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INDUSTRIAL A N D ENGINEERING CHEMISTRY
water free from iron, manganese, acids, and alkalies. Excessive hardness gives rise to wastage of soap and increased cost for water-softening. The precipitate of calcium and magnesium soaps forms a greasy curd that sticks to the cloth, increases the labor of cleaning, and shortens the life of the fabric. Excessive hardness causes wastage of tanning material, and uneven shades in the leather. Waste matter in water can cause priming, foaming, and scale in boilers, and possibly corrosion—all aggravated by waste in river water. Apparently, the plan of attack should be: to increase the development and installation of closed systems, which can be used by many places that at present decry the idea; to develop new and better processes; to' institute intelligent research on the utilization of by-products; to separate
waste from drainage and storm water to reduce the cost of effluent treatment: to combine wastes, taking advantage of their differences in chemical character to render them innocuous or less harmful, and t o minimize their deleterious and destructive effects; to utilize heat in effluents by heat exchangers; to develop better machinery: t o utilize cheaper construction in plant design. There is probably no reason for the construction of elaborate concrete tanks when steel can be employed to better advantage and at a much lower cost. Steel has been used in water works for years, and undoubtedly can be used in sewage and trade-waste work with equal success. The present method of construction, erection, and welding in place makes steel a desirable material for treatment tanks.
VOL. 14, NO. 22
Many industries in the past had the wrong attitude toward stream pollution, but are slowly changing from the defensive t o the aggressive for the protection of their own interests. It is inevitable that eventually they will force each other and also municipalities to adopt stream protective measures. Every other consideration for stream recovery follows as secondary, since every worth-while project develops from individual initiative, which works out for the common good of all. This problem is a direct challenge to the chemists and engineers of America. Sufficient studies have been made to warrant far more activity than is in evidence. Concentrated study of individual requirements should soon break down those few cases where treatment might be found inadequate.
Improvements in Impregnating Textiles with Synthetic Resins C. H . S. TUPHOLME, R u n c t o n Cottage, Lower B o u r n e , F a r n h a m , Surrey, E n g l a n d MONG the British textile operators who A have taken a prominent part in the use of synthetic resins in the textile industry is the Calico Printers' Association, an influential group of textile printers. Chemists of that group claim to have perfected two processes—one for avoiding high temperatures in insolubility, and the other for improving the fastness of textiles to washing after treatment with synthetic resins. The first process is claimed t o be an improvement on previous ones involving the treatment of textiles with synthetic resins of the amido aldehyde group for the purpose of fixing certain desirable finishes (such as mechanically produced effects), or for improving fixation of dyestuffs in that it ensures insolubility or fixation of the synthetic resin in the fabric without the necessity of using relatively high temperatures which might injure the fibers or which require special equipment not usually available in textile plants. The process consists in the impregnation of the textile material with a solution of an early intermediate condensation product of an amidic component with formaldehyde, or with a solution of the amidic component itself, or of the amidic component and formaldehyde, followed by treatment of the textile in a steam atmosphere in the presence of gaseous formaldehyde, the impregnation and steaming preferably being effected in the presence of acid. Suitable amidic components are urea and its derivatives, thiourea and its derivatives, and dicyanodiamide. T o obtain the best fixation of dyestuffs or mechanically produced effects, the steam must contain a certain minimum proportion of formaldehyde vapor, such as is obtained when boiling a 10 per cent formaldehyde solution. The resin is insoluble o n the fabric o r fibers at temperatures slightly above 100° C , such as prevail in the steaming machines ordinarily used for the fixation o f dyestuffs on textile fibers. Examples of the new process follow: A viscose rayon fabric is dyed with Diamine Rose FFB, impregnated with a solution prepared b y dissolving 5 parts by weight of salicylic acid and 10 parts by weight of urea in water and making up to 100 parts b y volume, dried, and treated for 20 minutes in the vapor from boiling 15
