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Patent US4386147 - Resin having certain weight average to number average molecular weight ratio - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsThe present invention relates to a method of fixing a toner image onto a paper bearing said image with the use of a particular toner containing a colorant and a resin wherein the resin contains at least one particular type of polymer which has a Mw/Mn ratio of about 3.5 to 40 wherein the Mn value is...http://www.google.com/patents/US4386147?utm_source=gb-gplus-sharePatent US4386147 - Resin having certain weight average to number average molecular weight ratioAdvanced Patent SearchPublication numberUS4386147 APublication typeGrantApplication numberUS 06/320,188Publication dateMay 31, 1983Filing dateNov 12, 1981Priority dateApr 10, 1974Fee statusPaidAlso published asDE2515665A1, DE2515665B2, US4486524Publication number06320188, 320188, US 4386147 A, US 4386147A, US-A-4386147, US4386147 A, US4386147AInventorsRyubun Seimiya, Yutaka Yamada, Makoto Tomono, Noriyoshi Tarumi, Yasuyuki Fujisaki, Minoru Takahashi, Hiroshi Ogawara, Hirozo FunakiOriginal AssigneeKonishiroku Photo Industry Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (8), Referenced by (29), Classifications (10), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetResin having certain weight average to number average molecular weight ratioUS 4386147 AAbstract The present invention relates to a method of fixing a toner image onto a paper bearing said image with the use of a particular toner containing a colorant and a resin wherein the resin contains at least one particular type of polymer which has a Mw/Mn ratio of about 3.5 to 40 wherein the Mn value is between about 2,000 and 30,000.
What we claim is: 1. A method of fixing a toner image on a sheet bearing said toner image comprising passing said sheet between heated fixing rollers, the toner image consisting essentially of a toner which comprises a colorant and a resin, said resin containing at least 60% by weight, based on the weight of said resin, of at least one polymer selected from the group consisting of (a) a copolymer of an aromatic vinyl monomer with at least one other α-methylene aliphatic monocarboxylic acid ester and (b) a copolymer wherein all of the monomers are α-methylene aliphatic monocarboxylic acid esters, said polymer having a weight average molecular weight (Mw)/number average molecular weight (Mn) ratio of from 3.5 to 40 wherein the number average molecular weight (Mn) is between about 2,000 and about 30,000.
4. The method according to claim 1, wherein said polymer has a softening point of from about 100� to about 170� C.
Advantageously, the resin composition comprises a uniform mixture of a polymer having a low degree of polymerization (low polymer) and a polymer having a high degree of polymerization (high polymer), said composition is characterized as having a number average molecular weight (Mn) in the range of between about 2,000 and 30,000, Mw/Mn ratio in the range of between about 3.5 to 40, and a glass transition point in the range of between about 20� to 120� C. Additionally, there is disclosed a process for the preparation of a resin composition comprising a uniform mixture of a low polymer and a high polymer characterized as having a number average molecular weight (Mn) in the range of between about 2,000 and 30,000, Mw /Mn ratio in the range of between about 3.5 to 40, and a glass transition point in the range of between about 20� and 120� C., which comprises polymerizing a mixed solution of 100 parts by weight of a polymerizable monomer and 5-60 parts by weight of a high polymer having a number average molecular weight in the range of between about 100,000 and 500,000.
More particularly, the resin composition in accordance with the present invention comprises a uniform mixture of a low polymer and a high polymer having a number average molecular weight (Mn) of between about 2,000 and 30,000 and a ratio, obtained by dividing (Mw) by (Mn) (i.e. Mw/Mn), of between about 3.5 and 40, preferably between about 4 and 30. All the values for Mn and Mw as described herein are values measured by gel permeation chromatography (GPC) under the following conditions: 3 mg of a sample resin in solution form are injected into the solvent tetrahydrofuran having a temperature of 25� C. and a rate of flow of 1 ml/min such that the concentration of the sample is maintained at about 0.4 g/dl.
