THE CHEMICAL A N D CHEMICAL PROCESS INDUSTRIES Ε. Ε. McSWEENEY, Battelle Memorial Institute, Columbus, Ohio
Plastics
Field w a s m a r k e d by increasing diversity of products . . . phenolics were hardest hit by first-of-the-year slump
JLIIVERSIFICATION might be said to have been the keynote in plastics in 1952. Many chemical companies have viewed the plastics field as an increasingly im portant raw material market and an ex cellent field for diversification. There were several announcements of the entry of companies into new fields of plastic pro duction. In fact, most major chemical com panies have products which go directly or indirectly into the plastics market. Recently, this diversification trend has led plastic manufacturers to seek markets in practically every other field of tech nology. This is best illustrated by the an nouncement about the first of the year of the application or poiyeleciroiytes as soil conditioners. Monsanto's original disclos ure of the application of sodium polyacrylate derived from polyacrylonitrile precipi tated a race to get materials on the market for the summer gardener. This resulted in the sale of a variety of materials by 28 companies with Monsanto's own material being not the original polyacrylate, but a Uinyl acetate-maleic anhydride copolymer. The future of soil conditioners and the potential consumption of resins in this field is still a matter of speculation with one of the major considerations being cost, which is presently as much as $3000 per acre. This development also brought to life the fact that a very similar application of polyacrylate additives for oil well drilling muds has been under way by American Cyanamid for several years. New Use for An Old Product Another striking example of a new use for a now somewhat old plastic, poly ethylene, was the announcement of chlorosulfonated polyethylene which is a promising new elastomer with outstand ing resistance to ozone as well as heat and abrasion. Particularly intriguing are its good physical properties without rein forcement with carbon black. Tire treads of all colors now are possible but not eco VOLUME
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nomical. High cost of the material will probably limit its use to applications where its special properties are required, but it does indicate still another applica tion for this very versatile plastic material. This is still another reason to expect the polyethylene supply to continue to run behind the demand even though the present producers have again announced plans for increased capacity and two new producers have announced their entry into the field although one is limited at present to low molecular weight wax products. It is also well known that several other po tential producers are seriously considering entering the field so that the announceηi£n«. Οχ. ΟΠΘ or ÔVO scn_iîj.zonSj. onirics can be expected during the next year. Interest in plastic pipe considerably intensified with several materials competing for this market. A number of thermoplastics including cellulose acetate butyrate, polyethylene, butadiene copolymers, and polyvinyl and polyvinylidene chlorides have been fabricated by extrusion to gi\e a wide variety of products ranging from continuous lengths of flexible hose to sections of rigid pipe. In the thermosetting field, the older phenolics and the polyesters are both finding increasing use. Noteworthy was the development of a continuous method of producing glass fiber-reinforced polyester pipe. This material is being rather critically evaluated for Navy uses with the object of replacing critical materials for corrosion-resistant pipe. A limited amount is also going into small oil well casings. The polyester glass fiber materials were in the news quite frequently. Early in the year the development of a one-piece glass fiber sports car body was announced with the subsequent news that Kaiser would build at least 10OO such cars. Lightweight fiber glass tanks are also in commercial production. Most popular size is about 1000 gallons for tank wagons, but larger stationary tanks with more than 100,000-gallon capacity have been made. In addition to being lighter than steel,
JANUARY
5,
1953
they are résistant to corrosive chemicals. An older use for glass laminates, body armor, received considerable attention with the announcement that both glass and flexible nylon laminates have been thoroughly evaluated in Korea. Initial reports were very favorable. Temperature limitations of polyesters were considerably lessened with the development of a number of resins using trial! yl cyanurate, which retain appreciable strength after exposures of as long as 24 hours at 500° F. A low-pressure silicone resin is also available for this field. Production.wise, the first half of 1952 was very disappointing. The sales of most ï"iïfisHc*5
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capacity. However, since July, there has been a steady increase so that the total for the year should be close to that for 1951. The slack in demand is undoubtedly the reason that plastic prices in general remained fairly steady and. in at least one case, that of the liquid ureas, reached what is possibly an all-time low of about 13 cents a pound on a solids basis. Continuous Growth Despite the rather unsteady market, there were several predictions of future expansion which indicate a continuous growth for trie industry. For example, the Defense Production Administration's goal for 1955 is 4.6 billion pounds, about double the current production. Even more optimistic was the report of the President's Materials Policy Commission which predicted a production of 22 billion pounds for 1975 which represents about a 10-fold increase. Since much of this predicted expansion is expected in resins based on benzene (for example, polystyrene and phenolics to over 2 billion pounds each), the demand for benzene will become an increasingly serious factor. Therefore, the current trend to vinyltoluene for some applications is expected to continue. This material is now in commercial production but little information is available on specific uses. 37
C&EN'S ANNUAL REVIEW OF DEVELOPMENTS IN Likewise, considerable interest is b e i n g shown in t h e conversion of xylenes to trie t h r e e isomeric phthalic acids. HTerephthalic acid from p-xylene has, of course, b e e n m a d e for several years as a r a w material for t h e polyester fiber, Dacron; a second producer, at least, is n o w in t r i e field. T h e problem of utilizing isophthalic, of course, remains. However, first reports of its utility in alkyds, polyesters, and piasticizers were very encouraging and its u s e seems assured when it becomes available. Another expected development, which is apparently quietly under w a y , is the use of mixed phthalic acids for plasticizers. Possible production of tererphthalic acid from butylène was also pointed out in some German work o n reactions catalyzed with lithium aluminum hydride, In this process, yields of over 50% 73-xylene are obtained w i t h ethyl benzene a n d o-xylene a s t h e only other products. Since separation of these is much easier t h a n separating t h e three isomeric xylenes, this process, in which the hydride is a "true" catalyst and not consumed, has r e a l commercial possibilities. In addition to t h e increasing d e m a n d for t h e terephthalic polyester fibers, announcement was m a d e late in the year t h a t a full-scale p l a n t for t h e production of film from this same plastic will be started early in 1953. Experimental production of this Mylar film during the past year has shown it t o have outstanding strength characteristics and excellent stability even at extremes of temperature, i t s most important initial application wilî b e in t h e electrical field where high strength, stability, water resistance, and excellent electrical properties will be needed. Later, uses are envisioned in t a p e s of all types including sound record-
copolymers. These products s h o u l d be particularly useful as potting compounds, coatings, a n d sealants. Nylon expansion was also in the news a n d t h e long-hinted entrance of Allied Chemical i n t o t h e field with a caprolactam-type material was announced.
