A high gloss coating on a mineral substrate, such as a roof tile or floor tile, can be achieved by a method comprising: i) applying a first coating consisting of an aqueous composition comprising a film forming polymeric binder to a surface of the uncured substrate; ii) exposing said first coating to hot air or infrared, ultraviolet or microwave radiation, for sufficient time for at least the surface of said coating remote from the substrate body to form a film of polymeric binder, and iii) applying a second coating consisting of an aqueous composition comprising a film forming polymeric binder on top of the first coating. After application of the second coating, the substrate and coatings are dried and cured, for example in an oven or autoclave.

A process for producing a thermoplastic polymer powder which comprises adding a polymer (B) and/or an inorganic compound (C) to a coagulation slurry or a powder of a thermoplastic polymer (A) obtained from emulsion polymerization and having a glass transition temperature Tg defined by the following equation (1), in an amount of 0.1-10 parts by weight to 100 parts by weight of the thermoplastic polymer (A), compacting the thermoplastic polymer (A) at a temperature in a range of (Tg-30) to (Tg+50).degree. C., and comminuting it: wherein n is the number of the monomers forming the thermoplastic polymer (A); W.sub.1, W.sub.2, . . . W.sub.n each represents weight fraction of each monomer i (i=1, 2, . . . n) in the polymer (A); and Tg.sub.1, Tg.sub.2, . . . Tg.sub.n each represents the glass transition temperature of the polymer composed of each monomer i. According to the present invention, it is possible to remarkably enhance bulk specific gravity of thermoplastic polymers as compared with the case using the methods known in the art.

A polymer powder obtained by drying an aqueous polymer dispersion, wherein the aqueous polymer dispersion is obtained by free-radical polymerization of unsaturated monomers and contains at least one added starch-degradation product which is obtained by hydrolysis in the aqueous phase, is water soluble at room temperature and has a weight average molecular weight M.sub.w of from 2500 to 25000.

An electrically conductive paint for applying to substrates to make articles of manufacture including EMI/RFI shielded housings of electronic components and printing plates comprises a cross-linked organic resin binder containing cross-linkable functional groups such as OH groups, electrically conductive metallic particles, preferably a mixture of silver flakes and silver-coated copper flakes, a solvent, a cross-linking agent which cross-links with itself and with the functional groups of the organic binder and preferably a catalyst which accelerates cross-linking of the cross-linking agent and organic binder. Using such a paint formulation it has been found that thinner coatings can be used while still exceeding the properties needed for EMI/RFI shielding of housing for electronic components. A Theological additive which is an organic derivative of castor oil is preferably used to control the viscosity and spraying characteristics of the paint especially in a paint composition containing silver coated copper flakes. The conductive paint provides a sprayed coating which is durable, has low resistivity and is smooth and has both cohesive and adhesive strength. A method is also provided for forming EMI/RFI shielding on housings for electronic components and electronic components made using the method and paint composition of the invention. Another method is provided for making printing plates used to print a design on an article such as a beverage can. The printing plate is made by applying the conductive paint of the invention to a polymer imaged substrate such as a steel plate.

The present invention provides an improved method and materials for forming biodegradable containers that can hold food products in dry, damp or wet conditions and provides the biodegradable containers prepared according to the disclosed process. The containers are produced through the use of a pre-gelled starch suspension that is unique in its ability to form hydrated gels and to maintain this gel structure in the presence of many other types of materials and at low temperatures.