EP0640882B1 - Révélateur pour électrophotographie et procédé pour sa fabrication - Google Patents

Révélateur pour électrophotographie et procédé pour sa fabrication Download PDF

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Publication number
EP0640882B1
EP0640882B1 EP19940306341 EP94306341A EP0640882B1 EP 0640882 B1 EP0640882 B1 EP 0640882B1 EP 19940306341 EP19940306341 EP 19940306341 EP 94306341 A EP94306341 A EP 94306341A EP 0640882 B1 EP0640882 B1 EP 0640882B1
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EP
European Patent Office
Prior art keywords
toner
lactic acid
offset
preventer
resin
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EP19940306341
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German (de)
English (en)
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EP0640882A1 (fr
Inventor
Hideyuki C/O Toner Plant Of Tomoegawa Kubota
Eiichi C/O Sanjo Work Of Shimadu Corp. Ozeki
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Shimadu Corp
Tomoegawa Co Ltd
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Tomoegawa Paper Co Ltd
Shimadu Corp
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Publication of EP0640882A1 publication Critical patent/EP0640882A1/fr
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    • 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
    • G03G9/08742—Binders for toner particles comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08755—Polyesters

Definitions

  • the present invention relates to a toner for electrophotography. More specifically, it relates to a toner for electrophotography, which has hydrolyzability and biodegradability and permits facile deinking (removal of ink) with an existing deinking system, and which can be easily waste-treated.
  • waste paper In recent years, with a view to both environmental protection and waste treatment, i.e., the protection of forest resources and the prevention of global warming, it is actively promoted worldwide to use waste paper.
  • waster paper For promoting the use of waster paper, there are methods in which the content of a deinked pulp in reclaimed paper is increased and the process of incorporating a deinked pulp into woodfree paper and paper for information industry is developed. For this purpose, it is required to improve the quality of a deinked pulp obtained from waste paper from printed matter such as newspaper, magazines, and the like, by increasing the deinking ratio and dustproof ratio of the deinked pulp.
  • biodegradable resins for medical materials have been put to practical use to a considerable extent.
  • biodegradable materials are practically used as multifiles, sustained-releasable agrochemicals, fertilizers and gardening tools.
  • fishing lines, fishing tackle and tees for golfing are practically produced from biodegradable materials.
  • packaging materials for daily necessities such as containers are practically produced from biodegradable materials.
  • JP-A-4-179967 discloses a toner containing a specific polyester-based biodegradable binder resin.
  • this toner is with high humidity absorption properties and unstable in chargeability, and it further has a problem in that it has insufficient deinking properties due to its insolubility in an alkali solution.
  • WO 92/01245 discloses an electrostatic toner for printing having improved degradability resulting primarily from biodegradation and/or hydrolysis.
  • Polylactic acid is exemplified.
  • the resins of WO 92/01245 have -OH groups at both terminals.
  • a conventional toner for electrophotography is generally produced as follows.
  • a binder resin, a colourant, an offset preventer and other optional additives as components for the toner are mixed in advance.
  • the resultant mixture is kneaded while the binder resin is melted by heating the mixture, to obtain a mass, and the mass is pulverized to obtain a toner having a desired particle diameter.
  • the dispersibility of the additives in the binder resin is poor when the mixture is kneaded while the binder resin is melted. It is therefore required to employ very severe conditions for the melt-kneading.
  • the toner sometimes has a problem in properties for practical use such as uniform chargeability and offset prevention properties.
  • EP-A-203813 discloses a process for preparing a spherical electrophotographic toner having a desired particle size by using a reaction medium capable of dissolving a monomer but incapable of dissolving a formed polymer and carrying out polymerisation in the presence of a radical polymerisation initiator in the state where the monomer, a colourant and other additives are dissolved or dispersed in the reaction medium.
  • Xerox Disclosure Journal, Vol. 4, No. 6, Nov/Dec 1979, p.733 et seq. discloses a process for the dispersion of large amounts of carbon black in polyesters during ester exchange polymerisation by the addition of carbon black, in an amount of about 10% by weight of the polyester, to the initial monomer mixture.
  • a toner suitable for electrophotography which comprises, as a binder resin, a lactic acid-based resin of the formula (1), H-[-O-CH(CH 3 )-CO-] n -OR wherein R is alkyl, an alkali metal or an alkaline earth metal, and n is an integer of 10 to 20,000.
  • a process for the production of a toner suitable for electrophotography comprises polymerizing a monomer to form a lactic acid-based resin of the formula (1), H-[-O-CH(CH 3 )-CO-] n -OR wherein R is alkyl, an alkali metal or an alkaline earth metal, and n is an integer of 10 to 20,000, in the presence of at least one additive selected from a colourant, a charge control agent and an offset preventer.
  • a process for the production of a toner suitable for electrophotography which process comprises mixing a lactic acid-based resin of the formula (1), H-[-O-CH(CH 3 )-CO-] n -OR wherein R is alkyl, an alkali metal or an alkaline earth metal, and n is an integer of 10 to 20,000, with at least one additive selected from a colourant, a charge control agent and an offset preventer.
