JP2009235241A - Thermoplastic elastomer composition, foam and method for producing foam - Google Patents

Abstract

Fluidity, rubber elasticity, and high foaming ratio, high closed cell property, uniform foamed cell shape, and capable of obtaining a foam having excellent rubber elasticity, flexibility, and surface appearance. Provided is a thermoplastic elastomer composition having excellent foamability.
(A) An oil-extended ethylene copolymer containing 100 parts by mass of a specific ethylene copolymer and 50 to 150 parts by mass of a mineral oil-based softener, and (B) (B-1) heat. (C-2) obtained by dynamically heat-treating a mixture containing at least one of a plastic resin and (B-2) a thermoplastic resin composition in the presence of (C) a crosslinking agent, at a take-up speed of 2.0 m / A thermoplastic elastomer composition having a melt tension at min of 5.0 cN or more and a compression set of 80% or less measured at 70 ° C. for 22 hours in accordance with JIS K6262.
[Selection figure] None

Description

  The present invention relates to a thermoplastic elastomer composition and a method for producing the same, and a foam and a method for producing the same. More specifically, a thermoplastic elastomer composition capable of producing a foam having high foaming ratio, high closed cell property and uniform foamed cell shape, and excellent rubber elasticity, flexibility, and surface appearance, and a method for producing the same And a foam and a method for producing the same.

  In recent years, foam molded products have been used in many product fields as cushioning materials and soft tactile components for vibration and noise of automobile interior parts, exterior parts, home appliances, or information equipment. In particular, thermoplastic elastomer compositions are attracting attention as raw materials that are easy to mold and foam easily. An example of such a thermoplastic elastomer composition is a thermoplastic elastomer composition that can be dynamically crosslinked (see, for example, Patent Document 1). It is known that a foam can be obtained using this thermoplastic elastomer composition.

  However, it is difficult to uniformly foam the crosslinked rubber component contained in such a dynamically crosslinkable thermoplastic elastomer composition, and only the crystalline polyolefin foams uniformly, and the foamed molded product is heterogeneous as a whole. become. Further, since the foaming gas escapes from the surface of the molded product, the expansion ratio is low, the surface is not smooth, and the surface appearance is poor. Moreover, in the non-crosslinked type, since the obtained foam does not have a crosslinked structure, there are problems such as large permanent set due to compression.

  On the other hand, a composition for an olefin-based resin foam whose melt tension is a predetermined value is disclosed (for example, see Patent Document 2). According to this olefin resin foam composition, it is said that a foam excellent in flexibility and cushioning properties can be obtained. However, even such an olefin resin foam composition still has room for improvement in its flexibility and moldability. In addition, there is a demand from the industry to develop a material composition capable of obtaining a foam having a higher closed cell property and a uniform foamed cell shape and having excellent rubber elasticity and flexibility.

JP-A-6-73222 JP 2004-250529 A

  The present invention has been made in view of such problems of the prior art, and the problem is that the foaming ratio is high, the closed cell property is high, the foamed cell shape is uniform, and the rubber elasticity To provide a thermoplastic elastomer composition excellent in fluidity, rubber elasticity, and foamability, and a method for producing the same, capable of obtaining a foam excellent in flexibility, softening material retention, and surface appearance It is in.

  Further, the subject of the present invention is a foam having a high foaming ratio, a high closed cell property and a uniform foamed cell shape, and excellent rubber elasticity, flexibility, softening material retention, and surface appearance, It is also intended to provide a manufacturing method thereof.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors dynamically cross-linked a mixture containing a specific oil-extended ethylene-based copolymer having a narrow molecular weight distribution and a thermoplastic resin. Has been found to be possible to achieve the present invention.

  That is, according to the present invention, the following thermoplastic elastomer composition, a method for producing a thermoplastic elastomer composition, a foam, and a method for producing a foam are provided.

[1] (A) An ethylene copolymer that satisfies the following conditions (1) and (2), and 50 to 150 parts by mass of a mineral oil-based softening material with respect to 100 parts by mass of the ethylene copolymer. A mixture containing an oil-extended ethylene copolymer and (B) (B-1) a thermoplastic resin and (B-2) a thermoplastic resin composition, and (C) in the presence of a crosslinking agent. Obtained by dynamic heat treatment at 210 ° C., melt tension at a take-up speed of 2.0 m / min is 5.0 cN or more, and compression set is 80% measured at 70 ° C. for 22 hours in accordance with JIS K6262. A thermoplastic elastomer composition which is:
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g.
(2): The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3 or less.

  [2] The above [1], wherein the (A) oil-extended ethylene copolymer is obtained by desolvation from a mixed solution containing the ethylene copolymer, the mineral oil-based softening material, and a solvent. The thermoplastic elastomer composition described in 1.

  [3] The thermoplastic elastomer according to [1] or [2], wherein the (B-1) thermoplastic resin is an olefin resin, and the (B-2) thermoplastic resin composition is an olefin resin composition. Composition.

  [4] The melt tension of the (B-1) thermoplastic resin at 210 ° C. and a take-up speed of 2.0 m / min is 3.0 cN or more, and the (B-2) thermoplastic resin composition has a 210 ° C. The thermoplastic elastomer composition according to any one of [1] to [3], wherein the melt tension at a take-up speed of 2.0 m / min is 3.0 cN or more.

  [5] At least one of the (B) (B-1) thermoplastic resin and the (B-2) thermoplastic resin composition has a melt tension of 3.0 cN or more at 210 ° C. and a take-up speed of 2.0 m / min. The thermoplastic elastomer composition according to any one of [1] to [4], wherein the compression set measured at 70 ° C. for 22 hours is 60% or less in accordance with JIS K6262.

  [6] Any of [1] to [5], wherein the (B-1) thermoplastic resin is at least one of an α-olefin-based crystalline thermoplastic resin and an α-olefin-based amorphous thermoplastic resin. A thermoplastic elastomer composition according to claim 1.

  [7] The (B-2) thermoplastic resin composition comprises at least one of an α-olefin-based crystalline thermoplastic resin and an α-olefin-based amorphous thermoplastic resin, and a hydrogenated diene-based polymer. The thermoplastic elastomer composition according to any one of [1] to [6].

[8] (A) 50 to 150 parts by mass of a mineral oil-based softening material with respect to 100 parts by mass of an ethylene copolymer that satisfies the following conditions (1) and (2): An oil-extended ethylene copolymer, and (B-1-2) α-olefin crystalline thermoplastic resin and α-olefin having a melt tension of less than 3.0 cN at 210 ° C. and a take-off speed of 2.0 m / min. (B-1-1) 210 ° C., take-up speed 2.0 m / min, after dynamically heat-treating the mixture containing at least one of the system amorphous thermoplastic resin in the presence of (C) a crosslinking agent A thermoplastic resin having a melt tension of 3.0 cN or higher and (B-2-1) a thermoplastic resin composition having a melt tension of 210 c ° C. and a take-up speed of 2.0 m / min of 3.0 cN or higher. To add at least one A method for producing a thermoplastic elastomer composition.
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g.
(2): The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3 or less.

  [9] A foam obtained by foaming the thermoplastic elastomer composition according to any one of [1] to [7].

  [10] A method for producing a foam (hereinafter referred to as “first”), which comprises injecting an inert gas into the melted thermoplastic elastomer composition according to any one of [1] to [7], followed by foaming. Also referred to as a method for producing a foam of

  [11] A chemical foaming agent mixed raw material is obtained by blending 0.01 to 20 parts by mass of a chemical foaming agent with respect to 100 parts by mass of the thermoplastic elastomer composition according to any one of [1] to [7]. And a foam production method comprising foaming the obtained chemical foaming agent mixed raw material (hereinafter, also referred to as “second foam production method”).

  The thermoplastic elastomer composition of the present invention is capable of obtaining a foam having a high expansion ratio, a high closed cell property, a uniform foam cell shape, and excellent rubber elasticity, flexibility, and surface appearance. In addition, the fluidity, rubber elasticity, softening material retention, and foaming properties are excellent.

  According to the method for producing a thermoplastic elastomer composition of the present invention, a foam having a high foaming ratio, high closed cell property and uniform foamed cell shape, and excellent rubber elasticity, flexibility and surface appearance is obtained. It is possible to produce a thermoplastic elastomer composition excellent in fluidity, rubber elasticity, softening material retention, and foamability.

  The foam of the present invention has effects such as high foaming ratio, high closed cell property, uniform foamed cell shape, and excellent rubber elasticity, flexibility, softener retention, and surface appearance. is there.

  According to the first and second foam production methods of the present invention, the foaming ratio is high, the closed cell property is high and the foamed cell shape is uniform, and the rubber elasticity, flexibility, softening material retention, and surface A foam excellent in appearance can be produced.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention. Hereinafter, the “foam production method” of the present invention (this embodiment) refers to both the first foam production method and the second foam production method.

1. Thermoplastic elastomer composition:
One embodiment of the thermoplastic elastomer composition of the present invention is (A) an ethylene copolymer that satisfies the following conditions (1) and (2), and 50 to 100 parts by mass of the ethylene copolymer: An oil-extended ethylene copolymer (hereinafter also referred to as “component (A)”) containing 150 parts by mass of a mineral oil-based softener, (B) (B-1) thermoplastic resin, and (B-2) heat A mixture containing at least one of the plastic resin compositions (hereinafter also referred to as “component (B)”) is dynamically mixed in the presence of (C) a crosslinking agent (hereinafter also referred to as “component (C)”). The melt tension (hereinafter also simply referred to as “melt tension”) at 210 ° C. and a take-up speed of 2.0 m / min obtained by heat treatment is 5.0 cN or more, at 70 ° C. for 22 hours in accordance with JIS K6262. Measured compression set (hereinafter simply referred to as “compression set”) Is 80% or less. The details will be described below.
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g.
(2): The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3 or less.

((A) Oil-extended ethylene copolymer)
The component (A) is an ethylene copolymer satisfying the above conditions (1) and (2), and 50 to 150 parts by mass of the first mineral oil system with respect to 100 parts by mass of the ethylene copolymer. An oil-extended ethylene-based copolymer containing a softening material.

  Since the component (A) has a small number of molecular chain terminals having poor deformation recovery properties, the rubber elasticity of the resulting thermoplastic elastomer composition is improved. In addition, since the component (A) has a low content of the ultra-high molecular weight component having a high melt viscosity, the dispersibility with other components (for example, the component (B)) becomes good, and the thermoplastic elastomer composition obtained Mechanical strength is improved. Moreover, since the ethylene-based copolymer contained in the component (A) has a low content of low molecular weight components, the softening material is highly retained, and a large amount of mineral oil-based softening material can be contained. Therefore, the thermoplastic elastomer composition of this embodiment is excellent in moldability.

  The component (A) is preferably obtained by removing the solvent from a mixed solution containing an ethylene copolymer, a mineral oil softening material, and a solvent. The component (A) thus obtained has a lower viscosity than the case of the ethylene copolymer alone, so that dispersibility with other components (for example, the component (B)) is improved. In addition, since the mineral oil-based softening material is uniformly dispersed in the ethylene-based copolymer, there is an advantage that the mineral oil-based softening material is difficult to bleed out.

