DE2261579A1 - HUMIDITY INDICATOR FOR PHOTO FLASH LAMPS AND PHOTO FLASH LAMP EQUIPPED WITH IT - Google Patents

Description

Patent Attorneys 15, Dec. J972

DR. CLAUS REINLÄNDER "" DiPL-ING. KLAUS BERNHARDT D-8 MÖNCHEN 60 S6 Pi 55 D THEOOOR-STORM-STRASSE 13 «

GTE Sylvania Incorporated

Wilmington, Delaware

V.St, ν. America

Moisture inclator. for photo flash)! uni so equipped Potobli'calnmpo

Priority 2}. Dessamber 1971 - USA - Serial No. 211

summary

Ea becomes a photoflash with a moisture indicator described, which consists of a patch of dry paste which is placed on the inner surface of the hermetically sealed lamp bulb » is to detect the presence of air pollutants by changing the color. indication. The paste consists of a mixture of cobalts Cobalt cyanide and a binder made from partially hydrolyzed Polyvinyl alcohol.

Background of the invention

The invention relates generally to the production of photoblite lamps and similar devices with a tight bulb, and in particular the placement of a device for determining the presence of air pollution therein.

309826/0178

Photo flash lamps generate their actinic light through the Combustion of an enerßiereicben fuel, approximately finely zerspantoe Zirconium or aluminum, in a combustion-promoting gas, for example Oxygen. The vessel or flask for such a combustion must be transparent and muse hermetically sealed so that a The selected atmospheric exposure is present under a selected stoichiometric ratio. Such lamp bulbs exist generally made of glass, "cracked or some other defect in the The piston destroys the hermetic seal and the resulting air pollution has an unfavorable effect on the light tetrom and the time characteristics of the flash lamp. Accordingly, ea is at It is common practice in the manufacture of photo flashes to place a patch of moisture-indicating material on the inner surface of the bulb to be attached, with the change in color to indicate whether the hermetic seal is intact or not. For this purpose, cobalt-cobalt iyanide is generally used, which is in the anhydrous state is blue and turns pink when hydrated. The air vapor normally present in the air causes the color to change Blue to pink spot when the hermetic seal of the lamp envelope is broken.

Cobalt-Cobalt Cyanide is a fine, water-insoluble powder. Around a layer of this material on the inner surface of the vitreous Biital lamp bulb »to bring it up, it is necessary to put it in connection to use with a binder. Currently in use · Binders mainly include tloral, colloidal ragnesluasilicate and barium chloride. Each of these substances has one or more disadvantages. Natural products via animal glue vary considerably in their eggs. sohaft of one product! onsoharg · sur another. Animal glue gelled sometimes, is subject to bacterial spoilage and does not adhere firmly to glass. Machined zircon is abrasive like steel wool. Fleeken are often when the chips are introduced into the lamp ο from the Glass wall scraped off. Salts, such as üariuoi or strontium chloride, result soft, slightly absurd spots. The low viscosity of fleece-forming liquids using salts as a binding " medium allows the cobalt-cobalt cyanide to settle quickly, ao that gertthrt are constantly buss. Colloidal magnesium 11icate

109826/0879

sticks very feet to Glaa and produces abrasion-resistant stains. The high grade of the thixotropic that is produced in such stain-forming liquids, however, makes use of the application of a thin layer in lamp bulbs small diameter almost impossible, so this is undesirable Way results in a thick stain deposit that dries very slowly.

Despite these recognized drawbacks, some of these binders have been used with kolbaite cobalt cyanide for years to a large extent in many commercially available photoflash lamp types because it has been determined that this is the case with relatively large lamp bulbs, in which aluminum is used as a «burning» substance is used and the gas filling pressure is below atmospheric pressure, many of these disadvantages can be tolerated. Next, I showed colloidal fagnesium silicate as a useful binder in larger quantities Filled lamps in the range of bulb sizes smaller than each 10 cn volume. The relatively large piston volume and that of these Lamps used manufacturing proaasse made sure that Thixotropic Froblea had little Polgen "

Recently, however, the trend in flash lamp industry has been to use gub miniature lamps with a bulb volume of less than 1 ce ³ . Such sub-miniature bulbs are currently being mass-produced in large quantities for use in small blitilampan units called lightning cubes. In order to achieve the desired luminous flux values, these lairms are tightly packed with machined zirconium foil and filled with oxygen under a pressure that is many times higher than atmospheric pressure. In the presence of the considerably increased abrasive effect of the zircon, which is aggravated by the thick packing of the foil, the main parts of animal glue and arium chloride can no longer be tolerated.

