 1).
Ordinary linear polypropylene resins are crystalline and have low melt tension (melting tension), and bubbles are easily destroyed. As a result, appearance defects called silver streaks (or swirl marks) are likely to occur on the surface of the molded body, and voids are likely to be generated inside, making it difficult to increase the expansion ratio. In addition, since the bubbles were non-uniform and large, the resulting molded article was not sufficiently rigid. Note that the void means a coarse bubble generated when internal bubbles communicate with each other, and means a bubble whose diameter substantially exceeds 1.5 mm.
As a method for improving foamability, a method of increasing the melt tension of a polypropylene resin by adding a crosslinking agent or a silane graft thermoplastic resin has been proposed (for example, Patent Document 2 and Patent Document 3). However, in this method, although a foamed molded article having a high expansion ratio can be obtained, the viscosity at the time of melting is excessively increased, and the surface properties of the obtained molded article are also poor.

On the other hand, when used as an automobile part, high rigidity and high impact resistance are often required. As a method for improving the impact resistance, a method of adding an amorphous rubber-like substance to a polypropylene resin by blending or multistage polymerization has been proposed (for example, Patent Document 4, Patent Document 5, and Patent Document 6). However, with this method, although impact resistance is high, the dispersibility of the rubber component to be added is poor and the molding becomes poor, or the foamability of the resin is not sufficient, and a foamed molded product with a high foaming ratio of 2 times or more is required. Couldn't get.
As described above, it has been difficult to obtain an injection foam molded article that has good injection foam moldability, excellent foam uniformity and surface appearance, and can be significantly reduced in weight at a high expansion ratio.

WO2005 / 026255 JP 61-152754 A Japanese Patent Laid-Open No. 7-109372 JP 2001-81251 A JP 2002-11748 A JP 11-309737 A

  An object of the present invention is to provide a polypropylene-based injection-foamed molded article having good moldability, excellent foaming uniformity and surface appearance, and capable of drastically reducing weight at a high foaming ratio, in view of the above-mentioned problems of the prior art. There is to do.

  As a result of intensive studies to solve the above problems, the present inventors have achieved a problem by using a propylene resin composition obtained by blending a specific propylene polymer with a foaming agent. The present invention has been made based on this finding.

That is, according to the first invention of the present invention, the component (A) insoluble in p-xylene at 25 ° C. satisfying the following requirements (A1) to (A5) and the following requirements (B1) to (B3): The propylene-based polymer (X) is composed of a component (B) soluble in p-xylene at 25 ° C. and satisfies the following requirements (i) to (iii), and the weight average molecular weight is 5 The foaming agent is added in an amount of 0.05 to 10% with respect to 100 parts by weight of the propylene polymer component (Y) of 0 to 94% by weight different from the propylene polymer (X) of 10,000 to 800,000. A polypropylene-based injection-foamed molded article obtained by injection-molding a propylene-based resin composition containing parts by weight is provided.
(A1) 20 to 95% by weight based on the total amount of the propylene-based polymer (X),
(A2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(A3) The isotactic triad fraction (mm) measured by 13C-NMR is 93% or more.
(A4) The strain hardening degree (λmax) in the measurement of elongational viscosity is 2.0 or more.
(A5) A propylene unit and an ethylene unit or an α-olefin unit are contained.
(B1) 5 to 80% by weight based on the total amount of the propylene polymer (X),
(B2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(B3) Contains propylene units, ethylene units and / or α-olefin units.
(I) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(Ii) The component insoluble in hot p-xylene is 0.3% by weight or less,
(Iii) The strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more.

  According to the second invention of the present invention, in the first invention, the propylene resin component is composed of 10 to 70% by weight of the propylene polymer (X) and 30 to 90% by weight of the propylene polymer (Y). A polypropylene-based injection-foamed molded article is provided.

According to the third aspect of the present invention, the component (A) insoluble in p-xylene at 25 ° C. satisfying the following requirements (A1) to (A5) and the following requirements (B1) to (B3) are satisfied 25 The foaming agent is 0.05 to 100 parts by weight with respect to 100 parts by weight of the propylene-based polymer (X) composed of the component (B) soluble in p-xylene at ° C and satisfying the following requirements (i) to (iii): A polypropylene-based injection-foamed molded article obtained by injection-molding a propylene-based resin composition containing 10 parts by weight is provided.
(A1) 20 to 95% by weight based on the total amount of the propylene-based polymer (X),
(A2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(A3) The isotactic triad fraction (mm) measured by 13C-NMR is 93% or more.
(A4) The strain hardening degree (λmax) in the measurement of elongational viscosity is 2.0 or more.
(A5) A propylene unit and an ethylene unit or an α-olefin unit are contained.
(B1) 5 to 80% by weight based on the total amount of the propylene polymer (X),
(B2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(B3) Contains propylene units, ethylene units and / or α-olefin units.
(I) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(Ii) The component insoluble in hot p-xylene is 0.3% by weight or less,
(Iii) The strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more.

  According to the fourth invention of the present invention, in any one of the first to third inventions, the component (B) in the propylene-based polymer (X) is further subjected to (B4) strain hardening degree in measurement of elongational viscosity ( (λmax) is 2.0 or more, and a polypropylene-based injection-foamed molded article is provided.

  According to the fifth invention of the present invention, in any one of the first to fourth inventions, the propylene polymer (X) has a crystalline propylene polymer segment as a side chain, and an amorphous propylene copolymer segment. There is provided a polypropylene-based injection-foamed molded article characterized in that it is composed of a polymer having a branched structure having a main chain as a main chain.

  According to the sixth invention of the present invention, in any one of the first to fifth inventions, the component (A) in the propylene polymer (X) has a crystalline propylene polymer segment as a side chain, and is amorphous. There is provided a polypropylene-based injection-foamed molded article characterized in that it is composed of a polymer having a branched structure having a main propylene copolymer segment as a main chain.

  According to the seventh invention of the present invention, in any one of the first to sixth inventions, the component (A) in the propylene polymer (X) contains an ethylene unit and has an ethylene content. A polypropylene-based injection-foamed molded article characterized by being 0.1 to 10% by weight is provided.

  According to the eighth invention of the present invention, in any one of the first to seventh inventions, the component (B) in the propylene-based polymer (X) contains an ethylene unit and has an ethylene content. A polypropylene-based injection-foamed molded article characterized by being 10 to 60% by weight is provided.

  According to a ninth aspect of the present invention, the polypropylene-based injection according to any one of the first to eighth aspects, wherein the foaming agent is at least one selected from a chemical foaming agent and a physical foaming agent. A foamed molded article is provided.

According to a tenth aspect of the present invention, there is provided a method for producing the polypropylene-based injection foam molding of any one of the first to ninth aspects by an injection foam molding method,
An injection step of injecting and filling the propylene-based resin composition into a mold cavity in a molten state or a semi-molten state; and a foaming step of foaming the propylene-based resin composition in the mold cavity. A method for producing a polypropylene-based injection-foamed molded article is provided.

  According to an eleventh aspect of the present invention, in the tenth aspect, the injection foam molding method is characterized in that a molten or semi-molten propylene resin composition in an amount less than the volume of the mold cavity is made of gold. Provided is a method for producing a polypropylene-based injection-foamed molded article characterized by a short shot method comprising an injection process for injection-filling a mold cavity and a foaming process for filling a void in the mold cavity with an expansion pressure by a foaming agent. Is done.

  According to a twelfth aspect of the present invention, in the tenth aspect of the present invention, the injection foam molding method includes a fixed mold and a movable mold capable of moving forward and backward, and the shape position of the final product. An injection step of injecting and filling a molten or semi-molten propylene resin composition into a mold cavity having a mold cavity clearance (t 0) smaller than the mold cavity clearance (t 1) corresponding to Polypropylene injection characterized in that it is a mold opening injection molding method comprising a foaming process in which a movable mold is retracted to a mold cavity clearance (t1) and a void in the mold cavity is filled with an expansion pressure by a foaming agent. A method for producing a foam molded article is provided.

  The polypropylene-based injection-foamed molded article of the present invention has a remarkable effect that the moldability is good, the foaming uniformity and the surface appearance are excellent, and the weight can be significantly reduced at a high foaming ratio. It can be suitably used for injection molding parts such as parts.

It is a figure of the description of the baseline of a chromatogram in GPC, and a section. It is a plot figure which shows an example of the extensional viscosity measured with the uniaxial extensional viscometer. It is a figure which shows an example of the TEM observation result of the propylene polymer (X) which concerns on this invention. It is a figure which shows an example of the TEM observation result of the propylene polymer (X) which concerns on this invention. It is a figure which shows an example of the TEM observation result of a normal propylene polymer.

The polypropylene-based injection-foamed molded article of the present invention is composed of the following components (A) and (B), and (i) has a weight average molecular weight (Mw) measured by GPC of 100,000 to 1,000,000 ( ii) a propylene-based polymer (X) having a component insoluble in hot p-xylene of 0.3% by weight or less, and (iii) a strain hardening degree (λmax) in the measurement of elongational viscosity of 1.1 or more, or It is obtained by injection foaming a propylene resin composition containing 0.05 to 10 parts by weight of a foaming agent with respect to 100 parts by weight of a propylene resin component comprising a propylene polymer (Y).
Component (A): Component (CXIS) insoluble in p-xylene at 25 ° C. that satisfies the following requirements (A1) to (A5).
(A1) 20% by weight to less than 95% by weight with respect to the total amount of the polymer,
(A2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(A3) The isotactic triad fraction (mm) measured by ¹³ C-NMR is 93% or more.
(A4) The strain hardening degree (λmax) in the measurement of elongational viscosity is 2.0 or more.
(A5) A propylene unit and an ethylene unit or an α-olefin unit are contained.
Component (B): Component (CXS) soluble in p-xylene at 25 ° C. that satisfies the following requirements (B1) to (B3).
(B1) 5% by weight to less than 80% by weight based on the total amount of the polymer,
(B2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(B3) Contains propylene units, ethylene units and / or α-olefin units.

Hereinafter, the components of the propylene-based resin composition, the production of the propylene-based resin composition, the polypropylene-based injection-foamed molded article, the production method thereof, and the like will be described in detail.
I. Components of propylene-based resin composition 1. Propylene resin component 1-1. Propylene polymer (X)
The propylene-based polymer (X) in the propylene-based resin component constituting the propylene-based resin composition used in the polypropylene-based injection-foamed molded article of the present invention is 25 ° C. with the component (A) insoluble in p-xylene at 25 ° C. And (i) has a weight average molecular weight (Mw) measured by GPC of 100,000 to 1,000,000, and (ii) is insoluble in hot p-xylene. The component is 0.3% by weight or less, and (iii) the strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more.

The propylene polymer (X) includes a crystalline propylene polymer component and a propylene polymer containing a copolymer in which a crystalline propylene polymer segment and a part of an amorphous propylene copolymer segment are chemically bonded. A propylene-ethylene copolymer obtained by sequentially producing an ethylene random copolymer component by multistage polymerization is preferred.
The multistage polymerization is preferably a two-stage polymerization in which the crystalline propylene polymer component is polymerized in the first stage and the propylene-ethylene random copolymer component is polymerized in the second stage.
At this time, a part of the crystalline propylene polymer produced in the first step is present in a state in which a part of the reaction is terminated in the state of the terminal vinyl group, so that when the second-stage polymerization is performed as it is, the terminal vinyl is As a macromonomer, the crystalline propylene polymer is involved in the second stage polymerization, the non-crystalline propylene copolymer segment (propylene-ethylene random copolymer segment) is the main chain, and the crystalline propylene polymer segment is the side chain. A copolymer having a certain branched structure is formed.
The present inventors consider that the factor that the propylene-based copolymer (X) according to the present invention exhibits good bubble uniformity can be attributed to the presence of this branched structure. In general, a polymer having a part composed of a chain of different monomers in one molecule, such as a real block copolymer or a graft copolymer, is a molecule that is considerably smaller than an ordinary phase separation structure, called a microphase separation structure. It is known to take a phase separation structure on the order of level, and such a fine phase separation structure greatly improves the uniformity of bubbles. Actually, in an electron micrograph (FIGS. 3 and 4) of the propylene polymer (X) (copolymer having a branched structure) according to the present invention, a normal propylene polymer (without a branched structure) Compared with 5)), a very fine dispersion structure of rubber domains is seen, which supports the above inference.
The propylene polymer (X) is a copolymer having a branched structure in which an amorphous propylene copolymer segment (propylene-ethylene random copolymer segment) is a main chain, and a crystalline propylene polymer segment is a side chain. Is included. In addition to propylene and ethylene, the component constituting the main chain may contain other unsaturated compounds, for example, α-olefins such as 1-butene, as long as the essence of the present invention is not significantly impaired. The component constituting the side chain is mainly propylene, and may contain a small amount of other unsaturated compounds, for example, α-olefins such as ethylene and 1-butene, as long as the essence of the present invention is not significantly impaired. Good.

