JPWO2006054716A1 - Propylene resin extruded foam - Google Patents

Abstract

Provided is a propylene-based resin extruded foam having excellent heat insulation performance and good vibration damping performance because the average cell diameter can be reduced in a state where the expansion ratio is increased. The propylene-based resin extruded foam of the present invention is obtained by extrusion-foaming a propylene-based resin. The propylene-based resin constituting the extruded foam has a loss tangent (tan δ) at a frequency of 298 K and a frequency of 10 Hz of 0.04 to 100. A certain olefin polymer is included, the expansion ratio is 10 times or more, and the average cell diameter is less than 400 μm. By adopting such a configuration, it becomes a propylene-based resin extruded foam having both excellent heat insulation performance and vibration damping performance.

Description

  The present invention relates to a propylene-based resin extruded foam having both heat insulation performance and vibration damping performance.

  Extruded foam formed by extrusion foaming a thermoplastic resin, and extruding these thermoplastic resins from a die having a large number of small holes, focusing the extruded resin strips, fusing the outer surface to foam, The extruded foam strips formed by so-called strand extrusion are widely used as structural materials in various fields such as the construction / civil engineering field and the automobile field because they are lightweight and excellent in mechanical properties. It is applied as a heat insulating material. As such an extruded foam of a thermoplastic resin, an extruded foam made of a polyurethane resin or a polystyrene resin is known.

  However, since polyurethane resins and polystyrene resins are not necessarily excellent in recycling characteristics, there is a problem in that they cannot sufficiently comply with the Building Recycling Law (the Law Concerning Recycling of Materials Related to Construction Work). there were. In addition, since polystyrene resins are inferior in heat resistance and chemical resistance, it has been desired to provide an extruded foam using a thermoplastic resin instead of these.

  Polypropylene resins, on the other hand, have excellent mechanical properties, heat resistance, chemical resistance, electrical properties, etc., and are low-cost materials, so they are widely used in various molding fields. The body also has high industrial utility and can be expected. However, polypropylene, which is a linear resin, has been used in the past because when it melts, it suddenly drops in viscosity and decreases in strength, and it cannot easily hold foamed bubbles and is easily broken. It was difficult to obtain an extruded foam having a high closed cell ratio and a high expansion ratio, equivalent to the thermoplastic resin. In addition, it is difficult to make the average cell diameter of the foam cells (bubbles) of the obtained extrusion-molded body uniform and dense, and improvement in moldability has been desired.

  Furthermore, in the field of construction, civil engineering, automobiles, etc., in addition to heat insulation performance, vibration damping performance is also required. For example, with respect to vibration board surfaces such as automobile door panels, fender panels, ceiling panels or trunk lids. If an extruded foam can be applied, the weight can be reduced.

  Here, the heat insulation performance in the case of using an extruded foam as a heat insulating material depends on the expansion ratio and the cell diameter at a certain expansion ratio (for example, 10 times or more). That is, as for the expansion ratio, if the material wall in the extruded foam becomes thinner, the heat transfer amount becomes smaller. Therefore, the higher the expansion ratio, the better the heat insulation performance. Similarly, when the cell diameter is reduced at the same expansion ratio, the number of cell walls blocking the radiant heat is increased and heat transfer is difficult and heat insulation is improved. Therefore, the cell diameter is preferably small. In such a state where the expansion ratio is increased, if the average cell diameter is reduced and the heat insulation performance is improved, the thickness of the molded body can be reduced, and there is a derivative effect that the cost is reduced. However, while the difficulty of moldability described above exists, studies have been made on the polypropylene resin extruded foam to improve the expansion ratio and reduce the cell diameter (for example, Patent Document 1 and Patent Document 2).

Japanese Patent Laid-Open No. 9-25354 JP 2001-1384 A

  However, the conventional propylene-based resin extruded foam as disclosed in the above-mentioned patent document can achieve an improvement in the expansion ratio to some extent, but it is difficult to make the average cell diameter smaller than 400 μm. It was a hindrance to further improvement. And, for these propylene resin extruded foams that tried to improve the heat insulation performance, the vibration damping performance was not sufficient, so the provision of a propylene resin extruded foam having both heat insulation performance and vibration damping performance It was desired.

  Accordingly, an object of the present invention is to provide a propylene-based resin extruded foam having excellent heat insulation performance and good vibration damping performance because the average cell diameter can be reduced in a state where the expansion ratio is increased. .

  In order to achieve the above object, the propylene-based resin extruded foam of the present invention is a propylene-based resin extruded foam obtained by extrusion-foaming a propylene-based resin, and the propylene-based resin constituting the extruded foam has a temperature It includes an olefin polymer having a loss tangent (tan δ) of 0.04 to 100 at 298K and a frequency of 10 Hz, has an expansion ratio of 10 times or more, and an average cell diameter of less than 400 μm.

  This propylene-based resin extruded foam of the present invention has a foaming ratio of 10 times or more and an average cell diameter (bubble diameter) of less than 400 μm, and thus can form a large number of cell walls in the extruded foam, It is possible to efficiently block radiant heat from the outside. As a result, an extruded foam having excellent heat insulation performance can be provided.

Furthermore, the propylene-based resin extruded foam of the present invention is an olefin polymer (hereinafter referred to as a loss tangent (tan δ) at a temperature of 298 K and a frequency of 10 Hz) of 0.04 to 100 or less with respect to a propylene-based resin as a constituent material. In some cases, a “specific olefin polymer” may be added.
Since this specific olefin polymer does not bind to the propylene resin that is a constituent material, it is excluded from the crystal of polypropylene, which is a crystalline polymer, and as a result, a viscous substance is formed on the surface of the foam cell of the extruded foam. The specific olefin polymer is uniformly present.

In other words, the propylene-based resin that is a rigid part has a property of propagating energy, whereas a substance having a viscosity near room temperature (a specific olefin polymer) uses vibration energy as thermal energy of internal molecular motion. Therefore, it has the property of absorbing vibration energy. In order to absorb vibration, it is desirable to uniformly disperse the adhesive material on the vibration surface. The specific olefin polymer having a molecular structure close to that of the polypropylene resin on the vibration surface is polypropylene-based. Since it has a certain degree of compatibility with the resin, it is uniformly dispersed on the surface of the cell wall and efficiently absorbs vibration, and an extruded foam excellent in vibration damping performance can be provided.
Thus, the present invention can suitably provide a propylene-based resin extruded foam having both heat insulation performance and vibration damping performance.

  In addition, since the propylene resin as a constituent material is excellent in recycling performance and also has good chemical resistance and heat resistance, the extruded foam of the propylene resin of the present invention also has various performances (recycling). Performance, chemical resistance, heat resistance, etc.). Furthermore, by using a propylene-based resin that is a low-cost material, an extruded foam having the above-described effects can be provided at a low cost.

In the propylene-based resin extruded foam of the present invention, the weight ratio (a / b) between the specific olefin polymer (a) and the propylene-based resin (b) is preferably 1/100 to 80/100. .
According to this invention, the foam molding which consists of polypropylene resin by including a specific olefin polymer so that a weight ratio (a / b) may become 1/100-80/100 with respect to a constituent material. In the body, the olefin polymer is moderately dispersed on the wall surface of the foam cell, and the vibration damping performance can be improved.

  In addition, the propylene-based resin extruded foam of the present invention preferably uses the 1-butene-based copolymer of the following first aspect or second aspect as the olefin-based polymer. By using a polymer, vibration damping performance can be reliably imparted to the extruded foam.

