JP2007240828A - Oilless toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner suitable for even color copying or the like that can prevent an extreme reduction of viscosity or generation of stickiness and reduce the fixing energy by a wide non-offset temperature range by complete oilless property in a system using a mixture of a cyclic olefin resin and wax in an oilless toner for image formation. <P>SOLUTION: The oilless toner contains at least a binder resin, wax and a colorant, wherein the binder resin contains a cyclic olefin resin and polyvinyl acetal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner for electrophotography, and more particularly, to an oilless toner having a good fixability and having a low offset which is made of a cyclic olefin resin as a main material.

  Due to rapid technological innovation, high-quality images can be obtained in electrophotographic copying machines and printers, and a copy image that has excellent fixing properties and can prevent the offset phenomenon is demanded more than ever in order to reduce energy consumption. ing.

  One of the requirements for such high-quality images is the offset phenomenon, that is, the toner is not completely fixed on the substrate to be copied such as paper or film, and a part of the toner remains on the heating roller, which is fixed on the subsequent copying substrate. And preventing contamination. Further, as one of the demands for reducing the environmental load, since the non-offset temperature range is narrow, a large amount of energy is required for fixing, and this can be reduced.

  In Patent Document 1, an olefin polymer having a cyclic structure and having a high viscosity is selected as a binder for toner to prevent an offset phenomenon. Further, amide wax, carnauba wax, higher fatty acid and ester thereof, higher fatty acid metal are selected. It has been proposed to use a wax selected from soaps, partially saponified higher fatty acid esters, higher aliphatic alcohols, polyolefin waxes and paraffin waxes, but the non-offset range is in the range of 30 to 40 ° C. Absent.

Patent Document 2 proposes a combination of polar wax and nonpolar wax, but only an unsatisfactory result is obtained with respect to fixing of a Teflon (registered trademark) roller.
International Publication No. WO 98/29783 JP 2000-066438 A

  An object of the present invention is to solve the above-mentioned problems and prevent the occurrence of extreme viscosity reduction and stickiness in a system in which a cyclic olefin resin and a wax of an oilless toner for image formation are mixed and used. An object of the present invention is to provide a toner suitable for color copying and the like which has a non-offset temperature range due to its resilience and can reduce fixing energy.

The present inventors have found the present invention after verifying the prior art and clarifying the problems.
(Preliminary experiment / verification of conventional technology)
When actually converting to a toner based on a cyclic olefin resin, in order to provide offset resistance to the fixing roller, a wax having a melting point of 60 ° C. to 80 ° C. is mixed to obtain an oilless toner, and the offset property to the fixing roller is examined. It was. However, as a matter of fact, even when relatively polar waxes such as carnauba, fatty acid amides, polyethylene oxide, etc. are mixed with cyclic olefins, the cyclic olefin resin dissolves very well in these waxes, causing an extremely low viscosity and effective. A large rubber zone width could not be obtained. In addition, when a low polarity wax such as paraffin wax or polymerized olefin wax is used, the viscosity is further lowered, and an effective rubber width cannot be obtained. Furthermore, the same was true when these high polarity waxes and low polarity waxes were used in combination. To make matters worse, when these waxes are mixed, not only does the viscosity of the toner decrease too much to obtain a rubber width, but the toner becomes sticky and easily adheres to the fixing roller. This tendency occurs not only when the wax is mixed but also when a so-called charge control agent is mixed, and this is the biggest obstacle to using this cyclic olefin resin.

  Even if such toner is used, a roller or silicon roller coated with silicone oil can barely escape offset, but a system using these silicone oils or a system using silicon rollers is expensive. This is a disadvantage to the user.

  As a result of intensive studies on these problems, it has been found that by further mixing polyvinyl acetal in a system in which a cyclic olefin resin and a wax are mixed, an extreme decrease in viscosity and the occurrence of tackiness can be prevented.

That is, the said subject of this invention is achieved by the following means.
(1) An oilless toner containing at least a binder resin, a wax, and a colorant, wherein the binder resin contains a cyclic olefin resin and polyvinyl acetal.
(2) The oilless toner according to (1) above, wherein the mol% of the hydroxyl group in the polyvinyl acetal is 20 or more and 35 or less.
(3) The oilless toner according to (1) or (2), wherein the mixing ratio of the cyclic olefin resin and the polyvinyl acetal is 100: 10 to 10: 100.
(4) The oilless toner according to any one of (1) to (3), wherein a mixing ratio of the binder resin and the wax is 100: 50 to 100: 5.

