Bond Makes the Difference - C&EN Global Enterprise - ACS Publications


Others actively interested in addition to Riegel and Du Pont include: Great ... in the paper to attain optimum physical properties, says Du Pont's Joh...
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CHEMICALS Bond Makes the Difference Resins a n d thermoplastic Fibers prove more practi­ cal than solvents t o bond synthetic fiber papers S Y N T H E T I C FIBER PAPERS have moved

Only Aori©iirf3 2™sfstem Fractionation can supply you with such a complete line of highest purity fatty acids tailored for ester manufacturing. O n l y Armour uses fractional distillation a n d solvent crystal­ lization t o produce a complete line of uniform N e o - F a t fatty a c i d s offering single components i n purities as h i g h a s 9 6 % . Yet you pay no premium in price* A d v a n t a g e s such a s t h e s e m a k e Armour your one b e s t source for all f a t t y acids. I n t h e list b e ­ l o w , you'll find the specific Armour N e o - F a t s that will help y o u produce t h e finest esters a t t h e lowest cost. Write us for s a m p l e s and information· H I

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PRESSED STEARIC ACIDS Neo-Fat 18-54 Double Pressed 18-55 Triple Pressed SPECIALTY COCO ACIDS Neo-Fat Commercially Pore Caprylic 10 Commercially Pure Capric 12 Commercially Pure Laurie 14 Commercially Pure M y ristic 2 6 5 Double Distilled Coco Plus tailored blends of coco fractions SPECIALTY PALMITICS A N D STEARIC ACID Neo-Fat 16 Commercially Pure Palmitic 16-54 7 0 % Palmitic 18 Commercially Pure Stearic 18-57 6 5 % Stearic 18-58 7 0 % Stearic 18-61 8 0 % Stearic OLEIC ACIDS Neo-Fat 92-04 Low Titer White Oleic 94-04 Low Titer Red Oil 9 4 - 1 0 High Titer Red Oil

a long way since the first announcement by D u Pont early last year (C&EN March 7, 1955, p. 9 5 6 ) . T h e develop­ ment has grown from laboratory to pilot plant and last fall Riegel Paper made the first commercial run of nylon paper. D u Pont is continuing product development work and extending mar­ ket research. Others actively inter­ ested in addition to Riegel and D u Pont include: Great Northern; St. Regis Paper; Rogers Corp.; Kimberly-Clark; and the Herty Foundation. Successful synthetic fiber paper runs have already been made on the four major types of production machinery. Recent work has pointed up the im­ portance of selecting the proper bond­ ing agent and its concentration in the paper to attain optimum physical prop­ erties, says D u Pont's John R. Emery. T w o methods of bonding have been developed: solvent bonding and syn­ thetic polymer bonding. T h e so-called "salt bonding*" i s a type of solvent bonding. Water solu­ tions of certain salts at high concentra­ tions are solvents or swelling agents for synthetic organic fibers. A dilute salt solution when allowed t o evaporate from a w e b of synthetic fibers con­ centrates at their points of contact and dissolves some of the resin. Complete evaporation precipitates the resin and bonds the fibers. But synthetic polymers, in the form of resins or thermoplastic fibers, are proving to b e more practical than sol­ vents, says Emery. They can be ap­ plied to the fibers in the sheet as dis­ persions, as solutions, or as fibers. Desired properties of the final prod­ uct will direct the choice of binder, its form, and its concentration. For example, Emery explains that the optimum concentration of one type of dispersion-applied polyamide binder for maximum tear strength is 2 0 % . But when the same binder is used in the form of thermoplastic fiber, maxi­ mum tear strength is achieved at a con­ centration of 10%. And while tear strength is maximum at 20% concentra­ tion of dispersed polyamide binder, tensile strength reaches a maximum at 30%. ί Thermoplastic Bonding· Interest­ ing and promising results have been