(Ethylene copolymer)
The ethylene copolymer satisfies the above conditions (1) and (2). By including such an ethylene-based copolymer, the component (A) has an advantage that the number of molecular chain terminals having a poor deformation recovery property is small and the content of the ultrahigh molecular weight component having a high melt viscosity is small. .

  Specific examples of the ethylene copolymer include an ethylene / α-olefin copolymer (binary copolymer), an ethylene / α-olefin / non-conjugated polyene copolymer (ternary copolymer), and the like. Can do.

  The α-olefin for obtaining the ethylene / α-olefin copolymer is preferably an α-olefin having 3 to 20 carbon atoms, more preferably an α-olefin having 3 to 12 carbon atoms, and α having 3 to 8 carbon atoms. -Olefin is particularly preferred. Specific examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 1-decene. Of these, propylene, 1-butene, 1-hexene and 1-octene are preferable, and propylene is particularly preferable from the viewpoint of industrial availability. In addition, these alpha olefins can be used individually by 1 type or in combination of 2 or more types.

  In addition, the content ratio of the structural unit derived from ethylene in the ethylene / α-olefin copolymer is preferably 50 to 80% by mass, and preferably 54 to 75% by mass with respect to the total structural units. Further preferred is 60 to 70% by weight. When the content ratio of the structural unit derived from ethylene is within the above range, there is an advantage that the balance between mechanical strength and flexibility is excellent. In addition, it exists in the tendency for crosslinking efficiency to fall that the content rate of the structural unit derived from ethylene is less than 50 mass% (especially when using an organic peroxide as a crosslinking agent), and sufficient mechanical strength is provided. It becomes difficult to obtain. On the other hand, if it exceeds 80% by mass, flexibility may be lowered.

  As the α-olefin for obtaining the ethylene / α-olefin / non-conjugated polyene copolymer, the same α-olefin as for obtaining the ethylene / α-olefin copolymer can be used. The content ratio of the structural unit derived from ethylene in the ethylene / α-olefin / non-conjugated polyene copolymer is preferably 50 to 80% by mass, and 54 to 75% by mass with respect to the total structural units. It is more preferable that it is 60 to 70% by mass. When the content ratio of the structural unit derived from ethylene is within the above range, there is an advantage that the balance between mechanical strength and flexibility is excellent. In addition, it exists in the tendency for crosslinking efficiency to fall that the content rate of the structural unit derived from ethylene is less than 50 mass% (especially when using an organic peroxide as a crosslinking agent), and sufficient mechanical strength is provided. It becomes difficult to obtain. On the other hand, if it exceeds 80% by mass, flexibility may be lowered.

  Specific examples of non-conjugated polyene for obtaining an ethylene / α-olefin / non-conjugated polyene copolymer include 5-ethylidene-2-norbornene, dicyclopentadiene, 5-propylidene-2-norbornene, and 5-vinyl-2. -Cyclic polyenes such as norbornene, 2,5-norbornadiene, 1,4-cyclohexadiene, 1,4-cyclooctadiene, 1,5-cyclooctadiene; 1,4-hexadiene, 4-methyl-1,4- Hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6- Octadiene, 5,7-dimethyl-1,6-octadiene, 7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 7-methyl-4 -Ethylidene-1,6-nonadiene, 7-ethyl-4-ethylidene-1,6-nonadiene, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1 1,6-nonadiene and the like chain polyene having an internal unsaturated bond having 6 to 15 carbon atoms; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9 Examples include α, ω-dienes such as -decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, 1,13-tetradecadiene, and the like. Of these, 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 7-methyl-1,6-octadiene and 5-methyl-1,4-hexadiene are preferable, and 5-ethylidene-2 is preferable. -Norbornene is particularly preferred. In addition, these nonconjugated polyenes can be used individually by 1 type or in combination of 2 or more types.

  The content ratio of the structural unit derived from the non-conjugated polyene in the ethylene / α-olefin / non-conjugated polyene copolymer is such that the iodine value of the ethylene / α-olefin / non-polyene copolymer is 0 to 40. It is preferable that it is the quantity used as 0-30. This iodine value is a value that serves as a guide for the content of structural units derived from non-conjugated polyenes in the copolymer. If the iodine value is more than 40, gelation tends to occur during kneading. There is a risk that so-called “pops” may occur in a molding process such as extrusion.

  The intrinsic viscosity [η] of the ethylene copolymer measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g, and preferably 5.5 to 8.5 dl / g. More preferably, it is 0.5 to 8.0 dl / g, and particularly preferably 5.5 to 7.5 dl / g. If the intrinsic viscosity [η] is less than 5.5 dl / g, the rubber elasticity is lowered. On the other hand, when it exceeds 9.0 dl / g, the viscosity becomes too high and industrial productivity is lowered. The intrinsic viscosity [η] can be measured using, for example, an Ubbelohde viscometer.

  The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the ethylene-based copolymer is 3 or less, preferably 2.8 or less, 2.0 More preferably, it is -2.7. When the value of Mw / Mn is more than 3, rubber elasticity, softening material retention, and moldability are deteriorated. The “weight average molecular weight (Mw)” is a value in terms of polystyrene measured using gel permeation chromatography.

  The area ratio of the region having a molecular weight of 100,000 or less in terms of polystyrene in the gel permeation chromatography chromatogram of the ethylene copolymer is preferably 3% or less, and more preferably 0 to 3%. The content is preferably 0 to 2.5%. If the area ratio is more than 3%, rubber elasticity and softening material retention may be deteriorated.

Here, the calculation method of "the area ratio of the area | region of the molecular weight 100,000 or less converted into polystyrene in the chromatogram of a gel permeation chromatography" is demonstrated concretely using FIG. FIG. 1 is a schematic diagram showing a chromatogram obtained by analyzing an ethylene copolymer by gel permeation chromatography. First, the integral value of the elution curve 1 of the chromatogram shown in FIG. 1 (the total area surrounded by the elution curve 1 and the horizontal axis (shown as “S _T ” in FIG. 1)) is calculated. Next, an integral value (area (denoted as “S1” in FIG. 1)) of a portion detected after time (elution time) T1 at which a component having a molecular weight of 100,000 converted into polystyrene is eluted is calculated. Next, from these values, the formula: (S1 / S _T ) × 100 is calculated to be “the area ratio of the region having a molecular weight of 100,000 or less converted to polystyrene in the chromatogram of gel permeation chromatography”.

  The ethylene-based copolymer can be produced, for example, by appropriately selecting a method such as a gas phase polymerization method, a solution polymerization method, or a slurry polymerization method. The polymerization operation may be batch or continuous. In the solution polymerization method or slurry polymerization method, an inert hydrocarbon solvent can be used as a reaction medium. Specific examples of the inert hydrocarbon solvent include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-decane and n-dodecane; alicyclic rings such as cyclohexane and methylcyclohexane Aromatic hydrocarbons such as benzene, toluene, xylene and the like. In addition, these inert hydrocarbon solvents can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of the polymerization catalyst used in producing the ethylene-based copolymer include an olefin polymerization catalyst comprising a transition metal compound selected from the group consisting of V, Ti, Zr, and Hf, and an organometallic compound. Etc. The transition metal compound and the organometallic compound may be used either individually or in combination of two or more.

  Specific examples of such olefin polymerization catalysts include metallocene catalysts composed of metallocene compounds and organoaluminum compounds, metallocene catalysts composed of metallocene compounds and ionic compounds that react with metallocene compounds to form ionic complexes, and A Ziegler-Natta catalyst comprising a vanadium compound and an organoaluminum compound can be exemplified. In addition, hydrogen gas can also be used as a molecular weight regulator in the case of manufacture of an ethylene-type copolymer. The amount of hydrogen gas used varies depending on the polymerization conditions such as catalyst type, catalyst amount, polymerization temperature, polymerization pressure, and the polymerization process such as polymerization scale, stirring state, and charging method.For example, a Ziegler-Natta catalyst is used. In the conventional solution polymerization, it is preferably 0.01 to 20 ppm, more preferably 0.1 to 10 ppm, based on all monomer components.

(Mineral oil softener)
The mineral oil-based softening material is used for imparting moldability and flexibility to the obtained thermoplastic elastomer composition and improving the appearance of the product. Specific examples of the mineral oil softener include aromatic, naphthenic, paraffinic and the like. Among these, a paraffinic or naphthenic mineral oil-based softening material that is excellent in retention due to its high compatibility with the ethylene-based copolymer and excellent in weather resistance is preferable.

  The amount of the mineral oil-based softening material used is 50 to 150 parts by mass, preferably 80 to 140 parts by mass, and 90 to 130 parts by mass with respect to 100 parts by mass of the ethylene-based copolymer. Further preferred. When the amount of the mineral oil-based softening material used is less than 50 parts by mass, flexibility and moldability are deteriorated. On the other hand, if it exceeds 150 parts by mass, stickiness occurs and industrial productivity decreases.

The shape of (A) may be any shape such as a bale, crumb, pellet or the like. The component (A) is preferably amorphous or low crystalline from the viewpoint of improving the flexibility and elastic recovery of the resulting thermoplastic elastomer composition. In addition, since the crystallinity is related to the density, it is generally performed to substitute the crystallinity at a density that can be measured more easily than the crystallinity, and the density of the component (A) is 0.89 g / It is preferable that it is cm ³ or less. Furthermore, the crystallinity of the ethylene copolymer as measured by X-ray diffraction is preferably 20% or less, and more preferably 15% or less. If the crystallinity is more than 20%, the flexibility of the ethylene copolymer may be lowered.

  Although the manufacturing method of (A) component does not have a restriction | limiting in particular, For example, it can manufacture by desolvating the liquid mixture containing an ethylene-type copolymer, a mineral oil type softening material, and a solvent. Specifically, a predetermined amount of mineral oil-based softening material is added to the ethylene-based copolymer solution obtained by polymerization, and the kneaded product obtained by kneading with a kneader is subjected to a steam stripping method or a flash method. A method of removing the solvent by a method such as In addition, the ethylene copolymer obtained by polymerization and drying is uniformly used in a good solvent such as a hydrocarbon solvent such as benzene, toluene, xylene, hexane, heptane, cyclohexane, or a halogenated hydrocarbon solvent such as chlorobenzene. A predetermined amount of the first mineral oil-based softening material is added to the solution obtained by dissolving in the solution, and the kneaded product obtained by kneading with a kneader is removed by a method such as a steam stripping method or a flash method. The method of solvent can also be mentioned. As the kneading machine, usual apparatuses used for rubber oil expansion, such as a Banbury mixer, a pressure kneader, and a roll, can be used.

((B) (B-1) thermoplastic resin and / or (B-2) thermoplastic resin composition)
The component (B) includes (B-1) a thermoplastic resin (hereinafter also referred to as “(B-1) component”) and (B-2) a thermoplastic resin composition (hereinafter referred to as “(B-2) component”). Or at least one of them).

