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
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08726—Polymers of unsaturated acids or derivatives thereof
• • 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
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08704—Polyalkenes
• • 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
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08726—Polymers of unsaturated acids or derivatives thereof
  • G03G9/08733—Polymers of unsaturated polycarboxylic acids
• • 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

• This invention relates to a releasing composition suitable for electrophotographic toner (hereinafter referred to as toner). More particularly, it relates to a releasing composition for toner, particularly suitable for that used in copy machines or printers of heat fixation type.
• Toners in heat fixation methods, are fixed on a substrate with a heated roller.
• MF minimum temperature for fixing
• HO hot offset temperature
• a releasing agent such as low molecular weight polypropylene during the preparation of toners to attain an elevated HO.
• TF toner flowability
• a releasing composition suitable for electrophotographic toner which comprises
• Suitable polypropylenes include propylene homopolymers, and copolymers of propylene with up to 25% (preferably up to 20%, more preferably up to 10%) of one or more other monomers copolymerizable therewith, for example, ethylene, and olefines containing 4 ⁇ 8 or more carbon atoms (such as butene and octene). (In the above and hereinafter, % represents % by weight, unless otherwise specified.) Copolymers containing less than 75% propylene units may result in lower HO.
• Melt viscosity at 160°C of said polypropylene resin (A) is usually 10 ⁇ 3,000 cps (centipoises), preferably 15 ⁇ 2,000 cps. Polypropylenes of melt viscosity higher than 3,000 cps result in poor hot offset effects when used in toners. In case of melt viscosity lower than 10 cps, frowability of tonners becomes poor. Melt viscosity at 160°C is measured with a Brookfield rotational viscometer, under conditions in accordance with JIS-K1557-1970, except the measuring temperature. Temperature of the sample to be measured can be adjusted with an oil bath equipped with a temperature regulator.
• thermally degraded products of high molecular weight polypropylene resins preferred are thermally degraded products of high molecular weight polypropylene resins.
• Thermal degradation can be accomplished, for example, by passing a high molecular weight polypropylene resin through a reaction vessel, such as a tubular reactor, capable of applying heat homogeneously, at a temperature of 300 ⁇ 450°C during 0.5 ⁇ 10 hours.
• the melt viscosity of thermally degaraded products can be controlled by the degradation temperature and the degradation period. When the temperature is less than 300°C, longer period of time is required to attain low melt viscosity; while it is difficult to control the melt viscosity on account of too rapid degradation at the temperature exceeding 450°C.
• Suitable low molecular weight polypropylenes (a1), constituting said modified polypropylene (B1) in this invention include the same ones as the above-mentioned, which may be the same or different as (A) except that (a1) having a melt viscosity at 160°C higher than that of (A).
• Preferable ratio of the melt viscosity of at 160°C of said polypropylene (a1) to the melt viscosity at 160°C of said (A) is not more than 500/1, more preferably not more than 50/1, particularly not more than 5/1, and at least 1.1/1.
• melt viscosity at 160°C of said polypropylene (a1) is usually higher than 10 cps and not more than 5,000 cps, preferably 15 ⁇ 3,000 cps. When the melt viscosity is higher than 5,000 cps, hot offset of toners become poor.
• Suitable polypropylenes (a1) include, for example, thermally degraded polypropylenes, unmodified or modified with one or more monomers other than acidic monomers; and oxydates of these modified or unmodified, thermally degraded polypropylenes.
• Suitable thermally degraded polypropylenes include ones obtainable by thermal degradation of high molecular weight polypropylene resins, usually having a melt index of 0.1 ⁇ 150 g/10min. or more, preferably 1 ⁇ 100 g/10min., as measured in accordance with JIS K6758.
• Such high molecular weight polypropylene resins are inclusive of propylene homopolymers, and copolymers of propylene with one or more other monomers copolymerizable therewith, for example, ethylene, and olefins containing 4 ⁇ 8 or more carbon atoms (such as butene and octene); as well as propylene (co)polymers modified with one or more monomers other than acidic monomers.
