US844849A - Process for producing mantles for incandescent gas-lighting. - Google Patents

Description

, 'ble of causing them to swell without disso UNTTED STr-iTFJS PATENT UFFTCE.

JOSEPH ARMAND ERNEST HUBERT BOULLIER, OF PARIS, FRANCE.

PROCESS FOR PRODUCING MANTLES FOR INCANDESCENT GAS-LIGHTING.

Specification of Letters Patent.

Patented Feb. 19, 1907.

Application filed March 23, 1303. Serial F0. 149,199.

To all whom, it may concern.-

In order to enable the nature ofthis inven- Be it known that 1', Josnrrr AR -AND EnN- l tion to be clearly understood, the following EsT HUBERT BOULLIER, a citizen of the lie- 1 example is given for the purpose of showing public of France, residing at Paris, France, 1 hey it maybe carried out) Nitric acid re seave invented Improvements in the Process for Producing Mantles for Incandescent Gas- Lighting, of which the following is a specification.

Many attempts have been made to produce incandescent gas1nantles from artificial silk and the like.

All the processes heretofore proposed have consisted in introducing incandescing comounds into-a viscous solution ofnitrocelluose capable-of being spun into filaments, s inning th e viscous mass into filaments, and then denitrating the same.

Nitrocellulose filaments are not penetrated by water, and they are therefore not adapted to fix incandcscing compounds; but they ac- (1}?116 this property in a high degree when t ey are treated with liquids which are capa- 'ing them. Certain acidssuch as formic acid, acetic acid, and nitric acid in suitable erty.

The following table discloses the possible and preferred dilutions of such acids for use in my process:

Possible Preferred proportions. proportions.

60 to so. Acptilc acid, (crystallizable,) 75

f 4 z. 40 to 20. Water, H2O to .30. Nitric acid, HNO to 50. atcr, H2O 5O to 100. Formic acid, CH O 10 to 0. Water, 1110 0 As appears from the above table, formic acid is used undiluted and at its maximum concentration. The same result may also be obtained by using alcohol mixed with a-small quantity of commercial ether or with alcoholic ethers (ether salts) or with acetone and generally with any liquids or substances which alone or undiluted are capable of dissolving nitrocellulose. By reason of the presence of a liquid which has no dissolving action on nitrocellulose these mixtures may effect the swelling of the said filaments without dissolving them. The filaments thus phys icslly modified are still nitrocellulose; but they have acquired the p .operty of absorbish their absorbent capacity.

lies of iucandescing salts.

leeted as an example, because this acid is the cheapest; but the operation would be equally successful with concentrated formic acid of about ninet -five-per-cent. strength or with crystallizab e acetic acid mixed with a small quantity of water. The degree of dilution of these acids may vary according to the tempcrature at which the operation is effected. The other liquids referred to hereinbefore may also be employed. It is to be understood that all the operations hereinafter de scribed are equally applicable to nitrocellulose ainents as well as to knitted or Woven fabrics made of these filaments.

The process is as follows:

. First. The filaments of nitrocellulose are introduced into the diluted nitric acid of referably 35 01' 36 Ba'um, and they are eft to macerate in the acid until they have swelled up considerably. They have now become transparent or opaline and have a gelatinous appearance. Several hours are re uired in order to produ e this result at or inary atmospheric temperature; but the transformation is much more rapid at a term perature of about 35 Celsius. When the filaments have assumed the appearance above described, they are taken out of the acid, washed, and then treated in a centrifugal machine, and then they may be dried or not dried, as desired; but for the following operations it is-preferable to employ the filaments in the moist state, so as not to dimin- This operation not only renders t e filaments ada ted to fix the incandescing' salts, but also e iminates any mineral matters which may be contained in the nitrocellulose and which would injuriously affect the illuminating power or the strength of the filament.

Second. The nitrocellulose filaments thus modified are then immersed in a solution of, for instance, one hundred parts of commercial incandcscing nitrates to one hundred parts of water. These proportions will vary according to the weight of the incandescing compounds which it is desired to fix in the filaments. After several hours of impregnation and even much less, especially if the opof heat, the filaments are taken out of the 1 bath, then treated in a centrifugal machine or squeezed for the purpose of eliminating therefrom the portion of the solution which has not become fixed. Then the filaments are left to dry at a gentle temperature.

Third. These filaments ofnitrocellulose thus-impregnated and dried are 'subjected'to a denitrating process, such as the processes of denitration employed at present in the manufacture of artificial silk, but, by preference, to treatment with hydrated sulfate of ammonia, because it does not introduce into the filament any foreign substance which cannot be removed by washing with water.

The filaments produced by these operatlons are knitted or'woven into mantles, or if the mantle itself has been treated the only remaining operation is to incinerate the mantle.

By this invention mantles may be'produced lighting from nitrocellulose, said method consisting of first subjecting nitrocellulose filaments to a substance capable of causing said filaments to swell without dissolution and after thus causing them to swell, impregnating them with inca'ndescing compounds.

Signed at Paris, France, this 7th day of March, 1903.

JOSEPH ARMANI) ERNEST HUBERT BOULTIIER.

Witnesses:

BENJAMIN BLOCHE, AUGUSTUS E. INGRAM.