Diphenyl was commercially produced for the first time by Swann Research, Inc., at Anniston, Ala., about 1928. The demand for it as a heat-transfer medium resulted in large scale output. Later it was found that certain of the chlorinated compounds of diphenyl possess valuable resin properties. The Aroclors range from a clear mobile oily liquid to an amber colored transparent solid. They are thermoplastic, do not polymerize or oxidize, and are therefore nondrying. They may be dissolved in varnish oils, such as tung oil and linseed oil, to give varnishes which are resistant to alkali and water. The diphenyl resins are good adhesives on metal and glass and give strong joints between such surfaces. They have a high dielectric constant, resistivity, and a low power factor. Their chief use is in wire insulation. The domestic production of chlorinated diphenyls is, at present, solely by the Monsanto Chemical Company, St. Louis, Mo. Furfural resins. Large scale commercial production of furfural, an aldehyde obtained from oat hulls and other farm waste, has made it available for synthetic resin manufacture. Tar-acid furfural resins possess certain outstanding properties, such as great dimensional accuracy, great reaction speed to the infusible solid stage, and unusual strength and toughness. They are available in dark shades only. Printing plates as large as those of metropolitan daily papers are molded from them as are radio tube bases, all sorts of electrical parts, and machined parts requiring great dimensional accuracy. Other uses are in abrasive wheels, varnishes, and adhesives. Probably the largest domestic maker of furfural resins is the Durite Plastics Division of Stokes and Smith Company, Philadelphia, Pa. Resins from sugar. Many attempts have been made to utilize sugar as a raw material for synthetic resins. United States Patent No. 1,949,831, dated March 6, 1934, claims a process for the manufacture of molding compounds by condensing saccharide with aldehydes and urea. Pure sucrose yields a clear, colorless, nonresilient resin, while molasses and cane sugar give dark-colored resins. The trade name Sakaloid is used to designate certain of these resins; there is, however, no known domestic production. Sucrolite is the trade name of a brand of resins from sugar produced in Europe. Sulphonamide resins. The sulphonamide resins were developed from para toluenesulphonamide, a byproduct obtained in the manufacture of saccharin (synthetic sweetening agent). Para toluenesulphonamide, condensed with formaldehyde or other aldehyde, forms a viscous mass which, on heating, is converted to a hard colorless resin. Such resins are compatible with cellulose acetate or nitrocellulose in lacquers, the combination yielding clear, colorless lacquers of good gloss and adhesion. Other possible uses are as an adhesive in safety glass, in certain molding compositions, in insulating materials, and to deluster artificial silk.