(b) (Compound 1) R14 R15
R10 Ro R 16 5 H3C 1-nC \-CH: CH R11 NEN ( ) R17 CH R2 OH HO R18 ( ) NEN wherein Ro-Rs independently denote a hydrogen atom, a halogen atom or an alkyl group with the proviso that at least 15 OH HO one of Ro-Rs is an alkyl group; and (Compound 2) CH (c) M R21 R20 R26 R27 Hey,
R-( )---( )—i. 25 OH HO (Compound 3) R24 OH HO R30 HCVCH, Y C YCH, wherein Rio-Rao independently denote a hydrogen atom, a C halogen atom or an alkyl group with the proviso that at least V one of Rio-Rao is an alkyl group. W CH A monoaZO compound having an alkyl group Substituent HC-C3 ? ( ) as mentioned is preferred in order to provide a toner having HC a high chargeability and capable of forming images having 35 NEN a high image density and faithfully reproducing latent images. AS far as the monoaZO compound has at least one alkyl OH HO group in its molecular structure, the position of the alkyl 40 (Compound 4) group Substituent is not particularly restricted. In the case of HC CH the compound of the formula (b), however, it is preferred V / that an alkyl group is present at a position of at least one of V -CH2 CH3 groupS R-Rs, particularly Rs. So as to provide the toner 1. with a stable chargeability. 45 V It is preferred that the monoazo compound has an alkyl group of 4-12 carbon atoms, particularly 6-10 carbon atoms, because of a good mutual Solubility with the toner binder resin So as to provide a toner having a high and Stable NEN ( ) chargeability and capable of high-density images and high- 50 definition imageS faithfully reproducing latent imageS. It is further preferred that the alkyl group has 4-12 carbon atoms including a tertiary carbon, more preferably 6-10 carbon (Compound 5) atoms including a tertiary carbon. A most preferred alkyl 55 HC CH group is represented by -C(CH-)-CH-C(CH). V / 3 It is further preferred that the monoaZo compound has HiQ Y Sch, Such a structure including a pair of units Sandwiching the azo -CH2 bond and including one unit containing a Substituent of Such CH Y-h an alkyl group and the other unit containing a Substituent of 60 / 3 ( ) 3 a halogen atom, preferably a chlorine atom. C.H. Among the monoaZO compounds of the above formulae HC (a)-(c), the monoazo compound of the formula (b) is par- NEN ( ) ticularly preferred., Specific examples of the monoaZO compound preferably 65 used in the present invention may include Compounds 1 to OH HO 37 shown below: US 6,426,169 B1
-continued -continued (Compound 6) (Compound 12) H3C H3C CH3 y/ 5 HCV -CH,1n CH3 NENo
'VCH 3 OH HO H3C 1O (Compound 13) HC Cl
NFN NEN
OH HO 15 OH HO (Compound 7) CH 3 (Compound 14) CH5 2O CH HC CHs NEN HC NEN
OH HO 25 (Compound 8) OH HO (Compound 15) HC CH
3O CH215 C NEN HC
NEN OH HO (Compound 9) 35 OH HO HCV /CH H3C 1CN (Compound 16) V -CH2 CH CH i. H3C-N C/ CH 40 YOH,
Cl
NEN 45 NEN
OH HO OH HO (Compound 10) (Compound 17) CH 50 / HC y H. HC-C SS HC H. CH NEN 55 Hics/ /NCH, CH2 OH HO H3CN (Compound 11) SN CH CH / 60 HC-C C C / HC NEN NEN
65 OH HO OH HO US 6,426,169 B1
-continued -continued (Compound 18) CH (Compound 23) 3 H3C-N /CoH19 SN 5 CH Cl
C NEN
1O OH HO (Compound 24) OH HO H3CN /CH7 15 h HC (Compound 19) H3C-N A H3CN /CH7 CH SN CH
C
25 OH HO OH HO (Compound 25) (Compound 20) 30 C CH3-N /C5H11 CN CH
C 35 OH HO in-C4H9 (Compound 26) n-C2H5
KOH HO C2H5
NE (Compound 21) C7H15 H3CN / 45 SN OH HO CH (Compound 27) n-C12H25 C
OH HO CH5 (Compound 22) 55 HO C2H5 (Compound 28) n-C10H11
65 OH HO
US 6,426,169 B1 13 14 The azo iron compound may preferably be added to the Herein, “a peak in a molecular weight region of 3x10 to toner in 0.1-10 wt. parts, more preferably in 0.5-5 wt. parts, 5x10" means that a peaktop is in the molecular weight per 100 wt. parts of the binder resin. region on the GPC chromatogram, and “a shoulder in a The azo iron compound can be used in combination with molecular weight region of above 5x10" and at most 10" a charge control agent known to be used in a toner. Examples means that the GPC chromatogram shows an inflection of Such known charge control agents may include: other point, i.e., a point giving a maximum of the differential of organometallic complexes, metal Salts and chelate com the curve, in the molecular weight region. pounds; more Specifically, acetylacetone metal complexes, The toner showing the above-mentioned molecular hydroxycarboxylic acid metal complexes, polycarboxylic weight distribution characteristic shows a good balance and acid metal complexes, polyol metal complexes, and further Storability, and also good uniform chargeability and con carboxylic acid derivatives, Such as metal Salts, anhydrides tinuous image forming performance. and esters of carboxylic acids, condensates of aromatic AS a result of the combination of the molecular weight compounds, and phenol derivative Such as bisphenols and distribution of the toner and the azo iron compound, advan calixarenes. tageous effects as described below can be attained. That is, The azo iron compound used in the present invention is a 15 the azo iron compound used in the present invention has an reaction product of iron and a monoaZo compound and alkyl group So that the compound can be uniformly dis formed by coordination of a monoaZO compound onto an persed in the toner and has a function of plascitizing the iron atom. The azo iron compound may assume a form of an binder resin, particularly a low-molecular weight component iron complex, an iron complex Salt or a mixture of these, thereof contributing to the fixability, thus improving the e.g., azo iron compounds of the above-mentioned formulae fixability. Further, as the high-molecular weight component (d), (e) and (f), or a mixture of these. of the binder resin can be simultaneously plasticized to Some In the present invention, owing to the reaction of the extent, the mutual solubility of the low-molecular weight monoaZo compound having an alkyl group with iron, the compound and the high-molecular weight component is resultant aZO iron compound becomes Stabler thermally and improved So that the high-molecular weight component is with time than azo compounds of other metals and imparts 25 uniformly dispersed in the toner, whereby the toner can a good and Stable chargeability to the toner. exhibit an enhanced release effect from the fixing member at The azo iron compound may be obtained by reacting Such the time of fixation. a monoaZO compound capable of bonding with an iron atom Further, the toner according to the present invention with an iron Source compound in an aqueous and/or organic contains the low-molecular weight component and the high Solvent, preferably in an organic Solvent. molecular weight component in a good balance, So that it has The reaction product formed in the organic Solvent may an appropriate degree of hardneSS and is rich in Slippability. be dispersed in an appropriate amount of water, and the AS a result, while the azo iron compound used in the present precipitate is filtered out, washed with water and dried to invention shows a high chargeability-imparting function and obtain an azo iron compound. Example of the organic provides a toner which shows a high attachability and is Solvent as the reaction medium may include: water-miscible 35 liable to cause toner melt-Sticking onto Surrounding organic Solvents, alcohols, ethers or glycols, Such as members, particularly the photosensitive member, the toner methanol, ethanol, ethylene glycol monomethyl ether, eth of the present invention is rich in Slippability So the toner ylene glycol monoethyl ether, propylene glycol monomethyl attachment onto the photoSensitive member can be Sup ether, ethylene glycol dimethyl ether (monoglyme), dieth pressed even in a high temperature/high humidity environ ylene glycol dimethyl ether (diglyme), ethylene glycol 40 ment where the toner attachment is liable to occur. diethyl ether, triethylene glycol dimethyl ether (triglyme), If a component giving the peak or shoulder in the molecu tetraethylene glycol dimethyl ether (tetraglyme), ethylene lar weight region of above 5x10' and at most 107 is not glycol and propylene glycol, non-protonic polar Solvents, present in the THF-soluble content, the resultant toner is such as N,N-dimethylformamide, N,N-dimethylacetamide, caused to have inferior anti-high-temperature offset charac N-methyl-2-pyrrolidone, and dimethyl Sulfoxide. Among 45 teristic. Further, the dispersibility of the azo iron compound the above organic Solvents, ethylene glycol monomethyl therein and the slippability of the toner is liable to be ether (methyl celloSolve), ethylene glycol monoethyl ether insufficient to provide a toner showing an inferior develop (ethyl celloSolve) and ethylene glycol are particularly pre ing performance and liable to cause toner Sticking. ferred in order to provide a crystalline azo iron compound. The molecular weight distribution of THF-soluble con It is also preferred to re-crystalline a once-formed azo iron 50 tents of toners or binder resins described herein are based on compound from an organic Solvent as described above. GPC measurement performed according to the following The amount of the organic Solvent is not particularly C. restricted but may be used in an amount of 2 to 5 times the monoaZo compound as the ligand by weight. In the GPC apparatus, a column is Stabilized in a heat Suitable examples of the iron-Source compound may 55 chamber at 40°C., tetrahydrofuran (THF) solvent is caused include: ferric chloride, ferric Sulfate and ferric nitride. The to flow through the column at that temperature at a rate of iron-Source compound may be used in /3 to 2 equivalent, 1 ml/min., and about 100 ul of a GPC sample solution is preferably /2 to 2/3 equivalent of Fe atom with respect to 1 injected. The identification of Sample molecular weight