JP2009003025A - Image fixing method, image forming method, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image fixing method, an image forming method, and an image forming apparatus capable of reducing an application amount of oil even when various recording media are used and capable of achieving both the low-temperature fixability and hot offset resistance. <P>SOLUTION: In the image fixing method, paper P is held between a heating roller 700 capable of abutting against an unfixed image formed on the paper P and a pressure roller 701 capable of brought into press-contact with the heating roller 700 to fix the unfixed image; the pressure of holding the paper P is controlled in accordance with the type of the paper P; the unfixed image is formed by using toner; and the toner includes an amorphous polyester resin containing inorganic tin (II) compound, wherein tanδ at a measurement temperature of 130°C and a frequency of 1 Hz or more and ≤10 Hz is ≥1.1 and ≤2.0, and wherein the ratio of tanδ at the measurement temperature of 130°C and at the frequency of 1 Hz to tanδ at the measurement temperature of 130°C and at the frequency of 10 Hz is ≥1.0 and ≤1.8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image fixing method, an image forming method, and an image forming apparatus.

  Since the heating roller used in the fixing device is a member that consumes a lot of power, in recent years, a toner having a low melting point has been used for the purpose of suppressing power consumption. In this case, power consumption can be suppressed regardless of the type of recording medium introduced into the fixing device, but hot offset tends to occur at a preset fixing temperature depending on the type of recording medium. There's a problem. The main recording medium used in image forming apparatuses such as copiers and printers is plain paper. In general, however, the cellulose content is higher than that of plain paper in order to improve characteristics such as light transmittance. Racing paper may be used as a recording medium. As described above, when a toner having a low melting point is used for a plain paper having different characteristics as a recording medium, in this case, light transmittance, the fixing temperature is unsatisfactory in order to prevent wrinkling of the tracing paper. May be sufficient. For this reason, although the fixing temperature of the tracing paper is set higher than the fixing temperature of plain paper using toner having a low melting point, hot offset is likely to occur.

  On the other hand, the oil application roller not only suppresses the occurrence of offset, but can also have a function of removing foreign matters such as paper dust adhering to the heating roller. In this case, when the oil application roller contacts the heating roller, the same function as a known cleaning blade is exhibited by maintaining the oil application roller in a state not following the heating roller. However, in a configuration in which a part of the peripheral surface is always in contact with the heating roller, there is a problem that foreign matter accumulates on a part of the peripheral surface in contact with the heating roller. As a result, the foreign matter may transfer to the heating roller and adhere to the recording medium.

Patent Document 1 includes a heating roller that can contact an unfixed toner image carried on a recording medium, and a pressure roller that contacts and abuts the unfixed toner image, and fixes the unfixed toner image on the recording medium. In the fixing device, the heating roller and the pressure roller can change the clamping pressure to the recording medium according to the amount of heat required for the recording medium, and can contact and separate from the heating roller according to the type of the recording medium. A configuration is disclosed in which an application roller for applying a lubricant for preventing offset is provided. However, depending on the type of recording medium, there is a problem that unfixed toner cleaned by the application roller is allowed to cool and fall as a lump.
JP 2001-215842 A

  In view of the above-described problems of the prior art, the present invention can reduce the amount of oil applied and achieve both low temperature fixability and hot offset resistance even when using various recording media. It is an object to provide a method, an image forming method, and an image forming apparatus.

  The invention according to claim 1 is a heating roller capable of contacting and heating the unfixed image formed on the recording medium, and a pressure roller capable of being pressed against the heating roller. An image fixing method for fixing an unfixed image by sandwiching a recording medium, wherein the pressure for sandwiching the recording medium is controlled according to the type of the recording medium, and the unfixed image is made of toner. The formed toner has an amorphous polyester resin containing an inorganic tin (II) compound, and tan δ at a measurement temperature of 130 ° C. and a frequency of 1 Hz to 10 Hz is 1.1 to 2.0. A ratio of tan δ at a temperature of 130 ° C. and a frequency of 10 Hz to tan δ at a temperature of 130 ° C. and a frequency of 1 Hz is 1.0 to 1.8. In the specification and claims of the present application, tan δ means the ratio of the loss elastic modulus to the storage elastic modulus.

According to a second aspect of the present invention, in the image fixing method according to the first aspect, the toner has a storage elastic modulus of 1 × 10 ⁴ Pa to 5 × 10 ⁵ Pa at a measurement temperature of 130 ° C. and a frequency of 1 Hz to 10 Hz. It is characterized by the following.

  A third aspect of the present invention is the image fixing method according to the first or second aspect, wherein the toner has a weight average particle size of 3.0 μm or more and 8.0 μm or less, and a weight average particle size relative to the number average particle size. The ratio of diameters is 1.20 or more and 1.40 or less.

  The invention according to claim 4 is the image fixing method according to any one of claims 1 to 3, wherein the toner contains an inorganic tin (II) compound as a catalyst.

（式中、Ｒは、炭素数が２以上２０以下の直鎖状の不飽和脂肪族炭化水素の２価基であり、ｎは、２以上２０以下の整数である。）
で表される構造を有する結晶性ポリエステル樹脂をさらに有することを特徴とする。

(In the formula, R is a divalent group of a linear unsaturated aliphatic hydrocarbon having 2 to 20 carbon atoms, and n is an integer of 2 to 20)
It further has crystalline polyester resin which has a structure denoted by these.

  According to a fifth aspect of the present invention, in the image fixing method according to the fourth aspect, the toner further includes a styrene acrylic resin, and a weight ratio of the styrene acrylic resin to the crystalline polyester resin is 0.00. It is 25 or more and 1 or less.

  According to a sixth aspect of the invention, in the image fixing method according to the fifth aspect, the toner contains the styrene acrylic resin and a hybrid resin having the polyester resin.

  According to a seventh aspect of the present invention, there is provided an image forming method comprising: forming an image using a toner on a recording medium; and using the image fixing method according to any one of the first to sixth aspects, A step of fixing the image;

  According to an eighth aspect of the present invention, in the image forming apparatus, an image forming unit that forms an image using toner on a recording medium and the image fixing method according to any one of the first to sixth aspects are used. The image fixing unit includes an image fixing unit that fixes the image, and the image fixing unit includes a mechanism that controls a pressure for sandwiching the recording medium in accordance with the type of the recording medium.

  According to the present invention, an image fixing method, an image forming method, and an image forming method that can reduce the amount of oil applied and achieve both low temperature fixability and hot offset resistance even when various recording media are used. An apparatus can be provided.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  The image fixing method of the present invention includes a heating roller that is in contact with an unfixed image formed on a recording medium and that can be heated, and a pressure roller that can be in pressure contact with the heating roller. The unfixed image is fixed by nipping, and the pressure for nipping the recording medium is controlled according to the type of the recording medium, and the unfixed image is formed using toner. Further, the toner has, as a catalyst, an amorphous polyester resin containing an inorganic tin (II) compound as a binder resin, and a tan δ (loss relative to storage elastic modulus G ′) at a measurement temperature of 130 ° C. and a frequency of 1 to 10 Hz. (Ratio of elastic modulus G ″) is 1.1 to 2.0, preferably 1.1 to 1.5, and tan δ (10 Hz) / tan δ (1 Hz) at a measurement temperature of 130 ° C. is 1.0 to 1. .8, preferably 1.0 to 1.3. Accordingly, even when the pressure for sandwiching the recording medium is low, or even when the recording medium such as tracing paper is used and the pressure for sandwiching the recording medium is high, the temperature is sufficiently low. Fixability and hot offset resistance can be obtained. Tan δ is measured using a rheometer, and tan δ (1 Hz) and tan δ (10 Hz) mean tan δ at frequencies of 1 Hz and 10 Hz, respectively.

  At this time, the pressure for sandwiching the recording medium corresponds to the frequency when tan δ is measured, and the condition for low pressure for sandwiching the recording medium is the deformation condition in a short time (high speed), that is, the frequency is large. Corresponds to the condition. Further, the condition where the pressure for sandwiching the recording medium is high corresponds to a deformation condition for a long time (low speed), that is, a condition where the frequency is small.

  A polymer melt such as a toner at the time of fixing behaves differently from a glass region, a transition region, a rubber region, and a flow region depending on a deformation speed, that is, a frequency. Therefore, by using the toner having the above-described characteristics, sufficient low-temperature fixability and hot offset resistance can be obtained regardless of whether the pressure for sandwiching the recording medium is high or low.

  If the tan δ at a measurement temperature of 130 ° C. and a frequency of 1 to 10 Hz is less than 1.1, the ratio of the storage elastic modulus G ′ is large, so that it does not melt sufficiently and is advantageous for hot offset resistance. The image is rubbed and peeled off after fixing. Further, when tan δ at a measurement temperature of 130 ° C. and a frequency of 1 to 10 Hz exceeds 2.0, the ratio of the loss elastic modulus G ″ is high, which is advantageous for low-temperature fixability, but disadvantageous for hot offset resistance. The oil application roller is soiled, and the accumulated toner cools and hardens the next day and falls.

  On the other hand, when tan δ (10 Hz) / tan δ (1 Hz) at a measurement temperature of 130 ° C. is less than 1.0, the storage elastic modulus G ′ is large in deformation at high speed, so that the pressure for sandwiching the recording medium is low. Insufficient low-temperature fixability. Further, since the loss elastic modulus G ″ is large in the deformation at a low speed, the hot offset resistance is insufficient under the condition that the pressure for sandwiching the recording medium is high.

  Further, when tan δ (10 Hz) / tan δ (1 Hz) at a measurement temperature of 130 ° C. exceeds 1.8, the variation in loss elastic modulus G ″ is larger than the variation in storage elastic modulus G ′ in the variation in frequency. The hot offset resistance is insufficient in the pressure fluctuation range for sandwiching the recording medium.

  In the present invention, rheological properties are measured using a viscoelasticity measuring device (rheometer) RDA-II type (manufactured by Rheometrics). Specifically, a parallel plate having a diameter of 7.9 mm is used as a measurement jig, and a measurement sample is obtained by heating and melting the toner and molding it into a cylindrical sample having a diameter of about 8 mm and a height of 2 to 5 mm. use. The measurement frequency is 1 to 10 Hz, and the measurement temperature is 130 ° C. Further, the initial value of the measurement strain is set to 0.1%, and the measurement is performed in the automatic measurement mode. The sample extension correction is adjusted in the automatic measurement mode.

  In the present invention, the toner has, as a catalyst, an amorphous polyester resin containing an inorganic tin (II) compound as a binder resin, whereby a toner having such rheological characteristics can be obtained. In general, a highly active organometallic compound is used as a polymerization catalyst for a polyester resin. However, the organometallic compound remains compatible with the polyester resin after the reaction. For this reason, even if it is a non-crosslinked linear polyester resin or a crosslinked non-crystalline polyester resin, a portion where the loss elastic modulus G ″ is locally increased occurs. Tan δ at a measurement temperature of 130 ° C. and a frequency of 1 to 10 Hz exceeds 2.0. In addition, since the inorganic tin (II) compound becomes metal tin or tin oxide after the reaction and is dispersed in the binder resin, a filler effect such as metal crosslinking is obtained, and the loss elastic modulus G ″ is increased. Can be suppressed.

