Patent Application
20070275316
The invention is explained concretely by referring examples below, however the invention is not restricted to these.
(Preparation of Latex 6HML)
Into a 5,000 ml separable flask, to which a stirring device, a thermal sensor, a cooling pipe and a nitrogen gas introducing device are attached, a surfactant solution (aqueous medium) composed of 3,010 g of deionized water and 7.08 g of an anionic surfactant, sodium lauryl sulfate, dissolved in the deionized water was charged and heated by 80° C. while stirring at a stirring rate of 230 rpm.
To the surfactant solution, an initiator solution composed of 400 g of deionized water and 9.2 g of a polymerization initiator (potassium persulfate: KPS) dissolved therein was added and then the temperature was adjusted to 75° C. After that, a mixture of monomers composed of 69.4 g of styrene, 28.3 g of n-butyl acrylate, and 2.30 g of methacrylate was dropped spending 1 hour. The system was heated and stirred at 75° C. for 2 hours to perform the polymerization (the first step polymerization) to form latex (dispersion of resin particles composed of high molecular weight resin). The latex was referred to as Latex 6H.
A monomer solution was prepared by adding 98.0 g of compound represented by the following Formula, to a monomer mixture liquid composed of 97.1 g of styrene, 39.7 g of n-butyl acrylate, 3.22 g of methacrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester at 90° C. in a flask to which a stirring device was attached.
On the other hand, a surfactant solution composed of 2,700 ml of deionized water and, dissolved therein, 1.6 g of an anionic surfactant, sodium lauryl sulfate, was heated up to 98° C. and 28 g in terms of solid ingredient of Latex 6H which is a dispersion of the core particles was added to the surfactant solution. Then the above prepared monomer solution of Exemplified Compound 19 was mixed and dispersed for 8 hours in the above resulted liquid by a mechanical dispersing apparatus having a circulation pass CLEARMIX manufactured by M Technique Co., Ltd., to prepare a dispersion (emulsion) containing emulsified particles (oil droplets).
After that, an initiator liquid composed of 240 ml of deionized water and 5.1 g of the polymerization initiator (KPS) dissolved therein, and 750 ml of deionized water was added to the dispersion liquid (emulsion), the system was heated and stirred for 12 hours at 98° C. to perform polymerization (second step polymerization). Thus latex was obtained which was referred to as Latex 6HM, which is a dispersion liquid of composite resin particles having a structure that the surface of resin particles composed of the high molecular weight resin is covered with a resin having medium molecular weight.
To thus obtained Latex 6HM, an initiator solution composed of 200 ml of deionized water and 7.4 g of the polymerization initiator (KPS) dissolved therein was added and then a monomer mixture liquid composed of 277 g of styrene, 113 g of n-butyl acrylate, 9.21 g of methacrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was dropped to the latex spending for 1 hour at a temperature condition of 80° C. After completion of the dropping, the resulted liquid was heated and stirred for 1 hour for polymerization (third step polymerization), and then cooled by 28° C. to obtain latex. Thus obtained latex was referred to as Latex 6HML.
Black colored particles, Toner Origin A, was prepared as follows.
(1) Preparation of Colorant Dispersion 1
In 1,600 ml of deionized water, 90 g of the anionic surfactant was dissolved by stirring. To the solution, 400.0 g of carbon black Regal 330R manufactured by Cabot Co., Ltd., was gradually added while stirring, and then dispersed by the stirring apparatus CLEAMIX manufactured by M Technique Co., Ltd. so as to obtain the colorant particles having particle diameter of less than 200 nm, and dispersion of a colorant was obtained. The dispersion was referred to as Colorant Dispersion 1.
