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...
Patent
1992-07-10
1995-05-02
Morgan, Kriellion S.
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...
524542, C08L 5100, C08L 6100
Patent
active
054120233
DESCRIPTION:
BRIEF SUMMARY
The invention relates to aqueous dispersions of cross-linked polymer microparticles, the use thereof, a process for producing same and coating compositions containing said dispersions.
It is generally desirable to reduce the proportion of organic solvents in coating compositions.
There is great interest in aqueous lacquer systems, and especially so in the field of automotive painting, but also in other areas.
The use of aqueous lacquer systems involves a number of problems associated with the chemical and physical properties of water. Thus, e.g., the rheology (course of the viscosity during application, pseudo-plasticity, thixotropy, levelling and run-off properties) of conventional lacquer systems is to be purposefully controlled by relatively simple means via the evaporation behavior of the employed organic solvents or solvent mixtures, respectively. These possibilities can be utilized in aqueous systems either to a much restricted extent or even not at all.
However, a control of the rheologic properties of the coating compositions employed is of an extraordinarily high importance in the production of high-quality multilayer coatings, and especially of coatings exhibiting a metallic effect.
Thus, e.g., a steep viscosity rise after the application has a very beneficial effect onto the orientation and fixation of the metal pigment particles in metallic effect base coating.
What gives rise to problems, however, is the compatibility with the aqueous binder systems of the metal pigment particles, since, especially when aluminum particles are used as the metal pigment, the metal is amphoteric and is readily attacked with concomitant hydrogen evolution.
But also in other coating procedures, and more particularly so in the case of coatings deposited by spray applications, the quality of the resulting coatings to a high degree depends on the rheologic properties of the coating compositions employed.
It has been known that the rheologic properties of aqueous coating compositions can be affected by the addition of cross-linked polymer microparticles.
EP-A-0 038 127 describes a process for producing a multilayer coating on a substrate surface, wherein the base coat composition is derived from a dispersion of cross-linked polymer microparticles, said dispersion having been prepared in an aqueous medium. The polymer microparticles consisting of polymers of alkyl esters of acrylic or methacrylic acids were prepared therein by dispersion polymerization in water and one further organic solvent in the presence of a certain polymeric stabilizer.
EP-A-0 320 689 describes a stable non-aqueous dispersion of microparticles, prepared from an aminoplast resin and a material containing OH groups in a preferably non-polar solvent in the presence of an organic sulfonic acid and a stabilizer.
EP-A-0 103 174 describes a process for the production of aqueous dispersions of cross-linked polyurethane ionomers by the reaction with polyfunctional compounds of prepolymers bearing isocyanate groups. Said process is characterized in that polyurethane prepolymers containing incorporated salt groups and having aliphatically and/or cycloaliphatically bonded terminal isocyanate groups are mixed with polyfunctional polyisocyanates in a water-miscible organic solvent, the resulting solution is dispersed in water, and the organic solvent is evaporated.
U.S. Pat. Nos. 4,408,008 and 4,293,679 also describe a process for the production of polymer microparticles from polyisocyanate; however, said printed publications fail to contain any reference to that the dispersions disclosed therein are capable of being employed in aqueous coating systems.
In principle, all of these processes are based on two different methods or particle formation: water-insoluble monomers by means of surfactants which will form micelles above some definite concentration. This process of an emulsion polymerization has already been known for a long time and is used on a commercial large scale for the production of a great variety of plastics dispersions. In order to obtain cross-l
REFERENCES:
patent: 3133032 (1964-05-01), Jen et al.
patent: 3870684 (1975-03-01), Witt et al.
patent: 4293679 (1981-10-01), Cogliano
patent: 4408008 (1983-10-01), Markusch
patent: 4507431 (1985-03-01), Stutz et al.
patent: 4525520 (1985-06-01), Shioi et al.
patent: 4783497 (1988-11-01), Thompson
patent: 4942198 (1990-07-01), Dickerhof et al.
patent: 4945128 (1990-07-01), Hille et al.
patent: 5043380 (1991-08-01), Cole
patent: 5075372 (1991-12-01), Hille et al.
patent: 5200461 (1993-04-01), Tsuchiya et al.
Hille Hans-Dieter
Massone Matthias
Bollig & Kemper KG
Morgan Kriellion S.
LandOfFree
Aqueous dispersions of cross-linked polymer microparticles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aqueous dispersions of cross-linked polymer microparticles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous dispersions of cross-linked polymer microparticles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1137717