((B-1) Thermoplastic resin)
Specific examples of the component (B-1) include aminoacrylamide polymer, polyolefin-based crystalline resin and its maleic anhydride graft polymer, polyolefin-based amorphous resin and its maleic anhydride graft polymer, polyisobutylene, ethylene Vinyl chloride polymer, ethylene vinyl alcohol polymer and its ionomer, ethylene vinyl acetate copolymer, polyethylene oxide, ethylene acrylic acid copolymer, polyisobutylene and its maleic anhydride graft polymer, chlorinated polypropylene, 4-methylpentene -1 resin, polystyrene, ABS resin, ACS resin, AS resin, AES resin, ASA resin, MBS resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinylidene chloride resin, polyamide resin, polycarbonate, acrylic resin, Methacrylic resins, vinyl chloride resins, vinylidene chloride resins, vinyl alcohol resins, vinyl acetal resins, methyl methacrylate resins, fluororesins, polyether resins, polyethylene terephthalate, polyacrylates, polyamide resins, and the like. Of these, polyolefin crystalline resins and polyolefin amorphous resins are preferred.

  The polyolefin-based crystalline resin is not particularly limited, but an α-olefin-based crystalline resin mainly containing an α-olefin is preferably used. That is, it is preferable that the α-olefin is contained in an amount of 80 mol% or more (more preferably 90 mol% or more) when the entire olefinic crystalline resin is 100 mol%. The polyolefin-based crystalline resin may be a homopolymer of an α-olefin, a copolymer of two or more α-olefins, or a copolymer with a monomer that is not an α-olefin. May be. Moreover, the mixture of these 2 or more types of different polymers and / or copolymers may be sufficient.

  As the α-olefin constituting the polyolefin-based crystalline resin, it is preferable to use an α-olefin having 2 or more carbon atoms, and it is more preferable to use an α-olefin having 2 to 12 carbon atoms.

  As the α-olefin, ethylene, propene (hereinafter referred to as “propylene”), 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl- C2-C12 alpha olefins, such as 1-pentene, 3-ethyl- 1-pentene, 1-octene, 1-decene, 1-undecene, can be mentioned. These α-olefins can be used singly or in combination of two or more.

  When the polyolefin-based crystalline resin is a copolymer, the copolymer may be a random copolymer or a block copolymer. However, in order to have crystallinity, in the random copolymer, the total content of the structural units excluding the α-olefin is 15 mol% or less (more preferably, when the entire random copolymer is 100 mol%). 10 mol% or less) is preferable. In the block copolymer, the total content of the structural units excluding the α-olefin is 40 mol% or less (more preferably 20 mol% or less) when the entire block copolymer is 100 mol%. It is preferable.

  On the other hand, the polyolefin-based amorphous resin is not particularly limited, but an α-olefin-based amorphous resin mainly containing an α-olefin is preferably used. That is, when the total amount of the polyolefin-based amorphous resin is 100 mol%, the α-olefin is preferably contained in an amount of 50 mol% or more (more preferably 60 mol% or more). The polyolefin-based amorphous resin may be a homopolymer of an α-olefin, a copolymer of two or more α-olefins, or a copolymer with a monomer that is not an α-olefin. There may be. Moreover, the mixture of these 2 or more types of different polymers and / or copolymers may be sufficient.

  As the α-olefin constituting the polyolefin-based amorphous resin, it is preferable to use an α-olefin having 3 or more carbon atoms, and the same α-olefin having 3 to 12 carbon atoms as exemplified in the polyolefin-based crystalline resin. More preferably, is used.

  Examples of the polyolefin-based amorphous resin include homopolymers such as atactic polypropylene and atactic poly-1-butene, propylene (containing 50 mol% or more) and other α-olefins (ethylene, 1-butene, 1-butene). Copolymer with pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc., 1-butene (containing 50 mol% or more) and other α-olefin (ethylene, propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and the like).

  When the polyolefin-based amorphous resin is a copolymer, this copolymer may be either a random copolymer or a block copolymer. However, in the case of a block copolymer, the α-olefin units which are the main components (propylene and 1-butene in the case of the copolymer) need to be bonded with an atactic structure. In addition, when the polyolefin-based amorphous resin is a copolymer of an α-olefin having 3 or more carbon atoms and ethylene, assuming that the entire copolymer is 100 mol%, the content ratio of the α-olefin is 50 It is preferable that it is more than mol% (more preferably 60-100 mol%).

  The component (B-1) is a thermoplastic resin having a melt tension of 3.0 cN or higher at 210 ° C. and a take-off speed of 2.0 m / min (hereinafter also referred to as “component (B-1-1)”). preferable. Further, the melt tension of the component (B-1-1) is more preferably 5.0 cN or more, and particularly preferably 8.0 cN or more. When the melt tension of the component (B-1-1) is less than 3.0 cN, the melt tension of the thermoplastic elastomer composition containing the component (B-1-1) may be less than 5.0 cN. . When this thermoplastic elastomer composition is foamed, the expansion ratio is low, independent bubbles are hardly formed, and the shape of the formed bubbles is difficult to be uniform. Therefore, by containing the component (B-1-1) whose melt tension is equal to or higher than a predetermined numerical value, it is possible to obtain a foam having a high foaming ratio, high closed cell property, and uniform foamed cell shape. It becomes possible.

  Moreover, the compression set of the component (B-1) is preferably 60% or less, and more preferably 50% or less. When the compression set of the component (B-1) exceeds 60%, the flexibility and rubber elasticity of the thermoplastic elastomer composition containing the component (B-1) tend to decrease. Therefore, it becomes possible to obtain a foam excellent in rubber elasticity and flexibility by including the component (B-1) whose compression set is a predetermined numerical value or more.

((B-2) Thermoplastic resin composition)
The thermoplastic resin contained in the component (B-2) is at least an α-olefin crystalline thermoplastic resin and an α-olefin amorphous thermoplastic resin similar to those exemplified in the component (B-1). Either can be mentioned as a suitable example. Moreover, it is preferable that (B-2) component contains these thermoplastic resins and a hydrogenated diene polymer.

  The hydrogenated diene polymer that may be contained in the component (B-2) is not particularly limited as long as it is a hydrogenated diene copolymer containing a structural unit derived from a conjugated diene compound. Accordingly, specific examples of the hydrogenated diene polymer include (I) a hydrogenated product of a polymer containing only a structural unit derived from a conjugated diene compound, (II) a structural unit derived from a conjugated diene compound, and this conjugate. Examples thereof include a hydrogenated product such as a copolymer containing a structural unit derived from a compound that can be polymerized with a diene compound (for example, a vinyl aromatic compound).

(Hydrogenated diene polymer)
The thermoplastic elastomer composition of the present invention preferably contains a hydrogenated diene polymer. As the hydrogenated diene polymer, any hydrogenated conjugated diene polymer may be used. A hydrogenated random copolymer of a conjugated diene and a single aromatic vinyl compound, and the following (i) A hydrogenated block copolymer containing two or more polymer blocks selected from the group consisting of polymer blocks (v) is preferable.

(I) Aromatic vinyl compound polymer block in which aromatic vinyl compound is 80% by mass or more (ii) Conjugated diene polymer block in which conjugated diene is 80% by mass or more (iii) 1,2- and 3,4- Conjugated diene polymer block having a total bond content of less than 25% by mass (iv) Conjugated diene polymer block having a total of 1,2- and 3,4-bond content of 25 to 90% by mass (v) Aromatic vinyl compound Random copolymer block of conjugated dienes

  The random copolymer block (v) may include a so-called tapered type in which the aromatic vinyl compound content continuously changes in one molecule. Examples of the block structure of the “block copolymer containing two or more polymer blocks selected from the group consisting of polymer blocks (i) to (v)” include those shown below. be able to.

(I)-(ii), (i)-(iii), (i)-(iv), (i)-(v), (iii)-(iv), (iii)-(v), [( i)-(ii)] _x- Y, [(i)-(iii)] _x- Y, [(i)-(iv)] _x- Y, [(i)-(v)] _x- Y, [(Iii)-(iv)] _x- Y, [(iii)-(v)] _x- Y, (i)-(ii)-(iii), (i)-(ii)-(v), (I)-(ii)-(i), (i)-(iii)-(i), (i)-(iv)-(i), (i)-(iv)-(iii), (iii) )-(Iv)-(iii), (i)-(v)-(i), [(i)-(ii)-(iii)] _x- Y, [(i)-(ii)-(v )] _X- Y, [(i)-(ii)-(i)] _x- Y, [(i)-(iii)-(i)] _x- Y, [(i)-(iv)-(i)] _x- Y, [(i)-(iv)-(iii)] _x- Y, [(i)-(v)-(i) ] _X- Y, (i)-(ii)-(i)-(ii), (ii)-(i)-(ii)-(i), (i)-(iii)-(i)-( iii), (iii)-(i)-(iii)-(i), [(i)-(ii)-(ii)-(ii)] _x -Y, (i)-(ii)-(i )-(Ii)-(i), [(i)-(ii)-(i)-(ii)-(i)] _x -Y, [(ii)-(i)] _x -Y, [( iii)-(i)] _x- Y, [(iv)-(i)] _x- Y, [(v)-(i)] _x- Y, (ii)-(i)-(ii)-( iii), (ii)-(i)-(ii)-(v), (ii)-(i)-(ii)-(i), (ii)-(i )-(Iii)-(i), (iii)-(i)-(iv)-(i), (iii)-(i)-(iv)-(iii), (iii)-(i)- (V)-(i), [(iii)-(i)-(ii)-(iii)] _x- Y, [(iv)-(i)-(ii)-(v)] _x- Y, [(Iv)-(i)-(ii)-(i)] _x- Y, [(iv)-(i)-(iii)-(i)] _x- Y, [(iv)-(i) -(Iv)-(i)] _x- Y, [(iv)-(i)-(iv)-(iii)] _x- Y, [(iv)-(i)-(v)-(i) ] _X- Y, (iv)-(i)-(ii)-(i)-(ii), (iv)-(ii)-(i)-(ii)-(i), (iv)-( i)-(iii)-(i)-(iii), (iv)-(iii)-(i)-(iii)- i), [(iv) - (i) - (ii) - (i) - (ii)] x -Y, (iv) - (i) - (ii) - (i) - (i) - (i ), [(Iv)-(i)-(ii)-(i)-(ii)-(i)] _x -Y

  However, in the above block structure, x ≧ 2, and Y is a residue of the coupling agent. In addition, when making a block copolymer into a pellet shape, it is preferable that at least any one of the polymer block of (i) and the polymer block of (iii) is contained as an outer block component.

  In the case where the block copolymer is a modified block copolymer containing a residue of a coupling agent, examples of the coupling agent include halogen compounds, epoxy compounds, carbonyl compounds, and polyvinyl compounds. More specifically, for example, methyldichlorosilane, methyltrichlorosilane, butyltrichlorosilane, tetrachlorosilane, dibromoethane, epoxidized soybean oil, divinylbenzene, tetrachlorotin, butyltrichlorotin, tetrachlorogermanium, bis (trichlorosilyl) ) Ethane, diethyl adipate, dimethyl adipate, dimethyl terephthalic acid, diethyl terephthalic acid, polyisocyanate and the like.