The measurement conditions are selected such that the molecular weight distribution of the sample is within the range where a linear relationship is developed between logarithmic values of molecular weight and count numbers in a calibration curve prepared with several different monodisperse polystyrene standard samples. In addition, reliability of such measurement can be confirmed by testing a NBS 705 polystyrene standard sample (Mw=28.8�104, Mn=13.7�104, Mw/Mn-2.11) under the same conditions. This sample gives a Mw/Mn value of 2.11+0.10.
As previously stated, the resin composition in accordance with the present invention has Mn and Mw/Mn values within a specific range. Additionally, the resin composition is required to have a glass transition point in the range of between about 20� and 120� C. A resin composition comprising a uniform mixture of a low polymer and a high polymer and meeting the aforementioned requirements for Mn, Mw/Mn, and glass transition point is extremely useful as a base resin for a toner of electrophotography. Thus, the resin composition in accordance with the present invention is easily ground but withstands excessive grinding into a powder having excessibely fine particles. In other words, it is possible to obtain a powder having a high yield of particle sizes within the desired range. When the present resin composition is used as a toner for dry type electrophotography, it withstands crushing caused by friction and thus, does not form excessively fine particles.
Especially good results are obtained when the resin of this invention has a softening point of about 100� to about 170� C. as measured according to the Ball and Ring method. The preferred softening point varies to some extent depending on the kind of the monomer included as the resin constituent and other factors. Moreover, use of a resin having a glass transition point of about 20� to about 120� C. is especially effective. In case the resin of this invention has a softening point lower than 100� C., the resin tends to be excessively pulverized and a photoconductive photosensitive plate is readily stained by the toner filming. When the softening point of the resin exceeds 170� C. pulverization is made difficult because of the hardness of the resin and a large heat is required at the fixing step, causing a defect of a low fixing efficiency. When the glass transition point of the resin is lower than 20� C., since the toner is generally stored at a temperature lower than 40� C., agglomeration of the toner particles occurs during storage by the cold flow phenomenon. When the glass transition point of the resin exceeds 120� C., it is necessary that the fixing operation is performed at the temperature higher than 250� C. because the softening point of the toner becomes higher correspond to the glass transition point. Accordingly if the material of the fixing roller is other than a metal, for example, Teflon (polytetrafluoroethylene manufctured by Du Pont), the roller material is readily worn away at temperatures higher than 250� C. and is decomposed at such temperatures. Therefore, there is brought about a disadvantage that elevation of the fixing temperature is limited by the roller-constituting material and the fixation cannot be accomplished sufficiently when the fixation is conducted at a high speed.
In such a uniform mixture, the high molecular weight portion and the low molecular weight portion together form a complete whole. The high molecular weight portion contributes to the protection of the resin composition against reduction of the cohesive force at the time of melting. The low molecular weight portion insures proper melting in that the resin composition begins to melt at a relatively low temperature but does not lose its cohesive force when the temperature rises. Also, the high molecular weight portion adds toughness to the resin composition. The low molecular weight portion allows the resin to be easily ground. These characteristics permit the formation of particles having the desired particle size. In some instances it may be preferable to employ the resin composition having a softening point, as measured by the ring and ball method, in the range of between about 100� and 170� C.
The process for the preparation of the resin composition in accordance with the present invention comprises dissolving a high polymer in a polymerizable monomer to form a mixed solution and subjecting the resultant mixed solution to polymerization. The high polymer used in this process preferably has a number average molecular weight in the range of between about 100,000 and 500,000 and is preferably used in an amount in the range of between about 5 and 60 parts by weight per 100 parts by weight of the polymerizable monomer. The polymerization is carried out under such conditions that the resultant resin composition has an Mn value of between about 2,000 and 30,000 a Mw/Mn value of between about 3.5 and 40, and a glass transition point of between about 20� and 120� C. If a standard polymerization process is employed wherein a polymerizable monomer is directly polymerized into a polymer, the value of Mn can be varied over a wide range by varying the polymerization conditions. However, Mw/Mn values can only be obtained in the range of between about 1.5 and 3.0.