  Examples of the inorganic tin (II) compound include a compound having a Sn-O bond, a compound having a Sn-X (X is a halogen group) bond, and the like, and a compound having a Sn-O bond is preferable.

Examples of the compound having a Sn-O bond include tin (II) octylate, tin (II) oxalate, tin (II) diacetate, tin (II) dioctanoate, tin (II) dilaurate, and tin distearate (II). ), Tin (II) carboxylate having a carboxylic acid residue of 2 to 28 carbon atoms such as tin (II) dioleate; bis (octyloxy) tin (II), bis (lauryloxy) tin (II), bis Dialkoxytin (II) having an alkoxyl group having 2 to 28 carbon atoms such as (stearyloxy) tin (II) and bis (oleyloxy) tin (II); tin oxide (II); tin sulfate (II) Can be mentioned. Examples of the compound having a Sn-X bond include tin (II) halides such as tin (II) chloride and tin (II) bromide. Among these, from the viewpoint of the charge rising effect and catalytic ability, the general formula (R ₁ COO) ₂ Sn
(In the formula, R ₁ is an alkyl or alkenyl group having 5 to 19 carbon atoms.)
Fatty acid tin (II) represented by general formula (R ₂ O) ₂ Sn
(In the formula, R ₂ is an alkyl group or alkenyl group having 6 to 20 carbon atoms.)
Preferred are dialkoxytin (II) and tin (II) oxide (SnO), more preferably the above-mentioned fatty acid tin (II) and tin (II) oxide, tin (II) octylate, tin dioctanoate (II) ), Tin (II) distearate and tin (II) oxide are particularly preferred. A polyester resin containing an inorganic tin (II) compound can be used as a binder resin for toner.

  In the present invention, the toner preferably has a branched amorphous polyester resin that is crosslinked. Such a toner can be produced by crosslinking a curable polyester resin in a kneading step. For this reason, desired tan δ can be obtained by appropriately adjusting the kneading conditions. In order to easily obtain a branched amorphous polyester resin, it is preferable to shorten the molecular chain between the crosslinking points. In order to prevent the molecular chain between the crosslinking points from becoming long, the amount of the crosslinking agent added may be about 20 to 45 mol% with respect to the total amount of the monomers. At this time, in order to reduce the content of the low molecular weight component, the addition amount of the inorganic tin (II) compound is set to 0.2 to 0.5% of the total weight of the monomer, or the charging is divided into two times. First, 30 to 50% by weight of the total addition amount is charged at the first time, and when the target viscosity reaches 65 to 80%, the remaining 50 to 70% by weight is added, and the total amount is 0% of the total weight of the monomers. It is preferable to add 1 to 0.7%.

  In addition, when the toner has a non-crosslinked linear polyester resin, the ratio of the loss elastic modulus G ″ generally increases, so that tan δ at a measurement temperature of 130 ° C. and a frequency of 1 to 10 Hz increases. However, when the weight average molecular weight of the polyester resin exceeds 100,000, molecular chain entanglement occurs and the ratio of the loss elastic modulus G ″ decreases. It should be noted that the low temperature fixability can be further improved by adding a polyester resin having a weight average molecular weight of less than 100,000 within the range where the above-mentioned toner characteristics can be obtained.

  The molecular weight of the resin is measured by using gel permeation chromatography (GPC) with a commercially available monodisperse standard polystyrene as a standard. At this time, measurement is performed at a flow rate of 1.0 ml / min using SHODX RI-71S as a detector, tetrahydrofuran as a solvent, and KF-G + KF-807Lx3 + KF800D as a column. The resin is injected after being diluted to 0.25% by weight with THF.

In the present invention, the toner preferably has a storage elastic modulus G ′ of 1 × 10 ^{4 to} 5 × 10 ⁵ Pa at a measurement temperature of 130 ° C. and a frequency of 1 Hz to 10 Hz, and preferably 1 × 10 ^{5 to} 5 × 10 ⁵ Pa. Is more preferable. As a result, hot offset resistance can be further improved, and contamination of the oil application roller can be suppressed. Further, since the toner has an appropriate elasticity at the time of fixing, the toner is prevented from being completely melted and crushed, and an image with high granularity can be obtained. In order to obtain such a toner, it is preferable to use tin octylate as the inorganic tin (II) compound. Since tin octylate has high reactivity and high uniformity of the structure of the resulting polyester resin, the production of an extremely low molecular weight polyester resin is suppressed, and a polyester resin having a large storage elastic modulus G ′ can be obtained. When inorganic tin (II) compounds other than tin octylate are used, the temperature rise rate at the time of synthesis is lowered to synthesize gently, thereby suppressing the production of extremely low molecular weight polyester resin, and storage modulus G A resin with a large 'is obtained. Further, the catalyst charging method is divided into two stages, and the polyester resin having a high storage elastic modulus G ′ is obtained by charging at the time of monomer charging and when the amount exceeds 15 to 20% of the target viscosity. Since the polyester resin thus obtained has high structure uniformity, the storage elastic modulus G ′ can be prevented from greatly decreasing due to kneading energy. In addition, since the polyester resin obtained using an organometallic compound as a catalyst has low structure uniformity, the storage elastic modulus G ′ is greatly reduced by the energy of kneading. At this time, the reduction of the storage elastic modulus G ′ can be suppressed by reducing the kneading energy, but the dispersibility with other materials is reduced, and image fogging or the like occurs.

  In the present invention, the toner contains an inorganic tin (II) compound as a catalyst.

（式中、Ｒは、炭素数が２〜２０の直鎖状の不飽和脂肪族炭化水素の２価基であり、ｎは、２〜２０の整数である。）
で表される構造を有する結晶性ポリエステル樹脂を、結着樹脂としてさらに有することが好ましい。これにより、低温定着性をさらに向上させることができ、トレーシングペーパー等の各種記録媒体を使用しても、オイル塗布ローラが不要となる。これは、結晶性ポリエステル樹脂がガラス転移温度で結晶転移を起こすと同時に、固体状態から急激に溶融粘度が低下し、非結晶性ポリエステル樹脂では得られない定着性能を発現することができるためである。

(In the formula, R is a divalent group of a linear unsaturated aliphatic hydrocarbon having 2 to 20 carbon atoms, and n is an integer of 2 to 20.)
It is preferable to further have a crystalline polyester resin having a structure represented by As a result, the low-temperature fixability can be further improved, and an oil application roller is not required even when various recording media such as tracing paper are used. This is because the crystalline polyester resin undergoes a crystal transition at the glass transition temperature, and at the same time, the melt viscosity suddenly decreases from the solid state, and can exhibit fixing performance that cannot be obtained with an amorphous polyester resin. .

  The crystalline polyester resin preferably contains 60 to 100 mol% of ester bonds included in the structure represented by the above general formula. In the general formula, R is preferably a divalent group of a linear unsaturated aliphatic hydrocarbon having 2 to 4 carbon atoms, and n is preferably an integer of 2 to 6. The divalent group of the linear unsaturated aliphatic hydrocarbon is derived from a linear unsaturated dicarboxylic acid. Examples of the linear unsaturated dicarboxylic acid include maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, 1,4-n-butene dicarboxylic acid, and the like. Moreover, the functional group in which n methylene groups are linked is derived from a linear aliphatic diol. Specific examples of the linear aliphatic diol include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. Since the crystalline polyester resin is synthesized using a linear unsaturated aliphatic dicarboxylic acid, it becomes easier to form a crystal structure than when an aromatic dicarboxylic acid is used.

  The content of the crystalline polyester resin in the binder resin is usually 5 to 30% by weight, and preferably 10 to 20% by weight. If this content is less than 5% by weight, the effect on low-temperature fixability may be insufficient. On the other hand, if it exceeds 30% by weight, in the kneading process at the time of toner production, the melt viscosity rapidly decreases due to heat generated during kneading, making it difficult to receive mechanical dispersion force and shearing force during kneading. Dispersibility may be reduced. At this time, if the share at the time of kneading is increased to improve the dispersibility, the crystallinity may be broken and the original function may not be obtained.

  The crystalline polyester resin preferably has a softening point of 85 to 140 ° C, more preferably 100 to 140 ° C, and particularly preferably 100 to 130 ° C.

  The crystalline polyester resin also needs to contain an inorganic tin (II) compound. This is because when an organometallic compound is used as a catalyst, organic molecules become non-crystalline sites and crystallinity decreases.

  In addition, when the toner has a crystalline polyester resin, a sudden decrease in viscosity occurs at the time of fixing. Therefore, the binder resin preferably has a crosslinked amorphous polyester resin. The content of the crosslinked amorphous polyester resin in the binder resin is usually 30 to 70% by weight, preferably 40 to 60% by weight. At this time, the content of the crosslinked amorphous polyester resin in the amorphous polyester resin is usually 10 to 40% by weight, and preferably 20 to 30% by weight. This not only improves the low-temperature fixability, but also increases the torque during kneading, thereby improving the dispersibility of the material. At this time, the content of the crosslinked amorphous polyester resin in the toner is preferably 2 to 10% by weight. If this content is less than 2% by weight, the loss elastic modulus G ″ may increase. At this time, the addition amount of carbon black, a magnetic body, and a metal charge control agent can be increased, and the increase in the loss elastic modulus G ″ can be suppressed by the filler effect and the metal crosslinking effect. Further, the fog can be improved by adding a small amount of a magnetic material to the two-component black toner. The amount of magnetic substance added is preferably about 5 to 20% by weight with respect to carbon black. When the amount added exceeds 20% by weight, the developability is lowered and the image density may be lowered. When the amount added is less than 5% by weight, the effect may be insufficient. Further, in the case of a color toner, a similar filler effect can be obtained by adding about 0.5 to 2% by weight of colorless titanium oxide or alumina oxide to the toner during kneading, and the loss modulus G '' Increase can be suppressed. On the other hand, when the content of the crosslinked amorphous polyester resin in the toner exceeds 10% by weight, the storage elastic modulus G ′ may increase.

  Examples of the method for measuring the content of the crosslinked amorphous polyester resin in the toner include a method of extracting with an extraction solvent and measuring the extraction residue in accordance with a normal Soxhlet extraction method. However, even if the toner is directly subjected to Soxhlet extraction, the wax or pigment will block the mesh of the filter paper, and components that are originally filtered as a filtrate remain in the filter paper without being extracted from the filter paper, and are measured as an extraction residue. Therefore, in the present invention, it is calculated from the content of the crosslinked non-crystalline polyester resin in the binder resin measured using a kneaded product obtained by kneading the binder resin under the same conditions as the toner preparation conditions. For this reason, this value does not include crosslinking caused by filler effect or metal crosslinking effect by carbon black, magnetic material, metal charge control agent or the like.

