JP5221001B2 - Expandable olefinic thermoplastic elastomer composition and foamed product thereof - Google Patents

Description

  The present invention relates to a foamable olefin-based thermoplastic elastomer composition and a foamed product thereof.

  Conventionally, as a method of producing an elastomer foam, a vulcanizing agent and a foaming agent are kneaded with natural rubber or synthetic rubber, and then the kneaded product is molded into a predetermined shape and heated to vulcanize and foam. A method is known in which an elastomer (vulcanized rubber) foam is obtained.

  However, in the method as described above, when the rubber is formed into a predetermined shape by continuous extrusion, it is necessary to perform the step of batch kneading the compound into rubber in advance to obtain a kneaded product before continuous extrusion. In addition, in order to easily supply the kneaded product to the extruder, it is necessary to perform a step of forming the kneaded product into a ribbon shape in advance before continuous extrusion. Thus, the method as described above is disadvantageous in industrial production because the manufacturing process is complicated and a considerable time is required for the vulcanization and foaming processes.

  As a method for solving such a problem, for example, a method using a thermoplastic resin such as ethylene / vinyl acetate copolymer, low density polyethylene, or a thermoplastic elastomer composed of an olefin copolymer rubber and an olefin plastic is used. is there. According to such a method using a thermoplastic resin or a thermoplastic elastomer, the aforementioned steps can be omitted (for example, Patent Document 1).

  Patent Document 2 proposes a resin composition for a foam molded article obtained by mixing an olefin polymer elastomer with an olefin polymer resin having a low crystallization temperature of 10 to 100 ° C. However, in this method, wasteful wrinkles and deformation are likely to occur before the foam is cooled to 100 ° C. or less after foam molding. Further, since a resin having a low crystallization temperature is mixed, there is a problem that a practical temperature range is narrowed.

  Patent Document 3 proposes a foam mainly composed of a thermoplastic elastomer composition obtained by mixing an ethylene / α-olefin copolymer and a polyethylene resin. However, in this method, there is a problem that a flexible foam cannot be obtained due to the high degree of crystallinity of polyethylene, or bleed out when a plasticizer is mixed to impart flexibility, or the practical temperature is lowered. is there.

Furthermore, these thermoplastic resins or thermoplastic elastomers have a problem in that poor appearance tends to occur because they are easily defoamed during foam molding. In addition, even if parts such as weather strips for automobiles or seal members for door-to-door parts that are in contact with people or objects or parts that repeatedly slide are manufactured from foams obtained by conventional methods, wear resistance and It has the disadvantage of being inferior in scratch resistance.
For this reason, it is the reality that the parts used are limited.
JP 2001-139740 A JP 2001-81251 A JP 2001-341589 A

  It solves the problems associated with the prior art, and even when the density ρ of the foam is 700 kg / m 3 or less, there is no rough skin due to defoaming, it has a soft feel, has a fine cell structure, and the appearance of the foam The purpose of the present invention is to provide a foamable olefinic thermoplastic elastomer composition excellent in scratch resistance and abrasion resistance as compared with conventional olefinic thermoplastic elastomers, and a foam obtained therefrom. Yes.

<Overview>
The composition of the present invention and the foam obtained therefrom are
Syndiotactic α-olefin copolymer (a) and other thermoplastic resin (b), and if necessary, an olefin thermoplastic elastomer composition (A) comprising ethylene copolymer rubber (c), And a foaming agent (B), and the crystallization time when measured at 120 ° C. with a differential scanning calorimeter DSC is in the range of 40 to 500 seconds. Product and foam obtained therefrom. Moreover, it is a foaming olefin type thermoplastic elastomer composition whose crystallinity measured with the differential scanning calorimeter is 5 to 25%.
(Here, the syndiotactic α-olefin copolymer (a) is
In ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution, the total absorption intensity at which the absorption of methyl groups of propylene units is observed at about 20.0 to 21.0 ppm based on tetramethylsilane is propylene. An absorption intensity of about 19.0 to 22.0 ppm attributed to methyl is 0.5 or more,
(A-1) a repeating unit derived from propylene;
(A-2) a repeating unit derived from ethylene;
(A-3) a repeating unit derived from at least one olefin selected from olefins having 4 to 20 carbon atoms, and, if necessary,
(A-4) consisting of a repeating unit derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes,
When the total amount of the unit (a-1), the unit (a-2) and the unit (a-3) is 100 mol%, the unit (a-1) is 30 to 79 mol%, the unit (a- 2) It contains 1 to 30 mol% of units and 10 to 50 mol% of the above (a-3) units (however, the total amount of (a-2) units and (a-3) units is 21 to 70). The unit (a-4) is 0 to 30 mol% with respect to 100 mol% of the total amount of the units (a-1), (a-2) and (a-3). It is contained in quantity and is substantially a syndiotactic structure. )
Further, it is desirable that the ethylene copolymer rubber (c) is crosslinked.

Furthermore, the other thermoplastic resin (b) is desirably polypropylene having a melt flow rate in the range of 0.1 to 200 g / 10 min at 230 ° C. and a load of 2.16 kg,
The syndiotactic α-olefin copolymer (a) does not have a melting peak measured by a differential scanning calorimeter (DSC) and has an intrinsic viscosity [η] measured in decalin at 135 ° C. of 0. It is desirable that it is in the range of 01 to 10 dl / g, the molecular weight distribution by GPC is 4 or less, and the glass transition temperature Tg is −5 ° C. or less.

  The syndiotactic α-olefin copolymer (a) may be cross-linked.

  The foaming agent (B) is preferably at least one foaming agent selected from organic or inorganic pyrolytic foaming agents, carbon dioxide, nitrogen and water, and the content of the foaming agent (B) is preferably The amount is preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of the olefinic thermoplastic elastomer composition (A).

  The first-stage foam is preferably obtained by heating the first-stage composition, and the density ρ of the foam is desirably 700 kg / m 3 or less.

  The composition as described above and the foam obtained therefrom are excellent in moldability, heat resistance, rubber elasticity, scratch resistance, wear resistance and flexibility balance.

<Specific Description of the Invention>
Hereinafter, the foamable olefin-based thermoplastic elastomer composition and the foamed body of the present invention will be specifically described. First, the foamable olefinic thermoplastic elastomer composition of the present invention will be described.

  The foamable olefin-based thermoplastic elastomer composition of the present invention comprises a syndiotactic α-olefin-based copolymer (a), another thermoplastic resin (b), and, if necessary, an ethylene-based copolymer rubber. It is composed of an olefinic thermoplastic elastomer (A) comprising (c) and a foaming agent (B), and has a crystallization time of 40 to 500 seconds, preferably 40 when measured at 120 ° C. with a differential scanning calorimeter. It is in the range of ˜400 seconds, more preferably 40 to 300 seconds. When the crystallization time is less than 40 seconds, the allowable range of the foam molding temperature is increased, resulting in frequent appearance defects of the molded foam, and large variations in the density of the foam. When the crystallization time is 500 seconds or more, gas escape occurs immediately after foaming and bubbles cannot be maintained, and a foam having a low density cannot be obtained.

