Mixture of metalloid oxide/metal-cerium oxide

p0001The invention relates to a finely divided cerium oxide-metal / metalloid oxide mixture, the process for their preparation and their use.

p0002The invention is a finely divided cerium oxide-metal / metalloid oxide mixture containing pyrogenically produced metal / metalloid oxide and 0.001 to 95 wt .-% cerium oxide, with a specific surface area of ​​the resulting mixture between 10 and 400 m²/G.

p0003Another object of the invention is a method for producing the finely divided cerium oxide-metal / metalloid oxide mixture, which is characterized in that pyrogenically, especially by flame hydrolysis produced metal / metalloid oxide having a specific surface from 30 to 400 m²/ G with respect to the oxide at elevated temperature decomposable cerium compound, preferably a cerium carbonate, and the cerium compound is intensively mixed, preferably thermally decomposed at temperatures between 300 and 600 ° C and at sintering times between 0.5 and 10 hours to the oxide.

p0004In a preferred embodiment of the invention can be described as at least one of fumed, prepared in particular by flame metal / metalloid oxides mix of silicon, aluminum, boron, titanium or zirconium or mixtures thereof or mixed oxides intensively with an elevated temperature to form the oxide decomposable cerium and the cerium compound thermally decomposed to the oxide.

p0005The inventive mixture may be used alone or in suspension as a polishing agent for polishing silicon wafers or other occurring in the electronics industry polishing tasks. Furthermore, they can be used as UV-absorbing filler for filling polymers.

example 1

p0006950 g of fumed silica OX 50 are 83.5 g of cerium (Ce₂(CO₃)₃X5H₂O) 30 minute intensively mixed in a Lodige mixer. The powder was then heated one hour in air at a temperature of 400 ° C. The content of cerium oxide is 5 wt .-%, the resulting BET surface area 44 m²/G.

example 2

p0007950 g of fumed silica OX 50 are 83.5 g of cerium (Ce₂(CO₃)₃X5H₂O) 30 minute intensively mixed in a Lodige mixer. The powder was then heated one hour in air at a temperature of 500 ° C. The content of cerium oxide is 5 wt .-%, the resulting BET surface area 41 m²/G.

example 3

p0008900 g of fumed silica OX 50 are with 167 g of cerium (Ce₂(CO₃)₃X5H₂O) 30 minute intensively mixed in a Lodige mixer. The powder was then heated one hour in air at a temperature of 400 ° C. The content of cerium oxide is 10 wt .-%, the resulting BET surface area 44 m²/G.

example 4

p0009900 g of fumed silica OX 50 are with 167 g of cerium (Ce₂(CO₃)₃X5H₂O) 30 minute intensively mixed in a Lodige mixer. The powder was then heated one hour in air at a temperature of 500 ° C.

p0010The content of cerium oxide is 10 wt .-%, the resulting BET surface area 42 m²/G.

p0011Analysis of the powder samples contained according to Examples 1 to 4: <tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="8" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="19.68mm" /><colspec colnum="2" colname="col2" colwidth="19.68mm" /><colspec colnum="3" colname="col3" colwidth="19.68mm" /><colspec colnum="4" colname="col4" colwidth="19.68mm" /><colspec colnum="5" colname="col5" colwidth="19.68mm" /><colspec colnum="6" colname="col6" colwidth="19.68mm" /><colspec colnum="7" colname="col7" colwidth="19.68mm" /><colspec colnum="8" colname="col8" colwidth="19.68mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">example</entry><entry namest="col2" nameend="col2" align="center">CeO₂ Wt .-%</entry><entry namest="col3" nameend="col3" align="center">Sintering temperature [°]</entry><entry namest="col4" nameend="col4" align="center">Sintering time [°]</entry><entry namest="col5" nameend="col5" align="center">Tamped density [g / l]</entry><entry namest="col6" nameend="col6" align="center">BET surface area [m²/G]</entry><entry namest="col7" nameend="col7" align="center">Loss on drying wt .-%</entry><entry namest="col8" nameend="col8" align="center">Loss on ignition weight .-%</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">1</entry><entry namest="col2" nameend="col2" align="center">5</entry><entry namest="col3" nameend="col3" align="right">400</entry><entry namest="col4" nameend="col4" align="right">1</entry><entry namest="col5" nameend="col5" align="right">139</entry><entry namest="col6" nameend="col6" align="right">44</entry><entry namest="col7" nameend="col7" align="center">0.3</entry><entry namest="col8" nameend="col8" align="char" char=",">0.4</entry></row><row><entry namest="col1" nameend="col1" align="right">2</entry><entry namest="col2" nameend="col2" align="center">5</entry><entry namest="col3" nameend="col3" align="right">500</entry><entry namest="col4" nameend="col4" align="right">1</entry><entry namest="col5" nameend="col5" align="right">143</entry><entry namest="col6" nameend="col6" align="right">41</entry><entry namest="col7" nameend="col7" align="center">0.1</entry><entry namest="col8" nameend="col8" align="char" char=",">0.2</entry></row><row><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="center">10</entry><entry namest="col3" nameend="col3" align="right">400</entry><entry namest="col4" nameend="col4" align="right">1</entry><entry namest="col5" nameend="col5" align="right">173</entry><entry namest="col6" nameend="col6" align="right">44</entry><entry namest="col7" nameend="col7" align="center">0.05</entry><entry namest="col8" nameend="col8" align="char" char=",">0.7</entry></row><row><entry namest="col1" nameend="col1" align="right">4</entry><entry namest="col2" nameend="col2" align="center">10</entry><entry namest="col3" nameend="col3" align="right">500</entry><entry namest="col4" nameend="col4" align="right">1</entry><entry namest="col5" nameend="col5" align="right">172</entry><entry namest="col6" nameend="col6" align="right">42</entry><entry namest="col7" nameend="col7" align="center">0.05</entry><entry namest="col8" nameend="col8" align="char" char=",">0.5</entry></row><row><entry namest="col1" nameend="col8" align="justify">Loss on drying (2 h at 105 ° C, in accordance with DIN / ISO 787 / II, ASTM D 280, JIS K 5101/21).</entry></row><row><entry namest="col1" nameend="col8" align="justify">Loss on ignition (2 h at 1000 ° C, in accordance with DIN 55921, ASTM D 1208, JIS K 5101/23, based on the 2 h at 105 ° C dried substance).</entry></row></tbody></tgroup></table></tables>

