Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles

Definitions

• the invention relates to a developer of electrostatic latent images in the field of the electrophotography, electrostatic recording and electrostatic printing.
• the visible image is transferred to transform materials including flimsy (transferring process).
• the image is then fixed by appropriate fixing methods such as heating, press­ing, etc., (fixing process).
• the developing method applicable to the electronic photographic method can be broadly divided into the dry development method and wet development method. Further, the former can be separated into a method using one component developer and a method using two component developer.
• the group of two component developers if classified by the toner transportiog system, includes the magnetic brush development method in which powder is applied as the carrier; cascade developing method using a more or less coarse bead carrier; and fur brush development method using less fiber.
• toner As toner applicable to these development methods, fine powder made by dispersing coloring agents like dyestuffs or pigment into natural or synthesized thermoplastic resin was used.
• various kinds of additives such as coloring agents, charge control­lers, wax, etc., are mixed into and dispersed in binding agents of the polystyrene or polyester family. The matter thus produced is crushed into particles of 1 ⁇ 30 ⁇ m.
• the particles are applied as toner.
• toner containing magnetic particles such as magnetite, etc.
• toner is used. And toner itself is absorbed and held by the magnetic roll and transferred to the image surface.
• toner is usually mixed into carrier particles such as glass beads, iron powders, and by static attraction caused by friction at the time held in the carrier and transferred to the latent image surface.
• carrier particles such as glass beads, iron powders
• the polarity is determined by the charge polarity of the latent image and definite polarity, positive or nagative, and an amount of charge is requested to be given.
• the frictionally charging property of the carrier, its external material and resin, which is a compo­ nent of toner can be used but this method is not satisfac­tory because the toners, charge is too small and it is difficult to reach a desired amount of charge quickly.
• charge controller is added to control the charging property.
• a compound with electron donor radical-like nigrosine dye is effective and for negative electrification, electron accepting organic complex includ­ing oil-soluble metal-inclusive dyestuffs are widely used.
• nigrosine dyes compatibility with resin is usually not good and, therefore, it is applied after being denatured by oleic acid, stearic acid, etc., in many cases.
• charge controllers of positive electrification we have fatty acid amine, quaternary ammonium salt, Fettshwarz HBW, Sudan teak schwarz BBC and brilliant spirit
• charge controllers of negative electrification colloidal silica, fatty acid metallic salt, mono-azo coloring metal complex salt, chlorinated paraffin, chlorinated polyester, chromogen shwarz, ETCO, Azo oil black, etc.
• charge controllers of negative electrification colloidal silica, fatty acid metallic salt, mono-azo coloring metal complex salt, chlorinated paraffin, chlorinated polyester, chromogen shwarz, ETCO, Azo oil black, etc.
• Many of these electrification controllers stem from the dyestuff and pigment group and generally have complicated structures and strong properties of coloring. In case of chromatic toner, a colored compound cannot be used and colorless or light colored electrification controllers have been studied for use.
• quaternary ammonium salt vinyl pyridine, dehydrated condensate of ortho positioned amine and decar­bonate acid, etc.
• Dyes or pigments are, although not completely satisfactory, applied presently bacause better materials are not available.
• charge controllers are applied usually after being mixed with thermoplastic resin, dispersed by thermo melting and kneading, pulverized and adjusted to a proper particle size according to the requirements. Although it is inevitable that these dyes, pigments and charge controllers will be used, many problems arise therefrom.
• the molecular structure is so complicated that the property is unstable, the quality is changed by thermo melting and kneading, the performance is apt to change according to the conditions of temperature and humidity, and the quality and property of electronic pic­tures are easily lowered as a result of increased frequency of copying.
• the second problem involves the difficulty in dispersing these charge controllers evenly in thermoplastic resin as it causes a difference in the amount of frictional charges between particles and results in lowered image quality.
• the third problem is that because most charge controllers are hydrophilic and not well dispersed in resin, they are exposed to the surface of toner particles. There­fore, the volume of charged electricity in toner is lowered due to charge controllers having absorbed humidity under high humidity conditions. A high quality image cannot be obtained.