Olefin-based thermoplastic elastomer composition (A)
The olefin-based thermoplastic elastomer (A) comprises a syndiotactic α-olefin-based copolymer (a), another thermoplastic resin (b), and, if necessary, an ethylene-based copolymer rubber (c). A crystallization speed / crystallinity adjusting material (d) is mixed with the composition.

  The composition is syndiotactic α-olefin copolymer (a) 1 to 99 parts by weight, preferably 5 to 95 parts by weight, more preferably 10 to 90 parts by weight, most preferably 50 to 90 parts by weight, Other thermoplastic resins (b) 99-1 parts by weight, preferably 95-5 parts by weight, more preferably 90-10 parts by weight, most preferably 50-10 parts by weight, and optionally syndiotactic 5 to 1000 parts by weight, preferably 10 to 500 parts by weight, of the ethylene copolymer rubber (c) with respect to 100 parts by weight of the total of the α-olefin copolymer (a) and the other thermoplastic resin (b). Part, more preferably 15 to 300 parts by weight.

Syndiotactic α-olefin copolymer (a)
First, the syndiotactic α-olefin copolymer (a) will be described.

The syndiotactic α-olefin copolymer (a) according to the present invention is ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution, and the absorption of methyl groups of propylene units is based on tetramethylsilane. The total absorption intensity observed at about 20.0-21.0 ppm is 0.5 or more of the absorption intensity of about 19.0-22.0 ppm attributed to propylene methyl, preferably 0.6 or more, Preferably, it is 0.7 or more.

This syndiotactic structure is measured as follows. That is, 0.35 g of a sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. After this solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added and charged into an NMR tube having an inner diameter of 10 mm. And ¹³ C-NMR measurement is performed at 120 degreeC using the JEOL GX-500 type | mold NMR measuring apparatus. The number of integration is 10,000 times or more. When the syndiotactic α-olefin copolymer (a) is in such a range, the syndiotactic property is excellent and the transparency, flexibility, and wear resistance tend to be excellent.

  The syndiotactic α-olefin copolymer (a) according to the present invention is derived from an α-olefin having 1 to 30 mol% of ethylene component units, 30 to 79 mol% of propylene component units, and 4 to 20 carbon atoms. The component unit is 10 to 50 mol% (here, the total component unit amount in the copolymer (a) is 100 mol%, and the ethylene component unit and the component unit derived from an α-olefin having 4 to 20 carbon atoms) The total amount is 21 to 70 mol%), preferably 3 to 25 mol% of ethylene component units, 35 to 75 mol% of propylene component units, and 20 to 20 component units derived from α-olefins having 4 to 20 carbon atoms. 45 mol% (wherein the total amount of the component units in the copolymer (a) is 100 mol%, the total amount of ethylene component units and component units derived from α-olefins having 4 to 20 carbon atoms is 25 to 65) Is particularly preferred) 3 to 25 mol% of ethylene component units, 35 to 65 mol% of propylene component units, and 20 to 45 mol% of component units derived from α-olefins having 4 to 20 carbon atoms (wherein the copolymer (a) The total amount of the component units therein is 100 mol%, and the total amount of the ethylene component units and the component units derived from the α-olefin having 4 to 20 carbon atoms is 35 to 65 mol%), more preferably the ethylene component units. 5 to 25 mol%, propylene component unit is contained in 40 to 65 mol%, and component unit derived from α-olefin having 4 to 20 carbon atoms is contained (herein in the copolymer (I)) The total amount of the ethylene component unit and the component unit derived from an α-olefin having 4 to 20 carbon atoms is 35 to 60 mol%, with the total component unit amount being 100 mol%). Further, it is derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes with respect to 100 mol% of the total amount of ethylene component units, propylene component units, and component units derived from α-olefins having 4 to 20 carbon atoms. The repeating unit may be contained in an amount of 0 to 30 mol%, preferably 0 to 25 mol%. In such an amount, an ethylene component, a propylene component, a component derived from an α-olefin having 4 to 20 carbon atoms, and a component derived from at least one polyene selected from a conjugated polyene and a nonconjugated polyene used as necessary are contained. The syndiotactic α-olefin copolymer (a) has good compatibility with the thermoplastic resin, and the resulting syndiotactic α-olefin copolymer has sufficient transparency, flexibility, rubber There is a tendency to exhibit elasticity and wear resistance.

  The α-olefin used when preparing such a syndiotactic α-olefin copolymer (a) is not particularly limited as long as it has a carbon number of 4 to 20, preferably 4 to 12. These may be linear or branched.

  Specific examples of such α-olefins include 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptane, 1-octene, 1-nonene, 1-decene, 1-decene, Undecene, 1-dodecene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4, Examples include 4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, and the like. 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-1- Pentene is preferred, 1-butene, 1-hexene, 1-octene and 1-decene are preferred, and 1-butene is particularly preferred. These α-olefins can be used alone or in combination of two or more. For example, one α-olefin (i) selected from α-olefins having 4 to 20 carbon atoms and α-olefins selected from the α-olefins having 4 to 20 carbon atoms and different from the above (B) can be used in an amount ratio of (b) / (b) = (50 to 99 mol%) / (1 to 50 mol%) ((b) + (b) = 100 mol%). .

  The repeating unit derived from at least one polyene selected from a conjugated polyene and a non-conjugated polyene used in preparing the syndiotactic α-olefin copolymer (a) includes the following conjugated polyene and non-conjugated It is a repeating unit derived from at least one polyene selected from polyenes.

  Specific examples of the conjugated polyene include 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 1,3-octadiene, 1-phenyl-1,3-butadiene, 1- Phenyl-2,4-pentadiene, isoprene, 2-ethyl-1,3-butadiene, 2-propyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-pentyl-1,3-butadiene, Conjugated dienes such as 2-hexyl-1,3-butadiene, 2-heptyl-1,3-butadiene, 2-octyl-1,3-butadiene, 2-phenyl-1,3-butadiene; 1,3,5- Examples thereof include conjugated trienes such as hexatriene. Of these, butadiene, isoprene, pentadiene, hexadiene, and octadiene are preferable, and butadiene and isoprene are particularly preferable in terms of excellent copolymerizability.