  • a lactic acid obtained by the lactic acid fermentation of glucose can be directly dehydratively condensed, or a cyclic dimer of lactic acid (lactide) can be subjected to ring-opening polymerization, to prepare a lactic acid-based resin, and this lactic acid-based resin can be incorporated into a toner as a binder, whereby a hydrolyzable and biodegradable toner can be prepared.
  • the so-obtained hydrolyzable and biodegradable toner can achieve the above objects.
  • the cyclic dimer of lactic acid (lactide) can be obtained by concentrating an aqueous lactic acid solution to obtain a lactic acid polycondensate and allowing the lactic acid polycondensate to react under heat (140 to 200°C) in the presence of a catalyst.
  • the reaction product can then be distilled, recrystallized and dried, and the resultant cyclic dimer of lactic acid (lactide) can be used as a monomer for the said ring-opening polymerization.
  • the ring-opening polymerization of the lactide is preferably carried out in the presence of a tin compound.
  • the lactic acid-based resin may be produced with an apparatus such as an extruder, a pressure kneader or a Banbury mixer.
  • the lactic acid-based resin is also commercially available, for example, as a product supplied by SHIMADZU CORPORATION under the trade name of "Lacty".
  • a lactic acid-based resin is easily hydrolyzable in the presence of an alkali solution, and it has an advantage in that a toner containing a colourant such as carbon black can be effectively removed from used copying paper.
  • the toner of the present invention further comprises at least one of a colourant, a charge control agent and an offset preventer.
  • the colourant is at least one of carbon black, a monoazo red pigment, a diazo yellow pigment, a quinacridone magenta pigment and an anthraquinone pigment.
  • the charge control agent is at least one of a Nigrosine dye, a quaternary ammonium salt and a monoazo metal complex dye.
  • the offset preventer is a polyolefin having a weight average molecular weight of 1,000 to 45,000. The polyolefin is required to have high dispersibility in the lactic acid monomer or dimer or the lactic acid-based resin, and it increases the fusion temperature of the toner if it has too high a melting point.
  • a polyolefin having a proper molecular weight is particularly preferably about 2,000 to 6,000.
  • the softening point of the polyolefin is preferably 100 to 180°C, particularly preferably 130 to 160°C.
  • polystyrene resin examples include polyethylene, polypropylene and polybutylene. Of these polyolefins, polypropylene is particularly preferred.
  • the offset preventer can also be at least one of fatty acid metal salts such as zinc salt, barium salt, lead salt, cobalt salt, calcium salt and magnesium salt of stearic acid, zinc salt, manganese salt, iron salt and lead salt of olefinic acid and zinc acid, cobalt salt and magnesium salt of palmitic acid; higher fatty acids such as higher fatty acids having at least 16 carbon atoms; higher alcohols such as higher alcohols having at least 16 carbon atoms, esters of polyhydric or monohydric alcohols; natural or synthetic paraffins; fatty acid esters or partial saponification products thereof; and ethylene-bisstearoylamides.
  • fatty acid metal salts such as zinc salt, barium salt, lead salt, cobalt salt, calcium salt and magnesium salt of stearic acid, zinc salt, manganese salt, iron salt and lead salt of olefinic acid and zinc acid, cobalt salt and magnesium salt of palmitic acid
  • higher fatty acids such as higher fatty acids having at least 16 carbon
  • the above offset preventers may be used alone or in combination.
  • the amount of the offset preventer per 100 parts by weight of the binder resin or the monomer to constitute the binder resin is generally 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight.
  • the binder resin of the toner of the present invention may further comprise a thermoplastic resin other than the lactic acid-based resin.
  • the "other" thermoplastic resin includes polystyrene, polyacrylic acid ester, a styrene-acrylate copolymer, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, a phenolic resin, an epoxy resin and a polyester resin.
  • the said thermoplastic resin other than the lactic acid-based resin is preferably present in the binder resin in an amount of 80 % by weight or less based on the binder resin, particularly preferably 50 % by weight or less.
  • the amount of the "other" thermoplastic resin exceeds 80 % by weight, the bonding strength thereof to a paper surface is too high, and the toner shows decreased deinking properties.
  • the toner of the present invention is used as a biodegradable toner, it is preferred not to incorporate the "other" thermoplastic resin.
  • the lactic-acid base resin used in the toner of the invention is a resin produced by polymerizing lactic acid in the presence of at least one additive selected from a colourant, a charge control agent and an offset preventer.
  • the toner for electrophotography can be obtained by a method in which the lactic acid-based resin as a binder, the colorant, the charge control agent, the offset preventer and other additive are mixed, the mixture is melt-kneaded, the kneaded mixture is cooled to solidify it and the solidified mixture is pulverized and classified.
  • the toner of the present invention can be obtained by a method in which the additives such as the colorant, the charge control agent, the offset preventer, etc., are added, as required, to the lactic acid-based resin prepared by the polymerization in the presence of at least one additive selected from the colorant, the charge control agent and the offset preventer, the mixture is melt-kneaded, the kneaded mixture is cooled to solidify it and the solidified mixture is pulverized and classified.