As one of the techniques for determining whether or not there is a graft copolymer in which the propylene-ethylene random copolymer component as described above is a main chain and the crystalline propylene polymer component is a side chain, It is effective to use the strain hardening degree (λmax) obtained from the measurement of the extensional viscosity.
The strain hardening degree (λmax) is an index representing the strength at the time of melting, and when this value is large, there is an effect of improving the melt tension.
The degree of strain hardening is an index representing the nonlinearity of elongational viscosity, and it is usually said that this value increases as the molecular entanglement increases. Molecular entanglement is affected by the amount of branching and the length of the branched chain. Therefore, the greater the amount of branching and the length of branching, the greater the degree of strain hardening.
In the propylene polymer (X) according to the present invention, a propylene polymer having a terminal vinyl group is involved in the polymerization as a macromonomer during the production of the first-stage crystalline propylene polymer. Generate. Therefore, this degree of strain hardening is an index of the amount of terminal vinyl propylene polymer produced, and is preferably 1.1 or more.
Here, as to the method for measuring the strain hardening degree, the same value can be obtained in principle by any method as long as the uniaxial elongation viscosity can be measured. 42 (2001) 8663, and preferable measuring methods and measuring instruments include the following.

Measuring method 1:
Apparatus: Ales manufactured by Rheometrics
Jig: EXTENSIONAL VISUALITY FIXTURE, manufactured by TA Instruments
Measurement temperature: 180 ° C
Strain rate: 0.1 / sec
Preparation of test piece: A sheet of 18 mm × 10 mm and a thickness of 0.7 mm is formed by press molding.

Measurement method 2:
Apparatus: Toyo Seiki Co., Ltd., Melten Rheometer
Measurement temperature: 180 ° C
Strain rate: 0.1 / sec
Preparation of test piece: Extruded strands are prepared at a speed of 10 to 50 mm / min using an orifice with an inner diameter of 3 mm at 180 ° C. using a Capillograph manufactured by Toyo Seiki Co., Ltd.

Calculation method:
The elongational viscosity at a strain rate of 0.1 / sec is plotted as a log-log graph of time t (second) on the horizontal axis and elongational viscosity ηE (Pa · second) on the vertical axis. On the logarithmic graph, the viscosity immediately before strain hardening is approximated by a straight line, the maximum value (ηmax) of the extensional viscosity ηE until the amount of strain becomes 4.0 is obtained, and on the approximate straight line up to that time Let ηlin be the viscosity.
FIG. 2 is an example of a plot of elongational viscosity. ηmax / ηlin is defined as λmax and is used as an index of strain hardening degree.
The elongational viscosity and strain hardening degree calculated from the measuring method 1 and the measuring method 2 are, in principle, for measuring the inherent extensional viscosity and strain hardening degree of the substance and exhibit the same value. Therefore, either measurement method 1 or measurement method 2 may be used.

However, the measurement method 2 has a measurement restriction that a measurement sample hangs down when the molecular weight is relatively low (that is, when MFR> 2), and the measurement accuracy is lowered. In measurement method 1, when measuring a relatively high molecular weight (MFR <1), the measurement sample is deformed in a non-uniform manner, and distortion occurs at the time of measurement. There is a problem of measurement accuracy that is averaged and the strain hardening degree is estimated to be small.
Therefore, it is preferable for convenience to use the measuring method 1 for those having a low molecular weight and the measuring method 2 for those having a high molecular weight.
In general, in order to show a high degree of strain hardening, it is said that the entanglement molecular weight (Me) of 7000 or more of polypropylene is preferred as the branch length, and that the degree of strain hardening increases as the branch length increases.

The propylene-based polymer (X) according to the present invention is fractionated into a crystalline component and an amorphous component, and the amount of the component (B) soluble in p-xylene at 25 ° C. is based on the total amount of the propylene-based polymer (X). The amount of the component (A) insoluble in p-xylene at 25 ° C. is 20 to 95% by weight.
Here, a specific method for separating the crystalline component and the amorphous component is as follows.

Sorting method:
2 g of the sample was dissolved in 300 ml of p-xylene (0.5 mg / ml BHT: 2,6-di-tert-butyl-4-methylphenol) at 130 ° C. to obtain a solution, and then at 25 ° C. Leave for 48 hours. Thereafter, it is separated into a precipitated polymer and a filtrate. The p-xylene is evaporated from the filtrate and further dried under reduced pressure at 100 ° C. for 12 hours, and the component (CXS) soluble in xylene is recovered at 25 ° C. In addition, the precipitated polymer similarly removes the remaining p-xylene sufficiently, and becomes a component insoluble in xylene (CXIS) at 25 ° C.

As described above, the propylene polymer (X) is composed of a crystalline component (A) and an amorphous component (B), and a part of each component is a propylene-ethylene random copolymer segment. Includes a copolymer having a branched structure in which the crystalline propylene polymer segment is a side chain, and analytically, the following characteristics (i) to (iii), (A1) to (A5) ), (B1) to (B3).
(I): The weight average molecular weight (Mw) measured by GPC of the propylene polymer (X) is 100,000 to 1,000,000.
(Ii): The amount of components insoluble in hot paraxylene of the propylene polymer (X) is 0.3% by weight or less based on the total amount of the propylene polymer (X).
(Iii) The degree of strain hardening (λmax) in the measurement of the extensional viscosity of the propylene polymer (X) is 1.1 or more.
(A1): The amount of the component (A) is 20 to 95% by weight with respect to the total amount of the propylene polymer (X).
(A2): The weight average molecular weight (Mw) measured by GPC of a component (A) is 100,000-1 million.
(A3): Isotactic triad fraction (mm) measured by ¹³ C-NMR of component (A) is 93% or more.
(A4): The strain hardening degree (λmax) in the measurement of the extensional viscosity of the component (A) is 2.0 or more.
(A5): Component (A) contains a propylene unit and an ethylene unit or an α-olefin unit.
(B1): The amount of the component (B) is 5 to 80% by weight with respect to the total amount of the propylene polymer (X).
(B2): The weight average molecular weight (Mw) measured by GPC of a component (B) is 100,000-1 million.
(B3) The component (B) contains a propylene unit, an ethylene unit and / or an α-olefin unit.

Hereinafter, each item will be described sequentially.
(I): The weight average molecular weight (Mw) measured by GPC of the propylene polymer (X) is 100,000 to 1,000,000.
As the propylene polymer (X), those having a weight average molecular weight in the range of 100,000 to 1,000,000 are used.
The weight average molecular weight (Mw) is measured by a GPC measuring apparatus and conditions described later, and it is necessary that the Mw of the propylene polymer (X) is in the range of 100,000 to 1,000,000. When this Mw is smaller than 100,000, the melt processability is inferior and the mechanical strength is insufficient. On the other hand, when Mw exceeds 1 million, the melt viscosity is high and the melt processability is lowered. From the balance of melt processability and mechanical strength, it is in the above range, preferably Mw is 150,000 to 900,000, more preferably 200,000 to 800,000.
The value of the weight average molecular weight (Mw) is obtained by gel permeation chromatography (GPC), and the details of the measuring method and measuring instrument are as follows.

Equipment: GPC manufactured by Waters (ALC / GPC, 150C)
Detector: MIRAN, 1A, IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: o-dichlorobenzene (ODCB)
Measurement temperature: 140 ° C
Flow rate: 1.0 ml / min Injection volume: 0.2 ml

The sample is prepared by preparing a 1 mg / ml solution using ODCB (containing 0.5 mg / ml BHT) and dissolving it at 140 ° C. for about 1 hour. The baseline and section of the obtained chromatogram are performed as shown in FIG. Further, the conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a standard curve prepared in advance by standard polystyrene. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
Brand: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000
A calibration curve is generated by injecting 0.2 ml of a solution dissolved in ODCB (containing 0.5 mg / ml BHT) so that each is 0.5 mg / ml. The calibration curve uses a cubic equation obtained by approximation by the least square method. Viscosity equation used to conversion to molecular weight: [η] = K × M A uses the following values.
PS: K = 1.38 × 10 ⁻⁴ , A = 0.7
PP: K = 1.03 × 10 ⁻⁴ , A = 0.78

(Ii): The amount of components insoluble in hot p-xylene of the propylene-based polymer (X) is 0.3% by weight or less based on the total amount of the propylene-based polymer (X). Preferably it is 0.2 weight% or less, More preferably, it is 0.1 weight% or less. If it exceeds 0.3% by weight, the molded product may be crushed and the appearance may be deteriorated.
In the present invention, it is necessary that the component insoluble in hot p-xylene is 0.3% by weight or less. The method for measuring components insoluble in hot p-xylene is as follows.
A glass separable flask equipped with a stirrer is charged with 500 mg of a polymer in a bowl made of stainless steel 400 mesh (wire diameter 0.03 μm, aperture 0.034 mm, space ratio 27.8%). Fixed to. 700 ml of p-xylene containing 1 g of an antioxidant (BHT: 2,6-di-t-butyl-4-methylphenol) was added, and the polymer was dissolved while stirring at a temperature of 140 ° C. for 2 hours.
The soot containing the p-xylene insoluble part was collected, sufficiently dried and weighed to obtain the paraxylene insoluble part. The gel fraction (% by weight) defined as the hot p-xylene insoluble part was calculated by the following formula.
Gel fraction = [(residual amount in mesh g) / (prepared sample amount g)] × 100

Further, in order to have a small amount of gel or no gel as described above, it is important that there are no components having a very high molecular weight. Therefore, when the molecular weight distribution is measured by GPC, it is important that the molecular weight distribution does not spread to the high molecular weight side.
Therefore, the Q value (the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn)) measured by GPC is preferably 7 or less, more preferably 6 or less, and still more preferably 5 or less.
Moreover, in order not to extend extremely to the high molecular weight side, it is necessary that the molecular weight M (90) at which the integrated value in the curve is 90% by GPC is 2,000,000 or less.
Here, M (90) is a molecular weight at which the integral value in the curve is 90% by GPC measured by the GPC measuring apparatus and conditions described above, and in the present invention, M (90) is 2,000,000 or less. It is a feature. When M (90) exceeds 2,000,000, the high molecular weight component is excessively increased, and gel is generated or melt processability is deteriorated. Therefore, M (90) is 2,000,000 or less, preferably 1,500,000 or less, and more preferably 1,000,000.

(Iii) The degree of strain hardening (λmax) in the measurement of the extensional viscosity of the propylene polymer (X) is 1.1 or more. Preferably it is 2.0 or more, More preferably, it is 3.0 or more, More preferably, it is 4.0 or more.
The physical significance of the strain hardening degree is as described above. If this value is large, the closed cell ratio can be increased when injection foam molding is performed.
The length of branching is preferably an entanglement molecular weight of 7000 or more of polypropylene. Strictly speaking, this molecular weight is different from the weight average (Mw) measured by GPC. Therefore, the weight average molecular weight (Mw) value measured by GPC is preferably 15000 or more, and more preferably 30000 or more.

(A1): The amount of the component (A) is 20 to 95% by weight with respect to the total amount of the propylene polymer (X). Preferably it is 30 to 93 weight%, More preferably, it is 40 to 90 weight%.
This rule is a range with respect to the total amount of the propylene-based polymer (X) of the component (A), and those in this range are used from the balance of rigidity and impact resistance.

(A2): The weight average molecular weight (Mw) measured by GPC of a component (A) is 100,000-1 million.
Here, the weight average molecular weight (Mw) is measured by the GPC measuring apparatus and conditions described above, and the crystalline component (A) in the propylene polymer (X) has a weight average molecular weight of 100,000 to Those in the range of 1 million are used.
When this Mw is smaller than 100,000, the melt processability is inferior and the mechanical strength is insufficient. On the other hand, when Mw exceeds 1 million, the melt viscosity is high and the melt processability is lowered. From the balance of melt processability and mechanical strength, it is in the above range, preferably Mw is 150,000 to 900,000, more preferably 200,000 to 800,000.

(A3): Isotactic triad fraction (mm) measured by ¹³ C-NMR of component (A) is 93% or more.
The crystalline component (A) of the propylene polymer (X) according to the present invention has a stereoregularity in which the mm fraction of propylene unit three-chains obtained by ¹³ C-NMR is 93% or more.

  The mm fraction is the ratio of three propylene unit chains in which the direction of methyl branching in each propylene unit is the same among arbitrary three propylene unit chains composed of head-to-tail bonds in the polymer chain. This mm fraction is a value indicating that the steric structure of the methyl group in the polypropylene molecular chain is controlled isotactically, and the higher the value, the higher the degree of control. When the mm fraction of the crystalline component (A) is smaller than this value, the mechanical properties such as the elastic modulus, rigidity, heat resistance and strength of the molded product are lowered. Accordingly, the mm fraction is preferably 95% or more, and more preferably 96% or more.

