Ball-shaped polyester particles capable of crosslinking at low temperature, production thereof and use of same for powder lacquers

A process for preparing spherical, transparent, optionally crosslinkable polyester particles by

• a. dispersing the starting materials for a polyester binder in the form of oligoesters which have a viscosity of less than 1000 mPas (measured at 200.degree. C. in an inert high-boiling heat transfer medium at a temperature which is at least as high as the softening temperature of the starting materials, in the presence of at least one polymeric dispersion stabilizer, and
• b. then heating the reaction mixture to a temperature in the range from 120.degree. to 280.degree. C., with simultaneous removal of the condensation byproducts, until the polyester has the desired molecular weight;
• c. thereafter cooling the reaction mixture, in the case of a crosslinkable functional polyester, to a temperature in the range from 60 to 140.degree. C. and adding at least one polyfunctional crosslinking agent or epoxy resin, and
• d. subsequently reducing the temperature to within a range which is below the softening temperature of the polyester and separating off the resulting spherical polyester particles.

The process as claimed in claim 6, wherein the starting materials employed comprise units of the formulae (I) and (2)

• --CO--X--CO (1)
• --O--D--O-- (2)
• where X
• X is a substituted or unsubstituted C.sub.6 to C.sub.14 -aromatic radical or an alkylene, polymethylene, cycloalkane or dimethylenecycloalkane group or a straight-chain or branched, saturated or unsaturated alkanediyl group and
• D is an alkylene, polymethylene, cycloalkane or dimethylenecycloalkane group or a straight-chain or branched, saturated or unsaturated alkanediyl group.