• Suitable monomers usable for modification of polypropylenes, before or after thermal degradation, include styrenic monomers, such as styrene, ⁇ - methylstyrene, p-methylstyrene and p-methoxystyrene; esters [such as alkyl (C1 ⁇ 18) esters] of ethylenically unsaturated carboxylic acids [such as (meth)acrylic, maleic and itaconic acids], for instance, methyl, ethyl and butyl (meth)acrylates, and mono- or di-methyl, ethyl and butyl maleates; ethylenically unsaturated nitriles, such as (meth)acrylonitriles; ethylenically unsaturated organo silane compounds and ethylenically unsaturated organo fluorine compounds, as mentioned in US Patent No.5,238,767; and mixtures of two or more of these monomers
• Modification may be carried out in the presence or absence of peroxide catalyst.
• Oxidates of these modified or unmodified thermally degraded polypropylenes can be produced by partially oxidizing such polypropylenes with oxygen or oxygen-containing gas (air), or with ozone-containing oxygen or ozone-containing gas (air).
• the resulting oxydates have an acid value of usually at most 80, preferably at most 50.
• the content of propylene units of these polypropylene (a1) is generally at least 75%, preferably at least 80%, more preferably at least 90%. Copolymers containing less than 75% propylene units may results in toners of lower HO.
• polypropylenes (a1) preferred are thermally degraded polypropylenes.
• Suitable acidic monomers (b1), for modification of said polypropylene (a1) include ethylenically unsaturated carboxylic acids and/or anhydrides thereof, for example, (meth)acrylic acids (acrylic acid and/or methacrylic acid; similar expressions are used hereinafter), maleic acid, fumaric acid and itaconic acid; anhydrides, such as maleic, itaconic, citraconic, allylsuccinic and nadic anhydrides; and mixtures of two or more of them.
• (meth)acrylic acids acrylic acid and/or methacrylic acid
• maleic acid and fumaric acid and itaconic acid anhydrides, such as maleic, itaconic, citraconic, allylsuccinic and nadic anhydrides
• preferred are (meth)acrylic acids, maleic acid and anhydride thereof, particularly maleic acid and anhydride thereof.
• the content of acidic monomer (b1), constituting said modified polypropylene (B1), is generally 0.1 ⁇ 50%, preferably 0.2 ⁇ 40%, more preferably 0.5 ⁇ 30%, based on the weight of (a1).
• Use of (b1) larger than 50% results in too hygroscopic modified polypropylene, which may make image concentration unstable when used in toners.
• (b1) is less than 0.1%, sufficient effects of improving TF are not attained.
• Modified polypropylenes (B1) can be produced by carrying out grafting or addition reaction of one or more monomers comprising said acidic monomer (b1) onto said polypropylene (a1) in the presense of or in the absense of peroxide catalyst.
• (b1) there may be used up to 30%, preferably up to 20% [based on the weight of (a1)] of one or more other monomers, as mentioned above [such as styreic monomers, alkyl (meth)acrylates, alkyl maleates; unsaturated nitriles, unsaturated organo silane and unsaturated organo fluorine compounds].
• monomers such as styreic monomers, alkyl (meth)acrylates, alkyl maleates; unsaturated nitriles, unsaturated organo silane and unsaturated organo fluorine compounds.
• Modification is generally carried out within an atmosphere of inert gas, such as nitrogen.
• the reaction may be carried out at a temperature of usually between the melting point of polyolefin and 300 °C , preferably 140 ⁇ 250°C , for 1 ⁇ 20 hours.
• Suitable peroxide catalysts include, for example, benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, t-butylperoxybenzoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, and the like.
• Modified polypropylene (B1) usually has an acid number of 0.5 ⁇ 100, preferably 1 ⁇ 40, more preferably 1 ⁇ 20. Products having an acid number less than 0.5 provide toners of poor TF, while ones having an acid number higher than 100 may lower HO of toners.
