Process for producing chain structured corpuscular calcium carbonate
First Claim
1. In a process for producing chain structured corpuscular calcium carbonate, an improvement which comprises a first carbonation of calcium hydroxide in a form of an aqueous suspension containing 0.1 to 20 wt. parts of a chelating agent for CaOH per 100 wt. parts of calcium hydroxide to form a viscous colloidal suspension and a second carbonation of the resulting viscous colloidal suspension containing 0.0001 to 0.5 mole of a water soluble metal salt which forms a water insoluble precipitate in an aqueous suspension of calcium hydroxide per 1 mole of calcium hydroxide as the starting material, carrying out the carbonation to be pH of 7 to 8 at the temperature of the aqueous suspension of 0°
- to 30°
C. during the first and second carbonations, whereby chain-structured corpuscular calcium carbonate having an aspect ratio of length to diameter of from 5 to 50 and a primary particle average diameter of 0.01 to 0.1μ
is produced.
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Abstract
Chain structured corpuscular calcium carbonate is produced by a carbonation of calcium hydroxide suspended in water in the presence of a chelating agent and a water soluble metal salt.
40 Citations
8 Claims
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1. In a process for producing chain structured corpuscular calcium carbonate, an improvement which comprises a first carbonation of calcium hydroxide in a form of an aqueous suspension containing 0.1 to 20 wt. parts of a chelating agent for CaOH per 100 wt. parts of calcium hydroxide to form a viscous colloidal suspension and a second carbonation of the resulting viscous colloidal suspension containing 0.0001 to 0.5 mole of a water soluble metal salt which forms a water insoluble precipitate in an aqueous suspension of calcium hydroxide per 1 mole of calcium hydroxide as the starting material, carrying out the carbonation to be pH of 7 to 8 at the temperature of the aqueous suspension of 0°
- to 30°
C. during the first and second carbonations, whereby chain-structured corpuscular calcium carbonate having an aspect ratio of length to diameter of from 5 to 50 and a primary particle average diameter of 0.01 to 0.1μ
is produced. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- to 30°
Specification