JP2015010102A - Injection-foamed molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection-foamed molding which has light weight and high rigidity, is uniform in cell shape and cell density, and has excellent external appearance.SOLUTION: The injection-foamed molding is obtained by adding a foaming agent to a propylene-based resin composition, which contains 60-99 pts. wt. of a propylene-based block copolymer (A) satisfying specific required items (a1)-(a5) simultaneously and 1-40 pts. wt. of an ethylene-based polymer (B) satisfying specific required items (b1)-(b5) simultaneously (on condition that the total of (A) and (B) is 100 pts. wt.), and injection-foaming the foaming agent-added propylene-based resin composition.

Description

  The present invention relates to an injection foam molded article obtained by injection foaming a specific propylene resin composition.

  Propylene polymers have a low specific gravity and are excellent in moldability and recyclability, so they are used in various fields such as household goods, kitchenware, packaging films, home appliances, machine parts, electrical parts, and automobile parts. It's being used. As for automotive parts, the proportion of propylene-based resin composition containing propylene-based polymer tends to increase with the increase in the safety, comfort and comfort of automobiles, and the increase in IT equipment. Is growing. In particular, a foamed molded article made of a propylene-based resin composition is suitably used for automobile parts because of its light weight and excellent molding appearance. For example, Patent Document 1 discloses a propylene block-based block copolymer. A foamed molded article comprising a propylene-based resin composition is disclosed.

  Here, in recent years, against the background of energy saving, the number of applicable hybrid vehicles and electric vehicles has increased. However, the travel distance of these vehicles is limited due to the battery capacity. Therefore, it is considered that the cruising distance can be extended if the power consumption of hybrid vehicles and electric vehicles is reduced. For example, it is proposed to reduce the power consumption of air conditioners by applying heat insulating materials to automobile interior parts. (Non-Patent Document 1). Conventionally, it has been considered to use a foamed molded article made of a propylene-based resin composition as a heat insulating material, but it is necessary to impart further heat insulating properties to improve the navigation distance of an electric vehicle. In order to improve the heat insulating property of the foamed molded product, it is conceivable to increase the expansion ratio or to reduce the size of the expanded cell. To that end, techniques for increasing the melt tension of the propylene-based resin composition are being studied.

  As a technique for increasing the melt tension of a propylene-based resin composition, for example, Patent Document 1 discloses a propylene-based resin composition containing an ultrahigh molecular weight propylene polymer having an intrinsic viscosity [η] of 8 to 13 dl / g. However, when the propylene-based polymer described in Patent Document 1 is added as a modifier to a propylene-based resin-modified material, it is difficult to achieve both high melt tension and injection molding fluidity, and large injection foam molding There was a problem that it was difficult to apply to the body.

  In Patent Document 2, a propylene resin comprising a polypropylene resin and a polyethylene resin and a thermoplastic resin obtained by copolymerizing ethylene, a macromonomer, and optionally an α-olefin having 3 or more carbon atoms. A composition is disclosed. However, when the composition is applied to an injection-foamed molded article, there are problems in terms of increasing the expansion ratio and reducing the cell size.

Japanese Patent No. 4083820 JP2013-1826A

Polyfile, 2011. January issue (Vol.48, No.563), P13, Taiseisha

An object of the present invention is to provide an injection foam molded article that is lightweight and highly rigid, has a uniform cell shape and cell density, and has a good appearance.
Another object of the present invention is to provide a propylene-based resin composition that is suitable for production of the molded article, has high melt tension, and has good injection molding fluidity.

  As a result of intensive studies, the present inventors have found that a propylene block copolymer (A) having a specific molecular structure and a propylene containing a specific amount of an ethylene polymer (B) having a specific molecular structure and melting characteristics. The resin-based resin composition expresses a specific high melt tension behavior, which is presumed to be derived from the mechanism of M1 to M4, and the propylene-based resin composition is further excellent in injection molding fluidity and injection foaming characteristics. I found out. An injection foam molded article obtained by adding a foaming agent to the propylene resin composition and performing injection foaming is lightweight and highly rigid, has a uniform cell shape and cell density, and has a good appearance. The headline and the present invention were completed.

  M1: A part soluble in n-decane at 23 ° C. in the propylene-based block copolymer (A): a polymer chain of Dsol (propylene / α-olefin copolymer rubber as a main component) and a specific molecule The polymer chain of the ethylene-based polymer (B) having a structure and melting characteristics forms an entanglement.

  M2: In the propylene-based resin composition, the propylene / α-olefin copolymer rubber and the ethylene-based polymer having a specific molecular structure and melting characteristics form a domain structure. The olefin copolymer rubber is compatible with a portion unnecessary for n-decane at 23 ° C .: Dsol (a crystalline propylene-based (co) polymer as a main component).

  M3: When the interparticle distance between domains consisting of propylene / α-olefin copolymer rubber and an ethylene polymer having a specific molecular structure and melting characteristics falls below a certain threshold value, in the molten propylene resin composition Forms an entangled structure derived from a long-chain branched structure and expresses high melt tension.

  M4: From the viewpoint of shortening the distance between the domain particles, it is optimal for the content of the skeleton derived from propylene in the portion (Dsol) soluble in n-decane at 23 ° C. in the propylene-based block copolymer. It is presumed that there is a range and that the intrinsic viscosity [η] measured in decalin at 135 ° C. of Dsol is preferably small.

  That is, the injection-foamed molded article of the present invention comprises 60 to 99 parts by weight of a propylene-based block copolymer (A) that simultaneously satisfies the following requirements (a1) to (a5), and the following requirements (b1) to (b5). Is added to a propylene-based resin composition containing 1 to 40 parts by weight of an ethylene polymer (B) satisfying the above (the total of (A) and (B) is 100 parts by weight). It is characterized by.

[Propylene block copolymer (A)]
(A1) 5 to 40% by weight of n-decane soluble part (Dsol) at 23 ° C. and 60 to 95% by weight of n-decane insoluble part (Dinsol) at 23 ° C. (however, Dsol And the total amount of Dinsol is 100% by weight).

(A2) The content of the skeleton derived from propylene in Dsol is 50 mol% or more and 80 mol% or less.
(A3) The intrinsic viscosity [η] of Dsol measured in decalin at 135 ° C. is 1.0 dl / g or more and 4.0 dl / g or less.

(A4) The pentad fraction (mmmm) of Dinsol is 93% or more.
(A5) The melt flow rate (MFR, 230 ° C., 2.16 kg load) of the propylene-based block copolymer (A) obtained in accordance with ASTM D1238E is 20 to 200 g / 10 min.

[Ethylene polymer (B)]
(B1) The melt flow rate (MFR, 190 ° C., 2.16 kg load) obtained in accordance with ASTM D1238-89 is 0.1 g / 10 min or more and 30 g / 10 min or less.

(B2) density of 875kg / m ³ or more 945 kg / m ³ or less.
(B3) Sum of the number of methyl branches per 1000 carbon atoms [Me (/ 1000 C)] and the number of ethyl branches [Et (/ 1000 C)] measured by ¹³ C-NMR [(Me + Et) (/ 1000 C)] Is 1.80 or less.

(B4) The ratio (η ₀ ) of zero shear viscosity [η ₀ (P)] at 200 ° C. to the 6.8th power (Mw ^6.8 ) of the weight average molecular weight measured by the GPC-viscosity detector method (GPC-VISCO). / Mw ^6.8 ) is 0.03 × 10 ⁻³⁰ or more and 7.5 × 10 ⁻³⁰ or less.

(B5) Intrinsic viscosity [[η] (dl / g)] measured in decalin at 135 ° C. and 0.776 of the weight average molecular weight measured by GPC-viscosity detector method (GPC-VISCO) (Mw ^0.776 ) ([η] / Mw ^0.776 ) is 0.90 × 10 ⁻⁴ or more and 1.65 × 10 ⁻⁴ or less.

  In addition, the injection-foamed molded article of the present invention is a content Ws (weight) of a portion (Dsol) soluble in n-decane at 23 ° C. in the propylene-based block copolymer (A) in the propylene-based resin composition. Part) and the content Wb (parts by weight) of the ethylene polymer (B) in the propylene resin composition (Wb / (Wb + Ws)) is 0.15 or more and 0.85 or less. Preferably there is.

  The injection-foamed molded article of the present invention is obtained by injection-foaming a propylene-based resin composition containing 0.1 to 30 parts by weight of filler (C) with respect to 100 parts by weight of the propylene-based resin composition. It is preferable.

The injection-foamed molded article of the present invention is lightweight and highly rigid, has a uniform cell shape and cell density, and has a good appearance.
Moreover, since the propylene-type resin composition which concerns on this invention has high melt tension and is excellent in injection molding fluidity | liquidity, this composition can be used suitably as a material for injection foam molding.

FIG. 1 shows a schematic diagram of a movable structure in an initial position in a cavity structure composed of a fixed mold and a movable mold. FIG. 2 is a schematic diagram in which the cavity volume is enlarged in a cavity structure composed of a fixed mold and a movable mold. FIG. 3 is a stereomicrograph of the cross section of the injection-foamed molded article obtained in Example 1. 4 is a stereomicrograph of the cross section of the injection-foamed molded article obtained in Comparative Example 1. FIG.

Hereinafter, the propylene-based resin composition according to the present invention and the injection-foamed molded article of the present invention will be specifically described.
[Propylene-based resin composition]
[Propylene block copolymer (A)]
The propylene-based block copolymer (A) according to the present invention satisfies the following requirements (a1) to (a5).

  (A1) Consists of 5% by weight or more and 40% by weight or less of n-decane soluble part (Dsol) at 23 ° C. and 60% by weight or more and 95% by weight or less of n-decane insoluble part (Dinsol) at 23 ° C. (However, the total amount of Dsol and Dinsol is 100% by weight). Preferably, Dsol is 7 wt% or more and 35 wt% or less, Dinsol is 65 wt% or more and 93 wt% or less, more preferably Dsol is 10 wt% or more and 30 wt% or less, and Dinsol is 70 wt% or more and 90 wt% or less. % Or less. If the Dsol is less than 5% by weight, the dispersibility of the ethylene polymer (B) in the propylene resin composition may be lowered, and the melt tension of the propylene resin composition may be lowered. Moreover, when there is more Dsol than 40 weight%, the rigidity of a propylene-type resin composition will fall and the application as an injection foaming molded part may become difficult. Moreover, the rigidity of the obtained injection foaming molding is also low.

  In the present invention, the portion (Dsol) soluble in n-decane at 23 ° C. is composed of propylene as a main component (greater than 50% by weight, preferably 80 to 100% by weight, more preferably 90 to 100% by weight). And propylene-based copolymer rubber composed of one or more olefins selected from ethylene and α-olefins having 4 to 20 carbon atoms.

  The portion insoluble in n-decane (Dinsol) at 23 ° C. is a main component (greater than 50% by weight, preferably 80 to 100% by weight, more preferably 90 to 100% by weight) as a crystalline propylene (co) Including polymers. The crystalline propylene-based (co) polymer contains 1.5 mol% or less of a crystalline propylene homopolymer or one or more olefins selected from propylene and ethylene and an α-olefin having 4 to 20 carbon atoms. A crystalline propylene copolymer is shown.

  In the present invention, “parts soluble in n-decane at 23 ° C. (Dsol)”, as described in detail in Examples below, are 150 ° C. in n-decane among propylene-based block copolymers. The part melt | dissolved in the n-decane solution side after temperature-falling to 23 degreeC after heat-dissolving for 2 hours is shown.

  The propylene-based block copolymer of the present invention is composed of a skeleton attributed to one or more olefins selected from ethylene and an α-olefin having 4 to 20 carbon atoms, with the skeleton attributed to propylene as an essential skeleton. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, -Hexadecene, 1-octadecene, 1-eicosene, etc. are mentioned. As the olefin constituting the skeleton resulting from one or more olefins selected from ethylene and an α-olefin having 4 to 20 carbon atoms in the copolymer, ethylene or an α-olefin having 4 to 10 carbon atoms is preferable. More preferably, they are ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene, and it is more preferable to use one or more.

  (A2) The content of the skeleton derived from propylene in Dsol is 50 mol% to 80 mol%, preferably 53 mol% to 77 mol%, and more preferably 55 mol% to 75 mol%. When the propylene content is out of the above range, the dispersibility of the ethylene polymer (B) in the propylene resin composition is lowered, and the melt tension of the propylene resin composition is lowered.

  (A3) The intrinsic viscosity [η] of Dsol measured in decalin at 135 ° C. is 1.0 dl / g or more and 4.0 dl / g or less, preferably 1.5 dl / g or more and 4.0 dl / g or less, more preferably Is 1.7 dl / g or more and 4.0 dl / g or less, more preferably 2.0 dl / g or more and 4.0 dl / g or less. If the intrinsic viscosity [η] of Dsol is lower than the above lower limit value, the impact resistance of the injection-foamed molded article is lowered, which is not preferable. Further, if the intrinsic viscosity [η] of Dsol is higher than the above upper limit, the dispersibility of the ethylene polymer (B) in the propylene resin composition is lowered, and the melt tension of the propylene resin composition is lowered. In the injection foam molded article, it is difficult to make the cells finer, which is not preferable.

  (A4) The pentad fraction (mmmm) of Dinsol is 93% or more, preferably 94% or more, and more preferably 95% or more. The upper limit of the pentad fraction is 100%, preferably 99.8%, more preferably 99.5%. If the pentad fraction is less than 93%, the rigidity of the injection-foamed molded product is lowered, which is not preferable.

  (A5) The melt flow rate (MFR) at 2.16 kg load at 230 ° C. obtained in accordance with ASTM D1238E is 20 g / 10 min or more and 200 g / 10 min or less. The lower limit is preferably 20 g / 10 minutes, more preferably 25 g / 10 minutes, and the upper limit is preferably 180 g / 10 minutes, more preferably 150 g / 10 minutes. When the melt flow rate (MFR) is equal to or higher than the lower limit, the injection molding fluidity is good, and the melt flow rate (MFR) can be suitably used for a large injection foam molded article. When the melt flow rate (MFR) is not more than the above upper limit value, the mechanical strength of the injection-foamed molded article is good.

(Producing method of propylene-based block copolymer (A))
In the production method of the propylene-based block copolymer (A), the following two steps ([step i] and [step ii]) are continuously performed in the presence of a known Ziegler-Natta catalyst or metallocene catalyst. Is the method.

  Examples of the Ziegler-Natta catalyst or the metallocene catalyst include JP2003-026719A, JP2005-187550A, JP2007-119514A, JP2007-106939A, WO2010 / 032793, WO00. / 63261, WO2001 / 027124 and the like can be referred to.

  [Step i] is a step of copolymerizing propylene homopolymerization or, if necessary, ethylene and propylene at a polymerization temperature of 0 to 100 ° C. and a polymerization pressure of normal pressure to 5 MPa gauge pressure. In [Step i], propylene homopolymerization is performed, or the amount of ethylene fed to propylene is made small so that the propylene-based (co) polymer produced in [Step i] becomes the main component of Dinsol. Can be adjusted.

  [Step ii] is a step of copolymerizing propylene and ethylene at a polymerization temperature of 0 to 100 ° C. and a polymerization pressure of normal pressure to 5 MPa gauge pressure. In [Step ii], the propylene-ethylene copolymer produced in [Step ii] is adjusted to be the main component of Dsol by increasing the amount of ethylene fed to propylene than in [Step i]. can do.

In [Step ii], the ethylene content in Dsol can be controlled by controlling the amount of ethylene fed to propylene in the polymerization system. .
After completion of the polymerization, a propylene block polymer (B) is obtained as a powder by performing post-treatment steps such as a known catalyst deactivation treatment step, a catalyst residue removal step, and a drying step as necessary.

[Ethylene polymer (B)]
The ethylene polymer (B) according to the present invention is a copolymer of ethylene and at least one α-olefin having 4 to 10 carbon atoms, preferably ethylene and an α-olefin having 6 to 10 carbon atoms. It is a coalescence. When an α-olefin having 4 carbon atoms is used, an α-olefin having 6 to 10 carbon atoms is also preferably used. Examples of the α-olefin having 4 to 10 carbon atoms include 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene and 1-decene.

The ethylene polymer (B) has the characteristics shown in the following requirements (b1) to (b5).
(B1) The melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg obtained in conformity with ASTM D1238-89 is 0.1 g / 10 min or more and 30 g / 10 min or less. The lower limit is preferably 0.5 g / 10 minutes, more preferably 1.0 g / 10 minutes, and the upper limit is preferably 10 g / 10 minutes, more preferably 5.0 g / 10 minutes. When the melt flow rate (MFR) is at least the above lower limit, the shear viscosity is not too high in the propylene-based resin composition, and the fluidity in the mold at the time of injection foam molding is good. When the melt flow rate (MFR) is not more than the above upper limit value, the melt tension of the propylene-based resin composition becomes high, and an injection foam molded article with fine foam cells can be obtained.

  The melt flow rate (MFR) strongly depends on the molecular weight. The smaller the melt flow rate (MFR), the larger the molecular weight, and the larger the melt flow rate (MFR), the smaller the molecular weight. In addition, it is known that the molecular weight of an ethylene polymer is determined by the composition ratio (hydrogen / ethylene) of hydrogen and ethylene in the polymerization system (for example, Kazuo Soga et al., “Catalytic Olefin Polymerization”, Kodansha Scientific, 1990, p. 376). For this reason, it is possible to increase / decrease the melt flow rate (MFR) of an ethylene-type polymer ((alpha)) by increasing / decreasing hydrogen / ethylene.

Melt flow rate (MFR) is measured under conditions of 190 ° C. and 2.16 kg load according to ASTM D1238-89.
(B2) density is 875kg / m ³ or more 945 kg / m ³ or less. The lower limit is preferably 885 kg / m ³ , more preferably 900 kg / m ³ , and the upper limit is preferably 935 kg / m ³ , more preferably 930 kg / m ³ . When the density is equal to or higher than the lower limit, the rigidity of the injection foam molded article is improved. When the density is equal to or lower than the upper limit, an injection foam molded article having good impact resistance can be obtained.

