(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2001/0028932 A1
`Akaike et al.
`(43) Pub. Date:
`Oct. 11, 2001
`
`US 2001 0028932A1
`
`(54) OLEFIN-BASED THERMOPLASTIC
`ELASTOMER AND MOLDED PRODUCT
`PRODUCED THEREFROM
`
`(76) Inventors: Osamu Akaike, Tokyo (JP); Asami
`Hirashima, Tokyo (JP), TatsumiTsuji,
`Yokkaichi-shi (JP); Motoko Itou,
`Yokkaichi-shi (JP)
`Correspondence Address:
`Dike, Bronstein, Roberts & Cushman
`Intellectual Property Practice Group
`Edwards & Angell, LLP
`130 Water Street
`Boston, MA 02109 (US)
`
`(21) Appl. No.:
`(22) Filed:
`
`09/819,934
`Mar. 28, 2001
`
`(30)
`
`Foreign Application Priority Data
`
`Mar. 31, 2000 (JP)...................................... 2000-096752
`
`Publication Classification
`(51) Int. CI.7. B32B 3/10; B32B 1/02; B65D 65/22
`S2,
`S.C. ... 428/36.8; 428/43; 428/131;
`428/99
`
`ABSTRACT
`(57)
`An olefin-based thermoplastic elastomer comprises a pro
`pylene-based resin (A) and an olefin-based copolymer rub
`ber (B), and has a ratio (N/SS) of first normal stress
`difference (N) to shear stress (SS) of 0.6:1 to 1.4:1 said first
`normal stress difference (N) and shear stress (SS) being
`determined by Subjecting Said elastomer to Step shear test at
`a temperature of 200° C. and a shear rate of 25.1 sec'. Such
`olefin-based thermoplastic elastomer ShowS eXcellent mold
`ability, transferability of embossed patterns and mechanical
`Strength.
`
`EX1056
`Yita v. MacNeil
`IPR2020-01139
`
`

`

`Patent Application Publication Oct. 11, 2001 Sheet 1 of 3
`Patent Application Publication Oct. 11,2001 Sheet 1 of 3
`
`US 2001/0028932 A1
`US 2001/0028932 Al
`
`2
`2
`
`f
`1
`
`FIG.1(b)
`
`FIG.1(b)
`
`FIG.1(a)
`FIG.1(a)
`
`
`
`FIG.1(c)
`FIG.1(c)
`
`

`

`Patent Application Publication Oct. 11, 2001 Sheet 2 of 3
`Patent Application Publication Oct. 11,2001 Sheet 2 of 3
`
`US 2001/0028932 A1
`US 2001/0028932 Al
`
`FIG.2(a)
`FIG.2(a)
`
`GATE DIRECTION
`GATE DIRECTION
`
`60mm
`60mm
`
`6
`6
`
`30mm
`30mm
`>. 30m
`30m
`
`120mm
`120mm
`
`120mm
`
`FIG.2(b)
`
`
`
`7
`
`m
`
`727,
`
`
`V3:-
`
`5
`
`,
`
`

`

`Patent Application Publication Oct. 11, 2001 Sheet 3 of 3
`Patent Application Publication Oct. 11,2001 Sheet 3 of 3
`
`US 2001/0028932 A1
`US 2001/0028932 Al
`
`FIG.3(a)
`
`2mm
`
`1O
`
`20mm
`
`FIG.3(a)
`
`"m: Z, ZVE
`:
`
`
`
`11
`4mm
`
`
`
`

`

`US 2001/0028932 A1
`US 2001/0028932 Al
`
`Oct. 11, 2001
`Oct. 11, 2001
`
`OLEFIN-BASED THERMOPLASTIC ELASTOMER
`OLEFIN-BASED THERMOPLASTIC ELASTOMER
`AND MOLDED PRODUCT PRODUCED
`AND MOLDED PRODUCT PRODUCED
`THEREFROM
`THEREFROM
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`0001. The present invention relates to an olefin-based
`[0001] The present invention relates to an olefin-based
`thermoplastic elastomer comprising a composition contain
`thermoplastic elastomer comprising a composition contain-
`ing a propylene-based resin and an olefin-based copolymer
`ing a propylene-based resin and an olefin-based copolymer
`rubber, and more particularly, to an olefin-based thermo
`rubber, and more particularly,
`to an olefin-based thermo-
`plastic elastomer which is excellent in moldability, transfer
`plastic elastomer which is excellent in moldability, transfer-
`ability of embossed patterns and mechanical Strength, is
`ability of embossed patterns and mechanical strength, is
`capable of providing a molded product being free from
`capable of providing a molded product being free from
`appearance defects Such as an uneven luster, Weld marks and
`appearance defects such as an unevenluster, weld marks and
`flow marks even when the thickness thereof is varied over a
`flow marks even when the thickness thereof is varied over a
`wide range, and is Suitable for forming automobile interior
`wide range, and is suitable for forming automobile interior
`trims or parts, especially a cover for accommodating an air
`trims or parts, especially a cover for accommodating an air
`bag.
