Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
98 words
A cerium containing precipitated silica having the following physico-chemical properties: ______________________________________
BET-surface area according
to DIN 66 131 m.sup.2 /g
140 ± 40
Loss on drying according
to DIN 55 921 Wt.-% 2.0-4.0
Loss on ignition according
to DIN 55 921 Wt.-% 2.5-12.5
pH-according to DIN 53 200 3.0-7.0
Conductivity in 4% aqueous
dispersion at 20° C.
μs 500
Packed density according
to DIN 53 194 g/l 80 ± 40
CeO.sub.2 -content, based on the
material dried for 2
hours at 105° C.
Wt.-% 0.3-50
Sieve residue according
to Mocker 45 μm
(DIN 53 580) Wt.-% 0.2
______________________________________
Claim 2
Dependent Claim
98 words
A cerium containing precipitated silica having the following physico-chemical properties: ______________________________________
BET-surface area according
to DIN 66 131 m.sup.2 /g
140 ± 40
Loss on drying according
to DIN 55 921 Wt.-% 2.0-4.0
Loss on ignition according
to DIN 55 921 Wt.-% 2.5-12.5
pH-according to DIN 53 200 3.0-7.0
Conductivity in 4% aqueous
dispersion at 20° C.
μs 500
Packed density according
to DIN 53 194 g/l 80 ± 40
CeO.sub.2 -content, based on the
material dried for 2
hours at 105° C.
Wt.-% 0.3-50
Sieve residue according
to Mocker 45 μm
(DIN 53 580) Wt.-% 0.2
______________________________________
Claim 3
Dependent Claim
103 words
A cerium containing precipitated silica according to claim 1 having the following physico-chemical properties: ______________________________________
BET-surface area according
to DIN 66 131 m.sup.2 /g
140 ± 40
Loss on drying according
to DIN 55 921 Wt.-% 2.0-4.0
Loss on ignition according
to DIN 55 921 Wt.-% 4.0-7.0
pH-according to DIN 53 200 3.5-7.0
Conductivity in 4% aqueous
dispersion at 20° C.
μS 500
Packed density according
to DIN 53 194 g/l 75 ± 25
CeO.sub.2 -content based on the
material dried for 2
hours at 105° C.
Wt.-% 10-20
Sieve residue according
to Mocker 45 μ m
(DIN 53 580) Wt.-% 0.2
______________________________________
Claim 4
Dependent Claim
132 words
A process for producing the cerium containing precipitated silica of claim 1 comprising simultaneously adding a water glass solution and acid to water having a pH-value of 7 to 9 in a container at a temperature above 50° C. and up to the boiling point of the reaction mixture while employing shearing forces and holding the pH-value constant at 7 to 9 during a time span of 80 to 120 minutes, whereby after the termination of the precipitation there is present a pH-value of 7 to 9 in the reaction mixture, adding to the thus obtained precipitated silica original suspension and aqueous cerium (IV) salt solution adjusting the now acid reaction mixture to a pH-value of 6 to 8, washing the thus obtained cerium containing precipitated silica with water, drying and grinding.
Claim 5
Dependent Claim
58 words
A process according to claim 3 wherein the pH-value of the water originally present in the container is adjusted to the pH-value of 7 to 9 with a water glass solution having a mole ratio of SiO 2 :Na 2 O=1:3.46 and a content of 26.8 weight % SiO 2 and 8.0 weight % of Na 2 O.
Claim 6
Dependent Claim
22 words
A process according to claim 4 wherein the acid employed in sulfuric acid having a concentration of 50 to 96 weight %.
Claim 7
Dependent Claim
20 words
A process according to claim 5 wherein the aqueous cerium (IV) salt solution is a Ce(SO 4 ) 2 solution.
Claim 8
Dependent Claim
24 words
A process according to claim 6 wherein the cerium salt solution is a solution of cerium (IV) sulfate.4H 2 O saturated at 20° C.
Claim 9
Dependent Claim
22 words
A process according to claim 3 wherein the acid employed is sulfuric acid having a concentration of 50 to 96 weight %.
Claim 10
Dependent Claim
23 words
A process according to claim 3 wherein the acid is sulfuric acid, nitric acid, phosphoric acid, carbonic acid, formic acid or acetic acid.
Claim 11
Dependent Claim
24 words
A process according to claim 3 comprising fluidizing the cerium containing precipitated silica filter cake using shearing forces and then spray drying and grinding.
Claim 12
Dependent Claim
24 words
A process according to claim 10 wherein the cerium salt solution is a solution of cerium (IV) sulfate.4H 2 O saturated at 20° C.
Claim 13
Dependent Claim
24 words
A process according to claim 3 wherein the cerium salt solution is a solution of cerium (IV) sulfate.4H 2 O saturated at 20° C.