p0012The pyrogenic used, by flame hydrolysis of SiCl₄ produced silica OX 50 (manufacturer Degussa) has the following physicochemical characteristics: <tables id="tabl0002" num="0002"><table frame="all"><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" rowsep="0" /><entry namest="col2" nameend="col2" align="center"><b>AEROSIL OX 50</b></entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">CAS Reg number 112945-52-5 (old No .: 7631-86-9)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Resistance to water</entry><entry namest="col2" nameend="col2" align="center">hydrophilic</entry></row><row><entry namest="col1" nameend="col1" align="left">Appearance</entry><entry namest="col2" nameend="col2" align="center">loose white powder</entry></row><row><entry namest="col1" nameend="col1" align="left">BET surface area ¹⁾</entry><entry namest="col2" nameend="col2" align="center">50 ± 15</entry></row><row><entry namest="col1" nameend="col1" align="left">Average primary particle size m²/G</entry><entry namest="col2" nameend="col2" align="center">40</entry></row><row><entry namest="col1" nameend="col1" align="left">tamped density ²⁾ normal goods g / l</entry><entry namest="col2" nameend="col2" align="center">130</entry></row><row><entry namest="col1" nameend="col1" align="left">loss on drying ³⁾ (2 hours at 105 ° C) when leaving the supplier's works%</entry><entry namest="col2" nameend="col2" align="center"><1.5</entry></row><row><entry namest="col1" nameend="col1" align="left">loss on ignition ⁴⁾⁷⁾ (2 hours at 1000 ° C)%</entry><entry namest="col2" nameend="col2" align="center"><1</entry></row><row><entry namest="col1" nameend="col1" align="left">PH value ⁵⁾ (In 4% aqueous dispersion)</entry><entry namest="col2" nameend="col2" align="center">3.8 to 4.8</entry></row><row><entry namest="col1" nameend="col1" align="left">SiO₂^8th) %</entry><entry namest="col2" nameend="col2" align="center">> 99.8</entry></row><row><entry namest="col1" nameend="col1" align="left">Al₂O₃^8th) %</entry><entry namest="col2" nameend="col2" align="center"><0.08</entry></row><row><entry namest="col1" nameend="col1" align="left">Fe₂O₃^8th) %</entry><entry namest="col2" nameend="col2" align="center"><0.01</entry></row><row><entry namest="col1" nameend="col1" align="left">TiO₂^8th) %</entry><entry namest="col2" nameend="col2" align="center"><0.03</entry></row><row><entry namest="col1" nameend="col1" align="left">HCl ^8th)¹¹⁾ %</entry><entry namest="col2" nameend="col2" align="center"><0.025</entry></row><row><entry namest="col1" nameend="col1" align="left">sieve residue ⁶⁾ (According to Mocker, 45 microns)%</entry><entry namest="col2" nameend="col2" align="center"><0.2</entry></row></tbody></tgroup><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col2" align="justify">¹⁾ in accordance with DIN 66 131</entry></row><row><entry namest="col1" nameend="col2" align="justify">²⁾ in accordance with DIN ISO 787 / XI, JIS K 5101/18 (not sieved)</entry></row><row><entry namest="col1" nameend="col2" align="justify">³⁾ in accordance with DIN ISO 787 / II, ASTM D 280, JIS K 5101/21</entry></row><row><entry namest="col1" nameend="col2" align="justify">⁴⁾ in accordance with DIN 55 921, ASTM D 1208, JIS K 5101/23</entry></row><row><entry namest="col1" nameend="col2" align="justify">⁵⁾ in accordance with DIN ISO 787 / IX, ASTM D 1208, JIS K 5101/24</entry></row><row><entry namest="col1" nameend="col2" align="justify">⁶⁾ in accordance with DIN ISO 787 / XVIII, JIS K 5101/20</entry></row><row><entry namest="col1" nameend="col2" align="justify">⁷⁾ based on the 2 hours at 105 ° C dried substance</entry></row><row><entry namest="col1" nameend="col2" align="justify">^8th) based on the 2 hours at 1000 ° C calcined substance</entry></row><row><entry namest="col1" nameend="col2" align="justify">¹¹⁾ HCl content is part of the loss on ignition</entry></row></tbody></tgroup></table></tables>