1st aspect: 1-butene type polymer which comprises the requirements of following (1)-(3).
(1) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.01 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Crystalline resin (3) stereoregularity index {(mmmm) / (mmrr + rmmr)} defined as the peak top of the observed peak and having a melting point ( _Tm- D) of 0 to 100 ° C. is 30 or less

Second aspect: A 1-butene polymer comprising the following (1), (2) and (3 ′).
(1 ′) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.25 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Mesopentad fraction (mmmm) determined from a crystalline resin (3 ′) ¹³ C-nuclear magnetic resonance (NMR) spectrum having a melting point (T _m -D) defined as the peak top of the observed peak of 0 to 100 ° C. Is less than 73%

The propylene-based resin extruded foam of the present invention preferably has a closed cell ratio of 40% or more.
According to the present invention, since the independent foaming ratio of the propylene-based resin extruded foam is 40% or more, a large number of independent bubbles make it difficult to transfer heat, so that the heat insulation performance is further improved and the impact strength and the like are improved. An extruded foam having excellent mechanical strength and moisture resistance.

In the extruded foam of the propylene-based resin of the present invention, the average cell diameter is preferably 200 μm or less.
According to the present invention, since the average cell diameter of the propylene-based resin extruded foam is further as small as 200 μm or less, more bubble walls can be formed in the extruded foam. Become a body.

The propylene-based resin extruded foam of the present invention is preferably an extruded foamed strip bundle in which a number of extruded foam strips are bundled.
According to the present invention, the propylene-based resin extruded foam is made of an extruded foamed strip bundle in which a large number of strip extruded foams are bundled, so that the foaming ratio of the extruded foam is increased. Thus, a foamed molded article having a high foaming ratio and a sufficient thickness can be easily molded in various shapes.

The propylene-based resin extruded foam of the present invention is preferably a propylene-based multistage polymer in which the propylene-based resin constituting the foam is composed of the following (A) and (B).
(A) A propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of more than 10 dL / g or a copolymer component of propylene and an α-olefin having 2 to 8 carbon atoms, (B) 135 ° C. contained in the polymer at 5 to 20% by mass, propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent of 0.5 to 3.0 dL / g, or propylene and carbon number The copolymer component with 2-8 alpha olefins is contained in 80-95 mass% in all the polymers.

This propylene-based multistage polymer achieves a high melt tension by providing the component (A), that is, an ultrahigh molecular weight propylene polymer, and has excellent viscoelastic properties by adjusting the molecular weight distribution. It is a linear propylene polymer having viscoelastic properties.
Therefore, by using a propylene-based multistage polymer having excellent viscoelastic properties as a constituent material, a propylene-based resin extruded foam having a foaming ratio of 10 times or more and an average cell diameter of less than 400 μm (preferably 200 μm or less) is ensured. Can get to. Moreover, according to this propylene-type multistage polymer, the ratio of the closed cell in an extrusion foam can also be raised, for example, it can implement reliably that an closed cell rate shall be 40% or more.

  In the propylene-based resin extruded foam of the present invention, the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. of the propylene-based multistage polymer has the following formula (I): It is preferable.

  According to the present invention, since the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. includes the formula (I), high-magnification foam molding can be easily performed. Thus, an extruded foam having an expansion ratio of 10 times or more can be obtained easily and reliably.

In Example 2 of this invention, it is a schematic diagram which shows the morphology by which the component (b) was selectively comprised in the layer form around the bubble. In the said Example 2, it is a schematic diagram which shows the morphology in which a component (b) disperse | distributes in a component (a). It is the image which expanded and photoed the wall part between bubbles about the cross section of the foam of the said Example 2 by 13000 times with the transmission electron microscope (TEM).

  The propylene-based resin extruded foam of the present invention (hereinafter referred to as extruded foam) is an olefin-based polymer in which the propylene-based resin as a constituent material has a temperature 298K and a loss tangent (tan δ) at a frequency of 10 Hz is 0.04 to 100. A specific olefin polymer), and a propylene resin containing this specific olefin resin is extruded and foamed. The expansion ratio is 10 times or more and the average cell diameter is less than 400 μm. With such a configuration, an extruded foam having both excellent heat insulating performance and vibration damping performance can be provided.

  Further, if the independent foaming ratio of the extruded foam is 40% or more, preferably 60% or more, a large number of independent bubbles make it difficult to transfer heat, so that the heat insulation performance is further improved and the mechanical strength such as impact strength is improved. Strength and moisture resistance are excellent.

  Examples of the propylene-based resin forming the extruded foam of the present invention having such a configuration include propylene-based resins having a high melt tension at the time of melting, such as JP-A Nos. 10-279632, 2000-309670, and JP-A Propylene-based resins described in 2000-336198, JP-A-2002-12717, JP-T 2002-542360, JP-T 2002-509575, and the like can be used.

Moreover, in order to obtain the extruded foam of this invention, as above-mentioned, it is desirable to make high the melt tension at the time of a fusion | melting as a propylene-type resin, and it is preferable to use the resin material excellent in the viscoelastic characteristic.
As such a propylene-based resin having excellent viscoelastic properties, for example, a propylene-based multistage polymer composed of the following component (A) and component (B) is preferable as the propylene-based resin constituting the foam.
(A) A propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of more than 10 dL / g or a copolymer component of propylene and an α-olefin having 2 to 8 carbon atoms, (B) 135 ° C. contained in the polymer at 5 to 20% by mass, propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent of 0.5 to 3.0 dL / g, or propylene and carbon number The copolymer component with 2-8 alpha olefins is contained in 80-95 mass% in all the polymers.

  This propylene-based multistage polymer achieves a high melt tension by applying component (A), that is, an ultrahigh molecular weight propylene polymer, and a linear chain whose viscoelastic properties are adjusted by adjusting the molecular weight distribution. It is a propylene-based polymer. By using such a propylene-based multistage polymer having excellent viscoelastic properties as a constituent material, the above-described requirements of the present invention (the expansion ratio is 10 times or more and the average cell diameter is less than 400 μm (preferably 200 μm or less)). In addition, a propylene-based resin extruded foam having a closed cell ratio of 60% or more can be reliably obtained, which is preferable.

Here, when the intrinsic viscosity of the component (A) is 10 dL / g or less, the melt tension becomes insufficient and the desired foaming performance may not be obtained.
On the other hand, if the mass fraction of component (A) is less than 5% by mass, the melt tension becomes insufficient and the desired foaming performance may not be obtained. On the other hand, if the mass fraction exceeds 20% by mass. In other words, so-called melt fracture may become intense, which causes rough skin of the extruded foam and the product quality deteriorates.

As described above, the intrinsic viscosity of the component (A) is preferably more than 10 dL / g, more preferably in the range of 12 to 20 dL / g, and in the range of 13 to 18 dL / g. Is particularly preferred.
Moreover, it is preferable that the mass fraction of a component (A) exists in the range of 8-18 mass%, and it is especially preferable that it exists in the range of 10-16 mass%.

If the intrinsic viscosity of the component (B) is less than 0.5 dL / g, the melt tension may be insufficient and the desired foaming performance may not be obtained. It may be too high to perform a suitable extrusion.
Further, if the mass fraction of the component (B) is less than 80% by mass, it may be difficult to perform suitable extrusion molding. If the mass fraction exceeds 95% by mass, the melt tension becomes low. In some cases, it may be difficult to perform suitable extrusion.

As described above, the intrinsic viscosity of the component (B) is preferably in the range of 0.5 to 3.0 dL / g, preferably in the range of 0.8 to 2.0 dL / g. It is particularly preferable that it is in the range of 1.0 to 1.5 dL / g.
Moreover, it is preferable that the mass fraction of a component (B) exists in the range of 82-92 mass%, and it is especially preferable that it exists in the range of 84-90 mass%.