• the fourth problem is that most dyes and pigments generally known as charge controllers are of chromatic color or dark color and cannot be contained in toners which have bright and desired colors.
• the fifth problem is if toner mixed with charge controllers is used for a long time, the charge controllers adhere to the face of the photoactive substances or promote adherence of toner to the photoactive substances, exert harmful effects upon their formation of electrostatic image, (photoactive substance filming) damage the face of the photoactive substnace or cleaning beads, or accelerate the abrasion of the material portion thereof. As stated above, not a few undesirable actions are exerted on the cleaning process of duplicating machines.
• color toners those made by dispersing or dissolving various kinds of dyestuffs or pigments into binder resin are used.
• toners especially when the pur­pose is to reproduce full color images by using the three primary colors, the following is very important. That is, not only are all of the basic performances including the above mentioned charging property good, but it also repro­duces color which the original images had and, therefore, spectral reflectancies of each color draw almost idealistic curves and very low saturation of black is created. These are very important.
• Japanese patent publication No. 60-112051 disclosed an even and sufficient positively- charged de­veloper made as follows:
• the purpose is to avoid the offsetting phenomena in the heat-roller fixing method.
• Binding resin to be used is copolymer resin of copoly­mer-natured monomer having specific polyester resin and tertiary amino group and hydrophobic copolymer-natured mono­mer.
• an evenly and sufficiently positively-charged developer toner is made, without using traditional charge controllers, by combining with carrier covered with copoly­mer resin of vinyl chloride and vinyl acetate.
• the composing ratio between copolymer-­natured monomer with polyester resin and tertiary amino group and copolymer resin of hydrophobic copolymer-natured monomer is 10 to 50 weight percent : 50 to 90 weight per­cent, and the softening point in the ring and ball system is within the limit of 100 to 180°C.
• the purpose of this invention is related to posi­tively charged dry developers with a stable charging proper­ty by which the above mentioned traditional tasks can be settled. Especially, it is to provide a more improved posi­ tively charged full color developer.
• Another purpose of this invention is to prepare a developer with excellent transparency at the time when it is laid on top of another and also when transferred to and fixed on a transparency.
• the additional purpose of this invention is to provide a developer which enables development and transfer faithful to the static latent image, that is, a developer which is without fog or scattered toners at or around the edge and which can obtain high density image and reproduce excellent half-tones.
• this invention is purposed to offer a developer which maintains its initial property even after having been used for a long period of time, which is without toner cohesion and which can be preserved safely.
• a binder resin comprising (A) a polyester resin and (B) a styrene-acrylic resin obtained by co-polymerizing a styrene compound or/and an acrylic compound and a monomer having an amino group, at a weight ratio of (A) to (B) ranging from 55:45 to 95:5, both resin (A) and resin (B) and a dyestuff or pigment of chromatic color.
• the carrier has been coated with a silicone resin being curable at the room temperature and heated at 180 degree C or higher.
• An alternative coating is a fluoro resin having 80 mole percent or more of fluorine atoms in the monovalent atoms attached to the carbon atoms.
• this invention is to prepare positively charged dry developers with the following properties:
• binding resin (the main content of toners) consists of polyester resin (A) and styrene acrylic resin (B) produced by copolymerizing copolymer-natured monomer containing the amino group.
• the weight ratio of resin (A) and (B) is within the range of 55 : 45 to 95 : 5, and the softening point (ring and ball method) is 110 degrees centigrade or less.
• the carrying agents to be mixed with the binding resin are dyes or pigments of chromatic colors.
• the main ingredients of binding resin in this invention are a mixture of polyester resin (A) and styrene-­acrylic resin (B), which are produced by polymerizing-­polymerization-natured monomer containing the amine group.
• Polyester resin (A) applied here is synthesized by a polycondensation reaction between polycarboxylic acid and polyhydric alcohol.
• group of polyvalent carbox­ylic acid the following carboxylic acid, carboxylic acid anhydride and low class alkylester of carboxylic acid can be applied; e.g., fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 3-isodecyl -1, 2, 5, 6 - hexanetetra carboxylic acid, succinic acid, isooctyl-succinic acid and adipic acid.
