Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2002-07-12
2004-04-13
Wilson, D. R. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S145000, C526S146000, C526S147000, C525S316000, C525S242000, C525S247000, C525S313000, C525S314000, C525S305000
Reexamination Certificate
active
06720395
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a vinyl polymer having an extended chain or a stellar structure, a method of producing the same, and a composition comprising said polymer.
BACKGROUND ART
A stellar polymer is a polymer comprising a central portion and linear polymer arms radially extending therefrom and is known to have various properties differentiating itself from linear polymers. The methods of producing stellar polymers are roughly classified into two groups. In one group, polymer arms are grown from a compound constituting the center and, in the other, polymer molecules to constitute arms are first produced and then joined together to form a stellar form. As a method usable for joining the arms, there can be mentioned the method comprising reacting the arms with a compound having a plurality of functional groups capable of reacting with the terminal functional groups of the arms and the method comprising adding a compound having a plurality of polymerizable groups following polymerization of the arms.
The polymers capable of constituting such stellar polymers may be homopolymers or copolymers, including various species such as polystyrene, poly(meth)acrylates, polydienes, polyethers, polyesters and polysiloxanes, among others. For obtaining controlled stellar structures, it is necessary that the polymerization be controlled irrespective of which method is employed, so that anionic polymerization, living cationic polymerization or polycondensation is employed in most instances.
Apart from those polymers obtained by ionic polymerization or polycondensation mentioned above by way of example, vinyl polymers obtained by radical polymerization and having a stellar structure have virtually not been put to practical use. In particular, the method of achieving chain extension or constructing a stellar structure by joining polymerization growing termini has failed. Among vinyl polymers, (meth)acrylic polymers have some characteristics, such as high weathering resistance and transparency, that are not possessed by the above-mentioned polyether polymers, hydrocarbon polymers or polyester polymers. Thus, (meth)acrylic polymers having an alkenyl group or crosslinking silyl group on a side chain have been used in high weathering resistance paint compositions and so forth. However, it is not easy to control the polymerization for acrylic polymers owing to side reactions, and therefore it is very difficult to realize chain extension or construct a stellar structure.
Accordingly, the present invention has for its object to provide a method of producing a polymer comprising a radical polymerizable vinyl monomer and having extended chains or a stellar structure on polymerization as well as the polymer, further, to a composition in which said polymer is used.
SUMMARY OF THE INVENTION
The above-mentioned chain-extended polymer or stellar polymer can be produced by adding a coupling agent represented by a chemical formula selected from among the general formulas 1, 2 and 3 shown below at the end point of living polymerization, preferably atom transfer radical polymerization:
(In the above formula, R
1
is a group selected from among Ph, CN and CO
2
R
3
(R
3
being a monovalent organic group), R
2
is an organic group having a valency of not less than two, and n is an integer of not less than 2);
(In the above formula, R
4
is H, Me or a group selected from among organic groups containing 1 to 20 carbon atoms, R
5
is a benzene or naphthalene group having two or more substituted groups and n is an integer of 2 or more);
(In the above formula, R
6
is H, Me, CN or a group selected from among organic groups containing 1 to 20 carbon atoms, R
7
is an organic group having a valency of not less than two and n is an integer of not less than 2).
When, in this production method, a compound having a functional group other than the polymerization initiating functional group is used as an initiator, a chain-extended polymer or stellar polymer terminally having said functional group is obtained.
The present invention is also concerned with a polymer prepared by the method of the present invention. Said polymer, however, is not limited to the one obtained by the method of the present invention.
The polymer of the present invention has characteristics that the molecular weight distribution is narrow.
Further, a hydroxyl-terminated polymer according to the present invention, when combined with a compound having, in each molecule thereof, not less than two functional groups reactive with the hydroxyl group, gives a curable composition.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is related to a method of producing a chain-extended polymer or a stellar polymer by polymerizing a vinyl monomer in the manner of living radical polymerization and adding a compound having two or more polymerizable carbon-carbon double bonds at the end point of polymerization.
The compound having two or more polymerizable carbon-carbon double bonds is not particularly restricted but is preferably a compound represented by a chemical formula selected from among the general formulas 1, 2 and 3 shown below:
(In the above formula, R
1
is a group selected from among Ph, CN and CO
2
R
3
(R
3
being a monovalent organic group), R
2
is an organic group having a valency of not less than two and n is an integer of not less than 2);
(In the above formula, R
4
is H, Me or a group selected from among organic groups containing 1 to 20 carbon atoms, R
5
is a benzene or naphthalene group having two or more substituted groups and n is an integer of 2 or more);
(In the above formula, R
6
is H, Me, CN or a group selected from among organic groups containing 1 to 20 carbon atoms, R
7
is an organic group having a valency of not less than two and n is an integer of not less than 2).)
These compounds will be described in detail hereinafter.
In the following, the technique of living polymerization is first described.
Living polymerization is a radical polymerization in which polymerization termini do not lose but retain their activity. While, in a narrow sense, the term “living polymerization” means a polymerization in which termini always maintain their activity, it generally includes quasi-living polymerization in which molecules terminally inactivated and molecules terminally activated are in equilibrium. In the present invention, the latter definition applies. In recent years, living radical polymerization has been studied actively by various groups. As an example, there may be mentioned the use of a cobalt-porphyllin complex (J. Am. Chem. Soc., 1994, 116, 7943) or of a radical scavenger such as a nitroxide compound (Macromolecules, 1994, 27, 7228), or the technique of atom transfer radical polymerization using an organic halide or the like as an initiator and a transition metal complex as a catalyst. In the atom transfer radical polymerization, polymerization is carried out using an organic halide, a halogenated sulfonyl compound or the like as an initiator and, as a catalyst, a metal complex containing a transition metal as a central atom. Specifically, reference may be made to the reports by Matyjaszewski et al.: J. Am. Chem. Soc., 1995, 111, 5614; Macromolecules, 1995, 28, 7901; Science, 1996, 272, 866, or the report by Sawamoto et al.: Macromoelcules, 1995, 28, 1721, International Laid-open Patent Applications WO 96/30421 and WO 97/18247, among others. In these methods, the polymerization proceeds in a living manner, generally at a very high rate of polymerization, to give a polymer with a narrow molecular weight distribution (namely an Mw/Mn value of about 1.1 to 1.5), in spite of its falling under the category of radical polymerization where termination reactions such as coupling of radicals with one another tend to occur. The molecular weight can be freely controlled by varying the charging ratio between the monomer and initiator.
In the present invention, which of those methods is employed is not particularly limited. From the viewpoint of ease of control, however, atom transfer radical polymerizati
Connolly Bove & Lodge & Hutz LLP
Kaneka Corporation
Wilson D. R.
LandOfFree
Method for producing a stellar polymer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing a stellar polymer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing a stellar polymer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3189390