  • the additives such as the colorant, the charge control agent, the offset preventer, etc.
  • the latter method has an advantage in that the additives such as the colorant, the charge control agent, the offset preventer, etc., can be contained in the binder resin in a state where these additives are remarkably uniformly dispersed in the binder resin. That is because, by polymerizing the monomer which is to give the binder resin in a state where the additives are mixed with the monomer, the additives are mixed with the monomer in a liquid state before the completion of the polymerization of the monomer. That is, when the monomer itself is in a liquid state (or it may be in a solution state), the additives can be fully uniformly dispersed in the monomer. As a result, the additives are fully uniformly dispersed among molecular chains of the resin.
  • the toner When the colorant, carbon black in particular, is uniformly dispersed in the binder resin, the toner shows a decreased intrinsic volume resistance, and the toner for electrophotography exhibits stable chargeability. This is also the case with the charge control agent.
  • the offset preventer When the offset preventer is uniformly dispersed in the binder resin, there can be obtained a toner for electrophotography which has non-offset properties effective for practical use and which can be fixed with a hot roller.
  • a fluidization agent such as hydrophobic silica or colloidal silica and a magnetic powder may be incorporated into the toner for electrophotography, provided by the present invention, in order to impart the toner with fluidity.
  • These additives may be used in a state where the toner particle surfaces are covered with particles of these additives.
  • the toner for electrophotography may be mixed with a carrier comprising an iron powder, ferrite or granulated magnetite for the use of the mixture as a two-component developer. Further, when a magnetic material is incorporated into the toner, the toner can be used as a one-component developer without mixing it with any carrier.
  • L-lactide (supplied by SHIMADZU CORPORATION) 100 parts Lauryl alcohol 0.05 part Tin octylate ("Cosmos 29"® supplied by TH. GOLDSCHMIDT AG., catalyst for ring-opening polymerization) 0.2 part
  • a raw material having the above composition was fed to the raw material feeding port of a twin-screw kneading extruder.
  • the cylinder temperature was set at 190°C, and the screw rotation was set at 60 rpm in one direction.
  • a nitrogen gas was introduced through a feeding port.
  • the average residence time in the twin-screw kneading extruder was 15 minutes.
  • the resultant polymer was extruded through a nozzle having an opening diameter of 2 mm, and the extrudate was cooled to solidify it, and the solidified polymer was cut to give chips of a lactic acid-based resin.
  • the so-obtained chips had a weight average molecular weight of 100,000.
  • This resin had the formula (1) in which n was 1,400 and R was dodecyl.
  • Lactic acid-based resin obtained in Synthesis Example 1 100 parts Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts Carbon black (“MA-100”, supplied by MITSUBISHI KASEI CORPORATION) 6 parts
  • a raw material having the above composition was mixed with a super mixer and melt-kneaded under heat with a twin-screw kneader, and the kneaded mixture was pulverized with a jet mill. Then, the pulverized product was classified with a dry-method flush classifier to give negatively chargeable toner particles having an average particle diameter of 12 ⁇ m. 100 Parts of the so-obtained toner particles and 0.3 part of hydrophobic silica ("R972", supplied by Nippon Aerosil Co., Ltd.) were stirred with a Henschel mixer for 1 minute to allow the hydrophobic silica to adhere to the toner particles, whereby a toner (A) for electrophotography was obtained.
  • R972 hydrophobic silica
  • a toner (B) for electrophotography was obtained in the same manner as in Example 1 except that the amount of the lactic acid-based resin was changed to 50 parts and that 50 parts of a styrene/acrylate copolymer resin ("NC-6550" supplied by Nippon Carbide Industries Co., Inc.) was added.
  • a styrene/acrylate copolymer resin ("NC-6550" supplied by Nippon Carbide Industries Co., Inc.) was added.
  • a toner (C) for electrophotography was obtained in the same manner as in Example 1 except that the lactic acid-based resin was replaced with 100 parts of the same styrene/acrylate copolymer resin as that used in Example 2.
  • Lactic acid-based resin obtained in Synthesis Example 1 100 parts Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts Charge control agent ("Bontron S-34", supplied by Orient Chemical Industries, Co., Ltd.) 2 parts Tri-iron tetroxide (average particle diameter: 0.2 ⁇ m) 40 parts
  • a toner (D) for electrophotography was obtained from a raw material having the above composition in the same manner as in Example 1.
  • a toner (E) for electrophotography was obtained in the same manner as in Example 3 except that the lactic acid-based resin was replaced with 100 parts of the same styrene/acrylate copolymer resin as that used in Example 2.
  • L-lactide (supplied by SHIMADZU CORPORATION) 100 parts Lauryl alcohol 0.05 part Tin octylate ("Cosmos 29" supplied by TH. GOLDSCHMIDT AG., catalyst for ring-opening polymerization) 0.2 part Carbon black (“MA-100” supplied by MITSUBISHI KASEI CORPORATION) 6 parts
  • a raw material having the above composition was fed to the raw material feeding port of a twin-screw kneading extruder.
  • the cylinder temperature was set at 190°C, and the screw rotation was set at 60 rpm in one direction.
  • a nitrogen gas was introduced through a feeding port.
  • the average residence time in the twin-screw kneading extruder was 15 minutes.
  • the resultant polymer was extruded through a nozzle having an opening diameter of 2 mm, and the extrudate was cooled to solidify it, and the solidified polymer was cut to give chips of a lactic acid-based resin.
