Nomenclature
CAS number: 13463-67-7
Titanium oxide (TiO
2); unitane; C.I. Pigment White 6; C.I. 77891.
O
2Ti; mol wt 79.87.
O 40.06%, Ti 59.93%.
TiO
2.
Description and references
Found in nature as the minerals rutile (tetragonal), anatase or octahedrite (tetragonal), brookite (orthorhombic), ilmenite (FeTiO3), and perovskite (CaTiO3). May be prepd by direct combination
of titanium and oxygen; by treatment of titanium salts in aq soln;
by the reaction of volatile, inorganic titanium compds with oxygen;
by oxidation or hydrolysis of organic compds of titanium. Industrial
prepn from ilmenite or rutile: Faith, Keyes
& Clark's Industrial Chemicals, F. A. Lowenheim, M.
K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 814-821.
Prepn of synthetic rutile: Merker, US 2760874 (1956 to National Lead). Prepn of spectroscopically pure material by dissolving titanium
in an ammoniacal soln of 90% H2O2: Czanderna et al., J. Am. Chem. Soc. 79, 5407 (1957). Comprehensive description: H. G. Brittain et al., Anal. Profiles Drug Subs. Excip. 21, 659-691 (1992).
Properties
White powder, mp 1855°. d (rutile): 4.23; (anatase): 3.90; (brookite):
4.13. Insol in water, HCl, HNO3, or dil H2SO4. Sol in hot concd H2SO4, in HF. The reactivity depends on a previous
heat treatment; prolonged heating produces a less sol material. Also
made sol by fusion with potassium bisulfate or with alkali hydroxides
or carbonates to form alkali titanates. Possesses perhaps the greatest
hiding power of all inorganic white pigments. Titania is a name applied to large TiO2 crystals (translucent
water-white or with yellowish cast) suitable for use in jewelry.
These crystals have a refractive index (2.7) higher than diamonds
(2.4), but lack the hardness of diamonds. When substantially pure,
a massive single crystal (boule) of rutile has the properties of a
precious gem with a very light straw color and with reflectance, refraction
and brilliance measuring greater than those of a diamond.Note
The rutile structure is common among
metal fluorides and oxides of the type MF2 and MO2.Caution
Potential symptom of overexposure
is lung fibrosis. Potential occupational carcinogen. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 310.Use
Airfloated ilmenite is used for titanium pigment
manuf. Rutile sand is suitable for welding-rod-coating materials,
as ceramic colorant, as source of titanium metal. As color in the
food industry. Anatase titanium dioxide is used for welding-rod-coatings,
acid resistant vitreous enamels, in specification paints, exterior
white house paints, acetate rayon, white interior air-dry and baked
enamels and lacquers, inks and plastics, for paper filling and coating,
in water paints, tanners' leather finishes, shoe whiteners, and ceramics.
High opacity and tinting values are claimed for rutile-like pigments.
Therapeutic Category
Protectant (topical); ultraviolet screen.
Keywords
Topical Protectant; Ultraviolet Screen