  The microstructure of the hydrogenated diene polymer, ie the content of 1,2- and 3,4-bonds, can be controlled by using a Lewis base together with a hydrocarbon solvent. Examples of such a Lewis base include ethers and amines. More specifically, (1) diethyl ether, tetrahydrofuran, propyl ether, butyl ether, higher ether, tetrahydrofurfuryl methyl ether, tetrahydrofurfuryl ethyl ether, 1,4-dioxane, bis (tetrahydrofurfuryl) formal, 2, 2-bis (2-tetrahydrofurfuryl) propane, and polyalkylene glycol ether derivatives such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene glycol ethyl propyl ether, and (2) tetramethylethylenediamine, Examples thereof include tertiary amines such as pyridine and tributylamine.

  When the hydrogenated diene polymer is a hydrogenated modified diene polymer, the modified conjugated diene polymer that is a pre-hydrogenated polymer of the hydrogenated modified diene polymer is converted into a conjugated diene polymer. It can be obtained by reacting an alkoxysilane compound. Preferably, a modified conjugated diene polymer can be obtained by reacting an alkoxysilane compound with the active terminal of the conjugated diene polymer and bonding a polar group to the polymer terminal. By this method, it is possible to obtain a hydrogenated modified diene polymer that is excellent in affinity with polar resins and fillers, and excellent in heat resistance, impact resistance, strength, and adhesion as compared with conventional methods. There is no particular limitation on the amount of the alkoxysilane compound to be reacted, and an appropriate amount can be added as necessary. Usually, it is 10 mol% or more, preferably 20 mol%, based on the conjugated diene polymer. As mentioned above, More preferably, it is 30 mol% or more. Although depending on the molecular weight of the modifier, it is 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.02% by mass or more based on the conjugated diene polymer. By setting it as this range, since affinity with polar resin and a filler can fully be provided with respect to the hydrogenation modification diene type polymer finally obtained, it is preferable.

The “alkoxysilane compound” used in the production of the hydrogenated modified diene polymer is not limited in its structure as long as it can be modified by reacting with the conjugated diene polymer, but usually, An alkoxysilane compound represented by the following general formula (1) is used.
R ¹ _(4-mn) Si (OR ² ) _m X _n (1)

In the general formula (1), R ¹ represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an organosiloxy group, and there are a plurality of R ^1. In some cases, each R ¹ may be the same or different group. R ² represents an alkyl group, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms having 1 to 20 carbon atoms, ^{when R 2} are plural, each of ^{R 2} different even in the same group It may be a group. X represents a substituent having a polar group containing at least one of an N atom, an O atom, and an Si atom. When there are a plurality of X, each X may be the same group or different groups, and each X may be an independent substituent or may form a cyclic structure. m is 1, 2, or 3, and n is 0, 1, 2, or 3. The sum of m and n is 1 to 4.

  Specific examples of the alkoxysilane compound represented by the general formula (1) include tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, methylpropoxysilane, and ethyltrimethoxysilane. , Ethyltriethoxysilane, ethyltributoxysilane, ethyltripentyloxysilane, ethyltrineopentyloxysilane, ethyltrihexyloxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltributoxysilane, dimethyldimethoxysilane, dimethyl Diethoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldibutoxysilane, diphenyldimethoxysilane, diphenyldie Aliphatic hydrocarbon alkoxysilane compounds such as xyloxysilane and diphenyldibutoxysilane; methyltriphenoxysilane, ethyltriphenoxysilane, phenyltriphenoxysilane, dimethyldiphenoxysilane, diethyldiphenoxysilane, and diphenyldiphenoxysilane An aromatic hydrocarbon type alkoxysilane compound etc. can be mentioned.

  Specific examples of the alkoxysilane compound represented by the general formula (1) containing an N atom in X which is a polar group include N, N-di (trimethylsilyl) aminopropyltrimethoxysilane, N, N-di (Trimethylsilyl) aminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminopropyldimethylethoxysilane, N, N-bis (trimethylsilyl) aminopropyldimethylmethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxy Silane, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-di (trimethylsilyl) aminoethyltrimethoxysilane, N, N-di (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis ( Trimethylsilyl) Noethyldimethylethoxysilane, N, N-bis (trimethylsilyl) aminoethyldimethylmethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane, 1 -When a protective group is removed by hydrolysis of trimethylsilyl-2-dimethoxy-1-aza-2-silacyclopentane, 1-trimethylsilyl-2-diethoxy-1-aza-2-silacyclopentane, etc., a primary amine is obtained. Compound: N-methyl-N-trimethylsilylaminopropyltrimethoxysilane, N-methyl-N-trimethylsilylaminopropyltriethoxysilane, N-methyl-N-trimethylsilylaminopropyldimethylethoxysilane, N-methyl-N-trimethyl Silylaminopropyldimethylmethoxysilane, N-methyl-N-trimethylsilylaminopropylmethyldiethoxysilane, N-methyl-N-trimethylsilylaminopropylmethyldimethoxysilane, N-methyl-N-trimethylsilylaminoethyltrimethoxysilane, N-methyl -N-trimethylsilylaminoethyltriethoxysilane, N-methyl-N-trimethylsilylaminoethyldimethylethoxysilane, N-methyl-N-trimethylsilylaminoethyldimethylmethoxysilane, N-methyl-N-trimethylsilylaminoethylmethyldiethoxysilane, N-methyl-N-trimethylsilylaminoethylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropy Secondary amines such as triethoxysilane, dimethoxymethyl-3-piperazinopropylsilane, and 3-piperazinopropyltrimethoxysilane, or compounds that become secondary amines when protected by hydrolysis; N, N- Dimethylaminopropyltrimethoxysilane, N, N-dimethylaminopropyltriethoxysilane, N, N-dimethylaminopropyldimethylethoxysilane, N, N-dimethylaminopropyldimethylmethoxysilane, N, N-dimethylaminopropylmethyldiethoxy Silane, N, N-dimethylaminopropylmethyldimethoxysilane, N, N-dimethylaminoethyltrimethoxysilane, N, N-dimethylaminoethyltriethoxysilane, N, N-bismethylaminoethyldimethylethoxysilane, N, N -Bismethyl Aminoethyldimethylmethoxysilane, N, N-bismethylaminoethylmethyldiethoxysilane, N, N-bismethylaminoethylmethyldimethoxysilane, dimethoxymethyl-2-piperidinoethylsilane, and 2-piperidinoethyltri There may be mentioned tertiary amines such as methoxysilane.

  Examples of the alkoxysilane compound represented by the general formula (1) containing an O atom in X which is a polar group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ -Methacryloxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyl Dimethoxysilane, β- 3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethylphenoxyethoxysilane, γ-glycidoxy Examples thereof include propyldiethoxyphenoxysilane and γ-methacryloxypropylmethyldiphenoxysilane.

  Furthermore, examples of the alkoxysilane compound represented by the general formula (1) containing a Si atom in X which is a polar group include trimethylsiloxytriphenoxysilane, trimethylsiloxytrimethoxysilane, trimethylsiloxytriethoxysilane, and trimethylsiloxy. Examples thereof include tributoxysilane, 1,1,3,3-tetramethyl-1-phenoxydisiloxane, and the like.

  Among these, an aromatic hydrocarbon-based alkoxysilane compound and an alkoxysilane compound containing X having a polar group are preferable from the viewpoints of modification reaction, hydrogenation reaction, and improvement of physical properties, and further, X having a polar group. An alkoxysilane compound containing is preferable. Among alkoxysilane compounds containing X having a polar group, those containing an N atom are preferred from the viewpoint of improving physical properties, and in particular, a primary or secondary amine is obtained by removing protection of a trimethylsilyl group or the like. Those having a protected primary or secondary amino group are preferred, and those having a protected primary amino group are particularly preferred.

  The hydrogenated diene polymer can be obtained by partially or selectively hydrogenating a conjugated diene polymer. The hydrogenation method and reaction conditions are not particularly limited. Usually, the hydrogenation is carried out at 20 to 150 ° C. under hydrogen pressure of 0.1 to 10 MPa in the presence of a hydrogenation catalyst. The hydrogenation rate can be arbitrarily selected by changing the amount of the hydrogenation catalyst, the hydrogen pressure during the hydrogenation reaction, or the reaction time. The hydrogenation rate is usually 10% or more of the aliphatic double bond based on the conjugated diene which is an unsaturated part, preferably 50% or more, more preferably 80% or more, particularly in order to improve heat resistance and weather resistance. Preferably it is 95% or more.

  The hydrogenation catalyst that can be used is a compound containing any one of Group Ib, IVb, Vb, VIb, VIIb, and Group VIII metals, for example, Ti, V, Co, Ni, Zr, Ru, Rh, Pd. , Hf, Re, and a compound containing Pt atoms. More specific hydrogenation catalysts include, for example, metallocene compounds such as Ti, Zr, Hf, Co, Ni, Pd, Pt, Ru, Rh, and Re, and metals such as Pd, Ni, Pt, Rh, and Ru. Homogeneous Ziegler type that combines a supported heterogeneous catalyst supported on a carrier such as carbon, silica, alumina, or diatomaceous earth, an organic salt of a metal element such as Ni or Co, or an acetylacetone salt and a reducing agent such as organoaluminum. Examples of the catalyst include organometallic compounds such as Ru and Rh. In addition, these hydrogenation catalysts can be used individually by 1 type or in combination of 2 or more types. Among these, a metallocene compound containing Ti, Zr, Hf, Co, or Ni is preferable in that it can be hydrogenated in a homogeneous system in an inert organic solvent, and a metallocene compound containing Ti, Zr, or Hf is more preferable. In particular, a hydrogenation catalyst obtained by reacting a titanocene compound with an alkyl lithium is preferable because it is inexpensive and particularly useful industrially. Specific examples include, for example, JP-A-1-275605, JP-A-5-271326, JP-A-5-271325, JP-A-5-222115, JP-A-11-292924, and JP-A-11-292924. JP 2000-37632 A, JP 59-133203 A, JP 63-5401 A, JP 62-218403 A, JP 7-90017 A, JP 43-19960 A, Mention may be made of the hydrogenation catalyst described in JP-B 47-40473.

  After hydrogenation, the catalyst residue is removed as necessary, or a phenolic or amine-based antiaging agent is added, and then the hydrogenated diene polymer is isolated from the hydrogenated diene polymer solution. Isolation of the hydrogenated diene polymer may be carried out, for example, by adding acetone or alcohol to the hydrogenated diene polymer solution and precipitating the solution, adding the hydrogenated diene polymer solution into hot water with stirring, and removing the solvent. It can be carried out by a method such as distillation removal. By the above procedure, a hydrogenated diene polymer excellent in modification of heat resistance, impact resistance, strength, and adhesive moldability can be obtained.

  In addition, as a hydrogenated diene polymer, the following commercial items can be used. For example, Kuraray brand name “Septon”, brand name “Hibler”, Asahi Kasei brand name “Tough Tech”, JSR brand name “Dynalon”, etc. Or the like.

  The mass ratio of the thermoplastic resin and the hydrogenated diene polymer contained in the component (B-2) is preferably thermoplastic resin / hydrogenated diene polymer = 99/1 to 20/80, The thermoplastic resin / hydrogenated diene polymer is more preferably 98/2 to 30/70, and the thermoplastic resin / hydrogenated diene polymer is particularly preferably 97/3 to 40/60. When the content of the thermoplastic resin is less than 20% by mass and the content of the hydrogenated diene polymer is more than 80% by mass, the molding processability of the obtained component (B-2) tends to deteriorate. On the other hand, when the content of the thermoplastic resin exceeds 99% by mass and the content of the hydrogenated diene polymer is less than 1% by mass, the flexibility and rubber elasticity of the component (B-2) obtained tend to decrease. The compression set tends to be over 60%.