Synthesis Example 1 10 parts of polystyrene, having a number average molecular weight of 12�104, was added to and dissolved in the monomer-benzoyl peroxide mixture, shown below in column A of Table 1, to obtain a mixed solution. The solution was suspended and dispersed in 200 parts of water having dissolved therein 0.5 part of a partially saponified polyvinyl alcohol. The resultant mixture was subjected to polymerization at a polymerization temperature of 30� C. to obtain resin composition A consisting of a uniform mixture of a low polymer and a high polymer.
TABLE 1______________________________________          A      B         C______________________________________Polystyrene      10 parts  0 part.sup.                                0 part.sup.Monomer: Styrene         70 parts 70 parts  70 parts n-Butyl methacrylate            30 parts 30 parts  30 partsMethylstyrene     5 parts  5 parts   3 partsBenzoyl peroxide  3 parts  3 parts   2 partsPhysical properties: Mn              1.1 � 104                     1.1 � 104                               2.3 � 104 Mw/Mn           4.2      2.0       2.1 Glass transition temperature             72� C.                      72� C.                                72� C. Softening point by the            124� C.                     115� C.                               125� C. ring and ball method______________________________________
Upon melting, the behavior of resin composition A and resins B and C were checked by use of the Koka flow tester (diameter of outlet nozzle 1 mm; length of outlet nozzle 1 cm; plunger pressure 100 kg/cm2 ; rate of temperature increase 6� C./min.). Both resin composition A and resin B were found to begin to melt at approximately 100� C., while resin C did not begin to melt until the temperature reached approximately 110� C.
Synthesis Example II 37.5 parts of styrene, 30 parts of n-butyl acrylate, 7.5 parts of glycidyl methacrylate and 0.2 part of benzoyl peroxide were mixed together in a reaction vessel. The mixture was polymerized at 30� C. until a polymerization degree of 20% was achieved. Thereafter, the reaction mixture was cooled and charged with 10 parts of styrene, 16 parts of n-butyl acrylate and 14 parts of glycidyl methacrylate to provide a mixed solution. The thus obtained mixed solution was found to consist of 15 parts of a high polymer (monomer composition: styrene/n-butyl acrylate/glycidyl methacrylate=50/40/10; Mn 12�104), 40 parts of styrene, 40 parts of n-butyl acrylate and 20 parts of glycidyl methacrylate. 3 parts of benzoyl peroxide were added to the mixed solution and the resultant mixture, at its boiling temperature, was continously added dropwise for four hours to 200 parts of toluene. After the dropwise addition was completed, the mixture was kept at the boiling temperature for an additional two hours to complete polymerization. The resultant reaction mixture was dried in a vacuum to remove the toluene. Resin composition D was obtained consisting of a uniform mixture of a low polymer and a high polymer.
For the purpose of comparison, 3.1 parts of benzoyl peroxide were added to a monomer mixture consisting of 40 parts of styrene, 40 parts of n-butyl acrylate, and 20 parts of glycidyl methacrylate. The resultant mixture was added dropwise to 200 parts of toluene in the same manner as described above and then polymerized to obtain resin E. The value of Mn was 5500 for resin composition D and 8000 for resin E. The value of Mw/Mn was 3.2 for resin composition D and 2.4 for resin E. The glass transition temperature was 23� C. for both resin composition D and resin E.
Each of the thus obtained powdered products was applied to an iron plate and heated to 200� C. The powder coating composition based on resin E was found to show resin hanging and uneven thickness at the edge portions. The powder coating composition based on resin composition D did not show such drawbacks and provided a coating film with a beautiful, smooth surface.
SYNTHESIS EXAMPLE III 40 parts of styrene, 30 parts of methyl methacrylate, 30 parts of n-butyl methacrylate and 0.17 part of azobisisobutyronitrile were added to, suspended, and then dispersed in 200 parts of water containing 0.5 part of a partially saponified polyvinyl alcohol. The resultant mixture was subjected to polymerization at 75� C. to obtain a high polymer having an Mn value of 2.0�104.
