EP0322456A1 - Toner pour electrophotographie - Google Patents

Toner pour electrophotographie Download PDF

Info

Publication number
EP0322456A1
EP0322456A1 EP87906452A EP87906452A EP0322456A1 EP 0322456 A1 EP0322456 A1 EP 0322456A1 EP 87906452 A EP87906452 A EP 87906452A EP 87906452 A EP87906452 A EP 87906452A EP 0322456 A1 EP0322456 A1 EP 0322456A1
Authority
EP
European Patent Office
Prior art keywords
toner
polymer
molecular weight
styrene
acid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP87906452A
Other languages
German (de)
English (en)
Other versions
EP0322456A4 (fr
Inventor
Masaaki Shin
Nobuhiro Hirayama
Keiichi Ishikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Toatsu Chemicals Inc
Original Assignee
Mitsui Toatsu Chemicals Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsui Toatsu Chemicals Inc filed Critical Mitsui Toatsu Chemicals Inc
Publication of EP0322456A1 publication Critical patent/EP0322456A1/fr
Publication of EP0322456A4 publication Critical patent/EP0322456A4/fr
Withdrawn legal-status Critical Current

Links

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
    • G03G9/083—Magnetic toner particles
    • 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
    • G03G9/08784—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775
    • G03G9/08795—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
    • 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

