Change control resin particles and toner for developing electrostatic images

1. 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:

[a] step for dissolving a 3,5-di-tert-butylsalicylic acid, which is obtained by butylation of salicylic acid, in an alkaline aqueous solution;

[b] step for dissolving a zinc provider in water;

[c] reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step [a] is added to the aqueous solution of a zinc provider obtained in step [b] while heating the aqueous solution of a zinc provider, and the mixture is stirred with heating until the reaction is completed:

in which t-Bu represents a tert-butyl group.

2. Process of claim 1 , further comprising a step of:

[d] post-treatment step for filtering the reaction mixture obtained in step [c] and washing, drying and then milling the cake filtered off.

3. Process of claim 1 , wherein said zinc provider is a zinc sulfate, a zinc chloride or a zinc acetate.

4. Process of claim 2 , wherein said zinc provider is a zinc sulfate, a zinc chloride or a zinc acetate.

5. Process of claim 1 , wherein said step [c] is a reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step [a] is added to the aqueous solution of a zinc provider obtained in step [b] while heating the aqueous solution of a zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the mixture is stirred with heating until the reaction is completed.

6. Process of claim 2 , wherein said step [c] is a reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step [a] is added to the aqueous solution of a zinc provider obtained in step [b] while heating the aqueous solution of a zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the mixture is stirred with heating until the reaction is completed.

7. Process of claim 3 , wherein said step [c] is a reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step [a] is added to the aqueous solution of a zinc provider obtained in step [b] while heating the aqueous solution of a zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the mixture is stirred with heating until the reaction is completed.

8. Process of claim 4 , wherein said step [c] is a reaction step wherein the aqueous solution of 3,5-di-tert-butylsalicylic acid obtained in step [a] is added to the aqueous solution of a zinc provider obtained in step [b] while heating the aqueous solution of a zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the mixture is stirred with heating until the reaction is completed.

9. 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 obtained by butylation of salicylic acid;

[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] 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.

10. Process of claim 9 , further comprising a step of

[i] a step for filtering the reaction mixture obtained in step [h] after completion of the reaction, and washing with water and drying the cake filtered off.

11. Process of claim 9 , wherein said zinc provider is a zinc sulfate, a zinc chloride or a zinc acetate.

12. Process of claim 10 , wherein said zinc provider is a zinc sulfate, a zinc chloride or a zinc acetate.

13. Process of claim 9 , wherein said step [h] is 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] while heating the aqueous solution of the zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the reaction is carried out with heating and pH adjustment.

14. Process of claim 10 , wherein said step [h] is 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] while heating the aqueous solution of the zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the reaction is carried out with heating and pH adjustment.

15. Process of claim 11 , wherein said step [h] is 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] while heating the aqueous solution of the zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the reaction is carried out with heating and pH adjustment.

16. Process of claim 12 , wherein said step [h] is 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] while heating the aqueous solution of the zinc provider to cause a reaction between the zinc provider and the 3,5-di-tert-butylsalicylic acid, and the reaction is carried out with heating and pH adjustment.

17. Process for manufacturing charge control agent whose active ingredient is a crystalline zinc 3,5-di-tert-butylsalicylate 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 obtained by butylation of salicylic acid, in a sodium hydroxide aqueous solution, and heating said solution to about 70° C.;

[l] 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 [l], the reaction is carried out at 70 to 80° C. for 2 hours, and the pH of the reaction mixture is adjusted to 7.0±0.5 to complete the reaction.

18. Process of claim 17 , further comprising a step of:

[n] step for filtering the reaction solution obtained in step [m] while the reaction solution remains hot, and the cake filtered off is washed with water and dried.

19. Process of claim 17 , wherein said step [m] is a 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 [l] to cause a reaction between the zinc sulfate and the 3,5-di-tert-butylsalicylic acid, the reaction is carried out at 70 to 80° C. for 2 hours, and the pH of the reaction mixture is adjusted to 7.0±0.5 to complete the reaction.

20. Process of claim 18 , wherein said step [m] is a 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 [l] to cause a reaction between the zinc sulfate and the 3,5-di-tert-butylsalicylic acid, the reaction is carried out at 70 to 80° C. for 2 hours, and the pH of the reaction mixture is adjusted to 7.0±0.5 to complete the reaction.

21. Process of claim 17 , wherein said crystalline zinc 3,5-di-tert-butylsalicylate is represented by General Formula (1) below:

in which t-Bu represents a tert-butyl group.

22. Process of claim 18 , wherein said crystalline zinc 3,5-di-tert-butylsalicylate is represented by General Formula (1) below:

in which t-Bu represents a tert-butyl group.

23. Process of claim 19 , wherein said crystalline zinc 3,5-di-tert-butylsalicylate is represented by General Formula (1) below:

in which t-Bu represents a tert-butyl group.

24. Process of claim 20 , wherein said crystalline zinc 3,5-di-tert-butylsalicylate is represented by General Formula (1) below:

in which t-Bu represents a tert-butyl group.