Agreement of an Accelerated and an Exposure ... - ACS Publications

INDUSTRIAL AND ENGINEERING CHEMISTRY

November, 1927

From what has been done it see.ms certain that wherever metallic coating is required and the size and shape of the pieces involved make possible degasification and plating by the process outlined, better adherence, substantial freedom from pits and pinholes, and consequently better protection against corrosion can be obtained. Degasification therefore assumes a major role in the problem of rendering metals non-corrosive. In a later issue details of a commercial plant design will be presented, including a new, unique method for removing polarization gases. Patents

The patents upon which the development described above rests are listed in the table. I n addition to these issued patents, there are on file in the

1226

United States Patent Office a great many applications, part of which are under allowance and which further describe the process. Patents have also been issued in sixteen foreign countries. NUMBER 1,513,119

DATEOF ISSUE Oct. 28, 1924

1,513,120

Oct. 28, 1924

1,562,710

Nov. 24, 1925

1,562,711

N-ov. 24, 1925

1,564,710

Dec. 8, 1925

1,575,122

Mar. 2, 1926

1,583,891 1,584,959 1,607,960

M a y 11, 1926 May 18, 1926 Nov. 28, 1926

1,607,994 1,608,706

Nov. 23,1926 Nov. 30, 1926

SUBJECT Electrodeposited article and method of making same Phonograph record and method of producing same Method of treating metallic objects and resulting products Coated metallic article and method of making same Method of coating with metals and resulting products Mold, die, and the like and method of making same Process for electrodeposition of metals Electrodeposited metal Method and means for electrodepositing nickel metals and the resulting products Means for electrodepositing metals Electrodeposition of metals

Agreement of an Accelerated and an Exposure Test of Structural Paint’ By Edward D. Gregory FRAZER PAINT COMPANY, DETROIT,MICH.

K 1913 an accelerated test of structural paints was conducted by Norman A. Dubois, of Boston. An exposure test of these paints was carried on by a large railroad. The concordance of results obtained by these check tests is striking. I n an article entitled “The Protection of Iron and Steel by Paint Films,”2 Dubois discussed briefly the theories of the corrosion of iron and steel, and pointed to the fact that moisture must be present for corrosion to take place, whether the carbonic acid theory, the peroxide theory, or the electrolytic theory is assumed as the explanation of corrosion. Applying his study to the effect of paint films of different types for retarding corrosion, he set up an accelerated test, in which steel panels, after being coated with various paints, were placed in a sealed cabinet and subjected to the corroding influences of sulfur dioxide, carbon dioxide, and moisture. The special paints for this test were made under the personal direction of the writer, to determine if red lead could be strengthened or improved by the addition of other pigments, and also the effect produced on the vehicle by the addition of varnish gums and treated oils of different types. I n the case of the red lead, a 94 per cent true red lead was extended with 20 per cent of special clay of extreme fineness and individual qualities. In the case of the black paints submitted, a constant pigment formula was used, consisting of 15 per cent of gas carbon and 85 per cent of this special clay. This was made into paint by mixing with a vehicle consisting of 90 per cent pure boiled linseed oil and 10 per cent drier. To ascertain if this vehicle could be rendered denser and more impervious to gas and moisture, different percentages of kauri mixing varnish were added and equal percentages of linseed oil omitted. Treated Chinese wood oil, non-volatile mineral oil, gilsonite, asphaltum varnish, elaterite varnish, lithographers’ oil, special kettle-boiled linseed oil, and thinning oil used by

I

1

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Received M a y 2, 1927. THIS JOURNAL, I,968 (1913).

railroads for reducing freight-car paint were all included in the tests for reenforcing the vehicle. Samples of oxide of iron paint containing 40 per cent of FezOs and 60 per cent of the special clay and samples of green, consisting of 15 per cent of chrome green and 85 per cent of the special clay, were also included in the test. Table I shows the pigmentation and vehicle combinations submitted for the accelerated test. Table I No. 01-A 01-B

PIGMENT carbon. 85% special clay carbon: 85% special clay

01-c

carbon; 85% special clay

01-D

carbon; 857, special clay

01-E


01-F


01-G


01-H


01-1


01-J


01-K


01-I,


01-M


01-N

carbon; S5% special clay

01-0

carbon; 8.57, special clay

01-P 01-Q

01-R


013


01-T


07-A 07-C

40% oxide iron; 60% special clay 40% oxide iron; 607, special clay

16-A

15Y0 chrome green; 85% special clay 15% chrome green; 857, special clay 80% red lead; 20% special clay