(5) The oilless toner according to any one of (1) to (4), wherein the penetration of the wax at 25 ° C. is 40 or less.
(6) The wax according to any one of (1) to (5), wherein the wax contains at least one of carnauba, candelilla, montan, rice, esparto, caster ester and acid wax. The oilless toner described in 1.
(7) The wax contains at least one of paraffin, olefin, microcrystalline and these oxidized waxes as the second wax component, and the ratio of the second wax component to the total wax is 5 to 35% by weight. The oilless toner as described in (6) above, wherein

(8) A developer using the oilless toner according to any one of (1) to (7).
(9) In an image forming method comprising an electrostatic charge image carrier, at least a charging step, an exposure step, a development step, a transfer step, and a fixing step, the development step holds toner, An image forming method using the oilless toner according to any one of (1) to (7).
(10) In a process cartridge that is selected from an electrostatic latent image carrier, a charging unit, a developing unit, and a cleaning unit, and that integrally supports at least the developing unit and is detachable from the image forming apparatus main body, the developing unit includes: A process cartridge which holds toner and is the oilless toner according to any one of (1) to (7).

  The oilless toner containing the binder resin, wax, and colorant according to claim 1, wherein the binder resin contains a cyclic olefin resin and polyvinyl acetal. By mixing, it is possible to prevent an extremely low viscosity and occurrence of tackiness derived from the cyclic olefin resin, to reduce energy consumption due to a wide non-offset temperature range, and to improve color image characteristics.

  The toner according to claim 1, wherein the hydroxyl group concentration mol% of the polyvinyl acetal of claim 2 is 20 or more and 35 or less, and good oilless characteristics can be obtained.

  3. The toner according to claim 1, wherein the mixing ratio of the cyclic olefin resin, the cyclic olefin resin, and the polyvinyl acetal according to claim 3 is 100: 10 to 10: 100. Within the ratio, it is possible to prevent the occurrence of extreme viscosity reduction and the occurrence of stickiness, and good oilless characteristics can be obtained.

  The toner according to any one of claims 1 to 3, wherein the mixing ratio of the wax to the binder resin according to claim 4 is 100: 50 to 100: 5. And the occurrence of tackiness can be prevented, and a toner having no offset can be obtained.

  5. The toner according to claim 1, wherein the penetration of the wax contained in claim 5 at 25 ° C. is 40 or less. The higher the hardness of the wax, the better. Performance can be obtained.

  The type of wax contained in claim 6 is one of carnauba, candelilla, montan, rice, esparto, caster ester, or acid wax, according to any one of claims 1 to 5. According to the described toner, it is possible to prevent an extremely low viscosity and occurrence of adhesiveness, and a toner having no offset can be obtained.

  The toner according to claim 6, wherein paraffin, olefin, microcrystalline, or these oxidized waxes are added as the second wax component of claim 7 in an amount of 5 to 35% by weight of the total wax components. Good performance without offset can be obtained.

  According to the developer comprising the oilless toner according to any one of claims 1 to 7 and the carrier, a high-quality image without image unevenness can be obtained.

  10. The image forming method according to claim 9, comprising at least a charging step, an exposure step, a developing step, a transferring step, and a fixing step, wherein the developing step holds toner and the toner. According to the image forming method using the oilless toner according to any one of claims 1 to 7, a high-quality image can be obtained over a long period of time.

11. The process cartridge according to claim 10, which is selected from an electrostatic latent image carrier, a charging unit, a developing unit, and a cleaning unit, and supports at least the developing unit integrally and is detachable from the main body of the image forming apparatus. According to the process cartridge, the toner is held and the toner is the electrostatic charge image developing toner according to any one of claims 1 to 7, and the toner can be attached to and detached from the image forming apparatus. In addition, since the oilless toner of the present invention is included, a high quality image can be formed over a long period of time.

Embodiments of the present invention will be described below.
(Oilless toner according to the present invention)
As the cyclic olefin resin that is a constituent component of the toner of the present invention, all cyclic olefins that fall into the category of so-called conventional petroleum resins can be used in the present invention. For example, JP-A-2000-066438 discloses details. The cyclic olefin resin obtained as described below can be preferably used.

  The olefin resin having a cyclic structure as the binder resin is preferably a lower alkene having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, for example, an α-olefin such as ethylene, propylene, butylene, etc. Olefin) and cyclic and / or polycyclic compounds having 3 to 17, preferably 5 to 12 carbon atoms having at least one double bond such as norbornene, tetracyclododecene, dicyclopentadiene, cyclohexene, etc. A cyclic (cyclo) olefin), particularly preferably a copolymer with norbornene or tetracyclododecene, which is colorless and transparent and has a high light transmittance.