`bag.
`0002. In recent years, thermoplastic elastomers such as
`[0002]
`In recent years, thermoplastic elastomers such as
`Styrene-based elastomers, olefins-based elastomers, polyes
`styrene-based elastomers, olefins-based elastomers, polyes-
`ters-based elastomers, polyamides-based elastomers, poly
`ters-based elastomers, polyamides-based elastomers, poly-
`urethane-based elastomers, etc., which are rubber-like Soft
`urethane-based elastomers, etc., which are rubber-like soft
`materials and exhibit a good moldability compatible with
`materials and exhibit a good moldability compatible with
`that of thermoplastic resins without Valcunization process,
`that of thermoplastic resins without valcunization process,
`have been noticed from the Standpoints of productivity,
`have been noticed from the standpoints of productivity,
`recyclability or the like, and have been extensively used in
`recyclability or the like, and have been extensively used in
`various applications Such as automobile parts, electrical
`various applications such as automobile parts, electrical
`appliances, medical apparatuses or components thereof,
`appliances, medical apparatuses or components thereof,
`electric wires and Sundries. Among these elastomers, com
`electric wires and sundries. Among these elastomers, com-
`positions composed of a propylene-based resin and an
`positions composed of a propylene-based resin and an
`olefin-based copolymer rubber Such as an ethylene-propy
`olefin-based copolymer rubber such as an ethylene-propy-
`lene copolymer rubber or an ethylene-propylene-non-con
`lene copolymer rubber or an ethylene-propylene-non-con-
`jugated diene copolymer rubber, or olefin-based thermoplas
`jugated diene copolymerrubber,or olefin-based thermoplas-
`tic elastomers obtained by kinematically heat-treating the
`tic elastomers obtained by kinematically heat-treating the
`above compositions in the presence of an organic peroxide
`above compositions in the presence of an organic peroxide
`so as to allow the olefin-based copolymer rubber to be
`so as to allow the olefin-based copolymer rubber to be
`croSS-linked and form a partially croSS-linked product, have
`cross-linked and form a partially cross-linked product, have
`been especially noticed as economically useful materials
`been especially noticed as economically useful materials
`because of inexpensiveness thereof. In addition, Since the
`because of inexpensiveness thereof. In addition, since the
`elastomers show an appropriate flexibility and are prevented
`elastomers show an appropriate flexibility and are prevented
`from eliminating embossed patterns thereon even when
`from eliminating embossed patterns thereon even when
`Subjected to thermoforming process, positive Studies have
`subjected to thermoforming process, positive studies have
`been made to apply these elastomers to automobile interior
`been made to apply these elastomers to automobile interior
`trims or parts as alternative materials for conventional Soft
`trims or parts as alternative materials for conventional soft
`vinyl chloride resins.
`vinyl chloride resins.
`0.003 Molded products such as typically automobile inte
`[0003] Molded products such as typically automobile inte-
`rior trims or parts generally include ribs for ensuring a
`rior trims or parts generally include ribs for ensuring a
`mechanical Strength thereof, or other components or fitting
`mechanical strength thereof, or other componentsorfitting
`members for attachment to a base Structure and, therefore,
`members for attachment to a base structure and, therefore,
`has both thin-wall and thick-wall portions therein, resulting
`has both thin-wall and thick-wall portions therein, resulting
`in large change in thickness. Such a thickness change tends
`in large change in thickness. Such a thickness change tends
`to cause appearance defects Such as uneven luster, weld
`to cause appearance defects such as uneven luster, weld
`marks and flow marks on the Surface of the molded product.