  The density depends on the α-olefin content of the ethylene polymer. The smaller the α-olefin content, the higher the density, and the higher the α-olefin content, the lower the density. Further, it is known that the α-olefin content in an ethylene polymer is determined by the composition ratio of α-olefin and ethylene (α-olefin / ethylene) in the polymerization system (for example, Walter Kaminsky, Makromol. Chem. 193, p.606 (1992)). For this reason, the ethylene polymer which has the density of the said range can be manufactured by increasing / decreasing (alpha) -olefin / ethylene.

  The measurement of the density is based on JIS K7112, and the strand obtained at the time of melt flow rate (MFR) measurement is heat-treated at 100 ° C. for 1 hour, further left at room temperature for 1 hour, and then measured by the density gradient tube method.

(B3) Sum [(Me + Et) (/ 1000C) of methyl branch number [Me (/ 1000C)] and ethyl branch number [Et (/ 1000C)] per 1000 carbon atoms measured by ¹³ C-NMR )] Is 1.80 or less, preferably 1.30 or less, more preferably 0.80 or less, and even more preferably 0.50 or less. The number of methyl branches and the number of ethyl branches defined in the present invention are defined by the number per 1000 carbons as described later.

  If there are short chain branches such as methyl branch and ethyl branch in the ethylene-based polymer, the short chain branch is incorporated into the crystal and the interplanar spacing of the crystal widens, which may reduce the mechanical strength of the resin. It is known (for example, supervised by Zenjiro Osawa et al., “Technology for predicting and extending the life of polymers”, NTS Corporation, 2002, p. 481). In the present invention, if the sum of the number of methyl branches and the number of ethyl branches ((Me + Et) (/ 1000C)) is 1.8 or less, the spread of crystal plane spacing can be suppressed, and the propylene resin composition The mechanical strength can be maintained satisfactorily, good injection molding fluidity can be obtained, and it can be applied to a large injection foam molded article.

  The number of methyl branches and the number of ethyl branches in the ethylene polymer depend strongly on the polymerization method of the ethylene polymer, and the ethylene polymer obtained by high-pressure radical polymerization is obtained by coordination polymerization using a Ziegler type catalyst. The number of methyl branches and the number of ethyl branches are larger than the obtained ethylene polymer. In the case of coordination polymerization, the number of methyl branches and the number of ethyl branches in the ethylene polymer strongly depend on the composition ratio of propylene, 1-butene and ethylene (propylene / ethylene, 1-butene / ethylene) in the polymerization system. To do. For this reason, it is possible to increase / decrease the sum ((Me + Et) (/ 1000C)) of the number of methyl branches and the number of ethyl branches of an ethylene polymer by increasing / decreasing 1-butene / ethylene.

^The number of methyl branches and the number of ethyl branches measured by ¹³ C-NMR are determined as follows.
The measurement was performed using an AVANCE III cryo-500 type nuclear magnetic resonance apparatus manufactured by Bruker BioSpin Corporation under the following conditions.
Measuring probe: 5mm cryoprobe (DCH type)
Measurement nucleus: ¹³ C (125 MHz)
Measurement mode: Single pulse proton broadband decoupling Pulse width: 45 ° (5.00 microseconds)
Number of points: 64k
Observation range: 250 ppm (-55 to 195 ppm)
Repeat time: 5.5 seconds Integration count: 256 Measurement solvent: Orthodichlorobenzene / benzene-d ₆ (4/1 v / v)
Sample concentration: 60 mg / 0.6 ml
Measurement temperature: 120 ° C
Window function: exponential (BF: 1.0Hz)
Chemical shift standard: δδ signal 29.73ppm

  The attribution of each absorption in the NMR spectrum is as follows: Chemical Domain No. 141 NMR-Review and Experiment Guide [I], p. It carried out according to 132-133. The number of methyl branches per 1,000 carbons, that is, the number of methyl branches per 1000 carbon atoms constituting the polymer chain of the ethylene-based polymer is derived from methyl branches with respect to the integral sum of absorption appearing in the range of 5 to 45 ppm. It is calculated from the integrated intensity ratio of the absorption (19.7 ppm) of the methyl group. The number of ethyl branches is calculated from the ratio of the integrated intensity of the absorption of methyl groups derived from ethyl branches (10.8 ppm) to the integrated sum of absorptions appearing in the range of 5 to 45 ppm.

(B4) The ratio (η ₀ ) of zero shear viscosity [η ₀ (P)] at 200 ° C. to the 6.8th power (Mw ^6.8 ) of the weight average molecular weight measured by the GPC-viscosity detector method (GPC-VISCO). / Mw ^6.8 ) is 0.03 × 10 ⁻³⁰ or more and 7.5 × 10 ⁻³⁰ or less. That is, in the ethylene polymer (B) used in the present invention, η ₀ and Mw are represented by the following formula (Eq-2)
0.03 × 10 ⁻³⁰ ≦ η ₀ / Mw ^6.8 ≦ 7.5 × 10 ⁻³⁰ -------- (Eq-2)
Meet. Here, the lower limit is preferably 0.05 × 10 ⁻³⁰ , more preferably 0.08 × 10 ⁻³⁰ , and the upper limit is preferably 5.0 × 10 ⁻³⁰ , more preferably 3.0 × 10. ^-30 .

eta ₀ / Mw ^6.8 is, it is 0.03 × 10 ^-30 over 7.5 × 10 ^-30 or less, upon log-log plot of eta ₀ and Mw, log (η ₀₎ and logMw the following formula It is synonymous with existing in the region defined by (Eq-2 ′).
6.8 Log (Mw) -31.523 ≦ Log (η ₀ ) ≦ 6.8 Log (Mw) −29.125 ------- (Eq-2 ′)

An ethylene-based polymer in which zero shear viscosity [η ₀ (P)] is plotted on a logarithmic scale with respect to the weight average molecular weight (Mw), there is no long-chain branching, it is linear, and the elongational viscosity does not exhibit strain rate curability. Follows the power law with a slope of 3.4. On the other hand, an ethylene polymer having many relatively short long-chain branches and having an extensional viscosity exhibiting strain rate curability exhibits a zero shear viscosity [η ₀ (P)] lower than the power law, and its slope is It is known that the value is larger than 3.4 (C Gabriel, H. Munstedt, J. Rheol., 47 (3), 619 (2003), H. Munstedt, D. Auhl, J. Non- Newtonian Fluid Mech. 128, 62-69, (2005)), slope 6.8 can be chosen empirically. Taking the ratio between η ₀ and Mw ^6.8 is also disclosed in Japanese Patent Laid-Open No. 2011-1545. Here, the strain rate curability refers to a phenomenon in which the extensional viscosity increases when the strain rate is increased in the extensional viscosity measurement.

When η ₀ / Mw ^6.8 is in the desired range, the ethylene polymer (B) elongation stress increases due to strain rate curability in a general molding process, and the melt tension of the propylene resin composition increases. An injection foamed molded article having fine cells can be obtained.

It is known that the tensile stress is strongly influenced by the number and length of long chain branches, and the tensile stress increases as the number increases and the length increases. If η ₀ / Mw ^6.8 exceeds the upper limit value, the number of long chain branches tends to be insufficient, and if it is less than the lower limit value, the length of long chain branches tends to be insufficient.

The relationship between the zero shear viscosity [η ₀ (P)] and the weight average molecular weight (Mw) is considered to depend on the content and length of the long chain branch in the ethylene polymer. The greater the number of long chain branches and the shorter the length of the long chain branches, the zero shear viscosity [η ₀ (P)] is closer to 0.03 × 10 ^−30. The longer the length, the zero shear viscosity [η ₀ (P)] is considered to show a value closer to 7.5 × 10 ⁻³⁰ .

  Here, the long chain branching is defined as a branched structure having a length equal to or greater than the molecular weight (Me) between the entanglement points contained in the ethylene polymer, and by introduction of the long chain branching, the melt property of the ethylene polymer, and It is known that the moldability changes remarkably (for example, Kazuo Matsuura et al., “Polyethylene Technology Reader”, Industrial Research Society, 2001, p. 32, 36). As described later, the ethylene polymer (B) according to the present invention includes, for example, a component (α), a component (β), and a component (γ described later in the section “Catalyst for producing an ethylene polymer (B)”. In the presence of an olefin polymerization catalyst containing), it is preferable to produce ethylene by polymerizing at least one α-olefin having 4 to 10 carbon atoms.

  In the mechanism for producing the ethylene polymer according to the present invention, the present inventors have determined that the component (α) and the component (γ) and, if necessary, the “catalyst for production of ethylene polymer (B)” described later. In the presence of a catalyst component containing the solid support (S) described later in the section, ethylene and an α-olefin having 4 to 10 carbon atoms are copolymerized to have a number average molecular weight of 4,000 to 20,000, preferably 4,000. A “macromonomer”, which is a polymer having a terminal vinyl of 15000 or less, is produced, and then ethylene is produced by a catalyst component containing the component (β) and the component (γ) and, if necessary, the solid carrier (S). And the macromonomer is copolymerized competitively with the polymerization of the α-olefin having 4 to 10 carbon atoms to form a long chain branch in the ethylene-based polymer (B). It has been estimated.

  The higher the composition ratio ([macromonomer] / [ethylene]) of the macromonomer and ethylene in the polymerization system, the greater the long chain branching content. Increase the ratio of component (α) in the olefin polymerization catalyst, that is, the molar ratio of component (α) to the sum of component (α) and component (β) ([α] / [α + β]). Can increase [macromonomer] / [ethylene] and increase the long chain branching content. Moreover, since the molecular weight of a macromonomer will become small when the composition ratio (hydrogen / ethylene) of hydrogen and ethylene in a polymerization system is made high, the length of the long chain branch introduced into an ethylene polymer becomes short.

From this fact, an ethylene polymer having η ₀ / Mw ^6.8 in the above range can be produced by increasing or decreasing [α] / [α + β] and hydrogen / ethylene.
In addition to these, polymerization conditions for controlling the amount of long-chain branching are disclosed in, for example, International Publication No. 2007/034920.

The zero shear viscosity [η ₀ (P)] at 200 ° C. is determined as follows. The angular velocity [ω (rad / sec)] dispersion of the shear viscosity (η ^* ) at a measurement temperature of 200 ° C. is measured in the range of 0.01 ≦ ω ≦ 100. Anton Paar viscoelasticity measuring device Physica MCR301 is used for the measurement. The sample holder was a 25 mmφ parallel plate, and the sample thickness was about 2.0 mm. The number of measurement points is 5 points per ω digit. The amount of strain is appropriately selected within a range of 3 to 10% so that the torque in the measurement range can be detected and torque is not exceeded. The sample used for the shear viscosity measurement was a press molding machine manufactured by Shinfuji Metal Industry, with a preheating temperature of 190 ° C., a preheating time of 5 minutes, a heating temperature of 190 ° C., a heating time of 2 minutes, a heating pressure of 100 kgf / cm ² , and a cooling temperature of 20 It is prepared by press-molding a measurement sample to a thickness of 2 mm under the conditions of a cooling pressure of 100 kgf / cm ² at 5 ° C. and a cooling time of 5 minutes.

The zero shear viscosity η ₀ is calculated by fitting the Carreau model of the following formula (Eq-3) to an actually measured rheological curve [angular velocity (ω) dispersion of shear viscosity (η ^* )] by a nonlinear least square method.

η ^* = η ₀ [1+ (λω) ^a ] ^{(n-1) / a} --- (Eq-3)
Here, λ is a parameter having a time dimension, n is a power law index of the material, and a is a fitting parameter in the Carreau model. The fitting by the nonlinear least square method is performed so that d in the following mathematical formula (Eq-4) is minimized.

Here, η _exp (ω) represents the measured shear viscosity, and η _calc (ω) represents the shear viscosity calculated from the Carreau model.

  The weight average molecular weight (Mw) by GPC-VISCO method is measured as follows using GPC / V2000 manufactured by Waters. The guard column uses Shodex AT-G, the analytical column uses two AT-806MS, the column temperature is 145 ° C., the mobile phase uses o-dichlorobenzene and BHT 0.3 wt% as an antioxidant, 1. The sample is moved at 0 ml / min, the sample concentration is 0.1% by weight, and a differential refractometer and 3-capillary viscometer are used as detectors. Standard polystyrene used was manufactured by Tosoh Corporation. In the molecular weight calculation, an actual viscosity is calculated from a viscometer and a refractometer, and a weight average molecular weight (Mw) is calculated from an actual universal calibration.

(B5) Intrinsic viscosity [[η] (dl / g)] measured in decalin at 135 ° C. and 0.776 of the weight average molecular weight measured by GPC-viscosity detector method (GPC-VISCO) (Mw ^0.776 ) ([η] / Mw ^0.776 ) is 0.90 × 10 ⁻⁴ or more and 1.65 × 10 ⁻⁴ or less. That is, in the ethylene polymer (B) used in the present invention, [η] and Mw are represented by the following formula (Eq-5)
0.90 × 10 ⁻⁴ ≦ [η] / Mw ^0.776 ≦ 1.65 × 10 ⁻⁴ -------- (Eq-5)
Meet. Here, the lower limit is preferably 0.95 × 10 ⁻⁴ , more preferably 1.00 × 10 ⁻⁴ , and the upper limit is preferably 1.55 × 10 ⁻⁴ , more preferably 1.45 × 10 6. ^-4 .

[η] / Mw ^0.776 is 0.90 × 10 ⁻⁴ or more and 1.65 × 10 ⁻⁴ or less when logarithm plotting [η] and Mw is log ([η]) and log (Mw) is synonymous with existing in the region defined by the following formula (Eq-5 ′).

0.776 Log (Mw) -4.046 ≦ Log ([η]) ≦ 0.776 Log (Mw) −3.783 ------- (Eq-5 ′)
It is known that when long chain branching is introduced into an ethylene polymer, the intrinsic viscosity [η] (dl / g) is smaller for the molecular weight than a straight chain ethylene polymer without long chain branching. (For example, Walther Burchard, ADVANCES IN POLYMER SCIENCE, 143, Branched Polymer II, p.137 (1999)).

  In addition, based on the Mark-Houwink-Sakurada equation, [η] for polyethylene is 0.7 for Mv, [η] for polypropylene is 0.80 for Mw, and [η] for poly-4-methyl-1-pentene. Has been reported to be proportional to Mn to the power of 0.81 (eg R. Chiang, J. Polym. Sci., 36, 91 (1959): P. 94, R. Chiang, J. Polym. Sci. , 28, 235 (1958): P.237, AS Hoffman, BA Fries and PC Condit, J. Polym. Sci. Part C, 4, 109 (1963): P.119 Fig. 4).

  As a typical index of a copolymer of ethylene and an α-olefin having 4 or more and 10 or less carbon atoms, Mw is set to a power of 0.776, and the molecular weight is less than that of a conventional ethylene polymer. The requirement (b5) expresses that [η] is small, and this idea is disclosed in the pamphlet of International Publication No. 2006/080578.

Therefore, when [η] / Mw ^{0.776 of} the ethylene polymer (B) is 1.65 × 10 ⁻⁴ or less, it has many long chain branches, and injection molding of the resulting propylene resin composition Excellent fluidity and can be suitably used for large injection-foamed molded articles.

  Since the long chain branching content is increased by increasing the ratio ([α] / [α + β]) of the component (α) in the olefin polymerization catalyst as described above, [α] / [α + β ] Can be increased or decreased to produce an ethylene polymer (B) having a desired intrinsic viscosity [η].

The intrinsic viscosity [η] (dl / g) was measured as follows using a decalin solvent. About 20 mg of a sample is dissolved in 15 ml of decalin, and the specific viscosity η _sp is measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to this decalin solution for dilution, the specific viscosity η _sp is measured in the same manner. This dilution operation was further repeated twice, and the η _sp / C value when the concentration (C) was extrapolated to 0 was defined as the intrinsic viscosity [η]. (Refer to the following formula (Eq-6))
[Η] = lim (η _sp / C) (C → 0) ---------- (Eq-6)
The ethylene polymer (B) preferably further satisfies the following requirement (b6) in addition to the above requirements (b1) to (b5).

(B6) The ratio [MTα / η ^* (g / P)] of the melt tension [MTα (g)] at 190 ° C. and the shear viscosity [η ^* (P)] at 200 ° C. and an angular velocity of 1.0 rad / sec. It is 1.0 × 10 ⁻⁴ or more and 7.0 × 10 ⁻⁴ or less. That is, in the ethylene polymer (B) used in the present invention, MTα and η ^* are represented by the following formula (Eq-7)
1.0 × 10 ⁻⁴ ≦ MTα / η ^* ≦ 7.0 × 10 ⁻⁴ -------- (Eq-7)
It is preferable to satisfy. Here, the upper limit is preferably 5.0 × 10 ⁻⁴ , more preferably 3.0 × 10 ⁻⁴ .

[MTα / η ^* (g / P)] indicates the melt tension per unit shear viscosity. If this value is large, the melt tension increases relative to the shear viscosity, and the melt tension of the propylene resin composition also increases. An injection foam molded article having fine cells can be obtained.

MTα / η ^* is believed to depend on the long chain branching content of the ethylene-based polymer, the more long chain branching content MTα / η ^* is large, MTα / η ^* is reduced the smaller the long chain branching content Tend.

Since the long chain branching content is increased by increasing the ratio ([α] / [α + β]) of the component (α) in the olefin polymerization catalyst as described above, [α] / [α + β ] Can be increased or decreased to produce an ethylene polymer (B) having MTα / η ^* in the above range.

  The melt tension (MT) is a value measured by the following method. Melt tension (MT) is determined by measuring the stress when the molten polymer is stretched at a constant rate. For the measurement, a capillary rheometer: Capillograph 1B manufactured by Toyo Seiki Seisakusho was used. The conditions are as follows: resin temperature 190 ° C., melting time 6 minutes, barrel diameter 9.55 mmφ, extrusion speed 15 mm / minute, winding speed 24 mm / minute (if the molten filament breaks, the winding speed is 5 m / minute) The nozzle diameter is 2.095 mmφ and the nozzle length is 8 mm.