  This cyclic olefin resin is, for example, an olefin obtained by a polymerization method using a metallocene catalyst, a Ziegler catalyst and a metathese polymerization, that is, a catalyst for double bond opening and ring-opening polymerization reaction. Based polymer. Examples of the synthesis of the olefin polymer having this structure include JP-A-5-339327, JP-A-5-9223, JP-A-6-271628, European Patent Application Publication (A) No. 203799, No. 407870, No. 283164, No. 156464, JP-A-7-253315, and the like.

  According to these, one or more monomers of the above cyclic olefin are optionally combined with one of the above acyclic olefin-monomers and -78 to 150 ° C., preferably 20 to 80 ° C. and a pressure of 0.01 to 64 bar and an aluminoxane. It is obtained by polymerizing in the presence of a catalyst comprising at least one kind of a co-catalyst such as zirconium or hafnium. Other useful polymers are described in European Patent Application (A) 317262, and hydrogenated polymers and copolymers of styrene and dicyclopentadiene can also be used.

  Since the metallocene catalyst is activated in a state where the metallocene catalyst is dissolved in the inert hydrocarbon of the aliphatic or aromatic hydrocarbon, for example, the metallocene catalyst is dissolved in toluene, and the preliminary activity and reaction are performed in a solvent. The important properties of an olefin polymer having a cyclic structure are softening point, melting point, viscosity, dielectric properties, non-offset temperature range and transparency. These can be advantageously adjusted by the choice of monomer / comonomer, ie intermonomer ratio in the copolymer, molecular weight, molecular weight distribution, hybrid polymer, blends and additives.

  In addition, the reaction charge molar ratio of the acyclic olefin and the cyclic olefin can be varied in a wide range depending on the olefin polymer having a target cyclic structure, preferably 50: 1 to 1:50, particularly preferably. Is adjusted from 20: 1 to 1:20.

  For example, when the copolymer component is charged with a total of two compounds, ethylene as an acyclic olefin and norbornene as a cyclic olefin, the glass transition point (Tg) of an olefin polymer having a cyclic structure as a reaction product. Is greatly affected by these charging ratios, and when the norbornene content is increased, Tg tends to increase. For example, when the content of norbornene is about 60% by weight, Tg is about 60 to 70 ° C. Physical properties such as number average molecular weight are adjusted as known from the literature.

  In the present invention, the cyclic olefin resin is an olefin polymer having a cyclic structure which is colorless and transparent and has a high light transmittance. The following low viscosity (low molecular weight) polymer or polymer fraction (a) and high viscosity ( High molecular weight) polymer or polymer fraction (b) is preferred. That is, the olefin polymer having a cyclic structure may be a mixture of the polymer (a) and the polymer (b), or a polymer having a number average molecular weight of less than 7500 with one molecular weight distribution in the peak. Having a fraction and a polymer fraction having a number average molecular weight of 7500 or more, or having two or more peaks in the molecular weight distribution, and a polymer fraction having at least one of them has a number average molecular weight of less than 7500 The polymer fraction having other peaks may have a number average molecular weight of 7500 or more.

  The olefin polymer having a cyclic structure is composed of a low viscosity (low molecular weight) polymer or polymer fraction (a) and a high viscosity (high molecular weight) polymer or polymer fraction (b). This is because the non-offset temperature range extends to both the high temperature side and the low temperature side, so that the toner fixability at high speed copying is improved and the fixability at low temperature and low pressure is simultaneously improved.

  The polymer or polymer fraction (a) (hereinafter referred to as component a) has a number average molecular weight measured by GPC (gel permeation chromatography) in terms of polyethylene, and the number average molecular weight is less than 7,500, preferably 1, 000 to less than 7,500, more preferably less than 2,000 to less than 7,500; weight average molecular weight less than 15,000, preferably less than 1,000 to 15,000, more preferably less than 4,000 to 15,000 ; Intrinsic viscosity (iv; intrinsic viscosity at 135 ° C. when 1.0 g of the polymer is uniformly dissolved in 100 mL of decalin) is less than 0.25 dl / g; glass transition point (Tg) is preferably 70 It is less than ℃.

  The polymer or polymer fraction (b) (hereinafter referred to as component b) has a number average molecular weight of 7,500 or more, preferably 7,500 to 50,000; a weight average molecular weight of 15,000 or more, preferably 15, 000-500,000; intrinsic viscosity (iv) is 0.25 dl / g or more.