ing a n d in packaging a n d even for storm w i n d o w s where its excellent clarity and toughness make it u n i q u e among films. Polyvinyl chloride production, although it d i p p e d somewhat toward midyear, is again o n the increase with a t least one new monomer producer as well as several actual o r potential new polymer producers. Particularly noteworthy were t h e introduction of a number of improved polymers and copolymers a n d a n intensification of interest in fabrication of rigid material. There are also indications t h a t vinyl c o polymers may become an i m p o r t a n t ingredient of latex paints and displace some of the styrene resins n o w used. Improved styrene copolymers a n d " a l loys" a r e also one of t h e newest developments a n d have e x t e n d e d the use of these materials to a n u m b e r of fairly critical items w h e r e their improved toughness w a s highly essential, such a s refrigerator door liners weighing as m u c h as seven p o u n d s and b a t t e r y cases weighing 14 p o u n d s . The increase in size of injection m o l d i n g machines was a p p a r e n t l y not as spectacular as in other recent years, but capacities of at least 375 ounces a r e now available a n d plans for increasingly larger moldings are b e i n g m a d e . In spite of a price increase, the epoxy resins continue to gain to the point where production for t h e y e a r w a s p r o b a b l y about 12 million p o u n d s . Trie main uses for t h e s e versatile resins remain i n coatings, adhesives, a n d potting compounds, but t h e r e is increased interest in t h e m as laminating resins with glass fiber so t h a t this c o u l d become a major u s e . Considerable interest is being shown in blends of epoxies and liquid Thiokol polymers. T h e mercaptan end groups in t h e latter react with t h e epoxide group to give " t r u e "
Phenolics The supply of phenolic resins was greatly increased b y one n e w phenol plant which boosted U. S. production b y 60 million pounds, a n increase of 1 5 to 2 0 % . Hercules also has entered the field w i t h an oxidation process starting with isopropylbenzene. Ironically, the phenolics were hardest hit b y t h e first-of-the-year slump w i t h production of casting, laminating, a n d molding resins d o w n to 11.2 million pounds in July in contrast to 20 million pounds in October, 1 9 5 1 . On t h e utilization side, there w e r e no notable advances. The expected increase i n consumption in the foundry field, especially i n t h e relatively n e w shell-molding process, has been considerably b e h i n d expectations. Part of the difficulty c a n be attributed t o the tooling that h a s b e e n required to h a n d l e the resin-sand combination adequately in the foundry. A numb e r of designs h a v e b e e n developed and a r e undergoing production shakedowns. However, long-range prospects h e r e are still excellent and account for a fair share of the President's Materials Policy Commission—predicted consumption of 1950 million pounds of phenol in phenolic resins for the year 1975. T h e r e are some indications t h a t application of phenolic resins in t h e foundry may b e eased by prccoating of sand with t h e liquid resin prior to drying s o that the foundryman c a n buy sand ready for immediate use.
FOSTER DEE 3NELL, Foster D. Snell, inc., New York, Ν. Υ.
Soaps arid Syndets . . .
Increased syndet research
may explain the 5 0 % foothold in household sales gained by syndets last y e a r S Y N T H E T I C detergents or syndets con tinued t h e same steady growth in pro duction in 1952 as in 1 9 5 1 , heading to w a r d a predicted 2 billion pounds in 1954 or 1955. T h e proportional increase in each case, over t h e previous year, was about 2 0 % . Soap, o n the other h a n d , de
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clined about 6 % a s compared with a 2 0 % decline in 1951 from the previous year. The final production figures for solid soap and syndets for 1951 can be com pared with estimates for 1952, which are based on figures reported for the first nine months.
CHEMICAL
1951 1952 ( millions of pounds ) Solid soap 2444 2295 Syndets 1434 1717 Total 3878 4012 The increased total production in 1952
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ENGINEERING
NEWS