Further, the shear viscosity [η ^* (P)] at 200 ° C. and the angular velocity of 1.0 rad / sec is 0.01 ≦ the dispersion of the angular velocity [ω (rad / sec)] of the shear viscosity (η ^* ) at the measurement temperature of 200 ° C. Measurement is performed in the range of ω ≦ 100. Anton Paar viscoelasticity measuring device Physica MCR301 is used for the measurement. The sample holder uses a 25 mmφ parallel plate and the sample thickness is about 2.0 mm. The number of measurement points is 5 points per ω digit. The amount of strain is appropriately selected within a range of 3 to 10% so that the torque in the measurement range can be detected and torque is not exceeded. The sample used for the shear viscosity measurement was a press molding machine manufactured by Shinfuji Metal Industry, with a preheating temperature of 190 ° C., a preheating time of 5 minutes, a heating temperature of 190 ° C., a heating time of 2 minutes, a heating pressure of 100 kgf / cm ² , and a cooling temperature of 20 It is prepared by press-molding a measurement sample to a thickness of 2 mm under the conditions of a cooling pressure of 100 kgf / cm ² at 5 ° C. and a cooling time of 5 minutes.

The ethylene polymer (B) preferably further satisfies the following requirement (b7).
(B7) The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by measurement by GPC (gel permeation chromatography) is 1.0 × 10 ^4.20 or more and 1.0 × 10 ^4.60 or less. The lower limit is preferably 1.0 × 10 ^4.30 and the upper limit is preferably 1.0 × 10 ^4.50 .

It is known that low molecular weight components have a strong influence on the mechanical strength of ethylene polymers. The presence of low molecular weight components is thought to decrease the mechanical strength due to an increase in molecular ends that are considered to be the starting point of destruction (edited by Kazuo Matsuura and Naotaka Mikami, “Polyethylene Technology Reader”, Inc. Industrial Research Committee, 2001, p. 45). When the molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is 1.0 × 10 ^4.20 or more, there are few low molecular weight components that adversely affect the mechanical strength. Excellent. When it is higher than 1.0 × 10 ^4.60, there is a concern that in the propylene-based resin composition, the dispersibility of the ethylene-based polymer is deteriorated and appearance defects such as blisters may occur on the surface of the injection-foamed molded body.

  It is known that the molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is determined by the composition ratio (hydrogen / ethylene) of hydrogen and ethylene in the polymerization system. (For example, Kazuo Soga et al., “Catalytic Olefin Polymerization”, Kodansha Scientific, 1990, p.376). Therefore, by increasing / decreasing hydrogen / ethylene, it is possible to increase / decrease the molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve.

  The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve is calculated as follows using a gel permeation chromatograph alliance GPC2000 (high temperature size exclusion chromatograph) manufactured by Waters.

[Devices and conditions]
Analysis software: Chromatography data system Empower (Waters, registered trademark)
Column: TSKgel GMH ₆ -HT x 2 + TSKgel GMH _6- HTL x 2
(Inner diameter 7.5mm x length 30cm, Tosoh Corporation)
Mobile phase: o-dichlorobenzene (Wako Pure Chemicals special grade reagent)
Detector: Differential refractometer (built-in device)
Column temperature: 140 ° C
Flow rate: 1.0 mL / min Injection volume: 500 μL
Sampling time interval; 1 second Sample concentration; 0.15% (w / v)
Molecular weight calibration; monodisperse polystyrene (Tosoh Corp.) / Molecular weight 495-molecular weight 20.6 million
A molecular weight distribution curve is prepared in terms of polyethylene molecular weight according to the general calibration procedure described in Z. Crubisic, P. Rempp, H. Benoit, J. Polym. Sci., B5, 753 (1967). From this molecular weight distribution curve, the molecular weight (peak top M) at the maximum weight fraction is calculated.

(Method for producing ethylene polymer (B))
-Ethylene-based polymer (B) production catalyst The ethylene-based polymer (B) according to the present invention comprises at least 1 in the presence of a catalyst containing the component (α), the component (β) and the component (γ). It can be efficiently produced by polymerizing an α-olefin having 4 or more and 10 or less carbon atoms.

  The catalyst for producing an ethylene polymer (B) used in the present invention comprises a solid carrier (S) and a component (G) in addition to the components (α), (β) and (γ) described below. May be included.

Each component used in the catalyst will be described.
・ Ingredient (α)
The component (α) that can be used in the present invention is a bridged metallocene compound represented by the following general formula (I).

In general formula (I), M represents a group 4 transition metal atom in the periodic table, specifically a transition metal atom selected from titanium, zirconium and hafnium, preferably zirconium.

R ^{1 to} R ⁸ are a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, germanium It is selected from a containing group and a tin-containing group, which may be the same or different from each other, but all are not hydrogen atoms at the same time. Moreover, R < ¹ > -R < ⁸ > may combine an adjacent group mutually and may form an aliphatic ring.

  Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, and an arylalkyl group. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, Examples include n-octyl group, nonyl group, dodecyl group, and eicosyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group. Examples of the alkenyl group include a vinyl group, a propenyl group, and a cyclohexenyl group. The aryl group includes phenyl, tolyl, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenyl, α- or β-naphthyl, methylnaphthyl, anthracenyl, phenanthryl, benzylphenyl, pyrenyl, acenaphthyl, phenalenyl, aceanthrylenyl, Tetrahydronaphthyl, indanyl and biphenylyl. Arylalkyl groups include benzyl, phenylethyl and phenylpropyl.

A preferred group for R ^{1 to} R ⁸ is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, more preferably 6 or more of R ^{1 to} R ⁸ substituents are hydrogen atoms, and particularly preferred. Of the substituents of R ^{1 to} R ⁸ are hydrogen atoms and the remaining one is an alkyl group having 3 to 15 carbon atoms.

Q ¹ is a divalent group that binds two ligands, and includes a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group, and an alkylidene group, a halogen-containing group, a silicon-containing group, germanium A group selected from a containing group and a tin-containing group, and a silicon-containing group is particularly preferred.

  Specific examples of the alkylene group, substituted alkylene group and alkylidene group include alkylene groups such as methylene, ethylene, propylene and butylene; isopropylidene, diethylmethylene, dipropylmethylene, diisopropylmethylene, dibutylmethylene, methylethylmethylene, methylbutylmethylene Methyl-t-butylmethylene, dihexylmethylene, dicyclohexylmethylene, methylcyclohexylmethylene, methylphenylmethylene, diphenylmethylene, ditolylmethylene, methylnaphthylmethylene, dinaphthylmethylene, 1-methylethylene, 1,2-dimethylethylene and 1 A substituted alkylene group such as ethyl-2-methylethylene; cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, Kurohepuchiriden, bicyclo [3.3.1] nonylidene, norbornylidene, adamantylidene, cycloalkylidene group and ethylidene such tetrahydronaphthyl dust den and dihydroindolyl mites alkylidene, and the like alkylidene group such as propylidene and butylidene.

  Examples of silicon-containing groups include silylene, methylsilylene, dimethylsilylene, diisopropylsilylene, dibutylsilylene, methylbutylsilylene, methyl-t-butylsilylene, dicyclohexylsilylene, methylcyclohexylsilylene, methylphenylsilylene, diphenylsilylene, ditolylsilylene, methyl Examples include naphthylsilylene, dinaphthylsilylene, cyclodimethylenesilylene, cyclotrimethylenesilylene, cyclotetramethylenesilylene, cyclopentamethylenesilylene, cyclohexamethylenesilylene, cycloheptamethylenesilylene, and the like, particularly preferably dimethylsilylene group and dibutyl And dialkylsilylene groups such as a silylene group.

X is each independently an atom or group selected from a hydrogen atom, a halogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, and a phosphorus-containing group. Preferably a halogen atom or a hydrocarbon group. Examples of the halogen atom include fluorine, chlorine, bromine and iodine, and particularly preferably chlorine. Examples of the hydrocarbon group include the same hydrocarbon groups as R ^{1 to} R ⁸ described above, and an alkyl group having 1 to 20 carbon atoms is particularly preferable.

  Specific examples of preferred compounds of the component (α) represented by the general formula (I) include dimethylsilylene bis (cyclopentadienyl) zirconium dichloride, dimethylsilylene bis (2-methylcyclopentadienyl) zirconium dichloride, dimethylsilylene. Bis (3-methylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (3-n-butylcyclopentadienyl) zirconium dichloride, dimethylsilylene (cyclopentadienyl) (3-ethylcyclopentadienyl) zirconium dichloride, Dimethylsilylene (cyclopentadienyl) (3-n-propylcyclopentadienyl) zirconium dichloride, dimethylsilylene (cyclopentadienyl) (3-n-butylcyclopentadienyl) zirconium dichloride Dimethylsilylene (cyclopentadienyl) (3-n-octylcyclopentadienyl) zirconium dichloride, dibutylsilylene (cyclopentadienyl) (3-n-propylcyclopentadienyl) zirconium dichloride, dimethylsilylene (cyclopentadiene) Enyl) (3-n-butylcyclopentadienyl) zirconium dichloride, dimethylsilylene (cyclopentadienyl) (3-n-octylcyclopentadienyl) zirconium dichloride, trifluoromethylbutylsilylene (cyclopentadienyl) ( 3-n-propylcyclopentadienyl) zirconium dichloride, trifluoromethylbutylsilylene (cyclopentadienyl) (3-n-butylcyclopentadienyl) zirconium dichloride, trifluoro Examples include butylbutylsilylene (cyclopentadienyl) (3-n-octylcyclopentadienyl) zirconium dichloride, and more preferred specific examples include dimethylsilylene (cyclopentadienyl) (3-n-propylcyclopentadiene). Enyl) zirconium dichloride and dimethylsilylene (3-n-butylcyclopentadienyl) (cyclopentadienyl) zirconium dichloride.

・ Ingredient (β)
The component (β) that can be used in the present invention is a bridged metallocene compound represented by the following general formula (II).

In the general formula (II), M represents a Group 4 transition metal atom in the periodic table, specifically a transition metal atom selected from titanium, zirconium and hafnium, preferably zirconium.

R ^{9 to} R ²⁰ are hydrogen atoms, hydrocarbon groups, halogen-containing groups, oxygen-containing groups, nitrogen-containing groups, boron-containing groups, sulfur-containing groups, phosphorus-containing groups, silicon-containing groups, germanium-containing groups, and tin-containing groups. And may be the same or different from each other, and two adjacent groups may be connected to each other to form a ring. Preferred groups for R ^{9 to} R ²⁰ are a hydrogen atom and a hydrocarbon group, more preferably R ^{9 to} R ¹² are a hydrogen atom, and R ^{13 to} R ²⁰ are a hydrogen atom or an alkyl having 1 to 20 carbon atoms. It is a group.

Q ² is a divalent group that binds two ligands, and includes a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group, and an alkylidene group, a halogen-containing group, a silicon-containing group, A group selected from a germanium-containing group and a tin-containing group, preferably a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group and an alkylidene group, and a silicon-containing group, and particularly preferably an alkylene group And a hydrocarbon group having 1 to 10 carbon atoms such as a substituted alkylene group and an alkylidene group.

X may be the same as X in the above formula (I).
Specific examples of preferable compounds of the component (β) represented by the general formula (II) include isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (2,7-di- t-butyl-9-fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (octamethyloctahydridodi Benzfluorenyl) zirconium dichloride, dibutylmethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride, dibutylmethylene (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, dibutylmethyle (Cyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride, dibutylmethylene (cyclopentadienyl) (octamethyloctahydridodibenzfluorenyl) zirconium dichloride, cyclohexylidene (cyclo Pentadienyl) (fluorenyl) zirconium dichloride, cyclohexylidene (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, cyclohexylidene (cyclopentadienyl) (3,6- Di-t-butylfluorenyl) zirconium dichloride, cyclohexylidene (cyclopentadienyl) (octamethyloctahydridodibenzfluorenyl) zirconium dichloride, dimethylsilyl (cyclopentadienyl) (fluorenyl) zirco Nium dichloride, dimethylsilyl (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, dimethylsilyl (cyclopentadienyl) (3,6-di-t-butylfluorenyl) Zirconium dichloride and dimethylsilyl (cyclopentadienyl) (octamethyloctahydridodibenzfluorenyl) zirconium dichloride are mentioned, and more preferred specific examples include isopropylidene (cyclopentadienyl) (2,7-di-t -Butyl-9-fluorenyl) zirconium dichloride and the like.

・ Ingredient (γ)
The component (γ) that can be used in the present invention is at least one compound selected from the group consisting of the following (γ-1) to (γ-3).

(Γ-1) an organometallic compound represented by the following general formula (III), (IV) or (V),
R ^α _m Αl (OR ^β ) _n H _p X _q (III)
[In the general formula (III), R ^α and R ^β represent a hydrocarbon group having a carbon elution temperature number of 1 to 15, which may be the same or different from each other, X represents a halogen atom, and m represents 0 < m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number of 0 ≦ q <3, and m + n + p + q = 3. ]
M ^α ΑlR ^α ₄ (IV)
[In the general formula (IV), M ^α represents a Li, Na or K, the R ^alpha represents a hydrocarbon group having 1 to 15 carbon atoms. ]
R ^α _r M ^β R ^β _s X _t (V)
[In the general formula (V), R ^α and R ^β represent a hydrocarbon group having 1 to 15 carbon atoms, which may be the same or different from each other, M ^β represents Mg, Zn or Cd, and X Represents a halogen atom, r is 0 <r ≦ 2, s is 0 ≦ s ≦ 1, t is 0 ≦ t ≦ 1, and r + s + t = 2. ]

(Γ-2) an organoaluminum oxy compound, and
(Γ-3) a compound that reacts with component (α) and component (β) to form an ion pair,
At least one compound selected from the group consisting of

  Among the organometallic compounds (γ-1) represented by the general formula (III), (IV) or (V), those represented by the general formula (III) are preferable, and specifically, trimethylaluminum, triethyl Trialkylaluminums such as aluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum and trioctylaluminum; and dimethylaluminum hydride, diethylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride and diiso Examples include alkyl aluminum hydrides such as hexyl aluminum hydride. These are used singly or in combination of two or more.

  As the organoaluminum oxy compound (γ-2), an organoaluminum oxy compound prepared from trialkylaluminum or tricycloalkylaluminum is preferable, and an aluminoxane prepared from trimethylaluminum or triisobutylaluminum is particularly preferable. Such organoaluminum oxy compounds are used singly or in combination of two or more.

  Examples of the compound (γ-3) that forms an ion pair by reacting with the component (α) and the component (β) include JP-A-1-501950, JP-A-1-502036, and JP-A-3-179005. Lewis acids, ionic compounds, borane compounds and carborane compounds, and heteropoly compounds described in JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, US Pat. Isopoly compounds can be used without limitation.

・ Solid carrier (S)
In the present invention, the solid carrier (S) that can be used as necessary is an inorganic or organic compound, which is a granular or fine particle solid.

Among these, examples of the inorganic compound include porous oxides, inorganic chlorides, clays, clay minerals, and ion-exchangeable layered compounds, and porous oxides are preferable.
Examples of the porous oxide include SiO ₂ , Αl ₂ O ₃ , MgO, ZrO, TiO ₂ , Β ₂ O ₃ , CaO, ZnO, ΒaO, and ThO ₂ , or a composite or mixture containing these, specifically Natural or synthetic zeolite, SiO ₂ —MgO, SiO ₂ —I ₂ O ₃ , SiO ₂ —TiO ₂ , SiO ₂ —V ₂ O ₅ , SiO ₂ —Cr ₂ O _3, SiO ₂ —TiO ₂ —MgO, etc. Used. Of these, those containing SiO ₂ as the main component are preferred.

Such porous oxides have different properties depending on the type and production method. Therefore, in the present invention, when a porous oxide is used as the solid support, the type and properties are not particularly limited as long as the effects of the present invention are exhibited, but the particle size is usually 0.2 to 300 μm, preferably 1 a ～200Myuemu, specific surface area of usually 50~1200m ² / g, preferably in the range of 100~1000m ² / g, is preferred pore volume is in the range of usually 0.3~30cm ³ / g . Such a carrier is used, for example, after calcining at 100 to 1000 ° C., preferably 150 to 700 ° C., if necessary.

・ Ingredient (G)
In the present invention, the component (G) that can be used as necessary includes at least one compound selected from the group consisting of the following (g-1) to (g-6).

(G-1) polyalkylene oxide block,
(G-2) a higher aliphatic amide,
(G-3) polyalkylene oxide,
(G-4) polyalkylene oxide alkyl ether,
(G-5) alkyldiethanolamine, and (g-6) polyoxyalkylenealkylamine.

  In the present invention, such a component (G) is present in the catalyst for producing the ethylene polymer (B) for the purpose of suppressing fouling in the reactor or improving the particle properties of the produced polymer. Can be made. Among the components (G), (g-1), (g-2), (g-3) and (g-4) are preferable, and (g-1) and (g-2) are particularly preferable. Here, examples of (g-2) include higher fatty acid diethanolamide.

-Preparation method of the catalyst for ethylene polymer (B) manufacture It describes about the preparation method of the catalyst for ethylene polymer (B) used by this invention.
The above-mentioned catalyst for producing an ethylene polymer (B) is obtained by adding the component (α), the component (β) and the component (γ) into an inert hydrocarbon or a polymerization system using an inert hydrocarbon. Can be prepared.

The order of adding each component is arbitrary, but as a preferred order, for example,
i) Method in which component (α) and component (β) are mixed and contacted, and then component (γ) is contacted and added to the polymerization system. ii) Component (α) and component (γ) are mixed and contacted And adding a contact product obtained by mixing and contacting the product (β) and the component (γ) into the polymerization system. Iii) Component (α), component (β) and component (γ) are continuously added to the polymerization system. And the like, and the like.

When the solid support (S) is contained, at least one of the component (α), the component (β) and the component (γ) is brought into contact with the solid support (S) in an inert hydrocarbon, so that the solid Catalyst component (X) can be prepared. The order of contacting the components is arbitrary, but as a preferred order, for example,
iv) Method of preparing solid catalyst component (X) by contacting component (γ) and solid support (S) and then contacting component (α) and component (β) v) Component (α), component (Β) and the component (γ) are mixed and contacted, and then the solid support (S) is contacted to prepare the solid catalyst component (X). Vi) The component (γ) and the solid support (S) are mixed. The solid catalyst component (X1) prepared by contacting and then contacting with the component (α), the component (γ) and the solid support (S) are contacted, and then the solid prepared by contacting with the component (β) A method using the catalyst component (X2),
Iv) is more preferable.

  Specific examples of inert hydrocarbons include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Aromatic hydrocarbons such as benzene, toluene and xylene; and halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane or mixtures thereof.

