Patent Application
20080090163
Five examples are provided below. Example I describes a process for producing a substantially surfactantless emulsion containing propoxylated bisphenol A fumarate amorphous resin and carnauba wax stabilized with sodium bicarbonate. Example II and III describe a processes for producing an emulsion containing propoxylated bisphenol A fumarate amorphous resin and stearyl stearamide wax and carnauba wax, respectively, stabilized with ammonium hydroxide and low levels of anionic surfactant. Example IV describes a process for producing a substantially surfactantless emulsion containing CPES-A11 crystalline polyester resin (Kao Corp., Japan) stabilized with sodium bicarbonate. Example V describes a process for producing an ultra low melt toner with excellent fusing, A zone charging and cohesion performance wherein the emulsions of Examples I and IV are utilized as ingredients.
113.2 grams of amorphous propoxylated bisphenol A fumarate resin and 11.8 grams of RC-160 carnauba wax (Toa Kasei Co., Ltd., Japan) is measured into a 2 liter beaker containing about 917 grams of ethyl acetate. The resin has an acid number of about 16.7 as measured by titration with KOH, weight average and number average molecular weight of about 12,000 and 4,200 respectively as measured by GPC and onset glass transition temperature of about 56° C. as measured by DSC. The wax has a melting point of about 84° C. as measured by DSC. The mixture is stirred at about 250 revolutions per minute and heated to about 67° C. to dissolve the resin and wax in the ethyl acetate. 3.05 grams of sodium bicarbonate are measured into a 4 liter Pyrex glass flask reactor containing about 708 grams of deionized water and heated to about 65° C. Homogenization of the heated water solution in the 4 liter glass flask reactor is commenced with an IKA Ultra Turrax T50 homogenizer at about 4,000 revolutions per minute. The heated resin and wax solution is then slowly poured into the water solution as the mixture continues to be homogenized, the homogenizer speed is increased to about 10,000 revolutions per minute and homogenization is carried out at these conditions for about 30 minutes. At completion of homogenization, the glass flask reactor and its contents are placed in a heating mantle and connected to a distillation device. The mixture is stirred at about 400 revolutions per minute and the temperature of the mixture is increased to about 80° C. at about 1° C. per minute to distill off the ethyl acetate from the mixture. Stirring of the mixture is continued at 80° C. for about 120 minutes followed by cooling at about 2° C. per minute to room temperature. The product is screened through a 20 micron sieve and the pH is adjusted to 7.0 with the addition of 1.0 Normal sodium hydroxide. The resulting resin and wax emulsion is comprised of about 18.8 percent by weight solids in water as measured gravimetrically wherein the solid contains 9.4 percent by weight of wax and 90.6 percent by weight of amorphous polyester resin, has a volume average diameter of about 176 nanometers as measured with a HONEYWELL MICROTRAC® UPA150 particle size analyzer, and has an onset Tg (resin portion) of about 57° C. and peak melting point (wax portion) of about 83° C. as measured by DSC. Since there is substantially no drop in the resin Tg portion of the emulsion, it can be concluded that there is substantially no plastification of the resin by the wax during emulsification.
56.6 grams of amorphous propoxylated bisphenol A fumarate resin, 56.6 g grams of branched amorphous propoxylated bisphenol A fumarate resin and 11.8 grams of KEMAMIDE S-180 stearyl stearamide wax (Crompton-Witco, USA) is measured into a 2 liter beaker containing about 917 grams of ethyl acetate. The unbranched amorphous resin has an acid number of about 16.7 as measured by titration with KOH, weight average and number average molecular weight of about 12,000 and 4,200 respectively as measured by GPC and onset glass transition temperature of about 56° C. as measured by DSC. The branched amorphous resin has an acid number of about 14.7, weight average and number average molecular weight of about 34,700 and 5,600 and onset glass transition temperature of about 57° C. The wax has a melting point of about 95° C. as measured by DSC. The mixture is stirred at about 250 revolutions per minute and heated to about 67° C. to dissolve the resin and wax in the ethyl acetate. 