Barium sulfate, process for its preparation, and its use
OwnerDjamschid Amirzadeh-Asl, Karl-Heinz Schwarzinventors
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Abstract
Barium sulfate particles having an average particle diameter d50 of from 0.1 to 10 μm which are produced by precipitation can be dispersed better if they are covered with at least one organic additive.
Claims11
Barium sulfate having an average particle diameter d50 of from 0.1 to 10 μm, precipitated by mixing of barium- and of sulfate-containing solution, characterised in that the barium sulfate particles are covered with at least one organic additive, the organic additive being selected from one or more of the substances or groups of substances:
- carboxylic acids, soaps, metallic soaps, alcohols;
- polyhydric alcohols, such as pentaerythritol, neopentyl glycol and trimethylolpropane;
- polyalcohols, such as polypropylene glycol and polyethylene glycol;
- organic esters, such as neopentyl glycol dibenzoate;
- silanes, siloxanes, silicone oils, organic sulfones corresponding to the formula RSO2R, organic ketones (R—(C═O)—R), organic nitrites (RCN), organic sulfoxides (R2—SO2), organic amides (R—(C═O)—NR′R or R—(S═O)—ONR′R).
Process for the preparation of barium sulfate having an average particle diameter d50 of from 0.1 to 10 μm and precipitated by mixing of barium- and of sulfate-containing solution, characterised in that the separated filter cake is processed to form a paste, the paste is homogeneously mixed with organic additive and then dried, the organic additive being selected from one or more of the substances or groups of substances:
- carboxylic acids, soaps, metallic soaps, alcohols;
- polyhydric alcohols, such as pentaerythritol, neopentyl glycol and trimethylolpropane;
- polyalcohols, such as polypropylene glycol and polyethylene glycol;
- organic esters, such as neopentyl glycol dibenzoate;
- silanes, siloxanes, silicone oils, organic sulfones corresponding to the formula RSO2R, organic ketones (R—(C═O)—R), organic nitriles (RCN), organic sulfoxides (R2—SO2), organic amides (R—(C═O)—NR′R or R—(S═O)—ONR′R).
Process for the preparation of barium sulfate having an average particle diameter d50 of from 0.1 to 10 μm and precipitated by mixing of barium- and of sulfate-containing solution, characterised in that the separated filter cake is suspended in water, the suspension is mixed with organic additive and then dried, the organic additive being selected from one or more of the substances or groups of substances:
- carboxylic acids, soaps, metallic soaps, alcohols;
- polyhydric alcohols, such as pentaerythritol, neopentyl glycol and trimethylolpropane;
- polyalcohols, such as polypropylene glycol and polyethylene glycol;
- organic esters, such as neopentyl glycol dibenzoate;
- silanes, siloxanes, silicone oils, organic sulfones corresponding to the formula RSO2R, organic ketones (R—(C═O)—R), organic nitriles (RCN), organic sulfoxides (R2—SO2), organic amides (R—(C═O)—NR′R or R—(S═O)—ONR′R).
Process for the preparation of barium sulfate having an average particle diameter d50 of from 0.1 to 10 μm and precipitated by mixing of barium- and of sulfate-containing solution, characterised in that the separated filter cake is dried and then homogeneously mixed with organic additive, the organic additive being selected from one or more of the substances or groups of substances:
- carboxylic acids, soaps, metallic soaps, alcohols;
- polyhydric alcohols, such as pentaerythritol, neopentyl glycol and trimethylolpropane;
- polyalcohols, such as polypropylene glycol and polyethylene glycol;
- organic esters, such as neopentyl glycol dibenzoate;
- silanes, siloxanes, silicone oils, organic sulfones corresponding to the formula RSO2R, organic ketones (R—(C═O)—R), organic nitrites (RCN), organic sulfoxides (R2—SO2), organic amides (R—(C═O)—NR′R or R—(S═O)—ONR′R).
Dependencies are inferred from the claim text.