and mol of the monoaZo compound as the liquid. its molecular weight distribution is performed based on a The toner contains a THF-soluble component having such 60 calibration curve obtained by using Several monodisperse a molecular weight distribution as to provide a GPC chro polystyrene Samples and having a logarithmic Scale of matogram showing at least one peak in a molecular weight molecular weight verSuS count number. region of 3x10 to 3x10", more preferably 3x10 to 2.5x10'. The Standard polystyrene Samples for preparation of a Further, it shows at least one peak or shoulder in a molecular calibration curve may be those having molecular weights in weight region of above 5x10" and at most 10", preferably 65 the range of about 10° to 10 available from, e.g., Toso K.K. 10 to 107, more preferably 10 to 5x10, further preferably or Showa Denko K.K. It is appropriate to use at least 10 10 to 1.5x10°. Standard polystyrene Samples, e.g., a combination of F-850, US 6,426,169 B1 15 16 F-80, F-4, A-2500, F-450, F-40, F-2, A-1000, F-288, F-20, The acid value of a toner or a binder resin described F-1, A-500, F-128, F-10, and A-5000, available from Toso herein are based on values measured in the following K.K. The detector may be an RI (refractive index) detector. C. For accurate measurement, it is appropriate to constitute the column as a combination of Several commercially available The basic operation is according to JIS K-070. polystyrene gel columns. A preferred example thereof may 1) A toner Sample is preliminarily treated for removal of be a combination of Shodex KF-801, 802, 803, 804, 805, additives other than the binder resin (polymer component) or 806, 807 and 800P. measurement of acid values and contents of components The GPC sample may be prepared as follows. other than the binder resin. A toner or a binder resin is A toner or binder resin sample is placed in THF and left pulverized, and 0.5-2.0 g of the pulverized Sample is accu Standing for Several hours. Then, the mixture is Sufficiently rately weighed to provide a sample containing W (g) of Shaken until a lump of the resinous Sample disappears and polymer component. then further left standing for more than 12 hours at room 2) The sample is placed in a 300-ml beaker, and 150 ml temperature. In this instance, a total time of from the mixing of a toluene/ethanol (4/1) mixture liquid is added thereto to of the sample with THF to the completion of the standing in 15 dissolve the Sample. THF is taken for at least 24 hours. Thereafter, the mixture is 3) The sample solution is (automatically) titrated with a caused to pass through a Sample treating filter having a pore 0.1 mol/liter-KOH solution in ethanol by means of a poten size of 0.2-0.5 um (e.g., “Maishoridisk H-25-5”, available tiometric titration apparatus (e.g., “AT-400 (win from Toso K.K.) to recover the filtrate as a GPC sample. The workstation)” with an “ABP-410 electromotive buret, Sample concentration is adjusted to provide a resin concen available from Kyoto Denshi K.K.). tration of e.g., 0.1 mg/ml. 4) The amount of the KOH solution used for the titration Examples of the binder resin constituting the toner of the is recorded at S (ml), and the amount of the KOH solution present invention may include: Styrene resins, Styrene used for a blank titration is measured and recorded at B (ml). copolymer resins, polyester resins, polyol resins, polyvinyl 5) The acid value is calculated according to the following chloride resin, phenolic resin, natural resin-modified phe 25 equation: nolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, Silicone-resin, polyurethane resin, polyamide resin, furan resin, epoxy wherein f denotes a factor of the 0.1 mol/liter-KOH solution. resin, epoxy resin, Xylene resin, polyvinyl butyral, terpene Examples of monomers for adjusting the acid value of the resin, coumarone-indene resin, and petroleum resin. binder resin may include: acrylic acids and C- and B-alkyl Examples of comonomers for constituting the Styrene derivatives, Such as acrylic acid, methacrylic acid, and copolymers as a preferred class of binder resin together with O-ethylacrylic acid; other unsaturated monocarboxylic Styrene monomer may include: Styrene derivatives, Such as acids, Such as crotonic acid, cinnamic acid, Vinylacetic acid, Vinyltoluene, acrylic acid; acrylate esters, Such as methyl isocrotonic acid, and angelic acid; and unsaturated dicar acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, 35 boxylic acids, Such as fumaric acid, maleic acid, citraconic octyl acrylate, 2-ethylhexyl acrylate and phenyl acrylate; acid, alkenylsuccinic acid, itaconic acid, mesaconic acid, methacrylic acid; methacrylate esters, Such as methyl dimethylmaleic acid, and dimethylfumaric acid, and their methacrylate, ethyl methacrylate, butyl methacrylate, and monoester derivatives and anhydrides. These monomers octyl methacrylate; maleic acid; dicarboxylic acid esters may be used Singly or in mixture of two or more Species for having a double bond, Such as butyl maleate, methyl 40 copolymerization with another monomer to obtain a desired maleate, and dimethyl maleate; acrylamide, acrylonitrile, binder resin. Among these, monoester derivatives of unsat methacrylonitrile, butadiene; Vinylesters, Such as Vinyl urated dicarboxylic acids are particularly preferred for the chloride, Vinyl acetate and Vinyl benzoate, olefins, Such as acid value control. ethylene, propylene and butylene; and vinylketones, Such as The monoester derivatives of unsaturated dicarboxylic vinyl methyl ketone and vinyl hexyl ketone. These vinyl 45 acids may include: monoesters of C, B-unsaturated dicar monomers may be used Singly or in combination of two or boxylic acids, Such as monomethyl maleate, monoethyl more Species. maleate, monoalkyl maleate, monophenyl maleate, monom The binder resin used in the present invention may ethyl fumarate, monoethyl fumarate, monobutyl fumarate preferably have an acid value of 1-100 mgKOH/g, more and monophenyl fumarate; and monoesters of alkenyldicar preferably 1-70 mgKOH/g, further preferably 1-50 50 boxylic acids, Such as monobutyl n-butenylsucciniate, mgKOH/g, particularly preferably 2-40 mgKOH/g. In case mono methyl n- octe nyl Succinate, mono ethyl where the acid value of the binder resin is below the n-butenylmalonate, monomethyl n-dodecenylglutarate, and above-described range, it is possible that good developing monobutyl n-butenyladipate. performance and Stable developing performance over a long Such a carboxyl group-containing monomer may be period owing to the interaction between the binder resin and 55 added in 0.1-50 wt. parts, preferably 0.1-30 wt. parts, the azo iron compound are not sufficiently exhibited. On the further preferably 0.2-15 wt. parts per 100 wt. parts of the other hand, in case where the binder resin has an excessively total monomers for constituting the binder resin. large acid value, the binder resin is liable to be hygroscopic, The above-mentioned monoester of dicarboxylic acid is thus resulting in a lower image density and increased fog. preferred because it is an ester which has a low Solubility in More specifically, by using a binder resin having an acid 60 aqueous dispersion medium and a high Solubility in an value, the chargeability-imparting performance of the azo organic Solvent or another monomer. iron compound is enhanced to realize a toner having a quick The toner binder resin may preferably have a glass Start-up chargeability and a high chargeability. transition temperature (Tg) of 45–80 C., preferably 50–70 These effects sufficiently exhibited when the acid value C., in view of the storability of the resultant toner. In case of measured based on the toner is 0.5-100 mgKOH/g, more 65 a Tg below the above-mentioned range, the resultant toner is preferably 0.5-50 mgkOH/g, particularly preferably 1.0-40 liable to be degraded in a high temperature environment and mgKOH/g. cause offsetting at the time of fixation. If the Tg is higher US 6,426,169 B1 17 18 than the above range, the resultant toner is liable to exhibit butyl per o Xy a Zelate, 2,2-bis(4,4-di-t- an inferior fixability. butylp eroxy cyclohexyl)- propane, and The binder resin for constituting the toner of the present t-butylperoxyallylcarbonate. invention may be produced through a polymerization These polyfunctional polymerization initiators may pref process, Such as Solution polymerization, emulsion polymer erably be used in combination with a monofunctional poly ization and Suspension polymerization. merization initiator, more preferably with a monofunctional In the emulsion polymerization process, a monomer polymerization initiator having a 10 hour-halflife tempera almost insoluble in water is dispersed as minute particles in ture (a temperature providing a halflife of 10 hours by an aqueous phase with the aid of an emulsifier and is decomposition thereof) which is lower than that of the polymerized by using a water-Soluble polymerization initia polyfunctional polymerization initiator, So as to provide a tor. According to this method, the control of the reaction toner binder resin Satisfying various requirements in com temperature is easy, and the termination reaction Velocity is bination. Small because the polymerization phase (an oil phase of the Examples of the monofunctional polymerization initiator vinyl monomer possibly containing a polymer therein) con may include: organic peroxides, Such as benzoyl peroxide, Stitutes a separate phase from the aqueous phase. As a result, 15 dicumyl peroxide, t-butylperoxycumene and di-t-butyl per the polymerization Velocity becomes large and a polymer oxide; and a Za and diaZo compounds, Such as having a high polymerization degree can be prepared easily. aZobisisobutyronitrile, and