The detail of the measuring method of mm fraction of the propylene unit 3 chain | strand by ¹³ C-NMR is as follows.
A sample of 375 mg was completely dissolved in 2.5 ml of deuterated 1,1,2,2, -tetrachloroethane in an NMR sample tube (10φ), and then measured at 125 ° C. by a proton complete decoupling method. The chemical shift was set to 74.2 ppm in the middle of the three peaks of deuterated 1,1,2,2-tetrachloroethane. The chemical shifts of other carbon peaks are based on this.
Flip angle: 90 degrees Pulse interval: 10 seconds Resonance frequency: 100 MHz or more Integration frequency: 10,000 times or more Observation range: -20 ppm to 179 ppm

The mm fraction is measured using a ¹³ C-NMR spectrum measured under the above conditions.
Spectra assignment is made according to the method described in detail in Japanese Patent Application No. 2006-311249, with reference to Macromolecules, (1975) 8 pp. 687, Polymer, 30 pages, 1350 (1989). Do.

(A4): The strain hardening degree (λmax) in the measurement of the extensional viscosity of the component (A) is 2.0 or more. Preferably it is 3.0 or more, More preferably, it is 4.0 or more. If it is less than 2.0, the foaming ratio of the molded product may be impaired.
The length of branching is preferably an entanglement molecular weight of 7000 or more of polypropylene. Moreover, as a weight average (Mw), it is 15000 or more, More preferably, it is 30000 or more.

The propylene polymer (X) according to the present invention satisfies (A5) in addition to the above (A1) to (A4).
(A5): Component (A) contains a propylene unit and an ethylene unit or an α-olefin unit.
As a unit constituting the crystalline component (A), it is necessary that propylene is arranged in an isotactic manner and has crystallinity. Further, ethylene or α-olefin may be contained as a comonomer unit within the range where crystallinity is exhibited. If there is an α, ω-diene unit, there is a concern about gelation due to crosslinking, so it is necessary that the α, ω-diene unit is not included.
As a kind of comonomer, ethylene or a linear alpha olefin is preferable, More preferably, it is ethylene.
Regarding comonomer content, it can contain arbitrary quantity in the range which crystallinity expresses.

(B1): The amount of the component (B) is 5 to 80% by weight with respect to the total amount of the propylene polymer (X). Preferably it is 7 to 70 weight%, More preferably, it is 10 to 60 weight%.
This rule is a range with respect to the total amount of the propylene polymer (X) of the component (B), and those in this range are used from the balance of rigidity and impact resistance.

(B2): The weight average molecular weight (Mw) measured by GPC of a component (B) is 100,000-1 million.
Here, the weight average molecular weight (Mw) is measured by the GPC measuring apparatus and conditions described above, and the amorphous component (B) in the propylene polymer (X) has a weight average molecular weight of 100,000. Those in the range of ~ 1 million are used.
When this Mw is smaller than 100,000, the melt processability is inferior and the mechanical strength is insufficient. On the other hand, when Mw exceeds 1 million, the melt viscosity is high and the melt processability is lowered. From the balance of melt processability and mechanical strength, it is in the above range, preferably Mw is 150,000 to 900,000, more preferably 200,000 to 800,000.

(B3): Component (B) contains a propylene unit, an ethylene unit and / or an α-olefin unit.
As a unit constituting the amorphous component (B), it is necessary that propylene and ethylene or α-olefin are copolymerized. Moreover, since there exists a concern about the gelatinization by bridge | crosslinking when an alpha, omega-diene unit exists, it is preferable not to contain an alpha, omega-diene unit.
The kind of comonomer is preferably ethylene or a linear α-olefin, more preferably ethylene, and the ethylene content is usually 10 to 60% by weight. From the viewpoint of improving impact resistance, 40 to 60% by weight is particularly preferable.

(B4): The strain hardening degree (λmax) in the measurement of the extensional viscosity of the component (B) is 2.0 or more.
As described above, when the value of the strain hardening degree (λmax) is large, it is possible to make it difficult to destroy the bubbles when the injection foam molding is performed, and to increase the closed cell ratio. Accordingly, when used for injection foam molding, 2.0 or more is preferable, and 2.0 to 20 is more preferable.

Regarding the method for producing the propylene polymer (X) according to the present invention, a macromer having a vinyl terminal can be produced, and a catalyst system capable of copolymerizing the macromer with propylene and ethylene may be used. It is a feature. Among them, by using a polymerization catalyst obtained by contacting the following catalyst components (a), (b) and (c),
(I) first step of polymerizing propylene alone, or propylene and ethylene or α-olefin, and polymerizing ethylene or α-olefin with respect to all monomer components in an amount of 0 to 10% by weight; and (ii) propylene and ethylene Or a second step in which α-olefin is polymerized and ethylene is polymerized in an amount of 10 to 70% by weight based on the total monomer components;
The propylene-based polymer (X) according to the present invention can be produced with high productivity by the process having the above.

(1) Component (a):
The catalyst component (a) used for the production of the propylene polymer (X) is a metallocene compound having hafnium as a central metal represented by the following general formula (1).

In general formula (1), each R ₁ is independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a halogen-containing alkyl group having 1 to 6 carbon atoms, a silicon-containing alkyl group having 1 to 6 carbon atoms, or carbon. An aryl group having 6 to 16 carbon atoms, a halogen-containing aryl group having 6 to 16 carbon atoms, a nitrogen or oxygen having 4 to 16 carbon atoms, and a heterocyclic group containing sulfur, and at least one of two R ₁ is carbon A heterocyclic group containing nitrogen, oxygen, or sulfur of several 4 to 16 is shown. Two R _{1 s} may be the same or different from each other. Each R ₂ is independently an alkyl group having 1 to 6 carbon atoms, a halogen-containing alkyl group having 1 to 6 carbon atoms, a silicon-containing alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms. , A halogen-containing aryl group having 6 to 16 carbon atoms, a silicon-containing aryl group having 6 to 16 carbon atoms, a nitrogen or oxygen having 6 to 16 carbon atoms, and a heterocyclic group containing sulfur. Two R ₂ may be the same as or different from each other.
X and Y are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon having 1 to 20 carbon atoms. Represents a group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, Q is a divalent hydrocarbon group having 1 to 20 carbon atoms, 1 carbon atom Represents a silylene group, an oligosilylene group, or a germylene group which may have ˜20 hydrocarbon groups.

The heterocyclic group containing nitrogen, oxygen or sulfur having 4 to 16 carbon atoms of R ₁ is preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group, or a substituted 2 group. -Furfuryl group, more preferably a substituted 2-furyl group.
Moreover, as a substituted 2-furyl group, a substituted 2-thienyl group, and a substituted 2-furfuryl group, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, and a propyl group, Examples thereof include halogen atoms such as fluorine atom and chlorine atom, alkoxy groups having 1 to 6 carbon atoms such as methoxy group and ethoxy group, and trialkylsilyl groups. Of these, a methyl group and a trimethylsilyl group are preferable, and a methyl group is particularly preferable.
R ₁ is particularly preferably a 2- (5-methyl) -furyl group. Moreover, it is preferable that two R ₁ are mutually the same.

R ₂ is preferably an aryl group having 6 to 16 carbon atoms, a halogen-containing aryl group having 6 to 16 carbon atoms, or a silicon-containing aryl group having 6 to 16 carbon atoms. Such an aryl group has 6 to 16 carbon atoms. 1 or more hydrocarbon groups having 1 to 6 carbon atoms, silicon-containing hydrocarbon groups having 1 to 6 carbon atoms, and halogen-containing hydrocarbon groups having 1 to 6 carbon atoms on the aryl cyclic skeleton. You may have as a substituent.
R ₂ is preferably at least one of phenyl group, 4-t-butylphenyl group, 2,3-dimethylphenyl group, 3,5-dit-butylphenyl group, 4-phenyl-phenyl group, chlorophenyl group. , A naphthyl group, or a phenanthryl group, more preferably a phenyl group, a 4-t-butylphenyl group, or a 4-chlorophenyl group. Moreover, the case where two R < ₂ > is mutually the same is preferable.

In general formula (1), X and Y are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, or a carbon number of 1 to 20 A silicon-containing hydrocarbon group, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms. As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.
Specific examples of the hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and s-butyl, vinyl, propenyl, Examples include alkenyl groups such as cyclohexenyl, arylalkyl groups such as benzyl, arylalkenyl groups such as trans-styryl, and aryl groups such as phenyl, tolyl, 1-naphthyl, and 2-naphthyl.
Specific examples of the oxygen-containing hydrocarbon group having 1 to 20 carbon atoms include alkoxy groups such as methoxy, ethoxy, propoxy and butoxy, allyloxy groups such as phenoxy and naphthoxy, arylalkoxy groups such as phenylmethoxy, and furyl groups. And oxygen-containing heterocyclic groups.
Specific examples of the nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms include alkylamino groups such as methylamino, dimethylamino, ethylamino and diethylamino, arylamino groups such as phenylamino and diphenylamino, (methyl) ( (Alkyl) (aryl) amino groups such as phenyl) amino, and nitrogen-containing heterocyclic groups such as pyrazolyl and indolyl.

In the halogenated hydrocarbon group having 1 to 20 carbon atoms, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated hydrocarbon group is a compound in which, when the halogen atom is, for example, a fluorine atom, the fluorine atom is substituted at an arbitrary position of the hydrocarbon group. Specific examples include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, and trichloromethyl groups.
Specific examples of the silicon-containing hydrocarbon group having 1 to 20 carbon atoms include trialkylsilylmethyl groups such as trimethylsilylmethyl and triethylsilylmethyl, dialkyl such as dimethylphenylsilylmethyl, diethylphenylsilylmethyl, and dimethyltolylsilylmethyl. (Alkyl) (aryl) silylmethyl group and the like can be mentioned.

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

Of the compounds represented by the general formula (1), preferred compounds are specifically exemplified below.
Dimethylsilylenebis (2- (2-furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-thienyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2 -(5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, diphenylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylgermylenebis (2- (2- (5-Methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylgermylenebis (2- (2- (5-methyl) -thienyl) -4-phenyl-indenyl) hafnium Dichloride, dimethylsilylenebis (2- (2- (5-t Butyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-trimethylsilyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2 -(5-phenyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (4,5-dimethyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylene Bis (2- (2-benzofuryl) -4-phenyl-indenyl) hafnium dichloride, diphenylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis ( 2- (2- (5-Methyl -Furyl) -4-methyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-isopropyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-furfuryl) ) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (4-chlorophenyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2 -(5-Methyl) -furyl) -4- (4-fluorophenyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (4-trifluoromethyl) Phenyl) -indenyl) hafnium dichloride, dimethylsilylenebi (2- (2- (5-methyl) -furyl) -4- (4-t-butylphenyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-furyl) -4- (1-naphthyl) ) -Indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-furyl) -4- (2-naphthyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-furyl) -4- (2-phenanthryl) ) -Indenyl) hafnium dichloride, dimethylsilylenebis (2- (2-furyl) -4- (9-phenanthryl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl)- 4- (1-naphthyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2 (5-Methyl) -furyl) -4- (2-naphthyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (2-phenanthryl) -indenyl) Hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (9-phenanthryl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-t-butyl) -Furyl) -4- (1-naphthyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-t-butyl) -furyl) -4- (2-naphthyl) -indenyl) hafnium dichloride, Dimethylsilylenebis (2- (2- (5-t-butyl) -furyl) -4- (2-phenanthryl) -indene ) Hafnium dichloride, dimethylsilylene bis (2- (2- (5-t-butyl) -furyl) -4- (9-phenanthryl) -indenyl) hafnium dichloride, dimethylsilylene (2-methyl-4-phenyl-indenyl) ) (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylene (2-methyl-4-phenyl-indenyl) (2- (2- (5-methyl)- And thienyl) -4-phenyl-indenyl) hafnium dichloride.

  Of these, more preferred are dimethylsilylene bis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylgermylene bis (2- (2- (5-methyl). ) -Thienyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (4-chlorophenyl) -indenyl) hafnium dichloride, dimethylsilylenebis (2 -(2- (5-methyl) -furyl) -4-naphthyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (4-t-butylphenyl) -Indenyl) hafnium dichloride, dimethylsilylene (2-methyl-4-phenyl-indenyl) ( - (2- (5-methyl) - furyl) -4-phenyl - indenyl) hafnium dichloride.

  Also particularly preferred are dimethylsilylene bis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride, dimethylsilylene bis (2- (2- (5-methyl) -furyl). ) -4-naphthyl-indenyl) hafnium dichloride, dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4- (4-t-butylphenyl) -indenyl) hafnium dichloride.