  Furthermore, it is preferable that the content of component b is less than 50% by weight, preferably 5 to 35% by weight of the entire binder resin. Component b imparts a structural viscosity to the toner, thereby improving the anti-offset effect and adhesion to a substrate to be copied such as paper or film. However, when the content is 50% by weight or more, the uniform kneading property is extremely high. The toner performance decreases and the toner performance is hindered. That is, it becomes difficult to obtain a high-quality, that is, a clear image having high fixing strength and excellent heat response, or it is technically difficult to obtain a particle size necessary for the toner due to a decrease in mechanical grindability.

  Here, the polymer or polymer fraction is a polymer component before mixing when the olefin polymer having a cyclic structure is composed of a mixture of different components such as various number average molecular weights, In other cases, it refers to a polymer segment obtained by fractionating the final synthesized product by an appropriate means such as GPC. Here, when these polymer fractions are monodispersed or close to monodispersed, the number average molecular weight (Mn) of 7500 corresponds to the weight average molecular weight (Mw) of about 15000.

  The low-viscosity component a constituting the olefin polymer having a cyclic structure contributes to widen the non-offset temperature range to the low temperature side, and conversely the high-viscosity component b contributes to widen to the high temperature side. In order to more effectively expand the non-offset temperature range to the high temperature side, the presence of a high-viscosity component b having a number average molecular weight of 20000 or more is preferable. When the total amount of the binder resin is 100 parts by weight, the contents of components a and b constituting the olefin polymer are each preferably 0.5 parts by weight or more, particularly preferably 5 to 100 parts by weight. In both cases, if the amount is less than 0.5 parts by weight, a practical wide non-offset temperature range tends to be hardly obtained.

  The high viscosity (high molecular weight) / low viscosity (low molecular weight) of the olefin polymer having a cyclic structure has the number average molecular weight (Mn), the weight average molecular weight (Mw), and the intrinsic viscosity (iv) as described above. Since Mw / Mn indicating the degree of dispersion of the molecular weight distribution is as small as 1 to 2.5, a toner having a fast heat response and a high fixing strength can be produced because it is monodisperse or close to monodispersion. In addition to being able to be fixed, it contributes to storage stability of toner, spent toner properties, uniformity of charge amount distribution, and electrical stability showing constant charge / discharge efficiency. Here, in particular, when the low-viscosity polymer or polymer fraction is monodispersed or close to monodispersed, it is preferable because it exhibits excellent heat response as a so-called toner such as instantaneous melting and solidification behavior.

  Further, since the olefin polymer having a cyclic structure is colorless and transparent and has high light transmittance, for example, after adding “Permanentorubin F6B” (manufactured by Clariant) as an azo pigment and kneading sufficiently. Since it was confirmed that the sheet formed by the press machine is also excellent in transparency, it can be sufficiently applied to color toners. In addition, the olefin polymer has a very low heat of fusion as measured by the DSC method (differential scanning calorimetry), and it can be expected that the energy consumption for fixing the toner is greatly reduced.

  By modifying the olefin polymer having a cyclic structure, the following toner can be improved. That is, by introducing a carboxyl group into an olefin polymer having a cyclic structure, the compatibility with other resins can be improved, and the dispersibility of the pigment in the toner can be improved. By introducing such a carboxyl group, it is possible to improve the adhesiveness of the toner to a substrate to be copied such as paper or film and to increase the fixing property.

  As a method for introducing a carboxyl group, a two-step reaction method is preferred, in which an olefin polymer having a cyclic structure is first prepared and then a carboxyl group is introduced. There are at least two methods for introducing this carboxyl group. One is to oxidize an alkyl group such as a methyl group at the end of the polymer by a melt air oxidation method to form a carboxyl group. However, in this method, in the case of an olefin polymer having a cyclic structure synthesized with a metallocene catalyst, it is difficult to introduce many carboxyl groups because there is almost no branching.

  Specifically, the maleic anhydride, acrylic acid or acrylic acid is used so that the graft ratio is preferably 1 to 5% by weight, particularly preferably 3 to 5% by weight with respect to the olefin polymer having a cyclic structure. A carboxyl group is introduced by graft polymerization of methacrylic acid using a peroxide such as t-butanol peroxide as an initiator. If the amount is less than 1% by weight, the effect of improving the compatibility described above is not sufficient. On the other hand, if the amount exceeds 5% by weight, intermolecular crosslinking occurs in the olefin polymer to increase the molecular weight, and the kneadability and grindability are impractical. In addition, since it exhibits extreme yellowing and devitrification, it tends to be unsuitable for color toners that require colorless transparency. A similar improvement can be realized by introducing a hydroxyl group or an amino group by a known method.

