Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1997-01-15
1999-06-29
Zitomer, Fred
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
524115, 524116, 524117, 524119, 5253265, 5253304, 525340, 526279, C08K 5524, C08K 551
Patent
active
059169389
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a coating composition which contains organic solvent and is based on a solution of a polyacrylate resin (A) in one or more organic solvents, containing one or more organic phosphites.
The present invention further relates to the use of the coating compositions in processes for producing a multilayer, protective and/or decorative coating on a substrate surface, and to the use of the coating compositions as topcoats, in particular as transparent topcoats.
Multilayer coatings, especially two-coat metallic coatings, are produced principally by the basecoat/clearcoat process. This process is known and is described in, for example, U.S. Pat. No. 3,639,147 and EP-A-38 127.
The basecoat/clearcoat process can be used to prepare coatings which, in comparison with one-coat finishes, are distinguished by an improved effect and by the possibility of producing coatings having brighter and cleaner colors.
The basecoat which is initially applied determines, depending on the nature, quantity and spatial orientation of the pigments employed, the color and, if appropriate, the effect (e.g. metallic effect or pearlescent effect) of the coating.
After the basecoat has been applied, at least part of the organic solvents and/or at least part of the water is or are removed from the applied basecoat film in an evaporation phase. A nonaqueous, transparent topcoat is then applied to this pre-dried basecoat (wet-on-wet method). Subsequently, basecoat and topcoat are then dried together.
The transparent topcoat applied gives the two-coat finish gloss and fullness, and protects the applied pigmented coat against chemical and physical attack.
Important properties which the transparent topcoat obtained after the drying process is required to have are good adhesion to the basecoat, a good visual effect, high transparency, very good topcoat holdout, good gloss and good mechanical properties, such as hardness, mar-resistance and elasticity. The transparent topcoat obtained after the drying process must not least exhibit a high resistance to climatic effects (e.g. temperature fluctuations, moisture in the form of steam, rain, dew, the action of radiation, etc.) and to attack by acids or other chemicals, for example organic solvents.
In particular, the coating compositions employed as topcoat must, for visual reasons, have minimal inherent color (a color number which is as low as possible) so that, for example, changes in color are avoided in the case of light pearl-effect basecoats and metallic basecoats.
The production of coating compositions of minimal color number is possible when yellowing components are rigorously excluded from all of the components. Thus the polyacrylate resin solutions customarily employed at present for the production of transparent topcoats do indeed have a relatively low color number, but a further improvement is entirely desirable.
For example, DE-A-38 23 005, DE-A-35 34 874, DE-A-39 18 669 and DE-A-40 24 204 disclose coating compositions based on polyacrylate resin solutions.
Furthermore, German Patent Application P 44 07 409.3, which is not a prior publication, discloses coating compositions containing, as binder, a solution of a hydroxyl-containing polyacrylate resin which has been prepared using 4-hydroxy-n-butyl (meth)acrylate and/or 3-hydroxy-n-butyl (meth)acrylate as monomer component.
Finally, coating compositions known from German Patent Application P 44 07 415.8, which is not a prior publication, contain as binder a solution of a hydroxyl-containing polyacrylate resin which has been prepared using cycloaliphatic esters of (meth)acrylic acid and hydroxyl-containing monomers which are chosen such that polymerization of the OH monomers alone gives a poly(meth)acrylate resin having a glass transition temperature of from -10 to 6.degree. C. or from 60 to 80.degree. C.
With all of these specified coating compositions, however, a further improvement in the color number is entirely desirable. With this in mind, however, it must be ensured that the other properties of the coating
REFERENCES:
patent: 3055861 (1962-09-01), Hersh
patent: 5006578 (1991-04-01), Masuda
patent: 5276097 (1994-01-01), Hoffmann
patent: 5276104 (1994-01-01), Hoffmann
patent: 5483004 (1996-01-01), Hoffmann
Borgholte Harald
Brunnemann Michael
Hoffmann Peter
Jung Werner-Alfons
Rink Heinz-Peter
BASF Coatings AG
Zitomer Fred
LandOfFree
Polyacrylate resin solutions having improved color number, and t does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polyacrylate resin solutions having improved color number, and t, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyacrylate resin solutions having improved color number, and t will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1375821