3.0 grams of concentrated ammonium hydroxide and 1.4 grams of Dowfax 2A1 anionic surfactant are measured into a 4 liter Pyrex glass flask reactor containing about 708 grams of deionized water and heated to about 65° C. Homogenization of the heated water solution in the 4 liter glass flask reactor is commenced with an IKA Ultra Turrax T50 homogenizer at about 4,000 revolutions per minute. The heated resin and wax solution is then slowly poured into the water solution as the mixture continues to be homogenized, the homogenizer speed is increased to about 10,000 revolutions per minute and homogenization is carried out at these conditions for about 30 minutes. At completion of homogenization, the glass flask reactor and its contents are placed in a heating mantle and connected to a distillation device. The mixture is stirred at about 400 revolutions per minute and the temperature of the mixture is increased to about 80° C. at about 1° C. per minute to distill off the ethyl acetate from the mixture. Stirring of the mixture is continued at 80° C. for about 120 minutes followed by cooling at about 2° C. per minute to room temperature. The product is screened through a 20 micron sieve and the pH is adjusted to 7.0 with the addition of 1.0 Normal sodium hydroxide. The resulting resin and wax emulsion is comprised of about 21.7 percent by weight solids in water as measured gravimetrically wherein the solid contains 9.4 percent by weight of wax and 90.6 percent by weight of amorphous polyester resin, has a volume average diameter of about 173 nanometers as measured with a HONEYWELL MICROTRAC® UPA150 particle size analyzer, and has an onset Tg (resin portion) of about 57° C. and peak melting point (wax portion) of about 94° C. as measured by DSC. Since there is substantially no drop in the resin Tg portion of the emulsion, it can be concluded that there is substantially no plastification of the resin by the wax during emulsification. From the DSC results of said emulsion, there is substantially no drop in the Tg and therefore there is substantially no plastification of the resin by the wax.
56.6 grams of amorphous propoxylated bisphenol A fumarate resin, 56.6 g grams of branched amorphous propoxylated bisphenol A fumarate resin and 11.8 grains of RC-160 carnauba wax is measured into a 2 liter beaker containing about 917 grams of ethyl acetate. The unbranched amorphous resin has an acid number of about 16.7 as measured by titration with KOH, weight average and number average molecular weight of about 12,000 and 4,200 respectively as measured by GPC and onset glass transition temperature of about 56° C. as measured by DSC. The branched amorphous resin has an acid number of about 14.7, weight average and number average molecular weight of about 34,700 and 5,600 and onset glass transition temperature of about 57° C. The wax has a melting point of about 95° C. as measured by DSC. The mixture is stirred at about 250 revolutions per minute and heated to about 67° C. to dissolve the resin and wax in the ethyl acetate. 3.0 grams of concentrated ammonium hydroxide and 1.4 grams of Dowfax 2A1 anionic surfactant are measured into a 4 liter Pyrex glass flask reactor containing about 708 grams of deionized water and heated to about 65° C. Homogenization of the heated water solution in the 4 liter glass flask reactor is commenced with an IKA Ultra Turrax T50 homogenizer at about 4,000 revolutions per minute. The heated resin and wax solution is then slowly poured into the water solution as the mixture continues to be homogenized, the homogenizer speed is increased to about 10,000 revolutions per minute and homogenization is carried out at these conditions for about 30 minutes. At completion of homogenization, the glass flask reactor and its contents are placed in a heating mantle and connected to a distillation device. The mixture is stirred at about 400 revolutions per minute and the temperature of the mixture is increased to about 80° C. at about 1° C. per minute to distill off the ethyl acetate from the mixture. Stirring of the mixture is continued at 80° C. for about 120 minutes followed by cooling at about 2° C. per minute to room temperature. The product is screened through a 20 micron sieve and the pH is adjusted to 7.0 with the addition of 1.0 Normal sodium hydroxide. The resulting resin and wax emulsion is comprised of about 18.4 percent by weight solids in water as measured gravimetrically wherein the solid contains 9.4 percent by weight of wax and 90.6 percent by weight of amorphous polyester resin, has a volume average diameter of about 186 nanometers as measured with a HONEYWELL MICROTRAC® UPA150 particle size analyzer, and has an onset Tg (resin portion) of about 56° C. and peak melting point (wax portion) of about 84° C. as measured by DSC. Since there is substantially no drop in the resin Tg portion of the emulsion, it can be concluded that there is substantially no plastification of the resin by the wax during emulsification. From the DSC results of said emulsion, there is substantially no drop in the Tg and therefore there is substantially no plastification of the resin by the wax.