diazoaminoaZobenzene. Further, the polymerization proceSS is relatively simple, the The monofunctional polymerization initiator can be polymerization product is obtained in fine particles, and added to the monomer simultaneously with the above additives Such as a colorant, a charge control agent and mentioned polyfunctional polymerization initiator but may others can be blended easily for toner production. Therefore, preferably be added after lapse of a polymerization time this method can be advantageously used for production of a which exceeds the halflife of the polyfunctional polymer toner binder resin. ization initiator, in order to appropriately retain the initiator In the emulsion polymerization, however, the emulsifier efficiency of the polyfunctional polymerization initiator. added is liable to be incorporated as an impurity in the 25 The above-mentioned polymerization initiators may pref polymer produced, and it is necessary to effect a post erably be used in an amount of 0.01-10 wt. parts, particu treatment Such as Salt-precipitation in order to recover the larly 0.05-2 wt. parts per 100 wt. parts of the monomer in product polymer at a high purity. The Suspension polymer view of the efficiency. ization is more convenient in this respect. It is also preferred that the binder resin has been The Suspension polymerization may preferably be per crosslinked with a crosslinking monomer as enumerated formed by using at most 100 wt. parts, preferably 10-90 wt. hereinbelow. parts, of a monomer (mixture) per 100 wt. parts of water or The crosslinking monomer may principally be a monomer an aqueous medium. The dispersing agent may include having two or more polymerizable double bonds. Specific polyvinyl alcohol, partially Saponified form of polyvinyl examples thereof may include: aromatic divinyl compounds, alcohol, and calcium phosphate, and may preferably be used 35 Such as divinylbenzene and divinylnaphthalene; diacrylate in an amount of 0.05-1 wt. part per 100 wt. parts of the compounds connected with an alkyl chain, Such as ethylene aqueous medium. The polymerization temperature may Suit glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4- ably be in the range of 50–95 C. and selected depending on butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6- the polymerization initiator used and the objective polymer. hexanediol diacrylate, and neopentylglycol diacrylate, and The binder resin may preferably be produced in the 40 compounds obtained by Substituting methacrylate groups for presence of a polyfunctional polymerization initiator and/or the acrylate groups in the above compounds, diacrylate a monofunctional polymerization initiator, as enumerated compounds connected with an alkyl chain including an ether hereinbelow. bond, Such as diethylene glycol diacrylate, triethylene glycol Specific examples of the polyfunctional polymerization diacrylate, tetraethylene glycol diacrylate, polyethylene gly initiator may include: polyfunctional polymerization initia 45 col #400 diacrylate, polyethylene glycol #600 diacrylate, tors having at least two functional groups having a dipropylene glycol diacrylate and compounds obtained by polymerization-initiating function, Such as peroxide groups, Substituting methacrylate groups for the acrylate groups in per molecule, inclusive of 1,1-di-t-butylperoxy-3,3,5- the above compounds, diacrylate compounds connected trimethyl-cyclohexane, 1,3-bis-(t-butylperoxyisopropyl) with a chain including an aromatic group and an ether bond, benzene, 2,5-dimethyl-2,5-(t-butylperoxy) hexane, 2,5- 50 Such as polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl) dimethyl-2,5-di-(t-butylperoxy) he xine-3, tris(t- propane diacrylate, polyoxyethylene (4)-2,2-bis(4- butylperoxy)triazine, 1,1-di-t-butylperoxycyclohexane, 2.2 hydroxyphenyl)propanediacrylate, and compounds obtained -di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid by Substituting methacrylate groups for the acrylate groups n-butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t- in the above compounds, and polyester-type diacrylate butylperoxyaZelate, di-t-butylperoxytrimethyladipate, 2,2- 55 compounds, such as one known by a trade name of MANDA bis-(4,4-di-t-butylperoxycyclohexyl)propane, 2,2-t- (available from Nihon Kayaku K.K.). Polyfunctional butylperoxyoctane and various polymer oxides, and crosslinking agents, Such as pentaerythritol triacrylate, tri polyfunctional polymerization initiators having both a methylethane triacrylate, tetramethylolmethane tetracrylate, polymerization-initiating functional group, Such as peroxide oligoester acrylate, and compounds obtained by Substituting group, and a polymerizable unsaturation group in one 60 methacrylate groups for the acrylate groups in the above molecule, Such as dially lperoxydicarbonate, compounds, triallylcyanurate and triallyl trimellitate. t-butylperoxymaleic acid, t-butylperoxyallylcarbonate, and These crosslinking monomerS may preferably be used in t-butylperoxyisopropylfumarate. a proportion of 0.00001-1 wt. part, particularly about Among these, particularly preferred examples may 0.001-0.05 wt. part, per 100 wt. parts of the other monomer include: 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 65 components. 1,1-di-t-butyl per o Xy cyclohe Xane, di -t- Among the above-mentioned crosslinking monomers, butyl per o Xy he X a hydro te rephth a late, di-t- aromatic divinyl compounds (particularly, divinylbenzene) US 6,426,169 B1 19 20 and diacrylate compounds connected with a chain including polymer and a low-molecular weight polymer in, e.g., an an aromatic group and an ether bond may Suitably be used extruder; and a two-step polymerization method wherein a in a toner resin in View of fixing characteristic and anti-offset low-molecular weight polymer prepared by, e.g., Solution characteristic. polymerization is dissolved in a monomer for constituting a Other polymerization processes, Such as bulk polymer high-molecular weight polymer, and the resultant mixture is ization and Solution polymerization can also be utilized. The Subjected to Suspension polymerization, followed by wash bulk polymerization allows production of arbitrary polymer ing and drying of the polymerizate to provide a resin ization by adopting a high polymerization temperature pro composition. The two-step polymerization process is advan tageous for realizing uniform dispersion, but is accompanied Viding an accelerated termination reaction speed, but the with a difficulty that an unnecessary low-molecular weight reaction cannot be controlled easily. In contrast thereto, component is liable to be by-produced. The solution blend according to the Solution polymerization process, a low ing method is free from Such a problem and allows the molecular weight polymer can be produced under moderate inclusion of the low-molecular weight component in a larger conditions by utilizing the radical chain transfer function of amount than the high-molecular weight component, So that the Solvent and by adjusting the polymerization initiator it is most preferred. For the purpose of providing the amount or reaction temperature, So that the Solution poly 15 low-molecular weight component with a prescribed acid merization proceSS is preferred for formation of a low value, it is preferred to rely on the Solution polymerization molecular weight component possibly contained in the which allows easier Setting of the acid value than in the binder resin. It is also effective to perform the solution aqueous-System polymerization. polymerization under an elevated pressure, So as to SuppreSS Further, in the case of using a polyester resin in the binder the amount of the polymerization initiator to the minimum resin, the polyester resin may have a composition as and Suppress the adverse effect of the residual polymeriza described below. tion initiator. Examples of the alcohol component may include: diols, Examples of the monomer for providing the binder resin Such as ethylene glycol, propylene glycol, 1,3-butanediol, may include: Styrene, Styrene derivatives, Such as 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethyl O-methylstyrene, m-methylstyrene, p-methylstyrene, 25 ene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4- glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n- bisphenols and derivatives represented by the following butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- formula (A): octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n- dodecylstyrene; ethylenically unsaturated monoolefins, Such (A) as ethylene, propylene, butylene, and isobutylene; unsatur ated polyenes, Such as butadiene; halogenated vinyls, Such t as vinyl chloride, vinylidene chloride, vinyl bromide, and Horo-O- O-RO -H, Vinyl fluoride; Vinyl esters, Such as Vinyl acetate, Vinyl CH propionate, and Vinyl benzoate, methacrylates, Such as 35 methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, wherein R denotes an ethylene or propylene group, X and y n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl are independently an integer of at least 0 with the proviso methacrylate, Stearyl methacrylate, phenyl methacrylate, that the average of X-y is in the range of 0-10; diols dimethylaminoethyl methacrylate, and diethylaminoethyl 40 represented by the following formula (B): methacrylate; acrylates, Such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, (B) n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, Stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate, vinyl ethers, such as vinyl methyl ether, vinyl ethyl ether, 45 -to-on-O-o-to and vinyl isobutyl ether, Vinyl ketones, Such as vinyl methyl CH ketone, Vinyl hexyl ketone, and methyl isopropenylketone; wherein R denotes -CHCH- , -CH2- hi- O N-Vinyl compounds, Such as N-Vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinyl pyrrolidone; CH Vinylnaphthalenes, acrylic acid derivatives or methacrylic 50 -CH- - acid derivatives, Such as acrylonitrile, methacryronitrile, and acrylamide; the esters of the above-mentioned C.B- hi, unsaturated acids and the diesters of the above-mentioned dibasic acids. These vinyl monomers may be used singly or and X’ and y' are independently an integer of at least 0 with in combination of two or more species. 