A method for measuring the content of the crosslinked amorphous polyester resin (crosslinking component) in the binder resin will be described below. First, a toner is kneaded with only a binder resin under the same conditions as the preparation conditions to prepare a kneaded product. Next, the kneaded product W ₁ [g] (W ₁ = 0.5 to 1.0) is weighed, and a cylindrical filter paper (for example, No. 86R (manufactured by Toyo Roshi Kaisha)) is put into a Soxhlet extractor, and THF 200 ml. For 10 hours, and the weight W ₂ [g] of the extraction residue after extraction is measured. This extraction residue includes a crosslinked amorphous polyester resin and a crystalline polyester resin that does not dissolve in THF. Next, the extraction solvent is changed to 200 ml of o-dichlorobenzene, the mixture is further extracted for 10 hours while being heated to 130 to 135 ° C. in an oil bath, and the weight W ₃ [g] of the extraction residue after extraction is measured. . At this time, the content of the crosslinking component is expressed by the formula W ₃ / W ₁ × 100 [wt%].
It is requested from.

Moreover, the measuring method of content of the non-crystalline polyester resin (crosslinking component) cross-linked in the non-crystalline polyester resin will be described below. Amorphous polyester resin W ₄ [g] (W ₅ = 0.5 to 1.0) is weighed, and a cylindrical filter paper (for example, No. 86R (manufactured by Toyo Roshi Kaisha)) is put into a Soxhlet extractor and THF 200 ml. For 10 hours, and the weight W ₅ [g] of the extraction residue after extraction is measured. At this time, the content of the crosslinking component is expressed by the formula W ₅ / W ₄ × 100 [wt%].
It is requested from.

  In the present invention, in order to improve the dispersibility of the material in the toner, the toner further includes a styrene acrylic resin as a binder resin, and the weight ratio of the styrene acrylic resin to the crystalline polyester resin is 0.25. It is preferable that it is -1, and 0.40-0.60 are further more preferable. Since the composition of the styrene acrylic resin is different from that of the crystalline polyester resin, the crystalline polyester resin can be finely dispersed while maintaining the crystallinity during melt kneading. If the above weight ratio is less than 0.25, this effect becomes insufficient, and the dispersion diameter of the crystalline polyester resin may increase. The toner permeability may be reduced.

  The styrene acrylic resin is a copolymer of styrene and an acrylic monomer. Examples of the acrylic monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, Heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methacrylic acid Ethoxydiethylene glycol, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydipromethacrylate Lenglycol, phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, methacrylic acid N-vinyl-2-pyrrolidone, methacrylonitrile, methacrylamide, N-methylol methacrylamide, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate, Diacetone acrylamide, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic Butyl, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, glycidyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, acrylic acid Butoxyethyl, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, Benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, Dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2-pyrrolidone acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate Glycidyl acrylate, etc., may be used in combination of two or more. Moreover, it is preferable that content of styrene in all the monomers at the time of synthesize | combining a styrene acrylic resin is 50 to 90 weight%, and 60 to 90 weight% is further more preferable. If the styrene content is less than 50% by weight, the glass transition point of the styrene acrylic resin may be lowered, and the heat resistant storage stability may be insufficient. On the other hand, if the styrene content exceeds 90% by weight, the glass transition point of the styrene acrylic resin may be increased, and the low-temperature fixability may be insufficient.

  Furthermore, in order to improve the permeability of the color toner, the toner preferably contains a styrene acrylic resin and a hybrid resin having a polyester resin. As a result, a color toner having good low-temperature fixability and dispersibility and high transparency can be obtained in a state where the crystalline polyester resin maintains crystallinity. Also, the dispersibility of the wax can be improved.

  In the present invention, the hybrid resin is a resin in which a condensation polymerization type polyester resin and an addition polymerization type styrene acrylic resin are chemically bonded. For this reason, it is preferable to perform polymerization using an amphoteric monomer capable of reacting with both monomers of the resin. Examples of the both reactive monomers include fumaric acid, acrylic acid, methacrylic acid, maleic acid, dimethyl fumarate and the like. The addition amount of the both reactive monomers is usually 1 to 25% by weight, preferably 2 to 10% by weight, based on the raw material monomer of the styrene acrylic resin. If the amount added is less than 1% by weight, the dispersibility of the colorant or charge control agent is lowered, and fogging or the like may occur. If it exceeds 25% by weight, the hybrid resin may be gelled.

  The hybrid resin preferably has an acid value of 15 to 70 mgKOH / g, more preferably 20 to 50 mgKOH / g, and particularly preferably 20 to 30 mgKOH / g. Thereby, the dispersibility of a mold release agent can be improved and it is excellent in low temperature fixability and environmental stability. At this time, since the compatibility between the paper and the resin is improved, the low-temperature fixability can be further improved. When the acid value is less than 15 mgKOH / g, the release agent may be easily released from the polyester resin. When the acid value exceeds 70 mgKOH / g, the influence of moisture in the air becomes large, and the charge amount of the toner is inadequate. May be stable.

  Moreover, the hybrid resin does not need to proceed with both reactions, and the reaction may proceed independently by appropriately selecting each reaction temperature and reaction time. For example, a mixture of a polyester resin raw material monomer, a styrene acrylic resin raw material monomer and a polymerization initiator is dropped into a reaction vessel and mixed in advance. Then, first, after completing the radical polymerization reaction for synthesizing the styrene acrylic resin, the reaction temperature is raised to complete the condensation polymerization reaction for synthesizing the polyester resin. Thereby, two kinds of resins can be effectively dispersed.

  In the present invention, the polyester resin is a polyvalent carboxylic acid or a reactive derivative thereof (acid anhydride, having 1 to 4 carbon atoms) at 150 to 250 ° C. in an inert gas atmosphere in the presence of an inorganic tin (II) compound. Lower alkyl esters, acid halides, etc.) and polyhydric alcohols are obtained by condensation polymerization reaction. In addition, it is preferable that the addition amount of the inorganic tin (II) compound at the time of manufacturing a polyester resin is 0.001-5% with respect to the total weight of the raw material monomer of a polyester resin, 0.05-2% Is more preferable. Therefore, the weight ratio of the inorganic tin (II) compound to the polyester resin is also preferably 0.001 to 5%, and more preferably 0.05 to 2%.

  As the polyvalent carboxylic acid, a divalent carboxylic acid or a trivalent or higher carboxylic acid can be used. Examples of the divalent carboxylic acid include (1) an aliphatic dicarboxylic acid having 2 to 20 carbon atoms such as maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, malonic acid, azelaic acid, mesaconic acid, citraconic acid, and glutaconic acid. Acid; (2) Cycloaliphatic dicarboxylic acid having 8 to 20 carbon atoms such as cyclohexanedicarboxylic acid and methylmedicic acid; (3) Carbon number 8 to 8 such as phthalic acid, isophthalic acid, terephthalic acid, toluenedicarboxylic acid, naphthalenedicarboxylic acid, etc. 20 aromatic dicarboxylic acids; (4) alkyl or alkenyl succinic acids having a hydrocarbon group having 4 to 35 carbon atoms in the side chain such as isododecenyl succinic acid and n-dodecenyl succinic acid; Carboxylic anhydrides and lower alkyl (methyl, butyl, etc.) esters can also be used. Among these, (1), (3), (4) and anhydrides and lower alkyl esters thereof are preferable. (Anhydrous) maleic acid, fumaric acid, isophthalic acid, terephthalic acid, dimethyl terephthalate, n-dodecenyl (anhydrous) More preferred is succinic acid.

  Examples of the trivalent or higher carboxylic acid include (1) 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetrakis (Methylenecarboxyl) aliphatic polycarboxylic acids having 7 to 20 carbon atoms such as methane, 1,2,7,8-octanetetracarboxylic acid; (2) 9 to 9 carbon atoms such as 1,2,4-cyclohexanetricarboxylic acid 20 alicyclic polycarboxylic acids; (3) 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid C9-20 aromatic polycarboxylic acid such as acid, pyromellitic acid, benzophenone tetracarboxylic acid, etc. , Lower alkyl (methyl, butyl, etc.) ester can be used. Of these, (3) and its anhydrides and lower alkyl esters are preferred, but since the gloss and transparency may decrease, the amount used is preferably small.

  As the polyhydric alcohol, a dihydric alcohol or a trihydric or higher alcohol can be used. Examples of the divalent alcohol include (1) ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentane. Alkylene glycols having 2 to 12 carbon atoms such as diol and 1,6-hexanediol; (2) alkylene ether glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol; 3) C6-C30 alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; (4) Bisphenols such as bisphenol A, bisphenol F and bisphenol S; (5) Bisphenol Alkylene oxide class (ethylene oxide, propylene oxide, butylene oxide, etc.) 2-8 mole adducts. Among these, (1) and (5) are preferable, (5) is more preferable, and a good offset resistance is obtained, so that an ethylene oxide and / or propylene oxide 2 to 4 mol adduct of bisphenol A is particularly preferable.

  As trihydric or higher alcohols, (1) sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol , 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, etc. (2) C6-C20 aromatic polyols such as 1,3,5-trihydroxymethylbenzene and the like, and alkylene oxide adducts of trivalent or higher alcohols can also be used. Among these, (1) is preferable, and glycerol, trimethylolpropane and pentaerythritol are more preferable from the viewpoint of inexpensiveness. However, since the gloss and transparency may be lowered, the amount used is preferably small.

  The crystalline polyester resin is a polyvalent carboxylic acid containing a linear unsaturated aliphatic dicarboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.), It can be obtained by polycondensation reaction of a polyhydric alcohol containing a linear aliphatic diol. As the polyvalent carboxylic acid, an unsaturated dicarboxylic acid having a branched chain, a saturated aliphatic dicarboxylic acid, a saturated aliphatic polycarboxylic acid, an aromatic dicarboxylic acid, an aromatic polycarboxylic acid, or the like can be used. The polyvalent carboxylic acid is not particularly limited as long as the polyester resin has crystallinity, but the linear unsaturated aliphatic dicarboxylic acid or a reactive derivative thereof is usually 70 mol% or more, preferably Contains 90 mol% or more.

  In the present invention, the toner can further include a release agent, a colorant and the like in addition to the binder resin.

  Although it does not specifically limit as a mold release agent, It is preferable to use a de-release fatty acid type carnauba wax, a montan wax, and an oxidation rice wax, and may use 2 or more types together. Thereby, dispersibility improves. The carnauba wax is preferably a microcrystal, an acid value of 5 mgKOH / g or less, and a dispersed particle size in the toner of 1 μm or less. The montan wax generally means a montan wax refined from minerals, and is microcrystalline like the carnauba wax, and preferably has an acid value of 5 to 14 mgKOH / g. The oxidized rice wax is obtained by air-oxidizing rice bran wax and preferably has an acid value of 10 to 30 mgKOH / g. Examples of other mold release agents include solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, and low molecular weight polypropylene wax. The release agent before being dispersed in the toner preferably has a volume average particle size of 10 to 800 μm. When the volume average particle size is less than 10 μm, the dispersed particle size in the toner becomes small, the release effect becomes insufficient, and offset may occur. When the volume average particle size exceeds 800 μm, the dispersed particle size in the toner increases, the amount of the release agent deposited on the surface of the toner increases, the fluidity decreases, and the toner adheres to the inside of the developing machine. Sometimes. The volume average particle size is measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.).