3 high degree of thixotropic found in staining liquids containing colloidal magnesium silicate is discontinued particularly difficult problem with regard to the division of subminiature 1 amps. First of all, it is very difficult to obtain the resulting thickness To apply paste evenly on the inner surface of the sub-miniature flask «Usually the stain is applied in a

3Q9826 / Q873

Wire cintauche took is used, which is first immersed in the fleok-forming liquid and then inserted into the glass flask in order to deposit a Pleok of the display oaste on its inner side. Kit of a staining liquid that contains a binier made of colloidal magnesium silicate, however, makes the fast on aim Tauohatock so thick due to the rapid evaporation that it is immediately, if not even impossible, to insert the fauchetock loaded with paste into the very small opening of the sub-miniature glass box without smearing. Other methods of applying the stain have been tried unsuccessfully. Second, if, after significant difficulty, patches are deposited on the bulb, the patches dry unacceptably slowly because of their thickness and are therefore incompatible with the drying times and processes available on high-speed automatic manufacturing machines used in the manufacture of sub-miniature lamps , -eitor, the exchange of air in such small lamp bulbs is so small that drying problems are avoided. Accordingly, fleece-forming liquids on the basis of colloidal magnesium silicate in sub-millimeter Canz glass flasks are not used.

r enfaaaun / i the S

It is therefore an object of the invention to make available a better moisture indicator for photo flash lamps.

In particular, the invention aims to provide a better binder for a Blitzlaepen moisture indicator can be made available that more firmly adheres to the glass and greater fleok integrity and stronger / ibriebwideratand promotes, so that sin more satisfactory and previously * casual air penetration indicator for flash lamps under higher «al a Atmospheric pressure results in which zirconium ala fuel filling / is used will.

conductor coil, a better humidity control system for photo flash lamps can be made available that is compatible with high-speed automatic sub-miniature flash lamps.

3Q9826 / 087 »

These and other objects, advantages and features are achieved according to the principle of the invention by using partially hydrolyzed grades of polyvinyl alcohol as binders for peuohtiskeitaansseigeileckan in flash lamps. Se. has been featured that these Harass provide excellent stain adhesion and abrasion resistance with calibration and are available in a number of quality ranges, which allow staining liquids to be adjusted to any desired viscosity and solids content, polyvinyl alcohol solutions have excellent pigment sues pens ione aftercare and, Since they are not thixotropic, they allow Fleokan to be applied in a controlled layer thickness. In this way, realistic drying times can be achieved, and the fleokbildende liquid remains for Tauchstook deposition on the inside of Bubainiaturlampenkolben bra _u ohbar. The level of adhesion and abrasion resistance achieved by using partially hydrolyzed polyvinyl alcohol was not achieved by any other material tested.

The invention will be explained on the basis of the * drawing nfihex *} show it », ■

Fig. 1 is a side view of an electrical sensing photoflash lamp ait a · «moisture level indicator according to the invention! and

Fig. 2 shows a sonitt by a mechanically igniting flash lamp with a “moisture indicator according to the invention.

In neohaniach old, they teach inventions aind »ovohl also electrically many sizes and shapes can be used to ignite photo flashlights that Invention, however, is especially advantageous for flashlights with a Colon volume smaller than 1 approx *. Accordingly, beige pign. 1 and 2 Flash lamps that can be ignited electrically or mechanically.

The electric flash lamp to be ignited is shown in FIG. 1 made of flinea hermetically sealed, translucent lamp bulbs 2 O las tube with a Ciueiaohfuen 4 at one end and an Äbaeugröhrohen 6 at the other end. The 4uet «ohfuea 4 hits an ignition device,

di.s axis consists of two leads, "SdrähtGn θ and 10, which pass through and are tightly inserted into them. A wire 12 spans the inner ends of the lead wires, and beads 14 and of ignition material are on the inner ends of the lead wires 6 or 10 arranged at their connection to the wire. Typically, the lamp bulb 2 has an internal diameter of less than 12.5 mm (1/2 ") and an internal volume of less than 1 cm. Its quantity of threadlike fuel / like machined zirconium foil is placed in lamp bulbs. The piston 2 is also provided with a filling of combustion-promoting gas * for example oxygen, at a pressure of several atmospheres. Preferably the fuel and the combustion-promoting gas are essentially in etoichometric equilibrium.