Subsequently, 10 parts of the thus obtained high polymer were mixed with the monomer-azobisisobutyronitrile mixture, shown in column F of Table 2, to obtain a mixed solution. The mixed solution was added to, suspended, and then dispersed in 200 parts of water containing 0.5 part of a partially saponified polyvinyl alcohol. The resultant mixture was subjected to polymerization at 75� C. to obtain a resin composition consisting of a uniform mixture of a low polymer and a high polymer.
TABLE 2______________________________________             F      G______________________________________Polystyrene         10 parts  0 part.sup.Monomer: Styrene            40 parts 40 parts Methyl methacrylate               30 parts 30 parts n-Butyl methacrylate               30 parts 30 partsMethylstyrene        6 parts  3 partsAzobisisobutyronitrile               4.5 parts                         3 partsPhysical properties: Mn                 2.2 � 104                        2.9 � 104 Mw/Mn              4.6      2.3 Glass transition temperature                73� C.                         73� C. Softening point by the ring               134� C.                        136� C. and ball method______________________________________
5 parts of Diablack SH (manufactured by Mitsubishi Kasei, Co., Ltd.) and 2.5 parts of Oilblack BW (manufactured by Orient Kaguka, Co., Ltd.) were melt-blended with individual samples of 100 parts each of resin composition F and resin G. The resultant blends were ground for 50 hours by a ball mill. The average particle size of the powder containing resin composition F was 15.2 microns, whereas that obtained from resin G was 10.2 microns. The yield of the powder having a desired particle size distribution in the range of between about 10 and 20 microns was about 75% for resin composition F and 35% for resin G. The above-mentioned particle size range is suitable for use in a dry-type electrophotographic toner. In addition, the sample containing resin G showed a large amount of finely divided particles having a size of less than 10 microns. These fine particles are undesirable because they produce a blocking effect. The sample containing resin composition F showed few of these finely divided particles and therefore, blocking does not occur. The thus obtained powder samples, having a particle size distribution in the range of between about 10 and 20 microns for use as a toner, were subjected to fixing at different temperatures in the range of between about 150� and 200� C. The toner containing resin G exhibited excessive fluidity at higher temperatures, a decrease in resolution, excessive luster of the resulting image, etc. The toner containing resin composition F exhibited beautiful images over the entire range of fixing temperatures.
SYNTHESIS EXAMPLE IV 0.1 of a partially saponified polyvinyl alcohol (Gosenol GH-17 manufactured by Japanese Synthetic Rubber) was charged in a separable flask having a capacity of 1 liter, and dissolved in 100 ml of distilled water. Then, a monomer mixture A indicated in the following Table was added to the solution to suspend and disperse the mixture in the solution. The atmosphere was replaced by nitrogen gas and the temperature was elevated to 80� C. At this temperature polymerization was carried out for 15 hours. The reaction mixture was cooled to 40� C., and a monomer mixture B indicated in the following Table was added to the reaction mixture and the mixture was agitated at 40� C. for 2 hours. Separately, an aqueous solution of 0.4 g of a partially saponified polyvinyl alcohol (Gosenol GH-17) in 100 ml of distilled water was prepared. The so formed aqueous solution was added to the above suspension. Then, the temperature was elevated again to 80� C. and this temperature was maintained for 8 hours to effect the polymerization. Then, the temperature was further elevated to 95� C. and this temperature was maintained for 2 hours to complete the polymerization. The reaction product was cooled, dehydrated, washed repeatedly and dried to obtain a resin in which the Mw/Mn ratio was 5.4, the Mn value was 1.1�104 and the softening as measured according to the ball and ring method was 140��2� C.
EXAMPLE 1 100 parts of polystyrene (A) [Mw/Mn=3.7; Mn=9600; softening point as measured according to the ball and ring method (hereinafter referred to as "B & R")=120�2� C.; glass transition point (hereinafter referred to as "Tg")=97� C.] was mixed with 6 parts of Peares 155 (carbon black manufactured by Columbia Carbon) and 3 parts of Nigrosine Base EX (Nigrosine dye manufactured by Orient Kagaku), and the mixture was treated in a ball mill for about 24 hours and kneaded with a hot roll. Then, the mixture was cooled and pulverized to obtain a toner sample of this invention having an average particle size of about 13 to 15 microns. The above procedures were repeated in the same manner by using instead of the polystyrene (A) polystyrene (B) (Mw/Mn=2.6; Mn=12000; B & R=125�2� C.; Tg=97� C.), to obtain a comparative sample.