• Modified polypropylene (B1) generally has a number-average molecular weight (hereinafter referred to as Mn ⁇ ) of usually 1,000 ⁇ 20,000, preferably 1,500 ⁇ 10,000, more preferably 2,000 ⁇ 8,000.
• Low molecular weight polyethylenes (a2) constituting said modified polyethylene (B2) in this invention, are low molecular weight polyethylenes having a melt viscosity of 10 ⁇ 8,000 cps, preferably 15 ⁇ 5,000 cps at 140°C, including low density ones, intermediate density ones and high density ones.
• Suitable low molecular weight polyethylenes (a2) include, for example, polyethylenes obtainable by oligomerization; thermally degraded polyethylenes, unmodified or modified with one or more monomers other than acidic monomers; and oxydates of these modified or unmodified, thermally degraded polyethylenes.
• Suitable thermally degraded polyethylenes include ones obtainable by thermal degradation of high molecular weight polyethylene resins, usually having a melt flow rate (MFR) of 0.1 ⁇ 300 or more, preferably 1 ⁇ 250, as measured in accordance with JIS K6760 (at 190 °C and 2.16kgf load).
• MFR melt flow rate
• Such high molecular weight polyethylene resins are inclusive of ethylene homopolymers, and copolymers of ethylene with one or more other monomers copolymerizable therewith, for example, olefins containing 3 ⁇ 12 or more carbon atoms (such as propylene, 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene and 1-dodecene); as well as ethylene (co)polymers modified with one or more monomers other than acidic monomers.
• olefins containing 3 ⁇ 12 or more carbon atoms such as propylene, 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene and 1-dodecene
• Suitable monomers usable for modification of polyethylenes before or after thermal degradation, include the same ones as mentioned above [such as styrenic monomers, alkyl (meth)acrylates, alkyl maleates, unsaturated nitriles, unsaturated organo silanes and unsaturated organo fluorine compounds].
• Thermal degradation of polyethylene resins can be accomplished in the same manner as that of polypropylene resins described in the (A), except that the temperature may be 250 ⁇ 450°C. Modification and oxidation (production of oxidates) may be carried out in the same manner as polypropylenes.
• the content of ethylene units of these polyethylenes is generally at least 75%, preferably at least 80%, more preferably at least 90%. Copolymers containing less than 75% ethylene units may results in toners of lower HO.
• Low molecular weight polyethylenes (a2) such as thermally degraded ones, generally have a Mn ⁇ of 800 ⁇ 20,000, preferably 1,000 ⁇ 10,000, as measured by GPC (gel permeation chromatography). Sufficient TF improving effects are not attained, when Mn ⁇ is less than 800. Polyethylenes having Mn ⁇ higher than 20,000 have a tendency to reduce HO.
• Softening point of (a2) is usually 70 ⁇ 200°C preferably 90 ⁇ 180°C, which can be measured according to ring and ball method of JIS K2207. Sufficient improvement in TF is not attained, when softening point is less than 70°C. MF improving effects become insufficient in case of softening point exceeding 200°C.
• Melt viscosity of (a2) is usually 10 ⁇ 8,000 cps, preferably 15 ⁇ 5,000 cps at 140°C. Flowability of toners becomes poor with lower melt viscosity than 10 cps. In case it exceeds 8,000 cps, there is a tendency of reducing HO.
• low molecular weight polyethylenes (a1) preferred are thermally degraded polyethylenes.
• Suitable thermally degraded polyethylenes include ones containing usually 1 ⁇ 10, preferably 2 ⁇ 7 terminal double bonds per 1,000 carbon atoms. Ones containing less than 1 terminal double bond per 1,000 carbon atoms cannot be reacted with sufficient amount of acidic monomer and provide toners of poor TF.
• Suitable acidic monomers (b2), for modification of said polyethylene (a2) include the same ones as the above-mentioned acidic monomers (b1).
• preferred are (meth)acrylic acids, maleic acid and anhydride thereof, particularly maleic acid and anhydride thereof.
• the content of acidic monomer (b2), constituting said modified polyethylene (B2), is generally 0.1 ⁇ 50%, preferably 0.2 ⁇ 40%, more preferably 0.5 ⁇ 30%, based on the weight of (a2).