  The contact time between the component (γ) and the solid carrier (S) is usually 0 to 20 hours, preferably 0 to 10 hours, and the contact temperature is usually −50 to 200 ° C., preferably −20 to 120 ° C. It is. The molar ratio of contact between the component (γ) and the solid carrier (S) (component (γ) / solid carrier (S)) is usually 0.2 to 2.0, particularly preferably 0.4 to. 2.0.

  The contact time of the contact product of component (γ) and solid carrier (S) with component (α) and component (β) is usually 0 to 5 hours, preferably 0 to 2 hours, and the contact temperature is Usually, it is −50 to 200 ° C., preferably −50 to 100 ° C. The contact amount between the component (α) and the component (β) largely depends on the type and amount of the component (γ), and when the component (γ-1) is used, the component (α) and the component (β) The molar ratio [(γ-1) / M] of all transition metal atoms (M) and the component (γ-1) is usually 0.01 to 100,000, preferably 0.05 to 50,000. When the component (γ-2) is used, the molar ratio of the aluminum atom in the component (γ-2) to the total transition metal atom (M) in the component (α) and the component (β) [( γ-2) / M] is usually used in an amount of 10 to 500,000, preferably 20 to 100,000. When component (γ-3) is used, component (γ-3) and component (α) are used. And the molar ratio [(γ-3) / M] to all transition metal atoms (M) in the component (β) is usually 1 to 10, preferably 1 to 5. It is needed. The ratio of component (γ) to all transition metal atoms (M) in component (α) and component (β) is determined by inductively coupled plasma (ICP) emission spectroscopy.

  The use amount ratio of the component (α) and the component (β) can be arbitrarily determined from the molecular weight and molecular weight distribution of the ethylene polymer, but as a preferred range, it is generated from the polymer formed from the component (α) and the component (β). Ratio (hereinafter also referred to as “polymer production ratio derived from component (α) and component (β)”) [= the amount of polymer produced by component (α) / the amount of polymer produced by component (β)] Usually, it is 40/60 to 95/5, preferably 50/50 to 95/5, and more preferably 60/40 to 95/5.

The calculation method of the polymer production | generation ratio derived from a component ((alpha)) and a component ((beta)) is demonstrated.
The molecular weight distribution curve of the ethylene polymer (B) obtained by GPC measurement is substantially composed of three peaks. Among these three peaks, the peak on the lowest molecular weight side is a peak attributed to the component (α) -derived polymer, the second peak is a peak attributed to the component (β) -derived polymer, and the third peak That is, the peak on the most polymer side is a peak generated only when both the component (α) and the component (β) are used. The ratio of the peak derived from the component (α) -derived polymer (that is, the peak on the lowest molecular weight side) and the peak derived from the component (β) -derived polymer (that is, the second peak) [= component (Α) peak derived from the polymer derived from (α) / peak derived from the component (β) derived polymer] is the polymer production ratio derived from the component (α) and the component (β) [= the amount of the produced polymer of the component (α) / component ( β) produced polymer amount].

The ratio of each peak is
Molecular weight distribution curve (G1) of ethylene polymer (B),
Polymerization conditions similar to those for obtaining an ethylene polymer (B) using a catalyst comprising the component (α), the component (γ), and the solid carrier (S) (that is, a catalyst not containing the component (β)). Molecular weight distribution curve (G2) of an ethylene polymer obtained by polymerization in
Polymerization conditions similar to those for obtaining an ethylene polymer (B) using a catalyst comprising a component (β), a component (γ), and a solid carrier (S) (that is, a catalyst not containing the component (α)). Using the molecular weight distribution curve (G3) of the ethylene polymer obtained by polymerization in step 1, the following method was used. In the present specification, the term “molecular weight distribution curve” refers to a differential molecular weight distribution curve unless otherwise specified, and the term “area” for the molecular weight distribution curve refers to a molecular weight distribution curve. The area of a region formed between the base line.

  [1] In each numerical data of (G1), (G2), and (G3), Log (molecular weight) is divided into 0.02 intervals, and each of (G1), (G2), and (G3) has an area The intensity [dwt / d (log molecular weight)] is normalized so that becomes 1.

  [2] A composite curve (G4) of (G2) and (G3) is created. At this time, the intensity at each molecular weight of (G2) and (G3) is set to a certain ratio so that the absolute value of the difference between the intensity of (G1) and the intensity of (G4) at each molecular weight is approximately 0.0005 or less. To change it arbitrarily. On the high molecular weight side, the absolute value of the difference between the intensity of (G1) and the intensity of (G4) becomes larger than 0.0005 due to the influence of the third peak to be generated. The intensity of (G2) and (G3) is changed so that the absolute value of the difference between the intensity of (G) and the intensity of (G4) is 0.0005 or less.

  [3] When the molecular weight at the maximum weight fraction in (G1) is the peak top, the part where (G1) and (G4) do not overlap with each other on the high molecular weight side from the peak top, that is, (G1) When a difference curve (G5) with (G4) is created, a peak portion (P5) [(G1) appearing on the higher molecular weight side than the molecular weight at the maximum weight fraction in (G1) in the difference curve (G5) − (G4)] is defined as the third peak (that is, the “third peak”).

[4] The peak ratio Wα attributed to the component (α) -derived polymer and the peak ratio Wβ attributed to the component (β) -derived polymer are calculated as follows.
Wα = S (G2) / S (G4)
Wβ = S (G3) / S (G4)
Here, S (G2) and S (G3) are the areas of (G2) and (G3) after the intensity is changed, and S (G4) is the area of (G4).

For example, when (G4) is obtained by adding x times the intensity of (G2) to x times the intensity of (G2), the normalization is performed by the normalization described in [1] above. Since the areas of (G2) and (G3) are both 1, S (G2), S (G3), and S (G4) are x, y, and (x + y), respectively. Therefore, Wα and Wβ can be expressed as follows using the above x and y, respectively.
Wα = x / (x + y)
Wβ = y / (x + y)

  A larger amount of the polymer derived from the component (α) is advantageous in producing long chain branching. The molar ratio of the component (α) and the component (β) per transition metal compound can be arbitrarily selected within a range where the produced polymer satisfies the above ratio.

  For the production of the ethylene polymer (B), the solid catalyst components (X) to (X2) as described above can be used as they are, but olefins are prepolymerized on the solid catalyst components (X) to (X2). Can be used after forming the prepolymerized catalyst component (XP).

  The prepolymerization catalyst component (XP) can be prepared by introducing an olefin in an inert hydrocarbon solvent in the presence of the solid catalyst components (X) to (X2). Either of the method and the continuous method can be used, and the reaction can be performed under reduced pressure, normal pressure or increased pressure. By this prepolymerization, a polymer of usually 0.01 to 1000 g, preferably 0.1 to 800 g, more preferably 0.2 to 500 g is produced per 1 g of the solid catalyst component.

  The prepolymerization catalyst component prepared in the inert hydrocarbon solvent may be separated from the suspension, then suspended in the inert hydrocarbon again, and the olefin may be introduced into the resulting suspension. Further, olefin may be introduced after drying.

In the prepolymerization, the prepolymerization temperature is usually −20 to 80 ° C., preferably 0 to 60 ° C., and the prepolymerization time is usually 0.5 to 100 hours, preferably 1 to 50 hours.
As the forms of the solid catalyst components (X) to (X2) used for the prepolymerization, those already described can be used without limitation. In addition, the component (γ) is used as necessary, and an organoaluminum compound represented by the above formula (III) in (γ-1) is particularly preferably used. When the component (γ) is used, the molar ratio of the aluminum atom (Αl-γ) and the transition metal compound in the component (γ) (component (γ) / transition metal compound) is usually 0.1 to 10,000. It is preferably used in an amount of 0.5 to 5000.

  The concentration of the solid catalyst components (X) to (X2) in the prepolymerization system is usually 1 to 1000 grams / liter, preferably 10 to 500 grams / liter, in a ratio of solid catalyst component / polymerization volume of 1 liter.

  The component (G) may be present in any step in the preparation of the catalyst for producing the ethylene polymer (B), and the contact order is arbitrary. Moreover, you may make it contact the prepolymerization catalyst component (XP) produced | generated by prepolymerization.

When polymerizing ethylene or ethylene and an α-olefin having 4 to 10 carbon atoms using the above-mentioned catalyst for producing an ethylene-based polymer (B), the component (α) and the component (β) are: The amount used is usually 10 ⁻¹² to 10 ⁻¹ mol, preferably 10 ⁻⁸ to 10 ⁻² mol, per liter of reaction volume.

Moreover, superposition | polymerization temperature is -50-200 degreeC normally, Preferably it is 0-170 degreeC, Most preferably, it is the range of 60-170 degreeC. The polymerization pressure is usually from normal pressure to 100 kgf / cm ² , preferably from normal pressure to 50 kgf / cm ² , and the polymerization reaction is carried out in any of batch, semi-continuous and continuous methods. Can do. Furthermore, the polymerization can be carried out in two or more stages having different reaction conditions.

  The molecular weight of the resulting ethylene polymer (B) can be adjusted by allowing hydrogen to be present in the polymerization system or changing the polymerization temperature. Further, the component (G) can be present in the polymerization system for the purpose of suppressing fouling or improving particle properties.

  In order to suppress variations in physical property values, the ethylene polymer (B) particles obtained by the polymerization reaction and other components added as desired are melted by any method and subjected to kneading, granulation, or the like. .

[Ethylene / α-olefin random copolymer (D)]
In the injection foam molded article of the present invention, for the purpose of imparting impact resistance, the density is 840 kg / m ³ or more and less than 875 kg / m ³ , one or more kinds selected from ethylene and an α-olefin having 3 to 20 carbon atoms. An ethylene / α-olefin random copolymer (D) comprising olefin may be added. The copolymer (D) has a molar ratio of ethylene to α-olefin (ethylene / α-olefin) of 95/5 to 70/30, preferably 90/10 to 75/25.

  Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and 1-decene. 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicocene and the like. These α-olefins can be used alone or in combination. Of these, propylene, 1-butene, 1-hexene and 1-octene are particularly preferable.

Copolymer (D) has a density of 840 kg / m ³ or more 875kg / m less than ^3, preferably not more 840 kg / m ³ or more 870 kg / m ³ or less. When the density of the copolymer (D) is within the above range, an injection foam molded article having excellent impact resistance can be obtained.
The copolymer (D) has an MFR at 230 ° C. and a load of 2.16 kg of usually 0.1 g / 10 min or more, preferably 0.5 to 10 g / 10 min.

[Propylene resin composition]
In the propylene resin composition according to the present invention, the propylene block copolymer (A) is 60 to 99 parts by weight, preferably 65 to 97 parts by weight, more preferably 70 to 95 parts by weight. (B) is 1 to 40 parts by weight, preferably 3 to 35 parts by weight, more preferably 5 to 30 parts by weight (provided that the total of (A) and (B) is 100 parts by weight). When the propylene-based block copolymer (A) and the ethylene-based polymer (B) are within the above ranges, the propylene-based resin composition is excellent in high melt tension, has fine foamed cells, and has high mechanical strength. In addition, an excellent injection-foamed molded article can be obtained.

  Content Ws (parts by weight) of a part (Dsol) soluble in n-decane at 23 ° C. in the propylene-based block copolymer (A) in the propylene-based resin composition, and ethylene-based in the propylene-based resin composition The weight ratio (Wb / (Ws + Wb)) to the content Wb (parts by weight) of the polymer (B) is preferably 0.15 or more and 0.85 or less, more preferably 0.20 or more and 0.80. Hereinafter, it is more preferably 0.25 or more and 0.75 or less. When the weight ratio (Wb / (Ws + Wb)) is within the above range, the dispersibility of the ethylene polymer (B) in the propylene resin composition is improved, the melt tension is improved, and fine foam cells are provided. An injection foam molding can be obtained.

  When the propylene resin composition according to the present invention includes a propylene block copolymer (A), an ethylene polymer (B), and an ethylene / α-olefin copolymer (D), the propylene resin composition is not particularly limited. The system block copolymer (A) is usually 60 to 98 parts by weight, preferably 62 to 94 parts by weight, more preferably 65 to 90 parts by weight, and the ethylene polymer (B) is usually 1 to 39 parts by weight. Parts, preferably 3 to 35 parts by weight, more preferably 5 to 30 parts by weight, and the ethylene / α-olefin copolymer (D) is usually 1 to 39 parts by weight, preferably 3 to 35 parts by weight. The amount is preferably 5 to 30 parts by weight (provided that the total of (A), (B) and (D) is 100 parts by weight). When each (co) polymer is within the above composition range, the propylene-based resin composition is excellent in high melt tension, has a fine foam cell, and obtains an injection foam molded article excellent in impact resistance. Can do.

  When the propylene-based resin composition according to the present invention contains a propylene-based block copolymer (A), an ethylene-based polymer (B), and an ethylene / α-olefin copolymer (D), the following requirements [P1] to It is preferable to satisfy [P3].

  [P1] The content Ws (parts by weight) of the part (Dsol) soluble in n-decane at 23 ° C. in the propylene-based block copolymer (A) in the propylene-based resin composition, in the propylene-based resin composition The sum (Ws + Wb + Wd) of the content Wb (parts by weight) of the ethylene polymer (B) and the content Wd (parts by weight) of the ethylene / α-olefin copolymer (D) in the propylene resin composition, 5 to 40 parts by weight, preferably 10 to 38 parts by weight, more preferably 15 to 35 parts by weight. When the sum (Ws + Wb + Wd) is within the above range, the melt tension of the propylene-based resin composition is improved, and an injection foam molded article having fine foam cells and excellent impact strength can be obtained.

  [P2] Content Wb (parts by weight) of the ethylene polymer (B) in the propylene resin composition and n-decane at 23 ° C. in the propylene block copolymer (A) in the propylene resin composition Ratio (Wb / weight) of content Ws (parts by weight) of the soluble part (Dsol) and content Wd (parts by weight) of the ethylene / α-olefin copolymer (D) in the propylene-based resin composition (Wb + Ws + Wd)) is 0.15 to 0.85, preferably 0.20 to 0.80, and more preferably 0.25 to 0.75. When the weight ratio (Wb / (Wb + Ws + Wd)) is within the above range, the dispersibility of the ethylene polymer (B) in the propylene resin composition is improved, the melt tension is improved, and fine foam cells are provided. An injection foam molding can be obtained.

  [P3] The content Ws (parts by weight) of the n-decane soluble part (Dsol) at 23 ° C. in the propylene-based block copolymer (A) in the propylene-based resin composition, and the propylene-based resin composition The weight ratio of the ethylene polymer (B) content Wb (parts by weight) to the ethylene / α-olefin copolymer (D) content Wd (parts by weight) in the propylene resin composition (Ws / (Wb + Ws + Wd)) is 0.08 to 0.92, preferably 0.10 to 0.90, and more preferably 0.15 to 0.85. When the weight ratio (Ws / (Wb + Ws + Wd)) is within the above range, the dispersibility of the ethylene polymer (B) in the propylene resin composition is improved, the melt tension is improved, and fine foam cells are provided. An injection foam molding can be obtained.

[Filler (C)]
The propylene-based resin composition according to the present invention preferably contains a filler (C) from the viewpoint of imparting rigidity to the injection-foamed molded article within a range not impairing the effects of the invention. Although content of a filler (C) is not specifically limited, Preferably it is 0.1-30 weight part with respect to 100 weight part of propylene-type resin compositions, More preferably, it is 1-25 weight part, More preferably, it is 3- 20 parts by weight.

As the filler (C), inorganic fillers such as talc, magnesium sulfate fiber, glass fiber, carbon fiber, mica, calcium carbonate, magnesium hydroxide, ammonium phosphate, silicates, carbonates, carbon black, wood flour, It is roughly classified into organic fillers such as cellulose, polyester fiber, nylon fiber, kenaf fiber, bamboo fiber, jude fiber, rice flour, starch and corn starch.
As the inorganic filler, talc, magnesium sulfate fiber, glass fiber, carbon fiber, wood powder, and cellulose are preferably used. Details will be described below.

(talc)
Talc is pulverized hydrous magnesium silicate. The crystal structure of hydrous magnesium silicate is a pyrophyllite type three-layer structure, and talc is a stack of these structures. The talc is more preferably a flat plate obtained by finely pulverizing hydrous magnesium silicate crystals to a unit layer level.

The average particle diameter of the talc is preferably 3 μm or less. Here, the average particle size of talc is equivalent to 50% obtained from an integral distribution curve of a sieving method measured by suspending talc in a dispersion medium that is water or alcohol using a centrifugal sedimentation type particle size distribution measuring device. It means particle diameter D _50. Talc may be used as it is, or various silane couplings may be used to improve interfacial adhesion with the propylene-based (block copolymer) polymer of the present invention and dispersibility in the propylene-based resin composition. The surface may be treated with an agent, a titanium coupling agent, a higher fatty acid, a higher fatty acid ester, a higher fatty acid amide, a higher fatty acid salt, or another surfactant.

(Magnesium sulfate fiber)
When magnesium sulfate fiber is used, the average fiber length is preferably 5 to 50 μm, more preferably 10 to 30 μm. Moreover, as an average fiber diameter of a magnesium sulfate fiber, Preferably it is 0.3-2 micrometers, More preferably, it is 0.5-1 micrometer. Products include Ube Industries, Ltd. “Moss Heidi”.

(Glass fiber)
As glass fibers, glass such as E glass (Electrical glass), C glass (Chemical glass), A glass (Alkali glass), S glass (High strength glass), and alkali-resistant glass is melt-spun into filamentous fibers. Can be mentioned. The glass fiber is contained in the propylene resin composition in the form of a short fiber of 1 mm or less and a long fiber of 1 mm or more.

(Carbon fiber)
The carbon fiber has a fiber diameter of more than 2 μm and 15 μm or less, preferably 3 μm to 12 μm, more preferably 4 μm to 10 μm. When the fiber diameter is 2 μm or less, the rigidity of the fiber is remarkably reduced, and when it exceeds 15 μm, the aspect ratio of the fiber (the ratio of length (L) to thickness (D): L / D) is reduced. Therefore, sufficient reinforcement efficiency such as rigidity and heat resistance cannot be obtained, which is not preferable. Here, the fiber diameter can be determined by cutting the fiber perpendicular to the fiber direction, observing the cross section under a microscope, measuring the diameter, and calculating the number average of the diameters of 100 or more fibers.