(2) Component (b):
Next, the catalyst component (b) is an ion-exchange layered silicate.
In the present invention, an ion-exchange layered silicate (hereinafter sometimes abbreviated as silicate) has a crystal structure in which surfaces formed by ionic bonds and the like are stacked in parallel with each other by a binding force, and , Refers to a silicate compound in which the contained ions are exchangeable. Most silicates are naturally produced mainly as the main component of clay minerals, and are generally dispersed / swelled in water and purified by differences in sedimentation rate, etc., but they can be completely removed. Although it may be difficult and contains impurities (quartz, cristobalite, etc.) other than ion-exchangeable layered silicate, they may be included. Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, it may be preferable to pure silicate, and such a complex is also included in component (b).
In addition, a raw material refers to the silicate of the previous stage which performs the chemical process mentioned later. The silicate is not limited to a natural product, and may be an artificial synthetic product.
In addition, if it has ion exchange properties before chemical treatment, silicates whose physical and chemical properties have been changed by the treatment and the ion exchange properties and layer structure have been lost are also ion exchange layered. Treat as silicate.

Specific examples of the ion-exchange layered silicate include, for example, layered silicates having a 1: 1 type structure or a 2: 1 type structure described in Haruo Shiramizu “Clay Mineralogy” Asakura Shoten (1988) and the like. Can be mentioned.
The 1: 1 type structure is based on the stacking of the 1: 1 layer structure in which one layer of tetrahedron sheet and one layer of octahedron sheet are combined as described in the above “clay mineralogy” and the like. The 2: 1 type structure is a structure based on a stack of 2: 1 layer structures in which two layers of tetrahedral sheets sandwich one layer of octahedral sheets.

  Specific examples of ion-exchangeable layered silicates in which the 1: 1 layer is the main constituent layer include kaolin silicates such as dickite, nacrite, kaolinite, metahalloysite, halloysite, chrysotile, risardite, antigolite, etc. Examples include serpentine silicates.

Specific examples of ion-exchange layered silicates with 2: 1 layers as the main constituent layers include smectite group silicates such as montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, and vermiculite groups such as vermiculite. Examples thereof include mica group silicates such as silicate, mica, illite, sericite, and sea green stone, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group, and the like. These may form a mixed layer.
Among these, the main component is preferably an ion-exchange layered silicate having a 2: 1 type structure. More preferably, the main component is a smectite group silicate, and still more preferably, the main component is montmorillonite.

  The type of interlayer cations (cations contained between the layers of the ion-exchange layered silicate) is not particularly limited, but as a main component, alkali metals of the first group of the periodic table such as lithium and sodium, calcium and magnesium Alkali earth metals of Group 2 of the periodic table, etc., or transition metals such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, gold, etc. are relatively It is preferable in that it can be easily obtained.

  The ion-exchange layered silicate may be used in a dry state or in a slurry state in a liquid. In addition, the shape of the ion-exchange layered silicate is not particularly limited, and may be a naturally produced shape, a shape when artificially synthesized, or a shape by operations such as pulverization, granulation, and classification. You may use the processed ion exchange layered silicate. Of these, the granulated ion-exchange layered silicate is particularly preferable because it gives good polymer particle properties when the ion-exchange layered silicate is used as a catalyst component.

Processing of the shape of the ion-exchange layered silicate such as granulation, pulverization, and classification may be performed before the chemical treatment (that is, the following chemical treatment is performed on the ion-exchange layered silicate that has been processed in advance). The shape may be processed after chemical treatment.
Examples of the granulation method used here include stirring granulation method, spray granulation method, rolling granulation method, briquetting, compacting, extrusion granulation method, fluidized bed granulation method, emulsion granulation method. , Submerged granulation method, compression molding granulation method, and the like, but are not particularly limited. Preferably, agitation granulation method, spray granulation method, rolling granulation method, and fluidized granulation method are exemplified, and particularly preferably, agitation granulation method and spray granulation method are exemplified.
When spray granulation is performed, water or an organic solvent such as methanol, ethanol, chloroform, methylene chloride, pentane, hexane, heptane, toluene, and xylene is used as a dispersion medium for the raw slurry. Preferably, water is used as a dispersion medium. The concentration of the component (b) in the raw slurry liquid for spray granulation from which spherical particles are obtained is 0.1 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight. . The inlet temperature of the hot air for spray granulation from which spherical particles are obtained varies depending on the dispersion medium, but is 80 to 260 ° C, preferably 100 to 220 ° C when water is taken as an example.

  In granulation, in order to obtain a carrier having high particle strength and to improve propylene polymerization activity, the silicate is refined as necessary. The silicate may be refined by any method. As a method for miniaturization, either dry pulverization or wet pulverization is possible. Preferably, wet pulverization using water as a dispersion medium and utilizing the swellability of silicate, for example, a method using forced stirring using polytron or the like, a method using dyno mill, pearl mill, or the like. The average particle size before granulation is 0.01 to 3 μm, preferably 0.05 to 1 μm.

  Moreover, you may use organic substance, an inorganic solvent, inorganic salt, and various binders in the case of granulation. Examples of the binder used include magnesium chloride, aluminum sulfate, aluminum chloride, magnesium sulfate, alcohols, glycols and the like.

  The spherical particles obtained as described above preferably have a compression fracture strength of 0.2 MPa or more in order to suppress crushing and fine powder generation in the polymerization step. The particle size of the granulated ion-exchange layered silicate is in the range of 0.1 to 1000 μm, preferably 1 to 500 μm. There is no particular limitation on the pulverization method, and either dry pulverization or wet pulverization may be used.

  The ion-exchange layered silicate of the catalyst component (b) can be used as it is without any particular treatment, but it is desirable to perform the chemical treatment. The chemical treatment of the ion-exchange layered silicate refers to acids and salts. It means that an alkali, an organic substance or the like is brought into contact with an ion-exchange layered silicate.

  A common effect of chemical treatment is to exchange interlayer cations. In addition, various chemical treatments have the following various effects. For example, according to the acid treatment with acids, impurities on the silicate surface can be removed and the surface area can be increased by eluting cations such as Al, Fe, and Mg in the crystal structure. This contributes to increasing the acid strength of the silicate and increasing the amount of acid sites per unit weight.

  In alkali treatment with alkalis, the crystal structure of the clay mineral is destroyed, resulting in a change in the structure of the clay mineral.

  After carrying out the chemical treatment, it is possible to remove excess treatment agent and ions eluted by the treatment, which is preferable. At this time, generally, a liquid such as water or an organic solvent is used. After the dehydration, drying is performed. In general, the drying temperature can be 100 to 800 ° C, preferably 150 to 600 ° C. Exceeding 800 ° C. is not preferable because it may cause structural destruction of the silicate.

  Since these ion-exchange layered silicates have different characteristics depending on the drying temperature even if they are not structurally destroyed, it is preferable to change the drying temperature depending on the application. The drying time is usually 1 minute to 24 hours, preferably 5 minutes to 4 hours, and the atmosphere is preferably dry air, dry nitrogen, dry argon, or under reduced pressure. It does not specifically limit regarding a drying method, It can implement by various methods.

As the catalyst component (b) according to the present invention, the chemically-exchanged ion-exchange layered silicate has an Al / Si atomic ratio of 0.01 to 0.25, preferably 0.03 to 0.24. And more preferably in the range of 0.05 to 0.23. The Al / Si atomic ratio is considered to be an index of the acid treatment strength of the clay portion. Moreover, as a method of controlling the Al / Si atomic ratio within the above range, a method of performing chemical treatment using montmorillonite as the ion-exchange layered silicate before chemical treatment can be mentioned.
Aluminum and silicon in the ion-exchange layered silicate are measured by a method of preparing a calibration curve by a chemical analysis method by JIS method and quantifying with a fluorescent X-ray.

(3) Component (c):
The catalyst component (c) is an organoaluminum compound, and preferably an organoaluminum compound represented by the general formula: (AlR _n X _3-n ) _m is used. In formula, R represents a C1-C20 alkyl group, X represents a halogen, hydrogen, an alkoxy group, or an amino group, n represents 1-3, m represents the integer of 1-2, respectively. The organoaluminum compounds can be used alone or in combination.

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

(4) Catalyst adjustment:
The catalyst for olefin polymerization according to the present invention comprises the above component (a), component (b) and component (c). These may be contacted in the polymerization tank or outside the polymerization tank and preliminarily polymerized in the presence of olefin.
The olefin refers to a hydrocarbon having at least one carbon-carbon double bond, and examples thereof include ethylene, propylene, 1-butene, 1-hexene, 3-methylbutene-1, styrene, divinylbenzene, and the like. There is no restriction | limiting, You may use the mixture of these and another olefin. An olefin having 3 or more carbon atoms is preferable.

The amount of component (a), component (b) and component (c) used is arbitrary, but the ratio of the transition metal in component (b) to the aluminum in component (c) is the component (a). It is preferable to make it contact so that it may become 0.1-1000 (micromol): 0-100,000 (micromol) per 1g. In addition to the component (a), other types of complexes may be used for the purpose of more efficiently producing the propylene polymer (X) according to the present invention.
In this case, it is preferable to combine a metallocene compound capable of copolymerizing the terminal vinyl macromer produced by the catalyst component (a) and producing a high molecular weight polymer compared to the catalyst component (a).
As a particularly preferred metallocene compound, a catalyst component (a-2) represented by the following general formula (2) can be mentioned.

The compound represented by the general formula (2) is a metallocene compound, and in the general formula (2), Q ²¹ is a binding group that bridges two conjugated five-membered ring ligands, and has a carbon number. A divalent hydrocarbon group having 1 to 20 carbon atoms, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms, or a germylene group having a hydrocarbon group having 1 to 20 carbon atoms, preferably a substituted silylene group or a substituted germylene group. It is. The substituent bonded to silicon and germanium is preferably a hydrocarbon group having 1 to 12 carbon atoms, and two substituents may be linked. Specific examples include methylene, dimethylmethylene, ethylene-1,2-diyl, dimethylsilylene, diethylsilylene, diphenylsilylene, methylphenylsilylene, 9-silafluorene-9,9-diyl, dimethylsilylene, diethylsilylene, Examples thereof include diphenylsilylene, methylphenylsilylene, 9-silafluorene-9,9-diyl, dimethylgermylene, diethylgermylene, diphenylgermylene, methylphenylgermylene and the like.
Me is zirconium or hafnium, preferably hafnium.
Furthermore, X ²¹ and Y ²¹ are auxiliary ligands, and react with the cocatalyst of component [b] to generate an active metallocene having olefin polymerization ability. Therefore, as long as this purpose is achieved, X ²¹ and Y ²¹ are not limited to the type of ligand, and each independently represents hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms, An alkoxy group having 1 to 20 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, a trifluoromethanesulfonic acid group, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms is shown. .

In general formula (2), R ²¹ and R ²² are each independently a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms. is there. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, n-pentyl, i-pentyl, n-hexyl, and preferably methyl. , Ethyl, n-propyl.
R ²³ and R ²⁴ each independently contains a halogen having 6 to 30 carbon atoms, preferably 6 to 24 carbon atoms, or a plurality of hetero elements selected from these. A good aryl group. Preferable examples include phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4 -(2-fluorobiphenylyl), 4- (2-chlorobiphenylyl), 1-naphthyl, 2-naphthyl, 3,5-dimethyl-4-tert-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl Etc.

Non-limiting examples of the metallocene compound include the following.
For example, dichloro {1,1′-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazulenyl)} hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylene Bis {2-methyl-4- (4-trimethylsilylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-chloro-4-t-butylphenyl) ) -4-Hydroazulenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- ( -Methyl-4-t-butylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl} ] Hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2 -Methyl-4- (1-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2-naphthyl) -4-hydroazurenyl}] hafnium, dichloro [ 1,1′-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4 -Hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-Methyl-4- (9-phenanthryl) -4-hydroazurenyl}] hafnium, dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl) -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}] hafnium, dic B [1,1′-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-tert-butylphenyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylgermylenebis {2 -Methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazulenyl}] hafnium, dichloro [1,1′-dimethylgermylenebis {2-methyl-4- (4-t-butylphenyl) -4 -Hydroazurenyl}] hafnium, dichloro [1,1 ′-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium, and the like.

  When using other types of catalyst component (a-2), the ratio of the amount of catalyst component (a-2) to the total amount of catalyst component (a) and catalyst component (a-2) is propylene-based. Although it is arbitrary as long as it satisfies the characteristics of the polymer (X), it is preferably 0.01 to 0.7. By changing this ratio, it is possible to adjust the balance between melt physical properties and catalyst activity, and particularly preferably for the production of propylene-based polymers for applications that require higher melt properties and high catalyst activity, The range is from 0.10 to 0.60, and more preferably from 0.2 to 0.5.

  The order of contacting the component (a), the component (b) and the component (c) is arbitrary, and after contacting two of these components, the remaining one component may be contacted, The components may be contacted simultaneously. In these contacts, a solvent may be used for sufficient contact. Examples of the solvent include aliphatic saturated hydrocarbons, aromatic hydrocarbons, aliphatic unsaturated hydrocarbons, halides thereof, and prepolymerized monomers. Specific examples of the aliphatic saturated hydrocarbon and the aromatic hydrocarbon include hexane, heptane, toluene and the like. Further, as a prepolymerized monomer, propylene can be used as a solvent.