  Further, in order to improve the fixing property of the toner, a crosslinked structure can be introduced into the olefin polymer having a cyclic structure. One method for introducing this crosslinked structure is to add a diene monomer such as cyclopentadiene, cyclohexadiene, norbornadiene, tetracyclododecadiene, butadiene, etc. together with acyclic olefin and cyclic olefin during polymerization of the olefin polymer. By original copolymerization. By this method, the olefin polymer has a terminal that shows activity without a crosslinking agent, and has a crosslinked structure by a known chemical reaction such as oxidation or epoxidation, or by adding a crosslinking agent, and is functionalized. Is done. As another method, a metal such as zinc, copper, or calcium is added to the olefin polymer having a cyclic structure into which the carboxyl group is introduced, and then mixed and melted with a screw or the like, and the metal is finely divided into the polymer. It is also possible to give a cross-linked structure by dispersing in an ionomer.

  The ionomer technology itself discloses ethylene terpolymers containing carboxyl groups that can be partially or fully neutralized to form divalent metal salts, eg, for the purpose of toughness (US Pat. No. 4,693,494). No. 6-500348 discloses, for the same purpose, a polyester resin molded article containing an ionomer of an unsaturated carboxylic acid containing about 20 to 80% of the carboxylic acid group of zinc, cobalt, nickel. Also reported are those neutralized with aluminum or copper (II).

  As the cyclic olefin resin obtained as described above, for example, a cyclic olefin resin manufactured by Ticona Gesellshaft Mitt Beschlenktel Huffung can be used.

In the present invention, by further mixing polyvinyl acetal in a system in which a cyclic olefin resin and a wax are mixed, it is possible to prevent an extreme decrease in viscosity and occurrence of tackiness.
The hypothesis of this phenomenon is as follows. In general, polyvinyl acetal is obtained by using polyvinyl alcohol and alkyl aldehyde as starting materials, and the hydroxyl group of polyvinyl alcohol reacts with alkyl aldehyde to acetalize, but all hydroxyl groups may be left as hydroxyl groups without acetalization. it can. The molecular structure of the acetalized portion is considered to have low polarity and high compatibility with the wax. On the other hand, the remaining hydroxyl group without acetalization shows high polarity. As a result, the polyvinyl acetal has a portion that is completely compatible with the wax and a portion that is not. This appears as a difference from the cyclic olefin resin, and it is considered that there is no extreme decrease in viscosity or occurrence of tackiness. That is, by mixing the cyclic olefin resin and the polyvinyl acetal, oilless properties can be obtained due to the incomplete compatibility of the polyvinyl acetal. That is, during the fixing, the wax forms a minute oil state between the fixing roller and the toner, and the oil-less property of the toner can be exhibited.

  The hydroxyl group concentration mol% of polyvinyl acetal mixed with the cyclic olefin resin can be calculated from the measurement result of JIS K0070 pyridine-acetyl chloride method. As a result of mixing a polyolefin and a polyvinyl acetal having various hydroxyl group concentrations of mol% to form a toner, it was found that the hydroxyl group concentration of the polyvinyl acetal is preferably 20 to 35 mol%. When the hydroxyl group concentration is lower than 20 mol%, the polarity of the polyvinyl acetal is too low and the wax becomes easily compatible, and the expected release effect by the wax cannot be obtained. On the other hand, when the hydroxyl group concentration of polyvinyl acetal is higher than 35 mol%, the polarity is too high, the compatibility with the cyclic polyolefin is extremely deteriorated to cause dispersion failure, and the expected release effect by the wax is not exhibited.

  Polyvinyl acetal can be produced by a known method. An example of the production method is shown below. Alkyl aldehyde is added to polyvinyl alcohol to acetalize the hydroxyl group, and it is washed and dried to obtain polyvinyl acetal.

  As a result of actually mixing the toner at various ratios to form a toner, the mixing ratio (mass basis) of the cyclic olefin resin and the polyvinyl acetal may be 100: 10 to 10: 100, preferably 100: 20 to 20: 100. Further, it has been found that 100: 30 to 30: 100 is more preferable, and 100: 40 to 40: 100 is still more preferable.

  In addition, when the mixing ratio (mass basis) of the binder resin and the wax is 100: 50 to 100: 5, desired performance is obtained, preferably 100: 40 to 100: 10, more preferably 100: 30 to 100. : 15 found good. If the composition of the wax exceeds 100: 50, wax separation occurs during kneading, and uniform raw material dispersion cannot be obtained. On the other hand, when the composition of the wax is less than 100: 5, sufficient releasability cannot be obtained.