Specific examples of non-conjugated polyenes include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4- Ethyl-1,4-hexadiene, 5-methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5- Ethyl-1,5-heptadiene, 4-methyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-ethyl-1,4-octadiene, 5-ethyl-1,4-octadiene, 5- Methyl-1,5-octadiene, 6-methyl-1,5-octadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 6-methyl-1,6-octadiene, 7- Methyl-1,6-octadiene, 6-ethyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene, 4-ethyl-1,4-nonadiene , 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5-nonadiene, 6-ethyl-1,5- Nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 7-methyl-1,7- Nonadiene, 8-methyl-1,7-nonadiene, 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-1,4-decadiene, 5-methyl-1,5- Decadiene, 6-methyl-1,5-decadiene, 5-ethyl-1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6-decadiene, 7-methyl-1,6- Decadiene, 6-ethyl-1,6-decadiene, 7-ethyl-1,6-decadiene, 7-methyl-1,7-decadiene, 8-methyl-1,7-decadiene, 7-ethyl-1,7- Decadiene, 8-ethyl-1,7-decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethyl-1,8-decadiene, 9-me Non-conjugated dienes such as Le 1,8 undecadiene;
6,10-dimethyl-1,5,9-undecatriene, 4,8-dimethyl-1,4,8-decatriene, 5,9-dimethyl-1,4,8-decatriene, 6,9-dimethyl- 1,5,8-decatriene, 6,8,9-trimethyl-1,5,8-decatriene, 6-ethyl-10-methyl-1,5,9-undecatriene, 4-ethylidene-1,6- Octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 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-1,6-nonadiene, 4-ethylidene-1,6-decadiene, 7-methyl-4-ethylidene-1,6-decadiene, 7-methyl-6-propyl-4-ethylidene-1,6-octadiene, 4-ethylidene-1,7-nonadiene, 8-methyl-4-ethylidene- Non-conjugated trienes such as 1,7-nonadiene and 4-ethylidene-1,7-undecadiene It is below.
Such non-conjugated polyene is preferable in that it has excellent wear resistance when crosslinked.

  Among these, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene (DCPD), 4,8-dimethyl-1,4,8-decatriene (DMDT), 4-ethylidene-8- Methyl-1,7-nonadiene (EMND) is preferred. (A-4) Two or more types of units may be contained.

  In the syndiotactic α-olefin copolymer (a), a component unit derived from an aromatic vinyl compound such as styrene, a component unit derived from the polyene unsaturated compound (polyene) having two or more double bonds. , Component units composed of alcohol, carboxylic acid, amine, and derivatives thereof may be included.

  The syndiotactic α-olefin copolymer (a) has an intrinsic viscosity [η] measured in decalin at 135 ° C. of usually 0.01 to 10 dl / g, preferably 0.05 to 10 dl / g. It is desirable to be. When the intrinsic viscosity [η] of the syndiotactic α-olefin copolymer (a) is within the above range, the properties such as weather resistance, ozone resistance, heat aging resistance, low temperature characteristics, dynamic fatigue resistance, etc. It is a syndiotactic α-olefin copolymer excellent in.

  This syndiotactic α-olefin copolymer (a) has a single glass transition temperature, and the glass transition temperature Tg measured by a differential scanning calorimeter (DSC) is usually −5 ° C. or less, preferably Is preferably in the range of −10 ° C. or lower, particularly preferably −15 ° C. or lower. When the glass transition temperature Tg of the syndiotactic α-olefin copolymer (a) is within the above range, the cold resistance and the low temperature characteristics are excellent.

The molecular weight distribution measured by GPC (Mw / Mn, polystyrene conversion, Mw: weight average molecular weight, Mn: number average molecular weight) is 4.0 or less, preferably 1.5 to 3.0. Within this range, transparency, scratch resistance, and impact resistance are improved, which is preferable.
Moreover, it is desirable that there is no melting peak measured by a differential scanning calorimeter (DSC). In this case, it is excellent in flexibility, scratch resistance, transparency, and whitening resistance.

[Production of Syndiotactic α-Olefin Copolymer (a)]
Such a syndiotactic structure α-olefin copolymer (a) can be obtained by copolymerizing propylene, ethylene and α-olefin in the presence of a metallocene catalyst shown below.

As such a metallocene catalyst,
(X) a transition metal compound represented by the following general formula (1);
(Y) (y-1) a compound that reacts with the transition metal M in the transition metal compound (z) to form an ionic complex,
(Y-2) an organoaluminum oxy compound,
(Y-3) at least one catalyst system comprising at least one compound selected from organoaluminum compounds.

[In the formula (1), M is Ti, Zr, Hf, Rn, Nd, Sm or Ru, and Cp ¹ and Cp ² are cyclopentadienyl group, indenyl group, fluorenyl group π-bonded to M, Or a derivative group thereof, X ¹ and X ² are anionic ligands or neutral Lewis base ligands, and Z is a C, O, B, S, Ge, Si or Sn atom, or these A group containing an atom. ]

Among the transition metal compounds represented by the general formula (1), a transition metal compound in which Cp ¹ and Cp ² are different groups can be mentioned, and more preferably any one group of Cp ¹ and Cp ² Transition metal compounds in which is a cyclopentadienyl group or a derivative group thereof and the other group is a fluorenyl group or a derivative group thereof. Among these, it is preferable that either one of Cp ¹ and Cp ^{2 is} a cyclopentadienyl group or a derivative group thereof, and the other group is a fluorenyl group or a derivative group thereof.

  In the present invention, as the catalyst for producing the syndiotactic α-olefin copolymer (a), a metallocene catalyst as described above is preferably used, but in some cases, other than the metallocene catalyst, conventionally, A known titanium catalyst comprising a solid titanium catalyst component and an organoaluminum compound, or a vanadium catalyst comprising a soluble vanadium compound and an organoaluminum compound can also be used.

  In the present invention, in the presence of the metallocene catalyst as described above, at least one polyene selected from ethylene, propylene and α-olefin, and optionally conjugated polyene and non-conjugated polyene is copolymerized in a normal liquid phase. . At this time, a hydrocarbon solvent is generally used, but propylene may be used as a solvent. Copolymerization can be carried out by either a batch method or a continuous method.

  When a metallocene catalyst is used and copolymerization is carried out by a batch method, the transition metal compound (x) in the polymerization system is usually 0.00005 to 1 mmol, preferably 0.0001 to 1 liter per polymerization volume. The amount used is 0.5 mmol.

  The ionized ionic compound (y-1) is a molar ratio of the ionized ionic compound to the transition metal compound (x) ((y-1) / (x)), and is 0.5 to 20, preferably 1 to 10. Is used in such an amount.

  The organoaluminum oxy compound (y-2) has a molar ratio (Al / M) of aluminum atoms (Al) to transition metal atoms (M) in the transition metal compound (x) of 1 to 10000, preferably 10 to 5000. Is used in such an amount that The organoaluminum compound (y-3) is usually used in an amount of about 0 to 5 mmol, preferably about 0 to 2 mmol, per liter of polymerization volume.

The copolymerization reaction is usually carried out at a temperature in the range of −20 to 150 ° C., preferably 0 to 120 ° C., more preferably 0 to 100 ° C., and a pressure exceeding 0 to 80 kg / cm ² , preferably exceeding 0. In the range of ˜50 kg / cm ² .

  The reaction time (average residence time when polymerization is carried out in a continuous process) varies depending on conditions such as catalyst concentration and polymerization temperature, but is usually 5 minutes to 3 hours, preferably 10 minutes to 1.5 hours. It is.

