CHEMICALS
ACE
New Text New Text New Text For low flow rates from lOcc/min. to40,000cc/min. for gas,and O.lcc/min. to 1,4O0cc/min. for water. A Compact a n d SelfC o n t a i n e d Flow Test Kit. Safe Pressure rate 100 lbs.Maximum corrosion resistance. F l o a t and T u b e R e placements are Guaranteed Interchangeable. Packed in A t t r a c t i v e Wooden Case. Available from Stock in Vineland For complete d a t a and prices - Write Department ARK-B Alto in stock at our MIDWESTERN DIVISION Louisville, Ky.
chemical-loaded materials, developed a concept of using the man-made zeolites for "putting things together." Molecular sieves are literally "cages," or cells, formed upon dehydration of crystalline alumino-silicates. O'Connor explains that, unlike other zeolites, these structures do not collapse when the water of hydration is driven off. Small, face-centered openings in the cubic surface of the cage admit molecules having a critical diameter of about 10 A. These lead into a chamber somewhat larger than 20 A. in diameter. Adsorption forces are particularly strong there, since they surround this hollow core. And they are highly attractive to polar molecules. Surface forces on the outside are relatively weaker, retain no more t h a n a monomolecular layer of adsorbent. T h e dehydrated sieves a r e loaded to 10 or 1 5 % by weight of adsorbent, can go u p to 307c, They are stable at temperatures of 250° F. or higher, O'Connor says, except in atmospheres of high humidity. (Under humid conditions, he explains, water tends to replace other adsorbed molecules in the cage.) The loaded sieves, white or lightcolored, are designed to release a the adsorbed agent at normal curing temperatures. Residual material from the sieve skeletons causes no perceptible change in elastomer or resin properties, O'Connor states. • Rigid Plastisols, Too. In addition to its use for one-step postcure of large masses of silicone rubber, loaded sieve CW-2015 ( 1 5 % by weight of DTBP) acts as a latent curing aid for vinyl plastisols by polymerizing the plasticizer, polyethylene glycol dimethacrylate. Normally a two-package system is needed for this type of curing. Latent neoprene accelerators are sieves loaded with 10% by weight of catechol ( C W - 3 0 1 0 ) and with 2 0 % diethyl thiourea ( C W - 3 1 2 0 ) . Latent secondary accelerators for other .rubbers contain lof< piped dine (CW1015) or the same proportion of di-nbutylamine ( C W M 1 1 5 ) . C1
New Butene Source
ACE GLASS INCORPORATED
High purity butene concentrates now a v a i l a b l e in commercial quantities
^ ^ y i N E L A N D : 4 NEW JERSEY •))
-' •;
Midwest
^^^OUISVILLE/KY.-^Box 996
6 4
C&EN
MAY
2 6,
1958
7
D U T A D I K N K makers, who a r e now able to supply synthetic rubber a n d chemical
demands with no difficult)', have turned part of their efforts to producing other chemical raw materials from C 4 hydrocarbons. O n e such company, Texas Butadiene & Chemical, now has high purity 2-butene and 1-butene concentrates in commercial quantities. TB&C says its 2-butene is available in 96r'( minimum concentration, free of isobutylene, with less than 0.5% 1-butene, and less than 1% butadiene. T h e remainder is ;i-butane. T h e 1-butene concentrate has a 6 0 % minimum 1-butene content. T h e rest of the concentrate is practically all butanes except for isobutylene in concentrations up to 5% . Until now, normal butylenes have been commercially available only as mixed isomers—mainly from refinery catalytic cracking operations. These streams contain a large amount of butanes and are mostly used in processes where both isomers yield the same product, such as butadiene and secbutanol. For these existing uses, the high purity 2-butene stream will aid processors b y virtually eliminating the large amount of nonreactive butanes which their equipment has been required to handle, says TB&C. Perhaps t h e most interesting possibility for the separated n-butylene isomers is their use in reactions where each gives a different product. In such cases, mixed butylene feedstocks would yield a mixture of products that might be difficult to separate or, if separated, one might have no market. C2
New Latex-High Gloss On-machine coaters turn out p a p e r s like c o a t e d ones
may cast-
K OPPERS held a double debut at its open house at Kobuta just before the Technical Association of the Pulp and Paper Industry's coating conference at Bedford, Pa. The principals: a new styrene-butadiene ( 8 0 / 2 0 ) binder; a versatile paper coater. High styrene content is probably the key to good gloss properties, and the new paper latex, dubbed Dylex KCD-85, is the first commercial latex containing over 7 0 S styrene that is a film former at room temperature and is adhesive, Koppers says. Furthermore, (Continued
o)} -page 136)