In the propylene-based multistage polymer, examples of the α-olefin having 2 to 8 carbon atoms constituting the copolymer component include ethylene and 1-butene which are α-olefins other than propylene. Among these, it is preferable to use ethylene.
The propylene-based multistage polymer preferably has a melt flow rate (MFR) at 230 ° C. of 100 g / 10 min or less, particularly preferably 20 g / 10 min or less. If the MFR exceeds 100 g / 10 min, the melt tension and viscosity of the multistage polymer become low, and molding may be difficult.

  In the propylene-based multistage polymer, the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. preferably includes the following formula (I).

Here, when the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. does not satisfy the formula (I), it is difficult to perform high-magnification foam molding. Thus, an extruded foam having an expansion ratio of 10 times or more may not be obtained. The constant (1.2) is preferably 1.3 or more, and particularly preferably 1.4 or more.
In addition, what is necessary is just to make it contain 5 mass% of components (A) so that a propylene type multistage polymer may have the relationship of above-mentioned Formula (I).

  The propylene-based multistage polymer has a storage elastic modulus slope on a high frequency side that is a certain amount or more as dynamic viscoelasticity in a molten state (relationship between angular frequency ω and storage elastic modulus G ′). Specifically, G is a ratio of the storage elastic modulus G ′ (10) when the angular frequency is 10 rad / s and the storage elastic modulus G ′ (1) when the angular frequency is 1 rad / s. '(10) / G' (1) is preferably 2.0 or more, and particularly preferably 2.5 or more. When the ratio G ′ (10) / G ′ (1) is less than 2.0, stability may be reduced when an external change such as stretching is applied to the extruded foam.

  Similarly, the propylene-based multistage polymer preferably has a storage elastic modulus slope on the low frequency side as a dynamic viscoelasticity in a molten state having a certain amount or less, specifically, an angular frequency. Is the ratio of the storage elastic modulus G ′ (0.1) when the angular frequency is 0.1 rad / s and the storage elastic modulus G ′ (0.01) when the angular frequency is 0.01 rad / s. 0.1) / G ′ (0.01) is preferably 6.0 or less, and particularly preferably 4.0 or less. If the ratio G ′ (0.1) / G ′ (0.01) exceeds 6.0, it may be difficult to increase the expansion ratio of the extruded foam.

Such a propylene-based multistage polymer uses an olefin polymerization catalyst composed of the following components (a) and (b) or the following components (a), (b) and (c) in a polymerization process of two or more stages. It can be produced by polymerizing propylene or copolymerizing propylene and an α-olefin having 2 to 8 carbon atoms.
(A) Solid catalyst component obtained by treating titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound with an ether compound and an electron acceptor (b) Organoaluminum compound (c) Cyclic ester compound

  Here, (a) a solid catalyst component obtained by treating titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound with an ether compound and an electron acceptor (hereinafter simply referred to as “(a) solid catalyst component”. As the organoaluminum compound for reducing titanium tetrachloride, for example, (i) alkylaluminum dihalide, specifically, methylaluminum dichloride, ethylaluminum dichloride, and n-propylaluminum dichloride (B) alkylaluminum sesquihalide, specifically, ethylaluminum sesquichloride, (ha) dialkylaluminum halide, specifically, dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminum chloride, Fine diethylaluminum bromide, (iv) trialkyl aluminum, specifically, trimethylaluminum, triethylaluminum, and triisobutylaluminum, (v) dialkyl aluminum hydride, specifically, may be mentioned diethyl aluminum hydride and the like. Here, “alkyl” is lower alkyl such as methyl, ethyl, propyl, butyl and the like. The “halide” is chloride or bromide, and the former is particularly common.

  Further, the reduction reaction with an organoaluminum compound for obtaining titanium trichloride is usually carried out in a temperature range of −60 to 60 ° C., preferably −30 to 30 ° C. If the temperature in the reduction reaction is lower than −60 ° C., a long time is required for the reduction reaction. On the other hand, if the temperature in the reduction reaction exceeds 60 ° C., excessive reduction may occur in some cases. The reduction reaction is preferably carried out in an inert hydrocarbon solvent such as pentane, heptane, octane and decane.

In addition, it is preferable to further perform ether treatment and electron acceptor treatment on titanium trichloride obtained by reduction reaction of titanium tetrachloride with an organoaluminum compound.
Examples of the ether compound preferably used in the ether treatment of titanium trichloride include, for example, diethyl ether, di-n-propyl ether, di-n-butyl ether, diisoamyl ether, dineopentyl ether, di-n-hexyl ether, Examples include ether compounds in which each hydrocarbon residue is a chain hydrocarbon having 2 to 8 carbon atoms such as di-n-octyl ether, di-2-ethylhexyl ether, methyl-n-butyl ether and ethyl-isobutyl ether. Of these, di-n-butyl ether is particularly preferred.

  As the electron acceptor used in the treatment of titanium trichloride, it is preferable to use halogen compounds of elements of Group III to Group IV and Group VIII of the Periodic Table. Specifically, titanium tetrachloride, Examples include silicon chloride, boron trifluoride, boron trichloride, antimony pentachloride, gallium trichloride, iron trichloride, tellurium dichloride, tin tetrachloride, phosphorus trichloride, phosphorus pentachloride, vanadium tetrachloride, and zirconium tetrachloride. be able to.

  When preparing the solid catalyst component (a), the treatment with the ether compound of titanium trichloride and the electron acceptor may be performed using a mixture of both treatment agents, and after the treatment with one treatment agent, the other You may make it perform the process by the processing agent of. Of these, the latter is preferred, and treatment with an electron acceptor is further preferred after ether treatment.

  Prior to treatment with the ether compound and electron acceptor, it is preferred to wash the titanium trichloride with a hydrocarbon. The ether treatment with titanium trichloride described above is performed by contacting titanium trichloride with an ether compound, and the treatment of titanium trichloride with an ether compound is performed by contacting both in the presence of a diluent. Is advantageous. As such a diluent, it is preferable to use an inert hydrocarbon compound such as hexane, heptane, octane, decane, benzene and toluene. In addition, it is preferable that the process temperature in an ether process is 0-100 degreeC. Moreover, it does not restrict | limit especially about processing time, Usually, it is performed in the range of 20 minutes-5 hours.

The amount of the ether compound used is generally 0.05 to 3.0 mol, preferably 0.5 to 1.5 mol, per mol of titanium trichloride. When the amount of the ether compound used is less than 0.05 mol, the stereoregularity of the produced polymer cannot be sufficiently improved, which is not preferable. On the other hand, if the amount of the ether compound used exceeds 3.0 mol, the stereoregularity of the polymer produced is improved, but the yield is lowered, which is not preferable. Strictly speaking, titanium trichloride treated with an organoaluminum compound or an ether compound is a composition containing titanium trichloride as a main component.
In addition, as such a solid catalyst component (a), Solvay type titanium trichloride can be suitably used.

What is necessary is just to use the same thing as an above-mentioned organoaluminum compound as an organoaluminum compound (b).
Examples of the cyclic ester compound (c) include γ-lactone, δ-lactone, ε-lactone, etc., and it is preferable to use ε-lactone.
Moreover, the olefin polymerization catalyst used for producing the propylene-based multistage polymer can be obtained by mixing the components (a) to (c) described above.

  In order to obtain a propylene-based multistage polymer, it is preferable to polymerize propylene or copolymerize propylene and an α-olefin having 2 to 8 carbon atoms in the absence of hydrogen among the two-stage polymerization methods. Here, “in the absence of hydrogen” means substantially in the absence of hydrogen, and includes not only the case where no hydrogen is present, but also the case where a very small amount of hydrogen is present (for example, about 10 molppm). . In short, even if hydrogen is contained in such an extent that the intrinsic viscosity [η] of the first-stage propylene-based polymer or propylene-based copolymer measured in a 135 ° C. tetralin solvent does not fall below 10 dL / g, It is included in the meaning of “in the presence”.