  Ethylene, propylene and α-olefin are respectively supplied to the polymerization system in such an amount that a syndiotactic α-olefin copolymer (a) having a specific composition as described above can be obtained. In the copolymerization, a molecular weight regulator such as hydrogen can be used. When ethylene, propylene, and α-olefin are copolymerized as described above, the syndiotactic α-olefin copolymer (a) is usually obtained as a polymerization liquid containing the same. This polymerization solution is treated by a conventional method to obtain a syndiotactic α-olefin copolymer (a).

Other thermoplastic resins (b)
The thermoplastic resin (b) other than the syndiotactic α-olefin copolymer (a) according to the present invention has a melting point of 50 ° C. or higher, preferably 80 ° C. or higher, or a glass transition when no melting point exists. Any thermoplastic resin having a point of 40 ° C. or higher, preferably 80 ° C. or higher can be used without particular limitation.

  Other thermoplastic resins (b) according to the present invention include, for example, crystalline thermoplastic resins such as polyolefin, polyamide, polyester, polyacetal, soft vinyl chloride, polyamide elastomer, polyester elastomer, polyurethane elastomer, polystyrene, acrylonitrile-butadiene-styrene. An amorphous thermoplastic resin such as a copolymer (ABS), polycarbonate, polyphenylene oxide or the like is used.

  Among these, polyolefin is most preferable, and specific examples of suitable raw material olefins for polyolefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl. -1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene and the like. These olefins may be used alone or in combination of two or more. Examples of such polyolefins include olefin homopolymers such as polyethylene, polypropylene, poly-1-butene, polymethylpentene, and polymethylbutene, and olefin copolymers such as propylene / ethylene random copolymer. Among them, polypropylene, poly-1-butene, polymethylpentene, propylene / ethylene random copolymer, and propylene / ethylene block copolymer are preferable, and the melt flow rate at 230 ° C. and a load of 2.16 kg is preferably 0.1. Most preferred is polypropylene which is ~ 200 g / 10 min.

    As the polypropylene, either isotactic polypropylene or syndiotactic polypropylene may be used.

  The thermoplastic resins as described above may be used alone or in combination of two or more. Furthermore, a thermoplastic resin other than the above may be used together with the above thermoplastic resin.

Ethylene copolymer rubber (c)
The ethylene copolymer rubber (c) used in the present invention is an amorphous random elastic copolymer rubber comprising ethylene and an α-olefin having 3 to 20 carbon atoms, or ethylene and 3 to 3 carbon atoms. It is an amorphous random elastic copolymer rubber composed of 20 α-olefins and non-conjugated polyene.

  The ethylene / α-olefin molar ratio of such an ethylene copolymer (c) is usually 40/60 to 85/15, and among these, those in the range of 60/40 to 83/17 are preferred.

  Specific examples of the non-conjugated polyene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, and vinyl norbornene. Of these, ethylene / propylene / non-conjugated diene copolymer rubber and ethylene / 1-butene / non-conjugated diene copolymer rubber are preferred, and ethylene / propylene / non-conjugated diene copolymer rubber, particularly ethylene / propylene. -Ethylidene norbornene copolymer rubber and ethylene / propylene / vinyl norbornene copolymer rubber are particularly preferable.

  The Mooney viscosity [ML1 + 4 (100 ° C.)] of the ethylene copolymer rubber (c) used in the present invention is preferably in the range of 50 to 300, preferably 100 to 200.

  Moreover, it is preferable that the iodine number of this ethylene-type copolymer rubber (c) is 3-30, and it is especially preferable that it exists in the range of 5-25.

  The ethylene copolymer rubber (c) used in the present invention may be a so-called oil-extended product containing a softening agent. As the softening agent that can be used for the oil-extended product, a softening agent that is usually used for rubber can be used.

Specifically, petroleum-based substances such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and petroleum jelly;
Synthetic oils such as low molecular weight ethylene / α-olefin random copolymers;
Coal tars such as coal tar and coal tar pitch;
Fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil, coconut oil;
Waxes such as tall oil, beeswax, carnauba wax, lanolin;
Fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate or metal salts thereof;
Synthetic polymer materials such as petroleum resin, coumarone indene resin, atactic polypropylene;
Ester plasticizers such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate;
Other examples include microcrystalline wax, sub (factis), liquid polybutadiene, modified liquid polybutadiene, and liquid thiocol.
Among these softeners, paraffinic process oils or low-molecular-weight ethylene / α-olefin random copolymers are particularly preferred, and high-viscosity paraffinic process oils with a low content of low-molecular-weight components that tend to volatilize are particularly preferred. Particularly preferred. Here, the high-viscosity type means one having a kinematic viscosity at 40 ° C. in the range of 100 to 10,000 centistokes.

  In the present invention, the softening agent is used in a proportion of 150 parts by weight or less, preferably 2 to 100 parts by weight, more preferably 5 to 60 parts by weight with respect to 100 parts by weight of the ethylene copolymer rubber (c). .

  In the present invention, in addition to the ethylene copolymer rubber (c), a rubber other than the ethylene copolymer rubber (c) and the ethylene copolymer rubber (c) within a range not impairing the object of the present invention. Can also be used in combination. Examples of the rubber other than the ethylene copolymer rubber (c) include propylene / ethylene copolymer rubber (propylene content of 60 mol% or more), propylene / α-olefin copolymer rubber, styrene / butadiene rubber, and the like. Examples thereof include hydrogenated products, styrene / isoprene rubber and hydrogenated products thereof, polybutadiene rubber, polyisoprene rubber, nitrile rubber, butyl rubber, polybutylene rubber, natural rubber, and silicone rubber.

Material for adjusting crystallization time and crystallinity (d)
As a result of various studies, the present inventors have found that an olefinic thermoplastic elastomer composition having good foamability can be obtained by optimizing the crystallization time, and have reached the present invention.

  In addition, the olefinic thermoplastic elastomer composition of the present invention has a crystallinity measured by a differential scanning calorimeter of 5 to 25%, preferably 6 to 20%. If the crystallinity is less than 5%, a low-density foam cannot be obtained, or even if it is obtained, the strength of the foam is significantly reduced. When the degree of crystallinity is 25% or more, the flexibility of the foam is poor and the rubber elasticity is lost.

In order to lead the crystallization time and crystallinity of the foamable olefin-based thermoplastic elastomer composition of the present invention to an appropriate range,
The crystallization time is 150 seconds or less, preferably 140 seconds or less, the crystallinity is 50% or more, preferably 55% or more, and the melt flow rate value MFR (ASTM-D-1238-65T, 230 ° C., 2.16 kg load) is 0.1. Olefin-based thermoplastic elastomer contained in olefin-based thermoplastic elastomer composition by melt-kneading olefin-based plastic (d1) in the range of 1-20 g / 10 min, preferably 0.2-15 g / 10 min. (D1) is a partially high molecular weight component having an intrinsic viscosity [η] (measured in decalin at 135 ° C.) of 5 dl / g or more, preferably 5% by mass to 40% by mass, preferably An example is a propylene homopolymer containing 8 to 35% by mass.