  • the so-obtained chips had a weight average molecular weight of 110,000.
  • This resin had the formula (1) in which n was 1,500 and R was dodecyl.
  • Lactic acid-based resin obtained in Synthesis Example 2 106 parts Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts
  • a raw material having the above composition was mixed with a super mixer and melt-kneaded under heat with a twin-screw kneader, and the kneaded mixture was pulverized with a jet mill. Then, the pulverized product was classified with a dry-method flush classifier to give negatively chargeable toner particles having an average particle diameter of 12 ⁇ m. 100 Parts of the so-obtained toner particles and 0.3 part of hydrophobic silica ("R972", supplied by Nippon Aerosil Co., Ltd.) were stirred with a Henschel mixer for 1 minute to allow the hydrophobic silica to adhere to the toner particles, whereby a toner (F) for electrophotography was obtained.
  • R972 hydrophobic silica
  • L-lactide (supplied by SHIMADZU CORPORATION) 100 parts Lauryl alcohol 0.05 part Tin octylate ("Cosmos 29" supplied by TH. GOLDSCHMIDT AG., catalyst for ring-opening polymerization) 0.2 part Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts
  • a raw material having the above composition was fed to the raw material feeding port of a twin-screw kneading extruder.
  • the cylinder temperature was set at 190°C, and the screw rotation was set at 60 rpm in one direction.
  • a nitrogen gas was introduced through a feeding port.
  • the average residence time in the twin-screw kneading extruder was 15 minutes.
  • the resultant polymer was extruded through a nozzle having an opening diameter of 2 mm, and the extrudate was cooled to solidify it, and the solidified polymer was cut to give chips of a lactic acid-based resin.
  • the so-obtained chips had a weight average molecular weight of 110,000.
  • This resin had the formula (1) in which n was 1,500 and R was dodecyl.
  • Lactic acid-based resin obtained in Synthesis Example 3 102 parts Carbon black ("MA-100", supplied by MITSUBISHI KASEI CORPORATION) 6 parts Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts
  • a raw material having the above composition was mixed with a super mixer and melt-kneaded under heat with a twin-screw kneader, and the kneaded mixture was pulverized with a jet mill. Then, the pulverized product was classified with a dry-method flush classifier to give negatively chargeable toner particles having an average particle diameter of 12 ⁇ m. 100 Parts of the so-obtained toner particles and 0.3 part of hydrophobic silica ("R972", supplied by Nippon Aerosil Co., Ltd.) were stirred with a Henschel mixer for 1 minute to allow the hydrophobic silica to adhere to the toner particles, whereby a toner (G) for electrophotography was obtained.
  • R972 hydrophobic silica
  • L-lactide (supplied by SHIMADZU CORPORATION) 100 parts Lauryl alcohol 0.05 part Tin octylate ("Cosmos 29" supplied by TH. GOLDSCHMIDT AG., catalyst for ring-opening polymerization) 0.2 part Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts
  • a raw material having the above composition was fed to the raw material feeding port of a twin-screw kneading extruder.
  • the cylinder temperature was set at 190°C, and the screw rotation was set at 60 rpm in one direction.
  • a nitrogen gas was introduced through a feeding port.
  • the average residence time in the twin-screw kneading extruder was 15 minutes.
  • the resultant polymer was extruded through a nozzle having an opening diameter of 2 mm, and the extrudate was cooled to solidify it, and the solidified polymer was cut to give chips of a lactic acid-based resin.
  • the so-obtained chips had a weight average molecular weight of 100,000.
  • This resin had the formula (1) in which n was 1,400 and R was dodecyl.
  • Lactic acid-based resin obtained in Synthesis Example 4 102 parts Carbon black ("MA-100", supplied by MITSUBISHI KASEI CORPORATION) 6 parts Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts
  • a raw material having the above composition was mixed with a super mixer and melt-kneaded under heat with a twin-screw kneader, and the kneaded mixture was pulverized with a jet mill. Then, the pulverized product was classified with a dry-method flush classifier to give negatively chargeable toner particles having an average particle diameter of 12 ⁇ m. 100 Parts of the so-obtained toner particles and 0.3 part of hydrophobic silica ("R972", supplied by Nippon Aerosil Co., Ltd.) were stirred with a Henschel mixer for 1 minute to allow the hydrophobic silica to adhere to the toner particles, whereby a toner (H) for electrophotography was obtained.
  • R972 hydrophobic silica
  • L-lactide (supplied by SHIMADZU CORPORATION) 100 parts Lauryl alcohol 0.05 part Tin octylate ("Cosmos 29" supplied by TH. GOLDSCHMIDT AG., catalyst for ring-opening polymerization) 0.2 part Carbon black ("MA-100", supplied by MITSUBISHI KASEI CORPORATION) 6 parts Polyolefin wax ("NP-105", supplied by MITSUI PETROCHEMICAL INDUSTRIES, LTD.) 2 parts Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts
  • a raw material having the above composition was fed to the raw material feeding port of a twin-screw kneading extruder.
  • the cylinder temperature was set at 190°C, and the screw rotation was set at 60 rpm in one direction.
  • a nitrogen gas was introduced through a feeding port.
  • the average residence time in the twin-screw kneading extruder was 15 minutes.
  • the resultant polymer was extruded through a nozzle having an opening diameter of 2 mm, and the extrudate was cooled to solidify it, and the solidified polymer was cut to give chips of a lactic acid-based resin.
  • the so-obtained chips had a weight average molecular weight of 120,000.
  • This resin had the formula (1) in which n was 1,650 and R was dodecyl.