`marks and flow marks on the surface of the molded product.
`In particular, Since the olefin-based thermoplastic elastomers
`In particular, since the olefin-based thermoplastic elastomers
`are in the form of not only a mixture but also a partially
`are in the form of not only a mixture but also a partially
`croSS-linked product, non-uniform dispersion or coarse dis
`cross-linked product, non-uniform dispersion or coarse dis-
`persion of cross-linked rubbers tends to be caused. There
`persion of cross-linked rubbers tends to be caused. There-
`fore, molded products produced from Such olefin-based
`fore, molded products produced from such olefin-based
`thermoplastic elastomers are more likely to Suffer from the
`thermoplastic elastomers are more likely to suffer from the
`above-described appearance defects.
`above-described appearance defects.
`0004) To solve problems concerning the above-described
`[0004] To solve problems concerning the above-described
`appearance defects, for example, Japanese Patent Applica
`appearance defects, for example, Japanese Patent Applica-
`tion Laid-Open (KOKAI) No. 8-176394(1996) describes a
`tion Laid-Open (KOKAI) No. 8-176394(1996) describes a
`
`thermoplastic elastomer composition exhibiting a die Swell
`thermoplastic elastomer composition exhibiting a die swell
`ratio of notless than 1.8 at a shear rate of 6.8x10° sec~* and
`ratio of not less than 1.8 at a shear rate of 6.8x10 sec and
`comprising a propylene-based block copolymer resin, a
`comprising a propylene-based block copolymer resin, a
`Specific hydrogenated aromatic vinyl-conjugated diene
`specific hydrogenated aromatic vinyl-conjugated diene
`block copolymer, an ethylene-C-olefin copolymer rubber
`block copolymer, an ethylene-c-olefin copolymer rubber
`and paraffin-based proceSS oils. Also, Japanese Patent Appli
`and paraffin-based processoils. Also, Japanese Patent Appli-
`cation Laid-Open (KOKAI) No. 10-259281 (1998) describes
`cation Laid-Open (KOKAID) No. 10-259281(1998) describes
`a thermoplastic elastomer composition comprising a propy
`a thermoplastic elastomer composition comprising a propy-
`lene-based resin, a Specific hydrogenated aromatic vinyl
`lene-based resin, a specific hydrogenated aromatic vinyl-
`conjugated diene block copolymer and an ethylene-C-olefin
`conjugated diene block copolymer and an ethylene-c-olefin
`copolymer rubber.
`copolymer rubber.
`0005. However, as a result of the present inventors
`[0005] However, as a result of the present
`inventors’
`earnest Studies, it has been found that these conventional
`earnest studies, it has been found that these conventional
`thermoplastic elastomer compositions fail to fully Satisfy
`thermoplastic elastomer compositions fail to fully satisfy
`requirements Such as reduction in thickness of molded
`requirements such as reduction in thickness of molded
`products due to recent tendency toward light-weight auto
`products due to recent tendency toward light-weight auto-
`mobile parts, or enlargement in size of molded products due
`mobile parts, or enlargementin size of molded products due
`to recent tendency toward reduced number of parts, espe
`to recent tendency toward reduced numberof parts, espe-
`cially Such a requirement that molded products having a
`cially such a requirement that molded products having a
`large change in thickness, e.g., an airbag cover having a thin
`large change in thickness,e.g., an air bag cover having a thin
`wall portion with a thickneSS as Small as not more than 1 mm
`wall portion with a thickness as small as not more than 1 mm
`for inflation or deployment of an air bag received therein,
`for inflation or deployment of an air bag received therein,
`should be free from appearance defects Such as uneven
`should be free from appearance defects such as uneven
`luster, Weld marks, flow marks or the like.
`luster, weld marks, flow marksor the like.
`0006 Under the circumstances, it has been found that the
`[0006] Under the circumstances,it has been found that the
`Specified olefin-based thermoplastic elastomer obtained by
`specified olefin-based thermoplastic elastomer obtained by
`mixing a propylene-based resin and an olefin-based copoly
`mixing a propylene-based resin and an olefin-based copoly-
`mer rubber and having a specific ratio (N/SS) of first
`mer rubber and having a specific ratio (N,/SS) of first
`normal stress difference (N) to shear stress (SS), shows
`normal stress difference (N,) to shear stress (SS), shows
`excellent moldability, transferability of embossed patterns
`excellent moldability, transferability of embossed patterns
`and mechanical Strength. The present invention has been
`and mechanical strength. The present invention has been
`attained based on the finding.
