•
silicone base with special flake pigment.
CHEMICALS is reddish-brown, and is priced at 4 5 cents per pound. C 2
Choose Your Size Rohm & Haas is now offering a com of ion exchange resins de veloped specifically for chromato graphic analyses. Although chemically identical with its standard- and ana lytical-grade Amberlite ion exchange resins, the new series, CG Series^ is said to offer the advantage of optiiraum particle size for most chromatographic uses. Now the analyst has a choi of two particle sizes: T y p e I ranges between 1 0 0 and 2 0 0 mesh (dry); Type Π passes 200 mesh (dry). T h e resins are offered in the same classificatioEn as t h e Amberlite resins—strongly basic and weakly basic anion exchangers, and strongly acidic and weakly acidic cation exchangers. The larger particle size i s said t o allow reasonably rapid flow rates and separates materials with appreciably different chemical properties b y a c o m bination of ion exchange a n d adsorp tion. Type II resin, with the siraaller particle size and resultant greater sur face area, produces a greater lute o f reaction. Rohm and Haas says that flow rate over Type II resins is s o m e what restricted, but materials closely related chemically are still sh_arpry separated. C1 pj.CcC s e *
Carbon Paper Wax A series of petroleum macrocrystal line waxes, developed by Bareco Wax, imparts excellent flow properties t o car bon paper inks, says the company D e veloped specifically for this use, t h e new waxes were prepared b y the modi fication of macrocrystalline wax, They will be marketed by Bareco a_s W B Wax. Inks incorporating the waxes are nonthixotropic and have l o w viscosity, when properly formulated, says com pany. T h e inks also have zero yield value even under high pigmeat: load ing. In addition, the W B Waxes are said to b e good solvents for the basic dyes, giving full tinctorial strength, of the toner. Aging tests have also shown that the waxes have good oil retention; adjacent paper remained unspotted during such tests. This feature should niakze them particularly suitable for u s e in specialty carbon papers for one-time use, says company. One member of the series, now in production, is W B - 2 Wax. It has a melting point of about Σ85° F., 4950
C&EN
OCT.
8. 19 56
• Coating introduced by The Thomas Co., resists sticking of such materials as concrete, clay, lime, and snow to equipment. Coating is called Powerfilm MRC. C3 • Jarrell-Ash is serving as distributor for rare earths and rare earth salts produced b y Johnson, Matthey & Co., London. T h e compounds are offered in various grades, ranging from purity as high as 99.99% down to lower grades. C4 • Phthalate ester developed by BrownAllen Chemicals compares favorably with more expensive D O P in vinyl formulations, says company. Called Polycon # 4 0 , the compound's features fit it for u s e in extrusion compounds and also for use for coated fabrics, slush and dip moldings, and wire and cable covering, says company. C5 • Two liquid defoamers for the paper industry have been developed b y Witco Chemical. Dubbed Witco Defoamers 2 A and 3, the compounds are nonionic surface active products which h e l p to produce a finished paper free from air voids. Defoamer 2A is also said t o be effective in scrap paper de-inking proc esses, while Defoamer 3 in particular is a good leveling agent for starch and proteinaceous adhesive-type coating colors. C6 • Sapon Laboratories is offering methyl dimethoxyacetate in laboratory quanti ties. The compound can be condensed in high yield with aliphatic esters; the product can then be hydrolyzed to α-keto acetals which have use in phar maceutical research, says company. C7 • Curing a g e n t for epoxy resins, re cently developed by Smooth-Ôn, is dubbed Sonite N o . 41. Compound is said to b e low viscosity liquid that mixes readily with liquid epoxy resins at room temperature. It also gives long pot life. The compound is particularly adaptable, company says, for potting or encapsulating electrical components. C 8 ^Aluminum ραίπτ capable uf withstanding temperatures u p t o 1700° F . without blistering or burning is offered by Chem Industrial. Termed C-I Ex tra High, paint is composed of a clear
aluminum C9
)> Liquid rubber paint by Adhesive Products is said to h a v e excellent ad hesion to metal, wood, plastics, and concrete. Galled Anco. paint dries to a continuous rubber film which is re sistant t o oil, gasoline, and many other solvents. C 10 • Epoxy resin, Epi-Rez 507, offered by Jones-Dabney, was developed t o nil growing need for flexible epoxy compo sitions. The compound has a viscosity of from 4 5 0 to 650 cps., specific grav ity of 1.13 to 1.15. Its percentage of hydrolyzable chlorine is 0.15 maximum. C11 • Automotive paint developed by Martin-Senour Paint allows two coats to b e applied in immediate succession, company says. Paint is trade named Dythol. C12 • Series of preconditioned vinyl sili cone rubber compounds are commer cially available from Union Carbide and Carbon. Designated K-1044R, K-1045R, K-1046R, K-1047R, and K-1048R, compounds are said to meet toughest aeronautical specifications for high temperature applications. Other features include high tear, high elonga tion, tensile strength of over 800 lb. per sq. in., low compression set, good oil resistance, l o w moisture absorption, good drv and wet dielectric properties. C13 • Cuprous chloride in commercial quantities is now offered by Metalsalt Chemicals. Company says compound is of high grade, especially designed for use in manufacture of acrylonitrile, phthalacyanine pigments, and in other catalytic applications. C 14 • N e w plastics material, Teflon 100-X, developed b y Du Pontes polychemicals department is now being evaluated as a supplement to company's line of Teflon tetrafluoroethylene resins. D e pending outcome on field tests, com pany will decide after first of year whether to < produce commercially. N e w product, which differs somewhat from conventional Teflon in composi tion (both, however, have saturated structures consisting entirely of fluorine and carbon), approaches heat and chemical resistance of conventional Teflon but has melt viscosity low enough to permit extrusion in standard equipment, company says. C 15
J
I
i
Further useful information on keyed Chemîcai îferm ΠΪΘΪΪ-Honed îs readily available . . .
j
Use handy coupon on page 4956 φ
-*J* |