55 the proviso that the average of x' +y' is in the range of 0-10. Among these, a combination of monomers providing Examples of the dibasic acid may include dicarboxylic Styrene-polymers or Styrene copolymers inclusive of acids and derivatives thereof inclusive of: aromatic dicar Styrene-acrylic type copolymerS may be particularly pre boxylic acids, Such as phthalic acid, terephthalic acid and ferred. isophthalic acid, and their anhydrides, alkyldicarboxylic For providing the binder resin having the above 60 acids, Such as Succinic acid, adipic acid, Sebacic acid and mentioned specific molecular weight distribution used in the aZelaic acid, and their anhydrides and lower alkyl esters present invention, it is possible to rely on various methods, thereof; alkenyl- or alkyl-Succinic acids, Such as inclusive of a Solution blending method wherein a high n-dodecenylsuccinic acid and n-dodecylsuccinic acid, and molecular weight polymer and a low-molecular weight their anhydrides and lower alkyl esters thereof, and unsat polymer are Separately produced and are blended in a 65 urated dicarboxylic acids, Such as fumaric acid, maleic acid, solution state, followed by removal of the solvent; a dry citraconic acid and itaconic acid, and their anhydrides and blending method of melt-kneading a high-molecular weight lower alkyl esters thereof. US 6,426,169 B1 21 22 It is preferred to also include a polyhydric alcohol com gold, platinum, tungsten, molybdenum, niobium, osmium, ponent having at least three hydroxyl groups and/or a Strontium, yttrium, technetium, luthenium, rhodium, and polycarboxylic acid component having at least three car bismuth. More preferably, the non-iron element may be boxyl groups. Selected from lithium, beryllium, boron, magnesium, Examples of the polyhydric alcohol having at least three aluminum, Silicon, phosphorus, germanium, Zirconium, tin, hydroxyl groups may include: Sorbitol, 1,2,3,6-hexanetetrol, Sulfur, calcium, Scandium, titanium, Vanadium, chromium, 1,4-Sorbitan, pentaerythritol, dipentaerythritol, manganese, cobalt, nickel, copper, Zinc and gallium. It is tripentaerythritol, 1,2,4-butane triol, 1,2,5-pentanetriol, particularly preferred to use a magnetic iron oxide contain glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, ing a non-iron element Selected from the group consisting of trimethylolethane, trimethylolpropane, and 1,3,5- magnesium, aluminum, Silicon, phosphorus and Sulfur. Such trihydroxybenzene. a non-iron element may be incorporated in the magnetic iron Examples of the polycarboxylic acid having at least three oxide crystal lattice, may be incorporated as an oxide thereof carboxyl groups may include polycarboxylic acids and in the iron oxide, or may be present as an oxide or a derivatives thereof inclusive of trimelitic acid, pyromellitic hydroxide thereof at the Surface of magnetic iron oxide acid, 1,2,4-benzene tricarboxylic acid, 1,2,5- 15 particles. It is preferred that the non-iron element is incor benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic porated as an oxide thereof. acid, 1,2,4 -naphthalene tricarboxylic acid, 1,2,4- Such a non-iron element may be incorporated in the butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, magnetic iron oxide particles by causing a Salt of the 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra non-iron element to be co-present in an iron Salt aqueous (methylene carboxyl)me thane, 1,2,7,8- octane - Solution at the time of formation of the magnetic iron oxide tetracarboxylic acid, Empole trimer acid, and anhydrides and adjusting the pH of the System. Further, Such a non-iron and lower alkyl esters of these, and tetracarboxylic acids element may be precipitated at the Surface of the magnetic represented by the following formula, and anhydrides and iron oxide particles by Subjecting a slurry containing mag lower alkyl esters thereof: netic iron oxide particles after the formation thereof to a pH 25 adjustment or addition of a Salt of Such a non-iron element, HOOCCH-X-CHCOOH followed by a pH adjustment. A magnetic iron oxide containing Such a non-iron element HOOCCH2 CHCOOH, as described above shows a good affinity with the binder resin and a good dispersibility in the binder resin. Further, wherein X denotes an alkylene group or alkenylene group of the good dispersibility of the magnetic iron oxide promotes 1-30 carbon atoms having at least one Side chain of at least the dispersion of the azo iron compound used in the present one carbon atom. invention, thus allowing full exhibition of the effect of the It is preferred that the alcohol component(s) may occupy aZO iron compound. More specifically, the magnetic iron 40-60 mol. %, preferably 45-55 wt. %, and the acid oxide particles function as a dispersion medium (a disper component(s) may occupy 60–40 mol. 76, respectively, of 35 Sion promoter) to aid the dispersion of the azo iron com the polyester forming monomers components. It is preferred pound. Further, Such a non-iron element-containing mag that the polyhydric alcohol having at least three hydroxyl netic iron oxide is moisture-absorptive to Some extent and groups may occupy 1-60 mol. 7% of the total components. has a function of promoting the chargeability of the azo iron Similarly, it is preferred that the polycarboxylic acid having compound due to the moisture. at least three carboxyl group may occupy 1-60 mol.% of the 40 Further, a uniform particle size distribution of the mag total components. netic iron oxide particles advantageously affects the Stabi The polyester resin may be produced through an ordinary lization of toner chargeability in association with a good polycondensation process. dispersibility thereof in the binder resin. In the case of constituting the toner of the present inven The non-iron element may preferably be contained in a tion as a magnetic mono-component toner, a magnetic 45 proportion of 0.05-10 wt.%, more preferably 0.1-7 wt.%, material is incorporated in the toner. The magnetic material further preferably 0.2-5 wt.%, more preferably 0.3–4 wt.%, used for this purpose may for example comprise: an iron based on the magnetic iron oxide. If the content is below the oxide Such as magnetite, maghemite or ferrite; a metal, Such above-mentioned range, the addition effect thereof is Scarce. as iron, cobalt or nickel, or an alloy of these metals with In excess of the above range, the resultant magnetic iron another metal, Such as aluminum, cobalt, copper, lead, 50 oxide particles are liable to cause excessive charge liberation magnesium, tin, Zinc, antimony, beryllium, bismuth, to result in an insufficient chargeability, thus causing a lower cadmium, calcium, manganese, Selenium, titanium, tungsten image density and increased fog. or Vanadium. It is preferred that the magnetic material It is preferred that Such a non-iron modifier element is contains a non-iron element at the Surface or inside of the predominarily present in proximity to the Surface of the particles thereof. 55 magnetic particles. For example, when magnetic iron oxide More Specifically, the magnetic material used in the particles are dissolved to a dissolution percentage of 20% of present invention may preferably comprise a magnetic iron the ion content, it is preferred that 20 to 100% of the total oxide, Such as magnetite, maghemite or ferrite containing a non-iron element is dissolved, more preferably 25-100%, different element or non-iron element. Such a magnetic iron further preferably 30-100%. The predominant presence at oxide not only imparts the toner with good chargeability and 60 the Surface of the non-iron element promotes the disperS magnetism but also functions as a colorant. ibility and electric diffusibility enhancing effects thereof It is preferred that the magnetic iron oxide contains at onto the magnetic particles. least one element Selected from lithium, beryllium, boron, The magnetic particles may preferably have a number magnesium, aluminum, Silicon, phosphorus, Sulfur, average particle size of 0.05-1.0 lim, more preferably germanium, titanium, Zirconium, tin, lead, Zinc, calcium, 65 0.1-0.5 um, and a BET specific area of 2–40 m/g, more barium, Scandium, Vanadium, chromium, manganese, preferably 4–20 m/g. The magnetic particles may assume cobalt, copper, nickel, gallium, indium, Silver, palladium, an arbitrary particle shape without particular restriction. The US 6,426,169 B1 23 24 magnetic particles may preferably have magnetic properties added as a dispersant, and 2 to 20 mg of a Sample is added including a saturation magnetization of 10–200 Am/kg, thereto. The resultant dispersion of the Sample in the elec more preferably 70-100 Am/kg, as measured under a trolytic liquid is Subjected to a dispersion treatment for about magnetic field of 795.8 kA/m, a residual magnetization of 1-3 minutes by means of an ultraSonic disperser, and then 1-100 Am/kg, more preferably 2- 20 Am/kg, and a Subjected to measurement of particle Size distribution in the coercive force of 1-30 kA/m, more preferably 2-15 kA/m. range of at least 2 um by using the above-mentioned The magnetic material may preferably be used in 20-200 wt. apparatus with a 100 um-aperture to obtain a Volume-basis parts, more preferably 40-150 wt. parts, per 100 wt. parts