Zirconium dioxide powder, method of its production and use

Details Zirconium dioxide powder, method of its production and use Zirconium dioxide powder, method of its production and use

1998-04-29

2003-02-25

Bos, Steven (Department: 1754)

Chemistry of inorganic compounds

Oxygen or compound thereof

Metal containing

Reexamination Certificate

active

06524548

ABSTRACT:

The present invention relates to a zirconium dioxide powder, the method of its production and its use.
Zirconium dioxide powder can be used in very different areas such as e.g. electronics, ceramic components, fireproof materials and catalysis.
It is known that zirconium dioxide powder can be produced by flame hydrolysis (DE 36 11 449). The known zirconium dioxide powder has a surface area of 104 m
2
/g and a chloride content of 2.66% by weight.
The known zirconium dioxide powder has the disadvantage that it tends to cake in the flame reaction tube during production and therefore causes undesired interruptions of the operation.
An object of the present invention is to produce a zirconium dioxide powder not having these disadvantages.
SUMMARY OF THE INVENTION
In achieving the above and other objects, one feature of the present invention is a pyrogenically, especially flame-hydrolytically produced zirconium dioxide powder which is characterized in that the specific surface area of the zirconium dioxide range from 20 to 200 m
2
/g, the primary particles, which may be coalesced to each other, range from 7 to 100 nm in size, the tamped density of the deacidified and non-deacidified zirconium dioxides range from 40 to 150 g/l, the Sears numbers of the deacidified and non-deacidified zirconium dioxides range from 1 to 20 ml/2 g and the chlorine content of the deacidified zirconium dioxides is less than 0.6% by weight. The Sears number of the zirconium dioxide is the same as the range discussed above regardless of whether the zirconium dioxide is in the deacidified or the non-deacidified state.
In particular, the zirconium dioxide powder of the present invention can have the following physico-chemical characteristic data:
ZrO
2
(% by weight)
96-100
HfO
2
(% by weight)
 4-0
Chlorine content
 2-4
non-deacidified (% by
weight)
Chlorine content deacidified
<0.6
(% by weight)
Specific surface area
20-200
(m
2
/g)
Primary particle size (nm)
 7-100
Tamped density of the
40-150
deacidified and non-
deacidified zirconium
dioxide (g/l)
Crystal phase of the non-
tetragonal and cubic,
deacidified zirconium
small amount monoclinic
dioxide
Crystal phase of the de-
monoclinic and tetragonal
acidified zirconium
dioxide
Sears number of the de-
 1-20
acidified and of the non-
deacidified zirconium
dioxide (ml/2 g)
In accordance with another feature of the invention, the method of producing the pyrogenically, especially flame-hydrolytically produced zirconium dioxide powder is carried out starting with zirconium halides, preferably the chloride, which is evaporated, the resulting vapor is mixed alone or together with a carrier gas, e.g. nitrogen, in a mixing unit in a burner with other gases; i.e. air, oxygen, nitrogen and hydrogen. The gases are caused to react with each other in a flame in a closed combustion chamber to produce the zirconium dioxide and waste gases. Then the hot waste gases and the zirconium dioxide are cooled off in a heat-exchanger unit, the waste gases are separated from the zirconium dioxide and any halide remnants adhering to the zirconium dioxide obtained are removed by a heat treatment with moistened air.


REFERENCES:
patent: 2762688 (1956-09-01), Wainer
patent: 2823982 (1958-02-01), Saladin et al.
patent: 3419351 (1968-12-01), Zirngibl et al.
patent: 3663283 (1972-05-01), Hebert et al.
patent: 3954945 (1976-05-01), Lange et al.
patent: 4048290 (1977-09-01), Lee
patent: 4083946 (1978-04-01), Schurr et al.
patent: 4292290 (1981-09-01), Tunison
patent: 4360598 (1982-11-01), Otagiri et al.
patent: 4520114 (1985-05-01), David
patent: 4591471 (1986-05-01), Hori
patent: 4946665 (1990-08-01), Recasens et al.
patent: 5011673 (1991-04-01), Kreichbaum et al.
patent: 5155071 (1992-10-01), Jacobson
patent: 5358695 (1994-10-01), Helble et al.
patent: 5391362 (1995-02-01), Reinalda et al.
patent: 5447708 (1995-09-01), Helble et al.
patent: 5472477 (1995-12-01), Koenig
patent: 2153671 (1973-05-01), None
patent: 3115002 (1982-02-01), None
patent: 3611449 (1987-10-01), None
patent: 4214719 (1993-11-01), None
patent: 241 647 (1987-10-01), None
patent: 1003957 (1965-09-01), None
patent: 60-096 529 (1985-05-01), None
patent: 61-111 919 (1986-05-01), None
patent: 3-232724 (1991-10-01), None
Brockhaus ABC Chemie, 1965, pp. 1571-1572, No month.
Roempp Chemie Lexikon, Falbe, et al., pp. 5155-5157, 1992, No month.
Lexikon der Hilfsstoffe fuer Pharmazie, Kosmetik und angrenzende Gebeieite, 1989, Dr. Her Fiedler, pp. 1367-1368, No month.

Affiliated with

Also associated with

Rating

Zirconium dioxide powder, method of its production and use does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Zirconium dioxide powder, method of its production and use, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zirconium dioxide powder, method of its production and use will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3176349