  By carrying out the polymerization of propylene or the copolymer of propylene and α-olefin in the absence of such hydrogen, the ultrahigh molecular weight propylene polymer, that is, the component (A) of the propylene multistage polymer is produced. be able to. In the absence of hydrogen, the component (A) has a raw material monomer as a polymerization temperature, preferably 20 to 80 ° C., more preferably 40 to 70 ° C., and a polymerization pressure in general, from normal pressure to 1.47 MPa, preferably 0. It is preferably produced by slurry polymerization under the condition of 39 to 1.18 MPa.

  In this production method, the component (B) of the propylene-based multistage polymer is preferably produced in the second and subsequent stages. The production conditions for component (B) are not particularly limited except that the above-described olefin polymerization catalyst is used, but the raw material monomer is preferably 20 to 80 ° C., more preferably 60 to 70 ° C. as the polymerization temperature. In general, the polymerization pressure is preferably from normal pressure to 1.47 MPa, preferably from 0.19 to 1.18 MPa, and polymerized under the presence of hydrogen as a molecular weight regulator.

  In the above-described production method, preliminary polymerization may be performed before the main polymerization. When the prepolymerization is carried out, the powder morphology can be maintained well. In general, the prepolymerization is generally a polymerization temperature, preferably 0 to 80 ° C, more preferably 10 to 60 ° C, and a polymerization amount as a solid catalyst. Preferably, 0.001 to 100 g, more preferably 0.1 to 10 g of propylene is polymerized or copolymerized with propylene and an α-olefin having 2 to 8 carbon atoms per 1 g of the component.

Further, a propylene resin as a constituent material of an extruded foam is used as a propylene resin composition, and the above-described propylene multistage polymer, a melt flow rate (MFR) at 230 ° C. of 30 g / 10 min or less, and a weight average You may make it contain the propylene polymer whose _Mw / _Mn which is ratio of molecular weight ( _Mw ) and number average molecular weight ( _Mn ) is 5.0 or less. By blending the above-mentioned propylene-based multistage polymer and other materials to obtain a resin composition, it is possible to improve the moldability of the extruded foam, increase its functionality, reduce costs, and the like.
By using this resin composition, the extruded foam has high melt tension and excellent viscoelastic properties, and the extruded foam has high foaming ratio, good surface appearance, and stretch breakage during sheet molding. The effect of preventing can be imparted.

In this resin composition, the weight ratio of the propylene polymer to the propylene multistage polymer is 6 times or more, more preferably 10 times or more. If the weight ratio is less than 8 times, the surface appearance of the extruded foam may be poor.
The melt flow rate (MFR) of the propylene polymer is preferably 30 g / 10 min or less, more preferably 15 g / 10 min or less, and particularly preferably 10 g / 10 min or less. If the MFR exceeds 30 g / 10 minutes, molding defects of the extruded foam may occur.

The _Mw / _Mn of the propylene-based polymer is preferably 5.0 or less, and particularly preferably 4.5 or less. If _Mw / _Mn exceeds 5.0, the surface appearance of the extruded foam may be deteriorated.
The propylene-based polymer can be produced by a polymerization method using a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

In this resin composition, as the dynamic viscoelasticity in a molten state (relationship between the angular frequency ω and the storage elastic modulus G ′), the slope of the storage elastic modulus on the high frequency side is a certain amount or more. Moreover, it is preferable that the slope of the storage elastic modulus on the low frequency side is a certain amount or less.
Specifically, G ′ (10), which is the ratio of the storage elastic modulus G ′ (10) when the angular frequency is 10 rad / s and the storage elastic modulus G ′ (1) when the angular frequency is 1 rad / s. ) / G ′ (1) is preferably 5.0 or more, particularly preferably 5.5 or more. When G ′ (10) / G ′ (1), which is such a ratio, is smaller than 5.0, stability may be reduced when an external change such as stretching is applied to the extruded foam.

  Further, the ratio of the storage elastic modulus G ′ (0.1) when the angular frequency is 0.1 rad / s and the storage elastic modulus G ′ (0.01) when the angular frequency is 0.01 rad / s. A certain G ′ (0.1) / G ′ (0.01) is preferably 14.0 or less, and particularly preferably 12.0 or less. If the ratio G ′ (0.1) / G ′ (0.01) exceeds 14.0, it may be difficult to increase the expansion ratio of the extruded foam.

  Here, in the case where the extruded foam is stretched, it is general that components in the range of 1 to 10 s of relaxation time cause deterioration of the stretch characteristics of the extruded foam. The greater the contribution of the relaxation time in this region, the smaller the slope of the storage elastic modulus G ′ (1) near the angular frequency ω of 1 rad / s. Therefore, as an index of this inclination, if G ′ (10) / G ′ (1), which is a ratio to the storage elastic modulus G ′ (10) when the angular frequency ω is 10 rad / s, is provided, numerical simulation and experiment As a result of analysis, it was found that the smaller this value, the greater the rupture during extrusion foaming. Therefore, in the above resin composition, it is preferable that G ′ (10) / G ′ (1) is 5.0 or more.

  In addition, a certain degree of strain hardening is required for bubble breakage at the final stage of bubble growth and bubble breakage accompanying high-speed extension deformation near the die lip in extrusion foam molding, so an appropriate relaxation time region is required. Therefore, an appropriate amount of the high molecular weight component is required, and for this purpose, the storage elastic modulus G ′ in the low frequency region must be large to some extent. Therefore, as the index, the storage elastic modulus G ′ (0.1) when the angular frequency ω is 0.1 rad / s, and the storage elastic modulus G ′ (0.01 when the angular frequency is 0.01 rad / s). When G ′ (0.1) / G ′ (0.01), which is a ratio to (), is provided, from the results of numerical simulation and experimental analysis, when this value increases, the foaming ratio decreases significantly due to bubble breakage. Was found to be. Therefore, in the above resin composition, it is preferable that G ′ (0.1) / G ′ (0.01) is 14.0 or less.

  It should be noted that the propylene-based resin constituting the extruded foam of the present invention, including this resin composition, may contain an antioxidant, a neutralizing agent, a crystal nucleus within a range that does not impede the effects of the present invention, if necessary. Agents, metal deactivators, phosphorus processing stabilizers, UV absorbers, UV stabilizers, fluorescent brighteners, metal soaps, stabilizers such as antacid absorbers or crosslinking agents, chain transfer agents, nucleating agents, lubricants, Additives such as plasticizers, fillers, reinforcing agents, pigments, dyes, flame retardants and antistatic agents can be added. What is necessary is just to determine the addition amount of these additives suitably according to the various characteristics and molding conditions which are requested | required of the extrusion foam to shape | mold.

  Moreover, when using the above-mentioned propylene-based multistage polymer excellent in melt viscoelasticity as a propylene-based resin, using a known melt-kneader in advance with the aforementioned additives added as necessary. You may make it shape | mold a desired extrusion foam after melt-kneading to make a pellet shape.

And the propylene-type resin extrusion foam of this invention is the olefin polymer (specific olefin type) whose loss tangent (tan-delta) in the temperature 298K and the frequency 10Hz is 0.04-100 for the propylene-type resin which is a constituent material. Polymer). By adding such a specific olefin polymer as a constituent material to the propylene resin, a specific olefin polymer that is a viscous substance is applied to the wall surface of the foamed cell of the extruded foam composed of the propylene resin. Since it is made to disperse | distribute uniformly, it becomes an extrusion foam excellent in the damping performance.