• Use of (b2) larger than 50% results in too hygroscopic modified polyethylene, which may make image concentration unstable when used in toners.
• (b2) is less than 0.1%, sufficient effects of improving TF are not attained.
• Modified polyethylenes (B2) can be produced by carrying out grafting or addition reaction of one or more monomers comprising said acidic monomer (b2) onto said polyethylene (a2) in the presense of or in the absense of peroxide catalyst, in the same manner as modified polypropylene (B1). Similarly, up to 30% of one or more other monomers may be used in addition to (b2).
• Modified polyethylene (B2) usually has an acid number of 0.5 ⁇ 100, preferably 1 ⁇ 50, more preferably 1 ⁇ 20. Products having an acid number less than 0.5 provide toners of poor TF, while ones having an acid number higher than 100 may lower HO of toners.
• Modified polyethylene (B2) generally has a Mn ⁇ of usually 1,000 ⁇ 20,000, preferably 1,500 ⁇ 10,000, more preferably 2,000 ⁇ 8,000. Products having Mn ⁇ less than 1,000 provide toners of poor TF, while ones having Mn ⁇ higher than 10,000 may lower HO of toners.
• compositions of the present invention comprising a low molecular weight polypropylene (A) and a modified polyolefin (B) [(B1) and/or (B2)]
• the content of (A) is generally 60 ⁇ 99.5%, preferably 70 ⁇ 99%, more preferably 80 ⁇ 98%
• the content of (B) is usually 0.5 ⁇ 40%, preferably 1 ⁇ 30%, more preferably 2 ⁇ 20%.
• Use of (B) less than 0.5% results in poor TF improving effects of toners, while (B) exceeding 60% may cause reduction of HO.
• Suitable binders include thermoplastic resins, for example, polyester resins, styrenic and/or acrylic resin, epoxy resins, poloyurethane resins, and the like.
• Suitable polyesters include, for example, polycondensation products of a polycarboxylic acid component with a polyol component, and ring-opening polymers of a lactone.
• suitable polyols include aliphatic diols, such as ethylene glycol, 1,2- and 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol and diethylene glycol, and alcoholates (such as sodium alcoholate) of these diols; cycloaliphatic diols, such as cyclohexylene glycol, cyclohexane dimethanol and hydrogenated bisphenol A; aromatic diols, such as bisphenols (such as bisphenol A, bisphenol S and bisphenol F) and hydroquinone, and esters and alcoholates of these phenols (such as diacetylbisphenol A and bisphenol A disodium alcoholate); aliphatic polyols containing 3
• AO adducts of aromatic diols preferred are AO adducts of aromatic diols, aliphatic diols and combinations of them, particularly AO adducts of aromatic diols (especially PO adducts of bisphenol A).
• suitable polycarboxylic acid components are C2 ⁇ C30 aliphatic dicarboxylic acids, such as malonic, succinic, adipic, sebacic and dodecane dicarboxylic acids, and esters and halides of these acids, such as dimethyl adipate and adipic dichloride; aromatic dicarboxylic acids, such as terephthalic, isophthalic, phthalic and naphthalene dicarboxylic acids, esters and halides of these acids, such as dimethyl terephthalate and terephthalic dichloride; and tribasic or higher carboxylic acids, such as trimellitic acid.
• polyesters of terephthalic acid with PO adducts of bisphenol A are preferred.
• Suitable styrenic and/or acrylic resins include, for example, (co)polymers of one or more styrenic monomers [such as styrene; and styrene homologues or substituted styrenes, including alkyl(C1 ⁇ C8)styrenes (such as ⁇ - methyl-styrene, o-, m- and p-methylstyrenes, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-t-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, aryl-substituted styrenes (such as p-pheny
• monomers (1) preferred is styrene.
• monomers (2) preferred are alkyl (meth)acrylates and (meth)acrylic acids, particularly methyl, ethyl, butyl and 2-ethylhexyl (meth)acrylates.
