Charge control agent, manufacturing process thereof, charge control resin particles and toner for developing electrostatic images
AssigneeOrient Chemical Industries, Ltd.
InventorsAkihide Isoda, Tetsuji Kihara, Tohru Tsuruhara
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Abstract
Charge control agent whose active ingredient is a zinc compound of an alkylsalicylic acid derivative, the compound being a zincified alkylsalicylic acid derivative which is an alkylphenol derivative having a carboxyl group introduced thereto; Toner for developing electrostatic images, comprising said charge control agent, a coloring agent and a binder resin for toner; Charge control resin particles comprising solidified milled particles of a thermally kneaded mixture of at least said charge control agent and a resin.
Claims10
Process for manufacturing charge control agent whose active ingredient is a zinc compound of 3,5-di-tert-butylsalicylic acid comprising:
- dissolving 3,5-di-tert-butylsalicylic acid which is a 2,4-di-tert-butylphenol having a carboxyl group introduced thereto in a sufficient amount of an alkaline aqueous solution to prepare an aqueous solution of 3,5-di-tert-butylsalicylic acid;
- adding said aqueous solution of 3,5-di-tert-butylsalicylic acid drop by drop to an aqueous solution containing a zinc provider while heating this zinc provider containing aqueous solution;
- carrying out a reaction between said 3,5-di-tert-butylsalicylic acid and said zinc provider with heating and pH adjustment;
- said zinc compound being a crystalline zinc 3,5-di-tert-butylsalicylate represented by General Formula (1) below, and having major peaks of X-ray diffraction using the CuKα-characteristic X-ray at Bragg angles 2θ of at least 7.7±0.2° and 15.7±0.2°:
- in which t-Bu represents a tert-butyl group.
Process for manufacturing charge control agent whose active ingredient is a crystalline zinc 3,5-di-tert-butylsalicylate represented by General Formula (1) below, and having major peaks of X-ray diffraction using the CuK α-characteristic X-ray at Bragg angles 2θ of at least 5.2±0.2°, 6.7±0.2°, 7.7±0.2° and 15.7±0.2° comprising:
- (f) a step for adding an alkaline aqueous solution to a 3,5-di-tert-butylsalicylic acid, which is dissolved with heating, said 3,5-di-tert-butylsalicylic acid being a 2,4-di-tert-butylphenol having a carboxyl group introduced thereto by the Kolbe-Schmitt reaction;
- (g) a step for preparing an aqueous solution of a zinc provider in water;
- (h) a reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step (f) is added drop by drop to the aqueous solution of a zinc provider obtained in step (g) to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, while heating the aqueous solution of the zinc provider, and the reaction is carried out with heating and pH adjustment:
- in which t-Bu represents a tert-butyl group.
A process for manufacturing charge control agent whose active ingredient is a crystalline zinc 3,5-di-tert-butylsalicylate represented by General Formula (1) below, and having major peaks of X-ray diffraction using the CuK α-characteristic X-ray at Bragg angles 2θ of at least 5.2±0.2°, 6.7±0.2°, 7.7±0.2° and 15.7±0.2° comprising:
- (k) step for dissolving a 3,5-di-tert-butylsalicylic acid, which is a 2,4-di-tert-butylphenol having a carboxyl group introduced thereto by the Kolbe-Schmitt reaction, in a sodium hydroxide aqueous solution, and heating said solution to about 70°°C.;
- (1) step for dissolving a zinc sulfate heptahydrate in water;
- and
- (m) step wherein the resultant aqueous solution of 3,5-di-tert-butylsalicylic acid in step (k) is added drop by drop to the aqueous solution of a zinc sulfate obtained in step (1), the reaction being carried out at 70 to 80° C. for 2 hours, and the pH of the reaction mixture being adjusted to 7.0±0.5 to complete the reaction:
- in which t-Bu represents a tert-butyl group.
Dependencies are inferred from the claim text.