A specific olefin polymer has a loss tangent (ta) at a temperature of 298 K and a frequency of 10 Hz.
nδ) is 0.04 to 100, particularly preferably 0.04 to 10. If the loss tangent is 0.04 to 100, it exhibits viscous behavior, and when it is included in a propylene-based resin to form an extruded foam, excellent vibration damping performance can be exhibited. On the other hand, if the loss tangent is smaller than 0.04, sufficient vibration damping performance cannot be obtained, and if the loss tangent is larger than 100, it exhibits solid properties and does not absorb energy inside, and is a rigid propylene resin. Because it will vibrate together with this, it will also not be able to demonstrate vibration damping performance.
The loss tangent may be measured by, for example, a commercially available solid viscoelasticity measuring device (for example, DMS 6100: manufactured by Seiko Instruments Inc.).

  Moreover, such a specific olefin polymer (a) may be added so that the weight ratio (a / b) is 1/100 to 80/100 with respect to the polypropylene resin (b). It is preferable to add so that it may become 5 / 100-60 / 100. By including the olefin polymer so that the weight ratio is 1/100 to 80/100, the olefin polymer is appropriately dispersed on the wall surface of the foam cell in the foamed molded product made of polypropylene resin, and vibration damping is performed. Performance can be improved.

  As this specific olefin polymer, for example, a resin material disclosed in WO 03/070788 and WO 03/070790, a resin material disclosed in Japanese Patent No. 3255697, and the like can be used. Specific examples include a highly fluid 1-butene copolymer disclosed in WO 03/070788, or a similar 1-butene polymer.

As this 1-butene copolymer, specifically, those shown in the following first aspect or second aspect can be used. By using these, it is possible to reliably impart vibration damping performance to the extruded foam.
First, as the first aspect, the following requirements (1) to (3) are satisfied.
(1) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.01 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Crystalline resin (3) stereoregularity index {(mmmm) / (mmrr + rmmr)} defined as the peak top of the observed peak and having a melting point ( _Tm- D) of 0 to 100 ° C. is 30 or less

Moreover, this 1-butene polymer comprises the following (1 ′), (2) and (3 ′) as the second form.
(1 ′) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.25 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Mesopentad fraction (mmmm) determined from a crystalline resin (3 ′) ¹³ C-nuclear magnetic resonance (NMR) spectrum having a melting point (T _m -D) defined as the peak top of the observed peak of 0 to 100 ° C. Is less than 73%

  Among these, the 1-butene polymer of the first aspect has an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of 0.01 to 0.5 dL / g, and this intrinsic viscosity [η] is Preferably it is 0.1-0.5dL. If the intrinsic viscosity [η] is less than 0.01 dL / g, the physical properties (strength) may be reduced. On the other hand, if it exceeds 0.5 dL, the fluidity may be deteriorated.

The 1-butene polymer of the second aspect has an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of 0.25 to 0.5 dL / g, and this intrinsic viscosity [η] is preferably Is 0.3 to 0.5 dL / g.
When the intrinsic viscosity [η] is smaller than 0.25 dL / g, the molecules that connect the crystals are insufficient, and the toughness (tensile elongation at break) decreases. When the intrinsic viscosity [0.5] exceeds 0.5 dL / g, the viscosity increases excessively. In some cases, fluidity is lowered and molding defects occur.
The 1-butene polymer according to the first and second aspects described above is a crystalline resin having a melting point ( _Tm- D) of 0 to 100 ° C. with a differential scanning calorimeter (DSC) from the viewpoint of softness. Is required, and preferably 0 to 80 ° C.

In addition, melting | fusing point ( _Tm- D) is calculated | required by DSC (abbreviation of Differential Scanning Calorimetry). That is, using a differential scanning calorimeter (DSC-7: manufactured by Perkin Elmer), a 10 mg sample was held at −10 ° C. for 5 minutes under a nitrogen atmosphere, and then the melting point obtained by raising the temperature at 10 ° C./min. The peak top of the peak observed on the highest temperature side of the endothermic curve is the melting point (T _m -D) of the measurement target. Here, “crystalline resin” in this specification refers to a resin in which T _m -D is observed.

In the 1-butene polymer of the first embodiment, the stereoregularity index {(mmmm) / (mmrr + rmmr)} is 30 or less, preferably 20 or less, more preferably 15 or less. If this stereoregularity index exceeds 30, the flexibility of the viscous material may be reduced, and the vibration absorption effect may be reduced.
Here, the mesopentad fraction (mmmm) is preferably 90% or less, more preferably 85%, and particularly preferably 80% or less. When the mesopentad fraction (mmmm) exceeds 90%, the flexibility and the secondary workability may be reduced.

  The 1-butene polymer of the second embodiment has a mesopentad fraction (mmmm) of 73% or less. If the mesopentad fraction (mmmm) exceeds 73%, the physical cross-linking points become excessive, and the flexibility may decrease.

In such a 1-butene polymer, the mesopentad fraction (mmmm) was measured by “Polymer Journal, 16, 717 (1984)”, J. A. et al. “Macromol. Chem. Phys., C29, 201 (1989)” reported by Randall et al. It was determined according to the method proposed in “Marcomol. Chem. Phys., 198, 1257 (1997)” reported by Busico et al. That is, the signals of methylene group and methine group were measured using ¹³ C-nuclear magnetic resonance spectrum, and the mesopentad fraction in the poly (1-butene) molecule was determined.

The ¹³ C-nuclear magnetic resonance spectrum may be measured using the following apparatus and conditions.
Apparatus: JNM-EX400 type 13C-NMR apparatus manufactured by JEOL Ltd. Method: Complete proton decoupling method Concentration: 230 mg / ml Solvent: 90:10 (volume ratio) mixing of 1,2,4-trichlorobenzene and heavy benzene Solvent temperature: 130 ° C
Pulse width: 45 °
Pulse repetition time: 4 seconds Operation: 10,000 times

  Further, in such a 1-butene polymer, the stereoregularity index {(mmmm) / (mmrr + rmmr)} is calculated from the values obtained by measuring (mmmm), (mmrr) and (rmmr) by the method described above. do it.

In addition to the above-mentioned requirements, the 1-butene polymer of the first aspect and the second aspect has a weight average molecular tatami (M _w ) measured by the GPC method of 10,000 to 100,000. preferable. If _Mw is less than 10,000, the physical properties (strength) may decrease. On the other hand, if _Mw exceeds 100,000, the fluidity is lowered and the workability may be poor.
In addition, above-mentioned _Mw / _Mn is the value computed from the mass mean molecular weight ( _Mw ) and number average molecular weight ( _Mn ) of polystyrene conversion measured with the following apparatus and conditions by GPC method.

(GPC measuring device)
Column: TOSO GMHHR-H (S) HT
Detector: RI detector for liquid chromatogram WATERS 1500C measurement conditions

(50C measurement conditions)
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145 ° C
Flow rate: 1.0 ml / min Sample concentration: 2.2 mg / ml Injection volume: 160 microliter Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

  The 1-butene polymer of the first aspect preferably has a tensile modulus measured by a tensile test according to JIS K7113 of 500 MPa or less, and more preferably 300 MPa or less. If the tensile modulus exceeds 500 MPa, sufficient softness may not be obtained.

When the 1-butene polymer is a copolymer, it is preferably a random copolymer. The structural unit obtained from 1-butene is preferably 50% by mole or more, more preferably 70% by mole or more. When the structural unit derived from 1-butene is smaller than 50 mol%, the secondary workability may be deteriorated.
When the 1-butene polymer is a copolymer, the randomness index R obtained by the following formula (V) from the α-olefin chain is preferably 1 or less.

Here, R is an index representing randomness, and the smaller the R, the higher the isolation of the α-olefin (comonomer) and the more uniform the composition. This R is preferably 0.5 or less, and more preferably 0.2 or less.
When R is 0, there is no αα chain, and the α-olefin chain is completely isolated.