4 parts each of the thus obtained toner samples were mixed separately with 96 parts of an iron powder carrier having an average particle size of about 50 to about 80 microns to form 2 kinds of developers. Electrostatic latent images formed by a customary electrophotographic method were developed with these two toners respectively, and the resulting toner images were transferred on transfer sheets and fixed by fusing the toner images by a pressing contact with a fixing roller having a surface composed of FEP, which was maintained at 165� to 175� C. In order to examine whether or not the fixed toner was re-transferred to the roller surface to cause the offset phenomenon, just after completion of the fixing operation, transfer sheets free of a toner image were caused to have a pressing contact with the roller under the same conditions as above, and it was checked whether or not the transfer sheets were stained by the offset phenomenon.
EXAMPLE 2 Two toners were prepared in the same manner as Example 1 except that polystyrene (A1) (Mw/Mn-4.5; Mn=8300; B & R=125�2� C.; Tg=97� C.) and polystyrene (A2) (Mw/Mn=25; Mn=1900; B & R=125�2� C.; Tg=-) were used separately instead of the polystyrene (A) used in Example 1.
The offset characteristics of these toners were examined in the same manner as in Example 1 except that a fixing roller having a surface composed of Daifuron was used as the fixing roller and the fusing temperature was changed to 180� to 190� C. It was confirmed that in each of the two samples the offset phenomenon was not caused at all.
EXAMPLE 3 100 parts of a styrene (70 parts)-butyl methacrylate (30 parts) copolymer (A) (Mw/Mn=4.6; Mn=17000; B & R=140�2� C.; Tg=74� C.) was mixed with 5 parts of Dia Black SH (carbon black manufactured by Mitsubishi Kasei) and 2.5 parts of Oil Black BW (Nigrosine dye manufactured by Orient Kagaku), and the mixture was treated in the same manner as in Example 1 to obtain a toner sample of this invention. The above procedures were repeated similarly by using instead of the copolymer (A) a styrene (70 parts) butyl methacrylate (30 parts) copolymer (Mw/Mn=3.0; Mn=23000; B & R=140�2� C.; Tg=74� C.), to obtain a comparative toner.
The offset characteristics of these two toners were examined in the same manner as in Example 1 except that the fusing temperature was changed from 200� to 210� C. In the case of the comparative sample, the offset phenomenon was observed, but in the case of the toner sample of this invention it was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 4 100 parts of a styrene (50 parts) methyl methacrylate (20 parts)-butyl methacrylate (30 parts) copolymer (A1) (Mw/Mn=5.4; Mn=11000; B & R=140�2� C.; Tg=72� C.) was mixed with 5 parts of Dia Black SH and 2 parts of Oil Black BW and the mixture was treated in the same manner as in Example 1 to obtain a toner sample of this invention. The above procedures were repeated in the same manner by using instead of the copolymer (A1) a styrene (50 parts)-methyl methacrylate (20 parts)-butyl methacrylate (30 parts) copolymer (B1) (Mw/Mn=2.8; Mn=19000; B & R=140�2� C.; Tg=72� C.) to obtain a comparative sample toner.
The offset characteristics of these two toners were examined in the same manner as in Example 1 except that a roller having a surface composed of Daifuron was used as the fixing roller and the fusing temperature was changed to 190� to 200� C. In the case of the comparative sample, occurrence of a conspicuous offset phenomenon was observed, but in the case of the toner sample of this invention it was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 5 A toner sample was prepared in the same manner as in example 4 except that a styrene (50 parts)-methyl methacrylate (20 parts)-butyl methacrylate copolymer (A2) (Mw/Mn=6.5; Mn=9800; B & R=140�2� C.; Tg=72� C.) was used instead of the copolymer (A1), Peares 155 was used instead of Dia Black SH (manufactured by Orient Kagaku) and Oil Black BS (manufactured by Orient Kagaku) was used instead of Oil Black BW.