  (D1) may be used by mixing olefin plastics having a crystallization time of 150 seconds or more and a crystallinity of less than 50% in accordance with the crystallization time and the crystallinity of the olefin thermoplastic elastomer (A). A crystalline ethylene polymer can also be used as long as the appropriate range of crystallization time and crystallinity is not impaired.

  The olefin plastic (d1) is preferably used in an amount of 1 to 40 parts by weight, more preferably 2 to 35 parts by weight with respect to 100 parts by weight of the foamable olefin thermoplastic elastomer (A).

  In addition, the crystallization time and the crystallization degree of the foamable olefin-based thermoplastic elastomer composition can be led to an appropriate range by using a known crystal nucleating agent (d2) in the present invention. As the crystal nucleating agent, talc, mica, silica, alumina, brominated biphenyl ether, aluminum hydroxydi-tert-butylbenzoate (TBBA), dibenzylidene sorbitol (DBS), substituted, which are commonly used for polyolefin resins DBS, lower alkyl dibenzylidene sorbitol (PDTS), organic phosphate, substituted triethylene glycol terephthalate, Terylene & Nylon fiber, etc., especially 2,2'-methylenebis (4,6-di-tert-butylphenyl) phosphoric acid Sodium, PDTS and fluororesin are preferred. The crystal nucleating agent (d2) is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the olefin plastic in the thermoplastic elastomer composition.

<Other ingredients>
In addition to the syndiotactic α-olefin copolymer (a) and the other thermoplastic resin (b), the ethylene copolymer rubber (c) used as necessary, the composition according to the present invention, Softeners and / or inorganic fillers can be blended.

  As described above, the softening agent may be oil-extended on the ethylene-based copolymer rubber (c), or may be added later without oil-extended. The same softening agent as described above can also be used when adding to the ethylene-based copolymer rubber (c) later without spreading the oil.

  When added later without oil-extended, the amount of the softening agent is combined with the oil-extended, syndiotactic α-olefin copolymer (a) and other thermoplastic resins (b), as required. The total amount of ethylene copolymer rubber (c) used accordingly is 100 parts by weight or less, preferably 3 to 80 parts by weight, more preferably 5 to 50 parts by weight. When the softener is used in the above proportion, the resulting composition has excellent fluidity during molding and does not degrade the mechanical properties of the molded article. In this invention, when the usage-amount of a softener exceeds 100 weight part, it exists in the tendency for the heat resistance of the composition obtained to fall.

Specific examples of the inorganic filler used in the present invention include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, sulfuric acid. Examples include calcium, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass sphere, glass balloon, basic magnesium sulfate whisker, calcium titanate whisker, and aluminum borate whisker.

  In the present invention, the inorganic filler is the sum of the syndiotactic α-olefin copolymer (a) and other thermoplastic resins (b), and the ethylene copolymer rubber (c) used as necessary. The amount is 100 parts by weight or less, preferably 2 to 30 parts by weight with respect to 100 parts by weight. In this invention, when the usage-amount of an inorganic filler exceeds 100 weight part, there exists a tendency for the rubber elasticity of a composition obtained and a moldability to fall.

  Furthermore, conventionally known heat stabilizers, anti-aging agents, weathering stabilizers, antistatic agents, lubricants, and other additives can be added as long as the object of the present invention is not impaired. In particular, the lubricant has the effect of further improving the scratch resistance and wear resistance of the resulting automobile molding, and examples of the lubricant include higher fatty acid amides, metal soaps, waxes, silicone oils, fluoropolymers, and the like. . Among these, higher fatty acid amides, silicone oils, and fluoropolymers are used in the automobile molding according to the present invention. Higher fatty acid amides include saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, and behemic acid amide; unsaturated fatty acid amides such as erucic acid amide, oleic acid amide, brassic acid amide, and elaidic acid amide. Bis-fatty acid amides such as methylene bis-stearic acid amide, methylene bis-oleic acid amide, ethylene bis-stearic acid amide, ethylene bis-oleic acid amide; and the like as dimethyl silicone oil, phenyl methyl silicone oil, alkyl silicone oil , Fluorosilicone oil, tetramethyltetraphenyltrisiloxane, modified silicone oil, and the like, specifically, include polytetrafluoroethylene, vinylidene fluoride copolymer, etc. , Erucic acid amide, oleic acid amide, ethylene bis-oleic acid amide, dimethyl silicone oil, phenyl methyl silicone oil, alkyl silicone oil, polytetrafluoroethylene, vinylidene fluoride copolymer, particularly preferably erucic acid amide, oleic acid amide Dimethyl silicone oil and vinylidene fluoride copolymer are used.

The composition according to the present invention comprises:
Syndiotactic α-olefin copolymer (a) and other thermoplastic resins (b), ethylene copolymer rubber (c) used as necessary, and a softener blended as necessary It is obtained by mixing the inorganic filler and / or additives and / or additives and then dynamically molding the composition obtained by dynamic heat treatment into a desired shape. Here, “dynamically heat-treating” means kneading in a molten state.

  Here, all components may be dynamically heat-treated at once, syndiotactic α-olefin copolymer (a) and other thermoplastic resin (b), ethylene used as necessary Two or more types of the copolymer rubber (c) and a softener and / or an inorganic filler and / or an additive blended as necessary are dynamically heat-treated in advance, and then syndiotactic It mix | blends with 1 or more types among the alpha-olefin copolymer (a) and other thermoplastic resin (b), and the ethylene-type copolymer rubber (c) used as needed, as needed. A softening agent and / or an inorganic filler and / or an additive may be added and dynamically heat-treated again.

  When the dynamic heat treatment is performed in the presence of a crosslinking agent, the ethylene copolymer rubber (c) can be crosslinked. By crosslinking the ethylene copolymer rubber (c), the heat resistance and rubber elasticity of the molding according to the present invention are improved. The syndiotactic α-olefin copolymer (a) can also be crosslinked by performing dynamic heat treatment in the presence of a crosslinking agent. By crosslinking the syndiotactic α-olefin copolymer (a), the heat resistance and rubber elasticity of the molding according to the present invention are improved. In particular, since the syndiotactic α-olefin copolymer (a) contains the (a-4) unit, the crosslinking efficiency is increased, which contributes to improvement in heat resistance and rubber elasticity.

  The crosslinking agent used here is an organic peroxide, phenol resin, sulfur, hydrosilicone compound, amino resin, quinone or its derivative, amine compound, azo compound, epoxy compound, isocyanate, etc., thermosetting type The crosslinking agent generally used with rubber | gum is mentioned. Of these crosslinking agents, organic peroxides are particularly preferred.

Specific examples of the organic peroxide used in the present invention include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2, 5-dimethyl-2,5-di- (tert-butylperoxy) hexyne-3, 1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperbenzoate Tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide, and the like.

  Among these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- in terms of reactivity, odor, and scorch stability Bifunctional organic peroxides such as (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene are particularly preferred. Of these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane is most preferred.