The mechanically ignited flashlamp shown in Fig. 2 consists of a piece of glass tube that forms a hermetically sealed lamp envelope 22 which is contracted at one end to form a suction tube and is shaped to form a seal 26 around an igniter 28 forms at the other end. The igniter 28 consists of a metal tube 30, a wire anvil 32 and a charge of ignition material 34 · Sin fuel such as filamentary zirconium 36 and a combustion-promoting gas such as oxygen are accommodated in the lamp envelope, as described for the lamp to be ignited electrically. The wire anvil 32 is centered in the bore y) and is held in place with a circumferential indentation 38 de ti tubes β which laps over the head 40 or some other suitable projection at the lower end of the wire anvil. Additional devices, such as tails 42 on wire anvil 32, for example, can also be used to stabilize the wire anvil by supporting it coaxially in the igniter tube 30 and ensuring a higher clearance between the explosive 34 and the inner wall of the tube 30. A heat-resistant bead 44 is melted onto the wire anvil 32 just above the inner termination of the detonator tube 30 to eliminate burnout and act as a deflector to deflect and control the discharge of hot particles of the explosive from the detonator. The lamp according to Flg. 2 is typically also a sub-miniature lamp, the bulb-shaped shafts of which are similar to those of the lampa according to FIG.

309626/0879

i.'enn also the lamp according to Pig. 1 is electrically ignited, usually from a battery, and the lamp according to FIG. 2 can be ignited mechanically, the lamps are nevertheless similar in that their "ignition" device is arranged at one end of the lamp envelope and in operational relationship with respect to the fadenförmi -en fuel is arranged. More specifically, the ignition wire 12 of the flash lamp of Fig. 1 is electrically through through the lead wires 8 and 10 and through the current flowing through the metal wire is made to glow electrically, thereupon the glowing wire ignites the ignition beads 14 and 16, and these in turn ignite the fuel 16, which is ignited in the lamp bulb is arranged. The operation of the mechanically ignited flash lamp after Fig. 2 is initiated by a blow on pipe 30 in order for it to cause the material 34 to be thrown through the tube so that the fuel 36 is ignited within the lamp envelope.

In the manufacture of flash lamps of the type just described, the lamp bulb 2 or 22 is initially a piece of glass tube which is open at both ends. In the normal sequence of operations, the Contact structure, consisting of filament 12 and lead wires B and 10, or the igniter 28, in one of the open ends of the glass tube arranged, and the seal 4 or the seal 26 is formed, so that one of the open ends of the pipe is closed * 3s then a suitable applicator into the other open end of the tube used to put a moisture indicator spot on the inner wall to be applied, which is designated in Fig. 1 with SO and in Fig. 2 with 21. Thereafter, the paste fleok 20 or 21 is dried, and a load Fuel, in this case chipped zircon foil, is put into the still open · end of the pipe inserted. The jar is then on open ! 3 ends contracted, and the flask is pumped empty, with oxygen » gas filled under several atmospheres pressure and melted at 6, to obtain a hermetically sealed piston. Then the stain of dry paste 20 or 21, which normally looks blue, appears in such a way that, by changing color to pink, it indicates the presence of an air leak in the flask.

The flash lamp shown in Fig. 2 is in the Handel ale type ΙΌ-1 and used in mechanically igniting lightning cubes as described in US Pat. No. 3,597,604. That

309826/0879 ... / 8

-B-

The lamp bulb volume of a KC-1 is about 0.68 cn, the gas pressure

at about 550 cm iueckeilbfraäule, and the? tight machined zircon foil, »It of the lamp int provided tetrftgt about 29"& rro cm ^v olbenvolun> s.

According to the invention, the dry paste of the moisture indicator patch 21 consists of a mixture of kolbaite cobalt cyanide and a binder made from partially hydrolyzed polyvinyl alcohol. When used in tauaendsn of lamps of type PC »1 this mixture has excellent properties« Shafts shown in terms of peck adhesion and abrasion resistance. Ba the partially hydrolyzed varieties of polyvinyl alcohol are commercially available in a range of viscosity ranges, is a great flexibility in the choice of the solids content and the Viscosity of the recipe for the staining liquid possible that is made by stirring the mentioned Kisehung in Waeeer. the Polyvinyl alcohol solutions show excellent pigment suspension and are not thixotropic. Accordingly, the use of partially hydrolyzed olevinyl alcohol ale binders for the moisture indicator borrows from the diving method Fleece application can be adjusted, allowing stains to be more controlled To apply layer thickness and thus enables realistic drying times.