The butene content and R when the 1-butene polymer is a propylene / butene copolymer may be measured as follows.
Specifically, the butene content and R can be calculated by the following method by measuring a ¹³ C-NMR spectrum under the following measurement conditions using a JNM-EX400 type NMR apparatus manufactured by JEOL Ltd. Good.

(Measurement condition)
Sample concentration: 220 mg / NMR solution 3 ml NMR solution: 1,2,4-trichlorobenzene / benzene-d6 (90/10 vol%)
Measurement temperature: 130 ° C
Pulse width: 45 °
Pulse repetition time: 10 seconds Integration count: 4000 times

Under the above measurement conditions, PP, PB, and BB chains are C. According to the method proposed in Randall, Macromolecules, 1978, 11, 592, the signal of Sαα carbon in the ¹³ C-nuclear magnetic resonance spectrum was measured, and the PP, PB, BB dyad chain fraction in the copolymer molecular chain was measured. Asked.
The butene content and the randomness index R were determined from the following formula (W) and formula (X) from the obtained dyad chain fractions (mol%).

The butene content and R when the 1-butene polymer is an octyne / butene copolymer may be measured as follows. Specifically, the butene content and R can be calculated by the following method by measuring a ¹³ C-NMR spectrum under the following measurement conditions using a JNM-EX400 type NMR apparatus manufactured by JEOL Ltd. Good.

(Measurement condition)
Sample concentration: 220 mg / NMR solution 3 ml NMR solution: 1,2,4-trichlorobenzene / benzene-d6 (90/10 vol%)
Measurement temperature: 130 ° C
Pulse width: 45 °
Pulse repetition time: 10 seconds Integration count: 4000 times

Under the above measurement conditions, a signal of Sαα carbon in the ¹³ C-nuclear magnetic resonance spectrum was measured, and a BB chain observed at 40.8 to 40.0 ppm, an OB chain observed at 41.3 to 40.8 ppm, 42 The OO, OB, and BB dyad chain fractions in the copolymer molecular chain were determined from the peak intensity derived from the OO chain observed at .5 to 41.3 ppm.
The butene content and the randomness index R were determined from the following formula (Y) and formula (Z) from the obtained dyad chain fractions (mol%).

  The 1-butene copolymer can be easily obtained by the method for producing a 1-butene copolymer disclosed in WO 03/070788.

  The extruded foam of the present invention can be obtained by extrusion foaming the above-mentioned mixed material of the propylene-based resin and the specific olefin polymer, but as a production apparatus, the propylene-based resin is heated to a molten state, A known extrusion foaming apparatus that can be kneaded and foam-extruded while applying an appropriate shear stress can be used. Moreover, the extruder which comprises a manufacturing apparatus can also employ | adopt any of a single screw extruder or a twin screw extruder. As such an extrusion foam molding apparatus, for example, a tandem type extrusion foam molding apparatus disclosed in JP-A-2004-237729, to which two extruders are connected, may be used.

As foaming means for foaming the molded body, physical foaming in which a fluid (gas) is injected into a molten resin material at the time of molding or chemical foaming in which a foaming agent is mixed with the resin material can be employed.
As physical foaming, the fluid to be injected includes an inert gas such as carbon dioxide (carbon dioxide gas), nitrogen gas, or the like. As chemical foaming, usable foaming agents include azodicarbonamide, azobisisobutyronitrile, and the like.

In the physical foaming described above, if supercritical carbon dioxide gas or nitrogen gas is injected into the molten resin material, the average cell diameter is less than 400 μm, preferably 200 μm or less. It is preferable to form a large number of foamed cells because it can be carried out reliably.
Here, the supercritical state refers to a state in which the density of the gas and the liquid becomes equal and the two layers cannot be distinguished by exceeding the limit temperature and pressure at which the gas and the liquid can coexist, and occurs in this supercritical state. The fluid is called a supercritical fluid. Moreover, the temperature and pressure in a supercritical state are a supercritical temperature and a supercritical pressure. For example, in a carbon dioxide gas, it is 31 degreeC and 7.4 MPa, for example. The supercritical carbon dioxide gas or nitrogen gas may be injected, for example, in an amount of about 4 to 15% by mass with respect to the resin material, and may be injected into the molten resin material in the cylinder. it can.

  The shape of the extruded foam is not particularly limited, and a known shape as a structural material, for example, a known shape such as a plate shape, a columnar shape, a rectangular shape, etc., can be adopted, a columnar shape, a rectangular shape, a convex shape, A known shape such as a concave shape can be employed.

The extruded foam is formed by, for example, extruding and foaming a large number of strips from an extrusion die having a plurality of extrusion holes, and fusing the strips to each other in the longitudinal direction so as to condense a large number. It may be a foamed strip bundle. In this way, by forming an extruded foam strip converging body in which a large number of extruded foams of a strip are bundled, the foaming ratio of the extruded foam can be increased, the foaming ratio is high, and foaming has a sufficient thickness. The molded body can be easily molded in various shapes.
The production of such an extruded foamed strip bundle is known, for example, from JP-A-53-1262 in addition to Patent Document 1 and Patent Document 2 described above.

The shape of the strips constituting such an extruded foamed strip converging body depends on the shape of the extrusion holes formed in the extrusion die, and the shape of the extrusion holes can be any shape such as a circle, a rhombus, and a slit. It can be made into the shape. In molding, it is preferable that the pressure loss at the outlet of the extrusion die be 3 MPa to 50 MPa.
Moreover, the shape of the extrusion holes formed in the extrusion die may be all the same shape, or multiple types of extrusion holes may be formed in one extrusion die.
Furthermore, for example, even when a circular extrusion hole is used, a plurality of types of circular extrusion holes having different diameters may be formed as the size of the diameter.

According to the propylene-based resin extruded foam of the present invention thus obtained, the foaming ratio is 10 times or more and the average cell diameter is less than 400 μm, so that a large number of cell walls are formed in the extruded foam. Therefore, it is possible to efficiently block radiant heat from the outside, and it is possible to provide an extruded foam excellent in heat insulating performance.
The average cell diameter of the propylene-based resin extruded foam is preferably 200 μm or less, and if the average cell diameter is further reduced to 200 μm or less, more bubble walls in the extruded foam can be formed. It becomes a more excellent propylene-based extruded foam due to its heat insulation performance.

Moreover, since the loss tangent (tan δ) at a temperature of 298 K and a frequency of 10 Hz is included with respect to the propylene resin that is a constituent material, an olefin polymer that is 0.04 to 100 is included. Since the olefin polymer, which is a viscous substance, is present on the wall surface in a uniformly dispersed state, it effectively absorbs vibration and provides an extruded foam with excellent vibration damping performance. can do.
Thus, the present invention can suitably provide a propylene-based resin extruded foam having both heat insulation performance and vibration damping performance.

The propylene-based resin extruded foam of the present invention is a propylene-based resin extruded material of the present invention because the propylene-based resin as a constituent material is excellent in recycling performance and also has good chemical resistance and heat resistance. The foam also enjoys these performances (recycling performance, chemical resistance, heat resistance). Furthermore, by using a propylene-based resin that is a low-cost material, an extruded foam having the above-described effects can be provided at a low cost.
Since the extruded foam of the present invention has both excellent heat insulation performance and vibration damping performance in this way, structural materials (components such as ceilings, doors, floors, cowls, etc.) in the automotive field, and construction / civil engineering fields. It can be applied to structural materials (building materials, etc.).

  In addition, since the average cell diameter of the extruded foam of the present invention is as small as less than 400 μm (preferably 200 μm or less), if it is the same heat insulating performance as well as excellent heat insulating performance, the thickness is larger than the conventional one. Can be thinned. Therefore, for example, when it is applied to the above-described fields, a secondary effect that a living space can be made larger than that of a conventional heat insulating material can be suitably achieved.

