Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-11-08
2003-10-21
Shosho, Callie (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S526000, C525S240000, C526S943000
Reexamination Certificate
active
06635705
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an olefinic thermoplastic elastomer composition, more particularly to an olefinic thermoplastic elastomer composition that can provide a molded product excellent in tensile strength and tensile elongation at break and the like and to a method for producing the same.
An olefinic thermoplastic elastomer composition, being light and easy to be recycled, is widely used for automobile parts, industrial machine parts, electronic/electric instrument parts, construction materials and the like as an energy-saving and resources-saving thermoplastic elastomer particularly in place of a vulcanized rubber.
The conventional olefinic thermoplastic elastomer, however, has the defect that it has poorer tensile strength and tensile elongation at break compared to a vulcanized rubber, and improving the defect has been desired strongly.
As one of the olefinic thermoplastic elastomers having these characteristics improved, there has been proposed a thermoplastic elastomer comprising an ethylene-&agr;-olefin-non-conjugated polyene copolymer polymerized by using a metallocene catalyst. (JP-A-9-012790)
However, although such a thermoplastic elastomer possesses improved tensile strength, tensile elongation at break and compression set compared to the conventional thermoplastic elastomer, the characteristics are still inferior to those of the vulcanized rubber, and a further improvement has been desired.
The inventors found, as a result of the study to solve the foregoing problem, that a thermoplastic elastomer which was further enhanced in tensile strength and tensile elongation at break could be obtained by using a specified rubber in a specified proportion.
Moreover, the inventors found that a thermoplastic elastomer further excellent in tensile strength, tensile elongation at break and compression set could be obtained by dynamically heat treating a crystalline polyolefin resin and an ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber under specified conditions in the presence of a crosslinking agent, thus accomplishing the present invention.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention is to solve the problem of the prior art technology as mentioned above and to provide a thermoplastic elastomer composition superior in the characteristics of tensile strength, tensile elongation at break and the like.
The present invention includes the following inventions.
(i) An olefinic thermoplastic elastomer composition comprising 10 to 60 wt. parts of a crystalline polyolefin resin (A), 88 to 38 wt. parts of an ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) consisting of ethylene, an &agr;-olefin having 3 to 20 carbon atoms and a non-conjugated polyene and 2 to 30 wt. parts of at least one rubber (C) selected from polyisobutylene, butyl rubber and a propylene-ethylene copolymer rubber having a propylene content of 50 mol % or more,(the total of (A), (B) and (C) being 100 wt. parts), said ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) being a crosslinked thermoplastic elastomer composition, said ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) being obtained by random copolymerization of ethylene, an &agr;-olefin of 3 to 20 carbon atoms and a non-conjugated polyene in the presence of a metallocene catalyst, (1) containing the unit (a) derived from the ethylene and the unit (b) derived from the &agr;-olefin of 3 to 20 carbon atoms in a molar ratio of 40/60 to 95/5 [(a)/(b)], (2) having an iodine value of 1 to 50, and (3) having an intrinsic viscosity [&eegr;] measured in decalin at 135° C. of 1.0 to 10 dl/g.
(ii) An olefinic thermoplastic elastomer composition comprising 10 to 60 wt. parts of a crystalline polyolefin resin (A), 88 to 38 wt. parts of an ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) consisting of ethylene, an &agr;-olefin having 3 to 20 carbon atoms and a non-conjugated polyene and 2 to 40 wt. parts of an ethylene-&agr;-olefin copolymer (D) having a density of 0.870 to 0.940 (g/cm
3
) and an ethylene content of 85 mol % or more (the total of (A), (B) and (D) being 100 wt. parts), said ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) being a crosslinked thermoplastic elastomer composition, said ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) being obtained by random copolymerization of ethylene, an &agr;-olefin of 3 to 20 carbon atoms and a non-conjugated polyene in the presence of a metallocene catalyst, (1) containing the unit (a) derived from the ethylene and the unit (b) derived from the &agr;-olefin of 3 to 20 carbon atoms in a molar ratio of 40/60 to 95/5 [(a)/(b)], (2) having an iodine value of 1 to 50, and (3) having an intrinsic viscosity [&eegr;] measured in decalin at 135° C. of 1.0 to 10 dl/g.
(iii) A thermoplastic elastomer composition according to said (i) or (ii), wherein said ethylene-&agr;-olefin-non-conjugated polyene copolymer has (4) a [g&eegr;*(=[&eegr;]/[&eegr;]
blank
)] of 0.2 to 0.95 which is a ratio of the intrinsic viscosity [&eegr;] measured as above-mentioned (3) to the intrinsic viscosity [&eegr;]
blank
measured in decalin at 135° C. for a linear ethylene-propylene copolymer having an ethylene content of 70 mol % and having the same weight average molecular weight (by light scattering method) as the ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber having that intrinsic viscosity [&eegr;].
(iv) A thermoplastic elastomer composition according to said (iii), wherein said ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) has (5) an intensity ratio D(T&agr;&bgr;/T&agr;&agr;) (a ratio of T&agr;&bgr; to T&agr;&agr; in
13
C-NMR spectrum) of 0.5 or less, has (6) a B value of 1.00 to 1.50 which is obtained from
13
C-NMR spectrum and the following formula,
B
value=[
P
OE
]/(2·
[P
E
]·[P
O
])
wherein, [P
E
] being a molar fraction of the unit (a) derived form ethylene in the random copolymer rubber, [P
O
] being a molar fraction of the unit (b) derived from &agr;-olefin in the random copolymer rubber, and [P
OE
] being a ratio of the &agr;-olefin/ethylene chain number to the total dyad chain number in the random copolymer rubber,
and has (7) a glass transition temperature (Tg) obtained by DSC of −50° C. or lower.
(v) A thermoplastic elastomer composition according to any of said (i) to (iv) which is produced by dynamic heat treatment according to the conditions shown in the following formula,
5.5<2.2
logX+logY−logZ
+(
T−
180)÷100<6.5
(wherein T is a resin temperature (° C.) at the die exit of extruder, X is a screw diameter (mm) of extruder, Y is a maximum shear rate (sec
−1
) generated in extruder and Z is an extrusion amount (kg/h.).
(vi) A thermoplastic elastomer composition according to said (v) which is produced by dynamic heat treatment in the presence of a crosslinking agent.
(vii) A thermoplastic elastomer composition according to said (vi), wherein said crosslinking agent is an organic peroxide.
(viii) A thermoplastic elastomer composition according to any of said (i) to (vii) which contains 2 to 100 wt. parts of a softening agent (E) and/or 2 to 100 wt. parts of an inorganic filler (F) to the total 100 wt. parts of said crystalline polyolefin resin (A), ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B), and at least one rubber (C) selected from polyisobutylene, butyl rubber and a propylene-ethylene copolymer rubber having a propylene content of 50 mol % or more or an ethylene-&agr;-olefin copolymer (D) having a density of 0.870 to 0.940 (g/cm
3
) and an ethylene content of 85 mol % or more.
(ix) A method for producing an olefinic thermoplastic elastomer composition characterized by dynamically heat treating, in the presence of a crosslinking agent under the below-mentioned conditions, 10 to 60 wt. parts of a cr
Itoh Yuichi
Kawasaki Masaaki
Kobayashi Kyoko
Uchiyama Akira
Mitsui Chemicals Inc.
Shosho Callie
LandOfFree
Olefinic thermoplastic elastomer composition and method for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Olefinic thermoplastic elastomer composition and method for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Olefinic thermoplastic elastomer composition and method for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3116788