  • a raw material composed of the lactic acid-based resin obtained in Synthesis Example 5 was mixed with a super mixer and melt-kneaded under heat with a twin-screw kneader, and the kneaded mixture was pulverized with a jet mill. Then, the pulverized product was classified with a dry-method flush classifier to give negatively chargeable toner particles having an average particle diameter of 12 ⁇ m.
  • Lactic acid-based resin obtained in Synthesis Example 1 100 parts Natural wax ("Rice Wax, supplied by Noda Wax Co., Ltd.) 2 parts Charge control agent ("NXVP 434", supplied by Hoechst) 2 parts
  • a white toner (J) having an average particle diameter of 12 ⁇ m was obtained from a raw material having the above composition in the same manner as in Example 1.
  • a white toner (K) having an average particle diameter of 12 ⁇ m was obtained in the same manner as in Comparative Example 1 except that no carbon black was used.
  • the toners for electronphotography obtained in Examples 1 to 7 and Comparative Examples 1 and 2 were used for forming test images having a black and white ratio of 6 % on surfaces of paper sheets having a weight of 75 g/m 2 to pare test sheets. Then, hand-made paper sheets were prepared from these test sheets under the following conditions.
  • Defibering An aqueous dispersion containing 5.0 % of the test sheet, 0.7 % of NaOH, 3.0 % of sodium silicate, 3.0 % of H 2 O 2 and 0.2 % of a deinking agent ("Liptol" S2800®, supplied by LION CORPORATION) was stirred in a beaker at 50°C for 20 minutes.
  • a deinking agent "Liptol" S2800®, supplied by LION CORPORATION
  • Dilution-Dehydration-Kneader treatment Water was added to the aqueous dispersion such that the aqueous dispersion had a solid content of 5 %, and the mixture was centrifugally dehydrated. Further, pulp, sodium silicate, etc., were added such that the mixture had a pulp content of 20 %, a sodium silicate content of 3.0 % and an NaOH content of 0.5 %, and these components were disaggregated with a kneader.
  • the disaggregation mixture was aged at 50°C for 2 hours.
  • Floatation Water was added to the aged product to prepare a dispersion having a pulp concentration of 1 %, and fine air bubbles were introduced into the dispersion for 7 minutes to allow the bubbles to adsorb the toner. The bubbles adsorbing the toner went upward and floated on the water surface, whereby the toner and the water were separated.
  • Preparation of hand-made sheet A hand-made sheet having a basis weight of 100 g.m 2 was prepared with a TAPPI sheet machine.
  • Table 1 shows the above test results. Each value in Table 1 shows the number of remaining toner spots. 60 - 100 ⁇ m Number More than 100 ⁇ m Number Total Number Example 1 9 6 15 Example 2 10 10 20 Example 3 9 4 13 Example 4 8 6 14 Example 5 10 5 15 Example 6 10 4 14 Example 7 8 5 13 Comparative Example 1 34 28 62 Comparative Example 2 28 25 53
  • Table 1 clearly shows that the toner for electrophotography, provided by the present invention, shows excellent deinking properties.
  • test toners (A), (B), (D), (F), (G), (H), (I) and (J) and the comparative toners (C), (E) and (K) was separately melt-molded into a film having a thickness of about 50 ⁇ m, and allowed to remain in soil for 6 months.
  • Example 1 The kneaded mixture (not pulverized) obtained in Examples 1, 2, 4 and 7 were cut to a thickness of 0.5 ⁇ m, and their cross sections were observed through an optical microscope (400 times).
  • Table 2 shows the number of dispersed carbon black particles in the field of microscopic vision. Headings in Table 2 show the diameters of the carbon black particles and numbers of carbon black particles having these diameters. Over 10 ⁇ m 10 - 5 ⁇ m Below 5 ⁇ m Example 1 7 21 Abundant Example 2 6 13 Abundant Example 4 0 4 Abundant Example 7 0 3 Abundant
  • Table 2 shows that the dispersion state of the colorant in each of Examples 1, 2, 4 and 7 had no problem in practical use, and that the dispersion states in Examples 4 and 7 were excellent.
  • Table 3 shows the image quality of the initial copy and 5,000th copy.
  • Triboelectric charge Measured with a blow-off frictional charge measuring apparatus supplied by Toshiba Chemical Co., Ltd.
  • Image density Measured with a reflection densitometer "RD-914" supplied by Macbeth.
  • Table 3 shows that the toners obtained in Examples 1, 2, 4, 5, 6 and 7 had no problem in practical use, and the toners obtained in Examples 4 and 7 gave excellent images free of background.
  • Example 3 25 Parts of the toner obtained in Example 3 was mixed with 75 parts of magnetite carrier having an average particle diameter of 60 ⁇ m to prepare a two-component developer.
  • the so-obtained developer was evaluated with a printer ("KX-P4430", supplied by Matsushita Electric Industrial Co., Ltd.) to give excellent images free of density nonuniformity or background.
  • the toner for electrophotography composed mainly of a lactic acid-based resin, provided by the present invention, reacts with water in an alkaline aqueous solution, and the resin molecules are hydrolyzed to decrease the bonding strength. Therefore, it can permit the facile deinking with an existing deinking system. As a result, the recycling of used copying paper is advantageously advanced. Further, the toner of the present invention is biodegradable, and has advantages in that a recovered toner can be disposed of without any problem and that waste paper can be disposed of without any problem.
  • R may be alkyl, suitably C 2-20 , preferably C 6-16 , more preferably C 10-14 , for example dodecyl.
  • the value of n is from 10 to 20,000, preferably from 500 to 10,000, more preferably from 800 to 5,000, most preferably from 1,000 to 2,500.
  • the toner of the invention comprises, as binder resin, a lactic acid-based resin of the formula (1) above, and may further comprise at least one of a colourant, a charge control agent or an offset preventer.
  • the toner comprises a colourant, a charge control agent and an offset preventer.