  As the colorant, known pigments and dyes capable of obtaining toners such as yellow, magenta, cyan, and black can be used. Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, etc. It is done. Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK and the like. Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, and the like. . Examples of purple pigments include fast violet B and methyl violet lake. Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC. Examples of the green pigment include chrome green, chromium oxide, pigment green B, and malachite green lake. Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides. These pigments may be used in combination of two or more.

  In the present invention, the toner may contain a charge control agent as required. Examples of the charge control agent include nigrosine, an azine dye having an alkyl group having 2 to 16 carbon atoms (see Japanese Patent Publication No. 42-1627), a basic dye (for example, CI Basic Yellow 2 (C.I.). I.41000), C.I.Basic Yellow 3, C.I.Basic Red 1 (C.I.45160), C.I.Basic Red 9 (C.I. 42500), C.I.Basic Violet 1 (C.I. 42535), C.I. Basic Violet 3 (C.I. 42555), C.I.Basic Violet 10 (C.I. 45170), C.I.Basic Violet 14 (C.I. 42510), C.I.Basic Blue 1 (C.I.42025), C.I.Basic Blue 3 (C.I. 51005), C.I.Basic Blue 5 (C.I.42140), C.I.Basic Blue 7 (C.I.42595), C.I.Basic Blue 9 (C.I. 52015), C.I.Basic Blue 24 (C.I.52030), C.I.Basic Blue 25 (C.I.52025), C.I.Basic Blue 26 (C.I. 44045), C.I. I. Basic Green 1 (C.I. 42040), C.I. Basic Green 4 (C.I. 42000), etc.), basic dye lake pigments, C.I. I. Solvent Black 8 (C.I. 26150), quaternary ammonium salts such as benzoylmethylhexadecyl ammonium chloride, decyltrimethyl chloride, dialkyl (eg, dibutyl, dioctyl, etc.) tin compounds, dialkyl (eg, dibutyl, dioctyl, etc.) tin borate Compounds, guanidine derivatives, vinyl polymers having amino groups, polyamine resins such as condensation polymers having amino groups, metal complex salts of monoazo dyes (Japanese Patent Publication Nos. 41-20153, 43-27596, 44) -6397, JP-B-45-26478), salicylic acid (see JP-B-55-42752, JP-B-59-7385), dialkylsalicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Cr And metal complexes such as Fe, sulfonated copper phthalocyanine pigments, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene compounds, and the like. For toners other than black, it is not preferable to use a charge control agent that impairs the target color, and it is preferable to use a metal salt of a white salicylic acid derivative.

  In the present invention, the toner is preferably such that inorganic fine particles such as silica, titanium oxide, alumina, silicon carbide, silicon nitride, boron nitride and the like are externally added to the base particles. Thereby, transferability and durability can be further improved. In general, the presence of wax on the toner surface reduces transferability and durability. However, when the surface of the base particle is covered with an external additive, the contact area decreases, and thus this phenomenon can be suppressed. . As the inorganic fine particles, those whose surface is subjected to a hydrophobic treatment are preferable, and examples thereof include silica subjected to hydrophobic treatment, silica titanium oxide subjected to hydrophobic treatment, and the like. Furthermore, hydrophobized silica and hydrophobized titanium oxide are externally added to the base particles, so that the external addition amount of hydrophobized titanium oxide is larger than that of hydrophobized silica. Thus, a toner having excellent charge stability against humidity can be obtained. As the resin fine particles, fine particles such as polymethyl methacrylate and polystyrene having an average particle size of about 0.05 to 1 μm obtained by a soap-free emulsion polymerization method are preferable.

  Hydrophobizing agents for hydrophobizing inorganic fine particles include dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxysilane, vinyltris (β -Methoxyethoxy) silane, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichloro Silane, dimethylvinylchlorosilane, octyltrichlorosilane, decyltrichlorosilane, nonyltrichlorosilane, (4-t-propylphenyl) trichlorosilane, (4-t-butylphenyl) trichlorosilane, dipentyldichlorosilane, dihexyldichlorosilane, dioctyldi Chlorosilane, dinonyldichlorosilane, didecyldichlorosilane, didodecyldichlorosilane, dihexadecyldichlorosilane, (4-t-butylphenyl) octyldichlorosilane, dioctyldichlorosilane, didecenyldichlorosilane, dinonenyldichlorosilane, Di-2-ethylhexyldichlorosilane, bis (3,3-dimethylpentyl) dichlorosilane, trihexylchlorosilane, trioctylchlorosilane, tridecylchloro Orchid, dioctylmethylchlorosilane, octyldimethylchlorosilane, (4-t-propylphenyl) diethylchlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilazane, hexaphenyldisilazane, hexatolyldi Silazane etc. are mentioned. As other hydrophobic or treating agents, titanate coupling agents and aluminum coupling agents can also be used.

Further, together with inorganic fine particles, silica having a specific surface area of 20 to 50 m ² / g and resin fine particles having an average particle diameter of 1/100 to 1/8 of the average particle diameter of the mother particles are externally added to the mother particles, thereby providing durability. Can be improved. In general, in the process of mixing and stirring the toner and the carrier in the developing device, the inorganic fine particles are embedded in the base particles, but by adding an external additive having a larger particle size than the inorganic fine particles, this is done. Can suppress the phenomenon.

  Further, when such inorganic fine particles and resin fine particles are internally added to the base particles, the pulverization property of the toner can be improved as well as the transferability and durability. Further, by using both the external addition and the internal addition, it is possible to suppress the embedded inorganic fine particles from being embedded, so that excellent transferability can be stably obtained and the durability can be improved.

  Further, a lubricant such as an aliphatic metal salt or polyvinylidene fluoride fine particles may be externally added to the base particles for the purpose of improving cleaning properties.

  In the present invention, in order to obtain better low-temperature fixability, the toner preferably has a weight average particle diameter (D4) of 3.0 to 8.0 μm, more preferably 3.0 to 5.5 μm. . The ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is preferably 1.20 to 1.40, and more preferably 1.20 to 1.35. Accordingly, since the toner particle diameter is sufficiently small for a minute latent image dot of 600 dpi or more, dot reproducibility is excellent. If D4 is less than 3.0 μm, the toner may enter the irregularities of the recording medium, making it difficult for heat to be conducted and lowering the low-temperature fixability. In addition, transfer efficiency may be reduced, and blade cleaning properties may be reduced. On the other hand, if D4 exceeds 8 μm, the amount of heat at the time of fixing may not be conducted instantaneously, or characters and lines may be scattered. If D4 / D1 exceeds 1.40, uniform chargeability may not be obtained, and image fogging may occur. If it is less than 1.20, recycled toner particularly in an apparatus having a recycling system. When the toner is mixed, selective developability occurs, and the recycle toner may stay in the developing machine without being developed, and carrier spent may occur.

  In the present invention, the toner particle size distribution is measured using a Coulter Counter TA-II, a Coulter Multisizer II (manufactured by Coulter Inc.). Hereinafter, the measurement method will be specifically described. First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic solution. Here, the electrolytic solution is an approximately 1 wt% aqueous sodium chloride solution prepared using primary sodium chloride, and, for example, ISOTON-II (manufactured by Coulter, Inc.) can be used. Next, 2 to 20 mg of a measurement sample is added and suspended, and then subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. The weight and number of toners are measured for the dispersion obtained in this way using a 100 μm aperture to obtain a weight distribution and a number distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner are obtained.

  The channel is 2.00 μm or more and less than 2.52 μm; 2.52 μm or more and less than 3.17 μm; 3.17 μm or more and less than 4.00 μm; 4.00 μm or more and less than 5.04 μm; 5.04 μm or more and less than 6.35 μm 6.35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; 25.40 μm or less; 25.40 μm or more and less than 32.00 μm; 13 channels of 32.00 μm or more and less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm are measured.

  In the present invention, a toner production method includes a mixing step of mechanically mixing toner materials containing a binder resin, a release agent, a colorant, and the like, and a melt-kneading step of melting and kneading the mixed toner materials. It is preferable to have a pulverization step of pulverizing the melt-kneaded toner raw material and a classification step of classifying the pulverized toner raw material. Moreover, as a coloring agent, in order to improve the dispersibility of a pigment, what processed the masterbatch of the pigment may be used.

  When mixing the toner raw materials, a known mixer having a rotating blade may be used under normal conditions.

  In addition, when the mixed toner materials are melt-kneaded, a known melt-kneader may be used. Examples of the melt kneader include a batch type twin roll, a Banbury mixer, a continuous type twin screw extruder (for example, KTK type twin screw extruder (manufactured by Kobe Steel), TEM type twin screw extruder (Toshiba Machine Co., Ltd.) Manufactured), twin screw extruder (manufactured by KCK), PCM type twin screw extruder (manufactured by Ikekai Tekko Co., Ltd.), KEX type twin screw extruder (manufactured by Kurimoto Iron Works Co., Ltd.)), continuous single screw kneader ( For example, Ko Nida (made by Buss Co., Ltd.) may be used.

  Next, the melted and kneaded toner material is cooled and then pulverized. At this time, for example, after coarsely pulverizing using a hammer mill, a rotoplex, etc., it is preferable to finely pulverize using a fine pulverizer using a jet stream, a mechanical pulverizer or the like. The pulverized toner raw material preferably has an average particle size of 3 to 15 μm.

  Further, the pulverized toner raw material is classified (particle size adjustment) so as to have a particle size of 2.5 to 20 μm by a wind classifier or the like, whereby base particles are obtained.

  Next, the external additive is externally added to the base particle. The surface of the base particle is coated while the external additive is crushed by mixing and stirring the base particle and the external additive using a mixer. Is done. At this time, the durability can be improved by uniformly and firmly attaching external additives such as inorganic fine particles and resin fine particles to the base particles.

  In the mixing step and the melt-kneading step, particles other than the base particles used in the toner obtained in the pulverization step or the classification step may be reused. The particles other than the base particles used for the toner mean fine particles having a smaller particle diameter and coarse particles having a larger particle diameter than the base particles having a predetermined particle diameter. When such particles are reused in the mixing step or the melt-kneading step, it is preferable to mix them at a weight ratio of 1/99 to 50/50 with respect to the toner raw material.

  The image forming method of the present invention includes a step of forming an image using a toner on a recording medium, and a step of fixing the image formed on the recording medium using the image fixing method of the present invention. As a method of forming an image on a recording medium using toner, a step of forming a latent image on a latent image carrier, a step of developing the formed latent image with toner, and an image developed with toner are recorded. A known method having a step of transferring onto a medium can be used. When a latent image is formed on the latent image carrier, it is preferable that the latent image carrier is uniformly charged and then exposed imagewise. In developing a latent image with toner, it is preferable to use a two-component developer composed of toner and carrier. At this time, the weight ratio of the toner to the carrier is usually 1/99 to 10/90, although it depends on the particle size of each.

  The carrier is not particularly limited, and examples thereof include iron powder, ferrite powder, magnetite powder, nickel powder, and glass beads. At this time, it is preferable to use a carrier whose surface is coated with a resin or the like. Examples of such a resin include a silicon resin, a fluorine resin, and an acrylic resin. The carrier preferably has a volume average particle size of 25 to 200 μm.

