Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1996-11-13
1998-05-12
Buttner, David
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525 71, 525 89, 525 90, 525 91, 525 92D, 525 94, C08L 7112, C08L 5302, C08L 5300
Patent
active
057506213
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to multiphase polymer blends containing B and and is incompatible with the polymer (A), (A) is compatible with the block A and incompatible with the block C, the polymer (D) is compatible with the block C and incompatible with the block A, the resilient block B has a glass transition temperature below +20.degree. C. and the blocks A, B and C are incompatible with one another.
The present invention furthermore relates to the use of these molding materials for the production of moldings of any type and to the moldings produced therefrom.
Polymer blends serve in general for combining two different polymers having the desirable properties of the individual components, the undesirable properties as far as possible being compensated. This makes it possible to open up different applications with novel blend compositions.
However, macromolecular substances have a pronounced disinclination to mix with other polymers, so that blend compositions generally contain a compatibilizer.
Many problems in the preparation of polymer blends comprising a plurality of polymers which are incompatible with one another arise as a result of insufficient phase binding, ie. adhesion between the individual polymer phases. In order to achieve better phase binding, block or graft copolymers are frequently added to the components of the blend. In the polymer blends known to date, however, the phase binding is still not completely satisfactory. Moreover, the formation of voids at the boundaries of the individual polymer phases is observed during the processing of said blends and is due to the different coefficients of thermal expansion of the polymer phases. This has an adverse effect on the mechanical strength, in particular the toughness and the stress cracking resistance of the resulting polymer blends.
Furthermore, in the preparation of polymer blends it is frequently difficult to mix different polymers with one another in a suitable manner, since some important polymers, for example polyphenylene ethers (PPE), are only poorly compatible with other polymers. In such cases, a compatibilizer which is intended to improve the miscibility of two polymers exhibiting little compatibility is frequently used. In this context, JP-A 01/054 052 discloses, inter alia, the use of a copolymer of styrene and acrylonitrile and/or methacrylate for PPE/ABS blends. However, the blends obtained have unsatisfactory toughness and insufficient stress cracking resistance and joint line strength.
In the more recent document WO 93/03291, A--B--C three-block copolymers were proposed as compatibilizers for incompatible polymers.
It is an object of the present invention to provide multiphase polymer blends, in particular comprising poorly miscible polymers, which, as a result of a compatibilizer, give good blend compositions having good phase binding with a very large number of polymers. Said blends should have good heat distortion resistance in combination with very good toughness (in particular multiaxial impact strength) as well as stress cracking resistance and joint line strength.
We have found that this object is achieved by the multiphase polymer blends defined at the outset.
Preferred blends of this type and their use are described in the subclaims.
The novel polymer blends contain, in addition to a polymer (A), two two-block copolymers (B) and (C) which consist of a block A, a resilient block B having a glass transition temperature below +20.degree. C., in particular below 0.degree. C., and a block C, which differ from one another. Preferred multiphase polymer blends have a resilient block B of this type which is composed of a polymer of a conjugated diene. The novel polymer blends also contain at least one further polymer (D) which differs from (A), (B) and (C) and is incompatible with the polymer (A). Also important here is the fact that the polymer (A) is compatible with the block A and incompatible with the block C and the polymer (D) is compatible with the block C and incompatible with the block A and the blocks A, B and
REFERENCES:
patent: 3833687 (1974-09-01), Lee
patent: 4258144 (1981-03-01), Childers
patent: 4366289 (1982-12-01), Keskkula
patent: 4716199 (1987-12-01), van der Meer
patent: 5091473 (1992-02-01), Arashiro
Ren "Hydrogenated Polybutadiene-Polymethyl Methacrylate Block Polymer" Journal of Polymer Science Part A 31(4); 1993 pp. 847-851.
Fayt "Molecular Design of Multicomponent Polymer Systems"Macromolecules 19(7); 1986 pp. 2077-2080.
Chemical Abstract 95:133837 (of JP56050958).
Won Ho Jo et al., Macromolecules, 1991, vol. 24, pp. 2231-2235.
Gottschalk Axel
Krappe Udo
Stadler Raimund
BASF - Aktiengesellschaft
Buttner David
LandOfFree
Multiphase polymer blends does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiphase polymer blends, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiphase polymer blends will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-979818