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Biological Depolymerization Polymers (AREA)

Claims (10)

  1. Toner adapté à l'électrophotographie, qui comporte, en tant que résine liante, une résine à base d'acide lactique ayant la formule (1), H-[-O-CH(CH3)-CO-]n-OR    où R est un alkyle, un métal alcalin ou un métal alcalino-terreux, et n est un nombre entier compris entre 10 et 20 000.
  2. Toner selon la revendication 1, comportant de plus au moins un élément parmi un colorant, un agent de commande de charge et un agent anti-décalage.
  3. Toner selon la revendication 2, dans lequel le colorant est au moins un élément parmi du noir de carbone, un pigment rouge monoazo, un pigment jaune diazo, un pigment magenta de quinacridone et un pigment d'anthraquinone.
  4. Toner selon la revendication 2 ou 3, dans lequel l'agent de commande charge est au moins un élément parmi une teinture de Nigrosine, un sel d'ammonium quaternaire et une teinture avec complexes métallifères monoazo.
  5. Toner selon l'une quelconque des revendications 2 à 4, dans lequel l'agent anti-décalage est une polyoléfine ayant un poids moléculaire moyen compris entre 1 000 à 45 000.
  6. Toner selon l'une quelconque des revendications 2 à 4, dans lequel l'agent anti-décalage est au moins un élément parmi des sels métalliques d'acide gras, des acides gras supérieurs, des alcools supérieurs, des esters d'alcools polyvalents ou monovalents, des paraffines naturelles ou synthétiques, des esters d'acide gras ou des produits de saponification partielle de ceux-ci et des éthylène-distéaroylamides.
  7. Toner selon l'une quelconque des revendications précédentes, dans lequel la résine liante comporte de plus une résine thermoplastique autre que la résine à base d'acide lactique selon une quantité de 80 % en poids ou moins sur la base de la résine liante.
  8. Toner selon l'une quelconque des revendications précédentes, dans lequel la résine à base d'acide lactique est une résine produite par polymérisation d'acide lactique en présence d'au moins un additif sélectionné parmi un colorant, un agent de commande de charge et un agent anti-décalage.
  9. Procédé de production d'un toner adapté à l'électrophotographie, ledit procédé consistant à polymériser un monomère pour former une résine à base d'acide lactique ayant la formule (1), H-[-O-CH(CH3)-CO-]n-OR    où R est un alkyle, un métal alcalin ou un métal alcalino-terreux, et n est un nombre entier compris entre 10 et 20 000, en présence d'au moins un additif sélectionné parmi un colorant, un agent de commande de charge et un agent anti-décalage.
  10. Procédé de production d'un toner adapté à l'électrophotographie, ledit procédé consistant à mélanger une résine à base d'acide lactique ayant la formule (1), H-[-O-CH(CH3)-CO-]n-OR    où R est un alkyle, un métal alcalin ou un métal alcalino-terreux, et n est un nombre entier compris entre 10 et 20 000, avec au moins un additif sélectionné parmi un colorant, un agent de commande de charge et un agent anti-décalage.
EP19940306341 1993-08-30 1994-08-30 Révélateur pour électrophotographie et procédé pour sa fabrication Expired - Lifetime EP0640882B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP235939/93 1993-08-30
JP23593993 1993-08-30
JP6200250A JP2909873B2 (ja) 1993-08-30 1994-08-02 電子写真用トナーおよびその製造方法
JP200250/94 1994-08-02

