Patent GB-1081931-A (GB)
Title: Fibrous alkali metal titanate
IPC: C01G23/00
Filed: 1964-05-08
Abstract: A fibrous, water-insoluble titanate of Na, K, Rb or Cs is prepared by calcining at 200 DEG  to 1150 DEG  C. a non-fluid, intimate reaction mixture of a basic oxygen-containing compound of the appropriate metal and an oxygen-containing titanium compound for a period of time sufficient to effect at least partial conversion to a titanate of the alkali metal having a TiO2/M2O ratio, where M is Na, K, Rb or Cs, of from 4:1 to 9:1 and recovering a fibrous titanate from the calcined mixture. Calcination temperatures of 200 DEG  to 850 DEG  C. yield particles of predominantly colloidal dimensions ranging from 0.005 to 0.1m  in diameter with lengths at least 10 times said diameter; calcination temperatures of from above 850 DEG  to 975 DEG  C. yield pigmentary particles with diameters ranging from 0.1 to 0.6m  and lengths from 10 to 100 times said diameter and temperatures of from above 975 DEG  to 1150 DEG  C. yield particles with diameters of 0.6 to 3.0m  and lengths of from 100 to 1000 or more times the diameter, which are useful as insulating and reinforcing material. The reaction components which may contain an alkali metal halide, are dry-blended and compacted prior to calcination in a conventional furnace.  The processes of feeding in the reaction mixture and discharging the product may be continuous.  The product is purified and the fibres exfoliated by treatment involving steps such as water or acid leaching, treatment with ion-exchange resin, flocculation and grinding.  In one embodiment purification and exfoliation are carried out by adding the discharge to the beater during a papermaking process (see Division D2).  In examples, mixtures of K2CO3, KOH, KHCO3, K2SO4, Na2CO3, NaOH or NaHCO3, together in some cases with KCl or KF, and TiO2 in anatase or rutile form or hydrous TiO2 are used to produce sodium or potassium titanates and mixed sodium and potassium titanates.ALSO:Pigmentary, fibrous, water-insoluble titanates of Na, K, Rb or Cs having a TiO2/M2O molar ratio of from 4:1 to 9:1 and prepared by calcining a mixture of a basic oxygen-containing compound of the metal and an oxygen-containing titanium compound (see Division C1) may be incorporated in paper to improve its opacity.  In examples potassium or sodium titanate or a mixed potassium-sodium titanate is incorporated in paper, e.g. magazine print, for instance by mixing the titanate, and in some cases TiO2, with a sulfite pulp-water slurry in a beater, adding starch solution and alum, proportioning the resulting slurry and sheeting it.  Alternatively, a fibre-starch coating may be applied to paper during the drying.ALSO:A fibrous, pigmentary, water-insoluble titanate having a TiO2 = M2O molar ratio (M being sodium, potassium, rubidium or caesium) of from 4:1 to 9 = 1 and consisting predominantly of particles with diameters of 0.1 to 0.6 microns and lengths from 10 to 100 times the said diameter, is prepared by calcining at a temperature from above 850 DEG C. up to 975 DEG C. a non-fluid mixture of a basic oxygen-containing compound of Na, K, Rb, or Cs and an oxygen-containing titanium compound and is employed in compositions for coating paper and folding boxboard. For instance, in the latter application the composition comprises the titanate pigment and starch.