  The image forming apparatus of the present invention has an image forming means for forming an image using toner on a recording medium, and a means for fixing the image formed on the recording medium using the image fixing method of the present invention. The image fixing unit has a mechanism for controlling the pressure for sandwiching the recording medium according to the type of the recording medium. As a means for forming an image using toner on a recording medium, a means for forming a latent image on a latent image carrier, a means for developing the formed latent image with toner, and an image developed with toner are recorded. Known means having means for transferring onto the medium can be used. The means for forming a latent image on the latent image carrier preferably has a means for charging the latent image carrier and a means for exposing the charged latent image carrier.

  FIG. 1 shows a digital copying machine as an example of the image forming apparatus of the present invention. The digital copying machine shown in FIG. 1 has a copying machine main body 1, an automatic document feeder (ADF) 100, and a paper feed unit 300, and a document stacked on the automatic document feeder 100 or the document feeder 101. Are conveyed one by one onto the contact glass 10 on the copying machine main body 1 side, and after the image data is read, the sheet is discharged onto the discharge tray 105. The document set on the document feeder 101 is aligned in the width direction of the sheet by a side fence (not shown), separated from the lowest document by the sheet feed roller 102, and contacted by the transport belt 103. It is conveyed on the glass 10. The feeding unit 107 is also provided with a document width detection sensor 118 and a document length detection sensor 119, which detect the size (B5, A4, B4, etc.) of the document conveyed from the automatic document feeder 100. be able to. Then, after the reading of the image data is completed, the original on the contact glass 10 is discharged onto the paper discharge tray 105 by the conveyance belt 103 and the paper discharge roller 104, and a series of operations is completed.

  Further, at the time of double-sided copying, the original is fed by the paper feed roller 102, passes over the contact glass 10 by the conveying belt 103, is reversed by the reversing claw 106, and is then conveyed again onto the contact glass 10, so The back side is read. Next, the document is transported by the transport belt 103, reversed by the reversing claw 106, and then transported onto the contact glass 10 again to read the surface of the document. Then, the original on the contact glass 10 is discharged onto the paper discharge tray 105 by the conveyance belt 103 and the paper discharge roller 104.

  FIG. 2 shows the configuration of the automatic document feeder. The automatic document feeder 100 is configured to open and close around hinges 81 and 82 provided on the left and right, and a claw 83 is provided on the upper surface of the copier body 1 near the hinge 81. When the automatic document feeder 100 is closed, the claw 83 is inserted into a hole 84 formed on the lower surface of the automatic document feeder 100 at the opposite position. Inside the automatic document feeder 100 adjacent to the hole 84, a lift-up detection sensor 85 and a document detection timing sensor 86 that detect the presence or absence of the claw 83 inserted through the hole 84 are provided. The lift-up detection sensor 85 detects the claw 83 when the automatic document feeder 100 is completely closed (lifted down) and is turned on when the automatic document feeder 100 is open (lifted up). Become. Here, the state in which the automatic document feeder 100 is completely closed is a state in which a part of the lower surface side of the automatic document feeder 100 is in contact with the upper surface of the copying machine main body 1.

  On the other hand, the document detection timing sensor 86 is provided to control the timing of detecting the document size on the contact glass 10 based on the detection results of the document size detection sensors 91 to 93 (see FIG. 3). When the opening angle of the document feeder 100 is within a predetermined angle, the claw 83 is detected and turned on. This angle is a slight angle. When the operator manually opens the automatic document feeder 100, both the lift-up detection sensor 85 and the document detection timing sensor 86 are turned off. As shown in FIG. 3, end face scales 87 and 88 for positioning the original are also provided.

  FIG. 3 shows an arrangement state of the document size detection sensor with respect to the contact glass. Document size detection sensors 91 to 93 are arranged below the contact glass 10. As shown in FIG. 4, the document size detection sensors 91 to 93 receive the reflected light when the light emitted from the light emitting diode 91a is dispersed into three beams and irradiated by the three light receiving elements 91b inside the optical system. This is a reflection type sensor that sees through the contact glass 10 from the inside of the optical system and receives only the reflected light from the document surface to detect the presence or absence of the document. The document size detection sensors 91 to 93 are always operating, and each light receiving element 91b is turned on when a document on the contact glass 10 is detected, and is turned off when a document is not detected. . Since the document size detection sensors 91 to 93 are arranged so as to correspond to various types of document sizes placed at predetermined positions on the contact glass 10, it is possible to determine the presence or absence of a document set, It is possible to accurately detect the document size.

  As shown in FIG. 1, the copying machine main body 1 includes a scanner for reading a document, an image processing circuit, a plotter, and the like. The scanner has a contact glass 10 on which an original is placed and an optical scanning system. The optical scanning system includes an exposure lamp 11, a first mirror 12, a second mirror 13, a third mirror 14, a lens 15, and a full color. A CCD 16 is provided. The exposure lamp 11 and the first mirror 12 are mounted on a first carriage, and the first carriage moves in the sub-scanning direction at a constant speed by a stepping motor when reading a document. The second mirror 13 and the third mirror 14 are mounted on the second carriage, and the second carriage moves at a speed approximately half that of the first carriage by the stepping motor when reading the document. When the first carriage and the second carriage move, the image surface of the document is optically scanned, and the read data is imaged on the light receiving surface of the full-color CCD 16 by the lens 15 and subjected to photoelectric conversion.

  Next, the image data photoelectrically converted into each color of red (R), green (G), and blue (B) by the full color CCD 16 is A / D converted by the image processing circuit, and then the image processing circuit 604 (FIG. 7). Various image processing is performed according to (see). Further, when copying, the writing unit 607 copies the paper. The writing unit 607 includes a laser output unit 20, an fθ lens 21, and a mirror 22. The laser output unit 20 includes a laser diode (LD) that is a laser light source, a polygon mirror, and a polygon motor. The laser output unit 20 emits a black signal laser beam modulated in accordance with the image read by the scanner during copying, and a latent image is formed on the photoreceptor 30. A black developing device 32, an LED writing unit 31 for writing a red signal image, a red developing device 33, a transfer device and a separator (not shown) are arranged around the photoconductor 30 and formed on the photoconductor 30. The transferred toner image is transferred onto a sheet by a transfer device. The paper is selected from any of the duplex unit 40, the first tray 50, the second tray 310, the third tray 320, and the fourth tray 330 in the sheet feeding unit 300 in the copying machine main body 1, and the feed roller 42 and the separation unit. Paper is fed by the roller 49, the first paper feeding device 51, the second paper feeding device 311, the third paper feeding device 321, or the fourth paper feeding device 331. As shown in FIG. 5, the paper size and setting direction of the paper set from the first tray 50 to the fourth tray 330 are adjusted by adjusting the position of the size lever 400 and turning on / off the plurality of push switches 401. It can be detected by a combination of off.

  The paper fed from the duplex unit 40 and the first tray 50 is transported upward by the vertical transport unit 60, and the second paper feeder 311, the third paper feeder 321, or the fourth paper feeder 331. Is fed via the bank vertical conveyance unit 340 and the vertical conveyance unit 60. Then, when a predetermined time elapses after the leading edge of the sheet is detected by the registration sensor 52, the sheet is abutted against the registration roller 53 and stops. Further, the sheet is conveyed by the rotation of the registration roller 53 in synchronization with the sub-scanning effective period signal (FGATE), and the toner image on the photoconductor 30 is transferred. Next, the sheet is separated from the photoreceptor 30 by a separator (not shown), and then conveyed to the fixing device 55 by the conveying device 54, and the toner image is fixed by the fixing device 55. The sheet after fixing is discharged onto the discharge tray 200 by the switching claw 57 and the discharge roller 56 after single-sided printing and double-sided printing at the time of double-sided printing.

  On the other hand, the paper after surface printing at the time of duplex printing is guided to the duplex conveyance path 41 by the switching claw 57, reversed by the feed roller 42 and the separation roller 49, and accumulated (stocked) on the duplex unit 40. The sheet in the duplex unit 40 is raised to abut against the feed roller 42 and is fed to the vertical conveyance unit 60 by the rotation of the feed roller 42 to form an image on the back surface. As shown in FIG. 6, the operation unit controller 500 controls the screen display of the liquid crystal display of the operation unit, controls the lighting display of various LEDs, and controls various key inputs. The system controller 501 (SCU) Paper feed, transport, fixing, duplex printing, process control, etc., image processing controller 502, ADF controller 503, paper feed tray controller 504, FAX controller 505, printer controller 506 (PCU), various loads and various sensor inputs and outputs The signal path is connected. The image processing controller 502 performs image control and scanner reading control, and the ADF controller 503 performs overall control of the automatic document feeder 100. A paper feed tray controller 504 controls the paper feed tray, and a FAX controller 505 performs management of printer data reception and file management.

  The operation of the image forming apparatus of the present invention will be described below with reference to FIGS. First, the exposure lamp 11 is irradiated on the original 600 on the contact glass 10, and the reflected light is read by the full color CCD 16 as image data. Next, the analog image signal separated into red (R), green (G), and blue (B) colors by the full color CCD 16 is amplified by the signal processing circuit 601 to perform light quantity correction. Further, the analog image signal is converted into a digital image signal by the A / D converter 602, subjected to shading correction by the shading correction circuit 603, and sent to the image processing circuit 604. The image processing circuit 604 performs image quality processing such as MTF correction, γ correction, black image generation, color image generation, binary processing, and multi-value processing on the image data, and outputs black data and color data to the selector 605. Is done. In the selector 605, switching to send the image signal to the scaling unit 606 or the image memory controller 608 is performed. The scaling unit 606 enlarges / reduces the image signal in accordance with the scaling factor and sends it to the writing unit 607. On the other hand, the selector 605 and the image memory controller 608 are configured to be able to input and output image signals bi-directionally, and perform settings for the image memory controller 608 and control of the reading unit and the writing unit. A CPU 609, a ROM 610 for storing the program and data, and a working RAM 611 are provided. The CPU 609 writes and reads data in the image memory 612 via the image memory controller 608.

  In the image memory controller 608, the input image data of the original is compressed by an internal image compression device or the like and then sent to the image memory 612. By compressing the image data, the image memory 612 having a limited memory capacity can be used effectively. Further, since a large amount of original image data can be stored at one time, the stored original image data image can be output in page order. In this case, when the image is output, the data in the image memory 612 is output while being sequentially expanded by the expansion device in the image memory controller 608. On the other hand, during FAX transmission, black data is transferred to the FAX image memory 613 by the selector 605. At the time of FAX reception, the received data from the line is demodulated and expanded, and then developed by the FAX image memory 613 and output to the writing unit 607 by the selector 605 via the scaling unit 606. Further, as described above, when the printer data is received, the image data is developed by the printer image memory 614 and then sent to the writing unit 607 by the selector 605.