`attained based on the finding.
`SUMMARYOF THE INVENTION
`SUMMARY OF THE INVENTION
`0007 An object of the present invention is to provide an
`[0007] An object of the present invention is to provide an
`olefin-based thermoplastic elastomer comprising a compo
`olefin-based thermoplastic elastomer comprising a compo-
`Sition containing a propylene-based resin and an olefin
`sition containing a propylene-based resin and an olefin-
`based copolymer rubber, which is not only excellent in
`based copolymer rubber, which is not only excellent in
`moldability, transferability of embossed patterns and
`moldability,
`transferability of embossed patterns
`and
`mechanical Strength, but also capable of providing a molded
`mechanical strength, but also capable of providing a molded
`product being free from appearance defects Such as uneven
`product being free from appearance defects such as uneven
`luster, Weld marks and flow markS.
`luster, weld marks and flow marks.
`0008 To accomplish the aim, in a first aspect of the
`[0008]
`To accomplish the aim,
`in a first aspect of the
`present invention, there is provided an olefin-based thermo
`present invention, there is provided an olefin-based thermo-
`plastic elastomer comprising a propylene-based resin (A)
`plastic elastomer comprising a propylene-based resin (A)
`and an olefin-based copolymer rubber (B), and exhibiting a
`and an olefin-based copolymer rubber (B), and exhibiting a
`ratio (N/SS) of first normal stress difference (N) to shear
`ratio (N,/SS) of first normal stress difference (N,) to shear
`stress (SS) of 0.6:1 to 1.4:1 wherein the first normal stress
`stress (SS) of 0.6:1 to 1.4:1 wherein the first normal stress
`difference (N) and shear stress (SS) are determined by
`difference (N,) and shear stress (SS) are determined by
`Subjecting the elastomer to Step shear test at a temperature
`subjecting the elastomer to step shear test at a temperature
`of 200° C. and a shear rate of 25.1 sec’.
`of 200° C. and a shear rate of 25.1 sec'.
`0009. In a second aspect of the present invention, there is
`[0009]
`Ina second aspect of the present invention, there is
`provided a molded product formed from said olefin-based
`provided a molded product formed from said olefin-based
`thermoplastic elastomer as defined in the above-mentioned
`thermoplastic elastomer as defined in the above-mentioned
`first aspect, having an opening and/or a flat base plate
`first aspect, having an opening and/or a flat base plate
`comprising:
`comprising:
`0010 a thin-wall portion having a thickness in the
`[0010]
`a thin-wall portion having a thickness in the
`range of from 5 to 50% of a thickness of said flat base
`range of from 5 to 50% ofa thicknessof said flat base
`plate, a thick-wall portion having a thickness in the
`plate, a thick-wall portion having a thickness in the
`range of from 110 to 200% of the thickness of said
`range of from 110 to 200% of the thickness of said
`flat base plate, and/or
`flat base plate, and/or
`
`

`

`US 2001/0028932 A1
`US 2001/0028932 Al
`
`Oct. 11, 2001
`Oct. 11, 2001
`
`0011 a rib having a thickness in the range of from
`{0011]
`a rib having a thickness in the range of from
`5 to 200% of the thickness of said flat base plate.
`5 to 200% of the thickness of said flat base plate.
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`0012 FIG. 1(a) is a sectional view showing a thin-wall
`[0012] FIG. 1(a) is a sectional view showing a thin-wall
`portion of a molded product produced from an olefin-based
`portion of a molded product produced from an olefin-based
`thermoplastic elastomer according to the present invention;
`thermoplastic elastomer according to the present invention;
`FIG. 1(b) is a sectional view showing a thick-wall portion
`FIG. 1() is a sectional view showing a thick-wall portion
`of the molded product shown in FIG. 1(a); and FIG.1(c) is
`of the molded product shown in FIG.1(a); and FIG.1(c)is
`a Sectional view showing a rib of the molded product shown
`a sectional view showing a rib of the molded product shown
`in FIG. 1(a).