The offset characteristics of the so obtained toner were examined in the same manner as in Example 1 except that the fusing temperature was changed from 210� to 220� C. It was found that the offset phenomenon was not caused at all.
EXAMPLE 6 A toner sample was prepared in the same manner as in Example 4 except that a styrene (50 parts)-methyl methacrylate (20 parts)-butyl methacrylate (30 parts) copolymer (A3) (Mw/Mn=8.2; Mn=9100; B & R=140�2� C.; Tg=72� C.) was used instead of the copolymer (A1), MA-8 (carbon black manufactured by Mitsubishi Kasei) was used instead of Dia Black SH and Oil Black BS (Nigrosine dye manufactured by Orient Kagaku) was used instead of Oil Black BW.
The offset characteristics of the so obtained toner were examined in the same manner as in Example 1 except that the fusing temperature was changed from 230� to 240� C. It was confirmed that the offset phenomenon was not caused at all.
EXAMPLE 7 85 parts of a methyl methacrylate (82 parts)-butyl methacrylate (18 parts) copolymer (A4) (Mw/Mn=4.2; Mn=8500; B & R=135�2� C.; Tg=85� C.) and 15 parts of the same polystyrene (B) as used in Example 1 were mixed with 4.5 parts of MA-8 and 1.5 parts of Nigrosine Base EX, and the mixture was treated in the same manner as in Example 1, to obtain a toner sample of this invention. The above procedures were repeated similarly by using 10 parts of the copolymer (A4) and 90 parts of the polystyrene (B), to obtain a comparative toner sample. Resin components of these samples and comparative sample had the following properties:
Resin of Sample Mw/Mn=3.9; Mn=8900; B & R=135�2� C.; Tg=85� C.
Resin of Comparative Sample Mw/Mn=2.7; Mn=11500; B & R=125�2� C.; Tg=96� C.
The offset characteristics of these two toners were examined in the same manner as in Example 1 except that a roller having a surface composed of FEP was used as the fixing roller and the fusing temperature was changed from 160� to 170� C. In the case of the comparative sample, it was found that the offset phenomena was conspicuous, but in the case of a sample of this invention it was confirmed that the offset phenomenon was not caused at all.
EXAMPLE 8 50 parts of the same polystyrene (A1) as used in Example 2 and 50 parts of the same copolymer (A4) as used in Example 7 were mixed with 5 parts of Peares 155 and 2 parts of Nigrosine Base EX, and the mixture was treated in the same manner as in Example 1, to obtain a toner.
The offset characteristics of the so obtained toner were examined in the same manner as in Example 1 except that a roller having a surface composed of Daifuron was used as the fixing roller and the fusing temperature was changed from 180� to 190� C. It was confirmed that the offset phenomenon was not caused at all.
EXAMPLE 9 100 parts of a styrene (80 parts)-vinyl toluene (20 parts) copolymer (A5) (Mw/Mn=4.0; Mn=14000; B & R=150�2� C.; Tg=100� C.) was mixed with 6 parts of Peares 155 and 2.5 parts of Nigrosine Base EX, and the mixture was treated in the same manner as in Example 1 to obtain a toner sample of this invention. The above procedures were repeated similarly by using instead of the copolymer (A5) a styrene (80 parts)-vinyl toluene (20 parts) copolymer (B2) (Mw/Mn=3.3; Mn=17000; B & R=150�2� C.; Tg=100� C.), to obtain a comparative toner sample.