Publications (2)

Publication Number Publication Date
EP0640882A1 EP0640882A1 (fr) 1995-03-01
EP0640882B1 true EP0640882B1 (fr) 1999-02-10

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EP19940306341 Expired - Lifetime EP0640882B1 (fr) 1993-08-30 1994-08-30 Révélateur pour électrophotographie et procédé pour sa fabrication

Country Status (3)

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EP (1) EP0640882B1 (fr)
JP (1) JP2909873B2 (fr)
DE (1) DE69416470T2 (fr)

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JP3785011B2 (ja) * 1999-12-10 2006-06-14 株式会社巴川製紙所 電子写真用トナー
US7045321B2 (en) 2001-03-01 2006-05-16 Canon Kabushiki Kaisha Polyhydroxyalkanoate containing unit with phenylsulfanyl structure in the side chain, process for its production, charge control agent, toner binder and toner which contain novel polyhydroxyalkanoate, and image-forming method and image-forming apparatus which make use of the toner
JP3496002B2 (ja) 2001-04-27 2004-02-09 キヤノン株式会社 新規なポリヒドロキシアルカノエートを含有するバインダー樹脂、該バインダー樹脂を含むトナー；該トナーを用いた画像形成方法および画像形成装置
KR100528749B1 (ko) 2001-04-27 2005-11-15 캐논 가부시끼가이샤 곁사슬에 페닐설파닐구조 및/또는 페닐 설포닐구조를 지닌신규의 폴리하이드록시알카노에이트와, 그 생산방법,신규의 폴리하이드록시알카노에이트를 함유하는하전제어제, 토너바인더 및 토너, 그리고 상기 토너를이용하는 화상형성방법 및 화상형성장치
KR100461511B1 (ko) 2001-04-27 2004-12-14 캐논 가부시끼가이샤 신규 폴리히드록시알카노에이트, 그 제조방법, 이폴리히드록시알카노에이트를 함유하는 전하제어제,토너바인더 및 토너, 및 화상형성방법 및 이 토너를사용하는 화상형성장치
KR100487555B1 (ko) 2001-04-27 2005-05-06 캐논 가부시끼가이샤 신규의 폴리하이드록시알카노에이트 및 그 제조방법, 상기폴리하이드록시알카노에이트를 함유하는 하전제어제,토너바인더 및 토너, 그리고 상기 토너를 사용한화상형성방법 및 화상형성장치
JP3501771B2 (ja) 2001-04-27 2004-03-02 キヤノン株式会社 ポリヒドロキシアルカノエートを含有するバインダー樹脂、該バインダー樹脂を含むトナー；該トナーを用いた画像形成方法および画像形成装置
JP3689697B2 (ja) 2002-02-15 2005-08-31 キヤノン株式会社 アミド基及びスルホン酸基を有する新規なポリヒドロキシアルカノエート及びその製造方法、新規なポリヒドロキシアルカノエートを含有する荷電制御剤、トナーバインダーならびにトナー及び該トナーを用いた画像形成方法および画像形成装置
JP3779221B2 (ja) * 2002-02-22 2006-05-24 株式会社巴川製紙所 電子写真用トナー
JP3639831B2 (ja) 2002-02-28 2005-04-20 キヤノン株式会社 新規なポリヒドロキシアルカノエート及びその製造方法、それを含有する荷電制御剤、トナーバインダーならびにトナー及び該トナーを用いた画像形成方法および画像形成装置
JP3880567B2 (ja) 2002-10-24 2007-02-14 キヤノン株式会社 新規なポリヒドロキシアルカノエート共重合体
JP4027297B2 (ja) 2002-10-24 2007-12-26 キヤノン株式会社 新規なポリヒドロキシアルカノエート及びその製造方法；それを含む樹脂組成物；新規なポリヒドロキシアルカノエートを含有する荷電制御剤、静電荷像現像トナー及びバインダー樹脂組成物
JP3647432B2 (ja) 2002-10-24 2005-05-11 キヤノン株式会社 シクロヘキシル構造を側鎖に有するユニットを含む新規なポリヒドロキシアルカノエート及びその製造方法、該ポリヒドロキシアルカノエートを含有するバインダー樹脂
US7144666B2 (en) * 2003-02-24 2006-12-05 Samsung Electronics Co., Ltd. Toner used with electrophotography
JP4343672B2 (ja) 2003-04-07 2009-10-14 キヤノン株式会社 フルカラー画像形成用カラートナー