  The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and has the configuration of the present invention and can achieve the objects and effects. It goes without saying that modifications and improvements within the scope are included in the content of the present invention. Further, the specific structure, shape, and the like in carrying out the present invention are not problematic as other structures, shapes, and the like as long as the objects and effects of the present invention can be achieved.

EXAMPLES Hereinafter, although an Example and a manufacture example are given and this invention is demonstrated more concretely, this invention is not limited to the content of an Example etc. at all.
The physical properties in the following production examples and examples were measured by the following methods.

(1) Mass fraction of the first stage propylene polymer component (component 1) and the second stage propylene polymer component (component 2):
It calculated | required from the mass balance using the flowmeter integrated value of the propylene supplied continuously at the time of superposition | polymerization.
(2) Intrinsic viscosity [η]:
Measurements were made in a 135 ° C. tetralin solvent. The intrinsic viscosity [η ₂ ] of component 2 was calculated by the following formula (II).

[Η _total ]: The intrinsic viscosity of the entire propylene polymer (dL / g)
[Η ₁ ]: Intrinsic viscosity of component 1 (dL / g)
W ₁ : Mass fraction of component 1 (mass%)
W ₂ : Mass fraction of component 2 (mass%)

(3) Melt flow rate (MFR):
According to JIS K7210, the temperature was measured at 230 ° C. and the load was measured at 2.16 kgf.
(4) Melt tension (MT):
Capillograph 1C (manufactured by Toyo Seiki Co., Ltd.) was used, and measurement was performed at a measurement temperature of 230 ° C., an extrusion speed of 10 mm / min, and a take-up temperature of 3.1 m / min. In the measurement, an orifice having a length of 8 mm and a diameter of 2.095 mm was used.

(5) Viscoelasticity measurement:
The measurement was performed with an apparatus having the following specifications. The storage elastic modulus G ′ can be obtained from the real part of the complex elastic modulus.
Apparatus: RMS-800 (Rheometrics)
Temperature: 190 ° C
Distortion: 30%
Frequency: 100 rad / s to 0.01 rad / s

[Production Example 1]
Propylene-based multistage polymer production:
(I) Preparation of prepolymerization catalyst component:
After thoroughly drying a 5-liter flask equipped with a stirrer with an internal volume of 5 liters and replacing with nitrogen gas, 4 liters of dehydrated heptane and 140 grams of diethylaluminum chloride were added, and a commercially available Solvay type titanium trichloride catalyst ( 20 g of Tosoh Finechem Co., Ltd. was added. While maintaining this at 20 ° C. with stirring, propylene was continuously introduced. After 80 minutes, stirring was stopped to obtain a pre-catalyst component in which 0.8 g of propylene was polymerized per 1 g of titanium trichloride catalyst.

(Ii) Polymerization of propylene (first stage):
A stainless steel autoclave with a stirrer with an internal volume of 10 liters was sufficiently dried and replaced with nitrogen gas, 6 liters of dehydrated heptane was added, and nitrogen in the system was replaced with propylene. Thereafter, propylene was introduced with stirring to stabilize the inside of the system at an internal temperature of 60 ° C. and a total pressure of 0.78 MPa, and then the prepolymerized catalyst component obtained in (i) was converted to 0.75 g in terms of solid catalyst. The polymerization was started by adding 50 ml of the contained heptane slurry. When the propylene was continuously supplied for 35 minutes, the polymer production amount obtained from the integrated value of the propylene flow rate was 151 g. As a result of sampling and analyzing a part thereof, the intrinsic viscosity was 14.1 dL / g. Thereafter, the internal temperature was lowered to 40 ° C. or lower, the stirring was loosened, and the pressure was released.

(Iii) Polymerization of propylene (second stage):
After depressurization, the internal temperature was again adjusted to 60 ° C., 0.15 MPa of hydrogen was added, and propylene was introduced while stirring. While continuously supplying propylene at a total pressure of 0.78 MPa, polymerization was performed at 60 ° C. for 2.8 hours. At this time, as a result of sampling and analyzing a part of the polymer, the intrinsic viscosity was 1.16 dL / g.

  After completion of the polymerization, 50 ml of methanol was added, and the temperature was lowered and the pressure was released. The entire contents were transferred to a filtration tank equipped with a filter, 100 ml of 1-butanol was added, and the mixture was stirred at 85 ° C. for 1 hour, followed by solid-liquid separation. Further, the solid part was washed twice with 6 liters of heptane at 85 ° C. and vacuum-dried to obtain 3.1 kg of a propylene polymer.

From the above results, the polymerization weight ratio in the first stage and the second stage was 12.2 / 87.8, and the intrinsic viscosity of the propylene polymerization component produced in the second stage was determined to be 1.08 dL / g.
Then, with respect to 100 parts by weight of the resulting propylene-based multistage polymer powder, 600 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as an antioxidant and 500 ppm of calcium stearate as a neutralizing agent were added. The mixture was melted and kneaded at a temperature of 230 ° C. with a lab plast mill single screw extruder (manufactured by Toyo Seiki Co., Ltd., φ20 mm) to prepare propylene polymer pellets.
Table 1 shows the physical properties and resin properties of the resulting propylene-based multistage polymer.

(Physical properties and resin properties of propylene-based multistage polymers)

[Example 1]
Manufacture of polypropylene extruded foam (extruded foam strips):
The 1-butene copolymer (a) disclosed in Example 1 of WO 03/070788 is weight ratio (to the pellet-shaped propylene-based multistage polymer (b) obtained in Production Example 1 described above. a / b) was mixed as 15/85 (85% by mass of the propylene multistage polymer and 15% by mass of the 1-butene copolymer) to obtain a molding material. Table 2 shows the 1-butene copolymer physical properties and resin properties.
For the measurement items in Table 2, the loss tangent (tan δ) at a temperature of 298 K and a frequency of 10 Hz was measured with a solid viscoelasticity measuring device (DMS 6100: manufactured by Seiko Instruments Inc.), and other items were The measurement was performed according to the method described in WO 03/70788.

(Physical properties and resin properties of 1-butene copolymer)

This molding material is provided with a tandem extrusion foaming apparatus disclosed in JP-A-2004-237729 (two single-screw extruders, a single-screw extruder having a screw diameter of φ50 mm and a single-screw extruder having a screw diameter of φ35 mm). ), And a die having a large number of circular extrusion holes (circular tube dies) gathered as a die, and a plate-like extruded foamed fine product in which a large number of extruded foams are bundled by the following method. Propylene-based resin extruded foam, which is a strip bundling body, was produced.
The foaming was performed by injecting a CO ₂ supercritical fluid with a φ50 mm single screw extruder.

That is, with a φ50 mm single screw extruder, a CO ₂ supercritical fluid was injected while melting the molding material, and the fluid was sufficiently dissolved so as to be uniform in the molten molding material, and then connected. The extruded foam was molded from a φ35 mm single screw extruder so that the resin temperature at the die outlet in the φ35 mm single screw extruder was 180 ° C. Details of the production conditions are shown below.
The resin temperature at the die outlet of the φ35 mm single screw extruder is measured with a thermocouple thermometer, and this resin temperature can be considered as the temperature of the molten resin extruded while foaming.

(Production conditions)
CO ₂ supercritical fluid: 7% by mass
Extrusion amount: 8kg / hr
Die upstream part resin pressure: 8MPa
Extrusion temperature at die outlet: 180 ° C
When the expansion ratio, the average cell diameter, and the closed cell rate of the propylene-based resin extruded foam thus obtained were measured according to the following conditions, they were 28 times, 120 μm, and 50%, respectively.