125 grams of semi-crystalline CPES-A11 polyester resin (Kao Corporation, Japan) is measured into a 2 liter beaker containing about 917 grams of ethyl acetate. The polyester resin has an acid number of about 13.2 as measured by titration with KOH, weight average and number average molecular weight of about 13,600 and 6,700 respectively as measured by DSC and melting point of about 86° C. as measured by DSC. The mixture is stirred at about 250 revolutions per minute and heated to about 65° C. to dissolve the resin in the ethyl acetate. 2.4 grams of sodium bicarbonate are measured into a 4 liter Pyrex glass flask reactor containing about 708 grams of deionized water and heated to about 65° C. Homogenization of the heated water solution in the 4 liter glass flask reactor is commenced with an IKA Ultra Turrax T50 homogenizer at about 4,000 revolutions per minute. The heated resin and wax solution is the slowly poured into the water solution as the mixture continues to be homogenized, the homogenizer speed is increased to about 10,000 revolutions per minute and homogenization is carried out at these conditions for about 30 minutes. At completion of homogenization, the glass flask reactor and its contents are placed in a heating mantle and connected to a distillation device. The mixture is stirred at about 400 revolutions per minute and the temperature of the mixture is increased to about 80° C. at about 1° C. per minute to distill off the ethyl acetate from the mixture. Stirring of the mixture is continued at 80° C. for about 120 minutes followed by cooling at about 2° C. per minute to room temperature. The product is screened through a 20 micron sieve and the pH is adjusted to 7.0 with the addition of 1.0 Normal sodium hydroxide. The resulting resin emulsion is comprised of about 21.9 percent by weight crystalline polyester resin in water as measured gravimetrically and has a volume average diameter of about 282 nanometers as measured with a HONEYWELL MICROTRAC® UPA150 particle size analyzer.
A 2 liter kettle, equipped with a mechanical stirrer and heating mantle is charged with 374 grams of emulsion of Example I comprised of amorphous propoxylated bisphenol A fumarate resin and carnauba wax in water, 72.4 grams of emulsion of Example IV comprising of crystalline polyester resin in water, and 370 grains of deionized water. The mixture is homogenized at about 2,000 revolutions per minute, followed by the addition of 25.9 grams of pigment dispersion comprising about 17 percent by weight of Pigment Blue 15:3 cyan pigment, followed by a drop wise addition of 71 grains of a 0.3 Normal solution of nitric acid. During the acid addition, the homogenization is increased to about 4,500 revolutions per minute and maintained for about 5 minutes. The mixture is then stirred at about 175 revolutions per minute, and heated to about 36.5° C. followed by adding 4.5 gram solution of Taycapower BN2060 anionic surfactant (17.5 percent solids by weight; Tayca Corporation, Japan), and the pH of the mixture is increased from about 3.3 to about 6.82 with the addition of 4 percent sodium hydroxide solution. The stirring is reduced to about 70 revolutions per minute, and the mixture heated to about 67.5° C., followed by decreasing the pH to about 6.0 by the addition of a 0.3 Normal solution of nitric acid. The toner of this mixture comprises about 69.2 percent by weight of amorphous polyester resin, about 17.3 percent by weight of crystalline polyester resin, about 9 percent by weight of wax and about 4.5 percent by weight of pigment, and has a volume average particle size of about 7.65 microns as measured with a Coulter Counter and a circularity of about 0.96 as measured with a SYSMEX® FPIA-2100 flow-type histogram analyzer.
A cyan toner particle was prepared using the same formulation and process conditions as the Example V, except that separate polyester resin emulsion and wax emulsion are used, rather than the combined resin and wax emulsion of Example I. The wax emulsion is a carnauba wax emulsion stabilized with Taycapower BN2060 anionic surfactant. The respective toners of Example III and Comparative Example I are tested for their development properties, including charging and cohesion of the toner particles. The results are presented in Table 1, below.
Comparing the results in Table 1, it is apparent that the toner of Example V, which includes less surfactant due to the surfactantless wax and resin emulsion, exhibits improved results as compared to Comparative Example I that uses separate surfactant-containing resin and wax emulsions. The toner of Example V exhibits significantly improved performance in additive charging at low temperature/moderate humidity conditions, and exhibits significantly improved relative humidity sensitivity as exhibited by the RH ratio. The toner of Example V also exhibits improved blocking performance at high temperature/high humidity conditions wherein a lower blocking value is indicative of freer powder flow.
SEM micrographs of the produced toners were made. Inspection of the micrographs shows that the surface of the toner of Example III is significantly cleaner than the surface of the toner of Comparative Example I. That is, in the toner of Example III, the wax appears to be more uniformly incorporated into the toner particles, as compared to wax particles being adhered to the surface of the toner of Comparative Example I. The surface of the toner of Example III is thus smoother as compared to a relatively bumpy surface for the toner of Comparative Example I.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
