Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1989-08-18
1991-10-08
Marquis, Melvyn I.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525 93, 525 95, 525 98, C08G 6391, C08L 5300, C08L 5302, C08L 906
Patent
active
050555197
DESCRIPTION:
BRIEF SUMMARY
The invention relates to thermoplastic elastomer compositions, to a process for the preparation thereof and to articles comprising such compositions.
Very well-known block copolymers of an aromatic vinyl compound and a conjugated diene compound are styrene-butadiene block copolymers. They are produced industrially and are used as raw materials for shoe soles and as thermoplastic elastomers for improving the quality of polystyrene.
The preparation of the afore-mentioned block copolymers of an aromatic vinyl compound and a conjugated diene compound by anionic polymerization is well-known, but since they are prepared from an aromatic vinyl compound and a conjugated diene compound, they easily take up oil and wax. They are known therefore to swell on contact with oil and wax, and thus to loose mechanical strength and become fragile.
Therefore, thermoplastic elastomers made of the above mentioned block copolymers are required which may be put to a greater variety of uses and whose elasticity and bending resistance performances are enhanced.
As a method of enhancing the elasticity of the thermoplastic elastomer, there is the method of adding process oil to the thermoplastic elastomer. However, by this method the properties of the product, e.g. its mechanical strength, such as its tensile strength, will decrease and there will occur bleed.
Another method to enhance the elasticity is the addition of a rubber substance, but as the thermoplastic elastomer and the rubber substance do not blend sufficiently, here too there is the problem of reduced mechanical strength, such as its tensile strength.
As a method of enhancing the oil resistance it is known to mix for instance the excellently oil-resistant acrylonitrile-butadiene copolymer with the styrene-butadiene copolymer, but since these two copolymers have different solubilities in each other, the two copolymers will separate when they are simply mixed, which will lead to a thermoplastic elastomer of very poor mechanical strength.
The present invention offers themoplastic elastomer compositions having excellent elasticity, bend resistance and mechanical strength as well as excellent oil resistance owing to the blending in of a special rubber polymer.
Accordingly, the invention provides thermoplastic elastomer compositions characterized in that they have been prepared from the following components: conjugated diene compound and/or a selectively hydrogenated product thereof, reactive with the functional group of component (C), and from carboxyl, amino, epoxy and hydroxyl groups.
In the composition according to the present invention, an aromatic vinyl polymer containing a reactive functional group (component B) is introduced in order to improve the mutual solubilities of the aromatic vinyl-conjugated diene block copolymer and/or the selectively hydrogenated product thereof (component A) and the rubber polymer (component C), whose solubilities are different, and thus chemical linkage of the rubber polymer (component C) and the aromatic vinyl polymer (component B) is brought about. As the mutual solubilities of the polystyrene block of block copolymer (component A) and of the aromatic vinyl polymer (component B) is good, the aromatic vinyl polymer having a reactive functional group (component B) becomes the mutual solubilizer of component A and component C, and the three kinds of polymer (component A), (component B) and (component C) can become mutually soluble.
The aromatic vinyl-conjugated diene block copolymer or the selectively hydrogenated product thereof (component A) may be represented by the following formula aromatic vinyl compound polymer, B the conjugated diene polymer or copolymer or the hydrogenated polymer product of the conjugated diene (co) polymer and C a residue of a coupling agent.
The amount of aromatic vinyl compound present in the afore-mentioned block copolymer is suitably in range of from 7 to 90% by weight, preferably 10 to 70% by weight, its molecular weight suitably in the range of from 30,000 to 1,000,000, preferably 50,000 to 500,000.
The aro
REFERENCES:
patent: 3907929 (1975-09-01), Durst
patent: 4315086 (1982-02-01), Veno et al.
patent: 4524184 (1985-06-01), Murray
patent: 4590241 (1986-05-01), Hohlfeld
patent: 4902749 (1990-02-01), Akkapeddi et al.
Ieki Yasuo
Miyachi Takumi
Nagano Masanobu
Ono Hisao
Clark W. R. H.
Marquis Melvyn I.
Shell Internationale Research Maatschappij B.V.
LandOfFree
Thermoplastic elastomer compositions and process for the prepara 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 elastomer compositions and process for the prepara, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoplastic elastomer compositions and process for the prepara will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-257569