• monomers (3) preferred are vinyl esters and aliphatic hydrocarbon monomers, particularly vinyl acetate and butadiene.
• monomers (4) preferred are divinyl benzene and 1,6-hexanediol diacrylate.
• styrenic and/or acrylic resins the contents of these monomers (1), (2), (3) and (4) can be varied widely, but the usual ranges are as follows : [(1)+(2)] 70 ⁇ 100 %, preferably 80 ⁇ 100 %; (3) 0 ⁇ 30%, preferably 0 ⁇ 20%; and (4) 0 ⁇ 0.1 mole %, preferably at 0 ⁇ 0.05 mole %, based on the total monomers.
• Styrenic and/or acrylic resins may be produced using any known polymerization techniques, such as solution, suspension, bulk and emulsion polymerizations, and combinations of them (such as solution polymerization followed by suspension or bulk polymerization, or suspension polymerization followed by solution or bulk polymerization).
• Polymerization can be carried out in the presence of one or more polymerization initiators, for example, azo compounds, such as azobis-iso-butyronitrile, azobis-iso-valeronitrile, and the like; peroxides, such as those mentioned above for modification; and so on.
• the amount of polymerization initiators can vary widely, but is generally 0.02 ⁇ 1.0 %, preferably 0.03 ⁇ 0.8 %, based on the total weight of the monomers.
• Polymerization is generally carried out within an atmosphere of inert gas, such as nitrogen atom, at a temperature of usually 50 ⁇ 250°C, preferably 70 ⁇ 230°C.
• Reaction period which may be varied with other conditions, is usually 1 ⁇ 50 hours, preferably 2 ⁇ 15 hours.
• Suitable epoxy resins and polyurethanes are inclusive of those written in US Patent No.5,238,767.
• binder resins preferred are styrenic resins [particularly styrene/(meth)acrylic copolymers] and especially polyester resins.
• binder resins may vary widely; but preferred are those having a Mn ⁇ of about 2,000 ⁇ about 50,000 or higher, preferably about 3,000 ⁇ about 30,000.
• Weight-average molecular weight (hereinafter referred to as Mw ⁇ ) of binder resins is usually about 100,000 ⁇ about 2,000,000, preferably about 150,000 -about 1,500,000. When Mw ⁇ is less than 100,000, it is difficult to obtain sufficient HO; and Mw ⁇ higher than 2,000,000 results in too high MF.
• Molecular weight distribution [represented by the ratio of Mw ⁇ / Mn ⁇ ] of binder resins is generally at least about 20, preferably at least about 30. Mw ⁇ / Mn ⁇ less than 20 results in poor balance of HO and MF.
• Glass transition temperature (Tg) of binder resins is generally about 40 ⁇ about 80°C, preferably about 45 ⁇ about 70°C. Resins of Tg less than 40°C provides toner of poor shelf stability; and when Tg is higher than 80°C, MF becomes too high to be used practically as toners.
• Resin composition for electrophotographic toner comprises (I) a releasing composition, comprising a low molecular weight polypropylene (A) and a modified polyolefin (B) [(B1) and/or (B2)], and (II) a binder resin.
• the amount of the releasing composition (I) [(A)+(B)] is generally 0.5 ⁇ 10%, preferably 1 ⁇ 5%, based on the total weight of (I) and (II), for final use as toners.
• the components (A), (B) and (II) can be added at any oder.
• (A) and (B) may blended beforehand, or added separately to (II).
• Binder resin may be added beforehand to the releasing composition to obtain a resin composition for toners, or may be added together with the releasing composition during preparation of toners to obtain toners.
• the releasing composition can be mixed with the binder resin by any known methods.
• the releasing composition may be added during polymerization (preparation of binder resin), or may be blended with the binder resin after polymerization, using a mixer. It is preferred that the releasing composition is homogeneously distributed in the resin composition, to obtain excellent release effects.
• Resin compositions of the invention may contain optionally one or more of colorants and various additives to form toners.