  In general, it has been found that the wax should have a higher hardness, and the penetration at 25 ° C. should be 40 or less, preferably 20 or less, more preferably 15 or less. In addition, the penetration of wax can be measured by a method defined in JIS K2335. The wax preferably contains at least one of esters and acid waxes such as carnauba, candelilla, montan, rice, esparto, and caster. In addition, the fluidity of a toner containing a large amount of wax tends to be poor, but by blending paraffin, polymerized olefin, or microcrystalline wax as the second component, slipping between toner particles tends to be improved. It has been found that the ratio of the second wax component contained in the wax may be 5 to 35% by weight.

  The toner according to the present invention may contain a subresin. Examples of sub-resins include homopolymers of styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene and the like; and styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers. Polymer, styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methacrylic copolymer Acid methyl copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer Coalescence, styrene-butadiene copolymer , Styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, and other styrene copolymers; polymethyl methacrylate, polybutyl methacrylate, Polyvinyl chloride, polyvinyl acetate, polyester, polyurethane, polyamide, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, modified fiber resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum Resins, chlorinated paraffins and the like can be mentioned, and these can be used alone or in combination, but are not particularly limited thereto.

  In the toner of the present invention, a charge control agent can be used as necessary, and it is desirable that the toner is uniformly present on the surface of the toner particles. The charge control agent is not particularly limited and can be appropriately selected from known ones according to the purpose. However, when a colored material is used, the color tone of the image formed by the toner may change, and thus the color control agent is colorless or white. For example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, simple substances of phosphorus or the like Examples thereof include a compound, a simple substance of tungsten or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, and a metal salt of a salicylic acid derivative. These may be used individually by 1 type and may use 2 or more types together.

  The colorant used in the toner of the present invention is not particularly limited and can be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa Yellow (10G, 5G, G), Cadmium Yellow, Yellow Iron Oxide, Ocher, Yellow Lead, Titanium Yellow, Polyazo Yellow, Oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Red, Lead Red, Cado Muum Red, Cadmium Mercury Red, Antimon Zhu, Permane Tread 4R, Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Rake, rhodamine rake B, rhodamine rake Y, alizarin rake, thioindigo red B, thioy Zigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc Green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green Gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon, and the like. These may be used individually by 1 type and may use 2 or more types together.

  In the toner of the present invention, an external additive can be attached to the toner particle surface for the purpose of improving powder fluidity and adjusting charging characteristics. The external additive is not particularly limited and may be appropriately selected from known ones according to the purpose. Examples thereof include inorganic fine particles and organic fine particles, but inorganic fine particles are particularly preferable. It is preferable to add at least one external additive, and it is more preferable to add 1 to 3 types. For example, as inorganic fine particles, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica , Wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and those hydrophobized Etc. Among these, hydrophobized silica and titanium oxide are particularly preferable. The organic fine particles are not particularly limited and can be appropriately selected depending on the purpose. For example, polystyrene, methacrylic acid ester or acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization can be used. Examples thereof include polycondensation systems such as coalescence, silicone, benzoguanamine, and nylon, and polymer particles using a thermosetting resin.

<Developer>
When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier. The carrier to toner content ratio in the developer is 1 to 10 weights of toner with respect to 100 parts by weight of carrier. Part is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride And fluoro such as terpolymers of non-fluoride monomers including, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. If the average particle diameter is larger than 1 μm, it may be difficult to control electric resistance.