Definitions

  • the present invention relates to an electro­photographic toner powder for use in the development of an electrostatic image in electrophotography, and more particularly relates to an electrophotographic toner which exerts excellent lower temperature fixing ability in a hot-roll copying method.
  • the electrophotographic dry toner is conven­tionally composed of a resin composition, coloring agent which contains pigments or dyestuffs, charge control agent, wax and the like. Synthetic or natural resin is used for the resin composition singly or as a suitable mixture.
  • a relatively high molecular weight styrene containing polymer is generally used in admixture with a relatively low molecular weight styrene containing polymer in a suitable proportion.
  • the composition and thermal properties of the styrene containing polymer employed are important factors deciding the toner characteristics, and currently their improvement is strongly required.
  • the resin which is free from the blocking phenomenon and moreover has a low softening temperature can be prepared by similary reducing molecular weight of the low molecular weight styrene containing polymer which constitutes the resin.
  • a polymerization initiator is uneconomically required in a relatively large amount in order to obtain such low molecular weight styrene containing polymer.
  • a large amount of relatively high-polar impurities such as residue of the polymerization initiator is supposed to contaminate in the toner.
  • frictional charge of the toner is extremely labilized and it becomes difficult to obtain sharp, clear and good quality images over a long period.
  • the low molecular weight styrene containing polymer can also be obtained by using a small amount of polymerization initiator in combination with a chain transfer agent such as mercaptan.
  • the toner containing a low molecular weight polypropylene Japanese Patent Publication No. 3,304/1977
  • Japanese Patent Publication No. 6,895/1980 Japanese Patent Publication No. 6,895/1980
  • These toners can improve offset resistance to some extent, but cannot improve fixing ability.
  • the toner added with plasticizers such as phthalic acid esters etc. (Japanese Patent Publication (12,679/1971) is known.
  • plasticizers such as phthalic acid esters etc.
  • Japanese Patent Publication (12,679/1971) Japanese Patent Publication (12,679/1971) is known.
  • the added plasticizers migrate with the passage of time, deteriorate stability and cause problems in actual use.
  • toner containing the resin composed of a vinyl polymer or its mixture which has at least one peak value respectively in the molecular weight regions of 103 - 8 x 104- and 105 - 2 x 106 Japanese Patent Laid-open No. 16,144/1981, relevant to U.S.P. 4,499,168
  • Japanese Patent Laid-open No. 16,144/1981 relevant to U.S.P. 4,499,168
  • the toner containing a low molecular weight polymer which has a number average molecular weight of 3,000 - 50,000 and Mw/Mn of less than 3.5, and a polymer which is insoluble and infusible Japanese Patent Publication No. 86558/­1983
  • the toner obtained from such polymer is still unsatisfactory in charge stability, cannot provide a good image under high relative humidity in particular and leads to serious problems in actual use.
  • the toner is apt to cause blocking in high relative humidity, and is difficult to employ in practical application.
  • the object of this invention is to provide an electrophotographic toner which is excellent in the fixing ability at a high duplication speed and low temperature, capable of obtaining a sharp, clean and good image, and also outstanding in the resistance against blocking and offset.
  • the aforesaid object of this invention can be achieved by providing an electrophotographic toner containing a vinyl polymer as a primary component.
  • the vinyl polymer has 1,000 - 5,000 in a number average molecular weight (Mn) and 1 - 3 in a ratio (Mw/Mn) of a weight average molecular weight (Mw) to the number average molecular weight.
  • the toner of this invention is excellent as a one component toner containing magnetic powder or a two component toner employed after mixing with a carrier.
  • the toner is also excellent in the fixing ability at the high duplication speed and under low heat supply, outstanding in the blocking resistance and always capable of providing stable and good quality images. Therefore, the toner is suitable for the electrophotographic duplication operating, for example, at a high speed of 40 - 100 sheets/min. and a lower temperature of 130 - 140°C.
  • the vinyl monomer having carboxyl groups which is used in this invention includes, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, cinnamic acid, maleic anhydride, fumaric acid, maleic acid and their methyl, ethyl and 2-ethylhexyl monoesters. These monomers are used singly or a combination of two and more. In consideration of hygroscopic property of the polymer, methacrylic acid, maleic anhydride and cinnamic acid are particularly preferable.
  • the ratio of vinyl monomer to styrene is determined so as to obtain an acid value in the range of preferably 0 - 50 KOHmg/g, and more preferably 0 - 30 KOHmg/g.
  • the acid value exceeding 50 KOHmg/g is undesirable because the hygroscopic property increases and charge stability is eliminated.
  • the vinyl polymer used in this invention can be prepared by any of conventionally known methods such as solution polymerization, suspension polymer­ization, emulsion polymerization, bulk polymerization.
  • the solution polymerization is preferred in consider­ation of quality stabilization.
  • the polymerization initiator or the chain transfer agent is frequently used in a large amount particularly in the case of preparing the low molecular weight polymer.
  • solvent is always distilled off at high temperatures and under high vacuum in the final step of preparation.
  • the residue of polymer­ization initiator, unreacted monomer and low boiling fractions are simultaneously removed in this step to obtain a high quality polymer containing very small amount of impurities. Therefore the toner obtained from the polymer has a good humidity resistance and an excellent stability of quality even in the copying test for many days, for example, for the duplication of 50,000 sheets of paper.
  • the polymerization initiator for use in this invention is at least one of known radical polymeriza­tion initiator which belongs to perester, hydroperoxide, dialkyl peroxide, ketone peroxide, diacyl peroxide, percarbonate, azobis derivative.
  • the initiator includes, for example, t-butyl peroctoate, t-butyl perbenzoate, t-butyl perisobutyrate, t-butyl hydro­peroxide, cumene hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, lauryl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, 2,2′-­azobisisobutyronitrile, 2-phenylazo-2,4-dimethyl-4-­methoxyvaleronitrile, and 2,2′-azobis(2-methylpropane).