Polyvinyl alcohol is obtained by hydrolytic removal of acetyl groups from polyvinyl acetate. Two types of polyvinyl alcohol are commercially available fully and partially hydrolyzed · grades. ⁷ HeI the fully hydrated varieties have 97 or very few of the axetyl groups removed, while the partially hydrolyzed varieties retain between 10 ^ and 20, j of the β ty! Groups. The fully hydrolyzed types of polyvinyl alcohol give good stain adhesion and good abrasion resistance, but the completely dry stain is less sensitive to moisture. For these reasons, in previous studies to determine a better binder for use in moisture indicators for photo flash pens, polyvinyl alcohol was rejected as unsuitable for this application. Cement "was speaking it could be eusserordentlich surprisingly, found that the partial hydrolyeierten ropes of lolyvinjlalkchol awarded Bindeinlttel Fuei tm Feuchtl ^ Kej tsindikatoimaterial suitable} are these spesiell ^ n pies polyvinyl Iringen not only the beechrietenen advantage" all tirh sondezn in

dung in göalsnetöü Cjua "*;! el innovations as Siftdöiaittöl the iskeite & nseigende Suotfehs'axt a .Bifljifindliohkeit works _t - 'comparable' best ^ known of de * R & äöpte ^'is';

V / eitsra all possible indicators for ability-indicating spots investigated substances are for example HydroxyäthylaallüToseV Hydroxy * propylcellu} .oae »Carbxymethylceliulose, FoIy- (ethylene oxide) * taid folyvinylpyrolidone. None of these substances even comes even close the degree of adhesion and abrasion resistance due to polyvinyl alcohol is achieved »Sinige substances would be sufficient feuchteödurehlHaelg, among other things, to maintain good pleck sensitivity.

For example, it has been found that a very satisfactory / moisture indicator can be obtained by combining a mixture of about 10 percent by weight partially hydrolyzed polyvinyl alcohol and 90 percent by weight Kolbalt ^ cobalt eyanide in a suitable carrier such as WaEaer. Ee is stirred sufficiently Wasaer in die'Mischung _f to the desired FeatkiSrperprb »· zentaatz get au * The Tiskosität is Di9 Sortedespartiell hydro-profile Polyvinylalköhol-Haraes and the relative Waasermenge controlled. A resin which gives a viscosity of about 4 ^ 6 'ceritipoly when diluted to about 4 percent by weight in water is satisfactory.

The partially hydrolyzed «polyvinyl alcohol can be roughly between Make up 1 percent by weight and 20 percent by weight of the dry stain. Or rather low values reduce the adhesion and Specklessness, while at high binder contents the pecker is sensitive falls off quickly.

.. , ./Patentniiapriiche

Claims (5)

Claims f 1.) l Moisture indicator for inclusion in the tight flask a "^ --- ^ Laope to indicate the presence of air in it, consisting of a mixture of a substance which shows a change in color when it changes from anhydrous state to an aqueous one State passes, in particular cobalt cobalt iyanide, and a binder, characterized by the fact that the binder is partially hydrolyzed polyvinyl alcohol. 2.) Moisture indicator naoh claim 1, daduroh marked . that the mixture contains about 1 weight percent to about 20 weight percent partially hydrolyze polyvinyl alcohol. 3.) Peuohtigkeitsindikator naoh claim 1 or 2, characterized by the fact that the mixture consists of about 90 percent by weight of cobalt-cobalt cyanide and about 10 percent by weight of partially hydrolyzed polyvinyl alcohol. 4.) Feuohtigkeitsindikator according to claim 1, 2 or 3 · characterized in that the partially hydrolyzed polyvinyl alcohol is a type which gives a viscosity of about 4 * 6 centipoie when diluted to about 4 percent by weight in water. 5.) Flash lamp, consisting of a hermetically sealed light-permeable flask, a Pengs thread-like fuel in the flask, a combustion-promoting gas in the flask, and an ignition device, which is arranged in the flask in operational relation to fuel, yekennzalehnet by a moisture indicator after a of the preceding claims. JUUü2ö / Üü79 6 ") luitz lamp according to Anapruoh 5" fl & fl uiOh indicated that the flask volume is smaller than about 1 cm and the flask is filled with oxygen gas at a pressure above atmospheric pressure, and that the fuel consists of chips of chipped zirlconium foil and the like Weight per unit flask volume is greater than about 25 mg per cm 3 0 S β 2 6 / Ö f? Blank page