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
2001-11-07
2004-04-13
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...
C428S423100, C524S591000, C524S839000, C524S840000, C524S507000, C524S539000, C525S440030, C525S455000, C525S123000, C525S127000
Reexamination Certificate
active
06720384
ABSTRACT:
The present invention relates to a coating composition consisting of at least four components, comprising a component (I) comprising at least one oligomeric or polymeric resin containing functional groups which react with isocyanate groups, as binder (A), a component (II) comprising at least one polyisocyanate as crosslinking agent (F), and a component (III) which comprises water. The present invention additionally relates to a process for preparing these coating compositions and also to the use of the coating compositions in automotive OEM finishing, refinish, and for the coating of plastics, and also as topcoat materials or primer-surfacers.
Coating compositions of the abovementioned type in which component (III) contains no binders (A) are known from the patent U.S. Pat. No. 5,466,745. One of their uses is to produce clearcoats. The surfaces of these clearcoats, however, are still unable to satisfy every quality requirement, since they have pinholes and blisters.
Coating compositions of the abovementioned type in which component (III) comprises dissolved or dispersed binders (A) are known from the German patents DE-A-195 42 626 and DE-A-44 21 823. These known coating compositions already have comparatively few surface problems, such as popping marks or structuring, and as regards gloss, relaxation, spraying reliability, fullness, weathering stability, and other important technological properties they possess a good profile of properties.
The increasingly more stringent requirements of the market, however, are making it necessary to improve these known coating compositions still further in terms of their homogeneity, stability, handling, and popping limits. Moreover, the solvent content is to be lowered further than has been possible to date. Furthermore, the resulting coatings should have an even higher gasoline resistance and an even lower gray haze.
These known coating compositions or their component (III) comprise binders in dispersion or solution in water, which in the dissolved or dispersed state, especially on prolonged storage, are infested and destroyed by microorganisms, thereby rendering the component (III) in question of the coating compositions unusable and requiring disposal, which is a grave disadvantage both technically and economically.
If the component (III) affected is used anyway, it produces coatings, especially clearcoats, which are no longer in accordance with user requirements, especially in the automobile industry.
It is an object of the present invention to find a novel coating composition which no longer has the disadvantages depicted above but which instead is infested to a considerably reduced extent, if at all, by microorganisms and therefore has a relatively high storage stability of the component in question, with the advantageous properties of the known coating compositions being at least retained if not indeed improved further.
The invention accordingly provides the novel coating composition consisting of at least four components, comprising
(I) a component comprising at least one oligomeric or polymeric resin containing functional groups which react with isocyanate groups, as binder (A).
(II) a component comprising at least one polyisocyanate as crosslinking agent (F),
(III) a component which comprises water and is substantially free from acrylate copolymers (A) dispersed or dissolved therein, and
(IV) a finely divided solid component which comprises at least one water-soluble or -dispersible finely divided solid acrylate copolymer (A).
In the text below, the novel coating composition consisting of at least four components is referred to for the sake of brevity as the “coating composition of the inventions”.
The present invention further provides a process for preparing the coating compositions of the invention, and also provides for their use in automotive OEM finishing, refinish, and the coating of plastics, as topcoat materials or primer-surfacers.
The coating compositions of the invention are notable, surprisingly, for a profile of properties which is improved over the prior art in relation in particular to the gloss, fullness, low popping tendency, spraying reliability, and leveling, and also in respect of the weathering stability.
The particular advantage of the coating composition of the invention is firstly that component (III) is substantially-free from dissolved or dispersed acrylate copolymers (A), so that even on prolonged storage it is no longer infested by microorganisms, or only to an extent which does not perceptibly impair its performance properties. Secondly, the particular advantage of the coating compositions of the invention is that component (IV) may be stored for a particularly long time without detriment to its performance properties. Furthermore, as a finely divided solid, it can be added to the coating composition, especially to component (III), in a particularly simple and easy fashion.
It is surprising, furthermore, that the coating compositions of the invention comprising said at least four components may be prepared simply by mixing without the need for complicated mixing and/or dispersing apparatus as described, for example, in the German patent DE-A-195 10 651. The coating compositions of the invention are therefore suitable in particular for the field of automotive refinish, since they can be prepared by the painter by simple mixing of the components directly prior to their application and can be cured at low temperatures.
A further advantage is that the coating compositions of the invention prepared from said at least four components contain only a small fraction of volatile organic solvents, despite the fact that the coating compositions are prepared using crosslinkers and binders dispersed and/or dissolved in organic media.
Moreover, the coating compositions of the invention ensure a high level of variability, since it is possible to use not only the crosslinking agents, pigments and additives that are recommended for aqueous coating compositions but also those used in conventional systems.
Finally, a feature of the inventive components of the coating compositions of the invention is a very good storage stability, which corresponds to that of conventional coating compositions.
The constituent of the coating composition of the invention that is essential to the invention is its finely divided solid component (IV), which comprises at least one water-soluble or -dispersible finely divided solid acrylate copolymer (A).
The finely divided solid acrylate copolymers (A) for use in accordance with the invention are oligomeric or polymeric resins containing functional groups which react with isocyanate groups.
Examples of suitable functional groups for use in accordance with the invention that react with isocyanate groups are epoxy, amino, thio and/or hydroxyl groups, of which the hydroxyl groups are particularly advantageous and are therefore particularly preferred in accordance with the invention.
Accordingly, the finely divided solid acrylate copolymers (A) which are preferred in accordance with the invention comprise hydroxyl-containing oligomeric or polymeric resins.
Besides the hydroxyl groups, the finely divided solid acrylate copolymers (A) may contain other functional groups as well, such as acryloyl, amide, imide, carbonate or epoxide groups.
In accordance with the invention, the finely divided solid acrylate copolymers (A), viewed per se, are dispersible or soluble in water.
Examples of suitable water-soluble or water-dispersible finely divided solid acrylate copolymers (A) contain alternatively
(i) functional groups which can be converted into cations by neutralizing agents and/or quaternizing agents, and/or cationic groups,
or
(ii) functional groups which can be converted into anions by neutralizing agents, and/or anionic groups,
and/or
(iii) nonionic hydrophilic groups.
Examples of suitable functional groups (i) for use in accordance with the invention that can be converted into cations by neutralizing agents and/or quaternizing agents are primary, secondary or tertiary amino groups, secondary sulfi
Mayer Bernd
Rink Heinz-Peter
BASF Coatings AC
Niland Patrick D.
LandOfFree
Coating agent comprising at least four components, method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coating agent comprising at least four components, method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coating agent comprising at least four components, method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3229143