  Such an organic peroxide is used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight with respect to 100 parts by weight of the whole object to be processed.

  In the present invention, in the crosslinking treatment with the organic peroxide, sulfur, p-quinonedioxime, p, p'-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenyl Peroxy crosslinking aids such as guanidine, trimethylolpropane-N, N'-m-phenylenedimaleimide, or divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylol Polyfunctional methacrylate monomers such as propane trimethacrylate and allyl methacrylate, and polyfunctional vinyl monomers such as vinyl butyrate and vinyl stearate can be blended.

  By using such a compound, a uniform and mild crosslinking reaction can be expected. In particular, divinylbenzene is most preferred in the present invention. Divinylbenzene is easy to handle and syndiotactic α-olefin copolymer (A), which is the main component of the cross-linked product, other thermoplastic resin (B), ethylene copolymer rubber (C) It has a good compatibility with the organic peroxide, solubilizes the organic peroxide, and acts as a dispersant for the organic peroxide, so the crosslinking effect by heat treatment is uniform and the balance between fluidity and physical properties A good composition is obtained.

  The amount of the compound such as the above-mentioned crosslinking aid or polyfunctional vinyl monomer is usually 5 parts by weight or less, preferably 0.3 to 3 parts by weight with respect to 100 parts by weight of the whole object to be treated. Used in

  In order to accelerate the decomposition of organic peroxides, tertiary amines such as triethylamine, tributylamine, 2,4,6-tri (dimethylamino) phenol, aluminum, cobalt, vanadium, copper, calcium, zirconium, Decomposition accelerators such as naphthenates such as manganese, magnesium, lead, and mercury may be used.

  The dynamic heat treatment in the present invention is preferably performed in a non-open type apparatus, and is preferably performed in an inert gas atmosphere such as nitrogen or carbon dioxide. The temperature of heat processing is the range of 300 degreeC from melting | fusing point of another thermoplastic resin (B), and is 150-290 degreeC normally, Preferably it is 170 to 270 degreeC. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. The applied shearing force is in the range of 10 to 10,000 sec-1, preferably 100 to 50,000 sec-1, in terms of shear rate.

  As a kneading apparatus, a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader), a uniaxial or biaxial extruder can be used, and a non-open type apparatus is preferable.

  Furthermore, it is desirable that the heat treatment be performed statically in hot air after the dynamic heat treatment as described above. The heat treatment is preferably performed at 80 to 130 ° C. for about 1 to 10 hours. By this heat treatment, residues of the crosslinking agent and the like can be removed, the odor of the obtained product can be reduced, or a product with good fogging properties can be obtained.

Foaming agent (B)
Examples of the foaming agent (B) used in the present invention include organic and inorganic pyrolytic foaming agents; water; solvents such as hydrocarbons and halogenated hydrocarbons; gases such as nitrogen, carbon dioxide, propane, and butane. Pyrolytic foaming agent, water, carbon dioxide, nitrogen and the like are preferable.

  Specific examples of pyrolytic foaming agents include inorganic foaming agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite; N, N'-dimethyl-N, N'-dinitrosotephthale Nitroso compounds such as amide, N, N'-dinitrosopentamethylenetetramine (DPT); azodicarbonamide (ADCA), azobisisobutyronitrile (AZBN), azobiscyclohexylnitrile, azodiaminobenzene, barium azodicarboxy Azo compounds such as benzene; benzenesulfonyl hydrazide (BSH), toluenesulfonyl hydrazide (TSH), p, p'-oxybis (benzenesulfonyl hydrazide) (OBSH), diphenylsulfone-3,3'-disulfonyl hydrazide, etc. Sulfonyl hydrazide compounds; calcium azide, 4 And azide compounds such as 4,4'-diphenyldisulfonyl azide and p-toluenesulfonyl azide.

  The foaming agent (B) is usually used in a proportion of 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the olefinic thermoplastic elastomer composition (A).

  If necessary, a foaming aid can be added. Examples of the foaming aid include compounds containing metals such as zinc, calcium, lead, iron, and barium, citric acid, salicylic acid, phthalic acid, stearic acid, and oxalic acid. Or an organic acid such as urea or a derivative thereof. The foaming assistant is usually used in a proportion of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the olefinic thermoplastic elastomer composition (A). The foaming assistant functions to lower the decomposition temperature of the foaming agent, accelerate the decomposition, and make the bubbles uniform.

  Furthermore, for the purpose of uniformly foaming at a high magnification, an inorganic porous powder that adsorbs inorganic gas (for example, zeolite), a resin that absorbs a large amount of inorganic gas (for example, polycarbonate resin), or a nucleating agent for foaming is blended. You can also

Olefin-based thermoplastic elastomer foam The olefin-based thermoplastic elastomer foam of the present invention is a foam obtained by heating the above-mentioned foamable olefin-based thermoplastic elastomer composition of the present invention.

  In preparing the olefinic thermoplastic elastomer foam of the present invention, first, the syndiotactic α-olefin copolymer (a), the other thermoplastic resin (b) and the crystallization speed / crystallinity adjusting material ( d) and, if necessary, a mixture of the ethylene-based copolymer rubber (c) and a resin or additive blended as necessary in a specific ratio, dynamically heat-treated Thus, an olefinic thermoplastic elastomer composition (A) is prepared. Details of the preparation method of the composition (A) are as described above.

  Next, the olefinic thermoplastic elastomer composition (A) and the foaming agent (B) obtained as described above are blended at a specific ratio as described above, and if necessary, a foaming aid, a wetting agent and the like. Is added to prepare a foamable olefin-based thermoplastic elastomer composition.

  As a method of blending the olefinic thermoplastic elastomer composition (A) and the foaming agent (B), for example, the pellets of the thermoplastic elastomer composition (A) and the foaming agent (B) are once tumbler type Brabender, V type. After kneading with a Brabender, ribbon blender, Henschel mixer or the like, if necessary, a method of kneading with an open type mixing roll, a non-release type Banbury mixer, an extruder, a kneader, a continuous mixer or the like can be mentioned. The weather resistance stabilizer, heat resistance stabilizer, anti-aging agent, pigment, dye and the like may be blended at any stage of the above process.

  Next, as a method for preparing a foam from the foamable olefin-based thermoplastic elastomer composition obtained as described above, extrusion molding, press molding, and injection that are conventionally used to obtain a foam molded product are used. Various molding methods such as molding and calendar molding can be employed.

  As a method of preparing a foam by an extrusion molding method, for example, the foamable composition described above is melted by an extruder, extruded from a die and foamed to form a foam, or foamed in an extruder. There is a method of forming a foam by extruding the composition from a die. The resin temperature during extrusion is preferably in the range of 110 to 250 ° C.

  In addition, as a method of preparing a foam by a press molding method, for example, the above-mentioned foamable composition pellets are inserted into a heated mold of a press molding machine, and a mold pressure is applied or a mold pressure is applied. Alternatively, there is a method of forming a foam by melting and then foaming the composition. The temperature of the mold is preferably in the range of 110 to 250 ° C.