(Measurement condition)
Foaming ratio: The density was calculated by dividing the weight of the obtained foamed molded article by the volume obtained using the water casting method.
Average cell diameter: Measured according to ASTM D3576-3577.
Closed cell ratio: Measured according to ASTM D 2856.
Furthermore, for the extruded foam of Example 1, when the heat insulation performance and vibration damping performance were evaluated using a conventional method, good results can be obtained for both, and the extruded foam of the present invention has excellent heat resistance performance and It has been confirmed that it has vibration control performance.

[Examples 2 and 3]
Evaluation by MuCell injection molding machine (molding method)
The components (a) and (b) described above were blended so as to be Examples 2 and 3 and Comparative Examples 1 and 2 in Table 1, and were simply extruded and foamed from the following injection molding machines, and tested from the molded products. The piece was cut out to evaluate its foaming characteristics and vibration damping.
Molding machine: Nippon Steel, J180EL-MuCell
Injection time: 5 seconds Injection resin amount: 100g
Cylinder set temperature: 180 ° C
Foaming agent: CO ₂ supercritical fluid Gas amount: 5wt%
In addition, a correlation can be confirmed between the foam moldability by the tandem type extrusion molding apparatus of Example 1 and the foam moldability by simple extrusion from the injection molding machine of this example, and the result of this example is a general extrusion foaming. It can be judged that the foam moldability in molding is expressed.

(Vibration damping performance)
About the extruded foam of this example, when the heat insulation capacity and the vibration damping performance were evaluated using a conventional method, good evaluation results can be obtained for both, and the extruded foam of the present invention has excellent heat insulation performance and It has been confirmed that it has vibration control performance.
As shown in Table 3, since it is generally known that the tangent loss tan δ of solid viscoelasticity is a measure representing vibration damping, that is, a measure representing damping performance, the tan δ of solid viscoelasticity is expressed here. It was evaluated as an index of the damping performance of the foam. As tan δ increases, the vibration absorption capacity improves. In the extruded foam of Example 1, a large increase in tan δ was observed compared to the extruded foam of the propylene-based multistage polymer (b) obtained in Production Example 1, and the extruded foam of the present invention was excellent. It was confirmed that the vibration performance was exhibited.

(Relationship between morphology and damping performance)
Examination of morphology (crystal form) when propylene resin (a) is mixed and foamed with olefin polymer (b) having a loss tangent (tan δ) of 0.04 to 100 at a temperature of 298 ° C. and a frequency of 10 Hz. did.
The morphology of the foam varies depending on the compatibility of the component (b) with the component (a) and the molecular weight, but when the component (b) tends to bleed at the bubble interface, or bubbles are generated preferentially from the component (b). In this case, it is considered that the morphology is such that the component (b) is selectively formed in layers around the bubbles as shown in FIG. On the other hand, in the case different from the above, it is considered that the morphology is such that the component (b) is dispersed in the component (a) as shown in FIG. In any case, since the component (b) vibrates similarly with the vibration of the component (a), the vibration damping effect of the component (b) improves the damping performance. In the case of the morphology as in a), it is considered that a more effective vibration damping effect is exhibited by increasing the magnitude of the generated strain according to the vibration of the bubble wall surface.

  In FIG. 3, the result of having image | photographed 13000 times by the transmission electron microscope (TEM) about the wall part between bubbles about the cross section of the foam of Example 2 is shown. In this image, the foamed body is dyed with ruthenium tetrachloride, so that the portion made of component (a) is black. Thus, the aspect which can interrupt | block the propagation of the vibration through a component (b) effectively by the component (a) which has a damping effect can be confirmed.

(Change due to compounding ratio)
Although the damping characteristics are improved as the blending ratio of the component (a) to the component (b) is increased, if the weight ratio (a / b) exceeds 80/100, molding under the same conditions becomes difficult. Comparative Example 2 in Table 1 shows the results when the weight ratio (a / b) is 100/100. In this case, since the proportion of the component (a), which is a low melting point material, is too large, the raw material supply unit (hopper) ) To injection screw, clogging due to dissolution of component (a) occurred, making molding impossible.

  The propylene-based resin extruded foam of the present invention can be advantageously used for structural materials that require heat insulation performance and vibration control performance in the fields of construction, civil engineering, and automobiles, for example.

Claims (11)

A propylene-based resin extruded foam obtained by extrusion-foaming a propylene-based resin,
The propylene resin constituting the extruded foam contains an olefin polymer having a loss tangent (tan δ) of 0.04 to 100 at a temperature of 298 K and a frequency of 10 Hz,
The expansion ratio is 10 times or more,
A propylene-based resin extruded foam having an average cell diameter of less than 400 μm. In the propylene-based resin extruded foam according to claim 1,
A propylene resin extruded foam, wherein the weight ratio (a / b) of the olefin polymer (a) and the propylene resin (b) is 1/100 to 80/100. In the propylene-based resin extruded foam according to claim 1 or 2,
The propylene resin extruded foam, wherein the olefin polymer is a 1-butene polymer having the following (1), (2) and (3).
(1) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.01 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Crystalline resin (3) stereoregularity index {(mmmm) / (mmrr + rmmr)} defined as the peak top of the observed peak and having a melting point ( _Tm- D) of 0 to 100 ° C. is 30 or less In the propylene-based resin extruded foam according to claim 1 or 2,
The propylene resin extruded foam, wherein the olefin polymer is a 1-butene polymer having the following (1 '), (2) and (3').
(1 ′) Intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.25 to 0.5 dL / g
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Mesopentad fraction (mmmm) determined from a crystalline resin (3 ′) ¹³ C-nuclear magnetic resonance (NMR) spectrum having a melting point (T _m -D) defined as the peak top of the observed peak of 0 to 100 ° C. Is less than 73% In the propylene-based resin extruded foam according to any one of claims 1 to 4,
A propylene-based resin extruded foam having a closed cell ratio of 40% or more. In the propylene-based resin extruded foam according to any one of claims 1 to 5,
The propylene-based resin extruded foam, wherein the average cell diameter is 200 μm or less. In the propylene-based resin extruded foam according to any one of claims 1 to 6,
A propylene-based resin extruded foam characterized in that it is an extruded foam strip bundle in which a large number of extruded foam strips are bundled. In the propylene-based resin extruded foam according to any one of claims 1 to 7,
A propylene-based resin extruded foam, wherein the propylene-based resin constituting the extruded foam is a propylene-based multistage polymer comprising the following (A) and (B).
(A) A propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of more than 10 dL / g or a copolymer component of propylene and an α-olefin having 2 to 8 carbon atoms, (B) 135 ° C. contained in the polymer at 5 to 15% by mass, propylene homopolymer component having intrinsic viscosity [η] measured in tetralin solvent of 0.5 to 3.0 dL / g or propylene and carbon number The copolymer component with 2-8 alpha olefins is contained in 85-95 mass% in all the polymers. In the propylene-based resin extruded foam according to claim 8,
The propylene-based resin extruded foam, wherein the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. of the propylene-based multistage polymer comprises the following formula (I): .
In the propylene-based resin extruded foam according to any one of claims 1 to 7,
A propylene-based resin extruded foam, wherein the propylene-based resin constituting the extruded foam is a propylene-based multistage polymer comprising the following (A) and (B).
(A) A propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of more than 10 dL / g or a copolymer component of propylene and an α-olefin having 2 to 8 carbon atoms, (B) 135 ° C. contained in the polymer at 5 to 20% by mass, propylene homopolymer component having an intrinsic viscosity [η] measured in a tetralin solvent of 0.5 to 3.0 dL / g, or propylene and carbon number The copolymer component with 2-8 alpha olefins is contained in 80-95 mass% in all the polymers. In the propylene-based resin extruded foam according to claim 10,
The propylene-based resin extruded foam, wherein the relationship between the melt flow rate (MFR) at 230 ° C. and the melt tension (MT) at 230 ° C. of the propylene-based multistage polymer comprises the following formula (I): .