16-C

0-F

VEHICLE 90% boiled linseed; 10% drier 85% boiled linseed. 10% drier; 5% kauri mixing’varnish 80% boiled linseed; 10% drier; 107, kauri mixing varnish 70% boiled linseed; 1 0 7 drier; 20R kauri mixing v g n i s h 60% ’{oiled linseed: 10% drier: 36% kauri mixing vainish ’ 787, boiled linseed; lOYc drier; 5% mineral oil; 7 % kauri mixing varnish 83% boiled linseed; 10% drier; 7 % mineral oil 767” boiled linseed: 10% drier:

Formula “F.” except elaterite used 40% treated linseed; 10% drier; 50% kauri mixing varnish 67% boiled linseed; 33% thinning oil 67Tp boiled linseed: 33% thinnlng oil containing various oils

90% boiled linseed: 10% drier 80% boiled linseed; 10% ,drier 10% kauri mixing varnish

90% boiled linseed: 10% drier 80% boiled linseed; 10% .drier: 10% kauri rmxlng varnish 90y0 raw linseed; 10% drier

to those who do not possess B copy US tliih origiiral article, it S ~ C I I I Jproper to include in this paper a considerable portion of the Ihbois article, presenting also the original illus-

trations, t.hat comparisons may be made with the photogrqihs of the time tests. After discussing the various (Iieories of corrosion, tlic protection of irori and steel by pnint films, the classification of pigment,s into corrosion :iccelernlors, corrosion inhibitors and inerts, aid the permeability of paint films, he writes: is but lo conclude that the paint tilni which will serve or steel against corrosion is the one which is the least pervims to aqueous vapor, the gases oxygen and carlion dioxide, or in Pact any gas in the smroundirrg atmosphere wliicli may in aiiy way cause or sccclcrate corrosion.*** 'l'lic problem is a physical m e ratlrer tlian a chemical om, ;urd 8 comparison of paint films as to their relative obstruction to the diiiusion of gases will tell more regarding their value as iirotectioii against corrosion than B study o i inhibitive action of tlicir pigmcnts."" Oiir i i r i m e object is to make the 5 I r n as impervious to gases as ims$ii$v. This may be accomplished to a certain extent by special trcatment of the vchiele and by incorporating special i)iimitxts and i,imnent combinations. It is well known thAt B &I& from the oxidation of pure linseed oil, i. e., it film of iinoxin, is niore or less permcablc to moisture and gases. I t is more or less ixmx~s. If other oils or guu~tis,o r similar materials, can be incorporated with the linseed oil to form a homogeneous mass which as a whole acts as a perfect vehicle as regards compatibility or Ixuperties, it is rendily understm~dablethat such treatment may, to an extent, till the intermolecular spaces bctween the liiisecd oil molccoles, just as in other cases of solution, alloy, or miatire; and this cumpouiid vehicle will be more dense, will leave a film which offers more resistance to the diffusion of gases, and will, therefore, protect the iron and steel for a longer time (assuming other things equal) than a film which has not been treated in this way. P k t e I shows five steel panels which, after thorough cleaning with liot 10 per cent solution of sulfuric acid for twenty minutes, washiiig by immersion in dilute caustic solution. thoroughly wasliing with water, and quickly drying, were painted as follows. All paints were o f the same formula, with the exception of cine cmistitucnt in the vehicle. longest time 9s a yrotection to iron

Plste I-Steel

Paneis Painted with Paints of S n m u Formula except On0 Constituent Of the vehicle

l?md n is h pure Iiniced "il Yr1,iCIe l'nnei U confains 6 per cent of kauri imixiiiz udrzrish $81 tlir vel$idc Iknel C contains 10 per cent 01 kauri mixing v ~ r i i i s l i n the vehicle Pneel U contains 20 per cent o i kauri mixinbr varnish in the uehiclr Panel E coatains 30 per cent oi kauri miring varuis1, in that it may be disregarded here.) To accomplish this result distillation has been necessary. The ideal of the water purification worker, of “distilled water without distillation,” appears to have been achieved, with certain limitations, by the process of electroosmosis, which has been developed in Germany well past the experimental stage, with a number of commercial installations in successful operation.