of the binder resin. distribution and a number-basis distribution. The weight The contents of various elements may be measured by average particle size (D) may be obtained from the Volume fluorescent X-ray analysis according to JIS KO119 basis distribution by using a central value as a representative (fluorescent X-ray analysis-general rules) by using a fluo value for each channel. rescent X-ray analyzer (e.g., “SYSTEM 3080”, available The following 13 channels are used: 2.00-2.52 um; from Rigaku Denki Kogyo K.K.). The determination of 2.52-3.17 um; 3.17-400 um; 400–5.04 um; 5.04–6.35um; distribution of respective elements may be performed by ICP 6.35-8.00 um; 8.00-10.08 um; 10.08-12.70 um; 15 12.70–16.00 um; 16.00–20.20 um; 20.20–25.40 um; (inductively coupled plasma) emission spectroscopy of 25.40-32.00 um; and 32.00-40.30 tum. For each channel, a gradually formed Solutions at various degrees of dissolution lower limit value is included, and an upper limit value is in hydrochloric acid or hydrofluoric acid for determination excluded. of concentrations of respective elements in the Solutions The toner according to the present invention can contain relative to the concentrations of the respective elements at a wax, examples of which may include; paraffin waxes and full dissolution to determine the dissolution percentages of derivatives thereof, montan wax and derivatives thereof; the respective elements for each gradually formed Solution. microcrystalline wax and derivatives thereof; Fischer The number-average particle size of magnetic particles TropSche wax and derivatives thereof; polyolefin waxes and may be determined by taking enlarged photographs taken derivatives thereof, and carnauba wax and derivatives through a transmission electron microscope and processing 25 thereof. The derivatives may include: oxides, block copoly images of particles on the enlarged photographs by a merS and graft-modified products with vinyl monomers. digitizer, etc., to determine a particle size distribution and a The toner according to the present invention may effec number-average particle Size therefrom. Further, the mag tively contain one or more species of wax in a total amount netic properties described herein are based on values mea of 0.1-15 wt. parts, preferably 0.5-12 wt. parts, per 100 wt. sured by applying an external magnetic field of 795.8 kA/m parts of the binder resin. by using a vibrating sample-type magnetometer (“VSM-3S The toner according to the present invention contains a 15', available from Tosei Kogyo K.K.). The specific surface colorant. Examples thereof may include a magnetic iron areas are based on values measured according to the BET oxide as mentioned above, and also appropriate pigments multi-point method using nitrogen gas as adsorbent on a and dyes. Examples of the pigments may include: carbon Sample Surface by using a specific Surface area meter 35 black, aniline black, acetylene black, Naphthol Yellow, (“Autosorb 1', available from Yuasa Ionics K.K.). Hansa Yellow, Rhodamine Lake, Alizarin Lake, Phthalocya In recent years, the use of Smaller particle Size toners has nine Blue, and Indanthrene Blue. These pigments may be become popular. The toner of the present invention can used in an amount necessary and Sufficient to provide a fixed exhibit a uniform chargeability and lower agglomeratability, 40 image with a desired optical density, e.g., in 0.1-20 wt. thus providing images with an increased image density even parts, preferably 0.2-10 wt. parts per 100 wt. parts of the at a small weight-average particle size (D4) of 2.5-10 um. binder resin. For a similar purpose, a dye may be used, and The effects are particularly noticeable at a weight-average examples thereof may include: azo dyes, anthraquinone particle size of 2.5-6.0 um. D4 of at least 2.5 um is preferred dyes, Xanthene dyes and methine dyes. The dye may be So as to provide a Sufficient image density. On the other 45 added in 0.1-20 wt. parts, preferably 0.3-10 wt. parts per hand, at a Smaller toner particle size, the liberation of the azo 100 wt. parts of the binder resin. iron compound is liable to be promoted though the azo iron The toner according to the present invention may prefer compound used in the present invention is relatively leSS ably contain fine powder of inorganic materials inclusive of liable to be liberated because of a good affinity with the inorganic oxides, Such as Silica, alumina and titanium oxide, binder resin. However, as the toner of the present invention 50 and carbon black and fluorinated carbon externally added to has an excellent uniform chargeability, the performance the toner particles. thereof is less disadvantageously affected even Some iso Such inorganic fine powder may preferably be dispersed lated azo iron compound is co-present. The above in fine particles on the Surface of toner particles So as to mentioned preferred weight-average particle size (D4) exhibit a high flowability improvement effect. Accordingly, ranges are applicable to both a magnetic toner and a non 55 the inorganic fine powder may preferably have a number magnetic toner. average particle size of 5-200 nm, more preferably 10-100 The particle size distribution and weight-average particle nm, and a specific Surface area as measured by the BET Size (D4) may be measured according to the Coulter counter method according to nitrogen adsorption of at: least 30 m/g, method, e.g., by using Coulter Multisizer (=trade name, 60 more preferably 60–400 ml/g, in a state before surface available from Coulter Electronics Inc.). treatment and at least 20 m/g, more preferably 40–300 In the measurement, a 1%-NaCl aqueous Solution may be m/g, in a state after Surface treatment. prepared by using a reagent-grade Sodium chloride as an Such fine powder may preferably be added in 0.03-5 wt. electrolytic solution. It is also possible to use ISOTON R-II parts per 100 wt. parts of the toner particles So as to provide (available from Coulter Scientific Japan K.K.). Into 100 to 65 an adequate Surface coverage rate. 150 ml of the electrolytic solution, 0.1 to 5 ml of a The inorganic fine powder may preferably exhibit a Surfactant, preferably an alkylbenzeneSulfonic acid Salt, is hydrophobicity in terms of a methanol wettability of at least US 6,426,169 B1 25 26 30%, more preferably 50% or higher, e.g., by surface erably Suspension polymerization; a proceSS for producing a treatment with a hydrophobization agent, preferred microcapsule toner comprising a core and a shell, at least examples of which may include Silicon-containing Surface one of which contains prescribed toner components, and a treating agents of Silane compounds and Silicone oil. process for dispersing in a binder resin Solution other toner Specific examples of the Silane compounds may include: ingredients and Spray-drying the resultant mixture. The alkylalkoxysilanes, Such as dimethyldimethoxysilane, trim thus-obtained toner particles may be blended with desired ethylethoxysilane and butyltrimethoxysilane; and further external additives by a blender, Such as a Henschel mixer to dimethyldichloro Silane, trimethylchloro Silane, obtain a toner according to the present invention. allyldimethylchlorosilane, hexamethyldisila Zane, Various machines are commercially available for the allylphenyldichlorosilane, benzy dimethylchlorosilane, above process. Several examples thereof are enumerated Vinyl trie thoxy Silane, below together with the makers thereof. For example, the y - me thacryloxypropyl trime thoxy Silane, commercially available blenders may include: Henschel Vinyltriacetoxysilane, divinylchlorosilane and dimethylvii nylchlorosilane. mixer (mfd. by Mitsui Kozan K.K.), Super Mixer (Kawata 15 K.K.), Conical Ribbon Mixer (Ohkawara Seisakusho K.K.); The toner according to the present invention can also be Nautamixer, Turbulizer and Cyclomix (Hosokawa Micron blended with a carrier to form a two-component developer. K.K.); Spiral Pin Mixer (Taiheiyo Kiko K.K.), Lodige Mixer The carrier may preferably exhibit a resistivity of 10°-10' (Matsubo Co. Ltd.). The kneaders may include: Buss ohm.cm by adjusting a Surface roughness and an amount of Cokneader (Buss Co.), TEM Extruder (Toshiba Kikai K.K.), a Surface-coating resin. TEX Twin-Screw Kneader (Nippon Seiko K.K.), PCM Examples of the carrier Surface-coating resin may Kneader (Ikegai Tekko K.K.); Three Roll Mills, Mixing Roll include: Styrene-acrylate ester copolymer, Styrene Mill and Kneader (Inoue Seisakusho K.K.), Kneadex methacrylate ester copolymer, acrylate ester copolymer, (Mitsui Kozan K.K.); MS-Pressure Kneader and Kneader methacrylate ester copolymer, Silicone resin, fluorine Suder (Moriyama Seisakusho K.K.), and Bambury Mixer containing resin, polyamide resin, ionomer resin, polyphe 25 (Kobe Seisakusho K.K.). As the pulverizers, Cowter Jet nylene Sulfide, and mixtures of these. Mill, Micron Jet and Inomizer (Hosokawa Micron K.K.); The carrier core may comprise a magnetic material, IDS Mill and PJMJet Pulverizer (Nippon Pneumatic Kogyo examples of which may include: oxides, Such as ferrite, iron K.K.); CrossJet Mill (Kurimoto Tekko K.K.), Ulmax (Nisso exceSS-type ferrite, magnetite and Y-iron oxide; metals, Such Engineering K.K.), SK Jet O. Mill (Seishin Kigyo K.K.), as iron, cobalt and nickel, and alloys of these. These Krypron (Kawasaki Jukogyo K.K.), and Turbo Mill (Turbo magnetic materials may further contain an additional Kogyo K.K.). As the classifiers, Classiell, Micron Classifier, element, Such as iron, cobalt, nickel, aluminum, copper, and Spedic Classifier (Seishin Kigyo K.K.), Turbo Classifier lead, magnesium, tin, Zinc, antimony, beryllium, bismuth, (Nisshin Engineering K.K.); Micron Separator and Tur calcium, manganese, Selenium, titanium, tungsten, or