`in FIG. 1(@).
`0013 FIG. 2(a) is a top plan view showing a test piece
`[0013] FIG. 2(a) is a top plan view showing a test piece
`for evaluation of uneven luster and weld marks which is
`for evaluation of uneven luster and weld marks which is
`produced from an olefin-based thermoplastic elastomer
`produced from an olefin-based thermoplastic elastomer
`according to the present invention; and FIG. 2(b) is a
`according to the present
`invention; and FIG. 2(b) is a
`sectional view taken along the line A-A of FIG. 2(a).
`sectional view taken along the line A-A of FIG.2(a).
`0014 FIG. 3(a) is a top plan view showing another test
`[0014] FIG. 3(a) is a top plan view showing anothertest
`piece for evaluation of uneven luster and weld marks which
`piece for evaluation of uneven luster and weld marks which
`is produced from an olefin-based thermoplastic elastomer
`is produced from an olefin-based thermoplastic elastomer
`according to the present invention; and FIG. 3(b) is a
`according to the present
`invention; and FIG. 3(b) is a
`sectional view taken along the line B-B of FIG. 3(a).
`sectional view taken along the line B-B of FIG.3(a).
`DETAILED DESCRIPTION OF THE
`DETAILED DESCRIPTION OF THE
`INVENTION
`INVENTION
`0.015. In the present invention, examples of the propy
`In the present invention, examples of the propy-
`[0015]
`lene-based resins as the component (A) contained in the
`lene-based resins as the component (A) contained in the
`olefin-based thermoplastic elastomer may include propylene
`olefin-based thermoplastic elastomer may include propylene
`homopolymer, or copolymers of propylene with the other
`homopolymer, or copolymers of propylene with the other
`C-olefin having about 2 to about 10 carbon atoms Such as
`a-olefin having about 2 to about 10 carbon atoms such as
`ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-me
`ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-me-
`thyl-1-pentene, 1-hexene, 4-methyl-l-hexene, 1-heptene,
`thyl-1-pentene, 1-hexene, 4-methyl-l-hexene, 1-heptene,
`1-octene and 1-decene. Specific examples of the propylene
`1-octene and 1-decene. Specific examples of the propylene-
`based resins may include propylene-ethylene copolymers,
`based resins may include propylene-ethylene copolymers,
`propylene-1-butene copolymers, propylene-ethylene-1-
`propylene-1-butene
`copolymers,
`propylene-ethylene-1-
`butene copolymers, propylene-4-methyl-1-pentene copoly
`butene copolymers, propylene-4-methyl-1-pentene copoly-
`merS or the like. Among these propylene-based resins,
`mers or the like. Among these propylene-based resins,
`propylene homopolymer and propylene-ethylene copoly
`propylene homopolymer and propylene-ethylene copoly-
`mers are preferred. The ethylene content of the propylene
`mers are preferred. The ethylene content of the propylene-
`ethylene copolymers is preferably not more than 15% by
`ethylene copolymers is preferably not more than 15% by
`weight, more preferably not more than 10% by weight. The
`weight, more preferably not more than 10% by weight. The
`lower limit thereof is preferably 1% by weight.
`lower limit thereof is preferably 1% by weight.
`0016. The propylene-based resin used in the present
`[0016] The propylene-based resin used in the present
`invention may be produced by any polymerization methods
`invention may be produced by any polymerization methods
`using either Ziegler catalysts or metallocene catalysts.
`using either Ziegler catalysts or metallocene catalysts.
`Among these methods, those using metallocene catalysts are
`Amongthese methods, those using metallocenecatalysts are
`preferred.
`preferred.