  Component (B-2) is a thermoplastic resin composition (hereinafter also referred to as “component (B-2-1)”) having a melt tension of 3.0 cN or higher at 210 ° C. and a take-off speed of 2.0 m / min. It is preferable. Further, the melt tension of the component (B-2-1) is more preferably 5.0 cN or more, and particularly preferably 8.0 cN or more. When the melt tension of the component (B-2-1) is less than 3.0 cN, the melt tension of the thermoplastic elastomer composition containing the component (B-2-1) may be less than 5.0 cN. . When this thermoplastic elastomer composition is foamed, the expansion ratio is low, independent bubbles are hardly formed, and the shape of the formed bubbles is difficult to be uniform. Therefore, by including the component (B-2-1) whose melt tension is equal to or higher than a predetermined numerical value, it is possible to obtain a foam having a high foaming ratio, a high closed cell property, and a uniform foam cell shape. It becomes.

  Further, the compression set of the component (B-2) is preferably 60% or less, and more preferably 50% or less. When the compression set of the component (B-2) exceeds 60%, the flexibility and rubber elasticity of the thermoplastic elastomer composition containing the component (B-2) tend to decrease. On the other hand, when the compression set is more than 80%, when foamed, the resulting foam tends to be inferior in rubber elasticity and flexibility. Therefore, it becomes possible to obtain a foam excellent in rubber elasticity and flexibility by including the component (B-2) whose compression set is a predetermined numerical value or more.

  In addition, (B-1) component and (B-2) component can each be used individually by 1 type or in combination of 2 or more types for the thermoplastic elastomer composition of this embodiment.

(Ratio of (A) component and (B) component)
The mass ratio of the component (A) and the component (B) contained in the thermoplastic elastomer composition of the present invention is preferably (A) / (B) = 95/5 to 20/80, (A ) / (B) = 90/10 to 20/80, more preferably (A) / (B) = 90/10 to 30/70. When the component (A) is less than 20% by mass and the component (B) is more than 80% by mass, the flexibility and rubber elasticity of the resulting thermoplastic elastomer composition tend to be lowered. Therefore, it is possible to obtain a foam excellent in rubber elasticity and flexibility by using a thermoplastic elastomer composition having (A) component of 20% by mass or more and (B) component of 80% by mass or less. . On the other hand, when the component (A) is more than 95% by mass and the component (B) is less than 5% by mass, the phase structure (morphology) of the resulting thermoplastic elastomer composition is that of the dynamically crosslinked thermoplastic elastomer composition. Good sea-island structure (thermoplastic resin is the sea (matrix) and crosslinked rubber particles are islands (domains)) is difficult to form, and the fluidity and moldability tend to be reduced.

(Thermoplastic elastomer composition)
In the thermoplastic elastomer composition of the present invention, a mixture containing the component (A) and the component (B) is dynamically heat-treated in the presence of (C) a crosslinking agent (hereinafter also referred to as “component (C)”). It will be. Here, “dynamically heat-treating” refers to both applying a shearing force and heating. The thermoplastic elastomer composition of the present invention obtained by such a dynamic heat treatment specifically has the component (B) as the sea phase, and the particles of the component (A) are islands in the sea phase. It constitutes a so-called sea-island structure dispersed as a phase.

  On the other hand, the thermoplastic elastomer composition of the present invention comprises (A) component, (B-1-2) α-olefin crystal having a melt tension of less than 3.0 cN at 210 ° C. and a take-off speed of 2.0 m / min. A mixture containing a thermoplastic thermoplastic resin and / or an α-olefin-based amorphous thermoplastic resin (hereinafter also referred to as “component (B-1-2)”) is dynamically added in the presence of component (C). It is also preferable that the component (B-1-1) and / or the component (B-2-1) is added after the heat treatment. That is, the thermoplastic elastomer composition obtained by such dynamic heat treatment specifically has the component (B-1-2) as the sea phase, and the particles of the component (A) are contained in the sea phase. A sea-island structure dispersed as an island phase is formed, and the component (B-1-1) and / or the component (B-2-1) added later is further contained.

((C) Crosslinking agent)
The thermoplastic elastomer composition of the present invention is subjected to dynamic heat treatment. The kind of (C) component used in the dynamic heat treatment is not particularly limited. However, at least by a dynamic heat treatment at a temperature equal to or higher than the melting point of at least one of the component (B-1-1) and the component (B-2-1), or at a temperature equal to or higher than the melting point of the component (B-1-2). It is preferable that it is a compound which can bridge | crosslink (A) component.

  Specific examples of the component (C) include organic peroxides, phenol resins, sulfur, sulfur compounds, p-quinones, p-quinone dioxime derivatives, bismaleimide compounds, epoxy compounds, silane compounds, amino resins, polyols, A polyamine, a triazine compound, a metal soap, etc. can be mentioned. Of these, organic peroxides and phenol resins are preferable. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the organic peroxide include 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, 2,5-dimethyl- 2,5-bis (t-butylperoxy) hexene-3,2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2,2'-bis (t-butylperoxy)- p-isopropylbenzene, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxide, p-menthane peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl Cyclohexane, dilauroyl peroxide, diacetyl peroxide, t-butyl peroxybenzoate, 2,4-dichlorobenzoyl peroxide, p-chlorobenzoyl Okishido, benzoyl peroxide, may be mentioned di (t-butylperoxy) perbenzoate, n- butyl-4,4-bis (t-butylperoxy) valerate, and t-butyl peroxy isopropyl carbonate. Among them, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 2,5-dimethyl-2,5- Di (t-butylperoxy) hexane, α, α-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, and di-t-butyl peroxide are preferred. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the phenol resin include a p-substituted phenol compound represented by the following general formula (2), an o-substituted phenol / aldehyde condensate, an m-substituted phenol / aldehyde condensate, a brominated alkylphenol / aldehyde condensate, and the like. Can be mentioned. Of these, p-substituted phenolic compounds are preferred. These can be used individually by 1 type or in combination of 2 or more types.

  In said general formula (2), X shows a hydroxyl group, a halogenated alkyl group, or a halogen atom, R shows a C1-C15 saturated hydrocarbon group, n shows the integer of 0-10. The p-substituted phenol compound can be obtained by a condensation reaction between a p-substituted phenol and an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst.

  Commercially available phenolic resins include trade name “Tacicol 201” (alkylphenol formaldehyde resin, manufactured by Taoka Chemical Co., Ltd.), product name “Tacicol 250-I” (brominated alkylphenol formaldehyde resin having a bromination rate of 4%, Taoka Chemical Industries). ), Trade name “Tactrol 250-III” (brominated alkylphenol formaldehyde resin, manufactured by Taoka Chemical Co., Ltd.), trade name “PR-4507” (manufactured by Gunei Chemical Co., Ltd.), trade name “ST137X” (ROHM & Product name “Sumilite Resin PR-22193” (manufactured by Sumitomo Durez), product name “Tamanol 531” (manufactured by Arakawa Chemical Industries), product name “SP1059”, product name “SP1045”, product name “SP1055”, trade name “SP1056” (above, manufactured by Schenectady), It can be cited name "CRM-0803" (manufactured by Showa Union Gosei Co.). Among these, “Tack roll 201” is preferably used.

  (C) The usage-amount of a component shall be 0.01-20 mass parts with respect to a total of 100 mass parts of (A) component and (B) component contained in the mixture for manufacturing a thermoplastic elastomer composition. It is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass.

  (C) When using an organic peroxide as a component, the usage-amount of this organic peroxide is 0.05-10 mass parts with respect to a total of 100 mass parts of (A) component and (B) component. It is preferable to be 0.1 to 5 parts by mass. When the amount of the organic peroxide used exceeds 10 parts by mass, the degree of crosslinking becomes excessively high, the moldability is lowered, and the mechanical properties of the resulting thermoplastic elastomer composition tend to be lowered. On the other hand, when the amount of the organic peroxide used is less than 0.05 parts by mass, the degree of cross-linking is insufficient and the rubber elasticity and mechanical strength of the resulting thermoplastic elastomer composition tend to be lowered.

  Moreover, when using a phenol resin as (C) component, the usage-amount of this phenol resin shall be 0.2-10 mass parts with respect to a total of 100 mass parts of (A) component and (B) component. It is preferably 0.5 to 5 parts by mass. If the amount of the phenol resin used exceeds 10 parts by mass, the moldability tends to decrease. On the other hand, when the amount of the phenol resin used is less than 0.2, the degree of crosslinking is insufficient, and the rubber elasticity and mechanical strength of the resulting thermoplastic elastomer composition tend to be lowered.

  It is preferable to use at least one of a crosslinking aid and a crosslinking accelerator together with the component (C) because the crosslinking reaction can be performed gently and uniform crosslinking can be formed. When an organic peroxide is used as the component (C), sulfur, sulfur compounds (powder sulfur, colloidal sulfur, precipitated sulfur, insoluble sulfur, surface-treated sulfur, dipentamethylene thiuram tetrasulfide, etc.) Oxime compounds (p-quinone oxime, p, p′-dibenzoylquinone oxime, etc.), polyfunctional monomers (ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate), Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, diallyl phthalate, tetraallyloxyethane, triallyl cyanurate, N, N′-m-phenylenebismaleimide N, N'-toluylene bismaleimide, maleic anhydride, divinylbenzene, the use of di (meth) zinc acrylate and the like) or the like. Of these, p, p'-dibenzoylquinone oxime, N, N'-m-phenylenebismaleimide, and divinylbenzene are preferable. These can be used individually by 1 type or in combination of 2 or more types. Note that N, N′-m-phenylenebismaleimide exhibits an action as a crosslinking agent, and therefore can be used alone as a crosslinking agent.

  When the organic peroxide is used as the component (C), the amount of the crosslinking aid used is preferably 10 parts by mass or less with respect to 100 parts by mass in total of the component (A) and the component (B). More preferably, it is 0.2-5 mass parts. When the amount of the crosslinking aid used is more than 10 parts by mass, the degree of crosslinking becomes excessively high, the molding processability is lowered, and the mechanical properties of the resulting thermoplastic elastomer composition tend to be lowered.

  When phenolic resin is used as component (C), metal halides (such as stannous chloride and ferric chloride) and organic halides (such as chlorinated polypropylene, butyl bromide rubber, and chloroprene rubber) are used as crosslinking accelerators. Is preferably used because the crosslinking rate can be adjusted. In addition to the crosslinking accelerator, it is more desirable to use a metal oxide such as zinc oxide or a dispersant such as stearic acid.

(Other softening materials)
It is preferable that the thermoplastic elastomer composition of the present invention further contains a softening material other than the above-described mineral oil-based softening material. By containing a softening material, workability and flexibility can be improved. As a softening material, the softening material generally used for rubber products can be used suitably.