The offset characteristics of these two toners were examined in the same manner as in Example 1 except that the fusing temperature was changed from 190� to 200� C. In the case of the comparative sample, it was found that the offset phenomenon was conspicuous, but in the case of the sample toner of this invention, it was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 10 95 parts of a styrene (85 parts)-acrylonitrile (15 parts) copolymer (A6) (Mw/Mn=10; Mn=8500; B & R=145�2� C.; Tg=-) and 5 parts of poly (methyl methacrylate) (Mw/Mn=20; Mn=3200; B & R=145�2� C.; Tg=-) were mixed with 6 parts of Dia Black SH and 2.5 parts of Oil Black BS, and the mixture was treated in the same manner as in Example 1 to obtain a toner sample of this invention. The above procedures were repeated similarly by using instead of the copolymer (A6) a styrene (85 parts)-acrylonitrile (15 parts) copolymer (B3) (Mw/Mn=2.5; Mn=22000; B & R=145�2� C.; Tg=103� C.), to obtain a comparative toner sample. The resin components of these samples and comparative sample had the following characteristics:
Resin of Sample Mw/Mn=11; Mn=7800; B & R=145�2� C.; Tg=103� C.
Resin of Comparative Sample Mw/Mn=3.3; Mn=17000; B & R=145�2� C.; Tg=103� C.
The offset characteristics of these two toners were examined in the same manner as in Example 1 except that a roller having a surface composed of Daifuron was used as the fixing roller and the fusing temperature was changed to 190� to 200� C. In the case of the comparative sample, it was found that the offset phenomenon was conspicuous, but in the case of the sample of this invention, it was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 11 100 parts of the same polystyrene (A1) as used in Example 2 was mixed with 6 parts of MA-8 and 3 parts of Nigrosine Base EX, and the mixture was treated in the same manner as in Example 1 to obtain a sample A. The above procedures were repeated similarly by further adding 5 parts of Hoechst Wax C (amide was manufactured by Hoechst Japan), to obtain a sample B. The above procedures were repeated similarly by using 2 parts of zinc stearate instead of the Hoechst Wax C to obtain a sample C.
The offset characteristics of these three samples were examined in the same manner as in Example 1 except that a roller having a surface composed of Daifuron was used as the fixing roll and the fusing temperature was changed to 180� to 190� C. In each of these samples, it was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 12 100 parts of the same copolymer (A2) as used in Example 5 was mixed with 5 parts of Dia Black SH and 2 parts of Oil Black BS, and the mixture was treated in the same manner as in Example 1 to obtain a toner sample A. The above procedures were repeated similarly by further adding 1 part of barium stearate to obtain a toner sample B. The above procedures were repeated similarly by using 4 parts of Plast Flow (ethylene-bis-stearoyl amide manufactured by Nitto Kagaku) instead of the barium stearate to obtain a toner sample C.
The offset characteristics of the so obtained three toner samples-were examined in the same manner as in Example 1 except that a roller having a surface composed of FEP was used as the fixing roller and the fusing temperature was changed to 180� to 190� C. In each of these toner samples, it was confirmed that the offset phenomenon was not caused to occur at all. When these toners were used repeatedly, it was found that in the case of samples B and C the frictional charge characteristics were not changed for a longer time than in the case of the sample A and the samples B and C had a longer life than the sample A.
EXAMPLE 13 95 parts of a styrene (85 parts)-ethylhexyl acrylate (15 parts) copolymer (Mw/Mn=4.5; Mn=11000; B & R=135�2� C.; Tg=74� C.) and 5 parts of polyvinyl butyral (Mw/Mn=2.4; Mn=23000; B & R=115�2� C.; Tg=62� C.) were mixed with 6 parts of Peares 155, 1.5 parts of Nigrosine Base EX and 5 parts of Plast Flow, and the mixture was treated in the same manner as in Example 1 to obtain a toner.
The offset characteristics of the so obtained toner were examined in the same manner as in Example 1 except that a roller having a surface composed of FEP was used as the fixing roller and the fusing temperature was changed to 160� to 170� C. It was confirmed that the offset phenomenon was not caused to occur at all.
EXAMPLE 14 100 parts of a styrene (95 parts)-lauryl methacrylate (5 parts) copolymer (Mw/Mn=4.6; Mn=10000; B & R=135�2� C.; Tg=91� C.) was mixed with 5 parts of Ma-8, 2.5 parts of Nigrosine EX and 5 parts of Hoechst Wax C, and the mixture was treated in the same manner as in Example 1 to obtain a toner.