<Image forming method>
The toner for developing an electrostatic charge image of the present invention can use an image forming method by an image forming apparatus having a configuration as illustrated in FIG. Here, an embodiment applied to the electrophotographic image forming apparatus 100 will be described. The image forming apparatus 100 forms a color image by arranging four process cartridges 1 in parallel in the moving direction of the electrostatic latent image carrier 3. Further, the conveying belt 106a in the transfer device 106 is configured to endlessly move by being stretched around four support rollers 106b, 106c, 106d, and 106e. The toner images on the process cartridges 1Y, 1C, 1M, and 1K using four color toners are transferred onto the transfer paper conveyed on the conveying belt 106a so as to overlap each other by the electrostatic transfer method. The electrostatic transfer method employs a configuration using a transfer roller 106e. Specifically, the transfer rollers 106bY, 106bC, 106bM, and 106bK as the transfer devices 106 are arranged on the back surface of the portion of the conveyance belt 106a that contacts the process cartridges 1Y, 1C, 1M, and 1K, respectively. Here, a transfer region is formed by the portion of the conveyor belt 106 a pressed by the transfer roller 106 b and the electrostatic latent image carrier 3. When the toner images on the process cartridges 1Y, 1C, 1M, and 1K are transferred onto the transfer paper on the conveyance belt 106a, a positive polarity bias is applied to the transfer roller 106e. As a result, a transfer electric field is formed in each primary transfer area, and the toner image on the electrostatic latent image carrier 3 of each process cartridge 1 is electrostatically transferred onto the transfer paper that is sent at a predetermined timing. Attached and transferred. A belt cleaning device for removing toner remaining on the surface of the conveyor belt 106a may be provided. This transfer paper is accommodated in a paper feed cassette 109 and is conveyed to a registration roller pair 109b by a pickup roller 109a and the like. The toner image superimposed on the transfer paper on the conveyance belt 106a is conveyed to the fixing device 108 and fixed by heat and pressure, and is discharged out of the image forming apparatus 100 by the discharge roller 120 and discharged. Placed on a paper tray.

<Process cartridge>
As the electrostatic charge image developing toner of the present invention, a process cartridge having a configuration as illustrated in FIG. 2 can be used. In the present invention, a plurality of components such as an electrostatic latent image carrier, a charging unit, a developing unit, and a cleaning unit are integrally coupled as a process cartridge, and the process cartridge is configured as a copying machine or a printer. It is configured to be detachable from the main body of the image forming apparatus. The process cartridge shown in FIG. 2 includes an electrostatic latent image carrier 101, a charging unit 102, a developing unit 104, and a cleaning unit 107. In operation, the electrostatic latent image carrier is driven to rotate at a predetermined peripheral speed. The electrostatic latent image carrier is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging means during the rotation process, and then the image exposure light from the image exposure means 103 such as slit exposure or laser beam scanning exposure. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the electrostatic latent image carrier, and the formed electrostatic latent images are then developed with toner by the developing means. Then, the transfer unit 108 sequentially transfers the image onto the transfer material 105 fed in synchronization with the rotation of the electrostatic latent image carrier between the electrostatic latent image carrier and the transfer unit. The transfer material that has received the image transfer is separated from the electrostatic latent image carrier, introduced into the image fixing means, and fixed, and printed out as a copy (copy). The surface of the electrostatic latent image carrier after the image transfer is cleaned by removing the transfer residual toner by the cleaning means, and after being further discharged, it is repeatedly used for image formation.

  Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples. In the following description, “parts by weight” is expressed only as “parts”.

Examples 1-7
The method for producing the toner is as follows. The raw materials weighed in accordance with the formulation shown in Table 1 were thoroughly mixed using a Henschel mixer manufactured by Mitsui Mining Co., Ltd., then continuously kneaded using a single screw extruder at a screw rotation speed of 100 r / min and a heating temperature of 100 ° C., and then cooled. The kneaded material rolled into a plate by a roll was pulverized and classified. The volume average particle diameter of the toner is pulverized and classified so that the result of measuring the particle diameter with a particle size measuring device (“Coulter Counter TAII”; Coulter Electronics Co., Ltd.) with an aperture diameter of 100 μm is 9.0 ± 0.3 μm. Adjusted. Thereafter, surface hydrophobized silica (volume average particle size 0.03 μm) whose volume average particle size was confirmed by Nikkiso Microtrack HRA, and surface hydrophobized titanium oxide (volume average particle size 0.08 μm) Was added by 0.5% by weight to the toner and mixed with a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to adhere the surface-hydrophobized silica and titanium oxide to the toner particle surfaces. Further, this was passed through a sieve having an opening of 38 μm to obtain a toner. In addition, the molecular weight of the raw material is Tosoh Corporation Gel Permeation Chromatography HLC-8220GPC type device, TSKgel SuperHZM-H is used for the column, THF solvent is used, and the polystyrene concentration is 0.15 wt% in terms of polystyrene. It was measured.

<Fixability evaluation>
As a fixing property evaluation method, a fixing unit of Imagio Neo C455 manufactured by Ricoh Co., Ltd. was taken out and remodeled so that it can be operated independently, and used as a fixing property evaluation machine. The paper on which the toner has been uniformly developed to 0.85 mg / cm ^{2 in} advance is passed at a fixing roller temperature of 200 ° C., 220 ° C. (high temperature fixing conditions), and 140 ° C. (low temperature fixing conditions). The presence or absence was confirmed. The results are shown in Table 1.