  • dialkyl peroxide polymerization initiators such as di-t-butyl peroxide, t-butyl cumyl peroxide and di-cumyl peroxide are particularly preferred for use among these initiators.
  • the initiator is used in an amount of 0.05 - 15.0 parts by weight per 100 parts by weight of the vinyl monomer.
  • the solvent which is used in this invention is a compound having sufficient solubility for the vinyl monomer and its polymer.
  • the solvent includes, for example, aliphatic hydrocarbons, aromatic hydro­carbons, esters, ethers, ketones, alcohols, cellosolves, carbitols, formamides and sulfamides. These known solvent can be used singly or in combination.
  • Particularly preferable solvent for this invention is xylene, ethylbenzene, benzene, toluene, ethyl acetate and SolvessoTM #100 and #150 (products of Esso Petroleum Co.).
  • the vinyl polymer which is used in this invention is obtained by polymerizing the aforesaid vinyl monomer and preferably contains styrene as the major ingredient.
  • the number average molecular weight of the polymer is required to be 1,000 - 5,000 and preferred to be 1,500 - 2,800.
  • Mw/Mn is required to be 1 - 3.
  • the number average molecular weight of less than 1,000 is undesirable because the toner decreases the blocking resistance. That of more than 5,000 or also Mw/Mn of more than 3 deteriorate the fixing ability and render the toner useless.
  • copolymer of styrene with acrylic acid ester such as butyl acrylate which is conventionally used for the toner resin lowers Tg to less than 50°C, causes blocking and renders the toner useless.
  • vinyl polymer of this invention derived from styrene alone or styrene and vinyl monomer containing carboxyl group can maintain Tg at not lower than 50°C and satisfy both fixing ability and blocking resistance.
  • Tg of the vinyl polymer is preferably 50 - 75°C in this invention. Tg of not higher than 50°C is undesirable because of blocking generation, while Tg exceeding 75°C causes lack of fixing ability.
  • the vinyl polymer of this invention is used as an ingredient of the electrophotographic toner in combination with below described other polymers.
  • the amount is normally 30 - 80% by weight, preferably 35 - 70% by weight of the resin in the toner.
  • the aforesaid resin is ground to a size of about 0.5 - 2 mm and mixed with carbon black.
  • the resulting mixture is optionally added with other polymer such as acrylic resin, coloring agent, magnetic powder, a small amount of charge control agent and wax.
  • the mixture thus obtained is subjected to dispersion mixing with a Henshel mixer and then to melt kneading at a temperature of 130 - 180°C with a kneader.
  • the resulting mass is crushed to coarse particles, and successively ground and classified in air to obtain particles having a size of 5 - 25 ⁇ m.
  • the above-mentioned toner contains the resin normally in an amount of 10 - 99% by weight and more generally contains 40% by weight of the magnetic powder and 60% by weight of the resin. In the absence of magnetic powder, the toner contains 50 - 99% by weight of the resin and more generally contains, for example, 5 - 10% by weight of carbon black and 95 - 90% by weight of the resin.
  • polymers which may be used in the preparation of aforesaid electrophotographic toner include, for example, acrylic resin, styrene-acrylic resin, styrene-butadien resin, styrene-maleic acid resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin and cellulosic resin.
  • high molecular weight polymer having Mw of not less than 100,000 is preferred in particular.
  • the toner deteriorates the fixing ability when the content of aforementioned polymers other than the vinyl polymer is less than 30% by weight.
  • the toner cannot maintain its strength and deteriorates apparent fixing ability when the content exceeds 80%.
  • the use of crosslinked polymers which are insoluble and infusible is undesirable because of fixing ability deterioration.
  • the coloring agent employed is pigments and dyestuffs, and includes, for example, carbon black, aniline blue, alcoyl blue, chrome yellow, ultramarine blue, quinoline yellow, methylene blue, phthalocyanine blue, malachite green, rose bengal and magnetite.
  • the charge control agent which may be used includes, for example, nigrosine, triphenylmethane dyestuffs, chrome complex of 3,5-di-t-butylsalicylic acid.
  • conventionally known additives such as colloidal silica, zinc stearate, low molecular weight polypropylene, polyethylene wax, polytetra­fluoroethylene etc. may also be added if required.
  • Mw and Mn are determined by separating in accordance with gel permeation chromatography (hereinafter abbreviated as GPC) using tetrahydrofuran (THF) as solvent, detecting with a differential refractometer (SHODEX SE-RII) and calculating on the basis of the analytical curve of standard polystyrene.
  • GPC gel permeation chromatography
  • SHODEX SE-RII differential refractometer
  • Developing agents were prepared by mixing each 3 parts of these toners with 100 parts of ferrite carrier (F-95-100, a product of Japan Iron Powder Co.)
  • the minimum fixation temperature was defined as the lowest temperature at which no transfer of the toner was found on the cellophane tape at all. The temperature was further raised to check the temperature at which offset phenomenon was initiated.
  • Example 2 The same procedures as in Example 1 were carried out to obtain the polymer except 970 parts of styrene and 30 parts of methacrylic acid were used in place of 1,000 parts of styrene and the amount of AIBN was changed to 80 parts.
  • the resulting polymer had Mn of 2,600, Mw/Mn of 2.0, Tg of 69°C and an acid value of 19 KOHmg/g.
  • the toner was prepared and evaluated by the same procedures as in Example 1. As a result, the minimum fixation temperature was 145°C and the offset initiation temperature was 240°C. No blocking was found at all.
  • the polymer was obtained by carrying out the same procedure as in Example 2 except n-butyl acrylate was used in place of methacrylic acid.
  • the polymer obtained had Mn of 2,500, Mw/Mn of 1.9 and Tg of 46°C.
  • the toner was prepared and evaluated by the same procedures as in Example 1.
  • the toner had a minimum fixation temperature of 145°C and an offset initiation temperature of 240°C. The toner, however, was perfectly coagulated after the blocking test at 50°C for a week.
  • Example 1 the polymer was obtained by the same procedures as in Example 1 except the first half of the mixture composed of xylene, styrene and AIBN was fed over 2 hours and the other half of the mixture was fed over 8 hours.
  • the resulting polymer had Mn of 1900, Mw/Mn of 4.2 and Tg of 48°C.
  • the toner was prepared and evaluated by the same procedures as in Example 1.
  • the toner had a minimum fixation temperature of 145°C and an offset initiation temperature of 240°C.
  • the toner was almost coagulated after the blocking test at 50°C for a week and could not be applied for actual use.