`0.017. Meanwhile, the polymerization methods for the
`[0017] Meanwhile,
`the polymerization methods for the
`production of propylene-based resins using metallocene
`production of propylene-based resins using metallocene
`catalysts have been already known in the arts. For example,
`catalysts have been already knownin the arts. For example,
`the propylene-based resin may be produced by polymerizing
`the propylene-based resin may be produced by polymerizing
`propylene, etc. in the presence of a metallocene catalyst
`propylene, etc. in the presence of a metallocene catalyst
`comprising (a) a cyclopentadienyl group-containing com
`comprising (a) a cyclopentadienyl group-containing com-
`pound of a transition metal Such as titanium, Zirconium and
`pound ofa transition metal such as titanium, zirconium and
`hafnium, (b) an aluminum oxy compound, a Lewis acid, an
`hafnium,(b) an aluminum oxy compound, a Lewisacid, an
`ionic compound capable of reacting with the component (a)
`ionic compoundcapable of reacting with the component(a)
`to convert the component (a) into a cation, or clays, clay
`to convert the component (a) into a cation, or clays, clay
`minerals and an ion-exchanging layer compound, and, if
`minerals and an ion-exchanging layer compound, and, if
`required, (c) an organoaluminum compound, by vapor-phase
`required, (c) an organoaluminum compound,by vapor-phase
`polymerization method, bulk polymerization method, Solu
`polymerization method, bulk polymerization method, solu-
`tion polymerization method or the like.
`tion polymerization methodorthe like.
`0.018. The propylene-based resin used in the present
`[0018] The propylene-based resin used in the present
`invention preferably has a ratio (MW/Mn) of weight-average
`invention preferably has a ratio (Mw/Mn) of weight-average
`
`molecular weight (Mw) to number-average molecular
`molecular weight
`(Mw)
`to number-average molecular
`weight (Mn) of 2.5:1 to 4.0:1, more preferably 2.5:1 to 3.5:1,
`weight (Mn)of 2.5:1 to 4.0:1, more preferably 2.5:1 to 3.5:1,
`when measured by gel permeation chromatography. When
`when measured by gel permeation chromatography. When
`the ratio (MW/Mn) of weight-average molecular weight
`the ratio (Mw/Mn) of weight-average molecular weight
`(Mw) to number-average molecular weight (Mn) is less than
`(Mw) to number-average molecular weight (Mn) is less than
`2.5:1, the obtained olefin-based thermoplastic elastomer
`2.5:1,
`the obtained olefin-based thermoplastic elastomer
`may exhibit a small first normal stress difference (N) which
`may exhibit a small first normal stress difference (N,) which
`is determined by the Step shear test as described in detail
`is determined by the step shear test as described in detail
`hereinafter. As a result, the ratio (N/SS) of the first normal
`hereinafter. As a result, the ratio (N,/SS) of the first normal
`stress difference (N) to the shear stress (SS) is too low, so
`stress difference (N,) to the shear stress (SS) is too low, so
`that flow marks may tend to be caused. On the other hand,
`that flow marks may tend to be caused. On the other hand,
`when the ratio (MW/Mn) of weight-average molecular
`when the ratio (Mw/Mn) of weight-average molecular
`weight (Mw) to number-average molecular weight (Mn) is
`weight (Mw) to number-average molecular weight (Mn) is
`more than 4.0:1, the obtained olefin-based thermoplastic
`more than 4.0:1,
`the obtained olefin-based thermoplastic
`elastomer may exhibit a large first normal StreSS difference
`elastomer may exhibit a large first normal stress difference
`(N). As a result, the ratio (N/SS) of the first normal stress
`(N,). As a result, the ratio (N,/SS) of the first normal stress
`difference (N) to the shear stress (SS) is too high, so that
`difference (N,) to the shear stress (SS) is too high, so that
`uneven luster or Weld marks may tend to be caused.
`uneven luster or weld marks may tend to be caused.
`0019. The propylene-based resin used in the present
`[0019] The propylene-based resin used in the present
`invention preferably has a melt flow rate of 10 to 120 g/10
`invention preferably has a melt flow rate of 10 to 120 g/10
`minutes, more preferably 15 to 100 g/10 minutes, when
`minutes, more preferably 15 to 100 g/10 minutes, when
`measured at 230 C. under a load of 21.18 N according to
`measured at 230° C. under a load of 21.18 N according to
`JIS K7210. When the melt flow rate of the propylene-based
`JIS K7210. When the melt flow rate of the propylene-based
`resin is less than 10 g/10 minutes, the obtained olefin-based
`resin is less than 10 g/10 minutes, the obtained olefin-based
`thermoplastic elastomer may tend to be deteriorated in
`thermoplastic elastomer may tend to be deteriorated in
`moldability. On the other hand, when the melt flow rate of
`moldability. On the other hand, when the melt flow rate of
`the propylene-based resin is more than 120 g/10 minutes, it
`the propylene-based resin is more than 120 g/10 minutes, it
`may become difficult to impart a Sufficient mechanical
`may become difficult
`to impart a sufficient mechanical
`Strength to the obtained olefin-based thermoplastic elas
`strength to the obtained olefin-based thermoplastic elas-
`tomer.