(2) (Coagulation•Fusion) Preparation of Coagulated Particles
Into a reaction vessel (four-mouth flask) to which a thermal sensor, a cooling tube, a nitrogen gas introducing device and a stirring device were attached, 200 g in terms of solid ingredient of Latex 6HML, 3,000 g of deionized water and 71 g of Colorant Dispersion 1 were charged. The inner temperature of the vessel was adjusted to 30° C. and then the pH value of the liquid was adjusted to 8-11.0 by adding a 5 mol/L aqueous solution of sodium hydroxide. After that, a solution composed of 20 ml of deionized water and, dissolved therein, 20 g of magnesium chloride hexahydrate was dropped to the above liquid spending for 10 minutes at 30° C. The liquid was stood for 3 minutes and then heated up to 75° C. spending 60 minutes. Under such the conditions, the diameter of the associated particle was measured by Coulter Counter MS-II, and an aqueous solution composed of 60 ml of deionized water and, dissolved therein, 29 g of sodium succinate was added at a time when the number average diameter of the particles was attained at 6-7 μm to stop the growing the particles. Moreover, the fusion of the particles was continued as a ripening treatment by heating and stirring for 6 hours at 90° C. After that temperature was cooled down to 30° C., pH was adjusted to 2.0 with hydrochloric acid, then stirring was terminated. Thus formed particles of salted out, coagulated and fused were filtrated and washed repeatedly with deionized water at 45° C. Black Colored particles Toner Origin A was obtained by drying warm air at 40° C.
Toner origins B-E employed for Toner 102-110 and Toner 202-210 are shown below.
(Preparation of Latex 8HML)
Into a 5,000 ml separable flask, to which a stirring device, a thermal sensor, a cooling pipe and a nitrogen gas introducing device are attached, a surfactant solution (aqueous medium) composed of 3,010 g of deionized water and 7.08 g of an anionic surfactant, sodium lauryl sulfate, dissolved in the deionized water was charged and heated by 80° C. while stirring at a stirring rate of 230 rpm.
To the surfactant solution, an initiator solution composed of 200 g of deionized water and 9.2 g of a polymerization initiator (potassium persulfate: KPS) dissolved therein was added and then the temperature was adjusted to 75° C. After that, a mixture of monomers composed of 70.3 g of styrene, 28.7 g of n-butyl acrylate, and 1.00 g of methacrylic acid was dropped spending 1 hour. The system was heated and stirred at 75° C. for 2 hours to perform the polymerization (the first step polymerization) to form latex (dispersion of resin particles composed of high molecular weight resin). The latex was referred to as Latex 8H.
A monomer solution was prepared by adding 98.0 g of crystallization substance, Compound A, to a monomer mixture liquid composed of 98.3 g of styrene, 40.2 g of n-butyl acrylate, 1.51 g of methacrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester at 90° C. in a flask to which a stirring device was attached.
On the other hand, a surfactant solution composed of 2,700 ml of deionized water and, dissolved therein, 1.6 g of an anionic surfactant, sodium lauryl sulfate, was heated up to 98° C. and 28 g in terms of solid ingredient of Latex 5H which is a dispersion of the core particles was added to the surfactant solution, then they were mixed and dispersed for 8 hours in the above resulted liquid by a mechanical dispersing apparatus having a circulation pass CLEARMIX manufactured by M Technique Co., Ltd., to prepare a dispersion (emulsion) containing emulsified particles (oil droplets).
After that, an initiator liquid composed of 240 ml of deionized water and 5.1 g of the polymerization initiator (KPS) dissolved therein, and 750 ml of deionized water was added to the dispersion liquid (emulsion), the system was heated and stirred for 12 hours at 98° C. to perform polymerization (second step polymerization). Thus latex was obtained which was referred to as Latex 8HM, which is a dispersion liquid of composite resin particles having a structure that the surface of resin particles composed of the high molecular weight resin is covered with a resin having medium molecular weight.
To thus obtained Latex 8HM, an initiator solution composed of 200 ml of deionized water and 7.4 g of the polymerization initiator (KPS) dissolved therein was added and then a monomer mixture liquid composed of 283 g of styrene, 115 g of n-butyl acrylate, 4.30 g of methacrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was dropped to the latex spending for 1 hour at a temperature condition of 80° C. After completion of the dropping, the resulted liquid was heated and stirred for 2 hour for polymerization (third step polymerization), and then cooled by 28° C. to obtain latex. Thus obtained latex was referred to as Latex 8HML.
Toner Origin B was prepared in the same preparation way as Toner Origin A except that Latex 6HML was replaced by Latex 8HML.
(Preparation of Latex 4HML)
Into a 5,000 ml separable flask, to which a stirring device, a thermal sensor, a cooling pipe and a nitrogen gas introducing device are attached, a surfactant solution (aqueous medium) composed of 3,010 g of deionized water and 7.08 g of an anionic surfactant, sodium lauryl sulfate, dissolved in the deionized water was charged and heated by 80° C. while stirring at a stirring rate of 230 rpm.
