Process for coating inorganic particles with condensating polymers

DETAILED DESCRIPTION OF THE INVENTION While it has been found that long chain polybutenes or polyisobutylenes to which anchor groups and linking groups are attached and in which carbon-to-carbon double bonds may be halogenated are highly useful dispersing agents in the instant process, it has been found that particularly good results are achieved when the dispersing agent is the reaction product of a polybutene of a molecular weight of 1000-10000 and maleic anhydride imidized at least in part by an aliphatic amine.
The halogenation of the double bonds tends to prevent high temperature degradation of the dispersing agent.
Examples of suitable amines are ethylenediamine, diethylene triamine and tetraethylene pentamine.
It has been found that a particularly useful example of the preferred class of dispersing agents is the crankcase oil dispersant Amoco 9250 sold by Amoco, Inc.
This latter dispersing agent has been found to be particularly useful when the solid monomer is 11-aminoundecanoic acid.
While, as the liquid solvent, any organic liquid with sufficiently high boiling point that is inert to the monomer at the reaction conditions may be used, it has been found that best results are achieved with high boiling liquid aliphatic or aromatic hydrocarbons having a boiling point of at least 165.
degree.
C.
, specific examples of which are Decalin, odorless kerosene with boiling point 175.
degree.
-200.
degree.
C.
, such as Shellsol T sold by the Shell Oil Co.
and Isopar H sold by Exxon.
While the process of the invention may be used for the production of any polymer coated pigment particles such as that of the condensation and addition polymers such as polyesters, polyamides, polyurethanes, and polyureas it is particularly useful in the production of polyamide-coated pigment particles.
For a more complete understanding the invention will now be described with reference to the following specific example.
EXAMPLE I The following suspensions were prepared by ball milling: Suspension A, which contained per liter of suspension 556 g-TiO