[Prepolymerization]:
As described above, the catalyst according to the present invention is preferably subjected to a prepolymerization process comprising a small amount of polymerization by bringing an olefin into contact therewith. The olefin used is not particularly limited, but as described above, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcyclohexane. Examples include alkanes and styrene. The olefin feed method may be any method such as a feed method for maintaining the olefin at a constant speed or in a constant pressure state, a combination thereof, or a stepwise change.
The prepolymerization temperature and time are not particularly limited, but are preferably in the range of −20 ° C. to 100 ° C. and 5 minutes to 24 hours, respectively. Further, the prepolymerization amount is preferably 0.01 to 100, more preferably 0.1 to 50, by weight ratio of the prepolymerized polymer to the component (b). Further, the component (c) can be added or added during the prepolymerization.
A method of coexisting a polymer such as polyethylene or polypropylene and a solid of an inorganic oxide such as silica or titania at the time of contacting or after the contact of the above components is also possible.
The catalyst may be dried after the prepolymerization. The drying method is not particularly limited, and examples thereof include reduced-pressure drying, heat drying, and drying by circulating a drying gas. These methods may be used alone or in combination of two or more methods. May be. In the drying step, the catalyst may be stirred, vibrated, fluidized, or allowed to stand.

[Polymerization method]:
As the polymerization method, any mode can be adopted as long as the olefin polymerization catalyst comprising the component (a), the component (b) and the component (c) and the monomer come into efficient contact. Specifically, a slurry method using an inert solvent, a bulk polymerization method using propylene as a solvent without substantially using an inert solvent, or a gas phase polymerization method for maintaining each monomer in a gaseous state without using a liquid solvent. Etc. can be adopted.
As the polymerization method, a method of performing continuous polymerization, batch polymerization, or prepolymerization is also applied.
Further, the number of polymerization stages is not particularly limited as long as the substance of the present invention can be produced. However, it is possible to employ a mode such as two stages of bulk polymerization, gas phase polymerization after bulk polymerization, and two stages of gas phase polymerization, and more. It is possible to produce with the number of polymerization stages.
However, in order to obtain the compound having the molecular weight and molecular weight distribution disclosed in the present invention, the first step is performed by bulk polymerization and the second step is performed by gas phase polymerization, or both the first step and the second step are performed. It is preferable to carry out by phase polymerization.

[First step]:
In the case of slurry polymerization, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene, toluene, or the like is used alone or as a polymerization solvent. The polymerization temperature is 0 to 150 ° C., and hydrogen can be used supplementarily as a molecular weight regulator. The polymerization pressure is suitably from 0 to 3 MPaG, preferably from 0 to 2 MPaG.
In the case of the bulk polymerization method, the polymerization temperature is 0 to 80 ° C, preferably 60 to 80 ° C, more preferably 65 to 75 ° C. The polymerization pressure is 0 to 5 MPaG, preferably 0 to 4 MPaG.
In the case of gas phase polymerization, the polymerization temperature is 0 to 200 ° C, preferably 60 to 120 ° C, and more preferably 70 to 100 ° C. The polymerization pressure is suitably from 0 to 4 MPaG, preferably from 0 to 3 MPaG.

[Second step]:
In the case of gas phase polymerization, the polymerization temperature is 0 to 200 ° C, preferably 20 to 90 ° C, more preferably 30 to 80 ° C. In addition, hydrogen can be used as a molecular weight regulator. The polymerization pressure is suitably from 0 to 4 MPaG, preferably from 0 to 3 MPaG.

Here, the produced propylene-ethylene (or α-olefin) copolymer is partially copolymerized with a low vinyl terminal content, and both the main chain and the side chain are (non-crystalline) propylene-ethylene random copolymer. It is considered that a polymer having a branched structure having a polymer segment is formed. In this case, the lower the ethylene content in the amorphous propylene-ethylene random copolymer, the higher the vinyl terminal content. That is, by reducing the ethylene content in the amorphous propylene-ethylene random copolymer, it is possible to increase λmax of the CXS component of the propylene-based polymer of the present invention.
Therefore, in order to control the λmax of the CXS component to 2 or more, it is preferable that the ethylene content is 10 wt% to less than 40 wt%, in order to produce a polymer having a desired composition using ethylene as a comonomer. Therefore, it is necessary to control the ethylene gas composition in the gas phase to 10 mol% or more, preferably 15 mol% or more, and more preferably 20 mol% or more. The upper limit is 65 mol% or less, preferably 60 mol% or less, and more preferably 50 mol% or less.
Conversely, when the ethylene content is 40 wt% to 60 wt%, the λmax of the CXS component becomes less than 2, and when ethylene is used as a comonomer, it is necessary to control the ethylene gas composition in the gas phase to 50 mol% or more. Yes, preferably 60 mol% or more, more preferably 65 mol% or more. Moreover, regarding an upper limit, it is 90 mol% or less, Preferably it is 87 mol% or less, More preferably, it is 85 mol% or less.

  The propylene polymer (X) according to the present invention thus obtained has (i) a weight average molecular weight (Mw) measured by GPC of 100,000 to 1,000,000, and (ii) a component insoluble in hot p-xylene. (Iii) The strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more, and the crystalline segment is grafted as a side chain to the amorphous segment. Including polymers. In particular, such graft copolymers are present in the CXIS component (A). Polymerization mechanism in which the crystalline segment becomes a side chain and the non-crystalline segment becomes the main chain, in which the macromer of the crystalline component is produced in the first stage and copolymerized with the amorphous component in the second stage. From the point of view, it is natural.

1-2. Propylene polymer (Y)
About the propylene-type resin component which comprises the propylene-type resin composition used for the polypropylene-type injection foaming molding of this invention, a propylene-type polymer (Y) can be used together with the said propylene-type polymer (X). The propylene polymer (Y) is different from the propylene polymer (X). Specifically, the propylene homopolymer, the propylene / ethylene random copolymer, the propylene / ethylene block copolymer, etc. A copolymer of propylene and an α-olefin excluding propylene, a copolymer of propylene and a vinyl compound, a copolymer of propylene and a vinyl ester, a copolymer of propylene and an unsaturated organic acid or a derivative thereof, Examples include copolymers of propylene and conjugated dienes, copolymers of propylene and nonconjugated polyenes, and mixtures thereof. Among them, propylene homopolymers, propylene / ethylene random copolymers, propylene / ethylene block copolymers, and the like. Polymers and mixtures thereof are preferred.

  The propylene polymer (Y) has a weight average molecular weight in the range of 50,000 to 800,000. The measurement of a weight average molecular weight is the same as the measuring method in propylene polymer (X). When the weight average molecular weight of the propylene-based polymer (Y) is smaller than 50,000, the foaming cell is broken and the foaming ratio is lowered. When the weight average molecular weight exceeds 800,000, the appearance of the foamed molded product becomes inferior, for example, a flow mark is generated. From the balance of expansion ratio and appearance, the weight average molecular weight is preferably in the range of 80,000 to 650,000, more preferably in the range of 100,000 to 500,000.

  Furthermore, the propylene-based polymer (Y) preferably has a strain hardening degree (λmax) in the measurement of elongational viscosity of less than 1.5, more preferably less than 1.1, and even more preferably 0.9 or more. It is less than 1.05. By carrying out like this, the external appearance of a foaming molding is improved more.

The method for producing the propylene-based polymer (Y) is not particularly limited, and can be appropriately selected from known methods and conditions, but a propylene-based resin having no branched structure can be obtained. The method and conditions are preferable.
As the polymerization catalyst, a highly stereoregular catalyst is usually used, and examples thereof include a Ziegler catalyst and a metallocene catalyst.
As such a production method, a production process such as a gas phase polymerization method, a liquid phase bulk polymerization method, or a slurry polymerization method in the presence of the catalyst is generally used.

The propylene resin component is composed of 6 to 100% by weight of the propylene polymer (X) and 0 to 94% by weight of the propylene polymer (Y).
If the propylene polymer (X) is 100% by weight in the propylene resin component, the moldability is good due to its characteristic properties, and the foam molded product has a high expansion ratio, uniform foaming, surface Excellent appearance.
On the other hand, when the propylene polymer (X) and the propylene polymer (Y) are used in combination in the propylene resin component, good moldability is obtained by the propylene polymer (X), and foam molding is performed. The propylene polymer (X) is a total amount of the propylene polymer (X) and the propylene polymer (Y) so that a high foaming ratio and good foaming uniformity can be provided. At least 6% by weight, preferably at least 7% by weight, more preferably at least 8% by weight, even more preferably at least 10% by weight (6% by weight or more, preferably 7% by weight or more, more preferably 8% by weight or more, More preferably, it is 10% by weight or more. In order to further take into account the properties of the propylene polymer (Y), the propylene polymer (Y) is propylene. At least 10 wt%, preferably at least 20 wt%, more preferably at least 30 wt% (10 wt% or more, preferably 20 wt% or more) based on the total amount of the polymer (X) and the propylene-based polymer (Y). , More preferably 30% by weight or more).

2. Foaming agent The foaming agent that can be used in the present invention is not particularly limited as long as it can be usually used for injection foam molding such as a chemical foaming agent and a physical foaming agent. The chemical foaming agent is mixed with the resin in advance and then supplied to the injection molding machine, and decomposes in the cylinder to generate a gas such as carbon dioxide. Examples of the foaming agent include inorganic compounds such as ammonium carbonate and sodium bicarbonate, and organic compounds such as azo compounds, sulfohydrazide compounds, nitroso compounds, and azide compounds. Examples of the azo compound include azodicarbonamide (ADCA), 2,2-azoisobutyronitrile, azohexahydrobenzonitrile, diazoaminobenzene, and the like. Examples of the sulfohydrazide compound include benzenesulfohydrazide, benzene-1,3-disulfohydrazide, diphenylsulfone-3,3-disulfohydrazide, diphenyloxide-4,4-disulfohydrazide and the like. Examples of the nitroso compound include N, N-dinitrosopentamethylenetetramine (DNPT), N, N-dimethyl terephthalate and the like. Examples of the azide compound include terephthalazide and p-tert-butylbenzazide.

  A physical foaming agent is injected into a molten resin in a cylinder of a molding machine as a gaseous or supercritical fluid, dispersed or dissolved, and functions as a foaming agent by being released from pressure after being injected into a mold. Is. Physical foaming agents include aliphatic hydrocarbons such as propane and butane, alicyclic hydrocarbons such as cyclobutane and cyclopentane, halogenated hydrocarbons such as chlorodifluoromethane and dichloromethane, nitrogen, carbon dioxide, air, etc. Inorganic gas. You may use these individually or in mixture of 2 or more types.

  Among these foaming agents, normal injection molding machines can be used safely, and uniform fine bubbles are easily obtained. Chemical foaming agents are inorganic chemical foaming agents, physical foaming agents are nitrogen and carbon dioxide. Inorganic gas such as air is preferable. These foaming agents include, for example, foaming aids such as organic acids such as citric acid and inorganic fine particles such as talc and lithium carbonate, in order to stably and uniformly make the foamed foam air bubbles. A nucleating agent such as may be added. In general, the inorganic chemical foaming agent is preferably used as a masterbatch of a polyolefin resin having a concentration of 10 to 50% by weight from the viewpoints of handleability, storage stability, and dispersibility in a propylene polymer.

  The amount of the foaming agent used may be appropriately set depending on the foaming ratio of the final product, the type of foaming agent, and the resin temperature at the time of molding. Usually, the propylene-based polymer (X) and the propylene-based polymer (Y) In the case of an inorganic chemical foaming agent, for example, in the case of an inorganic chemical foaming agent, preferably 100 parts by weight of propylene polymer (X) It is selected in the range of 0.5 to 5 parts by weight. In this way, it is easy to obtain a foamed molded article having a foaming ratio of 2 times or more and uniform fine cells.

3. Other compounding agents The propylene-based resin composition used in the polypropylene-based injection-foamed molded article of the present invention has various additives usually used for polyolefins, such as nucleation, as necessary, as long as the object of the present invention is not impaired. An agent, an antioxidant, a neutralizing agent, a light stabilizer, an ultraviolet absorber, an inorganic filler, an antiblocking agent, a lubricant, an antistatic agent, a metal deactivator, and the like can be appropriately blended.

  Examples of antioxidants include phenolic antioxidants, phosphite antioxidants, and thio antioxidants, and examples of neutralizing agents include higher fatty acid salts such as calcium stearate and zinc stearate. Examples of the light stabilizer and the ultraviolet absorber include hindered amines, nickel complex compounds, benzotriazoles, and benzophenones.

As nucleating agents, sorbitols such as sodium 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphate, talc, 1,3,2,4-di (p-methylbenzylidene) sorbitol Compound, hydroxy-di (aluminum t-butylbenzoate, 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid and aliphatic monocarboxylic acid lithium salt having 8 to 20 carbon atoms (Asahi Examples include Denka Co., Ltd. product name NA21).
Examples of inorganic fillers and antiblocking agents include calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate, and examples of lubricants include higher fatty acid amides such as stearic acid amide. it can.
Furthermore, examples of the antistatic agent include fatty acid partial esters such as glycerin fatty acid monoester, and examples of the metal deactivator include triazines, phosphones, epoxies, triazoles, hydrazides, and oxamides. it can.

