Methanol → 5,12-Dihydroquinolino[2,3-b]acridine-7,14-dione;2,9-dimethyl-5,12-dihydroquinolino[2,3-b]acridine-7,14-dione

Participants

Reaction Conditions

Reaction Steps

Ten parts of a styrene/acrylic acid/glycidyl methacrylate (7/2/1; molar ratio) terpolymer (molecular weight: 5,000) as a self-crosslinkable compound were dissolved in 80 parts of dimethyl sulfoxide, and 10 parts of a quinacridone pigment (C.I. Pigment Red 122) were suspended in the resultant solution in a flask at 25° C. under an air atmosphere. A 30% methanol solution of potassium hydroxide was then added dropwise little by little to dissolve the quinacridone pigment. After the pigment solution was stirred for 3 hours, it was quickly poured into ion-exchanged water (400 parts of ion-exchanged water per 10 parts of the pigment; 0° C.) stirred by an impeller type agitating blade (800 rpm), purged with nitrogen and cooled and temperature-maintained by means of 2 system dispensers (manufactured by Musashi Engineering K.K.; needle internal diameter: 0.57 mm; delivery pressure: 4.0 kgf/cm2) to obtain an aqueous dispersion of quinacridone-pigment-containing particles having an average particle diameter of 30.2 nm. This aqueous dispersion was transferred to a reaction vessel equipped with a mantle heater, cooling tower, stirrer and thermometer, and this system was purged with nitrogen with stirring at 300 rpm and heated to an internal temperature of 60° C. While retaining the internal temperature of 60° C., the stirring was continued for additional 5 hours, and the reaction mixture was then cooled back to room temperature. Thereafter, 10% hydrochloric acid was added dropwise to adjust the pH of the reaction mixture to 4.0. The resultant aggregates were filtered under reduced pressure through a membrane filter (holding particle diameter: 0.45 μm) and washed 3 times with 500 ml of ion-exchanged water to obtain a paste of an aqueous dispersion of the quinacridone-pigment-containing particles desalted and desolvated.

Provenance & Evidence