  The carbon fiber has a fiber length of usually 1 to 20 mm, preferably 2 to 15 mm, more preferably 3 to 10 mm. When the fiber length is less than 1 mm, the aspect ratio is low and sufficient reinforcement efficiency cannot be obtained. When the fiber length exceeds 20 mm, the workability and appearance are remarkably deteriorated.

Here, the fiber length can be obtained by measuring using a caliper or the like and calculating the number average of the fiber lengths of 100 or more fibers.
As the carbon fiber used in the present invention, a conventionally known carbon fiber can be used without particular limitation as long as the above-described shape is satisfied. Examples of the carbon fiber include polyacrylonitrile (PAN) -based carbon fiber using polyacrylonitrile as a raw material, and pitch-based carbon fiber using pitch as a raw material. These carbon fibers can be used as so-called chopped carbon fibers obtained by cutting a fiber yarn into a desired length, and may be converged using various sizing agents as necessary. . Since the sizing agent used for the convergence treatment needs to be melted in melt kneading with the polypropylene resin, it is preferable that the sizing agent is melted at 200 ° C. or lower.

  Specific examples of such chopped carbon fiber include PAN-based carbon fiber, trade name “TORAYCA (registered trademark)” manufactured by Toray Industries, Inc., and product name “Pyrofil (chop) manufactured by Mitsubishi Rayon Co., Ltd. ) (Registered trademark) ”, Toho Tenax Co., Ltd. product name“ Besfite (chop) (registered trademark) ”, etc., for pitch-based carbon fiber, products manufactured by Mitsubishi Chemical Corporation Name “DIALEAD (registered trademark)”, Osaka Gas Chemical Co., Ltd. product name “DonaCarbo (chop) (registered trademark)”, Kureha Chemical Co., Ltd. product name “Kureka (chop) (registered trademark)” Etc. can be mentioned.

(Wood flour)
As the wood powder, it is possible to use a material obtained by breaking wood with a cutter mill or the like and then pulverizing it with a ball mill or impeller mill to make it into a fine powder. The average particle size is usually 1 to 200 μm, preferably 10 to 150 μm. Those having an average particle size of less than 1 μm are difficult to handle, and especially when the amount of the wood-based filler is large, if the dispersion in the resin is poor, the mechanical strength of the wood-resin foamed molded article to be produced Decrease occurs. On the other hand, if it is larger than 200 μm, the homogeneity, flatness and mechanical strength of the molded product are lowered.

(cellulose)
Cellulose fibers and crystalline cellulose are preferably used as the cellulose.
The cellulose fiber is preferably a fiber having a high purity, for example, a fiber having an α-cellulose content of 80% by weight or more. As organic fibers such as cellulose fibers, fibers having an average fiber diameter of 0.1 to 1000 μm and an average fiber length of 0.01 to 5 mm can be used.

  Crystalline cellulose is a product obtained by partially depolymerizing α-cellulose obtained from a fibrous plant as a pulp and purifying it with mineral acid. As a product, “Seolas (registered trademark)” manufactured by Asahi Kasei Co., Ltd. Can be mentioned.

  When the injection-foamed molded article of the present invention is obtained by injection-foaming a propylene-based resin composition containing a propylene-based block copolymer (A), an ethylene-based polymer (B) and a filler (C), a propylene-based resin composition The content of the filler (C) is preferably 0.1 to 30 parts by weight, more preferably 1 to 25 parts by weight, and further preferably 3 to 20 parts by weight with respect to 100 parts by weight of the product. When the content of the filler (C) is within the above range, an injection foam molded article having excellent rigidity can be obtained.

(Additive)
The propylene-based resin composition can contain known additives as long as the effects of the present invention are exhibited. As additives, heat stabilizer, weather stabilizer, light stabilizer, chloride absorber, crystal nucleating agent, foaming agent, foaming aid, softener, antistatic agent, slip agent, antiblocking agent, antifogging agent, Examples include lubricants, dyes, pigments, natural oils, synthetic oils, and waxes. Examples thereof include known phenol stabilizers, organic phosphite stabilizers, thioether stabilizers, hindered amine stabilizers, higher fatty acid metal salts such as calcium stearate, inorganic oxides, and the like.

  Although the compounding quantity of an additive can be determined according to various request | requirement properties and is not restrict | limited, It is preferable that it is about 0.001-1 weight part normally with respect to 100 weight part of propylene-type resin compositions, respectively.

  As described above, the present invention is characterized by containing a relatively large amount of high molecular weight components. It is known that high molecular weight components tend to be relatively easily cut by energy such as heat, light, and shear. When molecular cutting occurs, the molecular weight distribution becomes narrow, which may cause problems such as a decrease in high-speed molding performance and difficulty in manufacturing a large molded product. Therefore, it is preferable to select an additive having a higher effect than the conventional additive and increase the amount of the additive. Among these additives, stabilizers are used for improving the stability, such as propylene block copolymer (A), ethylene polymer (B), and ethylene / α-olefin random copolymer (D). It is preferable to mix | blend with coalescence.

[Crystal nucleating agent]
A crystal nucleating agent may be added to the propylene-based resin composition according to the present invention as necessary for improving rigidity, heat resistance, and moldability.

  Examples of the crystal nucleating agent used in the present invention include sorbitol compounds such as dibenzylidene sorbitol, organophosphate compounds, rosinate compounds, aliphatic dicarboxylic acids and their metal salts, aromatic carboxylic acids and their metal salts, etc. Can be mentioned.

  Of these, organophosphate compounds are preferred. Examples of the organic phosphate ester compounds include compounds represented by the following general formula [N-1] and / or [N-2].

In the formulas [N-1] and [N-2], R ¹ is a divalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are hydrogen or 1 to 10 carbon atoms. It is a hydrocarbon group, R ² and R ³ may be the same or different, M is a 1-3 valent metal atom, n is an integer of 1-3, m is 1 or 2. Preferred metal atoms include sodium, lithium, magnesium, calcium, barium, and aluminum.

  Specific examples of the organic phosphate ester compound represented by the general formula [N-1] include sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2. , 2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, lithium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, lithium-2 , 2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2′-ethylidene-bis (4-i-propyl-6-t-butylphenyl) phosphate, lithium -2,2'-methylene-bis (4-methyl-6-tert-butylphenyl) phosphate, lithium-2,2'-methylene-bis (4-ethyl-6-tert-butyl phosphate) Nyl) phosphate, sodium-2,2′-butylidene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2′-butylidene-bis (4,6-di-t-butylphenyl) Phosphate, sodium-2,2'-t-octylmethylene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2'-t-octylmethylene-bis (4,6-di-t -Butylphenyl) phosphate, calcium-bis- (2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate), magnesium-bis [2,2'-methylene-bis (4 , 6-di-t-butylphenyl) phosphate], barium-bis [2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate] Sodium-2,2′-methylene-bis (4-methyl-6-tert-butylphenyl) phosphate, sodium-2,2′-methylene-bis (4-ethyl-6-tert-butylphenyl) phosphate Fate, sodium-2,2′-ethylidene-bis (4-m-butyl-6-tert-butylphenyl) phosphate, sodium-2,2′-methylene-bis (4,6-di-methylphenyl) phosphate Fate, sodium-2,2′-methylene-bis (4,6-di-ethylphenyl) phosphate, potassium-2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, Calcium-bis [2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate], magnesium-bis [2,2′-ethylidene -Bis (4,6-di-t-butylphenyl) phosphate], barium-bis [2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate], aluminum-tris [ 2,2′-methylene-bis (4,6-di-t-butylfel) phosphate], aluminum-tris [2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate] And a mixture of two or more of these.

A hydroxyaluminum phosphate compound represented by the general formula [N-2] is also an organophosphate compound, and in particular, R ² and R ³ are both tert-butyl groups. ] The compound represented by this is preferable.

In the formula [N-3], R ¹ is a divalent hydrocarbon group having 1 to 10 carbon atoms, and m is 1 or 2. A particularly preferred organophosphate compound is a compound represented by the general formula [N-4].

In the formula [N-4], R ¹ represents a methylene group or an ethylidene group.

  Specifically, hydroxyaluminum-bis [2,2-methylene-bis (4,6-di-t-butyl) phosphate] or hydroxyaluminum-bis [2,2-ethylidene-bis (4,6- Di-t-butyl) phosphate].

  Specific examples of the sorbitol compound include 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene sorbitol, 1,3-benzylidene-2,4- p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-methylbenzylidene-2,4 -P-ethylbenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di (p-methylbenzylidene) sorbitol, 1,3,2,4 -Di (p-ethylbenzylidene) sorbitol, 1,3,2,4-di (pn-propylbenzylyl) ) Sorbitol, 1,3,2,4-di (p-i-propylbenzylidene) sorbitol, 1,3,2,4-di (pn-butylbenzylidene) sorbitol, 1,3,2,4- Di (ps-butylbenzylidene) sorbitol, 1,3,2,4-di (pt-butylbenzylidene) sorbitol, 1,3,2,4-di (p-methoxybenzylidene) sorbitol, 1,3 , 2,4-di (p-ethoxybenzylidene) sorbitol, 1,3-benzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-benzylidene sorbitol, 1,3- p-chlorobenzylidene-2,4-p-methylbenzylidenesorbitol, 1,3-p-chlorobenzylidene-2,4-p-ethylbenzylidenesorbi 1,3-p-methylbenzylidene-2,4-p-chlorobenzylidenesorbitol, 1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidenesorbitol or 1,3,2,4-di (P-chlorobenzylidene) sorbitol and the like can be exemplified. In particular, 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di (p-methylbenzylidene) sorbitol or 1,3-p-chlorobenzylidene-2,4-p-methylbenzylidene sorbitol preferable.

  As the aliphatic dicarboxylic acid and the metal salt thereof, C4 to C12 aliphatic dicarboxylic acid and the metal salt thereof are preferable. Specifically, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, and Li , Na, Mg, Ca, Ba, Al salt and the like.

The aromatic carboxylic acid and its metal salt include benzoic acid, allyl-substituted acetic acid, aromatic dicarboxylic acid and group 1 to 3 metal salts of these periodic tables. Specifically, benzoic acid, p- Isopropyl benzoic acid, o-tertiary butyl benzoic acid, p-tertiary butyl benzoic acid, monophenylacetic acid, diphenylacetic acid, phenyldimethylacetic acid, phthalic acid, and their Li, Na, Mg, Ca, Ba, Al A salt etc. can be mentioned.
Further, as the crystal nucleating agent, a nucleating agent represented by the following formula [N-5] may be used.

In the formula [N-5], n is an integer of 0 to 2, and R ^{1 to} R ⁵ are the same or different and each may contain a hydrogen atom or a hydroxyl group, having 1 to 20 carbon atoms. An alkyl group, an alkenyl group, an alkoxy group, a carbonyl group, a halogen group, and a phenyl group, and R ⁶ is an alkyl group having 1 to 20 carbon atoms.

In the formula [N-5], n is preferably an integer of 0 to 2, R ¹ , R ² , R ⁴ and R ⁵ are each a hydrogen atom, and R ³ and R ⁶ are the same or different. And an alkyl group having 1 to 20 carbon atoms, an alkenyl group, and a halogen group, each of which may contain a hydroxyl group.

More preferably, in the formula [N-5], n is an integer of 0 to 2, R ¹ , R ² , R ⁴ and R ⁵ are each a hydrogen atom, and R ³ is —CH ₃ , _{-CH 2 CH 3, -CH 2 CH} 2 CH 3, -CH 2 CH 2 CH 2 CH 3, -CH 2 CH = CH 2, -CH (CH 3) CH = CH 2, -CH 2 CH-X 1 _{^{-CH 2 -X 2, -CH 2 CH}} -X 3 -CH 2 CH 3, a _{^{-CH 2 CH-X 4 -CH 2}} OH or _{-CH 2 OH-CH (OH)} -CH 2 OH ( where X ^{1 to} X ⁴ are each independently a halogen group.), R ⁶ is an alkyl group having 1 to 20 carbon atoms.

  Examples of the method for producing the crystal nucleating agent represented by the formula [N-5] include methods described in International Publication No. 2005/111134 pamphlet and the like. Commercially available products can also be easily obtained, for example, Mirad NX8000 (manufactured by Milliken & Company).

[Foaming agent and foaming aid]
The propylene-based resin composition according to the present invention is suitable for an injection foam molded article. The injection-molded foam is manufactured using a foaming agent.

  The foaming agent is not particularly limited as long as the effect of the present invention is exhibited, and may be a chemical foaming agent or a physical foaming agent, whether it is a solvent-type foaming agent or a decomposable foaming agent, Further, a gaseous physical foaming agent and a combination thereof may be used.

  The solvent-type foaming agent is a substance that functions as a foaming agent by being generally injected from a cylinder portion of an injection molding machine and absorbed or dissolved in a molten raw material resin, and then evaporated in an injection mold. Examples of the blowing agent include low-boiling point aliphatic hydrocarbons such as propane, butane, neopentane, heptane, isohexane, hexane, isoheptane, and heptane, and low-boiling point fluorine-containing hydrocarbons typified by Freon gas.

The decomposable foaming agent is pre-blended with the raw material resin composition and then supplied to the injection molding machine. The foaming agent decomposes under the cylinder temperature conditions of the injection molding machine to generate gases such as carbon dioxide and nitrogen gas. A compound. It may be an inorganic foaming agent or an organic foaming agent, and an organic acid such as citric acid that promotes the generation of gas or an organic acid metal salt such as sodium citrate is used as a foaming aid. You may add together as an agent.
Specific examples of the decomposable foaming agent include the following compounds.

  (1) Inorganic foaming agent: sodium bicarbonate, sodium bicarbonate, sodium carbonate, sodium bicarbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite.

  (2) Organic foaming agent: (a) N-nitroso compound: N, N′-dinitrosoterephthalamide, N, N′-dinitrosopentamethylenetetramine; (b) Azo compound: azodicarbonamide, azobisiso Butyronitrile, azocyclohexyl nitrile, azodiaminobenzene, barium azodicarboxylate; (c) sulfonyl hydrazide compound: benzene sulfonyl hydrazide, toluene sulfonyl hydrazide, p, p'-oxybis (benzenesulfenyl hydrazide), diphenyl sulfone-3 , 3′-disulfonylhydrazide; (d) azide compound: calcium azide, 4,4′-diphenyldisulfonyl azide, p-toluenesulfonyl azide.

The gaseous foaming agent is not particularly limited as long as it is a normal physical foaming agent, and examples thereof include inert gases such as carbon dioxide, nitrogen, argon, helium, neon, and astatine.
Among these, carbon dioxide, nitrogen, and argon are the most excellent because they do not need to be vaporized, are inexpensive, and have very little environmental pollution and fire hazard. Moreover, you may use a gaseous foaming agent in a supercritical state.

  These foaming agents may be used alone or in combination of two or more. And a foaming agent can also be previously mix | blended with a resin composition, and can also be inject | poured from the middle of a cylinder at the time of injection molding.

  Among these foaming agents, carbonates or bicarbonates such as sodium bicarbonate and sodium bicarbonate are preferable, and it is desirable to use an organic carboxylic acid in combination as a foaming aid. The blending ratio of carbonate or bicarbonate to organic carboxylic acid (foaming aid) is preferably in the range of 30 to 65 parts by weight of carbonate or bicarbonate and 35 to 70 parts by weight of organic carboxylic acid. Here, the total amount of both is 100 parts by weight. In addition, in using a foaming agent and a foaming auxiliary agent, the masterbatch containing them may be made beforehand, and the formulation which mix | blends it with the remaining propylene-type resin composition for foam molding may be taken.

  The addition amount of the foaming agent is selected in consideration of the amount of gas generated from the foaming agent and the desired foaming ratio depending on the required properties of the foamed molded article to be produced, but with respect to 100 parts by weight of the propylene-based resin composition. The range is usually 0.1 to 10 parts by weight, preferably 0.4 to 5.0 parts by weight, more preferably 0.7 to 3.0 parts by weight. When the addition amount of the foaming agent is within such a range, it is possible to obtain a foamed molded article in which the cell diameter is uniform and the cells are uniformly dispersed.

[Injection foam molding]
In the injection foam molding, a plasticized propylene resin composition is injected and filled into a mold cavity from an injection molding machine, and then the volume of the cavity is increased to foam the resin composition to produce a foam molded article. To do.

A mold used for injection foam molding is composed of a fixed mold and a movable mold, and these are preferably in a clamped state when the resin composition is injected and filled.
The volume of the cavity can be increased by retracting the movable mold (core back) to widen the cavity, and it is preferable to increase the volume after an injection filling, particularly after an appropriate time.

Hereinafter, a cavity structure including a fixed mold and a movable mold will be described with reference to FIGS. 1 and 2.
The initial position of the movable mold 2 (FIG. 1) is the position when the fixed mold 1 and the movable mold 2 are in the closest clamping state, and the melt of the resin composition used for one molding is A cavity having a volume almost equal to the volume filled in an unfoamed state and close to the product shape is formed.

In the present invention, the length in the expanding direction at the start of injection of the cavity 3 formed between the fixed mold 1 and the movable mold 2, that is, the cavity clearance (T ₀ ) of the mold at the start of injection is not particularly limited. The range is preferably 1.0 to 2.0 mm, more preferably 1.0 to 1.8 mm, and still more preferably 1.0 to 1.5 mm.

If the cavity clearance (T ₀ ) is less than 1.0 mm, the injection filling cavity is narrow, and the resin composition may not be sufficiently supplied and filled into the cavity due to an increase in viscosity or solidification of the resin composition.

  In addition, if injection filling is performed at a high pressure for sufficient filling, the resin is rapidly cooled by the mold, and even if the core is backed up, foaming does not occur sufficiently, resulting in poor foaming, and the generation of burrs due to high injection filling pressure is suppressed. Therefore, the equipment cost becomes high.

  The injection time of the resin composition to the mold cavity is not particularly limited, but is preferably 0.7 to 5.0 sec, more preferably about 0.7 to 4.0 sec. After completion, it is not particularly limited, but preferably has a delay time of 0 to 3 seconds, more preferably 0.5 to 3 seconds, and thereafter, the movable mold constituting the cavity is not particularly limited, but preferably 1 to 50 mm. It is desirable to enlarge the cavity volume by retreating (core back) at / sec, more preferably 1 to 20 mm / sec (FIG. 2).