• polyhydric alcohol group the following are ap­plied, e.g., ethylene glycol, diethylene glycol, triethylene alcohol, propylene glycol, butanediol, neopentyl glycol, polyoxyethylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane, polyoxy propylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane, hydrogenated bisphenol A, glycerol and trimethylol propane.
• mono carboxylic acid or mono alcohol can be added as polyester materials.
• monomers of the styrene family such as styrene, P-methylstyrene, ⁇ -methylstyrene; esters of acrylic acid and methacrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate and 2-ethylhexyl acrylate.
• the weight composition of resin (A) and resin (B), (A) : (B) is 55 : 45 ⁇ 95 : 5, more preferably 65 : 35 ⁇ 90 : 10. If the ratio of resin (B) is 5 or less, the charged electrostatic capacity is not enough or the electro­static charge becomes negative. If the ratio of resin (B) is 45 or more, the property of dispersing or dissolving dyestuffs and/or pigment of polyester resin will be lost, and in case it is applied in color toners, saturation will be lost and the color will become dull. Furthermore, a defect of OHP's projected image becoming dark will be pro­duced. Therefore, it is undesirable.
• the softening point (SP) of resin (A) and (B) under the ring and ball method (JIS K-2207) should be 110°C or less. SP beyond the said limit will result in too much molar weight and spoiling due to entwinement of the high polymer chain, the rapidly melting property. Thus, the resulting image will lack transparency and be of dull color with low saturation. Especially those of SP over 130 degrees centi­grade are not desirable.
• coloring agents for color toners in this invention can be used as listed hereunder: For Yellow: C.I. Solvent Yellow-21, C.I. Solvent Yellow-114, C.I. Solvent Yellow-77, C.I. Pigment Yellow-12, C.I. Pigment Yellow-14, C.I. Disperse Yellow-164, etc.
• Magenta C.I. Solvent Red-49, C.I. Solvent Red-­128, C.I. Pigment Red-13, C.I. Pigment Red-48.2, C.I. Dis­perse Red-11, etc.
• Cyan C.I. Solvent Blue-25, C.I. Solvent Blue-94, C.I. Pigment Blue-15.3, etc.
• developer toners in this invention can offer more stabilized images by combination with carriers covered with specific cladding materials.
• carriers to be applied in this invention widely known carriers can be used, e.g., ferromagnetic materials including iron, ferrite, steel, magnetite, nickel, or glass, etc. Instances of the specific cladding materials are straight silicon resin, fluoro resin, etc.
• Silicon varnish curing under ordinary temperatures is silicon resin of the following chemical structural formu­la, including KR-114, KR-220, KR-251 and KR-255 (all of which are manufactured by Shin-etsu Chemical Co., Ltd.) (In this formula, R1 ⁇ R4 are hydrogen atoms, hydroxyl group, low class alkoxyl group with the number of carbons being 1 ⁇ 4, methyl group or phenylgroup.)
• the resin in case specific cladding material is fluoro resin, it is desirable for the resin to be fluoro resin, whose ratio of fluorine atoms in univalent atom connecting with carbon principal and side chains is 80 mole percent.
• fluoro resins examples include poly (tetra fluoro ethylene-vinylidene fluoride), poly (tetra fluoro ethylene - fluoro propylvinyl-ether) copolymer of methacrylic acid 2 - fluoro octyl ether and methacrylic acid n-butyl, and poly (tetra fluoro ethylene-hexa fluoro propylene).
• the above examples are used individually or in mixture.
• Iron powder (TSV-300) 1000 made by Nippon Teppun Co., Ltd., as being fluidizated on a fluid bed, was heated up to 60°C, maintained at the same temperature and sprayed with silicon resin (KR-252 of Shin-etsu Silicone Co., Ltd.) 10 (figured on the basis of resin contained therein) solution melted into 5% with toluene. After drying for 20 minutes, it was heat treated at 200°C for 30 minutes in an electric furnace. Thus, a silicone resin coat carrier was obtained.