Vana 35 boplex (ATP); Micron Separator and Turboplex (ATP); TSP dium. Separator (Hosokawa Micron K.K.); Elbow Jet (Nittetsu Further, in order to provide the toner with improved Kogyo K.K.), Dispersion Separator (Nippon Pneumatic developing performance and continuous image forming Kogyo K.K.), YM Microcut (Yasukwa Shoji K.K.). As the performance, it is also preferred to externally add powders Sieving apparatus, Ultrasonic (Koei Sangyo K.K.), Rezona of inorganic materials as followS. Namely, oxides of metals, 40 Sieve and Gyrosifter (Tokuju Kosaku K.K.), Ultrasonic Such as magnesium, Zinc, aluminum, cerium, cobalt, iron, System (Dolton K.K.), Sonicreen (Shinto Kogyo K.K.), Zirconium, chromium, manganese, Strontium, tin and anti Turboscreener (Turbo Kogyo K.K.), Microshifter (Makino mony; composite metal oxides, Such as calcium titanate, Sangyo K.K.), and circular vibrating sieves. magnesium titanate, and Strontium titanate, metal Salts, Such Hereinafter, the present invention will be described more as calcium carbonate, magnesium carbonate, magnesium 45 Specifically based on Examples, which however should not carbonate, and aluminum carbonate, clay minerals, Such as be understood to restrict the Scope of the present invention kaolin, phosphate compounds, Such as apatite; Silicon in any way. In the following Examples, "part(s) means compounds, Such as Silicon carbide, and Silicon nitride; and “part(s) by weight”. carbons, Such as carbon black and graphite. It is also possible to add powder of a lubricant to the toner. 50 Production Example 1 for Azo Iron Compound Examples of the lubricant may include: fluorine-containing resins, Such as polytetrafluoroethylene and polyvinylidene A monoaZo compound Synthesized by an ordinary cou fluoride, and fluorine-containing compounds, Such as fluori pling reaction between 4-chloro-2-aminophenol and 6-t- nated carbon. octyl-2-naphthol was added to N,N-dimethylformamide The toner according to the present invention may prefer 55 under Stirring. Into the Solution, Sodium carbonate was ably be produced through a pulverization process wherein added and the mixture was heated to 70° C., followed by the toner ingredients as mentioned above are Sufficiently addition of Fe(II)SO.7H2O and 5 hours of reaction. The blended in a blender, such as a ball mill, melt-kneaded by hot System was cooled to room temperature by Standing, and a kneading means, Such as a hot roller kneader and an precipitated product was filtered out and added into extruder, Solidified by cooling, mechanically pulverized by 60 isopropanol, followed by dissolution by re-heating to 70° C. a pulverizer and classified by a classifier to obtain toner and cooling by Standing to precipitate an azo iron com particles. However, it also possible to rely on a polymeriza pound. The compound was filtered out, washed with water tion toner production proceSS wherein a monomer for con and dried to obtain AZO iron compound (1) represented by Stituting a binder resin is mixed with other toner ingredients 65 the following formula. AZO iron compound (1) provided an to form a polymerizable composition, and the composition X-ray diffraction spectrum as shown in FIG. 1 and exhibited is Subjected to polymerization in an aqueous medium, pref a crystallinity of 68.0%. US 6,426,169 B1 27 28 4-chloro-2-aminophenol for Synthesis of a monoaZo com (1) pound. AZO iron compound (3) exhibited a crystallinity of 66.8%. H.C. CH' Ca 5 (3) H.C. ' CH3 Ca CH
1O
O | O O DFeCNo Nat 15
Nat K) C 2O HC CS H: CH3 H3C Sca HC CH 25
Production Example 2 for Azo Iron Compound AZO iron compound (2) represented by a formula shown below was prepared in the same manner as in Production Example 1 except for using 4-t-pentyl-2-aminophenol in Production Example 4 for Azo Iron Compound place of 4-chloro-2-aminophenol for Synthesis of a monoazo AZO iron compound (4) represented by a formula shown compound. AZO iron compound (2) exhibited a crystallinity below was prepared in the same manner as in Production of 67.2%. 35 Example 1 except for using 6-t-butyl-2-naphthol in place of 6-t-octyl-2-naphthol for Synthesis of a monoaZo compound. (2) Azo iron compound (4) exhibited a crystallinity of 65.8%. CH HCN4 3 (4) cf. YOH 40 HCJ' CH3 Ca H3CN / CH CN CH'RCH, CH -C HC 45
sh- O Nat o1 No 50 ON F-1 O Nat O1. No -CH HC1 V 55 ( ) NE CHs H3C HC CN CH3 H3C/ HC y NCH, / YOH, HC 60 HC
Production Example 3 for Azo Iron Compound Production Example 5 for Azo Iron Compound AZO iron compound (3) represented by a formula shown 65 AZO iron compound (5) represented by a formula shown below was prepared in the same manner as in Production below was prepared in the same manner as in Production Example 1 except for using 2-aminophenol in place of Example 1 except for using 6-methyl-2-naphthol in place of US 6,426,169 B1 29 30 6-t-octyl-2-naphthol for Synthesis of a monoaZo compound. Azo iron compound (5) exhibited a crystallinity of 63.0%. (7) (5) CH,\ HC
Cl NFN 1O st- Nat O O Na 15 O O
( ) NE 2O CH
Cl
25
Production Example for AZO Chromium Compound Production Example 6 for Azo Iron Compound 30 AZO chromium compound (8) represented by a formula shown below was prepared in a similar manner as in AZO iron compound (6) represented by a formula shown Production Example 1 except for using 2-naphthol and below was prepared in the same manner as in Production 4-t-pentyl-2-aminophenol for Synthesis of a monoazo Example 1 except for using 3-n-butyl-2-naphthol in place of compound, and using chromium (III) formate in place of 6-t-octyl-2-naphthol for synthesis of a monoazo compound. 35 Fe(II)SO4.7H2O. AZO chromium compound (8) exhibited a Azo iron compound (6) exhibited a crystallinity of 64.8%. crystallinity of 60.7%. (6) (8) 40 2' ch C Y1 3 HC
45 N t- Nat N 1. O Na O ( ) NEN 50 ( ) NEN ( ) -CH3 C2H5
Production Example 7 for Azo Iron Compound 60 Production Example 9 for Azo Iron Compound
AZO iron compound (7) represented by a formula shown AZO iron compound (9) represented by a formula shown below was prepared in the same manner as in Production below was prepared in the same manner as in Production Example 1 except for using 2-naphthol and 4-methyl-2- 65 Example 1 except for using 2-naphthol in place of 6-t-octyl aminophenol for Synthesis of a monoaZo compound. AZO 2-naphthol for Synthesis of a monoaZo compound. AZO iron iron compound (7) exhibited a crystallinity of 62.2%. compound (9) exhibited a crystallinity of 59.6%. US 6,426,169 B1 31 32 solvent to obtain Polymer (L1) of a low-molecular weight. (9) Polymer (L1) provided a GPC chromatogram showing a peak molecular weight (Mp) of 15000 and an acid value of 30.0 mgkOH/g. The polymerization composition, peak molecular weight (Mp) and acid value of Polymer (L1) are shown in Table 1 together with those of polymers obtained ( ) in the following Polymer Production Examples. Polymer Production Examples 2-6 Polymers (L2)-(L6) of low molecular weight were pre pared in the same manner as in Polymer Production on 3 Nat Example 1 except for changing polymerization composi st tions (respective monomer amounts and initiator amounts 15 and addition of divinylbenzene as desired) as shown in Table 1. s 1. Polymer Production Example 7 Into a four-necked flask, 180 parts of deaerated water and (-t-)Cl 20 parts of 2 wt.%-polyvinyl alcohol aqueous solution were placed, and a liquid mixture of 78.4 parts of Styrene, 20 parts of n-butyl acrylate, 1.6 parts of monobutyl maleate and 0.18 part of 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, was added thereto, followed by Stirring to form a Suspension 25 liquid. After the interior of the flask was sufficiently aerated Production Example 10 for Azo Iron Compound with nitrogen, the system was heated to 90° C. to initiate the polymerization. The System was held at that temperature for The procedure of Production Example 7 was repeated up 24 hours to complete the polymerization. The polymerizate to the addition and reaction of Fe(II)SO4.7HO. Thereafter, the System was cooled by Standing to room temperature, and was filtered out, washed with water and dried to obtain the reaction liquid was not Subjected to the precipitation or Polymer (H1) of high molecular weight. Polymer (H1) crystallization in isopropanol but was dispersed in N,N- provided a GPC chromatogram showing Mp=8x10 and dimethylformamide (DMF), followed by recovery by exhibited an acid value of 5.1 mgKOH/g. filtration, Washing with water and drying to obtain AZO iron Polymer Production Examples 8-10 compound (10) in an amorphous state. AZO iron compound 35 (10) exhibited a crystallinity of 13.8%. Polymers (H2)-(H4) of high molecular weight were pre Some binder resins were prepared generally through two pared in the same manner as in Polymer Production StepS as shown in the following production examples. Example 7 except for changing polymerization composi tions (respective monomer amounts and initiator amounts Polymer Production Example 1 40 and addition of divinylbenzene as desired) as shown in Table 1. 300 parts of Xylene was placed in a four-necked flask, and the interior of the flask was sufficiently aerated with nitrogen Polymer Production Example 11 under Stirring. Then, the Xylene was heated and Subjected to refluxing. Under the reflux condition, a liquid mixture of Polymer (H5) of high molecular weight was prepared in 68.8 parts of Styrene, 22 parts of n-butyl acrylate, 9.2 parts 45 the same manner as in Polymer Production Example 1 of monobutyl maleate and 1.8 parts of di-tert-butyl peroxide except for changing polymerization compositions was added dropwise in 4 hours and held for 2 hours for (respective monomer amounts and initiator amounts add completing the polymerization, followed by removal of the addition of divinylbenzene as desired) as shown in Table 1.