To the surfactant solution, an initiator solution composed of 200 g of deionized water and 9.2 g of a polymerization initiator (potassium persulfate: KPS) dissolved therein was added and then the temperature was adjusted to 75° C. After that, a mixture of monomers composed of 74.5 g of styrene, 21.6 g of n-butyl acrylate, and 1.93 g of acrylic acid was dropped spending 1 hour. The system was heated and stirred at 75° C. for 2 hours to perform the polymerization (the first step polymerization) to form latex (dispersion of resin particles composed of high molecular weight resin). The latex was referred to as Latex 4H.
A monomer solution was prepared by adding 98.0 g of crystallization substance, Compound A, to a monomer mixture liquid composed of 104 g of styrene, 30.2 g of n-butyl acrylate, 2.7 g of acrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester at 90° C. in a flask to which a stirring device was attached.
On the other hand, a surfactant solution composed of 2,700 ml of deionized water and, dissolved therein, 1.6 g of an anionic surfactant, sodium lauryl sulfate, was heated up to 98° C. and 28 g in terms of solid ingredient of Latex 4H which is a dispersion of the core particles was added to the surfactant solution, then they were mixed and dispersed for 8 hours in the above resulted liquid by a mechanical dispersing apparatus having a circulation pass CLEARMIX manufactured by M Technique Co., Ltd., to prepare a dispersion (emulsion) containing emulsified particles (oil droplets).
After that, an initiator liquid composed of 240 ml of deionized water and 5.1 g of the polymerization initiator (KPS) dissolved therein, and 750 ml of deionized water was added to the dispersion liquid (emulsion), the system was heated and stirred for 12 hours at 98° C. to perform polymerization (second step polymerization). Thus latex was obtained which was referred to as Latex 4HM, which is a dispersion liquid of composite resin particles having a structure that the surface of resin particles composed of the high molecular weight resin is covered with a resin having medium molecular weight. The latex was referred to as Latex 4HM.
To thus obtained Latex 8HM, an initiator solution composed of 200 ml of deionized water and 7.4 g of the polymerization initiator (KPS) dissolved therein was added and then a monomer mixture liquid composed of 306 g of styrene, 88.5 g of n-butyl acrylate, 17.4 g of acrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was dropped to the latex spending for 2 hour at a temperature condition of 80° C. After completion of the dropping, the resulted liquid was heated and stirred for 2 hour for polymerization (third step polymerization), and then cooled by 28° C. to obtain latex. Thus obtained latex was referred to as Latex 4HML.
Toner Origin C was prepared in the same preparation way as Toner Origin A except that Latex 6HML was replaced by Latex 4HML.
(Preparation of Latex 12HML)
Into a 5,000 ml separable flask, to which a stirring device, a thermal sensor, a cooling pipe and a nitrogen gas introducing device are attached, a surfactant solution (aqueous medium) composed of 3,010 g of deionized water and 7.08 g of an anionic surfactant, sodium lauryl sulfate, dissolved in the deionized water was charged and heated by 80° C. while stirring at a stirring rate of 230 rpm.
To the surfactant solution, an initiator solution composed of 200 g of deionized water and 9.2 g of a polymerization initiator (potassium persulfate: KPS) dissolved therein was added and then the temperature was adjusted to 75° C. After that, a mixture of monomers composed of 70.7 g of styrene, 28.9 g of n-butyl acrylate, and 0.386 g of acrylic acid was dropped spending 1 hour. The system was heated and stirred at 75° C. for 2 hours to perform the polymerization (the first step polymerization) to form latex (dispersion of resin particles composed of high molecular weight resin). The latex was referred to as Latex 12H.
A monomer solution was prepared by adding 98.0 g of crystallization substance, Compound A, to a monomer mixture liquid composed of 99.0 g of styrene, 40.4 g of n-butyl acrylate, 0.54 g of acrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester at 90° C. in a flask to which a stirring device was attached.
On the other hand, a surfactant solution composed of 2,700 ml of deionized water and, dissolved therein, 1.6 g of an anionic surfactant, sodium lauryl sulfate, was heated up to 98° C. and 28 g in terms of solid ingredient of Latex 4H which is a dispersion of the core particles was added to the surfactant solution, then they were mixed and dispersed for 8 hours in the above resulted liquid by a mechanical dispersing apparatus having a circulation pass CLEARMIX manufactured by M Technique Co., Ltd., to prepare a dispersion (emulsion) containing emulsified particles (oil droplets).
