Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
  • C03C8/02—Frit compositions, i.e. in a powdered or comminuted form
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
  • C03C8/02—Frit compositions, i.e. in a powdered or comminuted form
  • C03C8/04—Frit compositions, i.e. in a powdered or comminuted form containing zinc
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
  • C03C8/02—Frit compositions, i.e. in a powdered or comminuted form
  • C03C8/10—Frit compositions, i.e. in a powdered or comminuted form containing lead
  • C03C8/12—Frit compositions, i.e. in a powdered or comminuted form containing lead containing titanium or zirconium
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2207/00—Compositions specially applicable for the manufacture of vitreous enamels
  • C03C2207/08—Compositions specially applicable for the manufacture of vitreous enamels for light metals

Definitions

• This invention relates to new non-toxic aluminum 0.1% byz weigh t M116 enamel frits. More particularly, it relates to the forma- 1% by weight o tron on aluminum and aluminum alloy articles of hard 05% by weight p o vitreous enamel coatings which will be non-toxic in use, 10% by weight o and 1111912 certfain improved novel vitreous enamel frits to 43% b weight 1:0
• Table 3 discloses t er o 16:t o 0 5 a F weight percent composition of batches for the production factory Qlethod of enamellflg alumfnum and a-hfmlnum of the respective enamel frits shown in Tables 1 and 2.
• alloys Wlth such 5 9 11911401510 enamel
• other suitable batch compoother oblwts 0f mvelftlon W111 pp herfilnaftelfi 5 sitions may be used in making the respective frits of Ta-
• the objects of th1s mvent1on may be aecompllshed by bles 1 and 2, the raw materials being calculated to yield. the preparation of a non-toxic, substantially lead-less the desired frit composition.
• the aluminum article is immersed in this bath, heated to a temperature of 60 C., for a period of two to ten minutes.
• the pretreated surface is then preferably fired for a period of two to thirty minutes at a temperature between 480 C. and 580 C.
• the optimum conditions as white or colored pigments, opacifying agents, or the of chromate pretreatment and firing will depend largely upon the composition of the aluminum alloy to be treated. In the case of any particular aluminum alloy, it can readily be determined whether or not sufficient enamel adherence to insure against water-spalling is obtained by is can be determined by means of the following accelerated test which correlates with water exposure results which may take weeks or months.
• This accelerated test consists in chromale-treating and enameling pieces of the particular alloy
• Such vehicles are, for exto be tested, and then exposing the enamel-metal interface by gouging, filing, or scratching the same, and immersing the test sample in 5% aqueous ammonium chloride solution for ninety-six hours at room temperature. If no failure occurs back one-ei hth inch from the enameled are first cleaned, if necessary, by treatment edge of the exposed interface, excellent performance in water exposure will result from the chromate treatment and enameling conditions used. The particular optimum treatment and enameling conditions for a specific alloy can thereby be established.
• chromate prefarably above about 10%, ex-
• the followhromate pretreatment has been found very satisafew percent of the rr Sh d rc Pd 6 .5 m m m mm b 2 M S r m O S a f m u u e w e m o s 0 m1 t m m o l.m m m s 0 s no. at 11 0 e a m :7 e U f.
• the firing conditions are not critical, except that the article must be brought to a temperature high enough to melt the enamel but not so high that the metal article will be injured.
• the temperature necessary de pends to some extent on the particular aluminum alloy being enameled and upon the particular enamel composition being used. It is not generally necessary to employ'a temperature above about 550 C. and, inmost cases, the enamel may be satisfactorily fused at a temperature between 490 C. and 550 C. It is merely necessary to keep the article a t'the selected temperature for a few minutes to permit the enamel to fuse completely to a uniform, adherent, vitreous layer. Several coats may be applied, if desired.
• the enamels of this invention have surprisingly low fusion points despite the fact that they do not contain any substantial quantity of lead. Moreover, these enamels have a degree of resistance to chemical agents which was not believed possible for a substantially lead-free enamel.
• enamels adhere exceedingly well to aluminum or aluminum alloy surfaces even when exposed to thermal shocks or considerable mechanical flexing of the metal.
• the following examples are given to illustrate certain preferred procedures for the enameling of aluminum and aluminum alloys.
• Example I Aluminum alloy sheet stock composed of aluminum alloy 61 (containing, by weight, 0.25% copper, 0.6% silicon, 1.0% magnesium, and 2.5% chromium) is immersed for two minutes in a bath heated to 60 C. and consisting of the following:
• the liquid and solid contents of the slurry are mixed in such proportions that the sheet after dipping in the slurry and draining will contain approximately 0.5 gram per square inch of surface.
• the enamel is fired at a temperature of 500 C. for nine minutes.
• the resulting enamel will have optimum properties; for example, it will be glossy and of a pleasing white color, which will adhere tenaciously to the substrate in life testing and in accelerated testing and it will be substantially unaffected by 10% citric acid in fifteen minutes, and will resist indefinitely the attack of a 10% household detergent solution at boiling temperature.
• Example II The process of Example I was repeated using a chromate pretreatment solution containing and the use of a frit having the following composition:
• Example I The other conditions of Example I were followed as set forth in that example. The results were approximately identical to the results therein set forth.
• a non-toxic vitreous enamel frit having a maturing temperature of 490 C. to 550 C. suitable for the enameling of aluminum and aluminum alloys at least 70% of which consists of 22% to 35% TiO, by weight 14% to 29% SiO, by weight 17% to 26% Na,0 by weight 1% to 3% Li 0 by weight said frit containing less than 0.1% NiO by weight 0.1% MnO by weight 1.0% C00 by weight 4.0% A1 05 by weight 11.0% 13,0, by weight 2.0% ZnO by weight 30.0% BaO by weight 4.0% CaO by weight 4.0% ZrO, by weight 0.5% PbO by weight 11.0% K 0 by weight said frit consistingvessentially of the above-named ingledients, all of which are melted together to form the 2.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Glass Compositions (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (4)

Cited By (8)

Citations (4)

• 0
  • BE BE570850D patent/BE570850A/xx unknown
• 1957
  • 1957-01-07 US US632662A patent/US2911312A/en not_active Expired - Lifetime
• 1958
  • 1958-01-06 GB GB474/58A patent/GB824527A/en not_active Expired
  • 1958-01-07 FR FR1197756D patent/FR1197756A/fr not_active Expired

Patent Citations (4)

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