per cent formaldehyde solution. The color is made fast to washing and soaping at the boil. Secondly, a cotton fabric is padded through a solution prepared b y dissolving 10 parts by weight of urea and 5 parts by weight of 80 per cent lactic acid and making up to 100 parts by volume, dried, conditioned, embossed, and treated for 20 minutes in the vapor from a boiling 15 per cent formaldehyde solution. The embossing is made fast to water and soaping at the boil. In the second process, the fastness to washing of dyeings on regenerated cellulose rayon, cotton, other vegetable fibers, natural silk, or mixtures of these materials is improved, or the fixation of dyes normally having little or no affinity for these dyes is made possible by dyeing the fibers with acid or direct dyestuffs, simultaneously or subsequently impregnating the dyed fibers with an aqueous solution of substances leading to the formation of a synthetic resin of the urea-, thiourea-, or dicyanodiamide formaldehyde type in acid medium, drying the fibers, and afterwards making the resin insoluble by heating the treated fibers to a temperature of 180° to 210° C. for 30 to 60 seconds. The amount of formaldehyde used is in excess of the molecular proportion required for the formation of dimethylol urea or analogous dimethylol compound. The chemists draw attention to the fact that, with the exception of the vat colors, none of the various dyestuff groups permits of the production of a comprehensive range of shades fast both to light and to severe washing treatment. Among the substantive colors used for dyeing and rinting vegetable fibers are many fast-toght dyes fulfilling most of the requirements as to shade and dischargeability but of very poor to moderate fastness to washing. On the other hand, direct dyestuffs giving shades which can be made fast to washing b y diazotizing and developing or by coupling with a diazotized compound are, with a few exceptions, of only poor to moderate fastness to light. Among the acid dyestuffs used for dyeing and printing silk are many possessing good fastness to light and other desirable properties, but which are very fugitive t o washing. The degree of improvement in washing fastness brought about by the present proc-
E
ess is stated to vary somewhat from dyestuff t o dyestuff, but to be, on the whole, more marked and obviously of greater value the lower the initial fastness to washing of a dyestuff. Thus, a substantive dyestuff which, if dyed or printed on cotton, viscose, or cuprammonium rayon, would not stand even the mildest soaping treatment without appreciable fading, becomes in many cases as fast to washing as dyeings produced with diazotized and developed or coupled substantive coloring matters. It is even possible, it is claimed, to achieve the fixation on vegetable fibers of dyestuffs which normally have no affinity for these fibers—for example, acid dyestuffs. Another feature of the process is the application of the amidic component and of the aldehydic component separately after the dyeing or printing, or the amidic component may be applied along with the dyestuff, and together with, if desired, a catalyst or condensing agent, the aldehydic component being applied afterwards, either in aqueous solution or in gaseous form in an atmosphere of steam. The resin is then made insoluble b y heat. Two examples of the new process follow: Twenty-five parts by weight of urea and 10 parts by weight of ammonium acetate are dissolved in 115 parts of water, and 100 parts by volume of 40 per cent formaldehyde solution are added. The mixture is allowed to react for 30 minutes a t room temperature. A cuprammonium rayon fabric dyed with 2 per cent Chlorazol Fast Scarlet 4BS is impregnated with this solution, dried, and heated at 200° C . for 30 seconds. The color withstands washing in boiling soap solution. Secondly, 10 parts by weight of urea, 4 parts b y weight of ammonium acetate, and 2 parts by weight of Chlorazol Fast Red K are dissolved in water and the solution is bulked to 100 parts by volume. A cotton fabric is impregnated with this solution, dried, and treated in an atmosphere of steam and an excess of formaldehyde vapor for 15 minutes. A heat treatment of 3 0 seconds at 200° C. completes the fixation of the color, which is then fast to hot soaping. EDITORIAL NOTE.
At leaat one U. S. patent
has been issued in this field. This is No. 1,734,516 (November 5, 1029) t o Tootal Broadhurst Lee Co., Ltd., the patentees being R. P. Foulds. J. T. Marsh, and F. C. Wood.
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