TABLE 1. Polymers Polwmerization composition (wt. parts
Monomers Initiators and DVB Acid value Polymer MBM Sty nBA DTBP DVB BBCP Mp (x10) (mgKOH/g) L1 9.2 68.8 22 18 15 3O.O L2 O1 79.9 2O 2.2 1O O.3 L3 8.8 70.2 21 1.5 22 28.3 L4 1.4 78.6 2O 2.5 7 4.4 L5 28.4 49.6 22 1.9 14 93.1 L6 7.8 71.2 21 0.5 O.1 70 25.2 H1 1.O 78.4 2O O.18 8OO 5.1 H2 2.4 77.6 2O O.22 550 7.8 78.0 2O O.O1 O16 108O 7.1 US 6,426,169 B1 33 34
TABLE 1-continued Polymers Polwmerization composition (wt. parts
Monomers Initiators and DVB Acid value Polymer MBM Sty nBA DTBP DVB BBCP Mp (x10) (mgKOH/g) H4 8O.O 2O O.2O 78O O.1 HS O.9 79.1 2O 0.5 O.15 150 3.0 *MBM = monobutyl maleate, Sty = styrene, nBA = n-butyl acrylate, DTBP = di-t-butyl peroxide, DVB = divinylbenzene, BBCP = 2.2-bis(4,4-di-t-butylperoxycyclohexyl)propane.
Binder Production Example 1 15 Saturation magnetization, Or=residual magnetization, Hc=coercive force) and the dissolution rate (%) of the Polymer (L1) and Polymer (H1) were blended in solvent non-Fe element at 20% dissolution of Fe, and the number Xylene and the solvent was removed to obtain Binder resin average particle size (Dn) of the magnetic materials, are also 1. shown in Table 3.
TABLE 3 Magnetic materials Dissolution (%) at 20%. Fe Magnetic Non-Fe element Dn dissolution CSS CS Hc material (wt.%) (um) Si Al (Am/kg) (Am/kg) (kA/m)
al Si = 0.5 O.22 71.3 99.5 85.1 5.3 5.2 Al = 0.2 b Si = 0.5 O.2O 60.4 82.3 4.0 3.7 C O.21 84.6 4.7 4.7
35 Binder Production Examples 2-7 (Preparation and Evaluation of Toners) Binder resins 2-7 were prepared in the same manner as in EXAMPLE 1. Binder Production Example 1 except for changing the species of Polymers to be blended as shown in Table 2. 40 The glass transition temperature (Tg) and acid values of Binder resin 1 100 parts Magnetic material a 95 parts the thus-prepared binder resins are also shown in Table 2. Polypropylene wax 4 parts AZO iron compound (1) 2 parts TABLE 2 45 Binder resin The above ingredients were melt-kneaded by means of a Binder Polymers Tg Acid-value twin-screw extruder heated at 130 C. After cooling, the resin (7:3) ( C.) (mgKOHg) kneaded product was coarsely crushed by a hammer mill and 1. L1 H1 60.2 23.2 50 then finely pulverized by a jet mill. The pulverizate was 2 L2 H2 62.3 2.5 classified by a fixed wall-type pneumatic classifier to obtain 3 L3 H3 61.2 21.0 classified powder, which was further subjected to strict 4 L4 H2 60.8 5.4 5 L5 H2 58.9 71.5 classification by means of a multi-division classifier 6 L2 H4 62.7 O.2 (“Elbow Jet”, made by Nittetsu Kogyo K.K.) utilizing the 7 L1 HS 59.5 21.8 55 Coanda effect for removal of fine powder fraction and coarse powder fraction to obtain Toner 1 of negative chargeability having a weight-average particle size (D4) of 6.8 um. Physical properties of Toner 1 thus obtained are shown in Production of Magnetic Materials Table 4 together with those of toners prepared in other 60 Examples and Comparative Examples described hereinafter. Magnetic materials (magnetic iron oxides) a, b and c Toner 1 in 100 wt. parts was blended with 1.2 wt. parts of shown in Table 3 below were prepared by varying the hydrophobic silica fine powder by means of a Henschel Species and amount of non-Fe elements (added in the form mixer to obtain a developer (a monocomponent magnetic of salts) and by changing pH adjustment conditions during toner). The developer was evaluated in the following manner production of magnetic iron oxide. The non-Fe element 65 and the evaluation results are shown in Table 5 together with contents shown in Table 3 are expressed in wt.% based on those of the other Examples and Comparative Examples. the magnetic iron oxide. The magnetic properties (OS= (Image Forming Test) US 6,426,169 B1 35 36 A commercially available laser beam printer (“LBP-930”, C: White spotty dropouts are observed in the solid black made by Canon K.K.) was remodeled So as to increase the ImageS. paper feed rate of 24 A4-size lateral sheets/min. to a paper D: White Spotty dropouts and shooting Star-like dropouts are observed in the Solid black images. feed rate of 40A4-Size lateral sheets/min. by increasing the (4) Fixing Performance (T, and T) proceSS Speed to 200 mm/sec. and provide fixing conditions The hot pressure fixation device of the above-mentioned of a total pressure of 30 kg and a nip of 8 mm between the laser beam printer was remodeled So as to allow a heating heating roller and the pressure roller in the fixing device. The roller surface temperature setting in a range of 120 C-250 above-prepared Toner 1 was charged in a process cartridge C. Image formation was formed while changing the roller for the above-remodeled laser beam printer. The outline of Surface temperature in the range by an increment of 5 C. the proceSS cartridge is illustrated in FIG. 2. each in the normal temperature/normal humidity environ Referring to FIG. 2, a developing device 1 includes a ment. developer vessel 2 for Storing a developer (toner) 13, a (Low Temperature Fixability-T ( C.) developing sleeve 6 for carrying the developer 13 in the Printing was performed on plain paper of 90 g/m giving developer vessel 2 from the developer vessel 2 to a devel a hard fixing condition. The resultant printed image was oping region where the developing sleeve 6 becomes oppo 15 rubbed with Soft tissue paper (lens cleaning paper) under a Site to an electroStatic latent image-bearing member load of 50 g/cm. A minimum temperature giving an image (photosensitive drum)3, an elastic blade 8 for regulating the density lowering of 10% or less due to rubbing compared developer carried on the developing sleeve 6 into a thin layer with that before rubbing was recorded as a fixing initiation temperature (T. (C.)). of a prescribed thickneSS on the developing Sleeve, and a (Anti-high Temperature Offset Property—T (C)) magnet 15 enclosed within the developing sleeve 6. The A Sample image having an areal image percentage of ca. elastic blade 8 is supported by a support member 9 and 5% was printed out on plain paper of 60 g/m· liable to cause abutted against the developing sleeve 6 Surface. The car offset and fixed at various temperatures So as to observe the tridge also includes the photosensitive drum 3, and a clean State of Soiling of the printed images. A maximum tempera ing device 14 including a cleaning blade 7 abutted against ture at which the images were free from Soiling due to offset the photosensitive drum 3 for removal of transfer residual 25 was determined as a high-temperature offset-free tempera toner from the photoSensitive drum. ture (Topset (e C.)). By using the above-remodeled laser beam printer, Toner The results of the evaluation with respect to the above 1 (as a sample toner) was Subjected to image forming tests items are shown in Table 5 together with those for the in normal temperature/normal humidity environment (23 following Examples and Comparative Examples. C./60%RH), a high temperature/high humidity environment (32.5° C./80%RH) and a low temperature/low humidity EXAMPLES 2-16 environment (15 C/10%RH). The image formation was Comparative Examples 1-4 performed in an intermittent mode of placing a pause period Toners 2-16 and Comparative Toners 1-4 were prepared of 20 Sec after every printing on two sheets. The images thus in the same manner as in Example 1 except for changing the formed were evaluated with respect to the following items. 