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I .\‘D USTRIAL A N D B.VG1‘NEERING CHEMISTRY

t,he reiiiural of colloidal particles is said to take place for the most part in the last cells, where the voltage is highest. Ir water of extreme purity is desired the electrode compartments of the last two cells are rinsed with previously purified \water. Results

By this process it is claimed that an effluent water caii be produced equal in purity to distilled water, and superior to it For some purposes, a t a small part of tho cost for energy required by’distillation. A number OF installations that have been operating successfully in Germany and Austria for several years, includiug several plants recently inspected by the writer: whstantiate these claims. Application

Water purified by this method may be ernpluyed in general xliererer di~tillctlwater is now employed, suchfas in labora-

lation the total amount of rinsiug water required is only a very small Fraction of the cooling water employed in smallscale distillation. The only attention required for tho apparatus is the occasional cleaning of the diaphragms. The necessity For this arises from the fact that when the calcium and magnesium ious are discharged in the cathode chamber the products of electrolysis, together with tlie reaction products OF these on the raw water, gradually produce a deposit, chiefly calcium earbunate and magnesium hydroxide, in the ilinphragiii. An extra set of diapllragms is usually supplied, so that the cleaniug, which consists simply in immersing first in dilute hydrochloric aoid and then in plaiii water, may he carried (nit a t leisure. The Frequency of cleaning is therefore dependent on the hardness OF the water to be purified and For the avera.ge water ha8 been fouud to be once in 2 or 3 weeks. Pretreatment of Water

Althougli the cleaning oF tlie diapliragiua is ueitlier a dilficult nor lengthy operation, the necessity for it may be materially reduced, or even practically eliminated, b y first chemically soFtenine the water to remove the offendine calcium and magnesium. Wat-er softening by either the lime-soda or zeolite process is usually much iheiper than by the electroosmotic method. Either may be used as a pretreatment to prevent clogging of the diaphragms in the electroosmosis apparatus, but one may be preferable to the other, dependinnlnrgely on the type of water being treated IF the water contains a considerable amount of calcium m d magnesiun bicarbonates-i. e., temporary liardneslime treatment will remoYe these compounds bodily, thus not only largely preventing clogging of the diaphragms, but also materially deerellsing the eonsumption OF electrical energy required. Owing to the inherent limitations of the liie-soda process, however, the calcium and magnesium are not conipletely removed. The zeolite or base-exchange method, on the other hand, will replace the calcium and magnesium in their compounds in tlie raw water quite completely with sodium; but as this exchange does not result in a reduction of dissolved solids, the consumption of electrical energy is not reduced in the subsequent purihation by electroosmosis. In some cases it may be desirable to employ a preliminary lime (or lime-soda) treatment, followed by zeolite treatment and thus obtain the advantages of both methods. I

Figure I-Apparatus for Purifyin8 Wafer by ElectroGsmosIa

tory and pharuieceutical work of ell kinds, storage batteries arid accumulators, bottled waters and other beverages. The extension OF such uses to larger scale applications, such as for boiler Feed water, ice-making, ete., where the economies of multiple-effect evaporation may be available, will depend largely on the comparative costs of electric current and fuel, and on other local conditions. Limitations and Cost of Treatment

N’hile n u definite upper limit can be set at this time, indications are that the process cannot be used economically with water coutaining a total solid content of more than about 1000 mg. per liter (1000 p. p. m.). With the average water treated by the process, having a total solid content of 250 to 300 mg. per liter, the energy consumption is about 2 to 2.5 kilowatt-hours per hectoliter (75 to 95 kilo%,att-hours per 1000 gallons) of water equal in purity to distilled water. IF, as is frequently possible in some industrial and tecli&a1 operations, a residual totaI solid content of 30 or 40 mg. per liter is permissible, the energy consumption may be reduced very considerably, as it is relatively more expensive to remove the last remaining dissolved solids than tliose removed first. The energy consumption may likewise be materially reduced by recirculating the cathode rinse water, which is already partially purified. This also obviously reduces the total amount of rinse water used in the process, though it should be noted that even without this rec‘‘ircu-

Vol. 19; 3 0 . I1

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Development

In Germany the company that has developed the el=tro6srnot.ic process in its several applications is now a subsidiary OF Sieniens & Halske. Under licenso from tlie American holding company, the water pudcation process will he introduced and the equipment manufactured here as soon as experimental work now in progress has indicated the most desirable methods of adapting the process and equipment to American conditions.

Correction Atteutiuri has been called to a misstatement in the linai pardgraph of the article by D. H. Killeffcr entitled “A Year’s Progress iu Chemistry” [THISJOURNAL, 19, 1077 (1927)], with respect t o the action of the Arkansas legislature. This body, which adjourned in March, 1927, did not pass a “law prohibiting the teaching oi evolution in its tax-supported schools.” Such a bill was introduced and passed the House by a close vote but was defeated in the Senate without a record vote but apparently by a decisive majority.

Agreement of an Accelerated and an Exposure ... - ACS Publications

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