After that, an initiator liquid composed of 240 ml of deionized water and 5.1 g of the polymerization initiator (KPS) dissolved therein, and 750 ml of deionized water was added to the dispersion liquid (emulsion), the system was heated and stirred for 12 hours at 98° C. to perform polymerization (second step polymerization). Thus latex was obtained which was referred to as Latex 4HM, which is a dispersion liquid of composite resin particles having a structure that the surface of resin particles composed of the high molecular weight resin is covered with a resin having medium molecular weight. The latex was referred to as Latex 12HM.
To thus obtained Latex 12HM, an initiator solution composed of 200 ml of deionized water and 7.4 g of the polymerization initiator (KPS) dissolved therein was added and then a monomer mixture liquid composed of 281 g of styrene, 114.8 g of n-butyl acrylate, 1.54 g of acrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was dropped to the latex spending for 2 hour at a temperature condition of 80° C. After completion of the dropping, the resulted liquid was heated and stirred for 2 hour for polymerization (third step polymerization), and then cooled by 28° C. to obtain latex. Thus obtained latex was referred to as Latex 12HML.
Toner Origin D was prepared in the same preparation way as Toner Origin A except that Latex 12HML was employed in place of Latex 6HML.
Into a 5,000 ml separable flask, to which a stirring device, a thermal sensor, a cooling pipe and a nitrogen gas introducing device are attached, a surfactant solution (aqueous medium) composed of 3,010 g of deionized water and 7.08 g of an anionic surfactant, sodium lauryl sulfate, dissolved in the deionized water was charged and heated by 80° C. while stirring at a stirring rate of 230 rpm.
To the surfactant solution, an initiator solution composed of 200 g of deionized water and 9.2 g of a polymerization initiator (potassium persulfate: KPS) dissolved therein was added and then the temperature was adjusted to 75° C. After that, a mixture of monomers composed of 67.8 g of styrene, 27.7 g of n-butyl acrylate, and 4.50 g of methacrylic acid was dropped spending 1 hour. The system was heated and stirred at 75° C. for 2 hours to perform the polymerization (the first step polymerization) to form latex (dispersion of resin particles composed of high molecular weight resin). The latex was referred to as Latex 9H.
A monomer solution was prepared by adding 98.0 g of crystallization substance, Compound A, to a monomer mixture liquid composed of 94.1 g of styrene, 38.4 g of n-butyl acrylate, 7.53 g of methacrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester at 90° C. in a flask to which a stirring device was attached.
On the other hand, a surfactant solution composed of 2,700 ml of deionized water and, dissolved therein, 1.6 g of an anionic surfactant, sodium lauryl sulfate, was heated up to 98° C. and 28 g in terms of solid ingredient of Latex 9H which is a dispersion of the core particles was added to the surfactant solution, then they were mixed and dispersed for 8 hours in the above resulted liquid by a mechanical dispersing apparatus having a circulation pass CLEARMIX manufactured by M Technique Co., Ltd., to prepare a dispersion (emulsion) containing emulsified particles (oil droplets).
After that, an initiator liquid composed of 240 ml of deionized water and 5.1 g of the polymerization initiator (KPS) dissolved therein, and 750 ml of deionized water was added to the dispersion liquid (emulsion), the system was heated and stirred for 12 hours at 98° C. to perform polymerization (second step polymerization). Thus latex was obtained which was referred to as Latex 4HM, which is a dispersion liquid of composite resin particles having a structure that the surface of resin particles composed of the high molecular weight resin is covered with a resin having medium molecular weight. The latex was referred to as Latex 9HM.
To thus obtained Latex 9HM, an initiator solution composed of 200 ml of deionized water and 7.4 g of the polymerization initiator (KPS) dissolved therein was added and then a monomer mixture liquid composed of 269 g of styrene, 110 g of n-butyl acrylate, 21.5 g of acrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was dropped to the latex spending for 2 hour at a temperature condition of 80° C. After completion of the dropping, the resulted liquid was heated and stirred for 2 hour for polymerization (third step polymerization), and then cooled by 28° C. to obtain latex. Thus obtained latex was referred to as Latex 9HML.
Toner Origin E was prepared in the same preparation way as Toner Origin A except that Latex 9HML was employed in place of Latex 6HML.
In the wet system sizing process of strontium titanate (being a titanic acid compound), primary sizing was carried out by adding dimethyl polysiloxane (being silicone oil) in an amount of 1.0% by weight based on the total weight of strontium titanate.