  As shown in FIG. 8, the fixing device 55 includes a heating roller 700 and a pressure roller 701 that is in pressure contact with the heating roller 700, and the heat roller 700 has a heat-resistant release layer such as PFA or PTFE formed on the surface thereof. A fixing heater 702 (heat source) for heating is provided inside. As the fixing heater 702, a halogen heater, an infrared heater (nichrome wire), or the like is used. Further, temperature sensors 703 and 704 are provided on the surface portions of the heating roller 700 and the pressure roller 701, respectively. At this time, the fixing heater 702 is controlled based on the temperature detection signals from the temperature sensors 703 and 704 so that the temperatures of the heating roller 700 and the pressure roller 701 become constant values. Further, in order to control the amount of heat supplied to the paper P, a pressure mechanism that changes the nip width between the heating roller 700 and the pressure roller 701 is controlled. That is, the heating roller 701 is rotationally driven by a driving mechanism (not shown), and performs fixing processing by applying heat and pressure to the paper P while conveying the paper P in conjunction with the pressure roller 701. The pressure roller 701 has a heat-resistant rubber layer such as silicon formed on the surface. The temperature inside the fixing device 55 (atmosphere temperature) can be detected by the temperature detection means 722.

  The pressure roller 701 is rotatably urged in a direction away from the heating roller 700 by urging means (not shown) while both ends of the shaft are rotatably supported. On the other hand, the pressure roller 701 is cantilevered from below the shaft by a pressure mechanism and is pressed against the lower side of the heating roller 700. The pressurizing mechanism has a stepping motor 710. When the stepping motor 710 rotates forward in the A direction, the driving force is transmitted from the gear 711 provided coaxially to the gear 713 via the idler gear 712. Here, a shaft 714 whose tip is a feed screw is connected to the gear 713, and the anchor 715 can be pulled in the C direction. An end of a spring 716 is attached to the anchor 715, and the other end is attached to the link 717. Accordingly, the link 717 rotates around the fulcrum 718 as the anchor 715 moves horizontally. Then, a substantially triangular lever 719 is fitted to one end of the link 717, and the lever 719 rotates about the fulcrum 720, so that the pressure roller 701 is pushed upward. Thereby, a pressing force is applied to the heating roller 700.

  On the other hand, when the stepping motor 710 rotates reversely in the B direction, the anchor 715 is pushed back in the D direction. Therefore, the lever 719 rotates downward about the fulcrum 720 to lower the pressure roller 701 and Pressure is released. A home position detector 721 is provided below the anchor 715. Since the home position detection unit 721 is turned on / off by a detection piece formed under the anchor 715, the instructed pressure can be applied to the pressure roller 701 by adjusting the movement amount of the anchor 715. it can. Such a pressure mechanism is provided on both sides of the pressure roller 701. In the fixing device 55 configured as described above, when the power source (main switch) is turned on, the fixing heater 702 generates heat and starts heating in the heating roller 700. The temperature sensors 703 and 704 respectively cause the heating roller 700 and the heating roller to be heated. Detection of the surface temperature of the pressure roller 701 is started. When the surface temperatures of the heating roller 700 and the pressure roller 701 reach a temperature at which an unfixed image on the paper P can be fixed (fixing temperature), the warm-up is completed and copying is possible.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 9. Here, a feature of the embodiment of the present invention is that a fixing temperature control is performed in which the fixing temperature is changed by switching the pressing force in accordance with the paper size, the paper type, and the number of continuous sheets. Therefore, before changing the fixing temperature, the paper size of the paper set in the first tray 50 to the fourth tray 330 is detected by the size lever 400 and the push switch 401 (see FIG. 5), and the paper size of the paper is set. The paper type (plain paper, tracing paper, film) is input in advance from the operation unit. For example, pre-scanning is performed before warm-up, image output information is input, and fixing temperature control is started under predetermined fixing conditions based on the input image output information. Similarly, in a printer, FAX, etc., an image output signal is received before warm-up, and the received image output information is input as input information to the CPU of the image output apparatus. Based on the output information thus input, fixing temperature control is started under predetermined fixing conditions.

  FIG. 9 shows an embodiment of a processing procedure for fixing temperature control according to the present invention. Here, this flowchart is the fixing temperature control when the power of the image forming apparatus is OFF, and the fixing temperature control when returning from the low power mode or the sleep mode is to turn on the fixing heater 702 (S2). The fixing temperature control starts from the beginning. First, when the power is turned on (S1), the fixing heater 702 (see FIG. 8) is turned on (S2), the temperature of the heating roller 700 rises, and the fixing device 55 is started up (warm-up). . Next, it is determined whether or not an image output condition (paper size, number of sheets to be passed, paper type) is input from the operation unit (S3). If an image output condition is input (Y), the image output condition is checked (S4). Further, the fixing temperature and the fixing nip width are determined based on the fixing temperature table [° C.] (see Table 1) and the fixing nip width table [mm] (see Table 2) (S5). Is changed (S6). If no image output condition is input (N), the fixing temperature and the fixing nip width are set to standard default values (170 ° C. and 5.5 mm) set in advance (S12), and the pressure is applied. The pressure applied by the roller 701 is changed (S13).

なお、表１では、用紙サイズをＩ（Ａ３Ｙ、Ａ２サイズ以上）及びＩＩ（Ｂ４Ｙ、Ａ３Ｔサイズ以下）に区分し、用紙の紙種を普通紙、フィルム及びトレーシングペーパーとし、連続通紙枚数を１枚目から１０枚目、１１枚目から３０枚目及び３１枚目以上の３段階に設定している。例えば、普通紙Ｉを３１枚以上連続通紙する場合には、１枚目から１０枚目の定着温度が１４０℃、１１枚目から３０枚目の定着温度が１５０℃、３１枚目以上の定着温度が１６０℃となる。

In Table 1, the paper size is divided into I (A3Y, A2 size or larger) and II (B4Y, A3T size or smaller), the paper type is plain paper, film, and tracing paper, and the number of continuous paper passes is The first to tenth sheets, the eleventh to thirtyth sheets, and the thirty-first or more sheets are set in three stages. For example, when 31 or more sheets of plain paper I are continuously passed, the fixing temperature of the first sheet to the tenth sheet is 140 ° C., the fixing temperature of the eleventh sheet to the thirty sheet is 150 ° C., and the 31st sheet or more. The fixing temperature is 160 ° C.

なお、表２では、表１と同様に用紙サイズをＩ及びＩＩに区分し、用紙の紙種を普通紙、フィルム及びトレーシングペーパーとし、連続通紙枚数を１枚目から１０枚目、１１枚目から３０枚目及び３１枚目以上の３段階に設定している。例えば、普通紙Ｉを３１枚以上連続通紙する場合には、１枚目から１０枚目の定着ニップ幅が５．５ｍｍ、１１枚目から３０枚目の定着ニップ幅が５．０ｍｍ、３１枚目以上の定着ニップ幅が４．５ｍｍとなる。

In Table 2, similarly to Table 1, the paper size is divided into I and II, the paper type is plain paper, film, and tracing paper, and the number of continuous paper passes is from the first to the tenth, 11 It is set in 3 stages from the 30th to the 31st and the 31st and above. For example, when 31 or more sheets of plain paper I are continuously passed, the fixing nip width of the 1st sheet to the 10th sheet is 5.5 mm, the fixing nip width of the 11th sheet to the 30th sheet is 5.0 mm, 31 The fixing nip width beyond the first sheet is 4.5 mm.

  When the image output condition is input (Y), the temperature of the heating roller 700 is detected by the temperature sensor 703 (see FIG. 8) (S7), and it is determined whether or not the fixing temperature has been reached. (S8). If the fixing temperature has been reached (Y), warm-up is completed (S9), and image output (copying operation) is started (S10). Next, after the image output is completed, the temperature control is executed based on the preset fixing temperature control during standby (S11). Further, after a predetermined time has elapsed, the mode shifts to a low power mode or a sleep mode that is an OFF mode of the fixing heater. If the fixing temperature has not been reached (N), the process returns to S7.

  On the other hand, if no image output condition is input (N), the temperature of the heating roller 700 is similarly detected by the temperature sensor 703 (S14), and it is determined whether or not the fixing temperature has been reached (S15). ). If the fixing temperature has been reached (Y), the warm-up is completed (S16), and the temperature control is executed based on the preset fixing temperature control during standby (S17). If the fixing temperature has not been reached (N), the process returns to S14.

  Here, FIG. 10 shows the relationship between the number of continuous sheets to be passed and the power consumption. Specifically, the power consumption is the sum of the amount of power consumed during warm-up, the amount of power supplied to the paper, and the amount of power used to maintain the heating roller at the set temperature. , Show how it changes. Further, Conventional Example I is a case where the fixing temperature does not change according to the number of continuously passing sheets, and Conventional Example II is a case where the fixing temperature changes in three stages according to the number of continuously passing sheets. In the conventional example I, the fixing temperature is set high to such an extent that no problem occurs even if continuous paper is passed (for example, 99 sheets). In the conventional example II, as an improvement, the number of continuous papers is increased. Accordingly, energy saving is achieved by lowering the fixing temperature accordingly. As is clear from FIG. 10, comparing Conventional Example I and Conventional Example II, it can be seen that Conventional Example II can reduce the power consumption up to 30 sheets continuously as the fixing temperature is set low. Furthermore, in the embodiment of the present invention, it is possible to set the fixing temperature further lower by changing the fixing nip width, and to supply the minimum amount of heat to the paper, increasing the number of continuous sheets to be passed. Even in this case, power consumption can be reduced.

FIG. 11 shows the relationship between the fixing temperature and the amount of heat supplied to the paper. As shown in FIG. 11, when the fixing nip width is fixed, when the fixing temperature changes from T _{2 to} T ₄ , the amount of heat supplied to the paper changes from Q _{1 to} Q ₂ . Here, since Q ₁ is the minimum heat amount necessary to ensure the fixability, for example, when the fixing temperature is set to T ₄ , an excessive amount of heat Q ₂ is supplied to the sheet. Therefore, in the embodiment of the present invention, the fixing nip width is selected so that the amount of heat supplied to the paper always becomes Q1 by changing the fixing nip width. As a result, the fixing temperature is satisfactorily fixed in the range of T _{1 to} T ₃ , and as a result, the fixing temperature can be lowered, and energy saving can be achieved by reducing the power consumption. Note that the amount of heat Q supplied to the paper is expressed by the equation

により計算することができる。なお、ｋは、加熱ローラとトナーの熱取得度による係数である。

Can be calculated. Note that k is a coefficient depending on the heat acquisition degree of the heating roller and the toner.

  FIG. 12 shows an embodiment of the processing procedure for fixing temperature control during standby. Here, conventionally, the temperature of the heating roller in the low power mode is a constant temperature, and the temperature of the heating roller is set so that the fixing property after returning from the low power mode is satisfied. Although it was possible to change the temperature of the heating roller from the operation unit, the machine does not automatically change the set value. In addition, the fixing device before shifting to the low power mode is a state where the fixing device stands up from the room temperature and the image output is not performed, that is, when the temperature of the pressure roller is low and the mode is shifted to the low power mode. In some cases, a large amount of image is output, and the pressure roller is shifted to the low power mode with the temperature of the pressure roller being considerably high. Therefore, the temperature of the heating roller in the low power mode has been determined so that the fixability after returning from the low power mode can be satisfied even when the pressure roller is shifted from the low temperature state to the low power mode. However, when the pressure roller temperature is changed to a low power mode from a high temperature state, there is a margin in the set value of the pressure roller temperature, and energy saving is insufficient. Therefore, in the present embodiment, the temperature of the pressure roller is detected, the temperature of the heating roller in the low power mode is changed according to the temperature, and when the temperature of the pressure roller is high, the temperature in the low power mode is changed. Reduce the temperature of the heating roller. Details will be described below.