  As a method of preparing a foam by an injection molding method, for example, the above-described foamable composition is heated and melted with an injection molding machine, and then injected into a mold so as to be foamed at a nozzle tip, thereby molding the foam. There is a way to do it. The resin temperature during injection is preferably in the range of 110 to 250 ° C.

  The foam obtained by the foam molding method as described above has excellent rubber properties such as tensile properties, flexibility, and resilience, and is more suitable for recycling than vulcanized rubber.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

(Polymerization Example 1: Synthesis of syndiotactic propylene / butene / ethylene copolymer)
A 2000 ml polymerization apparatus sufficiently purged with nitrogen was charged with 100 ml of dry hexane, 480 g of 1-butene and triisobutylaluminum (1.0 mmol) at room temperature, and then the temperature of the polymerization apparatus was raised to 35 ° C. with propylene. Pressurized to 0.54 MPa and then pressurized to 0.62 MPa with ethylene. Thereafter, a toluene solution in which 0.005 mmol of diphenylmethylene (cyclopentadienyl) fluorenylzirconium dichloride and 1.5 mmol of methylaluminoxane (produced by Tosoh Finechem) in contact with aluminum was added to the inside of the polymerization vessel. Polymerization was performed for 5 minutes while maintaining a temperature of 35 ° C. and an ethylene pressure of 0.62 MPa, and 20 ml of methanol was added to terminate the polymerization. After depressurization, the polymer was precipitated from the polymerization solution in 2 L of methanol and dried under vacuum at 130 ° C. for 12 hours. The obtained polymer was 36.1 g. The composition of the polymer was such that the propylene content was 61.3 mol%, the ethylene content was 10.3 mol%, the 1-butene content was 28.4 mol%, the intrinsic viscosity [η] was 2.67 dl / g, The transition temperature Tg was −27.7 ° C., there was no melting peak, and the molecular weight distribution by GPC was 2.0. In ¹³ C-NMR measured with 1,2,4-trichlorobenzene solution, the total absorption intensity at which the absorption of the methyl group of the propylene unit is observed at about 20.0 to 21.0 ppm based on tetramethylsilane is propylene. It was 0.8 with an absorption intensity of about 19.0 to 22.0 ppm attributed to methyl. )

[Method for measuring crystallization time]
Measured using a Perkin-Elmer DSC7 differential scanning calorimeter (DSC). An olefin-based thermoplastic elastomer composition sample weighed 5.0 ± 0.2 mg was sealed in an aluminum sample pan, and the sample was placed at 200 ° C. for 5 minutes in a nitrogen atmosphere with an inflow of nitrogen gas adjusted to 20 ml / min. Hold and melt, then cool to 120 ° C. and hold at a rate of 320 ° C./min. At this time, the relationship between the calorific value due to crystallization of the sample and time is measured, and the time required to reach half the calorific value of the total calorific value is defined as crystallization time (seconds).

[Measurement method of crystallinity]
Measured using a Perkin-Elmer DSC7 differential scanning calorimeter (DSC). An olefinic thermoplastic elastomer composition sample weighed 5.0 ± 0.2 mg was sealed in an aluminum sample pan, and the sample was held at 200 ° C. for 10 minutes in a nitrogen atmosphere into which nitrogen gas flowed in at 20 ml / min. The temperature is lowered to 10 ° C. at a rate of 10 ° C./min, held for 1 minute, and then raised to 200 ° C. at a rate of 10 ° C./min. The heat of fusion is obtained from the endothermic peak area of the sample at this time, and the crystallinity (percentage) is calculated from the ratio of this value and the heat of fusion of the polypropylene crystal. The value of 146.51 J / g is used for the heat of fusion of complete polypropylene crystals.

  80 parts by weight of syndiotactic propylene / butene / ethylene copolymer obtained in Polymerization Example 1 and isotactic polypropylene (homopolymer, MFR (230 ° C., 2.16 kg load, hereinafter the same)) 0.5 (g / 10 minutes)) 20 parts by weight, 12% by mass of a high molecular weight component having an intrinsic viscosity [η] of 8.5 dl / g, a crystallization time of 75 seconds, a crystallinity of 72%, and a melt flow rate of 3.0 g / 10 minutes homotype polypropylene (PP-1) 20 parts by weight and carbon black masterbatch 1 part by weight (to color black) in a twin screw extruder set at 230 ° C. ) Was obtained. The pellets had a crystallization time of 130 seconds and a crystallinity of 10%.

100 parts by weight of the olefinic thermoplastic elastomer composition (I) obtained as described above, and 3.0 parts by weight of a mixture (I-1) of 50 mol% citric acid and 50 mol% sodium hydrogen carbonate After mixing with a tumbler type brabender, a tubular foam and a flat foam were extruded under the following apparatus conditions. The molding appearance was good and there was no problem.
Molding machine: 40mmφ extruder [manufactured by Toshiba Machine Co., Ltd.]
Maximum cylinder temperature: 190 ° C
Die temperature: 150 ° C
Die: Straight die ・ Tube shaped foam: Die / core = 12.5 mm / 10.0 mm
Take-off speed: 8 m / min The density of the obtained foam was determined using an electronic hydrometer MS-200S manufactured by Mirage Trading. The density ρ of the foam was 500 kg / m 3.

Furthermore, the tip of a 470 g wear indenter made of 45R, SUS was covered with a cotton canvas # 10 using a 2 mm thick test piece of the foam obtained using a Toyo Seiki made by Gakushin Abrasion Tester. The sample was worn at 23 ° C., the number of reciprocations of 100 times, the reciprocation speed of 33 times / min, and the stroke of 100 mm, and the gloss change rate ΔGloss before and after that was determined as follows.
ΔGloss = (Gloss before wear−Gloss after wear) / Gloss before wear × 100
ΔGloss under the above conditions was 7%.

[Comparative Example 1]
Existing isotactic propylene / butene / ethylene copolymer (Intrinsic viscosity [η] measured in decalin at 135 ° C. is 2.5 dl / g, propylene content is 62 mol%, ethylene content is 10 mol%, 1-butene The content is 28 mol%, molecular weight distribution (Mw / Mn) measured by GPC is 2.2) 80 parts by weight and isotactic polypropylene (homopolymer, MFR (230 ° C., 2.16 kg load, the same applies below) 0.5) g / 10 min)) 20 parts by weight and 1 part by weight of carbon 2 black masterbatch (for coloring in black) were kneaded in a twin-screw extruder set at 230 ° C. to obtain pellets of composition (II) . The crystallization time of this pellet was 129 seconds, and the crystallinity was 10%.

  A foam was formed in the same manner as in Example 1 from the obtained composition (II) pellets. Although the molded appearance was good and there was no particular problem, the density ρ of the foam obtained in the same manner as in Example 1 was 750 kg / m 3.

