A composite thermoelectric material includes: a thermoelectric material of an intermetallic compound series; and a film that is coated over the whole or a part of the surface of the thermoelectric material and contains aluminum phosphate (AlPO.sub.4) as a main component. Such a composite thermoelectric material is obtained by: applying a coating liquid obtained by dispersing or dissolving aluminum phosphate (AlPO.sub.4) into a solvent over the surface of a thermoelectric material; drying the coating liquid and obtaining a precursor film; and firing the thermoelectric material over which the precursor film is formed.

A composite thermoelectric material includes: a thermoelectric material of an intermetallic compound series; and a film that is coated over the whole or a part of the surface of the thermoelectric material and contains aluminum phosphate (AlPO.sub.4) as a main component. Such a composite thermoelectric material is obtained by: applying a coating liquid obtained by dispersing or dissolving aluminum phosphate (AlPO.sub.4) into a solvent over the surface of a thermoelectric material; drying the coating liquid and obtaining a precursor film; and firing the thermoelectric material over which the precursor film is formed.

The method disclosed includes: a step (I) of preparing a dispersion liquid (S) including an aluminum compound (A); a step (II) of mixing the dispersion liquid (S) and a predetermined phosphorus compound (B) so as to prepare a coating liquid (U); a step (III) of applying the coating liquid (U) onto the base (X) so as to form a precursor layer of the layer (Y); and a step (IV) of subjecting the precursor layer to heat treatment at a temperature of 110 C. or more so as to form the layer (Y). The aluminum compound (A) can be formed by adding an acid to a solution including an aluminate. The number of moles (N.sub.M) of aluminum atoms derived from the aluminum compound (A) and the number of moles (N.sub.P) of phosphorus atoms derived from the phosphorus compound (B) satisfy 0.8(N.sub.M)/(N.sub.P)4.5.

The method disclosed includes: a step (I) of preparing a dispersion liquid (S) including an aluminum compound (A); a step (II) of mixing the dispersion liquid (S) and a predetermined phosphorus compound (B) so as to prepare a coating liquid (U); a step (III) of applying the coating liquid (U) onto the base (X) so as to form a precursor layer of the layer (Y); and a step (IV) of subjecting the precursor layer to heat treatment at a temperature of 110 C. or more so as to form the layer (Y). The aluminum compound (A) can be formed by adding an acid to a solution including an aluminate. The number of moles (N.sub.M) of aluminum atoms derived from the aluminum compound (A) and the number of moles (N.sub.P) of phosphorus atoms derived from the phosphorus compound (B) satisfy 0.8(N.sub.M)/(N.sub.P)4.5.

Metal silicates or phosphates are deposited on a heated substrate by the reaction of vapors of alkoxysilanols or alkylphosphates along with reactive metal amides, alkyls or alkoxides. For example, vapors of tris(tert-butoxy)silanol react with vapors of tetrakis(ethylmethylamido) hafnium to deposit hafnium silicate on surfaces heated to 300 C. The product film has a very uniform stoichiometry throughout the reactor. Similarly, vapors of diisopropylphosphate react with vapors of lithium bis(ethyldimethylsilyl)amide to deposit lithium phosphate films on substrates heated to 250 C. Supplying the vapors in alternating pulses produces these same compositions with a very uniform distribution of thickness and excellent step coverage.

Metal silicates or phosphates are deposited on a heated substrate by the reaction of vapors of alkoxysilanols or alkylphosphates along with reactive metal amides, alkyls or alkoxides. For example, vapors of tris(tert-butoxy)silanol react with vapors of tetrakis(ethylmethylamido) hafnium to deposit hafnium silicate on surfaces heated to 300 C. The product film has a very uniform stoichiometry throughout the reactor. Similarly, vapors of diisopropylphosphate react with vapors of lithium bis(ethyldimethylsilyl)amide to deposit lithium phosphate films on substrates heated to 250 C. Supplying the vapors in alternating pulses produces these same compositions with a very uniform distribution of thickness and excellent step coverage.

APs are made by binary condensation via base-to-acid or acid-to-base routes. In the base-to-acid route, an aluminum hydroxide slurry is added to phosphoric acid that reacts to produce an aluminum phosphate condensate. In the acid-to-base route, phosphoric acid is added to an aluminum hydroxide slurry that reacts to produce an aluminum phosphate condensate. In an alternative base-to-acid route, an acidic aluminum phosphate is first made by adding phosphoric acid to a first amount of aluminum hydroxide slurry, and such acidic aluminum phosphate is added to a remaining amount of aluminum hydroxide slurry to react and produce an aluminum phosphate condensate. The reactions can be controlled to form an in-situ layered aluminum phosphate. So-formed APs can be amorphous, crystalline, or a combination thereof, and have low oil absorption and surface area, making them particularly useful in such end-use applications as extender pigments in coating compositions, replacing up to 70 wt % of TiO.sub.2.

APs are made by binary condensation via base-to-acid or acid-to-base routes. In the base-to-acid route, an aluminum hydroxide slurry is added to phosphoric acid that reacts to produce an aluminum phosphate condensate. In the acid-to-base route, phosphoric acid is added to an aluminum hydroxide slurry that reacts to produce an aluminum phosphate condensate. In an alternative base-to-acid route, an acidic aluminum phosphate is first made by adding phosphoric acid to a first amount of aluminum hydroxide slurry, and such acidic aluminum phosphate is added to a remaining amount of aluminum hydroxide slurry to react and produce an aluminum phosphate condensate. The reactions can be controlled to form an in-situ layered aluminum phosphate. So-formed APs can be amorphous, crystalline, or a combination thereof, and have low oil absorption and surface area, making them particularly useful in such end-use applications as extender pigments in coating compositions, replacing up to 70 wt % of TiO.sub.2.

Anticorrosive coating compositions comprise a binding polymer and an amorphous aluminum phosphate corrosion inhibiting pigment dispersed therein. The coating composition comprises 1 to 25 percent by weight aluminum phosphate. The binding polymer can include solvent-borne polymers, water-borne polymers, solventless polymers, and combinations thereof. The aluminum phosphate is made by combining an aluminum source with a phosphorous source to form an amorphous aluminum phosphate solid condensate. The coating composition is specially engineered to provide a controlled delivery of phosphate anions of 50 to 500 ppm, and has a total solubles content of less than 1500 ppm. The amorphous aluminum phosphate is preferably free of alkali metals and alkaline earth metals. The amorphous aluminum phosphate has an oil absorption of less than 50, and a surface area of less than about 20 m.sup.2/g, The coating composition has a water adsorption potential of up to 25% by weight water.

Anticorrosive coating compositions comprise a binding polymer and an amorphous aluminum phosphate corrosion inhibiting pigment dispersed therein. The coating composition comprises 1 to 25 percent by weight aluminum phosphate. The binding polymer can include solvent-borne polymers, water-borne polymers, solventless polymers, and combinations thereof. The aluminum phosphate is made by combining an aluminum source with a phosphorous source to form an amorphous aluminum phosphate solid condensate. The coating composition is specially engineered to provide a controlled delivery of phosphate anions of 50 to 500 ppm, and has a total solubles content of less than 1500 ppm. The amorphous aluminum phosphate is preferably free of alkali metals and alkaline earth metals. The amorphous aluminum phosphate has an oil absorption of less than 50, and a surface area of less than about 20 m.sup.2/g, The coating composition has a water adsorption potential of up to 25% by weight water.