First, a time S during which no image output condition is input is counted by a timer (S1), and it is determined whether or not S is 15 minutes or more (S2). Here, when S is 15 minutes or more, it shifts to the low power mode (S3). Moreover, when S is not 15 minutes or more, it returns to S1. Note that the set value can be changed from the operation unit during this time. When shifting to the low power mode, the temperature of the heating roller 700 is reset to a low temperature, the display on the operation unit is turned off, and the fan provided in the machine is stopped. At this time, detects the temperature T of the pressure roller 701 (S4), it performs a fixing temperature theta ₂ of the decision in the low power mode as shown in Table 3 (S5).

次に、定着ヒータ７０２をＯＮ／ＯＦＦ制御し、加熱ローラ７００の温度をθ_２に制御する（Ｓ６）。さらに、操作部から画像出力条件（用紙サイズ、通紙枚数、紙種）が入力されているか否かの判別が行われる（Ｓ７）。ここで、画像入力条件が入力されている場合（Ｙ）には、低電力モードが解除される。また、画像出力条件が入力されていない場合（Ｎ）には、Ｓ４に戻る。

Next, the fixing heater 702 is turned on / off, and the temperature of the heating roller 700 is controlled to θ ₂ (S6). Further, it is determined whether image output conditions (paper size, number of sheets to be passed, paper type) are input from the operation unit (S7). Here, when the image input condition is input (Y), the low power mode is canceled. If no image output condition is input (N), the process returns to S4.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to the examples. In addition, a part means a weight part.

[Synthesis of linear polyester resin L1]
Propylene oxide 2.0 mol adduct of bisphenol A 1040 g (3.0 mol), terephthalic acid 291 g (1.5 mol), dodecenyl succinic acid 93 g (1.5 mol) and tin octylate 10 g in a nitrogen atmosphere at 5 ° C. The mixture was heated to 230 ° C. at a rate of temperature rise / minute, and then reacted for 5 hours under a reduced pressure of 10 to 20 mmHg. Next, after cooling to room temperature, it was pulverized to synthesize a linear polyester resin L1. The linear polyester resin L1 had a weight average molecular weight of 5500.

[Synthesis of linear polyester resin L2]
700 g (2.0 mol) of ethylene oxide 2.2 mol adduct of bisphenol A, 520 g (1.0 mol) of propylene oxide 2.0 mol adduct of bisphenol A, 35 g (0.3 mol) fumaric acid, and 522 g of terephthalic acid (2.7 mol) and 5 g of tin (II) dioctanoate were reacted for 2 hours while stirring at 190 ° C. in a nitrogen atmosphere. Next, 8 g of tin (II) dioctanoate was additionally added, and the mixture was heated to 230 ° C. at a rate of 5 ° C./min, and then reacted for 8 hours under a reduced pressure of 1 to 10 mmHg. Furthermore, after cooling to room temperature, it grind | pulverized and synthesize | combined linear polyester resin L2. The linear polyester resin L2 had a weight average molecular weight of 850000.

[Synthesis of Non-Linear Polyester Resin H1]
945 g (2.7 mol) of ethylene oxide 2.2 mol adduct of bisphenol A, 175 g (0.3 mol) of propylene oxide 2.0 mol adduct of bisphenol A, 480 g (2.5 mol) trimellitic anhydride, The acid 60g (0.5mol) and the tin (II) octylate 3g were made to react for 3 hours, stirring at 190 degreeC by nitrogen atmosphere. Next, 4 g of tin (II) octylate was additionally charged and heated to 230 ° C. at a rate of temperature increase of 5 ° C./min, and then reacted for 7 hours under a reduced pressure of 1 to 10 mmHg. Furthermore, after cooling to room temperature, it grind | pulverized and synthesize | combined nonlinear polyester resin H1. In the non-linear polyester resin H1, the content of the crosslinking component was 30% by weight.

[Synthesis of Crystalline Polyester Resin C1]
1L of 1,4-butanediol, 120 g of ethylene glycol, 1100 g of malonic acid, 350 g of phthalic acid, 10.5 g of tin octylate and 1.5 g of hydroquinone, 5 L equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple And was allowed to react at 160 ° C. for 5 hours. Next, the temperature was raised to 200 ° C. and reacted for 1 hour, and then reacted for 2 hours under a reduced pressure of 1 to 10 mmHg to synthesize a crystalline polyester resin C1.

[Synthesis of Styrene Acrylic Resin SA1]
500 parts of cumene was placed in the reaction vessel, the inside of the reaction vessel was replaced with nitrogen gas, and the mixture was heated to 150 ° C. Next, a solution obtained by mixing 175 parts of styrene, 50 parts of t-butyl acrylate, 25 parts of n-butyl acrylate, and 5 parts of benzoyl peroxide was dropped into the reaction vessel over 3 hours, and the solution was added at 150 ° C. Polymerized for hours. Further, cumene was removed, cooled to room temperature, and then pulverized to synthesize styrene acrylic resin SA1.

[Synthesis of Hybrid Resin HB1]
Stainless steel stirring rod, 25 mol of phthalic acid, 5 mol of trimellitic anhydride, 5 mol of bisphenol A (2,2) propylene oxide, 25 mol of bisphenol A (2,2) ethylene oxide and 0.05 mol of tin (II) octylate The flask was equipped with a condenser, nitrogen gas inlet tube and thermometer. Next, with stirring at 135 ° C. in a nitrogen atmosphere, a mixture of 30 mol of styrene, 10 mol of butyl methacrylate, and 0.9 mol of t-butyl hydroperoxide was added dropwise from a dropping funnel over 5 hours. After completion of the dropwise addition, the mixture was aged at 130 ° C. for 6 hours, then heated to 220 ° C. and reacted for 5 hours to synthesize a hybrid resin HB1. Hybrid resin HB1 had a styrene acrylic resin content of 23% by weight.

[Example 1]
20 parts of linear polyester resin L1, 38 parts of non-linear polyester resin H1, 12 parts of crystalline polyester resin C1, 30 parts of hybrid resin HB1, and zinc (III) salicylate complex E-84 (Orient Chemical Co., Ltd.) 2 parts, linear ester wax WEP-3 (Nippon Yushi Co., Ltd.) 8 parts, carbon black C44 (Mitsubishi Chemical Co., Ltd.) 10 parts, Henschel mixer FM10B (Mitsui Miike Chemical Co., Ltd.) And premixed. Next, melt kneading was performed at 120 ° C. using a biaxial kneader PCM-30 (manufactured by Ikegai Co., Ltd.) at a kneading feed rate of 10 kg / hour. Furthermore, after finely pulverizing using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), it was classified using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. .

  Next, 100 parts of the base particles and 4.0 parts of colloidal silica H-2000 (manufactured by Wacker) were mixed using a sample mill and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 4. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

[Example 2]
A developer was obtained in the same manner as in Example 1 except that 2.8 parts of colloidal silica H-1303VP (manufactured by Wacker) was used instead of 4.0 parts of colloidal silica H-2000 (manufactured by Wacker). .

[Example 3]
A developer was obtained in the same manner as in Example 1 except that 5.0 parts of colloidal silica R-972 (manufactured by Client Japan) was used instead of 4.0 parts of colloidal silica H-2000 (manufactured by Wacker). It was.

[Example 4]
A developer was obtained in the same manner as in Example 1 except that 1.0 part of colloidal silica H-2000 (manufactured by Wacker) was used instead of 4.0 part of colloidal silica H-2000 (manufactured by Wacker). .

[Example 5]
87.5 parts of linear polyester resin L2, 10 parts of crystalline polyester resin C1, 2.5 parts of styrene acrylic resin SA1, and iron (II) salicylate complex X-11 (manufactured by Orient Chemical Industries) 5 parts, 5 parts of linear ester wax WEP-1 (manufactured by NOF Corporation), 10 parts of carbon black C44 (manufactured by Mitsubishi Chemical Corporation) and 1 part of magnetite fine particles EPT-1000 (manufactured by Toda Kogyo Co., Ltd.) Premixing was performed using an N-shell mixer FM10B (Mitsui Miike Chemical Co., Ltd.). Next, melt kneading was performed at 160 ° C. using a biaxial kneader PCM-30 (manufactured by Ikegai Co., Ltd.) at a kneading feed rate of 15 kg / hour. Furthermore, after finely pulverizing using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), it was classified using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. .

  Next, 100 parts of the base particles and 2.0 parts of colloidal silica H-30 (manufactured by Clariant) were mixed using a sample mill, and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 4. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

[Example 6]
70 parts of a non-linear polyester resin H1, 30 parts of a crystalline polyester resin C1, 3 parts of a chromium-containing azo complex PB-34 (manufactured by Orient Chemical Industries), and a linear ester wax WEP-1 (Nippon Yushi) 5 parts) and 10 parts of carbon black C44 (Mitsubishi Chemical Corporation) were premixed using a Henschel mixer FM10B (Mitsui Miike Chemical Co., Ltd.). Next, melt kneading was performed at 90 ° C. using a biaxial kneader PCM-30 (manufactured by Ikegai Co., Ltd.) at a kneading feed rate of 10 kg / hour. Furthermore, after finely pulverizing using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), it was classified using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. .

  Next, 100 parts of base particles and 1.2 parts of colloidal silica H-30 (manufactured by Clariant) were mixed using a sample mill, and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 4. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

[Example 7]
50 parts of non-linear polyester resin H1, 40 parts of linear polyester resin L1, 10 parts of hybrid resin HB1, 5 parts of chromium-containing azo complex PB-34 (manufactured by Orient Chemical Co., Ltd.), and linear ester 5 parts of wax WEP-1 (manufactured by NOF Corporation) and 10 parts of carbon black C44 (manufactured by Mitsubishi Chemical Corporation) were premixed using a Henschel mixer FM10B (manufactured by Mitsui Miike Chemical Co., Ltd.). Next, melt kneading was performed at 130 ° C. using a biaxial kneader PCM-30 (manufactured by Ikegai Co., Ltd.) at a kneading feed rate of 10 kg / hour. Furthermore, after finely pulverizing using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), it was classified using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. .