• magenta toner was made by the same method as in Execution Example I. Next, developer was produced from said magenta toner 50.0 and silicone resin coat carrier 950 in Manufacturing Example I.
• magenta toner was produced by the same method as in Execution Example I. Then, de­veloper was manufactured from said magenta toner 50.0 and fluoro resin coat carrier 950 in Manufacturing Example 2.
• Cyanic toner was produced from the compounds of the above ingredients by the same method as that of Execution Example 1. Next, developer was produced from said cyanic toner 50.0 and fluoro resin coat carrier 950 stated in Manu­facturing Example 2.
• Example of Execution 4. ⁇ Composition of Toner> Polyester resin in Composition Example I 75.0 Styrene acrylic resin in Composition Example III 25.0 C.I. Solvent Yellow-114 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Yellow toner was produced from compounds of the above ingredients by the same method as stated in Execution Exam­ple I. Next, developer was produced from said yellow toner 50.0 and silicone resin coat carrier 950 in Manufacturing Example 1.
• Example of Execution 5. ⁇ Composition of Toner> Polyester resin in Composition Example II 80.0 Styrene acrylic resin in Composition Example IV 20.0 C.I. Pigment Red-13 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Magenta toner was produced from compounds of the above ingredients by the same method as stated in Execution Exam­ple 1. Next, developer was produced from said magenta toner 50.0 and silicone resin coat carrier 950 in manufacturing Example 1.
• Example of Execution 6. ⁇ Composition of Toner> Polyester resin in Composition Example II 75.0 Styrene acrylic resin in Composition Example III 25.0 C.I. Solvent Blue-15.3 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Cyanic toner was produced from compounds of the above ingredients by the same method as stated in Execution Exam­ple 1. Next, developer was produced from said cyanic toner 50.0 and fluoro resin coat carrier 950 in Manufacturing Example 2.
• Example of Execution 7. ⁇ Composition of Toner> Polyester resin in Composition Example II 60.0 Styrene acrylic resin in Composition Example IV 40.0 C.I. Pigment Blue-15.3 5.0 Viscol 660 (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Cyanic toner was produced from compounds of the above ingredients by the same method as stated in Execution Exam­ple I. Next, developer was produced from said cyanic toner 50.0 and coat carrier 950 (made by Nippon Teppun TSV-300).
• Example of Comparison 2 ⁇ Composition of Toner> Polyester resin in Composition Example II 40.0 Styrene acrylic resin in Composition Example III 60.0 C.I. Pigment Yellow-14 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Yellow toner was produced from compounds of the above ingredients by the same method as stated in Execution Exam­ple I. Next, developer was produced by said yellow toner 50.0 and fluoro resin coat carrier 950 stated in Manufactur­ing Example 2.
• Example of Comparison 3 ⁇ Composition of Toner> Styrene acrylic resin in Composition Example III 100.0 C.I. Pigment Red-13 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Magenta toner was produced from compounds of said ingredients by the method stated in Execution Example I. Next, developer was produced from said magenta toner 50.0 and silicon resin coat carrier 950 stated in Manufacturing Example I.
• Example of Comparison 4 ⁇ Composition of Toner> Polyester resin in Composition Example I 100.0 Pontron No. 7 (Made by Orient Co. Ltd., Nigrosine dyestuff) 2.0 C.I. Pigment Blue-15.3 5.0 Viscol 660P (Made by Sanyo Chemical Industries, Ltd.) 2.0
• Cyanic toner was produced from compounds of the above ingredients by the same method as stated in Enforcement Example I. Next, developer was produced from said cyanic toner 50.0 and fluoro resin coat carrier 950 in Manufactur­ing Example 2.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Developing Agents For Electrophotography (AREA)

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• 1988
  • 1988-11-02 JP JP63278105A patent/JP2733073B2/ja not_active Expired - Fee Related
• 1989
  • 1989-11-02 EP EP19890120305 patent/EP0367265B1/de not_active Expired - Lifetime
  • 1989-11-02 DE DE1989625670 patent/DE68925670T2/de not_active Expired - Fee Related

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