  Specific examples of the softening material include petroleum oils such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and petroleum jelly; coal tars such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil, Fatty oils such as soybean oil and coconut oil; waxes such as tall oil, beeswax, carnauba wax and lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate or metal salts thereof; petroleum resins; Synthetic polymer materials such as coumarone indene resin and atactic polypropylene; ester compounds such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate; microcrystalline wax, sub (factis), liquid polybutadiene, modified liquid polybutadiene, liquid thiocol, liquid It may be mentioned polyisoprene, liquid polybutene, liquid ethylene · alpha-olefin copolymer and the like. Of these, paraffinic, naphthenic, aromatic mineral oil, liquid polyisoprene, liquid polybutene, and liquid ethylene / α-olefin copolymer are preferable, paraffinic mineral oil, liquid polyisoprene, liquid polybutene, liquid ethylene An α-olefin copolymer is more preferable.

  The content of the softening material is preferably 0 to 200 parts by mass, more preferably 0 to 150 parts by mass, and 0 to 100 parts by mass with respect to 100 parts by mass of the component (A). Particularly preferred. When the content of the softening material is more than 200 parts by mass with respect to 100 parts by mass of the component (A), poor dispersion may occur during kneading with the component (B).

(Nucleating agent)
The thermoplastic elastomer composition of the present invention may further contain a nucleating agent. Examples of the nucleating agent that can be contained include calcium carbonate, talc, mica, silica, titania, zinc oxide, zeolite, magnesium carbonate, barium sulfate, aluminum hydroxide, magnesium hydroxide, carbon black, and carbon nanotube. Mention may be made of powders of inorganic compounds. By containing these nucleating agents, the cell diameter can be easily adjusted, and a foam having appropriate flexibility and the like can be obtained. The particle size of the nucleating agent is not particularly limited, but is preferably 0.1 to 50 μm, and more preferably 0.3 to 50 μm. When the particle size of the nucleating agent is less than 0.1 μm, it is difficult to obtain the effect as the nucleating agent, and the cell diameter tends to increase. On the other hand, when the particle size of the nucleating agent is more than 50 μm, the number of cells becomes coarse and the number becomes small, the foam becomes too flexible, and the cushioning property tends to be inferior. The average particle size of the nucleating agent can be measured by a laser diffraction particle size distribution measuring method. On the other hand, the function can be imparted to the foam by selecting the type of the nucleating agent. For example, flame retardancy can be imparted to the foam by making the nucleating agent a metal hydrate, and conductivity can be imparted by making it a carbon material.

  The content of the nucleating agent is preferably 0 to 200 parts by mass, and 0.01 to 150 parts by mass when the total amount of the polymer components contained in the thermoplastic elastomer composition is 100 parts by mass. It is further more preferable and it is especially preferable that it is 0.1-100 mass parts. In addition, it is also preferable to add a nucleating agent to a molding machine as a masterbatch using polypropylene resin etc., for example.

(Additive)
The thermoplastic elastomer composition of the present invention can contain various additives as required. Examples of additives that can be included include lubricants, anti-aging agents, heat stabilizers, light stabilizers such as HALS, weathering agents, metal deactivators, ultraviolet absorbers, light stabilizers, copper damage inhibitors, and the like. Stabilizer, antibacterial agent, antifungal agent, dispersant, flame retardant, tackifier, colorant such as titanium oxide, carbon black and organic pigment, metal powder such as ferrite, inorganic fiber such as glass fiber and metal fiber, Carbon fiber, organic fiber such as aramid fiber, composite fiber, inorganic whisker such as potassium titanate whisker, glass beads, glass balloon, glass flake, asbestos, mica, calcium carbonate, talc, silica, calcium silicate, hydrotalcite, Fillers such as kaolin, diatomaceous earth, graphite, pumice, evo powder, cotton floc, cork powder, barium sulfate, wood powder, etc., or mixtures thereof It can be mentioned.

  Among the above-mentioned additives, it is preferable to add a lubricant in order to improve the handleability during the molding process (decrease in the molding process temperature, adhesion to the molding machine, and prevention of adhesion between the foams). Specific examples of lubricants include fatty acids having 18 to 30 carbon atoms such as stearic acid and behenic acid; fatty acid amides having 18 to 30 carbon atoms such as stearic acid amide, oleic acid amide, and erucic acid amide; stearic acid and behenine And at least one fatty acid lubricant selected from the group consisting of fatty acid metal soaps of 18 to 30 carbon atoms such as acids and alkali metals or alkaline earth metals. The content ratio of the lubricant is preferably 0.1 to 10 parts by mass, and 0.5 to 8 parts by mass, when the total amount of the polymer components contained in the thermoplastic elastomer composition is 100 parts by mass. It is further more preferable and it is especially preferable that it is 1-5 mass parts. When the amount of the lubricant used exceeds 10 parts by mass, the foamability tends to decrease. On the other hand, when the amount of lubricant used is less than 0.1 parts by mass, the effect of addition tends not to be seen.

  The melt tension of the thermoplastic elastomer composition of the present invention is 5.0 cN or more, preferably 7.0 cN or more, more preferably 8.0 cN or more. When the thermoplastic elastomer composition has a melt tension of less than 5.0 cN, when foamed, the expansion ratio is low, independent bubbles are hardly formed, and the shape of the formed bubbles is difficult to be uniform. Therefore, by using a thermoplastic elastomer composition having a melt tension of a predetermined numerical value or higher, it is possible to obtain a foam having a high expansion ratio, a high closed cell property and a uniform foam cell shape.

  Furthermore, the compression set of the thermoplastic elastomer composition of the present invention is 80% or less, preferably 70% or less. When the compression set of the thermoplastic elastomer composition is more than 80%, the foamed rubber obtained is inferior in rubber elasticity and flexibility when foamed. Therefore, it is possible to obtain a foam excellent in rubber elasticity and flexibility by using a thermoplastic elastomer composition whose compression set is a predetermined numerical value or more.

2. Method for producing thermoplastic elastomer composition:
In the thermoplastic elastomer composition of the present invention, for example, (C) a crosslinking agent is added to a mixture containing the component (A) and the component (B-1-1) and / or the component (B-2-1). It can be manufactured by heat treatment. Or after adding (C) crosslinking agent to the mixture containing (A) component and (B-1-2) component, and dynamically heat-treating, (B-1-1) component and / or (B-2) -1) It can also be produced by adding a component.

  In preparing the dynamically heat-treated mixture, the component (A), the component (B-1-1) and / or the component (B-2-1), and the component (B-1-2) are used as they are. You may use, and you may use what was prepared as a composition containing the same or different additive etc., respectively. The shape of the component (A) may be any of a veil shape, a crumb shape, a pellet shape, and a powder shape (including a bale-like rubber or a crushed rubber product). Moreover, you may use combining several (A) component from which a shape differs.

  As a device used for “dynamic heat treatment”, a melt kneader or the like can be cited as a suitable example. The treatment by the melt kneader may be either a continuous type or a batch type. Specific examples of the melt kneader include an open type mixing roll, a non-open type Banbury mixer, a single screw extruder, a twin screw extruder, a continuous kneader, and a pressure kneader. Among these, it is preferable to use a continuous melt kneader such as a single screw extruder, a twin screw extruder, or a continuous kneader from the viewpoint of economy, processing efficiency, and the like. Further, two or more continuous melt-kneading apparatuses of the same type or different types may be used in combination.

  The L / D ratio (ratio between the screw effective length L and the outer diameter D) of the twin screw extruder is preferably 30 or more, and more preferably 36 to 60. In addition, as the twin screw extruder, for example, an arbitrary twin screw extruder such as one in which two screws mesh or not mesh can be used, but the rotation direction of the two screws is the same direction. Are more preferable. As such a twin screw extruder, for example, a trade name “PCM” (manufactured by Ikegai Co., Ltd.), a trade name “KTX” (manufactured by Kobe Steel), a trade name “TEX” (manufactured by Nippon Steel Works), a product The name “TEM” (manufactured by Toshiba Machine Co., Ltd.), the product name “ZSK” (manufactured by Warner), and the like can be mentioned.

  The L / D ratio (ratio between the screw effective length L and the outer diameter D) of the continuous kneader is preferably 5 or more, and more preferably 10 or more. Examples of such a continuous kneader include a trade name “Mixtron KTX / LCM / NCM” (manufactured by Kobe Steel), a trade name “CIM / CMP” (manufactured by Nippon Steel).

  The treatment temperature for the dynamic heat treatment is preferably 120 to 350 ° C, and more preferably 150 to 290 ° C. The treatment time is preferably 20 seconds to 320 minutes, more preferably 30 seconds to 25 minutes. Further, the shearing force to be applied is preferably 10 to 20000 / sec, more preferably 100 to 10,000 / sec in terms of shear rate.

3. Foam:
Next, an embodiment of the foam of the present invention will be described. The foam of this embodiment is obtained by foaming any of the above-mentioned thermoplastic elastomer compositions. Therefore, the foam of this embodiment has a high closed cell property and a uniform foam cell shape. Moreover, it is excellent in rubber elasticity, flexibility, and surface appearance.

  The foam of the present invention is obtained by foaming using an inert gas or a chemical foaming agent as described later. However, the foam foamed using an inert gas has no odor because there is no foaming agent residue compared to the foam foamed using a chemical foaming agent, and it is also recyclable and cushioned. Are better.

  The average diameter (average cell diameter) of the bubbles formed in the foam of the present invention is preferably 1 to 200 μm, and more preferably 3 to 150 μm. Outside this range, the cushion feeling tends to decrease. In addition, the average cell diameter of a bubble is the value calculated | required from the magnifier photograph of the cross section of a foam.

  The foam of the present invention has high closed cell properties and a uniform foamed cell shape, and is excellent in rubber elasticity, flexibility and surface appearance. Accordingly, the foam of the present invention is, for example, an automobile interior part such as an instrument panel or a glove box, an automobile exterior part such as a weather strip, a weak electrical part, a vibration isolator for electrical appliances, other industrial parts, a building material, a sport. It is suitable as an article.

4). Production method of foam:
(First foam production method)
Next, an embodiment of the first method for producing a foam of the present invention will be described. The manufacturing method of the 1st foam of this embodiment is a manufacturing method including inject | pouring an inert gas into one of the above-mentioned thermoplastic elastomer compositions, and then foaming.

  In the first method for producing a foam of the present invention, first, an inert gas is injected into the molten thermoplastic elastomer composition. As the inert gas, a gas or a supercritical fluid is preferably used.

  As the supercritical fluid, it is preferable to use carbon dioxide or nitrogen in a supercritical state. For example, in the case of carbon dioxide, a supercritical state can be obtained by setting the temperature to 31 ° C. or higher and the pressure to 7.3 MPa or higher. Carbon dioxide becomes a supercritical state at a relatively low temperature and pressure, and has a high impregnation rate into the molten thermoplastic elastomer composition. Furthermore, since high concentration mixing is possible, it is suitable for foam molding, and fine bubbles can be obtained. As the gas, carbon dioxide, nitrogen, air or the like is preferably used.

  The manufacturing method of the 1st foam of this invention will not be specifically limited if it is a method which can be foam-molded using the said thermoplastic elastomer composition, You may carry out by any method of a batch method and a continuous method. Specific production methods include extrusion molding, injection molding, press molding and the like.