  Next, 100 parts of base particles and 0.5 part of colloidal silica H-2000 (manufactured by Clariant) were mixed using a sample mill, and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 4. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

［線状ポリエステル樹脂Ｉの合成］
ビスフェノールＡのエチレンオキシド２．０モル付加物６５１ｇ（２．０ｍｏｌ）と、シクロヘキサンジメタノール１４４ｇ（２．０ｍｏｌ）と、シクロヘキサンジカルボン酸８００ｇ（４．０ｍｏｌ）と、ジブチルスズ１０ｇを窒素雰囲気下、５℃／分の昇温速度で２３０℃まで加温した後、１０〜２０ｍｍＨｇの減圧下で５時間反応させた。次に、室温まで冷却した後、粉砕し、線状ポリエステル樹脂Ｉを合成した。線状ポリエステル樹脂Ｉは、重量平均分子量が４２００であった。

[Synthesis of linear polyester resin I]
651 g (2.0 mol) of an ethylene oxide 2.0 mol adduct of bisphenol A, 144 g (2.0 mol) of cyclohexanedimethanol, 800 g (4.0 mol) of cyclohexanedicarboxylic acid, and 10 g of dibutyltin in a nitrogen atmosphere at 5 ° C. / The mixture was heated to 230 ° C. at a temperature rising rate of 5 minutes, and then reacted for 5 hours under a reduced pressure of 10 to 20 mmHg. Next, after cooling to room temperature, it was pulverized to synthesize a linear polyester resin I. The linear polyester resin I had a weight average molecular weight of 4200.

[Synthesis of Crystalline Polyester Resin II]
120 g (2.0 mol) of ethylene glycol, 118 g (1.0 mol) of succinic acid, 146 g (1.0 mol) of adipic acid, 15 g of titanium tetrabutoxide and 1.5 g of hydroquinone, a nitrogen introduction tube, a dehydration tube, a stirrer And placed in a 5 L four-necked flask equipped with a thermocouple and reacted at 160 ° C. for 5 hours. Next, the temperature was raised to 200 ° C. and reacted for 1 hour, and then reacted for 2 hours under a reduced pressure of 1 to 10 mmHg to synthesize a crystalline polyester resin II.

[Synthesis of Non-Linear Polyester Resin III]
Ethylene oxide 2.2 mol adduct of bisphenol A 975 g (3 mol), trimellitic anhydride 192 g (1 mol), maleic anhydride 196 g (2 mol), and titanium terephthalate 20 g were heated at 5 ° C./min in a nitrogen atmosphere. After heating to 230 ° C. at a temperature rate, the reaction was carried out for 7 hours under a reduced pressure of 1 to 10 mmHg. Next, after cooling to room temperature, it was pulverized to synthesize a non-linear polyester resin III. In the non-linear polyester resin III, the content of the crosslinking component was 25% by weight.

[Comparative Example 1]
50 parts of linear polyester resin I, 50 parts of non-linear polyester resin III, 5 parts of chromium-containing azo complex PB-34 (manufactured by Orient Chemical Industries), and linear ester wax WEP-1 (Nippon Yushi) 5 parts and 10 parts of carbon black C44 (Mitsubishi Chemical Corporation) were premixed using a Henschel mixer FM10B (Mitsui Miike Chemical Co., Ltd.), and then a twin-screw kneader PCM-30 (Ikegai) Was used and melt kneaded at 130 ° C. with a kneading feed rate of 10 kg / hour. Next, after finely pulverizing using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), classification is performed using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. It was.

  Next, 100 parts of base particles and 2.5 parts of colloidal silica H-2000 (manufactured by Clariant) were mixed using a sample mill, and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 5. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

[Comparative Example 2]
20 parts linear polyester resin I, 50 parts non-linear polyester resin III, 20 parts crystalline polyester resin II, 10 parts styrene acrylic resin SA1, and iron (II) salicylate complex X-11 3 parts (made by Orient Chemical Industry Co., Ltd.), 5 parts linear ester wax WEP-3 (made by NOF Corporation), 10 parts carbon black C44 (made by Mitsubishi Chemical Corporation), Henschel mixer FM10B (Mitsui Miike Chemical) And premixed using a biaxial kneader PCM-30 (manufactured by Ikegai Co., Ltd.), and kneaded at 90 ° C. with a kneading feed rate of 10 kg / hour. Next, the mixture is finely pulverized using a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.) and then classified using an airflow classifier MDS-I (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain base particles. It was.

  Next, 100 parts of base particles and 2.5 parts of colloidal silica H-2000 (manufactured by Clariant) were mixed using a sample mill, and then sieved with 350 mesh to obtain a toner having the characteristics shown in Table 5. .

  Further, a toner and a silicone-coated carrier having an average particle diameter of 50 μm were mixed so that the toner content was 5% by weight to obtain a developer.

［評価方法及び評価結果］
Ｉｍａｇｉｏ ｎｅｏ４００Ｗ（リコー社製）に、図８に示す定着装置を装備したものに現像剤を投入し、図９に示す定着温度制御の処理手順に従って、以下の評価を行った。評価結果は、表４及び表５に示されているが、比較例１においては、条件１のホットオフセットにおいて、評価の翌日に冷えて固まったトナーの塊が定着紙に落下した。このとき、必要に応じて、図１３に示すオイル塗布ローラ７２３が接離可能に設けられている定着装置を用いた。オイル塗布ローラ７２３は、金属製の芯金の表面に耐熱性フェルトを巻き付けて構成したローラであり、表面のフェルトにオフセット防止用の潤滑剤であるシリコンオイルが含浸されている。オイル塗布ローラ７２３は、回転軸との間に設けられた一方向クラッチによって加熱ローラ７００が回転する際には追随しない状態に維持されるようになっている。このため、加熱ローラ７００と当接した際には回転しない状態に維持されるので、加熱ローラ７００の表面に付着しているトナーや紙粉を回収する掻き取り部材、いわゆる、クリーニング部材として機能する。

[Evaluation method and evaluation results]
A developer was put into an image of Neorio 400W (manufactured by Ricoh) equipped with the fixing device shown in FIG. 8, and the following evaluation was performed according to the fixing temperature control processing procedure shown in FIG. The evaluation results are shown in Tables 4 and 5. In Comparative Example 1, in the hot offset of Condition 1, the lump of toner that had cooled and hardened on the next day of the evaluation dropped on the fixing paper. At this time, a fixing device provided with an oil application roller 723 shown in FIG. The oil application roller 723 is a roller configured by winding a heat resistant felt around the surface of a metal core, and the surface felt is impregnated with silicon oil which is a lubricant for preventing offset. The oil application roller 723 is maintained in a state that does not follow when the heating roller 700 is rotated by a one-way clutch provided between the oil application roller 723 and the rotation shaft. For this reason, since it is maintained in a non-rotating state when it comes into contact with the heating roller 700, it functions as a scraping member that collects toner and paper dust adhering to the surface of the heating roller 700, a so-called cleaning member. .

  The following evaluation was performed after printing 100,000 sheets in a normal temperature and normal humidity environment (25 ° C., 60% RH).

  The fog was evaluated by visual observation, and A was determined when there was no fog, B was determined as being practically problematic, and C was determined as being practical when there was a problem with fog.

  The sharpness was determined according to the evaluation criteria shown in FIG. 14 by enlarging the “Den” character of about 2 mm square by about 30 times. Ranks 2 and 4 are intermediate between ranks 1 and 3 and ranks 3 and 5, respectively.

  The image density was determined by measuring the density of a solid black circle having a diameter of 3 cm at 10 points using a Macbeth densitometer, and obtaining an average value. If this value is 1.20 or more, there is no practical problem.

Regarding the fixing rate and hot offset property, when tracing paper is selected as a sheet by the operation panel and a solid black circle having a diameter of 3 cm and an image density of 1.35 to 1.40 is formed (condition 1), Evaluation was performed in the case of forming an image (condition 2) in the same manner as in condition 1 except that plain paper was selected as the sheet using the operation panel. The fixing rate is determined by applying a fixing tape (manufactured by 3M) to the fixed image, applying a certain pressure (2 kg), then slowly peeling it off, and measuring the image density before and after that with a Macbeth densitometer. It was evaluated by. The fixing rate is expressed by the formula: fixing rate [%] = image density after peeling with tape / original image density × 100
Is calculated from At the same time, it was visually evaluated whether a hot offset occurred in a cycle of the heating roller.

It is a figure which shows an example of the image forming apparatus of this invention. FIG. 3 is a perspective view illustrating a configuration of an automatic document feeder. It is a perspective view which shows the arrangement | positioning state of the document size detection sensor with respect to contact glass. It is a perspective view which shows the structure of a document size detection sensor. It is a perspective view which shows the structure of each tray. 2 is a block diagram showing a control system of a digital copying machine. FIG. 1 is an overall block diagram illustrating a configuration of an image processing circuit in a digital copying machine. FIG. 3 is a perspective view illustrating a configuration of a fixing device. 4 is a flowchart illustrating an embodiment of a processing procedure for fixing temperature control according to the present invention. It is a figure which shows the relationship between the number of continuous paper passing and power consumption. FIG. 6 is a diagram illustrating a relationship between a fixing temperature and the amount of heat supplied to a sheet. 6 is a flowchart illustrating an embodiment of a processing procedure for fixing temperature control during standby. FIG. 2 is a perspective view illustrating a configuration of a fixing device used in an example. It is a figure which shows the evaluation criteria of sharpness.

Explanation of symbols

700 Heating roller 701 Pressure roller P Paper

Claims (8)

The unfixed image is sandwiched between the unfixed image formed on the recording medium by a heating roller capable of being heated and a pressure roller capable of being pressed against the heating roller. An image fixing method for fixing an image, comprising:
According to the type of the recording medium, the pressure for sandwiching the recording medium is controlled,
The unfixed image is formed using toner,
The toner has an amorphous polyester resin containing an inorganic tin (II) compound, has a measurement temperature of 130 ° C., a tan δ of 1.1 to 2.0 at a frequency of 1 Hz to 10 Hz, and a measurement temperature of 130 ° C. An image fixing method, wherein the ratio of tan δ at a measurement temperature of 130 ° C. and a frequency of 10 Hz to tan δ at a frequency of 1 Hz is 1.0 or more and 1.8 or less. The image fixing method according to claim 1, wherein the toner has a storage elastic modulus of 1 × 10 ⁴ Pa to 5 × 10 ⁵ Pa at a measurement temperature of 130 ° C. and a frequency of 1 Hz to 10 Hz.   2. The toner according to claim 1, wherein the toner has a weight average particle diameter of 3.0 μm or more and 8.0 μm or less, and a ratio of the weight average particle diameter to the number average particle diameter of 1.20 or more and 1.40 or less. Or the image fixing method described in 2; The toner contains an inorganic tin (II) compound as a catalyst.

(In the formula, R is a divalent group of a linear unsaturated aliphatic hydrocarbon having 2 to 20 carbon atoms, and n is an integer of 2 to 20)
The image fixing method according to claim 1, further comprising a crystalline polyester resin having a structure represented by: The toner further includes a styrene acrylic resin,
The image fixing method according to claim 4, wherein a weight ratio of the styrene acrylic resin to the crystalline polyester resin is 0.25 or more and 1 or less.   The image fixing method according to claim 5, wherein the toner contains the styrene acrylic resin and a hybrid resin having the polyester resin. Forming an image on the recording medium using toner;
An image forming method comprising the step of fixing the image using the image fixing method according to claim 1. Image forming means for forming an image on a recording medium using toner;
Image fixing means for fixing the image using the image fixing method according to any one of claims 1 to 6;
The image forming apparatus according to claim 1, wherein the image fixing unit includes a mechanism for controlling a pressure for sandwiching the recording medium in accordance with the type of the recording medium.

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