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
1998-11-05
2001-06-05
Yoon, Tae H. (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, C524S534000, C525S263000, C525S313000, C525S331700, C428S035700
Reexamination Certificate
active
06242525
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to thermoplastic elastomers of high strength and elasticity and of good dyeability and polymer blends of high impact strength produced therefrom, which are suitable for use in the vehicle industry, in the domestic appliances industry and in medical technology. The invention also relates to a method for producing these thermoplastic elastomers.
Thermoplastic elastomers, such as styrene-butadiene block copolymers, thermoplastic polyurethanes, polyester amides, polyether amides, thermoplastic copolyester elastomers and polyolefin alloys with elastomers are known (Rader, C., Kunststoffe 83 (1993) 10, 777-781; Kunststoffe 86 (1996)
12, 1845-1851).
The special advantage of polyolefin alloys with elastomers as thermoplastic elastomers lies in the easy processability and the advantageous recycling properties of these products.
The material properties of thermoplastic elastomers based on polyolefin alloys with elastomers, such as strength and elasticity, are determined by the composition of the polyolefin component and the elastomeric component and the distribution of the elastomeric component in the polyolefin component (Moore, P., Polypropylene Handbook, Carl Hanser-Verlag, Munich 1996, 218-225).
Known elastomeric components for thermoplastic elastomers based on polypropylene are ethylene-propylene elastomers (EP 672 712; EP 614940), ethylene-propylene-diene elastomers (EP 547 843; EP 409542), ethylene-vinyl acetate copolymers (BE 899507; Coran, A., Rubber Chem. Technol. 54 (1981), 892), chlorosulfinated polyethylene (U.S. Pat. No. 4,141,878), elastomeric copolymers of ethylene and C
4
-C
8
olefins, such as elastomeric ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers (Yamaguchi, M., J. Appl. Polymer Sci. 62 (1996), 87-97; 63 (1997), 467-474; Yu, T., J. Plastic Film & Sheeting 10 (1994) 1, 539-564), as well as elastomeric, atactic polypropylenes (EP 334 829) in amounts of 35 to 70% by weight, based on the polyolefin mixture.
Furthermore, the vulcanization of elastomeric components in polyolefin alloys based on polypropylene/ethylene-propylene-diene elastomers, by the addition of dodecyl mercaptan (DE 26 20 820), sulfur (EP 336780) or tetrabutylthiuram disulfide (EP 376 213) is known. However, these formulations have the disadvantage of a strong discoloration, so that semi-finished products and molded objects of these materials can be used only when dyed black.
Furthermore, for the preparation of thermoplastic elastomers by compounding polypropylene with ethylene-propylene-diene elastomers, the use of thermally decomposing free radical-forming agents, such as azo compounds (U.S. Pat. No. 5,079,283) or peroxides (U.S. Pat. No. 5,459,201; Kim, Y., Polymer Engn. Sci. 35 (1995) 20, 1592-1594; BE 841507) or of thermally decomposing free radical-forming agents in combination with divinyl compounds, such as divinylpyridine (J 88 067 802) or divinylbenzene (U.S. Pat. No. 4,912,148, EP 311451), is also known.
For formulations of polypropylenes and elastomeric ethylene-hexene copolymers, the modification of the blends by electron irradiation is known (JP 96 301 927).
Thermoplastic elastomers are also known as ternary blends of polyethylenes, polypropylenes and ethylene-propylene-diene elastomers (EP 699522; Kim, J. Applied Polymer Sci. 60 (1996), 2199-2206).
Thermoplastic elastomers of good dyeability and high elasticity can be achieved by means of these formulations. However, high strength requirements are not fulfilled.
