Phosphate glues

As was mentioned in Chapter 2, attempts to reduce oxides in forming phosphate glues were reported in the early literature. For example, Fedorov et al. [1] used a mixture of copper oxide (CuO) and metallic copper and developed a phosphate bonding agent for metals, where metal copper must have acted as the reductant. They also cite formation of phosphate glues with Zr02 and with CaZr03 in combination with Ni, Cr, and Ti. 

Dicyandiamide reduces the viscosity of certain coUoidal solutions. This property is of commercial significance ia the manufacture of glues and adhesives, ia the coating and sizing of paper and textiles, and ia the conditioning of phosphate drilling muds (see Petroleum). This action may prove useful ia other appHcations where control of viscosity is important (54). 

Anecdotal cases of contact dermatitis from triphenyl phosphate have been reported. A positive patch test to 5% triphenyl phosphate occurred in a hobby worker who worked with a plastic glue and had symptoms of psoriasiform dermatitis of both palms. 

In Franco, a considerable quantity of glue is made from hones, which are digested in hydrochloric acid, for the purpose of removing the phosphate of lime. 

Commercial casein is usually manufactured from skim milk by precipitating the casein through acidification or rennet coagulation. Casein exists in milk as a calcium caseinate-calcium phosphate complex. When acid is added, the complex is dissociated, and at pH 4.6, the isoelectric point of casein, maximum precipitation occurs. Relatively little commercial casein is produced in the United States, but imports amounted to well over 150 million lb in 1981 (USDA 1981C). Casein is widely used in food products as a protein supplement. Industrial uses include paper coatings, glues, plastics and artificial fibers. Casein is typed according to the process used to precipitate it from milk, such as hydrochloric acid casein, sulfuric acid casein, lactic acid casein, coprecipitated casein, rennet casein, and low-viscosity casein. Differences... 

Drum dryers potatoes, cereals, buttermilk, skim milk, dextrins, yeasts, instant oat meal, polyacylamides, sodium benzoate, propionates, acetates, phosphates, chelates, aluminum oxide, m-disulfuric acid, barium sulfate, calcium acetate-arsenate-carbonate-hydrate-phosphate, caustic, ferrous sulfate, glue, lead arsenate, sodium benzene sulfonate, and sodium chloride... 

When the compounded adhesives are used in the mills, they are normally mixed with various alkaline materials and water to form the glue. The alkaline materials may be combinations of caustic soda, lime, soda ash, sodium silicate, and trisodium phosphate to obtain the right viscosity, working life, bond... 

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