  By providing the delay time, the thickness of the skin layer can be controlled. When the delay time is increased, the skin layer can be thickened, and as a result, mechanical properties such as rigidity can be increased, which is preferable.

Here, the enlargement ratio of the cavity volume is not particularly limited, but is preferably 1.1 to 4.0 times, more preferably 1.5 to 3.0 times, and still more preferably 2.0 to 2. 5 times.
Further, T ₀ and the ratio (T ₁ / T ₀₎ of the movable die 2 is expanded length of the cross-section of the cavity 3 after retraction (T ₁₎ is usually 1.1 to 5.0, preferably 1 .5 to 4.0.

When T ₁ / T ₀ is less than 1.1, it is the same as an unfoamed molded article, and a desired rigidity cannot be obtained.
The core moving speed at the time of core back varies depending on the thickness of the molded body, the type of resin, the type of foaming agent, the mold temperature, and the resin temperature, and is not particularly limited. For example, when carbon dioxide is used as the physical foaming agent, About 5-30 mm / sec is preferable.

  If the core moving speed is too slow, the resin will solidify in the middle of the core back, and sufficient foaming ratio will not be obtained, and if it is too fast, cell generation and growth will not follow the core movement, and the cell will break and the appearance will be good Can not be obtained.

  The temperature of the resin to be injected and the mold temperature vary depending on the thickness of the molded body, the type of resin, the type and amount of foaming agent, etc., but the temperatures usually used for molding propylene resins are sufficient, and the product thickness is In order to obtain a thin product or a product with a high expansion ratio, it is preferable to set it higher than the normal mold temperature. Specifically, for example, the temperature of the resin to be injected is usually 170 to 250 ° C, preferably 180 to 220 ° C. The mold temperature of the fixed mold and the movable mold is usually 10 to 100 ° C, preferably 30 to 80 ° C. The pressure inside the mold is usually 5 to 50 MPa, preferably 10 to 30 MPa. The injection pressure is usually 10 to 250 MPa, preferably 12 to 200 MPa.

  As in the present invention, after filling the cavity with the resin composition at one time and then foaming, the resin in the portion in contact with the mold is solidified faster than the internal resin, and the solid skin is not foamed on the surface of the molded product An injection foam molded article having a layer and a foam layer in the center is obtained.

  Since the injection-foamed molded product has an unfoamed solid skin layer on the surface of the molded product, it is possible to obtain and maintain a hard product shape and to obtain a highly rigid molded product. Moreover, even if some distribution occurs in the cell shape, cell density, and expansion ratio of the foam layer inside the molded body, a molded body having a good appearance can be obtained due to the smoothness and rigidity of the skin layer. The thickness of the solid skin layer is not particularly limited, but is preferably 0.1 to 0.5 mm, more preferably 0.3 to 0.5 mm. The thickness of the central foam layer is not particularly limited, but is preferably 2 to 4 mm, more preferably 1.8 to 3.5 mm. The timing of the core back for forming the skin layer having the above thickness is resin. However, it is usually preferably about 0 to 3 seconds, more preferably about 0.5 to 3 seconds after completion of injection filling. If the time from the completion of injection filling to the core back is too short, a skin layer with sufficient thickness will not be formed, and if it is too long, the resin will solidify and sufficient foaming ratio will not be obtained even if the core is back. .

  The expansion ratio can be appropriately controlled by the resin temperature, injection speed, waiting time from the end of injection filling to the start of core back, core back amount, core back speed, cooling time after the end of core back, etc. 3.0 times is preferable.

In addition, the core back can be performed in several stages, whereby a molded body in which the cell structure and the end shape are controlled is obtained.
Moreover, the expansion ratio limited to the foam layer is not particularly limited, but is preferably 2 to 6 times, and more preferably 3 to 5 times.

In the present invention, a hot runner, a shut-off nozzle (5), a valve gate (4), etc. that are used in normal injection molding can also be used.
Valve gates and hot runners not only suppress the generation of waste resin such as runners, but also have the effect of preventing the occurrence of defective foam molded products in the next cycle by the propylene resin composition leaking out of the mold into the cavity. .

  After completion of foaming, it can be cooled as it is and the foamed molded product can be taken out, or the molding cycle can be shortened by controlling the contact state between the molded product and the mold by slightly clamping, thereby promoting cooling. It is also possible to obtain a molded article having a good dent and cell shape.

In the propylene-based resin composition of the present invention, for example, an injection foam molded article having a thickness of usually about 1.2 to 5.0 mm can be suitably obtained.
When this injection-foamed molded article has closed cells, the average cell diameter is usually about 0.01 to 1.0 mm, but depending on the shape and use of the molded article, A part of the cells may be partly connected. Furthermore, the injection-foamed molded product of the present invention obtained by the above-described production method has a cross section of the molded product cut in parallel with the movable mold retreat direction, and in the region of the foamed layer center portion of 10 to 50%, “perpendicular to the solid skin layer”. The ratio of cell diameter / cell diameter along the solid skin layer is 70% or more, and the ratio of cell diameter / cell diameter is usually 0.7 to 1.4. The ratio of “diameter / cell diameter along the solid skin layer” is usually 0.1 to 0.9. In this way, if there are many cells along the skin layer, heat conduction due to radiation and convection in the foam layer can be suppressed, so the molded body should have a low thermal conductivity between the front and back sides of the molded body. Can do. In addition, when the expansion ratio is increased, the cells meet together and communicate with each other, and the inside of the molded body becomes hollow. However, since the resin pillar is formed in the cavity, the molded body is highly lightweight. And has a strong rigidity.

  Such an injection-foamed molded article can be suitably used for various applications such as automotive interior and exterior parts, substitutes such as cardboard, electrical appliances, and building materials, and is particularly suitable for automotive interior parts and automotive exterior parts. Can be used.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
In the following examples, the physical properties of the propylene copolymer, the propylene resin composition, and the ethylene polymer were measured by the following methods.

(Method for measuring physical properties of propylene-based copolymer and propylene-based resin composition)
A method for measuring physical properties of the propylene-based copolymer, the propylene-based resin composition, and the injection-foamed molded body is shown below.

(1) Melt flow rate (MFR: [g / 10 min])
Based on ASTM D1238E, it was measured with a 2.16 kg load. The measurement temperature was 230 ° C.

(2) Intrinsic viscosity ([η]: [dl / g])
Measurements were made at 135 ° C. using a Tecarin solvent.

(3) n-decane soluble (insoluble) component amount at 23 ° C. ([wt%])
About 3 g of a propylene-based block copolymer (measured to a unit of 10 ^-4 g. In addition, this weight was expressed as b (g) in the following formula), 500 ml of decane, and decane. A small amount of a heat-resistant stabilizer was charged, and the mixture was heated to 150 ° C. in 2 hours while stirring with a stirrer in a nitrogen atmosphere to dissolve the propylene-based block copolymer, and kept at 150 ° C. for 2 hours. It was gradually cooled to 23 ° C. over 8 hours. The liquid containing the obtained propylene-based block copolymer precipitate was filtered under reduced pressure using a 25G-4 standard glass filter manufactured by Iwata Glass Co., Ltd. 100 ml of the filtrate was collected and dried under reduced pressure to obtain a part of the decane-soluble component, and this weight was measured to the unit of 10 ⁻⁴ g (this weight was expressed as a (g) in the following formula. expressed). After this operation, the amount of decane soluble component was determined by the following formula.
N-decane soluble component (Dsol) content at 23 ° C. = 100 × (500 × a) / (100 × b)
N-decane insoluble component (Dinsol) content at 23 ° C. = 100−100 × (500 × a) / (100 × b)

(4) Pentad fraction (mmmm: [%])
The pentad fraction (mmmm,%), which is one of the indices of the stereoregularity of the polymer and the microtacticity thereof was investigated, was assigned to ¹³ C- based on Macromolecules 8,687 (1975) in a propylene polymer. It was calculated from the peak intensity ratio of the NMR spectrum. ^{The 13} C-NMR spectrum was measured using an EX-400 device manufactured by JEOL, based on TMS, using a temperature of 130 ° C. and an o-dichlorobenzene solvent.

(5) Content of skeleton derived from propylene and ethylene In order to measure the skeleton concentration derived from ethylene in Dsol, 20 to 30 mg of sample was added to 1,2,4-trichlorobenzene / heavy benzene (2: 1) solution 0. After dissolution in 6 ml, carbon nuclear magnetic resonance analysis ( ¹³ C-NMR) was performed. Propylene and ethylene were quantitatively determined from the dyad chain distribution. Propylene - When ethylene _{copolymer, PP = S αα, EP =} S αγ + S αβ, and _{EE = 1/2 (S βδ} + S δδ) + 1 / 4S γδ used, was determined by the following equation.
Propylene (mol%) = (PP + 1 / 2EP) × 100 / [(PP + 1 / 2EP) + (1 / 2EP + EE)
Ethylene (mol%) = (1 / 2EP + EE) × 100 / [(PP + 1 / 2EP) + (1 / 2EP + EE)

(6) Melt tension (MT: [g])
Melt tension was measured using a melt tension measuring device (manufactured by Toyo Seiki Seisakusho Co., Ltd.) with an orifice (L = 8.00 mm, D = 2.095 mm), a set temperature of 180 ° C., a piston lowering speed of 15 mm / min. It is the value which measured the winding load of the pulley with a load cell detection on conditions of speed 15m / min.

(7) Production Method and Evaluation of Injection Foam Molded Body In Examples and Comparative Examples, the production and evaluation of injection foam molded bodies were performed under the following conditions.

-Manufacturing method After preparing a propylene-based resin composition, 6 parts by weight (100 parts by weight of the propylene-based resin composition) of sodium bicarbonate-based inorganic foaming agent master batch (Polyslen EE25C manufactured by Eiwa Chemical Industry Co., Ltd.) After dry blending (so that the amount as a foaming agent was 1.8 parts by weight relative to 100 parts by weight of the resin composition), injection foam molding was performed under the following conditions to obtain an injection foam molded article.
Injection molding machine: Ube Industries, Ltd., MD350S-III type (clamping force 350t)
Mold: Cavity size: Length 400mm, width 200mm, thickness 2mm
Gate: Single point direct gate in the cavity Injection temperature: 210 ° C
Mold surface temperature: 45 ° C
Injection time: 1.0 s (time from the start of injection to the end of injection of molten resin)
Foam molding conditions Mold clearance after foaming process: 5.0mm
Core back speed: 20 mm / s
Foam start delay time after resin filling: 1 s
Injection mold cavity clearance (L0): 2mm
・ Evaluation of injection foam moldings

(6-1) Foaming ratio achievement degree It was evaluated according to the following criteria whether or not the foaming start delay time after resin filling was 2.5 times.
A: When the thickness t0 = 2 mm before foaming, the thickness t = 5 mm or more of the molded article after foaming, and when the foaming ratio 2.5 times is achieved C: When the thickness t0 = 2 mm before foaming When the thickness of the molded product after foaming is less than 5mm and the expansion ratio of 2.5 is not achieved

(6-2) Appearance of molded product The appearance of the molded product was evaluated as follows.
○: Almost no streaks occur on the surface of the molded product ×: Many streaks occur on the surface of the molded product Note that the cross section of the sample of the injection-foamed molded product is cut with a razor, and the cross section is observed with a stereomicroscope It was.

(7) Spiral flow (SFL)
Spiral flow (SFL) (injection molding flow length: [cm]) was measured using a spiral flow mold under the following injection molding conditions.

<Test piece injection molding conditions>
Injection molding machine: Nissei Plastic Industry Co., Ltd. NEX110-12E
Injection molding temperature: 180 ° C
Mold: Spiral mold (width: 10mm, thickness: 2mm)
Mold temperature: 40 ℃
Injection molding filling time: 5.5 seconds Injection molding pressure: 170 MPa
Injection molding weighing: Set so that the cushion during injection filling is 10 mm

(Method for measuring physical properties of ethylene polymer)
The measuring method of the physical property of an ethylene polymer is shown below.

(8) Melt flow rate (MFR)
The measurement was performed under the conditions of 190 ° C. and 2.16 kg load (kgf) in accordance with ASTM D1238-89.

(9) Density (d)
Based on JIS K7112, the strand obtained at the time of MFR measurement was heat-treated at 100 ° C. for 1 hour, and further allowed to stand at room temperature for 1 hour, and then measured by a density gradient tube method.

(10) Melt tension (MTα)
The melt tension (MTα) (unit: g) at 190 ° C. is determined by measuring the stress when the molten polymer is stretched at a constant speed. For the measurement, a capillary rheometer: Capillograph 1B manufactured by Toyo Seiki Seisakusho was used. The conditions are as follows: resin temperature 190 ° C., melting time 6 minutes, barrel diameter 9.55 mmφ, extrusion speed 15 mm / minute, winding speed 24 mm / minute (if the molten filament breaks, the winding speed is 5 m / minute) The nozzle diameter is 2.095 mmφ and the nozzle length is 8 mm.

(11) Shear viscosity (η ^* )
The shear viscosity [η ^* (1.0)] (P) at 200 ° C. and an angular velocity of 1.0 rad / sec was measured by the following method.

Shear viscosity (eta ^*) measures the angular velocity [omega (rad / sec)] variance of a shear viscosity at a measurement temperature of 200 ° C. (eta ^*) in the range of 0.01 ≦ ω ≦ 100. Anton Paar viscoelasticity measuring device Physica MCR301 is used for the measurement. The sample holder uses a 25 mmφ parallel plate and the sample thickness is about 2.0 mm. The number of measurement points is 5 points per ω digit. The amount of strain is appropriately selected within a range of 3 to 10% so that the torque in the measurement range can be detected and torque is not exceeded. The sample used for the shear viscosity measurement was a press molding machine manufactured by Shinfuji Metal Industry, with a preheating temperature of 190 ° C., a preheating time of 5 minutes, a heating temperature of 190 ° C., a heating time of 2 minutes, a heating pressure of 100 kgf / cm ² , and a cooling temperature of 20 It is prepared by press-molding a measurement sample to a thickness of 2 mm under the conditions of a cooling pressure of 100 kgf / cm ² at 5 ° C. and a cooling time of 5 minutes.

(12) Number of methyl branches and number of ethyl branches The measurement was performed using the AVANCE III cryo-500 type nuclear magnetic resonance apparatus manufactured by Bruker BioSpin Corporation under the following conditions.

Measurement probe: 5 mm cryoprobe (DCH type), measurement nucleus: ¹³ C (125 MHz), measurement mode: single pulse proton broadband decoupling, pulse width: 45 ° (5.00 μsec), number of points: 64 k, observation range: 250 ppm (-55 to 195 ppm), repetition time: 5.5 seconds, integration number: 256 times, measurement solvent: orthodichlorobenzene / benzene-d ₆ (4/1 v / v), sample concentration: 60 mg / 0.6 ml Measurement temperature: 120 ° C., window function: exponential (BF: 1.0 Hz), chemical shift standard: δδ signal 29.73 ppm.

The attribution of each absorption in the NMR spectrum is as follows: Chemical Domain No. 141 NMR-Review and Experiment Guide [I], p. It carried out according to 132-133. The number of methyl branches per 1,000 carbons, that is, the number of methyl branches per 1000 carbon atoms constituting the polymer chain of the ethylene-based polymer is derived from methyl branches with respect to the integral sum of absorption appearing in the range of 5 to 45 ppm. It is calculated from the integrated intensity ratio of the absorption (19.7 ppm) of the methyl group. The number of ethyl branches is calculated from the ratio of the integrated intensity of the absorption of methyl groups derived from ethyl branches (10.8 ppm) to the integrated sum of absorptions appearing in the range of 5 to 45 ppm.
The peak of the main chain methylene (29.97 ppm) was used as the chemical shift standard.

(13) Zero shear viscosity (η ₀ (P))
The zero shear viscosity [η ₀ (P)] at 200 ° C. was determined by the following method.
The shear velocity (η *) angular velocity [ω (rad / sec)] dispersion at a measurement temperature of 200 ° C. is measured in the range of 0.01 ≦ ω ≦ 100. Anton Paar viscoelasticity measuring device Physica MCR301 is used for the measurement. The sample holder was a 25 mmφ parallel plate, and the sample thickness was about 2.0 mm. The number of measurement points is 5 points per ω digit. The amount of strain is appropriately selected within a range of 3 to 10% so that the torque in the measurement range can be detected and torque is not exceeded. The sample used for the shear viscosity measurement was a press molding machine manufactured by Shinfuji Metal Industry, with a preheating temperature of 190 ° C., a preheating time of 5 minutes, a heating temperature of 190 ° C., a heating time of 2 minutes, a heating pressure of 100 kgf / cm ² , and a cooling temperature of 20 It is prepared by press-molding a measurement sample to a thickness of 2 mm under the conditions of a cooling pressure of 100 kgf / cm ² at 5 ° C. and a cooling time of 5 minutes.

The zero shear viscosity (η ₀ ) was calculated by fitting the Carreau model of the following formula (Eq-3) to a measured rheological curve [angular velocity (ω) dispersion of shear viscosity (η ^* )] by a nonlinear least square method. .
η ^* = η ₀ [1+ (λω) ^a ] ^{(n-1) / a} --- (Eq-3)

  Here, λ is a parameter having a time dimension, n is a power law index of the material, and a is a fitting parameter in the Carreau model. The fitting by the nonlinear least square method is performed so that d in the following mathematical formula (Eq-4) is minimized.

Here, η _exp (ω) represents the measured shear viscosity, and η _calc (ω) represents the shear viscosity calculated from the Carreau model.

(14) Number average molecular weight (Mn), weight average molecular weight (Mw), Z average molecular weight (Mz), molecular weight distribution (Mw / Mn, Mz / Mw)
It measured as follows using GPC-viscosity detector (GPC-VISCO) GPC / V2000 by Waters.

