This disclosure relates to phosphate coatings that inhibit corrosion of metals, specifically coatings comprising acidic phosphate and alkaline metal oxide/hydroxide components. In one particular embodiment, phosphate-based coating formulations that reduce or eliminate corrosion of steel and other metals are disclosed. In other embodiments, methods for coating steel surfaces with acidic phosphate and alkaline metal oxide/hydroxide components to reduce or eliminate corrosion of the metal surfaces are disclosed.

Inorganic phosphate corrosion resistant coatings

This disclosure relates to inorganic coatings suitable for fire protection, fire retardancy, and articles comprising same. Specifically, the disclosure relates to the manufacture and use of inorganic phosphate-based coating formulations for fire protection, preventing or reducing fire propagation, and for heat management.

Fire protection compositions, methods, and articles

The invention is related to a premixed putty calcium phosphate composition comprising at least two calcium phosphate minerals, at least one reaction retarding agent, at least one binding agent, at least one sodium phosphate, and at least one nonaqueous extender, wherein one of said at least two calcium phosphate minerals contains a stabilizing agent.

Injectable calcium phosphate cement

The invention is related to a calcium phosphate composition comprising at least one calcium phosphate mineral, at least one reaction retarding agent, at least one binding agent, and at least one sodium phosphate compound, and a calcium phosphate cement comprising a powdered first component comprising stabilized dicalcium phosphate dihydrate containing from about 10 ppm to about 60 ppm of magnesium, a powdered second component comprising a calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrate, and a liquid third component comprising water.

Calcium phosphate cement

The present invention relates to anti-corrosive particles based on inorganic oxide products such as silica or alumina modified with polyvalent metal cations optionally comprising anions of weak acids which may be inorganic or organic in nature and their conjugate species. In particular, the present invention is concerned with anti- corrosive pigment particles comprising inorganic oxides or mixtures of inorganic oxides displaying mesoporosity and/or macroporosity such that the average pore size, averaged over the mixture of inorganic oxides where more than one oxide is involved is greater than 2 nm and the average pore volume is greater than 0.2 ml/g. The present invention is also related to methods of making such particles and to anti- corrosive compositions made with them. The present invention further relates to articles to which the anti-corrosive compositions have been applied.

Anti-corrosive particles

For the preparation of dicalcium phosphate dihydrate stabilized with dimagnesium phosphate trihydrate and sodium pyrophosphate, an aqueous suspension of calcium carbonate is introduced into a reactor and recirculated by pumping through a high-speed mixer at 3,500 to 8,000 rpm which is in flow connection with the lower and upper portion of the reactor. Into the mixer an amount of phosphoric acid is introduced which is at least sufficient for the quantitative formation of dicalcium phosphate dihydrate and then an oxygen-containing magnesium compound is introduced into the reactor. Finally, lime milk is metered into the reactor up to a maximum pH of 6.9, before the sodium pyrophosphate is added to the reactor. The resulting suspension which has a stabilized dicalcium phosphate dihydrate content of 20 to 33% by weight is spray-dried. An apparatus for carrying out the process comprises besides a stirred reactor 1 two stirrer-equipped slurry containers (6, 7) and an intermediate container 16 from which a line 17 leads into a spray tower 18 where it ends above an atomizer wheel 19. The spray tower 18 is also the end point for hot air lines 20 and is in flow connection with a filter 22. The bottom of filter 22 is the starting point for a product line 24 via which highly adsorbent dicalcium phosphate dihydrate can be withdrawn.

Process for the preparation of dicalcium phosphate

In order to prepare dicalcium phosphate dihydrate which has been stabilised by means of dimagnesium phosphate trihydrate and sodium pyrophosphate, an aqueous suspension of calcium carbonate is introduced into a reactor and pumped in a circuit by a high-speed mixer which is connected by flow to the lower and upper parts of the reactor, at a speed of 3500 to 8000 rpm. An amount of phosphoric acid at least sufficient for quantitative formation of dicalcium phosphate dihydrate is introduced into the mixer, and an oxygen-containing magnesium compound is subsequently introduced into the reactor. Finally, milk of lime is metered into the reactor to a maximum pH of 6.9, before sodium pyrophosphate is introduced into the reactor. The resultant suspension, containing from 20 to 33% by weight of stabilised dicalcium phosphate dihydrate, is spray-dried. … An installation for carrying out the process comprises, in addition to a stirred reactor 1, two slurry tanks (6, 7) provided with stirrers and an intermediate tank 16, from which a line 17 leads to a spray tower 18 and terminates within the spray tower 18 above an atomiser wheel 19. Hot-air lines 20 run into the spray tower 18. The spray tower 18 is connected with respect to flow to a filter 22. A product line 24, via which highly adsorptive dicalcium phosphate dihydrate can be removed, leaves the base of the filter 22.

Franz-Josef Dipl Chem Dr Dany

Papers

Process for the preparation of dicalcium phosphate

Process and installation for the preparation of calcium hydrogen phosphate