Thereafter, drying was conducted and secondary sizing was carried out employing a flash system pulverizer, whereby a silicon oil-treated titanic acid compound was prepared.
Added to Toner Origin A, prepared as above, were 1.0% by weight of hydrophobic silica (CAB-O-SIL TG-811F, produced by Cabot Corporation), and 1.0% by weight of NX90 (produced by Nippon Aerosil Co., Ltd.), and the resulting mixture was mixed via a Henschel mixer (produced by Mitsui Mining and Smelting Co., Ltd.). Thereafter, coarse particles were removed employing a 45 μm opening sieve, whereby Toner 101 was prepared.
Toners 102-110 were prepared in the same manner as Toner 101, except that the toner origin (type and acid value), the titanic acid compound (type, number average radius of primary particles, and added amount to the toner origin), and silicone oil (type, and added amount to the titanic acid compound) were changed as listed in Table 1-1. Toner 110 was not subjected to the silicone oil treatment.
Under vigorous stirring, added to an acid solution adjusted to a pH of 4, employing 1 mol/L hydrochloric acid, was strontium titanate (being a titanic acid compound) at a temperature higher then the boiling point of the acid solution. Subsequently, the resulting strontium titanate solution was diluted with toluene, followed by dripping of 3% by weight methyltrialkoxysilane (being a coupling agent) at a constant rate. After dripping, stirring was continued awhile while maintaining the temperature, whereby the coupling treatment was completed. After sufficient drying, sizing was carried out employing a flash system pulverizer, whereby a coupling agent treated-titanic acid compound was prepared.
Added to Toner Origin A, prepared as above, were 2.0% by weight of the titanic acid compound treated with the coupling agent, 1.0% by weight of hydrophobic silica (CAB-O-SIL TG-811F, produced by Cabot Corporation), and 1.0% by weight of NX90 (produced by Nippon Aerosil Co., Ltd.), and the resulting mixture was mixed employing a Henschel mixer (produced by Mitsui Mining Co., Ltd.). Thereafter, coarse particles were removed via a 45 μm opening sieve, whereby Toner 201 was prepared.
Toners 202-210 were prepared in the same manner as Toner 201, except that the toner origin (type and acid value), the titanic acid compound (type, number average radius of primary particles, and added amount to the toner origin), and the coupling agent (type, and added amount to the titanic acid compound) were changed as listed in Table 2-1. Toner 210 was not subjected to the coupling agent treatment.
Acid value of each of the prepared toners was determined based on to JIS-K0070-1992.
Further, by employing a full-color printer, MAGICOLOR 2300DL (produced by Konica Minolta Technologies, Inc.), equipped with a non-magnetic single-component apparatus, each of the prepared toners was allowed to stand at high temperature and high humidity (30° C. and 85% relative humidity) for 24 hours, and a print pattern at a 6% B/W ratio was printed onto 5,000 sheets and 10,000 sheets. Further, after the toner was allowed to stand at low temperature and low humidity (10° C. and 15% relative humidity) for 24 hours, a print pattern at a 6% B/W ratio was printed onto 10,000 sheets. Thereafter, image density, fog, and (at low temperature and low humidity, halftone slight touching and spot defects) were evaluated.
After completion of printing, the absolute density of a solid image portion on the sheet was determined employing MACBETH REFLECTION DENSITOMETER “RD-918”.
After completion of the endurance printing run, a relative density with respect to the sheet was determined.
Absolute densities at 20 positions of a blank sheet were determined employing MACBETH REFLECTION DENSITOMETER “RD-918” and the averaged value was designated as density of the blank sheet. Subsequently, absolute densities at 20 positions of the white portion of the evaluation image were determined and averaged. The value which was obtained by subtracting the above averaged value form the density of the blank sheet was designated as fog density, which was employed for evaluation. Fog density of at most 0.01 was judged to be commercially viable.
At completion of the endurance printing run, a solid image was outputted and image defects, due to abrasion of the photoreceptor, were visually evaluated.
Tables 1-2 and 2-2 show the evaluation results.
As can be seen from the tables, toners of the present invention result in excellent image density, and minimize fog, slight touching and spot defects, and enable stable formation of high quality images over a long period.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2006-147795 | May 2006 | JP | national |
| JP2006-149484 | May 2006 | JP | national |