`tomer.
`0020. In the present invention, examples of the olefin
`[0020]
`In the present invention, examples of the olefin-
`based copolymer rubbers as the component (B) contained in
`based copolymer rubbers as the component(B) contained in
`the olefin-based thermoplastic elastomer may include
`the olefin-based thermoplastic elastomer may include
`copolymers obtained by mutually copolymerizing two or
`copolymers obtained by mutually copolymerizing two or
`more C-olefins having about 2 to about 10 carbon atoms
`more a@-olefins having about 2 to about 10 carbon atoms
`Such as ethylene, propylene, 1-butene, 3-methyl-1-butene,
`such as ethylene, propylene, 1-butene, 3-methyl-1-butene,
`1-pentene, 4-methyl-1-pentene, 1-hexene, 4-methyl-1-hex
`1-pentene, 4-methyl-1-pentene, 1-hexene, 4-methyl-1-hex-
`ene, 1-heptene, 1-octene, 1-decene or the like; or copoly
`ene, 1-heptene, 1-octene, 1-decene or the like; or copoly-
`merS obtained by copolymerizing the above copolymers
`mers obtained by copolymerizing the above copolymers
`with non-conjugated dienes Such as 1,4-hexadiene, 4-me
`with non-conjugated dienes such as 1,4-hexadiene, 4-me-
`thyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 6-methyl-1,5-
`thyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 6-methyl-1,5-
`heptadiene, 1,4-octadiene, 7-methyl-1,6-Octadiene, cyclo
`heptadiene, 1,4-octadiene, 7-methyl-1,6-octadiene, cyclo-
`hexadiene,
`cyclooctadiene,
`dicyclopentadiene,
`hexadiene,
`cyclooctadiene,
`dicyclopentadiene,
`5-methylene-2-norbornene,
`5-ethylidene-2-norbornene,
`5-methylene-2-norbornene,
`5-ethylidene-2-norbornene,
`5-butylidene-2-norbornene, 5-isopropenyl-2-norbornene or
`5-butylidene-2-norborene, 5-isopropenyl-2-norbomene or
`the like. Specific examples of the olefin-based copolymer
`the like. Specific examples of the olefin-based copolymer
`rubbers may include ethylene-propylene copolymers, ethyl
`rubbers may include ethylene-propylene copolymers, ethyl-
`ene-1-butene copolymers, ethylene-1-hexene copolymers,
`ene-1-butene copolymers, ethylene-1-hexene copolymers,
`ethylene-1-octene copolymers, propylene-1-butene copoly
`ethylene-1-octene copolymers, propylene-1-butene copoly-
`mers, ethylene-propylene-1,4-hexadiene copolymers, ethy
`mers, ethylene-propylene-1,4-hexadiene copolymers, ethy-
`olene-propylene-dicyclopentadiene copolymers, ethylene
`olene-propylene-dicyclopentadiene copolymers, ethylene-
`propylene-5-ethylidene-2-norbornene copolymers or the
`propylene-5-ethylidene-2-norbornene copolymers or
`the
`like.
`like.
