Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
  • H01J9/02—Manufacture of electrodes or electrode systems
  • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
  • H01J9/042—Manufacture, activation of the emissive part
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H35/00—Delivering articles from cutting or line-perforating machines; Article or web delivery apparatus incorporating cutting or line-perforating devices, e.g. adhesive tape dispensers
  • B65H35/0006—Article or web delivery apparatus incorporating cutting or line-perforating devices
  • B65H35/006—Article or web delivery apparatus incorporating cutting or line-perforating devices with means for delivering a predetermined length of tape

Definitions

• one ofthe methods used in applying the alkaline earth metal carbonates is that of spraying or painting the metal base of the cathode with a suspension of the carbonates in some volatile organic solvent or solvents in which is dissolved some binding materlal such as nitrocellulose.
• some binding materlal such as nitrocellulose.
• this organic binder is removed from the coating by heating the same .in a vacuum during the exhaust procedure in the manufacture of an electron discharge device, whereupon a bonding action is thereafter established between the coating material and the metal base by effecting decomposition of the carbonates therein and conversion to oxides which react with the surface oxides of the metal base to bond thereon.
• organic solvents such as amylacetate, butylacetate or mixtures of these solvents with'common alcohols, such as ethyl or methyl alcohol, to which have'been added the desired proportion of nitrocellulose.
• suspension material is immedlately employed when made excellent results are obtained therefrom.
• the electronic efliciencyof the cathodes prepared from the aged material decreases as the age there- Applicationfiled July 20, 1928. Serial K01 294326.
• Another object of the invention is to provide asuspension of electron emitting matrial in an organic suspending medium having substantially-all the advantages of prior suspensions and which is non-deteriorating with age to form compounds detrimental to the electronic emission of the alkaline earth metal component thereof.
• Another object of this invention is to pro- 'customary to employ as carbonate material the commercial C. P. grade of alkaline earth metalcarbonates purchasable on the market. These materials were mechancally admixed in any desired proportion andsuspended in the suspending medium (organic or inorganic) and applied in any desirable manner to the surface to be coated. In general the factor of adsorbed or absordedimpurities were not allowed for and as a consequence such 1mpurities were variable in amounts and in identity, depending upon the method of production and prior history of the particular material employed.
• these impurities which may be generally classified as being alkali metal compounds such as the chlorides, nitrates or bydroxides, etc., depending upon the general method of production lnitially employed, may deleteriously affect the operating elliciency of the hot cathode, they are not wholly responsible for. the observed loss of emission due to the aging of the organic suspension material comprising the coating, as I have determined that such a deteriorating effect is obtained when an especially purified carbonate material such as may be prepared by my copending applications Serial Nos. 292,037 and 293,801 above mentioned, is employed in the formation of such an organic sus ension.
• the solvent employed should be also readily vaporizable in air and have a reasonable solubility towards a suitable binder material such as nitrocellulose.
• a suitable binder material such as nitrocellulose.
• the organic solvents diethyl carbonate ((C H CO3) or diethyl oxalate (C O (C H are examples of organic solvents fulfilling the provisions as above noted and may be employed in forming organic suspensions of alkaline earth metal carbonates for use in coating cathode surfaces and that suspensions employing these solvents either singly or admixed in any proportion are substantially stable for prolonged periods of time and show no evidence'of deterioration or interaction of the solvent with the alkaline earth metal carbonates to yield compounds deleterious to the electron efficiency of the hot cathode prepared therefrom.
• nitrocellulose (parlodion) is placed in a glass bottle, the solvents are added and the mixture agitated until the nitrocellulose is thoroughly dissolved.
• parlodion which is a very purehigh grade commercial nitrocellulose product, the solution will perfectly clear and will not need any filtering.
• the bottle should be kept tightly stoppered. This solution will be referred to as binder solution #1.
• Carbonate mixture 100 gms. Binder solutionffirl 50 m.l. Diethyl carbonate 50 m.l.
• the time interval of the milling operation is dependent upon what use is being made of the resultant product.
• a degree of subdivision must be obtained which will permit the coating composition to flow freely through the spray orifice.
• painting and dipping operations sucha degree of subdivision is not required.
• a coating composition for use in forming hot cathodes of .the oxide coated type comprised of alkaline earth metal carbonates substantially free from adsorbed or absorbed chemical impurities, av proportion of nitrocellulose binder and diethyl carbonate as a solvent and dilutant materiaL- 2.
• a coating composition for-use in forming hot cathodes of the oxide coated class comprised of intimately admixed barium, strontium and calcium carbonates, a small proportion of nitrocellulose binder, and an organic solvent therefor comprised of one of the organic esters of diethyl carbonate and diethyl oxalate, in suflicient amount to form a suspension for said carbonates.
• a suspension. medium for alkaline earth metal carbonates for use in coatinghot cathodes of the oxide coated type comprised of approximately equal amounts of diethyl carbonate and a solution of 20% diethyl oxalate and 80% diethylcarbonate in which is dissolved a small proportion of nitrocellulose binder.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Solid Thermionic Cathode (AREA)
• Paints Or Removers (AREA)
• Discharge Lamp (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23132929

Family Applications (1)

Country Status (6)

Cited By (5)

Families Citing this family (1)

• 0
  • BE BE362221D patent/BE362221A/xx unknown
  • NL NL28930D patent/NL28930C/xx active
• 1928
  • 1928-07-20 US US294326A patent/US1842161A/en not_active Expired - Lifetime
• 1929
  • 1929-07-18 FR FR678731D patent/FR678731A/fr not_active Expired
  • 1929-07-19 DE DEW83232D patent/DE521050C/de not_active Expired
  • 1929-07-22 GB GB22507/29A patent/GB316104A/en not_active Expired

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