Impact-resistant polymer blends of polyolefins and elastomers are known. Known impact-resistant components for polypropylene are amorphous ethylene-propylene-diene elastomers (Michaeli, W., Kunststoffberater (1990) 3, 38-43; Kloos, F., Angewandte Makromelekulare Chemie 185/186 (1991), 97-108), ethylene-propylene elastomers (Kim, B., J. Applied Polymer Sci. 60 (1996), 2207-2218, J. Applied Polymer Sci. 60 (1996), 1391-1403), also in the form of reactor blends of polypropylene and ethylene-propylene rubber (Kresge, E., Macromol. Symp. 53 (1992), 173-189, Schwager, H., Kunststoffe 82 (1992) 6, 499-501), butadiene-&agr;-methylstyrene rubber (Natov, M., Plaste u. Kautschuk 38 (1991) 3, 85-88), styrene-butadiene block copolymers (Karger-Kocsis, J., Kunststoffe 74 (1984), 104-107), elastomeric copolymers of ethylene and higher molecular weight C
4
-C
8
olefins (Yu, T., ANTEC 94, 2439-2441; Meiske, L., ANTEC 96, 2001-2005) and elastomeric ethylene-vinyl acetate copolymers (Gupta, A., J. Applied Polymer Sci. 45 (1992), 1303-1312) in amounts of 10 to 35% by weight, based on the polyolefin mixture.
The limited compatibility of the impact-resistant components is a disadvantage of these unmodified blends.
DETAILED DESCRIPTION OF THE INVENTION
The object of the present invention was the development of thermoplastic elastomers, which at the same time have a high strength, a high elasticity and good dyeability, as well as the high impact-resistant polymer blends produced therefrom.
Surprisingly, it was found that, by compounding propylene homopolymers and/or propylene copolymers with elastomers with addition of readily volatile C
4
to C
7
dienes, optionally in the presence of thermally decomposing free radical-forming agents, thermoplastic elastomers with a very finely dispersed distribution of elastomeric components in the polyolefin component are formed and fulfill these requirements.
The object of the invention was accomplished by thermoplastic elastomers of high strength, high elasticity and good dyeability, the incorporated elastomeric particles of which have an average particle diameter of 0.05 to 5 &mgr;m and preferably of 0.1 to 1 &mgr;m, of propylene homopolymers and/or propylene copolymers, elastomeric C
2
to C
8
olefin copolymers and/or terpolymers, multifunctional, unsaturated monomers, optionally thermally decomposing free radical-forming agents and auxiliary materials, the thermoplastic elastomers being produced by a method, for which mixtures of 20 to 80% by weight and preferably of 40 to 60% by weight of propylene homopolymers and/or propylene copolymers, 80 to 20% by weight and preferably 60 to 40% by weight of elastomeric C
2
to C
8
olefin copolymers and/or terpolymers, 0.10 to 4.0% by weight and preferably 0.2 to 1.5% by weight, based on the total of the polymers used, of readily volatile C
4
to C
7
dienes and 0 to 4.0% by weight and preferably 0.2 to 1.5% by weight, based on the total of the polymers used, of acyl peroxides, alkyl peroxides, hydroperoxides, peroxycarbonates, peresters, ketone peroxides, peroxyketals and/or azo compounds as thermally decomposing free radical-forming agents are reacted in the melt and, before and/or after the reaction, 0.01 to 40% by weight, based on the total of the polymers used, of auxiliary materials being possibly added.
The finely dispersed distribution of the elastomeric components in the polyolefin component, which lies in the &mgr;m range in the case of the inventive thermoplastic elastomers, can be determined by transmission electron microscopic photographs.
Pursuant to the invention, the propylene homopolymers preferably are largely isotactic propylene homopolymers, especially isotactic propylene homopolymers, which were synthesized using Ziegler-Natta catalysts or metallocene catalysts. Especially suitable in this connection are propylene homopolymers with a bimodal distribution of molecular weights, weight average molecular weights M
w
of 500,000 to 1,500,000 g/mole, number average molecular weights M
n
of 25,000 to 100,000 g/mole and M
w
/M
n
values of 5 to 60, which were synthesized in a reactor cascade.
Copolymers of propylene and &agr;-olefins with 2 or 4 to 18 carbon atoms, especially random propylene copolymers, propylene block copolymers and/or random propylene block copolymers are also preferred for the inventive thermoplastic elastomers.
Mixtures of 50 to 98% by weight of largely isotactic propylene homopolymers and/or copolymers of propylene and ol-olefins with 2 or 4 to 18 carbon atoms and 2 to 50% by weight of non-isota
Bucka Hartmut
Heinemann Hermann
Hesse Achim
Radusch Hans-Joachim
Raetzsch Manfred
Borealis GmbH
Jordan and Hamburg LLP
Yoon Tae H.
LandOfFree
Thermoplastic elastomers of high strength and elasticity and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermoplastic elastomers of high strength and elasticity and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoplastic elastomers of high strength and elasticity and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2491875