achieved by using fibers with lower melting points than the fibers to be bonded, says the D u Pont spokesman. With this technique, binder fibers are blended with base fibers in the slurry before sheet formation. Bonding i s ac­ complished b y hot pressing the sheet at the end of the dryer section of the papermaking machine. Most of D u Pont's work t o date on thermoplastic fiber-bonded papers has been done with Dacron polyester fiber and binders of experimental polyester fibers which have melting points 80° to 150° F. below that of conventional Dacron. Tensile strength and elonga­ tion of this synthetic fiber paper in­ crease with the content of the ther­ moplastic fiber, reaching a maximum at about 4 0 % . Burst strength also in­ creases t o a maximum at about 309fc thermoplastic fiber content. Tear strength i s inversely proportional t o the thermoplastic fiber content. Fiber length is another important variable. Short fibers make a better slurry, while long fibers improve the physical properties of the finished sheet. Fiber length of about one-quarter inch appears t o give the best balance be­ tween paper properties and ease of handling. • Pilot Plant Studies. Conclusions resulting from pilot plant studies i n which D u Pont cooperated with six different paper manufacturers include these: • Mechanical cutting of t h e fibers t o proper length eliminates the beating operation. This should result in sub­ stantial savings in time, power, and equipment for the manufacturer. • Waterleaf strength of 100% synthetic fiber sheets i s low compared with wood pulp. Techniques found t o overcome this problem: addition of resins t o the finish; addition of wood pulp; the elim­ ination of the gap between the couch roll and the dryer felt by use of a pick­ up felt. • Experimental runs of 100% synthetic fibers had been made o n regular Fourdrinier machines, tri-wire type Fourdrinier machines, Rotoformers, and cylinder machines. Most difficult were cylinder machines because of the ex­ treme freeness of fibers. MARCH

12, 1956 C & E N 1 2 6 9

CHEMICALS

THE VERSATILE

mm r Keeps Out Moisture

OF PERFUMERY Only α few decades ago, the sole appli­

The permeability of concrete blocks, mortar, plaster, stucco, and concrete is decreased by about 50% when from 2 to 49fc of Losorb, moisture-proofing addi­ tive introduced by Pennsylvania Industrial Chemical, is added. When water is applied simultaneously to two concrete blocks, treated one on left is impervi­ ous; block at right, untreated, absorbs water. Losorb is also said to minimize crack frequency and to make the mix more plastic and easier working. CS 1

cation of perfumery was to enhance the appeal of a large variety oi personal products. While perfumes and cosmetics are still of primary importance* the field of fragrance has recently entered into a vast new e r a - t h e era of industrial odorants. From household products to manu­ facturing processes, lube oils to smoke­ stack deodorizing the field now extends. Today's perfume chemist moves in an ever widening area, filling new demands lor his specialized services and in so doing creating a versatile and expansive new industry. For more than 157 years. Ό&Ο has served the perfume industry both traditional and developing. This ex­ perience becomes the invaluable prop­ erty o i all D&O customers.

DO i l lJ: IM I JiHIM

OUR 157th YEAR OF SERVICE

DODGE &0LC0TT. INC. 180 Yarick Street · New York 14, Ν. Υ. Sales Offices in Principal Cities

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12,

1956

• Because the dry web strength of 100% synthetic-fiber paper is not sufficient to carry it through the dryer section of the papermaking machine, it is neces­ sary to apply some binder to the wet web. • The impregnated sheet is dried in a conventional manner. As the water evaporates, the binder tends to con­ centrate at the crossover points of the fibers. This provides sufficient strength to carry the sheet through the dryers. Bonding process is completed by heat and pressure i n calender or press. • Potential Uses. Most promising potential uses according to Du Pont people include: paper-like structures for electrical insulation, high-pressure laminate reinforcement, map and chart paper, tracing paper and cloth; fabric­ like structures for nitration, tarpaulins, coated fabrics, laundry press covers, electrical tapes; and felt-like structures for low-pressure laminate reinforcing batts, laundry press pads, filter felts. In the home furnishings and apparel market there are these additional poten­ tial uses: draperies, carpet backings, linings, interlinings, shoe fabrics, and special clothing applications. "The unique physical and functional properties of papers prepared from nylon, Dacron polyester fiber, and Or­ ion acrylic fiber, and from blends of those fibers with wood pulp, should per­ mit their use i n many areas where paper is not normally used," concludes Emery. Tests made during the past year showed that b y adding 25% nylon to a pulp bonded with polyamide binder, the tear strength of die paper was im­

proved 3 V 2 times and die fold en­ durance 42 times. Tear strength of 100% nylon paper on the average is 1 4 times greater than cellulosic paper bonded with the same resin, and the fold endurance is more than 7 5 times greater, Emery says. A technical report on the synthetic fiber paper developments was presented before the recent meeting of the Technic *. Association of die Pulp and Paper Industry i n N e w York by Emery and his Du Pont associates, J. Donald Howell and Seymour Sands.

