Recent chemical patents

Method of Producing Self-adhering Gauze Bandages. No. 2,337,390. John A. Hincamp, et al., Lake. Bluff, Illinois. This is just what the doctor will soo...
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WILLlAj\f S. IDLL Member, Examining Corps, United States Patent Office Method of Producing Self-adhering Gauze Bandages No. 2,337,390. John A. Hincamp, et al., Lake Bluff, Illinois. This is just what the doctor will soon be orderingalso a new item for the first aid class. While self-adhering gauze bandages have been on the market for some time, their quality has not been such as to cause them to replace the usual nonadhering gauze bandages. This patent describes the manufacture of an improved product. An ordinary openmesh gauze bandage is run through a bath of latex containing an ammonia preservative. After all but a small quantity of the latex has been removed by squeeze rolls, the gauze is subjected to an air blast which removes part of the ammonia. The web then passes into a 1 per cent solution of acetic acid. Quick coagulation of the latex occurs and no scum forms because the excess ammonia has been removed. The coated gauze is next treated in a water bath to remove free acid. Thorough rinsing also removes all of the serum or protein content liberated upon the setting of the latex in the acid bath. The product is described as being pure white and soft, and as having good keeping qualities. It does not stick to skin or hair like surgical adhesive tape, and to use it all that is necessary is to lap it on itself and gently rub the free end down. Interpolyamides. No. 2,336,824. Richard H. Wiley, Wilmington, Delaware. This is probably another step in putting the Jap silk worm out of business. The invention relates to the production of fiber-forming materials of the linear polyamide type by interpolymerization of a mixture of two or more different diamines with one or more dicarboxylic acids, or of two or more dicarboxylic acids with one or more diamines. Products having high melting points together with good solubility and pliability are prepared by the present process. One example of the process is as follows: 76 parts by weight of hexamethylenediammonium sebacate having a pH of 7.30 and 124 parts by weight of tetramethylenediammonium adipate having a pH of 7.25 are heated in a sealed glass tube for two hours at 210° to 220°C. The reaction product is then further heated for two hours at 255°C. under a 3- to 4-mm. vacuum. The resulting polymer is clear and tough and has a soltening point of 199°C. This type of in terpolyamide is of particular value in the manufacture of fibers, wrapping foils, and coatings for fabrics.

Sensitive Material. No. 2,336,299. John Russell, Rochester, New York. We hope the F.B.I. knows about this paper which is both photosensitive and heat-sensitive. It forms metallic salts of the cellulose of the paper fibers, which are sensitive to heat, light, or electrical stimuli and are capable of having photographic images formed and developed therein. The paper is dipped in a solution of equal parts of concentrated sulfuric acid and water saturated with potassium dichromate. Dipping time is about 30 to 60 seconds. Aft.. being washed free of sulfate and dried the paper is fairly sensitive to heat. The paper, which now has an oxidized surface layer, is then bathed in a metallic salt solution, such as 1 per cent silver or mercurous acetate. The time is not critical. This bath is given under dark room conditions. The resulting paper is much more sensitive and will show a legible mark from a stylus at 300°C. moving 8 to 10 mm. per second. It also gives strong images with less than one minute exposure at a distance of 30 em. from a Cooper-Hewitt arc lamp. The paper may be used in industrial recorders which have heated styluses. Method for the Rapid Direct Analysis of Oxygen in Steel. No. 2,336,075. Gerhard Derge, Aspinwall, Pennsylvania. This patent should interest the analytical chemist. By this method, it is asserted, an analysis of oxygen in the melt may be made in five minutes. It is ap-

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plicahle to the control of the open hearth. Bessemer, or electric funlace process. A sample is taken from the steel bath with a small well-slagged spoon. The sample is rapidly frozen hy being poured into a small split, wedge mold. This quickly stops the reaction between the carbon and the FeO. A 10- to 20-g. portion is taken off the lower part of the sample and placed in a fusion apparatus (Figure 1). In the apparatus an induction funlace surrounds the crucible assembly (Figure 2). The

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Vinyl Resin Phonograph Record. No. 2,335,98. Victor Yngve, Lakewood, Ohio. The supposedly good substitute for the shellac typl phonograph disc may be welcome news for the home recorder. It makes use of a molding composition containing vinyl resin of the copolymer type, with substantial amounts of a soft abrasive, such as diatomaceous eartb" and a vegetable charcoal. A wide variety of the. customary plasticizers, waxes, lubricants, heat stabi' l lizers, and pigments may be included. The large pro-, portion of filler reduces the cost. The use of vegetable, charcoal keeps surface noise low. X-ray Contrast Composition. r o. 2,336,022. Haroldl H. Lefft, et at., New York City. This patent promises improved technique for obtain·) ' ing x-ray photographs of delicate body organs. It describes the use of diiodo tyrosine which has the general fonnula

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The com pound is suspe'nded in an aqueous colloidal vehicle such as a solution of gelatin. The composition may be injected into lungs, kidneys, sinuses, joints, cavities, etc. It is well adapted for neuro diagnoses because it may be injected into the ventricles of the brain. The x-ray photography should be completed within a few hours since the compound is absorbed and excreted through the kidneys.

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sample is placed in the crucible, which is made of graphite and is surrounded by a graphite spacing shield. The apparatus is heated and evacuated, the crucible is raised to a temperature of about 1400°C., and the sample is manipulated into it. The carbon and oxygen in the sample react to form carbon monoxide, which is evolved along with a small quantity of hydrogen and nitrogen, and collects in a reservoir. Here its pressure and volume are easily measured. It is stated that the method is so rapid that sampling and analyzing may be made and a deoxidizer added while the bath is still in a molten condition.

Composition of Insecticide Spray and Method of Making It. No. 2,335,862. Walter C. Klingel, Union, New Jersey. We should like to see this in the stores before the insects get the upper hand next summer. It uses unsymmetrical dibutyl urea or N,N-Di-1zbutyl urea as a solvent for rotenone and its derivatives. Strong solutions can be prepared which are highly toxic to insect life. In the past it has been customary for the average gardener either to dust the insecticide in powder form or spray in water suspension. Most known solvents which are not injurious to plant life do not dissolve rotenone to any extent.

EDITOR'S OUTLOOK (Conlinued from page 105) When asked what percentage mIght be expected to go on from the basic into the advanced ASTP, he said: "That depends on the demands from the Army and principally on the demands from the ground forc;os. They want a certain percentage of those who have completed their basic term. They are apparently quite short now in noncommissioned officers. It is quite likely that they may raise that percentage so that even more may be returned to the ground forces ..."

When pressed for a figure he said that originally

about 40 per cent were expected to go on to the advanced program, but that this might be reduced to around 25 per cent. Altogether, it was the clear result of the whole dis· cussion that the basic phase of the Training Programs may lead to officer training-but probably not in most cases-and that a relatively small percentage of trainees will go into the advanced phase, where there is any possibility of their becoming "trained technologists."'