  When a gas or a supercritical fluid is injected into a molten thermoplastic elastomer composition and mixed uniformly, the apparent viscosity is lowered, so that the fluidity is improved. Furthermore, when the thermoplastic elastomer composition is foamed using a gas or a supercritical fluid, the foaming ratio can be increased. Moreover, it is easy to control the average cell diameter of the obtained foam. Moreover, it is easy to control the cushion feeling of the foam obtained. Furthermore, when a gas or a supercritical fluid is used, the average cell diameter of the obtained foam can be reduced.

  When ordinary gas is used, it is difficult to increase the expansion ratio as compared with the case where supercritical fluid is used. However, when a normal gas is used, it is possible to produce a foam with inexpensive equipment.

(Method for producing second foam)
Next, an embodiment of the second method for producing a foam of the present invention will be described. The manufacturing method of the 2nd foam of this embodiment mix | blends 0.01-20 mass parts of chemical foaming agents with respect to 100 mass parts of any of the above-mentioned thermoplastic elastomer compositions, and a chemical foaming agent mixing raw material. And a foaming of the obtained chemical foaming agent mixed raw material.

  In the second method for producing a foam according to the present invention, first, a chemical foaming agent is mixed with a thermoplastic elastomer composition to obtain a chemical foaming agent mixed raw material. A chemical foaming agent will not be specifically limited if it is normally used for foam molding of a resin material. A thermal decomposition type foaming agent, a volatile type foaming agent, a hollow particle type foaming agent, etc. are mentioned, It can select suitably according to a foam preparation method, and can use it. These chemical blowing agents may be used alone or in combination of two or more. Specifically, the trade name “Vinihole AC # 3” (manufactured by Eiwa Kasei Kogyo Co., Ltd.), the trade name “Polyslen EE205” (manufactured by Eiwa Kasei Kogyo Co., Ltd.), and the trade name “EXPANCEL-092 (DU) -120” (Expans) Cell)).

  The compounding amount of the chemical foaming agent is 0.01 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the thermoplastic elastomer composition. To do. When the compounding amount of the chemical foaming agent is less than 0.01 with respect to 100 parts by mass of the thermoplastic elastomer composition, it is difficult to obtain a foam having a sufficient expansion ratio because it is too small. On the other hand, if the compounding amount of the chemical foaming agent is more than 20 parts by mass with respect to 100 parts by mass of the thermoplastic elastomer composition, the surface appearance is inferior.

  Next, the obtained chemical foaming agent mixed raw material is foamed. Although the foaming method is not particularly limited, it can be suitably foamed by a method such as extrusion foaming or injection foaming. Thereby, the foam of this embodiment can be manufactured.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Evaluation of various properties]: Using a pellet-shaped thermoplastic elastomer composition, melt flow rate (MFR) and melt tension were measured. Further, a test piece having a size of 120 mm × 120 mm × 2 mm was obtained by injection molding of the thermoplastic elastomer composition using an injection molding machine (model “J-110AD”, manufactured by Nippon Steel Works). The test piece was used to measure hardness (duro A) and compression set.

  [Intrinsic viscosity [η]]: Using an Ubbelohde viscometer, the intrinsic viscosity [η] (dl / g) of the ethylene copolymer in a decalin solvent at 135 ° C. was measured.

  [Ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn)]: Gel permeation chromatography (trade name “PL-GPC220”, manufactured by Polymer Laboratories) The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) was calculated. The column was a trade name “MIXED-B” manufactured by Polymer Laboratories, the mobile phase was orthodichlorobenzene, the temperature was 135 ° C., the concentration was 0.1%, and the detector was a differential refractometer.

  [Area ratio of a region having a molecular weight of 100,000 or less in terms of polystyrene]: Calculated from the chromatogram obtained by the above-mentioned method of “ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) (Mw / Mn)”. did. In Table 1, “area ratio (%)” is shown.

  [Hardness (Duro A)]: Measured according to JIS K6253 and used as an index of flexibility.

  [Melt flow rate (MFR)]: Measured under conditions of 230 ° C. and 98 N load according to JIS K7210, and used as an index of fluidity.

  [Compression set]: Measured at 70 ° C. for 22 hours in accordance with JIS K6262, and used as an index of rubber elasticity.

[Melt tension]: Melt tension was measured using a melt tension tester type II (manufactured by Toyo Seiki Seisakusho) under the following conditions.
Measurement temperature: 210 ° C
Orifice diameter: 2mmφ
Extrusion speed: 10.0mm / min
Take-off speed: 2.0 m / min

[Foaming ratio]: The specific gravity before foaming and the specific gravity after foaming of the thermoplastic elastomer composition were measured and calculated according to the following formula (3).
Foaming ratio = specific gravity before foaming / specific gravity after foaming (3)

[Foaming property]: The expansion ratio was calculated and evaluated according to the following criteria.
◎: Foaming ratio 5 times or more ○: Foaming ratio 1.5 times or more and less than 5 times ×: Foaming ratio less than 1.5 times

  [Foam surface]: The surface appearance was visually evaluated.

[Foamed cell state]: An enlarged photograph (× 100) of the foam was taken using a magnifying glass, and evaluated visually according to the following criteria.
○: Foamed cells are uniform closed cells, and foamability is good. ×: Foamed cells are uneven or open cells, and foamability is poor.

[Oil bleedness]: The foam was allowed to stand at 100 ° C. for 72 hours, and then the appearance change of the surface of the foam was visually observed to evaluate the softening material retention in the following two stages.
○: Bleeding of mineral oil-based softening material is not observed, softening material retention is good ×: Bleeding of mineral oil-based softening material is observed, softening material retention is inferior

[1] Production of oil-extended ethylene copolymer:
(Production Example 1)
A stainless steel autoclave with an internal volume of 10 liters substituted with nitrogen was used, the polymerization temperature was kept at 22 ° C., and the copolymerization reaction was continuously carried out under a pressure of 1 MPa. In the copolymerization reaction, hexane is continuously supplied from the supply port at the lower part of the autoclave at a rate of 65 L / hour, and ethylene, propylene, and 5-ethylidene-2-norbornene are respectively supplied at 0.80 Nm ^{3 /} hour. , 2.0 L, and 0.11 L continuously. At the same time, ethylaluminum sesquichloride and vanadium trichloride are continuously fed at a rate of 13.585 g and 0.384 g per hour, respectively, and hydrogen as a molecular weight regulator is continuously fed at a rate of 0.4 NL per hour. Supplied. The copolymer obtained by the copolymerization reaction is transferred into a storage machine, and 120 parts of a mineral oil softener (trade name “Diana Process PW90”, manufactured by Idemitsu Kosan Co., Ltd.) is added to 100 parts of this copolymer. After stirring, the target oil-extended ethylene copolymer (a-1) was precipitated by steam stripping.

  The obtained oil-extended ethylene copolymer (a-1) has an intrinsic viscosity [η] of 6.7 dl / g, Mw / Mn of 2.4, and a molecular weight of 100,000 or less in terms of polystyrene. The area ratio of was 0.5%. Moreover, each of the structural unit derived from ethylene, the structural unit derived from propylene, and the structural unit derived from 5-ethylidene-2-norbornene contained in the obtained oil-extended ethylene-based copolymer (a-1) The ratio of was 67%, 26.5%, and 6.5% with respect to 100% of all structural units.

(Synthesis Examples 2, 4, 5)
While adjusting the use amount of ethylene, propylene, 5-ethylidene-2-norbornene, ethylaluminum sesquichloride, and vanadium trichloride, the supply amount of hydrogen, and the polymerization temperature so as to have the content ratio shown in Table 1, Oil-extended ethylene-based copolymers (a-2), (a-4), and (a-5) in the same manner as in Synthesis Example 1 except that the amount of the mineral oil-based softening material shown in 1 was added. ) Was manufactured. Table 1 shows the evaluation results of the produced oil-extended ethylene copolymers (a-2), (a-4), and (a-5).

(Synthesis Example 3)
Ethylene, propylene, and 5-ethylidene-2-norbornene are continuously fed at rates of 0.75 Nm ³ , 1.4 L, and 0.10 L, respectively, and vanadium trichloride is supplied at a rate of 1.216 g / hr. Continuous supply, continuous supply of hydrogen at a rate of 0.06 NL per hour, copolymerization while maintaining the polymerization temperature at 30 ° C., and the blending amount of the mineral oil-based softener is 100 parts Except that, an oil-extended ethylene copolymer (a-3) was produced in the same manner as in Synthesis Example 1 described above. The produced oil-extended ethylene copolymer has an intrinsic viscosity [η] of 4.7, Mw / Mn of 3.7, and an area ratio of a molecular weight of 100,000 or less in terms of polystyrene is 3.2%. Met.

[2] Production of thermoplastic elastomer composition:
Example 1
Oil-extended ethylene-based copolymer (a-1) 35 parts, thermoplastic resin (b-1-1) 55 parts, mineral oil-based softening material (d) 10 parts, and anti-aging agent (e) 0.1 part Was put into a pressure type kneader (capacity: 10 liters, manufactured by Moriyama Co., Ltd.) preheated to 160 ° C. By kneading for 15 minutes at 40 rpm (shear rate 200 / sec) until the thermoplastic resin (b-1-1) was melted and each component was uniformly dispersed, a kneaded material in a molten state was obtained. The obtained kneaded material in a molten state was pelletized using a feeder ruder (manufactured by Moriyama Corporation). 100.1 parts of the pelletized kneaded product, 0.6 part of the crosslinking agent (c-1), and 0.5 part of the crosslinking aid (c-2) were charged into a Henschel mixer and mixed for 30 seconds. Then, twin-screw extruder (same direction fully meshed screw, screw flight part length (L) to screw diameter (D) ratio (L) / (D) = 33.5, trade name “PCM45”, Extruded while performing dynamic heat treatment at a processing time of 180 ° C., residence time of 1 minute 30 seconds, 300 rpm, and shear rate of 400 / sec to produce a pellet-shaped thermoplastic elastomer composition (I) Obtained.

  The thermoplastic elastomer composition (I) obtained had an MFR of 18 g / 10 min and a melt tension of 15 cN. Moreover, the hardness (duro A) measured about the test piece produced using the obtained pellet-shaped thermoplastic elastomer composition (I) was 100, and the compression set was 58%.

(Examples 2-4, Comparative Examples 1-4)
A thermoplastic elastomer composition ((II) to (VII)) was obtained in the same manner as in Example 1 except that the formulation shown in Table 2 was used. Table 2 shows various physical property values measured for the obtained thermoplastic elastomer composition, and various physical property values measured for the test pieces prepared using these. In Comparative Example 3, the value of the intrinsic viscosity [η] of the ethylene copolymer contained in the oil-extended ethylene copolymer (a-5) used was too small, so that the mineral oil-based softening material was separated. Therefore, it was impossible to produce a thermoplastic elastomer composition.

  In addition, the detail of each component used in the case of manufacture of a thermoplastic elastomer composition is shown below.