• Concentrated liquid fertilizer for lawn and garden use, Shur-Green, will b e offered to most areas in Midwest this spring, according to manufacturer, Continental Fertilizer. New product has been fully tested for two years, company says. It may be applied as turf or soil is watered; 1 gallon is said t o be sufficient t o fertilize 2000 sq. ft. CS2 • The Lockrey Co· is now offering its Liqui-Moly (MoS 2 ) lubricants in a stabilized form so that uiey may be used in severe applications involving extremes of temperature, pressure, speed, and exposure. A new buffer, called Stabilex, prevents the formation of any free acid, company says, and also protects oil in which the MoS 2 is sus­ pended from oxidation or acidity in use. CS 3 ί Contact cement, called Stix-Crip, makes it possible to adhere plastic lami­ nates such as Formica, Consoweld, and

Precision graduated for perfectionists. . .

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extremes to see that they hold what the lines say they do. We make our bu­ rettes with a special precision bore, the purpose of which is to provide ex­ tremely fine accuracy between any two points. And with certain special grad­ uated items, we enclose a Corning Cer­ tificate o f Accuracy . . . an ironclad, gilt-edged testimony to precision cali­ brations.

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ΙΜ Chemicals In 1803 Or. John Jord of London noted tbat when granulated tin was used as a purge for worms in humans, it also I une Honed as an excellent sedative. As such he prescribed il in several cases of hypertension. 7in remained Or. Jord's special sedative for years and England's standard worm remedy for nearly a century.

CHEMICALS Micarta to or presses, Products. ing and is

wood without use of clamps says its developer, Adhesive Adhesive requires no heat­ ready to use as received. CS4

• Silicone mold release emulsion de­ signed to give finer surface detail, bet­ ter surface finish, and greater economy in emulsion system operation has been developed by General Electric's silicone products department. Compound is designated as SM-62. CS 5 • Thermosetting insulating varnish based on epoxy resins, designated Thermopoxy T-653-LB, is offered by Ster­ ling Varnish. Company says new ma­ terial has exceptional electrical insula­ tion endurance in the presence of chemical atmospheres, moisture, and radical temperature changes. It is a noncatalytic varnish, curing upon ex­ posure to a baking temperature of from 135° t o 150° C. Coating is also said to have exceptional adhesion and bond­ ing strength. CS 6

Further useful information on keyed C h e m i c a l items m e n ­ t i o n e d is r e a d i l y a v a i l a b l e · . . u s e πα it a'y c o u p ΦΑ ôfi p a g e 7250 ψ

Who Makes It? T O D A Y a c o m p o u n d o f tin is doing a r e m a r k a b l e j o b as an a n t i - w o r m a n t in veterinary medicine. A few y e a r s ago D r . Salsbury's Laboratories, pioneers in p o u l t r y pharmaceuticals, were looking for a chemical t h a t w o u l d b e n o n - t o x i c for p o u l t ^ , b u t effective against the d e a d l y p o u l t r y t a p e w o r m , Raillietina cesticillus. F o r experimental p u r p o s e s h u n d r e d s of c o m p o u n d s of tin were s u p ­ plied b y M e t a l & T h e r m i t . M & Τ D i b u t y l t i n D i l a u r a t e is now c o n ­ tained in t w o p a t e n t e d formulations of D r . S a l s b u r y ' s " W o r m a l , " o n e of t h e m o s t effective p o u l t r y tapewormers ever developed.

T H E VERSATILITY O F TIN CHEMICALS is by no means limited to medicine. In any field—automotive, aviation, textile, food, plastics—if you're looking for ways to lower costs or improve techniques, it will pay you to get in touch with us— TIN « TIN CHEMICALS CERAMIC MATERIALS 0R6ANIC COATINGS WEL0IN6 SUPPLIES RADIOGRAPHIC EQUIPMENT PLATING MATERIALS METALS * ALLOYS HEAVY MELTING SCRAP

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T h e National Registry of R a r e Chemicals, Armour Research F o u n ­ dation, Illinois Institute of T e c h ­ nology, 3 5 West 33rd St., Chicago, 111., is interested in locating sources of s u p p l y for t h e following chemi­ cals: Resorcinol-4,6-disulfonic acid 1,2 - Diaminoanthraquinone - 3 sulfonic acid 1,3-Diphenylpropane 1,3-Diphenylbutane Dimethylmalonic acid 6-Hydroxyindoline 5-Methylcaproic acid 1,2,3,4,4-Pentachlorobutane 4-Phenyl-2-butanol 2-Phenyl-l-naphthol Pentachlorofluoroethane Propylene glycol-a-monoacetate Propylene glycol-j3-monoacetate Thorium carbide 2,3,6-Trichloroaniline 1,2,4-Triazole 5-Octadecynoic acid D-Threose Thioisatine 3-Thianaphthenol