II. Method for Preparing Propylene Resin Composition As a method for preparing the propylene resin composition used in the present invention, the propylene polymer (X) in powder form or pellet form, the propylene polymer (Y), and A method of mixing other compounding agents appropriately blended by dry blend, Henschel mixer or the like can be mentioned.

III. Polypropylene Injection Foam Molded Article The polypropylene injection foam molded article of the present invention is formed by injection foam molding of the propylene resin composition, and the production method is based on the injection foam molding method. The injection foam molding method includes an injection step of injecting and filling the propylene resin composition into a mold cavity in a molten or semi-molten state, and a foaming step of foaming the propylene resin composition in the mold cavity. Preferably, a molten or semi-molten propylene resin composition in an amount less than the volume of the mold cavity is injected and filled into the mold cavity, and the cavity of the mold cavity is filled with the expansion pressure of the foaming agent. The mold cavity clearance (t 1) is smaller than the mold cavity clearance (t 1) corresponding to the shape position of the final product. a mold cavity having t 0) is injected and filled with the propylene-based resin composition in a molten state or a semi-molten state; Yabiti clearance (t 1) to retract the movable die to include mold opening injection molding process allowed to fill the void of the mold cavity by expansion pressure generated by the blowing agent.

IV. Use of polypropylene-based injection-foamed molded article The polypropylene-based injection-foamed molded article of the present invention can provide a foam-molded article having high rigidity, beautiful and excellent surface appearance. Applications of such molded products include: automotive interior parts such as instrument panels and door trims, air-conditioning cases, air cleaner cases, automotive heat-resistant parts such as lamps, automotive exterior parts such as bumpers and back doors, vanity tables, washstands, It can be suitably used for industrial parts such as toiletries such as toiletries.

  EXAMPLES 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, the physical properties of polypropylene-based injection-foamed molded articles or their constituent components were measured and evaluated according to the following evaluation methods, and the following resins were used.

1. Evaluation method (1) Melt flow rate (MFR) [unit: g / 10 min]:
The propylene-based polymer is JIS K7210: 1999, “Method A of plastic-thermoplastic plastic melt mass flow rate (MFR) and melt volume flow rate (MVR)”, condition M (230 ° C., 2.16 kg load). Measured according to

(2) Weight average molecular weight (Mw)
It was measured by the method described in the present specification by gel permeation chromatography (GPC).

(3) mm fraction It measured by the method as described in the said specification using JEOL Co., Ltd. make, GSX-400, and FT-NMR. The unit is%.

(4) Elongation viscosity It measured by the method as described in this specification using the rheometer.

(5) Melting temperature (Tm)
Measurements were made using a Seiko DSC.
After taking 5.0 mg of sample and holding it at 200 ° C. for 5 minutes, it is crystallized at a rate of temperature decrease of 10 ° C./min to 40 ° C. to erase its thermal history, and further melted at a rate of temperature increase of 10 ° C./min. The peak temperature of the melting curve is taken as the melting point. When a plurality of melting points are observed in the resin, the one observed at the highest temperature is taken as the melting point of the resin.

(6) Determination of ethylene content The ethylene content is measured by ¹³ C-NMR under the same conditions as in the mm fraction measurement described above. The ethylene content is calculated according to the analysis method described in Macromolecules 1982 1150.

(7) Molecular weight distribution:
Measurement was performed by the method described above.

(8) Temperature rise elution fractionation (TREF):
The TREF measurement method is as described above using the following apparatus.
(I) TREF part TREF column: 4.3 mmφ × 150 mm stainless steel column Column filler: 100 μm surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation Digital Program Controller KP1000 (Valve Oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C
Valve: 6-way valve 4-way valve (ii) Sample injection part Injection method: Loop injection method Injection amount: Loop size 0.1ml
Inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Iii) Detection unit Detector: Fixed wavelength infrared detector MIRAN 1A manufactured by FOXBORO
Detection wavelength: 3.42 μm
High-temperature flow cell: Micro flow cell for LC-IR Optical path length 1.5mm Window shape 2φ x 4mm oval Synthetic sapphire window Measurement temperature: 140 ° C
(Iv) Pump unit Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co. (v) Measurement conditions Solvent: o-dichlorobenzene (including 0.5 mg / ml BHT)
Sample concentration: 5 mg / ml
Sample injection volume: 0.1 ml
Solvent flow rate: 1 ml / min

(9) Foaming ratio: The maximum foaming ratio that can reproduce the shape of the cavity in a predetermined molding method was determined.
In the short shot method, the filling rate was changed, and the foaming ratio of the molded product obtained at the minimum filling rate at which the shape of the molded product could reproduce the cavity shape was used.
In the mold opening method, the mold opening amount was changed, and the foaming ratio of the molded product obtained when the mold was opened was the maximum mold opening amount that could reproduce the cavity shape.
The specific gravity (d _G , d _M ) of each test piece obtained by cutting from the gate part and the filling end part of the foam molded product was measured, and the average value (d _G-M ) and the specific gravity (d1) of the foam molded product material ) And (d ₁ / d _G−M ) = foaming ratio.

(10) Appearance of molded product: Judgment was made based on the following evaluation criteria visually.
○: Specular gloss, very small swirl mark △: Surface fogging, low swirl mark ×: No gloss, many swirl marks

2. Materials used (1) Propylene polymer (X)
The propylene polymers (PP-1) to (PP-5) produced in the following Production Examples 1 to 5 and a commercially available polypropylene resin (PF814) were used. Table 1 shows the properties of the propylene polymers (PP-1) to (PP-5) and the commercially available polypropylene resin (PF814).

[Production Example 1] (PP-1)
(1) [Synthesis of rac-dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride]:
Synthesis of (1-a) dimethylbis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) silane:
Synthesis was performed according to the method described in Example 1 of JP-A-2004-124044.

Synthesis of (1-b) rac-dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride:
In a 100 ml glass reaction vessel, 5.3 g (8.8 mmol) of dimethylbis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) silane and 150 ml of diethyl ether were added, and dry ice was added. -It cooled to -70 degreeC with the methanol bath. To this, 12 ml (18 mmol) of a 1.50 mol / liter n-butyllithium-hexane solution was added dropwise. After dropping, the temperature was returned to room temperature and stirred for 16 hours. The solvent of the reaction solution was concentrated under reduced pressure to about 20 ml, 200 ml of toluene was added, and the solution was cooled to −70 ° C. in a dry ice-methanol bath.
Thereto was added 2.8 g (8.7 mmol) of hafnium tetrachloride. Thereafter, the mixture was stirred for 3 days while gradually returning to room temperature.
The solvent was distilled off under reduced pressure, recrystallized from dichloromethane / hexane, and racemic dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride (purity 99% or more). ) Was obtained as yellow-orange crystals (2.9 g, yield 39%).

The resulting proton nuclear magnetic resonance method for racemate identified value according to ^{(1 H-NMR)} are shown below.
^[1 H-NMR (CDCl3) identification result]
Racemate: δ 1.12 (s, 6H), δ 2.42 (s, 6H), δ 6.06 (d, 2H), δ 6.24 (d, 2H), δ 6.78 (dd, 2H), δ 6. 97 (d, 2H), δ 6.96 (s, 2H), δ 7.25 to δ 7.64 (m, 12H).

(2) [Catalyst synthesis]:
(2-1) Chemical treatment of ion-exchanged layered silicate 96% sulfuric acid (1044 g) was added to 3456 g of distilled water in a separable flask, and then montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL: average particle size 19 μm) as a layered silicate. ) 600 g was added. The slurry was heated to 90 ° C. over 1 hour at 0.5 ° C./minute, and reacted at 90 ° C. for 120 minutes. The reaction slurry was cooled to room temperature in 1 hour, added with 2400 g of distilled water and then filtered to obtain 1230 g of a cake-like solid.
Next, 648 g of lithium sulfate and 1800 g of distilled water were added to the separable flask to make a lithium sulfate aqueous solution. The slurry was heated to 90 ° C. over 1 hour at 0.5 ° C./minute, and reacted at 90 ° C. for 120 minutes. The reaction slurry was cooled to room temperature in 1 hour, filtered after adding 1980 g of distilled water, further washed with distilled water to pH 3, and filtered to obtain 1150 g of cake-like solid.
The obtained solid was preliminarily dried at 130 ° C. for 2 days under a nitrogen stream, and then coarse particles of 53 μm or more were removed, and further, rotary kiln drying was performed under a condition of 215 ° C. under a nitrogen stream for a residence time of 10 minutes. 340 g was obtained.
The composition of this chemically treated smectite is Al: 7.81 wt%, Si: 36.63 wt%, Mg: 1.27 wt%, Fe: 1.82 wt%, Li: 0.20 wt%, Al / Si = 0.222 [mol / mol].

(2-2) Catalyst Preparation and Prepolymerization In a three-necked flask (volume: 1 L), 20 g of the chemically treated smectite obtained above was added, and heptane (114 ml) was added to form a slurry, to which triethylaluminum (50 mmol: 81 ml of a heptane solution having a concentration of 71 mg / ml) was added, and the mixture was stirred for 1 hour, washed with heptane to a residual liquid ratio of 1/100, and heptane was added so that the total volume became 200 ml.
In another flask (volume 200 ml), heptane (85 ml) was added to rac-dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride (0.3 mmol). Then, triisobutylaluminum (0.6 mmol: 0.85 ml of a heptane solution having a concentration of 140 mg / ml) was added and stirred at room temperature for 45 minutes for reaction. This solution was added to a 3 L flask containing chemically treated smectite and stirred at room temperature for 45 minutes. Thereafter, 214 ml of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 20 g / hour and prepolymerization was performed while maintaining the temperature at 40 ° C. for 2 hours. Thereafter, propylene feed was stopped, and residual polymerization was performed at 50 ° C. for 0.5 hour. After removing the supernatant of the obtained catalyst slurry by decantation, the prepolymerized catalyst was washed by adding decantation again with heptane. Triisobutylaluminum (12 mmol: 17 ml of a heptane solution having a concentration of 140 mg / ml) was added to the portion remaining after the decantation, and the mixture was stirred for 10 minutes. This solid was dried under reduced pressure for 2 hours to obtain 47.6 g of a dry prepolymerized catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 1.38.

(3) [Polymerization]
First step polymerization:
The 3 L autoclave was thoroughly dried beforehand by circulating nitrogen under heating, and then the interior of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 ml of a heptane solution of triisobutylaluminum (140 mg / ml) and introducing 48 g of ethylene and 750 g of liquid propylene, the temperature was raised to 70 ° C. Thereafter, 210 mg of the prepolymerized catalyst in a weight excluding the prepolymerized polymer was pumped to the polymerization tank with high-pressure argon to initiate polymerization. After maintaining at 70 ° C. for 1 hour, unreacted propylene was quickly purged, and the inside of the autoclave was purged with nitrogen to stop the polymerization in the first step.
7.5 g of the polymer after the first step was recovered from a nitrogen-substituted autoclave using a Teflon (registered trademark) tube and analyzed.

Second step polymerization:
After maintaining the above nitrogen-substituted autoclave at 50 ° C. and atmospheric pressure, 1.0 MPa, and then ethylene was quickly added to 1.0 MPa in partial pressure to start polymerization in the second step.
During the polymerization, a mixed gas of ethylene / propylene, which had been adjusted in advance so as to have a constant composition, was introduced to keep the total pressure at 2.0 MPa and maintained at 50 ° C.
The average gas composition of the polymerization in the second step was C2: 55.6%.
After 2 hours, the unreacted ethylene / propylene mixed gas was purged to terminate the polymerization to obtain 399 g of a polymer (PP-1).

[Production Example 2] (PP-2)
(1) [Polymerization]:
First step polymerization:
The 3 L autoclave was thoroughly dried in advance by circulating nitrogen under heating, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 ml of a heptane solution of triisobutylaluminum (140 mg / ml) and introducing 750 g of liquid propylene, the temperature was raised to 75 ° C.
Thereafter, 250 mg of the prepolymerized catalyst prepared in [Production Example 1] by weight excluding the prepolymerized polymer was pumped to the polymerization tank with high-pressure argon to initiate polymerization. After maintaining at 75 ° C. for 1 hour, unreacted propylene was quickly purged, and the inside of the autoclave was purged with nitrogen to stop the polymerization in the first step.
Using a Teflon (registered trademark) tube from the nitrogen-substituted autoclave, 24 g of the polymer after the first step was collected and analyzed.