  Shodex AT-G is used for the guard column, two AT-806MS are used for the analytical column, a differential refractometer and a three-capillary viscometer are used for the detector, the column temperature is 145 ° C., and the mobile phase is As antioxidant, o-dichlorobenzene containing 0.3% by weight of BHT was used, the flow rate was 1.0 ml / min, and the sample concentration was 0.1% by weight. The standard polystyrene used was manufactured by Tosoh Corporation. For molecular weight calculation, the measured viscosity is calculated from a viscometer and a refractometer, and from the measured universal calibration, the number average molecular weight (Mn), weight average molecular weight (Mw), Z average molecular weight (Mz), molecular weight by GPC-VISCO method. Distribution (Mw / Mn, Mz / Mw) was determined.

(15) Molecular weight at maximum weight fraction (peak top M)
The molecular weight at the maximum weight fraction in the molecular weight distribution curve was measured as follows using a gel permeation chromatograph alliance GPC2000 (high temperature size exclusion chromatograph) manufactured by Waters.

Analysis software: Chromatography data system Empower (Waters, registered trademark)
Column; TSKgel GMH ₆ -HT × 2 + TSKgel GMH ₆ -HTL × 2 (inner diameter 7.5 mm × length 30 cm, Tosoh Corporation)
Mobile phase: o-dichlorobenzene (Wako Pure Chemicals special grade reagent)
Detector: Differential refractometer (built-in device)
Column temperature: 140 ° C
Flow rate: 1.0 mL / min Injection volume: 500 μL
Sampling time interval; 1 second Sample concentration; 0.15% (w / v)
Molecular weight calibration: Monodispersed polystyrene (Tosoh Corporation) / Molecular weight 495 to 20.6 million

  Z. Crubisic, P.M. Rempp, H.M. Benoit, J.M. Polym. Sci. , B5, 753 (1967), a molecular weight distribution curve was prepared in terms of standard polyethylene molecular weight in accordance with the procedure for general-purpose calibration. From this molecular weight distribution curve, the polymer ratio produced from the component (A) and the component (B) and the molecular weight (peak top M) at the maximum weight fraction were calculated.

(16) Intrinsic viscosity [η]
About 20 mg of a measurement sample was dissolved in 15 ml of decalin, and the specific viscosity η _sp was measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to the decalin solution for dilution, the specific viscosity η _sp was measured in the same manner. This dilution operation was further repeated twice, and the value of η _sp / C when the concentration (C) was extrapolated to 0 as shown in the following formula (Eq-6) was expressed as the intrinsic viscosity [η] (unit: dl / g ).
[Η] = lim (η _sp / C) (C → 0) -------- (Eq-6)

[Production Example 1] Production of propylene-based block copolymer (A-1) (1) Preparation of solid titanium catalyst component 95.2 g of anhydrous magnesium chloride, 442 ml of decane and 390.6 g of 2-ethylhexyl alcohol were added at 130 ° C. After carrying out a time heating reaction to obtain a homogeneous solution, 21.3 g of phthalic anhydride was added to this solution, and further stirred and mixed at 130 ° C. for 1 hour to dissolve the phthalic anhydride.

  The homogeneous solution thus obtained was cooled to room temperature, and then 75 ml of this homogeneous solution was dropped into 200 ml of titanium tetrachloride maintained at −20 ° C. over 1 hour. After charging, the temperature of the mixture was raised to 110 ° C. over 4 hours, and when it reached 110 ° C., 5.22 g of diisobutyl phthalate (DIBP) was added and stirred at the same temperature for 2 hours. Retained.

  After completion of the reaction for 2 hours, the solid part was collected by hot filtration, and the solid part was resuspended in 275 ml of titanium tetrachloride, and then heated again at 110 ° C. for 2 hours. After completion of the reaction, the solid part was again collected by hot filtration, and washed thoroughly with decane and hexane at 110 ° C. until no free titanium compound was detected in the solution.

Here, the detection of this free titanium compound was confirmed by the following method. 10 ml of the supernatant of the above solid catalyst component was collected with a syringe into a 100 ml branched Schlenk previously purged with nitrogen and charged. Next, the solvent hexane was dried in a nitrogen stream, and further vacuum-dried for 30 minutes. To this, 40 ml of ion-exchanged water and 10 ml of (1 + 1) sulfuric acid were charged and stirred for 30 minutes. This aqueous solution was transferred to a 100 ml volumetric flask through a filter paper, followed by conc. As a masking agent for iron (II) ions. Add 1 ml of H ₃ PO ₄ and 5 ml of 3% H ₂ O ₂ as a color reagent for titanium, shake the volume up to 100 ml with ion-exchanged water, and after 20 minutes, observe the absorbance at 420 nm using UV. Free titanium was washed away until this absorption was not observed.

  The solid titanium catalyst component (A) prepared as described above was stored as a decane slurry, and a part thereof was dried for the purpose of examining the catalyst composition. The composition of the solid titanium catalyst component (A) thus obtained was 2.3% by weight of titanium, 61% by weight of chlorine, 19% by weight of magnesium, and 12.5% by weight of DIBP.

(2) Production of prepolymerization catalyst 100 g of solid catalyst component, 131 mL of triethylaluminum, 37.3 mL of diethylaminotriethoxysilane, and 14.3 L of heptane were inserted into an autoclave with a stirrer having an internal volume of 20 L and maintained at an internal temperature of 15 to 20 ° C 1000 g was inserted and reacted with stirring for 120 minutes. After completion of the polymerization, the solid component was precipitated, and the supernatant was removed and washed with heptane twice. The resulting prepolymerized catalyst was resuspended in purified heptane and prepared with heptane so that the solid catalyst component concentration was 0.7 g / L.

(3) Main polymerization Propylene is 40 kg / hour, hydrogen is 107 NL / hour in a jacketed circulating tubular polymerizer with an internal capacity of 58 L, and the catalyst slurry produced in (2) is 0.46 g / hour as a solid catalyst component, triethylaluminum. 4.2 ml / hour and diethylaminotriethoxysilane 1.7 ml / hour were continuously fed, and polymerization was performed in a full liquid state without a gas phase. The temperature of the tubular polymerizer was 70 ° C., and the pressure was 3.2 MPa / G.

  The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 100 L and further polymerized. Propylene was supplied to the polymerization vessel at 15 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase portion was 2.3 mol%. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 3.1 MPa / G.

The obtained slurry was transferred to a transfer tube having an internal volume of 2.4 L, gasified and subjected to gas-solid separation, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer having an internal volume of 480 L, / Propylene block copolymerization was performed. Propylene, ethylene, and hydrogen are continuously added so that the gas composition in the gas phase polymerization vessel is ethylene / (ethylene + propylene) = 0.23 (molar ratio) and hydrogen / ethylene = 0.047 (molar ratio). Supplied. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 0.90 MPa / G.
The resulting propylene block copolymer was vacuum dried at 80 ° C.

[Production Example 2] Production of propylene-based block copolymer (A-2) In Production Example 1, (1) Preparation of a solid titanium catalyst component and (2) Production of a prepolymerized catalyst were carried out in the same manner. 3) The main polymerization was carried out by the following method.

  Propylene is 40 kg / hour, hydrogen is 152 NL / hour, and the catalyst slurry produced in (2) is 0.44 g / hour as a solid catalyst component, triethylaluminum 4.0 ml / hour Then, 1.6 ml / hour of diethylaminotriethoxysilane was continuously fed, and polymerization was carried out in a full liquid state without a gas phase. The temperature of the tubular polymerizer was 70 ° C., and the pressure was 3.3 MPa / G.

  The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 100 L and further polymerized. To the polymerization reactor, propylene was supplied at 15 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase was 4.8 mol%. Polymerization was carried out at a polymerization temperature of 70 ° C. and a pressure of 3.2 MPa / G.

The obtained slurry was transferred to a transfer pipe having an internal volume of 2.4 L, gasified and gas-solid separated, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer having an internal volume of 480 L. / Propylene block copolymerization was performed. Propylene, ethylene, and hydrogen are continuously added so that the gas composition in the gas phase polymerization reactor is ethylene / (ethylene + propylene) = 0.21 (molar ratio) and hydrogen / ethylene = 0.039 (molar ratio). Supplied. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 0.70 MPa / G.
The resulting propylene block copolymer was vacuum dried at 80 ° C.

[Production Example 3] Production of propylene-based block copolymer (A-3) In Production Example 1, (1) Preparation of a solid titanium catalyst component and (2) Production of a prepolymerized catalyst were carried out in the same manner. 3) The main polymerization was carried out by the following method.

  Propylene is 40 kg / hour, hydrogen is 126 NL / hour, and the catalyst slurry produced in (2) is 0.45 g / hour as a solid catalyst component, and triethylaluminum is 4.1 ml / hour in a jacketed circulation type tubular polymerizer having an internal volume of 58 L. Then, diethylaminotriethoxysilane (1.7 ml / hour) was continuously supplied, and polymerization was performed in a full liquid state without a gas phase. The temperature of the tubular polymerizer was 70 ° C., and the pressure was 3.3 MPa / G.

  The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 100 L and further polymerized. To the polymerization vessel, propylene was supplied at 15 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase portion was 3.3 mol%. Polymerization was carried out at a polymerization temperature of 70 ° C. and a pressure of 3.2 MPa / G.

The obtained slurry was transferred to a transfer tube having an internal volume of 2.4 L, gasified and subjected to gas-solid separation, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer having an internal volume of 480 L, / Propylene block copolymerization was performed. Propylene, ethylene, and hydrogen are continuously added so that the gas composition in the gas phase polymerization vessel is ethylene / (ethylene + propylene) = 0.21 (molar ratio) and hydrogen / ethylene = 0.12 (molar ratio). Supplied. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 0.80 MPa / G.
The resulting propylene block copolymer was vacuum dried at 80 ° C.

[Production Example 4] Production of propylene-based block copolymer (A'-1) In Production Example 1, (1) Preparation of a solid titanium catalyst component and (2) Production of a prepolymerized catalyst were carried out in the same manner. (3) The main polymerization was carried out by the following method.

  Propylene is 40 kg / hour, hydrogen is 107 NL / hour in a jacketed circulating tubular polymerizer with an internal volume of 58 L, the catalyst slurry prepared in (2) is 0.46 g / hour as a solid catalyst component, and triethylaluminum 4.2 ml / hour. Then, diethylaminotriethoxysilane (1.7 ml / hour) was continuously supplied, and polymerization was performed in a full liquid state without a gas phase. The temperature of the tubular polymerizer was 70 ° C., and the pressure was 3.2 MPa / G.

  The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 100 L and further polymerized. Propylene was supplied to the polymerization vessel at 15 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase portion was 2.3 mol%. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 3.1 MPa / G.

The obtained slurry was transferred to a transfer tube having an internal volume of 2.4 L, gasified and subjected to gas-solid separation, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer having an internal volume of 480 L, / Propylene block copolymerization was performed. Propylene, ethylene, and hydrogen are continuously added so that the gas composition in the gas phase polymerization reactor is ethylene / (ethylene + propylene) = 0.36 (molar ratio) and hydrogen / ethylene = 0.036 (molar ratio). Supplied. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 0.70 MPa / G.
The resulting propylene block copolymer was vacuum dried at 80 ° C.

[Production Example 5] Production of propylene-based block copolymer (A'-2) In Production Example 1, (1) Preparation of a solid titanium catalyst component and (2) Production of a prepolymerized catalyst were carried out in the same manner. (3) The main polymerization was carried out by the following method.

  Propylene is 40 kg / hour, hydrogen is 103 NL / hour in a jacketed circulation type tubular polymerizer having an internal volume of 58 L, the catalyst slurry produced in (2) is 0.46 g / hour as a solid catalyst component, and triethylaluminum 4.2 ml / hour. Then, diethylaminotriethoxysilane (1.7 ml / hour) was continuously supplied, and polymerization was performed in a full liquid state without a gas phase. The temperature of the tubular polymerizer was 70 ° C., and the pressure was 3.2 MPa / G.

  The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 100 L and further polymerized. Propylene was supplied to the polymerization vessel at 15 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase portion was 2.2 mol%. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 3.1 MPa / G.

The obtained slurry was transferred to a transfer tube having an internal volume of 2.4 L, gasified and subjected to gas-solid separation, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer having an internal volume of 480 L, / Propylene block copolymerization was performed. Propylene, ethylene, and hydrogen are continuously added so that the gas composition in the gas phase polymerization reactor is ethylene / (ethylene + propylene) = 0.21 (molar ratio) and hydrogen / ethylene = 0.007 (molar ratio). Supplied. Polymerization was performed at a polymerization temperature of 70 ° C. and a pressure of 1.4 MPa / G.
The resulting propylene block copolymer was vacuum dried at 80 ° C.

[Production Example 6]
(Preparation of solid carrier)
Silica gel (manufactured by Fuji Silysia Co., Ltd .: average particle size 70 μm, specific surface area 340 m ² / g, pore volume 1.3 cm ³ / g, 250 ° C. for 10 hours in a reactor with a stirrer with an internal volume of 270 liters under a nitrogen atmosphere (Dry) 10 kg was suspended in 77 liters of toluene and then cooled to 0-5 ° C. To this suspension, 19.4 liters of a toluene solution of methylaluminoxane (3.5 mmol / mL in terms of Al atom) was added dropwise over 30 minutes. At this time, the system temperature was kept at 0 to 5 ° C. Subsequently, contact was performed at 0 to 5 ° C. for 30 minutes, and then the system temperature was raised to 95 ° C. over about 1.5 hours, followed by contact at 95 ° C. for 4 hours. Thereafter, the temperature was lowered to normal temperature, the supernatant was removed by decantation, and further washed twice with toluene, and then a total amount of 115 liters of toluene slurry was prepared. When a part of the obtained slurry component was sampled and the concentration was examined, the slurry concentration was 122.6 g / L and the Al concentration was 0.62 mol / L.

(Preparation of solid catalyst component)
A reactor equipped with a stirrer having an internal volume of 200 ml was charged with 30 ml of toluene and 8.2 ml of the solid support (5.1 mmol in terms of Al atom) in a nitrogen atmosphere. Next, a toluene solution of isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride (complex number: X-1) as a transition metal complex (component β), After dropping 0.020 mmol in terms of Zr atom and contacting at an internal temperature of 20 to 25 ° C. for 1 hour, the internal temperature was raised to 95 ° C. and further contacting for 2 hours. After the temperature was lowered to 30 ° C., 0.0048 mmol of a toluene solution of dimethylsilylene (3-n-butylcyclopentadienyl) (cyclopentadienyl) zirconium dichloride was dropped as a transition metal complex (component α) in terms of Zr atoms. The system was contacted at an internal temperature of 20-30 ° C. for 1 hour. The supernatant was removed by decantation, and further washed twice with hexane, and then hexane was added to make a total volume of 50 ml to prepare a solid catalyst component slurry.

(Preparation of pre-polymerization catalyst component)
After cooling the solid catalyst component slurry obtained above to 10 ° C., 2.5 mmol of diisobutylaluminum hydride (DiBAl—H) was added. Further, ethylene was continuously fed into the system for several minutes under normal pressure. During this time, the temperature in the system was maintained at 10 to 15 ° C., and then 0.36 ml of 1-hexene was added. After the addition of 1-hexene, the system temperature was raised to 35 ° C., and 3 equivalents of ethylene was polymerized in terms of weight with respect to the solid catalyst component. Thereafter, the supernatant was removed by decantation, washed four times with hexane, and then hexane was added to make a total volume of 50 ml. Next, after raising the system temperature to 35 ° C., a hexane solution of 40 mg of Chemistat 2500 (manufactured by Sanyo Chemical Industries, Ltd., registered trademark) was added and contacted for 2 hours. Thereafter, the supernatant was removed by decantation and washed four times with hexane. Next, the hexane slurry was transferred to a glass Schlenk tube with an internal volume of 100 mL, and hexane was distilled off under reduced pressure at 25 ° C. to obtain 4.0 g of a prepolymerized catalyst component. When the composition of the obtained prepolymerization catalyst was examined, 0.52 mg of Zr atoms were contained per 1 g of the prepolymerization catalyst component.

(Manufacture of olefin polymers)
Using a fluidized bed gas phase polymerization reactor with an internal volume of 1.0 m ³ , the above prepolymerization catalyst component, ethylene, 1-hexene, etc. are continuously fed into the reactor under the following polymerization conditions. A 1-hexene copolymer was produced.

[Polymerization conditions]
Prepolymerization catalyst component: 4 g / h, ethylene; 5.5 Nm ³ / h, 1-hexene; 0.80 kg / hr, hydrogen / ethylene ratio; 18 m. r. (× 10 ⁻⁴ ), polymerization pressure; 1.4 MPa · G, ethylene partial pressure; 1.0 MPa · A, polymerization temperature; 80 ° C., gas linear velocity; 80 cm / sec, addition amount of Chemistat 2500 (registered trademark); 0.5 g / L, residence time; 6 h, polymer yield; 4.0 kg / hr.

During the polymerization reaction, the operation continued for 120 hours without occurrence of local heat spots, and the polymerization was stably stopped. There were no polymer lumps or the like in the reactor after polymerization.
To the above ethylene / 1-hexene copolymer, 850 ppm of Sumilizer GP (manufactured by Sumitomo Chemical Co., Ltd., registered trademark) and 210 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.) are added as a heat stabilizer. Using a 20 mmφ extruder, the mixture was melt-kneaded under the conditions of a preset temperature of 200 ° C. and a screw rotation speed of 100 rpm, then extruded into a strand shape and cut to obtain an ethylene polymer (B-1).

[Production Example 7]
(Catalyst preparation)
[Preparation of solid component (S-1)]
In a reactor equipped with a stirrer with an internal volume of 270 liters, silica (SiO ₂ : average particle size 70 μm, specific surface area 340 m ² / g, pore volume 1.3 cm ³ / g) as a solid carrier under a nitrogen atmosphere. g, baked at 250 ° C.) 10 kg was suspended in 77 liters of toluene, and then cooled to 0 to 5 ° C. To this suspension, 19.4 liters of a toluene solution of methylaluminoxane (3.5 mmol / mL in terms of Al atom) was added dropwise over 30 minutes. At this time, the temperature in the system was kept at 0 to 5 ° C.

