T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y .
478
modification of the reduction-process of boric anhydride by magnesium. Obviously for the purpose of eliminating oxygen from copper without introducing any impurity capable of alloying with copper, this boron suboxide would be as good a s pure boron or perhaps better on account of its being obtained in form of a very fine powder. This substance was used in the first experiment. The very first attempt was successful. A perfectly sound bar was obtained with a conductivity of 94 per cent. 0.1per cent. of the weight of the copper was added. Further experiments showed that the amount of boron suboxide could be reduced to 1/30’ per cent. and also that the addition of a large excess, say of I per cent., did not diminish the conductivity or change in any way the mechanical properties of the cast copper. Here was, therefore, a method which could be put into the hands of any foundry man and which would always give good results provided the coppei (ingots or scrap) melted down was pure metal. A further simplification could, however, be introduced into the process. The reduction of boric anhydride by magnesium, the first being in excess, gives a product containing magnesium borate, boric anhydride and boron suboxide. While the last one is the active agent, the first two are harmless. In fact, the presence of boric anhydride and magnesium borate is even a n advantage as the addition of a larger mass of material makes the operation easier; also the boric anhydride would probably dissolve the copper oxide and bring it to the surface as copper borate. It is therefore unnecessary t o submit the direct product of the reaction to chemical treatment for the purpose of isolating the boron suboxide. It is sufficient to grind up the mixture into coarse grains and use an amount of i t which contains the necessary amount of boron suboxide. The foundry practice a t present is to add I per cent. to 1% per cent. of this material which is equivalent to 0.08 to 0.1 per cent. of boron suboxide. The properties of the material obtained are as follows: The electrical conductivity obtained can be as high as 971/2 per cent. if the copper melted down is perfectly pure. I n the foundry, where the scrap copper which is melted down cannot always be very carefully selected, a conductivity of 91 to 95 per cent. is obtained and a guarantee of 90 per cent. is a t present given. The resultant casting is readily machined; fears which were entertained on this subject did not materialize and the engineers using the material have not complained on this account. The mechanical properties are as follows: Tensile strength, 24350
Elastic limit. 11450
Elongation. 48.5%
Reduction in area 74.49%
Castings are being made of all shapes and sizes with no more difficulty than in the case of brass. Sand and iron moulds can be used and for standard articles the latter are preferred. The use of cast copper lies in two different directions: I . Replacing forged copper. In this case a great saving in cost is often obtained. (2) Replacing alloys of copper. The gain i n conductivity allows the reduction in bulk and thus a saving i n material. The use of this material is spreading as the engineers get better acquainted with it and is already of very considerable magnitude. It is interesting to note that in spite of the fact t h a t cast copper has lower conductivity than forged copper, in many cases, as for instance, in case of current transformers, the effect of higher conductivity is obtained by substituting it for forged copper. This is due to the fact that in casting a chance is given to eliminate riveted screwed or soldered joints whereby a number of poor contacts are avoided. Not only this but the elimination of joints often insures a better operation. The cost of the boron added is small; at the present prices
Nov., 1910
of magnesium and boric anhydride the cost per pound of copper i s less than 0.73 of a cent. The success with “boronizing” copper, a s it is now called in the foundry, suggests new lines of work which I have taken up lately. Among these I mention: First, the addition of boron to different copper alloys. Second, the replacing of the poling operation in the process of refining copper by a “boronizing” operation. I n conclusion, I want to express my appreciation of the excellent work done by my assistant, F. A. Kroner, without whose energy and foundry experience the technical and commercial success of the process described would have been greatly delayed. CONTRIBUTIONFROM THE RESEARCH G E N ELEC. . Co., LABORATORY, WESTLYNN,MASS.
NOTES AND CORRESPONDENCE.
BAKELITE A N D RESINIT. Editor Journal of Industrial and Engineering Chemistry: On page 441, you publish a consular note about Resinit Compound. For the information of your readers, I beg to mention that the use of sodium sulphite, ammonium sulphite, tertiary sodium phosphate, sodium acetate, and all bases or basic salts, with which these Resinit compounds are made, as well as the impregnation of wood and other cellular or fibrous materials like infusorial earth, starch, etc., is broadly covered by my United States Bakelite patents: No. 939,966, filed Jan. 28, 1909. Issued Nov. 16, 1909. No. 941,605, filed Feb. I , 1909. Issued Nov. 30, 1909. No. 942,699, filed July 13, 1907. Issued Dec. 7, 1909. No. 942,700, filed Dec. 4, 1907. Issued Dec. 7, 1909. No. 942,808, filed Oct. 26, 1907. Issued Dec. 7, 1909. No. 942,809, filed Oct. 15, 1907. Issued Dec. 7, 1909. No. 942,852, filed July 13, 1907. Issued Dec. 7, 1909. No. 949,671, filed Feb. 18, 1907. Issued Feb. 15, 1910. No. 954,666, filed Oct. 15, 1907. Issued Apr. 12, 1910. No. 957,137, filed Oct. 8, 1909. Issued May 3, 1910. Several other patents are pending here and abroad, and will be published later on. For further information, I may tell you that the former manufacturers of Resinit have discontinued the manufacture of this article, and have purchased a n interest in the Bakelite Gesellschaft, m. b. H., in Berlin, who are the owners of my European patents, and who, for certain purposes, will supply also Resinit compounds. On this occasion, permit me to state that the first public mention of Resinit was made in Heidelberg, about one year after my French patents were published, and several months after I had read my paper on Bakelite before the American Chemical Society, and after it had appeared in this Journal, and translations thereof had been published in Germany and other foreign countries. I am pleased to state that since a few days, my United States, Canadian, Mexican and Japanese patents have been acquired by the General Bakelite Company, IOO William Street, New York City, and that henceforth, Bakelite and the raw materials thereof will be obtainable from that source. Respectfully yours, I,. H. BAEKELAND. TRIBO-LUMINESCENCE.’ The term “Luminescence” has been applied to the light which is emitted by various substances at a temperature much lower 1
1910.
Read at Chicago Meeting of Am. Electrochem. Soc., October 13-15,