Second step polymerization:
After maintaining the above nitrogen-substituted autoclave at 70 ° C. and atmospheric pressure, propylene was added at a partial pressure of 0.5 MPa, and ethylene was then added at a partial pressure of 1.5 MPa to start polymerization in the second step. During the polymerization, a mixed gas of ethylene / propylene, which had been adjusted in advance so as to have a constant composition, was introduced and maintained at a total pressure of 2.0 MPa and maintained at 70 ° C.
The average gas composition of the polymerization in the second step was C2: 80.1%. After 50 minutes, the unreacted ethylene / propylene mixed gas was purged to terminate the polymerization to obtain 174 g of a polymer (PP-2).
This sample was melt kneaded and evaluated for physical properties in the same manner as in Production Example M-1. The value of strain hardening degree λmax of this sample is 2.5, and it is considered that a copolymer having a branched structure is formed.

[Production Example 3] (PP-3)
(1) Synthesis of rac- (1,1′-dimethylsilylenebis (2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl)) hafnium dichloride rac-dichloro [1,1′-dimethylsilylenebis {2 -Methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium was synthesized according to the method described in Example 1 of JP-A-11-240909.

(2) catalyst preparation and prepolymerization,
In a three-necked flask (volume: 1 L), 10 g of the chemically treated smectite prepared in [Production Example 1] was added, and heptane (66 ml) was added to form a slurry. 34 ml) of the solution was added and the mixture was stirred for 1 hour, washed with heptane to a residual liquid ratio of 1/100, and heptane was added so that the total volume became 100 ml.
In a separate flask (volume 200 ml), rac-dimethylsilylenebis (2- (2- (5-methyl) -furyl) -4-phenyl-indenyl) hafnium dichloride (0 .135 mmol) was dissolved in toluene (38 ml). (Complex solution 1)
In another flask (volume 200 ml), rac- (1,1′-dimethylsilylenebis (2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl)) hafnium dichloride (0. 015 mmol) was dissolved in toluene (5 ml). (Complex solution 2)
To a 3 L flask containing chemically treated smectite, triisobutylaluminum (0.6 mmol: 0.85 ml of a heptane solution having a concentration of 140 mg / ml) was added, and the complex solution 1 was added, followed by addition of the complex solution 2. Stir at room temperature for 60 minutes. Thereafter, 356 ml of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed while maintaining the temperature at 40 ° C. for 2 hours. Thereafter, propylene feed was stopped, and residual polymerization was performed at 50 ° C. for 0.5 hour. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (12 mmol: 8.5 ml of a heptane solution having a concentration of 140 mg / ml) was added and stirred for 10 minutes. This solid was dried under reduced pressure for 2 hours to obtain 26.1 g of a dry prepolymerized catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 1.84.

(3) [Polymerization]
First step polymerization:
The 3 L autoclave was thoroughly dried in advance by circulating nitrogen under heating, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 ml of a heptane solution of triisobutylaluminum (140 mg / ml), 450 Nml of hydrogen and 750 g of liquid propylene were introduced, and the temperature was raised to 75 ° C.
Thereafter, 100 mg of the prepolymerized catalyst prepared as described above in a weight excluding the prepolymerized polymer was pumped to the polymerization tank with high-pressure argon to initiate polymerization. After maintaining at 75 ° C. for 1 hour, unreacted propylene was quickly purged, and the inside of the autoclave was purged with nitrogen to stop the polymerization in the first step.
Using a Teflon (registered trademark) tube from the nitrogen-substituted autoclave, 34 g of the polymer after the first step was collected and analyzed.

Second step polymerization:
After maintaining the above nitrogen-substituted autoclave at 50 ° C. and atmospheric pressure, propylene was added at a partial pressure of 0.5 MPa, and then ethylene was added at a partial pressure of 1.5 MPa to start polymerization in the second step. During the polymerization, a mixed gas of ethylene / propylene, which had been adjusted in advance so as to have a constant composition, was introduced to keep the total pressure at 2.0 MPa and maintained at 50 ° C. The average gas composition of the polymerization in the second step was C2: 80.1%. After 50 minutes, the unreacted ethylene / propylene mixed gas was purged to terminate the polymerization, and 386 g of a polymer (PP-3) was obtained.

[Production Example 4] (PP-4)
(1) [Polymerization]
First step polymerization:
The 3 L autoclave was thoroughly dried in advance by circulating nitrogen under heating, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 ml of a heptane solution of triisobutylaluminum (140 mg / ml) and introducing 300 Nml of hydrogen and 750 g of liquid propylene, the temperature was raised to 75 ° C.
Thereafter, 150 mg of the prepolymerized catalyst prepared in [Production Example 3] by weight excluding the prepolymerized polymer was pumped to the polymerization tank with high-pressure argon to initiate polymerization. After maintaining at 75 ° C. for 1 hour, unreacted propylene was quickly purged, and the inside of the autoclave was purged with nitrogen to stop the polymerization in the first step.
Using a Teflon (registered trademark) tube from the nitrogen-substituted autoclave, 22 g of the polymer after the first step was collected and analyzed.

Second step polymerization:
After maintaining the above nitrogen-substituted autoclave at 60 ° C. and atmospheric pressure, propylene was added at a partial pressure of 0.5 MPa, and then ethylene was added at a partial pressure of 1.5 MPa to start polymerization in the second step. During the polymerization, a mixed gas of ethylene / propylene, which had been adjusted in advance so as to have a constant composition, was introduced to maintain the total pressure at 2.0 MPa and maintained at 60 ° C.
The average gas composition of the polymerization in the second step was C2: 81.7%. After 50 minutes, the unreacted ethylene / propylene mixed gas was purged to stop the polymerization, thereby obtaining 330 g of a polymer (PP-4).

[Production Example 5] (PP-5)
(1) Catalyst preparation and prepolymerization In a three-necked flask (volume: 1 L), 10 g of the chemically treated smectite prepared in [Production Example 1] was added, and heptane (66 ml) was added to form a slurry, to which triisobutylaluminum ( 24 mmol: a heptane solution having a concentration of 140 mg / ml was added (34 ml), and the mixture was stirred for 1 hour, washed with heptane to a residual liquid ratio of 1/100, and heptane was added so that the total volume became 100 ml.
In another flask (volume 200 ml), (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- () synthesized according to the method described in JP-A-11-240909 was used. Toluene (43 ml) was added to 4-chlorophenyl) -4H-azulenyl}] hafnium (0.30 mmol) and stirred. Triisobutylaluminum (0.6 mmol: 0.85 ml of a heptane solution having a concentration of 140 mg / ml) was added to the 3 L flask containing the chemically treated smectite, and the complex solution was further added and stirred at room temperature for 60 minutes. Thereafter, 356 ml of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed while maintaining 40 ° C. for 2 hours. Thereafter, propylene feed was stopped, and residual polymerization was performed at 50 ° C. for 0.5 hour. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (12 mmol: 17 ml of a heptane solution having a concentration of 140 mg / ml) was added and stirred for 10 minutes. This solid was dried under reduced pressure for 2 hours to obtain 30.5 g of a dry prepolymerized catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 2.05.

(2) [Polymerization]
First step polymerization:
The 3 L autoclave was thoroughly dried in advance by circulating nitrogen under heating, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 ml of a heptane solution of triisobutylaluminum (140 mg / ml) and introducing 750 g of liquid propylene, the temperature was raised to 75 ° C.
Thereafter, 20 mg of the prepolymerized catalyst prepared as described above in a weight excluding the prepolymerized polymer was pumped to the polymerization tank with high-pressure argon to initiate polymerization. After maintaining at 70 ° C. for 1 hour, unreacted propylene was quickly purged, and the inside of the autoclave was purged with nitrogen to stop the polymerization in the first step.
Using a Teflon (registered trademark) tube from the nitrogen-substituted autoclave, 14 g of the polymer after the first step was collected and analyzed.

Second step polymerization:
After maintaining the above nitrogen-substituted autoclave at 70 ° C. and atmospheric pressure, propylene was added at a partial pressure of 0.5 MPa, and ethylene was then added at a partial pressure of 1.5 MPa to start polymerization in the second step. During the polymerization, a mixed gas of ethylene / propylene, which had been adjusted in advance so as to have a constant composition, was introduced and maintained at a total pressure of 2.0 MPa and maintained at 70 ° C.
The average gas composition of the polymerization in the second step was C2: 83.2%. After 50 minutes, the unreacted ethylene / propylene mixed gas was purged to stop the polymerization to obtain 291 g of a polymer (PP-5).
This sample was melt-kneaded in the same manner as in Production Example 1 to evaluate the physical properties. The elongational viscosity of this sample does not show strain hardening, that is, the value of the strain hardening degree λmax is 1.0, and it is considered that no graft copolymer is formed.

(Commercial item)
PF814 (electron beam irradiated product):
High melt tension polypropylene (MFR = 2.5 g / 10 min) manufactured by Basel Co. was used.

[Example 1]
Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propione, which is a phenolic antioxidant, with respect to 100 parts by weight of the propylene polymer (PP-1). -To] methane (trade name: IRGANOX 1010, manufactured by Ciba Specialty Chemicals) 0.05 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: phosphite antioxidant) IRGAFOS 168, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.05 parts by weight, and calcium stearate as a neutralizing agent (trade name: calcium stearate, manufactured by Nippon Oil & Fats Co., Ltd.) 0.05 part by weight Mix for 3 minutes at room temperature with a stirrer mixer (Henschel mixer, trade name), then melt knead with an extruder to obtain pellets It was.

A PP-1 pellet obtained by blending 5 parts by weight of a chemical foaming agent 30% master batch (Polyslen EE275F manufactured by Eiwa Kasei Co., Ltd., cracked gas amount 40 ml / g) with a heating cylinder having a screw diameter of 50 mm and a mold clamping control mechanism. Using an injection molding machine with a maximum clamping force of 300 tons, the temperature of each heating zone of the heating cylinder is set to 230 ° C, 230 ° C, 230 ° C, 210 ° C, and 180 ° C in order from the front end to the rear. In a cavity having a back pressure of 9.8 MPa, a mold cooling water temperature of 40 ° C., a distance between the movable mold and the fixed mold of 2.0 mm, and a volume of 160 cm ³ , 160 cm ³ of the material for the foamed molded body heated and melted is 160 cm ^{3. 3} was injection filled. The primary cooling was performed for 1 second after completion of the injection, and then the movable mold was retracted to expand the cavity volume and foam. Thereafter, secondary cooling was carried out for 20 seconds to obtain a polypropylene injection foam molded article.
Table 2 shows the evaluation results of the obtained polypropylene injection foam molding.
The polypropylene-based injection-foamed molded article satisfying the configuration of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 2]
It implemented similarly to Example 1 except having used the propylene polymer (PP-2) instead of the propylene polymer (PP-1), and obtained the polypropylene injection foaming molding.
Table 2 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article satisfying the configuration of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 3]
It implemented similarly to Example 1 except having used the propylene polymer (PP-3) instead of the propylene polymer (PP-1), and obtained the polypropylene injection foaming molding.
Table 2 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article satisfying the configuration of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 4]
It implemented similarly to Example 1 except having used the propylene polymer (PP-4) instead of the propylene polymer (PP-1), and obtained the polypropylene injection foaming molding.
Table 2 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article satisfying the configuration of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 5]
A PP-1 pellet used in Example 1 blended with 5 parts by weight of a chemical foaming agent 30% master batch (Polyslen EE275F manufactured by Eiwa Kasei Co., Ltd., cracked gas amount 40 ml / g), a heating cylinder having a screw diameter of 50 mm and mold clamping Using an injection molding machine having a control mechanism and a maximum clamping force of 300 tons, the temperature of each heating zone of the heating cylinder is changed from 230 ° C., 230 ° C., 230 ° C., 210 ° C., and 180 ° in order from the front end portion to the rear portion. The molded foam was melted by heating in a cavity having a back pressure of 9.8 MPa, a mold cooling water temperature of 40 ° C., a distance between the moving mold and the fixed mold of 2.0 mm, and a volume of 160 cm ^3. 80 cm ³ of the material for use was injected and filled, and the void was filled with the expansion pressure of the foaming resin itself to obtain a polypropylene injection foamed molded article.
Table 2 shows the evaluation results of the obtained polypropylene injection foam molding.
The polypropylene injection-foamed molded article satisfying the constitution of the present invention had uniform air bubbles and good appearance of the molded product.

[Example 6]
A propylene polymer (PP-1) was injected into a resin melted at 210 ° C. using an electric injection molding machine 850T manufactured by Ube Industries, and 0.5 parts by weight of carbon dioxide in a supercritical state was injected at an injection pressure of 6 MPa. The mold is injected at a back pressure of 7 MPa. The mold was injection-filled with 160 cm ³ of a foamed molded material, which was heated and melted, in a cavity having a cooling water temperature of 40 ° C., a distance between the moving mold and the fixed mold of 2.0 mm, and a volume of 160 cm ³ . The primary cooling was performed for 1 second after completion of the injection, and then the movable mold was retracted to expand the cavity volume and foam. Thereafter, secondary cooling was carried out for 20 seconds to obtain a polypropylene injection foam molded article.
Table 2 shows the evaluation results of the obtained polypropylene injection foam molding.
The polypropylene injection foam molded article satisfying the constitution of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 7]
A propylene-based polymer (PP-1) is injected into a resin in which a supercritical carbon dioxide gas fluid is completely melted by amotech method using an electric injection molding machine 850T manufactured by Ube Machinery Co., Ltd. 0.5 parts by weight were injected at a mold cooling water temperature of 40 ° C. under the condition of a back pressure of 7 MPa, the distance between the movable mold and the stationary mold was 2.0 mm, and the volume was 160 cm ³ . 80 cm ^{3 of the} foam molding material was injected and filled, and the void was filled with the expansion pressure of the foaming resin itself to obtain a polypropylene injection foam molding.
Table 2 shows the evaluation results of the obtained polypropylene injection foam molding.
The polypropylene injection-foamed molded article satisfying the constitution of the present invention had uniform air bubbles and good appearance of the molded product.

