Waterborne coating compositions for automotive applications
AssigneePPG Industries, Inc.
InventorsRoxalana L. Martin, Barbara G. Piccirilli, Dennis L. Faler
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Abstract
A waterborne coating composition having a total solids content at application of greater than 30 percent, contains pigment and a dispersion of polymeric microparticles in an aqueous medium. The microparticles contain greater than 30 percent by weight based on the microparticles of a substantially hydrophobic polymer which is essentially free of repeating acrylic or vinyl units in the backbone, has a molecular weight greater than 300 and is adapted to be chemically bound into the cured coating composition. The aqueous medium of the microparticle dispersion is substantially free of water soluble polymer.
Claims11
A waterborne coating composition wherein the volatile organic content is less than 3.5 pounds per gallon and having a total solids content at application of greater than 30 percent, comprising pigment, crosslinking agent and a dispersion of polymeric microparticles in an aqueous medium wherein the microparticles are prepared by forming a mixture in aqueous medium of a vinyl monomer or mixture of vinyl monomers with greater than 30 percent by weight based on the microparticles of a polymer which is substantially hydrophobic such that when the polymer is mixed with the aqueous medium and vinyl monomer or mixture of vinyl monomers a majority of the polymer is in the organic phase and a separate aqueous phase is obtained;
- said polymer being essentially free of repeating acrylic or vinyl units in the backbone, has a molecular weight greater than 300 and contains functional groups which are capable of reacting with the crosslink agent;
- and particularizing said mixture into microparticles by high stress techniques followed by polymerizing the polymerizable species within the microparticles to produce the polymeric microparticles which are stably dispersed in the aqueous medium;
- and the aqueous medium of the microparticle dispersion being substantially free of water soluble polymer.
A waterborne coating composition wherein the volatile organic consent is less than 3.5 pounds per gallon and having a total solids content at application of greater than 30 percent, comprising crosslinking agent and a dispersion of polymeric microparticles in an aqueous medium wherein the microparticles are prepared by forming a mixture in aqueous medium of a vinyl monomer or mixture of vinyl monomers with greater than 30 percent by weight based on the microparticles of a polymer which is substantially hydrophobic such that when the polymer is mixed with the aqueous medium and vinyl monomer or mixture of vinyl monomers a majority of the polymer is in the organic phase and a separate aqueous phase is obtained;
- said polymer being essentially free of repeating acrylic or vinyl units in the backbone, has a molecular width greater than 300 and contains functional groups which are capable of reacting with the crosslinking agent;
- and particulation said mixture into microparticles by high stress techniques followed by polymerizing the polymerizable species within the microparticles to produce the polymeric microparticles which are stably dispersed in the aqueous medium;
- the aqueous medium of the microparticle dispersion being substantially free of water soluble polymer.
Dependencies are inferred from the claim text.