US2439598A - Luminescent signalling composition - Google Patents

Description

the dry finely divided state.

Patented Apr. 13, 1948 UNITED STATES OFFICE iiflfiflf: 33:35:33.

NoDrawing. Application uly; 5,1944,

Serial No. 543 515 2 Claims. (01. 252- 13) A This invention relates to means and methods of signalling at sea, or on bodies of wateri'or on the surface of the earth.

To carry the invention into effect, and, to quote one example Without departing from the spirit of the invention said invention being of use by submerged craft-by surface craft-and by aircraft and by personnel of such defined craftI take a powerful dyestufi such as fluorescein, sodium fluorescein and the like and to said fluorescein or its salts, separately or in combination, add a specially processed combination of strontium carbonate, sulphur, sodium carbonate, sodium chloride and manganese sulphate.

This combination of substances not only exhibits a signal visible in daylight but also at nightfall, and during the night exhibits a luminous, fluorescent and phosphorescent effect calculated to indicate the need for investigation when such a signal is observed. The signal device as regards the chemical composition may be in a dry comminuted form, or may be in an emulsified form or may be in a colloidal form or in a crystalloid formand may be so assembled to prolong the period of dispersionthus to offer a longer period of time the signal on the surface of the sea or body of water or in an area approximating the surface of the sea would be visible. In carrying the invention into effect said example not limiting the invention to the example described I take nine parts sodium fluorescein sometimes called uranine, and intimately mix with one part of titanium tetraiodide in any of the following vehicles, oil, soap solution, glue, gelatin or sodium silicate. The mixture may be then mixed with another compound designed to impart phosphorescence and luminosity, said latter compound being made of the following materials, strontium carbonate 100 parts by weight, sulphur 30 parts by weight, sodium carbonate 2 parts by weight, sodium chloride 0.5 part by weight and manganese sulphate 0.2 part by weight. This latter compound is intimately combined and heated to 2372 degrees Fahrenheit for one half hour and then exposed to the phys-:

ical effects of a mercury vaporlamp. The powder which forms said latter compound may be added to 300 parts by weight of the aforesaid mixture of sodium fluorescein and titanium tetraiodide and then mixed with such vehicles as oil, soap solution, glue, gelatin, sodium silicate separately or in combination or may be used in The finished product may be comminuted or made into suitable geometrical shapes and the rate of dispersion may be controlled by the addition of retarders so as to makethe signal of longer duration.

E'luorescein and its: salts imparts: luminosity to the compound which is visiblewith: outstanding effect only during daylight and strontium imparts to the mixture outstanding luminosity at night, thus providing a combined product which produces signaling means over a body of water or other surface area during daylight and darkness. Ihe assembling of all of the ingredients prolongs the application and usefulness of the mixture.

Containers for the product may be of plastic, metal, fabric or may be made of anysubstance of animal, vegetable or mineral origin. It the signalling device is to be used on a submarine, the desired container may be equipped with a timing fuse and, a detonating device and in certain specific cases the container may be of fabric for use for plotting and marking and for other signalling purposes, such as for the use of personnel of the various types of craft, and not equipped with a time-fuze device.

A preferred type of signalling device for use on bodies of sea or fresh water by day or by night is to mould or press the foregoing composition into the desired geometrical shapes or structures, said shapes or structures being aflixed to floating devices such as cork, air-floats, kapok supporters and the like, said floating devices may also be equipped with structures calculated to act as sea-anchors to maintain more or less registration for periods of time of the area to which it is desired to direct attention.

Certain circumstances may make it necessary to employ the chemical composition of fluorescein, or sodium fluorescein separately or in combination the luminous-phosphorescent composition in a liquid base as outlined, or in a comminuted form or in the form of moulded or pressed geometrical shapes with floats suitable to the purpose attached individually or collectively.

Having now described my invention what I claim is:

l. A composition for producing visible signalling over a predetermined surface area during daylight and darkness, said composition consisting essentially of the reaction product of a mixture of approximately: parts of strontium carbonate, 30 parts of sulfur, 2 parts of sodium carbonate, 0.5 part of sodium chloride and 0.2 part of manganese sulfate, said mixture being heated to a temperature of approximately 2372 for a period of approximately 30 minutes; combined with approximately 300 parts of a mixture of approximately: 9 parts of sodium fluorescein and 1 part of titanium tetraiodide.

2. The method of forming a material for signalling over a surface area by day and at night comprising the steps of mixing the following ingredients in the approximate proportions indicated: 100 parts of strontium carbonate, 30 parts Y of sulfur, 2 parts of sodium carbonate, 0.5 part of sodium chloride and 0.2 part of manganese sulfate; heating said mixture to-a temperature of approximately 2372 F. for a period of approximately 30 minutes, activating said mixture by exposure to ultraviolet light to form a phosphorescent material and finally combining said mixture with approximately 300 parts of a mixture of sodium fluorescein and titanium tetraiodide, the latter mixture being in the proportions of approximately 9 to 1.

ALFRED DINSLEY.

REFERENCES CITED The following references'are of record in the file of this patent:

Germany Nov. 27, 1940 OTHER REFERENCES 7 20 Publication: Wiens-Harms, Handbuch Der Experimental Physik,:vol. XXIII, part 1,91 360, .361.