表中の内容の補足
環状オレフィン樹脂： ティコナ製 ＴＯＰＡＳ ＴＢ
Ｍｗ７５００とＭｗ７５００００の混合品
ポリビニルアセタール（１）： 水酸基 ３０ｍｏｌ％ Ｍｗ５００００
ポリビニルアセタール（２）： 水酸基 ２２ｍｏｌ％ Ｍｗ５００００
ポリビニルアセタール（３）： 水酸基 ３５ｍｏｌ％ Ｍｗ５００００
ポリビニルアセタール（４）： 水酸基 １５ｍｏｌ％ Ｍｗ５００００
ポリビニルアセタール（５）： 水酸基 ４０ｍｏｌ％ Ｍｗ５００００
カルナウバワックス： 針入度 ２（２５℃）
パラフィンワックス： 針入度 ３（２５℃）
ＣＣＡ： サリチル酸ジルコニウム誘導体
高温定着性評価： ◎・・・２２０℃、２００℃共にオフセット無し
○・・・２００℃はオフセット無し、２２０℃でオフセット発生
×・・・２２０℃、２００℃共にオフセット発生
低温定着性評価： ○・・・１４０℃でオフセット無し
×・・・１４０℃でオフセット発生

Supplementary cyclic olefin resin with the contents in the table: TOPAS TB manufactured by Ticona
Mixture of Mw7500 and Mw750,000 polyvinyl acetal (1): hydroxyl group 30 mol% Mw50000
Polyvinyl acetal (2): hydroxyl group 22 mol% Mw 50000
Polyvinyl acetal (3): hydroxyl group 35 mol% Mw 50000
Polyvinyl acetal (4): hydroxyl group 15 mol% Mw 50000
Polyvinyl acetal (5): hydroxyl group 40 mol% Mw 50000
Carnauba wax: penetration 2 (25 ° C)
Paraffin wax: penetration 3 (25 ° C)
CCA: Zirconium salicylate derivative high temperature fixability evaluation: ◎ ・ ・ ・ No offset at 220 ℃ and 200 ℃
○ ... No offset at 200 ° C, offset generated at 220 ° C
× ・ ・ ・ Offset occurrence at 220 ° C and 200 ° C Low temperature fixability evaluation: ○ ・ ・ ・ No offset at 140 ° C
× ・ ・ ・ Offset occurs at 140 ℃

Comparative Examples 1-2
A toner was prepared and evaluated in the same manner as in the example except that the formulation shown in Table 2 was used.

  As shown in the Examples, a toner having good offset resistance at both high and low temperatures can be obtained within the range defined by the present invention. Further, as shown in the comparative example, it is apparent that the toner having a prescription outside the specified range of the present invention has poor offset resistance under both high temperature conditions and low temperature conditions.

It is a figure for demonstrating the image forming method of this invention. It is a figure which shows an example of the process cartridge of this invention.

Claims (10)

  An oilless toner containing at least a binder resin, a wax, and a colorant, wherein the binder resin contains a cyclic olefin resin and polyvinyl acetal.   2. The oilless toner according to claim 1, wherein a mol% of a hydroxyl group in the polyvinyl acetal is 20 or more and 35 or less.   3. The oilless toner according to claim 1, wherein a mixing ratio of the cyclic olefin resin and the polyvinyl acetal is 100: 10 to 10: 100.   The oilless toner according to any one of claims 1 to 3, wherein a mixing ratio of the binder resin and the wax is 100: 50 to 100: 5.   The oilless toner according to any one of claims 1 to 4, wherein the penetration of the wax at 25 ° C is 40 or less.   6. The oilless toner according to claim 1, wherein the wax contains at least one of carnauba, candelilla, montan, rice, esparto, caster ester, and acid wax. .   The wax contains at least one of paraffin, olefin, microcrystalline and these oxidized waxes as the second wax component, and the ratio of the second wax component to the total wax is 5 to 35% by weight. The oilless toner according to claim 6.   A developer using the oilless toner according to any one of claims 1 to 7.   In an image forming method comprising an electrostatic charge image carrier, at least a charging step, an exposure step, a development step, a transfer step, and a fixing step, the development step holds toner, and the toner is claimed in claim 1. 8. An image forming method using the oilless toner according to any one of items 7 to 7.   In a process cartridge that is selected from an electrostatic latent image carrier, a charging unit, a developing unit, and a cleaning unit and that supports at least the developing unit and is detachable from the image forming apparatus main body, the developing unit holds toner. A process cartridge, wherein the toner is an oilless toner according to any one of claims 1 to 7.

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