Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1998-10-29
2002-01-08
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S215000, C523S216000, C252S183140
Reexamination Certificate
active
06337358
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to particles, such as carbon black, having an attached stable free radical which permits the formation of modified particles having blocked radical sources. The present invention further relates to methods of preparing and using such modified particles.
The role of carbon black as a thermal stabilizer in polymeric systems is discussed by W. L. Hawkins, R. H. Hansen, W. Matreyek, F. H. Winslow; J.
Applied Polymer Science
, vol. 1, pages 37-42, 1959; J. T. Cruver, K. W. Rollmann:
J. Applied Polymer Science
, vol. 8, pages 1169-83, 1964, and by G. Ivan, M. Giurgina:
Revue Rotimaine de Chemie
, vol. 29, number 8, pages 639-646, 1984. In each discussion the mechanism is through phenolic and quinone oxygen groups on the carbon black surface behaving either as radical traps or peroxide decomposers. One skilled in the art, however, would consider these sites unavailable as initiating sites for polymerization processes.
Belmont et al. (J. A. Belmont, J. M. Funt: International Rubber Conference, Essen, Germany, June 24-27 1991) identified the presence of peroxide groups, typically in the range of 0.1 to 0.4 micromoles/sq meter, on the carbon black surface. However, the majority (greater than 80%) of the peroxide groups are thermally stable to heat treatment at 200° C. and hence cannot be considered to be potential initiating sites for radical polymerization.
Tsubokawa et al. (K. Fujiki, N. Tsubokawa, Y. Sone:
Polymer J
., vol. 22, number 8, pages 661-70, 1990, and N. Tsubokawa:
Prog. Polymer Science
, vol. 17, pages 417-70, 1992) discuss growing polymers from an activated carbon black surface by first attaching a reactive group via the oxygen groups on the carbon black surface. Typical examples include the use of glycidyl methacrylate where the glycidyl group reacts with phenolic hydroxyl groups on the carbon black surface providing a vinyl functionality; the reaction of 4,4′ azo bis-(4-cyanovaleric acid) whereby the isocyanate group reacts with phenolic hydroxyl groups and subsequent heating decomposes the azo group to generate an alkyl radical; and the reaction of the phenolic hydroxyl groups with butyl lithium which can then be used as an initiation site for anionic polymerization.
All of these approaches require the presence of oxygen groups on the carbon black surface. Since the level of reactive hydroxyl and carboxylic acid groups, relative to the above approaches, present on a typical furnace or thermal carbon black is typically 0.01 to 0.1 micromoles/sq meter, the number of potential initiation sites is quite low.
Further, subsequent polymerization from these activated sites will most likely occur in the normal manner for free radical polymerization with the chains being irreversible terminated by chain combination reactions, combination with unreacted oxygen groups on the carbon black surface, and/or the addition of chain stoppers. In all cases the polymerization cannot be reinitiated. Accordingly, there is a need to provide particles with attached stable free radicals which overcome the above-described limitations.
SUMMARY OF THE INVENTION
In accordance with the purposes of the present invention, the present invention relates to a modified particle which includes a particle having an attached group having the formula:
wherein A represents an aromatic group or an alkyl group; R
1
represents a bond, an arylene group, an alkylene group,
wherein R
4
is an alkyl or alkylene group or an aryl or arylene group; R
2
and R
3
, which can be the same or different, represent hydrogen, an alkyl group, an aryl group, —OR
5
, —NHR
5
, —NR
5
R
5
or —SR
5
, wherein R
5
, which can be the same or different, represents hydrogen, an alkyl group or an aryl group; and SFR represents a stable free radical.
The present invention further relates to a modified particle or aggregate wherein the particle or aggregate is a carbon-metal multiphase aggregate, a carbon-silicon containing species multiphase aggregate, a metal oxide, or a metal hydroxide. Attached to the particle or aggregate is a group having the formula:
wherein CoupA represents a Si-containing group, a Ti-containing group, a Cr-containing group, or a Zr-containing group; R
8
and R
9
, which can be the same or different, represent hydrogen, an alkyl group, an aryl group, —OR
10
, —NHR
10
, —NR
10
R
10
, or —SR
10
, wherein R
10
, which can be the same or different, represents hydrogen, an alkyl group or an aryl group; SFR represents a stable free radical, and n is an integer of from 1 to 3.
The present invention further relates to a modified particle with an attached polymer or blocked radical sources, wherein the modified particle has an attached group having the formula:
wherein X represents blocked radical sources or a polymer formed from at least one polymerizable vinyl or diene based monomer, A represents an aromatic group or alkyl group; R
1
represents a bond, an arylene group, an alkylene group,
wherein R
4
is an alkyl or alkylene group or an aryl or arylene group; R
2
and R
3
, which can be the same or different, represent hydrogen, an alkyl group, an aryl group, —OR
5
, —NHR
5
, —NR
5
R
5
or —SR
5
, wherein R
5
, which can be the same or different, represents an alkyl group or an aryl group; and SFR represents a stable free radical.
The present invention also relates to another modified particle having an attached polymer. The particle is a carbon-metal multiphase aggregate, a carbon-silicon containing species multiphase aggregate, a metal oxide, or a metal hydroxide. Attached to the particle is a group having the formula:
wherein CoupA represents a Si-containing group, a Ti-containing group, a Cr-containing group, or a Zr-containing group; R
8
and R
9
, which can be the same or different, represent hydrogen, an alkyl group, an aryl group, —OR
10
, —NHR
10
, —NR
10
R
10
, or —SR
10
, wherein R
10
, which can be the same or different, represents an alkyl group or an aryl group; SFR represents a stable free radical, X is blocked radical sources or a polymer formed from at least one polymerizable vinyl or diene containing monomer, and n is an integer of from 1 to 3.
The present invention, in addition, relates to a method for preparing and using these various modified particles. The method includes reacting a particle having an attached vinyl substituted alkyl group with a reactive free radical source and a stable free radical source to form a reaction product. The present application further relates to forming the modified particles with an attached blocked radical source or polymer by reacting the reaction product with a polymerizable vinyl or diene containing monolayer.
The present invention further relates to a method of making a modified particle comprising a particle having attached a group having the formula:
wherein A represents an aromatic group or an alkyl group; R
1
represents a bond, an arylene group, an alkylene group,
wherein R
4
is an alkyl or alkylene group or an aryl or arylene group; R
2
and R
3
, which can be the same or different, represent hydrogen, an alkyl group, an aryl group, —OR
5
, —NHR
5
, —NR
5
R
5
, or —SR
5
, wherein R
5
, which is the same or different, represents an alkyl group or an aryl group; and SFR represents a stable free radical, wherein said method comprises reacting a) a particle having attached an aromatic group or an alkyl group with a group containing an abstractable proton and which leaves behind a carbon-centered radical when the proton is abstracted with b) a reactive free radical source and c) a stable free radical source.
The present invention, in addition, relates to a modified particle which includes a particle having an organic group having a —SFR group, where the organic group is directly attached to the particle. The modified particle can also be a particle having an organic group having an —X—SFR group, where the organic group is directly attached to the particle.
The present invention further relates to polymer-modified particles or aggregates where the —SFR group is replaced or terminated wi
Devonport Wayne
Rawalpally Thimma
Tu Hairuo
Warley Russell L.
Whitehouse Robert S.
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