Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
1994-08-18
2001-07-10
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S240000, C526S259000, C526S265000, C526S287000, C526S328000
Reexamination Certificate
active
06258911
ABSTRACT:
CROSS REFERENCE TO COPENDING APPLICATIONS AND RELATED PATENTS
Attention is directed to commonly owned and assigned U.S. Pat. No. 5,322,912, issued Jun. 21, 1994, entitled, “POLYMERIZATION PROCESSES AND THEIR TONER COMPOSITIONS THEREFROM”, wherein there is illustrated a free radical polymerization process for the preparation of a thermoplastic resin or resins comprising, in embodiments, heating a mixture of a free radical initiator, a stable free radical agent, and at least one polymerizable monomer compound to form a thermoplastic resin or resins with a high monomer to polymer conversion; cooling the mixture; isolating the thermoplastic resin or resins; and washing and drying said thermoplastic resin or resins. In other embodiments there are disclosed processes for forming diblock, multiblock, monomodal, and multimodal thermoplastic resin products by variations in, for example, the order and or amounts of added reactants and free radical compounds. U.S. Pat. No. 5,312,704, issued May 17, 1994, entitled “MONOMODAL, MONODISPERSED TONER COMPOSITIONS AND IMAGING PROCESSES”, wherein there is illustrated a toner composition comprised of pigment particles, and a resin comprised of a monomodal polymer resin or monomodal polymer resin blends and wherein the monomodal resin or resin blends possess a narrow polydispersity.
Also, attention is directed to commonly owned and assigned copending applications application Numbers, U.S. Ser. No. 08/181,134, filed Jan. 4, 1994; U.S. Ser. No. 08/307,192, filed Mar. 25, 1993; continuation-in-part of U.S. Pat. No. 5,332,912, filed Nov. 16, 1992, U.S. Ser. No. 08/214,518, filed Mar. 18, 1994, entitled “EMULSION POLYMERIZATION PROCESSES AND TONER COMPOSITIONS THEREFROM”; U.S. Ser. No. 08/223,418, filed Apr. 4, 1994, entitled “AQUEOUS POLYMERIZATION PROCESSES”; and U.S. Ser. No. 08/242,490, filed May 13, 1994, entitled “ACRYLATE POLYMERIZATIONS”.
The disclosures of the above mentioned patents and copending applications are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to polymers, toner compositions, processes for the preparation of polymers, especially telechelic polymers, and more specifically to free radical polymerization processes which provide telechelic or bifunctionalized polymeric products having narrow polydispersity properties. In embodiments, the present invention relates to the utilization of free radical initiators together with free radical reactive monomer compounds and stable free radical agents, such as those illustrated in U.S. Pat. No. 5,332,912, the disclosure of which is totally incorporated herein by reference, to enable the preparation of bifunctional macromolecules which can be selected for crosslinking and permitting the formation of triblock and multiblock copolymers. More specifically in embodiments the present invention relates to providing novel narrow molecular weight pseudoliving homopolymers and copolymer resins that possess latent reactive sites at both ends thereof and wherein, for example, at elevated temperature the aforementioned resins can be reacted with other polymers having a free radical reactive site causing the modification thereof. This reaction can introduce crosslinking in the other polymer or polymers. The reaction of the bifunctional macromolecules with other monomers enables the formation of multiblock copolymers. The products obtained such as the multiblock copolymers can be selected as dispersants, viscosity modifiers, compatibilizers especially for toners with wax, and as polymers for toner compositions. The products obtained with the processes illustrated herein can in embodiments possess narrow polydispersities, that is, narrow molecular weight distributions as defined by the ratio M
w
:M
n
, wherein M
w
is the weight average molecular weight and M
n
is the number average molecular weight.
In other embodiments of the present invention are provided processes for the preparation of bifunctional pseudoliving polymeric compounds or bifunctional compounds derived from the addition of stable free radicals to the product resulting from the free radical addition of at least one monomer to a bifunctional free radical initiator compound; processes for further chemical elaboration and modification of the, bifunctional polymer compounds; and processes for the chemical preparation and subsequent elaboration of the bifunctional polymer compounds and derivatives thereof. The polymeric bifunctional compounds of the present invention can be used to prepare, for example, triblock copolymers and multiblock polymer having narrow polydispersity properties and optionally wherein at least one of the blocks is water soluble and subsequently added blocks or segments may be only partially or entirely water insoluble thereby providing a means for preparing surface active or surfactant materials having well defined polydispersity and hydrophobe-lipophobe balance (HLB) properties.
Many known polymerization processes for the synthesis of narrow polydispersity resins, such as anionic, cationic and group transfer polymerization processes, are limited by the need for anhydrous reaction conditions and monomers which do not contain protic or reactive functional groups, for example, hydroxyl (OH), carboxyl (CO
2
H), amino (NH), carbonyl (C═O), active methylene (—CH—C═O), and the like. As a consequence, these processes are not considered readily applicable to polymerizations in the presence of water or of water soluble monomers since these monomer materials tend to be hydroscopic and any associated water or reactive functional groups may readily destroy the polymerization initiator component, for example, the hydrolysis or protonation of organolithium reagents, or in other ways, cause the polymerization to fail entirely or to be industrially inefficient.
Conventional free radical polymerization processes that are used to polymerize monomers inherently give broad polydispersity resin products or require that sophisticated processing conditions and materials handling protocols be employed.
The polymer resins produced by processes of the present invention, in embodiments, are essentially monomodal, that is the molecular weight distribution is narrow and indicative of a Poisson character and without significant shoulders or side bands. In embodiments, by repeating the heating step, comprising the combined initiation and polymerization step, there is provided a means for obtaining monomodal, mixtures of bifunctional polymer resins that are compositionally the same resin type having characteristics of both narrow polydispersity and known or selectable modality greater than or equal to 1. In embodiments, processes of the present invention provide a means for conducting free radical polymerization processes which provide bifunctional resin products on multi kilogram or larger scales. The aforementioned embodiments may be accomplished in a one or single pot reactor environment. In embodiments, polymeric chain growth proceeds by a pseudoliving mechanism and can provide resins of variable molecular weights from very low to very high, for example, less than about 2,000 up to about 200,000 while maintaining narrow molecular weight distributions or polydispersities. In embodiments, triblock and multiblock copolymers can be synthesized by the aforementioned stable free radical moderated polymerization processes wherein each block formed is well defined in length by the sequentially added and reacted monomer and wherein each additional block that is formed also possesses a narrow molecular weight distribution.
It is generally accepted that known anionic and cationic polymerization processes used for the preparation of narrow polydispersity resins, homopolymers, block and multiblock polymers, are not believed possible in aqueous or protic solvent containing polymerization media, reference the aforementioned number U.S. Pat. No. 5,312,704, issued May 17, 1994. The present invention enables the preparation of bifunctional homopolymeric, copolymeric, terpolymeric, block, triblo
Georges Michael K.
Hamer Gordon K.
Inoue Toyofumi
Kazmaier Peter M.
Veregin Richard P. N.
Choi Ling-Sui
Haack John L.
Wu David W.
Xerox Corporation
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