Latex paint formulations and methods

DETAILED DESCRIPTION OF THE INVENTION According to the invention, a paint with an internal phase comprising pigment and latex resin and an external phase comprising an amine soluble resin dissolved in water is provided.
The amine soluble resin has a molecular weight sufficiently high that it imparts desirable film properties to the paint, while maintaining the surface applicability of the paint.
Upon evaporation of the water, the external phase is effective in forming a substantially continuous film encapsulating the internal phase.
In this formulating approach to hybrid latex paints, an amine soluble polymer, typified by the proprietary resin manufactured by S.
C.
Johnson & Son, Inc.
, U.
S.
Specialty Chemicals Division, Racine, Wis.
, and supplied in a solid flake form under the trademark Joncryl 678 or, alternatively, in a water solution form under the trademark Joncryl 61LV is used and eliminates the necessity of using dispersants and wetting agents because the solubilized resin acts to totally encapsulate the pigment and emulsion resins that are present.
Joncryl 678 is an acid functional, styrene acrylic resin having an acid value of 200.
Joncryl 61LV constitutes a styrene acrylic resin solution including:
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Joncryl 61 LV Formula
(% by wt.
)
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Joncryl 678 Styrene
35.
0
Acrylic Resin
Ammonia (28%) 7.
5
Ethylene Glycol
1.
5
Isopropyl Alcohol
5.
0
Water 51.
0
TOTAL 100.
0
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In the Joncryl 61LV styrene acrylic resin solution, it is believed that the ammonia serves primarily as a solubilizing agent and that the isopropyl alcohol and ethylene glycol are present as rheology control agents permitting the development of solutions containing a relatively great proportion of solids.
To date, the use of Joncryl 678 styrene acrylic resin with a molecular weight range of about 5,000-9,000 has been preferred with resin having a molecular weight of about 7,000 being highly preferred