The offset characteristics of the so obtained toner were examined in the same manner as in Example 1 except that a roller having a surface composed of FEP was used as the fixing roller and the fusing temperature was changed to 170� to 180� C. It was confirmed that the offset phenomenon was not caused to occur at all.
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fixable at low temperature, impact strength, stability, durabilityUS5714542 *Mar 6, 1996Feb 3, 1998Sanyo Chemical Industries, Ltd.Resin composition for electrophotographic tonerUS5733701 *Sep 5, 1996Mar 31, 1998Minolta Co., Ltd.Non-contact hot fusing tonerUS5744276 *Mar 30, 1994Apr 28, 1998Canon Kabushiki KaishaElectrophotographyUS5807653 *Apr 22, 1997Sep 15, 1998Minolta Co., Ltd.Blend of hydrocarbon wax and magnetic powderUS5824446 *Apr 22, 1997Oct 20, 1998Minolta Co., Ltd.Toners for developing electrostatically charged imagesUS5851714 *Mar 28, 1997Dec 22, 1998Canon Kabushiki KaishaToner for developing electrostatic image and fixing methodUS5932386 *Dec 5, 1997Aug 3, 1999Minolta Co., Ltd.Non-contact hot fusing tonerUS5942366 *Feb 12, 1998Aug 24, 1999Canon Kabushiki KaishaElectrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compoundUS6300024Jun 28, 2000Oct 9, 2001Canon Kabushiki KaishaToner, two-component type developer, heat fixing method, image forming method and apparatus unitUS6537716Dec 4, 1996Mar 25, 2003Canon Kabushiki KaishaToner for developing electrostatic images and heat fixing methodUS7442480 *Apr 22, 2003Oct 28, 2008Kao CorporationPositively chargeable tonerUS7569319Nov 26, 2003Aug 4, 2009Mitsui Chemicals, Inc.Binder resin for toner and electrophotographic toner for static charge image development containing the sameUS8685602Aug 16, 2011Apr 1, 2014Fuji Xerox Co., Ltd.Toner for electrophotography, developer for electrophotography, toner cartridge, image forming apparatus, and image forming methodEP0170421A1 *Jul 1, 1985Feb 5, 1986Fuji Xerox Co., Ltd.Dry toner* Cited by examinerClassifications U.S. Classification430/124.31, 430/109.3International ClassificationG03G9/087Cooperative ClassificationY10S430/105, G03G9/08711, G03G9/08708, G03G9/08702European ClassificationG03G9/087B, G03G9/087B2B2, G03G9/087B2BLegal EventsDateCodeEventDescriptionSep 26, 1994FPAYFee paymentYear of fee payment: 12Oct 22, 1990FPAYFee paymentYear of fee payment: 8Sep 22, 1989ASAssignmentOwner name: KONICA CORPORATION, JAPANFree format text: RELEASED BY SECURED PARTY;ASSIGNOR:KONISAIROKU PHOTO INDUSTRY CO., LTD.;REEL/FRAME:005159/0302Effective date: 19871021Nov 18, 1986FPAYFee paymentYear of fee payment: 4Apr 9, 1985ASAssignmentOwner name: KONISHIROKU PHOTO INDUSTRY CO., LTD., A CORP OF JAOwner name: SEKISUI CHEMICAL CO., LTD., A CORP OF JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST. JOINTLY;ASSIGNOR:KONISHIROKU PHOTO INDUSTRY CO., LTD.;REEL/FRAME:004385/0481Effective date: 19850308Nov 12, 1981ASAssignmentOwner name: KONISHIROKU PHOTO IND. CO., LTD., A CORP. OF JAPFree format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:SEIMIYA, RYUBUN;YAMADA, YUTAKA;TOMONO, MAKOTO;AND OTHERS;REEL/FRAME:003946/0034Effective date: 19811023Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SEIMIYA, RYUBUN;YAMADA, YUTAKA;TOMONO, MAKOTO;AND OTHERS;REEL/FRAME:003946/0034Owner name: KONISHIROKU PHOTO IND. CO., LTD., JAPANRotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google