Aqueous sheet silicate dispersions, use of these dispersions as

Details Aqueous sheet silicate dispersions, use of these dispersions as Aqueous sheet silicate dispersions, use of these dispersions as

1989-10-16

1993-03-30

Bleutge, John C.

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...

524444, 524445, 524446, 524448, 524612, 252310, 2523131, 2523155, 2523132, C08F 3718, C09D 1700

Patent

active

051984903

DESCRIPTION:

BRIEF SUMMARY
The invention relates to dispersions which are obtainable from sheet silicates, a protective colloid and an aqueous dispersant and are suitable for the incorporation of sheet silicates into water-dilutable coating compositions.
Water-dilutable coating compositions, in particular those which are to be processed by spray application, for example in automotive coating, must have very particular rheological properties. An especially important role is played by the rheological properties in the case of water-dilutable coating compositions which contain metal pigments and are used for the production of the base coat of a two-coat system of the base coat/clear coat type (cf. for example European Patent 38 127).
The rheological properties of water-dilutable coating compositions very decisively influence the application properties of the coating compositions. In the case of water-dilutable coating compositions containing metal pigments, the orientation of the metal pigment particles and hence the achievable metallic effect depend very substantially on the rheological properties of the coating compositions.
To control the rheological properties of aqueous coating compositions, sheet silicates are extensively used. The sheet silicates swell in water and form gels, which have a high flow limit and low plastic viscosity when subjected to shearing.
Incorporation of the sheet silicates into the water-dilutable coating compositions is preferably effected via dispersions which are prepared from a sheet silicate, modified with an anionic protective colloid (for example tetrasodium pyrophosphate), and water. These dispersions have a sol character instead of a gel character and can be incorporated into the water-dilutable coating compositions simply by metering in. On mixing, the effect of the protective colloid is eliminated, and the sheet silicate can display its action as a viscosity assistant.
If the dispersions described above are incorporated into water-dilutable coating compositions, coating compositions are obtained which have poor spray application properties and give moisture-sensitive, poorly adhering coatings. These difficulties occur to a greater extent in the case of water-dilutable coating compositions which contain metal pigments, preferably aluminum pigments in flake form, and are intended to be used for the production of the base coat of a two-coat system of the base coat/clear coat type. In these cases, moisture-sensitive, poorly adhering coatings which have only an inadequate metallic effect are obtained.
It is the object of the invention to provide sheet silicate dispersions which can be readily incorporated into water-dilutable coating compositions and can be used to obtain water-dilutable coating compositions which have optimum rheological properties and good spray application properties and which give moisture-insensitive coatings having good adhesion. It is the particular object of the invention to provide sheet silicate dispersions which can readily be incorporated into water-dilutable coating compositions containing metal pigments suitable for the production of the base coat of a two-coat system of the base coat/clear coat type and which can be used to obtain water-dilutable coating compositions which contain metal pigments and have optimum rheological properties and good spray application properties and can be processed to give moisture-insensitive two-coat metallic effect coatings of the base coat/clear coat type which have a good effect and good adhesion.
This object is achieved, according to the invention, by dispersions of the type stated at the outset, wherein the said dispersions are obtainable using poly(propylene oxide) as a protective colloid, and the poly(propylene oxide) contains no hydrophobic terminal groups, has on average at least one hydroxyl group per molecule and may optionally contain up to 40% by weight of --CH.sub.2 --CH.sub.2 --O-- units.
The invention also relates to water-dilutable coating compositions which contain a sheet silicate, water, binders, if necessary pigments, or

REFERENCES:
patent: 3687885 (1972-08-01), Abriss et al.
patent: 3998973 (1976-12-01), Carlson
patent: 4017452 (1977-04-01), Schwartz
patent: 4243565 (1981-01-01), Nishino et al.
patent: 4304708 (1981-12-01), Marx et al.
patent: 4351754 (1982-09-01), Dupre
patent: 4385138 (1983-05-01), Sagane et al.
patent: 4436862 (1984-03-01), Tetenbaun et al.
patent: 4476271 (1984-10-01), Kano et al.
patent: 4543376 (1985-09-01), Schupp et al.

Affiliated with

Also associated with

Rating

Aqueous sheet silicate dispersions, use of these dispersions as 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 sheet silicate dispersions, use of these dispersions as , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous sheet silicate dispersions, use of these dispersions as will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1281505