[Comparative Example 1]
The same procedure as in Example 1 was carried out except that a propylene polymer (PF814) different from the propylene polymer specified in the present invention was used in place of the propylene polymer (PP-1). A foamed molded product was obtained.
Table 3 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article that does not satisfy the configuration of the present invention had a poor foam appearance although the foaming ratio was high.

[Comparative Example 2]
The same procedure as in Example 6 was carried out except that a propylene polymer (PF814) different from the propylene polymer specified in the present invention was used in place of the propylene polymer (PP-1). A foamed molded product was obtained.
Table 3 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article that does not satisfy the configuration of the present invention had a poor foam appearance although the foaming ratio was high.

[Comparative Example 3]
In the same manner as in Example 1 except that a propylene polymer (PP-5) different from the propylene polymer specified in the present invention was used instead of the propylene polymer (PP-1), polypropylene was used. A system injection foam molded article was obtained.
Table 3 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article that does not satisfy the constitution of the present invention had large and non-uniform bubbles, and the appearance of the molded product was cloudy and a swirl mark was observed.

[Comparative Example 4]
In place of the propylene polymer (PP-1), the same procedure as in Example 6 was carried out except that a propylene polymer (PP-5) different from the propylene polymer specified in the present invention was used. A system injection foam molded article was obtained.
Table 3 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article that did not satisfy the constitution of the present invention had a low expansion ratio and the appearance of the molded product was cloudy on the surface, and swirl marks were observed.

[Comparative Example 5]
In the same manner as in Example 7 except that a propylene polymer (PP-5) different from the propylene polymer specified in the present invention was used instead of the propylene polymer (PP-1), polypropylene was used. A system injection foam molded article was obtained.
Table 3 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.
The polypropylene-based injection-foamed molded article that does not satisfy the constitution of the present invention has foams with extremely uneven cell coalescence, and the appearance of the molded product has no gloss.

[Example 8]
For 100 parts by weight of a propylene-based resin component consisting of 60% by weight of a propylene-based polymer (PP-1) and 40% by weight of a commercially available propylene ethylene block copolymer (Japan Polypro BC04G, Mw185000, λmax = 1.0) , A tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, a phenolic antioxidant (trade name: IRGANOX 1010, Ciba Specialty Chemicals) 0.05 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.05 which is a phosphite antioxidant Parts by weight, and calcium stearate as a neutralizing agent (trade name: calcium stearate (Manufactured by Nippon Oil & Fats Co., Ltd.) 0.05 parts by weight, mixed with a high-speed stirring mixer (Henschel mixer, trade name) for 3 minutes at room temperature, and then melt-kneaded with an extruder to obtain pellets It was.

The resulting pellet blended with 5 parts by weight of a chemical foaming agent 30% masterbatch (Polyslen EE275F manufactured by Eiwa Kasei Co., Ltd., cracked gas amount 40 ml / g) is a maximum with a heating cylinder with a screw diameter of 50 mm and a mold clamping control mechanism. Using an injection molding machine with a clamping force of 300 tons, the temperature of each heating zone of the heating cylinder is set to 230 ° C., 230 ° C., 230 ° C., 210 ° C., and 180 ° C. in order from the tip to the back. the pressure and 9.8 MPa, injection in the mold cooling water temperature 40 ° C., in the cavity space of the mobile and the fixed type and the volume at 2.0mm is 160cm ^3, the foamed molded body material 160cm ³ were heated and melted Filled. The primary cooling was performed for 1 second after completion of the injection, and then the movable mold was retracted to expand the cavity volume and foam. Thereafter, secondary cooling was carried out for 20 seconds to obtain a polypropylene injection foam molded article.
Table 4 shows the evaluation results of the obtained polypropylene injection foam molding.
The polypropylene-based injection-foamed molded article satisfying the configuration of the present invention had uniform foam, good appearance of the molded product, and a high expansion ratio.

[Example 9]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 30% by weight of a propylene polymer (PP-1) and 70% by weight of a commercially available propylene ethylene block copolymer (BC04G). An injection foam molding was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Example 10]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 10% by weight of the propylene polymer (PP-1) and 90% by weight of the commercially available propylene ethylene block copolymer (BC04G). An injection foam molding was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Example 11]
Except that the propylene resin component was changed to 60% by weight of a propylene polymer (PP-1) and 40% by weight of a commercially available propylene homopolymer (MA1B, Mw 216000, λmax = 1.0 manufactured by Nippon Polypro Co., Ltd.) In the same manner as in No. 8, a polypropylene-based injection foamed molded article was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Example 12]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 30% by weight of the propylene polymer (PP-1) and 70% by weight of the commercially available propylene homopolymer (MA1B). A molded body was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Example 13]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 10% by weight of the propylene polymer (PP-1) and 90% by weight of the commercially available propylene homopolymer (MA1B). A molded body was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Comparative Example 6]
The same procedure as in Example 8 was conducted, except that the propylene resin component was changed to 100% by weight of a commercially available propylene ethylene block copolymer (BC04G), to obtain a polypropylene injection foam molded article.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Comparative Example 7]
The same procedure as in Example 8 was conducted, except that the propylene resin component was changed to 100% by weight of a commercially available propylene homopolymer (MA1B) to obtain a polypropylene injection foam molded article.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Comparative Example 8]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 60% by weight of a propylene polymer (PF814) and 40% by weight of a commercially available propylene ethylene block copolymer (BC04G). A molded body was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

[Comparative Example 9]
The same procedure as in Example 8 was conducted except that the propylene resin component was changed to 30% by weight of a propylene polymer (PF814) and 70% by weight of a commercially available propylene ethylene block copolymer (BC04G). A molded body was obtained.
Table 4 shows the evaluation results of the obtained polypropylene-based injection-foamed molded article.

式中、ＰＰ系（Ｘ）はプロピレン系重合体（Ｘ）を、ＰＰ系（Ｙ）はプロピレン系重合体（Ｙ）をそれぞれ意味する。

In the formula, PP-based (X) means propylene-based polymer (X), and PP-based (Y) means propylene-based polymer (Y).

  A molded product not containing the propylene polymer (X) could not obtain a sufficient expansion ratio (Comparative Examples 6 and 7). When 10% by weight of the propylene polymer (X) is formulated, the expansion ratio is remarkably improved, and about 70% of the expansion ratio in the 100% by weight product of the propylene polymer (X) (Example 1) can be achieved (Examples). 10, 13). On the other hand, when a commercially available high melt tension PP was formulated, the foaming ratio was significantly improved, but the appearance deteriorated (Comparative Examples 8 and 9).

  The polypropylene-based injection-foamed molded article of the present invention has good injection-foaming moldability, is excellent in foaming and bubble uniformity, surface appearance, and can be significantly reduced in weight at a high foaming ratio. Automotive interior parts such as door trims, air-conditioner cases, air cleaner cases, automotive heat-resistant parts such as lamps, automotive exterior parts such as bumpers and back doors, industrial parts such as toiletries, washstands and toiletries It is extremely useful for such applications.

Claims (12)

Component (A) that is insoluble in p-xylene at 25 ° C. that satisfies the following requirements (A1) to (A5) and component that is soluble in p-xylene at 25 ° C. that satisfies the following requirements (B1) to (B3) (B The propylene polymer (X) having a weight average molecular weight of 50,000 to 800,000 and a propylene polymer (X) satisfying the following requirements (i) to (iii): Injection-molding a propylene-based resin composition containing 0.05 to 10 parts by weight of a foaming agent with respect to 100 parts by weight of a propylene-based resin component consisting of 0 to 94% by weight of a propylene-based polymer (Y) different from A polypropylene-based injection-foamed molded article characterized by comprising:
(A1) 20 to 95% by weight based on the total amount of the propylene-based polymer (X),
(A2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(A3) The isotactic triad fraction (mm) measured by 13C-NMR is 93% or more.
(A4) The strain hardening degree (λmax) in the measurement of elongational viscosity is 2.0 or more.
(A5) A propylene unit and an ethylene unit or an α-olefin unit are contained.
(B1) 5 to 80% by weight based on the total amount of the propylene polymer (X),
(B2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(B3) Contains propylene units, ethylene units and / or α-olefin units.
(I) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(Ii) The component insoluble in hot p-xylene is 0.3% by weight or less,
(Iii) The strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more.   The polypropylene-based injection foam molding according to claim 1, wherein the propylene-based resin component comprises 10 to 70% by weight of the propylene-based polymer (X) and 30 to 90% by weight of the propylene-based polymer (Y). body. Component (A) that is insoluble in p-xylene at 25 ° C. that satisfies the following requirements (A1) to (A5) and component that is soluble in p-xylene at 25 ° C. that satisfies the following requirements (B1) to (B3) (B And a propylene-based resin composition in which 0.05 to 10 parts by weight of a foaming agent is blended with 100 parts by weight of the propylene-based polymer (X) satisfying the following requirements (i) to (iii): A polypropylene-based injection-foamed molded article obtained by injection-molding.
(A1) 20 to 95% by weight based on the total amount of the propylene-based polymer (X),
(A2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(A3) The isotactic triad fraction (mm) measured by 13C-NMR is 93% or more.
(A4) The strain hardening degree (λmax) in the measurement of elongational viscosity is 2.0 or more.
(A5) A propylene unit and an ethylene unit or an α-olefin unit are contained.
(B1) 5 to 80% by weight based on the total amount of the propylene polymer (X),
(B2) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(B3) Contains propylene units, ethylene units and / or α-olefin units.
(I) The weight average molecular weight (Mw) measured by GPC is 100,000 to 1,000,000.
(Ii) The component insoluble in hot p-xylene is 0.3% by weight or less,
(Iii) The strain hardening degree (λmax) in the measurement of elongational viscosity is 1.1 or more.   The component (B) in the propylene-based polymer (X) further has a strain hardening degree (λmax) of 2.0 or more in the measurement of (B4) elongational viscosity. 2. A polypropylene-based injection-foamed molded article according to item 1.   The propylene polymer (X) is composed of a polymer having a branched structure having a crystalline propylene polymer segment as a side chain and an amorphous propylene copolymer segment as a main chain. The polypropylene-based injection-foamed molded article according to any one of -4.   Component (A) in the propylene polymer (X) is composed of a polymer having a branched structure in which a crystalline propylene polymer segment is a side chain and an amorphous propylene copolymer segment is a main chain. The polypropylene-based injection-foamed molded article according to any one of claims 1 to 5.   The component (A) in the propylene polymer (X) contains an ethylene unit and has an ethylene content of 0.1 to 10% by weight. The polypropylene-based injection-foamed molded article according to 1.   The component (B) in the propylene-based polymer (X) contains an ethylene unit and has an ethylene content of 10 to 60% by weight, according to any one of claims 1 to 7. Polypropylene injection foam moldings.   The polypropylene-based injection-foamed molded article according to any one of claims 1 to 8, wherein the foaming agent is at least one selected from a chemical foaming agent and a physical foaming agent. A method for producing the polypropylene-based injection foam molding according to any one of claims 1 to 9 by an injection foam molding method,
An injection step of injecting and filling the propylene-based resin composition into a mold cavity in a molten state or a semi-molten state; and a foaming step of foaming the propylene-based resin composition in the mold cavity. A method for producing a polypropylene-based injection-foamed molded article.   The injection foam molding method includes an injection step of injecting and filling a mold cavity with a molten or semi-molten propylene resin composition in an amount less than the volume of the mold cavity, and an expansion pressure by a foaming agent. The method for producing a polypropylene-based injection-foamed molded article according to claim 10, wherein the method is a short shot method comprising a foaming step of filling the voids.   In the injection foam molding method, the mold is composed of a fixed mold and a movable mold capable of moving forward and backward, and a mold cavity clearance smaller than the mold cavity clearance (t 1) corresponding to the shape position of the final product. An injection step of injecting and filling a molten or semi-molten propylene resin composition into a mold cavity having a clearance (t 0), and retracting the movable mold to the mold cavity clearance (t 1), and using a foaming agent The method for producing a polypropylene-based injection-foamed molded article according to claim 10, which is a mold opening injection molding method comprising a foaming step of filling a cavity of a mold cavity with an expansion pressure.

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