JP5093834B2 (ja) * 2006-01-27 2012-12-12 旭化成ケミカルズ株式会社 生分解性樹脂粉体及びその製造方法
US8137884B2 (en) * 2007-12-14 2012-03-20 Xerox Corporation Toner compositions and processes
JP5473252B2 (ja) 2008-06-02 2014-04-16 株式会社リコー トナー、現像剤、及び画像形成方法
BRPI0913942A2 (pt) 2008-07-01 2015-10-20 Ricoh Co Ltd toner para formação de imagem, aparelho para formação de imagem, método para formação de imagem e cartucho de processo
JP5298716B2 (ja) * 2008-09-10 2013-09-25 富士ゼロックス株式会社 静電荷像現像用トナー、静電荷像現像剤、トナーカートリッジ、プロセスカートリッジ及び画像形成装置
US8383307B2 (en) 2008-10-23 2013-02-26 Ricoh Company, Limited Toner, developer, and image forming method and apparatus using the toner
JP2010175691A (ja) 2009-01-28 2010-08-12 Fuji Xerox Co Ltd 画像形成装置及び印刷物
JP5855808B2 (ja) 2009-02-26 2016-02-09 株式会社リコー 静電潜像現像用トナー
JP5397756B2 (ja) 2009-06-30 2014-01-22 株式会社リコー 静電荷像現像用トナー
JP5560985B2 (ja) 2009-08-03 2014-07-30 株式会社リコー トナー、並びに現像剤、画像形成方法及び画像形成装置
JP5246098B2 (ja) * 2009-08-20 2013-07-24 カシオ電子工業株式会社 電子写真式画像形成装置の二成分現像剤
JP4997271B2 (ja) * 2009-08-31 2012-08-08 シャープ株式会社 トナーおよびその製造方法
JP5765132B2 (ja) 2010-12-06 2015-08-19 株式会社リコー 静電荷像現像用トナーと該トナーを用いる現像剤、及び画像形成装置、並びにプロセスカートリッジ
CN102998923B (zh) 2011-09-13 2014-12-10 株式会社理光 调色剂、显影剂以及图像形成装置
CN103930830B (zh) 2011-09-13 2017-06-23 株式会社理光 电子照相调色剂、包含该调色剂的显影剂和图像形成装置
US8735040B2 (en) 2011-12-28 2014-05-27 Ricoh Company, Ltd. Toner, developer, and image forming apparatus
JP5929267B2 (ja) 2012-02-03 2016-06-01 株式会社リコー トナー、現像剤、画像形成装置及びブロック共重合体
JP5957988B2 (ja) 2012-03-14 2016-07-27 株式会社リコー 静電荷像現像用トナー、現像剤、現像剤収容容器、画像形成方法、プロセスカートリッジ
JP2013195486A (ja) 2012-03-16 2013-09-30 Ricoh Co Ltd トナー及び現像剤
WO2022202135A1 (fr) 2021-03-24 2022-09-29 Ricoh Company, Ltd. Particules de résine, toner, procédé de production de particules de résine, procédé de production de toner, révélateur, unité de stockage de toner et appareil de formation d'image

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EP0203818B1 (fr) * 1985-05-30 1992-05-20 Mita Industrial Co. Ltd. Toner électrophotographique
JPH06502926A (ja) * 1990-07-13 1994-03-31 イー・アイ・デユポン・ドウ・ヌムール・アンド・カンパニー 分解性樹脂を含有する静電気乾式トナー

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7629099B2 (en) 2005-07-15 2009-12-08 Ricoh Company Limited Toner, developer, image forming method, and toner container

Also Published As

Publication number Publication date
DE69416470T2 (de) 1999-06-24
DE69416470D1 (de) 1999-03-25
EP0640882A1 (fr) 1995-03-01
JP2909873B2 (ja) 1999-06-23
JPH07120975A (ja) 1995-05-12

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