• Suitable colorants and other additives include inorganic and organic pigments, such as carbon black, iron black, benzidine yellow, quinacridone pigments, rhodamine B, phthalocyanine pigments and the like; carrier particles, for example, magnetic powders, such as powders of ferromagnetic metals and compounds (such as iron, cobalt, nickel, magnetite, hematite, ferrite and the like), glass beads and the like; charge controllers, such as nigrosine, quaternary ammonium salts and metal complex es; lubricants (such as polytetrafluoroethylene, fatty acids and metal salts or amides thereof), plasticisers, hydrophobic colloidal silica powders, antioxidants (such as hindered phenols, sulphur compounds and phosphorus compounds, written in US Patent No.5,238,767), and so on.
• carrier particles for example, magnetic powders, such as powders of ferromagnetic metals and compounds (such as iron,
• electrophotographic toners the contents of these components can be varied widely. In general, the ranges may be approximately as follows:
• Said toner can be optionally mixed with one or more carrier particles, such as iron powder, glass beads, nickel powder and ferrite, and used as a developer for electrical latent images.
• carrier particles such as iron powder, glass beads, nickel powder and ferrite
• hydrophobic colloidal silica powder may be used to improve TF.
• Said toner can be fixed on substrates (such as paper, polyester film and the like) to be used as recording materials.
• Fixation may be accomplished by any known fixation means, for example, heat roll fixation of copy mashines, such as heat-fixation type copyers or printers.
• Mn ⁇ and Mw ⁇ of polyolefins and modified polyolefins were measured with GPC under following conditions :
• Binder resins used in the following examples are as follows:
• the product after cooling was removed into a vessel equipped with a thermometer and a stirrer, and volatile matters (such as xylene and unreacted maleic anhydride) were removed under reduced pressure not more than 5 mmHg at 180°C for 2 hours to obtain a modified polyethylene (B2-2) having an acid number of 28, Mn ⁇ of 3,100 and a melt viscosity of 3,800 cps at 140°C .
• volatile matters such as xylene and unreacted maleic anhydride
• Example Comparative Example 1 2 3 4 5 6 7 8 1 2 3 4 (A) (A-1) 480 480 425 - 440 440 375 - 150 140 500 - (A-2) - - - 480 - - - 440 - - - - (B1-1) 20 - 75 20 - - - - - - - (B) (B1-2) - 20 - - - - - - - - 350 - - - (B2-1) - - - - 60 - 125 60 - - - 500 (B2-2) - - - - - - - 60 - - - 360 - - Releaser No. R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12
• Binder (i) Into a vessel equipped with a thermometer and a stirrer, 450 parts of Binder (i) and 50 parts of Releaser R1 were charged, and heated under stirring to 190°C for 2 hours to prepare a resin composition (C-1).
• toners for electrophotpgraphy and an electrophosographic developers were produced and evaluated as follows :
• the ingredients was powder dryblended, and kneaded with a laboplast mill at 140°C at 30 rpm for 10 minutes, followed by finely pulverizing the kneaded mixture with a jet mill (PJM100, produced by Nippon Pneumatic Mfg.Co.,Ltd.) and then classifying with a dispersion separator (MSD, produced by Nippon Pneumatic Mfg.Co.,Ltd.) to cut fine powders of less than 2 microns diameter.
• a colloidal silica powder (Aerosil R972, produced by Japan Aerosil Co.) were added and homogeneously mixed to obtain a toner.
• Releasing compositions comprising (A) and (B), according to the present invention, can provide toners having improved anti-hot offset properties without reducing flowability. Besides, the releasing compositions can prevent effectively toner adhesion (filming) towards carrier to attain toners having low tendency of filming towards carrier. In addition, improved low temperature fixability can be attained.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8217759

Family Applications (1)

Country Status (1)

Cited By (1)

Citations (6)

• 1994
  • 1994-07-04 EP EP94304892A patent/EP0691580A1/fr not_active Withdrawn

Patent Citations (6)

Non-Patent Citations (5)

Similar Documents

Legal Events