  Subsequently, the mixture was reacted at 0 to 5 ° C. for 30 minutes, then heated to 95 to 100 ° C. over about 1.5 hours, and then reacted at 95 to 100 ° C. for 4 hours. Thereafter, the temperature was lowered to room temperature, the supernatant was removed by decantation, and after washing twice with toluene, a total amount of 115 liters of a solid component (S-1) toluene slurry was prepared. When a part of slurry component of the obtained solid component S-1 was collected and examined for concentration, the slurry concentration was 122.6 g / L and the Al concentration was 0.62 mol / L.

[Preparation of solid catalyst component (X-1)]
In the toluene slurry of the solid component (S-1) shown above, 12.2 liters is charged into a reactor with a stirrer with an internal volume of 114 liters under a nitrogen atmosphere so that the total amount becomes 28 liters. Toluene was added. Next, a metallocene compound represented by the following formula (component β: B-1, isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-) was introduced into a 5-liter glass reactor under a nitrogen atmosphere. 9-Fluorenyl) zirconium dichloride) 16.40 g (30.10 mmol in terms of Zr atom) was collected, dissolved in 5.0 liters of toluene, and pumped to the reactor. After contact for 1 hour at an internal temperature of 20 to 25 ° C., the internal temperature was raised to 95 ° C. and further contacted for 2 hours. After the temperature was lowered to 30 ° C., 2.58 g (Zr atom) of a metallocene compound (component α: A-1, dimethylsilylene (cyclopentadienyl) (3-n-propylcyclopentadienyl) zirconium dichloride) represented by the following formula: Toluene solution (1.0 liter in terms of 6.61 mmol) was added and contacted at a system temperature of 20 to 30 ° C. for 1 hour. The supernatant was removed by decantation and further washed three times with hexane, and then hexane was added to a total volume of 30 liters to prepare a hexane slurry of the solid catalyst component (X-1).

[Preparation of prepolymerization catalyst (XP-1)]
After cooling the hexane slurry of the solid catalyst component (X-1) obtained above to 10 ° C., 3.7 mol of diisobutylaluminum hydride (DiBAl—H) was added. Further, ethylene was continuously fed into the system for several minutes under normal pressure. During this time, the temperature in the system was maintained at 10 to 15 ° C., and then 0.10 liter of 1-hexene was added. After the addition of 1-hexene, ethylene supply was started at 1.4 kg / h, and prepolymerization was performed at a system temperature of 32 to 37 ° C. 0.06 liter of 1-hexene was added 5 times every 30 minutes after the start of prepolymerization, and when ethylene supply reached 4.3 kg 190 minutes after the start of prepolymerization, the ethylene supply was stopped. Thereafter, the supernatant was removed by decantation, washed 4 times with hexane, and then hexane was added to make the total volume 50 liters.

  Next, a hexane solution of 60.8 g of Chemistat 2500 (manufactured by Sanyo Chemical Industries, Ltd., registered trademark) was pumped into the reactor at a system temperature of 34 to 36 ° C., and subsequently at 34 to 36 ° C. for 2 hours. Reacted. Thereafter, the supernatant was removed by decantation and washed four times with hexane.

  Next, a hexane slurry was inserted into a 43 liter evaporative dryer with a stirrer under a nitrogen atmosphere, and then the pressure in the dryer was reduced to −68 kPaG over about 60 minutes, and when the pressure reached −68 kPaG, about 4. It was vacuum-dried for 3 hours to remove volatile components in hexane and the prepolymerized catalyst component. Furthermore, the pressure was reduced to −100 kPaG, and when the pressure reached −100 kPaG, vacuum drying was performed for 8 hours to obtain 6.1 kg of a prepolymerized catalyst (XP-1). A portion of the resulting prepolymerized catalyst (XP-1) was sampled and the composition was examined. As a result, 0.52 mg of Zr atom was contained per 1 g of the prepolymerized catalyst component.

[Production of ethylene polymer]
In a fluidized bed gas phase polymerization reactor having an internal volume of 1.0 m ³ , an ethylene / 1-hexene copolymer was produced using the prepolymerization catalyst (XP-1). In accordance with the following polymerization conditions, ethylene, nitrogen, 1-hexene, a prepolymerization catalyst component, and the like were continuously supplied into the reactor. The polymerization reaction product was continuously withdrawn from the reactor and dried with a drying device to obtain an ethylene polymer powder.

[Polymerization conditions]
Prepolymerization catalyst component: 5.6 g / h, ethylene partial pressure; 1.2 MPa · A, in-system 1-hexene / ethylene ratio; 0.008, hydrogen / ethylene ratio; 28.8 m. r. (× 10 ⁻⁴ ), polymerization pressure; 1.4 MPa · G, polymerization temperature; 80 ° C., gas linear velocity; 80 cm / sec, addition amount of Chemistat 2500 (registered trademark); 0.53 g / L, residence time; 5 .2 h, polymer yield; 4.6 kg / hr.

  The obtained ethylene copolymer was not blended with additives such as antioxidants, and was used under the conditions of a set temperature of 200 ° C. and a screw speed of 100 rpm using a biaxially different direction 20 mmφ extruder manufactured by Toyo Seiki Seisakusho Co., Ltd. After being melt-kneaded with, extruded into strands and cut to obtain an ethylene polymer (B-2).

[Preparation Example 1]
70 parts by weight of the propylene-based block copolymer (A-1) produced in Production Example 1, 20 parts by weight of the ethylene-based polymer (B-1) produced in Production Example 6, and talc (C-1) (JM -209 (trademark), manufactured by Asada Flour Milling Co., Ltd.) 10 parts by weight, heat-resistant stabilizer IRGANOX 1010 (trademark of Ciba-Geigy Corporation), heat-resistant stabilizer IRGAFOS168 (trademark of Ciba-Geigy Corporation) 0.1 part by weight , 0.1 parts by weight of heat stabilizer IRGANOX 1076 (trademark of Ciba Geigy Co., Ltd.) and 0.1 parts by weight of calcium stearate were mixed in a tumbler, and then melt-kneaded in a twin-screw extruder to form a pellet-shaped propylene resin composition Was prepared. Table 3 shows the physical properties of the propylene-based resin composition.

<Melting and kneading conditions>
Same-direction biaxial kneader: Product No. KZW-15, manufactured by Technobel Co., Ltd. Kneading temperature: 190 ° C
Screw rotation speed: 500rpm
Feeder rotation speed: 40 rpm

[Preparation Example 2]
In Preparation Example 1, instead of 20 parts by weight of ethylene polymer (B-1), 15 parts by weight of ethylene polymer (B-1), ethylene polymer (B-2) produced in Production Example 7 A propylene-based resin composition was prepared in the same manner as Preparation Example 1, except that the amount was 5 parts by weight. Table 3 shows the physical properties of the propylene-based resin composition.

[Preparation Example 3]
In Preparation Example 1, instead of 20 parts by weight of the ethylene polymer (B-1), 10 parts by weight of the ethylene polymer (B-1) and 10 parts by weight of the ethylene polymer (B-2) were used. In the same manner as in Preparation Example 1, a propylene-based resin composition was prepared. Table 3 shows the physical properties of the propylene-based resin composition.

[Preparation Example 4]
In Preparation Example 1, instead of 20 parts by weight of the ethylene polymer (B-1), 5 parts by weight of the ethylene polymer (B-1) and 15 parts by weight of the ethylene polymer (B-2) were used. In the same manner as in Preparation Example 1, a propylene-based resin composition was prepared. Table 3 shows the physical properties of the propylene-based resin composition.

[Preparation Example 5]
In Preparation Example 1, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1, except that 20 parts by weight of the ethylene polymer (B-2) was used instead of 20 parts by weight of the ethylene polymer (B-1). A product was prepared. Table 3 shows the physical properties of the propylene-based resin composition.

[Preparation Example 6]
65 parts by weight of a propylene-based block copolymer (A-1), 25 parts by weight of an ethylene-based polymer (B-1), 10 parts by weight of talc (C-1), 0.1 parts by weight of a heat stabilizer (IRGANOX1010), After mixing 0.1 parts by weight of a heat stabilizer (IRGAFOS168), 0.1 parts by weight of a heat stabilizer (IRGANOX1076) and 0.1 parts by weight of calcium stearate with a tumbler, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1. Prepared. Table 4 shows the physical properties of the propylene-based resin composition.

[Preparation Example 7]
In Preparation Example 6, instead of 65 parts by weight of the propylene-based block copolymer (A-1), 70 parts by weight of the propylene-based block copolymer (A-2) produced in Production Example 2 was used, and the ethylene-based polymer was used. (B-1) A propylene-based resin composition was prepared in the same manner as in Preparation Example 1 except that 25 parts by weight was changed to 20 parts by weight. Table 4 shows the physical properties of the propylene-based resin composition.

[Preparation Example 8]
80 parts by weight of a propylene-based block copolymer (A-1), 10 parts by weight of an ethylene-based polymer (B-1), 10 parts by weight of talc (C-1), 0.1 parts by weight of a heat stabilizer (IRGANOX1010), After mixing 0.1 parts by weight of a heat stabilizer (IRGAFOS168), 0.1 parts by weight of a heat stabilizer (IRGANOX1076) and 0.1 parts by weight of calcium stearate with a tumbler, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1. Prepared. Table 4 shows the physical properties of the propylene-based resin composition.

[Comparative Preparation Example 1]
In Preparation Example 6, instead of 70 parts by weight of the propylene-based block copolymer (A-1), except that 70 parts by weight of the propylene-based block copolymer (A′-1) produced in Production Example 4 was used, In the same manner as in Preparation Example 1, a propylene-based resin composition was prepared. Table 4 shows the physical properties of the propylene-based resin composition.

[Comparative Preparation Example 2]
In Preparation Example 6, instead of 70 parts by weight of the propylene-based block copolymer (A-1), except that 70 parts by weight of the propylene-based block copolymer (A′-2) produced in Production Example 5 was used, In the same manner as in Preparation Example 1, a propylene-based resin composition was prepared. Table 4 shows the physical properties of the propylene-based resin composition.

[Preparation Example 9]
70 parts by weight of propylene-based block copolymer (A-1), 15 parts by weight of ethylene-based polymer (B-1), ethylene-butene copolymer (D-1) (density: 863 kg / m ³ , Tuffmer A- 4050S, Mitsui Chemicals (trademark) 5 parts by weight, talc (C-1) 10 parts by weight, heat stabilizer (IRGANOX1010) 0.1 part by weight, heat stabilizer (IRGAFOS168) 0.1 part by weight, heat stabilizer (IRGANOX 1076) 0.1 parts by weight and 0.1 parts by weight of calcium stearate were mixed with a tumbler, and then a propylene-based resin composition was prepared in the same manner as in Preparation Example 1. Table 5 shows the physical properties of the propylene-based resin composition.

[Preparation Example 10]
In Preparation Example 9, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1, except that 10 parts by weight of the ethylene polymer (B-1) and 10 parts by weight of the ethylene-butene copolymer (D-1) were used. Was prepared. Table 5 shows the physical properties of the propylene-based resin composition.

[Preparation Example 11]
In Preparation Example 9, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1, except that 5 parts by weight of the ethylene polymer (B-1) and 15 parts by weight of the ethylene-butene copolymer (D-1) were used. Was prepared. Table 5 shows the physical properties of the propylene-based resin composition.

[Comparative Preparation Example 3]
70 parts by weight of propylene-based block copolymer (A-1), ethylene-based polymer (B′-1) (linear low-density polyethylene polymer: Evolu SP1540, Mitsui Chemicals, Inc. (registered trademark)) 20 Parts by weight, 10 parts by weight of talc (C-1), 0.1 parts by weight of heat stabilizer (IRGANOX1010), 0.1 parts by weight of heat stabilizer (IRGAFOS168), 0.1 part by weight of heat stabilizer (IRGANOX1076), stair After mixing 0.1 parts by weight of calcium phosphate with a tumbler, a propylene-based resin composition was prepared in the same manner as in Preparation Example 1. Table 6 shows the physical properties of the propylene-based resin composition.

[Comparative Preparation Example 4]
In Comparative Example 3, instead of 20 parts by weight of the ethylene polymer (B′-1), the ethylene polymer (B′-2) (Mirason 11P, manufactured by Mitsui DuPont Chemical Co., Ltd. (trademark)) (See 2) A propylene-based resin composition was prepared in the same manner as in Preparation Example 1, except that the amount was 20 parts by weight. Table 6 shows the physical properties of the propylene-based resin composition.

[Comparative Preparation Example 5]
70 parts by weight of a propylene-based block copolymer (A′-2), 20 parts by weight of an ethylene-based polymer (B′-2), 10 parts by weight of talc (C-1), 0.1 parts by weight of a heat stabilizer (IRGANOX1010) Parts, 0.1 parts by weight of heat stabilizer (IRGAFOS168), 0.1 parts by weight of heat stabilizer (IRGANOX1076), and 0.1 parts by weight of calcium stearate were mixed in a tumbler, and the propylene resin composition was the same as in Preparation Example 1. A product was prepared. Table 6 shows the physical properties of the propylene-based resin composition.

[Example 1]
69 parts by weight of the propylene-based block copolymer (A-3) produced in Production Example 3, 7 parts by weight of the ethylene-based polymer (B-1) produced in Production Example 6, and ethylene produced in Production Example 7 Polymer (B-2), talc (C-1) 11 parts by weight, heat stabilizer (IRGANOX1010) 0.1 part by weight, heat stabilizer (IRGAFOS168) 0.1 part by weight, heat stabilizer (IRGANOX1076) 0 After mixing 1 part by weight and 0.1 part by weight of calcium stearate with a tumbler, the mixture was melt-kneaded with a twin screw extruder to prepare a pellet-shaped propylene resin composition. Table 7 shows the physical properties of the propylene-based resin composition.

<Melting and kneading conditions>
Same-direction twin-screw kneader: Product number TEX-30α, manufactured by Nippon Steel Co., Ltd. Kneading temperature: 190 ° C
Feed amount: 60kg / hr
Discharge amount: 600rpm
Thereafter, using the composition, an injection foam molded article was obtained in accordance with the above production method. The evaluation results of the molded body are shown in Table 7.

[Comparative Example 1]
69 parts by weight of propylene-based block copolymer (A-3), 11 parts by weight of ethylene-butene copolymer (D-1), ethylene-butene copolymer (D-2) (density 870 kg / m ³ , Toughmer A -35070S, Mitsui Chemicals (trademark) 9 parts by weight, talc (C-1) 11 parts by weight, heat stabilizer (IRGANOX1010) 0.1 part by weight, heat stabilizer (IRGAFOS168) 0.1 part by weight, After mixing 0.1 parts by weight of a heat stabilizer (IRGANOX1076) and 0.1 parts by weight of calcium stearate with a tumbler, a propylene-based resin composition was prepared in the same manner as in Example 1. Table 7 shows the physical properties of the propylene-based resin composition.

  Thereafter, using the composition, an injection foam molded article was obtained in accordance with the above production method. The evaluation results of the molded body are shown in Table 7.

The injection-foamed molded article of the present invention is lightweight and highly rigid, has a uniform cell shape and cell density, and has a good appearance.
Moreover, since the propylene-type resin composition which concerns on this invention has high melt tension and is excellent in injection molding fluidity | liquidity, this composition can be used suitably as a material for injection foam molding.

DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Cavity 4 Valve gate 5 Injection molding machine nozzle 6 Melt of foamable resin composition T ₀ Cavity clearance T ₁ Expanding length of cross section of cavity 3 after core back

Claims (3)

60 to 99 parts by weight of a propylene block copolymer (A) that simultaneously satisfies the following requirements (a1) to (a5), and an ethylene polymer (B) 1 that simultaneously satisfies the following requirements (b1) to (b5) An injection-foamed molded article obtained by adding a foaming agent to a propylene-based resin composition containing -40 parts by weight (the sum of (A) and (B) is 100 parts by weight) and injection-foaming.
[Propylene block copolymer (A)]
(A1) 5 to 40% by weight of n-decane soluble part (Dsol) at 23 ° C. and 60 to 95% by weight of n-decane insoluble part (Dinsol) at 23 ° C. (however, Dsol And the total amount of Dinsol is 100% by weight).
(A2) The content of the skeleton derived from propylene in Dsol is 50 mol% or more and 80 mol% or less.
(A3) The intrinsic viscosity [η] of Dsol measured in decalin at 135 ° C. is 1.0 dl / g or more and 4.0 dl / g or less.
(A4) The pentad fraction (mmmm) of Dinsol is 93% or more.
(A5) The melt flow rate (MFR, 230 ° C., 2.16 kg load) of the propylene-based block copolymer (A) obtained in accordance with ASTM D1238E is 20 to 200 g / 10 min.
[Ethylene polymer (B)]
(B1) The melt flow rate (MFR, 190 ° C., 2.16 kg load) obtained in accordance with ASTM D1238-89 is 0.1 g / 10 min or more and 30 g / 10 min or less.
(B2) density of 875kg / m ³ or more 945 kg / m ³ or less.
(B3) Sum of the number of methyl branches per 1000 carbon atoms [Me (/ 1000 C)] and the number of ethyl branches [Et (/ 1000 C)] measured by ¹³ C-NMR [(Me + Et) (/ 1000 C)] Is 1.80 or less.
(B4) The ratio (η ₀ ) of zero shear viscosity [η ₀ (P)] at 200 ° C. to the 6.8th power (Mw ^6.8 ) of the weight average molecular weight measured by the GPC-viscosity detector method (GPC-VISCO). / Mw ^6.8 ) is 0.03 × 10 ⁻³⁰ or more and 7.5 × 10 ⁻³⁰ or less.
(B5) Intrinsic viscosity [[η] (dl / g)] measured in decalin at 135 ° C. and 0.776 of the weight average molecular weight measured by GPC-viscosity detector method (GPC-VISCO) (Mw ^0.776 ) ([η] / Mw ^0.776 ) is 0.90 × 10 ⁻⁴ or more and 1.65 × 10 ⁻⁴ or less.   A content Ws (parts by weight) of a portion (Dsol) soluble in n-decane at 23 ° C. in the propylene-based block copolymer (A) in the propylene-based resin composition, and in the propylene-based resin composition 2. The weight ratio (Wb / (Wb + Ws)) to the content Wb (parts by weight) of the ethylene-based polymer (B) is 0.15 or more and 0.85 or less. Injection foam moldings.   The injection-foamed molded article according to claim 1 or 2, comprising 0.1 to 30 parts by weight of filler (C) with respect to 100 parts by weight of the propylene-based resin composition.