Abstract

Toner pour électrophotographie contenant en tant que composant principal un polymère vinylique présentant un poids moléculaire moyen (Mn) compris entre 1000 et 5000, et un rapport entre le poids moléculaire à moyenne pondérale Mw et le poids moléculaire moyen Mn compris entre 1 et 3. Ce toner présente d'excellentes caractéristiques de fixage, etc., à haute vitesse ou à basse température.
EP19870906452 1987-07-10 1987-09-30 Toner pour electrophotographie. Withdrawn EP0322456A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP62171089A JPS6415753A (en) 1987-07-10 1987-07-10 Electrophotographic dry toner
JP171089/87 1987-07-10

Publications (2)

Publication Number Publication Date
EP0322456A1 true EP0322456A1 (fr) 1989-07-05
EP0322456A4 EP0322456A4 (fr) 1990-02-05

Family

ID=15916790

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870906452 Withdrawn EP0322456A4 (fr) 1987-07-10 1987-09-30 Toner pour electrophotographie.

Country Status (4)

Country Link
EP (1) EP0322456A4 (fr)
JP (1) JPS6415753A (fr)
KR (1) KR890702087A (fr)
WO (1) WO1989000719A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0462280A1 (fr) * 1989-12-12 1991-12-27 MITSUI TOATSU CHEMICALS, Inc. Toner electrophotographique
EP0540278A1 (fr) * 1991-10-30 1993-05-05 Toda Kogyo Corp. Particules magnétiques pour révélateurs magnétiques
EP0662641A1 (fr) * 1993-12-24 1995-07-12 Mitsui Toatsu Chemicals, Incorporated Composition de résine pour toner électrophotographique

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2757927B2 (ja) * 1990-06-28 1998-05-25 インターナショナル・ビジネス・マシーンズ・コーポレイション 半導体基板上の隔置されたシリコン領域の相互接続方法
NL9200931A (nl) * 1992-05-26 1993-12-16 Hendrik Veenstra Verpakking voor het opbergen en etaleren van een aantal doosvormige voorwerpen, meer in het bijzonder informatiedragers zoals floppy discs en dergelijke.

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5683749A (en) * 1979-12-12 1981-07-08 Canon Inc Pressure-fixable toner
JPS56113143A (en) * 1980-02-13 1981-09-05 Konishiroku Photo Ind Co Ltd Electrostatic image developing toner and its manufacture
JPS59188657A (ja) * 1983-04-11 1984-10-26 Canon Inc 圧力定着性トナ−

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No further relevant documents have been disclosed. *
See also references of WO8900719A1 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0462280A1 (fr) * 1989-12-12 1991-12-27 MITSUI TOATSU CHEMICALS, Inc. Toner electrophotographique
EP0462280A4 (en) * 1989-12-12 1992-05-20 Mitsui Toatsu Chemicals Inc. Electrophotographic toner composition
EP0540278A1 (fr) * 1991-10-30 1993-05-05 Toda Kogyo Corp. Particules magnétiques pour révélateurs magnétiques
US5328793A (en) * 1991-10-30 1994-07-12 Toda Kogyo Corporation Magnetic particles for magnetic toner
EP0662641A1 (fr) * 1993-12-24 1995-07-12 Mitsui Toatsu Chemicals, Incorporated Composition de résine pour toner électrophotographique
US5468585A (en) * 1993-12-24 1995-11-21 Mitsui Toatsu Chemicals, Incorporated Resin composition for use in an electrophotographic toner

Also Published As

Publication number Publication date
KR890702087A (ko) 1989-12-22
WO1989000719A1 (fr) 1989-01-26
EP0322456A4 (fr) 1990-02-05
JPS6415753A (en) 1989-01-19

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