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
1998-05-06
2001-06-19
Niland, Patrick D. (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...
C524S261000, C524S474000, C524S476000, C524S484000, C524S485000, C524S486000, C524S491000, C524S504000, C525S074000, C525S078000
Reexamination Certificate
active
06248825
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the production of polyalkylene grafted poly(alkenyl benzene-co-maleimide) polymers and to the use of such polymers when oil extended in producing high damping, soft materials.
BACKGROUND OF THE INVENTION
The polymerization of styrene and maleic anhydride by free radical initiation is well known in the prior art. Similarly, poly(styrene-co-maleic anhydride) polymer is well known. Further, imidization between a maleic anhydride and a primary amine group is a commonly known chemical reaction. Patent publications which have recognized these reactions include: German Patent DE 4241538, assigned to Leuna-Werke A.-G; Japanese Patent JP 94248017, assigned to Monsanto Kasel Kk.; and, Italian Patent EP 322905 A2, assigned to Montedipe S.p.A. Various other non-patent publications have also recognized these reactions. Included among them are: L. E. Colleman, Jr., J. F. Bork, and H. Donn, Jr., J. Org. Chem., 24, 185(1959); A. Matsumoto, Y. Oki, and T. Otsu, Polymer J., 23 (3), 201(1991); L. Haeussler, U. Wienhold, V. Albricht, and S. Zschoche, Themochim. Acta, 277, 14(1966); W. Kim, and K. Seo, Macromol. Rapid Commun., 17, 835(1996); W. Lee, and G. Hwong, J. Appl. Polym. Sci., 59, 599(1996); and, I. Vermeesch and G. Groeninckx, J. Appl. Polym. Sci., 53, 1356(1994).
The synthesis of monofunctional N-alkyl and N-aryl maleimides are also well known in the prior art. They have been extensively used to improve the heat stability of homo- and especially copolymers prepared from vinyl monomers. Typically, the bulk resins comprise ABS (poly(acrylonitrile-co-butadiene-co-styrene)) or a polyblend of poly(acrylonitrile-co-butadiene) and poly(styrene-co-acrylonitrile); PVC (poly(vinyl chloride)); SAN (poly(styrene-co-acrylonitrile)); PMMA (poly-(methyl methacrylate)); and the like. The maleimides can be copolymerized with other monomers such as acrylonitrile, butadiene, styrene, methyl methacrylate, vinyl chloride, vinyl acetate and many other comonomers. A more preferred practice in the industry is to produce copolymers of maleimides with other monomers such as styrene and optionally acrylonitrile and to blend these with ABS and SAN resins. In any event, the polymer compositions are adjusted so that the copolymers are fully compatible with the bulk resins (e.g., ABS and/or SAN) as shown by the presence of a single glass transition point (T(g)) as determined by differential scanning calorimetry (DSC).
It has long been recognized that two or more polymers may be blended together to form a wide variety of random or structured morphologies to obtain products that potentially offer desirable combinations of characteristics. However, it may be difficult or even impossible in practice to achieve many potential combinations through simple blending because of some inherent and fundamental problem. Frequently, the two polymers are thermodynamically immiscible, which precludes generating a truly homogeneous product. This immiscibility may not be a problem since often it is desirable to have a two-phase structure. However, the situation at the interface between these two phases very often does lead to problems. The typical case is one of high interfacial tension and poor adhesion between the two phases. This interfacial tension contributes, along with high viscosities, to the inherent difficulty of imparting the desired degree of dispersion to random mixtures and to their subsequent lack of stability, giving rise to gross separation or stratification during later processing or use. Poor adhesion leads, in part, to the very weak and brittle mechanical behavior often observed in dispersed blends and may render some highly structured morphologies impossible.
It is particularly desirable to prepare a grafted copolymer having the impact strength of polypropylene and the elastomeric properties of a block copolymer. It is also desireable to add an extender or plasticizer to the resultant grafted copolymer in order to obtain a copolymer having a low Shore A hardness.
OBJECTS OF THE INVENTION
Accordingly, it is an object of this invention to provide an oil or low molecular weight component extended grafted “centipede” polymer of a maleated polypropylene and a poly(alkenyl benzene-co-maleimide) that is useful in producing high damping and soft materials.
More specifically, it is an object of this invention to provide a grafted centipede polymer formed by reacting maleated polypropylene and a poly(alkenyl benzene-co-maleimide) with a diamine.
Another object of the invention is to provide oil or low molecular weight component extended grafted centipede polymers that exhibit improved properties, including low Shore A hardness less than 35, high damping properties and a service temperature of about 100° C.
SUMMARY OF THE INVENTION
The present invention is directed to an oil or low molecular weight component extended grafted poly(alkenyl benzene-co-maleimide)-polypropylene polymer soft gel composition having damping properties useful in producing molded products having heat resistance and a high elasticity and damping property.
The present invention is broadly directed to grafted polymer compositions of a maleated polypropylene and a poly(alkenyl benzene-co-maleimide) reacted with a diamine. It is further directed to a process for preparing an oil extended grafted polymer compositions broadly comprising a maleated polypropylene grafted to a functionalized thermoplastic material, namely a poly(alkenyl benzene-co-maleimide), under conditions sufficient to permit grafting of the functionalized polypropylene with the functionalized thermoplastic material. The grafted polymer is a glass-like material that becomes a soft and rubber-like elastomer after being oil-extended.
DETAILED DESCRIPTION OF THE INVENTION
The extended grafted polymer gels of the present invention contain: 100 parts by weight of a grafted polymer of a poly(alkenyl benzene-co-maleimide) having at least one maleated polypropylene segments grafted thereto through the at least one functional linkage formed by a crosslinking reaction with a diamine grafting agent; and at least 30, preferably 30 to 1000, parts by weight of an extender such as an oil or a low molecular weight component.
The poly(alkenyl benzene-co-maleimide) is a “centipede” polymer formed by imidizing a poly(alkenyl benzene-co-maleic anhydride) with a primary amine. The “centipede” polymer has a high molecular weight spine connected with many relatively short side chains formed from the addition of the primary amines. The length of the main chain usually equals or is longer than the entanglement length, which is herein defined theoretically as an order of magnitude of 100 repeating units, while the length of the side chains is much smaller than the entanglement length.
The preferred alkenyl benzenes contributed monomer units of the poly(alkenyl benzene-co-maleimide) “centipede” polymer are either styrene or alpha-methylstyrene. The terms “alkenyl benzene” and “vinyl aromatic” are understood to be interchangeable as used herein.
The poly(alkenyl benzene-co-maleimide) described herein are subsequently graft-reacted through a difunctional linking or grafting agent to a maleated polypropylene to yield a grafted polymer having at least one polypropylene segment grafted thereto through the at least one functional linkages thus formed.
The maleated polypropylene may be any of the conventionally known polypropylene compounds that are subsequently maleated by methods known in the art. The polypropylene grafted segment or segments have molecular weights “M
w
” of about 10,000 up to about 10,000,000, or higher, preferably about 20,000 to about 300,000.
The crystallinity, or tacticity, of the polypropylene may vary from being substantially amorphous to being completely crystalline, that is from about 10-100% crystallinity. Most typically, because of the extensive commercial use of isotactic polypropylene, the grafted polypropylene will be substantially crystalline, e.g., greater than about 90%. Generally, the polypropylene is substantially free of ethylene. However
Foltz Victor J.
Mashita Naruhiko
Matsuse Takahiro
Toyosawa Shinichi
Wang Xiaorong
Bridgestone Corporation
Burleson David G.
McCollister Scott A.
Niland Patrick D.
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