`0021 Among these olefin-based copolymer rubbers,
`[0021] Among these olefin-based copolymer
`rubbers,
`copolymers of ethylene with the other C-olefin or copoly
`copolymers of ethylene with the other a-olefin or copoly-
`mers of ethylene with the other C-olefin and non-conjugated
`mers of ethylene with the other a-olefin and non-conjugated
`diene are preferred. The content of the C-olefin in the above
`diene are preferred. The content of the a-olefin in the above
`copolymers is preferably 10 to 60% by weight, more pref
`copolymersis preferably 10 to 60% by weight, more pref-
`erably 15 to 55% by weight. When the content of the other
`erably 15 to 55% by weight. When the content of the other
`a-olefin is less than 10% by weight, the obtained olefin
`a-olefin is less than 10% by weight, the obtained olefin-
`based thermoplastic elastomer may tend to be deteriorated in
`based thermoplastic elastomer may tend to be deteriorated in
`mechanical Strength Such as low-temperature impact
`mechanical
`strength such as
`low-temperature
`impact
`strength. On the other hand, the content of the other C-olefin
`strength. On the other hand,the content of the other a-olefin
`
`

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`US 2001/0028932 A1
`US 2001/0028932 Al
`
`Oct. 11, 2001
`Oct. 11, 2001
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`is more than 60% by weight, the obtained olefin-based
`is more than 60% by weight,
`the obtained olefin-based
`thermoplastic elastomer may tend to be deteriorated in
`thermoplastic elastomer may tend to be deteriorated in
`mechanical Strength Such as heat-resistant Stiffness. Mean
`mechanical strength such as heat-resistant stiffness. Mean-
`while, the content of the non-conjugated diene contained in
`while, the content of the non-conjugated diene contained in
`the above olefin-based copolymers which are further copo
`the above olefin-based copolymers which are further copo-
`lymerized with the non-conjugated diene, is preferably 0.5
`lymerized with the non-conjugated diene, is preferably 0.5
`to 20% by weight, more preferably 1 to 15% by weight.
`to 20% by weight, more preferably 1 to 15% by weight.
`0022. The olefin-based copolymer rubber used in the
`[0022] The olefin-based copolymer rubber used in the
`present invention may also be produced by any copolymer
`present invention mayalso be produced by any copolymer-
`ization method using either Ziegler catalysts Such as Vana
`ization method using either Ziegler catalysts such as vana-
`dium compounds or metallocene catalysts.
`dium compoundsor metallocene catalysts.
`0023 The olefin-based copolymer rubber used in the
`[0023] The olefin-based copolymer rubber used in the
`present invention has a melt flow rate of preferably 0.1 to 20
`present invention has a melt flow rate of preferably 0.1 to 20
`g/10 minutes, more preferably 0.2 to 15 g/10 minutes, when
`g/10 minutes, more preferably 0.2 to 15 g/10 minutes, when
`measured at 230 C. under a load of 21.18 N according to
`measured at 230° C. under a load of 21.18 N according to
`JIS K7210. When the melt flow rate of the olefin-based
`JIS K7210. When the melt flow rate of the olefin-based
`copolymer rubber is less than 0.1 g/10 minutes, the obtained
`copolymerrubberis less than 0.1 g/10 minutes, the obtained
`olefin-based thermoplastic elastomer may tend to be dete
`olefin-based thermoplastic elastomer may tend to be dete-
`riorated in moldability. On the other hand, the melt flow rate
`riorated in moldability. On the other hand, the melt flow rate
`of the olefin-based copolymer rubber is more than 20 g/10
`of the olefin-based copolymer rubber is more than 20 g/10
`minutes, it may become difficult to impart a Sufficient
`minutes,
`it may become difficult
`to impart a sufficient
`mechanical Strength to the obtained olefin-based thermo
`mechanical strength to the obtained olefin-based thermo-
`plastic elastomer.
`plastic elastomer.
`0024. The olefin-based thermoplastic elastomer of the
`[0024] The olefin-based thermoplastic elastomer of the
`present invention contains preferably 30 to 70% by weight
`present invention contains preferably 30 to 70% by weight
`of the propylene-based resin as the component (A) and 70 to
`of the propylene-based resin as the component(A) and 70 to
`30% by weight of the olefin-based copolymer rubber as the
`30% by weightof the olefin-based copolymer rubberas the
`component (B), more preferably 35 to 60% by weight of the
`component (B), more preferably 35 to 60% by weight ofthe
`component (A) and 65 to 40% by weight of the component
`component (A) and 65 to 40% by weight of the component
`(B). When the content of the component (A) is less than 30%
`(B). When the content of the component(A)is less than 30%
`by weight and the content of the component (B) is more than
`by weight and the content of the component (B) is more than
`70% by weight, the obtained olefin-based thermoplastic
`70% by weight,
`the obtained olefin-based thermoplastic
`elastomer may tend to be deteriorated in mechanical Strength
`elastomer maytendto be deteriorated in mechanical strength
`Such as heat-resistant Stiffne