Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2001-02-02
2004-05-04
Reddick, Judy M. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C427S385500, C427S389900, C427S391000, C427S393000, C524S004000, C524S005000, C524S007000, C524S494000, C525S054210, C525S054230, C525S054240, C525S054260, C525S057000, C525S061000, C525S193000, C525S194000, C525S195000, C525S337000
Reexamination Certificate
active
06730722
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to crosslinkable polymer powder compositions, to processes for preparing them, and to the use thereof.
BACKGROUND ART
Crosslinkable dispersion powders are known from U.S. Pat. No. 3,409,578 in which powder compositions comprising carboxyl-containing polymers and/or carboxyl-containing protective colloids are crosslinked in the presence of polyvalent metal ions. A disadvantage is that such compositions containing polyvalent metal salts frequently tend to release acid in the presence of water and to undergo premature crosslinking, especially on contact with moisture. EP-B 687317 describes water redispersible, crosslinkable powders based on N-methylol-functional copolymers which crosslink thermally. A disadvantage of the latter powder is the fact that powders which can be crosslinked by means of heat alone are unsuitable for use in many applications.
EP-A 721004 discloses crosslinkable, redispersible powder mixtures comprising film-forming polymer particles containing at least one functional, crosslinkable group. The crosslinkable group may also be introduced by way of the protective colloids. For crosslinking, this document recommends the addition of an external crosslinker comprising at least one reactive component which enters into nonionic bonds with the functional groups when the mixture is redispersed in water. Boron compounds are cited as an example.
It is known that boric acid and borax cause thickening and gelling of polyhydroxy compounds such as polyvinyl alcohol, cellulose, and dextran, and may therefore gel to form inclusion compounds with herbicides, for example, in the strongly alkaline range (EP-A 88552).
Since the crosslinking reaction proceeds spontaneously and, in contrast to salt coagulation, is irreversible by heating, the practical possibilities for application are very restricted. For example, a redispersible powder stabilized with polyvinyl alcohol cannot be redispersed in the presence of boric acid or borax, in an amount sufficient to gel the polyvinyl alcohol, in an aqueous medium whose pH is more than 8.
SUMMARY OF THE INVENTION
An object of the invention is therefore to provide crosslinkable polymer powder compositions which crosslink, while ensuring an appropriate processing time, even in an alkaline aqueous medium and even at room temperature.
REFERENCES:
patent: 2326539 (1943-08-01), Irany
patent: 2362761 (1944-11-01), Medl, Jr.
patent: 2453108 (1948-11-01), Curtis
patent: 3144412 (1964-08-01), Inamorato
patent: 3329523 (1967-07-01), Best et al.
patent: 3329525 (1967-07-01), Powers
patent: 3409578 (1968-11-01), Hwa et al.
patent: 3425968 (1969-02-01), Reiling
patent: 3494782 (1970-02-01), Clark et al.
patent: 3565818 (1971-02-01), Bayless et al.
patent: 3582390 (1971-06-01), Saulnier
patent: 3639234 (1972-02-01), Wixon et al.
patent: 3646098 (1972-02-01), Cyba
patent: 3703772 (1972-11-01), McHugh et al.
patent: 3755181 (1973-08-01), Henricks
patent: 3781228 (1973-12-01), McDonnell et al.
patent: 3929679 (1975-12-01), Cala
patent: 4626372 (1986-12-01), Kaufmann et al.
patent: 4828721 (1989-05-01), Bollier et al.
patent: 4980086 (1990-12-01), Hiraiwa et al.
patent: 5668216 (1997-09-01), Kinkel et al.
patent: 6083653 (2000-07-01), Baur et al.
patent: 6288009 (2001-09-01), Kober et al.
patent: 0 088 552 (1983-09-01), None
patent: 0 721 004 (1996-07-01), None
patent: 0 687 317 (1996-11-01), None
patent: 96/01853 (1996-01-01), None
patent: 99/16794 (1999-04-01), None
English Abstract corresponding to WO 99/16794.
Gmelin, Borverbindungen (boron compounds) 8, pp. 119, 129, 133, 135.
Fox T.G., Bull. Am. Physics Soc. 1 (1956) 3, p. 123.
The Polymer Handbook, 3rdEdition, J. Wiley & Sons, New York (1989).
Donislreiter Hans
Eck Herbert
Brooks & Kushman P.C.
Reddick Judy M.
Wacker-Chemie GmbH
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