Thermoplastic resin (b-1-1): crystalline polypropylene, trade name “Newstrain SH9000”, manufactured by Nippon Polypro, density = 0.90 g / cm ³ , MFR (temperature 230 ° C., load 21.2 N) = 0 .3 g / 10 min, melt tension (temperature 210 ° C., take-off speed 2.0 m / min) = 20.0 cN, melt tension (temperature 230 ° C.) = 20.0 cN
Thermoplastic resin (b-1-2-1): crystalline polypropylene, trade name “Novatech FA3EB”, manufactured by Nippon Polypro, density = 0.90 g / cm ³ , MFR (temperature 230 ° C., load 21.2 N) = 10.5 g / 10 min, melt tension (temperature 210 ° C., take-up speed 2.0 m / min) = 1.3 cN
Thermoplastic resin (b-1-2-2): crystalline linear low density polyethylene, trade name “Novatech UF423”, manufactured by Nippon Polyethylene Co., Ltd., density = 0.925 g / cm ³ , MFR (temperature 230 ° C., load 21 .2N) = 0.8 g / 10 min, melt tension (temperature 210 ° C., take-off speed 2.0 m / min) = 2.9 cN
Thermoplastic resin composition (b-2): crystalline linear low density polyethylene content = 50%, hydrogenated diene copolymer content = 50%, density = 0.918 g / cm ³ , MFR (temperature 230 ° C., Load 21.2 N) = 2.5 g / 10 min, compression set = 39%, melt tension (temperature 210 ° C., take-up speed 2.0 m / min) = 8.0 cN

Crosslinking agent (c-1): 5-dimethyl-2,5-di (t-butylperoxy) hexane, trade name “Perhexa 25B-40”, manufactured by NOF Corporation Crosslinking aid (c-2): divinylbenzene , Manufactured by Nippon Steel Chemical Co., Ltd., purity: 81%

  Mineral oil-based softening material (d): trade name “Diana Process Oil PW90”, manufactured by Idemitsu Kosan Co., Ltd., pour point = −15 ° C., kinematic viscosity (40 ° C.) = 95.54 cSt

  Anti-aging agent (e): pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, trade name “Irganox 1010”, manufactured by Ciba Specialty Chemicals

(Discussion)
From the results shown in Table 2, the thermoplastic elastomer compositions of Examples 1 to 4 are superior in balance between melt tension and compression set as compared with the thermoplastic elastomer compositions of Comparative Examples 1 to 4. Can be confirmed.

[3] Production of foam:
(1) Supercritical fluid foaming [Method A]: 20 kg of a thermoplastic elastomer composition is introduced from a hopper of a tandem extrusion foam molding apparatus with a supercritical fluid supply device that operates under the following conditions, and extruded and foamed. A foam was obtained.
First molding machine: 20 kg of hopper input, 70 rpm, heater temperature (cylinder temperature) 240 ° C., cylinder pressure 15 MPa
Supercritical fluid: carbon dioxide, supercritical fluid supply (supercritical fluid concentration): 3% by mass
Second molding machine: rotation speed 10 rpm, heater temperature (in-cylinder temperature), most upstream side 180 ° C., most downstream side 152 ° C., cylinder internal pressure 8 MPa
Die: Die temperature 152 ° C, pressure difference 8MPa

(2) Chemical foaming [Method A]: 1 part by mass of a wetting agent and a chemical foaming agent were added to 100 parts by mass of the thermoplastic elastomer composition and mixed with stirring to obtain a master batch. The obtained master batch was converted into a single-screw extruder having a diameter of 40 mm (manufactured by Tanabe Plastics Co., Ltd., L / D = 28, 20 mm wide, 1.5 mm high die T-die, foaming temperature 220 ° C., rotation speed 20 rpm, full A foam was obtained by extrusion foaming.

  [Method B]: 1 part by mass of a wetting agent and a chemical foaming agent were added to 100 parts by mass of the thermoplastic elastomer composition and mixed with stirring to obtain a master batch. The obtained master batch is put into an injection molding machine (model “IS-90B”, manufactured by Toshiba Machine Co., Ltd., flat plate mold = length 100 mm, width 100 mm, height 3.5 to 6.5 mm, foaming temperature 220 ° C.). The foam was obtained by injection molding and foaming.

  [Method C]: With respect to 100 parts by mass of the thermoplastic elastomer composition, a chemical foaming agent is added using an electric heating roll (manufactured by Kansai Roll Co., Ltd.) set at 160 ° C. and molded into a sheet shape. The sheet | seat which consists of a thermoplastic elastomer composition containing this was obtained. The obtained sheet was put into a 10 cm × 10 cm mold having a thickness of 0.5 cm, and the foam was obtained by heating and pressing with a 220 ° C. electrothermal press molding machine for 10 minutes.

(Example 5)
By using the thermoplastic elastomer composition (I) and foaming according to supercritical fluid foaming [Method A], a foam (Example 5) was obtained. The resulting foam had an expansion ratio of “14 times”, foamability of “◎”, foam surface of “smooth”, foam cell state of “◯”, and oil bleeding property of “◯”.

(Examples 6 to 13, Comparative Examples 5 to 7)
While using each thermoplastic elastomer composition shown in Table 2, it was made to foam in accordance with the foaming method shown in Table 3 to obtain foams (Examples 6 to 13 and Comparative Examples 5 to 7). Table 3 shows the evaluation results of foamability, foam surface, foam cell state, and oil bleeding property of the obtained foam.

  In addition, the detail of the foaming agent used in the case of manufacture of a foam is shown below.

Chemical foaming agent (f-1): thermal decomposition type foaming agent, trade name “Vinhole AC # 3” (manufactured by Eiwa Chemical Industry Co., Ltd., thermal decomposition temperature: 208 ° C.)
Chemical foaming agent (f-2): Thermal decomposition type foaming agent, trade name “Polyslen EE206” (manufactured by Eiwa Chemical Industries, Ltd., thermal decomposition temperature: 200 ° C.)
Chemical foaming agent (f-3): Hollow particle type foaming agent, trade name “EXPANCEL-092 (DU) -120” (manufactured by Expandcel, maximum thermal expansion temperature: 180 ° C.)

(Discussion)
From the results shown in Table 3, the foams of Examples 6 to 13 have a higher foaming ratio, a foamed cell state is uniform, and the surface is smooth and has a surface appearance as compared with the foams of Comparative Examples 5 to 7. It is clear that it is excellent and has excellent softener retention. On the other hand, the foam of Comparative Example 5 has an intrinsic viscosity [η] value of the ethylene copolymer contained in the oil-extended ethylene copolymer, and the value of Mw / Mn is outside the scope of the present invention. Compared to the foam of Example 6, it is inferior in softener retention. Moreover, since the value of Mw / Mn of the ethylene-based copolymer contained in the oil-extended ethylene-based copolymer is outside the scope of the present invention, the foam of Comparative Example 6 is compared with the foam of Example 6. Thus, the softening material retention is inferior. Furthermore, since the foam of Comparative Example 7 has a melt tension value of the thermoplastic elastomer composition outside the range of the present invention, the foamed cell state is not uniform and the surface is rough, and the surface appearance is inferior. Met.

  The foam obtained by foaming the thermoplastic elastomer composition of the present invention is excellent in rubber elasticity, flexibility, and surface appearance, for example, automotive interior parts such as instrument panels and glove boxes, It is suitable for automobile exterior parts such as weather strips, weak electrical parts, anti-vibration materials for electrical appliances, other industrial parts, building materials, sporting goods and the like.

It is a schematic diagram which shows the chromatogram obtained by analyzing an ethylene-type copolymer by a gel permeation chromatography.

Explanation of symbols

1: Elution curve, T1: Time required for elution of a component having a molecular weight of 100,000 converted to polystyrene, S1: Area of a portion detected after elution time T1, S _T : Total area surrounded by elution curve 1 and the horizontal axis

Claims (11)

(A) Oil-extended containing an ethylene copolymer that satisfies the following conditions (1) and (2) and 50 to 150 parts by mass of a mineral oil-based softening material with respect to 100 parts by mass of the ethylene copolymer. An ethylene copolymer;
(B) at least one of (B-1) thermoplastic resin and (B-2) thermoplastic resin composition,
(C) obtained by dynamically heat-treating in the presence of a crosslinking agent,
A thermoplastic elastomer composition having a melt tension of not less than 5.0 cN at 210 ° C. and a take-off speed of 2.0 m / min, and a compression set of 80% or less measured at 70 ° C. for 22 hours in accordance with JIS K6262.
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g.
(2): The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3 or less.   2. The heat according to claim 1, wherein the (A) oil-extended ethylene copolymer is obtained by desolvation from a mixed solution containing the ethylene copolymer, the mineral oil-based softening material, and a solvent. Plastic elastomer composition.   The thermoplastic elastomer composition according to claim 1 or 2, wherein the (B-1) thermoplastic resin is an olefin resin, and the (B-2) thermoplastic resin composition is an olefin resin composition. The melt tension of the thermoplastic resin (B-1) at 210 ° C. and a take-up speed of 2.0 m / min is 3.0 cN or more,
The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the (B-2) thermoplastic resin composition has a melt tension of 3.0 cN or more at 210 ° C and a take-up speed of 2.0 m / min. object.   At least one of the (B) (B-1) thermoplastic resin and the (B-2) thermoplastic resin composition has a melt tension of 3.0 cN or more at 210 ° C. and a take-up speed of 2.0 m / min, JIS K6262. The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the compression set measured at 70 ° C for 22 hours is 60% or less.   The (B-1) thermoplastic resin is at least one of an α-olefin-based crystalline thermoplastic resin and an α-olefin-based amorphous thermoplastic resin, according to any one of claims 1 to 5. Thermoplastic elastomer composition.   The (B-2) thermoplastic resin composition contains at least one of an α-olefin-based crystalline thermoplastic resin and an α-olefin-based amorphous thermoplastic resin, and a hydrogenated diene-based polymer. The thermoplastic elastomer composition as described in any one of 1-6. (A) Oil-extended containing an ethylene copolymer that satisfies the following conditions (1) and (2) and 50 to 150 parts by mass of a mineral oil-based softening material with respect to 100 parts by mass of the ethylene copolymer. An ethylene copolymer;
(B-1-2) At least one of α-olefin-based crystalline thermoplastic resin and α-olefin-based amorphous thermoplastic resin having a melt tension of less than 3.0 cN at 210 ° C. and a take-off speed of 2.0 m / min. A mixture containing heels,
(C) After dynamically heat-treating in the presence of a crosslinking agent,
(B-1-1) a thermoplastic resin having a melt tension of not less than 3.0 cN at 210 ° C. and a take-up speed of 2.0 m / min;
(B-2-1) At least one of a thermoplastic resin composition having a melt tension at 210 ° C. and a take-up speed of 2.0 m / min of 3.0 cN or more,
A method for producing a thermoplastic elastomer composition, comprising adding
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 5.5 to 9.0 dl / g.
(2): The value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3 or less.   The foam obtained by foaming the thermoplastic elastomer composition as described in any one of Claims 1-7.   A method for producing a foam, comprising injecting an inert gas into the melted thermoplastic elastomer composition according to any one of claims 1 to 7, followed by foaming.   A chemical foaming agent mixed raw material was obtained by blending 0.01 to 20 parts by mass of a chemical foaming agent with respect to 100 parts by mass of the thermoplastic elastomer composition according to any one of claims 1 to 7. A method for producing a foam, comprising foaming the chemical foaming agent mixed raw material.

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