35 toner prescriptions (species of Binder resin), Magnetic mate (1) Image Density (I.D.) rials and charge control agents (AZO iron compounds)) as Images were continuously printed on 15000 sheets of shown in Table 4. plain paper (75 g/m) for copying, and image densities were In Table 4, (L6) as Binder resin for Comparative measured at the initial Stage and the final Stage of the Examples 3 and 4 represents Polymer (L6), and AZO com continuous printing operation in terms of a relative density 40 pound (8) for Comparative Example 1 is AZO chromium compared with that of a white background portion corre compound (8) prepared in Production Example 8 and other sponding to an original image density of 0.00 by using a AZO compounds are all azo iron compounds of which AZO Macbeth densitometer (available from Macbeth Co.). iron compound (10) is amorphous and the other azo iron (2) Fog compounds are crystalline. Images were continuously printed on 15000 sheets of 45 Toners 2-16 and Comparative Toners 1-4 thus prepared plain paper (75 g/m) for copying in the low temperature/ were evaluated in the same manner as in Example 1, and the low humidity environment, and fog was evaluated at the results are shown in Table 5. initial Stage and the final Stage of the continuous printing Comparative Example 5 operation by measuring a whiteness of the plain paper before Comparative Toner 5 was prepared in the same manner as printing and a whiteness of a printed Solid white image 50 in Example 1 except for using Chromium complex com portion on the plain paper respectively by using a reflecto pound (11) of a formula shown below as a comparative meter (available from Tokyo Denshoku K.K.). The differ charge control agent instead of AZO iron compound (1) and ence in whiteneSS represents a fog. A Smaller fog value was evaluated in the same manner as in Example 1. The represents leSS fog. results of the evaluation are also shown in Table 5. (3) Toner Sticking 55 Images were continuously printed on 15000 sheets of (11) plain paper in the high temperature/high humidity environ ment. The photoSensitive drum Surface after the continuous Me H2O C printing was observed with eyes with respect to toner melt-Sticking onto the photoSensitive drum, and the effect 60 O O-C thereof on the Solid black images formed in the final Stage N H was also evaluated. The evaluation was performed accord Co ing to the following Standard. /\ A: No toner melt-Sticking observed on the photoSensitive so o- C drum. 65 B: Slight toner melt-Sticking is observed, but the images are not affected thereby. US 6,426,169 B1 37 38
TABLE 4 Toner Prescription and Properties GPC peak molecular Toner prescription weight (x10)
Binder Magnetic Azo (Fe) Lower Higher Acid value Example Toner resin material compound (um) MW peak MW peak (mgKOH/g)
6.8 666 22.7 6.8 675 22.9 6.9 68O 23 6.8 682 22.4 6.7 672 22.5 6.9 663 22.6 6.8 676 23.1 6.9 445 2.4 6.7 98O 20.5 7.0 451 5.1 6.8 433 70.3 6.8 668 O1 6.9 142 21.4 6.9 674 22.8 6.8 685 22.9 16 16 1. 6.9 674 22.8 Comp. 1 Comp. 1 6.8 670 22.9 Comp. 2 Comp. 2 7.0 661 22.6 Comp. 3 Comp. 3 (L6) 6.9 24.7 Comp. 4 Comp. 4 (L6) 6.8 24.6 Comp. 5 Comp. 5 6.9 668 22.8 *Compound (11) used in Comparative Example 5 was a Cr complex compound.
TABLE 5 Image density Fixation 32.5° C.f 15° C.f TFI T offset 80% RH 10% RH Fog Toner sticking Example ( C.) ( C.) initial final initial final 15 C/10% RH 32.5°C/80% RH 230 .40 37 42 1.39 O.6 230 39 36 .40 37 O.7 230 38 35 .41 38 O.7 230 35 31 36 33 1.2 230 29 26 3O 27 1.6 230 32 1.29 33 31 1.4 230 26 22 27 124 1.9 3 225 38 35 39 36 O.8 9 4 230 39 36 .40 36 O.7 225 38 34 39 35 O.8 11 225 37 1.33 38 35 O.9 12 230 2O .16 .21 18 2.5 13 3 22O 25 22 .27 1.23 2.0 14 230 .24 1.21 26 23 2.1 15 230 .21 17 22 119 2.3 16 230 18 .14 19 .16 2.7 Comp. 1 230 12 106 13 O8 3.3 Comp. 2 230 10 O5 12 106 3.4 Comp. 3 210 15 1O 17 112 3.1 Comp. 4 210 O5 O.98 O6 OO 3.8 Comp. 5 230 Of 1.OO O8 O2 3.6
What is claimed is: 60 the toner has a tetrahydrofuran-Soluble content providing 1. A toner comprising toner particles each comprising a a gel-permeation chromatogram showing at least one binder resin, a colorant and an organometallic compound, wherein peak in a molecular weight region of 3x10 to 5x10" the organometallic compound is an azo iron compound and at least one peak or shoulder in a molecular weight formed from a monoaZo compound having at least one 65 region of above 5x10" and at most 1x107, wherein the alkyl group and two hydroxyl groups capable of bond monoaZO compound is represented by any one of ing with an iron atom, and formulae (a)-(c) shown below: US 6,426,169 B1 39 40 9. The toner according to claim 1, wherein the azo iron compound is a compound represented by any one of for R2 R1 Rs R6 (a) mulae (d)-(f) shown below: 5 (d)
R4 OH HO R8 wherein R-Rs independently denote a hydrogen atom, a 1O halogen atom or an alkyl group with the proviso that at least (e) one of R-Rs is an alkyl group; O O o 2Fe (b) R14 R15 15 (SC)N / ) (f) R10 Ro ( ) R 16 (S7)ON/ O ) • 4Fe, wherein A and B in each of the above formulae (d), (e) and -- ( ) R17 (f), independently denote o-phenylene group or 1,2- R2 OH HO R18 naphthylene group with the proviso that at least one of A and B has at least one alkyl group and A and B each can further 25 have a halogen Substituent; and M denotes a cation Selected wherein Ro-Rs independently denote a hydrogen atom, a from the group consisting of hydrogen ion, alkali metalion, halogen atom or an alkyl group with the proviso that at least ammonium ion and organic ammonium ion. one of Ro-Rs is an alkyl group; and 10. The toner according to claim 1, wherein the azo iron (c) compound is contained in 0.1-10 wt. parts per 100 wt. parts R21 R20 R26 R27 of the binder resin. 11. The toner according to claim 1, wherein the azo iron compound is contained in 0.5-5 wt. parts per 100 wt. parts of the binder resin. R22 ( ) R19 R25 ( ) R28 12. The toner according to claim 1, wherein the toner has 35 a tetrahydrofuran-Soluble content providing a gel permeation chromatogram showing at least one peak in a R-( )---( )—is molecular weight region of 3x10 to 5x10" and at least one peak or shoulder in a molecular weight region of 1x10 to R24 OH HO R30 1x107. 40 13. The toner according to claim 1, wherein the toner has wherein Ro-Ro independently denote a hydrogen atom, a a tetrahydrofuran-Soluble content providing a gel halogen atom or an alkyl group with the proviso that at least permeation chromatogram showing at least one peak in a one of Rio-Rao is an alkyl group. molecular weight region of 3x10 to 3x10" and at least one 2. The toner according to claim 1, wherein the azo iron peak or shoulder in a molecular weight region of 1x10 to compound is a crystalline compound. 45 5X10. 3. The toner according to claim 1, wherein the monoaZo compound has at least one alkyl group having 4-12 carbon 14. The toner according to claim 1, wherein the toner has atOmS. an acid value of 0.5-100 mgKOH/g. 4. The toner according to claim 1, wherein the monoaZo 15. The toner according to claim 1, wherein the toner has compound has at least one alkyl group having 4-12 carbon 50 an acid value of 1.0–40 mgKOH/g. atoms including a tertiary carbon atom. 16. The toner according to claim 1, wherein the colorant 5. The toner according to claim 1, wherein the monoaZo is a magnetic iron oxide and is contained in 20–200 wt. parts compound has at least one alkyl group having 6-10 carbon per 100 wt. parts of the binder resin. atoms including a tertiary carbon atom. 17. The toner according to claim 16, wherein the magnetic 6. The toner according to claim 1, wherein the monoaZo iron oxide contains a non-iron element in a proportion of compound is a compound represented by the formula (b) in 55 0.05-10 wt.% based on the magnetic iron oxide. which at least one of the groups Ra-Rs is an alkyl group. 18. The toner according to claim 17, wherein the non-iron 7. The toner according to claim 1, wherein the monoaZo element is an element Selected from the group consisting of compound is a compound represented by the formula (b) in magnesium, aluminum, Silicon, phosphorus and Sulfur. which at least one of the groups R-Rs is an alkyl group 19. The toner according to claim 1, wherein the toner has having 4-12 carbon atoms including a tertiary carbon atom. 60 a weight-average particle size of 2.5-10 um. 8. The toner according to claim 1, wherein the monoaZo 20. The toner according to claim 1, wherein the toner has compound is a compound represented by the formula (b) in a weight-average particle size of 2.5-6.0 lim. which at least one of the groups Ra-Rs is an alkyl group having 6-10 carbon atoms including a tertiary carbon atom. k k k k k
