U.S.I. Has Acrylonitrile Dimer Intermediate acts as a vinyl monomer and is useful in cyanoalkylation reactions U.S.I. Chemicals claims it can dimerize acrylonitrile catalytically; until now, only thermal dimerization routes would work on a commercial scale. The National Distillers & Chemical division now makes the dimer, methylene glutaronitrile 2,4-dicyanobutene-1), in a pilot plant at Cincinnati, Ohio. U.S.I, hopes the dimer can compete, at least on a functional group basis, with acrylonitrile and acetonitrile—for example, in acrylonitrile-butadiene-styrene resins and acrylic fibers. Furthermore, many derivatives of the dimer can be made by hydrogénation and subsequent hydrolysis or other reactions. The dimer marks U.S.I/s re-entrance into the specialty intermediates market. A decade ago, the company planned to make isosebacic acid, a mixture of three C-10 dicarboxylic acids. The product held promise for the plasticizer market, among others. Price Factor. Price is a factor with the new dimer. As a development chemical, it will sell for between $1.00 and $1.50 a pound. With markets in the 5 to 10 million lb.-per-year range, the dimer might sell for 50 cents a pound and, with higher volume, even lower. By comparison, acrylonitrile now lists for 17.5 cents a pound. Last year, 594 million lb. of acrylonitrile were made in the U.S. Methylene glutaronitrile is a colorless liquid which boils at 103° C. at 5 mm. It is soluble in aromatic and polar organic solvents but not in aliphatic or aiicyciic hydrocarbons. The compound's structure is viewed more properly as a-cyanoethylacrylonitrile. A dimer hydrogenates sequentially at its terminal double bond, then at one or both of its nitrile groups. U.S.I, sees the most interest in the dimer's possibilities to make polymers and copolymers. A significant prospect lies in new types of modified acrylic fibers. For example, fibers modified with methyl glutaronitrile might be melt spun rather than solution spun (present practice with acrylic fibers) using solvents such as dimethyl formamide or dimethyl acetamide. This would be important to some fibers producers, since the other
major noncellulosic fibers (nylon, polyester, olefin) are melt spun. Thus, acrylic could be added to some plants, particularly those of small producers who buy resin to spin fiber. Market targets are vast. Acrylic fiber production was 288 million lb. in 1964. U.S.I, plans to study the acrylic fiber prospects more thoroughly, and, at this time, development points to the dimer's use in conjunction with acrylonitrile. A major question is what the dimer's use would do to improve fiber properties such as hand and dyeability. Interesting, too, is potential use as a co- or terpolymer with styrene and/or butadiene to make thermoplastics such as styrene-acrylonitrile ( SAN ), acrylonitrile-butadiene-styrene (ABS), or elastomers such as nitrile rubber. Current nitrile rubbers have high oil resistance. But, U.S.I, says, beyond 40% acrylonitrile, flexibility is reduced. The dimer overcomes this problem. In thermoplastics, methylene glutaronitrile could polymerize to ABStype products which U.S.I, calls A 2 BS. Some 110 million lb. of ABS resins were made last year with projections for 1970 ranging between 350 million and 400 million lb. But the dimer's price could limit use here, although in some cases, plastics with specific property advantages such as
changes in solubility, molecular weight, or softening point might be possible. Urethane Prospects. Complete hydrogénation of methylene glutaronitrile using nickel or cobalt catalysts yields 2-methyl pentamethylenediamine, a potentially competitive product for hexamethylenediamine. The latter is used to make nylon 66. Hence, the new diamine has possibilities here. But there are many polyamides and only nylon 66 and nylon 6 (from caprolactam) have reached high-volume markets. Last year, 805 million lb. of nylon (all forms) were made. Another possibility for the new diamine is in isocyanates to make polyurethanes. The diamine reacts with phosgene to make an aliphatic diisocyanate which might fit into the polyurethane field. Nearly 300 million lb. of isocyanates were made last year, about 90(/c aromatic—for example, toluene diisocyanate. About 10% of the market is aliphatic monoisocyanates such as methyl monisocyanate. A very small market exists for aliphatic diisocyanates such as hexamethylene diisocyanate. One reason is the virtually nonexistent merchant market for hexamethylenediamine. U.S.I, feels that a domestic source of the new diamine could spur interest and growth of aliphatic diisocyanates in the polyurethane field. U.S.I, sees several other possibilities for methylene glutaronitrile or its derivatives: thermosetting resins for coatings, acidulants, solvents, and nicotinic acid, for example. This is because the material is a new vinyl monomer as well as a useful cyano-
Dimer Opens Route to Other Intermediates