  In addition, the gloss before and after the academic vibration wear test was measured in the same manner as in Example 1. ΔGloss was 65%.

  20 parts by weight of isotactic polypropylene (homopolymer, MFR (230 ° C., 2.16 kg load, the same applies below) 12 (g / 10 min)), ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber oil Exhibit (oil extension 40 parts (oil: mineral oil-based paraffin oil), Mooney viscosity ML1 + 4 (100 ° C.) 70, ethylene content 79 mol%, iodine value 11) pellets 80 parts by weight, A mixture of 0.2 parts by weight of 5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 0.3 parts by weight of divinylbenzene as a crosslinking aid is sufficiently stirred and mixed with a Henschel mixer and set to 160 ° C to 220 ° C. The resulting mixture was fed to a twin-screw extruder and subjected to dynamic crosslinking to produce a pellet of the composition (III).

For 100 parts by weight of the pellet of composition (III),
The syndiotactic propylene / butene / ethylene copolymer obtained in Polymerization Example 35 (35 parts by weight), PP-1 (10 parts by weight), and carbon black masterbatch (1 part by weight) are set to 230 ° C. The resulting mixture was kneaded with a twin-screw extruder to obtain pellets of the composition (IV). The pellets had a crystallization time of 129 seconds and a crystallinity of 15%.

  From the obtained composition (IV) pellets, a foam was molded in the same manner as in Example 1. The molded appearance was good and had no particular problems, and the density ρ of the foam obtained in the same manner as in Example 1 was 550 kg / m 3.

  In addition, the gloss before and after the academic vibration wear test was measured in the same manner as in Example 1. ΔGloss was 15%.

[Comparative Example 2]
With respect to 100 parts by weight of the composition (III) obtained in Example 2, a propylene / butene / ethylene copolymer having an existing isotactic structure (the intrinsic viscosity [η] measured in decalin at 135 ° C. is 2. 5 dl / g, propylene content 62 mol%, ethylene content 10 mol%, 1-butene content 28 mol%, molecular weight distribution (Mw / Mn) measured by GPC is 2.2) 80 parts by weight and PP-1 10 parts by weight Then, 1 part by weight of carbon black masterbatch (for coloring in black) was kneaded with a twin screw extruder set at 230 ° C. to obtain pellets of composition (V). The pellets had a crystallization time of 129 seconds and a crystallinity of 15%.

  A foam was formed in the same manner as in Example 1 from the obtained composition (V) pellets. The molded appearance was good and had no particular problems, but the density ρ of the foam obtained in the same manner as in Example 1 was 790 kg / m 3.

  In addition, the gloss before and after the academic vibration wear test was measured in the same manner as in Example 1. ΔGloss was 83%.

[Comparative Example 3]
In Example 1, 4.5 mass% of ethylene was copolymerized with PP-1 as a comonomer instead of 20 parts by weight, crystallization time 2735 seconds, crystallinity 51%, and melt flow rate 0.5 g / 10 min. This was carried out in the same manner as in Example 1 except that 20 parts by weight of random type polypropylene (PP-4) was used. The pellets had a crystallization time of 1250 seconds and a crystallinity of 4.6%.

  From the resulting composition (VI) pellets, a foam was molded in the same manner as in Example 1. The gloss before and after the Gakushin abrasion test was measured. ΔGloss was 15% and the molding appearance was good and there was no particular problem, but the density ρ of the foam was 730 kg / m 3.

  According to the present invention, it is possible to propose a foam having excellent scratch resistance and abrasion resistance, and excellent moldability, flexibility, rubber elasticity, and recyclability.

Claims (8)

The syndiotactic α-olefin copolymer (a), isotactic polypropylene (b), ethylene copolymer rubber (c), and a crystallization time of 150 seconds or less and a crystallinity of 50% or more, An olefinic thermoplastic elastomer composition (A) containing a propylene polymer (d1) or a crystal nucleating agent (d2), and a foaming agent (B),
The crystallization time when measured at 120 ° C. with a differential scanning calorimeter DSC is in the range of 40 to 500 seconds,
The ethylene copolymer rubber (c) is an ethylene / propylene / ethylidene norbornene copolymer rubber and / or an ethylene / propylene / vinyl norbornene copolymer rubber,
A foamable olefin-based thermoplastic elastomer composition, wherein the ethylene-based copolymer rubber (c) is crosslinked.
(Here, the syndiotactic α-olefin copolymer (a) is
1,2,4-trichlorobenzene solution ¹³ C-NMR measured in the sum of the absorption intensity absorption of methyl group of the propylene units are observed referenced to tetramethylsilane 2 0.0～21.0Ppm is It is 0.5 or more in absorption intensity of 1 9.0～22.0Ppm that will be assigned to propylene methyl,
(A-1) a repeating unit derived from propylene;
(A-2) a repeating unit derived from ethylene;
(A-3) a repeating unit derived from at least one olefin selected from olefins having 4 to 20 carbon atoms, and, if necessary,
(A-4) consisting of a repeating unit derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes,
When the total amount of the unit (a-1), the unit (a-2) and the unit (a-3) is 100 mol%, the unit (a-1) is 30 to 79 mol%, the unit (a- 2) It contains 1 to 30 mol% of units and 10 to 50 mol% of the above (a-3) units (however, the total amount of (a-2) units and (a-3) units is 21 to 70). The unit (a-4) is 0 to 30 mol% with respect to 100 mol% of the total amount of the units (a-1), (a-2) and (a-3). Include in quantity. )   2. The foaming property according to claim 1, wherein the isotactic polypropylene (b) is a polypropylene having a melt flow rate in the range of 0.1 to 200 g / 10 min at 230 ° C. and a load of 2.16 kg. Olefin-based thermoplastic elastomer composition.   The syndiotactic α-olefin copolymer (a) does not have a melting peak measured by a differential scanning calorimeter (DSC) and has an intrinsic viscosity [η] measured in decalin at 135 ° C. of 0. 3. The expandable olefin-based thermoplastic elastomer composition according to claim 1, which has a molecular weight distribution by GPC of 4 or less and a glass transition temperature Tg of −5 ° C. or less in a range of 01 to 10 dl / g.   The expandable olefinic thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the degree of crystallinity measured by a differential scanning calorimeter is 5 to 25%.   The foaming olefin according to any one of claims 1 to 4, wherein the foaming agent (B) is at least one foaming agent selected from organic or inorganic pyrolytic foaming agents, carbon dioxide, nitrogen, and water. -Based thermoplastic elastomer composition.   The foaming agent according to any one of claims 1 to 5, wherein the content of the foaming agent (B) is 0.5 to 20 parts by weight with respect to 100 parts by weight of the olefinic thermoplastic elastomer composition (A). Olefin-based thermoplastic elastomer composition.   The olefin type thermoplastic elastomer foam obtained by heating the foamable olefin type thermoplastic elastomer composition of any one of Claims 1-6. The olefin thermoplastic elastomer foam according to claim 7, wherein the density ρ of the foam is in a range of 700 kg / m ³ or less.